Early Rainy Season Research Articles

Aboveground Net Primary Production at Acacia mangium Plantation in Northern Vietnam

Net primary production (NPP) is an important index for understanding carbon cycling in forest ecosystems. In this study, aboveground NPP at Acacia mangium plantation was estimated basing on allometry for aboveground biomass increment (ΔM) and litter trap technique for litterfall (Lf). The experiment was conducted in two plots of 300 m2 each (15 × 20 m), established at a 21-month old plantation. Data were collected five times of 3-month intervals in a total duration of 357 days. The results indicated that Lf and ΔM were seasonal-dependent. Litterfall was highest (4.06 g m-1 day-1) during Sep-Jan (late rainy season, early winter) and lowest (1.10 g m-1 day-1) during Mar-Jun (early rainy season, early summer). While, ΔM was highest (13.51 g m-1 day-1) during Jun-Sep (rainy season, summer) and lowest (3.10 g m-1 day-1) during Jan-Mar (dry season, winter). Total Lf in a duration of 357 days was 9.69 tons ha-1 and ΔM was 27.71 tons ha-1, leading to total aboveground NPP of the present study plantation of 37.40 tons ha-1. It is concluded that aboveground NPP of acacia plantation was much higher than other forests of different types and ages around the world. Such difference indicates the importance of acacia plantation in soil nutrient cycling through litterfall decomposition and carbon sequestration through aboveground biomass increment.

Studies on parasitic contamination of soil and local drinking water sources, Doma Local Government Area, Nasarawa State, Nigeria

Water is essential to all living things on earth, however if contaminated, can be injurious to human health when consumed. This study evaluates the parasitic contamination of potable water sources and surrounding soil in Doma Local Government Area of Nasarawa State. Forty-eight soil and water samples from different sources (wells, streams and boreholes) were collected from March to July 2017. Water samples were analyzed using the Calcium carbonate (CaCO 3 ) floatation method while a modified Baermann Technique was used to microscopically examine soil samples for the parasitic presences. 32 water samples were parasitized including 2 protozoans ( Entamoeba histolytica , and Giardia lamblia) 3 nematodes ( Trichuris trichiura , Ascaris lumbricoides and hookworm), and Fasciola hepatica a trematode. The nematodes were most contaminated 19(59.38%) while trematodes were least 1(3.13%). The most contamination was in stream water sources for late dry and early wet season (69.23% and 94.74%) while the boreholes had no contamination for both seasons. Prevalence of parasites in relation to water sources showed a high significant difference ( p = 0.0000001), while there was no significant difference in relation to late dry and early rainy seasons ( p = 0.1258). Geohelminths was highest around the boreholes 15(35.71%) but least in the streams 13(30.95%). However, there was no significant difference ( p = 0.6221) in the prevalence rate of geohelminths in relation to sources of water. Result indicated a high rate of parasitic contamination of soil and drinking water sources in the study=area. Hence there is need for advocacy and enlightenment on the importance of proper drinking water treatment. Keywords: Geohelminths; parasitic contamination; water

Studies on the prevalence of fascioliasis among ruminant animals in northern Bauchi state, north-eastern Nigeria

