Structural Requirement in Clostridium perfringens Collagenase mRNA 5′ Leader Sequence for Translational Induction through Small RNA-mRNA Base Pairing

PubMed Central

Nomura, Nobuhiko; Nakamura, Kouji

2013-01-01

The Gram-positive anaerobic bacterium Clostridium perfringens is pathogenic to humans and animals, and the production of its toxins is strictly regulated during the exponential phase. We recently found that the 5′ leader sequence of the colA transcript encoding collagenase, which is a major toxin of this organism, is processed and stabilized in the presence of the small RNA VR-RNA. The primary colA 5′-untranslated region (5′UTR) forms a long stem-loop structure containing an internal bulge and masks its own ribosomal binding site. Here we found that VR-RNA directly regulates colA expression through base pairing with colA mRNA in vivo. However, when the internal bulge structure was closed by point mutations in colA mRNA, translation ceased despite the presence of VR-RNA. In addition, a mutation disrupting the colA stem-loop structure induced mRNA processing and ColA-FLAG translational activation in the absence of VR-RNA, indicating that the stem-loop and internal bulge structure of the colA 5′ leader sequence is important for regulation by VR-RNA. On the other hand, processing was required for maximal ColA expression but was not essential for VR-RNA-dependent colA regulation. Finally, colA processing and translational activation were induced at a high temperature without VR-RNA. These results suggest that inhibition of the colA 5′ leader structure through base pairing is the primary role of VR-RNA in colA regulation and that the colA 5′ leader structure is a possible thermosensor. PMID:23585542

Evidence for Context-Dependent Complementarity of Non-Shine-Dalgarno Ribosome Binding Sites to Escherichia coli rRNA

PubMed Central

Barendt, Pamela A.; Shah, Najaf A.; Barendt, Gregory A.; Kothari, Parth A.; Sarkar, Casim A.

2013-01-01

While the ribosome has evolved to function in complex intracellular environments, these contexts do not easily allow for the study of its inherent capabilities. We have used a synthetic, well-defined, Escherichia coli (E. coli)-based translation system in conjunction with ribosome display, a powerful in vitro selection method, to identify ribosome binding sites (RBSs) that can promote the efficient translation of messenger RNAs (mRNAs) with a leader length representative of natural E. coli mRNAs. In previous work, we used a longer leader sequence and unexpectedly recovered highly efficient cytosine-rich sequences with complementarity to the 16S ribosomal RNA (rRNA) and similarity to eukaryotic RBSs. In the current study, Shine-Dalgarno (SD) sequences were prevalent but non-SD sequences were also heavily enriched and were dominated by novel guanine- and uracil-rich motifs which showed statistically significant complementarity to the 16S rRNA. Additionally, only SD motifs exhibited position-dependent decreases in sequence entropy, indicating that non-SD motifs likely operate by increasing the local concentration of ribosomes in the vicinity of the start codon, rather than by a position-dependent mechanism. These results further support the putative generality of mRNA-rRNA complementarity in facilitating mRNA translation, but also suggest that context (e.g., leader length and composition) dictates the specific subset of possible RBSs that are used for efficient translation of a given transcript. PMID:23427812

NMR studies of two spliced leader RNAs using isotope labeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lapham, J.; Crothers, D.M.

1994-12-01

Spliced leader RNAs are a class of RNA molecules (<200 nts) involved in the trans splicing of messenger RNA found in trypanosomes, nematodes, and other lower eukaryotes. The spliced leader RNA from the trypanosome Leptomonas Collosoma exists in two alternate structural forms with similar thermal stabilities. The 54 nucleotides on the 5{prime} end of the SL molecule is structurally independent from the 3{prime} half of the RNA, and displays the two structural forms. Furthermore, the favored of the two structures was shown to contain anomalous nuclease sensitivity and thermal stability features, which suggests that there may be tertiary interactions betweenmore » the splice site and other nucleotides in the 5{prime} end. Multidimensional NMR studies are underway to elucidate the structural elements present in the SL RNAs that give rise to their physical properties. Two spliced leader sequences have been studied. The first, the 54 nucleotides on the 5{prime} end of the L. Collosoma sequence, was selected because of earlier studies in our laboratory. The second sequence is the 5{prime} end of the trypanosome Crithidia Fasciculata, which was chosen because of its greater sequence homology to other SL sequences. Given the complexity of the NMR spectra for RNA molecules of this size, we have incorporated {sup 15}N/{sup 13}C-labeled nucleotides into the RNA. One of the techniques we have developed to simplify the spectra of these RNA molecules is isotope labeling of specific regions of the RNA. This has been especially helpful in assigning the secondary structure of molecules that may be able to adopt multiple conformations. Using this technique one can examine a part of the molecule without spectral interference from the unlabeled portion. We hope this approach will promote an avenue for studying the structure of larger RNAs in their native surroundings.« less

Short ORF-Dependent Ribosome Shunting Operates in an RNA Picorna-Like Virus and a DNA Pararetrovirus that Cause Rice Tungro Disease

PubMed Central

Pooggin, Mikhail M.; Rajeswaran, Rajendran; Schepetilnikov, Mikhail V.; Ryabova, Lyubov A.

2012-01-01

Rice tungro disease is caused by synergistic interaction of an RNA picorna-like virus Rice tungro spherical virus (RTSV) and a DNA pararetrovirus Rice tungro bacilliform virus (RTBV). It is spread by insects owing to an RTSV-encoded transmission factor. RTBV has evolved a ribosome shunt mechanism to initiate translation of its pregenomic RNA having a long and highly structured leader. We found that a long leader of RTSV genomic RNA remarkably resembles the RTBV leader: both contain several short ORFs (sORFs) and potentially fold into a large stem-loop structure with the first sORF terminating in front of the stem basal helix. Using translation assays in rice protoplasts and wheat germ extracts, we show that, like in RTBV, both initiation and proper termination of the first sORF translation in front of the stem are required for shunt-mediated translation of a reporter ORF placed downstream of the RTSV leader. The base pairing that forms the basal helix is required for shunting, but its sequence can be varied. Shunt efficiency in RTSV is lower than in RTBV. But in addition to shunting the RTSV leader sequence allows relatively efficient linear ribosome migration, which also contributes to translation initiation downstream of the leader. We conclude that RTSV and RTBV have developed a similar, sORF-dependent shunt mechanism possibly to adapt to the host translation system and/or coordinate their life cycles. Given that sORF-dependent shunting also operates in a pararetrovirus Cauliflower mosaic virus and likely in other pararetroviruses that possess a conserved shunt configuration in their leaders it is tempting to propose that RTSV may have acquired shunt cis-elements from RTBV during their co-existence. PMID:22396650

Periplasmic expression of human interferon-alpha 2c in Escherichia coli results in a correctly folded molecule.

PubMed Central

Voss, T; Falkner, E; Ahorn, H; Krystek, E; Maurer-Fogy, I; Bodo, G; Hauptmann, R

1994-01-01

Human interferon-alpha 2c (IFN-alpha 2c) was produced in Escherichia coli under the control of the alkaline phosphatase promoter using a periplasmic expression system. Compared with other leader sequences, the heat-stable enterotoxin II leader of E. coli (STII) resulted in the highest rate of correct processing as judged by Western-blot analysis. The fermentation was designed as a batch-fed process in order to obtain a high yield of biomass. The processing rate of IFN-alpha 2c could be increased from 25% to more than 50% by shifting the fermentation pH from 7.0 to 6.7. IFN-alpha 2c extracted from the periplasm was purified by a new four-step chromatographic procedure. Whereas cytoplasmically produced IFN-alpha 2c does not have its full native structure, IFN-alpha 2c extracted from the periplasm was found to be correctly folded, as shown by c.d. spectroscopy. Peptide-map analysis in combination with m.s. revealed the correct formation of disulphide bridges. N-terminal sequence analysis showed complete removal of the leader sequence, creating the authentic N-terminus starting with cysteine. Images Figure 3 Figure 4 Figure 6 PMID:8141788

Unusually long-lived pause required for regulation of a Rho-dependent transcription terminator

PubMed Central

Hollands, Kerry; Sevostiyanova, Anastasia; Groisman, Eduardo A.

2014-01-01

Up to half of all transcription termination events in bacteria rely on the RNA-dependent helicase Rho. However, the nucleic acid sequences that promote Rho-dependent termination remain poorly characterized. Defining the molecular determinants that confer Rho-dependent termination is especially important for understanding how such terminators can be regulated in response to specific signals. Here, we identify an extraordinarily long-lived pause at the site where Rho terminates transcription in the 5′-leader region of the Mg2+ transporter gene mgtA in Salmonella enterica. We dissect the sequence elements required for prolonged pausing in the mgtA leader and establish that the remarkable longevity of this pause is required for a riboswitch to stimulate Rho-dependent termination in the mgtA leader region in response to Mg2+ availability. Unlike Rho-dependent terminators described previously, where termination occurs at multiple pause sites, there is a single site of transcription termination directed by Rho in the mgtA leader. Our data suggest that Rho-dependent termination events that are subject to regulation may require elements distinct from those operating at constitutive Rho-dependent terminators. PMID:24778260

CRISPRFinder: a web tool to identify clustered regularly interspaced short palindromic repeats.

PubMed

Grissa, Ibtissem; Vergnaud, Gilles; Pourcel, Christine

2007-07-01

Clustered regularly interspaced short palindromic repeats (CRISPRs) constitute a particular family of tandem repeats found in a wide range of prokaryotic genomes (half of eubacteria and almost all archaea). They consist of a succession of highly conserved regions (DR) varying in size from 23 to 47 bp, separated by similarly sized unique sequences (spacer) of usually viral origin. A CRISPR cluster is flanked on one side by an AT-rich sequence called the leader and assumed to be a transcriptional promoter. Recent studies suggest that this structure represents a putative RNA-interference-based immune system. Here we describe CRISPRFinder, a web service offering tools to (i) detect CRISPRs including the shortest ones (one or two motifs); (ii) define DRs and extract spacers; (iii) get the flanking sequences to determine the leader; (iv) blast spacers against Genbank database and (v) check if the DR is found elsewhere in prokaryotic sequenced genomes. CRISPRFinder is freely accessible at http://crispr.u-psud.fr/Server/CRISPRfinder.php.

Biochemical and genetic characterization of enterocin A from Enterococcus faecium, a new antilisterial bacteriocin in the pediocin family of bacteriocins.

PubMed Central

Aymerich, T; Holo, H; Håvarstein, L S; Hugas, M; Garriga, M; Nes, I F

1996-01-01

A new bacteriocin has been isolated from an Enterococcus faecium strain. The bacteriocin, termed enterocin A, was purified to homogeneity as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, N-terminal amino acid sequencing, and mass spectrometry analysis. By combining the data obtained from amino acid and DNA sequencing, the primary structure of enterocin A was determined. It consists of 47 amino acid residues, and the molecular weight was calculated to be 4,829, assuming that the four cysteine residues form intramolecular disulfide bridges. This molecular weight was confirmed by mass spectrometry analysis. The amino acid sequence of enterocin A shared significant homology with a group of bacteriocins (now termed pediocin-like bacteriocins) isolated from a variety of lactic acid-producing bacteria, which include members of the genera Lactobacillus, Pediococcus, Leuconostoc, and Carnobacterium. Sequencing of the structural gene of enterocin A, which is located on the bacterial chromosome, revealed an N-terminal leader sequence of 18 amino acid residues, which was removed during the maturation process. The enterocin A leader belongs to the double-glycine leaders which are found among most other small nonlantibiotic bacteriocins, some lantibiotics, and colicin V. Downstream of the enterocin A gene was located a second open reading frame, encoding a putative protein of 103 amino acid residues. This gene may encode the immunity factor of enterocin A, and it shares 40% identity with a similar open reading frame in the operon of leucocin AUL 187, another pediocin-like bacteriocin. PMID:8633865

The academic story: introducing the clinical nurse leader role in a multifacility health care system.

PubMed

Moore, Penny

2013-01-01

Introducing the clinical nurse leader (CNL) role in a multifacility health care system is an exciting but obstacle-filled journey. This story includes facilitating factors, opportunities, and successes plus suggestions for other academic-practice partners considering implementing the CNL role. A sample course sequence with course descriptions is provided. Copyright © 2013 Elsevier Inc. All rights reserved.

Genome-Wide Reprogramming of Transcript Architecture by Temperature Specifies the Developmental States of the Human Pathogen Histoplasma

PubMed Central

Gilmore, Sarah A.; Voorhies, Mark; Gebhart, Dana; Sil, Anita

2015-01-01

Eukaryotic cells integrate layers of gene regulation to coordinate complex cellular processes; however, mechanisms of post-transcriptional gene regulation remain poorly studied. The human fungal pathogen Histoplasma capsulatum (Hc) responds to environmental or host temperature by initiating unique transcriptional programs to specify multicellular (hyphae) or unicellular (yeast) developmental states that function in infectivity or pathogenesis, respectively. Here we used recent advances in next-generation sequencing to uncover a novel re-programming of transcript length between Hc developmental cell types. We found that ~2% percent of Hc transcripts exhibit 5’ leader sequences that differ markedly in length between morphogenetic states. Ribosome density and mRNA abundance measurements of differential leader transcripts revealed nuanced transcriptional and translational regulation. One such class of regulated longer leader transcripts exhibited tight transcriptional and translational repression. Further examination of these dually repressed genes revealed that some control Hc morphology and that their strict regulation is necessary for the pathogen to make appropriate developmental decisions in response to temperature. PMID:26177267

Genome-Wide Reprogramming of Transcript Architecture by Temperature Specifies the Developmental States of the Human Pathogen Histoplasma.

PubMed

Gilmore, Sarah A; Voorhies, Mark; Gebhart, Dana; Sil, Anita

2015-07-01

Eukaryotic cells integrate layers of gene regulation to coordinate complex cellular processes; however, mechanisms of post-transcriptional gene regulation remain poorly studied. The human fungal pathogen Histoplasma capsulatum (Hc) responds to environmental or host temperature by initiating unique transcriptional programs to specify multicellular (hyphae) or unicellular (yeast) developmental states that function in infectivity or pathogenesis, respectively. Here we used recent advances in next-generation sequencing to uncover a novel re-programming of transcript length between Hc developmental cell types. We found that ~2% percent of Hc transcripts exhibit 5' leader sequences that differ markedly in length between morphogenetic states. Ribosome density and mRNA abundance measurements of differential leader transcripts revealed nuanced transcriptional and translational regulation. One such class of regulated longer leader transcripts exhibited tight transcriptional and translational repression. Further examination of these dually repressed genes revealed that some control Hc morphology and that their strict regulation is necessary for the pathogen to make appropriate developmental decisions in response to temperature.

Real-Time Culture Change Improves Lean Success: Sequenced Culture Change Gets Failing Grades.

PubMed

Kusy, Mitchell; Diamond, Marty; Vrchota, Scott

2015-01-01

Success with the Lean management system is rooted in a culture of stakeholder engagement and commitment. Unfortunately, many leaders view Lean as an "add-on" tool instead of one that requires a new way of thinking and approaching culture. This article addresses the "why, how, and what" to promote a Lean culture that works. We present a five-phased approach grounded in evidence-based practices of real-time culture change. We further help healthcare leaders understand the differences between traditional "sequenced" approaches to culture change and "real-time" methods--and why these real-time practices are more sustainable and ultimately more successful than traditional culture change methods.

Concentric Tube Robots as Steerable Needles: Achieving Follow-the-Leader Deployment.

PubMed

Gilbert, Hunter B; Neimat, Joseph; Webster, Robert J

2015-04-01

Concentric tube robots can enable new clinical interventions if they are able to pass through soft tissue, deploy along desired paths through open cavities, or travel along winding lumens. These behaviors require the robot to deploy in such a way that the curved shape of its shaft remains unchanged as the tip progresses forward (i.e., "follow-the-leader" deployment). Follow-the-leader deployment is challenging for concentric tube robots due to elastic (and particularly torsional) coupling between the tubes that form the robot. However, as we show in this paper, follow-the-leader deployment is possible, provided that tube precurvatures and deployment sequences are appropriately selected. We begin by defining follow-the-leader deployment and providing conditions that must be satisfied for a concentric tube robot to achieve it. We then examine several useful special cases of follow-the-leader deployment, showing that both circular and helical precurvatures can be employed, and provide an experimental illustration of the helical case. We also explore approximate follow-the-leader behavior and provide a metric for the similarity of a general deployment to a follow-the-leader deployment. Finally, we consider access to the hippocampus in the brain to treat epilepsy, as a motivating clinical example for follow-the-leader deployment.

Improving the genome annotation of the acarbose producer Actinoplanes sp. SE50/110 by sequencing enriched 5'-ends of primary transcripts.

PubMed

Schwientek, Patrick; Neshat, Armin; Kalinowski, Jörn; Klein, Andreas; Rückert, Christian; Schneiker-Bekel, Susanne; Wendler, Sergej; Stoye, Jens; Pühler, Alfred

2014-11-20

Actinoplanes sp. SE50/110 is the producer of the alpha-glucosidase inhibitor acarbose, which is an economically relevant and potent drug in the treatment of type-2 diabetes mellitus. In this study, we present the detection of transcription start sites on this genome by sequencing enriched 5'-ends of primary transcripts. Altogether, 1427 putative transcription start sites were initially identified. With help of the annotated genome sequence, 661 transcription start sites were found to belong to the leader region of protein-coding genes with the surprising result that roughly 20% of these genes rank among the class of leaderless transcripts. Next, conserved promoter motifs were identified for protein-coding genes with and without leader sequences. The mapped transcription start sites were finally used to improve the annotation of the Actinoplanes sp. SE50/110 genome sequence. Concerning protein-coding genes, 41 translation start sites were corrected and 9 novel protein-coding genes could be identified. In addition to this, 122 previously undetermined non-coding RNA (ncRNA) genes of Actinoplanes sp. SE50/110 were defined. Focusing on antisense transcription start sites located within coding genes or their leader sequences, it was discovered that 96 of those ncRNA genes belong to the class of antisense RNA (asRNA) genes. The remaining 26 ncRNA genes were found outside of known protein-coding genes. Four chosen examples of prominent ncRNA genes, namely the transfer messenger RNA gene ssrA, the ribonuclease P class A RNA gene rnpB, the cobalamin riboswitch RNA gene cobRS, and the selenocysteine-specific tRNA gene selC, are presented in more detail. This study demonstrates that sequencing of enriched 5'-ends of primary transcripts and the identification of transcription start sites are valuable tools for advanced genome annotation of Actinoplanes sp. SE50/110 and most probably also for other bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

Characteristics of negative lightning leaders to ground observed by TVLS

NASA Astrophysics Data System (ADS)

Qiu, Shi; Jiang, Zhidong; Shi, Lihua; Niu, Zhencong; Zhang, Peng

2015-12-01

The Thunder and VHF lightning Locating System (termed TVLS) is established and utilized to observe leader behaviors of negative cloud to ground (CG) flashes. This system takes advantages of VHF broadband interferometer and thunder imaging technique, which could provide the temporal and quasi-3D spatial evolution of lightning discharges. In conjunction with synchronized electric field changes (E-changes) and electric field derivatives (dE/dt) records, 10 leaders from two CG flashes are presented and analyzed. Based on the characteristic evolution of leader velocities, E-changes, dE/dt waveforms and VHF intervals, three stepped leaders, five dart leaders and two dart-stepped leaders are identified. The stepped leaders behave impulsive while approaching ground, with average speed (1.3∼3.9)×105 m/s. All normal dart leaders presented here exhibit irregular (or termed "chaotic") fluctuations in E-change and dE/dt waveforms, with the similar speeds ((1.0∼2.9)×107 m/s) and durations ((300∼700) μs) of the "chaotic" leaders observed by other investigators. The irregular fluctuations would be weak if the channels keep conductive until the leader enters the less conductive branches, coinciding with VHF radiations in time sequence. The dart-stepped leader could be divided into the dart stage and the stepped stage by a transition region, which usually lies around the branch junctions of previous active channel. The dart stage resembles the normal dart leader, and the stepped stage usually associates with regular pulse trains in E-change and dE/dt waveforms.

Concentric Tube Robots as Steerable Needles: Achieving Follow-the-Leader Deployment

PubMed Central

Gilbert, Hunter B.; Neimat, Joseph; Webster, Robert J.

2015-01-01

Concentric tube robots can enable new clinical interventions if they are able to pass through soft tissue, deploy along desired paths through open cavities, or travel along winding lumens. These behaviors require the robot to deploy in such a way that the curved shape of its shaft remains unchanged as the tip progresses forward (i.e., “follow-the-leader” deployment). Follow-the-leader deployment is challenging for concentric tube robots due to elastic (and particularly torsional) coupling between the tubes that form the robot. However, as we show in this paper, follow-the-leader deployment is possible, provided that tube precurvatures and deployment sequences are appropriately selected. We begin by defining follow-the-leader deployment and providing conditions that must be satisfied for a concentric tube robot to achieve it. We then examine several useful special cases of follow-the-leader deployment, showing that both circular and helical precurvatures can be employed, and provide an experimental illustration of the helical case. We also explore approximate follow-the-leader behavior and provide a metric for the similarity of a general deployment to a follow-the-leader deployment. Finally, we consider access to the hippocampus in the brain to treat epilepsy, as a motivating clinical example for follow-the-leader deployment. PMID:26622208

The spliced leader trans-splicing mechanism in different organisms: molecular details and possible biological roles

PubMed Central

Bitar, Mainá; Boroni, Mariana; Macedo, Andréa M.; Machado, Carlos R.; Franco, Glória R.

2013-01-01

The spliced leader (SL) is a gene that generates a functional ncRNA that is composed of two regions: an intronic region of unknown function (SLi) and an exonic region (SLe), which is transferred to the 5′ end of independent transcripts yielding mature mRNAs, in a process known as spliced leader trans-splicing (SLTS). The best described function for SLTS is to solve polycistronic transcripts into monocistronic units, specifically in Trypanosomatids. In other metazoans, it is speculated that the SLe addition could lead to increased mRNA stability, differential recruitment of the translational machinery, modification of the 5′ region or a combination of these effects. Although important aspects of this mechanism have been revealed, several features remain to be elucidated. We have analyzed 157 SLe sequences from 148 species from seven phyla and found a high degree of conservation among the sequences of species from the same phylum, although no considerable similarity seems to exist between sequences of species from different phyla. When analyzing case studies, we found evidence that a given SLe will always be related to a given set of transcripts in different species from the same phylum, and therefore, different SLe sequences from the same species would regulate different sets of transcripts. In addition, we have observed distinct transcript categories to be preferential targets for the SLe addition in different phyla. This work sheds light into crucial and controversial aspects of the SLTS mechanism. It represents a comprehensive study concerning various species and different characteristics of this important post-transcriptional regulatory mechanism. PMID:24130571

Cross-Species Functionality of Pararetroviral Elements Driving Ribosome Shunting

PubMed Central

Pooggin, Mikhail M.; Fütterer, Johannes; Hohn, Thomas

2008-01-01

Background Cauliflower mosaic virus (CaMV) and Rice tungro bacilliform virus (RTBV) belong to distinct genera of pararetroviruses infecting dicot and monocot plants, respectively. In both viruses, polycistronic translation of pregenomic (pg) RNA is initiated by shunting ribosomes that bypass a large region of the pgRNA leader with several short (s)ORFs and a stable stem-loop structure. The shunt requires translation of a 5′-proximal sORF terminating near the stem. In CaMV, mutations knocking out this sORF nearly abolish shunting and virus viability. Methodology/Principal Findings Here we show that two distant regions of the CaMV leader that form a minimal shunt configuration comprising the sORF, a bottom part of the stem, and a shunt landing sequence can be replaced by heterologous sequences that form a structurally similar configuration in RTBV without any dramatic effect on shunt-mediated translation and CaMV infectivity. The CaMV-RTBV chimeric leader sequence was largely stable over five viral passages in turnip plants: a few alterations that did eventually occur in the virus progenies are indicative of fine tuning of the chimeric sequence during adaptation to a new host. Conclusions/Significance Our findings demonstrate cross-species functionality of pararetroviral cis-elements driving ribosome shunting and evolutionary conservation of the shunt mechanism. We are grateful to Matthias Müller and Sandra Pauli for technical assistance. This work was initiated at Friedrich Miescher Institute (Basel, Switzerland). We thank Prof. Thomas Boller for hosting the group at the Institute of Botany. PMID:18286203

Characterization of a chimeric foot-and-mouth disease virus bearing bovine rhinitis B virus leader proteinase

USDA-ARS?s Scientific Manuscript database

Our recent study has shown that bovine rhinovirus type 2 (BRV2), a new member of the Aphthovirus genus, shares many motifs and sequence similarities with foot-and-mouth disease virus (FMDV). Despite low sequence conservation (36percent amino acid identity) and N- and C-terminus folding differences,...

Properties of the unusually short pulse sequences occurring prior to the first strokes of negative cloud-to-ground lightning flashes

NASA Astrophysics Data System (ADS)

Kolmasova, Ivana; Santolik, Ondrej; Farges, Thomas; Rison, William; Lan, Radek; Uhlir, Ludek

2014-05-01

We analyze pulse sequences occurring prior to first return strokes of negative cloud-to-ground lightning flashes. The magnetic-field waveforms are measured close to the thunderstorm using a broad-band analyzer with a sampling interval of 12.5 ns. The electric-field waveforms are measured at the distance of ~ 400 km using an analyzer with a sampling interval of 80 ns. The sequence is usually composed of three parts. It begins with a larger pulse train which is believed to be connected with initial breakdown processes. The train of preliminary breakdown pulses ("B" part) is followed by a relatively low and irregular pulse activity ("I" part), which is sometimes missing. The sequence ends with a pulse train attributed to the stepped leader ("L" part). We recognize two different patterns ("B-I-L" and "B-L" types) in recorded waveforms. For the first time, we analyze the time evolution of the pulse amplitudes in the "B" part of "B-I-L" type sequences. The pulse amplitude is decreasing on average by 34% of the maximum value within a given train. We observe an unusually short duration of sequences. This is probably linked to a low height of the thundercloud. Another possible explanation may be based on an untypical precipitation mix resulting in faster steeped leaders.

Expansion of ribosomally produced natural products: a nitrile hydratase- and Nif11-related precursor family

PubMed Central

2010-01-01

Background A new family of natural products has been described in which cysteine, serine and threonine from ribosomally-produced peptides are converted to thiazoles, oxazoles and methyloxazoles, respectively. These metabolites and their biosynthetic gene clusters are now referred to as thiazole/oxazole-modified microcins (TOMM). As exemplified by microcin B17 and streptolysin S, TOMM precursors contain an N-terminal leader sequence and C-terminal core peptide. The leader sequence contains binding sites for the posttranslational modifying enzymes which subsequently act upon the core peptide. TOMM peptides are small and highly variable, frequently missed by gene-finders and occasionally situated far from the thiazole/oxazole forming genes. Thus, locating a substrate for a particular TOMM pathway can be a challenging endeavor. Results Examination of candidate TOMM precursors has revealed a subclass with an uncharacteristically long leader sequence closely related to the enzyme nitrile hydratase. Members of this nitrile hydratase leader peptide (NHLP) family lack the metal-binding residues required for catalysis. Instead, NHLP sequences display the classic Gly-Gly cleavage motif and have C-terminal regions rich in heterocyclizable residues. The NHLP family exhibits a correlated species distribution and local clustering with an ABC transport system. This study also provides evidence that a separate family, annotated as Nif11 nitrogen-fixing proteins, can serve as natural product precursors (N11P), but not always of the TOMM variety. Indeed, a number of cyanobacterial genomes show extensive N11P paralogous expansion, such as Nostoc, Prochlorococcus and Cyanothece, which replace the TOMM cluster with lanthionine biosynthetic machinery. Conclusions This study has united numerous TOMM gene clusters with their cognate substrates. These results suggest that two large protein families, the nitrile hydratases and Nif11, have been retailored for secondary metabolism. Precursors for TOMMs and lanthionine-containing peptides derived from larger proteins to which other functions are attributed, may be widespread. The functions of these natural products have yet to be elucidated, but it is probable that some will display valuable industrial or medical activities. PMID:20500830

The tripartite leader sequence is required for ectopic expression of HAdV-B and HAdV-E E3 CR1 genes.

PubMed

Bair, Camden R; Kotha Lakshmi Narayan, Poornima; Kajon, Adriana E

2017-05-01

The unique repertoire of genes that characterizes the early region 3 (E3) of the different species of human adenovirus (HAdV) likely contributes to their distinct pathogenic traits. The function of many E3 CR1 proteins remains unknown possibly due to unidentified intrinsic properties that make them difficult to express ectopically. This study shows that the species HAdV-B- and HAdV-E-specific E3 CR1 genes can be expressed from vectors carrying the HAdV tripartite leader (TPL) sequence but not from traditional mammalian expression vectors. Insertion of the TPL sequence upstream of the HAdV-B and HAdV-E E3 CR1 open reading frames was sufficient to rescue protein expression from pCI-neo constructs in transfected 293T cells. The detection of higher levels of HAdV-B and HAdV-E E3 CR1 transcripts suggests that the TPL sequence may enhance gene expression at both the transcriptional and translational levels. Our findings will facilitate the characterization of additional AdV E3 proteins. Copyright © 2017 Elsevier Inc. All rights reserved.

T box riboswitches in Actinobacteria: Translational regulation via novel tRNA interactions

PubMed Central

Sherwood, Anna V.; Grundy, Frank J.; Henkin, Tina M.

2015-01-01

The T box riboswitch regulates many amino acid-related genes in Gram-positive bacteria. T box riboswitch-mediated gene regulation was shown previously to occur at the level of transcription attenuation via structural rearrangements in the 5′ untranslated (leader) region of the mRNA in response to binding of a specific uncharged tRNA. In this study, a novel group of isoleucyl-tRNA synthetase gene (ileS) T box leader sequences found in organisms of the phylum Actinobacteria was investigated. The Stem I domains of these RNAs lack several highly conserved elements that are essential for interaction with the tRNA ligand in other T box RNAs. Many of these RNAs were predicted to regulate gene expression at the level of translation initiation through tRNA-dependent stabilization of a helix that sequesters a sequence complementary to the Shine–Dalgarno (SD) sequence, thus freeing the SD sequence for ribosome binding and translation initiation. We demonstrated specific binding to the cognate tRNAIle and tRNAIle-dependent structural rearrangements consistent with regulation at the level of translation initiation, providing the first biochemical demonstration, to our knowledge, of translational regulation in a T box riboswitch. PMID:25583497

Characterization of an internal ribosomal entry segment within the 5' leader of avian reticuloendotheliosis virus type A RNA and development of novel MLV-REV-based retroviral vectors.

PubMed

López-Lastra, M; Gabus, C; Darlix, J L

1997-11-01

The murine leukemia virus (MLV)-related type C viruses constitute a major class of retroviruses that includes numerous endogenous and exogenous mammalian viruses and the related avian spleen necrosis virus (SNV). The MLV-related viruses possess a long and multifunctional 5' untranslated leader involved in key steps of the viral life cycle--splicing, translation, RNA dimerization, encapsidation, and reverse transcription. Recent studies have shown that the 5' leader of Friend murine leukemia virus and Moloney murine leukemia virus can direct cap independent translation of gag precursor proteins (Berlioz et al., 1995; Vagner et al., 1995b). These data, together with structural homology studies (Koning et al., 1992), prompted us to undertake a search for new internal ribosome entry segment (IRES) of retroviral origin. Here we describe an IRES element within the 5' leader of avian reticuloendotheliosis virus type A (REV-A) genomic RNA. Data show that the REV-A 5' IRES element maps downstream of the packaging/dimerization (E/DLS) sequence (Watanabe and Temin, 1982; Darlix et al., 1992) and the minimal IRES sequence appears to be within a 129 nt fragment (nucleotides 452-580) of the 5' leader, immediately upstream of the gag AUG codon. The REV-A IRES has been successfully utilized in the construction of novel high titer MLV-based retroviral vectors, containing one or more IRES elements of retroviral origin. These retroviral constructs, which represent a starting point for the design of novel vectors suitable for gene therapy, are also of interest as a model system of internal translation initiation and its possible regulation during development, cancer, or virus infection.

CsrA Participates in a PNPase Autoregulatory Mechanism by Selectively Repressing Translation of pnp Transcripts That Have Been Previously Processed by RNase III and PNPase

PubMed Central

Park, Hongmarn; Yakhnin, Helen; Connolly, Michael; Romeo, Tony

2015-01-01

ABSTRACT Csr is a conserved global regulatory system that represses or activates gene expression posttranscriptionally. CsrA of Escherichia coli is a homodimeric RNA binding protein that regulates transcription elongation, translation initiation, and mRNA stability by binding to the 5′ untranslated leader or initial coding sequence of target transcripts. pnp mRNA, encoding the 3′ to 5′ exoribonuclease polynucleotide phosphorylase (PNPase), was previously identified as a CsrA target by transcriptome sequencing (RNA-seq). Previous studies also showed that RNase III and PNPase participate in a pnp autoregulatory mechanism in which RNase III cleavage of the untranslated leader, followed by PNPase degradation of the resulting 5′ fragment, leads to pnp repression by an undefined translational repression mechanism. Here we demonstrate that CsrA binds to two sites in pnp leader RNA but only after the transcript is fully processed by RNase III and PNPase. In the absence of processing, both of the binding sites are sequestered in an RNA secondary structure, which prevents CsrA binding. The CsrA dimer bridges the upstream high-affinity site to the downstream site that overlaps the pnp Shine-Dalgarno sequence such that bound CsrA causes strong repression of pnp translation. CsrA-mediated translational repression also leads to a small increase in the pnp mRNA decay rate. Although CsrA has been shown to regulate translation and mRNA stability of numerous genes in a variety of organisms, this is the first example in which prior mRNA processing is required for CsrA-mediated regulation. IMPORTANCE CsrA protein represses translation of numerous mRNA targets, typically by binding to multiple sites in the untranslated leader region preceding the coding sequence. We found that CsrA represses translation of pnp by binding to two sites in the pnp leader transcript but only after it is processed by RNase III and PNPase. Processing by these two ribonucleases alters the mRNA secondary structure such that it becomes accessible to the ribosome for translation as well as to CsrA. As one of the CsrA binding sites overlaps the pnp ribosome binding site, bound CsrA prevents ribosome binding. This is the first example in which regulation by CsrA requires prior mRNA processing and should link pnp expression to conditions affecting CsrA activity. PMID:26438818

Dehydration-induced tps gene transcripts from an anhydrobiotic nematode contain novel spliced leaders and encode atypical GT-20 family proteins.

PubMed

Goyal, K; Browne, J A; Burnell, A M; Tunnacliffe, A

2005-06-01

Accumulation of the non-reducing disaccharide trehalose is associated with desiccation tolerance during anhydrobiosis in a number of invertebrates, but there is little information on trehalose biosynthetic genes in these organisms. We have identified two trehalose-6-phosphate synthase (tps) genes in the anhydrobiotic nematode Aphelenchus avenae and determined full length cDNA sequences for both; for comparison, full length tps cDNAs from the model nematode, Caenorhabditis elegans, have also been obtained. The A. avenae genes encode very similar proteins containing the catalytic domain characteristic of the GT-20 family of glycosyltransferases and are most similar to tps-2 of C. elegans; no evidence was found for a gene in A. avenae corresponding to Ce-tps-1. Analysis of A. avenae tps cDNAs revealed several features of interest, including alternative trans-splicing of spliced leader sequences in Aav-tps-1, and four different, novel SL1-related trans-spliced leaders, which were different to the canonical SL1 sequence found in all other nematodes studied. The latter observation suggests that A. avenae does not comply with the strict evolutionary conservation of SL1 sequences observed in other species. Unusual features were also noted in predicted nematode TPS proteins, which distinguish them from homologues in other higher eukaryotes (plants and insects) and in micro-organisms. Phylogenetic analysis confirmed their membership of the GT-20 glycosyltransferase family, but indicated an accelerated rate of molecular evolution. Furthermore, nematode TPS proteins possess N- and C-terminal domains, which are unrelated to those of other eukaryotes: nematode C-terminal domains, for example, do not contain trehalose-6-phosphate phosphatase-like sequences, as seen in plant and insect homologues. During onset of anhydrobiosis, both tps genes in A. avenae are upregulated, but exposure to cold or increased osmolarity also results in gene induction, although to a lesser extent. Trehalose seems likely therefore to play a role in a number of stress responses in nematodes.

Sequence and features of the tryptophan operon of Vibrio parahemolyticus.

PubMed

Crawford, I P; Han, C Y; Silverman, M

1991-01-01

The nucleotide sequence of the trp operon of the marine enteric bacterium Vibrio parahemolyticus is presented. The gene order E, G, D, C(F), B, A is identical to that of other enterics. The structural genes of the operon are preceded by a long leader region encoding a 41-residue peptide containing five tryptophan residues. The organization of the leader region suggests that transcription of the operon is subject to attenuation control. The promoter-operator region of the V. parahemolyticus trp operon is almost identical to the corresponding promoter-operator of E. coli. The similarities suggest that promoter strength and operator function are identical in the two species, and that transcription initiation is regulated by repression. The operon appears to lack the internal promoter within trpD that is common in terrestrial enteric species.

Enhanced functional expression of aquaporin Z via fusion of in situ cleavable leader peptides in Escherichia coli cell-free system.

PubMed

Zhang, Xu; Lian, Jiazhang; Kai, Lei; Huang, Lei; Cen, Peilin; Xu, Zhinan

2014-02-05

Aquaporin Z (AqpZ) is a water channel protein from Escherichia coli and has attracted many attentions to develop the biomimetic water filtration technology. Cell-free protein synthesis (CFPS) system, one of the most complex multi-enzymatic systems, has the ability of producing the integral membrane protein in vitro. To enhance the synthesis of AqpZ in E. coli cell-free system, several natural leader peptides were respectively fused at the N-terminus and were verified to enhance the expression level significantly. Moreover, the supplementation of detergents or liposome could activate leader peptidase from the cell-free extract and provide hydrophobic environment for proper folding of AqpZ. Thus, the release of mature AqpZ via the in situ removal of leader peptide was achieved, with a specific water transport activity of (2.1 ± 0.1) × 10⁻¹⁴ cm³ s⁻¹ monomer⁻¹. Using this in situ removable leader peptide strategy, the transcription-translation, leader sequence cleavage and membrane protein folding were integrated into a simple process in the cell-free system, providing a convenient approach to enhance the expression of target proteins, especially those membrane proteins difficult to achieve. Copyright © 2013 Elsevier Inc. All rights reserved.

Presence of a Shared 5'-Leader Sequence in Ancestral Human and Mammalian Retroviruses and Its Transduction into Feline Leukemia Virus.

PubMed

Kawasaki, Junna; Kawamura, Maki; Ohsato, Yoshiharu; Ito, Jumpei; Nishigaki, Kazuo

2017-10-15

Recombination events induce significant genetic changes, and this process can result in virus genetic diversity or in the generation of novel pathogenicity. We discovered a new recombinant feline leukemia virus (FeLV) gag gene harboring an unrelated insertion, termed the X region, which was derived from Felis catus endogenous gammaretrovirus 4 (FcERV-gamma4). The identified FcERV-gamma4 proviruses have lost their coding capabilities, but some can express their viral RNA in feline tissues. Although the X-region-carrying recombinant FeLVs appeared to be replication-defective viruses, they were detected in 6.4% of tested FeLV-infected cats. All isolated recombinant FeLV clones commonly incorporated a middle part of the FcERV-gamma4 5'-leader region as an X region. Surprisingly, a sequence corresponding to the portion contained in all X regions is also present in at least 13 endogenous retroviruses (ERVs) observed in the cat, human, primate, and pig genomes. We termed this shared genetic feature the commonly shared (CS) sequence. Despite our phylogenetic analysis indicating that all CS-sequence-carrying ERVs are classified as gammaretroviruses, no obvious closeness was revealed among these ERVs. However, the Shannon entropy in the CS sequence was lower than that in other parts of the provirus genome. Notably, the CS sequence of human endogenous retrovirus T had 73.8% similarity with that of FcERV-gamma4, and specific signals were detected in the human genome by Southern blot analysis using a probe for the FcERV-gamma4 CS sequence. Our results provide an interesting evolutionary history for CS-sequence circulation among several distinct ancestral viruses and a novel recombined virus over a prolonged period. IMPORTANCE Recombination among ERVs or modern viral genomes causes a rapid evolution of retroviruses, and this phenomenon can result in the serious situation of viral disease reemergence. We identified a novel recombinant FeLV gag gene that contains an unrelated sequence, termed the X region. This region originated from the 5' leader of FcERV-gamma4, a replication-incompetent feline ERV. Surprisingly, a sequence corresponding to the X region is also present in the 5' portion of other ERVs, including human endogenous retroviruses. Scattered copies of the ERVs carrying the unique genetic feature, here named the commonly shared (CS) sequence, were found in each host genome, suggesting that ancestral viruses may have captured and maintained the CS sequence. More recently, a novel recombinant FeLV hijacked the CS sequence from inactivated FcERV-gamma4 as the X region. Therefore, tracing the CS sequences can provide unique models for not only the modern reservoir of new recombinant viruses but also the genetic features shared among ancient retroviruses. Copyright © 2017 American Society for Microbiology.

The Effect of α-Mating Factor Secretion Signal Mutations on Recombinant Protein Expression in Pichia pastoris

PubMed Central

Lin-Cereghino, Geoff P.; Stark, Carolyn M.; Kim, Daniel; Chang, Jennifer; Shaheen, Nadia; Poerwanto, Hansel; Agari, Kimiko; Moua, Pachai; Low, Lauren K.; Tran, Namphuong; Huang, Amy D.; Nattestad, Maria; Oshiro, Kristin T.; Chang, John William; Chavan, Archana; Tsai, Jerry W.; Lin-Cereghino, Joan

2013-01-01

The methylotrophic yeast, Pichia pastoris, has been genetically engineered to produce many heterologous proteins for industrial and research purposes. In order to secrete proteins for easier purification from the extracellular medium, the coding sequence of recombinant proteins are initially fused to the Saccharomyces cerevisiae α-mating factor secretion signal leader. Extensive site-directed mutagenesis of the prepro region of the α-mating factor secretion signal sequence was performed in order to determine the effects of various deletions and substitutions on expression. Though some mutations clearly dampened protein expression, deletion of amino acids 57-70, corresponding to the predicted 3rd alpha helix of α-mating factor secretion signal, increased secretion of reporter proteins horseradish peroxidase and lipase at least 50% in small-scale cultures. These findings raise the possibility that the secretory efficiency of the leader can be further enhanced in the future. PMID:23454485

Translation of the mRNA of the maize transcriptional activator Opaque-2 is inhibited by upstream open reading frames present in the leader sequence.

PubMed Central

Lohmer, S; Maddaloni, M; Motto, M; Salamini, F; Thompson, R D

1993-01-01

The protein encoded by the Opaque-2 (O2) gene is a transcription factor, translated from an mRNA that possesses an unusually long 5' leader sequence containing three upstream open reading frames (uORFs). The efficiency of translation of O2 mRNA has been tested in vivo by a transient assay in which the level of activation of the b32 promoter, a natural target of O2 protein, is measured. We show that uORF-less O2 alleles possess a higher transactivation value than the wild-type allele and that the reduction in transactivation due to the uORFs is a cis-dominant effect. The data presented indicate that both uORF1 and uORF2 are involved in the reducing effect and suggest that both are likely to be translated. PMID:8439744

T box transcription antitermination riboswitch: Influence of nucleotide sequence and orientation on tRNA binding by the antiterminator element

PubMed Central

Fauzi, Hamid; Agyeman, Akwasi; Hines, Jennifer V.

2008-01-01

Many bacteria utilize riboswitch transcription regulation to monitor and appropriately respond to cellular levels of important metabolites or effector molecules. The T box transcription antitermination riboswitch responds to cognate uncharged tRNA by specifically stabilizing an antiterminator element in the 5′-untranslated mRNA leader region and precluding formation of a thermodynamically more stable terminator element. Stabilization occurs when the tRNA acceptor end base pairs with the first four nucleotides in the seven nucleotide bulge of the highly conserved antiterminator element. The significance of the conservation of the antiterminator bulge nucleotides that do not base pair with the tRNA is unknown, but they are required for optimal function. In vitro selection was used to determine if the isolated antiterminator bulge context alone dictates the mode in which the tRNA acceptor end binds the bulge nucleotides. No sequence conservation beyond complementarity was observed and the location was not constrained to the first four bases of the bulge. The results indicate that formation of a structure that recognizes the tRNA acceptor end in isolation is not the determinant driving force for the high phylogenetic sequence conservation observed within the antiterminator bulge. Additional factors or T box leader features more likely influenced the phylogenetic sequence conservation. PMID:19152843

Rhizobium meliloti anthranilate synthase gene: cloning, sequence, and expression in Escherichia coli.

PubMed Central

Bae, Y M; Holmgren, E; Crawford, I P

1989-01-01

We determined the DNA sequence of the Rhizobium meliloti gene encoding anthranilate synthase, the first enzyme of the tryptophan pathway. Sequences similar to those seen for the two subunits of the enzyme as found in all other procaryotic species studied are present in a single open reading frame of 729 codons. This apparent gene fusion joins the C terminus of the large subunit (TrpE) to the N terminus of the small subunit (TrpG) through a short connecting segment. We designate the fused gene trpE(G). The gene is flanked by a typical rho-independent terminator at the 3' end and a complex regulatory region at the 5' end resembling those of operons under transcriptional attenuation control. The location of the promoter was determined by S1 nuclease protection, using Rhizobium mRNA. Although this promoter was inactive in Escherichia coli, mutations eliciting activity were easily obtained. One of these was a C----T change at position -9 in the -10 region. The +1 position of the mRNA is the first base of the initiation codon of the leader peptide, implying that unlike trpE(G), which has a normal Shine-Dalgarno sequence, the leader peptide gene lacks a ribosome-binding site. Images PMID:2656657

1,4-Benzoquinone reductase from Phanerochaete chrysosporium: cDNA cloning and regulation of expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akileswaran, L.; Brock, B.J.; Cereghino, J.L.

1999-02-01

A cDNA clone encoding a quinone reductase (QR) from the white rot basidiomycete Phanerochaete chrysosporium was isolated and sequenced. The cDNA consisted of 1,007 nucleotides and a poly(A) tail and encoded a deduced protein containing 271 amino acids. The experimentally determined eight-amino-acid N-germinal sequence of the purified QR protein from P. chrysosporium matched amino acids 72 to 79 of the predicted translation product of the cDNA. The M{sub r} of the predicted translation product, beginning with Pro-72, was essentially identical to the experimentally determined M{sub r} of one monomer of the QR dimer, and this finding suggested that QR ismore » synthesized as a proenzyme. The results of in vitro transcription-translation experiments suggested that QR is synthesized as a proenzyme with a 71-amino-acid leader sequence. This leader sequence contains two potential KEX2 cleavage sites and numerous potential cleavage sites for dipeptidyl aminopeptidase. The QR activity in cultures of P. chrysosporium increased following the addition of 2-dimethoxybenzoquinone, vanillic acid, or several other aromatic compounds. An immunoblot analysis indicated that induction resulted in an increase in the amount of QR protein, and a Northern blot analysis indicated that this regulation occurs at the level of the qr mRNA.« less

Characterization of vertical electric fields 500 m and 30 m from triggered lightning

NASA Astrophysics Data System (ADS)

Rubenstein, M.; Rachidi, F.; Uman, M. A.; Thottappillil, R.; Rakov, V. A.; Nucci, C. A.

1995-05-01

Vertical electric field waveforms of leader-return stroke sequences measured 500 m and 30 m from rocket-triggered lightning are presented. The 500-m data were recorded during the summer of 1986, the 30-m data during the summer of 1991, both at the NASA Kennedy Space Center, Florida. The 40 leader-return stroke field waveforms at 500 m and the 8 waveforms at 30 m all appear as asymmetrical V-shaped pulses, the bottom of the V being associated with the transition from the leader to the return stroke. Only two waveforms at 30 m were suitable for quantitative analysis. The widths of the V at half of peak value for these are 1.8 and 5.0 μs, while for the 500-m data they are 1 to 2 orders of magnitude greater, with a median value of 100 μs. Applying a widely used and simple leader model to the measured leader electric fields at 500 m, we infer, for the bottom kilometer or so of the leader channel, leader speeds between 2×106 and 2×107 m/s and leader charges per unit length of 0.02×10-3 to 0.08×10-3 C/m. From the two measured leader electric field changes at 30 m we infer, using the same leader model, for the bottom 100 meters or so of the leader channel, speeds of 3×107 and 1×107 m/s (the corresponding measured waveform half widths are 1.8 μs and 5.0 μs) and charges per unit length of 0.14×10-3 and 0.02×10-3 C/m (the corresponding measured leader field changes are 81 kV/m and 12 kV/m). The corresponding measured return stroke peak currents for the above two cases are 40 kA and 7 kA, respectively. A positive correlation is observed between the magnitude of the leader field change at 500 m and the ensuing return stroke current peak.

Molecular identification and characterization of clustered regularly interspaced short palindromic repeat (CRISPR) gene cluster in Taylorella equigenitalis.

PubMed

Hara, Yasushi; Hayashi, Kyohei; Nakajima, Takuya; Kagawa, Shizuko; Tazumi, Akihiro; Moore, John E; Matsuda, Motoo

2013-09-01

Clustered regularly interspaced short palindromic repeats (CRISPRs), of approximately 10,000 base pairs (bp) in length, were shown to occur in the Japanese Taylorella equigenitalis strain, EQ59. The locus was composed of the putative CRISPRs-associated with 5 (cas5), RAMP csd1, csd2, recB, cas1, a leader region, 13 CRISPR consensus sequence repeats (each 32 bp; 5'-TCAGCCACGTTCGCGTGGCTGTGTGTTTAAAG-3'). These were in turn separated by 12 non repetitive unique spacer regions of similar length. In addition, a leader region, a transposase/IS protein, a leader region, and cas3 were also seen. All seven putative open reading frames carry their ribosome binding sites. Promoter consensus sequences at the -35 and -10 regions and putative intrinsic ρ-independent transcription terminator regions also occurred. A possible long overlap of 170 bp in length occurred between the recB and cas1 loci. Positive reverse transcription PCR signals of cas5, RAMP csd1, csd2-recB/cas1, and cas3 were generated. A putative secondary structure of the CRISPR consensus repeats was constructed. Following this, CRISPR results of the T. equigenitalis EQ59 isolate were subsequently compared with those from the Taylorella asinigenitalis MCE3 isolate.

The spliced leader RNA gene array in phloem-restricted plant trypanosomatids (Phytomonas) partitions into two major groupings: epidemiological implications.

PubMed

Dollet, M; Sturm, N R; Campbell, D A

2001-03-01

The arbitrary genus Phytomonas includes a biologically diverse group of kinetoplastids that live in a wide variety of plant environments. To understand better the subdivisions within the phytomonads and the variability within groups, the exon, intron and non-transcribed spacer sequences of the spliced leader RNA gene were compared among isolates of the phloem-restricted members. A total of 29 isolates associated with disease in coconut, oil palm and red ginger (Alpinia purpurata, Zingibreaceae) were examined, all originating from plantations in South America and the Caribbean over a 12-year period. Analysis of non-transcribed spacer sequences revealed 2 main groups, I and II; group II could be further subdivided into 2 subgroups, IIa and Ilb. Three classes of spliced leader (SL) RNA gene were seen, with SLI corresponding to group I, SLIIa to group lIa, and SLIIb to group IIb. Two isolates showed some characteristics of both major groups. Group-specific oligonucleotide probes for hybridization studies were tested, and a multiplex amplification scheme was devised to allow direct differentiation between the 2 major groups of phloem-restricted Phytomonas. These results provide tools for diagnostic and molecular epidemiology of plant trypanosomes that are pathogenic for commercially important flowers and palms.

A unified engineering model of the first stroke in downward negative lightning

NASA Astrophysics Data System (ADS)

Nag, Amitabh; Rakov, Vladimir A.

2016-03-01

Each stroke in a negative cloud-to-ground lightning flash is composed of downward leader and upward return stroke processes, which are usually modeled individually. The first stroke leader is stepped and starts with preliminary breakdown (PB) which is often viewed as a separate process. We present the first unified engineering model for computing the electric field produced by a sequence of PB, stepped leader, and return stroke processes, serving to transport negative charge to ground. We assume that a negatively charged channel extends downward in a stepped fashion during both the PB and leader stages. Each step involves a current wave that propagates upward along the newly formed channel section. Once the leader attaches to ground, an upward propagating return stroke neutralizes the charge deposited along the channel. Model-predicted electric fields are in reasonably good agreement with simultaneous measurements at both near (hundreds of meters, electrostatic field component is dominant) and far (tens of kilometers, radiation field component is dominant) distances from the lightning channel. Relations between the features of computed electric field waveforms and model input parameters are examined. It appears that peak currents associated with PB pulses are similar to return stroke peak currents, and the observed variation of electric radiation field peaks produced by leader steps at different heights above ground is influenced by the ground corona space charge.

Spliced leader RNA of trypanosomes: in vivo mutational analysis reveals extensive and distinct requirements for trans splicing and cap4 formation.

PubMed Central

Lücke, S; Xu, G L; Palfi, Z; Cross, M; Bellofatto, V; Bindereif, A

1996-01-01

In trypanosomes mRNAs are generated through trans splicing. The spliced leader (SL) RNA, which donates the 5'-terminal mini-exon to each of the protein coding exons, plays a central role in the trans splicing process. We have established in vivo assays to study in detail trans splicing, cap4 modification, and RNP assembly of the SL RNA in the trypanosomatid species Leptomonas seymouri. First, we found that extensive sequences within the mini-exon are required for SL RNA function in vivo, although a conserved length of 39 nt is not essential. In contrast, the intron sequence appears to be surprisingly tolerant to mutation; only the stem-loop II structure is indispensable. The asymmetry of the sequence requirements in the stem I region suggests that this domain may exist in different functional conformations. Second, distinct mini-exon sequences outside the modification site are important for efficient cap4 formation. Third, all SL RNA mutations tested allowed core RNP assembly, suggesting flexible requirements for core protein binding. In sum, the results of our mutational analysis provide evidence for a discrete domain structure of the SL RNA and help to explain the strong phylogenetic conservation of the mini-exon sequence and of the overall SL RNA secondary structure; they also suggest that there may be certain differences between trans splicing in nematodes and trypanosomes. This approach provides a basis for studying RNA-RNA interactions in the trans spliceosome. Images PMID:8861965

Codon-Anticodon Recognition in the Bacillus subtilis glyQS T Box Riboswitch

PubMed Central

Caserta, Enrico; Liu, Liang-Chun; Grundy, Frank J.; Henkin, Tina M.

2015-01-01

Many amino acid-related genes in Gram-positive bacteria are regulated by the T box riboswitch. The leader RNA of genes in the T box family controls the expression of downstream genes by monitoring the aminoacylation status of the cognate tRNA. Previous studies identified a three-nucleotide codon, termed the “Specifier Sequence,” in the riboswitch that corresponds to the amino acid identity of the downstream genes. Pairing of the Specifier Sequence with the anticodon of the cognate tRNA is the primary determinant of specific tRNA recognition. This interaction mimics codon-anticodon pairing in translation but occurs in the absence of the ribosome. The goal of the current study was to determine the effect of a full range of mismatches for comparison with codon recognition in translation. Mutations were individually introduced into the Specifier Sequence of the glyQS leader RNA and tRNAGly anticodon to test the effect of all possible pairing combinations on tRNA binding affinity and antitermination efficiency. The functional role of the conserved purine 3′ of the Specifier Sequence was also verifiedin this study. We found that substitutions at the Specifier Sequence resulted in reduced binding, the magnitude of which correlates well with the predicted stability of the RNA-RNA pairing. However, the tolerance for specific mismatches in antitermination was generally different from that during decoding, which reveals a unique tRNA recognition pattern in the T box antitermination system. PMID:26229106

An intergenic non-coding rRNA correlated with expression of the rRNA and frequency of an rRNA single nucleotide polymorphism in lung cancer cells.

PubMed

Shiao, Yih-Horng; Lupascu, Sorin T; Gu, Yuhan D; Kasprzak, Wojciech; Hwang, Christopher J; Fields, Janet R; Leighty, Robert M; Quiñones, Octavio; Shapiro, Bruce A; Alvord, W Gregory; Anderson, Lucy M

2009-10-19

Ribosomal RNA (rRNA) is a central regulator of cell growth and may control cancer development. A cis noncoding rRNA (nc-rRNA) upstream from the 45S rRNA transcription start site has recently been implicated in control of rRNA transcription in mouse fibroblasts. We investigated whether a similar nc-rRNA might be expressed in human cancer epithelial cells, and related to any genomic characteristics. Using quantitative rRNA measurement, we demonstrated that a nc-rRNA is transcribed in human lung epithelial and lung cancer cells, starting from approximately -1000 nucleotides upstream of the rRNA transcription start site (+1) and extending at least to +203. This nc-rRNA was significantly more abundant in the majority of lung cancer cell lines, relative to a nontransformed lung epithelial cell line. Its abundance correlated negatively with total 45S rRNA in 12 of 13 cell lines (P = 0.014). During sequence analysis from -388 to +306, we observed diverse, frequent intercopy single nucleotide polymorphisms (SNPs) in rRNA, with a frequency greater than predicted by chance at 12 sites. A SNP at +139 (U/C) in the 5' leader sequence varied among the cell lines and correlated negatively with level of the nc-rRNA (P = 0.014). Modelling of the secondary structure of the rRNA 5'-leader sequence indicated a small increase in structural stability due to the +139 U/C SNP and a minor shift in local configuration occurrences. The results demonstrate occurrence of a sense nc-rRNA in human lung epithelial and cancer cells, and imply a role in regulation of the rRNA gene, which may be affected by a +139 SNP in the 5' leader sequence of the primary rRNA transcript.

5’-Terminal AUGs in Escherichia coli mRNAs with Shine-Dalgarno Sequences: Identification and Analysis of Their Roles in Non-Canonical Translation Initiation

PubMed Central

Beck, Heather J.; Fleming, Ian M. C.

2016-01-01

Analysis of the Escherichia coli transcriptome identified a unique subset of messenger RNAs (mRNAs) that contain a conventional untranslated leader and Shine-Dalgarno (SD) sequence upstream of the gene’s start codon while also containing an AUG triplet at the mRNA’s 5’- terminus (5’-uAUG). Fusion of the coding sequence specified by the 5’-terminal putative AUG start codon to a lacZ reporter gene, as well as primer extension inhibition assays, reveal that the majority of the 5’-terminal upstream open reading frames (5’-uORFs) tested support some level of lacZ translation, indicating that these mRNAs can function both as leaderless and canonical SD-leadered mRNAs. Although some of the uORFs were expressed at low levels, others were expressed at levels close to that of the respective downstream genes and as high as the naturally leaderless cI mRNA of bacteriophage λ. These 5’-terminal uORFs potentially encode peptides of varying lengths, but their functions, if any, are unknown. In an effort to determine whether expression from the 5’-terminal uORFs impact expression of the immediately downstream cistron, we examined expression from the downstream coding sequence after mutations were introduced that inhibit efficient 5’-uORF translation. These mutations were found to affect expression from the downstream cistrons to varying degrees, suggesting that some 5’-uORFs may play roles in downstream regulation. Since the 5’-uAUGs found on these conventionally leadered mRNAs can function to bind ribosomes and initiate translation, this indicates that canonical mRNAs containing 5’-uAUGs should be examined for their potential to function also as leaderless mRNAs. PMID:27467758

Three-Dimensional Reconstruction of Cloud-to-Ground Lightning Using High-Speed Video and VHF Broadband Interferometer

NASA Astrophysics Data System (ADS)

Li, Yun; Qiu, Shi; Shi, Lihua; Huang, Zhengyu; Wang, Tao; Duan, Yantao

2017-12-01

The time resolved three-dimensional (3-D) spatial reconstruction of lightning channels using high-speed video (HSV) images and VHF broadband interferometer (BITF) data is first presented in this paper. Because VHF and optical radiations in step formation process occur with time separation no more than 1 μs, the observation data of BITF and HSV at two different sites provide the possibility of reconstructing the time resolved 3-D channel of lightning. With the proposed procedures for 3-D reconstruction of leader channels, dart leaders as well as stepped leaders with complex multiple branches can be well reconstructed. The differences between 2-D speeds and 3-D speeds of leader channels are analyzed by comparing the development of leader channels in 2-D and 3-D space. Since return stroke (RS) usually follows the path of previous leader channels, the 3-D speeds of the return strokes are first estimated by combination with the 3-D structure of the preceding leaders and HSV image sequences. For the fourth RS, the ratios of the 3-D to 2-D RS speeds increase with height, and the largest ratio of the 3-D to 2-D return stroke speeds can reach 2.03, which is larger than the result of triggered lightning reported by Idone. Since BITF can detect lightning radiation in a 360° view, correlated BITF and HSV observations increase the 3-D detection probability than dual-station HSV observations, which is helpful to obtain more events and deeper understanding of the lightning process.

Mutagenesis of NosM Leader Peptide Reveals Important Elements in Nosiheptide Biosynthesis

PubMed Central

Jin, Liang; Wu, Xuri; Xue, Yanjiu; Jin, Yue; Wang, Shuzhen

2016-01-01

ABSTRACT Nosiheptide, a typical member of the ribosomally synthesized and posttranslationally modified peptides (RiPPs), exhibits potent activity against multidrug-resistant Gram-positive bacterial pathogens. The precursor peptide of nosiheptide (NosM) is comprised of a leader peptide with 37 amino acids and a core peptide containing 13 amino acids. To pinpoint elements in the leader peptide that are essential for nosiheptide biosynthesis, a collection of mutants with unique sequence features, including N- and C-terminal motifs, peptide length, and specific sites in the leader peptide, was generated by mutagenesis in vivo. The effects of various mutants on nosiheptide biosynthesis were evaluated. In addition to the necessity of a conserved motif LEIS box, native length and the N-terminal 12 amino acid residues were indispensable, and single-site substitutions of these 12 amino acid residues resulted in changes ranging from a greater-than-5-fold decrease to a 2-fold increase of nosiheptide production, depending on the sites and substituted residues. Moreover, although the C-terminal motif is not conservative, significant effects of this portion on nosiheptide production were also evident. Taken together, the present results further highlight the importance of the leader peptide in nosiheptide biosynthesis, and provide new insights into the diversity and specificity of leader peptides in the biosynthesis of various RiPPs. IMPORTANCE As a representative thiopeptide, nosiheptide exhibits excellent antibacterial activity. Although the biosynthetic gene cluster and several modification steps have been revealed, the presence and roles of the leader peptide within the precursor peptide of the nosiheptide gene cluster remain elusive. Thus, identification of specific elements in the leader peptide can significantly facilitate the genetic manipulation of the gene cluster for increasing nosiheptide production or generating diverse analogues. Given the complexity of the biosynthetic process, the instability of the leader peptide, and the unavailability of intermediates, cocrystallization of intermediates, leader peptide, and modification enzymes is currently not feasible. Therefore, a mutagenesis approach was used to construct a series of leader peptide mutants to uncover a number of crucial and characteristic elements affecting nosiheptide biosynthesis, which moves a considerable distance toward a thorough understanding of the biosynthetic machinery for thiopeptides. PMID:27913416

Negative effect of the 5'-untranslated leader sequence on Ac transposon promoter expression.

PubMed

Scortecci, K C; Raina, R; Fedoroff, N V; Van Sluys, M A

1999-08-01

Transposable elements are used in heterologous plant hosts to clone genes by insertional mutagenesis. The Activator (Ac) transposable element has been cloned from maize, and introduced into a variety of plants. However, differences in regulation and transposition frequency have been observed between different host plants. The cause of this variability is still unknown. To better understand the activity of the Ac element, we analyzed the Ac promoter region and its 5'-untranslated leader sequence (5' UTL). Transient assays in tobacco NT1 suspension cells showed that the Ac promoter is a weak promoter and its activity was localized by deletion analyses. The data presented here indicate that the core of the Ac promoter is contained within 153 bp fragment upstream to transcription start sites. An important inhibitory effect (80%) due to the presence of the 5' UTL was found on the expression of LUC reporter gene. Here we demonstrate that the presence of the 5' UTL in the constructs reduces the expression driven by either strong or weak promoters.

[Comparative genomics and evolutionary analysis of CRISPR loci in acetic acid bacteria].

PubMed

Xia, Kai; Liang, Xin-le; Li, Yu-dong

2015-12-01

The clustered regularly interspaced short palindromic repeat (CRISPR) is a widespread adaptive immunity system that exists in most archaea and many bacteria against foreign DNA, such as phages, viruses and plasmids. In general, CRISPR system consists of direct repeat, leader, spacer and CRISPR-associated sequences. Acetic acid bacteria (AAB) play an important role in industrial fermentation of vinegar and bioelectrochemistry. To investigate the polymorphism and evolution pattern of CRISPR loci in acetic acid bacteria, bioinformatic analyses were performed on 48 species from three main genera (Acetobacter, Gluconacetobacter and Gluconobacter) with whole genome sequences available from the NCBI database. The results showed that the CRISPR system existed in 32 species of the 48 strains studied. Most of the CRISPR-Cas system in AAB belonged to type I CRISPR-Cas system (subtype E and C), but type II CRISPR-Cas system which contain cas9 gene was only found in the genus Acetobacter and Gluconacetobacter. The repeat sequences of some CRISPR were highly conserved among species from different genera, and the leader sequences of some CRISPR possessed conservative motif, which was associated with regulated promoters. Moreover, phylogenetic analysis of cas1 demonstrated that they were suitable for classification of species. The conservation of cas1 genes was associated with that of repeat sequences among different strains, suggesting they were subjected to similar functional constraints. Moreover, the number of spacer was positively correlated with the number of prophages and insertion sequences, indicating the acetic acid bacteria were continually invaded by new foreign DNA. The comparative analysis of CRISR loci in acetic acid bacteria provided the basis for investigating the molecular mechanism of different acetic acid tolerance and genome stability in acetic acid bacteria.

