A Practical and Stereoselective Organocatalytic Alkylation of Aldehydes with Benzodithiolylium Tetrafluoroborate

Recently, the direct substitution of allylic, benzylic, and tertiary alcohols has been achieved via S_N1‐type reactions with catalytic amounts of Brønsted or Lewis acids. When a new stereogenic center is formed most of these transformations produce the desired product as a racemate, as these reactions proceed through carbenium ions. The arsenal of activation modes available in organocatalysis can be used to set up suitable reaction conditions in which chiral nucleophiles (enamine catalysis) or chiral electrophiles (iminium catalysis, chiral counterion catalysis) can easily be generated. Recently, we have used stabilized carbenium ions, directly available or obtained from the corresponding alcohols, in new organocatalytic stereoselective S_N1‐type reactions. The commercially available carbenium ion benzodithiolylium tetrafluoroborate 1 can be used for the straightforward organocatalytic stereoselective alkylation of aldehydes. In this account we will illustrate the application of this methodology in the total synthesis of natural products and the preparation of valuable starting materials. Chirality 26:607–613, 2014. © 2014 Wiley Periodicals, Inc.     

Feasibility,Acceptability, and Potential Effectiveness of Dignity Therapy for People with Motor Neurone Disease

Background

Motor neurone disease (MND) practice guidelines suggest developing interventions that will promote hope, meaning, and dignity to alleviate psychological distress, but very little research has been done. This study begins to address this need by exploring the use of dignity therapy with people with MND. Dignity therapy is a brief psychotherapy that promotes hope, meaning and dignity, and enhances the end of life for people with advanced cancer. The aims of this study are to assess the feasibility, acceptability, and potential effectiveness of dignity therapy for people with MND.

Methods/design

This cross-sectional feasibility study used a one-group pre-test post-test design with 29 people diagnosed with MND. Study participants completed the following self-report questionnaires: Herth Hope Index, FACIT-sp, Patient Dignity Inventory, ALS Assessment Questionnaire, ALS Cognitive Behavioural Screen, and a demographic and health history questionnaire. Acceptability was measured with a 25-item feedback questionnaire. Feasibility was assessed by examining the length of time taken to complete dignity therapy and how symptoms common in MND affected the intervention. Generalised linear mixed models and reliable change scores were used to analyse the data.

Results

There were no significant pre-test post-test changes for hopefulness, spirituality or dignity on the group level, but there were changes in hopefulness on the individual level. The results of the feedback questionnaire indicates dignity therapy is highly acceptable to people with MND, who report benefits similar to those in the international randomised controlled trial on dignity therapy, a population who primarily had end-stage cancer. Benefits include better family relationships, improved sense of self and greater acceptance. Dignity therapy with people with MND is feasible if the therapist can overcome time and communication difficulties.

Conclusions

Dignity therapy for people with MND is feasible and acceptable. Further research is warranted to explore its ability to diminish distress.

Trial Registration

www.anzctr.org.au ACTRN12611000410954     

RIP4 is an ankyrin repeat-containing kinase essential for keratinocyte differentiation

The epidermis is a stratified, continually renewing epithelium dependent on a balance among cell proliferation, differentiation, and death for homeostasis. In normal epidermis, a mitotically active basal layer gives rise to terminally differentiating keratinocytes that migrate outward and are ultimately sloughed from the skin surface as enucleated squames. Although many proteins are known to function in maintaining epidermal homeostasis, the molecular coordination of these events is poorly understood. RIP4 is a novel RIP (receptor-interacting protein) family kinase with ankyrin repeats cloned from a keratinocyte cDNA library. RIP4 deficiency in mice results in perinatal lethality associated with abnormal epidermal differentiation. The phenotype of RIP4(-/-) mice in part resembles that of mice lacking IKKalpha, a component of a complex that regulates NF-kappaB. Despite the similar keratinocyte defects in RIP4- and IKKalpha-deficient mice, these kinases function in distinct pathways. RIP4 functions cell autonomously within the keratinocyte lineage. Unlike IKKalpha, RIP4-deficient skin fails to fully differentiate when grafted onto a normal host. Instead, abnormal hair follicle development and epidermal dysplasia, indicative of progression into a more pathologic state, are observed. Thus, RIP4 is a critical component of a novel pathway that controls keratinocyte differentiation.     

