Showing papers by "University of Graz published in 2009"
Institut Gustave Roussy1, French Institute of Health and Medical Research2, University of Paris-Sud3, Icahn School of Medicine at Mount Sinai4, University of Texas Southwestern Medical Center5, Thomas Jefferson University6, McMaster University7, University of Massachusetts Medical School8, LSU Health Sciences Center New Orleans9, Roswell Park Cancer Institute10, Boston Children's Hospital11, University of Gothenburg12, University of Freiburg13, University of California, San Francisco14, Buck Institute for Research on Aging15, Centre national de la recherche scientifique16, National Institutes of Health17, Technion – Israel Institute of Technology18, University of Leicester19, University of Chieti-Pescara20, Istituto Superiore di Sanità21, University of North Carolina at Chapel Hill22, New York University23, University of Pennsylvania24, Yale University25, Howard Hughes Medical Institute26, University of Ulm27, University of Burgundy28, Aix-Marseille University29, Pasteur Institute30, University of Strasbourg31, Johns Hopkins University32, University of Zurich33, University of Tokyo34, Weizmann Institute of Science35, University of Michigan36, University College London37, Duke University38, University of Graz39, Ghent University40, Trinity College, Dublin41, University of Amsterdam42, University of Lyon43, University of Rome Tor Vergata44, University of Göttingen45, Stony Brook University46, Kyoto University47, Merck & Co.48, Austrian Academy of Sciences49, National University of Singapore50, University of Chicago51, Royal College of Surgeons in Ireland52, La Trobe University53, University of Buenos Aires54, University of Padua55, University of Lisbon56, University of Cambridge57, University of Würzburg58, University of Geneva59, University of Bern60, Rockefeller University61, University of Lausanne62, Osaka University63, University of California, San Diego64, University of Glasgow65, Harvard University66, Karolinska Institutet67
TL;DR: A nonexhaustive comparison of methods to detect cell death with apoptotic or nonapoptotic morphologies, their advantages and pitfalls is provided and the importance of performing multiple, methodologically unrelated assays to quantify dying and dead cells is emphasized.
Abstract: Cell death is essential for a plethora of physiological processes, and its deregulation characterizes numerous human diseases Thus, the in-depth investigation of cell death and its mechanisms constitutes a formidable challenge for fundamental and applied biomedical research, and has tremendous implications for the development of novel therapeutic strategies It is, therefore, of utmost importance to standardize the experimental procedures that identify dying and dead cells in cell cultures and/or in tissues, from model organisms and/or humans, in healthy and/or pathological scenarios Thus far, dozens of methods have been proposed to quantify cell death-related parameters However, no guidelines exist regarding their use and interpretation, and nobody has thoroughly annotated the experimental settings for which each of these techniques is most appropriate Here, we provide a nonexhaustive comparison of methods to detect cell death with apoptotic or nonapoptotic morphologies, their advantages and pitfalls These guidelines are intended for investigators who study cell death, as well as for reviewers who need to constructively critique scientific reports that deal with cellular demise Given the difficulties in determining the exact number of cells that have passed the point-of-no-return of the signaling cascades leading to cell death, we emphasize the importance of performing multiple, methodologically unrelated assays to quantify dying and dead cells
2,218 citations
University of Graz1, Joanneum Research2, Institute of Molecular Biotechnology3, Research Institute of Molecular Pathology4, University of Natural Resources and Life Sciences, Vienna5, Foundation for Research & Technology – Hellas6, Austrian Academy of Sciences7, University of Salzburg8, University of Basel9, University of St Andrews10
TL;DR: This article showed that spermidine, a natural polyamine whose intracellular concentration declines during human ageing, markedly extended the lifespan of yeast, flies and worms, and human immune cells.
Abstract: Ageing results from complex genetically and epigenetically programmed processes that are elicited in part by noxious or stressful events that cause programmed cell death. Here, we report that administration of spermidine, a natural polyamine whose intracellular concentration declines during human ageing, markedly extended the lifespan of yeast, flies and worms, and human immune cells. In addition, spermidine administration potently inhibited oxidative stress in ageing mice. In ageing yeast, spermidine treatment triggered epigenetic deacetylation of histone H3 through inhibition of histone acetyltransferases (HAT), suppressing oxidative stress and necrosis. Conversely, depletion of endogenous polyamines led to hyperacetylation, generation of reactive oxygen species, early necrotic death and decreased lifespan. The altered acetylation status of the chromatin led to significant upregulation of various autophagy-related transcripts, triggering autophagy in yeast, flies, worms and human cells. Finally, we found that enhanced autophagy is crucial for polyamine-induced suppression of necrosis and enhanced longevity.
