Morphological Cues Research Articles

A Janus, robust, biodegradable bacterial cellulose/Ti3C2Tx MXene bilayer membranes for guided bone regeneration

Guided bone regeneration (GBR) stands as an essential modality for craniomaxillofacial bone defect repair, yet challenges like mechanical weakness, inappropriate degradability, limited bioactivity, and intricate manufacturing of GBR membranes hindered the clinical efficacy. Herein, we developed a Janus bacterial cellulose(BC)/MXene membrane through a facile vacuum filtration and etching strategy. This Janus membrane displayed an asymmetric bilayer structure with interfacial compatibility, where the dense layer impeded cell invasion and the porous layer maintained stable space for osteogenesis. Incorporating BC with Ti3C2Tx MXene significantly enhanced the mechanical robustness and flexibility of the material, enabling clinical operability and lasting GBR membrane supports. It also contributed to a suitable biodegradation rate, which aligned with the long-term bone repair period. After demonstrating the desirable biocompatibility, barrier role, and osteogenic capability in vitro, the membrane's regenerative potential was also confirmed in a rat cranial defect model. The excellent bone repair performance could be attributed to the osteogenic capability of MXene nanosheets, the morphological cues of the porous layer, as well as the long-lasting, stable regeneration space provided by the GBR membrane. Thus, our work presented a facile, robust, long-lasting, and biodegradable BC/MXene GBR membrane, offering a practical solution to craniomaxillofacial bone defect repair.

Cognitive Strategies of Second Language Vocabulary Inferencing: An Eye Tracking Study

In contextual vocabulary acquisition, second language learners address both morphological and contextual cues to infer the meanings of novel words. The study investigated cognitive strategies and their eye movement correlates in contextual vocabulary inferencing task. A sample of 30 healthy participants with normal or corrected to normal vision read an Intermediate-level text in English, aiming to define the meaning of 10 low-frequency words embedded in the text. Based on both unstructured and structured post-hoc reports, we attributed the inferencing process either to word-level processing, context-level processing, or discourse-level processing strategy. Eye movements were recorded on the target word and on the target word clause areas of interest. Inferencing success was associated with increased first fixation duration on the target word both for word- and context-level processing strategy, and increased dwell time on the target word clause for context-level processing strategy. Our findings emphasize the role of both morphological and contextual processing in vocabulary inferencing task.

Adult L2 learners’ morphological sensitivity in a morphosyllabic language

Abstract This study examined adult L2 learners’ morphological sensitivity in Chinese, a morphosyllabic language, and explored whether there is any modulating effects of L2 proficiency. Two word naming experiments (segment shifting and standard word naming) were administered to three participant groups, including native Chinese speakers, higher L2 Chinese proficiency learners, and lower L2 Chinese proficiency learners. In both experiments, reaction times (RTs) displayed only main effects of Chinese proficiency group and word type. This suggests that the morphological processing of L2 learners did not differ from that of native speakers, although the RTs of L2 learners were longer and exhibited more variability. Concerning error rates, both experiments showed that learners with higher and lower L2 proficiency had significantly higher error rates for words with unreliable morphological cues compared to those with reliable cues. Taken together, these findings indicate that L2 learners developed sensitivity to intraword morphological structure and employed decompositional strategies when reading Chinese words, irrespective of their L2 proficiency levels.

Artificial intelligence for human gunshot wound classification

Certain features are helpful in the identification of gunshot entrance and exit wounds, such as the presence of muzzle imprints, peripheral tears, stippling, bone beveling, and wound border irregularity. Some cases are less straightforward and wounds can thus pose challenges to an emergency room doctor or forensic pathologist. In recent years, deep learning has shown promise in various automated medical image classification tasks.This study explores the feasibility of using a deep learning model to classify entry and exit gunshot wounds in digital color images. A collection of 2418 images of entrance and exit gunshot wounds were procured. Of these, 2028 entrance and 1314 exit wounds were cropped, focusing on the area around each gunshot wound. A ConvNext Tiny deep learning model was trained using the Fastai deep learning library, with a train/validation split ratio of 70/30, until a maximum validation accuracy of 92.6% was achieved. An additional 415 entrance and 293 exit wound images were collected for the test (holdout) set. The model achieved an accuracy of 87.99%, precision of 83.99%, recall of 87.71%, and F1-score 85.81% on the holdout set. Correctly classified were 88.19% of entrance wounds and 87.71% of exit wounds. The results are comparable to what a forensic pathologist can achieve without other morphologic cues. This study represents one of the first applications of artificial intelligence to the field of forensic pathology. This work demonstrates that deep learning models can discern entrance and exit gunshot wounds in digital images with high accuracy.

