Mode of action uncovered for the specific reduction of methane emissions from ruminants by the small molecule 3-nitrooxypropanol

Ruminants, such as cows, sheep, and goats, predominantly ferment in their rumen plant material to acetate, propionate, butyrate, CO, and methane. Whereas the short fatty acids are absorbed and metabolized by the animals, the greenhouse gas methane escapes via eructation and breathing of the animals into the atmosphere. Along with the methane, up to 12% of the gross energy content of the feedstock is lost. Therefore, our recent report has raised interest in 3-nitrooxypropanol (3-NOP), which when added to the feed of ruminants in milligram amounts persistently reduces enteric methane emissions from livestock without apparent negative side effects [Hristov AN, et al. (2015) Proc Natl Acad Sci USA 112(34):10663-10668]. We now show with the aid of in silico, in vitro, and in vivo experiments that 3-NOP specifically targets methyl-coenzyme M reductase (MCR). The nickel enzyme, which is only active when its Ni ion is in the+1 oxidation state, catalyzes the methane-forming step in the rumen fermentation. Molecular docking suggested that 3-NOP preferably binds into the active site of MCR in a pose that places its reducible nitrate group in electron transfer distance to Ni(I). With purified MCR, we found that 3-NOP indeed inactivates MCR at micromolar concentrations by oxidation of its active site Ni(I). Concomitantly, the nitrate ester is reduced to nitrite, which also inactivates MCR at micromolar concentrations by oxidation of Ni(I). Using pure cultures, 3-NOP is demonstrated to inhibit growth of methanogenic archaea at concentrations that do not affect the growth of nonmethanogenic bacteria in the rumen.We thank Peter Livant (Auburn University), Elisabeth Jimenez (Consejo Superior de Investigaciones Cientificas), John Wallace (University of Aberdeen), and Jamie Newbold (Aberystwyth University) for the use of the gas chromatograph, for the in vitro culture work, and for providing stock pure cultures, respectively; Ulrich Ermler and the staff of the PXII beam line at Swiss Light Source (Villigen, Switzerland) for helping with the X-ray data collection; and David Rinaldo (Schrödinger, LLC) for molecular modeling support.Peer Reviewe

Baryon Charge Radii and Quadrupole Moments in the 1/N_c Expansion: The 3-Flavor Case

We develop a straightforward method to compute charge radii and quadrupole moments for baryons both with and without strangeness, when the number of QCD color charges is N_c. The minimal assumption of the single-photon exchange ansatz implies that only two operators are required to describe these baryon observables. Our results are presented so that SU(3) flavor and isospin symmetry breaking can be introduced according to any desired specification, although we also present results obtained from two patterns suggested by the quark model with gluon exchange interactions. The method also permits to extract a number of model-independent relations; a sample is r^2_Lambda / r_n^2 = 3/(N_c+3), independent of SU(3) symmetry breaking.Comment: 30 pages, no figures, REVTeX

Bilingualism alters children’s frontal lobe functioning for attentional control

Bilingualism is a typical linguistic experience, yet relatively little is known about its impact on children’s cognitive and brain development. Theories of bilingualism suggest that early dualâ language acquisition can improve children’s cognitive abilities, specifically those relying on frontal lobe functioning. While behavioral findings present much conflicting evidence, little is known about its effects on children’s frontal lobe development. Using functional nearâ infrared spectroscopy (fNIRS), the findings suggest that Spanishâ English bilingual children (n = 13, ages 7â 13) had greater activation in left prefrontal cortex during a nonâ verbal attentional control task relative to ageâ matched English monolinguals. In contrast, monolinguals (n = 14) showed greater right prefrontal activation than bilinguals. The present findings suggest that early bilingualism yields significant changes to the functional organization of children’s prefrontal cortex for attentional control and carry implications for understanding how early life experiences impact cognition and brain development.This fNIRS study investigated the impact of bilingual exposure on children’s brain organization for attentional control (N = 27, ages 7â 13). During a nonâ verbal attention task, bilinguals showed greater left frontal lobe activation than monolinguals. Monolinguals showed greater right frontal lobe activation than bilinguals. The findings suggest that bilingualism affects the functionality of children’s left prefrontal cortex for attentional control.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/1/desc12377-sup-0001-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/2/desc12377.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/3/desc12377_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/4/desc12377-sup-0003-SupInfo.pd

An error tolerant memory aid for reduced cognitive load in number copying tasks

Number copying tasks are still common despite increased digitalization of services. Number copying tasks are cognitively and visually demanding, errors are easily introduced and the process is often perceived as laborious. This study proposes an alternative scheme based on dictionary coding that reduces the cognitive load on the user by a factor of five. The strategy has several levels of error detection and error correction characteristics and is easy to implemen

Tapping the nucleotide pool of the host: novel nucleotide carrier proteins of Protochlamydia amoebophila

Protochlamydia amoebophila UWE25 is related to the Chlamydiaceae comprising major pathogens of humans, but thrives as obligate intracellular symbiont in the protozoan host Acanthamoeba sp. The genome of P. amoebophila encodes five paralogous carrier proteins belonging to the nucleotide transporter (NTT) family. Here we report on three P. amoebophila NTT isoforms, PamNTT2, PamNTT3 and PamNTT5, which possess several conserved amino acid residues known to be critical for nucleotide transport. We demonstrated that these carrier proteins are able to transport nucleotides, although substrate specificities and mode of transport differ in an unexpected manner and are unique among known NTTs. PamNTT2 is a counter exchange transporter exhibiting submillimolar apparent affinities for all four RNA nucleotides, PamNTT3 catalyses an unidirectional proton-coupled transport confined to UTP, whereas PamNTT5 mediates a proton-energized GTP and ATP import. All NTT genes of P. amoebophila are transcribed during intracellular multiplication in acanthamoebae. The biochemical characterization of all five NTT proteins from P. amoebophila in this and previous studies uncovered that these metabolically impaired bacteria are intimately connected with their host cell’s metabolism in a surprisingly complex manner

Working Memory, but Not IQ, Predicts Subsequent Learning in Children with Learning Difficulties

The purpose of the present study was to compare the predictive power of working memory and IQ in children identified as having learning difficulties. The term ‘working memory’ refers to the capacity to store and manipulate information in mind for brief periods of time. Working memory capacity is strongly related to learning abilities and academic progress, predicting current and subsequent scholastic attainments of children across the school years in both literacy and numeracy. Children aged between 7 and 11 years were tested at Time 1 on measures of working memory, IQ, and learning. They were then retested two years later on the learning measures. The findings indicated that working memory capacity and domain-specific knowledge at Time 1, but not IQ, were significant predictors of learning at Time 2. The implications for screening and intervention are discussed

Faster Correlation Attack on Bluetooth Keystream Generator E0

Abstract. We study both distinguishing and key-recovery attacks against E0, the keystream generator used in Bluetooth by means of correlation. First, a powerful computation method of correlations is formulated by a recursive expression, which makes it easier to calculate correlations of the finite state machine output sequences up to 26 bits for E0 and allows us to verify the two known correlations to be the largest for the first time. Second, we apply the concept of convolution to the analysis of the distinguisher based on all correlations, and propose an efficient distinguisher due to the linear dependency of the largest correlations. Last, we propose a novel maximum likelihood decoding algorithm based on fast Walsh transform to recover the closest codeword for any linear code of dimension L and length n. It requires time O(n + L · 2 L) and memory min(n, 2 L). This can speed up many attacks such as fast correlation attacks. We apply it to E0, and our best key-recovery attack works in 2 39 time given 2 39 consecutive bits after O(2 37) precomputation. This is the best known attack against E0 so far.