Resolving authorship disputes by mediation and arbitration.

BACKGROUND: Disputes over authorship are increasing. This paper examines the options that researchers have in resolving authorship disputes. Discussions about authorship disputes often address how to prevent disputes but rarely address how to resolve them. Both individuals and larger research communities are harmed by the limited options for dispute resolution. MAIN BODY: When authorship disputes arise after publication, most existing guidelines recommend that the authors work out the disputes between themselves. But this is unlikely to occur, because there are often large power differentials between team members, and institutions (e.g., universities, funding agencies) are unlikely to have authority over all team members. Other collaborative disciplines that deal with issues of collaborative creator credit could provide models for scientific authorship. Arbitration or mediation could provide solutions to authorship disputes where few presently exist. Because authors recognize journals' authority to make decisions about manuscripts submitted to the journal, journals are well placed to facilitate alternative dispute resolution processes. CONCLUSION: Rather than viewing authorship disputes as rare events that must be handled on a case by case basis, researchers and journals should view the potential for disputes as predictable, preventable, and soluble. Independent bodies that can offer alternative dispute resolution services to scientific collaborators and/or journals could quickly help research communities, particularly their most vulnerable members.

Filtering out parasites: sand crabs (Lepidopa benedicti) are infected by more parasites than sympatric mole crabs (Emerita benedicti).

Two digging decapod crustaceans, the sand crab species Lepidopa benedicti and the mole crab species Emerita benedicti, both live in the swash zone of fine sand beaches. They were examined for two parasites that infect decapod crustaceans in the region, an unidentified nematode previously shown to infect L. benedicti, and cestode tapeworm larvae, Polypocephalus sp., previously shown to infect shrimp (Litopenaeus setiferus). Lepidopa benedicti were almost always infected with both parasite species, while E. benedicti were rarely infected with either parasite species. This difference in infection pattern suggests that tapeworms are ingested during sediment feeding in L. benedicti, which E. benedicti avoid by filter feeding. Larger L. benedicti had more Polypocephalus sp. larvae. The thoracic ganglia, which make up the largest proportion of neural tissue, contained the largest numbers of Polypocephalus sp. larvae. Intensity of Polypocephalus sp. infection was not correlated with how long L. benedicti remained above sand in behavioural tests, suggesting that Polypocephalus sp. do not manipulate the sand crabs in a way that facilitates trophic transmission of the parasite. Litopenaeus setiferus may be a primary host for Polypocephalus sp., and L. benedict may be a secondary, auxiliary host.

Motor neurons in the escape response circuit of white shrimp (Litopenaeus setiferus).

Many decapod crustaceans perform escape tailflips with a neural circuit involving giant interneurons, a specialized fast flexor motor giant (MoG) neuron, populations of larger, less specialized fast flexor motor neurons, and fast extensor motor neurons. These escape-related neurons are well described in crayfish (Reptantia), but not in more basal decapod groups. To clarify the evolution of the escape circuit, I examined the fast flexor and fast extensor motor neurons of white shrimp (Litopenaeus setiferus; Dendrobranchiata) using backfilling. In crayfish, the MoGs in each abdominal ganglion are a bilateral pair of separate neurons. In L. setiferus, the MoGs have massive, possibly syncytial, cell bodies and fused axons. The non-MoG fast flexor motor neurons and fast extensor motor neurons are generally found in similar locations to where they are found in crayfish, but the number of motor neurons in both the flexor and extensor pools is smaller than in crayfish. The loss of fusion in the MoGs and increased number of fast motor neurons in reptantian decapods may be correlated with an increased reliance on non-giant mediated tailflipping.

Can crayfish take the heat? Procambarus clarkii show nociceptive behaviour to high temperature stimuli, but not low temperature or chemical stimuli.

Nociceptors are sensory neurons that are tuned to tissue damage. In many species, nociceptors are often stimulated by noxious extreme temperatures and by chemical agonists that do not damage tissue (e.g., capsaicin and isothiocyanate). We test whether crustaceans have nociceptors by examining nociceptive behaviours and neurophysiological responses to extreme temperatures and potentially nocigenic chemicals. Crayfish (Procambarus clarkii) respond quickly and strongly to high temperatures, and neurons in the antenna show increased responses to transient high temperature stimuli. Crayfish showed no difference in behavioural response to low temperature stimuli. Crayfish also showed no significant changes in behaviour when stimulated with capsaicin or isothiocyanate compared to controls, and neurons in the antenna did not change their firing rate following application of capsaicin or isothiocyanate. Noxious high temperatures appear to be a potentially ecologically relevant noxious stimulus for crayfish that can be detected by sensory neurons, which may be specialized nociceptors.

