Refining the ecological role of stingrays in coral reef ecosystems

Coral reefs are some of the most diverse and complex ecosystems in the world. They are known for their ability to support a high diversity of marine life. Unfortunately, coral reefs and their associated marine life are under intense anthropogenic pressures; climate change, habitat loss and overfishing are some of the main threats. These pressures also have negative effects on stingrays inhabiting coral reef areas. Management and conservation of stingrays is currently hindered by a lack of knowledge on essential aspects of their ecology. Therefore, this thesis aimed to refine the roles juvenile stingrays play in coral reef habitats and determine the importance of coral reef habitat to stingray populations in a nursery area in the Great Barrier Reef. To do so, this thesis addressed five specific aims: (1) review the current knowledge on batoid nursery areas; (2) identify movement patterns and determine habitat use of juvenile cowtail stingrays Pastinachus ater; (3) evaluate the accuracy of towed-float GPS tags to assess movement patterns and habitat use of stingrays; (4) identify diel movement patterns and habitat use of juvenile mangrove whiprays Urogymnus granulatus; and (5) investigate the relative trophic relationships of four juvenile elasmobranch species within a communal nursery area, with an emphasis on stingrays. Nursery areas are crucial for many elasmobranch species, providing advantages such as increased access to prey and reduced mortality. To date, batoid nurseries have been poorly studied in comparison with shark nurseries. The current decline of batoid populations worldwide, resulting in serious extinction threats, highlights the importance of better understanding these critical habitats. This dissertation presented a synthesis of the available knowledge on batoid nurseries and suggests the use of a combination of well-established criteria to standardize batoid nursery definition. Two telemetry approaches were used to examine movement patterns and habitat use of two stingray species commonly found in coral reef habitats: cowtail stingrays Pastinachus ater and mangrove whiprays Urogymnus granulatus. First, active acoustic telemetry was used to investigate cowtail stingray movements. Active acoustic telemetry provided fine-scale results, but had some limitations (e.g. potential human disturbance and difficulties in performing night tracks). Therefore, a new method was developed – towed-float GPS telemetry –- to investigate mangrove whipray activity patterns and habitat use. Lastly, stable isotope analysis was used to define the contribution of potential carbon sources in the food web and the trophic position and relationship of four juvenile elasmobranch species (mangrove whipray, cowtail stingray, blacktip reef shark Carcharhinus melanopterus and giant shovelnose ray Glaucostegus typus). Active acoustic telemetry results generated a total of 14 active tracks of cowtail stingrays ranging from 4.91 to 9 hours. Cowtail stingrays moved at an average speed of 2.44 m.min⁻¹ + 0.87 SE, with minimum distances travelled ranging from 546 to 1446 meters. Tracking data showed that juvenile cowtail stingrays move in response to tidal cycles, moving faster and with straighter pathways during incoming and outgoing tides, compared to low and high tides. Juvenile cowtail stingrays also showed a strong affinity to sand flat areas and mangrove edge areas, but were infrequently detected in mangrove root habitats. These areas provide food resources and potential refuges for juvenile rays to avoid potential predators. Reef crest habitats were identified as secondary refuge for juveniles during the lowest tides. Towed-float GPS tags were tested on juvenile stingrays with active tracking performed simultaneously for comparison. Individuals travelled 1332.15 ± 269.58 m SE across Pioneer Bay at an average speed of 6.87 m.min⁻¹ and average tracking time of 3.7 hours. Stationary tests demonstrated that the quality of the data obtained by towed-float GPS tags could not be matched by active, acoustic or ARGOS telemetry – on average reaching 99% of successful location recording and <15 meters accuracy. Location Error varied significantly based on the number of satellites detected, with error decreasing as satellite number increased. Towed-float GPS telemetry showed juvenile mangrove whiprays travelled distances from 394 to 2189 meters during tracks, moving at a mean rate of movement of 4.51 m.min⁻¹ ± 3.1 SE with track durations ranging from 1.5 to 9.0 hours. Juvenile mangrove whipray movements were strongly influenced by tidal cycles and rate of movement was significantly different between day and night. Individuals moved faster and chose more direct paths during the outgoing and incoming tide, and were significantly faster during the day than at night. Juvenile mangrove whiprays showed preference for mangrove root habitats during high tides. These areas are thought to reduce juvenile stingray predation risk. Stable isotope analysis showed all juvenile elasmobranchs in Pioneer Bay are at a trophic level of ~4. Isotopic niche size of blacktip reef sharks was smaller than both stingrays, and cowtail stingrays showed the largest niche size. Results showed strong evidence of niche partitioning between mangrove whiprays and cowtail stingrays with differences in feeding strategy. Nearshore pelagic and benthic prey items (e.g. crabs, annelid worms and small baitfishes) contributed most to juvenile elasmobranch diets, while mangrove or offshore prey and carbon sources appear to not have significant input. Results of telemetry and stable isotope analysis revealed juvenile stingrays were fully dependent on the Pioneer Bay system. This dissertation confirms juvenile stingrays play important roles as mesopredators and energetic links within the Pioneer Bay nursery area. By looking at fine scale movements and trophic relationships, this PhD provides important information to better understanding juvenile stingray's ecology, but also to support management and conservation policies

Does venture capital really foster innovation?

