Depositional age and exhumation of Tethyan Sedimentary rocks intruded by Oligo-Miocene granite

Abstract HKT-ISTP 2013 A

Garnets from Val d’Ala Rodingites, Piedmont, Italy: An Investigation of Their Gemological, Spectroscopic and Crystal Chemical Properties

In Val d\u2019Ala (Piedmont,Western Alps, Italy), the more interesting rocks for the mineralogical research are represented by rodingites (rich in mineralized veins and fractures) associated with serpentinites in the eclogitized oceanic crust of Piemonte Zone, south of Gran Paradiso Massif. Among the vein-filling minerals, garnets are the most appreciated as mineral specimens and, in less degree despite their vivid and rich colors, for their potential as gem-quality materials. This study provides a complete gemological characterization of five faceted samples and others new information by means of Synchrotron X-ray computed micro-tomography imaging gem features. Electron-probe microanalysis (EMPA) and laser ablation\u2013inductively coupled plasma\u2013mass spectrometry (LA\u2013ICP\u2013MS) established that the chemical composition of garnets from different localities, resulted both close to pure andradite, enriched in light rare earth elements (LREE) with a positive Eu anomaly, and grossular-andradite solid solution (grandite), enriched in heavy rare earth elements (HREE). X-ray powder diffraction analyses indicate the possible coexistence of almost pure grossular and andradite. A spectroscopic approach, commonly used with gem-like material, by Raman and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, completes the characterization of the samples. The new data on the textural and geochemical features of the grandite and andradite garnets suggest local growth processes under various chemical and oxidation conditions of metasomatic and metamorphic fluids interacting with the host-rocks. Garnets represent long-lasting mineral records of the complex geological history of the Val d\u2019Ala rodingitic dikes during their oceanic- and subduction-related metamorphic evolution

Kernel Spectral Clustering and applications

In this chapter we review the main literature related to kernel spectral clustering (KSC), an approach to clustering cast within a kernel-based optimization setting. KSC represents a least-squares support vector machine based formulation of spectral clustering described by a weighted kernel PCA objective. Just as in the classifier case, the binary clustering model is expressed by a hyperplane in a high dimensional space induced by a kernel. In addition, the multi-way clustering can be obtained by combining a set of binary decision functions via an Error Correcting Output Codes (ECOC) encoding scheme. Because of its model-based nature, the KSC method encompasses three main steps: training, validation, testing. In the validation stage model selection is performed to obtain tuning parameters, like the number of clusters present in the data. This is a major advantage compared to classical spectral clustering where the determination of the clustering parameters is unclear and relies on heuristics. Once a KSC model is trained on a small subset of the entire data, it is able to generalize well to unseen test points. Beyond the basic formulation, sparse KSC algorithms based on the Incomplete Cholesky Decomposition (ICD) and $L_0$, $L_1, L_0 + L_1$, Group Lasso regularization are reviewed. In that respect, we show how it is possible to handle large scale data. Also, two possible ways to perform hierarchical clustering and a soft clustering method are presented. Finally, real-world applications such as image segmentation, power load time-series clustering, document clustering and big data learning are considered.Comment: chapter contribution to the book "Unsupervised Learning Algorithms

Gem-Quality Tourmaline from LCT Pegmatite in Adamello Massif, Central Southern Alps, Italy: An Investigation of Its Mineralogy, Crystallography and 3D Inclusions

In the early 2000s, an exceptional discovery of gem-quality multi-coloured tourmalines, hosted in Litium-Cesium-Tantalum (LCT) pegmatites, was made in the Adamello Massif, Italy. Gem-quality tourmalines had never been found before in the Alps, and this new pegmatitic deposit is of particular interest and worthy of a detailed characterization. We studied a suite of faceted samples by classical gemmological methods, and fragments were studied with Synchrotron X-ray computed micro-tomography, which evidenced the occurrence of inclusions, cracks and voids. Electron Microprobe combined with Laser Ablation analyses were performed to determine major, minor and trace element contents. Selected samples were analysed by single crystal X-ray diffraction method. The specimens range in colour from colourless to yellow, pink, orange, light blue, green, amber, brownish-pink, purple and black. Chemically, the tourmalines range from fluor-elbaite to fluor-liddicoatite and rossmanite: these chemical changes occur in the same sample and affect the colour. Rare Earth Elements (REE) vary from 30 to 130 ppm with steep Light Rare Earth Elemts (LREE)-enriched patterns and a negative Eu-anomaly. Structural data confirmed the elbaitic composition and showed that high manganese content may induce the local static disorder at the O(1) anion site, coordinating the Y cation sites occupied, on average, by Li, Al and Mn2+ in equal proportions, confirming previous findings. In addition to the gemmological value, the crystal-chemical studies of tourmalines are unanimously considered to be a sensitive recorder of the geological processes leading to their formation, and therefore, this study may contribute to understanding the evolution of the pegmatites related to the intrusion of the Adamello pluton

Failure of a patient-centered intervention to substantially increase the identification and referral for-treatment of ambulatory emergency department patients with occult psychiatric conditions: a randomized trial [ISRCTN61514736]

BACKGROUND: We previously demonstrated that a computerized psychiatric screening interview (the PRIME-MD) can be used in the Emergency Department (ED) waiting room to identify patients with mental illness. In that trial, however, informing the ED physician of the PRIME-MD results did not increase the frequency of psychiatric diagnosis, consultation or referral. We conducted this study to determine whether telling the patient and physician the PRIME-MD result would result in the majority of PRIME-MD-diagnosed patients being directed toward treatment for their mental illness. METHODS: In this single-site RCT, consenting patients with non-specific somatic chief complaints (e.g., fatigue, back pain, etc.) completed the computerized PRIME-MD in the waiting room and were randomly assigned to one of three groups: patient and physician told PRIME-MD results, patient told PRIME-MD results, and neither told PRIME-MD results. The main outcome measure was the percentage of patients with a PRIME-MD diagnosis who received a psychiatric consultation or referral from the ED. RESULTS: 183 (5% of all ED patients) were approached. 123 eligible patients consented to participate, completed the PRIME-MD and were randomized. 95 patients had outcomes recorded. 51 (54%) had a PRIME-MD diagnosis and 8 (16%) of them were given a psychiatric consultation or referral in the ED. While the frequency of consultation or referral increased as the intervention's intensity increased (tell neither = 11% (1/9), tell patient 15% (3/20), tell patient and physician 18% (4/22)), no group came close to the 50% threshold we sought. For this reason, we stopped the trial after an interim analysis. CONCLUSION: Patients willingly completed the PRIME-MD and 54% had a PRIME-MD diagnosis. Unfortunately, at our institution, informing the patient (and physician) of the PRIME-MD results infrequently led to the patient being directed toward care for their psychiatric condition