7. Impacts and Extinctions: Do They Match Up?

Determining the ‘dynamic biogeography’ of range collapse in threatened species is essential for effective conservation, but reconstruction of spatio-temporal patterns of population vulnerability and resilience can require use of non-standard ecological data such as historical archives. Pere David's deer or milu, one of the few living mammal species that has become extinct in the wild, is historically known only from a small captive herd of unknown provenance that survived until 1900 in the Imperial Hunting Park near Beijing, from which all living individuals are descended. Using ancient DNA analysis, we demonstrate that two fawns collected in 1868 from Hainan Island, off the southern Chinese mainland, represent the only known wild milu specimens and were sampled from probably the last wild population. The Hainan milu population shows extremely low genetic differentiation from descendants of the Beijing herd, suggesting that this now-extinct population may have been the source of the captive herd. This revised extinction model refutes the supposed long-term survival of a captive milu herd for centuries or millennia after final extinction of wild populations, highlighting the vulnerability of remnant mammal populations in the absence of proactive management and the importance of historical museum collections for providing unique new insights on evolution, biogeography and conservation. Milu experienced a pattern of final population persistence on an island at the periphery of their former range, consistent with the ‘range eclipse’ or ‘contagion’ model of range collapse, and matching the spatial extinction dynamics of other extinct mammals such as the thylacine and woolly mammoth.

1. The fraction of red in a red--green mixture matched to yellow increased as the intensities of the match constituents were increased sufficiently to bleach appreciable chlorolabe and erythrolabe. 2. All changes in matching found for a given normal trichromat, (i) with increase in the intensities of the matching components, (ii) as a function of time after the onset of very intense components, (iii) with change in the pupil region through which light enters the eye, and (iv) with change in the region of the retina under test, are consistent with the assumption that matching depends upon the absorption of light in three kinds of (individually colour blind) cones, each with its own visual pigment, provided that the lambda max densities of the latter can vary in the range 0.25--1.0 (common logarithmic units) depending upon the subject. 3. Individual differences in matching among normal (as well as among both varieties of red--green anomalous) trichromats, on the other hand, suggest that the extinction spectra of the cone pigments sensitive to long and medium wave lengths may differ from one trichromat to the next.

Oito melíponas (Melipona quadrifasciata) foram expostas a uma versão adaptada do procedimento de emparelhamento arbitrário com o modelo (matching-to-sample) em que a presença ou ausência de luz era empregada como estímulo condicional e as cores azul e amarelo como estímulos discriminativos. As cores eram apresentadas por semicírculos de material emborrachado sustentados por duas caixas retangulares de madeira, cada uma posicionada sobre uma caixa experimental a uma distância de 15 cm uma da outra. Cada lâmpada estava localizada sobreumadascaixas. As caixas experimentais eram de material acrílico com um painel superior de alumínio. Cada caixa era equipada com um alimentador operado externamente por uma haste e possuía um conjunto de pequenos orifícios no painel de alumínio que davam acesso ao xarope. Uma abelha podia voar da colméia para o aparato experimental e obter o xarope condicionalmente ao pouso direto sobre o estímulo de comparação definido como S+ em uma tentativa particular. Depois de instalada a linha de base, foram conduzidas sondas de simetria em extinção, intercaladas com tentativas de linha de base. Nas sondas, os discos coloridos tinham a função de estímulos condicionais (as duas caixas mostravam os discos de uma mesma cor, azul ou amarelo) e a presença e a ausência de luz eram usadas como estímulos discriminativos. As discriminações condicionais foram estabelecidas com todas as abelhas e seis entre as oito abelhas alcançaram o critério de simetria emergente (ao menos cinco tentativas entre seis). Estesresultadosestendemachadospréviossobrediscriminaçõescondicionaiseemparelhamento de identidade em abelhas. Contudo, no presente procedimento os estímulos tinham posição fixa, o que permite questionar se os comportamentos observados revelam propriedades simétricas (emergentes) ou apenas o controle por componentes de estímulos compostos (diretamente aprendidos). Palavras-chave: discriminação condicional, simetria, abelhas (Melipona quadrifasciata).

