bluuebunny/crossref_metadata_2025 huggingface dataset:
A genetic interaction map of cell cycle regulators
Authors: Billmann Maximilian , Horn Thomas , Fischer Bernd , Sandmann Thomas , Huber Wolfgang , Boutros Michael
Published: February 2016

Cell-based RNA interference (RNAi) is a powerful approach to screen for modulators of many cellular processes. However, resulting candidate gene lists from cell-based assays comprise diverse effectors, both direct and indirect, and further dissecting their functions can be challenging. Here we screened a genome-wide RNAi library for modulators of mitosis and cytokinesis in Drosophila S2 cells. The screen identified many previously known genes as well as modulators that have previously not been connected to cell cycle control. We then characterized ∼300 candidate modifiers further by genetic interaction analysis using double RNAi and a multiparametric, imaging-based assay. We found that analyzing cell cycle–relevant phenotypes increased the sensitivity for associating novel gene function. Genetic interaction maps based on mitotic index and nuclear size grouped candidates into known regulatory complexes of mitosis or cytokinesis, respectively, and predicted previously uncharacterized components of known processes. For example, we confirmed a role for the Drosophila CCR4 mRNA processing complex component l(2)NC136 during the mitotic exit. Our results show that the combination of genome-scale RNAi screening and genetic interaction analysis using process-directed phenotypes provides a powerful two-step approach to assigning components to specific pathways and complexes.
Sorting nexin 27 couples PTHR trafficking to retromer for signal regulation in osteoblasts during bone growth
Authors: Chan Audrey S. M. , Clairfeuille Thomas , Landao-Bassonga Euphemie , Kinna Genevieve , Ng Pei Ying , Loo Li Shen , Cheng Tak Sum , Zheng Minghao , Hong Wanjin , Teasdale Rohan D. , Collins Brett M. , Pavlos Nathan J.
Published: February 2016

The parathyroid hormone 1 receptor (PTHR) is central to the process of bone formation and remodeling. PTHR signaling requires receptor internalization into endosomes, which is then terminated by recycling or degradation. Here we show that sorting nexin 27 (SNX27) functions as an adaptor that couples PTHR to the retromer trafficking complex. SNX27 binds directly to the C-terminal PDZ-binding motif of PTHR, wiring it to retromer for endosomal sorting. The structure of SNX27 bound to the PTHR motif reveals a high-affinity interface involving conserved electrostatic interactions. Mechanistically, depletion of SNX27 or retromer augments intracellular PTHR signaling in endosomes. Osteoblasts genetically lacking SNX27 show similar disruptions in PTHR signaling and greatly reduced capacity for bone mineralization, contributing to profound skeletal deficits in SNX27-knockout mice. Taken together, our data support a critical role for SNX27-retromer mediated transport of PTHR in normal bone development.
Tectonic calibrations in molecular dating
Authors: Kodandaramaiah Ullasa
Published: February 2016

Molecular dating techniques require the use of calibrations, which are usually fossil or geological vicariance-based. Fossil calibrations have been criticised because they result only in minimum age estimates. Based on a historical biogeographic perspective, I suggest that vicariance-based calibrations are more dangerous. Almost all analytical methods in historical biogeography are strongly biased towards inferring vicariance, hence vicariance identified through such methods is unreliable. Other studies, especially of groups found on Gondwanan fragments, have simply assumed vicariance. Although it was previously believed that vicariance was the predominant mode of speciation, mounting evidence now indicates that speciation by dispersal is common, dominating vicariance in several groups. Moreover, the possibility of speciation having occurred before the said geological event cannot be precluded. Thus, geological calibrations can under- or overestimate times, whereas fossil calibrations always result in minimum estimates. Another major drawback of vicariant calibrations is the problem of circular reasoning when the resulting estimates are used to infer ages of biogeographic events. I argue that fossil-based dating is a superior alternative to vicariance, primarily because the strongest assumption in the latter, that speciation was caused by the said geological process, is more often than not the most tenuous. When authors prefer to use a combination of fossil and vicariant calibrations, one suggestion is to report results both with and without inclusion of the geological constraints. Relying solely on vicariant calibrations should be strictly avoided.
Seasonal changes in group size and composition of Arabian sand gazelle Gazella subgutturosa marica Thomas, 1897 during a period of drought in central western Saudi Arabia
Authors: Cunningham Peter Low , Wronski Torsten
Published: February 2016

Group size variations of the Arabian sand gazelle Gazella subgutturosa marica were studied during a period of drought at the Mahazat as-Sayd Protected Area in central western Saudi Arabia. Significant differences in median group sizes were observed between all seasons except summer. Single animals were observed mainly during summer while group sizes exceeding 10 individuals were observed mainly during winter. Solitary male and female groups were typically observed during winter and mixed groups mainly during the autumn rutting period. Most mixed groups were two to four times larger during winter than summer. The adult sex ratio (male: female) for all seasons combined was in parity and highest during autumn (1:1.23), probably as a result of prolonged drought conditions. The variability in group structure related to environmental conditions may be one factor permitting G. s. marica to adapt to hyper-arid habitats and climatic regimes in central western Saudi Arabia. The value of continuous monitoring of the gazelle population is emphasised for this drought prone region.
Inter-signal interaction and uncertain information in anuran multimodal signals
Authors: Taylor Ryan C. , Klein Barrett A. , Ryan Michael J.
Published: February 2016

