scholarly journals 71 The relationships of late gestational uterine artery blood flow with calf and placental size

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 48-49
Author(s):  
Colby A Redifer ◽  
Allison M Meyer
Keyword(s):  
Blood Flow ◽  
Uterine Artery ◽  
Color Doppler ◽  
Correlation Coefficients ◽  
Strong Positive Correlation ◽  
Artery Blood Flow ◽  
Positive Correlation ◽  
Uterine Arteries ◽  
Positive Correlations ◽  
Moderate Positive Correlation

Abstract Utilizing crossbred fall-calving beef females over 2 years, relationships of uterine artery blood flow (UBF) with cow BW, calf birth BW, and placental characteristics were investigated. Transrectal color Doppler ultrasonography of both uterine arteries was conducted, and scans were grouped into 80, 60, 40, and 20 ± 5 d prior to calving (DPC; n = 28, 38, 36, and 24, respectively). Placentas were dissected post-expulsion (n = 21, 26, 26, and 19, respectively). Correlation coefficients were determined for UBF with BW and placental measures at each timepoint. Total UBF had a moderate positive (80, 40, and 20 DPC, P ≤ 0.009) or weak positive correlation (60 DPC, P = 0.02) with calf BW. Calf BW had a moderate positive correlation (P ≤ 0.04) with contralateral UBF (80, 60, and 40 DPC). Cow BW was not correlated (P ≥ 0.07) with UBF. Total and contralateral UBF had moderate positive correlations (P ≤ 0.03) with cotyledonary, intercotyledonary and total placental weights at 40 DPC and with intercotyledonary weight at 20 DPC. Contralateral UBF had a moderate positive correlation (P = 0.03) with total placental weight at 20 DPC. Ipsilateral UBF had no relationship (P ≥ 0.06) with calf or placental weights. Cotyledon number had a moderate negative correlation (P = 0.02) with ipsilateral UBF at 20 DPC, but a moderate (60 and 80 DPC) or strong (20 and 40 DPC) positive correlation (P ≤ 0.05) with contralateral UBF. Average cotyledonary size had a moderate positive correlation (P = 0.01) with total UBF at 20 DPC. Ipsilateral UBF had a moderate (80 and 40 DPC, P ≤ 0.04) or strong positive correlation (20 DPC, P = 0.003) with average cotyledonary size. These data suggest that late gestational UBF drives fetal and placental growth. Interestingly, contralateral UBF may have a disproportionately greater contribution.

scholarly journals 298 Effects of parity on late gestational uterine blood flow and hemodynamics in beef cattle

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 137-138
Author(s):  
Allison M Meyer ◽  
Natalie B Duncan ◽  
Katy S Stoecklein ◽  
Emma L Stephenson
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Birth Weight ◽  
Pulsatility Index ◽  
Uterine Artery ◽  
Color Doppler ◽  
Peak Systolic Velocity ◽  
Late Gestation ◽  
Artery Blood Flow ◽  
Diastolic Velocity

Abstract To determine parity effects on late gestational uteroplacental blood flow, uterine artery hemodynamics were measured in 13 primiparous and 11 multiparous (parity 3 and 4) non-lactating, fall-calving crossbred females beginning 109 d prepartum. Females were nutritionally managed as one group to meet or exceed nutrient requirements. Transrectal color Doppler ultrasonography of the both uterine arteries was conducted 3 to 6 times per female across late gestation, ending at approximately 20 d prepartum. Data were analyzed with parity (primiparous vs. multiparous), day prior to calving, and their interaction in the model; day was a repeated effect. Dam BW was greater (P < 0.001) for multiparous than primiparous females, and increased (P = 0.004) as gestation progressed. Calf birth weight was unaffected (P = 0.87) by parity. The parity x day interaction tended to affect (P = 0.06) ipsilateral uterine artery blood flow (L/min), where multiparous cows had a greater increase per day. Total and contralateral uterine artery blood flow were unaffected (P ≥ 0.11) by parity, but increased (P < 0.001) with day of gestation. When expressed relative to dam BW, total and contralateral blood flow were greater (P ≤ 0.04) in primiparous than multiparous females; ipsilateral blood flow was unaffected (P ≥ 0.13) by parity, however. Ipsilateral pulsatility index and both resistance indices were unaffected (P ≥ 0.28) by parity and day, but day tended to affect (P = 0.07) contralateral pulsatility index. Parity did not affect (P ≥ 0.11) cross-sectional area, mean velocity, peak systolic velocity, and end diastolic velocity of either uterine artery, but all increased (P < 0.001) as gestation progressed. Heart rate was greater (P = 0.03) in primiparous than multiparous females. Data suggest that uterine artery blood flow and heart rate may be altered in primiparous females, even when birth weight is unaffected by parity.

