bluuebunny/crossref_metadata_2025 huggingface dataset:
Caregiver Acceptability and Preferences for Early Childhood Caries Preventive Treatments for Hispanic Children
Authors: Adams Sally H. , Hyde Susan , Gansky Stuart A.
Published: March 2009

Objective: The objective of this study was to determine caregiver treatment acceptability and preferences for five preventive dental treatments for early childhood caries in young Hispanic children. Methods: We interviewed 211 parents/caregivers of Hispanic children attending Head Start programs regarding their acceptability of, and preferences for, five standard preventive dental treatments for young children. Treatments assessed were toothbrushing with fluoride toothpaste, fluoride varnish, and xylitol in food for children, and xylitol gum and chlorhexidine rinse for mothers. The interview assessment included presentation of illustrated cards with verbal description of treatment, photograph/video clip, and treatment samples. Parents rated the acceptability of each treatment (1‐5 scale) and treatment preferences within each of 10 possible pairs. Individual treatment preferences were summed to create overall preference scores (range 0‐4). Results: All treatments were rated as highly acceptable, however, there were differences (range 4.6‐4.9; Friedman chi‐square = 23.4, P < 0.001). Chlorhexidine, toothbrushing, and varnish were most acceptable, not different from each other, but more acceptable than xylitol in food (P < 0.05). Summed treatment preferences revealed greater variability (means ranged 1.4‐2.6; Friedman chi‐square = 128.2, P < 0.001). Fluoride varnish (2.6) and toothbrushing (2.5) were most highly preferred, and differences between preferences for xylitol in food (1.4), xylitol gum (1.5), and chlorhexidine (2.1) were all significant (P < 0.001). Preferences for chlorhexidine were also significantly greater than those for the xylitol products (P < 0.001). Conclusions: All five treatments were highly acceptable, however, when choosing among treatments overall, fluoride varnish and toothbrushing were favored over other treatments.
SYNCHRONISATION BETWEEN SOUTH AFRICA AND THE U.S.: A STRUCTURAL DYNAMIC FACTOR ANALYSIS
Authors: Kabundi Alain
Published: March 2009

This paper studies the synchronisation of the South African and the US cycles and transmission channels through which supply and demand shocks from the US affect economic activity in South Africa in a structural dynamic factor model framework. We find, using the full‐sample period, US supply shocks are transmitted to South Africa through business confidence and imports of goods and services; while US demand shocks are transmitted via interest rates, stock prices, exports of goods and services, and real effective exchange rates. Second, there is a decrease in integration over time translated by a drop in synchronisation of cycles. The impact of an increase in comovement of GDP is outweighed by the structural reforms initiated by the government after the end of apartheid. Finally, the idiosyncratic component still plays an important role in the South African economy.
TRPC channels function independently of STIM1 and Orai1
Authors: DeHaven Wayne I. , Jones Bertina F. , Petranka John G. , Smyth Jeremy T. , Tomita Takuro , Bird Gary S. , Putney James W.
Published: March 2009

Recent studies have defined roles for STIM1 and Orai1 as calcium sensor and calcium channel, respectively, for Ca2+‐release activated Ca2+ (CRAC) channels, channels underlying store‐operated Ca2+ entry (SOCE). In addition, these proteins have been suggested to function in signalling and constructing other channels with biophysical properties distinct from the CRAC channels. Using the human kidney cell line, HEK293, we examined the hypothesis that STIM1 can interact with and regulate members of a family of non‐selective cation channels (TRPC) which have been suggested to also function in SOCE pathways under certain conditions. Our data reveal no role for either STIM1 or Orai1 in signalling of TRPC channels. Specifically, Ca2+ entry seen after carbachol treatment in cells transiently expressing TRPC1, TRPC3, TRPC5 or TRPC6 was not enhanced by the co‐expression of STIM1. Further, knockdown of STIM1 in cells expressing TRPC5 did not reduce TRPC5 activity, in contrast to one published report. We previously reported in stable TRPC7 cells a Ca2+ entry which was dependent on TRPC7 and appeared store‐operated. However, we show here that this TRPC7‐mediated entry was also not dependent on either STIM1 or Orai1, as determined by RNA interference (RNAi) and expression of a constitutively active mutant of STIM1. Further, we determined that this entry was not actually store‐operated, but instead TRPC7 activity which appears to be regulated by SERCA. Importantly, endogenous TRPC activity was also not regulated by STIM1. In vascular smooth muscle cells, arginine‐vasopressin (AVP) activated non‐selective cation currents associated with TRPC6 activity were not affected by RNAi knockdown of STIM1, while SOCE was largely inhibited. Finally, disruption of lipid rafts significantly attenuated TRPC3 activity, while having no effect on STIM1 localization or the development of ICRAC. Also, STIM1 punctae were found to localize in regions distinct from lipid rafts. This suggests that TRPC signalling and STIM1/Orai1 signalling occur in distinct plasma membrane domains. Thus, TRPC channels appear to be activated by mechanisms dependent on phospholipase C which do not involve the Ca2+ sensor, STIM1.
CaMKII phosphorylation of the GABAA receptor: receptor subtype‐ and synapse‐specific modulation
Authors: Houston Catriona M. , He Qionger , Smart Trevor G.
Published: March 2009

