Metamagnetic multiband Hall effect in Ising antiferromagnet ErGa2.

Frustrated rare-earth-based intermetallics provide a promising platform for emergent magnetotransport properties through exchange coupling between conduction electrons and localized rare-earth magnetic moments. Metamagnetism, the abrupt change of magnetization under an external magnetic field, is a signature of first-order magnetic phase transitions; recently, metamagnetic transitions in frustrated rare earth intermetallics have attracted interest for their accompanying nontrivial spin structures (e.g., skyrmions) and associated nonlinear and topological Hall effects (THE). Here, we present metamagnetism-induced Hall anomalies in single-crystalline ErGa2, which recalls features arising from the THE but wherein the strong Ising-type anisotropy of Er moments prohibits noncoplanar spin structures. We show that the observed anomalies are neither due to anomalous Hall effect nor THE; instead, can be accounted for via 4f-5d interactions which produce a band-dependent mobility modulation. This leads to a pronounced multiband Hall response across the magnetization process-a metamagnetic multiband Hall effect that resembles a topological-Hall-like response but without nontrivial origins. The present findings may be of general relevance in itinerant metamagnetic systems regardless of coplanar/noncoplanar nature of spins and are important for the accurate identification of Hall signals due to emergent magnetic fields.

Crystallization of heavy fermions via epitaxial strain in spinel LiV2O4 thin film.

The mixed-valent spinel LiV2O4 is known as the first oxide heavy-fermion system. There is a general consensus that a subtle interplay of charge, spin, and orbital degrees of freedom of correlated electrons plays a crucial role in the enhancement of quasi-particle mass, but the specific mechanism has remained yet elusive. A charge-ordering (CO) instability of V3+ and V4+ ions that is geometrically frustrated by the V pyrochlore sublattice from forming a long-range CO down to T = 0 K has been proposed as a prime candidate for the mechanism. Here, we uncover the hidden CO instability by applying epitaxial strain on single-crystalline LiV2O4 thin films. We find a crystallization of heavy fermions in a LiV2O4 film on MgO, where a charge-ordered insulator comprising of a stack of V3+ and V4+ layers along [001], the historical Verwey-type ordering, is stabilized by the in-plane tensile and out-of-plane compressive strains from the substrate. Our discovery of the [001] Verwey-type CO, together with previous realizations of a distinct [111] CO, evidence the close proximity of the heavy-fermion state to degenerate CO states mirroring the geometrical frustration of the V pyrochlore lattice, which supports the CO instability scenario for the mechanism behind the heavy-fermion formation.

Minimal frustration underlies the usefulness of incomplete regulatory network models in biology.

Regulatory networks as large and complex as those implicated in cell-fate choice are expected to exhibit intricate, very high-dimensional dynamics. Cell-fate choice, however, is a macroscopically simple process. Additionally, regulatory network models are almost always incomplete and/or inexact, and do not incorporate all the regulators and interactions that may be involved in cell-fate regulation. In spite of these issues, regulatory network models have proven to be incredibly effective tools for understanding cell-fate choice across contexts and for making useful predictions. Here, we show that minimal frustration-a feature of biological networks across contexts but not of random networks-can compel simple, low-dimensional steady-state behavior even in large and complex networks. Moreover, the steady-state behavior of minimally frustrated networks can be recapitulated by simpler networks such as those lacking many of the nodes and edges and those that treat multiple regulators as one. The present study provides a theoretical explanation for the success of network models in biology and for the challenges in network inference.

Polymorphism in F pocket affects peptide selection and stability of type 1 diabetes-associated HLA-B39 allotypes.

HLA-B*39:06, HLA-B*39:01, and HLA-B*38:01 are closely related HLA allotypes differentially associated with type 1 diabetes (T1D) risk and progression. B*39:06 is highly predisposing, while B*39:01 and B*38:01 are weakly predisposing and protective allotypes, respectively. Here, we aimed to decipher molecular mechanisms underlying the differential association of these allotypes with T1D pathogenesis. We addressed peptide binding and conformational stability of HLA-B allotypes using computational and experimental approaches. Computationally, we found that B*39:06 and B*39:01 allotypes had more rigid peptide-binding grooves and were more promiscuous in binding peptides than B*38:01. Peptidomes of B*39:06 and B*39:01 contained fewer strong binders and were of lower affinity than that of B*38:01. Experimentally, we demonstrated that B*39:06 and B*39:01 had a higher capacity to bind peptides and exit to the cell surface but lower surface levels and were degraded faster than B*38:01. In summary, we propose that promiscuous B*39:06 and B*39:01 may bind suboptimal peptides and transport them the cell surface, where such unstable complexes may contribute to the pathogenesis of T1D.

