Permanent slides for morphological studies of small crustaceans: Serban\u27s method and its variation applied on Bathynellacea (Malacostraca)

Morphological studies of small invertebrates often involve the preparation of slides to observe minute body parts under a compound microscope. Preparation should facilitate observation, through traditional optical microscopy, of small surface structures on different planes, like pores, spines and setae. Various methods and techniques, using different mounting media that specialists have adopted to observe and preserve small crustaceans, have their advantages and disadvantages.Within the order Bathynellacea, specimens in the family Bathynellidae are particularly challenging due to their small size (0.5 to 2.25 mm body length) and very delicate exoskeleton, which tends to be completely digested when using common clearing mounting media, making future consultations impossible. Permanent slides are fundamental to preserve small specimens for scientific collections, because temporary slide preparations can easily result in the loss of body parts in the passage between slide and vial and vice versa. Dr Eugene Serban worked on Bathynellacea for more than 40 years, improving the preparation and preservation of delicate specimens using a stained glycerol-jelly and double cover slip mounting technique. His method is described here with a variation that speeds up the original procedure and was implemented in most recent years by one of the authors (A.I.C.). The technique provides excellent preservation and visualization of body parts on permanent slides, which do not need curation tasks and can last for many years. © 2016 Koninklijke Brill NV, Leide

A Modified Cell for Measurements of Dielectric Constant

Several different cells for measurements of dielectric constant are described in the literature. In particular a glass cell with mirror walls, suitable only for some particular solvents, has been described fully

Understanding subterranean variability: the first genus of Bathynellidae (Bathynellacea, Crustacea) from Western Australia described through a morphological and multigene approach

The number of subterranean taxa discovered in the north of Western Australia has substantially increased due to the requirements for environmental surveys related to mining development. Challenges in estimating subterranean biodiversity and distributions are related to lack of knowledge of taxa with convergent morphological characters in a largely unobservable ecosystem setting. An integrated approach is warranted to understand such complexity. Bathynellidae occur in most Australian aquifers, but only one species has been described so far, and the group lacks a reliable taxonomic framework. A new genus and one new species from the Pilbara region of Western Australia, Pilbaranella ethelensis, gen. et sp. nov., is described using both morphological and molecular data. Three additional species of Pilbaranella are defined through mitochondrial and nuclear genes, using Automatic Barcode Gap Discovery and Poisson Tree Processes species delimitation methods. A comparison of morphology and 18S rRNA sequences between Pilbaranella, gen. nov. and known lineages provides the evidentiary basis for the decision to establish a new genus. This study provides a morphological and molecular framework to work with Bathynellidae, especially in Australia where a highly diverse fauna remains still undescribed

The role of allopatric speciation and ancient origins of Bathynellidae (Crustacea) in the Pilbara (Western Australia): Two new genera from the De Grey River catchment

The stygofaunal family of Bathynellidae, is an excellent group to study the processes that shape diversity and distribution, since they have unknown surface or marine relatives, high level of endemism, and limited dispersal abilities. Recent research on Bathynellidae in Western Australia (Pilbara) has uncovered new taxa with unexpected distributions and phylogenetic relationships, but the biogeographical processes that drive their diversification on the continent are still unclear. By exploring the diversity, distribution, and divergence time of Bathynellidae in a setting such as the perched and isolated aquifers of the Cleaverville Formation in the north of the De Grey River catchment (Pilbara), we aim to test the hypothesis that vicariance has shaped the distribution of this family, specifically if one or multiple vicariant events were involved. We analysed the specimens collected from perched water in different plateaus of the Cleaverville Formation, combining morphological and molecular data from mitochondrial and nuclear genes. We described two new species and genera (Anguillanella callawaensis gen. et sp. nov. and Muccanella cundalinensis gen. et sp. nov.), and two additional taxa are recognised using morphology and/or Automatic Barcode Gap Discovery and Poisson Tree Processes species delimitation methods. New genera and species result restricted to isolate perched aquifers on single plateaus and their distributions, phylogenetic relationships, and divergence time estimates support multiple vicariant events and ancient allopatric speciation

Ekstraksi Pektin dari Berbagai Macam Kulit Jeruk

Tanaman jeruk merupakan tanaman asli Indonesia dan hampir seluruh wilayah Indonesia dapat ditanami jeruk. Buah jeruk dapat dikonsumsi dalam bentuk buah segar ataupun hasil olahan. Limbah dari buah jeruk yang berupa kulit jeruk selain dapat dibuat manisan, juga dapat diekstrak pektinnya. Jeruk mempunyai kandungan pektin yang cukup tinggi, sekitar 30%. Pektin juga terdapat pada buah–buah lainnya seperti pisang, apel dan papaya. Pektin merupakan bahan aditif yang memiliki aplikasi luas pada industri makanan karena kemampuannya membentuk gel seperti untuk membuat jelly, se lai, desert dan sebagai penghalus tekstur. Selain itu, pektin juga dapat digunakan dalam bidang bakery fillings, yaitu pada penyiapan buah. Dalam bidang produksi susu, digunakan pada pengasaman susu dan minuman berprotein serta yogurt. Pektin dapat juga digunakan dalam bidang produk kesehatan dan farmasi. Penelitian ini bertujuan untuk mengetahui perbandingan pelarut dan zat terlarut yang diperlukan untuk mendapatkan yield pektin dengan jumlah yang maksimum. Dari hasil penelitian disimpulkan bahwa yield pektin meningkat seiring dengan kenaik an kecepatan pengadukan dan besarnya perbandingan berat kulit jeruk:volume pelarut. Semua kulit jeruk termasuk kedalam golongan high metoksil pektin. Kadar metoksil dan kekuatan pembentukan gel Jeruk manis> Jeruk Lokam> Jeruk Shantang> Jeruk Nipis. Kadar abu pektin dari berbagai macam kulit jeruk memenuhi standar mutu kering pektin