As a major inhibitory neurotransmitter, GABA plays a vital role in the brain by controlling the extent of neuronal excitation. This widespread role is reflected by the ubiquitous distribution of GABAA receptors throughout the central nervous system. To regulate the level of neuronal inhibition requires some endogenous control over the release of GABA and/or its postsynaptic response. In this context, Ca2+ ions are often used as primary or secondary messengers frequently resulting in the activation of protein kinases and phosphatases. One such kinase, Ca2+/calmodulin‐dependent protein kinase II (CaMKII), can target the GABAA receptor to cause its phosphorylation. Evidence is now emerging, which is reviewed here, that GABAA receptors are indeed substrates for CaMKII and that this covalent modification alters the expression of cell surface receptors and their function. This type of regulation can also feature at inhibitory synapses leading to long‐term inhibitory synaptic plasticity. Most recently, CaMKII has now been proposed to differentially phosphorylate particular isoforms of GABAA receptors in a synapse‐specific context.
TRPC1 and STIM1 mediate capacitative Ca2+ entry in mouse pulmonary arterial smooth muscle cells
Authors: Ng Lih Chyuan , McCormack Mary D. , Airey Judith A. , Singer Cherie A. , Keller Phillip S. , Shen Xiao‐Ming , Hume Joseph R.
Published: March 2009

Previous studies in pulmonary arterial smooth muscle cells (PASMCs) showed that the TRPC1 channel mediates capacitative Ca2+ entry (CCE), but the molecular signal(s) that activate TRPC1 in PASMCs remains unknown. The aim of the present study was to determine if TRPC1 mediates CCE through activation of STIM1 protein in mouse PASMCs. In primary cultured mouse PASMCs loaded with fura‐2, cyclopiazonic acid (CPA) caused a transient followed by a sustained rise in intracellular Ca2+ concentration ([Ca2+]i). The transient but not the sustained rise in [Ca2+]i was partially inhibited by nifedipine. In addition, CPA increased the rate of Mn2+ quench of fura‐2 fluorescence that was inhibited by SKF 96365, Ni2+, La3+ and Gd3+, exhibiting pharmacological properties characteristic of CCE. The nifedipine‐insensitive sustained rise in [Ca2+]i and the increase in Mn2+ quench of fura‐2 fluorescence caused by CPA were both inhibited in cells pretreated with antibody raised against an extracellular epitope of TRPC1. Moreover, STIM1 siRNA reduced the rise in [Ca2+]i and Mn2+ quench of fura‐2 fluorescence caused by CPA, whereas overexpression of STIM1 resulted in a marked increase in these responses. RT‐PCR revealed TRPC1 and STIM1 mRNAs, and Western blot analysis identified TRPC1 and STIM1 proteins in mouse PASMCs. Furthermore, TRPC1 was found to co‐immunoprecipitate with STIM1, and the precipitation level of TRPC1 was increased in cells subjected to store depletion. Taken together, store depletion causes activation of voltage‐operated Ca2+ entry and CCE. These data provide direct evidence that CCE is mediated by TRPC1 channel through activation of STIM1 in mouse PASMCs.
Optimal Offloading Configuration of Spread-Moored FPSOs
Authors: Wilkerson Steven M. , Nagarajaiah Satish
Published: March 2009

As the oil offloading operations of floating production storage and offloading (FPSO) units become more routine, the desire grows to increase the availability for offloading and thus decrease production downtime. Experience with these operations is the main tool available to increase the efficiency of this aspect of deepwater production. However, it is clear that a formal optimization approach can help to fine tune design parameters so that not only is availability increased but the significance of each design parameter can be better understood. The key issue is to define the environmental conditions under which the vessels involved in offloading are able to maintain position. By this, we reduce the notion of availability to a set of operating criteria, which can or cannot be met for a particular set of environmental conditions. The actual operating criteria such as relative vessel heading depend on selection of design parameters, such as the direction and magnitude of external force applied by thrusters or tugs. In the earliest offloading operations, engineering judgment was used to determine the feasibility of offloading at a particular time. For example, if wind and current were not expected to exceed a 1year return period, offloading may be considered safe. This approach can be both conservative and unconservative, depending on the nuances of the particular environmental conditions. This study will propose a formal approach to choosing the design parameters that optimize the availability of a FPSO for offloading. A simple analysis model will be employed so that optimization can be performed quickly using a robust second order method. The proposed analysis model will be compared to model test data to demonstrate its agreement with the more complex system.
The Equivalent Depth of Wave-Induced Scour Around Offshore Pipelines
Authors: Mousavi Mir Emad , Bakhtiary Abbas Yeganeh , Enshaei Nastaran
Published: March 2009

Physical experiments have been conducted to study the scouring around a pipe over an erodible bed under wave motion. The results show that the depth of the wave-induced scour is reduced when the pipe is installed in a primary depth. It is also indicated that when the primary installation depth of the pipe, |e|, exceeds a specified depth, no scouring occurs underneath the pipe. This specific depth is called the equivalent depth of wave-induced scour, Se. The equivalent depth of wave-induced scour is estimated as a function of pipe diameter and the Keulegan–Carpenter number. With respect to the primary installation depth of the pipe, a new equation is suggested to predict the scour depth before installation of the pipe. And the scour width is predicted in two other new equations. The proposed equations are then simplified in the form of diagrams. The experiments cover small KC numbers (KC<6) that represent deep water conditions.
The use of a diode matrix in commissioning activities for electron energies : A feasibility study
Authors: Borca Valeria Casanova , Pasquino Massimo , Ozzello Franca , Tofani Santi
Published: March 2009

