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This registration includes the hypotheses and analytic plan document for secondary data analysis of the DRRAW I parent project (osf.io/ekv6x).

Objective Value in evaluating error subtypes on visuospatial line orientation tests has been reported. Directional bias metrics for line orientation test errors represent easily quantifiable data that have not previously been studied. We evaluated whether patients with a clinical condition known to affect visuospatial functioning (Parkinson’s disease [PD]) exhibited unique directional error patterns on the RBANS Line Orientation test relative to other neuropsychology-referred patients. Method We compared overall directional bias in errors, directional bias by line location (left or right line and visual field), and absolute error rates (regardless of direction) by line location in a retrospective sample of patients with PD and a sample of neuropsychology-referred patients without PD. Groups were roughly matched on age, education, gender, and overall level of cognitive impairment. Results Patients with PD exhibited higher rates of leftward bias in errors, both overall and for the left stimulus line in each pair. Directional bias error scores better predicted PD versus non-PD group status than RBANS Line Orientation raw scores. Classification accuracy data for these variables were modest in the entire sample but stronger in a subsample of patients with mild levels of overall cognitive impairment. Conclusions Directional bias metrics for line orientation tests represent easily quantifiable data with potential theoretical and clinical value. In our sample, patients with PD made more left-biased line orientation errors than other neuropsychology-referred patients. By themselves, directional bias scores may have limited diagnostic potential, but they may be useful in diagnostic classification models and may have implications for clinical care.

In this study, we coded art painted on rocks located in southern Africa, which was painted with a mixture of ochre, blood, and clay by the San, a Neolithic culture with no written language. These images depict a mixture of humans and animals in a variety of contexts, including (but not limited to) hunts and dances. We calculated a laterality index for the collected available art from each region, finding that although there was variability across regions in the direction of the laterality scores, most regions contained a majority of figures facing rightward. This is in stark contrast with reports of artists drawing leftward facing animals and human profiles (an effect that is influenced by native language writing system direction, gender, and handedness), but interestingly our sample also contained regions with strong leftward biases. Our results are, however, in accord with studies that report people preferring images that depict left-to-right motion, as well as the left-to-right bias in depicting transitive actions, an effect that seems to result from greater right hemispheric activation in scene processing and interpretation. Thus, this study shows that in the absence of a writing system, right-lateralized neural architecture may guide the hands of artists.

Neutrophils use their ability to deform surrounding extracellular matrix and turn to navigate through complex 3D environments., Neutrophils migrating through extravascular spaces must negotiate narrow matrix pores without losing directional movement. We investigated how chemotaxing neutrophils probe matrices and adjust their migration to collagen concentration ([col]) changes by tracking 20,000 cell trajectories and quantifying cell-generated 3D matrix deformations. In low-[col] matrices, neutrophils exerted large deformations and followed straight trajectories. As [col] increased, matrix deformations decreased, and neutrophils turned often to circumvent rather than remodel matrix pores. Inhibiting protrusive or contractile forces shifted this transition to lower [col], implying that mechanics play a crucial role in defining migratory strategies. To balance frequent turning and directional bias, neutrophils used matrix obstacles as pivoting points to steer toward the chemoattractant. The Actin Related Protein 2/3 complex coordinated successive turns, thus controlling deviations from chemotactic paths. These results offer an improved understanding of the mechanisms and molecular regulators used by neutrophils during chemotaxis in restrictive 3D environments.

1AbstractAggregate Hi-C maps centered on several genetic elements show significant DNA extrusion features. However, these features are missing from the component Hi-C images. To resolve this discrepancy, we present a new computational framework that reconstructs DNA extrusion scenarios (DESs) and explains the enhancement of DNA extrusion features by aggregation. We showed that the reconstructed DES is essential to understand the site interactions of the relevant genetic elements. For example, CCCTC-binding factor (CTCF) binding elements (CBE) with a specific motif direction are only affected by DNA extrusion activities initiated from one side, manifested as a directional bias. About half of promoters search for enhancers in a specific direction, as indicated by the corresponding DES. Moreover, since DNA extrusion does not pause at promoter or enhancer elements, direct promoter-enhancer contacts are not long-lasting; rather, promoters and enhancers are brought in proximity by continuous, dynamic DNA extrusion.

Among the Tsimane’ people of Bolivia, concepts of number, size, and time have spatial structure but no consistent direction., In industrialized groups, adults implicitly map numbers, time, and size onto space according to cultural practices like reading and counting (e.g., from left to right). Here, we tested the mental mappings of the Tsimane’, an indigenous population with few such cultural practices. Tsimane’ adults spatially arranged number, size, and time stimuli according to their relative magnitudes but showed no directional bias for any domain on any spatial axis; different mappings went in different directions, even in the same participant. These findings challenge claims that people have an innate left-to-right mapping of numbers and that these mappings arise from a domain-general magnitude system. Rather, the direction-specific mappings found in industrialized cultures may originate from direction-agnostic mappings that reflect the correlational structure of the natural world.

