854 research outputs found
Systematics and Palynology of Picrodendron Further Evidence for Relationship with the Oldfieldioideae (Euphorbiaceae)
Although known to botanical science for 285 years, the genus Picrodendron Planchon has been poorly understood for most of this time. The most pervasive problem has been that of discerning familial relationships, and there have been additional difficulties in typifying the generic name (Hayden & Reveal, 1980) and in distinguishing its three nominate species. This paper provides a systematic treatment for Picrodendron and demonstrates its relationships with Euphorbiaceae subfam. Oldfieldioideae Kohler & Webster as evidenced by data on gross morphology, palynology, anatomy, and cytology
MitoQ supplementation augments acute exercise-induced increases in muscle PGC1α mRNA and improves training-induced increases in peak power independent of mitochondrial content and function in untrained middle-aged men
The role of mitochondrial ROS in signalling muscle adaptations to exercise training has not been explored in detail. We investigated the effect of supplementation with the mitochondria-targeted antioxidant MitoQ on a) the skeletal muscle mitochondrial and antioxidant gene transcriptional response to acute high-intensity exercise and b) skeletal muscle mitochondrial content and function following exercise training. In a randomised, double-blind, placebo-controlled, parallel design study, 23 untrained men (age: 44 ± 7 years, VO2peak: 39.6 ± 7.9 ml/kg/min) were randomised to receive either MitoQ (20 mg/d) or a placebo for 10 days before completing a bout of high-intensity interval exercise (cycle ergometer, 10 × 60 s at VO2peak workload with 75 s rest). Blood samples and vastus lateralis muscle biopsies were collected before exercise and immediately and 3 h after exercise. Participants then completed high-intensity interval training (HIIT; 3 sessions per week for 3 weeks) and another blood sample and muscle biopsy were collected. There was no effect of acute exercise or MitoQ on systemic (plasma protein carbonyls and reduced glutathione) or skeletal muscle (mtDNA damage and 4-HNE) oxidative stress biomarkers. Acute exercise-induced increases in skeletal muscle peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α) mRNA expression were augmented in the MitoQ group. Despite this, training-induced increases in skeletal muscle mitochondrial content were similar between groups. HIIT-induced increases in VO2peak and 20 km time trial performance were also similar between groups while training-induced increases in peak power achieved during the VO2peak test were augmented in the MitoQ group. These data suggest that training-induced increases in peak power are enhanced following MitoQ supplementation, which may be related to the augmentation of skeletal muscle PGC1α expression following acute exercise. However, these effects do not appear to be related to an effect of MitoQ supplementation on exercise-induced oxidative stress or training-induced mitochondrial biogenesis in skeletal muscle
Why the Realist-Instrumentalist Debate about Rational Choice Rests on a Mistake
Within the social sciences, much controversy exists about which status should be ascribed to the rationality assumption that forms the core of rational choice theories. Whilst realists argue that the rationality assumption is an empirical claim which describes real processes that cause individual action, instrumentalists maintain that it amounts to nothing more than an analytically set axiom or ‘as if’ hypothesis which helps in the generation of accurate predictions. In this paper, I argue that this realist-instrumentalist debate about rational choice theory can be overcome once it is realised that the rationality assumption is neither an empirical description nor an ‘as if’ hypothesis, but a normative claim
Neural Circuitry of Novelty Salience Processing in Psychosis Risk: Association With Clinical Outcome
