GANs schön kompliziert: Applications of Generative Adversarial Networks

Scientific research progresses via model-building. Researchers attempt to build realistic models of real-world phenomena, ranging from bacterial growth to galactic motion, and study these models as a means of understanding these phenomena. However, making these models as realistic as possible often involves fitting them to experimentally measured data. Recent advances in experimental methods have allowed for the collection of large-scale datasets. Simultaneously, advancements in computational capacity have allowed for more complex model-building. The confluence of these two factors accounts for the rise of machine learning methods as powerful tools, both for building models and fitting these models to large scale datasets. In this thesis, we use a particular machine learning technique: generative adversarial networks (GANs). GANs are a flexible and powerful tool, capable of fitting a wide variety of models. We explore the properties of GANs that underpin this flexibility, and show how we can capitalize on them in different scientific applications, beyond the image- and text-generating applications they are well-known for. Here we present three different applications of GANs. First, we show how GANs can be used as generative models of neural spike trains, and how they are capable of capturing more features of these spike trains compared to other approaches. We also show how this could enable insight into how information about stimuli are encoded in the spike trains. Second, we demonstrate how GANs can be used as density estimators for extending simulation-based Bayesian inference to high-dimensional parameter spaces. In this form, we also show how GANs bridge Bayesian inference methods and variational inference with autoencoders and use them to fit complex climate models to data. Finally, we use GANs to infer synaptic plasticity rules for biological rate networks directly from data. We then show how GANs be used to test the robustness of the inferred rules to differences in data and network initialisation. Overall, we repurpose GANs in new ways for a variety of scientific domains, and show that they confer specific advantages over the state-of-the-art methods in each of these domains

Screening of in vitro derived mutants of banana against nematodes

Investigations were carried out to screen the in vitro derived mutants of banana cv. Robusta (Caveidish- AAA) and Rasthali (Silk- AAB) by using certain bio-chemical parameters including some enzyme activities. The mutants tested were Ro Im V4 6-1-1, Ro Im V4 6-1-2, Ro Im V4 6-2-1, Si Im V4 10-5-3, Si Im V4 4 6-2-5 along with respective susceptible checks (Robusta and Rasthali), tolerant check (Anaikomban- AA) and resistant check (Pisang Lilin- AA). Various biochemical assays used were total phenol, tannin content, lignin content, peroxidase, polyphenol oxidase, phenyl alanine ammonia lyase and ascorbic acid oxidase. The results revealed that the mutants namely Ro Im V4 6-1-1 and Si Im V4 10-5-3 were found to be resistant while the mutant Ro Im V4 6-2-1 was moderately resistant. The rest of the mutants namely Ro Im V4 6-1-2 and Si Im V4 6-2-5 were found to be susceptible to nematodes. The resistant and moderately resistant mutants of banana could be further used in breeding programmes as well as being recognized as potential cultivars of commerce.Key words: Banana, nematode, resistance, biochemical parameters, enzymes, screening

Spectroscopic analysis, first order hyperpolarizability, NBO, HOMO and LUMO analysis of 5-oxo-1-phenylpyrrolidine-3-carboxylic acid: Experimental and theoretical approach

5-oxo-1-phenylpyrrolidine-3-carboxylic acid has been synthesized and characterized by using single-crystal X-ray diffraction, FT-IR, 1HNMR, 13CNMR, UV-Visible spectroscopy and computational methods. The structure has been discussed and studied using density functional theory (DFT) at the theory level Becke3–Lee–Yang–Parr (B3LYP) functional and 6-31G (d, p) as basis set. The structural and thermodynamic parameters, electrostatic potential, electrophilicity (ω), chemical potential (µ), chemical hardness (η) and maximum amount of electronic charge transfer (∆Nmax) have been examined for this compound. Hyperconjugative interactions have been studied with the help of natural bond orbital analysis. Electric dipole moment, polarizability and first static hyperpolarizability values have been calculated. The correlation between experimental and theoretical proton and carbon NMR spectroscopic values has also been discussed. The experimental results are in good correlation with theoretical values

A comparative study of effective microorganisms (EM) and biocompost in the decomposition of coconut waste material

Lignocellulosic waste materials are recalcitrant in nature due to their interconnected complex polymer. Hence, composting of this type of lignocellulosic waste material is time consuming. This study aimed to compare the efficiency of effective microorganisms (EM) and biocompost in enhancing the decomposition of coconut waste.. A windrow heap of 3 x 2 x 1.5 m was prepared with alternate layers of coconut waste and cow dung. Two percent of effective microorganisms and biocompost were augment in each heap and the changes in the nutrient status of the compost across different composting time periods (15, 30, 45, 60, 75 and 90 days) were studied. It was observed that augmentation of both effective microorganisms and biocompost significantly reduced the organic carbon, while the total nitrogen, phosphorus and potassium increased on successive days of composting. At the end of study period, application of effective microoganisms (EM) reduced the organic carbon by 30.97%; and recorded the highest total nitrogen (1.20±0.024%), phosphorus (0.21±0.003%) and potassium (1.21±0.016%) content. Furthermore, augmenting effective microorganisms was highly effective, and the compost maturity was attained on the 60th day with a CN ratio of 17.8:1. The compost maturity test also validated that the effective microorganisms were more effective than biocompost in improving the rate of degradation of coconut waste and in producing mature compost of good quality

Characterizing Retinal Ganglion Cell Responses to Electrical Stimulation Using Generalized Linear Models

