Cell-instructive biointerfaces with dynamic complexity

The extracellular environment is a highly dynamic milieu where instructive cues (i.e., signals) that originate from the surrounding matrix and neighboring cells are tightly controlled in a spatiotemporally regulated manner. Incorporation of bioinspired dynamic cues, while designing new cell-instructive biointerfaces, has recently been an important focus in biomaterials development for regenerative medicine applications. In this line, progressive developments in materials chemistry as well as introduction of non-covalent chemistries and stimuli-responsive elements in biomaterials design has opened up tremendous opportunities to achieve such highly biomimetic cell-instructive biointerfaces with dynamic regulation of physical, chemical and mechanical cues, to guide desired cell and tissue response. In this thesis, chemical approaches to fabricate dynamic cell-instructive biointerfaces using light-responsive liquid crystal polymer networks (LCNs) and supported lipid bilayers (SLBs) are presented and discussed with an emphasis put on investigating (stem) cell behavior. In the first part of the thesis, temporal control over cell migration upon light-induced in situ changes in nanotopographical cues is achieved on azobenzene conjugated LCNs. This work introduces these materials as new biointerfaces. In the second part of the thesis, central focus is on how to exploit SLBs as dynamic cell-instructive platforms providing control over ligand density, mobility, functionalization route, composition (i.e., type of the peptide ligand) as well as peptide-SLB interactions. On SLBs, functionalized via biotin-neutravidin interactions, ligand (i.e., integrin targeting RGD) density and mobility are shown as important parameters to guide hMSC behavior. Next, using lipid insertion (i.e., using alkyl tail or cholesterol modified (lipidated) RGD ligands) as functionalization route, both lateral (in-plane) and out-of-plane dynamicity of the ligands are controlled. The length of the alkyl tail (i.e., interaction strength of lipidated peptide and SLB) that is conjugated to RGD peptide is shown to be critical to control hMSC adhesion, spreading and focal adhesion formation in these cells on laterally mobile ligands (i.e., in fluid SLBs). Using a dye-conjugated lipid-modified RGD, the dynamic presentation of the peptide is further demonstrated together with the propensity of hMSCs to take up the peptide as well as the dependency of cell migration on the lipid anchor type conjugated on RGD. In the final part, the complexity of the surfaces is tuned by controlling lipid-modified peptide compositions for mimicking cell-matrix and cell-cell junctions in fluid SLBs, to guide endothelial cell behavior. In the epilogue, first steps are explored and discussed that are taken to employ SLBs as cell-instructive interfaces on biomaterials

"Trade Unions at Whose Service?" Coercive Partnerships and Partnership in Coercion in Turkey’s metal sector

"Partnership in coercion is defined as cooperation between trade unions and employers at the expense of workers’ interests. It differs from coercive partnership by trade unions’ not mandatory but willing participation for furtherance of their own interests that are detached from those of their members. The legal changes after 1980 in Turkey created the basic conditions for both of these partnerships patterns. The analysis of the metal industry bargaining system reveals that there are three additional factors which rendered partnership in coercion possible in this sector: employers’ needs, weak trade union internal democracy and competition among trade unions. However the examination of some other industries in Turkey shows that partnership patterns in the metal sector cannot be easily used to make generalizations. Yet it possible to consider them as extreme forms which reveal a fundamental feature of partnership clearly: the nature and outcome of partnership are determined by complex interdependencies which are beyond the immediate control of those who are actually becoming partners." (author's abstract)"Partnerschaftliche Kollaboration als Zusammenarbeit zwischen Arbeitgebern und Gewerkschaften zu ihrem beiderseitigen Nutzen und auf Kosten von Arbeitnehmerinteressen ist zu unterscheiden von der erzwungenen Partnerschaft, die Gewerkschaften mit Arbeitgebern aus Überlebensgründen, ohne direkte Vorteile für sich und losgelöst von den Interessen ihrer Mitglieder, eingehen. Die türkischen Gesetzesänderungen nach 1980 haben die Basis für beide Partnerschafts-Modi geschaffen. Eine Analyse des Verhandlungssystems in der Metallindustrie ermittelt drei weitere Faktoren, die die partnerschaftliche Kollaboration in diesem Sektor möglich gemacht haben: die Bedürfnisse der Arbeitgeber, der fragwürdige Zustand der innergewerkschaftlichen Demokratie und der Wettbewerb zwischen den Gewerkschaften. Der Vergleich mit anderen Sektoren ergibt, dass die Partnerschaftsmuster in der Metallindustrie sich nicht ohne weiteres verallgemeinern lassen. Art und Ergebnis von Partnerschaften werden vielmehr durch komplexe Abhängigkeiten bestimmt, die jenseits der Kontrolle derer liegen, die die Partnerschaft eingehen." (Autorenreferat

