Understanding the Observed Evolution of the Galaxy Luminosity Function from z=6-10 in the Context of Hierarchical Structure Formation

Recent observations of the Lyman-break galaxy (LBG) luminosity function (LF) from z~6-10 show a steep decline in abundance with increasing redshift. However, the LF is a convolution of the mass function of dark matter halos (HMF)--which also declines sharply over this redshift range--and the galaxy-formation physics that maps halo mass to galaxy luminosity. We consider the strong observed evolution in the LF from z~6-10 in this context and determine whether it can be explained solely by the behavior of the HMF. From z~6-8, we find a residual change in the physics of galaxy formation corresponding to a ~0.5 dex increase in the average luminosity of a halo of fixed mass. On the other hand, our analysis of recent LF measurements at z~10 shows that the paucity of detected galaxies is consistent with almost no change in the average luminosity at fixed halo mass from z~8. The LF slope also constrains the variation about this mean such that the luminosity of galaxies hosted by halos of the same mass are all within about an order-of-magnitude of each other. We show that these results are well-described by a simple model of galaxy formation in which cold-flow accretion is balanced by star formation and momentum-driven outflows. If galaxy formation proceeds in halos with masses down to 10^8 Msun, then such a model predicts that LBGs at z~10 should be able to maintain an ionized intergalactic medium as long as the ratio of the clumping factor to the ionizing escape fraction is C/f_esc < 10.Comment: 15 pages, 2 figures; results unchanged; accepted by JCA

Main Variables Affecting a Chemical-Enzymatic Method to Obtain Protein and Amino Acids from Resistant Microalgae

he development of microalgae uses requires further investigation in cell disruption alternatives to reduce the costs associated to this processing stage. This study aimed to evaluate the main variables affecting an extraction method to obtain protein and amino acids from microalgae. The method was based on a sequential alkaline-enzymatic process, with separate extractions and noncontrolled pH, and was applied to fresh biomass of a resistant species. The processed microalgae were composed of a consortium with Nannochloropsis sp. as predominant species. After the optimization of the pH of the alkaline reaction, the effect of the time of the alkaline reaction (30-120min), the time (30-120min) and temperature (40-60 degrees C) of the enzymatic reaction, and the biomass concentration (50-150mgml(-1)), on the extraction yields of protein and free amino nitrogen (FAN) and on the final concentration of protein in the extract, was studied using a response surface methodology. Even though all the variables and some interactions among them had a significant effect, the biomass concentration was the most important factor affecting the overall process. The results showed relevant information about the different options in order to maximize not only the response variables individually but also different combinations of them. Assays with optimized values reached maximum yields of 80.3% and 1.07% of protein (% of total protein) and FAN (% of total biomass), respectively, and a protein concentration in the extract of 15.2mgml(-1). The study provided the essential information of an alternative approach to obtain protein and amino acids from fresh biomass of resistant microalgae with a high yield, also opening perspectives for further research in particular aspects

Razón pública y multiculturalismo

Este artículo trata de afrontar el alcance de la razón pública en el mundo actual donde la diversidad cultural es un hecho reconocido o, cuando menos, en vías de reconocimiento. Parte del proceso histórico de conformación social racional que ha consolidado el espacio político y la vida pública para evidenciar sus deficiencias, limitaciones y distorsiones en relación con la complejidad cultural humana. Destaca que su carácter transformador de la vida social, tendente a la consolidación racional de un espacio público homogéneo, margina el sentido originario del derecho y la moral que dotaban de legitimidad a los grupos humanos comunitarios con cultura propia y obstruye su supervivencia. Para resolver el papel legítimo en la vida social de las comunidades culturales, en desventaja respecto a la razón dominante en el espacio público, propone un derecho universalista que posibilite el bien común y la prestación comunitaria de seivicios, en términos más empresariales que políticos

Sobre la indefensión de lo público

En opinión de d’Ors la exaltación contemporánea de lo social no es en realidad el reflejo de un mayor respeto por lo público, más bien al contrario. El autor analiza uno de los trabajos de d’Ors en el que señala diversas manifestaciones que constituyen abusos de derecho por parte de particulares o de grupos de interés y que invaden el espacio (real o figurado) de lo público.In the opinion of Álvaro d'Ors the contemporary exaltation of what is social is not in fact a reflection of a greater respect for what is public; rather the opposite. The author analyzes one of the works of d'Ors in which he points out various manifestations of abuse of their right by individuals or interest groups and that invade the space (real or figurative) of what is public

El imperativo honra como eje de posibles propuestas en relación con el derecho a la educación y la libertad de enseñanza

El panorama que ofrecen las Declaraciones Internacionales de Derechos en materia de enseñanza es completo aunque su eficacia pueda ser limitada según los casos. De ahí que no sea fácil formular propuestas innovadoras. Sin embargo, el reconocimiento de la dignidad humana y su respeto –expresado en el imperativo honra– puede ser una fuente constante de renovación en la búsqueda de soluciones a los problemas concretos que se planteen en la relación educativa. A la vez, las características del Estado social, la forma de entender lo que significa el libre desarrollo de la personalidad o la idea de calidad de vida pueden dificultar la plenitud de los derechos y libertades educativos

Deformation pattern around the Conejera fault blocks (Asturian Basin, North Iberian Margin)

