Vanadium Uptake by Alfalfa Grown in V–Cd-Contaminated Soil by Pot Experiment

In order to characterize uptake of vanadium in alfalfa grown in vanadium–cadmium (Cd)-contaminated soil, 104 soil samples and 94 plant samples were collected from pot experiment. The results showed alfalfa had strong metal adaptability (up to 400 mg kg⁻¹) and high accumulation (up to 3,440.14 mg kg⁻¹) of vanadium. Root had higher contents and better absorption to vanadium than overground part. Moreover, both root and overground part had direct correlation with vanadium in soil, especially with the sum of first three fractions and reducible fraction. With the increasing of vanadium, higher concentration of Cd may inhibit the absorption of vanadium in alfalfa.     

Conditional outcomes in ant–plant–herbivore interactions influenced by sequential flowering

Mechanisms that affect a host plant’s ability to face herbivory are subjects of ongoing interest. Plant reproductive phenology plays a key role in the dynamics of communities in many ways. In ant–plant–herbivore interactions, host-plant phenology affects traits of its herbivores which in turn determine what traits ants must have to benefit the host-plant. Diversity of plant phenological traits could influence the ecological diversity of coevolved ant–plant mutualisms.     

Was the serine protease cathepsin G discovered by S. G. Hedin in 1903 in bovine spleen?

In the beginning of the 20th century, enzymes with proteolytic activity were classified as peptidases, Erepsin, and proteases. Among these, pepsin, trypsin, and autolytic enzymes were of the protease class. Spleen-derived proteases were poorly characterized until Sven Gustaf Hedin performed several digestion experiments with bovine spleen. He incubated minced bovine spleen under acidic or neutral conditions and characterized two active proteases; the results were published in 1903. The first protease was named α-protease and was active under neutral conditions. The second was named β-protease and was active under acidic conditions. We replicated Hedin's experiments according to his methods and found, by using activity-based probes to visualize proteases, that the historical α-protease is the present-day serine protease cathepsin G (CatG), which is known to be important in several immune processes, including antigen processing, chemotaxis, and activation of surface receptors. The β-protease, however, comprised different proteases including CatX, B, S, and D. We suggest that Hedin described CatG activity in bovine spleen over 100 years ago.     

Anthropometric measurements by ethnicity in Colombia, 1965–1990

We analyzed the evolution of height in Colombia of cohorts born in the period 1965–1990 by ethnic groups. We found that Afro-Colombian men and women were the tallest: 6 cm taller than indigenous people and 2 cm taller than the rest of the population. We also found that the height gap between Afro-Colombians and others decreased during the period under study by 0.7 cm for both men and women. While improvements were noticeable among the Afro-Colombians and those who chose not to be classified by ethnicity, in the case of the indigenous population only female cohorts registered an average-height increase of 1.5 cm. Moreover, we found that indigenous Colombians were more likely than other ethnic groups to experience an increase in biological well-being as a consequence of an improvement in their socio-economic status, thereby reducing the average-stature gap between them and the rest of the population by 2.1 and 3.6 cm for men and women, respectively.     

A search for O-polypeptidyl-ribonucleic acids in rabbit-reticulocyte ribosomes by electrophoresis in phenol–acetic acid–water systems

1. When solutions of `soluble' or transfer RNA (s-RNA) and of cytochrome c in phenol–acetic acid–water were mixed, intractable coacervates were formed. The addition to the solutions of various strong electrolytes prevented coacervation and allowed electrophoretic separation on filter paper. Protein migrates cationically, leaving RNA at or near the origin. The separation is aided by adsorption of RNA to the paper. Special arrangements were necessary to prevent contamination of the paper by ultraviolet-absorbing electrode-reaction products. 2. Binding of alkali-metal cations to RNA and some other associations were observed in such solvent systems. Possible effects of ionic association on mobilities are discussed. 3. Rabbit-reticulocyte ribosomes were subjected to electrophoresis as above, after their nascent-protein moiety had been labelled with [¹⁴C]valine in the intact cell. Most of the radioactivity migrated with the ribosomal protein; such protein as remained near the origin with the RNA had valine of lower specific radioactivity. 4. Molecular-sieve chromatography in phenol–acetic acid–water indicated that the nascent-protein moiety was not of markedly lower molecular weight than the average for the ribosomal proteins. 5. These results are very tentatively taken to mean that the nascent-protein moiety of ribosomes so prepared is not O-polypeptidyl-s-RNA. It is postulated that, in the course of adding each amino acid residue, the growing polypeptide chain is transferred from ester linkage with s-RNA to linkage with ribosomal protein through its carboxyl group, perhaps by ester linkage to an alcoholic group. The two types of intermediate, O-polypeptidyl-s-RNA and polypeptidyl-protein, would be found in different proportions, depending on the isolation procedure used. Some implications and possible tests of this hypothesis are discussed.     