Psychosis has been proposed to develop from dysfunction in a hippocampal-striatal-midbrain circuit, leading to aberrant salience processing. Here, we used functional magnetic resonance imaging (fMRI) during novelty salience processing to investigate this model in people at clinical high risk (CHR) for psychosis according to their subsequent clinical outcomes. Seventy-six CHR participants as defined using the Comprehensive Assessment of At-Risk Mental States (CAARMS) and 31 healthy controls (HC) were studied while performing a novelty salience fMRI task that engaged an a priori hippocampal-striatal-midbrain circuit of interest. The CHR sample was then followed clinically for a mean of 59.7 months (~5 y), when clinical outcomes were assessed in terms of transition (CHR-T) or non-transition (CHR-NT) to psychosis (CAARMS criteria): during this period, 13 individuals (17%) developed a psychotic disorder (CHR-T) and 63 did not. Functional activation and effective connectivity within a hippocampal-striatal-midbrain circuit were compared between groups. In CHR individuals compared to HC, hippocampal response to novel stimuli was significantly attenuated (P = .041 family-wise error corrected). Dynamic Causal Modelling revealed that stimulus novelty modulated effective connectivity from the hippocampus to the striatum, and from the midbrain to the hippocampus, significantly more in CHR participants than in HC. Conversely, stimulus novelty modulated connectivity from the midbrain to the striatum significantly less in CHR participants than in HC, and less in CHR participants who subsequently developed psychosis than in CHR individuals who did not become psychotic. Our findings are consistent with preclinical evidence implicating hippocampal-striatal-midbrain circuit dysfunction in altered salience processing and the onset of psychosis
Priority for the Worse Off and the Social Cost of Carbon
The social cost of carbon (SCC) is a monetary measure of the harms from carbon emission. Specifically, it is the reduction in current consumption that produces a loss in social welfare equivalent to that caused by the emission of a ton of CO2. The standard approach is to calculate the SCC using a discounted-utilitarian social welfare function (SWF)—one that simply adds up the well-being numbers (utilities) of individuals, as discounted by a weighting factor that decreases with time. The discounted-utilitarian SWF has been criticized both for ignoring the distribution of well-being, and for including an arbitrary preference for earlier generations. Here, we use a prioritarian SWF, with no time-discount factor, to calculate the SCC in the integrated assessment model RICE. Prioritarianism is a well-developed concept in ethics and theoretical welfare economics, but has been, thus far, little used in climate scholarship. The core idea is to give greater weight to well-being changes affecting worse off individuals. We find substantial differences between the discounted-utilitarian and non-discounted prioritarian SCC
Mood instability, mental illness and suicidal ideas : results from a household survey
Purpose:
There is weak and inconsistent evidence that mood instability (MI) is associated with depression, post traumatic stress disorder (PTSD) and suicidality although the basis of this is unclear. Our objectives were first to test whether there is an association between depression and PTSD, and MI and secondly whether MI exerts an independent effect on suicidal thinking over and above that explained by common mental disorders.
Methods:
We used data from the Adult Psychiatric Morbidity Survey 2007 (N = 7,131). Chi-square tests were used to examine associations between depression and PTSD, and MI, followed by regression modelling to examine associations between MI and depression, and with PTSD. Multiple logistic regression analyses were used to assess the independent effect of MI on suicidal thinking, after adjustment for demographic factors and the effects of common mental disorder diagnoses.
Results:
There are high rates of MI in depression and PTSD and the presence of MI increases the odds of depression by 10.66 [95 % confidence interval (CI) 7.51–15.13] and PTSD by 8.69 (95 % CI 5.90–12.79), respectively, after adjusting for other factors. Mood instability independently explained suicidal thinking, multiplying the odds by nearly five (odds ratio 4.82; 95 % CI 3.39–6.85), and was individually by some way the most important single factor in explaining suicidal thoughts.