The young stellar population at the center of NGC 205

Context. NGC 205 is a peculiar dwarf elliptical galaxy hosting in its center a population of young blue stars. Their origin is still matter of debate, the central fresh star formation activity possibly being related to dynamical interactions between NGC 205 and M31. Aims. The star formation history in the central 30\arcsec ($\sim$120 pc) around the NGC 205 central nucleus is investigated in order to obtain clues to the origin of the young stellar population. Methods. Deep HST/ACS CCD photometry is compared with theoretical isochrones and luminosity functions to characterize the stellar content of the region under study and compute the recent SF rate. Results. Our photometry reveals a previously undetected blue plume of young stars clearly distinguishable down to I$\simeq$26. Our analysis suggests that 1.9$\times10^5$ M$_\odot$ were produced between approximately 62 Myr and 335 Myr ago in the NGC 205 inner regions, with a latest minor episode occurring $\sim$25 Myr ago. This implies a star formation rate of $\sim7\times10^{-4}$ M$_\odot$/yr over this period. Conclusions. The excellent fit of the observed luminosity function of young main sequence stars obtained with a model having a constant star formation rate argues against a tidally triggered star formation activity over the last $\sim$300 Myr. Rather, a constant SF may be consistent with NGC 205 being on its first interaction with M 31.Comment: 5 pages, 2 figures, accepted for publication in A&A letter

Studies on Covalent Adducts of Dehydrouric Acid

The structure of 5-chloro and 5-alkoxy-5,7-dihydro-3//-purine-2,4,6-trio- nes (6 and 7-9) has been corroborated by their spectral properties and X-ray crystallography. The stereochemical model (fì)-10 of the key uricolytic intermediate was prepared using menthol as chiral auxiliary. In acidic solutions, depending on the N-substitution, the ring cleavage occurred either at the 4,9-bond 6b -» 13 (R1 = Me) or at the 3,4-bond 6c -» 14 (R1 = H). Opening of the 1,6-bond is the dominant process under alkaline conditions. Decarboxylative rearrangement into 1,3-dimethylallantoin (15) was specific for N(7)-unsubstituted derivatives. Evidence for intermediacy of the bicyclol tautomeric form was supplied by isolation of l-menthoxy-2,4-dimethyl-3,7-di- oxo-2,4,6,8-tetraazabicyclo[3.3.0]octane (16); fragmentation of 10 into 5- menthoxy-imidazolidin-2,4-dione (17) also takes place under forcing conditions. Conversely, no allantoin rearrangement was encountered in the R7*H cases; 7d underwent the pyrimidine ring fragmentation to give 5-methoxy-l- methyl-4-methylimino-imidazolidine-2-one (18) or 5-carboxamido-5-methoxy- l-methyl-4-methylimino-imidazolidine-2-one (19). A possible mechanism for these ring transformation reactions is discussed

Generation of squeezed light in a nonlinear asymmetric directional coupler

We show that a nonlinear asymmetric directional coupler composed of a linear waveguide and a nonlinear waveguide operating by nondegenerate parametric amplification is an effective source of single-mode squeezed light. This is has been demonstrated, under certain conditions and for specific modes, for incident coherent beams in terms of the quasiprobability functions, photon-number distribution and phase distribution.Comment: 19 pages, 5 figure

The rise and fall of quantum and classical correlations in open-system dynamics

Interacting quantum systems evolving from an uncorrelated composite initial state generically develop quantum correlations -- entanglement. As a consequence, a local description of interacting quantum system is impossible as a rule. A unitarily evolving (isolated) quantum system generically develops extensive entanglement: the magnitude of the generated entanglement will increase without bounds with the effective Hilbert space dimension of the system. It is conceivable, that coupling of the interacting subsystems to local dephasing environments will restrict the generation of entanglement to such extent, that the evolving composite system may be considered as approximately disentangled. This conjecture is addressed in the context of some common models of a bipartite system with linear and nonlinear interactions and local coupling to dephasing environments. Analytical and numerical results obtained imply that the conjecture is generally false. Open dynamics of the quantum correlations is compared to the corresponding evolution of the classical correlations and a qualitative difference is found.Comment: 35 pages, 10 figures. Revised according to comments of the referees. Accepted for publication in Phys. Rev.