An investigation of the needs and the design of an orbiting space station with growth capabilities

An architectural approach to the evolutionary growth of an orbiting space station from a small manned satellite to a fully independent, self-sustainable space colony facility is presented. Social and environmental factors, ease of transportation via the space shuttle, and structural design are considered

Matrices associated to two conservative discretizations of Riesz fractional operators and related multigrid solvers

In this article, we focus on a two-dimensional conservative steady-state Riesz fractional diffusion problem. As is typical for problems in conservative form, we adopt a finite volume (FV)-based discretization approach. Precisely, we use both classical FVs and the so-called finite volume elements (FVEs). While FVEs have already been applied in the context of fractional diffusion equations, classical FVs have only been applied in first-order discretizations. By exploiting the Toeplitz-like structure of the resulting coefficient matrices, we perform a qualitative study of their spectrum and conditioning through their symbol, leading to the design of a second-order FV discretization. This same information is leveraged to discuss parameter-free symbol-based multigrid methods for both discretizations. Tests on the approximation error and the performances of the considered solvers are given as well

The politics of impunity: a study of journalists’ experiential accounts of impunity in Bulgaria, Democratic Republic of Congo, India, Mexico and Pakistan

Definitions of impunity regarding crimes against journalists have thus far been too narrow. Therefore we propose a new approach to understanding impunity as also being grounded in journalists’ lived reality and perceptions to better understand the complexity and breadth of impunity. It is based on the findings obtained through a set of semi-structured interviews with 40 editors and senior journalists in five countries and expressed in a new typology of impunity. We argue that what we call the ‘Politics of Impunity’ is a policy of governance whereby impunity is used as a political tool by the state and state-sponsored actors to achieve journalistic self-censorship. This is done through the deliberate deprivation of private autonomy brought about by the enforced exile of journalists into a ‘space of exception’ where they are both within and beyond the law. The exercise of the ‘Politics of Impunity’ in an increasing number of states creates an environment that only allows for politically compliant journalism

Differential Response of C9orf72 Transcripts Following Neuronal Depolarization

The (G4C2)n nucleotide repeat expansion (NRE) mutation in C9orf72 is the most common genetic cause of ALS and FTD. The biological functions of C9orf72 are becoming understood, but it is unclear if this gene is regulated in a neural-specific manner. Neuronal activity is a crucial modifier of biological processes in health and neurodegenerative disease contexts. Here, we show that prolonged membrane depolarization in healthy human iPSC-cortical neurons leads to a significant downregulation of a transcript variant 3 (V3) of C9orf72, with a concomitant increase in variant 2 (V2), which leads to total C9orf72 RNA transcript levels remaining unchanged. However, the same response is not observed in cortical neurons derived from patients with the C9-NRE mutation. These findings reveal the impact of depolarization on C9orf72 transcripts, and how this response diverges in C9-NRE-carriers, which may have important implications in the underlying unique clinical associations of C9-NRE transcripts and disease pathogenesis

Breakdown of the Central Synapses in C9orf72-Linked ALS/FTD

Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disease that leads to the death of motor and cortical neurons. The clinical manifestations of ALS are heterogenous, and efficacious treatments to significantly slow the progression of the disease are lacking. Cortical hyper-excitability is observed pre-symptomatically across disease-causative genetic variants, as well as in the early stages of sporadic ALS, and typically precedes motor neuron involvement and overt neurodegeneration. The causes of cortical hyper-excitability are not yet fully understood but is mainly agreed to be an early event. The identification of the nucleotide repeat expansion (GGGGCC)n in the C9ORF72 gene has provided evidence that ALS and another neurodegenerative disease, frontotemporal dementia (FTD), are part of a disease spectrum with common genetic origins. ALS and FTD are diseases in which synaptic dysfunction is reported throughout disease onset and stages of progression. It has become apparent that ALS/FTD-causative genes, such as C9ORF72, may have roles in maintaining the normal physiology of the synapse, as mutations in these genes often manifest in synaptic dysfunction. Here we review the dysfunctions of the central nervous system synapses associated with the nucleotide repeat expansion in C9ORF72 observed in patients, organismal, and cellular models of ALS and FTD

Definition of Healthy Ranges for Alanine Aminotransferase Levels: A 2021 Update

The changing epidemiology of liver disease, and modifications in the recommended analytical methodology call for a re-evaluation of the upper reference limits (URLs) of alanine aminotransferase (ALT) levels. Using the same ap- proach consolidated 20 years ago to define the healthy population, we defined the URL for the newly recommended International Federation of Clinical Chemistry (IFCC) standardized test. In a cross-sectional study, we examined 21,296 apparently healthy blood donors (age 18-65 years) and calculated the sex-specific URL by the 95th percentile in indi- viduals without risk factors for liver disease. These were tested for the ability to predict liver damage in a subset of 745 participants with dysmetabolism, in an independent cohort of 977 unselected donors, and in 899 patients with chronic liver disease. ALT levels were measured by the IFCC test. Male sex, body mass index, glucose, lipids, ferritin, hyper- tension, and younger age were independent ALT predictors (P < 0.001). Updated URLs were identified at 42/30 U/L in males/females, approximately 30% lower than those currently recommended by the IFCC. Due to improved sensitiv- ity, they conferred the ability to detect steatosis and significant fibrosis in individuals with dysmetabolism (odds ratio [OR] = 2.31, range 1.40-3.80, P = 0.001; and OR = 3.35, range 1.19-9.42, P = 0.021; respectively), although with a limited accuracy, and significant fibrosis in unselected donors (OR = 2.32, 1.02-5.31, P = 0.045). Updated URLs had a moderate to high accuracy to discriminate liver conditions (area under the receiver operating characteristic curve = 0.81, range 0.78-0.91). Conclusion: Updated URLs by the IFCC method were lower than those calculated in initial studies, but higher than those in use with the recommended old, nonstandardized method, and were able to better predict liver disease. The limited awareness that different techniques are still in use should be regarded as a possible source of medical errors

Analysis of the relationship between offense and race of youth within the juvenile justice system

It has been routine to analyze the racial balance of the youth processed through the various components of the juvenile justice system in relation to their proportion in the general population appropriate age groups. It has been fairly well established through these studies, updated over several years, that a consistent general trend with reference to race does exist in South Carolina for youth processed through the system. With the intent to examine this issue, therefore, the following study was completed utilizing the populations committed in 1977 to both the R & E Center and the training schools in analyzing the relationship of commitment to both the factors of race and offense. A further comparison is then presented in reference to the other Juvenile Justice System components

Wake Up and Talk with Me! In-the-Field Study of an Autonomous Interactive Wake Up Robot

12th International Conference, ICSR 2020, Golden, CO, USA, November 14–18, 2020In this paper, we present a robot that is designed to smoothly wake up a user in the morning. We created an autonomous interactive wake up robot that implements a wake up behavior that was selected through preliminary experiments. We conducted a user study to test the interactive robot and compared it to a baseline robot that behaves like a conventional alarm clock. We recruited 22 participants that agreed to bring the robot to their home and test it for two consecutive nights. The participants felt significantly less sleepy after waking up with the interactive robot, and reported significantly more intention to use the interactive robot

Facing erythrocytosis: Results of an international physician survey.

We observed a good agreement among hematologists regarding the diagnostic procedures and a widespread awareness regarding the importance of the new 2016 WHO criteria and bone marrow his-tology. On the other side, we observed a marked heterogeneity in treatment practice, regarding both the Hct threshold and the use of anti-platelet agents