Observed Changes of Rain-Season Precipitation in China from 1960 to 2018

Precipitation during the main rain season is important for natural ecosystems and human activities. In this study, according to daily precipitation data from 515 weather stations in China, we analyzed the spatiotemporal variation of rain-season (May-September) precipitation in China from 1960 to 2018. The results showed that rain-season precipitation decreased over China from 1960 to 2018. Rain-season heavy (25 ≤ p < 50 mm/day) and very heavy (p ≥ 50 mm/day) precipitation showed increasing trends, while rain-season moderate (10 ≤ p < 25 mm/day) and light (0.1 ≤ p < 10 mm/day) precipitation showed decreasing trends from 1960 to 2018. The temporal changes of precipitation indicated that rain-season light and moderate precipitation displayed downward trends in China from 1980 to 2010 and rain-season heavy and very heavy precipitation showed fluctuant variation from 1960 to 2018. Changes of rain-season precipitation showed clear regional differences. Northwest China and the Tibetan Plateau showed the largest positive trends of precipitation amount and days. In contrast, negative trends were found for almost all precipitation grades in North China Plain, Northeast China, and North Central China. Changes toward drier conditions in these regions probably had a severe impact on agricultural production. In East China, Southeast China and Southwest China, heavy and very heavy precipitation had increased while light and moderate precipitation had decreased. This result implied an increasing risk of flood and mudslides in these regions. The advance in understanding of precipitation change in China will contribute to exactly predict the regional climate change under the background of global climate change.

Effects of Climate Variability on Queen Production and Pollen Preferences of Neotropical Bumblebee Bombus atratus in a High Andean Suburban Condition

Bombus atratus Franklin is a widely distributed bumblebee of South America. In Colombia, this species is recognized for its ability to adapt to highly disturbed habitats. However, knowledge of its ecology is poorly known, in particular conditions to ensure the long-term conservation of its populations. Identification of pollen resources is an important issue that could be used as a tool to manage and conserve bumblebees. In tropical areas, rainfall patterns could affect floral phenology and therefore the availability of pollen resources. Considering this, the present work aimed to establish the effect of extreme weather conditions (El Niño) in pollen availability, use of pollinic sources, and gyne production in B. atratus colonies. We reared and located 14 B. atratus colonies in a suburban area during a dry season (ENSO "El Niño") and a rainy season (ENSO "La Niña"). We registered time to gyne production and numbers of gynes produced per colony. We extracted pollen samples to establish both its floral origin and its relative abundance. We measured floral offer for each season. The data of pollen use per colony were utilized to perform Bipartite networks. We analyzed the production of gynes and pollen use per season with correlation models and generalized linear models. Colonies of the rainy season produced more gynes and faster. The floral diversity and offer were higher during the rainy season. Successful colonies used specific pollen sources in two seasons, independently of the floral offer. Extreme dry season affected development of B. atratus colonies.

[Seasonal transmission of malaria in the Senegal River Valley: case study of the city of Kaedi-Mauritanie]

Introduction

In the face of environmental and climatic changes both ongoing and planned, the epidemiology of malaria in the city of Kaedi (Mauritania), along the Senegal River Valley, requires special attention. Some cases of malaria have been registered in the health facilities throughout the year, with an average of 150,000 annual suspected cases and climatic and ecological conditions which are now favorable for seasonal transmission.

Methods

We conducted two cross-sectional descriptive surveys in the city of Kaedi in September 2014 (wet season) and in May 2015 (dry season). Our cluster sampling involved 700 households. Microscopic examination was performed in all household members. Furthermore, larval surveys, early morning wildlife spraying and nocturnal traps breaking were performed.

Results

During both seasons, 9.313 thick smears were manufactured, 15 were positive, with a plasmodium prevalence rate of 0.16%. Among these, 12 were positive in the dry season and 3 in the rainy season. Plasmodium prevalence rate was 0.26% and 0.06% respectively in the dry season (n = 4642) and in the wet season (n = 4671). In the rainy season, rates were 0.04% (2/4671) and 0.02% (1/4671) respectively for Plasmodium malariae and Plasmodium falciparum. The only species found in the dry season was Plasmodium falciparum. Entomological investigations showed the presence of a single species of Anopheles mosquito, Anopheles gambia (two in the rainy season and six in the dry season). Larval surveys showed that the larval fauna was dominated by Culex larvae (99.6%). Anopheles larvae (0.4%) were collected only during the dry season.

