共查询到20条相似文献，搜索用时 0 毫秒
1.
Abdullgaffar B 《Cytopathology》2012,23(5):320-324
B. AbdullGaffar Impact factor in cytopathology journals: what does it reflect and how much does it matter? Objective: To study the trends of impact factor (IF) in four cytopathology journals. To investigate the factors that might influence IF in cytopathology literature and whether IF has any impact on cytopathology practice. Methods: The IFs of four cytopathology journals were searched from 2005 to 2009. The IFs and their relationships with the types and number of publications, publishers, the official societies, readership, the quality of their contents, the topics covered and the levels of evidence were compared. Results: Cancer Cytopathology (CC) had the highest IF. Acta Cytologica (AC) had the lowest IF, which appeared to be in decline. Cytopathology (C) and Diagnostic Cytopathology (DC) had a slow but steady increase in their IF. Components that might influence these differences could include the category and the society of the journal, targeted readers and certain types of publications. Publishers, the number of publications, the types of topics covered and the levels of evidence probably have no major effect on IF. Conclusions: IF has its own benefits and original applications. IF is a quantitative measure that does not reflect the levels of evidence in cytopathology journals. IF should not be abandoned because it might encourage competition between cytopathology journals, but it should not dictate their contents. 相似文献
2.
为了使科技论文摘要写作进一步规范化、标准化, 以期提高科技论文的质量, 针对植物学论文摘要中存在的一些问题, 就其内容、结构、写作格式等进行了分析, 论述了科技论文摘要规范化与标准化写作的重要意义, 并就如何加强科技论文摘要规范化写作以及科技期刊编辑的标准化意识进行了探讨。 相似文献
3.
4.
5.
6.
7.
8.
Abstract: Large herbivores such as elephants (Loxodonta africana) apparently have a negative impact on woody vegetation at moderate to high population densities. The confounding effects that fire, drought, and management history have may complicate assignment of such impacts to herbivory. We reviewed 238 studies published over 45 years and conducted a meta-analysis based on 21 studies that provided sufficient information on response of woody vegetation to elephants. We considered size and duration of studies, elephant densities, rainfall, fences, and study outcomes in our analysis. We detected a disproportionate citation of 20 published studies in our database, 15 of which concluded that woody vegetation responded negatively to elephants. Our analysis showed that high elephant densities had a negative effect on woody vegetation but that rainfall and presence of fences influenced these effects. In arid savannas, woody vegetation always responded negatively to elephants. In transitional savannas, an increase in elephant densities did not influence woody vegetation response. In mesic savannas, negative responses of woody vegetation increased when elephants occurred at higher densities, whereas elephants confined by fences also had more negative effects on woody plants than elephants that were not confined. Our analysis suggested that rainfall and fences influenced elephant density related impact and that research results were often site-specific. Local environmental conditions and site-specific objectives should be considered when developing management actions to curb elephant impacts on woody vegetation. 相似文献
9.
Flor Lacanilao 《Environmental Biology of Fishes》1997,49(1):01-05
Frequent gatherings, such as those on coastal management, have resulted in increased production of gray literature like conference proceedings and institutional reports, which are published without adequate peer review. In developing countries like those in southeast Asia, manuals and other publications used in workshops and training programs seldom use peer-reviewed references. Among papers sampled, those in conference proceedings have lower percentages of citations to peer-reviewed journals, whether or not the proceedings are issued as books or journal supplements. From three proceedings and one institutional report with a total of 37 papers and an average of 22 cited references per paper, citations to gray literature averaged 92 percent of total citations. This poor quality of the reference lists decrease the credibility of a paper. Scientific conferences should be designed to reverse the production and use of gray literature by limiting the scope of the proceedings to invited reviews, with other presentations appearing only as abstracts to encourage their ultimate publication in peer-reviewed journals. A conference book of reviews by respected scientists will then support incorporation of scientific information into policy and management decisions for more effective coastal management. 相似文献
10.
Abstract Pollen and plant macrofossil records from a selection of sites in Spain, France and Italy are used to explore the origin and the development of the Mediterranean vegetation. The role of evergreen and summergreen taxa is discussed. The expansion of sclerophyllous trees during the Pleistocene interglacials is well correlated with the orbital forcing. During the Holocene, the large number of data illustrates latitudinal and longitudinal differences in vegetation dynamics. Multidisciplinary studies identify short terms climatic fluctuations. The debate is still open between those who attribute an increase of sclerophyllous forests during the late Holocene to a trend toward aridity and those who consider this dynamic as human-induced. 相似文献
11.