Disentangling the influence of multiple signal components on receivers and elucidating general processes influencing complex signal evolution are difficult tasks. In this study we test mate preferences of female squirrel treefrogs Hyla squirella and female túngara frogs Physalaemus pustulosus for similar combinations of acoustic and visual components of their multimodal courtship signals. In a two-choice playback experiment with squirrel treefrogs, the visual stimulus of a male model significantly increased the attractivness of a relatively unattractive slow call rate. A previous study demonstrated that faster call rates are more attractive to female squirrel treefrogs, and all else being equal, models of male frogs with large body stripes are more attractive. In a similar experiment with female túngara frogs, the visual stimulus of a robotic frog failed to increase the attractiveness of a relatively unattractive call. Females also showed no preference for the distinct stripe on the robot that males commonly bear on their throat. Thus, features of conspicuous signal components such as body stripes are not universally important and signal function is likely to differ even among species with similar ecologies and communication systems. Finally, we discuss the putative information content of anuran signals and suggest that the categorization of redundant versus multiple messages may not be sufficient as a general explanation for the evolution of multimodal signaling. Instead of relying on untested assumptions concerning the information content of signals, we discuss the value of initially collecting comparative empirical data sets related to receiver responses.
Can rarefaction be used to estimate song repertoire size in birds?
Authors: Peshek Kathleen R. , Blumstein Daniel T.
Published: February 2016

Song repertoire size is the number of distinct syllables, phrases, or song types produced by an individual or population. Repertoire size estimation is particularly difficult for species that produce highly variable songs and those that produce many song types. Estimating repertoire size is important for ecological and evolutionary studies of speciation, studies of sexual selection, as well as studies of how species may adapt their songs to various acoustic environments. There are several methods to estimate repertoire size, however prior studies discovered that all but a full numerical count of song types might have substantial inaccuracies associated with them. We evaluated a somewhat novel approach to estimate repertoire size—rarefaction; a technique ecologists use to measure species diversity on individual and population levels. Using the syllables within American robins’ Turdus migratorius repertoire, we compared the most commonly used techniques of estimating repertoires to the results of a rarefaction analysis. American robins have elaborate and unique songs with few syllables shared between individuals, and there is no evidence that robins mimic their neighbors. Thus, they are an ideal system in which to compare techniques. We found that the rarefaction technique results resembled that of the numerical count, and were better than two alternative methods (behavioral accumulation curves, and capture-recapture) to estimate syllable repertoire size. Future estimates of repertoire size, particularly in vocally complex species, may benefit from using rarefaction techniques when numerical counts are unable to be performed.
Avian succession along ecological gradients: Insight from species-poor and species-rich communities of Sylvia warblers
Authors: Guillaumet Alban , Prodon Roger
Published: February 2016

The mechanisms responsible for species replacement during ecological successions is a long-standing and open debate. In this study, we examined the distribution of the Sardinian warbler Sylvia melanocephala along two grassland-to-forest gradients, one in a high-diversity area (Albera-Aspres chain in Catalonia: eight Sylvia warbler species) and one in a low-diversity area (Mount Hymittos in Greece: four species). In Catalonia, distribution models suggested that the apparent exclusion of S. melanocephala from the open and forest ends of the gradient may be explained entirely by the preference of S. melanocephala for mid-successional shrublands. However, a joint analysis of both data sets revealed that: 1) S. melanocephala was more evenly distributed along the vegetation gradient in Greece, suggesting ecological release in the low-diversity area; and 2) a distribution model assuming interspecific competition (based on the distribution of Sylvia species showing a negative co-occurrence pattern with S. melanocephala) had a significantly higher predictive ability than a distribution model based on habitat variables alone. Our study supports the view that species turnover along ecological gradients generally results from a combination of intrinsic preferences and interspecific competition.
Vertebrate species introductions in the United States and its territories
Authors: Witmer Gary W. , Fuller Pam L.
Published: February 2016

At least 1,065 introduced vertebrate species have been introduced in the United States and its territories, including at least 86 mammalian, 127 avian, 179 reptilian/amphibian, and 673 fish species. Examples in each major taxonomic group include domestic cat, small Indian mongoose, red fox, goat, pig, rabbit, rats, house mouse, gray squirrel, nutria, starling, Indian common myna, red-vented bulbul, brown treesnake, red-eared slider, brown trout, tilapia, and grass carp. We briefly review some of these species and the types of damage they cause. We then review the basic types of methods used for control or eradication of each taxonomic group, including physical, chemical, biological, and cultural methods. We discuss some of the challenges in managing these species, including issues with the use of toxicants, land access, public attitudes, and monitoring difficulties. Finally, we list some ongoing research and future research needs, including improved detection methods, improved attractants, improved barriers, improved capture methods, fertility control, and risk assessment methods.
Estimated prevalence of Echinococcus multilocularis in raccoon dogs Nyctereutes procyonoides in northern Brandenburg, Germany
Authors: Schwarz Sabine , Sutor Astrid , Staubach Christoph , Mattis Roswitha , Tackmann Kirsten , Conraths Franz Josef
Published: February 2016

