julilili42/papers huggingface dataset:
Stability and quasinormal modes of black holes in tensor-vector-scalar theory: Scalar field perturbations
2010-12-30

The imminent detection of gravitational waves will trigger precision tests of gravity through observations of quasinormal ringing of black holes. While General Relativity predicts just two polarizations of gravitational waves, the so-called plus and cross polarizations, numerous alternative theories of gravity predict up to six different polarizations which will potentially be observed in current and future generations of gravitational wave detectors. Bekenstein's Tensor-Vector-Scalar (TeVeS) theory and its generalization fall into one such class of theory that predict the full gamut of six polarizations of gravitational waves. In this paper we begin the study of quasinormal modes (QNMs) in TeVeS by studying perturbations of the scalar field in a spherically symmetric background. We show that, at least in the case where superluminal propagation of perturbations is not present, black holes are generically stable to this kind of perturbation. We also make a unique prediction that, as the limit of the various coupling parameters of the theory tend to zero, the QNM spectrum tends to times the QNM spectrum induced by scalar perturbations of a Schwarzschild black hole in General Relativity due to the intrinsic presence of the background vector field. We further show that the QNM spectrum does not vary significantly from this value for small values of the theory's coupling parameters, however can vary by as much as a few percent for larger, but still physically relevant parameters.
Mindfulness Meditation: A Preliminary Study on Meditation Practice During Everyday Life Activities and its Association with Well-Being
2010-12-31

Past research has shown that mindfulness meditation is useful for the attenuation of psychological and physical suffering in clinical populations. In structured mindfulness-based interventions, patients engage in meditation exercises to refine their attentional skills and to learn to purposefully relate to the present moment experience in a non-judgemental manner. Following the development of such interventions, mindfulness has also received considerable attention in academic psychology, where it has been incorporated in the self-determination theory (SDT). According to SDT, the cultivation of mindfulness may warrant effective need gratification and consequently yield enhanced well-being in healthy individuals. In this context, in the current study, we examined the association between mindfulness meditation, self-reported trait mindfulness and their predictive value for psychological well-being in a non-clinical sample. Individuals who engaged in mindfulness meditation regularly (N = 30) were compared to individuals without meditation experience (N = 30) on various scales which assessed trait mindfulness and psychological well-being. Meditators reported higher emotional well-being, which was predicted by frequency and duration of practice. Especially those practitioners, who made efforts to implement mindfulness practice in activities of everyday life showed enhanced emotional adjustment. In an explorative analysis, mindfulness was identified as a putative partial mediator of the relationship between meditation practice and well-being. Despite methodological constraints, results of the current study suggest that mindfulness meditation, in a non-clinical context, is associated with increased psychological well-being, and as such worth to be explored in more detail by future research. The study and its results might be relevant for the clinical sector as well, since they provide some information on how individuals with e.g., subclinical residual symptoms can protect themselves complementarily to CBT, but without participating in a completely structured mindfulness-based intervention.
Breath-Hold Diving
2010-12-31

BH diving with performance of GI does not permanently alter pulmonary distensibility or impair ventilatory flows and volumes. A blunted response to elevated CO2 concentrations could be demonstrated, which was supportive of the hypothesis that CO2 tolerance is a training effect due to BH diving rather than being an inherited phenomenon.
Point-Counterpoint: Haploidentical Family Donors versus Cord Blood Transplantation
2010-12-31

