Expression and plasma membrane localization of the mammalian B‐cell receptor complex in transgenic Nicotiana tabacum

The B‐cell antigen receptor (BCR), displayed on the plasma membrane of mature B cells of the mammalian immune system, is a multimeric complex consisting of a membrane‐bound immunoglobulin (mIg) noncovalently associated with the Igα/Igβ heterodimer. In this study, we engineered transgenic tobacco plants expressing all four chains of the BCR. ELISA, Western blotting and confocal microscopy demonstrated that the BCR was correctly assembled in plants, predominantly in the plasma membrane, and that the noncovalent link was detergent sensitive. This is the first example of a noncovalently assembled plasma membrane‐retained heterologous receptor in plants. In B cells of the mammalian immune system, following antigen binding to mIg, BCR is internalized and tyrosine residues on Igα and Igβ are phosphorylated activating a signaling cascade through interaction with protein kinases that ultimately leads to the initiation of gene expression. Expression of the BCR may therefore be an important tool for the study of plant endocytosis and the identification of previously unknown plant tyrosine kinases. The specificity and diversity of the antibody repertoire, coupled to the signal transduction capability of the Igα/Igβ heterodimer, also indicates that plants expressing BCR may in future be developed as environmental biosensors.     

Stacking small segments of the 1D chromosome of bread wheat containing major gluten quality genes into durum wheat: transfer strategy and breeding prospects

Using a chromosome engineering strategy, we previously developed two durum wheat recombinant lines, each containing on chromosome 1A a short segment of bread wheat chromosome 1D with either the Glu-D1 (PL line) or the Gli-D1/Glu-D3 (PS line) genes. Since PL and PS transfers produced substantial but different effects on durum gluten properties, in the present work stacking of their 1DS and 1DL segments into the same chromosome 1A was undertaken to investigate their combined effect in durum wheat and to potentially widen the spectrum of the crop end-uses. Development of genetic and genomic in situ hybridization (GISH)-based physical maps of PS and PL recombinant arms facilitated selection of carriers of the double-recombinant (PS?+?PL) 1A chromosome among F₂ progeny from the PS?×?PL cross. With the 1DS transfer spanning the terminal 17% of recombinant 1AS, and the interstitial 1DL segment occupying 16% of recombinant 1AL, PS?+?PL chromosomes were generated by pairing events occurred with a 68.4% frequency in 1A regions shared by parental chromosomes. Homozygous double-recombinant F₃ plants exhibited no significant differences for relevant agronomic traits compared to sib lines possessing either one or no 1D segment. Among quality parameters preliminarily assessed, SDS sedimentation values increased by 12% in PS and by over 32 and 38% in PL and PS?+?PL lines, respectively, compared to null controls. As a whole, the novel recombinant genotype offers good prospects for direct exploitation in breeding, and hence for an effective contribution to the enhancement of the crop value.     

Determination of the absolute configurations of flexible molecules: synthesis and theoretical simulation of electronic circular dichroism/optical rotation of some pyrrolo[2,3-b]indoline alkaloids--a case study

The paper describes the synthesis and chiroptical properties of (-)-1,2,3,3a,8,8a,-hexahydro-1,3a-dimethyl-pyrrolo[2,3-b]indole, (-)-1, one of the monomeric units of many flexible polypyrroloindoline alkaloids and (-)-chimonanthine, (-)-2. The aim of this investigation is to show that, under certain circumstances, namely, with molecules for which the sign and order of magnitude of [alpha](D) are determined by the lowest-energy valence-shell transitions (referred to as class (a) molecules), a small basis set calculation of chiroptical properties provides reliable results, and that such a treatment can be employed for absolute configurational assignment of larger oligomers, for which the increased flexibility renders the analysis as formidable task. Actually, as the aforementioned two molecules belong to class (a) systems, a TDDFT/B3LYP/6-31G* calculation of the ECD and ORD spectra gives rise to a more than satisfactory simulation of these data, assuming the reported absolute configurations. In other words, the use of the TDDFT/B3LYP method with the small 6-31G* basis set enables one to treat large and flexible molecules such as (-)-2 (52 atoms and 6 conformers) by usage of a simple PC in about 2 weeks. This protocol demonstrates that an ab initio prediction of ECD/ORD spectra results in reliable assignments of absolute configuration of even relatively large natural products, thus economizing computation time.     

