Tropical Asian Countries Research Articles

Mythimna separata herbivory primes Coix resistance in systemic leaves.

Coix lacryma-jobi L. belongs to family Poaceae, is widely cultivated in tropical Asian countries for its nutritional and medicinal values. Coix is often threatened by lepidopteran such as Mythimna separata during its life cycle, resulting in severe yield reduction. Insect feeding can trigger defense signaling and increased defense responses in many other crops, yet little is known about whether simulated armyworm feeding on Coix leaves could induce anti-herbivory responses and whether armyworm feeding could activate priming in systemic leaves. In this study, Mythimna separata simulated herbivory elicited increased jasmonic acid (JA) level, JA-Ile (JA-isoleucine conjugate) and altered transcriptome in the Coix leaves. Meanwhile, M. separata simulated herbivory in local leaves primed the systemic leaves for increased accumulation of jasmonic acid and enhanced resistance to M. separata. Consistently, transcriptome analysis showed the systemic leaves were primed, which were up- or down-regulated comparing with the non-primed systemic leaves. In this study, we first reported Mythimna separata simulated herbivory induced increased defense response in leaves of Coix, also Mythimna separata herbivory primed Coix resistance in systemic leaves. This study provides new insight into the regulation of defense responses of Coix against M. separata and the ecological function of priming in Coix.

The complete chloroplast genome assembly of Amorphophallus tonkinensis Engler and Gehrmann 1911 from southwestern China

Species in the Amorphophallus genus are important cash crops in many tropical and subtropical Asian countries. Although several molecular markers have been employed to determine relationships and assess genetic variation in the Amorphophallus genus, some conflicts remain in infrageneric classification and evolution. To aid in the phylogenetic research of the Amorphophallus genus, we collected one sample of Amorphophallus tonkinensis Engler and Gehrmann 1911 from southwestern China. We assembled the first chloroplast genome of this species using high-throughput sequencing. The assembled genome was 169,341 bp long with a typical quadripartite structure (GenBank accession number: PP234804). The lengths of the large single-copy region, small single-copy region, and two inverted repeats were 90,705 bp, 15,640 bp, 31,498 bp, and 31,498 bp, respectively. We annotated 129 genes across the chloroplast genome of A. tonkinensis. The phylogenetic trees suggested that the Amorphophallus species distributed in continental Asia split into two main clades. The chloroplast genome reported in our study provided valuable genomic resources for the future phylogenetic research of the Amorphophallus genus.

Uptake and Determinants of Tetanus Vaccination among Female Clinical Medical Students in North-Western Nigeria

Background and Aim: Neonatal and maternal tetanus have remained endemic in tropical countries of Asia and Africa, with high fatality. Vaccination of women of childbearing age is the main strategy for their prevention/elimination. However, the uptake of these vaccines among these women has remained dismally low in these parts of the world. This study looked at the uptake and determinants of tetanus vaccination among the female clinical medical students of Bayero University, Kano, purposely looking at the interplay between knowledge and other factors on vaccine uptake. Materials and Methods: This was a cross-sectional study of female medical students aged 15–45 years, selected using probability proportionate to size and simple random sampling. The required information was collected using a validated semi-structured questionnaire. The data were analyzed using the Statistical Product and Service Solutions (SPSS) for Windows version 23. Prevalences of tetanus vaccination were calculated. The presence of a statistically significant difference in prevalence and other characteristics of the study groups were determined using appropriate tests. P <0.05 was considered statistically significant. Results: The participants were 140 with the mean age and mean knowledge scores of 23.96 (±2.74) years and 6.61 (±2.47), respectively. Most of them (59.3%) had good knowledge score (>7). The prevalence of tetanus toxoid (TT)1 and TT2 was 20.7% and 17.1%, respectively. Being married, ever pregnant, and higher level of study were significantly associated with being vaccinated (χ2 / P =59.093/P <0.001, P = 65.011/P <0.001, and P = 9.860/P =0.020, respectively). Conclusions: Despite the good knowledge of the vaccination, the uptake of TT vaccination among clinical female students was poor. Factors significantly associated with higher vaccine uptake were marital status, age of the participants, and their class of study.

