bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of an extreme desert dust event on the spectral ultraviolet irradiance at El Arenosillo (Spain)
Authors: Antón M. , Sorribas M. , Bennouna Y. , Vilaplana J. M. , Cachorro V. E. , Gröbner J. , Alados‐Arboledas L. 
Published: December 2011

This paper analyzes the effects of an extreme Saharan dust event detected on 6 September 2007 on spectral UV irradiance recorded at El Arenosillo, South Spain. The intensity of the extreme event was detected using the aerosol optical depth (AOD) and Angström exponent series obtained by a Cimel Sun photometer operated at the study site in the framework of the Aerosol Robotic Network (AERONET). This Saharan dust event is characterized by its strong intensity, with a mean daily AOD value at 440 nm of 1.35 ± 0.40 (1.76 ± 0.03 around 13:00 UT). Additionally, a moderate decrease (∼15 Dobson units (1 DU = 2.69 × 1016 molecules cm−2)) in the total ozone column was recorded with a Brewer spectrophotometer during this episode. The spectral UV irradiance was measured from the transportable Quality Assurance of Spectral Ultraviolet Measurements in Europe (QASUME) through the development of a transportable unit reference spectroradiometer. The relative decrease of the UV irradiance at 320 nm on 6 September is about 50% (40%) with respect to days with low (moderate) aerosol loads. This attenuation slightly decreases with increasing wavelength above 315 nm. The relative differences between QASUME measurements and the spectral UV irradiance derived from the Ozone Monitoring Instrument (OMI) were calculated for the desert dust episode. This satellite instrument strongly overestimates the ground‐based UV data recorded on 6 September, with differences between 138% at 305 nm and 72% at 380 nm. Finally, the aerosol forcing efficiency (AFE) is evaluated for UV‐B (290–315 nm), UV‐A (315–400 nm), and erythemal UV (290–400 nm, weighted by the CIE spectrum), showing a notable decrease (in absolute value) with increasing solar zenith angles (SZAs). For instance, the AFE values for the harmful UV‐B irradiance change from −0.41 W/m2 per unit of AOD at 440 nm for a SZA of 30° to −0.21 W/m2 per unit of AOD for a SZA of 50°.
Ultrahydrous stishovite from high-pressure hydrothermal treatment of SiO2
Authors: Spektor Kristina , Nylen Johanna , Stoyanov Emil , Navrotsky Alexandra , Hervig Richard L. , Leinenweber Kurt , Holland Gregory P. , Häussermann Ulrich 
Published: December 2011

Stishovite (SiO2with the rutile structure and octahedrally coordinated silicon) is an important high-pressure mineral. It has previously been considered to be essentially anhydrous. In this study, hydrothermal treatment of silica glass and coesite at 350–550 °C near 10 GPa produces stishovite with significant amounts of H2O in its structure. A combination of methodologies (X-ray diffraction, thermal analysis, oxide melt solution calorimetry, secondary ion mass spectrometry, infrared and nuclear magnetic resonance spectroscopy) indicate the presence of 1.3 ± 0.2 wt % H2O and NMR suggests that the primary mechanism for the H2O uptake is a direct hydrogarnet-like substitution of 4H+for Si4+, with the protons clustered as hydroxyls around a silicon vacancy. This substitution is accompanied by a substantial volume decrease for the system (SiO2 + H2O), although the stishovite expands slightly, and it is only slightly unfavorable in energy. Stishovite could thus be a host for H2O at convergent plate boundaries, and in other relatively cool high-pressure environments.
A Single Ancient Origin for Prototypical Serine/Arginine-Rich Splicing Factors
Authors: Califice Sophie , Baurain Denis , Hanikenne Marc , Motte Patrick 
Published: December 2011

