338 research outputs found
A New Look at ISTA in Iowa
In early April of this year, plans of the Iowa Academy of Science to form a new section for Science Teachers within the Academy were presented to Betty Goettsch, president of the ISTA by Dr. Robert Yager, a representative of the executive council of Iowa Academy of Science. Dr. Yager suggested that the ISTA might be interested in considering the opportunity for affiliation in this new division
Sortilin Is Upregulated in Osteoarthritis-Dependent Cartilage Calcification and Associated with Cellular Senescence.
Osteoarthritis (OA) is a chronic joint disease characterized by articular cartilage calcification, loss of articular cartilage, bone changes, pain, and disability. Cartilage calcification is one hallmark of OA and is predominantly caused by basic calcium crystals formed due to an imbalance of the pyrophosphate pathway. Sortilin is a transmembrane protein that contributes to vascular calcification in atherosclerosis by externalizing alkaline phosphatase (ALP)-containing vesicles. Calcification in atherosclerosis and osteoarthritis has been associated with cellular senescence. The aim of this study was to investigate the potential role of sortilin and senescence in osteoarthritis-dependent cartilage calcification. Osteoarthritic cartilage from human knee joints was collected after joint replacement, and samples were analyzed by immunohistochemistry and quantitative RT-PCR analysis. Human chondrocytes were treated with osteogenic medium for up to 21 days to induce calcification. Western blots for sortilin and ALP, as well as an ALP activity assay, were performed. Human chondrocytes were treated with mitomycin C to induce senescence, and sortilin expression was quantified at the protein and gene levels. Sections of knee joints from a murine model of osteoarthritis were stained for sortilin and p16 and analyzed by immunohistochemistry. Treatment of wild-type chondrocytes using an osteogenic medium similar to human chondrocytes was performed. Osteoarthritic cartilage from mouse and human knee joints showed an increased number of sortilin and p16-positive chondrocytes compared to healthy cartilage. This observation was corroborated by increased gene expression of sortilin and p16 in mild and moderate osteoarthritic cartilage samples. To investigate the mechanism of sortilin regulation, human chondrocytes were treated with osteogenic medium to induce calcification. Sortilin protein levels and expression were increased after 7 days of stimulation, whereas ALP levels and activity were upregulated after 21 days of stimulation. Similar observations were made in a murine osteoarthritis model. Mechanistically, senescent chondrocytes induced by mitomycin C showed an upregulation of sortilin and ALP gene expression compared to non-senescent chondrocytes. Our data indicate that sortilin and ALP are upregulated during cartilage calcification, which is associated with chondrocyte senescence and thus might contribute to the pathogenesis of osteoarthritis. Cellular senescence seems to induce sortilin expression
Prevalence and perspectives of illegal trade in cacti and succulent plants in the collector community
Although illegal wildlife trade (IWT) represents a serious threat to biodiversity, research into the prevalence of illegal plant collection and trade remains scarce. Because cacti and succulents are heavily threatened by overcollection for often illegal, international ornamental trade, we surveyed 441 members of the cacti and succulent hobbyist collector community with a mixed quantitative and qualitative approach. We sought to understand collector perspectives on the Convention on the International Trade in Endangered Species of Wild Flora and Fauna (CITES) and on the threats IWT poses to cactus and succulent conservation. Most respondents (74% of 401 respondents) stated that illegal collection in cacti and succulents represents a “very serious problem” and that the problem of wild plant collection is increasing (72% of 319 respondents). Most forms of illegal collection and trade were seen as very unacceptable by respondents. Self-reported noncompliance with CITES rules was uncommon (11.2% of 418 respondents); it remains a persistent problem in parts of the cacti and succulent hobbyist community. People engaging in rule breaking, such as transporting plants without required CITES documents, generally did so knowingly. Although 60.6% of 381 respondents regarded CITES as a very important tool for conservation, sentiment toward CITES and its efficacy in helping species conservation was mixed. Collectors in our survey saw themselves as potentially playing important roles in cactus and succulent conservation, but this potential resource remains largely untapped. Our results suggest the need for enhanced consultation with stakeholders in CITES decision-making. For challenging subjects like IWT, developing evidence-based responses demands deep interdisciplinary engagement, including assessing the conservation impact of species listings on CITES appendices
High proportion of cactus species threatened with extinction
This is the author accepted manuscript. The final version is available from Nature Publishing Group via the DOI in this record.Consejo Nacional de Ciencia y Tecnologí
Assessing the cost of global biodiversity and conservation knowledge
Knowledge products comprise assessments of authoritative information supported by
standards, governance, quality control, data, tools, and capacity building mechanisms.
Considerable resources are dedicated to developing and maintaining knowledge
products for biodiversity conservation, and they are widely used to inform policy and
advise decision makers and practitioners. However, the financial cost of delivering this
information is largely undocumented. We evaluated the costs and funding sources for
developing and maintaining four global biodiversity and conservation knowledge
products: The IUCN Red List of Threatened Species, the IUCN Red List of
Ecosystems, Protected Planet, and the World Database of Key Biodiversity Areas.