IntroductionCurrent research indicates divergent spatiotemporal tauopathy progression between conditions and implicates transsynaptic connectome-based spread as a main mechanism. We examine tauopathy and connectome interactions to investigate why different spatiotemporal patterns of pathology arise.MethodsWe test whether divergent spatiotemporal tau pathology patterns from 15 mouse-model datasets can be explained by a directional bias in tau transmission along fiber tracts via a mathematical model called Directed Network Transmission (DNT).ResultsAmyloid-comorbid tauopathic mouse models meant to mimic AD demonstrate spatiotemporal tauopathy patterns consistent with retrograde direction spread biases. Non-amyloid-comorbid mice demonstrate no consistent spread biases. Further, canonically ‘early’ tau pathology regions in AD are implicated as having earliest pathology in a simulation with random tauopathy seeding locations with retrograde biased spread.DiscussionThese results implicate directional biases in tau pathology spread along fiber tracts as a strong candidate explanation for divergent spatiotemporal tau progression between conditions.

Adults’ linguistic background influences their sequential statistical learning of an artificial language characterized by conflicting forward-going and backward-going transitional probabilities. English-speaking adults favor backward-going transitional probabilities, consistent with the head-initial structure of English. Korean-speaking adults favor forward-going transitional probabilities, consistent with the head-final structure of Korean. These experiments assess when infants develop this directional bias. In the experiments, 7-month-old infants showed no bias for forward-going or backward-going regularities. By 13 months, however, English-learning infants favored backward-going transitional probabilities over forward-going transitional probabilities, consistent with English-speaking adults. This indicates that statistical learning rapidly adapts to the predominant syntactic structure of the native language. Such adaptation may facilitate subsequent learning by highlighting statistical structures that are likely to be informative in the native linguistic environment. Ministry of Education (MOE) We are grateful to Sook Whan Cho and Hongoak Yun for facilitating data collection at Asan Hospital in Seoul, South Korea, and Jae-un Kim and Young-In Lee for running Experiment 2. Support came from a Start Up Grant and a Singapore Ministry of Education Tier 1 grant (RG81/14) to L.O.

Objective: to measure the accuracy of brackets transfer with two indirect bonding techniques using cone beam computed tomography. Materials and Methods: One hundred fourty brackets were bonded to fourteen subjects (upper arch) receiving orthodontic treatments. Orthodontic brackets will placed on the casts with an adhesive. After bracket placement, Cone beam computed tomography (CBCT) scans of the casts obtained .After bracket transfer another Cone beam computed tomography (CBCT) scans of the subjects obtained. The corresponding teeth on both models will then digitally superimposed. All data collected will be tabulated and statistically analyzed. Results: The indirect bonding method investigated in this study was accurate and reliable within the specified acceptable boundaries with directional bias specially toward gingival Conclusion: Vacuum formed technique were significantly less accurate than silicone based technique in the Occlusogingival direction.

Helmet design and development are an important tool to help mitigate the severity and frequency of head and brain injury in sport and everyday life. Helmet assessment protocols and standards often use the Hybrid III neckform as part of the impacting equipment even though it has a biased response that can affect the results. This research presents an unbiased neckform that can be used for the purposes of head impact testing that does not provide a mechanical directional bias to the impact result. A Hybrid III headform was impacted under a sporting impact protocol with a Hybrid III and an unbiased neckform. The resultant acceleration magnitudes were similar between the two necks, while larger differences (8 g and up to 4 krad/s2) were found between the acceleration components. The Hybrid III neck may have a more biased response for longer duration events (10 ms+) as this research considered only short duration impacts (5–10 ms).

This study analyzes three tibia length measurement techniques on a sample of 107 tibiae. Two of the techniques meet published criteria by resting the tibia on its posterior surface with the longitudinal axis parallel to an osteometric board. The third technique does not adequately keep the longitudinal axis parallel to the board. Statistical analyses show low levels of interobserver error for all techniques and statistically significant differences between the third technique and the other two techniques. Results report a maximum difference of 6 mm between measurement techniques with the third technique having greater than 95% directional bias. A survey sent out to the American Academy of Forensic Sciences forensic anthropology community reported more than 50% of respondents having been taught the third technique when an osteometric board with a slot/hole is not available. The intermixing of the third technique with the other two has likely contributed to higher levels of interobserver error in tibia length measurements.

Geometrical features are known to be very important in neuronal growth and the formation of neuronal networks. We present an experimental and theoretical investigation of axonal growth and dynamics for neurons cultured on patterned polydimethylsiloxane surfaces. We utilize fluorescence microscopy to image the axonal dynamics and show that these substrates impart a strong directional bias to neuronal growth. We model axonal dynamics using a general stochastic model and use this framework to extract key dynamical parameters. These results provide novel insight into how geometrical cues influence neuronal growth and represent important advances toward bioengineering neuronal growth platforms.