Eight Karats of Justice: Analysis of the Grassroots Resistance Movement Against Goldmining in the Villages of Bergama, Turkey

This study explores and analyzes the grassroots movement against goldmining in the villages of Bergama, Turkey. The struggle of Bergama villagers started out as a local ecological resistance movement in the early 1990s and gradually transformed into an environmental justice movement with national implications when activists adopted a rights-based discourse by incorporating into their claims the notions of justice, democratic participation, and citizenship rights. Since goldmining investment in Bergama was a manifestation of significant shifts in the global corporate mining industry starting in the 1980s, and of changes in the world political economy, an account of these shifts is presented as the global political-economic background for the grassroots resistance movement in Bergama. This global perspective is complemented by an account of the domestic socio-economic and political context in which the Bergama villagers’ resistance movement unfolded. The study employs two reference frames for the conceptual and theoretical analysis of the Bergama villagers’ movement. The Environmental Justice Movement (EJM) Literature is reviewed for conceptual clues pertaining to the transformation process of the movement under investigation. As the theoretical reference frame, the New Social Movements (NSM) approach to contemporary social movements is employed in an attempt to assess the applicability of this theoretical approach to the resistance movement of Bergama villagers, as well as the EJM in the United States. NSM theories are inadequate in explaining these movements. Based on the weaknesses of the NSM and the similarities identified between the Bergama villagers’ movement and the EJM, I assert that a new approach to theorizing social movements, which takes as its point of departure these similarities, is necessary. I argue that such an approach will guide not only social movement scholars in understanding ecological grassroots movements in the global North and South but also movement activists in their struggle for social change. In contrast, an exclusive focus on the distinctions between the ecological grassroots movements in the global South, on the one hand, and in the North, on the other, based merely on their economic and cultural differences, will be counter-productive in challenging the systemic root causes of ecological problems plaguing the people of the world today

Anatomska obilježja i kvaliteta vlakana stabljike vinove loze (Vitis vinifera L.)