Abstract
Eukaryotic precursor mRNA splicing is a process involving a very complex RNA-protein edifice. Serine/arginine-rich (SR) proteins play essential roles in precursor mRNA constitutive and alternative splicing and have been suggested to be crucial in plant-specific forms of developmental regulation and environmental adaptation. Despite their functional importance, little is known about their origin and evolutionary history. SR splicing factors have a modular organization featuring at least one RNA recognition motif (RRM) domain and a carboxyl-terminal region enriched in serine/arginine dipeptides. To investigate the evolution of SR proteins, we infer phylogenies for more than 12,000 RRM domains representing more than 200 broadly sampled organisms. Our analyses reveal that the RRM domain is not restricted to eukaryotes and that all prototypical SR proteins share a single ancient origin, including the plant-specific SR45 protein. Based on these findings, we propose a scenario for their diversification into four natural families, each corresponding to a main SR architecture, and a dozen subfamilies, of which we profile both sequence conservation and composition. Finally, using operational criteria for computational discovery and classification, we catalog SR proteins in 20 model organisms, with a focus on green algae and land plants. Altogether, our study confirms the homogeneity and antiquity of SR splicing factors while establishing robust phylogenetic relationships between animal and plant proteins, which should enable functional analyses of lesser characterized SR family members, especially in green plants.
Expression profile of heat shock proteins in acute myeloid leukaemia patients reveals a distinct signature strongly associated with FLT3 mutation status – consequences and potentials for pharmacological intervention
Authors: Reikvam Håkon , Hatfield Kimberley J. , Ersvær Elisabeth , Hovland Randi , Skavland Jørn , Gjertsen Bjørn T. , Petersen Kjell , Bruserud Øystein 
Published: December 2011

SummaryHeat shock proteins (HSPs) are molecular chaperones that assist proteins in their folding to native structures. HSPs are regarded as possible therapeutic targets in acute myeloid leukaemia (AML). We used bioinformatical approaches to characterize the HSP profile in AML cells from 75 consecutive patients, in addition to the effect of the HSP90 inhibitor 17‐DMAG. Patients harbouring a FLT3‐internal tandem duplication (FLT3‐ITD) were extensively overrepresented in the cluster with high HSP levels, indicating a strong dependence of HSPs in stabilizing FLT3‐ITD encoded oncoproteins. FLT3 ligation further increased the levels of HSP90 and its co‐chaperone HSP70. HSP90 inhibition had a stronger pro‐apoptotic effect for AML cells with FLT3‐ITD than for cells with wild‐type FLT3, whereas the anti‐proliferative effect of HSP90 inhibition was similar for the two patient subsets. HSP90 inhibition altered the constitutive cytokine release profile in an anti‐angiogenic direction independent of FLT3 mutational status: (i) pro‐angiogenic CXCL8, MMP‐2 and MMP‐9 showed a stronger decrease than anti‐angiogenic CXCL9–11, (ii) the Tie‐2 agonist Ang‐1 showed a stronger decrease than the potentially antagonistic Ang‐2, and (iii) VEGF and HGF levels were decreased. Finally, HSP90 inhibition counteracted the leukaemia‐stimulating effect of endothelial cells. Our studies demonstrate that HSP90 inhibition mediates anti‐leukaemic effects through both direct and indirect activity.
Low serum high‐density lipoprotein cholesterol in childhood is associated with adolescent asthma
Authors: Yiallouros P. K. , Savva S. C. , Kolokotroni O. , Behbod B. , Zeniou M. , Economou M. , Chadjigeorgiou C. , Kourides Y. A. , Tornaritis M. J. , Lamnisos D. , Middleton N. , Milton D. K. 
Published: December 2011

SummaryBackgroundWhilst emerging evidence from animal and cell experiments has shown high‐density lipoprotein cholesterol to have anti‐inflammatory effects consistent with a protective role in asthma, human studies investigating the relationship of high‐density lipoprotein cholesterol with asthma have produced conflicting results.ObjectiveTo examine the association between serum lipids among Cypriot children aged 11–12 years and prevalence of asthma at age 15–17 years.MethodsIn 3982 children, we assessed serum lipids, body mass index and maximal oxygen consumption at baseline (2001–2003) and explored associations with respiratory health at follow‐up (2007) using multiple logistic regression models.ResultsLower levels of high‐density lipoprotein cholesterol at age 11–12 years were found in subjects who reported ever asthma (58.2 vs. 60.0 mg/dL, P = 0.005) and active asthma (57.5 vs. 59.9 mg/dL, P = 0.010) in adolescence, in comparison with their respective reference groups. Total cholesterol, low‐density lipoprotein and triglycerides had no association with any of the asthma outcomes. In contrast, with estimated odds ratios of 1.89 (95% CI 1.19–3.00) and 1.89 (95% CI 1.02–3.53), ever asthma and active asthma respectively appeared particularly pronounced among those who at baseline had high‐density lipoprotein cholesterol <40 mg/dL, even after adjusting for potential confounders including body mass index and maximal oxygen consumption.Conclusions & Clinical RelevanceLow‐serum high‐density lipoprotein cholesterol in childhood is associated with an increased risk for asthma in adolescence, suggesting a potential role of this lipoprotein in the pathogenesis of paediatric asthma.
Probiotic effects on T‐cell maturation in infants during weaning
Authors: West C. E. , Hernell O. , Andersson Y. , Sjöstedt M. , Hammarström M.‐L. 
Published: December 2011

