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1.
J Clin Med ; 13(17)2024 Sep 09.
Article in English | MEDLINE | ID: mdl-39274547

ABSTRACT

Background: Urinary tract infection is a worldwide health problem. According to the Clinical Laboratory Improvement Amendments and the European Urinalysis Guideline, urine samples should be tested within 2 h of collection. Thus, using chemical preservatives that guarantee the pre-analytical conditions is a practical tool. However, the effects of temperature and storage time as uropathogenic bacteria stressors are unclear. Methods: Gram-negative and -positive ATTC strains, E. coli, P. mirabilis, E. faecalis, and S. aureus, were used in this study. Strains in liquid media were stored at 4, 25, and 37 °C for 0, 2, 12, 24, and 48 h in tubes with and without preservatives. Then, reactive oxygen species (ROS) levels, viable but non-culturable bacteria (VBNC), and bacteria growth were analyzed. Results: A high ROS level was associated with the presence of VBNC and dead bacteria with low CFU counts, but a low ROS level increased the CFU number, depending on temperature and storage time in tubes without preservatives (boric acid, sodium borate, and formate). The BD Vacutainer™ Urine Culture & Sensitivity Preservative PLUS Plastic Tubes (C&S-PP) prevent this ROS increase, maintaining the CFU number for longer. Conclusions: C&S-PP tubes minimize the stressor effects (temperature and time storage) on uropathogenic bacteria when stored, improving the pre-analytical conditions of cultures realized by the clinical laboratory.

2.
Environ Monit Assess ; 196(9): 813, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-39145782

ABSTRACT

The presence of microplastics in freshwater systems can have harmful effects on the food chain. Zooplankton, especially suspension and filter feeders, can ingest microplastics, which can cause adverse effects and transfer them to higher trophic levels. Here, we analyze the presence, abundance, and distribution of microplastics in surface water, zooplankton, and fish in two tropical lakes in central Mexico. We collected water samples in triplicate at three sites in each lake and 120 fish of the genus Chirostoma. From each water sample, 300 rotifers and 150 microcrustaceans were randomly isolated and processed independently. Of the particles found in the water, zooplankton, and fish from both lakes, the fragments were the predominant ones. The total abundance of microplastics in the water column of both lakes varied between 1.2 and 17.0 items L-1. In zooplankton, fragments were found predominantly with up to 0.1 items ind-1, while in fish, up to 4.5 items ind-1 was recorded. Our results confirm the presence of microplastics in different compartments of the food webs of freshwater bodies, water column, zooplankton, and fish. Further work is required on the possible effects of these stressors at the different trophic levels.


Subject(s)
Environmental Monitoring , Fishes , Lakes , Microplastics , Water Pollutants, Chemical , Zooplankton , Animals , Lakes/chemistry , Mexico , Water Pollutants, Chemical/analysis , Microplastics/analysis , Food Chain
3.
Rev Argent Microbiol ; 56(3): 241-248, 2024.
Article in English | MEDLINE | ID: mdl-39089979

ABSTRACT

Cildáñez stream (in Matanza-Riachuelo basin, Buenos Aires) is one of the most polluted watercourses of Argentina, containing a mixed contamination from agricultural and industrial wastes. The application of water bioremediation processes for this kind of effluent will require microorganisms with a high tolerance to contamination. In this sense, obtaining higher contaminant-resistant microalgae lines is widely desired. In this study, adaptive laboratory evolution (ALE) and random mutagenesis were used to obtain Chlorella vulgaris LMPA-40 strains adapted to grow in polluted water from the Cildáñez stream. The ALE process was performed by 22 successive subcultures under selective pressure (Cildáñez wastewater alone or with the addition of phenol or H2O2) while random mutagenesis was performed with UV-C radiation at 275nm. Not all the cell lines obtained after ALE could adapt enough to overcome the stress caused by the Cildáñez wastewater, indicating that the process is quite random and depends on the stressor used. The best results were obtained for the Cildáñez wastewater adapted cells (Cild 3 strain) that were more resistant than the original strain. The concentration of protein, Chlorophyll A, Chlorophyll B, and carotenoids in the Cild 3 ALE evolved strain was higher than that of the control strain. However, this strain exhibited half of the lipid content compared to the same control strain. Interestingly, these alterations and the acquired tolerance may be reversed over time during storage. These findings suggest that the acquisition of novel cell lines could not be permanent, a fact that must be considered for future trials.


