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In this contribution, we present "Birch‐type", and other reductions of simple arenes by the potassium salt of an anionic magnesium dinitrogen complex, [{K(TCHPNON)Mg}2(μ‐N2)] (TCHPNON=4,5‐bis(2,4,6‐tricyclohexylanilido)‐2,7‐diethyl‐9,9‐dimethyl‐xanthene), which acts as a masked dimagnesium(I) diradical in these reactions. This reagent is non‐hazardous, easy‐to‐handle, and in some cases provides access to 1,4‐cyclohexadiene reduction products under relatively mild reaction conditions. This system works effectively to reduce benzene, naphthalene and anthracene through magnesium‐bound "Birch‐type" reduction intermediates. Cyclohexadiene products can be subsequently released from the magnesium centres by protonolysis with methanol. In contrast, the reduction of substituted arenes is less selective and involves competing reaction pathways. For toluene and 1,3,5‐triphenylbenzene, the structural authentication of "Birch‐type" reduction intermediates is conclusive, although the formation of corresponding 1,4‐cyclohexadiene derivatives was low yielding. Reduction of anisole did not yield an isolable "Birch‐type" intermediate, but instead gave a C−O activation product. Treating triphenylphosphine with [{K(TCHPNON)Mg}2(μ‐N2)] resulted in the extrusion of both biphenyl and dinitrogen to afford a magnesium(II) phosphanide [{K(TCHPNON)Mg(μ‐PPh2)}2]. Reduction of fluorobenzene proceeded via C−F activation of the arene, and isolation of the magnesium(II) fluoride [{K(TCHPNON)Mg(μ‐F)}2]. Finally, the two‐electron reduction of 1,3,5,7‐cyclooctatetraene (COT) with [{K(TCHPNON)Mg}2(μ‐N2)] yielded a complex, [{K(TCHPNON)Mg}2(μ‐COT)], incorporating the aromatic dianion (COT2−). [ABSTRACT FROM AUTHOR]

The bulky β‐diketiminate ligand frameworks [BDIDCHP]− and [BDIDipp/Ar]− (BDI=[HC{C(Me)2N‐Dipp/Ar}2]− (Dipp=2,6‐diisopropylphenyl (Dipp); Ar=2,6‐dicyclohexylphyenyl (DCHP) or 2,4,6‐tricyclohexylphyenyl (TCHP)) have been developed for the kinetic stabilisation of the first europium (II) hydride complexes, [(BDIDCHP)Eu(μ‐H)]2, [(BDIDipp/DCHP)Eu(μ‐H)]2 and [(BDIDipp/TCHP)Eu(μ‐H)]2, respectively. These complexes represent the first step beyond the current lanthanide(II) hydrides that are all based on ytterbium. Tuning the steric profile of β‐diketiminate ligands from a symmetrical to unsymmetrical disposition, enhanced solubility and stability in the solution–state. This provides the first opportunity to study the structure and bonding of these novel Eu(II) hydride complexes crystallographically, spectroscopically and computationally, with their preliminary reactivity investigated. [ABSTRACT FROM AUTHOR]

A simple sequential addition protocol for the reductive coupling of ketones and aldehydes by a potassium aluminyl grants access to unsymmetrical pinacolate derivatives. Isolation of an aluminium ketyl complex presents evidence for the accessibility of radical species. Product release from the aluminium centre was achieved using an iodosilane, forming the disilylated 1,2‐diol and a neutral aluminium iodide, thereby demonstrating the steps required to generate a closed synthetic cycle for pinacol (cross) coupling at an aluminyl anion. [ABSTRACT FROM AUTHOR]

The reaction of 9‐diazo‐9H‐fluorene (fluN2) with the potassium aluminyl K[Al(NON)] ([NON]2−=[O(SiMe2NDipp)2]2−, Dipp=2,6‐iPr2C6H3) affords K[Al(NON)(κN1,N3‐{(fluN2)2})] (1). Structural analysis shows a near planar 1,4‐di(9H‐fluoren‐9‐ylidene)tetraazadiide ligand that chelates to the aluminium. The thermally induced elimination of dinitrogen from 1 affords the neutral aluminium ketimide complex, Al(NON)(N=flu)(THF) (2) and the 1,2‐di(9H‐fluoren‐9‐yl)diazene dianion as the potassium salt, [K2(THF)3][fluN=Nflu] (3). The reaction of 2 with N,N'‐diisopropylcarbodiimide (iPrN=C=NiPr) affords the aluminium guanidinate complex, Al(NON){N(iPr)C(N=CMe2)N(CHflu)} (4), showing a rare example of reactivity at a metal ketimide ligand. Density functional theory (DFT) calculations have been used to examine the bonding in the newly formed [(fluN2)2]2− ligand in 1 and the ketimide bonding in 2. The mechanism leading to the formation of 4 has also been studied using this technique. [ABSTRACT FROM AUTHOR]