Using panel data of 17 European Union countries, we find robust empirical support for a positive impact of venture capital on innovation. After controlling for the potential endogenous relationship between venture capital and innovation, the results indicate that venture capital fosters innovation but mainly on a later stage.CEMPRE; QREN; FEDER; Fundação para a Ciência e a Tecnologia (FCT

The effect of entrepreneurial origin on firms' performance: the case of Portuguese academic spinoffs

We investigate the role of entrepreneurial origin on firms' performance by comparing academic spinoff firms with their non-academic counterparts. Academic spinoffs grow through resources accumulation and internationalization; yet they do not translate these advantages into productivity gains. The access to upstream complementary resources appears to play a chief role in explaining the academic spinoffs' superior performance. Academic spinoffs are contributing to economic development by creating new jobs, but their relevance as a source of sustained economic value is limited so far.This work was carried out within the funding with COMPETE reference POCI-01-0145-FEDER-006683 (UID/ECO/03182/2013), with the FCT/MEC's (Fundacao para a Ciencia e Tecnologia) financial support through national funding and by the ERDF through the operational program on "Competitiveness and Internalization-COMPETE 2020 under the PT2020 Partnership Agreement.

Amphiphile Adsorption on Rigid Polyelectrolytes

A theory is presented which quantitatively accounts for the cooperative adsorption of cationic surfactants to anionic polyelectrolytes. For high salt concentration we find that the critical adsorption concentration (CAC) is a bilinear function of the polyion monomer and salt concentrations, with the coefficients dependent only on the type of surfactant used. The results presented in the paper might be useful for designing more efficient gene delivery systems

Saberes de professores alfabetizadores: princípios e domínios para autoavaliação docente

The article deals with the relationship between teaching knowledge and self-assessment processes in a shared way. Part-se of the qualitative study, developed from narrative interviews and dialogic encounters (Bakhtin, 2010; Bolzan, 2019; Freitas, 2009;Vigotsky, 2021) which will allow us to identify the reference pedagogical practices of teachers working in the literacy cycle, well How to recognize the principles and the pedagogical domains prioritized by the teachers to energize their work. We consider thatthe knowledge derived from teaching experience makes it possible to build an effective repertoire of solutions acquired during a long practice of the trade (Gauthier et al., 2006; Tardif, 2007), characterizing practices of references of teachers, thus we can demonstrate pedagogical principles and domains of abragência These dimensions will be discussed and shared, revealing drives for teacher self-assessment (Fernandes, 2008, Morales, 2014) encouraging reflection on ongoing pedagogical practices, favoringteacher transformation and reworking.El artículo discute la relación entre los saberes docentes y los procesos de autoevaluación de forma compartida. Se parte de un estudio cualitativo, desarrollado a partir de entrevistas narrativas y encuentros dialógicos (Bakhtin, 2010; Bolzan, 2019;Freitas, 2009; Vigotsky, 2021), que permitieron identificar las prácticas pedagógicas de referencia de docentes que actúan en el ciclo de alfabetización, así como la forma de reconocer los principios y dominios pedagógicos priorizados por los docentes cuando agilizan su trabajo. Se considera que los saberes provenientes de la experiencia docente posibilitan la construcción de un repertorio efectivo de soluciones adquiridas durante una larga práctica del oficio (Gauthier et al., 2006; Tardif, 2007), caracterizando las prácticas de referencia de los docentes, de las cuales se pueden evidenciar principios pedagógicos y dominios de cobertura. Tales dimensiones, cuando discutidas y compartidas, resultan estar impulsando la autoevaluación de los docentes (Fernandes, 2008, Morales, 2014), favoreciendo la reflexión sobre las prácticas pedagógicas en curso, favoreciendo la transformación y la reelaboración docente.O artigo aborda a relação entre os saberes docentes e os processos de autoavaliação de forma compartilhada. Parte-se do estudo qualitativo, desenvolvido a partir de entrevistas narrativas e encontros dialógicos (Bakhtin, 2010; Bolzan, 2019; Freitas, 2009; Vigotsky, 2021), os quais permitiram identificar as práticas pedagógicas de referência de professoras atuantes no ciclo de alfabetização, bem como reconhecer os princípios e os domínios pedagógicos priorizados pelas professoras ao dinamizarem seu trabalho. Considera-se que os saberes advindos da experiência docente possibilitam a construção de um repertório eficaz de soluções adquiridas durante uma longa prática do ofício (Gauthier et al., 2006; Tardif, 2007), caracterizando práticas de referências das docentes, nas quais se podem evidenciar princípios pedagógicos e domínios de abrangência. Tais dimensões, ao serem discutidas e compartilhadas, revelam-se impulsionadoras da autoavaliação docente (Fernandes, 2008; Morales, 2014), fomentando a reflexão das práticas pedagógicas em curso, favorecendo a transformação e a reelaboração docente

