bluuebunny/crossref_metadata_2025 huggingface dataset:
The Nymph of Ephemerella excrucians Walsh
Authors: Leonard Justin W.
Published: January 2010

The taxonomic status of Ephemerella excrucians Walsh was recently discussed by Burks (1947), who also stated that destructive ecological changes have drastically altered the type locality of the species. Special interest attaches, therefore, to two male specimens of Ephemerella which I reared from nymphs taken in the Au Sable River, Crawford County, Michigan, and which Dr. Burks has determined as E. excrucians.
The Influence of Spray Programs on the Fauna of Apple Orchards in Nova Scotia. III. Mites and their Predators
Authors: Lord F. T.
Published: January 2010

Three mirids, Diaphnidia pellucida Uhler, Hyaliodes harti Knight, and Campylomma verbasci (Meyer), are effective predators of the red mite and probably of the clover mite from early in June until the latter part of July. These three species are the only important predacious mirids under the conditions of the present spray practices in Nova Scotia. Gilliatt (2) has given an account of the life-histories of the three specics and discussed their importance in the natural contrnl of the red mite, and his account need not be repeated here. The three mirids are often the only important predacious species in many commercial orchards during the summer months because of the destruction of I. tiliae and H. faurei by the sulphur sprays emploved around the bloom period. Their presence in such orchards is in itself evidence that neither bordeaux mixture nor flotation sulphur reduces their numbers. Observation on a considerable number of occasions showed that iron carbamate has no effect on these mirids. An opportunity to test some of the common spray chemicals on two of the species was presented in the F. Palmer orchard at Berwick in 1947. Two trees were sprayed with each of the materials listed, and the insects were collected as they dropped on two trays, of 32 square feet each, which had been placed beneath the trees.
Distribution of Progeny by Chelonus texanus Cress. (Hymenoptera: Braconidae)
Authors: Ullyett G. C.
Published: January 2010

The efficiency of an entomophagous parasite may be defined as the capacity which it possesses for distributing its eggs among the available host population in such a manner that its progeny have the best possible chance of survival. This capacity is determined by a number of factors which are, as yet, imperfectly understood. Among these factors are the ability of the parasite female to discriminate between hosts which are suitable for the development of her progeny and those which are not; the relative densities of the parasite and host populations; the habits of the host insect; and the behaviour of the parasite itself during oviposition.
The Role of Morphology in Systematics
Authors: Brown W. J.
Published: January 2010

The following notes consider very briefly a very large field. They apply primarily to zoological systematics. They reflect my respect for the thoughtful field naturalist and, probably, some other prejudices. They reflect my inrerest in the species rather than in the higher categories, and are of course influenced by the limitations of my experience.
On a Migration of Tarnetrum corruptum (Hagen) (Odonata) in Western Oregon
Authors: Macy Ralph W.
Published: January 2010

On the warm afternoon of August 29, 1948, as I was walking through a wheat stubble-field on my farm located six miles southwest of McMinnville, Oregon, I became aware that I was in the midst of a dragonfly migration. I could see them all about me for a radius of perhaps seventy-five feet which was about the limit of my vision for an insect of this size. When first seen there was a considerable number passing toward the west with from thirty-five to fifty of the insects visible at any given moment but after about five minutes they began to thin out until only a few were visible. I then walked south for two hundred feet at which place another heavy concentration was encountered. After a short interval these thinned to a few stragglers. Thinking that the migration was about over I retraced my steps only to meet with another wave. It soon became apparent that the migration was taking place orer a wide front and that the insects tended to fly in groups over the valley floor.
Important Advances in Zoological Nomenclature Achieved at the Thirteenth International Congress of Zoology, Paris, July, 1948
Authors: Dymond J. R.
Published: January 2010

During the Thirteenth International Congress of Zoology which closed at Paris on Tuesday, 27th July, the International Commission on Zoological Nomenclature, holding its first meeting since the close of the war, put forward a comprehensive programme for the reform and development of Zoological Nomenclature.

Measures taken to reform procedures are designed to enable the Commission to reach decisions much more rapidly than has been possible in the past.
A Method of Keeping Paradichlorobenzene in Insect Boxes
Authors: Putman Wm. L.
Published: January 2010

Keeping a supply of paradichlorohenezene or naphthalene in insect boxes for protection against dermestids has always been a problem. Small cloth bags or wire screen boxes are frequently used hut are a nuisance to fill and require several pins to hold them in place. The method used for protecting the collections at the Vineland Station Laboratory appears to be more convenient.

