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The Winchcombe meteorite fell on 28th February 2021 in Gloucestershire, UK. As the most accurately recorded carbonaceous chondrite fall, the Winchcombe meteorite is an opportunity to link a tangible sample of known chemical constitution to a specific region of the solar system whose chemistry can only be otherwise predicted or observed remotely. Winchcombe is a CM carbonaceous chondrite, a group known for their rich and varied abiotic organic chemistry. The rapid collection of Winchcombe provides an opportunity to study a relatively terrestrial contaminant-limited meteoritic organic assemblage. The majority of the organic matter in CM chondrites is macromolecular in nature and we have performed non-destructive and destructive analyses of Winchcombe by Raman spectroscopy, online pyrolysis-gas chromatography (pyrolysis-GC-MS), and stepped combustion. The Winchcombe pyrolysis products were consistent with a CM chondrite, namely aromatic and polycyclic aromatic hydrocarbons, sulfur-containing units including thiophenes, oxygen containing units such as phenols and furans, and nitrogen-containing units such as pyridine; many substituted/alkylated forms of these units were also present. The presence of phenols in the online pyrolysis products indicated only limited influence from aqueous alteration, which can deplete the phenol precursors in the macromolecule when aqueous alteration is extensive. Raman spectroscopy and stepped combustion also generated responses consistent with a CM chondrite. The pyrolysis-GC-MS data is likely to reflect the more labile and thermally sensitive portions of the macromolecular materials while the Raman and stepped combustion data will also reflect the more refractory and non-pyrolyzable component, hence we accessed the complete macromolecular fraction of the recently fallen Winchcombe meteorite and revealed a chemical constitution that is similar to other meteorites of the CM group.

MRS can provide high accuracy in the diagnosis of childhood brain tumours when combined with machine learning. A feature selection method such as principal component analysis is commonly used to reduce the dimensionality of metabolite profiles prior to classification. However, an alternative approach of identifying the optimal set of metabolites has not been fully evaluated, possibly due to the challenges of defining this for a multi‐class problem. This study aims to investigate metabolite selection from in vivo MRS for childhood brain tumour classification. Multi‐site 1.5 T and 3 T cohorts of patients with a brain tumour and histological diagnosis of ependymoma, medulloblastoma and pilocytic astrocytoma were retrospectively evaluated. Dimensionality reduction was undertaken by selecting metabolite concentrations through multi‐class receiver operating characteristics and compared with principal component analysis. Classification accuracy was determined through leave‐one‐out and k‐fold cross‐validation. Metabolites identified as crucial in tumour classification include myo‐inositol (P < 0.05, AUC = 0 . 81 ± 0 . 01 ), total lipids and macromolecules at 0.9 ppm (P < 0.05, AUC = 0 . 78 ± 0 . 01 ) and total creatine (P < 0.05, AUC = 0 . 77 ± 0 . 01 ) for the 1.5 T cohort, and glycine (P < 0.05, AUC = 0 . 79 ± 0 . 01 ), total N‐acetylaspartate (P < 0.05, AUC = 0 . 79 ± 0 . 01 ) and total choline (P < 0.05, AUC = 0 . 75 ± 0 . 01 ) for the 3 T cohort. Compared with the principal components, the selected metabolites were able to provide significantly improved discrimination between the tumours through most classifiers (P < 0.05). The highest balanced classification accuracy determined through leave‐one‐out cross‐validation was 85% for 1.5 T 1H‐MRS through support vector machine and 75% for 3 T 1H‐MRS through linear discriminant analysis after oversampling the minority. The study suggests that a group of crucial metabolites helps to achieve better discrimination between childhood brain tumours.

In situ resource utilisation (ISRU) refers to the extraction and use of local materials, and numerous ISRU techniques have been proposed for use on the Moon. Hydrogen reduction of iron oxide-bearing minerals in the lunar regolith, such as ilmenite, has long been suggested as a potential method for producing water on the Moon to support exploration. Generally, reduction of lunar regolith has been proposed and tested in gas-flowing systems which utilise pumps to re-circulate gases (herein described as dynamic systems), and have been trialled in terrestrial laboratory and simulated environments. However, such technologies have yet to be validated on the lunar surface. An alternative to the dynamic reactor is a static system which utilises a cold finger to condense water from the vapour phase, negating the need for a more complex system where gases are continuously pumped away. The PROSPECT Sample Processing and Analysis (ProSPA) instrument is one such static system that is to be used to measure volatiles in the lunar regolith as a payload onboard the Luna-27 lander. Previous work using a breadboard model of ProSPA led to the development and optimisation of a procedure for extracting water from ilmenite. The present work describes the application of these procedures to the reduction of a lunar simulant (NU-LHT-2M), a lunar meteorite (NWA 12592), and two Apollo soils (10084 and 60500). Three 45 ​mg samples of each material type were reacted in a furnace at 1000 ​°C for 4 ​h in the presence of approximately 420 ​mbar of hydrogen. All samples reduced to some extent, with the Apollo mare soil (10084) producing the highest average yield of 0.94 ​wt % O2; this compares favourably to the yields of ~3–4 ​wt % O2 by other more optimised demonstrations of O2 extraction from Apollo soils. Samples with higher ilmenite content produced higher yields, however, pyroxene and olivine within the samples also showed some minor reduction. The results demonstrate that a static system such as ProSPA is capable of reducing lunar regolith of various compositions and producing measurable yields of water. The technique is therefore appropriate for performing in situ resource utilisation experiments at the lunar surface. The simple and small scale technique is also appropriate for use in evaluating the grade of potential feedstock for the production of water by hydrogen reduction on the lunar surface.