The Asturian Basin is located on the coastline of the North Iberian Margin. This basin is dissected by long-lived E-, NE- and NW-striking faults that delineate a series of extensional fault blocks that became shortened during the Upper Cretaceous to Cenozoic Alpine convergence. In the Conejera cove, the NE-striking and SE-dipping Conejera Fault displays a remarkable example of contractional deformation, promoted by the mechanical contrast within the Lower to Middle Jurassic stratigraphic series. Field observations and structural analysis carried out in this study reveal: i) a first system of orthogonal cross-joints oblique to the Conejera Fault and other major onshore boundary faults, ii) a second system of meso-extensional faults parallel to the Conejera Fault, and developed by the reactivation and linkage of the orthogonal cross-joints and iii) a series of contractional folds, thrusts and pressure solution with a predominant NE to ENE trend. Observed relationships and structural analysis suggest an obliquity between the here inferred direction of the Late Jurassic-Early Cretaceous stretching (i.e. about N015E) and the onshore boundary faults, whereas the contractional structures are broadly parallel to the NE-striking Conejera Fault and suggest a roughly SSE- to SE-oriented Alpine convergence

Long-term functional outcomes of the terrible triad of the elbow

Introduction: The published literature regarding the terrible triad of the elbow has historically shown a high rate of unacceptable outcomes. The objective of the present study was to evaluate the long-term functional outcomes and repercussions in patients who suffered the terrible triad of the elbow. Material and methods: A retrospective analysis of a prospectively-recruited consecutive series of cases registered from August 2005 to August 2009, involving 27 patients from which 16 complied with inclusion criteria for the study. The mean follow-up period was 8.6 years (range: 6.9 to 10.6). Two different final quality of life evaluation questionnaires were performed by telephone: the EuroQol Five Dimensions Questionnaire (EQ-5D) and the patient answered questionnaire portion of the Liverpool Elbow Score (PAQ-LES). Results: Fifteen (93.7%) patients were intervened surgically whereas only 1 case was treated conservatively. EQ-5D-rated outcome averaged 0.87 (range: 0.36 to 1) and the PAQ-LES averaged 33.5 (range: 17 to 36). Five (31.2%) presented pain or discomfort, 4 (25.0%) had some kind of difficulties in their daily activity and 3 (18.7%) founded some limitations with their personal hygiene. Only 6 cases (37.5%) declared to be fully asymptomatic. Conclusion: The terrible triad of the elbow remains a challenging injury that entails the presence of chronic pain and discomfort in almost one third of the cases at a long-term follow-up

Electrical and magnetic properties of ferritin: electron transport phenomena and electron paramagnetic resonance

Ferritin is a spherical metalloprotein, capable of storing and releasing iron in a controllable way. It is composed of a protein shell of about 12 nm and within its cavity, iron is stored in a mineral form. The ferritin core resembles an iron-based nanoparticle that is isolated from the environment by the ferritin shell, which makes ferritin an attractive element to be used in the fabrication of bioelectronic devices. Another intriguing aspect of ferritin is its potential relation to neurodegenerative diseases, such as Alzheimer’s and Parkinson’s. The relation is not yet well understood, but the studies indicate that dysfunctional ferritin appears to play an important role. This dissertation aims to characterize ferritin electrically and magnetically. First, the electrical properties of single ferritin are explored to understand the charge transport through ferritin, and additionally, the first ferritin single-electron transistor is obtained. Second, the magnetic properties of multiple ferritin particles are studied by electron paramagnetic resonance, which supplies information about the ferritin core. A model of the electron-spin structure of the ferritin core is proposed and extended to the ferritin signal from post-mortem brain tissues.NWO, through Nanofront project number NF17SYN05 NWA.1228.191.414Biological and Soft Matter Physic

New measures for assessing model equilibrium and prediction mismatch in species distribution models

Models based on species distributions are widely used and serve important purposes in ecology, biogeography and conservation. Their continuous predictions of environmental suitability are commonly converted into a binary classification of predicted (or potential) presences and absences, whose accuracy is then evaluated through a number of measures that have been the subject of recent reviews. We propose four additional measures that analyse observation-prediction mismatch from a different angle – namely, from the perspective of the predicted rather than the observed area – and add to the existing toolset of model evaluation methods. We explain how these measures can complete the view provided by the existing measures, allowing further insights into distribution model predictions. We also describe how they can be particularly useful when using models to forecast the spread of diseases or of invasive species and to predict modifications in species’ distributions under climate and land-use chang

Analogue Modelling of Inverted Oblique Rift Systems

The geometric evolution of brittle fault systems in inverted oblique and offset rift systems has been simulated using scaled sandbox analogue models. Dry fine-grained quartz sand was used to represent the brittle upper crust. Extensional faults geometries in the models were governed by the geometry and orientation of a stretching zone at the base of the models. Oblique rift models were characterized by segmented en-echelon border fault systems trending parallel to the rift axis and the underlying zone of basement stretching. Offset rift models promoted highly-segmented border faults as well as offset sub-basins within the rift. In both types of models, intra-rift fault arrays were oriented sub-perpendicular to the extension direction. Inversion of the oblique and offset extensional models was achieved by horizontal shortening. This resulted in partial inversion of the border and intra-rift faults as well as the formation of new reverse faults. The geometries, distribution, orientations and number of these new reverse faults were strongly controlled by the earlier-formed fault extensional architectures. At the margins of the rift zone, shortening was mainly accommodated by partial inversion of the border faults together with the formation of hanging-wall bypass faults and footwall shortcut thrusts. Inversion of the offset rift models produced reactivation of the extensional accommodation zones as soft-linked transfer zones between new thrust faults. The analogue model results have been compared with natural inversion structures in the Atlas Mountains of Morocco and the Ukrainian Donbas fold belt. The analogue modelling results suggest that the High Atlas formed as the result of oblique inversion of an oblique rift system, and the contractional structures in the Ukranian Donbas belt were generated by partial inversion of the earlier-formed Donbas extensional graben via two major newly developed short-cuts that uplifted and exhumed the basin