Subject(s)
Chlorella vulgaris , Chlorella vulgaris/genetics , Wastewater/microbiology , Argentina , Biodegradation, Environmental , Directed Molecular Evolution , Mutagenesis , Chlorophyll A , Chlorophyll/analysis , Hydrogen Peroxide/pharmacology
4.
Front Psychol ; 15: 1386235, 2024.
Article in English | MEDLINE | ID: mdl-39077211

ABSTRACT

The COVID-19 pandemic has generated a global crisis with severe consequences for public health. There have been negative impacts on people's quality of life and mental health due to various stressors arising in this context, such as physical, social, economic, and psychological challenges. Noteworthy among these are the indirect effects of health measures, especially social distancing and confinement, which have significantly altered people's daily lives and social activities, producing high levels of anxiety, depression, and stress. This study proposes developing and validating a cross-sectional scale called the "Environmental Stressors Scale (ECSS-20)" to address the need to measure the impact of environmental stressors during confinement. The scale, which has been validated following ethical and methodological guidelines, consists of four dimensions: economic stressors (EE), social activities (SA), habitability (H), and exposure to virtual media (EMV). A pilot study (n = 113) and a main study (n = 314) were applied. The results showed that the instrument has a reliable and valid structure, with satisfactory internal consistency and factorial validity. Likewise, gender invariance tests supported its suitability for its applicability to women and men. Overall, the ECSS-20 is a valuable instrument for assessing the impact of confinement and improving the understanding of people's subjective experiences in this situation. Future research could further develop its applicability in different contexts and populations to better understand its usefulness and psychometric properties.

5.
Ecotoxicology ; 33(7): 818-829, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38990494

ABSTRACT

Temperature can interact with chemical pesticides and modulate their toxicity. Sublethal exposure to pesticides is known to trigger hormetic responses in pests. However, the simultaneous effects of temperature and sublethal exposure to single or mixture-based insecticides on the insects' stimulatory responses are not frequently considered in toxicological studies. Here we investigated the combined effects of temperature on the lethal and sublethal responses of the green peach aphid Myzus persicae after exposure to commercial formulations of a neonicotinoid (thiamethoxam) and a pyrethroid (lambda-cyhalothrin) and their mixture. Firstly, the concentration-response curves of the insecticides were determined under four temperatures (15 °C, 20 °C, 25 °C, and 28 °C) by the leaf dipping method. Subsequently, the sublethal concentrations C0, CL1, CL5, CL10, CL15, CL20, and CL30 were selected to assess sublethal effects on aphids' longevity and reproduction under the same temperatures. The results showed that the mixture of thiamethoxam + lambda-cyhalothrin caused greater toxicity to aphids compared to the formulations with each active ingredient alone and that the toxicity was higher at elevated temperatures. Furthermore, the exposure to low concentrations of the mixture (thiamethoxam + lambda-cyhalothrin) and the separated insecticides induced stimulatory responses in the longevity and fecundity of exposed aphid females, but the occurrence of such hormetic responses depended on the insecticide type, its sublethal concentration, and the temperature as well as their interactions.


Subject(s)
Aphids , Insecticides , Nitriles , Pyrethrins , Temperature , Thiamethoxam , Animals , Aphids/drug effects , Aphids/physiology , Insecticides/toxicity , Pyrethrins/toxicity , Nitriles/toxicity , Thiamethoxam/toxicity , Neonicotinoids/toxicity , Nitro Compounds/toxicity , Reproduction/drug effects , Hormesis
6.
Arch Microbiol ; 206(6): 285, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38816572

ABSTRACT

Intracellular pathogens like Brucella face challenges during the intraphagocytic adaptation phase, where the modulation of gene expression plays an essential role in taking advantage of stressors to persist inside the host cell. This study aims to explore the expression of antisense virB2 RNA strand and related genes under intracellular simulation media. Sense and antisense virB2 RNA strands increased expression when nutrient deprivation and acidification were higher, being starvation more determinative. Meanwhile, bspB, one of the T4SS effector genes, exhibited the highest expression during the exposition to pH 4.5 and nutrient abundance. Based on RNA-seq analysis and RACE data, we constructed a regional map depicting the 5' and 3' ends of virB2 and the cis-encoded asRNA_0067. Without affecting the CDS or a possible autonomous RBS, we generate the deletion mutant ΔasRNA_0067, significantly reducing virB2 mRNA expression and survival rate. These results suggest that the antisense asRNA_0067 expression is promoted under exposure to the intraphagocytic adaptation phase stressors, and its deletion is associated with a lower transcription of the virB2 gene. Our findings illuminate the significance of these RNA strands in modulating the survival strategy of Brucella within the host and emphasize the role of nutrient deprivation in gene expression.