Conclusions:
MI is strongly associated with depression and PTSD. In people with common mental disorders MI is clinically significant as it acts as an additional factor exacerbating the risk of suicidal thinking. It is important to enquire about MI as part of clinical assessment and treatment studies are required
Clinical practice: Drug desensitization in children
Immediate type allergic reactions to medication are potentially life threatening and can hamper drug therapy of several medical conditions. Exact incidence and prevalence data for these reactions in children are lacking. If no alternative drug treatment is available, a desensitization procedure may secure the continuation of necessary therapy. Desensitization is only appropriate in case of a strong suspicion of an IgE-mediated allergic reaction. It should be performed by trained clinicians (allergy specialists) in a hospital setting where treatment of a potential anaphylactic reaction can be done without any delay. In this article, literature describing desensitization procedures for several antibiotics, antineoplastic agents, and vaccines in children is reviewed. In general, desensitization schemes for children differ only in final dose from schemes for adults. Contradictory data were found regarding the protective effects of premedication with antihistamines and glucocorticoids
Improving gait classification in horses by using inertial measurement unit (IMU) generated data and machine learning
For centuries humans have been fascinated by the natural beauty of horses in motion and their different gaits. Gait classification (GC) is commonly performed through visual assessment and reliable, automated methods for real-time objective GC in horses are warranted. In this study, we used a full body network of wireless, high sampling-rate sensors combined with machine learning to fully automatically classify gait. Using data from 120 horses of four different domestic breeds, equipped with seven motion sensors, we included 7576 strides from eight different gaits. GC was trained using several machine-learning approaches, both from feature-extracted data and from raw sensor data. Our best GC model achieved 97% accuracy. Our technique facilitated accurate, GC that enables in-depth biomechanical studies and allows for highly accurate phenotyping of gait for genetic research and breeding. Our approach lends itself for potential use in other quadrupedal species without the need for developing gait/animal specific algorithms
Testing foundations of quantum mechanics with photons
The foundational ideas of quantum mechanics continue to give rise to
counterintuitive theories and physical effects that are in conflict with a
classical description of Nature. Experiments with light at the single photon
level have historically been at the forefront of tests of fundamental quantum
theory and new developments in photonics engineering continue to enable new
experiments. Here we review recent photonic experiments to test two
foundational themes in quantum mechanics: wave-particle duality, central to
recent complementarity and delayed-choice experiments; and Bell nonlocality
where recent theoretical and technological advances have allowed all
controversial loopholes to be separately addressed in different photonics
experiments.Comment: 10 pages, 5 figures, published as a Nature Physics Insight review
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Primary and malignant cholangiocytes undergo CD40 mediated Fas dependent Apoptosis, but are insensitive to direct activation with exogenous fas ligand
Introduction
Cholangiocarcinoma is a rare malignancy of the biliary tract, the incidence of which is rising, but the pathogenesis of which remains uncertain. No common genetic defects have been described but it is accepted that chronic inflammation is an important contributing factor. We have shown that primary human cholangiocyte and hepatocyte survival is tightly regulated via co-operative interactions between two tumour necrosis family (TNF) receptor family members; CD40 and Fas (CD95). Functional deficiency of CD154, the ligand for CD40, leads to a failure of clearance of biliary tract infections and a predisposition to cholangiocarcinoma implying a direct link between TNF receptor-mediated apoptosis and the development of cholangiocarcinoma.
Aims
To determine whether malignant cholangiocytes display defects in CD40 mediated apoptosis. By comparing CD40 and Fas-mediated apoptosis and intracellular signalling in primary human cholangiocytes and three cholangiocyte cell lines.
Results
Primary cholangiocytes and cholangiocyte cell lines were relatively insensitive to direct Fas-mediated killing with exogenous FasL when compared with Jurkat cells, which readily underwent Fas-mediated apoptosis, but were extremely sensitive to CD154 stimulation. The sensitivity of cells to CD40 activation was similar in magnitude in both primary and malignant cells and was STAT-3 and AP-1 dependent in both.
Conclusions
1) Both primary and malignant cholangiocytes are relatively resistant to Fas–mediated killing but show exquisite sensitivity to CD154, suggesting that the CD40 pathway is intact and fully functional in both primary and malignant cholangiocytes 2) The relative insensitivity of cholangiocytes to Fas activation demonstrates the importance of CD40 augmentation of Fas dependent death in these cells. Agonistic therapies which target CD40 and associated intracellular signalling pathways may be effective in promoting apoptosis of malignant cholangiocytes
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