The contribution of a commercially available diode matrix (MapCHECK™, provided by Sun Nuclear, Melbourne, FL) for the commissioning procedures of the voxel based Monte Carlo algorithm for electron beams of MasterPlan treatment planning system was investigated. The attention is mainly focused on the calculation in homogeneous and heterogeneous phantoms. With this aim, following a data set similar to that proposed by Electron Collaborative Working Group (ECWG), the dose profiles and two‐dimensional (2D) dose distributions measured by the diode matrix were compared with the calculated ones using the gamma analysis method with acceptance criteria for the dose difference and the distance to agreement equal to 4% and 4 mm, respectively. The average and standard deviation of the percentage of points satisfying the constraint are and for the 9 and 12 MeV electron beam, respectively, showing that the accuracy of MasterPlan electron beam algorithm is good for simple two‐dimensional geometries as well as for more complicated three‐dimensional ones. The results are in agreement with those reported in literature by Cygler et al. [“Evaluation of the first commercial Monte Carlo dose calculation engine for electron beam treatment planning,” Med. Phys. 31, 142–153 (2004)]. In addition, the authors have also analyzed the response of the 2D array in terms of dose profiles at different depths, comparing the results with those obtained in water phantom using an electron diode. The results show that in the low gradient regions there were no deviations larger than the criteria of acceptability set by Van Dyk et al. [“Commissioning and quality assurance of treatment planning computers,” Int. J. Radiat. Oncol. Biol. Phys. 26, 261–273 (1993)]; in the high gradient region, the maximum deviations are less than 2 mm with most of the values less than 1 mm. The present article shows that MapCHECK™ can play a useful role in the commissioning of electron algorithms of treatment planning systems in the evaluation of the 2D dose distributions in homogeneous and heterogeneous phantoms. In fact, it provides accurate results with the merit of expediting the commissioning process by using measuring device that requires minimal setup time and data processing time.
3D reconstruction of a patient‐specific surface model of the proximal femur from calibrated x‐ray radiographs: A validation studya)
Authors: Zheng Guoyan , Schumann Steffen
Published: March 2009

Twenty‐three femurs (one plastic bone and twenty‐two cadaver bones) with both nonpathologic and pathologic cases were considered to validate a statistical shape model based technique for three‐dimensional (3D) reconstruction of a patient‐specific surface model from calibrated x‐ray radiographs. The 3D reconstruction technique is based on an iterative nonrigid registration of the features extracted from a statistically instantiated 3D surface model to those interactively identified from the radiographs. The surface models reconstructed from the radiographs were compared to the associated ground truths derived either from a 3D CT‐scan reconstruction method or from a 3D laser‐scan reconstruction method and an average error distance of 0.95 mm were found. Compared to the existing works, our approach has the advantage of seamlessly handling both nonpathologic and pathologic cases even when the statistical shape model that we used was constructed from surface models of nonpathologic bones.
Unintended attenuation in the Leksell Gamma Knife® Perfexion™ calibration‐phantom adaptor and its effect on dose calibration
Authors: Bhatnagar Jagdish P. , Novotny Josef , Quader Mubina A. , Bednarz Greg , Huq M. Saiful
Published: March 2009

The calibration of Leksell Gamma Knife Perfexion (LGK PFX) is performed using a spherical polystyrene phantom 160 mm in diameter, which is provided by the manufacturer. This is the same phantom that has been used with LGK models U, B, C, and 4C. The polystyrene phantom is held in irradiation position by an aluminum adaptor, which has stainless steel side‐fixation screws. The phantom adaptor partially attenuates the beams from sectors 3 and 7 by 3.2% and 4.6%, respectively. This unintended attenuation introduces a systematic error in dose calibration. The overall effect of phantom‐adaptor attenuation on output calibration of the LGK PFX unit is to underestimate output by about 1.0%.
Physical performance and image optimization of megavoltage cone‐beam CT
Authors: Morin Olivier , Aubry Jean‐François , Aubin Michèle , Chen Josephine , Descovich Martina , Hashemi Ali‐Bani , Pouliot Jean
Published: March 2009