1,230 citations
TL;DR: The International Lipid Classification and Nomenclature Committee under the sponsorship of the LIPID MAPS Consortium developed and established a "Comprehensive Classification System for Lipids" based on well defined chemical and biochemical principles and using an ontology that is extensible, flexible, and scalable as mentioned in this paper.
1,219 citations
TL;DR: A clear definition of pulmonary hypertension and the development of a rational approach to diagnostic assessment and follow-up using both conventional and new tools will be essential to deriving maximal benefit from the expanding therapeutic armamentarium.
1,023 citations
TL;DR: In this article, a large series of patients treated with radical nephroureterectomy for urothelial carcinoma were studied, and variables associated with poor prognosis were identified.
Abstract: BACKGROUND: The literature on upper tract urothelial carcinoma (UTUC) has been limited to small, single center studies. A large series of patients treated with radical nephroureterectomy for UTUC were studied, and variables associated with poor prognosis were identified. METHODS: Data on 1363 patients treated with radical nephroureterectomy at 12 academic centers were collected. All pathologic slides were rereviewed by genitourinary pathologists according to strict criteria. RESULTS: Pathologic review revealed renal pelvis location (64%), necrosis (21.6%), lymphovascular invasion (LVI) (24.8%), concomitant carcinoma in situ (28.7%), and high-grade disease (63.7%). A total of 590 patients (43.3%) underwent concurrent, lymphadenectomy and 135 (9.9%) were lymph node (LN) -positive. Over a mean follow-up of 51 months, 379 (28%) patients experienced disease recurrence outside of the bladder and 313 (23%) died of UTUC. The 5-year recurrence-free and cancer-specific survival probabilities (� SD) were 69% � 1% and 73% � 1%, respectively. On multivariate analysis, high tumor grade (hazards ratio [HR]: 2.0, P < .001), advancing pathologic T stage (P-for-trend <.001), LN metastases (HR: 1.8, P < .001), infiltrative growth pattern (HR: 1.5, P < .001), and LVI (HR: 1.2, P ¼ .041) were associated with disease recurrence. Similarly, patient age (HR: 1.1, P ¼ .001), high tumor grade (HR: 1.7, P ¼ .001), increasing pathologic T stage (P-for-trend <.001), LN metastases (HR: 1.7, P < .001), sessile architecture (HR: 1.5, P ¼ .002), and LVI (HR: 1.4, P ¼ .02) were independently associated with cancer-specific survival. CONCLUSIONS: Radical nephroureterectomy provided durable local control and cancer-specific survival in patients with localized UTUC. Pathologic tumor grade, T stage, LN status, tumor architecture, and LVI were important prognostic variables associated with
897 citations
TL;DR: While P̄pa at rest is virtually independent of age and rarely exceeds 20 mmHg, exercise P⩽pa is age-related and frequently exceeds 30’s of pressure, especially in elderly individuals, which makes it difficult to define normal Ṕpa values during exercise.
Abstract: According to current guidelines, pulmonary arterial hypertension (PAH) is diagnosed when mean pulmonary arterial pressure (Ppa) exceeds 25 mmHg at rest or 30 mmHg during exercise. Issues that remain unclear are the classification of Ppa values 30 mmHg during exercise is always pathological. We performed a comprehensive literature review and analysed all accessible data obtained by right heart catheter studies from healthy individuals to determine normal Ppa at rest and during exercise. Data on 1,187 individuals from 47 studies in 13 countries were included. Data were stratified for sex, age, geographical origin, body position and exercise level. Ppa at rest was 14.0+/-3.3 mmHg and this value was independent of sex and ethnicity. Resting Ppa was slightly influenced by posture (supine 14.0+/-3.3 mmHg, upright 13.6+/-3.1 mmHg) and age ( or = 50 yrs: 14.7+/-4.0 mmHg). Ppa during exercise was dependent on exercise level and age. During mild exercise, Ppa was 19.4+/-4.8 mmHg in subjects aged or = 50 yrs (p<0.001). In conclusion, while Ppa at rest is virtually independent of age and rarely exceeds 20 mmHg, exercise Ppa is age-related and frequently exceeds 30 mmHg, especially in elderly individuals, which makes it difficult to define normal Ppa values during exercise.