Three distinct routes are reported to the soluble, dihydridoaluminate compounds, AM[Al(NONDipp)(H)2] (AM=Li, Na, K, Rb, Cs; [NONDipp]2−=[O(SiMe2NDipp)2]2−; Dipp=2,6‐iPr2C6H3) starting from the alkali metal aluminyls, AM[Al(NONDipp)]. Direct H2 hydrogenation of the heavier analogues (AM=Rb, Cs) produced the first examples of structurally characterized rubidium and caesium dihydridoaluminates, although harsh conditions were required for complete conversion. Using 1,4‐cyclohexadiene (1,4‐CHD) as an alternative hydrogen source in transfer hydrogenation reactions provided a lower energy pathway to the full series of products for AM=Li−Cs. A further moderation in conditions was noted for the thermal decomposition of the (silyl)(hydrido)aluminates, AM[Al(NONDipp)(H)(SiH2Ph)]. Probing the reaction of Cs[Al(NONDipp)] with 1,4‐CHD provided access to a novel inverse sandwich complex, [{Cs(Et2O)}2{Al(NONDipp)(H)}2(C6H6)], containing the 1,4‐dialuminated [C6H6]2− dianion and representing the first time that an intermediate in the commonly utilized oxidation process of 1,4‐CHD to benzene has been trapped. The synthetic utility of the newly installed Al−H bonds has been demonstrated by their ability to reduce CO2 under mild conditions to form the bis‐formate AM[Al(NONDipp)(O2CH)2] compounds, which exhibit a diverse series of eyecatching bimetallacyclic structures. [ABSTRACT FROM AUTHOR]

The activation of dinitrogen (N2) by transition metals is central to the highly energy intensive, heterogeneous Haber–Bosch process. Considerable progress has been made towards more sustainable homogeneous activations of N2 with d‐ and f‐block metals, though little success has been had with main group metals. Here we report that the reduction of a bulky magnesium(II) amide [(TCHPNON)Mg] (TCHPNON=4,5‐bis(2,4,6‐tricyclohexylanilido)‐2,7‐diethyl‐9,9‐dimethyl‐xanthene) with 5 % w/w K/KI yields the magnesium‐N2 complex [{K(TCHPNON)Mg}2(μ‐N2)]. DFT calculations and experimental data show that the dinitrogen unit in the complex has been reduced to the N22− dianion, via a transient anionic magnesium(I) radical. The compound readily reductively activates CO, H2 and C2H4, in reactions in which it acts as a masked dimagnesium(I) diradical. [ABSTRACT FROM AUTHOR]

The potassium aluminyl [K{Al(NONDipp)}]2 ([NONDipp]2−=[O{SiMe2NDipp}2]2−, Dipp=2,6‐iPr2C6H3) activates ethene towards carbonylation with CO under mild conditions. An isolated bis‐aluminacyclopropane compound reacted with CO via carbonylation of an Al−C bond, followed by an intramolecular hydrogen shift to form K2[Al(NONDipp)(μ‐CH2CH=CO‐1κ2C1,3‐2κO)Al(NONDipp)Et]. Restricting the chemistry to a mono‐aluminium system allowed isolation of [Al(NONDipp)(CH2CH2CO‐κ2C1,3)]−, which undergoes thermal isomerisation to form the [Al(NONDipp)(CH2CH=CHO‐κ2C,O)]− anion. DFT calculations highlight the stabilising influence of incorporated benzene at multiple steps in the reaction pathways. [ABSTRACT FROM AUTHOR]

To date, aluminyl anions have been exclusively isolated as their potassium salts. We report herein the synthesis of the lithium and sodium aluminyls, M2[Al(NONDipp)]2 (M=Li, Na. NONDipp=[O(SiMe2NDipp)2]2−; Dipp=2,6‐iPr2C6H3). Both compounds crystallize from non‐coordinating solvent as "slipped" contacted dimeric pairs with strong M⋅⋅⋅π(aryl) interactions. Isolation from Et2O solution affords the monomeric ion pairs (NONDipp)Al‐M(Et2O)2, which contain discrete Al−Li and Al−Na bonds. The ability of the full series of Li, Na and K aluminyls to activate dihydrogen is reported. [ABSTRACT FROM AUTHOR]

