Two-electron water oxidation (2e–WOR) is a promising route toward efficient production of a valuable product in H2O2. Recent attention has focused on developing new electrocatalysts for 2e–WOR, but ...the role of the electrolyte species in determining water oxidation selectivity and promoting 2e–WOR has not been established. Here, we use electroanalytical experiments to confirm the role of HCO3 – as a selective 2e–WOR redox catalyst. We find minimal differences in H2O2 consumption pathways among common electrolytes, indicating that the role of HCO3 – is to promote H2O2 production. Mechanistically, our rotating ring disk experiments show that H2O2 is not generated directly at the disk electrode in KHCO3 but formed after a time delay, suggesting electrolyte oxidation and subsequent hydrolysis as the promotional mechanism. Further electrochemical and spectroscopic experiments confirm this hypothesis, demonstrating anodic oxidation of carbonaceous electrolyte species occurs at Faradaic potentials relevant for water oxidation and that these species (likely HCO4 – or C2O6 2–) subsequently oxidize water to H2O2 (t 1/2 ≈ 5 min). The H2O2 production rate at 2.5 V vs RHE scales linearly with the concentration of HCO3 –, confirming the catalytic role of HCO3 – in 2e–WOR and suggesting the electrolyte can be leveraged to enhance electrochemical H2O2 production.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
We propose that plant foods containing high quantities of starch were essential for the evolution of the human phenotype during the Pleistocene. Although previous studies have highlighted a stone ...tool-mediated shift from primarily plant-based to primarily meat-based diets as critical in the development of the brain and other human traits, we argue that digestible carbohydrates were also necessary to accommodate the increased metabolic demands of a growing brain. Furthermore, we acknowledge the adaptive role cooking played in improving the digestibility and palatability of key carbohydrates. We provide evidence that cooked starch, a source of preformed glucose, greatly increased energy availability to human tissues with high glucose demands, such as the brain, red blood cells, and the developing fetus. We also highlight the auxiliary role copy number variation in the salivary amylase genes may have played in increasing the importance of starch in human evolution following the origins of cooking. Salivary amylases are largely ineffective on raw crystalline starch, but cooking substantially increases both their energy-yielding potential and glycemia. Although uncertainties remain regarding the antiquity of cooking and the origins of salivary amylase gene copy number variation, the hypothesis we present makes a testable prediction that these events are correlated.
Full text
Available for:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Lactase persistence (LP), the continued expression of lactase into adulthood, is the most strongly selected single gene trait over the last 10,000 years in multiple human populations. It has been ...posited that the primary allele causing LP among Eurasians, rs4988235-A 1, only rose to appreciable frequencies during the Bronze and Iron Ages 2, 3, long after humans started consuming milk from domesticated animals. This rapid rise has been attributed to an influx of people from the Pontic-Caspian steppe that began around 5,000 years ago 4, 5. We investigate the spatiotemporal spread of LP through an analysis of 14 warriors from the Tollense Bronze Age battlefield in northern Germany (∼3,200 before present, BP), the oldest large-scale conflict site north of the Alps. Genetic data indicate that these individuals represent a single unstructured Central/Northern European population. We complemented these data with genotypes of 18 individuals from the Bronze Age site Mokrin in Serbia (∼4,100 to ∼3,700 BP) and 37 individuals from Eastern Europe and the Pontic-Caspian Steppe region, predating both Bronze Age sites (∼5,980 to ∼3,980 BP). We infer low LP in all three regions, i.e., in northern Germany and South-eastern and Eastern Europe, suggesting that the surge of rs4988235 in Central and Northern Europe was unlikely caused by Steppe expansions. We estimate a selection coefficient of 0.06 and conclude that the selection was ongoing in various parts of Europe over the last 3,000 years.
