Showing papers by "Humboldt University of Berlin published in 2007"
TL;DR: Pd on Modified Silica 159 4.5.1.
Abstract: 4.4. Pd on Modified Silica 159 4.5. Pd on Clay and Other Inorganic Materials 159 5. Stille, Fukuyama, and Negishi Reactions 159 5.1. Stille Reactions 159 5.1.1. Pd on Carbon (Pd/C) 159 5.1.2. Palladium on KF/Al2O3 159 5.1.3. Pd on Modified Silica (SiO2/TEG/Pd) 159 5.2. Fukuyama Reactions 159 5.2.1. Pd on Carbon (Pd/C) 159 5.2.2. Pd(OH)2 on Carbon (Perlman’s Catalyst) 160 5.3. Pd/C-Catalyzed Negishi Reactions 160 6. Ullmann-Type Coupling Reactions 161 6.1. Pd/C-Catalyzed Aryl−Aryl Coupling 161 6.2. Pd/C-Catalyzed Homocoupling of Vinyl Halides 162
1,900 citations
TL;DR: How environmental factors, infectious microbes, ethnic origin, genetic susceptibility, and a dysregulated immune system can result in mucosal inflammation are discussed.
1,749 citations
TL;DR: The current diagnostic approach, their pathology, natural course, and common complications, the assessment of disease activity, extraintestinal manifestations, and medical and surgical management are discussed, and diagnostic and therapeutic algorithms are provided.
1,677 citations
TL;DR: In this paper, the performance of a free-electron laser operating at a wavelength of 13.7 nm where unprecedented peak and average powers for a coherent extreme-ultraviolet radiation source have been measured.
Abstract: We report results on the performance of a free-electron laser operating at a wavelength of 13.7 nm where unprecedented peak and average powers for a coherent extreme-ultraviolet radiation source have been measured. In the saturation regime, the peak energy approached 170 J for individual pulses, and the average energy per pulse reached 70 J. The pulse duration was in the region of 10 fs, and peak powers of 10 GW were achieved. At a pulse repetition frequency of 700 pulses per second, the average extreme-ultraviolet power reached 20 mW. The output beam also contained a significant contribution from odd harmonics of approximately 0.6% and 0.03% for the 3rd (4.6 nm) and the 5th (2.75 nm) harmonics, respectively. At 2.75 nm the 5th harmonic of the radiation reaches deep into the water window, a wavelength range that is crucially important for the investigation of biological samples.
1,390 citations
TL;DR: It is shown that covalently bound molecular nanostructures can be formed on a gold surface upon thermal activation of porphyrin building blocks and their subsequent chemical reaction at predefined connection points, and it is demonstrated that the topology of these nanostructure can be precisely engineered by controlling the chemical structure of the building blocks.
Abstract: The construction of electronic devices from single molecular building blocks, which possess certain functions such as switching or rectifying and are connected by atomic-scale wires on a supporting surface, is an essential goal of molecular electronics1. A key challenge is the controlled assembly of molecules into desired architectures by strong, that is, covalent, intermolecular connections2, enabling efficient electron transport3 between the molecules and providing high stability4. However, no molecular networks on surfaces ‘locked’ by covalent interactions have been reported so far. Here, we show that such covalently bound molecular nanostructures can be formed on a gold surface upon thermal activation of porphyrin building blocks and their subsequent chemical reaction at predefined connection points. We demonstrate that the topology of these nanostructures can be precisely engineered by controlling the chemical structure of the building blocks. Our results represent a versatile route for future bottom-up construction of sophisticated electronic circuits and devices, based on individual functionalized molecules.
1,177 citations
Duke University1, Johns Hopkins University2, University of Florence3, Leiden University4, Stanford University5, University of Vienna6, University of California, San Francisco7, University of Texas Health Science Center at Houston8, University of Barcelona9, University of Wisconsin-Madison10, University of Zurich11, University of Helsinki12, Yale University13, Mayo Clinic14, University of Turin15, Humboldt University of Berlin16, University of Paris17, St Thomas' Hospital18
TL;DR: These revisions are made to incorporate advances related to tumor cell biology and diagnostic techniques as pertains to mycosis fungoides and Sézary syndrome to clarify certain variables that currently impede effective interinstitution and interinvestigator communication and/or the development of standardized clinical trials in MF and SS.
