Intra- and intercellular fluctuations in Min-protein dynamics decrease with cell length

Self-organization of proteins in space and time is of crucial importance for the functioning of cellular processes. Often, this organization takes place in the presence of strong random fluctuations due to the small number of molecules involved. We report on stochastic switching of the Min-protein distributions between the two cell halves in short Escherichia coli cells. A computational model provides strong evidence that the macroscopic switching is rooted in microscopic noise on the molecular scale. In longer bacteria, the switching turns into regular oscillations that are required for positioning of the division plane. As the pattern becomes more regular, cell-to-cell variability also lessens, indicating cell length-dependent regulation of Min-protein activity.Comment: Article and Supplementary Information: 26 pages, 12 figure

The aquaporins

Water is the major component of all living cells, and efficient regulation of water homeostasis is essential for many biological processes. The mechanism by which water passes through biological membranes was a matter of debate until the discovery of the aquaporin water channels. Aquaporins are intrinsic membrane proteins characterized by six transmembrane helices that selectively allow water or other small uncharged molecules to pass along the osmotic gradient. In addition, recent observations show that some aquaporins also facilitate the transport of volatile substances, such as carbon dioxide (CO(2)) and ammonia (NH(3)), across membranes. Aquaporins usually form tetramers, with each monomer defining a single pore. Aquaporin-related proteins are found in all organisms, from archaea to mammals. In both uni- and multicellular organisms, numerous isoforms have been identified that are differentially expressed and modified by post-translational processes, thus allowing fine-tuned tissue-specific osmoregulation. In mammals, aquaporins are involved in multiple physiological processes, including kidney and salivary gland function. They are associated with several clinical disorders, such as kidney dysfunction, loss of vision and brain edema

«Poesía arraigada» y noche oscura en la lírica de Blas de Otero

The intertextuality resulting from a continuous dialogue between numerous authors and the work of Saint John of the Cross can be traced -directly or in a more subtle way-throughout the history of Spanish literature, from the Golden Age until the present day. The present article analyzes concepts and images of Saint John's mysticism in the work of Blas de Otero that re-contextualizes them in his postwar poetry, allowing to grant a new semantic to the ideas and work of Saint John of the Cross

Entre catarsis y religación: Una relectura de la obra lírica de Silvina Ocampo

El presente trabajo pretende introducirnos en una faceta casi desconocida de la obra de Silvina Ocampo, la de su vínculo con lo religioso en su obra lírica, donde la autora exhibe una aproximación reverente y un tratamiento casi devoto de figuras de la religión así como de la virtud, el pecado y la culpa, que se analizarán a partir de los conceptos de Paul Ricoeur. Por el contrario, en su narrativa, el ámbito moral aparenta serle indiferente y el religioso se aborda a menudo desde una perspectiva transgresora, irónica o incluso profanatoria. La relación de la obra de Silvina Ocampo con lo religioso ha sido analizada desde esta única perspectiva, tomándose en cuenta sólo su narrativa o atribuyendo erróneamente a toda su lírica estas características. Sin embargo, ignorar la dimensión religiosa –o extrapolar las lecturas de su narrativa sobre este tema a toda su lírica– conlleva un reduccionismo de su obra y la mutilación de la interesante vertiente filosófica y espiritual de la multifacética escritora argentina, que este trabajo intenta sacar a la luz. Asimismo se analizará en su poesía la recepción de las Sagradas Escrituras, cuyas figuras de larga tradición literaria, actúan como vehículo de indagaciones existenciales y filosóficas. El análisis de lo religioso en su lírica abre, desde un enfoque intratextual, nuevas perspectivas sobre polémicos temas de su narrativa, como la violación, la infancia y la figura de la mujer. Palabras clave: Silvina Ocampo, religión, Biblia, culpa, poesíaThis paper aims to introduce us to an almost unknown facet of Silvina Ocampo's work, that of her bond with the religious in her lyrical work, where the author exhibits a reverent approach and an almost devout treatment of religious figures as well as of virtue, sin and guilt, which will be analysed on the basis of Paul Ricoeur's concepts. By contrast, in her narrative, the moral sphere appears to be indifferent to her and the religious sphere is often approached from a transgressive, ironic or even profane perspective. The relationship of Silvina Ocampo's work with the religious has been analysed from her dimension as a transgressive writer, taking into account only her narrative or erroneously including her poetry in this interpretation. However, ignoring the religious dimension or extrapolating the readings of her narrative on this subject to her poetry leads to a reductionism of her work and mutilates the interesting philosophical and spiritual side of this multifaceted Argentinean writer, which this work attempts to bring to light. Likewise, the reception of the Holy Scriptures –in her poetry will be analysed, whose figures, with a long literary tradition, act as a vehicle for existential and philosophical enquiries–. The analysis of the religious in her poetry opens up, from an intratextual approach, new perspectives on polemical themes in her narrative, such as rape, childhood and the feminine figure. Key words: Silvina Ocampo, religion, Bible, guilt, poetr

