Showing papers by "University of Jena published in 2007"

The Chlamydomonas Genome Reveals the Evolution of Key Animal and Plant Functions

Abstract: Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the approximately 120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella.

Plant oil renewable resources as green alternatives in polymer science

Abstract: The utilization of plant oil renewable resources as raw materials for monomers and polymers is discussed and reviewed. In an age of increasing oil prices, global warming and other environmental problems (e.g. waste) the change from fossil feedstock to renewable resources can considerably contribute to a sustainable development in the future. Especially plant derived fats and oils bear a large potential for the substitution of currently used petrochemicals, since monomers, fine chemicals and polymers can be derived from these resources in a straightforward fashion. The synthesis of monomers as well as polymers from plant fats and oils has already found some industrial application and recent developments in this field offer promising new opportunities, as is shown within this contribution. (138 references.)

Normative data for the "Sniffin' Sticks" including tests of odor identification, odor discrimination, and olfactory thresholds: an upgrade based on a group of more than 3,000 subjects.

Abstract: "Sniffin' Sticks" is a test of nasal chemosensory function that is based on pen-like odor dispensing devices, introduced some 10 years ago by Kobal and co-workers. It consists of tests for odor threshold, discrimination, and identification. Previous work established its test-retest reliability and validity. Results of the test are presented as "TDI score", the sum of results obtained for threshold, discrimination, and identification measures. While normative data have been established they are based on a relatively small number of subjects, especially with regard to subjects older than 55 years where data from only 30 healthy subjects have been used. The present study aimed to remedy this situation. Now data are available from 3,282 subjects as compared to data from 738 subjects published previously. Disregarding sex-related differences, the TDI score at the tenth percentile was 24.9 in subjects younger than 15 years, 30.3 for ages from 16 to 35 years, 27.3 for ages from 36 to 55 years, and 19.6 for subjects older than 55 years. Because the tenth percentile has been defined to separate hyposmia from normosmia, these data can be used as a guide to estimate individual olfactory ability in relation to subject's age. Absolute hyposmia was defined as the tenth percentile score of 16-35 year old subjects. Other than previous reports the present norms are also sex-differentiated with women outperforming men in the three olfactory tests. Further, the present data suggest specific changes of individual olfactory functions in relation to age, with odor thresholds declining most dramatically compared to odor discrimination and odor identification.

Self‐Healing Materials

Abstract: Self-healing materials are able to partially or completely heal damage inflicted on them, e.g., crack formation; it is anticipated that the original functionality can be restored. This article covers the design and generic principles of self-healing materials through a wide range of different material classes including metals, ceramics, concrete, and polymers. Recent key developments and future challenges in the field of self-healing materials are summarised, and generic, fundamental material-independent principles and mechanism are discussed and evaluated.

Nuclear Activity of MLA Immune Receptors Links Isolate-Specific and Basal Disease-Resistance Responses

Abstract: Plant immune responses are triggered by pattern recognition receptors that detect conserved pathogen-associated molecular patterns (PAMPs) or by resistance (R) proteins recognizing isolate-specific pathogen effectors. We show that in barley, intracellular mildew A (MLA) R proteins function in the nucleus to confer resistance against the powdery mildew fungus. Recognition of the fungal avirulence A10 effector by MLA10 induces nuclear associations between receptor and WRKY transcription factors. The identified WRKY proteins act as repressors of PAMP-triggered basal defense. MLA appears to interfere with the WRKY repressor function, thereby de-repressing PAMP-triggered basal defense. Our findings reveal a mechanism by which these polymorphic immune receptors integrate distinct pathogen signals.

