Influence Of Season Research Articles

Litterfall variation and soil nutrient dynamics in Swietenia macrophylla, Samanea saman and Bambusa blumeana woodstands: Implications for nutrient cycling and soil fertility

This study addresses the knowledge gap regarding litterfall dynamics in university wood stands, focusing on Tarlac Agricultural University and its diverse tree species. While extensive research exists on soil dynamics and litterfall in large-scale plantations and forested areas in the Philippines, university wood stands remain understudied. The research assesses and compares litterfall variation among Swietenia macrophylla, Samanea saman and Bambusa blumeana, exploring implications for nutrient cycling, soil fertility, and amelioration. Litterfall was collected using the catch net method, followed by soil nutrient analyses to establish correlations. Results indicate significant variations in litterfall quantity, organic matter, phosphorus, and nitrogen across akasya, mahogany, and kawayang tinik woodstands. S. macrophylla (mahogany) shows the highest litterfall production (39.97 gday-1), while S. saman (akasya) exhibits the highest organic matter content in both top and subsoil layers (2.23% and 1.69%). B. blumeana (kawayang tinik) woodstands demonstrate elevated nitrogen and phosphorus levels in the topsoil (0.09% and 27 ppm) while S. saman showing the highest levels in the subsoil (0.08% and 18 ppm). The study also highlights the influence of leaf senescence seasonality on litterfall production and species-specific nutrient composition in soil layers. Notably, kawayang tinik shows promise for soil amelioration due to its substantial litterfall production and positive soil quality impact. In conclusion, this research provides valuable insights into litterfall and soil nutrient dynamics in university wood stands, emphasizing the role of plant species and offering practical implications for soil management strategies. B. blumeana emerges as pivotal for enhancing soil fertility and amelioration, with broader implications for sustainable agriculture practices.

Fire, environmental and anthropogenic controls on pantropical tree cover

Explaining tropical tree cover distribution in areas of intermediate rainfall is challenging, with fire’s role in limiting tree cover particularly controversial. We use a novel Bayesian approach to provide observational constraints on the strength of the influence of humans, fire, rainfall seasonality, heat stress, and wind throw on tropical tree cover. Rainfall has the largest relative impact on tree cover (11.6–39.6%), followed by direct human pressures (29.8–36.8%), heat stress (10.5–23.3%) and rainfall seasonality (6.3–22.8%). Fire has a smaller impact (0.2–3.2%) than other stresses, increasing to 0.3–5.2% when excluding human influence. However, we found a potential vulnerability of eastern Amazon and Indonesian forests to fire, with up to 2% forest loss for a 1% increase in burnt area. Our results suggest that vegetation models should focus on fire development for emerging fire regimes in tropical forests and revisit the linkages between rainfall, non-fire disturbances, land use and broad-scale vegetation distributions.

Chronological changes in the Black Sea level at tide gauge station Varna 1928-2023

This paper outlines time series data analysis from Varna tidal station (Black sea, Bulgaria), with the objective being to determine the influences of long-period and short-period tides. Observations series from monthly mean sea level values cover the period 1928-2023. The sea level measurements until 2013 were done with a mechanical float tide gauge. Since 2013 a radar tide gauge was installed in place of the mechanical one. A least squares linear regression model was applied for the analysis of monthly sea level data. As a result of the analysis, mean sea level, trend, seasonal and long-term tidal influences were established. In order to determine the influence of short-term tides, the method of least squares harmonic analysis was applied. In this method, observed sea level values are considered to be represented as a sum of tidal harmonics operating at previously known frequencies. The observation data include hourly values for the period 06.2013-12.2023. Some of the advantages of the applied method are that it allows to analyze series with interruptions in the observations, as well as assist to easily determine tides with close frequencies. From the analysis was determined the influence of: the annual and semi-annual tides, as well as about 68 short-period tides.

