Cytochemical localization of acid phosphatase in Stigeoclonium tenue (Chaetophorales, Chlorophyceae)

Nonspecific acid phosphatases are a group of enzymes whose activity increases the availability of exogenous and endogenous orthophosphate either through extra- or intracellular hydrolysis of phosphate compounds. Our study demonstrates the activity of acid phosphatases in the filamentous freshwater alga Stigeoclonium tenue. These enzymes were detected following a cerium-based method in which cerium was used as an orthophosphate-capture reagent. In thalli from S. tenue from the natural environment, acid phosphatases were found in the longitudinal cell wall, plasmalemma, and vacuole. In thalli from Bold’s Basal Medium culture, these enzymes were found mainly in the plasmalemma; they were scarce in the cell wall. In the thalli grown in phosphate-enriched culture medium, enzymes were found only in the plasmalemma. The low availability of orthophosphate in the medium seems to induce the transport of these enzymes to the cell wall. Its abundance, on the contrary, seems to attenuate this response without affecting the localization of acid phosphatases in the plasmalemma.Fil: Michetti, Karina Mariel. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ficología y Micología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leonardi, Patricia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Caceres, Eduardo Jorge. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ficología y Micología; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin

Biología reproductiva del peral (Pyrus communis L.) : compatibilidad, capacidad partenocárpica y polinización cruzada de los cultivares Abate Fetel y Williams

La producción de peras en Uruguay oscila año a año, sin alcanzar una estabilidad productiva adecuada. El peral (Pyrus communis L.) presenta autoincompatibilidad e intercompatibilidad, con alta capacidad partenocárpica reportada en el cultivar ‘Williams’. Las causas de la variabilidad en la producción son numerosas, siendo la variación en la tasa de polinización un factor determinante. El objetivo de este trabajo fue caracterizar la biología reproductiva, y evaluar la compatibilidad genética de los cultivares ‘Abate Fetel’ y ‘Williams’ con otras fuentes de polen, para las condiciones agroclimáticas uruguayas. Las flores de cada cultivar se seleccionaron en el estado fenológico de botón cerrado (F1 según Fleckinger, 1965). En ‘Abate Fetel’, 60 flores se embolsaron con una malla anti insectos (autopolinizadas), 60 fueron emasculadas y embolsadas (sin polinizar) y otras 120 se emascularon, se polinizaron manualmente (60 flores con cada polinizante) y luego se embolsaron (polinización cruzada). Para las polinizaciones cruzadas dirigidas se utilizaron los cultivares 'Williams precoz’ y ‘BP1’ utilizado a nivel productivo como portainjerto. En ‘Williams’ el cultivar polinizante fue el cultivar ‘Packham's Triumph’. Simultáneamente, se tomaron muestras de flores de cada tratamiento a los 2, 5 y 7 días después de la aplicación del tratamiento, para estudiar la germinación de los granos de polen y el crecimiento del tubo polínico. En el campo, el cuajado se evaluó quincenalmente a partir de la caída de los pétalos; en cosecha se determinó el número y tamaño de los frutos y la presencia de semillas. Los resultados permitieron confirmar que ‘Abate Fetel’ presenta autoincompatibilidad de tipo gametofítico, deteniendo el crecimiento de su tubo polínico en la primera mitad del estilo. Para el mismo cultivar, los tratamientos de flores autopolinizadas y sin polinizar dieron como resultado un 0 % de cuajado evaluado 30 días después de la aplicación del tratamiento. La polinización manual (polinización cruzada) alcanzó el 58 % (‘BP1’) y el 76 % (‘Williams precoz’) de cuajado. En ‘Williams’ los tratamientos de autopolinización y emasculado sin polinización, resultaron en un 13 % y 14 % de cuajado respectivamente, mientras que las flores con polinización cruzada alcanzaron el 40 %

Reef Carbonate Budgets & Symbiodiniaceae Diversity in the Arabian Gulf, Western Indian Ocean & Central Indo-Pacific