Machine learning identification of Pseudomonas aeruginosa strains from colony image data.

When grown on agar surfaces, microbes can produce distinct multicellular spatial structures called colonies, which contain characteristic sizes, shapes, edges, textures, and degrees of opacity and color. For over one hundred years, researchers have used these morphology cues to classify bacteria and guide more targeted treatment of pathogens. Advances in genome sequencing technology have revolutionized our ability to classify bacterial isolates and while genomic methods are in the ascendancy, morphological characterization of bacterial species has made a resurgence due to increased computing capacities and widespread application of machine learning tools. In this paper, we revisit the topic of colony morphotype on the within-species scale and apply concepts from image processing, computer vision, and deep learning to a dataset of 69 environmental and clinical Pseudomonas aeruginosa strains. We find that colony morphology and complexity under common laboratory conditions is a robust, repeatable phenotype on the level of individual strains, and therefore forms a potential basis for strain classification. We then use a deep convolutional neural network approach with a combination of data augmentation and transfer learning to overcome the typical data starvation problem in biological applications of deep learning. Using a train/validation/test split, our results achieve an average validation accuracy of 92.9% and an average test accuracy of 90.7% for the classification of individual strains. These results indicate that bacterial strains have characteristic visual 'fingerprints' that can serve as the basis of classification on a sub-species level. Our work illustrates the potential of image-based classification of bacterial pathogens and highlights the potential to use similar approaches to predict medically relevant strain characteristics like antibiotic resistance and virulence from colony data.

Improving the acceptability of social robots: Make them look different from humans.

The social robots market will grow considerably in the coming years. What the arrival of these new kind of social agents means for society, however, is largely unknown. Existing cases of robot abuse point to risks of introducing such artificial social agents (ASAs) without considerations about consequences (risks for the robots and the human witnesses to the abuse). We believe that humans react aggressively towards ASAs when they are enticed into establishing dominance hierarchies. This happens when there is a basis for skill comparison. We therefore presented pairs of robots on which we varied similarity and the degree of stimulatability of their mechanisms/functions with the human body (walking, jumping = simulatable; rolling, floating = non-simulatable). We asked which robot (i) resembled more a human, (ii) possessed more "essentialized human qualities" (e.g. creativity). To estimate social acceptability, participants had also (iii) to predict the outcome of a situation where a robot approached a group of humans. For robots with simulatable functions, rating of essentialized human qualities decreased as human resemblance decreased (jumper < walker). For robots with non-simulable functions, the reversed relation was seen: robots that least resembled humans (floater) scored highest in qualities. Critically, robot's acceptability followed ratings of essentialized human qualities. Humans respond socially to certain morphological (physical aspects) and behavioral cues. Therefore, unless ASAs perfectly mimic humans, it is safer to provide them with mechanisms/functions that cannot be simulated with the human body.

Form to meaning mapping and the impact of explicit morpheme combination in novel word processing

In the present study, we leveraged computational methods to explore the extent to which, relative to direct access to semantics from orthographic cues, the additional appreciation of morphological cues is advantageous while inducing the meaning of affixed pseudo-words. We re-analyzed data from a study on a lexical decision task for affixed pseudo-words. We considered a parsimonious model only including semantic variables (namely, semantic neighborhood density, entropy, magnitude, stem proximity) derived through a word-form-to-meaning approach (ngram-based). We then explored the extent to which the addition of equivalent semantic variables derived by combining semantic information from morphemes (combination-based) improved the fit of the statistical model explaining human data. Results suggest that semantic information can be extracted from arbitrary clusters of letters, yet a computational model of semantic access also including a combination-based strategy based on explicit morphological information better captures the cognitive mechanisms underlying human performance. This is particularly evident when participants recognize affixed pseudo-words as meaningful stimuli.