Characterization of Thrombocytopenia in Pediatric Patients in Noncritical Hospital Setting: An Institutional Review From Pakistan

Pediatric thrombocytopenia is frequently observed in critical care and oncology settings with an increased risk of bleeding and platelet transfusions. However, little is known about low platelets in childhood during seasonal influence. This study aimed to evaluate the frequency and severity of pediatric thrombocytopenia in the postflood period. The patients aged 1 to 18 years with thrombocytopenia (platelet count <150×109/L) were studied from August to December 2022 after institutional ethical approval (ERC-Path-2022-8044-23395). Data was collected from electronic health records and laboratory information systems. Of 2318 admitted patients, 192 (8.3%) including 128 males and 64 females had thrombocytopenia. The median (IQR) age was 12 (8 to 15) years. Mild, moderate, and severe thrombocytopenia were seen in 109 (56.8%), 76 (39.5%), and 7 (3.6%) patients, respectively. Concomitant leucopenia was observed in 77 of 192 patients (40.1%). Infection was the predominant cause of low platelets (N=175 or 91.1%). Only 15 patients (7.8%) had grade 1/2 bleeding. Overall, 176 patients (92%) were discharged in stable conditions and no mortality was observed. The frequency of pediatric thrombocytopenia in the noncritical and nononcological care settings was <10% and mostly observed in association with underlying infections. The frequency of bleeding manifestation and platelet transfusions was minimal in this group.

The relationship between seasonality and the diagnosis of acute leukaemia in central South Africa

Background: Leukaemias are haematological malignancies resulting from the abnormal clonal proliferation of haematopoietic precursors. Their incidence is influenced by various environmental and genetic factors.Aim: With this retrospective descriptive study, the authors aimed to explore the possible influence of seasonality on the type and number of acute leukaemia (AL) diagnoses made at the Universitas Academic Hospital (UAH) National Health Laboratory Service (NHLS) from 01 January 2018 to 31 December 2021.Setting: Universitas Academic Hospital, Bloemfontein, South Africa.Methods: Archived laboratory reports of all patients diagnosed with lymphoid and myeloid during the study period were included. Patients’ age, sex, ethnicity, final diagnosis and date of diagnosis were recorded. Information was pseudonymised to maintain confidentiality. A descriptive statistical analysis was performed to explore the possible influence of seasonality on the number of cases and type of leukaemia diagnosed.Results: In all, 249 patients were included. Acute myeloid leukaemia (AML) was the most common AL subtype (n = 117; 47.0%). Over the 4-year study period, all AL subtypes were more frequently diagnosed in summer (n = 131; 52.6%). However, the monthly number of AL diagnoses was relatively consistent over the 4 years for all subtypes (p = 0.7603), with consistent peaks of AML cases during January and February (summer) and May (autumn).Conclusion: No statistically significant association between the different seasons and AL diagnosis was noted.Contribution: Further studies using a larger study population and a wider geographical area, conducted over a more extended period, might affect the observations made in this study

Exploring the Relationship Between Very-High-Resolution Satellite Imagery Data and Fruit Count for Predicting Mango Yield at Multiple Scales

Tree- and block-level prediction of mango yield is important for farm operations, but current manual methods are inefficient. Previous research has identified the accuracies of mango yield forecasting using very-high-resolution (VHR) satellite imagery and an ’18-tree’ stratified sampling method. However, this approach still requires infield sampling to calibrate canopy reflectance and the derived block-level algorithms are unable to translate to other orchards due to the influences of abiotic and biotic conditions. To better appreciate these influences, individual tree yields and corresponding canopy reflectance properties were collected from 2015 to 2021 for 1958 individual mango trees from 55 orchard blocks across 14 farms located in three mango growing regions of Australia. A linear regression analysis of the block-level data revealed the non-existence of a universal relationship between the 24 vegetation indices (VIs) derived from VHR satellite data and fruit count per tree, an outcome likely due to the influence of location, season, management and cultivar. The tree-level fruit count predicted using a random forest (RF) model trained on all calibration data produced a percentage root mean squared error (PRMSE) of 26.5% and a mean absolute error (MAE) of 48 fruits/tree. The lowest PRMSEs produced from RF-based models developed from location, season and cultivar subsets at the individual tree level ranged from 19.3% to 32.6%. At the block level, the PRMSE for the combined model was 10.1% and the lowest values for the location, seasonal and cultivar subset models varied between 7.2% and 10.0% upon validation. Generally, the block-level predictions outperformed the individual tree-level models. Maps were produced to provide mango growers with a visual representation of yield variability across orchards. This enables better identification and management of the influence of abiotic and biotic constraints on production. Future research could investigate the causes of spatial yield variability in mango orchards.