For patients who do not have a matched sibling donor or a volunteer matched unrelated donor, or when there is not enough time to line up a donor due to the rapid progression of the patient's disease, there are two rapidly available alternative stem cell donor sources: a haploidentical transplantation from a three-locus mismatched family member (parents, siblings, or children of the patients) [1Aversa F. Tabilio A. Velardi A. et al.Treatment of high-risk acute leukemia with T-cell-depleted stem cells from related donors with one fully mismatched HLA haplotype.N Engl J Med. 1998; 339: 1186-1193Crossref PubMed Scopus (1018) Google Scholar, 2Handgretinger R. Klingebiel T. Lang P. et al.Megadose transplantation of purified peripheral blood CD34(+) progenitor cells from HLA-mismatched parental donors in children.Bone Marrow Transplant. 2001; 27: 777-783Crossref PubMed Scopus (234) Google Scholar] or an unrelated cryopreserved umbilical cord blood (CB) from a CB bank [3Wagner J.E. Gluckman E. Umbilical cord blood transplantation: the first 20 years.Semin Hematol. 2010; 47: 3-12Abstract Full Text Full Text PDF PubMed Scopus (84) Google Scholar]. Until the advent of large unrelated donor panels, allogeneic stem cell transplants (SCT) using less than fully matched related donors were sporadically performed in situations where the risks of a mismatched transplant were matched by those of the underlying disease. With the availability of better than half-matched unrelated donors and the use of umbilical cord blood stem cell transplants (CBT) from 1990, the place of haploidentical-related SCT has become defined as an alternative to CBT when a fully matched donor is unavailable. The choice of CB versus haplo donor in this situation is worthy of debate. Practice around the world varies: for example, in the United States, CBT predominate. In contrast, curiously, in Europe, CBT were largely pioneered in countries speaking romance languages whereas teutonic language–speaking countries have been slow to adopt CBT. Here, we contrast the strengths and weaknesses of the two stem cell sources, as proposed by two experts in the field.
The Proof Theory of Partial Variables
2010-12-31

Post-Montagovian semanticists were not fully comfortable with this analysis. There is a common intuition that indefines are, or can be, referring expression, even if the referent is only known to the speaker, or not even to him. Formally speaking, indefinites “feel” like being of type e, despite all logical arguments to the contrary. Discourse Representation Theory implements this intuition to some degree by assuming that indefinites introduce a variable of type e into the semantic representation of the sentence or discourse where it occurs. However, strictly speaking an indefinite like a man does not only introduce a free variable but an open formula, like Mx, into the representation. So technically speaking, indefinites are of type t in DRT, which is even less intuitive than the Montagovian analysis. In a series of publications, Tanya Reinhart explored the empirical and logical consequences that result if indefinites are in fact taken to have the logical type e (Reinhart 1997; see also Winter 1997, Kratzer 1998 and much subsequent work). If one maintains the uncontroversial assumption that the head noun (plus its modifiers) in an indefinite DP expresses a property (type 〈e, t〉), the indefinite article must have type 〈〈e, t〉, e〉. If one grants the rather trivial assumption that the descriptive part of an indefinite should describe the object that is referred to, this entails that the indefinite article denotes a choice function.
Position statement. Part one: Immune function and exercise.
2011-01-01

An ever-growing volume of peer-reviewed publications speaks to the recent and rapid growth in both scope and understanding of exercise immunology. Indeed, more than 95% of all peer-reviewed publications in exercise immunology (currently >2, 200 publications using search terms "exercise" and "immune") have been published since the formation of the International Society of Exercise and Immunology (ISEI) in 1989 (ISI Web of Knowledge). We recognise the epidemiological distinction between the generic term "physical activity" and the specific category of "exercise", which implies activity for a specific purpose such as improvement of physical condition or competition. Extreme physical activity of any type may have implications for the immune system. However, because of its emotive component, exercise is likely to have a larger effect, and to date the great majority of our knowledge on this subject comes from exercise studies.
Of PAMPs and Effectors: The Blurred PTI-ETI Dichotomy
2011-01-01

Typically, pathogen-associated molecular patterns (PAMPs) are considered to be conserved throughout classes of microbes and to contribute to general microbial fitness, whereas effectors are species, race, or strain specific and contribute to pathogen virulence. Both types of molecule can trigger plant immunity, designated PAMP-triggered and effector-triggered immunity (PTI and ETI, respectively). However, not all microbial defense activators conform to the common distinction between PAMPs and effectors. For example, some effectors display wide distribution, while some PAMPs are rather narrowly conserved or contribute to pathogen virulence. As effectors may elicit defense responses and PAMPs may be required for virulence, single components cannot exclusively be referred to by one of the two terms. Therefore, we put forward that the distinction between PAMPs and effectors, between PAMP receptors and resistance proteins, and, therefore, also between PTI and ETI, cannot strictly be maintained. Rather, as illustrated by examples provided here, there is a continuum between PTI and ETI. We argue that plant resistance is determined by immune receptors that recognize appropriate ligands to activate defense, the amplitude of which is likely determined by the level required for effective immunity.
More Than Just Tumor Destruction: Immunomodulation by Thermal Ablation of Cancer
2011-01-01

