A Proposal for a New #Altmetric, the Influence Score, to Accompany the H-Index and to Help Evaluate a Scientist’s Impact on Society

The H-index is among the most widely used metrics for evaluating the quality and quantity of a scientist’s publications; but what about their influence on society? Here I introduce the Influence Score that can help an outside reviewer better understand a person’s impact not just among other scientists but among the general public and those outside of academia. If the ultimate goal is to evaluate a person’s true overall role as a scientist, I think we should be considering how they communicate with all people not just other scientists (which is the case with the H-index). The new index can be used to accompany the H-index, but also incorporates it. All elements of the Influence Score can be looked up through simple Google and Twitter/Facebook searches.

            The H-index can be easily calculated in Google Scholar, I prefer it to the Web of Science or Scopus because Google Scholar counts books and other

Fig.1. Google Scholar Profile Page Showing H-Index in Red Box.

non-traditional peer-reviewed publications: and it is free! To calculate the H-index you essentially count down the number of publications and their citations until the numbers no longer overlap. A person with an H-index of 5, has at least 5 papers with 5 citations. Read more HERE to learn how to calculate the H-index.) Because a scientist’s main role is still to communicate their science among peers (via peer review), the Influence Score multiples their H-index by 100, and down weights the other elements, which are a little easier to accumulate (e.g., # of twitter followers).  I chose the H-index over say, total number of citations (which might be more similar to # of followers), because it is easier to calculate for a given researcher, especially one without a Google Scholar profile (Fig.1). 

            The other measures of the Influence score includes a measure of their visibility with the press (i.e, the Press Index or P-Index for short). Using Google News, one simple puts the person’s name in the search box and counts the number of articles that are found, which Google also does for you (Fig.2). Because

Fig 2. Red box shows Google News P-index.

Google News is only searching through a relatively recent window of time, few scientists will have much more than a few articles about them. Sometimes it is worth googling the person with “science” following their name, as I did for James Watson (e.g., “James Watson science”), to distinguish him from other news articles about people with the same name. This measure largely is to bump up those scientists truly making a social impact as newsmakers. That is without bumping them up too much, I’m trying to avoid giving too much influence to “celebrity scientists” that don’t do much science of their own. Therefore, I suggest that you divide the total number of search results of the Press Index by 100 so that this score is not completely overweighing the person’s academic accomplishments represented by the (albeit crude) measure of the H-index. Folks like James Cameron that are great promoters of science, but are best known for other things, are intentionally excluded here. If someone could separate press about science related activities from all others, they obviously could still be included. This is also the most dynamic element of the score because it can change so rapidly. Jane Goodall can skyrocket to the top of the list with the publication of a new book.

Fig.3. Twitter and Facebook Fan pages showing # of followers.

            The third part of the Influence Score considers your sway in social media (i.e, the Social Media Index or SM-index for short), specifically Twitter or Facebook. For someone on Twitter you get 1pt for every follower. For someone not on Twitter but that has either a Facebook “Fan” Page or Facebook “followers,” you get 1pt per fan or follower. You don’t get points for regular old Facebook “friends” because that isn’t necessarily measuring your scientific influence. If they have both a Facebook Fan page and a Twitter handle you only get points for whichever is the higher value. To learn more about the role of twitter for outreach read David Shiffman’s @whysharksmatter excellent article HERE).  As with the Press-Index you divide the total number by 100; again this is to allow the more academic H-index to still have some weight. The reason being that someone with 40,000 Twitter followers and an H-index of 0 might not really be more influential than a scientist with an H-index of 40 and only 4000 twitter followers.

            The Influence Score is then the total of your (H-Index X 100) + (Press index/100) + (Social Media-Index/100). I would round this to the nearest integer. All three can be discovered relatively easily through searches (e.g. GoogleScholar, GoogleNews, and a Facebook/Twitter search). Below I’ve compiled a list of some of the most well known scientists and have calculated their Influence Score. I’ve also added folks randomly that I admire that might not be the most famous folks but that I hope will be one day, I think adopting the Influence Score might help them get the recognition they deserve for the impact they have in society. This metric is imperfect: but I hope it is a good start.

I would like to thank Paige Brown @FromTheLabBench and her class #manship4002 for helping me figure out a more user-friendly way to compile this Influence Score. Also would like to thank Joshua Drew (@Drew_Lab) and David Shiffman (@WhySharksMatter) for their comments and advice.