1,167 citations
TL;DR: In this article, structural and electronic properties and energetic quantities related to the formation of oxygen defects at transition metal (TM) and rare earth (RE) oxide surfaces, neutral oxygen vacancies in particular, play a major role in a variety of technological applications.
1,078 citations
TL;DR: The authors found that subjective, and often biased, perceptions have a crucial impact on new business creation across all countries in their sample and that the strongest cross-national covariate of an individual's entrepreneurial propensity is whether the person believes herself to have the sufficient skills, knowledge, and ability to start a business.
830 citations
Max Planck Society1, Centre national de la recherche scientifique2, Durham University3, North-West University4, Joseph Fourier University5, École Polytechnique6, Heidelberg University7, University of Erlangen-Nuremberg8, University of Hamburg9, University of Tübingen10, Humboldt University of Berlin11, Dublin Institute for Advanced Studies12, Charles University in Prague13, Yerevan Physics Institute14, Ruhr University Bochum15, University of Namibia16
TL;DR: In this paper, the average flux observed during an extreme gamma-ray outburst is I(>200 GeV) = (1.72$\pm$$0.05_{\rm stat}
Abstract: The high-frequency peaked BL Lac PKS 2155-304 at redshift z=0.116 is a well-known VHE (>100 GeV) gamma-ray emitter. Since 2002 its VHE flux has been monitored using the H.E.S.S. stereoscopic array of imaging atmospheric-Cherenkov telescopes in Namibia. During the July 2006 dark period, the average VHE flux was measured to be more than ten times typical values observed from the object. This article focuses solely on an extreme gamma-ray outburst detected in the early hours of July 28, 2006 (MJD 53944). The average flux observed during this outburst is I(>200 GeV) = (1.72$\pm$$0.05_{\rm stat}$$\pm$$0.34_{\rm syst}$) $\times$ 10$^{-9}$ cm$^{-2}$ s$^{-1}$, corresponding to ~7 times the flux, I(>200 GeV), observed from the Crab Nebula. Peak fluxes are measured with one-minute time scale resolution at more than twice this average value. Variability is seen up to ~600 s in the Fourier power spectrum, and well-resolved bursts varying on time scales of ~200 seconds are observed. There are no strong indications for spectral variability within the data. Assuming the emission region has a size comparable to the Schwarzschild radius of a ~10$^9 M_\odot$ black hole, Doppler factors greater than 100 are required to accommodate the observed variability time scales.
788 citations
TL;DR: A comprehensive understanding of phenomena at interfaces with organic materials will improve the rational design of highly functional organic electronic devices.
Abstract: A most appealing feature of the development of (opto)electronic devices based on conjugated organic materials is the highly visible link between fundamental research and technological advances. Improved understanding of organic material properties can often instantly be implemented in novel device architectures, which results in rapid progress in the performance and functionality of devices. An essential ingredient for this success is the strong interdisciplinary nature of the field of organic electronics, which brings together experts in chemistry, physics, and engineering, thus softening or even removing traditional boundaries between the disciplines. Naturally, a thorough comprehension of all properties of organic insulators, semiconductors, and conductors is the goal of current efforts. Furthermore, interfaces between dissimilar materials-organic/organic and organic/inorganic-are inherent in organic electronic devices. It has been recognized that these interfaces are a key for device function and efficiency, and detailed investigations of interface physics and chemistry are at the focus of research. Ultimately, a comprehensive understanding of phenomena at interfaces with organic materials will improve the rational design of highly functional organic electronic devices.
749 citations
University of Texas MD Anderson Cancer Center1, University of Düsseldorf2, Sapienza University of Rome3, University of Bologna4, VU University Medical Center5, Royal Victoria Infirmary6, Mayo Clinic7, City of Hope National Medical Center8, Novartis9, Heidelberg University10, Humboldt University of Berlin11
TL;DR: Nilotinib is highly active and safe in patients with CML-CP after imatinib failure or intolerance and was effective in patients harboring BCR-ABL mutations associated with imatinIB resistance (except T315I), and also in Patients with a resistance mechanism independent of B CR-ABl mutations.
