The Apollo Group Asteroid 2008 OS9: Discovery, Orbit, Rotation and the Yarkovsky/YORP Effects

2010 ◽  
Vol 19 (3-4) ◽  
Author(s):  
K. Černis ◽  
I. Eglitis ◽  
I. Wlodarczyk ◽  
J. Zdanavičius ◽  
K. Zdanavičius
Keyword(s):  
Rotation Period ◽  
Major Axis ◽  
Brightness Variation ◽  
Semi Major Axis ◽  
Mean Values ◽  
Secular Changes ◽  
Photometric Observations ◽  
The Mean ◽  
The Difference

AbstractA project for astrometric and photometric observations of asteroids at the Baldone Observatory is described. One of the most important results of the project is the discovery of 2008 OS9, a 600 meter asteroid of the NEO Apollo group. The results of its astrometric and photometric observations at the Molėtai and Baldone observatories are presented. From the brightness variation with the 0.27 mag amplitude, a rotation period of 8.430 ± 0.005 h is determined. Close approaches of the asteroid to Earth and Venus during the next millenium are predicted. The mean values of secular changes in the semi-major axis, eccentricity and inclination are computed with and without the Yarkovsky and YORP effects. A negative value of the difference between the value of semi-major axis computed with the Yarkovsky and YORP effects and without them, da/dt, may indicate retrograde rotation of the asteroid.

Photometric results of the long-term monitoring of the active asteroid (596) Scheila

2020 ◽  
Author(s):  
Zhong-Yi Lin ◽  
Chen-Yen Hsu
Keyword(s):  
Light Curve ◽  
Rotation Period ◽  
Impact Event ◽  
Mean Values ◽  
Photometric Observations ◽  
The Mean ◽  
The Difference ◽  
The Impact ◽  
Term Monitoring

<p>(596) Scheila was observed to have an active appearance as a result of impact event in late 2010. In additional the coma feature, the shape of light curve had been found the difference probably fresh material or surface properties changed around the impact site. In this study, we present the results of our monitoring observations obtained in 2014 and 2019-2020. The mean values of the color indices (B−V = (0.75 ± 0.08)<sup>m</sup>, V−R = (0.45 ± 0.04)<sup>m</sup>, and R−I = (0.44 ± 0.09)<sup>m</sup>) agree well with the values for asteroids of the D-types. The rotation period of the asteroid estimated from photometric observations in 2014 is 15.8 ± 0.1 h. The shape of the light curve is similar as that found after impact event. Furthermore, we did not find any rotational color variability in B-V, V-R and R-I diagrams, meaning the observed surface in this observing period of 2019-2020 is homogeneous.</p>

scholarly journals Utility of Nuclear Morphometry in Predicting Grades of Diffusely Infiltrating Gliomas

ISRN Oncology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Dibyajyoti Boruah ◽  
Prabal Deb
Keyword(s):  
Major Axis ◽  
Strong Positive Correlation ◽  
Nuclear Area ◽  
Tumour Grade ◽  
Neoplastic Tissue ◽  
Mean Values ◽  
Positive Correlation ◽  
The Mean ◽  
The Difference ◽  
Immense Potential

Introduction. The ability to reliably differentiate neoplastic from nonneoplastic specimen and ascertain the tumour grade of diffusely infiltrating gliomas (DIGs) is often challenging. Aims and Objective. To evaluate utility of image morphometry in identifying DIG areas and to predict tumour grade. Materials and Methods. Image morphometry was used to analyze the following nuclear features of 30 DIGs and 10 controls (CG): major axis of nucleus (MAJX), minor axis of nucleus (MINX), nuclear area (NA), nuclear perimeter (NP), nuclear roundness (NR), nuclear density (ND), and percentage of total nuclear area (%TNA). Results. Statistically significant differences in all parameters, except NR, were observed between all groups, with strong positive correlation with tumour grade (r>0.7). The mean values were maximum for HGG and minimum for CG. For NR, the difference between CG/HGG was statistically significant, unlike CG/LGG and LGG/HGG. It was observed that NA distributions for CG were nearly Gaussian type with smaller range, while gliomas displayed erratic pattern with larger range. NA and NP exhibited strong positive correlation with ND. Conclusion. Image morphometry has immense potential in being a powerful tool to distinguish normal from neoplastic tissue and also to differentiate LGG from HGG cases, especially in tiny stereotactic biopsies.

