Onset Of Branching Research Articles

Mesenchyme instructs growth while epithelium directs branching in the mouse mammary gland.

The mammary gland is a unique organ that undergoes dynamic alterations throughout a female's reproductive life, making it an ideal model for developmental, stem cell and cancer biology research. Mammary gland development begins in utero and proceeds via a quiescent bud stage before the initial outgrowth and subsequent branching morphogenesis. How mammary epithelial cells transit from quiescence to an actively proliferating and branching tissue during embryogenesis and, importantly, how the branch pattern is determined remain largely unknown. Here, we provide evidence indicating that epithelial cell proliferation and onset of branching are independent processes, yet partially coordinated by the Eda signaling pathway. Through heterotypic and heterochronic epithelial-mesenchymal recombination experiments between mouse mammary and salivary gland tissues and ex vivo live imaging, we demonstrate that unlike previously concluded, the mode of branching is an intrinsic property of the mammary epithelium whereas the pace of growth and the density of ductal tree are determined by the mesenchyme. Transcriptomic profiling and ex vivo and in vivo functional studies in mice disclose that mesenchymal Wnt/ß-catenin signaling, and in particular IGF-1 downstream of it critically regulate mammary gland growth. These results underscore the general need to carefully deconstruct the different developmental processes producing branched organs.

Direct Analysis of Complex Reaction Mixtures: Formose Reaction.

Complex reaction mixtures, like those postulated on early Earth, present an analytical challenge because of the number of components, their similarity, and vastly different concentrations. Interpreting the reaction networks is typically based on simplified or partial data, limiting our insight. We present a new approach based on online monitoring of reaction mixtures formed by the formose reaction by ion-mobility-separation mass-spectrometry. Monitoring the reaction mixtures led to large data sets that we analyzed by non-negative matrix factorization, thereby identifying ion-signal groups capturing the time evolution of the network. The groups comprised ≈300 major ion signals corresponding to sugar-calcium complexes formed during the formose reaction. Multivariate analysis of the kinetic profiles of these complexes provided an overview of the interconnected kinetic processes in the solution, highlighting different pathways for sugar growth and the effects of different initiators on the initial kinetics. Reconstructing the network's topology further, we revealed so far unnoticed fast retro-aldol reaction of ketoses, which significantly affects the initial reaction dynamics. We also detected the onset of sugar-backbone branching for C6 sugars and cyclization reactions starting for C5 sugars. This top-down analytical approach opens a new way to analyze complex dynamic mixtures online with unprecedented coverage and time resolution.

Flow-induced vibration of a cylinder-plate assembly in laminar flow: Branching behavior

The transverse flow-induced vibration of an elastically supported cylinder-plate assembly (viz., a rigid splitter-plate attached to the downstream side of a circular cylinder) with a low mass ratio of 10 and a zero structural damping coefficient at a Reynolds number of 100 is investigated in the present work. A careful identification of all the branches in the amplitude response of an assembly with various plate lengths is undertaken, in conjunction with the associated flow dynamics responsible for these branches involving various aspects of the flow, such as the vortex-shedding in the far wake and the evolution of the shear layers generated on the upper and lower surfaces of the cylinder in the near wake. This knowledge offers crucial new perspectives on the nature and physical mechanisms behind the complex dynamics of a cylinder-plate system. These investigations involve a wide range of plate lengths LSP/D=0–4 (where D is the diameter of the circular cylinder) over an extensive span of reduced velocities Ur = 2–30. For LSP/D≤0.5, a self-limiting oscillation is induced in the structure—this can be either a vortex-induced vibration (VIV) or an integrated VIV-galloping response. For LSP/D≥0.75, the amplitude response is non-limited in the sense that the amplitude increases linearly with increasing Ur. More precisely, the amplitude response consists of either a strongly correlated VIV-galloping regime (at LSP/D=0.75) or two clearly separated regimes of VIV and galloping (for LSP/D>0.75). In the galloping regime, both odd- and even-multiple synchronizations between the system oscillation and the vortex shedding are supported. “Kinks” in the amplitude response signal the onset of synchronization branches in the galloping regime. Two new branches have been identified for a cylinder-plate assembly with longer plate lengths, namely, an initial galloping branch and a still (quiescent) branch. The initial galloping branch is associated with wake meandering. For the still branch, the assembly is stationary (no vibratory motion), and flow over the assembly is steady (no vortex shedding or shear-layer meandering).

