Fomalhaut b: Independent Analysis of the Hubble Space Telescope Public Archive Data

The nature and even the existence of a putative planet-mass companion ("Fomalhaut b") to Fomalhaut has been debated since 2008. In the present paper we reanalyze the multi-epoch ACS/STIS/WFC3 Hubble Space Telescope (HST) optical/near infrared images on which the discovery and some other claims were based. We confirm that the HST images do reveal an object in orbit around Fomalhaut but the detailed results from our analysis differ in some ways from previous discussions. In particular, we do not confirm flux variability over a two-year interval at 0.6 microns wavelength and we detect Fomalhaut b for the first time at the short wavelength of 0.43 microns. We find that the HST image of Fomalhaut b at $0.8\,\mu$m may be extended beyond the PSF. We cannot determine from our astrometry if Fomalhaut b will cross or not the dust ring. The optical through mid-infrared spectral energy distribution (SED) of Fomalhaut b cannot be explained as due to direct or scattered radiation from a massive planet. We consider two models to explain the SED: (1) a large circumplanetary disk around an unseen planet and (2) the aftermath of a collision during the past 50-150 years of two Kuiper Belt-like objects of radii 50 km.Comment: 24 pages, 9 figures, 5 tables, accepted on April, 3rd, 201

GPI PSF subtraction with TLOCI: the next evolution in exoplanet/disk high-contrast imaging

To directly image exoplanets and faint circumstellar disks, the noisy stellar halo must be suppressed to a high level. To achieve this feat, the angular differential imaging observing technique and the least-squares Locally Optimized Combination of Images (LOCI) algorithm have now become the standard in single band direct imaging observations and data reduction. With the development and commissioning of new high-order high-contrast adaptive optics equipped with integral field units, the image subtraction algorithm needs to be modified to allow the optimal use of polychromatic images, field-rotated images and archival data. A new algorithm, TLOCI (for Template LOCI), is designed to achieve this task by maximizing a companion signal-to-noise ratio instead of simply minimizing the noise as in the original LOCI algorithm. The TLOCI technique uses an input spectrum and template Point Spread Functions (PSFs, generated from unocculted and unsaturated stellar images) to optimize the reference image least-squares coefficients to minimize the planet self-subtraction, thus maximizing its throughput per wavelength, while simultaneously providing a maximum suppression of the speckle noise. The new algorithm has been developed using on-sky GPI data and has achieved impressive contrast. This paper presents the TLOCI algorithm, on-sky performance, and will discuss the challenges in recovering the planet spectrum with high fidelity.Comment: 13 pages, 8 figures, to appear in Proceedings of SPIE 914

Global Production Linkages and Stock Market Comovement

Although real integration conceptually plays an important role for the comovement of international equity markets, documenting this link empirically has proven challenging. We construct a new dataset of theory-guided, relevant measures of bilateral trade in final and intermediate goods and services. With these measures, we provide evidence of a strong link between changes in international trade – in particular global value chains – and equity market comovement.These results suggest that supply chain disruptions and reshoring, for instance due to political tensions, war, and the COVID-19 crisis, might affect the interconnections between stock markets via rippling through the global production network

Reação das elites e participação política: uma evidência da transição democrática

Avalia, por meio de dados da Pesquisa Nacional por Amostra de Domicílios (PNAD) de 1988 e dos resultados das eleições legislativas de 1966 e 1974, a relação entre a força da Aliança Renovadora Nacional (ARENA) e a participação eleitoral de analfabetos após a abertura democrática ocorrida no Brasil durante da década de 80. Constatado que a população analfabeta em estados dominados pela ARENA procurou participar do processo eleitoral, buscamos identificar se isso representou uma reação da elite incumbente que buscou manter seu poder através da manipulação dessa população vulnerável, ou se houve uma reação por parte desses analfabetos no sentindo de remover essas oligarquias do poder. Ao verificarmos que esses eleitores possuíam um baixo nível de interesse político e informação, vemos que a segunda hipótese parece implausível. A evidência empírica aqui apresentada é inédita e traz luz á compreensão do processo de persistência institucional nesse importante período da história brasileira

Resilience of New Zealand indigenous forest fragments to impacts of livestock and pest mammals