Scientist	H-Index x 100	Press Index /100 (total articles according to GoogleNews)	Social Media Index /100 (Twitter/or Facebook followers)	Influence Score
Stephen Hawking	8400	781	9,591	18,772
Neil deGrasse Tyson	600	14	16,100	16,714
Richard Dawkins	4000	36	8,870	12,906
Bill Nye	100	140	11,500	11,740
Jared Diamond	10800	104	208	11,112
J. Craig Venter	9600	20	186	9,806
E.O. Wilson	8800	64	12	8,876
Steven Chu	8200	17	212	8,429
Buzz Aldrin	0	10	8,150	8,160
Sean B. Carroll	7500	.01	0	7,500
Jane Goodall	4500	21	1,650	6,171
Ed Yong	0	.12	4,660	4,660
Jane Lubchenco	4600	.71	0	4,601
Jack Horner	3600	.16	18	3,618
Carl Zimmer	1700	3.83	1700	3,404
Amanda Vincent	3200	0	3	3,203
Neil Shubin	3100	3.94	9	3,113
David Attenborough	1500	45	1,423	2,968
James Watson	2600	18	0	2,618
Hope Jahren	2200	0.01	24	2,224
Eugenie Clark	2200	0.01	0	2,200
Eugenie Scott	1800	0.06	71	1,871
David Shiffman	200	0.04	1,470	1,670
Sylvia Earle	1400	1	213	1,614

Note: As always I would like feedback on this post and if people have suggestions for changes or additions to the metric. Please e-mail me at prosanta@lsu.edu

Piranha Frenzy or just Media Frenzy?

Piranhas did not "attack" 70+ people in Argentina on Christmas day in a feeding frenzy; the only frenzy here is the news medias desire to report this story (ABC, Fox, Discovery, BBC, etc. have all reported it). From what I can gather, several people, one a young girl, were bitten in the Parana River near Rosario, Argentina. Some people may have lost parts of (and perhaps entire) digits according to some of the reports. The Parana River does have piranhas but none at the scene said it was piranhas, but rather ‘palometas.’ Piranhas in a feeding frenzy can consume animals as large as humans in seconds, but they are very picky about their food source and reports of human attacks are few (see paper here). Most people who lose a finger to a piranha have lost it after mishandling it on a hook or in a net out of the water. Piranhas in a frenzy will take off more than your finger tip. Several news agencies report the fishes are “palometas’ and show images or mention a common species of jack; however, all jacks are marine so they wouldn’t be in the freshwaters of the Parana River. Pygocentrus palometa was described as a Venezuelan piranha species that is likely not a valid species (see Catalog of Fishes), and not known from Argentina. My guess is a few people were bitten by other biting tetras common to the area (Hoplias?); these bites may have scared lots of other people out of the water.

[UPDATE: I do think these were piranha bites now, having talked to some fellow ichthyologists. These were probably defensive bites from one of the local species they call palometas - Serrasalmus maculatus, S. spilopleura, or Pygocentrus nattereri]

Piranha 3D is a great movie, but it is not real.

Given the high temperatures of the day perhaps more people were bathing than usual and if the area is dammed, as much of the Parana is, the fish may have felt trapped, especially if breeding. These fishes were likely biting as a defense from the many people in the crowded water. If piranhas want to eat something, they will do so quite thoroughly, they won't peck. They will bite to protect themselves and that is not what I would call an "attack."

How this became an international media story is another mystery, but the name of the river likely caused some to guess that piranhas were the culprits. That, and some good pics of people with bloody toes.

Unfortunately, it does sound like some people were hurt, I hope they recover quickly. However, the news media should be accountable for the many errors in this sensationalized story.

On Sarcopterygii

Introduction

Sarcopterygii, or the lobe-finned fishes, includes the coelacanths, lungfishes, fishes involved in the transition to land, and all tetrapods (mammals, amphibians, and reptiles [the birds, turtles, crocodiles, and squamates]). The lobe-finned fishes are Devonian in age and the sister group to Actinopterygii, or ray-finned fishes. Actinopterygii and Sarcopterygii are nearly of equal size (c. 30,000 spp. each). Actinopterygii is dominated by the teleost fishes, just as Sarcopterygii is dominated by tetrapods. In this essay, the focus will be the non-tetrapod members of Sarcopterygii, as I study fishes; however, it is worth noting many of the skeletal elements and organ systems of tetrapods originated in our aquatic sarcopterygian ancestors.  Had actinopterygians been the group to take charge as the vertebrate class to dominate land, terrestrial vertebrates would look very different.  It is likely that we would breathe through our mouths alone or through our skin, be much smaller, and be hugging the ground with soft rays holding us up against gravity rather than digits and wrist bones. It was the advent of internal nostrils, or choanae, in aquatic sarcopterygians that permitted us to breathe through our noses;

The rare ray-finned fish that can "walk" on land, the mudskipper. Image from http://www.studentsoftheworld.info/sites/animals/shadows.php

likewise, our forelimb and hindlimb bones all originated with lobe-finned fishes. As it were, the story of the water to land transition is remarkably well known given an excellent series of transitional fossils that fill the steps in the gap between “fishes” and early tetrapods. Some of these intermediate fossils, like the famous Tiktallik rosea, tell us about the evolution of everything from the “neck” to the origin of sturdy ribs and limbs. Luckily for us, there are still extant aquatic lobe-finned fishes. Although they were not directly involved in the terrestrial transition, they can tell us a great deal about how ancient lobed-fins lived. Today only lungfishes and coelacanths survive as the aquatic members of this lineage. These two forms themselves have continued to evolve from our common ancestor, and they each have an amazing array of novelties.

