456 research outputs found
Mentoring: Essential 2 formal and informal education
Traditionally, library mentorship programs have focused on orienting new and future librarians to the profession and/or guiding individuals toward promotion and tenure. With declining employee loyalty and the transition of libraries from gatekeepers of information to places of creation and innovation, there is a need for mentoring to focus on retention via the development of leadership skills and confidence building along with employee satisfaction and personal support for new employees.
Additionally, motivation is a key tool to get library staff involved in library science program opportunities which can then be translated into âretention possibilitiesâ. Furthermore, creating an open environment that stimulates opportunities for natural collaborations to occur is essential for developing professionals. The presenters shared their mentor-mentee experience from three distinct roles within the profession. The audience contributed their ideas on the new age of mentorship and the presenters discussed how their mentoring experiences have developed their leadership skills in order to engage in new opportunities and challenges. The presentation discussed different types of mentoring programs including formal and informal and the advantages and disadvantages of each. Additionally, the presentation addressed demographic statistics and how there is a need for mentoring programs to support the growing number of minority librarians entering the profession.
Finally, the presentation shared the results of a survey focused on the benefits and types of mentoring programs available to Florida library employees. The survey results helped to understand what types of mentoring programs exist as a way to analyze the needs of the Florida library community
The amino-terminal segment in the β-domain of δ-cadinene synthase is essential for catalysis
Despite its distance from the active site the flexible amino-terminal segment (NTS) in the β-domain of the plant sesquiterpene cyclase δ-cadinene synthase (DCS) is essential for active site closure and desolvation events during catalysis
Nucleophilic water capture or proton loss: single amino acid switch converts δ-Cadinene synthase into germacradien-4-ol synthase
δ-Cadinene synthase is a sesquiterpene cyclase that utilises the universal achiral precursor farnesyl diphosphate (FDP) to generate predominantly the bicyclic sesquiterpene δ-cadinene and about 2â% germacradien-4-ol, which is also generated from FDP by the cyclase germacradien-4-ol synthase. Herein, the mechanism by which sesquiterpene synthases discriminate between deprotonation and reaction with a nucleophilic water molecule was investigated by site-directed mutagenesis of δ-cadinene synthase. If W279 in δ-cadinene synthase was replaced with various smaller amino acids, the ratio of alcohol versus hydrocarbon product was directly proportional to the van der Waals volume of the amino acid side chain. DCS-W279A is a catalytically highly efficient germacradien-4-ol synthase (kcat/KM=1.4Ă10â3â
Îźmâsâ1) that produces predominantly germacradien-4-ol in addition to 11â% δ-cadinene. Water capture is not achieved through strategic positioning of a water molecule in the active site, but through a coordinated series of loop movements that allow bulk water access to the final carbocation in the active site prior to product release
High Trait Anger, Interpersonal Context, and the Recognition of Anger Problems
Background: High trait anger is usually destructive for individuals and their relationships. This proneness to anger is reflected in frequent angry feelings, for longer periods of time, and with higher levels of physical arousal and negative expressions (e.g., insulting or arguing with others). Unfortunately, not all individuals with high trait anger recognize the problem. Objective: This research assessed the contribution of the interpersonal context (e.g., family members, friends, and boyfriend/girlfriend) to recognize anger problems. Methods: We recruited 192 individuals with high trait anger who completed questionnaires about 1) recognition of anger problems, 2) how they are perceived by others in terms of anger (i.e., âbeing irascibleâ), and 3) if they care about what others think about their anger. Research Design: Cross-sectional. Results: Individuals who recognized their anger problems perceived they have received more messages of âYou are very irascibleâ from their social contexts, while those who do not recognize anger problems, have received these messages less often. Moreover, the higher the extent to which the individuals care about what other people think or say about their anger (i.e., higher importance attached to messages from others), the more it contributed to a higher recognition of anger problems. In addition, a lower importance attached to such messages was related to a lower recognition of such problems. Recognition of anger problems was higher in participants who had a boyfriend/girlfriend (versus those who did not have one), and in female (versus male) participants
