1,298 research outputs found
Exploring the hidden welfare problem of gastric ulceration in sows: behaviour and saliva composition as possible methods of diagnosis
Gastric ulcers are highly prevalent in the pig industry and evidence suggests probably affect pigs in all productive stages. Gastric ulcers affect pig welfare as they cause some degree of discomfort or pain (observed by a change in behaviour) as well as impacting performance. Gastric ulceration is a hidden problem as it is difficult to identify in living pigs and there is no method of diagnosis that is both non-invasive and affordable. In this thesis, I hypothesised that re-directed oral behaviours (e.g. sham chewing, biting bars) and changes in saliva characteristics may be of use for the diagnosis of gastric ulceration in pigs. Re-directed oral behaviours have been largely related with chronic hunger in sows which appear as a way to cope with a diet and environment that does not fulfil sows’ nutritional and behavioural needs. However, these behaviours have also been observed in finishing pigs as well as in gilts and sows fed ad libitum. Furthermore, there is some evidence that the behaviour of finishing pigs changes with the presence of gastric ulcers. Saliva composition has been reported to change with various illnesses or conditions but also, recently, with the presence of gastric ulcers in finishing pigs.
Chapter 2 describes oral behaviours present in finishing pigs and compares them to the behaviour of sows. All oral behaviours studied were observed in finishing pigs, and the rate was the same as compared to sows. The behaviours which were least frequent and performed by the least number of animals in both finishing pigs and gestating sows were self-directed oral behaviours. Self-directed oral behaviours are much more difficult to explain in finishing pigs as opposed to oral behaviours that involve the interaction with an object or conspecific.
Chapter 3 explored the relationship between self-directed oral behaviours (chewing movements, wind sucking, tongue playing and jaw stretching) and the presence of gastric ulcers in finishing pigs. All self-directed oral behaviours, but jaw stretching, were observed in both pigs with healthy and ulcerated stomachs (video observations). All observed behaviours were the same between both groups.
Chapter 4 explores the relationship between re-directed oral behaviours (live observations) as well as salivary composition and pH with gastric ulceration in gestating and lactating sows. All sows were found to have some level of ulceration and the prevalence of gastric ulcers was 67.57%. The rate of re-directed oral behaviours was not affected by overall stomach score or lesion score during either gestation or lactation. Salivary pH was not affected by stomach integrity. Saliva composition changed with the overall stomach score and lesion score in gestating and lactating sows. Lipoxin A4, Succinic acid and L-Histidine were identified as possible biomarkers of gastric ulceration.
Chapter 5 is a systematic literature review of the variation of re-directed oral behaviours according to housing system, diet and feeding practices, and environmental enrichment in gestating gilts and sows. All of the results of the included studies can be explained by ‘chronic hunger’ theory or their housing environment. Although the design of these studies was to test factors which relate to hunger and re-directed foraging, rather than the health of the upper digestive system.
This thesis shows that oral behaviours do not have a clear link with gastric ulceration in finishing pigs, or in gestating and lactating sows. However, oral behaviours were observed in finishing pigs and some of these remain unexplained (e.g. self-directed oral behaviours). Also, all re-directed oral behaviours in gestating gilts and sows can be explained by chronic hunger or housing environment as shown by the systematic literature review. Possibly, the remaining unexplained oral behaviours may be a response to an environment that is still insufficient for the pig to fulfill its behavioural needs and/or other conditions affecting the upper digestive system. Saliva composition is linked to gastric ulceration in gestating and lactating sows, and possible biomarkers were identified in this thesis. More studies are needed to identify and validate biomarkers for gastric ulceration in pigs
On the real world practice of Behaviour Driven Development
Surveys of industry practice over the last decade suggest that Behaviour Driven Development is a popular Agile practice. For example, 19% of respondents to the 14th State of Agile annual survey reported using BDD, placing it in the top 13 practices reported. As well as potential benefits, the adoption of BDD necessarily involves an additional cost of writing and maintaining Gherkin features and scenarios, and (if used for acceptance testing,) the associated step functions. Yet there is a lack of published literature exploring how BDD is used in practice and the challenges experienced by real world software development efforts. This gap is significant because without understanding current real world practice, it is hard to identify opportunities to address and mitigate challenges. In order to address this research gap concerning the challenges of using BDD, this thesis reports on a research project which explored: (a) the challenges of applying agile and undertaking requirements engineering in a real world context; (b) the challenges of applying BDD specifically and (c) the application of BDD in open-source projects to understand challenges in this different context.
