Natural Asymmetry Research Articles

Problems and challenges of development of Ukraine: investment and personnel aspect

In the conceptual and methodological sense, the article considers war as a force majeure factor, the action of which has multifaceted negative consequences in the form of increasing risks of physical destruction of human and material resources, deterioration of their quality parameters, in particular, the mental and physical state of health of the population. The magnitude and scope of the loss of national wealth as a result of the full-scale war of the Russian Federation against Ukraine deepened the previously formed contradictions and asymmetries of a diverse nature in the economic system of our country. Socio-economic consequences are manifested in large-scale emigration, the appearance of forcibly displaced persons, a shortage of qualified labor, an asymmetry between demand and its supply in the domestic labor market, and a decrease in the number of jobs. Restoration of life-supporting objects of national wealth is considered as an objective prerequisite for the existence and victory of our state in this war. The article substantiates the leading role of state regulation in recovery by using a set of forms and methods of centralized influence on its organization and planning, presents the principles of participation of international partners in it. In the context of the leading role of the regulatory influence of the state on the reconstruction processes of Ukraine, the need for a systematic approach to solving the tactical and strategic tasks of restoring the economic potential of our country is substantiated. When developing and choosing a model for its restoration, priority should be given to the economic interests of domestic investors, employers, and workers. It was determined that its implementation allows to ensure the achievement of multifaceted positive results in the reconstruction of the economy of Ukraine. Objectively necessary prerequisites for the latter are the management of modernization processes by representatives of Ukrainian entrepreneurship, whose activities are based on the principles and principles of corporate social responsibility of business. In the conditions of war, this involves ensuring the functioning and development of enterprises located in the territory controlled by our state, employment of forcibly displaced persons, improvement of their welfare, compliance with laws and payment of all taxes, establishment of public-private partnership between socially responsible business and state institutions. Investing in rebuilding the economic potential of Ukraine is considered an objective phenomenon that is under the influence of state regulatory levers, the use of which is aimed at creating a favorable investment climate in the country. The negative impact on its state due to the lack of effective taxation, imperfection of land legislation, irrationality of the banking system, the absence of a national state credit investment company functionally aimed at identifying investment priorities with their technical and economic justification, control over the provision of benefits, the annexation of Crimea, the occupation of parts of the eastern oblasts and the conduct of military operations there, shelling of populated areas, which increases the likelihood of investment risks.

Mechanistic Insights into Curvature Formation in Synthetic Vesicles.

The mimicking of natural lipid bilayers with synthetic amphiphilic systems is of great interest to researchers, as insights could lead to better understanding of the complexities of cell membranes, as well as new materials and healthcare technologies. Recapitulating natural lipid asymmetry across bilayer membranes has important implications for curvature in cell, vesicle, and organelle morphologies, but has been challenging to achieve with synthetic lipid combinations or standard amphiphilic block copolymers. In a recent article, Elizebath et al. report the synthesis of a new type of synthetic amphiphile able to induce asymmetry in an artificial bilayer membrane dynamically. The molecules were designed around an extended π-conjugated hydrophobic core with tertiary amine-terminated oxyalkylene side chains. Protonation of the tertiary amines on the bilayer exterior leads to curvature induction, bilayer fission, and vesicle formation as monitored by time-resolved spectroscopy techniques and microscopy. The results were further validated with density functional theory (DFT) calculations. The delicate balance between different molecular scale interactions in the supramolecular structures led to the dynamic transformation of the bilayer membranes. Insights described could be used to advance the assembly of hierarchical life-like materials.

