The role of boron and fluids in high temperature, shallow level metamorphism of the Chugach Metamorphic Complex, Alaska

The possible role of boron (B) involvement in granite equilibria and generation of melts during crustal metamorphism has been a focus of speculation in recent literature. Most of the evidence for such involvement derives from experimental data which implies that the addition of B will lower the temperature of the granite solidus. Also the presence of tourmaline has a minor effect on the temperature of the solidus. Further indirect evidence that B may be involved in partial melting processes is the observation that granulites are commonly depleted in B, whereas the B content of low grade metapelites can be high (up to 2000 ppm). Researchers' measurements of the whole-rock B contents of granulites from the Madras region, India are low, ranging from 0.4 to 2.6 ppm. Ahmad and Wilson suggest that B was mobilized in the fluid phase during granulite facies metamorphism of the Broken Hill Complex, Australia. Thus, it appears that during the amphibolite to granulite transition, B is systematically lost from metasediments. The B that is released will probably partition into the vapor phase and/or melt phase. Preliminary measurements imply that the boron content of rocks in the Chugach Metamorphic Complex is not sufficient to influence the processes of partial melting at low pressures

Jadeitite from Guatemala : new observations and distinctions among multiple occurrences

In Guatemala, jadeitite occurs as blocks in serpentinite mélange in distinct settings on opposite sides of the Motagua fault. Jadeitites north of the Motagua fault are associated with eclogites, blueschists, and garnet amphibolites and distributed over a 200km E-W area. Omphacitite, omphacite - taramite metabasite, albitite, and phengite rock are found with jadeitite. The assemblages indicate formation at 6-12kbar and 300-400°C, however jadeite - omphacite pairs yield T from ~200 to >500ºC for jadeite crystallization. Jadeitites south of the Motagua fault are sourced from three separate fault slices of serpentinite in Jalapa and Zacapa departments and are distinctive: 1) Jadeitite near Carrizal Grande is found in serpentinite with lawsonite eclogites, variably altered to blueschist, and rarely in schists. A large jadeite - omphacite gap and lawsonite suggests T=300-400°C, but at high P as indicated by the presence of quartz: P>12-20kbar. Lawsonite eclogites (P=20-25kbar, T=350-450°C) occur with these jadeitites. 2) At La Ceiba, jadeitites coexist with omphacite blueschists and contain late-stage veins of quartz, diopside, cymrite, actinolite, titanite and vesuvianite. A large jadeite - omphacite gap suggests 300-400°C, but at lower P as indicated by quartz + albite: P=10-14kbar. 3) At La Ensenada jade i tites occur with lawsonite-glaucophane blueschists and chloritite. It is a fine-grained jadeite-pumpellyite rock, intensely deformed and veined with grossular, omphacite, albite and titanite, but no quartz. A large jadeite-omphacite gap and pumpellyite suggest ~200-~300°C at lower P consistent with primary albite: P=6-9kbar. The silicates contain little iron

Management of incidentally detected heart murmurs in dogs and cats

A dog or a cat has an incidentally detected heart murmur if the murmur is an unexpected discovery during a veterinary consultation that was not initially focused on the cardiovascular system. This document presents approaches for managing dogs and cats that have incidentally-detected heart murmurs, with an emphasis on murmur characteristics, signalment profiling, and multifactorial decision-making to choose an optimal course for a given patient

Performance evaluation of cetacean species distribution models developed using generalized additive models and boosted regression trees