Preferring thin people does not imply derogating fat people. A rasch analysis of the implicit weight attitude

Objective:

The meaning of the implicit weight attitude in individuals of different weight by distinguishing the contribution of positive and negative associations to the overall measure was investigated.

Design and Methods:

The implicit weight attitude was assessed using the Implicit Association Test. A Rasch model was used to identify which stimuli most affected the implicit measure. Explicit attitudes were assessed with a thin‐fat preference scale, and thermometer scales for both thin and fat people. The sample consists of 510 individuals categorized according to their BMI.

Results and Conclusion:

A significant implicit preference for thin relative to fat people was observed in all weight groups. In normal weight and obese individuals, the preference was mostly affected by positive stimuli (more easily associated with thin than with fat people). In underweight individuals, the preference was mostly guided by positive (more easily associated with thin than with fat people) and negative (more easily associated with fat than with thin people) stimuli. In overweight individuals, all stimuli contributed to the preference in a similar way. In all weight groups, the implicit weight attitude correlated with the explicit preference and/or the thin thermometer, whereas it never correlated with the fat thermometer. A pro‐thin bias was observed in normal weight and obese individuals, whereas both a pro‐thin and an anti‐fat bias were observed in underweight individuals. A clear preference for thin people relative to fat people was observed in overweight individuals. Therefore, uncritically interpreting the implicit preference for thin people as a sign of derogating fat people might be misleading.     

External quality assessment of cytomegalovirus DNA detection on dried blood spots

Background  

Testing for viral DNA in neonatal blood dried on paper (DBS) has proved a valid means of diagnosing congenital CMV infection with both clinical and epidemiological relevance. To assess the quality of the detection of CMV-DNA on DBS in laboratories performing this test a proficiency panel consisting of nine samples with two blood spots on each filter paper was produced and distributed. Six samples were derived from whole blood, negative for CMV DNA and antibody, and spiked with cell-grown CMV Towne in various concentrations (7.3 × 10² - 9.6 × 10⁵ copies/ml), one was a CMV positive clinical specimen (3.9 × 10⁶ copies/ml), and two samples were CMV-negative whole blood.     

An allele of HRAS1 3'variable number of tandem repeats is a frailty allele: implication for an evolutionarily-conserved pathway involved in longevity

The human HRAS1 belongs to an evolutionarily-conserved family of genes which enrolls among its members the yeast RAS2, a gene which regulates stress response and longevity in the Saccharomyces cerevisiae. In this paper we report that the frequency of the a3 allele of HRAS1 3'variable number tandem repeat (HRAS1 3'VNTR) decreases in centenarians in respect to young people, and we estimate that during aging a3 carriers have a relative mortality risk of 1.126 (95% CI=1.044-1.213). We propose that the germ-line variability at the HRAS1 locus impacts on the individual's capacity to reach the extreme limits of human life-span. Furthermore, we provide suggestive evidence that a3 HRAS1 3'VNTR allele and inherited variants of the mitochondrial genome (mtDNA haplogroups) do not affect independently human longevity, thus recalling the nucleus-mitochondrion interaction which regulates stress response and life-span in the yeast.     