Mechanistic Insights into Curvature Formation in Synthetic Vesicles

AbstractThe mimicking of natural lipid bilayers with synthetic amphiphilic systems is of great interest to researchers, as insights could lead to better understanding of the complexities of cell membranes, as well as new materials and healthcare technologies. Recapitulating natural lipid asymmetry across bilayer membranes has important implications for curvature in cell, vesicle, and organelle morphologies, but has been challenging to achieve with synthetic lipid combinations or standard amphiphilic block copolymers. In a recent article, Elizebath et al. report the synthesis of a new type of synthetic amphiphile able to induce asymmetry in an artificial bilayer membrane dynamically. The molecules were designed around an extended π‐conjugated hydrophobic core with tertiary amine‐terminated oxyalkylene side chains. Protonation of the tertiary amines on the bilayer exterior leads to curvature induction, bilayer fission, and vesicle formation as monitored by time‐resolved spectroscopy techniques and microscopy. The results were further validated with density functional theory (DFT) calculations. The delicate balance between different molecular scale interactions in the supramolecular structures led to the dynamic transformation of the bilayer membranes. Insights described could be used to advance the assembly of hierarchical life‐like materials.

Normal Facial Function in the Sunnybrook Facial Grading System: Is the 100% Score too Restrictive?

The primary objective of this study was to describe the distribution of the Sunnybrook Facial Grading System scores in the general population. Secondary objectives included analyzing the effects of age, gender and facial side on these scores. Two speech therapists specializing in facial motor skill assessment evaluated the healthy participants using the Sunnybrook Facial Grading System, first with the right hemiface as a reference and then with the left hemiface as a reference. The study was conducted in our ENT department from September 2022 to June 2023. One hundred eleven healthy participants were included (57 women and 54 men), aged 18 to 79 years. SFGS composite scores (SFGS-Total) and sub-scores at rest (SFGS-Rest) and in movement (SFGS-Movement) were studied according to three age categories (18-39 years) (40-59 years) and (60-79 years) and gender. Inter-rater reliability was collected between the two evaluators with Cronbach's alpha. Taking the right hemiface as a reference, SFGS-Total scores ranged from 65% to 100% (median = 96, IQR [91-100]). When the left hemiface was considered as the reference, scores ranged from 78% to 100% (median = 95; IQR [90-100]). Right and left SFGS-Total scores showed high inter-rater reliability (respectively α = 0.953 and α = 0.926). There was a slight negative correlation between age and SFGS-Total scores. By embracing a more realistic approach that acknowledges natural variations and asymmetry in facial movements, we can enhance patient care and promote a more holistic understanding of facial rehabilitation outcomes.

The effect of pH on the structure of Bluetongue virus VP5.

The unenveloped Bluetongue virus capsid comprises several structural layers, the inner two comprising a core, which assembles before addition of the outer proteins, VP2 and VP5. Two symmetric trimers of VP5 fit like pegs into two distinct pits on the core and undergo pH conformational changes in the context of the virus, associated with cell entry. Here we show that in isolation VP5 alone undergoes essentially the same changes with pH and confirm a helical transition, indicating that VP5 is a motor during cell entry. In the absence of VP5 the two pits on the core differ from each other, presumably due to the asymmetric underlying structure of VP3, the innermost capsid protein. On insertion of VP5 these pits become closely similar and remain similar at low pH whilst VP5 is present. This natural asymmetry presumably destabilises the attachment of VP5, facilitating ejection upon low pH, membrane penetration and cell entry.

Cross-Sectional Study on Self-Perception of Dento-Facial Asymmetry.

Background and Objectives: Facial symmetry is a key component of facial beauty and attractiveness. However, perfect symmetry is rare, and slight asymmetries, also known as natural asymmetries, are common and contribute to the uniqueness of each face. The perception of facial asymmetry varies among individuals and can be influenced by several factors. This study aimed to investigate the self-perception of dento-facial asymmetry among a sample of Romanian individuals, focusing on their awareness, the extent to which it bothers them, and their desire for correction. Materials and Methods: A cross-sectional analytical study was conducted with 283 participants from Romania between January and February 2024. Participants completed a questionnaire designed to assess their self-perception of facial asymmetry and socio-demographic characteristics. The questionnaire included 10 questions on self-perception of facial asymmetry and 8 questions on socio-demographic data. Statistical analysis was performed using SPSS 26.0, and the Pearson Chi-square test was used for comparative analysis. Results: The sample was predominantly female (75.3%) with an average age of 32.24 years. Most participants were from urban areas (80.6%) and had university degrees (58.7%). About 28.7% of participants observed facial asymmetry, with dental asymmetry being the most frequently reported, followed by asymmetries in the eyebrows and eyelids. The right side of the face was more commonly perceived as asymmetric. Although 24.4% of participants were bothered by their asymmetry, 39.2% expressed a desire to correct it. Conclusions: One-third of participants identified dento-facial asymmetry, with the dental level being the most reported. A significant portion of participants expressed a desire to correct their asymmetries, highlighting the importance of understanding self-perception in the context of facial aesthetics. This study underscores the subjective nature of facial asymmetry perception and the varying thresholds for what is considered bothersome or in need of correction.

