Changes In Distribution Patterns Research Articles

Optimizing CO2 Hydrate Sequestration in Subsea Sediments through Cold Seawater Pre-Injection

Carbon sequestration technology offers a solution to mitigate excessive carbon dioxide emissions and sustainable development in the future. This study proposes a method for subsea carbon sequestration through the injection of cold seawater to promote CO2 hydrate formation. Using a self-developed simulator, we modeled and calculated the long-term sequestration process. The study focuses on analyzing the thermal regulation of the seabed following cold seawater injection, the multiphysical field evolution during CO2 injection and long-term sequestration, and the impact of seawater injection volumes on sequestration outcomes. The feasibility and leakage risks of this method were evaluated on a 100,000-year timescale. Results indicate that the injection of cold seawater significantly improves the pressure–temperature conditions of subsea sediments, facilitating early hydrate formation and markedly increasing the initial CO2 hydrate formation rate. Consequently, the distribution pattern of hydrate saturation changes, forming a double-layer hydrate shell. Over the long term, while cold seawater injection does not significantly reduce CO2 leakage, it does increase the safety margin between the hydrate layer and the seabed, enhancing the safety coefficient for long-term CO2 hydrate sequestration. Through detailed analysis of the behavior of CO2 components during sequestration, this study provides new theoretical insights into subsea CO2 hydrate storage.

Analysis of the Distribution Pattern of Phenacoccus manihoti in China under Climate Change Based on the Biomod2 Model.

The changing global climate has significantly impacted the spread of plant pests. The cassava mealybug (Phenacoccus manihoti) is among the most dangerous quarantine pests affecting cassavas worldwide, causing substantial losses in agricultural production and food security across several regions. Although China is currently free of the cassava mealybug, its proximity to affected countries and extensive trade with these regions necessitate a detailed understanding of the pest's distribution pattern and dynamic ecological niche changes. Using the Biomod2 model, we selected two historical climate scenarios and two future climate scenarios (SSP1-2.6 and SSP5-8.5) to investigate the distribution patterns, potential habitats, distribution centers, and dynamic ecological niches of cassava mealybugs in China. Key environmental variables influencing the distribution were identified, including bio4, bio8, bio12, bio18, and bio19. The potential habitat of cassava mealybugs is mainly located in several provinces in southern China. In the future, the suitable habitat is projected to expand slightly under the influence of climate change, maintaining the overall trend, but the distribution center of suitable areas will shift northward. Dynamic ecological niche prediction results indicate the potential for further expansion; however, the ecological niches may be unequal and dissimilar in the invaded areas. The predictions could serve as a valuable reference for early warning systems and management strategies to control the introduction of cassava mealybugs.

Low-oxygen-induced root bending is altered by phytoglobin1 through mediation of ethylene response factors (ERFs) and auxin signaling.

phytoglobin1 positively regulates root bending in hypoxic Arabidopsis roots through regulation of ethylene response factors and auxin transport. Hypoxia-induced root bending is known to be mediated by the redundant activity of the group VII ethylene response factors (ERFVII) RAP2.12 and HRE2, causing changes in polar auxin transport (PAT). Here, we show that phytoglobin1 (Pgb1), implicated in hypoxic adaptation through scavenging of nitric oxide (NO), can alter root direction under low oxygen. Hypoxia-induced bending is exaggerated in roots over-expressing Pgb1 and attenuated in those where the gene is suppressed. These effects were attributed to Pgb1 repressing both RAP2.12 and HRE2. Expression, immunological and genetic data place Pgb1 upstream of RAP2.12 and HRE2 in the regulation of root bending in oxygen-limiting environments. The attenuation of slanting in Pgb1-suppressing roots was associated with depletion of auxin activity at the root tip because of depression in PAT, while exaggeration of root bending in Pgb1-over-expressing roots with the retention of auxin activity. Changes in PIN2 distribution patterns, suggestive of redirection of auxin movement during hypoxia, might contribute to the differential root bending responses of the transgenic lines. In the end, Pgb1, by regulating NO levels, controls the expression of 2 ERFVIIs which, in a cascade, modulate PAT and, therefore, root bending.

