Environmental Changes Research Articles

Digital platforms and SMEs’ performance: the moderating effect of intellectual capital and environmental dynamism

PurposeThis research aims to shed light on the linkage between digital platforms and small and medium-sized enterprises (SMEs) performance and consider the moderating effect of intellectual capital and environmental dynamism.Design/methodology/approachThis study applies a quantitative approach using a sample of primary data from 508 managers and directors of Vietnamese SMEs, using structural equation modeling (SEM).FindingsThe utilization of digital platforms by managers and directors has a positive impact on enhancing intellectual capital. However, under the influence of external environment changes, this trend may shift towards a negative direction. The ability to utilize digital platforms, whether directly or through information communication, positively affects the performance of businesses. Research has shown that the positive promotion of digital platform capability for intellectual capital factors such as human capital, organizational capital, and relational capital decreases when the external environment changes in the context of uncertain globalization.Originality/valueThis research focuses on SMEs operating in the technology and e-commerce sectors and it evidences that digital platforms are an effective baseline driver for promoting high-performing SMEs. By examining the connection between digital platform’s capability and IC and the significance of intellectual capital for SMEs’ performance, this study adds to the body of literature already available on the destructive regulatory potential of environmental dynamism. This study broadens the dynamic capabilities theory’s outcome audience and adds a new dimension to the impact of the digital platform’s capability (resource utilization) on the performance of SMEs.

Cyclical ‘Wetting’ Phenomenon in the Source Region of Yellow River under Long-term Trends from 1956 to 2022

Study regionthe source region of the Yellow River (SRYB) Study focusDue to environmental changes, the drying and wetting processes have become increasingly intricate, and it is uncertain whether the wetting phenomenon in the SRYB indicates a long-term trend or a temporary cyclic event. This study utilized monthly streamflow and precipitation records from 1956 to 2022 to calculate hydrological and meteorological-dryness/wetness, represented by the standardized streamflow and precipitation indices, respectively. This study used detrended, wavelet, and cross-wavelet methods to investigate dry-wet variability and identified the atmospheric circulation phenomena driving the dryness/wetness and cyclical changes in the region. New hydro-meteorological insights for the SRYB(i) The SRYB showed an overall fluctuating wetting trend, which intensified after 2000. (ii) There were notable oscillatory cycles at 3–5 years, 10–12 years, and approximately 20–25 years in both hydrological and meteorological dry-wet variability. (iii) Transitions from dry to wet conditions had no significant link to short-term cycles (e.g., 3–5 years), but were linked to decadal cycles (e.g., 20–25 years). (iv) Spring and winter precipitation and streamflow dominated the interannual dry-wet variability. (v) The ENSO, AMO, and PDO influenced short-term cyclic fluctuations, while the AO and PDO influenced decadal cyclic fluctuations. This indicates that the wetting trend follows a cyclic pattern, and the intensification since 2000 is consistent with a decadal cyclic signal.

Regulation of seed dormancy by histone post-translational modifications in the model plant Arabidopsis thaliana.

Plants synchronize their growth and development with environmental changes, which is critical for their survival. Among their life cycle transitions, seed germination is key for ensuring the survival and optimal growth of the next generation. However, even under favorable conditions, oftentimes germination can be blocked by seed dormancy, a regulatory multilayered checkpoint integrating internal and external signals. Intricate genetic and epigenetic mechanisms underlie seed dormancy establishment, maintenance, and release. In this review, we focus on recent advances that shed light on the complex mechanisms associated with physiological dormancy, prevalent in seed plants, with Arabidopsis thaliana serving as a model. Here, we summarize the role of multiple epigenetic regulators, but with a focus on histone modifications like acetylation and methylation, that finely tune dormancy responses and influence dormancy-associated gene expression. Understanding these mechanisms can lead to a better understanding of seed biology in general, as well as result in the identification of possible targets for breeding climate-resilient plants.

Exploring interspecific hybridization dynamics in artificial forests of Pinus brutia and P. halepensis: Implications for sustainable afforestation.

