The mesenchymal stem cells of dental pulp (DPSCs) were isolated and characterized for the first time more than a decade ago as highly clonogenic cells that were able to generate densely calcified ...colonies. Now, DPSCs are considered to have potential as stem cell source for orthopedic and oral maxillofacial reconstruction, and it has been suggested that they may have applications beyond the scope of the stomatognathic system. To date, most studies have shown that, regardless of their origin in third molars, incisors, or exfoliated deciduous teeth, DPSCs can generate mineralized tissue, an extracellular matrix and structures type dentin, periodontal ligament, and dental pulp, as well as other structures. Different groups worldwide have designed and evaluated new efficient protocols for the isolation, expansion, and maintenance of clinically safe human DPSCs in sufficient numbers for various therapeutics protocols and have discussed the most appropriate route of administration, the possible contraindications to their clinical use, and the parameters to be considered for monitoring their clinical efficacy and proper biological source. At present, DPSC-based therapy is promising but because most of the available evidence was obtained using nonhuman xenotransplants, it is not a mature technology.
Various frameworks have been developed to guide organisations in embedding circular economy principles in their strategy and operational practice. However, there is a lack of studies analysing ...practical implementation of circular economy thinking in the higher education sector. Higher education institutions are strategic agents in supporting sustainable development through teaching, research and social outreach activities. They also represent a source of environmental impacts due to significant resource consumption and waste generation. This paper presents the first comprehensive study showing how higher education institutions can use an action-led step-by-step approach to build a business case and implement circular economy thinking in practice. The University of Manchester is used as an illustrative example of a large higher education institution. First, a background analysis and semi-structured interviews were carried out to determine the scope of the university's current sustainability policies and the ability of the management systems to respond to circular economy challenges. This was followed by stakeholder workshops to identify gaps and opportunities for building a business case for implementation of a circular economy. Finally, a critical assessment of the outcomes was carried out to identify further research needs for implementation of a circular economy in higher education institutions. Although focused on the higher education sector, the proposed action-led approach can be used by any organisation in the service sector looking to build more circular and sustainable business models.
The consumption of takeaway food is increasing worldwide. Single-use containers used for takeaway food represent a significant source of waste and environmental impacts due to their low ...recyclability. Consequently, it is important to identify the best available alternatives and improvement opportunities to reduce the environmental impacts of fast-food containers. For these purposes, this study estimates and compares for the first time the life cycle impacts of three most widely-used types of takeaway container: aluminium, polypropylene and extruded polystyrene. These are also compared to reusable polypropylene containers. The findings suggest that single-use polypropylene containers are the worst option for seven out of 12 impacts considered, including global warming potential. They are followed by the aluminium alternative with five highest impacts, including depletion of ozone layer and human toxicity. Overall, extruded polystyrene containers have the lowest impacts due to the lower material and electricity requirements in their manufacture. They are also the best option when compared to reused takeaway polypropylene containers, unless the latter are reused 3–39 times. The number of uses needed for the reusable “Tupperware” polypropylene food savers is even higher, ranging from 16 to 208 times, with terrestrial ecotoxicity being always higher than for extruded polystyrene, regardless of the number of uses. However, extruded polystyrene containers are currently not recycled and cannot be considered a sustainable option. If they were recycled in accordance with the European Union 2025 policy on waste packaging, most of their impacts would be reduced by >18%, while also reducing littering and negative effects on marine organisms. Most of the impacts of the other two types of container would also be reduced (>20%) through increased recycling. Implementing the European Union 2025 policy on recycling of waste packaging would reduce all the impacts by 2%–60%, including a 33% reduction in global warming potential. Based on 2025 million takeaway containers used annually in the European Union, the latter would save 61,700 t CO2 eq./yr, equivalent to the emissions of 55,000 light-duty vehicles. The outcomes of this study will be of interest to packaging manufacturers, food outlets, policy makers and consumers.
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•First LCA of takeaway containers: aluminium, polystyrene (EPS) and polypropylene (PP).•EPS containers have the lowest impacts for all 12 impacts considered.•PP containers have to be reused 3–208 times to have lower impacts than EPS.•Recycling EPS containers would reduce most of the impacts by >18%.•The EU 2025 recycling policy would reduce the impacts of all containers by 2%–60%.
