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Whole-air relaxed eddy accumulation for the measurement of isotope and trace-gas fluxes (2012)

Johannes Ruppert Michael Riederer Willi A. Brand Thomas Foken

Measuring the isotopic composition of trace gas fluxes can provide additional information on ecosystem gas exchange, when ecosystem processes, like assimilation, discriminate against heavier isotopes. In the case of CO2 exchange, different mass-balances for bulk CO2 and its 13CO2 or CO18O isotopes can be used to separate respiration from photosynthetic assimilation. Up to now, detectors for direct isotope measurements in the field lack the precision needed for fast eddy covariance (EC) flux measurements. The collection of updraft and downdraft whole-air samples using the relaxed eddy accumulation technique (REA) allows simultaneously determining trace gas concentrations and isotope ratios by high precision laboratory analysis. At the same time whole-air REA relaxes several of the technical problems related to REA sampling on traps. In tests using air from a tank the complete whole-air REA sampling system and its foil balloon bag reservoirs showed no signs of contamination after cleaning. The standard deviations of δ13C and δ18O isotope ratios were only slightly higher than the precision specified for the laboratory analysis procedure. First experiment results showed that isotopic differences (up-drafts−downdrafts) were large enough to yield signal to noise ratios greater than five when applying hyperbolic deadbands during REA sampling (HREA). The performance of the instrument and the HREA sampling method are investigated by simulation of the sampling process for bulk CO2, which serves as proxy scalar. Measurements by whole-air HREA in combination with high precision isotope analysis can quantify the isofluxes of 13CO2 and CO18O. Furthermore, additional information is collected on the scalar correlation of bulk CO2 and its stable isotopes, which represents the relatively short timescale of updrafts and downdrafts in the turbulent exchange above an ecosystem. This information is essential to check the scalar similarity assumptions made in the HREA and EC/flask method for the quan-tification of isofluxes.

Template-Directed Synthesis of One-Dimensional Hybrid Nanostructures from Cylindrical Polymer Brushes (2012)

Markus Müllner

The thesis deals with the study of cylindrical polymer brushes (CPBs) and their use in template chemistry. Herein, we developed template-directed syntheses of one-dimensional (1D) hybrid nanostructures in which CPBs served as 1D soft templates. So called ‘molecular’ core-shell or core-shell-corona CPBs, as well as CPBs obtained through microphase separation of diblock copolymers, were applied as templates for the preparation of various types of 1D organic-inorganic hybrid nanomaterials. Well-defined molecular core-shell and core-shell-corona CPBs with a narrow molecular weight distribution in both the backbone and the side chains have been synthesized via the combination of several polymerization techniques. Anionic polymerization has enabled the precise synthesis of polymer backbones, whereas atom transfer radical polymerization and ring-opening polymerization have allowed the sequential growth of side chains via the ‘grafting-from’ approach. Depending upon the desired functional 1D hybrid nanostructures, different combinations of core, shell and corona have been chosen. Core-shell-corona CPBs with a poly(tert-butyl acrylate) (PtBA) core, a poly(3-acryloylpropyl trimethoxysilane) (PAPTS) shell and a poly[oligo (ethylene glycol) methyl ether methacrylate] (POEGMA) corona were hydrolyzed by aqueous ammonia to produce water-soluble organo-silica hybrid nanotubes. As the trimethoxysilyl group was directly incorporated into the structure of the CPBs, we avoided the addition of an external inorganic precursor. Amphiphilic core-shell-corona CPBs with a hydrophobic poly(ε-caprolactone) (PCL) core, a hydrophilic poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) shell and a hydrophilic POEGMA corona were used as 1D templates and nanoreactors for the fabrication of titania dioxide (TiO2) semiconductor nanotubes. The cationic PDMAEMA shell was loaded with a negatively charged titania precursor, namely titanium(IV) bis(ammonium lactate) dihydroxide (TALH). TALH underwent hydrolysis within the CPB shell upon heating above 70 °C. Accordingly, crystalline (that is, anatase) TiO2 hybrid nanotubes with a very well defined thickness were obtained. Subsequently, the diameter of the hybrid nanotubes was adjusted by modifying the side chain length of the PDMAEMA shell. Amphiphilic core-shell CPBs with a hydrophobic PCL core and a hydrophilic PDMAEMA shell were employed for the fabrication of silica nanotubes with different aspect ratios. Tetramethyl orthosilicate (TMOS) was used for the deposition of silica into the PDMAEMA shell. Several polymers with different dimensions, with respect to length as well as core and shell diameter, were synthesized and used as templates for the fabrication 1D silica nanostructures. Furthermore, silica nanotubes were obtained after acid treatment or calcination, and catalytically active porous nanomaterials were produced via the embedment of metal nanoparticles within the silica shell. All the hybrid nanotubes templated by molecular core-shell and core-shell-corona CPBs were uniform in length as well as diameter, due to the narrow molecular weight distribution of the CPB backbone and side chains. Moreover, the POEGMA corona in the core-shell-corona CPBs served as a shielding layer and protected the nanotubes from agglomeration and intermolecular crosslinking during the hybrid formation. Additionally, POEGMA rendered the hybrid nanomaterials soluble in various solvents, including water. Water-soluble core-shell CPBs were obtained from microphase separated cast films of polystyrene-b-poly(allyl methacrylate) (PS-PAMA) diblock copolymers. After UV-crosslinking of the cylindrical PAMA domains, CPBs with a PS shell and a crosslinked PAMA core were obtained. Subsequent sulfonation rendered the PS shell into poly(styrenesulfonic acid) and thereby made it water-soluble. The negatively charged brush templates were infiltrated with oppositely charged TiO2 nanocrystals to produce crystalline TiO2 hybrid nanowires. Further, it was possible to adjust the crystal structure of the nanostructures to either a rutile or anatase structure. The presented novel 1D hybrid nanomaterials based on CPBs have many potential applications due to their electronic, catalytic and semiconducting properties.