A study of prevalence of ruminant fascioliasis was undertaken from May 2017 to April 2018. A set of 7640 stool and 7640 bile samples were collected from slaughtered cattles, sheeps and goats in seven local abattoirs located within the seven Local Government Areas making up northern Bauchi state. The Sample collection was demarcated into four sections of three months each corresponding into four local seasons. 1910 samples were collected from the beginning to the end of each of the four local seasons. Direct postmortem investigation to detect adult Fasciola spp. was employed. Stool samples were analyzed using formol-etha concentration technique. ANOVA (Analysis of variance) was conducted to examine the prevalence of fascioliasis in six communities of northern Bauchi state. The prevalence of infection was statistically different on different localities. The highest infection rates from the seven sampling sites was Jama'are (48.5%) followed by Zaki (46.9%) p = 0.05. Specie specific prevalence of fascioliasis between the host species was statistically different. Cattles were more infected than sheep and goat. Prevalence of fascioliasis on gender was statistically different, with bulls showing a higher prevalence rate and female sheep and goat recorded higher prevalence. Prevalence of fascioliasis based on estimated ages of animals sampled was statistically significant, animals above 5 years had higher prevalence of 64.5% followed by animals below the age of 1 with 41.3% (p = 0.05). Prevalence of fascioliasis among sampled ruminants based on seasonal variations was statistically significant. Higher prevalence percentages were observed during the early and late rainy season (47.2% and 58.4%) compared to early and late dry seasons (36.2% and 20.1%) p = 0.05. The study, therefore, recommends regular meat inspection alongside public awareness campaigns.

The feasibility of high yielding aus-aman-rabi cropping systems in the polders of the low salinity coastal zone of Bangladesh

Cropping intensity and agricultural productivity in the polders of the coastal zone of Bangladesh are much lower than that of most of the country. The main reasons for this are waterlogging, the late harvest (December/January) of the rainy season rice crop (known as ‘aman’), and the lack of readily accessible fresh water during the dry season in the polders. Waterlogging prevents the production of high yielding and earlier maturing rainy season rice varieties (HYV aman), and of high yielding/value rabi (dry season) crops such as maize and sunflower. However, gravity drainage of excess water from the polders is physically feasible. Furthermore, the rivers surrounding the polders in the central coastal zone (Barisal Division) contain large volumes of fresh river water throughout the year. Research was therefore undertaken to evaluate, under good water management, the feasibility of intensifying to high yielding rice-rice-rabi cropping systems in the low salinity central coastal zone. A replicated cropping system experiment was conducted for two years at Patuakhali using a short duration modern ‘aus’ variety (aus is the name of the rice crop grown during the early rainy season) (BRRI dhan65), a medium duration modern aman variety (BRRI dhan44), and high yielding/value rabi crops. The cropping systems included four aus sowing dates (20 March, 5 and 20 April, 5 May) which resulted in four aman and four rabi sowing dates. Two rabi crops were compared within each sowing date (maize – Pacific 984, sunflower – Hysun 33). Annual cropping system rice equivalent yield (REY) ranged from 13.7 to 20.0 t/ha. All systems were profitable with 100% of labour purchased, although benefit cost ratios (BCR) were not always >3, suggesting low attractiveness to farmers. However, most polder farms are small, with 30–60% of labour provided by the family. With 75% or less of labour purchased (the rest provided by family), all cropping systems were financially attractive, even with a 10% decline in grain price. Rabi crop yield was the main determinant of total system REY and profitability, both of which declined as sowing date of the rabi crops was delayed beyond 15 December. Optimisation of sowing date of the rabi crops should therefore be the first consideration in cropping system intensification for the low salinity coastal zone. The optimum sowing date of both the maize and sunflower was mid-December. For adequate "turn around" time between all crops, for the varieties used in this study, the aus crop should be sown in mid-April and the aman crop in mid-August. This research shows that, with good water management, it is possible to implement highly productive and profitable aus-aman-rabi cropping systems in the low salinity coastal zone of Bangladesh.

Characteristics of the Marine Boundary Layer Jet over the South China Sea during the Early Summer Rainy Season of Taiwan