The synthesis and structural characterisation of [(NONR)M] (NON=O(SiMe2NR)2]2−; R=tBu, Ph, 2,6‐Me2C6H3 (Dmp), 2,6‐iPr2C6H3 (Dipp); M=Ge, Sn, Pb) is described. Germanium complexes [(NONPh)Ge], [(NONDmp)Ge] and [(NONDipp)Ge] are monomeric. Tin complexes [(NONPh)Sn]2, [(NONDmp)Sn]2 and [(NONtBu)Sn]2 are dimeric in the solid‐state, with [(NONPh)Sn]2 forming a link through bridging N‐atoms, [(NONDmp)Sn]2 linked through Sn⋅⋅⋅Ar contacts and [(NONtBu)Sn]2 forming the first distannene bearing two amido ligands. In contrast, [(NONDipp)Sn] is monomeric in the solid‐state. The lead complexes [(NONPh)Pb]2 and [(NONDmp)Pb]2 are isostructual with their tin analogues while [(NONtBu)Pb] is monomeric in the solid‐state. Solution phase NMR spectroscopic data suggest that all [(NONR)M] compounds are monomeric in solution. Structural parameters, including buried volume (%Vbur) are discussed. [ABSTRACT FROM AUTHOR]

Addition of MesN3 (Mes=2,4,6‐Me3C6H2) to germylene [(NONtBu)Ge] (NONtBu=O(SiMe2NtBu)2) (1) gives germanimine, [(NONtBu)Ge=NMes] (2). Compound 2 behaves as a metalloid, showing reactivity reminiscent of both transition metal‐imido complexes, undergoing [2+2] addition with heterocumulenes and protic sources, as well as an activated diene, undergoing a [4+2] cycloaddition, or "metallo"‐Diels–Alder, reaction. In the latter case, the diene includes the Ge=N bond and π‐system of the Mes substituent, which is reactive towards dienophiles including benzaldehyde, benzophenone, styrene, and phenylacetylene. [ABSTRACT FROM AUTHOR]

Background: Propionibacterium acnes may be transmitted from the subdermal tissues to the deeper tissues during shoulder arthroplasty surgery, resulting in deep infection. The aim of this prospective, clinical study was to determine whether the use of a wound protector drape can lower the incidence of P. acnes in the wound during shoulder arthroplasty surgery. Methods: For a consecutive series of 47 patients undergoing shoulder arthroplasty, a wound protector drape was used during surgery, to isolate the subdermal layer from the surgeons' hands, retractors and other instruments. Microbiological swabs were taken both from the subdermal layer and the exposed drape to determine the incidence of P. acnes at both sites. Results: The overall incidence of P. acnes in the subdermal layer was 23%. A fivefold decrease in the incidence of P. acnes in the exposed superficial layer was demonstrated by use of the wound protector drape. Conclusion: Use of a wound protector drape to isolate the superficial tissue layer from the surgeons' gloves, instruments and retractors decreases the incidence of P. acnes in the surgical field. This may result in a decreased rate of transmission to the deeper tissues, and a decreased rate of P. acnes deep infection. [ABSTRACT FROM AUTHOR]

Three distinct routes are reported to the soluble, dihydridoaluminate compounds, AM[Al(NONDipp)(H)2] (AM=Li, Na, K, Rb, Cs; [NONDipp]2−=[O(SiMe2NDipp)2]2−; Dipp=2,6‐iPr2C6H3) starting from the alkali metal aluminyls, AM[Al(NONDipp)]. Direct H2 hydrogenation of the heavier analogues (AM=Rb, Cs) produced the first examples of structurally characterized rubidium and caesium dihydridoaluminates, although harsh conditions were required for complete conversion. Using 1,4‐cyclohexadiene (1,4‐CHD) as an alternative hydrogen source in transfer hydrogenation reactions provided a lower energy pathway to the full series of products for AM=Li−Cs. A further moderation in conditions was noted for the thermal decomposition of the (silyl)(hydrido)aluminates, AM[Al(NONDipp)(H)(SiH2Ph)]. Probing the reaction of Cs[Al(NONDipp)] with 1,4‐CHD provided access to a novel inverse sandwich complex, [{Cs(Et2O)}2{Al(NONDipp)(H)}2(C6H6)], containing the 1,4‐dialuminated [C6H6]2− dianion and representing the first time that an intermediate in the commonly utilized oxidation process of 1,4‐CHD to benzene has been trapped. The synthetic utility of the newly installed Al−H bonds has been demonstrated by their ability to reduce CO2 under mild conditions to form the bis‐formate AM[Al(NONDipp)(O2CH)2] compounds, which exhibit a diverse series of eyecatching bimetallacyclic structures. [ABSTRACT FROM AUTHOR]

