Compared physiological performances of Caulerpa prolifera and native seagrasses of Ria Formosa

Seagrasses are among the most important and also mostly threatened ecosystems in the marine environment. Seagrass loss can occur in their competition with other macrophytes, like invasive macroalgae. These pose a serious threat and present numerous consequences to their new environment. Among those that can affect seagrasses, Caulerpa sp. are one of the most recognized genus. Different mechanisms can grant them a competitive advantage over seagrasses, resulting in partial or even complete replacement. Therefore, knowing how Caulerpa sp. functions and interacts with a new environment is crucial, especially in a system like Ria Formosa, where three of the four European seagrass species can be found. We aimed to study and compare different photo-physiological components of the subtidal seagrasses Cymodocea nodosa and Zostera marina and of the macroalgae Caulerpa prolifera along diel cycles, while at the same time identifying possible consequences of their interaction, using a mesocosm experiment. The first experiment was performed over the course of two days (48 hour cycle), collecting samples for biochemical analysis at pre-dawn and solar noon at the end. The mesocosm experiment involved planting Z. marina and C. prolifera separately and mixed. After 4 weeks, photosynthetic performance was tested using photosynthesis-irradiance curves and rapid light curves, and samples for biochemical analysis were collected. The seagrasses revealed higher effective quantum yield and non-photochemical quenching, mainly related to their xanthophyll pigments, while C. prolifera displayed a typical shade-adapted response. Furthermore, it displayed a different carbohydrate usage regime, which was related to its higher respiration rates. Although no different overall photosynthetic performance was detected in the interaction of the species, starch content in Z. marina rhizomes was significantly lower when C. prolifera was present. This work gives initial insight on the physiological performance of C. prolifera in Ria Formosa.Ervas marinhas são plantas angiospérmicas adaptadas ao ambiente marinho que formam pradarias extensivas em zonas costeiras a nível mundial, com exceção dos polos. Estas pradarias formam um habitat complexo e diverso, apresentando uma alta produtividade e prestando serviços ecossistémicos importantes, como o sequestro e armazenamento de carbono, reciclagem de nutrientes e proteção costeira. No entanto, apesar da sua importância, são um dos habitats marinhos mais ameaçados. A maior causa de perda de pradarias de ervas marinhas é a atividade antropogénica. Dragagens, eutrofização, descargas de nutrientes e desenvolvimento costeiro são exemplos de atividades que diminuem a qualidade da água e afetam diretamente as pradarias. Além disso, ocorrem também perdas naturais das pradarias, por exemplo, pela competição com outros macrófitos, como é o caso das algas que podem ocupar o mesmo espaço e utilizar os mesmos recursos. A sua colonização pode afetar não só o ecossistema, mas também a abundancia de espécies endémicas e a sua diversidade. Diferentes macroalgas verdes já provaram ter um elevado potencial invasor, entre as quais se destingem espécies do género Caulerpa. Este género inclui algumas das algas mais invasoras conhecidas atualmente. Caulerpa taxifolia e Caulerpa racemosa são alguns exemplos de algas que invadiram o Mar Mediterrâneo e que afetaram negativamente várias pradarias de ervas marinhas. Além de competirem por recursos como nutrientes e luz, competem também pelo mesmo substrato, previamente ocupado com ervas marinhas, não permitindo que elas recuperem. Fisiologicamente, ervas marinhas e algas, mais especificamente do género Caulerpa, são limitadas pela luz. As primeiras apresentam uma maior necessidade de luz, mas isso não impede que várias espécies tenham capacidade de sobreviver quando a irradiância é baixa. Vários mecanismos de defesa, que variam de espécie para espécie, determinam a sua resiliência a estas condições. Por outro lado, a exposição a luz excessiva também pode ser prejudicial para as plantas, nomeadamente induzindo stress foto-oxidativo. Para defesa contra o excesso de luz (fotoproteção), as plantas possuem pigmentos secundários, os carotenóides, capazes de transformar o sistema de captura de luz num sistema de dissipação de energia