Environmental Changes Research Articles

Biomethanisation of sewage sludge: Sonication pretreatment and monitoring of microbial communities

The improvement of mesophilic biomethanisation of recalcitrant sewage sludge derived from urban wastewater treatment through the application of a sonication pretreatment was evaluated in parallel in two pilot-scale anaerobic digesters (two biological replicates: reactors RA and RB). The valorisation process was monitored through a novel and holistic approach that related the biomethanisation yield, and its main batch operational parameters, with the abundance of archaeal and bacterial communities in the anaerobic inocula. Sonication allowed achieving a methane yield coefficient derived from sewage sludge of 240 ± 20 mLSTPCH4/g VS (volatile solids) at the load range of 0.8–4.0 g VS/L in both reactors. The process was more stable in reactor B, with a wider range of loads being allowed (up to 5.29 g VS/L). Monitoring the presence of Archaea in the mixing liquor revealed a variation in their abundance throughout the process which was directly related to the availability of organic matter and pH. Advanced metagenomic analysis showed the phylogenetic and functional diversity of the complex microbiome involved. While Bacteria were widely distributed in 35 phyla, Archaea fitted in only two. Euryarchaeota was the majoritarian archaeal phylum (99.5 %) and its more abundant families are linked to methanogenic metabolism. Functional analysis revealed several relevant metabolic pathways that followed similar trends in both reactors. “Methane metabolism” clearly diminished at the end of the process in concordance with the exhaust of methane generation, while “ABC transporters” or “two-component systems”, involved in bacterial survival to changing environments, followed the opposite pattern. This integrated approach could help to increase the methanogenic valorisation of sewage sludge.

Adaptive strategy optimization in game-theoretic paradigm using reinforcement learning

Parrondo's paradox refers to the counterintuitive phenomenon whereby two losing strategies, when alternated in a certain manner, can result in a winning outcome. Understanding the optimal sequence in Parrondo's games is of significant importance for maximizing profits in various contexts. However, the current predefined sequences may not adapt well to changing environments, limiting their potential for achieving the best performance. We posit that the optimal strategy that determines which game to play should be learnable through experience. In this Letter, we propose an efficient and robust approach that leverages Q learning to adaptively learn the optimal sequence in Parrondo's games. Through extensive simulations of coin-tossing games, we demonstrate that the learned switching strategy in Parrondo's games outperforms other predefined sequences in terms of profit. Furthermore, the experimental results show that our proposed method can be easily adjusted to adapt to different cases of capital-dependent games and history-dependent games. Published by the American Physical Society 2024

Relating gut microbiome composition and life history metrics for pronghorn (Antilocapra americana) in the Red Desert, Wyoming.

Host microbial communities (hereafter, the 'microbiome') are recognized as an important aspect of host health and are gaining attention as a useful biomarker to understand the ecology and demographics of wildlife populations. Several studies indicate that the microbiome may contribute to the adaptive capacity of animals to changing environments associated with increasing habitat fragmentation and rapid climate change. To this end, we investigated the gut microbiome of pronghorn (Antilocapra americana), an iconic species in an environment that is undergoing both climatic and anthropogenic change. The bacterial composition of the pronghorn gut microbiome has yet to be described in the literature, and thus our study provides important baseline information about this species. We used 16S rRNA amplicon sequencing of fecal samples to characterize the gut microbiome of pronghorn-a facultative sagebrush (Artemisia spp.) specialist in many regions where they occur in western North America. We collected fecal pellets from 159 captured female pronghorn from four herds in the Red Desert of Wyoming during winters of 2013 and 2014. We found small, but significant differences in diversity of the gut microbiome relative to study area, capture period, and body fat measurements. In addition, we found a difference in gut microbiome composition in pronghorn across two regions separated by Interstate 80. Results indicated that the fecal microbiome may be a potential biomarker for the spatial ecology of free-ranging ungulates. The core gut microbiome of these animals-including bacteria in the phyla Firmicutes (now Bacillota) and Bacteroidota-remained relatively stable across populations and biological metrics. These findings provide a baseline for the gut microbiome of pronghorn that could potentially be used as a target in monitoring health and population structure of pronghorn relative to habitat fragmentation, climate change, and management practices.