Long-distance signalling is important for coordinating plant responses to the environment. Variation potentials ( VPs) are a type of long-distance electrical signal that are generated in plants in response to wounding or flaming. Unlike self-propagating action potentials, VPs can be measured beyond regions of dead or chemically treated tissue that block signal generation, suggesting a different mode of propagation. Two alternative propagation mechanisms have been proposed: movement of a chemical agent and a pressure wave through the vasculature. Variants of these two signalling mechanisms have been suggested. Here, we use simple models of the underlying physical processes to evaluate and compare these predictions against independent data. Our models suggest that chemical diffusion and pressure waves are unlikely to capture existing data with parameters that are known from other sources. The previously discarded hypothesis of mass flow in the xylem transporting a chemical agent, however, is able to reproduce experimental propagation speeds for VPs. We therefore suggest that chemical agents transported by mass flow within the xylem are more likely than a pressure wave or chemical diffusion as a VP propagation mechanism. Understanding this mode of long-distance signalling within plants is important for unravelling how plants coordinate physiological responses via cell-to-cell communication. [ABSTRACT FROM AUTHOR]

Quantifying muscle water T2 ( T2-water) independently of intramuscular fat content is essential in establishing T2-water as an outcome measure for imminent new therapy trials in neuromuscular diseases. IDEAL-CPMG combines chemical shift fat-water separation with T2 relaxometry to obtain such a measure. Here we evaluate the reproducibility and B1 sensitivity of IDEAL-CPMG T2-water and fat fraction (f.f.) values in healthy subjects, and demonstrate the potential of the method to quantify T2-water variation in diseased muscle displaying varying degrees of fatty infiltration. The calf muscles of 11 healthy individuals (40.5 ± 10.2 years) were scanned twice at 3 T with an inter-scan interval of 4 weeks using IDEAL-CPMG, and 12 patients with hypokalemic periodic paralysis (HypoPP) (42.3 ± 11.5 years) were also imaged. An exponential was fitted to the signal decay of the separated water and fat components to determine T2-water and the fat signal amplitude muscle regions manually segmented. Overall mean calf-level muscle T2-water in healthy subjects was 31.2 ± 2.0 ms, without significant inter-muscle differences ( p = 0.37). Inter-subject and inter-scan coefficients of variation were 5.7% and 3.2% respectively for T2-water and 41.1% and 15.4% for f.f. Bland-Altman mean bias and ±95% coefficients of repeatability were for T2-water (0.15, −2.65, 2.95) ms and f.f. (−0.02, −1.99, 2.03)%. There was no relationship between T2-water (ρ = 0.16, p = 0.07) or f.f. (ρ = 0.03, p = 0.7761) and B1 error or any correlation between T2-water and f.f. in the healthy subjects (ρ = 0.07, p = 0.40). In HypoPP there was a measurable relationship between T2-water and f.f. (ρ = 0.59, p < 0.001). IDEAL-CPMG provides a feasible way to quantify T2-water in muscle that is reproducible and sensitive to meaningful physiological changes without post hoc modeling of the fat contribution. In patients, IDEAL-CPMG measured elevations in T2-water and f.f. while showing a weak relationship between these parameters, thus showing promise as a practical means of quantifying muscle water in patient populations. [ABSTRACT FROM AUTHOR]

Woodlands provide valuable ecosystem services, and it is important to understand their dynamics. To predict the way in which these might change, we need process-based predictive ecological models, but these are necessarily very data intensive. We tested the ability of existing datasets to provide the parameters necessary to instantiate a well-used forest model ( SORTIE) for a well-studied woodland (Wytham Woods). Only five of SORTIE's 16 equations describing different aspects of the life history and behavior of individual trees could be parameterized without additional data collection. One age class - seedlings - was completely missed as they are shorter than the height at which Diameter at Breast Height (DBH) is measured. The mensuration of trees has changed little in the last 400 years (focussing almost exclusively on DBH) despite major changes in the nature of the source of value obtained from trees over this time. This results in there being insufficient data to parameterize process-based models in order to meet the societal demand for ecological prediction. We do not advocate ceasing the measurement of DBH, but we do recommend that those concerned with tree mensuration consider whether additional measures of trees could be added to their data collection protocols. We also see advantages in integrating techniques such as ground-based LIDAR or remote sensing techniques with long-term datasets to both preserve continuity with what has been performed in the past and to expand the range of measurements made. [ABSTRACT FROM AUTHOR]

The predation of wildlife by domestic cats ( Felis catus) is a complex problem: Cats are popular companion animals in modern society but are also acknowledged predators of birds, herpetofauna, invertebrates, and small mammals. A comprehensive understanding of this conservation issue demands an understanding of both the ecological consequence of owning a domestic cat and the attitudes of cat owners. Here, we determine whether cat owners are aware of the predatory behavior of their cats, using data collected from 86 cats in two UK villages. We examine whether the amount of prey their cat returns influences the attitudes of 45 cat owners toward the broader issue of domestic cat predation. We also contribute to the wider understanding of physiological, spatial, and behavioral drivers of prey returns among cats. We find an association between actual prey returns and owner predictions at the coarse scale of predatory/nonpredatory behavior, but no correlation between the observed and predicted prey-return rates among predatory cats. Cat owners generally disagreed with the statement that cats are harmful to wildlife, and disfavored all mitigation options apart from neutering. These attitudes were uncorrelated with the predatory behavior of their cats. Cat owners failed to perceive the magnitude of their cats' impacts on wildlife and were not influenced by ecological information. Management options for the mitigation of cat predation appear unlikely to work if they focus on 'predation awareness' campaigns or restrictions of cat freedom. [ABSTRACT FROM AUTHOR]