Meta-analysis of prevalence and associated risk factors for lameness in dairy cattle across tropical Asian nations

Context Lameness in dairy cattle affects the health, welfare, performance, and profitability of dairy farms. Being multifactorial in nature, several animal and farm-level risk factors influence the severity and prevalence of lameness. Aims The objective of the present meta-analysis study was to provide a pooled estimate of the prevalence and identification of the potential risk factors associated with lameness in dairy cattle across tropical Asian countries. Methods A literature search reporting prevalence data for lameness in dairy cattle of tropical Asian countries including India, Bangladesh, Pakistan, Malaysia, Nepal and Thailand for the past 21 years (2000–2021) was collected by using appropriate keywords from the electronic databases. After removing outlier studies, a meta-analysis of 38 studies published in English was performed under a random-effects model by using the meta package (metaprop function) in R software. Key results The pooled estimate of the overall prevalence of lameness was 15.13% (95% confidence interval [CI] = 13.01, 17.53). High heterogeneity was found in the prevalence estimates among the published studies (P < 0.05). The pooled prevalence for lameness-related lesions was, for overgrown hooves 34.42% (95% CI = 23.41, 47.42), interdigital 28 hyperplasia 9.73% (95% CI = 5.84, 15.78), white line disease 6.91% (95% CI = 3.54, 13.05) and sole ulcer 6.84% (95% CI = 3.87, 11.83). The prevalence of lameness was higher in cows at parity three (23.03%) and at parity greater than or equal to 4 (31.68%) than at first and second parity. Breed of an animal, lower body condition score (BCS), housing and floor type, and season also had a significant effect on the pooled prevalence of lameness (P < 0.0001). Conclusions The findings of the present study showed that lameness is prevalent across the tropical Asian countries and there was a significant association of risk factors such as housing, floor, hygiene, and animal nutrition with lameness in dairy herds. Implications Meta-analysis study indicated that there is a need to adopt better management practices to minimise the incidence of lameness in dairy animals.

Anthropogenic disturbance of aquatic biodiversity and water quality of an urban river in Penang, Malaysia

Malaysia's rapid economic and demographic development have placed negative pressure on its water supplies and the quality of the Juru River, which is close to the nation's capital and its major source of water. Healthy aquatic ecosystems are supported by physicochemical properties and biological diversity. This study evaluated the anthropogenic impacts on aquatic biodiversity, especially plankton, fish, and macrobenthos, as well as the water quality of the Juru River in the Penang area. Aquatic biodiversity and river water parameters were collected from ten sampling stations along the Juru River. Seven variables were used to assess the physicochemical environment: pH, temperature, total suspended solids (TSS), salinity, dissolved oxygen (DO), biochemical oxygen demand (BOD), and chemical oxygen demand. At each sampling station, the total number of plankton, fish, and macrobenthic taxa were counted and analyzed. The relationships between the physicochemical parameters and aquatic biodiversity were investigated with biotypological analysis, principal component analysis, hierarchical cluster analysis, and linear regression analysis. These analyses showed that the richness and diversity indices were generally influenced by salinity, temperature, TSS, BOD, and pH. The data obtained in this study supported the bioindicator concept. The findings, as they related to scientifically informed conservation, could serve as a model for Juru River management, as well as for river management throughout Malaysia and other tropical Asian countries.