Seasonal persistence of the nitrogen oxides production in Mexico City

AbstractThis study investigates the seasonal influence on the nitrogen oxide NOx pollution records at four monitoring sites in Mexico City from 2010 to 2018. The analysis employs the second-order structure function to examine the trends in NOx concentration fluctuations. The findings reveal that the fluctuations follow a power law pattern characterized by Hurst exponents, predominantly in the statistical persistence regime, with a scaling range spanning three orders of magnitude. Specifically, the autumn period exhibits fluctuations with an exponent of $$\overline{H}=0.72$$ H ¯ = 0.72 , indicating relatively smaller fluctuations compared to other seasons, but with the potential for NOx concentrations to surpass those in other periods. In contrast, for spring, summer, and winter, the fluctuations are characterized by exponents of$$\overline{H}=0.59$$ H ¯ = 0.59 ,$$\overline{H}=0.61$$ H ¯ = 0.61 , and$$\overline{H}=0.62$$ H ¯ = 0.62 , respectively, demonstrating greater fluctuations with lower NOx concentrations compared to autumn. These results are consistent with various studies conducted worldwide. Additionally, a negative correlation between NOx and ozone (O3) has been established during the winter season, as NOx and O3 fluctuations display persistent and anti-persistent behavior, respectively.

Temperature Effects on the Distribution of Aragonitic and Calcite‐Secreting Epifaunal Bivalves

ABSTRACTAimTo test if temperature significantly influences the global biogeographic distribution of marine epifaunal bivalves via their skeletal mineralogy.LocationGlobal.TaxaMarine, epifaunal bivalves.MethodsThe skeletal mineralogy of 45,789 epifaunal bivalve occurrences from 669 species from the Ocean Biodiversity Information System (OBIS) was related to sea surface temperatures from Bio‐ORACLE. Binomial regression was used to assess the influence of temperature and seasonality on the distribution of aragonitic and calcite‐secreting bivalve occurrences, aggregated in equal‐area grid cells.ResultsThe proportion of aragonitic bivalve occurrences significantly increases with mean annual temperature in our global analysis and most marine biogeographic realms. A greater prevalence of calcite‐secreting bivalves in seasonal climates could be shown at low mean annual temperatures at the global scale but not within biogeographic realms.Main ConclusionsThe global biogeographic distribution of epifaunal bivalves is significantly influenced by water temperature via their skeletal mineralogy. The mechanism driving this pattern is best explained by the temperature modulation of the effect of Mg2+ on calcite growth. Although this Mg2+ effect predicts an advantage for aragonite secretion at higher temperatures, poleward migration in response to higher temperature extremes will expose tropical taxa to cooler temperatures in the cold season, which may impede aragonite secretion in taxa not adapted to these climates.SignificanceOur results suggest that skeletal mineralogy is likely to influence ocean warming‐induced migration patterns.

Seasonal influence on the cultivation of important oyster species and their productivity in east and south eastern coastal plains of Odisha

Seasonal influence on the cultivation of important oyster species and their productivity in east and south eastern coastal plains of Odisha

Seasonal Influence on the Impact of Human Chorionic Gonadotropin (hCG) on Testicular Haemodynamics and Hormonal Responses in Canines: A Comparative Study.

Human chorionic gonadotropin (hCG) is widely used to treat reproductive dysfunction by enhancing testicular blood flow and stimulating hormonal activity. This study investigates the seasonal variations in the response to hCG treatment in male dogs, focusing on its effects on testicular blood flow and plasma concentrations of testosterone and oestrogen. Conducted across different seasons (spring, summer, fall and winter), the study utilised colour Doppler ultrasonography to measure testicular haemodynamics and analysed hormonal levels at multiple time points post-hCG injection. The findings revealed that the response to hCG is modulated by seasonal factors, with significant variations in both blood flow and hormone levels. A significant negative relationship was indicated between testicular blood flow and testosterone levels, particularly during spring and summer. These results suggest that seasonality should be considered when administering hCG for reproductive treatments in canines.

Seasonal influences on the efficacy of anti-programmed cell death (ligand) 1 inhibitors in lung cancer.