scholarly journals Increased uterine artery blood flow in hypoxic murine pregnancy is not sufficient to prevent fetal growth restriction†

2019 ◽  
Vol 102 (3) ◽  
pp. 660-670 ◽  
Author(s):  
Sydney L Lane ◽  
Alexandrea S Doyle ◽  
Elise S Bales ◽  
Ramón A Lorca ◽  
Colleen G Julian ◽  
...  
Keyword(s):  
Blood Flow ◽  
Fetal Growth ◽  
Murine Model ◽  
Pregnancy Complications ◽  
Fetal Growth Restriction ◽  
Uterine Artery ◽  
Growth Restriction ◽  
Late Gestation ◽  
Artery Blood Flow ◽  
Uterine Arteries

Abstract Incomplete maternal vascular responses to pregnancy contribute to pregnancy complications including intrauterine growth restriction (IUGR) and preeclampsia. We aimed to characterize maternal vascular dysfunction in a murine model of fetal growth restriction as an approach toward identifying targetable pathways for improving pregnancy outcomes. We utilized a murine model of late-gestation hypoxia-induced IUGR that reduced E18.5 fetal weight by 34%. Contrary to our hypothesis, uterine artery blood flow as measured in vivo by Doppler ultrasound was increased in mice housed under hypobaric hypoxia (385 mmHg; 5500 m) vs normoxia (760 mmHg; 0 m). Using wire myography, uterine arteries isolated from hypoxic mice had similar vasodilator responses to the two activators A769662 and acetylcholine as those from normoxic mice, although the contribution of an increase in nitric oxide production to uterine artery vasodilation was reduced in the hypoxic vs normoxic groups. Vasoconstrictor responses to phenylephrine and potassium chloride were unaltered by hypoxia. The levels of activated adenosine monophosphate-activated protein kinase (AMPK) were reduced with hypoxia in both the uterine artery and placenta as measured by western blot and immunohistochemistry. We concluded that the rise in uterine artery blood flow may be compensatory to hypoxia but was not sufficient to prevent fetal growth restriction. Although AMPK signaling was reduced by hypoxia, AMPK was still receptive to pharmacologic activation in the uterine arteries in which it was a potent vasodilator. Thus, AMPK activation may represent a new therapy for pregnancy complications involving reduced uteroplacental perfusion.

48 Transrectal color Doppler evaluation of umbilicus, placentomes, and uterine vascularity changes throughout pregnancy in Surti buffalo

2020 ◽  
Vol 32 (2) ◽  
pp. 149
Author(s):  
M. Gaur ◽  
G. N. Purohit
Keyword(s):  
Blood Flow ◽  
Pulsatility Index ◽  
Uterine Artery ◽  
Color Doppler ◽  
Resistive Index ◽  
Flow Mode ◽  
Adult Age ◽  
Uterine Arteries ◽  
Doppler Evaluation ◽  
Surti Buffalo

With an objective to record the appearance, vascularity changes in umbilicus, placentomes, and blood flow to the uterus, adult (age 5-10 yr) Surti buffalo (parity=2-6; n=24) were inseminated during natural oestrus during the breeding season and scanned by transrectal B mode and colour flow mode ultrasonography every 3-4 days till Day 90 of gestation and then at an interval of 15 days for the complete gestation. The umbilical cord was first visible on Day 38; however, colour Doppler wave fronts could first be obtained on Day 46, which became increasingly distinct thereafter. The placentomes could first be identified at Day 76 of gestation. The placentome diameters increased from Day 76 until the month 7 with significant increases (P<0.05) during Day 80, and months 4, 5, and 6 of gestation; thereafter, the increase was not significant. The vascularity of placentomes could also be recognised at Day 76 and this increased with increasing months of gestation. The blood flow to the middle uterine arteries could be identified after month 2 of gestation. The resistive index values of the middle uterine artery ipsilateral to the gravid horn showed an almost linear decline with a significant (P<0.05) drop at months 4 and 9 of gestation. Similarly, resistive index values of the middle uterine artery contra-lateral to the gravid horn revealed a significant (P<0.05) decrease on month 3, 5, and 6. A significant decrease for pulsatility index values of the middle uterine artery ipsilateral to the gravid horn was observed in months 3, 6, and 8 of gestation. However, the pulsatility index values for the middle uterine artery contralateral to the gravid horn showed a nonsignificant decrease. It was concluded that the umbilicus and placentomes are first visible at 38 and 76 days of gestation and the vascularity of the umbilicus, placentomes, and middle uterine artery increases with advancement of gestation in Surti buffalo.