The effectiveness of chaff flower against snake bite. (Achyranthes aspera)

Achyranthes aspera is a common plant for snake venom. Ethanol extracts of leaves of the plant Achyranthes aspera were evaluated using an in vitro assay. Snakebites are a major problem in rural areas of tropical countries, and research has shown that the plant Achyranthes aspera. Aspera acts as an anti-venom against snakebites. They are mainly called chaff flowers. Achyranthes aspera belongs to the Amaranthus family, and the species Aspera is found in India, tropical Asian countries, and other parts of the world. It has 1-3 feeds of tough erect perennials with simple oval leaves. Further pharmacological studies have shown that some medicinal activities include anti-parasitic, cardiovascular, renoprotective, anticancer, anti-snake venom, wound healing, cardiovascular, spermicidal, liver It was found to have protective activity, diuretic activity, etc. The flower color of this plant is yellowish, greenish-white. Square stems and branches 0.2-2.0 m high, often purplish, petioles 1.2-3 cm long, sepals 4 mm long, nuts about 2 mm long, oval. It is black and has a hole. Its structure mainly contains achyranthes chemical substances and also triacontanol, saponins, flavonoids, tannins, etc. Grind the dried stems into fine powder with a mortar and pestle.

Calibration and Validation of APSIM Millet Model for Proso millet (<em>Panicum miliaceum</em> L.) Accessions as a Basis for Crop Diversification

Purpose: Proso millet (Panicum miliaceum L.) is an underutilised minor millet grown as a rain-fed crop in subsistence farming systems in tropical African and Asian countries including Sri Lanka. It is identified as a climate-resilient crop that exhibits a huge potential to diversify conventional farming systems, however few modelling studies have assessed this crop, especially in the tropics. The objective of this study is to calibrate and validate Agricultural Production Systems Simulator (APSIM) model for Proso millet. Research Method: The millet model of APSIM that was developed based on Pearl millet was calibrated for five farmer-selected Proso millet accessions using the data gathered from two field experiments. Yield data collected from 35 farmers’ fields under different crop management practices were used to validate the model. Findings: The observed phenology, leaf area index, above ground biomass and grain yield were not significantly different (p > 0.05) from the simulated values of the calibrated model. The observed yields (1187±336 kg ha–1) in the farmers’ fields were not significantly (p > 0.05) different from the simulated yields (1208±255 kg ha–1), suggesting a good calibration of the model. Research Limitations: Lack of field data under different abiotic stress conditions is a limitation for further validation of the model. Originality/ Value: APSIM millet model has not been tested for Proso millet previously. Derived genetic coefficients were successfully used to simulate Proso millet production.

KAJIAN FITOGEOGRAFI TUMBUHAN ANGGREK ENDEMIK DI HUTAN PENELITIAN UNIVERSITAS BORNEO TARAKAN

The purpose of this study is to examine the phytogeography of endemic orchid plants in the University of Borneo Tarakan research forest. In this sort of exploratory research, the sampling point is chosen by the researcher using an adaptive sampling sample. This study was conducted in the University of Borneo Tarakan’s Research Forest, which has an area of around 70 ha. The sample site has a 120,617 m² location area. According to the study’s findings, there are two different species of orchids, including Bromhedia finlaysoniana, which has a terrestrial habitat, and Dendrobium crumenatum, which has an epiphytic habitat. From the results of these values, the average distribution value is 1, which means that the distribution pattern is random. Orchid growth can also be affected by different environmental parameters in each location. Bromhedia finlaysoniana and Dendrobium crumenatum, two types of orchids that were discovered as a result of the research, are endemic to tropical southeast Asian countries and are common in many regions of Indonesia, including Kalimantan, Maluku, java, the Lesser Sunda Islands, Sulawasi, and Sumatra. Keywords: phytogeography study, Bromheadia finlaysoniana, Dendrobium crumenatu, Endemic

On the critically endangered red teruntum mangrove (Lumnitzera littorea)

Mangroves are ecologically important forest communities along tropical and subtropical coasts with 70 woody species belonging to about 30 genera in 20 families. Lumnitzera littorea (Jack) Voigt of the Family Combretaceae is a critically endangered true mangrove species indigenous to Sri Lanka. This species is distributed widely on the east coast of Africa, northern Australia, Polynesia, and tropical Asian countries. It is only known from a few locations in Sri Lanka. Therefore, in Sri Lanka L. littorea has been identified as a critically endangered (CR) species in 2007, 2012, and 2020 National Red Lists.

