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1.
Integrating classical biological control with other management techniques such as herbicide, fire, mechanical control, grazing, or plant competition, can be the most effective way to manage invasive weeds in natural areas and rangelands. Biological control agents can be protected from potential negative impacts of these weed control methods through untreated refugia or by applying the treatment at a time when the agent is not vulnerable. A literature review of experiments that integrated biological control with other management strategies from 1987 to 2017 yielded 39 terrestrial and 16 aquatic studies. The tactics most frequently integrated with biological control were herbicide applications and plant competition. Despite numerous examples of successful programs and calls for more widespread integration of biological control with other weed management strategies, there was no increase in the number of studies reported annually over time. Additional studies investigating the ecological and economic benefits of integrated weed management are needed.  相似文献   

2.
The opportunities and challenges for the study and control of parasitic diseases in the 21st century are both exciting and daunting. Based on the contributions from this field over the last part of the 20th century, we should expect new biologic concepts will continue to come from this discipline to enrich the general area of biomedical research. The general nature of such a broad category of infections is difficult to distill, but they often depend on well-orchestrated, complex life cycles and they often involve chronic, relatively well-balanced host/parasite relationships. Such characteristics force biological systems to their limits, and this may be why studies of these diseases have made fundamental contributions to molecular biology, cell biology and immunology. However, if these findings are to continue apace, parasitologists must capitalize on the new findings being generated though genomics, bioinformatics, proteomics, and genetic manipulations of both host and parasite. Furthermore, they must do so based on sound biological insights and the use of hypothesis-driven studies of these complex systems. A major challenge over the next century will be to capitalize on these new findings and translate them into successful, sustainable strategies for control, elimination and eradication of the parasitic diseases that pose major public health threats to the physical and cognitive development and health of so many people worldwide.  相似文献   

3.
Malaria is a major global health problem and is caused by the unicellular parasite Plasmodium. Plasmodial surface proteins have important roles in host cell invasion and are responsible for antigenic diversity in this organism. Knowledge of the three-dimensional structure of surface proteins can facilitate our understanding their biological function, and contribute to the development of therapeutic and vaccine strategies against malaria. Structural studies allow rational drug design when ligand- or receptor-binding sites are identified and characterized. Analysis of the three-dimensional distribution of protective antibody epitopes and polymorphic residues can facilitate vaccine candidate optimization. With this in mind, some Plasmodium surface-protein structures have determined by X-ray crystallography or nuclear magnetic resonance.  相似文献   

4.
Regressions of biological variables across species are rarely perfect. Usually, there are residual deviations from the estimated model relationship, and such deviations commonly show a pattern of phylogenetic correlations indicating that they have biological causes. We discuss the origins and effects of phylogenetically correlated biological variation in regression studies. In particular, we discuss the interplay of biological deviations with deviations due to observational or measurement errors, which are also important in comparative studies based on estimated species means. We show how bias in estimated evolutionary regressions can arise from several sources, including phylogenetic inertia and either observational or biological error in the predictor variables. We show how all these biases can be estimated and corrected for in the presence of phylogenetic correlations. We present general formulas for incorporating measurement error in linear models with correlated data. We also show how alternative regression models, such as major axis and reduced major axis regression, which are often recommended when there is error in predictor variables, are strongly biased when there is biological variation in any part of the model. We argue that such methods should never be used to estimate evolutionary or allometric regression slopes.  相似文献   

5.
Vascularization is a key process in skin tissue engineering, determining the biological function of artificial skin implants. Hence, efficient vascularization strategies are a major prerequisite for the safe application of these implants in clinical practice. Current approaches include (i) modification of structural and physicochemical properties of dermal scaffolds, (ii) biological scaffold activation with growth factor-releasing systems or gene vectors, and (iii) generation of prevascularized skin substitutes by seeding scaffolds with vessel-forming cells. These conventional approaches may be further supplemented by emerging strategies, such as transplantation of adipose tissue-derived microvascular fragments, 3D bioprinting and microfluidics, miRNA modulation, cell sheet engineering, and fabrication of photosynthetic scaffolds. The successful translation of these vascularization strategies from bench to bedside may pave the way for a broad clinical implementation of skin tissue engineering.  相似文献   