The representation of sC-clusters: A Strict CV analysis

sC-clusters have always posed a challenge for theories of phonological representation because they behave like coda-onset clusters, but they can also occur word-initially (where their behaviour typically differs from that of branching onsets comprising an obstruent followed by a sonorant). [s] in such initial clusters has been analysed as an appendix, as a coda, or as part of a complex segment. Out of these possibilities, the coda analysis (where initial [s] is assumed to be preceded by an empty nucleus) is shown to account for the data in the most satisfactory way. However, it faces the problem of how to ensure that this empty nucleus remains silent (called Magic Licensing). Instead, I propose a Strict CV representation of initial sC-clusters, where the melody of [s] is shared by a neighbouring V position, by a language specific choice: in Italian and Portuguese [s] occupies the preceding V position, while in English the following one. As the initial nucleus does not remain empty in this analysis, no special licensing is necessary. I also show that not only is the branching representation of [s] identical to that of syllabic sonorants in this model, their distribution is also parallel. In English, syllabic sonorants branch on the left, while syllabic [s] branches on the right, and the differences in their behaviour follow directly from the difference in the direction of branching. Finally, the marked structure of syllabic consonants is only permitted if without their branching the representation is ill-formed. This means that they must always be flanked by a consonant at least on one side.

Sobre o impacto da constituência silábica na repetição de pseudopalavras: dados preliminares do desenvolvimento típico para a validação do LITMUS-QU-NWR-EP

Nonword repetition is a relevant task in clinical phonological assessment. However, few authors have considered the impact of syllable constituency on child performance in such task. In this study, we analyse the contribution of syllable constituency in nonword repetition through the validation of a new test (LITMUS-QU-NWR-EP) adapted to European Portuguese (EP). Two syllable structures were considered: lateral coda (both in word-medial and word-final position) and branching onsets (obstruent + lateral clusters). Results from typically developing children, aged 5 to 8 years, showed generalized difficulties in both structures, although codas were less problematic than branching onsets. Portuguese child performance contrasts with the data obtained for the French version of the instrument (LITMUS-QU-NWR-FR), given the overall lower performance found for EP, and the preference for codas over branching onsets, unlike attested for French children. A comparative analysis shows that nonword repetition difficulties in what concerns syllabic constituency may be language dependent. Clinical implications for EP are discussed.

Revisiting the Acquisition of Onset Complexity: Affrication in Québec French.

I investigate the acquisition of affrication in Québec French (QF), where affricates are in complementary distribution with coronal stops, being realized before high front vowels and glides. Previous research on other languages shows that affricates are acquired before branching onsets, which supports the idea that complexity at the level of the segment is acquired before complexity at the level of the syllable (Lleó & Prinz, 1997). In contrast, I hypothesize that affricates are acquired after branching onsets in QF, as learners are required to understand the constraints on their distribution. I examine longitudinal data from two QF-speaking children for whom the acquisition of branching onsets has been previously analyzed (Rose, 2000). Results show that affricates are indeed acquired after branching onsets, consistent with the hypothesis. Overapplication errors indicate that children make generalizations about the phonological constraints on affrication from an early age, which is expected for the acquisition of rules.

Branching onsets 2.0

AbstractThis paper proposes a novel representation of branching onsets within the framework of Government Phonology 2. They are argued to be complex onset phrases, where the second member is directly embedded within the first and controls its head. The system predicts that for fricatives, the ability to become the first member of a branching onset depends on their place of articulation. In particular, [s]-like fricatives (S) are predicted to lack this ability, thereby explaining Kaye’s (1992) empirical generalization that SC clusters are never branching onsets.

Positional factors in syllabification

AbstractFrom the perspective of standard generative phonological theory, syllable structure is not recorded in the lexicon but it is obtained by means of a syllabification algorithm based on a series of principles. In a given language, the algorithm should parse obstruent+liquid clusters as tautosyllabic both in word-initial and word-internal positions. The tautosyllabic parse as a branching onset complies with all principles on which the syllable-building algorithm is based. In standard theory, if branching onsets of obstruent+liquid are allowed in a language and documented in word-initial position, tautosyllabic parse is predicted to hold also word-internally. Likewise, Kaye’s (1992) Uniformity Principle makes the same prediction, since it states that sequences of contiguous positions that are in a governing relation and contain the same phonological material have the same constituent structure. The present paper draws attention to empirical data showing obstruent+liquid clusters being parsed tautosyllabically in word-initial position and heterosyllabically in word-internal position in the same language. An account is proposed to explain the data discussed, claiming that positional factors may also be relevant in determining syllabification.