Evolutionary transitions between male and female heterogamety are common in both vertebrates and invertebrates. Theoretical studies of these transitions have found that, when all genotypes are equally fit, continuous paths of intermediate equilibria link the two sex chromosome systems. This observation has led to a belief that neutral evolution along these paths can drive transitions, and that arbitrarily small fitness differences among sex chromosome genotypes can determine the system to which evolution leads. Here, we study stochastic evolutionary dynamics along these equilibrium paths. We find non-neutrality, both in transitions retaining the ancestral pair of sex chromosomes, and in those creating a new pair. In fact, substitution rates are biased in favor of dominant sex determining chromosomes, which fix with higher probabilities than mutations of no effect. Using diffusion approximations, we show that this non-neutrality is a result of “drift-induced selection” operating at every point along the equilibrium paths: stochastic jumps off the paths return with, on average, a directional bias in favor of the dominant segregating sex chromosome. Our results offer a novel explanation for the observed preponderance of dominant sex determining genes, and hint that drift-induced selection may be a common force in standard population genetic systems.

We examined asymmetry in the color of the dewlap of Anolis lineatus from Curacao. We confirmed previous reports that one side of the dewlap appears more yellow in color than the other and, contrary to previous work, demonstrate a directional bias such that the left side is usually the more yellow side. At one site surveyed twice in 3.5 years, the proportion of left- and right-sided males changed significantly. A behavioral experiment failed to find a significant tendency for males to direct the more yellow or more orange side of the dewlap to other individuals while displaying.

Background When performing the clock-drawing test healthy participants often draw the clock face using a counter clockwise movement. The reason for this circular directional bias is not known. These actions may be related to the development of motor or attentional programs that associate leftward with downward movements, and rightward with upward movements. Methods To further examine this down-left, up-right programming hypothesis, we examined the direction of circular movements made during cursive writing by dividing the first curved movements into the following pairs, up versus down, and leftward versus rightward. Results and conclusions With almost all the letters analyzed, when initially moving upward there was a simultaneous rightward movement and when initially moving downward a leftward movement. The results suggest that there appears to be a relationship between downward and leftward movements as well as between upward and right rightward movements. In addition, there is some evidence to suggest that the right-upward movements may be mediated by the left hemisphere and left-downward movements by the right hemisphere. Although our results suggest motor or spatial attentional programs may account for counter clockwise face drawing, activities such as learned writing direction may influence this spatial bias. Therefore, additional research is needed to better understand if these spatial biases are learned or intrinsic and the neuropsychological mechanisms that might account for these asymmetries.

The sensory physiology and behaviour of many fish species are strongly affected by light. This short study demonstrates that in the Australasian snapper (Chrysophrys auratus) absolute light intensity governs visual acuity and also guides preference behaviour, with fish choosing to ‘rest where they see best’. Use of the optomotor response to test visual acuity at four light intensities (0.01, 0.05, 1 and 3 μmol s−1 m2), showed that visual acuity (measured as directional bias) was best at a light intensity of 0.05 μmol s−1 m2 (84.9% directional bias), but weakened at the highest and lowest light intensity (41.1 and 35.3%). When provided with a choice of the same four light environments fish also spent most time in the 0.05 μmol s−1 m2 light environment, while the highest and lowest intensity light environments were usually avoided. Acclimated light intensity (that is daytime light intensity of the home aquarium) was also 0.05 μmol s−1 m2. By selecting an environment where visual function is optimise...

OBJECTIVE We aimed to assess the extent to which therapists' reports of client functioning track their clients' changing experience of their own functioning from session to session (temporal congruence) as well as the extent to which they over- or underestimate their clients' functioning (level or directional bias) and to examine whether these indices predict treatment outcomes. METHOD The participants included 384 clients who were treated by 77 therapists. Both clients and therapists rated the clients' functioning each session. The clients also completed pre- and posttreatment outcome measures. RESULTS Using multilevel modeling, we found that therapists' reports regarding their clients' functioning tended to be temporally congruent from session to session with their clients' reported functioning. In addition, on average, therapists did not show a level bias (i.e., did not over- or underestimate their clients' functioning). Finally, temporal congruence (but not level bias) predicted better treatment outcomes. CONCLUSION These findings highlight the importance of tracking clients' fluctuating symptoms over time. Thus, we discuss their implication for the policy and practice of providing session-by-session feedback to therapists. (PsycINFO Database Record

The stream-bounce effect refers to a bistable motion stimulus that is interpreted as two targets either “streaming” past or “bouncing” off one another, and the manipulations that bias responses. Directional bias, according to Bertenthal et al., is an account of the effect proposing that low-level motion integration promotes streaming, and its disruption leads to bouncing, and it is sometimes cited either directly in a bottom-up fashion or indirectly under top-down control despite Sekuler and Sekuler finding evidence inconsistent with it. We tested two key aspects of the hypothesis: (a) comparable changes in speed should produce comparable disruptions and lead to similar effects; and (b) speed changes alone should disrupt integration without the need for additional more complex changes of motion. We found that target motion influences stream-bounce perception, but not as directional bias predicts. Our results support Sekuler and Sekuler and argue against the low-level motion signals driving perceptual outcomes in stream-bounce displays (directly or indirectly) and point to higher level inferential processes involving perceptual history and expectation. Directional bias as a mechanism should be abandoned and either another specific bottom-up process must be proposed and tested or consideration should be given to top-down factors alone driving the effect.

