New information on the distribution pattern of Acanthobdella peledina (Annelida, Acanthobdellida) in Eastern Siberia

Zootaxa ◽  
2018 ◽  
Vol 4399 (1) ◽  
pp. 123
Author(s):  
IRINA A. KAYGORODOVA ◽  
ELENA V. DZYUBA
Keyword(s):  
Distribution Pattern ◽  
Eastern Siberia ◽  
Lateral Nerve ◽  
Coelomic Cavity ◽  
New Information ◽  
Scientific World ◽  
Parasitic Lifestyle ◽  
Anterior Segments ◽  
Nerve System ◽  
Intermediate Role

The Acanthobdellida is a group of annelid parasites of fish, which are restricted to subarctic parts of the Northern Hemisphere. These ancient worms arouse the interest of the scientific world due to their mosaic combination of (1) primitive oligochaetous characters (e.g. the presence of setae on the very anterior segments, a lateral nerve system and a metameric coelomic cavity around the intestinal canal) and (2) evolutionarily advanced hirudinean ecological and morphological features (e.g. suckers and parasitic lifestyle), attesting to their intermediate role between Oligochaeta and Euhirudinea (i.e. leeches with setae). 

scholarly journals Endemic bats (Mammalia: Chiroptera) of Colombia: State of knowledge, distribution, and conservation

2020 ◽  
Vol 25 (1) ◽  
pp. 55-94 ◽  
Author(s):  
Héctor E. Ramírez-Chaves ◽  
Elkin A. Noguera-Urbano ◽  
Darwin M. Morales-Martínez ◽  
Danny Zurc ◽  
Andrés Felipe Vargas-Arboleda ◽  
...  
Keyword(s):  
Distribution Pattern ◽  
Endemic Species ◽  
National Level ◽  
Taxonomic Status ◽  
Original Description ◽  
Type Locality ◽  
International Union ◽  
New Information ◽  
Available Information ◽  
Bat Diversity

Colombia, with 209 species, is one of the richest countries in terms of bat diversity. This high bat diversity is comprised in nine families and 72 genera. A total of eight species of the families Emballonuridae (n = 1) and Phyllostomidae (n = 7) are listed as endemic to the country. In spite the relevance of Colombiain bat diversity, little is known of these endemic species which are mostly known from the type locality (n=4), whereas for others (n = 2), their taxonomic status is uncertain. Here, available information of endemic bats from Colombia is compiled, and new information on their distribution and conservation is provided. The most included species in publications including the original description (n = 15) was Lonchorhina marinkellei. The only distribution pattern observed for the species evaluated was for Carollia monohernandezi and Vampyressa sinchi that might overlap distributions in the eastern slopes of the Eastern Cordillera. Most endemic species are from the Andean and inter-Andean regions of the country (n = 6). At national level, there are no endemic species in any threatened category; however, at least one species (Lonchorhina marinkellei) is considered as Vulnerable (VU) and one (Saccopteryx antioquensis) as Endangered (EN) by the International Union forConservation of Nature-IUCN.

Neuro-Muscular Mechanisms of Abdominal Pumping in the Locust

1973 ◽  
Vol 59 (1) ◽  
pp. 149-168
Author(s):  
G. W. LEWIS ◽  
P. L. MILLER ◽  
P. S. MILLS
Keyword(s):  
Schistocerca Gregaria ◽  
Longitudinal Ventilation ◽  
Inspiratory Muscles ◽  
Metathoracic Ganglion ◽  
Inspiratory Motor ◽  
Motor Neurones ◽  
Motor Nerves ◽  
Expiratory Muscles ◽  
Anterior Segments ◽  
Nerve System

1. The muscles involved in dorso-ventral and longitudinal ventilation in the pregenital segments of Schistocerca gregaria are described. Expiratory muscles are shown to be innervated by paired lateral nerves whereas the dorso-ventral inspiratory muscles are innervated by the unpaired median nerve system. 2. Normal pumping activity is brought about by alternating bursts of impulses in expiratory and inspiratory motor nerves. Inspiratory bursts are relatively invariant, whereas expiratory bursts show a positive correlation with ventilatory cycle length. The firing patterns of some units within the bursts are described. 3. In general anterior segments fire motor bursts earlier than posterior segments during well synchronized active ventilation, the metathoracic ganglion firing first. However, much variation is seen both within one locust and between different locusts. Burst-formation continues in isolated nerve cords. 4. Activity, phase-locked with expiration, has been recorded in the connectives. The evidence suggests that it occurs in a pair of co-ordinating interneurones which run from the metathoracic ganglion to the last abdominal ganglion and determine the initiation, duration and possibly the intensity of the expiratory motor bursts in each segment. A second parallel system may co-ordinate activity when the metathoracic co-ordinating interneurones are inactive. Inspiratory motor neurones are probably autoactive and the duration of their firing may normally be determined by the discharge phase of a metathoracic oscillator which acts by inhibiting the co-ordinating interneurones.

