Rainy Season Research Articles

Ecological quality of the Jucusbamaba River, a high Andean urban river in northeastern Peru

The Jucusbamaba River, located in the northeastern region of Peru, flows through two towns that use its waters for agricultural activities. However, these activities generate waste discharged back into the river, which is additionally polluted by untreated domestic wastewater discharges. The main objective was to evaluate the ecological quality of this lotic system, analyzing biotic and abiotic parameters during two seasons. The biotic parameters included microinvertebrates and fecal coliforms, while the abiotic parameters encompassed temperature, pH, dissolved oxygen, electrical conductivity, turbidity, total dissolved solids, and biochemical oxygen demand. Six sampling points were established where physicochemical and microbiological parameters were analyzed. Simultaneously, quantitative sampling of macroinvertebrates was carried out at the same points to evaluate their diversity using Shannon- Wiener, Margalef and Simpson indices. The Andean Biotic Index (ABI) and the Biotic Family Index (FBI) were calculated to determine the ecological quality of the river using macroinvertebrates. Finally, the spatio-temporal variation of macroinvertebrate composition and physicochemical and microbiological parameters were analyzed. Very high concentrations of BOD, total dissolved solids, and electrical conductivity were obtained in the dry season, while in the rainy season, they were pH, dissolved oxygen, and turbidity. 12548 individuals from 6 classes, 11 orders, and 26 families were collected. The greatest richness of macroinvertebrate families was found at points 1 and 2, with Trichoptera, Ephemeroptera and Plecoptera individuals predominating. There was evidence of temporal variation in physicochemical and microbiological parameters, as well as in macroinvertebrate composition. It was concluded that the ecological quality of the Jucusbamba River decreases as it follows its course due to anthropic disturbances. This research can be used to develop management plans, awareness-raising, and sanitation measures to ensure the protection and conservation of the Jucusbamaba River.

Research Regarding the Autochthonous Dissolved Organic Carbon to Recalcitrant Dissolved Organic Carbon Transformation Mechanism in a Typical Surface Karst River

Autochthonic recalcitrant organic carbon is the most stable component in karst aquatic systems. Still, the processes of its generation and transformation remain unclear, which hinders the study of the mechanisms and quantitative calculations of carbon sinks in karst aquatic systems. This study collected water samples from the Li River, a typical surface karst river in Southwest China. Through in situ microbial cultivation and the chromophoric dissolved organic matter (CDOM) spectrum, changes in organic carbon components and their contents during the transformation of autochthonic dissolved organic carbon (Auto-DOC) to autochthonic dissolved recalcitrant organic carbon (Auto-RDOC) were analyzed to investigate the inert transformation processes of endogenous organic carbon. This study found that microbial carbon pumps (MCPs) promote the tyrosine-like component condensed into microbial-derived fulvic and humic components via heterotrophic bacteria metabolism, forming Auto-RDOC. During the dry season, the high level of Auto-DOC provides abundant organic substrates for heterotrophic bacteria, resulting in significantly higher Auto-RDOC production compared to the rainy season. This study provides fundamental information on the formation mechanisms of Auto-DOC in karst aquatic systems, which contributes to the assessment of carbon sinks in karst aquatic systems.

Assessment of household preferences for net textile type (polyester versus polyethylene) for decision-making of the National Malaria Control Programme in Burkina Faso: methods for a quasi-experimental study

BackgroundA quasi-experimental comparative trial will be designed in Burkina Faso. The study will compare the use and preferences for two groups types of insecticide-treated nets textile: polyester-based and polyethylene-based, according to their use and preferences in selected health districts. These health districts will be selected in three eco-climate zones (Sahelian, dry savannah and wet savannah) in the country. These findings will inform decisions on future net procurements for national malaria control programme in 2025.MethodsQuantitative surveys and qualitative data collection will be carried out to gather information on the type of net textile most commonly used and preferred by the community. They will be performed between the end of the dry season and the early rainy season. The quantitative surveys involved household interviews with households and individuals’ questionnaires, while the qualitative data collection involved in-depth individual interviews and focus group discussions to explore and clarify some key evaluation criteria. A total of 9450 insecticide-treated nets were surveyed for quantitative survey purposes. For the qualitative study, 48 in-depth individual interviews and 12 focus group discussions were carried out. A mixed model approach combining the results from quantitative surveys and qualitative studies will be used for decision-making on the type of insecticide-treated net preference.ConclusionThis methodological approach will be used by the National Malaria Control Programme to conduct this study on determinants of net use in Burkina Faso in order to provide robust evidence across diverse settings. This mixed-methods approach for data collection and analysis could be used in other countries to provide evidence that would help to increase the uptake of insecticide-treated nets, the main vector control tool in Africa.