For this purpose, we progressively conducted two case studies, two series of interviews, four iterations of action research, and an empirical study. The first case study was conducted in an avionics company to discover the challenges of using an agile process in a large scale safety critical project environment. Since requirements management was found to be one of the biggest challenges during the case study, we decided to investigate BDD because of its reputation for requirements management. The second case study was conducted in the company with an aim to discover the challenges of using BDD in real life. The case study was complemented with an empirical study of the practice of BDD in open source projects, taking a study sample from the GitHub open source collaboration site.
As a result of this Ph.D research, we were able to discover: (i) challenges of using an agile process in a large scale safety-critical organisation, (ii) current state of BDD in practice, (iii) technical limitations of Gherkin (i.e., the language for writing requirements in BDD), (iv) challenges of using BDD in a real project, (v) bad smells in the Gherkin specifications of open source projects on GitHub. We also presented a brief comparison between the theoretical description of BDD and BDD in practice. This research, therefore, presents the results of lessons learned from BDD in practice, and serves as a guide for software practitioners planning on using BDD in their projects
Posthuman Creative Styling can a creative writer’s style of writing be described as procedural?
This thesis is about creative styling — the styling a creative writer might use to make their writing
unique. It addresses the question as to whether such styling can be described as procedural. Creative
styling is part of the technique a creative writer uses when writing. It is how they make the text more
‘lively’ by use of tips and tricks they have either learned or discovered. In essence these are rules, ones
the writer accrues over time by their practice. The thesis argues that the use and invention of these
rules can be set as procedures. and so describe creative styling as procedural.
The thesis follows from questioning why it is that machines or algorithms have, so far, been
incapable of producing creative writing which has value. Machine-written novels do not abound on
the bookshelves and writing styled by computers is, on the whole, dull in comparison to human-crafted
literature. It came about by thinking how it would be possible to reach a point where writing by people
and procedural writing are considered to have equal value. For this reason the thesis is set in a
posthuman context, where the differences between machines and people are erased.
The thesis uses practice to inform an original conceptual space model, based on quality dimensions
and dynamic-inter operation of spaces. This model gives an example of the procedures which a
posthuman creative writer uses when engaged in creative styling. It suggests an original formulation
for the conceptual blending of conceptual spaces, based on the casting of qualities from one space to
another. In support of and informing its arguments are ninety-nine examples of creative writing
practice which show the procedures by which style has been applied, created and assessed. It provides
a route forward for further joint research into both computational and human-coded creative writing
Secrets Revealed in Container Images: An Internet-wide Study on Occurrence and Impact
Containerization allows bundling applications and their dependencies into a
single image. The containerization framework Docker eases the use of this
concept and enables sharing images publicly, gaining high momentum. However, it
can lead to users creating and sharing images that include private keys or API
secrets-either by mistake or out of negligence. This leakage impairs the
creator's security and that of everyone using the image. Yet, the extent of
this practice and how to counteract it remains unclear.
In this paper, we analyze 337,171 images from Docker Hub and 8,076 other
private registries unveiling that 8.5% of images indeed include secrets.
Specifically, we find 52,107 private keys and 3,158 leaked API secrets, both
opening a large attack surface, i.e., putting authentication and
confidentiality of privacy-sensitive data at stake and even allow active
attacks. We further document that those leaked keys are used in the wild: While
we discovered 1,060 certificates relying on compromised keys being issued by
public certificate authorities, based on further active Internet measurements,
we find 275,269 TLS and SSH hosts using leaked private keys for authentication.