880 citations
TL;DR: Depletion of PERK, caspase‐8 or SNAREs had no effect on cell death induced by anthracyclines, yet abolished the immunogenicity of cell death, which could be restored by absorbing recombinant CRT to the cell surface.
Abstract: Dying tumour cells can elicit a potent anticancer immune response by exposing the calreticulin (CRT)/ERp57 complex on the cell surface before the cells manifest any signs of apoptosis. Here, we enumerate elements of the pathway that mediates pre-apoptotic CRT/ERp57 exposure in response to several immunogenic anticancer agents. Early activation of the endoplasmic reticulum (ER)-sessile kinase PERK leads to phosphorylation of the translation initiation factor eIF2α, followed by partial activation of caspase-8 (but not caspase-3), caspase-8-mediated cleavage of the ER protein BAP31 and conformational activation of Bax and Bak. Finally, a pool of CRT that has transited the Golgi apparatus is secreted by SNARE-dependent exocytosis. Knock-in mutation of eIF2α (to make it non-phosphorylatable) or BAP31 (to render it uncleavable), depletion of PERK, caspase-8, BAP31, Bax, Bak or SNAREs abolished CRT/ERp57 exposure induced by anthracyclines, oxaliplatin and ultraviolet C light. Depletion of PERK, caspase-8 or SNAREs had no effect on cell death induced by anthracyclines, yet abolished the immunogenicity of cell death, which could be restored by absorbing recombinant CRT to the cell surface.
682 citations
TL;DR: It is concluded that neural efficiency might arise when individuals are confronted with tasks of (subjectively) low to moderate task difficulty and it is mainly observable for frontal brain areas.
654 citations
TL;DR: In this article, a review of the electrochemistry and electroanalytical applications of carbon paste-based electrodes, sensors, and detectors is presented on the occasion of the half-of-century anniversary since the discovery of carbon powder.
Abstract: This article reviews the electrochemistry and electroanalytical applications of carbon paste-based electrodes, sensors, and detectors on the occasion of the half-of-century anniversary since the discovery of carbon paste. The review (with 333 references) has been prepared in the form of a retrospective compilation presenting the field by means of various facts, notes, data, surveys, and summaries, including numerous rarities or curiosities that illustrate the individual achievements and milestones. Carbon paste-based electrodes are discussed in their entirety by covering all important areas of the field, starting from basic characterization of carbon paste as the electrode material, via its typical physicochemical and electrochemical properties or specific features, up to a representative documentation of their applicability in electrochemical and electroanalytical measurements.
560 citations
TL;DR: Early treatment with glatiramer acetate is efficacious in delaying conversion to clinically definite multiple sclerosis in patients presenting with clinically isolated syndrome and brain lesions detected by MRI.
534 citations
National Institutes of Health1, Kean University2, Murdoch University3, Agricultural Research Service4, University of Graz5, Hirosaki University6, Mae Fah Luang University7, Biotec8, University of North Carolina at Chapel Hill9, Uppsala University10, Masaryk University11, DePaul University12, Oregon State University13, Illinois Natural History Survey14, University of Illinois at Chicago15, University of Chicago16, University of Minnesota17, Universidade Nova de Lisboa18, Prince of Songkla University19, University of Hong Kong20, Blaise Pascal University21, University of Illinois at Urbana–Champaign22, Technical University of Madrid23, Tuscia University24, Tottori University25, University of Pretoria26, Stellenbosch University27
TL;DR: A genomic comparison of 6 dothideomycete genomes with other fungi finds a high level of unique protein associated with the class, supporting its delineation as a separate taxon.
TL;DR: Dietary components including long chain ω-3 fatty acids, antioxidant vitamins, plant flavonoids, prebiotics and probiotics have the potential to modulate predisposition to chronic inflammatory conditions and may have a role in their therapy.