Global acute malnutrition is associated with geography, season and malaria incidence in the conflict-affected regions of Ouham and Ouham Pendé prefectures, Central African Republic

BackgroundOngoing conflict between multiple armed groups, including pastoralist herders in the Central African Republic (CAR) causes frequent population displacements, food insecurity and scarcity of healthcare services. The inaccessibility and insecurity of many areas of CAR limit data collection and assessments from national nutritional surveys. Community health workers (CHWs) trained by an international non-governmental organisation, The MENTOR Initiative, deliver basic healthcare to children under 5 years old living in hard-to-reach and conflict-affected areas in eight subprefectures of north-west CAR. Their nutritional status and its associations with geography, malaria, season and conflict are unknown.MethodsCHW monthly records (October 2015–August 2021), Armed Conflict Location and Event Data project conflict data and The World Bank Group meteorological data for eight subprefectures of north-west CAR were analysed. Associations between counts of global acute malnutrition (GAM) assessed by mid-upper arm circumference and malaria, season and conflict were investigated using negative binomial regression.ResultsOf the 457,325 consultations with children aged 6–59 months, 6.2% and 0.4% were classified as moderately or severely malnourished, respectively. The negative binomial model demonstrated differences in counts of GAM by subprefecture. Counts of GAM were positively associated with the case rate of severe malaria (IRR = 1.045; 95% CI: 1.04–1.06) and the rainy season (July–September) (IRR = 1.10; 95% CI: 1.03–1.17). Conflict events coded as Battles in ACLED were associated with lower counts of GAM (IRR = 0.78; 95% CI: 0.62–0.97).ConclusionsThis analysis shows geographical differences in levels of malnutrition in north-west CAR and demonstrates clear associations between malnutrition, season and malaria. It provides evidence that levels of GAM may be underestimated in north-west CAR in areas experiencing conflict. These findings highlight the need for targeted nutritional support to reach children most at risk of malnutrition. CHWs are a proven effective means of delivering essential primary healthcare services in hard-to-reach, conflict-affected areas.

A study on the diversity of phlebotomine sand flies (Diptera, Psychodidae) in karstic limestone areas in Vientiane Province, Laos, with a description of two new species of Sergentomyia França and & Parrot

BackgroundSoutheast Asia is well known as a hotspot of biodiversity. However, very little is known about cave-dwelling hematophagous insects that are medically important. Taxonomic knowledge and ecology of phlebotomine sand flies are very poorly studied in Laos, as well as in other countries in the region. Herein, we report species diversity data and some notes on the ecology of the detected species from these karstic limestone areas of Laos.MethodsPhlebotomine sand flies were collected using Centers for Disease Control and Prevention (CDC) light traps from limestone cave locations in three districts of Vientiane Province, Laos. Both morphological and molecular techniques were used for sand fly identification. Species diversity and abundance were analyzed according to sites, locations, collection seasons, and trapping positions.ResultsA total of 6564 sand flies, of which 5038 were females and 1526 were males, were morphologically identified into 20 species belonging to five genera (Chinius, Idiophlebotomus, Phlebotomus, Sergentomyia, and Grassomyia). The most abundant species were Chinius eunicegalatiae, Phlebotomus stantoni, Sergentomyia hivernus, Se. siamensis, and Idiophlebotomus longiforceps. Cytochrome b analysis results supported the morphological identification and revealed that Se. siamensis was separated from other members of the Se. barraudi group. Two new species, Se. dvoraki n. sp. and Se. marolii n. sp., were described. Sand fly density was generally high except in a cave in Vangvieng, with species richness ranging from 14 to 18 across different caves. Outside caves had higher species richness (R = 20) and diversity (H = 2.50) than cave entrances (R = 18, H = 2.41) and interiors (R = 16, H = 2.13). Seasonal variations showed high sand fly density in Feung and Hinheup during both dry and rainy seasons, while Vangvieng had a notable decrease in density during the dry season (D = 6.29).ConclusionsThis study revealed that the diversity of phlebotomine sand fly fauna in Laos, particularly in karstic limestone areas, is greater than previously known. However, the taxonomic status of many species in Laos, as well as Southeast Asia, still needs more in-depth study using both morphological characters and molecular methods. Many species could be found from inside, at the entrance, and outside of caves, indicating a wide range of host-seeking behavior or possible natural breeding in the karstic cave areas.Graphical abstract

