Mechanics of invagination and folding: Hybridized instabilities when one soft tissue grows on another.

We address the folding induced by differential growth in soft layered solids via an elementary model that consists of a soft growing neo-Hookean elastic layer adhered to a deep elastic substrate. As the layer-to-substrate modulus ratio is varied from above unity toward zero, we find a first transition from supercritical smooth folding followed by cusping of the valleys to direct subcritical cusped folding, then another to supercritical cusped folding. Beyond threshold, the high-amplitude fold spacing converges to about four layer thicknesses for many modulus ratios. In three dimensions, the instability gives rise to a wide variety of morphologies, including almost degenerate zigzag and triple-junction patterns that can coexist when the layer and substrate are of comparable softness. Our study unifies these results providing understanding for the complex and diverse fold morphologies found in biology, including the zigzag precursors to intestinal villi, and disordered zigzags and triple junctions in mammalian cortex.T. T. acknowledges the Academy of Finland for funding. The computational resources were provided by CSC – IT Center for Science. J.B. acknowledges the 1851 Royal Commission and Trinity Hall Cambridge for funding.This is the author accepted manuscript. The final version is available from APS via http://dx.doi.org/10.1103/PhysRevE.92.02272

Leanin hyödyntäminen valmistavan teollisuuden layout-suunnittelussa

Tämän kandidaatin työn aihe on leanin hyödyntäminen layout-suunnittelussa valmistavan teollisuuden yrityksissä. Teollisuuden yritykset käyttävät vuosittain miljoonia euroja tuotannon tehostamiseen ja yksi iso apuväline siinä on lean-ajattelun hyödyntäminen layout-suunnittelussa. Tuotteiden hintojen jatkuva nostaminen ei ole kestävä työkalu liiketoiminnan kannalta, koska se voi johtaa asiakkaiden menetykseen kilpaileville yrityksille. Vaihtoehdoksi jää valmistuskustannusten alentaminen ilman, että joudutaan tinkimään tuotteiden laadusta tai toimitusajoista. Leanin avulla pyritään karsimaan tuotantoketjusta kaikki mahdolliset arvoa tuottamattomat asiat ja prosessit, eli hukat, pois, jotta valmistuskustannuksia saadaan laskettua laadusta tinkimättä. Layout-suunnittelun avulla pyritään optimoimaan yrityksen tilojen ja laitteiden käyttö, jotta niistä saadaan mahdollisimman tehokkaat. Layout-suunnitteluun kuuluu myös määrittää materiaalien ja työntekijöiden kulkemisreitit mahdollisimman turvallisiksi ja vähäiseksi, jotta aikaa ei kuluisi siirtymiin. Layout-suunnittelua voidaan tehdä kokonaan uuteen tuotantotilaan tai jo käytössä olevaan tilaan. Tämän työn tavoitteena on tutkia miten leania pystytään hyödyntämään layout-suunnittelussa ja selvittää millaisia rajoitteita leanilla voi olla layout-suunnittelun näkökulmasta. Työ tehtiin kirjallisuuskatsauksena. Tapaustutkimusten avulla nähdään, että leanin hyödyntämisellä layout-suunnittelussa voidaan saavuttaa kannattavuuden nousua ja huomattavaa valmistuskustannusten laskua, sekä nopeampia läpimenoaikoja. Leanin hyödyntämisen esteeksi voi tulla kalliit ja aikaa vievät investoinnit, sekä organisaatioiden vastustus muutoksiin ja liian vähäinen motivaatio jatkuvaan parantamiseen. Työn tulokset osoittavat sekä leanin, että layout-suunnitellun olevan varsin tehokkaita tapoja parantamaan tuotannon tehokkuutta jo yksinäänkin, mutta paras ja tehokkain lopputulos saadaan käyttämällä niiden parhaita puolia yhdessä ja yrittämällä minimoida niiden heikkouksia. Leanin työkalujen avulla layouteista saadaan virtaustehokkaita, joissa tuotteiden läpimenoajat pienenevät, joka johtaa tuotteiden nopeampiin toimituksiin asiakkaille. Leanin avulla layoutissa materiaalien siirtymät eri prosessien välillä ovat mahdollisimman pieniä, jolloin suurempi osa ajasta kuluu tuotteelle arvoa tuottavaan aikaan. Virtaustehokkuuden kasvaessa saadaan samassa ajassa tuotetta enemmän tuotteita kuin ennen. Leanin olennainen osa on jatkuva parantaminen ja täydellisyyteen pyrkiminen. Uusien tutkimusten tekeminen on olennaista aina kun syntyy uusia tuotantokonsepteja ja uusia teknologioita, jotta yrityksillä olisi aina käytössään parhaat mahdolliset työkalut tuotannon kehittämiseen