The reactions of [M(η3-C3H5)Br(CO)2(NCMe)2] (M = Mo, W) or [Mo(η3-C3H5)Br(CO)2(PMe2Ph)2] with Na[H2B(mt)2] (mt = methimazolyl) affords the complexes [M(η3-C3H5)(CO)2{κ3-H,S,S′-H2B(mt)2}], the 3-centre, 2-electron B–H–M interaction of which was found to be inert with respect to opening under mild conditions, while more forcing conditions (heating with PMe2Ph) resulted in cleavage of the entire allyl and borate ligands to form [Mo(CO)3(PMe2Ph)3]. In contrast, the reaction of [Mo(η3-C3H5)Br(CO)2(NCMe)2] with Na[H2B(pz)2] affords either [Mo(η3-C3H5)(CO)2{κ3-H,N,N′-H2B(pz)2}] or (more likely) [Mo(η3-C3H5)(CO)2(NCMe){κ2-N,N′-H2B(pz)2}] which in turn reacts with phosphines to provide [[Mo(η3-C3H5)(CO)2(PPhR2){κ2-N,N′-H2B(pz)2}] (R = Me, Ph). The reactions discussed indicate the propensity for 3-centre, 2-electron B–H–Mo interactions increases in the order H2B(pz)2 < H2B(pz*)2 < H2B(mt)2 (pz* = 3,5-dimethypyrazolyl).

The ESA-ROSCOSMOS mission, Luna-27, scheduled for launch in 2023, includes a payload known as PROSPECT that is intended for sampling the polar lunar regolith through drilling, with subsequent analyses of the retrieved material. One of the aims of the analytical module, ProSPA, which is being developed at The Open University, is to identify and quantify the volatiles present in the extracted sample that are released by heating from ambient up to 1000 °C and analyzed by the mass spectrometers to assess their potential for in-situ resource utilization. The ProSPA design also includes a provision to test the extraction of water (and its associated oxygen) from lunar regolith by hydrogen reduction. Previous attempts at such extractions generally utilize a flow of hydrogen gas through the feedstock to efficiently extract water. However, in ProSPA, samples would be processed in a static mode, which leads to concerns that the reaction may be suppressed by inefficient removal of water vapor above the regolith. A first order theoretical assessment of the diffusion of gases in such a system was performed and suggested that water can diffuse through the system at an acceptable rate and be collected upon a cold finger thus enabling the reaction to proceed. Proof of concept experiments were successfully performed with a ProSPA breadboard using ilmenite samples up to ∼45 mg heated at 900 °C for 60 min. Subsequent heating of the cold finger, in vacuum, released 17 ± 1 μmol water from a 44.7 ± 0.5 mg sample, equating to a calculated yield of 0.6 ± 0.1 wt % oxygen, and a reduction extent of 5.8 ± 0.4%. A sample of mass 11.2 ± 0.5 mg had the greatest calculated yield of 1.4 ± 0.2 wt % oxygen, and this equates to a reduction extent of 12.9 ± 1.5%. SEM analyses of cross-sections of grains showed evidence of a reduction reaction inside the ilmenite grains with some showing greater reduction than others, indicating the reaction is limited by furnace dimensions, reaction kinetics and geometry. The results suggest that the ProSPA ISRU experiment should be capable of producing water, and therefore oxygen, by hydrogen reduction of ilmenite, ultimately this could be a viable technique for producing oxygen from ilmenite-containing lunar regolith with ProSPA.

Water is one of the most vital resources required for future space exploration. By obtaining water from lunar regolith, humans are one step closer to being independent of Earth's resources enabling longer term exploration missions. Hydrogen reduction of ilmenite is often proposed as a technique for producing water on the Moon. ProSPA, a miniature analytical laboratory, will perform reduction of lunar soils as an In-Situ Resource Utilization (ISRU) demonstration on the lunar surface. The technique used by ProSPA will be useful for prospecting payloads with limited mass and power resources. This work considers the development and optimization of an ilmenite (FeTiO3) reduction procedure for use with the ProSPA instrument. It is shown that the reaction can be performed in a static (non-flowing) system, by utilizing a cold finger to collect the water produced from the reaction. Among the investigated parameters an initial H2:FeTiO3 ratio of 1, in this case equating to a hydrogen pressure of 418 mbar, proved to be best for providing maximum yields over 4 h when operating at 1000 °C. Results indicate that a maximum yield of 3.40 ± 0.17 wt % O2 can be obtained at 1000 °C (with a maximum possible yield of 10.5 wt % O2). When operating at higher temperatures of 1100 °C the ilmenite grains undergo a subsolidus reaction resulting in the formation of ferropseudobrookite and higher yields of 4.42 ± 0.18 wt % O2 can be obtained.

The reactions of [M(η3-C3H5)Br(CO)2(NCMe)2] (M = Mo, W) or [Mo(η3-C3H5)Br(CO)2(PMe2Ph)2] with Na[H2B(mt)2] (mt = methimazolyl) affords the complexes [M(η3-C3H5)(CO)2{κ3-H,S,S'-H2B(mt)2}], the 3-centre, 2-electron B-H-M interaction of which was found to be inert with respect to opening under mild conditions, while more forcing conditions (heating with PMe2Ph) resulted in cleavage of the entire allyl and borate ligands to form [Mo(CO)3(PMe2Ph)3]. In contrast, the reaction of [Mo(η3-C3H5)Br(CO)2(NCMe)2] with Na[H2B(pz)2] affords either [Mo(η3-C3H5)(CO)2{κ3-H,N,N'-H2B(pz)2}] or (more likely) [Mo(η3-C3H5)(CO)2(NCMe){κ2-N,N'-H2B(pz)2}] which in turn reacts with phosphines to provide [[Mo(η3-C3H5)(CO)2(PPhR2){κ2-N,N'-H2B(pz)2}] (R = Me, Ph). The reactions discussed indicate the propensity for 3-centre, 2-electron B-H-Mo interactions increases in the order H2B(pz)2H2B(pz*)2H2B(mt)2 (pz* = 3,5-dimethypyrazolyl).