SummaryBackgroundWe previously reported that feeding the probiotic Lactobacillus paracasei ssp. paracasei F19 (LF19) during weaning reduced the cumulative incidence of eczema.ObjectiveTo investigate the impact of feeding LF19 on T‐cell maturation.MethodsOne hundred and seventy‐nine healthy, term infants with no prior allergic manifestations were randomized to daily intake of cereals with (n = 89) or without (n = 90) the addition of LF19 108 colony forming units per serving from 4 to 13 months of age. Venous blood was drawn at 5.5 and 13 months of age. We used the cytokine response to polyclonal T‐cell stimulation by anti‐CD3 plus anti‐CD28 monoclonal antibodies, and in vitro stimulation with the vaccine tetanus toxoid (TT) as measures of global adaptive immunity and capacity to raise a specific T‐cell response, respectively. Expression levels of IL‐2, IFN‐γ, IL‐4, IL‐17A and IL‐10 messenger RNAs (mRNAs) were used as proxies for general T‐cell stimulation and naive Th0 cells, Th1‐, Th2‐, Th17‐ and T regulatory lineages.ResultsThere was no difference between the two groups at 5.5 months of age. At 13 months, the polyclonal IL‐2 response was higher in the placebo group (P < 0.05), whereas the IFN‐γ/IL‐2 (P < 0.01) and IL‐17A/IL‐2 (P < 0.05) ratios after polyclonal stimulation were higher in the probiotic group, as was the TT‐specific IL17‐A response (P < 0.001). In both groups, the IFN‐γ and IL‐4 responses increased from 5.5 to 13 months upon both polyclonal and specific stimulation (P < 0.01), whereas the IL‐10 response remained low (P > 0.05).Conclusion and Clinical RelevanceOur findings suggest modest effects by probiotics on T‐cell maturation following 9 months of probiotic intake. Future studies should address if specific probiotics may drive immune development with possible preventive effects on the development of allergic disease.
The Goldilocks effect: intermittent streams sustain more plant species than those with perennial or ephemeral flow
Authors: KATZ GABRIELLE L. , DENSLOW MICHAEL W. , STROMBERG JULIET C. 
Published: December 2011

Summary1. Drylands worldwide are typified by extreme variability in hydrologic processes, which structures riparian communities at various temporal and spatial scales. One key question is how underlying differences in hydrology over the length of interrupted perennial rivers influence spatial and temporal patterns in species richness and species composition.2. We examined effects of differences in dry season hydrology on species richness, composition and cover of herbaceous plant communities in the streamside zone (the zone influenced directly by low flows in the channel). Data were collected at ephemeral, intermittent and perennial flow reaches on three rivers of the desert Southwest (Arizona, U.S.A.): Lower Cienega Creek, Hassayampa River and Lower San Pedro River.3. Patterns of species richness varied with temporal scale of analysis, that is between single‐year and multi‐year time frames. At the annual timescale, quadrat species richness (m−2) and herbaceous cover were higher at sites with perennial flow than at either intermittent or ephemeral sites. In contrast to this single‐year pattern, the highest long‐term richness occurred at intermittent sites.4. Quadrat species richness, total species richness at a site (per 18 1‐m2 plots) and cover were more variable year to year at non‐perennial sites than at perennial flow sites. On two of the three rivers, ephemeral sites had the highest inter‐annual compositional variance, while the perennial sites had the lowest.5. Compositional differences between the hydrologic site types were dominated by species turnover, not nestedness. The perennial sites had more wetland and perennial species than the other two site types. The intermittent sites had more annual species than did the other two types.6. High long‐term species richness and distinct species composition of intermittent sites are probably sustained by pronounced temporal variability in environmental conditions (i.e. frequent and persistent flow events, and dry periods). Plants at these sites take advantage of greater moisture than those at ephemeral sites and also experience less competition from resident species than those at perennial sites.7. Conservation of desert riparian diversity depends upon the protection of consistently wet conditions at perennial flow sites, as well as the maintenance of the processes that cause fluctuations in environmental conditions at non‐perennial sites.
Temperature affects the limitation of Daphnia magna by eicosapentaenoic acid, and the fatty acid composition of body tissue and eggs
Authors: SPERFELD ERIK , WACKER ALEXANDER 
Published: December 2011

