Fertiliser recommendations for citrus : detailed fertilizer programmes for citrus growers

CITRUS growers should adopt a well balanced fertiliser programme to safeguard tree health, cropping and fruit quality. While moderate dressings are a wise insurance in most situations the rates required vary with tree age and soil type. The recommendations are given in detail in the tables in this article

Fertiliser recommendations for apple trees

THE increased use of irrigation and chemical thinning in apple orchards and the planting of trees in light soils have resulted in responses to regular fertiliser dressings

Multi-environment QTL mixed models for drought stress adaptation in wheat

Many quantitative trait loci (QTL) detection methods ignore QTL-by-environment interaction (QEI) and are limited in accommodation of error and environment-specific variance. This paper outlines a mixed model approach using a recombinant inbred spring wheat population grown in six drought stress trials. Genotype estimates for yield, anthesis date and height were calculated using the best design and spatial effects model for each trial. Parsimonious factor analytic models best captured the variance-covariance structure, including genetic correlations, among environments. The 1RS.1BL rye chromosome translocation (from one parent) which decreased progeny yield by 13.8 g m(-2) was explicitly included in the QTL model. Simple interval mapping (SIM) was used in a genome-wide scan for significant QTL, where QTL effects were fitted as fixed environment-specific effects. All significant environment-specific QTL were subsequently included in a multi-QTL model and evaluated for main and QEI effects with non-significant QEI effects being dropped. QTL effects (either consistent or environment-specific) included eight yield, four anthesis, and six height QTL. One yield QTL co-located (or was linked) to an anthesis QTL, while another co-located with a height QTL. In the final multi-QTL model, only one QTL for yield (6 g m(-2)) was consistent across environments (no QEI), while the remaining QTL had significant QEI effects (average size per environment of 5.1 g m(-2)). Compared to single trial analyses, the described framework allowed explicit modelling and detection of QEI effects and incorporation of additional classification information about genotypes

Online Data Collection to Evaluate a Theoretical Cognitive Model of Tinnitus

Purpose The purpose of this article is to describe data collection considerations, methods, and response rates for a survey available both online and on paper. Methodological issues in the design of online data collection, and advantages and disadvantages of different data collection methods are discussed. Method A survey was compiled that included 9 full or partial clinical questionnaires designed to measure different components relevant to tinnitus distress. It was completed once by 342 members of the public with tinnitus. Respondents could choose whether to complete the survey online or on paper. Results Ninety-five percent of participants chose to complete the survey online. The advantages of an online self-administered questionnaire include low numbers of unanswered questions, convenience (particularly in a longer survey such as this), a fast return rate, and reduced expense. Age emerged as an important variable, with those opting to complete the paper-based version of the survey being older. Conclusions Online data collection has several advantages to both participants and researchers. However, cross-sectional studies such as that presented here should also offer paper questionnaires to avoid excluding certain subgroups of the population. Ethics and reporting guidelines for Internet-delivered questionnaire studies are available. These can usefully inform study design and guide high-quality reporting.Lucy Handscomb was funded by the British Tinnitus Asso-ciation. Deborah A. Hall and Derek J. Hoare were funded bythe Nat ional Institute for Health Research (NIHR) BiomedicalResearch Unit program

Predicting conversion to dementia in a memory clinic: A standard clinical approach compared with an empirically defined clustering method (latent profile analysis) for mild cognitive impairment subtyping

AbstractIntroductionMild cognitive impairment (MCI) has clinical value in its ability to predict later dementia. A better understanding of cognitive profiles can further help delineate who is most at risk of conversion to dementia. We aimed to (1) examine to what extent the usual MCI subtyping using core criteria corresponds to empirically defined clusters of patients (latent profile analysis [LPA] of continuous neuropsychological data) and (2) compare the two methods of subtyping memory clinic participants in their prediction of conversion to dementia.MethodsMemory clinic participants (MCI, n = 139) and age-matched controls (n = 98) were recruited. Participants had a full cognitive assessment, and results were grouped (1) according to traditional MCI subtypes and (2) using LPA. MCI participants were followed over approximately 2 years after their initial assessment to monitor for conversion to dementia.ResultsGroups were well matched for age and education. Controls performed significantly better than MCI participants on all cognitive measures. With the traditional analysis, most MCI participants were in the amnestic multidomain subgroup (46.8%) and this group was most at risk of conversion to dementia (63%). From the LPA, a three-profile solution fit the data best. Profile 3 was the largest group (40.3%), the most cognitively impaired, and most at risk of conversion to dementia (68% of the group).DiscussionLPA provides a useful adjunct in delineating MCI participants most at risk of conversion to dementia and adds confidence to standard categories of clinical inference