Coral reefs are the result of long-term net calcium carbonate (CaCO3) accretion and the balance between carbonate production and erosion, referred to as the carbonate budget. Coral calcification is influenced by environmental conditions (e.g. temperature, depth and ocean acidification) and depends on a symbiotic partnership between the coral and its dinoflagellate algae in the family Symbiodiniaceae. When a coral encounters stress, the symbiosis breaks down resulting in coral bleaching which impacts reef calcification. To effectively monitor reef health, it is essential to determine the current status of reef environments and whether reef frameworks are actively accreting CaCO3 or being eroded away. This study aims to determine reef accretional health in three bioregions: Bahrain (located in the hottest sea on the planet – the Arabian Gulf), the Seychelles (with an environment susceptible to regular El Nino disturbances - Western Indian Ocean) and Indonesia (located within the epicenter of marine biodiversity, the Coral Triangle - Central Indo-Pacific). In addition, genetic diversity of selected coral symbionts is investigated. In light of predicted warming trends, which present a threat to the structural integrity of reefs worldwide, questions arise whether reefs will be able to maintain a positive carbonate budgetary state to keep pace with future sea level rise and maintain the stability of island-nations such as Bahrain, the Seychelles and Indonesia. This thesis explores the past and present trajectories of reefs within these bioregions whilst providing important insights for consideration to model future trajectories of these reefs

Unintended consequences of communicating rapid COVID-19 vaccine policy changes– a qualitative study of health policy communication in Ontario, Canada

Background The success of the COVID-19 vaccination roll-out depended on clear policy communication and guidance to promote and facilitate vaccine uptake. The rapidly evolving pandemic circumstances led to many vaccine policy amendments. The impact of changing policy on effective vaccine communication and its influence in terms of societal response to vaccine promotion are underexplored; this qualitative research addresses that gap within the extant literature. Methods Policy communicators and community leaders from urban and rural Ontario participated in semi-structured interviews (N = 29) to explore their experiences of COVID-19 vaccine policy communication. Thematic analysis was used to produce representative themes. Results Analysis showed rapidly changing policy was a barrier to smooth communication and COVID-19 vaccine roll-out. Continual amendments had unintended consequences, stimulating confusion, disrupting community outreach efforts and interrupting vaccine implementation. Policy changes were most disruptive to logistical planning and community engagement work, including community outreach, communicating eligibility criteria, and providing translated vaccine information to diverse communities. Conclusions Vaccine policy changes that allow for prioritized access can have the unintended consequence of limiting communities’ access to information that supports decision making. Rapidly evolving circumstances require a balance between adjusting policy and maintaining simple, consistent public health messages that can readily be translated into action. Information access is a factor in health inequality that needs addressing alongside access to vaccines

The impact of land-use intensification on pollination and seed-dispersal interactions in the wild cherry (Prunus avium L.)

Menschliche Aktivitäten beeinflussen beinahe alle Bereiche des Lebens auf der Erde (MEA 2005a; UNEP 2007). Die Zerstörung und Veränderung natürlicher Lebensräume sind als Hauptursache für den weltweiten Biodiversitätsverlust identifiziert (Harrison and Bruna 1999; Dale et al. 2000; Foley et al. 2005; MEA 2005a). Zusammen mit dem Klimawandel wird die Landnutzungsveränderung daher als einflussreichster Aspekt anthropogen verursachten globalen Wandels betrachtet (MEA 2005a). Landnutzungsveränderung schließt sowohl die Umwandlung natürlicher Habitate in Agrarland oder Siedlungen als auch die Landnutzungsintensivierung in bereits kultivierten Landschaften mit ein. Diese Veränderungen haben weitreichende Konsequenzen für die Artenvielfalt und resultieren häufig in dem Verlust von Arten mit zunehmender Intensität der Landnutzung (Scholes and Biggs 2005). Biodiversität und Ökosysteme stellen viele verschiedene Funktionen zur Verfügung, wie z. B. die Sauerstoffproduktion, die Reinigung von Wasser und die Bestäubung von Nutzpflanzen. Einige dieser Funktionen sind hilfreich, andere wichtig und wieder andere notwendig für das menschliche Wohlergehen (MEA 2005b; UNEP 2007). Mittlerweile sind Ökosystemfunktionen und die vielen Nutzen, die sie erbringen, zu einem zentralen Thema der interdisziplinären Forschung von Sozialwissenschaften und Naturwissenschaften geworden (Barkmann et al. 2008 und darin enthaltene Referenzen). Dadurch bedingt ist es zu einiger Verwirrung bezüglich der verwendeten Begriffe der "Ökosystemfunktion" (engl. "ecosystem function") und dem der "Ökosystemdienstleistung" (engl. "ecosystem service") gekommen (deGroot et al. 2002). Da der Fokus meiner Arbeit auf grundlegenden Funktionen von Ökosystemen liegt, verwende ich im Folgenden den Begriff der Ökosystemfunktion. Für viele Ökosystemfunktionen ist noch sehr unzureichend bekannt, wie diese von externen Störungen beeinflusst werden (Kremen and Ostfeld 2005; Balvanera et al. 2006). Ökosystemfunktionen werden selten von nur einer einzigen Art aufrechterhalten, sondern meist von einer ganzen Reihe unterschiedlicher taxonomischer Gruppen – alle mit ihren ganz eigenen Ansprüchen. Diese Arten, wie auch deren intra- und interspezifischen Interaktionen, können durchaus nterschiedlich auf die gleiche Störungsquelle oder Störungsintensität reagieren. Dies kann Vorhersagen zum Verhalten von Ökosystemfunktionen extrem erschweren. ..