Rolls of dental cotton, which are about three-quarters of an inch in diameter, are cut into pieces two inches long and mounted crosswise on ordinary office pins. Paradichlorobenzene is melted (M.P. 53° C.), most conveniently in a can placed in a vessel of hot water, and the pieces of cotton are dipped into it. The cotton becomes saturated almost instantaneously and is laid on a board until the paradichlorobenzene solidifies.
Some Notes on Tabanidae (Diptera) and the Description of Two New Chrysops
Authors: Pechuman L. L.
Published: January 2010

The excellent monographic studies of Brennan (1935) and Stone (1938) on Nearctic Tabanidae and the even more recent catalog of Philip (1947) has placed the study of this group on a firm foundation. The student of this family rarely suffers from a dearth of material since the abundance of individuals of many species, their ease of preservation and their economic importance lead to the collection of long series. As these series accumulate, it sometimes is found that certain species exceed the limits of variation conceded that species, and in other cases what appear to be new forms, may be separated.
Laboratory Technique for Testing Codling Moth Insecticides
Authors: Putman Wm. L.
Published: January 2010

In 1944, as soon as DDT became available, laboratory investigation of its possibilities for control of codling moth, Carpocapsa pomonella (L.) was started at Vineland Station. The work was later expanded and the methods improved until the present technique was evolved; this is still unsatisfactory in many respects but is presented to indicate what may be accomplished in a small laboratory with very limited personnel and equipment and at comparatively little cost.
Nutritional Studies with Battella germanica (L.) Reared Under Aseptic Conditions: I. Equipment and Technique
Authors: House Howard L. , Patton Robert L.
Published: January 2010

In biological research it is often desirable to rear and handle animals free from microorganisms. This is particularly true in nutritional studies in which it is generally recognized that certain orgnisms in the digestive tract can supply nutritional factors which might otherwise be lacking in the diet. The possibility of this intervention makes it necessary to devise techniques for rearing and handling insects aseptically, in so far is the fauna and flora of their intestinal tract and of their environment are concerned. Consequently, a technique used throughout the present series of studies was developed making use of specially designed equipment by means of which nymphs of the cockroach, Blattella germanica (L.), were hatched and maintained under aseptic conditions, fed aseptic food, and kept aseptic throughout a series of measurements to evaluate their weight increment. The equipment and methods used constitute the basis of the present paper.
Practical Issues in High‐Speed Cell Sorting
Authors: Arnold Larry W. , Lannigan Joanne
Published: January 2010

Modern flow cytometric cell sorters are all capable of so‐called “high‐speed sorting.” However, there is confusion about exactly how fast a “high‐speed” cell sorter can sort cells. There are many considerations in achieving the fastest sorting speed, as well as the highest quality sort results—cell recovery, purity, and functionality. This requires the same considerations required for “slow‐speed sorting”; however, a more precise implementation is required for high‐speed sorting. The modern cell sorters enable high‐speed sorting because of advances in high‐speed electronics and data processing. We discuss the practical considerations of high‐speed sorting in terms of the theory and practical aspects of the mechanical and software components of sorting, statistics of sorting, cell preparation and viability, instrument setup, sort strategies, and biosafety. Curr. Protoc. Cytom. 51:1.24.1‐1.24.30. © 2010 by John Wiley & Sons, Inc.
Measurement of T Cell Activation After 16‐hr In Vitro Stimulation with Concanavalin A
Authors: Arneth Borros M.
Published: January 2010

A flow cytometry assay that can be used to directly determine the proportion of activated T lymphocytes in human whole blood samples after stimulation with concanavalin A is presented here. Human whole blood is incubated with fluorescently labeled antibodies (against CD3, CD4, CD8, and CD69), erythrocytes are then lysed, and the samples are analyzed using a flow cytometer. The assay presented is able to differentiate between CD4+ and CD8+ T lymphocytes. Thus, it is possible to quantify both lymphocyte populations in parallel, as well as the respective proportions of activated T lymphocytes, all from one sample. An additional advantage of this assay is that it was developed to assay whole blood, thereby reducing the likelihood of introducing pre‐analytic error and facilitating the calculation of quantitative ratios. Thus, the method can be used for both in vitro and ex vivo experiments. Curr. Protoc. Cytom. 51:6.28.1‐6.28.10. © 2010 by John Wiley & Sons, Inc.
Stem Cell Side Population Analysis and Sorting Using DyeCycle Violet
Authors: Telford William G.
Published: January 2010

Hoechst side population (SP) analysis has proven to be a valuable technique for identifying and sorting stem and early progenitor cells in a variety of tissues and species. In this method, the DNA binding dye Hoechst 33342 is loaded into the cell population of interest; stem cells preferentially exclude this dye, and these low‐fluorescence cells can be detected by flow cytometry. However, Hoechst SP analysis usually requires a flow cytometer equipped with an ultraviolet laser source for optimal performance. Unfortunately, ultraviolet lasers are expensive and are not common fixtures on flow cytometers. Violet laser diodes emitting in the 395‐ to 410‐nm range are less expensive and have become much more common on flow cytometers, but do not provide optimal excitation of Hoechst 33342. DyeCycle Violet is a cell‐permeable DNA binding dye with a chemical structure similar to Hoechst 33342, but with a longer excitation maximum. DyeCycle Violet can be substituted for Hoechst 33342 when performing side population analysis on a cytometer with a violet laser source. The procedure for DyeCycle Violet labeling for side population is described, as well as the limitations particular to this dye. Curr. Protoc. Cytom. 51:9.30.1‐9.30.9. © 2010 by John Wiley & Sons, Inc.
Measurement of Phagocytosis and of the Phagosomal Environment in Polymorphonuclear Phagocytes by Flow Cytometry
Authors: Simons Elizabeth R.
Published: January 2010

