On the recurrence of Noctiluca scintillans bloom in Minnie Bay, Port Blair: Impact on water quality and bioactivity of extracts

A Noctiluca scintillans bloom in the coastal waters of Minnie Bay, Port Blair was studied. Physico-chemical and biological properties of bloom-infested waters were monitored during the bloom period lasting five days. The bloom appeared as a green streak along the entire coastline of Minnie Bay, with cell counts of 17 103 cells/ l. The bloom appeared as a sudden spurt in cell number and persisted for a period of 48 h. The antibacterial properties of extracts from this algal species were also investigated. Conspicuously, the bloom inhibited the common resident phytoplankton species. Total suspended solids showed a marked increase during day-one of bloom compared to ambient levels. The bloom appeared to be limited by dissolved inorganic nitrogen species availability. The differential growth of phytoplankton reveals the involvement of specific trigger factors for such blooms. From the present viewpoint, micro-scale studies on hydrobiological factors preceding the onset of bloom would reveal what cycle of events lead to a bloom and the causal factors of such blooms. However, prediction of occurrence of such blooms and in situ measurements are practical difficulties to be addressed. Since a similar bloom was reported earlier in 2001, it is worthwhile to keep a watch and investigate as to whether there is any anthropogenic or environmental cause for the recurrence of the bloom

A role for the mevalonate pathway in early plant symbiotic signaling

Rhizobia and arbuscular mycorrhizal fungi produce signals that are perceived by host legume receptors at the plasma membrane and trigger sustained oscillations of the nuclear and perinuclear Ca(2+) concentration (Ca(2+) spiking), which in turn leads to gene expression and downstream symbiotic responses. The activation of Ca(2+) spiking requires the plasma membrane-localized receptor-like kinase Does not Make Infections 2 (DMI2) as well as the nuclear cation channel DMI1. A key enzyme regulating the mevalonate (MVA) pathway, 3-Hydroxy-3-Methylglutaryl CoA Reductase 1 (HMGR1), interacts with DMI2 and is required for the legume-rhizobium symbiosis. Here, we show that HMGR1 is required to initiate Ca(2+) spiking and symbiotic gene expression in Medicago truncatula roots in response to rhizobial and arbuscular mycorrhizal fungal signals. Furthermore, MVA, the direct product of HMGR1 activity, is sufficient to induce nuclear-associated Ca(2+) spiking and symbiotic gene expression in both wild-type plants and dmi2 mutants, but interestingly not in dmi1 mutants. Finally, MVA induced Ca(2+) spiking in Human Embryonic Kidney 293 cells expressing DMI1. This demonstrates that the nuclear cation channel DMI1 is sufficient to support MVA-induced Ca(2+) spiking in this heterologous system

Review of natural fibre-reinforced hybrid composites

Natural fibre-reinforced hybrid composites which contain one or more types of natural reinforcement are gaining increasing research interest. This paper presents a review of natural fibre-reinforced hybrid composites. Both thermoplastic and thermoset composites reinforced by hybrid/synthetic fibres or hybrid/hybrid fibres are reviewed. The properties of natural fibres, the properties and processing of composites are summarised

Genetic Variants of APOL1 Are Major Determinants of Kidney Failure in People of African Ancestry With HIV

