A sampling strategy to assess banana crops for damage by Radopholus similis and Pratylenchus goodeyi

The economic threshold of burrowing (Radopholus similis) and lesion nematode (Pratylenchus goodeyi) on banana may be used to determine whether it is economic to apply nematicide. However, to use such a threshold, a sampling strategy is essential to determine the severity of root damage caused by the nematode. Ten banana crops in south-eastern Queensland and northern New South Wales and 10 in northern Queensland were sampled several times over several years to determine the disease index (percentage cortical root damage caused by R. similis and P. goodeyi) and nematode populations in roots. The negative binomial distribution and Taylor’s power law analysis were used to determine the relationship between the mean and variance of the disease index and nematode populations. Taylor’s power law gave the better fit, and was therefore used to determine fixed-precision stop lines for sequential sampling for precision at 20–30% for disease index and 20–40% for nematode populations. Twenty samples per crop were sufficient to achieve 25% precision when assessing nematode infestations using disease index but only 40% precision when using nematode populations

The differing approaches to sustainability between practising and academic Quantity Surveyors

Most interpretations of sustainability in construction stem from the definition of sustainable development, which is a development that meets the needs of the present without compromising the future generation’s needs. Various research and sustainability studies within the construction industry focus on finding economical, social, and environmental balance. Construction professionals, such as Quantity Surveyors, begin their learning journey by studying in colleges and progressing to higher education. As the construction industry evolves through modern techniques, higher education institutions must also follow suit. These modern techniques have arisen due to the shift of ethos towards sustainability. Without the higher education institutions including this new knowledge in their curriculum, future professionals will not be equipped with the correct skills. Few research have been conducted in relation to students’ views on sustainability. Although such research is at a minute level, thus the converse side of the argument is how professional Quantity Surveyors view these topics on sustainability and whether they implement them in their daily duties. Hence, the research explores the differences in understanding between practicing and academic Quantity Surveyors on sustainable development in their various professional duties. The research was conducted using questionnaires that was distributed using survey monkey. The results were analysed through Spearman and ANOVA statistical tests to check their correlations. The study found a difference in the knowledge acquired by practicing and academic Quantity Surveyors. This finding conveys the importance of sustainability knowledge and how it is fundamental in achieving the UN sustainable goals and using such knowledge in practice

Psychiatrists should investigate their patients less

Psychiatrists often order investigations such as blood tests, neuroimaging and electroencephalograms for their patients. Rationales include ruling out 'organic' causes of psychiatric presentations, providing baseline parameters before starting psychotropic medications, and screening for general cardiometabolic health. Hospital protocols often recommend an extensive panel of blood tests on admission to a psychiatric ward. In this Against the Stream article, we argue that many of these investigations are at best useless and at worst harmful: the yield of positive findings that change clinical management is extremely low; special investigations are a poor substitute for a targeted history and examination; and incidental findings may cause anxiety and further unwarranted investigation. Cognitive and cultural reasons why over-investigation continues are discussed. We conclude by encouraging a more targeted approach guided by a thorough bedside clinical assessment

Reflection factorizations of Singer cycles

Abstract. The number of shortest factorizations into reflections for a Singer cycle inGLn(Fq) is shown to be (q n − 1) n−1. Formulas counting factorizations of any length, and counting those with reflections of fixed conjugacy classes are also given. Résumé. Nous prouvons que le nombre de factorisations de longueur minimale d’un cycle de Singer dans GLn(Fq) comme un produit de réflexions est (q n −1) n−1. Nous présentons aussi des formules donnant le nombre de factorisations de toutes les longueurs ainsi que des formules pour le nombre de factorisations comme produit de réflexions ayant des classes de conjugaison fixes

Resonance-like piezoelectric electron-phonon interaction in layered structures

We show that mismatch of the piezoelectric parameters between layers of multiple-quantum well structures leads to modification of the electron-phonon interaction. In particular, short-wavelength phonons propagating perpendicular to the layers with wavevector close to $2\pi n/d$, where $d$ is the period of the structure, induce a strong smoothly-varying component of the piezo-potential. As a result, they interact efficiently with 2D electrons. It is shown, that this property leads to emission of collimated quasi-monochromatic beams of high-frequency acoustic phonons from hot electrons in multiple-quantum well structures. We argue that this effect is responsible for the recently reported monochromatic transverse phonon emission from optically excited GaAs/AlAs superlattices, and provide additional experimental evidences of this.Comment: 6 pages, 7 figure