Abstract: Inflammation is a stereotypical physiological response to infections and tissue injury; it initiates pathogen killing as well as tissue repair processes and helps to restore homeostasis at infected or damaged sites. Acute inflammatory reactions are usually self-limiting and resolve rapidly, due to the involvement of negative feedback mechanisms. Thus, regulated inflammatory responses are essential to remain healthy and maintain homeostasis. However, inflammatory responses that fail to regulate themselves can become chronic and contribute to the perpetuation and progression of disease. Characteristics typical of chronic inflammatory responses underlying the pathophysiology of several disorders include loss of barrier function, responsiveness to a normally benign stimulus, infiltration of inflammatory cells into compartments where they are not normally found in such high numbers, and overproduction of oxidants, cytokines, chemokines, eicosanoids and matrix metalloproteinases. The levels of these mediators amplify the inflammatory response, are destructive and contribute to the clinical symptoms. Various dietary components including long chain omega-3 fatty acids, antioxidant vitamins, plant flavonoids, prebiotics and probiotics have the potential to modulate predisposition to chronic inflammatory conditions and may have a role in their therapy. These components act through a variety of mechanisms including decreasing inflammatory mediator production through effects on cell signaling and gene expression (omega-3 fatty acids, vitamin E, plant flavonoids), reducing the production of damaging oxidants (vitamin E and other antioxidants), and promoting gut barrier function and anti-inflammatory responses (prebiotics and probiotics). However, in general really strong evidence of benefit to human health through anti-inflammatory actions is lacking for most of these dietary components. Thus, further studies addressing efficacy in humans linked to studies providing greater understanding of the mechanisms of action involved are required.
TL;DR: The structure, function, and regulation of lipolytic enzymes with a special emphasis on ATGL are focused on, which create the "lipolysome," a complex metabolic network that contributes to the control of lipid and energy homeostasis.
TL;DR: In this review, more than 220 published examples of microwave-assisted synthetic organic transformations from the 2004 to 2008 literature are discussed and more than 500 reaction schemes are presented in the Electronic Supplementary Material.
Abstract: Direct and rapid heating by microwave irradiation in combination with sealed vessel processing in many cases enables reactions to be carried out in a fraction of the time generally required using conventional conditions. This makes microwave chemistry an ideal tool for rapid reaction scouting and optimization of conditions, allowing very rapid progress through hypotheses–experiment–results iterations. The speed at which multiple variations of reaction conditions can be performed allows a morning discussion of “What should we try?” to become an after-lunch discussion of “What were the results” Not surprisingly, therefore, many scientists both in academia and industry have turned to microwave synthesis as a front-line methodology for their projects. In this review, more than 220 published examples of microwave-assisted synthetic organic transformations from the 2004 to 2008 literature are discussed. An additional ca. 500 reaction schemes are presented in the Electronic Supplementary Material, providing the reader with an overall number of ca. 930 references in this fast-moving and exciting field.
TL;DR: The findings suggest that EEG alpha band synchronisation during creative thinking can be interpreted as a sign of active cognitive processes rather than cortical idling.
Abstract: Cortical activity in the EEG alpha band has proven to be particularly sensitive to creativity-related demands, but its functional meaning in the context of creative cognition has not been clarified yet Specifically, increases in alpha activity (ie, alpha synchronisation) in response to creative thinking can be interpreted in different ways: As a functional correlate of cortical idling, as a sign of internal top-down activity or, more specifically, as selective inhibition of brain regions We measured brain activity during creative thinking in two studies employing different neurophysiological measurement methods (EEG and fMRI) In both studies, participants worked on four verbal tasks differentially drawing on creative idea generation The EEG study revealed that the generation of original ideas was associated with alpha synchronisation in frontal brain regions and with a diffuse and widespread pattern of alpha synchronisation over parietal cortical regions The fMRI study revealed that task performance was associated with strong activation in frontal regions of the left hemisphere In addition, we found task-specific effects in parietotemporal brain areas The findings suggest that EEG alpha band synchronisation during creative thinking can be interpreted as a sign of active cognitive processes rather than cortical idling
TL;DR: Stable peptide inhibitors are designed that specifically disrupt proinflammatory CCL5-CXCL4 interactions, thereby attenuating monocyte recruitment and reducing atherosclerosis without the aforementioned side effects.