We report the frequency, positive rate, and type of mutations in 14 genes ( PMP22, GJB1, MPZ, MFN2, SH3TC2, GDAP1, NEFL, LITAF, GARS, HSPB1, FIG4, EGR2, PRX, and RAB7A) associated with Charcot-Marie-Tooth disease ( CMT) in a cohort of 17,880 individuals referred to a commercial genetic testing laboratory. Deidentified results from sequencing assays and multiplex ligation-dependent probe amplification ( MLPA) were analyzed including 100,102 Sanger sequencing, 2338 next-generation sequencing ( NGS), and 21,990 MLPA assays. Genetic abnormalities were identified in 18.5% ( n = 3312) of all individuals. Testing by Sanger and MLPA ( n = 3216) showed that duplications (dup) (56.7%) or deletions (del) (21.9%) in the PMP22 gene accounted for the majority of positive findings followed by mutations in the GJB1 (6.7%), MPZ (5.3%), and MFN2 (4.3%) genes. GJB1 del and mutations in the remaining genes explained 5.3% of the abnormalities. Pathogenic mutations were distributed as follows: missense (70.6%), nonsense (14.3%), frameshift (8.7%), splicing (3.3%), in-frame deletions/insertions (1.8%), initiator methionine mutations (0.8%), and nonstop changes (0.5%). Mutation frequencies, positive rates, and the types of mutations were similar between tests performed by either Sanger ( n = 17,377) or NGS ( n = 503). Among patients with a positive genetic finding in a CMT-related gene, 94.9% were positive in one of four genes ( PMP22, GJB1, MPZ, or MFN2). [ABSTRACT FROM AUTHOR]

Spinal muscular atrophy (SMA) is a neurodegenerative disease that causes progressive muscle weakness, which primarily targets proximal muscles. About 95% of SMA cases are caused by the loss of both copies of the SMN1 gene. SMN2 is a nearly identical copy of SMN1, which expresses much less functional SMN protein. SMN2 is unable to fully compensate for the loss of SMN1 in motor neurons but does provide an excellent target for therapeutic intervention. Increased expression of functional full-length SMN protein from the endogenous SMN2 gene should lessen disease severity. We have developed and implemented a new high-throughput screening assay to identify small molecules that increase the expression of full-length SMN from a SMN2 reporter gene. Here, we characterize two novel compounds that increased SMN protein levels in both reporter cells and SMA fibroblasts and show that one increases lifespan, motor function, and SMN protein levels in a severe mouse model of SMA. [ABSTRACT FROM AUTHOR]

Secondary sexual signals are thought to indicate individual quality. In order to understand the evolutionary pressures that give rise to such traits it is important to understand the physiological mechanisms underlying their production. The black bib of the house sparrow Passer domesticus is known to function as a badge of social status in males. Past studies have found that the size of the bib in older males is determined, at least partly, by the androgen testosterone. The immunocompetence handicap hypothesis suggests that testosterone has a key role in maintaining honest signalling - it is both involved in the development or expression of sexual signals and is immunosuppressive. In this paper we test experimentally two hypo theses relating to bib size development, whether 1) testosterone is only immunosuppressive in conditions where the natural feedback loop from the testes has been removed, and 2) testosterone is, in addition to influencing the bib size of older males, responsible for the size of the bib in juvenile sparrows. In the first experiment we found that exogenous testosterone administered to intact males during the winter (when LH and FSH levels are very low and were not artificially increased by castration) caused significant immunosuppression, albeit in interaction with the stress hormone corticosterone. Second, we found that exogenous testosterone administration in castrated fledgling male house sparrows had no effect on subsequent post-juvenile moult bib size relative to controls. Our results suggest that in some circumstances testosterone can be immunosuppressive, but that its role in bib size determination is age-dependent. [ABSTRACT FROM AUTHOR]

The article discusses a cohort study which determined the association between acute coronary syndromes (ACS) and carotid atherosclerosis in rheumatoid arthritis (RA) patients. It is inferred that RA patients with carotid plaque, multiple cardiovascular (CV) risk factors, swollen joints, and a high cumulative dose of glucocorticoids, and patients who are men, are at a high risk of ACS, as atherosclerosis is strongly associated with ACS in RA.

