Natural resources of Lake Earl and Smith River Delta

The Lake Earl/Smith River Delta area is a key coastal wetland situated in northern California. The Lake and Delta have retained much of their value to wildlife and serve as an important link in a chain of such wetlands that extend southward along the Pacific Ocean from Alaska to South America. Millions of water-associated birds of the Pacific Flyway utilize these areas as feeding and resting stops along their migration paths. In California, these wetlands also serve as a significant portion of the available wintering grounds for a major share of the birds within the flyway. The Smith River is also one of the State's most productive salmon and steelhead streams. Anadromous fish produced here provide thousands of angler use days to sport fishermen and contribute substantially to the commercial fishing catch off the northern coast. Because of the importance of coastal wetlands to the fish and wildlife of California, the Department of Fish and Game has initiated a high priority statewide inventory and assessment of these wetlands. This publication is an integral part of that program. This report identifies specific resources and uses; directs attention to problems; and recommends courses of action needed to insure resource protection. It is intended as a guide for citizens, planners, administrators and other interested in the use and development of California's coastal land and waters. (132pp.

Quantum Computation and Spin Physics

A brief review is given of the physical implementation of quantum computation within spin systems or other two-state quantum systems. The importance of the controlled-NOT or quantum XOR gate as the fundamental primitive operation of quantum logic is emphasized. Recent developments in the use of quantum entanglement to built error-robust quantum states, and the simplest protocol for quantum error correction, are discussed.Comment: 21 pages, Latex, 3 eps figures, prepared for the Proceedings of the Annual MMM Meeting, November, 1996, to be published in J. Appl. Phy

Deutsch-Jozsa algorithm as a test of quantum computation

A redundancy in the existing Deutsch-Jozsa quantum algorithm is removed and a refined algorithm, which reduces the size of the register and simplifies the function evaluation, is proposed. The refined version allows a simpler analysis of the use of entanglement between the qubits in the algorithm and provides criteria for deciding when the Deutsch-Jozsa algorithm constitutes a meaningful test of quantum computation.Comment: 10 pages, 2 figures, RevTex, Approved for publication in Phys Rev

Nucleosynthetic history of elements in the Galactic disk [X/Fe]-age relations from high-precision spectroscopy

Context. The chemical composition of stars is intimately linked to the formation and evolution of the Galaxy. Aims. We aim to trace the chemical evolution of the Galactic disk through the inspection of the [X/Fe]–age relations of 24 species from C to Eu. Methods. Using high-resolution and high signal-to-noise UVES spectra of nine solar twins, we obtained precise estimates of stellar ages and chemical abundances. These determinations have been integrated with additional accurate age and abundance determinations from recent spectroscopic studies of solar twins existing in the literature, comprising superb abundances with 0.01 dex precision. Based on this data set, we outlined the [X/Fe]–age relations over a time interval of 10 Gyr. Results. We present the [X/Fe] – age relations for 24 elements (C, O, Na, Mg, Al, Si, S, K, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Y, Ba, La, Ce, Nd, and Eu). Each different class of elements showed a distinct evolution with time that relies on the different characteristics, rates, and timescales of the nucleosynthesis sites from which they are produced. The α-elements are characterized by a [X/Fe] decrease with time. Strikingly, the opposite behavior is observed for Ca. The iron-peak elements show an early [X/Fe] increase followed by a decrease towards the youngest stars. The [X/Fe] for the n-capture elements decrease with age. We also found that both [Mg/Y] and [Al/Y] are precise stellar clocks, with [Al/Y] showing the steepest dependence on age. Conclusions. Knowledge of the [X/Fe]-age relations is a gold mine from which we can achieve a great understanding of the processes that governed the formation and evolution of the Milky Way. Through the reverse engineering of these relations we will be able to put strong constraints on the nature of the stellar formation history, the SNe rates, the stellar yields, and the variety of the SNe progenitors