Prototype foamy virus envelope glycoprotein leader peptide processing is mediated by a furin-like cellular protease, but cleavage is not essential for viral infectivity.

PubMed

Duda, Anja; Stange, Annett; Lüftenegger, Daniel; Stanke, Nicole; Westphal, Dana; Pietschmann, Thomas; Eastman, Scott W; Linial, Maxine L; Rethwilm, Axel; Lindemann, Dirk

2004-12-01

Analogous to cellular glycoproteins, viral envelope proteins contain N-terminal signal sequences responsible for targeting them to the secretory pathway. The prototype foamy virus (PFV) envelope (Env) shows a highly unusual biosynthesis. Its precursor protein has a type III membrane topology with both the N and C terminus located in the cytoplasm. Coexpression of FV glycoprotein and interaction of its leader peptide (LP) with the viral capsid is essential for viral particle budding and egress. Processing of PFV Env into the particle-associated LP, surface (SU), and transmembrane (TM) subunits occur posttranslationally during transport to the cell surface by yet-unidentified cellular proteases. Here we provide strong evidence that furin itself or a furin-like protease and not the signal peptidase complex is responsible for both processing events. N-terminal protein sequencing of the SU and TM subunits of purified PFV Env-immunoglobulin G immunoadhesin identified furin consensus sequences upstream of both cleavage sites. Mutagenesis analysis of two overlapping furin consensus sequences at the PFV LP/SU cleavage site in the wild-type protein confirmed the sequencing data and demonstrated utilization of only the first site. Fully processed SU was almost completely absent in viral particles of mutants having conserved arginine residues replaced by alanines in the first furin consensus sequence, but normal processing was observed upon mutation of the second motif. Although these mutants displayed a significant loss in infectivity as a result of reduced particle release, no correlation to processing inhibition was observed, since another mutant having normal LP/SU processing had a similar defect.

Trypanosomatidae: Phytomonas detection in plants and phytophagous insects by PCR amplification of a genus-specific sequence of the spliced leader gene.

PubMed

Serrano, M G; Nunes, L R; Campaner, M; Buck, G A; Camargo, E P; Teixeira, M M

1999-03-01

In this paper we describe a method for the detection of Phytomonas spp. from plants and phytophagous insects using the PCR technique by targeting a genus-specific sequence of the spliced leader (SL) gene. PCR amplification of DNA from 48 plant and insect isolates previously classified as Phytomonas by morphological, biochemical, and molecular criteria resulted in all cases in a 100-bp fragment that hybridized with the Phytomonas-specific spliced leader-derived probe SL3'. Moreover, this Phytomonas-specific PCR could also detect Phytomonas spp. in crude preparations of naturally infected plants and insects. This method shows no reaction with any other trypanosomatid genera or with plant and insect host DNA, revealing it to be able to detect Phytomonas spp. from fruit, latex, or phloem of various host plants as well as from salivary glands and digestive tubes of several species of insect hosts. Results demonstrated that SLPCR is a simple, fast, specific, and sensitive method that can be applied to the diagnosis of Phytomonas among cultured trypanosomatids and directly in plants and putative vector insects. Therefore, the method was shown to be a very specific and sensitive tool for diagnosis of Phytomonas without the need for isolation, culture, and DNA extraction of flagellates, a feature that is very convenient for practical and epidemiological purposes. Copyright 1999 Academic Press.

Factors affecting expression of the recF gene of Escherichia coli K-12.

PubMed

Sandler, S J; Clark, A J

1990-01-31

This report describes four factors which affect expression of the recF gene from strong upstream lambda promoters under temperature-sensitive cIAt2-encoded repressor control. The first factor was the long mRNA leader sequence consisting of the Escherichia coli dnaN gene and 95% of the dnaA gene and lambda bet, N (double amber) and 40% of the exo gene. When most of this DNA was deleted, RecF became detectable in maxicells. The second factor was the vector, pBEU28, a runaway replication plasmid. When we substituted pUC118 for pBEU28, RecF became detectable in whole cells by the Coomassie blue staining technique. The third factor was the efficiency of initiation of translation. We used site-directed mutagenesis to change the mRNA leader, ribosome-binding site and the 3 bp before and after the translational start codon. Monitoring the effect of these mutational changes by translational fusion to lacZ, we discovered that the efficiency of initiation of translation was increased 30-fold. Only an estimated two- or threefold increase in accumulated levels of RecF occurred, however. This led us to discover the fourth factor, namely sequences in the recF gene itself. These sequences reduce expression of the recF-lacZ fusion genes 100-fold. The sequences responsible for this decrease in expression occur in four regions in the N-terminal half of recF. Expression is reduced by some sequences at the transcriptional level and by others at the translational level.

Confronting Myths about Teacher Leadership

ERIC Educational Resources Information Center

Sinha, Somnath; Hanuscin, Deborah; Rebello, Carina; Muslu, Nilay; Cheng, Ya-Wen

2012-01-01

"Leadership in Freshman Physics" is an NSF-funded professional development program designed to support 9th grade teacher leaders in the successful implementation of a "Physics First" or curriculum sequence that places physics prior to biology and chemistry. Leadership is viewed as an essential component in the initial success…

Biosynthesis of the Polycyclic Antimicrobial Peptides Lacticin 481, Haloduracin, and Cinnamycin

ERIC Educational Resources Information Center

Cooper, Lisa E.

2009-01-01

Lantibiotics are bacterial-derived polycyclic antimicrobial peptides. They are genetically encoded and ribosomally synthesized as precursor peptides containing a structural region that undergoes post-translational modification and a leader sequence that is not modified. Specific serine and threonine residues in the pre-lantibiotic structural…

Evaluation of leader peptides that affect the secretory ability of a multiple bacteriocin transporter, EnkT.

PubMed

Sushida, Hirotoshi; Ishibashi, Naoki; Zendo, Takeshi; Wilaipun, Pongtep; Leelawatcharamas, Vichien; Nakayama, Jiro; Sonomoto, Kenji

2018-02-13

EnkT is a novel ATP-binding cassette (ABC) transporter responsible for secretion of four bacteriocins, enterocins NKR-5-3A, C, D, and Z (Ent53A, C, D, and Z), produced by Enterococcus faecium NKR-5-3. It is generally recognized that the secretion of a bacteriocin requires a dedicated ABC transporter, although molecular mechanisms of this secretion are yet to be revealed. In order to characterize the unique ability of EnkT to secrete multiple bacteriocins, the role of N-terminal leader peptides of bacteriocin precursors was evaluated using Ent53C precursor as a model. The 18-amino acid leader peptide of Ent53C (Lc) was modified by site-directed mutagenesis to generate various point mutations, truncations, or extensions, and substitutions with other leader peptides. The impact of these Lc mutations on Ent53C secretion was evaluated using a quantitative antimicrobial activity assay. We observed that Ent53C production increased with Ala substitution of the highly conserved C-terminal double glycine residues that are recognized as the cleavage site. In contrast, Ent53C antimicrobial activity decreased, with decrease in the length of the putative α-helix-forming region of Lc. Furthermore, EnkT recognized and transported Ent53C of the transformants possessing heterologous leader peptides of enterocin A, pediocin PA-1, brochocins A and B, and lactococcins Qα and Qβ. These results indicated that EnkT shows significant tolerance towards the sequence and length of leader peptides, to secrete multiple bacteriocins. This further demonstrates the functional diversity of bacteriocin ABC transporters and the importance of leader peptides as their recognition motif. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Investigation of the Solubility and Enzymatic Activity of a Thioredoxin-Gelonin Fusion Protein

DTIC Science & Technology

1997-05-01

1992). Figure lb is a diagram based on nuclear magnetic resonance data (NMR) of a 29-nucleotide RNA sequence containing the 17-nucleotide S/R loop and...Battalion Chemical Officer, Nuclear , Biological, Chancl Recoassanm Platoon Leader, Chemical Company Executive Officer, US Army Chemical Officer Advanced

Learning to Teach: Practice-Based Preparation in Teacher Education. Special Issues Brief

ERIC Educational Resources Information Center

Benedict, Amber; Holdheide, Lynn; Brownell, Mary; Foley, Abigail Marshall

2016-01-01

This Special Issues Brief from the Collaboration for Effective Educator Development, Accountability and Reform (CEEDAR Center) and the Center on Great Teachers and Leaders (GTL Center) outlines essential features for providing high-quality, structured, and sequenced opportunities to practice within teacher preparation programs. This brief is…

Genomic sequence of mandarin fish rhabdovirus with an unusual small non-transcriptional ORF.

PubMed

Tao, Jian-Jun; Zhou, Guang-Zhou; Gui, Jian-Fang; Zhang, Qi-Ya

2008-03-01

The complete genome of mandarin fish Siniperca chuatsi rhabdovirus (SCRV) was cloned and sequenced. It comprises 11,545 nucleotides and contains five genes encoding the nucleoprotein N, the phosphoprotein P, the matrix protein M, the glycoprotein G, and the RNA-dependent RNA polymerase protein L. At the 3' and 5' termini of SCRV genome, leader and trailer sequences show inverse complementarity. The N, P, M and G proteins share the highest sequence identities (ranging from 14.8 to 41.5%) with the respective proteins of rhabdovirus 903/87, the L protein has the highest identity with those of vesiculoviruses, especially with Chandipura virus (44.7%). Phylogenetic analysis of L proteins showed that SCRV clustered with spring vireamia of carp virus (SVCV) and was most closely related to viruses in the genus Vesiculovirus. In addition, an overlapping open reading frame (ORF) predicted to encode a protein similar to vesicular stomatitis virus C protein is present within the P gene of SCRV. Furthermore, an unoverlapping small ORF downstream of M ORF within M gene is predicted (tentatively called orf4). Therefore, the genomic organization of SCRV can be proposed as 3' leader-N-P/C-M-(orf4)-G-L-trailer 5'. Orf4 transcription or translation products could not be detected by northern or Western blot, respectively, though one similar mRNA band to M mRNA was found. This is the first report on one small unoverlapping ORF in M gene of a fish rhabdovirus.

Polymorphism in Human Cytomegalovirus UL40 Impacts on Recognition of Human Leukocyte Antigen-E (HLA-E) by Natural Killer Cells*

PubMed Central

Heatley, Susan L.; Pietra, Gabriella; Lin, Jie; Widjaja, Jacqueline M. L.; Harpur, Christopher M.; Lester, Sue; Rossjohn, Jamie; Szer, Jeff; Schwarer, Anthony; Bradstock, Kenneth; Bardy, Peter G.; Mingari, Maria Cristina; Moretta, Lorenzo; Sullivan, Lucy C.; Brooks, Andrew G.

2013-01-01

Natural killer (NK) cell recognition of the nonclassical human leukocyte antigen (HLA) molecule HLA-E is dependent on the presentation of a nonamer peptide derived from the leader sequence of other HLA molecules to CD94-NKG2 receptors. However, human cytomegalovirus can manipulate this central innate interaction through the provision of a “mimic” of the HLA-encoded peptide derived from the immunomodulatory glycoprotein UL40. Here, we analyzed UL40 sequences isolated from 32 hematopoietic stem cell transplantation recipients experiencing cytomegalovirus reactivation. The UL40 protein showed a “polymorphic hot spot” within the region that encodes the HLA leader sequence mimic. Although all sequences that were identical to those encoded within HLA-I genes permitted the interaction between HLA-E and CD94-NKG2 receptors, other UL40 polymorphisms reduced the affinity of the interaction between HLA-E and CD94-NKG2 receptors. Furthermore, functional studies using NK cell clones expressing either the inhibitory receptor CD94-NKG2A or the activating receptor CD94-NKG2C identified UL40-encoded peptides that were capable of inhibiting target cell lysis via interaction with CD94-NKG2A, yet had little capacity to activate NK cells through CD94-NKG2C. The data suggest that UL40 polymorphisms may aid evasion of NK cell immunosurveillance by modulating the affinity of the interaction with CD94-NKG2 receptors. PMID:23335510

Polymorphism in human cytomegalovirus UL40 impacts on recognition of human leukocyte antigen-E (HLA-E) by natural killer cells.

PubMed

Heatley, Susan L; Pietra, Gabriella; Lin, Jie; Widjaja, Jacqueline M L; Harpur, Christopher M; Lester, Sue; Rossjohn, Jamie; Szer, Jeff; Schwarer, Anthony; Bradstock, Kenneth; Bardy, Peter G; Mingari, Maria Cristina; Moretta, Lorenzo; Sullivan, Lucy C; Brooks, Andrew G

2013-03-22

Natural killer (NK) cell recognition of the nonclassical human leukocyte antigen (HLA) molecule HLA-E is dependent on the presentation of a nonamer peptide derived from the leader sequence of other HLA molecules to CD94-NKG2 receptors. However, human cytomegalovirus can manipulate this central innate interaction through the provision of a "mimic" of the HLA-encoded peptide derived from the immunomodulatory glycoprotein UL40. Here, we analyzed UL40 sequences isolated from 32 hematopoietic stem cell transplantation recipients experiencing cytomegalovirus reactivation. The UL40 protein showed a "polymorphic hot spot" within the region that encodes the HLA leader sequence mimic. Although all sequences that were identical to those encoded within HLA-I genes permitted the interaction between HLA-E and CD94-NKG2 receptors, other UL40 polymorphisms reduced the affinity of the interaction between HLA-E and CD94-NKG2 receptors. Furthermore, functional studies using NK cell clones expressing either the inhibitory receptor CD94-NKG2A or the activating receptor CD94-NKG2C identified UL40-encoded peptides that were capable of inhibiting target cell lysis via interaction with CD94-NKG2A, yet had little capacity to activate NK cells through CD94-NKG2C. The data suggest that UL40 polymorphisms may aid evasion of NK cell immunosurveillance by modulating the affinity of the interaction with CD94-NKG2 receptors.

Characterization of shark complement factor I gene(s): genomic analysis of a novel shark-specific sequence.

PubMed

Shin, Dong-Ho; Webb, Barbara M; Nakao, Miki; Smith, Sylvia L

2009-07-01

Complement factor I is a crucial regulator of mammalian complement activity. Very little is known of complement regulators in non-mammalian species. We isolated and sequenced four highly similar complement factor I cDNAs from the liver of the nurse shark (Ginglymostoma cirratum), designated as GcIf-1, GcIf-2, GcIf-3 and GcIf-4 (previously referred to as nsFI-a, -b, -c and -d) which encode 689, 673, 673 and 657 amino acid residues, respectively. They share 95% (

Characterization of shark complement factor I gene(s): genomic analysis of a novel shark-specific sequence

PubMed Central

Shin, Dong-Ho; Webb, Barbara M.; Nakao, Miki; Smith, Sylvia L.

2009-01-01

Complement factor I is a crucial regulator of mammalian complement activity. Very little is known of complement regulators in non-mammalian species. We isolated and sequenced four highly similar complement factor I cDNAs from the liver of the nurse shark (Ginglymostoma cirratum), designated as GcIf-1, GcIf-2, GcIf-3 and GcIf-4 (previously referred to as nsFI-a, -b, -c and –d) which encode 689, 673, 673 and 657 amino acid residues, respectively. They share 95% (≤) amino acid identities with each other, 35.4 ~ 39.6% and 62.8 ~ 65.9% with factor I of mammals and banded houndshark (Triakis scyllium), respectively. The modular structure of the GcIf is similar to that of mammals with one notable exception, the presence of a novel shark-specific sequence between the leader peptide (LP) and the factor I membrane attack complex (FIMAC) domain. The cDNA sequences differ only in the size and composition of the shark-specific region (SSR). Sequence analysis of each SSR has identified within the region two novel short sequences (SS1 and SS2) and three repeat sequences (RS1, 2 and 3). Genomic analysis has revealed the existence of three introns between the leader peptide and the FIMAC domain, tentatively designated intron 1, intron 2, and intron 3 which span 4067, 2293 and 2082 bp, respectively. Southern blot analysis suggests the presence of a single gene copy for each cDNA type. Phylogenetic analysis suggests that complement factor I of cartilaginous fish diverged prior to the emergence of mammals. All four GcIf cDNA species are expressed in four different tissues and the liver is the main tissue in which expression level of all four is high. This suggests that the expression of GcIf isotypes is tissue-dependent. PMID:19423168

Trauma team leaders' non-verbal communication: video registration during trauma team training.

PubMed

Härgestam, Maria; Hultin, Magnus; Brulin, Christine; Jacobsson, Maritha

2016-03-25

There is widespread consensus on the importance of safe and secure communication in healthcare, especially in trauma care where time is a limiting factor. Although non-verbal communication has an impact on communication between individuals, there is only limited knowledge of how trauma team leaders communicate. The purpose of this study was to investigate how trauma team members are positioned in the emergency room, and how leaders communicate in terms of gaze direction, vocal nuances, and gestures during trauma team training. Eighteen trauma teams were audio and video recorded during trauma team training in the emergency department of a hospital in northern Sweden. Quantitative content analysis was used to categorize the team members' positions and the leaders' non-verbal communication: gaze direction, vocal nuances, and gestures. The quantitative data were interpreted in relation to the specific context. Time sequences of the leaders' gaze direction, speech time, and gestures were identified separately and registered as time (seconds) and proportions (%) of the total training time. The team leaders who gained control over the most important area in the emergency room, the "inner circle", positioned themselves as heads over the team, using gaze direction, gestures, vocal nuances, and verbal commands that solidified their verbal message. Changes in position required both attention and collaboration. Leaders who spoke in a hesitant voice, or were silent, expressed ambiguity in their non-verbal communication: and other team members took over the leader's tasks. In teams where the leader had control over the inner circle, the members seemed to have an awareness of each other's roles and tasks, knowing when in time and where in space these tasks needed to be executed. Deviations in the leaders' communication increased the ambiguity in the communication, which had consequences for the teamwork. Communication cannot be taken for granted; it needs to be practiced regularly just as technical skills need to be trained. Simulation training provides healthcare professionals the opportunity to put both verbal and non-verbal communication in focus, in order to improve patient safety. Non-verbal communication plays a decisive role in the interaction between the trauma team members, and so both verbal and non-verbal communication should be in focus in trauma team training. This is even more important for inexperienced leaders, since vague non-verbal communication reinforces ambiguity and can lead to errors.

Identification of a gag-encoded cytotoxic T-lymphocyte epitope from FBL-3 leukemia shared by Friend, Moloney, and Rauscher murine leukemia virus-induced tumors.

PubMed Central

Chen, W; Qin, H; Chesebro, B; Cheever, M A

1996-01-01

FBL-3 is a highly immunogenic murine leukemia of C57BL/6 origin induced by Friend murine leukemia virus (MuLV). Immunization of C57BL/6 mice with FBL-3 readily elicits CD8+ cytotoxic T lymphocytes (CTL) capable of lysing FBL-3 as well as syngeneic leukemias induced by Moloney and Rauscher MuLV. The aim of this current study was to identify the immunogenic epitope(s) recognized by the FBL-3-specific CD8+ CTL. A series of FBL-3-specific CD8+ CTL clones were generated from C57BL/6 mice immunized to FBL-3. The majority of CTL clones (32 of 38) were specific for F-MuLV gag-encoded antigen. By using a series of recombinant vaccinia viruses expressing full-length and truncated F-MuLV gag genes, the antigenic epitope recognized by the FBL-3 gag-specific CTL clones, as well as by bulk-cultured CTL from spleens of mice immune to FBL-3, was localized to the leader sequence of gPr80gag protein. The precise amino acid sequence of the CTL epitope in the leader sequence was identified as CCLCLTVFL (positions 85-93) by examining lysis of targets incubated with a series of synthetic leader sequence peptides. No evidence of other CTL epitopes in the gPr80gag or Pr65gag core virion structural polyproteins was found. The identity of CCLCLTVFL as the target peptide was validated by showing that immunization with the peptide elicited CTL that lysed FBL-3. The CTL elicited by the Gag peptide also specifically lysed syngeneic leukemia cells induced by Moloney and Rauscher MuLV (MBL-2 and RBL-5). The transmembrane peptide was shown to be the major gag-encoded antigenic epitope recognized by bulk-cultured CTL derived from C57BL/6 mice immunized to MBL-2 or RBL-5. Thus, the CTL epitope of FBL-3 is localized to the transmembrane anchor domain of the nonstructural Gag polyprotein and is shared by leukemia/lymphoma cell lines induced by Friend, Moloney, and Rauscher MuLV. PMID:8892898

Nucleotide sequence of the Varkud mitochondrial plasmid of Neurospora and synthesis of a hybrid transcript with a 5' leader derived from mitochondrial RNA.

PubMed

Akins, R A; Grant, D M; Stohl, L L; Bottorff, D A; Nargang, F E; Lambowitz, A M

1988-11-05

The Mauriceville and Varkud mitochondrial plasmids of Neurospora are closely related, closed circular DNAs (3.6 and 3.7 kb, respectively; 1 kb = 10(3) bases or base-pairs), whose characteristics suggest relationships to mitochondrial DNA introns and retrotransposons. Here, we characterized the structure of the Varkud plasmid, determined its complete nucleotide sequence and mapped its major transcripts. The Mauriceville and Varkud plasmids have more than 97% positional identity. Both plasmids contain a 710 amino acid open reading frame that encodes a reverse transcriptase-like protein. The amino acid sequence of this open reading frame is strongly conserved between the two plasmids (701/710 amino acids) as expected for a functionally important protein. Both plasmids have a 0.4 kb region that contains five PstI palindromes and a direct repeat of approximately 160 base-pairs. Comparison of sequences in this region suggests that the Varkud plasmid has diverged less from a common ancestor than has the Mauriceville plasmid. Two major transcripts of the Varkud plasmid were detected by Northern hybridization experiments: a full-length linear RNA of 3.7 kb and an additional prominent transcript of 4.9 kb, 1.2 kb longer than monomer plasmid. Remarkably, we find that the 4.9 kb transcript is a hybrid RNA consisting of the full-length 3.7 kb Varkud plasmid transcript plus a 5' leader of 1.2 kb that is derived from the 5' end of the mitochondrial small rRNA. This and other findings suggest that the Varkud plasmid, like certain RNA viruses, has a mechanism for joining heterologous RNAs to the 5' end of its major transcript, and that, under some circumstances, nucleotide sequences in mitochondria may be recombined at the RNA level.

Dynamics of streamer-to-leader transition at reduced air densities and its implications for propagation of lightning leaders and gigantic jets

NASA Astrophysics Data System (ADS)

da Silva, Caitano L.; Pasko, Victor P.

2013-12-01

In this paper we present modeling studies of air heating by electrical discharges in a wide range of pressures. The developed model is capable of quantifying the different contributions for heating of air at the particle level and rigorously accounts for the vibration-dissociation-vibration coupling. The model is validated by calculating the breakdown times of short air gaps and comparing to available experimental data. Detailed discussion on the role of electron detachment in the development of the thermal-ionizational instability that triggers the spark development in short air gaps is presented. The dynamics of fast heating by quenching of excited electronic states is discussed and the scaling of its main channels with ambient air density is quantified. The developed model is employed to study the streamer-to-leader transition process and to obtain its scaling with ambient air density. Streamer-to-leader transition is the name given to a sequence of events occurring in a thin plasma channel through which a relatively strong current is forced through, culminating in heating of ambient gas and increase of the electrical conductivity of the channel. This process occurs during the inception of leaders (from sharp metallic structures, from hydrometeors inside the thundercloud, or in virgin air) and during their propagation (at the leader head or during the growth of a space leader). The development of a thermal-ionizational instability that culminates in the leader formation and propagation is characterized by a change in air ionization mechanism from electron impact to associative ionization and by contraction of the plasma channel. The introduced methodology for estimation of leader speeds shows that the propagation of a leader is limited by the air heating of every newly formed leader section. It is demonstrated that the streamer-to-leader transition time has an inverse-squared dependence on the ambient air density at near-ground pressures, in agreement with similarity laws for Joule heating in a streamer channel. Model results indicate that a deviation from this similarity scaling occurs at very low air densities, where the rate of electronic power deposition is balanced by the channel expansion, and air heating from quenching of excited electronic states is very inefficient. These findings place a limit on the maximum altitude at which a hot and highly conducting lightning leader channel can be formed in the Earth's atmosphere, result which is important for understating of the gigantic jet (GJ) discharges between thundercloud tops and the lower ionosphere. Simulations of leader speeds at GJ altitudes demonstrate that initial speeds of GJs are consistent with the leader propagation mechanism. The simulation of a GJ, escaping upward from a thundercloud top, shows that the lengthening of the leader streamer zone, in a medium of exponentially decreasing air density, determines the existence of an altitude at which the streamer zones of GJs become so long that they dynamically extend (jump) all the way to the ionosphere.

[Bioinformatics Analysis of Clustered Regularly Interspaced Short Palindromic Repeats in the Genomes of Shigella].

PubMed

Wang, Pengfei; Wang, Yingfang; Duan, Guangcai; Xue, Zerun; Wang, Linlin; Guo, Xiangjiao; Yang, Haiyan; Xi, Yuanlin

2015-04-01

This study was aimed to explore the features of clustered regularly interspaced short palindromic repeats (CRISPR) structures in Shigella by using bioinformatics. We used bioinformatics methods, including BLAST, alignment and RNA structure prediction, to analyze the CRISPR structures of Shigella genomes. The results showed that the CRISPRs existed in the four groups of Shigella, and the flanking sequences of upstream CRISPRs could be classified into the same group with those of the downstream. We also found some relatively conserved palindromic motifs in the leader sequences. Repeat sequences had the same group with corresponding flanking sequences, and could be classified into two different types by their RNA secondary structures, which contain "stem" and "ring". Some spacers were found to homologize with part sequences of plasmids or phages. The study indicated that there were correlations between repeat sequences and flanking sequences, and the repeats might act as a kind of recognition mechanism to mediate the interaction between foreign genetic elements and Cas proteins.

Cultivating Self-Awareness with Team-Teaching: Connections between Classroom Learning and Experiential Learning

ERIC Educational Resources Information Center

Polk, Denise M.

2013-01-01

The Honors College program prepares leaders for the 21st century to become forces for positive change through problem-solving, scholarship, service, teamwork, and leadership. Its structure involves nine sequenced courses familiarizing students with challenges facing communities. Courses are team-taught by professors in different disciplines to…

Feline immunodeficiency virus (FIV) env recombinants are common in natural infections.

PubMed

Bęczkowski, Paweł M; Hughes, Joseph; Biek, Roman; Litster, Annette; Willett, Brian J; Hosie, Margaret J

2014-09-17

Recombination is a common feature of retroviral biology and one of the most important factors responsible for generating viral diversity at both the intra-host and the population levels. However, relatively little is known about rates and molecular processes of recombination for retroviruses other than HIV, including important model viruses such as feline immunodeficiency virus (FIV). We investigated recombination in complete FIV env gene sequences (n = 355) isolated from 43 naturally infected cats. We demonstrated that recombination is abundant in natural FIV infection, with over 41% of the cats being infected with viruses containing recombinant env genes. In addition, we identified shared recombination breakpoints; the most significant hotspot occurred between the leader/signal fragment and the remainder of env. Our results have identified the leader/signal fragment of env as an important site for recombination and highlight potential limitations of the current phylogenetic classification of FIV based on partial env sequences. Furthermore, the presence of abundant recombinant FIV in the USA poses a significant challenge for commercial diagnostic tests and should inform the development of the next generation of FIV vaccines.

Nucleotide sequence analysis of the L gene of Newcastle disease virus: homologies with Sendai and vesicular stomatitis viruses.

PubMed Central

Yusoff, K; Millar, N S; Chambers, P; Emmerson, P T

1987-01-01

The nucleotide sequence of the L gene of the Beaudette C strain of Newcastle disease virus (NDV) has been determined. The L gene is 6704 nucleotides long and encodes a protein of 2204 amino acids with a calculated molecular weight of 248822. Mung bean nuclease mapping of the 5' terminus of the L gene mRNA indicates that the transcription of the L gene is initiated 11 nucleotides upstream of the translational start site. Comparison with the amino acid sequences of the L genes of Sendai virus and vesicular stomatitis virus (VSV) suggests that there are several regions of homology between the sequences. These data provide further evidence for an evolutionary relationship between the Paramyxoviridae and the Rhabdoviridae. A non-coding sequence of 46 nucleotides downstream of the presumed polyadenylation site of the L gene may be part of a negative strand leader RNA. Images PMID:3035486

Trans splicing in Leishmania enriettii and identification of ribonucleoprotein complexes containing the spliced leader and U2 equivalent RNAs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, S.I.; Wirth, D.F.

1988-06-01

The 5' ends of Leishmania mRNAs contain an identical 35-nucleotide sequence termed the spliced leader (SL) or 5' mini-exon. The SL sequence is at the 5' end of an 85-nucleotide primary transcript that contains a consensus eucaryotic 5' intron-exon splice junction immediately 3' to the SL. The SL is added to protein-coding genes immediately 3' to a consensus eucaryotic 3' intron-exon splice junction. The authors' previous work demonstrated possible intermediates in discontinuous mRNA processing that contain the 50 nucleotides of the SL primary transcript 3' to the SL, the SL intron sequence (SLIS). These RNAs have a 5' terminus atmore » the splice junction of the SL and the SLIS. The authors examined a Leishmania nuclear extract for these RNAs in ribonucleoprotein (RNP) particles. Density centrifugation analysis showed that the SL RNA is predominately in RNP complexes at 60S, while the SLIS-containing RNAs are in complexes at 40S. They also demonstrated that the SLIS can be released from polyadenylated RNA by incubation with a HeLa cell extract containing debranching enzymatic activity. These data suggested that Leishmania enriettii mRNAs are assembled by bimolecular or trans splicing as has been recently demonstrated for Trypanosoma brucei. Furthermore, they determined the partial sequence of the Leishmania U2 equivalent RNA and demonstrated that it cosediments with the SL RNA at 60S in a nuclear extract. These RNP particles may be analogous to so-called spliceosomes that have been demonstrated in other systems.« less

Two groups of phenylalanine biosynthetic operon leader peptides genes: a high level of apparently incidental frameshifting in decoding Escherichia coli pheL

PubMed Central

Gurvich, Olga L.; Näsvall, S. Joakim; Baranov, Pavel V.; Björk, Glenn R.; Atkins, John F.

2011-01-01

The bacterial pheL gene encodes the leader peptide for the phenylalanine biosynthetic operon. Translation of pheL mRNA controls transcription attenuation and, consequently, expression of the downstream pheA gene. Fifty-three unique pheL genes have been identified in sequenced genomes of the gamma subdivision. There are two groups of pheL genes, both of which are short and contain a run(s) of phenylalanine codons at an internal position. One group is somewhat diverse and features different termination and 5′-flanking codons. The other group, mostly restricted to Enterobacteria and including Escherichia coli pheL, has a conserved nucleotide sequence that ends with UUC_CCC_UGA. When these three codons in E. coli pheL mRNA are in the ribosomal E-, P- and A-sites, there is an unusually high level, 15%, of +1 ribosomal frameshifting due to features of the nascent peptide sequence that include the penultimate phenylalanine. This level increases to 60% with a natural, heterologous, nascent peptide stimulator. Nevertheless, studies with different tRNAPro mutants in Salmonella enterica suggest that frameshifting at the end of pheL does not influence expression of the downstream pheA. This finding of incidental, rather than utilized, frameshifting is cautionary for other studies of programmed frameshifting. PMID:21177642

A Unified Model of Cloud-to-Ground Lightning Stroke

NASA Astrophysics Data System (ADS)

Nag, A.; Rakov, V. A.

2014-12-01

The first stroke in a cloud-to-ground lightning discharge is thought to follow (or be initiated by) the preliminary breakdown process which often produces a train of relatively large microsecond-scale electric field pulses. This process is poorly understood and rarely modeled. Each lightning stroke is composed of a downward leader process and an upward return-stroke process, which are usually modeled separately. We present a unified engineering model for computing the electric field produced by a sequence of preliminary breakdown, stepped leader, and return stroke processes, serving to transport negative charge to ground. We assume that a negatively-charged channel extends downward in a stepped fashion through the relatively-high-field region between the main negative and lower positive charge centers and then through the relatively-low-field region below the lower positive charge center. A relatively-high-field region is also assumed to exist near ground. The preliminary breakdown pulse train is assumed to be generated when the negatively-charged channel interacts with the lower positive charge region. At each step, an equivalent current source is activated at the lower extremity of the channel, resulting in a step current wave that propagates upward along the channel. The leader deposits net negative charge onto the channel. Once the stepped leader attaches to ground (upward connecting leader is presently neglected), an upward-propagating return stroke is initiated, which neutralizes the charge deposited by the leader along the channel. We examine the effect of various model parameters, such as step length and current propagation speed, on model-predicted electric fields. We also compare the computed fields with pertinent measurements available in the literature.

The maize stripe virus major noncapsid protein messenger RNA transcripts contain heterogeneous leader sequences at their 5' termini.

PubMed

Huiet, L; Feldstein, P A; Tsai, J H; Falk, B W

1993-12-01

Primer extension analyses and a PCR-based cloning strategy were used to identify and characterize 5' nucleotide sequences on the maize stripe virus (MStV) RNA4 mRNA transcripts encoding the major noncapsid protein (NCP). Direct RNA sequence analysis by primer extension showed that the NCP mRNA transcripts had 10-15 nucleotides beyond the 5' terminus of the MStV RNA4 nucleotide sequence. MStV genomic RNAs isolated from ribonucleoprotein particles (RNPs) lacked the additional 5' nucleotides. cDNA clones representing the 5' region of the mRNA transcripts were constructed, and the nucleotide sequences of the 5' regions were determined for 16 clones. Each was found to have a distinct 10-15 nucleotide sequence immediately 5' of the MStV RNA4 sequence. Eleven of 16 clones had the correct MStV RNA4 5' nucleotide sequence, while five showed minor variations at or near the 5' most MStV RNA4 nucleotide. These characteristics show strong similarities to other viral mRNA transcripts which are synthesized by cap snatching.

A Study of Attrition and the Use of Student Learning Communities in the Computer Science Introductory Programming Sequence

ERIC Educational Resources Information Center

Howles, Trudy

2009-01-01

Student attrition and low graduation rates are critical problems in computer science education. Disappointing graduation rates and declining student interest have caught the attention of business leaders, researchers and universities. With weak graduation rates and little interest in scientific computing, many are concerned about the USA's ability…

National Groups Call for Big Changes in Remedial Education

ERIC Educational Resources Information Center

Mangan, Katherine

2012-01-01

Remedial courses meant to get underprepared students ready for college-level work are often not an on-ramp but a dead end, leaders of four national higher-education groups said, recommending sweeping changes in how such students are brought up to speed. Students required to take a sequence of remedial, or developmental, courses before they can…

Textile Science Leader's Guide. 4-H Textile Science.

ERIC Educational Resources Information Center

Scholl, Jan

This instructor's guide provides an overview of 4-H student project modules in the textile sciences area. The guide includes short notes explaining how to use the project modules, a flowchart chart showing how the project areas are sequenced, a synopsis of the design and content of the modules, and some program planning tips. For each of the…

Leading the Game, Losing the Competition: Identifying Leaders and Followers in a Repeated Game

PubMed Central

Seip, Knut Lehre; Grøn, Øyvind

2016-01-01

We explore a new method for identifying leaders and followers, LF, in repeated games by analyzing an experimental, repeated (50 rounds) game where Row player shifts the payoff between small and large values–a type of “investor” and Column player determines who gets the payoff–a type of “manager”. We found that i) the Investor (Row) most often is a leading player and the manager (Column) a follower. The longer the Investor leads the game, the higher is both player’s payoff. Surprisingly however, it is always the Manager that achieves the largest payoff. ii) The game has an efficient cooperative strategy where the players alternate in receiving a high payoff, but the players never identify, or accept, that strategy. iii) Under the assumption that the information used by the players is closely associated with the leader- follower sequence, and that information is available before the player’s decisions are made, the players switched LF- strategy primarily as a function of information on the Investor’s investment and moves and secondly as a function of the Manager’s payoff. PMID:26968032

Leaders and followers: quantifying consistency in spatio-temporal propagation patterns

NASA Astrophysics Data System (ADS)

Kreuz, Thomas; Satuvuori, Eero; Pofahl, Martin; Mulansky, Mario

2017-04-01

Repetitive spatio-temporal propagation patterns are encountered in fields as wide-ranging as climatology, social communication and network science. In neuroscience, perfectly consistent repetitions of the same global propagation pattern are called a synfire pattern. For any recording of sequences of discrete events (in neuroscience terminology: sets of spike trains) the questions arise how closely it resembles such a synfire pattern and which are the spike trains that lead/follow. Here we address these questions and introduce an algorithm built on two new indicators, termed SPIKE-order and spike train order, that define the synfire indicator value, which allows to sort multiple spike trains from leader to follower and to quantify the consistency of the temporal leader-follower relationships for both the original and the optimized sorting. We demonstrate our new approach using artificially generated datasets before we apply it to analyze the consistency of propagation patterns in two real datasets from neuroscience (giant depolarized potentials in mice slices) and climatology (El Niño sea surface temperature recordings). The new algorithm is distinguished by conceptual and practical simplicity, low computational cost, as well as flexibility and universality.

7 CFR 29.75a - Display of burley tobacco on auction warehouse floors in designated markets.

Code of Federal Regulations, 2010 CFR

2010-01-01

... in designated markets. 29.75a Section 29.75a Agriculture Regulations of the Department of Agriculture... § 29.75a Display of burley tobacco on auction warehouse floors in designated markets. (a)(1) Each lot... arrayed sequence of lots and rows of tobacco, shall have prior approval of the Set Work Leader or Circuit...

Examining the Impact of Study and Test Taking Strategies on Student Perceptions' of Their Performance Expectancy: An Action Research Study

ERIC Educational Resources Information Center

Trexler, Deborah A.

2016-01-01

As military connected students transition, the scope and sequencing of courses and expectations for standardized testing is often inconsistent and unpredictable. Military leaders work diligently with education agencies to develop programs and legislature which levels the playing field for these students in order to provide them the most…

Leaderless mRNAs are circularized in Chlamydomonas reinhardtii mitochondria.

PubMed

Cahoon, A Bruce; Qureshi, Ali A

2018-06-01

The mitochondrial genome of Chlamydomonas reinhardtii encodes eight protein coding genes transcribed on two polycistronic primary transcripts. The mRNAs are endonucleolytically cleaved from these transcripts directly upstream of their AUG start codons, creating leaderless mRNAs with 3' untranslated regions (UTR) comprised of most or all of their downstream intergenic regions. In this report, we provide evidence that these processed linear mRNAs are circularized, which places the 3' UTR upstream of the 5' start codon, creating a leader sequence ex post facto. The circular mRNAs were found to be ribosome associate by polysome profiling experiments suggesting they are translated. Sequencing of the 3'-5' junctions of the circularized mRNAs found the intra-molecular ligations occurred between fully processed 5' ends (the start AUG) and a variable 3' terminus. For five genes (cob, cox, nd2, nd4, and nd6), some of the 3' ends maintained an oligonucleotide addition during ligation, and for two of them, cob and nd6, these 3' termini were the most commonly recovered sequence. Previous reports have shown that after cleavage, three untemplated oligonucleotide additions may occur on the 3' termini of these mRNAs-adenylation, uridylylation, or cytidylation. These results suggest oligo(U) and oligo(C) additions may be part of the maturation process since they are maintained in the circular mRNAs. Circular RNAs occur in organisms across the biological spectrum, but their purpose in some systems, such as organelles (mitochondria and chloroplasts) is unclear. We hypothesize, that in C. reinhardtii mitochondria it may create a leader sequence to facilitate translation initiation, which may negate the need for an alternative translation initiation mechanism in this system, as previously speculated. In addition, circularization may play a protective role against exonucleases, and/or increase translational productivity.

A structural basis for antigen presentation by the MHC class Ib molecule, Qa-1b.

PubMed

Zeng, Li; Sullivan, Lucy C; Vivian, Julian P; Walpole, Nicholas G; Harpur, Christopher M; Rossjohn, Jamie; Clements, Craig S; Brooks, Andrew G

2012-01-01

The primary function of the monomorphic MHC class Ib molecule Qa-1(b) is to present peptides derived from the leader sequences of other MHC class I molecules for recognition by the CD94-NKG2 receptors expressed by NK and T cells. Whereas the mode of peptide presentation by its ortholog HLA-E, and subsequent recognition by CD94-NKG2A, is known, the molecular basis of Qa-1(b) function is unclear. We have assessed the interaction between Qa-1(b) and CD94-NKG2A and shown that they interact with an affinity of 17 μM. Furthermore, we have determined the structure of Qa-1(b) bound to the leader sequence peptide, Qdm (AMAPRTLLL), to a resolution of 1.9 Å and compared it with that of HLA-E. The crystal structure provided a basis for understanding the restricted peptide repertoire of Qa-1(b). Whereas the Qa-1(b-AMAPRTLLL) complex was similar to that of HLA-E, significant sequence and structural differences were observed between the respective Ag-binding clefts. However, the conformation of the Qdm peptide bound by Qa-1(b) was very similar to that of peptide bound to HLA-E. Although a number of conserved innate receptors can recognize heterologous ligands from other species, the structural differences between Qa-1(b) and HLA-E manifested in CD94-NKG2A ligand recognition being species specific despite similarities in peptide sequence and conformation. Collectively, our data illustrate the structural homology between Qa-1(b) and HLA-E and provide a structural basis for understanding peptide repertoire selection and the specificity of the interaction of Qa-1(b) with CD94-NKG2 receptors.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leong, JoAnn Ching

The nucleotide sequence of the IHNV glycoprotein gene has been determined from a cDNA clone containing the entire coding region. The glycoprotein cDNA clone contained a leader sequence of 48 bases, a coding region of 1524 nucleotides, and 39 bases at the 3 foot end. The entire cDNA clone contains 1609 nucleodites and encodes a protein of 508 amino acids. The deduced amino acid sequence gave a translated molecular weight of 56,795 daltons. A hydropathicity profile of the deduced amino acid sequence indicated that there were two major hydrophobic domains: one,at the N-terminus,delineating a signal peptide of 18 amino acidsmore » and the other, at the C-terminus,delineating the region of the transmembrane. Five possible sites of N-linked glyscoylation were identified. Although no nucleic acid homology existed between the IHNV glycoprotein gene and the glycoprotein genes of rabies and VSV, there was significant homology at the amino acid level between all three rhabdovirus glycoproteins.« less

Cloning and expression of cDNA coding for bouganin.

PubMed

den Hartog, Marcel T; Lubelli, Chiara; Boon, Louis; Heerkens, Sijmie; Ortiz Buijsse, Antonio P; de Boer, Mark; Stirpe, Fiorenzo

2002-03-01

Bouganin is a ribosome-inactivating protein that recently was isolated from Bougainvillea spectabilis Willd. In this work, the cloning and expression of the cDNA encoding for bouganin is described. From the cDNA, the amino-acid sequence was deduced, which correlated with the primary sequence data obtained by amino-acid sequencing on the native protein. Bouganin is synthesized as a pro-peptide consisting of 305 amino acids, the first 26 of which act as a leader signal while the 29 C-terminal amino acids are cleaved during processing of the molecule. The mature protein consists of 250 amino acids. Using the cDNA sequence encoding the mature protein of 250 amino acids, a recombinant protein was expressed, purified and characterized. The recombinant molecule had similar activity in a cell-free protein synthesis assay and had comparable toxicity on living cells as compared to the isolated native bouganin.

Rapid and Easy Protocol for Quantification of Next-Generation Sequencing Libraries.

PubMed

Hawkins, Steve F C; Guest, Paul C

2018-01-01

The emergence of next-generation sequencing (NGS) over the last 10 years has increased the efficiency of DNA sequencing in terms of speed, ease, and price. However, the exact quantification of a NGS library is crucial in order to obtain good data on sequencing platforms developed by the current market leader Illumina. Different approaches for DNA quantification are available currently and the most commonly used are based on analysis of the physical properties of the DNA through spectrophotometric or fluorometric methods. Although these methods are technically simple, they do not allow exact quantification as can be achieved using a real-time quantitative PCR (qPCR) approach. A qPCR protocol for DNA quantification with applications in NGS library preparation studies is presented here. This can be applied in various fields of study such as medical disorders resulting from nutritional programming disturbances.

Nucleotide sequence analysis of the gene encoding the Deinococcus radiodurans surface protein, derived amino acid sequence, and complementary protein chemical studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, J.; Peters, M.; Lottspeich, F.

1987-11-01

The complete nucleotide sequence of the gene encoding the surface (hexagonally packed intermediate (HPI))-layer polypeptide of Deinococcus radiodurans Sark was determined and found to encode a polypeptide of 1036 amino acids. Amino acid sequence analysis of about 30% of the residues revealed that the mature polypeptide consists of at least 978 amino acids. The N terminus was blocked to Edman degradation. The results of proteolytic modification of the HPI layer in situ and M/sub r/ estimations of the HPI polypeptide expressed in Escherichia coli indicated that there is a leader sequence. The N-terminal region contained a very high percentage (29%)more » of threonine and serine, including a cluster of nine consecutive serine or threonine residues, whereas a stretch near the C terminus was extremely rich in aromatic amino acids (29%). The protein contained at least two disulfide bridges, as well as tightly bound reducing sugars and fatty acids.« less

Analysis of expressed sequence tags of the cyclically parthenogenetic rotifer Brachionus plicatilis.

PubMed

Suga, Koushirou; Welch, David Mark; Tanaka, Yukari; Sakakura, Yoshitaka; Hagiwara, Atsushi

2007-08-01

Rotifers are among the most common non-arthropod animals and are the most experimentally tractable members of the basal assemblage of metazoan phyla known as Gnathifera. The monogonont rotifer Brachionus plicatilis is a developing model system for ecotoxicology, aquatic ecology, cryptic speciation, and the evolution of sex, and is an important food source for finfish aquaculture. However, basic knowledge of the genome and transcriptome of any rotifer species has been lacking. We generated and partially sequenced a cDNA library from B. plicatilis and constructed a database of over 2300 expressed sequence tags corresponding to more than 450 transcripts. About 20% of the transcripts had no significant similarity to database sequences by BLAST; most of these contained open reading frames of significant length but few had recognized Pfam motifs. Sixteen transcripts accounted for 25% of the ESTs; four of these had no significant similarity to BLAST or Pfam databases. Putative up- and downstream untranslated regions are relatively short and AT rich. In contrast to bdelloid rotifers, there was no evidence of a conserved trans-spliced leader sequence among the transcripts and most genes were single-copy. Despite the small size of this EST project it revealed several important features of the rotifer transcriptome and of individual monogonont genes. Because there is little genomic data for Gnathifera, the transcripts we found with no known function may represent genes that are species-, class-, phylum- or even superphylum-specific; the fact that some are among the most highly expressed indicates their importance. The absence of trans-spliced leader exons in this monogonont species contrasts with their abundance in bdelloid rotifers and indicates that the presence of this phenomenon can vary at the subphylum level. Our EST database provides a relatively large quantity of transcript-level data for B. plicatilis, and more generally of rotifers and other gnathiferan phyla, and can be browsed and searched at gmod.mbl.edu.

Analysis of Expressed Sequence Tags of the Cyclically Parthenogenetic Rotifer Brachionus plicatilis

PubMed Central

Suga, Koushirou; Mark Welch, David; Tanaka, Yukari; Sakakura, Yoshitaka; Hagiwara, Atsushi

2007-01-01

Background Rotifers are among the most common non-arthropod animals and are the most experimentally tractable members of the basal assemblage of metazoan phyla known as Gnathifera. The monogonont rotifer Brachionus plicatilis is a developing model system for ecotoxicology, aquatic ecology, cryptic speciation, and the evolution of sex, and is an important food source for finfish aquaculture. However, basic knowledge of the genome and transcriptome of any rotifer species has been lacking. Methodology/Principal Findings We generated and partially sequenced a cDNA library from B. plicatilis and constructed a database of over 2300 expressed sequence tags corresponding to more than 450 transcripts. About 20% of the transcripts had no significant similarity to database sequences by BLAST; most of these contained open reading frames of significant length but few had recognized Pfam motifs. Sixteen transcripts accounted for 25% of the ESTs; four of these had no significant similarity to BLAST or Pfam databases. Putative up- and downstream untranslated regions are relatively short and AT rich. In contrast to bdelloid rotifers, there was no evidence of a conserved trans-spliced leader sequence among the transcripts and most genes were single-copy. Conclusions/Significance Despite the small size of this EST project it revealed several important features of the rotifer transcriptome and of individual monogonont genes. Because there is little genomic data for Gnathifera, the transcripts we found with no known function may represent genes that are species-, class-, phylum- or even superphylum-specific; the fact that some are among the most highly expressed indicates their importance. The absence of trans-spliced leader exons in this monogonont species contrasts with their abundance in bdelloid rotifers and indicates that the presence of this phenomenon can vary at the subphylum level. Our EST database provides a relatively large quantity of transcript-level data for B. plicatilis, and more generally of rotifers and other gnathiferan phyla, and can be browsed and searched at gmod.mbl.edu. PMID:17668053

[Comparative analysis of clustered regularly interspaced short palindromic repeats (CRISPRs) loci in the genomes of halophilic archaea].

PubMed

Zhang, Fan; Zhang, Bing; Xiang, Hua; Hu, Songnian

2009-11-01

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is a widespread system that provides acquired resistance against phages in bacteria and archaea. Here we aim to genome-widely analyze the CRISPR in extreme halophilic archaea, of which the whole genome sequences are available at present time. We used bioinformatics methods including alignment, conservation analysis, GC content and RNA structure prediction to analyze the CRISPR structures of 7 haloarchaeal genomes. We identified the CRISPR structures in 5 halophilic archaea and revealed a conserved palindromic motif in the flanking regions of these CRISPR structures. In addition, we found that the repeat sequences of large CRISPR structures in halophilic archaea were greatly conserved, and two types of predicted RNA secondary structures derived from the repeat sequences were likely determined by the fourth base of the repeat sequence. Our results support the proposal that the leader sequence may function as recognition site by having palindromic structures in flanking regions, and the stem-loop secondary structure formed by repeat sequences may function in mediating the interaction between foreign genetic elements and CAS-encoded proteins.

Complete sequence of the genome of avian paramyxovirus type 2 (strain Yucaipa) and comparison with other paramyxoviruses

PubMed Central

Subbiah, Madhuri; Xiao, Sa; Collins, Peter L.; Samal, Siba K

2009-01-01

The complete RNA genome sequence of avian paramyxovirus (APMV) serotype 2, strain Yucaipa isolated from chicken has been determined. With genome size of 14,904 nucleotides (nt), strain Yucaipa is consistent with the “rule of six” and is the smallest virus reported to date among the members of subfamily Paramyxovirinae. The genome contains six non-overlapping genes in the order 3′-N-P/V-M-F-HN-L-5′. The genes are flanked on either side by highly-conserved transcription start and stop signals and have intergenic sequences varying in length from 3 to 23 nt. The genome contains a 55 nt leader sequence at 3′ end and a 154 nt trailer sequence at 5′ end. Alignment and phylogenetic analysis of the predicted amino acid sequences of strain Yucaipa proteins with the cognate proteins of viruses of all of the five genera of family Paramyxoviridae showed that APMV-2 strain Yucaipa is more closely related to APMV-6 than APMV-1. PMID:18603323

Leadership of risk decision making in a complex, technology organization: The deliberative decision making model

NASA Astrophysics Data System (ADS)

Flaming, Susan C.

2007-12-01

The continuing saga of satellite technology development is as much a story of successful risk management as of innovative engineering. How do program leaders on complex, technology projects manage high stakes risks that threaten business success and satellite performance? This grounded theory study of risk decision making portrays decision leadership practices at one communication satellite company. Integrated product team (IPT) leaders of multi-million dollar programs were interviewed and observed to develop an extensive description of the leadership skills required to navigate organizational influences and drive challenging risk decisions to closure. Based on the study's findings the researcher proposes a new decision making model, Deliberative Decision Making, to describe the program leaders' cognitive and organizational leadership practices. This Deliberative Model extends the insights of prominent decision making models including the rational (or classical) and the naturalistic and qualifies claims made by bounded rationality theory. The Deliberative Model describes how leaders proactively engage resources to play a variety of decision leadership roles. The Model incorporates six distinct types of leadership decision activities, undertaken in varying sequence based on the challenges posed by specific risks. Novel features of the Deliberative Decision Model include: an inventory of leadership methods for managing task challenges, potential stakeholder bias and debates; four types of leadership meta-decisions that guide decision processes, and aligned organizational culture. Both supporting and constraining organizational influences were observed as leaders managed major risks, requiring active leadership on the most difficult decisions. Although the company's engineering culture emphasized the importance of data-based decisions, the uncertainties intrinsic to satellite risks required expert engineering judgment to be exercised throughout. An investigation into the co-variation of decision methods with uncertainty suggests that perceived risk severity may serve as a robust indicator for choices about decision practices. The Deliberative Decision processes incorporate multiple organizational and cultural controls as cross-checks to mitigate potential parochial bias of individuals, stakeholder groups, or leaders. Overall the Deliberative Decision framework describes how expert leadership practices, supportive organizational systems along with aligned cultural values and behavioral norms help leaders drive high stakes risk decisions to closure in this complex, advanced-technology setting.

Comparison of ZP3 protein sequences among vertebrate species: to obtain a consensus sequence for immunocontraception.

PubMed

Zhu, X; Naz, R K

1999-03-01

The deduced ZP3 amino acid (aa) sequences of 13 vertebrate species namely mouse, hamster, rabbit, pig, porcine, cow, dog, cat, human, bonnet, marmoset, carp, and frog were compared using the PILEUP and PRETTY alignment programs (GCG, Wisconsin, USA). The published aa sequences obtained from 13 vertebrate species indicated the overall evolutionarily conservation in the N-terminus, central region, and C-terminus of the ZP3 polypeptide. More variations of ZP3 polypeptide sequences were seen in the alignments of carp and frog from the 11 mammalian species making the leader sequence more prominent. The canonical furin proteolytic processing signal at the C-terminus was found in all the ZP3 polypeptide sequences except of carp and frog. In the central region, the ZP3 deduced aa sequences of all the 13 vertebrate species aligned well, and six relatively conserved sequences were found. There are 11 conserved cysteine residues in the central region across all species including carp and frog, indicating that these residues have longer evolutionary history. The ZP3 aa sequence similarities were examined using the GAP program (GCG). The highest aa similarities are observed between the members of the same order within the class mammalia, and also (95.4%) between pig (ungulata) and rabbit (lagomorpha). The deduced ZP3 aa sequences per se may not be enough to build a phylogenetic tree.

A Signature in HIV-1 Envelope Leader Peptide Associated with Transition from Acute to Chronic Infection Impacts Envelope Processing and Infectivity

PubMed Central

Asmal, Mohammed; Hellmann, Ina; Liu, Weimin; Keele, Brandon F.; Perelson, Alan S.; Bhattacharya, Tanmoy; Gnanakaran, S.; Daniels, Marcus; Haynes, Barton F.; Korber, Bette T.; Hahn, Beatrice H.; Shaw, George M.; Letvin, Norman L.

2011-01-01

Mucosal transmission of the human immunodeficiency virus (HIV) results in a bottleneck in viral genetic diversity. Gnanakaran and colleagues used a computational strategy to identify signature amino acids at particular positions in Envelope that were associated either with transmitted sequences sampled very early in infection, or sequences sampled during chronic infection. Among the strongest signatures observed was an enrichment for the stable presence of histidine at position 12 at transmission and in early infection, and a recurrent loss of histidine at position 12 in chronic infection. This amino acid lies within the leader peptide of Envelope, a region of the protein that has been shown to influence envelope glycoprotein expression and virion infectivity. We show a strong association between a positively charged amino acid like histidine at position 12 in transmitted/founder viruses with more efficient trafficking of the nascent envelope polypeptide to the endoplasmic reticulum and higher steady-state glycoprotein expression compared to viruses that have a non-basic position 12 residue, a substitution that was enriched among viruses sampled from chronically infected individuals. When expressed in the context of other viral proteins, transmitted envelopes with a basic amino acid position 12 were incorporated at higher density into the virus and exhibited higher infectious titers than did non-signature envelopes. These results support the potential utility of using a computational approach to examine large viral sequence data sets for functional signatures and indicate the importance of Envelope expression levels for efficient HIV transmission. PMID:21876761

Comparative analysis of CRISPR-Cas systems in Klebsiella genomes.

PubMed

Shen, Juntao; Lv, Li; Wang, Xudong; Xiu, Zhilong; Chen, Guoqiang

2017-04-01

Prokaryotic CRISPR-Cas system provides adaptive immunity against invasive genetic elements. Bacteria of the genus Klebsiella are important nosocomial opportunistic pathogens. However, information of CRISPR-Cas system in Klebsiella remains largely unknown. Here, we analyzed the CRISPR-Cas systems of 68 complete genomes of Klebsiella representing four species. All the elements for CRISPR-Cas system (cas genes, repeats, leader sequences, and PAMs) were characterized. Besides the typical Type I-E and I-F CRISPR-Cas systems, a new Subtype I system located in the ABC transport system-glyoxalase region was found. The conservation of the new subtype CRISPR system between different species showed new evidence for CRISPR horizontal transfer. CRISPR polymorphism was strongly correlated both with species and multilocus sequence types. Some results indicated the function of adaptive immunity: most spacers (112 of 124) matched to prophages and plasmids and no matching housekeeping genes; new spacer acquisition was observed within the same sequence type (ST) and same clonal complex; the identical spacers were observed only in the ancient position (far from the leader) between different STs and clonal complexes. Interestingly, a high ratio of self-targeting spacers (7.5%, 31 of 416) was found in CRISPR-bearing Klebsiella pneumoniae (61%, 11 of 18). In some strains, there even were multiple full matching self-targeting spacers. Some self-targeting spacers were conserved even between different STs. These results indicated that some unknown mechanisms existed to compromise the function of self-targets of CRISPR-Cas systems in K. pneumoniae. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Facilitating social support: member-leader communication in a breast cancer support group.

PubMed

Beck, Stephenson J; Keyton, Joann

2014-01-01

Early detection and treatment have resulted in more women surviving breast cancer; increased survivorship has also increased the need for breast cancer support groups (BCSG). The ostensible goal of such groups is to provide support for the physical and emotional stressors that cancer survivors face, as well as provide information on coping and treatment options. Although scholars have examined the effects of support groups on their group members, the examination of group facilitator messages has been largely neglected. The goal of this study was to extend theory on group leader behavior, specifically investigating how member-leader messages create social support in support groups. The transcribed conversations of weekly meetings of a BCSG were examined using Interaction Process Analysis to discover how the member-leader facilitated the group's enactment and management of social support. Across the meetings, task talk dominated (primarily statements of orientation or information). Furthermore, analysis of interaction sequences between the support group facilitator and other members revealed 2 broad categories of task-oriented facilitation techniques (changing the focus, clarification) and 1 category of socioemotional facilitation techniques (showing support). Support group facilitators need the ability to facilitate both task and relational aspects of social support. Facilitator behaviors were highlighted as being instrumental to the creation of social support. The results from this study indicate that the ability to change the focus of interaction, to provide and require clarification on complex issues, and to show support through relational messages is needed in facilitator training.

In vitro translocation experiments with RxLR-reporter fusion proteins of Avr1b from Phytophthora sojae and AVR3a from Phytophthora infestans fail to demonstrate specific autonomous uptake in plant and animal cells.

PubMed

Wawra, Stephan; Djamei, Armin; Albert, Isabell; Nürnberger, Thorsten; Kahmann, Regine; van West, Pieter

2013-05-01

Plant-pathogenic oomycetes have a large set of secreted effectors that can be translocated into their host cells during infection. One group of these effectors are the RxLR effectors for which it has been shown, in a few cases, that the RxLR motif is important for their translocation. It has been suggested that the RxLR-leader sequences alone are enough to translocate the respective effectors into eukaryotic cells through binding to surface-exposed phosphoinositol-3-phosphate. These conclusions were primary based on translocation experiments conducted with recombinant fusion proteins whereby the RxLR leader of RxLR effectors (i.e., Avr1b from Phytophthora sojae) were fused to the green fluorescent protein reporter-protein. However, we failed to observe specific cellular uptake for a comparable fusion protein where the RxLR leader of the P. infestans AVR3a was fused to monomeric red fluorescent protein. Therefore, we reexamined the ability of the reported P. sojae AVR1b RxLR leader to enter eukaryotic cells. Different relevant experiments were performed in three independent laboratories, using fluorescent reporter fusion constructs of AVR3a and Avr1b proteins in a side-by-side comparative study on plant tissue and human and animal cells. We report that we were unable to obtain conclusive evidence for specific RxLR-mediated translocation.

A distributed model predictive control scheme for leader-follower multi-agent systems

NASA Astrophysics Data System (ADS)

Franzè, Giuseppe; Lucia, Walter; Tedesco, Francesco

2018-02-01

In this paper, we present a novel receding horizon control scheme for solving the formation problem of leader-follower configurations. The algorithm is based on set-theoretic ideas and is tuned for agents described by linear time-invariant (LTI) systems subject to input and state constraints. The novelty of the proposed framework relies on the capability to jointly use sequences of one-step controllable sets and polyhedral piecewise state-space partitions in order to online apply the 'better' control action in a distributed receding horizon fashion. Moreover, we prove that the design of both robust positively invariant sets and one-step-ahead controllable regions is achieved in a distributed sense. Simulations and numerical comparisons with respect to centralised and local-based strategies are finally performed on a group of mobile robots to demonstrate the effectiveness of the proposed control strategy.

DNA motifs determining the accuracy of repeat duplication during CRISPR adaptation in Haloarcula hispanica

PubMed Central

Wang, Rui; Li, Ming; Gong, Luyao; Hu, Songnian; Xiang, Hua

2016-01-01

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) acquire new spacers to generate adaptive immunity in prokaryotes. During spacer integration, the leader-preceded repeat is always accurately duplicated, leading to speculations of a repeat-length ruler. Here in Haloarcula hispanica, we demonstrate that the accurate duplication of its 30-bp repeat requires two conserved mid-repeat motifs, AACCC and GTGGG. The AACCC motif was essential and needed to be ∼10 bp downstream from the leader-repeat junction site, where duplication consistently started. Interestingly, repeat duplication terminated sequence-independently and usually with a specific distance from the GTGGG motif, which seemingly served as an anchor site for a molecular ruler. Accordingly, altering the spacing between the two motifs led to an aberrant duplication size (29, 31, 32 or 33 bp). We propose the adaptation complex may recognize these mid-repeat elements to enable measuring the repeat DNA for spacer integration. PMID:27085805

Functional diversification upon leader protease domain duplication in the Citrus tristeza virus genome: Role of RNA sequences and the encoded proteins.

PubMed

Kang, Sung-Hwan; Atallah, Osama O; Sun, Yong-Duo; Folimonova, Svetlana Y

2018-01-15

Viruses from the family Closteroviridae show an example of intra-genome duplications of more than one gene. In addition to the hallmark coat protein gene duplication, several members possess a tandem duplication of papain-like leader proteases. In this study, we demonstrate that domains encoding the L1 and L2 proteases in the Citrus tristeza virus genome underwent a significant functional divergence at the RNA and protein levels. We show that the L1 protease is crucial for viral accumulation and establishment of initial infection, whereas its coding region is vital for virus transport. On the other hand, the second protease is indispensable for virus infection of its natural citrus host, suggesting that L2 has evolved an important adaptive function that mediates virus interaction with the woody host. Copyright © 2017 Elsevier Inc. All rights reserved.

Biochemical and Genetic Evidence that Enterococcus faecium L50 Produces Enterocins L50A and L50B, the sec-Dependent Enterocin P, and a Novel Bacteriocin Secreted without an N-Terminal Extension Termed Enterocin Q

PubMed Central

Cintas, Luis M.; Casaus, Pilar; Herranz, Carmen; Håvarstein, Leiv Sigve; Holo, Helge; Hernández, Pablo E.; Nes, Ingolf F.

