135 research outputs found
Liquid-like behavior of supercritical fluids
The high frequency dynamics of fluid oxygen have been investigated by
Inelastic X-ray Scattering. In spite of the markedly supercritical conditions
(, ), the sound velocity exceeds the hydrodynamic
value of about 20%, a feature which is the fingerprint of liquid-like dynamics.
The comparison of the present results with literature data obtained in several
fluids allow us to identify the extrapolation of the liquid vapor-coexistence
line in the (, ) plane as the relevant edge between liquid- and
gas-like dynamics. More interestingly, this extrapolation is very close to the
non metal-metal transition in hot dense fluids, at pressure and temperature
values as obtained by shock wave experiments. This result points to the
existence of a connection between structural modifications and transport
properties in dense fluids.Comment: 4 pages, 3 figures, accepted by Phys. Rev. Let
In-hospital safety in field conditions of Nifurtimox Eflornithine Combination Therapy (NECT) for T. B. Gambiense Sleeping Sickness
Trypanosoma brucei (T.b.) gambiense Human African trypanosomiasis (HAT; sleeping sickness) is a fatal disease. Until 2009, available treatments for 2(nd) stage HAT were complicated to use, expensive (eflornithine monotherapy), or toxic, and insufficiently effective in certain areas (melarsoprol). Recently, nifurtimox-eflornithine combination therapy (NECT) demonstrated good safety and efficacy in a randomised controlled trial (RCT) and was added to the World Health Organisation (WHO) essential medicines list (EML). Documentation of its safety profile in field conditions will support its wider use
Conflict, collusion and corruption in small-scale gold mining: Chinese miners and the state in Ghana
A Perspective on Future Research Directions in Information Theory
Information theory is rapidly approaching its 70th birthday. What are
promising future directions for research in information theory? Where will
information theory be having the most impact in 10-20 years? What new and
emerging areas are ripe for the most impact, of the sort that information
theory has had on the telecommunications industry over the last 60 years? How
should the IEEE Information Theory Society promote high-risk new research
directions and broaden the reach of information theory, while continuing to be
true to its ideals and insisting on the intellectual rigor that makes its
breakthroughs so powerful? These are some of the questions that an ad hoc
committee (composed of the present authors) explored over the past two years.
We have discussed and debated these questions, and solicited detailed inputs
from experts in fields including genomics, biology, economics, and
neuroscience. This report is the result of these discussions
Opposite Incidence Trends for Differentiated and Medullary Thyroid Cancer in Young Dutch Patients over a 30-Year Time Span (vol 13, 5104, 2021)
Error in Figure In the original article [1], there was a mistake in Figure 1 as published. In this figure, two years are missing (2000 and 2001). The AAPC values as previously published are correct. The corrected Figure 1 appears below. In addition, in the original article, there was a mistake in Figure 2A–C as published. In these figures, two years are missing (2000 and 2001). The AAPC values were correct and do not require adjustment. The corrected Figure 2A–C appears below. The authors apologize for any inconvenience caused and state that the scientific conclusions are unaffected. The original article has been updated. (figure presented)
Clientelism as civil society? Unpacking the relationship between clientelism and democracy at the local level in South Africa
This article, building on analyses from the global south, attempts to reframe democratic expectations by considering where previously maligned practices such as clientelism may hold moments of democracy. It does so by comparing the theory of civil society with that of clientelism, and its African counterpart neo-patrimonialism. It argues that clientelism as civil society may fulfil democratic tasks such as holding the (local) state accountable, strengthening civil and political liberties and providing channels of access for previously marginalised groups. Clientelism is not necessarily a reflection of imposed power relations but, at times, can demonstrate a conscious political strategy, to generate development, on the part of its protagonists.IS
Partnering to proceed: scaling up adolescent sexual reproductive health programmes in Tanzania. Operational research into the factors that influenced local government uptake and implementation
BACKGROUND: Little is known about how to implement promising small-scale projects to reduce reproductive ill health and HIV vulnerability in young people on a large scale. This evaluation documents and explains how a partnership between a non-governmental organization (NGO) and local government authorities (LGAs) influenced the LGA-led scale-up of an innovative NGO programme in the wider context of a new national multisectoral AIDS strategy. METHODS: Four rounds of semi-structured interviews with 82 key informants, 8 group discussions with 49 district trainers and supervisors (DTS), 8 participatory workshops involving 52 DTS, and participant observations of 80% of LGA-led and 100% of NGO-led meetings were conducted, to ascertain views on project components, flow of communication and decision-making and amount of time DTS utilized undertaking project activities. RESULTS: Despite a successful ten-fold scale-up of intervention activities in three years, full integration into LGA systems did not materialize. LGAs contributed significant human resources but limited finances; the NGO retained control over finances and decision-making and LGAs largely continued to view activities as NGO driven. Embedding of technical assistants (TAs) in the LGAs contributed to capacity building among district implementers, but may paradoxically have hindered project integration, because TAs were unable to effectively transition from an implementing to a facilitating role. Operation of NGO administration and financial mechanisms also hindered integration into district systems. CONCLUSIONS: Sustainable intervention scale-up requires operational, financial and psychological integration into local government mechanisms. This must include substantial time for district systems to try out implementation with only minimal NGO support and modest output targets. It must therefore go beyond the typical three- to four-year project cycles. Scale-up of NGO pilot projects of this nature also need NGOs to be flexible enough to adapt to local government planning cycles and ongoing evaluation is needed to ensure strategies employed to do so really do achieve full intervention integration
Як уникнути підйому рівня води?