A simultaneous search for prompt radio emission associated with the short GRB 170112A using the all-sky imaging capability of the OVRO-LWA

We have conducted the most sensitive low frequency (below 100 MHz) search to date for prompt, low-frequency radio emission associated with short-duration gamma-ray bursts (GRBs), using the Owens Valley Radio Observatory Long Wavelength Array (OVRO-LWA). The OVRO-LWA's nearly full-hemisphere field-of-view ($\sim20$,$000$ square degrees) allows us to search for low-frequency (sub-$100$ MHz) counterparts for a large sample of the subset of GRB events for which prompt radio emission has been predicted. Following the detection of short GRB 170112A by Swift, we used all-sky OVRO-LWA images spanning one hour prior to and two hours following the GRB event to search for a transient source coincident with the position of GRB 170112A. We detect no transient source, with our most constraining $1\sigma$ flux density limit of $650~\text{mJy}$ for frequencies spanning $27~\text{MHz}-84~\text{MHz}$. We place constraints on a number of models predicting prompt, low-frequency radio emission accompanying short GRBs and their potential binary neutron star merger progenitors, and place an upper limit of $L_\text{radio}/L_\gamma \lesssim 7\times10^{-16}$ on the fraction of energy released in the prompt radio emission. These observations serve as a pilot effort for a program targeting a wider sample of both short and long GRBs with the OVRO-LWA, including bursts with confirmed redshift measurements which are critical to placing the most constraining limits on prompt radio emission models, as well as a program for the follow-up of gravitational wave compact binary coalescence events detected by advanced LIGO and Virgo.Comment: 14 pages, 5 figures, ApJ submitte

Motional Squashed States

We show that by using a feedback loop it is possible to reduce the fluctuations in one quadrature of the vibrational degree of freedom of a trapped ion below the quantum limit. The stationary state is not a proper squeezed state, but rather a ``squashed'' state, since the uncertainty in the orthogonal quadrature, which is larger than the standard quantum limit, is unaffected by the feedback action.Comment: 8 pages, 2 figures, to appear in the special Issue "Quantum Correlations and Fluctuations" of J. Opt.

Quantum strategies

We consider game theory from the perspective of quantum algorithms. Strategies in classical game theory are either pure (deterministic) or mixed (probabilistic). We introduce these basic ideas in the context of a simple example, closely related to the traditional Matching Pennies game. While not every two-person zero-sum finite game has an equilibrium in the set of pure strategies, von Neumann showed that there is always an equilibrium at which each player follows a mixed strategy. A mixed strategy deviating from the equilibrium strategy cannot increase a player's expected payoff. We show, however, that in our example a player who implements a quantum strategy can increase his expected payoff, and explain the relation to efficient quantum algorithms. We prove that in general a quantum strategy is always at least as good as a classical one, and furthermore that when both players use quantum strategies there need not be any equilibrium, but if both are allowed mixed quantum strategies there must be.Comment: 8 pages, plain TeX, 1 figur

Interobserver Agreement in the Clinical Assessment of Children With Blunt Abdominal Trauma

