Compliance With Guidelines on Seasonal Malaria Chemoprevention in Kwara State, Northcentral Nigeria.

BACKGROUND: Seasonal malaria chemoprevention (SMC) is an effective strategy for reducing malaria morbidity and mortality in children aged 3-59 months in areas with seasonal malaria transmission. Sulphadoxine-pyrimethamine plus amodiaquine is given to an eligible child at monthly intervals during the peak malaria transmission season. The aim of this study was to determine the level of compliance with SMC guidelines by community drug distributors during SMC implementation in Kwara State. METHOD: Caregivers of eligible children from six Local Government Areas were interviewed using a structured questionnaire on the KoboCollect app downloaded on hand-held android devices. The questionnaire was composed of questions on caregiver's demographics, SMC drug administration, and adherence to SMC protocol. RESULTS: A total of 1,314 caregivers were interviewed, most of them were female 1076 (81.9%), married 1200 (91.3%) and literate 795 (60.5%). The mean SMC coverage for the 4 cycles was 1183(88.5%). SMC information was received by 1166 (88.7%) of caregivers. Most of the caregivers 1166 (88.7%) heard about SMC. Overall, SPAQ administration was directly observed in most cases 1169 (91.5%), second dose was given 1226 (96.0%) and drugs were fully ingested 1140(89.3%). Poor compliance was observed in home visits by lead mothers 988 (77.4%). The report of adverse drug reactions was low 132 (10.3% [95% CI: 8.8-12.3%]), the commonest being severe vomiting 50 (37.9%). There were significant (P<0.05) variations in SMC implementation across the 6 LGAs in virtually all the performance indicators. SPAQ administration to over-age children was low 128 (10.0%). CONCLUSION: Overall, the compliance with SMC implementation guidelines in Kwara state was good though significant differences in performance were observed across the six LGAs. Home visits by lead mothers were generally poor. The self-reported coverage of SMC by caregivers was commendable.

CONTEXTE: La chimioprévention saisonnière du paludisme (CSP) est une stratégie efficace pour réduire la morbidité et la mortalité liées au paludisme chez les enfants âgés de 3 à 59 mois dans les zones à transmission saisonnière du paludisme. La sulfadoxine-pyriméthamine associée à l'amodiaquine est administrée à un enfant éligible à intervalles mensuels pendant la saison de transmission maximale du paludisme. L'objectif de cette étude était de déterminer le niveau de conformité aux directives de la CSP par les distributeurs de médicaments communautaires lors de la mise en œuvre de la CSP dans l'État de Kwara. MÉTHODE: Les aidants des enfants éligibles de six zones de gouvernement local ont été interrogés à l'aide d'un questionnaire structuré sur l'application KoboCollect sur des appareils android portables. Le questionnaire comprenait des questions sur les caractéristiques démographiques des aidants, l'administration des médicaments de la CSP et l'adhésion au protocole de la CSP. RÉSULTATS: Au total, 1 314 aidants ont été interrogés, la plupart étaient des femmes 1 076 (81,9 %), mariées 1 200 (91,3 %) et alphabétisées 795 (60,5 %). La couverture moyenne de la CSP pour les 4 cycles était de 1 183 (88,5 %). La plupart des aidants 1 166 (88,7 %) avaient entendu parler de la CSP. Dans l'ensemble, la première administration de SPAQ a été observée directement dans la plupart des cas 1 169 (91,5 %), la deuxième dose a été administrée par 1 226 (96,0 %) aidants et les médicaments ont été entièrement ingérés sans cracher partiellement ou totalement par 1 140 (89,3 %) enfants. Une mauvaise conformité a été observée lors des visites à domicile par les mères responsables 988 (77,4 %). Le signalement des réactions indésirables aux médicaments était faible 132 (10,3 % [IC à 95 % : 8,8-12,3 %]), la plus courante étant les vomissements sévères 50 (37,9 %). Des variations significatives (P<0,05) dans la mise en œuvre de la CSP ont été observées dans les 6 LGAs pour pratiquement tous les indicateurs de performance. L'administration de SPAQ aux enfants plus âgés était faible 128 (10,0 %). CONCLUSION: Dans l'ensemble, la conformité aux directives de mise en œuvre de la CSP dans l'État de Kwara était bonne bien que des différences significatives dans les performances aient été observées dans les six LGAs. Les visites à domicile par les mères responsables étaient généralement mauvaises. La couverture autodéclarée de la CSP par les aidants était louable. MOTS-CLÉS: Chimioprévention saisonnière du paludisme, SPAQ, Conformité, Enfants, Centre-nord du Nigeria, Saison des pluies.