Phagocytes are the most important early components of the immune response, programmed to recognize, engulf, and destroy immune complexes (formed when antibodies recognize their specific antigens), foreign particles, bacteria, mycobacteria, apoptotic cells, etc. Neutrophils, monocytes, macrophages, and dendritic cells all participate in this process. Flow cytometry permits observation of phagocytes that have responded and, with the appropriate fluorescent probes, of the environment in the phagosome that has enclosed the foreign matter. This unit gives the background and the protocols for performing such studies. Curr. Protoc. Cytom. 51:9.31.1‐9.31.10. © 2010 by John Wiley & Sons, Inc.
Gametogenesis
Authors: Guan Yuefeng , Boavida Leonor , McCormick Sheila
Published: January 2010

Gametogenesis is the process of gamete formation, which includes micro‐ and megagametogenesis. Gametogenesis initiates after specialized cells in the sporophyte undergo meiosis, and subsequent mitotic divisions yield the gametophytic phase of the plant life cycle. In higher plants, microgametogenesis occurs in the anther, producing tricellular pollen with two sperm cells within a vegetative cell. Megagametogenesis occurs in the ovule, producing an embryo sac. The male gametes, the two sperm cells, and the female gametes, the egg and central cell, fuse to yield the zygote and the endosperm, respectively. Both micro‐ and megagametogenesis are under strict genetic control. Studies of gametophytic mutants have identified genes important for gametogenesis. Furthermore, high‐throughput expression profiling techniques have helped identify gene regulatory networks that operate during gametogenesis.

Key concepts:

Plant life cycles alternate between sporophyte and gametophyte generations.

Meiosis produces spores which then undergo gametogenesis.

Higher plants produce two types of gametes, sperm cells in microgametophytes and egg cell and central cell in megagametophytes.

The male and female gametes fuse and give rise to the zygote and to the endosperm.

Identification of gametophytic mutants showed that gametogenesis is under strict genetic control.

Expression profiling studies provided further insight into the gene regulation of gametogenesis and identified new gametophytic genes.
Gametophyte and Sporophyte
Authors: Boavida Leonor C , McCormick Sheila
Published: January 2010

All land plants are believed to have had their origin in a unicellular green algal ancestor. The major innovations in the evolution of early land plants from their primitive ancestors were, not surprisingly, adaptations that allowed plants to reproduce in the absence of water. Besides a more sophisticated and differentiated multicellular anatomy, the invention of new reproductive structures and strategies were fundamental for the success of terrestrial colonization. One of the key innovations in the life history of land plants was the emergence of a haplo‐diplontic life cycle, in which an asexual diploid phase, the sporophyte, is predominant over a reduced and dependent sexual haploid phase, the gametophyte. Other evolutionary trends include a transition to a heterosporic life cycle, internalization of gametes within specialized gametophytes, development of a pollination mechanism independent of water for fertilization, and the invention of seeds, an efficient way of protecting and dispersing the developing embryos.

Key Concepts:

Paleobotany and phylogenetic analyses are important tools for inferring trends in the evolution and diversification of plants.

Land plant evolution involved innovations which allowed organisms to reproduce without a need for water.

Sporophytes are believed to have evolved from a haploid ancestral condition in which meiosis was delayed.

Multicellularity and sexual reproduction allowed diversification and adaptation to new environments during evolution.

Meiosis is essential in a sexually reproducing organism for maintenance of ploidy after fertilization.

Fertilization generates genetic diversity by combining chromosomes inherited from two distinct individuals.

Endospory evolved in the production of a seed.

Heteromorphism allowed evolution of sexual dimorphism.

Apomixis allows clonal propagation by seeds.
Liposomes
Authors: Gregoriadis Gregory , Perrie Yvonne
Published: January 2010

Liposomes are synthetic vesicles consisting of one or more phospholipid bilayers, able to accommodate water‐ and lipid‐soluble molecules. They are used as a delivery system for drugs, genes and vaccines in therapeutics. Liposomes may be formulated with a range of characteristics including different size, charge and drug retention, which can be tailored for a given drug and target site. There is a range of clinical products approved for use which exploit liposomes to passively target drugs or vaccines to the appropriate site of action thereby improving specificity and reducing toxicity. Liposomes can also be actively targeted to specific cells or subcellular regions using targeting ligands attached to their surface, or by modification of the bilayer to give triggered release under appropriate conditions.

Key concepts:

Liposomes are bilayer constructs formed when amphiphiles are exposed to water.

Liposomes can be formulated in different sizes, with different bilayer melting points and with different surface charges allowing for optimization to suit a given drug and target site.

The lipid head‐group dictates the surface charge of the liposomes and the acyl tail influences the melting point of the lipid bilayer and its permeability and therefore influences the drug release rates from liposomes.