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

scholarly journals Some Special Types of Orbits around Jupiter

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 183
Author(s):  
Yongjie Liu ◽  
Yu Jiang ◽  
Hengnian Li ◽  
Hui Zhang
Keyword(s):  
Gravity Model ◽  
Small Perturbation ◽  
Equilibrium Points ◽  
Major Axis ◽  
Semi Major Axis ◽  
Ground Track ◽  
The Earth ◽  
Degenerate Equilibrium ◽  
The Mean ◽  
Element Theory

This paper intends to show some special types of orbits around Jupiter based on the mean element theory, including stationary orbits, sun-synchronous orbits, orbits at the critical inclination, and repeating ground track orbits. A gravity model concerning only the perturbations of J2 and J4 terms is used here. Compared with special orbits around the Earth, the orbit dynamics differ greatly: (1) There do not exist longitude drifts on stationary orbits due to non-spherical gravity since only J2 and J4 terms are taken into account in the gravity model. All points on stationary orbits are degenerate equilibrium points. Moreover, the satellite will oscillate in the radial and North-South directions after a sufficiently small perturbation of stationary orbits. (2) The inclinations of sun-synchronous orbits are always bigger than 90 degrees, but smaller than those for satellites around the Earth. (3) The critical inclinations are no-longer independent of the semi-major axis and eccentricity of the orbits. The results show that if the eccentricity is small, the critical inclinations will decrease as the altitudes of orbits increase; if the eccentricity is larger, the critical inclinations will increase as the altitudes of orbits increase. (4) The inclinations of repeating ground track orbits are monotonically increasing rapidly with respect to the altitudes of orbits.

scholarly journals Creation/destruction of ultra-wide binaries in tidal streams

2020 ◽  
Author(s):  
Jorge Peñarrubia
Keyword(s):  
Globular Clusters ◽  
Galactic Halo ◽  
Local Density ◽  
Formation Rate ◽  
Semimajor Axis ◽  
Major Axis ◽  
Binding Energies ◽  
Semi Major Axis ◽  
The Mean ◽  
Tidal Streams

Abstract This paper uses statistical and N-body methods to explore a new mechanism to form binary stars with extremely large separations (≳ 0.1 pc), whose origin is poorly understood. Here, ultra-wide binaries arise via chance entrapment of unrelated stars in tidal streams of disrupting clusters. It is shown that (i) the formation of ultra-wide binaries is not limited to the lifetime of a cluster, but continues after the progenitor is fully disrupted, (ii) the formation rate is proportional to the local phase-space density of the tidal tails, (iii) the semimajor axis distribution scales as p(a)da ∼ a1/2da at a ≪ D, where D is the mean interstellar distance, and (vi) the eccentricity distribution is close to thermal, p(e)de = 2ede. Owing to their low binding energies, ultra-wide binaries can be disrupted by both the smooth tidal field and passing substructures. The time-scale on which tidal fluctuations dominate over the mean field is inversely proportional to the local density of compact substructures. Monte-Carlo experiments show that binaries subject to tidal evaporation follow p(a)da ∼ a−1da at a ≳ apeak, known as Öpik’s law, with a peak semi-major axis that contracts with time as apeak ∼ t−3/4. In contrast, a smooth Galactic potential introduces a sharp truncation at the tidal radius, p(a) ∼ 0 at a ≳ rt. The scaling relations of young clusters suggest that most ultra-wide binaries arise from the disruption of low-mass systems. Streams of globular clusters may be the birthplace of hundreds of ultra-wide binaries, making them ideal laboratories to probe clumpiness in the Galactic halo.

