Bounds for the Second Hankel Determinant of Certain Univalent Functions

The estimates for the second Hankel determinant a_2a_4-a_3^2 of analytic function f(z)=z+a_2 z^2+a_3 z^3+...b for which either zf'(z)/f(z) or 1+zf"(z)/f'(z) is subordinate to certain analytic function are investigated. The estimates for the Hankel determinant for two other classes are also obtained. In particular, the estimates for the Hankel determinant of strongly starlike, parabolic starlike, lemniscate starlike functions are obtained

Coefficient estimates for bi-univalent Ma-Minda starlike and convex functions

Estimates on the initial coefficients are obtained for normalized analytic functions $f$ in the open unit disk with $f$ and its inverse $g=f^{-1}$ satisfying the conditions that $zf'(z)/f(z)$ and $zg'(z)/g(z)$ are both subordinate to a starlike univalent function whose range is symmetric with respect to the real axis. Several related classes of functions are also considered, and connections to earlier known results are made

Initial Coefficients of Biunivalent Functions

An analytic function f defined on the open unit disk is biunivalent if the function f and its inverse f-1 are univalent in . Estimates for the initial coefficients of biunivalent functions f are investigated when f and f-1, respectively, belong to some subclasses of univalent functions. Some earlier results are shown to be special cases of our results

Development of an in planta infection system for the early detection of Ganoderma spp. in oil palm

Basal stem rot (BSR) disease caused by the white rot fungus, Ganoderma spp. is a serious threat to the growth and production of oil palm (Elaeis guineensis Jacq.). Traditional in planta infection technique using inoculated rubber wood block can be inaccurate and time-consuming. In this study, a new in planta infection system was developed to detect early symptoms of BSR in young oil palm. One month old clones of oil palm plantlets were artificially infected with pathogenic fungal inoculum (G. boninense GBLS isolate) at three levels of treatments (control, T1; wounded but not infected, T2; wounded and infected, T3) for a period of 8 days. Significant declines in leaf chlorophyll content (from 32.59 to 12.60 SPAD), increases in disease severity index (DSI) values (from 5.56 to 70.37 %) and increased amounts of GBLS DNA (from 0.2 to 116.1 ng μl-1) were progressively detected in T3 as compared to the T1 and T2 plantlets. The internal stem tissues of T3 plantlets were observed to deteriorate gradually from Day 2 post inoculation (DPI) and were severely colonized and damaged by 8 DPI. The potential defence mechanism of total phenolic content peaked on 6 DPI (3.7 mg g-1) in T3 plantlets and reduced thereafter. The data obtained is consistent with BSR symptoms reported in mature oil palm and is indicative of the reproducibility and reliability of an in planta infection system as an effective approach to detect early BSR symptoms in oil palm

Water droplet accumulation and motion in PEM (Proton Exchange Membrane) fuel cell mini-channels

Effective water management is one of the key strategies for improving low temperature Proton Exchange Membrane (PEM) fuel cell performance and durability. Phenomena such as membrane dehydration, catalyst layer flooding, mass transport and fluid flow regimes can be affected by the interaction, distribution and movement of water in flow plate channels. In this paper a literature review is completed in relation to PEM fuel cell water flooding. It is clear that droplet formation, movement and interaction with the Gas Diffusion Layer (GDL) have been studied extensively. However slug formation and droplet accumulation in the flow channels has not been analysed in detail. In this study, a Computational Fluid Dynamic (CFD) model and Volume of Fluid (VOF) method is used to simulate water droplet movement and slug formation in PEM fuel cell mini-channels. In addition, water slug visualisation is recorded in ex situ PEM fuel cell mini-channels. Observation and simulation results are discussed with relation to slug formation and the implications to PEM fuel cell performance

Partial pulmonary embolization disrupts alveolarization in fetal sheep

BACKGROUND: Although bronchopulmonary dysplasia is closely associated with an arrest of alveolar development and pulmonary capillary dysplasia, it is unknown whether these two features are causally related. To investigate the relationship between pulmonary capillaries and alveolar formation, we partially embolized the pulmonary capillary bed. METHODS: Partial pulmonary embolization (PPE) was induced in chronically catheterized fetal sheep by injection of microspheres into the left pulmonary artery for 1 day (1d PPE; 115d gestational age; GA) or 5 days (5d PPE; 110-115d GA). Control fetuses received vehicle injections. Lung morphology, secondary septal crests, elastin, collagen, myofibroblast, PECAM1 and HIF1 alpha abundance and localization were determined histologically. VEGF-A, Flk-1, PDGF-A and PDGF-R alpha mRNA levels were measured using real-time PCR. RESULTS: At 130d GA (term approximately 147d), in embolized regions of the lung the percentage of lung occupied by tissue was increased from 29 +/- 1% in controls to 35 +/- 1% in 1d PPE and 44 +/- 1% in 5d PPE fetuses (p < 0.001). Secondary septal crest density was reduced from 8 +/- 0% in controls to 5 +/- 0% in 1d PPE and 4 +/- 0% in 5d PPE fetuses (p < 0.05), indicating impaired alveolar formation. The deposition of differentiated myofibroblasts (23 +/- 1% vs 28 +/- 1%; p < 0.001) and elastin fibres (3 +/- 0% vs 4 +/- 0%; p < 0.05) were also impaired in embolized lung regions of PPE fetuses compared to controls. PPE did not alter the deposition of collagen or PECAM1. At 116d GA in 5d PPE fetuses, markers of hypoxia indicated that a small and transient hypoxic event had occurred (hypoxia in 6.7 +/- 1.4% of the tissue within embolized regions of 5d PPE fetuses at 116d compared to 0.8 +/- 0.2% of tissue in control regions). There was no change in the proportion of tissue labelled with HIF1 alpha. There was no change in mRNA levels of the angiogenic factors VEGF and Flk-1, although a small increase in PDGF-R alpha expression at 116d GA, from 1.00 +/- 0.12 in control fetuses to 1.61 +/- 0.18 in 5d PPE fetuses may account for impaired differentiation of alveolar myofibroblasts and alveolar development. CONCLUSIONS: PPE impairs alveolarization without adverse systemic effects and is a novel model for investigating the role of pulmonary capillaries and alveolar myofibroblasts in alveolar formation

Transforming food systems in Maritime Southeast Asia and Pacific Small Island Developing States to support food security and sustainable healthy diets

Food is one of the basic necessities for human life. Nutritious food is essential for human health and helps oneself live up to our best potential as productive members of society. In spite of this, 3 billion people are estimated to have limited access to nutrient-rich food, and there are 768 million undernourished people in the globe today. There are still concerns with food systems and food security, despite the fast economic transformation of low-and middle-income nations in Maritime Southeast Asia and Oceania over the past 10 years. These issues include dwindling agricultural land, deforestation, ineffective food supply networks, environmental degradation, changing and unhealthy diets, non-communicable diseases, disappearing cultural legacy, and ineffective policies. These problems are exacerbated by climate change, natural hazards, and pandemic shocks. This review explores the perspectives of food systems that relates to all the elements and activities in transforming agri-food industry. In this paper, we discuss the challenges and solutions to transforming food systems in this region to achieve a sustainable and healthy diet for all, with the perspective of bringing the region closer toward the UN sustainable development goals. This paper is an outcome of the deliberations that took place during the Food Security in Small Islands and Developing States workshop in 2020. It also includes insights from subsequent expert group sessions that focused on the following topics: Agriculture and Food Systems; Nutrition, Health, and Culture; Innovations and Digitalization in Food Systems; as well as Policies Coordination and Future Shocks