Jbilet Winselwan is one of the largest CM carbonaceous chondrites available for study. Its light, major, and trace elemental compositions are within the range of other CM chondrites. Chondrules are surrounded by dusty rims and set within a matrix of phyllosilicates, oxides, and sulfides. Calcium‐ and aluminum‐rich inclusions (CAIs) are present at ≤1 vol% and at least one contains melilite. Jbilet Winselwan is a breccia containing diverse lithologies that experienced varying degrees of aqueous alteration. In most lithologies, the chondrules and CAIs are partially altered and the metal abundance is low (

Carbon and nitrogen data from stepped combustion analysis of eight angrites, seven eucrites, and two diogenites, alongside literature data from a further nine eucrites and two diogenites, have been used to assess carbon and nitrogen incorporation and isotope fractionation processes on the angrite parent body (APB), for comparison with volatile behavior on the HED parent body (4 Vesta). A subset of the angrite data has been reported previously (Abernethy et al. 2013). Two separate families of volatile components were observed. They were (1) moderately volatile material (MVM), mostly combusting between ~500 and 750 °C and indistinguishable from terrestrial contamination and (2) refractory material (RM), mainly released above 750 °C and thought to be carbon (as math formula) and nitrogen (as N2 or math formula) dissolved within the silicate lattice, fitting with the slightly oxidized (~IW to IW+2) angrite fO2 conditions. Isotopic fractionation trends for carbon and nitrogen within the plutonic and basaltic (quenched) angrites suggest that the behavior of the two volatile elements is loosely coupled, but that the fractionation process differs between the two angrite subgroups. Comparison with results from eucrites and diogenites implies similarities between speciation of carbon and nitrogen on 4 Vesta and the APB, with the latter being more enriched in volatiles than the former.

Sporopollenin, which forms the outer wall of pollen and spores, contains a chemical signature of ultraviolet-B flux via concentrations of UV-B absorbing compounds (UACs), providing a proxy for reconstructing UV irradiance through time. Although Fourier transform infrared (FTIR) spectroscopy provides an efficient means of measuring UAC concentrations, nitrogen-containing compounds have the potential to bias the aromatic and hydroxyl bands used to quantify and standardise UAC abundances. Here, we explore the presence and possible influence of nitrogen in UV reconstruction via an FTIR study of Lycopodium spores from a natural shading gradient. We show that the UV-sensitive aromatic peak at 1510 cm− 1 is clearly distinguishable from the amide II peak at 1550 cm− 1, and the decrease in aromatic content with increased shading can be reconstructed using standardisation approaches that do not rely on the 3300 cm− 1 hydroxyl band. Isolation of the sporopollenin results in the loss of nitrogen-related peaks from the FTIR spectra, while the aromatic gradient remains. This confirms the lack of nitrogen in sporopollenin and its limited potential for impacting on palaeo-UV reconstructions. FTIR is therefore an appropriate tool for quantifying UACs in spores and pollen, and information on UV flux should be obtainable from fossil or processed samples.

Summary Background Escherichia coli causes more than one-third of the bacteraemia cases in England each year, and the incidence of these infections is increasing. Aim To determine the underlying risk factors associated with E. coli bacteraemia. Methods A three-month enhanced sentinel surveillance study involving 35 National Health Service hospitals was undertaken in the winter of 2012/13 to collect risk factor information and further details on the underlying source of infection to augment data already collected by the English national surveillance programme. Antimicrobial susceptibility results for E. coli isolated from blood and urine were also collected. Findings A total of 1731 cases of E. coli bacteraemia were included. The urogenital tract was the most frequently reported source of infection (51.2% of cases) with previous treatment for a urinary tract infection being the largest independent effect associated with this infection source. Half of all patients had previous healthcare exposure in the month prior to the bacteraemia with antimicrobial therapy and urinary catheterization being reported in one-third and one-fifth of these patients, respectively. Previous healthcare exposure was associated with a higher proportion of antibiotic non-susceptibility in the blood culture isolates ( P =0.001). Conclusion Analysis of risk factors suggests the potential benefit of community- and hospital-related interventions, especially the better use of urinary catheters and improved antibiotic management of urinary tract infections. As part of the latter strategy, antibiotic resistance profiles need to be closely monitored to ensure that treatment guidelines are up to date to limit inappropriate empiric therapy.

The reaction of [RuCl2(PPh3)3] with K[H2B(pz)2] (pz = pyrazol-1-yl) in tetrahydrofuran at room temperature provides the known hydrotris(pyrazolyl)borate complex [RuH(PPh3)2{HB(pz)3}] (1b) via pyrazole scrambling. In contrast, the reaction of [RuCl2(PPh3)3] with K[H2B(pz)2] in methanol does not, as previously reported, provide [Ru(PPh3)2{H2B(pz)2}2] but, rather, a mixture of the complexes [RuX(PPh3)2{κ3O,N,N′-(MeO)2B(pz)2}] (X = H (2a), Cl (2b)) and ttt-[RuCl2(Hpz)2(PPh3)2] (3), each of which have been structurally characterized. Although the resulting bulk admixtures of 2a,b have so far proved inseparable, treatment with mercuric chloride cleanly converts the 2a component to 2b. Heating 2b with 1,2-bis(dicyclohexylphosphino)ethane (dcpe) results in substitution of both phosphine ligands and the formation of [RuCl(dcpe){κ3O,N,N′-(MeO)2B(pz)2}] (4) in which the ruthenium−ether linkage is ultimately retained.

SUMMARYDespite increasing migration, the impact of HIV epidemics from Central and Eastern Europe (C&EE) on the UK HIV epidemic remains small. C&EE-born adults comprised 1·2% of adults newly diagnosed with HIV in the UK between 2000 and 2007. Most C&EE-born women probably acquired their infection heterosexually in C&EE. In contrast, 59% of C&EE-born men reported sex with men, half of whom probably acquired their infection in the UK. Previously undiagnosed HIV prevalence in C&EE-born sexual-health-clinic attendees was low (2007, 0·5%) as was overall HIV prevalence in C&EE-born women giving birth in England (2007

The high-yield product of the reaction of [RuCl2(dmso)4] (dmso = dimethylsulfoxide) with Na[HB(mt)3] (mt = methimazolyl) is not, as reported, the complex [RuCl(dmso)2{κ3-S,S′,S′′-HB(mt)3}] but rather the isomeric [RuCl(dmso)2{κ3-H,S,S′-HB(mt)3}], which features a three-center, two-electron B−H−Ru interaction, as also found for the complex [RuH(PPh3)2{κ3-H,S,S′-H2B(mt)2}], which results from [RuHCl(PPh3)3] and Na[H2B(mt)2].

