scholarly journals The Effect of Post-Newtonian Spin Precessions on the Evolution of Exomoons’ Obliquity

2022 ◽  
Vol 163 (2) ◽  
pp. 55
Author(s):  
Lorenzo Iorio
Keyword(s):  
Main Sequence ◽  
Habitable Zone ◽  
Spin Orbit ◽  
De Sitter ◽  
Quadrupole Mass ◽  
Angular Momenta ◽  
Mass Moment ◽  
General Relativistic ◽  
The Common

Abstract Putative natural massive satellites (exomoons) have gained increasing attention when they orbit Jupiter-like planets within the habitable zone of their host main-sequence star S. An exomoon s is expected to move within the equatorial plane of its host planet p, with its spin S s aligned with its orbital angular momentum L , which, in turn, is parallel to the planetary spin S p. If, in particular, the common tilt ε of such angular momenta to the plane of the satellite–planet motion about the star, assumed fixed, has certain values, the stellar latitudinal irradiation experienced on the exomoon may allow it to sustain life as we know it, at least for certain orbital configurations. An Earth analog (similar in mass, radius, oblateness, and obliquity) is considered, which orbits within 5–10 planetary radii R p from its Jupiter-like host planet. The de Sitter and Lense–Thirring spin precessions due to the general relativistic post-Newtonian (pN) field of the host planet have an impact on an exomoon’s habitability for a variety of different initial spin–orbit configurations. Here I show it by identifying long-term variations in the satellite’s obliquity ε s, where variations can be ≲10°–100°, depending on the initial spin–orbit configuration, with a timescale of ≃0.1–1 million years. Also the satellite’s quadrupole mass moment J 2 s induces obliquity variations that are faster than the pN ones but do not cancel them. Tidal dissipations, which may potentially have a relevant impact on the outlined pattern, are not included in the present analysis.

scholarly journals A comment on ‘Lense–Thirring frame dragging induced by a fast-rotating white dwarf in a binary pulsar system’ by V. Venkatraman Krishnan et al.

2020 ◽  
Vol 495 (3) ◽  
pp. 2777-2785 ◽  
Author(s):  
Lorenzo Iorio
Keyword(s):  
Parameter Space ◽  
White Dwarf ◽  
Orbital Plane ◽  
Rate Of Change ◽  
Quadrupole Mass ◽  
Frame Dragging ◽  
Mass Moment ◽  
General Relativistic ◽  
Analytical Expressions ◽  
Fast Rotating

ABSTRACT We comment on a recent study reporting evidence for the general relativistic Lense–Thirring secular precession of the inclination I of the orbital plane to the plane of the sky of the tight binary system PSR J1141-6545 made of a white dwarf and an emitting radiopulsar of comparable masses. The quadrupole mass moment $Q_2^\mathrm{c}$ and the angular momentum ${\boldsymbol{S}}^\mathrm{c}$ of the white dwarf cause the detectable effects on I with respect to the present-day accuracy in the pulsar’s timing. The history-dependent and model-dependent assumptions to be made on $Q_2^\mathrm{c}$ and ${\boldsymbol{S}}^\mathrm{c}$, required even just to calculate the analytical expressions for the resulting post-Keplerian precessions, may be deemed as too wide in order to claim a successful test of the Einsteinian gravitomagnetic effect. Moreover, depending on how $Q_2^\mathrm{c}$ is calculated, the competing quadrupole-induced rate of change, which is a major source of systematic uncertainty, may be up to ${\lesssim}30{-}50{{\ \rm per\ cent}}$ of the Lense–Thirring effect for most of the allowed values in the 3D parameter space spanned by the white dwarf’s spin period Ps, and the polar angles $i_\mathrm{c},\, \zeta _\mathrm{c}$ of its spin axis. The possible use of the longitude of periastron ϖ is investigated as well. It turns out that a measurement of its secular precession, caused, among other things, also by $Q_2^\mathrm{c},\, {\boldsymbol{S}}^\mathrm{c}$, could help in further restricting the permitted regions in the white dwarf’s parameter space.