Among-species variation in flower size determines florivory in the largest tropical wetland.

PREMISE: Flower damage caused by florivores often has negative consequences for plant reproduction. However, the factors affecting plant-florivore interactions are still poorly understood, especially the role of abiotic factors and interspecific variation in florivory within ecosystems. Thus, the patterns of florivory levels and its consequences for plant communities need to be investigated further. METHODS: We assessed the influence of abiotic factors related to climatic seasonality, of phylogenetic relationships among plants, and of functional attributes associated with attractiveness to pollinators on florivory incidence and intensity in the Pantanal, the world's largest tropical wetland. Between December 2020 and November 2021, the percentage of flowers attacked (incidence) and petal area removed (intensity) by florivores were examined in 51 species from 25 families, considering flowering season, the substrate where the plants occur, and flower attributes as potentially determining factors on florivory levels. RESULTS: Phylogeny and environmental factors did not have a significant influence on florivory. The only determinant of interspecific variation in florivory incidence and intensity was flower size, where larger flowers experienced higher florivory levels regardless of season and substrate, while flower arrangement and color were not significant factors. CONCLUSIONS: Our study is one of the first to estimate the community-wide effects of biotic and abiotic factors on both the incidence and the intensity of florivory. The magnitude of this plant-florivore interaction may reduce reproductive success and entail selective pressures on plant attractiveness to pollinators.

Influence of monsoon anomalies on intra-annual density fluctuations of Chinese pine in the Loess Plateau.

In the past few decades, the East Asian summer monsoon (EASM) has experienced an unprecedented weakening, exacerbating drought in northern China, especially in the monsoon margin area. Improving our understanding of monsoon variability will benefit agricultural production, ecological construction, and disaster management. Tree-ring is widely used as proxy data for extending the monsoon history. However, in the East Asian monsoon margin, the tree-ring width were mostly formed before the rainy season, thus may have limited ability to indicate the monsoon variability. Intra-annual density fluctuations (IADFs) can provide higher resolution information on tree growth as well as evidence of short-term climate events. Here, we used Chinese pine (Pinus tabuliformis Carr.) samples from the eastern edge of the Chinese Loess Plateau (CLP), where the climate is deeply affected by monsoon, to investigate the response of tree growth and IADFs frequency to climate variation. We show that tree-ring width and IADFs record significantly different climatic signals. The former was mainly affected by moisture conditions at the end of the previous growing season and the current spring. While the latter was common in years when severe droughts occurred in June and July, especially in June. This period coincides with the onset of the EASM, so we further analyzed the relationship between IADFs frequency and the rainy season. Both correlation analysis and the GAM model suggest that the frequent occurrence of IADFs may be related to the late start of the monsoon rainy season, meaning that we have found a new indicator in tree-ring records that can capture monsoon anomalies. Our results provide further insight into drought variation in the eastern CLP, which also implicates the Asian summer monsoon dynamic.

Impact of temperature on hospital admission for acute lower respiratory infection (ALRI) among pre-school children in Ho Chi Minh City, Vietnam.

Changes in ambient temperature have been reported as an important risk factor for respiratory diseases among pre-school children. However, there have been few studies so far on the effects of temperature on children respiratory health in developing countries including Vietnam. This study examined the impact of short-term changes in ambient temperature on hospital admissions for acute lower respiratory infection (ALRI) among children aged less than 5 years old in Ho Chi Minh City (HCMC), Vietnam. Data on daily hospital admissions from 2013 to 2017 were collected from two large paediatric hospitals of the city. Daily meteorological data of the same period were also collected. Time series analysis was performed to evaluate the association between risk of hospitalisations and temperatures categorised by seasons, age, and causes. We found that a 1 °C increase in maximum temperature was associated with 4.2 and 3.4% increase in hospital admission for ALRI among children 3-5 years old during the dry season and the rainy season, respectively. Surprisingly, in the rainy season, a rise of 1°C diurnal temperature range (DTR) was significantly associated with a decrease from 2.0 to 2.5% risk of hospitalisation for ALRI among children <3 years old. These findings suggested that although high temperature is a risk factor for hospital admissions among children in general, other modifiable factors such as age, exposure time, air conditioning usage, wearing protective clothing, socioeconomic status, and behaviour may influence the overall effect of high temperature on hospital admissions of children <5 years old in HCMC. The findings of this study have provided evidence for building public health policies aimed at preventing and minimizing the adverse health effects of temperature on children in HCMC.