Enigma is an op-art painting that elicits an illusion of rotational streaming motion. In the present study, we tested whether adaptation to various motion configurations that included relative motion components could be reflected in the directional bias of the illusory stream. First, participants viewed the center of a rotating Enigma stimulus for adaptation. There was no physical motion on the ring area. During the adaptation period, the illusory stream on the ring was mainly seen in the direction opposite to that of the physical rotation. After the physical rotation stopped, the illusory stream on the ring was mainly seen in the same direction as that of the preceding physical rotation. Moreover, adapting to strong relative motion induced a strong bias in the illusory motion direction in the subsequently presented static Enigma stimulus. The results suggest that relative motion detectors corresponding to the ring area may produce the illusory stream of Enigma.

The purpose of the current study was to explore the influence of the distance of a wall located behind the hole in performing a putt in golf. Our assumption was that a performance condition where the wall is located a short distance behind the hole would help novices minimize any left/right directional bias. Novice golfers performed a putting task from a distance of two m in front of the hole in two learning settings. In the Far Wall Condition, a wall was located 4 m behind the hole, and in the Close Wall Condition the wall was located 90 cm behind the hole. The putt was performed under both quiet and distracted conditions. Results showed that overall accuracy was greater in the Close Wall Condition than in the Far Wall Condition. In addition, different patterns of left/right directional bias in the two performance conditions were observed. However, the hitting deviations were more balanced in the Close Wall Condition. It is recommended that coaches consider the use of environmental cues that have the pot...

In this article, I discuss recent research dealing with bias and accuracy of judgments in romantic relationships. First, two components of overall accuracy—directional bias and tracking accuracy—are outlined. Second, a model is described dealing with the causes and consequences of bias and accuracy in partner and relationship judgments, and research is reviewed showing that partners generally exhibit both positive bias and good levels of tracking accuracy. The roles played by various moderating variables (e.g., relationship stage, individual differences) are also discussed. I conclude that bias in relationship judgments is largely functional and that interactions between partners both shape and are shaped by the directional bias and tracking accuracy attendant in relationship and partner judgments.

We describe two experiments on the determinants of motivated judgments. They explored the conjoint effects of three factors: (1) dominant judgmental motivation (geared toward accuracy or directional bias), (2) task demands, and (3) the availability of cognitive resources. We find that where a directional motivation is dominant and task demands are high (making biasing difficult), the presence (vs. absence) of resources promotes wishful judgments. Conversely, where accuracy motivation is dominant and wishful judgments are the default, resources reduce the likelihood of their occurrence. Finally, where a directional motivation is dominant and task demands are low (making biasing easy), or where the accuracy motivation is dominant and task demands are high, resources have relatively minor effects on bias.

Brownian circuits are asynchronous circuits in which signals—represented as tokens—are able to fluctuate along wires. These fluctuations are used as a stochastic search mechanism to drive computations from a state of input to a state of output. Token-Pass circuits are a type of circuits in which wires will not merge or split. Rather, they are linear: each token remains on its wire during computation, and it will interact with other tokens only at points where they pass through circuit elements. The T-element, introduced in [Peper, Lee, Carmona, Cortadella, Morita, “Brownian Circuits: Fundamentals,” 2013], is a circuit element in which three wires pass through, and it was shown to be universal, provided the circuit it is employed in is Brownian. The Brownian circuit designs based on the T-element in the above paper have in common that they implicitly assume a bias in the direction in which tokens flow on average, even though tokens may fluctuate forward and backward during the course of a computation. This chapter proposes a new type of Brownian Token-Pass circuit, called Non-Polar Token-Pass Brownian Circuit, in which no such directional bias is assumed. Though most wires in such circuits do have directional bias, the few wires that don’t, allow for simpler circuit designs, as will be shown.

SummaryThe migration of immune cells is guided by specific chemical signals, such as chemokine gradients. Their trajectories can also be diverted by physical cues and obstacles imposed by the cellular environment, such as topography, rigidity, adhesion, or hydraulic resistance. On the example of hydraulic resistance, it was shown that neutrophil preferentially follow paths of least resistance, a phenomenon referred to as barotaxis. We here combined quantitative imaging and physical modeling to show that barotaxis results from a force imbalance at the scale of the cell, which is amplified by the acto-myosin intrinsic polarization capacity. Strikingly, we found that macropinocytosis specifically confers to immature dendritic cells a unique capacity to overcome this physical bias by facilitating external fluid transport across the cell, thereby enhancing their space exploration capacity in vivo and promoting their tissue-patrolling function. Conversely, mature dendritic cells, which down-regulate macropinocytosis, were found to be sensitive to hydraulic resistance. Theoretical modeling suggested that barotaxis, which helps them avoid dead-ends, may accelerate their migration to lymph nodes, where they initiate adaptive immune responses. We conclude that the physical properties of the microenvironment of moving cells can introduce biases in their migratory behaviors but that specific active mechanisms such as macropinocytosis have emerged to diminish the influence of these biases, allowing motile cells to reach their final destination and efficiently fulfill their functions.