Lattice Imaging of Twin, Lath and α/Martensite Boundaries in Duplex Low Carbon Steels

1977 ◽  
Vol 35 ◽  
pp. 118-119
Author(s):  
J. Y. Koo ◽  
G. Thomas
Keyword(s):  
High Resolution Electron Microscopy ◽  
Ferrite Matrix ◽  
Carbon Steels ◽  
Bright Field Image ◽  
Low Carbon ◽  
Lattice Imaging ◽  
Bright Field ◽  
Lattice Image ◽  
New Information ◽  
Resolution Electron

High resolution electron microscopy has been shown to give new information on defects(1) and phase transformations in solids (2,3). In a continuing program of lattice fringe imaging of alloys, we have applied this technique to the martensitic transformation in steels in order to characterize the atomic environments near twin, lath and αmartensite boundaries. This paper describes current progress in this program.Figures A and B show lattice image and conventional bright field image of the same area of a duplex Fe/2Si/0.1C steel described elsewhere(4). The microstructure consists of internally twinned martensite (M) embedded in a ferrite matrix (F). Use of the 2-beam tilted illumination technique incorporating a twin reflection produced {110} fringes across the microtwins.

Stereo Electron Microscopy Applied to High Resolution Freeze-Etch Replicas

1970 ◽  
Vol 28 ◽  
pp. 306-307
Author(s):  
L. Andrew Staehelin
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
High Resolution ◽  
Smooth Surfaces ◽  
Small Particles ◽  
Membrane Surfaces ◽  
Wide Acceptance ◽  
New Information ◽  
Number Of Particles ◽  
Small Holes

Freeze-etched membranes usually appear as relatively smooth surfaces covered with numerous small particles and a few small holes (Fig. 1). In 1966 Branton (1“) suggested that these surfaces represent split inner mem¬brane faces and not true external membrane surfaces. His theory has now gained wide acceptance partly due to new information obtained from double replicas of freeze-cleaved specimens (2,3) and from freeze-etch experi¬ments with surface labeled membranes (4). While theses studies have fur¬ther substantiated the basic idea of membrane splitting and have shown clearly which membrane faces are complementary to each other, they have left the question open, why the replicated membrane faces usually exhibit con¬siderably fewer holes than particles. According to Branton's theory the number of holes should on the average equal the number of particles. The absence of these holes can be explained in either of two ways: a) it is possible that no holes are formed during the cleaving process e.g. due to plastic deformation (5); b) holes may arise during the cleaving process but remain undetected because of inadequate replication and microscope techniques.

Trial production of γ-type energy filtering TEM

1995 ◽  
Vol 53 ◽  
pp. 604-605
Author(s):  
Y. Taniguchi ◽  
E. Nakazawa ◽  
S. Taya
Keyword(s):  
Magnetic Energy ◽  
Electron Optics ◽  
Electron Microscopic ◽  
Mass Spectrometers ◽  
Ion Optics ◽  
Energy Filtering ◽  
New Information ◽  
New Type ◽  
Fringing Fields

Imaging energy filters can add new information to electron microscopic images with respect to energy-axis, so-called electron spectroscopic imaging (ESI). Recently, many good results have been reported using this imaging technique. ESI also allows high-contrast observation of unstained biological samples, becoming a trend of the field of morphology. We manufactured a new type of energy filter as a trial production. This energy filter consists of two magnets, and we call γ-filter since the trajectory of electrons shows ‘γ’-shape inside the filter. We evaluated the new energyγ-filter TEM with the γ-filter.Figure 1 shows schematic view of the electron optics of the γ-type energy filter. For the determination of the electron-optics of the γ-type energy filter, we used the TRIO (Third Order Ion Optics) program which has been developed for the design of high resolution mass spectrometers. The TRIO takes the extended fringing fields (EFF) into consideration. EFF makes it difficult to design magnetic energy filters with magnetic sector fields.