DIE AUSSCHEIDUNG VON TESTOSTERON UND EPITESTOSTERON BEI FRAUEN AM ENDE DER SCHWANGERSCHAFT

1969 ◽  
Vol 60 (4) ◽  
pp. 579-585
Author(s):  
K. Schollberg ◽  
E. Seiler ◽  
J. Holtorff
Keyword(s):  
Urinary Excretion ◽  
Late Pregnancy ◽  
Mean Values ◽  
Pregnant Females ◽  
Female Foetus ◽  
The Mean ◽  
The Difference ◽  
Normal Women ◽  
In Pregnancy

ABSTRACT The urinary excretion of testosterone and epitestosterone by women in late pregnancy has been studied. The mean values of 22 normal women in pregnancy mens X are 12.9 ± 9.2 μg/24 h in the case of testosterone and 16.1 ± 16.2 μg/24 h in the case of epitestosterone. Both values do not differ significantly from those of non-pregnant females. The excretion values of mothers bearing a male foetus (17.3 ± 8.9 μg/24 h) are higher than those of mothers with a female foetus (6.4 ± 4.8 μg/24 h). The difference is statistically significant with P = 0.01.

scholarly journals Influence of Apical Patency and Cleaning of the Apical Foramen on Periapical Extrusion in Retreatment

2013 ◽  
Vol 24 (5) ◽  
pp. 482-486 ◽  
Author(s):  
Marili Doro Andrade Deonizio ◽  
Gilson Blitzkow Sydney ◽  
Antonio Batista ◽  
Roberto Pontarolo ◽  
Paulo Ricardo Bittencourt Guimarães ◽  
...  
Keyword(s):  
Material Removal ◽  
Filling Material ◽  
Mean Values ◽  
Filtration System ◽  
Root Canal Retreatment ◽  
Significant Difference ◽  
Before And After ◽  
The Mean ◽  
The Difference ◽  
Removal Technique

This study evaluated the influence of apical patency, root filling removal technique and cleaning of the apical foramen, concerning the amount of debris extruded during root canal retreatment. Forty mandibular incisors were randomly assigned to 4 groups - GIM (n=10), GIIM (n=10), GIPT (n=10) and GIIPT (n=10), which were named according to leaving (I) or not (II) apical patency during canal preparation and filling removal technique (manual - M or ProTaper system - PT). After filling material removal, each specimen of each group had the apical foramen cleaned by sizes 15, 20 and 25 instruments, generating 12 subgroups: GIM15, GIM20, GIM25, GIIM15, GIIM20, GIIM25, GIPT15, GIPT20, GIPT25, GIIPT15, GIIPT20 and GIIPT25. Extruded filling debris was collected by a Milipore filtration system, an HV-durapore, 0.45 µm pore filter with a 25 mm diameter. The filters were weighed before and after the collection on an analytical scale (10–5 g), and the difference was calculated. The mean weight of extruded filling debris was analyzed statistically by Kruskal-Wallis and Friedman ANOVA tests (α=0.05). The mean values found in the groups (in mg) were: GIM (0.95±0.94), GIIM (0.47±0.62), GIPT (0.30±0.31) and GIIPT (0.32±0.44). There was no statistically significant difference among any of the groups or subgroups (p>0.05). ProTaper provided the smallest amount of extruded filling material, regardless of presence or absence of apical patency, followed by manual technique, without and with apical patency. Additional amounts of debris were collected during cleaning of the apical foramen, regardless of the instrument, presence/absence of patency or root filling removal technique.

Effect of smoking on cardiovascular autonomic functions

2021 ◽  
Vol 9 (2) ◽  
pp. 3780-3784
Author(s):  
P.Vani ◽  
◽  
Sharan B Singh M ◽  
Keyword(s):  
Heart Rate ◽  
Autonomic Function ◽  
T Test ◽  
Resting Heart Rate ◽  
Autonomic Functions ◽  
Mean Values ◽  
Function Tests ◽  
Significant Difference ◽  
The Mean ◽  
The Difference