To counteract this issue, we discuss how our methodology can be used to prevent
secret leakage and reuse.Comment: 15 pages, 7 figure
AI: Limits and Prospects of Artificial Intelligence
The emergence of artificial intelligence has triggered enthusiasm and promise of boundless opportunities as much as uncertainty about its limits. The contributions to this volume explore the limits of AI, describe the necessary conditions for its functionality, reveal its attendant technical and social problems, and present some existing and potential solutions. At the same time, the contributors highlight the societal and attending economic hopes and fears, utopias and dystopias that are associated with the current and future development of artificial intelligence
Control Flow Graph-based Path Reconstruction in Android applications
openOver the years, the field of Android security research has faced significant limitations due to the absence of reliable methods for achieving automated interaction with mobile applications. The lack of such tools has resulted in the widespread use of automatic exercising software, which randomly interfaces with apps in the hopes of obtaining desired outcomes. However, this approach cannot always be considered a satisfactory solution, as it lacks solid criteria and fails to provide any Proof-of-Reachability.
In the context of my thesis, I employed Control Flow Graphs to reconstruct pathways that lead to specified target methods within Android applications. This approach allowed me to extract high-level instructions that automatic interaction software can accurately and reliably execute in order to reach a designated endpoint.
Tests and evaluations conducted on this technique demonstrate its potential to facilitate more precise and goal-oriented testing. Its applications in the future could span from fuzzing and exploitation to aiding in the disclosure of privacy violations.Over the years, the field of Android security research has faced significant limitations due to the absence of reliable methods for achieving automated interaction with mobile applications. The lack of such tools has resulted in the widespread use of automatic exercising software, which randomly interfaces with apps in the hopes of obtaining desired outcomes. However, this approach cannot always be considered a satisfactory solution, as it lacks solid criteria and fails to provide any Proof-of-Reachability.
In the context of my thesis, I employed Control Flow Graphs to reconstruct pathways that lead to specified target methods within Android applications. This approach allowed me to extract high-level instructions that automatic interaction software can accurately and reliably execute in order to reach a designated endpoint.
Tests and evaluations conducted on this technique demonstrate its potential to facilitate more precise and goal-oriented testing. Its applications in the future could span from fuzzing and exploitation to aiding in the disclosure of privacy violations
Exploration of technical debt in start-ups
Context: Software start-ups are young companies aiming to build and market
software-intensive products fast with little resources. Aiming to accelerate
time-to-market, start-ups often opt for ad-hoc engineering practices, make
shortcuts in product engineering, and accumulate technical debt. Objective: In
this paper we explore to what extent precedents, dimensions and outcomes
associated with technical debt are prevalent in start-ups. Method: We apply a
case survey method to identify aspects of technical debt and contextual
information characterizing the engineering context in start-ups. Results: By
analyzing responses from 86 start-up cases we found that start-ups accumulate
most technical debt in the testing dimension, despite attempts to automate
testing. Furthermore, we found that start-up team size and experience is a
leading precedent for accumulating technical debt: larger teams face more
challenges in keeping the debt under control. Conclusions: This study
highlights the necessity to monitor levels of technical debt and to
preemptively introduce practices to keep the debt under control. Adding more
people to an already difficult to maintain product could amplify other
precedents, such as resource shortages, communication issues and negatively
affect decisions pertaining to the use of good engineering practices.Comment: ICSE-SEIP '18: Proceedings of the 40th International Conference on
Software Engineering: Software Engineering in Practic
A systematic literature review on source code similarity measurement and clone detection: techniques, applications, and challenges
Measuring and evaluating source code similarity is a fundamental software
engineering activity that embraces a broad range of applications, including but
not limited to code recommendation, duplicate code, plagiarism, malware, and
smell detection. This paper proposes a systematic literature review and