Abstract: Atherosclerosis is characterized by chronic inflammation of the arterial wall due to chemokine-driven mononuclear cell recruitment. Activated platelets can synergize with chemokines to exacerbate atherogenesis; for example, by deposition of the chemokines platelet factor-4 (PF4, also known as CXCL4) and RANTES (CCL5), triggering monocyte arrest on inflamed endothelium. Homo-oligomerization is required for the recruitment functions of CCL5, and chemokine heteromerization has more recently emerged as an additional regulatory mechanism, as evidenced by a mutual modulation of CXCL8 and CXCL4 activities and by enhanced monocyte arrest resulting from CCL5-CXCL4 interactions. The CCL5 antagonist Met-RANTES reduces diet-induced atherosclerosis; however, CCL5 antagonism may not be therapeutically feasible, as suggested by studies using Ccl5-deficient mice which imply that direct CCL5 blockade would severely compromise systemic immune responses, delay macrophage-mediated viral clearance and impair normal T cell functions. Here we determined structural features of CCL5-CXCL4 heteromers and designed stable peptide inhibitors that specifically disrupt proinflammatory CCL5-CXCL4 interactions, thereby attenuating monocyte recruitment and reducing atherosclerosis without the aforementioned side effects. These results establish the in vivo relevance of chemokine heteromers and show the potential of targeting heteromer formation to achieve therapeutic effects.
TL;DR: This study provides first evidence of differential brain activation to visual food stimuli in patients suffering from BED and bulimia nervosa, and displays greater arousal, ACC activation, and insula activation than the other groups.
TL;DR: It is believed that vitamin D supplementation should be prescribed to patients with hypertension and 25-hydroxyvitamin D levels below target values, in view of the relatively safe and inexpensive way in which vitamin D can be supplemented.
Abstract: Vitamin D deficiency is common and is primarily caused by a lack of ultraviolet-B (UVB) radiation from reduced sun exposure, and the consequent limiting of vitamin D production in the skin. The vitamin D endocrine system regulates about 3% of the human genome. Observational data support the concept that vitamin D is involved in the pathogenesis of cardiovascular diseases and arterial hypertension. The antihypertensive properties of vitamin D include renoprotective effects, suppression of the renin-angiotensin-aldosterone system, direct effects on vascular cells, and effects on calcium metabolism, including prevention of secondary hyperparathyroidism. The results of clinical studies largely, but not consistently, favor the hypothesis that vitamin D sufficiency promotes lowering of arterial blood pressure. Randomized, placebo-controlled trials are greatly needed to clarify and definitively prove the effect of vitamin D on blood pressure. In general, the antihypertensive effects of vitamin D seem to be particularly prominent in vitamin-D-deficient patients with elevated blood pressure. Thus, in view of the relatively safe and inexpensive way in which vitamin D can be supplemented, we believe that vitamin D supplementation should be prescribed to patients with hypertension and 25-hydroxyvitamin D levels below target values.
TL;DR: It is demonstrated that visual BCI feedback clearly modulates sensorimotor EEG rhythms, and the presentation form (abstract versus realistic) does not influence the performance in a BCI, at least in initial training sessions.
TL;DR: These data directly link the left angular gyrus with arithmetic fact retrieval and show that strategy self-reports can be used to predict differential patterns of brain activation.
TL;DR: The present article highlights recent advances and current status in the characterization and the utilization of nanostructured aqueous dispersions in which the submicron-sized dispersed particles envelope a distinctive well-defined self-assembled interior.
TL;DR: In this article, a prospective study was conducted in a group of 640 healthy pediatric patients (age range, 1 day to 18 years; body surface area range, 0.12-2.25 m 2 ).
Abstract: Background Tricuspid annular plane systolic excursion (TAPSE) is an echocardiographic measurement to assess right ventricular systolic function in adults. The aim of this study was to determine growth-related changes in TAPSE to establish references values. Methods A prospective study was conducted in a group of 640 healthy pediatric patients (age range, 1 day to 18 years; body surface area range, 0.12-2.25 m 2 ). The effects of age and body surface area on TAPSE were determined. Results TAPSE ranged from a mean of 0.91 cm ( z score ± 3, 0.56-1.26 cm) in neonates to 2.47 cm ( z score ± 3, 1.84-3.10 cm) in 18-year-olds. TAPSE values showed positive correlations with age and body surface area. There was no significant difference in TAPSE values between female or male children. Conclusion In this study, z scores of TAPSE values were calculated and percentile charts were established to serve as reference data for ready application in patients with congenital heart disease in the future.
