julilili42/papers huggingface dataset:
A Fluorescence-Based Synthetic LPS Sensor
2006-12-30

For the detection of bioanalytes, there is an ongoing search for synthetic sensors to replace enzyme-based assays which are sensitive to contaminants or suboptimal storage conditions. Lipopolysaccharide (LPS), a bacteria-borne endotoxin that may lead to life-threatening conditions such as septic shock, is one such case. Fluorescently labeled analogues of two peptide variants derived from the putative ligand-binding domain of the LPS-binding protein CD14 were developed that detect and discriminate LPS and lipids down to the submicromolar concentration range. Peptides are terminally labeled with carboxyfluorescein and tetramethylrhodamine. For one given peptide, sensitivity and specificity for the detection of LPS and discrimination from other lipids are achieved by spectral signatures that combine changes in the fluorescence resonance energy transfer (FRET) between both dyes and the total emission of tetramethylrhodamine. Alternatively, specificity is obtained by combining the FRET efficiencies of both peptide variants. In comparison to published synthetic LPS sensors, the CD14-derived sensors yield an increase in sensitivity by about 3 orders of magnitude and exhibit specificity for analytes for which the design of synthetic recognition elements is a challenging task. Moreover, one of the sensors enabled the detection of LPS in the presence of up to 50% fetal calf serum, thereby demonstrating the feasibility of this peptide-based approach for clinically relevant samples.
Feeding ecology in the small neotropical amphisbaenid Amphisbaena munoai (Amphisbaenidae) in southern Brazil
2006-12-30

We analyzed the alimentary tract of 66 specimens of Amphisbaena munoai Klappenbach, 1969 from the Serra do Sudeste, state of Rio Grande do Sul, southern Brazil. Forty specimens (60.6%) had prey items in their gut. The diet consisted mainly of small invertebrate prey, such as termites, insect larvae and ants. The most abundant prey item was termites, found in 62.5% of the non empty stomachs. The high number of individual prey items in the majority of stomachs, the small size of the regular prey items, and the absence of gut content in specimens of A. munoai kept alive for about two days, indicate that this species forages very frequently. The predominance of fossorial prey items and the occasional records of nomadic ants lead us to suggest that A. munoai usually feeds underground, and occasionally forages on the surface.
A study of immigrant entrepreneurship in Upper Bavaria
2006-12-30

The objective of the present paper is to answer the question: To what extent does investment in human and social capital enhance the immigrants' entrepreneurial performance in Upper Bavaria? The analysis is based on representative data set from the Chamber of Industrial and Commercial Matters in Munich, Germany. It consists of 114,550 companies that were either founded or liquidated in Upper Bavaria. The data on enterprise establishments are available for the period 1990–1994, and on liquidations for 1990–1997. We develop a parametric hazard rate model to predict the survival chances of newly founded businesses between natives of, and immigrants to, Germany. The main finding suggests that the endowed level of human capital of a business founder is not the unique determinant of performance. Rather, investment in industry-specific and entrepreneurship-specific human and social capital contributes significantly to the explanation of the cross-sectional variance of the performance of entrepreneurs.
Interactions among PIN-FORMED and P-Glycoprotein Auxin Transporters in Arabidopsis
2007-01-01

Abstract Directional transport of the phytohormone auxin is established primarily at the point of cellular efflux and is required for the establishment and maintenance of plant polarity. Studies in whole plants and heterologous systems indicate that PIN-FORMED (PIN) and P-glycoprotein (PGP) transport proteins mediate the cellular efflux of natural and synthetic auxins. However, aromatic anion transport resulting from PGP and PIN expression in nonplant systems was also found to lack the high level of substrate specificity seen in planta. Furthermore, previous reports that PGP19 stabilizes PIN1 on the plasma membrane suggested that PIN–PGP interactions might regulate polar auxin efflux. Here, we show that PGP1 and PGP19 colocalized with PIN1 in the shoot apex in Arabidopsis thaliana and with PIN1 and PIN2 in root tissues. Specific PGP–PIN interactions were seen in yeast two-hybrid and coimmunoprecipitation assays. PIN–PGP interactions appeared to enhance transport activity and, to a greater extent, substrate/inhibitor specificities when coexpressed in heterologous systems. By contrast, no interactions between PGPs and the AUXIN1 influx carrier were observed. Phenotypes of pin and pgp mutants suggest discrete functional roles in auxin transport, but pin pgp mutants exhibited phenotypes that are both additive and synergistic. These results suggest that PINs and PGPs characterize coordinated, independent auxin transport mechanisms but also function interactively in a tissue-specific manner.
Molecular Mechanisms of Schizophrenia
2007-01-01