Two-dimensional quantum universality in the spin-1/2 triangular-lattice quantum antiferromagnet Na2BaCo(PO4)2.

An interplay of geometrical frustration and strong quantum fluctuations in a spin-1/2 triangular-lattice antiferromagnet (TAF) can lead to exotic quantum states. Here, we report the neutron-scattering, magnetization, specific heat, and magnetocaloric studies of the recently discovered spin-1/2 TAF Na2BaCo(PO4)2, which can be described by a spin-1/2 easy axis XXZ model. The zero-field neutron diffraction experiment reveals an incommensurate antiferromagnetic ground state with a significantly reduced ordered moment of about 0.54(2) µB/Co. Different magnetic phase diagrams with magnetic fields in the ab plane and along the easy c-axis were extracted based on the magnetic susceptibility, specific heat, and elastic neutron-scattering results. In addition, two-dimensional (2D) spin dispersion in the triangular plane was observed in the high-field polarized state, and microscopic exchange parameters of the spin Hamiltonian have been determined through the linear spin wave theory. Consistently, quantum critical behaviors with the universality class of d = 2 and νz = 1 were established in the vicinity of the saturation field, where a Bose-Einstein condensation (BEC) of diluted magnons occurs. The newly discovered quantum criticality and fractional magnetization phase in this ideal spin-1/2 TAF present exciting opportunities for exploring exotic quantum phenomena.

Mechanism of temperature-induced asymmetric swelling and shrinking kinetics in self-healing hydrogels.

Understanding the physical principle that governs the stimuli-induced swelling and shrinking kinetics of hydrogels is indispensable for their applications. Here, we show that the shrinking and swelling kinetics of self-healing hydrogels could be intrinsically asymmetric. The structure frustration, formed by the large difference in the heat and solvent diffusions, remarkably slows down the shrinking kinetics. The plateau modulus of viscoelastic gels is found to be a key parameter governing the formation of structure frustration and, in turn, the asymmetric swelling and shrinking kinetics. This work provides fundamental understandings on the temperature-triggered transient structure formation in self-healing hydrogels. Our findings will find broad use in diverse applications of self-healing hydrogels, where cooperative diffusion of water and gel network is involved. Our findings should also give insight into the molecular diffusion in biological systems that possess macromolecular crowding environments similar to self-healing hydrogels.

Robust Spin Liquidity in 2D Metal-Organic Framework Cu3 (HHTP)2 with S=1 /2 Kagome Lattice.

On one hand electron or hole doping of quantum spin liquid (QSL) may unlock high-temperature superconductivity and on the other hand it can disrupt the spin liquidity, giving rise to a magnetically ordered ground state. Recently, a 2D MOF, Cu3 (HHTP)2 (HHTP - 2,3,6,7,10,11-hexahydroxytriphenylene), containing Cu(II) S= 1 / 2 ${{ 1/2 }}$ frustrated spins in the Kagome lattice is emerging as a promising QSL candidate. Herein, we present an elegant in situ redox-chemistry strategy of anchoring Cu3 (HHTP)2 crystallites onto diamagnetic reduced graphene oxide (rGO) sheets, resulting in the formation of electron-doped Cu3 (HHTP)2 -rGO composite which exhibited a characteristic semiconducting behavior (5 K to 300 K) with high electrical conductivity of 70 S ⋅ m-1 and a carrier density of ~1.1×1018  cm-3 at 300 K. Remarkably, no magnetic transition in the Cu3 (HHTP)2 -rGO composite was observed down to 1.5 K endorsing the robust spin liquidity of the 2D MOF Cu3 (HHTP)2 . Specific heat capacity measurements led to the estimation of the residual entropy values of 28 % and 34 % of the theoretically expected value for the pristine Cu3 (HHTP)2 and Cu3 (HHTP)2 -rGO composite, establishing the presence of strong quantum fluctuations down to 1.5 K (two times smaller than the value of the exchange interaction J).

A network approach to the investigation of childhood irritability: probing frustration using social stimuli.