TL;DR: In this paper, the properties of ghost and gluon propagators in the deep infrared momentum region of Landau gauge Yang-Mills theory were discussed. And it was shown that it is only a matter of infrared boundary conditions whether infrared scaling or decoupling occurs.
TL;DR: The available data imply that the measurement of sTNF‐Rs, especially of the sT NF‐R 75kD type, is a useful adjunct for quantification of the Th1‐type immune response, similar to other immune activation markers such as neopterin and β2‐microglobulin.
Abstract: Soluble tumour necrosis factor receptors (sTNF-Rs) play a role as modulators of the biological function of tumour necrosis factor-α (TNF-α) in an agonist/antagonist pattern. In various pathologic states the production and release of sTNF-Rs may mediate host response and determine the course and outcome of disease by interacting with TNF-α and competing with cell surface receptors. The determination of sTNF-Rs in body fluids such as plasma or serum is a new tool to gain information about immune processes and provides valuable insight into a variety of pathological conditions. Regarding its immediate clinical use, sTNF-Rs levels show high accuracy in the follow-up and prognosis of various diseases. In HIV infection and sepsis, sTNF-Rs concentrations strongly correlate with the clinical stage and the progression of disease and can be of predictive value. Determination of sTNF-Rs also gives useful information for monitoring cancer and autoimmune diseases. The information provided is often even superior to that obtained with classical disease markers, probably due to the direct involvement of the “TNF system” in the pathogenetic mechanisms in these patients. The available data imply that the measurement of sTNF-Rs, especially of the sTNF-R 75kD type, is a useful adjunct for quantification of the Th1-type immune response, similar to other immune activation markers such as neopterin and β2-microglobulin. Endogenous sTNF-Rs concentrations appear to reflect the activation state of the TNF-α/TNF receptor system.
TL;DR: Two cytosolic key regions within STIM1 C terminus are identified that control ORAI1/CRAC activation: a homomerization domain indispensable for coupling to ORAi1 and a modulatory domain that controls the extent of coupling to SOTA1.
TL;DR: It is demonstrated that low 25(OH)D levels are associated with features of the metabolic syndrome in PCOS women and large intervention trials are warranted to evaluate the effect of vitamin D supplementation on metabolic disturbances in PCos women.
Abstract: Objectives: Women with polycystic ovary syndrome (PCOS) frequently suffer from metabolic disturbances, in particular from insulin resistance. Accumulating evidence suggests that vitamin D deficiency may contribute to the development of metabolic syndrome (MS). Hence, the aim of our study was to investigate the association of 25(OH)D levels and the components of the MS in PCOS women. Methods: 25(OH)D levels were measured by means of ELISA in 206 women affected by PCOS. Metabolic, endocrine, and anthropometric measurements and oral glucose tolerance tests were performed. Results: The prevalence of insufficient 25(OH)D levels (!30 ng/ml) was 72.8% in women with PCOS. PCOS women with MS had lower 25(OH)D levels than PCOS women without these features (17.3 vs 25.8 ng/ml respectively; P!0.05). In multivariate regression analysis including 25(OH)D, season, body mass index (BMI), and age, 25(OH)D and BMI were independent predictors of homeostatic model assessment-insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI; P!0.05 for all). In binary logistic regression analyses, 25(OH)D (odds ratio, OR 0.86, PZ0.019) and BMI (OR 1.28, P!0.001) were independent predictors of MS in PCOS women. We found significantly negative correlations of 25(OH)D levels with BMI, waist circumference, waist-to-hip ratio, systolic and diastolic blood pressure, fasting and stimulated glucose, area under the glucose response curve, fasting insulin, HOMA-IR, HOMA-b, triglycerides, and quotient total cholesterol/high-density lipoprotein (HDL) and positive correlations of 25(OH)D levels with QUICKI and HDL (P!0.05 for all). Conclusion: We demonstrate that low 25(OH)D levels are associated with features of MS in PCOS women. Large intervention trials are warranted to evaluate the effect of vitamin D supplementation on metabolic disturbances in PCOS women.
