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Geomorphic control on the δ15N of mountain forest
R. G. Hilton,A. Galy,A. J. West,N. Hovius
Biogeosciences Discussions , 2012, DOI: 10.5194/bgd-9-12593-2012
Abstract: Mountain forests are subject to high rates of physical erosion which can export particulate nitrogen from ecosystems. However, the impact of geomorphic processes on nitrogen budgets remains poorly constrained. We have used the elemental and isotopic composition of soil and plant organic matter to investigate nitrogen cycling in the mountain forest of Taiwan, from 24 sites with distinct geomorphic (topographic slope) and climatic (precipitation, temperature) characteristics. The organic carbon to nitrogen ratio of soil organic matter decreased with soil 14C age, providing constraint on average rates of nitrogen loss using a mass balance model. Model predictions suggest that present day estimates of nitrogen deposition exceed contemporary and historic nitrogen losses. We found ~6‰ variability in the stable isotopic composition (δ15N) of soil and plants which was not related to soil 14C age or climatic conditions. Instead, δ15N was significantly, negatively correlated with topographic slope. Using the mass balance model, we demonstrate that the correlation can be explained by an increase in nitrogen loss by non-fractioning pathways on steeper slopes, where physical erosion effectively removes particulate nitrogen. Published data from forest on steep slopes are consistent with the correlation, demonstrating that variable physical erosion rates can significantly influence soil δ15N, and that particulate nitrogen export is a major loss term in the nitrogen budget of mountain forest.
Geomorphic control on the δ15N of mountain forests
R. G. Hilton, A. Galy, A. J. West, N. Hovius,G. G. Roberts
Biogeosciences (BG) & Discussions (BGD) , 2013,
Abstract: Mountain forests are subject to high rates of physical erosion which can export particulate nitrogen from ecosystems. However, the impact of geomorphic processes on nitrogen budgets remains poorly constrained. We have used the elemental and isotopic composition of soil and plant organic matter to investigate nitrogen cycling in the mountain forest of Taiwan, from 24 sites with distinct geomorphic (topographic slope) and climatic (precipitation, temperature) characteristics. The organic carbon to nitrogen ratio of soil organic matter decreased with soil 14C age, providing constraint on average rates of nitrogen loss using a mass balance model. Model predictions suggest that present day estimates of nitrogen deposition exceed contemporary and historic nitrogen losses. We found ～6‰ variability in the stable isotopic composition (δ15N) of soil and plants which was not related to soil 14C age or climatic conditions. Instead, δ15N was significantly, negatively correlated with topographic slope. Using the mass balance model, we demonstrate that the correlation can be explained by an increase in nitrogen loss by non-fractioning pathways on steeper slopes, where physical erosion most effectively removes particulate nitrogen. Published data from forests on steep slopes are consistent with the correlation. Based on our dataset and these observations, we hypothesise that variable physical erosion rates can significantly influence soil δ15N, and suggest particulate nitrogen export is a major, yet underappreciated, loss term in the nitrogen budget of mountain forests.
Economical impact of orchiectomy for advanced prostate cancer
Paula Adriano A. P. de,Piccelli Hilton R. S.,Pinto Nilson P.,Teles Antonio G.
International braz j urol , 2003,
Abstract: PURPOSE: To demonstrate the economical impact of surgical castration in comparison to the medical castration for patients with advanced prostate cancer. MATERIAL AND METHODS: Between January 2001 and December 2001, 32 patients with advanced prostate cancer underwent bilateral sub-capsular orchiectomy at our Hospital. The costs of this procedure were compared to the costs of medical castration with LH-RH analogues. RESULTS: The costs of the surgical procedure were extremely reduced when compared to published data on the medical treatment. Surgical castration did not have any stronger negative impact on the evolution of these patients when compared to medical castration. CONCLUSION: Surgical castration is an efficient and low cost treatment for advanced prostate cancer.