Changes in microbial communities at different soil depths through the first rainy season following severe wildfire in North China artificial Pinus tabulaeformis forest.

Wildfire could result in dramatic changes to soil temperatures and environments, with immediate, short- or long-lasting impacts on soil microbes. However, relatively little research has documented how fire disturbance, soil depth, time variation and their interactions affect soil microbial communities in wet conditions. This study investigated a severe wildfire influenced on bacterial and fungal communities at four soil depths (0-5, 5-10, 10-15 and 15-20 cm) after two quarters (with similar precipitation and exactly during the rainy season). Soil sampling was conducted in a burned site relative to an undisturbed contiguous site in the North China artificial Pinus tabulaeformis forest. Results indicated that fire had significant effects on bacterial and fungal richness, diversity, composition and structure, including most impacts on the surface mineral soil (0-5 cm) within the first period post-fire and minor impacts on the subsoils (5-20 cm) up to the second period. The microbial richness and some dominant taxa in the undisturbed soils changed with time and depth, suggesting spatiotemporal variation in soil microbial communities although the effects of rainfall were weakened. These differences in microbes between burned and undisturbed soils were mainly driven by soil pH, whereas organic matter and available potassium mediated the distribution of microbial communities along depth and time, respectively. In addition, fungal community was more sensitive to fire and time than bacterial community but an opposite result was found in depth. Nevertheless, soil microbes showed some signs of adaptation to fire. This work advocate that non-intervention should be considered in the short term after a fire or low-intensity water replenishment in the case of aridity.

Changes in cambial activity are related to precipitation patterns in four tropical hardwood species grown in Indonesia.

PREMISE: Cambial activity in some tropical trees varies intra-annually, with the formation of xylem rings. Identification of the climatic factors that regulate cambial activity is important for understanding the growth of such species. We analyzed the relationship between climatic factors and cambial activity in four tropical hardwoods, Acacia mangium, Tectona grandis, Eucalyptus urophylla, and Neolamarckia cadamba in Yogyakarta, Java Island, Indonesia, which has a rainy season (November-June) and a dry season (July-October). METHODS: Small blocks containing phloem, cambium, and xylem were collected from main stems in January 2014, October 2015 and October 2016, and examined with light microscopy for cambial cell division, fusiform cambial cells, and expanding xylem cells as evidence of cambial activity. RESULTS: During the rainy season, when precipitation was high, cambium was active. By contrast, during the dry season in 2015, when there was no precipitation, cambium was dormant. However, in October 2016, during the so-called dry season, cambium was active, cell division was conspicuous, and a new xylem ring formation was initiated. The difference in cambial activity appeared to be related to an unusual pattern of precipitation during the typically dry months, from July to October, in 2016. CONCLUSIONS: Our results indicate that low or absent precipitation for 3 to 4 months induces cessation of cambial activity and temporal periodicity of wood formation in the four species studied. By contrast, in the event of continuing precipitation, cambial activity in the same trees may continue throughout the year. The frequency pattern of precipitation appears to be an important determinant of wood formation in tropical trees.

The worm burden of tracer kids and lambs browsing heterogeneous vegetation is influenced by strata harvested and not total dry matter intake or plant life form.