2000-01-01

Enterococcus faecium L50 grown at 16 to 32°C produces enterocin L50 (EntL50), consisting of EntL50A and EntL50B, two unmodified non-pediocin-like peptides synthesized without an N-terminal leader sequence or signal peptide. However, the bacteriocin activity found in the cell-free culture supernatants following growth at higher temperatures (37 to 47°C) is not due to EntL50. A purification procedure including cation-exchange, hydrophobic interaction, and reverse-phase liquid chromatography has shown that the antimicrobial activity is due to two different bacteriocins. Amino acid sequences obtained by Edman degradation and DNA sequencing analyses revealed that one is identical to the sec-dependent pediocin-like enterocin P produced by E. faecium P13 (L. M. Cintas, P. Casaus, L. S. Håvarstein, P. E. Hernández, and I. F. Nes, Appl. Environ. Microbiol. 63:4321–4330, 1997) and the other is a novel unmodified non-pediocin-like bacteriocin termed enterocin Q (EntQ), with a molecular mass of 3,980. DNA sequencing analysis of a 963-bp region of E. faecium L50 containing the enterocin P structural gene (entP) and the putative immunity protein gene (entiP) reveals a genetic organization identical to that previously found in E. faecium P13. DNA sequencing analysis of a 1,448-bp region identified two consecutive but diverging open reading frames (ORFs) of which one, termed entQ, encodes a 34-amino-acid protein whose deduced amino acid sequence was identical to that obtained for EntQ by amino acid sequencing, showing that EntQ, similarly to EntL50A and EntL50B, is synthesized without an N-terminal leader sequence or signal peptide. The second ORF, termed orf2, was located immediately upstream of and in opposite orientation to entQ and encodes a putative immunity protein composed of 221 amino acids. Bacteriocin production by E. faecium L50 showed that EntP and EntQ are produced in the temperature range from 16 to 47°C and maximally detected at 47 and 37 to 47°C, respectively, while EntL50A and EntL50B are maximally synthesized at 16 to 25°C and are not detected at 37°C or above. PMID:11073927

Hydrolysis of VX and related compounds by organophosphorus hydrolase. Final report, Februray-December 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolakowski, J.E.; DeFrank, J.J.; Lai, K.

1995-11-01

Organophosphorus Hydrolase (OPH) is a fully characterized and cloned enzyme, derived from Pseudomonas diminuta, consisting of 365 amino acids with a total molecular weight of 38,0(X). The enzyme has a leader sequence of 29 amino acids which has been removed in the construction used in this study. OPH was evaluated for its effectiveness in catalyzing the S-(2-diisopwpylaminoethyl) methylphosphonothioate (VX) and its analogs.

Lightning channel current persists between strokes

NASA Astrophysics Data System (ADS)

Wendel, JoAnna

2014-09-01

The usual cloud-to-ground lightning occurs when a large negative charge contained in a "stepped leader" travels down toward the Earth's surface. It then meets a positive charge that comes up tens of meters from the ground, resulting in a powerful neutralizing explosion that begins the first return stroke of the lightning flash. The entire flash lasts only a few hundred milliseconds, but during that time, multiple subsequent stroke-return stroke sequences usually occur.

Transfer Learning for Adaptive Relation Extraction

DTIC Science & Technology

2011-09-13

other NLP tasks, however, supervised learning approach fails when there is not a sufficient amount of labeled data for training, which is often the case...always 12 Syntactic Pattern Relation Instance Relation Type (Subtype) arg-2 arg-1 Arab leaders OTHER-AFF (Ethnic) his father PER-SOC (Family) South...for x. For sequence labeling tasks in NLP , linear-chain conditional random field has been rather suc- cessful. It is an undirected graphical model in

Establishing collaborative structures and relationships: Teacher leaders' experiences

NASA Astrophysics Data System (ADS)

Canizo, Thea Lynne

2002-04-01

The purpose of this study was to explore teacher leaders' experiences as they attempted to establish collaborative structures and relationships resulting in improved science instruction at their schools. Teacher leaders were middle school science facilitators, full-time classroom teachers who acted as liaisons between the science teachers at their schools and a change initiative funded by the National Science Foundation. This was a qualitative study, using interviews to create a case study. The researcher used a three-part interview design developed by Seidman (1991). Six research questions served as a framework for the data analysis. Participants identified the following as factors which contributed to their success: support from the principal, other science teachers, central staff personnel, and the district-wide group of science facilitators; professional development; and the successful completion of a scope and sequence for science instruction. Factors identified as hindering their success were: lack of support or conflict with the principal; resistance to change; time constraints; a district policy which limited meeting time; teacher and administrator turnover; tension between the middle school and junior high school models; and personal doubts. From descriptions of their understanding and exercising of leadership, the researcher concluded that teacher leaders had become empowered. The school culture was seen to have a great effect on teacher leaders. The contrasts between a school with a positive culture and another school in disarray were presented. Structures such as summer institutes and release time during the school day were identified as critical for giving teachers the time needed to establish more collaborative working relationships. Once greater trust and understanding were present, teachers were better able to examine their teaching practices more critically. Participants identified mentoring of new members, a continuing role for science facilitators, and central support as necessary for ensuring the sustainability of the changes made during the years of the grant initiative. The researcher concluded that teacher leaders can be a powerful force for bringing about change in schools when provided with training and time during the school day to work with colleagues.

Growth rate regulation of Escherichia coli acetyl coenzyme A carboxylase, which catalyzes the first committed step of lipid biosynthesis.

PubMed Central

Li, S J; Cronan, J E

1993-01-01

Acetyl coenzyme A (CoA) carboxylase catalyzes the synthesis of malonyl-CoA, the first intermediate of fatty acid synthesis. The Escherichia coli enzyme is encoded by four subunits located at three different positions on the E. coli chromosome. The accBC genes lie in a small operon at min 72, whereas accA and accD are located at min 4.3 and 50, respectively. We examined the expression of the genes that encode the E. coli acetyl-CoA carboxylase subunits (accA, accBC, and accD) under a variety of growth conditions by quantitative Northern (RNA) blot analysis. We found a direct correlation between the levels of transcription of the acc genes and the rate of cellular growth. Consistent results were also obtained upon nutritional upshift and downshift experiments and upon dilution of stationary-phase cultures into fresh media. We also determined the 5' end of the accA and accD mRNAs by primer extension and did transcriptional fusion analysis of the previously reported accBC promoter. Several interesting features were found in the promoter regions of these genes, including a bent DNA sequence and an open reading frame within the unusually long leader mRNA of the accBC operon, potential stem-loop structures in the accA and accD mRNA leader regions, and a stretch of GC-rich sequences followed by AT-rich sequences common to all three promoters. In addition, both accA and accD are located in complex gene clusters. For example, the accA promoter was localized within the upstream polC gene (which encodes the DNA polymerase III catalytic subunit), suggesting that additional regulatory mechanisms exist. Images PMID:7678242

Improvement and efficient display of Bacillus thuringiensis toxins on M13 phages and ribosomes.

PubMed

Pacheco, Sabino; Cantón, Emiliano; Zuñiga-Navarrete, Fernando; Pecorari, Frédéric; Bravo, Alejandra; Soberón, Mario

2015-12-01

Bacillus thuringiensis (Bt) produces insecticidal proteins that have been used worldwide in the control of insect-pests in crops and vectors of human diseases. However, different insect species are poorly controlled by the available Bt toxins or have evolved resistance to these toxins. Evolution of Bt toxicity could provide novel toxins to control insect pests. To this aim, efficient display systems to select toxins with increased binding to insect membranes or midgut proteins involved in toxicity are likely to be helpful. Here we describe two display systems, phage display and ribosome display, that allow the efficient display of two non-structurally related Bt toxins, Cry1Ac and Cyt1Aa. Improved display of Cry1Ac and Cyt1Aa on M13 phages was achieved by changing the commonly used peptide leader sequence of the coat pIII-fusion protein, that relies on the Sec translocation pathway, for a peptide leader sequence that relies on the signal recognition particle pathway (SRP) and by using a modified M13 helper phage (Phaberge) that has an amber mutation in its pIII genomic sequence and preferentially assembles using the pIII-fusion protein. Also, both Cry1Ac and Cyt1Aa were efficiently displayed on ribosomes, which could allow the construction of large libraries of variants. Furthermore, Cry1Ac or Cyt1Aa displayed on M13 phages or ribosomes were specifically selected from a mixture of both toxins depending on which antigen was immobilized for binding selection. These improved systems may allow the selection of Cry toxin variants with improved insecticidal activities that could counter insect resistances.

The positive regulatory function of the 5'-proximal open reading frames in GCN4 mRNA can be mimicked by heterologous, short coding sequences.

PubMed Central

Williams, N P; Mueller, P P; Hinnebusch, A G

1988-01-01

Translational control of GCN4 expression in the yeast Saccharomyces cerevisiae is mediated by multiple AUG codons present in the leader of GCN4 mRNA, each of which initiates a short open reading frame of only two or three codons. Upstream AUG codons 3 and 4 are required to repress GCN4 expression in normal growth conditions; AUG codons 1 and 2 are needed to overcome this repression in amino acid starvation conditions. We show that the regulatory function of AUG codons 1 and 2 can be qualitatively mimicked by the AUG codons of two heterologous upstream open reading frames (URFs) containing the initiation regions of the yeast genes PGK and TRP1. These AUG codons inhibit GCN4 expression when present singly in the mRNA leader; however, they stimulate GCN4 expression in derepressing conditions when inserted upstream from AUG codons 3 and 4. This finding supports the idea that AUG codons 1 and 2 function in the control mechanism as translation initiation sites and further suggests that suppression of the inhibitory effects of AUG codons 3 and 4 is a general consequence of the translation of URF 1 and 2 sequences upstream. Several observations suggest that AUG codons 3 and 4 are efficient initiation sites; however, these sequences do not act as positive regulatory elements when placed upstream from URF 1. This result suggests that efficient translation is only one of the important properties of the 5' proximal URFs in GCN4 mRNA. We propose that a second property is the ability to permit reinitiation following termination of translation and that URF 1 is optimized for this regulatory function. Images PMID:3065626

Structures of the peptide-modifying radical SAM enzyme SuiB elucidate the basis of substrate recognition.

PubMed

Davis, Katherine M; Schramma, Kelsey R; Hansen, William A; Bacik, John P; Khare, Sagar D; Seyedsayamdost, Mohammad R; Ando, Nozomi

2017-09-26

Posttranslational modification of ribosomally synthesized peptides provides an elegant means for the production of biologically active molecules known as RiPPs (ribosomally synthesized and posttranslationally modified peptides). Although the leader sequence of the precursor peptide is often required for turnover, the exact mode of recognition by the modifying enzymes remains unclear for many members of this class of natural products. Here, we have used X-ray crystallography and computational modeling to examine the role of the leader peptide in the biosynthesis of a homolog of streptide, a recently identified peptide natural product with an intramolecular lysine-tryptophan cross-link, which is installed by the radical S -adenosylmethionine (SAM) enzyme, StrB. We present crystal structures of SuiB, a close ortholog of StrB, in various forms, including apo SuiB, SAM-bound SuiB, and a complex of SuiB with SAM and its peptide substrate, SuiA. Although the N-terminal domain of SuiB adopts a typical RRE (RiPP recognition element) motif, which has been implicated in precursor peptide recognition, we observe binding of the leader peptide in the catalytic barrel rather than the N-terminal domain. Computational simulations support a mechanism in which the leader peptide guides posttranslational modification by positioning the cross-linking residues of the precursor peptide within the active site. Together the results shed light onto binding of the precursor peptide and the associated conformational changes needed for the formation of the unique carbon-carbon cross-link in the streptide family of natural products.

Positions of Trp Codons in the Leader Peptide-Coding Region of the at Operon Influence Anti-Trap Synthesis and trp Operon Expression in Bacillus licheniformis▿

PubMed Central

Levitin, Anastasia; Yanofsky, Charles

2010-01-01

Tryptophan, phenylalanine, tyrosine, and several other metabolites are all synthesized from a common precursor, chorismic acid. Since tryptophan is a product of an energetically expensive biosynthetic pathway, bacteria have developed sensing mechanisms to downregulate synthesis of the enzymes of tryptophan formation when synthesis of the amino acid is not needed. In Bacillus subtilis and some other Gram-positive bacteria, trp operon expression is regulated by two proteins, TRAP (the tryptophan-activated RNA binding protein) and AT (the anti-TRAP protein). TRAP is activated by bound tryptophan, and AT synthesis is increased upon accumulation of uncharged tRNATrp. Tryptophan-activated TRAP binds to trp operon leader RNA, generating a terminator structure that promotes transcription termination. AT binds to tryptophan-activated TRAP, inhibiting its RNA binding ability. In B. subtilis, AT synthesis is upregulated both transcriptionally and translationally in response to the accumulation of uncharged tRNATrp. In this paper, we focus on explaining the differences in organization and regulatory functions of the at operon's leader peptide-coding region, rtpLP, of B. subtilis and Bacillus licheniformis. Our objective was to correlate the greater growth sensitivity of B. licheniformis to tryptophan starvation with the spacing of the three Trp codons in its at operon leader peptide-coding region. Our findings suggest that the Trp codon location in rtpLP of B. licheniformis is designed to allow a mild charged-tRNATrp deficiency to expose the Shine-Dalgarno sequence and start codon for the AT protein, leading to increased AT synthesis. PMID:20061467

Conserved features of eukaryotic hsp70 genes revealed by comparison with the nucleotide sequence of human hsp70.

PubMed Central

Hunt, C; Morimoto, R I

1985-01-01

We have determined the nucleotide sequence of the human hsp70 gene and 5' flanking region. The hsp70 gene is transcribed as an uninterrupted primary transcript of 2440 nucleotides composed of a 5' noncoding leader sequence of 212 nucleotides, a 3' noncoding region of 242 nucleotides, and a continuous open reading frame of 1986 nucleotides that encodes a protein with predicted molecular mass of 69,800 daltons. Upstream of the 5' terminus are the canonical TATAAA box, the sequence ATTGG that corresponds in the inverted orientation to the CCAAT motif, and the dyad sequence CTGGAAT/ATTCCCG that shares homology in 12 of 14 positions with the consensus transcription regulatory sequence common to Drosophila heat shock genes. Comparison of the predicted amino acid sequences of human hsp70 with the published sequences of Drosophila hsp70 and Escherichia coli dnaK reveals that human hsp70 is 73% identical to Drosophila hsp70 and 47% identical to E. coli dnaK. Surprisingly, the nucleotide sequences of the human and Drosophila genes are 72% identical and human and E. coli genes are 50% identical, which is more highly conserved than necessary given the degeneracy of the genetic code. The lack of accumulated silent nucleotide substitutions leads us to propose that there may be additional information in the nucleotide sequence of the hsp70 gene or the corresponding mRNA that precludes the maximum divergence allowed in the silent codon positions. PMID:3931075

Alteration of hairpin ribozyme specificity utilizing PCR.

PubMed

DeGrandis, P; Hampel, A; Galasinski, S; Borneman, J; Siwkowski, A; Altschuler, M

1994-12-01

We have developed a method by which a researcher can quickly alter the specificity of a trans hairpin ribozyme. Utilizing this PCR method, two oligonucleotides, and any target vector, new ribozyme template sequences can be generated without the synthesis of longer oligonucleotides. We have produced templates with altered specificity for both standard and modified (larger) ribozymes. After transcription, these ribozymes show specific cleavage activity with the new substrate beta-glucuronidase (GUS), and no activity against the original substrate (HIV-1, 5' leader sequence). Utilizing this technique, it is also possible to produce an inactive ribozyme that can be used as an antisense control. Applications of this procedure would provide a rapid and economical system for the assessment of trans ribozyme activity.

Identification and subcellular localization of porcine deltacoronavirus accessory protein NS6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, Puxian; Fang, Liurong; Liu, Xiaorong

Porcine deltacoronavirus (PDCoV) is an emerging swine enteric coronavirus. Accessory proteins are genus-specific for coronavirus, and two putative accessory proteins, NS6 and NS7, are predicted to be encoded by PDCoV; however, this remains to be confirmed experimentally. Here, we identified the leader-body junction sites of NS6 subgenomic RNA (sgRNA) and found that the actual transcription regulatory sequence (TRS) utilized by NS6 is non-canonical and is located upstream of the predicted TRS. Using the purified NS6 from an Escherichia coli expression system, we obtained two anti-NS6 monoclonal antibodies that could detect the predicted NS6 in cells infected with PDCoV or transfectedmore » with NS6-expressing plasmids. Further studies revealed that NS6 is always localized in the cytoplasm of PDCoV-infected cells, mainly co-localizing with the endoplasmic reticulum (ER) and ER-Golgi intermediate compartments, as well as partially with the Golgi apparatus. Together, our results identify the NS6 sgRNA and demonstrate its expression in PDCoV-infected cells. -- Highlights: •The leader-body fusion site of NS6 sgRNA is identified. •NS6 sgRNA uses a non-canonical transcription regulatory sequence (TRS). •NS6 can be expressed in PDCoV-infected cell. •NS6 predominantly localize to the ER complex and ER-Golgi intermediate compartment.« less

Biosynthesis of Lipoic Acid in Arabidopsis: Cloning and Characterization of the cDNA for Lipoic Acid Synthase1

PubMed Central

Yasuno, Rie; Wada, Hajime

1998-01-01

Lipoic acid is a coenzyme that is essential for the activity of enzyme complexes such as those of pyruvate dehydrogenase and glycine decarboxylase. We report here the isolation and characterization of LIP1 cDNA for lipoic acid synthase of Arabidopsis. The Arabidopsis LIP1 cDNA was isolated using an expressed sequence tag homologous to the lipoic acid synthase of Escherichia coli. This cDNA was shown to code for Arabidopsis lipoic acid synthase by its ability to complement a lipA mutant of E. coli defective in lipoic acid synthase. DNA-sequence analysis of the LIP1 cDNA revealed an open reading frame predicting a protein of 374 amino acids. Comparisons of the deduced amino acid sequence with those of E. coli and yeast lipoic acid synthase homologs showed a high degree of sequence similarity and the presence of a leader sequence presumably required for import into the mitochondria. Southern-hybridization analysis suggested that LIP1 is a single-copy gene in Arabidopsis. Western analysis with an antibody against lipoic acid synthase demonstrated that this enzyme is located in the mitochondrial compartment in Arabidopsis cells as a 43-kD polypeptide. PMID:9808738

Molecular characterisation of Atlantic salmon paramyxovirus (ASPV): A novel paramyxovirus associated with proliferative gill inflammation

USGS Publications Warehouse

Falk, K.; Batts, W.N.; Kvellestad, A.; Kurath, G.; Wiik-Nielsen, J.; Winton, J.R.

2008-01-01

Atlantic salmon paramyxovirus (ASPV) was isolated in 1995 from gills of farmed Atlantic salmon suffering from proliferative gill inflammation. The complete genome sequence of ASPV was determined, revealing a genome 16,968 nucleotides in length consisting of six non-overlapping genes coding for the nucleo- (N), phospho- (P), matrix- (M), fusion- (F), haemagglutinin-neuraminidase- (HN) and large polymerase (L) proteins in the order 3???-N-P-M-F-HN-L-5???. The various conserved features related to virus replication found in most paramyxoviruses were also found in ASPV. These include: conserved and complementary leader and trailer sequences, tri-nucleotide intergenic regions and highly conserved transcription start and stop signal sequences. The P gene expression strategy of ASPV was like that of the respiro-, morbilli- and henipaviruses, which express the P and C proteins from the primary transcript and edit a portion of the mRNA to encode V and W proteins. Sequence similarities among various features related to virus replication, pairwise comparisons of all deduced ASPV protein sequences with homologous regions from other members of the family Paramyxoviridae, and phylogenetic analyses of these amino acid sequences suggested that ASPV was a novel member of the sub-family Paramyxovirinae, most closely related to the respiroviruses. ?? 2008 Elsevier B.V. All rights reserved.

QuickProbs 2: Towards rapid construction of high-quality alignments of large protein families

PubMed Central

Gudyś, Adam; Deorowicz, Sebastian

2017-01-01

The ever-increasing size of sequence databases caused by the development of high throughput sequencing, poses to multiple alignment algorithms one of the greatest challenges yet. As we show, well-established techniques employed for increasing alignment quality, i.e., refinement and consistency, are ineffective when large protein families are investigated. We present QuickProbs 2, an algorithm for multiple sequence alignment. Based on probabilistic models, equipped with novel column-oriented refinement and selective consistency, it offers outstanding accuracy. When analysing hundreds of sequences, Quick-Probs 2 is noticeably better than ClustalΩ and MAFFT, the previous leaders for processing numerous protein families. In the case of smaller sets, for which consistency-based methods are the best performing, QuickProbs 2 is also superior to the competitors. Due to low computational requirements of selective consistency and utilization of massively parallel architectures, presented algorithm has similar execution times to ClustalΩ, and is orders of magnitude faster than full consistency approaches, like MSAProbs or PicXAA. All these make QuickProbs 2 an excellent tool for aligning families ranging from few, to hundreds of proteins. PMID:28139687

A novel endo-beta-1,3-glucanase, BGN13.1, involved in the mycoparasitism of Trichoderma harzianum.

PubMed Central

de la Cruz, J; Pintor-Toro, J A; Benítez, T; Llobell, A; Romero, L C

1995-01-01

The mycoparasitic fungus Trichoderma harzianum CECT 2413 produces at least three extracellular beta-1,3-glucanases. The most basic of these extracellular enzymes, named BGN13.1, was expressed when either fungal cell wall polymers or autoclaved mycelia from different fungi were used as the carbon source. BGN13.1 was purified to electrophoretic homogeneity and was biochemically characterized. The enzyme was specific for beta-1,3 linkages and has an endolytic mode of action. A synthetic oligonucleotide primer based on the sequence of an internal peptide was designed to clone the cDNA corresponding to BGN13.1. The deduced amino acid sequence predicted a molecular mass of 78 kDa for the mature protein. Analysis of the amino acid sequence indicates that the enzyme contains three regions, one N-terminal leader sequence; another, nondefined sequence; and one cysteine-rich C-terminal sequence. Sequence comparison shows that this beta-1,3-glucanase, first described for filamentous fungi, belongs to a family different from that of its previously described bacterial, yeast, and plant counterparts. Enzymatic-activity, protein, and mRNA data indicated that bgn13.1 is repressed by glucose and induced by either fungal cell wall polymers or autoclaved yeast cells and mycelia. Finally, experimental evidence showed that the enzyme hydrolyzes yeast and fungal cell walls. PMID:7592488

Purification, characterization and sequence analysis of Omp50,a new porin isolated from Campylobacter jejuni.

PubMed Central

Bolla, J M; Dé, E; Dorez, A; Pagès, J M

2000-01-01

A novel pore-forming protein identified in Campylobacter was purified by ion-exchange chromatography and named Omp50 according to both its molecular mass and its outer membrane localization. We observed a pore-forming ability of Omp50 after re-incorporation into artificial membranes. The protein induced cation-selective channels with major conductance values of 50-60 pS in 1 M NaCl. N-terminal sequencing allowed us to identify the predicted coding sequence Cj1170c from the Campylobacter jejuni genome database as the corresponding gene in the NCTC 11168 genome sequence. The gene, designated omp50, consists of a 1425 bp open reading frame encoding a deduced 453-amino acid protein with a calculated pI of 5.81 and a molecular mass of 51169.2 Da. The protein possessed a 20-amino acid leader sequence. No significant similarity was found between Omp50 and porin protein sequences already determined. Moreover, the protein showed only weak sequence identity with the major outer-membrane protein (MOMP) of Campylobacter, correlating with the absence of antigenic cross-reactivity between these two proteins. Omp50 is expressed in C. jejuni and Campylobacter lari but not in Campylobacter coli. The gene, however, was detected in all three species by PCR. According to its conformation and functional properties, the protein would belong to the family of outer-membrane monomeric porins. PMID:11104668

Transdominant Rev and Protease Mutant Proteins of HIV-SIV as Potential Antiviral Agents in Vitro and in Vivo (AIDS)

DTIC Science & Technology

1993-10-30

hammerhead ribozymes (7-9) and a hairpin ribozyme (10) directed against HIV-l RNA has been shown to confer significant resistance to HIV-I infection...antisense oligodeoxynucleotides (ODN) directed to the Rev Response Element (RRE) and ribozymes that target viral mRNAs. The ribozyme approach, in...particular, has yielded extremely encouraging positive data. We showed that a hairpin ribozyme designed to cleave HIV-1 RNA in the 5’ leader sequence

[Clustered regularly interspaced short palindromic repeats: structure, function and application--a review].

PubMed

Cui, Yujun; Li, Yanjun; Yan, Yanfeng; Yang, Ruifu

2008-11-01

CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats), the basis of spoligotyping technology, can provide prokaryotes with heritable adaptive immunity against phages' invasion. Studies on CRISPR loci and their associated elements, including various CAS (CRISPR-associated) proteins and leader sequences, are still in its infant period. We introduce the brief history', structure, function, bioinformatics research and application of this amazing immunity system in prokaryotic organism for inspiring more scientists to find their interest in this developing topic.

Intramolecular triple helix as a model for regular polyribonucleotide (CAA)(n).

PubMed

Efimov, Alexander V; Spirin, Alexander S

2009-10-09

The regular (CAA)(n) polyribonucleotide, as well as the omega leader sequence containing (CAA)-rich core, have recently been shown to form cooperatively melted and compact structures. In this report, we propose a structural model for the (CAA)(n) sequence in which the polyribonucleotide chain is folded upon itself, so that it forms an intramolecular triple helix. The triple helix is stabilized by hydrogen bonding between bases thus forming coplanar triads, and by stacking interactions between the base triads. A distinctive feature of the proposed triple helix is that it does not contain the canonical double-helix elements. The difference from the known triple helices is that Watson-Crick hydrogen bond pairings do not take place in the interactions between the bases within the base triads.

Coordinate regulation of two cytoplasmic RNA species transcribed from early region 2 of the adenovirus 2 genome.

PubMed Central

Goldenberg, C J; Rosenthal, R; Bhaduri, S; Raskas, H

1981-01-01

Early region 2 (E2) of the adenovirus 2 genome specifies a 72,000-dalton DNA-binding protein that is required for viral DNA replication. Electron microscopy studies have detected two major forms of 20S E2 mRNA, one species with a 5' leader from map position 75 and a second form having a leader from position 72 (Chow et al., J. Mol. Biol. 134:265-303, 1979). Only the species with a leader from position 75 was detected at early times; however, both forms were found at late times. We have analyzed the temporal regulation of E2 expression by documenting mRNA accumulation in the cytoplasm. Kinetic studies of pulse-labeled RNAs demonstrated a peak of E2 cytoplasmic RNa synthesis at 10 to 12 h, coinciding with the time of maximal synthesis of the 72,000-dalton DNA binding protein and viral DNA. To estimate the relative abundances of the two major E2 RNA species at various times during infection, total E2 cytoplasmic and polysomal 20S RNAs were isolated by hybridization-selection with specific DNA probes. The leader sequences in the selected RNAs were then quantitated by further RNA-DNA hybridization. We found that the elevated accumulation rate for E2 cytoplasmic RNA at late times reflected an increase in formation of both major species. Moreover, for all time points examined 66% of the mRNA species had a 5' end from map position 75, and 33% had a 5' terminus from position 72. Continuous labeling experiments provided evidence that both RNA forms have comparable half-lives. The results suggest that the two major species encoded by E2 are regulated in a coordinate fashion late in infection. Images PMID:6894621

Coordinate regulation of two cytoplasmic RNA species transcribed from early region 2 of the adenovirus 2 genome.

PubMed

Goldenberg, C J; Rosenthal, R; Bhaduri, S; Raskas, H

1981-06-01

Early region 2 (E2) of the adenovirus 2 genome specifies a 72,000-dalton DNA-binding protein that is required for viral DNA replication. Electron microscopy studies have detected two major forms of 20S E2 mRNA, one species with a 5' leader from map position 75 and a second form having a leader from position 72 (Chow et al., J. Mol. Biol. 134:265-303, 1979). Only the species with a leader from position 75 was detected at early times; however, both forms were found at late times. We have analyzed the temporal regulation of E2 expression by documenting mRNA accumulation in the cytoplasm. Kinetic studies of pulse-labeled RNAs demonstrated a peak of E2 cytoplasmic RNa synthesis at 10 to 12 h, coinciding with the time of maximal synthesis of the 72,000-dalton DNA binding protein and viral DNA. To estimate the relative abundances of the two major E2 RNA species at various times during infection, total E2 cytoplasmic and polysomal 20S RNAs were isolated by hybridization-selection with specific DNA probes. The leader sequences in the selected RNAs were then quantitated by further RNA-DNA hybridization. We found that the elevated accumulation rate for E2 cytoplasmic RNA at late times reflected an increase in formation of both major species. Moreover, for all time points examined 66% of the mRNA species had a 5' end from map position 75, and 33% had a 5' terminus from position 72. Continuous labeling experiments provided evidence that both RNA forms have comparable half-lives. The results suggest that the two major species encoded by E2 are regulated in a coordinate fashion late in infection.

Trypanosomatidae: a spliced-leader-derived probe specific for the genus Phytomonas.

PubMed

Teixeira, M M; Serrano, M G; Nunes, L R; Campaner, M; Buck, G A; Camargo, E P

1996-12-01

We probed DNA from all trypanosomatid genera by slot blot hybridization with an oligonucleotide (SL3') complementary to a sequence of the Phytomonas spliced-leader or mini-exon RNA. The 19-nucleotide probe target site was previously shown to be highly conserved among a limited number of Phytomonas isolates, but diverges in other kinetoplastid genera. Our examination of 84 isolates of various genera of trypanosomatids showed hybridization of this probe exclusively with isolates from plants or insects which could, by morphological, biochemical, and molecular criteria, be considered to belong to the genus Phytomonas. In contrast, no hybridization was observed with flagellates of the genera Blastocrithidia, Crithidia, Endotrypanum, Herpetomonas, Leptomonas, Leishmania, and Trypanosoma. The method detected DNA quantities as low as 50 ng using either radioactive or nonradioactive probes, and was effective with as few as 10(4) intact flagellates. Together, these results suggest that this probe will serve as a convenient marker for taxonomic and epidemiological studies requiring reliable identification of Phytomonas spp. in plants or in putative insect vectors.

Molecular cloning, structural analysis, and expression in Escherichia coli of a chitinase gene from Enterobacter agglomerans.

PubMed Central

Chernin, L S; De la Fuente, L; Sobolev, V; Haran, S; Vorgias, C E; Oppenheim, A B; Chet, I

1997-01-01

The gene chiA, which codes for endochitinase, was cloned from a soilborne Enterobacter agglomerans. Its complete sequence was determined, and the deduced amino acid sequence of the enzyme designated Chia_Entag yielded an open reading frame coding for 562 amino acids of a 61-kDa precursor protein with a putative leader peptide at its N terminus. The nucleotide and polypeptide sequences of Chia_Entag showed 86.8 and 87.7% identity with the corresponding gene and enzyme, Chia_Serma, of Serratia marcescens, respectively. Homology modeling of Chia_Entag's three-dimensional structure demonstrated that most amino acid substitutions are at solvent-accessible sites. Escherichia coli JM109 carrying the E. agglomerans chiA gene produced and secreted Chia_Entag. The antifungal activity of the secreted endochitinase was demonstrated in vitro by inhibition of Fusarium oxysporum spore germination. The transformed strain inhibited Rhizoctonia solani growth on plates and the root rot disease caused by this fungus in cotton seedlings under greenhouse conditions. PMID:9055404

Mutual coordination strengthens the sense of joint agency in cooperative joint action.

PubMed

Bolt, Nicole K; Poncelet, Evan M; Schultz, Benjamin G; Loehr, Janeen D

2016-11-01

Philosophers have proposed that when people coordinate their actions with others they may experience a sense of joint agency, or shared control over actions and their effects. However, little empirical work has investigated the sense of joint agency. In the current study, pairs coordinated their actions to produce tone sequences and then rated their sense of joint agency on a scale ranging from shared to independent control. People felt more shared than independent control overall, confirming that people experience joint agency during joint action. Furthermore, people felt stronger joint agency when they (a) produced sequences that required mutual coordination compared to sequences in which only one partner had to coordinate with the other, (b) held the role of follower compared to leader, and (c) were better coordinated with their partner. Thus, the strength of joint agency is influenced by the degree to which people mutually coordinate with each other's actions. Copyright © 2016 Elsevier Inc. All rights reserved.

Intrinsic sequence specificity of the Cas1 integrase directs new spacer acquisition

PubMed Central

Rollie, Clare; Schneider, Stefanie; Brinkmann, Anna Sophie; Bolt, Edward L; White, Malcolm F

2015-01-01

The adaptive prokaryotic immune system CRISPR-Cas provides RNA-mediated protection from invading genetic elements. The fundamental basis of the system is the ability to capture small pieces of foreign DNA for incorporation into the genome at the CRISPR locus, a process known as Adaptation, which is dependent on the Cas1 and Cas2 proteins. We demonstrate that Cas1 catalyses an efficient trans-esterification reaction on branched DNA substrates, which represents the reverse- or disintegration reaction. Cas1 from both Escherichia coli and Sulfolobus solfataricus display sequence specific activity, with a clear preference for the nucleotides flanking the integration site at the leader-repeat 1 boundary of the CRISPR locus. Cas2 is not required for this activity and does not influence the specificity. This suggests that the inherent sequence specificity of Cas1 is a major determinant of the adaptation process. DOI: http://dx.doi.org/10.7554/eLife.08716.001 PMID:26284603

Purification of the spliced leader ribonucleoprotein particle from Leptomonas collosoma revealed the existence of an Sm protein in trypanosomes. Cloning the SmE homologue.

PubMed

Goncharov, I; Palfi, Z; Bindereif, A; Michaeli, S

1999-04-30

Trans-splicing in trypanosomes involves the addition of a common spliced leader (SL) sequence, which is derived from a small RNA, the SL RNA, to all mRNA precursors. The SL RNA is present in the cell in the form of a ribonucleoprotein, the SL RNP. Using conventional chromatography and affinity selection with 2'-O-methylated RNA oligonucleotides at high ionic strength, five proteins of 70, 16, 13, 12, and 8 kDa were co-selected with the SL RNA from Leptomonas collosoma, representing the SL RNP core particle. Under conditions of lower ionic strength, additional proteins of 28 and 20 kDa were revealed. On the basis of peptide sequences, the gene coding for a protein with a predicted molecular weight of 11.9 kDa was cloned and identified as homologue of the cis-spliceosomal SmE. The protein carries the Sm motifs 1 and 2 characteristic of Sm antigens that bind to all known cis-spliceosomal uridylic acid-rich small nuclear RNAs (U snRNAs), suggesting the existence of Sm proteins in trypanosomes. This finding is of special interest because trypanosome snRNPs are the only snRNPs examined to date that are not recognized by anti-Sm antibodies. Because of the early divergence of trypanosomes from the eukaryotic lineage, the trypanosome SmE protein represents one of the primordial Sm proteins in nature.

Parainfluenza virus chimeric mini-replicons indicate a novel regulatory element in the leader promoter.

PubMed

Matsumoto, Yusuke; Ohta, Keisuke; Goto, Hideo; Nishio, Machiko

2016-07-01

Gene expression of paramyxoviruses is regulated by genome-encoded cis-acting elements; however, whether all the required elements for viral growth have been identified is not clear. Using a mini-replicon system, it has been shown that human parainfluenza virus type 2 (hPIV2) polymerase can recognize the promoter elements of parainfluenza virus type 5 (PIV5), but reporter activity is lower in this case. We constructed a series of luciferase-encoding chimeric PIV2/5 mini-genomes that are basically hPIV2, but whose leader (le), mRNA start signal and trailer sequence are partially replaced with those of PIV5. Studies of the chimeric PIV2/5 mini-replicons demonstrated that replacement of hPIV2 le with PIV5 le results in remarkably weak luciferase expression. Further mutagenesis identified the responsible region as positions 25-30 of the PIV5 le. Using recombinant hPIV2, the impact of this region on viral life cycles was assessed. Insertion of the mutation at this region facilitated viral growth, genomic replication and mRNA transcription at the early stage of infection, which elicited severe cell damage. In contrast, at the late infection stage it caused a reduction in viral transcription. Here, we identify a novel cis-acting element in the internal region of an le sequence that is involved in the regulation of polymerase, and which contributes to maintaining a balance between viral growth and cytotoxicity.

Genetic identification of the bacteriocins produced by Enterococcus faecium IT62 and evidence that bacteriocin 32 is identical to enterocin IT.

PubMed

Izquierdo, Esther; Cai, Yimin; Marchioni, Eric; Ennahar, Saïd

2009-05-01

Enterococcus faecium IT62, a strain isolated from ryegrass in Japan, produces three bacteriocins (enterocins L50A, L50B, and IT) that have been previously purified and the primary structures of which have been determined by amino acid sequencing (E. Izquierdo, A. Bednarczyk, C. Schaeffer, Y. Cai, E. Marchioni, A. Van Dorsselaer, and S. Ennahar, Antimicrob. Agents Chemother., 52:1917-1923, 2008). Genetic analysis showed that the bacteriocins of E. faecium IT62 are plasmid encoded, but with the structural genes specifying enterocin L50A and enterocin L50B being carried by a plasmid (pTAB1) that is separate from the one (pTIT1) carrying the structural gene of enterocin IT. Sequencing analysis of a 1,475-bp region from pTAB1 identified two consecutive open reading frames corresponding, with the exception of 2 bp, to the genes entL50A and entL50B, encoding EntL50A and EntL50B, respectively. Both bacteriocins are synthesized without N-terminal leader sequences. Genetic analysis of a sequenced 1,380-bp pTIT1 fragment showed that the genes entIT and entIM, encoding enterocin IT and its immunity protein, respectively, were both found in E. faecium VRE200 for bacteriocin 32. Enterocin IT, a 6,390-Da peptide made up of 54 amino acids, has been previously shown to be identical to the C-terminal part of bacteriocin 32, a 7,998-Da bacteriocin produced by E. faecium VRE200 whose structure was deduced from its structural gene (T. Inoue, H. Tomita, and Y. Ike, Antimicrob. Agents Chemother., 50:1202-1212, 2006). By combining the biochemical and genetic data on enterocin IT, it was concluded that bacteriocin 32 is in fact identical to enterocin IT, both being encoded by the same plasmid-borne gene, and that the N-terminal leader peptide for this bacteriocin is 35 amino acids long and not 19 amino acids long as previously reported.

Completion of full length genome sequence of novel avian paramyxovirus strain APMV/Shimane67 isolated from migratory wild geese in Japan.

PubMed

Yamamoto, Eiji; Ito, Toshihiro; Ito, Hiroshi

2016-11-01

The nucleotide sequences of nucleocapsid protein (N); phosphoprotein (P); matrix protein (M); hemagglutinin-neuraminidase (HN); and large polymerase protein (L) genes, 3'-end leader, 5'-end trailer and intergenic regions of the avian paramyxovirus (APMV) strain goose/Shimane/67/2000 (APMV/Shimane67) were determined. Together with previously reported data on fusion protein (F) gene sequence [46], the determination of the genome sequence of APMV/Shimane67 has been completed in this study. The genome of APMV/Shimane67 comprised 16,146 nucleotides in length and contains six genes in the order of 3'-N-P-M-F-HN-L-5'. The features of the APMV/Shimane67 genome (e.g., nucleotide length of whole genome and each of the six genes, and predicted amino acid length of each of the six genes) were distinct from those of other APMV serotypes. Phylogenetic analysis indicated that although APMV/Shimane67 was grouped with APMV-1, -9 and -12, the evolutionary distance between APMV/Shimane67 and these viruses was longer than that observed between intra-serotype viruses. These results show that the genome sequence of APMV/Shimane67 contains specific characteristics and is distinguishable from other types of APMV.

Microsporidia, amitochondrial protists, possess a 70-kDa heat shock protein gene of mitochondrial evolutionary origin.

PubMed

Peyretaillade, E; Broussolle, V; Peyret, P; Méténier, G; Gouy, M; Vivarès, C P

1998-06-01

An intronless gene encoding a protein of 592 amino acid residues with similarity to 70-kDa heat shock proteins (HSP70s) has been cloned and sequenced from the amitochondrial protist Encephalitozoon cuniculi (phylum Microsporidia). Southern blot analyses show the presence of a single gene copy located on chromosome XI. The encoded protein exhibits an N-terminal hydrophobic leader sequence and two motifs shared by proteobacterial and mitochondrially expressed HSP70 homologs. Phylogenetic analysis using maximum likelihood and evolutionary distances place the E. cuniculi sequence in the cluster of mitochondrially expressed HSP70s, with a higher evolutionary rate than those of homologous sequences. Similar results were obtained after cloning a fragment of the homologous gene in the closely related species E. hellem. The presence of a nuclear targeting signal-like sequence supports a role of the Encephalitozoon HSP70 as a molecular chaperone of nuclear proteins. No evidence for cytosolic or endoplasmic reticulum forms of HSP70 was obtained through PCR amplification. These data suggest that Encephalitozoon species have evolved from an ancestor bearing mitochondria, which is in disagreement with the postulated presymbiotic origin of Microsporidia. The specific role and intracellular localization of the mitochondrial HSP70-like protein remain to be elucidated.

Specific DNA binding of the two chicken Deformed family homeodomain proteins, Chox-1.4 and Chox-a.

PubMed Central

Sasaki, H; Yokoyama, E; Kuroiwa, A

1990-01-01

The cDNA clones encoding two chicken Deformed (Dfd) family homeobox containing genes Chox-1.4 and Chox-a were isolated. Comparison of their amino acid sequences with another chicken Dfd family homeodomain protein and with those of mouse homologues revealed that strong homologies are located in the amino terminal regions and around the homeodomains. Although homologies in other regions were relatively low, some short conserved sequences were also identified. E. coli-made full length proteins were purified and used for the production of specific antibodies and for DNA binding studies. The binding profiles of these proteins to the 5'-leader and 5'-upstream sequences of Chox-1.4 and Chox-a coding regions were analyzed by immunoprecipitation and DNase I footprint assays. These two Chox proteins bound to the same sites in the 5'-flanking sequences of their coding regions with various affinities and their binding affinities to each site were nearly the same. The consensus sequences of the high and low affinity binding sites were TAATGA(C/G) and CTAATTTT, respectively. A clustered binding site was identified in the 5'-upstream of the Chox-a gene, suggesting that this clustered binding site works as a cis-regulatory element for auto- and/or cross-regulation of Chox-a gene expression. Images PMID:1970866

Complete sequence of the genome of avian paramyxovirus type 9 and comparison with other paramyxoviruses

PubMed Central

Samuel, Arthur S.; Kumar, Sachin; Madhuri, Subbiah; Collins, Peter L.; Samal, Siba K.

2009-01-01

The complete genome consensus sequence was determined for avian paramyxovirus (APMV) serotype 9 prototype strain PMV-9/domestic Duck/New York/22/78. The genome is 15,438 nucleotides (nt) long and encodes six non-overlapping genes in the order of 3′-N-P/V/W-M-F-HN-L-5′ with intergenic regions of 0–30 nt. The genome length follows the “rule of six” and contains a 55-nt leader sequence at the 3′ end and a 47-nt trailer sequence at the 5′ end. The cleavage site of the F protein is I-R-E-G-R-I↓F, which does not conform to the conventional cleavage site of the ubiquitous cellular protease furin. The virus required exogenous protease for in vitro replication and grew only in a few established cell lines, indicating a restricted host range. Alignment and phylogenetic analysis of the predicted amino acid sequences of APMV-9 proteins with the cognate proteins of viruses of all five genera of family Paramyxoviridae showed that APMV-9 is more closely related to APMV-1 than to other APMVs. The mean death time in embryonated chicken eggs was found to be more than 120 h, indicating APMV-9 to be avirulent for chickens. PMID:19185593

Sequence of the structural gene for granule-bound starch synthase of potato (Solanum tuberosum L.) and evidence for a single point deletion in the amf allele.

PubMed

van der Leij, F R; Visser, R G; Ponstein, A S; Jacobsen, E; Feenstra, W J

1991-08-01

The genomic sequence of the potato gene for starch granule-bound starch synthase (GBSS; "waxy protein") has been determined for the wild-type allele of a monoploid genotype from which an amylose-free (amf) mutant was derived, and for the mutant part of the amf allele. Comparison of the wild-type sequence with a cDNA sequence from the literature and a newly isolated cDNA revealed the presence of 13 introns, the first of which is located in the untranslated leader. The promoter contains a G-box-like sequence. The deduced amino acid sequence of the precursor of GBSS shows a high degree of identity with monocot waxy protein sequences in the region corresponding to the mature form of the enzyme. The transit peptide of 77 amino acids, required for routing of the precursor to the plastids, shows much less identity with the transit peptides of the other waxy preproteins, but resembles the hydropathic distributions of these peptides. Alignment of the amino acid sequences of the four mature starch synthases with the Escherichia coli glgA gene product revealed the presence of at least three conserved boxes; there is no homology with previously proposed starch-binding domains of other enzymes involved in starch metabolism. We report the use of chimeric constructs with wild-type and amf sequences to localize, via complementation experiments, the region of the amf allele in which the mutation resides. Direct sequencing of polymerase chain reaction products confirmed that the amf mutation is a deletion of a single AT basepair in the region coding for the transit peptide.(ABSTRACT TRUNCATED AT 250 WORDS)

A tale of three next generation sequencing platforms: comparison of Ion Torrent, Pacific Biosciences and Illumina MiSeq sequencers.

PubMed

Quail, Michael A; Smith, Miriam; Coupland, Paul; Otto, Thomas D; Harris, Simon R; Connor, Thomas R; Bertoni, Anna; Swerdlow, Harold P; Gu, Yong

2012-07-24

Next generation sequencing (NGS) technology has revolutionized genomic and genetic research. The pace of change in this area is rapid with three major new sequencing platforms having been released in 2011: Ion Torrent's PGM, Pacific Biosciences' RS and the Illumina MiSeq. Here we compare the results obtained with those platforms to the performance of the Illumina HiSeq, the current market leader. In order to compare these platforms, and get sufficient coverage depth to allow meaningful analysis, we have sequenced a set of 4 microbial genomes with mean GC content ranging from 19.3 to 67.7%. Together, these represent a comprehensive range of genome content. Here we report our analysis of that sequence data in terms of coverage distribution, bias, GC distribution, variant detection and accuracy. Sequence generated by Ion Torrent, MiSeq and Pacific Biosciences technologies displays near perfect coverage behaviour on GC-rich, neutral and moderately AT-rich genomes, but a profound bias was observed upon sequencing the extremely AT-rich genome of Plasmodium falciparum on the PGM, resulting in no coverage for approximately 30% of the genome. We analysed the ability to call variants from each platform and found that we could call slightly more variants from Ion Torrent data compared to MiSeq data, but at the expense of a higher false positive rate. Variant calling from Pacific Biosciences data was possible but higher coverage depth was required. Context specific errors were observed in both PGM and MiSeq data, but not in that from the Pacific Biosciences platform. All three fast turnaround sequencers evaluated here were able to generate usable sequence. However there are key differences between the quality of that data and the applications it will support.

Cloning and sequencing of a gene encoding the 69-kDa extracellular chitinase of Janthinobacterium lividum.

PubMed

Gleave, A P; Taylor, R K; Morris, B A; Greenwood, D R

1995-09-15

Janthinobacterium lividum secretes a major 56-kDa chitinase and a minor 69-kDa chitinase. A chitinase gene was defined on a 3-kb fragment of clone pRKT10, by virtue of fluorescent colonies in the presence of 4-methylumbelliferyl-beta-D-N,N',N"-chitotrioside. Nucleotide sequencing revealed an 1998-bp open reading frame with the potential to encode a 69,716-Da protein with amino acid sequences similar to those in other chitinases, suggesting it encodes the minor chitinase (Chi69). Chitinase activity of Escherichia coli (pRKT10) lysates was detected mainly in the periplasmic fraction and immunoblotting detected a 70-kDa protein in this fraction. Chi69 has an N-terminal secretory leader peptide preceding two probable chitin-binding domains and a catalytic domain. These functional domains are separated by linker regions of proline-threonine repeats. Amino acid sequencing of cyanogen bromide cleavage-derived peptides from the major 56-kDa chitinase suggested that Chi69 may be a precursor of Chi56. In addition, an N-terminally truncated version of Chi69 retained chitinase activity as expected if in vivo processing of Chi69 generates Chi56.

Enterocin 96, a Novel Class II Bacteriocin Produced by Enterococcus faecalis WHE 96, Isolated from Munster Cheese▿

PubMed Central

Izquierdo, Esther; Wagner, Camille; Marchioni, Eric; Aoude-Werner, Dalal; Ennahar, Saïd

2009-01-01

Enterococcus faecalis WHE 96, a strain isolated from soft cheese based on its anti-Listeria activity, produced a 5,494-Da bacteriocin that was purified to homogeneity by ultrafiltration and cation-exchange and reversed-phase chromatographies. The amino acid sequence of this bacteriocin, named enterocin 96, was determined by Edman degradation, and its structural gene was sequenced, revealing a double-glycine leader peptide. After a comparison with other bacteriocins, it was shown that enterocin 96 was a new class II bacteriocin that showed very little similarity with known structures. Enterocin 96 was indeed a new bacteriocin belonging to class II bacteriocins. The activity spectrum of enterocin 96 covered a wide range of bacteria, with strong activity against most gram-positive strains but very little or no activity against gram-negative strains. PMID:19411428

Enterocin 96, a novel class II bacteriocin produced by Enterococcus faecalis WHE 96, isolated from Munster cheese.

PubMed

Izquierdo, Esther; Wagner, Camille; Marchioni, Eric; Aoude-Werner, Dalal; Ennahar, Saïd

2009-07-01

Enterococcus faecalis WHE 96, a strain isolated from soft cheese based on its anti-Listeria activity, produced a 5,494-Da bacteriocin that was purified to homogeneity by ultrafiltration and cation-exchange and reversed-phase chromatographies. The amino acid sequence of this bacteriocin, named enterocin 96, was determined by Edman degradation, and its structural gene was sequenced, revealing a double-glycine leader peptide. After a comparison with other bacteriocins, it was shown that enterocin 96 was a new class II bacteriocin that showed very little similarity with known structures. Enterocin 96 was indeed a new bacteriocin belonging to class II bacteriocins. The activity spectrum of enterocin 96 covered a wide range of bacteria, with strong activity against most gram-positive strains but very little or no activity against gram-negative strains.

System Engineering Analysis For Improved Scout Business Information Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Slyke, D. A.

The project uses system engineering principles to address the need of Boy Scout leaders for an integrated system to facilitate advancement and awards records, leader training and planning for meetings and activities. Existing products to address needs of Scout leaders and relevant stakeholders function to support record keeping and some communication functions but opportunity exists for a better system to fully integrate these functions with training delivery and recording, activity planning along with feedback and information gathering from stakeholders. Key stakeholders for the sytem include Scouts and their families, leaders, training providers, sellers of supplies and awards, content generators andmore » facilities that serve Scout activities. Key performance parameters for the system are protection of personal information, availability of current information, information accuracy and information content that has depth. Implementation concepts considered for the system include (1) owned and operated by Boy Scouts of America, (2) Contracted out to a vendor (3) distributed system that functions with BSA managed interfaces. The selected concept is to contract out to a vendor to maximize the likelihood of successful integration and take advantage of the best technology. Development of requirements considers three key use cases (1) System facilitates planning a hike with training needed satisfied in advance and advancement recording real time (2) Scheduling and documenting in-person training, (3) Family interested in Scouting receives information and can request follow-up. Non-functional requirements are analyzed with the Quality Function Deployment tool. Requirement addressing frequency of backup, compatibility with legacy and new technology, language support, software update are developed to address system reliability and intuitive interface. System functions analyzed include update of activity database, maintenance of advancement status, archive of documents, and monitoring of content that is accessible. The study examines risks associated with information security, technological change and continued popularity of Scouting. Mitigation is based on system functions that are defined. The approach to developing an improved system for facilitating Boy Scout leader functions was iterative with insights into capabilities coming in the course of working through the used cases and sequence diagrams.« less

How type II CRISPR-Cas establish immunity through Cas1-Cas2-mediated spacer integration.

PubMed

Xiao, Yibei; Ng, Sherwin; Nam, Ki Hyun; Ke, Ailong

2017-10-05

CRISPR (clustered regularly interspaced short palindromic repeats) and the nearby Cas (CRISPR-associated) operon establish an RNA-based adaptive immunity system in prokaryotes. Molecular memory is created when a short foreign DNA-derived prespacer is integrated into the CRISPR array as a new spacer. Whereas the RNA-guided CRISPR interference mechanism varies widely among CRISPR-Cas systems, the spacer integration mechanism is essentially identical. The conserved Cas1 and Cas2 proteins form an integrase complex consisting of two distal Cas1 dimers bridged by a Cas2 dimer. The prespacer is bound by Cas1-Cas2 as a dual-forked DNA, and the terminal 3'-OH of each 3' overhang serves as an attacking nucleophile during integration. The prespacer is preferentially integrated into the leader-proximal region of the CRISPR array, guided by the leader sequence and a pair of inverted repeats inside the CRISPR repeat. Spacer integration in the well-studied Escherichia coli type I-E CRISPR system also relies on the bacterial integration host factor. In type II-A CRISPR, however, Cas1-Cas2 alone integrates spacers efficiently in vitro; other Cas proteins (such as Cas9 and Csn2) have accessory roles in the biogenesis phase of prespacers. Here we present four structural snapshots from the type II-A system of Enterococcus faecalis Cas1 and Cas2 during spacer integration. Enterococcus faecalis Cas1-Cas2 selectively binds to a splayed 30-base-pair prespacer bearing 4-nucleotide 3' overhangs. Three molecular events take place upon encountering a target: first, the Cas1-Cas2-prespacer complex searches for half-sites stochastically, then it preferentially interacts with the leader-side CRISPR repeat, and finally, it catalyses a nucleophilic attack that connects one strand of the leader-proximal repeat to the prespacer 3' overhang. Recognition of the spacer half-site requires DNA bending and leads to full integration. We derive a mechanistic framework to explain the stepwise spacer integration process and the leader-proximal preference.

How Type II CRISPR-Cas establish immunity through Cas1-Cas2 mediated spacer integration

PubMed Central

Xiao, Yibei; Ng, Sherwin; Nam, Ki Hyun; Ke, Ailong

2017-01-01

CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and the nearby cas (CRISPR-associated) operon establish an RNA-based adaptive immunity system in prokaryotes1–5. Molecular memory is created when a short foreign DNA-derived prespacer is integrated into the CRISPR array as a new spacer6–9. Whereas the RNA-guided CRISPR interference mechanism varies widely among CRISPR-Cas systems, the spacer integration mechanism is essentially identical7–9. The conserved Cas1 and Cas2 proteins form an integrase complex consisting two distal Cas1 dimers bridged by a Cas2 dimer in the middle6,10. The prespacer is bound by Cas1-Cas2 as a dual forked DNA, and the terminal 3′-OH of each 3′-overhang serves as an attacking nucleophile during integration11–14. Importantly, the prespacer is preferentially integrated into the leader-proximal region of the CRISPR array1,7,10,15, guided by the leader sequence and a pair of inverted repeats (IRs) inside the CRISPR repeat7,15–20. Spacer integration in the most well-studied Escherichia coli Type I-E CRISPR system further relies on the bacterial Integration Host Factor (IHF)21,22. In Type II-A CRISPR, however, Cas1-Cas2 alone integrates spacer efficiently in vitro18; other Cas proteins (Cas9 and Csn2) play accessory roles in prespacer biogenesis17,23. Focusing on the Enterococcus faecalis Type II-A system24, here we report four structure snapshots of Cas1-Cas2 during spacer integration. EfaCas1-Cas2 selectively binds to a splayed 30-bp prespacer bearing 4-nt 3′-overhangs. Three molecular events take place upon encountering a target: Cas1-Cas2/prespacer first searches for half-sites stochastically, then preferentially interacts with the leader-side CRISPR repeat and catalyzes a nucleophilic attack that connects one strand of the leader-proximal repeat to the prespacer 3′-overhang. Recognition of the spacer half-site requires DNA bending and leads to full integration. We derive a mechanistic framework explaining the stepwise spacer integration process and the leader-proximal preference. PMID:28869593

Comparative Genomic and Transcriptomic Characterization of the Toxigenic Marine Dinoflagellate Alexandrium ostenfeldii

PubMed Central

Jaeckisch, Nina; Yang, Ines; Wohlrab, Sylke; Glöckner, Gernot; Kroymann, Juergen; Vogel, Heiko; Cembella, Allan; John, Uwe

2011-01-01

Many dinoflagellate species are notorious for the toxins they produce and ecological and human health consequences associated with harmful algal blooms (HABs). Dinoflagellates are particularly refractory to genomic analysis due to the enormous genome size, lack of knowledge about their DNA composition and structure, and peculiarities of gene regulation, such as spliced leader (SL) trans-splicing and mRNA transposition mechanisms. Alexandrium ostenfeldii is known to produce macrocyclic imine toxins, described as spirolides. We characterized the genome of A. ostenfeldii using a combination of transcriptomic data and random genomic clones for comparison with other dinoflagellates, particularly Alexandrium species. Examination of SL sequences revealed similar features as in other dinoflagellates, including Alexandrium species. SL sequences in decay indicate frequent retro-transposition of mRNA species. This probably contributes to overall genome complexity by generating additional gene copies. Sequencing of several thousand fosmid and bacterial artificial chromosome (BAC) ends yielded a wealth of simple repeats and tandemly repeated longer sequence stretches which we estimated to comprise more than half of the whole genome. Surprisingly, the repeats comprise a very limited set of 79–97 bp sequences; in part the genome is thus a relatively uniform sequence space interrupted by coding sequences. Our genomic sequence survey (GSS) represents the largest genomic data set of a dinoflagellate to date. Alexandrium ostenfeldii is a typical dinoflagellate with respect to its transcriptome and mRNA transposition but demonstrates Alexandrium-like stop codon usage. The large portion of repetitive sequences and the organization within the genome is in agreement with several other studies on dinoflagellates using different approaches. It remains to be determined whether this unusual composition is directly correlated to the exceptionally genome organization of dinoflagellates with a low amount of histones and histone-like proteins. PMID:22164224

Positive recoil leader in rocket-triggered and tower-initiated lightning flashes as observed by high speed video camera

NASA Astrophysics Data System (ADS)

Qie, X.; Pu, Y.; Jiang, R.; Liu, M.; Sun, Z.

2017-12-01

Positive recoil leader was observed in both rocket-triggered and tower lightning flashes. The similar processes are observed in all the cases: an initial weakening dart leader propagated downward from the cloud with weak luminosity and terminated finally before reaching the ground. Then the bidirectional leaders started and propagated in the preexisting and decaying channel below the terminated downward dart leader, and the luminosity of the bileader ends was asymmetrical, but both with its tip being the weakest. The upward positive leader end started earlier and fast than the downward negative leader end. The bidirectional leader developed with the positive leader moving upward, along the decayed downward negative leader channel, and the negative leader downward, along the remnants of the channel created by the previous stroke or ICC, and, hence, could be viewed as a kind of recoil leader. However, the polarity of this recoil leader is contrary to the traditional recoil leader with negative leader end retrogressing along an existing positive leader channel. The bidirectional leaders observed herein are new as they are excited by a decayed negative leader with in the preexisting discharge channel, unlike other bidirectional leaders, e.g., the electric breakdown in virgin air or traditional recoil processes formed in a decayed positive leader channel.

CD94-NKG2A recognition of human leukocyte antigen (HLA)-E bound to an HLA class I leader sequence.

PubMed

Petrie, Emma J; Clements, Craig S; Lin, Jie; Sullivan, Lucy C; Johnson, Darryl; Huyton, Trevor; Heroux, Annie; Hoare, Hilary L; Beddoe, Travis; Reid, Hugh H; Wilce, Matthew C J; Brooks, Andrew G; Rossjohn, Jamie

2008-03-17

The recognition of human leukocyte antigen (HLA)-E by the heterodimeric CD94-NKG2 natural killer (NK) receptor family is a central innate mechanism by which NK cells monitor the expression of other HLA molecules, yet the structural basis of this highly specific interaction is unclear. Here, we describe the crystal structure of CD94-NKG2A in complex with HLA-E bound to a peptide derived from the leader sequence of HLA-G. The CD94 subunit dominated the interaction with HLA-E, whereas the NKG2A subunit was more peripheral to the interface. Moreover, the invariant CD94 subunit dominated the peptide-mediated contacts, albeit with poor surface and chemical complementarity. This unusual binding mode was consistent with mutagenesis data at the CD94-NKG2A-HLA-E interface. There were few conformational changes in either CD94-NKG2A or HLA-E upon ligation, and such a "lock and key" interaction is typical of innate receptor-ligand interactions. Nevertheless, the structure also provided insight into how this interaction can be modulated by subtle changes in the peptide ligand or by the pairing of CD94 with other members of the NKG2 family. Differences in the docking strategies used by the NKG2D and CD94-NKG2A receptors provided a basis for understanding the promiscuous nature of ligand recognition by NKG2D compared with the fidelity of the CD94-NKG2 receptors.

CD94-NKG2A recognition of human leukocyte antigen (HLA)-E bound to an HLA class I leader sequence

PubMed Central

Petrie, Emma J.; Clements, Craig S.; Lin, Jie; Sullivan, Lucy C.; Johnson, Darryl; Huyton, Trevor; Heroux, Annie; Hoare, Hilary L.; Beddoe, Travis; Reid, Hugh H.; Wilce, Matthew C.J.; Brooks, Andrew G.; Rossjohn, Jamie

2008-01-01

The recognition of human leukocyte antigen (HLA)-E by the heterodimeric CD94-NKG2 natural killer (NK) receptor family is a central innate mechanism by which NK cells monitor the expression of other HLA molecules, yet the structural basis of this highly specific interaction is unclear. Here, we describe the crystal structure of CD94-NKG2A in complex with HLA-E bound to a peptide derived from the leader sequence of HLA-G. The CD94 subunit dominated the interaction with HLA-E, whereas the NKG2A subunit was more peripheral to the interface. Moreover, the invariant CD94 subunit dominated the peptide-mediated contacts, albeit with poor surface and chemical complementarity. This unusual binding mode was consistent with mutagenesis data at the CD94-NKG2A–HLA-E interface. There were few conformational changes in either CD94-NKG2A or HLA-E upon ligation, and such a “lock and key” interaction is typical of innate receptor–ligand interactions. Nevertheless, the structure also provided insight into how this interaction can be modulated by subtle changes in the peptide ligand or by the pairing of CD94 with other members of the NKG2 family. Differences in the docking strategies used by the NKG2D and CD94-NKG2A receptors provided a basis for understanding the promiscuous nature of ligand recognition by NKG2D compared with the fidelity of the CD94-NKG2 receptors. PMID:18332182

Expression of the recombinant bacterial outer surface protein A in tobacco chloroplasts leads to thylakoid localization and loss of photosynthesis.

PubMed

Hennig, Anna; Bonfig, Katharina; Roitsch, Thomas; Warzecha, Heribert

2007-11-01

Bacterial lipoproteins play crucial roles in host-pathogen interactions and pathogenesis and are important targets for the immune system. A prominent example is the outer surface protein A (OspA) of Borrelia burgdorferi, which has been efficiently used as a vaccine for the prevention of Lyme disease. In a previous study, OspA could be produced in tobacco chloroplasts in a lipidated and immunogenic form. To further explore the potential of chloroplasts for the production of bacterial lipoproteins, the role of the N-terminal leader sequence was investigated. The amount of recombinant OspA could be increased up to ten-fold by the variation of the insertion site in the chloroplast genome. Analysis of OspA mutants revealed that replacement of the invariant cysteine residue as well as deletion of the leader sequence abolishes palmitolyation of OspA. Also, decoration of OspA with an N-terminal eukaryotic lipidation motif does not lead to palmitoylation in chloroplasts. Strikingly, the bacterial signal peptide of OspA efficiently targets the protein to thylakoids, and causes a mutant phenotype. Plants accumulating OspA at 10% total soluble protein could not grow without exogenously supplied sugars and rapidly died after transfer to soil under greenhouse conditions. The plants were found to be strongly affected in photosystem II, as revealed by the analyses of temporal and spatial dynamics of photosynthetic activity by chlorophyll fluorescence imaging. Thus, overexpression of OspA in chloroplasts is limited by its concentration-dependent interference with essential functions of chloroplastic membranes required for primary metabolism.

Narcissistic leaders: An asset or a liability? Leader visibility, follower responses, and group-level absenteeism.

PubMed

Nevicka, Barbara; Van Vianen, Annelies E M; De Hoogh, Annebel H B; Voorn, Bart C M

2018-03-19

Although narcissists often emerge as leaders, research has thus far shown inconsistent results on the relationship between leader narcissism and effectiveness in the eyes of followers. Here we draw on leader distance theory (Shamir, 1995) and implicit leader theory (Lord & Maher, 1991) to propose that followers' assessment of a narcissistic leader and followers' overall job attitudes depend on the leader's visibility to the followers. The more opportunities followers have to observe narcissistic leaders the more they will experience these leaders' toxic behavior (e.g., exploitativeness) and the less they will perceive the leader as effective. To test our hypotheses we collected multisource, longitudinal data from 175 retail stores and obtained subjective (followers' perceptions of leader effectiveness and their overall job attitudes) as well as objective (leaders' organizational experience at time of hire, employee absenteeism trends) indices of leader functionality. Results showed that narcissistic leaders had less organizational experience at the time they were hired. Moreover, when followers had fewer opportunities to observe their leader, leader narcissism was positively related to perceived leadership effectiveness and job attitudes. However, when followers had more opportunity to observe their leader, the positive relationship disappeared. Finally, leader narcissism was neither positively nor negatively associated with absenteeism, whereas absenteeism declined over time under non-narcissistic leaders. These findings advance our knowledge of how followers respond to narcissistic leaders and how these leaders function in organizational settings where they have legitimate positions of power. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

DIFFERENTIATION OF SCHISTOSOMA HAEMATOBIUM FROM RELATED SCHISTOSOMES BY PCR AMPLIFYING AN INTER-REPEAT SEQUENCE

PubMed Central

ABBASI, IBRAHIM; KING, CHARLES H.; STURROCK, ROBERT F.; KARIUKI, CURTIS; MUCHIRI, ERIC; HAMBURGER, JOSEPH

2008-01-01

Schistosoma haematobium infects nearly 150 million people, primarily in Africa, and is transmitted by select species of local bulinid snails. These snails can host other related trematode species as well, so that effective detection and monitoring of snails infected with S. haematobium requires a successful differentiation between S. haematobium and any closely related schistosome species. To enable differential detection of S. haematobium DNA by simple polymerase chain reaction (PCR), we designed and tested primer pairs from numerous newly identified Schistosoma DNA repeat sequences. However, all pairs tested were found unsuitable for this purpose. Differentiation of S. haematobium from S. bovis, S. mattheei, S. curassoni, and S. intercalatum (but not from S. margrebowiei) was ultimately accomplished by PCR using one primer from a newly identified repeat, Sh110, and a second primer from a known schistosomal splice-leader sequence. For evaluation of residual S. haematobium transmission after control interventions, this differentiation tool will enable accurate monitoring of infected snails in areas where S. haematobium is sympatric with the most prevalent other schistosome species. PMID:17488921

Search for 5'-leader regulatory RNA structures based on gene annotation aided by the RiboGap database.

