Fine-Root Distribution and Soil Physicochemical Property Variations in Four Contrasting Urban Land-Use Types in South Korea.

Urbanization and associated forest conversions have given rise to a continuum of native (forest fragments) and modified (artificial grasslands and perennial ecosystems) land-use types. However, little is known about how these shifts affect soil and fine-root compartments that are critical to a functioning carbon and nutrient circulation system. In this study, soil physicochemical properties, fine-root mass, and vertical distribution patterns were investigated in four representative urban land-use types: grassland (ZJ), perennial agroecosystem (MP), broadleaf deciduous forest patch (QA), and coniferous evergreen forest patch (PD). We quantified the fine-root mass in the upper 30 cm vertical profile (0-30 cm) and at every 5 cm depth across three diameter classes (<2 mm, 2-5 mm, and <5 mm). Soil physicochemical properties, except for phosphorus, nitrogen, ammonium nitrogen, and sodium cations, varied significantly across land-use types. The total root biomass (<5 mm) decreased in the order of QA (700.3 g m-2) > PD (487.2 g m-2) > ZJ (440.1 g m-2) > MP (98.3 g m-2). The fine-root mass of ZJ and MP was correlated with soil nutrients, which was attributed to intensive management operations, while the fine-root mass of QA and PD had a significant relationship with soil organic matter due to the high inputs from forest litter. Very fine roots (<2 mm) presented a distinct decremental pattern with depth for all land-use types, except for MP. Very fine roots populated the topmost 5 cm layer in ZJ, QA, and PD at 52.1%, 49.4%, and 39.4%, respectively. Maintaining a woody fine-root system benefits urban landscapes by promoting soil stabilization, improving ground infiltration rates, and increasing carbon sequestration capacity. Our findings underscore the importance of profiling fine-root mass when assessing urban expansion effects on terrestrial ecosystems.

Host immune response against DENV and ZIKV infections.

Dengue is a major public health concern, affecting almost 400 million people worldwide, with about 70% of the global burden of disease in Asia. Despite revised clinical classifications of dengue infections by the World Health Organization, the wide spectrum of the manifestations of dengue illness continues to pose challenges in diagnosis and patient management for clinicians. When the Zika epidemic spread through the American continent and then later to Africa and Asia in 2015, researchers compared the characteristics of the Zika infection to Dengue, considering both these viruses were transmitted primarily through the same vector, the Aedes aegypti female mosquitoes. An important difference to note, however, was that the Zika epidemic diffused in a shorter time span compared to the persisting feature of Dengue infections, which is endemic in many Asian countries. As the pathogenesis of viral illnesses is affected by host immune responses, various immune modulators have been proposed as biomarkers to predict the risk of the disease progression to a severe form, at a much earlier stage of the illness. However, the findings for most biomarkers are highly discrepant between studies. Meanwhile, the cross-reactivity of CD8+ and CD4+ T cells response to Dengue and Zika viruses provide important clues for further development of potential treatments. This review discusses similarities between Dengue and Zika infections, comparing their disease transmissions and vectors involved, and both the innate and adaptive immune responses in these infections. Consideration of the genetic identity of both the Dengue and Zika flaviviruses as well as the cross-reactivity of relevant T cells along with the actions of CD4+ cytotoxic cells in these infections are also presented. Finally, a summary of the immune biomarkers that have been reported for dengue and Zika viral infections are discussed which may be useful indicators for future anti-viral targets or predictors for disease severity. Together, this information appraises the current understanding of both Zika and Dengue infections, providing insights for future vaccine design approaches against both viruses.

Production of nitrosamines from ephedrine, pseudoephedrine and extracts of Ephedra foliata under physiological conditions.

N-Nitrosoephedrine (NEP) and N-nitrosopseudoephedrine (NPEP) were synthesised at 5 degrees C using different concentrations of various acids. The reaction with acetic acid gave the highest yield (85%) of N-nitrosamine. Ephedrine and pseudoephedrine were reacted with nitrite under physiological conditions (37 degrees C, pH 1-3) to form NEP and NPEP. The yield of NEP, which is a known carcinogen, and NPEP were the highest (18.5%) at pH 2. Aqueous and alcoholic extracts of Ephedra foliata (100 g dry wt), nitrosated under physiological conditions, produced 0.77 mg and 8.3 mg, respectively, as total nitrosamines. This indicated the potential of the nitrosamine formation from the plant extracts specified.

