Imitating reactive human behaviours in games using neural networks

Treball final de Grau en Disseny i Desenvolupament de Videojocs. Codi: VJ1241. Curs acadèmic: 2019/2020Deep learning has allowed to create neural networks that can play any game almost optimally. However, not so many have been trained to play like humans, or more concretely, like one specific person. Most people have recognizable ways of playing specific games, and imitating those behaviors would allow to create bots that don’t appear to be artificially generated. Also, by imitating one person behaviors it would be easy to create bots that play at the same level of quality. This document, which is a Final Degree Work report for the Bachelor’s Degree in Video Game Design and Development, presents some techniques to create neural networks that can imitate human behaviors using Unity’s ML Agents SDK, an analysis on what behaviors can be modeled more precisely, what are the training costs and how good are the results

Comparative transcriptional survey between laser-microdissected cells from laminar abscission zone and petiolar cortical tissue during ethylene-promoted abscission in citrus leaves

<p>Abstract</p> <p>Background</p> <p>Abscission is the cell separation process by which plants are able to shed organs. It has a great impact on the yield of most crop plants. At the same time, the process itself also constitutes an excellent model to study cell separation processes, since it occurs in concrete areas known as abscission zones (AZs) which are composed of a specific cell type. However, molecular approaches are generally hampered by the limited area and cell number constituting the AZ. Therefore, detailed studies at the resolution of cell type are of great relevance in order to accurately describe the process and to identify potential candidate genes for biotechnological applications.</p> <p>Results</p> <p>Efficient protocols for the isolation of specific citrus cell types, namely laminar abscission zone (LAZ) and petiolar cortical (Pet) cells based on laser capture microdissection (LCM) and for RNA microextraction and amplification have been developed. A comparative transcriptome analysis between LAZ and Pet from citrus leaf explants subjected to an <it>in-vitro </it>24 h ethylene treatment was performed utilising microarray hybridization and analysis. Our analyses of gene functional classes differentially represented in ethylene-treated LAZ revealed an activation program dominated by the expression of genes associated with protein synthesis, protein fate, cell type differentiation, development and transcription. The extensive repertoire of genes associated with cell wall biosynthesis and metabolism strongly suggests that LAZ layers activate both catabolic and anabolic wall modification pathways during the abscission program. In addition, over-representation of particular members of different transcription factor families suggests important roles for these genes in the differentiation of the effective cell separation layer within the many layers contained in the citrus LAZ. Preferential expression of stress-related and defensive genes in Pet reveals that this tissue is likely to be reprogrammed to prevent pathogen attacks and general abiotic stresses after organ shedding.</p> <p>Conclusion</p> <p>The LCM-based data generated in this survey represent the most accurate description of the main biological processes and genes involved in organ abscission in citrus. This study provides novel molecular insight into ethylene-promoted leaf abscission and identifies new putative target genes for characterization and manipulation of organ abscission in citrus.</p

Identification of a GCC transcription factor responding to fruit colour change events in citrus through the transcriptomic analyses of two mutants

14 páginas, 6 figuras, 3 tablas.[Background]: External ripening in Citrus fruits is morphologically characterized by a colour shift from green to orange due to the degradation of chlorophylls and the accumulation of carotenoid pigments. Although numerous genes coding for enzymes involved in such biochemical pathways have been identified, the molecular control of this process has been scarcely studied. In this work we used the Citrus clementina mutants 39B3 and 39E7, showing delayed colour break, to isolate genes potentially related to the regulation of peel ripening and its physiological or biochemical effects. [Results]: Pigment analyses revealed different profiles of carotenoid and chlorophyll modification in 39B3 and 39E7 mutants. Flavedo from 39B3 fruits showed an overall delay in carotenoid accumulation and chlorophyll degradation, while the flavedo of 39E7 was devoid of the apocarotenoid β-citraurin among other carotenoid alterations. A Citrus microarray containing about 20,000 cDNA fragments was used to identify genes that were differentially expressed during colour change in the flavedo of 39B3 and 39E7 mutants respect to the parental variety. The results highlighted 73 and 90 genes that were respectively up- and down-regulated in both mutants. CcGCC1 gene, coding for a GCC type transcriptional factor, was found to be down-regulated. CcGCC1 expression was strongly induced at the onset of colour change in the flavedo of parental clementine fruit. Moreover, treatment of fruits with gibberellins, a retardant of external ripening, delayed both colour break and CcGCC1 overexpression. [Conclusions]: In this work, the citrus fruit ripening mutants 39B3 and 39E7 have been characterized at the phenotypic, biochemical and transcriptomic level. A defective synthesis of the apocarotenoid β-citraurin has been proposed to cause the yellowish colour of fully ripe 39E7 flavedo. The analyses of the mutant transcriptomes revealed that colour change during peel ripening was strongly associated with a major mobilization of mineral elements and with other previously known metabolic and photosynthetic changes. The expression of CcGCC1 was associated with peel ripening since CcGCC1 down-regulation correlated with a delay in colour break induced by genetic, developmental and hormonal causes.Work was supported by grants AGL2007-65437-C04-01/AGR (Centro de Genómica) and AGL2009-11558 (L. Zacarías and M. J. Rodrigo) from the Ministerio de Educación y Ciencia of Spain.Peer reviewe