The presence of cholesterol within the bilayers can reduce their permeability and drug leakage.

In commercial products, phosphatidylcholines in combination with cholesterol are commonly used to formulate the liposomes.

Drugs can be loaded within the aqueous compartment of the liposomes or within the lipophilic region of the bilayers depending on the lipophilicity of the drug. Through electrostatic interactions, molecules can also be adsorbed on the surface of liposomes.

Currently, liposomes are used for the delivery of drugs, for example cancer chemotherapy, systemic fungal infections and vaccines.

Cationic liposomes are being investigated as potential delivery systems for a range of nucleic acid therapies and for subunit vaccines.
Small‐angle Scattering of Neutrons and X‐rays
Authors: Chow John YH , Trewhella Jill
Published: January 2010

Small‐angle scattering of X‐rays and neutrons is used to study the structures of biological macromolecules in solution. Where the components of biomolecular complexes have different scattering densities, scattering data provide structural information on the individual components and their relative dispositions. One can therefore gain insights into protein–protein and protein–
deoxyribonucleic acid
(DNA) or ribonucleic acid (RNA) interactions within functional complexes. Although scattering data are inherently low resolution and limited in information content due to the random orientations of the scattering molecules, recent applications that use data from complementary methods have facilitated the interpretation of scattering data in terms of detailed models. Advances in computational methods and user interfaces have enabled nonspecialists to use the technique to advance our understanding of biomolecular systems. The increasing availability of synchrotron facilities has also enabled advances in studies of time‐dependent changes in protein structure and the development of high‐throughput approaches.

Key concepts:

Small‐angle scattering provides information on the shapes of biological macromolecules in solution.

Neutron contrast variation reveals the structures and disposition of the components within biomolecular complexes and assemblies.

Proteins and polynucleotides naturally have different scattering densities for X‐rays and neutrons and can therefore be distinguished in a scattering experiment.

Protein deuteration combined with systematic variation in solvent detueration can provide enhanced contrast variation capability for protein complexes.

Small‐angle solution scattering data complements the higher resolution structural data from crystallography and NMR.

Small‐angle scattering improves solution structure determination by providing information on long‐range distances that complements the predominantly short‐range distance information obtained by NMR.

Solution scattering data complements high‐resolution crystallography by providing insights into conformational dynamics that are observed as a result of ligand binding or other changes in biological state.

Synchrotron X‐ray sources enable time‐resolved solution scattering experiments to probe conformational dynamics in proteins and DNA or RNA.

Structural characterization by small‐angle scattering requires highly pure, monodisperse identical particles in solution.
Nuclear Receptor Genes: Evolution
Authors: Sáez Pablo J , Lange Soledad , Pérez‐Acle Tomas , Owen Gareth I
Published: January 2010

Nuclear receptor superfamily members are metazoan innovations which are present in all living metazoan phyla. These genes, presumably originating from a common ancestor in an extinct phylum that predates the sponge (Porifera), has evolved, and is still evolving, to mediate nearly every facet of metazoan life. Representatives of all six classical nuclear receptor superfamily members were present before the protostome–deuterostome split, more than 700 million years ago. Nuclear receptor sequence and structure diversification to accommodate ligand binding has occurred numerous times, with the earliest report of steroid‐hormone binding occurring in the Annelid and of retinoic acid in the lower metazoan phylum Cnidaria. During the Cambrian period a quadruplication of the genome leading to jawed vertebrates gave rise to many of the nuclear receptor paralogues present today.

Key Concepts:

The evolutionary origins and diversification of the nuclear receptor superfamily gene structure in the Metazoa.

Nuclear receptors are unique to the metazoan kingdom.

Members of the nuclear receptor superfamily are present in all extant phyla of metazoans.

Representatives of six classical nuclear receptor superfamily members were present before the proteosome–deutrosome division more than 700 million years ago.

During the Cambrian period a quadruplication of the genome giving rise to jawed vertebrates occurred producing many of the nuclear receptor paralogues present today.
Avirulence Genes
Authors: Rouxel Thierry , Balesdent Marie‐Hélène
Published: January 2010

In gene‐for‐gene systems, resistance of a plant to a pathogen is due to the ‘recognition’ by plant surveillance system (i.e. plant resistance gene product) of a pathogen avirulence determinant encoded by an avirulence gene to eventually result in triggering of plant immunity. Avirulence proteins (or products) actually are effectors involved in pathogenicity. In viruses, virtually all the proteins can behave as avirulence determinants. In all other cases, avirulence genes are extremely diverse, being often species or isolate/strain‐specific and rarely have matches in sequence databases. They often are specifically expressed or strongly over‐expressed during plant–pathogen interaction and the encoded proteins show the presence of secretion signals and translocation signals (e.g. the Type III secretion signal for bacteria). Avirulence genes seem to be submitted to high‐speed diversifying selection allowing the pathogen to diversify its effector repertoire and rapidly escape recognition by the plant resistance gene.

Key concepts

Effectors
of plant pathogens are pathogen molecules that manipulate host cell structure and function thereby facilitating infection.