Summary
The circular economy (CE) is essential for decoupling economic growth from resource consumption and environmental impacts. However, effective implementation requires a systemic change across ...supply chains, involving both technological and nontechnological innovations. Frameworks are beginning to emerge to foster CE thinking in organizations. However, literature review carried out as part of this research has revealed gaps in their ability to fulfil CE requirements. Furthermore, few frameworks provide support on how CE requirements may be implemented. To address these issues, this article presents a new framework, BECE (backcasting and eco‐design for the circular economy), to ensure that businesses can implement CE requirements more readily. BECE empowers organizations to tackle the CE holistically by embedding the concept into corporate decision making and by bringing operational and systems thinking together, thus increasing the likelihood of successful implementation. The potential of the BECE framework was tested through a pilot workshop focusing on the development of a CE business model through redesign of products and supply chains. Using vacuum cleaners as an illustrative case study, several product design and supply‐chain alternatives were identified, including the development of scenarios and action plans for their implementation at the business level. Although the case study focuses on a particular product, the BECE framework is generic and applicable across different products and business sectors.
ABSTRACT
This article seeks to understand why community forestry enterprises in the Mayan rainforest of Mexico are losing ground, while middlemen and manufacturers are regaining control over forestry ...resources. It focuses on the case of the Ejido San Felipe Oriente where an NGO codesigned a commercialization platform with the objective of bringing together local cooperatives to negotiate in the market from a position of strength. The project was hampered by an internal rupture in the ejido; in investigating this rupture, the authors use the concept of institutional bricolage to understand local power struggles, and the theory of gradual change to search for historical causal mechanisms. They find that the proximate causes of the rupture were family rivalries, suspicions of embezzlement, unfair exclusions, and the disruption of customary practices regarding the distribution of monetary benefits. However, historical continuities lay beneath the power struggle: ejidos in the Yucatan Peninsula have used their function as intermediaries to subordinate local interests rather than promote endogenous development. The authors advocate for an institutional design process that takes account of the unconscious and taken‐for‐granted meanings that influence institutional adaptation; they encourage development practitioners promoting community forestry enterprises in the Mayan rainforest of Mexico to address historical continuities in local institutions as a focal target of development interventions.
Oxidative stress (OS) is the imbalance between oxidant and antioxidant molecules, in favor of oxidants, that causes aging and disease. Many studies have been published that demonstrate the ...relationship between OS and human health and disease; however, the following questions arise: (i) how are we sure that the OS is present in a biological process? (ii) Is the OS reported in the different investigations equivalent? (iii) What are the best oxidant and antioxidant markers for OS diagnosis? (iv) Can we establish the types and the intensity of the OS? (v) Does OS index could be useful for research and/or application in clinical medicine? In this regard, several indexes have been proposed to measure OS in humans relative to the state of health and disease, among which the following can be highlighted: Oxidative Stress Index (OSI), Tiol Ratios (-SH/TT, -SS/-SH, and-SS/TT), Glutathione Ratio (GSSG/GSH), Oxidative Stress Score (OSS), and OXY-index. Therefore, the aim of this review is to present the state of the art of knowledge about OS indexes for diagnosis of health or disease in humans. We searched for articles in English or Spanish in the PubMed/MEDLINE and Scopus electronic databases published up until May 2019. The keywords used were “oxidative stress,” “index,” and “oxidative stress index.” It was identified 11479 records in both databases, and 490 articles were analyzed. Our review suggests that all indexes analyzed allow diagnose and differentiate the OS related to human health and disease. Also, the studies on OSI, Oxy-score, and OSS indexes have proven to be reliable, practical, and with clinical utility. However, it is necessary to continue with longitudinal studies, especially assess the usefulness of the indexes in the clinical prognosis, and make comparative studies between the different indexes.
To assess the association between hot flashes (HFs) severity and oxidative stress (OS) in Mexican postmenopausal women.
