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1.
A decline in mitochondrial function occurs in many conditions. A report in this issue of Cell Metabolism (Larsen et al., 2011) shows that dietary inorganic nitrates enhance muscle mitochondrial efficiency. It is an attractive hypothesis that dietary changes enhance energy efficiency, but its potential application depends on long-term studies investigating net benefits versus adverse effects.  相似文献   

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Twenty-five bacterial species were cultured in basal broth plus 1 of 19 different carbohydrates which were sterilized by Seitz filtration, autoclaving (112 C, 10 min), or exposure to 0.2% β-propiolactone (BPL). No significant differences were found either in the visual observations for acid and gas, pH, or titrable acidity determinations after 3 days of incubation with any of the three preparations tested. An effort was made to further determine the effect of BPL and heat on carbohydrates by assaying for glucose before and after treatment. Results indicated that glucose was not degraded by 0.2% BPL, however, it was shown that autoclave temperatures caused extensive degradation. Statistical treatment of the results from Warburg studies indicated that BPL-treated glucose showed no appreciable toxic effects, although the actual oxygen uptake was not as great as with Seitz- or autoclave-treated glucose. The application of the BPL sterilization process was discussed.  相似文献   

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Blinding protects against bias but the success of blinding is seldom assessed and reported in clinical trials including studies of acupuncture where blinding represents a major challenge. Recently, needles with the potential for double-blinding were developed, so we tested if acupuncture can be double-blinded in a randomized study of sixty-seven patients with acute pain ≥ 3 (0-10 scale following third molar removal) who received active acupuncture with a penetrating needle or placebo acupuncture with a non-penetrating needle. To test if acupuncture was administered double-blind, patients and acupuncturists were asked about perceived treatment allocation at the end of the study. To test if there were clues which led to identification of the treatment, deep dull pain associated with needle application and rotation (termed “de qi” in East Asian medicine), and patients’ pain levels were assessed. Perceived treatment allocation depended on actual group allocation (p < 0.015) for both patients and acupuncturists, indicating that the needles were not successful in double-blinding. Up to 68% of patients and 83% of acupuncturists correctly identified the treatment, but for patients the distribution was not far from 50/50. Also, there was a significant interaction between actual or perceived treatment and the experience of de qi (p = 0.027), suggesting that the experience of de qi and possible non-verbal clues contributed to correct identification of the treatment. Yet, of the patients who perceived the treatment as active or placebo, 50% and 23%, respectively, reported de qi. Patients’ acute pain levels did not influence the perceived treatment. In conclusion, acupuncture treatment was not fully double-blinded which is similar to observations in pharmacological studies. Still, the non-penetrating needle is the only needle that allows some degree of practitioner blinding. The study raises questions about alternatives to double-blind randomized clinical trials in the assessment of acupuncture treatment.  相似文献   

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Spatial autocorrelation (SAC) is often observed in species distribution data, and can be caused by exogenous, autocorrelated factors determining species distribution, or by endogenous population processes determining clustering such as dispersal. However, it remains debated whether SAC patterns can actually reveal endogenous processes. We reviewed studies measuring dispersal of the salamander Salamandra salamandra, to formulate a priori hypotheses on the scale at which dispersal is expected to determine population distribution. We then tested the hypotheses by analysing SAC in distribution data, and evaluating whether controlling for the effect of environmental variables can reveal endogenous processes. We surveyed 565 streams to obtain species distribution data; we also recorded landscape and microhabitat features known to affect the species. We used multiple approaches to tease apart endogenous and exogenous SAC: the analysis of residuals of logistic regression models considering different environmental variables; the analysis of eigenvectors extracted by several implementations of spatial eigenvector mapping. In capture–mark–recapture studies, 98% of individuals moved 500 m or less. Both species distribution and environmental features were strongly autocorrelated. The residuals of logistic regression relating species to environmental variables were autocorrelated at distances up to 500 m; analyses considering different sets of environmental variables, or assuming non‐linear species habitat relationships, yielded identical results. The results of spatial eigenvector mapping strongly depended on the matrix of distances used. Nevertheless, the eigenvectors of models with best fit were autocorrelated at distances up to 200–500 m. The concordance between multiple approaches suggests that 500 m is the scale at which dispersal connects breeding localities, increasing probability of occurrence. If exogenous variables are correctly identified, the analysis of SAC can provide important insights on endogenous population processes, such as the flow of individuals. SAC analysis can also provide important information for conservation, as the existence of metapopulations or population networks is essential for long term persistence of amphibians.  相似文献   