PubMed

Naghdi, Mohammad Reza; Smail, Katia; Wang, Joy X; Wade, Fallou; Breaker, Ronald R; Perreault, Jonathan

2017-03-15

The discovery of noncoding RNAs (ncRNAs) and their importance for gene regulation led us to develop bioinformatics tools to pursue the discovery of novel ncRNAs. Finding ncRNAs de novo is challenging, first due to the difficulty of retrieving large numbers of sequences for given gene activities, and second due to exponential demands on calculation needed for comparative genomics on a large scale. Recently, several tools for the prediction of conserved RNA secondary structure were developed, but many of them are not designed to uncover new ncRNAs, or are too slow for conducting analyses on a large scale. Here we present various approaches using the database RiboGap as a primary tool for finding known ncRNAs and for uncovering simple sequence motifs with regulatory roles. This database also can be used to easily extract intergenic sequences of eubacteria and archaea to find conserved RNA structures upstream of given genes. We also show how to extend analysis further to choose the best candidate ncRNAs for experimental validation. Copyright © 2017 Elsevier Inc. All rights reserved.

An upstream open reading frame represses expression of Lc, a member of the R/B family of maize transcriptional activators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Damiani, R.D. Jr.; Wessler, S.R.

1993-09-01

The R/B genes of maize encode a family of basic helix-loop-helix proteins that determine where and when the anthocyanin-pigment pathway will be expressed in the plant. Previous studies showed that allelic diversity among family members reflects differences in gene expression, specifically in transcription initiation. The authors present evidence that the R gene Lc is under translational control. They demonstrate that the 235-nt transcript leader of Lc represses expression 25- to 30-fold in an in vivo assay. Repression is mediated by the presence in cis of a 38-codon upstream open reading frame. Furthermore, the coding capacity of the upstream open readingmore » frame influences the magnitude of repression. It is proposed that translational control does not contribute to tissue specificity but prevents overexpression of the Lc protein. The diversity of promoter and 5' untranslated leader sequences among the R/B genes provides an opportunity to study the coevolution of transcriptional and translational mechanisms of gene regulation. 36 refs., 5 figs.« less

Advancing mission in the marketplace. Integrated strategic planning and budgeting helps a system remain accountable.

PubMed

Smessaert, A H

1992-10-01

In the late 1980s Holy Cross Health System (HCHS), South Bend, IN, began to implement a revised strategic planning and budgeting process to effectively link the system's mission with its day-to-day operations. Leaders wanted a process that would help system employees internalize and act on the four major elements articulated in the HCHS mission statement: fidelity, excellence, empowerment, and stewardship. Representatives from mission, strategic planning, and finance from the corporate office and subsidiaries examined planning and budgeting methods. From the beginning, HCHS leaders decided that the process should be implemented gradually, with each step focusing on refining methodology and improving mission integration. As the process evolved. HCHS developed a sequence in which planning preceded budgeting. The system also developed a variety of educational and collaborative initiatives to help system employees adapt to the organization's change of direction. One critical aspect of HCHS's ongoing education is an ethical reflection process that helps participants balance ethical considerations by viewing an issue from three perspectives: social vision, multiple responsibility, and self-interest.

Illuminating choices for library prep: a comparison of library preparation methods for whole genome sequencing of Cryptococcus neoformans using Illumina HiSeq.

PubMed

Rhodes, Johanna; Beale, Mathew A; Fisher, Matthew C

2014-01-01

The industry of next-generation sequencing is constantly evolving, with novel library preparation methods and new sequencing machines being released by the major sequencing technology companies annually. The Illumina TruSeq v2 library preparation method was the most widely used kit and the market leader; however, it has now been discontinued, and in 2013 was replaced by the TruSeq Nano and TruSeq PCR-free methods, leaving a gap in knowledge regarding which is the most appropriate library preparation method to use. Here, we used isolates from the pathogenic fungi Cryptococcus neoformans var. grubii and sequenced them using the existing TruSeq DNA v2 kit (Illumina), along with two new kits: the TruSeq Nano DNA kit (Illumina) and the NEBNext Ultra DNA kit (New England Biolabs) to provide a comparison. Compared to the original TruSeq DNA v2 kit, both newer kits gave equivalent or better sequencing data, with increased coverage. When comparing the two newer kits, we found little difference in cost and workflow, with the NEBNext Ultra both slightly cheaper and faster than the TruSeq Nano. However, the quality of data generated using the TruSeq Nano DNA kit was superior due to higher coverage at regions of low GC content, and more SNPs identified. Researchers should therefore evaluate their resources and the type of application (and hence data quality) being considered when ultimately deciding on which library prep method to use.

The impact of previous leaders on the evaluation of new leaders: an alternative to prototype matching.

PubMed

Ritter, Barbara A; Lord, Robert G

2007-11-01

In 2 studies, this research demonstrated the existence of leader transference, a cognitive process whereby mental representations of previous leaders are activated and used for evaluation when new, similar leaders are encountered. The 1st study demonstrated that exposure to a new leader who was similar to a past leader led to erroneous generalization of leader characteristics and associated underlying attributions. The 2nd study showed that expectations of just treatment and abuse were also subject to transfer from old to new, similar leaders, although positive and negative affective responses were not. Results suggested that individuals exposed to a leader who was not reminiscent of an old leader were more likely to use a general leader prototype to form leader expectations, whereas individuals exposed to a leader who was similar to an old leader activated a significant other mental representation for use in making judgments. These results have implications for individual- and relational-level processes as characterized by implicit leadership theory and leader-member exchange theory as well as macro theories of leader succession and organizational culture change. (c) 2007 APA

Transcriptome de novo assembly sequencing and analysis of the toxic dinoflagellate Alexandrium catenella using the Illumina platform.

PubMed

Zhang, Shu; Sui, Zhenghong; Chang, Lianpeng; Kang, Kyoungho; Ma, Jinhua; Kong, Fanna; Zhou, Wei; Wang, Jinguo; Guo, Liliang; Geng, Huili; Zhong, Jie; Ma, Qingxia

2014-03-10

In this article, high-throughput de novo transcriptomic sequencing was performed in Alexandrium catenella, which provided the first view of the gene repertoire in this dinoflagellate based on next-generation sequencing (NGS) technologies. A total of 118,304 unigenes were identified with an average length of 673bp (base pair). Of these unigenes, 77,936 (65.9%) were annotated with known proteins based on sequence similarities, among which 24,149 and 22,956 unigenes were assigned to gene ontology categories (GO) and clusters of orthologous groups (COGs), respectively. Furthermore, 16,467 unigenes were mapped onto 322 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG). We also detected 1143 simple sequence repeats (SSRs), in which the tri-nucleotide repeat motif (69.3%) was the most abundant. The genetic facts and significance derived from the transcriptome dataset were suggested and discussed. All four core nucleosomal histones and linker histones were detected, in addition to the unigenes involved in histone modifications.190 unigenes were identified as being involved in the endocytosis pathway, and clathrin-dependent endocytosis was suggested to play a role in the heterotrophy of A. catenella. A conserved 22-nt spliced leader (SL) was identified in 21 unigenes which suggested the existence of trans-splicing processing of mRNA in A. catenella. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Molecular identification and characterization of clustered regularly interspaced short palindromic repeats (CRISPRs) in a urease-positive thermophilic Campylobacter sp. (UPTC).

PubMed

Tasaki, E; Hirayama, J; Tazumi, A; Hayashi, K; Hara, Y; Ueno, H; Moore, J E; Millar, B C; Matsuda, M

2012-02-01

Novel clustered regularly-interspaced short palindromic repeats (CRISPRs) locus [7,500 base pairs (bp) in length] occurred in the urease-positive thermophilic Campylobacter (UPTC) Japanese isolate, CF89-12. The 7,500 bp gene loci consisted of the 5'-methylaminomethyl-2-thiouridylate methyltransferase gene, putative (P) CRISPR associated (p-Cas), putative open reading frames, Cas1 and Cas2, leader sequence region (146 bp), 12 CRISPRs consensus sequence repeats (each 36 bp) separated by a non-repetitive unique spacer region of similar length (26-31 bp) and the phosphatidyl glycerophosphatase A gene. When the CRISPRs loci in the UPTC CF89-12 and five C. jejuni isolates were compared with one another, these six isolates contained p-Cas, Cas1 and Cas2 within the loci. Four to 12 CRISPRs consensus sequence repeats separated by a non-repetitive unique spacer region occurred in six isolates and the nucleotide sequences of those repeats gave approximately 92-100% similarity with each other. However, no sequence similarity occurred in the unique spacer regions among these isolates. The putative σ(70) transcriptional promoter and the hypothetical ρ-independent terminator structures for the CRISPRs and Cas were detected. No in vivo transcription of p-Cas, Cas1 and Cas2 was confirmed in the UPTC cells.

Determination of the complete genomic sequence and analysis of the gene products of the virus of Spring Viremia of Carp, a fish rhabdovirus.

PubMed

Hoffmann, Bernd; Schütze, Heike; Mettenleiter, Thomas C

2002-03-20

The complete genome of spring viremia of carp virus (SVCV) was cloned and the sequence of 11019 nucleotides was determined. It contains five open reading frames (ORF's) encoding for the nucleoprotein N; phosphoprotein P; matrix protein M; glycoprotein G; and the viral RNA dependent RNA polymerase L. Genes are organised in the order typical for rhabdoviruses: 3'-N-P-M-G-L-5'. The short leader and trailer regions of SVCV exhibit inverse complementarity and are similar to the respective 3' and 5' ends of the genome of vesicular stomatitis virus. To verify the predicted open reading frames proteins were expressed in bacteria and analysed with a polyclonal anti-SVCV serum. Furthermore, monospecific antisera against the distinct viral proteins were generated. Comparison of genome and protein confirm the assignment of SVCV to the genus Vesiculovirus.

The cDNA sequence of a neutral horseradish peroxidase.

PubMed

Bartonek-Roxå, E; Eriksson, H; Mattiasson, B

1991-02-16

A cDNA clone encoding a horseradish (Armoracia rusticana) peroxidase has been isolated and characterized. The cDNA contains 1378 nucleotides excluding the poly(A) tail and the deduced protein contains 327 amino acids which includes a 28 amino acid leader sequence. The predicted amino acid sequence is nine amino acids shorter than the major isoenzyme belonging to the horseradish peroxidase C group (HRP-C) and the sequence shows 53.7% identity with this isoenzyme. The described clone encodes nine cysteines of which eight correspond well with the cysteines found in HRP-C. Five potential N-glycosylation sites with the general sequence Asn-X-Thr/Ser are present in the deduced sequence. Compared to the earlier described HRP-C this is three glycosylation sites less. The shorter sequence and fewer N-glycosylation sites give the native isoenzyme a molecular weight of several thousands less than the horseradish peroxidase C isoenzymes. Comparison with the net charge value of HRP-C indicates that the described cDNA clone encodes a peroxidase which has either the same or a slightly less basic pI value, depending on whether the encoded protein is N-terminally blocked or not. This excludes the possibility that HRP-n could belong to either the HRP-A, -D or -E groups. The low sequence identity (53.7%) with HRP-C indicates that the described clone does not belong to the HRP-C isoenzyme group and comparison of the total amino acid composition with the HRP-B group does not place the described clone within this isoenzyme group. Our conclusion is that the described cDNA clone encodes a neutral horseradish peroxidase which belongs to a new, not earlier described, horseradish peroxidase group.

Fine tangled pili expressed by Haemophilus ducreyi are a novel class of pili.

PubMed Central

Brentjens, R J; Ketterer, M; Apicella, M A; Spinola, S M

1996-01-01

Haemophilus ducreyi synthesizes fine, tangled pili composed predominantly of a protein whose apparent molecular weight is 24,000 (24K). A hybridoma, 2D8, produced a monoclonal antibody (MAb) that bound to a 24K protein in H. ducreyi strains isolated from diverse geographic locations. A lambda gt11 H. ducreyi library was screened with MAb 2D8. A 3.5-kb chromosomal insert from one reactive plaque was amplified and ligated into the pCRII vector. The recombinant plasmid, designated pHD24, expressed a 24K protein in Escherichia coli INV alpha F that bound MAb 2D8. The coding sequence of the 24K gene was localized by exonuclease III digestion. The insert contained a 570-bp open reading frame, designated ftpA (fine, tangled pili). Translation of ftpA predicted a polypeptide with a molecular weight of 21.1K. The predicted N-terminal amino acid sequence of the polypeptide encoded by ftpA was identical to the N-terminal amino acid sequence of purified pilin and lacked a cleavable signal sequence. Primer extension analysis of ftpA confirmed the lack of a leader peptide. The predicted amino acid sequence lacked homology to known pilin sequences but shared homology with the sequences of E. coli Dps and Treponema pallidum antigen TpF1 or 4D, proteins which associate to form ordered rings. An isogenic pilin mutant, H. ducreyi 35000ftpA::mTn3(Cm), was constructed by shuttle mutagenesis and did not contain pili when examined by electron microscopy. We conclude that H. ducreyi synthesizes fine, tangled pili that are composed of a unique major subunit, which may be exported by a signal sequence independent mechanism. PMID:8550517

High-speed plasma imaging: A lightning bolt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wurden, G.A.; Whiteson, D.O.

Using a gated intensified digital Kodak Ektapro camera system, the authors captured a lightning bolt at 1,000 frames per second, with 100-{micro}s exposure time on each consecutive frame. As a thunder storm approaches while darkness descended (7:50 pm) on July 21, 1994, they photographed lightning bolts with an f22 105-mm lens and 100% gain on the intensified camera. This 15-frame sequence shows a cloud to ground stroke at a distance of about 1.5 km, which has a series of stepped leaders propagating downwards, following by the upward-propagating main return stroke.

The Emotional Intelligence of Leaders as Antecedent to Leader-Member Exchanges: A Field Study

ERIC Educational Resources Information Center

Barbuto, John E., Jr.; Bugenhagen, Marilyn J.

2009-01-01

Eighty elected leaders and 388 followers were sampled to test the relationships between leaders' emotional intelligence and the quality of leader-member exchange. Results of the field study found a significant relationship between leaders' emotional intelligence (total) and leader-member exchange quality. Specific subscales of emotional…

Fewer but better: Proportionate size of the group affects evaluation of transgressive leaders.

PubMed

Travaglino, Giovanni A; Abrams, Dominic; Randsley de Moura, Georgina; Yetkili, Orkun

2016-06-01

A group may be badly affected if its leader transgresses important rules. Nonetheless, an emerging body of evidence suggests that in intergroup contexts, group members apply a double standard when judging ingroup leaders - They respond less punitively to transgressions by their leader than by non-leaders. In this article, two experiments investigated how proportionate ingroup size affects reactions to transgressive ingroup leaders. We demonstrate that ingroup leaders from larger, but not smaller, groups benefit from the double standard. The experiments testing the effects of two different types of transgressions (nepotistic favouritism and corruption, respectively) show that transgressive leaders from larger groups are evaluated more positively than both comparable non-leaders and leaders from smaller groups. In contrast, transgressive leaders from smaller groups are evaluated similarly to comparable transgressive non-leaders. Experiment 2 investigated a potential explanation for this phenomenon. Faced with a transgressive leader, members of a smaller group report greater embarrassment than do members of larger groups in relation to the leaders' actions. Implications of these findings and directions for future research are discussed. © 2015 The British Psychological Society.

What separates outstanding from average leaders? A study identifies leadership competencies and implications for professional development.

PubMed

Nygren, D J; Ukeritis, M D

1992-11-01

As the healthcare crisis mounts, healthcare organizations must be managed by especially competent leaders. It is important for executives to assess and develop the competencies necessary to become "outstanding" leaders. In our study of leadership competencies among leaders of religious orders, we found that outstanding and average leaders appear to share characteristics such as the ability to articulate their group's mission, the ability to act efficiently, and the tendency to avoid impulsive behavior or excessive emotional expression. Outstanding leaders, however, differed from average leaders in seemingly small but significant ways. For instance, nearly three times as often as average leaders, outstanding leaders expressed a desire to perform tasks well--or better than they had been performed in the past. The study also assessed how members of religious orders perceived their leaders. In general, they tended to rate leaders of their religious institutes as transformational leaders--leaders who welcomed doing things in a new way and inspiring their own staffs to search out new ways to provide services.

Spliced leader-based metatranscriptomic analyses lead to recognition of hidden genomic features in dinoflagellates.

PubMed

Lin, Senjie; Zhang, Huan; Zhuang, Yunyun; Tran, Bao; Gill, John

2010-11-16

Environmental transcriptomics (metatranscriptomics) for a specific lineage of eukaryotic microbes (e.g., Dinoflagellata) would be instrumental for unraveling the genetic mechanisms by which these microbes respond to the natural environment, but it has not been exploited because of technical difficulties. Using the recently discovered dinoflagellate mRNA-specific spliced leader as a selective primer, we constructed cDNA libraries (e-cDNAs) from one marine and two freshwater plankton assemblages. Small-scale sequencing of the e-cDNAs revealed functionally diverse transcriptomes proven to be of dinoflagellate origin. A set of dinoflagellate common genes and transcripts of dominant dinoflagellate species were identified. Further analyses of the dataset prompted us to delve into the existing, largely unannotated dinoflagellate EST datasets (DinoEST). Consequently, all four nucleosome core histones, two histone modification proteins, and a nucleosome assembly protein were detected, clearly indicating the presence of nucleosome-like machinery long thought not to exist in dinoflagellates. The isolation of rhodopsin from taxonomically and ecotypically diverse dinoflagellates and its structural similarity and phylogenetic affinity to xanthorhodopsin suggest a common genetic potential in dinoflagellates to use solar energy nonphotosynthetically. Furthermore, we found 55 cytoplasmic ribosomal proteins (RPs) from the e-cDNAs and 24 more from DinoEST, showing that the dinoflagellate phylum possesses all 79 eukaryotic RPs. Our results suggest that a sophisticated eukaryotic molecular machine operates in dinoflagellates that likely encodes many more unsuspected physiological capabilities and, meanwhile, demonstrate that unique spliced leaders are useful for profiling lineage-specific microbial transcriptomes in situ.

A strategic approach for managing conflict in hospitals: responding to the Joint Commission leadership standard, Part 2.

PubMed

Scott, Charity; Gerardi, Debra

2011-02-01

A well-designed conflict management process for hospital leaders should both retain the positive benefits of constructive conflict engagement and minimize the adverse consequences that unmanaged conflict can have on patient care. Dispute system design (DSD) experts recommend processes that emphasize the identification of the disputing parties' interests and that avoid reliance on exertions of power or resort to rights. In an emerging trend in designing conflict management systems, focus is placed on the relational dynamics among those involved in the conflict, in recognition of the reciprocal impact that each participant in a conflict has on the other. The aim is then to restore trust and heal damaged relationships as a component of resolution. The intent of Standard LD.02.04.01 is to prevent escalation to formal legal disputes and encourage leaders to overcome their conflict-avoidance tendencies through the use of well-designed approaches that support engagement with conflict. The sequence of collaborative options consists of individual coaching and counseling; informal face-to-face meetings; informal, internally facilitated meetings; informal, externally facilitated meetings; formal mediation; and postdispute analysis and feedback. Every hospital has unique needs, and every conflict management process must be tailored to individual circumstances. The recommendations in this two-part article can be adapted and incorporated in other, more comprehensive conflict management processes throughout the hospital. Expanding the conflict competence of leaders to enable them to effectively engage in and model constructive conflict-handling behaviors will further support the strategic goal of providing safe and effective patient care.

Do lightning positive leaders really "step"?

NASA Astrophysics Data System (ADS)

Petersen, D.

2015-12-01

It has been known for some time that positive leaders exhibit impulsive charge motion and optical emissions as they extend. However, laboratory and field observations have not produced any evidence of a process analogous to the space leader mechanism of negative leader extension. Instead, observations have suggested that the positive leader tip undergoes a continuous to intermittent series of corona streamer bursts, each burst resulting in a small forward extension of the positive leader channel. Traditionally, it has been held that lightning positive leaders extend in a continuous or quasi-continuous fashion. Lately, however, many have become concerned that this position is incongruous with observations of impulsive activity during lightning positive leader extension. It is increasingly suggested that this impulsive activity is evidence that positive leaders also undergo "stepping". There are two issues that must be addressed. The first issue concerns whether or not the physical processes underlying impulsive extension in negative and positive leaders are distinct. We argue that these processes are in fact physically distinct, and offer new high-speed video evidence to support this position. The second issue regards the proper use of the term "step" as an identifier for the impulsive forward extension of a leader. Traditional use of this term has been applied only to negative leaders, due primarily to their stronger impulsive charge motions and photographic evidence of clearly discontinuous forward progression of the luminous channel. Recently, due to the increasing understanding of the distinct "space leader" process of negative leader extension, the term "step" has increasingly come to be associated with the space leader process itself. Should this emerging association, "step" = space leader attachment, be canonized? If not, then it seems reasonable to use the term "step" to describe impulsive positive leader extension. If, however, we do wish to associate the term "step" with space leader attachment, a process unique to negative leaders, should we devise a term for those process(es) that underly impulsive positive leader extension?

Analysis of the vhoGAC and vhtGAC operons from Methanosarcina mazei strain Gö1, both encoding a membrane-bound hydrogenase and a cytochrome b.

PubMed

Deppenmeier, U; Blaut, M; Lentes, S; Herzberg, C; Gottschalk, G

1995-01-15

DNA encompassing the structural genes of two membrane-bound hydrogenases from Methanosarcina mazei Gö1 was cloned and sequenced. The genes, arranged in the order vhoG and vhoA as well as vhtG and vhtA, were identified as those encoding the small and the large subunits of the NiFe hydrogenases [Deppenmeier, U., Blaut, M., Schmidt, B. & Gottschalk, G. (1992) Arch. Microbiol. 157, 505-511]. Northern-blot analysis revealed that the structural genes formed part of two operons, both containing one additional open reading frame (vhoC and vhtC) which codes for a cytochrome b. This conclusion was drawn from the homology of the deduced N-terminal amino acid sequences of vhoC and vhtC and the N-terminus of a 27-kDa cytochrome isolated from Ms. mazei C16. VhoC and VhtC contain four tentative hydrophobic segments which might span the cytoplasmic membrane. Hydropathy plots suggest that His23 and His50 are involved in heme coordination. The comparison of the sequencing data of vhoG and vhtG with the experimentally determined N-terminus of the small subunit indicate the presence of a 48-amino-acid leader peptide in front of the polypeptides. VhoA and VhtA contained the conserved sequence DPCXXC in the C-terminal region, which excludes the presence of a selenocysteine residue in these hydrogenases. Promoter sequences were found upstream of vhoG and vhtG, respectively. Downstream of vhoC, a putative terminator sequence was identified. Alignments of the deduced amino acid sequences of the gene clusters vhoGAC and vhtGAC showed 92-97% identity. Only the C-termini of VhoC and VhtC were not similar.

Spliced Leader RNAs, Mitochondrial Gene Frameshifts and Multi-Protein Phylogeny Expand Support for the Genus Perkinsus as a Unique Group of Alveolates

PubMed Central

Zhang, Huan; Campbell, David A.; Sturm, Nancy R.; Dungan, Christopher F.; Lin, Senjie

2011-01-01

The genus Perkinsus occupies a precarious phylogenetic position. To gain a better understanding of the relationship between perkinsids, dinoflagellates and other alveolates, we analyzed the nuclear-encoded spliced-leader (SL) RNA and mitochondrial genes, intron prevalence, and multi-protein phylogenies. In contrast to the canonical 22-nt SL found in dinoflagellates (DinoSL), P. marinus has a shorter (21-nt) and a longer (22-nt) SL with slightly different sequences than DinoSL. The major SL RNA transcripts range in size between 80–83 nt in P. marinus, and ∼83 nt in P. chesapeaki, significantly larger than the typical ≤56-nt dinoflagellate SL RNA. In most of the phylogenetic trees based on 41 predicted protein sequences, P. marinus branched at the base of the dinoflagellate clade that included the ancient taxa Oxyrrhis and Amoebophrya, sister to the clade of apicomplexans, and in some cases clustered with apicomplexans as a sister to the dinoflagellate clade. Of 104 Perkinsus spp. genes examined 69.2% had introns, a higher intron prevalence than in dinoflagellates. Examination of Perkinsus spp. mitochondrial cytochrome B and cytochrome C oxidase subunit I genes and their cDNAs revealed no mRNA editing, but these transcripts can only be translated when frameshifts are introduced at every AGG and CCC codon as if AGGY codes for glycine and CCCCU for proline. These results, along with the presence of the numerous uncharacterized ‘marine alveolate group I' and Perkinsus-like lineages separating perkinsids from core dinoflagellates, expand support for the affiliation of the genus Perkinsus with an independent lineage (Perkinsozoa) positioned between the phyla of Apicomplexa and Dinoflagellata. PMID:21629701

Progress toward heterologous expression of active G-protein-coupled receptors in Saccharomyces cerevisiae: Linking cellular stress response with translocation and trafficking

PubMed Central

O'Malley, Michelle A; Mancini, J Dominic; Young, Carissa L; McCusker, Emily C; Raden, David; Robinson, Anne S

2009-01-01

High-level expression of mammalian G-protein-coupled receptors (GPCRs) is a necessary step toward biophysical characterization and high-resolution structure determination. Even though many heterologous expression systems have been used to express mammalian GPCRs at high levels, many receptors are improperly trafficked or are inactive in these systems. En route to engineering a robust microbial host for GPCR expression, we have investigated the expression of 12 GPCRs in the yeast Saccharomyces cerevisiae, where all receptors are expressed at the mg/L scale. However, only the human adenosine A2a (hA2aR) receptor is active for ligand-binding and located primarily at the plasma membrane, whereas other tested GPCRs are mainly retained within the cell. Selective receptors associate with BiP, an ER-resident chaperone, and activated the unfolded protein response (UPR) pathway, which suggests that a pool of receptors may be folded incorrectly. Leader sequence cleavage of the expressed receptors was complete for the hA2aR, as expected, and partially cleaved for hA2bR, hCCR5R, and hD2LR. Ligand-binding assays conducted on the adenosine family (hA1R, hA2aR, hA2bR, and hA3R) of receptors show that hA2aR and hA2bR, the only adenosine receptors that demonstrate leader sequence processing, display activity. Taken together, these studies point to translocation as a critical limiting step in the production of active mammalian GPCRs in S. cerevisiae. PMID:19760666

Molecular recognition of pre-tRNA by Arabidopsis protein-only Ribonuclease P.

PubMed

Klemm, Bradley P; Karasik, Agnes; Kaitany, Kipchumba J; Shanmuganathan, Aranganathan; Henley, Matthew J; Thelen, Adam Z; Dewar, Allison J L; Jackson, Nathaniel D; Koutmos, Markos; Fierke, Carol A

2017-12-01

Protein-only ribonuclease P (PRORP) is an enzyme responsible for catalyzing the 5' end maturation of precursor transfer ribonucleic acids (pre-tRNAs) encoded by various cellular compartments in many eukaryotes. PRORPs from plants act as single-subunit enzymes and have been used as a model system for analyzing the function of the metazoan PRORP nuclease subunit, which requires two additional proteins for efficient catalysis. There are currently few molecular details known about the PRORP-pre-tRNA complex. Here, we characterize the determinants of substrate recognition by the single subunit Arabidopsis thaliana PRORP1 and PRORP2 using kinetic and thermodynamic experiments. The salt dependence of binding affinity suggests 4-5 contacts with backbone phosphodiester bonds on substrates, including a single phosphodiester contact with the pre-tRNA 5' leader, consistent with prior reports of short leader requirements. PRORPs contain an N-terminal pentatricopeptide repeat (PPR) domain, truncation of which results in a >30-fold decrease in substrate affinity. While most PPR-containing proteins have been implicated in single-stranded sequence-specific RNA recognition, we find that the PPR motifs of PRORPs recognize pre-tRNA substrates differently. Notably, the PPR domain residues most important for substrate binding in PRORPs do not correspond to positions involved in base recognition in other PPR proteins. Several of these residues are highly conserved in PRORPs from algae, plants, and metazoans, suggesting a conserved strategy for substrate recognition by the PRORP PPR domain. Furthermore, there is no evidence for sequence-specific interactions. This work clarifies molecular determinants of PRORP-substrate recognition and provides a new predictive model for the PRORP-substrate complex. © 2017 Klemm et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Ketamine use for rapid sequence intubation in Australian and New Zealand emergency departments from 2010 to 2015: A registry study.

PubMed

Ferguson, Ian; Alkhouri, Hatem; Fogg, Toby; Aneman, Anders

2018-06-11

This study aimed to quantify the proportion of patients undergoing rapid sequence intubation using ketamine in Australian and New Zealand EDs between 2010 and 2015. The Australian and New Zealand Emergency Department Airway Registry is a multicentre airway registry prospectively capturing data from 43 sites. Data on demographics and physiology, the attending staff and indication for intubation were recorded. The primary outcome was the annual percentage of patients intubated with ketamine. A logistic regression analysis was conducted to evaluate the factors associated with ketamine use. A total of 4658 patients met inclusion criteria. The annual incidence of ketamine use increased from 5% to 28% over the study period (P < 0.0001). In the logistic regression analysis, the presence of an emergency physician as a team leader was the strongest predictor of ketamine use (odds ratio [OR] 1.83, 95% confidence interval [CI] 1.44-2.34). The OR for an increase in one point on the Glasgow Coma Scale was 1.10 (95% CI 1.07-1.12), whereas an increase of 1 mmHg of systolic blood pressure had an OR of 0.98 (95% CI 0.98-0.99). Intubation occurring in a major referral hospital had an OR of 0.68 (95% CI 0.56-0.82), while trauma conferred an OR of 1.38 (95% CI 1.25-1.53). Ketamine use increased between 2010 and 2015. Lower systolic blood pressure, the presence of an emergency medicine team leader, trauma and a higher Glasgow Coma Scale were associated with increased odds of ketamine use. Intubation occurring in a major referral centre was associated with lower odds of ketamine use. © 2018 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Structural basis for NKG2A/CD94 recognition of HLA-E

PubMed Central

Kaiser, Brett K.; Pizarro, Juan Carlos; Kerns, Julie; Strong, Roland K.

2008-01-01

The NKG2x/CD94 (x = A, C, E) natural killer-cell receptors perform an important role in immunosurveillance by binding to HLA-E complexes that exclusively present peptides derived from MHC class I leader sequences, thereby monitoring MHC class I expression. We have determined the crystal structure of the NKG2A/CD94/HLA-E complex at 4.4-Å resolution, revealing two critical aspects of this interaction. First, the C-terminal region of the peptide, which displays the most variability among class I leader sequences, interacts entirely with CD94, the invariant component of these receptors. Second, residues 167–170 of NKG2A/C account for the ≈6-fold-higher affinity of the inhibitory NKG2A/CD94 receptor compared to its activating NKG2C/CD94 counterpart. These residues do not contact HLA-E or peptide directly but instead form part of the heterodimer interface with CD94. An evolutionary analysis across primates reveals that whereas CD94 is evolving under purifying selection, both NKG2A and NKG2C are evolving under positive selection. Specifically, residues at the CD94 interface have evolved under positive selection, suggesting that the evolution of these genes is driven by an interaction with pathogen-derived ligands. Consistent with this possibility, we show that NKG2C/CD94, but not NKG2A/CD94, weakly but specifically binds to the CMV MHC-homologue UL18. Thus, the evolution of the NKG2x/CD94 family of receptors has likely been shaped both by the need to bind the invariant HLA-E ligand and the need to avoid subversion by pathogen-derived decoys. PMID:18448674

Identification of a Novel Feline Picornavirus from the Domestic Cat

PubMed Central

Lau, Susanna K. P.; Woo, Patrick C. Y.; Yip, Cyril C. Y.; Choi, Garnet K. Y.; Wu, Ying; Bai, Ru; Fan, Rachel Y. Y.; Lai, Kenneth K. Y.; Chan, Kwok-Hung

2012-01-01

While picornaviruses are known to infect different animals, their existence in the domestic cat was unknown. We describe the discovery of a novel feline picornavirus (FePV) from stray cats in Hong Kong. From samples from 662 cats, FePV was detected in fecal samples from 14 cats and urine samples from 2 cats by reverse transcription-PCR (RT-PCR). Analysis of five FePV genomes revealed a distinct phylogenetic position and genomic features, with low sequence homologies to known picornaviruses especially in leader and 2A proteins. Among the viruses that belong to the closely related bat picornavirus groups 1 to 3 and the genus Sapelovirus, G+C content and sequence analysis of P1, P2, and P3 regions showed that FePV is most closely related to bat picornavirus group 3. However, FePV possessed other distinct features, including a putative type IV internal ribosome entry site/segment (IRES) instead of type I IRES in bat picornavirus group 3, protein cleavage sites, and H-D-C catalytic triad in 3Cpro different from those in sapeloviruses and bat picornaviruses, and the shortest leader protein among known picornaviruses. These results suggest that FePV may belong to a new genus in the family Picornaviridae. Western blot analysis using recombinant FePV VP1 polypeptide showed a high seroprevalence of 33.6% for IgG among the plasma samples from 232 cats tested. IgM was also detected in three cats positive for FePV in fecal samples, supporting recent infection in these cats. Further studies are important to understand the pathogenicity, epidemiology, and genetic evolution of FePV in these common pet animals. PMID:22031936

RNA binding specificity of Ebola virus transcription factor VP30.

PubMed

Schlereth, Julia; Grünweller, Arnold; Biedenkopf, Nadine; Becker, Stephan; Hartmann, Roland K

2016-09-01

The transcription factor VP30 of the non-segmented RNA negative strand Ebola virus balances viral transcription and replication. Here, we comprehensively studied RNA binding by VP30. Using a novel VP30:RNA electrophoretic mobility shift assay, we tested truncated variants of 2 potential natural RNA substrates of VP30 - the genomic Ebola viral 3'-leader region and its complementary antigenomic counterpart (each ∼155 nt in length) - and a series of other non-viral RNAs. Based on oligonucleotide interference, the major VP30 binding region on the genomic 3'-leader substrate was assigned to the internal expanded single-stranded region (∼ nt 125-80). Best binding to VP30 was obtained with ssRNAs of optimally ∼ 40 nt and mixed base composition; underrepresentation of purines or pyrimidines was tolerated, but homopolymeric sequences impaired binding. A stem-loop structure, particularly at the 3'-end or positioned internally, supports stable binding to VP30. In contrast, dsRNA or RNAs exposing large internal loops flanked by entirely helical arms on both sides are not bound. Introduction of a 5´-Cap(0) structure impaired VP30 binding. Also, ssDNAs bind substantially weaker than isosequential ssRNAs and heparin competes with RNA for binding to VP30, indicating that ribose 2'-hydroxyls and electrostatic contacts of the phosphate groups contribute to the formation of VP30:RNA complexes. Our results indicate a rather relaxed RNA binding specificity of filoviral VP30, which largely differs from that of the functionally related transcription factor of the Paramyxoviridae which binds to ssRNAs as short as 13 nt with a preference for oligo(A) sequences.

Characterisation and In Silico Analysis of Interleukin-4 cDNA of Nilgai (Boselaphus tragocamelus) and Indian Buffalo (Bubalus bubalis)

PubMed Central

Saini, M.; Palai, T. K.; Das, D. K.; Hatle, K. M.; Gupta, P. K.

2013-01-01

Interleukin-4 (IL-4) produced from Th2 cells modulates both innate and adaptive immune responses. It is a common belief that wild animals possess better immunity against diseases than domestic and laboratory animals; however, the immune system of wild animals is not fully explored yet. Therefore, a comparative study was designed to explore the wildlife immunity through characterisation of IL-4 cDNA of nilgai, a wild ruminant, and Indian buffalo, a domestic ruminant. Total RNA was extracted from peripheral blood mononuclear cells of nilgai and Indian buffalo and reverse transcribed into cDNA. Respective cDNA was further cloned and sequenced. Sequences were analysed in silico and compared with their homologues available at GenBank. The deduced 135 amino acid protein of nilgai IL-4 is 95.6% similar to that of Indian buffalo. N-linked glycosylation sequence, leader sequence, Cysteine residues in the signal peptide region, and 3′ UTR of IL-4 were found to be conserved across species. Six nonsynonymous nucleotide substitutions were found in Indian buffalo compared to nilgai amino acid sequence. Tertiary structure of this protein in both species was modeled, and it was found that this protein falls under 4-helical cytokines superfamily and short chain cytokine family. Phylogenetic analysis revealed a single cluster of ruminants including both nilgai and Indian buffalo that was placed distinct from other nonruminant mammals. PMID:24348167

Complete genome sequence and integrated protein localization and interaction map for alfalfa dwarf virus, which combines properties of both cytoplasmic and nuclear plant rhabdoviruses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bejerman, Nicolás, E-mail: n.bejerman@uq.edu.au; Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD 4072; Giolitti, Fabián

Summary: We have determined the full-length 14,491-nucleotide genome sequence of a new plant rhabdovirus, alfalfa dwarf virus (ADV). Seven open reading frames (ORFs) were identified in the antigenomic orientation of the negative-sense, single-stranded viral RNA, in the order 3′-N-P-P3-M-G-P6-L-5′. The ORFs are separated by conserved intergenic regions and the genome coding region is flanked by complementary 3′ leader and 5′ trailer sequences. Phylogenetic analysis of the nucleoprotein amino acid sequence indicated that this alfalfa-infecting rhabdovirus is related to viruses in the genus Cytorhabdovirus. When transiently expressed as GFP fusions in Nicotiana benthamiana leaves, most ADV proteins accumulated in the cellmore » periphery, but unexpectedly P protein was localized exclusively in the nucleus. ADV P protein was shown to have a homotypic, and heterotypic nuclear interactions with N, P3 and M proteins by bimolecular fluorescence complementation. ADV appears unique in that it combines properties of both cytoplasmic and nuclear plant rhabdoviruses. - Highlights: • The complete genome of alfalfa dwarf virus is obtained. • An integrated localization and interaction map for ADV is determined. • ADV has a genome sequence similarity and evolutionary links with cytorhabdoviruses. • ADV protein localization and interaction data show an association with the nucleus. • ADV combines properties of both cytoplasmic and nuclear plant rhabdoviruses.« less

The complete genome structure and phylogenetic relationship of infectious hematopoietic necrosis virus

USGS Publications Warehouse

Morzunov , Sergey P.; Winton, James R.; Nichol, Stuart T.

1995-01-01

Infectious hematopoietic necrosis virus (IHNV), a member of the family Rhabdoviridae, causes a severe disease with high mortality in salmonid fish. The nucleotide sequence (11, 131 bases) of the entire genome was determined for the pathogenic WRAC strain of IHNV from southern Idaho. This allowed detailed analysis of all 6 genes, the deduced amino acid sequences of their encoded proteins, and important control motifs including leader, trailer and gene junction regions. Sequence analysis revealed that the 6 virus genes are located along the genome in the 3′ to 5′ order: nucleocapsid (N), polymerase-associated phosphoprotein (P or M1), matrix protein (M or M2), surface glycoprotein (G), a unique non-virion protein (NV) and virus polymerase (L). The IHNV genome RNA was found to have highly complementary termini (15 of 16 nucleotides). The gene junction regions display the highly conserved sequence UCURUC(U)7RCCGUG(N)4CACR (in the vRNA sense), which includes the typical rhabdovirus transcription termination/polyadenylation signal and a novel putative transcription initiation signal. Phylogenetic analysis of M, G and L protein sequences allowed insights into the evolutionary and taxonomic relationship of rhabdoviruses of fish relative to those of insects or mammals, and a broader sense of the relationship of non-segmented negative-strand RNA viruses. Based on these data, a new genus, piscivirus, is proposed which will initially contain IHNV, viral hemorrhagic septicemia virus and Hirame rhabdovirus.

Cultivating a culture of research in nursing through a journal club for leaders: A pilot study.

PubMed

Kjerholt, Mette; Hølge-Hazelton, Bibi

2018-01-01

To describe whether an action learning-inspired journal club for nurse leaders can develop the leaders' self-perceived competences to support a research culture in clinical nursing practice. Development of clinical research capacity and nurse leaders with the requisite competences are key factors in evidence-based health care practice. This study describes how nurse leaders at a large regional hospital took part in a journal club for nurse leaders, with a view to developing their competences to support a nursing research culture in their departments. A pilot study using a multimethod approach to evaluate the journal club for nurse leaders. Four nurse leaders participated in the journal club for nurse leaders. Content analysis on the data was performed. Data revealed that participation in journal club for nurse leaders gave the leaders a feeling of increased competences to support nursing research culture in their departments. They stated that the action learning approach and the competences of the facilitator were key factors in this outcome. An action learning-inspired journal club for nurse leaders can be useful and meaningful to nurse leaders in developing leadership competences. As an approach in journal club for nurse leaders, action learning can develop nurse leaders' competence to support a research culture, and thus ensure evidence-based nursing is practised. © 2017 John Wiley & Sons Ltd.

Genes from the medicinal leech (Hirudo medicinalis) coding for unusual enzymes that specifically cleave endo-epsilon (gamma-Glu)-Lys isopeptide bonds and help to dissolve blood clots.

PubMed

Zavalova, L; Lukyanov, S; Baskova, I; Snezhkov, E; Akopov, S; Berezhnoy, S; Bogdanova, E; Barsova, E; Sverdlov, E D

1996-11-27

We previously detected in salivary gland secretions of the medicinal leech (Hirudo medicinalis) a novel enzymatic activity, endo-epsilon(gamma-Glu)-Lys isopeptidase, which cleaves isopeptide bonds formed by transglutaminase (Factor XIIIa) between glutamine gamma-carboxamide and the epsilon-amino group of lysine. Such isopeptide bonds, either within or between protein polypeptide chains are formed in many biological processes. However, before we started our work no enzymes were known to be capable of specifically splitting isopeptide bonds in proteins. The isopeptidase activity we detected was specific for isopeptide bonds. The enzyme was termed destabilase. Here we report the first purification of destabilase, part of its amino acid sequence isolation and sequencing of two related cDNAs derived from the gene family that encodes destabilase proteins, and the detection of isopeptidase activity encoded by one of these cDNAs cloned in a baculovirus expression vector. The deduced mature protein products of these cDNAs contain 115 and 116 amino acid residues, including 14 highly conserved Cys residues, and are formed from precursors containing specific leader peptides. No homologous sequences were found in public databases.

Genetic diversity of Trypanosoma cruzi in bats, and multilocus phylogenetic and phylogeographical analyses supporting Tcbat as an independent DTU (discrete typing unit).

PubMed

Lima, Luciana; Espinosa-Álvarez, Oneida; Ortiz, Paola A; Trejo-Varón, Javier A; Carranza, Julio C; Pinto, C Miguel; Serrano, Myrna G; Buck, Gregory A; Camargo, Erney P; Teixeira, Marta M G

2015-11-01

Trypanosoma cruzi is a complex of phenotypically and genetically diverse isolates distributed in six discrete typing units (DTUs) designated as TcI-TcVI. Five years ago, T. cruzi isolates from Brazilian bats showing unique patterns of traditional ribosomal and spliced leader PCRs not clustering into any of the six DTUs were designated as the Tcbat genotype. In the present study, phylogenies inferred using SSU rRNA (small subunit of ribosomal rRNA), gGAPDH (glycosomal glyceraldehyde 3-phosphate dehydrogenase) and Cytb (cytochrome b) genes strongly supported Tcbat as a monophyletic lineage prevalent in Brazil, Panama and Colombia. Providing strong support for Tcbat, sequences from 37 of 47 nuclear and 12 mitochondrial genes (retrieved from a draft genome of Tcbat) and reference strains of all DTUs available in databanks corroborated Tcbat as an independent DTU. Consistent with previous studies, multilocus analysis of most nuclear genes corroborated the evolution of T. cruzi from bat trypanosomes its divergence into two main phylogenetic lineages: the basal TcII; and the lineage clustering TcIV, the clade comprising TcIII and the sister groups TcI-Tcbat. Most likely, the common ancestor of Tcbat and TcI was a bat trypanosome. However, the results of the present analysis did not support Tcbat as the ancestor of all DTUs. Despite the insights provided by reports of TcIII, TcIV and TcII in bats, including Amazonian bats harbouring TcII, further studies are necessary to understand the roles played by bats in the diversification of all DTUs. We also demonstrated that in addition to value as molecular markers for DTU assignment, Cytb, ITS rDNA and the spliced leader (SL) polymorphic sequences suggest spatially structured populations of Tcbat. Phylogenetic and phylogeographical analyses, multiple molecular markers specific to Tcbat, and the degrees of sequence divergence between Tcbat and the accepted DTUs strongly support the definitive classification of Tcbat as a new DTU. Copyright © 2015 Elsevier B.V. All rights reserved.

The evolution of leader-follower reciprocity: the theory of service-for-prestige.

PubMed

Price, Michael E; Van Vugt, Mark

2014-01-01

We describe the service-for-prestige theory of leadership, which proposes that voluntary leader-follower relations evolved in humans via a process of reciprocal exchange that generated adaptive benefits for both leaders and followers. We propose that although leader-follower relations first emerged in the human lineage to solve problems related to information sharing and social coordination, they ultimately evolved into exchange relationships whereby followers could compensate leaders for services which would otherwise have been prohibitively costly for leaders to provide. In this exchange, leaders incur costs to provide followers with public goods, and in return, followers incur costs to provide leaders with prestige (and associated fitness benefits). Because whole groups of followers tend to gain from leader-provided public goods, and because prestige is costly for followers to produce, the provisioning of prestige to leaders requires solutions to the "free rider" problem of disrespectful followers (who benefit from leader services without sharing the costs of producing prestige). Thus service-for-prestige makes the unique prediction that disrespectful followers of beneficial leaders will be targeted by other followers for punitive sentiment and/or social exclusion. Leader-follower relations should be more reciprocal and mutually beneficial when leaders and followers have more equal social bargaining power. However, as leaders gain more relative power, and their high status becomes less dependent on their willingness to pay the costs of benefitting followers, service-for-prestige predicts that leader-follower relations will become based more on leaders' ability to dominate and exploit rather than benefit followers. We review evidential support for a set of predictions made by service-for-prestige, and discuss how service-for-prestige relates to social neuroscience research on leadership.

Team-oriented leadership: the interactive effects of leader group prototypicality, accountability, and team identification.

PubMed

Giessner, Steffen R; van Knippenberg, Daan; van Ginkel, Wendy; Sleebos, Ed

2013-07-01

We examined the interactive effects of leader group prototypicality, accountability, and team identification on team-oriented behavior of leaders, thus extending the social identity perspective on leadership to the study of leader behavior. An experimental study (N = 152) supported our hypothesis that leader accountability relates more strongly to team-oriented behavior for group nonprototypical leaders than for group prototypical leaders. A multisource field study with leaders (N = 64) and their followers (N = 209) indicated that this interactive effect is more pronounced for leaders who identify more strongly with their team. We discuss how these findings further develop the social identity analysis of leadership. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Role of TAR RNA splicing in translational regulation of simian immunodeficiency virus from rhesus macaques.

PubMed Central

Viglianti, G A; Rubinstein, E P; Graves, K L

1992-01-01

The untranslated leader sequences of rhesus macaque simian immunodeficiency virus mRNAs form a stable secondary structure, TAR. This structure can be modified by RNA splicing. In this study, the role of TAR splicing in virus replication was investigated. The proportion of viral RNAs containing a spliced TAR structure is high early after infection and decreases at later times. Moreover, proviruses containing mutations which prevent TAR splicing are significantly delayed in replication. These mutant viruses require approximately 20 days to achieve half-maximal virus production, in contrast to wild-type viruses, which require approximately 8 days. We attribute this delay to the inefficient translation of unspliced-TAR-containing mRNAs. The molecular basis for this translational effect was examined in in vitro assays. We found that spliced-TAR-containing mRNAs were translated up to 8.5 times more efficiently than were similar mRNAs containing an unspliced TAR leader. Furthermore, these spliced-TAR-containing mRNAs were more efficiently associated with ribosomes. We postulate that the level of TAR splicing provides a balance for the optimal expression of both viral proteins and genomic RNA and therefore ultimately controls the production of infectious virions. Images PMID:1629957

Trust in direct leaders and top leaders: A trickle-up model.

PubMed

Fulmer, C Ashley; Ostroff, Cheri

2017-04-01

Low levels of employee trust in top leaders pose challenges to organizations with respect to retention, performance, and profits. This research examines how trust in top leaders can be fostered through the relationships individuals have with their direct leaders. We propose a trickle-up model whereby trust in direct leaders exerts an upward influence on trust in top leaders. Drawing on the group value model, we predict that direct leaders' procedural justice serves as the key mechanism in facilitating the trickle-up process. Further, this process should be particularly strong for employees high on vertical collectivism, and the trickled-up trust in top leaders should exert a stronger impact on employees' overall performance in the organization than trust in direct leaders. Multiphase and multisource data from 336 individuals support these hypotheses. The findings advance our understanding of trust and leadership by highlighting that trust in leaders at different levels does not form independently and that trust in leaders trickles up across hierarchical levels. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Leader charisma and affective team climate: the moderating role of the leader's influence and interaction.

PubMed

Hernández Baeza, Ana; Araya Lao, Cristina; García Meneses, Juliana; González Romá, Vicente

2009-11-01

In this study, we evaluate the role of leader charisma in fostering positive affective team climate and preventing negative affective climate. The analysis of a longitudinal database of 137 bank branches by means of hierarchical moderated regression shows that leader charisma has a stronger effect on team optimism than on team tension. In addition, the leader's influence and the frequency of leader-team interaction moderate the relationship between charisma and affective climate. However, whereas the leader's influence enhances the relationship between leader charisma and positive affective climate, the frequency of interaction has counterproductive effects.

The leader peptide of mutacin 1140 has distinct structural components compared to related class I lantibiotics

PubMed Central

Escano, Jerome; Stauffer, Byron; Brennan, Jacob; Bullock, Monica; Smith, Leif

2014-01-01

Lantibiotics are ribosomally synthesized peptide antibiotics composed of an N-terminal leader peptide that promotes the core peptide's interaction with the post translational modification (PTM) enzymes. Following PTMs, mutacin 1140 is transported out of the cell and the leader peptide is cleaved to yield the antibacterial peptide. Mutacin 1140 leader peptide is structurally unique compared to other class I lantibiotic leader peptides. Herein, we further our understanding of the structural differences of mutacin 1140 leader peptide with regard to other class I leader peptides. We have determined that the length of the leader peptide is important for the biosynthesis of mutacin 1140. We have also determined that mutacin 1140 leader peptide contains a novel four amino acid motif compared to related lantibiotics. PTM enzyme recognition of the leader peptide appears to be evolutionarily distinct from related class I lantibiotics. Our study on mutacin 1140 leader peptide provides a basis for future studies aimed at understanding its interaction with the PTM enzymes. PMID:25400246

Educators as Serving Leaders in the Classroom and on Campus

ERIC Educational Resources Information Center

Bowman, Richard

2014-01-01

Counterintuitively, the more one develops as a leader, the less of a leader one becomes. What do great leaders do? Great leaders are ambitious first and foremost for the cause, the mission, the work--not themselves. Educators as "serving leaders" sense that every action they take, together with every decision that they make, either…

CGAT: a model for immersive personalized training in computational genomics

PubMed Central

Sims, David; Ponting, Chris P.

2016-01-01

How should the next generation of genomics scientists be trained while simultaneously pursuing high quality and diverse research? CGAT, the Computational Genomics Analysis and Training programme, was set up in 2010 by the UK Medical Research Council to complement its investment in next-generation sequencing capacity. CGAT was conceived around the twin goals of training future leaders in genome biology and medicine, and providing much needed capacity to UK science for analysing genome scale data sets. Here we outline the training programme employed by CGAT and describe how it dovetails with collaborative research projects to launch scientists on the road towards independent research careers in genomics. PMID:25981124

Variation of the channel temperature in the transmission of lightning leader

NASA Astrophysics Data System (ADS)

Chang, Xuan; Yuan, Ping; Cen, Jianyong; Wang, Xuejuan

2017-06-01

According to the time-resolved spectra of the lightning stepped leader and dart leader processes, the channel temperature, its evolution characteristics with time and the variation along the channel height in the transmission process were analyzed. The results show that the stepped leader tip has a slightly higher temperature than the trailing end, which should be caused by a large amount of electric charges on the leader tip. In addition, both temperature and brightness are enhanced at the position of the channel node. The dart leader has a higher channel temperature than the stepped leader but a lower temperature than the return stroke. Meanwhile, the channel temperature of the dart leader obviously increases when the dart leader propagates to the ground.

Are you ready? Crisis leadership in a hyper-VUCA environment.

PubMed

Alkhaldi, Khaldoon H; Austin, Meredith L; Cura, Boris A; Dantzler, Darrell; Holland, Leslie; Maples, David L; Quarrelles, Jamie C; Weinkle, Robert K; Marcus, Leonard J

2017-01-01

The current hyper-volatile, -uncertain, -complex, and -ambiguous (VUCA) threat environment demands a more cohesive support structure for crisis leaders who may be faced with crises of increasing magnitude and frequency and, in some instances, multiple crisis events simultaneously. The project team investigates the perceptions of crisis leaders regarding establishing a crisis leader advisor position for crisis leaders to benefit from their experience while prosecuting crisis response activities. The team linked hyper-VUCA crises, crisis response frameworks, meta-leadership, crisis leader attributes, and advisor attributes. The overall goal of the project is to increase the ability of the crisis leaders to more effectively and efficiently navigate crisis events resulting in more efficient and effective response and recovery. Three research questions were developed to assess the following: thoughts of integrating a crisis leader advisor position; development of a crisis leader advisor certification program; and attributes of crisis leader advisors. A qualitative research methodology using a phenomenological approach was employed. Forty-one participants were purposefully selected and administered a short, online survey consisting of 11 questions. Data were analyzed using percentage analysis, weighted sums, and inductive thematic analysis. The project team found an overwhelming support for the crisis leader advisor position and the crisis leader advisor certification program. Additionally, experience and trustworthiness ranked among the top sought after attributes of a crisis leader advisor. The team recommendations included (1) implement a crisis leaders advisor guide/framework; (2) create a formal crisis leader advisor position in national incident management system; (3) implement a crisis leader advisor certification framework; (4) benchmark established advisor programs; and (5) implement a framework to match leaders and advisors.

Are you ready? Crisis leadership in a hyper-VUCA environment.

PubMed

Alkhaldi, Khaldoon H; Austin, Meredith L; Cura, Boris A; Dantzler, Darrell; Holland, Leslie; Maples, David L; Quarrelles, Jamie C; Weinkle, Robert K; Marcus, Leonard J

The current hyper-volatile, -uncertain, -complex, and -ambiguous (VUCA) threat environment demands a more cohesive support structure for crisis leaders who may be faced with crises of increasing magnitude and frequency and, in some instances, multiple crisis events simultaneously. The project team investigates the perceptions of crisis leaders regarding establishing a crisis leader advisor position for crisis leaders to benefit from their experience while prosecuting crisis response activities. The team linked hyper-VUCA crises, crisis response frameworks, meta-leadership, crisis leader attributes, and advisor attributes. The overall goal of the project is to increase the ability of the crisis leaders to more effectively and efficiently navigate crisis events resulting in more efficient and effective response and recovery. Three research questions were developed to assess the following: thoughts of integrating a crisis leader advisor position; development of a crisis leader advisor certification program; and attributes of crisis leader advisors. A qualitative research methodology using a phenomenological approach was employed. Forty-one participants were purposefully selected and administered a short, on-line survey consisting of 11 questions. Data were analyzed using percentage analysis, weighted sums, and inductive thematic analysis. The project team found an overwhelming support for the crisis leader advisor position and the crisis leader advisor certification program. Additionally, experience and trustworthiness ranked among the top sought after attributes of a crisis leader advisor. The team recommendations included (1) implement a crisis leaders advisor guide/framework; (2) create a formal crisis leader advisor position in national incident management system; (3) implement a crisis leader advisor certification framework; (4) benchmark established advisor programs; and (5) implement a framework to match leaders and advisors.

Are you ready? Crisis leadership in a hyper-VUCA environment.

PubMed

Alkhaldi, Khaldoon H; Austin, Meredith L; Cura, Boris A; Dantzler, Darrell; Holland, Leslie; Maples, David L; Quarrelles, Jamie C; Weinkle, Robert K; Marcus, Leonard J

The current hyper-volatile, -uncertain, -complex, and -ambiguous (VUCA) threat environment demands a more cohesive support structure for crisis leaders who may be faced with crises of increasing magnitude and frequency and, in some instances, multiple crisis events simultaneously. The project team investigates the perceptions of crisis leaders regarding establishing a crisis leader advisor position for crisis leaders to benefit from their experience while prosecuting crisis response activities. The team linked hyper-VUCA crises, crisis response frameworks, meta-leadership, crisis leader attributes, and advisor attributes. The overall goal of the project is to increase the ability of the crisis leaders to more effectively and efficiently navigate crisis events resulting in more efficient and effective response and recovery. Three research questions were developed to assess the following: thoughts of integrating a crisis leader advisor position; development of a crisis leader advisor certification program; and attributes of crisis leader advisors. A qualitative research methodology using a phenomenological approach was employed. Forty-one participants were purposefully selected and administered a short, on-line survey consisting of 11 questions. Data were analyzed using percentage analysis,weighted sums, and inductive thematic analysis. The project team found an overwhelming support for the crisis leader advisor position and the crisis leader advisor certification program. Additionally, experience and trustworthiness ranked among the top sought after attributes of a crisis leader advisor. The team recommendations included (1) implement a crisis leaders advisor guide/framework; (2) create a formal crisis leader advisor position in national incident management system; (3) implement a crisis leader advisor certification framework; (4) benchmark established advisor programs; and (5) implement a framework to match leaders and advisors.

Sequencing the cap-snatching repertoire of H1N1 influenza provides insight into the mechanism of viral transcription initiation

PubMed Central

Koppstein, David; Ashour, Joseph; Bartel, David P.

2015-01-01

The influenza polymerase cleaves host RNAs ∼10–13 nucleotides downstream of their 5′ ends and uses this capped fragment to prime viral mRNA synthesis. To better understand this process of cap snatching, we used high-throughput sequencing to determine the 5′ ends of A/WSN/33 (H1N1) influenza mRNAs. The sequences provided clear evidence for nascent-chain realignment during transcription initiation and revealed a strong influence of the viral template on the frequency of realignment. After accounting for the extra nucleotides inserted through realignment, analysis of the capped fragments indicated that the different viral mRNAs were each prepended with a common set of sequences and that the polymerase often cleaved host RNAs after a purine and often primed transcription on a single base pair to either the terminal or penultimate residue of the viral template. We also developed a bioinformatic approach to identify the targeted host transcripts despite limited information content within snatched fragments and found that small nuclear RNAs and small nucleolar RNAs contributed the most abundant capped leaders. These results provide insight into the mechanism of viral transcription initiation and reveal the diversity of the cap-snatched repertoire, showing that noncoding transcripts as well as mRNAs are used to make influenza mRNAs. PMID:25901029

Lactobacillus buchneri genotyping on the basis of clustered regularly interspaced short palindromic repeat (CRISPR) locus diversity.

PubMed

Briner, Alexandra E; Barrangou, Rodolphe

2014-02-01

Clustered regularly interspaced short palindromic repeats (CRISPR) in combination with associated sequences (cas) constitute the CRISPR-Cas immune system, which uptakes DNA from invasive genetic elements as novel "spacers" that provide a genetic record of immunization events. We investigated the potential of CRISPR-based genotyping of Lactobacillus buchneri, a species relevant for commercial silage, bioethanol, and vegetable fermentations. Upon investigating the occurrence and diversity of CRISPR-Cas systems in Lactobacillus buchneri genomes, we observed a ubiquitous occurrence of CRISPR arrays containing a 36-nucleotide (nt) type II-A CRISPR locus adjacent to four cas genes, including the universal cas1 and cas2 genes and the type II signature gene cas9. Comparative analysis of CRISPR spacer content in 26 L. buchneri pickle fermentation isolates associated with spoilage revealed 10 unique locus genotypes that contained between 9 and 29 variable spacers. We observed a set of conserved spacers at the ancestral end, reflecting a common origin, as well as leader-end polymorphisms, reflecting recent divergence. Some of these spacers showed perfect identity with phage sequences, and many spacers showed homology to Lactobacillus plasmid sequences. Following a comparative analysis of sequences immediately flanking protospacers that matched CRISPR spacers, we identified a novel putative protospacer-adjacent motif (PAM), 5'-AAAA-3'. Overall, these findings suggest that type II-A CRISPR-Cas systems are valuable for genotyping of L. buchneri.

Development of Proteogenomic Approaches to Analyze the Role of Virus-Microbe Interactions in Shaping Natural Microbial Communities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banfield, Jillian; Breitbart, Mya; VerBerkmoes, Nathan

CRISPRs (clustered regularly interspaced short palindromic repeats) are adaptive immune systems in Bacteria and Archaea. Transcripts of the spacers that separate the repeats confer immunity through sequence identity with a targeted region (proto-spacer) in phage/viral, plasmid, or other foreign DNA. Short sequences immediately flanking the proto-spacer (proto-spacer adjacent motifs—PAMs) are important in both procuring spacers from and providing immunity to targeted sequences. New spacers are incorporated unidirectionally at the leader end of the CRISPR loci, thus recording a timeline of recent viral exposure. In the early phase of our research, we documented extremely rapid diversification of the CRISPR loci inmore » natural populations [Tyson and Banfield, 2008] matched by high levels of sequence variation in natural viral populations [Andersson and Banfield, 2008]. Since then, in a genetically tractable model laboratory system, we have 1) tracked phage mutation and CRISPR diversification, and in a natural model system, we have 2) examined population history via over time, 3) investigated the timescale over which spacers become ineffective and the process by which ineffective spacers are removed, and 4) analyzed viral diversity. In addition to research activities, our group has organized five international CRISPR meetings, the fifth to be held at University of California, Berkeley in June 2012. Most importantly, the project provided the majority of funding support for Christine Sun (Ph.D. 2012).« less

Complete sequence of Tvv1, a family of Ty 1 copia-like retrotransposons of Vitis vinifera L., reconstituted by chromosome walking.

PubMed

Pelsy, F.; Merdinoglu, D.

2002-09-01

A chromosome-walking strategy was used to sequence and characterize retrotransposons in the grapevine genome. The reconstitution of a family of retroelements, named Tvv1, was achieved by six successive steps. These elements share a single, highly conserved open reading frame 4,153 nucleotides-long, putatively encoding the gag, pro, int, rt and rh proteins. Comparison of the Tvv1 open reading frame coding potential with those of drosophila copia and tobacco Tnt1, revealed that Tvv1 is closely related to Ty 1 copia-like retrotransposons. A highly variable untranslated leader region, upstream of the open reading frame, allowed us to differentiate Tvv1 variants, which represent a family of at least 28 copies, in varying sizes. This internal region is flanked by two long terminal repeats in direct orientation, sized between 149 and 157 bp. Among elements theoretically sized from 4,970 to 5,550 bp, we describe the full-length sequence of a reference element Tvv1-1, 5,343 nucleotides-long. The full-length sequence of Tvv1-1 compared to pea PDR1 shows a 53.3% identity. In addition, both elements contain long terminal repeats of nearly the same size in which the U5 region could be entirely absent. Therefore, we assume that Tvv1 and PDR1 could constitute a particular class of short LTRs retroelements.

Leadership behavior and subordinate stress: a 360 degrees view.

PubMed

Offermann, L R; Hellmann, P S

1996-10-01

Relationships between leader behavior and subordinate work stress were examined from the perspectives of 343 leaders, their bosses, and their subordinates. Leader behaviors did relate to stress experienced by staff; however, leaders' views of what related to subordinate stress did not always coincide with the factors that subordinates themselves associated with stress. The relationships of leader delegation and subordinate participation to lower subordinate reports of stress were particularly underestimated by leaders. Implications for developing leaders as agents for employee stress reduction are discussed.

LEADER AND MEMBER ATTITUDES TOWARD CO-WORKERS, INTERGROUP COMPETITION, AND THE EFFECTIVENESS AND ADJUSTMENT OF MILITARY SQUADS.