Managerial involvement and accountability of public sector accountants

EThis study aims to identify the involvement of accountants working in the public sector in managerial decisions and the accountability process, analyzing the relationship between these two types of involvement with role conflict, job satisfaction, and professional prestige. The study adopts a quantitative approach with a cross-sectional design using survey research techniques. The questionnaire was administered to a sample of 215 Brazilian public sector accountants. The study reveals that public sector accountants are more involved in operational decision-making activities and less involved in strategic decisions. They also show low involvement in activities related to managerial decisions and financial and performance accountability. Additionally, the study demonstrates a significant relationship between involvement, role conflict, and professional prestige. Thus, despite the changing environment for accountants and public accounting, respondents in the study are still relatively less involved in these processes. Furthermore, the more involved they are in their roles, the more susceptible these professionals are to role conflicts in their duties, although their perception of professional prestige increase.

People socialize ecological information about the environment but may forget their own experiences: a case study of local ecological knowledge about seed-dispersing animals

Local ecological knowledge (LEK) has been increasingly used in the search for efficient strategies to maintain biological diversity. However, considering the rapid environmental changes in ecosystems, such knowledge may have been lost between generations, affecting its potential application. In this study, we adopted the LEK of the potential dispersers of Caryocar coriaceum Wittm. (Caryocaraceae), an endangered plant species of socioeconomic and cultural importance from northeast Brazil, as a model. We evaluated whether there is intergenerational variation in the LEK about the abundance of Dasyprocta prymnolopha (the principal disperser of C. coriaceum) associated with the local practice of hunting. We collected LEK data from 39 hunter-gatherers aged 31 to 84 years, and camera traps were used during two annual C. coriaceum harvests to record its potential dispersers. Our results indicate that the LEK of the potential animal dispersers of C. coriaceum does not vary between generations; it is disseminated and shared between different generations. The strong interactions among people during the C. coriaceum harvest period facilitate the sharing of information about the potential dispersers of this species. Our results show that hunting D. prymnolopha does not depend on perceptions regarding the availability of this resource in the forest, which may be causing overexploitation. Therefore, local knowledge may need to be updated and connected to the recent and rapid environmental changes because people may believe that current environmental conditions are like those of the past. If this is the case, people may be less cooperative with conservation strategies because they are not aware of environmental changes, so measures to update knowledge about environmental conditions may be necessary to encourage effective participation in management and conservation plans.

Exogenous Sodium Nitroprusside Affects the Redox System of Wheat Roots Differentially Regulating the Activity of Antioxidant Enzymes under Short-Time Osmotic Stress

Nitric oxide (NO) is a multifunctional signalling molecule involved in the regulation of plant ontogenesis and adaptation to different adverse environmental factors, in particular to osmotic stress. Understanding NO-induced plant protection is important for the improvement of plant stress tolerance and crop productivity under global climate changes. The root system is crucial for plant survival in a changeable environment. Damages that it experiences under water deficit conditions during the initial developmental periods seriously affect the viability of the plants. This work was devoted to the comparative analysis of the pretreatment of wheat seedlings through the root system with NO donor sodium nitroprusside (SNP) for 24 h on various parameters of redox homeostasis under exposure to osmotic stress (PEG 6000, 12%) over 0.5–24 h. The active and exhausted solutions of SNP, termed as (SNP/+NO) and (SNP/−NO), respectively, were used in this work at a concentration of 2 × 10−4 M. Using biochemistry and light microscopy methods, it has been revealed that osmotic stress caused oxidative damages and the disruption of membrane cell structures in wheat roots. PEG exposure increased the production of superoxide (O2•−), hydrogen peroxide (H2O2), malondialdehyde (MDA), and the levels of electrolyte leakage (EL) and lipid peroxidation (LPO). Stress treatment enhanced the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), the excretion of proline, and the rate of cell death and inhibited their division. Pretreatment with (SNP/+NO) decreased PEG-induced root damages by differently regulating the antioxidant enzymes under stress conditions. Thus, (SNP/+NO) pretreatment led to SOD, APX, and CAT inhibition during the first 4 h of stress and stimulated their activity after 24 h of PEG exposure when compared to SNP-untreated or (SNP/−NO)-pretreated and stress-subjected plants. Osmotic stress triggered the intense excretion of proline by roots into the external medium. Pretreatment with (SNP/+NO) in contrast with (SNP/−NO) additionally increased stress-induced proline excretion. Our results indicate that NO is able to mitigate the destructive effects of osmotic stress on the roots of wheat seedlings. However, the mechanisms of NO protective action may be different at certain periods of stress exposure.