Seasonal variations in systemic immunity have been reported. This study aimed to evaluate whether seasonality affects the efficacy of anticancer immunotherapy. A total of 604 patients with lung cancer receiving single anti-programmed cell death (ligand) 1 (anti-PD-[L]1) inhibitors from two prospective observational cohorts were screened. Primary outcomes were progression-free survival (PFS) and overall survival (OS). Patients were classified into two groups according to the season when the treatment started: winter (November-February) and other seasons (March-October). Kaplan-Meier analysis and Cox proportional hazards models were fitted to evaluate the impact of seasonality on survival. For validation, propensity score matching was performed. A total of 484 patients with advanced non-small cell lung cancer were included. In an unmatched population, multivariable analysis demonstrated that the winter group (n=173) had a significantly lower risk of progression or death from immunotherapy than the other group (n=311) (PFS: hazard ratio [HR],0.77 [95% confidence interval (CI), 0.62-0.96]; p=.018; OS: HR,0.77 [95% CI, 0.1-0.98]; p=.032). In a propensity score-matched population, the winter group (n=162) showed significantly longer median PFS (2.8 months [95% CI, 1.9-4.1 months] vs. 2.0 months [95% CI, 1.4-2.7 months]; p=.009) than the other group (n=162). The winter group's median OS was also significantly longer than that of the other group (13.4 months [95% CI, 10.2-18.0 months] vs. 8.0 months [95% CI, 3.6-8.7 months]; p=.012). The trend toward longer survival in the winter group continued in subgroup analyses. Starting an anti-PD-(L)1 inhibitor in winter was associated with better treatment outcomes in patients with lung cancer compared to other seasons.

Comparative analyses on nitrogen removal microbes and functional genes within anaerobic-anoxic-oxic and deoxidation ditch sewage-treating processes in Wuhan and Xi'an cities, China.

Anaerobic-anoxic-oxic (A2/O) and deoxidation ditch (DOD) processes are being increasingly preferred owing to their effectiveness in treating various wastes in wastewater treatment plants (WWTPs). Considering seasonal variations is crucial in optimizing treatment processes, ensuring compliance with regulations, and maintaining the overall efficiency and effectiveness of WWTPs. This study aimed to determine the influence of seasonality on nitrogen removing microbes and functional genes within A2/O and DOD processes in the humid Wuhan and semi-arid Xi'an cities, China. The physicochemical parameters of water quality were determined, and molecular and bioinformatic analyses of the bacterial community and nitrogen metabolism functional genes in the two different treatment processes of two WWTPs were performed over four seasons. Our analyses revealed a significant difference in all physicochemical parameters across all experimental groups (p < 0.05). At the genus level, the abundance of Dokdonella, one unidentified genus of Nitrospiraceae, Terrimonas, and one unidentified genus of Chloroflexi was the highest in all groups. Generally, warmer seasons exhibited higher biodiversity indices. The A2/O system exhibited higher values in terms of most nitrogen metabolism functional genes than those of the DOD sewage treatment system. In both WWTPs, the abundance of most genes in spring and summer were higher than that of autumn and winter seasons. Taken together, changes in temperature, caused by seasonal changes, may contribute to changes in abundance of nitrogen metabolic functional genes.

Prevalence of immunoglobulin E sensitisation to mites and pollens in 25,451 French dogs from 2016 to 2022.

Canine atopic dermatitis (cAD) is a common skin disorder in dogs, wherein allergens are presumed to exert a significant influence. The prevalence of allergen sensitisation in dogs with suspected cAD remains inadequately investigated in France. This study aimed to analyse allergen-specific immunoglobulin (Ig)E test results from French dogs with suspected cAD, exploring potential risk factors influencing sensitisation. The study included 25,451 client-owned dogs presented with clinical signs of cAD between January 2016 and December 2022. The study population consisted of 226 pure breeds and 915 cross-bred dogs of both sexes, with a mean age of 4.4 (±2.8) years. Data collection involved the compilation of results from canine serological allergen-specific IgE ELISA tests, using a 23 allergen composite panel. The influence of breed, sex, age, geographical area and sampling season on IgE test outcomes subsequently was analysed. Of the 25,451 analysed samples, 75.6% exhibited significant serum IgE concentrations in response to at least one of the tested allergens, with 67.9% testing positive for mites and 39.8% for pollens. Breed, sex, age, geographical area and sampling season were identified as significant risk factors influencing sensitisation patterns. This study provides insights into the prevalence and risk factors associated with allergen sensitisation in dogs with suspected cAD. Understanding these factors is crucial for effective diagnosis and tailored management strategies in veterinary practice. The findings underscore the need for personalised approaches in addressing cAD, considering individual patient characteristics.