To Crowdfund Research, Scientists Must Build an Audience for Their Work.

As rates of traditional sources of scientific funding decline, scientists have become increasingly interested in crowdfunding as a means of bringing in new money for research. In fields where crowdfunding has become a major venue for fundraising such as the arts and technology, building an audience for one's work is key for successful crowdfunding. For science, to what extent does audience building, via engagement and outreach, increase a scientist's abilities to bring in money via crowdfunding? Here we report on an analysis of the #SciFund Challenge, a crowdfunding experiment in which 159 scientists attempted to crowdfund their research. Using data gathered from a survey of participants, internet metrics, and logs of project donations, we find that public engagement is the key to crowdfunding success. Building an audience or "fanbase" and actively engaging with that audience as well as seeking to broaden the reach of one's audience indirectly increases levels of funding. Audience size and effort interact to bring in more people to view a scientist's project proposal, leading to funding. We discuss how projects capable of raising levels of funds commensurate with traditional funding agencies will need to incorporate direct involvement of the public with science. We suggest that if scientists and research institutions wish to tap this new source of funds, they will need to encourage and reward activities that allow scientists to engage with the public.

Nematodes infect, but do not manipulate digging by, sand crabs, Lepidopa benedicti.

We examined sand crabs (Lepidopa benedicti) for endoparasites, and found the only parasite consistently infecting the studied population were small nematodes. Because many nematodes have complex life cycles involving multiple hosts, often strongly manipulating their hosts, we hypothesized that nematodes alter the behavior of their sand crab hosts. We predicted that more heavily infected crabs would spend more time above sand than less heavily infected crabs. Our data indicate infection by nematodes was not correlated with duration of time crabs spent above sand. We also suggest that organisms living in sandy beaches may benefit from relatively low parasite loads due to the low diversity of species in the habitat.

Position of larval tapeworms, Polypocephalus sp., in the ganglia of shrimp, Litopenaeus setiferus.

Parasites that invade the nervous system of their hosts have perhaps the best potential to manipulate their host's behavior, but how they manipulate the host, if they do at all, could depend on their position within the host's nervous system. We hypothesize that parasites that live in the nervous system of their host will be randomly distributed if they exert their influence through non-specific effects (i.e., general pathology), but that their position in the nervous system will be non-random if they exert their influence by targeting specific neural circuits. We recorded the position of larval tapeworms, Polypocephalus sp., in the abdominal ganglia of white shrimp, Litopenaeus setiferus. Tapeworms are more common within ganglia than in the section of the nerve cord between ganglia, even though the nerve cord has a greater volume than the ganglia. The tapeworms are also more abundant in the periphery of the ganglia. Because most synaptic connections are within the central region of the ganglion, such positioning may represent a trade-off between controlling the nervous system and damaging it.

Parasitic manipulation of hosts' phenotype, or how to make a zombie--an introduction to the symposium.

Nearly all animals in nature are infected by at least one parasite, and many of those parasites can significantly change the phenotype of their hosts, often in ways that increase the parasite's likelihood of transmission. Hosts' phenotypic changes are multidimensional, and manipulated traits include behavior, neurotransmission, coloration, morphology, and hormone levels. The field of parasitic manipulation of hosts' phenotype has now accrued many examples of systems where parasites manipulate the phenotypes of their hosts and focus has shifted to answering three main questions. First, through what mechanisms do parasites manipulate the hosts' phenotype? Parasites often induce changes in the hosts' phenotypes that neuroscientists are unable to recreate under laboratory conditions, suggesting that parasites may have much to teach us about links between the brain, immune system, and the expression of phenotype. Second, what are the ecological implications of phenotypic manipulation? Manipulated hosts are often abundant, and changes in their phenotype may have important population, community, and ecosystem-level implications. Finally, how did parasitic manipulation of hosts' phenotype evolve? The selective pressures faced by parasites are extremely complex, often with multiple hosts that are actively resisting infection, both in physiological and evolutionary time-scales. Here, we provide an overview of how the work presented in this special issue contributes to tackling these three main questions. Studies on parasites' manipulation of their hosts' phenotype are undertaken largely by parasitologists, and a major goal of this symposium is to recruit researchers from other fields to the study of these phenomena. Our ability to answer the three questions outlined above would be greatly enhanced by participation from individuals trained in the fields of, for example, neurobiology, physiology, immunology, ecology, evolutionary biology, and invertebrate biology. Conversely, because parasites that alter their hosts' phenotype are widespread, these fields will benefit from such study.

