The population of damselflies (Agriocnemis sp.) during growing phase of paddy at Kawasan Sawah Tengah Padang, Merlimau Melaka / Syaza Izzati Mat Sod

This study was aimed to study relationship between populations of Damselflies (Agriocnemis sp.) in growing phase of paddy by weekly and its relation with the diversity of alternate host plant in paddy farming surrounding area. This study was conducted in paddy field at Kawasan Sawah Tengah Padang, Merlimau, Melaka. The samplings visits were made starting from the 20th July until 11th September 2018 was covered 10 weeks of data collections periods. One sampling method is used which is yellow sticky trap and set up randomly in field. Only one species that was recorded which damselflies (Agriocnemis sp.) order of Odonata. A few of species host plant also recorded comprising Perennial Water Primrose (Ludwigia perennis L. Onagraceae), Jungle rice (Echinochloa colona), Fringe-rush (Fimbristylis dichotoma), Shrubby False Buttonweed (Spermacoce verticillata), Pill-Bearing Spurge (Euphorbia Hirta syn. E. pilulifera), Airport grass (Chloris barbata Sw), Rumput Minyak (Panicum milliforme) and Broadleaved Bristle Grass (Setarid palmifolia). Results indicated that the population of Damselflies (Agriocnemis sp.) by weekly during the growing phase of paddy has no significance since (p>0.05). Meanwhile, there is no significance relationship between the numbers of population damselflies with the diversity of host in paddy farming surrounding area. As a result, farmer should ensure a good balance between the populations of damselflies and insect pest also host plant as unwanted weed during the various phases of paddy development without any appreciable loss in yield. An effective way is crucial to conserve, use and enhance biodiversity for sustainable food security

A Density Independent Formulation of Smoothed Particle Hydrodynamics

The standard formulation of the smoothed particle hydrodynamics (SPH) assumes that the local density distribution is differentiable. This assumption is used to derive the spatial derivatives of other quantities. However, this assumption breaks down at the contact discontinuity. At the contact discontinuity, the density of the low-density side is overestimated while that of the high-density side is underestimated. As a result, the pressure of the low (high) density side is over (under) estimated. Thus, unphysical repulsive force appears at the contact discontinuity, resulting in the effective surface tension. This tension suppresses fluid instabilities. In this paper, we present a new formulation of SPH, which does not require the differentiability of density. Instead of the mass density, we adopt the internal energy density (pressure), and its arbitrary function, which are smoothed quantities at the contact discontinuity, as the volume element used for the kernel integration. We call this new formulation density independent SPH (DISPH). It handles the contact discontinuity without numerical problems. The results of standard tests such as the shock tube, Kelvin-Helmholtz and Rayleigh-Taylor instabilities, point like explosion, and blob tests are all very favorable to DISPH. We conclude that DISPH solved most of known difficulties of the standard SPH, without introducing additional numerical diffusion or breaking the exact force symmetry or energy conservation. Our new SPH includes the formulation proposed by Ritchie & Thomas (2001) as a special case. Our formulation can be extended to handle a non-ideal gas easily.Comment: 24 pages, 21 figures. Movies and high resolution figures are available at http://v1.jmlab.jp/~saitoh/sph/index.htm

Survey of numerical methods for compressible fluids

The finite difference methods of Godunov, Hyman, Lax-Wendroff (two-step), MacCormack, Rusanov, the upwind scheme, the hybrid scheme of Harten and Zwas, the antidiffusion method of Boris and Book, and the artificial compression method of Harten are compared with the random choice known as Glimm's method. The methods are used to integrate the one-dimensional equations of gas dynamics for an inviscid fluid. The results are compared and demonstrate that Glimm's method has several advantages. 16 figs., 4 tables

A phylogenetic study of the Mongolian Tree Pipit (Anthus trivialis, Linnaeus, 1758) population based on mitochondrial DNA (mtDNA) genes

