The Carbon_h-factor: predicting individuals' research impact at early stages of their career

Assessing an individual's research impact on the basis of a transparent algorithm is an important task for evaluation and comparison purposes. Besides simple but also inaccurate indices such as counting the mere number of publications or the accumulation of overall citations, and highly complex but also overwhelming full-range publication lists in their raw format, Hirsch (2005) introduced a single figure cleverly combining different approaches. The so-called h-index has undoubtedly become the standard in scientometrics of individuals' research impact (note: in the present paper I will always use the term "research impact" to describe the research performance as the logic of the paper is based on the h-index, which quantifies the specific "impact" of, e.g., researchers, but also because the genuine meaning of impact refers to quality as well). As the h-index reflects the number h of papers a researcher has published with at least h citations, the index is inherently positively biased towards senior level researchers. This might sometimes be problematic when predictive tools are needed for assessing young scientists' potential, especially when recruiting early career positions or equipping young scientists' labs. To be compatible with the standard h-index, the proposed index integrates the scientist's research age (Carbon_h-factor) into the h-index, thus reporting the average gain of h-index per year. Comprehensive calculations of the Carbon_h-factor were made for a broad variety of four research-disciplines (economics, neuroscience, physics and psychology) and for researchers performing on three high levels of research impact (substantial, outstanding and epochal) with ten researchers per category. For all research areas and output levels we obtained linear developments of the h-index demonstrating the validity of predicting one's later impact in terms of research impact already at an early stage of their career with the Carbon_h-factor being approx. 0.4, 0.8, and 1.5 for substantial, outstanding and epochal researchers, respectively.     

The Pagerank-Index: Going beyond Citation Counts in Quantifying Scientific Impact of Researchers

Quantifying and comparing the scientific output of researchers has become critical for governments, funding agencies and universities. Comparison by reputation and direct assessment of contributions to the field is no longer possible, as the number of scientists increases and traditional definitions about scientific fields become blurred. The h-index is often used for comparing scientists, but has several well-documented shortcomings. In this paper, we introduce a new index for measuring and comparing the publication records of scientists: the pagerank-index (symbolised as π). The index uses a version of pagerank algorithm and the citation networks of papers in its computation, and is fundamentally different from the existing variants of h-index because it considers not only the number of citations but also the actual impact of each citation. We adapt two approaches to demonstrate the utility of the new index. Firstly, we use a simulation model of a community of authors, whereby we create various ‘groups’ of authors which are different from each other in inherent publication habits, to show that the pagerank-index is fairer than the existing indices in three distinct scenarios: (i) when authors try to ‘massage’ their index by publishing papers in low-quality outlets primarily to self-cite other papers (ii) when authors collaborate in large groups in order to obtain more authorships (iii) when authors spend most of their time in producing genuine but low quality publications that would massage their index. Secondly, we undertake two real world case studies: (i) the evolving author community of quantum game theory, as defined by Google Scholar (ii) a snapshot of the high energy physics (HEP) theory research community in arXiv. In both case studies, we find that the list of top authors vary very significantly when h-index and pagerank-index are used for comparison. We show that in both cases, authors who have collaborated in large groups and/or published less impactful papers tend to be comparatively favoured by the h-index, whereas the pagerank-index highlights authors who have made a relatively small number of definitive contributions, or written papers which served to highlight the link between diverse disciplines, or typically worked in smaller groups. Thus, we argue that the pagerank-index is an inherently fairer and more nuanced metric to quantify the publication records of scientists compared to existing measures.     

The strike rate index: a new index for journal quality based on journal size and the h-index of citations

Quantifying the impact of scientific research is almost always controversial, and there is a need for a uniform method that can be applied across all fields. Increasingly, however, the quantification has been summed up in the impact factor of the journal in which the work is published, which is known to show differences between fields. Here the h-index, a way to summarize an individual's highly cited work, was calculated for journals over a twenty year time span and compared to the size of the journal in four fields, Agriculture, Condensed Matter Physics, Genetics and Heredity and Mathematical Physics. There is a linear log-log relationship between the h-index and the size of the journal: the larger the journal, the more likely it is to have a high h-index. The four fields cannot be separated from each other suggesting that this relationship applies to all fields. A strike rate index (SRI) based on the log relationship of the h-index and the size of the journal shows a similar distribution in the four fields, with similar thresholds for quality, allowing journals across diverse fields to be compared to each other. The SRI explains more than four times the variation in citation counts compared to the impact factor.     

