3,863 research outputs found
Ovarian Follicular Dynamics during the Estrous Cycle in Jennies in Upper Egypt
The objective of the current study was to describe follicular dynamics in Egyptian Jennies throughout the estrous cycle. In this experiment, 8 estrus cycles in 8 cyclic Jennies were studied from February to June using ultrasonography. The result revealed that one follicular wave per cycle was recorded throughout the studied period. Dominant follicle (DF) was firstly detected at −0.80 ± 0.84 day in Jennies. The growth rate of DF was 2.32 ± 0.18 mm/day. Left ovulations were nonsignificantly (P = .07) more than right ovulations (55.6% versus 44.6%). The CL was firstly detected at D 2.58 ± 1.2, developed in a rate of 1.19 ± 0.07 mm/day, reached a maximum diameter of 30.77 ± 1.28 mm at D 13.0 ± 0.70, and started to regress on D 17.05 ± 0.64 with a mean regression rate of 1.75 ± 0.17 mm d−1. Results of the present study indicated that Jennies had one follicular wave per cycle. The Day of the cycle has a significant effect on the number of different classes of the ovarian follicles, but not large ones. Ultrasonographic characteristics of the preovulatory follicles could be useful to predict ovulation. CL developed and regressed in a slow rate
The Coulomb phase shift revisited
We investigate the Coulomb phase shift, and derive and analyze new and more
precise analytical formulae. We consider next to leading order terms to the
Stirling approximation, and show that they are important at small values of the
angular momentum and other regimes. We employ the uniform approximation.
The use of our expressions in low energy scattering of charged particles is
discussed and some comparisons are made with other approximation methods.Comment: 13 pages, 5 figures, 1 tabl
Point-of-care diagnostics of covid-19: From current work to future perspectives
Coronaviruses have received global concern since 2003, when an outbreak caused by SARS‐CoV emerged in China. Later on, in 2012, the Middle‐East respiratory syndrome spread in Saudi Arabia, caused by MERS‐CoV. Currently, the global crisis is caused by the pandemic SARS‐ CoV‐2, which belongs to the same lineage of SARS‐CoV. In response to the urgent need of diagnostic tools, several lab‐based and biosensing techniques have been proposed so far. Five main areas have been individuated and discussed in terms of their strengths and weaknesses. The cell‐culture detection and the microneutralization tests are still considered highly reliable methods. The genetic screening, featuring the well‐established Real‐time polymerase chain reaction (RT‐PCR), represents the gold standard for virus detection in nasopharyngeal swabs. On the other side, immunoassays were developed, either by screening/antigen recognition of IgM/IgG or by detecting the whole virus, in blood and sera. Next, proteomic mass‐spectrometry (MS)‐based methodologies have also been proposed for the analysis of swab samples. Finally, virus-biosensing devices were efficiently designed. Both electrochemical immunosensors and eye‐based technologies have been described, showing detection times lower than 10 min after swab introduction. Alternative to swab‐based techniques, lateral flow point‐of‐care immunoassays are already commercially available for the analysis of blood samples. Such biosensing devices hold the advantage of being portable for on‐site testing in hospitals, airports, and hotspots, virtually without any sample treatment or complicated lab precautions
Impact of planting dates and some weather factors on population fluctuation and occurrence percentage of aphids and thrips on wheat crop in Egypt
Three planting dates of wheat (Nov., 15th, Dec., 1st and Dec., 15th ) were evaluated during 2012/ 2013 and 2013/2014 seasons at Al Ziton village, Beni-Suief Governorate to determine their effect on the population fluctuation of aphids; Rhopalosiphum padi, Schizaphis graminum, Rhopalosiphum maidis and Sitobion (Macrosiphum) avenae and thrips; Thrips tabaci. Results indicated that planting of wheat seeds in the second planting date (Dec., 1st) led to slight infestation of aphids and thrips with mean numbers of 15.52 and 5.74 individuals /10 tillers, for the two seasons. The population fluctuation of aphids and thrips were affected by delaying planting date, as the wheat plants planted at the early planting date (Nov., 15th) were found to be infested by a little numbers of aphids in the first inspection. On the contrary, the infestation of aphids postponed for 8 and 2 weeks & 8 and 6 weeks in the second and third planting dates in the two studied seasons, respectively. On the other hand, the infestation of thrips postponed for 3 & 1 weeks and 6 & 4 weeks in the second and third planting dates in the two seasons, respectively. The highest infestation rate of aphids on wheat plants were recorded at the last period of growth (ear head formation) in the three tested planting dates as the occurrence percent were 48.57, 87.55 and 76.06 % for the three planting dates, in the first season and were 92.94, 89.02 and 88.71 % in the second season. The highest infestation rate of thrips occurred during tillering stage in the 1st and 2nd planting dates, as occurrence percent were 76.58 and 78.69 % in the first season and 91.09 & 86.67 % in the second season. On the other hand, the highest infestation rate of thrips at the 3rd planting date were recorded during the ear head formation, showing occurrence percent of 94.84 and 91.15 % in the two seasons, respectively. The population density of aphids and thrips were greatly influenced according to the change in weather factors. The combined effect of temperature and relative humidity on the population density of aphids on wheat plants were 20.44, 37.53 and 30.12 for the three tested planting dates, in the first season and were 27.39, 25.65 and 25.81 % in the second seasons, respectively. The combined effect of two climatic factors together on the population density thrips decreased by delaying planting date of wheat, as E.V.% were 90.52, 35.04 and 28.34 % to the three tested planting dates in the first season and 54.68, 51.28 and 31.04 in the second season, respectively.