Identification of substrate proteins of FtsH during sporulation of Bacillus subtilis (2012)

Hue Bach Thi Nguyen

FtsH is an ATP- and Zn2+-dependent metalloprotease anchored in the cytoplasmic membrane by two transmembrane segments. It is the unique membrane-bound AAA-protease in bacteria that performs a variety of regulatory functions. In B. subtilis, an ftsH knockout exhibits a pleiotropic phenotype such as filamentous growth, sensitivity towards heat, osmotic shock and cells are unable to sporulate. Recently, it has been shown that ftsH knockout cells fail to entry sporulation stage II due to lack of a sufficient amount of Spo0A~P and the first substrate of FtsH identified in B. subtilis is the Spo0E phosphatase, a negative regulator that dephosphorylates Spo0A~P. However, the sporulation frequency in a spo0E ftsH double mutant strain was only partly restored, we hypothesized that FtsH might degrade additional substrate proteins involved in sporulation. To identify these proteins, two different strategies were applied. By using the 2D gel technique, the proteomes of an ftsH wild-type strain was compared with an ftsH null mutant. Several proteins were identified to be either up- or down-regulated in the absence of FtsH. One of them up-regulated about 4-fold was identified as Spo0M. Since ftsH did not interfere with transcription of spo0M, an in vitro proteolysis assay was established using purified components. It was shown that Spo0M was degraded by FtsH in an ATP- and time-dependent way. In the second strategy, an ftsHtrap mutant was constructed and tested for loss of its proteolytic activity. Protease trap mutants are still able to bind substrate proteins, but are unable to degrade them. By using FtsHtrap fused to a GST-tag, YwnF, a membrane protein, was trapped and identified as a substrate of FtsH by mass spectrometry. However, further experiments will be required to confirm YwnF as a target of FtsH. The last part of this thesis was focused on the eag gene, which forms a bicistronic operon with Spo0E. Construction and analysis of an eag insertion mutant exhibited a slight increase in the sporulation frequency and in the amount of Spo0A. A transcriptional fusion between the promoter of the spo0E-eag operon and the lacZ reporter gene revealed an increase in the beta-galactosidase activity from t0 when the cells were grown in sporulation medium. Since the Eag protein may be an integral membrane protein, it may bind excess Spo0E thereby preventing it from dephosphorylating Spo0A~P. Alternatively, Eag may bind Spo0E and present it as a modulator to FtsH for degradation.