Over the past decades, thermoablative techniques for the therapy of localized tumors have gained importance in the treatment of patients not eligible for surgical resection. Anecdotal reports have described spontaneous distant tumor regression after thermal ablation, indicating a possible involvement of the immune system, hence an induction of antitumor immunity after thermoinduced therapy. In recent years, a growing body of evidence for modulation of both adaptive and innate immunity, as well as for the induction of danger signals through thermoablation, has emerged. Induced immune responses, however, are mostly weak and not sufficient for the complete eradication of established tumors or durable prevention of disease progression, and combination therapies with immunomodulating drugs are being evaluated with promising results. This article aims to summarize published findings on immune modulation through radiofrequency ablation, cryoablation, microwave ablation therapy, high-intensity focused ultrasound, and laser-induced thermotherapy.
Current concepts of blood-brain barrier development
2011-01-01

Homeostasis of the central nervous system (CNS) microenvironment is essential for its normal function and is maintained by the blood-brain barrier (BBB). The BBB proper is made up of endothelial cells (ECs) interconnected by tight junctions (TJs) that reveal a unique morphology and biochemical composition of the body's vasculature. In this article, we focus on developmental aspects of the BBB and describe morphological as well as molecular special features of the neuro-vascular unit (NVU) involved in barrier induction. Recently, we and others identified the Wnt/b-catenin pathway as crucial for brain angiogenesis, TJ and BBB formation. Based on these findings we discuss other pathways and molecular interactions for BBB establishment and maintenance. At the morphological level, our concept favors a major role for polarized astrocytes (ACs) therein. Orthogonal arrays of particles (OAPs) that are the morphological correlate of the water channel protein aquaporin-4 (AQP4) are specifically formed in the membrane of the AC endfoot. The polarized AC endfoot and hence OAPs are dependent on agrin and dystroglycan, of which agrin is a developmentally regulated extracellular matrix (ECM) component. Understanding the mechanisms leading to BBB development will be key to the understanding of barrier maintenance that is crucial for, but frequently disturbed, in the diseased adult brain.
Cortical Network Dynamics of Perceptual Decision-Making in the Human Brain
2011-01-01

Goal-directed behavior requires the flexible transformation of sensory evidence about our environment into motor actions. Studies of perceptual decision-making have shown that this transformation is distributed across several widely separated brain regions. Yet, little is known about how decision-making emerges from the dynamic interactions among these regions. Here, we review a series of studies, in which we characterized the cortical network interactions underlying a perceptual decision process in the human brain. We used magnetoencephalography to measure the large-scale cortical population dynamics underlying each of the sub-processes involved in this decision: the encoding of sensory evidence and action plan, the mapping between the two, and the attentional selection of task-relevant evidence. We found that these sub-processes are mediated by neuronal oscillations within specific frequency ranges. Localized gamma-band oscillations in sensory and motor cortices reflect the encoding of the sensory evidence and motor plan. Large-scale oscillations across widespread cortical networks mediate the integrative processes connecting these local networks: Gamma- and beta-band oscillations across frontal, parietal, and sensory cortices serve the selection of relevant sensory evidence and its flexible mapping onto action plans. In sum, our results suggest that perceptual decisions are mediated by oscillatory interactions within overlapping local and large-scale cortical networks.
Extending the Mental Number Line
2011-01-01