Longitudinal distribution of fish fauna and characteristics of indicator species in the East Seto Inland Ecological Region within the Japanese Archipelago

Understanding biota distribution patterns is essential for ecosystem conservation and restoration. In addition to biogeography, the distribution patterns of aquatic organisms that inhabit rivers vary longitudinally along river networks. Although longitudinal changes in distribution patterns in aquatic organisms along river networks have been studied in single river basins, it is crucial to understand these patterns at a regional ecological scale for broad-scale ecosystem conservation. This study aimed to elucidate the longitudinal distribution patterns of fish fauna and their correlation with environmental factors in several watersheds within the East Setouchi Ecological Region, renowned for its rich freshwater fish diversity in the Japanese archipelago. Data were obtained for 118 species across 10 watersheds and 85 sites, and the surveyed sites were classified into four longitudinal groups based on the similarity of the fish fauna. The lowest group comprised river estuaries, abundant in brackish-water fish, comprising primarily Gobiidae species. In lower watershed areas with low agricultural land and forest cover but high urbanization, all fish species selected as indicators were non-native. Upstream areas with a high percentage of agricultural land featured a mix of native Cyprinidae and non-native species such as Micropterus salmoides and Rhodeus ocellatus ocellatus. The most upstream groups, marked by significantly greater elevations and bed slopes, exclusively comprised native species as indicator species. Analyzing the longitudinal distribution patterns of fish fauna at multiple sites within the same ecological region enabled us to choose endemic fish species as indicators and identify important species for conservation. Additionally, the selection of sites characterized by significant urbanization and strong anthropogenic influences, along with the selection of non-native species as indicators, underscores the urgency of conserving native organisms in these areas, calling for continuous monitoring.

Impacts of climate change on the geographic distribution patterns of pelagic fishes in the Southern Ocean

Pelagic fishes are a key trophic component of the Southern Ocean ecosystem. However, understanding the spatial and temporal changes in geographic distribution patterns of pelagic fishes in the context of climate change remains limited. This research applied the MaxEnt model to project the distributions of current and future (2100s) suitable habitats for ten major pelagic fish species in the Southern Ocean (two scenarios: RCP4.5 and RCP8.5). Results suggested that the current spatial distribution of pelagic fishes is significantly correlated with their realized niche and that global warming will lead to significant changes in the spatial distribution of pelagic fishes in the Southern Ocean. Model predictions showed that eight out of ten pelagic fish species are likely to face a significant reduction in their ranges of suitable habitats under the RCP8.5 scenario by the 2100s. Except for the Bathylagus antarcticus, all of the other nine species were predicted to migrate toward South Pole by the 2100s. In addition, the community composition of pelagic fishes also may change significantly, mostly because of species loss. The results of this study clarify the impact of climate change on pelagic fishes in the Southern Ocean, and provide theoretical support for sustainable management and conservation efforts of these pelagic fishes.

Predicting the distribution pattern changes of dye plant habitats caused by climate change

Climate change has accelerated the habitat loss and fragmentation of wildlife. Dye plants of “Fengxiang dyeing” are important indigenous natural resources for traditional printing and dyeing craft in southwest China, is of practical and cultural importance for dozens of ethnic minorities. However, lack of the spatial distribution information of these plants has hampered holistic and efficient conservation management measures. We analyzed the potentially suitable areas of four dye plants (Liquidambar formosana, Strobilanthes cusia, Persicaria tinctoria and Indigofera tinctoria) necessary for “Fengxiang dyeing” based on their geographical distribution sites under different climatic situations using the maximum entropy (MaxEnt) model. The results showed that temperature, precipitation and elevation were the most important factors affecting the suitable geographical areas of the four dye plants. Under the current climate conditions, the overlapping suitable habitat areas of the four plants were mainly in the four southern provinces of China, including Guizhou, Guangxi, Guangdong and Hainan. L. formosana was used as the base plant for combination with the other three plants under the two future climate scenarios (SSP126 and SSP585), and the overlapping suitable habitat areas of the obtained seven combination patterns were considered suitable for potential craft development. Five patterns showed an increase, while two patterns showed a decreasing trend with the increasing carbon emission. The prediction results showed that the overlapping suitable habitat center of the four plants will gradually move to the northeast, indicating that the overlapping suitable habitat area and craft distribution area will be changed. These results provide the basis for understanding the spatial distribution pattern changes of dye plants caused by climate change and establishing measures for protecting and developing printing and dyeing craft.

