Characteristics of the relative maximum in the decay of delayed light emission from Pothos leaf following far-red excitation

Following illumination with wavelengths longer than 700 nm, the intensity of light emission from Pothos aurea leaf falls for 1 min and then increases to a maximum after 2 min in the dark. The spectrum of this minute-range liminescence matches that of prompt fluorescence excited at the same wavelength, but differs from that of prompt or minute-range delayed emission excited by wavelengths shorter than 700 nm. This emission is less sensitive to heat damage than millisecond delayed emission, and may originate from photosystem I.     

Purification of the glycoprotein lectin from the broad bean (Vicia faba) and a comparison of its properties with lectins of similar specificity.

1. The lectin from the broad bean (Vicia faba) was purified by affinity chromatography by using 3-O-methylglucosamine covalently attached through the amino group to CH-Sepharose (an omega-hexanoic acid derivative of agarose). Its composition and the nature of its subunits were compared with concanavalin A and the lectins from pea and lentil. 2. Unlike the other three lectins, broad-bean lectin is a glycoprotein; a glycopeptide containing glucosamine and mannose was isolated from a proteolytic digest. 3. The mol.wt. is about 47500; the glycoprotein consists of two apprently identical subunits, held together by non-covalent forces. Fragments of the subunits, similar to those found in concanavalin A and soya-bean agglutinin, were found in active preparations. 4. Broad-bean lectin was compared with concanavalin A and the lectins from pea and lentil in an investigation of the inhibition of their action by a number of monosaccharides, methyl ethers of monosaccharides, disaccharides and glycopeptides. The most striking differences concern 3-O-substituted monosaccharides, which are strong inhibitors of the action of broad-bean, pea and lentil lectins but not of the action of concanavalin A. There is, however, no strong inhibition of the action of these lectins by 3-Olinked disaccharides.     

Genetic influences in self-reported symptoms of obstructive sleep apnoea and restless legs: a twin study.

Sleep disorders, such as obstructive sleep apnoea (OSA) and restless legs syndrome (RLS), are very common. The relative importance of genetic and nongenetic (environmental) influences on the symptomatology of these conditions has not been well studied. This study uses the twin design to examine this by evaluating OSA and RLS symptoms in monozygotic (MZ) and dizygotic (DZ) twins. Six thousand six hundred unselected female twin pairs, identified from a national volunteer twin register, were asked to complete a medical questionnaire. This questionnaire included questions on OSA and RLS symptoms, as well as questions on subject demographics, past medical history, smoking history and menopausal status. Responses were obtained from 4503 individuals (68% response rate). A total of 1937 twin pairs were evaluable: 933 MZ pairs (mean [range] age 51 [20-76] years) and 1004 DZ pairs (age 51 [20-80] years). Concordance rates were higher for MZ than DZ twins for OSA and RLS symptoms. Multifactorial liability threshold modeling suggests that additive genetic effects combined with unique environmental factors provide the best model for OSA and RLS symptoms. Heritability was estimated to be 52% (95% confidence interval 36% to 68%) for disruptive snoring, 48% (37% to 58%) for daytime sleepiness, 54% (44% to 63%) for restless legs, and 60% (51% to 69%) for legs jerking. These estimates dropped only slightly after adjustment for potential confounding influences on the symptoms of snoring and daytime sleepiness. These results suggest a substantial genetic contribution to the symptomatology of OSA and RLS. More research is needed to identify the genes responsible, and may ultimately lead to new therapies.     

Virulence of 32 Salmonella strains in mice

Virulence and persistence in the BALB/c mouse gut was tested for 32 strains of Salmonella enterica for which genome sequencing is complete or underway, including 17 serovars within subspecies I (enterica), and two representatives of each of the other five subspecies. Only serovar Paratyphi C strain BAA1715 and serovar Typhimurium strain 14028 were fully virulent in mice. Three divergent atypical Enteritidis strains were not virulent in BALB/c, but two efficiently persisted. Most of the other strains in all six subspecies persisted in the mouse intestinal tract for several weeks in multiple repeat experiments although the frequency and level of persistence varied considerably. Strains with heavily degraded genomes persisted very poorly, if at all. None of the strains tested provided immunity to Typhimurium infection. These data greatly expand on the known significant strain-to-strain variation in mouse virulence and highlight the need for comparative genomic and phenotypic studies.     