Megavoltage cone‐beam CT (MVCBCT) is the most recent addition to the in‐room CT systems developed for image‐guided radiation therapy. The first generation MVCBCT system consists of a treatment x‐ray beam produced by a conventional linear accelerator equipped with a flat panel amorphous silicon detector. The objective of this study was to evaluate the physical performance of MVCBCT in order to optimize the system acquisition and reconstruction parameters for image quality. MVCBCT acquisitions were performed with the clinical system but images were reconstructed and analyzed with a separate research workstation. The geometrical stability and the positioning accuracy of the system were evaluated by comparing geometrical calibrations routinely performed over a period of . The beam output and detector intensity stability during MVCBCT acquisition were also evaluated by analyzing in‐air acquisitions acquired at different exposure levels. Several system parameters were varied to quantify their impact on image quality including the exposure (2.7, 4.5, 9.0, 18.0, and ), the craniocaudal imaging length (2, 5, 15, and ), the voxel size (0.5, 1, and ), the slice thickness (1, 3, and ), and the phantom size. For the reconstruction algorithm, the study investigated the effect of binning, averaging and diffusion filtering of raw projections as well as three different projection filters. A head‐sized water cylinder was used to measure and improve the uniformity of MVCBCT images. Inserts of different electron densities were placed in a water cylinder to measure the contrast‐to‐noise ratio (CNR). The spatial resolution was obtained by measuring the point‐spread function of the system using an iterative edge blurring technique. Our results showed that the geometric stability and accuracy of MVCBCT were better than over a period of . Beam intensity variations per projection of up to 35.4% were observed for a MVCBCT acquisition. These variations did not cause noticeable reduction in the image quality. The results on uniformity suggest that the cupping artifact occurring with MVCBCT is mostly due to off‐axis response of the detector and not scattered radiation. Simple uniformity correction methods were developed to nearly eliminate this cupping artifact. The spatial resolution of the baseline MVCBCT reconstruction protocol was approximately . An optimized reconstruction protocol was developed and showed an improvement of 75% in CNR with a penalty of only 8% in spatial resolution. Using this new reconstruction protocol, large adipose and muscular structures were differentiated at an exposure of . A reduction of 36% in CNR was observed on a larger (pelvic‐sized) phantom. This study demonstrates that soft‐tissue visualization with MVCBCT can be substantially improved with proper system settings. Further improvement is expected from the next generation MVCBCT system with an optimized megavoltage imaging beamline.
A method to improve accuracy and precision of water surface identification for photon depth dose measurementsa)
Authors: Ververs J. D. , Schaefer M. J. , Kawrakow I. , Siebers J. V.
Published: March 2009

The objective of this study is to present a method to reduce the setup error inherent in clinical depth dose measurements and, in doing so, to improve entrance dosimetry measurement reliability. Ionization chamber (IC) depth dose measurements are acquired with the depth scan extended into the air above the water surface. An inflection region is obtained in each resulting percent depth ionization (PDI) curve that can be matched against other measurements or to an inflection region obtained from an analogous Monte Carlo (MC) simulation. Measurements are made with various field sizes for the 6 and photon beams, with and without a Pb foil in the beam, to determine the sensitivity of the dose inflection region to the beam conditions. The offset between reference and test data set inflection regions is quantified using two separate methods. When comparing sets of measured data, maxima in the second derivative of ionization are compared. When comparing measured data to MC simulation, the offset that minimizes the sum of squared differences between the reference and test curves in the ionization inflection region is found. These methods can be used to quantify the offset between an initial setup (test) position and the true surface (reference) position. The ionization inflection location is found to be insensitive to changes in field size, electron contamination, and beam energy. Data from a single reference condition should be sufficient to identify the surface location. The method of determining IC offsets is general and should be applicable to any IC and other radiation sources. The measurement method could reduce the time and effort required in the initial IC setup at a water surface as setup errors can be corrected offline. Given a reliable set of reference data to compare with, this method could increase the ability of quality assurance (QA) measurements to detect discrepancies in beam output as opposed to discrepancies in IC localization. Application of the measurement method standardizes the procedure for localizing cylindrical ICs at a water surface and thereby improves the reliability of measurements taken with these devices at all depths.
Bacteriostatic and Bactericidal Activities of Tigecycline against
Coxiella burnetii
and Comparison with Those of Six Other Antibiotics
Authors: Spyridaki Ioanna , Psaroulaki Anna , Vranakis Iosif , Tselentis Yannis , Gikas Achilleas
Published: March 2009

The present article is a study of the in vitro susceptibility of eight Greek
Coxiella burnetii
isolates, derived from patients with acute Q fever, and two reference strains of
Coxiella burnetii
to tigecycline. The bacteriostatic activity of tigecycline was compared with those of six other antibiotics using a shell vial assay. The MICs of the examined antibiotics were as follows: tigecycline ranged from 0.25 to 0.5 μg/ml; doxycycline, trovafloxacin, and ofloxacin ranged from 1 to 2 μg/ml; linezolid and clarithromycin ranged from 2 to 4 μg/ml; and ciprofloxacin ranged from 4 to 8 μg/ml. Tigecycline was effective in inhibiting the infection of Vero cells by
C. burnetii
. No bactericidal activity was observed against
C. burnetii
at 4 μg/ml.
TheFasciola hepaticaTegumental Antigen Suppresses Dendritic Cell Maturation and Function
Authors: Hamilton Clare M. , Dowling David J. , Loscher Christine E. , Morphew Russell M. , Brophy Peter M. , O'Neill Sandra M.
Published: March 2009

Parasitic worms and molecules derived from them have powerful anti-inflammatory properties and are shown to have therapeutic effects on inflammatory diseases. The helminthFasciola hepaticahas been reported to suppress antigen-specific Th1 responses in concurrent bacterial infections, thus demonstrating its anti-inflammatory ability in vivo. Here,F. hepaticategumental antigen (Teg) was shown to significantly suppress serum levels of gamma interferon (IFN-γ) and interleukin-12p70 (IL-12p70) in a model of septic shock. Since dendritic cells (DCs) are a good source of IL-12p70 and critical in driving adaptive immunity, we investigated the effects ofF. hepaticaTeg on the activation and function of murine DCs. While Teg alone did not induce cytokine production or cell surface marker expression on DCs, it significantly suppressed cytokine production (IL-12p70, IL-6, IL-10, tumor necrosis factor alpha, and nitrite) and cell surface marker expression (CD80, CD86, and CD40) in DCs matured with a range of Toll-like receptor (TLR) and non-TLR ligands. Teg works independently of the TLR4 pathway, since it still functioned in DCs generated from TLR4 mutant and knockout mice. It impaired DC function by inhibiting their phagocytic capacity and their ability to prime T cells. It does not appear to target the common components (extracellular signal-regulated kinase, Jun N-terminal protein kinase, or p38) of the TLR pathways; however, it suppressed the active p65 subunit of the transcription factor NF-κB in mature DCs, which could explain the impairment of proinflammatory cytokine production. Overall, our results demonstrate the potent anti-inflammatory properties ofF. hepaticaTeg and its therapeutic potential as an anti-inflammatory agent.
Overcoming paralogy and incomplete lineage sorting to detect a phylogeographic signal: a GapC study of Armeria pungens
Authors: Piñeiro Rosalía , Costa Andrea , Aguilar Javier Fuertes , Feliner Gonzalo Nieto
Published: March 2009