Morphological Development and DNA Barcoding Identification of Pholis fangi Larvae and Juveniles in the Yellow Sea

Pholis fangi is a small, bottom-dwelling fish species endemic to the Yellow Sea and Bohai Sea in China. While previous research has focused on its population biology and molecular structure, little is known about the early developmental stages of this species. In this study, larval and juvenile P. fangi specimens were collected from the Sheyang Sea Area, Jiangsu Province, in 2017. Morphological features were examined using microscopy, and DNA barcoding was conducted to confirm species identification. The research documented detailed changes in yolk sac, fin development, and melanophore distribution patterns across larval and juvenile stages of P. fangi. Comparative analysis with other Pholis species revealed that melanophore distribution is a key distinguishing characteristic, allowing effective differentiation between larval and juvenile stages, as well as between Pholis species. This study provides valuable insights into the early life history of P. fangi, contributing to a better understanding of the genus Pholis. The findings demonstrate the utility of combining traditional morphological observation and molecular techniques for accurate species identification, particularly during the critical larval and juvenile developmental phases.

Multi-scale population analysis unit construction method considering scene feature variability and long/short-term patterns in spatiotemporal population activities

ABSTRACT Differences in the spatial scale and component elements of urban scenes affect the analysis of spatiotemporal changes in population distribution (PD) patterns. Fixed scales and geometric forms constrained previous analyses of PD and spatiotemporal changes, which neglected the realistic characteristics of urban scenarios. These limitations hinder the ability to capture the diversity and spatiotemporal representation of PD patterns across multiple spatial scales. This study developed a multi-spatial scale population analysis unit (PAU) construction method considering the scenario heterogeneity and long/short-term patterns of spatiotemporal population changes (PC). Initially, we decompose the multi-scale changes in population time series patterns and their relationships with scene features along the temporal dimension to analyze the primary and secondary factors. Starting from the temporal characteristics of the PD and PC, we established a validation and correction method for the factors. Finally, combined with a multi-feature clustering method, a multi-scale PAU construction method driven by scene feature factors is proposed. Experiments were conducted at different spatial scales in both routine and emergent scenarios. The results indicated that this method can help to obtain more homogeneous analysis regions and enhance the stability and phase pattern representations of changes in PDs, thereby improving the interpretability of analytical results.

Sustainable Energy Consumption Analysis through Data Driven Insights

Energy is the backbone of our society, supporting our daily activities and driving progress. It plays a crucial role in shaping our modern way of life. The future of global energy consumption is influenced by many factors, including demographics, economic dynamics, technological developments, political actions, environmental demands and geopolitical considerations. As the world's population continues to grow and urbanize, the demand for energy is increasing. At the same time, rapid technological innovations are shaping the energy landscape and changing production, distribution and consumption patterns. In the midst of this development, it is very important to optimize energy consumption, accurately anticipate needs, curb climate change, limit emissions of greenhouse gasses, fight against pollution and promote sustainability. This study includes an in-depth analysis of historical consumption trends, assessing the multiple benefits of renewable energy integration, estimating carbon emissions, formulating practical policy recommendations and providing empirically informed insights. The work is based on various data obtained from platforms such as Kaggle and using advanced visualization techniques such as Power BI dashboards. The study provides invaluable perspectives on future energy needs, the penetration of renewable sources into the energy mix, and the strategic needs to achieve sustainable energy use.