Risk Factors for Chronic Non-Communicable Diseases of Long-Haul Truck Drivers during the COVID-19 Pandemic: An Integrative Review

Long-haul truck drivers are responsible for transporting goods valued at millions of dollars of the world economy, and may have their health affected by living and working conditions. This study analyzed and synthesized scientific findings about risk factors for the development of chronic non-communicable diseases in long-haul truck drivers. An integrative literature review was conducted. We identified 23 studies that met the inclusion criteria and evaluated the health of 7363 drivers. The biological risk factors identified were age, gender, race/ethnicity, genetics, and comorbidities, and were considered to be non-modifiable for chronic diseases. The behavioral risks considered to be modifiable were sedentary lifestyle, smoking, alcohol consumption, overweight, diet, stress, anxiety, and unfavorable socioeconomic conditions. Environmental risks involved working conditions such as the following: number of working hours per day, week, and month; time away from home; risk of musculoskeletal injury; and opportunities for rest, hours of sleep, and access to health services. The results were presented in two categories: (1) biological, behavioral, and environmental risks, and (2) general recommendations to promote physical, cognitive, and emotional health. Macro-structural changes are needed to reorganize work and rest, improve access to health services to control modifiable risk factors, and to support behavioral and environmental changes to reduce chronic non-communicable diseases and deaths.

Uncertainty‐aware LiDAR‐based localization for outdoor mobile robots

AbstractAccurate and robust localization is essential for autonomous mobile robots. Map matching based on Light Detection and Ranging (LiDAR) sensors has been widely adopted to estimate the global location of robots. However, map‐matching performance can be degraded when the environment changes or when sufficient features are unavailable. Indiscriminately incorporating inaccurate map‐matching poses for localization can significantly decrease the reliability of pose estimation. This paper aims to develop a robust LiDAR‐based localization method based on map matching. We focus on determining appropriate weights that are computed from the uncertainty of map‐matching poses. The uncertainty of map‐matching poses is estimated by the probability distribution over the poses. We exploit the normal distribution transform map to derive the probability distribution. A factor graph is employed to combine the map‐matching pose, LiDAR‐inertial odometry, and global navigation satellite system information. Experimental verification was successfully conducted outdoors on the university campus in three different scenarios, each involving changing or dynamic environments. We compared the performance of the proposed method with three LiDAR‐based localization methods. The experimental results show that robust localization performances can be achieved even when map‐matching poses are inaccurate in various outdoor environments. The experimental video can be found at https://youtu.be/L6p8gwxn4ak.