Researchers seek to design small meander line antennas for radio frequency identification (RFID) applications, while taking into consideration the achievement of best performance parameters of the antenna: impedance, return loss, voltage standing wave ratio (VSWR), radiation efficiency, gain, directivity and etc. Various planar meander line antennas were proposed which have the lowest resonant frequency and maximum radiation efficiencies for a fixed area, using multi-parameter optimization routines. The design in planar form with maximum radiation efficiency was optimized with the inclusion of matching structure for complex impedance matching with RF transceiver chip CC1101 for 433 MHz RFID applications. The design was also optimized for impedance match with commonly used transmission lines (50 ohms characteristic impedance) for 2.45 GHz applications. The antennas were fabricated using circuit in plastic (CiP) technique with screen printed silver conductor on 3mm FR4 and plastic substrates respectively. The technique allows the creation of a waterproof antenna for underground (mining geophysics, environmental monitoring, etc.) and underwater (swimmer communications, tidal monitoring, etc.) applications, because the antenna unit is completely sealed in a thin plastic coating. The impedance, band width, return loss and radiation efficiency of these antennas are the main parameters reported. Since the discovery of graphene, its electrical, mechanical and electronic properties have been explored. The high conductivity, low fabrication cost, flexibility, controllable isotropic and anisotropic behavior are some of the main properties of graphene which make the technology fascinating for electrical engineers and antenna designers. It can be used for antenna applications in the Terahertz frequency band either as a two dimensional, infinitely thin, planar sheet or in the form of one dimensional rolled up graphene known as carbon nanotubes. A pole-zero analysis on the input impedance of carbon nanotube (CN) dipole antennas with different lengths was used to explain the damped plasmonic resonances of these dipoles with increasing length. We used model based parameter estimation to approximate the input impedance of the antennas with a rational function in the complex frequency domain. Despite the dispersive nature of CNs, the imaginary part of the poles and zeros are respectively the integer multiples and odd multiples of the imaginary part of the first pole and zero. However, the real parts of impedance at the poles are almost constant, while the pattern was not observed for the real part of zeros. Carbon nanotube dipoles operating between 43-53GHz are well matched if the source impedance is much higher than 50 ohms, and even higher than 12.9kΏ. The fundamental resonances (f0) of carbon nanotube dipoles plotted versus their inverse-half-length (1/L) are linearly related, but the intercept of the fitted straight line is non-zero unlike that for perfect electric conductor (PEC) dipoles. This leads to a non-linear variation in wavelength scaling of CN dipoles. The resonant CN antennas are relatively much shorter than PEC dipoles of equivalent size. The fundamental properties of carbon nanotube straight wire dipole and Yagi- Uda antennas were determined using theoretical and numerical modelling. The insertion loss, radiation efficiency and Q-factor have been reported using classical Hallén’s-type integral equation, based on quantum mechanical conductivity. Contrary to the properties of metal antennas with dimensions less than 0.01 m, the addition of parasitic elements in a Yagi-Uda antenna with carbon nanotubes does not lead to significant changes in the radiation characteristics as the induced current in the parasitic elements is very small. The radiation efficiency of the Yagi-Uda antenna shows little change. The radiation efficiency of these antennas when compared with the Pfeiffer’s maximum efficiency bound lies well below the maximum efficiency limit. The 􀀊-factor of carbon nanotube antennas limited by their radiation efficiency was compared to the fundamental limits proposed by Chu and Thal and although the 􀀊 -factor of the nanotube antennas is very small, it is still larger than the fundamental limits. This analysis was also extended to carbon nanotube loop antennas operating in transmitting mode. The extinction properties of carbon nanotube loop antennas were also investigated and compared with ordinary metallic loop antennas. Since graphene is an ideal candidate for THz antenna applications due to its excellent electrical and mechanical properties, the conductivity and scattering properties of monolayer graphene were explored over a wide frequency range. Two monolayer graphene samples having different dimensions printed on a plastic (PET) substrate were measured using horn waveguides at microwave frequencies. Cascade matrix theory was applied to calculate scattering parameters of monolayer graphene patch on PET substrate assuming a frequency independent surface conductivity 􀀋􀀌􀀍 (manufacture’s specification) and to deembed the surface conductivity of graphene from measured transmission parameter s21. De-embedding 􀀋􀀌􀀍 from measured reflection parameter s11 was performed using transmission line theory. The theoretically modelled Sparameters were in good agreement with measured S-parameters of graphene. The measured conductivity of graphene using proposed formulations was in good agreement with the theory. The results were compared with previously published conductivity measurements of mono and multi layered graphene. This work on graphene and carbon nanotube antenna properties is a contribution towards THz antenna applications and we intend to extend this work to explore the properties of graphene meander line antennas which have not been reported to date.