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The placebo effect is an interesting phenomenon whereby a dummy treatment can produce therapeutic benefit, such as, pain relief. While evidence for the placebo effect is growing, relatively few studies have explored ways of enhancing placebo effects. To address this, the current study tested whether placebo-induced analgesia could be enhanced by providing an educational handout about the efficacy of analgesics. Fifty university students were allocated to receive placebo treatment under the guise of a new analgesic formula, either with or without an educational handout, or to a no treatment control group before undergoing electrical and cold pressor pain tests. There was a placebo effect for electrically-induced pain with those receiving placebo treatment reporting significantly less pain compared with those who received no treatment. There was also some evidence of enhancement of this placebo-induced analgesia for electrically-induced pain as a result of the educational handout. No differences were found on cold pressor-induced pain. These findings suggest that providing educational information about a treatment could enhance its efficacy via the placebo effect. Future studies should test different methods of providing educational information in order to determine which elicit the strongest effects.  相似文献   

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Malnutrition, poor health, hunger, and even starvation are still the world's greatest challenges. Malnutrition is defined as deficiency of nutrition due to not ingesting the proper amounts of nutrients by simply not eating enough food and/or by consuming nutrient-poor food in respect to the daily nutritional requirements. Moreover, malnutrition and disease are closely associated and incidences of such diet-related diseases increase particularly in low- and middle-income states. While foods of animal origin are often unaffordable to low-income families, various neglected crops can offer an alternative source of micronutrients, vitamins, as well as health-promoting secondary plant metabolites. Therefore, agricultural and horticultural research should develop strategies not only to produce more food, but also to improve access to more nutritious food. In this context, one promising approach is to promote biodiversity in the dietary pattern of low-income people by getting access to nutritional as well as affordable food and providing recommendations for food selection and preparation. Worldwide, a multitude of various plant species are assigned to be consumed as grains, vegetables, and fruits, but only a limited number of these species are used as commercial cash crops. Consequently, numerous neglected and underutilized species offer the potential to diversify not only the human diet, but also increase food production levels, and, thus, enable more sustainable and resilient agro- and horti-food systems. To exploit the potential of neglected plant (NP) species, coordinated approaches on the local, regional, and international level have to be integrated that consequently demand the involvement of numerous multi-stakeholders. Thus, the objective of the present review is to evaluate whether NP species are important as “Future Food” for improving the nutritional status of humans as well as increasing resilience of agro- and horti-food systems.  相似文献   

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Nine healthy children took part in five sessions of feedback and instrumental conditioning of slow cortical potentials (SCPs). The feedback conditions (the relation between the feedback signal and amplitude of SCP) were inverted after two sessions. Neither the children nor the therapists were aware of this change. The adjustment of the children to the new feedback setting and the self-regulation strategies employed were investigated. The results were as follows: (a) Healthy children achieved control over cortical negativity within two sessions. (b) The change of feedback conditions worsened the regulation abilities, which then improved again within the following three sessions. (c) After the first two sessions, the participants were able to describe strategies that were successful during different phases of self-regulation. (d) Following the change in the feedback conditions, the children re-evaluated the way they influenced their SCPs. However, they did not alter the cognitive or behavioral strategies. The study demonstrated that positive and negative reinforcement and the knowledge of results are more important for successful self-regulation than the search for effective strategies. The relevance of these findings is discussed.  相似文献   

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Low efficiency is a key problem confronting the development and application of phytoremediation technology. Based on political pressure to reduce CO2 emissions in China and the fact that CO2 is necessary for plant photosynthesis, the effects of captured CO2 fertilization on phytoremediation of soil di-(2-ethylhexyl) phthalate (DEHP) pollution by C3 plant (mung bean, Vigna radiata L.) and C4 plant (maize, Zea mays L.) were investigated. Results showed that DEHP pollution negatively affected the growth and rhizosphere environments of both plants. After CO2 fertilization, both plants had more biomass (aboveground, belowground, and total dry weight), higher alkaline phosphatase activity, and more microbes with DEHP tolerance in their rhizospheres. Superoxide dismutase activity in leaves of both plants decreased significantly. Microbial community composition in both rhizospheres changed. CO2 fertilization also increased plant uptake of DEHP, particularly in the roots, and decreased residual DEHP concentrations in the rhizospheres. These effects were more evident in the C3 than in the C4 plant. This study indicated that CO2 fertilization can enhance the phytoremediation process of polluted soil through promoting plant growth, improving the rhizosphere environment, and increasing plant uptake of DEHP, particular in a C3 plant. CO2 fertilization could be considered as a measure to enhance phytoremediation.  相似文献   