Objectives The objective was to determine the interobserver agreement of historical and physical examination findings assessed during the emergency department (ED) evaluation of children with blunt abdominal trauma. Methods This was a planned substudy of a multicenter, prospective cohort study of children younger than 18 years of age evaluated for blunt abdominal trauma. Patients were excluded if injury occurred more than 24 hours prior to evaluation or if computed tomography (CT) imaging was obtained at another hospital prior to transfer to a study site. Two clinicians independently recorded their clinical assessments of a convenience sample of patients onto data collection forms within 60 minutes of each other and prior to CT imaging (if obtained) or knowledge of laboratory results. The authors categorized variables as either subjective symptoms (i.e., patient history) or objective findings (i.e., physical examination). For each variable recorded by the two observers, the agreement beyond that expected by chance was estimated, using the kappa (κ) statistic for categorical variables and weighted κ for ordinal variables. Variables with 95% lower confidence limits (LCLs) κ ≥ 0.4 (moderate agreement or better) were considered to have acceptable agreement. Results A total of 632 pairs of physician observations were obtained on 23 candidate variables. Acceptable agreement was achieved in 16 (70%) of the 23 variables tested. For six subjective symptoms, κ ranged from 0.48 (complaint of shortness of breath) to 0.90 (mechanism of injury), and only the complaint of shortness of breath had a 95% LCL κ < 0.4. For the 17 objective findings, κ ranged from –0.01 (pelvis instability) to 0.82 (seat belt sign present). The 95% LCL for κ was <0.4 for flank tenderness, abnormal chest auscultation, suspicion of alcohol or drug intoxication, pelvis instability, absence of bowel sounds, and peritoneal irritation. Conclusions Observers can achieve at least acceptable agreement on the majority of historical and physical examination variables in children with blunt abdominal trauma evaluated in the ED. Those variables are candidates for consideration for development of a clinical prediction rule for intra‐abdominal injury in children with blunt trauma. Resumen Concordancia Interobservador en la Valoración Clínica de los Niños con Traumatismo Abdominal Cerrado Objetivos Determinar la concordancia interobservador de los hallazgos de la historia clínica y la exploración física obtenidos durante la valoración de los niños con traumatismo abdominal de alta energía en el servicio de urgencias (SU). Metodología Se diseñó un subestudio de un estudio de cohorte prospectivo y multicéntrico de niños de 18 años o menos evaluados por traumatismo abdominal cerrado. Se excluyeron los pacientes si el traumatismo había ocurrido más de 24 horas antes de la primera valoración, o si las imágenes de la tomografía computarizada (TC) se obtuvieron en otro hospital previamente a trasladarse al lugar del estudio. Dos clínicos recogieron de forma independiente su valoración clínica en un formulario de datos, de una muestra de conveniencia de pacientes, en los primeros 60 minutos, y previamente a las imágenes de la TC (si ésta se realizó) o al conocimiento de los resultados del laboratorio. Se clasificaron las variables como síntomas subjetivos (ej.: historia del paciente) o hallazgos objetivos (ej.: exploración física). Para cada variable recogida por los dos observadores, se estimó la concordancia más allá de la esperada por el azar usando el índice kappa (κ) para las variables categóricas y índice κ ponderado para las variables ordinales. Se consideró que existía una concordancia aceptable para las variables con una κ ≥ 0,4 (concordancia moderada o buena) en el límite inferior del intervalo de confianza del 95% (IC 95%). Resultados Se obtuvieron 632 pares de observaciones clínicas en 23 variables candidatas. Se alcanzó la concordancia aceptable en 16 (70%) de ellas. Para los seis síntomas subjetivos, el rango de κ fue de 0,48 (queja de dificultad respiratoria) a 0,90 (mecanismo de la lesión), y sólo la queja de dificultad respiratoria tuvo una κ < 0,4 en el límite inferior del IC 95%. Para los 17 hallazgos objetivos, el rango de κ fue desde ‐0,01 (inestabilidad pelvis) a 0,82 (presencia del signo del cinturón de seguridad). El dolor en el flanco, la auscultación torácica alterada, la sospecha de intoxicación por alcohol o tóxicos, la inestabilidad de pelvis, la ausencia de ruidos intestinales y la irritación peritoneal tuvieron una κ < 0,4 en el límite inferior del IC 95%. Conclusiones Los observadores pueden alcanzar al menos una concordancia aceptable en la mayoría de las variables de la historia clínica y la exploración física en los niños con traumatismo abdominal cerrado evaluado en el SU. Estas variables son candidatas para considerarse en el desarrollo de una regla de predicción clínica para la lesión intrabdominal en los niños con traumatismo de cerrado.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98339/1/acem12132.pd