A side-product that accompanies the synthesis of the widely utilized starting material TpRu(PPh3)2Cl (Tp = hydridotris(pyrazolyl)borate) has been identified as the complex ClTpRu(PPh3)2H (ClTp = chlorotris(pyrazolyl)borate), which provides a rare example of a boron-halogenated pyrazolylborate ligand. The reaction of ClTpRu(PPh3)2H with dichloromethane or chloroform quantitatively produce ClTpRu(PPh3)2Cl.

SUMMARY 1Here we classify selected European hydrophytes into ‘attribute groups’ based on the possession of homogenous sets of characteristics, and explore the correspondence between these attribute groups, or individual attributes, and habitat use.2Non‐hierarchical clustering was used to assign 120 species to twenty groups based on a matrix of categorical scores for literature‐ and field‐derived information covering seventeen intrinsic morphological and life‐history traits. Subdivision of some of these traits produced a total of 58 attributes (i.e. modalities). The robustness of this classification was confirmed by a high rate of reclassification (92%) under multiple discriminant analysis (MDA). The phylogenetic contribution was explored using ordination methods with taxonomy at family level acting as a covariable.3Our approach differed from earlier classifications based on growth or life form because we regarded growth form plasticity as a property of the species and its range of growing conditions, rather than of each individual population, and we considered additional (e.g. regenerative) traits. However, some conventional life form groups were preserved (i.e. utricularids, isoetids, hydrocharids and lemnids).4Some parallels existed with established theory on terrestrial plant growth strategies, but we used strictly intrinsic attributes relevant specifically to hydrophytes and our groups could not be decomposed into three or four primary strategies. Only finer levels of partitioning appear to be of fundamental and applied ecological relevance in hydrophytes.5A principal components analysis ordination based on 26 attributes related to physical habitat utilization separated species and their attribute groups along axes relating to: (a) flow, substratum grade and organic matter content, scour frequency, and sedimentation; and (b) depth, water level stability and biotic disturbance. A MDA applied to species ordination scores indicated only a modest overall correspondence between attribute groups and habitat use (54% correct reclassification). Poor reclassification was the result of intergroup overlap (indicating alternative sets of attributes for a given habitat) or high intragroup variance in habitat utilization (indicating commonality of attributes between different habitats). These results are interpreted in terms of trade‐offs between resistance and resilience traits, ‘functional plasticity’ in traits, phylogenetic dependence in some groups and methodological constraints. The predictive potential of hydrophyte groups and their limitations are discussed.6Redundancy analysis revealed a highly significant correlation between traits and habitat use (P < 0.01). Our attribute matrix explained 72% of variation in physical habitat use with eight attributes (i.e. turions, anchored emergent leaves, high or low body flexibility, high root:shoot biomass ratio, free‐floating surface or free‐floating submerged growth form, and annual life history) explaining half of this variation.7Most attributes were mapped in accordance with habitat template predictions, although tests were confounded by the underlying correlation between spatial and temporal heterogeneity. The main features were: (a) a trade‐off between resistance‐type traits (related to stream lining, flexibility and anchorage) in more spatially heterogenous riverine and littoral zone habitats, and resilience type traits (i.e. turions, very small body size and free‐floating growth forms) in spatially simple, rarely disturbed habitats, such as backwaters and canals; and (b) a shift from high investment competitive traits with a low reproductive output in deep stable habitats to classically ruderal and desiccation resistance traits in shallow fluctuating habitats.

The syntheses of a range of poly(methimazolyl)borate -ligated nitrosyl complexes of tungsten and molybdenum are reported, the characterization of which includes the crystal structure determinations of the compounds [W(NO)(CO)(2){k(3)-S,S',S''-HB(mt)(3)}], [W(NO)(CO)(2)(PPh3){k(2)-S,S'-H2B(mt)(2)}], and [Mo(NO-)(CO)(2) {k(3)-H,S,S'-H2B(mt)(2)}] (mt = methimazoyl). The reaction of [W(NO)(CO)(3)(PPh3)(2)]PF6 with Na[HB(mt)(3)] and Na[H2B(mt)(2)}] provides respectively [W(NO)(CO)(2)[HB(mt)(3)] and [W(NO)(CO)(2)(PPh3){k(2_) S,S'-H2B(mt)(2)}]. The complexes [M(NO)(CO)(2){HB(mt)(3)}] and [M(NO)(CO)(2){k(3)-H,S,S'-H2B(mt)(2)}] (M = W, Mo) arise from the reactions of Na[M(CO)(3){H2B(mt)(2)}] with N-methyl-N-nitrosotoluenesulfonamide. The molybdenum complex [Mo(NO)(CO)(2){HB(mt)(3)}] is also obtained unexpectedly from the reaction of [MO(eta(3)-C3H5)(CO)(2){HB(mt)(3)}] with [NO]BF4.

A 12-year-old girl with protracted tuberculous meningitis received standard chemotherapy and dexamethasone and had a progressive cerebrospinal fluid neutrophilia, raised protein and depressed glucose levels. Her temperature was raised for 5 months until a second course of dexamethasone was given. At week 15, multiple tuberculomas and hydrocephalus were detected followed by acute hydrocephalus (week 58), which required a ventricular-peritoneal shunt. Tuberculomas resolved after a second course of dexamethasone but recurred 15 months later. Immunological investigations were normal including integrity of the type 1 cytokine pathway. From month 24, interferon-gamma was given subcutaneously (initially 50 microg/m(2)) and continued for 19 months. Within 2 weeks she responded clinically followed by a reduction in inflammatory signs on magnetic resonance imaging scan (but not in the tuberculomas). At month 44, when chemotherapy was stopped, the cerebrospinal fluid/serum albumin quotient was 57x10(-3) (normal

We sought to determine if the velocity of an acute bout of eccentric contractions influenced the duration and severity of several common indirect markers of muscle damage. Subjects performed 36 maximal fast (FST, n = 8: 3.14 rad x s(-1)) or slow (SLW, n = 7: 0.52 rad x s(-1)) velocity isokinetic eccentric contractions with the elbow flexors of the non-dominant arm. Muscle soreness, limb girth, plasma creatine kinase (CK) activity, isometric torque and concentric and eccentric torque at 0.52 and 3.14 rad x s(-1) were assessed prior to and for several days following the eccentric bout. Peak plasma CK activity was similar in SLW (4030 +/- 1029 U x 1(-1)) and FST (5864 +/- 2664 U x 1(-1)) groups, (p0.05). Both groups experienced similar decrement in all strength variables during the 48 hr following the eccentric bout. However, recovery occurred more rapidly in the FST group during eccentric (0.52 and 3.14 rad x s(-1)) and concentric (3.14 rad x s(-1)) post-testing. The severity of muscle soreness was similar in both groups. However, the FST group experienced peak muscle soreness 48 hr later than the SLW group (24 hr vs. 72 hr). The SLW group experienced a greater increase in upper arm girth than the FST group 20 min, 24 hr and 96 hr following the eccentric exercise bout. The contraction velocity of an acute bout of eccentric exercise differentially influences the magnitude and time course of several indirect markers of muscle damage.