The super‐recogniser advantage extends to the detection of hyper‐realistic face masks

AbstractHyper‐realistic silicone masks provide a viable route to identity fraud. Over the last decade, more than 40 known criminal acts have been committed by perpetrators using this type of disguise. With the increasing availability and bespoke sophistication of these masks, research must now focus on ways to enhance their detection. In this study, we investigate whether super‐recognisers (SRs), people who excel at identity recognition, are more likely to detect this type of fraud, in comparison to typical‐recogniser controls. Across three tasks, we examined mask detection rates in the absence of a pre‐task prompt (covert task), and again after making participants aware of their use in criminal settings (explicit task). Finally, participants were asked to indicate which aspects of the masks could support their detection (regions of interest task). The findings show an SR advantage for the detection of hyper‐realistic masks across the covert and explicit mask detection tasks. In addition, the eye, mouth, and nose regions appear to be particularly indicative of the presence of a mask. The lack of natural skin texture, proportional features, expressiveness, and asymmetry are also salient cues. The theoretical and applied implications of these findings are discussed.

Asymmetrical individual both left and right otoliths of Tuna Scombrini collected from the Java Sea

Otolith can be used as a natural marker of fish stock or anomalies between individuals within fish stock. This research aims to study the relationships between fish length and otolith length and confirm differences in otolith shape between species in the Scombrini tribe and Carangidae family (Decapterus ruselli). Sample used in our analysis were collected around July - September 2023 from three different location, Rastrelliger brachysoma (Lekok waters, Pasuruan), Scomber australasicus (Bali Strait waters) and Decapterus ruselli (Sendang Biru, South Malang). Total 96 specimens were identified based on morphological character as Rastrelliger brachysoma, Scomber australasicus and Decapterus ruselli. Each of following samples were cut horizontally at the frontal head to open the skull and remove sagitta otolith below the hindbrain using dissecting set, then cleaned and stored dry in microtube 1,5 ml separately for left and right to further documented using Celestron Digital Microscope Pro Gray USB 44308. Otolith morphometric data collected includes maximum length using TpsDig and weight using analytical balance. The relationship between Forked Length (FL) and otolith length, length-weight relationship of otolith was determined using simple linear regression on software Statistical Product and Service Solutions (SPSS). Paired sample t-test was applied to determine asymmetrical size of left and right otoliths. In this study, it was found that the shape of the otoliths between species has differences in the rostrum, antirostrum, ventral and dorsal parts. FL-otolith length relationship of S. australasicus, R. brachysoma and D. ruselli are Y=0,725+0,164X, r2= 0,519; Y=0,191+0,230X, r2= 0,911; Y=3,156+0,075X, r2=0,071 respectively. The LW sagitta relationship shows that there is a very strong relationship (P<0,05) between L and W of otoliths. The results of the Paired Sample T-test showed that there was no significant difference in the size of the left and right otoliths (Sig>0.05). Otolith shape is influenced by fish behaviour, diet and environment and it may be used as additional information to distinguish between tribe or even species. Otherwise, its asymmetric relationship and LW relationship may be potential new methods for stock discrimination and have other implications such as stock assessment, understanding natural asymmetry, and its potential applications in fisheries management and conservation.

