3,474 research outputs found
Hydro-Physicochemical Changes in Domasi River Associated with Outbreak of Blackflies (Diptera; Simuliidae) in Zomba, Malawi
Blackflies impact human and animal health due to their biting nuisance and transmission of Ochocerca volvulus. This study presents an attempt to analyze hydro physicochemical changes associated with outbreak of black flies in Zomba, Malawi. The study compared historical data of hydro physicochemical parameters before (1985-2002) and after (2008) the outbreak to deduce the changes associated with mass occurrence of these flies. Changes in water quality between these two periods were assessed using T-tests. To establish the relationship between the black fly larval densities and water quality parameters data was subjected to both principal component and correlation analysis. Three principal components before the outbreak and two principal components during the outbreak (both dry and wet season) accounted for most of the variation in water quality in this river system. Nutrient load, increases in Total Suspended Solids (TSS) and Total Hardness (TH) were the main factors that had high loadings on these principal components over the years. A significant correlation was established between black fly larval densities and total hardness (r=0.86, p<0.05) as well as total suspended solids (r = 0.755, p<0.02). The potential role of anthropogenic influences on water quality and its cascading effect on black fly population dynamics is discussed
Fueling climate (in)action:How organizations engage in hegemonization to avoid transformational action on climate change
This study examines how organizations avoid the urgent need for transformational action on climate change by engaging in a hegemonization process. To show how this unfolds, we draw from Laclau and Mouffe’s discourse theory, focusing on the case of BP and its engagement with the climate change debate from 1990 to 2015. Our study takes a longitudinal approach to illustrate how BP defended its core business of producing and selling fossil fuel products by enacting three sequential hegemonization strategies. These included: adopting new signifiers; building ‘win-win’ relationships; and adapting nodal points. In doing so, we demonstrate how hegemonic construction enables organizations to both incorporate and evade various types of stakeholder critique, which, we argue, reproduces business-as-usual. Our study contributes to organization studies literature on hegemony by highlighting how the construction of hegemony operates accumulatively over an extended period of time. We also contribute more broadly to conversations around political contests and the natural environment by illustrating how the lack of effective climate responses is shaped by temporal dynamics
Modulation control and spectral shaping of optical fiber supercontinuum generation in the picosecond regime
Numerical simulations are used to study how fiber supercontinuum generation
seeded by picosecond pulses can be actively controlled through the use of input
pulse modulation. By carrying out multiple simulations in the presence of
noise, we show how tailored supercontinuum Spectra with increased bandwidth and
improved stability can be generated using an input envelope modulation of
appropriate frequency and depth. The results are discussed in terms of the
non-linear propagation dynamics and pump depletion.Comment: Aspects of this work were presented in Paper ThJ2 at OECC/ACOFT 2008,
Sydney Australia 7-10 July (2008). Journal paper submitted for publication 30
July 200
Neuromuscular electrical stimulation and dietary interventions to reduce oxidative stress in a secondary progressive multiple sclerosis patient leads to marked gains in function: a case report
Neuromuscular electrical stimulation has been used to aid musculoskeletal recovery. Excessive oxidative stress and excitoxicity are implicated in secondary progressive multiple sclerosis. A 52-year-old white female with SPMS had been scooter- and cane-dependent for 4 years. She requested and received a trial of neuromuscular electrical stimulation. Two months after initiating NMES the patient adopted several nutritional interventions to lower oxidative stress and excito-toxicity. During the first 2 months of neuromuscular electrical stimulation, the therapist observed modest gait improvements. Following the addition of nutritional interventions, more rapids gains in strength and endurance, including muscle groups not receiving neuromuscular electrical stimulation were observed by both the therapist and the patient. After 8 months of neuromuscular electrical stimulation (6 months of nutritional intervention) the patient’s function had improved sufficiently that she no longer used a scooter or cane and rode her bicycle routinely 8 miles, including hills
Recommended from our members
Polarization and dispersion properties of elliptical hole golden spiral photonic crystal fiber
An elliptical air-hole golden spiral photonic crystal fiber (EGS-PCF) is analyzed with the full-vectorial finite element method. The air-holes in the EGS-PCF are arranged in a spiral pattern governed by the Golden Ratio, where the design has been inspired by the optimal arrangement of seeds found in nature. The EGS-PCF exhibits extremely high birefringence (∼0.022 at operating wavelength 1550 nm) which is particularly useful for generating a polarization stable supercontinuum (SC). The fiber can also be designed to have a Zero Dispersion Wavelength (ZDW) at a suitable wavelength for only one polarization and large negative dispersion for the other, leading to a single-polarization SC. In addition, the fiber dispersion can be designed to obtain ZDWs at 800 nm and 1064 nm simultaneously, which can facilitate broadband supercontinuum generation (SCG) through multi-wavelength pumping
Observation of a Turbulence-Induced Large Scale Magnetic Field
An axisymmetric magnetic field is applied to a spherical, turbulent flow of
liquid sodium. An induced magnetic dipole moment is measured which cannot be
generated by the interaction of the axisymmetric mean flow with the applied
field, indicating the presence of a turbulent electromotive force. It is shown
that the induced dipole moment should vanish for any axisymmetric laminar flow.
Also observed is the production of toroidal magnetic field from applied
poloidal magnetic field (the omega-effect). Its potential role in the
production of the induced dipole is discussed.Comment: 5 pages, 4 figures Revisions to accomodate peer-reviewer concerns;
changes to main text including simplification of a proof, Fig. 2 updated, and
minor typos and clarifications; Added refrences. Resubmitted to Phys. Rev.
Let
- …