Mapping Individual Variation in Male Mating Preference Space: Multiple Choice in a Color Polymorphic Cichlid Fish

Sexual selection theory largely rests on the assumption that populations contain individual variation in mating preferences and that individuals are consistent in their preferences. However, there are few empirical studies of within-population variation and even fewer have examined individual male mating preferences. Here, we studied a color polymorphic population of the Lake Victoria cichlid fish Neochromis omnicaeruleus, a species in which color morphs are associated with different sex-determining factors. Wild-caught males were tested in three-way choice trials with multiple combinations of different females belonging to the three color morphs. Compositional log-ratio techniques were applied to analyze individual male mating preferences. Large individual variation in consistency, strength, and direction of male mating preferences for female color morphs was found and hierarchical clustering of the compositional data revealed the presence of four distinct preference groups corresponding to the three color morphs in addition to a no-preference class. Consistency of individual male mating preferences was higher in males with strongest preferences. We discuss the implications of these findings for our understanding of the mechanisms underlying polymorphism in mating preferences.

Tariff-Specific Preferences and Their Influence on Price Sensitivity

For many services, consumers can choose among a range of optional tariffs that differ in their access and usage prices. Recent studies indicate that tariff-specific preferences may lead consumers to choose a tariff that does not minimize their expected billing rate. This study analyzes how tariff-specific preferences influence the responsiveness of consumers’ usage and tariff choice to changes in price. We show that consumer heterogeneity in tariff-specific preferences leads to heterogeneity in their sensitivity to price changes. Specifically, consumers with tariff-specific preferences are less sensitive to price increases of their preferred tariff than other consumers. Our results provide an additional reason why firms should offer multiple tariffs rather than a uniform nonlinear pricing plan to extract maximum consumer surplus.

Global change revealed by palaeolimnological records from remote lakes: a review

Over recent decades, palaeolimnological records from remote sites have provided convincing evidence for the onset and development of several facets of global environmental change. Remote lakes, defined here as those occurring in high latitude or high altitude regions, have the advantage of not being overprinted by local anthropogenic processes. As such, many of these sites record broad-scale environmental changes, frequently driven by regime shifts in the Earth system. Here, we review a selection of studies from North America and Europe and discuss their broader implications. The history of investigation has evolved synchronously with the scope and awareness of environmental problems. An initial focus on acid deposition switched to metal and other types of pollutants, then climate change and eventually to atmospheric deposition-fertilising effects. However, none of these topics is independent of the other, and all of them affect ecosystem function and biodiversity in profound ways. Currently, remote lake palaeolimnology is developing unique datasets for each region investigated that benchmark current trends with respect to past, purely natural variability in lake systems. Fostering conceptual and methodological bridges with other environmental disciplines will upturn contribution of remote lake palaeolimnology in solving existing and emerging questions in global change science and planetary stewardship.

Unique mixed phenotype and unexpected functional effect revealed by novel compound heterozygosity mutations involving SCN5A.

BACKGROUND Functional characterization of mutations involving the SCN5A-encoded cardiac sodium channel has established the pathogenic mechanisms for type 3 long QT syndrome and type 1 Brugada syndrome and has provided key insights into the physiological importance of essential structure-function domains. OBJECTIVE This study sought to present the clinical and biophysical phenotypes discerned from compound heterozygosity mutations in SCN5A on different alleles in a toddler diagnosed with QT prolongation and fever-induced ventricular arrhythmias. METHODS A 22-month-old boy presented emergently with fever and refractory ventricular tachycardia. Despite restoration of sinus rhythm, the infant sustained profound neurological injury and died. Using polymerase chain reaction, denaturing high-performance liquid chromatography, and direct DNA sequencing, comprehensive open-reading frame/splice mutational analysis of the 12 known long QT syndrome susceptibility genes was performed. RESULTS The infant had 2 SCN5A mutations: a maternally inherited N-terminal frame shift/deletion (R34fs/60) and a paternally inherited missense mutation, R1195H. The mutations were engineered by site-directed mutagenesis and heterologously expressed transiently in HEK293 cells. As expected, the frame-shifted and prematurely truncated peptide, SCN5A-R34fs/60, showed no current. SCN5A-R1195H had normal peak and late current but abnormal voltage-dependent gating parameters. Surprisingly, co-expression of SCN5A-R34fs/60 with SCN5A-R1195H elicited a significant increase in late sodium current, whereas co-expression of SCN5A-WT with SCN5A-R34fs/60 did not. CONCLUSIONS A severe clinical phenotype characterized by fever-induced monomorphic ventricular tachycardia and QT interval prolongation emerged in a toddler with compound heterozygosity involving SCN5A: R34fs/60, and R1195H. Unexpectedly, the 94-amino-acid fusion peptide derived from the R34fs/60 mutation accentuated the late sodium current of R1195H-containing Na(V)1.5 channels in vitro.