A sílaba na relação com a escrita: ataques ramificados na escrita de crianças dos segundo e quarto anos – um estudo a partir do EFFE-On

The syllable is a unit of the phonological system of human languages that has been the subject of numerous studies in language and language acquisition. Using longitudinal data from the online corpus EFFE-On, this article focuses on the evaluation of children's written performance with respect to the order of acquisition of the syllable structure, in particular the analysis of branching Onsets (obstruent+liquid). The study focuses on the performance of second and fourth graders in the Lisbon area and will allow us to describe the relationship between phonological and orthographic knowledge in children attending the first years of elementary education.

What do monolingual and bilingual children with and without SLI produce when phonology is too complex?

In this study, the authors compare the production of internal codas and branching onsets in four groups of children learning French: monolingual typically-developing children ( n = 12), bilingual typically-developing children ( n = 61), monolingual children with Specific Language Impairment ( n = 17) and bilingual children with Specific Language Impairment ( n = 20). Their elicited productions were collected using a nonword repetition task (LITMUS-NWR-French), containing 71 nonwords with different syllable types. Except for typically-developing monolingual children, all children performed significantly better on branching onsets than on internal codas. Moreover, the repair strategies used in erroneous productions also indicate that children had more difficulties with internal codas: all the cases of metathesis affecting a target internal coda resulted in the production of a branching onset whereas the contrary was not observed. The differences in the rates of target-like production and the patterns of metathesis of these two structures suggest that internal codas are more difficult than branching onsets for children learning French.

On branching onsets in Norwegian

Syllable margins and the phonotactic peculiarities of word-edges have always drawn attention of researches working within different theoretical approaches. In the following paper some Norwegian consonantal clusters will be examined, with special reference to the left-margin of the words. Our attention will be focused on establishing the set of possible branching onsets in Norwegian, both word-initially and in the word-internal position.

Um polvo é igual a um pato? Sobre o impacto das variáveis fonológicas na avaliação do conhecimento metalinguístico

Most tools used to assess phonological awareness (PA) are not controlled from a phonological perspective. However, research available for different languages refers the impact of phonological variables in the assessment of this type of linguistic knowledge. In this paper, we will be focused on the impact of the prosodic variables word length, syllable constituency and word stress in the performance of tasks assessing Portuguese children’s PA. A sample of 49 monolingual and typically developing Portuguese children was gathered (22 first graders and 27 third graders). Three tasks were used to assess syllable awareness (1 segmentation task, 1 identification task, 1 omission task); one segmentation task assessed the children’s segmental awareness; another segmentation task assessed their awareness of syllable constituency. Although some studies report the effect of all prosodic variables mentioned above (see state of the art below), the results in this paper show a significant effect of syllable structure, lexical stimuli with branching onsets and branching rhymes being the most problematic, but no significant effects of word length or word stress. The results are an empirical contribution for the discussion of the aspects that need to be taken in to account to build PA assessment tools and to plan intervention in clinical and in educational contexts

Revisitando a aquisição do ataque ramificado CCV: estágios do desenvolvimento silábico