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The notion that sequence homology implies functional similarity underlies much of computational biology. In the case of protein-protein interactions, an interaction can be inferred between two proteins on the basis that sequence-similar proteins have been observed to interact. The use of transferred interactions is common, but the legitimacy of such inferred interactions is not clear. Here we investigate transferred interactions and whether data incompleteness explains the lack of evidence found for them. Using definitions of homology associated with functional annotation transfer, we estimate that conservation rates of interactions are low even after taking interactome incompleteness into account. For example, at a blastp -value threshold of , we estimate the conservation rate to be about between S. cerevisiae and H. sapiens. Our method also produces estimates of interactome sizes (which are similar to those previously proposed). Using our estimates of interaction conservation we estimate the rate at which protein-protein interactions are lost across species. To our knowledge, this is the first such study based on large-scale data. Previous work has suggested that interactions transferred within species are more reliable than interactions transferred across species. By controlling for factors that are specific to within-species interaction prediction, we propose that the transfer of interactions within species might be less reliable than transfers between species. Protein-protein interactions appear to be very rarely conserved unless very high sequence similarity is observed. Consequently, inferred interactions should be used with care.  相似文献   

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ABSTRACT

Animal welfare concerns have plagued the professional zoo and aquarium field for decades. Societal differences remain concerning the well-being of animals, but it appears a shift is emerging. Scientific studies of animal welfare have dramatically increased, establishing that many previous concerns were not misguided public empathy or anthropomorphism. As a result, both zoo and aquarium animal welfare policy and science are now at the center of attention within the world’s professional zoos and aquariums. It is now possible to view a future that embraces the well-being of individual captive exotic animals, as well as that of their species, and one in which professional zoos and aquariums are dedicated equally to advancing both. Though the ethics of keeping exotic animals and animals from the wild in captivity are still a contentious subject both outside and even within the profession, this study argues. We argue that this path forward will substantially improve most zoo and aquarium animals' welfare and could significantly reduce societal concerns. If animal welfare science and policy are strongly rooted in compassion and embedded in robust accreditation systems, the basic zoo/aquarium paradigm will move toward a more thoughtful approach to the interface between visitors and animals. It starts with a fundamental commitment to the welfare of individual animals.  相似文献   

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Summary Reduced activity of -glucosidase was shown in the cultured skin fibroblasts of four patients with I-cell disease when the enzyme was tested without the use of detergents. In the presence of taurocholate and triton X100 -glucosidase activity was normal. This suggested a deficiency of a -glucosidase-activating factor in I-cell fibroblasts rather than of the enzyme itself. The deficiency of -glucosidase activity was corrected to some extent by mixing cell lysates, and more effectively by cocultivation and fusion of I-cell disease and Gaucher fibroblasts. These results present evidence for the presence of a -glucosidase-activating factor in normal and Gaucher fibroblasts. In fibroblasts of patients with I-cell disease this activator is probably deficient, as is the case for most lysosomal enzymes.  相似文献   

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Optimal nutrition is critical for human development and economic growth. Sub-Saharan Africa is facing high levels of food insecurity and only few sub-Saharan African countries are on track to eradicate extreme poverty and hunger by 2015. Effective research capacity is crucial for addressing emerging challenges and designing appropriate mitigation strategies in sub-Saharan Africa. A clear understanding of the operating environment for nutrition research in sub-Saharan Africa is a much needed prerequisite. We collected data on the barriers and requirements for conducting nutrition research in sub-Saharan Africa through semi-structured interviews with 144 participants involved in nutrition research in 35 countries in sub-Saharan Africa. A total of 133 interviews were retained for coding. The main barriers identified for effective nutrition research were the lack of funding due to poor recognition by policymakers of the importance of nutrition research and under-utilisation of research findings for developing policy, as well as an absence of research priority setting from within Africa. Current research topics were perceived to be mainly determined by funding bodies from outside Africa. Nutrition researchers argued for more commitment from policymakers at national level. The low capacity for nutrition research was mainly seen as a consequence of insufficient numbers of nutrition researchers, limited skills and a poor research infrastructure. In conclusion, African nutrition researchers argued how research priorities need to be identified by African stakeholders, accompanied by consensus building to enable creating a problem-driven national research agenda. In addition, it was considered necessary to promote interactions among researchers, and between researchers and policymakers. Multidisciplinary research and international and cross-African collaboration were seen as crucial to build capacity in sub-Saharan nutrition research.  相似文献   

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