•Genomic data from Tollense, the oldest large-scale conflict site north of the Alps•Novel method indicates that Bronze Age warriors represent an unstructured population•Lactase persistence frequency in Tollense (7.1%) is significantly lower than today•Selection coefficient estimate of 6% over the last 3,000 years
Burger et al. report the first genomic data from the oldest known battlefield north of the Alps. With additional data from 55 individuals from sites in Southern and Eastern Europe dating to the Bronze Age, they find evidence for a strong and ongoing selection on lactase persistence in various parts of Europe over the last 3,000 years.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Repeated cocaine exposure causes persistent, maladaptive alterations in brain and behavior, and hope for effective therapeutics lies in understanding these processes. We describe here an essential ...role for fragile X mental retardation protein (FMRP), an RNA-binding protein and regulator of dendritic protein synthesis, in cocaine conditioned place preference, behavioral sensitization, and motor stereotypy. Cocaine reward deficits in FMRP-deficient mice stem from elevated mGluR5 (or GRM5) function, similar to a subset of fragile X symptoms, and do not extend to natural reward. We find that FMRP functions in the adult nucleus accumbens (NAc), a critical addiction-related brain region, to mediate behavioral sensitization but not cocaine reward. FMRP-deficient mice also exhibit several abnormalities in NAc medium spiny neurons, including reduced presynaptic function and premature changes in dendritic morphology and glutamatergic neurotransmission following repeated cocaine treatment. Together, our findings reveal FMRP as a critical mediator of cocaine-induced behavioral and synaptic plasticity.
Display omitted
•FMRP required for cocaine-induced behavioral plasticity and reward•Key role for FMRP in NAc structural and functional synapse plasticity•Structural and functional synapse increases not required for behavioral sensitization•Distinct roles for FMRP in behavioral sensitization and cocaine reward
Smith et al. show that a fragile X/autism-related protein, FMRP, controls multiple cocaine-induced alterations in brain and behavior. Without FMRP, neurons in an addiction-related brain region undergo enhanced synaptic changes, along with altered cocaine-induced reward, sensitization, and stereotypy.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Acoustic scene reconstruction is a process that aims to infer characteristics of the environment from acoustic measurements. We investigate the problem of locating planar reflectors in rooms, such as ...walls and furniture, from signals obtained using distributed microphones. Specifically, localization of multiple two- dimensional (2-D) reflectors is achieved by estimation of the time of arrival (TOA) of reflected signals by analysis of acoustic impulse responses (AIRs). The estimated TOAs are converted into elliptical constraints about the location of the line reflector, which is then localized by combining multiple constraints. When multiple walls are present in the acoustic scene, an ambiguity problem arises, which we show can be addressed using the Hough transform. Additionally, the Hough transform significantly improves the robustness of the estimation for noisy measurements. The proposed approach is evaluated using simulated rooms under a variety of different controlled conditions where the floor and ceiling are perfectly absorbing. Results using AIRs measured in a real environment are also given. Additionally, results showing the robustness to additive noise in the TOA information are presented, with particular reference to the improvement achieved through the use of the Hough transform.
The principal components of neuronal excitability include synaptic and intrinsic membrane parameters. While recent studies indicate that cocaine exposure can induce widespread changes in synaptic ...function in the neural circuits for reward, intrinsic firing properties have received much less attention. Using whole-cell recording in ex vivo brain slices from cocaine-treated mice, we studied the intrinsic firing characteristics of medium-spiny projection neurons of the nucleus accumbens--a key node in the circuit that controls reward-directed behavior. Our data demonstrate that repeated in vivo cocaine (5 x 15 mg/kg, i.p., once daily, 5 d) induces opposite changes in neurons of the two main subdivisions of the accumbens, the shell and the core. While shell neurons exhibit an initial depression in firing capacity (1-3 d abstinence) that persists for at least 2 weeks, core neurons exhibit increased firing capacity during early abstinence (1-3 d) that declines to basal levels within 2 weeks. Shared adaptations between addictive drugs may mediate core processes of addiction. We find that amphetamine exposure (5 x 5 mg/kg, i.p., once daily, 5 d) that induced a similar degree of locomotor sensitization as cocaine also induced an indistinguishable pattern of NAc intrinsic plasticity. Finally, we provided evidence that opposite regulation of A-type potassium current is an important factor in this bidirectional intrinsic plasticity for both cocaine and amphetamine. We propose that a persistent disparity in core/shell excitability might be an important mediator of the changes in reward circuit activity that drive drug-seeking behavior in animal models of addiction.