N-nitrosoephedrine and N-nitrosopseudoephedrine: their dissolution, absorption, blood clearance and elimination studies.

Dissolution and absorption rates (in vitro); clearance from blood and elimination rates of N-nitrosoephedrine (NEP) and N-nitrosopseudophedrine (NPEP) in mice were determined. The two isomers obeyed first-order kinetics and from the slope of the regression line, the rate constant for each study was obtained. These constants were 0.023, 0.038 min-1 (dissolution); 0.192, 0.225 h-1 (stomach absorption); 2.898, 1.980 h-1 (intestinal absorption); 0.33, 0.55 h-1 (blood clearance) and 0.373, 0.393 h-1 (elimination from whole animal) of NEP and NPEP, respectively, and were tested by Student's t-test. Significant differences in the dissolution, absorption and blood clearance rates of NPEP from those of NEP have been observed (P less than 0.05-0.01). These differences are expected to exert their influence on the metabolic rates and the carcinogenic and/or spectral properties of NEP and NPEP, in a related pattern.

Study of Mutations in ß-Thalassemia Trait among Blood Donors in Eastern Uttar Pradesh.

BACKGROUND: Knowledge on distribution of different mutations of thalassaemia, which are prevalent in a particular area, is a prerequisite for prenatal diagnosis. OBJECTIVES: Studying mutations in ß - thalassaemia trait among blood donors in eastern Uttar Pradesh, India. MATERIAL AND METHODS: One thousand non - remunerated voluntary blood donors who were between 18 - 40 years of age, were included in the study. Both replacement and voluntary healthy blood donors were included. 4ml of venous blood was collected and it was stored at 4°C. Complete Blood Count (CBC), Haemoglobinopathy Screening and Molecular Analysis by ARMS - PCR (Amplification Refractory Mutation System - PCR) were done. Screening for ß thalassaemia was done in a blood bank by using D - 10, Bio Rad, which was based on High Performance Liquid Chromatography (HPLC). RESULTS: Twenty Eight subjects with ß- thalassaemia trait were found among 1000 voluntary blood donors. IVS 1-5 (G-C) mutation was most common type (50%), followed by FS 8/9 (+G) 25% which was the second most common type. In our study, a rare mutation of CD 16 (-C) was also found. Out of 14 subjects who had IVS 1-5 (G-C) mutation (most common), six were from Varanasi (6/261) and five of them were Sindhis. It was seen that FS 41/42 (TCTT) mutation was distributed among all groups of populations which had higher prevalences of ß-thalassaemia trait. CONCLUSION: A comprehensive knowledge on beta thalassaemia mutations is necessary for determining a prenatal diagnosis. The occurrence of mutations may vary according to geographic region. Therefore, this study dealt with current problem of unknown mutations, in order to avoid complications.

Why are secondary metabolites (natural products) biosynthesized?

We adopt the definition of a natural product as a substance that has no known role in the internal economy of the producing organism. The literature abounds with conflicting views for the existence of such natural products. We propose that all such structures serve the producing organisms by improving their survival fitness. We argue that this conclusion is necessitated by the fact that natural products are normally complex structures, whose biosynthesis is programmed by many kilobases of DNA. If it were otherwise, the pressures of Darwinian natural selection would have precluded the expenditure of so much metabolic energy in their construction and the development of such complexity. We further conclude that a natural product improves the producer's survival fitness by acting at specific receptors in competing organisms. Current studies of natural products interacting with receptors support this view, in terms of both the sophistication of the molecule/molecule recognition and the mechanistic details of physiological action. By the application of Occam's razor and general weaknesses of other hypotheses, these other hypotheses are rejected. It is a consequence of our proposal that natural product/receptor interactions of sophistication comparable to enzyme/substrate interactions will be commonplace. Additionally, structures that are candidates to interact with known receptors (e.g., double helical DNA) can on occasion be suggested by inspection of the structures. A range of evidence to support the general conclusions is presented.