Abstract The marine boundary layer jets (MBLJs) over the northern South China Sea during the early summer rainy season over Taiwan are analyzed using 5-yr (2008–12) National Centers for Environmental Prediction Climate Forecast System Reanalysis data with a 6-h interval. The MBLJ is distinctly different from the low-level jets associated with the subsynoptic frontal systems. During this period, the MBLJ events over the northern South China Sea mainly occur during the second half of the monsoon rainy season over Taiwan (after 1 June) and have a wind speed maximum around the 925-hPa level. The MBLJs are mainly related to the subsynoptic-scale pressure gradients related to a relatively deep mei-yu trough over southeastern China and a stronger-than-normal west Pacific subtropical high. Within the MBL, there is a three-way balance among pressure gradients, Coriolis force, and surface friction, with cross-isobar ageostrophic winds pointing toward the mei-yu trough throughout the diurnal cycle. At the jet core, the vertical wind profile resembles an Ekman spiral with supergeostrophic winds >12 m s−1 near the top of the MBL. The MBLJs are strongest at night and close to geostrophic flow in the late afternoon/early evening. This is because the friction velocity and ageostrophic wind decrease during daytime in response to mixing in the lowest levels. The MBLJs play an important role in horizontal moisture transport from the northern South China Sea to the Taiwan area. In the frontal zone, the moisture tongue extends vertically upward. The rainfall production is related to vertical motions in the frontal zone or localized lifting due to orographic effects.

Documentation of Major Poisonous Plant on Livestock in Ethiopia

The review was conducted with the objective of documenting potentially poisonous plants in Ethiopia. One of the major causes of economic loss in the livestock industry is Poisonous plants especially in the developing country including Ethiopia. In each year poisonous plant affect 3 to 5 percent of the cattle, sheep, goat, and horses that graze ranges. Major loss caused by these plants result from death of livestock, abortions, photosensitization, decreased production, emaciation, and birth defects and also they have other losses due to increased management costs associated with such things as fencing to prevent access of animals to these plants , altered grazing programs, and loss of forage due to removal of these plants. Livestock mostly exposed to toxic plants in dry and early rainy season when feed is in short supply. In this documentation 71 different plants identified from four different area of the country were collected from different governmental and non-governmental organizations and published papers. A more extensive survey is required to document all poisonous plants in the rangelands and to identify the major toxic principles in the different species possibly pharmacological activity. This documentation review the current knowledge on the identity of plants known to have poisoned livestock and research conducted into these toxic plants.

Use of estuarine resources by top predator fishes. How do ecological patterns affect rates of contamination by microplastics?

This study assessed the seasonal patterns of habitat utilization, feeding ecology and microplastic contamination in different ontogenetic phases of sympatric snooks (Centropomus undecimalis and C. mexicanus) inhabiting a tropical estuary. More than 50% of snooks, in all ontogenetic phases, ingested microplastics (1.5 ± 0.1 and 1.4 ± 0.1 particles ind−1). Juveniles migrated to nursery grounds in the upper estuary, during the early dry (C. undecimalis 6.5 ± 2.8 ind−1) (p < 0.01) and early rainy seasons (C. mexicanus 4.1 ± 1.9 ind−1). There, they fed mostly on invertebrates (Polychaeta) (p < 0.01), and became contaminated by microplastics (C. undecimalis: 0.8 ± 0.4 particles ind−1; C. mexicanus: 1.7 ± 0.5 particles ind−1). Sub-adults of both species forage principally in the estuarine habitats after shifting their diet from invertebrates (shrimps) in the upper reaches (1806.4 ± 1729.6 mg ind−1) to pelagic fishes (R. bahiensis) in seaward habitats (2507.7 ± 1758.4 mg ind−1). During feeding continues the contamination by microplastics (3.1 ± 0.8 part. ind−1). Adults use the adjacent coastal as feeding and spawning grounds during the rainy season. In this phase, snooks are mostly piscivorous (R. bahiensis: up to 5303.8 ± 3213.4 mg ind−1), but also ingest penaeid shrimp as complementary item (up to 175.9 ± 156.7). Microplastics contamination rates increased towards the adult phase, with maximum contamination coinciding with peaks of fish ingestion, suggesting trophic transfer of microplastics. The lower estuary and adjacent coastal zone were important contamination sites, especially during the rainy season (up to 3.1 ± 0.8 part. ind−1) (p < 0.01), when fishery activities is intense and river basin runoff increases. Consequently, the availability of microplastics is higher during this time of year in the lower portion of the estuary. Snooks had similar prey preferences, but the use of different habitats along the life cycle of each species avoids overlaps in estuarine use and minimizes competition.

