1,032 research outputs found
Participatory approach for integrated basin planning with focus on disaster risk reduction : the case of the Limpopo river
This paper defends the idea that a participatory approach is a suitable method for basin planning integrating both water and land aspects. Assertions made are based on scientific literature review and corroborated by field experience and research carried out in the Limpopo River basin, a transboundary river located in southern Africa which is affected by periodical floods. The paper explains how a basin strategic plan can be drafted and disaster risk reduction strategies derived by combining different types of activities using a bottom-up approach, despite an institutional context which operates through traditional top-down mechanisms. In particular, the "Living with Floods" experience in the lower Limpopo River, in Mozambique, is described as a concrete example of a disaster adaptation measure resulting from a participatory planning exercise. In conclusion, the adopted method and obtained results are discussed and recommendations are formulated for potential replication in similar contexts of the developing world
Atmospheric dynamics and the mass loss process in red supergiant stars
Red supergiant stars represent a key phase in the evolution of massive stars.
Recent radiative hydrodynamic simulations suggest that their atmospheres may be
the location of large-scale convective motions. As supergiant convection is
expected to generate supersonic motions and shocks, we seek constraints on
these atmospheric motions and their possible relation with mass-loss rates. We
present high-resolution, visible spectroscopy of a sample of red supergiants
(spectral type M I) and analyse them with a tomographic technique. We observe
steep velocity gradients, characterising both upward and downward supersonic
motions, which are time variable on time scales of a few hundred days. These
convective motions will generate turbulent pressure, which will strongly
decrease the effective gravity. We suggest that this decrease, combined with
radiative pressure on molecular lines, initiate the mass loss in red supergiant
stars.Comment: Accepted by Astronomy and Astrophysics. 12 pages, 14 figure
Neurovisceral phenotypes in the expression of psychiatric symptoms
This review explores the proposal that vulnerability to psychological symptoms, particularly anxiety, originates in constitutional differences in the control of bodily state, exemplified by a set of conditions that include Joint Hypermobility, Postural Tachycardia Syndrome and Vasovagal Syncope. Research is revealing how brainbody mechanisms underlie individual differences in psychophysiological reactivity that can be important for predicting, stratifying and treating individuals with anxiety disorders and related conditions. One common constitutional difference is Joint Hypermobility, in which there is an increased range of joint movement as a result of a variant of collagen. Joint hypermobility is over-represented in people with anxiety, mood and neurodevelopmental disorders. It is also linked to stress-sensitive medical conditions such as irritable bowel syndrome, chronic fatigue syndrome and fibromyalgia. Structural differences in 'emotional' brain regions are reported in hypermobile individuals, and many people with joint hypermobility manifest autonomic abnormalities, typically Postural Tachycardia Syndrome. Enhanced heart rate reactivity during postural change and as recently recognised factors causing vasodilatation (as noted post prandially, post exertion and with heat) is characteristic of Postural Tachycardia Syndrome, and there is a phenomenological overlap with anxiety disorders, which may be partially accounted for by exaggerated neural reactivity within ventromedial prefrontal cortex. People who experience Vasovagal Syncope, a heritable tendency to fainting induced by emotional challenges (and needle/blood phobia), are also more vulnerable to anxiety disorders. Neuroimaging implicates brainstem differences in vulnerability to faints, yet the structural integrity of the caudate nucleus appears important for the control of fainting frequency in relation to parasympathetic tone and anxiety. Together there is clinical and neuroanatomical evidence to show that common constitutional differences affecting autonomic responsivity are linked to psychiatric symptoms, notably anxiety
Atmospheric Abundances in Post-AGB candidates of Intermediate Temperature
Detailed atmospheric abundances have been calculated for a sample of A-G
supergiant stars with IR fluxes and/or high galactic latitudes. HD 172481 and
HD 158616 show clear indications of being post-AGB stars that have experienced
third dredge-up. HD 158616 is carbon-rich while the abundance pattern of HD
172481 and its large Li enhancement gives support to the hot bottom burning
scenario that explains paucity of carbon-rich stars among AGB stars. HD 172324
is very likely a hot post-AGB star that shows a strong carbon deficiency. HD
725, HD 218753 and HD 331319 also appear to be evolved objects between the red
giant and the AGB. HD 9167, HD 173638 with a few exceptions, reflect solar
abundances and no signs of post red giant evolution. They are most likely young
massive disk supergiants. Further analysis of proto-Planetary Nebula HDE 341617
reveals that He lines show signs of velocity stratification. The emission lines
have weakened considerably since 1993. The envelope expands at 19 km s
relative to the star. Atmospheric abundances, evolutionary tracks and
isochrones are used to estimate masses and ages of all stars in the sample.Comment: 19 pages (text), 14 tables, 5 figure
Flood analysis of the Limpopo River basin through past evolution reconstruction and a geomorphological approach