Early gene expression events in the laminar abscission zone of abscission-promoted citrus leaves after a cycleof water stress/rehydration: involvement of CitbHLH1

[EN] Leaf abscission is a common response of plants to drought stress. Some species, such as citrus, have evolved a specific behaviour in this respect, keeping their leaves attached to the plant body during water stress until this is released by irrigation or rain. This study successfully reproduced this phenomenon under controlled conditions (24h of water stress followed by 24h of rehydration) and used it to construct a suppression subtractive hybridization cDNA library enriched in genes involved in the early stages of rehydration-promoted leaf abscission after water stress. Sequencing of the library yielded 314 unigenes, which were spotted onto nylon membranes. Membrane hybridization with petiole (Pet)- and laminar abscission zone (LAZ)-enriched RNA samples corresponding to early steps in leaf abscission revealed an almost exclusive preferential gene expression programme in the LAZ. The data identified major processes such as protein metabolism, cell-wall modification, signalling, control of transcription and vesicle production, and transport as the main biological processes activated in LAZs during the early steps of rehydration-promoted leaf abscission after water stress. Based on these findings, a model for the early steps of citrus leaf abscission is proposed. In addition, it is suggested that CitbHLH1, the putative citrus orthologue of Arabidopsis BIGPETAL, may play major roles in the control of abscission-related events in citrus abscission zonesWork at the Centre de Genomica was supported by INIA grant RTA08-00065-00-00 and Ministerio de Ciencia e Innovacion-FEDER grants AGL2007-65437-C04-01, PSG-06-0000-2009-8, IPT-01-0000-2010-43, and AGL2011-30240. J.A. and P. M. were recipients of INIA predoctoral fellowships and M. C. and A. C. of INIA/CCAA and 'Ramon y Cajal' postdoctoral contracts, respectively. The help and expertise of E. Blazquez, I. Sanchis, and A. Boix are gratefully acknowledged.Agustí, J.; Gimeno, J.; Merelo, P.; Serrano Salom, R.; Cercós, M.; Conesa, A.; Talón, M.... (2012). Early gene expression events in the laminar abscission zone of abscission-promoted citrus leaves after a cycleof water stress/rehydration: involvement of CitbHLH1. Journal of Experimental Botany. 63:6079-6091. https://doi.org/10.1093/jxb/ers270S607960916

Ethylene-induced differential gene expression during abscission of citrus leaves

The main objective of this work was to identify and classify genes involved in the process of leaf abscission in Clementina de Nules (Citrus clementina Hort. Ex Tan.). A 7 K unigene citrus cDNA microarray containing 12 K spots was used to characterize the transcriptome of the ethylene-induced abscission process in laminar abscission zone-enriched tissues and the petiole of debladed leaf explants. In these conditions, ethylene induced 100% leaf explant abscission in 72 h while, in air-treated samples, the abscission period started later and took 240 h. Gene expression monitored during the first 36 h of ethylene treatment showed that out of the 12 672 cDNA microarray probes, ethylene differentially induced 725 probes distributed as follows: 216 (29.8%) probes in the laminar abscission zone and 509 (70.2%) in the petiole. Functional MIPS classification and manual annotation of differentially expressed genes highlighted key processes regulating the activation and progress of the cell separation that brings about abscission. These included cell-wall modification, lipid transport, protein biosynthesis and degradation, and differential activation of signal transduction and transcription control pathways. Expression data associated with the petiole indicated the occurrence of a double defensive strategy mediated by the activation of a biochemical programme including scavenging ROS, defence and PR genes, and a physical response mostly based on lignin biosynthesis and deposition. This work identifies new genes probably involved in the onset and development of the leaf abscission process and suggests a different but co-ordinated and complementary role for the laminar abscission zone and the petiole during the process of abscission