Epidemiology of sepsis in Germany: results from a national prospective multicenter study

Abstract: To determine the prevalence and mortality of ICU patients with severe sepsis in Germany, with consideration of hospital size. Prospective, observational, cross-sectional 1-day point-prevalence study. 454 ICUs from a representative nationwide sample of 310 hospitals stratified by size. Data were collected via 1-day on-site audits by trained external study physicians. Visits were randomly distributed over 1 year (2003). Inflammatory response of all ICU patients was assessed using the ACCP/SCCM consensus conference criteria. Patients with severe sepsis were followed up after 3 months for hospital mortality and length of ICU stay. Main outcome measures were prevalence and mortality. A total of 3,877 patients were screened. Prevalence was 12.4% (95% CI, 10.9–13.8%) for sepsis and 11.0% (95% CI, 9.7–12.2%) for severe sepsis including septic shock. The ICU and hospital mortality of patients with severe sepsis was 48.4 and 55.2%, respectively, without significant differences between hospital size. Prevalence and mean length of ICU stay of patients with severe sepsis were significantly higher in larger hospitals and universities (≤ 200 beds: 6% and 11.5 days, universities: 19% and 19.2 days, respectively). The expected number of newly diagnosed cases with severe sepsis in Germany amounts to 76–110 per 100,000 adult inhabitants. To allow better comparison between countries, future epidemiological studies should use standardized study methodologies with respect to sepsis definitions, hospital size, and daily and monthly variability.

Genomics-driven discovery of PKS-NRPS hybrid metabolites from Aspergillus nidulans

Abstract: In the postgenomic era it has become increasingly apparent that the vast number of predicted biosynthesis genes of microorganisms is not reflected by the metabolic profile observed under standard fermentation conditions. In the absence of a particular (in most cases unknown) trigger these gene loci remain silent. Because these cryptic gene clusters may code for the biosynthesis of important virulence factors, toxins, or even drug candidates, new strategies for their activation are urgently needed to make use of this largely untapped reservoir of potentially bioactive compounds. The discovery of new microbial metabolites through genome mining has proven to be a very promising approach. Even so, the investigation of silent gene clusters is still a substantial challenge, particularly in fungi. Here we report a new strategy for the successful induction of a silent metabolic pathway in the important model organism Aspergillus nidulans, which led to the discovery of novel PKS-NRPS hybrid metabolites.

A pivotal role for galectin-1 in fetomaternal tolerance

Abstract: A successful pregnancy requires synchronized adaptation of maternal immune-endocrine mechanisms to the fetus. Here we show that galectin-1 (Gal-1), an immunoregulatory glycan-binding protein, has a pivotal role in conferring fetomaternal tolerance. Consistently with a marked decrease in Gal-1 expression during failing pregnancies, Gal-1–deficient (Lgals1−/−) mice showed higher rates of fetal loss compared to wild-type mice in allogeneic matings, whereas fetal survival was unaffected in syngeneic matings. Treatment with recombinant Gal-1 prevented fetal loss and restored tolerance through multiple mechanisms, including the induction of tolerogenic dendritic cells, which in turn promoted the expansion of interleukin-10 (IL-10)–secreting regulatory T cells in vivo. Accordingly, Gal-1's protective effects were abrogated in mice depleted of regulatory T cells or deficient in IL-10. In addition, we provide evidence for synergy between Gal-1 and progesterone in the maintenance of pregnancy. Thus, Gal-1 is a pivotal regulator of fetomaternal tolerance that has potential therapeutic implications in threatened pregnancies.

Invitation to data reduction and problem kernelization

Abstract: To solve NP-hard problems, polynomial-time preprocessing is a natural and promising approach. Preprocessing is based on data reduction techniques that take a problem's input instance and try to perform a reduction to a smaller, equivalent problem kernel. Problem kernelization is a methodology that is rooted in parameterized computational complexity. In this brief survey, we present data reduction and problem kernelization as a promising research field for algorithm and complexity theory.

Maximum kick from nonspinning black-hole binary inspiral.

Abstract: When unequal-mass black holes merge, the final black hole receives a kick due to the asymmetric loss of linear momentum in the gravitational radiation emitted during the merger. The magnitude of this kick has important astrophysical consequences. Recent breakthroughs in numerical relativity allow us to perform the largest parameter study undertaken to date in numerical simulations of binary black-hole inspirals. We study nonspinning black-hole binaries with mass ratios from q=M1/M2=1 to q=0.25 (η=q/(1+q)2 from 0.25 to 0.16). We accurately calculate the velocity of the kick to within 6%, and the final spin of the black holes to within 2%. A maximum kick of 175.2±11 km s-1 is achieved for η=0.195±0.005.

Microbes and metals: interactions in the environment.