Low-copy nuclear genes have been suggested as a promising source of independent phylogeographic markers in plants. However, the available studies at the intraspecific level have revealed that extracting information from them is frequently hampered by paralogy and lack of coalescence of alleles. It is thus relevant to test their utility with plants for which solid data from other markers are available. The aims of this study are to retrieve phylogeographic useful information in a low-copy nuclear gene by examining the congruence of the genetic variation with the geography, as well as with previous nuclear ribosomal, plastid, and amplified fragment length polymorphism (AFLP) markers. Seven combinations of primers have been assayed to characterize the structure of GapC (cytosolic glyceraldehyde 3-phosphate dehydrogenase) in Armeria pungens (Link) Hoffmanns. & Link, a linearly distributed Atlantic–Mediterranean disjunct sand-dune species. A matrix of 101 direct sequences from 71 individuals was analysed with statistical parsimony. To check the reliability of direct sequencing, 216 cloned sequences were also generated. Tests of recombination have also been attempted. By comparing nucleotide and amino acid sequences, three different paralogs (1, 2, 3) were identified of which paralog 2 was sampled for phylogeographic inference. Within this paralog, 13 alleles belonging in three different sequence types (I, II, III) were detected. These types are shown to correspond with lineages from the same locus whose splitting predates the origin of A. pungens, although type III could be a recent paralog. Allelic variation within types I and II followed a clear geographic trend supporting the two main genetic lineages detected in A. pungens with previous markers. This study suggests that information on the population history of a species can be retrieved, even if some uncertainty remains on the source of variation of low-copy nuclear gene sequences, either alleles from the same locus or paralogs.
An empirical study of enrollment in Vermont's Use Value Appraisal property tax program
Authors: Dennis Donald F. , Sendak Paul E.
Published: March 2009

A probit model was used to analyze the relationship between the probability of enrollment in Vermont's Use Value Appraisal property tax program for forest land and characteristics of the parcel, owner, and surrounding community. The results suggest that continued fragmentation of the forest and population growth will have a negative effect on enrollment, but these effects may be mitigated by increases in the education level of landowners and by increases in assessed values and property tax rates.
Production efficiency of Abieslasiocarpa: influence of vertical distribution of leaf area
Authors: Roberts Scott D. , Long James N.
Published: March 2009

A simple conceptual model is proposed concerning how leaf area efficiency (stemwood growth per unit leaf area) changes with leaf area for trees within a stand. Greater leaf area is generally associated with (i) improved light environment due to greater height and (ii) a lower ratio of photosynthetic to nonphotosynthetic tissue. Greater height and improved light environment result in higher photosynthetic production, which should increase leaf area efficiency. A lower ratio of photosynthetic to nonphotosynthetic tissue suggests that the ratio of respiration to photosynthesis increases, which should decrease leaf area efficiency. In relatively small trees, the influence of increased height (associated with greater leaf area) should more than offset the influence of the increased respiration:photosynthesis ratio; as a result, leaf area efficiency should increase with leaf area. In large trees, further increases in leaf area are associated with minimal increases in height, and leaf area efficiency should decline as the respiration:photosynthesis ratio increases. Predictions from this conceptual model were examined with data from stands of subalpine fir (Abieslasiocarpa (Hook.) Nutt.).
Comparison of nonlinear height–diameter functions for major Alberta tree species
Authors: Huang Shongming , Titus Stephen J. , Wiens Douglas P.
Published: March 2009

Twenty nonlinear height–diameter functions were fitted and evaluated for major Alberta species based on a data set consisting of 13 489 felled trees for 16 different species. All functions were fitted using weighted nonlinear least squares regression (wi = 1/DBHi) because of the problem of unequal error variance. The examination and comparison of the weighted mean squared errors, the asymptotic t-statistics for the parameters, and the plots of studentized residuals against the predicted height show that many concave and sigmoidal functions can be used to describe the height–diameter relationships. The sigmoidal functions such as the Weibull-type function, the modified logistic function, the Chapman–Richards function, and the Schnute function generally gave the most satisfactory results.
Mortality and height growth losses of coniferous seedlings damaged by the black army cutworm
Authors: Maher T.F. , Shepherd R.F.
Published: March 2009