Schizophrenia is a complex disorder, where family, twin and adoption studies have been demonstrating a high heritability of the disease and that this disease is not simply defined by several major genes but rather evolves from addition or potentiation of a specific cluster of genes, which subsequently determines the genetic vulnerability of an individual. Linkage and association studies suggest that a genetic vulnerablility, is not forcefully leading to the disease since triggering factors and environmental influences, i.e. birth complications, drug abuse, urban background or time of birth have been identified. This has lead to the assumption that schizophrenia is not only a genetically defined static disorder but a dynamic process leading to dysregulation of multiple pathways. There are several different hypothesis based on several facets of the disease, some of them due to the relatively well-known mechanisms of therapeutic agents. The most widely considered neurodevelopmental hypothesis of schizophrenia integrates environmental influences and causative genes. The dopamine hypothesis of schizophrenia is based on the fact that all common treatments involve antidopaminergic mechanisms and genes such as DRD2, DRD3, DARPP-32, BDNF or COMT are closely related to dopaminergic system functioning. The glutamatergic hypothesis of schizophrenia lead recently to a first successful mGlu2/3 receptor agonistic drug and is underpinned by significant findings in genes regulating the glutamatergic system (SLC1A6, SLC1A2 GRIN1, GRIN2A, GRIA1, NRG1, ErbB4, DTNBP1, DAAO, G72/30, GRM3). Correspondingly, GABA has been proposed to modulate the pathophysiology of the disease which is represented by the involvement of genes like GABRA1, GABRP, GABRA6 and Reelin. Moreover, several genes implicating immune, signaling and networking deficits have been reported to be involved in the disease, i.e. DISC1, RGS4, PRODH, DGCR6, ZDHHC8, DGCR2, Akt, CREB, IL-1B, IL-1RN, IL-10, IL-1B. However, molecular findings suggest that a complex interplay between receptors, kinases, proteins and hormones is involved in schizophrenia. In a unifying hypothesis, different cascades merge into another that ultimately lead to the development of symptoms adherent to schizophrenic disorders.
Dynamical Low‐Rank Approximation
2007-01-01

For the low‐rank approximation of time‐dependent data matrices and of solutions to matrix differential equations, an increment‐based computational approach is proposed and analyzed. In this method, the derivative is projected onto the tangent space of the manifold of rank‐r matrices at the current approximation. With an appropriate decomposition of rank‐r matrices and their tangent matrices, this yields nonlinear differential equations that are well suited for numerical integration. The error analysis compares the result with the pointwise best approximation in the Frobenius norm. It is shown that the approach gives locally quasi‐optimal low‐rank approximations. Numerical experiments illustrate the theoretical results.
fMRI Brain-Computer Interface: A Tool for Neuroscientific Research and Treatment
2007-01-01

Brain-computer interfaces based on functional magnetic resonance imaging (fMRI-BCI) allow volitional control of anatomically specific regions of the brain. Technological advancement in higher field MRI scanners, fast data acquisition sequences, preprocessing algorithms, and robust statistical analysis are anticipated to make fMRI-BCI more widely available and applicable. This noninvasive technique could potentially complement the traditional neuroscientific experimental methods by varying the activity of the neural substrates of a region of interest as an independent variable to study its effects on behavior. If the neurobiological basis of a disorder (e.g., chronic pain, motor diseases, psychopathy, social phobia, depression) is known in terms of abnormal activity in certain regions of the brain, fMRI-BCI can be targeted to modify activity in those regions with high specificity for treatment. In this paper, we review recent results of the application of fMRI-BCI to neuroscientific research and psychophysiological treatment.
Mastocytosis: State of the Art
2007-01-01

