Survival Strategies Research Articles

Bacterial cell differentiation enables population level survival strategies.

Clonal reproduction of unicellular organisms ensures the stable inheritance of genetic information. However, this means of reproduction lacks an intrinsic basis for genetic variation, other than spontaneous mutation and horizontal gene transfer. To make up for this lack of genetic variation, many unicellular organisms undergo the process of cell differentiation to achieve phenotypic heterogeneity within isogenic populations. Cell differentiation is either an inducible or obligate program. Induced cell differentiation can occur as a response to a stimulus, such as starvation or host cell invasion, or it can be a stochastic process. In contrast, obligate cell differentiation is hardwired into the organism's life cycle. Whether induced or obligate, bacterial cell differentiation requires the activation of a signal transduction pathway that initiates a global change in gene expression and ultimately results in a morphological change. While cell differentiation is considered a hallmark in the development of multicellular organisms, many unicellular bacteria utilize this process to implement survival strategies. In this review, we describe well-characterized cell differentiation programs to highlight three main survival strategies used by bacteria capable of differentiation: (i) environmental adaptation, (ii) division of labor, and (iii) bet-hedging.

Type I toxin-antitoxin systems in bacteria: from regulation to biological functions.

Toxin-antitoxin systems are ubiquitous in the prokaryotic world and widely distributed among chromosomes and mobile genetic elements. Several different toxin-antitoxin system types exist, but what they all have in common is that toxin activity is prevented by the cognate antitoxin. In type I toxin-antitoxin systems, toxin production is controlled by an RNA antitoxin and by structural features inherent to the toxin messenger RNA. Most type I toxins are small membrane proteins that display a variety of cellular effects. While originally discovered as modules that stabilize plasmids, chromosomal type I toxin-antitoxin systems may also stabilize prophages, or serve important functions upon certain stress conditions and contribute to population-wide survival strategies. Here, we will describe the intricate RNA-based regulation of type I toxin-antitoxin systems and discuss their potential biological functions.

State intervention and tourism business resilience: Exploring firm-level crisis responses

Business resilience and government intervention are critical in navigating crises. Guided by resilience theory and concepts of state intervention in global crises, this article examines firm-level strategies to the Covid-19 pandemic. The qualitative findings decipher adaptive resilience and business survival strategies concerning cashflow management, human resource management, management of current liabilities, asset management, and alternative business avenues. Government intervention included financial assistance, wage subsidy, loan moratorium, and other stimulus measures. Findings reveal mixed responses, highlighting the need for tailored and effective government intervention. The study extends resilience theory by integrating state intervention as an external driver of adaptive resilience, thereby providing a holistic understanding of resilience in crises. Practical implications provide policy-makers with insights on more effective crisis response strategies.

Similar chilling response of dormant buds in potato tuber and woody perennials.

Bud dormancy is a survival strategy that plants have developed in their native habitats. It helps them endure harsh seasonal changes by temporarily halting growth and activity until conditions become more favorable. Research has primarily focused on bud dormancy in tree species and the ability to halt growth in vegetative tissues, particularly in meristems. Various plant species, such as potato, have developed specialized storage organs, enabling them to become dormant during their yearly growth cycle. Deciduous trees and potato tubers exhibit a similar type of bud endodormancy (ED), where the bud meristem will not initiate growth, even under favorable environmental conditions. Chilling accumulation activates C-repeat/dehydration responsive element binding (DREB) factors (CBFs) transcription factors that modify the expression of dormancy-associated genes. Chilling conditions shorten the duration of ED by influencing plant hormones and sugar metabolism, which impact the timing and rate of bud growth. Sugar metabolism and signaling pathways can interact with abscisic acid (ABA), affecting the symplastic connection of dormant buds. This review explores how chilling affects ED duration and explores the similarity of the chilling response of dormant buds in potato tuber and woody perennials.