Irregularity and time series trend analysis of rainfall in Johor, Malaysia

Due to its effect on weather and its propensity to cause catastrophic incidents, climate change has garnered considerable global attention. Depending on the area, the effects of climate change may vary. Rainfall is among the most significant meteorological factors associated with climate change. In Malaysia, changes in rainfall distribution pattern have led to many floods and droughts events which lead to La Nina and El Nino where Johor is one of the states in southern part that usually affected. Thus, rainfall trend analysis is important to identify changes in rainfall pattern as it gives an initial overview for future analysis. This research aims to evaluate historical rainfall data of Johor between 1991 and 2020. Normality and homogeneity tests were used to ensure the quality of data followed by Mann-Kendall and Sen's slope analysis to determine rainfall trend as the rainfall data is not normally distributed (p > 0.05). Standardized precipitation anomaly, coefficient of variation, precipitation concentration index and rainfall anomaly index were used to identify rainfall variability and intensity while standard precipitation index was used to evaluate drought severity. The lowest annual rainfall recorded was 1725.07 mm in 2016 and the highest was 2993.19 mm in 2007. Annual rainfall and seasonal rainfall showed a declining trend although it is not statistically significant (p > 0.05). Results reveal that Johor experienced extreme wet and dry years, leading to drought and flood incidents. Major floods arose in 2006, 2007, 2008, 2010 and 2011 while driest years occurred in 1997, 1998 and 2016 which led to El Nino phenomenon. March and April were identified as the driest months among all. Thus, the findings from this study would assist researchers and decision-makers in the development of applicable adaptation and mitigation strategies to reduce climate change impact. It is recommended that more data analysis from more stations should be done in the future research study to obtain a clearer view and more comprehensive results.

Are long-term biomonitoring efforts overlooking crayfish in European rivers?

BackgroundLong-term biomonitoring of macroinvertebrates is a popular and valuable approach for assessing the status of freshwater ecosystems, identifying the impact of stressors, and evaluating ecosystem health. Although macroinvertebrate-based biomonitoring can be effective in detecting changes in distribution patterns and community trends over time, crayfish often remain undetected or unreported by biomonitoring efforts despite their importance in maintaining the functioning of aquatic ecosystems.ResultsBy analyzing a comprehensive database of long-term macroinvertebrate time series, we found that most sampling methods and assessment schemes can detect both native and non-native crayfish in running waters if sites are continuously sampled. However, native crayfish were detected to a lesser extent and by fewer methods. Kick-net sampling and assessment techniques prevailed as the most efficient methods for capturing crayfish. However, the substantial number of time series lacking crayfish data calls into question whether these methods are sufficiently comprehensive to encapsulate crayfish populations accurately. The use of other targeted methods such as baited traps or hand catching may provide a more reliable estimate of their presence.ConclusionsGiven the detrimental impacts of non-native crayfish and the decline in native crayfish populations, we strongly recommend that stakeholders and managers incorporate a combination of these approaches into their monitoring efforts. The use of different taxonomic levels (family vs. genus vs. species level) in estimating biological indices and biomonitoring tools can cause delays in identifying new non-native specie’s occurrences, hindering effective water quality assessment and ecosystem management by governments and stakeholders. Therefore, whenever possible, we call for standardized taxonomic levels for biomonitoring studies and management strategies to accurately address these issues and make recommendations going forward.

Changing Epidemiology of Clinical Isolates of Candida Species during the Coronavirus Disease 2019 Pandemic: Data Analysis from a Korean Tertiary Care Hospital for 6 Years (2017-2022).

This study assessed the changes in Candida species distribution and antifungal susceptibility patterns during the coronavirus disease 2019 (COVID-19) pandemic compared with a pre-pandemic period in Korea. We retrospectively investigated the specimen, species type, and antifungal susceptibility of Candida isolates obtained between 2016 and 2022. Data between two periods were compared: 2016-2019 (pre-pandemic) and 2020-2022 (pandemic). We included 11,396 clinical isolates of Candida species (5137 isolates in the pre-pandemic and 6259 isolates in the pandemic). The most prevalent species was Candida albicans (50.4%), followed by Candida glabrata (22.7%), Candida tropicalis (12.5%), and Candida parapsilosis complex (12.5%). Their ranks were unchanged; however, their relative isolation ratios varied during the pandemic, exhibiting differences ranging from 0.4 to 2.5 across species. The incidence of candidemia increased during the pandemic (average 1.79 episodes per 10,000 patient days) compared with pre-pandemic levels (average 1.45 episodes per 10,000 patient days) in both intensive-care-unit (ICU) and non-ICU patients. Additionally, C. parapsilosis complex candidemia increased by 1.6-fold during the pandemic. During the pandemic, C. albicans and C. tropicalis candidemia significantly increased by 1.5- and 1.4-fold in ICU patients. In contrast, C. parapsilosis complex candidemia surged 2.1-fold in non-ICU patients. These species exhibited reduced resistance to fluconazole, voriconazole, caspofungin, and micafungin in the pandemic compared with the pre-pandemic. This study underscores the heightened incidence of Candida-related infections during the COVID-19 pandemic and emphasizes the importance of ongoing surveillance of Candida species epidemiology beyond the pandemic's scope.

