Management of the purple sea urchin (Paracentrotus lividus, Lamark 1816) gametogenic cycle through the manipulation of photoperiod, temperature and feeding

Sea urchins’ gonads are considered as a delicacy, with certain countries such as Japan, Honk Kong and United States, having the highest import rate worldwide. The rising demand has led to an unsustainable exploitation of the wild sea urchins’ stocks. This situation led to the development of echinoculture, covering the ongoing demand and alleviating the fishing pressure. Past studies have shown encouraging results on the somatic and gonadal development, when the feed availability isn’t a limiting factor. In this study, 308 individuals of Paracentrotus lividus were tested in four (4) distinguished methods: a) natural (non-manipulated) photoperiod and temperature, corresponding to the experiment’s time period, with natural diet (Ulva spp.), b) natural photoperiod and temperature with a formulated diet (pellets), c) manipulated photoperiod and temperature with natural diet (Ulva spp.), corresponding to the environmental conditions starting from January until June and d) manipulated conditions with pellets as feed. Data regarding monthly: feed intake, gonadosomatic index and the state of the gonad maturation, were gathered and statistically analyzed. GSI was increased in all the groups regardless of the treatment. Significant differences were found in the sea urchins fed with pellets which had the highest final GSI, compared to the sea urchins fed with Ulva spp. There was no correlation between GSI and the natural or manipulated environmental conditions. The sea urchins in manipulated photoperiod and temperature, after the spawning period in December 2021 – January 2022, had advanced in their gametogenic cycle, compared to the sea urchins in natural environmental conditions. Overall, the experiment verified past studies in were by manipulating the rearing conditions (photoperiod, water temperature), the gametogenic cycle of P. lividus progressed faster, supporting the world echinoculture industry.A indústria da aquacultura tem sido capaz de cobrir a crescente procura global de produtos da pesca. Em 2018, a indústria aquícola mundial atingiu o recorde de 114,5 milhões de toneladas de peso vivo, com valor de mercado de 263,6 milhões de dólares. O crescimento da aquacultura é notável, partindo de 25,7% em 2000 e chegando a 45% em 2018. É evidente que os produtos da aquacultura têm grande impacto nas estratégias globais de segurança alimentar e nutrição.As gónadas dos ouriços-do-mar são consideradas uma iguaria, sendo o Japão, Honk Kong e Estados Unidos, os países com maior taxa de importação em todo o mundo. Do ponto de vista nutricional, este produto é considerado uma valiosa fonte de proteínas, ácidos gordos (nomeadamente os poliinsaturados, PUFA), carbohidratos e carotenóides. O aumento da procura destes organismos para consumo levou a uma exploração insustentável das populacões de ouriços-do-mar selvagens. Esta situação levou ao desenvolvimento da equinocultura, cobrindo a procura e aliviando a pressão da pesca. Pesquisas anteriores mostraram resultados animadores sobre o desenvolvimento somático e das gonadas, quando a disponibilidade alimentar não é um fator limitante. Além disso, parâmetros físicos como o fotoperíodo e temperatura podem afetar positivamente o crescimento das gónadas, com a temperatura a apresentar maior significância neste aumento. Neste estudo, são investigadas as condições ambientais e de alimentação adequadas na equinocultura de Paracentrus lividus, em condições de laboratório no período de outubro de 2021 a fevereiro de 2022. No ensaio, 308 indivíduos de P. lividus foram sujeitos a 4 tratamentos: a) fotoperíodo (não manipulado) e temperatura naturais, durante o período de tempo do ensaio, com dieta natural (Ulva spp., NUC), b) fotoperíodo e temperatura natural, com dieta formulada (“pellets”, NPC), c) fotoperíodo e temperatura manipulados (simulando as condições ambientais de janeiro a junho) e com dieta natural (Ulva spp., MUC), e d) condições manipuladas com “pellets” como ração (MPC). Para as condições ambientais naturais, o fotoperíodo foi de 9,4L:14,6D a 10,4L:13,6D, enquanto a temperatura variou entre 13,92-19,22°C. Em relação às condições ambientais manipuladas, o fotoperíodo variou entre 10,1L:13,9D e 13,5L:11,5D. A temperatura para as condições manipuladas foi de 14,58-18,01 °C. Para cada tratamento foram estabelecidas três (3) replicados, em tanques com dimensões de 0,45*0,7*0,45 m totalizando um volume de 100 L. Os ouriços-do-mar foram colocados dentro de caixas plásticas de dimensões 0,57*0,38*0,08 m, com uma rede plástica divisora no meio para diferenciar os ouriços-do-mar consoante o seu regime de alimentar. A temperatura da água foi regulada com o uso de