Genetically manipulated phages with improved pH resistance for oral administration in veterinary medicine

Orally administered phages to control zoonotic pathogens face important challenges, mainly related to the hostile conditions found in the gastrointestinal tract (GIT). These include temperature, salinity and primarily pH, which is exceptionally low in certain compartments. Phage survival under these conditions can be jeopardized and undermine treatment. Strategies like encapsulation have been attempted with relative success, but are typically complex and require several optimization steps. Here we report a simple and efficient alternative, consisting in the genetic engineering of phages to display lipids on their surfaces. Escherichia coli phage T7 was used as a model and the E. coli PhoE signal peptide was genetically fused to its major capsid protein (10A), enabling phospholipid attachment to the phage capsid. The presence of phospholipids on the mutant phages was confirmed by High Performance Thin Layer Chromatography, Dynamic Light Scattering and phospholipase assays. The stability of phages was analysed in simulated GIT conditions, demonstrating improved stability of the mutant phages with survival rates 102107 pfu.mL1 higher than wild-type phages. Our work demonstrates that phage engineering can be a good strategy to improve phage tolerance to GIT conditions, having promising application for oral administration in veterinary medicine.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and under the scope of the Project PTDC/BBB-BSS/6471/2014 (POCI-01-0145-FEDER-016678). Franklin L. Nobrega and Ana Rita Costa acknowledge FCT for grants SFRH/BD/86462/2012 and SFRH/BPD/94648/2013, respectively. Melvin F. Siliakus acknowledges funding from the Biobased Ecologically Balanced Sustainable Industrial Chemistry (BE-BASIC) foundation. Electron microscopy work was performed at the Wageningen Electron Microscopy Centre (WEMC) of Wageningen University

The processing and impact of dissolved riverine nitrogen in the Arctic Ocean

© The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Estuaries and Coasts 35 (2012): 401-415, doi:10.1007/s12237-011-9417-3.Although the Arctic Ocean is the most riverine-influenced of all of the world’s oceans, the importance of terrigenous nutrients in this environment is poorly understood. This study couples estimates of circumpolar riverine nutrient fluxes from the PARTNERS (Pan-Arctic River Transport of Nutrients, Organic Matter, and Suspended Sediments) Project with a regionally configured version of the MIT general circulation model to develop estimates of the distribution and availability of dissolved riverine N in the Arctic Ocean, assess its importance for primary production, and compare these estimates to potential bacterial production fueled by riverine C. Because riverine dissolved organic nitrogen is remineralized slowly, riverine N is available for uptake well into the open ocean. Despite this, we estimate that even when recycling is considered, riverine N may support 0.5–1.5 Tmol C year−1 of primary production, a small proportion of total Arctic Ocean photosynthesis. Rapid uptake of dissolved inorganic nitrogen coupled with relatively high rates of dissolved organic nitrogen regeneration in N-limited nearshore regions, however, leads to potential localized rates of riverine-supported photosynthesis that represent a substantial proportion of nearshore production.Funding for this work was provided through NSFOPP- 0229302 and NSF-OPP-0732985.Support to SET was additionally provided by an NSERC Postdoctoral Fellowship

Efeito da realização simultânea de tarefas cognitivas e motoras no desempenho funcional de idosos da comunidade

O objetivo deste estudo foi avaliar o efeito de seis diferentes tarefas duplas no desempenho funcional de idosos da comunidade. Em 35 idosos com idade média de 69,6±7,1 anos foi aplicado o teste de levantar e caminhar cronometrado (TLCC, Timed up and go ou TUG) simples (TLCCS) e associado a duas tarefas motoras - carregar um copo com água (TLCCM1) e transferir moedas de um bolso para o outro (TLCCM2) - e duas cognitivas, repetir uma frase (TLCCC1) e falar os dias da semana em ordem inversa (TLCCC2), sendo aferidos os acertos e erros nessas tarefas. Houve piora significativa da média do tempo em segundos no TLCC nas tarefas duplas, independente da tarefa, e correlação significativa, de moderada (r=0,676) a quase perfeita (r=0,953), entre os tempos de cada tipo de TLCC. O número de moedas transferidas no TLCCM2 e o número de dias na semana dito em ordem inversa no TLCCC2 apresentaram correlação com o tempo gasto para realizar todas as outras tarefas. Essas duas tarefas foram as que mais afetaram o tempo do TLCC (pThe purpose was to assess the effect of six different dual tasks in community dwelling elderly. Thirty-five volunteers (aged 69.6±7.1 years) were submitted to the Timed Up and Go test (TUG) and to further five tasks wherein TUG was associated to two motor tasks - carrying a glass of water (TUGM1) and transferring coins from one pocket to another (TUGM2); to two cognitive tasks - repeating a sentence (TUGC1) and saying weekdays backwards (TUGC2); and to a motor-cognitive task, of carrying a glass of water while repeating a sentence (TUGMC). Time spent, failure and success in each task were counted. Results showed a significant decrease in average time (in seconds) spent in TUG when associated with all tasks; and a significant correlation from moderate (r=0.676) to almost perfect (r=0.953) between the times of each association with TUG. The number of transferred coins in TUGM2 and the number of days of the week correctly said in TUGC2 showed a correlation with the time spent in all the other tasks. These two tasks most affected the time spent to accomplish TUG (p<0.001). Hence, dwelling community elderly showed a decrease in performance at all dual tasks associated to TUG. The worst functional performances were transferring coins from one pocket to another and saying weekdays backwards, showing that task complexity, rather than task nature, had greater impact on the time spent to perform TUG

Recent advances and future directions in soils and sediments research

In 2010, the Journal of Soils and Sediments (JSS) reached a milestone: its 10th anniversary. This prompted us to think about where the academic community has come in its understanding of the behaviour of soils and sediments within landscapes. The rapid growth of the journal and the number of papers published in it, and other related journals, suggests, probably correctly, that there is much interest in the topics of soils and sediments. In the January 2011 editorial (Xu and Owens 2011), we presented an overview of some of the main developments in the past 10 years and provided some future directions of JSS for 2011 and beyond. In that editorial we indicated that a more comprehensive editorial would be published in the journal on the recent advances and future directions of soils and sediments research. The following sections are presented to fulfill this commitment and start a dialogue with the journal subject editors, authors and readers in these important areas of soils and sediments research. The dawn of the next decade of JSS is a good time to reflect on progress to-date and, more importantly, to consider where research needs to go in the years ahead; a time of rapid environment change, a time of rapid population growth, and a time when society is increasingly looking to science to provide the understanding (and solutions) to the problems that we face.No Full Tex