Growth and survival of seedlings were determined for 1 to 3 years following defoliation by black army cutworm, Actebiafennica (Tausch.). Ten data sets were collected on three sites and included four species of seedlings: interior Douglas-fir, Pseudotsugamenziesii var. glauca (Beissn.) Franco; lodgepole pine, Pinuscontorta Dougl.; western larch, Larixoccidentalis Nutt.; and Engelmann spruce, Piceaengelmannii Parry. Mortality following defoliation cannot be assessed until after the flush in the next growing season because completely defoliated seedlings often regenerate new foliage and survive. More than 90% of the total mortality that did occur was detected at that time. Mortality of up to 39% occurred when seedlings were defoliated more than 60%; most of this occurred when planting was carried out concurrent with defoliation. Synergistic root stress effects caused by poor planting, dry sites, or drought significantly increased mortality. Height growth was significantly reduced when defoliation was greater than 60%; the greatest effects occurred when terminal bud destruction accompanied needle loss. Growth losses were greatest the year of defoliation; recovery of height growth of lodgepole pine was complete by the 2nd year on good growing sites. On poor sites, retardation of lodgepole pine height growth was still evident after 3 years.
Internal and external control of net photosynthesis and stomatal conductance of mature eastern white pine (Pinusstrobus)
Authors: Maier C.A. , Teskey R.O.
Published: March 2009

Leaf gas exchange and water relations were monitored in the upper canopy of two 25 m tall eastern white pine (Pinusstrobus L.) trees over two consecutive growing seasons (1986 and 1987). Examination of the seasonal and diurnal patterns of net photosynthesis and leaf conductance showed that both internal and external (environmental) factors were controlling net photosynthesis and leaf conductance. Internal control was indicated by a rapid increase and then decrease in the photosynthetic capacity of 1-year-old foliage during the development and maturation of current-year foliage, which was independent of environmental conditions. Large differences in net photosynthesis were observed between growing seasons due to seasonal differences in soil water availability, as indexed by predawn xylem pressure potential. Water stress reduced the maximum rate of net photosynthesis and altered the response of net photosynthesis and leaf conductance to absolute humidity deficit.
Germination of two warm-temperate oaks, Quercusemoryi and Quercusarizonica
Authors: Nyandiga Charles O. , McPherson Guy R.
Published: March 2009

Quercusemoryi Torr. (emory oak) and Quercusarizonica Sarg. (Arizona white oak) are the dominant trees in many of the oak savannas and woodlands of Arizona and northern Mexico. The objectives of this study were (i) to evaluate germination on two media as influenced by storage and stratification and (ii) to determine the effects of oak canopy and depth of burial on acorn viability and germination. Germination was higher (P < 0.05) on filter paper than in mineral soil in laboratory trials. Maximum germination of Q. emoryi in the field was observed at a depth of 7.5 cm (29%), with only 5% germination at the soil surface. Germination of Q. arizonica at 7.5 and 15 cm (73%) was not different (P > 0.10) but exceeded germination at the surface (17%). These results represent the first reported germination of either species and indicate that recruitment into mature oak woodlands is not limited by germination.
Stand development in aspen clones
Authors: Krasny Marianne E. , Johnson Elizabeth A.
Published: March 2009

The growth of trembling aspen (Populustremuloides Michx.) sprouts in two separate clones was measured annually for 6 years and at year 12 (site 1) and for 5 years and at year 11 (site 2) following sprout initiation. Over 98% of the stems were established within the first growing season after cutting. By the end of the first growing season, height-frequency histograms were positively skewed and coefficients of variation of height were 56 and 60% for sites 1 and 2, respectively, reflecting the presence of many small and few large stems. By the 3rd year after establishment, over 50% mortality of stems occurred and the coefficients of variation of height had declined to approximately 47% for both sites. Although the results of this study may not have widespread implications because of the limited number of clones, the pattern of stand development observed in aspen was similar to that documented for even-aged monospecific stands of nonclonal woody species, with the possible exception that self-thinning occurred at a more rapid rate in aspen.
NEW n-MODE BOSE OPERATOR REALIZATION OF SU(2) LIE ALGEBRA AND ITS APPLICATION IN ENTANGLED FRACTIONAL FOURIER TRANSFORM
Authors: FAN HONG-YI , LIU SHU-GUANG
Published: March 2009

We introduce a new n-mode Bose operator realization of SU(2) Lie algebra and link it to the two mutually conjugate multipartite entangled state representations. In so doing we are naturally lead to the n-mode entangle fractional Fourier transform (EFFT), which provides us with a convenient way to deriving the EFFT of quantum-mechanical wave functions.
MULTI-MODE LINEAR COMPOSITE MOMENTUM REPRESENTATION AND ITS APPLICATION
Authors: XU SHI-MIN , XU XING-LEI , JIANG JI-JIAN , LI HONG-QI , WANG JI-SUO
Published: March 2009

A unitary transformation matrix, n linear-composite coordinate operators and n linear-composite momentum operators are constructed for an n-particle system, and the complete and orthonormal common eigenvectors of the multi-mode linear composite momentum operators are examined by virtue of the technique of integration within an ordered product of operators. The multi-mode linear composite momentum representation is proposed, and its application to a general two-mode forced quantum harmonic oscillator system with kinetic coupling is presented for solving some dynamic problems.
ALIGNMENT OF MINISATELLITE MAPS BASED ON RUN-LENGTH ENCODING SCHEME
Authors: ABOUELHODA MOHAMED I. , GIEGERICH ROBERT , BEHZADI BEHSHAD , STEYAERT JEAN-MARC
Published: March 2009