A cross-sectional study was carried out with perimenopausal women aged 40-59 ...years community-dwelling from Mexico City, Mexico. They participated in Menopause and Oxidative Stress Project. The baseline sample consisted of 476 women recruited to participate; 161 women were excluded due to different reasons. Hence, 315 women were selected to establish two groups, a) 145 premenopausal women (yet with menstrual bleeding), and b) 170 postmenopausal women (without menses). All women were free of cardiovascular, kidney, hepatic or cancer disease, and without antioxidant supplement intake for at least six months prior to the beginning of the study; none had previously received hormone therapy. As OS markers, we measured plasma malondialdehyde using the TBARS assay, erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPx), uric acid, and total antioxidant status; also, we calculated SOD/GPx ratio, antioxidant gap and an oxidative stress score ranging from 0 to 7. The HFs were evaluated using the Menopause Rating Scale. The women completed Spanish version of the Athens Insomnia Scale, Zung Self-Rating Anxiety Scale and Zung Self-Rating Depression Scale and a questionnaire of pro-oxidant factors.
Stress score increased with HFs severity (mild 2.7±0.17, moderate 2.9±0.20 and severe 3.7±0.20, p = 0.001) in postmenopausal women. We observed a positive correlation between HFs severity and stress score, r = 0.247 (p = 0.001) in postmenopausal women; other test scores were not correlated. Severe HFs were a risk factor for OS (OR = 5.12, 95%CI: 1.99-13.17, p<0.05) in an adjusted multivariate analysis by different postmenopausal symptoms and pro-oxidant factors; we did not see any association in premenopausal women.
Our findings suggest an association between HFs severity and OS in Mexican postmenopausal women.
Nature's complexity is intriguing, but the circumstances determining whether or how order emerges from such complexity remains a matter of extensive research. Using the geographical distributions and ...food preferences of all terrestrial mammal species with masses >3 kg, we show that large mammals group into feeding guilds (species exploiting similar resources) and that these guilds form trophic structures that vary across biomes globally. We identify five trophic structures closely matching climate variability and named them boreal, temperate, semiarid, seasonal tropical and humid tropical owing to their relative overlap with the distribution of biomes. We also find that human activities simplify trophic structures, generally transitioning them to species-poorer states. Detected transitions include boreal and temperate structures becoming depauperate or seasonal- and humid-tropical becoming semiarid. Whether the observed generalities among trophic structures of large mammals are indicative of patterns across whole food webs is matter for further investigation. The results help refine projections of the effects of environmental change on the trophic structure of large mammals.
We apply a move max matched‐filter method to detect heightened seismicity triggered in the San Jacinto fault (SJF) zone, by the 2014 Mw 7.2 Papanoa, Mexico earthquake. The move max matched filter ...detects 5.4 and 1.7 times the number of earthquakes in the Southern California Seismic Network catalog and those detected by the matched‐filter method, respectively. The seismicity rate increases significantly ~3.5 hr after the passage of the teleseismic waves and persists above the background level for about 1 week. This observation of delayed triggering may imply that dynamic stresses had initiated a time‐dependent advance to failure or a secondary process. A highly active triggered patch is located ~10 km west of the SJF near Anza, on a previously unmapped fault. Focal mechanisms and a best fit plane suggest a normal fault perpendicular to the SJF. The unmapped fault may indicate higher seismic hazard in the surrounding areas if a large earthquake nucleated around the Anza seismic gap.
Key Points
The move max matched‐filter method shows higher capability than traditional matched‐filter method in detecting small earthquakes
More than one physical mechanism can explain the delayed and sustained triggering of small earthquakes in the San Jacinto Fault region
The unmapped fault distinguished in this study may indicate more serious seismic hazards in the Anza region
Periodontitis is a chronic disease that begins with a period of inflammation of the supporting tissues of the teeth table and then progresses, destroying the tissues until loss of the teeth occurs. ...The restoration of the damaged dental support apparatus is an extremely complex process due to the regeneration of the cementum, the periodontal ligament, and the alveolar bone. Conventional treatment relies on synthetic materials that fill defects and replace lost dental tissue, but these approaches are not substitutes for a real regeneration of tissue. To address this, there are several approaches to tissue engineering for regenerative dentistry, among them, the use of stem cells. Mesenchymal stem cells (MSC) can be obtained from various sources of adult tissues, such as bone marrow, adipose tissue, skin, and tissues of the orofacial area. MSC of dental origin, such as those found in the bone marrow, have immunosuppressive and immunotolerant properties, multipotency, high proliferation rates, and the capacity for tissue repair. However, they are poorly used as sources of tissue for therapeutic purposes. Their accessibility makes them an attractive source of mesenchymal stem cells, so this review describes the field of dental stem cell research and proposes a potential mechanism involved in periodontal tissue regeneration induced by dental MSC.
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