Phytochemical Profiling of <i>Gynura procumbens</i> (Lour.) Merr. Leaves and Stem Extracts Using UHPLC-Q-Orbitrap HRMS

In Indonesia, Gynura procumbens (Lour.) Merr., known as Longevity Spinach or Sambung Nyawa, is commonly grown in tropical and subtropical Asian countries. Many biological activities of G. procumbens have been reported. As we know, the composition and concentration of metabolites, as well as plant parts will significantly affect the biological activities. In this work, UHPLC-Q-Orbitrap-HRMS was used for the putative identification of metabolites present in 70% ethanol extract of G. procumbens leaves and stem extract. Also, we performed clustering of G. procumbens leaves and stem extracts using principal component analysis (PCA) with the peak area of the identified metabolites as the variable. Thirty-one metabolites were identified, and the number of identified peaks in the leaves is higher than in the stem. Those identified metabolites are phenolics, fatty acids, oxo monocarboxylic acids, porphyrins, and chlorophyll fragments. The PCA results showed that the leaves and stem extracts could be grouped, indicating that the composition and concentration of detected compounds differed.

S2.2c Talaromycosis in HIV-negative patients: challenges and counter-measures

S2.2 Histoplasmosis and talaromycosis, September 21, 2022, 3:00 PM - 4:30 PM Talaromycosis is an infection caused by the thermally dimorphic fungus Talaromyces marneffei (T. marneffei). It is endemic in tropical countries of Asia and Southeast Asia and has recently been recognized far beyond the traditional endemic areas. Talaromycosis was thought to be exclusively associated with HIV infection. However, an increasing number of T. marneffei infections have been reported in non-HIV-infected patients. Although the incidence of talaromycosis in non-HIV-infected patients is ˂ 10%, the atypical presentation of this disease can lead to misdiagnosis, inappropriate treatment, and poor outcomes, in addition to tremendous burden and suffering for patients and their families. Screening for immunodeficiencies in patients with talaromycosis is crucial in clinically suspicious cases. Our cohort studies identified three major immunodeficiencies in non-HIV patients with talaromycosis: (1) 85.9% anti-interferon-γ autoantibodies, (2) primary immunodeficiency disorders, and (3) tumors. In disseminated talaromycosis, most patients present with fever, anemia, weight loss, respiratory symptoms, hepatosplenomegaly, lymphadenopathy, and osteolytic destruction and are often misdiagnosed as tuberculosis and other diseases. Localized talaromycosis, on the other hand, is usually manifested by ulcers or masses in the mouth, throat, and external genitalia. Although antigen screening is an effective approach for diagnosing talaromycosis in patients with advanced HIV disease, pathogen-based detection is still limited by atypical clinical presentation. Direct microscopic examination, mycological culture, and histopathology are the standard traditional diagnostic methods used to isolate T. marneffei from clinical specimens, however, due to time-consuming, it might lead to delay diagnosis. Metagenomic next-generation sequencing (mNGS) technology has shown promising results as a rapid, convenient method for detecting T. marneffei from various types of specimens, leading to correct diagnosis and appropriate treatment. Based on our current retrospective study, mNGS has been shown to be equivalent and possibly superior to conventional fungal culture in terms of speed and specificity in the diagnosis of talaromycosis. In terms of final clinical diagnosis, mNGS showed a high sensitivity of 97.22% compared with conventional culture (61.11%). Correction of underlying immunodeficiencies and early use of antifungal agents are important treatment strategies for talaromycosis. Currently, there is no optimal therapeutic regimen for the treatment of talaromycosis in this specific group of patients. Amphotericin B is the first line to initial antifungal treatment, other antifungal agents such as voriconazole have shown good efficacy against talaromycosis. We investigated the efficacy of voriconazole in the treatment of talaromycosis using population pharmacokinetics. C-reactive protein (CRP) was found to significantly affect voriconazole plasma concentrations. Optimization of initial dosing based on CRP levels may be useful to guide voriconazole dosing in clinical practice. The mortality rate in non-HIV talaromycosis is higher than in the HIV population, which may be due to the nonspecific and complex clinical manifestations. Failure to initiate antifungal treatment in a timely manner often results in poor prognosis and even death. The course of treatment is protracted, unclear, and depends on the immune status of the patient. Diagnosis and treatment of talaromycosis remain a challenge. Optimization of diagnostic tools and treatment regimens to ensure early detection and prompt antifungal treatment should be considered.