Subsequent duplication events are responsible for the evolution of the minisatellite maps. Alignment of two minisatellite maps should therefore take these duplication events into account, in addition to the well-known edit operations. All algorithms for computing an optimal alignment of two maps, including the one presented here, first deduce the costs of optimal duplication scenarios for all substrings of the given maps. Then, they incorporate the pre-computed costs in the alignment recurrence. However, all previous algorithms addressing this problem are dependent on the number of distinct map units (map alphabet) and do not fully make use of the repetitiveness of the map units. In this paper, we present an algorithm that remedies these shortcomings: our algorithm is alphabet-independent and is based on the run-length encoding scheme. It is the fastest in theory, and in practice as well, as shown by experimental results. Furthermore, our alignment model is more general than that of the previous algorithms, and captures better the duplication mechanism. Using our algorithm, we derive a quantitative evidence that there is a directional bias in the growth of minisatellites of the MSY1 dataset.
A Unified Scheme of Measurement and Amplification Processes Based on Micro-Macro Duality — Stern-Gerlach Experiment as a Typical Example
Authors: Harada Ryo , Ojima Izumi
Published: March 2009

A unified scheme for quantum measurement processes is formulated on the basis of micro-macro duality as a mathematical expression of the general idea of quantum-classical correspondence. In this formulation, we can naturally accommodate the amplification processes necessary for magnifying quantum state changes at the microscopic end of the probe system into the macroscopically visible motion of the measuring pointer. Its essence is exemplified and examined in the concrete model of the Stern-Gerlach experiment for spin measurement, where the Helgason duality controlling the Radon transform is seen to play essential roles.
Mental States Follow Quantum Mechanics During Perception and Cognition of Ambiguous Figures
Authors: Conte Elio , Khrennikov Andrei Yuri , Todarello Orlando , Federici Antonio , Mendolicchio Leonardo , Zbilut Joseph P.
Published: March 2009

Processes undergoing quantum mechanics exhibit quantum interference effects. In this case, quantum probabilities result to be different from classical ones because they contain an additional so-called quantum interference term. We use ambiguous figures to analyse if during perception-cognition by human subjects we can observe violation of the classical probability field and the presence of quantum interference. The experiments, conducted on a group of 256 subjects, evidence that we indeed have such a quantum effect. Therefore, mental states, during perception and cognition of ambiguous figures, appear to follow quantum mechanics.
LAPLACIAN EIGENVALUES OF GRAPHS WITH GIVEN DOMINATION NUMBER
Authors: Feng Lihua , Yu Guihai , Lin Xiqin
Published: March 2009

In this paper, we study the Laplacian eigenvalues of graphs on n vertices with domination number γ and present upper bounds for the Laplacian spectral radius and algebraic connectivity as well, which improve old results apparently.
3G Long Term Evolution Baseband Processing with Application-Specific Processors
Authors: Salmela Perttu , Antikainen Juho , Pitkänen Teemu , Silvén Olli , Takala Jarmo
Published: March 2009

Data rates in the upcoming 3G long term evolution (LTE) standard will be manifold when compared to the current universal mobile telecommunications system. Implementing receivers conforming with the high-capacity transmission techniques is challenging due to the complexity and computational requirements of algorithms. In this study, the software defined radio (SDR) is targeted and the four essential baseband functions of the 3G LTE receiver, namely, list sphere decoding, fast Fourier transform, QR decomposition, and turbo decoding, are addressed and the functions are implemented as application specific processors (ASPs). As a result, the design space that describes the essential computational challenges of 3G LTE receivers is clarified and estimates of area, power, and interprocessor communication buffer requirements are presented.
Müllerian Serous Cystadenoma of the Scrotum Following Orchiopexy
Authors: van der Putte Sebastian C. J. , Toonstra Johan , Sie-Go Daisy M. D. S.
Published: March 2009

A 24-year-old man presented himself with a nodular lesion of about 1 cm diameter at the site of a previous orchiopexy associated with surgery for cryptorchism. Histopathology revealed the lesion to be adenomatous and confined to the scrotum. Histological and immunohistological features were not consistent neither with median raphe cysts or cutaneous adenomas nor with the intrascrotal adenomas of the rete testis, epididymis, nor with (malignant) mesotheliomas. However, the lesion did compare well with serous (papillary) cystadenomas of the testis or paratestis. These adenomas are thought to originate in remnants of the Müllerian system or of peritoneal lining altered by Müllerian metaplasia. This implies that the scrotal adenoma may have developed from an implant of such elements during orchiopexy 14 years ago. Complete excision of the lesion appears to be an adequate therapy.
Boundedness, Attractivity, and Stability of a Rational Difference Equation with Two Periodic Coefficients
Authors: Papaschinopoulos G. , Stefanidou G. , Schinas C. J.
Published: March 2009

We study the boundedness, the attractivity, and the stability of the
positive solutions of the rational difference equation
xn+1 = (pnxn−2 + xn−3)/(qn + xn−3), n = 0, 1, …,
where pn, qn,
n = 0, 1, … are positive sequences of period 2.
Long-Term Outcome of Therapeutic Neovascularization Using Peripheral Blood Mononuclear Cells for Limb Ischemia
Authors: Moriya Junji , Minamino Tohru , Tateno Kaoru , Shimizu Naomi , Kuwabara Yoichi , Sato Yasunori , Saito Yasushi , Komuro Issei
Published: March 2009

Background—

Injection of bone marrow mononuclear cells has been reported to promote neovascularization of ischemic tissues effectively. We found that peripheral blood mononuclear cells were as efficient as bone marrow mononuclear cells for the treatment of limb ischemia in animals and showed that this treatment was feasible and safe in no-option patients with limb ischemia. However, the long-term outcome of such therapy has not been investigated.