refrigeradores-aquecedores programados e o fotoperíodo com o uso de uma cubertura preta e iluminação temporizada. A renovação da água foi de aproximadamente 112,5 L/h, com arejamento garantido com pedras difusoras. A temperatura da água e os níveis de oxigénio foram medidos diariamente com o auxílio de uma sonda multi-paramétrica da Estação Piloto de Piscicultura de Olhão (EPPO). Os “pellets” utilizados neste ensaio, foram desenvolvidos e fabricados pela SPAROS, I&D (Olhão, Portugal), enquanto que a Ulva spp. foi recolhida de um tanque de terra nas instalações da EPPO. Os ouriços-do-mar foram alimentados uma vez a cada 3-4 dias e a quantidade de ração foi adaptada de acordo com a biomassa total existente. A amostragem mensal foi realizada determinando o peso total de cada replicado. Foram recolhidos 5 indivíduos para avaliação gonadossomática e para processamento histológico e posterior análise. O peso total das gónadas foi registado. Os estados de desenvolvimento das gónadas de P. lividus foram identificados de acordo com a escala de maturação de Byrne (1990) em seis estados: recuperação (I), crescimento (II), prematuro (III), maduro (IV), postura (V) e pós-postura (VI) Mensalmente foram recolhidos e analisados estatisticamente os seguintes dados: consumo de ração, índice gonadossomático e estado de maturação das gónadas. Os dados foram testados para normalidade (Shapiro-Wilk) e para variâncias iguais (teste de Levene) antes de compará-los para diferenças significativas. Em continuação para as medidas de consumo de ração e GSI, o teste t de Welch Two Sample e o teste não paramétrico de Kruskal-Wallis foram usados com um contraste adicional post hoq ANOVA Tukey, quando o teste não paramétrico foi significativo (p<0,05). Os ouriços-do-mar alimentados com ração granulada apresentaram um consumo de ração menor em comparação com os ouriços-do-mar alimentados com Ulva spp., sendo o consumo médio máximo de ração de 0,427 e 1,406 g/dia/SU, respectivamente. Este resultados pode ser atribuído ao fato de que os ouriços-do-mar, devido a um mecanismo de adaptação, poderem consumir menos ração e atingir o crescimento adequado quando a ração é rica em proteína bruta. Não houve diferenças estatisticamente significativas em relação ao consumo de ração e às condições ambientais (naturais e manipuladas). O Indice Gonadossomático (IGS) inicial foi de 0,63 ± 0,44%. Sendo que os ouriços-do-mar alimentados com ração apresentaram maiores valores de IGS, quando comparados ao grupo com Ulva spp. O maior valor final foi medido nos ouriços-do-mar alimentados com pellets em condições manipuladas (16,81 ±1,82%), enquanto o menor foi observado nos ouriços-do-mar alimentados com Ulva spp. em condições manipuladas (11,08 ±4,41). Os fagócitos nutritivos nas gónadas podem acumular os nutrientes de forma mais eficiente, quando a dieta contém altas percentagens de proteína. Não se verificou efeito significativo das condições ambientais naturais ou manipuladas no IGS. Após o período de desova (dezembro de 2021 a janeiro de 2022), o IGS não diminuiu significativamente, o que pode ser atribuído ao duplo papel das gónadas como órgãos reprodutivos e armazenamento de nutrientes. Em relação à maturação das gónadas os dados foram analisados qualitativamente. A amostragem inicial foi composta por 8 indivíduos, tendo-se verificado que todos eram imaturos. A razão sexual (masculino:feminino) foi de 1:1. Durante o período de dezembro de 2021 a janeiro de 2022, através da análise histológica verificou-se a ocorrência de desova não registada. A manipulação das condições ambientais (temperatura, fotoperíodo) promoveram um aceleramento do ciclo gametogenético. Durante o mês de janeiro de 2022, para o tratamento com as condições ambientais manipuladas para os dois regimes alimentares (Ulva spp. e ração) tiveram menos individuos em avançado estado de maturação. Assim, para os grupos alimentados com Ulva spp. (MUC) os estados de desenvolvimento encontrados foram (I, II, III e VI), enquanto que para o grupo alimentado com ração (MPC) os estados foram (I, II e VI). Em contraste, para o mesmo mês houve mais estados presentes para o tratamento com condições ambientais naturais no regime alimentar Ulva spp (NUC). Nos grupos (NUC) e (NPC), os estados de maturação presentes foram I-IV e II-VI, respectivamente. Com a manipulação das condições ambientais, os ouriços-do-mar conseguiram progredir mais rapidamente e ter um fenómeno de "estratificação" menos evidente durante o mês de janeiro, promovendo a sincronização das gónadas. Esta técnica de reprodução pode produzir resultados positivos na produção indústrial de ouriços-do-mar. Trabalhos futuros deverão ser concentrados no impacto das condições ambientais (vários regimes de temperatura e fotoperíodo), em comparação com condições constantes, para facilitar a anáolise de dados