This article aims to debate about the development stages in the course of acquisition of CCV branching onset syllables (Consonant1 + Consonant2 + Vowel) – structure present in Brazilian Portuguese words like ‘ bru xa’ witch , ‘ blu sa’ blouse , ‘ pra to’ plate , ‘ pla ca’ plaque . Reviewing researches on Brazilian Portuguese as Teixeira (1988), Lamprecht (1993), Avila (2000), Ribas (2002), Staudt (2008), Baesso (2009), this article examines possible motivations for the (non)observation of linguistic development stages in the CCV acquisition by Brazilian children. It is investigated whether such motivations may lie i) a general trend of the phonological acquisition path – as observed in the acquisition of other syllabic structures, like CVC coda; (ii) in the individual development of the subjects; or iii) in methodological effects related to the type of data collection. To verify these motivations, the study analyzes naturalistic data of 3 subjects, recorded biweekly, and experimental data of 49 subjects, recorded in a repetition test of words and pseudowords. The results indicate that the naturalistic data collection can affect the observation of syllabic development stages, since the unbalance of CCV targets and their phonotatic combination may affect the determination of strategies such as lexical selection and the origin/direction of substitutions in CCV. Individual development was observed as correlated with the general phonological tendencies pointed out by Teixeira (1988) and Lamprecht (1993), because these generalizations may act as limits to the different paths possible to the child in CCV acquisition. The study also suggests that the type of strategy used to repair CCV also depends on the child’s syllabic development. --- DOI: http://dx.doi.org/10.12957/matraga.2017.28574

Experimental investigation of crack propagation and crack branching in lightly reinforced concrete beams using digital image correlation

Relatively few fracture-oriented experimental studies have been conducted on concrete that is reinforced. An experimental investigation was therefore undertaken to explore the cracking process in lightly reinforced concrete (RC) beams and to observe the details of the localised fracture process zone development. More specifically, the aims were to investigate the relationships between beam height (120mm, 220mm and 320mm), steel reinforcement ratio (0.1–0.5%), ductility and the onset of crack branching. RC beams were tested in three-point bending and experimental surface strains and crack openings were inferred using digital image correlation (DIC). It was found that the presence of the reinforcement prevented premature fracture and led to crack branching where a single crack bifurcated in the region of the compression zone. In the larger beams the branching developed at a lower relative height and a greater reinforcement ratio led to a shallower branching angle. These observations were associated with ductility measures for lightly reinforced concrete beams.

Footing is Not Always about Stress: Formalizing Variable High Vowel Deletion in Québec French

The existence of foot structure in (Québec) French is disputed, since the only position of obligatory prominence in the language is the right edge of the phonological phrase. In this paper, we propose that a segmental process, namely, high vowel deletion (HVD), supports the existence of iterative iambic footing in Québec French. We report on a judgement task with auditorily-presented stimuli in which native speakers judged whether words with and without HVD sounded natural. The results show that (i) HVD is preferred in even-numbered syllables from the right word edge, (ii) HVD is preferred when the resulting consonantal cluster mirrors an ill-formed branching onset, and (iii) although non-deletion is overall preferred to deletion, deletion is preferred in one context: when the target vowel is at a suffix boundary and in foot-dependent positions.

Parameter setting in the acquisition of consonant clusters by phonologically delayed children

ABSTRACTThe relationship between the acquisition of initial complex onset clusters, /s/-initial clusters, and non-initial clusters is much studied yet poorly understood. Pan and Snyder (2004), working within the Government Phonology (GP) framework, proposed that the production of the three types of consonant clusters requires the proper setting of three binary parameters [+/- Branching onset (BO), [+/-Branching rhyme (BR)] and [+/-Magic empty nucleus (MEN)]. Specifically, the production of onset clusters require [+BO], /s/-initial clusters require both [+BR] and [+MEN], and non-initial clusters require [+BR]. Two predictions follow: (1) The acquisition of /s/-initial clusters is independent of the acquisition of onset clusters, and (2) /s/-initial clusters should never be acquired prior to non-initial clusters, because the latter only require [+BR]. These predictions were borne out by data from twenty English-speaking children with phonological delay (mean age = 4;10). In support of prediction (1), seven children were able to produce onset clusters, but never produced /s/-initial clusters, and four children had the opposite pattern. Consistent with prediction (2), six children produced non-initial clusters but were unable to produce /s/-initial clusters. We conclude that a parametric approach is applicable to the acquisition of consonant clusters in children with phonological delay.

Epênteses nas produções orais e escritas de grupos consonânticos no 1º ciclo do ensino básico

Given the complex nature of Branching Onsets and heterosyllabic consonant clusters, children often resort to repair strategies, which arise from the phonological and orthographic development stage in which they are in. In this paper, we discuss vowel epenthesis strategy. Hence, we examine oral and written productions from 56 European Portuguese monolingual children attending the 1st and 4th grades of two elementary schools in Portugal. Data from this study suggest that there are some wide differences: (i) between the acquisition of branching Onsets and other consonantal clusters, (ii) between oral and writing.