Human alveolar echinococcosis, caused by the larval stage of the small fox tapeworm, is a lethal zoonotic infection if left untreated. E. multilocularis is distributed in the Northern Hemisphere and lives in the small intestines of carnivores, mainly canids. The main definitive host of E. multilocularis in European countries is the red fox Vulpes vulpes and in the last ten years new endemic areas for the parasite in Central Europe have been identified. In some areas, for instance in Germany, the raccoon dog Nyctereutes procyonoides - a spreading neozoon - must be regarded as an additional definitive host for E. multilocularis. In 2001 this parasite was found for the first time in raccoon dogs in the Federal State of Brandenburg, Germany. Between 2000 and 2008, 1,252 raccoon dogs from Brandenburg were examined by the Intestinal Scraping Technique. The majority of samples were obtained in five northern counties and all 60 animals that tested positive for E. multilocularis were located there. The estimated true prevalence calculated by a beta-binomial- model ranged from 6%–12%.
Thermal preference, thermal tolerance and the thermal dependence of digestive performance in two Phrynocephalus lizards (Agamidae), with a review of species studied
Authors: Qu Yanfu , Li Hong , Gao Jianfang , Xu Xuefeng , Ji Xiang
Published: February 2016

We reported data on thermal preference, thermal tolerance and the thermal dependence of digestive performance for two Phrynocephalus lizards (P. frontalis and P. versicolor), and compared data among lizards so far studied worldwide. Mean values for selected body temperature (Tsel) and critical thermal maximum (CTMax) were greater in P. versicolor, whereas mean values for critical thermal minimum (CTMin) did not differ between the two species. The two lizards differed in food intake, but not in food passage time, apparent digestive coefficient (ADC) and assimilation efficiency (AE), across the experimental temperatures. Four general conclusions can be drawn from published data. Firstly, thermal preference and thermal tolerance differ among lizards differing in distribution, temporal activity pattern and habitat use. Lizards in thermally more variable regions are better able to tolerate low and high temperatures. Diurnal lizards generally select higher body temperatures than nocturnal lizards, and lizards using habitats with direct sun exposure generally selected higher body temperatures and are better able to tolerate high temperatures. Secondly, CTMax is positively correlated with Tsel. Lizards more likely exposed to extremely high temperatures while active select higher body temperatures than those using shaded habitats. Thirdly, the effects of body temperature on food intake, food passage time, ADC and AE differ among lizards, but it seems to be common among lizards that ADC and AE are less thermally sensitive than food intake and food passage time. Lastly, ADC is dependent on the type of food ingested, with insectivorous lizards digesting food more efficiently than herbivorous lizards.
Location of rut stands vs. mating opportunities in Przewalski’s gazelle: A field test of the “Resource-based Hypothesis” and “Female Traffic Version of the Hotspot Hypothesis”
Authors: You Zhangqiang , Jiang Zhigang , Li Chunwang
Published: February 2016

We studied the mating tactics of Przewalski’s gazelle on the Qinghai-Tibetan Plateau from 2002 to 2005. Przewalski’s gazelle is a cluster mating animal whereby female groups, including juveniles, travel to and from their resting grounds along fixed routes and dominant males stand on or near these travel routes during rut. To explain rut patterns in male gazelles, we tested predictions arising from the “Resource-based Hypothesis” and “Female Traffic Version of the Hotspot Hypothesis”. We marked the location of each rut stand and female travel route, measured food availability in each rut stand and recorded the mating opportunities of rut stand owners. We also conducted a field experiment to force female groups to change their daily travel route, and observed whether males abandon their original rut stands and shift their rut stands to new travel routes of females during the 3rd rut. We found that: (1) male gazelle defending rut stands closer to a female travel route had a higher chance of mating; (2) food resources within rut stands had no effect on mating opportunities of the rut stand owner; (3) when the female travel route was obstructed, female groups changed grazing sites, and all males abandoned their original rut stands and defended new rut stands along the new female travel route. In conclusion, the location of rut stands in relation to female travel routes is the ultimate factor for consolidating mating opportunities in male gazelle, supporting the “Female Route Version of Hotspot Hypothesis”.
Bioacoustic variation of swimbladder disturbance sounds in Neotropical doradoid catfishes (Siluriformes: Doradidae, Auchenipteridae): Potential morphological correlates
Authors: Kaatz Ingrid M. , Stewart Donald J.
Published: February 2016

