Evolution of Fragmentation Cloud in Highly Eccentric Orbit Using Representative Objects

Many historical on-orbit satellite fragmentations occurred in Highly Eccentric Orbits (HEOs) such as the Geostationary Transfer Orbit (GTO). Such fragmentations produce fragment clouds that interfere with the Low Earth Orbit (LEO) environment and pose a threat to operational satellites. Objects in HEO undergo complex dynamics due to the influence of perturbations varying as a function mainly of their altitude and area-to-mass ratio. The evolution of such a cloud, including small objects down to 1 mm, is not well understood. This paper describes a method to model the evolution of a fragmentation cloud in HEO under the influence of atmospheric drag and Earth's oblateness. Semi-analytical techniques are applied to propagate represen- tative objects constituting the cloud; rather than following the evolution of many distinct fragments. The proposed method is applied on a GTO upper stage using the standard NASA break-up model to nd the distribution right after the fragmentation. The evolution of the fragment cloud is analysed statistically and time of closures are calculated for the formation of the torus along the parent orbit and the band around Earth. Assumptions on the evolution of the cloud that are valid in LEO are shown to be invalid for clouds in HEO

Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark

During the fishing process, fish react to a trawl with a series of behaviours that often are species and size specific. Thus, a thorough understanding of fish behaviour in relation to fishing gear and a scientific understanding of the ability of different gear designs to utilize or stimulate various behavioural patterns during the catching process are essential for developing more efficient, selective, and environmentally friendly trawls. Although many behavioural studies using optical and acoustic observation systems have been conducted, harsh observation conditions on the fishing grounds often hamper the ability to directly observe fish behaviour in relation to fishing gear. As an alternative to optical and acoustic methods, we developed and applied a new mathematical model to catch data to extract detailed and quantitative information about species- and size-dependent escape behaviour in towed fishing gear such as trawls. We used catch comparison data collected with a twin trawl setup; the only difference between the two trawls was that a 12 m long upper section was replaced with 800 mm diamond meshes in one of them. We investigated the length-based escape behaviour of cod (Gadus morhua), haddock (Melanogrammus aeglefinus), saithe (Pollachius virens), witch flounder (Glyptocephalus cynoglossus), and lemon sole (Microstomus kitt) and quantified the extent to which behavioural responses set limits for the large mesh panel's selective efficiency. Around 85% of saithe, 80% of haddock, 44% of witch flounder, 55% of lemon sole, and 55% of cod (below 68 cm) contacted the large mesh panel and escaped. We also demonstrated the need to account for potential selectivity in the trawl body, as it can bias the assessment of length-based escape behaviour. Our indirect assessment of fish behaviour was in agreement with the direct observations made for the same species in a similar section of the trawl body reported in the literature

A case report of hereditary apolipoprotein A-I amyloidosis associated with a novel APOA1 mutation and variable phenotype

Apolipoprotein A-I (apo A-I) amyloidosis is a non-AL, non-AA, and non-transthyretin type of amyloidosis associated with mutations in the APOA1 gene inherited in an autosomal dominant fashion. It is a form of systemic amyloidosis, but at presentation, can also mimic localized amyloidosis. The renal presentation generally involves interstitial and medullary deposition of apo A-I amyloid protein. We describe the identification of apo A-I amyloidosis by mass spectrometry in a 52-year old male, with no family history of amyloidosis, presenting with nephrotic syndrome and associated with heterozygosity for a novel APOA1 mutation (c.220 T > A) which encodes the known amyloidogenic Trp50Arg variant. Renal amyloid deposits in this case were confined to the glomeruli alone, and the patient developed progressive renal impairment. One year after diagnosis, the patient had a successful kidney transplant from an unrelated donor. Pathogenic mutations in the APOA1 gene are generally associated with symptoms of amyloidosis. In this family however, genotyping of family members identified several unaffected carriers suggesting a variable disease penetrance, which has not been described before in this form of amyloidosis and has implications when counselling those with APOA1 mutations

