Chemically sector-zoned garnets in the metapelitic rocks of the Silgará Formation in the central Santander Massif, colombian andes: occurrence and growth history

Almandine-rich garnet in the Silgará Formation metapelitic rocks in the central Santander Massif usually shows concentric normal chemical zoning. However, different types of garnet zoning have been reported, including chemically sector-zoned garnet, which is described here. Recent studies reveal additional discoveries of this type of zoning in different localities. Textural sector-zoned garnets have been observed in the staurolite-kyanite metamorphic zone of the Silgará Formation. They are generally fine-grained (0.25-2.00 mm in diameter), and occur in quartz-rich bands with other textural types of garnet (skeletal and poikiloblastic). The study of the chemically sector-zoned garnet indicates that it has grown in the latest stage of the Silgará Formation metamorphism, during the emplacement of orthogneiss masses. Studies on garnet from the Silgará Formation pelitic rocks have shown the importance of this as a key piece for interpretation of the tectono-metamorphic history of this metamorphic unit.El granate tipo almandino en las rocas metapelíticas de la Formación Silgará en la región central del Macizo de Santander usualmente muestra zonación química concéntrica normal. Sin embargo, se han reportado diferentes tipos de zonación en el granate, incluyendo el granate químicamente sector-zonado, el cual es descrito aquí. Estudios recientes revelan descubrimientos adicionales de este tipo de zonación en diferentes localidades. Los granates que exhiben zonación sectorial textural han sido observados en la zona metamórfica de la estaurolitacianita de la Formación Silgará. Estos son generalmente de grano fino (0.25-2.00 mm de diámetro), y ocurren en bandas ricas en cuarzo junto con otros tipos texturales de granate (esqueletal y poiquiloblástico). El estudio del granate químicamente sector-zonado indica que este creció en la etapa tardía de metamorfismo de la Formación Silgará, durante el emplazamiento de masas de ortoneis. Estudios sobre el granate en las rocas pelíticas de la Formación Silgará han mostrado su importancia como pieza clave en la interpretación de la historia tectonometamórfica de esta unidad metamórfica. &nbsp

Chemically sector-zoned garnets in the metapelitic rocks of the Silgará Formation in the central Santander Massif, colombian andes: occurrence and growth history

Almandine-rich garnet in the Silgará Formation metapelitic rocks in the central Santander Massif usually shows concentric normal chemical zoning. However, different types of garnet zoning have been reported, including chemically sector-zoned garnet, which is described here. Recent studies reveal additional discoveries of this type of zoning in different localities. Textural sector-zoned garnets have been observed in the staurolite-kyanite metamorphic zone of the Silgará Formation. They are generally fine-grained (0.25-2.00 mm in diameter), and occur in quartz-rich bands with other textural types of garnet (skeletal and poikiloblastic). The study of the chemically sector-zoned garnet indicates that it has grown in the latest stage of the Silgará Formation metamorphism, during the emplacement of orthogneiss masses. Studies on garnet from the Silgará Formation pelitic rocks have shown the importance of this as a key piece for interpretation of the tectono-metamorphic history of this metamorphic unit.El granate tipo almandino en las rocas metapelíticas de la Formación Silgará en la región central del Macizo de Santander usualmente muestra zonación química concéntrica normal. Sin embargo, se han reportado diferentes tipos de zonación en el granate, incluyendo el granate químicamente sector-zonado, el cual es descrito aquí. Estudios recientes revelan descubrimientos adicionales de este tipo de zonación en diferentes localidades. Los granates que exhiben zonación sectorial textural han sido observados en la zona metamórfica de la estaurolitacianita de la Formación Silgará. Estos son generalmente de grano fino (0.25-2.00 mm de diámetro), y ocurren en bandas ricas en cuarzo junto con otros tipos texturales de granate (esqueletal y poiquiloblástico). El estudio del granate químicamente sector-zonado indica que este creció en la etapa tardía de metamorfismo de la Formación Silgará, durante el emplazamiento de masas de ortoneis. Estudios sobre el granate en las rocas pelíticas de la Formación Silgará han mostrado su importancia como pieza clave en la interpretación de la historia tectonometamórfica de esta unidad metamórfica. &nbsp

Quantum Computing and Quantum Simulation with Group-II Atoms

Recent experimental progress in controlling neutral group-II atoms for optical clocks, and in the production of degenerate gases with group-II atoms has given rise to novel opportunities to address challenges in quantum computing and quantum simulation. In these systems, it is possible to encode qubits in nuclear spin states, which are decoupled from the electronic state in the $^1$S$_0$ ground state and the long-lived $^3$P$_0$ metastable state on the clock transition. This leads to quantum computing scenarios where qubits are stored in long lived nuclear spin states, while electronic states can be accessed independently, for cooling of the atoms, as well as manipulation and readout of the qubits. The high nuclear spin in some fermionic isotopes also offers opportunities for the encoding of multiple qubits on a single atom, as well as providing an opportunity for studying many-body physics in systems with a high spin symmetry. Here we review recent experimental and theoretical progress in these areas, and summarise the advantages and challenges for quantum computing and quantum simulation with group-II atoms.Comment: 11 pages, 7 figures, review for special issue of "Quantum Information Processing" on "Quantum Information with Neutral Particles