Deterministic Multicultural Dynamic Networks: Seeking a Balance between Attractive and Repulsive Forces  [PDF]
Kristina B. Hilton, G. S. Ladde
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2016, DOI: 10.4236/ijcns.2016.912045
Abstract: An important issue in society is the attempt to balance communities working co-operatively and cohesively with one another while allowing members the ability to retain individuality and fostering an environment of cultural diversity. We seek to study the cohesive properties of a culturally diverse dynamic social network. By considering a multi-agent dynamic network, we seek to model a social structure and find conditions under which cohesion and coexistence are maintained. We present a specific illustration that serves to establish the framework in which explicit sufficient conditions in terms of system parameters are found for which the network is cohesive. By utilizing Lyapunov’s Second Method and comparison equations, we are able to find such conditions for the given illustration. Further, for the illustration, we decompose the cultural state domain into invariant sets and consider the behavior of members within each set. Moreover, we analyze the relative cultural affinity between individual members relative to the center of the social network. We also demonstrate how conservative the estimates are using Euler type numerical approximation schemes based on the given illustration. We are then able to consider how changes in the various parameters affect the dynamics of the illustrated network. By gaining such insight into the behavior of the illustrated network, we are able to better understand the impact of both attractive and repulsive influences on the network. This leads to establishing a schema for helping when creating policies and practices catered to promoting both diversity and cohesion within a cultural network.
Circulating anions usually associated with the Krebs cycle in patients with metabolic acidosis
Lui G Forni, William McKinnon, Gwyn A Lord, David F Treacher, Jean-Marie R Peron, Philip J Hilton
Critical Care , 2005, DOI: 10.1186/cc3806
Abstract: Plasma ultrafiltrate from patients with diabetic ketoacidosis, lactic acidosis, acidosis of unknown cause, normal anion gap metabolic acidosis, or acidosis as a result of base loss were examined enzymatically for the presence of low molecular weight anions including citrate, isocitrate, α-ketoglutarate, succinate, malate and d-lactate. The results obtained from the study groups were compared with those obtained from control plasma from normal volunteers.In five patients with lactic acidosis, a significant increase in isocitrate (0.71 ± 0.35 mEq l-1), α-ketoglutarate (0.55 ± 0.35 mEq l-1), malate (0.59 ± 0.27 mEq l-1), and d-lactate (0.40 ± 0.51 mEq l-1) was observed. In 13 patients with diabetic ketoacidosis, significant increases in isocitrate (0.42 ± 0.35 mEq l-1), α-ketoglutarate (0.41 ± 0.16 mEq l-1), malate (0.23 ± 0.18 mEq l-1) and d-lactate (0.16 ± 0.07 mEq l-1) were seen. Neither citrate nor succinate levels were increased. Similar findings were also observed in a further five patients with high anion gap acidosis of unknown origin with increases in isocitrate (0.95 ± 0.88 mEq l-1), α-ketoglutarate (0.65 ± 0.20 mEq l-1), succinate (0.34 ± 0.13 mEq l-1), malate (0.49 ± 0.19 mEq l-1) and d-lactate (0.18 ± 0.14 mEq l-1) being observed but not in citrate concentration. In five patients with a normal anion gap acidosis, no increases were observed except a modest rise in d-lactate (0.17 ± 0.14 mEq l-1).The levels of certain low molecular weight anions usually associated with intermediary metabolism were found to be significantly elevated in the plasma ultrafiltrate obtained from patients with metabolic acidosis. Our results suggest that these hitherto unmeasured anions may significantly contribute to the generation of the anion gap in patients with lactic acidosis and acidosis of unknown aetiology and may be underestimated in diabetic ketoacidosis. These anions are not significantly elevated in patients with normal anion gap acidosis.Metabolic acidosis is a common
Amplification and squeezing of quantum noise with a tunable Josephson metamaterial
M. A. Castellanos-Beltran,K. D. Irwin,G. C. Hilton,L. R. Vale,K. W. Lehnert
Physics , 2008, DOI: 10.1038/nphys1090
Abstract: It has recently become possible to encode the quantum state of superconducting qubits and the position of nanomechanical oscillators into the states of microwave fields. However, to make an ideal measurement of the state of a qubit, or to detect the position of a mechanical oscillator with quantum-limited sensitivity requires an amplifier that adds no noise. If an amplifier adds less than half a quantum of noise, it can also squeeze the quantum noise of the electromagnetic vacuum. Highly squeezed states of the vacuum serve as an important quantum information resource. They can be used to generate entanglement or to realize back-action-evading measurements of position. Here we introduce a general purpose parametric device, which operates in a frequency band between 4 and 8 GHz. It is a subquantum-limited microwave amplifier, it amplifies quantum noise above the added noise of commercial amplifiers, and it squeezes quantum fluctuations by 10 dB.