Vegetation dynamics after fire in the Brazilian Campo Rupestre: Effects on native plant communities and flower harvesting

We investigated the impact of both early and late fires on native plant communities of the Campo Rupestre in the Sempre-Vivas National Park (PNSV, Brazil). Everlasting flower harvesters use late fires to stimulate flowering, while park managers have been implementing early fires to reduce flammable biomass and, therefore, the risk of wildfires. We aimed to explore the effects of fire on species composition, vegetation cover, and plant and flower stalks height to evaluate post-fire vegetation recovery, especially considering Comanthera species, which are highly valued by flower harvesters. The experimental design involved two areas (A1 and A2) in PNSV from May/2019 to January/2021. We installed eight 50 × 50 m plots in each area, being half submitted to experimental burnings and the other half unburned (control plots). A1 experienced early fire in May, and A2 a late fire in September. Initial phytosociological surveys revealed differences between A1 and A2, therefore, fire effects were treated separately for each area. In both A1 and A2, fire initially impacted species richness and abundance but the effect dissipated over time, with vegetation becoming similar to unburned plots. Fire also affected vegetation cover, which returned to its original condition within a year, influenced by seasonality and plant phenology. Plant communities experienced a temporary reduction in height (∼4 cm) in the months following fire, and recovered in the subsequent rainy season. However, a tendency for smaller plants persisted, and the average height of flower stalks took almost two years to fully recover. In general, the late fire conducted in A2 led to a slower recovery trajectory. These findings indicate rapid post-fire biomass recovery and minimal impact on plant species composition, highlighting the resilience of Campo Rupestre to single fires. Further studies are crucial to understand plant response to fires at different fire frequencies.

Mangrove snail diversity as a tool for biomonitoring the mangrove based coastal habitats

Mangrove forests play a pivotal role in supporting mangrove associated snails by offering essential functions such as breeding grounds, nursery areas, food sources, and protection from predators. They play a particularly important role in nutrient cycling within mangrove ecosystems. Despite their significance, there has been a lack of studies conducted in Sri Lanka to explore the diversity of mangrove snails. Thus, the objective of this study was to assess the significance of snail species diversity in mangrove ecosystems on the western coast of Kandakuliya, Kalpitiya, Sri Lanka. Five sites were selected using purposive sampling technique at each location, and the sampling was conducted during low tide in daylight hours in both the non-rainy (February) and rainy (September) seasons of 2023. Transects (30 m) were established at each location, with six 1 m² quadrats placed along each transect at 5 m intervals as replicates. The study identified six snail species from three families, with Pirenella cingulata being the most widely distributed across all sites and exhibiting the highest abundance at site 3. Temporally, Pirenella cingulata displayed the highest number of individuals in both the rainy and dry seasons. Diversity indices indicated the highest values at site 1 for the Shannon-Wiener index (H´=1.14), site 5 for Pielou's evenness index (J=0.96), and site 1 for Simpson's diversity index (D=0.67). Pirenella cingulata recorded the highest total abundance at 85,840 individuals. Variations in these findings may be attributed to water quality factors such as temperature and dissolved oxygen, as well as mangrove dominance and climatic conditions. The study suggests that incorporation of environmental parameters could support to draw a more comprehensive understanding of the correlation of dynamics of environmental variables for mangrove snail population changes.

Assessment of water quality and identification of priority areas for intervention in Guanabara Bay basin, Rio de Janeiro, Brazil, using nonparametric and multivariate statistical methods.

