Thermal Risk Mitigation Testing of the DarkNESS Observatory for Fermi NationalAccelerator Laboratory

This paper presents the prototype design and laboratory test results of the thermal control system for the Dark matter as sterile Neutrino Search Satellite (DarkNESS). A collaboration between Fermilab, CU Aerospace, and the University of Illinois Department of Aerospace Engineering’s Laboratory for Advanced Space Systems (LASSI), the 6U satellite uses a Skipper CCD to detect weak 3.55 – 3.57 keV X-ray emissions, previously discovered by the XMM-Newton and Chandra X-ray observatories. To minimize read-out noise, the thermal control system incorporates a 10 W integral rotary cryocooler and passive heat transfer elements, maintaining the CCD at an operating temperature of 170 K. Analyses of the Earth\u27s obstruction of the instrument’s field of view and the impact of external heating on the instrument aperture established performance requirements and attitude constraints for the thermal control system. A high-fidelity test of a preliminary design was performed in a thermal vacuum chamber, prompting modifications to improve the thermal system design margins. This effort precedes the Critical Design Review milestone

CubeSat Single-Photon Detector Module for Performing In-Orbit Laser Annealing to Heal Radiation Damage

Silicon-based single-photon avalanche photodiodes (SPADs), widely considered for satellite-based quantum communications, suffer a constant increase of dark count rate (DCR) from radiation-induced proton displacement damage in their active areas. When this accumulated damage causes the DCR to exceed a certain threshold (for example, 10,000 counts per second), the SPADs become unreliable for quantum communications, limiting mission lifetime. Previous ground experiments showed that radiation-induced DCR of synthetically irradiated SPADs could be significantly improved by high-power laser annealing, a localized heating of SPADs’ active areas using a focused laser beam. The next step is therefore to demonstrate realtime laser annealing on constantly irradiated SPADs in actual low-Earth-orbit is viable. To facilitate this study, the University of Waterloo team built a miniaturized software controllable SPAD module as part of the annealing payload on CAPSat (Cool Annealing Payload Satellite), a 3U CubeSat satellite developed by a team from the University of Illinois Urbana-Champaign. We present the concept of in-orbit laser annealing and the electronic platform of the SPAD module containing four detectors supporting thermal and laser annealing and detector characterization. The CAPSat, launched and deployed in a low-Earth orbit at 400 km altitude from the International Space Station in October 2021, was intended to assess the viability of this approach before incorporating SPADs in future quantum satellite missions, especially in quantum receivers

Poor accuracy of freehand cup positioning during total hip arthroplasty

Several studies have demonstrated a correlation between the acetabular cup position and the risk of dislocation, wear and range of motion after total hip arthroplasty. The present study was designed to evaluate the accuracy of the surgeon’s estimated position of the cup after freehand placement in total hip replacement. Peroperative estimated abduction and anteversion of 200 acetabular components (placed by three orthopaedic surgeons and nine residents) were compared with measured outcomes (according to Pradhan) on postoperative radiographs. Cups were placed in 49.7° (SD 6.7) of abduction and 16.0° (SD 8.1) of anteversion. Estimation of placement was 46.3° (SD 4.3) of abduction and 14.6° (SD 5.9) of anteversion. Of more interest is the fact that for the orthopaedic surgeons the mean inaccuracy of estimation was 4.1° (SD 3.9) for abduction and 5.2° (SD 4.5) for anteversion and for their residents this was respectively, 6.3° (SD 4.6) and 5.7° (SD 5.0). Significant differences were found between orthopaedic surgeons and residents for inaccuracy of estimation for abduction, not for anteversion. Body mass index, sex, (un)cemented fixation and surgical approach (anterolateral or posterolateral) were not significant factors. Based upon the inaccuracy of estimation, the group’s chance on future cup placement within Lewinnek’s safe zone (5–25° anteversion and 30–50° abduction) is 82.7 and 85.2% for anteversion and abduction separately. When both parameters are combined, the chance of accurate placement is only 70.5%. The chance of placement of the acetabular component within 5° of an intended position, for both abduction and anteversion is 21.5% this percentage decreases to just 2.9% when the tolerated error is 1°. There is a tendency to underestimate both abduction and anteversion. Orthopaedic surgeons are superior to their residents in estimating abduction of the acetabular component. The results of this study indicate that freehand placement of the acetabular component is not a reliable method

Collaborative Ambulatory Orthopaedic Care in Patients with Hip and Knee Osteoarthritis: A Retrospective Comparative Cohort Study on Health Utilisation and Economic Outcomes