Contrasting Phenological Patterns and Reproductive Strategies in Closely Related Monoecious Fig Tree Species

Understanding the ecological and evolutionary aspects of mutualistic interactions is essential for predicting species responses to environmental changes. This study aimed to investigate the phenological patterns and reproductive strategies in two closely related fig tree species, Ficus citrifolia and Ficus eximia. We monitored 99 F. citrifolia and 21 F. eximia trees weekly from January 2006 to April 2011 in an area close to the southern edge of the tropical region in Brazil. Our results revealed contrasting phenological patterns between the two species, with F. citrifolia displaying an annual flowering pattern (1.4 episodes per tree per year) and F. eximia a supra-annual pattern (0.5 episodes per tree per year). We also found significant differences in reproductive strategies, with F. eximia producing more pistillate flowers and, consequently, more seeds and pollinating wasps per fig than F. citrifolia, likely as an adaptation to overcome limitations of low population density by maximizing the gene flow. As the shorter-lived organism, the fig wasp was found to influence critical processes associated with the success and stability of mutualism, such as fig development and ripening. Our findings emphasize the importance of understanding the intricate interactions between mutualistic partners and their adaptive responses to environmental conditions in shaping fig tree populations’ reproductive strategies and genetic structure.

A network of acetyl phosphate-dependent modification modulates c-di-AMP homeostasis in Actinobacteria.

Cyclic purine nucleotides are important signal transduction molecules across all domains of life. 3',5'-cyclic di-adenosine monophosphate (c-di-AMP) has roles in both prokaryotes and eukaryotes, while the signals that adjust intracellular c-di-AMP and the molecular machinery enabling a network-wide homeostatic response remain largely unknown. Here, we present evidence for an acetyl phosphate (AcP)-governed network responsible for c-di-AMP homeostasis through two distinct substrates, the diadenylate cyclase DNA integrity scanning protein (DisA) and its newly identified transcriptional repressor, DasR. Correspondingly, we found that AcP-induced acetylation exerts these regulatory actions by disrupting protein multimerization, thus impairing c-di-AMP synthesis via K66 acetylation of DisA. Conversely, the transcriptional inhibition of disA was relieved during DasR acetylation at K78. These findings establish a pivotal physiological role for AcP as a mediator to balance c-di-AMP homeostasis. Further studies revealed that acetylated DisA and DasR undergo conformational changes that play crucial roles in differentiation. Considering the broad distribution of AcP-induced acetylation in response to environmental stress, as well as the high conservation of the identified key sites, we propose that this unique regulation of c-di-AMP homeostasis may constitute a fundamental property of central circuits in Actinobacteria and thus the global control of cellular physiology.IMPORTANCESince the identification of c-di-AMP is required for bacterial growth and cellular physiology, a major challenge is the cell signals and stimuli that feed into the decision-making process of c-di-AMP concentration and how that information is integrated into the regulatory pathways. Using the bacterium Saccharopolyspora erythraea as a model, we established that AcP-dependent acetylation of the diadenylate cyclase DisA and its newly identified transcriptional repressor DasR is involved in coordinating environmental and intracellular signals, which are crucial for c-di-AMP homeostasis. Specifically, DisA acetylated at K66 directly inactivates its diadenylate cyclase activity, hence the production of c-di-AMP, whereas DasR acetylation at K78 leads to increased disA expression and c-di-AMP levels. Thus, AcP represents an essential molecular switch in c-di-AMP maintenance, responding to environmental changes and possibly hampering efficient development. Therefore, AcP-mediated posttranslational processes constitute a network beyond the usual and well-characterized synthetase/hydrolase governing c-di-AMP homeostasis.

Carboxymethyl-Cellulose-Based Hydrogels Incorporated with Cellulose Nanocrystals Loaded with Vitamin D for Controlled Drug Delivery