Remote sensing of tropical riverine water quality using sentinel-2 MSI and field observations

Monitoring the water quality as well as assessing its ecological status, both in coastal and inland environments, are essential tasks and pose serious environmental challenges. Although both field measurements and observations from permanent measuring stations may be available, the advent of modern remote sensors, such as MSI (MultiSpectral Instrument), on board the Sentinel-2 satellite, has made it possible to obtain inland biogeochemical products at high spatial (10 m) and temporal (5-days) resolutions. However, validating Sentinel-2 derived water quality estimations in tropical riverine and costal water is an ongoing effort.This study presents one of the first attempts to locally adapt and validate the C2RCC atmospheric processor for the inversion of IOPs to water quality parameters of productive tropical riverine waters in South East Asia using a time series of 65 Sentinel-2 MSI images from 2018 to 2021. We developed locally adapted relationships between C2X-Nets-derived inherent optical properties (IOPs) and surface reflectances with field observations of chl-a concentration, colored dissolved organic matter (CDOM), turbidity, transparency, and in situ reflectance spectra. Results have been validated against 3-years long time series of observations collected at six monitoring stations of the Metropolitan Waterworks Authority (MWA) of Thailand covering approximately 130 km-long stretch of the Chao Phraya river.Locally adapted C2X-Net processor showed good performances in predicting the chl-a concentrations, turbidity and Secchi disk depth. However, relatively low performance was noted for C2X-Nets processor in predicting CDOM absorption. During the period 2018–2021, the temporal trends of chl-a concentration and turbidity showed a clear seasonal pattern with peak turbidity values in the wet seasons. Spatial pattern of retrieved water quality products showed a noticeable change in correspondence with the built-up area of Bangkok. Even if elevated chl-a concentrations have been generally observed all year around, highest peaks have been observed in the dry and at beginning of the wet seasons.To the best knowledge of the authors, our findings firstly demonstrated the integration potential of C2RCC and satellite-retrieved water quality estimations into existing national water quality monitoring network in the context of water resources management and decision-making in the tropical Southeast Asian countries.

Analysis of Cathepsin-L and Cathepsin-B Gene Expression in Embryonated Eggs of Fasciola gigantica and Effect of Various Protease Inhibitors on Miracidial Hatching

Background: Fasciola gigantica is a helminth parasite of veterinary importance and a constraint on the growth and productivity of domestic livestock in the tropical countries of Asia and Africa. Present study aimed at determining the expression of four cysteine protease genes including cathepsin (cat) L-1 D and cat-Bs in the embryonated egg stage of F. gigantica by polymerase chain reaction (PCR). In addition to the analysis of expression of the above genes in the embryonated eggs, inhibition of in vitro hatching of the miracidia from the eggs was carried out using three protease inhibitors viz. serine, cysteine and leucine aminopeptidase inhibitors to understand the possible role of these proteases in the hatching of the miracidia from the eggs. Methods: Cat- L-1D, cat B-1, cat B-2 and cat B-3 genes were amplified by reverse transcriptase and quantitative-PCR, respectively for determining their expression in the embryonated eggs. Inhibition of in vitro hatching of the miracidia from the eggs was carried out by exposing the embryonated eggs to different concentrations of iodoacetamide, phenyl methyl sulphonyl fluoride and bestatin as cysteine, serine and leucine aminopeptidase inhibitors. Result: Results showed that cat L1-D, cat B-1 and cat B-3 genes were expressed at the embryonated egg stage but cat B-2 gene was not expressed at this stage of the parasite. Iodoacetamide and phenyl methyl sulphonyl fluoride (cysteine and serine protease inhibitors) inhibited the miracidial hatching at different concentrations, indicating probable role of cysteine and serine proteases in its hatching process. However, leucine aminopeptoidase does not seem to influence the miracidial hatching from the eggs as bestatin did not inhibit its hatching.

