Hyper Velocity Stars and the Restricted Parabolic 3-body Problem

Motivated by detections of hypervelocity stars that may originate from the Galactic Center, we revist the problem of a binary disruption by a passage near a much more massive point mass. The six order of magnitude mass ratio between the Galactic Center black hole and the binary stars allows us to formulate the problem in the restricted parabolic three-body approximation. In this framework, results can be simply rescaled in terms of binary masses, its initial separation and binary-to-black hole mass ratio. Consequently, an advantage over the full three-body calculation is that a much smaller set of simulations is needed to explore the relevant parameter space. Contrary to previous claims, we show that, upon binary disruption, the lighter star does not remain preferentially bound to the black hole. In fact, it is ejected exactly in 50% of the cases. Nonetheless, lighter objects have higher ejection velocities, since the energy distribution is independent of mass. Focusing on the planar case, we provide the probability distributions for disruption of circular binaries and for the ejection energy. We show that even binaries that penetrate deeply into the tidal sphere of the black hole are not doomed to disruption, but survive in 20% of the cases. Nor do these deep encounters produce the highest ejection energies, which are instead obtained for binaries arriving to 0.1-0.5 of the tidal radius in a prograde orbit. Interestingly, such deep-reaching binaries separate widely after penetrating the tidal radius, but always approach each other again on their way out from the black hole.[shortened]Comment: 10 pages, 10 Figures, Apj submitte

Novel insights into pericarp, protein body globoids of aleurone layer, starchy granules of three cereals gained using atomic force microscopy and environmental scanning electronic microscopy

In this study, we applied Environmental Scanning Electron Microscopy-Energy Dispersive Spectroscopy (ESEM-EDS) and Atomic Force Microscopy (AFM) analysis of three different cereal caryopses: barley, oat and einkorn wheat. The morphological structures, chemical elemental composition and surface characteristics of the three cereals were described. Regarding the morphology, barley showed the thickest pericarp, providing a strong barrier to digestion and absorption of nutrients. The aleurone layer of each cereal type contained protein body globoids within its cells. Large type-A and small type-B starchy granules were revealed in the endosperm of barley and einkorn wheat, whereas irregular starchy granules were found in oats. The starchy granule elemental composition, detected by ESEM-EDS, was rather homogenous in the three cereals, whereas the pericarp and protein body globoids showed heterogeneity. In the protein body globoids, oats showed higher P and K concentrations than barley and einkorn wheat. Regarding the topographic profiles, detected by AFM, einkorn wheat starchy granules showed a surface profile that differed significantly from that of oats and barley, which were quite similar to one another. The present work provides insights into the morphological and chemical makeup of the three grains shedding light on the higher bio-accessibility of einkorn wheat nutrients compared to barley and oats, providing important suggestions for human nutrition and technological standpoints

Psychosocial and behavioral impact of COVID-19 in autism spectrum disorder: an online parent survey

The 2019 coronavirus disease (COVID-19) outbreak could result in higher levels of psychological distress, especially among people suffering from pre-existing mental health conditions. Young individuals with autism spectrum disorders (ASD) are particularly at risk due to their vulnerability to unpredictable and complex changes. This study aimed to investigate the impact of the COVID-19 pandemic on ASD individuals, whether any pre-pandemic sociodemographic or clinical characteristics would predict a negative outcome, and to narratively characterize their needs. Parents and guardians of ASD individuals filled out an online survey consisting of 40 questions investigating socio-demographic and clinical characteristics of their children, impact of the COVID-19 outbreak on their wellbeing and needs to deal with the emergency. Data were available on 527 survey participants. The COVID-19 emergency resulted in a challenging period for 93.9% of families, increased difficulties in managing daily activities, especially free time (78.1%) and structured activities (75.7%), and, respectively, 35.5% and 41.5% of children presenting with more intense and more frequent behavior problems. Behavior problems predating the COVID-19 outbreak predicted a higher risk of more intense (odds ratio (OR) = 2.16, 95% confidence interval (CI) 1.42-3.29) and more frequent (OR = 1.67, 95% CI 1.13-2.48) disruptive behavior. Even though ASD children were receiving different types of support, also requiring specialist (19.1%) or emergency (1.5%) interventions in a relatively low proportion of cases, a number of needs emerged, including receiving more healthcare support (47.4%), especially in-home support (29.9%), as well as interventions to tackle a potentially disruptive quarantine (16.8%). The COVID-19 outbreak has undoubtedly resulted in increased difficulties among ASD individuals

USP14 inhibition corrects an in vivo model of impaired mitophagy

Mitochondrial autophagy or mitophagy is a key process that allows selective sequestration and degradation of dysfunctional mitochondria to prevent excessive reactive oxygen species, and activation of cell death. Recent studies revealed that ubiquitin-proteasome complex activity and mitochondrial membrane rupture are key steps preceding mitophagy, in combination with the ubiquitination of specific outer mitochondrial membrane (OMM) proteins. The deubiquitinating enzyme ubiquitin-specific peptidase 14 (USP14) has been shown to modulate both proteasome activity and autophagy. Here, we report that genetic and pharmacological inhibition of USP14 promotes mitophagy, which occurs in the absence of the well-characterised mediators of mitophagy, PINK1 and Parkin. Critical to USP14-induced mitophagy is the exposure of the LC3 receptor Prohibitin 2 by mitochondrial fragmentation and mitochondrial membrane rupture. Genetic or pharmacological inhibition of USP14 in vivo corrected mitochondrial dysfunction and locomotion behaviour of PINK1/Parkin mutant Drosophila model of Parkinson's disease, an age-related progressive neurodegenerative disorder that is correlated with diminished mitochondrial quality control. Our study identifies a novel therapeutic target that ameliorates mitochondrial dysfunction and in vivo PD-related symptoms