Impact of teleconnection between Indian Ocean Dipole (IOD) and El Niño at normal (neutral) phase condition on the Java Monsoon rainfall variability

The meteorological surface parameter over the Maritime Continent (MC), especially rainfall anomalies are very important to be investigated due to their impacts on the hydrometeorological hazards phenomena. Although, this region is effected by the Monsoon system, but another phenomena called as the Indian Ocean Dipole (IOD) and El Niño are suspected has a great effects in controlling the rainfall anomalies too. In this present study, we investigated the upcoming of IOD and El-Niño (represented as SST Nino 3.4) index, especially from October 2018 to February 2019. According to the prediction derived from POAMA (Predictive Ocean Atmosphere Model for Australia) model, Australia, that is issued by September 8, 2018, we found that those indexes (IOD and SST Nino 3.4) are located “near” the normal (neutral) phase condition. It means that Monsoon will become a pre-dominant peak oscillation during that period, although by assuming the Madden Julian Oscillation (MJO) also located at “near” normal condition. By using the IOD, SST Nino 3.4, and the CHIRPS (Climate Hazards Group InfraRed Precipitation with Station) monthly rainfall data for period of 37 years observation over Java Island, we found that rainy season is already started since December 2017. The transitional season (from rainy to dry season) is started from March to May 2018. The dry season itself is already started since June to August 2018. Basically, we found the second transitional season that is started from September to November 2018. Since, this study is mainly concerned to rainfall anomalies prediction when IOD and El-Nino is located “near” normal (neutral) phase position, we suspect that the early rainy season this year will be started at December 2018, and continue to rainy season at January and February 2019. Those all prediction will be working well by assuming that teleconnection between IOD and El Nino up to February 2019 still located “near” normal phase condition/position.

Effect of season on reproduction in west African Dwarf Bucks

This study was conducted to determine effects of season on some reproductive parameters of WAD bucks. Nine apparently healthy WAD bucks, aged between 18 and 24 months and weighing 8-15 Kg, were used to evaluate the effect of seasonal variations on Live-Weight (LW), Rectal Temperature (RT) and Scrotal Circumference (SC) between January and December, 2013. Semen was collected monthly by electro-ejaculation method and evaluated for spermiogram using standard techniques. Results were compared between and within groups using analysis of variance for repeated measures. Values are significant at p ˂ 0.05. Seasonal variation significantly (p ˂ 0.05) affected RT and SC except total sperm morphological abnormalities. Means for the total sperm morphological abnormalities were 7.42 ± 3.21% (late dry), 3.42 ± 0.36% (early rainy), 6.33 ± 0.33% (late rainy) and 7.25 ± 1.18% (early dry). The total morphologically abnormal spermatozoa reported for the seasonal study was 6.10%. It was thus concluded that seasons does not have significant effect on the spermiogram of WAD buck, however, they appeared to be most fertile during the early and late rainy seasons and least potentially fertile during early and late dry seasons.Keywords: Spermiogram, Season, Buck, Rectal temperature, Reproduction

Spatial distribution and population data of cave millipedes, genus Pseudonannolene Silvestri, 1895 (Diplopoda, Spirostreptida) from Brazil