Pivotal Role of Extended Linker 2 in the Activation of Gα by G Protein-coupled Receptor

G protein-coupled receptors (GPCRs) relay extracellular signals mainly to heterotrimeric G-proteins (Gαβγ) and they are the most successful drug targets. The mechanisms of G-protein activation by GPCRs are not well understood. Previous studies have revealed a signal relay route from a GPCR via the C-terminal α5-helix of Gα to the guanine nucleotide-binding pocket. Recent structural and biophysical studies uncover a role for the opening or rotating of the α-helical domain of Gα during the activation of Gα by a GPCR. Here we show that β-adrenergic receptors activate eight Gα_s mutant proteins (from a screen of 66 Gα_s mutants) that are unable to bind Gβγ subunits in cells. Five of these eight mutants are in the αF/Linker 2/β2 hinge region (extended Linker 2) that connects the Ras-like GTPase domain and the α-helical domain of Gα_s. This extended Linker 2 is the target site of a natural product inhibitor of G_q. Our data show that the extended Linker 2 is critical for Gα activation by GPCRs. We propose that a GPCR via its intracellular loop 2 directly interacts with the β₂/β₃ loop of Gα to communicate to Linker 2, resulting in the opening and closing of the α-helical domain and the release of GDP during G-protein activation.     

Cylindrical Magnetosonic Solitary Waves by Modified Korteweg–de Vries–Burgers Equation in Electron–Positron–Ion Plasma

Plasma Physics Reports - Theoretical investigations are carried out for the cylindrical magnetosonic solitary waves in dissipative, hot electron–positron–ion plasma. By the reductive...     

Dynamic structure–function relationships in enzyme stabilization by ionic liquids

The stability of α-chymotrypsin and Candida antarctica lipase B (CALB) in two ionic liquids (i.e. 1-ethyl-3-methyl-imidazolium, bis[(trifluoromethyl)sulfonyl]imide [emim] [NTf₂], and butyl-trimethylamonium bis[(trifluoromethyl)sulfonyl]imide [btma] [NTf₂]) has been studied. Both enzymes were strongly stabilized by the ionic liquids, the respective half-life times increasing 96 and 1660 times, with respect to those obtained in classical organic solvents such as 1-propanol and hexane, respectively. The stabilization of both enzymes by ionic liquids may be related to the associated structural changes of proteins that they can be observed by both fluorescence and circular dichroism spectroscopic studies.     

Fish–duck interactions in boreal lakes in Finland as reflected by abundance correlations

We studied the hypothesis that fish play an important role in lake use by ducks (pairs and broods) in boreal lakes. The study was based on densities of different duck and fish species in 28 boreal lakes in southern Finland. We focused on the three most common duck species (mallard Anas platyrhynchos, green-winged teal A. crecca and common goldeneye Bucephala clangula) and on the three most common fish species (perch Perca fluviatilis, roach Rutilus rutilus and pike Esox lucius) in the region. We considered both competitive and predatory interactions between ducks and fish, the perch and roach being potential competitors with ducks and the pike a potential predator of ducks. We found a negative association between green-winged teal brood density and total fish density, the other duck species having only a weak association with total fish density. When the three fish species were considered separately, a negative association, suggesting food competition, was found between perch, green-winged teal and goldeneye, whereas the role of roach as a food competitor seemed to be of minor importance. We did not find any clear signs of predatory effects of pike on ducks. Our results suggest that food competition is a more important factor than pike predation in affecting lake use by ducks in oligotrophic boreal environments in southern Finland.     

Chromosome G—banding in plants by inducing with trypsin and urea

Clear G-bands were revealed by applying the TUG method on chromosomes of 5 species of higher plants(Lilium davidii,Viciafaba,Hordeum vulgare,Ginkgo biloba and Triticum monococcum).Some details of the TUG method which consisted of treating chromosomes with both trypsin and urea were also studied.The mechanisms that might account for the presence of G-bands in plants were discussed.     

Marker Analysis of Quantitative Traits in Maize by ISSR–PCR

The segregating maize population (GK26 × Mo17)F₂ has been used for identification of ISSR markers able to reveal a significant difference between alleles by a quantitative index. Confidence ranges have been determined for variation in 17 quantitative traits. Variations in the traits under study correlate with the inheritance of 16 marker loci have been found. The nature of these correlations and the possibility of chromosomal mapping of genetic markers are discussed.     

Study of changes in life zone distribution in north-east China by climate–vegetation classification

Life zones and their changes in distribution in north-east China were studied based on climate–vegetation relationships. The warmth index (WI) and aridity index (the ratio of evaporation [evaporation rate, ER] to precipitation) were used to represent the site condition. The typical site condition of each vegetation type was determined as the classification criterion. The boundaries of the four potential vegetation zones were estimated based on the combinations of WI and ER in relation to vegetation (i.e. cold-temperate conifer forest zone, temperate broad-leaved conifer mixed forest zone, warm-temperate deciduous forest zone, and temperate steppe zone). The distribution changes in vegetation zone caused by human activities were estimated by comparing the potential vegetation with the actual one. The percentage cover of forest has shrunk from about 70% to the present 27%. About 23% of the study area was replaced by agricultural vegetation and industrial use. Nearly half of the region could have been covered by broad-leaved conifer mixed forest which was shrunk to a small area, less than 5% of the region. The broad-leaved deciduous forest zone in the southern part could have occupied about 7% of the area, and had almost no virgin stand.     