1,25(OH)2D3 Alters Growth Plate Maturation and Bone Architecture in Young Rats with Normal Renal Function

Whereas detrimental effects of vitamin D deficiency are known over century, the effects of vitamin D receptor activation by 1,25(OH)2D3, the principal hormonal form of vitamin D, on the growing bone and its growth plate are less clear. Currently, 1,25(OH)2D3 is used in pediatric patients with chronic kidney disease and mineral and bone disorder (CKD-MBD) and is strongly associated with growth retardation. Here, we investigate the effect of 1,25(OH)2D3 treatment on bone development in normal young rats, unrelated to renal insufficiency. Young rats received daily i.p. injections of 1 µg/kg 1,25(OH)2D3 for one week, or intermittent 3 µg/kg 1,25(OH)2D3 for one month. Histological analysis revealed narrower tibial growth plates, predominantly in the hypertrophic zone of 1,25(OH)2D3-treated animals in both experimental protocols. This phenotype was supported by narrower distribution of aggrecan, collagens II and X mRNA, shown by in situ hybridization. Concomitant with altered chondrocyte maturation, 1,25(OH)2D3 increased chondrocyte proliferation and apoptosis in terminal hypertrophic cells. In vitro treatment of the chondrocytic cell line ATDC5 with 1,25(OH)2D3 lowered differentiation and increased proliferation dose and time-dependently. Micro-CT analysis of femurs from 1-week 1,25(OH)2D3-treated group revealed reduced cortical thickness, elevated cortical porosity, and higher trabecular number and thickness. 1-month administration resulted in a similar cortical phenotype but without effect on trabecular bone. Evaluation of fluorochrome binding with confocal microscopy revealed inhibiting effects of 1,25(OH)2D3 on intracortical bone formation. This study shows negative effects of 1,25(OH)2D3 on growth plate and bone which may contribute to the exacerbation of MBD in the CKD pediatric patients

Outcomes of Brood Parasite–Host Interactions Mediated by Egg Matching: Common Cuckoos Cuculus canorus versus Fringilla Finches

Antagonistic species often interact via matching of phenotypes, and interactions between brood parasitic common cuckoos (Cuculus canorus) and their hosts constitute classic examples. The outcome of a parasitic event is often determined by the match between host and cuckoo eggs, giving rise to potentially strong associations between fitness and egg phenotype. Yet, empirical efforts aiming to document and understand the resulting evolutionary outcomes are in short supply.We used avian color space models to analyze patterns of egg color variation within and between the cuckoo and two closely related hosts, the nomadic brambling (Fringilla montifringilla) and the site fidelic chaffinch (F. coelebs). We found that there is pronounced opportunity for disruptive selection on brambling egg coloration. The corresponding cuckoo host race has evolved egg colors that maximize fitness in both sympatric and allopatric brambling populations. By contrast, the chaffinch has a more bimodal egg color distribution consistent with the evolutionary direction predicted for the brambling. Whereas the brambling and its cuckoo host race show little geographical variation in their egg color distributions, the chaffinch's distribution becomes increasingly dissimilar to the brambling's distribution towards the core area of the brambling cuckoo host race.High rates of brambling gene flow is likely to cool down coevolutionary hot spots by cancelling out the selection imposed by a patchily distributed cuckoo host race, thereby promoting a matching equilibrium. By contrast, the site fidelic chaffinch is more likely to respond to selection from adapting cuckoos, resulting in a markedly more bimodal egg color distribution. The geographic variation in the chaffinch's egg color distribution could reflect a historical gradient in parasitism pressure. Finally, marked cuckoo egg polymorphisms are unlikely to evolve in these systems unless the hosts evolve even more exquisite egg recognition capabilities than currently possessed

Fabrication of Pt/Ru Nanoparticle Pair Arrays with Controlled Separation and their Electrocatalytic Properties

