3,436 research outputs found

    Sex Differences in the Superficial Femoral Artery Occlusion Pressure

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    The measurement of arterial occlusion pressure (AOP) prior to the use of blood flow restriction during exercise is recommended. Not all previous studies that have included both male and female participants have reported sex differences in AOP. PURPOSE: The purpose of this study was to compare the superficial femoral artery AOP of the dominant and non-dominant legs between males and females. METHODS: Ultrasound (GE LOGIQ) was used to detect blood flow through the superficial femoral artery of both legs in a random order in 20 males and 20 females. Circumference of the upper thigh, leg volume, and skinfold thickness were measured in both legs. Blood pressure was continuously monitored using a CNAP device. An inflatable cuff was placed around the upper thigh. The cuff was inflated to 50 mmHg and then inflated continuously (10 mmHg/10 s) until arterial blood flow and pulse waves were no longer detectable by the ultrasound. The AOP was then measured in the opposite leg. The AOP data were analyzed with a mixed model analysis of variance while maintaining a family-wise p-value of 0.05. RESULTS: The AOP of the dominant leg in males (209.4 ± 29.4 mmHg) and females (212.3 ± 8.3 mmHg) were not significantly different (p=0.844). Likewise, the AOP of the non-dominant leg in males (206.8 ± 32.5 mmHg) was not significantly different (p=0.804) than the AOP in the non-dominant legs of females (203.5 ± 50.9 mmHg). When combining the data for the dominant and non-dominant legs, the average AOP for males (208.1 ± 30.6 mmHg) and females (207.9 ± 53.1 mmHg) were not significantly different (p=0.986). Thigh circumference was the only variable that significantly (p=0.027) contributed to AOP. On the average the thigh circumference in the dominant and non-dominant legs of males (59.6 ± 5.5; 59.2 ± 5.2 cm) was greater than that for females (56.0 ± 2.9; 55.6 ± 3.2 cm), respectively. There were no sex differences in thigh skinfold thickness or thigh volume between males and females in either the dominant or non-dominant legs. CONCLUSION: There were no significant differences in AOP of the superficial femoral artery of the dominant and non-dominant legs between males females despite males having larger legs. Factors other than limb circumference likely have a role in determining AOP

    Differences in Arterial Occlusion Pressure of the Superficial Femoral Artery Between the Dominant and Non-Dominant Legs

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    The arterial occlusion pressure (AOP) is dependent on limb circumference. Previous research seldom reports the AOP of both limbs. PURPOSE: The purpose of this study was to compare the superficial femoral artery AOP measured in the dominant and non-dominant legs. METHODS: Ultrasound (GE LOGIQ) was used to detect blood flow through the superficial femoral artery of both legs in a random order in 20 males and 20 females. Circumference of the upper thigh, leg volume, and skinfold thickness were measured in both legs. Blood pressure was continuously monitored using a CNAP device. An inflatable cuff was placed around the upper thigh. The cuff was inflated to 50 mmHg and then inflated continuously (10 mmHg/10 s) until arterial blood flow and pulse waves were no longer detectable by the ultrasound. The AOP was then measured in the opposite leg. The AOP data were analyzed with a mixed model analysis of variance while maintaining a family-wise p-value of 0.05. RESULTS: In males, the AOP of the dominant (209.4 ± 29.4 mmHg) and non-dominant legs (206.8 ± 32.5 mmHg) were not significantly different (p=0.790). Likewise, in females the AOP of the dominant (212.3 ± 58.3 mmHg) and non-dominant legs (203.5 ± 50.9 mmHg) were not significantly different (p=0.386). When combining the data for males and females, the AOP of the dominant (210.9 ± 45.6 mmHg) and non-dominant legs (205.2 ± 40.7 mmHg) were not significantly different (p=0.412). Thigh circumference was the only variable that significantly (p=0.027) contributed to AOP. In both males and females, there were no differences in thigh skinfold thickness, circumference, and volume between the dominant and non-dominant legs. The dominant leg was larger in 24 (60%) of the subjects; the larger leg had a higher AOP in 19 (47.5%) of the subjects; and the dominant leg had a higher AOP in 26 (65%) of the subjects. Although the AOP between the dominant and nondominant legs was not statistically significant, the largest difference in AOP between the two legs was 124 mmHg. CONCLUSION: There were no significant differences in AOP of the superficial femoral artery between the dominant and non-dominant legs in either males or females. Because of the potentially larger differences in the AOP between the two legs, we recommend measuring the AOP in both limbs when using blood flow restriction during exercise