Methods and Results—

We retrospectively analyzed the data for 42 patients who were treated between July 2002 and December 2005 by using the log-rank test, the Kaplan-Meier method, and the Cox proportional hazard model. Improvement of ischemic symptoms was observed in 60% to 70% of the patients. The annual rate of major amputation was decreased markedly by treatment. Improvement of ischemic symptoms was less marked in arteriosclerosis obliterans (ASO) patients on dialysis compared with nonhemodialysis ASO or thromboangiitis obliterans patients. Indeed, the survival rate of these patients was lower than that of nonhemodialysis ASO or thromboangiitis obliterans patients. Major adverse events such as death, major amputation, and cardiovascular events occurred mostly in ASO patients, and most of them were on dialysis. There was no significant difference in the cardiovascular event-free rate between responders and nonresponders. The survival rate of younger responders was better than that of nonresponders.

Conclusions—

Although this study was not placebo-controlled and these initial results were from a retrospective analysis, injection of peripheral blood mononuclear cells might be safe and potentially effective for the treatment of limb ischemia, but caution is needed when managing ASO patients on dialysis.
Prognostic Value of Changes in the Electrocardiographic Strain Pattern During Antihypertensive Treatment
Authors: Okin Peter M. , Oikarinen Lasse , Viitasalo Matti , Toivonen Lauri , Kjeldsen Sverre E. , Nieminen Markku S. , Edelman Jonathan M. , Dahlöf Björn , Devereux Richard B.
Published: March 2009

Background—

The presence of the ECG strain pattern of lateral ST depression and T-wave inversion at baseline has been associated with an increased risk of cardiovascular morbidity and mortality; however, the independent predictive value for cardiovascular outcomes of regression versus persistence versus development of new ECG strain during antihypertensive therapy is unclear.

Methods and Results—

ECG strain was evaluated at baseline and after 1 year of therapy in 7409 hypertensive patients in the LIFE study (Losartan Intervention For End-point reduction in hypertension) treated in a blinded manner with atenolol- or losartan-based regimens. During 3.8±0.8 years of follow-up after the year 1 ECG, cardiovascular death occurred in 236 patients (3.2%), myocardial infarction in 198 (2.7%), stroke in 313 (4.2%), the LIFE composite end point of these 3 events in 600 (8.1%), sudden death in 92 (1.2%), and death due to any cause in 486 (6.6%). Strain was absent on both baseline and year 1 ECGs in 6323 patients (85.3%), regressed from baseline to year 1 in 245 (3.3%), persisted on both ECGs in 549 (7.4%), and was absent at baseline but developed by year 1 in 292 patients (3.9%). Compared with absence of strain on both ECGs, development of new ECG strain was associated with 2.8- to 4.7-fold higher event rates; patients with regression or persistence of strain had intermediate event rates. In Cox multivariable analyses with adjustment for the known predictive value of in-treatment ECG left ventricular hypertrophy by Cornell product and Sokolow-Lyon voltage, in-treatment systolic and diastolic pressure, randomized treatment, and standard cardiovascular risk factors, development of new ECG strain was independently associated with increased risks of cardiovascular death (hazard ratio [HR] 2.42, 95% confidence interval [CI] 1.56 to 3.76), myocardial infarction (HR 1.95, 95% CI 1.11 to 3.44), stroke (HR 1.98, 95% CI 1.30 to 3.01), the LIFE composite end point (HR 2.05, 95% CI 1.51 to 2.78), sudden cardiac death (HR 2.19, 95% CI 1.06 to 4.53), and all-cause mortality (HR 1.92, 95% CI 1.37 to 2.69), whereas the risk associated with regression or persistence of strain was attenuated.

Conclusions—

Development of new ECG strain is associated with an increased risk of cardiovascular morbidity and mortality and of all-cause mortality in the setting of antihypertensive therapy and regression of ECG left ventricular hypertrophy.
Sea Level Variations in the Tropical Pacific Ocean and the Madden–Julian Oscillation
Authors: Zhang Xu , Lu Youyu , Thompson Keith R.
Published: March 2009

Satellite observations of sea level and surface wind from the tropical Pacific Ocean, and their relationship to the Madden–Julian oscillation (MJO), are analyzed using a combination of statistical techniques and a simple, physically based model. Wavenumber–frequency analysis reveals that sea level variations at the equator contain prominent eastward-propagating signals as the intraseasonal Kelvin waves. The component of sea level variation that is coherent with the MJO (ηMJO) is concentrated in a narrow strip along the equator between 150°E and 110°W. To explain the physical forcing of ηMJO, the component of zonal wind stress that is coherent with the MJO is also calculated. It is shown that is strongest in the western Pacific, but the MJO accounts for a higher percentage of the wind variance in the central equatorial Pacific. A simple linear model of the Kelvin waves, based on a first-order wave equation forced by and with a linear damping term included, successfully reproduces ηMJO. It is also shown that zonal wind variations to the east of the date line act to increase the apparent propagation speeds of the Kelvin waves.