scholarly journals Prochlorococcus Exudate Stimulates Heterotrophic Bacterial Competition with Rival Phytoplankton for Available Nitrogen

mBio ◽  
2022 ◽  
Author(s):  
Benjamin C. Calfee ◽  
Liz D. Glasgo ◽  
Erik R. Zinser

In nutrient-poor habitats, competition for limited resources is thought to select for organisms with an enhanced ability to scavenge nutrients and utilize them efficiently. Such adaptations characterize the cyanobacterium Prochlorococcus , the most abundant photosynthetic organism in the nutrient-limited open ocean.

2021 ◽  
Author(s):  
Benjamin C Calfee ◽  
Liz D Glasgo ◽  
Erik R Zinser

The marine cyanobacterium Prochlorococcus numerically dominates the phytoplankton community of the nutrient-limited open ocean, establishing itself as the most abundant photosynthetic organism on Earth. This ecological success has been attributed to lower cell quotas for limiting nutrients, superior resource acquisition, and other advantages associated with cell size reduction and genome streamlining. In this study we tested the prediction that Prochlorococcus outcompetes its rivals for scarce nutrients, and that this advantage leads to its numerical success in nutrient-limited waters. Strains of Prochlorococcus and its sister genus Synechococcus grew well in both mono- and co-culture when nutrients were replete. However, in nitrogen-limited medium Prochlorococcus outgrew Synechococcus, but only when heterotrophic bacteria were also present. In the nitrogen-limited medium, the heterotroph Alteromonas macleodii outcompeted Synechococcus for nitrogen, but only if stimulated by exudate released by Prochlorococcus, or if a proxy organic carbon source was provided. Analysis of a nitrate reductase mutant Alteromonas suggested that Alteromonas outcompetes Synechococcus for nitrate, during which co-cultured Prochlorococcus grows on ammonia or other available nitrogen species. We propose that Prochlorococcus can stimulate antagonism between heterotrophic bacteria and potential phytoplankton competitors through a metabolic cross-feeding interaction, and this stimulation could contribute to the numerical success of Prochlorococcus in the nutrient-limited regions of the ocean.


Author(s):  
Elena Dukhovny ◽  
E. Betsy Kelly

According to the 2010 U.S. Census, over 20% of Americans speak a language other than English in the home, with Spanish, Chinese, and French being the languages most commonly spoken, aside from English. However, few augmentative and alternative communication (AAC) systems offer multilingual support for individuals with limited functional speech. There has been much discussion in the AAC community about best practices in AAC system design and intervention strategies, but limited resources exist to help us provide robust, flexible systems for users who speak languages other than English. We must provide services that take into consideration the unique needs of culturally and linguistically diverse users of AAC and help them reach their full communication potential. This article outlines basic guidelines for best practices in AAC design and selection, and presents practical applications of these best practices to multilingual/multicultural clients.


Author(s):  
Harald Klingemann ◽  
Justyna Klingemann

Abstract. Introduction: While alcohol treatment predominantly focuses on abstinence, drug treatment objectives include a variety of outcomes related to consumption and quality of life. Consequently harm reduction programs tackling psychoactive substances are well documented and accepted by practitioners, whereas harm reduction programs tackling alcohol are under-researched and met with resistance. Method: The paper is mainly based on key-person interviews with eight program providers conducted in Switzerland in 2009 and up-dated in 2015, and the analysis of reports and mission statements to establish an inventory and description of drinking under control programs (DUCPs). A recent twin program in Amsterdam and Essen was included to exemplify conditions impeding their implementation. Firstly, a typology based on the type of alcohol management, the provided support and admission criteria is developed, complemented by a detailed description of their functioning in practice. Secondly, the case studies are analyzed in terms of factors promoting and impeding the implementation of DUCPs and efforts of legitimize them and assess their success. Results: Residential and non-residential DUCPs show high diversity and pursue individualized approaches as the detailed case descriptions exemplify. Different modalities of proactively providing and including alcohol consumption are conceptualized in a wider framework of program objectives, including among others, quality of life and harm reduction. Typically DUCPs represent an effort to achieve public or institutional order. Their implementation and success are contingent upon their location, media response, type of alcohol management and the response of other substance-oriented stake holders in the treatment system. The legitimization of DUCPs is hampered by the lack of evaluation studies. DUCPs rely mostly – also because of limited resources – on rudimentary self-evaluations and attribute little importance to data collection exercises. Conclusions: Challenges for participants are underestimated and standard evaluation methodologies tend to be incompatible with the rationale and operational objectives of DUCPs. Program-sensitive multimethod approaches enabled by sufficient financing for monitoring and accompanying research is needed to improve the practice-oriented implementation of DUCPs. Barriers for these programs include assumptions that ‘alcohol-assisted’ help abandons hope for recovery and community response to DUCPs as locally unwanted institutions (‘not in my backyard’) fuelled by stigmatization.


GeroPsych ◽  
2011 ◽  
Vol 24 (1) ◽  
pp. 5-18 ◽  
Author(s):  
Mirko Di Rosa ◽  
Christopher Kofahl ◽  
Kevin McKee ◽  
Barbara Bień ◽  
Giovanni Lamura ◽  
...  

This paper presents the EUROFAMCARE study findings, examining a typology of care situations for family carers of older people, and the interplay of carers with social and health services. Despite the complexity of family caregiving situations across Europe, our analyses determined the existence of seven “caregiving situations,” varying on a range of critical indicators. Our study also describes the availability and use of different support services for carers and care receivers, and carers’ preferences for the characteristics of support services. Our findings have relevance for policy initiatives in Europe, where limited resources need to be more equitably distributed and services should be targeted to caregiving situations reflecting the greatest need, and organized to reflect the preferences of family carers.


Author(s):  
Bryan Howell ◽  
Curt Anderson ◽  
Nile Hatch ◽  
Chia-Chi TENG; ◽  
Neal Bangerter ◽  
...  

Over that last few decades there has been a significant rise in interest for design-led entrepreneurship and innovation. This has brought about the need to expand on the principles and methods of human-centred design by incorporating knowledge from multiple disciplines, such as management, business, and entrepreneurship studies. This expansion aids designers, engineers, and marketing practitioners who strive to create innovative, meaningful and relevant services, business models and experiences. More often than not, ventures operate under very limited resources, and practitioners are often required to fulfil several roles. The concept of ‘multidisciplinary teams’ widely spread in this sphere often bears little resonance in these contexts. Designers possess valuable competencies that can have a significant impact on the venture, especially driving user and context-centred strategy and processes for the introduction, legitimization and scaling-up stages. However, engaging with these areas of practice requires skills and capacities that overlap traditional disciplinary roles. In doing so, the boundaries between design and engineering, branding and communications, cultural and behavioural insight, marketing and management strategy are blurred. As educators in design innovation, how do we explore, define and balance interdisciplinary relationships between design, engineering, management, business and entrepreneurship theories, methods, language and models of education? The purpose of the entrepreneurship in design education track is to discuss methods, models, case studies, research, insights and unexpected knowledge in benefits and limitations of design entrepreneurship education. In particular, the three papers presented in this track demonstrate different approaches to entrepreneurship and design education.


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