Evolution and Systematics

            Coelacanths belong to Actinistia (or Coelacanthimorpha), which has a long fossil record (Mid-Devonian to Late Cretaceous) and that is species rich relative to the two species extant today (83 valid fossil species in nine worldwide families). Members of Actinistia are easily recognized by their tri-lobed diphycercal tail (the vertebral column enters the middle lobe). Known as fossils from both marine and freshwater deposits, they were thought to have gone extinct over 65 million years ago, until a living species was discovered in 1938 to much fanfare. (The discovery of both living species have spectacular stories behind them. See www.dinofish.com)

          Lungfishes are members of Dipnoi (themselves part of the larger group Porolepimorpha, largely made up of extinct forms). This clade also evolved in Early Devonian freshwaters, and is represented in the fossil record by more than 100 species in more than 50 genera. Their great fossil record of lungfishes was likely aided by their ability to estivate. These fishes can protect themselves from drought by building a mucous-mud cocoon. They enter periods of estivation that in modern forms can last up to four years; many individuals in the past have expired waiting for that next rain. These individuals and their cocoons make for spectacular, if plaintive, fossils. From fossil forms, we see a trend toward the reduction of bone (in the skull, scales, and fins). Unique plate-like grinding toothplates easily help place extinct and extant forms as each other’s closest relatives.

            Tetrapodomorphs are the intermediate forms between the first tetrapods to conquer land and their piscine ancestors. They are all limbed, extinct early Devonian forms, and air-breathers. They include Osteolepimorpha (rhipidistians), Rhizodontiformes, and Elpistostegalians. It is the tetrapodomorphs, in particular the Elpistostegalians (which includes Tiktallik) and not coelacanths or lungfishes, that are the closest relatives to tetrapods.  

A modern day coelacanth, Latimeria chalumnae.

Physical Characteristics

Both lungfishes and coelacanths can reach large sizes, approaching 2 m, although lungfishes are much more slender bodied. Both groups have a number of derived features that make each group unique. Coelacanths have a special rostral electroreceptive organ, a vertebral column that is secondarily reduced, no maxilla, and an intercranial joint found in many extinct fish lineages but no other living species. Coelacanths have only external nostrils (no choanae) and a large fat-filled gas bladder (no lung). These two latter features have been used by some authors as evidence that these fishes are ancestral to lungfishes (which have both lungs and choanae), but these primitive features may have more to do with the current ecology of these animals than their biological history.

            There are three extant families of lungfishes: Ceratodontidae of Australia, Lepidosirenidae of South America, and Protopteridae of Africa.  Lungfishes are easily recognized by their continuous rear fins that connect their dorsal, caudal, and anal fins.  The Australian Lungfish (Neoceratodus forsteri) has a number of pleisiomorphic morphological features that resemble fossil forms more so than the other extant lineages. Instead of the tiny worm-like fins of the other species, the Australian form has broad flat fins, large scales, and unpaired lungs (versus small scales and paired lungs in the other taxa). Lungfishes eat both plant and animal material, including ray-finned fishes and invertebrates.

Reproductive Biology

              Coelacanths are ovoviviparous; they retain eggs in the body cavity. The young hatch and develop internally. African and South American lungfishes make nests where females lay eggs, and males guard the nests. The Australian species lays its eggs on aquatic plants. The African and South American forms have young with large external gills that often cause them to be mistaken for salamanders.

Conservation

               The conservation status of most lungfishes is poorly known, but the Australian lungfish is uncommon, confined to just four rivers in Queensland.

Among coelacanths, Latimeria chalumnae is found off the eastern to southeastern coast of Africa and around the Comoros Islands and Madagascar, and L. menadoensis is only known from Sulawesi, Indonesia. Coelacanths are found at depths beyond the range of most artisanal fishermen (150 to 253m), but accidental capture occurs frequently enough that some estimate that as much as 5% of the adult population is captured annually. Coelacanths aggregate and rest in caves; they may be limited by the number of these sites that are available.  

Significance to Humans

               As Moyle and Cech state, “probably no single event in the history of ichthyology has received more public attention than the discovery of the coelacanth (Latimeria chalumnae) in 1938.” The discovery of this large, deep sea, limbed, fish-link-to-man made for fantastic headlines.  Lungfishes, too, have a spectacular mix of features that make them popular aquarium fishes. Both sarcopterygian fish clades are important to humans for their unique position on the other side of the coin to the vertebrate transition to land.

References

Bemis, W.E, Burggren, W.W., Kemp, N.E. (1987) The biology and evolution of lungfishes. Alan R. Liss, Inc., New York.

Carroll, R.L. 1996. Vertebrate paleontology and evolution. W.H. Freeman. New York.

Helfman, G.S., Collette, B.B, Facey, D.E., Bowen, B.W. 2009. The diversity of fishes, 2^nd ed. Wiley Blackwell, West Sussex, UK.

Moyle, P.B., and Cech Jr., J.J. (2004) Fishes, an introduction to ichthyology, 5^th edition. Prentice Hall, New Jersey.

Musick, J.A., Bruton, M.N., Balon, E.K. (1991) The biology of Latimeria chalumnae and             evolution of coelacanths.  Environmental Biology of Fishes 32, 1-435.