Modelling Co-Infection of the Cystic Fibrosis Lung by Pseudomonas aeruginosa and Burkholderia cenocepacia Reveals Influences on Biofilm Formation and Host Response

The Gram-negative bacteria Pseudomonas aeruginosa and Burkholderia cenocepacia are opportunistic human pathogens that are responsible for severe nosocomial infections in immunocompromised patients and those suffering from cystic fibrosis (CF). These two bacteria have been shown to form biofilms in the airways of CF patients that make such infections more difficult to treat. Only recently have scientists begun to appreciate the complicated interplay between microorganisms during polymicrobial infection of the CF airway and the implications they may have for disease prognosis and response to therapy.To gain insight into the possible role that interaction between strains of P. aeruginosa and B. cenocepacia may play during infection, we characterised co-inoculations of in vivo and in vitro infection models. Co-inoculations were examined in an in vitro biofilm model and in a murine model of chronic infection. Assessment of biofilm formation showed that B. cenocepacia positively influenced P. aeruginosa biofilm development by increasing biomass. Interestingly, co-infection experiments in the mouse model revealed that P. aeruginosa did not change its ability to establish chronic infection in the presence of B. cenocepacia but co-infection did appear to increase host inflammatory response.Taken together, these results indicate that the co-infection of P. aeruginosa and B. cenocepacia leads to increased biofilm formation and increased host inflammatory response in the mouse model of chronic infection. These observations suggest that alteration of bacterial behavior due to interspecies interactions may be important for disease progression and persistent infection.     

SNP Discovery with EST and NextGen Sequencing in Switchgrass (Panicum virgatum L.)

Although yield trials for switchgrass (Panicum virgatum L.), a potentially high value biofuel feedstock crop, are currently underway throughout North America, the genetic tools for crop improvement in this species are still in the early stages of development. Identification of high-density molecular markers, such as single nucleotide polymorphisms (SNPs), that are amenable to high-throughput genotyping approaches, is the first step in a quantitative genetics study of this model biofuel crop species. We generated and sequenced expressed sequence tag (EST) libraries from thirteen diverse switchgrass cultivars representing both upland and lowland ecotypes, as well as tetraploid and octoploid genomes. We followed this with reduced genomic library preparation and massively parallel sequencing of the same samples using the Illumina Genome Analyzer technology platform. EST libraries were used to generate unigene clusters and establish a gene-space reference sequence, thus providing a framework for assembly of the short sequence reads. SNPs were identified utilizing these scaffolds. We used a custom software program for alignment and SNP detection and identified over 149,000 SNPs across the 13 short-read sequencing libraries (SRSLs). Approximately 25,000 additional SNPs were identified from the entire EST collection available for the species. This sequencing effort generated data that are suitable for marker development and for estimation of population genetic parameters, such as nucleotide diversity and linkage disequilibrium. Based on these data, we assessed the feasibility of genome wide association mapping and genomic selection applications in switchgrass. Overall, the SNP markers discovered in this study will help facilitate quantitative genetics experiments and greatly enhance breeding efforts that target improvement of key biofuel traits and development of new switchgrass cultivars.     

Contemporary and historical evolutionary processes interact to shape patterns of within-lake phenotypic divergences in polyphenic pumpkinseed sunfish, Lepomis gibbosus

Historical and contemporary evolutionary processes can both contribute to patterns of phenotypic variation among populations of a species. Recent studies are revealing how interactions between historical and contemporary processes better explain observed patterns of phenotypic divergence than either process alone. Here, we investigate the roles of evolutionary history and adaptation to current environmental conditions in structuring phenotypic variation among polyphenic populations of sunfish inhabiting 12 postglacial lakes in eastern North America. The pumpkinseed sunfish polyphenism includes sympatric ecomorphs specialized for littoral or pelagic lake habitats. First, we use population genetic methods to test the evolutionary independence of within-lake phenotypic divergences of ecomorphs and to describe patterns of genetic structure among lake populations that clustered into three geographical groupings. We then used multivariate analysis of covariance (MANCOVA) to partition body shape variation (quantified with geometric morphometrics) among the effects of evolutionary history (reflecting phenotypic variation among genetic clusters), the shared phenotypic response of all populations to alternate habitats within lakes (reflecting adaptation to contemporary conditions), and unique phenotypic responses to habitats within lakes nested within genetic clusters. All effects had a significant influence on body form, but the effects of history and the interaction between history and contemporary habitat were larger than contemporary processes in structuring phenotypic variation. This highlights how divergence can be better understood against a known backdrop of evolutionary history.     