Millipedes are widely found inside caves, where they are favoured by the darkness and the high humidity. Despite this, no population studies focusing their distribution along environmental gradients have been done so far. This study aimed to estimate the population density and spatial distribution of one troglophilic species of Pseudonannolene from a cave located in southeast Brazil. The data were obtained through the visual census method through bases distributed in different zones and substrates along the cave. The population density varied from 0.07 ind.m-² (9 individuals) at the beginning of the dry season to 0.402 (37 individuals) at the beginning of the rainy season. In relation to zonation and substrate, the largest number of individuals was found in the twilight zone and in the soil and rocky substrates. The number of individuals captured was higher in samplings conducted early and middle rainy season, despite the effect of seasonality was marginally significant. The abundance was low in both environments (hypogean and epigean), corroborating that the low population density is an intrinsic characteristic of the group as a whole. The low population density of Pseudonannolene may be due to: 1) the low calcium content inthe soil and, consequently, in the cave; 2) the effect of guano scarcity in the cave, sincethis is the main trophic resource for these millipedes in the subterranean environment; and 3) the effect of seasonality, as it may be a consequence of the stress caused by theatypical drought of the last two years, so this population would be in recovery.

Time series modeling of pneumonia admissions and its association with air pollution and climate variables in Chiang Mai Province, Thailand

This study aimed to predict the number of pneumonia cases in Chiang Mai Province. An autoregressive integrated moving average (ARIMA) was used in data fitting and to predict future pneumonia cases monthly. Total pneumonia cases of 67,583 were recorded in Chiang Mai during 2003–2014 that the monthly pattern of case was similar every year. Monthly pneumonia cases were increased during February and September, which are the periods of winter and rainy season in Thailand and decreased during April to July (the period of summer season to early rainy season). Using available data on 12 years of pneumonia cases, air pollution, and climate in Chiang Mai, the optimum ARIMA model was investigated based on several conditions. Seasonal change was included in the models due to statistically strong season conditions. Twelve ARIMA model (ARMODEL1–ARMODEL12) scenarios were investigated. Results showed that the most appropriate model was ARIMA (1,0,2)(2,0,0)[12] with PM10 (ARMODEL5) exhibiting the lowest AIC of − 38.29. The predicted number of monthly pneumonia cases by using ARMODEL5 during January to March 2013 was 727, 707, and 658 cases, while the real number was 804, 868, and 783 cases, respectively. This finding indicated that PM10 held the most important role to predict monthly pneumonia cases in Chiang Mai, and the model was able to predict future pneumonia cases in Chiang Mai accurately.

Abundance and diversity of black flies (Diptera: Simuliidae) in rivers of the Andean Eastern Hills of Bogotá (Colombia),

Black flies are abundant benthic organisms in well-oxygenated running water and are considered effective bioindicators of water quality. Information on the ecology of these organisms at the species level is important, since up to now information has mainly been available on a family level. The aim of this study was to evaluate the composition of black flies and their relationships to a group of physical and chemical factors in four small rivers of the Eastern Hills around Bogotá, Colombia. These headwaters are protected by the Empresa de Acueducto y Alcantarillado de Bogotá. Black fly larvae and pupae were collected during four sampling periods during the dry season to the early rainy season of 2012. Multivariate methods were used to determine the presence of each species in relation to dissolved oxygen, nitrates, pH, temperature, and water velocity. PCA ordination revealed a physicochemical environment with a tendency towards a certain homogeneity in the fourrivers studied. The DCA ordination confirmed that in La Vieja River the G. ortizi complex dominated while S. muiscorum was dominant in the other three rivers. Similarly, according to the NMDS, the composition of black flies in Arzobispo and Chorro de Padilla rivers was similar, while that of El Delirio and La Vieja rivers were different, especially in this last river. The rivers hadlow species richness (four species and one species complex). Simulium muiscorum was negatively correlated with dissolved oxygen, temperature and current velocity while S. ignescens was associated with slightly more oxygenated waters and S. furcilatum with fastercurrents.The low species diversity and richness for the four rivers is consistent with previous report sof low Neotropical diversity of black flies. Results showed that simuliid species could possibly be good indicators of the environmental conditions of Eastern Hills rivers around Bogotá.