Mastocytosis is a neoplastic disease involving mast cells (MC) and their CD34+ progenitors. Symptoms in mastocytosis are caused by biological mediators released from MC and/or the infiltration of neoplastic MC in various organs, the skin and the bone marrow being predominantly involved. A WHO consensus classification for mastocytosis exists, which is widely accepted and includes three major categories: (1) Cutaneous mastocytosis (CM), a benign disease in which MC infiltration is confined to the skin, is preferentially seen in young children and exhibits a marked tendency to regress spontaneously. (2) Systemic mastocytosis (SM) which is commonly diagnosed in adults and includes four major subtypes: (i) indolent SM (ISM, the most common form involving mainly skin and bone marrow); (ii) a unique subcategory termed SM with an associated non-mast cell clonal hematological disease (SM-AHNMD); (iii) aggressive SM usually presenting without skin lesions, and (iv) MC leukemia, probably representing the rarest variant of human leukemias. (3) The extremely rare localized extracutaneous MC neoplasms, either presenting as malignancy (MC sarcoma) or as benign tumor termed extracutaneous mastocytoma. Diagnostic criteria for mastocytosis are available and are widely accepted. SM criteria include one major criterion (multifocal compact tissue infiltration by MC) and four minor criteria: (1) prominent spindling of MC; (2) atypical immunophenotype of MC with coexpression of CD2 and/or CD25 (antigens which have not been found to be expressed on normal/reactive MC); (3) activating (somatic) point mutations of the c-kit proto-oncogene usually involving exon 17, with the imatinib-resistant type D816V being most frequent, and (4) persistently elevated serum tryptase level (&gt;20 ng/ml). To establish the diagnosis of SM, at least one major and one minor criterion, or at least three minor criteria, have to be fulfilled. The natural clinical course of mastocytosis is variable. Most patients, in particular those with CM and ISM, remain in an indolent stage over many years or even decades, while others, in particular those with aggressive SM, SM-AHNMD, or mast cell leukemia, show a progressive course, usually with a fatal outcome.
The Chemopreventive Polyphenol Curcumin Prevents Hematogenous Breast Cancer Metastases in Immunodeficient Mice
2007-01-01

Dissemination of metastatic cells probably occurs long before diagnosis of the primary tumor. Metastasis during early phases of carcinogenesis in high risk patients is therefore a potential prevention target. The plant polyphenol Curcumin has been proposed for dietary prevention of cancer. We therefore examined its effects on the human breast cancer cell line MDA-MB-231 in vitroand in a mouse metastasis model. Curcumin strongly induces apoptosis in MDA-MB-231 cells in correlation with reduced activation of the survival pathway NFkappaB, as a consequence of diminished IotakappaB and p65 phosphorylation. Curcumin also reduces the expression of major matrix metalloproteinases (MMPs) due to reduced NFkappa B activity and transcriptional downregulation of AP-1. NFkappa B/p65 silencing is sufficient to downregulate c-jun and MMP expression. Reduced NFkappa B/AP-1 activity and MMP expression lead to diminished invasion through a reconstituted basement membrane and to a significantly lower number of lung metastases in immunodeficient mice after intercardiac injection of 231 cells (p=0.0035). 68% of Curcumin treated but only 17% of untreated animals showed no or very few lung metastases, most likely as a consequence of down-regulation of NFkappa B/AP-1 dependent MMP expression and direct apoptotic effects on circulating tumor cells but not on established metastases. Dietary chemoprevention of metastases appears therefore feasible.
Radiation-induced EGFR-signaling and control of DNA-damage repair
2007-01-01

The novel findings on radiation-induced EGFR-signaling and its involvement in regulating DNA-double strand break repair need further investigations of the detailed mechanisms involved. The results to be obtained may not only improve our knowledge on basic mechanisms of radiation sensitivity/resistance but also will promote translational approaches to test new strategies for clinically applicable molecular targeting.
Response and adaptation of skeletal muscle to exercise - the role of reactive oxygen species
2007-01-01