Principles of Low-Vacuum SEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1304-1305
Author(s):  
Klaus-Ruediger Peters
Keyword(s):  
New Technologies ◽  
High Vacuum ◽  
Optical Microscope ◽  
Specimen Surface ◽  
Electrical Field ◽  
Gaseous Environment ◽  
New Information ◽  
Gas Molecules ◽  
New Interactions ◽  
Gas Pressures

Only recently it became possible to expand scanning electron microscopy to low vacuum and atmospheric pressure through the introduction of several new technologies. In principle, only the specimen is provided with a controlled gaseous environment while the optical microscope column is kept at high vacuum. In the specimen chamber, the gas can generate new interactions with i) the probe electrons, ii) the specimen surface, and iii) the specimen-specific signal electrons. The results of these interactions yield new information about specimen surfaces not accessible to conventional high vacuum SEM. Several microscope types are available differing from each other by the maximum available gas pressure and the types of signals which can be used for investigation of specimen properties.Electrical non-conductors can be easily imaged despite charge accumulations at and beneath their surface. At high gas pressures between 10-2 and 2 torr, gas molecules are ionized in the electrical field between the specimen surface and the surrounding microscope parts through signal electrons and, to a certain extent, probe electrons. The gas provides a stable ion flux for a surface charge equalization if sufficient gas ions are provided.

Modern TEM systems architecture

1986 ◽  
Vol 44 ◽  
pp. 602-605
Author(s):  
U. Gross ◽  
P. Hagemann
Keyword(s):  
Electron Microscope ◽  
Information Gathering ◽  
Systems Architecture ◽  
Control Functions ◽  
Transmission Electron ◽  
New Information ◽  
Comprehensive Information ◽  
Scanning Transmission ◽  
Diffraction Patterns ◽  
Analytical Equipment

By addition of analytical equipment, scanning transmission accessories and data processing equipment the basic transmission electron microscope (TEM) has evolved into a comprehensive information gathering system. This extension has led to increased complexity of the instrument as compared with the straightforward imaging microscope, since in general new information capacity has required the addition of new control hardware. The increased operational complexity is reflected in a proliferation of knobs and buttons.In the conventional electron microscope design the operating panel of the instrument has distinct control elements to alter optical conditions of the microscope column in different modes. As a consequence a multiplicity of control functions has been inevitable. Examples of this are the three pairs of focus and magnification controls needed for TEM imaging, diffraction patterns, and STEM images.

X-ray microprobe for materials science

1994 ◽  
Vol 52 ◽  
pp. 56-57
Author(s):  
G.E. Ice
Keyword(s):  
Crystallographic Orientation ◽  
Local Structure ◽  
Materials Science ◽  
Chemical Information ◽  
X Ray Diffraction ◽  
Ray Optics ◽  
X Ray ◽  
Novel Materials ◽  
New Information ◽  
Elemental Sensitivity

The increasing availability of synchrotron x-ray sources has stimulated the development of advanced hard x-ray (E≥5 keV) microprobes. With new x-ray optics these microprobes can achieve micron and submicron spatial resolutions. The inherent elemental and crystallographic sensitivity of an x-ray microprobe and its inherently nondestructive and penetrating nature will have important applications to materials science. For example, x-ray fluorescent microanalysis of materials can reveal elemental distributions with greater sensitivity than alternative nondestructive probes. In materials, segregation and nonuniform distributions are the rule rather than the exception. Common interfaces to whichsegregation occurs are surfaces, grain and precipitate boundaries, dislocations, and surfaces formed by defects such as vacancy and interstitial configurations. In addition to chemical information, an x-ray diffraction microprobe can reveal the local structure of a material by detecting its phase, crystallographic orientation and strain.Demonstration experiments have already exploited the penetrating nature of an x-ray microprobe and its inherent elemental sensitivity to provide new information about elemental distributions in novel materials.

Central Nerve System Impairment, AMA Guides, Sixth Edition: An Overview

2018 ◽  
Vol 23 (1) ◽  
pp. 10-13
Author(s):  
James B. Talmage ◽  
Jay Blaisdell
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Neurological Impairment ◽  
Sixth Edition ◽  
Central Nerve System ◽  
The Central Nervous System ◽  
The One ◽  
Nerve System ◽  
The Brain

Abstract Injuries that affect the central nervous system (CNS) can be catastrophic because they involve the brain or spinal cord, and determining the underlying clinical cause of impairment is essential in using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), in part because the AMA Guides addresses neurological impairment in several chapters. Unlike the musculoskeletal chapters, Chapter 13, The Central and Peripheral Nervous System, does not use grades, grade modifiers, and a net adjustment formula; rather the chapter uses an approach that is similar to that in prior editions of the AMA Guides. The following steps can be used to perform a CNS rating: 1) evaluate all four major categories of cerebral impairment, and choose the one that is most severe; 2) rate the single most severe cerebral impairment of the four major categories; 3) rate all other impairments that are due to neurogenic problems; and 4) combine the rating of the single most severe category of cerebral impairment with the ratings of all other impairments. Because some neurological dysfunctions are rated elsewhere in the AMA Guides, Sixth Edition, the evaluator may consult Table 13-1 to verify the appropriate chapter to use.

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