This study assessed the effect of total dry matter intake (DMI), plant life form and strata harvested on the gastrointestinal nematode (GIN) worm burdens of tracer kids and lambs browsing heterogeneous vegetation during the rainy season (August-November). The rainy season was divided into 6 2-week periods (P1-P6), and environmental conditions (rainy days, rainfall, temperature and humidity) were recorded daily. Five pairs each of tracer kids and tracer lambs raised free of GIN infections were used. Every 15 days, different pairs of kids and lambs were introduced to a 2.2-ha plot and co-grazed with a flock of 30 sheep and 70 goats for a period of 3 weeks. Feeding behaviour of each pair of tracers was measured in weeks 2 and 3. The continuous bite monitoring method was used to estimate total DMI, DMI of plant life forms and DMI from plants of different strata. After each 3-week period, the tracer pair was maintained indoors for 28 days and necropsied on day 29 to recover the worm burden. The feeding behaviour of the tracers was compared between periods (P2-P6) and between kids and lambs. The differences in the worm burdens of the tracers between periods were not associated with total DMI or DMI from plant life forms. Worm burdens were highest during P5 and P6 in tracer kids and lambs (P < 0.05), suggesting a build-up of infective larvae in the tropical deciduous forest (TDF). The lower worm burdens of tracer kids compared with lambs (P < 0.05) seemed to be associated with less low- and more medium-stratum ingestion.

Interspecific difference in downstream migratory season between two tropical eels, Anguilla celebesensis and Anguilla marmorata.

Downstream-migrating Anguilla celebesensis eels were predominant relative to Anguilla marmorata in October, November, December, January and February (75.9-92%), while no A. celebesensis occurred and A. marmorata were predominant in May and July (96-100%), at the outlet of Poso Lake, Sulawesi Island, Indonesia. Merging these results with those from published data suggests that most A. celebesensis start downstream migration during the early to middle rainy season, and A. marmorata migrate almost year-round with a peak from the late rainy to middle dry season.

Effect of supplementation of beef cattle with different protein levels and degradation rates during transition from the dry to rainy season.

The objective of this study was to evaluate the effect of increasing the supply of protein with different degradation rates on the performance and metabolism of growing Nellore cattle reared on Brachiaria brizantha cv. Marandu pasture during the transition period from the dry to rainy season. The experiment was installed on an area of 34 ha, divided into 12 paddocks with an average area of 2.85 ha. In the performance evaluation were utilized 72 recently weaned, non-castrated Nellore cattle with an initial body weight (BW) of 199 kg (SEM = 16). The following supplements were used: energy protein supplement containing 25% crude protein (CP) (C-25) and energy protein supplements containing 40% CP with one third highly degradable CP and two thirds poorly degradable CP (40-1/3NPN), one half highly degradable CP and one half poorly degradable CP (40-1/2NPN), and two thirds highly degradable CP and one third poorly degradable CP (40-2/3NPN). Higher protein degradation rates reduced supplement intake (P < 0.01). In the first period, animals consuming supplement 40-1/3NPN exhibited higher average daily gain (ADG) (0.30 kg/day), similar to that of animals receiving supplement 40-1/2NPN (P = 0.04). In the second period, supplement 40-2/3NPN resulted in lower ADG (0.19 kg/day less than the other supplements). There was no effect of supplement on animal performance in the third period (P > 0.10), when ADG was 0.56 kg/day. In conclusion, the response to supplementation is associated with interactions with characteristics of the forage canopy. Supplementation with a true protein source will be beneficial only during the early stage of the dry-rainy season transition period.

The effects of energy and protein supplementation strategy and frequency on the performance of beef cattle that grazed on Tanzania grass pastures during the rainy season.

The aim of the present study was to evaluate the different supplementation strategies for finishing Nellore beef cattle on pastures of Tanzania guinea grass (Panicum maximum Jacq. 'Tanzania'). The experiment was performed in a 12 ha area divided into 12 paddocks of 1 ha each. Forty-eight, 2-year-old, non-castrated Nellore cattle with an initial body weight (BW) of 384 kg (SEM = 21) were used in this study. The following supplementation strategies were evaluated: (1) mineral supplement supplied once per week (MS), (2) energy and protein supplement with intake regulator (2 g/kg BW) supplied once per week (EPS1), (3) energy and protein supplement (7 g/kg BW) supplied daily (EPS2), and (4) energy and protein supplement (7 g/kg BW) supplied three times per week (EPS3). The average daily gain (ADG) of animals receiving EPS3 was 0.177 kg/day higher than those receiving EPS1 (p < 0.01), 0.233 kg/day higher than the MS group, and not significantly different from EPS2. Animals in MS and EPS1 groups exhibited the lowest ADG. The ADG was not significantly different between EPS1 and EPS2 animals, but was 0.203 kg/day higher for EPS2 animals than for MS. Animals receiving only mineral supplementation spent more time grazing than the other supplementation groups tested (p < 0.01). We therefore conclude that Tanzania guinea grass is nutritionally limited and can be amended using supplements, thereby increasing animal performance. Animal performance was higher with increased protein and energy supplementation (7 g/kg BW), independent of the frequency with which supplements were administered.