Analysis of molecular phenotypes in normal mucosa and colorectal cancer in embryonic anatomical parts of the colon

Background: Differences in the embryonic development of the colonic mucosa determine the physiological embryonic-anatomical asymmetry of its structure and can manifest themselves via different molecular phenotypes (expression profiles) of the colon segments. These molecular characteristics are hypothesized to determine differences in the carcinogenesis mechanisms and influence the prognosis of right- or left-sided colorectal cancer (CRC). Studies of the tumors molecular phenotypes depending on their localization may be of interest for assessment of the prognosis and choice of treatment for CRC.&#x0D; Aim: To perform comparative analysis of molecular phenotypes of the normal colonic mucosa and adenocarcinoma CRC tissues depending on the natural embryonic anatomic asymmetry of the colon.&#x0D; Materials and methods: We performed a retrospective study of molecular phenotypes (mRNA expression of 61 genes) from different embryonic-anatomical parts of healthy colon and CRC. The normal group included 254 samples of mucosa from three different parts of the colon from 74 healthy donors who had no cancer and no organic abnormalities of the colon, including 90 samples from the right colon, 116 from the left colon, and 48 from the rectum. The CRC group consisted of 154 samples of localized stage T1–4N0–2M0 adenocarcinoma from 154 patients who had not received neoadjuvant radio- and chemotherapy, including 40 samples from the right colon, 54 from the left colon, and 60 from the rectum. The relative mRNA abundance of 61 genes was assessed by reverse-transcriptase polymerase chain reaction. In both groups, the resulting expression phenotypes were compared between the anatomical parts of the colon. Statistical management of the data included the discriminant analysis with stepwise inclusion of variables.&#x0D; Results: Based on the assessment of the mRNA level of the studied genes, a discriminant model was built that allows for classification of the normal group samples according to their anatomic origin in the colon with an accuracy of 95.8%. The most significant (p 0.05) for classification are the following 19 genes: CCND1, SCUBE2, TERT, BAG1, NDRG, IL1b, IL2Ra, IL7, ESR1, TGFb, IGF1, MMP9, MMP11, PAPPA, CD45, CD69, TLR2, TLR4, LIFR. The discriminant model built for the CRC group included 27 genes and made it possible to differentiate samples from three parts of colon with an accuracy of 75.2%. A statistically significant (p 0.05) contribution to the samples differentiation by the discriminant model was made by the COX-2, BIRC5, LIFR, TPA, IL1b, MMP11, MMP7, and P16INK4A genes. When combining samples from the two groups into one model in accordance with their embryonic-anatomical origin, there was a clear separation of tumor tissue samples and healthy colonic mucosa in the discriminant function space.&#x0D; Conclusion: The analysis of CRC gene expression profiles using the discriminant model showed that genetic changes in the colonic mucosa in CRC flatten the molecular phenotypic boundaries of the embryonic-anatomical parts. These changes are specific to CRC, forming a particular “pathological” molecular phenotype.

The use of hemifusion to create asymmetric giant unilamellar vesicles: Insights on induced order domains.

The natural asymmetry of the lipid bilayer in biological membranes is, in part, a testament to the complexity of the structure and function of this barrier limiting and protecting cells (or organelles). These lipid bilayers consist of two lipid leaflets with different lipid compositions, resulting in unique interactions within each leaflet. These interactions, combined with interactions between the two leaflets, determine the overall behavior of the membrane. Model membranes provide the most suitable option for investigating the fundamental interactions of lipids. This report describes a comprehensive method to make asymmetric giant unilamellar vesicles (aGUVs) using the technique of hemifusion. In this method, calcium ions induce the hemifusion of giant unilamellar vesicles (GUVs) with a supported lipid bilayer (SLB), both having different lipid compositions. During hemifusion, a stalk, or a more commonly seen hemifusion diaphragm, connects the outer leaflets of GUVs and the SLB. The lateral diffusion of lipids naturally promotes the lipid exchange between the connected outer leaflets. After calcium chelation to prevent further fusion, a mechanical shear detaches aGUVs from the SLB. A fluorescence quench assay is employed to test the extent of bilayer asymmetry. A fluorescence quenching assay tests bilayer asymmetry and verifies dye and lipid migration to a GUV's outer leaflet.