Conclusion

Despite low malaria transmission in the city of Kaedi, in a context of lack of rainfall, health authorities should implement a strategy for malaria elimination in the wilayas of the Senegal River.

Sheep Methane Emission on Semiarid Native Pasture-Potential Impacts of Either Zinc Sulfate or Propylene Glycol as Mitigation Strategies

The aim of this study was to evaluate the effects of Zinc sulfate and propylene glycol (PG) on methane (CH₄) emission, nutrient intake, digestibility, and production in sheep grazing on a native Caatinga (Brazilian semi-arid savannah) pasture during the rainy season (from March to June 2014). Fifteen mixed Santa Inês sheep, all non-castrated males, with initial body weight of 19.8 ± 1.64 kg, and 4 ± 0.35 months of age, were distributed in a complete randomized design into three treatments: control (CT)-concentrate supplemented at 0.7% of body weight; CT + 300 mg of Zn/day; and CT + 2.5 mL of propylene glycol/kg LW^0.75/day. Measurements were done in four periods during the rainy season, with 28 days of interval between each measurement. CH₄ emission was measured using the SF₆ tracer gas technique. CH₄ emission per day was greater in PG than in CT and Zn (p < 0.05). However, no additive effect was observed on the intakes of organic matter (OM) and neutral detergent fiber (NDF), or on CH₄ emission expressed as a function of OM and NDF intakes (p > 0.05). Across the months of the trial, OM and NDF intakes were greater in March, while the greatest emission of CH₄ (g/day and g by g/OM intake) was observed in May (p < 0.05). Total CH₄ emission (kg) from March to June (112 days of evaluation) was greater in PG compared with CT and Zn (p < 0.05). Zinc and PG had no effect on total CH₄ emission when it was expressed per unit of body weight gain or carcass production (p > 0.05). The results of this study indicate that Zinc sulfate and propylene glycol have no beneficial effects in mitigating sheep CH₄ emission. The CH₄ emissions originated from sheep grazing native Caatinga pasture change throughout the rainy season due to fluctuations in availability and quality of pasture biomass. Moreover, the inclusion of zinc sulfate or propylene glycol did not improve animal feed intake, nutrient digestibility, and animal performance.

Discovery of a specialist Copelatinae fauna on Madagascar: highly ephemeral tropical forest floor depressions as an overlooked habitat for diving beetles (Coleoptera, Dytiscidae)

Diving beetles are generally aquatic and live submerged in water during larval and adult stages. A few groups have colonised hygropetric habitats and fewer species still can possibly be referred to as terrestrial. Here we describe six new Copelatine species that were mainly found in dry shallow forest floor depressions in the eastern and northeastern lowland humid forests of Madagascar. Three new species are described in each of the two genera Copelatus and Madaglymbus: Copelatusamphibiussp. nov., Copelatusbetamponasp. nov., Copelatuszanatanensissp. nov., Madaglymbuskelimasosp. nov., Madaglymbusmenalambasp. nov., and Madaglymbussemifactussp. nov. Diagnosis, description, known distribution, ecology, and conservation notes are provided for each species. All species are illustrated with a dorsal habitus image, ventral and lateral views of the male penis, and parameres. Photographs of the unusual terrestrial habitats where the species were found are provided. Madaglymbusmenalambasp. nov. is also documented with macrophotos and videorecordings of the terrestrial locomotion and behaviour in the field. Although these species should not be classified as terrestrial, or even semi-terrestrial Dytiscidae, they seem to be specialists of very ephemeral aquatic habitats and stay put instead of disperse when the habitat dries up. It is hypothesised that this lifestyle and behaviour on Madagascar is restricted to the high-precipitation humid forest regions mainly in the east. It may also represent a transition step, or stepping-stone, towards becoming fully terrestrial, a step that the few known terrestrial Dytiscid taxa once passed through. It is very likely that this type of habitat is overlooked for aquatic beetles, not only in Madagascar, and the six species herein described may be just the “tip of the iceberg”.

