Impacts And Dispersal Of Invasive Bivalves, Dreissena And Corbicula Spp., On Stream Benthic Communities

Asian clams (Corbicula spp.), zebra and quagga mussels (Dreisenna spp.) have invaded and spread throughout North American surface waters. Corbicula and Dreisenna species bio foul aquatic systems, occupy benthic substrates and degrade environments through shell deposition. I explored how Dreissena and Corbicula invasions affect benthic fish and macroinvertebrate communities, and examine how their impacts differ between urban and rural systems, and temperate and tropical climates. Macroinvertebrate and fish communities were evaluated at sites with increasing shell densities in the Rouge, and Huron rivers (MI, USA) using the United States Environmental Protection Agency’s Rapid Bioassessment Protocols (RBP). Urban and rural macroinvertebrate communities were compared by installing in situ colonization racks with Dreissena shell/cobble treatments of 100/0%, 75/25%, 25/75%, and 0/100% in urban and rural river reaches of the Rouge, Clinton and Huron rivers. I evaluated the impacts of Corbicula on macroinvertebrate communities in rivers in four climate regions including Michigan, Ohio, Georgia and Puerto Rico. All benthic community data was evaluated using water quality, diversity and habitat metrics. In the RBP assessment of the Rouge and Huron rivers, I found that that relative abundance of sensitive macroinvertebrates decreases as Dreissena shell densities increase in both rivers. Benthic fish were not significantly impacted as shell densities increased in either river. In rural reaches of the Huron River, fewer sensitive macroinvertebrate families colonized high density shell treatments when compared to cobble; conversely, macroinvertebrate community diversity was elevated in high shell densities when compared to low densities in urban reaches of all three rivers. The impact of increasing Corbicula population densities differed as macroinvertebrate diversity and evenness increased with population density in the temperate, Michigan climate and decreased as clam densities increased in tropical Puerto Rico. These findings indicate that bivalve invasions can have deleterious impacts on sensitive macroinvertebrates in urban and rural settings but can provide habitat for urban communities. Although temperate macroinvertebrates favor dense bivalve invasions in northern climates, declines in diversity and evenness in the south may foreshadow responses as surface water temperatures increase. This data could help management groups anticipate the impacts of invasive bivalves on native faunal communities

Influential Article Review- External Investment and Economic Development in Ghana’s Agriculture Sector

This paper examines Investment and Agriculture. We present insights from a highly influential paper. Here are the highlights from this paper: The study seeks to establish the relationship between foreign direct investment to Ghana’s agriculture sector and economic growth with secondary data mainly sourced from the World Development Indicator. The techniques employed to analyse the data include descriptive statistics, unit root test, Granger causality test and error correction model (ECM). The study accepted a neutrality hypothesis between foreign direct investment to the Ghanaian agricultural sector and its covariates; trade openness, capital and government expenditure. The study also revealed a positive and significant relationship between economic growth and foreign direct investment flow to the agricultural sector and volume of trade respectively. However, government expenditure exhibits a negative but significant relationship with economic growth. The study contributes to economic development literature from an important but neglected research context with regards to agricultural development via foreign direct investment to support job creation and overall economic development with particular reference to Ghana. Thus, the study recommends that policy should focus on flexible trade policies to attract more foreign direct investment (FDI) inflows to Ghana’s agricultural sector to accelerate growth across the board. For our overseas readers, we then present the insights from this paper in Spanish, French, Portuguese, and German

Where People Meet the Muck: An Integrated Assessment of Beach Muck and Public Perception at the Bay City State Recreation Area, Saginaw Bay, Lake Huron

In several regions of the Great Lakes, including Saginaw Bay, the proliferation of muck, decaying organics largely from aquatic plants such as Cladophora, has washed ashore, and is blamed for negatively affecting water quality and economic losses in the region. The current view is that excess nutrient loading into the system is a leading cause of this type of organic debris, though changes in food web dynamics may also be a contributing factor. Through an Integrated Assessment (IA) framework, we summarized the current state of knowledge on the causes and consequences of muck conditions at the Bay City State Recreation Area (BCSRA), including the socio-economic impacts of muck at the park and on the Saginaw Bay Region. Through this framework we identify potential management scenarios for addressing beach fouling at the BCSRA. Through a robust stakeholder engagement process, the IA team implemented a suite of models and surveys to understand public perception of muck-related issues and identified a series of feasible short and long-term management actions that could help alleviate and better manage the impacts of muck. Results indicate that even drastic reductions in external phosphorus loads will not eliminate Cladophora growth in the bay. Beach muck is likely a historical part of the system, and nutrient reduction programs may not prevent muck from fouling Saginaw Bay beaches. We identify a sustainable park management practice maybe reallocating resources previously designated for cleaning efforts to achieve bare, sandy beaches and promoting alternative ecological activities and attractions such as bird watching, kayaking, and nature walks in the park’s coastal marshes

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Spirocyclic β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitors: From hit to lowering of cerebrospinal fluid (CSF) amyloid β in a higher species

A hallmark of Alzheimer\u27s disease is the brain deposition of amyloid beta (Aβ), a peptide of 36-43 amino acids that is likely a primary driver of neurodegeneration. Aβ is produced by the sequential cleavage of APP by BACE1 and γ-secretase; therefore, inhibition of BACE1 represents an attractive therapeutic target to slow or prevent Alzheimer\u27s disease. Herein we describe BACE1 inhibitors with limited molecular flexibility and molecular weight that decrease CSF Aβ in vivo, despite efflux. Starting with spirocycle 1a, we explore structure-activity relationships of core changes, P3 moieties, and Asp binding functional groups in order to optimize BACE1 affinity, cathepsin D selectivity, and blood-brain barrier (BBB) penetration. Using wild type guinea pig and rat, we demonstrate a PK/PD relationship between free drug concentrations in the brain and CSF Aβ lowering. Optimization of brain exposure led to the discovery of (R)-50 which reduced CSF Aβ in rodents and in monkey. © 2013 American Chemical Society