This research reconstructs the past evolution of the Limpopo River, a transboundary system located in southeastern Africa, and describes its geomorphological settings through a literature review and field work activities, with the aim of analysing flood hazard in the basin. Major changes have occurred since the late Jurassic-early Cretaceous period due to successive tectonic events. The paper demonstrates that the apparently abandoned drainage conformation of the palaeo-Limpopo in the upper and middle stretches of the river today constitutes preferential flood-prone areas in the case of major rainfall events. An important palaeo-delta is identified in the lower Limpopo, which imposes a particular drainage pattern onto the floodplain in Mozambique and influences the flood dynamics at present. The adopted method is helpful in determining flood hazard in a data-scarce area showing complex fluvial dynamics, and allows for the identification of unsuitable locations for human settlements
What do young adolescents think about taking part in longitudinal self-harm research?: findings from a school-based study
Background: Research about self-harm in adolescence is important given the high incidence in youth, and strong links to suicide and other poor outcomes. Clarifying the impact of involvement in school based self-harm studies on young adolescents is an ethical priority given heightened risk at this developmental stage. Methods: Here, 594 school-based students aged mainly 13-14 years completed a survey on self-harm at baseline and again 12-weeks later. Change in mood following completion of each survey, ratings and thoughts about participation, and responses to a mood-mitigation activity were analysed using a multi-method approach. Results: Baseline participation had no overall impact on mood. However, boys and girls reacted differently to the survey depending on self-harm status. Having a history of self-harm had a negative impact on mood for girls, but a positive impact on mood for boys. In addition, participants rated the survey in mainly positive/neutral terms, and cited benefits including personal insight and altruism. At follow-up, there was a negative impact on mood following participation, but no significant effect of gender or self-harm status. Ratings at follow-up were mainly positive/neutral. Those who had self-harmed reported more positive and fewer negative ratings than at baseline: the opposite pattern of response was found for those who had not self-harmed. Mood mitigation activities were endorsed. Conclusions: Self-harm research with youth is feasible in school settings. Most young people are happy to take part and cite important benefits. However, the impact of participation in research appears to vary according to gender, self-harm risk and method/time of assessment. The impact of repeated assessment requires clarification. Simple mood-elevation techniques may usefully help to mitigate distress
Assessing the Security of Internal Automotive Networks
Context In order to address the growing need for connectivity in today’s cars, the
in-vehicle network has increased in complexity, now consisting of over 100 electrical
control units. Balancing the level of security with high performance is non-trivial,
and current networks have shown to sacrifice security measures for performance,
therefore leaving the networks sensitive to both manipulation and information re trieval.
Objective The first objective of this thesis was to assess the security of in-vehicle
networks and identify potential security threats that may be exercised with commodity hardware and without expert knowledge in vehicular networking. Secondly,
propose solutions to identified security vulnerabilities that act as a defence against
the exercised attacks.
Method The project was executed with the Design Science Research methodology, where an artefact is developed and evaluated through iterations. The artefact
consists of commodity hardware and open software as well as our approach to simulate an attack of an uninitiated tamperer. The applying artefact was evaluated by
testing it on vehicle test beds. The evaluation was also the basis for the assessment
and in extension the proposed solutions.
Results The in-vehicle network was susceptible to multiple attacks such as Man in-the-middle and Replay attacks. For instance, multiple components in the network
were successfully manipulated through replay attacks on the network. The replay attacks were conducted in combination with a minimization algorithm which enabled
reverse engineering of specific functions with high precision. This made it possible
to not only take full control but to block user input. Moreover, Man-in-the-middle
attacks on the Ethernet traffic yielded raw data indicating a lack of encryption and
also enabled us to map the network topology. To resolve the aforementioned issues,
this thesis proposes solutions at varying security levels that would have prevented
our attacks; such as CAN bus message counters, MACsec for low-level protection
against sniffing and TLS encryption for the confidentiality of raw data.
Conclusions The project has shown that it is indeed possible to extract and
manipulate data even with the limitations enforced in this project. In addition, it
showed that the tested in-vehicle networks lack resilience against unauthorized access
and manipulation. The proposed solutions protect against exercised attacks but are
subject to future research in terms of implementation and overhead measurements
Constraining the wind launching region in Herbig Ae stars: AMBER/VLTI spectroscopy of HD 104237
Astronomy and Astrophysics, 464, pp. 55-58, http://dx.doi.org./10.1051/0004-6361:20065719International audienc
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