832 research outputs found
Blood pressure control among hypertensive subjects in Dutse, Northwestern Nigeria
Background: High blood pressure is an independent risk factor for cerebrovascular, renal and cardiovascular disease. According to World Health Organization treatment to target Blood Pressure (BP) of <140/90 mmHg has been associated with decrease in morbidity and mortality. Despite this BP control has been very poor even in developed economies.Objective: We set to assess level of BP control among hypertensive patients on treatment in Dutse, Jigawa state, and to identify treatable causes of failure to achieve target for better management.Methods: It is a cross sectional study of all hypertensives for more than one year attending medical out patients clinic who have consented. An interviewer administered questionnaire was used to obtain information from the patients.Results: A total of 123 patients of which 45% were females with mean age, duration of hypertension of 51.9 and 5.9 years respectively and BMI of 40.9Kg/m2. Eighty-three per cent, 91% and 94% were aware of salt restriction, cessation of smoking and alcohol moderation as lifestyle modifications respectively. The mean Systolic and Diastolic BP were 142mmHg and 86mmHg respectively. Fifty-two per cent were on two drugs combination including a diuretic while 4.87% were on three drugs or more. Less than a third (27.6%) had their BP controlled at <140/90mmHg. There was no significant difference in the demographic and clinical data between patients with controlled and uncontrolled BP.Conclusion: This study found that control of BP is still poor in our setting. This could be due to physician inertia in the treatment, use of inappropriate combination of anti hypertensives or failure to reinforce lifestyle modifications.Keywords: Blood pressure, Hypertensives, Control, Black
Excavations at Site C North, Kalambo Falls, Zambia:New insights into the mode 2/3 Transition in South-Central Africa
We report on the results of small-scale excavations at the archaeological site of Kalambo Falls, northern Zambia. The site has long been known for its stratified succession of Stone Age horizons, in particular those representing the late Acheulean (Mode 2) and early Middle Stone Age (Mode 3). Previous efforts to date these horizons have provided, at best, minimum radiometric ages. The absence of a firm chronology for the site has limited its potential contribution to our understanding of the process of technological change in the Middle Pleistocene of
south-central Africa. The aim of the excavations was to collect samples for luminescence dating that bracketed archaeological horizons, and to establish the sedimentary and palaeoenvironmental contexts of the deposits. Four sedimentary packages were identified with the oldest containing Mode 2 and Mode 3 horizons. In this paper we consider the implications of the luminescence ages for the archaeological record at Kalambo Falls, and place them in a regional context. The reworking and preservation of the archaeological horizons is interpreted as the result of successive phases of meander migration and aggradation.
Limited pollen evidence suggests a persistent floodplain
palaeoenvironment with intermittent swamp forest and adjacent valley woodland, while mineral magnetic susceptibility data support an interpretation of river flow variability without any significant change in sediment provenance. The dynamics of the fluvial system cannot as yet be linked directly with regional climate change. The age range of ~500–300 ka for the oldest sedimentary package places the Mode 2/3 succession firmly in the Middle Pleistocene, and contributes to an expanding African record of technological innovation before the evolution
of Homo sapiens
Electron spin resonance dating of quartz from archaeological sites at Victoria Falls, Zambia
When electron spin resonance (ESR) is applied to sedimentary quartz, dealing with the poor bleachability of the signals is particularly challenging. In this study, we used both the single-grain optically stimulated luminescence (OSL) and the single aliquot ESR dating of quartz from deep sand deposits preserving a Stone Age archaeological sequence to combine the advantages of the two methods: good bleaching behaviour and extended age range. Using the youngest samples at each sampling site we were able to calculate the mean ESR residual age from the difference between the OSL ages and the apparent ESR ages. Focusing mainly on the single aliquot regenerative dose (SAR) protocol here, we were able to calculate the mean ESR residual age for the Ti and Al centres, including the non-bleachable signal component for the latter. For the NP site, residual ages of 209 ± 13 ka and 695 ± 23 ka were calculated for the two centres, whereas for the ZS site 268 ± 39 ka and 742 ± 118 ka were determined. These residual ages are significant and cannot be neglected. Thus, the residual age was subtracted from the apparent ESR ages. The validity of the residual subtraction method was tested through a comparison of the oldest OSL age from each site with the residual subtracted ESR age. For both NP and ZS sites, the residual subtracted Ti and Al ages were consistent with the OSL age within 2-σ uncertainty, and therefore confirm the robustness of the subtraction method. Within the NP sequence, we were able to locate the end of the Early Stone Age at 590 ± 86 ka, and this provides a maximum age for the transition to the Middle Stone Age in this part of south-central Africa
Strongly interacting Fermi gases
Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision measurements on the thermodynamics of a strongly interacting Fermi gas across the superfluid transition. The onset of superfluidity is directly observed in the compressibility, the chemical potential, the entropy, and the heat capacity. Our measurements provide benchmarks for current many-body theories on strongly interacting fermions. Secondly, we have studied the evolution of fermion pairing from three to two dimensions in these gases, relating to the physics of layered superconductors. In the presence of p-wave interactions, Fermi gases are predicted to display toplogical superfluidity carrying Majorana edge states. Two possible avenues in this direction are discussed, our creation and direct observation of spin-orbit coupling in Fermi gases and the creation of fermionic molecules of [superscript 23]Na [superscript 40]K that will feature strong dipolar interactions in their absolute ground state