Method of Reducing the Effects of Repeated Ignition during Earth Faults in Compensated Medium Voltage Networks

The article presents the results of research in the field of limiting the effects of overvoltages and improving the conditions for the self-extinguishing of transient faults in medium voltage networks with earth fault current compensation. The aim of the research was to estimate the level of overvoltages generated by an earth fault during re-ignition of the electric arc and to assess the possibility of reducing them by increasing the attenuation of the earth fault circuit. The results of the conducted tests show that to increase the attenuation, which ensures a significant effect of limiting such overvoltages, it is enough to change the way of operation of the devices forcing an additional active component of the earth fault current (AWSCz/ACFA). In Poland, such devices are commonly used to improve the effectiveness of earth fault protection. It was also found that the proposed solution enables accurate tuning of the Petersen coil in networks with natural asymmetry of earth capacitances. Therefore, changes in the operation of AWSCz/ACFA devices may have a beneficial effect on the limiting the effects of repeated ignitions during earth faults and, at the same time, enable the accurate tuning of the Petersen coil and increase its ability to extinguish arc-fed faults. Research and theoretical analysis of the issue were carried out on the basis of data characterizing the parameters of the earth fault circuits of the real 15 kV network.

Asymmetric Dependence in Hydrological Extremes

AbstractExtremal dependence describes the strength of correlation between the largest observations of two variables. It is usually measured with symmetric dependence coefficients that do not depend on the order of the variables. In many cases, there is a natural asymmetry between extreme observations that cannot be captured by such coefficients. An example for such asymmetry is large discharges at an upstream and a downstream stations on a river network: an extreme discharge at the upstream station will directly influence the discharge at the downstream station, but not vice versa. Simple measures for asymmetric dependence in extreme events have not yet been investigated. We propose the asymmetric tail Kendall's τ as a measure for extremal dependence that is sensitive to asymmetric behavior in the largest observations. It essentially computes the classical Kendall's τ but conditioned on the extreme observations of one of the two variables. We show theoretical properties of this new coefficient and derive a formula to compute it for existing copula models. We further study its effectiveness and connections to causality in simulation experiments. We apply our methodology to a case study on river networks in the United Kingdom to illustrate the importance of measuring asymmetric extremal dependence in hydrology. Our results show that there is important structural information in the asymmetry that would have been missed by a symmetric measure. Our methodology is an easy but effective tool that can be applied in exploratory analysis for understanding the connections among variables and to detect possible asymmetric dependencies.

Development of an arc extinguishing reactor control system

Subject of research: the system of automatic control of the arc-extinguishing reactor.&#x0D; Purpose of research: development of an automatic control system of an arc-extinguishing reactor to improve the efficiency of the electrical network.&#x0D; Object of research: 6-35 kV electric networks with compensated neutral through an arc-extinguishing reactor.&#x0D; Methods of research: the main provisions of the theory of electrical circuits, mathematical analysis and modeling, numerical programming.&#x0D; Main results of research: The article proposes the idea of using the wavelet transform to organize software The article proposes a refined mathematical model of a distribution network with an arc-extinguishing reactor, which allows to increase the accuracy of determining network parameters, including the neutral offset voltage. The algorithm of the reactor settings according to the extreme method in the absence of a single-phase earth fault in a distribution network with a high natural asymmetry.

Coronal, Sagittal, and Horizontal Classification of the Chest Shape and Its Role in Selection of Proper Implants.