Swimbladder disturbance sounds of doradoid catfishes (Doradidae and Auchenipteridae) demonstrated striking waveform and spectrographic variation. We surveyed sounds of 25 doradoid species in 20 genera comparing these to sounds of four vocal outgroup catfish families. Sounds were either continuous waveforms (lacking interpulses) or pulsed (groups of pulses repeated at fixed temporal intervals). This is the first evidence for swimbladder calls with fixed interpulse patterns in catfishes. Vocal mechanism components that were similar between doradids and auchenipterids included: swimbladder shape, swimbladder dimensions and sonic muscle-somatic index. Morphological traits that showed variation among taxa and were evaluated for potential correlates of call diversity are: 1) diverticula (marginal outpocketings of the swimbladder with no connection to inner ear) and 2) elastic spring apparatus Müllerian rami (ESA-Mr). Within the doradid subfamilies and within the Auchenipteridae most species differed significantly in dominant frequency with frequency ranges overlapping to some extent for most. Doradid swim-bladder diverticula did not explain dominant frequency variation within the doradoid superfamily. Some doradids with conical ESA-Mr had the highest dominant frequency sounds. Auchenipterids included both relatively lower and higher dominant frequency sound producers but lacked diverticula and had discoidal ESA-Mr. Comparing a phylogeny of doradoid genera with out-group taxa, we infer that complex diverticula and conical ESA-Mr are derived characters within the Doradidae. Species representing outgroup families produced either continuous lower dominant frequency sounds (aspredinids, mochokids and pseu-dopimelodids) or pulsed higher dominant frequency sounds (pimelodids).
Coat color and its effect on preference for the scent marks of opposite-sex conspecifics in the meadow vole Microtus pennsylvanicus
Authors: Vaughn Ashlee A. , Finger Antedra A. , Gibbs Porshia E. , Ferkin Michael H.
Published: February 2016

Many mammal species can distinguish between opposite-sex conspecifics that differ in a certain trait. In that coat coloration is associated with differences in physiological and behavioral traits, coat color may affect the attractiveness of odor cues produced by conspecifics. Individuals may be able to respond preferentially to conspecifics with a particular coat color. In the present study, we test the hypothesis that scent marks of brown and blond voles differ in their attractiveness to male and female conspecifics. Male voles and brown females did not discriminate between blond- and brown-coated opposite-sex conspecifics suggesting that they are neither selecting potential mates dissociatively nor associatively. However, blond females behaved as if the scent marks of blond males were more attractive than were the scent marks of brown males. Our data suggest that blond females who are already conspicuous to predators, may select blond males as mates because they do not appreciably increase the risk of detection to predators, particularly avian predators. Moreover, because these conspicuous males have survived to mate they may have good genes that reflect their relatively higher quality [Current Zoology 58 (2): 221–227 , 2012].
Discriminative predation: Simultaneous and sequential encounter experiments
Authors: Beatty C. D. , Franks D. W.
Published: February 2016

There are many situations in which the ability of animals to distinguish between two similar looking objects can have significant selective consequences. For example, the objects that require discrimination may be edible versus defended prey, predators versus non-predators, or mates of varying quality. Working from the premise that there are situations in which discrimination may be more or less successful, we hypothesized that individuals find it more difficult to distinguish between stimuli when they encounter them sequentially rather than simultaneously. Our study has wide biological and psychological implications from the perspective of signal perception, signal evolution, and discrimination, and could apply to any system where individuals are making relative judgments or choices between two or more stimuli or signals. While this is a general principle that might seem intuitive, it has not been experimentally tested in this context, and is often not considered in the design of models or experiments, or in the interpretation of a wide range of studies. Our study is different from previous studies in psychology in that a) the level of similarity of stimuli are gradually varied to obtain selection gradients, and b) we discuss the implications of our study for specific areas in ecology, such as the level of perfection of mimicry in predator-prey systems. Our experiments provide evidence that it is indeed more difficult to distinguish between stimuli – and to learn to distinguish between stimuli – when they are encountered sequentially rather than simultaneously, even if the intervening time interval is short.
The reliability of morphometric discriminant functions in determining the sex of Chilean flamingos Phoenicopterus chilensis
Authors: Montalti Diego , Graña Grilli Maricel , Maragliano René E. , Cassini Guillermo
Published: February 2016

Monomorphic birds cannot be sexed visually and discriminant functions on the basis of external morphological variations are frequently used. Our objective was to evaluate the reliability of sex classification functions created from structural measurements of Chilean flamingos Phoenicopterus chilensis museum skins for the gender assignment of live birds. Five measurements were used to develop four discriminant functions: culmen, bill height and width, tarsus length and middle toe claw. The functions were tested on a sample of live flamingos from a zoo. The best classification for museum flamingos was given by a function using tarsus length, bill width and middle toe claw (97%). However, this function did not give the best classification for the zoo-based flamingos (81%) which had the best sex assignment by a function including measurements of tarsus, culmen and bill height and width (85%). This shows that a function giving good results in the sample from which it originated may not be as good when applied to another group of animals. Our study emphasizes the need for assessing the accuracy of a function by testing it with other methods to ensure its suitability when being applied.
The effects of cues from kingsnakes on the reproductive effort of house mice
Authors: Starke W. Wallace , Ferkin Michael H.
Published: February 2016

