Amphibian biodiversity in Taita Hills, Kenya

Species richness varies greatly across geographical regions. Eastern Arc Mountains (EAM) of Kenya and Tanzania is one of the global biodiversity hotspots. Despite this, high species diversity the explanatory factors have remained largely unexplored. Herein, this study first investigated amphibian species richness patterns in the EAM and particularly the reasons for the low richness in Taita Hills. It tested the hypothesis that the low richness is due to past forest loss or other factors. The results demonstrated that the regional species richness pattern was influenced largely by mean annual rainfall and not forest area. Secondly, using the 26 currently recorded amphibians in the Taita Hills, it investigated the relationship between amphibian species composition along anthropogenic habitat disturbance and elevation gradients. It tested the hypothesis that sites with similar environmental characteristics (temperature, rainfall and elevation), in close proximity and with similar disturbance levels (habitat types) harbour similar species composition. It was found that amphibian species composition differed in terms of elevation and was explained by both temperature and rainfall. Therefore sites with similar environmental characteristics, disturbance levels and in close proximity geographically have similar amphibian composition. Thirdly, diagnostic characters, distribution, basic life history characteristics and conservation status of all currently known amphibians in the Taita Hills were provided. Finally, first long term life history and ecological characteristics of a brevicipitid frog (Callulina sp) was provided. The results showed that this frog abundance and distribution is influenced mainly by mean monthly temperature, breeds during the long dry season and exhibit parental care. Results of this study strongly recommend increasing indigenous forest cover in order to enhance the conservation of the endemic indigenous forest associated amphibians such as Callulina sp, Boulengerula taitana and Boulengerula niedeni.

Sustainable development in Darjeeling Hills, India : ecological and socio-economic aspects for small-scale farmers with supportive observations from Kanagawa, Japan

Organic farming means a holistic application of agricultural land-use, hence, this study aimed to assess ecological and socio-economic aspects that show benefits of the strategy and achievements of organic farming in comparison to conventional farming in Darjeeling District, State of West Bengal, India and Kanagawa Prefecture/Kanto in Central Japan. The objective of this study has been empirically analysed on aspects of crop diversity, yield, income and sales prices in the two study regions, where 50 households each, i.e. in total 100 households were interviewed at farm-level. Therefore, the small sample size does not necessarily reflect the broad-scale of the use and benefit of organic farming in both regions. The problems faced in mountainous regions in terms of agriculture and livelihoods for small-scale farmers, which are most affected and dependant on their immediate environment, such as low yields, income and illegal felling leading to soil erosion and landslides, are analyzed. Furthermore, factors such as climate, soils, vegetation and relief equally play an important role for these farmers, in terms of land-use. To supplement and improve the income of farmers, local NGOs have introduced organic farming and high value organic cash crops such as ginger, tea, orange and cardamom and small income generating means (floriculture, apiary etc.). For non-certified and certified organic products the volume is given for India, while for Japan only certified organic production figures are given, as there are several definitions for organic in Japan. Hence, prior to the implementation of organic laws and standards, even reduced chemical input was sold as non-certified organic. Furthermore, the distribution and certification system of both countries are explained in detail, including interviews with distribution companies and cooperatives. Supportive observations from Kanagawa Prefecture and the Kanto region are helpful and practical suggestions for organic farmers in Darjeeling District. Most of these are simple and applicable soil management measures, natural insect repelling applications and describe the direct marketing system practiced in Japan. The former two include compost, intercropping, Effective Microorganisms (EM), clover, rice husk charcoal and wood vinegar. More supportive observations have been made at organic and biodynamic tea estates in Darjeeling District, which use citronella, neem, marigold, leguminous and soil binding plants for soil management and natural insect control. Due to the close ties between farmers and consumers in Japan, certification is often neither necessary nor wanted by the producers. They have built a confidence relationship with their customers; thus, such measures are simply not required. Another option is group certification, instead of the expensive individual certification. The former aims at lower costs for farmers who have formed a cooperative or a farmers' group. Consumer awareness for organic goods is another crucial aspect to help improve the situation of organic farmers. Awareness is slightly more advanced in Kanto than in Darjeeling District, as it is improved due to the close (sales) ties between farmers and consumers in Kanto. Interviews conducted with several such cooperatives and companies underline the positive system of TEIKEI. The introduction of organic farming in the study regions has shown positive effects for those involved, even though it still in its beginning stages in Darjeeling District. This study was only partly able to assess the benefits of organic agriculture at its present level for Darjeeling District, while more positively for the organic farmers of Kanto. The organic farming practice needs further improvement, encouragement and monitoring for the Darjeeling District farmers by locals, consumers, NGOs and politicians. The supportive observations from Kanagawa Prefecture and the Kanto region are a small step in this direction, showing how, simple soil improvements and thus, yield and income increases, as well as direct sales options can enhance the livelihood of organic farmers without destroying their environment and natural resources.