Ethnobotanical insights into the traditional food plants of the Baiku Yao community: a study of cultural significance, utilization, and conservation

BackgroundThe Baiku Yao, primarily residing in Guangxi and Guizhou provinces of China, is a distinctive branch of the Yao ethnic group, known for their profound cultural preservation and unique ethnobotanical knowledge. This study investigates the Baiku Yao community’s utilization of traditional food plants, focusing on the relationship between their dietary practices and the local biodiversity within their mountainous living environment. It aims to illuminate the cultural significance and survival strategies embedded in their ethnobotanical knowledge, highlighting the potential for sustainable living and biodiversity conservation.MethodsThrough ethnobotanical surveys, key informant interviews, and quantitative analysis techniques such as the cultural food significance index (CFSI) and relative frequency of citations (RFC), this research systematically documents the diversity and cultural importance of edible plants in the Baiku Yao community. The study assesses how these plants contribute to the community’s diet, traditional medicine, and overall cultural practices.ResultsA total of 195 traditional edible plants were documented, belonging to 142 genera and 68 families, with a significant concentration in certain families such as Asteraceae, Rosaceae, and Fabaceae. The Baiku Yao diet prominently features herbaceous plants, with wild (103 species) and cultivated (89 species) varieties as diverse food sources. They utilize various plant parts, particularly fruits and leaves, for multiple purposes, including nutrition, medicine, and fodder. Their processing techniques, from raw to fermented, showcase a rich culinary tradition and emphasize a holistic use of plants for enhancing diet and health in a concise overview. The RFC and CFSI analyses reveal a deep cultural reliance on a variety of plant species, with a notable emphasis on vegetables, fruits, spices, and medicinal herbs. Specific plants like Zingiber officinale, Zea mays, and Oryza sativa were highlighted for their high cultural significance. The study also uncovers the multifunctional use of these plants, not only as food but also for medicinal purposes, fodder, and other cultural applications, reflecting the Baiku Yao’s profound ecological wisdom and their harmonious coexistence with nature.ConclusionThe findings emphasize the rich ethnobotanical knowledge possessed by the Baiku Yao, underscoring the importance of documenting, safeguarding, and transmitting this invaluable traditional knowledge. This study contributes to a deeper understanding of cultural heritage and biodiversity conservation, advocating for concerted efforts to protect such traditional practices against the threats of modernization and cultural erosion.

Understanding the transition to viable but non-culturable state in Escherichia coli W3110: a comprehensive analysis of potential spectrochemical biomarkers.

The viable but non-culturable (VBNC) state is considered a survival strategy employed by bacteria to endure stressful conditions, allowing them to stay alive. Bacteria in this state remain unnoticed in live cell counts as they cannot proliferate in standard culture media. VBNC cells pose a significant health risk because they retain their virulence and can revive when conditions normalize. Hence, it is crucial to develop fast, reliable, and cost-effective methods to detect bacteria in the VBNC state, particularly in the context of public health, food safety, and microbial control assessments. This research examined the biomolecular changes in Escherichia coli W3110 induced into the VBNC state in artificial seawater under three different stress conditions (temperature, metal, and antibiotic). Initially, confirmation of VBNC cells under various stresses was done using fluorescence microscopy and plate counts. Subsequently, lipid peroxidation was assessed through the TBARS assay, revealing a notable increase in peroxidation end-products in VBNC cells compared to controls. ATR-FTIR spectroscopy and chemomometrics were employed to analyze biomolecular changes, uncovering significant spectral differences in RNA, protein, and nucleic acid concentrations in VBNC cells compared to controls. Notably, RNA levels increased, while protein and nucleic acid amounts decreased. ROC analyses identified the 995cm- 1 RNA band as a consistent marker across all studied stress conditions, suggesting its potential as a robust biomarker for detecting cells induced into the VBNC state under various stressors.