Monopodial and sympodial branching architecture in cotton is differentially regulated by the Gossypium hirsutum SINGLE FLOWER TRUSS and SELF-PRUNING orthologs.

Domestication of upland cotton (Gossypium hirsutum) converted it from a lanky photoperiodic perennial to a day-neutral annual row-crop. Residual perennial traits, however, complicate irrigation and crop management, and more determinate architectures are desired. Cotton simultaneously maintains robust monopodial indeterminate shoots and sympodial determinate shoots. We questioned if and how the FLOWERING LOCUS T/SINGLE FLOWER TRUSS (SFT)-like and TERMINAL FLOWER1/SELF-PRUNING (SP)-like genes control the balance of monopodial and sympodial growth in a woody perennial with complex growth habit. Virus-based manipulation of GhSP and GhSFT expression enabled unprecedented functional analysis of cotton development. GhSP maintains growth in all apices; in its absence, both monopodial and sympodial branch systems terminate precociously. GhSFT encodes a florigenic signal stimulating rapid onset of sympodial branching and flowering in side shoots of wild photoperiodic and modern day-neutral accessions. High florigen concentrations did not alter monopodial apices, implying that once a cotton apex is SP-determined, it cannot be reset by florigen. GhSP is also essential to establish and maintain cambial activity. Dynamic changes in GhSFT and GhSP levels navigate meristems between monopodial and sympodial programs in a single plant. SFT and SP influenced cotton domestication and are ideal targets for further agricultural optimization.

Strain injection techniques in dynamic fracture modeling

A computationally affordable modeling of dynamic fracture phenomena is performed in this study by using strain injection techniques and Finite Elements with Embedded strong discontinuities (E-FEM). In the present research, classical strain localization and strong discontinuity approaches are considered by injecting discontinuous strain and displacement modes in the finite element formulation without an increase of the total number of degrees of freedom. Following the Continuum Strong Discontinuity Approach (CSDA), stress–strain constitutive laws can be employed in the context of fracture phenomena and, therefore, the methodology remains applicable to a wide number of continuum mechanics models. The position and orientation of the displacement discontinuity is obtained through the solution of a crack propagation problem, i.e. the crack path field, based on the distribution of localized strains. The combination of the above mentioned approaches is envisaged to avoid stress-locking and directional mesh bias phenomena.Dynamic simulations are performed increasing the loading rate up to the appearance of crack branching, and the variation in terms of failure modes is investigated as well as the influence of the strain injection together with the crack path field algorithm. Objectivity of the presented methodology with respect to the spatial and temporal discretization is analyzed in terms of the dissipated energy during the fracture process. The dissipation at the onset of branching is studied for different loading rate conditions and is linked to the experimental maximum velocity observed before branching takes place.

Microstructural development and mechanical properties of a near-eutectic directionally solidified Sn–Bi solder alloy

Sn–Bi solders may be applied for electronic applications where low-temperature soldering is required, i.e., sensitive components, step soldering and soldering LEDs. In spite of their potential to cover such applications, the mechanical response of soldered joints of Sn–Bi alloys in some cases does not meet the strength requirements due to inappropriate resulting microstructures. Hence, careful examination and control of as-soldered microstructures become necessary with a view to pre-programming reliable final properties. The present study aims to investigate the effects of solidification thermal parameters (growth rate — VL and cooling rate — ṪL) on the microstructure of the Sn–52wt.%Bi solder solidified under unsteady-state conditions. Samples were obtained by upward directional solidification (DS), followed by characterization through metallography and scanning electron microscopy (SEM). The microstructures are shown to be formed by Sn-rich dendrites decorated with Bi precipitates surrounded by a complex regular eutectic mixture, with alternated Bi-rich and Sn-rich phases. Experimental correlations of primary (λ1), secondary (λ2), tertiary (λ3) dendritic and eutectic spacings (λcoarse and λfine) with cooling rate and growth rate are established. Two ranges of lamellar eutectic sizes were determined, described by two experimental equations λ=1.1 VL−1/2 and λ=0.67 VL−1/2. The onset of tertiary branches within the dendritic array along the Sn–52wt.%Bi alloy DS casting is shown to occur for cooling rates lower than 1.5°C/s.