2,387 research outputs found
The assessment of researchers' competence in experimental procedures with laboratory animals: A three-step methodology to develop a global rating scale
To conduct animal experiments, researchers must be competent to handle and perform interventions
on living animals in compliance with regulations. Laboratory animal science training programs and
licensing bodies therefore need to be able to reliably ensure and certify the professional competence
of researchers and technicians. This requires access to assessment strategies which can verify
knowledge as well as capturing performative and behavioral dimensions of assessment. In this paper,
we describe the process of developing different global rating scales measuring candidates’
competence in a performative assessment. We set out the following sequence, with three crucial
phases, in the process of scale development: (A) Item Development, (B) Scale Development, and (C)
Piloting of the Scale. We note each phase’s different sub-steps. Despite the emergent need to ensure
the competence of researchers using animals in scientific procedures, to our best knowledge there
are very few species and procedure/skill specific assessment tools for this purpose, and the
assessment methodology literature in the field is very limited. This paper provides guidance for those
who need to develop and assess proficiency in laboratory animal procedures by setting out a method
that can be used to create the required tools and illustrating how competence assessment strategies
can be implemented.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or
publication of this article: this work is a result of the project funded by Norte01- 0145-FEDER-000008
– Porto Neurosciences and Neurologic Disease Research Initiative at i3S, supported by Norte Portugal Regional Operational Programme (NORTE2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (FEDER)
UV-Deprived Coloration Reduces Success in Mate Acquisition in Male Sand Lizards (Lacerta agilis)
Background: Recent work on animal signals has revealed a wide occurrence of UV signals in tetrapods, in particular birds, but also in lizards (and perhaps other Squamate reptiles). Our previous work on the Swedish sand lizard (Lacerta agilis) has verified, both in correlative selection analyses in the wild and with laboratory and field experiments, the importance of the green ‘badge ’ on the body sides of adult males for securing mating opportunities, probably mostly through deterring rival males rather than attracting females. The role of UV in communication has, however, never been examined. Methodology/Principal Findings: Here we show that when measured immediately after spring skin shedding, there is also signaling in the UV. By UV-depriving the signal (reflectance) with sun block chemicals fixated with permeable, harmless spray dressing, we show that males in the control group (spray dressing only) had significantly higher success in mate acquisition than UV-deprived males. Conclusions/Significance: These results suggest that at least two colour traits in sand lizards, badge area and UV, contribute to rival deterrence and/or female choice on UV characters, which elevates success in mate acquisition in UV intact male sand lizards
BNCI systems as a potential assistive technology: ethical issues and participatory research in the BrainAble project
This paper highlights aspects related to current research and thinking about ethical issues in relation to Brain Computer Interface (BCI) and Brain-Neuronal Computer Interfaces (BNCI) research through the experience of one particular project, BrainAble, which is exploring and developing the potential of these technologies to enable people with complex disabilities to control computers. It describes how ethical practice has been developed both within the multidisciplinary research team and with participants. Results: The paper presents findings in which participants shared their views of the project prototypes, of the potential of BCI/BNCI systems as an assistive technology, and of their other possible applications. This draws attention to the importance of ethical practice in projects where high expectations of technologies, and representations of “ideal types” of disabled users may reinforce stereotypes or drown out participant “voices”. Conclusions: Ethical frameworks for research and development in emergent areas such as BCI/BNCI systems should be based on broad notions of a “duty of care” while being sufficiently flexible that researchers can adapt project procedures according to participant needs. They need to be frequently revisited, not only in the light of experience, but also to ensure they reflect new research findings and ever more complex and powerful technologies
Three applications of path integrals: equilibrium and kinetic isotope effects, and the temperature dependence of the rate constant of the [1,5] sigmatropic hydrogen shift in (Z)-1,3-pentadiene
Recent experiments have confirmed the importance of nuclear quantum effects
even in large biomolecules at physiological temperature. Here we describe how
the path integral formalism can be used to describe rigorously the nuclear
quantum effects on equilibrium and kinetic properties of molecules.