Species distribution models (SDMs) are important management tools for highly mobile marine species because they provide spatially and temporally explicit information on animal distribution. Two prevalent modeling frameworks used to develop SDMs for marine species are generalized additive models (GAMs) and boosted regression trees (BRTs), but comparative studies have rarely been conducted; most rely on presence-only data; and few have explored how features such as species distribution characteristics affect model performance. Since the majority of marine species BRTs have been used to predict habitat suitability, we first compared BRTs to GAMs that used presence/absence as the response variable. We then compared results from these habitat suitability models to GAMs that predict species density (animals per km2) because density models built with a subset of the data used here have previously received extensive validation. We compared both the explanatory power (i.e., model goodness of fit) and predictive power (i.e., performance on a novel dataset) of the GAMs and BRTs for a taxonomically diverse suite of cetacean species using a robust set of systematic survey data (1991–2014) within the California Current Ecosystem. Both BRTs and GAMs were successful at describing overall distribution patterns throughout the study area for the majority of species considered, but when predicting on novel data, the density GAMs exhibited substantially greater predictive power than both the presence/absence GAMs and BRTs, likely due to both the different response variables and fitting algorithms. Our results provide an improved understanding of some of the strengths and limitations of models developed using these two methods. These results can be used by modelers developing SDMs and resource managers tasked with the spatial management of marine species to determine the best modeling technique for their question of interest

Performance Evaluation of Cetacean Species Distribution Models Developed Using Generalized Additive Models and Boosted Regression Trees

Species distribution models (SDMs) are important management tools for highly mobile marine species because they provide spatially and temporally explicit information on animal distribution. Two prevalent modeling frameworks used to develop SDMs for marine species are generalized additive models (GAMs) and boosted regression trees (BRTs), but comparative studies have rarely been conducted; most rely on presence-only data; and few have explored how features such as species distribution characteristics affect model performance. Since the majority of marine species BRTs have been used to predict habitat suitability, we first compared BRTs to GAMs that used presence/absence as the response variable. We then compared results from these habitat suitability models to GAMs that predict species density (animals per km2) because density models built with a subset of the data used here have previously received extensive validation. We compared both the explanatory power (i.e., model goodness of fit) and predictive power (i.e., performance on a novel dataset) of the GAMs and BRTs for a taxonomically diverse suite of cetacean species using a robust set of systematic survey data (1991–2014) within the California Current Ecosystem. Both BRTs and GAMs were successful at describing overall distribution patterns throughout the study area for the majority of species considered, but when predicting on novel data, the density GAMs exhibited substantially greater predictive power than both the presence/absence GAMs and BRTs, likely due to both the different response variables and fitting algorithms. Our results provide an improved understanding of some of the strengths and limitations of models developed using these two methods. These results can be used by modelers developing SDMs and resource managers tasked with the spatial management of marine species to determine the best modeling technique for their question of interest

Numerical Renormalization Group Study of Kondo Effect in Unconventional Superconductors

Orbital degrees of freedom of a Cooper pair play an important role in the unconventional superconductivity. To elucidate the orbital effect in the Kondo problem, we investigated a single magnetic impurity coupled to Cooper pairs with a $p_x +i p_y$ ($d_{x^2-y^2}+id_{xy}$) symmetry using the numerical renormalization group method. It is found that the ground state is always a spin doublet. The analytical solution for the strong coupling limit explicitly shows that the orbital dynamics of the Cooper pair generates the spin 1/2 of the ground state.Comment: 4 pages, 2 figures, JPSJ.sty, to be published in J. Phys. Soc. Jpn. 70 (2001) No. 1

CFAP54 is required for proper ciliary motility and assembly of the central pair apparatus in mice.

Motile cilia and flagella play critical roles in fluid clearance and cell motility, and dysfunction commonly results in the pediatric syndrome primary ciliary dyskinesia (PCD). CFAP221, also known as PCDP1, is required for ciliary and flagellar function in mice and Chlamydomonas reinhardtii, where it localizes to the C1d projection of the central microtubule apparatus and functions in a complex that regulates flagellar motility in a calcium-dependent manner. We demonstrate that the genes encoding the mouse homologues of the other C. reinhardtii C1d complex members are primarily expressed in motile ciliated tissues, suggesting a conserved function in mammalian motile cilia. The requirement for one of these C1d complex members, CFAP54, was identified in a mouse line with a gene-trapped allele. Homozygous mice have PCD characterized by hydrocephalus, male infertility, and mucus accumulation. The infertility results from defects in spermatogenesis. Motile cilia have a structural defect in the C1d projection, indicating that the C1d assembly mechanism requires CFAP54. This structural defect results in decreased ciliary beat frequency and perturbed cilia-driven flow. This study identifies a critical role for CFAP54 in proper assembly and function of mammalian cilia and flagella and establishes the gene-trapped allele as a new model of PCD