In the last 30 years, the role of reactive oxygen species (ROS) in exercise physiology has received considerable attention. Acute physical exertion has been shown to induce an augmented generation of ROS in skeletal muscle via different mechanisms. There is evidence that ROS formation in response to vigorous physical exertion can result in oxidative stress. More recent research has revealed the important role of ROS as signaling molecules. ROS modulate contractile function in unfatigued and fatigued skeletal muscle. Furthermore, involvement of ROS in the modulation of gene expression via redox-sensitive transcription pathways represents an important regulatory mechanism, which has been suggested to be involved in the process of training adaptation. In this context, the adaptation of endogenous antioxidant systems in response to regular training reflects a potential mechanism responsible for augmented tolerance of skeletal muscle to exercise-induced stress. The present review outlines current knowledge and more recent findings in this area by focussing on major sources of ROS production, oxidative stress, tissue damage, contractile force, and redox-regulated gene expression in exercising skeletal muscle.
Update on the genetics of Parkinson's disease
2007-01-01

Over the last few years, several genes for monogenic forms of Parkinson's disease (PD) have been mapped and/or cloned. Mutations have been identified in the gene for alpha-synuclein in rare families with dominant PD, indicating that aggregation of this protein in Lewy bodies is probably a crucial step in the molecular pathogenesis of the disorder. A much more common cause for dominant PD, mutations in the gene for leucine-rich repeat kinase 2 (LRRK2), has recently been identified. Mutations in the parkin gene, in DJ-1 and PINK1 all cause autosomal recessive parkinsonism of early onset. These genes have been implicated in the proteasomal protein degradation pathway, in the oxidative stress response and mitochondrial function. Mutations in recessive genes probably are pathogenic through loss-of-function mechanisms, suggesting that their wildtype products protect dopaminergic cells against a variety of insults. Evidence is emerging that at least some of these genes may play a direct role in the etiology of the common sporadic form of PD. Further, it is likely that the cellular pathways identified in rare monogenic variants of the disease also shed light on the molecular pathogenesis in typical sporadic PD.
Online Artifact Removal for Brain-Computer Interfaces Using Support Vector Machines and Blind Source Separation
2007-01-01

We propose a combination of blind source separation (BSS) and independent component analysis (ICA) (signal decomposition into artifacts and nonartifacts) with support vector machines (SVMs) (automatic classification) that are designed for online usage. In order to select a suitable BSS/ICA method, three ICA algorithms (JADE, Infomax, and FastICA) and one BSS algorithm (AMUSE) are evaluated to determine their ability to isolate electromyographic (EMG) and electrooculographic (EOG) artifacts into individual components. An implementation of the selected BSS/ICA method with SVMs trained to classify EMG and EOG artifacts, which enables the usage of the method as a filter in measurements with online feedback, is described. This filter is evaluated on three BCI datasets as a proof-of-concept of the method.
Psychological burden of food allergy
2007-01-01

One fifth of the population report adverse reactions to food. Reasons for these symptoms are heterogeneous, varying from food allergy, food intolerance, irritable bowel syndrome to somatoform or other mental disorders. Literature reveals a large discrepancy between truly diagnosed food allergy and reports of food allergy symptoms by care seekers. In most studies currently available the characterization of patient groups is incomplete, because they did not distinguish between immunologic reactions and other kinds of food reactions. In analysing these adverse reactions, a thorough physical and psychological diagnostic approach is important. In our qualitative review, we present those diagnostic measures that are evidence-based as well as clinically useful, and discuss the various psychological dimensions of adverse reactions to food. It is important to acknowledge the complex interplay between body and mind: Adults and children suffering from food allergy show impaired quality of life and a higher level of stress and anxiety. Pavlovian conditioning of adverse reactions plays an important role in maintaining symptoms. The role of personality, mood, or anxiety in food reactions is debatable. Somatoform disorders ought to be identified early to avoid lengthy and frustrating investigations. A future task will be to improve diagnostic algorithms, to describe psychological aspects in clearly characterised patient subgroups, and to develop strategies for an optimized management of the various types of adverse reactions to food.
Age at Growth Hormone Therapy Start and First-Year Responsiveness to Growth Hormone Are Major Determinants of Height Outcome in Idiopathic Short Stature
2007-01-01