Effectors often contribute quantitatively to pathogen aggressiveness and are dispensable for the pathogen life cycle.

In the course of plant–pathogen co‐evolution, plants have evolved receptors that detect pathogen effectors (or the effect of the effectors on a plant target) and activate defence responses.

The effectors specifically recognized by ‘matching’ resistance proteins (termed R proteins) are termed
avirulence (AVR) proteins
.

This forms the basis of the
gene‐for‐gene
concept, genetically demonstrated by Flor between 1942 and 1955 and stating that plants producing a specific
R
gene product are resistant towards a pathogen that produces the corresponding
Avr
gene product whereas whenever one of the genes or both are lacking the plant is susceptible and disease ensues.

In wild plant and pathogen populations, avirulence and resistance are discontinuous traits, only present in part of the population. Thus resistance will be applied against only part of the pathogen population (harbouring the corresponding Avr allele) and pathogen will only be avirulent towards part of the plant population (harbouring the matching resistance gene).

All plant pathogens from viruses to nematodes, but also some pests like aphids produce avirulence proteins.

When submitted to resistant populations of plants, pathogens can alter or delete their avirulence proteins to avoid defence elicitation, at risk of a
fitness cost
associated with loss‐of‐function of those effectors.
Calcium Imaging in Neuroscience
Authors: Neubauer Florian B , MacLean Jason N
Published: January 2010

Calcium imaging uses fluorescent indicator molecules to monitor changes of intracellular free calcium concentrations. Calcium imaging is employed to examine electrically excitable tissues such as muscle and neuronal tissue (including glia) where membrane‐related electrical activity is tightly coupled to significant calcium movements into or within cells. In the context of neuroscience research, calcium imaging can be applied at many scales, ranging from a single part of a single neuron to populations of many interconnected neurons. The ability to move between different scales of resolution is a major advantage of calcium imaging, making this technique an important tool for enhancing our understanding of the brain.

Key concepts

Brain researchers use calcium imaging to monitor electrical activity in neurons.

Calcium can be imaged at many scales: from the subcellular to entire brain regions.

Calcium imaging can use different dyes and optical methods.
Molecular Phylogenetic Analyses in Court Trials
Authors: González‐Candelas Fernando
Published: January 2010

Molecular phylogenetics allows reconstructing of the genealogy and evolutionary history of organisms from information on their nucleotide or amino acid sequences. When sequences are derived from very fast evolving organisms, such asribonucleic acid(RNA) viruses, changes accumulate in a few days or weeks, thus allowing the reconstruction of very recent evolutionary events in the history of these populations. One such event is the transmission of one of these viruses, for instancehuman immunodeficiency virus(HIV) orhepatitis C virus(HCV), from an infected person to another. This occasionally results in a legal demand seeking for compensation and/or punishment for the transmitter. Hence, expert testimony is sought in court to determine whether the viruses isolated from the source and the infected patients actually share a common origin or not. Molecular phylogenetics and statistical inference methods are used to translate scientific testimony into expert evaluation of the evidence for the court.

Key concepts:

Fast evolving organisms, such as RNA viruses, can accumulate changes in their genome sequence in a few days or weeks.

Changes in nucleotide sequences can be used to track the evolutionary history of organisms sharing a common ancestor.

The last common ancestor (LCA) of a set of sequences represents the last sequence before the corresponding lineage split in two or more separate lines of descent.

During a transmission event, a portion of the microorganisms in the source is passed onto the recipient(s).

Phylogenetic analysis can be used to ascertain when two or more sequences shared an LCA as well as some of its features.

Sequences derived from a transmission event will share a more recent LCA than those obtained from unrelated sources.

The analysis of LCA can be used to provide expert testimony in courts on the source of an infection.

Under special conditions, it is also possible to ascertain the direction of the transmission and an approximate time for it.

Phylogenetic analysis is a very powerful and reliable methodology whose use for resolving transmission cases has been validated by courts in many countries.
Membrane Insertion of Tail‐anchored Proteins
Authors: Schuldiner Maya , Schwappach Blanche , Weissman Jonathan S
Published: January 2010

Tail‐anchored (TA) proteins are a special class of transmembrane proteins, which harbour only a single hydrophobic segment adjacent to their mostC‐terminus. This anchor must be inserted into membranes posttranslationally to allow for their correct cellular localization. Although TA proteins have essential cellular roles such as signal transduction, apoptosis and vesicle fusion, their biogenesis route has for many years remained unknown. Recently, several advances have created a new understanding of the TA protein insertion machinery. Uncovering the machinery responsible for the biogenesis of TA proteins should further our ability to understand a wide variety of diseases such as forms of cancer caused by activation of the TA protein oncogeneBCL2.

Key concepts:

Tail‐anchored proteins haveC‐terminal hydrophobic domains.

Tail‐anchored proteins are inserted posttranslationally into the membrane.

The GET complex inserts tail‐anchored proteins into the endoplasmic reticulum membrane in yeast.