Maize miRNAs and their putative target genes involved in chilling stress response in 5-day old seedlings

BackgroundIn the context of early sowing of maize as a promising adaptation strategy that could significantly reduce the negative effects of climate change, an in-depth understanding of mechanisms underlying plant response to low-temperature stress is demanded. Although microRNAs (miRNAs) have been recognized as key regulators of plant stress response, research on their role in chilling tolerance of maize during early seedling stages is scarce. Therefore, it is of great significance to explore chilling-responsive miRNAs, reveal their expression patterns and associated target genes, as well as to examine the possible functions of the conserved and novel miRNAs. In this study, the role of miRNAs was examined in 5d-old maize seedlings of one tolerant and one sensitive inbred line exposed to chilling (10/8 °C) stress for 6 h and 24 h, by applying high throughput sequencing.ResultsA total of 145 annotated known miRNAs belonging to 30 families and 876 potentially novel miRNAs were identified. Differential expression (DE) analysis between control and stress conditions identified 98 common miRNAs for both genotypes at one time point and eight miRNAs at both time points. Target prediction and enrichment analysis showed that the DE zma-miR396, zma-miR156, zma-miR319, and zma-miR159 miRNAs modulate growth and development. Furthermore, it was found that several other DE miRNAs were involved in abiotic stress response: antioxidative mechanisms (zma-miR398), signal transduction (zma-miR156, zma-miR167, zma-miR169) and regulation of water content (zma-miR164, zma-miR394, zma-miR396). The results underline the zma-miRNAs involvement in the modulation of their target genes expression as an important aspect of the plant’s survival strategy and acclimation to chilling stress conditions.ConclusionsTo our understanding, this is the first study on miRNAs in 5-d old seedlings’ response to chilling stress, providing data on the role of known and novel miRNAs post-transcriptional regulation of expressed genes and contributing a possible platform for further network and functional analysis.

Characteristics and immune functions of the endogenous CRISPR-Cas systems in myxobacteria.

Serving as an adaptive immune system, clustered regularly interspaced short palindromic repeats and their associated proteins (CRISPR-Cas) empower prokaryotes to fend off the intrusion of external genetic materials. Myxobacteria are a collective of swarming Gram-stain-negative predatory bacteria distinguished by intricate multicellular social behavior. An in-depth analysis of their intrinsic CRISPR-Cas systems is beneficial for our understanding of the survival strategies employed by host cells within their environmental niches. Moreover, the experimental findings presented in this study not only suggest the robust immune functions of CRISPR-Cas in myxobacteria but also their potential applications.

Identification of ClpB, a molecular chaperone involved in the stress tolerance and virulence of Streptococcus agalactiae

Bacterial ClpB is an ATP-dependent disaggregate that belongs to the Hsp100/Clp family and facilitates bacterial survival under hostile environmental conditions. Streptococcus agalactiae, which is regarded as the major bacterial pathogen of farmed Nile tilapia (Oreochromis niloticus), is known to cause high mortality and large economic losses. Here, we report a ClpB homologue of S. agalactiae and explore its functionality. S. agalactiae with a clpB deletion mutant (∆clpB) exhibited defective tolerance against heat and acidic stress, without affecting growth or morphology under optimal conditions. Moreover, the ΔclpB mutant exhibited reduced intracellular survival in RAW264.7 cells, diminished adherence to the brain cells of tilapia, increased sensitivity to leukocytes from the head kidney of tilapia and whole blood killing, and reduced mortality and bacterial loads in a tilapia infection assay. Furthermore, the reduced virulence of the ∆clpB mutant was investigated by transcriptome analysis, which revealed that deletion of clpB altered the expression levels of multiple genes that contribute to the stress response as well as certain metabolic pathways. Collectively, our findings demonstrated that ClpB, a molecular chaperone, plays critical roles in heat and acid stress resistance and virulence in S. agalactiae. This finding provides an enhanced understanding of the functionality of this ClpB homologue in gram-positive bacteria and the survival strategy of S. agalactiae against immune clearance during infection.

