Comparison of structural performance of one- and two-bay rotary joints for truss applications

The structural performance of one- and two-bay large-diameter discrete-bearing rotary joints was addressed for application to truss-beam structures such as the Space Station Freedom. Finite element analyses are performed to determine values for rotary joint parameters that give the same bending vibration frequency as the parent truss beam. The structural masses and maximum internal loads of these joints are compared to determine their relative structural efficiency. Results indicate that no significant difference exists in the masse of one- and two-bay rotary joints. This conclusion is reinforced with closed-form calculations of rotary joint structural efficiency in extension. Also, transition truss-member loads are higher in the one-bay rotary joint. However, because of the increased buckling strength of these members, the external load-carrying capability of the one-bay concept is higher than that of the two-bay concept

Illegal Waste Transport and the Czech Republic: An Environmental Sociological Perspective

In late 2005 Czech authorities first began to discover substantial amounts of municipal waste illegally transported from Germany to the Czech Republic. The dumping of more than 30000 tonnes of German waste in 'black dumps' throughout the Bohemian countryside raised social, economic, and political questions about how to mitigate the negative human health and environmental impacts and prevent dumping in the future. In addition to prompting practical policy questions, the situation challenges sociologists to theorise the causes, effects, and possible responses to the problem. This article draws on the environmental sociological Treadmill of Production (ToP) theory to examine the role of the state in managing the crisis. The author presents the history of the Bohemian illegal waste problem and then describes and analyses relevant waste management policies in the Czech Republic, Germany, and the European Union in the light of the ToP theory, which hypothesises that environmental degradation is caused primarily by institutional political-economic forces, and that the protection of environmental quality can be achieved only through structural reform. The dilemma of illegal waste shipment highlights the difficult role of the government, which must balance its responsibilities to protect environmental quality and human health and promote commerce and economic growth in an international context. Data from interviews and documentary analysis are used to describe the case study and test the ToP theory. The author concludes that while the ToP theory is useful for analysing the illegal waste issue by highlighting the structural character of the problem, some refinement of the theory may be necessary to better understand this case study

Materials for Biomedical Applications

This paper discusses two ceramic material systems for selective laser sintering (SLS) that are being developed for biomedical applications for use in repair of bone defects. SLS is the preferred method of fabricating ceramic implants that exhibit well defined porous microstructures. Implants fabricated in this. manner have proven effective in-vivo showing excellent biocompatibility as well as considerable osseous integration and remodeling of the imp'ant materialMechanical Engineerin

Silver linings: will the COVID-19 pandemic instigate long overdue mental health support services for healthcare workers?

Summary: A study in this month’s journal adds to the growing body of evidence regarding the potential mental health impacts on frontline healthcare staff working during the COVID-19 pandemic. As clinical academics representing critical care, nursing, and medicine, and a psychologist guiding support for frontline health and social workers, we offer our perspectives on this study. We discuss the balance between pragmatic and rigorous data collection on this topic and offer perspectives on the observed differential impact on nurses. Finally, we suggest that the pandemic might have a positive effect by instigating more robust mental health support services for National Health Service workers

Reshaping Maine Woods Destinations for Twenty-First-Century Tourists

Maine’s rim counties—here called the Maine Woods region—suffer from chronic economic and community distress, marked by declines in several resource-based industries, an ongoing youth exodus, and a rapidly aging population. Nonetheless, many encouraging new ventures are helping to revitalize the Maine Woods economy and communities, and tourism and recreation should play a central role in these efforts. This article focuses on initiatives launched through a partnership between the 16-member Maine Woods Consortium and the Maine Office of Tourism designed to reinvigorate Maine Woods’ recreation and hospitality offerings and to enrich amenities in the region’s gateway communities

Spinal Cord Compression Secondary to Metastatic Sinonasal Undifferentiated Carcinoma

Sinonasal undifferentiated carcinoma (SNUC) is a rare malignancy of the upper airways and anterior skull base that carries a poor prognosis. The tumor is known to be invasive into the surrounding structures of the skull base and brain. To date, there is only one existing case report documenting drop metastasis to the intradural extramedullary spinal cord. To the best of our knowledge, we present the second case of metastatic SNUC to the spine. This report describes a 59-year-old male with a history of head and neck SNUC who presented with thoracic back pain and bilateral lower extremity paresis. Neuroimaging demonstrated an extradural thoracic mass with severe spinal cord compression. The patient underwent thoracic laminectomy and fusion for decompression of the spinal cord and internal stabilization. The pathology returned as SNUC. The patient was subsequently lost to follow-up from our institution. Metastatic SNUC is rare. We discuss the relevant clinical imaging and review the literature. Such a malignancy portends a very poor prognosis

Osteocyte dysfunction promotes osteoarthritis through MMP13-dependent suppression of subchondral bone homeostasis.