A BSTRACTIndigenous ammonia-oxidizing bacteria (AOB) in a clay loam soil were extremely difficult to release from soil particles compared to most heterotrophic bacteria; less than 1% of indigenous AOB (estimated as potential ammonia oxidation rate) were extractable by the dispersion-density-gradient centrifugation technique. This is at least 10-fold less than the extractability of heterotrophic bacteria. Urea applications to the same soil induced a 5-fold increase in the potential ammonia oxidation rate, and this resulted in a much higher percentage (8%) extractability of AOB. Thus, the newly grown AOB in the urea-treated soil were less strongly attached to the soil particles. The contrast suggests that the strong attachment of indigenous AOB is a gradual process taking place due to a long residence time (infrequent/slow cell division) compared to heterotrophic organisms. However, the contrast could also reflect differences in species composition of the original AOB community and those growing in response to urea inputs. Specific detection of AOB in extinction dilution cultures was done by PCR and sequencing of the products. Considerable diversity was found within the genus Nitrosospira, but severe problems with the specificity of the primers were observed. Two allegedly AOB specific PCR primers pairs were used: one specific for Nitrosospira (SPIRA) and one which should encompass all AOB within the beta- Proteobacteria (GAOB). Only 33% of the cultures that gave PCR products with GAOB also gave products with the SPIRA primer pair, suggesting the presence of AOB other than Nitrosospira. However, the phylogeny based on the sequencing placed all the cultures in various clusters of the Nitrosospira clade, suggesting that the SPIRA primers do not match all members of the Nitrosospira genus. The cultures obtained from the urea-treated soil were different from the others in giving PCR products only with the SPIRA primers and not with the GAOB. Since sequencing also here confirmed the presence of Nitrosospira, these observations suggest that the GAOB primers do not match all AOB species.

In this thesis, we mainly discuss the fabrication and performance of the 4.25Gb/s optical module applied in optical communication network. The 4.25Gb/s optical module consists of transmitter and receiver. The transmitters are composed by laser driver IC and 850nm VCSEL; the laser drive IC mainly provides bias current and modulation current to make laser diode operate in suitable for extinction ratio and output optical power. The receivers are composed by photo detector and TIA and limiting amplifier. In order to archive performance of 4.25Gb/s, we further discuss components of radio frequency, including resistor, capacitor and inductor, we also analyze PCB layout to avoid electromagnetic crosstalk and noise; beside we try to find the better impedance match to avoid reflected signal. Eventually, we solved difficulty of PCB layout to put all the components into the module of small from factor, also measured 4.25Gb/s eye diagram to meet the standard of TI.

Matching to sample after extinction of observing responses.

