1,630 research outputs found
High temperature arrest of inflorescence development in broccoli (Brassica oleracea var. italica L.)
High temperature causes unevenly-sized flower buds on broccoli inflorescences. This deformity limits production of broccoli to areas where summer temperatures rarely exceed 30 °C. The stage of development sensitive to heat was determined by exposing plants of ‘Galaxy' broccoli at varying developmental stages to 35 °C day temperature for 1 week, and subsequently analysing the head structure. During the high temperature exposure, the development of certain flower buds was arrested. There was no corresponding cessation of bud initiation at the apex. No injury resulted if heat was applied before the reproductive induction, nor was there injury to differentiated flower buds. Meristems were affected only if heat was applied during inflorescence production or the floral initiation process. Shorter heat exposures produced little injury, and longer exposures were lethal. The plant's development at this sensitive period still appeared vegetative externally, but the youngest leaves had just begun to reorientate as a consequence of the reduced stem elongation rate. The meristem was less than 1 mm wide, and floral primordia were just forming, still subtended by leaf primordia. The injury was fully expressed by the time the head was first exposed (approximately 5-10 mm wide), though it became more apparent as the head matured. The buds that were delayed in development by the high temperature developed into normal flower
Stromal upregulation of lateral epithelial adhesions: gene expression analysis of signalling pathways in prostate epithelium
Background: Stromal signalling increases the lateral cell adhesions of prostate epithelial cells grown in 3D culture. The aim of this study was to use microarray analysis to identify significant epithelial signalling pathways and genes in this process. Methods: Microarray analysis was used to identify genes that were differentially expressed when epithelial cells were grown in 3D Matrigel culture with stromal co-culture compared to without stroma. Two culture models were employed: primary epithelial cells (ten samples) and an epithelial cell line (three experiments). A separate microarray analysis was performed on each model system and then compared to identify tissue-relevant genes in a cell line model. Results: TGF beta signalling was significantly ranked for both model systems and in both models the TGF beta signalling gene SOX4 was significantly down regulated. Analysis of all differentially expressed genes to identify genes that were common to both models found several morphology related gene clusters; actin binding (DIAPH2, FHOD3, ABLIM1, TMOD4, MYH10), GTPase activator activity (BCR, MYH10), cytoskeleton (MAP2, MYH10, TMOD4, FHOD3), protein binding (ITGA6, CD44), proteinaceous extracellular matrix (NID2, CILP2), ion channel/ion transporter activity (CACNA1C, CACNB2, KCNH2, SLC8A1, SLC39A9) and genes associated with developmental pathways (POFUT1, FZD2, HOXA5, IRX2, FGF11, SOX4, SMARCC1). Conclusions: In 3D prostate cultures, stromal cells increase lateral epithelial cell adhesions. We show that this morphological effect is associated with gene expression changes to TGF beta signalling, cytoskeleton and anion activity
Are parental concerns for child TV viewing associated with child TV viewing and the home sedentary environment?
BackgroundTime spent watching television affects multiple aspects of child and adolescent health. Although a diverse range of factors have been found to be associated with young people\u27s television viewing, parents and the home environment are particularly influential. However, little is known about whether parents, particularly those who are concerned about their child\u27s television viewing habits, translate their concern into action by providing supportive home environments (e.g. rules restricting screen-time behaviours, limited access to screen-based media). The aim of this study was to examine associations between parental concerns for child television viewing and child television viewing and the home sedentary environment.MethodsParents of children aged 5-6 years (\u27younger\u27 children, n = 430) and 10-12 years (\u27older children\u27, n = 640) reported usual duration of their child\u27s television (TV) viewing, their concerns regarding the amount of time their child spends watching TV, and on aspects of the home environment. Regression analyses examined associations between parental concern and child TV viewing, and between parental concern and aspects of the home environment. Analyses were stratified by age group.ResultsChildren of concerned parents watched more TV than those whose parents were not concerned (B = 9.63, 95% CI = 1.58-17.68, p = 0.02 and B = 15.82, 95% CI = 8.85-22.80, p < 0.01, for younger and older children respectively). Parental concern was positively associated with younger children eating dinner in front of the television, and with parental restriction of sedentary behaviours and offering sedentary activities (i.e. TV viewing or computer use) as a reward for good behaviour among older and young children. Furthermore, parents of older children who were concerned had fewer televisions in the home and a lower count of sedentary equipment in the home.ConclusionsChildren of concerned parents watched more TV than those whose parents who were not concerned. Parents appear to recognise excessive television viewing in their children and these parents appear to engage in conflicting parental approaches despite these concerns. Interventions targeting concerned parents may be an innovative way of reaching children most in need of strategies to reduce their television viewing and harnessing this parental concern may offer considerable opportunity to change the family and home environment.<br /