TL;DR: The MAGIC telescope was used to observe the blazar Markarian 501 (Mrk 501) at energies above 100 GeV from May through July 2005 as mentioned in this paper, and the high sensitivity of the instrument enabled the determination of the flux and spectrum of the source on a night-by-night basis.
Abstract: The blazar Markarian 501 (Mrk 501) was observed at energies above 100 GeV with the MAGIC telescope from May through July 2005. The high sensitivity of the instrument enabled the determination of the flux and spectrum of the source on a night-by-night basis. Throughout our observational campaign, the flux from Mrk 501 was found to vary by an order of magnitude, and to be correlated with spectral changes. Intra-night flux variability with flux-doubling times down to 2 minutes was also observed. The strength of variability increased with the energy of the {gamma}-ray photons. The energy spectra were found to harden significantly with increasing flux, and a spectral peak clearly showed up during very active states. The position of the spectral peak seems to be correlated with the source luminosity.
TL;DR: In this article, the authors develop an integrative perspective on catch-and-release (C&R) by drawing on historical, philosophical, socio-psychological, biological, and managerial insights and perspectives.
Abstract: Most research on catch-and-release (C&R) in recreational fishing has been conducted from a disciplinary angle focusing on the biological sciences and the study of hooking mortality after release. This hampers understanding of the complex and multifaceted nature of C&R. In the present synopsis, we develop an integrative perspective on C&R by drawing on historical, philosophical, socio-psychological, biological, and managerial insights and perspectives. Such a perspective is helpful for a variety of reasons, such as 1) improving the science supporting successful fisheries management and conservation, 2) facilitating dialogue between managers, anglers, and other stakeholders, 3) minimizing conflict potentials, and 4) paving the path toward sustainable recreational fisheries management. The present work highlights the array of cultural, institutional, psychological, and biological factors and dimensions involved in C&R. Progress toward successful treatment of C&R might be enhanced by acknowledging the complex...
TL;DR: This work solves a problem of non-convex stochastic optimisation with help of simulated annealing of Levy flights of a variable stability index by solving the problem of search of the ground state of an unknown potential with non-local consequences.
TL;DR: For the various CdTe QD samples, there was no dose-dependent correlation between cell viability and intracellular [Cd2+], implying that their cytotoxicity cannot be attributed solely to the toxic effect of free Cd2+.
Abstract: Several studies suggested that the cytotoxic effects of quantum dots (QDs) may be mediated by cadmium ions (Cd2+) released from the QDs cores. The objective of this work was to assess the intracellular Cd2+ concentration in human breast cancer MCF-7 cells treated with cadmium telluride (CdTe) and core/shell cadmium selenide/zinc sulfide (CdSe/ZnS) nanoparticles capped with mercaptopropionic acid (MPA), cysteamine (Cys), or N-acetylcysteine (NAC) conjugated to cysteamine. The Cd2+ concentration determined by a Cd2+-specific cellular assay was below the assay detection limit (<5 nM) in cells treated with CdSe/ZnS QDs, while in cells incubated with CdTe QDs, it ranged from ∼30 to 150 nM, depending on the capping molecule. A cell viability assay revealed that CdSe/ZnS QDs were nontoxic, whereas the CdTe QDs were cytotoxic. However, for the various CdTe QD samples, there was no dose-dependent correlation between cell viability and intracellular [Cd2+], implying that their cytotoxicity cannot be attributed sole...
TL;DR: High-performance liquid chromatography and gas chromatography-mass spectrometry performed with culture filtrates of FZB42 demonstrated the presence of indole-3-acetic acid (IAA), corroborating it as one of the pivotal plant-growth-promoting substances produced by this bacterium.
