scholarly journals False biosignatures on Mars: anticipating ambiguity

2021 ◽  
pp. jgs2021-050
Author(s):  
Sean McMahon ◽  
Julie Cosmidis
Keyword(s):  
Solar System ◽  
Self Organization ◽  
Systematic Research ◽  
Small Subset ◽  
Content Type ◽  
Life On Mars ◽  
Detection Of Objects ◽  
Spatiotemporal Scales ◽  
Early Mars ◽  
Positive Results

It is often acknowledged that the search for life on Mars might produce false positive results, particularly via the detection of objects, patterns or substances that resemble the products of life in some way but are not biogenic. The success of major current and forthcoming rover missions now calls for significant efforts to mitigate this risk. Here, we review known processes that could have generated false biosignatures on early Mars. These examples are known largely from serendipitous discoveries rather than systematic research and remain poorly understood; they probably represent only a small subset of relevant phenomena. These phenomena tend to be driven by kinetic processes far from thermodynamic equilibrium, often in the presence of liquid water and organic matter, conditions similar to those that can actually give rise to, and support, life. We propose that strategies for assessing candidate biosignatures on Mars could be improved by new knowledge on the physics and chemistry of abiotic self-organization in geological systems. We conclude by calling for new interdisciplinary research to determine how false biosignatures may arise, focusing on geological materials, conditions and spatiotemporal scales relevant to the detection of life on Mars, as well as the early Earth and other planetary bodies.Thematic collection: This article is part of the Astrobiology: Perspectives from the Geology of Earth and the Solar System collection available at: https://www.lyellcollection.org/cc/astrobiology-perspectives-from-geology-of-earth-and-solar-system

scholarly journals Origin of Life on Mars: Suitability and Opportunities

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 539
Author(s):  
Benton C. Clark ◽  
Vera M. Kolb ◽  
Andrew Steele ◽  
Christopher H. House ◽  
Nina L. Lanza ◽  
...  
Keyword(s):  
Origin Of Life ◽  
Energy Sources ◽  
Early Earth ◽  
Sediment Samples ◽  
Life On Mars ◽  
Eventual Return ◽  
History Of ◽  
Early Mars ◽  
Chemical Conditions ◽  
Physical And Chemical

Although the habitability of early Mars is now well established, its suitability for conditions favorable to an independent origin of life (OoL) has been less certain. With continued exploration, evidence has mounted for a widespread diversity of physical and chemical conditions on Mars that mimic those variously hypothesized as settings in which life first arose on Earth. Mars has also provided water, energy sources, CHNOPS elements, critical catalytic transition metal elements, as well as B, Mg, Ca, Na and K, all of which are elements associated with life as we know it. With its highly favorable sulfur abundance and land/ocean ratio, early wet Mars remains a prime candidate for its own OoL, in many respects superior to Earth. The relatively well-preserved ancient surface of planet Mars helps inform the range of possible analogous conditions during the now-obliterated history of early Earth. Continued exploration of Mars also contributes to the understanding of the opportunities for settings enabling an OoL on exoplanets. Favoring geochemical sediment samples for eventual return to Earth will enhance assessments of the likelihood of a Martian OoL.

Responsible innovation and social innovation: toward an integrative research framework

2019 ◽  
Vol 46 (6) ◽  
pp. 742-755 ◽  
Author(s):  
Karsten Bolz ◽  
Anne de Bruin
Keyword(s):  
Social Innovation ◽  
Field Research ◽  
Responsible Innovation ◽  
Systematic Research ◽  
Content Type ◽  
Policy Practice ◽  
Integrative Framework ◽  
Integrative Research ◽  
Conceptual Paper ◽  
Innovation Study