In Situ Fabrication of Constraints for Multicellular Micro‐Spheroids Using Two‐Photon Lithography

Abstract2‐photon polymerization is a promising technology for creating complex, microscale 3D matrices for biomedical and also bioprinting applications. Cancer research provides compelling uses for this strategy, in particular, for generating a 3D constraint around multicellular spheroids. Because these spheroids are inhomogeneous in size and shape, the ability to target a spheroid composed of a few living cells requires geometrical control of the printing shape in situ. In this study, it is presented that two‐photon lithography can be used to study complex phenomena involved in cancer progression, such as collective 3D cell migration in situ in vitro. This method allows the spatial and temporal control of cancer cell migration from single spheroids, using dome‐shaped confinements with micrometer‐sized openings. The confinement of the spheroids leads to a decreased migration speed and affects actin dynamics. Furthermore, this methodology provides a novel way of analyzing the behavior of specific regions of multicellular structures, by enabling the separation of multicellular structures, while keeping them alive. Ultimately, this study demonstrates a new way to use two‐photon lithography for controlling the growth, migration and morphological cues of live cells, thus opening new avenues toward the dynamic in situ control of living 3D structures.

Biomimetic Electrospun Scaffold-Based In Vitro Model Resembling the Hallmarks of Human Myocardial Fibrotic Tissue.

Adverse remodeling post-myocardial infarction is hallmarked by the phenotypic change of cardiac fibroblasts (CFs) into myofibroblasts (MyoFs) and over-deposition of the fibrotic extracellular matrix (ECM) mainly composed by fibronectin and collagens, with the loss of tissue anisotropy and tissue stiffening. Reversing cardiac fibrosis represents a key challenge in cardiac regenerative medicine. Reliable in vitro models of human cardiac fibrotic tissue could be useful for preclinical testing of new advanced therapies, addressing the limited predictivity of traditional 2D cell cultures and animal in vivo models. In this work, we engineered a biomimetic in vitro model, reproducing the morphological, mechanical, and chemical cues of native cardiac fibrotic tissue. Polycaprolactone (PCL)-based scaffolds with randomly oriented fibers were fabricated by solution electrospinning technique, showing homogeneous nanofibers with an average size of 131 ± 39 nm. PCL scaffolds were then surface-functionalized with human type I collagen (C1) and fibronectin (F) by dihydroxyphenylalanine (DOPA)-mediated mussel-inspired approach (PCL/polyDOPA/C1F), in order to mimic fibrotic cardiac tissue-like ECM composition and support human CF culture. BCA assay confirmed the successful deposition of the biomimetic coating and its stability during 5 days of incubation in phosphate-buffered saline. Immunostaining for C1 and F demonstrated their homogeneous distribution in the coating. AFM mechanical characterization showed that PCL/polyDOPA/C1F scaffolds, in wet conditions, resembled fibrotic tissue stiffness with an average Young's modulus of about 50 kPa. PCL/polyDOPA/C1F membranes supported human CF (HCF) adhesion and proliferation. Immunostaining for α-SMA and quantification of α-SMA-positive cells showed HCF activation into MyoFs in the absence of a transforming growth factor β (TGF-β) profibrotic stimulus, suggesting the intrinsic ability of biomimetic PCL/polyDOPA/C1F scaffolds to sustain the development of cardiac fibrotic tissue. A proof-of-concept study making use of a commercially available antifibrotic drug confirmed the potentialities of the developed in vitro model for drug efficacy testing. In conclusion, the proposed model was able to replicate the main hallmarks of early-stage cardiac fibrosis, appearing as a promising tool for future preclinical testing of advanced regenerative therapies.