Subject(s)
Brucella abortus , Gene Expression Regulation, Bacterial , Brucella abortus/genetics , Brucella abortus/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , RNA, Bacterial/genetics , RNA, Bacterial/metabolism , Transcription, Genetic , RNA, Antisense/genetics , RNA, Antisense/metabolism , Stress, Physiological , Animals , Macrophages/microbiology
7.
Sci Total Environ ; 942: 173494, 2024 Sep 10.
Article in English | MEDLINE | ID: mdl-38810746

ABSTRACT

The soil is a vital resource that hosts many microorganisms crucial in biogeochemical cycles and ecosystem health. However, human activities such as the use of metal nanoparticles (MNPs), pesticides and the impacts of global climate change (GCCh) can significantly affect soil microbial communities (SMC). For many years, pesticides and, more recently, nanoparticles have contributed to sustainable agriculture to ensure continuous food production to sustain the significant growth of the world population and, therefore, the demand for food. Pesticides have a recognized pest control capacity. On the other hand, nanoparticles have demonstrated a high ability to improve water and nutrient retention, promote plant growth, and control pests. However, it has been reported that their accumulation in agricultural soils can also adversely affect the environment and soil microbial health. In addition, climate change, with its variations in temperature and extreme water conditions, can lead to drought and increased soil salinity, modifying both soil conditions and the composition and function of microbial communities. Abiotic stressors can interact and synergistically or additively affect soil microorganisms, significantly impacting soil functioning and the capacity to provide ecosystem services. Therefore, this work reviewed the current scientific literature to understand how multiple stressors interact and affect the SMC. In addition, the importance of molecular tools such as metagenomics, metatranscriptomics, proteomics, or metabolomics in the study of the responses of SMC to exposure to multiple abiotic stressors was examined. Future research directions were also proposed, focusing on exploring the complex interactions between stressors and their long-term effects and developing strategies for sustainable soil management. These efforts will contribute to the preservation of soil health and the promotion of sustainable agricultural practices.


Subject(s)
Climate Change , Metal Nanoparticles , Pesticides , Soil Microbiology , Metal Nanoparticles/toxicity , Soil Pollutants , Soil/chemistry , Ecosystem , Microbiota/drug effects , Agriculture/methods
8.
Sci Total Environ ; 932: 173025, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38723955

ABSTRACT

Contaminants of emerging concern (CECs), including microplastics, have been the focus of many studies due to their environmental impact, affecting biota and human health. The diverse land uses and occupation of watersheds are important parameters driving the occurrence of these contaminants. CECs such as pesticides, drugs, hormones, and industrial-origin substances were analyzed in urban/industrial (Atibaia) and agricultural (Preto/Turvo) watersheds located in São Paulo state, Brazil. A total of 24 CECs were investigated, and, as a result, only 5 (caffeine, carbendazim, atrazine, ametrine and 2-hydroxytrazine) were responsible for 81.73 % of the statistical difference between watersheds contamination profile. The Atibaia watershed presented considerable concentrations of caffeine (ranging from 75 to 2025 ng L-1), while carbendazim (44 to 1144 ng L-1) and atrazine (3 to 266 ng L-1) presented highest levels in Preto/Turvo watershed. In all sampling points, the cumulative potential aquatic life risk assessed by the NORMAN database indicates some level of environmental concern associated to pesticides and caffeine (risk quotient >1). Microplastics had been analyzed in both watersheds, being the white/transparent fragments in size between 100 and 250 µm the most detected in this study. The estimated abundance in the Atibaia watershed ranged from 349 to 2898 items m-3 presenting some influence of pluviosity, while in Rio Preto/Turvo ranged from 169 to 6370 items m-3, being more abundant in the dam area without a clear influence of pluviosity. In both basins, polyethylene and polypropylene were the most detected polymers, probably due to the intense use of single-use plastics in urban areas. Possibly, due to the distinct physic-chemical properties of microplastics and organic CECs, no correlations were observed between their occurrence, which makes us conclude that they have different transport mechanism, behavior, and fate in the environment.