The TRC complex chaperones tail‐anchored proteins into membranes in humans.
Neuroimaging
Authors: Schweitzer Julie
Published: January 2010

Neuroimaging is the use of techniques to map the location of structural and functional regions within the living brain. It is used extensively in clinical practice to identify abnormalities, such as testing for brain tumors, stroke, and other neurological conditions. It is also increasingly used as a diagnostic tool on a finer scale for metabolic diseases and lesions, including differentiation of neurological disorders (e.g., Alzheimer's Disease versus frontotemporal dementia). Structural neuroimaging techniques generate anatomic images relating to the volume, position, and shape of a structure, whereas functional neuroimaging produces data relating to activities to the active processing of the brain, either in a “resting” state or a response to external stimulus. Functional imaging is also used to assess chemical composition and neuroreceptor characteristics. Structural neuroimaging is more likely to be used clinically, while functional neuroimaging is primarily associated with research endeavors.
Artificial Vision
Authors: Chen S. C. , Hallum L. E. , Wong Y. T. , Dommel N. , Byrnes‐Preston P. J. , Suaning G. J. , Lovell N. H.
Published: January 2010

“Artificial vision” or “prosthetic vision,” in the therapeutic sense, refers to the restoration of some degree of visual perception to the profoundly blind. In nearly all instances, such therapeutic devices are based on electrically exciting the remaining functional neural tissue within the visual pathway, which replaces the intrinsic signals that can no longer be effectively elicited because of the underlying pathology or trauma. The therapeutic device for restoring vision is generally called a “vision prosthesis.”

Although a variety of approaches for a vision prosthesis design are available, a typical system usually would constitute a light sensing component (e.g., a video camera) to replace the photosensitive elements related to light transduction, an image processing unit to replace the signal processing in the visual system bypassed by the prosthesis, electronic circuitry to generate electrical stimulus waveforms to elicit perceptions of light artificially, and stimulating electrodes placed in close proximity to the target neural tissue to deliver the electric charge. Furthermore, the implanted portion of the system has to be encapsulated properly to ensure longevity and biocompatibility.

At the time of writing, no commercially available product was available to provide artificial vision. However, several major research groups are working toward developing such a therapeutic device. Simple prototypes have been tested successfully in acute and chronic animal trials and more recently in small‐scale human trials. Psychophysical studies show that, despite the limited functionality of these prototypes, the recipients can successfully execute some simple visually guided tasks.
Optimization of physico‐mechanical properties of silica‐filled NR/SBR compounds
Authors: Salimi D. , Khorasani S. Nouri , Abadchi M. Rezaei , Veshare S. Jahanbani
Published: January 2010

In this extended study, the effect of silica reinforcement on natural rubber (NR) and NR/styrene–butadiene rubber (SBR) compounds was studied. The silica surfaces were treated with bis(3‐triethoxysilylpropyl)‐tetrasulfide, which is a silane‐coupling agent, to chemically bond the silica to the rubber. Optimum levels of silane were determined according to the silica loading in NR compounds. Results in NR/SBR compounded with optimum levels of silane show that the cure time decreases with increasing NR content. Also, the tensile properties of the NR/SBR blends decrease with increasing SBR content. This study further confirmed that filler materials affect the physical and mechanical properties of these blends. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 28:224–232, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20169
CFD simulations of hydrodynamic/thermal coupling phenomena in a bubble column with internals
Authors: Laborde‐Boutet Cédric , Larachi Faiçal , Dromard Nicolas , Delsart Olivier , Béliard Pierre‐Emmanuel , Schweich Daniel
Published: January 2010

CFD simulations have been carried out in a full three‐dimensional, unsteady, Eulerian framework to simulate hydrodynamic/thermal coupling in a bubble column with internals. A first part of the study, dedicated to the hydrodynamic/thermal coupling in liquid single‐phase flows, showed that assuming constant wall temperature on the internals constitutes a reasonable approximation in lieu of comprehensive simulations encompassing shell flow and coolant flow together. A second part dealing with the hydrodynamics of gas–liquid flows in a bubble column with internals showed that a RNG k–ε turbulence model formulation accounting for gas‐induced turbulence was a relevant choice. The last part used these conclusions to build a hydrodynamic/thermal coupling model of a gas–liquid flow in a bubble column with internals. With a per‐phase RNG k–ε turbulence model and assuming constant wall temperature, it was possible to simulate heat transfer phenomena consistent with experimentally measured heat transfer coefficients. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Laser heating of moving solid: Influence of workpiece speed on melt size
Authors: Shuja Shahzade Z. , Yilbas Bekir S. , Momin Omeir
Published: January 2010

Laser heating of a moving solid is considered and phase change in the irradiated region is modeled. Three‐dimensional heating situation is considered in the analysis and phase change is modeled using the enthalpy‐porosity technique. Temperature field and melt zone are predicted for different workpiece velocities. The predictions are compared with the experimental results. It is found that the maximum temperature in the irradiated region and the size of heat affected zone increase significantly at low workpiece speeds. The prediction of melt depth agrees well with the experimental results. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Brief communication: Transportation and trauma: Dog‐sledding and vertebral compression in Alaskan Eskimos
Authors: Legge Scott S.
Published: January 2010