Effects of tree species identity on soil microbial communities in Juglans nigra and Quercus rubra plantations.

Understanding how different tree species affect soil microbial communities is crucial for sustainable forestry and ecosystem management practices. Despite Black walnut (Juglans nigra L.) forestry having a rich history, the overall comprehension of how this hardwood species influences soil remains incomplete. In earlier studies, we examined the effects of hardwood plantations on soil chemical properties and their interaction with microbial biomass, however, we highlight the importance of studying the soil microbial communities and their relationship with soil properties in greater depth. Building on this foundation, our research focused on evaluating microbiome compositions beneath J. nigra and another hardwood, Northern red oak (Quercus rubra L.) after a decade of establishment. We uncovered intriguing patterns within the soil bacterial/archaeal and fungal structures by conducting meticulous analyses utilizing amplicon sequencing alongside soil chemical properties. Our findings underscore that tree species play a pivotal role in shaping soil microbial structures, a role that surpasses even seasonal and depth influences. Most notably, J. nigra stands out for its ability to enhance microbial diversity, as evidenced by increased alpha-diversity indices compared to baseline values. Conversely, Q. rubra tends to decrease these indices. Significant disparities in microbial composition between the two tree species were evident, with J. nigra exhibiting enrichment in certain taxa such as Nitrospira, Geobacter, and Bacillus while Q. rubra showed enrichment in others like Acidobacteriota and ectomycorrhizal fungi. Furthermore, we also observed differences in co-occurrence networks by delving deeper into the interconnections within the soil microbiota. In both fungal and bacterial/archaeal communities, J. nigra and Q. rubra notably decreased the number of connections within their networks, while Q. rubra increased some, suggesting a more interconnected network. These differences were further highlighted by network metrics with Q. rubra displaying a higher mean degree and clustering coefficient. Additionally, our analysis revealed that tree species influence soil chemical properties, either directly or indirectly, thereby affecting soil bacterial and fungal communities. In conclusion, our study elucidates the intricate interplay between tree species and soil microbiota, emphasizing the need to consider these relationships in forestry and ecosystem management practices.

The dynamic relation between fertilization, precipitation and the diffusion of agricultural non-point pollution in Hainan Island

With the increasing demand for crops, the excessive application of fertilizers has gradually become a significant factor affecting water quality. Therefore, studying the relationship between agricultural fertilizer runoff and water quality is crucial for the sustainable development of agricultural production. The present study sets up a new dynamic model of nitrogen fertilizer loss, introducing variables such as precipitation, fertilization application during dry and rainy seasons, and their lagged and interaction terms. The paper analyzed the issue of fertilizer runoff under the complex interactions of various factors, including spatial and temporal scales and climatic conditions, and explored the relationship between agricultural activities and water quality changes in the context of sustainable development. Due to Hainan Island’s independent river system, which is free from transboundary pollution, and its low level of industrial pollution, it provides an excellent sample for assessing the impact of agricultural non-point source pollution on water quality. Based on watershed monitoring data from Hainan Island, this study draws the following conclusions: 1. Precipitation exhibits a pronounced seasonal influence on total nitrogen concentration. 2. Nitrogen fertilizer enters into water bodies through precipitation, resulting in a lag effect on total nitrogen concentration. 3. The influence of grain and tropical crops on nitrogen loss is less significant, while cash crops will trigger the nitrogen overloading of rivers in scenarios where they account for a high proportion of the planting structure of the sown area.