The number of female breast correction procedures has been steadily increasing. Despite extensive literature being available on these procedures, few authors have discussed the role of preoperative chest wall analysis in relation to postoperative outcomes. To date, no comprehensive classification of chest shape has been introduced in the literature. The aim of this study was to present a novel classification of chest shapes, based on three basic planes: coronal (C), sagittal (S), and horizontal (H), hence the proposed name "CSH classification." In this study, a retrospective analysis of 1000 randomly selected chest and breast images was conducted by three independent nonmedical evaluators, using standardized digital images captured with the Vectra 3D body scanner. All examined patients were qualified for breast augmentation surgery. Among 1000 randomly examined patients, 923 were classified in the coronal plane, 920 in the sagittal plane, and 627 in the horizontal plane. Other patients were excluded from the study due to insufficient quality of the images. A notable 43.2% of women have shoulder height asymmetries. A relationship between shoulder height asymmetry and chest width was confirmed by the chi-square Pearson test (P = 0.04), indicating that a higher shoulder is associated with a greater chest width on the same side. Furthermore, 84.7% of women displayed excessive upper chest projection, whereas 28.4% showed excessive lower chest projection. Additionally, 84.4% of women had chest projection asymmetries. The vast majority of the women had natural asymmetries of the breast or and chest wall. The CSH classification allows systematizing the chest shape assessment. The chest shape has a significant impact on breast implant selection and the choice of the breast surgery technique.

Embracing asymmetry in nature: How to account for skewness in ecological data

Asymmetric regression is an alternative to conventional linear regression that allows us to model the relationship between predictor variables and the response variable while accommodating skewness. Advantages of asymmetric regression include incorporating realistic ecological patterns observed in data, robustness to model misspecification and less sensitivity to outliers. Bayesian asymmetric regression relies on asymmetric distributions such as the asymmetric Laplace (ALD) or asymmetric normal (AND) in place of the normal distribution used in classic linear regression models. Asymmetric regression concepts can be used for process and parameter components of hierarchical Bayesian models and have a wide range of applications in data analyses. In particular, asymmetric regression allows us to fit more realistic statistical models to skewed data and pairs well with Bayesian inference. We first describe asymmetric regression using the ALD and AND. Second, we show how the ALD and AND can be used for Bayesian quantile and expectile regression for continuous response data. Third, we consider an extension to generalize Bayesian asymmetric regression to survey data consisting of counts of objects. Fourth, we describe a regression model using the ALD, and show that it can be applied to add needed flexibility, resulting in better predictive models compared to Poisson or negative binomial regression. We demonstrate concepts by analyzing a data set consisting of counts of Henslow’s sparrows following prescribed fire and provide annotated computer code to facilitate implementation. Our results suggest Bayesian asymmetric regression is an essential component of a scientist’s statistical toolbox.

Absorbing the arrow of electromagnetic radiation

We argue that the asymmetry between diverging and converging electromagnetic waves is just one of many asymmetries in observed phenomena that can be explained by a past hypothesis and statistical postulate (together assigning probabilities to different states of matter and field in the early universe). The arrow of electromagnetic radiation is thus absorbed into a broader account of temporal asymmetries in nature. We give an accessible introduction to the problem of explaining the arrow of radiation and compare our preferred strategy for explaining the arrow to three alternatives: (i) modifying the laws of electromagnetism by adding a radiation condition requiring that electromagnetic fields always be attributable to past sources, (ii) removing electromagnetic fields and having particles interact directly with one another through retarded action-at-a-distance, (iii) adopting the Wheeler-Feynman approach and having particles interact directly through half-retarded half-advanced action-at-a-distance. In addition to the asymmetry between diverging and converging waves, we also consider the related asymmetry of radiation reaction.

Natural line profile asymmetry

The paper discusses the line profile asymmetry of the photon scattering process that arises naturally in quantum electrodynamics (QED). Based on precision spectroscopic experiments conducted on hydrogen atoms, we focus our attention on the two-photon 1s − 2s transition. As one of the most precisely determined transition frequencies, it is a key pillar of optical frequency standards and is used in determining fundamental physical constants, testing physical principles, and searching constraints on new fundamental interactions. The results obtained in this work show the need to take into account the natural line profile asymmetry in precision spectroscopic experiments.