There have been surprisingly few analyses of how the international trade in amphibians for food affects the conservation status of this group. We analyzed information from the UN Commodity Trade Statistics Database and found that, by volume, Indonesia supplied nearly half of the animals entering the world's US$40 million per year international frog legs trade, and that - collectively - France, Belgium, and the US imported more than 75% of all frog legs traded internationally. Nonetheless, a close examination of available information from 1996 through 2006 revealed that most countries throughout the world participated in the frog legs trade at some level. These extensive international amphibian trade networks could facilitate the spread of pathogens, including Batrachochytrium dendrobatidis, which has been identified as a threat connected with the disappearance and possible extinction of over 90 amphibian species around the world. Given the size and extent of the international trade in frog legs, we advocate for the rigorous implementation of clear policies regulating the domestic and international movement of amphibians for food. [ABSTRACT FROM AUTHOR]

The writings of Johann Gottfried Herder (1744-1803) foreshadowed several of the dominant theories of sociology, social psychology, aesthetics, linguistics and literary theory. His ideas impacted generations of thinkers, but today he is uncelebrated, mostly unknown. His writings on populism, expressionism, and pluralism are relevant to contemporary sociology, especially community sociology. Here we consider his views on the nature and meaning of community, and his methods of studying and interpreting communities. These include an emphasis on the essential particularity of human communities and their connection to wider systems and networks. Herder urges special attention to the elements of context (place, time, language, culture) within which communities are situated. Herder's is an embedded particularism, a focus on individuality and diversity within larger unities. He also sensitizes us to the multivalence and multiplicity of social phenomena. As the proper stance for community research he counsels involvement and empathy rather than objectivity and emotional distance, and he urges researchers to be sensitive to data from all of their senses, not merely sight. Drawing upon Herder's writings, we conclude with several important methodological principles relevant to improving current work on the nature and conceptualization of communities. [ABSTRACT FROM AUTHOR]

Laboratory analogues of classroom activities on which children with low working memory skills have been observed to perform very poorly were developed and employed in two studies. In Study 1, 5- and 6-year-old completed one task involving recalling spoken sentences and counting the numbers of words, and another task involving the identification of rhyming words in spoken poems. Poorer performance of low than average working memory children was obtained on the recall measure of both tasks. In Study 2, 5- and 6-year-old children heard spoken instructions involving the manipulation of a sequence of objects, and were asked either to perform the instructions or repeat them, in different conditions. The accuracy of performing but not repeating instructions was strongly associated with working memory skills. These results indicate that working memory plays a significant role in typical classroom activities that involve both the storage and mental manipulation of information. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Sensitivity analyses of population projection matrix (PPM) models are often used to identify life-history perturbations that will most influence a population's future dynamics. Sensitivities are linear extrapolations of the relationship between a population's growth rate and perturbations to its demographic parameters. Their effectiveness depends on the validity of the assumption of linearity. Here we assess whether sensitivity analysis is an appropriate tool to investigate the effect of predation by cats on the population growth rates of their avian prey. We assess whether predation by cats leads to non-linear effects on population growth and compare population growth rates predicted by sensitivity analysis with those predicted by a non-linear simulation. For a two-stage, age-classified House Sparrow Passer domesticus PPM slight non-linearity arose when PPM elements were perturbed, but perturbation to the vital rates underlying the matrix elements had a linear impact on population growth rate. We found a similar effect with a slightly larger three-stage, age-classified PPM for a Winter Wren Troglodytes troglodytes population perturbed by cat predation. For some avian species, predation by cats may cause linear or only slightly nonlinear impacts on population growth rates. For these species, sensitivity analysis appears to be a useful conservation tool. However, further work on multiple perturbations to avian prey species with more complicated life histories and higher-dimension PPM models is required. [ABSTRACT FROM AUTHOR]

Naturally occurring stable isotopes in foodwebs can be used to determine the relative contributions of endogenous and exogenous nutrients to avian eggs in cases where birds move between isotopically distinct biomes or habitats to breed. We measured δ13C and δ15N values in somatic muscle tissues and eggs of Barrow's goldeneye (Bucephala islandica) together with those isotope values in amphipods from wetlands used by birds breeding on the Chilcotin Plateau in central British Columbia, Canada. Females that had recently arrived on the breeding grounds had muscle tissue isotope values similar to those found in coastal wintering birds and were considerably more enriched in 13C than were samples from local foodwebs. However, δ15N values of amphipods were highly variable among wetlands, resulting in a nondistinct exogenous δ15N endpoint for our dual-isotope mixing model. Therefore, we only used the model based on δ13C values to estimate nutrient sources to eggs. In 2000, first-laid eggs were more enriched in both isotopes than fourth- or eighth-laid eggs. Considerable endogenous protein input to egg yolk and albumen was detected for the first laid egg (yolk: range = 0-92.7%, median = 23.7%; albumen: range = 0-78.6%, median = 28.7%) with less endogenous contribution of somatic lipids (first egg: range = 0-100%, median = 4.9%). Using archived tissue samples of muscle and developing ovarian follicles from birds collected in 1993-1994, we found no δ13C isotopic evidence for endogenous protein contribution to egg yolk. Our results demonstrate the utility of the stable isotope approach in cases where isotopic endpoints are well established. Barrow's goldeneye showed a mixed strategy of endogenous vs. exogenous nutrient allocation to reproduction that varied by individual females, laying order, and year. We encourage managers to use this approach to quantify nutrient allocations from various biomes to reproduction in waterfowl to better understand the importance of wintering sites to reproduction. [ABSTRACT FROM AUTHOR]