&lt;i&gt;Aim:&lt;/i&gt; To develop methods to identify factors associated with a favorable outcome in GH-treated children with idiopathic short stature (ISS). &lt;i&gt;Methods:&lt;/i&gt; From 4,685 children listed as having ISS within KIGS (Pfizer International Growth Database), we studied (a) the prediction model group (n = 657) to develop the first-year prediction model, and (b) the near adult height group (NAH; n = 256) which received GH for &gt;4 years to develop descriptive models for adult height and overall height gain. &lt;i&gt;Results:&lt;/i&gt; NAH group at GH start: age was 10.0 years, height –2.5 SD score (SDS), weight –2.3 SDS, height minus mid-parental height (MPH) –1.5 SDS; GH dose 0.19 mg/kg/week. Height gain was 1.1 SDS at a median age of 17.2 years. Growth response correlated positively with GH dose and weight at the start of GH treatment, and negatively with age and height SDS minus MPH SDS. The model explains 39% (error SD 1.2 cm) of the variability. Adult height correlated (R&lt;sup&gt;2&lt;/sup&gt; = 0.64) positively with height at GH start, MPH and the first-year responsiveness to GH, and negatively with age. &lt;i&gt;Conclusions:&lt;/i&gt; Prepubertal children with ISS who show an appropriate first-year response to GH are likely to benefit from long-term treatment, even on low GH dosages.
Imaging of tumor hypoxia with [124I]IAZA in comparison with [18F]FMISO and [18F]FAZA--first small animal PET results.
2007-01-01

[18F]FAZA showed superior biokinetics compared to [18F]FMISO and [124I]IAZA in this study. Imaging at later time points that are not possible with the short lived 18F labeled tracers resulted in no advantage for [124I]IAZA, i. e. tumor to normal tissue ratios could not be improved.
Differences in plaque composition and distribution in stable coronary artery disease versus acute coronary syndromes; non‐invasive evaluation with multi‐slice computed tomography
2007-01-01

In patients with ACS, significantly less calcifications were present as compared to stable CAD. Moreover, even in non-culprit vessels, multiple non-calcified plaques were detected, indicating diffuse rather than focal atherosclerosis in ACS.
Nessi: An EEG-Controlled Web Browser for Severely Paralyzed Patients
2007-01-01

We have previously demonstrated that an EEG-controlled web browser based on self-regulation of slow cortical potentials (SCPs) enables severely paralyzed patients to browse the internet independently of any voluntary muscle control. However, this system had several shortcomings, among them that patients could only browse within a limited number of web pages and had to select links from an alphabetical list, causing problems if the link names were identical or if they were unknown to the user (as in graphical links). Here we describe a new EEG-controlled web browser, called Nessi, which overcomes these shortcomings. In Nessi, the open source browser, Mozilla, was extended by graphical in-place markers, whereby different brain responses correspond to different frame colors placed around selectable items, enabling the user to select any link on a web page. Besides links, other interactive elements are accessible to the user, such as e-mail and virtual keyboards, opening up a wide range of hypertext-based applications.
Virtual reality for the psychophysiological assessment of phobic fear: Responses during virtual tunnel driving.
2007-01-01

An overall assessment of phobic fear requires not only a verbal self-report of fear but also an assessment of behavioral and physiological responses. Virtual reality can be used to simulate realistic (phobic) situations and therefore should be useful for inducing emotions in a controlled, standardized way. Verbal and physiological fear reactions were examined in 15 highly tunnel-fearful and 15 matched control participants in 3 virtual driving scenarios: an open environment, a partially open tunnel (gallery), and a closed tunnel. Highly tunnel-fearful participants were characterized by elevated fear responses specifically during tunnel drives as reflected in verbal fear ratings, heart rate reactions, and startle responses. Heart rate and fear ratings differentiated highly tunnel-fearful from control participants with an accuracy of 88% and 93%, respectively. Results indicate that virtual environments are valuable tools for the assessment of fear reactions and should be used in future experimental research.