Abstract: Phytohormone-like acting compounds previously have been suggested to be involved in the phytostimulatory action exerted by the plant-beneficial rhizobacterium Bacillus amyloliquefaciens FZB42. Analyses by high-performance liquid chromatography and gas chromatography-mass spectrometry performed with culture filtrates of FZB42 demonstrated the presence of indole-3-acetic acid (IAA), corroborating it as one of the pivotal plant-growth-promoting substances produced by this bacterium. In the presence of 5 mM tryptophan, a fivefold increase in IAA secretion was registered. In addition, in the trp auxotrophic strains E101 (ΔtrpBA) and E102 (ΔtrpED), and in two other strains bearing knockout mutations in genes probably involved in IAA metabolism, E103 (ΔysnE, putative IAA transacetylase) and E105 (ΔyhcX, putative nitrilase), the concentration of IAA in the culture filtrates was diminished. Three of these mutant strains were less efficient in promoting plant growth, indicating that the Trp-dependent synthesis of auxins and plant growth promotion are functionally related in B. amyloliquefaciens.
TL;DR: It is shown that the H. pylori CagL protein is a specialized adhesin that is targeted to the pilus surface, where it binds to and activates integrin α5β1 receptor on gastric epithelial cells through an arginine-glycine-aspartate motif.
Abstract: Integrins are important mammalian receptors involved in normal cellular functions as well as pathogenesis of chronic inflammation and cancer. We propose that integrins are exploited by the gastric pathogen and type-1 carcinogen Helicobacter pylori for injection of the bacterial oncoprotein cytotoxin-associated gene A (CagA) into gastric epithelial cells. Virulent H. pylori express a type-IV secretion pilus that injects CagA into the host cell; CagA then becomes tyrosine-phosphorylated by Src family kinases. However, the identity of the host cell receptor involved in this process has remained unknown. Here we show that the H. pylori CagL protein is a specialized adhesin that is targeted to the pilus surface, where it binds to and activates integrin alpha5beta1 receptor on gastric epithelial cells through an arginine-glycine-aspartate motif. This interaction triggers CagA delivery into target cells as well as activation of focal adhesion kinase and Src. Our findings provide insights into the role of integrins in H.-pylori-induced pathogenesis. CagL may be exploited as a new molecular tool for our further understanding of integrin signalling.
TL;DR: Evolutionary impact assessment is a framework for quantifying the effects of harvest-induced evolution on the utility generated by fish stocks.
Abstract: Evolutionary impact assessment is a framework for quantifying the effects of harvest-induced evolution on the utility generated by fish stocks
University of California, San Francisco1, Sahlgrenska University Hospital2, University of Tromsø3, University of Barcelona4, Indiana University – Purdue University Indianapolis5, University of Pisa6, Akdeniz University7, Catholic University of the Sacred Heart8, Medical University of Silesia9, Royal Prince Alfred Hospital10, University of Southern California11, Humboldt University of Berlin12
TL;DR: The incidence of NODAT or IFG at 6 months post‐transplant is significantly lower with CsA‐ME than with tacrolimus without a significant difference in short‐term outcome, and the profile and incidence of adverse events were similar between treatments.
TL;DR: A reproducible anatomical and radiographic point, 1 mm anterior to the anterior cortex extension line, 2.5 mm distal to the posterior origin of the medial femoral condyle, and proximal to the level of the posterior point of the Blumensaat line on a lateral radiograph with both posterior condyles projected in the same plane, shows the mean femoral medial patellofemoral ligament center.
Abstract: BackgroundReconstruction of the medial patellofemoral ligament has recently become popular for restoring patellofemoral stability. Femoral insertion site anatomy of the medial patellofemoral ligament has been described. This anatomical insertion has been inferred to be the isometric point in medial patellofemoral ligament reconstruction, but data about radiographic landmarks for a postoperative or intraoperative control are missing.PurposeTo determine the radiographic landmarks for control of postoperative and intraoperative femoral medial patellofemoral ligament insertion.Study DesignDescriptive laboratory study.MethodsEight fresh-frozen human knees were dissected, and the medial patellofemoral ligament was exposed. After identification of the femoral medial patellofemoral ligament insertion site, the insertion center was marked with a lead ball of 2-mm diameter. Straight lateral radiographs were taken, and posterior-anterior as well as proximal-distal position were evaluated.ResultsSix of 8 insertion po...
TL;DR: In this paper, periodic density functional theory (DFT) calculations for the ground state properties of ground state structures were performed using the Perdew-Burke-Ernzerhof (PBE0) and Heyd-Scuseria-Ernerhof (HSE) hybrid functionals that include nonlocal Fock exchange.