Acoustic identification of Mexican bats based on taxonomic and ecological constraints on call design
1. Monitoring global biodiversity is critical for understanding responses to anthropogenic change, but biodiversity monitoring is often biased away from tropical, megadiverse areas that are experiencing more rapid environmental change. Acoustic surveys are increasingly used to monitor biodiversity change, especially for bats as they are important indicator species and most use sound to detect, localise and classify objects. However, using bat acoustic surveys for monitoring poses several challenges, particularly in mega-diverse regions. Many species lack reference recordings, some species have high call similarity or differ in call detectability, and quantitative classification tools, such as machine learning algorithms, have rarely been applied to data from these areas. 2. Here, we collate a reference call library for bat species that occur in a megadiverse country, Mexico. We use 4,685 search-phase calls from 1,378 individual sequences of 59 bat species to create automatic species identification tools generated by machine learning algorithms (Random Forest). We evaluate the improvement in species-level classification rates gained by using hierarchical classifications, reflecting either taxonomic or ecological constraints (guilds) on call design, and examine how classification rate accuracy changes at different hierarchical levels (family, genus, and guild). 3. Species-level classification of calls had a mean accuracy of 66% and the use of hierarchies improved mean species-level classification accuracy by up to 6% (species within families 72%, species within genera 71.2% and species within guilds 69.1%). Classification accuracy to family, genus and guild-level was 91.7%, 77.8% and 82.5%, respectively. 4. The bioacoustic identification tools we have developed are accurate for rapid biodiversity assessments in a megadiverse region and can also be used effectively to classify species at broader taxonomic or ecological levels. This flexibility increases their usefulness when there are incomplete species reference recordings and also offers the opportunity to characterise and track changes in bat community structure. Our results show that bat bioacoustic surveys in megadiverse countries have more potential than previously thought to monitor biodiversity changes and can be used to direct further developments of bioacoustic monitoring programs in Mexico
Evolutionary and mechanistic insights from the reconstruction of Îą-humulene synthases from a modern (+)-Germacrene A synthase
Germacrene A synthase (GAS) from Solidago canadensis catalyzes the conversion of farnesyl diphosphate (FDP) to the plant sesquiterpene (+)-germacrene A. After diphosphate expulsion, farnesyl cation reacts with the distal 10,11-double bond to afford germacrene A (>96%) and <2% Îą-humulene, which arises from 1,11-cyclization of FDP. The origin of the 1,11-activity of GAS was investigated by amino acid sequence alignments of 1,10- and 1,11-synthases and comparisons of X-ray crystal structures with the homology model of GAS; a triad [Thr 401-Gly 402-Gly 403] that might be responsible for the predominant 1,10-cyclization activity of GAS was identified. Replacement of Gly 402 with residues of increasing size led to a progressive increase of 1,11-cyclization. The catalytic robustness of these 1,10- /1,11-GAS variants point to Gly 402 as a functional switch of evolutionary significance and suggests that enzymes with strict functionalities have evolved from less specific ancestors through a small number of substitutions. Similar results were obtained with germacrene D synthase (GDS) upon replacement of the homologous active-site residue Gly 404: GDS-G404V generated approximately 20% bicyclogermacrene, a hydrocarbon with a cyclopropane ring that underlines the dual 1,10-/1,11-cyclization activity of this mutant. This suggests that the reaction pathways to germacrenes and humulenes might be connected through a bridged 1,10,11-carbocation intermediate or transition state that resembles bicyclogermacrene. Mechanistic studies using [1-3H1]-10-fluorofarnesyl diphosphate and deuterium-labeling experiments with [12,13-2H6]-FDP support a germacreneâhumulene rearrangement linking 1,10- and 1,11-pathways. These results support the bioinformatics proposal that modern 1,10-synthases could have evolved from promiscuous 1,11-sesquiterpene synthases