    Bayesian High-Redshift Quasar Classification from Optical and Mid-IR Photometry

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    We identify 885,503 type 1 quasar candidates to i<22 using the combination of optical and mid-IR photometry. Optical photometry is taken from the Sloan Digital Sky Survey-III: Baryon Oscillation Spectroscopic Survey (SDSS-III/BOSS), while mid-IR photometry comes from a combination of data from the Wide-Field Infrared Survey Explorer (WISE) "ALLWISE" data release and several large-area Spitzer Space Telescope fields. Selection is based on a Bayesian kernel density algorithm with a training sample of 157,701 spectroscopically-confirmed type-1 quasars with both optical and mid-IR data. Of the quasar candidates, 733,713 lack spectroscopic confirmation (and 305,623 are objects that we have not previously classified as photometric quasar candidates). These candidates include 7874 objects targeted as high probability potential quasars with 3.5<z<5 (of which 6779 are new photometric candidates). Our algorithm is more complete to z>3.5 than the traditional mid-IR selection "wedges" and to 2.2<z<3.5 quasars than the SDSS-III/BOSS project. Number counts and luminosity function analysis suggests that the resulting catalog is relatively complete to known quasars and is identifying new high-z quasars at z>3. This catalog paves the way for luminosity-dependent clustering investigations of large numbers of faint, high-redshift quasars and for further machine learning quasar selection using Spitzer and WISE data combined with other large-area optical imaging surveys.Comment: 54 pages, 17 figures; accepted by ApJS Data for tables 1 and 2 available at http://www.physics.drexel.edu/~gtr/outgoing/optirqsos/data/master_quasar_catalogs.011414.fits.bz2 and http://www.physics.drexel.edu/~gtr/outgoing/optirqsos/data/optical_ir_quasar_candidates.052015.fits.bz

    Movements of Spawning and Non-Spawning Shovelnose Sturgeon in the Missouri River Above Fort Peck Reservoir

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    During the last 40 yrs there has been a lack of pallid sturgeon (Scaphirhynchus albus) recruitment in the upper Missouri River (UMR). However, shovelnose sturgeon (Scaphirhynchus platorynchus) continue to exhibit recruitment in the UMR. Understanding the recruitment dichotomy between species is receiving much attention throughout their range. The objectives of this study were to identify the effects of varying discharge on spawning locations and spawning movements for pallid and shovelnose sturgeon. Two female pallid sturgeon, 32 gravid female shovelnose sturgeon, and 32 non-reproductively active female shovelnose sturgeon were radio tagged at three locations and tracked from 1 May to 5 July 2009. Unfortunately, no data are available for spawning pallid sturgeon movements because fish were not reproductively active. Upstream movement by gravid shovelnose sturgeon varied from 20 percent of the fish tagged at Judith Landing to 56 percent of the fish tagged at Coal Banks Recreation Area (CBRA). Mean maximum upstream movement of gravid shovelnose sturgeon varied from 35.7 km at CBRA to 87.9 km at Fred Robinson Bridge (FRB), mean maximum downstream movement varied from 24.9 km at FRB to 80.3 km at CBRA. Reproductively inactive shovelnose sturgeon exhibited lower mean maximum movements than reproductively active fish (mean maximum distance 5.7 km). Shovelnose sturgeon in the UMR exhibit both upstream and downstream movements prior to spawning and are using several spawning areas. Thus, maintaining spawning habitat throughout a regulated river is important with regard to shovelnose sturgeon conservation

    Differences in Arterial Occlusion Pressure Using Two Different Cuff Inflation Protocols

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    The occlusion pressure used during blood flow restriction during exercise is based on the arterial occlusion pressure (AOP). Although previous studies have measured AOP using two different cuff inflation protocols, no studies have compared the AOP measured using both protocols. PURPOSE: The purpose of this study was to compare the superficial femoral artery AOP when measured using two different cuff inflation protocols. METHODS: Ultrasound (GE LOGIQ) was used to detect blood flow through the superficial femoral artery of both legs in 20 males and 20 females. An inflatable cuff was placed on the upper thigh. The superficial femoral artery was occluded using two different cuff inflation protocols in a random order in both legs. The continuous (CONT) protocol involved inflating the cuff to 50 mmHg then continuously inflating the cuff at a rate of 10 mmHg/10 s until blood flow could no longer be detected using the ultrasound. The incremental (INCR) protocol involved inflating the cuff to 50 mmHg for 30 s, and then deflating the cuff for 10 s. The cuff was then inflated incrementally with each subsequent inflation increasing by 30 mmHg for 30 s followed by deflating the cuff for 10 s. Once blood flow was occluded, cuff pressure was decreased in increments of 10 mmHg until there was evidence of blood flow. The cuff was then gradually inflated until blood flow was no longer detected. RESULTS: In males, the AOP measured in the dominant (209.4 ± 29.4; 208.2 ± 27.1) and non-dominant (206.8 ± 32.5; 206.2 ± 32.7) legs using the CONT and INCR cuff inflation protocols, respectively, were not significantly different (p\u3e0.05). Likewise, in females the AOP measured in the dominant (212.3 ± 58.3; 213.7 ± 53.9) and non-dominant (203.5 ± 50.9; 207.0 ± 50.2) legs using the CONT and INCR protocol, respectively, were not significantly different (p\u3e0.05). When combining male and female data, there were no significant differences in the AOP between the CONT and INCR cuff inflation protocols in either leg or when combining legs. CONCLUSION: Using a continuous or incremental protocol for occluding the superficial femoral artery resulted in similar AOP values. Either protocol can be used in future research as well as in settings where AOP is determined prior to the use of blood flow restriction during exercise