The petrographic, mineralogical and geochemical features of the serpentinites recovered at the top of three seamounts located in the Izu-Bonin-Mariana forearc (South Chamorro, Site 1200, ODP Leg 195; Conical, Site 779A, Leg 125; Torishima, Site 784A, Leg 125) evidence a complex, multistage, evolution of the pristine mantle sequences, involving partial melting, reactive porous flow melt migration, subsolidus metamorphic re-equilibration under decreasing T and open system conditions, and, finally, lowgrade hydrothermal alteration processes. In spite of pervasive serpentinisation, there are areas in which the mantle mineral assemblages are preserved and provide information about the high-T petrologic evolution. The analysed peridotites varied from spinel harzburgite to orthopyroxene-bearing spinel dunite in early modal composition with clinopyroxene modal content mostly in the range of 0 to 2% by volume. Petrologic and geochemical modelling indicates that peridotites experienced up to 25% partial melting. Successively, they were percolated by ascending melts of variable composition. The melt-peridotite interaction is revealed by the following petrochemical features: 1) exsolved and deformed orthopyroxene porphyroclasts are partially replaced by secondary fine-grained assemblage consisting of Ol ± Opx ± Cpx: moreover, secondary clinopyroxene ubiquitously grows in correspondence of fractures across the orthopyroxene porphyroclasts; 2) interstitial clinopyroxene is concentrated locally in clusters or pseudo-veins; 3) the bulk rock major element variation does not match the trends expected for refractory residua after basalt removal; 4) the chemical compositions of the minerals is not correlated with the variation of the modal and chemical composition of bulk rock. Valuable information about the geochemical affinity of the migration melts are furnished by the trace element composition of clinopyroxenes (Cpx). The composition of the Cpx from the Torishima peridotites records the migration of extremely depleted melts with relatively enriched LREE and Sr content. As a whole the trace element fractionation of the putative liquids is consistent with that of boninitic melts. A different story is recorded by the Cpx from the South Chamorro and Conical peridotites. In particular, the geochemical composition of the Cpx from the South Chamorro samples is strongly heterogeneous. Thus, for sake of clarity, three different compositional groups can be recognised: Type1, 2 and 3. Type 1 Cpx are in equilibrium with a calculated liquid characterised by REE composition closely approaching that expected for melt increments produced by 15% fractional melting of spinel-facies depleted mantle. By contrast, Type 3 has Cpx characterised by an exceptional depletion in incompatible trace elements. C1-normalised REE patterns have the maximum at LuN (0.73-1.25). The low REE concentration is accompanied by very low Ti, Zr, Hf, Y, V and Sc concentration (e.g. Ti about 30 ppm). Type 2 Cpx has trace element contents in between those of Type 1 and 3. The REE patterns are characterised by a fractionation in the MREE-HREE region steeper than that expected for liquid produced by fractional melting of spinel facies assemblages (SmN/HoN=0.08-0.14; HoN/YbN = 0.21- 0.46) at the given HREE level (YbN = 2.1-2.7). A stronger MREE-HREE fractionation characterise the REE patterns of the Cpx from the Conical peridotites (SmN/HoN=0.05-0.08; HoN/YbN a 0.55), which show again the YbN in the range of 2.3-2.5. Similar REE fractionations have been documented in Cpx from abyssal peridotites (e.g Johnson, 1998; Hellebrand et al., 2002;), ophiolitic harzburgites (e.g. Kelemen et al., 1995; Dijkstra et al., 2003; Barth et al., 2003)and interstitial Cpx from “replacive” harzurgite-dunite bodies (e.g. Suhr et al., 1998, Suhr, 1999; Zanetti et al., 2005). Geochemical modelling indicates that this compositional character of the percolating melts can be explained by the following three petrologic processes: 1) polybaric evolution of their mantle source, involving an early phase under garnet- facies conditions followed by a second stage under spinel-facies ones; 2) transient composition acquired during the migration of extremely-depleted liquids (e.g. those calculated in equilibrium with Type 3 Cpx through a mantle column with a chemical composition approaching that of residual peridotite after 15% fractional melting. The meltperidotite interaction was mainly controlled by chromatographic- type chemical exchange; 3) transient composition acquired during the migration of less depleted liquids (e.g., those in equilibrium with Type 1 Cpx), through an extremely depleted mantle column. The melt-peridotite interaction involved a significant assimilation of the peridotite orthopyroxene. The model (3) is preferred, because it documents the overall petrochemical features shown by the South Chamorro and Conical peridotites. In conclusion, the strongly refractory characters acquired during the early partial melting episodes affection mantle peridotites from Izu-Bonin-Mariana supra-subduction zone has successively been overprinted by the migration of extremely depleted melts. The boninitic affinity recognised for the melts migrating through the mantle section in the Torishima Seamount area suggests that they were related to island- arc magmatism established in a MOR lithosphere. By contrast, the occurrence of depleted to extremely melts in the South Chamorro and Conical seamounts peridotites is more conceivable with the extinction of the magmatism in a MOR lithosphere.