Aiming at the investigation of spillover and transport effects in electrocatalytic reactions on bimetallic catalyst electrodes, we have prepared novel, nanostructured electrodes consisting of arrays of homogeneously distributed pairs of Pt and Ru nanodisks of uniform size and with controlled separation on planar glassy carbon substrates. The nanodisk arrays (disk diameter approximate to 60 nm) were fabricated by hole-mask colloidal lithography; the separation between pairs of Pt and Ru disks was varied from -25 nm (overlapping) via +25 nm to +50 nm. Morphology and (surface) composition of the Pt/Ru nanodisk arrays Were characterized by scanning electron microscopy, energy dispersive X-ray analysis, and X-ray Photoelectron spectroscopy, the electrochemical/electrocatalytic properties were explored by cyclic voltammetry, COad monolayer oxidation ("COad stripping"), and potentiodynamic hydrogen oxidation. Detailed analysis of the 2 COad oxidation peaks revealed that on all bimetallic pairs these cannot be reproduced by superposition of the peaks obtained on electrodes with Pt/Pt or Ru/Ru pairs, pointing to effective Pt-Ru interactions even between rather distant pairs (50 nm). Possible reasons for this observation and its relevance for the understanding of previous reports of highly active catalysts with separate Pt and Ru nanoparticles are discussed. The results clearly demonstrate that this preparation method is perfectly suited for fabrication of planar model electrodes with well-defined arrays of bimetallic nanodisk pairs, which opens up new possibilities for model studies of electrochemical/electrocatalytic reactions

Identifying characteristic features of the retinal and choroidal vasculature in choroideremia using optical coherence tomography angiography

PURPOSE: Using optical coherence tomography angiography (OCTA) to investigate the area with flow in the superficial retinal vessel network (SVRN) and choriocapillaris (CC) layer among male subjects with choroideremia (CHM), female carriers, and normal controls to identify vascular changes. PATIENTS AND METHODS: Images of SRVN and CC layer were acquired in 9 affected males, 5 female carriers, and 14 age- and gender-matched controls using the Angiovue software of the RTVue XR Avanti. RESULTS: The mean age was 33 years for affected male CHM patients (median 30 years), 46 years for female carriers (median 53 years), and 39 years for controls (median 38.5). Mean SRVN area±SD in subjects with CHM was 12.93±2.06 mm², in carrier subjects 15.36±0.60 mm², and in controls 15.30±1.35 mm² (P<0.01). The mean CC area±SD with flow was 6.97±5.26 mm² in CHM subjects, 21.65±0.17 mm² in carriers and 21.36±0.76 mm² in controls (P<0.01). SRVN and CC area with flow showed a negative correlation in CHM subjects with the age (r=−0.86; P<0.003 and r=−0.77; P<0.01, respectively). CC area with flow had a positive correlation with SRVN (r=0.83, P<0.001). Overall, visual acuity had a negative correlation with SRVN and CC area with flow (r=−0.67, P<0.001 and r=−0.57, P<0.002, respectively). CONCLUSIONS: This is the first study to highlight changes in the SRVN in CHM subjects. OCTA detected a reduced area with flow in both retinal and choroidal circulations, and may be a useful tool for monitoring natural history and disease progression in forthcoming clinical trials

C-reactive protein reference percentiles among pre-adolescent children in Europe based on the IDEFICS study population

OBJECTIVES: C-reactive protein (CRP) is involved in a wide range of diseases. It is a powerful marker for inflammatory processes used for diagnostic and monitoring purposes. We aimed to establish reference values as data on the distribution of serum CRP levels in young European children are scarce. SUBJECTS: Reference values of high-sensitivity CRP concentrations were calculated for 9855 children aged 2.0-10.9 years, stratified by age and sex. The children were recruited during the population-based European IDEFICS study (Identification and prevention of Dietary-and lifestyle-induced health Effects in Children and infantS) with 18 745 participants recruited from 2007 to 2010. RESULTS: In 44.1 % of the children, CRP values were below or equal the detection limit of 0.2 mg/l. Median CRP concentrations showed a slight negative age trend in boys and girls, whereas serum CRP values were slightly higher in girls than in boys across all age groups. CONCLUSIONS: Our population-based reference values of CRP may guide paediatric practice as elevated values may require further investigation or treatment. Therefore, the presented reference values represent a basis for clinical evaluation and for future research on risk assessment of diseases associated with increased CRP levels among children

Development of the rhopalial nervous system in Aurelia sp.1 (Cnidaria, Scyphozoa)

We examined the development of the nervous system in the rhopalium, a medusa-specific sensory structure, in Aurelia sp.1 (Cnidaria, Scyphozoa) using confocal microscopy. The rhopalial nervous system appears primarily ectodermal and contains neurons immunoreactive to antibodies against tyrosinated tubulin, taurine, GLWamide, and FMRFamide. The rhopalial nervous system develops in an ordered manner: the presumptive gravity-sensing organ, consisting of the lithocyst and the touch plate, differentiates first; the “marginal center,” which controls swimming activity, second; and finally, the ocelli, the presumptive photoreceptors. At least seven bilaterally arranged neuronal clusters consisting of sensory and ganglion cells and their neuronal processes became evident in the rhopalium during metamorphosis to the medusa stage. Our analysis provides an anatomical framework for future gene expression and experimental studies of development and functions of scyphozoan rhopalia