The article presents a study of animal brood and clutch survival model discriminating correlated and random mortality. It highlights the nature of death rate induced by weather and predation which prohibits the assessment of population sustainability and demography. It also outlines the success of breeding, amalgamation and the Mayfield method.

As a result of the events of 9/11, chemical weapons contamination has become a serious consideration. What has become apparent is that most water supply and distribution systems are vulnerable because of their expanse and accessibility. Although there now is recognition of this vulnerability, little is known about threat scenarios, acute concentrations, and how to detect an assault quickly enough to take emergency response. This study was undertaken to determine whether the new technology of photoionization/mass spectrometry could provide early detection of credible threats. This article discusses short-term acute levels and shows that these levels can be reached for credible threats. New instrumentation for chemical weapons contamination screening is simple and fast to use, detects at subacute concentrations, and gives automated red/green light indications with low false-negative and false-positive rates. Increased terrorist activity is raising concerns about the safety of water supplies. Early warning systems that are accurate and fast are needed to deploy effective strategies for rapid response. A new analyzer based on photoionization (PI) and quadrupole ion trap, time-of-flight (QitTof) mass spectrometry (MS) offers high-speed, high-throughput screening and molecular identification of chemical weapons threats and other hazardous compounds. A growing number of municipalities and government facilities are adopting this new screening instrumentation to help safeguard public drinking water. This article reviews the strategy being taken by cities such as Phoenix, Ariz., to develop an early warning capability based on the PI/QitTof MS screening technology. The screening technology can detect a wide range of compounds at subacute concentrations with no sample preparation and a sampling cycle time of about 45 s. [ABSTRACT FROM AUTHOR]

We use observed CO2:CO correlations in Asian outflow from the TRACE-P aircraft campaign (February–April 2001), together with a three-dimensional global chemical transport model (GEOS-CHEM), to constrain specific components of the east Asian CO2 budget including, in particular, Chinese emissions. The CO2/CO emission ratio varies with the source of CO2 (different combustion types versus the terrestrial biosphere) and provides a characteristic signature of source regions and source type. Observed CO2/CO correlation slopes in east Asian boundary layer outflow display distinct regional signatures ranging from 10–20 mol/mol (outflow from northeast China) to 80 mol/mol (over Japan). Model simulations using best a priori estimates of regional CO2 and CO sources from Streets et al. [2003] (anthropogenic), the CASA model (biospheric), and Duncan et al. [2003] (biomass burning) overestimate CO2 concentrations and CO2/CO slopes in the boundary layer outflow. Constraints from the CO2/CO slopes indicate that this must arise from an overestimate of the modeled regional net biospheric CO2 flux. Our corrected best estimate of the net biospheric source of CO2 from China for March–April 2001 is 3200 Gg C/d, which represents a 45% reduction of the net flux from the CASA model. Previous analyses of the TRACE-P data had found that anthropogenic Chinese CO emissions must be ∼50% higher than in Streets et al.'s [2003] inventory. We find that such an adjustment improves the simulation of the CO2/CO slopes and that it likely represents both an underreporting of sector activity (domestic and industrial combustion) and an underestimate of CO emission factors. Increases in sector activity would imply increases in Chinese anthropogenic CO2 emissions and would also imply a further reduction of the Chinese biospheric CO2 source to reconcile simulated and observed CO2 concentrations., Engineering and Applied Sciences