PurposeResponsible innovation (RI) and social innovation (SI) are two fields of innovation study experiencing burgeoning policy, practice and research interest. Despite this rapid rise in popularity, the scholarly literature in these two related areas of innovation study remains quite separate, stymieing the growth of shared research insights. The purpose of this paper is to propose a pragmatic, process-based framework that lends itself to advancing systematic research in both fields while retaining their distinct identities.Design/methodology/approachThis conceptual paper outlines an analogy-inspired framework that builds on the logical thinking put forward by Philosopher Willard Van Orman Quine in 1962. It focusses on key processes that cross-cut both fields.FindingsReflexivity, collaboration and design are identified as three broad core processes that span both the RI and SI fields and form the basis of an integrative framework that highlights the scope for cross-field research pollination.Originality/valueThe literature that draws these two fields together is virtually non-existent. The paper uses analogy to facilitate awareness of the parallels between these two areas of innovation study. The integrative framework put forward in the paper is of value for advancing cumulative research in innovation fields of critical importance to the society.

Pathogenesis of Gram-Negative Bacteremia

2021 ◽  
Vol 34 (2) ◽  
Author(s):  
Caitlyn L. Holmes ◽  
Mark T. Anderson ◽  
Harry L. T. Mobley ◽  
Michael A. Bachman
Keyword(s):  
Immune Responses ◽  
Global Economy ◽  
Human Infection ◽  
Model Systems ◽  
Small Subset ◽  
Gram Negative ◽  
Content Type ◽  
Capsule Production ◽  
Gram Negative Bacteremia ◽  
Species Specific

SUMMARY Gram-negative bacteremia is a devastating public health threat, with high mortality in vulnerable populations and significant costs to the global economy. Concerningly, rates of both Gram-negative bacteremia and antimicrobial resistance in the causative species are increasing. Gram-negative bacteremia develops in three phases. First, bacteria invade or colonize initial sites of infection. Second, bacteria overcome host barriers, such as immune responses, and disseminate from initial body sites to the bloodstream. Third, bacteria adapt to survive in the blood and blood-filtering organs. To develop new therapies, it is critical to define species-specific and multispecies fitness factors required for bacteremia in model systems that are relevant to human infection. A small subset of species is responsible for the majority of Gram-negative bacteremia cases, including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. The few bacteremia fitness factors identified in these prominent Gram-negative species demonstrate shared and unique pathogenic mechanisms at each phase of bacteremia progression. Capsule production, adhesins, and metabolic flexibility are common mediators, whereas only some species utilize toxins. This review provides an overview of Gram-negative bacteremia, compares animal models for bacteremia, and discusses prevalent Gram-negative bacteremia species.

The effect of consumer emotions on outcome behaviors following service failure

2019 ◽  
Vol 33 (3) ◽  
pp. 285-302 ◽  
Author(s):  
L. Jean Harrison-Walker
Keyword(s):  
Service Failure ◽  
Negative Emotions ◽  
Behavioral Outcomes ◽  
Experience Sampling ◽  
Future Research ◽  
Systematic Research ◽  
Content Type ◽  
Complaining Behavior ◽  
Managerial Implications ◽  
Outcome Behaviors

Purpose The purpose of this paper is to explore the role of emotions that consumers experience following service failures and to assess the effects of each of these emotions on important behavioral outcomes. Design/methodology/approach This paper extends the work of Wetzer et al. (2007) and draws upon the existing literature to test a series of research hypotheses tying emotions to four important behavioral outcomes primarily using stepwise regression. Findings When a service failure occurs, customers experience any of a variety of negative emotions. The effect on behavioral outcomes depends on the specific emotion experienced by the consumer. The current research, which benefits by using retrospective experience sampling, finds that frustration is the predominant emotion experienced by customers following service failure, but that anger, regret and frustration affect behavioral outcomes. Uncertainty also plays a role. Research limitations/implications Future research should investigate the antecedents of propensity for emotions and predisposition toward industries, as well as the consequences of word-of-mouth (WOM) praise and WOM activity. Additionally, emotions could be examined by service stage. Several other moderators could be investigated, including severity, complaining behavior, repeat occurrence, service importance, remedies and forgiveness, product vs process failures, tenure, gender and age. Practical implications The current research emphasizes the importance of understanding which emotion is being experienced by a customer following service failure to identify the behavioral outcomes that will be most impacted. The specific managerial implications depend upon the specific emotional response experienced by the customer and are discussed separately for anger, regret and frustration. Service personnel must be trained to recognize and address specific customer emotions rather than to provide a canned or generalized response. Originality/value To date, there has been little, if any, systematic research into the effects of multiple discrete negative emotions on multiple desirable behavioral outcomes. The current study examines six discrete emotions. Predominant emotions are differentiated from emotional intensity. The behavioral outcomes of reconciliation and reduced share-of-wallet are added to the traditional outcomes of repatronage intentions and negative WOM. While existing research tends to rely on a scenario approach, this study uses the retrospective experience sampling method. The authors distinguish between mixed emotions and multiple emotions. The relative effects of disappointment and regret are examined for each of the four outcomes. Finally, importance-performance map analysis was applied to the findings to prioritize managerial attention. Numerous managerial and research implications are identified.