Hydrogel Containing Borassus flabellifer L. Male Flower Extract for Antioxidant, Antimicrobial, and Anti-Inflammatory Activity.

Borassus flabellifer L. is a plant in Arecaceae family, widely distributed and cultivated in tropical Asian countries. The purpose of this study was to identify the bioactive compounds of B. flabellifer L. male flower ethanolic extract and investigate the antioxidant, anti-inflammatory, and antibacterial activities against Cutibacterium acnes. Total phenolic compounds and total flavonoids in B. flabellifer L. male flower ethanolic extract were determined by the Folin–Ciocalteu method and aluminum chloride colorimetric assay, respectively. Active substances in the extract and their quantities were analyzed by liquid chromatography and mass spectrometry (LC–MS/MS). The antioxidant evaluation was carried out using DPPH, ABTS free radical scavenging assays, and FRAP assay. C. acnes inhibitory activity was performed by the broth microdilution method. Anti-inflammatory activity was determined by the protein denaturation assay. In addition, gel containing different amounts of B. flabellifer L. male flower extract was formulated. The physical stability of the gel was observed by measuring viscosity and pH after six heating and cooling cycles, as well as 1-month storage at 4, 30, and 45 °C. The total phenolic content in the extract was 268.30 ± 12.84 mg gallic acid equivalent/g crude dry extract. The total flavonoid contents in the extract were 1886.38 ± 55.86 mg quercetin equivalent/g extract and 2884.88 ± 128.98 mg EGCG equivalent/g extract, respectively. The LC–MS/MS analysis revealed the presence of gallic acid, coumarin, and quercetin and the concentrations of quercetin, coumarin, and gallic acid in B. flabellifer male flower ethanolic extract were 0.912, 0.021, and 1.610 µg/mL, respectively. DPPH and ABTS antioxidant assays indicated that the B. flabellifer L. male flower extract had IC50 values of 31.54 ± 0.43 and 164.5 ± 14.3 µg/mL, respectively. FRAP assay revealed that the B. flabellifer male flower extract had high ferric ion reducing power. The extract was able to inhibit C. acnes bacteria with a minimum inhibitory concentration (MIC) of 250 mg/mL. At 250 and 500 µg/mL, the extract demonstrated the highest anti-inflammatory activity. The gel containing 31.25% w/w and 62.5% w/w showed good physical stability after six heating and cooling cycles, as well as 1-month storage.

The role of non-pharmaceutical interventions on influenza circulation during the COVID-19 pandemic in nine tropical Asian countries.

BackgroundLow global influenza circulation was reported during the coronavirus‐19 pandemic. We explored relationships between non‐pharmaceutical interventions (NPIs) and influenza in tropical Asian countries.MethodsUsing World Health Organization (WHO) surveillance data from 2015 to 2019 and the WHO shiny app, we constructed expected seasonal influenza epidemic curves from March 2020 to June 2021 and compared the timing, and average percent positivity with observed data. We used multivariate regression to test associations between ordinal NPI data (from the Oxford Stringency Index) 4 weeks before the expected 2020/21 epidemics and present adjusted incidence rate ratio (IRR) or relative proportion ratio (RPR) and 95% confidence intervals (CI).ResultsData from nine countries predicted 18 seasonal epidemics; seven were observed. Five started 6–24 weeks later, and all were 4–21 weeks shorter than expected. Five epidemics had lower maximum peak values (percent positivity), and all but one had lower average percent positivity than expected. All countries implemented NPIs. Each increased level of school closure reduced risk of an epidemic by 43% (IRR = 0.57, CI: 0.34, 0.95). Each increased level of canceling public events reduced the average percent positivity across the season by 44% (RPR = 0.56, CI: 0.39, 0.82) and each increased level in restricting internal movements reduced it by 41% (RPR = 0.59, CI: 0.36, 0.96). Other NPIs were not associated with changes.ConclusionsAmong nine countries, the 2020/21 seasonal epidemics were delayed, shorter, and less intense than expected. Although layered NPIs were difficult to tease apart, school closings, canceling public events, and restricting internal movements before influenza circulation seemed to reduce transmission.

