Increased demand for responsive, cost efficient, and sustainable operations requires service parts consideration and adoption of new business models and solutions that span the entire life-cycle of ...products. Many firms are turning to big data analytics. Though service parts managers have long relied on analysis & optimization, big data analytics are considered to be more encompassing and thus especially promising. Herein, big data and its related applications are proposed as a means of improving service parts management practices. More specifically, data collected from interviews with service parts managers is used to construct a framework depicting the challenges of service parts management. This framework then serves as the basis for big data related proposals for overcoming the highlighted challenges. Thus, the research answers the call for service parts management related frameworks while providing a number of suggestions for managerial consideration and scholarly investigation.
•Service parts management is a key component of advancing the circular economy.•There is a dearth of understanding regarding data-driven decision-making needs.•Open-ended interviews and grounded theory are used to develop a framework.•The results provide theory-based research directions for big data in service parts.
Although the literature on product recalls is informative, our understanding of these events is still in its infancy. To promote and guide future research in this nascent area, we engaged in a ...two‐step process that included a systematic review and categorization of product recall‐related literature and interviews with executives from along the entire supply chain. By oscillating between findings in the literature and themes that emerged during our interactions with executives, we discovered several research opportunities that have yet to be systematically examined by scholars. We also highlight four underutilized theories in supply chain management research—upper echelons theory, punctuated equilibrium theory, enactment theory, and justice theory—that could help guide future research in this area. For managers, this study reveals insights related to four key aspects of product recalls: (1) recall precursors (factors that may lead to recalls); (2) the recall process; (3) the impact of recalls; and (4) mitigation approaches (mechanisms firms can employ to reduce the impact of recalls). For scholars, our study identifies several emergent research opportunities and theoretical lenses in the same four areas and thus serves as a road map for future product recall research.
Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor ...approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative “urban syndromes” concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.
Bioengineering of a thermophilic enzyme starting from a mesophilic scaffold has proven to be a significant challenge, as several stabilizing elements have been proposed to be the foundation of ...thermal stability, including disulfide bridges, surface loop reduction, ionic pair networks, proline substitutions and aromatic clusters. This study emphasizes the effect of increasing the rigidity of human carbonic anhydrase II (HCA II; EC 4.2.1.1) via incorporation of proline residues at positions 170 and 234, which are located in surface loops that are able to accommodate restrictive main‐chain conformations without rearrangement of the surrounding peptide backbone. Additionally, the effect of the compactness of HCA II was examined by deletion of a surface loop (residues 230–240) that had been previously identified as a possible source of thermal stability for the hyperthermophilic carbonic anhydrase isolated from the bacterium Sulfurihydrogenibium yellowstonense YO3AOP1. Differential scanning calorimetry analysis of these HCA II variants revealed that these structural modifications had a minimum effect on the thermal stability of the enzyme, while kinetic studies showed unexpected effects on the catalytic efficiency and proton transfer rates. X‐ray crystallographic analysis of these HCA II variants showed that the electrostatic potential and configuration of the highly acidic loop (residues 230–240) play an important role in its high catalytic activity. Based on these observations and previous studies, a picture is emerging of the various components within the general structural architecture of HCA II that are key to stability. These elements may provide blueprints for rational thermal stability engineering of other enzymes.
Database
Structural data have been submitted to the Protein Data Bank under accession numbers 4QK1 (K170P), 4QK2 (E234P) and 4QK3 (Δ230—240).
This study examines the impact of the incorporation of rigidity by the addition of proline residues and the effect of compactness by way of deletion of a surface loop, on the structure, stability, and catalysis of human carbonic anhydrase II. These structural modifications had minimum effect on the thermal stability of the enzyme while effecting its catalytic efficiency.
Glacial lake outburst floods (GLOFs) are among the most serious cryospheric hazards for mountain communities. Multiple studies have predicted the potential risks posed by rapidly expanding glacial ...lakes in the Sagarmatha (Mt. Everest) National Park and Buffer Zone of Nepal. People’s perceptions of such cryospheric hazards can influence their actions, beliefs, and responses to those hazards and associated risks. This study provides a systematic approach that combines household survey data with ethnography to analyze people’s perceptions of GLOF risks and the socioeconomic and cultural factors influencing their perceptions. A statistical logit model of household data showed a significant positive correlation between the perceptions of GLOF risks and livelihood sources, mainly tourism. Risk perceptions are also influenced by spatial proximity to glacial lakes and whether a village is in potential flood zones. The 2016 emergency remediation work implemented in the
Imja Tsho
(glacial lake) has served as a cognitive fix, especially in the low-lying settlements. Much of uncertainty and confusions related GLOF risks among locals can be attributed to a disconnect between how scientific information is communicated to the local communities and how government climate change policies have been limited to awareness campaigns and emergency remediation efforts. A sustainable partnership of scientists, policymakers, and local communities is urgently needed to build a science-driven, community-based initiative that focuses not just in addressing a single GLOF threat but develops on a comprehensive cryospheric risk management plan and considers opportunities and challenges of tourism in the local climate adaptation policies.