The reactions of [M( CC6H2Me3-2,4,6)X(CO)2(L)2] (M = Mo, W; X = Cl, Br; L = pyridine, 3,5-dimethylpyrazole) with Na[H2B(mt)2] (mt = methimazolyl) are metal dependent, providing either the alkylidyne complex [Mo( CC6H2Me3-2,4, 6)(CO)2{κ3-H,S,S′-H2B(mt)2}] or the bis(chelate) complex [W(CO){κ2-S,S′-H2B(mt)2}{κ3-H,S,S′-H2B(mt)2}], the latter featuring both bi and tridentate coordination modes for the H2B(mt)2 ligand.

Chronic exposure to benzene results in progressive decline of hematopoietic function and may lead to the onset of various disorders, including aplastic anemia, myelodysplastic syndrome, and leukemia. Damage to macromolecules resulting from benzene metabolites and misrepair of DNA lesions may lead to changes in hematopoietic stem cells (HSCs) that give rise to leukemic clones. We have shown previously that male mice exposed to benzene by inhalation were significantly more susceptible to benzene-induced toxicities than females. Because HSCs are targets for benzene-induced cytotoxicity and genotoxicity, we investigated DNA damage responses in HSC from both genders of 129/SvJ mice after exposure to 1,4-benzoquinone (BQ) in vitro or benzene in vivo. 1,4-BQ is a highly reactive metabolite of benzene that can cause cellular damage by forming protein and DNA adducts and producing reactive oxygen species. HSCs cultured in the presence of 1,4-BQ for 24 hours showed a gender-independent, dose-dependent cytotoxic response. RNA isolated from 1,4-BQ-treated HSCs and HSCs from mice exposed to 100 ppm benzene by inhalation showed altered expression of apoptosis, DNA repair, cell cycle, and growth control genes compared with unexposed HSCs. Rad51, xpc, and mdm-2 transcript levels were increased in male but not female HSCs exposed to 1,4-BQ. Males exposed to benzene exhibited higher mRNA levels for xpc, ku80, ccng, and wig1. These gene expression differences may partially explain the gender disparity in benzene susceptibility. HSC culture systems such as the one used here will be useful for testing the hematotoxicity of various substances, including other benzene metabolites.

Chronic human exposure to benzene has been linked to several hematopoietic disorders, including leukemia and lymphomas. Certain benzene metabolites, including benzoquinone (BQ), are genotoxic and mutagenic. Bone marrow stem cells are targets for benzene-induced cytotoxicity and DNA damage that could result in changes to the genome of these progenitor cells, thereby leading to hematopoietic disorders and cancers. Human bone marrow CD34(+) hematopoietic progenitor cells (HPC) were exposed in vitro to 1,4-BQ to assess cytotoxicity, genotoxicity, and DNA damage responses and the molecular mechanisms associated with these events. CD34(+) HPC from 10 men and 10 women were exposed to 0, 1, 5, 10, 15, or 20 microM of 1,4-BQ and analyzed 72 h later. Apoptosis and cytotoxicity were dose-dependent, with exposure to 10 microM 1,4-BQ resulting in approximately 60% cytotoxicity relative to untreated controls. A significant increase in the percentage of micronucleated CD34(+) cells was detected in cultures treated with 1,4-BQ. In addition, the p21 mRNA level was elevated in 1,4-BQ-treated cells, suggesting that human CD34(+) cells utilize the p53 pathway in response to 1,4-BQ-induced DNA damage. However, there were no significant changes in mRNA levels of the DNA repair genes ku80, rad51, xpa, xpc, and ape1 as well as p53 following treatment with 1,4-BQ. Although interindividual variations were evident in the cellular response to 1,4-BQ, there was no gender difference in the response overall. These results show that human CD34(+) cells are sensitive targets for 1,4-BQ toxicity that use the p53 DNA damage response pathway in response to genotoxic stress. Human CD34(+) HPC will be useful for testing the toxicity of other benzene metabolites and various hematotoxic chemicals.

Benzene, a carcinogen that induces chromosomal breaks, is strongly associated with leukemias in humans. Possible genetic determinants of benzene susceptibility include proteins involved in repair of benzene-induced DNA damage. The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), encoded by Prkdc, is one such protein. DNA-PKcs is involved in the nonhomologous end-joining (NHEJ) pathway of DNA double-strand break (DSB) repair. Here we compared the toxic effects of benzene on mice (C57BL/6 and 129/Sv) homozygous for the wild-type Prkdc allele and mice (129/SvJ) homozygous for a Prkdc functional polymorphism that leads to diminished DNA-PK activity and enhanced apoptosis in response to radiation-induced damage. Male and female mice were exposed to 0, 10, 50, or 100 ppm benzene for 6 h/d, 5 d/week for 2 weeks. Male mice were more susceptible to benzene toxicity compared with females. Hematotoxicity was evident in all male mice but was not seen in female mice. We observed similar, large increases in both micronucleated erythrocyte populations in all male mice. Female mice had smaller but significant increases in micronucleated cells. The p53-dependent response was induced in all strains and genders of mice following benzene exposure, as indicated by an increase in p21 mRNA levels in bone marrow that frequently corresponded with cell cycle arrest in G2/M. Prkdc does not appear to be a significant genetic susceptibility factor for acute benzene toxicity. Moreover, the role of NHEJ, mediated by DNA-PK, in restoring genomic integrity following benzene-induced DSB remains equivocal.