Reliability of 24-h measurement of physical activity, sleep, and sedentary time in adult patients with asthma using a triaxial accelerometer

Objective Physical activity (PA), sleep, and sedentary time (SST) are important outcomes to monitor and to improve as part of patients’ asthma management. This study aimed to assess the number of measurement days needed to reliably measure PA and SST. Secondly, the influence of external factors on the reliability of measuring PA and SST was studied. Methods Adult patients with stable asthma were asked to wear a triaxial accelerometer for at least four days, with at least 22.5 h of wear time per day. The Intraclass Correlation Coefficients (ICCs) between different number of measurement days were used to determine reliability. Values ≥0.75 indicated good reliability. Results: Data from 452 patients were analyzed (63% women; age: 49 ± 16 years; FEV1: 87 ± 17% predicted). PA could reliably be measured with four valid measurement days (ICC 0.761). For SST, three days were needed (ICC 0.778). In summer and autumn, three days were needed to reliably measure PA, in winter four, in spring six. For SST, five days were needed in spring for good reliability, and two in all other seasons. Conclusion: Based on data from four valid days, PA and SST can reliably be measured with an accelerometer in patients with asthma. Seasonal influences are present, especially during spring. When measuring for four days, using only weekdays or three weekdays and one weekend day is recommended. The degree of asthma control, dyspnea or spirometric values did not influence the reliability.

Seasonal influence on tomato fruit metabolome profile: Implications for ABA signaling in multi-stress resilience

The increasing effects of climate change are leading to an increase in the number and intensity of extreme events, making it essential to study how plants respond to various stresses occurring simultaneously. A crucial regulator of plant responses to abiotic stress is abscisic acid (ABA), as its accumulation in response to stress leads to transcriptomic and metabolomic changes that contribute to plant stress tolerance. In the present study, we investigated how ABA, stress conditions (salinity, water deficit and their combination) and seasons (autumn-winter and spring-summer) regulate tomato fruit yield and metabolism using tomato wild type (WT) and the ABA-deficient flacca mutant (flc) under stress conditions in cold and warm seasons. Our results showed that the applied stresses did not have the same effect in the warm season as in the cold season. In WT plants, the levels of other flavonoids, lignans and other polyphenols were higher in summer fruits, whereas the levels of anthocyanins, flavanols, flavonols, phenolic acids and stilbenes were higher in winter fruits. Furthermore, the significant increase in anthocyanins and flavonols was associated with the combination of salinity + water deficit in both seasons. Additionally, under certain conditions, flc mutants showed an enrichment of the superclasses of benzenoids and organosulphur compounds. The synthesis of phenolic compounds in flc fruits was also significantly different compared to WT plants. Thus, the metabolic profile of tomato fruits varies significantly with endogenous ABA levels, season of cultivation and applied stress treatments, highlighting the multifactorial nature of plant responses to combined environmental factors.

Drivers of phytoplankton distribution, abundance and community composition off East Antarctica, from 55-80°E (CCAMLR Division 58.4.2 East)

Southern Ocean phytoplankton form the base of the Antarctic food web, influencing higher trophic levels through biomass and community structure. We examined phytoplankton distribution and abundance in the Indian Sector of the Southern Ocean during austral summer as part a multidisciplinary ecosystem survey: Trends in Euphausiids off Mawson, Predators and Oceanography (TEMPO, 2021). Sampling covered six meridional transects from 55-80°E, and from 62°S or 63°S to the ice edge. To determine phytoplankton groups, CHEMTAX analysis was undertaken on pigments measured using HPLC. Diatoms were the dominant component of phytoplankton communities, explaining 56% of variation in chlorophyll a (Chl a), with haptophytes also being a major component. Prior to sampling the sea ice had retreated in a south-westerly direction, leading to shorter ice-free periods in the west (&amp;lt; 44 days, ≤65°E) compared to east (&amp;gt; 44 days, ≥70°E), inducing a strong seasonal effect. The east was nutrient limited, indicated by low-iron forms of haptophytes, and higher silicate:nitrate drawdown ratios (5.1 east vs 4.3 west), pheophytin a (phaeo) concentrations (30.0 vs 18.4 mg m-2) and phaeo:Chl a ratios (1.06 vs 0.53). Biological influences were evident at northern stations between 75-80°E, where krill “super-swarms” and feeding whales were observed. Here, diatoms were depleted from surface waters likely due to krill grazing, as indicated by high phaeo:Chl a ratios (&amp;gt; 0.75), and continued presence of haptophytes, associated with inefficient filtering or selective grazing by krill. Oceanographic influences included deeper mixed layers reducing diatom biomass, and a bloom to the north of the southern Antarctic Circumpolar Current Front in the western survey area thought to be sinking as waters flowed from west to east. Haptophytes were influenced by the Antarctic Slope Front with high-iron forms prevalent to the south only, showing limited iron transfer from coastal waters. Cryptophytes were associated with meltwater, and greens (chlorophytes + prasinophytes) were prevalent below the mixed layer. The interplay of seasonal, biological and oceanographic influences on phytoplankton populations during TEMPO had parallels with processes observed in the BROKE and BROKE-West voyages conducted 25 and 15 years earlier, respectively. Our research consolidates understanding of the krill ecosystem to ensure sustainable management in East Antarctic waters.