scholarly journals A Post-Newtonian Gravitomagnetic Effect on the Orbital Motion of a Test Particle around Its Primary Induced by the Spin of a Distant Third Body

Universe ◽  
2019 ◽  
Vol 5 (4) ◽  
pp. 87
Author(s):  
Lorenzo Iorio
Keyword(s):  
Angular Momentum ◽  
Test Particle ◽  
Equations Of Motion ◽  
Body System ◽  
Long Term Effects ◽  
Body Effect ◽  
Angular Momenta ◽  
General Relativistic ◽  
Range Rate

We study a general relativistic gravitomagnetic 3-body effect induced by the spin angular momentum S X of a rotating mass M X orbited at distance r X by a local gravitationally bound restricted two-body system S of size r ≪ r X consisting of a test particle revolving around a massive body M. At the lowest post-Newtonian order, we analytically work out the doubly averaged rates of change of the Keplerian orbital elements of the test particle by finding non-vanishing long-term effects for the inclination I, the node Ω and the pericenter ω . Such theoretical results are confirmed by a numerical integration of the equations of motion for a fictitious 3-body system. We numerically calculate the magnitudes of the post-Newtonian gravitomagnetic 3-body precessions for some astronomical scenarios in our solar system. For putative man-made orbiters of the natural moons Enceladus and Europa in the external fields of Saturn and Jupiter, the relativistic precessions due to the angular momenta of the gaseous giant planets can be as large as ≃10 − 50 milliarcseconds per year (mas year−1). A preliminary numerical simulation shows that, for certain orbital configurations of a hypothetical Europa orbiter, its range-rate signal Δ ρ ˙ can become larger than the current Doppler accuracy of the existing spacecraft Juno at Jupiter, i.e., σ ρ ˙ = 0.015 mm s−1, after 1 d. The effects induced by the Sun’s angular momentum on artificial probes of Mercury and the Earth are at the level of ≃ 1 − 0.1 microarcseconds per year (μas year −1).

The foundations of peaceful coexistence after the war ... Mosul is a model

2019 ◽  
pp. 178
Author(s):  
Omar Hashim Thanon
Keyword(s):  
Ethnic Diversity ◽  
Psychological Consequences ◽  
Peaceful Coexistence ◽  
Negative Effects ◽  
Mass Displacement ◽  
The Common ◽  
Near Term ◽  
Post War ◽  
Common Destiny

Since peaceful coexistence reflects in its various aspects the concept of harmony between the members of the same society with their different national, religious and sectarian affiliations, as well as their attitudes and ideas, what brings together these are the common bonds such as land, interests and common destiny. But this coexistence is exposing for crises and instability and the theft of rights and other that destroy the communities with their different religious, national, sectarian, ethnic aspects, especially if these led to a crisis of fighting or war, which produces only destruction and mass displacement, ttherefore, the process of bridging the gap between the different parts of society in the post-war phase through a set of requirements that serve as the basis for the promotion of peaceful coexistence within the same country to consolidate civil and community peace in order to create a general framework and a coherent basis to reconstruct the community again.      Hence the premise of the research by asking about the extent of the possibility and ability of the community of religious and ethnic diversity, which has been exposed to these crises, which aimed at this diversity, basically to be able to rise and re-integrate within the same country and thus achieve civil and community peace, and Mosul is an example for that, the negative effects of the war and the accomplices of many criminal acts have given rise to hatred and fear for all, leading to the loss of livelihoods, which in the long term may have devastating social and psychological consequences.        To clarify all of this, the title of the first topic was a review of the concept and origin of peaceful coexistence. While the second topic dealt with the requirements of peaceful coexistence and social integration in Mosul, the last topic has identified the most important challenges facing the processes of coexistence and integration in Mosul. All this in order to paint a better future for the conductor at all levels in the near term at the very least to achieve the values of this peaceful coexistence, especially in the post-war period.