Multi-digit number processing is ubiquitous in our everyday life – even in school, multi-digit numbers are computed from the first year onward. Yet, many problems children and adults have are about the relation of different digits (for instance with fractions, decimals, or carry effects in multi-digit addition). Cognitive research has mainly focused on single-digit processing, and there is no comprehensive review of the different multi-digit number processing types and effects. The current review aims to fill this gap. First, we argue that effects observed in single-digit tasks cannot simply be transferred to multi-digit processing. Next, we list 16 effect types and processes which are specific for multi-digit number processing. We then discuss the development of multi-digit number processing, its neurocognitive correlates, its cultural or language-related modulation, and finally some models for multi-digit number processing. We finish with conclusions and perspectives about where multi-digit number processing research may or should be heading in following years.
p38 MAPK Activation and Function following Osmotic Shock of Erythrocytes
2011-01-01

p38 protein kinase is activated by hyperosmotic shock, participates in the regulation of cell volume sensitive transport and metabolism and is involved in the regulation of various physiological functions including cell proliferation and apoptosis. Similar to apoptosis of nucleated cells, erythrocytes may undergo suicidal death or eryptosis, which is paralleled by cell shrinkage and cell membrane scrambling with phosphatidylserine exposure at the cell surface. Triggers of eryptosis include hyperosmotic shock, which increases cytosolic Ca(2+) activity and ceramide formation. The present study explored whether p38 kinase is expressed in human erythrocytes, is activated by hyperosmotic shock and participates in the regulation of eryptosis. Western blotting was utilized to determine phosphorylation of p38 kinase, forward scatter to estimate cell volume, annexin V binding to depict phosphatidylserine exposure and Fluo3 fluorescence to estimate cytosolic Ca(2+) activity. As a result, erythrocytes express p38 kinase, which is phosphorylated upon osmotic shock (+550 mM sucrose). Osmotic shock decreased forward scatter, increased annexin V binding and increased Fluo3 fluorescence, all effects significantly blunted by the p38 kinase inhibitors SB203580 (2 μM) and p38 Inh III (1 μM). In conclusion, p38 kinase is expressed in erythrocytes and participates in the machinery triggering eryptosis following hyperosmotic shock.
Adenosine Generation and Signaling during Acute Kidney Injury
2011-01-01

Acute kidney injury (AKI) is among the leading causes of morbidity and mortality in hospitalized patients. Particularly in the perioperative period, the most common cause of AKI is renal ischemia. At present, therapeutic modalities to prevent or treat AKI are extremely limited and the search for novel therapeutic interventions for ischemic AKI is an area of intense investigation. Recent studies implicate the endogenous signaling molecule, adenosine, in kidney protection from ischemia. As such, enzymatic production of adenosine from its precursor molecules ATP and AMP, and signaling events through adenosine receptors, play a critical role in attenuating renal inflammation and preserving kidney function during episodes of renal ischemia. Utilizing genetic mouse models with defects in adenosine generation or signaling provide strong evidence for the key role of extracellular adenosine in adapting renal tissues to limited oxygen availability and attenuating hypoxia-driven inflammation of the kidneys. Moreover, experimental therapeutics targeting individual adenosine receptors demonstrate strong prophylactic or therapeutic effects during murine AKI. If these experimental strategies can be translated into a clinical setting, adenosine receptor therapeutics may become an integral part in the prevention or treatment of AKI from renal ischemia.
Janus Kinase 3 is Expressed in Erythrocytes, Phosphorylated Upon Energy Depletion and Involved in the Regulation of Suicidal Erythrocyte Death
2011-01-01