Subject(s)
Agriculture , Environmental Monitoring , Microplastics , Water Pollutants, Chemical , Brazil , Water Pollutants, Chemical/analysis , Microplastics/analysis , Pesticides/analysis
9.
J Proteome Res ; 23(6): 2041-2053, 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38782401

ABSTRACT

Extracellular chemical cues constitute much of the language of life among marine organisms, from microbes to mammals. Changes in this chemical pool serve as invisible signals of overall ecosystem health and disruption to this finely tuned equilibrium. In coral reefs, the scope and magnitude of the chemicals involved in maintaining reef equilibria are largely unknown. Processes involving small, polar molecules, which form the majority components of labile dissolved organic carbon, are often poorly captured using traditional techniques. We employed chemical derivatization with mass spectrometry-based targeted exometabolomics to quantify polar dissolved phase metabolites on five coral reefs in the U.S. Virgin Islands. We quantified 45 polar exometabolites, demonstrated their spatial variability, and contextualized these findings in terms of geographic and benthic cover differences. By comparing our results to previously published coral reef exometabolomes, we show the novel quantification of 23 metabolites, including central carbon metabolism compounds (e.g., glutamate) and novel metabolites such as homoserine betaine. We highlight the immense potential of chemical derivatization-based exometabolomics for quantifying labile chemical cues on coral reefs and measuring molecular level responses to environmental stressors. Overall, improving our understanding of the composition and dynamics of reef exometabolites is vital for effective ecosystem monitoring and management strategies.


Subject(s)
Coral Reefs , Metabolomics , Animals , Metabolomics/methods , Metabolome , United States Virgin Islands , Anthozoa/metabolism , Anthozoa/chemistry , Mass Spectrometry/methods , Ecosystem , Carbon/metabolism , Carbon/chemistry
10.
J Exp Biol ; 227(11)2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38774939

ABSTRACT

Anurans undergo significant physiological changes when exposed to environmental stressors such as low temperatures and humidity. Energy metabolism and substrate management play a crucial role in their survival success. Therefore, understanding the role of the gluconeogenic pathway and demonstrating its existence in amphibians is essential. In this study, we exposed the subtropical frog Boana pulchella to cooling (-2.5°C for 24 h) and dehydration conditions (40% of body water loss), followed by recovery (24 h), and assessed gluconeogenesis activity from alanine, lactate, glycerol and glutamine in the liver, muscle and kidney. We report for the first time that gluconeogenesis activity by 14C-alanine and 14C-lactate conversion to glucose occurs in the muscle tissue of frogs, and this tissue activity is influenced by environmental conditions. Against the control group, liver gluconeogenesis from 14C-lactate and 14C-glycerol was lower during cooling and recovery (P<0.01), and gluconeogenesis from 14C-glutamine in the kidneys was also lower during cooling (P<0.05). In dehydration exposure, gluconeogenesis from 14C-lactate in the liver was lower during recovery, and that from 14C-alanine in the muscle was lower during dehydration (P<0.05). Moreover, we observed that gluconeogenesis activity and substrate preference respond differently to cold and dehydration. These findings highlight tissue-specific plasticity dependent on the nature of the encountered stressor, offering valuable insights for future studies exploring this plasticity, elucidating the importance of the gluconeogenic pathway and characterizing it in anuran physiology.


Subject(s)
Anura , Cold Temperature , Dehydration , Gluconeogenesis , Animals , Gluconeogenesis/physiology , Anura/physiology , Anura/metabolism , Dehydration/physiopathology , Liver/metabolism , Kidney/metabolism , Kidney/physiology , Muscles/metabolism , Muscles/physiology , Male
11.
Parasitol Res ; 123(5): 204, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38709330

ABSTRACT

In recent years, there has been growing concern on the potential weakening of honey bees and their increased susceptibility to pathogens due to chronic exposure to xenobiotics. The present work aimed to study the effects on bees undergoing an infection by Nosema ceranae and being exposed to a frequently used in-hive acaricide, amitraz. To achieve this, newly emerged bees were individually infected with N. ceranae spores and/or received a sublethal concentration of amitraz in their diets under laboratory conditions. Mortality, food intake, total volume excrement, body appearance, and parasite development were registered. Bees exposed to both stressors jointly had higher mortality rates compared to bees exposed separately, with no difference in the parasite development. An increase in sugar syrup consumption was observed for all treated bees while infected bees fed with amitraz also showed a diminishment in pollen intake. These results coupled with an increase in the total number of excretion events, alterations in behavior and body surface on individuals that received amitraz could evidence the detrimental action of this molecule. To corroborate these findings under semi-field conditions, worker bees were artificially infected, marked, and released into colonies. Then, they were exposed to a commercial amitraz-based product by contact. The recovered bees showed no differences in the parasite development due to amitraz exposure. This study provides evidence to which extent a honey bee infected with N. ceranae could potentially be weakened by chronic exposure to amitraz treatment.