Beyond ecosystem modeling: A roadmap to community cyberinfrastructure for ecological data‐model integration

In an era of rapid global change, our ability to understand and predict Earth's natural systems is lagging behind our ability to monitor and measure changes in the biosphere. Bottlenecks to informing models with observations have reduced our capacity to fully exploit the growing volume and variety of available data. Here, we take a critical look at the information infrastructure that connects ecosystem modeling and measurement efforts, and propose a roadmap to community cyberinfrastructure development that can reduce the divisions between empirical research and modeling and accelerate the pace of discovery. A new era of data‐model integration requires investment in accessible, scalable, and transparent tools that integrate the expertise of the whole community, including both modelers and empiricists. This roadmap focuses on five key opportunities for community tools: the underlying foundations of community cyberinfrastructure; data ingest; calibration of models to data; model‐data benchmarking; and data assimilation and ecological forecasting. This community‐driven approach is a key to meeting the pressing needs of science and society in the 21st century.     

PEGylation of lysine residues improves the proteolytic stability of fibronectin while retaining biological activity

Excessive proteolysis of fibronectin (FN) impairs tissue repair in chronic wounds. Since FN is essential in wound healing, our goal is to improve its proteolytic stability and at the same time preserve its biological activity. We have previously shown that reduced FN conjugated with polyethylene glycol (PEG) at cysteine residues is more proteolytically stable than native FN. Cysteine‐PEGylated FN supported cell adhesion and migration to the same extent as native FN. However, unlike native FN, cysteine‐PEGylated FN was not assembled into an extracellular matrix (ECM) when immobilized. Here, we present an alternative approach in which FN is preferentially PEGylated at lysine residues using different molecular weight PEGs. We show that lysine PEGylation does not perturb FN secondary structure. PEG molecular weight, from 2 to 10 kDa, positively correlates with FN–PEG proteolytic stability. Cell adhesion, cell spreading, and gelatin binding decrease with increasing molecular weight of PEG. The 2‐kDa FN–PEG conjugate shows comparable cell adhesion to native FN and binds gelatin. Moreover, immobilized FN–PEG is assembled into ECM fibrils. In summary, lysine PEGylation of FN can be used to stabilize FN against proteolytic degradation with minimal perturbation to FN structure and retained biological activity.     

Assessing the wellbeing of cytoscreeners: experience in two NHS cytology laboratories

OBJECTIVE: Cervical screening programmes in England are in transition as the liquid-based cytology (LBC) method replaces conventional Papanicolaou screening and staff in NHS laboratories are trained to analyse LBC smears. Cytoscreeners and biomedical scientists undertake routine microscopy of slides, but the scientists usually have a wider professional role. Attitudinal surveys were carried out in laboratories where LBC was partially introduced. METHODS: Staff in two cytology laboratories in Greater Manchester were surveyed twice over 6 months. The questionnaire assessed work pressures using scales from the Measures of Work Characteristics instrument, work-related stress using the General Survey version of the Maslach Burnout Inventory, job intentions and job satisfaction. RESULTS: Cytoscreeners, many aged over 50 years, formed over 60% of respondents in both surveys (27/42 in the first survey), and biomedical scientists and doctors, 30%. Both groups were under moderate pressure from work demands in each survey, but cytoscreeners had significantly less autonomy over their working methods (P < 0.001). Although both groups experienced similar levels of exhaustion, cytoscreeners were much more cynical or indifferent towards work in the second survey (P = 0.008) and had lower expectations of being effective (P < 0.001). For the cytoscreeners, there were strong negative correlations in both surveys between cynicism and the work characteristics of influencing decisions and autonomy/control. CONCLUSIONS: The strength of the relationship between work performance and wellbeing serves to emphasize the importance of the new LBC technology in ameliorating low morale where it exists. Further attitudinal research involving larger samples of laboratories is warranted to assess the full impact of this innovation.