6.
Protein phosphorylation constitutes a major type of post-translational modification that mobilizes a high number of genes, especially in plants, is involved in many crucial cell functions and largely participates to the complexity of the proteomes. For several biological and technical reasons, the characterization of phosphorylation sites requires complex procedures. In this review, the different approaches presently available to select phosphoproteins and phosphopeptides are described. A special emphasis is then given to the numerous strategies that have emerged for the analysis of phosphorylation sites by various techniques of mass spectrometry. Finally, the few attempts proposed for the quantification of phosphorylation events are presented. In another part, the results of the efforts made in the plant area to analyze the phosphoproteome are compared to those in other biological systems. These overviews are put together to delineate, according to the objectives pursued, the different strategies possible and the corresponding challenges.  相似文献   

7.
Pedro Barbosa 《Oecologia》1977,29(4):311-327
Summary The investigations of the bionomics and parasitoid-host interactions of some gypsy moth parasitoids provide an opportunity to consider the role of r and K strategies in the life history of some tachinid and hymenopterous parasitoid species. Available historic data as well as results of recent studies are utilized in an attempt to evaluate the degree to which the data conform to this paradigm. Few studies have provided the information required to evaluate this concept particularly in a parasitoid complex. The concept of r and K also is discussed in relation to biological control strategies, and the implications of this analysis for those arguments are discussed.This paper, No. 2059 (Massachusetts Agricultural Experiment Station) is made possible from research supported (in part) from Experiment Station Project No. 355  相似文献   

8.
Cannabis has been shown to be beneficial in the treatment of pain and inflammatory diseases. The biological effect of cannabis is mainly attributed to two major cannabinoids, tetrahydrocannabinol and cannabidiol. In the majority of studies to-date, a purified tetrahydrocannabinol and cannabidiol alone or in combination have been extensively examined in many studies for the treatment of numerous disorders including pain and inflammation. However, few studies have investigated the biological benefits of full-spectrum cannabis plant extract. Given that cannabis is known to generate a large number of cannabinoids along with numerous other biologically relevant products including terpenes, studies involving purified tetrahydrocannabinol and/or cannabidiol do not consider the potential biological benefits of the full-spectrum cannabis extracts. This may be especially true in the case of cannabis as a potential treatment of pain and inflammation. Herein, we review the pre-clinical physiological and molecular mechanisms in biological systems that are affected by cannabis.  相似文献   

9.
Obesity is widely recognized as a major global health problem caused by a chronic energy imbalance resulting from a combination of excess caloric intake and insufficient energy expenditure. Excessive energy intake and physical inactivity are traditional risk factors for obesity. Obesity is a risk factor for many diseases, including hypertension, diabetes and tumours. Recent studies have found a strong link between ferroptosis and obesity. Ferroptosis is an iron-dependent regulated cell death caused by iron overload and reactive oxygen species-dependent excessive accumulation of lipid peroxidation. Ferroptosis is involved in many biological processes, such as amino acid metabolism, iron metabolism and lipid metabolism. Some potential strategies to reduce the adverse effects of ferroptosis on obesity are suggested and future research priorities are highlighted.  相似文献   

10.
In mammals, the major component in energy production is molecular oxygen. This has led to the development of several elaborate strategies that tightly regulate oxygen homeostasis in order to allow appropriate cell function and survival. However, a sustained drop in oxygen supply to neuronal tissue has detrimental consequences to cell functioning and survival. Disturbances in oxygen supply have been implicated in a number of CNS disorders that can be related to hypoxia or ischemia. On a cellular level, oxygen-deprived stress induces a multitude of spatially and temporally regulated responses, ranging from adapted channel activity to altered gene expression. Global analysis of expression changes over several time points and tissue regions or cells has already shed light on previous known and unknown biological processes and molecules. By combining knowledge from several different expression-profiling studies into one database, the first steps are made in unifying and categorizing the molecular response to oxygen-deprived conditions, such as stroke. In this review, some of the queries that can be extracted from the database are discussed in regard to the biological context.  相似文献   