Interspecific hybridization increases genetic diversity, which is essential for coping with changing environments. Hybrid zones, occurring naturally in overlapping habitats of closely related species, can be artificially established during afforestation. The resulting interspecific hybridization may promote sustainability in artificial forests, particularly in regions facing degradation due to climate change. Currently, there is limited evidence of hybridization during regeneration of artificial forests. Here, we studied the frequency of Pinus brutia Ten. × P. halepensis Mill. hybridization in five planted forests in Israel in three stages of forest regeneration: seeds before dispersal, emerged seedlings and recruited seedlings at the end of the dry season. We found hybrids on P. brutia, but not on P. halepensis trees due to asynchronous cone production phenology. Using 94 single-nucleotide polymorphism (SNP) markers, we found hybrids at all stages, most of which were hybrids of advanced generations. The hybrid proportions increased from 4.7 ± 2.1 to 8.2 ± 1.4 and 21.6 ± 6.4 per cent, from seeds to emerged seedlings and to recruited seedlings stages, respectively. The increased hybrid ratio implies an advantage of hybrids over P. brutia during forest regeneration. To test this hypothesis, we measured seedling growth rate and morphological traits under controlled conditions and found that the hybrid seedlings exhibited selected traits of the two parental species, which likely contributed to the fitness and survival of the hybrids during the dry season. This study highlights the potential contribution of hybrids to sustainable-planted forests and contributes to the understanding of genetic changes that occur during the regeneration of artificial forests.

Regulatory effects of stress release from decellularized periosteum on proliferation, migration, and osteogenic differentiation of periosteum-derived cells.

Bone injury is often associated with tears in the periosteum and changes in the internal stress microenvironment of the periosteum. In this study, we investigated the biological effects of periosteal prestress release on periosteum-derived cells (PDCs) and the potential mechanisms of endogenous stem cell recruitment. Decellularized periosteum with natural extracellular matrix (ECM) components was obtained by a combination of physical, chemical, and enzymatic decellularization. The decellularized periosteum removed immunogenicity while retaining the natural network structure and composition of the ECM. The Young's modulus has no significant difference between the periosteum before and after decellularization. The extracted PDCs were further composited with the decellularized periosteum and subjected to 20% stress release. It was found that the proliferative capacity of PDCs seeded on decellularized periosteum was significantly enhanced 6 h after stress release of the periosteum. The cell culture supernatant obtained after periosteal prestress release was able to significantly promote the migration ability of PDCs within 24 h. Enzyme-linked immunosorbnent assay (ELISA) experiments showed that the expression of stroma-derived factor-1α (SDF-1α) and vascular endothelial growth factor (VEGF) in the supernatant increased significantly after 3 h and 12 h of stress release, respectively. Furthermore, periosteal stress release promoted the high expression of osteogenic markers osteocalcin (OCN), osteopontin (OPN), and collagen type I of PDCs. The change in stress environment caused by the release of periosteal prestress was sensed by integrin β1, a mechanoreceptor on the membrane of PDCs, which further stimulated the expression of YAP in the nucleus. These investigations provided a novel method to evaluate the importance of mechanical stimulation in periosteum, which is also of great significance for the design and fabrication of artificial periosteum with mechanical regulation function.

The language of nature in Murray Bowen's writings: how connection to nature informs Bowen theory and is essential to human survival

AbstractThe human is a product of nature, and the same emotional process at work in families is at work in the relationship of the human to nature. Current global concerns and environmental changes highlight the need for humans to revisit their relationships with the natural world. The purpose of this study was to survey Murray Bowen's professional letters to reify the constructs of Bowen theory. Qualitative methodology with a narrative research design was employed. A sample (N = 250) of Dr Bowen's professional letters from the archives dating from 1965 to 1990 was analysed. Results from this analysis reveal that Bowen's writings are grounded in the language of nature and that Bowen's thinking about the human species and the family offers ways in which to see the family and humans as part of a larger system. Relating more maturely to the natural world is essential for human survival.