Genomic arrangement of salinity tolerance QTLs in salmonids: A comparative analysis of Atlantic salmon (Salmo salar) with Arctic charr (Salvelinus alpinus) and rainbow trout (

ABSTRACT: BACKGROUND: Quantitative trait locus (QTL) studies show that variation in salinity tolerance in Arctic charr and rainbow trout has a genetic basis, even though both these species have low to moderate salinity tolerance capacities. QTL were observed to localize to homologous linkage group segments within putative chromosomal regions possessing multiple candidate genes. We compared salinity tolerance QTL in rainbow trout and Arctic charr to those detected in a higher salinity tolerant species, Atlantic salmon. The highly derived karyotype of Atlantic salmon allows for the assessment of whether disparity in salinity tolerance in salmonids is associated with differences in genetic architecture. To facilitate these comparisons, we examined the genomic synteny patterns of key candidate genes in the other model teleost fishes that have experienced three whole-genome duplication (3R) events which preceded a fourth (4R) whole genome duplication event common to all salmonid species. RESULTS: Nine linkage groups contained chromosome-wide significant QTL (AS-2, -4p, -4q, -5, -9, -12p, -12q, -14q -17q, -22, and [MINUS SIGN]23), while a single genome-wide significant QTL was located on AS-4q. Salmonid genomes shared the greatest marker homology with the genome of three-spined stickleback. All linkage group arms in Atlantic salmon were syntenic with at least one stickleback chromosome, while 18 arms had multiple affinities. Arm fusions in Atlantic salmon were often between multiple regions bearing salinity tolerance QTL. Nine linkage groups in Arctic charr and six linkage group arms in rainbow trout currently have no synteny alignments with stickleback chromosomes, while eight rainbow trout linkage group arms were syntenic with multiple stickleback chromosomes. Rearrangements in the stickleback lineage involving fusions of ancestral arm segments could account for the 21 chromosome pairs observed in the stickleback karyotype. CONCLUSIONS: Salinity tolerance in salmonids from three genera is to some extent controlled by the same loci. Synteny between QTL in salmonids and candidate genes in stickleback suggests genetic variation at candidate gene loci could affect salinity tolerance in all three salmonids investigated. Candidate genes often occur in pairs on chromosomes, and synteny patterns indicate these pairs are generally conserved in 2R, 3R, and 4R genomes. Synteny maps also suggest that the Atlantic salmon genome contains three larger syntenic combinations of candidate genes that are not evident in any of the other 2R, 3R, or 4R genomes examined. These larger synteny tracts appear to have resulted from ancestral arm fusions that occurred in the Atlantic salmon ancestor. We hypothesize that the superior hypo-osmoregulatory efficiency that is characteristic of Atlantic salmon may be related to these clusters.     

The mentoring needs of trainees in family practice

This qualitative study examined medical students' and family practice residents' ideas, perceptions, and experiences of being mentored and their expectations of the mentoring experience. Eight focus groups and 16 individual interviews were used to collect data from 49 medical students and 29 family practice residents. Interviews and focus groups were audiotaped and transcribed verbatim. The analysis was iterative and interpretive, using both individual and team analyses. The analysis of the data revealed two central but related themes. The first theme reflected participants' overall experiences with mentors composed of three distinct elements: mentor roles (e.g. coach, advisor) and attributes (e.g. openness and approachability), interactions with mentors, and early exposure to family practice mentors (e.g. observing patient encounters). The second theme explicated the trainees' specific learning needs to be addressed by mentors that were categorised into three distinct yet overlapping levels: 1 practice level (i.e. guidance regarding the logistics of practice management) 2 system level (i.e. knowledge about the medical community as well as community resources) 3 personal level (i.e. guidance in balancing personal and professional responsibilities). Having the option of selecting multiple mentors to address unique aspects of the mentees' personal and professional development is critical in respecting the evolutionary nature and fluidity of the mentoring experience.     

Proteomic analysis of the abomasal mucosal response following infection by the nematode, Haemonchus contortus, in genetically resistant and susceptible sheep

Sheep have a variable ability to resist gastrointestinal nematode infection, but the key factors mediating this response are poorly defined. Here we report the first large-scale application of quantitative proteomic technologies to define proteins that are differentially abundant between sheep selectively bred to have an enhanced (resistant) or reduced (susceptible) ability to eliminate nematodes. Samples were collected from the abomasal mucosa three days after experimental challenge with the nematode, Haemonchus contortus. This timing reflects the initial interaction of host and parasite, and the tissue represents the immediate interface. We identified and quantified more than 4400 unique proteins, of which 158 proteins showed >1.5 fold difference between the resistant and susceptible sheep. Trefoil factor 2, a member of RAS oncogene family (RAP1A) and ring finger protein 126 were amongst the proteins found to be highly abundant in the abomasal surface of resistant sheep, whereas adenosine deaminase and the gastrokine-3 like precursor were found at higher levels in susceptible sheep. Construction of gut proteome interaction networks identified mitochondrial function and energetic partitioning as important components of an effective nematode eliminating response. The differentially abundant proteins may be useful targets for phenotypic tests that aim to identify sheep with an enhanced ability to resist nematode infection.