East Africa’s Lake Victoria provides resources and services to millions of people on the lake’s shores and abroad. In particular, the lake’s fisheries are an important source of protein, employment, and international economic connections for the whole region. Nonetheless, stock dynamics are poorly understood and currently unpredictable. Furthermore, fishery dynamics are intricately connected to other supporting services of the lake as well as to lakeshore societies and economies. Much research has been carried out piecemeal on different aspects of Lake Victoria’s system; e.g., societies, biodiversity, fisheries, and eutrophication. However, to disentangle drivers and dynamics of change in this complex system, we need to put these pieces together and analyze the system as a whole. We did so by first building a qualitative model of the lake’s social-ecological system. We then investigated the model system through a qualitative loop analysis, and finally examined effects of changes on the system state and structure. The model and its contextual analysis allowed us to investigate system-wide chain reactions resulting from disturbances. Importantly, we built a tool that can be used to analyze the cascading effects of management options and establish the requirements for their success. We found that high connectedness of the system at the exploitation level, through fisheries having multiple target stocks, can increase the stocks’ vulnerability to exploitation but reduce society’s vulnerability to variability in individual stocks. We describe how there are multiple pathways to any change in the system, which makes it difficult to identify the root cause of changes but also broadens the management toolkit. Also, we illustrate how nutrient enrichment is not a self-regulating process, and that explicit management is necessary to halt or reverse eutrophication. This model is simple and usable to assess system-wide effects of management policies, and can serve as a paving stone for future quantitative analyses of system dynamics at local scales
Orbital and dynamical analysis of the system around HR 8799. New astrometric epochs from VLT/SPHERE and LBT/LUCI
HR\,8799 is a young planetary system composed of 4 planets and a double
debris belt. Being the first multi-planetary system discovered with the direct
imaging technique, it has been observed extensively since 1998. This wide
baseline of astrometric measurements, counting over 50 observations in 20
years, permits a detailed orbital and dynamical analysis of the system. To
explore the orbital parameters of the planets, their dynamical history, and the
planet-to-disk interaction, we made follow-up observations of the system during
the VLT/SPHERE GTO program. We obtained 21 observations, most of them in
favorable conditions. In addition, we observed HR\,8799 with the instrument
LBT/LUCI. All the observations were reduced with state-of-the-art algorithms
implemented to apply the spectral and angular differential imaging method. We
re-reduced the SPHERE data obtained during the commissioning of the instrument
and in 3 open-time programs to have homogeneous astrometry. The precise
position of the 4 planets with respect to the host star was calculated by
exploiting the fake negative companions method. To improve the orbital fitting,
we also took into account all of the astrometric data available in the
literature. From the photometric measurements obtained in different
wavelengths, we estimated the planets' masses following the evolutionary
models. We obtained updated parameters for the orbits with the assumption of
coplanarity, relatively small eccentricities, and periods very close to the 2:1
resonance. We also refined the dynamical mass of each planet and the parallax
of the system (24.49 0.07 mas). We also conducted detailed -body
simulations indicating possible positions of a~putative fifth innermost planet
with a mass below the present detection limits of ~\MJup.Comment: 27 pages, 15 figures, A&A in pres
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