These are secondary data sets, built on primary data collected by extensive networks
of expert contributors worldwide. We estimate that US116-204
million), plus 293 person-years of volunteer time (range: 278-308 person-years) valued
at US12-16 million), were invested in these four knowledge
products between 1979 and 2013. More than half of this financing was provided
through philanthropy, and nearly three-quarters was spent on personnel costs. The
estimated annual cost of maintaining data and platforms for three of these knowledge
products (excluding the IUCN Red List of Ecosystems for which annual costs were not
possible to estimate for 2013 ) is US6.2-6.7 million).
We estimated that an additional US12 million. These costs
are much lower than those to maintain many other, similarly important, global
knowledge products. Ensuring that biodiversity and conservation knowledge products
are sufficiently up to date, comprehensive and accurate is fundamental to inform
decision-making for biodiversity conservation and sustainable development. Thus, the
development and implementation of plans for sustainable long-term financing for them
is critical
Surficial Geology, Soils, and Plant Zonation Ross Biological Area
Plant distribution is investigated with regard to geologic, geomorphic, and pedologic influences. Little is known about the soil-plant relationship of native species. This study attempts to develop a basic concept that the native plant zonation can be described in terms of the above three factors simply on the basis of routine field investigations. Further studies may then be designed to bring about a more quantitative understanding of the actual nutrient and moisture regimes under which certain native species will be most commonly found
Magnesium but not nicotinamide prevents vascular calcification in experimental uraemia
BACKGROUND: Optimal phosphate control is an unmet need in chronic kidney disease (CKD). High serum phosphate increases calcification burden and is associated with mortality and cardiovascular disease in CKD. Nicotinamide (NA) alone or in combination with calcium-free phosphate binders might be a strategy to reduce phosphate levels and calcification and thus impact cardiovascular disease in CKD. METHODS: We studied the effect of NA alone and in combination with magnesium carbonate (MgCO3) as a potential no
Osteoprotegerin production by breast cancer cells is suppressed by dexamethasone and confers resistance against TRAIL-induced apoptosis
ABSTRACT Osteoprotegerin (OPG) is a decoy receptor for receptor activator of NF-kB ligand (RANKL) and TNF-related apoptosis-inducing ligand (TRAIL). While RANKL is essential for osteoclastogenesis and facilitates breast cancer migration into bone, TRAIL promotes breast cancer apoptosis. We analyzed the expression of OPG and TRAIL and its modulation in estrogen receptor-positive MCF-7 cells and receptor-negative MDA-MB-231 cells. In both cells, OPG mRNA levels and protein secretion were dose-and time-dependently enhanced by interleukin (IL)-1b and suppressed by dexamethasone. In contrast to MCF-7 cells, MDA-MB-231 abundantly expressed TRAIL mRNA, which was enhanced by IL-1b and inhibited by dexamethasone. TRAIL activated pro-apoptotic caspase-3, -7, and poly-ADP-ribose polymerase and decreased cell numbers of MDA-MB-231, but had no effect on MCF-7 cells. Gene silencing siRNA directed against OPG resulted in a 31% higher apoptotic rate compared to non-target siRNA-treated MDA-MB-231 cells. Furthermore, TRAIL induced significantly less apoptosis in cells cultured in conditioned media (containing OPG) compared to cells exposed to TRAIL in fresh medium lacking OPG ( P < 0.01) and these protective effects were reversed by blocking OPG with its specific ligand RANKL ( P < 0.05). The association between cancer cell survival and OPG production by MDA-MB-231 cells was further supported by the finding, that modulation of OPG secretion using IL-1b or dexamethasone prior to TRAIL exposure resulted in decreased and increased rate of apoptosis, respectively ( P < 0.05). Thus, OPG secretion by breast cancer cells is modulated by cytokines and dexamethasone, and may represent a critical resistance mechanism that protects against TRAIL-induced apoptosis
Prediction of glycaemic control and quality of life in people with type 2 diabetes using glucose-lowering drugs with machine learning-The Maastricht study
Background Despite the heterogeneity of type 2 diabetes (T2D), all patients are treated according to the same guideline. Some people have more difficulty reaching treatment goals (adequate glycaemic control) and maintaining quality of life (QoL). Therefore, a prediction model identifying who is unlikely to reach these goals within the next year would be useful to allow specific attention to these people.Aim To investigate if machine learning algorithms can predict which individuals are unlikely to reach glycaemic control and likely to deteriorate in QoL in 1 year.Methods We used data from The Maastricht Study, including 842 people with T2D and information on HbA1c values, and 964 people with T2D and information on QoL. We evaluated several machine learning algorithms with feature selection methods and hyperparameter tuning in fivefold cross-validation for the corresponding outcomes.Results The prediction of inadequate glycaemic control showed good performance. The support vector machine classifier performed best in terms of accuracy (0.76 (95% CI 0.71-0.79)), precision (0.79 (95% CI 0.71-0.83)) and area under the receiver operating characteristic curve (AUC-ROC) (0.85 (95% CI 0.80-0.89)). The multi-layer perceptron classifier performed best in terms of recall (0.72 (95% CI 0.64-0.79)) and F1-score (0.73 (95% CI 0.64-0.79)). The prediction of deterioration in QoL showed inadequate performance and did not seem feasible.Conclusion Prediction of glycaemic control after 1 year in T2D is feasible with good model performance. However, the prediction of deterioration in QoL remains a challenge and needs further work
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