DTIC Science & Technology

greater esteem for the squad leader than did low LPC squads, (2) leader LPC and intergroup competition interacted to affect adjustment and task...This study investigated the joint effects of (1) the squad leader’s esteem for his least preferred co-worker (leader LPC), (2) the mean LPC of the...effectiveness in that squads with high LPC leaders were superior in the non-competitive condition, whereas squads with low LPC leaders were superior in the

Evaluating pharmacy leader development through the seven action logics.

PubMed

Philip, Achsah; Desai, Avani; Nguyen, Phouc Anne; Birney, Patrick; Colavecchia, Anthony; Karralli, Rusol; Smith, Lindsey; Lorimer, Dirk; Burgess, Gwen; Munch, Kyle; Daniel, Nelvin; Lionetti, Jason; Garey, Kevin W

2016-01-15

Pharmacy leader development over time was analyzed using the seven action logics. As part of an ongoing leadership seminar series, students were required to select a visionary pharmacy leader and conduct a structured interview to evaluate pharmacy leaders' action logics. A standardized questionnaire comprising 13 questions was created by the class. Questions addressed leadership qualities during the leaders' early years, education years, and work years. Transcripts were then coded by two separate trained investigators based on the leader's stage of life to provide a score for each action logic individually over time. Kappa coefficient was used to evaluate interrater agreement. A total of 14 leaders were interviewed. All leaders were currently employed and had won national awards for their contributions to pharmacy practice. Overall, there was 82% agreement between the two evaluators' scores for the various characteristics. Action logics changed based on the leaders' life stage. Using aggregate data from all leader interviews, a progression from lower-order action logics (opportunist, diplomat, expert) to higher-order action logics (strategist, alchemist) was found. Ten leaders (71%) were diplomats during their early years. Six leaders (43%) were experts during their education years, and 4 (29%) were strategists or alchemists. During the third life stage analyzed (the work years), 6 leaders (43%) were strategists, and 2 were alchemists. During their work years, all leaders had a percentage of their answers coded as alchemist (range, 5-22%). Throughout their professional careers, pharmacy leaders continually develop skills through formal education and mentorship that follow action logics. Copyright © 2016 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Resilient Women Educational Leaders in Turbulent Times: Applying the Leader Resilience Profile® to Assess Women's Leadership Strengths

ERIC Educational Resources Information Center

Reed, Diane E.; Blaine, Bruce

2015-01-01

Women leaders across the world confront a common challenge: extremely turbulent times that challenge even the most skillful leaders. The paper begins with a brief overview of the meaning of leader resilience and describes the resilience cycle that all leaders experience when adversity strikes. Five phases of the resilience cycle discussed are:…

The IT Leader as Alchemist: Finding the True Gold

ERIC Educational Resources Information Center

Bleed, Ron

2006-01-01

The Information technology (IT) leader within higher education can be viewed from three scenarios: (1) the IT leader as plumber; (2) the IT leader as gardener; and (3) the IT leader as alchemist. In the first scenario, the college or university network consists of pipes, and the role of the IT leader resembles that of a plumber, who keeps the…

An RNA motif advances transcription by preventing Rho-dependent termination

PubMed Central

Sevostyanova, Anastasia; Groisman, Eduardo A.

2015-01-01

The transcription termination factor Rho associates with most nascent bacterial RNAs as they emerge from RNA polymerase. However, pharmacological inhibition of Rho derepresses only a small fraction of these transcripts. What, then, determines the specificity of Rho-dependent transcription termination? We now report the identification of a Rho-antagonizing RNA element (RARE) that hinders Rho-dependent transcription termination. We establish that RARE traps Rho in an inactive complex but does not prevent Rho binding to its recruitment sites. Although translating ribosomes normally block Rho access to an mRNA, inefficient translation of an open reading frame in the leader region of the Salmonella mgtCBR operon actually enables transcription of its associated coding region by favoring an RNA conformation that sequesters RARE. The discovery of an RNA element that inactivates Rho signifies that the specificity of nucleic-acid binding proteins is defined not only by the sequences that recruit these proteins but also by sequences that antagonize their activity. PMID:26630006

The leader peptide of mutacin 1140 has distinct structural components compared to related class I lantibiotics.

PubMed

Escano, Jerome; Stauffer, Byron; Brennan, Jacob; Bullock, Monica; Smith, Leif

2014-12-01

Lantibiotics are ribosomally synthesized peptide antibiotics composed of an N-terminal leader peptide that promotes the core peptide's interaction with the post translational modification (PTM) enzymes. Following PTMs, mutacin 1140 is transported out of the cell and the leader peptide is cleaved to yield the antibacterial peptide. Mutacin 1140 leader peptide is structurally unique compared to other class I lantibiotic leader peptides. Herein, we further our understanding of the structural differences of mutacin 1140 leader peptide with regard to other class I leader peptides. We have determined that the length of the leader peptide is important for the biosynthesis of mutacin 1140. We have also determined that mutacin 1140 leader peptide contains a novel four amino acid motif compared to related lantibiotics. PTM enzyme recognition of the leader peptide appears to be evolutionarily distinct from related class I lantibiotics. Our study on mutacin 1140 leader peptide provides a basis for future studies aimed at understanding its interaction with the PTM enzymes. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

What about the leader? Crossover of emotional exhaustion and work engagement from followers to leaders.

PubMed

Wirtz, Nina; Rigotti, Thomas; Otto, Kathleen; Loeb, Carina

2017-01-01

Although a growing body of research links leadership behavior to follower health, comparatively little is known about the health effects of being in the lead. This longitudinal study of 315 team members and 67 leaders examined the crossover of emotional exhaustion and work engagement from followers to leaders. Leader emotional self-efficacy was tested as a moderator in the crossover process. Multiple regression analyses revealed that followers' work engagement was positively related to leaders' work engagement eight months later, controlling for followers' tenure with the leader, leader gender, autonomy, workload, and work engagement at Time 1. Leaders' emotional self-efficacy did not moderate the crossover of work engagement. Followers' emotional exhaustion was not directly related to leaders' emotional exhaustion over time. We did find a significant interaction effect for follower emotional exhaustion and leader emotional self-efficacy. This study is the first to show that crossover of emotional exhaustion and work engagement can unfold over time from team members to leaders. Main theoretical implications lie in the finding that-in line with job demands-resources theory-followers' psychological states can pose a demand or resource for leaders, and influence their well-being. For practitioners, our results offer valuable insights regarding the design of organizational health interventions as well as leadership development measures. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Bearing-based localization for leader-follower formation control

PubMed Central

Han, Qing; Ren, Shan; Lang, Hao; Zhang, Changliang

2017-01-01

The observability of the leader robot system and the leader-follower formation control are studied. First, the nonlinear observability is studied for when the leader robot observes landmarks. Second, the system is shown to be completely observable when the leader robot observes two different landmarks. When the leader robot system is observable, multi-robots can rapidly form and maintain a formation based on the bearing-only information that the follower robots observe from the leader robot. Finally, simulations confirm the effectiveness of the proposed formation control. PMID:28426706

A new statistical time-dependent model of earthquake occurrence: failure processes driven by a self-correcting model

NASA Astrophysics Data System (ADS)

Rotondi, Renata; Varini, Elisa

2016-04-01

The long-term recurrence of strong earthquakes is often modelled by the stationary Poisson process for the sake of simplicity, although renewal and self-correcting point processes (with non-decreasing hazard functions) are more appropriate. Short-term models mainly fit earthquake clusters due to the tendency of an earthquake to trigger other earthquakes; in this case, self-exciting point processes with non-increasing hazard are especially suitable. In order to provide a unified framework for analyzing earthquake catalogs, Schoenberg and Bolt proposed the SELC (Short-term Exciting Long-term Correcting) model (BSSA, 2000) and Varini employed a state-space model for estimating the different phases of a seismic cycle (PhD Thesis, 2005). Both attempts are combinations of long- and short-term models, but results are not completely satisfactory, due to the different scales at which these models appear to operate. In this study, we split a seismic sequence in two groups: the leader events, whose magnitude exceeds a threshold magnitude, and the remaining ones considered as subordinate events. The leader events are assumed to follow a well-known self-correcting point process named stress release model (Vere-Jones, J. Phys. Earth, 1978; Bebbington & Harte, GJI, 2003, Varini & Rotondi, Env. Ecol. Stat., 2015). In the interval between two subsequent leader events, subordinate events are expected to cluster at the beginning (aftershocks) and at the end (foreshocks) of that interval; hence, they are modeled by a failure processes that allows bathtub-shaped hazard function. In particular, we have examined the generalized Weibull distributions, a large family that contains distributions with different bathtub-shaped hazard as well as the standard Weibull distribution (Lai, Springer, 2014). The model is fitted to a dataset of Italian historical earthquakes and the results of Bayesian inference are shown.

Two Paralogous Families of a Two-Gene Subtilisin Operon Are Widely Distributed in Oral Treponemes

PubMed Central

Correia, Frederick F.; Plummer, Alvin R.; Ellen, Richard P.; Wyss, Chris; Boches, Susan K.; Galvin, Jamie L.; Paster, Bruce J.; Dewhirst, Floyd E.

2003-01-01

Certain oral treponemes express a highly proteolytic phenotype and have been associated with periodontal diseases. The periodontal pathogen Treponema denticola produces dentilisin, a serine protease of the subtilisin family. The two-gene operon prcA-prtP is required for expression of active dentilisin (PrtP), a putative lipoprotein attached to the treponeme's outer membrane or sheath. The purpose of this study was to examine the diversity and structure of treponemal subtilisin-like proteases in order to better understand their distribution and function. The complete sequences of five prcA-prtP operons were determined for Treponema lecithinolyticum, “Treponema vincentii,” and two canine species. Partial operon sequences were obtained for T. socranskii subsp. 04 as well as 450- to 1,000-base fragments of prtP genes from four additional treponeme strains. Phylogenetic analysis demonstrated that the sequences fall into two paralogous families. The first family includes the sequence from T. denticola. Treponemes possessing this operon family express chymotrypsin-like protease activity and can cleave the substrate N-succinyl-alanyl-alanyl-prolyl-phenylalanine-p-nitroanilide (SAAPFNA). Treponemes possessing the second paralog family do not possess chymotrypsin-like activity or cleave SAAPFNA. Despite examination of a range of protein and peptide substrates, the specificity of the second protease family remains unknown. Each of the fully sequenced prcA and prtP genes contains a 5′ hydrophobic leader sequence with a treponeme lipobox. The two paralogous families of treponeme subtilisins represent a new subgroup within the subtilisin family of proteases and are the only subtilisin lipoprotein family. The present study demonstrated that the subtilisin paralogs comprising a two-gene operon are widely distributed among treponemes. PMID:14617650

Quantitation of next generation sequencing library preparation protocol efficiencies using droplet digital PCR assays - a systematic comparison of DNA library preparation kits for Illumina sequencing.

PubMed

Aigrain, Louise; Gu, Yong; Quail, Michael A

2016-06-13

The emergence of next-generation sequencing (NGS) technologies in the past decade has allowed the democratization of DNA sequencing both in terms of price per sequenced bases and ease to produce DNA libraries. When it comes to preparing DNA sequencing libraries for Illumina, the current market leader, a plethora of kits are available and it can be difficult for the users to determine which kit is the most appropriate and efficient for their applications; the main concerns being not only cost but also minimal bias, yield and time efficiency. We compared 9 commercially available library preparation kits in a systematic manner using the same DNA sample by probing the amount of DNA remaining after each protocol steps using a new droplet digital PCR (ddPCR) assay. This method allows the precise quantification of fragments bearing either adaptors or P5/P7 sequences on both ends just after ligation or PCR enrichment. We also investigated the potential influence of DNA input and DNA fragment size on the final library preparation efficiency. The overall library preparations efficiencies of the libraries show important variations between the different kits with the ones combining several steps into a single one exhibiting some final yields 4 to 7 times higher than the other kits. Detailed ddPCR data also reveal that the adaptor ligation yield itself varies by more than a factor of 10 between kits, certain ligation efficiencies being so low that it could impair the original library complexity and impoverish the sequencing results. When a PCR enrichment step is necessary, lower adaptor-ligated DNA inputs leads to greater amplification yields, hiding the latent disparity between kits. We describe a ddPCR assay that allows us to probe the efficiency of the most critical step in the library preparation, ligation, and to draw conclusion on which kits is more likely to preserve the sample heterogeneity and reduce the need of amplification.

Substitutes for procedural fairness: prototypical leaders are endorsed whether they are fair or not.

PubMed

Ullrich, Johannes; Christ, Oliver; van Dick, Rolf

2009-01-01

This article extends research on leader procedural fairness as well as the social identity model of leadership effectiveness (SIMOL) by demonstrating that leader prototypicality can act as a substitute for procedural fairness. Although procedural fairness in general and voice in particular have been found to have a robust positive influence on leader endorsement, the authors showed in an experimental scenario study and a correlational field study that the influence of voice on leader endorsement is substantially reduced when leaders are perceived as prototypical for the group that they lead and followers are highly identified with their group. Additionally, supportive of predictions of the SIMOL, leader prototypicality interacted with follower identification in predicting leader endorsement, such that prototypicality had a positive effect on leader endorsement, which was enhanced among high identifiers. Overall, these results suggest that leaders who are attuned to their followers' group identity can afford to go it alone, for the better or the worse. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Stepped-to-dart Leaders in Cloud-to-ground Lightning

NASA Astrophysics Data System (ADS)

Stolzenburg, M.; Marshall, T. C.; Karunarathne, S.; Karunarathna, N.; Warner, T.; Orville, R. E.

2013-12-01

Using time-correlated high-speed video (50,000 frames per second) and fast electric field change (5 MegaSamples per second) data for lightning flashes in East-central Florida, we describe an apparently rare type of subsequent leader: a stepped leader that finds and follows a previously used channel. The observed 'stepped-to-dart leaders' occur in three natural negative ground flashes. Stepped-to-dart leader connection altitudes are 3.3, 1.6 and 0.7 km above ground in the three cases. Prior to the stepped-to-dart connection, the advancing leaders have properties typical of stepped leaders. After the connection, the behavior changes almost immediately (within 40-60 us) to dart or dart-stepped leader, with larger amplitude E-change pulses and faster average propagation speeds. In this presentation, we will also describe the upward luminosity after the connection in the prior return stroke channel and in the stepped leader path, along with properties of the return strokes and other leaders in the three flashes.

Think manager--think male in adolescents and its relation to sexism and emotions in leadership.

PubMed

García-Ael, Cristina; Cuadrado, Isabel; Molero, Fernando

2013-01-01

From the perspective of the Think manager--think male, this study was conducted to examine the type of leadership role depending on gender in a sample of 158 Spanish adolescents -according to three types of leaders: "male middle leader", "female middle leader" and "middle leader in general". The kind of emotional expression (positive and negative) evoked by their leadership behaviors (task- and relationship- oriented) was also analyzed. Lastly, whether adolescents' sexist beliefs affected the attribution of traits and the emotional expression towards these leaders was examined. Results showed that task-oriented traits were more characteristic of the leadership role than relationship-oriented traits. Adolescents expressed more positive emotions towards a task-oriented leader and towards a leader behaving in ways associated with both task- and relationship- oriented styles, but only for men. Finally, hostile sexism predicted fewer task-oriented traits to female leaders, more negative affect towards task-oriented male leaders and towards counter-stereotypic leaders. These results were moderated by the sex of adolescents.

In the moral eye of the beholder: the interactive effects of leader and follower moral identity on perceptions of ethical leadership and LMX quality.

PubMed

Giessner, Steffen R; Van Quaquebeke, Niels; van Gils, Suzanne; van Knippenberg, Daan; Kollée, Janine A J M

2015-01-01

Previous research indicated that leader moral identity (MI; i.e., leaders' self-definition in terms of moral attributes) predicts to what extent followers perceive their leader as ethical (i.e., demonstrating and promoting ethical conduct in the organization). Leadership, however, is a relational process that involves leaders and followers. Building on this understanding, we hypothesized that follower and leader MI (a) interact in predicting whether followers will perceive their leaders as ethical and, as a result, (b) influence followers' perceptions of leader-follower relationship quality. A dyadic field study (N = 101) shows that leader MI is a stronger predictor of followers' perceptions of ethical leadership for followers who are high (vs. low) in MI. Perceptions of ethical leadership in turn predict how the quality of the relationship will be perceived. Hence, whether leader MI translates to perceptions of ethical leadership and of better relationship quality depends on the MI of followers.

Leadership Training Module on Enable Others to Act (Kouzes & Posner)

ERIC Educational Resources Information Center

Sharma, Ananya

2013-01-01

Everyone has either come in contact with a leader or played the role of a leader. Everyone has also worked with effective leaders and ineffective leaders. And all of us want to work with leaders who can share a vision with us and empower and enable us to meet our goals. One can say that leaders play a crucial role in the success or failure of a…

Teaching Leadership

ERIC Educational Resources Information Center

Leshnower, Susan

2008-01-01

When thinking of leaders, people usually think of those in positions of power, such as political leaders, religious leaders, or student leaders. Yet, leaders can be found in all spheres of life, and leadership behaviors can be learned particularly in a small-group format (Hellriegel, Jackson, & Slocum, 2005). This article presents ideas and…

Exploring Leader Identity and Development.

PubMed

Priest, Kerry L; Middleton, Eric

2016-01-01

Taking on a leader identity can be a motivating force for pursuing leader development. This chapter explores the reciprocal and recursive nature of identity development and leader development, emphasizing how shifting views of self influence one's motivation to develop as a leader. © 2016 Wiley Periodicals, Inc., A Wiley Company.

What Is an Innovative Educational Leader?

ERIC Educational Resources Information Center

Marron, Joseph M.; Cunniff, Dan

2014-01-01

This paper outlined the traits of an innovative educational leader in our changing society. It discussed the difference in a manager and leader, as well as the specific dispositions that differentiate the innovative educational leader from what many consider the average leader. The authors used the acronym "HELPSS" to highlight the…

Leaders' mental health at work: Empirical, methodological, and policy directions.

PubMed

Barling, Julian; Cloutier, Anika

2017-07-01

While employees' mental health is the focus of considerable attention from researchers, the public, and policymakers, leaders' mental health has almost escaped attention. We start by considering several reasons for this, followed by discussions of the effects of leaders' mental health on their own leadership behaviors, the emotional toll of high-quality leadership, and interventions to enhance leaders' mental health. We offer 8 possible directions for future research on leaders' mental health. Finally, we discuss methodological obstacles encountered when investigating leaders' mental health, and policy dilemmas raised by leaders' mental health. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Growing Nurse Leaders: Their Perspectives on Nursing Leadership and Today’s Practice Environment

PubMed

Dyess, Susan M; Sherman, Rose O; Pratt, Beth A; Chiang-Hanisko, Lenny

2016-01-14

With the growing complexity of healthcare practice environments and pending nurse leader retirements, the development of future nurse leaders is increasingly important. This article reports on focus group research conducted with Generation Y nurses prior to their initiating coursework in a Master’s Degree program designed to support development of future nurse leaders. Forty-four emerging nurse leaders across three program cohorts participated in this qualitative study conducted to capture perspectives about nursing leaders and leadership. Conventional content analysis was used to analyze and code the data into categories. We discuss the three major categories identified, including: idealistic expectations of leaders, leading in a challenging practice environment, and cautious but optimistic outlook about their own leadership and future, and study limitations. The conclusion offers implications for future nurse leader development. The findings provide important insight into the viewpoints of nurses today about leaders and leadership.

Leader social accounts of subordinates' unethical behavior: Examining observer reactions to leader social accounts with moral disengagement language.

PubMed

Dang, Carolyn T; Umphress, Elizabeth E; Mitchell, Marie S

2017-10-01

When providing social accounts (Sitkin & Bies, 1993) for the unethical conduct of subordinates, leaders may use language consistent with cognitive strategies described by Bandura (1991, 1999) in his work on moral disengagement. That is, leader's social accounts may reframe or reconstrue subordinates' unethical conduct such that it appears less reprehensible. We predict observers will respond negatively to leaders when they use moral disengagement language within social accounts and, specifically, observers will ostracize these leaders. In addition, we predict that observer moral disengagement propensity moderates this effect, such that the relationship between leaders' use of moral disengagement language within a social account and ostracism is stronger when observer moral disengagement propensity is lower versus higher. Finally, we predict that the reason why observers ostracize the leader is because observers perceive the leader's social account with moral disengagement language as unethical. Thus, perceived leader social account ethicality is predicted to mediate the interaction effect of leader's use of moral disengagement language within social accounts and observer moral disengagement propensity on ostracism. Results from an experiment and field study support our predictions. Implications for theory and practice are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Leader narcissism and follower outcomes: The counterbalancing effect of leader humility.

PubMed

Owens, Bradley P; Wallace, Angela S; Walker, Angela S; Waldman, David A

2015-07-01

[Correction Notice: An Erratum for this article was reported in Vol 100(4) of Journal of Applied Psychology (see record 2015-29666-001). The last name of the second author was misspelled in the Online First version of the article. All versions of this article have been corrected.] In response to recent calls to theorize and examine how multiple leader characteristics may work together in their effects, the current research examines how leader narcissism and humility interact to predict perceived leader effectiveness and follower (i.e., direct-report) job engagement and performance. Although an examination of leaders who are narcissistic yet humble may seem oxymoronic and even paradoxical, researchers have suggested that seemingly contradictory personal attributes may exist simultaneously and may actually work together to produce positive outcomes. Results from survey data from followers and leaders working for a large health insurance organization showed that the interaction of leader narcissism and leader humility is associated with perceptions of leader effectiveness, follower job engagement, and subjective and objective follower job performance. Together, these results suggest that narcissistic leaders can have positive effects on followers when their narcissism is tempered by humility. (c) 2015 APA, all rights reserved).

The Humble Leader: Association of Discrepancies in Leader and Follower Ratings of Implementation Leadership With Organizational Climate in Mental Health.

PubMed

Aarons, Gregory A; Ehrhart, Mark G; Torres, Elisa M; Finn, Natalie K; Beidas, Rinad S

2017-02-01

Discrepancies, or perceptual distance, between leaders' self-ratings and followers' ratings of the leader are common but usually go unrecognized. Research on discrepancies is limited, but there is evidence that discrepancies are associated with organizational context. This study examined the association of leader-follower discrepancies in Implementation Leadership Scale (ILS) ratings of mental health clinic leaders and the association of those discrepancies with organizational climate for involvement and performance feedback. Both involvement and performance feedback are important for evidence-based practice (EBP) implementation in mental health. A total of 593 individuals-supervisors (leaders, N=80) and clinical service providers (followers, N=513)-completed surveys that included ratings of implementation leadership and organizational climate. Polynomial regression and response surface analyses were conducted to examine the associations of discrepancies in leader-follower ILS ratings with organizational involvement climate and performance feedback climate, aspects of climate likely to support EBP implementation. Both involvement climate and performance feedback climate were highest where leaders rated themselves low on the ILS and their followers rated those leaders high on the ILS ("humble leaders"). Teams with "humble leaders" showed more positive organizational climate for involvement and for performance feedback, contextual factors important during EBP implementation and sustainment. Discrepancy in leader and follower ratings of implementation leadership should be a consideration in understanding and improving leadership and organizational climate for mental health services and for EBP implementation and sustainment in mental health and other allied health settings.

Could Relatedness Help Explain Why Individuals Lead in Bottlenose Dolphin Groups?

PubMed Central

Lewis, Jennifer S.; Wartzok, Douglas; Heithaus, Michael; Krützen, Michael

2013-01-01

In many species, particular individuals consistently lead group travel. While benefits to followers often are relatively obvious, including access to resources, benefits to leaders are often less obvious. This is especially true for species that feed on patchy mobile resources where all group members may locate prey simultaneously and food intake likely decreases with increasing group size. Leaders in highly complex habitats, however, could provide access to foraging resources for less informed relatives, thereby gaining indirect benefits by helping kin. Recently, leadership has been documented in a population of bottlenose dolphins (Tursiops truncatus) where direct benefits to leaders appear unlikely. To test whether leaders could benefit indirectly we examined relatedness between leader-follower pairs and compared these levels to pairs who associated but did not have leader-follower relationship (neither ever led the other). We found the average relatedness value for leader-follower pairs was greater than expected based on chance. The same was not found when examining non leader-follower pairs. Additionally, relatedness for leader-follower pairs was positively correlated with association index values, but no correlation was found for this measure in non leader-follower pairs. Interestingly, haplotypes were not frequently shared between leader-follower pairs (25%). Together, these results suggest that bottlenose dolphin leaders have the opportunity to gain indirect benefits by leading relatives. These findings provide a potential mechanism for the maintenance of leadership in a highly dynamic fission-fusion population with few obvious direct benefits to leaders. PMID:23516445

Not even the past: The joint influence of former leader and new leader during leader succession in the midst of organizational change.

PubMed

Zhao, Helen H; Seibert, Scott E; Taylor, M Susan; Lee, Cynthia; Lam, Wing

2016-12-01

Leader succession often occurs during organizational change processes, but the implications of leader succession, in terms of reactions to the change, rarely have been investigated. Employee attitudes and behaviors during organizational change may be influenced jointly by a former leader who recently has transitioned out of the team and the new leader who recently has transitioned into it. We predict an interaction between former and new leaders' transformational leadership on employees' behavioral resistance to and support for change. On the basis of contrast effect theory, a highly transformational former leader constrains the potential effectiveness of the new leader, but a former leader low in transformational leadership enhances this potential effectiveness. We also propose conditional indirect effects transmitted through commitment to the changing organization. Our research was conducted in a large Chinese hospitality organization that was implementing radical organizational change, during which virtually all aspects of processes and products are changed. We collected a 2-wave multisource data from employees who had recently experienced a leader succession and their newly assigned leaders. On the basis of a final sample of 203 employees from 22 teams, we found empirical support for the proposed interaction effects. The conditional indirect effects were also consistent with our expectations, but the effect on behavioral resistance to change was stronger than the effect on behavioral support for change. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Outreach in natural settings: the use of peer leaders for HIV prevention among injecting drug users' networks.

PubMed Central

Latkin, C A

1998-01-01

OBJECTIVE: Guided by a social influence and empowerment framework, peer leaders in the injecting drug user (IDU) community were trained to promote human immunodeficiency virus (HIV) prevention among their contacts within and beyond their sex and drug networks. METHODS: From 1994 to 1995 in Baltimore, Maryland, 36 peer leaders who participated in the 10-session training program were administered pretest and posttest surveys. Evaluation included leaders' self-reported HIV-related behaviors and outreach activities. Survey data also were collected from 78 of the leaders' risk network members. RESULTS: Peer leaders reported a significant increase in condom use and in cleaning used needles with bleach. The leaders' risk network members, compared with controls, were significantly more likely to report greater needle hygiene. In an assessment of diffusion of information, the majority of risk network members who were current injectors reported receiving needle-cleaning materials from the leaders, and the majority of risk network members were able to correctly identify the HIV prevention slogans that had been taught to the leaders. The leaders documented 2165 HIV prevention interactions, of which 84% were with active drug users. CONCLUSIONS: The results from this study suggest that, in the IDU community, training peer leaders as HIV educators may promote HIV prevention among the leaders' risk network members and others at risk of acquiring and transmitting HIV. This training also may provide the leaders with effective prosocial roles. PMID:9722820

Leader-Member Exchange Theory in Higher and Distance Education

ERIC Educational Resources Information Center

Power, Robert Leo

2013-01-01

Unlike many other prominent leadership theories, leader-member exchange (LMX) theory does not focus on the specific characteristics of an effective organizational leader. Rather, LMX focuses on the nature and quality of the relationships between a leader and his or her individual subordinates. The ideal is for a leader to develop as many…

34 CFR 1100.1 - What is the Literacy Leader Fellowship Program?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 3 2010-07-01 2010-07-01 false What is the Literacy Leader Fellowship Program? 1100.1... INSTITUTE FOR LITERACY NATIONAL INSTITUTE FOR LITERACY: LITERACY LEADER FELLOWSHIP PROGRAM § 1100.1 What is the Literacy Leader Fellowship Program? (a) Under the Literacy Leader Fellowship Program, the Director...

The Accuracy of Perceptions of Education Finance Information: How Well Local Leaders Understand Local Communities

ERIC Educational Resources Information Center

De Luca, Barbara M.; Hinshaw, Steven A.; Ziswiler, Korrin

2013-01-01

The purpose for this research was to determine the accuracy of the perceptions of school administrators and community leaders regarding education finance information. School administrators and community leaders in this research project included members of three groups: public school administrators, other public school leaders, and leaders in the…

Senior Leader Career Management: Implications for Senior Leaders and Organizations

ERIC Educational Resources Information Center

Larkin, Jean

2012-01-01

This qualitative research study across three large consumer products organizations explored career management of senior leaders to gain an understanding of what is important to senior leaders in their careers and what strategies they are using for career management. It also investigated senior leaders' expectations of organizations for career…

Personality and leader effectiveness: a moderated mediation model of leadership self-efficacy, job demands, and job autonomy.

PubMed

Ng, Kok-Yee; Ang, Soon; Chan, Kim-Yin

2008-07-01

The trait theory of leadership is advanced by a joint investigation of the mediating role of (a) leadership self-efficacy (LSE = leader's perceived capabilities to perform leader roles) in linking neuroticism, extraversion, and conscientiousness with leader effectiveness and (b) the moderating role of job demands and job autonomy in influencing the mediation. Using K. J. Preacher, D. D. Rucker, and A. F. Hayes' (2007) moderated mediation framework, the authors tested the model (over a 2-year period) with matched data from 394 military leaders and their supervisors. Results showed that LSE mediated the relationships for neuroticism, extraversion, and conscientiousness with leader effectiveness. Moderated mediation analyses further revealed that LSE mediated the relationships for (a) all 3 personality variables for only those leaders with low job demands; (b) neuroticism and conscientiousness for only those leaders with high job autonomy; and (c) extraversion, regardless of a leader's level of job autonomy. Results underscore the importance of accounting for leaders' situational contexts when examining the relationships between personality, LSE, and effectiveness.

Sustaining leaders of cancer support groups: the role, needs, and difficulties of leaders.

PubMed

Butow, Phyllis; Ussher, Jane; Kirsten, Laura; Hobbs, Kim; Smith, Katharine; Wain, Gerald; Sandoval, Mirjana; Stenlake, Annie

2005-01-01

Cancer support groups are an important source of support for cancer patients, yet little is known about the characteristics of, and barriers to, effective leadership, and the training needs of both professionally trained and untrained leaders. This study explored the views of 179 leaders of 184 cancer support groups in NSW, Australia, regarding these issues. Four hundred and sixteen members of 50 groups selected from the larger cohort completed questionnaires eliciting the importance of group processes, including leader qualities, and satisfaction with group leadership. Finally, members of nine groups participated in focus groups regarding effective group processes. The importance of the leader(s) was emphasized in all stages of the research. Fifty-nine percent of group leaders were currently experiencing a difficulty, primarily related to infrastructure or group process. Three characteristics of effective leaders were identified: educational qualities, facilitation skills, and personal qualities. There is clearly a need to develop and evaluate effective interventions to maintain leaders in these roles, if the proven benefits for cancer patients are to be protected.

When leaders harass: the impact of target perceptions of organizational leadership and climate on harassment reporting and outcomes.

PubMed

Offermann, Lynn R; Malamut, Adam B

2002-10-01

Using cases of harassment by leaders, the authors examined the effects of target perceptions of leader responses to sexual harassment and whether leader implementation of harassment policies made a difference beyond the impact of the policies themselves. Results showed that women who perceived that leaders made honest efforts to stop harassment felt significantly freer to report harassment, were more satisfied with the complaint process, and reported greater commitment than did those viewing leaders as more harassment tolerant. Different leadership levels had different effects, with hierarchically proximal leaders generally having the greatest impact. Leadership mediated the relationship between organizational policy and outcomes, supporting the view that a key role for leaders is establishing an ethical organizational climate that reinforces formal harassment policies through actions.

Becoming a nursing faculty leader.

PubMed

Young, Patricia K; Pearsall, Catherine; Stiles, Kim A; Horton-Deutsch, Sara

2011-01-01

Academic leaders are one component of a well-prepared faculty that is required to achieve and sustain excellent educational programs. But what is it like to become an academic leader? How does one become a leader? These questions were addressed in an interpretive study in which nurse faculty leaders were interviewed about the experience of becoming a leader. Interview texts were analyzed hermeneutically by a research team to uncover three themes (common, shared experiences): Being Thrust into Leadership, Taking Risks, and Facing Challenges, which are explicated in this article. This study develops the evidence base for leadership preparation at a time when there is a strong need for nursing education leaders in academia.

Exploring the impact of training on the experience of Australian support group leaders: current practices and implications for research

PubMed Central

Zordan, Rachel D.; Juraskova, Ilona; Butow, Phyllis N; Jolan, Afsaneh; Kirsten, Laura; Chapman, Julie; Sedgwick, Christine; Charles, Margaret; Sundquist, Kendra

2010-01-01

Abstract Background  Existing literature suggests that the effectiveness of a support group is linked to the qualifications, skills and experience of the group leader. Yet, little research has been conducted into the experiences of trained vs. untrained support group leaders of chronic‐illness support groups. The current study aimed to compare the experience of leaders, trained vs. untrained in group facilitation, in terms of challenges, rewards and psychological wellbeing. Methods  A total of 358 Australian leaders of cancer and multiple sclerosis (MS) support groups, recruited through State Cancer Councils and the MS society (response rate of 66%), completed a mailed survey. Results  Compared with untrained leaders, those with training were significantly younger, leading smaller groups and facilitating more groups, more frequently (all P < 0.05). Trained leaders were more likely to be female, educated beyond high school, paid to facilitate, a recipient of formal supervision and more experienced (in years) (all P < 0.01). Untrained leaders reported more challenges than trained leaders (P < 0.03), particularly struggling with being contacted outside of group meetings (52%) and a lack of leadership training (47%). Regardless of level of training, leaders identified a number of unmet support and training needs. Overwhelmingly, leaders found their facilitation role rewarding and the majority reported a high level of psychological wellbeing. Conclusions  Group facilitator training has the potential to reduce the burden of support group leadership. Developing interventions to assist support group leaders will be particularly beneficial for leaders with minimal or no training group facilitation training. PMID:20550596

Developing Army Leaders for 21st Century Missions: Teaching Army Leaders Behavioral Science Theories to Educate and Prepare for Full Spectrum Operations

DTIC Science & Technology

2002-07-01

reckoned with and one that is likely to succeed. Leaders who effectively motivate their soldiers inspire , encourage, and guide them toward mission...Virginia 22134-5068 MASTER OF MILITARY STUDIES Developing Army Leaders for 21st Century Missions: Teaching Army Leaders Behavioral Science Theories to...REPORT TYPE Student research paper 3. DATES COVERED (FROM - TO) xx-xx-2001 to xx-xx-2002 4. TITLE AND SUBTITLE Developing Army Leaders for 21st Century

Impacts of opinion leaders on social contagions

NASA Astrophysics Data System (ADS)

Liu, Quan-Hui; Lü, Feng-Mao; Zhang, Qian; Tang, Ming; Zhou, Tao

2018-05-01

Opinion leaders are ubiquitous in both online and offline social networks, but the impacts of opinion leaders on social behavior contagions are still not fully understood, especially by using a mathematical model. Here, we generalize the classical Watts threshold model and address the influences of the opinion leaders, where an individual adopts a new behavior if one of his/her opinion leaders adopts the behavior. First, we choose the opinion leaders randomly from all individuals in the network and find that the impacts of opinion leaders make other individuals adopt the behavior more easily. Specifically, the existence of opinion leaders reduces the lowest mean degree of the network required for the global behavior adoption and increases the highest mean degree of the network that the global behavior adoption can occur. Besides, the introduction of opinion leaders accelerates the behavior adoption but does not change the adoption order of individuals. The developed theoretical predictions agree with the simulation results. Second, we randomly choose the opinion leaders from the top h % of the highest degree individuals and find an optimal h % for the network with the lowest mean degree that the global behavior adoption can occur. Meanwhile, the influences of opinion leaders on accelerating the adoption of behaviors become less significant and can even be ignored when reducing the value of h % .

Responsible leader behavior in health sectors.

PubMed

Longest, Beaufort

2017-02-06

Purpose The purpose of this paper is to expand attention to responsible leader behavior in the world's health sectors by explaining how this concept applies to health sectors, considering why health sector leaders should behave responsibly, reviewing how they can do so, and asserting potential impact through an applied example. Design/methodology/approach This paper is a viewpoint, reflecting conceptualizations rooted in leadership literature which are then specifically applied to health sectors. A definition of responsible leader behavior is affirmed and applied specifically in health sectors. Conceptualizations and viewpoints about practice of responsible leader behavior in health sectors and potential consequences are then discussed and asserted. Findings Leadership failures and debacles found in health, but more so in other sectors, have led leadership researchers to offer insights, many of them empirical, into the challenges of leadership especially by more clearly delineating responsible leader behavior. Practical implications Much of what has been learned in the research about responsible leader behavior offers pathways for health sector leaders to more fully practice responsible leadership. Social implications This paper asserts and provides a supporting example that greater levels of responsible leader behavior in health sectors hold potentially important societal benefits. Originality/value This paper is the first to apply emerging conceptualizations and early empirical findings about responsible leader behavior specifically to leaders in health sectors.

76 FR 16765 - Leader One Energy, LLC; Notice of Availability of the Environmental Assessment for the Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-25

... Storage Project The staff of the Federal Energy Regulatory Commission (FERC or Commission) has prepared an environmental assessment (EA) for the Leader One Gas Storage Project proposed by Leader One Energy, LLC (Leader... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP11-33-000] Leader One...

Preparing School Leaders to Serve as Agents for Social Transformation

ERIC Educational Resources Information Center

Brown, Kathleen M.

2010-01-01

The major priorities that should guide leadership education in preparing leaders for their work of leading schools in a democratic society are: (1) Teaching leaders to understand the inequities of society; (2) Teaching leaders to serve as agents for social transformation; and (3) Teaching leaders to help each and every student learn and succeed.…

The Importance of Volunteer Leaders: An Assessment of Volunteer Leader Competencies Following Volunteer Leader Identification and Training

ERIC Educational Resources Information Center

Morrison, Carley Calico

2017-01-01

Volunteer leaders are an underutilized resource in nonprofit organizations. However, as volunteer directors are stretched to their capacity, others in the organization must provide leadership to volunteers. One way for nonprofit organizations to increase their capacity is to develop the leadership skills of identified volunteer leaders. Because…

Evidence for positive selection and recombination hotspots in Deformed wing virus (DWV).

PubMed

Dalmon, A; Desbiez, C; Coulon, M; Thomasson, M; Le Conte, Y; Alaux, C; Vallon, J; Moury, B

2017-01-25

Deformed wing virus (DWV) is considered one of the most damaging pests in honey bees since the spread of its vector, Varroa destructor. In this study, we sequenced the whole genomes of two virus isolates and studied the evolutionary forces that act on DWV genomes. The isolate from a Varroa-tolerant bee colony was characterized by three recombination breakpoints between DWV and the closely related Varroa destructor virus-1 (VDV-1), whereas the variant from the colony using conventional Varroa management was similar to the originally described DWV. From the complete sequence dataset, nine independent DWV-VDV-1 recombination breakpoints were detected, and recombination hotspots were found in the 5' untranslated region (5' UTR) and the conserved region encoding the helicase. Partial sequencing of the 5' UTR and helicase-encoding region in 41 virus isolates suggested that most of the French isolates were recombinants. By applying different methods based on the ratio between non-synonymous (dN) and synonymous (dS) substitution rates, we identified four positions that showed evidence of positive selection. Three of these positions were in the putative leader protein (Lp), and one was in the polymerase. These findings raise the question of the putative role of the Lp in viral evolution.

Cloning and sequence analysis of Galleria mellonella juvenile hormone binding protein--a search for ancestors and relatives.

PubMed

Rodriguez Parkitna, Jan M; Ozyhar, Andrzej; Wiśniewski, Jacek R; Kochman, Marian

2002-09-01

Juvenile hormone binding proteins (JHBPs) serve as specific carriers of juvenile hormone (JH) in insect hemolymph. As shown in this report, Galleria mellonella JHBP is encoded by a cDNA of 1063 nucleotides. The pre-protein consists of 245 amino acids with a 20 amino acid leader sequence. The concentration of the JHBP mRNA reaches a maximum on the third day of the last larval instar, and decreases five-fold towards pupation. Comparison of amino acid sequences of JHBPs from Bombyx mori, Heliothis virescens, Manduca sexta and G. mellonella shows that 57 positions out of 226 are occupied by identical amino acids. A phylogeny tree was constructed from 32 proteins, which function could be associated to JH. It has three major branches: (i) ligand binding domains of nuclear receptors, (ii) JHBPs and JH esterases (JHEs), and (iii) hypothetical proteins found in Drosophila melanogaster genome. Despite the close positioning of JHEs and JHBPs on the tree, which probably arises from the presence of a common JH binding motif, these proteins are unlikely to belong to the same family. Detailed analysis of the secondary structure modeling shows that JHBPs may contain a beta-barrel motif flanked by alpha-helices and thus be evolutionary related to the same superfamily as calycins.

Identification of an Internal Ribosome Entry Segment in the 5′ Region of the Mouse VL30 Retrotransposon and Its Use in the Development of Retroviral Vectors

PubMed Central

López-Lastra, Marcelo; Ulrici, Sandrine; Gabus, Caroline; Darlix, Jean-Luc

1999-01-01

Mouse virus-like 30S RNAs (VL30m) constitute a family of retrotransposons, present at 100 to 200 copies, dispersed in the mouse genome. They display little sequence homology to Moloney murine leukemia virus (MoMLV), do not encode virus-like proteins, and have not been implicated in retroviral carcinogenesis. However, VL30 RNAs are efficiently packaged into MLV particles that are propagated in cell culture. In this study, we addressed whether the 5′ region of VL30m could replace the 5′ leader of MoMLV functionally in a recombinant vector construct. Our data confirm that the putative packaging sequence of VL30 is located within the 5′ region (nucleotides 362 to 1149 with respect to the cap structure) and that it can replace the packaging sequence of MoMLV. We also show that VL30m contains an internal ribosome entry segment (IRES) in the 5′ region, as do MoMLV, Friend murine leukemia virus, Harvey murine sarcoma virus, and avian reticuloendotheliosis virus type A. Our data show that both the packaging and IRES functions of the 5′ region of VL30m RNA can be efficiently used to develop retrotransposon-based vectors. PMID:10482590

Identification of an internal ribosome entry segment in the 5' region of the mouse VL30 retrotransposon and its use in the development of retroviral vectors.

PubMed

López-Lastra, M; Ulrici, S; Gabus, C; Darlix, J L

1999-10-01

Mouse virus-like 30S RNAs (VL30m) constitute a family of retrotransposons, present at 100 to 200 copies, dispersed in the mouse genome. They display little sequence homology to Moloney murine leukemia virus (MoMLV), do not encode virus-like proteins, and have not been implicated in retroviral carcinogenesis. However, VL30 RNAs are efficiently packaged into MLV particles that are propagated in cell culture. In this study, we addressed whether the 5' region of VL30m could replace the 5' leader of MoMLV functionally in a recombinant vector construct. Our data confirm that the putative packaging sequence of VL30 is located within the 5' region (nucleotides 362 to 1149 with respect to the cap structure) and that it can replace the packaging sequence of MoMLV. We also show that VL30m contains an internal ribosome entry segment (IRES) in the 5' region, as do MoMLV, Friend murine leukemia virus, Harvey murine sarcoma virus, and avian reticuloendotheliosis virus type A. Our data show that both the packaging and IRES functions of the 5' region of VL30m RNA can be efficiently used to develop retrotransposon-based vectors.

Molecular cloning of an inducible serine esterase gene from human cytotoxic lymphocytes.

PubMed Central

Trapani, J A; Klein, J L; White, P C; Dupont, B

1988-01-01

A cDNA clone encoding a human serine esterase gene was isolated from a library constructed from poly(A)+ RNA of allogeneically stimulated, interleukin 2-expanded peripheral blood mononuclear cells. The clone, designated HSE26.1, represents a full-length copy of a 0.9-kilobase mRNA present in human cytotoxic cells but absent from a wide variety of noncytotoxic cell lines. Clone HSE26.1 contains an 892-base-pair sequence, including a single 741-base-pair open reading frame encoding a putative 247-residue polypeptide. The first 20 amino acids of the polypeptide form a leader sequence. The mature protein is predicted to have an unglycosylated Mr of approximately equal to 26,000 and contains a single potential site for N-linked glycosylation. The nucleotide and predicted amino acid sequences of clone HSE26.1 are homologous with all murine and human serine esterases cloned thus far but are most similar to mouse granzyme B (70% nucleotide and 68% amino acid identity). HSE26.1 protein is expressed weakly in unstimulated peripheral blood mononuclear cells but is strongly induced within 6-hr incubation in medium containing phytohemagglutinin. The data suggest that the protein encoded by HSE26.1 plays a role in cell-mediated cytotoxicity. Images PMID:3261871

CGAT: a model for immersive personalized training in computational genomics.

PubMed

Sims, David; Ponting, Chris P; Heger, Andreas

2016-01-01

How should the next generation of genomics scientists be trained while simultaneously pursuing high quality and diverse research? CGAT, the Computational Genomics Analysis and Training programme, was set up in 2010 by the UK Medical Research Council to complement its investment in next-generation sequencing capacity. CGAT was conceived around the twin goals of training future leaders in genome biology and medicine, and providing much needed capacity to UK science for analysing genome scale data sets. Here we outline the training programme employed by CGAT and describe how it dovetails with collaborative research projects to launch scientists on the road towards independent research careers in genomics. © The Author 2015. Published by Oxford University Press.

2009 Epigenetics Gordon Research Conference (August 9 - 14, 2009)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeanie Lee

Epigenetics refers to the study of heritable changes in genome function that occur without a change in primary DNA sequence. The 2009 Gordon Conference in Epigenetics will feature discussion of various epigenetic phenomena, emerging understanding of their underlying mechanisms, and the growing appreciation that human, animal, and plant health all depend on proper epigenetic control. Special emphasis will be placed on genome-environment interactions particularly as they relate to human disease. Towards improving knowledge of molecular mechanisms, the conference will feature international leaders studying the roles of higher order chromatin structure, noncoding RNA, repeat elements, nuclear organization, and morphogenic evolution. Traditionalmore » and new model organisms are selected from plants, fungi, and metazoans.« less

Beyond the classroom: nurse leader preparation and practices.

PubMed

O'Connor, Mary

2011-01-01

Formal academic education and experience as a nurse are established preparation for the chief nurse executive (CNE) or upcoming nurse leaders. This article proposes that the nurse leader must build on these fundamentals through self-discipline, lifelong learning, and practice. Three critical ingredients are discussed to guide the nurse leader on a life/career for the CNE and the nurse leader at every level. These include fostering relationships, feeding intellectual curiosity, and engaging in self-care practices. These indispensable ingredients of the successful nurse leader serve as an augmentation to formal education and experience for the nurse aspiring to reach the CNE level and beyond as well as for the current CNE mentoring future leaders.

How Can the Skills of Early Years Leaders Support Other Leaders in a Primary School Setting?

ERIC Educational Resources Information Center

Mistry, Malini; Sood, Krishan

2017-01-01

This study investigated the leadership skills Early Years leaders demonstrated through their daily practice of teaching, assessing and teamwork within their setting. It explored how revealing the potential of Early Years leaders could have a positive impact on the leadership practice of other leaders in the same setting to improve pupil outcomes.…

A Logic Model for Coaching Experienced Rural Leaders: Lessons from Year One of a Pilot Program

ERIC Educational Resources Information Center

Lindle, Jane Clark; Della Sala, Matthew R.; Reese, Kenyae L.; Klar, Hans W.; Knoeppel, Robert Charles; Buskey, Frederick C.

2017-01-01

Rural schools dominate the United States, yet scant research exists on rural school leaders' development. Urban districts can transfer leaders to different locations, but rural districts, with few school sites, need leaders who stay and adapt to changing conditions. Mid-career rural leaders require a refreshed set of skills to carry school…

On angry leaders and agreeable followers. How leaders' emotions and followers' personalities shape motivation and team performance.

PubMed

Van Kleef, Gerben A; Homan, Astrid C; Beersma, Bianca; van Knippenberg, Daan

2010-12-01

Do followers perform better when their leader expresses anger or when their leader expresses happiness? We propose that this depends on the follower's level of agreeableness. Anger is associated with hostility and conflict-states that are at odds with agreeable individuals' goals. Happiness facilitates affiliation and positive relations-states that are in line with agreeable individuals' goals. Accordingly, the two studies we conducted showed that agreeableness moderates the effects of a leader's emotional displays. In a scenario study, participants with lower levels of agreeableness responded more favorably to an angry leader, whereas participants with higher levels of agreeableness responded more favorably to a neutral leader. In an experiment involving four-person teams, teams composed of participants with lower average levels of agreeableness performed better when their leader expressed anger, whereas teams composed of participants with higher average levels of agreeableness performed better when their leader expressed happiness. Team performance was mediated by experienced workload, which was highest among agreeable followers with an angry leader. Besides having important practical implications, the findings shed new light on the fundamental question of how emotional expressions regulate social behavior.

Succession planning for the future through an academic-practice partnership: a nursing administration master's program for emerging nurse leaders.

PubMed

Sherman, Rose; Dyess, Susan; Hannah, Ed; Prestia, Angela

2013-01-01

A global nursing leadership shortage is projected by the end of this decade. There is an urgent need to begin developing emerging nurse leaders now. This article describes the work of an academic-practice partnership collaborative of nurse leaders. The goal of the partnership is to develop and promote an innovative enhanced nursing administration master's program targeted to young emerging nurse leaders, who have not yet moved into formal leadership roles. An action research design is being used in program development and evaluation. Qualities needed by emerging leaders identified through research included a need to be politically astute, competency with business skills required of nurse leaders today, comfort with ambiguity, use of a caring approach, and leadership from a posture of innovation. The current curriculum was revised to include clinical immersion with a nurse leader from the first semester in the program, a change from all online to online/hybrid courses, innovative assignments, and a strong mentorship component. Eighteen young emerging nurse leaders began the program in January 2012. Early outcomes are positive. The emerging nurse leaders may be uniquely positioned, given the right skills sets, to be nurse leaders in the new age.

Characteristics of nurse leaders in hospitals in the U.S.A. from 1992 to 2008.

PubMed

Westphal, Judith A

2012-10-01

Describe the nurse leader workforce in hospitals in the USA over time by exploring three research questions: (1) What are the characteristics of the nurse leader workforce in U.S. hospitals? (2) How does the nurse leader workforce change over time? (3) How do nurses in executive positions (administrators) differ from nurses in first-line supervisory positions (supervisors)? Effective nurse leaders use management skills to ensure safe patient care in hospitals in the USA. Changes in the nurse leader workforce have an impact on patient care. non-experimental design was used to explore the characteristics of 10,150 nurse leaders using the 1992, 1996, 2000, 2004 and 2008 National Sample Surveys of Registered Nurses. Number of masters and doctorally prepared nurse leaders increased from 14.5% to 23.2% along with an increase in mean age. A 30% decrease in the number of nurses in leadership positions was found. Male nurses reported significantly higher salaries P < 0.000. Nurse leaders are older and have achieved higher educational degrees. Salary disparities based on gender still prevail. Implications for nursing management  Identifying and developing future leaders with necessary skills and competencies is critical for organizational success. © 2012 Blackwell Publishing Ltd.

Leader-team complementarity: Exploring the interactive effects of leader personality traits and team power distance values on team processes and performance.

PubMed

Hu, Jia; Judge, Timothy A

2017-06-01

Integrating the leader trait perspective with dominance complementarity theory, we propose team power distance as an important boundary condition for the indirect impact of leader extraversion, agreeableness, and conscientiousness on team performance through a team's potency beliefs and through relational identification with the leader. Using time-lagged, 3-source data from 71 teams, we found that leader extraversion had a positive indirect impact on team in-role and extrarole performance through relational identification, but only for high power distance teams; leader conscientiousness had a positive influence on team in-role performance through team potency, but only for high power distance teams; and leader agreeableness had a positive effect on team in-role and extrarole performance via relational identification and on team in-role performance via team potency, but only for low power distance teams. The findings address prior inconsistencies regarding the relationships between leader traits and team effectiveness, identify an important boundary condition and key team processes that bridge the links, and provide a deeper understanding of the role of leader traits in teams. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Analysis multi-agent with precense of the leader

NASA Astrophysics Data System (ADS)

Achmadi, Sentot; Marjono, Miswanto

2017-12-01

The phenomenon of swarm is a natural phenomenon that is often done by a collection of living things in the form of motion from one place to another. By clustering, a group of animals can increase their effectiveness in food search and avoid predators. A group of geese also performs a swarm phenomenon when flying and forms an inverted V-formation with one of the geese acting as a leader. Each flying track of members of the geese group always follows the leader's path at a certain distance. This article discusses the mathematical modeling of the swarm phenomenon, which is the optimal tracking control for multi-agent model with the influence of the leader in the 2-dimensional space. The leader in this model is intended to track the specified path. Firstly, the leader's motion control is to follow the predetermined path using the Tracking Error Dynamic method. Then, the path from the leader is used to design the motion control of each agent to track the leader's path at a certain distance. The result of numerical simulation shows that the leader trajectory can track the specified path. Similarly, the motion of each agent can trace and follow the leader's path.

Nursing Informatics Competencies: Psychometric Validation, Dissemination, and Maintenance of Self-Assessment Tool for Nurse Leaders.

PubMed

Collins, Sarah

2016-01-01

Due to rapid advances in technology, HIT competencies for nursing leaders require frequent attention and updating from experts in the field to ensure relevance to nursing leaders' work. This workshop will target nursing informatics researchers and leaders to: 1) learn methods and findings from a study validating a Self-Assessment Scale for Nursing Informatics Competencies for Nurse Leaders, 2) generate awareness of the Self-Assessment scale, 3) discuss strategies for maintenance of competencies overtime and 4) identify strategies to engage nursing leaders in this pursuit.

Locus of control, sources of motivation, and mental boundaries as antecedents of leader-member exchange quality.

PubMed

Barbuto, John E; Finch, Weltmer Dayna; Pennisi, Lisa A

2010-02-01

In this study were examined leaders' and members' scores on locus of control, sources of motivation, and mental boundaries to predict the quality of leader-member exchanges. 80 elected officials and their 388 direct reports were sampled in a field study. Analysis indicated followers' scores on locus of control, leaders' scores of self-concept internal motivation, leaders' scores on locus of control, and followers' rated goal-internalization motivation were positively related to leader-member exchanges. Implications and directions for research are discussed.

Lactobacillus buchneri Genotyping on the Basis of Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) Locus Diversity

PubMed Central

Briner, Alexandra E.

2014-01-01

Clustered regularly interspaced short palindromic repeats (CRISPR) in combination with associated sequences (cas) constitute the CRISPR-Cas immune system, which uptakes DNA from invasive genetic elements as novel “spacers” that provide a genetic record of immunization events. We investigated the potential of CRISPR-based genotyping of Lactobacillus buchneri, a species relevant for commercial silage, bioethanol, and vegetable fermentations. Upon investigating the occurrence and diversity of CRISPR-Cas systems in Lactobacillus buchneri genomes, we observed a ubiquitous occurrence of CRISPR arrays containing a 36-nucleotide (nt) type II-A CRISPR locus adjacent to four cas genes, including the universal cas1 and cas2 genes and the type II signature gene cas9. Comparative analysis of CRISPR spacer content in 26 L. buchneri pickle fermentation isolates associated with spoilage revealed 10 unique locus genotypes that contained between 9 and 29 variable spacers. We observed a set of conserved spacers at the ancestral end, reflecting a common origin, as well as leader-end polymorphisms, reflecting recent divergence. Some of these spacers showed perfect identity with phage sequences, and many spacers showed homology to Lactobacillus plasmid sequences. Following a comparative analysis of sequences immediately flanking protospacers that matched CRISPR spacers, we identified a novel putative protospacer-adjacent motif (PAM), 5′-AAAA-3′. Overall, these findings suggest that type II-A CRISPR-Cas systems are valuable for genotyping of L. buchneri. PMID:24271175

Genomic Sequencing Procedure Microcosting Analysis and Health Economic Cost-Impact Analysis: A Report of the Association for Molecular Pathology.

PubMed

Sabatini, Linda M; Mathews, Charles; Ptak, Devon; Doshi, Shivang; Tynan, Katherine; Hegde, Madhuri R; Burke, Tara L; Bossler, Aaron D

2016-05-01

The increasing use of advanced nucleic acid sequencing technologies for clinical diagnostics and therapeutics has made vital understanding the costs of performing these procedures and their value to patients, providers, and payers. The Association for Molecular Pathology invested in a cost and value analysis of specific genomic sequencing procedures (GSPs) newly coded by the American Medical Association Current Procedural Terminology Editorial Panel. Cost data and work effort, including the development and use of data analysis pipelines, were gathered from representative laboratories currently performing these GSPs. Results were aggregated to generate representative cost ranges given the complexity and variability of performing the tests. Cost-impact models for three clinical scenarios were generated with assistance from key opinion leaders: impact of using a targeted gene panel in optimizing care for patients with advanced non-small-cell lung cancer, use of a targeted gene panel in the diagnosis and management of patients with sensorineural hearing loss, and exome sequencing in the diagnosis and management of children with neurodevelopmental disorders of unknown genetic etiology. Each model demonstrated value by either reducing health care costs or identifying appropriate care pathways. The templates generated will aid laboratories in assessing their individual costs, considering the value structure in their own patient populations, and contributing their data to the ongoing dialogue regarding the impact of GSPs on improving patient care. Copyright © 2016 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Putative Monofunctional Type I Polyketide Synthase Units: A Dinoflagellate-Specific Feature?

PubMed Central

Eichholz, Karsten; Beszteri, Bánk; John, Uwe

2012-01-01

Marine dinoflagellates (alveolata) are microalgae of which some cause harmful algal blooms and produce a broad variety of most likely polyketide synthesis derived phycotoxins. Recently, novel polyketide synthesase (PKS) transcripts have been described from the Florida red tide dinoflagellate Karenia brevis (gymnodiniales) which are evolutionarily related to Type I PKS but were apparently expressed as monofunctional proteins, a feature typical of Type II PKS. Here, we investigated expression units of PKS I-like sequences in Alexandrium ostenfeldii (gonyaulacales) and Heterocapsa triquetra (peridiniales) at the transcript and protein level. The five full length transcripts we obtained were all characterized by polyadenylation, a 3′ UTR and the dinoflagellate specific spliced leader sequence at the 5′end. Each of the five transcripts encoded a single ketoacylsynthase (KS) domain showing high similarity to K. brevis KS sequences. The monofunctional structure was also confirmed using dinoflagellate specific KS antibodies in Western Blots. In a maximum likelihood phylogenetic analysis of KS domains from diverse PKSs, dinoflagellate KSs formed a clade placed well within the protist Type I PKS clade between apicomplexa, haptophytes and chlorophytes. These findings indicate that the atypical PKS I structure, i.e., expression as putative monofunctional units, might be a dinoflagellate specific feature. In addition, the sequenced transcripts harbored a previously unknown, apparently dinoflagellate specific conserved N-terminal domain. We discuss the implications of this novel region with regard to the putative monofunctional organization of Type I PKS in dinoflagellates. PMID:23139807

Cloning a Chymotrypsin-Like 1 (CTRL-1) Protease cDNA from the Jellyfish Nemopilema nomurai

PubMed Central

Heo, Yunwi; Kwon, Young Chul; Bae, Seong Kyeong; Hwang, Duhyeon; Yang, Hye Ryeon; Choudhary, Indu; Lee, Hyunkyoung; Yum, Seungshic; Shin, Kyoungsoon; Yoon, Won Duk; Kang, Changkeun; Kim, Euikyung

2016-01-01

An enzyme in a nematocyst extract of the Nemopilema nomurai jellyfish, caught off the coast of the Republic of Korea, catalyzed the cleavage of chymotrypsin substrate in an amidolytic kinetic assay, and this activity was inhibited by the serine protease inhibitor, phenylmethanesulfonyl fluoride. We isolated the full-length cDNA sequence of this enzyme, which contains 850 nucleotides, with an open reading frame of 801 encoding 266 amino acids. A blast analysis of the deduced amino acid sequence showed 41% identity with human chymotrypsin-like (CTRL) and the CTRL-1 precursor. Therefore, we designated this enzyme N. nomurai CTRL-1. The primary structure of N. nomurai CTRL-1 includes a leader peptide and a highly conserved catalytic triad of His69, Asp117, and Ser216. The disulfide bonds of chymotrypsin and the substrate-binding sites are highly conserved compared with the CTRLs of other species, including mammalian species. Nemopilema nomurai CTRL-1 is evolutionarily more closely related to Actinopterygii than to Scyphozoan (Aurelia aurita) or Hydrozoan (Hydra vulgaris). The N. nomurai CTRL1 was amplified from the genomic DNA with PCR using specific primers designed based on the full-length cDNA, and then sequenced. The N. nomurai CTRL1 gene contains 2434 nucleotides and four distinct exons. The 5′ donor splice (GT) and 3′ acceptor splice sequences (AG) are wholly conserved. This is the first report of the CTRL1 gene and cDNA structures in the jellyfish N. nomurai. PMID:27399771

Cloning a Chymotrypsin-Like 1 (CTRL-1) Protease cDNA from the Jellyfish Nemopilema nomurai.

PubMed

Heo, Yunwi; Kwon, Young Chul; Bae, Seong Kyeong; Hwang, Duhyeon; Yang, Hye Ryeon; Choudhary, Indu; Lee, Hyunkyoung; Yum, Seungshic; Shin, Kyoungsoon; Yoon, Won Duk; Kang, Changkeun; Kim, Euikyung

2016-07-05

An enzyme in a nematocyst extract of the Nemopilema nomurai jellyfish, caught off the coast of the Republic of Korea, catalyzed the cleavage of chymotrypsin substrate in an amidolytic kinetic assay, and this activity was inhibited by the serine protease inhibitor, phenylmethanesulfonyl fluoride. We isolated the full-length cDNA sequence of this enzyme, which contains 850 nucleotides, with an open reading frame of 801 encoding 266 amino acids. A blast analysis of the deduced amino acid sequence showed 41% identity with human chymotrypsin-like (CTRL) and the CTRL-1 precursor. Therefore, we designated this enzyme N. nomurai CTRL-1. The primary structure of N. nomurai CTRL-1 includes a leader peptide and a highly conserved catalytic triad of His(69), Asp(117), and Ser(216). The disulfide bonds of chymotrypsin and the substrate-binding sites are highly conserved compared with the CTRLs of other species, including mammalian species. Nemopilema nomurai CTRL-1 is evolutionarily more closely related to Actinopterygii than to Scyphozoan (Aurelia aurita) or Hydrozoan (Hydra vulgaris). The N. nomurai CTRL1 was amplified from the genomic DNA with PCR using specific primers designed based on the full-length cDNA, and then sequenced. The N. nomurai CTRL1 gene contains 2434 nucleotides and four distinct exons. The 5' donor splice (GT) and 3' acceptor splice sequences (AG) are wholly conserved. This is the first report of the CTRL1 gene and cDNA structures in the jellyfish N. nomurai.

Sequence and structure determinants of Drosophila Hsp70 mRNA translation: 5'UTR secondary structure specifically inhibits heat shock protein mRNA translation.

PubMed Central

Hess, M A; Duncan, R F

1996-01-01

Preferential translation of Drosophila heat shock protein 70 (Hsp70) mRNA requires only the 5'-untranslated region (5'-UTR). The sequence of this region suggests that it has relatively little secondary structure, which may facilitate efficient protein synthesis initiation. To determine whether minimal 5'-UTR secondary structure is required for preferential translation during heat shock, the effect of introducing stem-loops into the Hsp70 mRNA 5'-UTR was measured. Stem-loops of -11 kcal/mol abolished translation during heat shock, but did not reduce translation in non-heat shocked cells. A -22 kcal/mol stem-loop was required to comparably inhibit translation during growth at normal temperatures. To investigate whether specific sequence elements are also required for efficient preferential translation, deletion and mutation analyses were conducted in a truncated Hsp70 5'-UTR containing only the cap-proximal and AUG-proximal segments. Linker-scanner mutations in the cap-proximal segment (+1 to +37) did not impair translation. Re-ordering the segments reduced mRNA translational efficiency by 50%. Deleting the AUG-proximal segment severely inhibited translation. A 5-extension of the full-length leader specifically impaired heat shock translation. These results indicate that heat shock reduces the capacity to unwind 5-UTR secondary structure, allowing only mRNAs with minimal 5'-UTR secondary structure to be efficiently translated. A function for specific sequences is also suggested. PMID:8710519

[Sequencing and analysis of complete genome of rabies viruses isolated from Chinese Ferret-Badger and dog in Zhejiang province].

