108 research outputs found
Knowledge Integration and Diffusion: Measures and Mapping of Diversity and Coherence
I present a framework based on the concepts of diversity and coherence for
the analysis of knowledge integration and diffusion. Visualisations that help
understand insights gained are also introduced. The key novelty offered by this
framework compared to previous approaches is the inclusion of cognitive
distance (or proximity) between the categories that characterise the body of
knowledge under study. I briefly discuss the different methods to map the
cognitive dimension
Catheter Colonization and Abscess Formation Due to Staphylococcus epidermidis with Normal and Small-Colony-Variant Phenotype Is Mouse Strain Dependent
Coagulase-negative staphylococci (CoNS) form a thick, multilayered biofilm on foreign bodies and are a major cause of nosocomial implant-associated infections. Although foreign body infection models are well-established, limited in vivo data are available for CoNS with small-colony-variant (SCV) phenotype described as causative agents in implant-associated infections. Therefore, we investigated the impact of the Staphylococcus epidermidis phenotype on colonization of implanted PVC catheters and abscess formation in three different mouse strains. Following introduction of a catheter subcutaneously in each flank of 8- to 12-week-old inbred C57BL/6JCrl (B6J), outbred Crl:CD1(ICR) (CD-1), and inbred BALB/cAnNCrl (BALB/c) male mice, doses of S. epidermidis O-47 wild type, its hemB mutant with stable SCV phenotype, or its complemented mutant at concentrations of 106 to 109 colony forming units (CFUs) were gently spread onto each catheter. On day 7, mice were sacrificed and the size of the abscesses as well as bacterial colonization was determined. A total of 11,500 CFUs of the complemented mutant adhered to the catheter in BALB/c followed by 9,960 CFUs and 9,900 CFUs from S. epidermidis wild type in BALB/c and CD-1, respectively. SCV colonization was highest in CD-1 with 9,500 CFUs, whereas SCVs were not detected in B6J. The minimum dose that led to colonization or abscess formation in all mouse strains was 107 or 108 CFUs of the normal phenotype, respectively. A minimum dose of 108 or 109 CFU of the hemB mutant with stable SCV phenotype led to colonization only or abscess formation, respectively. The largest abscesses were detected in BALB/c inoculated with wild type bacteria or SCV (64 mm2 vs. 28 mm2). Our results indicate that colonization and abscess formation by different phenotypes of S. epidermidis in a foreign body infection model is most effective in inbred BALB/c followed by outbred CD-1 and inbred B6J mice
Copy Number Variation Affecting the Photoperiod-B1 and Vernalization-A1 Genes Is Associated with Altered Flowering Time in Wheat (Triticum aestivum)
The timing of flowering during the year is an important adaptive character affecting reproductive success in plants and is critical to crop yield. Flowering time has been extensively manipulated in crops such as wheat (Triticum aestivum L.) during domestication, and this enables them to grow productively in a wide range of environments. Several major genes controlling flowering time have been identified in wheat with mutant alleles having sequence changes such as insertions, deletions or point mutations. We investigated genetic variants in commercial varieties of wheat that regulate flowering by altering photoperiod response (Ppd-B1 alleles) or vernalization requirement (Vrn-A1 alleles) and for which no candidate mutation was found within the gene sequence. Genetic and genomic approaches showed that in both cases alleles conferring altered flowering time had an increased copy number of the gene and altered gene expression. Alleles with an increased copy number of Ppd-B1 confer an early flowering day neutral phenotype and have arisen independently at least twice. Plants with an increased copy number of Vrn-A1 have an increased requirement for vernalization so that longer periods of cold are required to potentiate flowering. The results suggest that copy number variation (CNV) plays a significant role in wheat adaptation
Gravitational-wave research as an emerging field in the Max Planck Society. The long roots of GEO600 and of the Albert Einstein Institute
On the occasion of the 50th anniversary since the beginning of the search for
gravitational waves at the Max Planck Society, and in coincidence with the 25th
anniversary of the foundation of the Albert Einstein Institute, we explore the
interplay between the renaissance of general relativity and the advent of
relativistic astrophysics following the German early involvement in
gravitational-wave research, to the point when gravitational-wave detection
became established by the appearance of full-scale detectors and international
collaborations. On the background of the spectacular astrophysical discoveries
of the 1960s and the growing role of relativistic astrophysics, Ludwig Biermann
and his collaborators at the Max Planck Institute for Astrophysics in Munich
became deeply involved in research related to such new horizons. At the end of
the 1960s, Joseph Weber's announcements claiming detection of gravitational
waves sparked the decisive entry of this group into the field, in parallel with
the appointment of the renowned relativist Juergen Ehlers. The Munich area
group of Max Planck institutes provided the fertile ground for acquiring a
leading position in the 1970s, facilitating the experimental transition from
resonant bars towards laser interferometry and its innovation at increasingly
large scales, eventually moving to a dedicated site in Hannover in the early
1990s. The Hannover group emphasized perfecting experimental systems at pilot
scales, and never developed a full-sized detector, rather joining the LIGO
Scientific Collaboration at the end of the century. In parallel, the Max Planck
Institute for Gravitational Physics (Albert Einstein Institute) had been
founded in Potsdam, and both sites, in Hannover and Potsdam, became a unified
entity in the early 2000s and were central contributors to the first detection
of gravitational waves in 2015.Comment: 94 pages. Enlarged version including new results from further
archival research. A previous version appears as a chapter in the volume The
Renaissance of General Relativity in Context, edited by A. Blum, R. Lalli and
J. Renn (Boston: Birkhauser, 2020
Sequence Composition and Gene Content of the Short Arm of Rye (Secale cereale) Chromosome 1
