How frequent are close supermassive binary black holes in powerful jet sources?

24 pages, 36 figures. © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)Supermassive black hole binariesmay be detectable by an upcoming suite of gravitationalwave experiments. Their binary nature can also be revealed by radio jets via a short-period precession driven by the orbital motion as well as the geodetic precession at typically longer periods. We have investigated Karl G. Jansky Very Large Array and Multi-Element Radio Linked Interferometer Network (MERLIN) radio maps of powerful jet sources for morphological evidence of geodetic precession. For perhaps the best-studied source, Cygnus A, we find strong evidence for geodetic precession. Projection effects can enhance precession features, for which we find indications in strongly projected sources. For a complete sample of 33 3CR radio sources, we find strong evidence for jet precession in 24 cases (73 per cent). The morphology of the radio maps suggests that the precession periods are of the order of 10 6- 10 7 yr. We consider different explanations for the morphological features and conclude that geodetic precession is the best explanation. The frequently observed gradual jet angle changes in samples of powerful blazars can be explained by orbital motion. Both observations can be explained simultaneously by postulating that a high fraction of powerful radio sources have subparsec supermassive black hole binaries.We consider complementary evidence and discuss if any jetted supermassive black hole with some indication of precession could be detected as individual gravitational wave source in the near future. This appears unlikely, with the possible exception of M87.Peer reviewedFinal Published versio

Redressing COVID-19 vaccine inequity amidst booster doses: charting a bold path for global health solidarity, together

BACKGROUND: With large swathes of the world's population-majority clustered in low- and middle-income countries-still yet to receive the minimum of two doses of the COVID-19 vaccine; The need to address the failures of international solidarity to equitably distribute COVID-19 vaccines is now more urgent than ever to help curb the pandemic and prevent future variants. However, many high-income countries have adopted a "me first" approach, proceeding to offer COVID-19 booster doses to their entire populations, including those at least risk of severe illness, whilst the rest of the world is left unvaccinated or partially vaccinated with one dose for even their most vulnerable communities. MAIN BODY: COVID-19 vaccine inequity places the health of the global population at risk and exacerbates socio-economic repercussions, especially in low- and middle-income countries. Initiatives launched to combat vaccine inequity such as the Fair Allocation Framework for the COVID-19 Vaccines (COVAX) have been unsuccessful as several governments, primarily from high-income countries, have scaled down their contributions to the initiative. Furthermore, COVAX has not seriously engaged with the Access to COVID-19 Tools (ACT) Health Systems Connector, as was originally intended, leading to crucial health systems components critical to vaccine delivery to be overlooked. Several strategies can be employed to help achieve the desired global immunization goals, such as Intellectual Property waivers, increased donations, and activation of new COVID-19 vaccine manufacturing hubs. In addition, continued advocacy for vaccine equity by all involved and affected stakeholders, as well as critical amendments to existing or upcoming legislation and funding mechanisms will help address the shortcomings of current inequitable vaccine distribution. CONCLUSIONS: Global solidarity and collective action through pandemic governance mechanisms are urgently needed to ensure vaccine equity. These interventions are vital to rapidly mitigate ongoing health and humanitarian crises and ultimately curb the pandemic, sooner rather than later

Awareness regarding causes of infertility among out-patients at a tertiary care hospital in Karachi, Pakistan

Introduction: Infertility is the inability of a couple to achieve pregnancy within 12 months of sexual intercourse without the use of contraceptives. The Pakistani population, belonging to a low-middle income country, has a high prevalence of infertility due to a low knowledge and awareness regarding its causes, and lack of healthcare-seeking behavior for this medical issue. The prevalence of infertility in Pakistan is reported as 22%, with primary infertility accounting for 4% of the total cases. This leads to psychological trauma among women as societal norms equate infertility with failure on a personal, emotional, and social level. In this study, we aimed to assess among this population the general awareness regarding infertility and its causes; and identify any key knowledge gaps pertaining to the subject.Methods: A cross-sectional study was carried out between June 2019 and November 2019, at a public hospital (Civil Hospital Karachi) in Karachi, Pakistan. Convenience sampling technique was used to collect data from adult participants (older than 18 years) via an interview-administered questionnaire. The questionnaire was based on the Cardiff Fertility Knowledge Scale (CFKS) and assessed the knowledge regarding causes of infertility such as smoking, healthy lifestyle, contraceptives, genital tract infections among others. We also determined the association between socio-demographic variables with mean knowledge scores. Data were analyzed using Statistical Package for Social Sciences (SPSS), version 20.0.Results: The majority of the participants were married (n=342, 68.8%) and more than half were unemployed (n=259, 52.1%). Approximately, two-quarters (n=250, 50.3%) did not believe that equal proportions of males and females contribute to infertility. The mean knowledge score of our study population was 12.95 ± 2.48 points. An overwhelming proportion of the participants (n=326, 65.6%) falsely believed that the usage of the intra-uterine device contributes to infertility. Additionally, more than half of the responders (n=278, 55.9%) incorrectly believed that a male achieving erection is an indication of fertility. Education (p=0.019), vehicle ownership (p=0.018), and marital status (p=0.031) were the only demographic factors that showed significant differences with mean knowledge scores.Conclusion: Awareness regarding the causes of infertility among the general population was found to be inadequate. Emphasis on targeted fertility education, in association with general public awareness programs regarding its causes and risk factors may help mitigate this problem by potentially reducing the prevalence of this condition, and increasing the number of affected individuals who seek medical care in a timely fashion

