The role of bacteria in pine wilt disease: insights from microbiome analysis.

Pine Wilt Disease (PWD) has a significant impact on Eurasia pine forests. The microbiome of the nematode (the primary cause of the disease), its insect vector, and the host tree may be relevant for the disease mechanism. The aim of this study was to characterize these microbiomes, from three PWD-affected areas in Portugal, using Denaturing Gradient Gel Electrophoresis, 16S rRNA gene pyrosequencing, and a functional inference-based approach (PICRUSt). The bacterial community structure of the nematode was significantly different from the infected trees but closely related to the insect vector, supporting the hypothesis that the nematode microbiome might be in part inherited from the insect. Sampling location influenced mostly the tree microbiome (P < 0.05). Genes related both with plant growth promotion and phytopathogenicity were predicted for the tree microbiome. Xenobiotic degradation functions were predicted in the nematode and insect microbiomes. Phytotoxin biosynthesis was also predicted for the nematode microbiome, supporting the theory of a direct contribution of the microbiome to tree-wilting. This is the first study that simultaneously characterized the nematode, tree and insect-vector microbiomes from the same affected areas, and overall the results support the hypothesis that the PWD microbiome plays an important role in the disease's development

Rocks, minerals, and microscopes: a multimedia application

During the last two decades of the 20th century the boom of the Information Society changed the usual way of teaching and learning. Computers contributed to better classes allowing teachers to make high-quality presentations and eliminating old transparencies and slide collections. The use of multimedia resources, downloaded from the Internet or based on CD-ROM, constitutes a major advantage for the educational system. Unfortunately, many teachers were not able to take advantage of this technological advance due to several factors, namely: bad conditions in schools, resistance to/afraid of using computers, high cost of equipments, and deficient lifelong formation. Geology teaching can be improved by using multimedia materials because geological processes can be better understood as factors like time and scale can be easily simulated. The edition of educational CD-ROMs dedicated to Earth Sciences triggered in the beginning of the nineties. Nevertheless, during the last couple of years, the number of new educational geology-dedicated CD-ROMs decreased. The diversity of subjects is also rather limited. In 2003 the present authors published in a new CD-ROM designated for preuniversity teachers and students entitled ?Rocks and Minerals from Portugal under the Microscope?. This CD-ROM followed a previous on-line version (very simplified and available at http://www.dct.uminho.pt/eng/rpmic_eng/index.html). The CD-ROM helps the visualization of thin sections of rocks and minerals in the lack of polarizing microscopes in classrooms. It also allows self-studying and teachers presentations during classes. This multimedia application describes the preparation of thin sections and the main characteristics of polarizing microscopes by using video support. The observation of thin sections uses QuickTime? technology simulating true microscopical observations in rotating stages viewed with crossed and parallel polars. Each rock specimen is presented with its main characteristics: name, mineralogical composition, texture, structure, place of sampling, and photographs of a hand sample and of the outcrop. The simulation of minerals observation is complemented with information regarding name, chemical composition, crystalline system, cleavage, hardness, color, and industrial applications. Taking advantage of the interactivity and multimedia resources, this CD-ROM can increase the interest of students in the study of rocks and minerals and hence raising awareness of geology

Stable Umbral Chromospheric Structures

Aims. To understand the morphology of the chromosphere in sunspot umbra. We investigate if the horizontal structures observed in the spectral core of the Ca II H line are ephemeral visuals caused by the shock dynamics of more stable structures, and examine their relationship with observables in the H-alpha line. Methods. Filtergrams in the core of the Ca II H and H-alpha lines as observed with the Swedish 1-m Solar Telescope are employed. We utilise a technique that creates composite images and tracks the flash propagation horizontally. Results. We find 0"15 wide horizontal structures, in all of the three target sunspots, for every flash where the seeing was moderate to good. Discrete dark structures are identified that are stable for at least two umbral flashes, as well as systems of structures that live for up to 24 minutes. We find cases of extremely extended structures with similar stability, with one such structure showing an extent of 5". Some of these structures have a correspondence in H-alpha but we were unable to find a one to one correspondence for every occurrence. If the dark streaks are formed at the same heights as umbral flashes then there are systems of structures with strong departures from the vertical for all three analysed sunspots. Conclusions. Long-lived Ca II H filamentary horizontal structures are a common and likely ever-present feature in the umbra of sunspots. If the magnetic field in the chromosphere of the umbra is indeed aligned with the structures, then the present theoretical understanding of the typical umbra needs to be revisited.Comment: Accepted to Astronomy and Astrophysics. Online material (Fig3.mov and Fig4.mov) will be available at A&

O sistema dois-híbridos de Saccharomyces cerevisiae.