Research on the application of automatic control theory in automatic driving technology

Autonomous driving technology has been widely used and studied in depth in recent years, and has become a hot field in the automotive industry. As one of the core methods to realize automatic driving, automatic control theory provides an important theoretical basis and practical guidance for automatic driving systems. This paper aims to explore the application of automatic control theory to autonomous driving and analyze its potential impact on improving driving safety, comfort and efficiency. This paper first introduces the basic principles and components of the autonomous driving system. Among them, automatic control theory plays an important role in decision-making and execution. Secondly, this paper discusses the specific application of automatic control theory in automatic driving. These include PID controller-based vehicle stability control, model predictive control (MPC) for path planning and trajectory tracking. These applications enable autonomous driving systems to respond in real time to environmental changes and maintain vehicle stability and safety. Finally, the paper discusses the challenges and future directions of automatic control theory in autonomous driving. Future research should focus on further improving the robustness and adaptability of automatic control algorithms to cope with complex driving scenarios and uncertainties. To sum up, automatic control theory plays an important role in automatic driving and has broad application prospects. Through continuous improvement and innovation, automatic control theory will make an important contribution to the realization of safer, more efficient, and more intelligent autonomous driving technology.

Holocene climate variability in Slovenia: A review

The Slovenian climate has undergone significant fluctuations, and an understanding of the past climate is necessary to improve models and recognise long-term patterns. The cryosphere environment, such as ice core samples, provides valuable palaeoclimate data. Palynology and dendroclimatology are also effective ways to study long-term changes in vegetation and reconstruct past climates using pollen and tree proxies. Sediment cores from various locations in Slovenia have been studied to understand past environmental changes. Borehole temperature profiles as well as historical records were also used to reconstruct past climate conditions. Studies have shown specific periods when climatic changes likely played a major role, but a complete timeline of the Slovenian climate throughout the Holocene has not yet been fully developed.

Fiscal Federalism in the Twenty-First Century

Fiscal federalism concerns the division of policy responsibilities among different levels of government. Many current economic and policy developments, such as globalization, environmental crises, and rising inequality, may not appear to be favorable to fiscal federalism, yet countries are further decentralizing their fiscal systems. We summarize the efficiency and equity aspects of fiscal decentralization, fiscal competition, fiscal externalities, and intergovernmental grants. The review introduces readers to theoretical reasons for/against a federalist structure. We discuss how federalism relates to classic problems in economics: externalities, inequality, spillovers, information, and aspects of political economy. Our review integrates both theory and empirics, while also focusing on the variety of federal systems in different countries, both developing and developed. We conclude by discussing how fiscal federalism is being shaped by economic, technological, and environmental changes, while discussing the effects of globalization, polarization, and global crises on the future of federal systems.

Fencing or balancing? An exploratory study of Australian and New Zealand exporters’ strategic responses during the US-China trade war

PurposeA key challenge for exporters and international marketing/purchasing managers is formulating strategic responses to deal with geopolitical disruptions during a trade war between superpowers. While past studies provide insightful analysis of the influence of changes in the institutional environment (regulatory pressures) on national and firm-level trade activities, they tend to ignore the association between inward (sourcing) or outward (export) international activities of firms during a trade war. In this study, we aim to explore various strategic options employed by third-party SME exporters in response to geopolitical disruptions, institutional pressures and constraints during a trade war.Design/methodology/approachWe adopted a qualitative methodology and applied a hermeneutical approach in collecting, analysing and theorising interview findings. We conducted interviews with 15 owners or senior managers from 12 Australian and New Zealand exporters that exported or sourced significantly from at least one party of the trade war, the USA or China, between 2018 and 2020.FindingsOur study developed a typology of fencing vs. balancing for explaining third-party SME exporters’ response strategies in terms of export market and international sourcing locations during a trade war. Fencing strategy centres on location choice decisions based on a fence or a secure buffer zone. Balancing strategy focuses on leveraging opportunities outside the conflict zone, i.e. third-party countries. Our study finds that exporters’ location choice decisions are influenced by a number of institutional factors during the trade war.Research limitations/implicationsFirstly, our study examined only the early phase of the trade war under the “Trump” era. Future research may consider a longitudinal study design that examines exporters’ responses to global political uncertainty over a longer term. Secondly, we chose Australia and New Zealand as the focal context of this study. Future research could investigate exporters from other third-party countries that have different institutional conditions during the US-China trade war.Practical implicationsFirstly, an exporting firm should monitor and assess closely the wider changes in international relations between their home country’s major security partner and major trading partner, and the impact of these changes on the political risks of operating in international locations. Secondly, as the trade war intensifies, the fencing option needs to be given a greater weight than the balancing option in the strategic decision making of an exporter from a third-party country. Lastly, we encourage marketers and managers to reflect on and differentiate short-term and long-term benefits in strategic market-sourcing location decisions.Originality/valueOur study makes a pioneering effort to theorise the linkages between institutional factors and the combined evaluation of export market selection and sourcing location selection choices under global political uncertainty based on the institution-based view. We present a conceptual framework highlighting the importance of institutional avoidance, embeddedness, comparative institutional advantages and multiple institutional logics for SME exporters’ international location selections during the trade war. Furthermore, we combine these institutional factors into two overarching constructs namely institutional buffer and institutional pluralism.