Surveys of 87 sites within nine locations on Scottish agricultural land, during 1995–1997, recorded 335 species of vascular plants and 95 bryophyte species, within 31 recognisable plant communities. Multivariate analysis placed the vegetation into five main vegetation types, with differing plant species richness ( S: number of species per 100 m 2 ). These were upland grassland (mean S = 37); mesotrophic semi-improved grassland (mean S = 25); mire/heath vegetation (mean S = 22); intensive grassland (mean S = 12); and arable land and weed communities, including set-aside (mean S = 9). Management intensity was a good predictor (R 2 = 0.729) of vegetation type, with low intensity being typical of upland grassland, and high intensity typical of arable vegetation. The data were used to develop and test a set of minimal linear models of plant diversity response to land-use changes, operating at field scale, under the agro-geo-climatic conditions of mainland Scotland. The models utilised predictor variables drawn from a suite of functional vegetation attributes, environmental data, and management information. All-plant-species S was well predicted at quadrat level (i.e. within field, excluding margins) by three models with high R 2 values (0.82–0.93) utilising management variables such as crop-type, livestock density, time since last cultivation; vegetation state variables such as bryophyte cover, sward height, litter cover; and environmental variables such as soil P content. Bryophyte S was well predicted by four models with high R 2 values (0.83–0.92). Bryophyte percentage cover was the most important predictor variable in these models. Vascular plant species S was less well predicted than either all-plant-species or bryophytes-only models. The models can be used to assess the implications of land-use change scenarios, and to aid management decisions to help to maintain plant diversity within the Scottish agricultural landscape. © 2002 Published by Elsevier Science B.V.

The purpose of this investigation was to identify characteristics of the muscle protein titin in different athletic populations with increased levels of strength and power relative to non-athletes. Subjects fell into one of four groups: (1) non-athletes (NA) ( n=5), (2) weightlifters (WL) (n=5), (3) powerlifters (PL) (n=5), (4) sprinters (S) (n=5). A one repetition maximum in the squat exercise was performed to assess strength. In addition, countermovement vertical jump trials were performed to assess power capabilities. Peak power (W(peak)) was calculated for the vertical jumps from force plate measurements. From gel electrophoresis analyses of muscle samples, titin-1 (T1) and titin-2 (T2) protein bands were identified, quantified and expressed relative to each other. In addition the relative mobility (R(f)) of T1 and T2 was determined as an estimate of molecular weight. The NA group [%T1=47.8 (5.1), %T2=52.2 (5.1), mean (SE)] had lower T1 and higher T2 percentages than WL [%T1=62.3 (6.6), %T2=37.7 (6.6)], PL [%T1=66.8 (5.0), %T2=33.2 (5.0)] and S [%T1=65.9 (4.9), %T2=34.1 (4.9)] groups (P< or =0.10, preliminary investigation into titin and exercise justifies more liberal alpha level). No significant differences were found in R(f) of T1 or T2 between the groups. This investigation has shown that there is a differential expression of titin protein bands in competitive athletes with increased levels of strength and power in comparison to untrained non-athletic individuals. Some relationships between titin characteristics and athletic performance were observed; however, no conclusions can be made based on these data as to the contribution of titin to strength or power capabilities.

This study characterizes carbon and nitrogen abundances and isotopic compositions in ureilitic fragments of Almahata Sitta. Ureilites are carbon-rich (containing up to 7 wt% C) and were formed early in solar system history, thus the origin of carbon in ureilites has significance for the origin of solar system carbon. These samples were collected soon after they fell, so they are among the freshest ureilite samples available and were analyzed using stepped combustion mass spectrometry. They contained 1.2–2.3 wt% carbon; most showed the major carbon release at temperatures of 600–700 °C with peak values of δ13C from −7.3 to +0.4‰, similar to literature values for unbrecciated (“monomict”) ureilites. They also contained a minor low temperature (≤500 °C) component (δ13C = ca −25‰). Bulk nitrogen contents (9.4–27 ppm) resemble those of unbrecciated ureilites, with major releases mostly occurring at 600–750 °C. A significant lower temperature release of nitrogen occurred in all samples. Main release δ15N values of −53 to −94‰ fall within the range reported for diamond separates and acid residues from ureilites, and identify an isotopically primordial nitrogen component. However, they differ from common polymict ureilites which are more nitrogen-rich and isotopically heavier. Thus, although the parent asteroid 2008TC3 was undoubtedly a polymict ureilite breccia, this cannot be deduced from an isotopic study of individual ureilite fragments. The combined main release δ13C and δ15N values do not overlap the fields for carbonaceous or enstatite chondrites, suggesting that carbon in ureilites was not derived from these sources.

Many symptoms of eccentric muscle damage can be substantially reduced if a similar eccentric bout is repeated within several weeks of the initial bout. The purpose of this study was to determine whether a nondamaging, low repetition, low volume eccentric exercise bout could also provide a protective/adaptive effect. Subjects were assigned to a control (CON), eccentric exercise (ECC), or low volume familiarized eccentric exercise group (LV+ECC). Before the study, the LV+ECC group performed six maximal eccentric contractions during two familiarization sessions. The main eccentric bout targeted the elbow flexor muscle group and consisted of 36 maximal eccentric contractions. Muscle soreness, upper arm girth, elbow angle, creatine kinase activity, isometric torque, and concentric and eccentric torque at 0.52 and 3.14 rad.s-1 were assessed 0, 1, 2, 3, 4, 7, and 10 d postexercise. No evidence of muscle damage was observed as a result of the low volume eccentric bouts. Nevertheless, with the exception of muscle soreness and concentric torque, all variables recovered more rapidly in the LV+ECC group (P Adaptation to eccentric exercise can occur in the absence of significant muscle damage. Exposure to a small number of nondamaging eccentric contractions can significantly improve recovery after a subsequent damaging eccentric bout. Furthermore, this adaptation appears to be mode-specific and not applicable to concentric contractions.