Microclimate in understories of a mango orchard and a degraded area in the Eastern Amazon

Changes in land use alter regional microclimate. This study compared the microclimate in understories of a mango orchard and a degraded area in the municipality of Salinópolis, in the northeast of the Brazilian State Pará, eastern Amazon. In both environments, the microclimate was monitored through collecting data on the following variables: maximum, minimum and average air temperature, air thermal amplitude and vapor pressure deficit. The microclimate was monitored daily during four seasons: early rainy season, late rainy season, early dry season and late dry season, between December 2015 and November 2016. Vegetation coverage was the most important factor to soften maximum and average air temperature in the understories. Lower values of meteorological variables were observed in the mango orchard understory, especially during late rainy season and late dry season, except for minimum air temperature, which was lower in the understory of the degraded area, especially during the late rainy season. The microclimate in the understory differed between both environments, and mango orchards may ameliorate the understory microclimate more efficiently than degraded areas; therefore, the mango orchard can be used as an alternative for the rehabilitation of degraded areas.

Milpa: One Sister Got Climate-sick. The Impact of Climate Change on Traditional Maya Farming Systems

The milpa is a traditional Mesoamerican polycropping system involving rain-fed cropping of maize (Zea mays), squash (Cucurbita moschata) and legumes (Phaseolus vulgaris, Phaseolus lunatus, Vigna unguiculata), crops which in this part of the world are known as the three sisters. Despite alterations due to socio-economic changes during the twentieth century, milpafarming still characterizes subsistence production systems of peasants of Maya ethnicity in the central Yucatan Peninsula, Mexico. In Dziuche, a community in the state of Quintana Roo, more ‘classical’ interpretations of the milpa, commonly cultivated by the older generation of peasants, are competing with systems that are essentially hybrids of the milpa and conventional maize farming; however, management and output of both variants are affected recently by changing precipitation patterns associated with global climate change. In the present study, implemented in Dziuche in 2012–2014, we recorded and analysed recent changes in milpa production systems. Particularly, we compared the milpas of two peasants from different generations – one is 30 years old and the other 56 years old. Through a triangulation of participatory and qualitative methodologies, including dialogue between interlocutors, focus groups, and participatory elaboration of an agricultural calendar, we recorded their perceptions of the impacts of climate change on crop management, yield and agrobiodiversity. This information was enriched with economic data related to these production systems. The data was then validated with the entire peasant assembly of Dziuche. It was observed that, regardless of their age, traditional farmers responded to the late arrival or non-arrival of the early summer rainy season by shifting their maize planting dates and by reducing agrobiodiversity, mainly by eliminating beans. The results contribute to the current discussion around the impacts of climate change on traditional production systems. It was shown that despite resilience mechanisms inherent to peasant farming, the magnitude of climate change is challenging farmers to an extent that they respond with objectively counterproductive measures, such as decreasing agrobiodiversity. It must be added that in the case of Maya peasants, these reactions are not only caused by altering climatic conditions but also by socio-economic developments like the loss of empirical knowledge transfer, a decreasing number of family members available for unpaid agricultural work, and changes in land tenure.

Nightly Biting Cycles of Anopheles Species in Rural Northwestern Burkina Faso.

The biting behavior of anophelines is an important determinant of malaria transmission. Understanding the local vector host-seeking behavior, its outdoor/ indoor biting preference, and nocturnal biting periods is essential for effectively applying and improving vector control methods, such as Long Lasting Insecticidal Nets (LLINs) and personal protective measures. To better understand the biting and host-seeking patterns of Anopheles mosquitoes in Northwestern Burkina Faso, we performed biweekly Human Landing Catches (HLC) in six villages during the period of highest mosquito abundance and malaria transmission. We applied a negative binomial regression framework to statistically analyze the host-seeking activities of Anopheles species and test for differences across hours, months, and villages, as well as for differences between indoor and outdoor capture points. Anopheles gambiae s.l. was identified as the main malaria vector in this region, representing about 90% of the total anopheline population. Biting activity was significantly different across hours and showed a peaked plateau between 2000 and 0200 hours. Differences in the pattern of biting cycles were observed between the early and late rainy season. This study shows that anopheline biting activity in Northwest Burkina Faso is high throughout the night, at indoor and outdoor posts alike. Consequently, bed nets alone may not provide sufficient protection against early biting anophelines and should be complemented with additional strategies such as indoor residual spraying (IRS) and larval source management (LSM) to meet the WHO’s ambitious goals that are reflected in the global technical malaria strategy for 2030.