《Animal : an international journal of animal bioscience》2019,13(1):198-208
Dairy production systems are often criticized as being major emitters of greenhouse gases (GHG). In this context, the extension of the length of the productive life of dairy cows is gaining interest as a potential GHG mitigation option. In the present study, we investigated cow and system GHG emission intensity and profitability based on data from 30 dairy cows of different productive lifetime fed either no or limited amounts of concentrate. Detailed information concerning productivity, feeding and individual enteric methane emissions of the individuals was available from a controlled experiment and herd book databases. A simplified GHG balance was calculated for each animal based on the milk produced at the time of the experiment and for their entire lifetime milk production. For the lifetime production, we also included the emissions arising from potential beef produced by fattening the offspring of the dairy cows. This accounted for the effect that changes in the length of productive life will affect the replacement rate and thus the number of calves that can be used for beef production. Profitability was assessed by calculating revenues and full economic costs for the cows in the data set. Both emission intensity and profitability were most favourable in cows with long productive life, whereas cows that had not finished their first lactation performed particularly unfavourably with regard to their emissions per unit of product and rearing costs were mostly not repaid. Including the potential beef production, GHG emissions in relation to total production of animal protein also decreased with age, but the overall variability was greater, as the individual cow history (lifetime milk yield, twin births, stillbirths, etc.) added further sources of variation. The present results show that increasing the length of productive life of dairy cows is a viable way to reduce the climate impact and to improve profitability of dairy production. 相似文献
12.
Emerging evidence has shown that leukocyte telomere length (LTL) is associated with various health-related outcomes, while the causality of these associations remains unclear. We performed a systematic review and meta-analysis of current evidence from Mendelian randomization (MR) studies on the association between LTL and health-related outcomes. We searched PubMed, Embase, and Web of Science up to April 2022 to identify eligible MR studies. We graded the evidence level of each MR association based on the results of the main analysis and four sensitive MR methods, MR-Egger, weighted median, MR-PRESSO, and multivariate MR. Meta-analyses of published MR studies were also performed. A total of 62 studies with 310 outcomes and 396 MR associations were included. Robust evidence level was observed for the association between longer LTL and increased risk of 24 neoplasms (the strongest magnitude for osteosarcoma, GBM, glioma, thyroid cancer, and non-GBM glioma), six genitourinary and digestive system outcomes of excessive or abnormal growth, hypertension, metabolic syndrome, multiple sclerosis, and clonal hematopoiesis of indeterminate potential. Robust inverse association was observed for coronary heart disease, chronic kidney disease, rheumatoid arthritis, juvenile idiopathic arthritis, idiopathic pulmonary fibrosis, and facial aging. Meta-analyses of MR studies suggested that genetically determined LTL was associated with 12 neoplasms and 9 nonneoplasm outcomes. Evidence from published MR studies supports that LTL plays a causal role in various neoplastic and nonneoplastic diseases. Further research is required to elucidate the underlying mechanisms and to bring insight into the potential prediction, prevention, and therapeutic applications of telomere length. 相似文献
13.
Negative changes in the scientific publication process in ecology: potential causes and consequences
1. Increasingly viewed to have societal impact and value, science is affected by complex changes such as globalisation and the increasing dominance of commercial interest. As a result, technical advancements, financial concerns, institutional prestige and journal proliferation have created challenges for ecological and other scientific journals and affected the perception of both researchers and the public about the science that they publish. 2. Journals are now used for more than dissemination of scientific research. Institutions use journal rankings for a variety of purposes and often require a pre‐established number of articles in hiring and budgetary decisions. Consequently, journal impact factors have achieved greater importance, and the splitting of articles into smaller parcels of information (‘salami‐slicing’) to increase numbers of publications has become more frequent. 3. Journals may prescribe upper limits to article length, even though the average length of articles for several ecological journals examined has increased over time. There are clear signs, however, that journals without length limits for articles will become rarer. In contrast to ecological journals, taxonomic journals are not following this trend. 4. Two case histories demonstrate how splitting longer ecological articles into a series of shorter ones results in both redundancy of information and actually increases the journal space used overall. Furthermore, with current rejection rates of ecological journals (often ～80%), many thin salami‐sliced articles jam the peer‐review system much longer (through resubmission after rejection) than unsliced articles previously did (e.g. when rejection rates were ～50%). In our experience, the increased pressure to publish many articles in ‘high‐impact’ journals also may decrease the attractiveness of a future scientific career in ecology to young people. 5. ‘Gatekeeping’ of journal quality has shifted from editors to reviewers, and several recent trends are apparent including: bias about appropriate statistical methods; reviewers being more rigid overall; non‐native English writers being criticised for poor communications skills; and favourable reviews being signed more often than unfavourable ones. In terms of production, outsourcing of copy editing has increased the final error rate of published material. 6. We supplemented our perceptions with those of older colleagues (～100 experienced ecologists) that responded to an informal survey on this topic (response rate: 81%). In the opinion of almost 90% of our respondents, the overall review process has changed and for 20% among them the professional quality of reviews has declined. 7. We, and many older colleagues, are convinced there have been some negative changes in the scientific publication process. If younger colleagues share this concern, we can collectively counter this deteriorating situation, because we are the key to the publishing and evaluation process. 相似文献
14.