Currently, the development of innovative materials for the treatment of various diseases is highly interesting and effective. Additionally, in recent years, environmental changes, including the search for a sustainable world, have become the main goal behind developing sustainable and suitable materials. In this context, this research produced innovative hydrogels that incorporate cellulose nanocrystals and nanofibres from underutilised fibres from a semiarid region of Brazil; the hydrogels were loaded with vitamin D to evaluate controlled drug release for the treatment of diverse diseases. Spectroscopic (FTIR, Raman, UV–VIS), X-ray diffraction, zeta potential and morphology (SEM, TEM) analyses were used to characterise these hydrogels. In addition, biocompatibility was assessed using a resazurin assay, and the in vitro kinetic accumulative release of vitamin D was measured. The results showed that nanocrystals and nanofibres changed the structure and crystallinity of the hydrogels. In addition, the chemical groups of the hydrogels were red- and blueshifted in the FTIR spectra when the nanocrystals, nanofibres and vitamin D were incorporated. Moreover, the nanocrystals and nanofibres were homogeneously spread into the hydrogel when vitamin D was loaded into the hydrogel matrix. Furthermore, the cytotoxicity was greater than 90%. Additionally, the in vitro accumulative kinetic data of vitamin D release were robust (close to 40 ng·mL−1), with equilibrium being reached in the first 30 min. These results confirm the potential of using these hydrogels as therapeutic biomaterials for diverse diseases and problems in humans, mainly in women, who are the most harmed by vitamin D deficiency.

A near-infrared-II light-response BODIPY-based conjugated microporous polymer for enhanced photocatalytic degradation of cationic dyes and H2O2 production.

A BODIPY-containing conjugated microporous polymer (CMP, LBFD-1) was modified with calixarene to develop a hydrophilic CMP (LBFD-2) with broader absorption extending to the near-infrared-II region. LBFD-2 exhibited an H2O2 production rate of 2.14 mmol g-1 h-1 in the air without any sacrificial agents. The removal efficiency (η) of LBFD-2 towards methylene blue and rhodamine B reached >99.5% within 20 and 40 min in light. LBFD-2 can withstand diverse environmental changes, showing excellent reusability and potential for practical applications in real-water systems.

Climate Change and Rye (Secale cereale L.) Production: Challenges, Opportunities and Adaptations

ABSTRACTThis comprehensive review examined the intricate relationship between climate change and rye (Secale cereale L.) production, focusing on the multifaceted challenges and opportunities posed by changing environmental conditions. Rye is a versatile cereal crop cultivated in temperate regions and is known for its resilience and adaptability to adverse growing conditions. However, as global temperatures and atmospheric CO2 concentrations rise, the effects of climate change on rye growth, yield and grain quality become increasingly apparent. In this review, we summarised the recent research findings on various aspects of rye production and quality under climate change, focusing on factors such as temperature (e.g., increasing temperature) resilience, and viability of rye production in the face of ongoing climate challenges, altered rainfall patterns (changing rainfall distributions with decreasing rainfall in the spring and early summer months as well as heavy rainfall events), biotic stress, agronomic practices and greenhouse gas emissions. Exploring the dynamic interplay among climate change, soil quality, biotic stressors and plant–microbe interactions reveals insights into the response of rye to environmental changes. These interactions shape the complex dynamics that influence the adaptation of rye to evolving environmental conditions. Implications for food security, agricultural sustainability and future research directions are also discussed, highlighting the urgent need for adaptive strategies to ensure the resilience and viability of rye production in the face of ongoing climate challenges.

Uncertainty‐aware LiDAR‐based localization for outdoor mobile robots

AbstractAccurate and robust localization is essential for autonomous mobile robots. Map matching based on Light Detection and Ranging (LiDAR) sensors has been widely adopted to estimate the global location of robots. However, map‐matching performance can be degraded when the environment changes or when sufficient features are unavailable. Indiscriminately incorporating inaccurate map‐matching poses for localization can significantly decrease the reliability of pose estimation. This paper aims to develop a robust LiDAR‐based localization method based on map matching. We focus on determining appropriate weights that are computed from the uncertainty of map‐matching poses. The uncertainty of map‐matching poses is estimated by the probability distribution over the poses. We exploit the normal distribution transform map to derive the probability distribution. A factor graph is employed to combine the map‐matching pose, LiDAR‐inertial odometry, and global navigation satellite system information. Experimental verification was successfully conducted outdoors on the university campus in three different scenarios, each involving changing or dynamic environments. We compared the performance of the proposed method with three LiDAR‐based localization methods. The experimental results show that robust localization performances can be achieved even when map‐matching poses are inaccurate in various outdoor environments. The experimental video can be found at https://youtu.be/L6p8gwxn4ak.