Abstract: Research on the behaviour of microorganisms in geogenic or anthropogenic metallomorphic environments is an integral part of geomicrobiology. The investigation of microbial impact on the fate of minerals and geologically significant compounds of mining areas can lead to an understanding of biogeochemical cycles. Metabolic processes of microorganisms are the cause for the dissolution of minerals, and especially pyrite oxidation results in the generation of acid mine drainage which, in turn, leads to heavy metal contamination as a result of mining activities. On the other hand, microbial metabolism can also contribute to the formation of certain ore deposits over geological time. The adaptation to heavy metal rich environments is resulting in microorgansims which show activities for biosorption, bioprecipitation, extracellular sequestration, transport mechanisms, and/or chelation. Such resistance mechanisms are the basis for the use of microorganisms in bioremediation approaches. As only a small part of the worldwide occurring prokaryotes has been described yet, the understanding of the role bacteria play in a geogenic and pedogenic context is very likely to change deeply as soon as more habitat relevant microbial functions can be described. Examples for the identification of microbial processes from case studies may help to advance this field. The strongly interdisciplinary field of bio-geo-interactions spanning from the microorganism to the mineral holds much promise for future developments in both basic research as well as applied sciences. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Superordinate identities and intergroup conflict: The ingroup projection model

Abstract: This chapter summarises results from a research programme on the psychological basis of tolerance and discrimination in intergroup relations, with particular consideration of the role of superordinate identities. According to the ingroup projection model, a relevant superordinate group provides dimensions and norms for comparisons between ingroup and outgroup. Groups gain positive value or status when they are considered prototypical for the (positively valued) superordinate group. Group members tend to generalise (project) distinct ingroup characteristics onto the superordinate category, implying the relative prototypicality of their ingroup. To the extent that outgroup difference is regarded as a deviation from the ethnocentrically construed prototype it is evaluated negatively. Our research studied consequences and determinants of ingroup projection, as well as moderators of its implications. The findings contribute to a deeper understanding of the processes involved in intergroup discrimination and in...

The fast-slow continuum in mammalian life history: An empirical reevaluation

Abstract: Many life‐history traits co‐vary across species, even when body size differences are controlled for. This phenomenon has led to the concept of a “fast‐slow continuum,” which has been influential in both empirical and theoretical studies of life‐history evolution. We present a comparative analysis of mammalian life histories showing that, for mammals at least, there is not a single fast‐slow continuum. Rather, both across and within mammalian clades, the speed of life varies along at least two largely independent axes when body size effects are removed. One axis reflects how species balance offspring size against offspring number, while the other describes the timing of reproductive bouts.

Entrepreneurship and its Determinants in a Cross-Country Setting

Abstract: The relative stability of differences in entrepreneurial activity across countries suggests that other than economic factors are at play. The present paper offers some new thoughts about the determinants of entrepreneurial attitudes and activities by testing the relationship between institutional variables and cross-country differences in the preferences for self-employment as well as in actual self-employment. Data of the 25 member states of the European Union as well as the US are used. The results show that country specific (cultural) variables seem to explain the preference for entrepreneurship, but cannot explain actual entrepreneurship. The present paper also introduces the remaining four papers of the special issue of the Journal of Evolutionary Economics, which center around the theme Entrepreneurship and Culture.

Multiple emulsions for food use

Abstract: Numerous investigations were done to describe the effects of different food-grade components (e.g. lipid phases, emulsifiers, electrolytes, biopolymers, sugars) on the stability of multiple emulsions (type W/O/W and O/W/O). In addition to the emulsion composition, the stability of such systems also depends heavily on the emulsion matrix, influenced by the dispersing methods used. This review highlights recently published results of research done in the preparation of such dispersed systems and in the manipulation of their emulsion stability as well as encapsulation behaviour.