The Guanabara Bay hydrographic region (GBHR) has served as a central hub for human settlement and resource utilization throughout Brazil's history. However, the region's high population density and intense industrial activity have come at a cost, leading to a significant decline in water quality. This work aimed to identify homogeneous regions in GBHR according to water quality parameters in dry and rainy periods. The following water quality monitoring variables were monitored at 49 gauge stations: total phosphorus (TP), nitrate (NO3-), dissolved oxygen (DO), hydrogenionic potential (pH), turbidity (Turb), thermotolerant coliforms (TCol), total dissolved solids (TDS), biochemical oxygen demand (BOD), water temperature (Tw), and air temperature (Ta). The statistical analysis consisted of determining principal components, cluster analysis, seasonal differences, and Spearman's correlation. The water quality parameter correlations were not expressively influenced by seasonality, but there are differences in the concentrations of these parameters in the dry and rainy periods. In the dry period, urban pressure on water quality is mainly due to fecal coliforms. The resulting clusters delimited areas under urban, agricultural, and forestry influence. Clusters located in areas with high demographic density showed high concentrations of TCol and TP, while clusters influenced by forestry and agriculture had better water quality. In the rainy season, clusters with urban influence showed problems with TCol and TP, in addition to some characteristics in each group, such as high TDS, NO3-, and BOD. Forested areas showed high DO, and clusters under agricultural influence had higher concentrations of TCol, BOD, and NO3- concerning forested regions. The troubling state of sanitation in GBHR occurs in metropolitan regions due to lack of a formal sanitation system.

Potential impact of climatic factors on malaria in Rwanda between 2012 and 2021: a time-series analysis

BackgroundMalaria remains an important public health problem, particularly in sub-Saharan Africa. In Rwanda, where malaria ranks among the leading causes of mortality and morbidity, disease transmission is influenced by climatic factors. However, there is a paucity of studies investigating the link between climate change and malaria dynamics, which hinders the development of effective national malaria response strategies. Addressing this critical gap, this study analyses how climatic factors influence malaria transmission across Rwanda, thereby informing tailored interventions and enhancing disease management frameworks.MethodsThe study analysed the potential impact of temperature and cumulative rainfall on malaria incidence in Rwanda from 2012 to 2021 using meteorological data from the Rwanda Meteorological Agency and malaria case records from the Rwanda Health Management and Information System. The analysis was performed in two stages. First, district-specific generalized linear models with a quasi-Poisson distribution were applied, which were enhanced by distributed lag non-linear models to explore non-linear and lagged effects. Second, random effects multivariate meta-analysis was employed to pool the estimates and to refine them through best linear unbiased predictions.ResultsA 1-month lag with specific temperature and rainfall thresholds influenced malaria incidence across Rwanda. Average temperature of 18.5 °C was associated with higher malaria risk, while temperature above 23.9 °C reduced the risk. Rainfall demonstrated a dual effect on malaria risk: conditions of low (below 73 mm per month) and high (above 223 mm per month) precipitation correlated with lower risk, while moderate rainfall (87 to 223 mm per month) correlated with higher risk. Seasonal patterns showed increased malaria risk during the major rainy season, while the short dry season presented lower risk.ConclusionThe study underscores the influence of temperature and rainfall on malaria transmission in Rwanda and calls for tailored interventions that are specific to location and season. The findings are crucial for informing policy that enhance preparedness and contribute to malaria elimination efforts. Future research should explore additional ecological and socioeconomic factors and their differential contribution to malaria transmission.

Algal diversity and its relationship with seasonal variation of water quality in Gajedi Lake, Rupandehi District (Nepal)

The current study focuses on the algal diversity of Gajedi Lake in different seasons in connection to the lake's water quality indicators. Algae and water samples were collected from eight peripheral sites of the lake in summer, rainy, and winter seasons in 2021. The water temperature, conductivity, total dissolved solids, hardness, alkalinity, phosphorus, free CO2, and dissolved oxygen were recorded as high during the summer season while water pH was high during the rainy season. Altogether 93 species of algae were reported under 52 genera, 30 families, 7 classes and 6 phyla in this study. The largest phylum was Bacillariophyta (44.08%) followed by Chlorophyta (17.20%), Euglenozoa (10.97%), Cyanobacteria (12.90%), Charophyta (10.75%) and Miozoa (1.07%). The Shannon-Weiner diversity index indicated high abundance during the summer season, with more evenly distributed algal species. More algal species were recorded in the winter season. Trachelomonas, Navicula, and Nitzschia were dominant genera during summer; Anagostidinema, Desmodesmus, and Pinnularia were dominant during rainy; and Trachelomonas, Tetradesmus, and Gomphonema were dominant during winter. The redundancy analysis ordination showed that the algal composition varied along with the seasonal changes in physico-chemical parameters. Temperature, pH, and conductivity were thus identified as significant factors influencing species richness.