PREDICTING CONVERSION TO DEMENTIA IN A MEMORY CLINIC A STANDARD CLINICAL APPROACH COMPARED WITH AN EMPIRICALLY DEFINED CLUSTERING METHOD LATENT PROFILE ANALYSIS FOR MILD COGNITIVE IMPAIRMENT SUBTYPING

Introduction: Mild cognitive impairment (MCI) has clinical value in its ability to predict later dementia. A better understanding of cognitive profiles can further help delineate who is most at risk of conversion to dementia. We aimed to (1) examine to what extent the usual MCI subtyping using core criteria corresponds to empirically defined clusters of patients (latent profile analysis [LPA] of continuous neuropsychological data) and (2) compare the two methods of subtyping memory clinic participants in their prediction of conversion to dementia. Methods: Memory clinic participants (MCI, n = 139) and age-matched controls (n = 98) were recruited. Participants had a full cognitive assessment, and results were grouped (1) according to traditional MCI subtypes and (2) using LPA. MCI participants were followed over approximately 2 years after their initial assessment to monitor for conversion to dementia. Results: Groups were well matched for age and education. Controls performed significantly better than MCI participants on all cognitive measures. With the traditional analysis, most MCI participants were in the amnestic multidomain subgroup (46.8%) and this group was most at risk of conversion to dementia (63%). From the LPA, a three-profile solution fit the data best. Profile 3 was the largest group (40.3%), the most cognitively impaired, and most at risk of conversion to dementia (68% of the group). Discussion: LPA provides a useful adjunct in delineating MCI participants most at risk of conversion to dementia and adds confidence to standard categories of clinical inference

Tracing Spasmodic Dysphonia: the source of Ludwig Traube’s priority

Objectives: Since the mid-20th century, one citation is given historical priority as the first description of Spasmodic Dysphonia (SD): Ludwig Traube’s 1871 case of the “spastic form of nervous hoarseness”. Our objective is to understand how this case serves as the foundation of understanding laryngeal movement disorders. Methods: The original German paper was located and translated. Bibliographical and bibliometric methods are used to determine the citation history of this original source over the past 140 years. Results: Although secondary citations in contemporary publications typically credit Traube for establishing the clinical entity SD, his case does not conform to currently accepted diagnostic features. Citation patterns indicate the source of Traube’s priority is publications by Arnold and Luchsinger, mid-20th century ENT clinician, particularly their influential 1965 textbook used to train US and UK clinicians on voice disorders for several generations. Conclusions: Sometimes secondary citations in medical literature lead to the inadvertent perpetuation of factual misrepresentation. The clinical picture of Traube’s original case does not represent what clinicians would recognize as SD today. The rich 19th century literature on voice disorders is a valuable resource for present day clinicians

Mining Disaggregase Sequence Space to Safely Counter TDP-43, FUS, and α-Synuclein Proteotoxicity.

Hsp104 is an AAA+ protein disaggregase, which can be potentiated via diverse mutations in its autoregulatory middle domain (MD) to mitigate toxic misfolding of TDP-43, FUS, and α-synuclein implicated in fatal neurodegenerative disorders. Problematically, potentiated MD variants can exhibit off-target toxicity. Here, we mine disaggregase sequence space to safely enhance Hsp104 activity via single mutations in nucleotide-binding domain 1 (NBD1) or NBD2. Like MD variants, NBD variants counter TDP-43, FUS, and α-synuclein toxicity and exhibit elevated ATPase and disaggregase activity. Unlike MD variants, non-toxic NBD1 and NBD2 variants emerge that rescue TDP-43, FUS, and α-synuclein toxicity. Potentiating substitutions alter NBD1 residues that contact ATP, ATP-binding residues, or the MD. Mutating the NBD2 protomer interface can also safely ameliorate Hsp104. Thus, we disambiguate allosteric regulation of Hsp104 by several tunable structural contacts, which can be engineered to spawn enhanced therapeutic disaggregases with minimal off-target toxicity