The Shield & Sword of the State? The Effect of Conscription and Secret Police on Civil-Military Relations

From Nigeria (2010) to Turkey (2016), and Mali (2020), coups continue to threaten government stability. In 2021, even the US democratic process was endangered when a mob stormed the capitol in a sui generis coup. The following thesis draws attention to the previously unrecognized effect of compulsory military service and secret police on civil-military relations and coup risk. In the first chapter, co-authored with Pr. Tobias Böhmelt‬ and Dr. Zorzeta Bakaki, we examine how conscription increases public trust for the armed forces in European democracies. We argue that conscription, more so than voluntary-recruitment systems, can reach out to and socialize larger segments of the society in line with the military’s values either directly - through personal involvement, or indirectly – from individuals directly exposed to the military to third persons. The second chapter explores how conscription increases the likelihood of a coup attempt in anocracies. The chapter advances the argument that conscription improves the ties of the armed forces with society and enables interest groups to collaborate with the armed forces against the anocratic government which is unable to overcome the political instability innate to those regimes. Third chapter investigates how secret police in autocracies decrease the willingness and opportunity of military officers to stage a coup. Specifically, secret police weaken societal-military ties by identifying and sanctioning dissidents through sophisticated espionage operations. Therefore, while conscription increases societal-military ties, secret police produce the opposite effect. The study concludes that conscription increases public trust to the armed forces in European democracies, however, the institution also produces an undesirable side-effect in anocracies, namely increased coup risk. To the contrary, secret police in autocracies is found to decrease the probability of a coup attempt against the government. Consequently, the thesis contributes to the literature on civil-military relations by bringing attention to previously unappreciated aspects of civil-military relations. Likewise, the thesis demonstrates that the study of essential societal-military institutions, like conscription, through new lens may enrich our understanding of civil-military relations

Employing surfactant-assisted hydrothermal synthesis to control CuGaO2 nanoparticle formation and improved carrier selectivity of perovskite solar cells

Delafossites like CuGaO2 have appeared as promising p-type semiconductor materials for opto-electronic applications mainly due to their high optical transparency and electrical conductivity. However, existing synthetic efforts usually result in particles with large diameter limiting their performance relevant to functional electronic applications. In this article, we report a novel surfactant-assisted hydrothermal synthesis method, which allows the development of ultrafine (~5 nm) monodispersed p-type CuGaO2 nanoparticles (NPs). We show that DMSO can be used as a ligand and dispersing solvent for stabilizing the CuGaO2 NPs. The resulting dispersion is used for the fabrication of dense, compact functional CuGaO2 electronic layer with properties relevant to advanced optoelectronic applications. As a proof of concept, the surfactant-assisted hydrothermal synthesized CuGaO2 is incorporated as a hole transporting layer (HTL) in the inverted p-i-n perovskite solar cell device architecture providing improved hole carrier selectivity and power conversion efficiency compared to conventional PEDOT:PSS HTL based perovskite solar cells

Το ταξίδι στη Δύση στον 21ο αιώνα. Μια αναλυτική προσέγγιση της κινεζικής πολιτικής στους διεθνείς οργανισμούς στη νέα χιλιετία