No Effect of EVA and TPU Custom Foot Orthoses on Mechanical Asymmetries during Acute Intense Fatigue

This study examined the impact of custom foot orthoses made of ethyl-vinyl acetate (EVA) and expanded thermoplastic polyurethane (TPU) materials, both compared to a control condition (CON; shoes only), on mechanical asymmetries during repeated treadmill sprints. Eighteen well-trained male runners executed eight, 5-s sprints (rest: 25 s) on an instrumented motorized treadmill in three footwear conditions (EVA, TPU, and CON). We evaluated the group mean asymmetry scores using the ‘symmetry angle’ (SA) formula, which assigns a score of 0% for perfect symmetry and a score of 100% for perfect asymmetry. There was no condition (all p ≥ 0.053) or time (p ≥ 0.074) main effects, nor were there any significant time × condition interactions on SA scores for any variables (p ≥ 0.640). Mean vertical, horizontal, and total forces presented mean SA values (pooled values for the three conditions) of 2.6 ± 1.9%, 2.9 ± 1.6%, and 2.4 ± 1.8%, respectively. Mean SA scores were ~1–3% for contact time (1.5 ± 0.5%), flight time (3.0 ± 0.3%), step frequency (1.1 ± 0.5%), step length (1.9 ± 0.7%), vertical stiffness (2.1 ± 0.9%), and leg stiffness (2.4 ± 1.1%). Mean SA scores were ~2–6.5% for duration of braking (4.1 ± 1.6%) and propulsive (2.4 ± 1.0%) phases, and peak braking (6.2 ± 2.9%) and propulsive (2.1 ± 1.4%) forces. In well-trained runners facing intense fatigue, wearing custom foot orthoses did not modify the observed low-to-moderate natural stride mechanical asymmetries.

The team allocator game: Allocation power in public goods games

We analyze linear, weakest-link and best-shot public goods games where a distinguished team member, the team allocator, has property rights over the benefits from the public good to distribute it among team members. Our team allocator games are intended to capture natural asymmetries in hierarchical teams facing social dilemmas, such as those in work teams. We show that introducing a team allocator leads to increased contributions in linear and best-shot public-good games. No effect can be found in the weakest-link public good. The team allocator uses her power to distribute benefits in a way that motivates people to contribute. Re-allocating team payoffs allows her to reward contributing team members and to sanction non-cooperating members at no efficiency losses from explicit sanctioning costs. Thus, team profits are higher in the linear team allocator game but not in the best-shot case, where coordination problems lower the welfare for the remaining team members.

An analysis of lateralized neural crest marker expression across development in the Mexican tetra, Astyanax mexicanus.

The biological basis of lateralized cranial aberrations can be rooted in early asymmetric patterning of developmental tissues. However, precisely how development impacts natural cranial asymmetries remains incompletely understood. Here, we examined embryonic patterning of the cranial neural crest at two phases of embryonic development in a natural animal system with two morphotypes: cave-dwelling and surface-dwelling fish. Surface fish are highly symmetric with respect to cranial form at adulthood, however adult cavefish harbor diverse cranial asymmetries. To examine if lateralized aberrations of the developing neural crest underpin these asymmetries, we used an automated technique to quantify the area and expression level of cranial neural crest markers on the left and right sides of the embryonic head. We examined the expression of marker genes encoding both structural proteins and transcription factors at two key stages of development: 36hpf (∼mid-migration of the neural crest) and 72hpf (∼early differentiation of neural crest derivatives). Interestingly, our results revealed asymmetric biases at both phases of development in both morphotypes, however consistent lateral biases were less common in surface fish as development progressed. Additionally, this work provides the information on neural crest development, based on whole-mount expression patterns of 19 genes, between stage-matched cave and surface morphs. Further, this study revealed 'asymmetric' noise as a likely normative component of early neural crest development in natural Astyanax fish. Mature cranial asymmetries in cave morphs may arise from persistence of asymmetric processes during development, or as a function of asymmetric processes occurring later in the life history.