Refining the ecological role of stingrays in coral reef ecosystems

Matching to sample after extinction of observing responses.

The Taiwan Red- and Yellow-Cypress are the most important coniferous trees of Taiwan and producing ideal construction timbers of particular usefulness in subtropical countries for anti-termites. Unfortunately these valuable trees, for some reasons to the others to be studied, are now tending to be exterminating. Hence the following problems call for a critical study; 1. Why is Taiwan Cypress endemic to Taiwan and not occurred in any other part of the world? 2. Why are they now exterminating? 3. How to maintain proper forest management and adequate silivicultural method to reserve these valuable species? The summaries and conclusions of the ecological and silvicultural studies of the above problems are as follows: 1. Peculiar climatic conditions occurred in this particular region having a combination effects of high relative humidity, cool temperature, moderate high annual precipitation, and the influence of prevailing typhoons, are the factors controlling the distribution area of these species. 2. Taiwan Red- and Yellow-Cypress are light demanding species. The thick and luxurious undergrowths of the forest floor impeding the fallen seeds in germination and growth and the cutting away of Taiwan Cypress in all the accessible regions and leaving too many over-matured trees bearing no more seeds for natural regeneration in all the accessible places cause a tendency of extermination. 3. The over-matured stands of forest should be cut off in a period of 120 years instead of 40 of the present management plan and to regulate the age class to the ”Normal Forest”, so that the rate of growth and drain shall be balanced and matched up with the 120-year rotation. 4. Artificial reforestation with seedlings raised from seeds of selected mother-seed trees is the only measure of conserving these valuable species from extinction.