Possible Role of Rickettsia felis in Acute Febrile Illness among Children in Gabon.

Rickettsia felis has been reported to be a cause of fever in sub-Saharan Africa, but this association has been poorly evaluated in Gabon. We assessed the prevalence of this bacterium among children <15 years of age in 4 areas of Gabon; the locations were in urban, semiurban, and rural areas. DNA samples from 410 febrile children and 60 afebrile children were analyzed by quantitative PCR. Overall, the prevalence of R. felis among febrile and afebrile children was 10.2% (42/410 children) and 3.3% (2/60 children), respectively. Prevalence differed among febrile children living in areas that are urban (Franceville, 1.3% [1/77]), semiurban (Koulamoutou, 2.1% [3/141]), and rural (Lastourville, 11.2% [15/134]; Fougamou, 39.7% [23/58]). Furthermore, in a rural area (Fougamou), R. felis was significantly more prevalent in febrile (39.7% [23/58]) than afebrile children (5.0% [1/20]). Additional studies are needed to better understand the pathogenic role of R. felis in this part of the world.

Effects of age and season on haematological parameters of donkeys during the rainy and cold-dry seasons.

The aim of the study was to investigate the effects of age and season on haematological parameters of donkeys at rest during the rainy and cold-dry seasons. Thirty healthy donkeys divided into three groups based on their age served as the subjects. During each season, blood sample was collected from each donkey thrice, 2 weeks apart, for haematological analysis, and the dry-bulb temperature (DBT), relative humidity (RH) and temperature-humidity index (THI) were obtained thrice each day during the experimental period using standard procedures. During the rainy season, the mean DBT (33.05 ± 0.49 °C), RH (73.63 ± 1.09 %) and THI (84.39 ± 0.71) were higher (P < 0.0001) than the corresponding values of 24.00 ± 0.44 °C, 36.80 ± 0.92 % and 64.80 ± 0.62, during the cold-dry season. Packed cell volume (PCV), erythrocyte count [red blood cell (RBC)], haemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), platelet count (PLT), leucocyte count [white blood cell (WBC)], lymphocyte count (LYM) and neutrophil/lymphocyte ratio (N/L) were higher (P < 0.05) in adults than foals during the rainy season. The MCV, MCH, WBC, NEU, LYM and PLT of adult and yearling donkeys were higher (P < 0.05) during the rainy than the cold-dry season. The PCV, RBC, Hb, MCV, MCH, and NEU of foals were higher in the rainy than the cold-dry season. The N/L of adult and foal donkeys were higher (P < 0.05) in the rainy than in the cold-dry season. In conclusion, PCV, RBC, Hb and LYM were considerably higher in foals than yearlings or adults during the rainy season, while erythrocytic indices and platelet counts were higher in adults or yearlings than in foals in both seasons. Erythrocytic indices, PLT and N/L were higher in the rainy than the cold-dry season in adults, yearlings and foals.

Anopheles aquatic development kinetic and adults' longevity through different seasons in laboratory and semi-field conditions in Burkina Faso.

ABSTRACT: BACKGROUND: Anopheles mosquitoes are ectothermic and involved in numerous pathogen transmissions. Their life history traits are influenced by several environmental factors such as temperature, relative humidity and photoperiodicity. Despite extensive investigations of these environmental conditions on vector population ecology, their impact on the different life stages of Anopheles at different seasons in the year remains poorly explored. This study reports the potential impact of these abiotic factors on the immature and adult stages of Anopheles gambiae sensu lato during different seasons. METHODS: Environmental conditions were simulated in the laboratory using incubators to mimic the environmental conditions of two important periods of the year in Burkina Faso: the peak of rainy season (August) and the onset of dry season (December). Eggs from wild An. coluzzii and An. gambiae s.l. were reared separately under each environmental condition. For Anopheles coluzzii or An. gambiae s.l., eggs were equally divided into two groups assigned to the two experimental conditions. Four replicates were carried out for this experiment. Then, egg hatching rate, pupation rate, larval development time, larva-to-pupae development time, adult emergence dynamics and longevity of Anopheles were evaluated. Also, pupae-to-adult development time from wild L3 and L4 Anopheles larvae was estimated under semi-field conditions in December. RESULTS: A better egg hatching rate was recorded overall with conditions mimicking the onset of the dry season compared to the peak of the rainy season. Larval development time and longevity of An. gambiae s.l. female were significantly longer at the onset of the dry season compared than at the peak of the rainy season. Adult emergence was spread over 48 and 96 h at the peak of the rainy season and onset of dry season conditions respectively. This 96h duration in the controlled conditions of December was also observed in the semi-field conditions in December. CONCLUSIONS: The impact of temperature and relative humidity on immature stages and longevity of An. gambiae s.l. adult females differed under both conditions. These findings contribute to a better understanding of vector population dynamics throughout different seasons of the year and may facilitate tailoring of control strategies.