Exploring Stormwater Best Management Practices for Urban Flood Reduction in Khulna City of Bangladesh Using PCSWMM

Khulna City Corporation (KCC), located in a low-lying area in southwestern Bangladesh, has been suffering from frequent water logging in the rainy season almost every year. This situation is intensified due to rapid urbanization and the impact of climate change, which have consequently created numerous problems in KCC related to stormwater management issues that require immediate consideration. Therefore, the current study aims to explore stormwater management problems in KCC and find possible countermeasures through different best management practices. Stormwater management must be incorporated into urban design and development, particularly in densely populated urban areas like KCC. In Ward No. 30 of KCC, controlling stormwater is a vital concern due to heavy rainfall, a lack of proper drainage infrastructure, unplanned growth, extensive land cover areas, etc. In the current study, the most widely used Personnel Computer Storm Water Management Model (PCSWMM) software was adopted to evaluate the city's current stormwater management practices and develop a long-term stormwater management strategy. A reconnaissance investigation of the existing states of the soil, drainage, and outlet infrastructures was conducted. The study area (KCC Ward No. 30) was then divided into many small catchments in the ArcGIS platform, and areas of each sub-catchment were identified. To determine the percentage of impervious area and the elevation of the study area, the land use and land cover (LULC) map and the digital elevation model (DEM) were generated using the ArcGIS software. All the aforementioned parameters were then entered into the PCSWMM software, and simulations were performed for various rainfall durations using different best management practices. The PCSWMM simulation provided the results of runoff, infiltration, peak runoff, floods, or surcharges at every drainage node or discharge point in the existing and altered drainage system of the study area due to the occurrence of extreme rainfall. The results indicate that various best management practices, increasing the slope, reducing the roughness of the drainage systems, reducing imperviousness, permitting more infiltrations, and promoting green infrastructure, are highly effective in controlling urban flooding or surcharges in the study area caused by the occurrence of extreme rainfall in the future. The findings of this study are expected to be supportive to policymakers, urban planners, and water managers in implementing and promoting sustainable and climate-resilient urban drainage infrastructures to tackle stormwater management problems in the KCC area. Journal of Engineering Science 15(1), 2024, 107-118

Karakteristik Hidraulik Banjir Bendung Karet Sungai Juwana Kabupaten Pati

Pati Regency, Central Java Province is an area that frequently experiences floods, including tidal floods and flash floods during the rainy season. The Pemali-Juana River Basin Center has planned the construction of a rubber weir which will be built in 2022-2024 to overcome this problem. It is hoped that this rubber weir will be a solution for controlling floods and as a water storage system during the dry season. This research aims to model the hydraulic characteristics of the flow in Karet Juwana Dam under flood conditions (Q10, 20, 25, 50, and 100 years). Modeling of flow hydraulic characteristics using HEC-RAS 5.0.3 software. The modeling results show that when the rubber weir expands, maximum backwater occurs for 2.26 km upstream of the weir. The water level above the rubber weir is 1.0 meters with flow speeds upstream and downstream of the weir threshold of 0.40 m/s and 0.66 m/s respectively. Controlling flood levels against overtopping can be optimal if the water level is 0.60 meters above the crest. Hydraulically, the simulation results show that a deflation speed of 0.2 meters/minute can control overtopping optimally.