Differences between stereotypical gender and definitional gender in pronominal antecedent retrieval in Brazilian Portuguese

Together with Alves (2019), this paper is part of a research work dedicated to investigating the role of gender cues in pronominal antecedent retrieval in Brazilian Portuguese. The main aim is to determine whether Principle B structural constraints work as an initial filter in pronominal antecedent retrieval in Brazilian Portuguese, or whether gender cues play a major role at early processing phases since this language has visible redundant morphological markings. It is also examined whether antecedent candidates carrying different gender cues have different weights in memory. In the present work, a comparison between antecedent candidates carrying stereotypical gender and definitional gender was provided. The results of two eye-tracking experiments conducted with native speakers of Brazilian Portuguese showed that gender morphological cues play a role at the very beginning of pronoun resolution processing, and only at a later processing phase, structural constraints of Principle B seemed to help the parser to select the correct antecedent. Like the previous work, the results indicated Principle B structural constraints do not work as an initial filter blocking structurally unacceptable candidates in Brazilian Portuguese; on the contrary, all candidates seemed to be taken into account despite of violating Principle B structural constraints. Similarly to the previous work, masculine antecedent candidates were preferable to be retrieved by memory in comparison to feminine candidates. Moreover, the results indicated that candidates with definitional gender rather than stereotypical gender are preferable to be retrieved by memory since the former is lexically specified, while the latter relies on probabilities based on world knowledge inferences.

Terahertz imaging of human skin pathologies using laser feedback interferometry with quantum cascade lasers.

Early detection of skin pathologies with current clinical diagnostic tools is challenging, particularly when there are no visible colour changes or morphological cues present on the skin. In this study, we present a terahertz (THz) imaging technology based on a narrow band quantum cascade laser (QCL) at 2.8 THz for human skin pathology detection with diffraction limited spatial resolution. THz imaging was conducted for three different groups of unstained human skin samples (benign naevus, dysplastic naevus, and melanoma) and compared to the corresponding traditional histopathologic stained images. The minimum thickness of dehydrated human skin that can provide THz contrast was determined to be 50 µm, which is approximately one half-wavelength of the THz wave used. The THz images from different types of 50 µm-thick skin samples were well correlated with the histological findings. The per-sample locations of pathology vs healthy skin can be separated from the density distribution of the corresponding pixels in the THz amplitude-phase map. The possible THz contrast mechanisms relating to the origin of image contrast in addition to water content were analyzed from these dehydrated samples. Our findings suggest that THz imaging could provide a feasible imaging modality for skin cancer detection that is beyond the visible.

Biomimetic Extracellular Scaffolds by Microfluidic Superstructuring of Nanofibers.

The extracellular matrix is a dynamic framework bearing chemical and morphological cues that support many cellular functions, and artificial analogs with well-defined chemistry are of great interest for biomedical applications. Herein, we describe hierarchical, extracellular-matrix-mimetic microgels, termed "superbundles" (SBs) composed of peptide amphiphile (PA) supramolecular nanofiber networks created using flow-focusing microfluidic devices. We explore the effects of altered flow rate ratio and PA concentration on the ability to create SBs and develop design rules for producing SBs with both cationic and anionic PA nanofibers and gelators. We demonstrate the morphological similarities of SBs to decellularized extracellular matrices and showcase their ability to encapsulate and retain proteinaceous cargos with a wide variety of isoelectric points. Finally, we demonstrate that the novel SB morphology does not affect the well-established biocompatibility of PA gels.

Methylcellulose/agarose hydrogel loaded with short electrospun PLLA/laminin fibers as an injectable scaffold for tissue engineering/3D cell culture model for tumour therapies

This research aimed at designing and fabricating a smart thermosensitive injectable methylcellulose/agarose hydrogel system loaded with short electrospun bioactive PLLA/laminin fibers as a scaffold for tissue engineering applications or 3D cell culture models. Considering ECM-mimicking morphology and chemical composition, such a scaffold is capable of ensuring a hospitable environment for cell adhesion, proliferation, and differentiation. Its viscoelastic properties are beneficial from the practical perspective of minimally invasive materials that are introduced to the body via injection. Viscosity studies showed the shear-thinning character of MC/AGR hydrogels enabling the potential injection ability of highly viscous materials. Injectability tests showed that by tuning the injection rate, even a high amount of short fibers loaded inside of hydrogel could be efficiently injected into the tissue. Biological studies showed the non-toxic character of composite material with excellent viability, attachment, spreading, and proliferation of fibroblasts and glioma cells. These findings indicate that MC/AGR hydrogel loaded with short PLLA/laminin fibers is a promising biomaterial for both tissue engineering applications and 3D tumor culture models.