meta-analysis on code similarity measurement and evaluation techniques to shed
light on the existing approaches and their characteristics in different
applications. We initially found over 10000 articles by querying four digital
libraries and ended up with 136 primary studies in the field. The studies were
classified according to their methodology, programming languages, datasets,
tools, and applications. A deep investigation reveals 80 software tools,
working with eight different techniques on five application domains. Nearly 49%
of the tools work on Java programs and 37% support C and C++, while there is no
support for many programming languages. A noteworthy point was the existence of
12 datasets related to source code similarity measurement and duplicate codes,
of which only eight datasets were publicly accessible. The lack of reliable
datasets, empirical evaluations, hybrid methods, and focuses on multi-paradigm
languages are the main challenges in the field. Emerging applications of code
similarity measurement concentrate on the development phase in addition to the
maintenance.Comment: 49 pages, 10 figures, 6 table
The Influence of Neuroendocrine and Genetic Markers of Stress on Cognitive Processing and Intrusive Symptoms
This body of research investigated the influence of neuroendocrine and genetic elements of arousal on cognitive processes in the development of intrusive memories and flash-forward intrusions as related to Post-Traumatic Stress Disorder. Specifically, this thesis investigated various mechanisms that may underlie intrusive symptoms as postulated by prevalent theories of PTSD. Study 1 examined the distinctive relationship between peritraumatic dissociation and subsequent re-experiencing symptoms. Network analyses revealed strong positive edges between peritraumatic dissociation and subsequent amnesia, as well as the re-experiencing symptoms of physical reactivity to reminders, flashbacks, intrusions, and dreams, and to a lesser extent emotional numbness and hypervigilance. The finding that peritraumatic dissociation is related to subsequent re-experiencing symptoms is consistent with cognitive models that emphasize the role of dissociative experiences during a traumatic event in the etiology of PTSD re-experiencing symptoms. Study 2 aimed to determine whether peri-traumatic stress, as measured via salivary cortisol and salivary alpha-amylase, as well as pre-existing genetic polymorphisms on the FKBP5 gene increased dissociation and data-driven processing, and subsequently impacted intrusive memories related to a trauma film. The findings revealed that greater noradrenergic arousal predicted less intrusive memory distress in individuals who scored higher on data-driven processing and trait dissociation, and in FKBP5 low-risk carriers. For individuals who reported less data-driven processing and trait dissociation, and in FKBP5 high-risk carriers, as noradrenergic arousal increased, intrusive memory distress increased. This study also showed no association between data-driven processing with memory fragmentation, and fragmentation with intrusive memories. Whilst these findings support some aspect of cognitive models of PTSD as they indicate a role for data-driven processing and dissociation in intrusive symptoms, they highlight a threshold at which these variables stop moderating the relationship between arousal and intrusive memories and suggest that memory fragmentation is not related to intrusive memories. Study 3 examined the role of cognitive control in flash-forward intrusions in the context of an enduring stressor, the COVID-19 pandemic. In line with expectations, results showed that as cognitive control worsened, FKBP5 high-risk carriers reported more flash-forward distress, and low-risk carriers reported less distress. These findings are considered in the context of hippocampal changes and are consistent with emerging theories of PTSD. Lastly, study 4 sought to investigate the role of two neurological processes, pattern separation and pattern completion in intrusive memories in individuals with PTSD compared to trauma exposed controls. Consistent with existing literature, the data indicate that individuals with PTSD reported more data-driven processing, more intrusive symptoms, and demonstrated better behavioural pattern completion than trauma-exposed controls. These findings are in line with current cognitive models of PTSD, as they again indicate a role for data-driven processing in PTSD. However, study 4 found no support for the postulate that deficient pattern separation is a feature of PTSD and found an opposite effect for the role of pattern completion. Whilst these findings are inconsistent with theory, they are in line with existing experimental studies. Overall, the findings from this thesis provide insight into cognitive and biological models of PTSD and shed light on the mechanisms underlying the nature and development of intrusive symptoms
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