The assembly history of massive galaxies is one of the most important aspects of galaxy formation and evolution. Although we have a broad idea of what physical processes govern the early phases of galaxy evolution, there are still many open questions. In this thesis I demonstrate the crucial role that spectroscopy can play in a physical understanding of galaxy evolution. I present deep near-infrared spectroscopy for a sample of high-redshift galaxies, from which I derive important physical properties and their evolution with cosmic time. I take advantage of the recent arrival of efficient near-infrared detectors to target the rest-frame optical spectra of z > 1 galaxies, from which many physical quantities can be derived. After illustrating the applications of near-infrared deep spectroscopy with a study of star-forming galaxies, I focus on the evolution of massive quiescent systems. Most of this thesis is based on two samples collected at the W. M. Keck Observatory that represent a significant step forward in the spectroscopic study of z > 1 quiescent galaxies. All previous spectroscopic samples at this redshift were either limited to a few objects, or much shallower in terms of depth. Our first sample is composed of 56 quiescent galaxies at 1 < z < 1.6 collected using the upgraded red arm of the Low Resolution Imaging Spectrometer (LRIS). The second consists of 24 deep spectra of 1.5 < z < 2.5 quiescent objects observed with the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE). Together, these spectra span the critical epoch 1 < z < 2.5, where most of the red sequence is formed, and where the sizes of quiescent systems are observed to increase significantly. We measure stellar velocity dispersions and dynamical masses for the largest number of z > 1 quiescent galaxies to date. By assuming that the velocity dispersion of a massive galaxy does not change throughout its lifetime, as suggested by theoretical studies, we match galaxies in the local universe with their high-redshift progenitors. This allows us to derive the physical growth in mass and size experienced by individual systems, which represents a substantial advance over photometric inferences based on the overall galaxy population. We find a significant physical growth among quiescent galaxies over 0 < z < 2.5 and, by comparing the slope of growth in the mass-size plane dlogRe/dlogM∗ with the results of numerical simulations, we can constrain the physical process responsible for the evolution. Our results show that the slope of growth becomes steeper at higher redshifts, yet is broadly consistent with minor mergers being the main process by which individual objects evolve in mass and size. By fitting stellar population models to the observed spectroscopy and photometry we derive reliable ages and other stellar population properties. We show that the addition of the spectroscopic data helps break the degeneracy between age and dust extinction, and yields significantly more robust results compared to fitting models to the photometry alone. We detect a clear relation between size and age, where larger galaxies are younger. Therefore, over time the average size of the quiescent population will increase because of the contribution of large galaxies recently arrived to the red sequence. This effect, called progenitor bias, is different from the physical size growth discussed above, but represents another contribution to the observed difference between the typical sizes of low- and high-redshift quiescent galaxies. By reconstructing the evolution of the red sequence starting at z ∼ 1.25 and using our stellar population histories to infer the past behavior to z ∼ 2, we demonstrate that progenitor bias accounts for only half of the observed growth of the population. The remaining size evolution must be due to physical growth of individual systems, in agreement with our dynamical study. Finally, we use the stellar population properties to explore the earliest periods which led to the formation of massive quiescent galaxies. We find tentative evidence for two channels of star formation quenching, which suggests the existence of two independent physical mechanisms. We also detect a mass downsizing, where more massive galaxies form at higher redshift, and then evolve passively. By analyzing in depth the star formation history of the brightest object at z > 2 in our sample, we are able to put constraints on the quenching timescale and on the properties of its progenitor. A consistent picture emerges from our analyses: massive galaxies form at very early epochs, are quenched on short timescales, and then evolve passively. The evolution is passive in the sense that no new stars are formed, but significant mass and size growth is achieved by accreting smaller, gas-poor systems. At the same time the population of quiescent galaxies grows in number due to the quenching of larger star-forming galaxies. This picture is in agreement with other observational studies, such as measurements of the merger rate and analyses of galaxy evolution at fixed number density.

Population increase during the mid-twentieth century as mortality declines in many developing nations were not matched with reductions in fertility, resulting in unprecedented growth rates. Concern with environmental change has come to the forefront primarily since 1970, with discernible levels of environmental degradation fueling public concern with the scope of contemporary environmental transformations and the advent of satellite imagery aiding environmental research. Rapid population growth and global environmental change are two issues that have received important public attention over the past several decades. It has become increasingly clear that human populations have a powerful effect on the environment and become a global public policy issue. Yet the exact relationship between population dynamics and the environment is complex. This paper reviews the environmental significances of population dynamics, based on current knowledge of the relationships between population factors and various aspects of the natural environment. This research is important for several reasons. • Compared with human-induced environmental changes of centuries past, the geographic scope of contemporary human-induced change is much larger. The rate of change is also much faster. The Earth's surface air temperature has increased by between 0.3 degrees and 0.6 degrees. Scientists have discovered that human activities as land-use change and fossil fuel use appear linked o increased concentrations of several atmospheric gases which warm the Earth's atmosphere and surface temperature.' As a result, humans appear partially responsible for environmental changes at the global scale-large-scale changes that have taken place in less than 200 years. • Some human-induced environmental changes have irreversible consequences. Ii is estimated that nearly 12 percent of mammals and 11 percent of bird species are currently threatened with extinction. In fact, the currently confronted episode of biodiversity loss is greater than the orld has experienced for the past 65 million years. Although some human activities, such as conservation programs, aim to preserve or enhance biodiversity, human-induced habitat destruction remains the primary cause of species decline. • The effects of contemporary environmental changes on humans are also increasing in scope. Global estimates suggest there may be as many as 25 million ”environmental refugees” -individuals who have migrated because they can no longer secure a livelihood from the land because of deforestation, desertification, soil erosion, and other environmental problems. • Human population continues to grow. In the face of rapid, large-scale, human-induced environmental change, human numbers increase each year by approximately 80 million. Those areas with continuing high fertility and resulting population growth are typically those with the least environmental resilience and those facing the greatest resource constraints. Although Earth already faces severe air pollution, water contamination, and other environmental ills, more than 90 percent of future population growth is projected to take place in these areas. This paper discusses the relationship between population and natural environmental change, the forces that mediate this relationship, and how population dynamics specifically affect climate change and land-use change and like to outline both sides of the policy debate that have emerged-those who would limit fertility and population growth in the developing world and those who need reduced consumption in the developed world. I also like to call for policymakers to pay increased attention to the role of population and forsake the search for one-step solutions to environmental problems.