Indirectly measuring evaluations of several attitude objects in relation to a neutral reference point

This article presents a new response time measure of evaluations, the Evaluative Movement Assessment (EMA). Two properties are verified for the first time in a response time measure: (a) mapping of multiple attitude objects to a single scale, and (b) centering that scale around a neutral point. Property (a) has implications when self-report and response time measures of attitudes have a low correlation. A study using EMA as an indirect measure revealed a low correlation with self-reported attitudes when the correlation reflected between-subjects differences in preferences for one attitude object to a second. Previously this result may have been interpreted as dissociation between two measures. However, when correlations from the same data reflected within-subject preference rank orders between multiple attitude objects, they were substantial (average r = .64). This result suggests that the presence of low correlations between self-report and response time measures in previous studies may be a reflection of methodological aspects of the response time measurement techniques. Property (b) has implications for exploring theoretical questions that require assessment of whether an evaluation is positive or negative (e.g., prejudice), because it allows such classifications in response time measurement to be made for the first time.

Habitat selection of three cryptic Plecotus bat species in the European Alps reveals contrasting implications for conservation

Assessing the ecological requirements of species coexisting within a community is an essential requisite for developing sound conservation action. A particularly interesting question is what mechanisms govern the stable coexistence of cryptic species within a community, i.e. species that are almost impossible to distinguish. Resource partitioning theory predicts that cryptic species, like other sympatric taxa, will occupy distinct ecological niches. This prediction is widely inferred from eco-morphological studies. A new cryptic long-eared bat species, Plecotus macrobullaris, has been recently discovered in the complex of two other species present in the European Alps, with even evidence for a few mixed colonies. This discovery poses challenges to bat ecologists concerned with planning conservation measures beyond roost protection. We therefore tested whether foraging habitat segregation occurred among the three cryptic Plecotus bat species in Switzerland by radiotracking 24 breeding female bats (8 of each species). We compared habitat features at locations visited by a bat versus random locations within individual home ranges, applying mixed effects logistic regression. Distinct, species-specific habitat preferences were revealed. P. auritus foraged mostly within traditional orchards in roost vicinity, with a marked preference for habitat heterogeneity. P. austriacus foraged up to 4.7 km from the roost, selecting mostly fruit tree plantations, hedges and tree lines. P. macrobullaris preferred patchy deciduous and mixed forests with high vertical heterogeneity in a grassland dominated-matrix. These species-specific habitat preferences should inform future conservation programmes. They highlight the possible need of distinct conservation measures for species that look very much alike.

Learner preferences regarding integrating, sequencing and aligning virtual patients with other activities in the undergraduate medical curriculum: A focus group study