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.

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.

Seasonal Differences in Animal Welfare Assessment of Family Farming Dual-Purpose Cattle Raised under Tropical Conditions

Simple Summary

Family-run cattle farms in the tropics deal with two distinct seasons, the dry and the rainy, where features such as resources, diseases and climate are variable. Nevertheless, an acceptable level of animal welfare must be maintained throughout the year. The purpose of this study was to investigate whether there were animal welfare issues at farms affected by either the dry or the rainy season. Forty-five dual-purpose family farms in the Mexican tropics were assessed via the Welfare Quality^® protocol. The animal welfare assessment on these farms obtained better results during the dry season, hence the season presenting a greater risk to animal welfare of dual-purpose cattle raised under tropical conditions is the rainy season. However, there were management-related differences observed between the two seasons, and the dry season also had some animal welfare threats. The fact that farms scored higher during the dry season is possibly the result of farmer awareness, leading to modification of their systems to provide animals with the necessary inputs to meet their production needs. If these modifications, such as providing supplementary feed and water points were not fulfilled, then welfare conditions might have been jeopardized.

Abstract

Conditions on farms in the tropics can differ greatly depending on the season of the year. Characteristics such as disease prevalence, climate and availability of resources may not be constant all year around; however an acceptable level of animal welfare must be maintained throughout the year. Since it is neither practical nor economically feasible to perform several assessments per year, the purpose of this study was to define whether there were animal welfare issues at farms that were affected by the season to identify which season would present a greater risk to animal welfare, using a risk-based approach. Forty-five dual-purpose family farms in the Mexican tropics were assessed via the Welfare Quality^® protocol. During the rainy season, 2.2% of the farms were classified as excellent, 57.8% as enhanced, 31.1% as acceptable and 8.9% as unclassified. In the dry season, 31.1% were classified as excellent, 68.9% as enhanced and none of the farms were categorized as acceptable or unclassified. Consequently, the season which presented the greatest risk to animal welfare of dual-purpose cattle raised under tropical conditions was the rainy season. However, there were management-related differences observed between the two seasons and the dry season also had some animal welfare threats. The fact that farms scored higher during the dry season is possibly the result of farmer awareness, leading to modification of their systems to provide animals with the necessary inputs to meet their production needs. If these modifications were not fulfilled, then welfare conditions might have been jeopardized.

[Characteristics and Source Apportionment of Volatile Organic Compounds in the Rainy Season of Guangzhou City]

Atmospheric volatile organic compounds (VOCs) were measured in an urban area of Guangzhou on July 2016 using an on-line gas chromatography mass spectrometry/fire ion detector. Seventy-three VOCs were detected with an average concentration of (118.83±79.40) μg·m^-3, a maximum concentration of 492.42 μg·m^-3, and a minimum concentration of 10.54 μg·m^-3 during the period. The peak value of the TVOC concentration appeared at about 07:00 in the morning, indicating that motor vehicle pollution had a significant contribution at the site. The minimum value appeared at about 14:00 in the afternoon, related to photochemical losses. High concentrations were also observed from 21:00 to 24:00, which was probably related to pollution emissions and boundary layer compression. Source analysis by PMF showed that the site was mainly affected by five VOC sources: vehicle exhaust, solvent use, fuel loss at fuel stations, plant emissions, and cooking exhaust, the contributions of which were 29.79%, 26.61%, 24.86%, 9.91%, and 8.84%, respectively. Vehicle exhaust was the largest source of VOCs during the daytime, while the contribution of plant emissions increased significantly at noon. The contribution of solvent uses and fuel loss at fuel stations rose during the night and became the main source of VOCs until early morning.

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

Infection is widespread but most prevalent among young, rural residents with fever.

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.