2,458 research outputs found
Spatial variability in shrub vegetation across dune forms in central Saudi Arabia
In desert dune environments, vegetation may be an indicator of dune stability and rates of sediment transport. As topography and underlying controls of vegetation vary over large spatial areas variations in dune form make scaling up of field research difficult. To mitigate this, and to identify spatial variations in vegetation distributions in a Saudi Arabian sand sea, spectral information from high resolution satellite images was classified to map polygons of shrub vegetation over 360 km2 of well-defined linear dunes, broken linear dunes and dome dune forms. When compared to topographic characteristics of the landscape extracted from a digital elevation model, vegetation densities were often highest on 10 to 20-degree slopes elevated above interdune salt deposits on dune flanks. Spatially this was confined to small areas, and density was not always related to dune form, more to the presence of groundwater which could also encourage vegetation on the tops of some dunes. Field observations identified shrubs of mainly Calligonum genus whose size is related to the amounts of salts, moving sediment and access to the water table that varies within and between dune forms. Shrub vegetation density is likened to surface roughness to better understand sediment movement in this environment
Phosphorus species in sequentially extracted soil organic matter fractions
The majority of organic P (Porg) in soil is considered to be part of soil organic matter (SOM) associations, but its chemical nature is largely âunresolvedâ. In this study, we investigated the Porg composition in different SOM fractions of a Gleysol soil using the Humeomics sequential chemical fractionation (SCF) procedure combined with nuclear magnetic resonance (NMR) spectroscopy.
In summary, SCF procedure with subsequent NaOH-EDTA extraction of the soil residue extracted a total of 1769 mg P/kgsoil compared to 1682 mg P/kgsoil of a single-step NaOH-EDTA extraction. Approximately 38 % of the extracted Porg was present in the form of the unresolved Porg pool, which was represented by one or two underlying broad signals in the phosphomonoester region of solution 31P NMR spectra. The SCF revealed that phosphomonoesters were recovered in each fraction: 47 % of the unresolved phosphomonoesters were associated with the SOM fraction released by breaking ester bonds (40 %) and ether bonds (7 %), whereas about 30 % of this unresolved Porg pool appeared in the SOM fraction closely associated with the soil mineral phase. Furthermore, the extractability of inositol phosphates (IP) was increased from 312 mg P/kgsoil to 534 mg P/kgsoil (factor 1.7) using the SCF procedure compared to a single-step NaOH-EDTA extraction. Previous studies have reported the presence of IP in molecular size fractions greater than 10 kDa. Our findings on the removal of IP with the fractionation of the SOM could explain the presence of IP in these large associations.
We demonstrate that major pools of Porg are closely associated with SOM structures, comprising a diverse array of chemical species and bonding types. These results forward our understanding of Porg stabilisation, P transformation, and P cycling in terrestrial ecosystems towards an association point of view