Deletion of Complement Factor H–Related Genes CFHR1 and CFHR3 Is Associated with Atypical Hemolytic Uremic Syndrome

Abstract: Atypical hemolytic uremic syndrome (aHUS) is associated with defective complement regulation. Disease-associated mutations have been described in the genes encoding the complement regulators complement factor H, membrane cofactor protein, factor B, and factor I. In this study, we show in two independent cohorts of aHUS patients that deletion of two closely related genes, complement factor H–related 1 (CFHR1) and complement factor H–related 3 (CFHR3), increases the risk of aHUS. Amplification analysis and sequencing of genomic DNA of three affected individuals revealed a chromosomal deletion of ∼84 kb in the RCA gene cluster, resulting in loss of the genes coding for CFHR1 and CFHR3, but leaving the genomic structure of factor H intact. The CFHR1 and CFHR3 genes are flanked by long homologous repeats with long interspersed nuclear elements (retrotransposons) and we suggest that nonallelic homologous recombination between these repeats results in the loss of the two genes. Impaired protection of erythrocytes from complement activation is observed in the serum of aHUS patients deficient in CFHR1 and CFHR3, thus suggesting a regulatory role for CFHR1 and CFHR3 in complement activation. The identification of CFHR1/CFHR3 deficiency in aHUS patients may lead to the design of new diagnostic approaches, such as enhanced testing for these genes.

Diagnostic criteria for hematopoietic stem cell transplant-associated microangiopathy : results of a consensus process by an International Working Group

Abstract: Background and Objectives There are no widely accepted criteria for the definition of hematopoietic stem cell transplant-associated microangiopathy (TAM). An International Working Group was formed to develop a consensus formulation of criteria for diagnosing clinically significant TAM.Design and Methods The participants proposed a list of candidate criteria, selected those considered necessary, and ranked those considered optional to identify a core set of criteria. Three obligatory criteria and four optional criteria that ranked highest formed a core set. In an appropriateness panel process, the participants scored the diagnosis of 16 patient profiles as appropriate or not appropriate for TAM. Using the experts’ ratings on the patient profiles as a gold standard, the sensitivity and specificity of 24 candidate definitions of the disorder developed from the core set of criteria were evaluated. A nominal group technique was used to facilitate consensus formation. The definition of TAM with the highest score formed the final proposal.Results The Working Group proposes that the diagnosis of TAM requires fulfilment of all of the following criteria: (i) >4% schistocytes in blood; (ii) de novo, prolonged or progressive thrombocytopenia (platelet count

Inspiral, merger, and ringdown of unequal mass black hole binaries: A multipolar analysis

Abstract: We study the inspiral, merger, and ringdown of unequal mass black hole binaries by analyzing a catalogue of numerical simulations for seven different values of the mass ratio (from q=M2/M1=1 to q=4). We compare numerical and post-Newtonian results by projecting the waveforms onto spin-weighted spherical harmonics, characterized by angular indices (l,m). We find that the post-Newtonian equations predict remarkably well the relation between the wave amplitude and the orbital frequency for each (l,m), and that the convergence of the post-Newtonian series to the numerical results is nonmonotonic. To leading order, the total energy emitted in the merger phase scales like η2 and the spin of the final black hole scales like η, where η=q/(1+q)2 is the symmetric mass ratio. We study the multipolar distribution of the radiation, finding that odd-l multipoles are suppressed in the equal mass limit. Higher multipoles carry a larger fraction of the total energy as q increases. We introduce and compare three different definitions for the ringdown starting time. Applying linear-estimation methods (the so-called Prony methods) to the ringdown phase, we find resolution-dependent time variations in the fitted parameters of the final black hole. By cross correlating information from different multipoles, we show that ringdown fits can be used to obtain precise estimates of the mass and spin of the final black hole, which are in remarkable agreement with energy and angular momentum balance calculations.

Quality of life and psychological well being in polycystic ovary syndrome

Abstract: BACKGROUND: Polycystic ovary syndrome (PCOS) is associated with poor quality of life (QoL) and high levels of depression. Existing research is confounded by small sample sizes and inconsistent use of control groups. METHODS: Depression and QoL were assessed in women with PCOS and healthy controls (n 5 1359). The polycystic ovary syndrome health-related QoL questionnaire (PCOSQ) was modified to include an acne subscale. RESULTS: Seventy-one percentage of women with PCOS who were taking anti-androgen (AA) medication and 67% not taking AA medication were classified as depressed. Women with PCOS had lower QoL on all seven factors of the modified PCOSQ (emotional disturbance, weight, infertility, acne, menstrual symptoms, menstrual predictability and hirsutism). Weight was the largest contributor to poor QoL for women taking and not taking AA medication. Women taking AA medication, independent of diagnosis, generally had better QoL than women not taking them. CONCLUSIONS: This large study refines our understanding of depression and QoL in PCOS and demonstrates the need to regularly review the psychological health of women with PCOS.