Riverine CH4 and CO2 emissions respond to associated agricultural land use and seasonality

ABSTRACT Recently, agricultural land use has significantly impacted carbon emissions and water quality in adjacent rivers. This study examined the influence of land-use types and seasonality on carbon emissions from agriculture-impacted rivers in Shanghai. Our results showed that the crop farming land-use-associated river (AR) had CH4 and CO2 fluxes 2.68 and 3.47 times higher, respectively, than those in the aquaculture land-use-AR and 2.86 and 2.81 times higher than in the livestock and poultry breeding land-use-AR. Statistical analyses revealed that total nitrogen, ammonia nitrogen, and humification index were significantly correlated with crop farming land-use-AR carbon emissions. Conversely, no clear correlation was found between chemical factors and carbon fluxes in the aquaculture land-use-AR and livestock and poultry breeding land-use-AR due to the complexity of pollution sources. Seasonality significantly influenced CH4 and CO2 fluxes from agriculture-impacted rivers, with carbon fluxes in summer being 3.5 and 2.5 times higher than in winter, respectively. Crop farming land-use-AR carbon fluxes exhibited the highest variability under seasonal influences. This study emphasizes the need for policies to mitigate agricultural land use impacts on river carbon emissions.

Extrinsic and intrinsic drivers of prevalence and abundance of hard-bodied ticks (Acari: Ixodidae) in one-humped camel (Camelus dromedarius)

BackgroundTicks are ectoparasites and can be vectors of a wide range of pathogens, posing significant health risks to livestock. In the Sahara Desert of Algeria, particularly among one-humped camels (Camelus dromedarius), there is a need to better understand the factors influencing tick infestation patterns to improve livestock management and health outcomes. ObjectivesThis study aimed to investigate the prevalence, intensity, and abundance of hard-bodied ticks (Acari: Ixodidae) among dromedaries, examining both intrinsic factors (sex, age, coat color) and extrinsic variables (farming systems, vegetation types, climate zones, and elevation) that might influence tick infestation in this region. MethodsTicks were collected from 286 dromedaries across nine sites in the pre-Saharan regions of Algeria, with elevations ranging from 736 m to 980 m. The sampled camels, which ranged in age from 6 days to 21 years, were examined for tick infestations. The ticks were identified through macroscopic and microscopic methods, and their abundance was analyzed in relation to the camels' characteristics and environmental factors. Three breeding systems were recognized: extensive, intensive, and mixed. ResultsA total of 980 ticks were collected, with Hyalomma dromedarii Koch, 1844 being the most abundant species (553 specimens), followed by Hyalomma impeltatum Schulze & Schlottke, 1930 (393 specimens), and Hyalomma excavatum Koch, 1844 (34 specimens). H. dromedarii showed a preference for parasitizing brown-coated dromedaries and exhibited significantly higher infestation levels during spring (p < 0.001). No significant association was observed between tick infestation and the camels' age or sex (p > 0.05). However, the farming system had a significant impact on tick abundance, with extensive and mixed systems showing higher tick burdens compared to intensive systems (p < 0.01). Additionally, the vegetation type, climate zone, and foraging habitat elevation were found to significantly influence tick densities and prevalence. ConclusionThis study provides essential insights into the tick infestation dynamics in dromedaries in drylands of Algeria. It highlights the influence of coat color, seasonality, and farming practices on tick burden, with brown-coated camels being more susceptible during the spring. The findings underline the importance of considering both intrinsic and extrinsic factors when developing effective tick control strategies, especially for camels raised in extensive or mixed farming systems in diverse arid rangelands. Future research should expand the scope to cover other arid regions in North Africa for a comprehensive understanding of tick-host dynamics.