PubMed

Lei, Yong-Liang; Wang, Xiao-Guang; Tao, Xiao-Yan; Li, Hao; Meng, Sheng-Li; Chen, Xiu-Ying; Liu, Fu-Ming; Ye, Bi-Feng; Tang, Qing

2010-01-01

Based on sequencing the full-length genomes of four Chinese Ferret-Badger and dog, we analyze the properties of rabies viruses genetic variation in molecular level, get the information about rabies viruses prevalence and variation in Zhejiang, and enrich the genome database of rabies viruses street strains isolated from China. Rabies viruses in suckling mice were isolated, overlapped fragments were amplified by RT-PCR and full-length genomes were assembled to analyze the nucleotide and deduced protein similarities and phylogenetic analyses from Chinese Ferret-Badger, dog, sika deer, vole, used vaccine strain were determined. The four full-length genomes were sequenced completely and had the same genetic structure with the length of 11, 923 nts or 11, 925 nts including 58 nts-Leader, 1353 nts-NP, 894 nts-PP, 609 nts-MP, 1575 nts-GP, 6386 nts-LP, and 2, 5, 5 nts- intergenic regions(IGRs), 423 nts-Pseudogene-like sequence (psi), 70 nts-Trailer. The four full-length genomes were in accordance with the properties of Rhabdoviridae Lyssa virus by BLAST and multi-sequence alignment. The nucleotide and amino acid sequences among Chinese strains had the highest similarity, especially among animals of the same species. Of the four full-length genomes, the similarity in amino acid level was dramatically higher than that in nucleotide level, so the nucleotide mutations happened in these four genomes were most synonymous mutations. Compared with the reference rabies viruses, the lengths of the five protein coding regions had no change, no recombination, only with a few point mutations. It was evident that the five proteins appeared to be stable. The variation sites and types of the four genomes were similar to the reference vaccine or street strains. And the four strains were genotype 1 according to the multi-sequence and phylogenetic analyses, which possessed the distinct district characteristics of China. Therefore, these four rabies viruses are likely to be street viruses already existing in the natural world.

Retrieval of Missing Spliced Leader in Dinoflagellates

PubMed Central

Zhang, Huan; Lin, Senjie

2009-01-01

Spliced leader (SL) trans-splicing has recently been shown to be a common mRNA processing mechanism in dinoflagellates, in which a short (22-nt) sequence, DCCGUAGCCAUUUUGGCUCAAG (D = U, A, or G), is transplanted from the 5′-end of a small non-coding RNA (SL RNA) to the 5′ end of mRNA molecules. The widespread existence of the mechanism in dinoflagellates has been demonstrated by detection of this SL (DinoSL) in a wide phylogenetic range of dinoflagellates. Furthermore, the presence of DinoSL in the transcripts of highly diverse groups of nuclear-encoded genes has led us to postulate that SL trans-splicing is universal in dinoflagellate nuclear genome. However, some observations inconsistent to this postulation have been reported, exemplified by a recent article reporting apparent absence of DinoSL in the transcripts of some nuclear-encoded genes in Amphidinium carterae. Absence of SL in these gene transcripts would have important implication on gene regulation in dinoflagellates and utility of DinoSL as a universal dinoflagellate-specific primer to study dinoflagellate transcriptomics. In this study, we re-examined transcripts of these genes and found that all of them actually contained DinoSL. Therefore, results to date are consistent to our initial postulation that DinoSL occurs in all dinoflagellate nuclear-encoded mRNAs. PMID:19122814

Genomic overview of mRNA 5′-leader trans-splicing in the ascidian Ciona intestinalis

PubMed Central

Satou, Yutaka; Hamaguchi, Makoto; Takeuchi, Keisuke; Hastings, Kenneth E. M.; Satoh, Nori

2006-01-01

Although spliced leader (SL) trans-splicing in the chordates was discovered in the tunicate Ciona intestinalis there has been no genomic overview analysis of the extent of trans-splicing or the make-up of the trans-spliced and non-trans-spliced gene populations of this model organism. Here we report such an analysis for Ciona based on the oligo-capping full-length cDNA approach. We randomly sampled 2078 5′-full-length ESTs representing 668 genes, or 4.2% of the entire genome. Our results indicate that Ciona contains a single major SL, which is efficiently trans-spliced to mRNAs transcribed from a specific set of genes representing ∼50% of the total number of expressed genes, and that individual trans-spliced mRNA species are, on average, 2–3-fold less abundant than non-trans-spliced mRNA species. Our results also identify a relationship between trans-splicing status and gene functional classification; ribosomal protein genes fall predominantly into the non-trans-spliced category. In addition, our data provide the first evidence for the occurrence of polycistronic transcription in Ciona. An interesting feature of the Ciona polycistronic transcription units is that the great majority entirely lack intercistronic sequences. PMID:16822859

Role of the open reading frames of Rous sarcoma virus leader RNA in translation and genome packaging.

PubMed Central

Donzé, O; Spahr, P F

1992-01-01

The Rous sarcoma virus (RSV) RNA leader sequence carries three open reading frames (uORFs) upstream of the AUG initiator of the gag gene. We studied, in vivo, the role of these uORFs by changing two or three nucleotides of the three AUGs or by deleting the first uORF. Our results show that (i) unlike most previously characterized uORFs, which decrease translation, the first uORF (AUG1) of RSV acts as an enhancer of translation, since absence of the first AUG decreased translation; AUG3 also modulates translation, probably by interfering with scanning ribosomes as described for other upstream ORFs, and mutation of AUG2 had no effect on translation. (ii) Mutation of each of the upstream AUGs lowered the infectivity of progeny virions. (iii) Unexpectedly, mutation of AUG1 and/or AUG3 dramatically reduced RNA packaging by 50-to 100-fold, unlike mutation of AUG2 which did not alter RNA packaging efficiency. Additional mutants in the vicinity of uORF1 and uORF3 were constructed in order to elucidate the mechanism by which uORFs affect RNA packaging: a translation model requiring uORFs 1 and 3, and involving ribosome pausing at AUG 3 is discussed. Images PMID:1327749

Truncation of a P1 leader proteinase facilitates potyvirus replication in a non-permissive host.

PubMed

Shan, Hongying; Pasin, Fabio; Tzanetakis, Ioannis E; Simón-Mateo, Carmen; García, Juan Antonio; Rodamilans, Bernardo

2018-06-01

The Potyviridae family is a major group of plant viruses that includes c. 200 species, most of which have narrow host ranges. The potyvirid P1 leader proteinase self-cleaves from the remainder of the viral polyprotein and shows large sequence variability linked to host adaptation. P1 proteins can be classified as Type A or Type B on the basis, amongst other things, of their dependence or not on a host factor to develop their protease activity. In this work, we studied Type A proteases from the Potyviridae family, characterizing their host factor requirements. Our in vitro cleavage analyses of potyvirid P1 proteases showed that the N-terminal domain is relevant for host factor interaction and suggested that the C-terminal domain is also involved. In the absence of plant factors, the N-terminal end of Plum pox virus P1 antagonizes protease self-processing. We performed extended deletion mutagenesis analysis to define the N-terminal antagonistic domain of P1. In viral infections, removal of the P1 protease antagonistic domain led to a gain-of-function phenotype, strongly increasing local infection in a non-permissive host. Altogether, our results shed new insights into the adaptation and evolution of potyvirids. © 2017 BSPP AND JOHN WILEY & SONS LTD.

Spliced leader RNA trans-splicing discovered in copepods

NASA Astrophysics Data System (ADS)

Yang, Feifei; Xu, Donghui; Zhuang, Yunyun; Yi, Xiaoyan; Huang, Yousong; Chen, Hongju; Lin, Senjie; Campbell, David A.; Sturm, Nancy R.; Liu, Guangxing; Zhang, Huan

2015-12-01

Copepods are one of the most abundant metazoans in the marine ecosystem, constituting a critical link in aquatic food webs and contributing significantly to the global carbon budget, yet molecular mechanisms of their gene expression are not well understood. Here we report the detection of spliced leader (SL) trans-splicing in calanoid copepods. We have examined nine species of wild-caught copepods from Jiaozhou Bay, China that represent the major families of the calanoids. All these species contained a common 46-nt SL (CopepodSL). We further determined the size of CopepodSL precursor RNA (slRNA; 108-158 nt) through genomic analysis and 3‧-RACE technique, which was confirmed by RNA blot analysis. Structure modeling showed that the copepod slRNA folded into typical slRNA secondary structures. Using a CopepodSL-based primer set, we selectively enriched and sequenced copepod full-length cDNAs, which led to the characterization of copepod transcripts and the cataloging of the complete set of 79 eukaryotic cytoplasmic ribosomal proteins (cRPs) for a single copepod species. We uncovered the SL trans-splicing in copepod natural populations, and demonstrated that CopepodSL was a sensitive and specific tool for copepod transcriptomic studies at both the individual and population levels and that it would be useful for metatranscriptomic analysis of copepods.

Optical observations of electrical activity in cloud discharges

NASA Astrophysics Data System (ADS)

Vayanganie, S. P. A.; Fernando, M.; Sonnadara, U.; Cooray, V.; Perera, C.

2018-07-01

Temporal variation of the luminosity of seven natural cloud-to-cloud lightning channels were studied, and results were presented. They were recorded by using a high-speed video camera with the speed of 5000 fps (frames per second) and the pixel resolution of 512 × 512 in three locations in Sri Lanka in the tropics. Luminosity variation of the channel with time was obtained by analyzing the image sequences. Recorded video frames together with the luminosity variation were studied to understand the cloud discharge process. Image analysis techniques also used to understand the characteristics of channels. Cloud flashes show more luminosity variability than ground flashes. Most of the time it starts with a leader which do not have stepping process. Channel width and standard deviation of intensity variation across the channel for each cloud flashes was obtained. Brightness variation across the channel shows a Gaussian distribution. The average time duration of the cloud flashes which start with non stepped leader was 180.83 ms. Identified characteristics are matched with the existing models to understand the process of cloud flashes. The fact that cloud discharges are not confined to a single process have been further confirmed from this study. The observations show that cloud flash is a basic lightning discharge which transfers charge between two charge centers without using one specific mechanism.

On the Transition from Initial Leader to Stepped Leader in Negative Cloud-to-ground Lightning

NASA Astrophysics Data System (ADS)

Stolzenburg, M.; Marshall, T. C.; Karunarathne, S.; Orville, R. E.

2017-12-01

High-speed video and electric field change (E-change) data are used to describe the first 5 ms of a natural negative cloud-to-ground (CG) flash. These observations reveal differences in appearance of both the video luminosity and the E-change pulses before the leader transitions to propagating as a negative stepped leader (SL). During the initial breakdown (IB) stage, the initial leader advances intermittently forward in jumps of 78-175 m, at intervals of 100-280 μs, and in separate bursts that are bright for a few 20-μs video frames. The IB pulses accompanying these luminosity bursts have long duration, large amplitude, and a characteristic bipolar shape in nearby E-change observations. In the time between IB pulses, the initial leader is very dim or not visible during the earliest 1-2 ms of the IB stage. Over the next few milliseconds, the leader propagation transitions to an early SL phase, in which the leader tips advance 20-59 m forward at more regular intervals of 40-80 μs during relatively dim and brief steps. In the E-change data, the accompanying SL pulses have very short duration, small amplitude, and are typically unipolar. These data indicate that when the entire initial leader length behind the lower end begins to remain illuminated between bursts, the propagation mode changes from IB bursts to SL steps, and the IB stage ends. Additional differences in initial leader character are evident during the return stroke, as its luminosity speed decreases sharply upon reaching the topmost initial leader section of the channel, and that section of channel does not saturate the video intensity. Results of these analyses support a prior hypothesis that the early initial leader development occurs in the absence of a continuously hot channel, and consequently, the initial leader propagation is unlike the self-propagating advance of the later stepped leader.

Empowerment in nurse leader groups in middle management: a quantitative comparative investigation.

PubMed

Spencer, Caroline; McLaren, Susan

2017-01-01

The aim was to investigate structural empowerment in nurse leaders in middle management positions. Objectives were to determine levels of empowerment of nurse leaders and to compare levels of empowerment between nurse leader groups. Access to formal and informal power, opportunity, resources, information and support are determinants of structural empowerment. Empowerment of nurse leaders in middle management positions is vital given their roles in enabling nursing teams to deliver high-quality care, benefitting both patient and workforce outcomes. Quantitative component of a mixed methods study using survey principles. The Conditions of Work Effectiveness Questionnaire II was distributed to the total population (n = 517) of nurse leaders in an NHS Foundation Trust in England. Nurse leader groups comprised unit leaders (sisters, matrons) and senior staff nurses. Quantitative data entered on spss v 17/18, were analysed using descriptive and inferential statistics. Overall, the unit response rate was 44·1% (n = 228). Levels of total and global empowerment were moderate and moderate to high respectively. Groups did not differ significantly on these parameters or on five elements of total empowerment, but significantly higher scores were found for unit leaders' access to information. Significantly higher scores were found for senior staff nurses on selected aspects of informal power and access to resources, but scores were significantly lower than unit leaders for components of support. A moderately empowered population of nurse leaders differed in relation to access to information, aspects of support, resources and informal power, reflecting differences in roles, spheres of responsibility, hierarchical position and the constraints on empowerment imposed on unit leaders by financial and resource pressures. Empowerment of nurse leaders in middle management is vital in enabling nursing teams to deliver high-quality care. Roles, spheres of responsibility, hierarchical position and constraints imposed by financial and resource pressures influence nurse leader empowerment. Administrative support is needed to sustain practice engagement. © 2016 John Wiley & Sons Ltd.

Health Professions Education Scholarship Unit Leaders as Institutional Entrepreneurs.

PubMed

Varpio, Lara; O'Brien, Bridget; J Durning, Steven; van der Vleuten, Cees; Gruppen, Larry; Ten Cate, Olle; Humphrey-Murto, Susan; Irby, David M; Hamstra, Stanley J; Hu, Wendy

2017-08-01

Health professions education scholarship units (HPESUs) are organizational structures within which a group is substantively engaged in health professions education scholarship. Little research investigates the strategies employed by HPESU administrative leaders to secure and maintain HPESU success. Using institutional entrepreneurship as a theoretical lens, this study asks: Do HPESU administrative leaders act as institutional entrepreneurs (IEs)? This study recontextualizes two preexisting qualitative datasets that comprised interviews with leaders in health professions education in Canada (2011-2012) and Australia and New Zealand (2013-1014). Two researchers iteratively analyzed the data using the institutional entrepreneurship construct until consensus was achieved. A third investigator independently reviewed and contributed to the recontextualized analyses. A summary of the analyses was shared with all authors, and their feedback was incorporated into the final interpretations. HPESU leaders act as IEs in three ways. First, HPESU leaders construct arguments and position statements about how the HPESU resolves an institution's problem(s). This theorization discourse justifies the existence and support of the HPESU. Second, the leaders strategically cultivate relationships with the leader of the institution within which the HPESU sits, the leaders of large academic groups with which the HPESU partners, and the clinician educators who want careers in health professions education. Third, the leaders work to increase the local visibility of the HPESU. Practical insights into how institutional leaders interested in launching an HPESU can harness these findings are discussed.

Career anchors of dentist leaders.

PubMed

Tuononen, Tiina; Lammintakanen, Johanna; Suominen, Anna Liisa

2016-08-01

The work of a health care leader is demanding; in order to cope, leaders need motivation and support. The occurrence of intrinsic factors called career anchors (combination of one's competence, motives and values) could be a contributing factor in dentist leaders' career decisions. The aim of our study was to identify dentist leaders' career anchors and their association to dentist leaders' retention or turnover of the leadership position. Materials were gathered in 2014 via an electronic questionnaire from 156 current (Leaders) or former (Leavers) Finnish dentist leaders. Career anchor evaluation was conducted by the questionnaire and scoring-table taken from Edgar Schein's Career Anchors Self-Assessment. Both the most and the least important career anchors were detected by the highest and lowest scores and their occurrence reported as percentages. Associations between career anchor scores and tendency to stay were analyzed with logistic regression. 'Technical/Functional Competence' and 'Lifestyle' were most frequently reported as the most important and 'Entrepreneurial Creativity' and 'General Managerial Competence' as the least important career anchors. However, a higher level of 'General Managerial Competence' anchor was most significantly associated with staying in a leadership position. Instead, 'Pure Challenge' and 'Lifestyle' decreased the odds to stay. The knowledge of the important and essential career anchors of dentist leaders' and individuals' could perform crucial part in career choices and also in planning education, work opportunities and human resource policies promoting retention of dentist leaders and probably also other health care leaders.

Principals of Effective Schools Are Strong Instructional Leaders.

ERIC Educational Resources Information Center

Jordan, Ian

1986-01-01

Examines research on effective schools and on principals as instructional leaders. Research shows that principals of effective schools are strong instructional leaders. Mention is made of weaknesses found in the research on principals as instructional leaders. (MD)

NREL Wind Leaders Participate in Wind Industry Partnership Summit | News |

Science.gov Websites

NREL NREL Wind Leaders Participate in Wind Industry Partnership Summit NREL Wind Leaders enable innovations needed to advance U.S. wind systems. "The summit brought together leaders from

Psychological competence: the key to leader empowering behaviors.

PubMed

Havaei, Farinaz; Dahinten, V Susan; MacPhee, Maura

2014-05-01

The aim of this study was to examine the effects of specific cognitions or aspects of psychological empowerment on 5 major aspects of leader empowering behaviors. Leader empowering behaviors are linked to important employee outcomes such as work effectiveness. Psychologically empowered leaders are known to use more empowering behaviors in their practice. There is limited research examining what aspects of psychological empowerment are most associated with different aspects of leader empowering behaviors. Data from a sample of 103 frontline and midlevel nurse leaders were analyzed after they participated in a leadership development program. Psychological competence was the strongest predictor of the total score for leader empowering behaviors and 4 of 5 subscale scores, and meaning was the 2nd strongest predictor. Autonomy was not a significant predictor. Psychological empowerment, particularly in the form of psychological competence, is an important leader characteristic and should be a focus of leadership development strategies.

The impact of stroke on world leaders.

PubMed

Brickfield, F X; Pyenson, L R

2001-03-01

Earlier studies by our unit documented frequent disability in world leaders resulting from stroke but did not quantify the incidence of cerebrovascular accidents. We sought to identify the frequency and impact of strokes in world leaders. Using various sources, we identified world leaders who had sustained strokes while in office from 1970 to 1999 and tabulated information on symptoms and subsequent ability to lead. Twenty leaders were identified who had sustained strokes during the study period, for an incidence of 0.444 strokes/100 leaders/year. Half of the affected leaders lost their political power within the year; most had persistent disabilities, which included motor, speech, cognitive, and emotional deficits. Strokes in world leaders may be slightly less common than expected based on studies of Western populations of similar age, but they are often devastating to a political career. Nonetheless, loss of political power is not inevitable.

Turn Obstacles into Opportunities: Team Leaders Use a Skillful Approach to Move Past Barriers to Learning

ERIC Educational Resources Information Center

MacDonald, Elisa B.

2013-01-01

This article describes the role of the skillful leader and what practical solutions are needed to overcome hurdles. What distinguishes the skillful team leader from a less-effective leader is his or her approach to overcoming hurdles, and are rooted in the leader's values, mindset, intelligence, and skill. When faced with hurdles to team…

Aspiring and Residing IT Leaders: A Legacy for the Future

ERIC Educational Resources Information Center

McIntosh, Keith W.

2012-01-01

Many people think there is a quick road to leadership success. Those who want to become IT leaders--that is, "aspiring leaders"--often think: "If I just do my job well, I will rise to a leadership position." Those who are already IT leaders--that is, "residing leaders"--often think: "If I just do my job well, I will leave a lasting legacy." Doing…

High-Speed Video Observations of a Natural Lightning Stepped Leader

NASA Astrophysics Data System (ADS)

Jordan, D. M.; Hill, J. D.; Uman, M. A.; Yoshida, S.; Kawasaki, Z.

2010-12-01

High-speed video images of one branch of a natural negative lightning stepped leader were obtained at a frame rate of 300 kfps (3.33 us exposure) on June 18th, 2010 at the International Center for Lightning Research and Testing (ICLRT) located on the Camp Blanding Army National Guard Base in north-central Florida. The images were acquired using a 20 mm Nikon lens mounted on a Photron SA1.1 high-speed camera. A total of 225 frames (about 0.75 ms) of the downward stepped leader were captured, followed by 45 frames of the leader channel re-illumination by the return stroke and subsequent decay following the ground attachment of the primary leader channel. Luminous characteristics of dart-stepped leader propagation in triggered lightning obtained by Biagi et al. [2009, 2010] and of long laboratory spark formation [e.g., Bazelyan and Raizer, 1998; Gallimberti et al., 2002] are evident in the frames of the natural lightning stepped leader. Space stems/leaders are imaged in twelve different frames at various distances in front of the descending leader tip, which branches into two distinct components 125 frames after the channel enters the field of view. In each case, the space stem/leader appears to connect to the leader tip above in the subsequent frame, forming a new step. Each connection is associated with significant isolated brightening of the channel at the connection point followed by typically three or four frames of upward propagating re-illumination of the existing leader channel. In total, at least 80 individual steps were imaged.

Discovering your authentic leadership.

PubMed

George, Bill; Sims, Peter; McLean, Andrew N; Mayer, Diana

2007-02-01

The ongoing problems in business leadership over the past five years have underscored the need for a new kind of leader in the twenty-first century: the authentic leader. Author Bill George, a Harvard Business School professor and the former chairman and CEO of Medtronic, and his colleagues, conducted the largest leadership development study ever undertaken. They interviewed 125 business leaders from different racial, religious, national, and socioeconomic backgrounds to understand how leaders become and remain authentic. Their interviews showed that you do not have to be born with any particular characteristics or traits to lead. You also do not have to be at the top of your organization. Anyone can learn to be an authentic leader. The journey begins with leaders understanding their life stories. Authentic leaders frame their stories in ways that allow them to see themselves not as passive observers but as individuals who learn from their experiences. These leaders make time to examine their experiences and to reflect on them, and in doing so they grow as individuals and as leaders. Authentic leaders also work hard at developing self-awareness through persistent and often courageous self-exploration. Denial can be the greatest hurdle that leaders face in becoming self-aware, but authentic leaders ask for, and listen to, honest feedback. They also use formal and informal support networks to help them stay grounded and lead integrated lives. The authors argue that achieving business results over a sustained period of time is the ultimate mark of authentic leadership. It may be possible to drive short-term outcomes without being authentic, but authentic leadership is the only way to create long-term results.

Are leader stereotypes masculine? A meta-analysis of three research paradigms.

PubMed

Koenig, Anne M; Eagly, Alice H; Mitchell, Abigail A; Ristikari, Tiina

2011-07-01

This meta-analysis examined the extent to which stereotypes of leaders are culturally masculine. The primary studies fit into 1 of 3 paradigms: (a) In Schein's (1973) think manager-think male paradigm, 40 studies with 51 effect sizes compared the similarity of male and leader stereotypes and the similarity of female and leader stereotypes; (b) in Powell and Butterfield's (1979) agency-communion paradigm, 22 studies with 47 effect sizes compared stereotypes of leaders' agency and communion; and (c) in Shinar's (1975) masculinity-femininity paradigm, 7 studies with 101 effect sizes represented stereotypes of leadership-related occupations on a single masculinity-femininity dimension. Analyses implemented appropriate random and mixed effects models. All 3 paradigms demonstrated overall masculinity of leader stereotypes: (a) In the think manager-think male paradigm, intraclass correlation = .25 for the women-leaders similarity and intraclass correlation = .62 for the men-leaders similarity; (b) in the agency-communion paradigm, g = 1.55, indicating greater agency than communion; and (c) in the masculinity-femininity paradigm, g = 0.92, indicating greater masculinity than the androgynous scale midpoint. Subgroup and meta-regression analyses indicated that this masculine construal of leadership has decreased over time and was greater for male than female research participants. In addition, stereotypes portrayed leaders as less masculine in educational organizations than in other domains and in moderate- than in high-status leader roles. This article considers the relation of these findings to Eagly and Karau's (2002) role congruity theory, which proposed contextual influences on the incongruity between stereotypes of women and leaders. The implications for prejudice against women leaders are also considered.

Leader emergence through interpersonal neural synchronization.

PubMed

Jiang, Jing; Chen, Chuansheng; Dai, Bohan; Shi, Guang; Ding, Guosheng; Liu, Li; Lu, Chunming

2015-04-07

The neural mechanism of leader emergence is not well understood. This study investigated (i) whether interpersonal neural synchronization (INS) plays an important role in leader emergence, and (ii) whether INS and leader emergence are associated with the frequency or the quality of communications. Eleven three-member groups were asked to perform a leaderless group discussion (LGD) task, and their brain activities were recorded via functional near infrared spectroscopy (fNIRS)-based hyperscanning. Video recordings of the discussions were coded for leadership and communication. Results showed that the INS for the leader-follower (LF) pairs was higher than that for the follower-follower (FF) pairs in the left temporo-parietal junction (TPJ), an area important for social mentalizing. Although communication frequency was higher for the LF pairs than for the FF pairs, the frequency of leader-initiated and follower-initiated communication did not differ significantly. Moreover, INS for the LF pairs was significantly higher during leader-initiated communication than during follower-initiated communications. In addition, INS for the LF pairs during leader-initiated communication was significantly correlated with the leaders' communication skills and competence, but not their communication frequency. Finally, leadership could be successfully predicted based on INS as well as communication frequency early during the LGD (before half a minute into the task). In sum, this study found that leader emergence was characterized by high-level neural synchronization between the leader and followers and that the quality, rather than the frequency, of communications was associated with synchronization. These results suggest that leaders emerge because they are able to say the right things at the right time.

The role of justice in team member satisfaction with the leader and attachment to the team.

PubMed

Phillips, J M; Douthitt, E A; Hyland, M M

2001-04-01

This study examined the effects of team decision accuracy, team member decision influence, leader consideration behaviors, and justice perceptions on staff members' satisfaction with the leader and attachment to the team in hierarchical decision-making teams. The authors proposed that staff members' justice perceptions would mediate the relationship between (a) team decision accuracy, (b) the amount of influence a staff member has in the team leader's decision, and (c) the leader's consideration behaviors and staff attachment to the team and satisfaction with the leader. The results of an experiment involving 128 participants in a total of 64 teams, who made recommendations to a confederate acting as the team leader, generally support the proposed model.

Tainted visions: the effect of visionary leader behaviors and leader categorization tendencies on the financial performance of ethnically diverse teams.

PubMed

Greer, Lindred L; Homan, Astrid C; De Hoogh, Annebel H B; Den Hartog, Deanne N

2012-01-01

Despite the increasing prevalence of ethnic diversity, findings regarding its effects on team performance remain contradictory. We suggest that past inconsistencies can be reconciled by examining the joint impact of leader behavior and leader categorization tendencies in ethnically diverse teams. We propose that leaders who exhibit high levels of visionary leader behavior and also have the tendency to categorize their team members into in- and out-groups will facilitate a negative effect of ethnic diversity on team communication and financial performance, whereas leaders who exhibit visionary behaviors but do not tend to categorize will lead ethnically diverse teams to positive outcomes. We find support for these ideas in a study of 100 retail outlets.

Leaders and Leadership in Academe.

ERIC Educational Resources Information Center

Vroom, Victor H.

1983-01-01

Four contingency theories of leadership are explored and contrasted. Predictions of leader types and leader behaviors that would follow from each are counterposed. External functions of the leader and interactions with organizational members who are not subordinates are discussed. (Author/MLW)

Elementary Mathematics Leaders

ERIC Educational Resources Information Center

Fennell, Francis; Kobett, Beth McCord; Wray, Jonathan A.

2013-01-01

Elementary school mathematics leaders often come to the realization that their position, however titled and determined, although dedicated to addressing needs in math teaching and learning, also entails and directly involves leadership. Elementary school math specialists/instructional leaders (referenced here as elementary mathematics leaders, or…

48 CFR 17.402 - Limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Leader Company Contracting 17.402 Limitations. (a) Leader company contracting is to be used only when— (1) The leader company has the necessary production... the Government's requirements without the assistance of a leader company; (3) The assistance required...

Modeling Insurgency, Counter-Insurgency, and Coalition Strategies and Operations

DTIC Science & Technology

2012-01-01

these structures to analyze the components of leadership, promotion , recruitment, financial resources, operational techniques, network communications...processes into account: promotion of junior leaders (j), loss of senior leaders to internal factors (l), recruitment of senior leaders (o), rate that senior...is modeled in a similar manner as senior lead- ers, using: promotion of foot soldiers to junior leaders (β1f), the loss of junior leaders promoted to

Army Leader Development Strategy: Developing Brigade Level Leaders through Balance, Emphasis, and Approach

DTIC Science & Technology

2014-06-13

accompanying assumption is that over a decade of 5 combat operations has created gaps in leader development visible at all levels of leadership. The third...future potential will steer leaders toward positions based on their aptitude rather than their previous experience and performance. This would...provides no metrics for determining how well leader development is understood from a pedagogical perspective. Lastly, responses indicate that a

The good leader.

PubMed

Bottles, K

2001-01-01

What are the traits of successful leaders and can they be applied to those of us in health care? Leaders must deal with conflict to get a group of people to move in the same direction. Successful leaders learn to have difficult conversations that increase understanding and morale and creatively deal with the inevitable interpersonal conflicts present in every organization made up of people. Another useful trait for a leader during uncertain and chaotic times is the ability to see things as they really are, rather than as we wish or believe them to be. Successful leaders are also usually optimists who level with their co-workers.

Leader-Follower Output Synchronization of Linear Heterogeneous Systems With Active Leader Using Reinforcement Learning.

PubMed

Yang, Yongliang; Modares, Hamidreza; Wunsch, Donald C; Yin, Yixin

2018-06-01

This paper develops optimal control protocols for the distributed output synchronization problem of leader-follower multiagent systems with an active leader. Agents are assumed to be heterogeneous with different dynamics and dimensions. The desired trajectory is assumed to be preplanned and is generated by the leader. Other follower agents autonomously synchronize to the leader by interacting with each other using a communication network. The leader is assumed to be active in the sense that it has a nonzero control input so that it can act independently and update its control to keep the followers away from possible danger. A distributed observer is first designed to estimate the leader's state and generate the reference signal for each follower. Then, the output synchronization of leader-follower systems with an active leader is formulated as a distributed optimal tracking problem, and inhomogeneous algebraic Riccati equations (AREs) are derived to solve it. The resulting distributed optimal control protocols not only minimize the steady-state error but also optimize the transient response of the agents. An off-policy reinforcement learning algorithm is developed to solve the inhomogeneous AREs online in real time and without requiring any knowledge of the agents' dynamics. Finally, two simulation examples are conducted to illustrate the effectiveness of the proposed algorithm.

We will be champions: Leaders' confidence in 'us' inspires team members' team confidence and performance.

PubMed

Fransen, K; Steffens, N K; Haslam, S A; Vanbeselaere, N; Vande Broek, G; Boen, F

2016-12-01

The present research examines the impact of leaders' confidence in their team on the team confidence and performance of their teammates. In an experiment involving newly assembled soccer teams, we manipulated the team confidence expressed by the team leader (high vs neutral vs low) and assessed team members' responses and performance as they unfolded during a competition (i.e., in a first baseline session and a second test session). Our findings pointed to team confidence contagion such that when the leader had expressed high (rather than neutral or low) team confidence, team members perceived their team to be more efficacious and were more confident in the team's ability to win. Moreover, leaders' team confidence affected individual and team performance such that teams led by a highly confident leader performed better than those led by a less confident leader. Finally, the results supported a hypothesized mediational model in showing that the effect of leaders' confidence on team members' team confidence and performance was mediated by the leader's perceived identity leadership and members' team identification. In conclusion, the findings of this experiment suggest that leaders' team confidence can enhance members' team confidence and performance by fostering members' identification with the team. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Clinical nursing leaders', team members' and service managers' experiences of implementing evidence at a local level.

PubMed

Kitson, Alison; Silverston, Heidi; Wiechula, Rick; Zeitz, Kathryn; Marcoionni, Danni; Page, Tammy

2011-05-01

To describe the experiences of 14 clinical nursing leaders introducing a knowledge translation (KT) project into one metropolitan acute care hospital in South Australia. The study also explored team members' and service managers' experiences. KT strategies assume that local (nursing) clinical leaders have the capacity and capability to champion innovation combining positional leadership roles (ward leader) with a project lead role. There is limited evidence to support these assumptions. Semi-structured interviews of clinical nursing leaders and managers were undertaken at month 4 and 12 of the project. Data were also collected from the interdisciplinary team members (n = 28). Clinical nursing leaders identified risks and anxieties associated with taking on an additional leadership role, whereas managers acknowledged the multiple pressures on the system and the need for local level innovation. Team members generally reported positive experiences. With support, clinical nursing leaders can effectively embrace KT project leadership roles that complement their positional leadership roles. Clinical nursing leaders' experiences differed from nursing and medical managers' experiences.   Managers need to be more attuned to the personal risks local leaders experience, providing support for leaders to experiment and innovate. Managers need to integrate local priorities with broader system wide agendas. © 2011 The Authors. Journal compilation © 2011 Blackwell Publishing Ltd.

Leadership = Communication? The Relations of Leaders' Communication Styles with Leadership Styles, Knowledge Sharing and Leadership Outcomes.

PubMed

de Vries, Reinout E; Bakker-Pieper, Angelique; Oostenveld, Wyneke

2010-09-01

PURPOSE: The purpose of this study was to investigate the relations between leaders' communication styles and charismatic leadership, human-oriented leadership (leader's consideration), task-oriented leadership (leader's initiating structure), and leadership outcomes. METHODOLOGY: A survey was conducted among 279 employees of a governmental organization. The following six main communication styles were operationalized: verbal aggressiveness, expressiveness, preciseness, assuredness, supportiveness, and argumentativeness. Regression analyses were employed to test three main hypotheses. FINDINGS: In line with expectations, the study showed that charismatic and human-oriented leadership are mainly communicative, while task-oriented leadership is significantly less communicative. The communication styles were strongly and differentially related to knowledge sharing behaviors, perceived leader performance, satisfaction with the leader, and subordinate's team commitment. Multiple regression analyses showed that the leadership styles mediated the relations between the communication styles and leadership outcomes. However, leader's preciseness explained variance in perceived leader performance and satisfaction with the leader above and beyond the leadership style variables. IMPLICATIONS: This study offers potentially invaluable input for leadership training programs by showing the importance of leader's supportiveness, assuredness, and preciseness when communicating with subordinates. ORIGINALITY/VALUE: Although one of the core elements of leadership is interpersonal communication, this study is one of the first to use a comprehensive communication styles instrument in the study of leadership.

Wellness-Promoting Practices Through Girl Scouts: A Pragmatic Superiority Randomized Controlled Trial With Additional Dissemination.

PubMed

Cull, Brooke J; Dzewaltowski, David A; Guagliano, Justin M; Rosenkranz, Sara K; Knutson, Cassandra K; Rosenkranz, Richard R

2018-01-01

To evaluate the effectiveness of in-person versus online Girl Scout leader wellness training for implementation of wellness-promoting practices during troop meetings (phase I) and to assess training adoption and current practices across the council (phase II). Pragmatic superiority trial (phase 1) followed by serial cross-sectional study (phase II). Girl Scout troop meetings in Northeast Kansas. Eighteen troop leaders from 3 counties (phase 1); 113 troop leaders from 7 counties (phase II). Phase I: Troop leaders attended 2 wellness training sessions (first in groups, second individually), wherein leaders set wellness-promoting practice implementation goals, self-monitored progress, and received guidance and resources for implementation. Leaders received the intervention in person or online. Phase I: At baseline and postintervention, leaders completed a wellness-promoting practice implementation questionnaire assessing practices during troop meetings (max score = 11). Phase II: Leaders completed a survey about typical troop practices and interest in further training. Phase I: Generalized linear mixed modeling. Phase I: In-person training increased wellness-promoting practice implementation more than online training (in person = 2.1 ± 1.8; online = 0.2 ± 1.2; P = .022). Phase II: Fifty-six percent of leaders adopted the training. For 8 of 11 wellness categories, greater than 50% of leaders employed wellness-promoting practices. In-person training was superior to online training for improvements in wellness-promoting practices. Wellness training was adopted by the majority of leaders across the council.

Educational Leaders and Inclusive Education: Perceptions, Roles, and Responsibilities

ERIC Educational Resources Information Center

Romanuck Murphy, Cammy

2018-01-01

This three article dissertation explores educational leaders' perceptions, roles, and responsibilities associated with inclusive special education. Educational leaders include district leaders involved in the special education decision-making process, principals, and assistant principals. Article one provides a detailed literature review outlining…

Leaders who create change and those who manage it. How leaders limit success.

PubMed

Bruhn, John G

2004-01-01

There is no formula for either leading or managing change. Every organization and leader is unique. Leading change, however, is more art than science. Managing change is more science than art. Leading change is not simply a matter of a leader's style or personality; it is a leader's philosophy of how to generate and mobilize the total resources of an organization to enable it to be its best. Managing change, on the other hand, is focused on maintaining stability in an organization and containing the effects of unwanted and unexpected change. Leaders set the limits of success in their organizations by how they manage change. The different approaches of 2 leaders who have created change to correct problems in our health care delivery system are discussed.

Professional Development in a Reform Context: Understanding the Design and Enactment of Learning Experiences Created by Teacher Leaders for Science Educators

NASA Astrophysics Data System (ADS)

Shafer, Laura

Teacher in-service learning about education reforms like NGSS often begin with professional development (PD) as a foundational component (Supovitz & Turner, 2000). Teacher Leaders, who are early implementers of education reform, are positioned to play a contributing role to the design of PD. As early implementers of reforms, Teacher Leaders are responsible for interpreting the purposes of reform, enacting reforms with fidelity to meet those intended goals, and are positioned to share their expertise with others. However, Teacher Leader knowledge is rarely accessed as a resource for the design of professional development programs. This study is unique in that I analyze the knowledge Teacher Leaders, who are positioned as developers of PD, bring to the design of PD around science education reform. I use the extended interconnected model of professional growth (Clarke & Hollingsworth, 2002; Coenders & Terlouw, 2015) to analyze the knowledge pathways Teacher Leaders' access as PD developers. I found that Teacher Leaders accessed knowledge pathways that cycled through their personal domain, domain of practice and domain of consequence. Additionally the findings indicated when Teacher Leaders did not have access to these knowledge domains they were unwilling to continue with PD design. These findings point to how Teacher Leaders prioritize their classroom experience to ground PD design and use their perceptions of student learning outcomes as an indicator of the success of the reform. Because professional development (PD) is viewed as an important resource for influencing teachers' knowledge and beliefs around the implementation of education reform efforts (Garet, et al., 2001; Suppovitz & Turner, 2000), I offer that Teacher Leaders, who are early implementers of reform measures, can contribute to the professional development system. The second part of this dissertation documents the instantiation of the knowledge of Teacher Leaders, who are positioned as designers and facilitators of PD. I examine the extent to which Teacher Leader knowledge is instantiated into specific resources and tasks during PD specifically for the Next Generation Science Standards (NGSS). The findings indicate that Teacher Leaders' knowledge is instantiated in tasks that promote and facilitate alignment of Teacher Leader goals for NGSS science practices-based instruction, which are framed around student learning outcomes. I offer a number of ways in which these findings can help educators and PD developers to better structure activities that present an alternative vision for science education that also provides the needed resources to shape how classroom tasks are designed and managed in ways that attend to and build on the practical knowledge of Teacher Leaders. The third part of this dissertation addresses the role Teacher Leaders play in this reform context with respect to their contributions to the professional development system. Based on the analyses of the Teacher Leaders in this study, I claim Teacher Leaders are essential contributors to the professional development system that extends beyond their typical role of participant. I argue that Teacher Leaders bring special expertise to the role of designers and facilitators of PD programs, and to the role of ambassadors for professional learning communities in a reform context. Because Teacher Leaders have a broader influence on the professional development system as pictured here, the Teacher Leaders in this study represent an essential piece of the reform puzzle.

Cloning and characterisation of type 4 fimbrial genes from Actinobacillus pleuropneumoniae.

PubMed

Stevenson, Andrew; Macdonald, Julie; Roberts, Mark

2003-03-20

Actinobacillus pleuropneumoniae is the cause of porcine pleuropneumoniae. Little is known about the mechanisms by which A. pleuropneumoniae colonises the respiratory tract. Fimbriae are common mediators of bacterial adherence to mucosal epithelia and have been observed on the surface of A. pleuropneumoniae cells. Here we report the identification and characterisation of the type 4 fimbrial structural gene (apfA) from A. pleuropneumoniae. In addition a number of open reading frames were identified in A. pleuropneumoniae that have significant homology to type 4 fimbrial biogenesis genes from other species, including a putative leader specific peptidase (apfD). A. pleuropneumoniae apfA codes for a predicted polypeptide of approximately 16kDa, removal of the leader sequence at the predicted cleavage site would yield a 14.5kDa polypeptide. The first 30 residues of the mature polypeptide are well conserved with other members of the group A type 4 fimbriae family. The signal sequence of ApfA is 13 amino acids in length and, unusually, the residue that precedes the cleavage site is alanine rather than glycine which is found in most other type 4 fimbriae. The C-terminus of ApfA possesses cysteine residues that are conserved in type 4 fimbriae of many species. In other type 4 fimbriae the distal C-terminal cysteines form a disulphide bond that produces a loop, which is important for the function of fimbriae and also comprises a major antigenic determinant. A motif within the predicted loop in ApfA was found to be highly conserved in type 4 fimbriae of other HAP organisms (Haemophilus, Actinobacillus, Pasteurella). The A. pleuropneumoniae type 4 fimbrial biogenesis genes showed the strongest homology to putative type 4 fimbrial genes of Haemophilus ducreyi. A. pleuropneumoniae apfA gene was shown to be present and highly conserved in different serotypes of A. pleuropneumoniae. Recombinant ApfA was produced and used to raise anti-ApfA antisera.

The Nematode Eukaryotic Translation Initiation Factor 4E/G Complex Works with a trans-Spliced Leader Stem-Loop To Enable Efficient Translation of Trimethylguanosine-Capped RNAs ▿ †

PubMed Central

Wallace, Adam; Filbin, Megan E.; Veo, Bethany; McFarland, Craig; Stepinski, Janusz; Jankowska-Anyszka, Marzena; Darzynkiewicz, Edward; Davis, Richard E.

2010-01-01

Eukaryotic mRNA translation begins with recruitment of the 40S ribosome complex to the mRNA 5′ end through the eIF4F initiation complex binding to the 5′ m7G-mRNA cap. Spliced leader (SL) RNA trans splicing adds a trimethylguanosine (TMG) cap and a sequence, the SL, to the 5′ end of mRNAs. Efficient translation of TMG-capped mRNAs in nematodes requires the SL sequence. Here we define a core set of nucleotides and a stem-loop within the 22-nucleotide nematode SL that stimulate translation of mRNAs with a TMG cap. The structure and core nucleotides are conserved in other nematode SLs and correspond to regions of SL1 required for early Caenorhabditis elegans development. These SL elements do not facilitate translation of m7G-capped RNAs in nematodes or TMG-capped mRNAs in mammalian or plant translation systems. Similar stem-loop structures in phylogenetically diverse SLs are predicted. We show that the nematode eukaryotic translation initiation factor 4E/G (eIF4E/G) complex enables efficient translation of the TMG-SL RNAs in diverse in vitro translation systems. TMG-capped mRNA translation is determined by eIF4E/G interaction with the cap and the SL RNA, although the SL does not increase the affinity of eIF4E/G for capped RNA. These results suggest that the mRNA 5′ untranslated region (UTR) can play a positive and novel role in translation initiation through interaction with the eIF4E/G complex in nematodes and raise the issue of whether eIF4E/G-RNA interactions play a role in the translation of other eukaryotic mRNAs. PMID:20154140

The nematode eukaryotic translation initiation factor 4E/G complex works with a trans-spliced leader stem-loop to enable efficient translation of trimethylguanosine-capped RNAs.

PubMed

Wallace, Adam; Filbin, Megan E; Veo, Bethany; McFarland, Craig; Stepinski, Janusz; Jankowska-Anyszka, Marzena; Darzynkiewicz, Edward; Davis, Richard E

2010-04-01

Eukaryotic mRNA translation begins with recruitment of the 40S ribosome complex to the mRNA 5' end through the eIF4F initiation complex binding to the 5' m(7)G-mRNA cap. Spliced leader (SL) RNA trans splicing adds a trimethylguanosine (TMG) cap and a sequence, the SL, to the 5' end of mRNAs. Efficient translation of TMG-capped mRNAs in nematodes requires the SL sequence. Here we define a core set of nucleotides and a stem-loop within the 22-nucleotide nematode SL that stimulate translation of mRNAs with a TMG cap. The structure and core nucleotides are conserved in other nematode SLs and correspond to regions of SL1 required for early Caenorhabditis elegans development. These SL elements do not facilitate translation of m(7)G-capped RNAs in nematodes or TMG-capped mRNAs in mammalian or plant translation systems. Similar stem-loop structures in phylogenetically diverse SLs are predicted. We show that the nematode eukaryotic translation initiation factor 4E/G (eIF4E/G) complex enables efficient translation of the TMG-SL RNAs in diverse in vitro translation systems. TMG-capped mRNA translation is determined by eIF4E/G interaction with the cap and the SL RNA, although the SL does not increase the affinity of eIF4E/G for capped RNA. These results suggest that the mRNA 5' untranslated region (UTR) can play a positive and novel role in translation initiation through interaction with the eIF4E/G complex in nematodes and raise the issue of whether eIF4E/G-RNA interactions play a role in the translation of other eukaryotic mRNAs.

When followers become toxic.

PubMed

Offerman, Lynn R

2004-01-01

Leaders are vulnerable, too. That is, they can be led astray just as their followers can--actually, by their followers. This happens in a variety of ways. Sometimes, good leaders end up making poor decisions because well-meaning followers are united and persuasive about a course of action. This is a particular problem for leaders who attract and empower strong followers. These executives need to become more skeptical of the majority view and push followers to examine their opinions more closely. At other times, leaders get into trouble because they are surrounded by followers who fool them with flattery and isolate them from uncomfortable realities. Charismatic leaders, who are most susceptible to this problem, need to make an extra effort to unearth disagreement and to find followers who are not afraid to pose hard questions. Organizational mechanisms like 360-degree feedback and executive coaching can help these leaders get at the truth within their companies. Finally, unscrupulous and ambitious followers may end up encroaching on the authority of the leader to such an extent that the leader becomes little more than a figurehead who has responsibility but no power. There's not much leaders can do to completely guard against a determined corporate lago, but those who communicate and live by a positive set of values will find themselves better protected. And since followers tend to model themselves after their leaders, the straightforward leader is less likely to have manipulative followers. In this article, George Washington University professor Lynn Offermann explores each of these dynamics in depth, arguing that leaders need to stir debate, look for friends who can deliver bad news, and communicate and act on a solid set of values.

The double-edged sword of leader charisma: Understanding the curvilinear relationship between charismatic personality and leader effectiveness.

PubMed

Vergauwe, Jasmine; Wille, Bart; Hofmans, Joeri; Kaiser, Robert B; De Fruyt, Filip

2018-01-01

This study advanced knowledge on charisma by (a) introducing a new personality-based model to conceptualize and assess charisma and by (b) investigating curvilinear relationships between charismatic personality and leader effectiveness. Moreover, we delved deeper into this curvilinear association by (c) examining moderation by the leader's level of adjustment and by (d) testing a process model through which the effects of charismatic personality on effectiveness are explained with a consideration of specific leader behaviors. Study 1 validated HDS charisma (Hogan Development Survey) as a useful trait-based measure of charisma. In Study 2 a sample of leaders (N = 306) were assessed in the context of a 360-degree development center. In line with the too-much-of-a-good-thing effect, an inverted U-shaped relationship between charismatic personality and observer-rated leader effectiveness was found, indicating that moderate levels are better than low or high levels of charisma. Study 3 (N = 287) replicated this curvilinear relationship and further illustrated the moderating role of leader adjustment, in such a way that the inflection point after which the effects of charisma turn negative occurs at higher levels of charisma when adjustment is high. Nonlinear mediation modeling further confirmed that strategic and operational leader behaviors fully mediate the curvilinear relationship. Leaders low on charisma are less effective because they lack strategic behavior; highly charismatic leaders are less effective because they lack operational behavior. In sum, this work provides insight into the dispositional nature of charisma and uncovers the processes through which and conditions under which leader charisma translates into (in)effectiveness. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Complete genome sequences of avian paramyxovirus type 8 strains goose/Delaware/1053/76 and pintail/Wakuya/20/78

PubMed Central

Paldurai, Anandan; Subbiah, Madhuri; Kumar, Sachin; Collins, Peter L.; Samal, Siba K.

2009-01-01

Complete consensus genome sequences were determined for avian paramyxovirus type 8 (APMV-8) strains goose/Delaware/1053/76 (prototype strain) and pintail/Wakuya/20/78. The genome of each strain is 15,342 nucleotides (nt) long, which follows the “rule of six”. The genome consists of six genes in the order of 3′-N-P/V/W-M-F-HN-L-5′. The genes are flanked on either side by conserved transcription start and stop signals, and have intergenic regions ranging from 1 to 30 nt. The genome contains a 55 nt leader region at the 3′-end and a 171 nt trailer region at the 5′-end. Comparison of sequences of strains Delaware and Wakuya showed nucleotide identity of 96.8% at the genome level and amino acid identities of 99.3%, 96.5%, 98.6%, 99.4%, 98.6% and 99.1% for the predicted N, P, M, F, HN and L proteins, respectively. Both strains grew in embryonated chicken eggs and in primary chicken embryo kidney cells, and 293T cells. Both strains contained only a single basic residue at the cleavage activation site of the F protein and their efficiency of replication in vitro depended on and was augmented by, the presence of exogenous protease in most cell lines. Sequence alignment and phylogenic analysis of the predicted amino acid sequence of APMV-8 strain Delaware proteins with the cognate proteins of other available APMV serotypes showed that APMV-8 is more closely related to APMV-2 and -6 than to APMV-1, -3 and -4. PMID:19341613

Evidence that a sequence similar to TAR is important for induction of the JC virus late promoter by human immunodeficiency virus type 1 Tat.

PubMed Central

Chowdhury, M; Taylor, J P; Chang, C F; Rappaport, J; Khalili, K

1992-01-01

A specific RNA sequence located in the leader of all human immunodeficiency virus type 1 (HIV-1) mRNAs termed the transactivation response element, or TAR, is a primary target for induction of HIV-1 long terminal repeat activity by the HIV-1-derived trans-regulatory protein, Tat. Human neurotropic virus, JC virus (JCV), a causative agent of the degenerative demyelinating disease progressive multifocal leukoencephalopathy, contains sequences in the 5' end of the late RNA species with an extensive homology to HIV-1 TAR. In this study, we examined the possible role of the JCV-derived TAR-homologous sequence in Tat-mediated activation of the JCV late promoter (Tada et al., Proc. Natl. Acad. Sci. USA 87:3479-3483, 1990). Results from site-directed mutagenesis revealed that critical G residues required for the function of HIV-1 TAR that are conserved in the JCV TAR homolog play an important role in Tat activation of the JCV promoter. In addition, in vivo competition studies suggest that shared regulatory components mediate Tat activation of the JCV late and HIV-1 long terminal repeat promoters. Furthermore, we showed that the JCV-derived TAR sequence behaves in the same way as HIV-1 TAR in response to two distinct Tat mutants, one of which that has no ability to bind to HIV-1 TAR and another that lacks transcriptional activity on a responsive promoter. These results suggest that the TAR homolog of the JCV late promoter is responsive to HIV-1 Tat induction and thus may participate in the overall activation of the JCV late promoter mediated by this transactivation. Images PMID:1331525

Leader Responses to Collective Failure, and Maintenance of Group Integration, Task Motivation, Compliance, and Leader Endorsement

DTIC Science & Technology

1980-11-01

21 Table 2 - Analysis of Variance Summary Table: Leader Attributions . 21 Table 3 - Mean Leader Attributions to Four Factors under Success...been examined. Studies (Julian, Hollander, and Regula, 1969; !4ichener and Lawler, 1975) have indicated that leaders of groups which fail suffer signif ...the collective failure induction, one-way analyses of variance vere performed comparing the three performance evaluation conditions with the no

Scouts in Contact: Tactical Vignettes for Cavalry Leaders

DTIC Science & Technology

2016-12-01

comprehension of those core fundamentals that must be mastered by all scout leaders and cavalry officers. These core fundamentals are intended to... listening post (LP) as an inferior force and maneuver the platoon to destroy the outpost with multiple forms of contact. If the platoon leader chooses a...leader now has to react to the contact. ○○○○ Cavalry leadership dilemma: The platoon leader must assess that this observation post (OP)/ listening

Narcissistic Leaders and Their Victims: Followers Low on Self-Esteem and Low on Core Self-Evaluations Suffer Most

PubMed Central

Nevicka, Barbara; De Hoogh, Annebel H. B.; Den Hartog, Deanne N.; Belschak, Frank D.

2018-01-01

Narcissistic leaders are self-absorbed and hold beliefs of entitlement and superiority. Their aggressive tendencies in the face of criticism and inclinations to validate their self-worth by derogating others may lead others to perceive them as being abusive. Here, we test the relationship between leader narcissism and followers’ perceptions of abusive supervision. Drawing upon research related to the behavioral plasticity hypothesis, we propose that followers with low self-esteem will perceive narcissistic leaders as more abusive than those with high self-esteem. Followers low on self-esteem are more insecure, more in need of approval from their supervisor and are more likely to interpret the haughty, derogatory attitude of narcissistic leaders as abusive. Such followers also make for ‘easier targets’ and thus may actually suffer more abusive behavior from their narcissistic leaders. In a first multi-source study of 85 leaders and 128 followers, we found support for the moderating role of follower self-esteem in the relationship between leader narcissism and perceived abusive supervision: Narcissistic leaders were rated as more abusive by followers who were low on self-esteem, but not those higher on self-esteem. In a second multi-source field study among 177 leader-follower dyads, we tested a moderated mediation model and showed that this finding also holds for the broader concept of follower core self-evaluations as a moderator. Abusive supervision, in turn, was related to lower follower performance and followers experiencing more burnout symptoms. Thus, followers low on self-esteem or low on core self-evaluations seem to suffer most from narcissistic leaders as they perceive them to be abusive and, in turn, these followers show reduced performance and more burnout symptoms when working for such leaders. This research thus identifies an important moderator that might help reconcile previous inconsistent findings regarding perceptions of narcissistic leaders. PMID:29651266

Narcissistic Leaders and Their Victims: Followers Low on Self-Esteem and Low on Core Self-Evaluations Suffer Most.

PubMed

Nevicka, Barbara; De Hoogh, Annebel H B; Den Hartog, Deanne N; Belschak, Frank D

2018-01-01

Narcissistic leaders are self-absorbed and hold beliefs of entitlement and superiority. Their aggressive tendencies in the face of criticism and inclinations to validate their self-worth by derogating others may lead others to perceive them as being abusive. Here, we test the relationship between leader narcissism and followers' perceptions of abusive supervision. Drawing upon research related to the behavioral plasticity hypothesis, we propose that followers with low self-esteem will perceive narcissistic leaders as more abusive than those with high self-esteem. Followers low on self-esteem are more insecure, more in need of approval from their supervisor and are more likely to interpret the haughty, derogatory attitude of narcissistic leaders as abusive. Such followers also make for 'easier targets' and thus may actually suffer more abusive behavior from their narcissistic leaders. In a first multi-source study of 85 leaders and 128 followers, we found support for the moderating role of follower self-esteem in the relationship between leader narcissism and perceived abusive supervision: Narcissistic leaders were rated as more abusive by followers who were low on self-esteem, but not those higher on self-esteem. In a second multi-source field study among 177 leader-follower dyads, we tested a moderated mediation model and showed that this finding also holds for the broader concept of follower core self-evaluations as a moderator. Abusive supervision, in turn, was related to lower follower performance and followers experiencing more burnout symptoms. Thus, followers low on self-esteem or low on core self-evaluations seem to suffer most from narcissistic leaders as they perceive them to be abusive and, in turn, these followers show reduced performance and more burnout symptoms when working for such leaders. This research thus identifies an important moderator that might help reconcile previous inconsistent findings regarding perceptions of narcissistic leaders.

Encouraging Civility as a Community College Leader

ERIC Educational Resources Information Center

Elsner, Paul A., Ed.; Boggs, George R., Ed.

2006-01-01

The contributors relate examples of situations in which leaders encountered unexpected and sometimes unprecedented incivility in their role as community college leaders. The chapters present their experiences, observations, lessons, and recommendations for handling crises that may befall leaders in an academic setting. This book contains the…

Probing Leader Cells in Endothelial Collective Migration by Plasma Lithography Geometric Confinement

PubMed Central

Yang, Yongliang; Jamilpour, Nima; Yao, Baoyin; Dean, Zachary S.; Riahi, Reza; Wong, Pak Kin

2016-01-01

When blood vessels are injured, leader cells emerge in the endothelium to heal the wound and restore the vasculature integrity. The characteristics of leader cells during endothelial collective migration under diverse physiological conditions, however, are poorly understood. Here we investigate the regulation and function of endothelial leader cells by plasma lithography geometric confinement generated. Endothelial leader cells display an aggressive phenotype, connect to follower cells via peripheral actin cables and discontinuous adherens junctions, and lead migrating clusters near the leading edge. Time-lapse microscopy, immunostaining, and particle image velocimetry reveal that the density of leader cells and the speed of migrating clusters are tightly regulated in a wide range of geometric patterns. By challenging the cells with converging, diverging and competing patterns, we show that the density of leader cells correlates with the size and coherence of the migrating clusters. Collectively, our data provide evidence that leader cells control endothelial collective migration by regualting the migrating clusters. PMID:26936382

Notch1-Dll4 signaling and mechanical force regulate leader cell formation during collective cell migration

PubMed Central

Riahi, Reza; Sun, Jian; Wang, Shue; Long, Min; Zhang, Donna D.; Wong, Pak Kin

2015-01-01

At the onset of collective cell migration, a subset of cells within an initially homogenous population acquires a distinct “leader” phenotype with characteristic morphology and motility. However, the factors driving leader cell formation as well as the mechanisms regulating leader cell density during the migration process remain to be determined. Here, we use single cell gene expression analysis and computational modeling to show that leader cell identity is dynamically regulated by Dll4 signaling through both Notch1 and cellular stress in a migrating epithelium. Time-lapse microscopy reveals that Dll4 is induced in leader cells after the creation of the cell-free region and leader cells are regulated via Notch1-Dll4 lateral inhibition. Furthermore, mechanical stress inhibits Dll4 expression and leader cell formation in the monolayer. Collectively, our findings suggest that a reduction of mechanical force near the boundary promotes Notch1-Dll4 signaling to dynamically regulate the density of leader cells during collective cell migration. PMID:25766473

In the moral eye of the beholder: the interactive effects of leader and follower moral identity on perceptions of ethical leadership and LMX quality

PubMed Central

Giessner, Steffen R.; Van Quaquebeke, Niels; van Gils, Suzanne; van Knippenberg, Daan; Kollée, Janine A. J. M.

2015-01-01

Previous research indicated that leader moral identity (MI; i.e., leaders’ self-definition in terms of moral attributes) predicts to what extent followers perceive their leader as ethical (i.e., demonstrating and promoting ethical conduct in the organization). Leadership, however, is a relational process that involves leaders and followers. Building on this understanding, we hypothesized that follower and leader MI (a) interact in predicting whether followers will perceive their leaders as ethical and, as a result, (b) influence followers’ perceptions of leader–follower relationship quality. A dyadic field study (N = 101) shows that leader MI is a stronger predictor of followers’ perceptions of ethical leadership for followers who are high (vs. low) in MI. Perceptions of ethical leadership in turn predict how the quality of the relationship will be perceived. Hence, whether leader MI translates to perceptions of ethical leadership and of better relationship quality depends on the MI of followers. PMID:26300820

Probing Leader Cells in Endothelial Collective Migration by Plasma Lithography Geometric Confinement.

PubMed

Yang, Yongliang; Jamilpour, Nima; Yao, Baoyin; Dean, Zachary S; Riahi, Reza; Wong, Pak Kin

2016-03-03

When blood vessels are injured, leader cells emerge in the endothelium to heal the wound and restore the vasculature integrity. The characteristics of leader cells during endothelial collective migration under diverse physiological conditions, however, are poorly understood. Here we investigate the regulation and function of endothelial leader cells by plasma lithography geometric confinement generated. Endothelial leader cells display an aggressive phenotype, connect to follower cells via peripheral actin cables and discontinuous adherens junctions, and lead migrating clusters near the leading edge. Time-lapse microscopy, immunostaining, and particle image velocimetry reveal that the density of leader cells and the speed of migrating clusters are tightly regulated in a wide range of geometric patterns. By challenging the cells with converging, diverging and competing patterns, we show that the density of leader cells correlates with the size and coherence of the migrating clusters. Collectively, our data provide evidence that leader cells control endothelial collective migration by regualting the migrating clusters.

Transformational leadership practices of nurse leaders in professional nursing associations.

PubMed

Ross, Erin J; Fitzpatrick, Joyce J; Click, Elizabeth R; Krouse, Helene J; Clavelle, Joanne T

2014-04-01

This study describes the transformational leadership (TL) practices of nurse leaders in professional nursing associations (PNAs). Professional nursing associations are vehicles to provide educational opportunities for nurses as well as leadership opportunities for members. Little has been published about the leadership practices of PNA members. E-mail surveys of 448 nurse leaders in PNAs were conducted in 2013 using the Leadership Practices Inventory (LPI). The top 2 TL practices of these nurse leaders were enabling others to act and encouraging the heart. Respondents with more leadership training reported higher TL practices. This is the 1st study to describe TL practices of nurse leaders in PNAs. Results of this study show that nurse leaders of PNAs emulate practices of TL. Transformational leaders can mobilize and direct association members in reaching shared values, objectives, and outcomes. Understanding TL practices of nurse leaders in PNAs are important to the future of nursing in order to enable nurses to lead change and advance health through these organizations.

Remembering the Leaders of China.

PubMed

Fu, Mingchen; Xue, Yan; DeSoto, K Andrew; Yuan, Ti-Fei

2016-01-01

In two studies, we examined Chinese students' memory for the names of the leaders of China. In Study 1, subjects were cued with the names of periods from China's history. Subjects listed as many leaders as possible from each period and put them in the correct ordinal position when they could (see Roediger and DeSoto, 2014). Results showed that within each period, a primacy effect and sometimes a recency effect emerged. Moreover, the average recall probability for leaders within a specific period was a function of the ordinal position of the period. In Study 2, we asked another group of subjects to identify the sources through which they were able to recall each leader. We found that most subjects remembered leaders due to class and coursework. We also found a relation between a leader's recall probability and the amount of information available on that leader on the Internet. Our findings further imply that the serial position function captures the form of collective memory.

Workload of Team Leaders and Team Members During a Simulated Sepsis Scenario.

PubMed

Tofil, Nancy M; Lin, Yiqun; Zhong, John; Peterson, Dawn Taylor; White, Marjorie Lee; Grant, Vincent; Grant, David J; Gottesman, Ronald; Sudikoff, Stephanie N; Adler, Mark; Marohn, Kimberly; Davidson, Jennifer; Cheng, Adam

2017-09-01

Crisis resource management principles dictate appropriate distribution of mental and/or physical workload so as not to overwhelm any one team member. Workload during pediatric emergencies is not well studied. The National Aeronautics and Space Administration-Task Load Index is a multidimensional tool designed to assess workload validated in multiple settings. Low workload is defined as less than 40, moderate 40-60, and greater than 60 signify high workloads. Our hypothesis is that workload among both team leaders and team members is moderate to high during a simulated pediatric sepsis scenario and that team leaders would have a higher workload than team members. Multicenter observational study. Nine pediatric simulation centers (five United States, three Canada, and one United Kingdom). Team leaders and team members during a 12-minute pediatric sepsis scenario. National Aeronautics and Space Administration-Task Load Index. One hundred twenty-seven teams were recruited from nine sites. One hundred twenty-seven team leaders and 253 team members completed the National Aeronautics and Space Administration-Task Load Index. Team leader had significantly higher overall workload than team member (51 ± 11 vs 44 ± 13; p < 0.01). Team leader had higher workloads in all subcategories except in performance where the values were equal and in physical demand where team members were higher than team leaders (29 ± 22 vs 18 ± 16; p < 0.01). The highest category for each group was mental 73 ± 13 for team leader and 60 ± 20 for team member. For team leader, two categories, mental (73 ± 17) and effort (66 ± 16), were high workload, most domains for team member were moderate workload levels. Team leader and team member are under moderate workloads during a pediatric sepsis scenario with team leader under high workloads (> 60) in the mental demand and effort subscales. Team leader average significantly higher workloads. Consideration of decreasing team leader responsibilities may improve team workload distribution.

Leader neurons in leaky integrate and fire neural network simulations.