Bounds and inequalities relating h-index, g-index, e-index and generalized impact factor: an improvement over existing models

In this paper, we describe some bounds and inequalities relating h-index, g-index, e-index, and generalized impact factor. We derive the bounds and inequalities relating these indexing parameters from their basic definitions and without assuming any continuous model to be followed by any of them. We verify the theorems using citation data for five Price Medalists. We observe that the lower bound for h-index given by Theorem 2, [formula: see text], g ≥ 1, comes out to be more accurate as compared to Schubert-Glanzel relation h is proportional to C(2/3)P(-1/3) for a proportionality constant of 1, where C is the number of citations and P is the number of papers referenced. Also, the values of h-index obtained using Theorem 2 outperform those obtained using Egghe-Liang-Rousseau power law model for the given citation data of Price Medalists. Further, we computed the values of upper bound on g-index given by Theorem 3, g ≤ (h + e), where e denotes the value of e-index. We observe that the upper bound on g-index given by Theorem 3 is reasonably tight for the given citation record of Price Medalists.     

Performance of MAX test and degree of dominance index in predicting the mode of inheritance

We evaluate power performance to detect the correct mode of inheritance in gene-disease associations of two different approaches: the MAX test and the degree of dominance index or h-index. The MAX test is a special case of the conditional independence tests that simultaneously test for association and select the most likely genetic model based on a three-dimensional normal distribution. The h-index is based on the philosophy of using orthogonal contrasts to infer the mode of inheritance quantitatively. A population genetic model is developed where the real mode of inheritance is known a priori and power performance can be accurately determined. The simulations showed that none of the two approaches generally outperforms the other, nor each of them provides a panacea to estimate efficiently the mode of inheritance in all parameter space. However, the simultaneous application of both approaches can provide insights in determining the underlying mode of inheritance.     

An Absolute Index (Ab-index) to Measure a Researcher’s Useful Contributions and Productivity

Bibliographic analysis has been a very powerful tool in evaluating the effective contributions of a researcher and determining his/her future research potential. The lack of an absolute quantification of the author’s scientific contributions by the existing measurement system hampers the decision-making process. In this paper, a new metric system, Absolute index (Ab-index), has been proposed that allows a more objective comparison of the contributions of a researcher. The Ab-index takes into account the impact of research findings while keeping in mind the physical and intellectual contributions of the author(s) in accomplishing the task. The Ab-index and h-index were calculated for 10 highly cited geneticists and molecular biologist and 10 young researchers of biological sciences and compared for their relationship to the researchers input as a primary author. This is the first report of a measuring method clarifying the contributions of the first author, corresponding author, and other co-authors and the sharing of credit in a logical ratio. A java application has been developed for the easy calculation of the Ab-index. It can be used as a yardstick for comparing the credibility of different scientists competing for the same resources while the Productivity index (Pr-index), which is the rate of change in the Ab-index per year, can be used for comparing scientists of different age groups. The Ab-index has clear advantage over other popular metric systems in comparing scientific credibility of young scientists. The sum of the Ab-indices earned by individual researchers of an institute per year can be referred to as Pr-index of the institute.     

Carbon footprint of science: More than flying

Previous efforts to evaluate the climate change impact of researchers have focused mainly on transport related impact of conference attendance, and infrastructure. Because these represent only a part of the activities involved in the science making process this short note presents the carbon footprint of a complete science making process of one specific case. Apart from presenting the total footprint, we evaluate the relative contribution of the different scientific activities, and quantify mitigating possibilities. The case PhD project had a carbon footprint of 21.5 t CO₂-eq (2.69 t CO₂-eq per peer-reviewed paper, 0.3 t CO₂-eq per citation and 5.4 t CO₂-eq per h-index unit at graduation) of which general mobility represents 75%. Conference attendance was responsible for 35% of the carbon footprint, whereas infrastructure related emissions showed to contribute 20% of the total impact. Videoconferencing could have reduced the climate change impact on this case PhD with up to 44%. Other emission reduction initiatives, such as using green electricity, reduction of energy consumption, and promoting commuting by bicycle, could have triggered a reduction of 14% in this case study. This note fits in the movement of academics and universities willing to be green. The study confirms that researchers’ mobility is the biggest contributor to his or her carbon footprint, but is not limited to conference attendance, showing the importance of considering all activities in the science making process.     

