1,721,084 research outputs found
Exploring sex differences in the response to tickling in juvenile Wistar rats
Full text linkPositive welfare is considered not simply the absence of suffering, but
also the presence of positive experiences. ‘Tickling’ induces positive affective
states in laboratory rats as evidenced by the production of 50 kHz ultrasonic
vocalisations (USVs). Few studies have investigated the effect of tickling on
females, and whether there is a sex difference in response to tickling and the
involvement of the neuroendocrine system. Here I investigated whether there
are sex differences in behavioural responses to tickling in juvenile Wistar rats
due to sex-specific neural regulation of positive affective states. I tested the
following hypotheses that: (i) specific elements of the behavioural response to
tickling (including USVs) differ between sexes; (ii) 50 kHz USV subtypes are
produced in a temporally specific manner during tickling, and they may be
paired with different behaviours observed during tickling; (iii) the behavioural
response to tickling is regulated by brain regions and neural circuits that are
associated with social play in rats, and this is sex specific; (iv) oxytocin and
vasopressin neurons in the paraventricular nucleus (PVN) and supraoptic
nucleus (SON) are involved in the behavioural response to tickling in a sex
specific manner; and (v) 50 kHz USV production in response to tickling is
related to measures of motivation for the reward of tickling, and this is greater
in females.
In experiment 1, rats were tickled or had no hand contact during two
minutes of testing per day for 10 days. Play-related behaviours (hand
approaches and solitary play) and 50 kHz USVs were quantified. Female rats
made more 50 kHz USVs after 10, but not five, days of tickling. Tickled rats
made more trill 50 kHz USVs, regardless of sex, while female rats emitted
more flat 50 kHz USVs than males after 10 days of testing. Both treatment and
sex affected flat 50 kHz USVs, with females producing more flat 50 kHz USVs
and regardless of sex, tickled rats producing more trill 50 kHz USVs than
controls. Females paired more flat 50 kHz USVs with scampering and
approaches, while tickled rats of both sexes paired more trills with those
behaviours. Tickled rats elicited more solitary play scampering than control
rats, and this was greatest in females. Tickling did not increase hand
approaches, and control females approached the hand more than tickled rats.
Double-labelled immunohistochemistry was used to quantify c-fos
expression (a neuronal activity marker) in oxytocinergic and vasopressinergic
neurons that are known to be involved in social behaviours (e.g. social
conspecific play) and reward pathways. Tickling did not increase Fos
immunoreactivity in the social behaviour, reward or mid- or hind-brain brain
regions. Control rats had more correlated Fos immunoreactivity between
regions of the social behaviour network and reward pathway. In the PVN,
tickled rats, regardless of sex, had lower numbers of Fos positive parvocellular,
but not magnocellular, oxytocin and vasopressin neurons. There was no effect
of tickling on Fos immunoreactivity in oxytocin and vasopressin SON neurons.
In experiment 2, rats were tickled or had no hand contact during two
minutes of testing per day for five days, followed by testing in a modified
runway test for two days to measure motivation for tickling, and a modified
preference test to measure preference for the hand over a novel object.
Tickling did not affect the time taken to traverse the runway, but tickled rats
made more total and trill 50 kHz USVs while traversing the runway. Tickling
did not change preference for a novel object or the hand, but control rats made
more visits to the novel object.
In summary, there are sex differences in the behavioural response to
tickling, but this appears to be dependent on the number of days of tickling and
specific to individuals. Tickling did not increase neuronal activity in key regions
associated with social behaviours and reward and this may be a consequence
of individual responses to tickling. Alternatively, tickling, while rewarding, was
not perceived as a social stimulus. This is an important consideration for future
tickling studies as tickling should not necessarily be construed as mimicking
rat social conspecific play and responses to tickling by both sexes should be
considered
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
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
Effects of sex steroids on spatial cognition in the zebra finch (Taeniopygia guttata)
Full text linkIt is well established in mammals that chronic, long-term elevations in sex steroids
are associated with improvements in spatial cognition. It is less clear the extent to
which short to medium term elevations in sex steroids improve spatial cognition and
change hippocampal morphology, particularly in birds. The avian hippocampus
expresses both androgen receptors (AR) and oestrogen receptor alpha (ERα) and
high levels of the enzyme aromatase that converts testosterone to oestrogen. I began
by comparing spatial cognition, hippocampal sex steroid receptor and aromatase
expression between males and females. There were no differences in spatial or
visual cognition or in hippocampal sex steroid receptor expression between the
sexes, although hippocampal aromatase mRNA expression was higher in males. I
then addressed the effects of acute and medium-term sex steroid treatment on spatial
cognition and hippocampal aromatase and sex steroid receptor expression. A single
treatment of testosterone 30 minutes or four hours prior to cognitive testing improved
spatial performance. Additionally, when testosterone and oestrogen were given daily
for five days spatial cognition in both sexes was improved. The testosterone-induced
improvement was blocked when testosterone was administered in conjunction with
the aromatase inhibitor fadrozole but not when administered with saline. These
findings suggest that spatial cognition is improved by an oestrogenic effect. Thirty
minutes following acute testosterone treatment, plasma testosterone levels,
hippocampal AR and ERα mRNA expression all increased. Five days of oestrogen
treatment increased plasma oestrogen levels, hippocampal ERα mRNA and Nmethyl-
D-aspartate (NMDA) receptor levels in males and females; all were
positively correlated with enhanced spatial cognition on day five of treatment.