CONTEXT: E-learning resources, such as virtual patients (VPs), can be more effective when they are integrated in the curriculum. To gain insights that can inform guidelines for the curricular integration of VPs, we explored students' perceptions of scenarios with integrated and non-integrated VPs aimed at promoting clinical reasoning skills. METHODS: During their paediatric clerkship, 116 fifth-year medical students were given at least ten VPs embedded in eight integrated scenarios and as non-integrated add-ons. The scenarios differed in the sequencing and alignment of VPs and related educational activities, tutor involvement, number of VPs, relevance to assessment and involvement of real patients. We sought students' perceptions on the VP scenarios in focus group interviews with eight groups of 4-7 randomly selected students (n = 39). The interviews were recorded, transcribed and analysed qualitatively. RESULTS: The analysis resulted in six themes reflecting students' perceptions of important features for effective curricular integration of VPs: (i) continuous and stable online access, (ii) increasing complexity, adapted to students' knowledge, (iii) VP-related workload offset by elimination of other activities, (iv) optimal sequencing (e.g.: lecture--1 to 2 VP(s)--tutor-led small group discussion--real patient) and (V) optimal alignment of VPs and educational activities, (vi) inclusion of VP topics in assessment. CONCLUSIONS: The themes appear to offer starting points for the development of a framework to guide the curricular integration of VPs. Their impact needs to be confirmed by studies using quantitative controlled designs.

Time-variable gravity signal in Greenland revealed by high-low satellite-to-satellite tracking

[1] In the event of a termination of the Gravity Recovery and Climate Experiment (GRACE) mission before the launch of GRACE Follow-On (due for launch in 2017), high-low satellite-to-satellite tracking (hl-SST) will be the only dedicated observing system with global coverage available to measure the time-variable gravity field (TVG) on a monthly or even shorter time scale. Until recently, hl-SST TVG observations were of poor quality and hardly improved the performance of Satellite Laser Ranging observations. To date, they have been of only very limited usefulness to geophysical or environmental investigations. In this paper, we apply a thorough reprocessing strategy and a dedicated Kalman filter to Challenging Minisatellite Payload (CHAMP) data to demonstrate that it is possible to derive the very long-wavelength TVG features down to spatial scales of approximately 2000 km at the annual frequency and for multi-year trends. The results are validated against GRACE data and surface height changes from long-term GPS ground stations in Greenland. We find that the quality of the CHAMP solutions is sufficient to derive long-term trends and annual amplitudes of mass change over Greenland. We conclude that hl-SST is a viable source of information for TVG and can serve to some extent to bridge a possible gap between the end-of-life of GRACE and the availability of GRACE Follow-On.

Time Preferences and Environmental Concern: An Analysis of the Swiss ISSP 2010

This study analyzes the trend of environmental concern in Switzerland using data from the International Social Survey Program (ISSP) 1993, 2000, and 2010. First, we compare the observed trend with indicators of the intensity of public debate regarding the environment. The results show that both the number of articles dealing with environmental issues in print newspapers and the debates in the Swiss parliament strongly increased during the observed period. The ecological awareness of the population, however, remained constant over this time. Second, we scrutinize the "social basis" of environmental concern paying particular attention to individuals' time preferences. Third, we investigate the relationship between environmental concern and proenvironmental behavior, on the one hand, and the relation of concern and the acceptance of governmental regulations, on the other hand.

The onset of Neoglaciation 6000 years ago in western Mongolia revealed by an ice core from the Tsambagarav mountain range

Glacier highstands since the Last Glacial Maximum are well documented for many regions, but little is known about glacier fluctuations and lowstands during the Holocene. This is because the traces of minimum extents are difficult to identify and at many places are still ice covered, limiting the access to sample material. Here we report a new approach to assess minimal glacier extent, using a 72-m long surface-to-bedrock ice core drilled on Khukh Nuru Uul, a glacier in the Tsambagarav mountain range of the Mongolian Altai (4130 m asl, 48°39.338′N, 90°50.826′E). The small ice cap has low ice temperatures and flat bedrock topography at the drill site. This indicates minimal lateral glacier flow and thereby preserved climate signals. The upper two-thirds of the ice core contain 200 years of climate information with annual resolution, whereas the lower third is subject to strong thinning of the annual layers with a basal ice age of approximately 6000 years before present (BP). We interpret the basal ice age as indicative of ice-free conditions in the Tsambagarav mountain range at 4100 m asl prior to 6000 years BP. This age marks the onset of the Neoglaciation and the end of the Holocene Climate Optimum. The ice-free conditions allow for adjusting the Equilibrium Line Altitude (ELA) and derive the glacier extent in the Mongolian Altai during the Holocene Climate Optimum. Based on the ELA-shift, we conclude that most of the glaciers are not remnants of the Last Glacial Maximum but were formed during the second part of the Holocene. The ice core derived accumulation reconstruction suggests important changes in the precipitation pattern over the last 6000 years. During formation of the glacier, more humid conditions than presently prevailed followed by a long dry period from 5000 years BP until 250 years ago. Present conditions are more humid than during the past millennia. This is consistent with precipitation evolution derived from lake sediment studies in the Altai.