Spatial and Temporal Flood Characterization of Pindul Karst System, Gunungkidul Regency

Pindul karst system has cave system and sinking stream recharge that cause it prone against flash flood. This research will study flood characteristics in the karst system. Water level logger was installed on karst system outlet and sinking stream of Kedungbuntung to obtain discharge data at 15 minutes interval. Rainfall data is obtained by installing automatic rain gauge on middle parts of karst system. Recording of both was done for six months (January – June). Flood characteristics was obtained by flood hydrograph and rainfall characteristics. The results indicated that Pindul karst system have faster time lag (Tlag) (1.1 and 1.7 hours) than rainfall duration (1.9 hours). Excess rainfall (Pe) is rainfall characteristic that is most influencing flood incident. Temporarily, rainfall percentage becoming surface runoff (% Pe) in outlet and Kedungbuntung were greater at end of rainy season (37% and 14%) than in early rainy season (16% and 8%). Pe percentage below 50% indicated that Pindul karst system is still good in storing groundwater. In spatial term, faster flood behavior in outlet was caused by recharge from cave system and sinking stream. Meanwhile, Kedungbuntung was recharged by aquifer with domination of diffuse fracture.

The impact of leaf-eating caterpillars (Heortia vitessoides) infestation on agar trees in Carita forest research station, Province of Banten

The gregarious caterpillars of Heortia vitessoides Moore is a major defoliator of agar trees. The pest seriously threatens the existing agar tree plantation that has been widely cultivated in the community. Pest attacks began to occur in Indonesia since 2005, resulting in the damage and death of agar tree plants in various regions.To determine the impact of pest attack, a study was conducted through periodic monitoring at agar plantation in Carita Forest Research Station (CFRS), Banten Province, from April 2012 to March 2015. Monitoring was conducted in three plots of agar plantations. Each plot consists of six permanent subplots and in each subplot 15 samples of agar tree were randomly choosen. Data were collected and analyzed on monthly basis according to the intensity of defoliation and the mortality of agar trees. Defoliation intensity was determined by the percentage number of trees suffering defoliation in four damage categories, i.e.: light (10-25%), moderate (25-50%), heavy (50-75%), and severe (75-100%). Tree mortality was calculated as the annual percentage of dead trees. The study showed that the defoliation occurred throughout the year in varying degrees of damage. The monthly percentage of defoliated trees is about 30-70% annualy. The high percentage of tree defoliation mainly occurs during dry and early rainy season (June-December). Higher percentage of heavy and severe defoliations were found mostly at seedling. Repeated heavy defoliation causes stunted growth and tree mortality. Early monitoring and control of pests are very important to be done regularly to prevent the damage wider and heavier.

Seasonal variation in the abundance and distribution of Anomalocardia flexuosa (Mollusca, Bivalvia, Veneridae) in an estuarine intertidal plain.

Spatial and temporal density and biomass of the infaunal mollusk Anomalocardia flexuosa (Linnaeus, 1767) evaluated a tidal plain at Goiana estuary (Northeast Brazil). Three hundred and sixty core samples were taken during an annual cycle from three intertidal habitats (A, B and C). Shell ranged from 2.20 to 28.48 mm (15.08 ± 4.08 mm). Recruitment occurred more intensely from January to March. Total (0–1,129 g m−2) differed seasons (rainy and dry), with highest values in the early rainy season (221.0 ± 231.44 g m−2); and lowest values in the late dry season (57.34 ± 97 g m−2). The lowest occurred during the late rainy (319 ± 259 ind m−2) and early dry (496 ± 607 ind m−2) seasons. Extreme environmental situations (e.g., river flow, salinity and water temperature) at the end of each season also affected density ranges (late dry: 0–5,798 ind m−2; late rainy: 0–1,170 ind m−2). A. flexuosa in the Goiana estuary presented a dominance of juvenile individuals (shell length < 20 mm), with high biomass main the recruitment period. Average shell length, density and biomass values suggest overfishing of the stock unit. A. flexuosa is an important food and income resource along its whole distribution range. The species was previously also known as Anomalocardia brasiliana (Gmelin, 1791).