Guidelines for setting up low-vision and rehabilitation services in India.

Low vision and blindness are increasing public health issues impacting individuals' quality of life. During clinical low-vision services, vision rehabilitation is crucial for enhancing daily living skills and improving life quality. Low-vision and rehabilitation (LVR) services encompass comprehensive measures that aid visually disabled individuals in restoring function, autonomy, and social participation. Such holistic management requires a multidisciplinary approach, facilitating adaptation to environmental and sociocultural changes. However, the lack of awareness about the principles and practices of LVR services poses a major hindrance to setting up such a special clinic in the eye hospital. This article is about a consensus statement on the guidelines for establishing LVR services focusing on basic requirements, especially in low-resource countries. The present recommendation to set up an LVR clinic was made after group discussions and debates among various experts and stakeholders during the National Workshop on Strengthening Low-Vision and Rehabilitation Services organized at Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi. The event was participated by many ophthalmologists and optometrists coming from across the country. The recommendations required at the tertiary level are outlined under the four headings: Human resources and training: two ophthalmologists, that is, a low vision specialist or a well-experienced in low vision and one who has received one-week orientation and training, one optometrist, one rehabilitation supervisor, and two rehabilitation assistants; Assessment equipment: basic screening and diagnostic; Assistive devices for low vision, including, digital and non-digital; Assistive devices for rehabilitation, and methods for records maintenance. The institution may not follow strictly the present guidelines but will provide an idea on LVR services initiation.

Effects of environmental humidity on the gap of mortise-tenon joints: experimental and numerical investigations

Mortise-tenon (MT) joints play a vital role in the lateral deformability and seismic performance of traditional timber structures. However, moisture exposure can cause shrinkage-induced gaps and then affect the durability of MT joints. Limited knowledge exists on the humidity response of MT joints. To investigate the effect of environmental humidity on the gaps between mortise and tenon, multiple measurements of moisture content (MC) and shrinkage deformation were conducted on straight MT joints that were subjected to humidity variations. Different ambient conditions and exposure levels were taken into account. Three-dimensional numerical models were established to simulate the humidity response of MT joints. Model validation was then performed by comparing the simulation and experimental results in terms of moisture distribution and gaps. On this basis, quantitative analysis was made to reveal the development mechanism and main influence factors of moisture-induced gaps. Results show that straight MT joints are vulnerable to environmental humidity changes. The observed gap is estimated to cause a decrease of up to 23.1% in the initial elastic stiffness. Although only contributed by the shrinkage deformation of tenons, the vertical gap is theoretically larger than the horizontal one which is attributed to a combination of both mortise and tenon. A clear linear relationship is found between the vertical gaps and the MC decrease, with the product of the radial shrinkage coefficient and tenon height as the theoretical ratio. Controlling the moisture exposure is considered the most effective way to reduce moisture-induced gaps in MT joints.