Unique Emulsions based on recombinant Hydrophobins (2012)

Martin Reger

Hydrophobins are very interesting proteins of fungal origin. Beside their relatively small size of around 100 amino acids, they are well known to be the most surface active, natural proteins that have a strong tendency for self-assembly. Due to their versatile properties hydrophobins are present in different fungal structures, like as coaters of hyphae. These diversified properties of hydrophobins raised great interest among scientists. Possible applications in surface modification or emulsion industry were always restricted by the cost and effort of natural hydrophobin purification. This changed dramatically by the use of white biotechnology resulting in the availability of high amounts of recombinant hydrophobins nowadays. This study started with the physicochemical characterization of two recombinant hydrophobins, called H Star Proteins ® A and B. Both show a remarkable, time-dependent surface activity as well as a distinct aggregation behaviour indicating them to have the typical properties of natural hydrophobins. The use of the recombinant hydrophobins as emulsifier resulted in the formation of gel-like oil in water emulsions. Interestingly, without the occurrence of typical emulsion instability processes like creaming or coalescence, these emulsions showed significant aging effects. We conclude them to be the consequence of the time-dependent formation and progression of a self-supporting, three-dimensional protein network that evolves in the emulsion. The self-assemble tendency of recombinant hydrophobins is clearly not limited by adsorption to the oil-water interface. Obviously the long term stability of the emulsion is determined by the sticky character of the hydrophobin coated oil droplets that attract each other in the short range distance. This type of emulsion stabilization mechanism is absolutely novel in the field of emulsion technology. Moreover we used the hydrophobins’ ability of surface modification in order to coat disk-like clay particles. These clay-hydrophobin sandwiches were used for the formation of Pickering Emulsions. It turned out that the synergistic use of clay and hydrophobin resulted in homogenous, long-term stable and tooth-paste like emulsions. The clay particles improved strikingly the rigidity and elasticity of the self-supporting hydrophobin network. Substitution of the clay particles by boehmite needles resulted in similar Pickering emulsions. Finally, we report that it is possible to replace hydrophobin in combination with clay by other proteins, amphiphiles or surfactants. By adjusting the preparation conditions, the emulsifier concentration or the oil mass fraction one has a versatile tool to obtain Pickering emulsions with the desired properties. A new stabilization mechanism in emulsion science is introduced, supported and confirmed by our results.

Novel microemulsions with an anionic/non-ionic surfactant mixture (2012)

Lukas Wolf

Mikroemulsionen bestehen im einfachsten Fall aus Wasser, Öl und Tensid(en). Es handelt sich dabei im Gegensatz zu normalen Emulsionen um transparente, thermodynamisch stabile Phasen. Diesen makroskopisch einphasig erscheinenden Systemen liegen jedoch hoch komplexe Nanostrukturen zu Grunde. Die in wissenschaftlicher Hinsicht bislang am besten untersuchten und verstandenen Mikroemulsionssysteme bestehen entweder aus Wasser, Öl und einem einzigen elektrisch ungeladenen nicht-ionischen Tensid oder einem elektrisch geladenen ionischen Tensid. Beide Systeme unterscheiden sich grundlegend, unter anderem in ihrem Phasenverhalten, ihrer Temperaturstabilität oder ihren Nanostrukturen. Systeme mit Mischungen aus ionischen und nichtionischen Tensiden dagegen wurden bisher kaum untersucht. Im Rahmen dieser Arbeit wurde das Phasenverhalten einer anionischen/nichtionischen Tensidmischung mit verschiedenen Ölen bei konstanter Temperatur und konstantem Tensidgehalt untersucht. Die Phasendiagramme weisen jeweils zwei optisch isotrope Phasengebiete, so genannte Einphasenkanäle, mit steigendem Öl-Gehalt auf. Die beiden Mikroemulsions-Einphasenkanäle sind voneinander durch ein optisch anisotropes Phasengebiet getrennt. Der Mikroemulsionskanal unterhalb des anisotropen Bereichs erstreckt sich von der wässrigen Phase ausgehend mit wachsendem Öl- und nichtionischen Co-Tensid-Anteil bis in die Mitte des Phasendiagramms und endet dort. Der obere Einphasenkanal verläuft durch ein steiles Minimum, in Bezug auf das Tensid/Co-Tensidverhältnis, durchgehend von der wässrigen zur ölreichen Seite des Phasendiagramms. Im Gegensatz zu Mikroemulsionen mit nichtionischen Tensiden handelt es sich um isotherme Einphasenkanäle. Die einphasigen Gebiete wurden mit diversen physikalisch-chemischen Methoden untersucht. Mittels Leitfähigkeits-, SANS-, PFG-NMR-Messungen und elektronenmikroskopischen cryo-TEM Aufnahmen konnten die Nanostrukturen identifiziert werden. Während im unteren Einphasenkanal die Strukturen aus kleinen Öl-Tröpfchen in einer kontinuierlichen Wasserphase bestehen, welche mit zunehmendem Öl-Gehalt anschwellen, kommt es im oberen Einphasenkanal zu einer komplexen Strukturänderung. Während der ölfreien Probe eine bikontinuierliche Schwammstruktur zu Grunde liegt, wandelt sich diese mit bereits wenigen Prozent an Öl zu einer polyedrischen Wasser-in-Öl Schaumstruktur. Für diese, in Mikroemulsionen bislang unbekannten, Struktur wurde der Begriff High Internal Phase Microemulsion (HIPME) eingeführt, aufgrund ihrer strukturellen Parallelen zu bereits bekannten High Internal Phase Emulsionen (HIPE). Mittels transienter Elektrodoppelbrechung konnte dieser komplexe strukturelle Übergang nachvollzogen werden. Die ermittelten strukturellen Relaxationszeiten, welche zudem die Viskosität der Mikroemulsionen bestimmen, weisen ein deutliches Maximum am Übergangspunkt von der bikontinuierlichen zur HIPME-Struktur auf. Grund für die beobachtete HIPME-Struktur ist vermutlich der Anteil der elektrischen Ladung des anionischen Tensids. Diese sorgt für eine vergleichbar hohe Grenzflächenspannung zwischen der wässrigen verdünnten Tensid-Phase und des Öls. Konsequenz dieser hohen Grenzflächenspannung sind ölkontinuierliche Schaumstrukturen anstatt bikontinuierlicher Strukturen, welche man in vergleichbaren Mikroemulsionen mit rein nichtionischen Tensiden erhält. Durch Abschirmen der elektrischen Ladungen mit Salz werden die HIPME-Strukturen gestört, was sich in einem Ansteigen der Leitfähigkeit und einer erhöhten Mobilität der Wasserphase äußert, welche mit NMR beobachtet wurde.