11.
The fundamental role of glycoconjugates in many biological processes is now well appreciated and has intensified the development of innovative and improved synthetic strategies. All areas of synthetic methodology have seen major advances and many complex, highly branched carbohydrates and glycoproteins have been prepared using solution- and/or solid-phase approaches. The development of an automated oligosaccharide synthesizer provides rapid access to biologically relevant compounds. These chemical approaches help to produce sufficient quantities of defined oligosaccharides for biological studies. Synthetic chemistry also supports an improved understanding of glycobiology and will eventually result in the discovery of new therapeutics.  相似文献   

12.
13.
In mammals, the major component in energy production is molecular oxygen. This has led to the development of several elaborate strategies that tightly regulate oxygen homeostasis in order to allow appropriate cell function and survival. However, a sustained drop in oxygen supply to neuronal tissue has detrimental consequences to cell functioning and survival. Disturbances in oxygen supply have been implicated in a number of CNS disorders that can be related to hypoxia or ischemia. On a cellular level, oxygen-deprived stress induces a multitude of spatially and temporally regulated responses, ranging from adapted channel activity to altered gene expression. Global analysis of expression changes over several time points and tissue regions or cells has already shed light on previous known and unknown biological processes and molecules. By combining knowledge from several different expression-profiling studies into one database, the first steps are made in unifying and categorizing the molecular response to oxygen-deprived conditions, such as stroke. In this review, some of the queries that can be extracted from the database are discussed in regard to the biological context.  相似文献   

14.
Brassicas are major vegetable crops in China but the systems for growing the crops are complex. During the last 30 years, the area of vegetable crops has increased steadily, however, the control of insect pests on brassica vegetables has largely relied on the heavy use of chemical insecticides, resulting in high levels of resistance, insecticide residues hazardous to human health and other serious consequences. Nevertheless, efforts to develop practical and sustainable integrated pest management (IPM) strategies for brassica vegetables have been implemented. Here we first review the work on surveys of natural enemies of insect pests in brassicas and describe the biology and ecology of a few important parasitoids. We then introduce the progress of conservation biological control by reviewing studies on evaluation of natural enemies and selective insecticides, the work on the development of action thresholds and some successful examples of IPM field trials at the cropping system level. The successful examples of IPM practices in brassicas show the great potential of conservation biological control to reduce chemical pesticide input and improve vegetable production in the future.  相似文献   

15.
BACKGROUND: The present review is based on the identification of four major environmental crises that have been approached from a biological oceanographic viewpoint. These crises are the release of contaminants in near shore marine waters, the collapse of marine resources that were renewable until recently, the loss of biodiversity, and global climate change METHODS: The review examines the contribution of cytometry-based biological oceanography to the resolution of the four environmental crises. Using a database of 302 papers, flow cytometric (FCM) studies in biological oceanography over the 1989--1999 decade are examined. Future biological oceanographic applications of FCM are discussed. RESULTS: Most of the published FCM oceanographic studies focus on phytoplankton and bacterioplankton. Analysis of our 1989-1999 database shows the predominance of studies dedicated to phytoplankton (77%), followed by heterotrophic bacteria (21%). The latter progressively increased over the last decade, together with the improved understanding of the biogeochemical and trophic roles of marine bacteria. Most studies on these two microorganisms were conducted in vitro until 1996, after which the trend reversed in favor of in situ research. The most investigated areas were those with major international sampling efforts, related to the changing climate. Concerning environmental topics, 62% of papers on phytoplankton and bacterioplankton focused on the structure of microbial communities and fluxes (e.g., production, grazing); this provides the basis for biological oceanographic studies on resources and climate change. CONCLUSIONS: Future progress in the biological oceanographic use of FCM will likely fall into two categories, i.e., applications where FCM will be combined with the development of other methods and those where FCM will be the main analytical tool. It is expected that FCM and other cytometric approaches will improve the ability of biological oceanography to address the major environmental challenges that are confronting human societies.  相似文献   