Subject(s)
Nosema , Toluidines , Animals , Bees/drug effects , Bees/microbiology , Bees/parasitology , Nosema/drug effects , Nosema/physiology , Acaricides
12.
Behav Sci (Basel) ; 14(4)2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38667127

ABSTRACT

The COVID-19 pandemic brought on a marked increase in intimate partner violence (IPV) worldwide, Mexico being no exception. Factors that exacerbated gender-based violence (GBV) in the household during the pandemic include gendered loss of income, regression in access to social and legal justice resources, reversal to more traditional gender norms and roles, and increased alcoholism. While there are studies about the prevalence and determinants of IPV in rural and urban Mexico, there appears to be a lack of information regarding how these realities differed as they interacted with the compounding pressures of the COVID-19 pandemic. Stemming from 10 ethnographic interviews with women across rural and urban localities of Oaxaca, Mexico City, and Mexico State, who were recruited from NGOs providing psychological and legal services against GBV, we analyze some factors associated with the prevalence of IPV during confinement. We conclude that all women in our study experienced IPV both before and during the pandemic, with variations in IPV patterns influenced by their rural or urban residence, socio-economic status, ethnic-racial identity, and proximity to the abuser's network. We also found that not all impacts were negative, rather COVID-19 measures had a paradoxical effect for some women where restrictions on geographical mobility and decrease in access to alcohol became pivotal protective factors. We recommend that public policymakers and civil society organizations alike pay attention to these differential challenges and benefits in their crisis responses.

13.
Animals (Basel) ; 14(5)2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38473149

ABSTRACT

Aquaculture has become one of the most attractive food production activities as it provides high-quality protein for the growing human population. However, the abiotic chronic stress of fish in intensive fish farming leads to a detrimental condition that affects their health and somatic growth, comprising productive performance. This work aims to comprehensively review the impact of alternative and novel dietary protein sources on fish somatic growth, metabolism, and antioxidative capacity under environmental/abiotic stressors. The documental research indicates that ingredients from rendered animal by-products, insects, bacteria as single-cell proteins, and fungal organisms (e.g., yeast, filamentous fungus, and mushrooms) benefit fish health and performance. A set of responses allows fish growth, health, and survival to remain unaffected by feeding with alternative ingredients during chronic environmental stress. Those ingredients stimulate the production of enzymes such as catalase, glutathione peroxidase, and selenoproteins that counteract ROS effects. In addition, the humoral immune system promotes immunoglobulin production (IgM) and cortisol plasmatic reduction. Further investigation must be carried out to establish the specific effect by species. Additionally, the mixture and the pre-treatment of ingredients such as hydrolysates, solid fermentations, and metabolite extraction potentialize the beneficial effects of diets in chronically stressed fish.

14.
PeerJ ; 12: e16980, 2024.
Article in English | MEDLINE | ID: mdl-38495757

ABSTRACT

In a competitive and demanding world, academic stress is of increasing concern to students. This systemic, adaptive, and psychological process is composed of stressful stimuli, imbalance symptoms, and coping strategies. The SISCO-II Academic Stress Inventory (SISCO-II-AS) is a psychometric instrument validated in Chile. It evaluates stressors, symptoms, and coping, both individually and globally. For its practical interpretation, a scale is required. Therefore, this study aims to descriptively analyze the SISCO-II-AS and to obtain its corresponding scales. Employing a non-experimental quantitative approach, we administered the SISCO-II-AS to 1,049 second and third-year students from three Chilean universities, with a disproportionate gender representation of 75.21% female to 24.79% male participants. Through descriptive and bivariate analysis, we established norms based on percentiles. For the complete instrument and its subscales, significant differences by sex were identified, with magnitudes varying from small to moderate. For the full instrument and its subscales, bar scale norms by percentile and sex are presented. Each subscale (stressors, physical and psychological reactions, social behavioural reactions, total reaction, and coping) has score ranges defined for low, medium, and high levels. These ranges vary according to the sex of the respondent, with notable differences in stressors and physical, psychological, and social behavioural reactions. This study stands out for its broad and heterogeneous sample, which enriches the representativeness of the data. It offers a comprehensive view of academic stress in college students, identifying distinctive factors and highlighting the importance of gender-sensitive approaches. Its findings contribute to understanding and guide future interventions. By offering a descriptive analysis of the SISCO-II-AS inventory and establishing bar norms, this research aids health professionals and educators in better assessing and addressing academic stress in the student population.