Cattle exclusion increases encounters of wild herbivores in Neotropical forests

Abstract Ongoing habitat loss and species extinctions require managers to implement and quantify the effectiveness of conservation actions for protecting biodiversity. Fencing, when done properly, is an important management tool for conservation in landscapes where wildlife and domestic animals co‐occur, potentially enhancing habitat use through selective exclusion of domestic species. For instance, the fencing of forest patches in the Neotropics is expected to reduce the degradation of understory vegetation by cattle, releasing these resources for the native community of browsers and fruit consumers. Here, we implemented an ecological experiment using a before‐after control‐impact design to quantify the effect of cattle exclusion on encounter probability of the native community of browsers and fruit consumers, and percent ground cover in multifunctional landscapes of the Colombian Orinoquía. We built 14 km of wildlife‐permeable fences along forest edges in four forest patches (i.e. blocks) containing control and fenced (treatment) sites. We installed 33 camera traps to obtain information about wildlife and cattle encounter probabilities, before and after the fences were constructed. We used Bayesian generalised linear mixed effects models to quantify the effect of fences via the interaction between the time period (before and after the fences were built) and treatment (control or fenced sites). Fencing was effective at reducing encounter probabilities of cattle in the treated sites, and it had a positive impact on relative encounter probabilities of four of seven studied wildlife species (herbivores including the black agouti [dry season only], lowland tapir [dry season only] and spotted paca [both seasons] and an omnivore, the South American coati [rainy season only]). The effect of fencing was negative for the collared peccary but only during the dry season. No statistically significant effect was detected for the white‐lipped peccary or white‐tailed deer. Synthesis and applications: We provide experimental evidence that fences are effective at selectively excluding cattle and increasing encounter rates of wild browsers and fruit consumers in forest patches where these species co‐occur with cattle. Our results highlight an important application of fencing ecology in Neotropical forests, where the implementation of wildlife‐permeable fences is feasible due to smaller body sizes of wildlife compared to domestic animals such as cattle.

Characteristics and Indicative Significance of Groundwater Stable Isotopes in the Loess Plateau at the Regional Scale

Regional groundwater recharge is a critical scientific issue for sustainable groundwater resource development and management. However, spatial variations in groundwater recharge in the Loess Plateau （LP） remain poorly understood. To fill this knowledge gap, a systematic sampling campaign and stable isotope analysis were carried out for groundwater （shallow aquifer） in 13 major catchments during July 2019. The main objectives of this study were： ① to understandthe spatial distribution and influencing factors of stable isotopes in groundwater and ② to reveal the groundwater recharge sources and pathways and their spatial variations, combined with the precipitation stable isotope datasets. Stable isotopes in groundwater had poor spatial variations at the regional scale； however, they became isotopically depleted with the increase in annual average precipitation on the catchment scale （r = -0.87）. Compared with the stable isotope of precipitation, stable isotopes of groundwater were generally depleted and were similar to the precipitation of the rainy season （July-September）. These together indicated that there was pronounced seasonality of groundwater recharge, and the main recharge period was the rainy season. In particular, the recharge seasonality index （δP/G） was closely related to the catchment's average annual precipitation （r = -0.77） and leaf area index （r = -0.63）. In addition, groundwater lc-excess was generally negative, with the catchment-mean value ranging from -4.3‰ to -0.7‰. Hydrologically, this indicated that groundwater recharge pathways （ratio of matrix flow vs. preferential flow） were different among these catchments, which should be quantitatively determined by combining the saturated zone （groundwater） and the unsaturated zone （soil） in future work. Our findings can improve the understanding of groundwater recharge in LP and provide a scientific basis for sustainable management of groundwater resources at the regional scale.

Predictability and prediction skill of summertime East/Japan Sea surface temperature events

The East/Japan Sea (EJS), a marginal sea of the Northwestern Pacific, is one of the ocean regions showing the most rapid warming and greatest increases in ocean heatwaves over the last several decades. Predictability and skillful prediction of the summer season EJS variability are crucial, given the increasing severity of ocean temperature events impacting fisheries and reinforcing climate conditions like the East Asian rainy season, which in turn affects adjacent high-population density areas over East Asia. We use observations and the Geophysical Fluid Dynamics Laboratory (GFDL) Seamless System for Prediction and Earth System Research (SPEAR) seasonal forecast system to investigate the summertime EJS Sea Surface Temperature (SST) predictability and prediction skill. The observations and seasonal prediction system show that the summer season EJS SST can be closely linked to the previous winter air-sea coupling and predictable 8–9 months in advance. The SPEAR seasonal prediction system demonstrates skillful forecast of EJS SST events from summer to late fall, with added skill for long-lead forecasts initialized in winter. We find that winter large-scale atmospheric circulations linked to Barents Sea variability can induce persistent surface wind anomalies and corresponding northward Ekman heat transport over the East China Sea. The ocean advection anomalies that enter the EJS in prior seasons appear to play a role in developing anomalous SST during summer, along with instantaneous atmospheric forcing, as the source of long-lead predictability. Our findings provide potential applications of large-scale ocean-atmosphere interactions in understanding and predicting seasonal variability of East Asian marginal seas.