PubMed

Zbinden, Cyrille

2011-10-01

In this paper, we highlight the topological properties of leader neurons whose existence is an experimental fact. Several experimental studies show the existence of leader neurons in population bursts of activity in 2D living neural networks (Eytan and Marom, J Neurosci 26(33):8465-8476, 2006; Eckmann et al., New J Phys 10(015011), 2008). A leader neuron is defined as a neuron which fires at the beginning of a burst (respectively network spike) more often than we expect by chance considering its mean firing rate. This means that leader neurons have some burst triggering power beyond a chance-level statistical effect. In this study, we characterize these leader neuron properties. This naturally leads us to simulate neural 2D networks. To build our simulations, we choose the leaky integrate and fire (lIF) neuron model (Gerstner and Kistler 2002; Cessac, J Math Biol 56(3):311-345, 2008), which allows fast simulations (Izhikevich, IEEE Trans Neural Netw 15(5):1063-1070, 2004; Gerstner and Naud, Science 326:379-380, 2009). The dynamics of our lIF model has got stable leader neurons in the burst population that we simulate. These leader neurons are excitatory neurons and have a low membrane potential firing threshold. Except for these two first properties, the conditions required for a neuron to be a leader neuron are difficult to identify and seem to depend on several parameters involved in the simulations themselves. However, a detailed linear analysis shows a trend of the properties required for a neuron to be a leader neuron. Our main finding is: A leader neuron sends signals to many excitatory neurons as well as to few inhibitory neurons and a leader neuron receives only signals from few other excitatory neurons. Our linear analysis exhibits five essential properties of leader neurons each with different relative importance. This means that considering a given neural network with a fixed mean number of connections per neuron, our analysis gives us a way of predicting which neuron is a good leader neuron and which is not. Our prediction formula correctly assesses leadership for at least ninety percent of neurons.

Eukaryotic initiation factor 3 (eIF3) and 5’ mRNA leader sequences as agents of translational regulation in Arabidopsis. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

von Arnim, Albrecht G.

2015-02-04

Protein synthesis, or translation, consumes a sizable fraction of the cell’s energy budget, estimated at 5% and up to 50% in differentiated and growing cells, respectively. Plants also invest significant energy and biomass to construct and maintain the translation apparatus. Translation is regulated by a variety of external stimuli. Compared to transcriptional control, attributes of translational control include reduced sensitivity to stochastic fluctuation, a finer gauge of control, and more rapid responsiveness to environmental stimuli. Yet, our murky understanding of translational control allows few generalizations. Consequently, translational regulation is underutilized in the context of transgene regulation, although synthetic biologists aremore » now beginning to appropriate RNA-level gene regulation into their regulatory circuits. We also know little about how translational control contributes to the diversity of plant form and function. This project explored how an emerging regulatory mRNA sequence element, upstream open reading frames (uORFs), is integrated with the general translation initiation machinery to permit translational regulation on specific mRNAs.« less

The Origins of Specificity in the Microcin-Processing Protease TldD/E.

PubMed

Ghilarov, Dmitry; Serebryakova, Marina; Stevenson, Clare E M; Hearnshaw, Stephen J; Volkov, Dmitry S; Maxwell, Anthony; Lawson, David M; Severinov, Konstantin

2017-10-03

TldD and TldE proteins are involved in the biosynthesis of microcin B17 (MccB17), an Escherichia coli thiazole/oxazole-modified peptide toxin targeting DNA gyrase. Using a combination of biochemical and crystallographic methods we show that E. coli TldD and TldE interact to form a heterodimeric metalloprotease. TldD/E cleaves the N-terminal leader sequence from the modified MccB17 precursor peptide, to yield mature antibiotic, while it has no effect on the unmodified peptide. Both proteins are essential for the activity; however, only the TldD subunit forms a novel metal-containing active site within the hollow core of the heterodimer. Peptide substrates are bound in a sequence-independent manner through β sheet interactions with TldD and are likely cleaved via a thermolysin-type mechanism. We suggest that TldD/E acts as a "molecular pencil sharpener": unfolded polypeptides are fed through a narrow channel into the active site and processively truncated through the cleavage of short peptides from the N-terminal end. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Potential aquaculture probiont Lactococcus lactis TW34 produces nisin Z and inhibits the fish pathogen Lactococcus garvieae.

PubMed

Sequeiros, Cynthia; Garcés, Marisa E; Vallejo, Marisol; Marguet, Emilio R; Olivera, Nelda L

2015-04-01

Bacteriocin-producing Lactococcus lactis TW34 was isolated from marine fish. TW34 bacteriocin inhibited the growth of the fish pathogen Lactococcus garvieae at 5 AU/ml (minimum inhibitory concentration), whereas the minimum bactericidal concentration was 10 AU/ml. Addition of TW34 bacteriocin to L. garvieae cultures resulted in a decrease of six orders of magnitude of viable cells counts demonstrating a bactericidal mode of action. The direct detection of the bacteriocin activity by Tricine-SDS-PAGE showed an active peptide with a molecular mass ca. 4.5 kDa. The analysis by MALDI-TOF-MS detected a strong signal at m/z 2,351.2 that corresponded to the nisin leader peptide mass without the initiating methionine, whose sequence STKDFNLDLVSVSKKDSGASPR was confirmed by MS/MS. Sequence analysis of nisin structural gene confirmed that L. lactis TW34 was a nisin Z producer. This nisin Z-producing strain with probiotic properties might be considered as an alternative in the prevention of lactococcosis, a global disease in aquaculture systems.

cDNA cloning of an intracellular form of the human interleukin 1 receptor antagonist associated with epithelium.

PubMed Central

Haskill, S; Martin, G; Van Le, L; Morris, J; Peace, A; Bigler, C F; Jaffe, G J; Hammerberg, C; Sporn, S A; Fong, S

1991-01-01

A cDNA encoding a receptor antagonist of interleukin 1 (IL-1ra), secreted from human monocytes, has recently been isolated and sequenced [Eisenberg, S. P., Evans, R. J., Arend, W. P., Verderber, E., Brewer, M. T., Hannum, C. H. & Thompson, R. C. (1990) Nature (London) 343, 341-346]. We have identified another version of this IL-1ra, which is predominantly expressed in epithelial cells. This IL-1ra lacks a leader sequence and, thus, is probably intracellular. Both proteins are derived from the same gene through use of an alternative transcriptional start site and internal splice-acceptor site. Expression of intracellular IL-1ra cDNA in COS cells demonstrated that the intracellular product specifically inhibited exogenous interleukin 1-dependent responses. Keratinocytes were shown to contain significant amounts of nonsecreted IL-1ra protein. Constitutive expression of the intracellular IL-1ra may be an intracellular defensive mechanism in exposed epithelial cells and/or may serve to regulate autocrine interleukin 1-mediated pathways of differentiation. Images PMID:1827201

Unique pathway of expression of an opal suppressor phosphoserine tRNA.

PubMed Central

Lee, B J; de la Peña, P; Tobian, J A; Zasloff, M; Hatfield, D

1987-01-01

An opal suppressor phosphoserine tRNA gene is present in single copy in the genomes of higher vertebrates. We have shown that the product of this gene functions as a suppressor in an in vitro assay, and we have proposed that it may donate a modified amino acid directly to protein in response to specific UGA codons. In this report, we show through in vitro and in vivo studies that the human and Xenopus opal suppressor phosphoserine tRNAs are synthesized by a pathway that is, to the best of our knowledge, unlike that of any known eukaryotic tRNA. The primary transcript of this gene does not contain a 5'-leader sequence; and, therefore, transcription of this suppressor is initiated at the first nucleotide within the coding sequence. The 5'-terminal triphosphate, present on the primary transcript, remains intact through 3'-terminal maturation and through subsequent transport of the tRNA to the cytoplasm. The unique biosynthetic pathway of this opal suppressor may underlie its distinctive role in eukaryotic cells. Images PMID:3114749

P-class pentatricopeptide repeat proteins are required for efficient 5′ end formation of plant mitochondrial transcripts

PubMed Central

Binder, Stefan; Stoll, Katrin; Stoll, Birgit

2013-01-01

It is well recognized that flowering plants maintain a particularly broad spectrum of factors to support gene expression in mitochondria. Many of these factors are pentatricopeptide repeat (PPR) proteins that participate in virtually all processes dealing with RNA. One of these processes is the post-transcriptional generation of mature 5′ termini of RNA. Several PPR proteins are required for efficient 5′ maturation of mitochondrial mRNA and rRNA. These so-called RNA PROCESSING FACTORs (RPF) exclusively represent P-class PPR proteins, mainly composed of canonical PPR motifs without any extra domains. Applying the recent PPR-nucleotide recognition code, binding sites of RPF are predicted on the 5′ leader sequences. The sequence-specific interaction of an RPF with one or a few RNA substrates probably directly or indirectly recruits an as-yet-unidentified endonuclease to the processing site(s). The identification and characterization of RPF is a major step toward the understanding of the role of 5′ end maturation in flowering plant mitochondria. PMID:24184847

Enterocin F4-9, a Novel O-Linked Glycosylated Bacteriocin

PubMed Central

Maky, Mohamed Abdelfattah; Ishibashi, Naoki; Zendo, Takeshi; Perez, Rodney Honrada; Doud, Jehan Ragab; Karmi, Mohamed

2015-01-01

Enterococcus faecalis F4-9 isolated from Egyptian salted-fermented fish produces a novel bacteriocin, termed enterocin F4-9. Enterocin F4-9 was purified from the culture supernatant by three steps, and its molecular mass was determined to be 5,516.6 Da by mass spectrometry. Amino acid and DNA sequencing showed that the propeptide consists of 67 amino acid residues, with a leader peptide containing a double glycine cleavage site to produce a 47-amino-acid mature peptide. Enterocin F4-9 is modified by two molecules of N-acetylglucosamine β-O-linked to Ser37 and Thr46. The O-linked N-acetylglucosamine moieties are essential for the antimicrobial activity of enterocin F4-9. Further analysis of the enterocin F4-9 gene cluster identified enfC, which has high sequence similarity to a glycosyltransferase. The antimicrobial activity of enterocin F4-9 covered a limited range of bacteria, including, interestingly, a Gram-negative strain, Escherichia coli JM109. Enterocin F4-9 is sensitive to protease, active at a wide pH range, and moderately resistant to heat. PMID:25956765

The effects of perceived organisational support and span of control on the organisational commitment of novice leaders.

PubMed

Havaei, Farinaz; Dahinten, V Susan; MacPhee, Maura

2015-04-01

The purpose of this study was to examine the main and interaction effects of perceived organisational support, span of control and leadership rank on novice nurse leaders' organisational commitment. As nurse leaders' organisational commitment is eroded at times of healthcare restructuring, it is important to study factors associated with organisational commitment. Cross-sectional data from 69 novice nurse leaders, collected via mailed surveys at two time points, were analysed using hierarchical regression. The findings supported our hypotheses about the positive effect of perceived organisational support, the positive effect of leadership rank and the negative effect of span of control on novice nurse leaders' organisational commitment. In addition, perceived organisational support was shown to moderate the negative effect of span of control on novice nurse leaders' organisational commitment at time 2. Organisational strategies aimed at supporting nurse leaders, and attention to span of control, are required to enhance the organisational commitment of novice nurse leaders. Nurse leaders with a wide span of control, in particular those with little leadership experience, need to adopt leadership strategies that maximise their effectiveness, such as organising smaller work groups or teams within their wide span of control. © 2013 John Wiley & Sons Ltd.

Ineffective Leadership.

PubMed

Itri, Jason N; Lawson, Leslie M

2016-07-01

Radiology leaders can have a profound impact on the success and working environment of a radiology department, promoting core values and inspiring staff members to achieve the organization's mission. On the other hand, ineffective leaders can have a devastating effect on a radiology department by impairing communication among members, undermining staff commitment to the organization's success, and stifling the development of other staff members and leaders in the organization. One of the most important investments a radiology department can make is in identifying, cultivating, and promoting new leaders. The authors describe 13 habits and characteristics of new leaders that lead these individuals to address situations in both ineffective and counterproductive ways, impeding the performance of a radiology department and its capacity to play a meaningful role in shaping the future of radiology. New leaders must continually learn and improve their leadership skills if they are to avoid the destructive habits of ineffective leaders and successfully overcome the challenges facing radiology today. Senior leaders may also benefit from understanding the pitfalls that make leaders ineffective and should strive to continually improve their leadership skills given the critical role of leadership in the success of radiology departments. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Leader communication approaches and patient safety: An integrated model.

PubMed

Mattson, Malin; Hellgren, Johnny; Göransson, Sara

2015-06-01

Leader communication is known to influence a number of employee behaviors. When it comes to the relationship between leader communication and safety, the evidence is more scarce and ambiguous. The aim of the present study is to investigate whether and in what way leader communication relates to safety outcomes. The study examines two leader communication approaches: leader safety priority communication and feedback to subordinates. These approaches were assumed to affect safety outcomes via different employee behaviors. Questionnaire data, collected from 221 employees at two hospital wards, were analyzed using structural equation modeling. The two examined communication approaches were both positively related to safety outcomes, although leader safety priority communication was mediated by employee compliance and feedback communication by organizational citizenship behaviors. The findings suggest that leader communication plays a vital role in improving organizational and patient safety and that different communication approaches seem to positively affect different but equally essential employee safety behaviors. The results highlights the necessity for leaders to engage in one-way communication of safety values as well as in more relational feedback communication with their subordinates in order to enhance patient safety. Copyright © 2015 Elsevier Ltd. and National Safety Council. Published by Elsevier Ltd. All rights reserved.

Hypothesis on the Origin of Chaotic Pulse Train in Dart Leader

NASA Astrophysics Data System (ADS)

Pu, Y.; Qie, X.; Sun, Z.; Jiang, R.; Liu, M.; Zhang, H.

2017-12-01

The origin of chaotic pulse train (CPT) during the dart leader propagation remains debatable. Based on previous observations, the `chaotic' dart leader is featured by chaotic electric fields, large charge transfer and high energetic radiation. In some cases, the cause of CPT was attributed to the concurrent branches or upward connecting leader. In this presentation, after carefully examining the simultaneous optical, electrical and VHF location data of triggered lightning in SHATLE and some results in other literature, we found the close relationship between the upper luminous leader segment and CPT. It is hypothesized that the CPT originates from the luminous corona zone around the upper leader channel beyond the leader tip. The fast, sufficient supply of negative charge from the cloud can result in a net negative charge layer around the ionized channel surface. Then new diffuse discharge can make a corona zone outside the channel and radiates in a chaotic way. The cloud charge reservoir and the speed of charge transfer, which can be indicated by the speed of the leader, are determinative to the generation of CPT. Using VHF location technique, we also estimated the speed evolution of the leader and link it with electric field change.

Leader evaluation and team cohesiveness in the process of team development: A matter of gender?

PubMed Central

Sczesny, Sabine; Gumí, Tània; Guimerà, Roger; Sales-Pardo, Marta

2017-01-01

Leadership positions are still stereotyped as masculine, especially in male-dominated fields (e.g., engineering). So how do gender stereotypes affect the evaluation of leaders and team cohesiveness in the process of team development? In our study participants worked in 45 small teams (4–5 members). Each team was headed by either a female or male leader, so that 45 leaders (33% women) supervised 258 team members (39% women). Over a period of nine months, the teams developed specific engineering projects as part of their professional undergraduate training. We examined leaders’ self-evaluation, their evaluation by team members, and team cohesiveness at two points of time (month three and month nine, the final month of the collaboration). While we did not find any gender differences in leaders’ self-evaluation at the beginning, female leaders evaluated themselves more favorably than men at the end of the projects. Moreover, female leaders were evaluated more favorably than male leaders at the beginning of the project, but the evaluation by team members did not differ at the end of the projects. Finally, we found a tendency for female leaders to build more cohesive teams than male leaders. PMID:29059231

Conceptualizing clinical nurse leader practice: an interpretive synthesis.

PubMed

Bender, Miriam

2016-01-01

The Institute of Medicine's Future of Nursing report identifies the clinical nurse leader as an innovative new role for meeting higher health-care quality standards. However, specific clinical nurse leader practices influencing documented quality outcomes remain unclear. Lack of practice clarity limits the ability to articulate, implement and measure clinical nurse leader-specific practice and quality outcomes. Interpretive synthesis design and grounded theory analysis were used to develop a theoretical understanding of clinical nurse leader practice that can facilitate systematic and replicable implementation across health-care settings. The core phenomenon of clinical nurse leader practice is continuous clinical leadership, which involves four fundamental activities: facilitating effective ongoing communication; strengthening intra and interprofessional relationships; building and sustaining teams; and supporting staff engagement. Clinical nurse leaders continuously communicate and develop relationships within and across professions to promote and sustain information exchange, engagement, teamwork and effective care processes at the microsystem level. Clinical nurse leader-integrated care delivery systems highlight the benefits of nurse-led models of care for transforming health-care quality. Managers can use this study's findings to frame an implementation strategy that addresses theoretical domains of clinical nurse leader practice to help ensure practice success. © 2015 John Wiley & Sons Ltd.

Supervisory Options for Instructional Leaders in Education

ERIC Educational Resources Information Center

Fritz, Carrie; Miller, Greg

2003-01-01

The principal purpose of this article was to identify supervisory approaches available to instructional leaders in education. Selected supervisory approaches served as the basis for creating the Supervisory Options for Instructional Leaders (SOIL) Model. Instructional leaders in a variety of educational settings could use this model. The SOIL…

Where Have All the Leaders Gone?

ERIC Educational Resources Information Center

Gmelch, Walter H.

This paper examines personal challenges that academic leaders face, attributes that institutional leaders should possess to succeed in transforming the university, how institutions of higher education can build the capacity for preparing new leaders, and how universities can respond to the leadership crisis in this time of transformation. Personal…

Teacher Leader Model Standards: Implications for Preparation, Policy, and Practice

ERIC Educational Resources Information Center

Berg, Jill Harrison; Carver, Cynthia L.; Mangin, Melinda M.

2014-01-01

Teacher leadership is increasingly recognized as a resource for instructional improvement. Consequently, teacher leader initiatives have expanded rapidly despite limited knowledge about how to prepare and support teacher leaders. In this context, the "Teacher Leader Model Standards" represent an important development in the field. In…

Christian School Leaders and Spirituality

ERIC Educational Resources Information Center

Banke, Susan; Maldonado, Nancy; Lacey, Candace H.

2012-01-01

This phenomenological study examined the spiritual experiences of Christian school leaders who are the spiritual leaders of their schools. A purposeful, nominated sample of 12 Christian school leaders was selected. In-depth, open-ended interviews were conducted, audio taped, and then transcribed verbatim. Data analysis was based on Rudestam and…

Using Games for Training Dismounted Light Infantry Leaders: Emergent Questions and Lessons Learned

DTIC Science & Technology

2005-09-01

training game producers, developers, and leaders and instructors at the Infantry School who served as subject-matter experts (SMEs) during game ... development , formal V and informal discussions with instructors and leaders who participated in our evaluations, and observations of Infantry leaders as

Five Years on: Leadership Challenges of an Experienced CEO

ERIC Educational Resources Information Center

Sarros, James C.; Sarros, Anne M.

2011-01-01

Experienced leaders face challenges that demand different leadership approaches to those of inexperienced leaders. The purposes of this article are to: (1) explore the leadership initiatives prominent for experienced leaders compared with inexperienced leaders; (2) examine the relationship between transformational leadership and these initiatives;…

The role of leaders' working alliance in premarital education.

PubMed

Owen, Jesse J; Rhoades, Galena K; Stanley, Scott M; Markman, Howard J

2011-02-01

Premarital (and general relationship) education programs, as a prevention method, have been shown to have a positive effect on marital quality and can prevent divorce. However, it is unclear whether these positive effects are consistent across leaders who conduct premarital education programs. Examining the variability in relationship outcomes attributed to the leaders of premarital education programs, and the role of general therapeutic factors such as working alliance in explaining relationship outcomes, may help increase the effectiveness of these programs. Accordingly, this study examined 31 leaders who trained 118 couples (236 attendees) in a randomized clinical trial of the Prevention and Relationship Enhancement Program (PREP), a research-based and empirically supported premarital education program being compared with a treatment as usual track. The results demonstrated that couples' relationship outcomes from pre- to post-training varied on the basis of the leader who provided the premarital education training. Both training in PREP and aggregated leader working alliance quality (as rated by attendees) explained variability between leaders in change in attendees' observed negative and positive communication. Leaders' aggregated working alliance quality also explained change in relationship satisfaction. In addition, attendees' ratings of their leaders' working alliance predicted change in their relationship satisfaction and confidence, and attendees had higher positive communication when they reported better working alliance with their leader. PsycINFO Database Record (c) 2011 APA, all rights reserved.

Physician Leadership: A Central Strategy to Transforming Healthcare.

PubMed

Oostra, Randall D

2016-01-01

As the role of the physician leader becomes increasingly important in the transformation of healthcare, how hospitals, health systems, and other healthcare organizations define that role is undergoing radical change. Traditional physician leadership roles no longer are effective, and the independent medical staff approach is changing to a collaborative, team-oriented model. The dyad relationship between physician leaders and operational leaders is shifting from a rigid, siloed set of responsibilities to a model characterized by a distributed, situational framework of accountabilities, and the scope of influence of the physician leader and operational leader fluctuates depending on the situation and individuals involved. In addition, the focus of the physician leader is moving to one founded in servant leadership, with an increased emphasis on creating supportive models to enhance physicians' success and place them in the roles of leader and integrator of health.

An empowerment framework for nursing leadership development: supporting evidence.

PubMed

Macphee, Maura; Skelton-Green, Judith; Bouthillette, France; Suryaprakash, Nitya

2012-01-01

This article is a report on a descriptive study of nurse leaders' perspectives of the outcomes of a formal leadership programme. Effective nurse leaders are necessary to address complex issues associated with healthcare systems reforms. Little is known about the types of leadership development programmes that most effectively prepare nurse leaders for healthcare challenges. When nurse leaders use structural and psychological empowerment strategies, the results are safer work environments and better nurse outcomes. The leadership development programme associated with this study is based on a unifying theoretical empowerment framework to empower nurse leaders and enable them to empower others. Twenty seven front-line and mid-level nurse leaders with variable years of experience were interviewed for 1 year after participating in a formal leadership development programme. Data were gathered in 2008-2009 from four programme cohorts. Four researchers independently developed code categories and themes using qualitative content analysis. Evidence of leadership development programme empowerment included nurse leader reports of increased self-confidence with respect to carrying out their roles and responsibilities; positive changes in their leadership styles; and perceptions of staff recognition of positive stylistic changes. Regardless of years of experience, mid-level leaders had a broader appreciation of practice environment issues than front-line leaders. Time for reflection was valuable to all participants, and front-line leaders, in particular, appreciated the time to discuss nurse-specific issues with their colleagues. This study provides evidence that a theoretical empowerment framework and strategies can empower nurse leaders, potentially resulting in staff empowerment. © 2011 The Authors. Journal of Advanced Nursing © 2011 Blackwell Publishing Ltd.

The Humble Leader: Association of Discrepancies in Leader and Follower Ratings of Implementation Leadership with Organizational Climate in Mental Health

PubMed Central

Aarons, Gregory A.; Ehrhart, Mark G.; Torres, Elisa M.; Finn, Natalie K.; Beidas, Rinad

2017-01-01

Objectives Discrepancies between leaders' self-ratings and follower ratings of the leader are common but usually go unrecognized. Research on discrepancies is limited but there is evidence that discrepancies are associated with organizational context. This study examined the association of leader-follower discrepancies in Implementation Leadership Scale (ILS) ratings of mental health clinic leaders, and the association of those discrepancies with organizational climate for involvement and performance feedback. Both involvement and performance feedback may be important for evidence-based practice implementation in mental health. Methods A total of 593 supervisors (i.e., leaders, n=80) and clinical service providers (i.e., followers, n=513) completed surveys including ratings of implementation leadership and organizational climate. Polynomial regression and response surface analyses were conducted to examine the associations of discrepancies in leader-follower ILS ratings with organizational involvement climate and performance feedback climate, aspects of climate likely to support EBP implementation. Results Both involvement climate and performance feedback climate were highest where leaders rated themselves low on the ILS and their followers rated those leaders high on the ILS (i.e., “humble leaders”). Conclusions Teams with “humble leaders” showed more positive organizational climate for involvement and for performance feedback, contextual factors important during EBP implementation and sustainment. Discrepancy in leader and follower ratings of implementation leadership should be a consideration in understanding and improving leadership and organizational climate for mental health services and for evidence-based practice implementation and sustainment in mental health and other allied health settings. PMID:27691380

An Observational Study of Provider Perspectives on Alternative Payment Models.

PubMed

Harris, Drew; Puskarz, Katherine

2017-10-01

Over the past decade, reimbursement in the US health care system has undergone rapid transformation. The Affordable Care Act and the Medicare Access and CHIP Reauthorization Act are some of the many changes challenging traditional modes of practice and raising concerns about practitioners' ability to adapt. Recently, physician satisfaction was proposed as an addition to the Triple Aim in acknowledgment of how the physician's attitude can affect outcomes. To understand how physicians perceive alternative payment models (APMs) and how those perceptions may vary by their organizational role, non-leader physicians (N = 31), physician leaders (N = 67), and health system leaders (N = 49) were surveyed using a mixed-methods approach. Respondents to the electronic survey, who were identified from a Jefferson College of Population Health program participant database, rated their organizations' responses to APMs and provided commentary. Analysis of the Likert scale quantitative data indicates a significant difference in ratings between the 3 groups, particularly between health system leaders and non-leader physicians. The aggregated Attitudes Toward APMs Scale indicates that health system leaders were statistically significantly more likely to rate themselves and their organizations as better prepared for APMs compared to non-leader physicians and physician leaders. Qualitative analysis of comments indicates that non-leader physicians are more negative of APMs, often expressing frustration at added administrative burdens, barriers to implementation, and inconsistent or unclear measurement requirements. These findings indicate that the negative feelings non-leader physicians and physician leaders, in particular, expressed could contribute to physician burnout and decreased professional satisfaction, and impede the effective implementation of APMs.

Refining and validating a conceptual model of Clinical Nurse Leader integrated care delivery.

PubMed

Bender, Miriam; Williams, Marjory; Su, Wei; Hites, Lisle

2017-02-01

To empirically validate a conceptual model of Clinical Nurse Leader integrated care delivery. There is limited evidence of frontline care delivery models that consistently achieve quality patient outcomes. Clinical Nurse Leader integrated care delivery is a promising nursing model with a growing record of success. However, theoretical clarity is necessary to generate causal evidence of effectiveness. Sequential mixed methods. A preliminary Clinical Nurse Leader practice model was refined and survey items developed to correspond with model domains, using focus groups and a Delphi process with a multi-professional expert panel. The survey was administered in 2015 to clinicians and administrators involved in Clinical Nurse Leader initiatives. Confirmatory factor analysis and structural equation modelling were used to validate the measurement and model structure. Final sample n = 518. The model incorporates 13 components organized into five conceptual domains: 'Readiness for Clinical Nurse Leader integrated care delivery'; 'Structuring Clinical Nurse Leader integrated care delivery'; 'Clinical Nurse Leader Practice: Continuous Clinical Leadership'; 'Outcomes of Clinical Nurse Leader integrated care delivery'; and 'Value'. Sample data had good fit with specified model and two-level measurement structure. All hypothesized pathways were significant, with strong coefficients suggesting good fit between theorized and observed path relationships. The validated model articulates an explanatory pathway of Clinical Nurse Leader integrated care delivery, including Clinical Nurse Leader practices that result in improved care dynamics and patient outcomes. The validated model provides a basis for testing in practice to generate evidence that can be deployed across the healthcare spectrum. © 2016 John Wiley & Sons Ltd.

A Phenomenology of Outdoor Education Leader Experiences

ERIC Educational Resources Information Center

Field, Stephanie C.; Lauzon, Lara L.; Meldrum, John T.

2016-01-01

Limited qualitative research exists on the experiences of outdoor education leaders. The purpose of this phenomenological study was to explore the job-related experiences of outdoor education leaders within and outside the workplace. Five participants who had experience as outdoor education leaders completed in-depth, one-on-one interviews about…

Leadership for Social Justice: A Canadian Perspective

ERIC Educational Resources Information Center

Ottmann, Jacqueline

2009-01-01

Literature on leadership and change suggests that leaders help drive and sustain first- and second-order change and that they help to motivate people towards a vision based on common values; therefore, leaders do need to be prepared for significant responsibility. Leaders should ask, what "grand narrative" are today's leaders, this…

Leader Behavior of Head Nurses through the Perceptions of Self and Others.

DTIC Science & Technology

1984-01-01

studies ......... 17 III. Methodology .. ....... ...... ......................... 25 Population and sample ........ .*... ............ . 25 Procedures...60....*.* Implications for future rsearch ............. 62 Implications for nursing comaunity...*................. 63 *.......****.*** 75 Vi List...able to distinguish the personality traits of leaders from the personality traits of non -leaders. The traits of leaders, she contends, are communication

Healthcare Leaders' Intention to Serve as Organizational Teachers

ERIC Educational Resources Information Center

Aggarwal, Sushma Kumari

2014-01-01

Today's organizational leaders are expected to actively participate and facilitate learning. A highly engaged and knowledgeable workforce, inspired by leaders, may increase the quality of service, and aid in maintaining and attracting loyal employees and customers. These leaders are now being asked to serve as organizational teachers. However,…

Principled Principals? Values-Driven Leadership: Evidence from Ten Case Studies of 'Outstanding' School Leaders.

ERIC Educational Resources Information Center

Gold, Anne; Evans, Jennifer; Earley, Peter; Halpin, David; Collarbone, Patricia

2003-01-01

Case studies of English schools with "outstanding leaders" finds them avoiding doing "bastard leadership" by mediating government policy through their own values. Explores ways in which school leaders promote and encourage shared values. Discusses how these leaders enact values-driven leadership by, for example, developing…

What Do Effective District Leaders Do? Strategies for Evaluating District Leadership. Policy Snapshot

ERIC Educational Resources Information Center

Hornung, Katie; Yoder, Nick

2014-01-01

In the wake of the Common Core State Standards and teacher evaluation reform, school leaders increasingly look to district leaders for support, coaching, and leadership. District leaders--superintendents, assistant or area superintendents, specialists, principal supervisors, and school business administrators--can hold varying and multiple roles…

The Preparation of Inclusive Social Justice Education Leaders

ERIC Educational Resources Information Center

Celoria, Davide

2016-01-01

This article is intended to spark dialogue and debate related to the preparation of inclusive social justice education leaders in a time of colorblindness. Drawing attention to the reductionist construction of the professional standards for educational leaders when it comes to preparing educational leaders who are ready to address and eliminate…

Teaching Leaders to Lead Themselves: An Emerging Leader Exercise

ERIC Educational Resources Information Center

Chavez, Carolyn I.; Gomez, Claudia; Valenzuela, Marcus; Perera, Yasanthi B.

2017-01-01

This article describes an exercise that allows students to experience and understand the importance of perception in leader emergence. Based on implicit leadership theories, this exercise asks students to provide one another with anonymous feedback about what extent they exhibit various trait-based leader behaviors. This exercise, which can be…

School Leader Relationships: The Need for Explicit Training on Rapport, Trust, and Communication

ERIC Educational Resources Information Center

Lasater, Kara

2016-01-01

An important aspect of school leadership is relationship development, but developing meaningful relationships as a school leader is challenging. School leader relationships are challenged by diverse stakeholder groups, varied contexts, and difficult situations. The complex nature of school leader relationships necessitates explicit training for…

Teacher Leadership: District and School Leader Readiness Tool

ERIC Educational Resources Information Center

American Institutes for Research, 2017

2017-01-01

As interest in teacher leadership has grown, many leading organizations have developed tools and guidance to support schools, districts, and teacher leaders themselves. For instance, the National Network of State Teachers of the Year developed resources on teacher leader career pathways and advocacy approaches, as well as teacher leader standards.…

Leader Noticing of Facilitation in Videocases of Mathematics Professional Development

ERIC Educational Resources Information Center

Lesseig, Kristin; Elliott, Rebekah; Kazemi, Elham; Kelley-Petersen, Megan; Campbell, Matthew; Mumme, Judith; Carroll, Cathy

2017-01-01

In this article, we report on "Researching Mathematics Leader Learning" ("RMLL"), a project designed to support leaders in learning how to facilitate robust opportunities for teachers' mathematical learning. Our two-phase research design allowed us to construct a set of videocase seminars, enact the seminar design with leaders,…

Christian School Leaders and Spirituality: A Phenomenological Study

ERIC Educational Resources Information Center

Banke, Susan; Maldonado, Nancy; Lacey, Candace H.

2011-01-01

This phenomenological study examined the spiritual experiences of Christian school leaders who are the spiritual leaders of their schools. A purposeful, nominated sample of 12 Christian school leaders was selected. In-depth, open-ended interviews were conducted, audio taped, and then transcribed verbatim. Data analysis was based on Rudestam and…

Identifying Opinion Leaders to Promote Behavior Change

ERIC Educational Resources Information Center

Valente, Thomas W.; Pumpuang, Patchareeya

2007-01-01

This article reviews 10 techniques used to identify opinion leaders to promote behavior change. Opinion leaders can act as gatekeepers for interventions, help change social norms, and accelerate behavior change. Few studies document the manner in which opinion leaders are identified, recruited, and trained to promote health. The authors categorize…

Inspiring and Equipping Students to Be Ethical Leaders.

PubMed

Schwartz, Arthur J

2015-01-01

This chapter describes the behaviors of the ethical leader and explores the reasons why leaders do not always act ethically. The chapter also offers five recommendations to help educators integrate the practices of ethical leadership into their work with student leaders. © 2015 Wiley Periodicals, Inc., A Wiley Company.

School Leader Succession: A Description of Transitional Experiences

ERIC Educational Resources Information Center

Zimmerman, Judith A.

2007-01-01

This qualitative case study describes the transitional experiences (first 4 1/2 months) of four school leaders. The "life cycle" of leaders is often short, necessitating job changes with resulting transitions, when new leaders must simultaneously learn their positions and make changes to improve schools. Using previous leadership…

How Academic Leaders Conceptualize the Phenomenon of Faculty Performance Appraisal Practices

ERIC Educational Resources Information Center

Soo Kim, Tatum

2016-01-01

This dissertation addresses the phenomenon of how academic leaders conceptualize faculty performance practices. Qualitative research methods were used to explore the experiences of 11 academic leaders from 4-year higher education institutions in the metropolitan area of New York, NY. Each academic leader had direct responsibility for faculty…

Selection Practices of Group Leaders: A National Survey.

ERIC Educational Resources Information Center

Riva, Maria T.; Lippert, Laurel; Tackett, M. Jan

2000-01-01

Study surveys the selection practices of group leaders. Explores methods of selection, variables used to make selection decisions, and the types of selection errors that leaders have experienced. Results suggest that group leaders use clinical judgment to make selection decisions and endorse using some specific variables in selection. (Contains 22…

Creating tomorrow's leaders today: the Emerging Nurse Leaders Program of the Texas Nurses Association.

PubMed

Sportsman, Susan; Wieck, Lynn; Yoder-Wise, Patricia S; Light, Kathleen M; Jordan, Clair

2010-06-01

The Texas Nurses Association initiated an Emerging Nurse Leaders Program as an approach to engaging new nurses in the leadership of the professional association. This article explains the program's origin, the commitment of the Texas Nurses Association to this process, the implementation of the plan, and the discussions that launched a new way of connecting leaders across generations. Further, it is an approach that any professional organization can use to encourage the involvement of new leaders.

Branching Patterns and Stepped Leaders in an Electric-Circuit Model for Creeping Discharge

NASA Astrophysics Data System (ADS)

Hidetsugu Sakaguchi,; Sahim M. Kourkouss,

2010-06-01

We construct a two-dimensional electric circuit model for creeping discharge. Two types of discharge, surface corona and surface leader, are modeled by a two-step function of conductance. Branched patterns of surface leaders surrounded by the surface corona appear in numerical simulation. The fractal dimension of branched discharge patterns is calculated by changing voltage and capacitance. We find that surface leaders often grow stepwise in time, as is observed in lightning leaders of thunder.

Identifying opinion leaders to promote behavior change.

PubMed

Valente, Thomas W; Pumpuang, Patchareeya

2007-12-01

This article reviews 10 techniques used to identify opinion leaders to promote behavior change. Opinion leaders can act as gatekeepers for interventions, help change social norms, and accelerate behavior change. Few studies document the manner in which opinion leaders are identified, recruited, and trained to promote health. The authors categorize close to 200 studies that have studied or used opinion leaders to promote behavior change into 10 different methods. They present the advantages and disadvantages of the 10 opinion leader identification methods and provide sample instruments for each. Factors that might influence programs to select one or another method are then discussed, and the article closes with a discussion of combining and comparing methods.

Getting what you want: How fit between desired and received leader sensitivity influences emotion and counterproductive work behavior.

PubMed

Rupprecht, Elizabeth A; Kueny, Clair Reynolds; Shoss, Mindy K; Metzger, Andrew J

2016-10-01

We challenge the intuitive belief that greater leader sensitivity is always associated with desirable outcomes for employees and organizations. Specifically, we argue that followers' idiosyncratic desires for, and perceptions of, leader sensitivity behaviors play a key role in how followers react to their leader's sensitivity. Moreover, these resulting affective experiences are likely to have important consequences for organizations, specifically as they relate to employee counterproductive work behavior (CWB). Drawing from supplies-values (S-V) fit theory and the stressor-emotion model of CWB, the current study focuses on the affective and behavioral consequences of fit between subordinates' ideal leader sensitivity behavior preferences and subordinates' perceptions of their actual leader's sensitivity behaviors. Polynomial regression analyses reveal that congruence between ideal and actual leader sensitivity influences employee negative affect and, consequently, engagement in counterproductive work behavior. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Developing leaders' strategic thinking through global work experience: the moderating role of cultural distance.

PubMed

Dragoni, Lisa; Oh, In-Sue; Tesluk, Paul E; Moore, Ozias A; VanKatwyk, Paul; Hazucha, Joy

2014-09-01

To respond to the challenge of how organizations can develop leaders who can think strategically, we investigate the relation of leaders' global work experiences--that is, those experiences that require the role incumbent to transcend national boundaries--to their competency in strategic thinking. We further examine whether leaders' exposure to a country whose culture is quite distinct from the culture of their own country (i.e., one that is culturally distant) moderates these relationships. Our analyses of 231 upper level leaders reveals that the time they have spent in global work experiences positively relates to their strategic thinking competency, particularly for leaders who have had exposure to a more culturally distant country. We discuss these findings in light of the research on international work experiences and leader development. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Does Leaders' Health (and Work-Related Experiences) Affect their Evaluation of Followers' Stress?

PubMed

Giorgi, Gabriele; Mancuso, Serena; Fiz Perez, Francisco Javier; Montani, Francesco; Courcy, Francois; Arcangeli, Giulio

2015-09-01

Stressed workers suffer from severe health problems which appear to have increased. Poor leadership is especially considered a source of stress. Indeed, supervisors might perceive their subordinates to be similar to them as far as stress is concerned and this might more widespread in organizations than previously thought. The present research investigates the relationships between leaders' health, in terms of work-related stress, mental health, and workplace bullying and their evaluation of subordinates' stress. Five regression models were formulated to test our hypothesis. This is a cross-sectional study among 261 Italian leaders, using supervisor self-assessment and leaders' assessments of their subordinates. Leaders' health was related to their evaluation of staff stress. Job demand, lack of job control, and lack of support by colleagues and supervisors evaluated in their subordinates were particularly associated with the leaders' own health. Implications for developing healthy leaders are finally discussed.

'Many are called...': participation by minority leaders in an AIDS intervention in San Francisco.

PubMed

Morales, E S; Fullilove, M T

1992-01-01

Though the AIDS epidemic has posed a significant threat to minority people, especially African Americans and Latinos, minority community response to the epidemic has lagged significantly behind the organized efforts initiated by the European-American gay community. To test the efficacy of an educational intervention in increasing the involvement of minority leaders in AIDS-related efforts, we identified and recruited 166 African-American and Latino leaders to participate in a randomized controlled trial. This report describes the identification and recruitment of leaders to the study. Overall, participation was low. Rates of participation were not associated with race but were significantly associated with category of leadership--that is, whether the individual was a religious leader, an agency director, an elected official, or an informal leader, with religious leaders least likely and agency directors most likely to participate. We discuss the implications of these findings for improving epidemic response in minority communities.

Why Trust Matters: How Confidence in Leaders Transforms What Adolescents Gain From Youth Programs.

PubMed

Griffith, Aisha N; Larson, Reed W

2016-12-01

Youth's trust in program leaders is considered a key to the positive impact of youth programs. We sought to understand how trust influences youth's program experiences from their perspective. We interviewed 108 ethnically diverse youth (ages 12-19) participating in 13 arts, leadership, and technology programs. Analysis of these accounts suggested five ways in which youth's trust in leaders amplified program benefits. Trust increased youth's (1) confidence in leaders' guidance in program activities, (2) motivation in the program, (3) use of leaders for mentoring, (4) use of leaders as a model of a well-functioning relationship, and (5) experience of program cohesiveness. Across benefits, trust allowed youth to draw on leaders' expertise, opened them to new experiences, and helped increase youth's agency. © 2015 The Authors. Journal of Research on Adolescence © 2015 Society for Research on Adolescence.

Does Leaders' Health (and Work-Related Experiences) Affect their Evaluation of Followers' Stress?

PubMed Central

Giorgi, Gabriele; Mancuso, Serena; Fiz Perez, Francisco Javier; Montani, Francesco; Courcy, Francois; Arcangeli, Giulio

2015-01-01

Background Stressed workers suffer from severe health problems which appear to have increased. Poor leadership is especially considered a source of stress. Indeed, supervisors might perceive their subordinates to be similar to them as far as stress is concerned and this might more widespread in organizations than previously thought. Methods The present research investigates the relationships between leaders' health, in terms of work-related stress, mental health, and workplace bullying and their evaluation of subordinates' stress. Five regression models were formulated to test our hypothesis. This is a cross-sectional study among 261 Italian leaders, using supervisor self-assessment and leaders' assessments of their subordinates. Results Leaders' health was related to their evaluation of staff stress. Job demand, lack of job control, and lack of support by colleagues and supervisors evaluated in their subordinates were particularly associated with the leaders' own health. Conclusion Implications for developing healthy leaders are finally discussed. PMID:26929835

The external leadership of self-managing teams: intervening in the context of novel and disruptive events.

PubMed

Morgeson, Frederick P

2005-05-01

Relatively little empirical research has been conducted on external leaders of self-managing teams. The integration of functional leadership theory with research on team routines suggests that leaders can intervene in teams in several different ways, and the effectiveness of this intervention depends on the nature of the events the team encounters. External team leaders from 3 organizations first described a series of events (N=117), and leaders and team members then completed surveys to quantitatively describe the events. Results indicated that leader preparation and supportive coaching were positively related to team perceptions of leader effectiveness, with preparation becoming more strongly related to effectiveness as event novelty increased. More active leader intervention activities (active coaching and sense making) were negatively related to satisfaction with leadership yet were positively related to effectiveness as events became more disruptive.

Tour leaders with detailed knowledge of travel-related diseases play a key role in disease prevention.

PubMed

Hsu, Shu-Hua; Huang, Hsien-Liang; Lu, Chia-Wen; Cheng, Shao-Yi; Lee, Long-Teng; Chiu, Tai-Yuan; Huang, Kuo-Chin

2018-02-01

In Taiwan, group tours are a popular mode of international travel; hence, group tour leaders must ensure traveler safety and health. This study identified factors influencing tour leaders' willingness to recommend pretravel medical consultation and vaccination.A cross-sectional questionnaire survey was administered to tour leaders from January 2011 to December 2012. Multivariate logistic regression analyses were performed to estimate the odds ratios of having a positive attitude and willingness based on different knowledge scores of the tour leaders after adjustments for age, sex, education level, and seniority.Tour leaders with a more detailed knowledge of both travel-related infectious and noninfectious diseases demonstrated a higher willingness to receive vaccination. They believed that consultation at travel clinics before travel can improve travelers' health (P < .05).This study supports the importance and effectiveness on educating tour leaders' knowledge about travel-related diseases to improve health care for travelers.

Leadership is associated with lower levels of stress

PubMed Central

Sherman, Gary D.; Lee, Jooa J.; Cuddy, Amy J. C.; Renshon, Jonathan; Oveis, Christopher; Gross, James J.; Lerner, Jennifer S.

2012-01-01

As leaders ascend to more powerful positions in their groups, they face ever-increasing demands. As a result, there is a common perception that leaders have higher stress levels than nonleaders. However, if leaders also experience a heightened sense of control—a psychological factor known to have powerful stress-buffering effects—leadership should be associated with reduced stress levels. Using unique samples of real leaders, including military officers and government officials, we found that, compared with nonleaders, leaders had lower levels of the stress hormone cortisol and lower reports of anxiety (study 1). In study 2, leaders holding more powerful positions exhibited lower cortisol levels and less anxiety than leaders holding less powerful positions, a relationship explained significantly by their greater sense of control. Altogether, these findings reveal a clear relationship between leadership and stress, with leadership level being inversely related to stress. PMID:23012416

The servant leader: a higher calling for dental professionals.

PubMed

Certosimo, Fred

2009-09-01

The dental profession is guided by normative principles that provide guidance to our leaders and practicing dentists in addressing the needs of patients and the profession, yet there is room for incorporating new ideas that help dental professionals meet their professional obligations. The purpose of this essay is to discuss the concept of "servant leadership," especially in contrast with "self-serving leaders," and to suggest that servant leadership is consistent with the high ethical and professional ideals of the dental profession. The servant leader is the antithesis of the self-serving leader, who incessantly seeks more power and acquisition of material possessions. The servant leader's highest priority is the people (patients/students/customers) he or she serves. The concept of the servant-leader can take us away from self-serving, top-down leadership and encourage us to think harder about how to respect, value, and motivate people and ultimately provide better service to our patients.

A commitment to values. A system integrates core values with leadership development.

PubMed

Maxfield, M M

1991-01-01

The Values in Leadership program, a new leadership development program created by the Sisters of Charity Health Care Systems (SCHCS), is designed to empower effective leaders to live out personal values compatible with those of the organization. The program, designed for middle and senior managers, comprises seven educational modules- Living Our Values; Valuing Individual Differences; Leader as Servant; Leader as Visionary; Leader as Catalyst; Leader as Mentor; Formative Leadership; and Leader as Mentor; Motivational Coaching. Throughout the sessions, participants discuss the four roles of an effective leader-servant, visionary, catalyst, and mentor-which are grounded in SCHCS core values. Participants are also challenged to identify specific actions that can be integrated into their leadership styles. These actions, drawn from SCHCS leadership practices and core values, are reinforced when participants return to their jobs and write plans to incorporate these practices into their daily work.

Nurse leaders' perceptions of an approaching organizational change.

PubMed

Salmela, Susanne; Eriksson, Katie; Fagerström, Lisbeth

2013-05-01

The aim of the study was to achieve more profound understanding of nurse leaders' perceptions of an approaching organizational change. We used a three-dimensional hermeneutical method of interpretation to analyze text from 17 interviews. The results suggest that nurse leaders were positive toward and actively engaged in continual change to their units, even though they perceived themselves as mere spectators of the change process. The nurse leaders believed that change might benefit patients and patient care, yet their adaptation lacked deeper engagement. The approaching merger affected the nurse leaders' identities on a deeply personal level. They experienced uneasiness and anxiety with regard to being nurse leaders, the future of nursing care, and their mandate as patient advocates. Nurse leaders are in a critical position to influence the success of organizational change, but the organizations covered in this study were not incorporating their knowledge and experiences into the change.

Sampled-data consensus in switching networks of integrators based on edge events

NASA Astrophysics Data System (ADS)

Xiao, Feng; Meng, Xiangyu; Chen, Tongwen

2015-02-01

This paper investigates the event-driven sampled-data consensus in switching networks of multiple integrators and studies both the bidirectional interaction and leader-following passive reaction topologies in a unified framework. In these topologies, each information link is modelled by an edge of the information graph and assigned a sequence of edge events, which activate the mutual data sampling and controller updates of the two linked agents. Two kinds of edge-event-detecting rules are proposed for the general asynchronous data-sampling case and the synchronous periodic event-detecting case. They are implemented in a distributed fashion, and their effectiveness in reducing communication costs and solving consensus problems under a jointly connected topology condition is shown by both theoretical analysis and simulation examples.

Integrating design and communication in engineering education: a collaboration between Northwestern University and the Rehabilitation Institute of Chicago.

PubMed

Hirsch, Penny L; Yarnoff, Charles

2011-01-01

The required course for freshmen in Northwestern University's engineering school - a 2-quarter sequence called Engineering Design and Communication (EDC) - is noteworthy not only for its project-based focus on user-centered design, but also for its innovative integrated approach to teaching communication, teamwork, and ethics. Thanks to the collaboration between EDC faculty and staff at the Rehabilitation Institute of Chicago, EDC students, at the beginning of their education, experience the excitement of solving problems for real clients and users. At the same time, these authentic design projects offer an ideal setting for teaching students how to communicate effectively to different audiences and perform productively as team members and future leaders in engineering.

Empowered Intersectionality among Black Female K-12 Leaders: A Transcendental Phenomenological Study

ERIC Educational Resources Information Center

McNeal, Carla

2017-01-01

Black female school leaders remain underrepresented as educational leaders in the K-12 context as marginalizing factors persist in the field. The purpose of this transcendental phenomenological study was to explore the lived experiences of Black female school leaders through the lens of intersectionality. For this research study, intersectionality…

What Do Students Experience as Peer Leaders of Learning Teams?

ERIC Educational Resources Information Center

Johnson, Erik C.; Robbins, Brett A.; Loui, Michael C.

2015-01-01

In a course for engineering freshmen, peer leaders facilitated optional study sessions, which implemented peer-led team learning workshops. Some leaders were paid teaching assistants, but most were undergraduate volunteers. To understand the experiences of the peer leaders, we asked them to keep weekly reflective journals. By performing a basic…

From practice to education: perspectives from three nurse leaders.

PubMed

Danna, Denise; Schaubhut, Rose M; Jones, John R

2010-02-01

Three nurse leaders recount their experiences transitioning from a practice career to an academic career. These nurse leaders discuss their experiences with role transition and gaining new competencies, comparing and contrasting the competencies of nurse educators and nurse leaders. Specific examples are presented addressing collaborative efforts between practice and education. Copyright 2010, SLACK Incorporated.

Working with community leadership to promote wildfire preparedness

Treesearch

Erika A. Lang; Pamela Jakes

2006-01-01

This study provides insights into the role of local leaders in wildfire preparedness, specifically, how leaders motivate residents to work together. We found that community leaders become involved in wildfire preparedness for a number of reasons and bring important skills with them from past experiences. The majority of leaders were involved in multiple leadership...

Caterpillars, Clowns, and Curry: School Leaders and the Ingredients for Self-Efficacy.

ERIC Educational Resources Information Center

Losee, Suzanne

School leaders must develop skills and tools to create patterns of relationships that facilitate collegiality and shared decision making and promote reflective inquiry. The connection between the preparation of school leaders and the daily process of nurturing a learning community is important. School leaders must develop and enhance their own…

In Search of the Congruent Leader.

ERIC Educational Resources Information Center

Kussrow, Paul G.; Purland, John

A lack of congruency on the part of many leaders results in diminished effectiveness, if not outright failure. The soundness of a person in authority is an essential characteristic for potency as a leader. Irrespective of what system of ethical thought is proposed, effectiveness for leaders only comes from a stream of thought that demonstrates a…

Building the Capacity of School Leaders and Teachers to Implement Reform at All Levels

ERIC Educational Resources Information Center

Southern Regional Education Board (SREB), 2010

2010-01-01

Leaders of successful high schools, middle grades schools and technology centers are strengthening their skills and involving the entire school in plans to raise student achievement. The best school leaders establish an environment of continuous progress in which teachers and leaders work together to upgrade curriculum and instruction, examine…

Learn to Lead: Mapping Workplace Learning of School Leaders

ERIC Educational Resources Information Center

Hulsbos, Frank Arnoud; Evers, Arnoud Theodoor; Kessels, Joseph Willem Marie

2016-01-01

In recent years policy makers' interest in the professional development of school leaders has grown considerably. Although we know some aspect of formal educational programs for school leaders, little is known about school leaders' incidental and non-formal learning in the workplace. This study aims to grasp what workplace learning activities…

State Legislative Leaders: Keys to Effective Legislation for Children and Families. A Report.

ERIC Educational Resources Information Center

State Legislative Leaders Foundation, Centerville, MA.

In 1993, the State Legislative Leaders Foundation launched a research project, "State Legislative Leaders: Keys To Effective Legislation for Children and Families." This report documents the findings of the project involving 177 of the most influential Republican and Democratic state legislature leaders from all 50 states. For more than…

Influence of Leader Behaviors on Creativity: A Comparative Study between South Korea and the United States

ERIC Educational Resources Information Center

Hwang, Seog Joo

2013-01-01

This study investigates what are the relationships between different leader behaviors (i.e. supportive, participative, and controlling leader behaviors) and follower creativity, and whether the relationships differ between South Korea and the United States. Although creativity research suggests that supportive leader behaviors tend to enhance…

Does Sex of Dyad Members Really Matter? A Review of Leader-Member Exchange

ERIC Educational Resources Information Center

Goertzen, Brent J.; Fritz, Susan M.

2004-01-01

Leader-member exchange (LMX) generally refers to the leadership process centered on the interactions between leaders and direct reports. The basic premise of high quality leader-member exchange relationships holds that direct reports gain tremendous benefits through these partnerships. LMX is perhaps the most commonly researched theory of…

Teacher Leader Administrators: Part 3 of a Symposium on Teachers as Leaders

ERIC Educational Resources Information Center

Smulyan, Lisa; Green, Jarrod; Lunstead, Jennifer; Norris, Becki

2017-01-01

In this latest continuation of our multipart symposium on teacher leadership, we examine what happens when self-defined teacher leaders become school administrators. Do teacher leaders who become administrators maintain a teacher identity? Can they remain committed to their vision of teacher leadership when they take on the normative requirements…

Leader's Guide: Facilitating Inquiry in the Classroom.

ERIC Educational Resources Information Center

Newton, Fred E.

This is the leader's guide and training materials for conducting workshops on an instructional system which utilizes the process of inquiry. The guide is designed for leaders of these workshops and lists the leader's activities. It is organized according to the 18 major workshop experiences, referred to as subset. Each subset guide is organized…

Guidelines for Becoming a Teacher Leader in Rural Special Education

ERIC Educational Resources Information Center

Collins, Belva C.; Leahy, Maria Marsella; Ault, Melinda Jones

2017-01-01

Special education teachers have a unique set of skills and opportunities to become leaders in the field of education. Some rural special education teachers, however, may not see themselves as potential leaders or believe they have opportunities to be leaders. This article provides guidelines for rural special education teachers to consider in…

The Multiple Roles that Youth Development Program Leaders Adopt with Youth

ERIC Educational Resources Information Center

Walker, Kathrin C.

2011-01-01

The roles that program leaders establish in their relationships with youth structure how leaders are able to foster youth development. This article examines the complex roles program leaders create in youth programs and investigates how they balanced multiple roles to most effectively respond to the youth they serve. Analyses of qualitative data…

The Good Man Speaks: A Rhetorical Analysis of the Charismatic Organizational Leader.

ERIC Educational Resources Information Center

Sotirin, Patty

Followers attribute authority to charismatic leaders through their faith and belief in them and in their mission. Charismatic authority in organizations involves an interaction of leader, followers, and moral order; in the eyes of the followers, the leader personifies that order. Authority must come from below because the ultimate decision to…

A Comparison of Student Leader and Non Leader Attitudes Toward Legalizing Marihuana

ERIC Educational Resources Information Center

Bittner, John R.; Cash, William B.

1971-01-01

The data tends to imply that campus leaders have attitudes on the issue of marihuana legalization which conform to the norms of a major midwestern university sampling. Drug education programs might include student leaders with local credibility and who may possess attitudes very similar to their peers. (Author/BY)

6 Steps to Learning Leadership

ERIC Educational Resources Information Center

Toll, Cathy A.

2010-01-01

A generation of principals has heard the mantra that they should be instructional leaders, but rarely have they been encouraged to be learning leaders. While an instructional leader pays attention to the planning, implementation, and evaluation of instruction, a learning leader focuses on what is learned and how it is learned. These roles are not…

Finding Common Ground: Teacher Leaders and Principals Speak out about Teacher Leadership

ERIC Educational Resources Information Center

Weiner, Jennie Miles

2011-01-01

This study investigates how a small group of teacher leaders and their principals, participating in a teacher leadership program called the teacher connector (TC), understand teacher leadership and its impact on their practice. TCs' responsibilities were typical of teacher leaders; thus, their experiences can provide insights into teacher leaders'…

Leader to Leader: Enduring Insights on Leadership from the Drucker Foundation's Award-Winning Journal.

ERIC Educational Resources Information Center

Hesselbein, Frances, Ed.; Cohen, Paul M., Ed.

Amid unprecedented social, demographic, and economic changes, leaders must enhance performance and deliver desired results. The growing importance of managing the explosion in information requires attention to defining organizational missions and visions. The 37 chapters in this work are divided into 7 parts. Part 1, "On Leaders and…

An Assessment of Educational Leaders' Multicultural Competences in Ethiopian Public Universities

ERIC Educational Resources Information Center

Geleta, Abeya; Amsale, Frew

2016-01-01

Multicultural Competences of higher education leaders refer directly to the multicultural knowledge, attitudes and skills of the leaders which is the focus of the present study. The demographic changes and the subsequent diversity in Ethiopian HEIs strongly demands the HEIs to be multiculturally competent, their leaders should in turn have the…

The Great Outdoors: Comparing Leader Development Programs at the U.S. Naval Academy

ERIC Educational Resources Information Center

Huey, Wesley S.; Smith, David G.; Thomas, Joseph J.; Carlson, Charles R.

2014-01-01

This study compares outdoor adventure-based leader development programs with a traditional non-outdoor program to test predictions about differential effects on leader development outcomes. Participants were drawn from the population of U.S. Naval Academy midshipmen involved in experiential leader development programs as a component of their…

Leadership in Groups: Social Networks and Perceptions of Formal and Informal Leaders

DTIC Science & Technology

2006-03-01

LEADERSHIP IN GROUPS: SOCIAL NETWORKS AND PERCEPTIONS OF FORMAL AND INFORMAL LEADERS THESIS...01 LEADERSHIP IN GROUPS: SOCIAL NETWORKS AND PERCEPTIONS OF FORMAL AND INFORMAL LEADERS THESIS Presented to the Faculty...DISTRIBUTION UNLIMITED. AFIT/GSS/ENV/06M-01 LEADERSHIP IN GROUPS: SOCIAL NETWORKS AND PERCEPTIONS OF FORMAL AND INFORMAL LEADERS

Online Leader Training Course: Nebraska Equine Extension Leader Certification

ERIC Educational Resources Information Center

Cottle, Lena; D'Angelo, Nicole

2015-01-01

The Nebraska Equine Advancement Level Leader Certification Program is an online learning tool that clarifies principles of the Nebraska 4-H Equine Advancement Programs. Through an online Moodle course through eXtension.org, 4-H leaders and Extension educators are able to fulfill the certification requirement from any location before allowing youth…

Reconciling Leadership Paradigms: Authenticity as Practiced by American Indian School Leaders

ERIC Educational Resources Information Center

Henderson, David; Carjuzaa, Jioanna; Ruff, William G.

2015-01-01

This phenomenological study examined the complexity American Indian K-12 school leaders face on reservations in Montana, USA The study described how these leaders have to reconcile their Westernized educational leadership training with their traditional ways of knowing, living, and leading. Three major themes emerged that enabled these leaders to…

Ethical Practice: A Study of Chilean School Leaders

ERIC Educational Resources Information Center

Cuellar, Carolina; Giles, David L.

2012-01-01

Purpose: This article seeks to report on a research inquiry that explored the educational praxis of ethical school leaders in Chile. Behaving ethically is an imperative for school leaders. Being an ethical educational leader is something different. It is not only about behaving according to standards, but also rather involves an ethical way of…

Toward a Two-Track Model of Leadership Training: Suggestions from Self-Monitoring Theory.

ERIC Educational Resources Information Center

Anderson, Lynn R.

1990-01-01

Contends high self-monitoring leaders should benefit most from leadership training requiring leaders' behavior to change as a function of group contingencies (Track I training). Contends low self-monitoring should profit most from training that instructs leaders to alter organizational structures to produce an effective match between the leader's…

Foreign Internal Defense

DTIC Science & Technology

2010-07-12

leaders. (h) Former political leaders or retired government officials. (i) Tribal or family leaders. (j) Agricultural leaders, farmers ...logistics sustainability overlay depicts potable water supplies, farms, orchards , growing seasons, and other relevant items. In built-up areas, this...explosives, and population patterns such as seasonal employment. Examples of potential effects are periods of drought that force farmers to become

Leadership and Leader Developmental Self-Efficacy: Their Role in Enhancing Leader Development Efforts.

PubMed

Murphy, Susan Elaine; Johnson, Stefanie K

2016-01-01

This chapter describes the role of two types of self-efficacy-leader self-efficacy and leader developmental efficacy-for enhancing leadership development. Practical implications for designing and developing leadership programs that take into account these two types of self-efficacy are discussed. © 2016 Wiley Periodicals, Inc., A Wiley Company.

75 FR 74703 - Leader One Energy, LLC; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-01

... FEDERAL ENERGY REGULATORY COMMISSION [Docket Nos. CP11-33-000; PF10-15-000] Leader One Energy, LLC; Notice of Application November 23, 2010 Take notice that on November 15, 2010, Leader One Energy, LLC (Leader One), 4643 South Ulster Street, Suite 1100, Denver, Colorado 80237, filed in Docket No. CP11-33...

Psychological Type and Sex Differences among Church Leaders in the United Kingdom

ERIC Educational Resources Information Center

Craig, Charlotte L.; Francis, Leslie J.; Robbins, Mandy

2004-01-01

A sample of 135 female and 164 male church leaders of mixed denominations completed the Francis Psychological Type Scales. The female church leaders demonstrated clear preferences for extraversion over introversion, for sensing over intuition, for feeling over thinking, and for judging over perceiving. The male church leaders demonstrated clear…

Mediated Leader Effects: The Impact of Newspapers' Portrayal of Party Leadership on Electoral Support.

PubMed

Aaldering, Loes; van der Meer, Tom; Van der Brug, Wouter

2018-01-01

Conventional wisdom holds that party leaders matter in democratic elections. As very few voters have direct contact with party leaders, media are voters' primary source of information about these leaders and, thus, the likely origin of leader effects on party support. Our study focuses on these supposed electoral effects of the media coverage of party leaders. We examine the positive and negative effects of specific leadership images in Dutch newspapers on vote intentions. To this end, we combine an extensive automated content analysis of leadership images in the media with a panel data set, the Dutch 1Vandaag Opinion Panel (1VOP), consisting of more than fifty thousand unique respondents and 110 waves of interviews conducted between September 2006 and September 2012. The results confirm that media coverage of party leaders' character traits affects voters: Positive mediated leadership images increase support for the leader's party, while negative images decrease this support. However, this influence is not unconditional: During campaign periods, positive leadership images have a stronger effect, while negative images no longer have an impact on subsequent vote intentions.

The essential tension between leadership and power: when leaders sacrifice group goals for the sake of self-interest.

PubMed

Maner, Jon K; Mead, Nicole L

2010-09-01

Throughout human history, leaders have been responsible for helping groups attain important goals. Ideally, leaders use their power to steer groups toward desired outcomes. However, leaders can also use their power in the service of self-interest rather than effective leadership. Five experiments identified factors within both the person and the social context that determine whether leaders wield their power to promote group goals versus self-interest. In most cases, leaders behaved in a manner consistent with group goals. However, when their power was tenuous due to instability within the hierarchy, leaders high (but not low) in dominance motivation prioritized their own power over group goals: They withheld valuable information from the group, excluded a highly skilled group member, and prevented a proficient group member from having any influence over a group task. These self-interested actions were eliminated when the group was competing against a rival outgroup. Findings provide important insight into factors that influence the way leaders navigate the essential tension between leadership and power. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

The myth of the team captain as principal leader: extending the athlete leadership classification within sport teams.

PubMed

Fransen, Katrien; Vanbeselaere, Norbert; De Cuyper, Bert; Vande Broek, Gert; Boen, Filip

2014-01-01

Although coaches and players recognise the importance of leaders within the team, research on athlete leadership is sparse. The present study expands knowledge of athlete leadership by extending the current leadership classification and exploring the importance of the team captain as formal leader of the team. An online survey was completed by 4,451 participants (31% females and 69% males) within nine different team sports in Flanders (Belgium). Players (N = 3,193) and coaches (N = 1,258) participated on all different levels in their sports. Results revealed that the proposed additional role of motivational leader was perceived as clearly distinct from the already established roles (task, social and external leader). Furthermore, almost half of the participants (44%) did not perceive their captain as the principal leader on any of the four roles. These findings underline the fact that the leadership qualities attributed to the captain as the team's formal leader are overrated. It can be concluded that leadership is spread throughout the team; informal leaders rather than the captain take the lead, both on and off the field.

The hidden treasure in nursing leadership: informal leaders.

PubMed

Downey, Marty; Parslow, Susan; Smart, Marcia

2011-05-01

The goal of the present article was to generate awareness of characteristics of informal leaders in healthcare with the emphasis on nurses in acute care settings. There is limited research or literature regarding informal leaders in nursing and how they positively impact nursing management, the organization and, ultimately, patient care. Identification of nurses with leadership characteristics is important so that leadership development and mentoring can occur within the nursing profession. More than ever, nursing needs energetic, committed and dedicated leaders to meet the challenges of the healthcare climate and the nursing shortage. This requires nurse leaders to consider all avenues to ensure the ongoing profitability and viability of their healthcare facility. This paper discusses clinical nurses as informal leaders; characteristics of the informal nurse leader, the role they play, how they impact their unit and how they shape the organization.   Informal nurse leaders are an underutilized asset in health care. If identified early, these nurses can be developed and empowered to impact unit performance, efficiency and environmental culture in a positive manner. © 2011 The Authors. Journal compilation © 2011 Blackwell Publishing Ltd.

Assessing the professional development needs of experienced nurse executive leaders.

PubMed

Leach, Linda Searle; McFarland, Patricia

2014-01-01

The objective of this study was to identify the professional development topics that senior nurse leaders believe are important to their advancement and success. Senior/experienced nurse leaders at the executive level are able to influence the work environment of nurses and institutional and health policy. Their development needs are likely to reflect this and other contemporary healthcare issues and may be different from middle and frontline managers. A systematic way of assessing professional development needs for these nurse leaders is needed. A descriptive study using an online survey was distributed to a convenience sample of nurse leaders who were members of the Association of California Nurse Leaders (ACNL) or have participated in an ACNL program. Visionary leadership, leading complexity, and effective teams were the highest ranked leadership topics. Leading change, advancing health: The future of nursing, healthy work environments, and healthcare reform were also highly ranked topics. Executive-level nurse leaders are important to nurse retention, effective work environments, and leading change. Regular assessment and attention to the distinct professional development needs of executive-level nurse leaders are a valuable human capital investment.

Believing in "us": exploring leaders' capacity to enhance team confidence and performance by building a sense of shared social identity.

PubMed

Fransen, Katrien; Haslam, S Alexander; Steffens, Niklas K; Vanbeselaere, Norbert; De Cuyper, Bert; Boen, Filip

2015-03-01

The present study examined the impact of athlete leaders' perceived confidence on their teammates' confidence and performance. Male basketball players (N = 102) participated in groups of 4. To manipulate leaders' team confidence, the appointed athlete leader of each newly formed basketball team (a confederate) expressed either high or low team confidence. The results revealed an effect of team confidence contagion such that team members had greater team confidence when the leader expressed high (rather than low) confidence in the team's success. Second, the present study sought to explain the mechanisms through which this contagion occurs. In line with the social identity approach to leadership, structural equation modeling demonstrated that this effect was partially mediated by team members' increased team identification. Third, findings indicated that when leaders expressed high team confidence, team members' performance increased during the test, but when leaders expressed low confidence, team members' performance decreased. Athlete leaders thus have the capacity to shape team members' confidence--and hence their performance--in both positive and negative ways. In particular, by showing that they believe in "our team," leaders are able not only to make "us" a psychological reality, but also to transform "us" into an effective operational unit. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Strength training in community settings: impact of lay leaders on program access and sustainability for rural older adults.

PubMed

Washburn, Lisa T; Cornell, Carol E; Phillips, Martha; Felix, Holly; Traywick, LaVona

2014-09-01

The effect of volunteer lay leaders on availability and sustainability of strength-training programs for older adults has not been well explored. We describe implementation of the StrongWomen strength training program by the Arkansas Cooperative Extension Service, and report on the relationship between delivery approach (agent-led, lay-led, or combination of agent- and lay-led) and program access and sustainability. All state Extension agents (n = 66) were surveyed on program implementation, continuance, and use of lay leaders. Program records were used to identify the number of trained lay leaders. Regression models were used to examine the relationship between delivery approach and group availability. Counties using lay leaders had twice as many groups as counties using only agents. There was a significant, positive relationship between the number of lay leaders and the number of groups. Counties using lay leaders were 8.3 times more likely to have continuing groups compared with counties not using lay leaders. Program continuance was significantly and positively associated with lay leader use. Lay delivery expanded access to strength training programs and increased the likelihood that programs would continue. This approach can be used to increase access to and sustainability of strength training programs, particularly in resource-constrained areas.

Interactional leader-follower sensorimotor communication strategies during repetitive joint actions.

PubMed

Candidi, Matteo; Curioni, Arianna; Donnarumma, Francesco; Sacheli, Lucia Maria; Pezzulo, Giovanni

2015-09-06

Non-verbal communication is the basis of animal interactions. In dyadic leader-follower interactions, leaders master the ability to carve their motor behaviour in order to 'signal' their future actions and internal plans while these signals influence the behaviour of follower partners, who automatically tend to imitate the leader even in complementary interactions. Despite their usefulness, signalling and imitation have a biomechanical cost, and it is unclear how this cost-benefits trade-off is managed during repetitive dyadic interactions that present learnable regularities. We studied signalling and imitation dynamics (indexed by movement kinematics) in pairs of leaders and followers during a repetitive, rule-based, joint action. Trial-by-trial Bayesian model comparison was used to evaluate the relation between signalling, imitation and pair performance. The different models incorporate different hypotheses concerning the factors (past interactions versus online movements) influencing the leader's signalling (or follower's imitation) kinematics. This approach showed that (i) leaders' signalling strategy improves future couple performance, (ii) leaders used the history of past interactions to shape their signalling, (iii) followers' imitative behaviour is more strongly affected by the online movement of the leader. This study elucidates the ways online sensorimotor communication help individuals align their task representations and ultimately improves joint action performance. © 2015 The Author(s).

Science Teacher Leaders: Exploring Practices and Potential

NASA Astrophysics Data System (ADS)

Stinson, John Kevin

It has become standard practice for teachers to step into the role of "teacher leaders" and perform a variety of curriculum, instruction and assessment tasks for schools and school districts. The literature regarding these Ohio K-12 teacher leaders, who may perform these tasks in addition to or in lieu of regular teaching assignments, rarely includes a disciplinary focus. In this exploratory, descriptive study the results of a web-based survey containing both closed and open-ended items were used in an inquiry into teacher leaders working with the discipline of science. Data from Ohio teachers responding to the survey were used first to create a standard profile for science teacher leaders. Descriptive statistics and correlations were then performed on quantitative survey data to explore science teacher leader tasks and factors that influence task performance. Analysis of data included descriptions of sense of purpose for their role held by these science teacher leaders. Results indicate that science teacher leaders appear to embrace their role as advocates for science and have great potential for implementing science education reform as well as other science-related school initiatives. Aligning performance, administrative oversight, impact on student achievement and teacher training concerning tasks science teacher leaders are expected to perform would enhance this potential. However, science teacher leaders face challenges to realizing that potential due to ambiguity of their leadership role, the breadth of tasks they tend to perform and lack of alignment between task and outcomes.

Features of Upward Positive Leaders Initiated From Towers in Natural Cloud-to-Ground Lightning Based on Simultaneous High-Speed Videos, Measured Currents, and Electric Fields

NASA Astrophysics Data System (ADS)

Visacro, Silverio; Guimaraes, Miguel; Murta Vale, Maria Helena

2017-12-01

Original simultaneous records of currents, close electric field, and high-speed videos of natural negative cloud-to-ground lightning striking the tower of Morro do Cachimbo Station are used to reveal typical features of upward positive leaders before the attachment, including their initiation and mode of propagation. According to the results, upward positive leaders initiate some hundreds of microseconds prior to the return stroke, while a continuous uprising current of about 4 A and superimposed pulses of a few tens amperes flow along the tower. Upon leader initiation, the electric field measured 50 m away from the tower at ground level is about 60 kV/m. The corresponding average field roughly estimated 0.5 m above the tower top is higher than 0.55 MV/m. As in laboratory experiments, the common propagation mode of upward positive leaders is developing continuously, without steps, from their initiation. Unlike downward negative leaders, upward positive leaders typically do not branch off, though they can bifurcate under the effect of a downward negative leader's secondary branch approaching their lateral surface. The upward positive leader's estimated average two-dimensional propagation speed, in the range of 0.06 × 106 to 0.16 × 106 m/s, has the same order of magnitude as that of downward negative leaders. Apparently, the speed tends to increase just before attachment.

Distilling the Antecedents and Enabling Dynamics of Leader Moral Courage: A Framework to Guide Action.

PubMed

Hutchinson, Marie; Jackson, Debra; Daly, John; Usher, Kim

2015-05-01

Intelligent, robust and courageous nursing leadership is essential in all areas of nursing, including mental health. However, in the nursing leadership literature, the theoretical discourse regarding how leaders recognise the need for action and make the choice to act with moral purpose is currently limited. Little has been written about the cognitions, capabilities and contextual factors that enable leader courage. In particular, the interplay between leader values and actions that are characterised as good or moral remains underexplored in the nursing leadership literature. In this article, through a discursive literature synthesis we seek to distill a more detailed understanding of leader moral courage; specifically, what factors contribute to leaders' ability to act with moral courage, what factors impede such action, and what factors do leaders need to foster within themselves and others to enable action that is driven by moral courage. From the analysis, we distilled a multi-level framework that identifies a range of individual characteristics and capabilities, and enabling contextual factors that underpin leader moral courage. The framework suggests leader moral courage is more complex than often posited in theories of leadership, as it comprises elements that shape moral thought and conduct. Given the complexity and challenges of nursing work, the framework for moral action derived from our analysis provides insight and suggestions for strengthening individual and group capacity to assist nurse leaders and mental health nurses to act with integrity and courage.

Leadership Perspectives on Operationalizing the Learning Health Care System in an Integrated Delivery System.

PubMed

Psek, Wayne; Davis, F Daniel; Gerrity, Gloria; Stametz, Rebecca; Bailey-Davis, Lisa; Henninger, Debra; Sellers, Dorothy; Darer, Jonathan

2016-01-01

Healthcare leaders need operational strategies that support organizational learning for continued improvement and value generation. The learning health system (LHS) model may provide leaders with such strategies; however, little is known about leaders' perspectives on the value and application of system-wide operationalization of the LHS model. The objective of this project was to solicit and analyze senior health system leaders' perspectives on the LHS and learning activities in an integrated delivery system. A series of interviews were conducted with 41 system leaders from a broad range of clinical and administrative areas across an integrated delivery system. Leaders' responses were categorized into themes. Ten major themes emerged from our conversations with leaders. While leaders generally expressed support for the concept of the LHS and enhanced system-wide learning, their concerns and suggestions for operationalization where strongly aligned with their functional area and strategic goals. Our findings suggests that leaders tend to adopt a very pragmatic approach to learning. Leaders expressed a dichotomy between the operational imperative to execute operational objectives efficiently and the need for rigorous evaluation. Alignment of learning activities with system-wide strategic and operational priorities is important to gain leadership support and resources. Practical approaches to addressing opportunities and challenges identified in the themes are discussed. Continuous learning is an ongoing, multi-disciplinary function of a health care delivery system. Findings from this and other research may be used to inform and prioritize system-wide learning objectives and strategies which support reliable, high value care delivery.

On the mechanism of X-ray production by dart leaders of lightning flashes

NASA Astrophysics Data System (ADS)

Cooray, Vernon; Dwyer, Joseph; Rakov, V.; Rahman, Mahbubur

2010-07-01

Radiation with energies up to about 250 keV associated with the dart leader phase of rocket-triggered lightning were reported by Dwyer et al. (2004). The mechanism of X-ray generation by dart leaders, however, is unknown at present. Recently, Cooray et al. (2009a) developed physical concepts and mathematical techniques necessary to calculate the electric field associated with the tip of dart leaders. We have utilized the results of these calculations together with the energy dependent frictional force on electrons, as presented by Moss et al. (2006), to evaluate the maximum energy an electron will receive in accelerating in the dart-leader-tip electric field. The main assumptions made in performing the calculations are: (a) the dart leader channel is straight and vertical; (b) the path of the electrons are straight inside the channel; and (c) the decay of the channel temperature is uniform along the length of the dart leader. In the calculation, we have taken into account the fact that the electric field is changing both in space and time and that the gas in the defunct return stroke channel is at atmospheric pressure and at elevated temperature (i.e. reduced gas density). The results of the calculation show that for a given dart leader current there is a critical defunct-return-stroke-channel temperature above which the cold electron runaway becomes feasible. For a typical dart leader, this temperature is around 2500 K. This critical temperature decreases with increase in dart leader current. Since the temperature of the defunct return stroke channel may lie in the range of 2000-4000 K, the results show that the electric field at the tip of dart leaders is capable of accelerating electrons to MeV energy levels.

Vision-Based Leader Vehicle Trajectory Tracking for Multiple Agricultural Vehicles

PubMed Central

Zhang, Linhuan; Ahamed, Tofael; Zhang, Yan; Gao, Pengbo; Takigawa, Tomohiro

2016-01-01

The aim of this study was to design a navigation system composed of a human-controlled leader vehicle and a follower vehicle. The follower vehicle automatically tracks the leader vehicle. With such a system, a human driver can control two vehicles efficiently in agricultural operations. The tracking system was developed for the leader and the follower vehicle, and control of the follower was performed using a camera vision system. A stable and accurate monocular vision-based sensing system was designed, consisting of a camera and rectangular markers. Noise in the data acquisition was reduced by using the least-squares method. A feedback control algorithm was used to allow the follower vehicle to track the trajectory of the leader vehicle. A proportional–integral–derivative (PID) controller was introduced to maintain the required distance between the leader and the follower vehicle. Field experiments were conducted to evaluate the sensing and tracking performances of the leader-follower system while the leader vehicle was driven at an average speed of 0.3 m/s. In the case of linear trajectory tracking, the RMS errors were 6.5 cm, 8.9 cm and 16.4 cm for straight, turning and zigzag paths, respectively. Again, for parallel trajectory tracking, the root mean square (RMS) errors were found to be 7.1 cm, 14.6 cm and 14.0 cm for straight, turning and zigzag paths, respectively. The navigation performances indicated that the autonomous follower vehicle was able to follow the leader vehicle, and the tracking accuracy was found to be satisfactory. Therefore, the developed leader-follower system can be implemented for the harvesting of grains, using a combine as the leader and an unloader as the autonomous follower vehicle. PMID:27110793

Vision-Based Leader Vehicle Trajectory Tracking for Multiple Agricultural Vehicles.

PubMed

Zhang, Linhuan; Ahamed, Tofael; Zhang, Yan; Gao, Pengbo; Takigawa, Tomohiro

2016-04-22

The aim of this study was to design a navigation system composed of a human-controlled leader vehicle and a follower vehicle. The follower vehicle automatically tracks the leader vehicle. With such a system, a human driver can control two vehicles efficiently in agricultural operations. The tracking system was developed for the leader and the follower vehicle, and control of the follower was performed using a camera vision system. A stable and accurate monocular vision-based sensing system was designed, consisting of a camera and rectangular markers. Noise in the data acquisition was reduced by using the least-squares method. A feedback control algorithm was used to allow the follower vehicle to track the trajectory of the leader vehicle. A proportional-integral-derivative (PID) controller was introduced to maintain the required distance between the leader and the follower vehicle. Field experiments were conducted to evaluate the sensing and tracking performances of the leader-follower system while the leader vehicle was driven at an average speed of 0.3 m/s. In the case of linear trajectory tracking, the RMS errors were 6.5 cm, 8.9 cm and 16.4 cm for straight, turning and zigzag paths, respectively. Again, for parallel trajectory tracking, the root mean square (RMS) errors were found to be 7.1 cm, 14.6 cm and 14.0 cm for straight, turning and zigzag paths, respectively. The navigation performances indicated that the autonomous follower vehicle was able to follow the leader vehicle, and the tracking accuracy was found to be satisfactory. Therefore, the developed leader-follower system can be implemented for the harvesting of grains, using a combine as the leader and an unloader as the autonomous follower vehicle.

The evolution of leader–follower reciprocity: the theory of service-for-prestige

PubMed Central

Price, Michael E.; Van Vugt, Mark

2014-01-01

We describe the service-for-prestige theory of leadership, which proposes that voluntary leader–follower relations evolved in humans via a process of reciprocal exchange that generated adaptive benefits for both leaders and followers. We propose that although leader–follower relations first emerged in the human lineage to solve problems related to information sharing and social coordination, they ultimately evolved into exchange relationships whereby followers could compensate leaders for services which would otherwise have been prohibitively costly for leaders to provide. In this exchange, leaders incur costs to provide followers with public goods, and in return, followers incur costs to provide leaders with prestige (and associated fitness benefits). Because whole groups of followers tend to gain from leader-provided public goods, and because prestige is costly for followers to produce, the provisioning of prestige to leaders requires solutions to the “free rider” problem of disrespectful followers (who benefit from leader services without sharing the costs of producing prestige). Thus service-for-prestige makes the unique prediction that disrespectful followers of beneficial leaders will be targeted by other followers for punitive sentiment and/or social exclusion. Leader–follower relations should be more reciprocal and mutually beneficial when leaders and followers have more equal social bargaining power. However, as leaders gain more relative power, and their high status becomes less dependent on their willingness to pay the costs of benefitting followers, service-for-prestige predicts that leader–follower relations will become based more on leaders’ ability to dominate and exploit rather than benefit followers. We review evidential support for a set of predictions made by service-for-prestige, and discuss how service-for-prestige relates to social neuroscience research on leadership. PMID:24926244

Should they stay or should they go? Leader duration and financial performance in local health departments.

PubMed

Jadhav, Emmanuel D; Holsinger, James W; Mays, Glen; Fardo, David

2015-01-01

The delivery of programs by local health departments (LHDs) has shifted from "if we do not have the money we don't do it" to LHD directors should "identify and fund public health priorities." This shift has subsequently increased performance expectations of LHD leaders. In the for-profit sector the leaders' failure to perform has resulted in a shortening tenure trend. Tenure is a proxy for human capital accumulation. In LHDs, the nature of association, if any, between leader tenure and agency performance is unknown. Examine association between financial performance of LHDs with short-, average-, and long-tenured LHD leaders. Variation in leader characteristics and percent change in expenditure were examined using a longitudinal cohort design and positive deviance methodology. Bivariate analysis of LHD financial performance and leader characteristics was conducted, and a logistic regression model was developed to test association between leader tenure and LHDs that experienced a positive percentage expenditure change. From a total of 2523 LHDs, 1453 were examined. The cross-sectional surveys of US public health agencies conducted by the National Association of County and City Health Officials in 2008 and 2010 contain the leader and LHD variables. Approximately 44% of LHDs experienced a positive percentage expenditure change. Leader tenure, age, gender, and education status were significantly associated with a positive percentage expenditure change using a chi-square test of independence. From the logistic regression analysis tenure, educational status, employment status, area population, governance, classification, and jurisdiction were statistically significant. Local health departments with leaders whose tenure was less than 2 years were less likely than those with average tenure to experience a positive percentage expenditure change. The odds ratios for tenure suggest that tenure is positively associated up to a threshold level and then declines. Implying that LHD financial performance is sensitive to leader tenure.

Expression of a recombinant human sperm-agglutinating mini-antibody in tobacco (Nicotiana tabacum L.).

PubMed

Xu, Bingfang; Copolla, Michael; Herr, John C; Timko, Michael P

2007-01-01

The murine monoclonal antibody (mAB) S19 recognizes an N-linked carbohydrate antigen designated sperm agglutination antigen-1 (SAGA1) located on the membrane protein CD52. This antigen is added to the sperm surface during epididymal maturation. Binding of the S19 mAB to SAGA-1 causes the rapid agglutination of sperm and blocks pre-fertilization events. Previous studies indicated that the S19 mAB may be a potential specific spermicidal agent (termed a spermistatic) capable of replacing current spermicidal products that contain harsh detergents with harmful side effects. The nucleotide sequences encoding the heavy (H) and light (L) chains of the S19 antibody were cloned. A chimeric gene was constructed using the nucleotide sequences encoding the variable regions of both the H and L chains, and this gene (scFv1 9) was expressed in transgenic tobacco (Nicotiana tabacum L.) to produce a recombinant anti-sperm antibody (RASA). Highest levels of RASA expression were observed in BY-2 plant cell suspension cultures and regenerated N. tabacum cv. Xanthi plants transformant in which the RASA coding sequences were expressed under the control of the Cauliflower Mosaic Virus 35S promoter containing a double-enhancer sequence (2X CaMV 35S). Subsequent modifications of the transgene including the addition of a 5'-untranslated sequence from the tobacco etch virus (TEV leader sequence), N-terminal fusion of the coding region with an endoplasmic reticulum targeting signal of patatin (pat) and C-terminal fusion with the endoplasmic reticulum retention signal peptide KDEL showed further enhancement of RASA expression. The plant-expressed RASA formed intrachain disulfide bonds and was primarily soluble in the cytoplasmic fraction of the cells. Introduction of a poly-histidine (6xHIS) tag in the recombinant RASA protein allowed for rapid purification of the recombinant protein using Ni-NTA chromatography. Optimization of scale-up production and purification of this plant-derived recombinant protein should provide large quantities of an inexpensive spermistatic plantibody.

Evolutionary Acquisition and Loss of Saxitoxin Biosynthesis in Dinoflagellates: the Second “Core” Gene, sxtG

PubMed Central

Orr, Russell J. S.; Stüken, Anke; Murray, Shauna A.

2013-01-01

Saxitoxin and its derivatives are potent neurotoxins produced by several cyanobacteria and dinoflagellate species. SxtA is the initial enzyme in the biosynthesis of saxitoxin. The dinoflagellate full mRNA and partial genomic sequences have previously been characterized, and it appears that sxtA originated in dinoflagellates through a horizontal gene transfer from a bacterium. So far, little is known about the remaining genes involved in this pathway in dinoflagellates. Here we characterize sxtG, an amidinotransferase enzyme gene that putatively encodes the second step in saxitoxin biosynthesis. In this study, the entire sxtG transcripts from Alexandrium fundyense CCMP1719 and Alexandrium minutum CCMP113 were amplified and sequenced. The transcripts contained typical dinoflagellate spliced leader sequences and eukaryotic poly(A) tails. In addition, partial sxtG transcript fragments were amplified from four additional Alexandrium species and Gymnodinium catenatum. The phylogenetic inference of dinoflagellate sxtG, congruent with sxtA, revealed a bacterial origin. However, it is not known if sxtG was acquired independently of sxtA. Amplification and sequencing of the corresponding genomic sxtG region revealed noncanonical introns. These introns show a high interspecies and low intraspecies variance, suggesting multiple independent acquisitions and losses. Unlike sxtA, sxtG was also amplified from Alexandrium species not known to synthesize saxitoxin. However, amplification was not observed for 22 non-saxitoxin-producing dinoflagellate species other than those of the genus Alexandrium or G. catenatum. This result strengthens our hypothesis that saxitoxin synthesis has been secondarily lost in conjunction with sxtA for some descendant species. PMID:23335767

Evolutionary acquisition and loss of saxitoxin biosynthesis in dinoflagellates: the second "core" gene, sxtG.

PubMed

Orr, Russell J S; Stüken, Anke; Murray, Shauna A; Jakobsen, Kjetill S

2013-04-01

Saxitoxin and its derivatives are potent neurotoxins produced by several cyanobacteria and dinoflagellate species. SxtA is the initial enzyme in the biosynthesis of saxitoxin. The dinoflagellate full mRNA and partial genomic sequences have previously been characterized, and it appears that sxtA originated in dinoflagellates through a horizontal gene transfer from a bacterium. So far, little is known about the remaining genes involved in this pathway in dinoflagellates. Here we characterize sxtG, an amidinotransferase enzyme gene that putatively encodes the second step in saxitoxin biosynthesis. In this study, the entire sxtG transcripts from Alexandrium fundyense CCMP1719 and Alexandrium minutum CCMP113 were amplified and sequenced. The transcripts contained typical dinoflagellate spliced leader sequences and eukaryotic poly(A) tails. In addition, partial sxtG transcript fragments were amplified from four additional Alexandrium species and Gymnodinium catenatum. The phylogenetic inference of dinoflagellate sxtG, congruent with sxtA, revealed a bacterial origin. However, it is not known if sxtG was acquired independently of sxtA. Amplification and sequencing of the corresponding genomic sxtG region revealed noncanonical introns. These introns show a high interspecies and low intraspecies variance, suggesting multiple independent acquisitions and losses. Unlike sxtA, sxtG was also amplified from Alexandrium species not known to synthesize saxitoxin. However, amplification was not observed for 22 non-saxitoxin-producing dinoflagellate species other than those of the genus Alexandrium or G. catenatum. This result strengthens our hypothesis that saxitoxin synthesis has been secondarily lost in conjunction with sxtA for some descendant species.

Modeling leaderless transcription and atypical genes results in more accurate gene prediction in prokaryotes.

PubMed

Lomsadze, Alexandre; Gemayel, Karl; Tang, Shiyuyun; Borodovsky, Mark

2018-05-17

In a conventional view of the prokaryotic genome organization, promoters precede operons and ribosome binding sites (RBSs) with Shine-Dalgarno consensus precede genes. However, recent experimental research suggesting a more diverse view motivated us to develop an algorithm with improved gene-finding accuracy. We describe GeneMarkS-2, an ab initio algorithm that uses a model derived by self-training for finding species-specific (native) genes, along with an array of precomputed "heuristic" models designed to identify harder-to-detect genes (likely horizontally transferred). Importantly, we designed GeneMarkS-2 to identify several types of distinct sequence patterns (signals) involved in gene expression control, among them the patterns characteristic for leaderless transcription as well as noncanonical RBS patterns. To assess the accuracy of GeneMarkS-2, we used genes validated by COG (Clusters of Orthologous Groups) annotation, proteomics experiments, and N-terminal protein sequencing. We observed that GeneMarkS-2 performed better on average in all accuracy measures when compared with the current state-of-the-art gene prediction tools. Furthermore, the screening of ∼5000 representative prokaryotic genomes made by GeneMarkS-2 predicted frequent leaderless transcription in both archaea and bacteria. We also observed that the RBS sites in some species with leadered transcription did not necessarily exhibit the Shine-Dalgarno consensus. The modeling of different types of sequence motifs regulating gene expression prompted a division of prokaryotic genomes into five categories with distinct sequence patterns around the gene starts. © 2018 Lomsadze et al.; Published by Cold Spring Harbor Laboratory Press.

Ethical Decision-Making by Educational Leaders: Its Foundations, Culture and More Recent Perspectives

ERIC Educational Resources Information Center

Robbins, Steven; Trabichet, Luc

2009-01-01

The belief that educational leaders need to be ethical decision-makers is recent. Thomas and Bainbridge suggest that an educational leader needs to develop technical competency in ethical leadership. Yet few leaders in schools have been trained in conflict resolution of an ethical nature and little importance has been given to this within existing…

Adapting the Interpersonal Process Model of Intimacy to Enhance the Co-Leader Relationship during Training

ERIC Educational Resources Information Center

Huffman, David D.; Fernando, Delini M.

2012-01-01

Group work literature acknowledges that the group co-leader relationship influences the development of group members and the group as a whole. However, little direction has been offered for supervisors of group co-leaders to facilitate the development of the co-leader relationship. Reis and Shaver's (1988) interpersonal process model of intimacy…

School Counselor Research as Perceived by American School Counselor Association Leaders: Implications for the Profession.

ERIC Educational Resources Information Center

Deck, Mary D.; And Others

1990-01-01

Surveyed leaders (n=116) of the American School Counselor Association to elicit information related to professional credentials, research training, and research experience of school counselors and to assess the opinions of leaders in the field related to research issues. Results indicated leaders perceived school counselors had little interest in…

Transformation Based Education Leaders--The Wheels That Drive Successful Institutions for Sustainable Educational Excellence

ERIC Educational Resources Information Center

Leonard, Bobby

2006-01-01

In this article, author Bobby Leonard asserts that the best institutions in India today are good in Policies Systems and administration. However, the key is developing a new generation of education based workforce under the hands of a good leader. India requires transformational leaders, leaders who can transform educational systems and who are…

Preparing Principals to Raise Student Achievement: Implementation and Effects of the New Leaders Program in Ten Districts. Appendix

ERIC Educational Resources Information Center

Gates, Susan M.; Hamilton, Laura S.; Martorell, Paco; Burkhauser, Susan; Heaton, Paul; Pierson, Ashley; Baird, Matthew; Vuollo, Mirka; Li, Jennifer J.; Lavery, Diana Catherine; Harvey, Melody; Gu, Kun

2014-01-01

New Leaders is dedicated to promoting student achievement by developing outstanding school leaders to serve in urban schools. RAND Corporation researchers conducted a formative and summative external evaluation of the New Leaders program, its theory of action, and its implementation from 2006 through 2013. This document presents technical…

4-H Horticulture Project Activity Guides. Leader's Guide and Units 1-3.

ERIC Educational Resources Information Center

Illinois Univ., Urbana. Cooperative Extension Service.

This document, concerning the 4-H horticulture project, includes a leader's guide and three youth activity guides. The leader's guide can be used to plan group project meetings that are both fun and educational. Activities can be adapted to various age groups. The leader's guide includes basic information for growing plants indoors and outdoors,…

What School Leaders Need to Know about English Learners

ERIC Educational Resources Information Center

Dormer, Jan Edwards

2016-01-01

School leaders have the unique opportunity and responsibility to play a crucial role in creating a culture of high expectations and an environment of support so that ELLs can succeed and continue to enrich the fabric of our country. "What School Leaders Need to Know About English Learners" offers school leaders the foundation, the ideas,…

A Phenomenological Study of Mindfulness of Curriculum Directors in a Midwest State

ERIC Educational Resources Information Center

Carenza, Gregory S.

2012-01-01

Problem. Today's educational leaders face a growing barrage of challenges that threaten to detract from their ability to sustain resonant leadership over time. Leaders who ignore the signs and signals around them not only debilitate themselves as leaders but their organizations as well. These leaders simply are not getting enough, accurate, or…

The School Leader Communication Model: An Emerging Method for Bridging School Leader Preparation and Practice

ERIC Educational Resources Information Center

Dotger, Benjamin H.

2011-01-01

School leaders make countless decisions but do not receive adequate preparation for communicating their decisions to parents, students, and teachers. Building on the need to prepare school leaders for a variety of complex professional situations, this article introduces the medical education pedagogy of standardized patients to the field of school…

Exploring Knowledge Exchange between Senior and Future Leaders: A Grounded-Theory Study

ERIC Educational Resources Information Center

Gonzaga, Stephanie Young

2009-01-01

A grounded theory study examined senior leaders methods of knowledge sharing with junior leaders in a small commercial mortgage company. The study was designed to develop an emergent theory to explain the cultural elements that influenced the methods leaders used to transfer knowledge to junior people. The study identified a systemic value of…

Eta Sigma Gamma: Preparing Leaders Today for Tomorrow's Challenges

ERIC Educational Resources Information Center

Brown, Kelli McCormack

2007-01-01

There is no one definition for a leader or for leadership, but most people can identify a leader and can provide qualities of a good leader or good leadership. The founders of Eta Gamma Gamma--William Bock, Warren Schaller, and Robert Synovitz--all displayed a critical characteristic of leadership by having and acting on a vision. Leadership has…

The Importance of School Leaders' Engagement in Socialising Newly Qualified Teachers into the Teaching Profession

ERIC Educational Resources Information Center

Engvik, Gunnar; Emstad, Anne Berit

2017-01-01

This article focuses on the importance of school leaders' commitment to socialising newly qualified teachers (NQTs) into the teaching profession. Framed by a social constructivist perspective, the article is based on four challenges novice teachers face as described by four school leaders. The aim is to illuminate how school leaders have…

Commander’s Handbook for Unit Leader Development

DTIC Science & Technology

2007-07-02

Transforming Organizations: Growing Leaders for Tomorrow. Mahwah, NJ: Lawrence Erlbaum Associates. Kolb , D. (1984). Experiential learning : Experiences...development tools, job aides, or other on-the-job leader development interventions. Implicitly, the handbook employs adult learning theory to engage...most effective and efficient methods of leader development for a unit environment. Principles of adult learning theory were then applied to

Trees: Dead or Alive. 4-H Leader's Guide 147-L-22.

ERIC Educational Resources Information Center

Krasny, Marianne E.

This illustrated leader's guide to exploring trees and forests provides activities which emphasize careful observation of trees and the living things associated with them for youths age 9 and older. Introductory information for leaders explains the uses for trees and the role of trees in the ecosystem. It also gives suggestions for leaders to…

Understanding Mentoring in Leadership Development: Perspectives of District Administrators and Aspiring Leaders

ERIC Educational Resources Information Center

Clayton, Jennifer K.; Sanzo, Karen L.; Myran, Steve

2013-01-01

According to Daresh, collaboration between veteran and new or aspiring leaders can promote an environment that is conducive to high levels of student achievement. This study sought to understand the mentoring relationship between veteran school leaders and aspiring leaders within a district that is in Year 2 of a School Leadership Program grant.…

How External Institutions Penetrate Schools through Formal and Informal Leaders

ERIC Educational Resources Information Center

Sun, Min; Frank, Kenneth A.; Penuel, William R.; Kim, Chong Min

2013-01-01

Purposes: This study investigates the role of formal and informal leaders in the diffusion of external reforms into schools and to teachers' practices. Formal leaders are designated by their roles in the formal organization of the school (e.g., principals, department chairs, and instructional coaches) and informal leaders refer to those who do not…

The Key to Leadership Effectiveness--Leader Authenticity.

ERIC Educational Resources Information Center

Henderson, James E.

When an education leader develops and maintains policies that line up with the imperatives of ethical and authentic behavior, this defines the character of both the leader and the organization. Some of the questions surrounding this assertion are examined in this paper. It looks at what it means when a leader behaves in an authentic fashion, how…

The Empowerment of Academic Women Leaders at Saudi Universities and Its Relationship to Their Administrative Creativity

ERIC Educational Resources Information Center

Al Ghamdi, Azala M.

2016-01-01

The purpose of this quantitative study was to examine the influence of leaders' sense of psychological empowerment for women leaders on those leaders' administrative creativity in both established and emerging universities in Saudi Arabia. The five guiding research questions were used at both established and emerging Saudi universities: (1) what…

The Development and Support of Teacher Leaders in Ohio: A Grounded Theory Study

ERIC Educational Resources Information Center

Ross, Jennifer Elaine

2015-01-01

The purpose of this grounded theory study was to explore and conceptualize how teacher leaders are trained, developed, and supported both formally and informally to be effective in their roles. The study furthered examined teachers perceptions of the Ohio teacher leader endorsement and its impact on them as teacher leaders. The study was conducted…

Attractiveness and Leader Style: Evaluations of Male and Female Leaders by Male and Female Evaluators.

ERIC Educational Resources Information Center

Sopasakis, Maria; Snodgrass, Sara E.

Previous research has suggested that men are stereotypically believed to be better leaders than women; that more physically attractive people are evaluated more positively than less attractive people; and that men and women use different leadership styles. This study examined the interactions of sex, leader style, and physical attractiveness on…

The Impact of Doctoral Study on Educational Leaders' Work for Students' Participation in Education Systems and Society

ERIC Educational Resources Information Center

Taysum, Alison

2013-01-01

This paper examines ways educational leaders engaging with doctoral research have worked for students' participation in education systems. Twenty-four interviews were conducted with educational leaders of schools, colleges, and districts in England and the US doing doctoral research. The findings reveal that the leaders identify US and English…

Decision-Making, Information Communication Technology, and Data Analysis by School Leaders about Student Achievement

ERIC Educational Resources Information Center

Akoma, Ahunna Margaux

2012-01-01

This case study of one school district examined how school leaders use student performance data and technology-based data analysis tools to engage in data-informed decision-making for continuous improvement. School leaders in this context included leaders at the district, school, and classroom levels. An extensive literature review provided the…

Disruption of Neurexin 1 Associated with Autism Spectrum Disorder

PubMed Central

Kim, Hyung-Goo; Kishikawa, Shotaro; Higgins, Anne W.; Seong, Ihn-Sik; Donovan, Diana J.; Shen, Yiping; Lally, Eric; Weiss, Lauren A.; Najm, Juliane; Kutsche, Kerstin; Descartes, Maria; Holt, Lynn; Braddock, Stephen; Troxell, Robin; Kaplan, Lee; Volkmar, Fred; Klin, Ami; Tsatsanis, Katherine; Harris, David J.; Noens, Ilse; Pauls, David L.; Daly, Mark J.; MacDonald, Marcy E.; Morton, Cynthia C.; Quade, Bradley J.; Gusella, James F.

2008-01-01

Autism is a neurodevelopmental disorder of complex etiology in which genetic factors play a major role. We have implicated the neurexin 1 (NRXN1) gene in two independent subjects who display an autism spectrum disorder (ASD) in association with a balanced chromosomal abnormality involving 2p16.3. In the first, with karyotype 46,XX,ins(16;2)(q22.1;p16.1p16.3)pat, NRXN1 is directly disrupted within intron 5. Importantly, the father possesses the same chromosomal abnormality in the absence of ASD, indicating that the interruption of α-NRXN1 is not fully penetrant and must interact with other factors to produce ASD. The breakpoint in the second subject, with 46,XY,t(1;2)(q31.3;p16.3)dn, occurs ∼750 kb 5′ to NRXN1 within a 2.6 Mb genomic segment that harbors no currently annotated genes. A scan of the NRXN1 coding sequence in a cohort of ASD subjects, relative to non-ASD controls, revealed that amino acid alterations in neurexin 1 are not present at high frequency in ASD. However, a number of rare sequence variants in the coding region, including two missense changes in conserved residues of the α-neurexin 1 leader sequence and of an epidermal growth factor (EGF)-like domain, respectively, suggest that even subtle changes in NRXN1 might contribute to susceptibility to ASD. PMID:18179900

RNA sequencing uncovers antisense RNAs and novel small RNAs in Streptococcus pyogenes.

PubMed

Le Rhun, Anaïs; Beer, Yan Yan; Reimegård, Johan; Chylinski, Krzysztof; Charpentier, Emmanuelle

2016-01-01

Streptococcus pyogenes is a human pathogen responsible for a wide spectrum of diseases ranging from mild to life-threatening infections. During the infectious process, the temporal and spatial expression of pathogenicity factors is tightly controlled by a complex network of protein and RNA regulators acting in response to various environmental signals. Here, we focus on the class of small RNA regulators (sRNAs) and present the first complete analysis of sRNA sequencing data in S. pyogenes. In the SF370 clinical isolate (M1 serotype), we identified 197 and 428 putative regulatory RNAs by visual inspection and bioinformatics screening of the sequencing data, respectively. Only 35 from the 197 candidates identified by visual screening were assigned a predicted function (T-boxes, ribosomal protein leaders, characterized riboswitches or sRNAs), indicating how little is known about sRNA regulation in S. pyogenes. By comparing our list of predicted sRNAs with previous S. pyogenes sRNA screens using bioinformatics or microarrays, 92 novel sRNAs were revealed, including antisense RNAs that are for the first time shown to be expressed in this pathogen. We experimentally validated the expression of 30 novel sRNAs and antisense RNAs. We show that the expression profile of 9 sRNAs including 2 predicted regulatory elements is affected by the endoribonucleases RNase III and/or RNase Y, highlighting the critical role of these enzymes in sRNA regulation.

Exploration of sequence space as the basis of viral RNA genome segmentation.

PubMed

Moreno, Elena; Ojosnegros, Samuel; García-Arriaza, Juan; Escarmís, Cristina; Domingo, Esteban; Perales, Celia

2014-05-06

The mechanisms of viral RNA genome segmentation are unknown. On extensive passage of foot-and-mouth disease virus in baby hamster kidney-21 cells, the virus accumulated multiple point mutations and underwent a transition akin to genome segmentation. The standard single RNA genome molecule was replaced by genomes harboring internal in-frame deletions affecting the L- or capsid-coding region. These genomes were infectious and killed cells by complementation. Here we show that the point mutations in the nonstructural protein-coding region (P2, P3) that accumulated in the standard genome before segmentation increased the relative fitness of the segmented version relative to the standard genome. Fitness increase was documented by intracellular expression of virus-coded proteins and infectious progeny production by RNAs with the internal deletions placed in the sequence context of the parental and evolved genome. The complementation activity involved several viral proteins, one of them being the leader proteinase L. Thus, a history of genetic drift with accumulation of point mutations was needed to allow a major variation in the structure of a viral genome. Thus, exploration of sequence space by a viral genome (in this case an unsegmented RNA) can reach a point of the space in which a totally different genome structure (in this case, a segmented RNA) is favored over the form that performed the exploration.

Effects of being a peer-leader in an eating disorder prevention program: can we further reduce eating disorder risk factors?

PubMed

Black Becker, Carolyn; Bull, Stephanie; Smith, Lisa M; Ciao, Anna C

2008-01-01

Studies regarding the effect of peer-leadership on peer-leaders in prevention programs remain extremely limited. In this study, 83 undergraduate sorority members, who previously participated in the program, served as peer-leaders for an eating disorder prevention program. Peer-leaders attended 9 hours of training and then led two 2-hour sessions. Leaders showed decreases (beyond participation in earlier studies) in dietary restraint, bulimic pathology, body dissatisfaction, and thin-ideal internalization from pre-training through 7-week follow up. Results from this exploratory study suggest that peer-leaders who participate in a program and subsequently lead it may experience additional benefits compared to participation in the program alone.

Associations between a Leader's Work Passion and an Employee's Work Passion: A Moderated Mediation Model.

PubMed

Li, Jingjing; Zhang, Jian; Yang, Zhiguo

2017-01-01

Based on the theory of emotional contagion and goal content, this study explored the positive associations between a leader's work passion and employees' work passion. This study investigated 364 employees and their immediate leaders from China, constructed a moderated mediation model, and used SPSS-PROCESS in conjunction with the Johnson-Neyman technique to analyze the data. The results showed that a leader's work passion was transferred to employees via emotional contagion, and the contagion process was moderated by leader-employee goal content congruence. This study provides a potential way to stimulate employees' work passion from the perspective of leader-employee interactions. Moreover, the limitations of the study and potential topics for future research are discussed.

Modelling the public opinion transmission on social networks under opinion leaders

NASA Astrophysics Data System (ADS)

Li, Zuozhi; Li, Meng; Ji, Wanwan

2017-06-01

In this paper, based on Social Network Analysis (SNA), the social network model of opinion leaders influencing the public opinion transmission is explored. The hot event, A Female Driver Was Beaten Due To Lane Change, has characteristics of individual short-term and non-government intervention, which is used to data extraction, and formed of the network structure on opinion leaders influencing the public opinion transmission. And the evolution mechanism are analyzed in the three evolutionary situations. Opinion leaders influence micro-blogging public opinion on social network evolution model shows that this type of network public opinion transmission is largely constrained by opinion leaders, so the opinion leaders behavior supervising on the spread of this public opinion is pivotal, and which has a guiding significance.

Role congruity theory of prejudice toward female leaders.

PubMed

Eagly, Alice H; Karau, Steven J

2002-07-01

A role congruity theory of prejudice toward female leaders proposes that perceived incongruity between the female gender role and leadership roles leads to 2 forms of prejudice: (a) perceiving women less favorably than men as potential occupants of leadership roles and (b) evaluating behavior that fulfills the prescriptions of a leader role less favorably when it is enacted by a woman. One consequence is that attitudes are less positive toward female than male leaders and potential leaders. Other consequences are that it is more difficult for women to become leaders and to achieve success in leadership roles. Evidence from varied research paradigms substantiates that these consequences occur, especially in situations that heighten perceptions of incongruity between the female gender role and leadership roles.

Transcription attenuation is the major mechanism by which the leu operon of Salmonella typhimurium is controlled.

PubMed

Searles, L L; Wessler, S R; Calvo, J M

1983-01-25

Three mutations, each causing constitutive expression of the Salmonella typhimurium leu operon, were cloned into phage vector lambda gt4 on EcoRI DNA fragments carrying all of that operon except for part of the promoter-distal last gene. Sequence analysis of DNA from these phage demonstrated that each contains a single base change in the leu attenuator. Transcription of mutant DNA in vitro resulted in transcription beyond the usual site of termination. The level of beta-IPM dehydrogenase, the leuB enzyme, was elevated 40-fold in a strain carrying one of these mutations, and starvation of this strain for leucine had little effect on the amount of activity expressed. Using a strain with a wild-type promoter-leader region of the leu operon, the rates of synthesis and degradation of leu leader RNA and readthrough RNA (leu mRNA) were measured by DNA-RNA hybridizations with specific DNA probes. The rate of synthesis of the leu leader was about the same in cells grown with excess or with limiting leucine. On the other hand, the rate of synthesis of leu mRNA was 12-fold higher for cells grown in limiting leucine as opposed to excess leucine. The rate of degradation of these RNA species was the same under both conditions of growth. Thus, the variation in expression of the leu operon observed for cells grown in minimal medium is, for the most part, not caused by control over the frequency of initiation or by the differential stability of these RNA species. Rather, the variation is a direct result of the frequency of transcription termination at an attenuator site. These results taken together suggest that transcription attenuation is the major mechanism by which leucine regulates expression of the leu operon of S. typhimurium for cells growing in a minimal medium.

Leadership in nursing: The importance of recognising inherent values and attributes to secure a positive future for the profession.

PubMed

Scully, Natashia Josephine

2015-01-01

Nursing is a dynamic and challenging profession requiring engaging and inspiring role models and leaders. In today's ever changing and demanding healthcare environment, identifying and developing nurse leaders is one of the greatest challenges faced by the nursing profession. The concept of leadership is a complex and multi-dimensional phenomenon; research conducted for over a century concludes that although it is one of the most observed concepts, no universally accepted definition or theory of leadership actually exists. There is increasing clarity surrounding what true nursing leadership is, and how it differs from management. This discussion will outline the nature of nursing leadership and importance of nurse leaders in advancing the profession; clarify definitions and differentiate between nurse managers and nurse leaders; describe the evolution of nurse leadership by identify theories and styles of leadership relevant to nursing practice; and highlight the importance of identifying leaders in the nursing profession. The paper also serves as a caution to recognise, avoid and discourage "negative" leaders in the pursuit of a bright future for the nursing profession. With appropriate identification, support and development of future nurse leaders, an acknowledgement of the shifting paradigm of leadership theory and the context in which future nurse leaders are destined to grow, the ultimate goal of the nursing profession--excellent in person centred care--can be achieved. It is essential to the future success of the nursing profession that informal, negative "leaders" be discouraged and positive leaders, possessing the evidence-based qualities of leadership be identified and nurtured to lead the profession.

Expanding on the relationship between continuing current and in-cloud leader growth

NASA Astrophysics Data System (ADS)

Lapierre, Jeff L.; Sonnenfeld, Richard G.; Stock, Michael; Krehbiel, Paul R.; Edens, Harald E.; Jensen, Daniel

2017-04-01

When lightning connects to the ground, there is a large surge of current, called the return stroke, which is occasionally followed by a longer-lasting steady current, called continuing current (CC). In a previous study of negative cloud-to-ground (-CG) flashes, we observed the growth rate of in-cloud positive leaders in an attempt to identify occurrences of CC. However, there was no observed change in positive leader growth rate during CC of negative CG flashes. In this study, we use the Langmuir Electric Field Array, Lightning Mapping Array, and Flash-Continuous Broadband Digital Interferometer data to extend the previous study to the growth of the negative leader during positive CG flashes. We have found that in contrast with previous results, negative leader growth during positive CG flashes does show increases in growth rates coincident with CC. Finally, we find that the growth rate magnitudes for positive and negative leaders are typically ˜2-4 km/10 ms and ˜25-40 km/10 ms, respectively. These contrasting results highlight the differences between positive and negative leaders and provide strong evidence as to why -CC and +CC behave differently. Negative leaders inject higher amounts of current and allow the channel to remain conductive throughout the duration of CC. Whereas for positive leaders, the channel becomes nonconductive relatively quickly. It is therefore disconnected from the channel to the ground, and, due to the positive leader's continued growth, an electric potential is built up until a K event is produced that re-ionizes the channel.

Empowering peer group leaders for HIV prevention in Malawi.

PubMed

McCreary, Linda L; Kaponda, Chrissie P N; Davis, Kristina; Kalengamaliro, Mary; Norr, Kathleen F

2013-09-01

Behavioral change interventions using peer group leaders are effective and widely used, but few studies have examined how being a peer group leader affects the leaders. This study describes how participants felt being a peer group leader affected their lives. This descriptive qualitative study interviewed 18 experienced peer group leaders who had conducted a multisession human immunodeficiency virus (HIV) prevention peer group intervention in rural Malawi. We used inductive content analysis and comparisons within and between cases. Three major themes were identified. All leaders said they experienced personal changes in their knowledge, attitudes, or HIV prevention behaviors. They described interacting with family, neighbors, and friends, and speaking at church or community meetings, to discuss HIV prevention issues. They increased their self-efficacy to engage others in sensitive HIV prevention issues, developed a self-identity as a change agent, and came to be recognized in their community as trustworthy advisors about HIV and acquired immunodeficiency syndrome. These three themes, taken together, form the meta-theme of psychological empowerment. Being a peer group leader empowered the leaders as change agents for HIV prevention and had impacts in the community after the intervention ended, potentially increasing the long-term effectiveness and cost effectiveness of peer group interventions. Healthcare workers and community volunteers who led HIV prevention sessions continued HIV prevention activities in the community and workplace after the program ended. Training health workers as volunteer HIV prevention leaders offers a strategy to bring HIV prevention to limited-resource settings, despite health worker shortages. © 2013 Sigma Theta Tau International.

Leaders' smiles reflect cultural differences in ideal affect.

PubMed

Tsai, Jeanne L; Ang, Jen Ying Zhen; Blevins, Elizabeth; Goernandt, Julia; Fung, Helene H; Jiang, Da; Elliott, Julian; Kölzer, Anna; Uchida, Yukiko; Lee, Yi-Chen; Lin, Yicheng; Zhang, Xiulan; Govindama, Yolande; Haddouk, Lise

2016-03-01

Cultures differ in the emotions they teach their members to value ("ideal affect"). We conducted 3 studies to examine whether leaders' smiles reflect these cultural differences in ideal affect. In Study 1, we compared the smiles of top-ranked American and Chinese government leaders, chief executive officers, and university presidents in their official photos. Consistent with findings that Americans value excitement and other high-arousal positive states more than Chinese, American top-ranked leaders (N = 98) showed more excited smiles than Chinese top-ranked leaders (N = 91) across occupations. In Study 2, we compared the smiles of winning versus losing political candidates and higher versus lower ranking chief executive officers and university presidents in the United States and Taiwan/China. American leaders (N = 223) showed more excited smiles than Taiwanese/Chinese leaders (N = 266), regardless of election outcome or ranking. In Study 3, we administered self-report measures of ideal affect in college student samples from 10 different nations (N = 1,267) and then 8 years later, coded the smiles that legislators from those nations showed in their official photos (N = 3,372). The more nations valued excitement and other high arousal positive states, the more their leaders showed excited smiles; similarly, the more nations valued calm and other low-arousal positive states, the more their leaders showed calm smiles. These results held after controlling for national differences in democratization, human development, and gross domestic product per capita. Together, these findings suggest that leaders' smiles reflect the affective states valued by their cultures. (c) 2016 APA, all rights reserved).

Leader emergence through interpersonal neural synchronization

PubMed Central

Jiang, Jing; Chen, Chuansheng; Dai, Bohan; Shi, Guang; Ding, Guosheng; Liu, Li; Lu, Chunming

2015-01-01

The neural mechanism of leader emergence is not well understood. This study investigated (i) whether interpersonal neural synchronization (INS) plays an important role in leader emergence, and (ii) whether INS and leader emergence are associated with the frequency or the quality of communications. Eleven three-member groups were asked to perform a leaderless group discussion (LGD) task, and their brain activities were recorded via functional near infrared spectroscopy (fNIRS)-based hyperscanning. Video recordings of the discussions were coded for leadership and communication. Results showed that the INS for the leader–follower (LF) pairs was higher than that for the follower–follower (FF) pairs in the left temporo-parietal junction (TPJ), an area important for social mentalizing. Although communication frequency was higher for the LF pairs than for the FF pairs, the frequency of leader-initiated and follower-initiated communication did not differ significantly. Moreover, INS for the LF pairs was significantly higher during leader-initiated communication than during follower-initiated communications. In addition, INS for the LF pairs during leader-initiated communication was significantly correlated with the leaders’ communication skills and competence, but not their communication frequency. Finally, leadership could be successfully predicted based on INS as well as communication frequency early during the LGD (before half a minute into the task). In sum, this study found that leader emergence was characterized by high-level neural synchronization between the leader and followers and that the quality, rather than the frequency, of communications was associated with synchronization. These results suggest that leaders emerge because they are able to say the right things at the right time. PMID:25831535

Engaging religious leaders to support HIV prevention and care for gays, bisexual men, and other men who have sex with men in coastal Kenya.

PubMed

Gichuru, Evans; Kombo, Bernadette; Mumba, Noni; Sariola, Salla; Sanders, Eduard J; van der Elst, Elise M

2018-01-01

In Kenyan communities, religious leaders are important gatekeepers in matters of health and public morality. In a context that is generally homophobic, religious leaders may aggravate or reduce stigmatization of sexual minorities such as gay and bisexual men, and other men who have sex with men (GBMSM). Literature indicates mixed results in efforts to encourage religious leaders to work effectively and sensitively with issues regarding HIV and sexuality. This paper describes the implementation of an engagement intervention with religious leaders from different denominations, which took place following a homophobic hate attack that was led by local religious leaders, at an HIV research clinic for GBMSM on the Kenyan coast. After the homophobic attack, tailored engagement activities, including a comprehensive four-day online sensitivity training course took place between June 2015 and October 2016 in the Kenyan coast. HIV researchers, together with trained GBMSM activists, organized the series of engagement activities for religious leaders which unfolded iteratively, with each subsequent activity informed by the results of the previous one. Facilitated conversations were used to explore differences and disagreements in relation to questions of scripture, mission, HIV, and human sexuality. As a result, researchers noted that many religious leaders, who initially expressed exceedingly negative attitudes towards GBMSM, started to express far more accepting and supportive views of sexuality, sexual identities, and same-sex relations. This paper describes the changes in religious leaders' discourses relating to GBMSM, and highlights the possibility of using engagement interventions to build trust between research institutes, religious leaders, and GBMSM.

Perceptions of leadership and student performance in science from campus leaders in selected high schools

NASA Astrophysics Data System (ADS)

Wilder, Sharon Mae

This naturalistic study focused on the perceptions of leadership and student performance in science from campus leaders in three purposefully selected secondary campuses of ninth through twelfth grades. Each school had experienced an improvement in student passing rates on the science TAKS test that exceeded the state's percent improvement in passing rates for the past three years and had a record of improving science TAKS scores for the period of 2003 to 2008 exceeding fifteen percentage points. The qualitative research technique of multi-case studies design was used. Data was collected through semi-structured, in-depth interviews with four campus leaders from each of the selected schools. These campus leaders included campus administrators, science department chairs, and grade-level team leaders. A framework of transformational leadership was utilized in the analysis of the data generated from the interviews. The perception from the campus leaders was that leadership has a positive impact on student success in science. The findings indicated perceptions of leadership from the campus leaders had certain leadership practices in common. These included (a) clear vision and goals from the campus principal, (b) high performance expectations for teachers and students from administrators and science department leaders, (c) encouragement and support from campus administrators and science department leaders to develop new programs to address problem areas, (d) emphasis on collaborative teams, and (e) open door policy from administrators.

Solving the second-order free rider problem in a public goods game: An experiment using a leader support system

PubMed Central

Ozono, Hiroki; Jin, Nobuhito; Watabe, Motoki; Shimizu, Kazumi

2016-01-01

Punishment of non-cooperators—free riders—can lead to high cooperation in public goods games (PGG). However, second-order free riders, who do not pay punishment costs, reduce the effectiveness of punishment. Here we introduce a “leader support system,” in which one group leader can freely punish group followers using capital pooled through the support of group followers. In our experiment, participants engage in three stages repeatedly: a PGG stage in which followers decide to cooperate for their group; a support stage in which followers decide whether to support the leader; and a punishment stage in which the leader can punish any follower. We compare a support-present condition with a no-support condition, in which there is an external source for the leader’s punishment. The results show that punishment occurs more frequently in the support-present condition than the no-support condition. Within the former, both higher cooperation and higher support for a leader are achieved under linkage-type leaders—who punish both non-cooperators and non-supporters. In addition, linkage-type leaders themselves earn higher profits than other leader types because they withdraw more support. This means that leaders who effectively punish followers could increase their own benefits and the second-order free rider problem would be solved. PMID:27934871

[Effect of leader-member exchange on nurses'sense of calling in workplace].

PubMed

Zhang, L G; Ma, H L; Wang, Z J; Zhou, Y Y; Jin, T T

2017-12-20

Objective: To investigate the effect of leader-member exchange on nurses'sense of calling in workplace based on self-determination theory. Methods: A total of 381 nurses were randomly selected from five tertiary general hospitals in Zhejiang province, China from October to December, 2016. They were subjected to a survey using the Leader-Member Exchange Scale, Job Autonomy Scale, Core Self-Evaluation Scale, and Calling Scale. The mediating effect was used to test the procedures and the data were subjected to hierarchical regression analysis. Results: The leader-member exchange was positively correlated with job autonomy, core self-evaluation, and sense of calling ( r =0.471, P <0.001; r =0.373, P <0.001; r =0.475, P <0.001) ; the leader-member exchange had a positive predictive effect on job autonomy and sense of calling ( β = 0.47, P <0.001; β =0.48, P <0.001) ; the job autonomy had a partial mediating effect on the relationship between leader-member exchange and sense of calling ( F =66.50, P <0.001) ; the core self-evaluation negatively adjusted the positive relationship between leader-member exchange and job autonomy ( F =27.81, P <0.001) . Conclusion: High-quality leader-member exchange enhances the sense of calling by improving staffs' job autonomy and the core self-evaluation reduces the positive relationship between leader-member exchange and job autonomy.

Situational moderators of leader reward and punishment behaviors: fact or fiction?

PubMed

Podsakoff, P M; Todor, W D; Grover, R A; Huber, V L

1984-08-01

One assumption shared by many contemporary models of leadership is that situational variables moderate the relationships between leader behaviors and subordinate responses. Recently, however, R. J. House and J. L. Baetz (1979 in B. Staw & L. Cummings, Eds., Research in Organizational Behavior (Vol. 1), Greenwich, Connecticut, JAI Press) have suggested that the effects of some leader traits and behaviors may be relatively invariant; that is, have the same effects in a variety of situations. One possible class of leader behaviors which may have relatively consistent effects across situations are those known as leader reward and punishment behaviors. The first goal of the research reported here was to increase our understanding of the relationships between leader contingent and noncontingent reward and punishment behaviors and subordinate responses. Contingent reward behavior was found to have the most pronounced relationships with subordinate performance and satisfaction, followed by noncontingent punishment behavior. Neither leader noncontingent reward nor contingent punishment behavior were found to be related to either subordinate performance or satisfaction, with the exception that noncontingent reward behavior was negatively related to subordinates' satisfaction with work. The second goal of the research was to examine the effects of a variety of potential moderators on the relationships between leader reward and punishment behaviors and subordinate responses. The results of this study suggest that the relationships between leader reward and punishment behaviors and subordinates' performance are relatively free of moderating effects.

Cleavage of precursors by the mitochondrial processing peptidase requires a compatible mature protein or an intermediate octapeptide

PubMed Central

1991-01-01

Many precursors of mitochondrial proteins are processed in two successive steps by independent matrix peptidases (MPP and MIP), whereas others are cleaved in a single step by MPP alone. To explain this dichotomy, we have constructed deletions of all or part of the octapeptide characteristic of a twice cleaved precursor (human ornithine transcarbamylase [pOTC]), have exchanged leader peptide sequences between once-cleaved (human methylmalonyl-CoA mutase [pMUT]; yeast F1ATPase beta-subunit [pF1 beta]) and twice-cleaved (pOTC; rat malate dehydrogenase (pMDH); Neurospora ubiquinol-cytochrome c reductase iron-sulfur subunit [pFe/S]) precursors, and have incubated these proteins with purified MPP and MIP. When the octapeptide of pOTC was deleted, or when the entire leader peptide of a once-cleaved precursor (pMUT or pF1 beta) was joined to the mature amino terminus of a twice-cleaved precursor (pOTC or pFe/S), no cleavage was produced by either protease. Cleavage of these constructs by MPP was restored by re- inserting as few as two amino-terminal residues of the octapeptide or of the mature amino terminus of a once-cleaved precursor. We conclude that the mature amino terminus of a twice-cleaved precursor is structurally incompatible with cleavage by MPP; such proteins have evolved octapeptides cleaved by MIP to overcome this incompatibility. PMID:1672532

5 CFR 532.261 - Special wage schedules for leader and supervisory schedules for leader and supervisory wage...

Code of Federal Regulations, 2012 CFR

2012-01-01

... supervisory schedules for leader and supervisory wage employees in the Puerto Rico wage area. 532.261 Section... schedules for leader and supervisory wage employees in the Puerto Rico wage area. (a) The Department of... the Puerto Rico wage area. (c) The step 2 rate for the supervisory wage schedule shall be: (1) For...

5 CFR 532.261 - Special wage schedules for leader and supervisory schedules for leader and supervisory wage...

Code of Federal Regulations, 2014 CFR

2014-01-01

... supervisory schedules for leader and supervisory wage employees in the Puerto Rico wage area. 532.261 Section... schedules for leader and supervisory wage employees in the Puerto Rico wage area. (a) The Department of... the Puerto Rico wage area. (c) The step 2 rate for the supervisory wage schedule shall be: (1) For...

5 CFR 532.261 - Special wage schedules for leader and supervisory schedules for leader and supervisory wage...

Code of Federal Regulations, 2011 CFR

2011-01-01

... supervisory schedules for leader and supervisory wage employees in the Puerto Rico wage area. 532.261 Section... schedules for leader and supervisory wage employees in the Puerto Rico wage area. (a) The Department of... the Puerto Rico wage area. (c) The step 2 rate for the supervisory wage schedule shall be: (1) For...

5 CFR 532.261 - Special wage schedules for leader and supervisory schedules for leader and supervisory wage...

Code of Federal Regulations, 2010 CFR

2010-01-01

... supervisory schedules for leader and supervisory wage employees in the Puerto Rico wage area. 532.261 Section... schedules for leader and supervisory wage employees in the Puerto Rico wage area. (a) The Department of... the Puerto Rico wage area. (c) The step 2 rate for the supervisory wage schedule shall be: (1) For...

5 CFR 532.261 - Special wage schedules for leader and supervisory schedules for leader and supervisory wage...

Code of Federal Regulations, 2013 CFR

2013-01-01

... supervisory schedules for leader and supervisory wage employees in the Puerto Rico wage area. 532.261 Section... schedules for leader and supervisory wage employees in the Puerto Rico wage area. (a) The Department of... the Puerto Rico wage area. (c) The step 2 rate for the supervisory wage schedule shall be: (1) For...

Learning to Be Reflective Leaders: A Case Study from the NCCHC Hispanic Leadership Fellows Program

ERIC Educational Resources Information Center

Sullivan, Leila Gonzalez; Wiessner, Colleen Aalsburg

2010-01-01

In the constantly changing environment of today's community college, the practice of reflection may be of great value to new generations of leaders. How, then, do emerging leaders, and even seasoned ones, develop a disposition for and habit of reflection? This article suggests ways to do just that. Emerging leaders of community colleges are very…

Social Justice in India: Perspectives from School Leaders in Diverse Contexts

ERIC Educational Resources Information Center

Richardson, Jayson W.; Sauers, Nicholas J.

2014-01-01

This study focuses on social justice from the perspective of five school leaders in Delhi, India. Four of the schools in the study are affluent. One school serves primarily students who live in extreme poverty. Through interviewing these leaders, two major themes were identified. First, these leaders tended to view human rights as a driver of a…

Leading by Following: An Analysis of How K-12 School Leaders Use Twitter

ERIC Educational Resources Information Center

Sauers, Nicholas J.; Richardson, Jayson W.

2015-01-01

This study analyzed how active Twitter users who are also school leaders used the tool. The researchers collaboratively identified K-12 school leaders who were active on Twitter and then collected tweets from those school leaders. The final sample for this study included 115 Twitter users and over 180,000 tweets from those individuals. The results…

School Leaders' Problem Framing: A Sense-Making Approach to Problem-Solving Processes of Beginning School Leaders

ERIC Educational Resources Information Center

Sleegers, Peter; Wassink, Hartger; van Veen, Klaas; Imants, Jeroen

2009-01-01

In addition to cognitive research on school leaders' problem solving, this study focuses on the situated and personal nature of problem framing by combining insights from cognitive research on problem solving and sense-making theory. The study reports the results of a case study of two school leaders solving problems in their daily context by…

How Do Outdoor Leaders Feel Connected to Nature Places? A Q-Method Inquiry

ERIC Educational Resources Information Center

Hutson, Garrett; Montgomery, Diane

2006-01-01

Outdoor leaders have an opportunity to promote and facilitate a bond with the out- of-doors, yet little research has been conducted to describe the evolving relationships between outdoor leaders and the natural environments with which they come into contact. The purpose of this study was to describe the perceptions of outdoor leaders toward the…

Male Educational Leadership in Greek Primary Schools: A Theoretical Framework Based on Experiences of Male School Leaders

ERIC Educational Resources Information Center

Brinia, Vassiliki

2011-01-01

Purpose: The purpose of this paper can be summarized in the following research questions: How do male school leaders perceive the role of an educational leader and educational leadership in general? What are some of the male school leaders' leadership styles and features? What distinctive factors influence and hinder the leadership process for men…

School Leaders' Perceptions of School Counselors as Leaders as Part of the District Leadership Team and Impact on the District Wide Change Process

ERIC Educational Resources Information Center

Davis, James S., Jr.

2013-01-01

This exploration focuses on school leaders' perceptions of school counselors as leaders and their involvement with district wide change. This study explores school counselor leadership, school counselors' role in district level change, and barriers to school counselor leadership. This is a qualitative study utilizing grounded theory design.…