Silicon Microring Resonator Biosensor for Detection of Nucleocapsid Protein of SARS-CoV-2

A high-sensitivity silicon microring (Si MRR) optical biosensor for detecting the nucleocapsid protein of SARS-CoV-2 is proposed and demonstrated. In the proposed biosensor, the surface of a Si MRR waveguide is modified with antibodies, and the target protein is detected by measuring a resonant wavelength shift of the MRR caused by the selective adsorption of the protein to the surface of the waveguide. A Si MRR is fabricated on a silicon-on-insulator substrate using a CMOS-compatible fabrication process. The quality factor of the MRR is approximately 20,000. The resonant wavelength shift of the MRR and the detection limit for the environmental refractive index change are evaluated to be 89 nm/refractive index unit (RIU) and 10−4 RIU, respectively. The sensing characteristics are examined using a polydimethylsiloxane flow channel after the surface of the Si MRR waveguide is modified with the IgG antibodies through the Si-tagged protein. First, the selective detection of the protein by the MRR sensor is experimentally demonstrated by the detection of bovine serum albumin and human serum albumin. Next, various concentrations of nucleocapsid protein solutions are measured by the MRR, in which the waveguide surface is modified with the IgG antibodies through the Si-tagged protein. Although the experimental results are very preliminary, they show that the proposed sensor has a potential nucleocapsid sensitivity in the order of 10 pg/mL, which is comparable to the sensitivity of current antigen tests. The detection time is less than 10 min, which is much shorter than those of other antigen tests.

Integrated monitoring and modeling to disentangle the complex spatio-temporal dynamics of urbanized streams under drought stress

We have a poor understanding of how urban drainage and other engineered components interact with more natural hydrological processes in green and blue spaces to generate stream flow. This limits the scientific evidence base for predicting and mitigating the effects of future development of the built environment and climate change on urban water resources and their ecosystem services. Here, we synthesize > 20 years of environmental monitoring data to better understand the hydrological function of the 109-km2 Wuhle catchment, an important tributary of the river Spree in Berlin, Germany. More than half (56%) of the catchment is urbanized, leading to substantial flow path alterations. Young water from storm runoff and rapid subsurface flow provided around 20% of stream flow. However, most of it was generated by older groundwater (several years old), mainly recharged through the rural headwaters and non-urban green spaces. Recent drought years since 2018 showed that this base flow component has reduced in response to decreased recharge, causing deterioration in water quality and sections of the stream network to dry out. Attempts to integrate the understanding of engineered and natural processes in a traditional rainfall-runoff model were only partly successful due to uncertainties over the catchment area, effects of sustainable urban drainage, adjacent groundwater pumping, and limited conceptualization of groundwater storage dynamics. The study highlights the need for more extensive and coordinated monitoring and data collection in complex urban catchments and the use of these data in more advanced models of urban hydrology to enhance management.

Late Triassic to Early Jurassic carbon isotope chemostratigraphy and organo-facies evolution in a distal to proximal transect of the North German Basin

AbstractThroughout the Latest Triassic and the Early Jurassic, major changes in paleogeography, climate and eustatic sea-level impacted on the development of shelf depositional environments. Secular trends in environmental conditions were punctuated by transient perturbations that occurred in relation to large-scale volcanic events, such as the emplacement of the Central Atlantic Magmatic Province at the Triassic/Jurassic boundary and the Karoo–Ferrar Large Igneous Province in the early Toarcian. We here present bulk organic (HAWK programmed pyrolysis) and organic carbon isotope (δ13Corg) data for three drill cores recovering Latest Triassic and Early Jurassic strata (Rhaetian to Toarcian). Study sites are located in the northeastern part of the Central European Epicontinental Sea and were positioned along a distal–proximal transect of the North German Basin. This allows discussing the differential response of depositional settings and organo-facies toward secular and transient environmental change. Biostratigraphically anchored trends in δ13Corg values allow the precise correlation along the transect, as well as with distant sites. At all North German locations, diagnostic secular trends in δ13Corg are punctuated by transient negative carbon isotope excursions, reflecting perturbations of the global carbon cycle at the Triassic/Jurassic boundary and in the early Toarcian. Stratigraphic gaps occurred during sea-level lowstands and are most pronounced at shallow proximal sites. Programmed pyrolysis data indicate spatiotemporal organo-facies trends that on a temporal scale occurred in response to sea-level and climate trends, while spatial patterns were governed by basin morphology and paleobathymetry. Substantial marine organic matter accumulations occurred at high sea level during the Toarcian only, and were most continuous at distal sites. Graphical Abstract