Abstract: We report periodic density functional theory (DFT) calculations for ${\mathrm{CeO}}_{2}$ and ${\mathrm{Ce}}_{2}{\mathrm{O}}_{3}$ using the Perdew-Burke-Ernzerhof (PBE0) and Heyd-Scuseria-Ernzerhof (HSE) hybrid functionals that include nonlocal Fock exchange. We study structural, electronic, and magnetic ground state properties. Hybrid functionals correctly predict ${\mathrm{Ce}}_{2}{\mathrm{O}}_{3}$ to be an insulator as opposed to the ferromagnetic metal predicted by the local spin density (LDA) and generalized gradient (GGA) approximations. The equilibrium volumes of both structures are in very good agreement with experiments, improving upon the description of the LDA and GGA. The calculated ${\mathrm{CeO}}_{2}$ (O $2p$--Ce $5d$) and ${\mathrm{Ce}}_{2}{\mathrm{O}}_{3}$ $(\mathrm{Ce}\phantom{\rule{0.3em}{0ex}}4f\text{\ensuremath{-}}5d4f)$ band gaps are larger by up to 45% (PBE0) and 15% (HSE) than found in experiments. Furthermore, we calculate atomization energies, heats of formation, and the reduction energy of $2{\mathrm{CeO}}_{2}\ensuremath{\rightarrow}{\mathrm{Ce}}_{2}{\mathrm{O}}_{3}+(1∕2){\mathrm{O}}_{2}$. The latter is underestimated by $\ensuremath{\sim}0.4--0.9\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ with respect to available experimental data at room temperature. We compare our results with the more traditional DFT+$U$ (LDA$+U$ and PBE$+U$) approach and discuss the role played by the Hubbard $U$ parameter.
TL;DR: Consistently favorable results in non-HR patients were achieved with significant treatment reduction in the majority of these patients, and compared without previous trial ALL-BFM 90, consistently favorable results were achieved.
TL;DR: A general model of heritable personality differences is proposed that conceptualises intelligence as fitness components and personality traits as individual reaction norms of genotypes across environments, with different fitness consequences in different environmental niches.
Abstract: Genetic influences on personality differences are ubiquitous, but their nature is not well understood. A theoretical framework might help, and can be provided by evolutionary genetics. We assess three evolutionary genetic mechanisms that could explain genetic variance in personality differences: selective neutrality, mutation-selection balance, and balancing selection. Based on evolutionary genetic theory and empirical results from behaviour genetics and personality psychology, we conclude that selective neutrality is largely irrelevant, that mutation-selection balance seems best at explaining genetic variance in intelligence, and that balancing selection by environmental heterogeneity seems best at explaining genetic variance in personality traits. We propose a general model of heritable personality differences that conceptualises intelligence as fitness components and personality traits as individual reaction norms of genotypes across environments, with different fitness consequences in different environmental niches. We also discuss the place of mental health in the model. This evolutionary genetic framework highlights the role of gene-environment interactions in the study of personality, yields new insight into the person-situation-debate and the structure of personality, and has practical implications for both quantitative and molecular genetic studies of personality. Copyright # 2007 John Wiley & Sons, Ltd.
TL;DR: It is proved that, under some complexity theoretic assumption from parameterized complexity theory, HOM(C,−) is in polynomial time if and only if C has bounded tree width modulo homomorphic equivalence.
Abstract: We give a complexity theoretic classification of homomorphism problems for graphs and, more generally, relational structures obtained by restricting the left hand side structure in a homomorphism. For every class C of structures, let HOM(C,−) be the problem of deciding whether a given structure A ∈C has a homomorphism to a given (arbitrary) structure s. We prove that, under some complexity theoretic assumption from parameterized complexity theory, HOM(C,−) is in polynomial time if and only if C has bounded tree width modulo homomorphic equivalence.Translated into the language of constraint satisfaction problems, our result yields a characterization of the tractable structural restrictions of constraint satisfaction problems. Translated into the language of database theory, it implies a characterization of the tractable instances of the evaluation problem for conjunctive queries over relational databases.
TL;DR: It is demonstrated that Akt is not the direct target gene of miR-29 and that the negative effects of mi R-29 on insulin signaling might be mediated by other unknown intermediates, and taken together, these data reveal the crucial role of MiRNAs in type 2 diabetes.