It is not clear if rodents express inducible defenses in response to reptilian predators such as snakes. We tested the hypothesis that adult house mice Mus musculus decrease aspects of their reproductive effort upon 1 hour of exposure every 48 hours for a 25-day period to the fecal material and shed skins of a euryphagous ophidian predator, the kingsnake Lampropeltis getula, that had been fed mice. We found no significant differences in the total number of offspring born, the number of pups per litter, and the mean weight of pups in litters born to male and female mice that were exposed to predator cues and those mice that were not exposed to such cues. The lack of an inducible response may be associated with the low cost of an effective defense, or the lack of an effective defense against a generalist snake predator.
Speciation by selection: A framework for understanding ecology’s role in speciation
Authors: Langerhans R. Brian , Riesch Rüdiger
Published: February 2016

Speciation research during the last several decades has confirmed that natural selection frequently drives the generation of new species. But how does this process generally unfold in nature? We argue that answering this question requires a clearer conceptual framework for understanding selection’s role in speciation. We present a unified framework of speciation, providing mechanistic descriptions of fundamentally distinct routes to speciation, and how these may interact during lineage splitting. Two major categories are recognized: reproductive isolation resulting from (1) responses to selection, “speciation by selection,” or (2) non-selective processes, “speciation without selection.” Speciation by selection can occur via three mechanisms: (1) similar selection, (2) divergent selection, and (3) reinforcement selection. Understanding ecology’s role in speciation requires uncovering how these three mechanisms contribute to reproductive isolation, and their relative importance compared to non-selective processes, because all three mechanisms can occur side-by-side during speciation. To accomplish this, we highlight examination of groups of organisms inhabiting replicated environmental gradients. This scenario is common in nature, and a large literature illustrates that both parallel and non-parallel responses to similar environments are widespread, and each can result in speciation. This recognition reveals four general pathways of speciation by similar or divergent selection—parallel and nonparallel responses to similar and divergent selection. Altogether, we present a more precise framework for speciation research, draw attention to some under-recognized features of speciation, emphasize the multidimensionality of speciation, reveal limitations of some previous tests and descriptions of speciation mechanisms, and point to a number of directions for future investigation.
Self-referent phenotype matching and its role in female mate choice in arthropods
Authors: Weddle Carie B. , Hunt John , Sakaluk Scott K.
Published: February 2016

A growing body of empirical evidence shows that females of many animal species gain benefits by mating polyandrously, and often prefer to mate with novel males over previous mates. Although a female preference for novel males has been demonstrated for multiple animal taxa, the mechanisms used by females to discriminate between novel and previous mates remain largely unknown. However, recent studies suggest that in decorated crickets Gryllodes sigillatus, females actually imbue males with their own chemical cues, known as cuticular hydrocarbons (CHCs) during mating, and utilize chemosensory self-referencing to recognize recent mates. Here we review evidence that self-referent phenotype matching is a widespread mechanism of recognition in arthropods, and explore how CHCs are used to facilitate mate-choice decisions. There is substantial evidence that CHCs are used as recognition cues to discriminate between species, kin, sexes, mates, individuals, and self and non-self, and are used to facilitate mate-choice decisions in a wide range of arthropod taxa. There is also evidence that CHCs are often transferred between individuals during direct physical contact, including copulation. Chemosensory self-referencing via cuticular hydrocarbons could provide a simple, but reliable mechanism for identifying individuals from previous mating encounters. This mechanism does not require any specialized cognitive abilities because an individual’s phenotype is always available for reference. Given the ubiquitous use of CHCs among arthropods, chemosensory self-referencing may be a widespread mechanism used by female arthropods to facilitate female mate-choice decisions and to enhance opportunities for polyandry.
Felsenstein’s “one-allele model” of speciation: The role of philopatry in the initial stages of host plant mediated reproductive isolation in Enchenopa binotata
Authors: Stearns Frank W. , Tilmon Kelley J. , Wood Thomas K.
Published: February 2016