The vacuum shouts back: postpublication peer review on social media.

Social media has created new pathways for postpublication peer review, which regularly leads to corrections. Such online discussions are often resisted by authors and editors, however, and efforts to formalize postpublication peer review have not yet resonated with scientific communities.

Do Marmorkrebs, Procambarus fallax f. virginalis, threaten freshwater Japanese ecosystems?

BACKGROUND: One marbled crayfish, Marmorkrebs, Procambarus fallax f. virginalis (Hagen, 1870), was discovered in a natural ecosystem in Japan in 2006. Because Marmorkrebs are parthenogenetic, they could establish a population from only a single individual, and thus pose a risk for becoming established in Japan, as they have in other countries. There are two major reasons to be concerned about the possibility of Marmorkrebs establishing viable populations in Japan. First, Japan's only endemic crayfish, Cambaroides japonicus (De Haan, 1841), lives throughout Hokkaido and is endangered. Introduced Marmorkrebs are potential competitors that could further threaten C. japonicus. Second, Marmorkrebs live in rice paddies in Madagascar and consume rice. Marmorkrebs populations could reduce rice yields in Japan. RESULTS: We created five models in MaxEnt of the potential distribution of Marmorkrebs in Japan. All models showed eastern Honshu, Shikoku and Kyushu contain suitable habitats for Marmorkrebs. Hokkaido, the main habitat for C. japonicus, contained much less suitable habitat in most models, but is where the only Marmorkrebs in Japan to date was found. CONCLUSIONS: Marmorkrebs appear to be capable of establishing populations in Japan if introduced. They appear to pose minimal threat to C. japonicus, but may negatively affect rice production.

Polypocephalus sp. infects the nervous system and increases activity of commercially harvested white shrimp (Litopenaeus setiferus).

Larval tapeworms (Polypocephalus sp.) reside within the central nervous system of decapod crustaceans. Living within the nervous system would seem to create an excellent opportunity for the parasites to manipulate the behavior of their hosts, so we tested the hypothesis that behavior of white shrimp ( Litopenaeus setiferus ) would be correlated with the level of parasitic infection. We videorecorded the behavior of L. setiferus for 8 hr, then examined the nervous system and digestive glands for parasite infection. Larval Polypocephalus sp. were found in the nerve cord, often in large numbers, but only very rarely in the digestive gland, which was typically infected by the larval stage of the nematode, Hysterothylacium sp. There were significantly more Polypocephalus larvae in the abdominal and thoracic ganglia than the subesophageal ganglia and brain. Walking, but not swimming, was significantly and positively related to the number of Polypocephalus sp. lodged in nervous tissue, as well as shrimp carapace length. Polypocephalus sp. is 1 of only a few parasites residing inside the host nervous system and it may, therefore, be suitable for investigating mechanisms of parasite manipulation of invertebrate host behavior.

Do decapod crustaceans have nociceptors for extreme pH?

BACKGROUND: Nociception is the physiological detection of noxious stimuli. Because of its obvious importance, nociception is expected to be widespread across animal taxa and to trigger robust behaviours reliably. Nociception in invertebrates, such as crustaceans, is poorly studied. METHODOLOGY/PRINCIPAL FINDINGS: THREE DECAPOD CRUSTACEAN SPECIES WERE TESTED FOR NOCICEPTIVE BEHAVIOUR: Louisiana red swamp crayfish (Procambarus clarkii), white shrimp (Litopenaeus setiferus), and grass shrimp (Palaemonetes sp.). Applying sodium hydroxide, hydrochloric acid, or benzocaine to the antennae caused no change in behaviour in the three species compared to controls. Animals did not groom the stimulated antenna, and there was no difference in movement of treated individuals and controls. Extracellular recordings of antennal nerves in P. clarkii revealed continual spontaneous activity, but no neurons that were reliably excited by the application of concentrated sodium hydroxide or hydrochloric acid. CONCLUSIONS/SIGNIFICANCE: Previously reported responses to extreme pH are either not consistently evoked across species or were mischaracterized as nociception. There was no behavioural or physiological evidence that the antennae contained specialized nociceptors that responded to pH.