Small but connected islands can maintain populations and genetic diversity under climate change

In response to the striking effects of environmental change, conservation strategies often include the identification of conservation areas that can effectively maintain vulnerable species. Consequently, identifying system‐specific conditions that maintain the demographic and genetic viability of species of conservation concern is essential. Connectivity plays a critical role in the persistence of populations. Islands have been model systems to understand connectivity and metapopulation processes and have emerged as particularly favorable targets for conservation. While islands can be isolated from mainland disturbances, it is unknown what degree of isolation is necessary to avoid unfavorable changes but remain sufficiently connected to maintain population viability. To test this question, we explored connectivity within the Apostle Islands, an archipelago of 22 islands within Lake Superior, by comparing historical and contemporary trends in ice bridge connectivity and by simulating the effect of reduced connectivity within this system. We developed a demographically informed individual‐based model to explicitly test the role of connectivity to influence the persistence and genetic diversity of American marten Martes americana, a forest carnivore at risk across its southern range boundary. We found that genetic diversity was resilient to moderate changes in ice cover, but a complete loss of connectivity resulted in rapid genetic erosion. Despite genetic erosion, populations persisted as long as nominal connectivity occurred between islands. Our work suggests that connectivity will decline, but martens would be resilient to moderate changes and, in the short term, the Apostle Islands can act as a refuge along this species' southern range boundary. Identifying thresholds in connectivity that maintain populations but allow for isolation from disturbance will be necessary to identify suitable areas for species conservation across space and time.

Rangelands and Pastoralism in Globalized Economies: Policy Paralysis and Legal Requisites

Growing quest for globalization and expanding economies have resulted into fragmentation, enclosure, grabbing, militarization and devastation of rangelands. Grasslands – covering 70% of the global agricultural area – are the basis for livestock production. In most of the countries, governments have little recognition of communal tenures of agro-pastoralists. Consequently, both pastoralists and rangeland ecosystems have suffered a grim fate. On the contrary, the subsistence pastoralism is an established sustainable strategy of livelihood and ecosystem conservation in the rangelands. Unfortunately, some of the most nutritive foods and other sustainable products of nomadic pastoralists have not desirably been priced in modern markets. With the demonstrated cases exhibiting the nomadic pastoralists, such as Hutsul shepherd communities of Ukraine, as most sustainable societies on planet Earth, there is urgent need for reshaping the popular paradigm and State policies on rangeland commons. In isolation of pastoralist people, the rangelands cannot truly be conserved or protected. To begin with, the resilience of pastoralists to the changing environments and their (unique) rangeland management can first be pondered. Accordingly, the policy and legal frameworks of States need to be reoriented and revised. In particular, Eurasian countries should review their laws and policies on rangeland sustainability and pastoral grazing.

A computational neural model that incorporates both intrinsic dynamics and sensory feedback in the Aplysia feeding network.

Studying the nervous system underlying animal motor control can shed light on how animals can adapt flexibly to a changing environment. We focus on the neural basis of feeding control in Aplysia californica. Using the Synthetic Nervous System framework, we developed a model of Aplysia feeding neural circuitry that balances neurophysiological plausibility and computational complexity. The circuitry includes neurons, synapses, and feedback pathways identified in existing literature. We organized the neurons into three layers and five subnetworks according to their functional roles. Simulation results demonstrate that the circuitry model can capture the intrinsic dynamics at neuronal and network levels. When combined with a simplified peripheral biomechanical model, it is sufficient to mediate three animal-like feeding behaviors (biting, swallowing, and rejection). The kinematic, dynamic, and neural responses of the model also share similar features with animal data. These results emphasize the functional roles of sensory feedback during feeding.