Seasonal metabolic dynamics of microeukaryotic plankton: a year-long metatranscriptomic study in a temperate sea.

Ecosystem composition and metabolic functions of temperate marine microeukaryote plankton are strongly influenced by seasonal dynamics. Although monitoring of species composition of microeukaryotes has expanded recently, few methods also contain seasonally resolved information on ecosystem functioning. We generated a year-long spatially resolved metatranscriptomic data set to assess seasonal dynamics of microeukaryote species and their associated metabolic functions in the Southern Bight of the North Sea. Our study underscores the potential of metatranscriptomics as a powerful tool for advancing our understanding of marine ecosystem functionality and resilience in response to environmental changes, emphasizing its potential in continuous marine ecosystem monitoring to enhance our ecological understanding of the ocean's eukaryotic microbiome.

Changes in plant diversity of European lowland forests: Increased homogenization and expansion of shade-tolerant trees

European lowland forests have undergone significant transformations over the past century due to increased canopy closure, eutrophication and plant invasions. The new millennium has brought plant invasions, alien fungal pathogens, and extreme weather conditions, all contributing to forest diebacks. However, the response of plant diversity remains poorly understood. We examined changes in understorey vegetation following a decade (2012–2021) of severe drought in four temperate lowland forest types (dominated by oaks, hornbeams, ashes, and willows) to understand how water availability, canopy openness, and alien fungal pathogens altered diversity in interaction with climate change. Following an exceptionally warm decade, the vegetation exhibited increased homogeneity, with denser shrub and herb layers, likely resulting from diminished tree canopy, particularly in hornbeam and ash forests. Homogenization was manifested by the colonization of plants with conservative life-history strategies (higher leaf dry matter content) to cope with increased drought. Consequently, communities with fewer species increased their species richness, while species-rich communities experienced impoverishment. Conversely, herbaceous species with higher specific leaf area were declining. Compositional changes were particularly prominent in hornbeam and oakwoods at the drier end of moisture gradient where the understorey became dominated by woody plants. Ashwoods were opening up due to ash dieback by fungal pathogens, causing replacement of wetland forbs by nitrophilous forbs and woody saplings. The overall number of species decreased in oakwoods but increased in hornbeam and ashwoods due to increased cover of grasses and shade-tolerant woody species, mostly Acer campestre. Conversely, willow understorey vegetation at the wetter end of the moisture gradient remained relatively stable. Our findings suggest shifts towards more homogeneous vegetation. Conservation plans for managing the remnants of species-rich lowland forests should consider the accelerated environmental changes linked to canopy alterations, biological invasions, and extreme climate events.

Pace of heavy metal pollution in the anthropogenically altered and industrialized Nakdong River Estuary, South Korea: Implications for the Anthropocene

Estuaries, vital coastal ecosystems, face growing threats from industrialization. To understand the pace of sedimentary changes and heavy metal pollution at the anthropogenically altered and industrialized Nakdong River Estuary in South Korea, we used sediment coring to reconstruct environmental change. Estuarine dam construction in 1934 shifted the sedimentary system from sand to mud, coinciding with a post-1930s mercury increase due to coal burning. Mercury concentrations in other South Korean regions surged in the 1970s, indicating proximity to emission sources matters. However, most heavy metal levels (Cu, Cd, Zn, Ag) sharply rose in the 1960s and 1970s with regional industrialization. Modern heavy metal concentrations doubled pre-industrial levels, underscoring human activities as the primary driver of Nakdong Estuary environmental changes. This emphasizes the need for a balanced approach to development and environmental preservation.