Neurotransmitter and receptor systems in the subthalamic nucleus

The Subthalamic Nucleus (STh) is a lens-shaped subcortical structure located ventrally to the thalamus, that despite being embryologically derived from the diencephalon, is functionally implicated in the basal ganglia circuits. Because of this strict structural and functional relationship with the circuits of the basal ganglia, the STh is a current target for deep brain stimulation, a neurosurgical procedure employed to alleviate symptoms in movement disorders, such as Parkinson's disease and dystonia. However, despite the great relevance of this structure for both basal ganglia physiology and pathology, the neurochemical and molecular anatomy of the STh remains largely unknown. Few studies have specifically addressed the detection of neurotransmitter systems and their receptors within the structure, and even fewer have investigated their topographical distribution. Here, we have reviewed the scientific literature on neurotransmitters relevant in the STh function of rodents, non-human primates and humans including glutamate, GABA, dopamine, serotonin, noradrenaline with particular focus on their subcellular, cellular and topographical distribution. Inter-species differences were highlighted to provide a framework for further research priorities, particularly in humans

Mapuches del NoBA, transferencia y fortalecimiento de la producción regional

 La gradual erosión cultural provocada por la globalización, pone de manifiesto la pérdida de tradiciones ancestrales.&nbsp

Clinical expression of facioscapulohumeral muscular dystrophy in carriers of 1-3 D4Z4 reduced alleles: Experience of the FSHD Italian National Registry

OBJECTIVES: Facioscapulohumeral muscular dystrophy type 1 (FSHD1) has been genetically linked to reduced numbers ( 64 8) of D4Z4 repeats at 4q35. Particularly severe FSHD cases, characterised by an infantile onset and presence of additional extra-muscular features, have been associated with the shortest D4Z4 reduced alleles with 1-3 repeats (1-3 DRA). We searched for signs of perinatal onset and evaluated disease outcome through the systematic collection of clinical and anamnestic records of de novo and familial index cases and their relatives, carrying 1-3 DRA. SETTING: Italy. PARTICIPANTS: 66 index cases and 33 relatives carrying 1-3 DRA. OUTCOMES: The clinical examination was performed using the standardised FSHD evaluation form with validated inter-rater reliability. To investigate the earliest signs of disease, we designed the Infantile Anamnestic Questionnaire (IAQ). Comparison of age at onset was performed using the non-parametric Wilcoxon rank-sum or Kruskal-Wallis test. Comparison of the FSHD score was performed using a general linear model and Wald test. Kaplan-Meier survival analysis was used to estimate the age-specific cumulative motor impairment risk. RESULTS: No patients had perinatal onset. Among index cases, 36 (54.5%) showed the first signs by 10 years of age. The large majority of patients with early disease onset (26 out of 36, 72.2%) were de novo; whereas the majority of patients with disease onset after 10 years of age were familial (16, 53.3%). Comparison of the disease severity outcome between index cases with age at onset before and over 10 years of age, failed to detect statistical significance (Wald test p value=0.064). Of 61 index cases, only 17 (27.9%) presented extra-muscular conditions. Relatives carrying 1-3 DRA showed a large clinical variability ranging from healthy subjects, to patients with severe motor impairment. CONCLUSIONS: The size of the D4Z4 allele is not always predictive of severe clinical outcome. The high degree of clinical variability suggests that additional factors contribute to the phenotype complexity

Tidal disruption of inclined or eccentric binaries by massive black holes

Binary stars that are on close orbits around massive black holes (MBHs) such as Sgr A∗ in the centre of the Milky Way are liable to undergo tidal disruption and eject a hypervelocity star. We study the interaction between such an MBH and circular binaries for general binary orientations and penetration depths (i.e. binaries penetrate into the tidal radius around the BH). We show that for very deep penetrators, almost all binaries are disrupted when the binary rotation axis is roughly oriented towards the BH or it is in the opposite direction. The surviving chance becomes significant when the angle between the binary rotation axis and the BH direction is between 0.15π and 0.85π. The surviving chance is as high as ∼20 per cent when the binary rotation axis is perpendicular to the BH direction. However, for shallow penetrators, the highest disruption chance is found in such a perpendicular case, especially in the prograde case. This is because the dynamics of shallow penetrators is more sensitive to the relative orientation of the binary and orbital angular momenta. We provide numerical fits to the disruption probability and energy gain at the BH encounter as a function of the penetration depth. The latter can be simply rescaled in terms of binary masses, their initial separation, and the binary-to-BH mass ratio to evaluate the ejection velocity of a binary members in various systems. We also investigate the disruption of coplanar, eccentric binaries by an MBH. It is shown that for highly eccentric binaries retrograde orbits have a significantly increased disruption probability and ejection velocities compared to the circular binaries