No description available.

No description available.

<p>The Slit morphogen is a secreted glycoprotein that is naturally cleaved into two fragments. The amino fragment (N-Slit) contains Leucine Rich Repeats (LRR) that are recognised by Robo receptors, and is sufficient to mediate attractive or repellent signalling in <em>Drosophila </em>tissues, for example, during growth cone guidance at the midline of the nervous system. The carboxy fragment (C-Slit) is composed of EGF repeats and a Laminin-like globular domain. Although C-Slit expression does not restore repellent signalling, it does rescue other morphogenetic defects in <em>slit</em> mutants.</p> <p>Formation of the dorsal vessel (or heart) requires function of <em>slit</em> and <em>robo</em>. Slit is required for coordinated migration of heart cell precursors, cell polarisation and the formation of a lumen in the heart tube. We have characterised the morphogenetic activities of N- Slit and C-Slit during assembly of the heart.</p> <p>Our laboratory has shown that Slit transgenes lacking the LRR region fail to rescue the mutant phenotype in the nervous system. However, <em>slit</em> trangenes lacking the LRR results in a partial rescue phenotype in the heart suggesting that C-Slit might have functional significance in the heart. Therefore, Slit function in heart vasculogenesis has different requirements compared to the nervous system. For example, Slit –Robo2 interaction may have an adhesive function in addition to a signalling function during vasculogenesis.</p> <p>Our results indicate that C-Slit funtions as a heart morphogen. In <em>slit</em> mutants, over-expression of C-Slit results in a partial rescue phenotype with several features such as cell clumping, overlapping of cells and cells which are elongated. Together, these data suggest alternative functions for Slit during heart morphogenesis.</p> / Master of Science (MSc)

Submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic, Durban University of Technology, Durban, South Africa, 2015. / Background: When a soft tissue injury occurs the blood vessels and surrounding tissue are damaged leading to haemorrhaging and inflammation. Cryotherapy (cold therapy) is generally acknowledged as the preferable treatment by manual therapists during this immediate post-traumatic period of an injury. Cryotherapy has been shown to result in vasoconstriction decreasing the rate of blood flow which has a favourable effect on inflammation and pain. The commercially available cooling cuff is a relatively new cryotherapy modality offering a mechanism of cooling that does not require freezing and is easy to use. The polymer granules within the cooling cuff are activated by emersion in water therefore freezing is not required making the cooling cuff readily available compared to more traditional forms of cryotherapy. Aim: The aim of this study was to determine the effect of a moist ice pack and a commercially available cooling cuff radial artery blood flow (cm.s-1) and radial artery lumen diameter (mm) after 15 minutes of application. Method: This study was a pre-test post-test design utilising 43 asymptomatic participants that were randomly allocated to one of two groups. Each group either received a standard moist ice pack or a commercially available cooling cuff, placed on the ventral surface of the participants forearm, over the radial artery, for a duration of 15 minutes. Measurements were taken with a Doppler ultrasound to determine radial artery blood flow and lumen diameter, prior to the intervention and 15 minutes after the cryotherapy application. Data analysis was performed using IBM SPSS VERSION 20 (IBM Corp. Released 2010.IBM SPSS Statistics for Windows, Version 19.0. Armonk, New York: IBM Corp.). Statistical significance was set at a p< 0.05 level. Intra-group and inter-group comparisons were measured using repeated measures ANOVA testing. Results: Both the moist ice pack and commercially available cooling cuff resulted in a significant decrease in radial artery blood flow (p< 0.001) after 15 minutes of application with no significant changes being observed in radial artery diameter Conclusions: The commercially available cooling cuff resulted in a similar effect on radial artery blood flow and lumen diameter as moist ice, indicating that the commercially available cooling cuff may be utilised in the acute phase of an injury to alter blood flow. / M

This paper analyzes the anatomical response of Pinus pinaster Ait. following wounding by flash floods. A total of 14 wood samples were taken from 14 different scarred trees located on the river banks of the Arroyo Cabrera torrent (Spanish Central System). In addition, 20 increment cores were collected from undisturbed and healthy P. pinaster trees to build a local reference chronology. For the injured trees, analysis focused on growth changes in early earlywood (EE) tracheids, namely on differences in (i) lumen size; (ii) cell-wall percentage and cell-wall thickness; (iii) radial length and tangential width of tracheids; as well as (iv) in the abundance of resin ducts in earlywood (EW) and latewood (LW) following wounding. Results indicate that tissues bordering flash-flood wounds are characterized by reduced growth rates and a decrease of EE tracheid lumen area by 51%. In addition, cell-wall percentage increases by 34% in the increment rings formed after the event and significant changes are observed in the radial length and tangential width of EE tracheids. Observations on resin ducts do not yield any significant results. Based on these anatomical parameters, detecting and dating past flash-flood events in growth rings is now possible for Mediterranean species, specifically P. pinaster.