The study of speciation genetics is primarily concerned with identifying the genetic traits that allow divergent selection to overcome the homogenizing effects of gene flow. Felsenstein reviewed this race between gene flow and selection, concluding that speciation with gene flow was unlikely under a “two-allele model” (where two traits were necessary for reproductive isolation) but that divergence could occur quite easily under a “one-allele model.” Despite this finding, much of the sympatric speciation research involving phytophagous insects has relied on a two-trait model, where insects evolve both preferences for and increased performance on novel host plants. Philopatry (a tendency to remain where one was born) is known to occur in phytophagous insects and is a single trait isolation mechanism. However, it is traditionally invoked as simply augmenting reproductive isolation. Species in the Enchenopa binotata complex are believed to have speciated in sympatry. They exhibit host plant preferences, host specific performance advantages and strong philopatry. We experimentally shifted E. binotata to evolutionarily novel host plants. Previous research has demonstrated that the experimental population of insects possesses genetic variation in preference and performance to the novel host. The degree of philopatry at mating and egg-laying was assayed for the first four years under full choice conditions. Host plant preference and performance was assayed after eight years. Philopatry was an immediate and strong isolating mechanism, while preference for and performance on the novel host lagged. We therefore suggest that philopatry may be a more important mechanism in the early stages of a host shift than previously believed.
Invasive Carassius carp in Georgia: Current state of knowledge and future perspectives
Authors: Japoshvili Bella , Mumladze Levan , Küçük Fahrettin
Published: February 2016

In Georgia, crucian carp Carassius carassius (Linnaeus, 1758) was known from only one locality after Kessler’s record (1877–1878) with no new findings until 1985. Since then C. carassius rapidly and simultaneously invaded almost all water bodies of Georgia. In 2004, it was for the first time noted that this invasive Carassius sp. could not be a C. Carassius, but was a form of Carassius gibelio (Bloch, 1792). However no further data is available about this invasive species in Georgia. The aim of the present study was to investigate taxonomic status of Carassius sp. in Georgia using mtDNA phylogenetic analyses and mor-phometric study of truss network system. Genetic analysis revealed that invasive Carassius sp. is closely related to the C. gibelio from Turkey and other countries. In contrast, morphometrically Carassius sp. from Georgia can be easily differentiated from those of Turkey indicating high intraspecific variability. This is the first time discussion on the current knowledge of the present distribution of invasive carp in Georgia with identifying current problems and future research directions needed.
Habitat-dependent diversification and parallel molecular evolution: Water scavenger beetles as a case study
Authors: Song Ke-Qing , Xue Huai-Jun , Beutel Rolf G. , Bai Ming , Bian Dong-Ju , Liu Jie , Ruan Yong-Ying , Li Wen-Zhu , Jia Feng-Long , Yang Xing-Ke
Published: February 2016

Habitat shift is a key innovation that has contributed to the extreme diversification of insects. Most groups are well-adapted to more or less specific environments and shifts usually only happen between similar habitats. To colonize a profoundly different habitat type does not only present ecological opportunities but also great challenges. We used Hydrophiloidea (water scavenger beetles) as a system to study transitions between terrestrial and aquatic environments. We estimated the diversification rate of different clades using phylogenetic trees based on a representative taxon sampling and six genes. We also investigated possible evolutionary changes in candidate genes following habitat shifts. Our results suggest that the diversification rate is relatively slow (0.039?0.050 sp/My) in the aquatic lineage, whereas it is distinctly increased in the secondarily terrestrial clade (0.055?0.075 sp/My). Our results also show that aquatic species have a G (Glycine) or S (Serine) amino acid at a given site of COI, while terrestrial species share an A (Alanine) amino acid with terrestrial outgroups. This indicates that habitat factors may create selection pressure on the evolution of functional genes and cause homoplasy in molecular evolution.
Neurochemistry as a bridge between morphology and behavior: Perspectives on aggression in insects
Authors: Bubak Andrew N. , Grace Jaime L. , Watt Michael J. , Renner Kenneth J. , Swallow John G.
Published: February 2016

Aggression is a common behavioral trait shared in many animals, including both vertebrates and invertebrates. However, the type and intensity of agonistic encounters and displays can vary widely both across and within species, resulting in complicated or subjective interpretations that create difficulties in developing theoretical models that can be widely applied. The need to easily and objectively identify quantifiable behaviors and their associated morphologies becomes especially important when attempting to decipher the neurological mechanisms underlying this complex behavior. Monoamines, neuropeptides, and pheromones have been implicated as important neuromodulators for agonistic displays in both invertebrates and vertebrates. Additionally, recent breakthroughs in insect research have revealed exciting proximate mechanisms important in aggression that may be broadly relevant, due to the relatively high conservation of these neurochemical systems across animal taxa. In this review, we present the latest research demonstrating the importance of monoamines, neuropeptides, and pheromones as neuromodulators for aggression across a variety of insect species. Additionally, we describe the stalk-eyed fly as a model system for studying aggression, which integrates physiological, morphological, and neurochemical approaches in exploring detailed mechanisms responsible for this common yet complex behavior. We conclude with our perspective on the most promising lines of future research aimed at understanding the proximate and ultimate mechanisms underlying aggressive behaviors.
Interactions between background matching and disruptive colouration: Experiments using human predators and virtual crabs
Authors: Todd Peter A. , Phua Huijia , Toh Kok Ben
Published: February 2016

