31 research outputs found
Implementation of a Low stiffness motor drive in an Optical disc mastering device
No full textThis thesis report describes the implementation of a low stiffness motor drive in an optical disc mastering device. This research project is subsidized by an innovation-driven research program (IOP) by the Dutch government, which stimulates innovative research in Dutch universities. Readers who are interested in disturbance approximation in a brushless, ironless motor should read the first part of Chapter 3, whereas the last part of Chapter 3 describes the effect of motor implementation on position accuracy for this specific application. Disturbance minimization methods to minimize motor related disturbances are proposed in Chapter 4.Electrical Power EngineeringElectrical Engineering, Mathematics and Computer Scienc
GATE convection subprogramme: field phase report
No full textAssisted by J. L. Rasmussen and W. Murray of the U.S. GATE Project Office.February, 1975.A summary of the in-field decisions affecting the GATE Convection Subprogramme (C.S.P.) objectivesa preliminary tabulation and discussion of the data collectionand a discussion of the work of the Special Analysis Group in Dakar. Preliminary tables are presented of the upper air data coverage for the B and A/B ship arrays, the C-band ship radars, the SMS satellite coverage and the multi-aircraft missions flown in support of the C.S.P.A preliminary assessment of the subprogramme observational objectives is given
Near-future CO2 levels impair the olfactory system of a marine fish
No full textThis is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this recordData availability:
All raw sequence data are accessible at the NCBI Sequence Read Archive through accession number SRP097118. Water chemistry, behaviour and electrophysiology data are available through Pangaea (https://doi.pangaea.de/10.1594/PANGAEA.884674).Survival of marine fishes that are exposed to elevated near-future CO2levels is threatened by their altered responses to sensory cues. Here we demonstrate a physiological and molecular mechanism in the olfactory system that helps to explain altered behaviour under elevated CO2. We combine electrophysiology measurements and transcriptomics with behavioural experiments to investigate how elevated CO2affects the olfactory system of European sea bass (Dicentrarchus labrax). When exposed to elevated CO2(approximately 1,000 µatm), fish must be up to 42% closer to an odour source for detection, compared with current CO2levels (around 400 µatm), decreasing their chances of detecting food or predators. Compromised olfaction correlated with the suppression of the transcription of genes involved in synaptic strength, cell excitability and wiring of the olfactory system in response to sustained exposure to elevated CO2levels. Our findings complement the previously proposed impairment of γ-aminobutyric acid receptors, and indicate that both the olfactory system and central brain function are compromised by elevated CO2levels.This study was supported by grants from Association of European Marine Biology Laboratories (227799), the Natural Environment Research Council (R.W.W.; NE/H017402/1), the Biotechnology and Biological Sciences Research Council (R.W.W.; BB/D005108/1), Fundação para a Ciência e Tecnologia (Portuguese Science Ministry) (UID/Multi/04326/2013) and a Royal Society Newton International Fellowship to C.S.P. C.S.P. is also a beneficiary of a Starting Grant from AXA
Differential transcriptomic responses to heat stress in surface and subterranean diving beetles
No full textSubterranean habitats are generally very stable environments, and as such evolutionary transitions of organisms from surface to subterranean lifestyles may cause considerable shifts in physiology, particularly with respect to thermal tolerance. In this study we compared responses to heat shock at the molecular level in a geographically widespread, surface-dwelling water beetle to a congeneric subterranean species restricted to a single aquifer (Dytiscidae: Hydroporinae). The obligate subterranean beetle Paroster macrosturtensis is known to have a lower thermal tolerance compared to surface lineages (CTmax 38 °C cf. 42–46 °C), but the genetic basis of this physiological diference has not been characterized. We experimentally manipulated the thermal environment of 24 individuals to demonstrate that both species can mount a heat shock response at high temperatures (35 °C), as determined by comparative transcriptomics. However, genes involved in these responses difer between species and a far greater number were diferentially expressed in the surface taxon, suggesting it can mount a more robust heat shock response; these data may underpin its higher thermal tolerance compared to subterranean relatives. In contrast, the subterranean species examined not only diferentially expressed fewer genes in response to increasing temperatures, but also in the presence of the experimental setup employed here alone. Our results suggest P. macrosturtensis may be comparatively poorly equipped to respond to both thermally induced stress and environmental disturbances more broadly. The molecular fndings presented here have conservation implications for P. macrosturtensis and contribute to a growing narrative concerning weakened thermal tolerances in obligate subterranean organisms at the molecular level.Perry G. Beasley-Hall, Terry Bertozzi, Tessa M. Bradford, Charles S. P. Foster, Karl Jones, Simon M.Tierney, William F. Humphreys, Andrew D.Austin, Steven J. B. Coope
Developing a critical theory of child abuse : a discussion of the nature of child abuse as a manifestation of the social order
No full textThis thesis is an exploration into the nature and the prevalence of
child abuse. It incorporates in this investigation how children
understand abuse, and how the child may reject or oppose it. Its
origins lie in the experiences and observations I made as a local
authority social worker where children were silent, where child
abuse was seen as an event, a distinct moment within family life,
and with apparently little recognition of its relationship with the
social order. Arising from this observation, I consider how the
care of children may be a manifestation of the social order. This
thesis is therefore also a critique of the present theory and
practice of working within the field of childcare.