Talking about Climate Change and Global Warming

The increasing prevalence of social networks provides researchers greater opportunities to evaluate and assess changes in public opinion and public sentiment towards issues of social consequence. Using trend and sentiment analysis is one method whereby researchers can identify changes in public perception that can be used to enhance the development of a social consciousness towards a specific public interest. The following study assessed Relative search volume (RSV) patterns for global warming (GW) and Climate change (CC) to determine public knowledge and awareness of these terms. In conjunction with this, the researchers looked at the sentiment connected to these terms in social media networks. It was found that there was a relationship between the awareness of the information and the amount of publicity generated around the terminology. Furthermore, the primary driver for the increase in awareness was an increase in publicity in either a positive or a negative light. Sentiment analysis further confirmed that the primary emotive connections to the words were derived from the original context in which the word was framed. Thus having awareness or knowledge of a topic is strongly related to its public exposure in the media, and the emotional context of this relationship is dependent on the context in which the relationship was originally established. This has value in fields like conservation, law enforcement, or other fields where the practice can and often does have two very strong emotive responses based on the context of the problems being examined.     

Food habits of the longnose skate, <Emphasis Type="Italic">Raja rhina</Emphasis> (Jordan and Gilbert, 1880), in central California waters

Feeding studies can provide researchers with important insights towards understanding potential fishery impacts on marine systems. Raja rhina is one of the most common elasmobranch species landed in central and northern California demersal fisheries, yet life history information is extremely limited for this species and aspects of its diet are unknown. Specimens of R. rhina were collected between September, 2002 and August, 2003 from fisheries-independent trawl surveys. Percent Index of Relative Importance values indicated that the five most important prey items in 618 stomachs of R. rhina were unidentified teleosts (31.6% IRI), unidentified shrimps (19.6% IRI), unidentified euphausiids (10.9% IRI), Crangonidae (7.4% IRI), and Neocrangon resima (6.0% IRI). There were significant dietary shifts with increasing skate total length and with increasing depths. Smaller skates ate small crustaceans and larger skates ate larger fishes and cephalopods. With increasing depths, diet included bentho-pelagic teleosts and more cephalopods and euphausiids. The findings of this study are consistent with previous researchers that report similar diet shifts in skate species with size and depth.     

Curare - A Curative Poison: A Scientometric Analysis

Introduction

Curare is one of the best-examined neurotoxins of the world, which has empirically been used for centuries by American Indigenes. Research on curare has been performed much later, a global scientometric analysis on curare research or its derivates does not yet exist. This bibliometric analysis is part of the global NewQis-project and should illuminate both toxic and historic issues of research on curare.

Methods

The ISI Web of Science was searched for data covering 1900 to 2013 using a term which included as many original articles on curare as possible. 3,867 articles were found and analyzed for common bibliometric items such as the number of citations, language of the articles or the (modified) Hirsch-Index (h-index). Results are illustrated utilizing modern density equalizing map projections (DEMP) or beam diagrams.

Results

Most publications were located in North America and Europe. The USA has the highest number of publications as well as the highest h-index. The number of publications overall rose until the late 1990s and later decreased. Furthermore, sudden increases of research activity are ascribable to historic events, like the first use of curare as muscle relaxant during surgery.

Discussion

This scientometric analysis of curare research reflects several tendencies as previously seen in other bibliometric investigations, i.e. the scientific quality standard of North America and Europe. Research on curare decreased however, due to the declining attention towards this muscle relaxant. This work exemplifies also how scientometric methods can be used to illuminate historic circumstances immediately stimulating scientific research.     

全球北极底栖生物研究文献计量分析

以Thomson Reuters的Web of Science信息平台提供的SCI-E数据库为数据源,检索到从1991年至2012年期间全球北极底栖生物研究论文2127篇,利用Note Express软件,分析22年间论文发表的年度、国家、机构、作者、期刊和学科等方面的分布特征,结果表明:1)全球北极底栖生物研究论文数量、篇均作者数和篇均参考文献数都在逐年增加;2)研究论文涉及58个国家或地区,位于前7位的国家依次是美国、德国、加拿大、挪威、俄罗斯、英国和丹麦;美国、加拿大、挪威和丹麦是该领域国际合作研究最主要的国家;3)论文涉及1364个机构,前20名的研究机构中,美国有6家,德国、加拿大和挪威各有3家,俄罗斯和丹麦各有2家,波兰有1家。俄罗斯、丹麦、波兰、德国和挪威超过60%的研究力量集中在位列前20位的相关机构中。俄罗斯科学院论文总量排列首位,德国阿尔弗雷德魏格纳极地与海洋研究中心和基尔大学论文的h指数最高为32;4)论文涉及最多的4个学科是海洋与淡水生物学、生态学、海洋学和多学科地球科学。Polar Biology和Marine Ecology Progress Series是发表该领域最核心的期刊。还对中国在该领域的研究现状进行了简要的分析。从文献计量学角度揭示了全球北极底栖生物研究现状,为提升我国该领域研究的国际竞争力提供科学参考。     