A number of factors have combined to diminish ecosystem integrity in New Zealand indigenous lowland forest fragments surrounded by intensively grazed pasture. Livestock grazing, mammalian pests, adventive weeds and altered nutrient input regimes are important drivers compounding the changes in fragment structure and function due to historical deforestation and fragmentation. We used qualitative systems modelling and empirical data from Beilschmiedia tawa dominated lowland forest fragments in the Waikato Region to explore the relevance of two common resilience paradigms – engineering resilience and ecological resilience – for addressing the conservation management of forest fragments into the future. Grazing by livestock and foraging/predation by introduced mammalian pests both have direct detrimental impacts on key structural and functional attributes of forest fragments. Release from these perturbations through fencing and pest control leads to partial or full recovery of some key indicators (i.e. increased indigenous plant regeneration and cover, increased invertebrate populations and litter mass, decreased soil fertility and increased nesting success) relative to levels seen in larger forest systems over a range of timescales. These changes indicate that forest fragments do show resilience consistent with adopting an engineering resilience paradigm for conservation management, in the landscape context studied. The relevance of the ecological resilience paradigm in these ecosystems is obscured by limited data. We characterise forest fragment dynamics in terms of changes in indigenous species occupancy and functional dominance, and present a conceptual model for the management of forest fragment ecosystems

Access to evidence-based treatments for young people with body dysmorphic disorder

INTRODUCTION: Body dysmorphic disorder (BDD) typically emerges during adolescence, affects approximately 2% of the general population and is highly impairing. Despite its prevalence and impact, awareness of BDD remains poor and the condition often goes undiagnosed and untreated.1 Cognitive–behavioural therapy (CBT) and selective serotonin reuptake inhibitors (SSRIs) are effective treatments for BDD and recommended as the first-line interventions.2 However, little is known about the accessibility of these treatments within the UK or among young people specifically. We conducted a case note review to examine the treatment histories of young people referred to a tertiary care outpatient clinic for BDD and obsessive-compulsive disorder (OCD) in the UK. We hypothesised that: (a) contrary to the National Institute for Health and Care Excellence guidelines2, a substantial proportion of those with BDD would not have accessed first-line treatment prior to referral to the specialist clinic; (b) fewer patients with BDD would have accessed first-line treatments compared with patients with OCD, despite similar prevalence and morbidity of the two conditions. METHODS: We reviewed consecutive referrals to the National and Specialist OCD, BDD and Related Disorders Clinic at the Maudsley Hospital, received between January 2015 and May 2022, with a primary diagnosis of BDD (n=83) or OCD (n=413). All data were collected as part of routine assessment, which included systematic recording of whether patients had ever previously received CBT for their primary diagnosis, an SSRI medication or any other psychological treatment. Statistical comparisons of the BDD versus OCD group were made using t-tests for continuous data and χ2 test for categorical data. RESULTS: As shown in table 1, the BDD group reported a significantly later onset, were older at assessment and had a greater female preponderance than the OCD group. The two groups had substantial, but comparable, levels of global functioning, as indicated by scores on the Children’s Global Assessment Scale. The majority of both the BDD and OCD groups had received SSRIs prior to referral. However, fewer than half of the BDD group had received CBT for BDD prior to referral, whereas three-quarters of the OCD group had received CBT for OCD, representing a significant group difference. Conversely, a significantly larger proportion of the BDD group had received other forms of therapy, relative to the OCD group. The most common ‘other therapy’ received by the BDD group was counselling or CBT for another condition (see table 2)

M-band Imaging of the HR 8799 Planetary System Using an Innovative LOCI-based Background Subtraction Technique

Multi-wavelength observations/spectroscopy of exoplanetary atmospheres are the basis of the emerging exciting field of comparative exoplanetology. The HR 8799 planetary system is an ideal laboratory to study our current knowledge gap between massive field brown dwarfs and the cold 5-Gyr old Solar system planets. The HR 8799 planets have so far been imaged at J- to L-band, with only upper limits available at M-band. We present here deep high-contrast Keck II adaptive optics M-band observations that show the imaging detection of 3 of the 4 currently known HR 8799 planets. Such detections were made possible due to the development of an innovative LOCI-based background subtraction scheme that is 3 times more efficient than a classical median background subtraction for Keck II AO data, representing a gain in telescope time of up to a factor of 9. These M-band detections extend the broad band photometric coverage out to about 5 microns and provide access to the strong CO fundamental absorption band at 4.5microns. The new M-band photometry shows that the HR 8799 planets are located near the L/T-type dwarf transition, similar to what was found by other studies. We also confirm that the best atmospheric fits are consistent with low surface gravity, dusty and non-equilibrium CO/CH4 chemistry models.Comment: 10 pages, 4 figures, 1 table, accepted in ApJ

The International Deep Planet Survey II: The frequency of directly imaged giant exoplanets with stellar mass