In this chapter, we describe the architecture and motility mechanism of the dynein motor. The two key aspects of dynein motility are the force producing linker power stroke and the cyclic regulation of microtubule binding affinity. We summarize the structural and biochemical data supporting these concepts. We also highlight how the basic mode of dynein motility might be influenced by external regulators such as Lis1. Furthermore, we outline current mechanistic models about how dyneins walk along microtubules and maintain an overall directional bias toward the minus end. In the last section, we refer to very recent findings highlighting how cargo binding might activate dynein motors.

Objective To determine the interrater reliability for identification of a specific movement pattern using a Pilates Classification system. Method Videos of 5 subjects performing specific movement tasks were sent to raters trained in the DMA-CP classification system. Results Ninety-six raters completed the survey. Interrater reliability for the detection of a directional bias was excellent (Pi = 0.92, and K(free) = 0.89). Interrater reliability for classifying an individual into a specific subgroup was moderate (Pi = 0.64, K(free) = 0.55) however raters who had completed levels 1-4 of the DMA-CP training and reported using the assessment daily demonstrated excellent reliability (Pi = 0.89 and K(free) = 0.87). Conclusion The reliability of the classification system demonstrated almost perfect agreement in determining the existence of a specific movement pattern and classifying into a subgroup for experienced raters. There was a trend for greater reliability associated with increased levels of training and experience of the raters.

Skills learned through practice with one limb can often be transferred to the untrained limb. In the present report, we sought to determine whether movement direction biases, acquired through repeated movement with one limb, transfer to the untrained limb. In order to do so, we asked participants to perform synchronised bilateral contractions of muscles in both wrists, followed by the unilateral contraction of muscles in one wrist. In four experiments, we manipulated the position of the unilateral target to create use-dependent directional biases; changed the direction of the cursor in relation to the wrist movement to control for attentional biases; and sought to induce directional biases with both right and left unilateral movements. The results showed clear movement related biases for the wrist that performed unilateral contractions, but no evidence that movement-related bias transferred to the opposite limb during bilateral action. Thus motor preparation and execution of unilateral contractions does not affect the direction of movement made by the opposite limb during subsequent bilateral contractions. This article is protected by copyright. All rights reserved.

Evolutionary transitions between male and female heterogamety are common in both vertebrates and invertebrates. Theoretical studies of these transitions have found that, when all genotypes are equally fit, continuous paths of intermediate equilibria link the two sex chromosome systems. This observation has led to a belief that neutral evolution along these paths can drive transitions, and that arbitrarily small fitness differences among sex chromosome genotypes can determine the system to which evolution leads. Here, we study stochastic evolutionary dynamics along these equilibrium paths. We find non-neutrality, both in transitions retaining the ancestral pair of sex chromosomes and in those creating a new pair. In fact, substitution rates are strongly biased in favor of dominant sex determining chromosomes, which fix with higher probabilities than mutations of no effect. Using diffusion approximations, we show that this non-neutrality is a result of ‘drift-induced selection’ operating at every point along the equilibrium paths: stochastic jumps off the paths return, on average, with a directional bias in favor of the dominant segregating sex chromosome. Our results offer novel explanations for the ubiquity of transitions between male and female heterogamety and the preponderance of dominant major sex determining genes.

Femoral head breadth is widely used in body mass estimation in biological anthropology. Earlier research has demonstrated that reduced major axis (RMA) equations perform better than least squares (LS) equations. Although a simple RMA equation to estimate body size from femoral head breadth is sufficient in most cases, our experiments with male skeletons from European data (including late Pleistocene and Holocene skeletal samples) and the Forensic Anthropology Data Bank data (including the W. M. Bass Donated Skeletal Collection sample) show that including femoral length or anatomically estimated stature in an equation with femoral head breadth improves body mass estimation precision. More specifically, although directional bias related to body mass is not reduced within specific samples, the total estimation error range, directional bias related to stature, and temporal fluctuation in estimation error are markedly reduced. The overall body mass estimation precision of individuals representing different temporal periods and ancestry groups (e.g., African and European ancestry) is thus improved.

Intermittent exposure to a sensorimotor perturbation, such as a visuomotor rotation, is known to cause a directional bias on the subsequent movement that opposes the previously experienced perturbation. To date, it is unclear whether the parietal cortex is causally involved in this postperturbation movement bias. In a recent electroencephalogram study, Savoie et al. (2018) observed increased parietal activity in response to an intermittent visuomotor perturbation, raising the possibility that the parietal cortex could subserve this change in motor behavior. The goal of the present study was to causally test this hypothesis. Human participants (N = 28) reached toward one of two visual targets located on either side of a fixation point, while being pseudorandomly submitted to a visuomotor rotation. On half of all rotation trials, single-pulse transcranial magnetic stimulation (TMS) was applied over the right (N = 14) or left (N = 14) parietal cortex 150 ms after visual feedback provision. To determine whether TMS influenced the postperturbation bias, reach direction was compared on trials that followed rotation with (RS + 1) and without (R + 1) TMS. It was hypothesized that interfering with parietal activity would reduce the movement bias following rotated trials. Results revealed a significant and robust postrotation directional bias compared with both rotation and null rotation trials. Contrary to our hypothesis, however, neither left nor right parietal stimulation significantly impacted the postrotation bias. These data suggest that the parietal areas targeted here may not be critical for perturbation-induced motor output changes to emerge.