Mental health implications on Afghan children: an impending catastrophe

Afghan children have suffered for decades because of chronic socioeconomic health crises. The current state of Afghanistan has deprived the basic human needs of children. The lack of freedom leaves their voices unheard, causing detrimental effects on their mental health. Mental illnesses such as post-traumatic stress disorder, anxiety, and depression are prevalent in Afghanistan, causing severe negative outcomes among children. Promotion of mental health services, psychological training, awareness campaigns, acceptance of Afghan refugees, and initiatives to support re-connecting with loved ones, are among the many recommended measures needed to manage this alarming situation. This requires an immediate action plan from government and public health officials to mitigate this impending catastrophe

Afghanistan's humanitarian crisis and its impacts on the mental health of healthcare workers during COVID-19

Afghanistan's humanitarian crisis has severely impacted the mental health of frontline workers. With the introduction of the Taliban government, ongoing civil unrest, and other forms of violent attacks, healthcare workers (HCWs) continue to provide patient care despite minimal resources. A severe contraction in the economy, poor supply of medications, political turmoil, and insufficient humanitarian aid have added to pre-existing problems. High levels of insecurity and instability as well as decades of traumatic experiences have contributed to increasing mental health challenges amongst frontline workers. Despite the scarcity of mental health services, HCWs continue to persevere with their service to the community. However, inadequate interventions may have serious implications for HCWs bearing the brunt of multiple traumas. Thus, governmental and international involvement is needed to address both the economic and psychological needs of HCWs in Afghanistan

How frequent are close supermassive binary black holes in powerful jet sources?

Supermassive black hole binaries may be detectable by an upcoming suite of gravitational wave experiments. Their binary nature can also be revealed by radio jets via a short-period precession driven by the orbital motion as well as the geodetic precession at typically longer periods. We have investigated Karl G. Jansky Very Large Array and Multi-Element Radio Linked Interferometer Network (MERLIN) radio maps of powerful jet sources for morphological evidence of geodetic precession. For perhaps the best-studied source, Cygnus A, we find strong evidence for geodetic precession. Projection effects can enhance precession features, for which we find indications in strongly projected sources. For a complete sample of 33 3CR radio sources, we find strong evidence for jet precession in 24 cases (73 per cent). The morphology of the radio maps suggests that the precession periods are of the order of 106-107 yr. We consider different explanations for the morphological features and conclude that geodetic precession is the best explanation. The frequently observed gradual jet angle changes in samples of powerful blazars can be explained by orbital motion. Both observations can be explained simultaneously by postulating that a high fraction of powerful radio sources have subparsec supermassive black hole binaries. We consider complementary evidence and discuss if any jetted supermassive black hole with some indication of precession could be detected as individual gravitational wave source in the near future. This appears unlikely, with the possible exception of M87.MJH acknowledges support from the UK Science and Technology Facilities Council [ST/M001008/1]. HB and GC acknowledge support from the DFG Transregio Programme TR33 and the Munich Excellence Cluster ‘Structure and Evolution of the Universe’. The contribution of GVB, MAN, and AYW to this research was supported by the Australian Research Council Discovery Project, The Key Role of Black Holes in Galaxy Evolution, DP140103341. MAN acknowledges support from a grant of the Brazilian Agency FAPESP (2015/25126-2). The work of AYW has been supported in part by ERC Project No. 267117 (DARK) hosted by Universite´ Pierre et Marie Curie (UPMC) – Paris 6, PI J. Silk. This work benefited from support by the International Space Science Institute, Bern, Switzerland, through its International Team programme ref. no. 393 The Evolution of Rich Stellar Populations & BH Binaries (2017–18