Interplay of static and dynamic effects in 6He+ 238U Fusion
We investigate the influence of the neutron halo and the breakup channel in
6He + 238U fusion at near-barrier energies. To include static effects of the
2n-halo in 6He nuclei, we use a single-folding potential obtained from an
appropriate nucleon-238U interaction and a realistic 6He density. Dynamical
effects arising from the breakup process are then included through
coupled-channel calculations. These calculations suggest that static effects
dominate the cross section at energies above the Coulomb barrier, while the
sub-barrier fusion cross section appears to be determined by coupling to the
breakup channel. This last conclusion is uncertain due to the procedure
employed to measure the fusion cross-section.Comment: 13 pages, 4 figure
The Effect of Collimator Diameters on Buildup Factor by using Gamma – Gamma Coincidence System
In this work buildup factor of aluminum and copper samples was studied for different thickness using a gamma _ gamma coincidence technique and by use two collimator 10 and 7 mm, buildup factor was calculated for thickness ranged between ( 0 - 9.6 ) cm of aluminum and ( 0 - 4.0 ) cm of copper using Na - 22 source with activity of ( 1 micro Curie ) with single energy ( 0.511 MeV ) and by using ( 3 "× 3" ) sodium iodide detector NaI (TI). The results showed that buildup factor was more accuracy when we used small diameter because this will decrease the scattering ray which make our calculations more acute for buildup factor which is very important in shielding process for gamma ray. Keywords: Buildup factor, Gamma ray, Shield, Coincidence
User friendly system for the visually impaired in learning Al-Quran
This study presents a method to enable the visually impaired Muslim to learn and read the Al-Quran using Braille Display with software help. The system reads the database which contains all verses of Al-Quran and user will need to select the verse and ayah to read. Besides that, this system can be used in a class to teach visually impaired students to learn Al-Quran. Every word or character typed by the instructor in the main Braille Panel will be transmitted to the sub Braille Panel that is connected to the main Braille Panel. The selected verse of Al-Quran and ayah will also generate an index before being transmitted to the Braille Panel. The index will be transmitted to the Braille Display for people to touch and read the display. A user friendly Graphical User Interface (GUI) will be used to fulfill the ergonomics for the visually impaired user's physical capabilities. Several approaches are used to design and implement the interface for the visually impaired like speech or sound output and Braille display. The Braille codes can be displayed using the Braille panel. The design interface and structure of the system for the visually impaired users in learning Al-Quran is presented
Fusion versus Breakup: Observation of Large Fusion Suppression for ^9Be + ^{208}Pb
Complete fusion excitation functions for Be + Pb have been
measured to high precision at near barrier energies. The experimental fusion
barrier distribution extracted from these data allows reliable prediction of
the expected complete fusion cross-sections. However, the measured
cross-sections are only 68% of those predicted. The large cross-sections
observed for incomplete fusion products support the interpretation that this
suppression of fusion is caused by Be breaking up into charged fragments
before reaching the fusion barrier. Implications for the fusion of radioactive
nuclei are discussed.Comment: RevTex, 11 pages, 2 postscript figures, to appear in PR
Theory of Multiphonon Excitation in Heavy-Ion Collisions
We study the effects of channel coupling in the excitation dynamics of giant
resonances in relativistic heavy ions collisions. For this purpose, we use a
semiclassical approximation to the Coupled-Channels problem and separate the
Coulomb and the nuclear parts of the coupling into their main multipole
components. In order to assess the importance of multi-step processes, we
neglect the resonance widths and solve the set of coupled equations exactly.
Finite widths are then considered. In this case, we handle the coupling of the
ground state with the dominant Giant Dipole Resonance exactly and study the
excitation of the remaining resonances within the Coupled-Channels Born
Approximation. A comparison with recent experimental data is made.Comment: 29 pages, 7 Postscript figures available upon reques
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