scholarly journals Factoring Origin of Life Hypotheses into the Search for Life in the Solar System and Beyond

Life ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 52 ◽  
Author(s):  
Alex Longo ◽  
Bruce Damer
Keyword(s):  
Solar System ◽  
Hydrothermal Vents ◽  
Hot Springs ◽  
Planetary Science ◽  
Icy Moons ◽  
Alternative Hypotheses ◽  
Biochemical Mechanisms ◽  
Early Mars ◽  
Life On Earth ◽  
Detection Strategies

Two widely-cited alternative hypotheses propose geological localities and biochemical mechanisms for life’s origins. The first states that chemical energy available in submarine hydrothermal vents supported the formation of organic compounds and initiated primitive metabolic pathways which became incorporated in the earliest cells; the second proposes that protocells self-assembled from exogenous and geothermally-delivered monomers in freshwater hot springs. These alternative hypotheses are relevant to the fossil record of early life on Earth, and can be factored into the search for life elsewhere in the Solar System. This review summarizes the evidence supporting and challenging these hypotheses, and considers their implications for the search for life on various habitable worlds. It will discuss the relative probability that life could have emerged in environments on early Mars, on the icy moons of Jupiter and Saturn, and also the degree to which prebiotic chemistry could have advanced on Titan. These environments will be compared to ancient and modern terrestrial analogs to assess their habitability and biopreservation potential. Origins of life approaches can guide the biosignature detection strategies of the next generation of planetary science missions, which could in turn advance one or both of the leading alternative abiogenesis hypotheses.

Conceptualizing trust with cultural perspective in international business operations

2017 ◽  
Vol 24 (4) ◽  
pp. 1099-1118 ◽  
Author(s):  
Mian Ajmal ◽  
Petri Helo ◽  
Rassel Kassem
Keyword(s):  
International Business ◽  
Business Environment ◽  
Trust Building ◽  
Systematic Research ◽  
Cultural Issues ◽  
Cultural Perspective ◽  
Global Business ◽  
Content Type ◽  
Business Environments ◽  
Building Process

Purpose The growing international landscape of business has underlined the significance of multiculturalism and the novel challenges it brings to business implementation. The purpose of this paper is to draw attention of the readers toward how trust can be conceptualized and how trust-building process is affected in global business environments where more and more projects and businesses come into operation. Design/methodology/approach This research employs intensive literature review to conceptualize trust and develop a model of culture effects for trust building in global business environment. However, this study is presently explanatory in nature because no empirical evidence is provided. Findings Culture is a significant factor in building trust among global project stakeholders for the reason that trust is vital for developing a well-functioning long-term business relationship. The study highlighted that cultural differences among project teams can cause conflict, misunderstanding, and poor project performance. Research limitations/implications Future empirical research should investigate various scenarios, types of projects, cultures, and countries. Cultural issues are pretty sensitive, which have immediate association with trust-building process among international project stakeholders. Diminutive systematic research has been done on the cultural effects for trust building in international business context. The probe of how culture affects trust building efforts in global business environments remains unrequited. Originality/value This study adds value by creating awareness in the research community for undertaking a detailed and comprehensive research on this topic, and because of its originality, it serves as a foundation for future studies.