BACKGROUND: Self-regulation in early childhood develops within a social context. Variations in such development can be attributed to inter-individual behavioral differences, which can be captured both as facets of temperament and across a normal:abnormal dimensional spectrum. With increasing emphasis on irritability as a robust early-life transdiagnostic indicator of broad psychopathological risk, linkage to neural mechanisms is imperative. Currently, there is inconsistency in the identification of neural circuits that underlie irritability in children, especially in social contexts. This study aimed to address this gap by utilizing a functional magnetic resonance imaging (fMRI) paradigm to investigate pediatric anger/frustration using social stimuli. METHODS: Seventy-three children (M = 6 years, SD = 0.565) were recruited from a larger longitudinal study on irritability development. Caregivers completed questionnaires assessing irritable temperament and clinical symptoms of irritability. Children participated in a frustration task during fMRI scanning that was designed to induce frustration through loss of a desired prize to an animated character. Data were analyzed using both general linear modeling (GLM) and independent components analysis (ICA) and examined from the temperament and clinical perspectives. RESULTS: ICA results uncovered an overarching network structure above and beyond what was revealed by traditional GLM analyses. Results showed that greater temperamental irritability was associated with significantly diminished spatial extent of activation and low-frequency power in a network comprised of the posterior superior temporal sulcus (pSTS) and the precuneus (p < .05, FDR-corrected). However, greater severity along the spectrum of clinical expression of irritability was associated with significantly increased extent and intensity of spatial activation as well as low- and high-frequency neural signal power in the right caudate (p < .05, FDR-corrected). CONCLUSIONS: Our findings point to specific neural circuitry underlying pediatric irritability in the context of frustration using social stimuli. Results suggest that a deliberate focus on the construction of network-based neurodevelopmental profiles and social interaction along the normal:abnormal irritability spectrum is warranted to further identify comprehensive transdiagnostic substrates of the irritability.

Personal insult disrupts regulatory brain networks in violent offenders.

The failure to adequately regulate negative emotions represents a prominent characteristic of violent offenders. In this functional magnetic resonance imaging study, we used technical, nonsocial frustration to elicit anger in violent offenders (n = 19) and then increased the provocation by adding personal insults (social provocation). The aim was to investigate neural connectivity patterns involved in anger processing, to detect the effect of increasing provocation by personal insult, and to compare anger-related connectivity patterns between offenders and noncriminal controls (n = 12). During technical frustration, the offenders showed increased neural connectivity between the amygdala and prefrontal cortex compared to the controls. Conversely, personal insults, and thus increased levels of provocation, resulted in a significant reduction of neural connectivity between regions involved in cognitive control in the offenders but not controls. We conclude that, when (nonsocially) frustrated, offenders were able to employ regulatory brain networks by displaying stronger connectivity between regulatory prefrontal and limbic regions than noncriminal controls. In addition, offenders seemed particularly sensitive to personal insults, which led to increased implicit aggression (by means of motoric responses) and reduced connectivity in networks involved in cognitive control (including dorsomedial prefrontal cortex, precuneus, middle/superior temporal regions).

Femcel Discussions of Sex, Frustration, Power, and Revenge.

Although male incels have received a great deal of scholarly attention in recent years, there has been almost no research on femcels (involuntarily celibate women). After collecting data from more than 24,000 femcel posts, we drew from a recently developed sexual frustration theory and conducted qualitative analyses of approximately 1200. Overall, our findings suggest that (1) femcels struggled with multiple types of sexual frustration; (2) they frequently discussed the gender dynamics of both sex and power; (3) they were more interested in their own frustrations than men's frustrations; and (4) despite some notable exceptions, they exhibited less support for aggression, violence, and crime than what has been reported about male incels. Although some femcels referenced their anger, hatred, or desires for revenge, this antipathy may have been rooted in their concerns about how to find a suitable intimate partner while avoiding the threat women often face from violent men. Despite this challenge, most femcels who wanted to enhance their situation or increase their power sought to do so through legal means (e.g., self-improvement, group mobilization, or challenging the patriarchy) and did not express violent intent. Further research on femcels, and the evidence-based strategies that could help them, would be a significant contribution to society.

Geometric frustration produces long-sought Bose metal phase of quantum matter.

Two of the most prominent phases of bosonic matter are the superfluid with perfect flow and the insulator with no flow. A now decades-old mystery unexpectedly arose when experimental observations indicated that bosons could organize into the formation of an entirely different intervening third phase: the Bose metal with dissipative flow. The most viable theory for such a Bose metal to date invokes the use of the extrinsic property of impurity-based disorder; however, a generic intrinsic quantum Bose metal state is still lacking. We propose a universal homogeneous theory for a Bose metal in which geometric frustration confines the essential quantum coherence to a lower dimension. The result is a gapless insulator characterized by dissipative flow that vanishes in the low-energy limit. This failed insulator exemplifies a frustration-dominated regime that is only enhanced by additional scattering sources at low energy and therefore produces a Bose metal that thrives under realistic experimental conditions.