The Sun is the ultimate energy source on Earth. Photosynthetic organisms are able to catalyze the conversion of solar energy to chemical energy by a reaction called photosynthesis. In plants, this process occurs inside a green organelle called the chloroplast. The protein complexes involved in the photosynthetic light reactions are situated in the thylakoid membrane, which encloses a tiny space called lumen. The Peptidyl-Prolyl cis-trans Isomerase (PPIase) family is the most abundant protein family in the thylakoid lumen. The three PPIase subfamilies, cyclophilins, FKBPs (FK506 binding proteins) and parvulins form a group by their enzymatic activity despite lack of sequence similarity between the subfamilies. Cyclophilins and FKBPs, collectively called immunophilins, were originally discovered as the targets of the immunosuppressive drugs cyclosporine A and FK506, respectively. By suppressing the immune response in humans, these immunophilin-drug complexes revolutionized the field of organ transplantation by preventing graft rejection. Cis-trans isomerization of peptide bonds preceding the amino acid proline is the rate-limiting step of protein folding and several immunophilins have been shown to be important for catalysis of protein folding in vivo. PPIases have been found to be part of large protein complexes as well as in functions such as signalling, protein secretion, RNA processing and cell cycle control. A picture is therefore emerging in which the actual interaction between the PPIase and its target is perhaps more important than the PPIase activity. In the present work, PPIases have been characterized in the chloroplast thylakoid lumen of Spinacia oleracea (spinach) and Arabidopsis thaliana (Arabidopsis). The most active PPIase in the spinach lumen was identified as the cyclophilin TLP20. AtCYP20-2, the Arabidopsis homologue of TLP20, was found to be upregulated at high light and attached to the thylakoid membrane, more precisely to the outer regions of photosystem II supercomplexes. In Arabidopsis, up to 5 cyclophilins and 11 FKBPs were predicted to reside in the lumen. Of these 16 immunophilins, only 2 were identified as active PPIases and significant differences were observed between the two plant species. AtCYP20-2, like TLP20, is an active isomerase although AtFKBP13 is the most active PPIase in the lumen of Arabidopsis. Mutant Arabidopsis plants deficient in AtCYP20-2 displayed no phenothypical changes or decrease in total lumenal PPIase activity. Being the only active PPIase in the mutants, the redox sensitive AtFKBP13 is proposed to compensate for the lack of AtCYP20-2 by oxidative activation. In agreement with the experimental data, the sequence analyses of catalytic domains of lumenal immunophilins demonstrate that only AtCYP20-2 and AtFKBP13 possess the amino acids found essential for PPIase activity in earlier studies of human cyclophilin A and FKBP12. It is concluded that with the exception of AtCYP20-2 and AtFKBP13 most immunophilins in the lumen of Arabidopsis lost their PPIase activity on peptide substrates and developed other specialized functions.