Dynamics and drivers of fungal communities in a multipartite ant-plant association

BackgroundFungi and ants belong to the most important organisms in terrestrial ecosystems on Earth. In nutrient-poor niches of tropical rainforests, they have developed steady ecological relationships as a successful survival strategy. In tropical ant-plant mutualisms worldwide, where resident ants provide the host plants with defense and nutrients in exchange for shelter and food, fungi are regularly found in the ant nesting space, inhabiting ant-made dark-colored piles (“patches”). Unlike the extensively investigated fungus-growing insects, where the fungi serve as the primary food source, the purpose of this ant-fungi association is less clear. To decipher the roles of fungi in these structures within ant nests, it is crucial to first understand the dynamics and drivers that influence fungal patch communities during ant colony development.ResultsIn this study, we investigated how the ant colony age and the ant-plant species affect the fungal community in the patches. As model we selected one of the most common mutualisms in the Tropics of America, the Azteca-Cecropia complex. By amplicon sequencing of the internal transcribed spacer 2 (ITS2) region, we analyzed the patch fungal communities of 93 Azteca spp. colonies inhabiting Cecropia spp. trees. Our study demonstrates that the fungal diversity in patches increases as the ant colony grows and that a change in the prevalent fungal taxa occurs between initial and established patches. In addition, the ant species significantly influences the composition of the fungal community in established ant colonies, rather than the host plant species.ConclusionsThe fungal patch communities become more complex as the ant colony develops, due to an acquisition of fungi from the environment and a substrate diversification. Our results suggest a successional progression of the fungal communities in the patches during ant colony growth and place the ant colony as the main driver shaping such communities. The findings of this study demonstrate the unexpectedly complex nature of ant-plant mutualisms in tropical regions at a micro scale.

Women’s Homelessness and the Justice System: A Study of Desistance and Social (Re)integration Among Canadian Women Who Used or Did Not Use Criminal Activities to Survive

Women experiencing homelessness (WEH) are a marginalized group who often lack support services, leading them to adopt alternative survival strategies that leave them at risk of being victimized and becoming involved with the justice-system. To better understand this problem, we analyzed the adaptive strategies Canadian WEH use to survive. Comparing the life histories of WEH who turned to criminal activities ( n = 4) with WEH who demonstrated prosocial resilience ( n = 4) makes it possible to identify protective and risk factors for criminal behavior and to propose adaptive strategies that can be used to support these women to adopt a prosocial lifestyle. The results provide a framework for understanding the needs of WEH, filling a gap that results from the focus on men needs in most scientific literature and by many resources, and suggesting that meeting those needs may reduce the likelihood that WEH will become involved with the justice-system.

Antarctica's hidden mycoviral treasures in fungi isolated from mosses: A first genomic approach.

This study investigates the presence of mycoviruses in Antarctic fungi and elucidates their evolutionary relationships. To achieve this, we aligned mycoviral gene sequences with genomes of previously sequenced Antarctic endophytic fungi, made available by our research group and accessible via Joint Genome Institute. Our findings reveal that the most prevalent genetic regions in all endophytic fungi are homologous to Partitiviruses, Baculoviridae, and Phycodnaviridae. These regions display evidence of positive selection pressure, suggesting genetic diversity and the accumulation of nonsynonymous mutations. This phenomenon implies a crucial role for these regions in the adaptation and survival of these fungi in the challenging Antarctic ecosystems. The presence of mycoviruses in Antarctic endophytic fungi may indicate shared survival strategies between the virus and its host, shedding light on their evolutionary dynamics. This study underscores the significance of exploring mycoviruses within endophytic fungi and their contributions to genetic diversity. Future research avenues could delve into the functional implications of these conserved mycoviral genetic regions in Antarctic endophytic fungi, providing a comprehensive understanding of this intriguing association and genomic retention of viral region in fungi.

Microscopic and molecular genetic analyses of morphological development of the actinomycete Actinoplanes missouriensis.

The survival strategy of members of the bacterial genus Actinoplanes is fascinating from morphological and evolutionary perspectives. A brief motile phase is incorporated in the filamentous and resting stages of the life cycle of Actinoplanes missouriensis. Spores either lie dormant or swim under different external conditions. This review presents microscopic observations and molecular genetic analyses of A. missouriensis morphological development. Selected examples of the characterization of developmental genes and their products are also introduced.