Characterisation of ranaviral infection and its management in Australian lizards

Improving the aesthetic of solar thermal collectors would grant architects a huge potential for a perfect integration of solar panels into building facades: this can be achieved by coloured interference coatings on the cover glass. These coatings also open the possibility to match the colours of the collectors to those of other architectural components and design elements. An important boundary condition for the coloured filter production is however, to provide a sufficiently high solar transmittance. To deal with the latter, sophisticated numerical simulations are needed to improve the coloured filter design. In addition, a large variety of coating materials is important, ideally with huge differences in their refractive indices, while the absorption of all materials needs to be close to zero. This doctoral thesis focuses on the optical film design and the deposition of new coloured thin-film multilayers with an optimised energetic performance and an only little varying coloured reflection at different viewing angles. To access more directly the correlation between solar transmittance, light spectra and visual and energetic performance of the coatings, a thin-film simulation framework has been developed on the basis of Mathematica. New coating designs have reduced the number of parameters necessary to be adjusted and tuned during the coating-development process: this could help to shorten the prototype development phase on industrial coaters significantly as well as the whole coating-development cycle. Based on the new developed coloured filter designs, multilayer stacks were deposited via reactive magnetron sputtering. The deposited coatings exhibit a solar transmittance Tsol > 87%. For greenish colour hues even a Tsol up to 91% was reached, which corresponds to less than 1% loss in Tsol (respectively solar energy performance) in comparison to the uncoated glass substrate. Furthermore, the research deals with the deposition of low-refractive magnesium fluoride (MgF2) and MgF2 containing composites. Hereby, a novel deposition process by reactive magnetron sputtering was developed for MgF2 using a metallic magnesium target and a reactive gas mixture of oxygen (O2) and carbon tetrafluoride (CF4) diluted with argon. The obtained MgF2 films exhibit a very low refractive index of n = 1.382 at 550nm, which is congruent with the polycrystalline bulk, and only a very weak absorption in the whole solar range (300-2500nm). In addition, a novel approach to deposit Mg-F-Si-O composite materials by magnetron co- sputtering from compound MgF2 and silicon dioxide (SiO2) targets was performed. The obtained films show a two-phase system with nanocrystals of MgF2 embedded in a SiO2-rich amorphous matrix. The lowest achieved refractive index amounts to n = 1.424 at 550nm combined with a negligible extinction coefficient (k < 10-9). The investigated sputtered low-index materials open-up manifold possibilities for coloured filters. For instance, by adding a supplementary MgF2 inter-layer, a colour-invariant solar transmittance of Tsol = 85-85.7% could be achieved, as shown by numerical simulations. With this novel optical filter design it will be feasible to offer a whole colour palette for solar thermal collectors exhibiting all the same solar thermal energy performance.