The ability to preferentially stimulate different retinal pathways is an important area of research for improving visual prosthetics. Recent work has shown that different classes of retinal ganglion cells (RGCs) have distinct linear electrical input filters for low-amplitude white noise stimulation. The aim of this study is to provide a statistical framework for characterizing how RGCs respond to white-noise electrical stimulation. We used a nested family of Generalized Linear Models (GLMs) to partition neural responses into different components-progressively adding covariates to the GLM which captured non-stationarity in neural activity, a linear dependence on the stimulus, and any remaining non-linear interactions. We found that each of these components resulted in increased model performance, but that even the non-linear model left a substantial fraction of neural variability unexplained. The broad goal of this paper is to provide a much-needed theoretical framework to objectively quantify stimulus paradigms in terms of the types of neural responses that they elicit (linear vs. non-linear vs. stimulus-independent variability). In turn, this aids the prosthetic community in the search for optimal stimulus parameters that avoid indiscriminate retinal activation and adaptation caused by excessively large stimulus pulses, and avoid low fidelity responses (low signal-to-noise ratio) caused by excessively weak stimulus pulses

Computational, Spectral & Single Crystal Studies of 4-chloro-N,Ndiphenylbenzamide

The present work comprises of spectroscopic, crystal and in silico studies of 4-chloro-N,Ndiphenylbenzamide. Synthesis of the compound was done followed by respective characterization by different spectral approaches. The in silico studies of title compound was further performed to ascertain various structural and geometrical parameters. All the studies were carried out at thetheory level B3LYP functional and 6-31G (d, p) as basis set. The geometry and other structural aspects of 4-chloro-N,Ndiphenylbenzamide were confirmed by X-ray diffraction

Suitability of vetiver (Vetiveria zizanioides) for removal of Cr (III) from tannery effluent using floating bed and rhizofiltration systems

Various physico-chemical methods have been employed in remediating heavy metals from wastewater, but most of them are expensive. While phytoremediation, is one cost-effective and eco-friendly technology, proves to be an alternate amongst which Vetiver, a unique tropical plant, is recognized for its large biomass and dense root system and has been proven for various remediation studies. The current research was conducted to assess the potential for Vetiver rhizofiltration of chromium. A pilot study was conducted in rhizobox wherein Vetiver was grown using sand as a medium and samples were collected from rhizobox port 1 and rhizobox port 2. Subsequently, the study was upscaled to a floating bed experiment. In both studies, Vetiver were grown under 500 mg L-1 Cr (III) solution and tannery effluent had a chromium concentration of 379 mg L-1 and the results were compared to control. Between the samples collected from port 1 and 2, the removal of chromium in port 1 was recorded to be higher than that of port 2. Moreover, the removal of chromium ions from the tannery effluent was relatively higher than the spiked solution. In both the ports, the highest removal of chromium concentration was recorded in T5 (Sand + Vetiver + Cr (III) @ 500 mg kg-1) with a removal percent of 12.59 and 10.38% in port 1 and 2, respectively. Hence, Vetiver grass has a great potential in removing pollutants like chromium from the wastewater.

Computational, Spectral & Single Crystal Studies of 4-chloro-N,Ndiphenylbenzamide

513-521The present work comprises of spectroscopic, crystal and in silico studies of 4-chloro-N,Ndiphenylbenzamide. Synthesis of the compound was done followed by respective characterization by different spectral approaches. The in silico studies of title compound was further performed to ascertain various structural and geometrical parameters. All the studies were carried out at thetheory level B3LYP functional and 6-31G (d, p) as basis set. The geometry and other structural aspects of 4-chloro- N,Ndiphenylbenzamide were confirmed by X-ray diffraction

Analysis of BAC-end sequences (BESs) and development of BES-SSR markers for genetic mapping and hybrid purity assessment in pigeonpea (Cajanus spp.)

<p>Abstract</p> <p>Background</p> <p>Pigeonpea [<it>Cajanus cajan </it>(L.) Millsp.] is an important legume crop of rainfed agriculture. Despite of concerted research efforts directed to pigeonpea improvement, stagnated productivity of pigeonpea during last several decades may be accounted to prevalence of various biotic and abiotic constraints and the situation is exacerbated by availability of inadequate genomic resources to undertake any molecular breeding programme for accelerated crop improvement. With the objective of enhancing genomic resources for pigeonpea, this study reports for the first time, large scale development of SSR markers from BAC-end sequences and their subsequent use for genetic mapping and hybridity testing in pigeonpea.</p> <p>Results</p> <p>A set of 88,860 BAC (bacterial artificial chromosome)-end sequences (BESs) were generated after constructing two BAC libraries by using <it>Hin</it>dIII (34,560 clones) and <it>Bam</it>HI (34,560 clones) restriction enzymes. Clustering based on sequence identity of BESs yielded a set of >52K non-redundant sequences, comprising 35 Mbp or >4% of the pigeonpea genome. These sequences were analyzed to develop annotation lists and subdivide the BESs into genome fractions (e.g., genes, retroelements, transpons and non-annotated sequences). Parallel analysis of BESs for microsatellites or simple sequence repeats (SSRs) identified 18,149 SSRs, from which a set of 6,212 SSRs were selected for further analysis. A total of 3,072 novel SSR primer pairs were synthesized and tested for length polymorphism on a set of 22 parental genotypes of 13 mapping populations segregating for traits of interest. In total, we identified 842 polymorphic SSR markers that will have utility in pigeonpea improvement. Based on these markers, the <it>first </it>SSR-based genetic map comprising of 239 loci was developed for this previously uncharacterized genome. Utility of developed SSR markers was also demonstrated by identifying a set of 42 markers each for two hybrids (ICPH 2671 and ICPH 2438) for genetic purity assessment in commercial hybrid breeding programme.</p> <p>Conclusion</p> <p>In summary, while BAC libraries and BESs should be useful for genomics studies, BES-SSR markers, and the genetic map should be very useful for linking the genetic map with a future physical map as well as for molecular breeding in pigeonpea.</p