This study investigated the anatomical characteristics and fibre quality for papermaking indices of Vitis vinifera L. (grapevine) stem wood, which is extracted as agricultural waste. Two grapevine trunks were collected from the Gülnar region in Turkey. Observations on microscopic anatomical characteristics were carried out on sectioned and macerated wood samples. According to the measurements conducted, the following mean anatomical characteristics were determined: earlywood vessel tangential diameter 258.81 μm, latewood vessel tangential diameter 35.52 μm, ray width 197.19 μm, ray height 4618.67 μm, vessel length 498.85 μm, fibre length 1.03 mm, fibre diameter 22.05 μm, and fibre wall thickness 4.23 μm. Based on the determined characteristics linked to the fibre quality, the fibres of the grapevine can be placed in Quality Class III for pulp and paper processing. All derived indices of grapevine met the acceptable threshold except for the flexibility ratio. Examining the anatomical structure of the grapevine will enable a database to be created for further studying of wood anatomy and these characteristics can be evaluated with respect to other possible areas of use.U ovom su radu istražena anatomska obilježja i indeksi kvalitete vlakana za proizvodnju papira od stabljika vinove loze (Vitis vinifera L.) koje se ekstrahiraju kao poljoprivredni otpad. Dva uzorka stabljike vinove loze prikupljena su iz regije Gülnar u Turskoj. Promatranja mikroskopskih anatomskih obilježja provedena su na presječenim i maceriranim uzorcima vinove loze. Prema provedenim mjerenjima, utvrđene su ove srednje anatomske vrijednosti: tangentni promjer traheje ranog drva 258,81 μm, tangentni promjer traheje kasnog drva 35,52 μm, širina drvnog traka 197,19 μm, visina drvnog traka 4618,67 μm, duljina traheje 498,85 μm, duljina vlakana 1,03 mm, promjer vlakana 22,05 μm i debljina stijenke vlakana 4,23 μm. Na temelju utvrđenih obilježja vezanih za kvalitetu vlakana, vlakna vinove loze mogu se svrstati u III. razred kakvoće materijala za preradu celuloze i papira. Svi proizvodni indeksi vinove loze, osim omjera fleksibilnosti, zadovoljili su prihvatljivi prag. Ispitivanje anatomske strukture vinove loze omogućit će stvaranje baze podataka za daljnje proučavanje anatomije vinove loze i na taj će se način navedena obilježja moći proučavati u drugim područjima uporabe

Automatic Knot Adjustment Using Dolphin Echolocation Algorithm for B-Spline Curve Approximation

In this paper, a new approach to solve the cubic B-spline curve fitting problem is presented based on a meta-heuristic algorithm called " dolphin echolocation ". The method minimizes the proximity error value of the selected nodes that measured using the least squares method and the Euclidean distance method of the new curve generated by the reverse engineering. The results of the proposed method are compared with the genetic algorithm. As a result, this new method seems to be successful.Comment: The Journal of MacroTrends in Technology and Innovation, Vol 4. Issue 1. 201

Un enfoque computacional para el análisis de composiciones artísticas

Los nuevos enfoques que surgen del análisis de obras de arte con herramientas computacionales tienen el potencial de ofrecer diferentes perspectivas a las obras de arte recreadas en medios digitales. Este artículo pretende revelar las relaciones implícitas entre las composiciones de Mondrian con diferentes representaciones visuales. En el ámbito del estudio, las composiciones completadas entre 1938 y 1943, que tienen una fuerte relación geometría-color, se investigaron primero a través de un enfoque basado en píxeles. En el método de fragmentación empleado a seguir, las similitudes y diferencias se expresan con datos transferidos de píxeles a matrices numéricas en dos pasos diferentes: 1) Entre los artefactos en pares, y 2) Entre un artefacto y todos los demás artefactos seleccionados. La visualización de las matrices estuvo representada por mapas de color 2D y mapas de textura 3D. Estos estilos de interpretación permiten que las composiciones se expresen de lo general a lo específico y nuevamente de lo específico a lo general, adquiriendo un nuevo significado.Novas abordagens emergem da análise de obras com ferramentas computacionais e têm potencial para oferecer diferentes perspectivas para obras recriadas em ambientes digitais. Este estudo visa revelar as relações implícitas entre as composições de Mondrian com diferentes representações visuais. No âmbito do estudo, as composições concluídas entre 1938 e 1943, que possuem uma forte relação geometria-cor, foram discutidas pela primeira vez com uma abordagem baseada em pixels. No método de fragmentação seguido, as semelhanças e diferenças são expressas com dados transferidos de pixels para matrizes numéricas em duas etapas distintas: 1. Entre os artefatos em pares, 2. Entre um artefato e todos os outros artefatos selecionados. A visualização das matrizes foi representada por mapas de cores 2D e mapas de texturas 3D. Esses estilos de interpretação permitem que as composições sejam expressas do geral para o específico e novamente do específico para o geral, ganhando um novo significado.New approaches emerging from the analysis of artworks with computational tools have the potential to offer different perspectives to artworks recreated in digital environments. This study aims to reveal the implicit relationships between Mondrian compositions with different visual representations. In the scope of the study, compositions completed between 1938 and 1943, which have a strong geometry-color relationship, were first investigated through a pixel-based approach. In the fragmentation method followed, the similarities and differences are expressed with data transferred from pixels to numerical matrices in two different steps: 1. Between the artifacts in pairs, 2. Between an artifact and all the other selected artifacts. The visualization of the matrices was represented by 2D color maps and 3D texture maps. These interpretation styles allow the compositions to be expressed from general to specific and again, from specific to general, by gaining a new meaning