Using digital data and bibliometric analysis for researching doctoral education
As more digital data become publicly available new opportunities for researchers in education are arising. Researchers may be unaware of the existence and usefulness of such data even though these are freely available. In this article the use of one such source of information is described and its potential for research into research education discussed. We sought to exploit the research potential of the existing, yet dispersed, collection of online Australian thesis records to inform their research into the development of the PhD in Australia. Having created a searchable and reliable database from the available records, bibliometric analyses enabled us to map knowledge production and research capability in institutional and disciplinary settings from 1949 to 2003 as indicated by PhD theses. This is in contrast to the more familiar use of data based on student load or completion rates, and complements that data by focusing on research output as opposed to student throughput.<br /
Indels, structural variation, and recombination drive genomic diversity inPlasmodium falciparum
The malaria parasite Plasmodium falciparum has a great capacity for evolutionary adaptation to evade host immunity and develop drug resistance. Current understanding of parasite evolution is impeded by the fact that a large fraction of the genome is either highly repetitive or highly variable and thus difficult to analyze using short-read sequencing technologies. Here, we describe a resource of deep sequencing data on parents and progeny from genetic crosses, which has enabled us to perform the first genome-wide, integrated analysis of SNP, indel and complex polymorphisms, using Mendelian error rates as an indicator of genotypic accuracy. These data reveal that indels are exceptionally abundant, being more common than SNPs and thus the dominant mode of polymorphism within the core genome. We use the high density of SNP and indel markers to analyze patterns of meiotic recombination, confirming a high rate of crossover events and providing the first estimates for the rate of non-crossover events and the length of conversion tracts. We observe several instances of meiotic recombination within copy number variants associated with drug resistance, demonstrating a mechanism whereby fitness costs associated with resistance mutations could be compensated and greater phenotypic plasticity could be acquired
The failure of suicide prevention in primary care: family and GP perspectives - a qualitative study
Background Although Primary care is crucial for suicide prevention, clinicians tend to report completed suicides in their care as non-preventable. We aimed to examine systemic inadequacies in suicide prevention from the perspectives of bereaved family members and GPs.Methods Qualitative study of 72 relatives or close friends bereaved by suicide and 19 General Practitioners who have experienced the suicide of patients.Results Relatives highlight failures in detecting symptoms and behavioral changes and the inability of GPs to understand the needs of patients and their social contexts. A perceived overreliance on anti-depressant treatment is a major source of criticism by family members. GPs tend to lack confidence in the recognition and management of suicidal patients, and report structural inadequacies in service provision.Conclusions Mental health and primary care services must find innovative and ethical ways to involve families in the decision-making process for patients at risk of suicide
HPA axis reactivity to pharmacologic and psychological stressors in euthymic women with histories of postpartum versus major depression
It is unclear whether women with a history of postpartum depression (PPD) have residual, abnormal hypothalamic-pituitary-adrenal (HPA) axis reactivity, as has been reported in major depression (MDD). Further unclear is whether the abnormalities in HPA axis reactivity associated with MDD represent a stable, underlying predisposition or a state-dependent phenomenon. This study sought the following: (1) to determine if euthymic postpartum women with a history of depression have an abnormal HPA axis reactivity to pharmacologic and psychological challenges and (2) to compare HPA reactivity in women with histories of PPD versus MDD. As a secondary objective, we wanted to determine the influence of trauma history on HPA axis function. Forty-five parous (12–24 months postpartum), euthymic women with history of MDD (n = 15), PPD (n = 15), and controls (n = 15) completed pharmacologic (dexamethasone/corticotropin-releasing hormone (CRH) test [DEX/CRH]) and psychological (Trier social stress test [TSST]) challenges during the luteal phase. Outcome measures were cortisol and adrenocorticotropic hormone (ACTH) response after DEX/CRH, and blood pressure, heart rate, epinephrine, norepinephrine, and cortisol response during the TSST. All groups had robust cortisol and ACTH response to DEX/CRH and cortisol response to TSST. Groups did not differ significantly in cortisol or ACTH response to DEX/CRH or in blood pressure, heart rate, epinephrine, norepinephrine, or cortisol response to TSST. Cortisol/ACTH ratio did not differ significantly between groups. Trauma history was associated with decreased cortisol response to DEX/CRH in women with histories of MDD, which was not significant after correction (F8,125, p = 0.02, Greenhouse-Geisser corrected p = 0.11). Currently euthymic women with histories of MDD or PPD did not demonstrate residual abnormal stress responsivity following administration of either a pharmacologic or psychological stressor
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