Subject(s)
Adaptation, Psychological , Stress, Psychological , Humans , Male , Female , Stress, Psychological/diagnosis , Cross-Sectional Studies , Students/psychology , Coping Skills
15.
J Feline Med Surg ; 26(3): 1098612X241233116, 2024 03.
Article in English | MEDLINE | ID: mdl-38546181

ABSTRACT

OBJECTIVES: This study aimed to determine the impact of acute stress on tear production in companion cats to provide a basis for minimizing stress-inducing stimuli during ophthalmic evaluations. METHODS: A total of 24 healthy owned cats (12 males, 12 females) of mixed breed, aged 8 months to 7 years, with no history of ocular diseases, were selected for the study. The cats were housed in individual cages under controlled conditions for 6 days. The Schirmer tear test-1 (STT-1) was performed in the morning (between 9:00 am and 11:00 am) using test strips from the same batch. The first test (without stress) was conducted on the fifth day of acclimation, and the second test (with stress) on the sixth day. The stress stimulus consisted of recordings of barking dogs, cats fighting and the murmuring of people. For both tests, the heart rate was assessed with a stethoscope before, during and after the tests, and the environmental stress level was also evaluated. Results are presented as mean ± SD and 95% confidence interval (CI). RESULTS: The study found that STT-1 values were significantly higher (P = 0.009) with stress (22.2 ± 6.0 mm/min [95% CI 19.9-24.6]) than without stress (17.5 ± 6.9 mm/min [95% CI 14.8-20.2]). Similarly, the heart rate was significantly higher (P = 0.028) in stress vs non-stress conditions (213.4 ± 37.5 beats per minute [bpm] [95% CI 198.7-228.1] vs 171.5 ± 28.6 bpm [95% CI 160.3-182.7], respectively), and the environmental stress score was significantly higher (P <0.001) in stress vs non-stress conditions (3.3 ± 0.5 [95% CI 3.1-3.5] vs 1.2 ± 0.4 [95% CI 1.1-1.4], respectively). CONCLUSIONS AND RELEVANCE: Stress increased tear production in cats. Although the mean STT-1 value obtained under stress conditions was within the normal range, stress can influence the test results. The use of cat friendly handling techniques facilitates execution of the STT-1.


Subject(s)
Lacrimal Apparatus , Tears , Male , Female , Cats , Animals , Dogs , Tears/physiology , Reference Values , Physical Examination
16.
Mar Pollut Bull ; 200: 116165, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38364642

ABSTRACT

We assessed the tolerance, safety margins, and behavioral responses to extreme conditions of the mangrove fiddler crab Leptuca speciosa during a heatwave event (May of 2022), in the Yucatán Peninsula, Mexico. In the field, L. speciosa demonstrated aggregation behavior, congregating in areas that were above the water level to escape the extreme water conditions. In the laboratory, we determined that the upper critical thermal limits (UT99) ranged from 40.2 °C and 42 °C. For salinity, the lethal concentration was LC99 = 39 psu. Our study showed that L. speciosa, one of the most conspicuous and resilient inhabitants of mangroves, had no safety margin and low tolerance to the climatic conditions as measured in the heatwave, and displayed a protective behavior. Considering that the frequency and intensity of heatwaves have been predicted to increase in the next few years, the combined multiple stressors effect may increase the vulnerability of mangrove organisms.


Subject(s)
Brachyura , Animals , Salinity , Water , Mexico
17.
Article in English | LILACS-Express | LILACS | ID: biblio-1574637

ABSTRACT

This study offers a counterpoint to the generalization of positive and linear effects resulting from challenge stressors in the workplace. The guiding objective was to verify whether social challenge stress impacts individuals' work engagement positively or negatively, according to the political skill degree available by professionals. We used moderation analysis and hierarchical regression to assess these relationships. The sample comes from civil servants of a Brazilian federal institution (N = 606). The results indicate that political skill moderates the relationship between social stress and engagement positively, except in cases where such skill is low, a situation in which the interaction becomes negative. The evidence also reveals that a positive curvilinear association better explains the association between social stress and work engagement. The findings suggest that the Challenge-Hindrance Stress Framework (CHF) has an application conditioned by the possible abilities that a given stressor demands to be evaluated as an obstacle or a challenge. We intended to extend the theory on stressors and contribute to the human resource management practice by elucidating conditions or portions of professionals in which the CHF does not apply or lacks contextualization.