TL;DR: The results indicate that bacteria can form highly structured, biofilm-like assemblages on fungal surfaces and reach considerable abundances of up to 108 cells per gram fresh weight in alpine environments.
Abstract: Lichens are generally considered as mutualisms between fungi and green algae or cyanobacteria. These partnerships allow light-exposed and long-living joint structures. The unique organization of lichens provides still unexplored environments for microbial communities. To study lichen-associated bacterial communities, we analyze samples, by a polyphasic approach, from three lichen species (Cladonia arbuscula, Lecanora polytropa and Umbilicaria cylindrica) from alpine environments. Our results indicate that bacteria can form highly structured, biofilm-like assemblages on fungal surfaces and reach considerable abundances of up to 108 cells per gram fresh weight. Fluorescence in situ hybridization reveals the predominance of Alphaproteobacteria. Microbial fingerprints performed by PCR-single-strand conformation polymorphism analysis using universal and group-specific primers show distinct patterns for each lichen species. Characterization of cultivable strains and presence of functional genes in the total fraction suggest the involvement of associated bacteria in nutrient cycling. Ubiquitous nifH genes, which encode the nitrogenase reductase, show a high diversity and are assigned to Alphaproteobacteria and Firmicutes, for example, Paenibacillus. Cultivable strains mainly belonging to the genera Acinetobacter, Bacillus, Burkholderia, Methylobacterium and Paenibacillus show lytic (chitinolytic, glucanolytic, and proteolytic) activities, hormone production (indole-3-acetic acid) as well as phosphate mobilization and antagonistic activity toward other microorganisms. The traditional concept of lichens has to be expanded to consider multiple bacterial partners.
TL;DR: An overview of the state of the art of recent research activities in noncoherent ultra-wideband receiver front ends is provided with a focus on architectures that perform the initial signal processing tasks in the analog domain, such that the receiver does not need to sample the UWB received signals at Nyquist rate.
Abstract: The need for low-complexity devices with low-power consumption motivates the application of suboptimal noncoherent ultra-wideband (UWB) receivers. This article provides an overview of the state of the art of recent research activities in this field. It introduces energy detection and autocorrelation receiver front ends with a focus on architectures that perform the initial signal processing tasks in the analog domain, such that the receiver does not need to sample the UWB received signals at Nyquist rate. Common signaling and multiple access schemes are reviewed for both front ends. An elaborate section illustrates various performance tradeoffs to highlight preferred system choices. Practical issues are discussed, including, for low-data-rate schemes, the allowed power allocation per pulse according to the regulator's ruling and the estimated power consumption of a receiver chip. A large part is devoted to signal processing steps needed in a digital receiver. It starts with synchronization and time-of-arrival estimation schemes, introduces studies about the narrowband interference problem, and describes solutions for high-data-rate and multiple access communications. Drastic advantages concerning complexity and robustness justify the application of noncoherent UWB systems, particularly for low-data-rate systems.
TL;DR: This Minireview highlights recent applications of the mechanistically unprecedented transition-metal-catalyzed cross-coupling reaction in modern organic synthesis, with an emphasis on cases in which traditional methods for C-C bond formation have failed.
Abstract: Although a plethora of highly selective and reliable methods for the construction of C-C bonds are known to organic chemists, there is growing interest in the development of new protocols that offer different or orthogonal reactivity to that of existing methods. In 2000, Liebeskind and Srogl described a mechanistically unprecedented transition-metal-catalyzed cross-coupling of thioesters with boronic acids to produce ketones under neutral conditions. This desulfitative cross-coupling process is catalytic in palladium(0), stoichiometric in copper(I), and applicable to a range of organosulfur derivatives and nucleophilic organometallic reagents. In this Minireview, we highlight recent applications of this intriguing cross-coupling reaction in modern organic synthesis, with an emphasis on cases in which traditional methods for C-C bond formation have failed.
TL;DR: During improvisation dance, professional dancers exhibited more right-hemispheric alpha synchronization than the group of novices did, while during imagining dancing the waltz no significant group differences emerged.