This article examines the distribution of parks in Baltimore, Maryland, as an environmental justice issue. In addition to established methods for measuring distribution of and access to parks, we ...employ a novel park service area approach that uses Thiessen polygons and dasymetric reapportioning of census data to measure potential park congestion as an equity outcome measure. We find that a higher proportion of African Americans have access to parks within walking distance, defined as 400 meters or less, than whites, but whites have access to more acreage of parks within walking distance than blacks. A needs-based assessment shows that areas with the highest need have the best access to parks but also have access to less acreage of parks compared to low-need areas. Park service areas that are predominantly black have higher park congestion than areas that are predominantly white, although differences are less apparent at the city level than at the metropolitan level. Following Iris Young and others, we argue that conceptions of justice must move beyond distributive justice and address the social and institutional mechanisms that generate inequities. For Baltimore, we examine how segregation ordinances, racial covenants, improvement associations, the Home Owners Loan Corporation, and the Parks and Recreation Board created separate black spaces historically underserved with parks. These mechanisms ultimately fueled middle-class flight and suburbanization and black inheritance of much of Baltimore's space, including its parks. If justice demands just distribution justly achieved, the present-day pattern of parks in Baltimore should be interpreted as environmental injustice.
The carbonic anhydrases (CAs) are a family of mostly zinc metalloenzymes that catalyze the reversible hydration/dehydration of CO2 into bicarbonate and a proton. Human isoform CA II (HCA II) is ...abundant in the surface epithelial cells of the gastric mucosa, where it serves an important role in cytoprotection through bicarbonate secretion. Physiological inhibition of HCA II via the bile acids contributes to mucosal injury in ulcerogenic conditions. This study details the weak biophysical interactions associated with the binding of a primary bile acid, cholate, to HCA II. The X‐ray crystallographic structure determined to 1.54 Å resolution revealed that cholate does not make any direct hydrogen‐bond interactions with HCA II, but instead reconfigures the well ordered water network within the active site to promote indirect binding to the enzyme. Structural knowledge of the binding interactions of this nonsulfur‐containing inhibitor with HCA II could provide the template design for high‐affinity, isoform‐specific therapeutic agents for a variety of diseases/pathological states, including cancer, glaucoma, epilepsy and osteoporosis.
Degenerative changes of the sacroiliac joint have been implicated as a cause of lower back pain in adults. The purpose of this study was to determine the prevalence of sacroiliac joint degeneration ...in asymptomatic patients.
Five hundred consecutive pelvic computed tomography (CT) scans, made at a tertiary-care medical center, of patients with no history of pain in the lower back or pelvic girdle were retrospectively reviewed and analyzed for degenerative changes of the sacroiliac joint. After exclusion criteria were applied, 373 CT scans (746 sacroiliac joints) were evaluated for degenerative changes. Regression analysis was used to determine the association between age and the degree of sacroiliac joint degeneration.
The prevalence of sacroiliac joint degeneration was 65.1%, with substantial degeneration occurring in 30.5% of asymptomatic subjects. The prevalence steadily increased with age, with 91% of subjects in the ninth decade of life displaying degenerative changes.
Radiographic evidence of sacroiliac joint degeneration is highly prevalent in the asymptomatic population and is associated with age. Caution must be exercised when attributing lower back or pelvic girdle pain to sacroiliac joint degeneration seen on imaging.
Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
The carbonic anhydrases (CAs; EC 4.2.1.1) are a family of metalloenzymes that catalyze the reversible hydration of carbon dioxide (CO2) and dehydration of bicarbonate (HCO3 (-)) in a two-step ...ping-pong mechanism: Formula: see text CAs are ubiquitous enzymes and are categorized into five distinct classes (α, β, γ, δ and ζ). The α-class is found primarily in vertebrates (and the only class of CA in mammals), β is observed in higher plants and some prokaryotes, γ is present only in archaebacteria whereas the δ and ζ classes have only been observed in diatoms.The focus of this chapter is on α-CAs as the structure-function relationship is best understood for this class, in particular for humans. The reader is referred to other reviews for an overview of the structure and catalytic mechanism of the other CA classes. The overall catalytic site structure and geometry of α-CAs are described in the first section of this chapter followed by the kinetic studies, binding of CO2, and the proton shuttle network.
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