An affordable, quality-assured community-based system for high-resolution entomological surveillance of vector mosquitoes that reflects human malaria infection risk patterns.

ABSTRACT: BACKGROUND: More sensitive and scalable entomological surveillance tools are required to monitor low levels of transmission that are increasingly common across the tropics, particularly where vector control has been successful. A large-scale larviciding programme in urban Dar es Salaam, Tanzania is supported by a community-based (CB) system for trapping adult mosquito densities to monitor programme performance. Methodology An intensive and extensive CB system for routine, longitudinal, programmatic surveillance of malaria vectors and other mosquitoes using the Ifakara Tent Trap (ITT-C) was developed in Urban Dar es Salaam, Tanzania, and validated by comparison with quality assurance (QA) surveys using either ITT-C or human landing catches (HLC), as well as a cross-sectional survey of malaria parasite prevalence in the same housing compounds. RESULTS: Community-based ITT-C had much lower sensitivity per person-night of sampling than HLC (Relative Rate (RR) [95% Confidence Interval (CI)] = 0.079 [0.051, 0.121], P < 0.001 for Anopheles gambiae s.l. and 0.153 [0.137, 0.171], P < 0.001 for Culicines) but only moderately differed from QA surveys with the same trap (0.536 [0.406,0.617], P = 0.001 and 0.747 [0.677,0.824], P < 0.001, for An. gambiae or Culex respectively). Despite the poor sensitivity of the ITT per night of sampling, when CB-ITT was compared with QA-HLC, it proved at least comparably sensitive in absolute terms (171 versus 169 primary vectors caught) and cost-effective (153US$versus 187US$ per An. gambiae caught) because it allowed more spatially extensive and temporally intensive sampling (4284 versus 335 trap nights distributed over 615 versus 240 locations with a mean number of samples per year of 143 versus 141). Despite the very low vectors densities (Annual estimate of about 170 An gambiae s.l bites per person per year), CB-ITT was the only entomological predictor of parasite infection risk (Odds Ratio [95% CI] = 4.43[3.027,7. 454] per An. gambiae or Anopheles funestus caught per night, P =0.0373). Discussion and conclusion CB trapping approaches could be improved with more sensitive traps, but already offer a practical, safe and affordable system for routine programmatic mosquito surveillance and clusters could be distributed across entire countries by adapting the sample submission and quality assurance procedures accordingly

Phytochemical Screening and Antimicrobial Studies of Crateva adansonii Leaf Extract

Diverse challenges of microbial infections and upsurge of multi-drug resistant microbes informed the investigation into the phytochemical and antibacterial properties of Crateva adansonii. Cold extraction was carried out using methanol solvent. The crude extract of Crateva adansonii was fractionated into the n-hexane, methanol and chloroform layers successively. The phytochemical screening indicated the presence of alkaloids, saponins, terpenoids, flavonoids and cardiac glycosides. The antimicrobial assay showed that, for Bacillus spp, the organism was sensitive to the chloroform fraction of leaf extract at 1.562 mg/ml. For Microccocus varians, result showed organism was sensitive to the crude extract at 3.125 mg/ml. According to the result of antifungal screening, the n-hexane fraction and crude extract showed activity against Aspergillus niger at 12.500 mg/ml and 3.125 mg/ml respectively. From these results, the crude extract of the leaf of Crateva adansonii shows activity against both bacteria and Fungi; hence, it may might be a good source of new drug for treating infections caused by these pathogen

"Even if the test result is negative, they should be able to tell us what is wrong with us": a qualitative study of patient expectations of rapid diagnostic tests for malaria.

BACKGROUND: The debate on rapid diagnostic tests (RDTs) for malaria has begun to shift from whether RDTs should be used, to how and under what circumstances their use can be optimized. This has increased the need for a better understanding of the complexities surrounding the role of RDTs in appropriate treatment of fever. Studies have focused on clinician practices, but few have sought to understand patient perspectives, beyond notions of acceptability. METHODS: This qualitative study aimed to explore patient and caregiver perceptions and experiences of RDTs following a trial to assess the introduction of the tests into routine clinical care at four health facilities in one district in Ghana. Six focus group discussions and one in-depth interview were carried out with those who had received an RDT with a negative test result. RESULTS: Patients had high expectations of RDTs. They welcomed the tests as aiding clinical diagnoses and as tools that could communicate their problem better than they could, verbally. However, respondents also believed the tests could identify any cause of illness, beyond malaria. Experiences of patients suggested that RDTs were adopted into an existing system where patients are both physically and intellectually removed from diagnostic processes and where clinicians retain authority that supersedes tests and their results. In this situation, patients did not feel able to articulate a demand for test-driven diagnosis. CONCLUSIONS: Improvements in communication between the health worker and patient, particularly to explain the capabilities of the test and management of RDT negative cases, may both manage patient expectations and promote patient demand for test-driven diagnoses