Drivers of microbial carbon biomass variability in two oceanic regions of the Gulf of Mexico

The microbial plankton community is an integral part of the pelagic ecosystem. It hosts essential functional groups that play a vital role in organic carbon production, release, uptake, and degradation within open-ocean ecosystems. Given its significance, carbon biomass estimates are urgently needed, especially in oligotrophic regions, to provide and enhance our knowledge of biogenic carbon pools. They also aid in validating biogeochemical models that characterize the functioning of these extensive marine ecosystems within the global carbon cycle. This study addresses the temporal variability of microbial community biomass in two oceanic zones: the west-central (Perdido) and southern (Coatzacoalcos) areas of the Gulf of Mexico. During three seasonally contrasting periods (nortes, rainy, and dry seasons), seawater samples were collected from the euphotic zone in both regions to estimate the carbon biomass of different pico- (<2–3 µm), nano-, and microplankton groups (>3–200 µm). Carbon biomass assessments for the microbial groups were based on their abundance and carbon conversion factors. Overall, we found a significant contribution of pico-prokaryotic components (heterotrophic bacteria, Prochloroccocus, and Synechoccocus) to the total microbial carbon stock of the euphotic zone (84–89 % global estimates). The finding suggests these microorganisms are key functional groups that drive carbon production and fate in the Gulf of Mexico ecosystem. Pico-cyanobacteria, especially Prochloroccocus, were the dominant primary producers (68–82 % total autotrophic carbon), mainly in the upper layer of the oligotrophic euphotic zone. This vertical pattern implies that the deep chlorophyll-a maximum (DCM) depth level was unrelated to a net increase in phytoplankton biomass in the three study periods. The distribution of microbial carbon biomass exhibited striking differences associated with winter mixing (the nortes season), high river discharge accompanied by cross-shelf transport (the rainy season), and the dynamics of mesoscale structures. Ecological aspects, such as the habitat preference of the organisms and the seasonal complementary development of mixotrophic and heterotrophic grazers and their prey, were also essential drivers in regulating the microbial carbon pool of both oceanic regions. The microbial carbon assessments conducted in this study contribute to identifying and quantifying key planktonic functional groups involved in the biogeochemical carbon cycle in the Gulf of Mexico open-ocean ecosystem.

Implementasi Internet of Things pada Otomasi Pemberian Pakan Ayam Ras Petelur

Adequate nutrition affects the quality and quantity of egg production which has an impact on the profitability of laying hen breeders. Rizqie Farms experienced problems with the management of feeding laying hens, when the rainy season and open cage conditions made feeding irregular. It is important to be disciplined in feeding layer chickens on time at the same time as a research ur-gency, so that the chickens do not become stressed so that discipline in feeding management increases the quality and quantity of egg production. The design thinking method as a meth-od-ology for completing the creation of Android smartphone tools and applications. The com-pletion stages start with empathize, define, ideate, prototype and test. The materials used to make the tool are ESP32 DEVKIT V1 S2, Ultrasonic Sensor, Servo driving droplet feed, Power Source/Supply 12v 1A, Stepper Motor Driver l928n, Stepper Motor Nema 17 20nm, DS3231 RTC Module (timer), Arduino Uno R3, Buzzer / Speaker, LCD 1062 16x2 with I2c port. Sensor data connected to the ESP32 DEVKIT V1 S2, Ultrasonic Sensor, Servo drive is converted to an Android smartphone as a monitoring medium. Monitoring is carried out via a mobile application, with the Internet of Things connected to the device as an internet-based communication medium. Feeding equipment testing had an average delay of 40.2 seconds and MSE 0,0514. Black box testing was carried out to test the functionality of the monitoring application on 5 users with a percentage of 100%.