BACKGROUND: The purpose of the study is to elucidate the sequence composition of the short arm of rye chromosome 1 (Secale cereale) with special focus on its gene content, because this portion of the rye genome is an integrated part of several hundreds of bread wheat varieties worldwide. METHODOLOGY/PRINCIPAL FINDINGS: Multiple Displacement Amplification of 1RS DNA, obtained from flow sorted 1RS chromosomes, using 1RS ditelosomic wheat-rye addition line, and subsequent Roche 454FLX sequencing of this DNA yielded 195,313,589 bp sequence information. This quantity of sequence information resulted in 0.43× sequence coverage of the 1RS chromosome arm, permitting the identification of genes with estimated probability of 95%. A detailed analysis revealed that more than 5% of the 1RS sequence consisted of gene space, identifying at least 3,121 gene loci representing 1,882 different gene functions. Repetitive elements comprised about 72% of the 1RS sequence, Gypsy/Sabrina (13.3%) being the most abundant. More than four thousand simple sequence repeat (SSR) sites mostly located in gene related sequence reads were identified for possible marker development. The existence of chloroplast insertions in 1RS has been verified by identifying chimeric chloroplast-genomic sequence reads. Synteny analysis of 1RS to the full genomes of Oryza sativa and Brachypodium distachyon revealed that about half of the genes of 1RS correspond to the distal end of the short arm of rice chromosome 5 and the proximal region of the long arm of Brachypodium distachyon chromosome 2. Comparison of the gene content of 1RS to 1HS barley chromosome arm revealed high conservation of genes related to chromosome 5 of rice. CONCLUSIONS: The present study revealed the gene content and potential gene functions on this chromosome arm and demonstrated numerous sequence elements like SSRs and gene-related sequences, which can be utilised for future research as well as in breeding of wheat and rye
The role of morphine in regulation of cancer cell growth
Morphine is considered the “gold standard” for relieving pain and is currently one of the most effective drugs available clinically for the management of severe pain associated with cancer. In addition to its use in the treatment of pain, morphine appears to be important in the regulation of neoplastic tissue. Although morphine acts directly on the central nervous system to relieve pain, its activities on peripheral tissues are responsible for many of the secondary complications. Therefore, understanding the impact, other than pain control, of morphine on cancer treatment is extremely important. The effect of morphine on tumor growth is still contradictory, as both growth-promoting and growth-inhibiting effects have been observed. Accumulating evidence suggests that morphine can affect proliferation and migration of tumor cells as well as angiogenesis. Various signaling pathways have been suggested to be involved in these extra-analgesic effects of morphine. Suppression of immune system by morphine is an additional complication. This review provides an update on the influence of morphine on the growth and migration potential of tumor cells
Detection of the quantitative trait loci for α-amylase activity on a high-density genetic map of rye and comparison of their localization to loci controlling preharvest sprouting and earliness
corona Is Required for Higher-Order Assembly of Transverse Filaments into Full-Length Synaptonemal Complex in Drosophila Oocytes
The synaptonemal complex (SC) is an intricate structure that forms between homologous chromosomes early during the meiotic prophase, where it mediates homolog pairing interactions and promotes the formation of genetic exchanges. In Drosophila melanogaster, C(3)G protein forms the transverse filaments (TFs) of the SC. The N termini of C(3)G homodimers localize to the Central Element (CE) of the SC, while the C-termini of C(3)G connect the TFs to the chromosomes via associations with the axial elements/lateral elements (AEs/LEs) of the SC. Here, we show that the Drosophila protein Corona (CONA) co-localizes with C(3)G in a mutually dependent fashion and is required for the polymerization of C(3)G into mature thread-like structures, in the context both of paired homologous chromosomes and of C(3)G polycomplexes that lack AEs/LEs. Although AEs assemble in cona oocytes, they exhibit defects that are characteristic of c(3)G mutant oocytes, including failure of AE alignment and synapsis. These results demonstrate that CONA, which does not contain a coiled coil domain, is required for the stable ‘zippering’ of TFs to form the central region of the Drosophila SC. We speculate that CONA's role in SC formation may be similar to that of the mammalian CE proteins SYCE2 and TEX12. However, the observation that AE alignment and pairing occurs in Tex12 and Syce2 mutant meiocytes but not in cona oocytes suggests that the SC plays a more critical role in the stable association of homologs in Drosophila than it does in mammalian cells
Development of Hepatozoon caimani (Carini, 1909) Pessôa, De Biasi & De Souza, 1972 in the Caiman Caiman c. crocodilus, the Frog Rana catesbeiana and the Mosquito Culex fatigans
The sporogony of Hepatozoon caimani has been studied, by light microscopy, in the mosquito Culex fatigans fed on specimens of the caiman Caiman c. crocodilus showing gametocytes in their peripheral blood. Sporonts iniciate development in the space between the epithelium of the insect gut and the elastic membrane covering the haemocoele surface of the stomach. Sporulating oocysts are clustered on the gut, still invested by the gut surface membrane. Fully mature oocysts were first seen 21 days after the blood-meal. No sporogonic stages were found in some unidentified leeches fed on an infected caiman, up to 30 days following the blood-meal. When mosquitoes containing mature oocysts were fed to frogs (Leptodactylus fuscus and Rana catesbeiana), cysts containing cystozoites developed in the internal organs, principally the liver. Feeding these frogs to farm-bred caimans resulted in the appearance of gametocytes in their peripheral blood at some time between 59 and 79 days later, and the development of tissue cysts in the liver, spleen, lungs and kidneys. Transmission of the parasite was also obtained by feeding young caimans with infected mosquitoes and it is suggested that both methods occur in nature. The finding of similar cysts containing cystozoites in the semi-aquatic lizard Neusticurus bicarinatus, experimentally fed with infected C. fatigans, suggests that other secondary hosts may be involved
- …