A systematic review on the effects of Echinacea supplementation on cytokine levels: Is there a role in COVID-19?
COVID-19 is the respiratory illness caused by the novel coronavirus, SARS-CoV-2. Cytokine storm appears to be a factor in COVID-19 mortality. Echinacea species have been used historically for immune modulation. A previous rapid review suggested that Echinacea supplementation may decrease the levels of pro-inflammatory cytokines involved in cytokine storm. The objective of the present systematic review was to identify all research that has assessed changes in levels of cytokines relevant to cytokine storm in response to administration of Echinacea supplementation. The following databases were searched: Medline (Ovid), AMED (Ovid), CINAHL (EBSCO), EMBASE (Ovid). Title and abstract screening, full text screening, and data extraction were completed in duplicate using a piloted extraction template. Risk of bias assessment was completed. Qualitative analysis was used to assess for trends in cytokine level changes. The search identified 279 unique publications. After full text screening, 105 studies met criteria for inclusion including 13 human studies, 24 animal studies, and 71 in vitro or ex vivo studies. The data suggest that Echinacea supplementation may be associated with a decrease in the pro-inflammatory cytokines IL-6, IL-8, and TNF, as well as an increase in the anti-inflammatory cytokine IL-10. The risk of bias in the included studies was generally high. While there is currently no substantive research on the therapeutic effects of Echinacea in the management of either cytokine storm or COVID-19, the present evidence related to the herb's impact on cytokine levels suggests that further research may be warranted in the form of a clinical trial involving patients with COVID-19
Metastatic seminoma with isolated gastric metastases:a case report
Gastric metastases are a rare occurrence in patients with malignancy. In case reports of these arising from germ cell tumours, the majority were non-seminomatous germ cell tumours and had evidence of retroperitoneal involvement. We present a unique case of a 67-year-old man with metastatic testicular pure seminoma. He presented with dyspepsia and investigation found isolated metastases to the gastric mucosa and sub-mucosa from a right testicular primary. No lymph node involvement was identified. The patient was managed with curative intent with total gastrectomy and inguinal orchidectomy. To date, there is no evidence of disease recurrence
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Fundamental laws govern all complex flow systems, including natural ecosystems, economic and financial systems. Natural ecosystems are practical examples of sustainability: enduring, vital, adaptive. The sustainability of any complex flow system can be measured with a single metric as emergent property of its structural diversity and interconnectivity; it requires a balance in emphasis between efficiency and resilience. The urgent message for economics from nature is that the monoculture of national currencies, justified on the basis of market efficiency, generates structural instability in our global financial system. Economic sustainability therefore requires differentiation in types of currencies, specifically through complementary currencies.