Summary1. Poikilothermic animals incorporate more polyunsaturated fatty acids (PUFAs) into their cellular membranes as temperature declines, suggesting an increased sensitivity to PUFA limitation in cool conditions. To test this we raised Daphnia magna at different temperatures and investigated the effect of varying dietary PUFA on life history parameters (i.e. growth, reproduction) and the PUFA composition of body tissue and eggs.2. Upon a PUFA‐rich diet (Cryptomonas sp.) females showed higher concentrations of several ω3 PUFAs in their body tissue at 15 °C than at 20 °C and 25 °C, indicating a greater structural requirement for ω3 PUFAs at low temperature. Their eggs had an equal but higher concentration of ω3 PUFAs than their body tissue.3. In a life history experiment at 15 and 20 °C we supplemented a diet of a PUFA‐free cyanobacterium with the ω3 PUFA eicosapentaenoic acid (EPA). The growth of D. magna was more strongly EPA limited at low temperature. A greater requirement for structural EPA at 15 °C was indicated by a steeper increase in somatic EPA content with dietary EPA compared to 20 °C.4. At 20 °C the development of eggs to successful hatching was high when EPA was supplied to the mothers. At 15 °C the hatching success was generally poor, despite of a higher maternal provision of EPA to eggs, compared to that at 20 °C, suggesting that EPA alone was insufficient for proper neonatal development at the low temperature. The growth of offspring from mothers raised at 20 °C without EPA supplementation was very low, indicating that the negative effects of EPA deficiency can be carried on to the next generation.5. The fatty acid composition of Daphnia sp. in published field studies shows increasing proportions of saturated fatty acids with increasing environmental temperature, whereas ω3 PUFAs and EPA show no clear pattern, suggesting that variations in dietary PUFA may mask temperature‐dependent adjustments in ω3 PUFA concentrations of cladocerans in nature.
Associations between congenital cryptorchidism in newborn boys and levels of dioxins and PCBs in placenta
Authors: Virtanen H. E. , Koskenniemi J. J. , Sundqvist E. , Main K. M. , Kiviranta H. , Tuomisto J. T. , Tuomisto J. , Viluksela M. , Vartiainen T. , Skakkebaek N. E. , Toppari J. 
Published: December 2011

SummaryIn animal studies, exposure to dioxins has been associated with disrupted development of the male reproductive system, including testicular maldescent. Some polychlorinated biphenyls (PCBs) have also dioxin‐like effects. In addition, one previous case–control study has reported an association between congenital cryptorchidism and colostrum PCB levels. We performed a case–control study to evaluate whether congenital cryptorchidism in boys was associated with increased levels of dioxins or PCBs in placenta reflecting foetal exposure. In addition, associations between placenta levels of these chemicals and reproductive hormone levels in boys at 3 months were studied. Placentas were collected in a Danish–Finnish joint prospective cohort study on cryptorchidism (1997–2001). The boys were examined for cryptorchidism at birth and at 3 months. Altogether, 280 placentas [112 Finnish (56 cases, 56 controls) and 168 Danish (39 cases, 129 controls)] were analysed for 17 toxic polychlorinated dibenzo‐p‐dioxins and dibenzofurans (PCDD/Fs) and 37 PCBs (including 12 dioxin‐like PCBs). Infant serum samples taken at 3 months were analysed for reproductive hormones. No significant differences between cases and controls were observed in either country in dioxin WHO‐TEq levels (median 9.78 vs. 8.47 pg/g fat, respectively, in Finland, and 11.75 vs. 10.88 pg/g fat in Denmark) or PCB WHO‐TEq levels (median 2.12 vs. 2.15 pg/g fat in Finland, 2.34 vs. 2.10 pg/g fat in Denmark) or total‐TEq levels (median 11.66 vs. 10.58 pg/g fat in Finland, 13.94 vs. 13.00 pg/g fat in Denmark). Placenta WHO‐TEq levels of dioxins were not associated with infant reproductive hormone levels at 3 months. In Finland, PCB WHO‐TEq levels in placenta associated positively with infant LH levels. WHO‐TEq levels of dioxins and PCBs and total‐TEq levels were higher in Danish than Finnish samples. In conclusion, no association between placenta levels of dioxins or PCBs and congenital cryptorchidism was found. Significant country differences in chemical levels were observed.
Foetal and post‐natal exposure of sheep to sewage sludge chemicals disrupts sperm production in adulthood in a subset of animals
Authors: Bellingham M. , McKinnell C. , Fowler P. A. , Amezaga M. R. , Zhang Z. , Rhind S. M. , Cotinot C. , Mandon‐Pepin B. , Evans N. P. , Sharpe R. M. 
Published: December 2011