excessiva na forma de calor. O género Caulerpa não só apresenta uma elevada plasticidade a nível morfológico mas também ao nível dos seus pigmentos. Tal como as ervas, as algas possuem carotenóides capazes de dissipar energia excessiva. Além disso, a sua capacidade para tolerar altas intensidades de luz depende dos nutrientes disponíveis, que podem obter não só da coluna de água, mas também do sedimento, havendo assim competição entre as ervas marinhas e as algas em ambos os meios. Com o aparecimento da Caulerpa prolifera em zonas menos profundas da Ria Formosa, onde ocorrem três das quatro espécies de ervas marinhas a nível Europeu, surge a necessidade de perceber o seu funcionamento fisiológico comparativamente com as ervas e avaliar o potencial para interações fisiológicas. Para tal, analisou-se a performance circadiana de Zostera marina, Cymodocea nodosa e C. prolifera ao longo de um ciclo de 48 horas numa sistema seminatural. Foram medidos parâmetros relacionados com a fluorescência da clorofila a, medindo a eficiência quântica e recolhendo amostras para analise bioquímica. Numa outra experiência, para estudar possíveis consequências da interação entre ervas e algas, Z. marina e C. prolifera foram recolhidas no campo e plantadas em tanques, quer individualmente quer em conjunto, em cinco replicados, recebendo sempre a mesma intensidade de luz com um fotoperíodo de treze horas, durante quatro semanas. Após as quatro semanas, foi avaliada a resposta da fotossíntese à luz de curvas em ambas as espécies e recolhidas amostras para posterior analise bioquímica. Foram analisados os conteúdos em açúcares solúveis e amido, proteína solúvel, compostos adenilados e pigmentos fotossintéticos nas três espécies. Os açúcares e amido foram analisados pelo método fenol-sulfúrico e as proteínas solúveis pelo método de Bradford. Os compostos adenilados foram analisados por cromatografia liquida de alta eficiência (HPLC). Os pigmentos fotossintéticos foram analisados primeiro por espectrofotometria para identificar concentrações de clorofila, complementando com cromatografia (HPLC) para a identificação dos carotenoides. As ervas apresentaram níveis de eficiência quântica real e potencial e dissipação de energia sob a forma de calor mais elevadas comparativamente com a alga, e índices de desepoxidaçao dos pigmentos do ciclo das xantofilas mais elevados, mostrando estar mais protegidas contra intensidades de luz mais elevadas. C. prolifera, pelo contrário, apresentou uma resposta típica de espécies adaptadas a baixas intensidades de luz, com razões de clorofila a/b mais baixas do que as ervas e índices de desepoxidação do ciclo das xantofilas muito baixos. Apresentou ainda taxas fotossintéticas ligeiramente mais baixas, uma taxa de respiração mais elevada e uma maior resposta foto-inibitória a intensidade de luz mais alta, comparado a Z. marina. O conteúdo de açúcar solúvel da alga foi significativamente mais baixo do que o das ervas, enquanto que as suas reservas de amido foram muito mais elevadas, revelando um regime de utilização de hidratos de carbono bastante distinto. A interação de Z. marina com C. prolifera não mostrou ter influência nas capacidades fotossintéticas e teores de pigmentos fotossintéticos de ambas as espécies. No entanto, verificou-se um esgotamento das reservas de amido nos rizomas de Z. marina. Uma vez que não foram observadas alterações nas taxas de respiração, colocamos a hipótese que os hidratos de carbono foram utlizadas como base para síntese de moléculas com funções alelopáticas. Desta forma, a alga parece induzir um efeito fisiológico nesta erva marinha, ao nível da utilização dos hidratos de carbono. Esta é a primeira vez que é reportado um efeito fisiológico deste tipo. Apesar de apresentar adaptações para ambientes de baixa intensidade luminosa, o avanço observado de C. prolifera em zonas menos profundas da Ria Formosa pode estar relacionado com a sua plasticidade morfológica e a sua resistência a intensidades mais elevadas desde que os nutrientes não são o fator limitante. Este estudo apresenta uma introdução às diferenças fotofisiológicas entre C. prolifera e as ervas marinhas nativas da Ria Formosa, mas deverá ser completado eventualmente com uma análise sazonal e de crescimento, para uma compreensão mais detalhada de como a C. prolifera interage com as ervas marinhas, tanto a nível ecológico como também a nível bioquímico