scholarly journals Data-Driven Models Reveal Mutant Cell Behaviors Important for Myxobacterial Aggregation

mSystems ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Zhaoyang Zhang ◽  
Christopher R. Cotter ◽  
Zhe Lyu ◽  
Lawrence J. Shimkets ◽  
Oleg A. Igoshin
Keyword(s):  
Cell Tracking ◽  
Mutant Cell ◽  
Myxococcus Xanthus ◽  
Data Driven ◽  
Self Organization ◽  
Cell Behavior ◽  
Significant Heterogeneity ◽  
Wild Type ◽  
Content Type ◽  
Mutant Strains

ABSTRACT Single mutations frequently alter several aspects of cell behavior but rarely reveal whether a particular statistically significant change is biologically significant. To determine which behavioral changes are most important for multicellular self-organization, we devised a new methodology using Myxococcus xanthus as a model system. During development, myxobacteria coordinate their movement to aggregate into spore-filled fruiting bodies. We investigate how aggregation is restored in two mutants, csgA and pilC, that cannot aggregate unless mixed with wild-type (WT) cells. To this end, we use cell tracking to follow the movement of fluorescently labeled cells in combination with data-driven agent-based modeling. The results indicate that just like WT cells, both mutants bias their movement toward aggregates and reduce motility inside aggregates. However, several aspects of mutant behavior remain uncorrected by WT, demonstrating that perfect recreation of WT behavior is unnecessary. In fact, synergies between errant behaviors can make aggregation robust. IMPORTANCE Self-organization into spatial patterns is evident in many multicellular phenomena. Even for the best-studied systems, our ability to dissect the mechanisms driving coordinated cell movement is limited. While genetic approaches can identify mutations perturbing multicellular patterns, the diverse nature of the signaling cues coupled to significant heterogeneity of individual cell behavior impedes our ability to mechanistically connect genes with phenotype. Small differences in the behaviors of mutant strains could be irrelevant or could sometimes lead to large differences in the emergent patterns. Here, we investigate rescue of multicellular aggregation in two mutant strains of Myxococcus xanthus mixed with wild-type cells. The results demonstrate how careful quantification of cell behavior coupled to data-driven modeling can identify specific motility features responsible for cell aggregation and thereby reveal important synergies and compensatory mechanisms. Notably, mutant cells do not need to precisely recreate wild-type behaviors to achieve complete aggregation.

scholarly journals Differential Regulation of White-Opaque Switching by Individual Subunits of Candida albicans Mediator

2013 ◽  
Vol 12 (9) ◽  
pp. 1293-1304 ◽  
Author(s):  
Anda Zhang ◽  
Zhongle Liu ◽  
Lawrence C. Myers
Keyword(s):  
Candida Albicans ◽  
Ectopic Expression ◽  
Small Subset ◽  
Content Type ◽  
Impaired Ability ◽  
Transcriptional Effect ◽  
Environmental Induction ◽  
Gene Regulatory ◽  
The Stability ◽  
Negative Gene

ABSTRACT The multisubunit eukaryotic Mediator complex integrates diverse positive and negative gene regulatory signals and transmits them to the core transcription machinery. Mutations in individual subunits within the complex can lead to decreased or increased transcription of certain subsets of genes, which are highly specific to the mutated subunit. Recent studies suggest a role for Mediator in epigenetic silencing. Using white-opaque morphological switching in Candida albicans as a model, we have shown that Mediator is required for the stability of both the epigenetic silenced (white) and active (opaque) states of the bistable transcription circuit driven by the master regulator Wor1. Individual deletions of eight C. albicans Mediator subunits have shown that different Mediator subunits have dramatically diverse effects on the directionality, frequency, and environmental induction of epigenetic switching. Among the Mediator deletion mutants analyzed, only Med12 has a steady-state transcriptional effect on the components of the Wor1 circuit that clearly corresponds to its effect on switching. The MED16 and MED9 genes have been found to be among a small subset of genes that are required for the stability of both the white and opaque states. Deletion of the Med3 subunit completely destabilizes the opaque state, even though the Wor1 transcription circuit is intact and can be driven by ectopic expression of Wor1. The highly impaired ability of the med3 deletion mutant to mate, even when Wor1 expression is ectopically induced, reveals that the activation of the Wor1 circuit can be decoupled from the opaque state and one of its primary biological consequences.