Design, synthesis and photochemical studies of stilbenoid dendrimers

Stilbenoid dendrimers with stilbene in the periphery and stilbene in periphery as well as core were synthesized by convergent approach except 2nd generation dendrimer with stilbene in the periphery as well as in core (D-5). All dendrimers were characterized by standard techniques such as 1H NMR, 13C NMR, MS and IR spectroscopy. The MALDI-TOF technique proved to be very helpful in the identification of the 2nd generation dendrimer (D-5) with a mass of 3231 a.m.u. The dendrimers were designed in such a way that an intramolecular photochemical CC bond formation was favored. As two stilbene units of the same molecule were close enough so they preferred an intramolecular cyclic process except for zero generation dendrimers. Apart from the cycloaddition, some E/Z isomerization and oligomer formation was also observed on irradiation. These processes were observed by 1H NMR and MALDI-TOF MS. The photochemical behavior was also studied by UV absorption spectroscopy. Irradiating by monochromatic light led to an initial E/Z isomerization and by prolonged irradiation, an irreversible cyclic structure was formed. The choice of the wavelength of incident light is very important as irradiation at 320 nm leads to a reversible E/Z isomerization and a non-reversible cyclobutane formation, but irradiation at 340 nm favors the one-way process E Z. The [2+2] cycloaddition of molecule Tm2De was also studied by irradiating thin films on a quartz surface. An AFM image was taken before irradiation, after 3 sec irradiation and after long irradiation (1 hour). AFM studies show that a short irradiation leads to a cyclic structure as formation of hills of about 20-30 nm on the surface. A prolonged irradiation leads to a CC cross linking which can be monitored on AFM images as disappearance of hills. The roughness goes back to an almost smooth surface. These results prove a very complex material transport, which accompanies the reaction in the surface region.

Weathering of Fe-bearing minerals under extraterrestrial conditions, investigated by Mössbauer spectroscopy

The weathering of Fe-bearing minerals under extraterrestrial conditions was investigated by Mössbauer (MB) spectroscopy to gain insights into the role of water on the planet Mars. The NASA Mars Exploration Rovers Spirit and Opportunity each carry a miniaturized Mössbauer spectrometer MIMOS II for the in situ investigation of Martian soils and rocks as part of their payload. The MER flight instruments had to be modified in order to work over the Martian diurnal temperature range (180 K – 290 K) and within the unique electronic environment of the rovers. The modification required special calibration procedures. The integration time necessary to obtain a good quality Mössbauer spectrum with the MIMOS II flight instruments was reduced by 30 % through the design of a new collimator. The in situ investigation of rocks along the rover Spirit's traverse in Gusev crater revealed weakly altered olivine basalt on the plains and pervasively altered basalt in the Columbia Hills. Correlation plots of primary Fe-bearing minerals identified by MB spectroscopy such as olivine versus secondary Fe-bearing phases such as nanophase Fe oxides showed that olivine is the mineral which is primarily involved in weathering reactions. This argues for a reduced availability of water. Identification of the Fe-oxyhydroxide goethite in the Columbia Hills is unequivocal evidence for aqueous weathering processes in the Columbia Hills. Experiments in which mineral powders were exposed to components of the Martian atmosphere showed that interaction with the atmosphere alone, in the absence of liquid water, is sufficient to oxidize Martian surface materials. The fine-grained dust suspended in the Martian atmosphere may have been altered solely by gas-solid reactions. Fresh and altered specimens of Martian meteorites were investigated with MIMOS II. The study of Martian meteorites in the lab helped to identify in Bounce Rock the first rock on Mars which is similar in composition to basaltic shergottites, a subgroup of the Martian meteorites. The field of astrobiology includes the study of the origin, evolution and distribution of life in the universe. Water is a prerequisite for life. The MER Mössbauer spectrometers identified aqueous minerals such as jarosite and goethite. The identification of jarosite was crucial to evaluate the habitability of Opportunity's landing site at Meridiani Planum during the formation of the sedimentary outcrop rocks, because jarosite puts strong constrains on pH levels. The identification of olivine in rocks and soils on the Gusev crater plains provide evidence for the sparsity of water under current conditions on Mars. Ratios of Fe2+/Fe3+ were obtained with Mössbauer spectroscopy from basaltic glass samples which were exposed at a deep sea hydrothermal vent. The ratios were used as a measure of potential energy for use by a microbial community. Samples from Mars analogue field sites on Earth exhibiting morphological biosignatures were also investigated.

The reconstruction of paleoclimate variability in Northern Germany, during marine isotope stage 5

In order to obtain a better understanding about the influence of post-depositional diagenesis on speleothem 230Th/U-ages and paleoclimate variability during Marine Isotope Stage (MIS) 5 in northern Germany, four stalagmites from the Riesenberghöhle (RBH) were investigated by thin section analysis, 230Th/U-dating as well as stable oxygen and carbon isotope and laser ablation inductively coupled mass spectrometry (LA-ICPMS) trace element analysis. The RBH is located in the Weser Hills and is one of the northernmost limestone caves in Germany.rnMulti collector (MC) ICPMS 230Th/U-ages and thin section analysis of the RBH stalagmites shows that some growth phases of the stalagmites were diagenetically altered after their deposition. The impact of post-depositional diagenesis (PDD) on the 230Th/U-ages is modeled, and potential processes leading to PDD are discussed. In this context, it is suggested that PDD may be induced by rapid climate change at the inception of the GIS.rnDespite of the dating uncertainties resulting from PDD, 230Th/U-dating shows that the RBH stalagmites grew during the Eemian and most of the Greenland Interstadials (GIS) during MIS 5. Thus, the growth phases of the RBH stalagmites might be related to a reorganization of the Atlantic Meridional Overturning Circulation (AMOC). The stable isotope (δ13C and δ18O) and the trace element variability of the stalagmites reflects rapid changes of past temperature and precipitation on millennial and sub-millennial timescales. These past climate changes can be amplified by orbitally forced variations of the July solar insolation at 65°N.