ĐŃĐ” ŃĐ»ĐŸĐ¶ĐœŃĐ” ĐżĐŸĐŽĐČĐžĐ¶ĐœŃĐ” ŃĐžŃŃĐ”ĐŒŃ, ĐČ ŃĐŸĐŒ ŃĐžŃлД ĐżŃĐžŃĐŸĐŽĐœŃĐ” ŃĐșĐŸŃĐžŃŃĐ”ĐŒŃ ĐžĐ»Đž ŃĐșĐŸĐœĐŸĐŒĐžŃĐ”ŃĐșОД Đž ŃĐžĐœĐ°ĐœŃĐŸĐČŃĐ” ŃĐžŃŃĐ”ĐŒŃ, ŃĐżŃĐ°ĐČĐ»ŃŃŃŃŃ ŃŃĐœĐŽĐ°ĐŒĐ”ĐœŃĐ°Đ»ŃĐœŃĐŒĐž Đ·Đ°ĐșĐŸĐœĐ°ĐŒĐž. ĐŃĐžŃĐŸĐŽĐœŃĐ” ŃĐșĐŸŃĐžŃŃĐ”ĐŒŃ â ŃŃĐŸ ĐżŃĐ°ĐșŃĐžŃĐ”ŃĐșОД ĐżŃĐžĐŒĐ”ŃŃ ĐŽĐ»ĐžŃДлŃĐœĐŸĐč ŃŃŃĐŸĐčŃĐžĐČĐŸŃŃĐž (sustainability): ĐŸĐœĐž ĐČŃĐŽĐ”ŃжОĐČĐ°ŃŃ ĐżŃĐŸĐČĐ”ŃĐșŃ ĐČŃĐ”ĐŒĐ”ĐœĐ”ĐŒ, ĐżŃĐžŃĐżĐŸŃаблОĐČĐ°ŃŃŃŃ Đș ĐžĐ·ĐŒĐ”ĐœĐ”ĐœĐžŃĐŒ, ĐČŃжОĐČĐ°ŃŃ. ĐлОŃДлŃĐœŃŃ ŃŃŃĐŸĐčŃĐžĐČĐŸŃŃŃ Đ»ŃĐ±ĐŸĐč ŃĐ»ĐŸĐ¶ĐœĐŸĐč ĐżĐŸĐŽĐČĐžĐ¶ĐœĐŸĐč ŃĐžŃŃĐ”ĐŒŃ ĐŒĐŸĐ¶ĐœĐŸ ĐžĐ·ĐŒĐ”ŃĐžŃŃ ĐșĐŸĐ»ĐžŃĐ”ŃŃĐČĐ”ĐœĐœĐŸ ĐșĐ°Đș ŃŃĐœĐșŃĐžŃ Đ”Đ” ŃŃŃŃĐșŃŃŃĐœĐŸĐč ĐŽĐžĐČĐ”ŃŃĐžŃĐžĐșĐ°ŃОО Đž ĐČĐœŃŃŃĐ”ĐœĐœĐ”Đč ĐČĐ·Đ°ĐžĐŒĐŸŃĐČŃĐ·Đ°ĐœĐœĐŸŃŃĐž; Đ”Đč ŃŃДбŃĐ”ŃŃŃ ŃĐŸĐ±Đ»ŃĐŽĐ”ĐœĐžĐ” ŃĐ°ĐČĐœĐŸĐČĐ”ŃĐžŃ ĐŒĐ”Đ¶ĐŽŃ ŃŃŃĐ”ĐșŃĐžĐČĐœĐŸŃŃŃŃ Đž гОбĐșĐŸŃŃŃŃ. ĐŃĐžŃĐŸĐŽĐ° ĐżĐŸŃŃĐ»Đ°Đ”Ń ŃĐșĐŸĐœĐŸĐŒĐžĐșĐ” ŃŃĐŸŃĐœĐŸĐ” ŃĐŸĐŸĐ±ŃĐ”ĐœĐžĐ” ĐŸ ŃĐŸĐŒ, ŃŃĐŸ ĐŒĐŸĐœĐŸĐșŃĐ»ŃŃŃŃĐ° ĐœĐ°ŃĐžĐŸĐœĐ°Đ»ŃĐœŃŃ
ĐČĐ°Đ»ŃŃ, ĐŸĐżŃĐ°ĐČĐŽĐ°ĐœĐœĐ°Ń Ń ŃĐŸŃĐșĐž Đ·ŃĐ”ĐœĐžŃ ŃŃĐœĐŸŃĐœĐŸĐč ŃŃŃĐ”ĐșŃĐžĐČĐœĐŸŃŃĐž, ĐżĐŸŃĐŸĐ¶ĐŽĐ°Đ”Ń ŃŃŃŃĐșŃŃŃĐœŃŃ ĐœĐ”ŃŃŃĐŸĐčŃĐžĐČĐŸŃŃŃ ĐœĐ°ŃĐ”Đč ĐłĐ»ĐŸĐ±Đ°Đ»ŃĐœĐŸĐč ŃĐžĐœĐ°ĐœŃĐŸĐČĐŸĐč ŃĐžŃŃĐ”ĐŒŃ, Đž ĐżĐŸŃŃĐŸĐŒŃ ĐŸĐ±Đ”ŃпДŃĐ”ĐœĐžĐ” ЎлОŃДлŃĐœĐŸĐč ŃĐșĐŸĐœĐŸĐŒĐžŃĐ”ŃĐșĐŸĐč ŃŃŃĐŸĐčŃĐžĐČĐŸŃŃĐž ŃŃДбŃĐ”Ń ĐŽĐžĐČĐ”ŃŃĐžŃĐžĐșĐ°ŃОО ĐČĐ°Đ»ŃŃ, ĐČ ŃĐ°ŃŃĐœĐŸŃŃĐž, ŃĐ”ŃДз ĐČĐČĐ”ĐŽĐ”ĐœĐžĐ” ĐŽĐŸĐżĐŸĐ»ĐœĐžŃДлŃĐœŃŃ
ДД ŃĐžĐżĐŸĐČ
The reaction of an α-aza-amino acid derivative with chymotrypsin and its use as a ligand for covalent affinity purification
A T Cell-inducing influenza vaccine for the elderly: safety and immunogenicity of MVA-NP+M1 in adults aged over 50 years
Current influenza vaccines have reduced immunogenicity and are of uncertain efficacy in older adults. We assessed the safety and immunogenicity of MVA-NP+M1, a viral-vectored influenza vaccine designed to boost memory T cell responses, in a group of older adults.Thirty volunteers (aged 50-85) received a single intramuscular injection of MVA-NP+M1 at a dose of 1·5Ă10(8) plaque forming units (pfu). Safety and immunogenicity were assessed over a period of one year. The frequency of T cells specific for nucleoprotein (NP) and matrix protein 1 (M1) was determined by interferon-gamma (IFN-Îł) ELISpot, and their phenotypic and functional properties were characterized by polychromatic flow cytometry. In a subset of M1-specific CD8(+) T cells, T cell receptor (TCR) gene expression was evaluated using an unbiased molecular approach.Vaccination with MVA-NP+M1 was well tolerated. ELISpot responses were boosted significantly above baseline following vaccination. Increases were detected in both CD4(+) and CD8(+) T cell subsets. Clonality studies indicated that MVA-NP+M1 expanded pre-existing memory CD8(+) T cells, which displayed a predominant CD27(+)CD45RO(+)CD57(-)CCR7(-) phenotype both before and after vaccination.MVA-NP+M1 is safe and immunogenic in older adults. Unlike seasonal influenza vaccination, the immune responses generated by MVA-NP+M1 are similar between younger and older individuals. A T cell-inducing vaccine such as MVA-NP+M1 may therefore provide a way to circumvent the immunosenescence that impairs routine influenza vaccination.ClinicalTrials.gov NCT00942071
Erratum to: Localization of Fatty Acyl and Double Bond Positions in Phosphatidylcholines Using a Dual Stage CID Fragmentation Coupled with Ion Mobility Mass Spectrometry.