a review

It is well documented that global warming is unequivocal. Dairy production systems are considered as important sources of greenhouse gas emissions; however, little is known about the sensitivity and vulnerability of these production systems themselves to climate warming. This review brings different aspects of dairy cow production in Central Europe into focus, with a holistic approach to emphasize potential future consequences and challenges arising from climate change. With the current understanding of the effects of climate change, it is expected that yield of forage per hectare will be influenced positively, whereas quality will mainly depend on water availability and soil characteristics. Thus, the botanical composition of future grassland should include species that are able to withstand the changing conditions (e.g. lucerne and bird's foot trefoil). Changes in nutrient concentration of forage plants, elevated heat loads and altered feeding patterns of animals may influence rumen physiology. Several promising nutritional strategies are available to lower potential negative impacts of climate change on dairy cow nutrition and performance. Adjustment of feeding and drinking regimes, diet composition and additive supplementation can contribute to the maintenance of adequate dairy cow nutrition and performance. Provision of adequate shade and cooling will reduce the direct effects of heat stress. As estimated genetic parameters are promising, heat stress tolerance as a functional trait may be included into breeding programmes. Indirect effects of global warming on the health and welfare of animals seem to be more complicated and thus are less predictable. As the epidemiology of certain gastrointestinal nematodes and liver fluke is favourably influenced by increased temperature and humidity, relations between climate change and disease dynamics should be followed closely. Under current conditions, climate change associated economic impacts are estimated to be neutral if some form of adaptation is integrated. Therefore, it is essential to establish and adopt mitigation strategies covering available tools from management, nutrition, health and plant and animal breeding to cope with the future consequences of climate change on dairy farming

Extraordinarily complex crystal structure with mesoscopic patterning in barium at high pressure

Elemental barium adopts a series of high-pressure phases with such complex crystal structures that some of them have eluded structure determination for many years. Using single-crystal synchrotron X-ray diffraction and new data analysis strategies, we have now solved the most complex of these crystal structures, that of phase Ba-IVc at 19 GPa. It is a commensurate host–guest structure with 768 atoms in the representative unit, where the relative alignment of the guest-atom chains can be represented as a two-dimensional pattern with interlocking S-shaped 12-chain motifs repeating regularly in one direction and repeating with constrained disorder in the other. The existence of such patterning on the nanometre scale points at medium-range interactions that are not fully screened by the itinerant electrons in this metal. On the basis of first-principles electronic structure calculations, pseudopotential theory and an analysis of the lattice periodicities and interatomic distances, we rationalize why the Ba phases with the common densely packed crystal structures become energetically unfavourable in comparison with the complex-structured Ba-IVc phase, and what the role of the well-known pressure-induced s–d electronic transfer is

Some implications of superconducting quantum interference to the application of master equations in engineering quantum technologies

In this paper we consider the modeling and simulation of open quantum systems from a device engineering perspective. We derive master equations at different levels of approximation for a superconducting quantum interference device (SQUID) ring coupled to an ohmic bath. We demonstrate that the master equations we consider produce decoherences that are qualitatively and quantitatively dependent on both the level of approximation and the ring's external flux bias. We discuss the issues raised when seeking to obtain Lindbladian dissipation and show, in this case, that the external flux (which may be considered to be a control variable in some applications) is not confined to the Hamiltonian, as often assumed in quantum control, but also appears in the Lindblad terms

Threshold Laws for the Break-up of Atomic Particles into Several Charged Fragments

The processes with three or more charged particles in the final state exhibit particular threshold behavior, as inferred by the famous Wannier law for (2e + ion) system. We formulate a general solution which determines the threshold behavior of the cross section for multiple fragmentation. Applications to several systems of particular importance with three, four and five leptons (electrons and positrons) in the field of charged core; and two pairs of identical particles with opposite charges are presented. New threshold exponents for these systems are predicted, while some previously suggested threshold laws are revised.Comment: 40 pages, Revtex, scheduled for the July issue of Phys.Rev.A (1998