Radial velocity and transit methods are effective for the study of short orbital period exoplanets but they hardly probe objects at large separations for which direct imaging can be used. We carried out the international deep planet survey of 292 young nearby stars to search for giant exoplanets and determine their frequency. We developed a pipeline for a uniform processing of all the data that we have recorded with NIRC2/Keck II, NIRI/Gemini North, NICI/Gemini South, and NACO/VLT for 14 years. The pipeline first applies cosmetic corrections and then reduces the speckle intensity to enhance the contrast in the images. The main result of the international deep planet survey is the discovery of the HR 8799 exoplanets. We also detected 59 visual multiple systems including 16 new binary stars and 2 new triple stellar systems, as well as 2,279 point-like sources. We used Monte Carlo simulations and the Bayesian theorem to determine that 1.05[+2.80-0.70]% of stars harbor at least one giant planet between 0.5 and 14M_J and between 20 and 300 AU. This result is obtained assuming uniform distributions of planet masses and semi-major axes. If we consider power law distributions as measured for close-in planets instead, the derived frequency is 2.30[+5.95-1.55]%, recalling the strong impact of assumptions on Monte Carlo output distributions. We also find no evidence that the derived frequency depends on the mass of the hosting star, whereas it does for close-in planets. The international deep planet survey provides a database of confirmed background sources that may be useful for other exoplanet direct imaging surveys. It also puts new constraints on the number of stars with at least one giant planet reducing by a factor of two the frequencies derived by almost all previous works.Comment: 83 pages, 13 figures, 15 Tables, accepted in A&

Management of failed spinal anaesthesia for caesarean section

Background. Failed spinal anaesthesia for caesarean section (CS) may be partial or complete and the subsequent discomfort is the most commonly cited cause of litigation in obstetric anaesthesia.Objectives. To determine if there is a standardised approach to: (i) testing the level of block of spinal anaesthesia; and (ii) the management of failed spinal anaesthesia for CS.Methods. A structured questionnaire to ascertain the current practice of testing the level of block and management of three different scenarios of failed spinal anaesthesia was distributed to 51 government hospitals in KwaZulu-Natal, South Africa (SA). All obstetric anaes­thetic service providers, ranging from interns to specialist anaesthetists, were invited to complete the questionnaire.Results. A total of 375 responses were received from 42 of the 51 hospitals surveyed. Specialist anaesthetists managed failure of spinal anaesthesia significantly differently than other anaesthetic service providers. Specialists were more likely to convert to a general anaesthetic (GA), while others were more likely to repeat spinal anaesthesia or administer intravenous ketamine, midazolam and opioids. Only 212 respondents (56%) tested the level of block and there was no difference between the groups with regard to the method of assessment of height (p=0.15). Non-specialists, however, accepted a significantly lower level of block, using pinprick, than specialists (p=0.027), which could lead to a higher failure rate. More than one-third of non-specialists did not consider themselves competent to perform a GA and >90% of respondents agreed that a ‘failed’ spinal algorithm would be useful.Conclusion. There is a need for standardised assessment of the adequacy of spinal anaesthesia for CS in SA, as well as a failed spinal algorithm.

Management of failed spinal anaesthesia for caesarean section

Background. Failed spinal anaesthesia for caesarean section (CS) may be partial or complete and the subsequent discomfort is the most commonly cited cause of litigation in obstetric anaesthesia. Objectives. To determine if there is a standardised approach to: (i) testing the level of block of spinal anaesthesia; and (ii) the management of failed spinal anaesthesia for CS. Methods. A structured questionnaire to ascertain the current practice of testing the level of block and management of three different scenarios of failed spinal anaesthesia was distributed to 51 government hospitals in KwaZulu-Natal, South Africa (SA). All obstetric anaes­thetic service providers, ranging from interns to specialist anaesthetists, were invited to complete the questionnaire. Results. A total of 375 responses were received from 42 of the 51 hospitals surveyed. Specialist anaesthetists managed failure of spinal anaesthesia significantly differently than other anaesthetic service providers. Specialists were more likely to convert to a general anaesthetic (GA), while others were more likely to repeat spinal anaesthesia or administer intravenous ketamine, midazolam and opioids. Only 212 respondents (56%) tested the level of block and there was no difference between the groups with regard to the method of assessment of height (p=0.15). Non-specialists, however, accepted a significantly lower level of block, using pinprick, than specialists (p=0.027), which could lead to a higher failure rate. More than one-third of non-specialists did not consider themselves competent to perform a GA and >90% of respondents agreed that a ‘failed’ spinal algorithm would be useful. Conclusion. There is a need for standardised assessment of the adequacy of spinal anaesthesia for CS in SA, as well as a failed spinal algorithm