Abstract Integrins are a large family of &#945;&#946;-heterodimeric cell adhesion receptors of which the cell type specific expression defines the extracellular matrix (ECM) binding properties of different adherent cell types. In addition to various growth factors and their receptors, epithelial morphogenesis is also executed by dynamic changes in the chemical composition and physical properties of the ECM that controls the shape and behavior of the associated cells via integrin mediated adhesion and signalling. Epithelial cell polarity and contractility are central mechanisms of epithelial shape determination and are established upon spatially, mechanically and chemically sensitive integrin signals of the microenvironment. The functional hierarchy between different integrin heterodimers and their ECM ligands in organizing these tasks has not been systematically addressed. In order to study the relative roles of different integrins, we set up a loss-of-function screen of co-expressed integrin subunits in the Madin-Darby canine kidney (MDCK) epithelial cell line. By analyzing MDCK cystogenesis in three-dimensional (3D) ECMs, we were able to establish a model of how epithelial polarity is organized: cell adhesion either by &#945;2&#946;1- or &#945;6&#946;4-integrins defines the orientation of cell polarity and coordinated functions of &#945;2&#946;1- and &#945;3&#946;1-integrins mediate the establishment of epithelial lumens via cavitation and hollowing, respectively. By analyzing the spreading of MDCK cells, we established that epithelial cell contractility is based on synergistic functions of &#946;1-integrins that mediate cell adhesion and &#945;V-integrins that facilitate ECM rigidity sensing. We also discovered that the hemidesmosomal integrin &#945;6 and integrin &#946;4 did not require heterodimerization to be transported to the plasma membrane (PM) and that integrin &#946;4 may support laminin assembly to the basement membrane (BM) independently of integrin &#945;6. / Tiivistelmä Integriinit ovat suuri molekyyliperhe &#945;&#946;-heterodimeerisiä adheesioreseptoreja. Integriinit ilmentyvät eri tavoin eri solutyypeissä, ja tämä säätelee sitä, miten solut tarttuvat ja reagoivat erilaisiin soluväliaineisiin. Tällä tavalla integriinit ja soluväliaine osallistuvat myös epiteelimorfogeneesiin lukuisten kasvutekijöiden ja niiden reseptoreiden lisäksi. Epiteelimorfogeneesissä etenkin solujen polarisaatio ja solujen supistuminen ovat tärkeitä tapahtumia, joiden ohjaukseen integriinit ja soluväliaine osallistuvat. Tämän tutkimuksen tarkoituksena oli selvittää eri integriinien ja niiden soluväliaineligandien toiminnallista hierarkiaa epiteelimorfogeneesissä, etenkin solujen polarisaatiossa ja supistumisessa. Integriinien keskinäisten roolien selvittämiseksi hiljensimme ilmentyvät integriinialayksiköt yksitellen munuaisen epiteelisolulinjasta RNA-häirinnän avulla. Mallina epiteelimorfogeneesille käytimme hyväksi munuaisepiteelisolujen kykyä muodostaa rakkularakenteita kolmiulotteisessa soluväliaineessa viljeltyinä. Näitä rakenteita analysoimalla pystyimme muodostamaan mallin siitä, miten polarisoitunut epiteelirakenne organisoituu: &#945;2&#946;1- tai &#945;6&#946;4-integriinien välittämä adheesio tarvitaan solujen polariteetin orientoimiseen ja &#945;2&#946;1- ja &#945;3&#946;1-integriinien yhteistoiminta tarvitaan epiteelisen rakkulan tyhjän sisäosan muodostumiseen, joko apoptoosin tai polarisoituneen kalvokuljetuksen kautta. Tutkimalla solujen levittäytymistä jäykälle kaksiulotteiselle alustalle pystyimme määrittämään, että epiteelisolun supistuminen pohjautuu &#946;1-integriinien välittämän adheesion ja &#945;V-integriinien välittämän väliaineen jäykkyyttä aistivien signaalien yhteistoimintaan. Havaitsimme myös, että hemidesmosomaalisten integriinien &#945;6 ja &#946;4 sekretioon ei tarvittu näiden keskinäistä heterodimerisaatiota ja integriini &#946;4:llä saattaa olla integriini &#945;6:sta riippumaton rooli laminiinin kokoamisessa tyvikalvoon.

This master thesis deals with the integration of new devices from the manufacturers Revogi, Tabu Lumen, Sonoff and HomeMatic into the BeeeOn Gateway software. The theoretical part deals with the architecture of the BeeeOn Gateway software and describes the characteristics, behavior and way of communication with devices from the above mentioned manufacturers. This part of thesis also contains a description of the communication technologies used by these devices. They include Bluetooth Low Energy, the WiFi and the 868 MHz radio. The practical part mentions the way of extension of BeeeOn Gateway software to modules that implement support for smart devices. This section also describes how the correctness of implementation was verified and testing of the entire BeeeOn Gateway software. The testing of gateway is performed by unit and integration tests, which verify the behavior of individual gateway components as well as the whole gateway.

The aim of this thesis was to investigate morphogenesis in the fruit fly Drosophila melanogaster using three in vitro tissue culture systems. Primary embryonic cultures derived from Drosophila melanogaster were used to study the effect of the moulting hormone ecdysone on cells in culture. The hypothesis was that the effect of ecdysone on these primary embryonic cells would parallel events which occur during metamorphosis in vivo and therefore the primary embryonic cultures could be used as an ‘in vitro’ model system. Transgenic fly lines expressing GFP were used to visualise and identify specific cell types and it was shown that cells in primary embryonic cultures respond to ecdysone morphologically. However due to the variability of cultures it was concluded that this culture system was not suitable for use as a model system. As defined cell types were observed the development of a protocol suitable for use with the primary embryonic culture system using dsRNA in order to demonstrate RNA interference was undertaken. Although this was unsuccessful, as cells in the primary embryonic cultures appeared to be resistant to dsRNA, some technical avenues remain to be explored. The Drosophila melanogaster cell line, Clone 8+, was used to investigate cell adhesion in tissue culture. Statistical analyses were carried out and it was established that derivatives of the parent cell line, Clone 8+, showed differential adhesion and proliferation characteristics. Analysis of microarray data was carried out in order to identify genes which may be responsible for the loss of cell adhesion in Clone 8+ cell lines and the potential roles of these genes in adhesion were discussed. A gene of interest, glutactin, was identified which may be responsible for loss of cell adhesion. Antibody staining was used to establish the expression of the protein glutactin in the Clone 8+ cell lines. The expression of glutactin suggested that the Clone 8+ cell line had maintained properties of the wing disc epithelial cell-type and disruption of cell polarity was considered as a possible mechanism. It was shown that f-actin colocalised with glutactin and the role of the cytoskeleton in glutactin secretion was discussed. It was concluded that glutactin was not responsible for loss of cell adhesion in the Clone 8+ cell lines. Further analysis of the microarray data revealed potential genes that could be responsible for the loss of cell polarity in the Clone 8+ cell lines and the possibility of cellular senescence was considered. It was hypothesised that the properties of adhesion and proliferation related to their ‘in vitro’ age. In the final investigation the movement of epithelial cells in Drosophila melanogaster third instar larval imaginal discs during morphogenesis was investigated. Firstly a lumen was identified in fixed imaginal disc tissue in association with cells expressing f-actin. This result was discussed in relation to the process of dorsal closure and wound healing. Further investigations involved live imaging of the dynamic process of evagination in the imaginal wing disc using transgenic flies expressing moesin-GFP. It was concluded that the lumen was not associated with the process of wound healing and it was concluded that the lumen appeared to be the mechanism directing peripodial epithelium contraction during morphogenesis of the imaginal wing disc. Dorsal closure and the process of invagination in relation to morphogenesis of the imaginal wing disc were discussed.