Different Impacts of Cardiovascular Risk Factors on Oxidative Stress
The objective of the study was to evaluate oxidative stress (OS) status in subjects with different cardiovascular risk factors. With this in mind, we have studied three models of high cardiovascular risk: hypertension (HT) with and without metabolic syndrome, familial hypercholesterolemia (FH) and familial combined hyperlipidemia (FCH) with and without insulin resistance. Oxidative stress markers (oxidized/reduced glutathione ratio, 8-oxo-deoxyguanosine and malondialdehide) together with the activity of antioxidant enzyme triad (superoxide dismutase, catalase, glutathione peroxidase) and activation of both pro-oxidant enzyme (NAPDH oxidase components) and AGTR1 genes, as well as antioxidant enzyme genes (CuZn-SOD, CAT, GPX1, GSR, GSS and TXN) were measured in mononuclear cells of controls (n = 20) and patients (n = 90) by assessing mRNA levels. Activity of some of these antioxidant enzymes was also tested. An increase in OS and pro-oxidant gene mRNA values was observed in patients compared to controls. The hypertensive group showed not only the highest OS values, but also the highest pro-oxidant activation compared to those observed in the other groups. In addition, in HT a significantly reduced antioxidant activity and mRNA induction of antioxidant genes were found when compared to controls and the other groups. In FH and FCH, the activation of pro-oxidant enzymes was also higher and antioxidant ones lower than in the control group, although it did not reach the values obtained in hypertensives. The thioredoxin system was more activated in patients as compared to controls, and the highest levels were in hypertensives. The increased oxidative status in the presence of cardiovascular risk factors is a consequence of both the activation of pro-oxidant mechanisms and the reduction of the antioxidant ones. The altered response of the main cytoplasmic antioxidant systems largely contributes to OS despite the apparent attempt of the thioredoxin system to control it
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Affinity of Tau antibodies for solubilized pathological Tau species but not their immunogen or insoluble Tau aggregates predicts in vivo and ex vivo efficacy
BACKGROUND: A few tau immunotherapies are now in clinical trials with several more likely to be initiated in the near future. A priori, it can be anticipated that an antibody which broadly recognizes various pathological tau aggregates with high affinity would have the ideal therapeutic properties. Tau antibodies 4E6 and 6B2, raised against the same epitope region but of varying specificity and affinity, were tested for acutely improving cognition and reducing tau pathology in transgenic tauopathy mice and neuronal cultures. RESULTS: Surprisingly, we here show that one antibody, 4E6, which has low affinity for most forms of tau acutely improved cognition and reduced soluble phospho-tau, whereas another antibody, 6B2, which has high affinity for various tau species was ineffective. Concurrently, we confirmed and clarified these efficacy differences in an ex vivo model of tauopathy. Alzheimerâs paired helical filaments (PHF) were toxic to the neurons and increased tau levels in remaining neurons. Both toxicity and tau seeding were prevented by 4E6 but not by 6B2. Furthermore, 4E6 reduced PHF spreading between neurons. Interestingly, 4E6âs efficacy relates to its high affinity binding to solubilized PHF, whereas the ineffective 6B2 binds mainly to aggregated PHF. Blocking 4E6's uptake into neurons prevented its protective effects if the antibody was administered after PHF had been internalized. When 4E6 and PHF were administered at the same time, the antibody was protective extracellularly. CONCLUSIONS: Overall, these findings indicate that high antibody affinity for solubilized PHF predicts efficacy, and that acute antibody-mediated improvement in cognition relates to clearance of soluble phospho-tau. Importantly, both intra- and extracellular clearance pathways are in play. Together, these results have major implications for understanding the pathogenesis of tauopathies and for development of immunotherapies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13024-016-0126-z) contains supplementary material, which is available to authorized users
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