Janus kinase 3, a tyrosine kinase expressed in haematopoetic tissues, plays a decisive role in T-lymphocyte survival. JAK3 deficiency leads to (Severe) Combined Immunodeficiency (SCID) resulting from enhanced lymphocyte apoptosis. JAK3 is activated by phosphorylation. Nothing is known about expression of JAK3 in erythrocytes, which may undergo apoptosis-like cell death (eryptosis) characterized by cell membrane scrambling with phosphatidylserine exposure and cell shrinkage. Triggers of eryptosis include energy depletion. The present study utilized immunohistochemistry and confocal microscopy to test for JAK3 expression and phosphorylation, and FACS analysis to determine phosphatidylserine exposure (annexin binding) and cell volume (forward scatter). As a result, JAK3 was expressed in erythrocytes and phosphorylated following 24h and 48h glucose depletion. Forward scatter was slightly but significantly smaller in erythrocytes from JAK3-deficient mice (jak3-/-) than in erythrocytes from wild type mice (jak3+/+). Annexin V binding was similarly low in both genotypes. The JAK3 inhibitors WHI-P131/JANEX-1 (4-(4′-Hydroxyphenyl)amino-6,7-dimethoxyquinazoline, 156μM) and WHI-P154 (4-[(3′-Bromo-4′-hydroxyphenyl)amino]-6,7-dimethoxyquinazoline, 11.2μM) did not significantly modify annexin V binding or forward scatter. Glucose depletion increased annexin V binding, an effect significantly blunted in jak3-/- erythrocytes and in the presence of the JAK3 inhibitors. The observations disclose a completely novel role of Janus kinase 3, i.e. the triggering of cell membrane scrambling in energy depleted erythrocytes.
The NFĸB Pathway Inhibitors Bay 11-7082 and Parthenolide Induce Programmed Cell Death in Anucleated Erythrocytes
2011-01-01

The preclinical compounds Bay 11-7082 and parthenolide trigger apoptosis, an effect contributing to their antiinflammatory action. The substances interfere with the activation and nuclear translocation of nuclear factor NFκB, by inhibiting NFκB directly (parthenolide) or by interfering with the inactivation of the NFκB inhibitory protein IκB-α (Bay 11-7082). Beyond that, the substances may be effective in part by nongenomic effects. Similar to apoptosis of nucleated cells, erythrocytes may undergo apoptosis-like cell death (eryptosis) characterized by cell membrane scrambling with phosphatidylserine exposure, and cell shrinkage. Thus, erythrocytes allow the study of nongenomic mechanisms contributing to suicidal cell death, e.g. Ca(2+) leakage or glutathione depletion. The present study utilized Western blotting to search for NFκB and IκB-α expression in erythrocytes, FACS analysis to determine cytosolic Ca(2+) (Fluo3 fluorescence), phosphatidylserine exposure (annexin V binding), and cell volume (forward scatter), as well as an enzymatic method to determine glutathione levels. As a result, both NFκB and IκB-α are expressed in erythrocytes. Targeting the NFκB pathway by Bay 11-7082 (IC(50) ≈ 10 μM) and parthenolide (IC(50) ≈ 30 μM) triggered suicidal erythrocyte death as shown by annexin V binding and decrease of forward scatter. Bay 11-7082 treatment further increased intracellular Ca(2+) and led to depletion of reduced glutathione. The effects of Bay 11-7082 and parthenolide on annexin V binding could be fully reversed by the antioxidant N-acetylcysteine. In conclusion, the pharmacological inhibitors of NFκB, Bay 11-7082 and parthenolide, interfere with the survival of erythrocytes involving mechanisms other than disruption of NFκB-dependent gene expression.
Individual Differences in Audio-Vocal Speech Imitation Aptitude in Late Bilinguals: Functional Neuro-Imaging and Brain Morphology
2011-01-01

An unanswered question in adult language learning or late bi and multilingualism is why individuals show marked differences in their ability to imitate foreign accents. While recent research acknowledges that more adults than previously assumed can still acquire a "native" foreign accent, very little is known about the neuro-cognitive correlates of this special ability. We investigated 140 German-speaking individuals displaying varying degrees of "mimicking" capacity, based on natural language text, sentence, and word imitations either in their second language English or in Hindi and Tamil, languages they had never been exposed to. The large subject pool was strictly controlled for previous language experience prior to magnetic resonance imaging. The late-onset (around 10 years) bilinguals showed significant individual differences as to how they employed their left-hemisphere speech areas: higher hemodynamic activation in a distinct fronto-parietal network accompanied low ability, while high ability paralleled enhanced gray matter volume in these areas concomitant with decreased hemodynamic responses. Finally and unexpectedly, males were found to be more talented foreign speech mimics.