Das Dorsalgefäß von Drosophila ist ein wertvolles Modellsystem für die Untersuchung der genetischen und molekularen Mechanismen der Kardiogenese. Ein Schlüsselereignis der Kardiogenese ist die Bildung eines Herzlumens, durch das die Hämolymphe gepumpt wird, um Nährstoffe und Zellen des angeborenen Immunsystems zu zirkulieren. Ein Schwerpunkt meiner Arbeit umfasste die Identifizierung neuer Gene, die im embryonalen Dorsalgefäß von Drosophila exprimiert sind. Dafür habe ich die Expression von 101 Genen, deren Orthologe spezifisch im Herzen von Zebrafisch exprimiert sind, in Drosophila untersucht. Ich identifizierte ein Gen, das für das Cbl-assoziierte Protein (CAP) kodiert. Durch Herstellung eines anti-CAP Antikörpers konnte ich erstmals eine detaillierte Lokalisation des CAP-Proteins im Dorsalgefäß beschreiben. Interessanterweise stellte sich dabei heraus, dass CAP ähnlich wie die homologen Vertebraten Proteine embryonal an den fokalen Adhäsionskontakten der Kardioblasten und im adulten Dorsalgefäß auch an den Z-Scheiben und den Zell-Zell-Kontaktstellen der Kardiomyozyten lokalisiert ist. Des Weiteren untersuchte ich, welche Auswirkungen der Verlust der CAP Funktion auf die Herzentwicklung hat. Für die Analyse der CAP-Mutanten nutzte ich neben Immunhistochemischen Methoden auch ultrastrukturelle Analysen mittels TEM-Mikroskopie. So konnte ich zeigen, dass embryonale Dorsalgefäße von CAP-Mutanten eine fehlerhafte Anzahl sowie Anordnung der Kardioblasten und Lumendefekte aufweisen. Ein genetischer Interaktionstest untermauerte meine Vermutung, dass CAP mit dem Integrinsignalweg während der embryonalen Dorsalgefäßentwicklung interagiert. Live-Aufnahmen des pumpenden Dorsalgefäßes von Drosophila L3-Larven und Injektionstests an späten Puppen zeigten zudem, dass der Verlust der CAP Funktion auch zu starken Defekten in der Funktionalität des larvalen und adulten Dorsalgefäßes führt. / The heart of Drosophila provides a valuable model system for the examination of the genetic and molecular mechanisms that guide cardiogenesis. A key event of cardiogenesis is the formation of a heart lumen through which the hemolymph is pumped to circulate nutrients and cells of the innate immune system. A main focus of my work was the identification of new genes that are expressed in the embryonic heart of Drosophila. Therefore I studied the expression of 101 genes, whose orthologues are expressed specifically in the heart of zebrafish. I identified a gene that encodes for the Cbl-associated protein (CAP). By generating an anti-CAP antibody I could describe the localization of the CAP protein in the heart for the first time in detail. Interestingly, it turned out that CAP is located similar to the homologous vertebrate proteins at the focal adhesion contacts of cardioblasts in the embryo and at the Z-discs and the cell-cell contact sites of cardiomyocytes in the adult heart. I also examined the consequences of the loss of CAP function on heart development. For the analysis of the CAP mutants I used immunohistochemical and ultrastructural analysis by TEM microscopy. So I was able to demonstrate that embryonic hearts of CAP mutants show a defective number and arrangement of cardioblasts and lumen defects. A genetic interaction test substantiated my guess that CAP interacts with the Integrin signaling pathway during embryonic heart development. Live recordings of the pumping heart of Drosophila L3 larvae and injection tests of late pupae also showed that the loss of CAP function leads to severe defects in the functionality of the larval and adult heart.