A new seismicity catalogue of the eastern Alps using the temporary Swath-D network

We present a new, consistently processed seismicity catalogue for the eastern and southern Alps based on the temporary dense Swath-D monitoring network. The final catalogue contains 6053 earthquakes for the time period 2017–2019 and has a magnitude of completeness of −1.0 ML. The smallest detected and located events have a magnitude of −1.7 ML. Aimed at the low to moderate seismicity in the study region, we have developed a multi-stage, mostly automatic workflow that combines a priori information from local catalogues and waveform-based event detection, subsequent efficient GPU-based (GPU: graphics processing unit) event search by template matching, P and S arrival time pick refinement, and location in a regional 3-D velocity model. The resulting seismicity distribution generally confirms the previously identified main seismically active domains but provides increased resolution of the fault activity at depth. In particular, the high number of small events additionally detected by the template search contributes to a denser catalogue and provides an important basis for future geological and tectonic studies in this complex part of the Alpine orogen

GPS Tracking System

V práci je popsán základní princip a vlastnosti globálního pozičního systému GPS. Je zde přiblížena problematika určování polohy, rychlosti a nadmořské výšky. Tyto poznatky jsou dále použity pro návrh zařízení, které komunikuje s běžně vyráběným GPS přijímačem a z něj získané informace zpracovává a ukládá do paměti pro pozdější vyhodnoceníThe keystone and properties of Global Position System (GPS) are described in this thesis. The thesis explains questions of position, speed and elevation above sea-level determining. These findings are used for the prototype device design which communicates with commonly used GPS receiver. The obtained data from the GPS receiver are processed and stored by the device for later evaluation.

Web sites concept

Práce se zabývá kompletním návrhem internetových stránek. Obsahem práce je jak prvotní analýza všech funkcí stránek, návrh grafického designu, tak i samotná technická realizace pomocí webových programovacích jazyků. Práce se zabývá i prvotním spuštění stránek, odstranění chyb, následným spravováním aplikace a aktualizacemi jak z technického hlediska, tak i obsahového.My project put mind to complete web sites concept. Content of project consist in first analyse of all functions, webdesign concept and technical implementation through the use of web programming languages, too. Another part of project is description of the first web initialization, elimination of mistakes, follow-up administration and updating programmed code or text.

Company Internet Sites and E-commerce

Práce se zabývá kompletním návrhem internetových stránek a elektronického obchodu. Obsahem práce je jak prvotní analýza všech funkcí stránek, návrh systému internetového obchodu, návrh grafického designu, tak i samotná technická realizace pomocí webových programovacích jazyků a databáze. Práce se zabývá i prvotním spuštěním stránek, odstraněním chyb, následným spravováním aplikace a aktualizacemi jak z technického hlediska, tak i obsahového. Obsažena je i ekonomická stránka, dopady na firmu, obsluha obchodu a zhodnocení provozu konkrétního projektu tvorby elektronického obchodu.Thesis deal with complete proposition of internet sites and e-commerce. Thesis includes first analyse of all web functions, scheme of e-commerce, scheme of graphic layout, e-commerce implementation by the help of web programming languages and databases. Part of thesis is first initiation of internet sites, debugging, administration systém, technical and content updating. There is also economical evaluation, influence on the company, service of e-commerce and off-set evaluation whole system.

The effects of prior education and engagement on success in engineering studies: do women and men differ?

Background In Dutch engineering education, female students outperform male students. Using an interactionalist framework, this study explores factors that contribute to this gender-based difference. Purpose This study aims to answer two questions: Do female and male students differ in background characteristics, engagement factors, and academic success? Are differences in the relationships among background characteristics, engagement factors, and academic success gender-specific? Design/method Data on male and female engineering undergraduate students from five Dutch universities were subjected to linear structural modeling to compare potential gender differences in the relationships among the focal variables. Two structural models were considered. Results Female students spent more time on independent study, reported more social inte- gration, completed more credits, and were more likely to stay in engineering than were male students. Academic integration and intention to persist were important for comple- tion of credits for both genders. Social integration was only important for men’s academic success. Females seemed to benefit less from good preparation through active learning during secondary education, and the effect of a high grade point average on math was neg- ative for females but positive for males. Conclusions Interactionalist concepts can explain academic success, but the relationships among concepts vary by gender. Males’ intentions to persist in engineering are an outcome of engagement processes during the first year, whereas females’ intentions to persist in engineering are manifest at the start of the first year

Cerebral arteriovenous malformations : usability of Spetzler-Martin and Spetzler-Ponce scales in qualification to endovascular embolisation and neurosurgical procedure

