Research and evidence based environmental health

Environmental health (EH) professionals have often spoken of the need to become more research active (Burke et al., 2002; McCarthy, 1996) and make their work more evidence based, but to date little has been written about how to achieve this in practice. This chapter is therefore written as an introductory guide to research for EH professionals, students, and policy makers. By developing your knowledge it is hoped you will feel more confident navigating the world of research; motivated towards making your own work more evidence based; and enthused about contributing to the evidence base from which others can learn. This chapter is not a research methods textbook, a step by step guide to research or evidence based environmental health, nor does it seek to make definitive statements about these complex areas. However it highlights the most important issues regarding research in environmental health, considers the importance of research to the environmental health profession and provides useful signposts towards further resources. The chapter is divided into three sections. The first defines evidence based environmental health and why it remains a priority for EH professionals. The second section explores the key stages of environmental health research and provides guidance on the development of your reading skills. The final section suggests ways to become more research active and evidence based, acknowledging the many challenges EH professionals face and concluding with a vision for evidence based environmental health. The chapter ends with an annex including a glossary of environmental health research terms, a list of references and suggested further reading

Pengaruh Jenis Persalinan Terhadap Risiko Depresi Postpartum

Latar Belakang: Depresi postpartum sering terjadi pada masa adaptasi psikologis ibu masa nifas, walaupun insidensinya sulit untuk diketahui secara pasti namun diyakini 10-15% ibu melahirkan mengalami gangguan ini. Faktor pada saat persalinan meliputi lamanya persalinan, jenis persalinan, serta intervensi medis yang digunakan mempengaruhi depresi postpartum, anak yang memiliki ibu depresi postpartum akan memiliki gangguan prilaku, rendah fungsi berfikir, mempengaruhi kognitif dan pertumbuhan anak.Tujuan: Mengetahui pengaruh jenis persalinan terhadap risiko depresi postpartum pada ibu nifas di RSUD SlemanMetode:Jenis penelitian yang digunakan adalah survey analitik dengan rancangan kohort retrospektif. Lokasi penelitian di RSUD Sleman Yogyakarta. Populasi pada penelitian ini adalah seluruh ibu nifas yang berkunjung pada poli kebidanan dan kandungan pada bulan Oktober-Desember 2015. Jumlah sampel 110, analisa data dilakukan secara univariat, bivariat dengan uji chi-square dan multivariat dengan uji regresi logistikHasil : Kejadian risiko depresi postpartum pada ibu nifas di RSUD sleman adalah 36,3%, Jenis persalinan berpengaruh secara signifikan terhadap risiko depresi postpartum dengan nilai (OR=3,716, 95%CI 1,620-8,522), Pekerjaan berpengaruh secara signifikan terhadap risiko depresi postpartum dengan nilai (OR=2,411, 95%CI 1,084-5,366), umur, paritas, pendidikan, status ekonomi, dukungan keluarga dan status pernikahan tidak berpengaruh secara signifikan terhadap risiko depresi postpartumKesimpulan :Ibu dengan persalinan bedah sesar mempunyai peluang risiko depresi postpartum 3,716 kali lebih besar dibandingkan ibu yang persalinan pervaginam, sehingga perlu dilakukan deteksi dini untuk melihat risiko depresi postpartum pada ibu nifas agar ibu dapat segera mendapatkan asuhan yang tepat

Spectroscopy of orbital ordering in La0.5Sr1.5MnO4 : A many-body cluster calculation

We have studied the orbital ordering (OO) in La0.5Sr1.5MnO4 and its soft x-ray resonant diffraction spectroscopic signature at the Mn L2, L3 edges. We have modelled the system in second quantization as a small planar cluster consisting of a central Mn atom, with the first neighbouring shells of oxygen and Mn atoms. For the effective Hamiltonian we consider Slater-Koster parameters, charge transfer and electron correlation energies obtained from previous measurements on manganites. We calculate the OO as a function of oxygen distortion and spin correlation used as adjustable parameters. Their contribution as a function of temperature is clearly distinguished with a good spectroscopic agreement.Comment: 5 pages 3 figure

Magnetoelastic mechanism of spin-reorientation transitions at step-edges

The symmetry-induced magnetic anisotropy due to monoatomic steps at strained Ni films is determined using results of first - principles relativistic full-potential linearized augmented plane wave (FLAPW) calculations and an analogy with the N\'eel model. We show that there is a magnetoelastic anisotropy contribution to the uniaxial magnetic anisotropy energy in the vicinal plane of a stepped surface. In addition to the known spin-direction reorientation transition at a flat Ni/Cu(001) surface, we propose a spin-direction reorientation transition in the vicinal plane for a stepped Ni/Cu surface due to the magnetoelastic anisotropy. We show that with an increase of Ni film thickness, the magnetization in the vicinal plane turns perpendicular to the step edge at a critical thickness calculated to be in the range of 16-24 Ni layers for the Ni/Cu(1,1,13) stepped surface.Comment: Accepted for publication in Phys. Rev.