Case study comparing effects of microplastic derived from bottle caps collected in two cities on Triticum aestivum (Wheat)

As plastic has become an integral component of daily life, microplastic has become a ubiquitous, unavoidable constituent of nearly all ecosystems. Besides monitoring the amount and distribution of microplastic in the environment, it is necessary to understand the possible direct effects, especially toxicity and how it is affected by environmental factors where it is discarded. The present study investigated how microplastic derived from high-density polyethylene bottle caps collected in two climatically different cities, i.e., Singapore (tropical rainforest climate) and Lahti, Finland (continental climate), affected the essential agricultural grain crop, Triticum aestivum (L.). Wheat seedlings were exposed to microplastic derived from these collected bottle caps, as well as new and artificially aged caps, for seven days. Morphological parameters, such as root and shoot length and oxidative stress development, were measured. Exposure to microplastic derived from the caps resulted in reduced seedling root and shoot lengths compared to the controls, as well as enhanced lipid peroxidation and catalase activity. With all parameters tested, microplastic derived from Lahti bottle caps exhibited more severe effects than Singapore, which was similar to that elicited by new microplastic. The Singapore microplastic had possibly leached its toxic substances before collection due to accelerated degradation promoted by the prevailing warmer climate conditions

Generation of shape complexity through tissue conflict resolution

Out-of-plane tissue deformations are key morphogenetic events during plant and animal development that generate 3D shapes, such as flowers or limbs. However, the mechanisms by which spatiotemporal patterns of gene expression modify cellular behaviours to generate such deformations remain to be established. We use the Snapdragon flower as a model system to address this problem. Combining cellular analysis with tissue-level modelling, we show that an orthogonal pattern of growth orientations plays a key role in generating out-of-plane deformations. This growth pattern is most likely oriented by a polarity field, highlighted by PIN1 protein localisation, and is modulated by dorsoventral gene activity. The orthogonal growth pattern interacts with other patterns of differential growth to create tissue conflicts that shape the flower. Similar shape changes can be generated by contraction as well as growth, suggesting tissue conflict resolution provides a flexible morphogenetic mechanism for generating shape diversity in plants and animals

Is bigger always better? The importance of cortical configuration with respect to cognitive ability

General cognitive ability (GCA) has substantial explanatory power for behavioral and health outcomes, but its cortical substrate is still not fully established. GCA is highly polygenic and research to date strongly suggests that its cortical substrate is highly polyregional. We show in map-based and region-of-interest-based analyses of adult twins that a complex cortical configuration underlies GCA. Having relatively greater surface area in evolutionary and developmentally high-expanded prefrontal, lateral temporal, and inferior parietal regions is positively correlated with GCA, whereas relatively greater surface area in low-expanded occipital, medial temporal, and motor cortices is negatively correlated with GCA. Essentially the opposite pattern holds for relative cortical thickness. The phenotypic positive-to-negative gradients in our cortical-GCA association maps were largely driven by a similar pattern of genetic associations. The patterns are consistent with regional cortical stretching whereby relatively greater surface area is related to relatively thinner cortex in high-expanded regions. Thus, the typical "bigger is better" view does not adequately capture cortical-GCA associations. Rather, cognitive ability is influenced by complex configurations of cortical development patterns that are strongly influenced by genetic factors. Optimal cognitive ability appears to be driven both by the absolute size and the polyregional configuration of the entire cortex rather than by small, circumscribed regions.Peer reviewe

The heritability of multi-modal connectivity in human brain activity

Patterns of intrinsic human brain activity exhibit a profile of functional connectivity that is associated with behaviour and cognitive performance, and deteriorates with disease. This paper investigates the relative importance of genetic factors and the common environment between twins in determining this functional connectivity profile. Using functional magnetic resonance imaging (fMRI) on 820 subjects from the Human Connectome Project, and magnetoencephalographic (MEG) recordings from a subset, the heritability of connectivity between 39 cortical regions was estimated. On average over all connections, genes account for about 15% of the observed variance in fMRI connectivity (and about 10% in alpha-band and 20% in beta-band oscillatory power synchronisation), which substantially exceeds the contribution from the environment shared between twins. Therefore, insofar as twins share a common upbringing, it appears that genes, rather than the developmental environment, play a dominant role in determining the coupling of neuronal activity