An antifungal compound secreted by termite workers, phenylacetic acid, inhibits the growth of both termite egg-mimicking fungus and entomopathogenic fungi

AbstractSocial insects live in closely related family groups but face risks of intrusion and infection by pathogenic and parasitic microbes. To cope with the microbes invading their nests and feeding sites, social insects produce various types of antimicrobial substances. Subterranean termites occupy microbe-rich decaying wood and soil at high density, expanding their nest area by exploring and feeding on wood outward from the royal chamber (room for kings and queens). Although antimicrobial agents have been identified in many termite species, few studies have investigated those used by foraging workers in decaying wood under development, which is richer in microbes than the well-sterilized royal chamber and its surroundings. Here, we report that phenylacetic acid, an antifungal aromatic compound, is secreted by foraging workers of the Japanese subterranean termite Reticulitermes speratus. The compound was detected by gas chromatography–mass spectrometry analysis of ethyl acetate extracts of shelter papers infested with the workers, and antimicrobial tests demonstrated that it inhibits the germination and/or mycelial growth of the entomopathogenic fungi (Metarhizium anisopliae and Beauveria bassiana) and the termite egg-mimicking fungus Athelia termitophila. Our study provides new insights into the antimicrobial defense mechanisms of termites, including by combining different types of antimicrobial substances secreted by different castes, and thus the survival strategy of entomopathogenic and parasitic fungi in termite nests.

Exploring the Scientific Mechanism of Tree Structure Network based on LiDAR Point Cloud Data

Abstract. To explore how trees optimize their structure, we developed a method based on Pareto optimality theory. This method consists of the following operations. Firstly, we utilize Quantitative Structure Models for Single Trees from Laser Scanner Data (TreeQSM) to extract tree structures from point clouds acquired through Light Detection and Ranging (LiDAR). Subsequently, we utilize a graph-theoretical model to characterize the natural tree structure networks and implement a greedy algorithm to generate Pareto optimal tree structure networks. Finally, based on the Pareto optimality theory, we explore whether tree structures are multi-objective optimized. This paper demonstrates that tree structures lie along the Pareto front between minimizing "transport distance" and minimizing "total length". The growth pattern of trees, which produces multi-objective optimized structures, is likely an intrinsic mechanism in the generation of tree structure networks. The location of tree structures along the Pareto front varies under different environmental conditions, reflecting their diverse survival strategies.

Starostniki na podeželju v 19. stoletju

Based on individual case studies and employing discourse analysis in Carniola, this study endeavours to transcend the existing theories that predominantly place the rural elderly within multigenerational familial structures. By delving into the intricacies of property transfer, the employment possibilities of individuals lacking assets, marital strategies, obstacles and dynamics, and the provision of care for elderly family members in rural areas, a nuanced understanding emerges. The present research reveals diverse strategies, identities, and configurations in the lifestyles and livelihoods of the rural elderly, which extend beyond conventional family-centric perspectives. By emphasising the intricate interplay of property dynamics, survival strategies, and communal solidarity, this article sheds light on the multifaceted life of the elderly in the countryside.

Defensive Strategy Analysis of Bag Handicraft Industry in SME Centers

With the rapid development of technology, various problems arise in producing and marketing handicraft products. Thus, this research aims to determine the survival strategies and provide a clear and detailed picture of the characteristics or attributes of research subjects without testing hypotheses or drawing causal conclusions. The research object is the bag craftsmens in Sukaregang, Garut Regency West Java, Indonesia. Both interview techniques and literacy studies were used to obtain the strengths, weaknesses, opportunities, and threats. Then, weighting is carried out, and a value is given; the weight and value are multiplied to get a total score. The existing IFAS and EFAS values are entered into quadrants. It is found that the position of Sukaregang bag craftsmen is in quadrant 1 which aims to take advantage of internal strengths and external opportunities. The strategy that can be applied is to improve the quality of raw materials so that they can produce good, high-quality, and high-value products. These findings are expected to provide insights for handicrafts to survive this digital era. Keywords: Economy; Management; Defensive Strategy; SWOT; SMEs

How are Trypanosoma brucei receptors protected from host antibody-mediated attack?

Trypanosoma brucei is the causal agent of African Trypanosomiasis in humans and other animals. It maintains a long-term infection through an antigenic variation based population survival strategy. To proliferate in a mammal, T. brucei acquires iron and haem through the receptor mediated uptake of host transferrin and haptoglobin-hemoglobin respectively. The receptors are exposed to host antibodies but this does not lead to clearance of the infection. Here we discuss how the trypanosome avoids this fate in the context of recent findings on the structure and cell biology of the receptors.