Ground and airborne measurements of CO, ozone, and aerosols were obtained in the northeastern (NE) Pacific troposphere during 9 March–31 May 2001 as part of the PHOBEA-II project (Photochemical Ozone Budget of the Eastern North Pacific Atmosphere). The GEOS-CHEM global three-dimensional model of tropospheric chemistry was used for flight planning, as well as for data analysis after the field mission to examine the origin of CO and ozone over the NE Pacific. The model successfully reproduces the observed CO levels, their temporal variability, and vertical gradients, strongly suggesting a good understanding of the sources, transport and chemistry of CO in the NE Pacific. For ozone the model underestimates mean surface observations by 8 ppbv, overestimates aircraft profiles by 5 ppbv, and does not reproduce the temporal variability of the observations. Possible explanations for model error in the ozone simulation are discussed. We find a pervasive influence of Asian and European anthropogenic sources on the levels of CO in the NE Pacific troposphere. In the 0–6 km column over our surface site, Asian and European emissions account for 33% (42 ppbv) and 15% (21 ppbv) of CO, respectively. Asian and European emissions are responsible for smaller fractions of the 0–6 km ozone column, 12% (5 ppbv) and 5% (2 ppbv), respectively. The full influence of Asian emissions (including secondary ozone production by export of its precursors) approaches 16% of ozone. The model successfully captures three intercontinental transport events observed during the PHOBEA-II campaign: one at the surface and two in the free troposphere. While all three events were characterized by large CO enhancements (by 20–40 ppbv), only one case showed significant ozone enhancement (by 20 ppbv), induced by high-latitude transport of Asian pollution mixed in with stratospheric ozone., Engineering and Applied Sciences

We use tropospheric NO2 columns from the Global Ozone Monitoring Experiment (GOME) satellite instrument to derive top-down constraints on emissions of nitrogen oxides (NOx ≡ NO + NO2), and combine these with a priori information from a bottom-up emission inventory (with error weighting) to achieve an optimized a posteriori estimate of the global distribution of surface NOx emissions. Our GOME NO2 retrieval improves on previous work by accounting for scattering and absorption of radiation by aerosols; the effect on the air mass factor (AMF) ranges from +10 to −40% depending on the region. Our AMF also includes local information on relative vertical profiles (shape factors) of NO2 from a global 3-D chemical transport model (GEOS-CHEM); assumption of a globally uniform shape factor, as in most previous retrievals, would introduce regional biases of up to 40% over industrial regions and a factor of 2 over remote regions. We derive a top-down NOx emission inventory from the GOME data by using the local GEOS-CHEM relationship between NO2 columns and NOx emissions. The resulting NOx emissions for industrial regions are aseasonal, despite large seasonal variation in NO2 columns, providing confidence in the method. Top-down errors in monthly NOx emissions are comparable with bottom-up errors over source regions. Annual global a posteriori errors are half of a priori errors. Our global a posteriori estimate for annual land surface NOx emissions (37.7 Tg N yr−1) agrees closely with the GEIA-based a priori (36.4) and with the EDGAR 3.0 bottom-up inventory (36.6), but there are significant regional differences. A posteriori NOx emissions are higher by 50–100% in the Po Valley, Tehran, and Riyadh urban areas, and by 25–35% in Japan and South Africa. Biomass burning emissions from India, central Africa, and Brazil are lower by up to 50%; soil NOx emissions are appreciably higher in the western United States, the Sahel, and southern Europe., Engineering and Applied Sciences

The article describes the case of an 86-year-old Hispanic woman with Tokutsobe cardiomyopathy who experienced sinoatrial arrest. The patient presented to the emergency department with anterolateral ST elevation, dyspnea and minimal chest pain. Medical management of Tokutsobe cardiomyopathy included treatment of arrythmic substrate during anticipated normalization of ejection fraction.

Background and Aim of Study: The convergent procedure (CVP) is a hybrid ablation technique via a subxiphoid incision that has recently emerged as a treatment option for non-paroxysmal atrial fibrillation (npAF). By combining endocardial and epicardial ablation into a simultaneous or staged procedure, the pulmonary vein and posterior left atrium can be isolated with transmural lesion sets while minimizing the risk of proarrhythmic gaps that are a known limitation with endocardial linear lesion sets. We reviewed the 12-month outcomes in patients who underwent CVP compared to those who underwent endocardial catheter ablation (CA) and surgical ablation (SA)., Methods: A literature search was conducted using the PubMed database for publications related to CVP. Selected studies included detailed 12-month follow-up of patients, patient characteristics, periprocedural complications, use of antiarrhythmic drugs (AADs), and monitoring method., Results: Five studies with 340 patients who underwent CVP between January 2009 and March 2017 were selected for this review. A total of 8.5% of patients had paroxysmal AF (pAF), 42.2% had persistent AF (peAF), and 49.1% had long-standing persistent AF (lspAF). At 12 months, 81.9% of patients were in sinus rhythm, while 54.1% of patients were in sinus rhythm while not taking AADs. The overall complication rate was 10%., Conclusion: CVP had better 1-year efficacy in eliminating AF when compared to CA. However, SA, specifically the Cox Maze IV, had lower rates of AF recurrence in the npAF patient population. Despite its promising 1-year efficacy rates, the periprocedural complication rate for CVP was significantly higher than both CA and SA., (© 2020 Wiley Periodicals, Inc.)