Turning loss into opportunity: the key deletion of an escape circuit in decapod crustaceans.

Decapod crustacean escape responses are adaptive behaviors whose neural bases are well understood. The escape circuit is composed of giant neurons. Lateral giant interneurons (LGs) respond to posterior stimuli by generating a somersaulting tailflip; medial giant interneurons (MGs) respond to anterior stimuli with a backwards tailflip. Both sets of interneurons connect to giant fast flexor motor neurons (MoGs). Most features of the escape circuit are thought to result from strong selective pressure to respond to stimuli in the shortest possible time. Despite the apparent advantages of the escape circuit, it has been lost in multiple taxa independently. Some losses of the escape circuit may be rare cases of disaptation, where organisms are less well adapted than related species (i.e., those with the escape circuit). The losses of the escape circuit might be key deletions that promoted the radiation of decapod crustaceans by increasing selection pressure for species to evolve new anti-predator strategies and removing constraints against change.

Loss of escape-related giant neurons in a spiny lobster, Panulirus argus.

When attacked, many decapod crustaceans perform tailflips, which are triggered by a neural circuit that includes lateral giant interneurons, medial giant interneurons, and fast flexor motor giant neurons (MoGs). Slipper lobsters (Scyllaridae) lack these giant neurons, and it has been hypothesized that behavioral (e.g., digging) and morphological (e.g., flattening and armor) specializations in this group caused the loss of escape-related giant neurons. To test this hypothesis, we examined a species of spiny lobster, Panulirus argus. Spiny lobsters belong to the sister taxon of the scyllarids, but they have a more crayfish-like morphology than scyllarids and were predicted to have escape-related giant neurons. Ventral nerve cords of P. argus were examined using paraffin-embedded sections and cobalt backfills. We found no escape-related giant neurons and no large axon profiles in the dorsal region of the nerve cord of P. argus. Cobalt backfills showed one fewer fast flexor motor neuron than in species with MoGs and none of the fast flexor motor neurons show any of the anatomical specializations of MoGs. This suggests that all palinuran species lack this giant escape circuit, and that the loss of rapid escape behavior preceded, and may have driven, alternative predator avoidance and anti-predator strategies in palinurans.

Mechanisms of behavioral switching.

No animal performs only one behavior, so nervous systems must have ways to switch between different behaviors. In this issue of Journal of Comparative Physiology A, several papers discuss how nervous systems achieve this ordered switching between behaviors, from short-term motor control problems, to medium-term decision making based on past experience, to long-term modulation and selection of overall behavioral strategies, such as dominance versus subordinance.

Loss of escape responses and giant neurons in the tailflipping circuits of slipper lobsters, Ibacus spp. (Decapoda, Palinura, Scyllaridae).

In many decapod crustaceans, escape tailflips are triggered by lateral giant (LG) and medial giant (MG) interneurons, which connect to motor giant (MoG) abdominal flexor neurons. Several decapods have lost some or all of these giant neurons, however. Because escape-related giant neurons have not been documented in palinurans, I examined tailflipping and abdominal nerve cords for giant neurons in two scyllarid lobster species, Ibacus peronii and Ibacus alticrenatus. Unlike decapods with giant neurons, Ibacus do not tailflip in response to sudden taps. Ibacus can perform non-giant tailflipping: the frequency of tailflips during swimming is adjusted by altering the gap between each individual tailflip. Abdominal nerve cord sections show no LG or MG interneurons. Backfilling nerve 3 of abdominal ganglia revealed no MoG neurons, and the fast flexor motor neuron population is otherwise identical to that described for crayfish. The loss of giant neurons in Ibacus represents an independent deletion of these cells compared to other reptantian decapods known to have lost these giant neurons. This loss is correlated with the normal posture in scyllarids, in which the last two abdominal segments are flexed, and an alternative defensive strategy, concealment by digging into sand.