migration distance
Recently Published Documents


TOTAL DOCUMENTS

175
(FIVE YEARS 45)

H-INDEX

21
(FIVE YEARS 3)

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Mariëlle L. van Toor ◽  
Sergey Kharitonov ◽  
Saulius Švažas ◽  
Mindaugas Dagys ◽  
Erik Kleyheeg ◽  
...  

Abstract Background The timing of migration for herbivorous migratory birds is thought to coincide with spring phenology as emerging vegetation supplies them with the resources to fuel migration, and, in species with a capital breeding strategy also provides individuals with energy for use on the breeding grounds. Individuals with very long migration distances might however have to trade off between utilising optimal conditions en route and reaching the breeding grounds early, potentially leading to them overtaking spring on the way. Here, we investigate whether migration distance affects how closely individually tracked Eurasian wigeons follow spring phenology during spring migration. Methods We captured wigeons in the Netherlands and Lithuania and tracked them throughout spring migration to identify staging sites and timing of arrival. Using temperature-derived indicators of spring phenology, we investigated how maximum longitude reached and migration distance affected how closely wigeons followed spring. We further estimated the impact of tagging on wigeon migration by comparing spring migratory timing between tracked individuals and ring recovery data sets. Results Wigeons migrated to locations between 300 and 4000 km from the capture site, and migrated up to 1000 km in a single day. We found that wigeons migrating to more north-easterly locations followed spring phenology more closely, and increasingly so the greater distance they had covered during migration. Yet we also found that despite tags equalling only around 2% of individual’s body mass, individuals were on average 11–12 days slower than ring-marked individuals from the same general population. Discussion Overall, our results suggest that migratory strategy can vary dependent on migration distance within species, and even within the same migratory corridor. Individual decisions thus depend not only on environmental cues, but potentially also trade-offs made during later life-history stages.


2021 ◽  
Author(s):  
Kang Zhong ◽  
Xingwang Zhu ◽  
Jinman Yang ◽  
Zhao Mo ◽  
Junchao Qian ◽  
...  

Abstract Photocatalytic conversion of carbon dioxide into fuels and valuable chemicals is a promising method for carbon neutralization and solving environmental problems. Through a simple thermal-oxidative exfoliated method, the O element was doped while exfoliated bulk g-C3N4 into ultrathin structure g-C3N4. Benefitting from the ultrathin structure of g-C3N4, the larger surface area and shorter electrons migration distance effectively improve the CO2 reduction efficiency. In addition, density functional theory computation proves that O element doping introduces new impurity energy levels, which making electrons easier to be excited. The prepared photocatalyst reduction of CO2 to CO (116 μmol g−1 h−1) and CH4 (47 μmol g−1 h−1).


2021 ◽  
pp. 1-56
Author(s):  
Chong Feng ◽  
Guoxiang Wang ◽  
Jingyuan Zhang ◽  
Junwei Wang ◽  
Mingze Ma ◽  
...  

There is a starting pressure gradient (SPG) for oil migration in tight reservoirs (TRs), and the SPG and the migration force jointly control the migration distance of oil. The key factor of oil accumulation in the tight glutenite reservoir (TGR) of the Lower Triassic Baikouquan Formation (T1 b) in the Mahu Sag is whether the oil can be laterally charged into the TRs. To analyze the lateral migration distances of oil in TRs and predict the favorable accumulation areas for oil, we have carried out a physical simulation experiment of oil charging on glutenite reservoirs of T1 b for obtaining the SPG of oil migration and knowing the relationship between SPGs and the reservoirs’ physical property. According to the basin simulation, we have obtained the pressure evolution of the source rock formation as well as reservoir formation and the physical property evolution of the reservoir. Finally, we have predicated the favorable oil accumulation areas through calculating the distribution characteristics of SPGs as well as the theoretical distances of lateral migration of oil during the key oil accumulation period and considering the theoretical distance of the lateral migration of oil as the main controlling factor. Our results suggest that there is a SPG in the TGR of the T1 b and that there is a power function relationship between the SPG and the permeability. The theoretical lateral migration distance of oil in T1 b during the key oil accumulation period was the farthest in the northern sag, which was gradually shortened to the east, west, and south. In class I favorable areas, the reservoirs have good physical properties where overpressure has developed; in addition, the lateral migration distance of oil is far. Therefore, these are the most favorable areas for oil accumulation.