Phytic acid has been identified by paper electrophoresis and NMR spectroscopy in extracts of pollen from Petunia hybrida. In this species pollen wa 相似文献
15.
Laura Sokka Suvi Lehtoranta Ari Nissinen Matti Melanen 《Journal of Industrial Ecology》2011,15(1):137-155
Studies of industrial symbiosis (IS) focus on the physical flows of materials and energy in local industrial systems. In an ideal IS, waste material and energy are shared or exchanged among the actors of the system, thereby reducing the consumption of virgin material and energy inputs, and likewise the generation of waste and emissions. In this study, the environmental impacts of an industrial ecosystem centered around a pulp and paper mill and operating as an IS are analyzed using life cycle assessment (LCA). The system is compared with two hypothetical reference systems in which the actors would operate in isolation. Moreover, the system is analyzed further in order to identify possibilities for additional links between the actors. The results show that of the total life cycle impacts of the system, upstream processes made the greatest overall contribution to the results. Comparison with stand‐alone production shows that in the case studied, the industrial symbiosis results in modest improvements, 5% to 20% in most impact categories, in the overall environmental impacts of the system. Most of the benefits occur upstream through heat and electricity production for the local town. All in all it is recommended that when the environmental impacts of industrial symbiosis are assessed, the impacts occurring upstream should also be studied, not only the impacts within the ecosystem. 相似文献
16.
Péter Batáry Kornélia Kurucz Marcela Suarez‐Rubio Dan E. Chamberlain 《Global Change Biology》2018,24(3):1046-1054
Urbanization is one of the most extreme forms of environmental alteration, posing a major threat to biodiversity. We studied the effects of urbanization on avian communities via a systematic review using hierarchical and categorical meta‐analyses. Altogether, we found 42 observations from 37 case studies for species richness and 23 observations from 20 case studies for abundance. Urbanization had an overall strong negative effect on bird species richness, whereas abundance increased marginally with urbanization. There was no evidence that city size played a role in influencing the relationship between urbanization and either species richness or abundance. Studies that examined long gradients (i.e. from urban to rural) were more likely to detect negative urbanization effects on species richness than studies that considered short gradients (i.e. urban vs. suburban or urban vs. rural areas). In contrast, we found little evidence that the effect of urbanization on abundance was influenced by gradient length. Effects of urbanization on species richness were more negative for studies including public green spaces (parks and other amenity areas) in the sampled landscapes. In contrast, studies performed solely in the urban matrix (i.e. no green spaces) revealed a strong positive effect on bird abundance. When performing subset analyses on urban–suburban, suburban–rural and suburban–natural comparisons, species richness decreased from natural to urban areas, but with a stronger decrease at the urban–suburban interface, whereas bird abundance showed a clear intermediate peak along the urban–rural gradient although abundance in natural areas was comparable to that in suburban areas. This suggests that species loss happens especially at the urban–suburban interface, and that the highest abundances occur in suburban areas compared to urban or rural areas. Thus, our study shows the importance of suburban areas, where the majority of birds occur with fairly high species richness. 相似文献
17.
Antoine M. Dujon Gail Schofield Georgina Bramwell Nynke Raven Rodrigo Hamede Frdric Thomas Beata Ujvari 《Evolutionary Applications》2020,13(7):1745-1755
Although transmissible cancers have, so far, only been documented in three independent animal groups, they not only impact animals that have high economic, environmental and social significance, but they are also one of the most virulent parasitic life forms. Currently known transmissible cancers traverse terrestrial and marine environments, and are predicted to be more widely distributed across animal groups; thus, the implementation of effective collaborative scientific networks is important for combating existing and emerging forms. Here, we quantify how collaborative effort on the three known transmissible cancers has advanced through the formation of collaborative networks among institutions and disciplines. These three cancers occur in bivalves (invertebrates—disseminated neoplasia; DN), Tasmanian devils (vertebrate—marsupial; devil facial tumour disease; DFTD) and dogs (vertebrate—eutherian mammal; canine transmissible venereal tumour; CTVT). Research on CTVT and DN has been conducted since 1876 and 1969, respectively, whereas systematic research on DFTD only started in 2006. Yet, collaborative effort on all three diseases is global, encompassing six major Scopus subject areas. Collaborations steadily increased between 1963 and 2006 for CTVT and DN, with similar acceleration for all three cancers since 2006. Network analyses demonstrated that scientists are organizing themselves into efficient collaborative networks; however, these networks appear to be far stronger for DFTD and DN, possibly due to the recent detection of new strains adding impetus to research and associated publications (enhancing citation trajectories). In particular, global and multidisciplinary collaborations formed almost immediately after DFTD research was initiated, leading to similar research effort and relatively greater research outputs compared to the other two diseases. Therefore, in the event of outbreaks of new lineages of existing transmissible cancers, or the discovery of new transmissible cancers in the future, the rapid formation of international collaborations spanning relevant disciplines is vital for the efficient management of these diseases. 相似文献
18.