Variações e potencial para a análise funcional e montagem de redes de interações proteína-proteína

Measurement of miniband parameters of a doped superlattice by photoluminescence in high magnetic fields

We have studied a 50/50\AA superlattice of GaAs/Al$_{0.21}$Ga$_{0.79}$As composition, modulation-doped with Si, to produce $n=1.4\times 10^{12}$ cm$^{-2}$ electrons per superlattice period. The modulation-doping was tailored to avoid the formation of Tamm states, and photoluminescence due to interband transitions from extended superlattice states was detected. By studying the effects of a quantizing magnetic field on the superlattice photoluminescence, the miniband energy width, the reduced effective mass of the electron-hole pair, and the band gap renormalization could be deduced.Comment: minor typing errors (minus sign in eq. (5)

Physicochemical characterization of biomaterials commonly used in dentistry as bone substitutes--comparison with human bone

The present work focuses on the physicochemical characterization of selected mineral-based biomaterials that are frequently used in dental applications. The selected materials are commercially available as granules from different biological origins: bovine, porcine, and coralline. Natural and calcined human bone were used for comparison purposes. Besides a classical rationalization of chemical composition and crystallinity, a major emphasis was placed on the measurement of various morphostructural properties such as particle size, porosity, density, and specific surface area. Such properties are crucial to acquiring a full interpretation of the in vivo performance. The studied samples exhibited distinct particle sizes (between 200 and 1000 microm) and shapes. Mercury intrusion revealed not only that the total sample porosity varied considerably (33% for OsteoBiol, 50% for PepGen P-15, and 60% for BioOss) but also that a significant percentage of that porosity corresponded to submicron pores. Biocoral was not analyzed by this technique as it possesses larger pores than those of the porosimeter upper limit. The density values determined for the calcined samples were close to the theoretical values of hydroxyapatite. However, the values for the collagenated samples were lower, in accordance with their lower mineral content. The specific surface areas ranged from less than 1 m(2)/g (Biocoral) up to 60 m(2)/g (BioOss). The chemical and phase composition of most of the samples, the exception being Biocoral (aragonite), were hydroxyapatite based. Nonetheless, the samples exhibited different organic material content as a consequence of the distinct heat treatments that each had received

Cosmic microwave background and parametric resonance in reheating

The variation of the perturbative 3-curvature parameter, \zeta, is investigated in the period of reheating after inflation. The two-field model used has the inflaton, with an extra scalar field coupled to it, and non-linear effects of both fields are included as well as a slow decay mechanism into the hydrodynamic fluid of the radiation era. Changes in \zeta occur and persist into the succeeding cosmic eras to influence the generation of the cosmic microwave background fluctuations.Comment: 21 pages, 6 figures.Corrects misprinted formula and 2 number

Searching for galaxy clusters in the VST-KiDS Survey

We present the methods and first results of the search for galaxy clusters in the Kilo Degree Survey (KiDS). The adopted algorithm and the criterium for selecting the member galaxies are illustrated. Here we report the preliminary results obtained over a small area (7 sq. degrees), and the comparison of our cluster candidates with those found in the RedMapper and SZ Planck catalogues; the analysis to a larger area (148 sq. degrees) is currently in progress. By the KiDS cluster search, we expect to increase the completeness of the clusters catalogue to z = 0.6-0.7 compared to RedMapper.Comment: 5 pages, 4 figures, to be published in the Proceedings of the Conference "The Universe of Digital Sky Surveys", Naples, November 25-28 201

Can geosites be restored? The example of the Alto Vez geosite (Peneda Mountain, Portugal)

One of the most important tasks in geoheritage management is the conservation of the geosite values, protecting them from natural or human induced degradation. In some cases, degradation still occurs even with the existence of geoconservation initiatives. Normally, the loss of geodiversity features is irreversible and protection measures are only applied in order to try to stop further damage. However, should this be imperative to all types of geosites? This question emerged with the case of the restoration of the Alto Vez geosite in the Peneda Mountain, one of the most remarkable fields of glacial erratic boulders in Portugal. Besides the erratic granite boulders, other relevant glacial features occur such as an U-shaped valley and moraines, justifying the inclusion of this site as one of the most important geosites in the Portuguese geoheritage inventory. Despite its scientific relevance, it is located just outside the contiguous Peneda-Gerês National Park, the most important protected area in Portugal. This national park was founded in 1971 and its limits were defined before the scientific discovery of these relevant glacial features. In 2012, a horseracing track was constructed in the geosite by the local village administration, with the removal of erratic boulders from their original place, affecting the natural landscape and the geosite’s integrity. After a claim made by a citizen, legal and administrative actions made by the Portuguese Institute of Nature Conservation and Forests and by the municipal authorities, have resulted in the closure of the racing track, an assessment of the degradation and definition of a strategy to reduce the damages. Under our supervision, a restoration plan was conducted in 2017. Aerial photos captured by unmanned aerial vehicles were used, together with dGPS and GIS procedures. The initial topography was restored using earthmoving machinery and the buried erratic boulders were identified and carefully relocated to their original position. A management plan of the geosite is being produced in order to protect it more efficiently through a statutory designation and to promote its tourism and educational uses. This case-study shows that a well-informed society is essential to help authorities to protect geoheritage and that a geosite restoration is possible when the main geodiversity features are not yet fully destroyed