    Differences in Arterial Occlusion Pressure as Measured using Ultrasound and a Hand-Held Doppler Device

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    In the research lab and clinical settings, expensive ultrasound machines are used to measure arterial occlusion pressure (AOP) prior to the use of blood flow restriction during exercise. Alternatively, inexpensive hand-held Doppler ultrasound devices may be used to measure AOP in various applications and settings. PURPOSE: The purpose of this study was to compare the superficial femoral artery AOP as measured using ultrasound and a hand-held Doppler device. METHODS: Participants included 20 males and 20 females. An inflatable cuff was placed on the upper thigh. The superficial femoral artery was occluded by inflating the cuff to 50 mmHg then continuously inflating the cuff at a rate of 10 mmHg/10 s. A GE LOGIQ ultrasound was used to detect blood flow in the superficial femoral artery just below the cuff. A hand-held Doppler device was used simultaneously to detect blood flow (pulse waves) at the anterior medial malleolar artery of the ankle. The pressure at which blood flow could no longer be detected using the ultrasound and the hand-held Doppler were recorded as the AOP. The measurement of AOP using both devices simultaneously was performed on both legs in a random order. The data were analyzed with a mixed model analysis of variance while maintaining a family-wise p-value of 0.05. RESULTS: On the average, the AOP measured using the hand-held Doppler device was significantly (pCONCLUSION:Although the differences in the AOP measured using the Ultrasound and the hand-held Doppler in both legs in males and females was statistically significant, for all practical purposes, the small differences were of not practical importance. In settings in which blood flow restriction during exercise is employed, a hand-held Doppler device is a viable alternative to using expensive ultrasound machines to measure AOP

    Reliability of Arterial Occlusion Pressure Measurements Using Two Different Cuff Inflation Protocols

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    Although previous studies have used two different cuff inflation protocols to measure AOP, no studies have reported the reliability of AOP measurements using both protocols. PURPOSE: The purpose of this study was to evaluate the reliability of two measurements of AOP in the superficial femoral artery using two different cuff inflation protocols. METHODS: Ultrasound (GE LOGIQ) was used to detect blood flow through the superficial femoral artery of both legs in 20 males and 20 females. The AOP of the artery was measured twice in each leg. The artery was occluded using a continuous (CONT) cuff inflation protocol in one leg and an increment (INCR) cuff inflation protocol in the opposite leg. The CONT protocol involved inflating the cuff to 50 mmHg then continuously inflating the cuff at a rate of 10 mmHg/10 s until blood flow could no longer be detected using the ultrasound. The INCR protocol involved initially inflating the cuff to 50 mmHg for 30 s, and then deflating the cuff for 10 s. The cuff was then inflated incrementally with each subsequent inflation increasing by 30 mmHg for 30 s followed by deflating the cuff for 10 s. Once blood flow was occluded, cuff pressure was decreased in increments of 10 mmHg until there was evidence of blood flow. The cuff was then gradually inflated until blood flow was no longer detected. The pressure at which blood flow could no longer be detected was recorded as the AOP. The data were analyzed with a mixed model analysis of variance while maintaining a family-wise p-value of 0.05. RESULTS: The difference in the two measurements of AOP using the CONT and INCR cuff inflation protocols in males (0.9 ± 5.4 and 0.5 ± 5.1 mmHg) and females (1.9 ± 11.4 and 2.3 ± 12.2 mmHg), or when combining the data from males and females (0.4 ± 8.9 and 0.9 ± 9.3 mmHg), respectively, were not statistically significant. The correlations between the two measurements of AOP using the CONT and INCR cuff inflation protocols all exceeded 0.99. CONCLUSION: Measurements of AOP using a continuous or increment cuff inflation protocol are highly reliable. Either cuff inflation protocol can be used when making multiple measurements of AOP

    Measuring Brachial Artery Occlusion Pressure Using a Hand-held Doppler and Pulse Oximeter