Effect of rivastigmine on delay to diagnosis of Alzheimer's disease from mild cognitive impairment: the InDDEx study.

Abstract: Summary Objective To assess the effect of rivastigmine in patients with mild cognitive impairment (MCI) on the time to clinical diagnosis of Alzheimer's disease (AD) and the rate of cognitive decline. Methods The study was a double-blind, randomised, placebo-controlled trial of up to 48 months. All patients had MCI operationally defined by having cognitive symptoms, a global clinical dementia rating stage of 0·5, a score of less than 9 on the New York University delayed paragraph recall test, and by not meeting the diagnostic criteria for AD. Primary efficacy variables were time to clinical diagnosis of AD, and change in performance on a cognitive test battery. This study is registered with the US National Institutes of Health clinical trials database (ClinicalTrials.gov), number NCT00000174. Findings Of 1018 study patients enrolled, 508 were randomly assigned to rivastigmine and 510 to placebo; 17·3% of patients on rivastigmine and 21·4% on placebo progressed to AD (hazard ratio 0·85 [95% CI 0·64–1·12]; p=0·225). There was no significant difference between the rivastigmine and placebo groups on the standardised Z score for the cognitive test battery measured as mean change from baseline to endpoint (−0·10 [95% CI −0·63 to 0·44], p=0·726). Serious adverse events were reported by 141 (27·9%) rivastigmine-treated patients and 155 (30·5%) patients on placebo; adverse events of all types were reported by 483 (95·6%) rivastigmine-treated patients and 472 (92·7%) placebo-treated patients. The predominant adverse events were cholinergic: the frequencies of nausea, vomiting, diarrhoea, and dizziness were two to four times higher in the rivastigmine group than in the placebo group. Interpretation There was no significant benefit of rivastigmine on the progression rate to AD or on cognitive function over 4 years. The overall rate of progression from MCI to AD in this randomised clinical trial was much lower than predicted. Rivastigmine treatment was not associated with any significant safety concerns.

Supermassive recoil velocities for binary black-hole mergers with antialigned spins.

Abstract: Recent calculations of the recoil velocity in binary black-hole mergers have found the kick velocity to be of the order of a few hundred km/s in the case of nonspinning binaries and about 500 km/s in the case of spinning configurations, and have lead to predictions of a maximum kick of up to 1300 km/s. We test these predictions and demonstrate that kick velocities of at least 2500 km/s are possible for equal-mass binaries with antialigned spins in the orbital plane. Kicks of that magnitude are likely to have significant repercussions for models of black-hole formation, the population of intergalactic black holes, and the structure of host galaxies.

Creative Class and Regional Growth − Empirical Evidence from Eight European Countries

Abstract: We analyze the regional distribution and the effect of people in creative occupations based on data for more than 450 regions in eight European countries. The geographic distribution of the creative class is highly uneven. The creative class is not attracted to highly urbanized regions per se, but rather a climate of tolerance and openness seem to be rather important factors. We find that the creative class has a positive and significant effect on employment growth and new business formation at the regional level. Human capital as measured by creative occupation outperforms indicators that are based on formal education.

Changes of life satisfaction in the transition to retirement: a latent-class approach.

Abstract: Contradictory positions have been advanced as to whether retirement has negative, positive, or no effects on subjective well-being. The authors investigated changes in life satisfaction in 1,456 German retirees. Using latent growth mixture modeling, the authors found 3 groups of people who experienced retirement differently. In Group 1, satisfaction declined at retirement but continued on a stable or increasing trajectory thereafter. Group 2 demonstrated a large increase in satisfaction at retirement but overall declining satisfaction. In Group 3, satisfaction showed a temporary very small increase at retirement. Groups differed by retirement age, gender, socioeconomic status, marital status, health, unemployment before retiring, and region. Thus, retirement is not a uniform transition, and resource-rich individuals are less likely to experience retirement-related change in satisfaction.