Effects of rainfall patterns in dry and rainy seasons on the biomass, ecostoichiometric characteristics, and NSC content of Fraxinus malacophylla seedlings.

With global climate change and rising temperatures, rainfall will change. The impact of global rainfall changes on ecosystems has prompted people to delve deeper into how changes in rainfall affect plant growth; Plant biomass, nutrient element content, and non-structural carbohydrate content are very sensitive to changes in precipitation. Therefore, understanding the impact of rainfall changes on seedlings is crucial. However, it is currently unclear how the seedlings of Fraxinus malacophylla Hemsl in rocky desertification areas respond to changes in rainfall. In this study, the response of biomass, nutrient accumulation, and NSC content of Fraxinus malacophylla Hemsl seedlings to different rainfall intervals and rainfall during the dry and rainy seasons was studied. Use natural rainfall duration of 5 days (T) and extended rainfall duration of 10 days(T+) as rainfall intervals; average monthly rainfall was used as the control (W), with a corresponding 40% increase in rainfall (W+) and a 40% decrease in rainfall (W-) as rainfall treatments. The research results indicate that the biomass of roots, stems, and leaves, as well as the accumulation of C, N, and P in Fraxinus malacophylla Hemsl seedlings increase with the increase of rainfall, while the soluble sugar and starch content show a pattern of first increasing and then decreasing. The biomass and nutrient accumulation of each organ showed root>leaf>stem. Except for the beginning of the dry season, prolonging the duration of rainfall in other periods inhibits the biomass accumulation of Fraxinus malacophylla Hemsl seedlings, and promotes the accumulation of C, N, and P nutrients and an increase in soluble sugar and starch content. There was a significant positive correlation (P<0.05) between the nutrient contents of C, N, and P in various organs, as well as between soluble sugar and starch content; And N: P>16, plant growth is limited by P element. These results indicate that changes in rainfall can affect the growth and development of Fraxinus malacophylla Hemsl seedlings, increasing rainfall can promote biomass and nutrient accumulation of Fraxinus malacophylla Hemsl seedlings, and prolonging rainfall intervals and reducing rainfall have inhibitory effects on them. The exploration of the adaptation of Fraxinus malacophylla Hemsl seedlings to rainfall patterns has promoted a basic understanding of the impact of rainfall changes on the growth of Fraxinus malacophylla Hemsl. This provides a theoretical basis for understanding how Fraxinus malacophylla Hemsl can grow better under rainfall changes and for future management of Fraxinus malacophylla Hemsl artificial forests in rocky desertification areas.

Survival dynamics of stick insect and the impact of environmental factors on natural fungal infection during the rainy season.

Phasmatodea, commonly known as stick insects, are recognized as noteworthy pests globally, impacting agriculture and forest ecosystems. Among them, the outbreak of Ramulus mikado has emerged as a notable concern in East Asian forests. Recently, Metarhizium phasmatodeae has been identified as utilizing stick insects as hosts. We have observed evidence of this entomopathogenic fungus infecting stick insects. Given the increase in these occurrences during the rainy period, this study investigated the relationship between the survival of R. mikado and the M. phasmatodeae infection during the rainy seasons of 2022 and 2023. We collected stick insects in two representative forests of the Republic of Korea and examined insect survival, fungal infection, and various environmental factors. No infections were detected in specimens collected in June before the rainy season, but from July onwards, both the mortality of R. mikado and the fungal infection substantially increased. By the last sampling date of each year, 75% (2022), 71.4% (2023) of the specimens were infected, and over 90% of the total individuals succumbed as a result. Fungi isolated from deceased R. mikado were successfully identified as M. phasmatodeae using morphological and taxonomic approaches. Various statistical analyses, including principal component analysis and modeling, revealed a robust association between fungal infection and the survival of stick insects. The results highlight the correlation between mass deaths of stick insects and fungal infection, particularly during the summer rainy season. These findings offer valuable insights for forecasting R. mikado population in the upcoming year and developing effective pest control strategies.