Relative proportions of E. coli and Enterococcus spp. may be a good indicator of potential health risks associated with the use of roof harvested rainwater stored in tanks

A total of 285 water samples were collected from 71 roof harvested rainwater tanks from four villages in different provinces over a two-year (2013-2014) period during the early (October to December) and late (January to March) rainy season. Water quality was evaluated based on Escherichia coli, faecal coliforms and Enterococcus spp. prevalence using the IDEXX Quanti-Tray quantification system. Real-Time PCR was used to analyse a subset of 168 samples for the presence of Shigella spp., Salmonella spp. and E. coli virulence genes (stx1, stx2 and eaeA). Escherichia coli were detected in 44.1% of the samples, Enterococcus spp. in 57.9% and faecal coliforms in 95.7%. The most prevalent E. coli concentrations in harvested rainwater were observed in 29.1% of samples and 22.5% for Enterococcus spp. and, were within 1-10cfu/100ml and 10-100cfu/100ml, respectively, whereas those for faecal coliforms (36.6%) were within 100-1000cfu/100ml. On average 16.8% of the samples had neither E. coli nor Enterococcus spp. detected, while 33.9% had only Enterococcus spp. and 23.7% had only E. coli. E. coli and Enterococcus spp. were detected together in 25.5% of the samples. Evaluation of samples for potential pathogenic bacteria showed all tested samples to be negative for the Shigella spp. ipaH gene, while five tested positive for Salmonella ipaB gene. None of the samples tested positive for the stx1 and stx2 genes, and only two tested positive for the eaeA gene. These findings are potentially useful in the development of a simplified risk assessment strategy based on the concentrations of indicator bacteria.

A Cross-sectional Study of Bovine Trypanosomosis in Sayo District, Oromia Regional State, Western Ethiopia

A cross sectional study of bovine trypanosomosis was conducted in Sayo district of Kellem Wollega zone, Western Oromia Region, during early dry (December, 2016) and early rainy (June, 2017) seasons employing parasitological blood examination and survey of vectors. A total of 860 representative blood samples were collected from randomly selected cattle and examined using standard methods of parasitological examination techniques. Accordingly, the overall prevalence of bovine trypanosomosis was found to be 11.16%. The species of trypanosomes encountered include Trypanosoma congolense (52.10%) followed by T. vivax (32.30%), T. brucei (10.40%) and mixed infection of T. congolense and T. vivax (5.20%). The seasonal prevalence of bovine trypanosomosis was 15.11% and 7.20% in early dry and early rainy seasons, respectively. There was a statistically significant difference (P 0.05) in the prevalence of bovine trypanosomosis between different sex categories. The mean PCV value of trypanosome infected animals was (22.94% ± 0.15%) compared to non infected groups (26.47 ± 0.35%) with statistically significant difference (P<0.05). As part of survey of vectors of bovine trypanosomosis a total of 1575 flies were caught during the study period. The findings encountered revealed that 807 (51.24%), 667 (43.35%) and 101(6.41%) were Stomoxys, Glossina and Tabanus respectively. The apparent density of Glossina, Stomoxys and Tabanus were 4.16, 5.04 and 0.63 f/t/d, respectively. The present study disclosed that despite vector control implementation practices in the study area, bovine trypanosomosis still remain to be a core problem. Therefore, the current control strategies being implemented in the study area should be further assessed and consideration of integrated trypanosomosis and vector control approaches should be instituted.