Hemorrhoidal Laser procedure (HeLP) and Hemorrrrhoidal Laser procedure + mucopexy (HeLPexx) and other Emerging Technologies

2020 ◽  
Vol 15 ◽  
Author(s):  
Paolo Giamundo
Keyword(s):  
Laser Treatment ◽  
Dentate Line ◽  
Mucosal Prolapse ◽  
Daily Activities ◽  
Common Goal ◽  
Superior Rectal Artery ◽  
Doppler Probe ◽  
The Common ◽  
Probe Set

Background: Minimally-invasive treatments for hemorrhoids should be encouraged as they cause low morbidity, reasonable discomfort and quicker return to work. According to the “vascular theory” hemorrhoidal disease is mainly caused by blood overflow into hemorrhoidal plexus deriving from the superior hemorrhoidal arteries. Introduction: Many different procedures have been described in the literature with the common goal of reducing the blood flow into the hemorrhoidal piles. ‘HeLP’ (Hemorrhoids Laser Procedure) is a novel form of dearterialization to treat patients suffering from symptomatic hemorrhoids. Methods: The procedure consists of the closure of the terminal branches of the superior rectal artery approximately 2-3 cm above the dentate line by means of laser shots originated by a diode laser platform. The arteries, at that level, have variable location and distribution. Therefore, a doppler probe set at the frequency of 20MHz helps identifying the arteries that would be missed otherwise. The laser beam is well tolerated by patients. For this reason, anesthesia is not required in most cases and the procedure allows a quick return to daily activities. In case of concomitant severe mucosal prolapse, the laser treatment can be combined with suture mucopexy. Three to six running sutures allow a complete lifting of hemorrhoidal piles, securing long-term resolution of symptoms. Results and Conclusions: ‘HeLP’ is indicated in patients with symptomatic hemorrhoids where conservative treatment failed and when mucosal prolapse is scarce or not symptomatic. The addition of mucopexy to laser treatment (HeLPexx) contributes to overall resolution of symptoms when mucosal prolapse is an issue, Emborrhoid is another novel, ‘hi-tech’ form of selective dearterialization used in selected case of hemorrhoids where main symptom is bleeding. It is generally used in cases where surgery is contraindicated due to severe concomitant diseases.

The Co-Occurrence of Autism and Gender Diversity

2020 ◽  
pp. 197-211
Author(s):  
Jill C. Fodstad ◽  
Rebecca Elias ◽  
Shivali Sarawgi
Keyword(s):  
Gender Dysphoria ◽  
Gender Diversity ◽  
Gender Nonconforming ◽  
Medical Interventions ◽  
Gender Diverse ◽  
Nonbinary Gender ◽  
Psychiatric Conditions ◽  
The Common ◽  
And Gender

Gender diversity refers to gender expressions and/or gender identity experiences that vary from the common experiences of gender. Gender-diverse people may be gender nonconforming, gender nonbinary, gender fluid, gender exploring, transgender, and so forth. Some gender-diverse individuals experience gender dysphoria and/or gender incongruence and may require gender-affirming supports, including gender-affirming medical interventions. The co-occurrence of autism and gender diversity has been highlighted in a series of studies internationally as well as through rich community expressions. Studies in gender-referred individuals reveal high rates of autism traits as well as high rates of existing autism diagnoses. Studies in autistic populations reveal greater gender diversity characteristics. The long-term course of gender diversity in autistic individuals is poorly understood. Clinical guidelines have been developed for adolescents with the co-occurrence, but much work remains: No gender-related measures have been developed and tested for use in neurodiverse populations, no programs exist to support gender-diverse neurodiverse adults, and little is known about co-occurring mental health profiles, risks, or protective factors for people with the co-occurrence. The inclusion of this chapter on co-occurring autism and gender diversity within a book on “co-occurring psychiatric conditions” is problematic, because gender diversity is not a “psychiatric condition,” but instead a form of human diversity. The diagnosis of Gender Dysphoria is useful only insomuch as it allows individuals to obtain necessary gender-related supports. The authors’ choice to include this chapter in this book reflects a compromise, motivated by the need for educating both autism and gender specialists in this common co-occurrence.

scholarly journals Contributions to Management Strategies in the NE Atlantic Regarding the Life History and Population Structure of a Key Deep-Sea Fish (Mora moro)