Ancient and modern DNA track temporal and spatial population dynamics in the European fallow deer since the Eemian interglacial

Anthropogenic factors have impacted the diversity and evolutionary trajectory of various species. This can be through factors such as pressure on population size or range, habitat fragmentation, or extensive manipulation and translocation. Here we use time-calibrated data to better understand the pattern and processes of evolution in the heavily manipulated European fallow deer (Dama dama). During the Pleistocene, fallow deer had a broad distribution across Europe and were found as far north as Britain during the Eemian interglacial. The last glacial period saw fallow deer retreat to southern refugia and they did not disperse north afterwards. Their recolonisation was mediated by people and, from northern Europe and the British Isles, fallow deer were transported around the world. We use ancient and modern mitochondrial DNA (mtDNA) and mitogenomic data from Eemian Britain to assess the pattern of change in distribution and lineage structure across Europe over time. We find founder effects and mixed lineages in the northern populations, and stability over time for populations in southern Europe. The Eemian sample was most similar to a lineage currently in Italy, suggesting an early establishment of the relevant refuge. We consider the implications for the integration of anthropogenic and natural processes towards a better understanding of the evolution of fallow deer in Europe.

Study of changes in temporal distribution pattern of rainfall at Dapoli station in Konkan region of Maharashtra

Dapoli situated in the Konkan region of Maharashtra is having average annual rainfall of 3587 mm with average number of rainy days 75. The yield of major Kharif season crop rice is affected by the erratic behavior of rainfall. Present study is an attempt to study the rainfall variations at the Dapoli station which will be useful for forecasting the future temporal availability of water. Comprehensive statistical tools were used to investigate trends in averages and monthly rainfall over the station on decadal basis. Forty years (year 1972-2011) daily rainfall data for Dapoli station was used for the analysis. Results of study showed that, decadal mean rainfall depths of June and August were found decreasing and those for September was found increasing. Mean rainfall depth variations for July as well as annual total rainfall were found random. Seven years moving averages showed that, rainfall depths for the months of June, July and August were found decreasing and for month of September was found increasing. In annual rainfall graph a slight decline was observed.

Impact of the implementation of Madrid's low emission zone on NO2 concentration using Sentinel-5P/TROPOMI data

In recent years, several measures and policies have been introduced to safeguard healthy NO2 levels in urban areas, including the creation of low emission zones (LEZs). In November 2018, a traffic-restricted area known as the Special Protection Low Emission Zone (SPLEZ) was established in the core of the city of Madrid, embracing most of its central district. This study aims to evaluate whether the implementation of the LEZ has led to improvements in air quality by analyzing NO2 concentrations in various case scenarios. For this purpose, data from the TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 precursor (Sentinel-5P) were used. The pre- and post-LEZ implementation seasonal analysis (from July 2018 to May 2019) and the entirety of 2022 indicated that the epicenter of transport-related NO2 concentrations did not lie within its boundaries. However, NO2 levels within the SPLEZ peaked during winter, with heating and meteorological factors playing a significant role. Additionally, the findings from the case study of the COVID-19 pandemic demonstrated the influence of human activities on the NO2 concentration in both the SPLEZ and the entire metropolitan area. NO2 emissions decreased during the strict lockdown period and steadily increased as activities resumed. Satellite data was compared to surface-level measurements in each case study, resulting in a linear correlation coefficient of 0.72. TROPOMI data was found to closely align with surface-level observations as pollution levels increased, contrasting with better air quality scenarios. Despite certain limitations, it can serve as a valuable tool for providing complementary information to surface-level data, particularly in characterizing changes in pollution distribution patterns.