Determination of pyrrole–imidazole polyamide in rat plasma by liquid chromatography–tandem mass spectrometry

Pyrrole (Py)–imidazole (Im) polyamides synthesized by combining N-methylpyrrole and N-methylimidazole amino acids have been identified as novel candidates for gene therapy. In this study, a sensitive method using liquid chromatography–tandem mass spectrometry (LC–MS/MS) with an electrospray ionization (ESI) source was developed and validated for the determination and quantification of Py–Im polyamide in rat plasma. Py–Im polyamide was extracted from rat plasma by solid-phase extraction (SPE) using a Waters Oasis^® HLB cartridge. Separation was achieved on an ACQUITY UPLC HSS T3 (1.8 μm, 2.1 × 50 mm) column by gradient elution using acetonitrile:distilled water:acetic acid (5:95:0.1, v/v/v) and acetonitrile:distilled water:acetic acid (95:5:0.1, v/v/v). The method was validated over the range of 10–1000 ng/mL and the lower limit of quantification (LLOQ) was 10 ng/mL. This method was successfully applied to the investigation of the pharmacokinetics of Py–Im polyamide after intravenous administration.     

Analysis of corticosteroids in equine urine by liquid chromatography–mass spectrometry

A liquid chromatography–mass spectrometry (LC–MS) method for the analysis of corticosteroids in equine urine was developed. Corticosteroid conjugates were hydrolysed with β-glucuronidase; free and enzyme-released corticosteroids were then extracted from the samples with ethyl acetate followed by a base wash. The isolated corticosteroids were detected by LC–MS and confirmed by LC–MS–MS in the positive atmospheric pressure chemical ionisation mode. Twenty-three corticosteroids (comprising hydrocortisone, deoxycorticosterone and 21 synthetic corticosteroids), each at 5 ng/ml in urine, could easily be analysed in 10 min.     

Quantification of gentamicin in Mueller–Hinton agar by high-performance liquid chromatography

The aim of this study was to optimise a method for gentamicin determination in an agar matrix and to investigate if and how agar composition can affect the gentamicin diffusion kinetics during the agar diffusion tests for antibiotics sensitivity. Gentamicin was separated by RP-HPLC and detected at 365 nm after pre-column derivatization with 1-fluoro-2,4-dinitrobenzene. Recovery (≥79%), linearity (r²≥0.997) and sensitivity (1 μg/ml) were assessed using four different agar matrices. The kinetics of gentamicin diffusion tested on BioMerieux and DID manufacturers’ products showed in uninoculated agar plates significant differences that were even more pronounced in the presence of Pseudomonas aeruginosa metabolism.     

Beckwith–Wiedemann syndrome prenatal diagnosis by methylation analysis in chorionic villi

Beckwith–Wiedemann syndrome (BWS) is an imprinting disorder that can be prenatally suspected or diagnosed based on established clinical guidelines. Molecular confirmation is commonly performed on amniocytes. The possibility to use fresh (CVF) and cultured (CVC) chorionic villi has never been investigated. To verify whether CVF and CVC are reliable sources of DNA to study fetal methylation, we used pyrosequencing to test the methylation level of a number of differentially methylated regions (DMRs) at several imprinted loci (ICR1, ICR2, H19, PWS/AS-ICR, GNASXL, GNAS1A, ZAC/PLAGL1, and MEST) and at non-imprinted MGMT and RASSF1A promoters. We analyzed these regions in 19 healthy pregnancies and highlighted stable methylation levels between CVF and CVC at ICR1, ICR2, GNASXL, PWS/AS-ICR, and MEST. Conversely, the methylation levels at H19 promoter, GNAS1A and ZAC/PLAGL1 were different in CVC compared to fresh CV. We also investigated ICR1 and ICR2 methylation level of CVF/CVC of 2 BWS-suspected fetuses (P1 and P2). P1 showed ICR2 hypomethylation, P2 showed normal methylation at both ICR1 and ICR2. Our findings, although limited to one case of BWS fetus with an imprinting defect, can suggest that ICR1 and ICR2, but not H19, could be reliable targets for prenatal BWS diagnosis by methylation test in CVF and CVC. In addition, PWS/AS-ICR, GNASXL, and MEST, but not GNAS1A and ZAC/PLAGL1, are steadily hemimethylated in CV from healthy pregnancies, independently from culture. Thus, prenatal investigation of genomic imprinting in CV needs to be validated in a locus-specific manner.