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 522
Author(s):  
Régis Santos ◽  
Wendell Medeiros-Leal ◽  
Osman Crespo ◽  
Ana Novoa-Pabon ◽  
Mário Pinho
Keyword(s):  
Population Structure ◽  
Life History ◽  
Deep Sea ◽  
Management Strategies ◽  
Size Composition ◽  
Large Size ◽  
The Common ◽  
Fishing Impacts ◽  
Sea Fish

With the commercial fishery expansion to deeper waters, some vulnerable deep-sea species have been increasingly captured. To reduce the fishing impacts on these species, exploitation and management must be based on detailed and precise information about their biology. The common mora Mora moro has become the main deep-sea species caught by longliners in the Northeast Atlantic at depths between 600 and 1200 m. In the Azores, landings have more than doubled from the early 2000s to recent years. Despite its growing importance, its life history and population structure are poorly understood, and the current stock status has not been assessed. To better determine its distribution, biology, and long-term changes in abundance and size composition, this study analyzed a fishery-dependent and survey time series from the Azores. M. moro was found on mud and rock bottoms at depths below 300 m. A larger–deeper trend was observed, and females were larger and more abundant than males. The reproductive season took place from August to February. Abundance indices and mean sizes in the catch were marked by changes in fishing fleet operational behavior. M. moro is considered vulnerable to overfishing because it exhibits a long life span, a large size, slow growth, and a low natural mortality.

Ultrasonic Percutaneous Tenotomy for Recalcitrant Lateral Elbow Tendinopathy: Clinical and Sonographic Results at 90 Months

2021 ◽  
pp. 036354652110101
Author(s):  
Benjamin F.H. Ang ◽  
P. Chandra Mohan ◽  
Meng Ai Png ◽  
John Carson Allen ◽  
Tet Sen Howe ◽  
...  
Keyword(s):  
Pain Relief ◽  
Extensor Tendon ◽  
Tissue Healing ◽  
Lateral Elbow ◽  
Percutaneous Tenotomy ◽  
Vas Scores ◽  
The Common ◽  
Lateral Elbow Tendinopathy

Background: In a study from our institution, ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon for recalcitrant lateral elbow tendinopathy showed excellent safety profiles, high tolerability, efficiency, sustained pain relief, functional improvement, and sonographic evidence of tissue healing in 20 patients at 3 years’ follow-up. Purpose: To explore the long-term clinical and sonographic results of ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon. Study Design: Case series; Level of evidence, 4. Methods: The same cohort of 20 patients was recalled after 7 years, and visual analog scale (VAS) for pain and Disabilities of the Arm, Shoulder and Hand (DASH) scores, need for secondary intervention, and overall satisfaction were assessed. They were also reassessed using ultrasound imaging of the brevis and the common extensor tendon to evaluate tendon hypervascularity, tendon thickness, and the progress or the recurrence of the hypoechoic scar tissue. Results: We successfully scored 19 patients and performed ultrasound on 16 patients with a median follow-up of 90 months (range, 86-102 months). There were no adverse outcomes and satisfaction remained at 100% (6 patients, satisfied; 13 patients, very satisfied). No patient developed a recurrence of symptoms and signs of lateral elbow tendinopathy, and therefore no secondary intervention was required. The improvement from baseline and early term scores was sustained ( P < .001 for all). At 90 months, there was a significant improvement in VAS scores and DASH–Compulsory scores compared with preprocedure scores and all follow-up times until 3 months. There was no difference in VAS scores and DASH–Compulsory scores at 90 months compared with 6 and 36 months. For DASH–Work scores, there was a significant improvement at 90 months compared with preprocedure scores, but there was no difference between DASH–Work scores at 90 months and scores at all other points of follow-up. At 90 months, hypervascularity remained resolved in 79% of patients, while all patients had reduced tendon swelling and sustained resolution or reduction of the hypoechoic lesion. Conclusion: At the long-term follow-up of 90 months, ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon, previously shown to enhance recovery of lateral elbow tendinopathy, demonstrated good durability of pain relief and functional recovery that was previously achieved. This was accompanied by sustained sonographic tissue healing with no significant deterioration.