Lordosis in humans: women's accurate perceptions of men's context-dependent preferences

Semchenko and colleagues (in press) recently disentangled two evolutionary hypotheses and demonstrated that heterosexual men have mate preferences for both the morphological cue of women's lumbar curvature and the behavioral cue of back arching: Men are attracted to an intermediate degree of lumbar curvature in both short-term and long-term mating contexts, and, independent of this preference, are attracted to lordosis behavior in short-term, but not long-term, mating contexts. No research to date has investigated whether women are aware of these preferences. There are a priori reasons to expect this to be the case: An awareness of these preferences could functionally guide both appearance-enhancement and intrasexual competition strategies. Here, we tested whether women have accurate perceptions of men's preferences in the lumbar region. Across two studies (Ns = 177, 293), we found that women's perceptions align precisely with men's preferences: Women perceive men to be attracted to cues to lordosis behavior in short-term but not long-term contexts, and to be attracted to an intermediate angle of lumbar curvature independent of mating context. We hope these findings, which document previously unknown features of women's mating psychology, inspire investigations into how women might adaptively use their accurate perceptions of men's mate preferences.

Lordosis in Humans.

Despite progress in attractiveness research, we have yet to identify many fitness-relevant cues in the human phenotype or humans' psychology for responding to them. Here, we test hypotheses about psychological systems that may have evolved to process distinct cues in the female lumbar region. The Fetal Load Hypothesis proposes a male preference for a morphological cue: lumbar curvature. The Lordosis Detection Hypothesis posits context-dependent male attraction to a movement: lordosis behavior. In two studies (Study 1 N: 102, Study 2 N: 231), we presented men with animated female characters that varied in their lumbar curvature and back arching (i.e., lordosis behavior). Irrespective of mating context, men's attraction increased as lumbar curvature approached the hypothesized optimum. By contrast, men experienced greater attraction to lordosis behavior in short-term than long-term mating contexts. These findings support both the Lordosis Detection and Fetal Load Hypotheses. Discussion focuses on the meaning of human lordosis and the importance of dynamic stimuli in attractiveness research.

From the Viscera to First Impressions: Phase-Dependent Cardio-Visual Signals Bias the Perceived Trustworthiness of Faces

When we see new people, we rapidly form first impressions. Whereas past research has focused on the role of morphological or emotional cues, we asked whether transient visceral states bias the impressions we form. Across three studies (N = 94 university students), we investigated how fluctuations of bodily states, driven by the interoceptive impact of cardiac signals, influence the perceived trustworthiness of faces. Participants less often chose faces presented in synchrony with their own cardiac systole as more trustworthy than faces presented out of synchrony. Participants also explicitly judged faces presented in synchrony with their cardiac systole as less trustworthy. Finally, the presentation of faces in synchrony with participants’ cardiac diastole did not modulate participants’ perceptions of the faces’ trustworthiness, suggesting that the systolic phase is necessary for such interoceptive effects. These findings highlight the role of phasic interoceptive information in the processing of social information and provide a mechanistic account of the role of visceroception for social perception.

Doubling up: The Influence of Native and Foreign Language Cues in Foreign Language Double Consonant Spelling

In this study, we investigated which spelling cues are used in word-medial consonant spelling by learners of English as a Foreign Language (EFL). Previous research has shown that native speakers of English rely on different cues to decide whether a single (“diner”) or double consonant (“dinner”) needs to be used in word-medial consonant spelling. These cues include phonology, orthography, morphology and lexical frequency. We investigated whether these cues play a similar role in Dutch spellers who are EFL learners, next to similarity of the English target to Dutch. We analyzed dictation task data that was part of an unsupervised digital learning environment for EFL learning. The error analyses revealed that novice EFL spellers mainly used phonological and cross-linguistic cues in consonant doubling. In contrast, more proficient spellers relied less on phonological cues, and relied on morphological cues instead. The EFL spellers did not rely on orthographic cues. Furthermore, spelling difficulty was influenced by the frequency of a word and its similarity with the native-language equivalent, in terms of cognate status (non-cognate/cognate) and consonant doubling. Together, our findings indicate that a higher number of converging cues facilitates spelling for EFL spellers and that their reliance on cues changes as spelling proficiency increases.