X-Ray Interrogated Implantable Chemical and Strain Sensors for Monitoring Implant Associated Infections And Fracture Healing

Bone fracture healing includes complex and sequence of dynamic events to restore the integrity and biomechanical properties of the bone. While most of the fractures heal without any problem, healing is sometimes compromised. Two significant fracture healing complications are orthopedic implant-associated infections and non-unions/delayed union. These can be interrelated causes as well. Implant-associated infection can cause implant loosening, and as a result, it can delay the fracture healing process. Herein, we describe two different types of sensors that can be used in monitoring biochemical and biomechanical processes of fracture healing using X-rays. We developed a XELCI (X-ray Excited Luminescence Chemical Imaging) based biochemical sensor for monitoring implant-associated infections by decreasing pH due to acidic products of bacterial metabolism. High spatial resolution pH mapping of the intramedullary canal through bone and tissue was carried out with the XELCI imaging technique developed in our lab. Pre-pilot rabbit studies were carried out to monitor the pH variations in the intramedullary canal of the rabbit tibia by creating two infected rabbit models compared to a sterile control rabbit. We observed a pH drop in the intramedullary canal while using the pH-sensitive hydrogel-coated intramedullary rod. Moreover, to monitor stiffness and biomechanical properties of the healing bone during fracture healing, we developed a biomechanical sensor with hydromechanical amplification read via plain radiography. The sensor was mounted on Sawbones tibia models (fractured and allograft repaired) and human cadaveric tibia and tested under cyclic loading. The sensor displayed reversible and repeatable behavior with a slope of 0.096 mm/kg and fluid level noise of 50 to 80 micrometer (equivalent to 5-10 N). While both these sensors will address the two major issues in fracture healing providing useful insight, they can be improved with future modifications. The proposed intramedullary rod design with wells can be machined in stainless steel to be a more robust sensor. Moreover, as we carried out this study as a pre-pilot study, we can extend it into a full study also combining it with antibiotic treatment in animal models. Chromoionophore III can be investigated as a potential dye for monitoring pH as well as other analytes of interest at the fracture site. The fluidic sensor can be improved by miniaturizing the sensor components and designing it to attach to the side of the orthopedic implant plate where there’s more room for sensor accommodation. In addition, the sensor can be applied in other types of fractures and implant plates as the senor was only studied on tibial implant plates

Ecology and farming of milkfish

This book is a reader-friendly illustrated account of the life history of milkfish (Chanos chanos) in nature and in aquaculture. It describes the different farming systems and status of the milkfish industry, and recommends means to ensure sustainability

Using Macroeconomic Indicators to Enact an Ambitious Circular Economy

The circular economy has the potential to promote systemic change towards a sustainable future. However, the dominance of technical and market-oriented considerations has placed the circular economy as part of an eco-modernist agenda, which retains growth in gross domestic product as the overarching priority. In this context, we analyse 12 existing macroeconomic indicators, developed and implemented by governments and international organisations, and determine if they could enact alternative notions of circularity. Specifically, we focus on the performative role that indicators can play in both defining and surmounting such reductionist views, thus helping us to address the world we want to create. We find that many of these indicators are agents of the status quo, but that some could disrupt the omnipotence of GDP thereby getting the macroeconomic conditions right for a more ambitious understanding of the circular economy

The Third International Symposium on Tilapia in Aquaculture

Tilapias, because of the low cost and relative ease of their production, are a potential food fish staple for many people ini tropical countries and a globally traded commodity. This volume of symposium proceedings shows a strong interest in production systems research and a dawning interest in socioeconomic research. Both of these fields of research are expected to receive much greater attention in the future as the economic and market importance of tilapia increases and as we seek to understand better the distribution of benefits of the different production technologies.Tilapia culture Tilapia, Oreochromis, Sarotherodon