Our aim was to identify nucleotide polymorphisms, assess their distribution in haplotype diversity, and construct a phylogenetic tree by analyzing mtDNA markers of the Mongolian Tree Pipits(Anthus trivialis). We conducted this study using partial gene sequencesof mitochondrial marker genes, such as COI, Cyt-b, D-loop, andND2,to determine the genetic diversity of Mongolian Tree Pipits. We successfully amplified 2307 bp of the mitochondrial DNA fragments, including 469bp of COI, 435bp of Cyt-b, 554bp of D-loop and 846bp of ND2 from total 27 individuals of Mongolian (21) and Hungarian (6) populations of Anthus trivialis.The Hd value wasthe highest for ND2 (0.96) as compared with the other gene fragments in all populations, whileit was 0.94 in the Mongolian population. Moreover, the nucleotide diversity (Pi) ranged from 0.00234 to 0.004 in all population, it was observed that the Pi was between 0.00183 and 0.00376 in the Mongolian population. The phylogenetic tree based on combined mtDNA sequences revealed two mean clades.The probability value of the node supporting the posterior between these clades is 0.65,which suggests an indicative support in relationship between the two clades. Furthermore, phylogenetic analysis showed that Mongolian Tree Pipits do share common genetic characteristics with other populations and do not form distinct clusters. Keyword: Population genetics, haplotype, Anthus trivialis, Phylogenetics, Cyt-b, ND2, D-loop, COI;   INTRODUCTION The Tree Pipit (Anthus trivialis, Linnaeus, 1758) is a migratory bird belonging to the Motacillidae family within Passeriformes. This species faces significant challenges, particularly in Southeast Asian countries, where it has become a target of widespread hunting (Source). In recent years, the population of the Tree Pipit in Central Asia has experienced a notable decline, leading to its inclusion in the category of Globally Decreasing Populations according to the International Union for Conservation of Nature (IUCN) assessment for the year 2023 [1]. The genus Anthus, to which the Tree Pipit belongs, is a diverse group within the Motacillidae family, comprising 43 species. The Motacillidae family is recognized as one of the most widespread and species-rich families within Passeriformes, a testament to its members\u27 ecological diversity and adaptability [2, 3]. The challenges associated with determining the exact genetic relationships between birds in genusAnthus, such as the Tree Pipit (Anthus trivialis), due to inconsistencies in appearance and plumage, are indeed significant. The genus Anthus encompasses a diverse group of bird species, and the variations in their external characteristics can make it challenging to establish a precise genetic relationship[4]. Acomprehensive classification involved identifying four major groups: the Small-Bodied African Group are predominantly found in the African regions and are characterized by smaller body sizes; the Old Continental Group, reflecting the historical continuity of relatively large species, are distributed across Asia, Africa, and Europe; the Palearctic Migratory Group consist of species undertaking migration within the Palearctic region encompassing Europe, Asia, and North Africa; and the New Continental Group comprises of species found in North, Central, and South America and represent the Anthus species that have colonized the Americas [5].The Tree Pipit (Anthus trivialis) predominantly inhabits the temperate regions of Eurasia. The first study of the phylogeography of birds to determine the genetic basis of geographic location in birds established amethod based on mitochondrial DNA (mtDNA) [6], which initiated a method that explores the genealogical relationship of birds based on their geographical locations. The use of mtDNA in genetic and phylogeographic studies is widespread because of its high evolutionary intensity and minimal DNA degradation[7].Tree Pipit is a migratory egg-laying bird that is listed as a rare species in the Red Book of Mongolia. Therefore, it is necessary to conduct field and genetic research to determine the subspecies that are distributed in Mongolia. In this study, we focused on elucidating the nucleotide sequence of specific genes within the mtDNA of Tree Pipit. Proceeding from, this premise, we focused on conducting a comparative genetic analysis of Mongolian Tree Pipits in relation to other global populations to determine if differences, any, exist at the subspecies level, thus contributing valuable insights into the population genetics of Tree Pipit