Long‐term changes in paddy soil fertility in tropical Asia after 50 years of the Green Revolution

AbstractOver 50 years of the Green Revolution since the 1960s, the global population has increased by 2.5 times, cereal production by 3.3 times and the use of N, P and K fertilisers by 9.4, 4.2 and 4.3 times, respectively. Information is still limited, however, on the influence of these impacts on the fertility status of agricultural soils. Here we investigated the influence of the Green Revolution on 142 paddy soils in three tropical Asian countries, that is, Thailand, the Philippines and Malaysia, during the given period by repeated soil sampling in the 1960s and 2010s at or near the same locations. We revealed that the phytoavailablility indices of three macronutrients – N, P and K, that is, available P, exchangeable K and total N, showed 743% (p < 0.01), 12% and 1% increase on average, respectively, while total C showed 9% decline. Comprehensive investigation of overall fertility status by factor analysis using 11 soil parameters suggested that only the factor scores associated with ‘available P status’ increased drastically in all the three countries (p < 0.01) whereas those associated with ‘organic matter and N contents’ and ‘inherent potentiality’ did not exhibit any consistent changes among the countries. In conclusion, intensive soil/fertiliser management systems under the Green Revolution have successfully improved the nutrient status, especially P status, of paddy soils with slight decrease of soil organic matter over the last 50 years, while a large amount of nutrients applied, especially N and K, has been released from soil to the outer environments. Conversion to a high‐efficiency system of external nutrient inputs with organic matter‐conserving strategies is, therefore, urgently required to secure sustainable food production while restoring the environment during the coming decades.Highlights Paddy soils from 142 locations in three tropical Asian countries were repeatedly surveyed in the 1960s and 2010s. Available P increased by 8.4 times, that of exchangeable K and total N showed 12% and 1% increase, while organic matter level showed 9% decline. Factor analysis indicated significant increase of the factor scores for those associated with ‘available P status’. A high‐efficiency system with organic matter‐conserving strategies is to be established for both sustainable food production and restoration of the environment.

Spatio-temporal variation of microplastic along a rural to urban transition in a tropical river

Microplastic pollution is widely recognised as a global issue, posing risks to natural ecosystems and human health. The combination of rapid industrial and urban development and relatively limited environmental regulation in many tropical countries may increase the amount of microplastic entering rivers, but basic data on contamination levels are lacking. This is especially the case in tropical South East Asian countries. In this paper, the abundance, composition and spatio-temporal variation of microplastic in the Langat River, Malaysia, were assessed, and the relationship between microplastic concentration and river discharge was investigated. Water samples were collected over a 12-month period from 8 sampling sites on the Langat, extending from forested to heavily urbanised and industrial areas. All 508 water samples collected over this period contained microplastic; mean concentration across all sites and times was 4.39 particles/L but extended up to 90.00 particles/L in some urban tributaries. Most microplastics were secondary in origin, and dominated by fibres. Microplastic counts correlated directly with river discharge, and counts increased and decreased in response to changes in flow. A time-integrated assessment of the microplastic load conveyed by the Langat suggested that the river is typically (50 % of the time) delivering around 5 billion particles per day to the ocean. The positive correlation between the concentration of microplastics and suspended sediments in the Langat suggested that continuously logging turbidity sensors could be used to provide better estimates of microplastic loads and improve assessment of human and ecological health risks.