Study on Mechanical Effect and Plastic Zone Distribution of Tunnel Surrounding Rock in the Presence of Various Expansion Approaches

To examine the distribution of the plastic zone of the surrounding rock subjected to various expansion approaches used for the existing tunnels, this article deals with the distribution and thickness of the plastic zone of the surrounding rock subjected to one-sided expansion excavation (1SEE), two-sided expansion excavation (2SEE), and surrounding expansion excavation (SEE). First, the mechanical model of tunnel expansion is established and the initial stress field 1SEE and expansion stress field of tunnel surrounding rock are analyzed. The finite element model of tunnel expansion is developed to examine the plastic zone distribution in the presence of various tunneling approaches. The obtained results reveal that with the growth of expansion size, the plastic distribution area grows, with a maximum increase rate of 138.5%; the difference of each position reduces, with the difference value of each part less than 0.2 m. The plastic zones of 2SEE and SEE approaches are almost symmetrically distributed around the tunnel center line, and the invert and vault of the SEE tunnel are excavated at the same time, the excavation size is the same, and the difference in plastic zone range is small. With the rise of the lateral pressure coefficient, the distribution pattern of the plastic zone changes from X-type to butterfly-type and then to ellipse-type.

Nuclear Distribution of the Chromatin-Remodeling Protein ATRX in Mouse Early Embryos during Normal Development and Developmental Arrest In Vitro.

The chromatin-remodeling protein ATRX, which is currently recognized as one of the key genome caretakers, plays an important role in oogenesis and early embryogenesis in mammals. ATRX distribution in the nuclei of mouse embryos developing in vivo and in vitro, including when the embryos are arrested at the two-cell stage-the so-called two-cell block in vitro-was studied using immunofluorescent labeling and FISH. In normally developing two- and four-cell embryos, ATRX was found to be closely colocalized with pericentromeric DNA sequences detected with a probe to the mouse major satellite DNA. The association of ATRX with pericentromeric heterochromatin is mediated by nuclear actin and reduced after the treatment of embryos with latrunculin B. When culturing embryos in vitro, the distribution pattern of ATRX changes, leading to a decrease in the association of this protein with major satellite DNA especially under the two-cell block in vitro. Taken together, our data suggest that the intranuclear distribution of ATRX reflects the viability of mouse embryos and their probability of successful preimplantation development.

Analysis of Land Value Change in Genuk District

Genuk District is a district in Semarang City which is designated as an industrial area. The development of industrial estates can lead to increased urbanization. According to data from Central Agency on Statistics in 2020, the population in Genuk District has always increased from year to year. The increasing population causes the need for land to also increase. Land prices can also rise considering the need for land and factors from industrial development. On the other hand, Genuk District is prone to tidal flooding. The worst tidal floods in Genuk District occurred in Gebangsari, Genuk and Banjardowo Sub-District in the 2000s. Based on the problem, this research aims to map land prices temporally in 2014, 2019 and 2022 and analyze the distribution pattern of land value changes in Genuk District with the Local Moran’s I method. That method is used for analyze the pattern of land values in 2022 and the pattern of land price changes between 2019 and 2022. The method used in mapping land prices is based on a fair market land price approach and land valuation techniques using a mass valuation cost approach. The average land value zone in 2014 has a value of IDR 711,000 in 2019 has an average value of IDR 986,000 and in 2022 is IDR 1,599,000. According to the results of Local Moran’s I, the pattern land value change in 2019-2022 is different from the results of the land value pattern in 2022 for each category class. This shows that the high land value changes between 2019 to 2022 are not in the same location as the high land value in 2022.