EquiFACS: the Equine Facial Action Coding System

Although previous studies of horses have investigated their facial expressions in specific contexts, e.g. pain, until now there has been no methodology available that documents all the possible facial movements of the horse and provides a way to record all potential facial configurations. This is essential for an objective description of horse facial expressions across a range of contexts that reflect different emotional states. Facial Action Coding Systems (FACS) provide a systematic methodology of identifying and coding facial expressions on the basis of underlying facial musculature and muscle movement. FACS are anatomically based and document all possible facial movements rather than a configuration of movements associated with a particular situation. Consequently, FACS can be applied as a tool for a wide range of research questions. We developed FACS for the domestic horse (Equus caballus) through anatomical investigation of the underlying musculature and subsequent analysis of naturally occurring behaviour captured on high quality video. Discrete facial movements were identified and described in terms of the underlying muscle contractions, in correspondence with previous FACS systems. The reliability of others to be able to learn this system (EquiFACS) and consistently code behavioural sequences was high—and this included people with no previous experience of horses. A wide range of facial movements were identified, including many that are also seen in primates and other domestic animals (dogs and cats). EquiFACS provides a method that can now be used to document the facial movements associated with different social contexts and thus to address questions relevant to understanding social cognition and comparative psychology, as well as informing current veterinary and animal welfare practices

Quantum impurity dynamics in two-dimensional antiferromagnets and superconductors

We present the universal theory of arbitrary, localized impurities in a confining paramagnetic state of two-dimensional antiferromagnets with global SU(2) spin symmetry. The energy gap of the host antiferromagnet to spin-1 excitations, \Delta, is assumed to be significantly smaller than a typical nearest neighbor exchange. In the absence of impurities, it was argued in earlier work (Chubukov et al. cond-mat/9304046) that the low-temperature quantum dynamics is universally and completely determined by the values of \Delta and a spin-wave velocity c. Here we establish the remarkable fact that no additional parameters are necessary for an antiferromagnet with a dilute concentration of impurities, n_{imp} - each impurity is completely characterized by a integer/half-odd-integer valued spin, S, which measures the net uncompensated Berry phase due to spin precession in its vicinity. We compute the impurity-induced damping of the spin-1 collective mode of the antiferromagnet: the damping occurs on an energy scale \Gamma= n_{imp} (\hbar c)^2/\Delta, and we predict a universal, asymmetric lineshape for the collective mode peak. We argue that, under suitable conditions, our results apply unchanged (or in some cases, with minor modifications) to d-wave superconductors, and compare them to recent neutron scattering experiments on YBCO by Fong et al. (cond-mat/9812047). We also describe the universal evolution of numerous measurable correlations as the host antiferromagnet undergoes a quantum phase transition to a Neel ordered state.Comment: 36 pages, 12 figures; added reference

Order and quantum phase transitions in the cuprate superconductors

It is now widely accepted that the cuprate superconductors are characterized by the same long-range order as that present in the Bardeen-Cooper-Schrieffer (BCS) theory: that associated with the condensation of Cooper pairs. We argue that many physical properties of the cuprates require interplay with additional order parameters associated with a proximate Mott insulator. We review a classification of Mott insulators in two dimensions, and contend that the experimental evidence so far shows that the class appropriate to the cuprates has collinear spin correlations, bond order, and confinement of neutral, spin S=1/2 excitations. Proximity to second-order quantum phase transitions associated with these orders, and with the pairing order of BCS, has led to systematic predictions for many physical properties. We use this context to review the results of recent neutron scattering, fluxoid detection, nuclear magnetic resonance, and scanning tunnelling microscopy experiments.Comment: 20 pages, 13 figures, non-technical review article; some technical details in the companion review cond-mat/0211027; (v3) added refs; (v4) numerous improvements thanks to the referees, to appear in Reviews of Modern Physics; (v6) final version as publishe