Reflectance spectroscopy characterization of space debris

When characterizing the space debris environment one important point is the identification of the physical properties of the space debris objects. Reflectance spectroscopy is a possible technique to study the surface material of these objects with observations from the ground. In this work the results collected from spectroscopy observations of space debris in orbit are presented. The observations were performed at the 1-m ESA Space Debris Telescope (ESASDT) in Tenerife equipped with a spectrograph in the 450–960 nm wavelength range. A preliminary classification using three different categories purely based on the shape and appearance of the spectra was proposed. Two debris objects with high AMR could be successfully associated with materials analyzed in the laboratory. The results show that the two debris objects are probably pieces of Kapton MLI with ‘gold’ and ‘silver’ coating, respectively. Color indices were extracted from the spectroscopic measurements. For high AMR objects the colors seem to be consistent with the proposed classification in three categories. The B-R and R-I laboratory measurements of ‘gold’ and ‘silver’ MLI taken from the literature are comparable with the obtained results

Ultrasound evidence of altered lumbar connective tissue structure in human subjects with chronic low back pain

<p>Abstract</p> <p>Background</p> <p>Although the connective tissues forming the fascial planes of the back have been hypothesized to play a role in the pathogenesis of chronic low back pain (LBP), there have been no previous studies quantitatively evaluating connective tissue structure in this condition. The goal of this study was to perform an ultrasound-based comparison of perimuscular connective tissue structure in the lumbar region in a group of human subjects with chronic or recurrent LBP for more than 12 months, compared with a group of subjects without LBP.</p> <p>Methods</p> <p>In each of 107 human subjects (60 with LBP and 47 without LBP), parasagittal ultrasound images were acquired bilaterally centered on a point 2 cm lateral to the midpoint of the L2-3 interspinous ligament. The outcome measures based on these images were subcutaneous and perimuscular connective tissue thickness and echogenicity measured by ultrasound.</p> <p>Results</p> <p>There were no significant differences in age, sex, body mass index (BMI) or activity levels between LBP and No-LBP groups. Perimuscular thickness and echogenicity were not correlated with age but were positively correlated with BMI. The LBP group had ~25% greater perimuscular thickness and echogenicity compared with the No-LBP group (ANCOVA adjusted for BMI, p < 0.01 and p < 0.001 respectively).</p> <p>Conclusion</p> <p>This is the first report of abnormal connective tissue structure in the lumbar region in a group of subjects with chronic or recurrent LBP. This finding was not attributable to differences in age, sex, BMI or activity level between groups. Possible causes include genetic factors, abnormal movement patterns and chronic inflammation.</p

Near-normalization of glycaemic control with glucagon-like peptide-1 receptor agonist treatment combined with exercise in patients with type 2 diabetes

AIMS: To investigate the effects of exercise in combination with a glucagon‐like peptide‐1 receptor agonist (GLP‐1RA), liraglutide, or placebo for the treatment of type 2 diabetes. METHODS: Thirty‐three overweight, dysregulated and sedentary patients with type 2 diabetes were randomly allocated to 16 weeks of either exercise and liraglutide or exercise and placebo. Both groups had three supervised 60‐minute training sessions per week including spinning and resistance training. RESULTS: Glycated haemoglobin (HbA1c) levels dropped by a mean ± standard deviation of 2.0% ± 1.2% (from 8.2% ± 1.4%) in the exercise plus liraglutide group vs 0.3% ± 0.9% (from 8.0% ± 1.2%) in the exercise plus placebo group ( P < .001), and body weight was reduced more with liraglutide (−3.4 ± 2.9 kg vs −1.6 ± 2.3 kg; P < .001). Compared with baseline, similar reductions were seen in body fat (exercise plus liraglutide: −2.5% ± 1.4% [ P < .001]; exercise plus placebo: −2.2% ± 1.9% [ P < .001]) and similar increases were observed in maximum oxygen uptake (exercise plus liraglutide: 0.5 ± 0.5 L O(2)/min [ P < .001]; exercise plus placebo: 0.4 ± 0.4 L O(2)/min [ P = .002]). Greater reductions in fasting plasma glucose (−3.4 ± 2.3 mM vs −0.3 ± 2.6 mM, P < .001) and systolic blood pressure (−5.4 ± 7.4 mm Hg vs −0.6 ± 11.1 mm Hg, P < .01) were seen with exercise plus liraglutide vs exercise plus placebo. The two groups experienced similar increases in quality of life during the intervention. CONCLUSIONS: In obese patients with type 2 diabetes, exercise combined with GLP‐1RA treatment near‐normalized HbA1c levels and caused a robust weight loss when compared with placebo. These results suggest that a combination of exercise and GLP‐1RA treatment is effective in type 2 diabetes

