Angular Spread Analysis and Modeling of UAV Air-to-Ground Channels at 3.5 GHz

2019 ◽  
Author(s):  
Yang Wang ◽  
Ruonan Zhang ◽  
Bin Li ◽  
Xiao Tang ◽  
Dawei Wang
Keyword(s):  
Angular Spread ◽  
Spread Analysis

scholarly journals Complex Network Modelling of Origin–Destination Commuting Flows for the COVID-19 Epidemic Spread Analysis in Italian Lombardy Region

2021 ◽  
Vol 11 (10) ◽  
pp. 4381
Author(s):  
Angela Lombardi ◽  
Nicola Amoroso ◽  
Alfonso Monaco ◽  
Sabina Tangaro ◽  
Roberto Bellotti
Keyword(s):  
Urban Areas ◽  
Large Scale ◽  
Critical Role ◽  
Potential Contribution ◽  
Epidemic Spread ◽  
Network Modelling ◽  
Lombardy Region ◽  
Commuting Flows ◽  
Dynamic Growth ◽  
Spread Analysis

Currently the whole world is affected by the COVID-19 disease. Italy was the first country to be seriously affected in Europe, where the first COVID-19 outbreak was localized in the Lombardy region. The further spreading of the cases led to the lockdown of the most affected regions in northern Italy and then the entire country. In this work we investigated an epidemic spread scenario in the Lombardy region by using the origin–destination matrix with information about the commuting flows among 1450 urban areas within the region. We performed a large-scale simulation-based modeling of the epidemic spread over the networks related to three main motivations, i.e., work, study and occasional transfers to quantify the potential contribution of each category of travellers to the spread of the epidemic process. Our findings outline that the three networks are characterised by different weight dynamic growth rates and that the network “work” has a critical role in the diffusion phenomenon showing the greatest contribution to the epidemic spread.

scholarly journals Angular Spread Quantification of Multi-Antenna Vehicular Radio Communication Channels

2018 ◽  
Author(s):  
Abrar Ahmed ◽  
Syed Junaid Nawaz ◽  
Sardar Muhammad Gulfam ◽  
Shurjeel Wyne ◽  
Mohammad N. Patwary ◽  
...  
Keyword(s):  
Communication Channels ◽  
Angular Spread ◽  
Radio Communication

Scan profiles for neutron spectrometers. II. Rectangular-profile elements by acceptance-diagram methods

2003 ◽  
Vol 36 (5) ◽  
pp. 1214-1224
Author(s):  
L. D. Cussen
Keyword(s):  
Neutron Scattering ◽  
Angular Spread ◽  
Significant Gain ◽  
Angular Divergence ◽  
Rectangular Profile ◽  
Effective Use ◽  
Extended View

The recent development of neutron collimators with rectangular transmission profiles (intensityversusangular divergence) extends hope of improved count rates on neutron scattering instruments. It is usually assumed that a more effective use of beam angular spread in these devices should increase count rates by about a factor of two. However, real beams have both angular and wavevector spread and both these spreads are governed by the allowed collimation. In this extended view, the gains from ideal rectangular-profile elements (angle filters) are shown to be much larger (about a factor of four). The mirror reflections used to achieve the rectangular profiles in real devices complicate the resolution effects. Specifically, the reflections disturb the wavevector–angular divergence correlation in the beams, leading to unusual peak shapes characterized by triple peaks on powder diffractometers. Thus, these reflecting collimators are likely to be universally useful only before the monochromator and immediately preceding the detector, where wavevector–angle correlations have no effect. This reduces the potential gains to a factor of two or so. Note that the gains are as previously expected but for quite different reasons than imagined. This remains a very significant gain in a field where most work is intensity-limited.

scholarly journals OLA1 is responsible for normal spindle assembly and SAC activation in mouse oocytes

2019 ◽  
Author(s):  
Di Xie ◽  
Juan Zhang ◽  
JinLi Ding ◽  
Jing Yang ◽  
Yan Zhang
Keyword(s):  
Spindle Assembly Checkpoint ◽  
Polar Body ◽  
Germinal Vesicle ◽  
Spindle Assembly ◽  
Mouse Oocyte ◽  
Immunofluorescent Staining ◽  
Germinal Vesicle Breakdown ◽  
Oocyte Meiosis ◽  
Polar Body Extrusion ◽  
Spread Analysis

Background. OLA1 is a member of the GTPase protein family, unlike other members, it can bind and hydrolyze ATP more efficiently than GTP. OLA1 participates in cell proliferation, oxidative response and tumorigenesis. However, whether OLA1 is also required for oocyte meiosis is still unknown. Methods. In this study, the localization, expression, and functions of OLA1 in the mouse oocyte meiosis were examined. Immunofluorescent and confocal microscopy were used to explore the location pattern of OLA1 in the mouse oocyte. Moreover, nocodazole treatment was used to confirm the spindle-like location of OLA1 during mouse meiosis. Western blot was used to explore the expression pattern of OLA1 in the mouse oocyte. Microinjection of siRNA was used to explore the OLA1 functions in the mouse oocyte meiosis. In addition, chromosome spreading was used to investigate the spindle assembly checkpoint (SAC) activity. Results. Immunofluorescent staining showed that OLA1 evenly distributed in the cytoplasm at germinal vesicle (GV) stage. After meiosis resumption (GVBD), OLA1 co-localized with spindles, which was further identified by nocodazole treatment experiments. Knockdown of OLA1 impaired the germinal vesicle breakdown progression and finally resulted in a lower polar body extrusion rate. Immunofluorescence analysis indicated that knockdown of OLA1 led to abnormal spindle assembly, which was evidenced by multipolar spindles in OLA1-RNAi-oocytes. After 6 h post-GVBD in culture, an increased proportion of oocyte which has precociously entered into anaphase/telephase I (A/TI) was observed in OLA1-knockdown oocytes, suggesting that loss of OLA1 resulted in the premature segregation of homologous chromosomes. In addition, the chromosome spread analysis suggested that OLA1 knockdown induced premature anaphase onset was due to the precocious inactivation of SAC. Taken together, we concluded that OLA1 plays important role in GVBD, spindle assembly and SAC activation maintenance in oocyte meiosis.

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