Food Sales Activities Associated to Family Survival Strategies During Covid-19 Lockdown in Brazzaville, Congo

The COVID-19 pandemic has a negative impact on people's living conditions, particularly in sub-Saharan Africa in vulnerable and low-income families. The aim of this work is to analyze the socio-demographic profile of people who engaged in food sales activities during the COVID-19 lockdown in Brazzaville, as well as their coping and survival strategies. The study, which used a mixed (qualitative and quantitative) approach, included 716 people (241 men and 475 women) aged 18 to 72 years residing in four communes in the southern zone of Brazzaville, Republic of Congo. The main study inclusion criterion was the practice of selling food during COVID-19 lockdown. However, we did not include people whose profession had been selling these products prior to the health crisis. The qualitative data collected during the interviews concerned information on vendors, sales locations, coping strategies used to find the products sold, and sales prices. As for the qualitative data assessed using a food questionnaire, they were summarized in terms of the quality and quantity of food consumed, which made it possible to assess daily energy intake and therefore the level of food security. The results showed that the sellers, with an average age of 42.7, had a relatively low level of education and lived in a medium-sized family (8). Of these, 21.8% were food insecure. Foodstuffs sold were dominated by miscellaneous products (48.2%), street foods (26.7%), ready-made meals (22.3%), cassava flour (17.4%) and fruit and vegetables (7.5%). Salted fish, smoked fish and frozen (imported) meat products were also sold. As far as prepared dishes were concerned, grilled meats of various kinds were the most popular. Sales outlets included state markets, neighborhood markets, storefronts and street markets for auctions. The use of rickshaws and wheelbarrows by a few money-seeking youngsters enabled the products purchased to be transported from the places of purchase to the various markets or sales sites. In short, given the absence of an effective distribution and marketing policy in the food system in times of crisis in the Congo, our results call into question the resilience of vulnerable populations in the face of the country's sociosanitary crises.

Integrating multi-platform assembly to recover MAGs from hot spring biofilms: insights into microbial diversity, biofilm formation, and carbohydrate degradation

BackgroundHot spring biofilms provide a window into the survival strategies of microbial communities in extreme environments and offer potential for biotechnological applications. This study focused on green and brown biofilms thriving on submerged plant litter within the Sungai Klah hot spring in Malaysia, characterised by temperatures of 58–74 °C. Using Illumina shotgun metagenomics and Nanopore ligation sequencing, we investigated the microbial diversity and functional potential of metagenome-assembled genomes (MAGs) with specific focus on biofilm formation, heat stress response, and carbohydrate catabolism.ResultsLeveraging the power of both Illumina short-reads and Nanopore long-reads, we employed an Illumina-Nanopore hybrid assembly approach to construct MAGs with enhanced quality. The dereplication process, facilitated by the dRep tool, validated the efficiency of the hybrid assembly, yielding MAGs that reflected the intricate microbial diversity of these extreme ecosystems. The comprehensive analysis of these MAGs uncovered intriguing insights into the survival strategies of thermophilic taxa in the hot spring biofilms. Moreover, we examined the plant litter degradation potential within the biofilms, shedding light on the participation of diverse microbial taxa in the breakdown of starch, cellulose, and hemicellulose. We highlight that Chloroflexota and Armatimonadota MAGs exhibited a wide array of glycosyl hydrolases targeting various carbohydrate substrates, underscoring their metabolic versatility in utilisation of carbohydrates at elevated temperatures.ConclusionsThis study advances understanding of microbial ecology on plant litter under elevated temperature by revealing the functional adaptation of MAGs from hot spring biofilms. In addition, our findings highlight potential for biotechnology application through identification of thermophilic lignocellulose-degrading enzymes. By demonstrating the efficiency of hybrid assembly utilising Illumina-Nanopore reads, we highlight the value of combining multiple sequencing methods for a more thorough exploration of complex microbial communities.