Este estudio ofrece una contraparte a la generalización de los efectos positivos y lineales resultantes de los estresores desafiantes en el lugar de trabajo. El objetivo principal fue verificar si el estrés del desafío social afecta positiva o negativamente el engagement en el trabajo de las personas según el grado de habilidad política disponible en los profesionales. Se utilizaron el análisis de moderación y la regresión jerárquica para evaluar estas relaciones. La muestra consiste en funcionarios públicos de una institución federal brasileña (N= 606). Los resultados indican que la habilidad política modera positivamente la relación entre el estrés social y el engagement, excepto en los casos en que dicha habilidad es baja, momento en el cual la interacción se vuelve negativa. Además, la evidencia revela que una asociación curvilínea positiva explica mejor la relación entre el estrés social y el engagement. Los hallazgos sugieren que el Modelo de Estrés-Desafío-Obstáculo (MDO) tiene una aplicación condicionada por las habilidades requeridas para evaluar un determinado estresor como un obstáculo o un desafío. El objetivo era ampliar la teoría sobre los estresores y contribuir a la práctica de la gestión de recursos humanos aclarando las condiciones o situaciones en las que el MDO no se aplica o carece de contextualización.


Este estudo oferece um contraponto à generalização dos efeitos positivos e lineares resultantes de estressores desafiadores no ambiente de trabalho. O objetivo norteador foi verificar se o estresse do desafio social impacta positivamente ou negativamente o engajamento no trabalho dos indivíduos, de acordo com o grau de habilidade política disponível pelos profissionais. Usamos análise de moderação e regressão hierárquica para avaliar essas relações. A amostra é de servidores públicos de uma instituição federal brasileira (N = 606). Os resultados indicam que a habilidade política modera positivamente a relação entre estresse social e engajamento, exceto nos casos em que tal habilidade é baixa, situação em que a interação se torna negativa. As evidências revelam que uma associação curvilínea positiva explica melhor a associação entre estresse social e Engajamento no trabalho. Os achados sugerem que o Modelo de Estresse Desafio-Obstáculo (MDO) tem aplicação condicionada pelas possíveis habilidades que determinado estressor demanda para ser avaliado como obstáculo ou desafio. Pretendemos ampliar a teoria sobre estressores e contribuir para a prática da gestão de pessoas, elucidando condições ou parcelas de profissionais em que o MDO não se aplica ou carece de contextualização.

18.
Biotechnol Adv ; 70: 108303, 2024.
Article in English | MEDLINE | ID: mdl-38128850

ABSTRACT

Soil salinity is one of the most important abiotic factors that affects agricultural production worldwide. Because of saline stress, plants face physiological changes that have negative impacts on the various stages of their development, so the employment of plant growth-promoting bacteria (PGPB) is one effective means to reduce such toxic effects. Bacteria of the Bacillus genus are excellent PGPB and have been extensively studied, but what traits makes them so extraordinary to adapt and survive under harsh situations? In this work we review the Bacillus' innate abilities to survive in saline stressful soils, such as the production osmoprotectant compounds, antioxidant enzymes, exopolysaccharides, and the modification of their membrane lipids. Other survival abilities are also discussed, such as sporulation or a reduced growth state under the scope of a functional interaction in the rhizosphere. Thus, the most recent evidence shows that these saline adaptive activities are important in plant-associated bacteria to potentially protect, direct and indirect plant growth-stimulating activities. Additionally, recent advances on the mechanisms used by Bacillus spp. to improve the growth of plants under saline stress are addressed, including genomic and transcriptomic explorations. Finally, characterization and selection of Bacillus strains with efficient survival strategies are key factors in ameliorating saline problems in agricultural production.