Vertebral compression, as evidenced by compression of the centrum, was observed within two Native Alaskan skeletal samples. Information was collected from 1,071 and 656 vertebrae from Golovin Bay and Nunivak Island, Alaska, respectively. In addition, patterns of compression related vertebral change in each collection were characterized by sex and location within the vertebral column. The overall frequencies of vertebral compression were 3.6% (n = 721) at Golovin Bay and 1.7% (n = 403) at Nunivak Island for all observable thoracic and lumbar vertebrae (T1–L5). There was no statistically significant difference in the occurrence of compression among adults between these two collections. When examining the thoracic and lumbar vertebral segments by sex, females at Golovin Bay (4.5%; n = 442) exhibited a significantly higher frequency of vertebral compression than females at Nunivak (1.0%; n = 203). However, this difference in occurrence of compression could be accounted for by the age distributions of the two samples. No difference was noted between the males of the two collections. Compression frequencies in both samples are discussed in relation to the modes of transportation historically utilized by each community. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.
Host intrinsic determinants and potential consequences of parasite infection in free‐ranging red‐fronted lemurs (Eulemur fulvus rufus)
Authors: Clough Dagmar , Heistermann Michael , Kappeler Peter M.
Published: January 2010

Parasites and infectious diseases represent ecological forces shaping animal social evolution. Although empirical studies supporting this link abound in various vertebrate orders, both the study of the dynamics and impact of parasite infections and infectious diseases in strepsirrhine primates have received little empirical attention. We conducted a longitudinal parasitological study on four groups of wild red‐fronted lemurs (Eulemur fulvus rufus) at Kirindy Forest, Madagascar, during two field seasons in consecutive years to investigate i) the degree of gastrointestinal parasite infection on population and individual levels and ii) factors potentially determining individual infection risk. Using a comprehensive dataset with multiple individually assignable parasite samples as well as information on age, sex, group size, social rank, and endocrine status (fecal androgen and glucocorticoid), we examined parasite infection patterns and host traits that may affect individual infection risk. In addition, we examined whether parasite infection affects mating and reproductive success. Our results indicated high variability in parasite infection on individual and population levels. Time of year and group size was important determinants of variability in parasite infection. Variation in hormone levels was also associated with parasite species richness and parasite infection intensity. Differences in parasite infection between years indicate a potential immune‐enhancing function of steroid hormones on nematode infections, which has not been reported before from other vertebrates studied under natural conditions. Male mating and reproductive success were not correlated to any measure of parasite infection, which suggests a nonfunctional role of the parasites we examined in primate sexual selection. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.
Chitosan modified MMT‐poly(AMPS) nanocomposite hydrogel: Heating effect on swelling and rheological behavior
Authors: Kabiri K. , Mirzadeh H. , Zohuriaan‐Mehr M. J.
Published: January 2010

Vulnerability of hydrogels against thermal circumstances may be substantially eliminated via incorporating nanoclay to prepare nanocomposite hydrogels. In this research, chitosan‐intercalated montmorillonite (ChitoMMT) was used as a bionanoclay to yield novel nanocomposite hydrogels based on 2‐acrylamido‐2‐methylpropanesulfonic acid. The bionanoclay is suitable especially for preparing biomaterials used in biomedical, food, and pharmaceutical applications, unlike conventional commercial nanoclays (alkyl ammonium‐intercalated MMT) which are not appropriate for bio‐applications due to toxicity of the intercalant particularly where the clay content is high. Two different crosslinkers (i.e., methylene bisacrylamide, and polyethyleneglycol dimethacrylate) were employed to synthesize the nanocomposites. The variations in swelling, rheological and thermal properties of the hydrogels were essentially attributed to thermally induced crosslink cleavage/formation depending upon the crosslinker nature. The nanocomposites comprised superior thermal properties in comparison with the clay‐free hydrogel counterpart. They can preserve substantially their swelling ability for longer heating periods. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of polyfunctional monomer on melt strength and rheology of long‐chain branched polypropylene by reactive extrusion
Authors: Su Feng‐Hua , Huang Han‐Xiong
Published: January 2010

Long chain branching (LCB) were added to linear polypropylene (PP) using reactive extrusion in the presence of selected polyfunctional monomers (PFMs) and a peroxide of dibenzoyl peroxide (BPO). Fourier Transformed Infrared spectra (FTIR) directly confirmed the grafting reaction occurred during the reactive extrusion process. Various rheological plots including viscosity curve, storage modulus, Cole‐Cole plot, and Van‐Gurp plots, confirmed that the LCB structure were introduced into modified PPs skeleton after modification. In comparison with linear PP, the branched samples exhibited higher melt strength, lower melt flow index, and the enhancement of crystallization temperature. The LCB level in modified PPs and their melt strength were affected by the type of PFM used and could be controlled by the PFM properties and structure. PFMs with lower boiling points, such as 1, 4‐butanediol diacrylate (BDDA), could not produce LCB structure in modified PP skeleton. The shorter molecular chain bifunctional monomers, such as 1,6‐hexanediol diacrylate (HDDA), favored the branching reaction if their boiling points were above the highest extrusion temperature. And some polar groups, such as hydroxyl, in the molecule of PFM were harmful to the branching reaction, which might be attributed to the harm of the polarity of groups to the dispersion of PFM in PP matrix. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
An introduction to computer‐assisted train dispatch
Authors: Petersen E. R. , Taylor A. J. , Martland C. D.
Published: January 2010