Finally, I determined which genes were differentially expressed as a result of five
days of oestrogen treatment. Nineteen genes, identified as being involved in learning
and memory were differentially expressed in the hippocampus, eleven of which were
up-regulated and eight were down-regulated. Taken together these results
demonstrate that oestrogen can improve spatial cognition in birds. It is plausible that
oestrogen acts to improve spatial memory in the hippocampus through upregulation
of genes that control neurotransmitter release, reuptake and receptor levels
Methods of inducing and assessing positive affective states in juvenile male Wistar rats
No full textThe importance of animals having positive experiences is essential for animal
welfare as the balance of positive and negative affective states can be seen as
critical to determining an animal’s quality of life. However, a traditional focus on
alleviating negative affective states has meant that the complete assessment of
animal welfare is hindered by a relative lack of validated models of positive
affective states. This disparity between the measurement of positive and negative
affective states is particularly evident in rodents used for research. With over 1.9
million rats used for research purposes in the UK, USA and EU per annum as of
2018, contribution towards this gap in knowledge on positive affective states is vital to improving their welfare. As such, the aims of this doctoral research were
twofold; first, to develop models of inducing a positive affective state in rats, and
second, to investigate whether play is sensitive to the manipulation of affective
state as an indicator of PAW.
Playful handling is a recently developed approach to positive interactions between
humans and rats which aims to incorporate the diversity and unpredictability of
juvenile rat social play. To validate the use of playful handling as a method of
inducing a positive affective state in juvenile male rats, two independent cohorts
were either playfully handled or control handled over successive days, as
individuals or pairs. In response to playful handling, rats showed increased
production of 50-kHz ultrasonic vocalisations (USVs) compared to control rats, a
type of vocalisation associated with positive affect. Approach behaviour towards
the experimenter was higher when rats were playfully handled as individuals
compared to controls. I also measured rat preference for a high concentration
(20%) of sucrose over water as a prospective behavioural test of positive affect.
This was an adaption of the sucrose preference test which is a validated test of
negative affect which measures preference for a low concentration (sucrose over water. Rats which were playfully handled as individuals drank more
sucrose solution than control rats. Thus, there is potential for using a high concentration sucrose preference test as a measure of behavioural and neural
changes induced by a positive experience. This increase in indicators of positive
affect provides further evidence for the use of playful handling to induce a positive
affective state in rats.
Presentation of positively valenced rat-produced USVs in playback paradigms is a
novel method of altering affective state. This method is based on the premise that
as vocalisations have a communicative function associated with affective state, the
presentation of positive vocalisations will stimulate positive emotions in the
recipient. Four independent cohorts were used to develop a novel paradigm in
which acoustic stimuli could be presented in low-stress conditions. Across these
experiments, four acoustic stimuli were used; positively valenced 50-kHz USVs,
negatively valenced 22-kHz USVs, White Noise, and Background Noise. Across all
four experiments using the novel playback paradigm, the presentation of 50-kHz
stimuli increased subject-produced positively valenced 50-kHz USVs compared to
Background Noise. A single presentation of White Noise also increased 50-kHz
USVs to match those produced when presented with 50-kHz compared to
Background Noise. This effect of White Noise on USV production was not seen
after subsequent presentations, with USV production lowering to that of
Background Noise on day five. When the speaker was placed on the side of the
cage, there was also an increase in approach behaviour in response to 50-kHz
stimuli compared to 22-kHz and Background Noise. The differences in measures of affective state in response to the auditory stimuli across cohorts provide evidence that playback is a promising method of stimulating a positive affective state in rats.
Play behaviour is proposed to be a promising indicator of positive emotions and
welfare in domesticated animals. To investigate whether play changes with the
manipulation of affective state, home cage behaviour was recorded before and
after experiencing successive days of handling treatments or presentation of
acoustic stimuli. After five days, there was an increase in play in the home cage
prior to the experience in response to both playful handling and the playback of 50-kHz USVs. As these effects were specific to behaviour in the home cage occurring before the positive experience, this suggests that play may in part reflect a form of anticipatory behaviour. In the playback paradigm, the absence of a human-rat interaction also allowed the assessment of play during the presentation of acoustic stimuli. After five days of presentation with 50-kHz USVs, rats expressed more social play than those exposed to control stimuli. These results suggest there is a positive relationship between concurrent and pre-existing positive affective state and play.
Overall, this work provides support for the use of playful handling and presentation of 50-kHz USVs in a novel playback paradigm as methods to induce a positive affective state in rats. The successful manipulation of indicators of affective state allowed the investigation of play as an indicator of positive affect. As play was sensitive to increases in positive affect, there is evidence that play represents more than just the absence of a negative affective state and supports the use of play as an indicator of positive welfare
- …