Biochemical and structural characterization of Sirtuins from mammals and Thermotoga maritima (2012)

Mahadevan Lakshminarasimhan

Sirtuins are NAD+ dependent protein deacetylases involved in regulation of metabolism, age related diseases and are suggested to mediate lifespan extending effects of calorie restriction. Mammals contain seven Sirtuin soforms with various cellular localizations and substrate preferences. This work focuses on the structural and biochemical characterization of several mammalian Sirtuin isoforms, with main emphasis on the largest member of the family, Sirt1.Analysis of various Sirt1 constructs using analytical ultracentrifugation and electron microscopy techniques identified it to be a monomer, similar to other mammalian isoforms. Comparison of activity between different Sirt1 constructs indicates that the termini might be involved in regulating the protein’s activity. It could be shown that the catalytic domain of Sirt1 is sufficient for its activation by the lifespan extending polyphenol resveratrol and that resveratrol can directly bind to Sirt1. Using a peptide array harboring all known mammalian acetylation sites several novel substrates for Sirt1 were identified and shown that resveratrol and other small molecules can modulate Sirt1 dependent deacetylation of substrate peptides and that the effect is specific for the sequence of the substrate site. This finding reveals exciting possibilities for the development of new modulators targeting only specific substrates of Sirt1. These compounds can further be used in analyzing the functions of Sirtuins in vivo and can also serve as attractive leads for developing Sirt1 specific drugs. Studies on the mitochondrial isoform Sirt3 revealed that Zinc is essential for the structural integrity of Sirtuins. Investigations on Sirt5, also a mitochondrial Sirtuin appears to indicate that it is insensitive to nicotinamide (a physiological inhibitor of Sirtuins). Studies on the nucleolar isoform Sirt7 identified Thr224 to be phosphorylated, and play a role in the enzyme’s activity. The thermotoga maritima Sirtuin Sir2Tm was used as a model system for structural characterization of Sirt1. The crystal structure of Sir2Tm in complex with Ex-527, a potent Sirt1 inhibitor was solved, which combined with biophysical studies offers information about Ex-527 binding and inhibition. Close contacts between Ex-527 and some form of ADP-ribose, possibly the product O-acetyl-ADP-ribose (which is not yet fully verified) in the closed enzyme conformation prevent the release of products, thereby stalling the enzymatic reaction. These results offer insights into the isoform specific inhibition of Sirtuins by Ex-527 and provide information for further improvement of Sirt1 specific inhibitors.