Poverty and the multiple stakeholder challenge for global leaders
The article presents a case study in which business leaders deal with challenging problems related to poverty, involving multiple stakeholders. This emphasizes the importance of training prospective global leaders to manage stakeholder relationships and engage in stakeholder dialogue. The authors highlight the stakeholder role played by nongovernmental organizations and include a simulation that develops stakeholder dialogue skills. They identify practical lessons and assumptions underlying business education that are not shared by all stakeholders in the context of poverty
Observing Supermassive Black Holes across cosmic time: from phenomenology to physics
In the last decade, a combination of high sensitivity, high spatial
resolution observations and of coordinated multi-wavelength surveys has
revolutionized our view of extra-galactic black hole (BH) astrophysics. We now
know that supermassive black holes reside in the nuclei of almost every galaxy,
grow over cosmological times by accreting matter, interact and merge with each
other, and in the process liberate enormous amounts of energy that influence
dramatically the evolution of the surrounding gas and stars, providing a
powerful self-regulatory mechanism for galaxy formation. The different
energetic phenomena associated to growing black holes and Active Galactic
Nuclei (AGN), their cosmological evolution and the observational techniques
used to unveil them, are the subject of this chapter. In particular, I will
focus my attention on the connection between the theory of high-energy
astrophysical processes giving rise to the observed emission in AGN, the
observable imprints they leave at different wavelengths, and the methods used
to uncover them in a statistically robust way. I will show how such a combined
effort of theorists and observers have led us to unveil most of the SMBH growth
over a large fraction of the age of the Universe, but that nagging
uncertainties remain, preventing us from fully understating the exact role of
black holes in the complex process of galaxy and large-scale structure
formation, assembly and evolution.Comment: 46 pages, 21 figures. This review article appears as a chapter in the
book: "Astrophysical Black Holes", Haardt, F., Gorini, V., Moschella, U and
Treves A. (Eds), 2015, Springer International Publishing AG, Cha
UHECR as Decay Products of Heavy Relics? The Lifetime Problem
The essential features underlying the top-down scenarii for UHECR are
discussed, namely, the stability (or lifetime) imposed to the heavy objects
(particles) whatever they be: topological and non-topological solitons,
X-particles, cosmic defects, microscopic black-holes, fundamental strings. We
provide an unified formula for the quantum decay rate of all these objects as
well as the particle decays in the standard model. The key point in the
top-down scenarii is the necessity to adjust the lifetime of the heavy object
to the age of the universe. This ad-hoc requirement needs a very high
dimensional operator to govern its decay and/or an extremely small coupling
constant. The natural lifetimes of such heavy objects are, however, microscopic
times associated to the GUT energy scale (sim 10^{-28} sec. or shorter). It is
at this energy scale (by the end of inflation) where they could have been
abundantly formed in the early universe and it seems natural that they decayed
shortly after being formed.Comment: 11 pages, LaTex, no figures, updated versio
Stakeholder Engagement in Sustainability Reporting: Evidence of Reputation Risk Management in Large Australian Companies
The objective of this research is to examine whether stakeholder engagement in sustainability reporting constitutes the process of managing reputation risks. This research utilises Shrives and Brennan’s (2017) framework of rhetorical strategies of non-compliance to obtain empirical evidence of reputation risk management in the context of stakeholder engagement in sustainability reporting. Quantitative and qualitative methods of content analysis were undertaken on 154 sustainability disclosures in both annual reports and sustainability reports of large Australian companies. This research finds that large Australian companies engage with their stakeholders to manage reputation risks: to increase market share and pre-empt social issues. It is evident that large Australian companies use several forms of rhetorical statements in their sustainability disclosures with respect to reputation risk management efforts. However, there is no evidence that they shirk responsibilities
Size Doesn't Matter: Towards a More Inclusive Philosophy of Biology
notes: As the primary author, O’Malley drafted the paper, and gathered and analysed data (scientific papers and talks). Conceptual analysis was conducted by both authors.publication-status: Publishedtypes: ArticlePhilosophers of biology, along with everyone else, generally perceive life to fall into two broad categories, the microbes and macrobes, and then pay most of their attention to the latter. ‘Macrobe’ is the word we propose for larger life forms, and we use it as part of an argument for microbial equality. We suggest that taking more notice of microbes – the dominant life form on the planet, both now and throughout evolutionary history – will transform some of the philosophy of biology’s standard ideas on ontology, evolution, taxonomy and biodiversity. We set out a number of recent developments in microbiology – including biofilm formation, chemotaxis, quorum sensing and gene transfer – that highlight microbial capacities for cooperation and communication and break down conventional thinking that microbes are solely or primarily single-celled organisms. These insights also bring new perspectives to the levels of selection debate, as well as to discussions of the evolution and nature of multicellularity, and to neo-Darwinian understandings of evolutionary mechanisms. We show how these revisions lead to further complications for microbial classification and the philosophies of systematics and biodiversity. Incorporating microbial insights into the philosophy of biology will challenge many of its assumptions, but also give greater scope and depth to its investigations
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