Impact of fire and the recovery of molluscs in south‐east Australian salt marsh

Fire has long been recognised as a natural force in structuring Northern Hemisphere salt marshes, yet little is known about the impact of fire on molluscs and native vegetation dynamics of Southern Hemisphere coastal salt marshes. Following a fire at Ash Island, Hunter River New South Wales, Australia in the summer 2012, we assessed patterns of recovery through time of gastropod populations and resident salt marsh vegetation including biomass for three keystone native plant species, Native Rush (Juncus kraussii Hochst.), a chenopod (Sarcocornia quinqueflora Bunge ex Ungen‐Sternberg A.J. Scott), Salt Couch (Sporobolus virginicus, L. Kunth) and the invasive Spiny Rush (Juncus acutus). In temperate east‐coast Australian salt marshes, Spiny Rush is displacing native salt marsh vegetation. After twelve months, the biomass of Native Rush recovered to similar pre‐burn levels. While fire affected the abundance, richness and composition of the gastropod assemblage differences were also largely driven by spatial variability. Gastropod assemblages associated with two of the higher elevation native species (Native Rush and Salt Couch) were impacted the most by fire. Greater abundance (between 1 and 5 orders of magnitude difference in abundance) and richness of gastropods were found in unburnt compared with burnt Native Rush and Salt Couch vegetation, while more gastropods were found in Spiny Rush in one site. Species prevalent in burnt vegetation included larger species of gastropods Ophicardelus ornatus (Ferussac, 1821) and Phallomedusa solida (Martens, 1878) with an unexpected spike in number of the smaller gastropod Tatea huonensis (Tenison‐Woods, 1876) in the spiny rush at one site only. In salt marsh habitats, many gastropods have planktonic larval dispersal stages which are dependent on the tidal height for transport and the structural complexity provided by vegetation at settlement. Since fire appears to negatively affect salt marsh gastropod populations within structurally complex Native Rush and Salt Couch, due consideration of the importance of these refuges for gastropods is recommended when fire or other disturbances occur in ecologically endangered salt marsh in the Southern Hemisphere. Managers need to consider spatial heterogeneity of molluscs and their recovery in the event of fire in Southern Hemisphere salt marshes.     

Individual differences in subjective and objective alertness during sleep deprivation are stable and unrelated

This study examines the individual reproducibility of alterations of subjective, objective, and EEG measures of alertness during 27 h of continuous wakefulness and analyzes their interrelationships. Eight subjects were studied twice under similar constant-routine conditions. Scales and performance tasks were administered at hourly intervals to define temporal changes in subjective and objective alertness. The wake EEG was recorded every 2 h, 2 min with eyes open and 2 min with eyes closed. Plasma glucose and melatonin levels were measured to estimate brain glucose utilization and individual circadian phase, respectively. Decrements of subjective alertness and performance deficits were found to be highly reproducible for a given individual. Remarkably, there was no relationship between the impairments of subjective and objective alertness. With increased duration of wakefulness, EEG activity with eyes closed increased in the delta range and decreased in the alpha range, but the magnitudes of these changes were also unrelated. These findings indicate that sleep deprivation has highly reproducible, but independent, effects on brain mechanisms controlling subjective and objective alertness.     

Autochthonous and migratory birds as a dispersion source for Ixodes ricinus in southern Italy

The present study was carried out in a protected wooded area, which is part of the Parco Regionale Gallipoli Cognato Piccole Dolomiti Lucane, one of the most important ecological reserves in southern Italy. From April 2010 to April 2011, 212 birds, comprising 22 species from 12 families, were captured and examined for ticks. A total of 75 (35.4?%) birds were found infested by ticks, with 451 ticks being collected. All ticks were identified as Ixodes ricinus, of which 241 (53.4?%) were larvae and 210 nymphs (46.6?%). The highest intensity of infestation was found in April 2010, when 117 ticks were retrieved on 25 birds. No ticks were found on birds (n?=?5) netted in December 2010. High infestation rates were recorded on blackbirds (Turdus merula) (90 %; 29 birds examined) and on mistle thrushes (Turdus viscivorus) (100?%; 2 birds examined). The highest intensity of infestation by larvae was found on wrens (5.6 larvae/bird) and by nymphs on mistle thrushes (11.5 nymphs/bird). Temperature and number of hours of light showed to influence the activity of larvae and nymphs. These data support the notion that birds may be responsible for the heterogeneous distribution of I. ricinus in Europe, thus playing a role in the epidemiology of certain tick-borne pathogens.