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    The measurement of arterial occlusion pressure (AOP) is recommended for the safe and effective use of blood flow restriction (BFR) during training. PURPOSE: This study compared measurements of brachial artery AOP using Doppler ultrasound (US), a hand-held Doppler (HHDOP) and a pulse oximeter (PO). METHODS: The AOP of the brachial artery was measured simultaneously using US, HHDOP, and a PO in the dominant arm of males (n=36) and females (n=49). The blood flow restriction cuff was inflated using a continuous cuff inflation protocol. RESULTS: A mixed model ANOVA revealed small but significant (p \u3c 0.05) overall main effects (combined males and females) between AOP measured using US (119.8 ± 13.2 mmHg), HHDOP (119.1 ± 13.1 mmHg) and PO (118.0 ±13.2 mmHg), and between males (125.3 ± 13.1 mmHg) and females (114.3 ± 11.1 mmHg). The differences in AOP between males and females was consistent across all three methods of measuring AOP (US, HHDP, PO) and may be attributed to sex differences in limb circumference and systolic blood pressure. The small overall difference between US and HHDOP (0.74 ± 2.7 mmHg) was not significant but the difference between US and PO (1.81 ± 3.3 mmHg) measures of AOP was significant (

    A Spectroscopic Survey of Faint Quasars in the SDSS Deep Stripe: I. Preliminary Results from the Co-added Catalog

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    In this paper we present the first results of a deep spectroscopic survey of faint quasars in the Sloan Digital Sky Survey (SDSS) Southern Survey, a deep survey carried out by repeatedly imaging a 270 deg^2 area. Quasar candidates were selected from the deep data with good completeness over 0<z<5, and 2 to 3 magnitudes fainter than the SDSS main survey. Spectroscopic follow-up was carried out on the 6.5m MMT with Hectospec. The preliminary sample of this SDSS faint quasar survey (hereafter SFQS) covers ~ 3.9 deg^2, contains 414 quasars, and reaches g=22.5. The overall selection efficiency is ~ 66% (~ 80% at g<21.5); the efficiency in the most difficult redshift range (2<z<3) is better than 40%. We use the 1/V_{a} method to derive a binned estimate of the quasar luminosity function (QLF) and model the QLF using maximum likelihood analysis. The best model fits confirm previous results showing that the QLF has steep slopes at the bright end and much flatter slopes (-1.25 at z<2.0 and -1.55 at z>2.0) at the faint end, indicating a break in the QLF slope. Using a luminosity-dependent density evolution model, we find that the quasar density at M_{g}<-22.5 peaks at z~2, which is later in cosmic time than the peak of z~2.5 found from surveys of more luminous objects. The SFQS QLF is consistent with the results of the 2dF QSO Redshift Survey, the SDSS, and the 2dF-SDSS LRG and QSO Survey, but probes fainter quasars. We plan to obtain more quasars from future observations and establish a complete faint quasar sample with more than 1000 objects over 10 deg^2.Comment: 25 pages, 13 figures, accepted for publication in A

    The interactive effects of fertiliser nitrogen with dung and urine on nitrous oxide emissions in grassland

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    The authors wish to thank the Environmental Protection Agency for funding support under the Environmental Research Technological Development and Innovation programme and the Irish Department of Agriculture, Food and the Marine for funding support (Grant numbers RSF 13S430 and 11S138).peer-reviewedNitrous oxide (N2O) is an important and potent greenhouse gas (GHG). Although application of nitrogen (N) fertiliser is a feature of many grazing systems, limited data is available on N2O emissions in grassland as a result of the interaction between urine, dung and fertiliser N. A small plot study was conducted to identify the individual and interactive effects of calcium ammonium nitrate (CAN) fertiliser, dung and urine. Application of CAN with dung and urine significantly increased the mass of N2O-N emission. Importantly, the sum of N2O-N emitted from dung and CAN applied individually approximated the emission from dung and CAN fertiliser applied together, that is, an additive effect. However, in the case of urine and CAN applied together, the emission was more than double the sum of the emission from urine and CAN fertiliser applied individually, that is, a multiplicative effect. Nitrous oxide emissions from dung, urine and fertiliser N are typically derived individually and these individual emission estimates are aggregated to produce estimates of N2O emission. The presented findings have important implications for how individual emission factors are aggregated; they suggest that the multiplicative effect of the addition of CAN fertiliser to urine patches needs to be taken into account to refine the estimation of N2O emissions from grazing grasslands.The authors wish to thank the Environmental Protection Agency for funding support under the Environmental Research Technological Development and Innovation programme and the Irish Department of Agriculture, Food and the Marine for funding support (Grant numbers RSF 13S430 and 11S138)
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