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Contents: 1. Introduction 2. Global field investigations on microplastic pollution in mussels 2.1 Selected species and geographic coverage 2.2 Characteristics of microplastic pollution 2.3 Methodological challenges 3. Laboratory exposures of microplastics in mussels 3.1 Uptake, accumulation and clearance of microplastics 3.2 Toxic effects of microplastics 3.3 Optimization of laboratory exposures 4. Scope of mussels as global bioindicators of microplastic 4.1 Advantages of utilizing mussel 4.2 Current regional and national proposals 4.3 Future developments

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When used as therapy for hematopoietic malignancies, allogeneic BM transplantation (BMT) relies on the graftversus-leukemia (GVL) effect to eradicate residual tumor cells through immunologic mechanisms. However, graft-versus-host disease (GVHD), which is initiated by alloreactive donor T cells that recognize mismatched major and/or minor histocompatibility antigens and cause severe damage to hematopoietic and epithelial tissues, is a potentially lethal complication of allogeneic BMT. To enhance the therapeutic potential of BMT, we sought to find therapeutic targets that could inhibit GVHD while preserving GVL and immune responses to infectious agents. We show here that T cell responses triggered in mice by either Listeria monocytogenes or administration of antigen and adjuvant were relatively well preserved in the absence of PKC isoform θ (PKCθ), a key regulator of TCR signaling. In contrast, PKCθ was required for alloreactivity and GVHD induction. Furthermore, absence of PKCθ raised the threshold for T cell activation, which selectively affected alloresponses. Most importantly, PKCθ-deficient T cells retained the ability to respond to virus infection and to induce GVL effect after BMT. These findings suggest PKCθ is a potentially unique therapeutic target required for GVHD induction but not for GVL or protective responses to infectious agents.

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Site selection is a key factor in any aquaculture operation, because it affects both success and sustainability. It can, moreover, solve conflicts between different activities, making rational use of the land. This study was conducted to identify suitable sites for development of Nile tilapia (Oreochromis niloticus) farming in Sitakunda Upazila (subdistrict), Bangladesh, using GIS-based multi-criteria evaluation of water and soil quality, topography, infrastructure and socio-economic factors. ASTER image and eighteen thematic layers were analyzed using ENVI and ArcView software to identify the suitable areas for tilapia farm development. A constraint layer was used to exclude areas from suitability maps that cannot be allowed to implement tilapia farming. A series of GIS models were developed to identify and prioritize the most suitable areas for tilapia farming. The output of the model clearly indicates the location and extent of tilapia farming areas on different suitability scales, i.e. most suitable (7,744 ha), moderately suitable (2,479 ha), and not suitable (838 ha). Model outputs were assessed against field verification data, and were consistent. Because existing aquaculture covers only 1,540 ha of land in the study area, the potential for expanding tilapia farms should take into consideration socio-political and environmental issues. The results are encouraging in terms of tilapia culture development and suggest that grassland-agriculture areas could be used for sustainable development of tilapia farming to diversify the economic activities of rural communities.

Oyster reefs have the potential as eco-engineers to improve coastal protection. A field experiment was undertaken to assess the benefit of oyster breakwater reefs to mitigate shoreline erosion in a monsoon-dominated subtropical system. Three breakwater reefs with recruited oysters were deployed on an eroding intertidal mudflat at Kutubdia Island, the southeast Bangladesh coast. Data were collected on wave dissipation by the reef structures, changes in shoreline profile, erosion-accretion patterns, and lateral saltmarsh movement and related growth. This was done over four seasons, including the rainy monsoon period. The observed wave heights in the study area ranged 0.1–0.5 m. The reefs were able to dissipate wave energy and act as breakwaters for tidal water levels between 0.5–1.0 m. Waves were totally blocked by the vertical relief of the reefs at water levels <0.5 m. On the lee side of the reefs, there was accretion of 29 cm clayey sediments with erosion reduction of 54% as compared to control sites. The changes caused by the deployed reefs also facilitated seaward expansion of the salt marsh. This study showed that breakwater oyster reefs can reduce erosion, trap suspended sediment, and support seaward saltmarsh expansion demonstrating the potential as a nature-based solution for protecting the subtropical coastlines.

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