Effect of Cultivation Techniques in The Dry and Rainy Seasons on The Quality of The Seaweed Caulerpa racemosa

The seaweed Caulerpa racemosa has great potential to be developed because it has economic value and potential as a functional food. This seaweed contains nutrients, including protein, carbohydrates, polyunsaturated fatty acids, fiber minerals, and antioxidants. The availability of seaweed is still very dependent on nature and has not been appropriately cultivated. The planting season and appropriate cultivation methods will influence seaweed's quality/nutritional content. This research aims to analyze the nutritional content of seaweed C. racemosa cultivated in different growing seasons. The research method used a floating raft system with a completely randomized design and a factorial pattern carried out in two seasons, namely the dry and rainy seasons. Proximate analysis was carried out to determine the nutritional composition of seaweed C. racemosa, including protein, crude fiber, water, ash, fat, and carbohydrate (NFE). Next, it was analyzed using ANOVA with a further test with Tukey. The research results showed differences in the nutritional composition of seaweed C. racemosa from each treatment cultivated in the dry and rainy seasons. The nutritional composition of seaweed C. racemosa best treatment is found in the plant spacing of 30 cm with a depth of 50 cm in the dry season with the nutritional content namely protein (13.8%), NFE (20.75%), crude fiber (15.71%), a fluctuating fat content of 0.16-1.42%, highest ash (34.69%), water content (35%), moderate in the rainy season namely: protein (10.8%), BETN (10.78%), crude fiber (12.33%), fat content fluctuates (0.18-1.06%), highest ash (30.21%), water content (41.01%).

A case-control study on risk factors for visceral leishmaniasis in West Pokot County, Kenya.

Visceral leishmaniasis (VL) is a severe parasitic disease transmitted by phlebotomine sandflies. VL is endemic in West Pokot County, Kenya, where effective strategies to interrupt transmission are impeded by the limited understanding of VL risk factors. Therefore, this case-control study aimed to explore environmental, behavioural and household determinants of VL in West Pokot. From November 2022 to January 2023, a structured questionnaire was administered to 36 symptomatic primary VL cases attending Kacheliba Sub-County Hospital in West Pokot and to 50 healthy controls from local villages. The VL status of all participants was confirmed using an rK39 rapid diagnostic test. Associations between questioned determinants and VL were investigated by means of age-corrected univariate logistic regression analysis. Significant associations were found between VL and housing characteristics, such as window presence and floor type. VL cases more frequently reported the presence of cattle, dogs and sheep in their house yards. VL was also associated with cutting down trees in the house yard and house proximity to several Acacia tree species. Furthermore, outdoor activities, including travelling outside the residence for more than 2 weeks, activities near termite mounds, and forest activities during the rainy season, increased the risk of VL. This work reports a number of previously undescribed risk factors for VL in the understudied West Pokot focus. The results suggest VL transmission occurs both peri-domestically at night and outdoors during the day, particularly when sandfly resting sites are disturbed. Our findings warrant further research into sandfly ecology and potential zoonotic parasite reservoirs in West Pokot.

Assessment of the trophic status and water quality in an urbanised tropical estuary, Brazil.

ABSTRACT The Anil River estuary (ARE), which is crucial for São Luís Island's socioeconomic well-being, faces substantial human pressure due to its urban location, hastening the eutrophication process. This study, which was conducted from 2022 to 2023, aimed to assess trophic levels across the ARE. Using a multiparametric probe, we analysed the pH, temperature, dissolved oxygen, oxygen saturation, salinity, and total dissolved solids quarterly during the rainy and dry seasons at six sampling points. The nutrient analysis included nitrite, nitrate, ammonium ions, phosphate, total nitrogen (TN), and total phosphorus (TP). Trophic index (TRIX) values categorised the ARE as eutrophic (sector 1) or hypereutrophic (sector 2). The dry season exhibited relatively high trophic levels, indicating that the ARE was hypereutrophic. Sector 2, influenced by concentrated nutrients and chlorophyll-a, exhibited increased trophic status from domestic and industrial effluent discharge. Rainy season data at the downstream from the point 3 recorded the maximum DIN:DIP ratio, indicating phosphorus limitation. Monitoring estuarine trophic states is vital for kerbing eutrophication and preserving local biodiversity in the anil river estuary.