Homophobia, Fundamentalism, and Canadian Tolerance: Enabling Gay Games III in Vancouver

Gay Games III were held in Vancouver in August 1990. This paper analyzes the effects of three different moments of homophobic backlash faced by organizers of that event. While quiet institutional homophobia might have been tolerated, public representations of blatant homophobia could be mobilized by the organizers of Gay Games IIII to their advantage. The effects of a hateful campaign paradoxically functioned as an interesting condition of possibility for Gay Games' credibility. I then suggest that the limitations of these liberal strategies were shown up by the fractures within local lesbian and gay communities, demonstrating the weaknesses of accepting tolerance as a limit to the possible.Les troisièmes Jeux Gais ont eu lieu à Vancouver en août 1990. Ce document analyse les effets de trois moments différents du ressac homophobe auquel ont fait face les organisateurs de cet événement. Même si l’homophobie institutionnelle discrète aurait pu être tolérée, les organisateurs de ces jeux ont pu tourner à leur avantage les représentations publiques de l’homophobie flagrante. Les effets d’une campagne de haine ont paradoxalement été favorables à la possibilité de tenir des Jeux Gais crédibles. Je crois donc que les fractures observées dans les communautés lesbienne et gaie locales ont fait ressortir les limites de ces stratégies libérales en démontrant les failles de l’acceptation de la tolérance comme limite du possible

Industry- and firm-specific factors of innovation novelty

This paper investigates the underlying factors that might shape the firm’s choices with respect to degrees of innovation novelty.Using a sample of 2983 firms observed under the Portuguese Community Innovation Survey, we assess the relative relevance of a set of firm- and industry-specific factors in explaining firms’ choices about incremental or radical innovation. The results indicate that both the firm’s idiosyncratic historical factors giving rise to heterogeneous R&D capabilities and the industry context have power to shape the firm’s innovation choices, even though firm-specific factors appear to be more powerful. The estimated impacts on firm’s innovation novelty are, nonetheless, significantly moderated by the type of firm and industry.COMPETE, QREN, FEDER, FC

Firms’ innovation across regions : an exploratory study

NIPE WP 12/2013This paper investigates the geographical distribution and concentration of firms’ innovation persistence and innovation type - product and process - based upon three waves of the Community Innovation Survey data covering the period 1998-2006. The main findings are: (i) both innovation persistence and innovation type are asymmetrically distributed across Portuguese regions; (ii) the degree of correlation between geographical location and innovative output varies with the innovation type; and (iii); the correlation between geographical unit and innovation increases when the spatial unit of analysis is narrower. Overall, results indicate that firm’s choice of geographical location have a long-lasting effect, engendering no equal probabilities of being persistently innovator.COMPETE; QREN; FEDER; Fundação para a Ciência e a Tecnologia (FCT

Portuguese regional innovation systems efficiency in the European Union context

Current evidence on European regional innovation systems efficiency shows some conflicting results. Whereas some studies find support to a core-periphery distribution of efficiency, others find that lagging regions can be as well or even more efficient than rich regions in using their resources. This paper contributes to this debatable topic by providing additional evidence on the main determinants of the region's innovation efficiency and on efficiency differentials across EU regional innovation systems. Using data from 206 European regions and applying a stochastic production frontier methodology, our results corroborate the importance of interactions among regional agents on the region's efficiency score. More importantly, the distribution of efficiency scores across regional innovation systems does not entirely confirm the core-periphery divide among European regions. Instead, the mode of doing innovation appears to be a crucial explanatory factor of innovation efficiency at regional level. In the case of Portuguese regional innovation systems, they perform slightly below the average of their EU counterparts, except Lisbon's, and appear to be constrained by their mode of doing innovation.This work was carried out within the funding with COMPETE reference POCI-01-0145-FEDER-006683 (UID/ECO/03182/2013), with the FCT/MEC's (Fundacao para a Ciencia e Tecnologia) financial support through national funding and by the ERDF through the operational program on "Competitiveness and Internalization-COMPETE 2020 under the PT2020 Partnership Agreement.