Molecular detection and identification of phytoplasmas in sugarcane in Hawaii, Thailand, Cuba and Near East (2012)

Ziad Soufi

The Yellow leaf syndrome (YLS) had been first detected and described in Hawaiian sugarcane plantations. The polerovirus Sugarcane yellow leaf virus was identified as a causal agent of the syndrome; however there was no strict correlation between the degree of symptom expression and the virus titre. Therefore several surveys on breeding station sugarcane plants in Hawaiian Islands were done for Sugarcane yellow leaf phytoplasma (SCYLP), a bacterium which had been hypothesized to be also a causal agent of YLS. Two types of phytoplasmas were found in Hawaiian sugarcane cultivars mainly sugarcane white leaf phytoplasma (SCWL) which is a member in rice yellow dwarf group, in addition to aster yellows group. This was also true for sugarcane plants from Hawaiian plantations, which routinely use hot water-treatment for the seed cane cuttings. Sugarcane samples were obtained also from other countries including Cuba, Egypt, Syria and Thailand where sugarcane plants are also showing symptoms of yellowing or whiting. Aster yellows and X-disease phytoplasmas were found in Cuban cultivars whereas one sugarcane cultivar from Egypt contains grassy shoot phytoplasma that is a member in rice yellow dwarf group, but the other two Egyptian ones were phytoplasma-free. Syrian sugarcane was infected by phytoplasma that identified preliminary in rice yellow dwarf group. To our knowledge, this is the first report for the detection and identification of phytoplasma in sugarcane plants from Hawaii, Egypt and Syria. Our investigation on Thai sugarcane plants was in agreement with previous literature where sugarcane white leaf (SCWL) phytoplasma is associated with white leaf disease (Nakashima et al., 1994; Wongkaew et al., 1997). Q-PCR (real-time PCR) offers the opportunity to detect the phytoplasma in a sensitive, specific and quick manner, but that is not true for sugarcane plants with a very low titer of phytoplasma. Therefore, nested-PCR is better than qPCR for low titer phytoplasma detection and that is true for sugarcane yellow leaf phytoplasma disease. A BLAST search for the 16S rRNA gene sequences reported in this study showed that they shared 99 to 100% sequence identity with those of other phytoplasmas in the Aster yellows, X-disease and Rice yellow dwarf groups. However, no one of these identified strains can be described as a new “Candidatus Phytoplasma species”. On the other hand, Hawaiian sugarcane cultivar H78-7750 as a representative of Hawaiian breeding station sugarcane contains phytoplasma clustered to strain sugarcane white leaf (SCWL) phytoplasma, closely together with sugarcane white leaf phytoplasma from Taiwan (AY139874). It is possible to explain the occurrence of (SCWL) phytoplasma in Hawaiian Islands, by insect vectors or by infected stem cuttings which were obtained from other countries. Thai sugarcane contains phytoplasma isolate closely together with sugarcane white leaf phytoplasma from Myanmar. The transmission electron microscopic (TEM) studies revealed the presence of sugarcane white leaf phytoplasma only in phloem sieve tubes of diseased sugarcane leaves but not in adjacent cells to the sieve elements including companion cells and phloem parenchyma as well. According to ultrastructural observations under TEM, parenchymatic cells of bundle sheath and mesophyll tissue of affected leaves showed some alterations including accumulations of starch granules, increase plastoglobuli number and size in disorganized chloroplasts. Insect vectors of phytoplasmas are phloem feeders. Thus far, none of aphid species has been found to be a vector of phytoplasmas. Our tests showed also that black sugarcane aphids (Melanaphis Sacchari) were unable to transmit the phytoplasmas from infected sugarcane into the phytoplasma-free one. Hot water treatment has been proposed to cure plant material from phytoplasmas. Our tests showed that the appropriate hot water treatment, which recommended for phytoplasma elimination, is immersion of the sugarcane stem cuttings at 50°C for 60 min.

