Surface Complexation of Selenite on Goethite: MO/DFT Geometry and Charge Distribution

The adsorption of selenite on goethite (a-FeOOH) has been analyzed with the charge distribution (CD) and the multi-site surface complexation (MUSIC) model being combined with an extended Stern (ES) layer model option. The geometry of a set of different types of hydrated iron-selenite complexes has been calculated using Molecular Orbital / Density Functional Theory (MO/DFT). The optimized geometries have been interpreted with the Brown bond valence approach resulting in a set of ionic charge distribution values. After correction for dipole orientation effects, it results in the interfacial charge distribution coefficients that can be applied to the analysis of adsorption data. The use of theoretical CD values has the practical advantage of a reduction of the number of adjustable parameters. From a theoretical perspective, the CD values can constrain the model, revealing a surface speciation that can be tested experimentally. Modeling of the adsorption of SeO3 in (pseudo-) monocomponent goethite systems, using the calculated CD values, has revealed the dominant presence of a bidentate surface species º(FeO)2SeO. The dominance of this surface species agrees with the interpretation of EXAFS measurements given in literature. The agreement supports the validity of the approach. To describe the adsorption at very low pH and a high loading, formation of an additional surface species is required in the modeling. The maximum contribution is about 20 % or less. In case of anion competition, as found in the PO4-SeO3 goethite system, the relative contribution increases. Analysis of the adsorption behavior in the PO4-SeO3 goethite systems revealed the probable nature of the additional surface complex, which is found to be a protonated monodentate surface complex ºFeOSeOOH. With the affinity constants derived, the CD model is able to describe the SeO3 adsorption on goethite over a large range of pH, ionic strength, and loading conditions for a variety of goethite preparations. The CD model correctly predicts the proton co-adsorption of selenite and is able to describe the shift of the IEP upon addition of selenite

Tracing species replacement in Iberian marbled newts

Animal science

The single morpheme -ed/-en of the English past/passive

All English regular verbs and about half its irregular verbs have the same form for the finite past tense and the past participle. The finite past tense is different from the participle only for a closed class of about 100 irregular verbs. These latter can be analyzed by a lexical device of wide-ranging applicability called Alternative Realization. All other Past forms of Vs, finite and non-finite, can then be derived from a single morpheme -ed which appears in two contexts: one when V is finite and one when it is selected by a semantically empty stative verb, have or be. There is also a third use of -ed to form passive participles, in both verbal and adjectival passives.The paper presents a formalized system of selection features for lexical items including but going beyond classical subcategorization. This system permits formulating a single full lexical entry for the suffix -ed that covers all its uses. The final version of this entry exemplifies how to specify Alternative Realization, uninterpretability of categories and disjunctive contexts, and independently justifies each of these notations

A genomic footprint of a moving hybrid zone in marbled newts

Animal science

O fator fake news na atualidade, na mira da psicologia

With this article we pretend to define and understand the central aspects of Fake News. This event has gain attention in personal conversations and in the social media. It is important to understand how this phenome happens and how the receptor is persuaded to believe in the massage,so wecan understand the damage it can cause in the society, for example the elections that have been directly affected for this phenome and establish how to prevent it. Based in studies of other authors we understood the motivations and elements necessary to make and disseminate the information. Since fake news look like real ones its easier for people to believe in them without questioning. Considering the difficult and complexity of the combat of fake news, at the end of this article we analyse a few methods that are been used and highlight the favourable points and possible advances.Vivemos na era da informação digital e rápida. Hoje em dia constatamos infelizmente que mesmo em situação de crise, como a que estamos a viver face ao Covid19, as fake news aparecem e alastram-se comprometendo muitas vezes situações delicadas. Assim tem como objetivo este estudo exploratório definir e perceber as principais questões envolvidas na existência das fake news. Esta terminologia tem ganhado fama entre várias conversas e é um tema presente nas redes sociais. Entender como este fenómeno ocorre e em que medida ele pode persuadir o recetor da mensagem é importante para analisar os danos causado na sociedade, como por exemplo as eleições que foram afetadas diretamente por esses tipos de notícias, e estabelecer um método preventivo. Na análise de diferentes estudos já realizados constatou-se que existem motivações e elementos essenciais para a produção e disseminação deste tipo de informação. As fake news parecem noticias verdadeiras e isso aumenta a possibilidade de que as pessoas acedam essas informações e acreditem na sua veracidade sem que esta seja verificada.Como combater a disseminação destas informações não é simples, a psicologia com toda a sua humildade e bem querer, numa promoção continua de positividade e lucidez procurará sempre analisar algumas medidas já utilizadas, destacando vantagens e possíveis melhorias

Aptamer-based multiplexed proteomic technology for biomarker discovery

Interrogation of the human proteome in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology. We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 [mu]L of serum or plasma). Our current assay allows us to measure ~800 proteins with very low limits of detection (1 pM average), 7 logs of overall dynamic range, and 5% average coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding DNA aptamer concentration signature, which is then quantified with a DNA microarray. In essence, our assay takes advantage of the dual nature of aptamers as both folded binding entities with defined shapes and unique sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to discover unique protein signatures characteristic of various disease states. More generally, we describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine