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11.
Normal Standardbred horses were given an incremental exercise test on a horizontal treadmill to evaluate the influence of exercise on gas exchange, resistance, dynamic compliance and inertance of the respiratory system. The exercise test consisted of 2 min exercise steps at each of the following speeds: 2.4 m/sec (walk), 4.5 m/sec (slow trot), 7.0 m/sec (fast trot) and 10 m/sec (gallop). At rest and after 1 min of exercise at each step, airflow, tidal volume, respiratory frequency, pharyngeal, mid-oesophageal and transdiaphragmatic pressures and arterial blood gas tensions were measured. The same horses were subsequently treated intravenously with clenbuterol (0.8 microgram/kg) and an identical exercise test and measurement performed 10 min after clenbuterol injection. In response to exercise, there were large increases in tidal volume, respiratory frequency, airflow and pressures. Exercise was associated with a decrease in upper airway resistance but total pulmonary resistance was unchanged. Exercise did not alter inertance or dynamic compliance, horses became hypoxaemic, and at 10 m/sec (galloping) also developed hypercarbia. Treatment with clenbuterol did not alter any of these measurements in response to exercise. These data suggest that dilation of upper airways occurs during exercise, and that inertial forces are important in strenuously exercising horses and may influence the accuracy of dynamic compliance determinations at high exercise intensities. 相似文献
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Tomokazu Itano Hidemasa Kawakami Masahiro Sakai 《Aquaculture (Amsterdam, Netherlands)》2006,261(4):1175-1180
In an attempt to develop a vaccine against Nocardia seriolae, related species of live bacteria N. soli, N. fluminea, and N. uniformis were injected into yellowtail Seriola quinqueradiata. In addition, fish were challenged with a low virulence strain of N. seriolae to model the concept of use of a live vaccine. The fish injected with live N. soli and N. fluminea cells showed slight resistance against an artificial challenge with N. seriolae. On the other hand, the fish that survived the N. seriolae infection showed complete resistance to the N. seriolae challenge. These results suggest that protective immune responses against N. seriolae are induced in yellowtails. 相似文献
14.
To construct a new calibration method that combines usability and accuracy for estimating herbage mass from rising‐plate meter readings, we derived four models differing in the way their parameters are related to sampling date and compared their estimation accuracies using cross‐validation. The parameters of the linear regression for each sampling date showed seasonal variations, which had a steep decrease from early April to early June and a gradual increase thereafter. The pooled models were less accurate for estimating herbage mass than a separate model, which had specific parameters for each sampling date (S model). Among the pooled models, however, those in which the parameters were assumed to be linear functions (PL model) or combined functions (PC model) of the sampling date showed substantively improved estimation accuracy compared with the traditional pooled model, in which the parameters were assumed to be fixed throughout the year (PF model). Moreover, at the beginning of the season, the models derived from previous years' data were suggested to be applicable as a practical method. Thus, it can be concluded that these types of pooled calibration could be used as ‘compromise methods’ that combine both accuracy and usability. 相似文献
15.
Estimating the mass of asteroid 253 mathilde from tracking data during the NEAR flyby 总被引：1，自引：0，他引：1
DK Yeomans J Barriot DW Dunham RW Farquhar JD Giorgini CE Helfrich AS Konopliv JV McAdams JK Miller WM Owen DJ Scheeres SP Synnott BG Williams 《Science (New York, N.Y.)》1997,278(5346):2106-2109
The terminal navigation of the Near Earth Asteroid Rendezvous (NEAR) spacecraft during its close flyby of asteroid 253 Mathilde involved coordinated efforts to determine the heliocentric orbits of the spacecraft and Mathilde and then to determine the relative trajectory of the spacecraft with respect to Mathilde. The gravitational perturbation of Mathilde on the passing spacecraft was apparent in the spacecraft tracking data. As a result of the accurate targeting achieved, these data could be used to determine Mathilde's mass as 1.033 (+/- 0.044) x 10(20) grams. Coupled with a volume estimate provided by the NEAR imaging team, this mass suggests a low bulk density for Mathilde of 1.3 grams per cubic centimeter. 相似文献
16.
NATHAN C. NELSON WM TOD DROST PHILLIP LERCHE JOHN D. BONAGURA 《Veterinary radiology & ultrasound》2010,51(3):313-323
Determination of central venous pressure (CVP) is relevant to patients with right heart disease, hypovolemia, and following intravenous fluid therapy. We hypothesized that changes in CVP in dogs could be predicted by measurements of hepatic vein diameter, caudal vena cava (CVC) diameter, and hepatic venous flow velocities. Nine healthy American Foxhounds were anesthetized. Following baseline recordings, intravenous fluids were administered to increase CVP. Volume administration created treatment periods with CVP ranges of 5, 10, 15, 20, and 25 mm Hg. Flow velocities in the right medial hepatic vein were recorded using pulsed wave Doppler ultrasound. Hepatic vein, CVC, and aorta diameters were determined with B‐mode ultrasound. Variables were compared across the treatment periods by ANOVA for repeated measures. Relationships between CVP, Doppler, and B‐mode variables were evaluated using Spearman's rank correlations, multiple linear regression, and repeated measures linear regression. The a‐, S‐ and v‐wave velocities were augmented significantly with volume loading. The best part (semipartial) correlation coefficients predicting increasing CVP were identified with v‐wave velocity (0.823), S‐wave velocity (?0.800), CVC diameter (0.855), and hepatic vein diameter (0.815). Multiple linear regression indicated that CVP in this study could be predicted best by a combination of CVC and hepatic vein diameter and the v‐wave velocity (r=0.928). Ultrasound imaging identified gallbladder and pancreatic edema consistently, likely related to acute volume loading. These findings may be applicable in the assessment of volume status, dogs with right heart disease, and during serial monitoring of dogs receiving fluid or diuretic therapy. 相似文献
17.
WM Itano JJ Bollinger JN Tan B Jelenkovic X Huang DJ Wineland 《Science (New York, N.Y.)》1998,279(5351):686-689
Single crystals of a one-component plasma were observed by optical Bragg diffraction. The plasmas contained 10(5) to 10(6) single-positive beryllium-9 ions (9Be+) at particle densities of 10(8) to 10(9) per cubic centimeter. In approximately spherical plasmas, single body-centered cubic (bcc) crystals or, in some cases, two or more bcc crystals having fixed orientations with respect to each other were observed. In some oblate plasmas, a mixture of bcc and face-centered cubic ordering was seen. Knowledge of the properties of one-component plasma crystals is required for models of white dwarfs and neutron stars, which are believed to contain matter in that form. 相似文献
18.
Yukio Sugimura Morihide Itano Christine D. Salud Kazuya Otsuji Hirofumi Yamaguchi 《Euphytica》1997,98(1-2):29-35
Botanical and agronomical traits were observed using 39 cultivars of coconut palms which mainly collected in the PhilipApines,
and statistically analyzed to clarify the variation between and within cultivar groups (typica, nana and javanica). Although
there were broad variations in all the traits except for several male flower characters, significant differences among three
cultivars were found in a dozen of traits. The variation within a cultivar group was higher in typica and javanica. Nana was
noted as an aggregate group, which was far distance from typica. Javanica was characterized as the intermediate group having
overlapping boundaries with other groups.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
Chiaverini J Britton J Leibfried D Knill E Barrett MD Blakestad RB Itano WM Jost JD Langer C Ozeri R Schaetz T Wineland DJ 《Science (New York, N.Y.)》2005,308(5724):997-1000
We report the implementation of the semiclassical quantum Fourier transform in a system of three beryllium ion qubits (two-level quantum systems) confined in a segmented multizone trap. The quantum Fourier transform is the crucial final step in Shor's algorithm, and it acts on a register of qubits to determine the periodicity of the quantum state's amplitudes. Because only probability amplitudes are required for this task, a more efficient semiclassical version can be used, for which only single-qubit operations conditioned on measurement outcomes are required. We apply the transform to several input states of different periodicities; the results enable the location of peaks corresponding to the original periods. This demonstration incorporates the key elements of a scalable ion-trap architecture, suggesting the future capability of applying the quantum Fourier transform to a large number of qubits as required for a useful quantum factoring algorithm. 相似文献
20.
Rosenband T Hume DB Schmidt PO Chou CW Brusch A Lorini L Oskay WH Drullinger RE Fortier TM Stalnaker JE Diddams SA Swann WC Newbury NR Itano WM Wineland DJ Bergquist JC 《Science (New York, N.Y.)》2008,319(5871):1808-1812
Time has always had a special status in physics because of its fundamental role in specifying the regularities of nature and because of the extraordinary precision with which it can be measured. This precision enables tests of fundamental physics and cosmology, as well as practical applications such as satellite navigation. Recently, a regime of operation for atomic clocks based on optical transitions has become possible, promising even higher performance. We report the frequency ratio of two optical atomic clocks with a fractional uncertainty of 5.2 x 10(-17). The ratio of aluminum and mercury single-ion optical clock frequencies nuAl+/nuHg+ is 1.052871833148990438(55), where the uncertainty comprises a statistical measurement uncertainty of 4.3 x 10(-17), and systematic uncertainties of 1.9 x 10(-17) and 2.3 x 10(-17) in the mercury and aluminum frequency standards, respectively. Repeated measurements during the past year yield a preliminary constraint on the temporal variation of the fine-structure constant alpha of alpha/alpha = (-1.6+/-2.3) x 10(-17)/year. 相似文献