HELBRED DIG SELV I HISTORISK KONTEKST - SYGDOMSFORTOLKNING OG HISTORIEBRUG I TIDLIG MODERNE OG NUTIDIG SELVHJÆLPSLITTERATUR

ABSTRACTArtiklen undersøger den meningsskabende og handlingsorienterede historiebrug, som tidlig moderne og nutidig selvhjælpslitteratur tilbyder til fortolkning af sygdom. Artiklen viser, hvordan fortidsfortolkningen – der angår årsagen til sygdom – bruges til at håndtere nutidens sygdom og udstikke retningen for, hvad skal der til for fremadrettet at få det bedre eller blive helbredt. To forskellige syndefaldsmyter – en tidlig moderne, der er religiøst og kollektivt funderet og en nutidig, der er individuelt og psykologisk funderet – udgør den overordnede ramme for sygdomsfortolkningen.Forestillingerne om synd som årsag til sygdom og sygdom som straf forsynd viser sig at være ligeså sejlivede i selvhjælpslitteraturen som forestillingerne om selvkontrol og disciplin som vej til helbredelse

Migración y transculturación del tópico del león reverente y agradecido en la literatura fundacional rioplatense de Ruy Díaz de Guzmán

In the context of migration and globalization of the Hispanic culture, and through it, of the most persistent myths and topics of European civilization, we find the work of the mestizo asunceno Ruy Díaz de Guzmán Irala. The inclusion of the topic of the reverent and grateful lion will undergo a process of transculturation in the new Hispanic space and will be adapted to the historical circumstances, in which the confrontation with the other –represented by the indigenous people– reigns. We will compare the Hispanic-American text with El libro de los ejemplos by Clemente Sánchez de Vercial and Corónica del Çid Ruy Díaz, among others. The recontextualization of this topic in the Argentine pampas will serve as a means to exalt the Spanish feat in the Río de la Plata area and the reintegration in the new geographic and social space will enable the depiction of a dichotomic vision (civilization and barbarism) imbued with a continuous tension.En el contexto de la migración y globalización de la cultura hispánica y, a través de esta, de los mitos y tópicos más persistentes de la civilización europea, encontramos la obra del mestizo asunceno Ruy Díaz de Guzmán Irala. La inserción del tópico del león reverente y agradecido sufrirá un proceso de transculturación al nuevo lugar del hispanismo, siendo adaptado a las circunstancias históricas, en las que reina el enfrentamiento con la alteridad, representada por los pueblos originarios. Como fuentes más directas, pondremos el texto hispanoamericano en diálogo con El libro de los ejemplos de Clemente Sánchez de Vercial y Corónica del Çid Ruy Díaz, entre otros. La recontextualización de este tópico en tierras rioplatenses fungirá como vehículo de exaltación de la epopeya española en estas regiones y la reinserción en el nuevo espacio geográfico-social posibilitará la plasmación de una visión dicotómica (civilización y barbarie) impregnada de una continua tensión

«Poesía arraigada» y noche oscura en la lírica de Blas de Otero

La recepción y la consecuente intertextualidad, fruto del diálogo ininterrumpido de los escritores con la obra de san Juan de la Cruz, puede rastrearse —en algunos casos en un primer nivel de lectura o de una manera más recóndita—, a lo largo de la historia de la literatura española desde el Siglo de Oro hasta la actualidad. En el presente trabajo destacaremos conceptos e imágenes de la místicasanjuanista de los que se apropia Blas de Otero, recontextualizándolos en su poesía de posguerra, dando lugar a un proceso de actualización y resemantización del pensamiento y obra sanjuanistas