A high content molecular fragmentation for the analysis of phosphatidylcholines (PC) was achieved utilizing a two-stage [trap (first generation fragmentation) and transfer (second generation fragmentation)] collision-induced dissociation (CID) in combination with travelling-wave ion mobility spectrometry (TWIMS). The novel aspects of this work reside in the fact that a TWIMS arrangement was used to obtain a high level structural information including location of fatty acyl substituents and double bonds for PCs in plasma, and the presence of alkali metal adduct ions such as [Mâ+âLi](+) was not required to obtain double bond positions. Elemental compositions for fragment ions were confirmed by accurate mass measurements. A very specific first generation fragment ion m/z 577 (M-phosphoryl choline) from the PC [16:0/18:1 (9Z)] was produced, which by further CID generated acylium ions containing either the fatty acyl 16:0 (C(15)H(31)CO(+), m/z 239) or 18:1 (9Z) (C(17)H(33)CO(+), m/z 265) substituent. Subsequent water loss from these acylium ions was key in producing hydrocarbon fragment ions mainly from the α-proximal position of the carbonyl group such as the hydrocarbon ion m/z 67 (+H(2)C-HCâ=âCH-CHâ=âCH(2)). Formation of these ions was of important significance for determining double bonds in the fatty acyl chains. In addition to this, and with the aid of (13)C labeled lyso-phosphatidylcholine (LPC) 18:1 (9Z) in the Ï-position (methyl) TAP fragmentation produced the ion at m/z 57. And was proven to be derived from the α-proximal (carboxylate) or distant Ï-position (methyl) in the LPC. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13361-011-0172-2) contains supplementary material, which is available to authorized users
Herschel/HIFI deepens the circumstellar NH3 enigma
Circumstellar envelopes (CSEs) of a variety of evolved stars have been found
to contain ammonia (NH3) in amounts that exceed predictions from conventional
chemical models by many orders of magnitude. The observations reported here
were performed in order to better constrain the NH3 abundance in the CSEs of
four, quite diverse, oxygen-rich stars using the NH3 ortho J_K = 1_0 - 0_0
ground-state line. We used the Heterodyne Instrument for the Far Infrared
aboard Herschel to observe the NH3 J_K = 1_0 - 0_0 transition near 572.5 GHz,
simultaneously with the ortho-H2O J_Ka,Kc = 1_1,0 -1_0,1 transition, toward VY
CMa, OH 26.5+0.6, IRC+10420, and IK Tau. We conducted non-LTE radiative
transfer modeling with the goal to derive the NH3 abundance in these objects'
CSEs. For the latter two stars, Very Large Array imaging of NH3
radio-wavelength inversion lines were used to provide further constraints,
particularly on the spatial extent of the NH3-emitting regions. Results. We
find remarkably strong NH3 emission in all of our objects with the NH3 line
intensities rivaling those obtained for the ground state H2O line. The NH3
abundances relative to H2 are very high and range from 2 x 10-7 to 3 x 10-6 for
the objects we have studied. Our observations confirm and even deepen the
circumstellar NH3 enigma. While our radiative transfer modeling does not yield
satisfactory fits to the observed line profiles, it leads to abundance
estimates that confirm the very high values found in earlier studies. New ways
to tackle this mystery will include further Herschel observations of more NH3
lines and imaging with the Expanded Very Large Array.Comment: 4+2 page
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