CORTICOSTEROID-INDUCED EXPRESSION OF MICROBIAL VIRULENCE CAN ENHANCE THE DEVELOPMENT OF HOST INFECTIOUS DISEASE

Corticosteroids regulate a number of physiological processes and are synthetic analogs of the natural steroid hormones produced by the adrenal cortex. As drugs, corticosteroids are non-inflammatory and are used for the treatment of plethora of conditions which include arthritis, kidney, skin, lungs or thyroid disorders, for the treatment and relief of symptoms of allergies and symptoms of some gastrointestinal disorders. In addition, glucocorticoids can regulate the effects of inflammatory disorders, including sepsis, autoimmune diseases, and allergies. These conditions are potentially fatal. Consequently, this drug class is among the most commonly prescribed globally. One representative of corticosteroid class of drugs is dexamethasone which is used to treat allergies, adrenal problems, arthritis, asthma, diseases of blood or bone marrow, inflammation, kidney diseases, different types of skin conditions, and episodes of multiple sclerosis. Virulence factors help bacteria colonize the host at the level of the cell. In their nature, these factors are secretory, associated with the membrane or present in the cytosol. Secretory factors allow bacterium to circumvent the host immune response, while membrane factors aid bacterium in adhesion to the host cell. Finally, cytosol factors help bacteria adapt metabolically, physiologically, and morphologically to their changing environment. One such factor is aspartyl proteinase, a protein that degrades other proteins and is a virulence factor in many pathogens playing a role in the host invasion process. Another important virulence factor is the ability to form biofilms, which can render bacteria resistant to antimicrobials. Despite the widespread use of corticosteroids, including dexamethasone, little is known about their possible influence on the expression of virulence factors such as aspartyl proteinase. If such a connection is to exist the use of corticosteroids could elicit pathogenesis in certain microbes. In the here-presented study we wanted to investigate the effects of dexamethasone on the growth, expression of aspartyl proteinase and biofilm formation in three E. coli strains that were previously isolated from patients suffering from urinary tract infection. To this aim, we amended the growth media with 0.5 mg/mL dexamethasone. Bacterial growth was measured over the period of 24 hours and the effect of dexamethasone was established at different time points. Administration of 0.5 mg/mL glucocorticoid drug dexamethasone did not significantly affect bacterial growth. However, it resulted in an increase in concentration of secreted E. coli virulence factor aspartyl proteinase, which increased up to 2.6-fold for some E. coli strains. In addition, we noted the increased biofilm formation in to three out of four studied strains. This study indicates dexamethasone as a possible trigger molecule for the expression of virulence factor aspartyl proteinase in E. coli.

Using image segmentation models to analyse high-resolution earth observation data: new tools to monitor disease risks in changing environments.

In the near future, the incidence of mosquito-borne diseases may expand to new sites due to changes in temperature and rainfall patterns caused by climate change. Therefore, there is a need to use recent technological advances to improve vector surveillance methodologies. Unoccupied Aerial Vehicles (UAVs), often called drones, have been used to collect high-resolution imagery to map detailed information on mosquito habitats and direct control measures to specific areas. Supervised classification approaches have been largely used to automatically detect vector habitats. However, manual data labelling for model training limits their use for rapid responses. Open-source foundation models such as the Meta AI Segment Anything Model (SAM) can facilitate the manual digitalization of high-resolution images. This pre-trained model can assist in extracting features of interest in a diverse range of images. Here, we evaluated the performance of SAM through the Samgeo package, a Python-based wrapper for geospatial data, as it has not been applied to analyse remote sensing images for epidemiological studies. We tested the identification of two land cover classes of interest: water bodies and human settlements, using different UAV acquired imagery across five malaria-endemic areas in Africa, South America, and Southeast Asia. We employed manually placed point prompts and text prompts associated with specific classes of interest to guide the image segmentation and assessed the performance in the different geographic contexts. An average Dice coefficient value of 0.67 was obtained for buildings segmentation and 0.73 for water bodies using point prompts. Regarding the use of text prompts, the highest Dice coefficient value reached 0.72 for buildings and 0.70 for water bodies. Nevertheless, the performance was closely dependent on each object, landscape characteristics and selected words, resulting in varying performance. Recent models such as SAM can potentially assist manual digitalization of imagery by vector control programs, quickly identifying key features when surveying an area of interest. However, accurate segmentation still requires user-provided manual prompts and corrections to obtain precise segmentation. Further evaluations are necessary, especially for applications in rural areas.