ESTIMATION OF UNBALANCE COST DUE TO DEMAND PREDICTION ERRORS USING ARTIFICIAL NEURAL NETWORK

Estimation of energy demand is used as an important tool for decision makers determining company strategies and policies. Apart from this, the fact that the actual consumption differs from the forecast is harmful for the economy of the company and even for the economy of the big scale. In this study, it is aimed to estimate the imbalance aberration caused by demand forecast deviation with Artificial Neural Networks and to evaluate its results

Painful chestwall swellings: tietze syndrome or chest wall tumor?

Objective Tietze syndrome (TS) is an inflammatory condition characterized by chestpain and swelling of costochondral junction. Primary chest wall tumors maymimic TS. Inthis article, we report our experience of approximately 121 patients initially diagnosedas TS and determined chest wall tumor in some cases at the follow-up.Methods This is a retrospective review of patients diagnosed as TS by clinicalexamination, chest X-ray, electrocardiogram, routine laboratory tests, and computedtomography (CT) of chest: all treated and followed up between March 2001 andJuly 2012. There were 121 cases (41males and 80 females;mean age, 39.6 3.2 years)of TS.Results In 27 patients with initial normal radiological findings, the size of swellings haddoubled during the follow-up period (mean, 8.51 2.15 months). These patients werereevaluated with chest CT and bone scintigraphy and then early diagnostic biopsy wasperformed. Pathologic examination revealed primary chest wall tumor in 13 patients(5 malignant, 8 benign). CT had a sensitivity of 92.3% and a specificity of 64.2% indetection of tumors (kappa: 0.56, p ¼ 0.002), whereas the sensitivity and the specificityof bone scan were 84.6 and 35.7%, respectively (kappa: 0.199, p ¼ 0.385).Conclusion Primary chest wall tumors could mimic TS. Bone scintigraphy or CT is notspecific enough to determine malignant and other benign disorders of costochondraljunction. Therefore, clinicians should follow TS patients more closely, and in case ofincreasing size of swelling, early diagnostic biopsy should be considered

Bir İnsan ve Toplum Problemi Olarak Yanlış Bilgi

Disinformation/mesenformation, or misinformation as it is commonly used in Turkish, is a global issue. Therefore, resilience and resistance to misinformation must be organized globally. However, the problem will continue to grow as the issue is handled independently from the local, unless preventive actions are produced by covering local semantics. Covering the local here is possible by centered on media users as social actors and understanding the role of misinformation both online and offline in their daily lives. Here, the concept of trust stands as an important determinant that needs to be addressed.Dezenformasyon/mezenformasyon, ya da Türkçe kullanımdaki yaygın karşılığıyla yanlış bilgi, küresel bir mesele. Dolayısıyla, yanlış bilgiye karşı dayanıklılık ve direnç küresel olarak örgütlenmeli. Ancak konu yerelden bağımsız ele alındıkça ve önleyici faaliyetler yerel semantiği kapsayarak üretilmedikçe sorun büyüyerek devam edecek. Burada yereli kapsamak, medya kullanıcılarını toplumsal aktörler olarak merkeze alıp yanlış bilginin onların gündelik yaşantılarındaki hem çevrimiçi hem çevrimdışı rolünü anlamakla mümkün olur. Burada güven kavramı ele alınması gereken önemli bir belirleyen olarak karşımızda duruyor