Magnetically driven short-range order can explain anomalous measurements in CrCoNi.

The presence, nature, and impact of chemical short-range order in the multi-principal element alloy CrCoNi are all topics of current interest and debate. First-principles calculations reveal that its origins are fundamentally magnetic, involving repulsion between like-spin Co-Cr and Cr-Cr pairs that is complemented by the formation of a magnetically aligned sublattice of second-nearest-neighbor Cr atoms. Ordering models following these principles are found to predict otherwise anomalous experimental measurements concerning both magnetization and atomic volumes across a range of compositions. In addition to demonstrating the impact of magnetic interactions and resulting chemical rearrangement, the possible explanation of experiments would imply that short-range order of this type is far more prevalent than previously realized.

Entropic barrier of topologically immobilized DNA in hydrogels.

The single most intrinsic property of nonrigid polymer chains is their ability to adopt enormous numbers of chain conformations, resulting in huge conformational entropy. When such macromolecules move in media with restrictive spatial constraints, their trajectories are subjected to reductions in their conformational entropy. The corresponding free energy landscapes are interrupted by entropic barriers separating consecutive spatial domains which function as entropic traps where macromolecules can adopt their conformations more favorably. Movement of macromolecules by negotiating a sequence of entropic barriers is a common paradigm for polymer dynamics in restrictive media. However, if a single chain is simultaneously trapped by many entropic traps, it has recently been suggested that the macromolecule does not undergo diffusion and is localized into a topologically frustrated dynamical state, in apparent violation of Einstein's theorem. Using fluorescently labeled λ-DNA as the guest macromolecule embedded inside a similarly charged hydrogel with more than 95% water content, we present direct evidence for this new state of polymer dynamics at intermediate confinements. Furthermore, using a combination of theory and experiments, we measure the entropic barrier for a single macromolecule as several tens of thermal energy, which is responsible for the extraordinarily long extreme metastability. The combined theory-experiment protocol presented here is a determination of single-molecule entropic barriers in polymer dynamics. Furthermore, this method offers a convenient general procedure to quantify the underlying free energy landscapes behind the ubiquitous phenomenon of movement of single charged macromolecules in crowded environments.

Droplet tilings for rapid exploration of spatially constrained many-body systems.

Geometry in materials is a key concept which can determine material behavior in ordering, frustration, and fragmentation. More specifically, the behavior of interacting degrees of freedom subject to arbitrary geometric constraints has the potential to be used for engineering materials with exotic phase behavior. While advances in lithography have allowed for an experimental exploration of geometry on ordering that has no precedent in nature, many of these methods are low throughput or the underlying dynamics remain difficult to observe directly. Here, we introduce an experimental system that enables the study of interacting many-body dynamics by exploiting the physics of multidroplet evaporation subject to two-dimensional spatial constraints. We find that a high-energy initial state of this system settles into frustrated, metastable states with relaxation on two timescales. We understand this process using a minimal dynamical model that simulates the overdamped dynamics of motile droplets by identifying the force exerted on a given droplet as being proportional to the two-dimensional vapor gradients established by its neighbors. Finally, we demonstrate the flexibility of this platform by presenting experimental realizations of droplet-lattice systems representing different spin degrees of freedom and lattice geometries. Our platform enables a rapid and low-cost means to directly visualize dynamics associated with complex many-body systems interacting via long-range interactions. More generally, this platform opens up the rich design space between geometry and interactions for rapid exploration with minimal resources.

Non-Fermi liquid behavior below the Néel temperature in the frustrated heavy fermion magnet UAu2.

The term Fermi liquid is almost synonymous with the metallic state. The association is known to break down at quantum critical points (QCPs), but these require precise values of tuning parameters, such as pressure and applied magnetic field, to exactly suppress a continuous phase transition temperature to the absolute zero. Three-dimensional non-Fermi liquid states, apart from superconductivity, that are unshackled from a QCP are much rarer and are not currently well understood. Here, we report that the triangular lattice system uranium diauride (UAu2) forms such a state with a non-Fermi liquid low-temperature heat capacity [Formula: see text] and electrical resistivity [Formula: see text] far below its Néel temperature. The magnetic order itself has a novel structure and is accompanied by weak charge modulation that is not simply due to magnetostriction. The charge modulation continues to grow in amplitude with decreasing temperature, suggesting that charge degrees of freedom play an important role in the non-Fermi liquid behavior. In contrast with QCPs, the heat capacity and resistivity we find are unusually resilient in magnetic field. Our results suggest that a combination of magnetic frustration and Kondo physics may result in the emergence of this novel state.