Coevolutionary relationship between striatum size and social play in nonhuman primates

The striatum is a region of the brain specifically tied to the experience and anticipation of pleasure, reward, appropriate behavioral sequencing, cognition, learning, and social modulation. Furthermore, the striatum is connected neurologically and functionally to other brain regions associated with the exhibition of social play, such as the neocortex, cerebellum, and limbic system. For these reasons, the striatum is especially interesting to researchers of play behavior. Moreover, the caudate-putamen area of the striatum has been specifically implicated in laboratory studies of social play behavior. This study uses the phylogenetic comparative method of independent contrasts to test for an evolutionary relationship between striatum volume and a measure of social play in nonhuman primates. Relative volume of the primate striatum correlates with rate of social, but not nonsocial, play behavior across species, suggesting a coevolution of traits. The pleasurable and procedural aspects of social play behavior may be mediated in part by the striatum and further to its connection to dopaminergic pathways in the primate brain.     

A new index of interspecific competition for replacement and additive designs

The literature is reviewed to summarize the major indices of interspecific competition used in De Wit replacement experiments. Of the many indices that have been defined, some are less than clear as to their meaning, so interpretations are often difficult to make. In an effort to explore the performance of individual indices and to permit cross-correlation among indices, a series of hypothetical results in different competition scenarios is created. A standardized notation for all indices is also provided, along with equations and proofs. Nine indices are reviewed and analyzed for their behavior under the hypothetical scenarios and a new index that provides increased clarification and interpretability over other indices is proposed. Relative Yield Total, Aggressivity, and Relative Replacement Rate were shown to be poor measures of competition. Relative Crowding Coefficient has many restrictions to its use. The clearest index that includes two or more species is Relative Yield of Mixture. Indices that describe single species accurately were found to be Relative Yield (RY) and Relative Competition Intensity (RCI), both of which are mathematically convertible. An index introduced here, Change in Contribution (CC), is a single species index that differs from RY and RCI because it takes into account the overall biomass each species contributes.     

Tissue-based absolute quantification using large-scale TMT and LFQ experiments

Relative and absolute intensity-based protein quantification across cell lines, tissue atlases and tumour datasets is increasingly available in public datasets. These atlases enable researchers to explore fundamental biological questions, such as protein existence, expression location, quantity and correlation with RNA expression. Most studies provide MS1 feature-based label-free quantitative (LFQ) datasets; however, growing numbers of isobaric tandem mass tags (TMT) datasets remain unexplored. Here, we compare traditional intensity-based absolute quantification (iBAQ) proteome abundance ranking to an analogous method using reporter ion proteome abundance ranking with data from an experiment where LFQ and TMT were measured on the same samples. This new TMT method substitutes reporter ion intensities for MS1 feature intensities in the iBAQ framework. Additionally, we compared LFQ-iBAQ values to TMT-iBAQ values from two independent large-scale tissue atlas datasets (one LFQ and one TMT) using robust bottom-up proteomic identification, normalisation and quantitation workflows.     

Identifying overlapping and hierarchical thematic structures in networks of scholarly papers: a comparison of three approaches

The aim of this paper is to introduce and assess three algorithms for the identification of overlapping thematic structures in networks of papers. We implemented three recently proposed approaches to the identification of overlapping and hierarchical substructures in graphs and applied the corresponding algorithms to a network of 492 information-science papers coupled via their cited sources. The thematic substructures obtained and overlaps produced by the three hierarchical cluster algorithms were compared to a content-based categorisation, which we based on the interpretation of titles, abstracts, and keywords. We defined sets of papers dealing with three topics located on different levels of aggregation: h-index, webometrics, and bibliometrics. We identified these topics with branches in the dendrograms produced by the three cluster algorithms and compared the overlapping topics they detected with one another and with the three predefined paper sets. We discuss the advantages and drawbacks of applying the three approaches to paper networks in research fields.     

