1,721,063 research outputs found
Space medicine: use of ex vivo human respiratory mucosa in the survey of the effects of microgravity on the respiratory system
Full text linkIn the near future, the length and scope of space travel is
set to increase significantly. The number of individuals who
will have access to extra-terrestrial travels is also increasing.
In view of the growing international interest towards manned
long-term space exploration, possible effects of exposure to
microgravity conditions affecting the respiratory system are
subject of interest by major space agencies (NASA and ESA
primarily). Our team has developed an advanced 3d tissue
model of the human bronchial mucosa within a wide research
project involving several universities and space agencies at
international level. The model will be used to study the structural/functional alterations of the bronchial mucosa that may arise from prolonged exposure to reduced gravity conditions.
Among the different modifications to be evaluated: development and performance of the pulmonary barrier; possible ciliogenesis modification due to its effects on fluid mechanics
and mechanotransduction; formation of multi-cellular structures (Cell-Cell and ECM-Cell Interactions). The design and
realization of experiments aboard the International Space
Station (ISS) often clashes with greater difficulties than at
ground level. Our work was to check the resilience of the
model to the prohibitive environmental conditions present on
board the vectors that transport the samples to the ISS, and to
adapt the model to engineering requirements for proper functionality within the BIOLAB of ISS itself. To verify this, cell cultures were subjected to various boundary conditions: temperatures lower than growth optimum, reduced concentrations of
CO2, restriction of gas exchange, prolonged starvation and
storage of the culture medium at high temperatures. The
bronchial mucosa cultures were analysed at the end of the
treatments and their morphology was evaluated. We also
used the monitoring of the Trans Epithelial Electric Resistance
to evaluate the state of health of the cultures. The data
obtained demonstrated how this culture model is able to overcome the critical phases of the journey to ISS and how it can conform to restrictive engineering requirements. It is possible
to assert that in addition to the accurate reproduction of the
bronchial human mucosa, the cell culture model possesses the
characteristics necessary to be used in studies in an extreme
environment such as the ISS, being able to provide data that
could be relevant for future manned spaceflights
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Anatomy and Physiology of the Peripheral and Central Auditory System
No full textThe auditory system is responsible for the hearing sense and it consists of the peripheral auditory system (outer, middle and inner ear) and of the central auditory system (vestibular and cochlear nuclei, auditory and vestibular pathways and vestibular and auditory cortices). The outer ear comprises the auricle and the auditory canal and its function is to guide air pressure waves to the middle ear. The middle ear consists of the tympanic membrane, connected to the inner ear by three ossicles (malleus, incus and stapes), which vibrations allow the transmission of originally airborne sound waves to the perilymph of the inner ear. The middle ear provides a pressure gain as well as enhanced quality of the sound waves transmitted to the inner ear and protects it from high pressure levels produced by loud sounds. The stapes footplate of the middle ear connects to the oval window of the cochlea, an inner ear spiral-shaped bony canal. The stapes of the middle ear connects to the oval window in the cochlea. The vibrations of a flexible membrane (basilar membrane) on which sensory cells (hair cells) reside are responsible for the transduction of the sound waves into electrical impulses.
The vestibulocochlear nerve (CN VIII) transmits both hearing and balance information from the inner ear to the brain. The vestibular (balance) and cochlear (hearing) components of the vestibulocochlear nerve target different nuclei. The vestibular component reaches the vestibular nuclei in the pons and medulla oblongata. The cochlear component instead reaches the ventral and dorsal cochlear nuclei, located laterally at the junction between the pons and medulla, in close proximity to the inferior cerebellar peduncle. CN VIII emerges from the brainstem at the cerebellopontine angle
and exits the posterior cranial fossa of the neurocranium through the internal acoustic meatus of the temporal bone. Here the vestibulocochlear nerve splits, thus forming the vestibular nerve and the cochlear nerve. The vestibular nerve innervates the vestibular system of the inner ear, which is responsible for detecting balance. The cochlear nerve travels to the cochlea, forming the spiral ganglia of Corti, involved in the sense of hearing.
The hearing pathway originates in the cochlear nuclei which receive first-order auditory input from the organ of Corti in the cochlea. The second neuron of this pathway is located in the superior olivary nuclei of the pons where the majority of the auditory fibers synapse, crossing the midline. The fibers ascend, forming the lateral lemnisc and proceed towards the inferior colliculus in the mesencephalus. The last relay, prior to the primary auditory cortex, occurs in the medial geniculate body of the thalamus. A tonotopic organization is evident throughout the hearing pathway, from cochlea to auditory cortices.
In the balance pathway, neurons synapsing on the hair cells of maculae and cristae ampullares of the semicircular canals converge in the vestibular ganglion. The sensory fibers originating from here join the sensory fibers from the cochlear ganglion to form the vestibulocochlear nerve and terminate in the vestibular nuclei of the pons and medulla. The axons originated in these nuclei reach different areas of Central Nervous System (CNS), such as the spinal cord, the cerebral cortex, the cerebellum and the nuclei controlling extrinsic eyes muscles. The vestibular nuclei also receive input from proprioceptive neurons, as well as the visual system
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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