Provoked and unprovoked aggression in toddlerhood: Evaluating measurement invariance and latent means across gender, age, and time.

This paper re-examined the factor structure of a recently developed parent report of aggression, the Provoked and Unprovoked Aggression Questionnaire, and evaluated measurement invariance and latent mean differences across gender, age, and time. Participants were 333 mothers of toddlers (younger age group: n = 167, 53.9% boys, Mage Time 1 = 18.30 months, SD = 0.45; older age group: n = 166, 48.8% boys, Mage Time 1 = 24.29 months, SD = 0.38) who filled out provoked (eight items) and unprovoked (five items) aggression scales twice over a 3-month period. We found evidence for the configural, metric, and scalar measurement invariance-a requirement needed to make a meaningful comparison between aggression means across gender, age groups, and time. When comparing means for boys and girls, gender differences emerged earlier for unprovoked than provoked aggression. Also, the frequency of provoked aggression increased among younger, but not older, toddlers. By developing a brief parental report of aggression in toddlerhood, we hope to fill a void of early aggression measures that tap the contextual variability in aggressive behaviors, and thereby stimulate more research to further our understanding of different types of aggression and their correlates in toddlerhood.

Time-dependent relations between emotion regulation, frustration, and metacognitive strategy use in technology-mediated learning.

Understanding how learners regulate their emotions and engage in metacognitive strategies is crucial for fostering self-regulated learning, particularly in technology-mediated learning. This study examines the temporal relationships between two emotion regulation (ER) strategies, reappraisal and suppression, frustration, and use of progress monitoring as metacognitive strategy, within the context of an educational game on financial literacy. The study involved 82 undergraduate students whose levels of frustration, progress monitoring behaviour, ER strategies were assessed at various points during the learning task. Findings revealed that the use of both reappraisal and suppression decreased during the learning task. Additionally, both ER strategies were negatively associated with frustration, although the relationship between reappraisal and frustration diminished over time. Frustration was negatively related to progress monitoring, indicating that effective emotion regulation can help maintain engagement in metacognitive strategies by keeping cognitive resources available. Notably, suppression and progress monitoring showed a positive relation that increased over time, highlighting the potential usefulness of suppression in extended learning tasks, despite its generally lower effectiveness compared to reappraisal. The results highlight the importance of considering temporal dynamics in the application of ER strategies during extended learning. Practical implications for the design of technology-mediated learning environments and educational interventions are proposed.

Feeding behaviour related to different feeding devices.

Slow feeding devices (SFDs) are useful tools in order to improve the horse well-being and to reduce wastage, but their use may result in unnatural posture during feeding and frustration behaviours. Moreover, it may be important to evaluate the laterality during feeding. The aim of the study was to investigate ponies' feeding behaviour (i.e., lateralisation, frustration, postural eating style) with different hay feeding methods: on the ground (G), a fully filled hay net (HF), a partially filled hay net (HL), and a slow feeder hay box (HB). Nine ponies of two different breed types (Shetland and Welsh/Cob) were evaluated. Video recordings were obtained and then behavioural analysis was conducted. Data were analysed statistically using k-means cluster analysis, repeated measurement mixed model procedure, principal component analysis (PCA) and Pearson's correlation coefficient. Head tilting was more often performed during feeding from HF and HL compared to G and HB. Forelimb forward, referring to the position that ponies assumed during feeding, was performed less frequently with the hay nets. Ponies, in particular Welsh/Cobs, tended to be more left-lateralized and performed more backward ears when feeding from the hay nets. Blink rate was observed to be greater when ponies were fed from G. No head pushing, striking with forelimb and pawing while feeding was seen. Animals fed from HF tended to eat from the top of the hay net and consequently showed an arched neck; while HL and HB showed for elongated neck an intermediate pattern between G and HF. From our results, HB seemed to be a useful compromise between natural feeding on the ground and the use of hay nets.

Prepartum and postpartum mothers' and fathers' feelings of frustration in response to infant crying.