Abstract: Micro-RNAs (miRNAs) have been suggested to play pivotal roles in multifarious diseases associated with the posttranscriptional regulation of protein-coding genes. In this study, we aimed to investigate the function of miRNAs in type 2 diabetes mellitus. The miRNAs expression profiles were examined by miRNA microarray analysis of skeletal muscles from healthy and Goto-Kakizaki rats. We identified four up-regulated miRNAs, and 11 miRNAs that were down-regulated relative to normal individuals. Among induced miRNAs were three paralogs of miR-29, miR-29a, miR-29b, and miR-29c. Northern blotting further confirmed their elevated expression in three important target tissues of insulin action: muscle, fat, and liver of diabetic rats. Adenovirus-mediated overexpression of miR-29a/b/c in 3T3-L1 adipocytes could largely repress insulin-stimulated glucose uptake, presumably through inhibiting Akt activation. The increase in miR-29 level caused insulin resistance, similar to that of incubation with high glucose and insulin in combination, which, in turn, induced miR-29a and miR-29b expression. In this paper, we demonstrate that Akt is not the direct target gene of miR-29 and that the negative effects of miR-29 on insulin signaling might be mediated by other unknown intermediates. Taken together, these data reveal the crucial role of miR-29 in type 2 diabetes.
TL;DR: The data suggest that the rostral cingulate zone activity alone is insufficient to drive error awareness and its signal appears to be useful for post-error speed-accuracy adjustments only when the error is consciously perceived.
Max Planck Society1, Durham University2, North-West University3, Dublin Institute for Advanced Studies4, Heidelberg University5, Humboldt University of Berlin6, University of Erlangen-Nuremberg7, University of Hamburg8, University of Tübingen9, Ruhr University Bochum10, Charles University in Prague11, Yerevan Physics Institute12, University of Namibia13
TL;DR: The combined gamma-ray image of the 2004 and 2005 data reveals the morphology of RX J1713.7-3946 with unprecedented precision, as well as significantly increased statistics and energy coverage as compared to earlier 2003 & 2004 results.
Abstract: We present deep H.E.S.S. observations of the supernova remnant (SNR) RX J1713.7-3946. Combining data of three years - from 2003 to 2005 - we obtain significantly increased statistics and energy coverage as compared to earlier 2003 & 2004 results. The data are analysed separately for the different years. Very good agreement of the gamma-ray morphology and the differential spectra is found when comparing the three years. The combined gamma-ray image of the 2004 and 2005 data reveals the morphology of RX J1713.7-3946 with unprecedented precision. An angular resolution of 0.06 deg is achieved, revealing the detailed structure of the remnant. The combined spectrum of all three years extends over three orders of magnitude, with significant gamma-ray emission approaching 100 TeV. The cumulative significance above 30 TeV is 4.8 sigma, while for energies between 113 and 294 TeV an upper limit on the gamma-ray flux of 1.6 x 10^-16 cm^-2 s^-1 is obtained. The energy coverage of the H.E.S.S. data is presumably at the limit of present generation Cherenkov telescopes. The measurement of significant gamma-ray emission beyond 30 TeV formally implies the existence of primary particles of at least that energy. However, for realistic scenarios of very-high-energy gamma-ray production, the Inverse Compton scattering of very-high-energy electrons and pi^0 decay following inelastic proton-proton interactions, the measured gamma-ray energies imply that efficient acceleration of primary particles to energies exceeding 100 TeV is taking place in the shell of the SNR RX J1713.7-3946.
TL;DR: In this article, the authors estimate a standard principal agent model with constant relative risk aversion and lognormal stock prices for a sample of 598 US CEOs and show that the model predicts contracts that would reduce average compensation costs by 20% while providing the same incentives and the same utility.