is a genus within the β
that contains at least 90 validly named species which can be found in a diverse range of environments. A number of pathogenic species occur within the genus. These include
and
..., opportunistic pathogens that can infect the lungs of patients with cystic fibrosis, and are members of the
complex (Bcc).
is also an opportunistic pathogen, but in contrast to Bcc species it causes the tropical human disease melioidosis, while its close relative
is the causative agent of glanders in horses. For these pathogens to survive within a host and cause disease they must be able to acquire iron. This chemical element is essential for nearly all living organisms due to its important role in many enzymes and metabolic processes. In the mammalian host, the amount of accessible free iron is negligible due to the low solubility of the metal ion in its higher oxidation state and the tight binding of this element by host proteins such as ferritin and lactoferrin. As with other pathogenic bacteria,
species have evolved an array of iron acquisition mechanisms with which to capture iron from the host environment. These mechanisms include the production and utilization of siderophores and the possession of a haem uptake system. Here, we summarize the known mechanisms of iron acquisition in pathogenic
species and discuss the evidence for their importance in the context of virulence and the establishment of infection in the host. We have also carried out an extensive bioinformatic analysis to identify which siderophores are produced by each
species that is pathogenic to humans.
Maladaptation to modern diets has been implicated in several chronic disorders. Given the higher prevalence of disease such as dental caries and chronic gum diseases in industrialized societies, we ...sought to investigate the impact of different subsistence strategies on oral health and physiology, as documented by the oral microbiome. To control for confounding variables such as environment and host genetics, we sampled saliva from three pairs of populations of hunter‐gatherers and traditional farmers living in close proximity in the Philippines. Deep shotgun sequencing of salivary DNA generated high‐coverage microbiomes along with human genomes. Comparing these microbiomes with publicly available data from individuals living on a Western diet revealed that abundance ratios of core species were significantly correlated with subsistence strategy, with hunter‐gatherers and Westerners occupying either end of a gradient of Neisseria against Haemophilus, and traditional farmers falling in between. Species found preferentially in hunter‐gatherers included microbes often considered as oral pathogens, despite their hosts' apparent good oral health. Discriminant analysis of gene functions revealed vitamin B5 autotrophy and urease‐mediated pH regulation as candidate adaptations of the microbiome to the hunter‐gatherer and Western diets, respectively. These results suggest that major transitions in diet selected for different communities of commensals and likely played a role in the emergence of modern oral pathogens.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Understanding cumulative cultural evolution Henrich, Joseph; Boyd, Robert; Derex, Maxime ...
Proceedings of the National Academy of Sciences - PNAS,
11/2016, Volume:
113, Issue:
44
Journal Article
Peer reviewed
Open access
Full text
Available for:
BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
The UK-based National Institute for Health and Care Excellence (NICE) has updated its guidance on iron deficiency and anemia management in chronic kidney disease. This report outlines the ...recommendations regarding iron deficiency and their rationale. Serum ferritin alone or transferrin saturation alone are no longer recommended as diagnostic tests to assess iron deficiency. Red blood cell markers (percentage hypochromic red blood cells, reticulocyte hemoglobin content, or reticulocyte hemoglobin equivalent) are better than ferritin level alone at predicting responsiveness to intravenous iron. When red blood cell markers are not available, a combination of transferrin saturation < 20% and ferritin level < 100 ng/mL is an alternative. In comparisons of the cost-effectiveness of different iron status testing and treatment strategies, using percentage hypochromic red blood cells > 6% was the most cost-effective strategy for both hemodialysis and nonhemodialysis patients. A trial of oral iron replacement is recommended in people not receiving an erythropoiesis-stimulating agent (ESA) and not on hemodialysis therapy. For children receiving ESAs, but not treated by hemodialysis, oral iron should be considered. In adults and children receiving ESAs and/or on hemodialysis therapy, intravenous iron should be offered. When giving intravenous iron, high-dose low-frequency administration is recommended. For all children and for adults receiving in-center hemodialysis, low-dose high-frequency administration may be more appropriate.
PDF