This work presents a new local crack tracking technique to improve numerical simulations of localized fracture processes in quasi-brittle structures. The algorithm primarily focuses on reduction of mesh-induced directional bias by the determination of smoothly curved C 1 – continuous crack paths within and across conventional continuum elements with quadratic displacement fields. The algorithm further enables to postpone the moment of crack path fixation. Combined with a classical smeared crack model, the proposed crack propagation algorithm is validated by sequentially linear analyses on tensile and mixed-mode plain concrete fracture tests. Specifically for quadratic elements the results show an increase of the mesh objectivity, and more realistic load–displacement and cracking behaviors are obtained.

Topographical features are known to influence the axonal outgrowth of neurons. Understanding what kinds of topographical features are most effective at growth cone guidance and how outgrowth responds to these structures is of great importance to the study of nerve regeneration. To this end we analyze axonal outgrowth on tilted nanorod substrates which have been shown to impart directional bias to neuron growth. We utilize the Atomic Force Microscope to characterize the surface features present on these substrates and how such features are influencing the axonal outgrowth. Additionally, using a model which considers the neuronal growth cone as an object influenced by an effective potential we determine an effective force imparted on the growth cone by the surface topography.

Although the neural underpinning of bipolar disorder (BD) is still unknown, recent research suggests that the right fronto-parietal cortex is particularly affected in BD patients. If this were true, we would expect atypical functional cerebral asymmetries in allocation of visuospatial attention. To test this hypothesis, euthymic BD patients and age- and gender-matched healthy controls were compared on the visual line-bisection task, a reliable measure of visuospatial attention, associated with right parietal function. Line bisection performance (i.e. absolute and directional bias) was compared between groups as a function of response hand and line position. The results showed a typical hand-use effect in healthy controls involving a larger leftward bias (i.e. pseudoneglect) with the left hand than with the right hand. Although euthymic BD patients did not differ from healthy controls in the overall accuracy (i.e. absolute bias), they differed significantly in the directional line bisection bias. In contrast to healthy controls, BD patients did not significantly deviate from the veridical center, regardless of which hand was used to bisect horizontal lines. This finding indicates an atypical functional cerebral asymmetry in visuospatial attention in euthymic BD patients, supporting the idea of a dysfunction especially in the right fronto-parietal cortex.

Summary Dynamic mathematical modelling and stochastic simulation of disease–host systems for the purpose of epidemiological analysis offer great opportunities for testing hypotheses, especially when field experiments are impractical or when there is a need to evaluate multiple experimental scenarios. This, combined with the ever increasing computer power available to researchers, has contributed to the development of many mathematical models for epidemic simulations, such as the individual-based model (IBM). Nevertheless, few of these models undergo extensive validation and proper assessment of intrinsic variability. The Ontario rabies model (ORM) will be used here to exemplify some advantages of appropriate model behaviour validation and to illustrate the use of a simple geometric procedure for testing directional bias in distributed stochastic dynamic model of spread of diseases. Results were obtained through the comparison of 10 000 epizootics resulting from 100 epidemic simulations started using 100 distinct base populations. The analysis results demonstrated a significant directional bias in epidemic dispersion, which prompted further verification of the model code and the identification of a coding error, which was then corrected. Subsequent testing of the corrected code showed that the directional bias could no longer be detected. These results illustrate the importance of proper validation and the importance of sufficient knowledge of the model behaviour to ensure the results will not confound the objectives of the end-users.

Directing cell movements within 3D channels is a key challenge in biomedical devices and tissue engineering. In two dimensions, closely spaced arrays of asymmetric teardrop islands can intermittently polarize cells and sustain their autonomous directional migration with no gradients. However, in 3D microchannels composed of linearly connected teardrop segments, negligibly low directional bias is observed. Rather than adopt teardrop shapes, cells evade morphological polarization by spreading across multiple teardrop segments, only partly filling each. We demonstrate here that cells can be forced to adopt the shape of individual segments by connecting the segments at an angle to minimize cell spreading across multiple segments. The resulting rhythmic polarization leads to significant directional bias for NIH3T3 fibroblasts, epithelial cells, and even cells whose intracellular signalling have been purposely altered to affect lamellipodia extension (Rac1) and cell polarity (Cdc42). This gradient-free approach to directing cell migration in 3D microchannels may find significant applications in tissue scaffolds and cell on a chip devices.