Effectiveness of Protected Areas in the Pan-Tropics and International Aid for Conservation

Evaluation of the effectiveness of protected areas is critical for forest conservation policies and priorities. We used 30 m resolution forest cover change data from 1990 to 2010 for ~4000 protected areas to evaluate their effectiveness. Our results show that protected areas in the tropics avoided 83,500 ± 21,200 km2 of deforestation during the 2000s. Brazil’s protected areas have the largest amount of avoided deforestation at 50,000 km2. We also show the amount of international aid received by tropical countries compared to the effectiveness of protected areas. Thirty-four tropical countries received USD 42 billion during the 1990s and USD 62 billion during the 2000s in international aid for biodiversity conservation. The effectiveness of international aid was highest in Latin America, with 4.3 m2/USD, led by Brazil, while tropical Asian countries showed the lowest average effect of international aid, reaching only 0.17 m2/USD.

Phytochemical Profile and Pharmacological Aspects of Achyranthes aspera Linn- An Overview

Background: Achyranthes asperaLinn, commonly known as Apamarga in Ayurveda (Prickly Chaff flower in English, Aghara in Hindi, Aghada in Marathi), is aannual, perennial herb that belong to Family Amaranthaceae and Genus Achyranthes consisting of several species which are popular as folk remedies. Certain ayurvedic and Unani practitioners use various parts of plant to treat various diseases.The present review aims to provide up-to-date information on different aspects of plant involving its botanical description, phytochemistry and bioactivities of different extractsto assess its therapeutic potential as a valuable source of natural compounds with beneficial effects on human health.
 Methodology: Systematic search of scientific databases like Google, Google scholar, PubMed, Web of Science, Science Direct, SciFinder, Springer link were used to find potentially significant scientific research and reports of Achyranthes asperaLinnusing combination of relevant keywords.
 Results: Achyranthes aspera Linn is a popular folk remedy in the traditional medicinal system in all tropical Asian and African countries. So far,58 important compounds have been isolated and identified from various parts of plant. These isolated constituents are mainly flavonoids, tannins, terpenoids, saponins, phytosterols; phenolic compounds etc which posseses activities like anti-inflammatory, antimicrobial, anti-oxidant, hypoglycemic, antihyperlipidemic, spermicidal and other various important medicinal properties.
 Conclusion: Even though this plant consists of a wide range of phytochemicals and evaluated forbiological activities using various in-vitro and in-vivo models but they are limited. More attention should be paid to identify mechanisms that underlie beneficial therapeutic potential.It is essential to conduct the next level of research, by extending pharmacological to design novel drugs.

In vitro multiplication protocol for Curcuma mangga : Studies on carbon, cytokinin source and explant size

Mango ginger (Curcuma mangga Valeton & Zijp.) is an underutilized rhizomatous species that has been valued in tropical Asian countries as a source of vegetable, spice, salad, medicine, and essential oil. This species is hardy and requires less care for obtaining good yields. Rhizomes are the commonly used propagules for the species, which are also the economic part of the crop. Huge quantity of seed rhizomes is required to promote this crop in larger areas. An efficient in vitro multiplication protocol is one of the options to meet the planting material requirement. Effects of carbon source (glucose, fructose and sucrose) and concentration (1 and 3%, w/v), cytokinins (BAP and meta topolin) and concentration (1 mg/L and 2 mg/L), size of explants (one/ two/ three bud) and IBA treatment (0, 250, 500 and 1,000 mg/L) for concurrent ex vitro rooting cum hardening were studied. Results revealed that for facilitating efficient multiplication, the medium should be supplemented with glucose (3%) as a carbon source and meta topolin (1 mg/L) as cytokinin. Two-bud explant should be used for subculture as it promoted superior shoot proliferation. Concurrent ex vitro rooting cum hardening was possible even without auxin treatment. The present protocol could be useful for large-scale production of quality planting material of this underexploited tropical species.