INTRODUCTION: Variants of the APOL1 gene are associated with chronic kidney disease (CKD) in people of African ancestry, although evidence for their impact in people with HIV are sparse. METHODS: We conducted a cross-sectional study investigating the association between APOL1 renal risk alleles and kidney disease in people of African ancestry with HIV in the UK. The primary outcome was end-stage kidney disease (ESKD; estimated glomerular filtration rate [eGFR] of 30 mg/mmol), and biopsy-proven HIV-associated nephropathy (HIVAN). Multivariable logistic regression was used to estimate the associations between APOL1 high-risk genotypes (G1/G1, G1/G2, G2/G2) and kidney disease outcomes. RESULTS: A total of 2864 participants (mean age 48.1 [SD 10.3], 57.3% female) were genotyped, of whom, 354 (12.4%) had APOL1 high-risk genotypes, and 99 (3.5%) had ESKD. After adjusting for demographic, HIV, and renal risk factors, individuals with APOL1 high-risk genotypes were at increased odds of ESKD (odds ratio [OR] 10.58, 95% CI 6.22–17.99), renal impairment (OR 5.50, 95% CI 3.81–7.95), albuminuria (OR 3.34, 95% CI 2.00–5.56), and HIVAN (OR 30.16, 95% CI 12.48–72.88). An estimated 49% of ESKD was attributable to APOL1 high-risk genotypes. CONCLUSION: APOL1 high-risk genotypes were strongly associated with kidney disease in people of African ancestry with HIV and accounted for approximately half of ESKD cases in this cohort

Sickle Cell Trait and Kidney Disease in People of African Ancestry With HIV

Introduction: Sickle cell trait (SCT) has been associated with chronic kidney disease (CKD) in African Americans, although evidence for its impact in Africans and people with HIV is currently lacking. We conducted a cross-sectional study investigating the association between SCT and kidney disease in people of African ancestry with HIV in the UK. Methods: The primary outcome was estimated glomerular filtration rate (eGFR) 50 mg/mmol), and albuminuria (albumin-to-creatinine ratio >3 mg/mmol). Multivariable logistic regression was used to estimate the associations between SCT and kidney disease outcomes. Results: A total of 2895 participants (mean age 48.1 [SD 10.3], 57.2% female) were included, of whom 335 (11.6%) had SCT and 352 (12.2%) had eGFR <60 ml/min per 1.73 m2. After adjusting for demographic, HIV, and kidney risk factors including APOL1 high-risk genotype status, individuals with SCT were more likely to have eGFR <60 ml/min per 1.73 m2 (odds ratio 1.62 [95% CI 1.14–2.32]), eGFR <90 ml/min per 1.73 m2 (1.50 [1.14–1.97]), and albuminuria (1.50 [1.09–2.05]). Stratified by APOL1 status, significant associations between SCT and GFR <60 ml/min per 1.73 m2, eGFR <90 ml/min per 1.73 m2, proteinuria, and albuminuria were observed for those with APOL1 low-risk genotypes. Conclusion: Our results extend previously reported associations between SCT and kidney disease to people with HIV. In people of African ancestry with HIV, these associations were largely restricted to those with APOL1 low-risk genotypes

Dynamic mechanical, thermal and wear analysis of Ni-P coated glass fiber/Al₂O₃ nanowire reinforced vinyl ester composite

Hybrid polymer composites nowadays are increasingly used in many engineering products which are subjected to wear, dynamic mechanical and thermal applications. So in the present study, we have investigated the evaluation of dynamic mechanical, thermal and wear properties of vinyl ester hybrid composite strengthened with Ni-P coated E-glass fiber and Al₂O₃ nanowires as reinforcement at different concentrations. Nickel-Phosphorus is plated over the glass fiber substrate by means of the electroless plating method. The best optimum bath composition was determined after many trials and used for the proper plating process. From the outcome of the result, it is clear that the storage modulus has a trend to increase with increase in the concentration of Ni-P coated glass fiber (GF) and further increases when Al₂O₃ nanowires are used as the reinforcement. The glass transition temperature is also shifted to the higher temperature in the process. From the thermogravimetric analysis, it is clear that the thermal stability of the composite steps up with the addition of Al₂O₃ nanowires as fillers and Ni-P/GF as reinforcement. The wear properties are analyzed and the morphology of the coated and worn-out surfaces are studied by means of scanning electron micrographs and optical microscope images. Keywords: Hybrid composite, Al₂O₃ nanowire, Electroless Ni-P, Dynamic mechanical analysis, Wea