Interactions between disruptive colouration and the match between prey and background spot size were manipulated in two experiments that used time taken by human ‘predators’ to find artificial prey (virtual crab morphs) against heterogeneous backgrounds as a measure of the their camouflage. Experiment 1, in which the spots and their placement imitated the arrangement on the crab Carcinus maenas, tested whether high and low contrast spots touching the body outline (disruptive ‘edge’ morphs) made the artificial prey more difficult to detect than when the spots did not touch the outline (non-disruptive ‘inner’ morphs) against three different backgrounds: ‘small’, ‘middle’ and ‘large’ spot size. In Experiment 2, the range of spot sizes and their positions (‘edge’ and ‘inner’) on the crab morphs were varied to determine the most effective combination against the ‘middle’ background. Altogether, 640 volunteers participated in these computer trials, representing a high degree of independent replication. All patterned morphs were significantly harder to detect than plain morphs, indicating that possessing at least some degree of background matching can provide camouflage. Both experiments demonstrated that various morphs, though not having the same spot sizes as the background, had similar or better survivorship as those with matching spot sizes—indicating that optimal camouflage did not come from background matching alone. In Experiment 2, edge-disrupted morphs consistently took longer to find than their non-disruptive counterparts. The relative effects of edge disruption, contrast, and background/prey spot size are clearly context-dependent, highlighting the complexity of prey concealment.
Genetic diversification in the East Himalayas as revealed by comparative phylogeography of the black-throated bushtit and Elliot’s laughing thrush
Authors: Quan Qing , Qu Yanhua , Lei Fumin
Published: February 2016

The Southwest Mountainous region of the eastern Himalayas is a hotspot with extraordinarily high biodiversity and endemism, but the processes that have driven this unique diversity are largely unknown. We evaluated processes that have contributed to the current observed high genetic diversity in this region by integrating comparative phylogeography with ecological niche modeling in a study of two representative birds of the Southwest Mountains: the black-throated bushtit Aegithalos concinnus and the Elliot’s laughing thrush Garrulax elliotii. Mitochondrial DNA analyses revealed multiple divergent genetic lineages, which are roughly congruent with the north, south and east eco-subregion division of the Southwest Mountains. This strong geographical structure in these two species suggests that lineage diversification has proceeded in situ between the eco-subregions of the Southwest Mountains. During Pleistocene glaciations, the two species responded differently to climatic fluctuations. A. con-cinnus maintained rather stable habitats, mostly evergreen forests, during glacial cycles and thus kept a stable population size and further accumulated genetic diversity. In contrast, G. elliotii, which is mostly active in shrublands, has shifted its suitable habitats with glacial cycles. This species dispersed to low elevation areas during glacial periods, which provided multiple opportunities for gene admixture. The admixture causes the mixing of previously isolated genetic lineages and thus obscures the pattern of genetic variation.
Fruit fly courtship: The female perspective
Authors: Dukas Reuven , Scott Andrew
Published: February 2016

Research on fruit fly courtship has mostly focused on males’ behavioral repertoire whereas females have been assumed to respond by either rejecting or accepting males. In many fruit fly species including Drosophila melanogaster, however, mating typically follows an extended period of courtship, which provides ample opportunities for females to inform males about their likelihood of mating. Our experiments indeed revealed that sexually immature females in both D. melanogasterand D. simulans showed responses to conspecific males that were distinct from those of sexually mature females. Furthermore, females’ responses to conspecific males were different from their responses to heterospecific males. Our data indicate that females’ behavioral repertoire early in courtship can inform males about their probability of mating if they persist in courting. We hypothesize (i) that males can rely on behavioral feedback from females for optimally allocating their courtship efforts towards distinct female classes, (ii) that males may learn to modulate their courtship behavior based on specific feedback from females, and (iii) that females may learn to alter their behavior towards distinct types of males in order to elicit the desired male response. Overall, we suggest that, although little explored, female behavior determines the dynamics of courtship and mating and can thus influence sexual selection and incipient speciation.
The effect of learning on the evolution of new courtship behavior: A simulation model
Authors: Morier-Genoud Rémy , Kawecki Tadeusz J.
Published: February 2016

The fact that individuals learn can change the relationship between genotype and phenotype in the population, and thus affect the evolutionary response to selection. Here we ask how male ability to learn from female response affects the evolution of a novel male behavioral courtship trait under pre-existing female preference (sensory drive). We assume a courtship trait which has both a genetic and a learned component, and a two-level female response to males. With individual-based simulations we show that, under this scenario, learning generally increases the strength of selection on the genetic component of the courtship trait, at least when the population genetic mean is still low. As a consequence, learning not only accelerates the evolution of the courtship trait, but also enables it when the trait is costly, which in the absence of learning results in an adaptive valley. Furthermore, learning can enable the evolution of the novel trait in the face of gene flow mediated by immigration of males that show superior attractiveness to females based on another, non-heritable trait. However, rather than increasing monotonically with the speed of learning, the effect of learning on evolution is maximized at intermediate learning rates. This model shows that, at least under some scenarios, the ability to learn can drive the evolution of mating behaviors through a process equivalent to Waddington’s genetic assimilation.
Short-term Outcomes for Medicare Beneficiaries After Low-acuity Visits to Emergency Departments and Clinics
Authors: Niedzwiecki Matthew , Baicker Katherine , Wilson Michael , Cutler David M. , Obermeyer Ziad
Published: February 2016

Background:

There is substantial interest in identifying low-acuity visits to emergency departments (EDs) that could be treated more appropriately in other settings. Systematic differences in illness severity between ED patients and comparable patients elsewhere could make such strategies unsafe, but little evidence exists to guide policy makers.