Introduction: Cigarette smoking is a prime risk factor for cardiovascular morbidity and mortality. Chronic smoking results in autonomic dysfunction leading to increased cardiovascular risk in smokers. The present study was planned to study the effect of smoking on the Cardiovascular Autonomic Functions among smokers. Materials and Methods: Fifty male subjects who were in the age group of 25 to 45 years. They were grouped into 25 smokers and 25 non-smokers. The participant subjects were selected among the staff members, residents and the patients from the routine OPD in SVIMS. Prior to study, they were informed about the procedure and the purpose of the study tests and written consents were obtained from them. The Cardiovascular Autonomic Function Tests were assessed by using a POLYGRAPH which was available in the department. Results and Conclusion: After applying the ‘t’-test for the difference between the two sample means, it was observed that there was a highly significant difference between the mean values of the BMI(i.e.p<0.01) and the para-sympathetic function tests among the smokers and the non – smokers(i.e.p<0.00). The Resting Heart Rate had significantly increased and the Deep breathing difference, the postural tachycardial index (Response to standing) and the Valsalva Ratio had significantly decreased in the smokers as compared to those in the non – smokers. After applying the ‘t’-test for the difference between the two sample means, it was observed that there was no significant difference between the mean values of the Postural hypotension test (i.e. p>0.05) and that there was a highly significant difference between the mean values of the Sustained handgrip test in the smokers and the non – smokers (i.e. p<0.00). KEY WORDS: Cardiovascular autonomic function tests, Smoking, Resting heart rate.

scholarly journals Lateral Antebrachial Cutaneous Nerve as a Donor Source for Digital Nerve Grafting: A Concept Revisited

2017 ◽  
Vol 11 (1) ◽  
pp. 1041-1048 ◽  
Author(s):  
Mehmet Bekir Unal ◽  
Kemal Gokkus ◽  
Evrim Sirin ◽  
Eren Cansü
Keyword(s):  
Pearson Correlation ◽  
Mean Value ◽  
Cutaneous Nerve ◽  
Digital Nerve ◽  
Mean Values ◽  
Nerve Grafts ◽  
The Mean ◽  
The Difference ◽  
Mean Time

Objective: The main objective of this study is to evaluate the availability of lateral antebrachial cutaneous nerve (LACN) autograft for acute or delayed repair of segmented digital nerve injuries. Patients and Methods: 13 digital nerve defects of 11 patients; treated with interposition of LACN graft that harvested from ipsilateral extremity were included in the study. Mean follow up period was 35, 7 months. The mean time from injury to grafting is 53, 3 days. The results of the mean 2PDT and SWMT values of injured /uninjured finger at the end of follow up period were evaluated with Paired T test. The correlation between the defect length and the difference of 2PDT, SWMT values between the uninjured and injured finger at the end of follow up period; were evaluated with Pearson - correlation analysis. Results: The mean value of our 2PDT and SWMT results are ~5,923, ~3, 52, respectively in which can be interpreted between the normal and diminished light touch. The defect length and difference percentage of SWMT values is positively and significantly correlated statistically. Mean length of interposed nerve grafts was 18.5 mm. The age of the patient and the mean values of 2PDT and SWMT with the difference % of 2PDT and % of SWMT are not statistically correlated. Conclusion: Based on results regarding sensory regaining at recipient side and negligible sensory deficit at harvesting side, we suggest that lateral antebrachial cutaneous nerve might be a valuable graft option for digital nerve defects.

scholarly journals Retinomotor movements in the Antarctic fish Trematomus newnesi Boulenger submitted to different environmental light conditions

2007 ◽  
Vol 24 (2) ◽  
pp. 457-462 ◽  
Author(s):  
Lucélia Donatti ◽  
Edith Fanta
Keyword(s):  
Pigment Epithelium ◽  
Antarctic Fish ◽  
Constant Darkness ◽  
Time Intervals ◽  
Mean Values ◽  
Environmental Light ◽  
The Mean ◽  
The Difference ◽  
The One ◽  
The Antarctic

The Antarctic fish Trematomus newnesi (Boulenger, 1902) occurs from benthic to pelagic habitats, in seasonally and daily varied photic conditions that induce retinomotor movements. Fish were experimentally kept under constant darkness or light, and 12Light/12Dark for seven days. The retinomotor movement of the pigment epithelium was established through the pigment index, while that of the cones was calculated as the length of the myoid. The retinomotor movement of the pigment epithelium in T.newnesi,revealed that the adaptation to constant light occurred in the one hour of exposure, remaining constant for the next seven days. However, the adaptation to constant darkness, was slower. The difference between the mean values of the pigment indices in the time intervals of sampling was significant in the first hours of the experiment, and only after six hours they were not significant any more. The myoid of cones became elongated in darkness and contracted in light. In the experiments where T.newnesiwas exposed initially to 12 hours light followed by 12 hours darkness 12 was evidenced that the speed and intensity of the retinomotor movements was higher when darkness changed into light, than when light changed into darkness.

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