Στόχος της συγκεκριμένης πτυχιακής εργασίας είναι η χαρτογράφηση της κινεζικής πολιτικής στη διεθνή οργάνωση στους τομείς της ασφάλειας, της οικονομίας και του περιβάλλοντος. Υπόθεση εργασίας είναι το κατά πόσον η Λαϊκή Δημοκρατία της Κίνας αποδέχεται τους θεσμούς της διεθνούς οργάνωσης και τους αξιοποιεί για την προώθηση των συμφερόντων της. Στον τομέα της ασφάλειας, η Κίνα προασπίζει μέσα από το Συμβούλιο Ασφαλείας κρίσιμα εθνικά της συμφέροντα, όπως το ζήτημα της Ταϊβάν και η αρχή της κρατικής κυριαρχίας. Η κινεζική δραστηριοποίηση στις ειρηνευτικές αποστολές του ΟΗΕ δηλώνει την ανάληψη της Κίνας ενός πιο ενεργού ρόλου στη διεθνή διακυβέρνηση και ικανοποιεί ιδεαλιστικά και ρεαλιστικά κίνητρα. Στον τομέα της οικονομίας, η Κίνα λειτουργεί στον ΠΟΕ ως αντίπαλο δέος στα αναπτυγμένα κράτη, παγώνοντας τις διαπραγματεύσεις στο Γύρο της Ντόχα, ενώ αποδέχεται τη διεθνή δικαιοδοσία και το πλαίσιο λειτουργίας του Μηχανισμού Επίλυσης Διαφορών αξιοποιώντας τον προς όφελός της. Στις διαπραγματεύσεις για την κλιματική αλλαγή η Κίνα αναδιαμορφώνει την περιβαλλοντική διακυβέρνηση κατέχοντας μία ηγεμονική θέση σε αυτόν τον τομέα πολιτικής. Τελικώς, η Κίνα φαίνεται να συνειδητοποιεί ότι διαμέσου της ενεργής συμμετοχής της στους διεθνείς οργανισμούς, αποδεχόμενη ταυτοχρόνως τις διεθνείς νόρμες και κανόνες που τους διέπουν, περιέρχεται σε μία κατάσταση αμοιβαίου οφέλους ανάμεσα στην ίδια και στη διεθνή κοινωνία και διασφαλίζει την ειρηνική της άνοδο.Goal of this dissertation is to map the Chinese policy in International Organization, in the sectors of security, economy and environment. This research examines the extent of People&apos;s Republic of China&apos;s acceptance of the institutions of international organizations while utilizing them in order to promote its interests. On security, China defends through the Security Council, vital national interests, such as the issue of Taiwan and the principle of state sovereignty. Active Chinese participation in the UN Peacekeeping Operations asserts the growing chinese role in global governance and promotes idealistic and realistic interests. In the WTO, China, combining forces with other emerging economies, counter-balances developed countries. Furthermore, China accepts the jurisdiction and working framework of WTO&apos;s Dispute Settlement Mechanism to her advantage. Regarding climate change negotiations, China&apos;s dominant position in this sector of policy, has allowed the country to reshape international response to the problem closer to its own vision. Finally, China has come to realise that through active participation in international organizations it cements a mutual gain relationship with the international society. Accepting international norms, international institutions and the framework of rules that guides them safeguards chinese peaceful rise in the international system

Room Temperature Nanoparticulate Interfacial Layers for Perovskite Solar Cells via solvothermal synthesis

We present a solvothermal synthetic route to produce monodispersed CuO nanoparticles (NPs) in the range of 5-10 nm that can be used as hole selective interfacial layer between indium tin oxide (ITO) and perovskite active layer for p-i-n perovskite solar cells by a spin casting the dispersions at room temperature. The bottom electrode interface modification provided by spherical CuO-NPs at room temperature promotes the formation of high quality perovskite photoactive layers with large crystal size and strong optical absorption. Furthermore, it is shown that the nanoparticulate nature of the CuO hole transporting interfacial layer can be used to improve light manipulation within perovskite solar cell device structure. The corresponding p-i-n CH3NH3PbI3-based solar cells show high Voc values of 1.09 V, which is significantly higher compared to the Voc values obtained with conventional PEDOT:PSS hole selective contact based perovskite solar cells

The Effect of Hole Transporting Layer in Charge Accumulation Properties of p-i-n Perovskite Solar Cells