Abstract: We estimate a standard principal agent model with constant relative risk aversion and lognormal stock prices for a sample of 598 US CEOs. The model is widely used in the compensation literature, but it predicts that almost all of the CEOs in our sample should hold no stock options. Instead, CEOs should have lower base salaries and receive additional shares in their companies. For a typical value of relative risk aversion, almost half of the CEOs in our sample would be required to purchase additional stock in their companies from their private savings. The model predicts contracts that would reduce average compensation costs by 20% while providing the same incentives and the same utility to CEOs. We investigate a number of extensions and modi.cations of the standard model, but .nd none of them to be satisfactory. We conclude that the standard principal agent model typically used in the literature cannot rationalize observed contracts. One reason may be that executive pay contracts are suboptimal.
TL;DR: It is hypothesized that phage have evolved to use upregulated host genes, leading to their stable incorporation into phage genomes and their subsequent transfer back to hosts in genome islands, and activation of host genes during infection may be directing the co-evolution of gene content in both host and phages genomes.
Abstract: It's known that interactions between bacteria and their viruses (or phages) can result in a degree of co-evolution of host and phage. A picture of just how close that relationship can become is given by whole-genome expression profiling of the marine cyanobacterium Prochlorococcus and its T7-like cyanophage during infection. A number of host genes are expressed in a coordinated fashion during phage infection, and the phage seem to have evolved to make good use of the gene products. These cyanobacteria are ubiquitous in the oceans and dominant in their particular niche. It seems likely that evolutionary cooperation between host and phage contributes to the success of both partners. Phages have a major impact on the evolution of their bacterial hosts. Providing the first whole genome expression profiling of the marine cyanobacterium Prochlorococcus and its T7-like cyanophage during lytic infection reveals potential mechanistic features of this co-evolutionary process. Interactions between bacterial hosts and their viruses (phages) lead to reciprocal genome evolution through a dynamic co-evolutionary process1,2,3,4,5. Phage-mediated transfer of host genes—often located in genome islands—has had a major impact on microbial evolution1,4,6. Furthermore, phage genomes have clearly been shaped by the acquisition of genes from their hosts2,3,5. Here we investigate whole-genome expression of a host and phage, the marine cyanobacterium Prochlorococcus MED4 and the T7-like cyanophage P-SSP7, during lytic infection, to gain insight into these co-evolutionary processes. Although most of the phage genome was linearly transcribed over the course of infection, four phage-encoded bacterial metabolism genes formed part of the same expression cluster, even though they are physically separated on the genome. These genes—encoding photosystem II D1 (psbA), high-light inducible protein (hli), transaldolase (talC) and ribonucleotide reductase (nrd)—are transcribed together with phage DNA replication genes and seem to make up a functional unit involved in energy and deoxynucleotide production for phage replication in resource-poor oceans. Also unique to this system was the upregulation of numerous genes in the host during infection. These may be host stress response genes and/or genes induced by the phage. Many of these host genes are located in genome islands and have homologues in cyanophage genomes. We hypothesize that phage have evolved to use upregulated host genes, leading to their stable incorporation into phage genomes and their subsequent transfer back to hosts in genome islands. Thus activation of host genes during infection may be directing the co-evolution of gene content in both host and phage genomes.
TL;DR: This study highlights the need to understand more fully the role that sanitation plays in the quality of life of individuals in different cultural or national settings.
Abstract: SUMMARY Background The impact of constipation on quality of life (QoL) may vary in different cultural or national settings. Aim We studied QoL in a multinational survey to compare different social and demographic groups with and without constipation (defined according to Rome III criteria) and to detect country-specific differences among the groups studied. Methods Health-related QoL (HRQoL) was assessed with the Short Form 36 (SF-36) questionnaire in 2870 subjects in France, Germany, Italy, UK, South Korea, Brazil and USA. Results Respondents were mainly middle-aged, married or living together and part- or full-time employed. General health status, measured by the SF-36 questionnaire, was significantly worse in the constipated vs. nonconstipated populations. Results were comparable in all countries. QoL scores correlated negatively with age. Constipated women reported more impaired HRQoL than constipated men. Brazilians were most affected by constipation as to their social functioning (35.8 constipated vs. 51.3 non-constipated) and general health perception (29.4 constipated vs. 54.4 non-constipated). Conclusions There are significant differences in HRQoL between constipated and non-constipated individuals and a significant, negative correlation between the number of symptoms and complaints and SF-36 scores. The study detected a correlation of constipation with QoL and the influence of social and demographic factors on HRQoL in constipated people.