Telepresence robotics in an academic library

2017 ◽  
Vol 35 (3) ◽  
pp. 408-420 ◽  
Author(s):  
LuMarie Guth ◽  
Patricia Vander Meer
Keyword(s):  
Public Relations ◽  
Public Services ◽  
Academic Library ◽  
Training Session ◽  
Employee Attitudes ◽  
Remote Communication ◽  
Content Type ◽  
Special Events ◽  
Before And After ◽  
Positive Results

Purpose Librarians are working with telepresence robotics for various uses, particularly as a communication method inhabiting a space between video chat and face-to-face interactions. The library at (Blinded University) partnered with the (Blinded Laboratory) to showcase this emerging technology in a high-traffic setting utilized by students of every level and major. The purpose of this paper is to discuss patron reactions to this technology exhibition in the library, beta testing of a telepresence robot in various public services tasks, and library employee attitudes toward this unfamiliar technology before and after one-on-one training. Design/methodology/approach The project gathered data through three studies. In study 1, feedback forms were filled out by patrons who interacted with or piloted the robot. In study 2, observations by the librarians piloting the robot for various public services activities were recorded in a log. In study 3, employees were invited to complete a pretest designed to solicit perceptions and attitudes regarding the use of the robot, become trained in navigating the robot, and complete a posttest for comparison purposes. Results were analyzed to find trends and highlight perceived uses for the technology. Findings Patrons and library employees gave positive feedback regarding the novelty of the technology and appreciated its remote communication capability. Trialed uses of the technology for public services yielded positive results when the TR was used for public relations, such as at special events or in greeting tours, and yielded less positive results when used for reference purposes. Library employees comfort with and perceived utility of the robot grew consistently across departments, levels of experience and employment types after a personal training session. Originality/value Although libraries in recent years have surveyed users regarding TR technology, this paper captures quantitative and qualitative data from a library employee training study regarding perception of the technology. Exploration of the public services uses and library employee acceptance of TR technology is valuable to those contemplating expending time and resources in similar endeavors.

scholarly journals Evidence on why firms use different disclosure outlets

2016 ◽  
Vol 29 (3) ◽  
pp. 274-291
Author(s):  
Alexey Feigin ◽  
Andrew Ferguson ◽  
Matthew Grosse ◽  
Tom Scott
Keyword(s):  
Empirical Evidence ◽  
Information Content ◽  
Information Acquisition ◽  
Voluntary Disclosure ◽  
Abnormal Return ◽  
Design Methodology ◽  
Small Subset ◽  
Market Reactions ◽  
Content Type ◽  
Acquisition Costs

Purpose The purpose of this study is to consider why firms use different disclosure outlets. The authors argue that the firm's choice of disclosure outlet can be explained by voluntary disclosure theories and investigate whether the market response around different disclosure outlets varies. Design/methodology/approach The authors investigate differences in the characteristics of firms purchasing analyst research, holding investor presentations or Open Briefings and compare market reactions around each disclosure event. Findings The authors find that firm incentives to reduce information acquisition costs or mitigate disclosure risk affect firm disclosure outlet choice, and mixed evidence in support of talent signalling motivations. There is a lower absolute abnormal return around Open Briefings and a higher signed abnormal return around purchased analyst research. Research limitations/implications The research is exploratory in nature and only considers a small subset of disclosure outlets. There may be differences in information content across disclosure outlets. Originality/value They show disclosure outlets are not homogenous and provide empirical evidence voluntary disclosure theories help explain differences between firms’ use of disclosure outlets. Considering the growing number of disclosure outlets available, disclosure outlet choice is likely to be an increasingly important topic in accounting research.

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