The premise taken here is that in order to understand abuse, there
must be an account of the individual's sense of being, as this
relates to wider issues of the political economy. Thus this
investigation uses the perspective of critical theory, since
critical theory can incorporate an analysis of both structure and
the experiential. It enables the researcher to shift perspective
and to focus on different levels and aspects of being.
Therefore, since child abuse is situated within the family, an
analysis based on the perspectives of critical theory is used to
examine family relationships. This includes an examination of the
relationships between parents, as well as of those between them and
the child. Three different facets of family life are explored:
that of gender construction from the viewpoint of feminist
psychoanalysis; the relationship between the social order and
interpersonal behaviour from the perspective of Marx and radical
feminism; and parental authority, drawing on the work of Laing.
Derived from this exploration, the key concepts of patriarchy,
alienation and mystification inform the direction of the empirical
investigation.
The empirical investigation, using firstly autobiographies of
childhood and then direct interviews with children, explores
further these concepts'. The autobiographies are used as a way of
sensitising oneself to the issues for the child, and as a means of
categorising experiences for the subsequent interviews with
children. From this reading, an alternative understanding of child
abuse is developed, one which differs from the narrow definition
used by organisations. Hence abuse can be seen as the experience
of hurt and pain, either emotional or physical, and which takes
place in a relationship based on the parental domination, control
and exploitation of the child. This understanding of abuse
situates the subjective experience within an interpersonal dynamic
of power and subordination.
Using this definition in analysing the interviews with children, it
was apparent that all children expedrience a form of abuse to some
degree. Abuse is not, therefore, the property of a small number of deviant families. Additionally it is argued that children are
silenced and rendered powerless within the family by three
mechanisms: firstly by the 'privacy control mechanism', secondly by
the 'ideology of paternalism', and thirdly by mystification. These
can be interpreted as also reinforcing the social order, since this
also depends for its maintenance on domination, powerlessness, and
mystification of the mechanisms of control.
The thesis concludes with a number of proposals for further
exploring these concepts in terms of developing sociological theory
and social work practice. The report on the death of Jasmine
Beckford is subjected to an alternative analysis, and derived from
this critique, ways of confronting violence, mystification and
privacy are discussed. Finally the thesis stresses the importance
of understanding child abuse as a personal as well as a social
phenomenon, and that it has ultimately, a political significance
Biochemistry of secondary metabolism of fungi
No full textFungi, eukaryotic organisms with a kingdom of their own, include microorganisms
from moulds and yeasts to the most known and appreciated mushrooms.
The incredible biodiversity of these organisms is not limited to their morphology but
is reflected in their chemistry, namely in the variety of compounds they produce.
Therefore, like other living beings, fungi can be an excellent source of bioactive
compounds.
Although they may be primary metabolites, fungal bioactive compounds are
mainly produced through secondary metabolism. These compounds have an essential
role in the fungal survival and adaptation to almost all habitats on earth. Besides,
they can also exert beneficial effects on human health, such as antioxidant, antimicrobial,
anti-UV radiation, or even anti-inflammatory or antitumor activity. Given
the wide bioactivity of the molecules produced, fungi have become, over time, an
exciting source of compounds with possible application in various industries,
including the food, pharmaceutical, or cosmetics industries.
Fungal secondary metabolites are mainly produced via acetyl-CoA and via the
shikimate pathway. Even though it is possible to find in the literature some different
classifications regarding secondary metabolites of fungi, in this manuscript, we
define polyketides, non-ribosomal peptides, terpenoids, and indole alkaloids as the
main structural classes.
The present chapter will present a brief introduction to fungal secondary metabolism,
including some examples of the most well-known compounds and their principal functions in ecosystems. The biosynthetic pathways of the main classes of
fungal secondary metabolites will also be depicted.FCT, Portugal for financial support through national funds FCT/MCTES to
the CIMO (UIDB/00690/2020), and the Bio Based Industries Joint Undertaking (JU) under the
grant agreement No 888003 UP4HEALTH Project (H2020-BBI-JTI-2019), whom the author
F.S. Reis thanks for her contract.
L. Barros thank the national funding by FCT, P.I., through the institutional scientific employment program-contract for her contract. T. Oludemi and T.C.S.P. Pires thank the MICINN for their
Juan de la Cierva Formación contract (FJC2019-042549-I and FJC2020-045405-I, respectively).