To determine how counselors' attachment anxiety and avoidance related to congruence between counselors' and clients' Working alliance (WA) ratings. Congruence strength was defined as the regression coefficient for clients' WA ratings predicting counselors' WA ratings. Directional bias was defined as the difference in level between counselors' and clients' WA ratings.Twenty-seven graduate student counselors completed an attachment measure and they and their 64 clients completed a measure of WA early in therapy. The truth-and-bias analysis was adapted to analyze the data.As hypothesized counselors' WA ratings were significantly and positively related to clients' WA ratings. Also as hypothesized, counselors' WA ratings were significantly lower than their clients' WA ratings (directional bias). Increasing counselor attachment anxiety was related to increasing negative directional bias; as counselors' attachment anxiety increased the difference between counselors and clients WA ratings became more negative. There was a significant interaction between counselor attachment anxiety and congruence strength in predicting counselor WA ratings. There was a stronger relationship between client WA ratings and counselor WA ratings for counselors low versus high in attachment anxiety.Counselors' attachment anxiety is realted to their ability to accurately percieve their clients' WA.

Collective cell migration and proliferation are integral to tissue repair, embryonic development, the immune response and cancer. Central to collective cell migration and proliferation are interactions among neighbouring cells, such as volume exclusion, contact inhibition and adhesion. These individual-level processes can have important effects on population-level outcomes, such as growth rate and equilibrium density. We develop an individual-based model of cell migration and proliferation that includes these interactions. This is an extension of a previous model with neighbour-dependent directional bias to incorporate neighbour-dependent proliferation and death. A deterministic approximation to this individual-based model is derived using a spatial moment dynamics approach, which retains information about the spatial structure of the cell population. We show that the individual-based model and spatial moment model match well across a range of parameter values. The spatial moment model allows insight into the two-way interaction between spatial structure and population dynamics that cannot be captured by traditional mean-field models.

The study of asymmetry can provide insights into genetic and environmental influences on organismal development. Directional asymmetry (DA) can be either adaptive or non-adaptive, whereas fluctuating asymmetry (FA) – defined as small non-directional departures from symmetry in bilateral traits – is thought to be an indicator of genetic or environmental stress experienced during development. Using data from 28 European populations, we assessed the degree of DA and FA in the lateral plates of threespine sticklebacks Gasterosteus aculeatus and surveyed the direction of DA and differences in levels of DA and FA in different habitat types (viz. marine, lake and river populations). DA differed between habitats, with right-biased DA found in the marine populations and no directional bias found in lake and river populations. Differences in DA among habitats may be a by-product of habitat-specific developmental instability resulting in asymmetry, or it may indicate habitat-specific differences in selection against/for symmetry, as has been proposed in previous research of sticklebacks. Also, the presence of FA varied depending upon habitat type, but it also depended on plate morph – a variable confounded with the habitat effect. While we cannot rule out factors such as stress as a cause of population differences in FA, it may also simply be a by-product of other evolutionary processes (e.g. lateral plate number reduction) without functional basis.

One of the less-known functional asymmetries in humans is the rightward head-turning bias, in which infants spend more time turning their head to the right, rather than to the left. Observational studies showed that this asymmetry disappears around the age of 3 months. Recently, an intriguing observation found a similar rightward head-turning bias during kissing, apparently indicating that the early head-motor bias persists into adulthood. Here we challenge the theory of the innate head-turning bias in adults during lip kissing, showing by means of behavioral and observational studies that the direction of the bias is culturally dependent. Moreover, we suggest that the head-turning bias during kissing is an acquired behavioral asymmetry, probably shaped by spatial experience within cultural habits (i.e., reading direction), rather than reflecting pre-wired hemispherical lateral asymmetry.

There are three interconnected and fundamental elements that define the spatiality of crime: places, distances, and directions. Over the past 180 years, research has flourished for the first two fundamental elements with relatively little research on directionality. In this article, we develop a visualization technique allowing for the display of the directional bias for a large number of offenders that aids in subsequent analysis. We show that a directional bias in criminal activity is present overall, but is not monolithic. Consequently, urban form and understanding place play a strong role in criminal directional biases for moving through our environments. Se representer le biais directionnel de l’incidence du crime contre la propriete dans cinq municipalites canadiennes Il existe trois elements relies et fondamentaux pour definir le rapport entre le crime et l’espace : les lieux, les distances et les directions. Au cours des 180 dernieres annees, les recherches se sont multipliees portant sur les deux premiers elements fondamentaux aux depens de la question de la directionnalite. Dans cet article, nous elaborons une technique de representation visuelle permettant de mettre en relief le biais directionnel d’un grand nombre de contrevenants dans l’optique d’ameliorer les analyses ulterieures. Il se degage que, dans l’ensemble, un biais directionnel existe au niveau des activites criminelles sans etre monolithique. Par consequent, la forme urbaine et la connaissance du lieu jouent un role de premier plan dans les biais directionnels de la criminalite qui traversent nos milieux de vie.