油松、侧柏林种内竞争特点的对比研究

植物竞争研究一直是种群生态学最活跃的研究领域之一,论文以林木个体相对胸径、相对树高、相对冠幅、相对冠长、相对冠面积、树冠体积、树冠伸展度、冠长率、圆满度、投影比、生长空间指标、生长空间竞争指数和简单竞争指数13个变量作为对比研究油松、侧柏林个体之间竞争关系的指数,采用这些指标的变异系数对其种内竞争的差异程度进行比较研究,并用这些变量作为评价指标将其竞争能力分为两类:种内竞争性强的树种和种内竞争性弱的树种。油松为种内竞争性强的树种,而侧柏为种内竞争性弱的树种,已有的研究结果已从生物量、根系特征、抗旱机理、耗水特性、分布及结构特点五个方面为这种划分提供了理论支持。     

The behavioral ecology and conservation of the orangutan (Pongo pygmaeus): A tale of two islands

Orangutans are the only great apes found outside of Africa. At present, they occur only on the two large Sunda‐shelf islands of Sumatra and Borneo. Most researchers recognize two separate subspecies, Pongo pygmaeus abelii in Sumatra and P.p. pygmaeus in Borneo.^1,2 Relative to other primates, they have a variety of unusual features. These large‐bodied frugivores are among the most solitary of anthropoid primates.^3–5 They are also highly dimorphic, with the average body mass (78 kg) of males being more than twice that of females (36 kg).⁶ Despite its large body size the red ape has more specialized morphological adaptations for arboreality than do the African great apes. Researchers generally recognize sexually mature male orangutans with two physically distinct morphs, a phenomenon described as bimaturism. Males of the relatively smaller morph are known for forcing copulations with adult females.^5,7–9.     

Gender-Heterogeneous Working Groups Produce Higher Quality Science

Here we present the first empirical evidence to support the hypothesis that a gender-heterogeneous problem-solving team generally produced journal articles perceived to be higher quality by peers than a team comprised of highly-performing individuals of the same gender. Although women were historically underrepresented as principal investigators of working groups, their frequency as PIs at the National Center for Ecological Analysis and Synthesis is now comparable to the national frequencies in biology and they are now equally qualified, in terms of their impact on the accumulation of ecological knowledge (as measured by the h-index). While women continue to be underrepresented as working group participants, peer-reviewed publications with gender-heterogeneous authorship teams received 34% more citations than publications produced by gender-uniform authorship teams. This suggests that peers citing these publications perceive publications that also happen to have gender-heterogeneous authorship teams as higher quality than publications with gender uniform authorship teams. Promoting diversity not only promotes representation and fairness but may lead to higher quality science.     

Size bias in traditional analyses of substitutive competition experiments

Summary The objective of this study was to examine the claim that traditional measures of competitive performance in substitutive experiments are biased towards larger plants. Results from a three-year diallele experiment of 6 marsh plant species were analyzed using both Relative Yields (a traditional analysis) and the Relative Efficiency Index (a recently proposed analysis presumed to be size-independent). In adddition, a mechanistic model of competition was used to explore the behavior of both methods of estimating competitive performance.Results from the three-year experiment showed that Relative Yields (RYs) were correlated with the initial sizes of plants for the first two years but not the third. By the third year, RYs were highly correlated with Relative Efficiency Index values (REIs) suggesting that the effects of initial size were eventually overcome. Model results showed that RYs are inherently biased in favor of larger plants during the early phases of competition while REIs are not. Further, model analysis confirmed that the size bias associated with RYs declines with increasing duration of the experiment. It is concluded that current generalizations about the relationship between plant size and competitive ability may be biased by the procedures used to analyze competition experiments.     

Measuring the Outcome of Biomedical Research: A Systematic Literature Review

Background

There is an increasing need to evaluate the production and impact of medical research produced by institutions. Many indicators exist, yet we do not have enough information about their relevance. The objective of this systematic review was (1) to identify all the indicators that could be used to measure the output and outcome of medical research carried out in institutions and (2) enlist their methodology, use, positive and negative points.

Methodology

We have searched 3 databases (Pubmed, Scopus, Web of Science) using the following keywords: [Research outcome* OR research output* OR bibliometric* OR scientometric* OR scientific production] AND [indicator* OR index* OR evaluation OR metrics]. We included articles presenting, discussing or evaluating indicators measuring the scientific production of an institution. The search was conducted by two independent authors using a standardised data extraction form. For each indicator we extracted its definition, calculation, its rationale and its positive and negative points. In order to reduce bias, data extraction and analysis was performed by two independent authors.

Findings

We included 76 articles. A total of 57 indicators were identified. We have classified those indicators into 6 categories: 9 indicators of research activity, 24 indicators of scientific production and impact, 5 indicators of collaboration, 7 indicators of industrial production, 4 indicators of dissemination, 8 indicators of health service impact. The most widely discussed and described is the h-index with 31 articles discussing it.

Discussion

The majority of indicators found are bibliometric indicators of scientific production and impact. Several indicators have been developed to improve the h-index. This indicator has also inspired the creation of two indicators to measure industrial production and collaboration. Several articles propose indicators measuring research impact without detailing a methodology for calculating them. Many bibliometric indicators identified have been created but have not been used or further discussed.