Neurological Examination

Wilfred Trotter has said that the performance of a refined neurological examination is “ a job for men” . Certainly performing a full neurological examination seems to separate the men from the boys and many medical students are often unnecessarily alarmed at the prospect. Much of this anxiety can be dispelled, however, if the logic of the examination is appreciated. A greater number of objective signs can be elicited in the examination of the nervous system than in any other system and this profusion of signs, at first so unnerving, can be a positive advantage in providing sufficiently precise information regarding the site of dysfunction in the nervous system. After the examination has revealed this anatomical diagnosis, the physician, by taking into account the details of the evolution of the disease revealed in the history, can usually reach a final conclusion regarding the nature of the disease which is causing the dysfunction in the nervous system. This is the final or pathological diagnosis

Catatonia with GABAA receptor antibodies

A 22-year-old African woman developed acute behavioural change, against a background of sickle cell disease with strokes requiring a ventriculoperitoneal shunt. She alternated between mutism with prolonged staring and posturing, and a state of agitation with elation and echolalia. Cerebrospinal fluid (CSF) protein was elevated and electroencephalogram showed mild slowing with bitemporal slow and sharp waves. We suspected catatonia secondary to possible autoimmune encephalitis but her condition persisted despite intravenous methylprednisolone. After identifying a positive serum anti-gamma-aminobutyric acid-A (GABAA) antibody, treatment with intravenous immunoglobulin, oral corticosteroids and rituximab led to gradual improvement. Patients with catatonia may show reduced GABAA receptor density and there are two other reports of catatonia with anti-GABAA antibodies. This patient's treatment response supports the antibody's causative role

In search of consensus on aphasia management.

Morag Bixley and colleagues discuss their analysis of current UK aphasia practice

Proteoglycan degradation by the ADAMTS family of proteinases

AbstractProteoglycans are key components of extracellular matrices, providing structural support as well as influencing cellular behaviour in physiological and pathological processes. The diversity of proteoglycan function reported in the literature is equally matched by diversity in proteoglycan structure. Members of the ADAMTS (A Disintegrin And Metalloproteinase with ThromboSpondin motifs) family of enzymes degrade proteoglycans and thereby have the potential to alter tissue architecture and regulate cellular function. In this review, we focus on ADAMTS enzymes that degrade the lectican and small leucine-rich repeat families of proteoglycans. We discuss the known ADAMTS cleavage sites and the consequences of cleavage at these sites. We illustrate our discussion with examples from the literature in which ADAMTS proteolysis of proteoglycans makes profound changes to tissue function

How anthocyanin mutants respond to stress: the need to distinguish between stress tolerance and maximal vigour

Background: Anthocyanins are produced by plants in response to diverse stresses. Mutants that block the anthocyanin biosynthetic pathway (ABP) at various steps can easily be compared across numerous abiotic stresses. Hypothesis: Anthocyanins or their precursors are required for stress tolerance. Thus, ABP loss-of-function mutants should have proportionately lower fitness than wildtype plants under stress, compared with benign conditions. In contrast, a decrease in maximal vigour - the general capacity for growth and fecundity - should be most pronounced under benign conditions that allow luxuriant growth by the most vigorous genotypes. Tests: Determine whether, under stressful conditions, ABP loss-of-function mutants have relatively lower fitness than wildtype plants. Also, test for reduced maximal vigour by determining whether ABP mutants have comparatively decreased fitness under optimal (\u27benign\u27) growing conditions. Organism: Arabidopsis thaliana loss-of-function mutants (representing all steps in the ABP), as well as wildtype plants, in two genetic backgrounds. Methods: We grew plants under near-optimal conditions and five stress treatments (UV-B, drought, cold, low Ca:Mg, high Ni). We estimated relative fitness as an individual\u27s lifetime fertility, relative to the mean wildtype fertility in a given treatment. Results: Stress treatments significantly reduced lifetime fertility of wildtype and mutant lines. Wildtypes outperformed anthocyanin-deficient mutants under benign conditions, but as the stress increased, the difference between wildtype and mutant fitness diminished. Fitness did not increase with a mutation\u27s sequential position in the ABP, nor was there an effect of the ability to produce flavonols on fertility. Conclusions: Mutations in the ABP did not reduce stress tolerance. Rather, the loss of ABP function reduced maximal vigour, most evidently in near-optimal growth conditions. © 2010 Eric J. von Wettberg