Objective:

To compare illness severity between patients visiting EDs and outpatient clinics, by comparing short-term mortality and hospitalization, controlling for patient demographics, comorbidity, and visit acuity.

Research Design:

Cross-sectional study of outcomes after medical encounters.

Subjects:

Nationally representative 20% sample of Medicare fee-for-service beneficiaries discharged home from ED or clinic visit in 2011, and enrolled continuously for 1 year before the visit.

Measures:

All-cause mortality and hospitalization in the 8, 15, and 30 days after discharge home from ED or clinic visits.

Results:

After risk-adjusting for patient demographic, comorbidity, disability, and dual-eligibility status, as well as visit acuity as measured by a commonly used algorithm, we found that ED patients were more likely to die (risk-adjusted odds ratio=2.75; 95% confidence interval, 2.56–2.96) or be hospitalized (odds ratio=1.97; 95% confidence interval, 1.95–2.00) after discharge than clinic patients. Differences in short-term outcomes were observed even when comparing patients with the same discharge diagnoses after risk adjustment.

Conclusions:

Patients presenting to EDs have worse risk-adjusted short-term outcomes than those presenting to outpatient clinics, even after controlling for acuity level of visit or discharge diagnosis. Existing measures of acuity using administrative data may not adequately capture severity of illness, making judgments of the appropriate setting for care difficult.
Privacy-preserving, user-centric VoIP CAPTCHA challenges
Authors: Tasidou Aimilia , Efraimidis Pavlos S. , Soupionis Yannis , Mitrou Lilian , Katos Vasilios
Published: February 2016

Purpose

– This work aims to argue that it is possible to address discrimination issues that naturally arise in contemporary audio CAPTCHA challenges and potentially enhance the effectiveness of audio CAPTCHA systems by adapting the challenges to the user characteristics.

Design/methodology/approach

– A prototype has been designed, called PrivCAPTCHA, to offer privacy-preserving, user-centric CAPTCHA challenges. Anonymous credential proofs are integrated into the Session Initiation Protocol (SIP) protocol and the approach is evaluated in a real-world Voice over Internet Protocol (VoIP) environment.

Findings

– The results of this work indicate that it is possible to create VoIP CAPTCHA services offering privacy-preserving, user-centric challenges while maintaining sufficient efficiency.

Research limitations/implications

– The proposed approach was evaluated through an experimental implementation to demonstrate its feasibility. Additional features, such as appropriate user interfaces and efficiency optimisations, would be useful for a commercial product. Security measures to protect the system from attacks against the SIP protocol would be useful to counteract the effects of the introduced overhead. Future research could investigate the use of this approach on non-audio CAPTCHA services.

Practical implications

– PrivCAPTCHA is expected to achieve fairer, non-discriminating CAPTCHA services while protecting the user’s privacy. Adoption success relies upon the general need for employment of privacy-preserving practices in electronic interactions.

Social implications

– This approach is expected to enhance the quality of life of users, who will now receive CAPTCHA challenges closer to their characteristics. This applies especially to users with disabilities. Additionally, as a privacy-preserving service, this approach is expected to increase trust during the use of services that use it.

Originality/value

– To the best of authors’ knowledge, this is the first comprehensive proposal for privacy-preserving CAPTCHA challenge adaptation. The proposed system aims at providing an improved CAPTCHA service that is more appropriate for and trusted by human users.
An integrated model of corporate brand experience and customer value co-creation behaviour
Authors: Shamim Amjad , Ghazali Zulkipli , Albinsson Pia A.
Published: February 2016

Purpose

– The purpose of this paper is to investigate the influence of corporate brand experience (CBE) on customer value co-creation attitude and behaviour (CVCCA and CVCCB). By integrating congruity theory with the theory of reasoned action, the study proposes an integrated model for developing CVCCB in a retailing context.

Design/methodology/approach

– Structural Equation Modelling, using AMOS software was conducted using a sample of 711 respondents from four hypermarkets located in five Malaysian states.

Findings

– The research findings indicate that CBE plays a significant role for developing customer attitude and behaviour of value co-creation activities. Results show that CBE has a strong positive influence on CVCCA and subjective norms (SN) which further lead to CVCCB. SN were found to be a partial mediator between CBE and CVCCA. CVCCA was found to be a partial mediator between SN and CVCCB. Full mediation of CVCCA and SN between CBE and CVCCB is confirmed.

Originality/value

– The research contributes to value co-creation literature by proposing an integrated model for developing CVCCB in retailing. This research opens avenues for future research to consider the importance of brand experiences in value co-creation practices.