How Competitive is the Canadian Diagnostic Radiology Residency Match? Application and Matching Trends from 1991-2014

2016 ◽  
Vol 67 (2) ◽  
pp. 105-111 ◽  
Author(s):  
Stephanie A. Kenny ◽  
Kaisra Esmail ◽  
Rebecca M. Hibbert ◽  
Matthew D.F. McInnes
Keyword(s):  
Correlation Coefficients ◽  
Diagnostic Radiology ◽  
Strong Positive Correlation ◽  
Residency Programs ◽  
Positive Correlation ◽  
First Choice ◽  
Radiology Residency ◽  
And Training ◽  
Moderate Positive Correlation ◽  
Over Time

Purpose The study sought to evaluate application trends in Canadian diagnostic radiology residency programs and to assess the relative competitiveness of radiology as a specialty. Methods The Canadian Residency Matching Service Reports from 1991–2014 for Canadian graduates were used to extract the total residency positions and radiology residency positions, number of applicants to all specialties and to radiology, number of first-choice radiology applicants, number of unmatched radiology positions, and number of positions and applicants to each specialty. Ratios were calculated: radiology positions to applicants and first-choice applicants, first-choice radiology applicants to applicants for all specialties, and training positions to applicants in each specialty. Data trends and correlation coefficients were analysed. Results The number of radiology residency positions offered increased, with strong positive correlation (r = 0.91, P < .001), while the number of applicants increased with only a moderate positive correlation (r = 0.49, P = .03). Radiology was the most competitive in 1997, with a ratio of 0.32 positions/applicant. There was an increase of positions/applicant over time (decreasing competitiveness; r = 0.76, P < .001) but no change in positions/first-choice applicant (r = 0.11, P = .65). The highest percentage of applicants who ranked radiology as their first choice was in 2003 at 6.5% with a decrease in this percentage over time (r = −0.36, P = .13). Radiology is moderately competitive for positions/overall applicants and very competitive for positions/first-choice applicants compared to other specialties. Conclusions The number of radiology residency positions has increased while the number of applicants has not grown commensurately. The match was most competitive in 1997, and decreased in subsequent years. Possible reasons include job market, reimbursement, and work environment.

Relationship amongst ResearchGate altmetric indicators and Scopus bibliometric indicators

2015 ◽  
Vol 116 (9/10) ◽  
pp. 564-577 ◽  
Author(s):  
RISHABH SHRIVASTAVA ◽  
Preeti Mahajan
Keyword(s):  
Sample Size ◽  
Correlation Coefficients ◽  
Strong Positive Correlation ◽  
Bibliometric Indicators ◽  
Pearson’S Correlation ◽  
Content Type ◽  
Positive Correlation ◽  
Pearson's Correlation ◽  
Different Characteristics ◽  
The Relationship

Purpose – The purpose of this paper is twofold. First, the study aims to investigate the relationship between the altmetric indicators from ResearchGate (RG) and the bibliometric indicators from the Scopus database. Second, the study seeks to examine the relationship amongst the RG altmetric indicators themselves. RG is a rich source of altmetric indicators such as Citations, RGScore, Impact Points, Profile Views, Publication Views, etc. Design/methodology/approach – For establishing whether RG metrics showed the same results as the established sources of metrics, Pearson’s correlation coefficients were calculated between the metrics provided by RG and the metrics obtained from Scopus. Pearson’s correlation coefficients were also calculated for the metrics provided by RG. The data were collected by visiting the profile pages of all the members who had an account in RG under the Department of Physics, Panjab University, Chandigarh (India). Findings – The study showed that most of the RG metrics showed strong positive correlation with the Scopus metrics, except for RGScore (RG) and Citations (Scopus), which showed moderate positive correlation. It was also found that the RG metrics showed moderate to strong positive correlation amongst each other. Research limitations/implications – The limitation of this study is that more and more scientists and researchers may join RG in the future, therefore the data may change. The study focuses on the members who had an account in RG under the Department of Physics, Panjab University, Chandigarh (India). Perhaps further studies can be conducted by increasing the sample size and by taking a different sample size having different characteristics. Originality/value – Being an emerging field, not much has been conducted in the area of altmetrics. Very few studies have been conducted on the reach of academic social networks like RG and their validity as sources of altmetric indicators like RGScore, Impact Points, etc. The findings offer insights to the question whether RG can be used as an alternative to traditional sources of bibliometric indicators, especially with reference to a rapidly developing country such as India.

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