160 research outputs found
The origin of human chromosome 2 analyzed by comparative chromosome mapping with a DNA microlibrary
Fluorescencein situ hybridization (FISH) of microlibraries established from distinct chromosome subregions can test the evolutionary conservation of chromosome bands as well as chromosomal rearrangements that occurred during primate evolution and will help to clarify phylogenetic relationships. We used a DNA library established by microdissection and microcloning from the entire long arm of human chromosome 2 for fluorescencein situ hybridization and comparative mapping of the chromosomes of human, great apes (Pan troglodytes, Pan paniscus, Gorilla gorilla, Pongo pygmaeus) and Old World monkeys (Macaca fuscata andCercopithecus aethiops). Inversions were found in the pericentric region of the primate chromosome 2p homologs in great apes, and the hybridization pattern demonstrates the known phylogenetically derived telomere fusion in the line that leads to human chromosome 2. The hybridization of the 2q microlibrary to chromosomes of Old World monkeys gave a different pattern from that in the gorilla and the orang-utan, but a pattern similar to that of chimpanzees. This suggests convergence of chromosomal rearrangements in different phylogenetic lines
Comparative chromosome band mapping in primates byin situ suppression hybridization of band specific DNA microlibraries
A DNA-library established from microdissected bands 8q23 to 8q24.1 of normal human chromosomes 8 (Lüdecke et al., 1989) was used as a probe for chromosomal in situ suppression (CISS-) hybridization to metaphase chromosomes of man and primates including Hylobates lar and Macaca fuscata. Comparative band mapping as first applied in this study shows the specific visualization of a single subchromosomal region in all three species and thus demonstrates that synteny of the bulk sequences of a specific human chromosome subregion has been conserved for more than 20 million years
Symmetry structure and phase transitions
We study chiral symmetry structure at finite density and temperature in the
presence of external magnetic field and gravity, a situation relevant in the
early Universe and in the core of compact stars.
We then investigate the dynamical evolution of phase transition in the
expanding early Universe and possible formation of quark nuggets and their
survival.Comment: Plenary talk given at the 4th. ICPAQGP held at Jaipur, India from Nov
26-30, 2001.laTex 2e file with 8 ps figures and 12 page
Northeastern Atlantic cold-water coral reefs and climate
U-series age patterns obtained on reef framework-forming cold-water corals collected over a nearly 6,000 km long continental margin sector, extending from off Mauritania to the south-western Barents Sea reveal strong climate influences on the geographical distribution and sustained development of these ecosystems. During glacial times densely populated cold-water coral reefs flourished in the temperate east Atlantic, where at present only scarce live coral occurrences exist. In contrast, climate warming induces a rapid northward colonization of cold-water coral reefs with the biogeographic limit advancing from ~45°N to ~70°N. Thus, we invoke here that north-south oscillations of the polar front during the past glacial-interglacial cycles and the consequent displacement of cold nutrient-rich intermediate waters and productivity drives the decline and expansion of cold-water coral ecosystems and its biogeographic limits in the northeast Atlantic
Comparative chromosome painting discloses homologous Segments in distantly related mammals
Comparative chromosome painting, termed ZOO-FISH, using DNA libraries from flow
sorted human chromosomes 1,16,17 and X, and mouse chromosome 11 discloses the
presence of syntenic groups in distantly related mammalian Orders ranging from
primates (Homo sapiens), rodents (Mus musculus), even-toed ungulates (Muntiacus
muntjak vaginalis and Muntiacus reevesi) and whales (Balaenoptera physalus). These
mammalian Orders have evolved separately for 55-80 million years (Myr). We conclude
that ZOO-FISH can be used to generate comparative chromosome maps of a large
number of mammalian species
Insights on Privacy and Ethics from the Web's Most Prolific Storytellers
An analysis of narratives in English-language weblogs re-veals a unique population of individuals who post personal stories with extraordinarily high frequency over extremely long periods of time. This population includes people who have posted personal narratives everyday for more than eight years. In this paper we describe our investigation of this interesting subset of web users, where we conducted ethno-graphic, face-to-face interviews with a sample of these blog-gers (n = 11). Our findings shed light on a culture of public documentation of private life, and provide insight into these bloggers ’ motivations, interactions with their readers, hon-esty, and thoughts on research that utilizes their data. We discuss the ethical implications for researchers working with web data, and speak to the relationship between large social media datasets and the real people behind them
Chiral symmetry in linear Sigma model in magnetic environment
We study the chiral symmetry structure in a linear sigma model with fermions
in the presence of an external, uniform magnetic field in the 'effective
potential' approach at the one loop level. We also study the chiral phase
transition as a function of density in the core of magnetized neutron stars.Comment: LaTex2e file with six postscript figures. journal ref: Physical
Review D 62 (2000) 02502
Environmental forcing of the Campeche cold-water coral province, southern Gulf of Mexico
With an extension of >40 km2 the recently discovered Campeche cold-water coral province located at the northeastern rim of the Campeche Bank in the southern Gulf of Mexico belongs to the largest coherent cold-water coral areas discovered so far. The Campeche province consists of numerous 20 to 40 m high coral ridges that are developed in intermediate water depths of 500 to 600 m. The ridges are colonized by a vivid cold-water coral ecosystem that covers the upper flanks and summits. The rich coral community is dominated by the framework-building scleractinia Enallopsammia profunda and Lophelia pertusa while the associated benthic megafauna shows a rather scarce occurrence. The recent environmental setting is characterized by a high surface water production caused by a local upwelling center and a dynamic bottom water regime comprising vigorous bottom currents, internal waves and strong density contrasts, which all together provide optimal conditions for the growth of cold-water corals. The strong hydrodynamics – potentially supported by the diel vertical migration of zooplankton in the Campeche area – drive the delivering of food particles to the corals. The Campeche cold-water coral province is, thus, an excellent example highlighting the importance of the hydrographic setting in securing the food supply for the development of large and vivid cold-water coral ecosystems
La construcción simbólica del futuro en los discursos científico-tecnológicos de las industrias culturales: EPCOT como caso de estudio
Imaginar cómo podemos mejorar nuestra calidad de vida a partir de las innovaciones científicas y tecnológicas ha sido uno de los temas principales de diversas instituciones e industrias culturales como la cinematografía y los museos. A diferencia de las palabras modernización o desarrollo, el concepto de progreso denota cambios de más de un tipo y representa una identidad cultural influenciada por el ethos de cada época. El problema de esta investigación radica en el esfuerzo, por parte de diversos organismos y corporaciones de mantener una ideología del progreso al proponer discursivamente sus percepciones del tema y legitimarlos por medio de mensajes científico-tecnológicos expuestos especialmente a través de las industrias culturales, consideradas medios masivos que ayudan a perpetuar discursos dominantes sobre diversos temas. Lo anterior se aborda desde la teoría de comunicación del sociólogo estadounidense John B. Thompson (1997) y la hermenéutica profunda. El caso de estudio se centra en el parque temático EPCOT. Entre los resultados se encuentra que la construcción de la noción del progreso se ve fuertemente influenciada por los intereses comerciales de los patrocinadores. Por otro lado, el futuro se presenta como uno utópico y extremadamente optimista sin cuestionamiento o disrupción alguna, esta percepción permeó el desarrollo de Estados Unidos durante el siglo XX y luchó por permanecer vigente durante el siglo XXI a pesar de las guerras y las crisis
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