Dusty gas with SPH - II. Implicit timestepping and astrophysical drag regimes

In a companion paper (Laibe & Price 2011b), we have presented an algorithm for simulating two-fluid gas and dust mixtures in Smoothed Particle Hydrodynamics (SPH). In this paper, we develop an implicit timestepping method that preserves the exact conservation of the both linear and angular momentum in the underlying SPH algorithm, but unlike previous schemes, allows the iterations to converge to arbitrary accuracy and is suited to the treatment of non- linear drag regimes. The algorithm presented in Paper I is also extended to deal with realistic astrophysical drag regimes, including both linear and non-linear Epstein and Stokes drag. The scheme is benchmarked against the test suite presented in Paper I, including i) the analytic solutions of the dustybox problem and ii) solutions of the dustywave, dustyshock, dustysedov and dustydisc obtained with explicit timestepping. We find that the implicit method is 1- 10 times faster than the explicit temporal integration when the ratio r between the the timestep and the drag stopping time is 1 < r < 1000.Comment: Accepted for publication in MNRA

An axis-free overset grid in spherical polar coordinates for simulating 3D self-gravitating flows

A type of overlapping grid in spherical coordinates called the Yin-Yang grid is successfully implemented into a 3D version of the explicit Eulerian grid-based code PROMETHEUS including self-gravity. The modified code successfully passed several standard hydrodynamic tests producing results which are in very good agreement with analytic solutions. Moreover, the solutions obtained with the Yin-Yang grid exhibit no peculiar behaviour at the boundary between the two grid patches. The code has also been successfully used to model astrophysically relevant situations, namely equilibrium polytropes, a Taylor-Sedov explosion, and Rayleigh-Taylor instabilities. According to our results, the usage of the Yin-Yang grid greatly enhances the suitability and efficiency of 3D explicit Eulerian codes based on spherical polar coordinates for astrophysical flows.Comment: 15 pages, 17 figures, 2 tables, accepted for publication in A&

Functional properties of roselle (Hibiscus sabdariffa L.) seed and its application as bakery product

Roselle (Hibiscus sabdariffa L.) seed is a valuable food resource as it has an excellent source of dietary fibre. Therefore, this study examined the functional properties of roselle seeds. Replacement of cookie flour with roselle seed powder at levels of 0–30 % was investigated for its effect on functional and nutritional properties of cookies. Among the four formulations cookies, the most preferred by panelists was 20 % roselle seed powder cookie (F3), followed by 10 % roselle seed powder cookie (F2) and 30 % roselle seed powder cookie (F4). The least preferred formulation among all was control cookie (F1). Cookie with 20 % roselle seed powder added showed higher content of total dietary fibre (5.6 g/100 g) as compared with control cookie (0.90 g/100 g). Besides that, cookies incorporated with roselle seed powder exhibited improved antioxidant properties. Thus, roselle seed powder can be used as a dietary fibre source and developed as a functional ingredient in food products

Pion Interferometry for a Granular Source of Quark-Gluon Plasma Droplets

We examine the two-pion interferometry for a granular source of quark-gluon plasma droplets. The evolution of the droplets is described by relativistic hydrodynamics with an equation of state suggested by lattice gauge results. Pions are assumed to be emitted thermally from the droplets at the freeze-out configuration characterized by a freeze-out temperature $T_f$. We find that the HBT radius $R_{out}$ decreases if the initial size of the droplets decreases. On the other hand, $R_{side}$ depends on the droplet spatial distribution and is relatively independent of the droplet size. It increases with an increase in the width of the spatial distribution and the collective-expansion velocity of the droplets. As a result, the value of $R_{out}$ can lie close to $R_{side}$ for a granular quark-gluon plasma source. The granular model of the emitting source may provide an explanation to the RHIC HBT puzzle and may lead to a new insight into the dynamics of the quark-gluon plasma phase transition.Comment: 5 pages, 4 figure

Inviscid SPH

In smooth-particle hydrodynamics (SPH), artificial viscosity is necessary for the correct treatment of shocks, but often generates unwanted dissipation away from shocks. We present a novel method of controlling the amount of artificial viscosity, which uses the total time derivative of the velocity divergence as shock indicator and aims at completely eliminating viscosity away from shocks. We subject the new scheme to numerous tests and find that the method works at least as well as any previous technique in the strong-shock regime, but becomes virtually inviscid away from shocks, while still maintaining particle order. In particular sound waves or oscillations of gas spheres are hardly damped over many periods.Comment: 14 pages (15 in arXiv), 15 figures, accepted for publication in MNRA