Chromium nanostructures formed by dewetting of heteroepitaxial films on W(100)

In this paper, we report the surprising formation of square-based facetted islands with linear dimension of the order of 500 nm upon dewetting of a Cr multilayer onW(100).We show that these square islands are composed of inclined facets surrounding a depressed center such that the facet slopes inward with the outer edges of the islands thicker than the centers. The islands’ shapes do not represent traditional equilibrium crystal shapes as expected for a Wulf construction. In situ UV and x-ray photoelectron emission microscopy allied to spatially resolved spectroscopy throws considerable light on the nature of the dewetting and shows that the metal surface between the islands remains covered by a thin pseudomorphic wetting layer of ∼1 ML. Low-energy electron diffraction and scanning tunneling and atomic force microscopies allow quantification of facet slopes, and we identify a predominance of tilted Cr(100) facets ±5◦ off of the substrate normal bound by (210) planes at ∼26◦. The epitaxial Cr islands adopt the bulk Cr lattice constant but are tilted with respect to the surface normal.We suggest that the Cr crystallite tilting creates a vicinal-like interface structure that determines the island morpholog

Giant and reversible extrinsic magnetocaloric effects in La0.7Ca0.3MnO3 films due to strain

Large thermal changes driven by a magnetic field have been proposed for environmentally friendly energy efficient refrigeration, but only a few materials which suffer hysteresis show these giant magnetocaloric effects. Here we create giant and reversible extrinsic magnetocaloric effects in epitaxial films of the ferromagnetic manganite La0.7Ca0.3MnO3 using strain mediated feedback from BaTiO3 substrates near a first-order structural phase transition. Our findings should inspire the discovery of giant magnetocaloric effects in a wide range of magnetic materials, and the parallel development of nanostructured bulk samples for practical applications.Comment: 32 pages, 1 Table, 5 figures, supplementary informatio

Driving magnetic order in a manganite by ultrafast lattice excitation

Optical control of magnetism, of interest for high-speed data processing and storage, has only been demonstrated with near-infrared excitation to date. However, in absorbing materials, such high photon energies can lead to significant dissipation, making switch back times long and miniaturization challenging. In manganites, magnetism is directly coupled to the lattice, as evidenced by the response to external and chemical pressure, or to ferroelectric polarization. Here, femtosecond mid-infrared pulses are used to excite the lattice in La0.5Sr1.5MnO4 and the dynamics of electronic order are measured by femtosecond resonant soft x-ray scattering with an x-ray free electron laser. We observe that magnetic and orbital orders are reduced by excitation of the lattice. This process, which occurs within few picoseconds, is interpreted as relaxation of the complex charge-orbital-spin structure following a displacive exchange quench - a prompt shift in the equilibrium value of the magnetic and orbital order parameters after the lattice has been distorted. A microscopic picture of the underlying unidirectional lattice displacement is proposed, based on nonlinear rectification of the directly-excited vibrational field, as analyzed in the specific lattice symmetry of La0.5Sr1.5MnO4. Control of magnetism through ultrafast lattice excitation has important analogies to the multiferroic effect and may serve as a new paradigm for high-speed optomagnetism.Comment: 10 pages manuscript, 4 figure

Magnetic iron oxide nanowires formed by reactive dewetting

The growth and reactive dewetting of ultra-thin films of iron oxides supported on Re(0001) surfaces have been imaged in-situ in real time. Initial growth forms a non-magnetic stable FeO (wüstite like) layer in a commensurate network upon which high aspect ratio nanowires of several microns length but less than 40nm width can be fabricated. The nanowires are closely aligned with the substrate crystallography and imaging by X-ray magnetic circular dichroism shows that each contain a single magnetic domain. The driving force for dewetting appears to be the minimization of strain energy of the Fe3O4 crystallites and follows the Tersoff and Tromp model in which strain is minimized at constant height by extending in one epitaxially matched direction. Such wires are promising in spintronic applications and we predict that the growth will also occur on other hexagonal substrates

Possible observation of parametrically amplified coherent phasons in K0.3MoO3 using time-resolved extreme-ultraviolet ARPES

We use time- and angle-resolved photoemission spectroscopy (tr-ARPES) in the Extreme Ultraviolet (EUV) to measure the time- and momentum-dependent electronic structure of photo-excited K0.3MoO3. Prompt depletion of the Charge Density Wave (CDW) condensate launches coherent oscillations of the amplitude mode, observed as a 1.7-THz-frequency modulation of the bonding band position. In contrast, the anti-bonding band oscillates at about half this frequency. We attribute these oscillations to coherent excitation of phasons via parametric amplification of phase fluctuations.Comment: 4 figure