Osteoarthritis (OA), long considered a primary disorder of articular cartilage, is commonly associated with subchondral bone sclerosis. However, the cellular mechanisms responsible for changes to subchondral bone in OA, and the extent to which these changes are drivers of or a secondary reaction to cartilage degeneration, remain unclear. In knee joints from human patients with end-stage OA, we found evidence of profound defects in osteocyte function. Suppression of osteocyte perilacunar/canalicular remodeling (PLR) was most severe in the medial compartment of OA subchondral bone, with lower protease expression, diminished canalicular networks, and disorganized and hypermineralized extracellular matrix. As a step toward evaluating the causality of PLR suppression in OA, we ablated the PLR enzyme MMP13 in osteocytes while leaving chondrocytic MMP13 intact, using Cre recombinase driven by the 9.6-kb DMP1 promoter. Not only did osteocytic MMP13 deficiency suppress PLR in cortical and subchondral bone, but it also compromised cartilage. Even in the absence of injury, osteocytic MMP13 deficiency was sufficient to reduce cartilage proteoglycan content, change chondrocyte production of collagen II, aggrecan, and MMP13, and increase the incidence of cartilage lesions, consistent with early OA. Thus, in humans and mice, defects in PLR coincide with cartilage defects. Osteocyte-derived MMP13 emerges as a critical regulator of cartilage homeostasis, likely via its effects on PLR. Together, these findings implicate osteocytes in bone-cartilage crosstalk in the joint and suggest a causal role for suppressed perilacunar/canalicular remodeling in osteoarthritis

Do the Potential Benefits of Metal-on-Metal Hip Resurfacing Justify the Increased Cost and Risk of Complications?

Metal-on-metal hip resurfacing arthroplasty (MoM HRA) may offer potential advantages over total hip arthroplasty (THA) for certain patients with advanced osteoarthritis of the hip. However, the cost effectiveness of MoM HRA compared with THA is unclear. The purpose of this study was to compare the clinical effectiveness and cost-effectiveness of MoM HRA to THA. A Markov decision model was constructed to compare the quality-adjusted life-years (QALYs) and costs associated with HRA versus THA from the healthcare system perspective over a 30-year time horizon. We performed sensitivity analyses to evaluate the impact of patient characteristics, clinical outcome probabilities, quality of life and costs on the discounted incremental costs, incremental clinical effectiveness, and the incremental cost-effectiveness ratio (ICER) of HRA compared to THA. MoM HRA was associated with modest improvements in QALYs at a small incremental cost, and had an ICER less than $50,000 per QALY gained for men younger than 65 and for women younger than 55. MoM HRA and THA failure rates, device costs, and the difference in quality of life after conversion from HRA to THA compared to primary THA had the largest impact on costs and quality of life. MoM HRA could be clinically advantageous and cost-effective in younger men and women. Further research on the comparative effectiveness of MoM HRA versus THA should include assessments of the quality of life and resource use in addition to the clinical outcomes associated with both procedures. Level I, economic and decision analysis. See Guidelines for Authors for a complete description of levels of evidence

Asian Longhorned Tick

The Asian longhorned tick (Haemophysalis longicorns Neumann; alternative names include Asian longhorned tick, Asian tick, bush tick, New Zealand cattle tick) is a species of hard tick in the family Ixodidae. It is native to eastern China, Japan, the Russian Far East and Korea. It has also established in Australia, New Zealand and several Pacific islands, where it is considered a severe exotic pest of livestock. In late 2017, the United States Department of Agriculture’s National Veterinary Services Laboratories (NVSL) confirmed the presence of the Asian longhorned tick in the United States. These ticks were first identified in New Jersey, but have since been found in archival samples from West Virginia as far back as 2010. The origin of the tick in the US remains unknown. Some possible routes of entry include entering on domestic pets, horses, livestock or humans. The real impact of the introduction of this tick into the US is not clear at this time, but animal health officials are concerned about potential detrimental impacts on livestock and wildlife

Leveraging Library Ecology: Growing Beyond Boundaries to Cultivate a Sustainable Knowledge Community Through Team-Based Librarianship

Higher education increasingly challenges libraries to thrive while adapting to fiscal realities, imploring institutions to accomplish more with less, and leverage assets creatively. When competing demands vie for attention, interdisciplinary concepts such as sustainability may be neglected, or simply absent from a library’s mission. A team-based community of librarians can galvanize existing assets wherever they reside within an organization. This approach requires that librarians transcend traditional boundaries to reveal untapped or underutilized expertise. Interdepartmental teams within a library can address topics difficult to assign to one designated specialist, and access the education, interests, or networks possessed by multiple individuals across an organization. A matrix model addressing this concept has been administered at K-State Libraries, and the following paper provides expanded insight into how such concepts have been handled within the organization