Specifically, we explain how path integrals can be employed to evaluate the
equilibrium (EIE) and kinetic (KIE) isotope effects, and the temperature
dependence of the rate constant. The methodology is applied to the [1,5]
sigmatropic hydrogen shift in pentadiene. Both the KIE and the temperature
dependence of the rate constant confirm the importance of tunneling and other
nuclear quantum effects as well as of the anharmonicity of the potential energy
surface. Moreover, previous results on the KIE were improved by using a
combination of a high level electronic structure calculation within the
harmonic approximation with a path integral anharmonicity correction using a
lower level method.Comment: 9 pages, 4 figure
A new species of Stenobiella Tillyard (Neuroptera, Berothidae) from Australia
Stenobiella variola sp. n., a new species of beaded lacewing (Neuroptera: Berothidae), is described and figured from south-eastern Australia. A preliminary key to Stenobiella species is presented
Multiplexed, High Density Electrophysiology with Nanofabricated Neural Probes
Extracellular electrode arrays can reveal the neuronal network correlates of behavior with single-cell, single-spike, and sub-millisecond resolution. However, implantable electrodes are inherently invasive, and efforts to scale up the number and density of recording sites must compromise on device size in order to connect the electrodes. Here, we report on silicon-based neural probes employing nanofabricated, high-density electrical leads. Furthermore, we address the challenge of reading out multichannel data with an application-specific integrated circuit (ASIC) performing signal amplification, band-pass filtering, and multiplexing functions. We demonstrate high spatial resolution extracellular measurements with a fully integrated, low noise 64-channel system weighing just 330 mg. The on-chip multiplexers make possible recordings with substantially fewer external wires than the number of input channels. By combining nanofabricated probes with ASICs we have implemented a system for performing large-scale, high-density electrophysiology in small, freely behaving animals that is both minimally invasive and highly scalable
A new resorbable device for ligation of blood vessels - A pilot study
<p>Abstract</p> <p>Background</p> <p>During surgery, controlled haemostasis to prevent blood loss is vital for a successful outcome. It can be difficult to ligate vessels located deep in the abdomen. A device that is easy to use and enables secure ligatures could be beneficial. Cable ties made of nylon have been used for ligation but the non-resorbable material caused tissue reactions. The objective of this study was to use a resorbable material to construct a device with a self-locking mechanism and to test its mechanical strength and ligation efficiency.</p> <p>Methods</p> <p>The device was manufactured by injection moulding of polydioxanone, a resorbable polymer used for suture materials. Polydioxanone with inherent viscosities of 1.9 dL/g and 1.3 dL/g were tested. The device consisted of a perforated flexible band which could be pulled through a case with a locking mechanism. After a first version of the device had been tested, some improvements were made. The locking case was downsized, corners were rounded off, the band was made thicker and the mould was redesigned to produce longer devices. Tensile tests were performed with the second version.</p> <p>The first version of the device was used to ligate the ovarian pedicle in a euthanized dog and to test echogenicity of the device with ultrasound. Compression of vessels of the ovarian pedicle was examined by histology. Both versions of the device were tested for haemostasis of and tissue grip on renal arteries in six anaesthetised pigs.</p> <p>Results</p> <p>The tensile strength of the flexible band of the devices with inherent viscosity of 1.9 dL/g was 50.1 ± 5.5 N (range 35.2-62.9 N, <it>n </it>= 11) and the devices with inherent viscosity of 1.3 dL/g had a tensile strength of 39.8 ± 8.1 N (range 18.6-54.2 N, <it>n </it>= 11). Injection moulding of the polymer with lower inherent viscosity resulted in a longer flow distance.</p> <p>Both versions of the device had an effective tissue grip and complete haemostasis of renal arteries was verified. The device attached to the ovarian pedicle could be seen with ultrasound, and vessel compression and occlusion were verified by histology.</p> <p>Conclusions</p> <p>Tests of functionality of the device showed complete haemostasis and good tissue grip. Devices with a band of sufficient length were easily applied and tightened in tissue.</p
Association of tamoxifen use and reduced risk of contralateral breast cancer for BRCA1 and BRCA2 mutation carriers
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Revisiting Scalar and Pseudoscalar Couplings with Nucleons
Certain dark matter interactions with nuclei are mediated possibly by a
scalar or pseudoscalar Higgs boson. The estimation of the corresponding cross
sections requires a correct evaluation of the couplings between the scalar or
pseudoscalar Higgs boson and the nucleons. Progress has been made in two
aspects relevant to this study in the past few years. First, recent lattice
calculations show that the strange-quark sigma term and the
strange-quark content in the nucleon are much smaller than what are expected
previously. Second, lattice and model analyses imply sizable SU(3) breaking
effects in the determination on the axial-vector coupling constant that
in turn affect the extraction of the isosinglet coupling and the
strange quark spin component from polarized deep inelastic
scattering experiments. Based on these new developments, we re-evaluate the
relevant nucleon matrix elements and compute the scalar and pseudoscalar
couplings of the proton and neutron. We also find that the strange quark
contribution in both types of couplings is smaller than previously thought.Comment: 17 pages, Sec. II is revised and the pion-nucleon sigma term
extracted from the scattering data is discussed. Version to appear in JHE
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