Oxygen Isotopic Imaging of Refractory Inclusions from the Miller Range (MIL) 090019 CO3 Chondrite: A Perovskite Perspective

Calcium-Aluminum-rich Inclusions (CAIs) in primitive meteorites are the first solids to condense in the Solar System. The oxygen isotopic compositions recorded in various mineral components of CAIs provide clues about their origins and post-formation histories, recording processes such as condensation, melting, nebular alteration, and fluidrock reactions on the parent body. MIL 090019 is similar to some rare carbonaceous chondrites such as Acfer 094, DOM 08004/6 and ALH 77303 that contain high abundances of a variety of refractory inclusions. This provides an opportunity to study the oxygen isotopic record of different types of refractory inclusions within the same meteorite. We analyzed CAIs specifically targeting primary minerals that are direct nebular condensates, such as corundum and perovskite, with the goal of gaining insights into the O isotopic composition of the nebular gas(es) from which these CAIs condensed. As MIL 090019 is a classified as CO3.1, it shows some signs of thermal metamorphism, compared to the more primitive CO3 meteorites (e.g., DOM 08004/06). A second goal of this study is to search for evidence of nebular processes in phases such as perovskite and melilite that are susceptible to parent body alteration to varying degrees. We analyzed the oxygen isotopic compositions of various CAIs from the MIL 090019 CO3 carbonaceous chondrite by ion imaging using the NanoSIMS 50L (Nano Secondary Ion Mass Spectrometer) at JSC following methods described in. An advantage of ion imaging over traditional spot analyses is that it provides spatial context to the oxygen isotopic data. This work builds on previously reported oxygen isotopic composition of two other CAIs (CAI-44 and CAI-E2) from the same meteorite thin section

Isotopic and Microstructural Analyses of Opaque Mineral Assemblages and Their Alteration Products Hosted in a Refractory Inclusion

Calcium-aluminum-rich inclusions (CAIs) hosted in primitive meteorites are the oldest solids formed in the Solar System. Some CAIs contain metal nuggets that are complex assemblages of Fe-Ni alloys, along with rare ultra-refractory metals such as platinum group elements (PGEs), and their alteration products such as magnetite, sulfides, and phosphates. Three possible mechanisms proposed to explain the origin of these metal nuggets include condensation in circumstellar settings, condensation in the solar nebula within the CAI-forming region, or crystallization from immiscible metal-silicate melt. However, secondary alteration processes may have also affected some of these assemblages. Additionally, similar metal assemblages observed in chondrules and chondritic matrix indicate that all of these metal nuggets could share common high-temperature origins. These metal assemblages record early Solar System conditions that are reflected in their distinctive chemical composition, mineralogy and microstructures. Here we report a detailed mineralogical, microstructural and oxygen isotopic study of one such metal assemblage hosted in a CAI to understand the physical and chemical settings in which it formed

Attitudes of College Students towards Agriculture, Food and the Role of Government

In 2002 and 2007 we surveyed Agribusiness students’ attitudes about agriculture, farming, food and agricultural policies. Responses were analyzed by year and student characteristics including farm background, citizenship and gender. Citizenship was a significant variable explaining differences in agreement with statements. Year and interactions with year were not significant.agricultural policy, farming, logistic regression, student attitudes, Agricultural and Food Policy, Teaching/Communication/Extension/Profession, A13, A22, C42, Q18,

DISABILITY & QUALITY OF LIFE OF CHILDREN WITH SPECIAL NEEDS: AN INTERPRETATIVE PHENOMOLOGICAL ANALYSIS

Children with disabilities are one of the marginalized and debarred groups of children who experiencing extensive violations of their rights but every individual have a right to live freely and with dignity on the earth including the special need children. It is the disability which keeps such inequality apart from the fundamental human rights. In order to make all children including children with special needs enjoy their basic rights as envisaged in the UN’s Universal Declaration of Human Rights, and lead a dignified, physically and mentally healthy and happy life, we have to improve their Quality of Life (QoL). Assessment of QoL is important because it gives voice to children. The present study focused on the QoL of children living with a disability. The study was conducted on special need children studying in special school of Varanasi city in India and Northwest Copenhagen city of Denmark. The method used is the phenomological method which involves participant observation with the help of detailed field notes and interviews. The study revealed that disability is lived and experienced in a very personal way by the children with special needs and disability tends to adapt a better QoL to overcome lack of access and failure.  Article visualizations

Capturing an Evolving Nebular Environment: A Petrographic and Geochemical Study of a Type A, B & C CAI

Calcium, Aluminum-rich Inclusions (CAIs) were the first formed solids in our Solar System, with mineral assemblages reflecting the first phases predicted to condense out of a hot nebular gas of Solar composition. Geochemical, textural and crystallographic information in CAIs can be used to constrain the temperature, pressure, and composition (e.g., oxygen fugacity) of the gaseous reservoir(s) from which they formed, as well as any secondary (nebular and parent body) processes they underwent. Coordinated geochemical and textural analyses provide information on nebular conditions (i.e., astrophysical environments and dynamics of nebular gas reservoirs) in which these CAIs formed. In order to better understand the evolution of nebular reservoirs at the time of CAI formation, we analyzed a Type A, B and C CAI using Electron Probe Micro-Analyzer (EPMA) and Electron BackScatter Diffraction (EBSD) at NASA Johnson Space Center (JSC)