Ryan M. Bright Kaiguang Zhao Robert B. Jackson Francesco Cherubini 《Global Change Biology》2015,21(9):3246-3266
By altering fluxes of heat, momentum, and moisture exchanges between the land surface and atmosphere, forestry and other land‐use activities affect climate. Although long recognized scientifically as being important, these so‐called biogeophysical forcings are rarely included in climate policies for forestry and other land management projects due to the many challenges associated with their quantification. Here, we review the scientific literature in the fields of atmospheric science and terrestrial ecology in light of three main objectives: (i) to elucidate the challenges associated with quantifying biogeophysical climate forcings connected to land use and land management, with a focus on the forestry sector; (ii) to identify and describe scientific approaches and/or metrics facilitating the quantification and interpretation of direct biogeophysical climate forcings; and (iii) to identify and recommend research priorities that can help overcome the challenges of their attribution to specific land‐use activities, bridging the knowledge gap between the climate modeling, forest ecology, and resource management communities. We find that ignoring surface biogeophysics may mislead climate mitigation policies, yet existing metrics are unlikely to be sufficient. Successful metrics ought to (i) include both radiative and nonradiative climate forcings; (ii) reconcile disparities between biogeophysical and biogeochemical forcings, and (iii) acknowledge trade‐offs between global and local climate benefits. We call for more coordinated research among terrestrial ecologists, resource managers, and coupled climate modelers to harmonize datasets, refine analytical techniques, and corroborate and validate metrics that are more amenable to analyses at the scale of an individual site or region. 相似文献
19.
Abbie S. A. Chapman Verena Tunnicliffe Amanda E. Bates 《Diversity & distributions》2018,24(5):568-578
Aim
Rare species typically contribute more to functional diversity than common species. However, humans have altered the occupancy and abundance patterns of many species—the basis upon which we define “rarity.” Here, we use a globally unique dataset from hydrothermal vents—an untouched ecosystem—to test whether rare species over‐contribute to functional diversity.Location
Juan de Fuca Ridge hydrothermal vent fields, Northeast Pacific Ocean.Methods
We first conduct a comprehensive review to set up expectations for the relative contributions of rare and common species to functional diversity. We then quantify the rarity and commonness of 37 vent species with relevant trait information to assess the relationship between rarity and functional distinctiveness—a measure of the uniqueness of the traits of a species relative to traits of coexisting species. Next, we randomly assemble communities to test whether rare species over‐contribute to functional diversity in artificial assemblages ranging in species richness. Then, we test whether biotic interactions influence functional diversity contributions by comparing the observed contribution of each species to a null expectation. Finally, we identify traits driving functional distinctiveness using a distance‐based redundancy analysis.Results
Across functional diversity metrics and species richness levels, we find that both rare and common species can contribute functional uniqueness. Some species always offer unique trait combinations, and these species host bacterial symbionts and provide habitat complexity. Moreover, we find that contributions of species to functional diversity may be influenced by biotic interactions.Main conclusions
Our findings show that many common species make persistent, unique contributions to functional diversity. Thus, it is key to consider whether the abundance and occupancy of species have been reduced, relative to historical baselines, when interpreting the contributions of rare species to functional diversity. Our work highlights the importance of testing ecological theory in ecosystems unaffected by human activities for the conservation of biodiversity. 相似文献20.
Franζoise Stoll-Keller 《中国病毒学》2008,23(2)
Hepatitis C virus (HCV) is a member of the Flaviviridae family and causes acute and chronic hepatitis. Chronic HCV infection may result in severe liver damage including liver cirrhosis and hepatocellular carcinoma. The liver is the primary target organ of HCV, and the hepatocyte is its primary target cell. Attachment of the virus to the cell surface followed by viral entry is the first step in a cascade of interactions between the virus and the target cell that is required for successful entry into the cell and initiation of infection. This step is an important determinant of tissue tropism and pathogenesis; it thus represents a major target for antiviral host cell responses, such as antibody-mediated virus neutralization. Following the development of novel cell culture models for HCV infection our understanding of the HCV entry process and mechanisms of virus neutralization has been markedly advanced. In this review we summarize recent developments in the molecular biology of viral entry and its impact on pathogenesis of HCV infection, development of novel preventive and therapeutic antiviral strategies. 相似文献