Author(s):  
Benjamin M Winger ◽  
Teresa M Pegan

Abstract Seasonal migration is intrinsically connected to the balance of survival and reproduction, but whether migratory behavior influences species’ position on the slow-fast continuum of life history is poorly understood. We found that boreal-breeding birds that migrate long distances exhibit higher annual adult survival and lower annual reproductive investment relative to co-distributed boreal species that migrate shorter distances to winter closer to their breeding grounds. Our study uses “vital rates” data on reproductive output and survivorship compiled from the literature for a species assemblage of 45 species of mostly passerine birds. These species breed sympatrically in North American boreal forests but migrate to a diversity of environments for the northern winter. After controlling for body size and phylogeny, migration distance and apparent annual adult survival are positively related across species. Both migration distance and survival are positively correlated with wintering in environments that are warmer, wetter, and greener. At the same time, longer migrations are associated with reduced time spent on the breeding grounds, lower clutch sizes, and lower fecundity (clutch size × maximum number of broods per year). Although seasonal migration is often associated with high mortality, our results suggest that long-distance migration imposes selection pressures that both confer and demand high adult survival rates. That is, owing to the reproductive cost of long-distance migration, this strategy can only persist if balanced by high adult survival. Our study supports the idea that migration evolves to promote survival of species breeding in seasonal environments. In boreal birds, the evolution of the longest migrations yields the highest survival, but at an inherent cost to annual fecundity. Our results therefore reveal migratory distance as a fundamental axis of the slow-fast continuum that predicts, and is inextricable from, the balance of survival and reproduction.


Author(s):  
Seydou Golo Barro ◽  
Faouziatou Bance ◽  
Amadou Dicko ◽  
Michel Gomgnibou ◽  
Pascal Staccini

The analysis of Mycobacterial Interpersed Repetitive Unit-Variable Number of Tandem Repeat (MIRU-VNTR) discriminates against the species of M. tuberculosis involved in the transmission of the disease. The reference method is the manual method. Our study involved developing a bioinformatics method of interpreting MIRU-VNTR and comparing it to the manual method. For this we used two softwares, namely imagej and Microsoft Excel. Imagej was used to determine the migration distance of the bands and for the measure of size in a base pair. The number of repetitions of 18 markers used was analyzed with Excel macro. The results obtained were: 27% of the results exactly consistent, 16% of outliers generated by the macro and 57% of the results not matching.


Author(s):  
Jinxiang Piao ◽  
Chaeyoung Yoo ◽  
SunYoung Kim ◽  
Youn-Wha Whang ◽  
Sehyun Shin ◽  
...  

BACKGROUND: Analyzing responsiveness to P2Y12 therapy is vital to preventing thrombotic and hemorrhagic complications in patients with cardiovascular diseases. OBJECTIVE: This study evaluates a new Anysis-P2Y12 assay system against VerifyNow-P2Y12 in cardiac patients and analyzes the P2Y12 low-response rates of the two devices with various cutoff values. METHODS: In total, 125 citrated blood samples were collected from cardiac patients referred for a P2Y12 antiplatelet response test. In the Anysis assay, the test result was the migration distance (MD) until the blood flow stops, which is comparable to both P2Y12 reaction units and percent inhibition obtained using VerifyNow. RESULTS: The MDs without and with P2Y12 were 182±30 and 264±12 mm, respectively (p <  0.0001). Compared to VerifyNow-P2Y12, the sensitivity and specificity of Anysis-200 were 96.8%and 88.7%, respectively. Cohen’s kappa coefficient between the two devices was 0.761, indicating a high agreement. However, there was an apparent difference in the low-response rate to P2Y12, which was 36.5%for VerifyNow and 5.9%for Anysis. CONCLUSIONS: The performance of the newly developed platelet function assay, Anysis-P2Y12 was equivalent to that of VerifyNow-P2Y12 in terms of sensitivity and specificity. The Anysis-P2Y12 assay may help screen patients with abnormal P2Y12 non-responsiveness.


Author(s):  
Brian Stahl ◽  
Yufeng Li ◽  
Brittany Hermecz ◽  
Stefanie Woodard

Abstract Objective The purpose of this study was to investigate four commonly used stereotactic biopsy markers, two older and two newer generation, assessing percentage migration and factors influencing migration distance. Methods This was an IRB–approved retrospective review of upright stereotactic breast biopsies from May 2018 to May 2020 involving either older (Cork, Hourglass) or newer (Vision, X-shaped) generation markers. Markers were assessed for migration rate by two-sample Z-test and migration distance by analysis of variance. Univariate analysis was used to assess relationships between marker type and generation, patient characteristics, breast composition and thickness, procedure techniques, trainee involvement, and complications, correlating with migration distance. Multivariable analysis was performed for variables with P-value &lt; 0.1 on univariate analysis. Tukey’s test was used to compare all groups (P &lt; 0.05). Results A total of 732 stereotactic biopsies were performed with 508 using a Cork, Hourglass, Vision, or X-shaped marker. Overall migration rate was 181/508 (35.6%) with no difference between markers. Breast thickness and density were negatively associated with migration distance in univariate analysis. Older marker migration distance was greater than newer (2.6 cm vs 1.9 cm, respectively), which was significant after adjusting for breast thickness and density (P = 0.037). Density was a significant factor in migration distance, comparing fatty to nonfatty breasts (P &lt; 0.05) in univariate analysis. Conclusion No difference in migration rate was seen between the four biopsy markers. Vision and X-shaped markers demonstrate lower migration distance than Cork and Hourglass in multivariate analysis. There is an inverse relationship between breast density and marker migration distance.


Sign in / Sign up

Export Citation Format

Share Document