Improved Techniques for the Conditional Generative Augmentation of Clinical Audio Data

Data augmentation is a valuable tool for the design of deep learning systems to overcome data limitations and stabilize the training process. Especially in the medical domain, where the collection of large-scale data sets is challenging and expensive due to limited access to patient data, relevant environments, as well as strict regulations, community-curated large-scale public datasets, pretrained models, and advanced data augmentation methods are the main factors for developing reliable systems to improve patient care. However, for the development of medical acoustic sensing systems, an emerging field of research, the community lacks large-scale publicly available data sets and pretrained models. To address the problem of limited data, we propose a conditional generative adversarial neural network-based augmentation method which is able to synthesize mel spectrograms from a learned data distribution of a source data set. In contrast to previously proposed fully convolutional models, the proposed model implements residual Squeeze and Excitation modules in the generator architecture. We show that our method outperforms all classical audio augmentation techniques and previously published generative methods in terms of generated sample quality and a performance improvement of 2.84% of Macro F1-Score for a classifier trained on the augmented data set, an enhancement of 1.14% in relation to previous work. By analyzing the correlation of intermediate feature spaces, we show that the residual Squeeze and Excitation modules help the model to reduce redundancy in the latent features. Therefore, the proposed model advances the state-of-the-art in the augmentation of clinical audio data and improves the data bottleneck for the design of clinical acoustic sensing systems

Secondary electron yield of emissive materials for large-area micro-channel plate detectors: surface composition and film thickness dependencies

The ongoing development of Atomic Layer Deposition (ALD) enables the use of relatively inexpensive and robust borosilicate micro-channel substrates for use as Micro-Channel Plates (MCPs). The surfaces of the channels in these glass plates are functionalized to control the conductivity as well as the Secondary Electron Yield (SEY). The extensive SEY data found in literature show significant variation for a given material depending on the apparatus, the measurement procedure, and the sample preparation and handling. We present systematic studies on the effects of film thickness and surface chemical composition on SEY. We have modified an existing ultra-high vacuum apparatus containing X-ray and Ultraviolet Photoelectron Spectrometers (XPS and UPS, respectively) by adding a modified Low Energy Electron Diffraction (LEED) module for SEY measurements. With these tools, we have characterized the secondary electron emissive properties for MgO, Al2O3, and multilayered MgO/TiO2 structures to serve as electron emissive layers in the channels of the MCPs

Quasiperiodic spin-orbit motion and spin tunes in storage rings

We present an in-depth analysis of the concept of spin precession frequency for integrable orbital motion in storage rings. Spin motion on the periodic closed orbit of a storage ring can be analyzed in terms of the Floquet theorem for equations of motion with periodic parameters and a spin precession frequency emerges in a Floquet exponent as an additional frequency of the system. To define a spin precession frequency on nonperiodic synchro-betatron orbits we exploit the important concept of quasiperiodicity. This allows a generalization of the Floquet theorem so that a spin precession frequency can be defined in this case too. This frequency appears in a Floquet-like exponent as an additional frequency in the system in analogy with the case of motion on the closed orbit. These circumstances lead naturally to the definition of the uniform precession rate and a definition of spin tune. A spin tune is a uniform precession rate obtained when certain conditions are fulfilled. Having defined spin tune we define spin-orbit resonance on synchro--betatron orbits and examine its consequences. We give conditions for the existence of uniform precession rates and spin tunes (e.g. where small divisors are controlled by applying a Diophantine condition) and illustrate the various aspects of our description with several examples. The formalism also suggests the use of spectral analysis to ``measure'' spin tune during computer simulations of spin motion on synchro-betatron orbits.Comment: 62 pages, 1 figure. A slight extension of the published versio

Isoscalar resonances with J^{PC}=1^{--} in e^+e^-annihilation

The analysis of the vector isoscalar excitations in the energy range between 1 and 2 GeV of the $e^+e^-$ annihilation is presented for the final states $\pi^+\pi^-\pi^0$, $\omega\pi^+\pi^-$, $K^+K^-$, $K^0_SK^\pm\pi^\mp$ and $K^{\ast0}K^-\pi^++ c.c$. The effects of both the resonance mixing and the successive opening of multiparticle channels, with the energy dependent partial widths, are taken into account. The work extends our previous analysis hep-ph/9609216 of the vector isovector excitations and is aimed to compare the existing data with the predictions of the $q\bar q$ model. It is shown that this hypothesis does not contradict the data.Comment: 16 pages, revtex, 6 ps figures. Clarifying remarks, a table, and references are added. Accepted in Phys. Rev.

The anticancer activity of an air-stable Pd(i)-NHC (NHC = N-heterocyclic carbene) dimer

A new dinuclear Pd(i) complex coordinating two bis(NHC) ligands revealed an unsuspected stability despite the unsaturation of the two metal centres. Even more surprisingly, the compound showed high and selective antiproliferative activity against different cancer cell lines and ovarian cancer tumoroids, and the mechanism of action was different from that of cisplatin