Reconstruction and control of a time-dependent two-electron wave packet

The concerted motion of two or more bound electrons governs atomic1 and molecular2,3 non-equilibrium processes including chemical reactions, and hence there is much interest in developing a detailed understanding of such electron dynamics in the quantum regime. However, there is no exact solution for the quantumthree-body problem, and as a result even the minimal system of two active electrons and a nucleus is analytically intractable4. This makes experimental measurements of the dynamics of two bound and correlated electrons, as found in the helium atom, an attractive prospect.However, although the motion of single active electrons and holes has been observed with attosecond time resolution5-7, comparable experiments on two-electron motion have so far remained out of reach. Here we showthat a correlated two-electron wave packet can be reconstructed froma 1.2-femtosecondquantumbeatamong low-lying doubly excited states in helium.The beat appears in attosecond transient-absorption spectra5,7-9 measured with unprecedentedly high spectral resolution and in the presence of an intensity-tunable visible laser field.Wetune the coupling10-12 between the two low-lying quantum states by adjusting the visible laser intensity, and use the Fano resonance as a phase-sensitive quantum interferometer13 to achieve coherent control of the two correlated electrons. Given the excellent agreement with large-scalequantum-mechanical calculations for thehelium atom, we anticipate thatmultidimensional spectroscopy experiments of the type we report here will provide benchmark data for testing fundamental few-body quantumdynamics theory in more complex systems. Theymight also provide a route to the site-specificmeasurement and control of metastable electronic transition states that are at the heart of fundamental chemical reactionsWe thank E. Lindroth for calculating the dipole moment (2p2|r|sp2,3+), and also A. Voitkiv, Z.-H. Loh, and R. Moshammer for helpful discussions. We acknowledge financial support by the Max-Planck Research Group Program of the Max-Planck Gesellschaft (MPG) and the European COST Action CM1204 XLIC. L. A. and F. M. acknowledge computer time from the CCC-UAM and Mare Nostrum supercomputer centers and financial support by the European Research Council under the ERC Advanced Grant no. 290853 XCHEM, the Ministerio de Economía y Competitividad projects FIS2010-15127, FIS2013-42002-R and ERA-Chemistry PIM2010EEC-00751, and the European grant MC-ITN CORIN

Cellular Radiosensitivity: How much better do we understand it?

Purpose: Ionizing radiation exposure gives rise to a variety of lesions in DNA that result in genetic instability and potentially tumorigenesis or cell death. Radiation extends its effects on DNA by direct interaction or by radiolysis of H2O that generates free radicals or aqueous electrons capable of interacting with and causing indirect damage to DNA. While the various lesions arising in DNA after radiation exposure can contribute to the mutagenising effects of this agent, the potentially most damaging lesion is the DNA double strand break (DSB) that contributes to genome instability and/or cell death. Thus in many cases failure to recognise and/or repair this lesion determines the radiosensitivity status of the cell. DNA repair mechanisms including homologous recombination (HR) and non-homologous end-joining (NHEJ) have evolved to protect cells against DNA DSB. Mutations in proteins that constitute these repair pathways are characterised by radiosensitivity and genome instability. Defects in a number of these proteins also give rise to genetic disorders that feature not only genetic instability but also immunodeficiency, cancer predisposition, neurodegeneration and other pathologies. Conclusions: In the past fifty years our understanding of the cellular response to radiation damage has advanced enormously with insight being gained from a wide range of approaches extending from more basic early studies to the sophisticated approaches used today. In this review we discuss our current understanding of the impact of radiation on the cell and the organism gained from the array of past and present studies and attempt to provide an explanation for what it is that determines the response to radiation

Mechanical properties and microstructure of fibre-reinforced clay blended with by-product cementitious materials

Clayey soils endure adverse changes in strength and volume due to seasonal changes in moisture content and temperature. It has been well recognised that high cement content has been successfully employed in improving the mechanical properties of clayey soils for geotechnical infrastructural purposes. However, the environmental setbacks regarding the use of high cement content in soil reinforcement have necessitated the need for a greener soil reinforcement technique by incorporating industrial by-product materials and synthetic fibres with a reduced amount of cement content in soil-cement mixtures. Therefore, this study presents an experimental study to investigate the mechanical performance of polypropylene and glass fibre-reinforced cement-clay mixtures blended with ground granulated blast slag (GGBS), lime and micro silica for different mix compositions and curing conditions. The unconfined compressive strength, linear expansion and microstructural analysis of the reinforced soils have been studied. The results show that an increase in polypropylene and glass fibre contents caused an increase in unconfined compressive strength but brought on the reduction of linear expansion of the investigated clay from 7.92% to 0.2% at fibre content up to 0.8% for cement-clay mixture reinforced with 5% Portland cement (PC). The use of 0.4–0.8% polypropylene and glass fibre contents in reinforcing cement-clay mixture at 5% cement content causes an increase in unconfined compressive strength (UCS) values above the minimum UCS target value according to American Society for Testing and Materials (ASTM) 4609 after 7 and 14 days curing at 20◦ C to 50◦ C temperature. Therefore, this new clean production of fibre-reinforced cement-clay mixture blended with industrial by-product materials has great potential for a wide range of applications in subgrade reinforcement