Spatiotemporal distribution and particle-water partitioning of polycyclic aromatic hydrocarbons in Bohai Sea, China.

The Bohai Sea is one of the most polluted marine areas in China with polycyclic aromatic hydrocarbons (PAHs) due to its unique hydrological and geographical environment. To investigate differences in PAH concentrations, composition, and particle-water partitioning before and after the rainy reason, water samples were collected during two surveying voyages covering most of the area of the Bohai Sea. Total and dissolved PAH concentrations were higher during the June voyage (total PAHs: 32.29 ± 15.18 ng/L, dissolved PAHs: 31.25 ± 15.26 ng/L) than the August voyage (total PAHs: 15.98 ± 6.39 ng/L, dissolved PAHs: 11.21 ± 5.59 ng/L). The opposite trend was observed for particulate PAHs (June: 1.04 ± 1.01 ng/L, August: 4.78 ± 2.96 ng/L). Among particulate PAHs, an unusually high proportion (65.07%) of low-molecular-weight (LMW) PAHs was observed during the August voyage, which was significantly higher than the proportion during the June voyage (21.86%). This high proportion was inconsistent with the general distribution of PAHs in the aquatic environment according to their physicochemical properties. The excess LMW PAHs adsorbed on suspended particulate matter arose mainly from soil affected by the petrochemical industry of the Bohai Economic Rim, and were carried with particles on runoff into the Bohai Sea during the rainy season. An estimated 5.49 t of LMW PAHs transitioned from the particulate phase to the dissolved phase during the rainy season. This transfer of LMW PAHs from coastal soil to the water column may be an important source of PAHs in the Bohai Sea.

Nitrate dynamics and source identification of rainwater in Beijing during rainy season: Insight from dual isotopes and Bayesian model.

Anthropogenic reactive nitrogen emissions have a significant impact on atmospheric chemical composition and earth surface ecosystem. As one of the most important sinks of atmospheric nitrogen, the wet deposition of nitrate (rainwater NO3-) has been widely concerned. Yet, the sources and transformation processes of wet deposited NO3- were not well revealed in megacity during rainy season in the context of global climate change. Here, we investigated the concentrations of nitrogen components and dual isotopes of rainwater nitrate collected in Beijing during July to August 2021 (rainy season). The main findings showed that the concentrations of NH4+-N, NO3--N, and NO2--N ranged 0.5- 6.7 mg L-1, 0.3- 4.5 mg L-1, and 0.05- 0.18 mg L-1, respectively, with the average relative percentages of 69 %, 29 %, and 2 %. The stoichiometry analysis of characteristic ion ratios indicated that the contribution of municipal wastes and agricultural sources to rainwater NH4+-N is relatively significant, while traffics were the major contributor of NO3--N instead of the fixed emission. Rainwater δ15N-NO3- and δ18O-NO3- presented slightly 15N-depleted characteristic compared to previous studies with the average values of -3.9 ± 3.1 ‰ and 58.7 ± 12.6 ‰. These isotope compositions suggesting an origin of rainwater NO3- from the mixing of multi-sources and was mainly generated via the pathway of OH radical oxidization. Further source apportionment of rainwater NO3- by Bayesian mixing model evaluated that traffic (30.3 %) and soil (30.3 %) emissions contributed mostly to NO3-, while the contribution of biomass burning (18.8 %) and coal combustion (20.6 %) were relatively lower. This study highlighted the important role of dual isotopes in rainwater nitrate source identification and formation processes in megacity.

Occurrence, characteristics, and factors influencing the atmospheric microplastics around Jiaozhou Bay, the Yellow Sea.