Subject(s)
Bacillus , Bacillus/physiology , Soil , Plant Roots/microbiology , Bacteria/genetics , Antioxidants
19.
Salud ment ; Salud ment;46(6): 287-293, Nov.-Dec. 2023. tab
Article in English | LILACS-Express | LILACS | ID: biblio-1530381

ABSTRACT

Abstract Introduction The suspension of clinical practices in the nursing profession during COVID-19 generated a decrease in the students՚ abilities and skills which made them vulnerable to more frequent to clinical practice stressors and levels of anxiety. Objective To determine the relation between clinical practice stressors and anxiety levels in nursing students during COVID-19. Method A descriptive correlational study with convenience sampling was carried out in 169 students enrolled from third to eight semesters in a public university in the city of Saltillo, Coahuila. For the measurement of variables a sociodemographic data card, the KEZKAK Questionnaire in its Spanish version to measure the clinical practice stressors and the Beck Anxiety Inventory were used. Data collection was through a digital link during August-December 2021. Descriptive and inferential statistics were sued through SPSS V.26. Results 57.4% reported a medium level of stress and 62.7% a low level of anxiety; however, there are stressors from clinical practice that lead to increased anxiety. A statistically significant positive correlation was found between the study variables (r = .411, p<.001). Discussion and conclusion The challenges in clinical practice experienced during COVID-19 highlight that generations of future nursing professionals face a scenario that is the product of a post-pandemic era, so it is necessary to strengthen their knowledge and confidence to motivate them to feel safe within the hospital context.


Resumen Introducción La suspensión en las prácticas clínicas en la profesión de enfermería durante la COVID-19, generó en los estudiantes disminución de sus habilidades y destrezas que los hizo vulnerables a presentar con mayor frecuencia estresores de la práctica clínica y niveles de ansiedad. Objetivo Determinar la relación entre los estresores de la práctica clínica y los niveles de ansiedad en estudiantes de enfermería durante la COVID-19. Método Se realizó un estudio de tipo descriptivo correlacional con muestreo por conveniencia en 169 estudiantes de tercero a octavo semestre matriculados en una universidad pública de la ciudad de Saltillo Coahuila. Para la medición de variables se utilizó la cédula de datos sociodemográficos, el Cuestionario KEZKAK para medir los estresores de la práctica clínica y el Inventario de Ansiedad de Beck. La colecta de datos fue a través de un enlace digital durante agosto-diciembre 2021. Se utilizó estadística descriptiva e inferencial a través del SPSS V.26. Resultados El 57.4% refiere un nivel medio de estrés y el 62.7% un bajo nivel de ansiedad; sin embargo, existen estresores provenientes de la práctica clínica que propician el aumento de ansiedad. Se encontró una correlación positiva estadísticamente significativa entre las variables de estudio (r = .411, p<.001). Discusión y conclusión Los retos en la práctica clínica experimentados durante la COVID-19, resaltan que las generaciones de futuros profesionistas en enfermería se enfrentan a un panorama producto de una época post-pandemia, por lo que es necesario afianzar sus conocimientos y su confianza para motivarlos a sentirse seguros dentro del contexto hospitalario.

20.
AoB Plants ; 15(5): plad068, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37899976

ABSTRACT

In the temperate forests of Patagonia, Argentina, Nothofagus dombeyi, commonly known as Coihue, has shown sensitivity to intense drought events, leading to mortality. Studies have been conducted on Coihue decline and mortality using a variety of approaches, including the role of extreme heat waves and drought, pests and pathogens, particularly the fungus Huntiella decorticans. This work aimed to evaluate survival, vitality, necrosis extension and growth response of inoculated and non-inoculated Coihue seedlings from different provenances exposed to different soil moisture levels. To achieve this goal, 96 Coihue seedlings from 2 different provenances were assigned to 8 different experimental treatments. Treatments were composed of the presence or absence of H. decorticans and different soil moisture content conditions, dry, wet and the exposure to dry condition at different times of the experiment. Both dry conditions and H. decorticans had negative effects on the survival and growth rate of Coihue. The combination of both factors resulted in 100 % mortality, regardless of the plants' geographical provenances. Mortality began to be observed 3 months after pathogen inoculation, during the warmest month. Necrosis extension produced by the pathogen was similar for most of the inoculated treatments. The treatment under wet condition during the experiment but subjected to dry condition in the previous growing season presented lower necrosis extension (8.4 ±â€…3.2 %), than the other treatments. The radial increase was also affected by the treatments and geographical provenance, being those plants exposed to dry conditions which grew less (0.19 ±â€…0.21 mm). This study enhances our understanding of the plant-pathogen interaction. According to our results, Coihue may become more susceptible to mortality, when H. decorticans and water deficit conditions act synergistically.

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