16.
Understanding the relationship between the amino‐acid sequence of a protein and its ability to fold and to function is one of the major challenges of protein science. Here, cases are reviewed in which mutagenesis, biochemistry, structure determination, protein engineering, and single‐molecule biophysics have illuminated the sequence determinants of folding, binding specificity, and biological function for DNA‐binding proteins and ATP‐fueled machines that forcibly unfold native proteins as a prelude to degradation. In addition to structure‐function relationships, these studies provide information about folding intermediates, mutations that accelerate folding, slow unfolding, and stabilize proteins against denaturation, show how new binding specificities and folds can evolve, and reveal strategies that proteolytic machines use to recognize, unfold, and degrade thousands of distinct substrates.  相似文献   

17.
The emergence of shotgun proteomics has facilitated the numerous biological discoveries made by proteomic studies. However, comprehensive proteomic analysis remains challenging and shotgun proteomics is a continually changing field. This review details the recent developments in shotgun proteomics and describes emerging technologies that will influence shotgun proteomics going forward. In addition, proteomic studies of integral membrane proteins remain challenging due to the hydrophobic nature in integral membrane proteins and their general low abundance levels. However, there have been many strategies developed for enriching, isolating and separating membrane proteins for proteomic analysis that have moved this field forward. In summary, while shotgun proteomics is a widely used and mature technology, the continued pace of improvements in mass spectrometry and proteomic technology and methods indicate that future studies will have an even greater impact on biological discovery.  相似文献   

18.
The application of mass spectrometry to identify disease biomarkers in clinical fluids like serum using high throughput protein expression profiling continues to evolve as technology development, clinical study design, and bioinformatics improve. Previous protein expression profiling studies have offered needed insight into issues of technical reproducibility, instrument calibration, sample preparation, study design, and supervised bioinformatic data analysis. In this overview, new strategies to increase the utility of protein expression profiling for clinical biomarker assay development are discussed with an emphasis on utilizing differential lectin-based glycoprotein capture and targeted immunoassays. The carbohydrate binding specificities of different lectins offer a biological affinity approach that complements existing mass spectrometer capabilities and retains automated throughput options. Specific examples using serum samples from prostate cancer and hepatocellular carcinoma subjects are provided along with suggested experimental strategies for integration of lectin-based methods into clinical fluid expression profiling strategies. Our example workflow incorporates the necessity of early validation in biomarker discovery using an immunoaffinity-based targeted analytical approach that integrates well with upstream discovery technologies.  相似文献   

19.
20.
This study analyzes trends in the extent of major floods in the lower reach of Songkhram River Basin, one of the most important areas for aquatic biological production in the Lower Mekong River Basin. We first classified the time series Landsat imagery acquired at a 2-year interval between 2000 and 2006 using the unsupervised classification method. We then analyzed the extent of major floods through the image matrix analysis on seasonal land cover map pairs. Additionally, we estimated flood volumes and discharge rates for each time series. We finally analyzed the extent of land uses that were affected by major flood events. Accuracy assessment showed that the extent of major floods was accurately mapped. Analysis of trends of major floods revealed that there was a considerable variation in the extent through 2006, with the flood decreasing since 2002. Analysis of flood risk areas based on the 2000–2004 data showed that about 3.04% of the study areas was at high risk of being flooded. Between 2000 and 2006, about 5.5% of the study area that are classified as agriculture and built-up land uses was affected by major floods. Our estimates on flood volumes and discharge rates are consistent with the data from other studies. Overall findings suggest that accurate mapping of major floods and flood risk areas using space and time dependent data can be important for developing protocols for flash flood early warning and flood risk management and mitigation. Output GIS maps and data combined with crude assumptions about water flow will serve as the baseline data to estimate the amount of water that flows in and out of the basin. Further research should focus on integration of social science research to evaluate the socio-economic impacts of major floods and identifying coping strategies of affected communities.  相似文献   

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