Purpose: Arteriovenous malformations (AVMs) are connected with cerebral haemorrhage, seizures, increased intracranial pressure, headaches, mass effect, and ischaemia symptoms. Selection of the best treatment method or even deciding if intervention is required can be difficult. Material and methods: The study included 50 patients who were diagnosed with cerebral AVMs and treated in our Centre between 2008 and 2014. A total of 111 procedures were performed, including 94 endovascular embolisations and 17 neurosurgical procedures. Medical records and imaging data were reviewed for all patients. All AVMs were measured and assessed, allowing classification in Spetzler-Martin and Spetzler-Ponce scales. Results: Complete or partial treatment was observed in 88.24% of neurosurgical procedures and in 84.00% of embolisations. Early complication rate was 21.28% for embolisation and 17.65% for neurosurgical procedures, while Glasgow Outcome Scale was 4.89 (σ = 0.38) and 5.0 (σ = 0.00), respectively. According to the Spetzler-Martin scale, cerebral haemorrhages occurred more frequently in grade 1, but no statistical significance was observed. In Spetzler- Ponce class B lower grades in Glasgow Coma Scale (GCS) were noticed (p = 0.02). Lower GCS scores were also correlated with deep location of AVM and with eloquence of adjacent brain. Patients with Spetzler-Martin grade 1 were more frequently qualified for neurosurgical procedures than other patients. Conclusions: Treating AVMs requires coordination of a multidisciplinary team. Both endovascular embolisation and neurosurgical procedure should be considered as a part of multimodal, frequently multistage treatment. Spetzler-Martin and Spetzler-Ponce scales have an influence on haemorrhage frequency and patients’ clinical condition and should be taken into consideration in selecting the treatment method

Global Positioning System Signal Emulator

Práce se zabývá principem satelitní navigace. Přibližuje problematiku určení polohy a nadmořské výšky na povrchu Země. Obsahuje rozbor navigačních zpráv a způsob zpracování navigačních signálů v GPS přijímačích. Dále jsou popsány návrh a realizace emulátoru navigačního signálu systému GPS v prostředí Matlab. Ten slouží ke generování kompletních navigačních zpráv, které je možné vysílat pomocí univerzálního softwarového rádia. V poslední části práce je proveden rozbor těchto signálů zachycených pomocí druhého softwarového rádia.Thesis is adressed to the principals of a satellite navigation. It is focused on a determination of a longitude, latitude and altitude of a single point on the surface of the Earth. It contains analysis of navigation messages and a manner of processing of navigation signals in GPS receivers. Realization of an emulator of the navigation signal of GPS system in Matlab is also described. The purpose of this emulator is a generation of navigation messages, which could be transmitted by universal software radio. The last part of thesis contains the analysis of these signals, which were captured by second software radio.

Een algemene benadering werkt niet:disciplinaire verschillen als verklaring van studievoortgang in het hoger beroepsonderwijs

In dit artikel combineren we concepten uit Tinto’s interactionele theorie over de oorzaken van studie-uitval en Becher’s theorie over wetenschapsgebieden ter verklaring van studievoortgang van eerstejaarsstudenten in het hoger beroepsonderwijs. De data zijn verzameld via een online-vragenlijst, afgenomen bij ruim 8.000 eerstejaarsstudenten van vijf ho- gescholen (respons 30%). Eerst is voor een selectie van de totale responsgroep (N = 1.876) een lineair structureel model getoetst waarin voorbereiding, ervaringen en studiegedrag in het eerste jaar studievoortgang verklaren. Vervolgens zijn modellen voor de sectoren Economie (N = 920), Techniek (N = 313), Gezondheidszorg (N = 284), en Gedrag & Maatschappij (N = 359) ontwikkeld en vergeleken. De ‘intentie om te blijven’, gemeten na drie maanden in het eerste jaar, blijkt in alle sectoren de belangrijkste voorspeller van studievoortgang. Goede voorbereiding op actief leren en academische kennis en vaardigheden in de vooropleiding beïnvloeden tevredenheid over aansluiting en studievoortgang. De factoren geslacht, vooropleiding, voorbereiding op actief leren in de vooropleiding, contacturen en zelfstudie laten per sector belangrijke verschillen zien in effecten op eerstejaarservaringen en studievoortgang. De resultaten impliceren dat een generieke benadering voor het verklaren van studievoortgang, rendementsanalyses, kwaliteitszorg en verbetering van de aansluiting onvoldoende is. Meer aandacht is gewenst voor verschillen tussen sectoren