Atmospheric microplastics are attracting increasing attention as an emerging pollutant. However, research on its characteristics and influencing factors is insufficient. This study examines the characteristics and spatiotemporal distribution of atmospheric microplastics around Jiaozhou Bay, the Yellow Sea. The results showed that the dominant shapes of microplastic were fragments (61.9 %) and fibers (25.6 %), and the main types were polyethylene terephthalate (23.8 %), polyethylene (31.6 %) and cellulose (rayon, 34.9 %). The deposition rate of microplastic varied from 8.395 to 80.114 items·m-2·d-1, with a mean of 46.708 ± 21.316 items·m-2·d-1. The deposition rate was higher in the dry season than in the rainy season, indicating the influence of weather condition. The annual mass of atmospheric microplastics entering the bay was estimated to be 7.612 ± 3.474 tons. For the first time, this study reveals that atmospheric microplastics in Jiaozhou Bay change spatiotemporally due to monsoons, which pose a potential threat to marine ecosystems.

Heat Exposure Following the Rainy Season Is Associated With an Increased Risk of Cardiovascular Emergency Among the Elderly in Japan.

Background Despite the impact of heat exposure caused by global warming, few studies have investigated the hourly effects of heat exposure and the risk of cardiovascular disease (CVD) in the elderly. We examined the associations between short-term heat exposure and the risk of CVD in the elderly in Japan and evaluated possible effect-measure modifications by rainy seasons that occur in East Asia. Methods and Results We conducted a time-stratified case-crossover study. The study included 6527 residents in Okayama City, Japan, aged ≥65 years who were transported to emergency hospitals between 2012 and 2019 for the onset of CVD during and a few months after the rainy seasons. We examined the linear associations between temperature and CVD-related emergency calls for each year and for hourly preceding intervals before the emergency call during the most relevant months. Heat exposure during 1 month after the end of the rainy season was associated with CVD risk; the odds ratio (OR) for a 1° C increase in temperature was 1.34 (95% CI, 1.29-1.40). When we further explored the nonlinear association by using the natural cubic spline model, we found a J-shaped relationship. Exposures 0 to 6 hours before the case event (preceding intervals 0-6 hours) were associated with CVD risk, particularly for the preceding interval 0 to 1 hour (OR, 1.33 [95% CI, 1.28-1.39]). For longer periods, the highest risk was at preceding intervals 0 to 23 hours (OR, 1.40 [95% CI, 1.34-1.46]). Conclusions Elderly individuals may be more susceptible to CVD after heat exposure during the month after the rainy season. As shown by finer temporal resolution analyses, short-term exposure to increasing temperature can trigger CVD onset.

Increased precipitation leads to earlier green-up and later senescence in Tibetan alpine grassland regardless of warming.

It is debatable whether warming or increased precipitation primarily drives the changes of spring and autumn phenology in alpine grasslands at high elevations like the Tibetan Plateau. We aim to test the hypothesis that increased precipitation and soil moisture rather than warming significantly advance spring green-up dates (GUD) of dominant species in a semiarid alpine grassland, while both increases of temperature and precipitation delay their autumn senescence dates (SD). We conducted a 2-year manipulative experiment with infrared warming (ambient, +2 °C) and precipitation increase for each of rainfall events (ambient, +15 %, +30 %) during the growing season in a Tibetan alpine grassland. GUD and SD of three dominant species and the relevant soil temperature (ST) and moisture (SM) were observed. Rainy season onset as well as Pre-GUD or Pre-SD (30 days before GUD or SD) mean air-temperature (T-30d) and precipitation (P-30d) and relevant soil temperature (ST-30d) and moisture (SM-30d) were calculated for each experimental treatment. GUD dates of the three dominant species were advanced by increased precipitation rather than by warming, which showed a robust positive correlation with rainy season onset. SD dates were independently delayed by both increases of temperature and precipitation. There was no interactive effect of warming and increased precipitation on GUD and SD across species and years. In general, GUD had a significant negative correlation with Pre-GUD P-30d (SM-30d) but not with Pre-GUD T-30d (ST-30d), while SD showed a significant positive correlation with Pre-SD T-30d and P-30d or Pre-SD ST-30d and SM-30d. Our data support the hypothesis, indicating that spring and autumn phenology of monsoon-adapted alpine vegetation are more sensitive to precipitation change than to warming. The prolonged growing season length under increased temperature and precipitation is more depended on the delay of autumn senescence than the advance of spring green-up.