Individuals in advective environments, for example rivers, coastlines, or the gut, are subject to movement with directional bias. We study how this movement bias shapes community composition by considering how the strength of movement bias affects the outcome of competition among three species. Our model is a system of three reaction–advection–diffusion equations with Danckwerts boundary conditions. Our key tool in this study is to use the dominant eigenvalue of the diffusion–advection operator in order to reduce the spatially explicit model to a spatially implicit ordinary differential equation model. After an in-depth analysis of the implicit model, we use numerical simulations of the explicit model to test the predictions obtained from the analysis. In general, we find a good qualitative agreement between the explicit and the implicit model. We find that varying the strength of advection can fundamentally alter the outcome of competition between the three species, and we characterize the possible transitions. In particular, water extraction and flow control can destabilize existing species communities or facilitate invasions of non-native species.

Wind rose summaries, which provide a basis for understanding and evaluating the climatological behavior of local wind, have a directional bias if a conventional method is used in their generation. Three techniques used to remove this bias are described and are compared for theoretical and observed wind distributions. All three techniques successfully remove the bias, with the simplest of the three performing as well as the more-complex techniques.

Five individuals with autism or other developmental disabilities participated in paired-stimulus preference assessments during repeated baseline probes. All subjects initially showed a pronounced bias by typically selecting the stimulus placed in either the left or right position. Biased responding for 3 subjects was eliminated when training trials were conducted in which a stimulus of known lesser quality was presented as one of the choices. Reinforcer-quality training was unsuccessful for 2 subjects, as was a condition in which reinforcer magnitude was modified to favor unbiased responding. These subjects' biased responding was eliminated only when a correction procedure (repetition of error trials) was implemented.

Throughout his writings about how honeybees communicate with dances, Karl von Frisch described two types of recruitment dance: the round dance, which supposedly indicates the presence of a food source somewhere near the hive, and the waggle dance, which indicates the distance and direction of a food source more than 100 m from the hive. The view that round dances and waggle dances are distinct recruitment signals has been revised in light of the finding that distance and direction information are encoded (albeit imprecisely) in round dances. It has remained unclear, however, whether dance followers can use the location information in round dances. In the present study, we looked at recruitment to nearby food sources and found that dance followers can use the directional information in the dances advertising these food sources. Directional bias in recruitment was found for food sources as close as 5 m from the hive. Controls for effects of assembly pheromone and bee presence at the advertised food sources indicate that these factors play a minimal role, relative to dance information, in producing the directional recruitment. Our results provide further support for the view that round dances are best viewed as waggle dances indicating nearby food sources, not as a separate type of dance.

The aim of the present experiment was to investigate the extent to which the orientation of objects drawn in side view is a function of culture, age, and manual dominance. Right-handed French and Syrian children aged between 6 and 10 years and right-handed adults from the same cultural groups were asked to produce side views of faces, vehicles (car and airplane), self-centered tools with a handle (mug and toothbrush), object-centered tools with a handle (jug and hammer), and animals (dog and fish) using their dominant and nondominant hands. The French participants exhibited a leftward directional bias, whereas their Syrian counterparts displayed a rightward bias. However, no differences between the two cultural groups were observed in the 6-year-olds, who did not present any systematic directional bias in their drawings. Furthermore, regardless of culture, the children did not modify the orientation of the objects in their drawings as a function of the hand used, whereas the hand effect was strong in adults. Finally, despite their directional bias toward the right, the Syrian participants tended to draw the self- and object-centered tools facing leftward. These results are discussed with reference to the current literature on this topic.

We consider the problem of estimating the probability density of the “anchor point” (residence, place of work, etc.) of a criminal offender given a set of observed spatial locations of crimes committed by the offender. Starting from kinetic models of criminal motion and target selection, we derive the probability density of anchor points using the Fokker–Planck equation and Bayes' theorem. Here, geographic inhomogeneities such as housing densities and geographic barriers (bodies of water, parks, etc.) are naturally incorporated into the probability density estimate, as well as directional bias and distance to crime preferences in offender target selection. The resulting equations are steady state advection-diffusion-reaction PDEs. We test our methodology against crime data provided by the Los Angeles Police Department, and our results highlight the benefits of incorporating these elements of criminal behavior and geographic inhomogeneities into profiling estimates.

Our representation of peripersonal space does not always accurately reflect the physical world. An example of this is pseudoneglect, a phenomenon in which neurologically normal individuals bisect to the left of the veridical midpoint, reflecting an overrepresentation of the left portion of space compared with the right one. Consistent biases have also been observed in the vertical and radial planes. It is an open question whether these biases depend on normal visual experience for their occurrence. Here we systematically investigated this issue by testing blindfolded sighted and early blind individuals in a haptic line bisection task. Critically, we found a robust leftward bias in all participants. In the vertical and radial planes, sighted participants showed a consistent downward and proximal bias. Conversely, the directional bias in blind participants was dependent on the final movement direction; thus, there was no general bias in either direction. These findings are discussed in terms of different reference frames adopted by sighted and blind participants when encoding space. (PsycINFO Database Record (c) 2011 APA, all rights reserved). Language: en