Linyphiid spiders are important generalist predators of insects in agricultural habitats. Their ability to rapidly disperse and colonise disturbed habitats makes them important as a natural form of pest control, often present before other predatory groups arrive. This paper examines the distribution of Erigone atra and E. dentipalpis, which are amongst the commonest linyphiid species to be found on agricultural land in Scotland. The habitat preferences of these species were assessed using abundance and proportion data from 71 independent sites sampled using pitfall traps over 2 years and a selection of repeat first-year sites sampled during the second year, incorporating a range of land-uses from extensive moorland, through grasslands to intensive arable fields. E. atra dominated in autumn sown crops, and E. dentipalpis dominated at the other end of the agricultural management spectrum in low-intensity grasslands. Both species were considered absent from upland and moorland habitats. Linear regression modelling was used to create a model which best estimated the variance in proportions of E. atra in the catch across the sites using a selection of vegetation, soil, management and landscape variables. This model was based on data from 58 sites where Erigone species were abundant and explained 66% of the variation in E. atra. The variables included were increasing vegetation biomass above 50 mm and increasing levels of mixed grazing (both positive), and a combination of increasing plant species richness and vegetation stem density (negative). The efficiency of the model was examined using data from 13 sites which were sampled in the subsequent year to assess the effects of no changes and changes in land-use on the proportions of the two species. Only two sites were considered inaccurate (more than 20% different from the model), suggesting a relatively high level of accuracy. Interaction between the two species was tested for and not found to explain the differences in proportion observed. Comparisons with other studies were carried out, showing similar trends in proportions and in some of the variables identified as important. The influence of specific variables on each species is described in light of possible allometric-type effects, and the importance of these species for conservation and pest control in agriculture is discussed.

SUMMARY 1 Here we classify selected European hydrophytes into ‘attribute groups’ based on the possession of homogenous sets of characteristics, and explore the correspondence between these attribute groups, or individual attributes, and habitat use. 2 Non-hierarchical clustering was used to assign 120 species to twenty groups based on a matrix of categorical scores for literature- and field-derived information covering seventeen intrinsic morphological and life-history traits. Subdivision of some of these traits produced a total of 58 attributes (i.e. modalities). The robustness of this classification was confirmed by a high rate of reclassification (92%) under multiple discriminant analysis (MDA). The phylogenetic contribution was explored using ordination methods with taxonomy at family level acting as a covariable. 3 Our approach differed from earlier classifications based on growth or life form because we regarded growth form plasticity as a property of the species and its range of growing conditions, rather than of each individual population, and we considered additional (e.g. regenerative) traits. However, some conventional life form groups were preserved (i.e. utricularids, isoetids, hydrocharids and lemnids). 4 Some parallels existed with established theory on terrestrial plant growth strategies, but we used strictly intrinsic attributes relevant specifically to hydrophytes and our groups could not be decomposed into three or four primary strategies. Only finer levels of partitioning appear to be of fundamental and applied ecological relevance in hydrophytes. 5 A principal components analysis ordination based on 26 attributes related to physical habitat utilization separated species and their attribute groups along axes relating to: (a) flow, substratum grade and organic matter content, scour frequency, and sedimentation; and (b) depth, water level stability and biotic disturbance. A MDA applied to species ordination scores indicated only a modest overall correspondence between attribute groups and habitat use (54% correct reclassification). Poor reclassification was the result of intergroup overlap (indicating alternative sets of attributes for a given habitat) or high intragroup variance in habitat utilization (indicating commonality of attributes between different habitats). These results are interpreted in terms of trade-offs between resistance and resilience traits, ‘functional plasticity’ in traits, phylogenetic dependence in some groups and methodological constraints. The predictive potential of hydrophyte groups and their limitations are discussed. 6 Redundancy analysis revealed a highly significant correlation between traits and habitat use (P < 0.01). Our attribute matrix explained 72% of variation in physical habitat use with eight attributes (i.e. turions, anchored emergent leaves, high or low body flexibility, high root:shoot biomass ratio, free-floating surface or free-floating submerged growth form, and annual life history) explaining half of this variation. 7 Most attributes were mapped in accordance with habitat template predictions, although tests were confounded by the underlying correlation between spatial and temporal heterogeneity. The main features were: (a) a trade-off between resistance-type traits (related to stream lining, flexibility and anchorage) in more spatially heterogenous riverine and littoral zone habitats, and resilience type traits (i.e. turions, very small body size and free-floating growth forms) in spatially simple, rarely disturbed habitats, such as backwaters and canals; and (b) a shift from high investment competitive traits with a low reproductive output in deep stable habitats to classically ruderal and desiccation resistance traits in shallow fluctuating habitats.

Afebrile seizures in young children may be caused by hyponatraemia—take a dietary history and measure serum electrolytes

Aim—To determine whether neurological deficits are associated with structural anomalies of the brain in very low birthweight (VLBW) infants with subsequent learning disorders but without cerebral palsy, or whether other factors, such as poor early growth, are responsible. Methods—Eighty seven VLBW infants and eight term controls who had been examined at school between the ages of 12 and 13 years, had cranial magnetic resonance imaging (MRI) scans at 15‐17 years of age. Results—Thirty seven (42.5%) of the VLBW children had abnormalities reported on their scans (two porencephaly, 28 periventricular leucomalacia, 24 ventricular dilatation, and 15 thinning of the corpus callosum). No significant diVerences in intelligence quotient, motor clumsiness, or frequency of attention deficit / hyperactivity disorder were observed between those children with MRI lesions and those with normal scans. Quantitative measurements showed the VLBW infants had smaller brains, and a relatively smaller corpus callosum compared with controls. No association between brain measurements and school performance was observed among the VLBW infants. Conclusions—The diYculties experienced by VLBW children at school are unlikely to be the result of perinatal brain injury, but they might to be attributable to the eVects of poor postnatal growth. (Arch Dis Child Fetal Neonatal Ed 1999;81:F116‐F121)

