Routine monitoring of body iron stores is an essential component of overall management for the patient on hemodialysis. Adequate iron levels are important for the prevention and treatment of ...iron-deficiency anemia, which is associated with reduced physical functioning, cardiovascular disease, and poor quality of life. Hemodialysis patients are at especially high risk for iron-deficiency anemia, owing to continuous blood losses and supraphysiologic levels of erythropoiesis driven by recombinant human erythropoietin therapy. Unfortunately, the accurate determination of iron status in these patients can be a challenging task, which is made more difficult by inflammation, infections, and the large number of comorbid conditions that can affect commonly used indices of body iron stores. Despite their limitations, transferrin saturation (TSAT) and serum ferritin remain the cornerstones of iron status assessment. Because these values can be altered by a number of non-iron-related factors, it is necessary to go beyond these measures and draw upon additional sources of information to determine the patient's iron status. Other important factors to consider when assessing the need for iron therapy include evidence of underlying inflammatory processes that may block iron mobilization and distort the standard iron indices, the results of alternative iron indices, and the patient's recent history of iron administration. Frequently, the response to a gram of intravenous (i.v.) iron is a safe and effective way to determine the role of iron deficiency in the anemia of the problematic patient. The chronic inflammatory state associated with malnutrition and clinical or subclinical infections substantially increases the risk of misdiagnosing the patient with iron overload and may place the patient at risk of iron deficiency owing to inappropriate withdrawal of i.v. iron therapy. To avoid the risks of withholding iron therapy, the nephrologist must keep this relationship in mind whenever serum ferritin testing suggests replete iron stores, whereas TSAT testing suggests insufficient iron availability.
•Intensification of smallholder agriculture is a must for most of sub-Saharan Africa.•Sustainable Intensification (SI) integrates productivity, other services & resilience.•Pathways to SI should ...recognise the diversity of farming environments.•SI of smallholder systems in sub-Saharan Africa requires enabling conditions.•Scaling SI will require investments in strengthening local innovation.
Sub-Saharan Africa needs to produce more food, feed, and fiber to support its growing population and intensification of smallholder agriculture is a crucial component of any strategy towards this goal. Sustainable Intensification (SI) acknowledges that enhanced productivity needs to go hand in hand with the maintenance of other ecosystem services and enhanced resilience to shocks. A very diverse group of smallholders dominate SSA agriculture, with large heterogeneity in socio-technical conditions, famer typologies, production objectives, and the biophysical environment. This potentially generates a multitude of pathways from the current low productivity based on nutrient mining to SI. The institutional context needs to be right for delivering the necessary goods and services underlying SI, ensuring inclusiveness across household types and facilitating local innovation.
The measurement of minuscule forces and displacements with ever greater precision is inhibited by the Heisenberg uncertainty principle, which imposes a limit to the precision with which the position ...of an object can be measured continuously, known as the standard quantum limit
. When light is used as the probe, the standard quantum limit arises from the balance between the uncertainties of the photon radiation pressure applied to the object and of the photon number in the photoelectric detection. The only way to surpass the standard quantum limit is by introducing correlations between the position/momentum uncertainty of the object and the photon number/phase uncertainty of the light that it reflects
. Here we confirm experimentally the theoretical prediction
that this type of quantum correlation is naturally produced in the Laser Interferometer Gravitational-wave Observatory (LIGO). We characterize and compare noise spectra taken without squeezing and with squeezed vacuum states injected at varying quadrature angles. After subtracting classical noise, our measurements show that the quantum mechanical uncertainties in the phases of the 200-kilowatt laser beams and in the positions of the 40-kilogram mirrors of the Advanced LIGO detectors yield a joint quantum uncertainty that is a factor of 1.4 (3 decibels) below the standard quantum limit. We anticipate that the use of quantum correlations will improve not only the observation of gravitational waves, but also more broadly future quantum noise-limited measurements.
The diffuse gamma radiation arising from the interaction of cosmic-ray particles with matter and radiation in the Galaxy is one of the few probes available to study the origin of the cosmic rays. ...Data from the Milagro gamma-ray observatory--a water Cerenkov detector that continuously views 62 sr of the overhead sky--shows that the brightest extended region in the entire northern sky is the Cygnus region of the Galactic plane. The TeV image of the Cygnus region contains at least one new source, MGRO J2019+37, which is 10.9 s above the isotropic background, as well as correlations with the matter density in the region. However, the gamma-ray flux from the Cygnus region (after excluding MGRO J2019+37) as measured at 612 TeV exceeds that predicted from a model of cosmic-ray production and propagation. This observation indicates the existence of either hard-spectrum cosmic-ray sources and/or unresolved sources of TeV gamma rays in the region.
Brain histaminergic neurons play a prominent role in arousal and maintenance of wakefulness (W). H(3)-receptors control the activity of histaminergic neurons through presynaptic autoinhibition. The ...role of H(3)-receptor antagonists/inverse agonists (H(3)R-antagonists) in the potential therapy of vigilance deficiency and sleep-wake disorders were studied by assessing their effects on the mouse cortical EEG and sleep-wake cycle in comparison to modafinil and classical psychostimulants. The H(3)R-antagonists, thioperamide and ciproxifan increased W and cortical EEG fast rhythms and, like modafinil, but unlike amphetamine and caffeine, their waking effects were not accompanied by sleep rebound. Conversely, imetit (H(3)R-agonist) enhanced slow wave sleep and dose-dependently attenuated ciproxifan-induced W, indicating that the effects of both ligands involve H(3)-receptor mechanisms. Additional studies using knockout (KO) mice confirmed the essential role of H(3)-receptors and histamine-mediated transmission in the wake properties of H(3)R-antagonists. Thus ciproxifan produced no increase in W in either histidine-decarboxylase (HDC, histamine-synthesizing enzyme) or H(1)- or H(3)-receptor KO-mice whereas its waking effects persisted in H(2)-receptor KO-mice. These data validate the hypothesis that H(3)R-antagonists, through disinhibition of H(3)-autoreceptors, enhancing synaptic histamine that in turn activates postsynaptic H(1)-receptors promoting W. Interestingly amphetamine and modafinil, despite their potent arousal effects, appear unlikely to depend on histaminergic mechanism as their effects still occurred in HDC KO-mice. The present study thus distinguishes two classes of wake-improving agents: the first acting through non-histaminergic mechanisms and the second acting via histamine and supports brain H(3)-receptors as potentially novel therapeutic targets for vigilance and sleep-wake disorders.
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