Differential expression of putative 9-cis-epoxycarotenoid dioxygenases and abscisic acid accumulation in water stressed vegetative and reproductive tissues of citrus

The relationship between ABA accumulation and the expression of putative carotenoid cleavage dioxygenase (CCD) genes in water-stressed vegetative and reproductive tissues from Clemenules mandarin (Citrus clementina) scions grafted on Cleopatra mandarin (Citrus reshni) rootstocks was investigated. Four full-length cDNAs (CcNCED3, CcCCD4a, CcCCD4b, and CcNCED5) closely related to the CCD group and in particular to the 9-cis-epoxycarotenoid dioxygenase (NCED) subfamily of Arabidopsis were cloned. In citrus seedlings drought-induced progressive ABA accumulation in roots, leaves and developing ovaries while re-hydration provoked sudden reduction of its levels. In these organs expression of CcCCD and CcNCED genes in normal conditions was low and similar. During the drought/re-watering cycles expression of CcNCED3, the major drought-induced gene, paralleled the pattern of ABA accumulation. In contrast, either minor or no up-regulation changes of CcNCED5 and CcCCD4a transcripts were observed. In green fruits, transcript levels of CcNCED3 and CcNCED5 in the flavedo (coloured fruit layer) were rather similar to those observed in developing ovaries. However, CcNCED5 expression dramatically increased at colour break and remained high in ripe fruit. Consistent with this observation, in the flavedo of detached ripe fruits a 37 C dehydration treatment increased in parallel levels of ABA and CcNCED5 transcripts. The above results showed that in Clemenules mandarin water stress induced specific up-regulation of CcNCED3 in photosynthetically active tissues such as leaves and developing ovaries. On the other hand, CcNCED5 was preferentially induced in Clemenules mandarin ripening fruits. (c) 2006 Elsevier Ireland Ltd. All rights reserved

Global analysis of gene expression during development and ripening of citrus fruit flesh. A proposed mechanism for citric acid utilization

Microarrays of cDNA have been used to examine expression changes of 7000 genes during development and ripening of the fruit flesh of self-incompatible Citrus clementina, a non-climateric species. The data indicated that 2243 putative unigenes showed significant expression changes. Functional classification revealed that genes encoding for regulatory proteins were significantly overrepresented in the up-regulated gene clusters. The transcriptomic study together with the analyses of selected metabolites highlighted key physiological processes occurring during citrus fruit development and ripening such as water accumulation, carbohydrate build-up, acid reduction, pigment substitutions (carotenoid accumulation and chlorophyll decreases) and ascorbic acid diminution. Often, the combined analyses strongly suggested prevalence of specific metabolic alternatives. This observation has been exemplified with the proposal for a mechanism for citrate utilization, a process of much importance in citrus industry. Microarray data validated by real-time RT-PCR suggested that citrate was sequentially metabolyzed to isocitrate, 2-oxoglutarate and glutamate. Thereafter, glutamate was both utilized for glutamine production and catabolyzed through the gamma-aminobutirate (GABA) shunt (GABA -&gt; succinate semialdehyde -&gt; succinate). This last observation appears to be of special relevance since it links the proton consuming reaction glutamate + H+ -&gt; GABA + CO2 with high acid levels. GG-MS determinations showed that glutamate was constant while GABA levels decreased at ripening in agreement with a feasible activation of the GABA shunt during acid catabolism. This suggestion provides a convincing explanation for the strong reduction of both citrate and cytoplasmatic acidity that takes place in citrus fruit flesh during development and ripening