The authors also thank the FEDER-Interreg España-Portugal programme through the project
TRANSCoLAB 0612_TRANS_CO_LAB_2_P.info:eu-repo/semantics/publishedVersio
Shrinking in the dark: Parallel endosymbiont genome erosions are associated with repeated host transitions to an underground life
No full textFirst published: 10 March 2024Microbial symbioses have had profound impacts on the evolution of animals. Conversely, changes in host biology may impact the evolutionary trajectory of symbionts themselves. Blattabacterium cuenoti is present in almost all cockroach species and enables hosts to subsist on a nutrient-poor diet. To investigate if host biology has impacted Blattabacterium at the genomic level, we sequenced and analyzed 25 genomes from Australian soil-burrowing cockroaches (Blaberidae: Panesthiinae), which have undergone at least seven separate subterranean, subsocial transitions from above-ground, wood-feeding ancestors. We find at least three independent instances of genome erosion have occurred in Blattabacterium strains exclusive to Australian soil-burrowing cockroaches. These shrinkages have involved the repeated inactivation of genes involved in amino acid biosynthesis and nitrogen recycling, the core role of Blattabacterium in the host-symbiont relationship. The most drastic of these erosions have occurred in hosts thought to have transitioned underground the earliest relative to other lineages, further suggestive of a link between gene loss in Blattabacterium and the burrowing behavior of hosts. As Blattabacterium is unable to fulfill its core function in certain host lineages, these findings suggest soil-burrowing cockroaches must acquire these nutrients from novel sources. Our study represents one of the first cases, to our knowledge, of parallel host adaptations leading to concomitant parallelism in their mutualistic symbionts, further underscoring the intimate relationship between these two partners.Perry G. Beasley-Hall, Yukihiro Kinjo, Harley A. Rose, James Walker, Charles S. P. Foster, Toby G. L. Kovacs, Thomas Bourguignon, Simon Y.W. Ho and Nathan L
A web-based requirements elicitation tool using focus group discussion in supporting computer-supported collaborative learning requirements development
No full textDeveloping correct requirements for any application is vital for the success of the application in any field. Computer-supported collaborative learning (CSCL) has becoming an important tool for enabling collaborative learning (CL) in education. In Malaysia for instance CSCL has been chosen to be a technology enabler to support Smart School project whereby CL has been identified as one of its learning strategies (MOE, 1997). However, the project will not come true if the lacking of CSCL application is not overcome. The situation is more acute as the existing applications are not only general in nature but yet to exhibit collaborative characteristics. This problem is due to many reasons. From the software engineering point of view, first and foremost, the problem is introduced during the elicitation of users needs. A survey carried out by the author had been identified that users are not the first people consulted by courseware developers in eliciting requirements. Furthermore, the courseware developers have no support in carrying out requirements elicitation activity. In conjunction to this, a review was also carried out in requirements elicitation techniques and process. Many methods have been identified and implemented to support requirements elicitation activity. Most of them are group-based, which support the cooperativeness of the requirements elicitation activity. However, the existent of these tools are not recognized in the Malaysian context. Due to this, a new requirements elicitation tool using Focus Group Discussion (FGD) technique is developed based on the survey done and the literature survey carried out. The tool is called FGD-RElicit stands for Focus Group Discussion technique in Requirements Elicitation. This paper focuses on the development of FGD-RElicit from its technique used in supporting elicitation, analysis model, design and architecture. Results of evaluation by the users are also included the paper is wrapped up
Assessment of Inter-Laboratory Differences in SARS-CoV-2 Consensus Genome Assemblies between Public Health Laboratories in Australia
No full textWhole-genome sequencing of viral isolates is critical for informing transmission patterns and for the ongoing evolution of pathogens, especially during a pandemic. However, when genomes have low variability in the early stages of a pandemic, the impact of technical and/or sequencing errors increases. We quantitatively assessed inter-laboratory differences in consensus genome assemblies of 72 matched SARS-CoV-2-positive specimens sequenced at different laboratories in Sydney, Australia. Raw sequence data were assembled using two different bioinformatics pipelines in parallel, and resulting consensus genomes were compared to detect laboratory-specific differences. Matched genome sequences were predominantly concordant, with a median pairwise identity of 99.997%. Identified differences were predominantly driven by ambiguous site content. Ignoring these produced differences in only 2.3% (5/216) of pairwise comparisons, each differing by a single nucleotide. Matched samples were assigned the same Pango lineage in 98.2% (212/216) of pairwise comparisons, and were mostly assigned to the same phylogenetic clade. However, epidemiological inference based only on single nucleotide variant distances may lead to significant differences in the number of defined clusters if variant allele frequency thresholds for consensus genome generation differ between laboratories. These results underscore the need for a unified, best-practices approach to bioinformatics between laboratories working on a common outbreak problem