Ein Rahmenwerk für das Prozessdesign zur Identifikation, Klassifikation und Umsetzung von Anforderungen - Dargestellt an der Konzeption des Prozesskonfigurators (2012)

Stephanie Meerkamm

Prozessmanagement umfasst die Identifikation und Analyse der Unternehmensabläufe sowie deren Dokumentation und die Ausführung der Prozesse inklusive deren Steuerung. Dies sollte mit einer stetigen Verbesserung der Prozesse verbunden sein. Im Hinblick auf die konkrete Realisierung dieses Management-Ansatzes ist eine Fokussierung auf die Phase der Modellierung, welche die Identifikation sowie Dokumentation der Prozesse umfasst, zu beobachten. Dieser Phase geht das sog. Prozessdesign voraus. Auf Basis einer eingehenden Anforderungsanalyse erfolgt die Entwicklung und Evaluierung von Artefakten, wie zum Beispiel Konstrukte und/oder Methoden. Das vollständige Spektrum an Handlungsmöglichkeiten innerhalb des Prozessdesigns wird jedoch nur selten genutzt. Meist werden vorhandene (Standard-) Modellierungssprachen ausgewählt ohne diese in irgendeiner Art individuell zu gestalten. Dies wirkt sich oft negativ auf die Qualität der damit erstellten Prozessmodelle aus, aber auch auf die der Modellierung nachfolgenden Phasen des Management-Ansatzes wie Ausführung und Controlling. Im ersten Teil der vorliegenden Arbeit wurde ein daher methodisches Rahmenwerk für das Prozessdesign entwickelt. Aufgrund der engen Kopplung an die nachfolgende Phase der Prozessmodellierung wird als Grundlage eine Meta-Modell-Hierarchie verwendet, die die Entwicklung, Anpassung sowie Definition von (Meta) Modellen vorsieht. Diese wurde explizit um eine Designkomponente inklusive der initialen Anforderungsanalyse erweitert. Damit liegt ein flexibles Vorgehensmodell für die Durchführung der Designphase vor, das dabei vor allem auch die Definition von Modellierungssprachen vorsieht. Das gesamte Rahmenwerk ist zudem nicht auf eine bestimmte Modellierungssprache oder Anwendungsdomäne der Prozesse ausgerichtet, sondern generisch konzipiert. Im zweiten Teil der Arbeit wird ein Anwendungsfall für das zuvor entwickelte Rahmenwerk vorgestellt. Aus der beispielhaft identifizierten Menge an Anforderungen wurde die des Managements variantenreicher Prozessmodelle ausgewählt und das Konzept eines Prozesskonfigurators entwickelt. Im Hinblick auf die Verwendung der variantenreichen Prozessmodelle wurde ein gestufter Konfigurationsprozess entwickelt. Dieser leitet den Anwender auf der einen Seite durch den Konfigurationsprozess, auf der anderen Seite wird ihm ein Höchstmaß an Freiheit gewährt, wann er welche variantenbezogene Entscheidung treffen möchte. Für die Darstellung der Varianten in einem Modell wurde ein bereits existierendes Konzept zur Abbildung variantenreicher Strukturen in Form des sog. mereologischen Graphen verwendet, das an die Eigenschaften von Prozessen angepasst wurde. Damit kann die gewünschte kompakte sowie strukturierte Modellierung der Varianten in einem Modell realisiert werden. Dieses Modellierungskonzept konnte als Prototyp in einem entsprechenden Modellierungswerkzeug implementiert werden.

Klimawanderweg auf der Landesgartenschau in Bamberg 2012 (2012)

Thomas Foken

Effiziente parallele Implementierung eines expliziten Euler-Verfahrens für Grafikprozessoren durch Diamant-Tiling (2012)

Julien Kulbe

Die hier vorliegende Arbeit beschäftigt sich damit, das explizite Euler-Verfahren auf Grafikprozessoren zu optimieren. Dabei werden die Speicherhierarchien, lokale Datenwiederverwendung, Ausnutzung der Speicherbandbreite der GPU und die Synchronisierung zwischen Host und Device genauer untersucht. Dabei werden zwei Implementierungen näher betrachtet, das Diamant-Tiling und das lineare Verfahren, da sie sich gut eignen um die Optimierungen genauer zu untersuchen. Es stellt sich dabei heraus, dass Optimierungen wie die lokale Datenwiederverwendung und der optimale Zugriff auf den Speicher sich gegensätzlich verhalten. Ein Mischverfahren (das Waben-Tiling), dass dabei die Vorteile des linearen Verfahrens und des Diamant-Tilings vereint, führt daher zu den besten Laufzeiten.

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