scholarly journals Acute symptoms of mild to moderate COVID-19 are highly heterogeneous across individuals and over time

2021 ◽  
Author(s):  
Thomas L Rodebaugh ◽  
Madelyn R Frumkin ◽  
Angela M Reiersen ◽  
Eric J Lenze ◽  
Michael S Avidan ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Survey Methods ◽  
Clinical Care ◽  
Clinical Deterioration ◽  
Symptom Profiles ◽  
Fluctuating Course ◽  
The Common ◽  
Symptom Changes ◽  
Over Time

Abstract Background The symptoms of COVID-19 appear to be heterogenous, and the typical course of these symptoms is unknown. Our objectives were to characterize the common trajectories of COVID-19 symptoms and assess how symptom course predicts other symptom changes as well as clinical deterioration. Methods 162 participants with acute COVID-19 responded to surveys up to 31 times for up to 17 days. Several statistical methods were used to characterize the temporal dynamics of these symptoms. Because nine participants showed clinical deterioration, we explored whether these participants showed any differences in symptom profiles. Results Trajectories varied greatly between individuals, with many having persistently severe symptoms or developing new symptoms several days after being diagnosed. A typical trajectory was for a symptom to improve at a decremental rate, with most symptoms still persisting to some degree at the end of the reporting period. The pattern of symptoms over time suggested a fluctuating course for many patients. Participants who showed clinical deterioration were more likely to present with higher reports of severity of cough and diarrhea. Conclusion The course of symptoms during the initial weeks of COVID-19 is highly heterogeneous and is neither predictable nor easily characterized using typical survey methods. This has implications for clinical care and early-treatment clinical trials. Additional research is needed to determine whether the decelerating improvement pattern seen in our data is related to the phenomenon of patients reporting long-term symptoms, and whether higher symptoms of diarrhea in early illness presages deterioration.

scholarly journals Hamiltonian charges in the asymptotically de Sitter spacetimes

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Maciej Kolanowski ◽  
Jerzy Lewandowski
Keyword(s):  
Phase Space ◽  
Initial Data ◽  
Exact Solutions ◽  
Gravitational Waves ◽  
Physical Meaning ◽  
De Sitter ◽  
Killing Vectors ◽  
Asymptotically Flat ◽  
Angular Momenta ◽  
The One

Abstract We generalize a notion of ‘conserved’ charges given by Wald and Zoupas to the asymptotically de Sitter spacetimes. Surprisingly, our construction is less ambiguous than the one encountered in the asymptotically flat context. An expansion around exact solutions possessing Killing vectors provides their physical meaning. In particular, we discuss a question of how to define energy and angular momenta of gravitational waves propagating on Kottler and Carter backgrounds. We show that obtained expressions have a correct limit as Λ → 0. We also comment on the relation between this approach and the one based on the canonical phase space of initial data at ℐ+.

Preparation and Long-Term Stability Study of Steel Fiber/Graphite Conductive Concrete

2016 ◽  
Vol 680 ◽  
pp. 361-364 ◽  
Author(s):  
Jun Du ◽  
Cheng Tang ◽  
Bo Jia ◽  
De Zhang ◽  
Qiang Miao
Keyword(s):  
Corrosion Resistance ◽  
Steel Fiber ◽  
Stability Study ◽  
Soil Resistivity ◽  
Grounding Resistance ◽  
Term Stability ◽  
Long Term Stability ◽  
Conductive Fillers ◽  
The Common

The steel fiber/graphite conductive concrete is applied in power system grounding. In high soil resistivity regions, the common methods for reducing the grounding resistance are not practical. It is difficult for grounding resistance of substations to meet the requirements of working earthing and safety earthing. In order to solve this problem, a steel fiber/graphite conductive concrete is developed in this paper. Steel fiber and graphite are added as conductive fillers. The long-term stability of the steel fiber/graphite conductive concrete is studied. The experiment results show that steel fiber/graphite conductive concrete not only maintains excellent conductivity, but also has good mechanical strength and corrosion resistance in 300 days.

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