The charge accumulation properties of p-i-n perovskite solar cells were investigated using three representative organic and inorganic hole transporting layer (HTLs): a) Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS, Al 4083), b) copper-doped nickel oxide (Cu:NiOx) and c) Copper oxide (CuO). Through impedance spectroscopy analysis and modelling it is shown that charge accumulation is decreased in the HTL/Perovskite interface, between PEDOT:PSS to Cu:NiOx and CuO respectively. This was indicative from the decrease in double layer capacitance (Cdl) and interfacial charge accumulation capacitance (Cel), resulting in an increase to recombination resistance (Rrec), thus decreased charge recombination events between the three HTLs. Through AFM measurements it is also shown that the reduced recombination events (followed by the increase in Rrec) is also a result of increased grain size between the three HTLs, thus reduction in the grain boundaries area. These charge accumulation properties of the three HTLs have resulted in an increase to the power conversion efficiency between the PEDOT:PSS (8.44%), Cu:NiOx (11.45%) and CuO (15.3%)-based devices

Long Thermal Stability of Inverted Perovskite Photovoltaics Incorporating Fullerene-based Diffusion Blocking Layer

In this article, the stability of p-i-n perovskite solar cells is studied under accelerated heat lifetime conditions (60 oC ,85oC and N2 atmosphere). By using a combination of buffer layer engineering, impedance spectroscopy and other characterization techniques, we propose the interaction of the perovskite active layer with the top Al metal electrode through diffusion mechanisms as the major thermal degradation pathway for planar inverted perovskite photovoltaics (PVs) under 85oC heat conditions. We show that by using thick solution processed fullerene buffer layer the perovskite active layer can be isolated from the top metal electrode and improve the lifetime performance of the inverted perovskite photovoltaics at 85 oC. Finally, we present an optimized solution processed inverted perovskite PV device using thick fullerene-based diffusion blocking layer with over 1000 hours accelerated heat lifetime performance at 60oC

Nanoparticulate Metal Oxide Top Electrode Interface Modification Improves the Thermal Stability of Inverted Perovskite Photovoltaics

Solution processed {\gamma}-Fe2O3 nanoparticles via the solvothermal colloidal synthesis in conjunction with ligand-exchange method are used for interface modification of the top electrode in inverted perovskite solar cells. In comparison to more conventional top electrodes such as PC(70)BM/Al and PC(70)BM/AZO/Al, we show that incorporation of a {\gamma}-Fe2O3 provides an alternative solution processed top electrode (PC(70)BM/{\gamma}-Fe2O3/Al) that not only results in comparable power conversion efficiencies but also improved thermal stability of inverted perovskite photovoltaics. The origin of improved stability of inverted perovskite solar cells incorporating PC(70)BM/ {\gamma}-Fe2O3/Al under accelerated heat lifetime conditions is attributed to the acidic surface nature of {\gamma}-Fe2O3 and reduced charge trapped density within PC(70)BM/ {\gamma}-Fe2O3/Al top electrode interfaces.Comment: 24 pages, 11 figure

How Mechanization Shapes Coups

Civil-military relations are characterized by a fundamental dilemma. To lower coup risk, leaders frequently empower the military, which satisfies the armed forces with the status quo and enables them to fight against threats challenging the civilian leadership. Simultaneously, a too powerful military itself constitutes a potential threat that is capable of overthrowing the government. Our research adds to this debate by examining the impact of mechanization, that is, the degree to which militaries rely on armored vehicles relative to manpower, on coup risk. We discuss several (opposing) mechanisms before developing the theoretical expectation that higher levels of mechanization should lower the likelihood of a coup due to the increased costs of coup execution. Empirical evidence strongly supports this claim and, thus, contributes to our understanding of the emergence of coups as an essential breakdown of civil-military relations, while adding to the debate surrounding the many trade-offs leaders face when coup-proofing their regimes

Antimony doped Tin Oxide/Polyethylenimine Electron Selective Contact for reliable and light soaking-free high Performance Inverted Organic Solar Cells

We have demonstrated a high-performance low temperature solution processed electron selective contact consisting of 10 at% antimony doped tin oxide (ATO) and the neutral polymer polyethylenimine (PEI). Inverted organic photovoltaics (OPVs) utilizing ATO/PEI as electron selective contact exhibited high power conversion efficiencies for both the reference P3HT: PCBM and the non-fullerene based P3HT- IDTBR active layer OPV material systems. Importantly it is shown that the proposed ATO/PEI carrier selective contact provides light soaking-free inverted OPVs. Furthermore, by increasing the thickness of ATO layer from 40 to 120 nm the power conversion efficiency of the corresponding inverted OPVs remain unaffected a parameter which indicates the potential of the proposed ATO/PEI carrier selective contact for high performance light-soaking-free and reliable roll-to-roll printing solutions processed inverted OPVs.Comment: 20 pages, 4 figures, 2 table