Objective: To evaluate a novel healthcare programme for the treatment of patients with hip and knee osteoarthritis in southern Germany in terms of clinical and health economic outcomes. The study is based on claims data from 2014 to 2017. Methods: We conducted a retrospective comparative cohort study of 9768 patients with hip and knee osteoarthritis, of whom 9231 were enrolled in a collaborative ambulatory orthopaedic care programme (intervention group), and 537 patients received usual orthopaedic care (control group). Key features of the programme are coordinated care, morbidity-adapted reimbursement and extended consultation times. Multivariable analysis was performed to determine effects on health utilisation outcomes. The economic analysis considered annual costs per patient from a healthcare payer perspective, stratified by healthcare service sector. Besides multivariable regression analyses, bootstrapping was used to estimate confidence intervals for predicted mean costs by group. Results: Musculoskeletal-disease-related hospitalisation was much less likely among intervention group patients than control group patients [odds ratio (OR): 0.079; 95% CI: 0.062–0.099]. The number of physiotherapy prescriptions per patient was significantly lower in the intervention group (RR: 0.814; 95% CI: 0.721–0.919), while the likelihood of participation in exercise programmes over one year was significantly higher (OR: 3.126; 95% CI: 1.604–6.094). Enrolment in the programme was associated with significantly higher ambulatory costs (€1048 vs. €925), but costs for inpatient care, including hospital stays, were significantly lower (€1003 vs. €1497 and €928 vs. €1300 respectively). Overall annual cost-savings were €195 per patient. Conclusions: Collaborative ambulatory orthopaedic care was associated with reduced hospitalisation in patients with hip and knee osteoarthritis. Health costs for programme participants were lower overall, despite higher costs for ambulatory care

Neurogenic inflammation after traumatic brain injury and its potentiation of classical inflammation

Background: The neuroinflammatory response following traumatic brain injury (TBI) is known to be a key secondary injury factor that can drive ongoing neuronal injury. Despite this, treatments that have targeted aspects of the inflammatory pathway have not shown significant efficacy in clinical trials. Main body: We suggest that this may be because classical inflammation only represents part of the story, with activation of neurogenic inflammation potentially one of the key initiating inflammatory events following TBI. Indeed, evidence suggests that the transient receptor potential cation channels (TRP channels), TRPV1 and TRPA1, are polymodal receptors that are activated by a variety of stimuli associated with TBI, including mechanical shear stress, leading to the release of neuropeptides such as substance P (SP). SP augments many aspects of the classical inflammatory response via activation of microglia and astrocytes, degranulation of mast cells, and promoting leukocyte migration. Furthermore, SP may initiate the earliest changes seen in blood-brain barrier (BBB) permeability, namely the increased transcellular transport of plasma proteins via activation of caveolae. This is in line with reports that alterations in transcellular transport are seen first following TBI, prior to decreases in expression of tight-junction proteins such as claudin-5 and occludin. Indeed, the receptor for SP, the tachykinin NK1 receptor, is found in caveolae and its activation following TBI may allow influx of albumin and other plasma proteins which directly augment the inflammatory response by activating astrocytes and microglia. Conclusions: As such, the neurogenic inflammatory response can exacerbate classical inflammation via a positive feedback loop, with classical inflammatory mediators such as bradykinin and prostaglandins then further stimulating TRP receptors. Accordingly, complete inhibition of neuroinflammation following TBI may require the inhibition of both classical and neurogenic inflammatory pathways.Frances Corrigan, Kimberley A. Mander, Anna V. Leonard and Robert Vin

Cellulose-Enriched Microbial Communities from Leaf-Cutter Ant (Atta colombica) Refuse Dumps Vary in Taxonomic Composition and Degradation Ability

Deconstruction of the cellulose in plant cell walls is critical for carbon flow through ecosystems and for the production of sustainable cellulosic biofuels. Our understanding of cellulose deconstruction is largely limited to the study of microbes in isolation, but in nature, this process is driven by microbes within complex communities. In Neotropical forests, microbes in leaf-cutter ant refuse dumps are important for carbon turnover. These dumps consist of decaying plant material and a diverse bacterial community, as shown here by electron microscopy. To study the portion of the community capable of cellulose degradation, we performed enrichments on cellulose using material from five Atta colombica refuse dumps. The ability of enriched communities to degrade cellulose varied significantly across refuse dumps. 16S rRNA gene amplicon sequencing of enriched samples identified that the community structure correlated with refuse dump and with degradation ability. Overall, samples were dominated by Bacteroidetes, Gammaproteobacteria, and Betaproteobacteria. Half of abundant operational taxonomic units (OTUs) across samples were classified within genera containing known cellulose degraders, including Acidovorax, the most abundant OTU detected across samples, which was positively correlated with cellulolytic ability. A representative Acidovorax strain was isolated, but did not grow on cellulose alone. Phenotypic and compositional analyses of enrichment cultures, such as those presented here, help link community composition with cellulolytic ability and provide insight into the complexity of community-based cellulose degradation.Biological and Environmental Research/[DE-FC02-07ER64494]/BER/Estados UnidosNational Science Foundation/[DGE-1256259]/NSF/Estados UnidosNational Science Foundation/[DEB-0747002]/NSF/Estados UnidosNational Science Foundation/[MCB-0702025]/NSF/Estados UnidosNational Institutes of Health/[T32 GM07215]/NIH/Estados UnidosUniversidad de Costa Rica/[]/UCR/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones/[]/MICITT/Costa RicaUniversity of Wisconsin-Madison's Hilldale Undergraduate Faculty Research Fellowship/[]//Estados UnidosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM