scholarly journals Gut Bacteria Mediate Nutrient Availability in Drosophila Diets

2020 ◽  
Vol 87 (1) ◽  
Author(s):  
Danielle N. A. Lesperance ◽  
Nichole A. Broderick
Keyword(s):  
Life History ◽  
Diet Composition ◽  
Life History Traits ◽  
Gut Bacteria ◽  
Dependent Manner ◽  
Artificial Diets ◽  
Content Type ◽  
Nutritional Physiology ◽  
Wide Range ◽  
Depth Analysis

ABSTRACT Drosophila melanogaster gut microbes play important roles in host nutritional physiology. However, these associations are often indirect, and studies typically are in the context of specialized nutritional conditions, making it difficult to discern how microbiome-mediated impacts translate to physiologically relevant conditions, in the laboratory or nature. In this study, we quantified changes in dietary nutrients due to D. melanogaster gut bacteria on three artificial diets and a natural diet of grapes. We show that under all four diet conditions, bacteria altered the protein, carbohydrates, and moisture of the food substrate. An in-depth analysis of one diet revealed that bacteria also increased the levels of tryptophan, an essential amino acid encountered scarcely in nature. These nutrient changes result in an increased protein-to-carbohydrate (P:C) ratio in all diets, which we hypothesized to be a significant determinant of microbiome-mediated host nutritional physiology. To test this, we compared life history traits of axenic flies reared on the three artificial diets with increased P:C ratios or continuous bacterial inoculation. We found that while on some diets, an environment of nutritional plenitude had impacts on life history, it did not fully explain all microbiome-associated phenotypes. This suggests that other factors, such as micronutrients and feeding behavior, likely also contribute to life history traits in a diet-dependent manner. Thus, while some bacterial impacts on nutrition occur across diets, others are dictated by unique dietary environments, highlighting the importance of diet-microbiome interactions in D. melanogaster nutritional physiology. IMPORTANCE Both in the laboratory and in nature, D. melanogaster-associated microbes serve as nutritional effectors, either through the production of metabolites or as direct sources of protein biomass. The relationship between the microbiome and the resulting host nutritional physiology is significantly impacted by diet composition, yet studies involving D. melanogaster are performed using a wide range of artificial diets, making it difficult to discern which aspects of host-microbe interactions may be universal or diet dependent. In this study, we utilized three standard D. melanogaster diets and a natural grape diet to form a comprehensive understanding of the quantifiable nutritional changes mediated by the host microbial community. We then altered these artificial diets based on the observed microbe-mediated changes to demonstrate their potential to influence host physiology, allowing us to identify nutritional factors whose effects were either universal for the three artificial diets or dependent on host diet composition.

scholarly journals Gut bacteria mediate nutrient availability in Drosophila diets

2020 ◽  
Author(s):  
Danielle N.A. Lesperance ◽  
Nichole A. Broderick
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Gut Bacteria ◽  
Dependent Manner ◽  
Natural Diet ◽  
Nutritional Conditions ◽  
Nutritional Physiology ◽  
Depth Analysis ◽  
Nutrient Changes ◽  
Food Substrate

SummaryDrosophila melanogaster gut microbes play important roles in host nutritional physiology. However, these associations are often indirect and studies typically are in the context of specialized nutritional conditions, making it difficult to discern how microbiome-mediated impacts translate to physiologically relevant conditions, in the laboratory or nature. Here, we show that on three artificial diets and a natural diet of grapes, D. melanogaster gut bacteria alter protein, carbohydrates, and moisture of the food substrate. In depth analysis on one diet revealed bacteria also increase tryptophan levels. We investigate how nutrient changes impact life history and find that, while alterations to dietary protein and carbohydrates are arguably the most significant consequence of bacterial association, other factors, such as micronutrients, likely contribute to life history traits in a diet-dependent manner. Our work demonstrates that while some bacterial impacts on nutrition occur across experimental diets, others are dictated by unique dietary environments.

Tata Wiron: branding galvanized wires

2015 ◽  
Vol 5 (7) ◽  
pp. 1-8
Author(s):  
Vijay Pundalik Bhangale ◽  
Maithili Prashant Dhuri
Keyword(s):  
Learning Outcomes ◽  
Market Segmentation ◽  
Value Chain ◽  
Far East ◽  
Commodity Market ◽  
Content Type ◽  
Steel Wires ◽  
Wide Range ◽  
Major Player ◽  
Depth Analysis

Subject area Marketing. Study level/applicability MBA Marketing Class. Case overview The case describes the transition of a “Galvanized Wires Business of Tata Steel” into a unique identity, the'Tata Wiron' brand. It focuses on key stages in this journey, including “Understanding the Customers in Galvanized Wires Business”, “Value Chain”, “Challenges Faced”, “Need for Branding”, “Market Segmentation”, “Competition”, “Process of Branding”, “Differentiation”, “Distribution & Sales” and “Promotion”. Tata Steel Wires Business is a major player in the steel wire industry, servicing the discerning needs of its customers across global markets and the leading producer of steel wires in India. A wealth of experience and expertise in the wire industry coupled with latest technology incorporations has enabled Tata Steel Wires Division to constantly meet the most exacting specifications and requirements of its customers. It manufactures a wide range of wires catering to the needs of various industry segments, such as automobile, infrastructure, power and general engineering. The products are well established across the markets of Europe, the USA, Middle East Asia, Australasia, South Asia and Asia and the Far East. Expected learning outcomes The expected learning outcomes are as follows: understanding how in-depth analysis of the competition and value chain establishes the need for branding in a commodity market; understanding how consumer insights help in market segmentation and targeting; and building a brand in commodity market. Supplementary materials Teaching notes are available for educators only. Please contact your library to gain login details or email [email protected] to request teaching notes.

Systematic bibliometric analysis on Kaizen in scientific journals

2018 ◽  
Vol 30 (4) ◽  
pp. 356-370 ◽  
Author(s):  
José Álvarez-García ◽  
Amador Durán-Sánchez ◽  
María de la Cruz del Río-Rama
Keyword(s):  
Ad Hoc ◽  
Bibliometric Study ◽  
Scientific Journals ◽  
Content Type ◽  
Current State ◽  
Wide Range ◽  
Depth Analysis ◽  
State Of Research ◽  
Japanese Companies ◽  
Specific Search

Purpose Since Masaaki Imai coined the term Kaizen in the mid-1980s, it has been seen as a key element for the competitiveness of Japanese companies, and it is currently a widely discussed philosophy and is applied in a wide range of organizations throughout the world. The purpose of this paper is to serve as guidance for researchers who are developing their studies in the field of the Kaizen philosophy, in order to improve their knowledge on the most relevant articles, the most productive authors or the key scientific journals that make up this subject. Design/methodology/approach In order to fulfill the proposed objective, a descriptive bibliometric study was carried out with the analysis of citations from 138 articles included in the multidisciplinary database Scopus (Elsevier) until 2016. For the search of documents, a tracking strategy was chosen that allowed for the development of the ad hoc database required to analyze each of the basic variables of the bibliometric indicators. Findings The results obtained show a growing interest of the scientific community in its study in the last decade, as shown by the significant increase in citations received by articles, despite the reduction in the number of papers published in the last two years. Research limitations/implications The main limitations are derived from the choice of a specific database, as well as the specific search equation. Originality/value The study presents an in-depth analysis of the current state of research regarding the Kaizen philosophy through its bibliometric study, providing useful information for academics and professionals by providing a series of significant indicators to measure the bibliographic material.

A comparative perspective of knowledge management via social media: India and China

2015 ◽  
Vol 22 (2) ◽  
pp. 93-114 ◽  
Author(s):  
Michelle Liu ◽  
Pramila Rao
Keyword(s):  
Social Media ◽  
Knowledge Management ◽  
Management Practices ◽  
Current Knowledge ◽  
Global Market ◽  
Comparative Perspective ◽  
Content Type ◽  
Wide Range ◽  
Depth Analysis ◽  
India And China

Purpose – This research paper aims to showcase current knowledge management (KM) practices via social media that is being adopted by organizations in India and China. India and China are considered leading economies in today’s global market. Any understanding of management practices in these countries will help practitioners in doing businesses in these nations. Design/methodology/approach – This conceptual paper analyzes KM practices in India and China using an in-depth analysis of the extant literature to provide a comparative perspective of KM policies in these two economies. This paper has used a wide range of scholarly and non-scholarly databases from ABI Global Inform to Business Source Complete to Google Scholar among others. Findings – This research offers valuable insights into characteristic KM trends followed by Indian and Chinese firms. This paper also highlights different approaches adopted by these two cultures in managing their KM practices. The study also provides hypotheses that can be tested by potential scholars. This paper also offers theoretical models to understand this concept better. Practical implications – This paper also provides implications for practice by identifying guidelines for global managers. These frameworks might serve as preliminary parameters for practitioners planning to establish KM practices in India and China. Originality/value – This paper compares and contrasts KM practices in one of the two largest BRIC (Brazil, Russia, India and China) economies which have not been addressed in the literature before. It also combines two theoretical frameworks from different fields (information technology and human resource management) providing a richer viewpoint on the subject.

scholarly journals A novel experimental approach for studying life-history traits of phytophagous arthropods utilizing an artificial culture medium

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kamila Karpicka-Ignatowska ◽  
Alicja Laska ◽  
Lechosław Kuczyński ◽  
Brian G. Rector ◽  
Mariusz Lewandowski ◽  
...  
Keyword(s):  
Life History ◽  
Host Plant ◽  
Life History Traits ◽  
Culture Medium ◽  
Interspecific Interactions ◽  
Suitable Condition ◽  
Mite Species ◽  
Artificial Culture ◽  
Wide Range ◽  
Artificial Culture Medium

AbstractExperimental approaches to studying life-history traits in minute herbivorous arthropods are hampered by the need to work with detached host plant material and the difficulty of maintaining that material in a suitable condition to support the animal throughout the duration of the test. In order to address this shortcoming, we developed a customizable agar-based medium modified from an established plant cell-culture medium to nourish detached leaves laid atop it while also preventing arthropods from escaping the experimental arena. The artificial culture medium was tested with two herbivorous mite species: the wheat curl mite (Aceria tosichella; Eriophyidae) and two-spotted spider mite (Tetranychus urticae; Tetranychidae). The proposed approach was a major improvement over a standard protocol for prolonged studies of individual eriophyid mites and also provided some benefits for experiments with spider mites. Moreover, the described method can be easily modified according to the requirements of host plant species and applied to a wide range of microherbivore species. Such applications include investigations of life-history traits and other ecological and evolutionary questions, e.g. mating or competitive behaviours or interspecific interactions, assessing invasiveness potential and predicting possible outbreaks. The approach presented here should have a significant impact on the advancement of evolutionary and ecological research on microscopic herbivores.

Life history, demography, diet and habitat associations in the southwestern earless lizard, Cophosaurus texanus scitulus from northern and southern limits of its geographical range

2007 ◽  
Vol 28 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Fred Punzo
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Diet Composition ◽  
Life History Traits ◽  
Geographic Range ◽  
Habitat Associations ◽  
Generalist Predators ◽  
Reproductive Condition ◽  
Age Classes ◽  
Adult Age

AbstractI studied life history traits, demography, diet composition and habitat associations in the southwestern earless lizard, Cophosaurus texanus scitulus. Individuals from various age classes were sampled from populations at the northern (FCM) and southern (CAS) boundaries of its geographic range (FCM, foothills of Chinati Mts., Texas, USA; CAS, Castonos, Coahuila, Mexico). Males had higher growth rates as compared to females between the juvenile-to-yearling stages at both sites. Significant differences were also found for yearlings, and between yearling-to-adult stages. Growth rates decreased as a function of increasing age and were lowest in adults, and highest during the juvenile-to-yearling and yearling age classes. Earliest date on which a female was found to contain oviductal eggs was 19 May and 10 June, for the CAS and FCM sites, respectively. No females with oviductal eggs were found between 01 March and mid-May. Most females in reproductive condition had a SVL of 53-61 mm, and 57-64 mm, at the CAS and FCM sites, respectively, indicating that most females attain maturity at an age of 10-11 months. Clutch sizes were significantly smaller for females from the FCM site. Sex ratio was significantly biased toward females Survivorship was highest between yearling and adult age classes. Most lizards were found in areas with creosote and mesquite. These lizards are generalist predators that feed on a wide variety of arthropods.

scholarly journals Ecological Characteristics of Ventenata dubia in the Intermountain Pacific Northwest

2015 ◽  
Vol 8 (1) ◽  
pp. 57-71 ◽  
Author(s):  
John M. Wallace ◽  
Pamela L. S. Pavek ◽  
Timothy S. Prather
Keyword(s):  
Life History ◽  
Soil Moisture ◽  
Pacific Northwest ◽  
Seed Bank ◽  
Life History Traits ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Integrated Weed Management ◽  
Habitat Types ◽  
Wide Range

AbstractVentenata dubia is an exotic winter annual grass that has invaded Conservation Reserve Program (CRP) lands, improved pastures, intensively managed hay fields, and rangelands within the Intermountain Pacific Northwest (PNW). Currently, producers are attempting to develop V. dubia management strategies with little knowledge of its life history traits. We conducted several studies to characterize V. dubia life history patterns. Preliminary germination trials were completed to describe primary and secondary dormancy characteristics. Field studies were conducted to evaluate (1) seed bank persistence patterns, (2) seedling emergence patterns under V. dubia litter, and (3) seedling emergence and phenological development patterns within timothy hay, CRP, and rangeland habitats. Preliminary germination trials suggest that the after-ripening period required for loss of dormancy does not exceed 30 d and that dormancy breakdown peaks at approximately 90 d, after which germination occurs over a wide range of temperatures (9 to 29 C). A small fraction (< 1%) of the seed bank remained germinable up to 3 yr after burial at 2 cm depth in a grassland habitat. Seedling emergence and survival was significantly greater under high V. dubia litter layers (100% cover) compared with bare surface during the drier study year because of higher soil moisture levels maintained under litter. Across habitat types, mean seedling emergence (50% of total) occurred between 33 and 94 growing degree days (GDD) after soil moisture rose above the permanent wilting point in the fall. Seedling emergence periodicity varied among habitat types in relation to spring seedling emergence, ranging from 0 to 13% of total emergence per year. Phenological development differed across sites and years by up to several hundred GDDs but was closely aligned to Julian days. This collection of studies improves our understanding of V. dubia life history traits and will aid integrated weed management strategies in the Intermountain PNW.

scholarly journals Exploring conflicts between stakeholders in tourism industry. Citizen attitude toward peer-to-peer accommodation platforms

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
José María Martín Martín ◽  
Juan F. Prados-Castillo ◽  
Mónica de Castro-Pardo ◽  
Juan De Dios Jimenez Aguilera
Keyword(s):  
Rural Areas ◽  
Disease Transmission ◽  
Exploratory Study ◽  
Peer To Peer ◽  
Tourism Industry ◽  
Content Type ◽  
Wide Range ◽  
Depth Analysis ◽  
Negative Impacts ◽  
The One

Purpose The expansion of online platforms for renting tourist accommodations has given rise to a great deal of controversy in society. Likewise, the arrival of tourists in residential settings has led to a wide range of positive and negative impacts, resulting in conflicts between different stakeholders. The purpose of this paper is to analyze whether there is variation in the perception of the impacts associated with peer-to-peer accommodation platforms among different stakeholders? Additionally, it also seeks to investigate what kind of impacts generate the highest level of conflict among stakeholders? Design/methodology/approach Given the relative novelty of the problem, this paper proposes an exploratory study that sheds light on some of the main issues with the purpose of supporting further research in the future. The aim is to analyze which impacts are perceived as more positive or negative by each group and to create indexes of conflict for these groups regarding their perception of the impacts. This study is based on fieldwork carried out in April 2020, which consists of 600 online surveys of local residents in the city of Granada. This city, one of Spain’s main tourist spots, suffers the highest tourist pressure in the country. Findings The exploratory study suggests that the greatest consensus is generated in the assessment of economic impacts, either negative or positive. The greatest conflicts are related to the assessment of the effect of this activity on housing preservation. The group comprising accommodation owners of tourist flats is the one that shows a more dissenting opinion from the rest, confronting especially the group formed by citizens whose income depends on tourism. Originality/value There is a lack of studies on the perception of tourism impacts associated with online tourism rental platforms. This is the first study to analyze both, how the main stakeholders associated with this activity assess the different impacts derived from this form of tourist accommodation as a whole and the conflicts derived from such an assessment. An additional innovation is that the analysis investigates the potential fear of disease transmission caused by tourists. It would be interesting to continue this research by applying the same questionnaire in different environments, such as rural areas or societies with different structures from the one analyzed here. Likewise, future in-depth analysis of some of the conflicts is recommended so as to ascertain their origin.

scholarly journals Impact of global warming scenarios on life-history traits of Tetranychus evansi (Acari: Tetranychidae)

BMC Ecology ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Noureldin Abuelfadl Ghazy ◽  
Tetsuo Gotoh ◽  
Takeshi Suzuki
Keyword(s):  
Global Warming ◽  
Life History ◽  
Life History Traits ◽  
Distribution Range ◽  
Intrinsic Rate Of Increase ◽  
Biological Traits ◽  
Tetranychus Evansi ◽  
Future Global Warming ◽  
Wide Range ◽  
Summer Temperatures

Abstract Background The tomato red spider mite, Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae), is an agricultural pest of solanaceous crops. Although T. evansi is of South American subtropical origin, it has recently expanded its distribution range to many tropical and temperate areas around the world. Its potential distribution range in response to scenarios of global warming was recently modeled, confirming its current and possible future distributions. Here, we experimentally investigated the biological traits of T. evansi in the context of the current and future global warming (2100) scenarios. Using an environmental simulation system, we tested the life-history traits of T. evansi under current summer temperatures (as of June, July, and August 2016) and under expected temperature increases based on two IPCC scenarios: RCP2.6 (+ 1 °C) and RCP8.5 (+ 3.7 °C). The mites were introduced into each scenario on 1 June and their sequential progeny were used for testing in each following month. Results The mite could develop and reproduce under all scenarios. There was a decrease in the duration of lifespan and female fecundity at RCP8.5 during June and August, but this may be compensated for by the high intrinsic rate of increase, which implies faster population growth and shorter generation time. Conclusion Our study and other reports reveal the high adaptability of T. evansi to a wide range of summer temperatures; this may explain its current distribution. We anticipate that global warming will favor the spread of T. evansi and may further expand its distribution to a large area of the globe. These findings should be of ecological and practical relevance for designing prevention and control strategies.

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