This paper provides a framework for assessing the progress that is being made in the computer‐assisted dispatching of trains. The state of the art is described in general terms, and future research needs are identified.
Research contributions to managing transit service reliability
Authors: Abkowitz Mark , Tozzi John
Published: January 2010

Service reliability problems are a major concern shared by transit system users and operators. Unreliable service leads to additional vehicle requirements and higher operating costs; passengers suffer increased wait time and higher travel time uncertainty, leading to a general dissatisfaction with service and the possibility of seeking other means of transport. Because of the significance of this problem, considerable research attention has been focused in recent years on developing ways to improve service reliability.

This paper examines contributions which have been made to managing transit service reliability. This topic encompasses the subjects of vehicle run time, run time variation, headway variation, passenger wait time, and reliability control. Both theoretical and empirical approaches have been undertaken, and each has contributed to our knowledge in addressing the overall problem. Significant contributions to the state‐of‐the‐art are reported and the implications on present practice are discussed.
Geographical variation in traffic‐related mortality and morbidity among pedestrians in Quebec, 1983‐1988
Authors: Joly Marie‐France , Thouez Jean‐Pierre , Bourbeau Robert , Bussière Yves , Rannou André
Published: January 2010

In this study we analyze the dmographic and geographical distribution of pedestrian accidents (n=28,452) in the Quebec Municipalités régionales de comté (MRC) reported between January 1, 1983 and December 31, 1988. In order to be able to make comparisons between MRCs, we have created in Comparative Mortality Index and a Comparative Morbidity Index. We use a logistic regression model to single out explanatory factors. The main tendencies which are apparent in the demographic analysis are an overrepresentation of young persons and elderly persons in the accident statistics, and that men are more at risk than women. Men 15 years and under and men 65 years and over are more at risk of being involved in a fatal pedestrian accident. The geographic analysis show that among men, the average mortality rate is one and a half times greater in rural MRCs than in urban MRCs; among women, rural mortality is two and a half times greater than urban mortality. In the case of non‐severe injuries we note an over‐representation of urban MRCs. Young persons 15 years or less who live in an urban, populated zone are those most at risk of being involved in a pedestrian accident. Identifying high risk groups or areas is a prerequisite step for injury prevention and control.
Effect of local operational constraints on runway capacity ‐ A case study
Authors: Fan Henry S. L.
Published: January 2010

The estimation of runway capacity is important in airport planning and operational analysis. Standard procedures for capacity determination typically assume that there is no constraint on aircraft operations and do not provide good estimates when constraints exist. This paper presents a study of runway capacity at Singapore Changi Airport in which local operational constraints are taken into account. In addition, the impacts on capacity due to marine vessel crossings in a shipping channel near the airport, and the timing for implementation of simultaneous, independent instrument approach procedures are also investigated. The levels of annual aviation demand that could be served without excessive delays to aircraft under various operating scenarios are estimated.
Safe design of personal rapid transit systems
Authors: Anderson J. Edward
Published: January 2010

The safety of personal rapid transit systems involves careful attention to all features of the design such as the use of a hierarchy of fault‐tolerant redundant control systems, bi‐stable fail‐safe switching, back‐up power supplies, vehicle and passenger protection, and attention to the interaction of people with the system. Safety, together with reliability and adequate capacity, must be achieved while making the system economically attractive, hence techniques to achieve these goals at minimum life‐cycle cost are primary in PRT design. Building on theory of safe, reliable, environmentally acceptable, and cost‐effective design of PRT systems developed during the 1970′s, in 1981 the author and his colleagues initiated design of a new PRT system, now called Taxi 2000. The paper describes the relevant features of Taxi 2000 and principles of safe design incorporated into it.
Synchronous or clear‐path control in personal rapid transit systems
Authors: Anderson J. Edward
Published: January 2010

This note derives an equation for the ratio of the maximum possible station flow to average line flow in a personal rapid transit or dual‐mode system using fully synchronous control. It is shown that such a system is impractical except in very small networks.
Procurement methods for automated guideway transit systems
Authors: Jakes Andrew S.
Published: January 2010

Procurement of an Automated Guideway Transit (AGT) system is a relatively new process for many procuring agencies worldwide. Outside of large airports, no single transit market sector has enough experience to establish well proven procurement methodologies for innovative transit technologies. Several methods, however, have emerged recently which, together with more conventional approaches, make the decision making process quite complex. The objective of this article is to review currently used and recently considered procurement methods and recommend a methodology for their selection depending on specific project requirements.