Clinical practice guidelines on the management of variceal bleeding

Gastroesophageal variceal bleeding occurs in 30 - 50% of patients of liver cirrhosis with portal hypertension, with 20-70% mortality in one year. Therefore, it is essential to screen these patients for varices and prevent first episode of bleeding by treating them with β-blockers or endoscopic variceal band ligation. Ideally, the patients with variceal bleeding should be treated in a unit where the personnel are familiar with the management of such patients and where routine therapeutic interventions can be undertaken. Proper management of such patients include: initial assessment, resuscitation, blood volume replacement, vasoactive agents, prevention of associated complications such as bacterial infections, hepatic encephalopathy, coagulopathy and thrombocytopenia, and specific therapy. Rebleeding occurs in about 60% patients within 2 years of their recovery from first variceal bleeding episode, with 33% mortality. Therefore, it is mandatory that all such patients must be started on combination of β-blockers and band ligation to prevent recurrence of bleeding. Patients who required shunt surgery/TIPSS to control the acute episode do not require further preventive measures. These clinical practice guidelines (CPGs) have been jointly developed by Pakistan Society of Hepatology (PSH) and Pakistan Society of Study of Liver Diseases (PSSLD)

Corrosion and heat treatment study of electroless nip-ti nanocomposite coatings deposited on hsla steel

Corrosion and heat treatment studies are essential to predict the performance and sustainability of the coatings in harsh environments, such as the oil and gas industries. In this study, nickel phosphorus (NiP)–titanium (Ti) nanocomposite coatings (NiP-Ti nanoparticles (TNPs)), containing various concentrations of Ti nanoparticles (TNPs) were deposited on high strength low alloy (HSLA) steel through electroless deposition processing. The concentrations of 0.25, 0.50 and 1.0 g/L TNPs were dispersed in the electroless bath, to obtain NiP-TNPs nanocomposite coatings comprising different Ti contents. Further, the effect of TNPs on the structural, mechanical, corrosion, and heat treatment performance of NiP coatings was thoroughly studied to illustrate the role of TNPs into the NiP matrix. Field emission scanning electron microscope (FESEM) and energy dispersive spectroscopy (EDX) results confirm the successful incorporation of TNPs into the NiP matrix. A substantial improvement in the mechanical response of the NiP matrix was noticed with an increasing amount of TNPs, which reached to its ultimate values (hardness 675 Hv, modulus of elasticity 18.26 GPa, and stffness 9.02 kN/m) at NiP-0.5TNPs coatings composition. Likewise, the electrochemical impedance spectroscopy measurements confirmed a tremendous increase in the corrosion inhibition efficiency of the NiP coatings with an increasing amount of TNPs, reaching ~96.4% at a composition of NiP-0.5TNPs. In addition, the NiP-TNPs nanocomposite coatings also unveiled better performance after heat treatment than NiP coatings, due to the presence of TNPs into the NiP matrix and the formation of more stable (heat resistant) phases, such as Ni3P, Ni3Ti, NiO, etc., during the subsequent processing.This publication was made possible by Qatar University Research Grant-IRCC-2020-006. The findings achieved herein are solely the responsibility of the authors

Imbalance of flight-freeze responses and their cellular correlates in the Nlgn3-/y rat model of autism

Abstract Background Mutations in the postsynaptic transmembrane protein neuroligin-3 are highly correlative with autism spectrum disorders (ASDs) and intellectual disabilities (IDs). Fear learning is well studied in models of these disorders, however differences in fear response behaviours are often overlooked. We aim to examine fear behaviour and its cellular underpinnings in a rat model of ASD/ID lacking Nlgn3. Methods This study uses a range of behavioural tests to understand differences in fear response behaviour in Nlgn3 −/y rats. Following this, we examined the physiological underpinnings of this in neurons of the periaqueductal grey (PAG), a midbrain area involved in flight-or-freeze responses. We used whole-cell patch-clamp recordings from ex vivo PAG slices, in addition to in vivo local-field potential recordings and electrical stimulation of the PAG in wildtype and Nlgn3 −/y rats. We analysed behavioural data with two- and three-way ANOVAS and electrophysiological data with generalised linear mixed modelling (GLMM). Results We observed that, unlike the wildtype, Nlgn3 −/y rats are more likely to response with flight rather than freezing in threatening situations. Electrophysiological findings were in agreement with these behavioural outcomes. We found in ex vivo slices from Nlgn3 −/y rats that neurons in dorsal PAG (dPAG) showed intrinsic hyperexcitability compared to wildtype. Similarly, stimulating dPAG in vivo revealed that lower magnitudes sufficed to evoke flight behaviour in Nlgn3 −/y than wildtype rats, indicating the functional impact of the increased cellular excitability. Limitations Our findings do not examine what specific cell type in the PAG is likely responsible for these phenotypes. Furthermore, we have focussed on phenotypes in young adult animals, whilst the human condition associated with NLGN3 mutations appears during the first few years of life. Conclusions We describe altered fear responses in Nlgn3 −/y rats and provide evidence that this is the result of a circuit bias that predisposes flight over freeze responses. Additionally, we demonstrate the first link between PAG dysfunction and ASD/ID. This study provides new insight into potential pathophysiologies leading to anxiety disorders and changes to fear responses in individuals with ASD