Abstract C079: H. pylori eradication for mitigating gastro-duodenal cancers: Modeling pharmacokinetics of levofloxacin niosomes in Sprague-Dawley rats

Abstract Eradication of Helicobacter pylori (H. pylori) and, hence, control of its associated conditions (peptic ulcer, gastric cancer, and lymphoma) still constitute major challenge to therapeutics. H. pylori has been implicated in 60% of gastric and 90 % of duodenal ulcers and has been classified as a Class 1 carcinogen in human by the International Agency for Research on Cancer and the World health Organization (Enerson et al, 2016; Vogiatzi et al, 2007; WHO). It affects 4million people world-wide of which 0.5million is from the US and 70% are of 25-64 y/o (Chung & Shelat, 2017). Presently, gastric cancer is the second leading cause of neoplastic mortality globally (Contreras et al, 2014; Owen et al, 2018). The efficacy of currently used antibiotics (erythromycin, clarithromycin, levofloxacin, and azithromycin) in triple or quadruple combinations with proton pump inhibitor (PPI) is decreasing due to resistance development via lipopolysaccharide modification, increased drug efflux, and reduced porin pathway. Adaptive response by bacteria to specific signal due to antibacterial presence in its environment, leading to up-regulation of the efflux system (MexXY/OprM), and down-regulation of porin pathway (OprD) has been recognized as key factor in the resistance manifestation. In an earlier study, we reported that encapsulation of an anti-H. pylori drug (levofloxacin) molecules in niosomes (nano-size lipid vesicles) improved its molecular assimilation by drug-resistant E. coli and Ps. aeruginosa and produced approximately 50 % reduction in their minimum inhibitory concentrations (MIC) (Jankie et al, 2012). In this study, we investigated the in vivo bioavailability of levofloxacin niosomes administered intraperitoneally to Sprague Dawley rats. Plasma data modelling in Gastroplus PKTM for non-compartmental through 3-compartmental models, using Hooke & Jeeves pattern search, indicated that pure levofloxacin obeyed two-compartment kinetic model, while levofloxacin niosomes demonstrated one-compartmental model. In addition, niosome encapsulation increased drug exposure (AUC) about 5 folds and duration of action (mean residence time, MRT) about 1.6 folds. Thus, niosome encapsulation changed distribution pattern and the values of PK parameter supported 2-compartmental and 1-compartmental models for levofloxacin and its niosomes respectively. The knowledge of in vivo rodent PK generated in this study is vital for the determination of test doses in a higher animal species and, subsequent, for the calculation of thee first in human dose of levofloxacin using allometric equations. Generally, the potential is quite high for niosomes encapsulation to enhance the efficacy of other anti-H. pylori drugs against drug-resistant bacterial strains and needs to be investigated. Citation Format: Amusa S. Adebayo, Satish Jankie. H. pylori eradication for mitigating gastro-duodenal cancers: Modeling pharmacokinetics of levofloxacin niosomes in Sprague-Dawley rats [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr C079.

Response of a Sylvan Moss Species (Didymodon validus Limpr.) with a Narrow Distribution Range to Climate Change

Mosses are particularly susceptible to climate change owing to their close biological and ecological associations with climatic conditions. However, there is a limited understanding of the changes in distribution patterns of the moss species in forest ecosystems under climate change, especially in mosses with narrow ranges. Therefore, we reconstructed historical, simulated present, and predicted future potential distribution patterns of Didymodon validus, a narrow-range moss species in the forest ecosystem, using the MaxEnt model. The aim of this study was to explore its unique suitable habitat preference, the key environmental factors affecting its distribution, and the distributional changes of D. validus under climate change at a long spatial-time scale. Our findings indicate that the most suitable locations for D. validus are situated in high-altitude regions of southwestern China. Elevation and mean temperature in the wettest quarter were identified as key factors influencing D. validus distribution patterns. Our predictions showed that despite the dramatic climatic and spatial changes over a long period of time, the range of D. validus was not radically altered. From the Last Interglacial (LIG) to the future, the area of the highly suitable habitat of D. validus accounted for only 15.3%–16.4% of the total area, and there were weak dynamic differences in D. validus at different climate stages. Under the same climate scenarios, the area loss of suitable habitat is mainly concentrated in the northern and eastern parts of the current habitat, while it may increase in the southern and eastern margins. In future climate scenarios, the distribution core zone of suitable habitat will shift to the southwest for a short distance. Even under the conditions of future climate warming, this species may still exist both in the arid and humid regions of the QTP in China. In summary, D. validus showed cold and drought resistance. Our study provides important insights and support for understanding the impact of climate change on the distribution of D. validus, as well as its future distribution and protection strategies.