SummaryExposure to ubiquitous, environmental chemicals (ECs) has been hypothesized as a cause for declining male reproductive health. Understanding the long‐term effects of EC exposure on reproductive health in humans requires animal models and exposure to ‘real life’, environmentally relevant, mixtures during development, a life stage of particular sensitivity to ECs. The aim of this study was to evaluate the effects of in utero and post‐natal exposure to environmentally relevant levels of ECs, via sewage sludge application to pasture, on the adult male sheep testis. Hormones, liver concentrations of candidate ECs and Sertoli and germ cell numbers in testes of adult rams that were exposed to ECs in sewage sludge in utero, and until weaning via maternal exposure, and post‐weaning via grazing pastures fertilized with sewage sludge, were quantified. Evaluated as a single group, exposure to sludge ECs was without significant effect on most parameters. However, a more detailed study revealed that 5 of 12 sludge‐exposed rams exhibited major spermatogenic abnormalities. These consisted of major reductions in germ cell numbers per testis or per Sertoli cell and more Sertoli cell‐only tubules, when compared with controls, which did not show any such changes. The sludge‐related spermatogenic changes in the five affected animals were significantly different from controls (p < 0.001); Sertoli cell number was unaffected. Hormone profiles and liver candidate EC concentrations were not measurably affected by exposure. We conclude that developmental exposure of male sheep to real‐world mixtures of ECs can result in major reduction in germ cell numbers, indicative of impaired sperm production, in a proportion of exposed males. The individual‐specific effects are presumed to reflect EC effects on a heterogeneous population in which some individuals may be more susceptible to adverse EC effects. Such effects of EC exposure in humans could have adverse consequences for sperm counts and fertility in some exposed males.
Invasions: the trail behind, the path ahead, and a test of a disturbing idea
Authors: Moles Angela T. , Flores‐Moreno Habacuc , Bonser Stephen P. , Warton David I. , Helm Aveliina , Warman Laura , Eldridge David J. , Jurado Enrique , Hemmings Frank A. , Reich Peter B. , Cavender‐Bares Jeannine , Seabloom Eric W. , Mayfield Margaret M. , Sheil Douglas , Djietror Jonathan C. , Peri Pablo L. , Enrico Lucas , Cabido Marcelo R. , Setterfield Samantha A. , Lehmann Caroline E. R. , Thomson Fiona J. 
Published: December 2011

Summary1. We provide a brief overview of progress in our understanding of introduced plant species.2. Three main conclusions emerge from our review: (i) Many lines of research, including the search for traits that make species good invaders, or that make ecosystems susceptible to invasion, are yielding idiosyncratic results. To move forward, we advocate a more synthetic approach that incorporates a range of different types of information about the introduced species and the communities and habitats they are invading. (ii) Given the growing evidence for the adaptive capacity of both introduced species and recipient communities, we need to consider the implications of the long‐term presence of introduced species in our ecosystems. (iii) Several foundational ideas in invasion biology have become widely accepted without appropriate testing, or despite equivocal evidence from empirical tests. One such idea is the suggestion that disturbance facilitates invasion.3. We use data from 200 sites around the world to provide a broad test of the hypothesis that invasions are better predicted by a change in disturbance regime than by disturbance per se. Neither disturbance nor change in disturbance regime explained more than 7% of the variation in the % of cover or species richness contributed by introduced species. However, change in disturbance regime was a significantly better predictor than was disturbance per se, explaining approximately twice as much variation as did disturbance.4. Synthesis. Disturbance is a weak predictor of invasion. To increase predictive power, we need to consider multiple variables (both intrinsic and extrinsic to the site) simultaneously. Variables that describe the changes sites have undergone may be particularly informative.