The structure of the asteroid 4 Vesta as revealed by models of planet-scale collisions

Asteroid 4Vesta seems to be a major intact protoplanet, with a surface composition similar to that of the HED (howardite-eucrite-diogenite) meteorites. The southern hemisphere is dominated by a giant impact scar, but previous impact models have failed to reproduce the observed topography. The recent discovery that Vesta's southern hemisphere is dominated by two overlapping basins provides an opportunity to model Vesta's topography more accurately. Here we report three-dimensional simulations of Vesta's global evolution under two overlapping planet-scale collisions. We closely reproduce its observed shape, and provide maps of impact excavation and ejecta deposition. Spiral patterns observed in the younger basin Rheasilvia, about one billion years old, are attributed to Coriolis forces during crater collapse. Surface materials exposed in the north come from a depth of about 20kilometres, according to our models, whereas materials exposed inside the southern double-excavation come from depths of about 60-100kilometres. If Vesta began as a layered, completely differentiated protoplanet, then our model predicts large areas of pure diogenites and olivine-rich rocks. These are not seen, possibly implying that the outer 100kilometres or so of Vesta is composed mainly of a basaltic crust (eucrites) with ultramafic intrusions (diogenites).

Publication trade-offs for junior scholars in IS: conjoint analysis of preferences for quality, first authorship, collaboration and time

A publication record provides evidence of research productivity and is critical for junior scholars starting their careers in academia. Publication attributes, such as level of the publication outlet, order and number of authors, are typically used to evaluate its quality. However, time spent on a publication is a limited commodity, and researchers face significant trade-offs when deciding which publications they should concentrate on. To better understand the choices made, conjoint analysis with 241 junior IS scholars was conducted. We find that when “quality vs. number of authors” and “quality vs. time” trade-offs are considered, quality is prioritized. However, the emphasis on quality is less pronounced when “rank as an author” is at stake. Especially Ph.D. students tend to choose first authorship when dealing with “quality vs. rank as an author” trade-off. Our findings provide intriguing insights into how publication attributes weigh against each other when research collaboration decisions are made.

Intact flagellar motor of Borrelia burgdorferi revealed by cryo-electron tomography: evidence for stator ring curvature and rotor/C-ring assembly flexion.

The bacterial flagellar motor is a remarkable nanomachine that provides motility through flagellar rotation. Prior structural studies have revealed the stunning complexity of the purified rotor and C-ring assemblies from flagellar motors. In this study, we used high-throughput cryo-electron tomography and image analysis of intact Borrelia burgdorferi to produce a three-dimensional (3-D) model of the in situ flagellar motor without imposing rotational symmetry. Structural details of B. burgdorferi, including a layer of outer surface proteins, were clearly visible in the resulting 3-D reconstructions. By averaging the 3-D images of approximately 1,280 flagellar motors, a approximately 3.5-nm-resolution model of the stator and rotor structures was obtained. flgI transposon mutants lacked a torus-shaped structure attached to the flagellar rod, establishing the structural location of the spirochetal P ring. Treatment of intact organisms with the nonionic detergent NP-40 resulted in dissolution of the outermost portion of the motor structure and the C ring, providing insight into the in situ arrangement of the stator and rotor structures. Structural elements associated with the stator followed the curvature of the cytoplasmic membrane. The rotor and the C ring also exhibited angular flexion, resulting in a slight narrowing of both structures in the direction perpendicular to the cell axis. These results indicate an inherent flexibility in the rotor-stator interaction. The FliG switching and energizing component likely provides much of the flexibility needed to maintain the interaction between the curved stator and the relatively symmetrical rotor/C-ring assembly during flagellar rotation.