Formation of the junctions between lymph follicles in the Peyer's patches even before postweaning activation

Peyer’s patches (PPs), which contain an abundance of B and T cells, play a key role in inducing pivotal immune responses in the intestinal tract. PPs are defined as aggregated lymph follicles, which consist of multiple lymph follicles (LFs) that may interact with each other in a synergistic manner. LFs are thought to be spherical in shape; however, the characteristics of their structure are not fully understood. To elucidate changes in the structure of PPs as individuals grow, we generated serial 2D sections from entire PPs harvested from mice at 2, 4, and 10 weeks of age and performed a 3D analysis using a software, Amira. Although the number of LFs in PPs was not changed throughout the experiment, the volume and surface area of LFs increased significantly, indicating that LFs in PPs develop continuously by recruiting immune cells, even after weaning. In response to the dramatic changes in the intestinal environment after weaning, the development of germinal centers (GCs) in LFs was observed at 4 and 10 weeks (but not 2 weeks) of age. In addition, GCs gradually began to form away from the center of LFs and close to the muscle layer where export lymphatic vessels develop. Importantly, each LF was joined to the adjacent LF; this feature was observed even in preweaning nonactivated PPs. These results suggest that PPs may have a unique organization and structure that enhance immune functions, allowing cells in LFs to have free access to adjacent LFs and egress smoothly from PPs to the periphery upon stimulation after weaning.

Formation of the junctions between lymph follicles in the Peyer's patches even before postweaning activation

Peyer’s patches (PPs), which contain an abundance of B and T cells, play a key role in inducing pivotal immune responses in the intestinal tract. PPs are defined as aggregated lymph follicles, which consist of multiple lymph follicles (LFs) that may interact with each other in a synergistic manner. LFs are thought to be spherical in shape; however, the characteristics of their structure are not fully understood. To elucidate changes in the structure of PPs as individuals grow, we generated serial 2D sections from entire PPs harvested from mice at 2, 4, and 10 weeks of age and performed a 3D analysis using a software, Amira. Although the number of LFs in PPs was not changed throughout the experiment, the volume and surface area of LFs increased significantly, indicating that LFs in PPs develop continuously by recruiting immune cells, even after weaning. In response to the dramatic changes in the intestinal environment after weaning, the development of germinal centers (GCs) in LFs was observed at 4 and 10 weeks (but not 2 weeks) of age. In addition, GCs gradually began to form away from the center of LFs and close to the muscle layer where export lymphatic vessels develop. Importantly, each LF was joined to the adjacent LF; this feature was observed even in preweaning nonactivated PPs. These results suggest that PPs may have a unique organization and structure that enhance immune functions, allowing cells in LFs to have free access to adjacent LFs and egress smoothly from PPs to the periphery upon stimulation after weaning.

Dengue prevention and control measures in the state of Mato Grosso do Sul in the face os epidemics: a question of environmental education

Dengue is caused by viruses from the Flaviviridae family, from the Flavivirus genus, and has been identified as one of the main vector-borne diseases in the world. According to the epidemiological picture of dengue in Brazil, a wide distribution of Aedes aegypti was observed in all regions with the circulation of three main viral serotypes (DENV1, DENV2 and DENV3) and a great possibility of the introduction of the DENV4 serotype. Its transmission involves vectors of the Aedes genus, with Aedes aegypti being responsible for the urban cycle of the disease. It is an acute disease that can progress to remission of symptoms, or worsening of the case followed by death, a fact that highlights the importance of effective control measures. This work was carried out through retrospective analytical descriptive research with theoretical foundations carried out through a bibliographic review in the Scielo, Scopus, Bireme, Lilacs, MEDLINE and DATASUS databases with the objectives of identifying the number of Dengue cases that occurred in the period 2018 to 2023, the prevention and control measures implemented by the state and the occurrence of possible environmental and human health changes related to the use of these compounds.