In this cross-sectional study performed in Canada, we evaluated the frustration levels of prepartum and postpartum mother and father couple-pairs. Our goal was to determine if there were differences in frustration levels between mothers and fathers while listening to prolonged infant crying, and further, how frustration levels might differ between prepartum and postpartum samples. Using two discrete groups, prepartum (Sample 1; N = 48) and postpartum (Sample 2; N = 44) mother and father couple-pairs completed 600 s of listening to audio-recorded infant cry sounds. Participants continuously reported their subjective frustration using a computerized Continuous Visual Analog Scale (CVAS). There was no significant difference in frustration responses between mothers and fathers across both prepartum and postpartum samples. Postpartum mothers and fathers experienced greater frustration than their prepartum counterparts, and frustration increased faster in postpartum couples compared to prepartum couples. Informing first-time parents of the universal experiences of frustration to prolonged crying bouts that are characteristic of their infant's early weeks of life may lead to greater understanding towards their infant, and perhaps decreased instances of harmful responses.

En este estudio transeccional, evaluamos los niveles de frustración de las parejas de mamás y papás antes y después del parto. Nuestro propósito fue determinar si hay diferencias entre mamás y papás en cuanto a los niveles de frustración mientras escuchan el prolongado llanto del infante, y cómo los niveles de frustración pudieran diferir entre grupos­muestra antes y después del parto. Usando dos grupos discretos, antes del parto (grupo­muestra 1; N = 48) y después del parto (grupo­muestra 2; N = 44), las parejas de mamás y papás completaron 600 segundos escuchando sonidos grabados en audio de llanto de infante. Los participantes continuamente reportaron su frustración subjetiva usando una escala análoga visual continua computarizada (CVAS). No hubo diferencia significativa en las respuestas de frustración entre mamás y papás a lo largo de los grupos­muestra tanto antes del parto como después del parto. Las mamás y papás en el grupo­muestra después del parto experimentaron mayor frustración que sus homólogos en el grupo­muestra antes del parto, y la frustración aumentó más rápido en las parejas del grupo­muestra después del parto tal como se les comparó con las parejas del grupo­muestra antes del parto. Estos resultados sugieren que las parejas primíparas posterior al parto están más propensas a experimentar considerables cantidades de frustración como respuesta al llanto del infante después que el bebé ha nacido. Informarles a los progenitores primerizos acerca de las experiencias generales de la frustración a los prolongados ataques de llanto que son característicos de las primeras semanas de vida de su infante pudiera llevar a una mayor comprensión hacia su infante y quizás disminuir las instancias de respuestas dañinas.

Dans cette étude transversale nous avons évalué les niveaux de frustration des couples­paires mère et père avant et après la naissance. Notre but était de déterminer s'il existe des différences entres les mères et les pères dans leurs niveaux de frustration en entendant des pleurs de bébé prolongés et de quelle manière les niveaux pourraient différer entre les échantillons avant la naissance et après la naissance. En utilisant deux groupes discrets, avant la naissance (Echantillon 1; N = 48) et après la naissance (Echantillon 2; N = 44) les couples­paires mère et père ont écouté 600 seconds d'enregistrements de pleurs de bébés. Les participants ont fait état de leur frustration subjective en utilisant une échelle analogique visuelle continue informatisée (CVAS). Il s'est avéré n'y avoir aucune différence importante dans les réactions de frustration entre les mères et les pères au travers des échantillons à la fois avant l'accouchement et après l'accouchement. Ces résultats suggèrent que les coupes postpartum primipares sont plus à même de faire l'expérience de niveaux élevés de frustration en réaction aux pleurs du bébé une fois le bébé arrivé. Informer les parents qui sont parents pour la première fois des expériences universelles de frustration aux crises de pleurs prolongées qui caractérisent les premières semaines de la vie des bébés peut mener à une plus grande compréhension de leur bébé et peut­être à une baisse des case d réactions néfastes.

Measurement of basic psychological needs for physical activity participation for college students with intellectual disabilities: A validation study.

BACKGROUND: Measurement instruments to understand self-determined motivation towards physical activity among college students with intellectual disabilities are needed to develop programs to support physical and psychological health and well-being. The purpose of the current study was to validate a modified questionnaire measuring basic psychological needs towards physical activity among college students with intellectual disabilities. METHODS: A total of 108 college students with intellectual disabilities completed the modified questionnaire. Validity and reliability of the questionnaire was examined. RESULTS: Confirmatory factor analysis demonstrated a six-factor model had good model fit. Cronbach's alpha values showed acceptable reliability evidence of the instrument as a whole, although some alpha values in subdomains of the instrument were below acceptable values. CONCLUSION: The modified questionnaire was found to have acceptable validity evidence. Further studies are needed with refinement of answer options and the addition of more questions to increase reliability.