This study investigated the effect of a carbohydrate restriction program on performance in a bout of isoinertial and isokinetic strength exercise. One female and five male subjects (mean +/- SD: age = 20.3 +/- 2.3 years; body mass = 74.6 +/- 11.5 kg; height 177.0 +/- 8.8 cm) performed isoinertial and isokinetic strength exercise under control conditions (no experimental intervention) and after a 2-day carbohydrate restriction program. The carbohydrate restriction program consisted of 60 minutes of cycling at 75% of peak cycle ergometer oxygen consumption (PVO2), followed by four 1-minute bouts at 100% of PVO2, followed by 2 days of reduced carbohydrate intake (1.2 +/- 0.5 g.kg(-1).d(-1)). Isoinertial strength exercise was three sets of squats with a load of 80% of one repetition maximum. Isokinetic strength exercise was five repetitions of leg extensions performed at five different contractile speeds (1.05, 2.09, 3.14, 4.19, and 5.24 rad.s(-1)). The carbohydrate restriction program caused a significant reduction in the number of squat repetitions performed. Torque at 0.52 rad from full extension (T30) was not significantly altered by carbohydrate restriction. Plasma lactate concentration postexercise was significantly lower after carbohydrate restriction. The fact that carbohydrate restriction reduces performance in isoinertial but not isokinetic strength exercise may be due to the different metabolic demands associated with the different exercise protocols used in the two modes of strength exercise.

Detailed knowledge of the biodiversity of spider communities on agricultural land is important both in terms of enhancing pest control and understanding the driving forces influencing nature conservation value. Pitfall traps were used to assess spider species diversity at 71 Scottish agricultural sites between May and September during 1996 and 1997. Land-use varied from intensive arable fields, grasslands and extensive heather (Calluna vulgaris) moorland. Spider species richness (S) was found to decrease significantly as farm management intensity increased. Several linear regression models based on the 1996 data (50 sites) and a selection of plant, soil and landscape variables explained up to 88% of the variation in species richness. Four of these models were used to estimate 1997 species richness (36 sites: 15 repeat and 21 new) and up to 58% of sites were correctly predicted to within ± four species of the actual number caught. As only 60% of the repeat 1997 sites had values of S within four units of their 1996 score, this suggested a relatively high level of model accuracy. Model accuracy increased to 64% when all four models were used for each site, suggesting the individual models should be targeted at specific land-use types. We discuss the relevance of these models for predicting the consequences of changes in agricultural land-use for spider diversity.

Seventeen subjects performed resistance training of the leg extensor and flexor muscle groups two (2/wk) or three (3/wk) times per week. Changes in the relative myosin heavy chain (MHC) isoform contents (I, IIa and IIx) of the vastus lateralis and isometric, isokinetic and squat-lift one-repetition maximum (1 RM) strength were compared between conditions after both a common training period (6 weeks) and number of training sessions (18). After 6 weeks and 18 sessions (9 weeks for the 2/wk group), increments in 1RM strength for the 3/wk and 2/wk groups were similar [effect size (ES) differences approximately 0.3, 3/wk > 2/wk], whereas the 2/wk group presented greater isokinetic (ES differences = 0.3-1.2) and isometric (ES differences approximately 0.7) strength increases than the 3/wk condition. A significant (P < 0.05) increase in MHC IIa percentage was evident for the 2/wk group after 18 sessions. Both training groups exhibited a trend towards a reduction in the relative MHC IIx and an increase in MHC IIa contents (ES range = 0.5-1.24). However, correlations between changes in the strength and MHC profiles were weak (r2: 0.0-0.5). Thus, isometric and isokinetic strength responses to variations in training frequency differed from 1RM strength responses, and changes in strength were not strongly related to alterations in relative MHC content.

OBJECTIVE To investigate the use of a calcium infusion test in the diagnosis and localisation of insulin secreting tumours in children. PATIENTS Three patients with persistent hypoglycaemia of infancy (PHHI). PROCEDURE During planned selective coeliac and mesenteric arteriography, serial samples were taken from a catheter in the right hepatic vein for insulin measurement following the injection of calcium gluconate. RESULTS In all three children, selective intra-arterial calcium stimulation produced a significant rise in plasma insulin and was of value in localising the pancreatic abnormality in one child. In vitro studies on islets of Langerhans isolated from this patient following partial pancreatectomy showed unresponsive intracellular calcium signalling of the cells when stimulated with high extracellular concentrations of glucose and potassium or with sulphonylurea drugs (tolbutamide), but normal responsiveness to increasing extracellular calcium concentrations. CONCLUSIONS The findings suggest a functional abnormality of the calcium channel in PHHI and provide a rationale for the reported efficacy of channel blocking drugs in this condition. The role of selective intra-arterial calcium stimulation in the diagnosis of hyperinsulinaemic hypoglycaemia in childhood warrants further investigation. Key messages Calcium mediates insulin secretion at a cellular level In persistent hyperinsulinaemic hypoglycaemia of infancy (PHHI) there is a defect in control of intracellular calcium in islet cells High external calcium levels increase intracellular calcium in islet cells from patients with PHHI Intra-arterial calcium gluconate injection stimulates insulin secretion from the pancreas in PHHI

Angrites are a small group of ancient basaltic achondrites, notable for their unusual chemistry and extreme volatile depletion. No comprehensive study of indigenous light elements currently exists for the group. Measurement of the abundances and isotopic composition of carbon and nitrogen could provide information pertaining to the evolution of the angrite parent body. Bulk-sample stepped combustion analyses of five angrites and a glass separate from D'Orbigny were combined with earlier data and acid dissolution experiments of carbonates found in D'Orbigny to compile an inventory of indigenous carbon and nitrogen. Indigenous carbon combusted between 700 °C and 1200 °C, with abundances of 10–140 ppm and a mass-weighted δ 13 C of −25 to −20‰ with the exception of D'Orbigny (δ 13 C approximately −5‰). Nitrogen was released at 850–1200 oC, 1–20 ppm with a δ 15 N −3‰ to +4‰; again, D'Orbigny (δ 15 N approximately +20 to +25‰) was an exception. We interpret these components as largely indigenous and decoupled; the carbon in graphitic or amorphous form, while the nitrogen is present as a dissolved component in the silicates. No relationship with the textural sub-classification of angrites is apparent. We suggest that the angrite parent body contains a reservoir of reduced carbon and thus may have undergone a change in redox conditions, although the timing and mechanism for this remain unclear.