Bandwidth and dynamic range of a widely tunable Josephson parametric amplifier
M. A. Castellanos-Beltran,K. D. Irwin,L. R. Vale,G. C. Hilton,K. W. Lehnert
Physics , 2009, DOI: 10.1109/TASC.2009.2018119
Abstract: The ability to manipulate quantum information encoded in microwave fields has led to a renewed interest in Josephson parametric amplifiers (JPAs). For these applications the ability of JPAs to amplify signals with the least amount of added noise is critical. Unfortunately JPAs are typically narrow band amplifiers with small dynamic range. It is therefore important to understand the bandwidth and dynamic range of any particular JPA in order to determine if it is appropriate for these applications. We recently introduced a new kind of JPA. Although it is still narrow band, the amplified band can be tuned over a full octave. We have shown that it has good noise performance and can squeeze the vacuum noise by 10 dB. Here we characterize other important parameters of this amplifier, specifically the signal-bandwidth, dynamic range and saturation power.
Design and Testing of Superconducting Microwave Passive Components for Quantum Information Processing
H. S. Ku,F. Mallet,L. R. Vale,K. D. Irwin,S. E. Russek,G. C. Hilton,K. W. Lehnert
Physics , 2010, DOI: 10.1109/TASC.2010.2089403
Abstract: We report on the design, fabrication and testing of two superconducting passive microwave components, a quadrature hybrid and a 20 dB directional coupler. These components are designed to be integrated with superconducting qubits or Josephson parametric amplifiers and used in quantum information processing applications. For the coupler, we measure return loss and isolation > 20 dB, and insertion loss < 0.3 dB in a 2 GHz band around 6 GHz. For the hybrid performance, we measure isolation > 20 dB and insertion loss < 0.3 dB in a 10% band around 6.5 GHz. These values are within the design specifications of our application; however, we find a 7% difference between the designed and measured center frequency for the hybrid.
Economical impact of orchiectomy for advanced prostate cancer
Paula, Adriano A. P. de;Piccelli, Hilton R. S.;Pinto, Nilson P.;Teles, Antonio G.;Franqueiro, Antonio G.;Maltez, Adriano R. L.;Silva, Jose H.;
International braz j urol , 2003, DOI: 10.1590/S1677-55382003000200006
Abstract: purpose: to demonstrate the economical impact of surgical castration in comparison to the medical castration for patients with advanced prostate cancer. material and methods: between january 2001 and december 2001, 32 patients with advanced prostate cancer underwent bilateral sub-capsular orchiectomy at our hospital. the costs of this procedure were compared to the costs of medical castration with lh-rh analogues. results: the costs of the surgical procedure were extremely reduced when compared to published data on the medical treatment. surgical castration did not have any stronger negative impact on the evolution of these patients when compared to medical castration. conclusion: surgical castration is an efficient and low cost treatment for advanced prostate cancer.
Optimization and analysis of code-division multiplexed TES microcalorimeters
J. W. Fowler,W. B. Doriese,G. C. Hilton,K. D. Irwin,D. R. Schmidt,G. M. Stiehl,D. S. Swetz,J. N. Ullom,L. R. Vale.
Physics , 2011, DOI: 10.1007/s10909-012-0463-4
Abstract: We are developing code-division multiplexing (CDM) systems for transition-edge sensor arrays with the goal of reaching multiplexing factors in the hundreds. We report on x-ray measurements made with a four-channel prototype CDM system that employs a flux-summing architecture, emphasizing data-analysis issues. We describe an empirical method to determine the demodulation matrix that minimizes cross-talk. This CDM system achieves energy resolutions of between 2.3 eV and 3.0 eV FWHM at 5.9 keV.
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