A multimodality localization technique for radio-guided surgery

<p>Abstract</p> <p>Background</p> <p>Intraoperative localization of image or endoscopy-detected lesions occasionally pose surgical challenges due to the small lesion size and/or difficult anatomic exposure. Identification of such lesions can be facilitated using a hand-held gamma probe with utilization of Tc-99m macroaggregate albumen (MAA) localization technique. The radiopharmaceutical injection can be performed using ultrasound (US) or endoscopy guidance.</p> <p>Case presentations</p> <p>The clinical use of the Tc-99m MAA protocol gamma probe-guided surgery was discussed in three representative cases. Surgical indication was diagnostic exploration in two patients with suspicious lymphadenopathy, and determination of extent of surgical resection in a patient with polyposis. Lesion localization with 100 microcurie (3.7 MBq) Tc-99m MAA prior to surgical exploration resulted in definitive localization of lesions intraoperatively.</p> <p>Conclusion</p> <p>The use Tc-99m MAA deposition technique at the site of surgical target is a highly efficient radio-guided surgery technique with definitive impact on the success of surgical exploration in selected indications.</p

Drag and Solar Sail Deorbiting: Re-Entry Time Versus Cumulative Collision Probability

Solar and drag sailing have been proposed as passive end-of-life deorbiting methods, and technological demonstrators are under development. For orbit above 800 km altitude solar radiation pressure can be exploited for increasing the orbit eccentricity until the perigee enters the drag region until final re-entry. The performance of the sailing strategy is determined by four parameters: the required effective area-to-mass ratio to deorbit the spacecraft, which determine the sail size given the satellite’s mass, the time to deorbit and the augmented collision probability caused on and by the sail through its passage in the Low Earth Orbit protected region densely populated by space debris. In this paper we assess the sail dimension with respect to the augmented collision risk depending on the sail area and the deorbiting time

The EASL–<em>Lancet</em> Commission on liver health in Europe: prevention, case-finding, and early diagnosis to reduce liver-related mortality

In December, 2021, the first report from the Lancet Commission on liver disease in Europe, a joint project with the European Association for the Study of the Liver (EASL), was published. 1 The Commission explored the harm to liver health in Europe that results from a combination of increasing obesity, the highest level of alcohol consumption in the world, and delays in viral hepatitis elimination. The Commission emphasised the importance of structural factors that drive risk behaviours and poor outcomes in liver disease, with disproportionate effects on disadvantaged and vulnerable populations. Such structural drivers include the heterogeneous landscape of alcohol policy in Europe, fragmented access to testing and therapy for viral hepatitis, and stigmatisation faced by individuals at risk of liver disease at the societal level and within health-care settings. 2 , 3 This stigma contributes to care avoidance and delayed diagnosis, ultimately leading to a bias in clinical pathways that prioritise managing advanced liver disease rather than early diagnosis and primary and secondary prevention of liver disease. The Commission report included ten recommendations to facilitate a shift towards health promotion, prevention, proactive case-finding, early identification of progressive liver fibrosis, and early management and treatment of liver diseases (figure). 1 The key message of the Commission was paraphrased by Ursula von der Leyen, the President of the European Commission, in her remarks made at the launch event: “in most cases, liver disease can be prevented. Prevention is the best cure that we have.