Late Holocene fire history documented at Lake Khamra, SW Yakutia (Eastern Siberia)

Recent large-scale fire events in Siberia have drawn increased attention to boreal forest fire history. Boreal forests contain about 25% of all global biomass and act as an enormous carbon storage. Fire events are important ecological disturbances connected to the overarching environmental changes that face the Arctic and Subarctic, like vegetation dynamics, permafrost degradation, changes in soil nutrient cycling and global warming, and act as the dominant driver behind boreal forest’s landscape carbon balance. By looking into past fire regimes we can learn about fire frequency and potential linkages to other environmental factors, e.g. fuel types, reconstructed temperature/humidity or geomorphologic landscape dynamics. Unfortunately, fire history data is still very sparse in large parts of Siberia, a region strongly influenced by climate change. The Global Charcoal Database (www.paleofire.org) lists only a handful of continuous charcoal records for all of Siberia, with only three of those featuring published data from macroscopic charcoal as opposed to microscopic charcoal from pollen slides. We aim to reconstruct the late Holocene fire history using lacustrine sediments of Lake Khamra (SW Yakutia at N 59.99°, E 112.98°). It covers an area of c. 4.6 km² with about 22 m maximum water depth, located within the zone of transition from summer-green and larch-dominated to evergreen boreal forest. We present the first continuous, high-resolution (c. 10 years/sample) macroscopic charcoal record (> 150 μm) including information on particle size and morphology for the past c. 2200 years. We compare this to complementary information from microscopic charcoal in pollen slides, a pollen and non-pollen palynomorph record as well as μXRF data. This multi-proxy approach adds valuable data about fire activity in the region and allows a comparison of different prevalent fire reconstruction methods. As the first record of its kind from Siberia, it provides a long-term context for current fire activity in central Siberian boreal forests and enables a better understanding of the environmental interactions occurring in the changing subarctic landscape

Frequency of Microsatellite Instability in Unselected Sebaceous Gland Neoplasias and Hyperplasias

Sebaceous gland neoplasias are the cutaneous manifestation of the Muir–Torre syndrome, which is known to be a phenotypical variant of hereditary nonpolyposis colorectal cancer. Both hereditary nonpolyposis colorectal cancer and Muir–Torre syndrome are caused by inherited DNA mismatch repair defects. As a prominent molecular genetic feature, all tumors associated with a DNA mismatch repair defect exhibit high microsatellite instability. So far, the frequency of DNA mismatch repair defects in patients selected solely on the basis of a sebaceous gland tumor has never been determined. In order to estimate this frequency, we assessed microsatellite instability with up to 10 microsatellite markers in a newly collected unselected series of 25 sebaceous gland neoplasias (six sebaceous adenomas, 16 sebaceous epitheliomas, three sebaceous carcinomas) in comparison to 32 sebaceous gland hyperplasias from unrelated patients. As many as 15 of the 25 sebaceous gland neoplasias (60%), but only one of the 32 sebaceous gland hyperplasias (3%), exhibited high microsatellite instability. Thus, in our study, the majority of patients with a sebaceous gland neoplasia in contrast to patients with a sebaceous gland hyperplasia are highly suspicious for an inherited DNA mismatch repair defect. On the basis of the subsequently collected tumor histories, nine of the 15 patients with a high microsatellite unstable sebaceous gland neoplasia were identified to have Muir–Torre syndrome. In none of these cases, however, were the clinical Amsterdam criteria for diagnosing hereditary nonpolyposis colorectal cancer fulfilled. In the sebaceous tumors of the remaining six patients, high microsatellite instability was an incidental finding. In two of these six patients, single relatives were known to be affected with internal cancer; however, their family histories were not suggestive of Muir–Torre syndrome or hereditary nonpolyposis colorectal cancer. In comparison with microsatellite instability screening studies in a variety of other randomly selected tumors, our study identifies sebaceous gland neoplasias as tumors with the highest frequency of high microsatellite instability reported so far, whereas sebaceous gland hyperplasia rarely exhibits high microsatellite instability. Therefore, screening for microsatellite instability in sebaceous gland neoplasias will be of great value in the detection of an inherited DNA mismatch repair defect, which predisposes to various types of internal cancers