Assessing the roles of collagen fiber morphology and matrix stiffness on ovarian cancer cell migration dynamics using multiphoton fabricated orthogonal image-based models

Ovarian cancer remains the deadliest of the gynecological cancers, where this arises from poor screening and imaging tools that can detect early disease, and also limited understanding of the structural and functional aspects of the tumor microenvironment. To gain insight into the underlying cellular dynamics, we have used multiphoton excited fabrication to create Second Harmonic Generation (SHG) image-based orthogonal models from collagen/GelMA that represent both the collagen matrix morphology and stiffness (∼2–8 kPa) of normal ovarian stroma and high grade serous ovarian cancers (HGSOC). These scaffolds are used to study migration/cytoskeletal dynamics of normal (IOSE) and ovarian cancer (OVCA433) cell lines. We found that the highly aligned fiber morphology of HGSOC promotes aspects of motility (motility coefficient, motility, and focal adhesion expression) through a contact guidance mechanism and that stiffer matrix further promotes these same processes through a mechanosensitive mechanism, where these trends were similar for both normal and cancer cells. However, cell specific differences were found on these orthogonal models relative to those providing only morphology, showing the importance of presenting both morphology and stiffness cues. Moreover, we found increased cadherin expression and decreased cell alignment only for cancer cells on scaffolds of intermediate modulus suggesting different stiffness-dependent mechanotransduction mechanisms are engaged. This overall approach affords decoupling the roles of matrix morphology, stiffness and cell genotype and affords hypothesis testing of the factors giving rise to disease progression and metastasis. Further, more established fabrication techniques cannot simultaneously reproduce both the 3D collagen fiber morphology and stiffness. Statement of significanceOvarian cancer metastasizes when lesions are small, where cells exfoliate from the surface of the ovary and reattach at distal sites in the peritoneum. The adhesion/migration dynamics are not well understood and there is a need for new 3D in vitro models of the extracellular matrix to study the biology. Here we use multiphoton excited crosslinking to fabricate ECM orthogonal models that represent the collagen morphology and stiffness in human ovarian tissues. These are then used to study ovarian cancer cell migration dynamics and we found that contact guidance and a mechanosensitive response and cell genotype all combine to affect the behavior. These models provide insight into disease etiology and progression not readily possible by other fabrication methods.

Morphological cues as an aid to word learning: a cross-situational word learning study

ABSTRACT Learning a language with complex morphology poses a challenge to language learners, especially adults, who may need to acquire unfamiliar grammatical categories. One possible advantage to languages with complex morphology is that the morphology could provide cues to word meaning. The hypothesis that morphology can bootstrap adult word learning is tested across four cross-situational word learning experiments. Adult learners were exposed to words from a novel language with CVCV stems and -CV suffixes. In the Experimental conditions, the suffixes consistently mapped to semantic categories (e.g. [-ke] for fruits). In the Control condition, the suffixes did not provide any consistent semantic information. Participants in the Experimental conditions outperformed participants in the Control conditions, but only when there were sufficient opportunities to infer the morphology in the initial learning phases. These results highlight adults’ ability to rapidly learn novel morphological information, and use this information in word learning.

Processing of Transitivity Alternations and Frequency-Based Accounts in Greek Adult Language

The processing and resolution of syntactically ambiguous structures is accounted for by serial autonomous and multiple constraint satisfaction models differently. We investigated the extent to which frequency affects native speakers’ processing and interpretation of ‘voice (non)-alternating’ anticausative Greek verbs which differ in the availability or lack of voice alternation on the verb when it appears in intransitive structures. The accessibility of interpretations was measured with an online self-paced reading (SPR) task and an offline acceptability judgment (AJ) task addressed to 45 monolingual Greek-speaking adults. In order to investigate whether processing load is affected by statistical records in the parser, we compared empirical data with the frequency of the available readings that these verbs receive in formal and informal registers (ILSP, Web-Based Corpus). The online processing study indicated that the parser is sensitive to morphological cues ((N)ACT voice marking), while semantic factors such as animacy are integrated in subsequent stages of processing. A frequency effect was found in accordance with ‘coarse-grained’ models of sentence processing, while more ‘fine-grained’ models could not be validated with respect to frequency alone. The majority of acceptability judgements attributed to the verbs investigated correlated with the most frequent interpretations of verb forms in intransitive structures in corpora.