187 research outputs found

    Developmental biology and prey preference of Diomus notescens Blackburn (Coleoptera: Coccinellidae): A predator of Aphis gossypii Glover (Hemiptera: Aphididae)

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    The minute two-spotted ladybeetle, Diomus notescens Blackburn is a common predator of aphids and other pests in Australian agricultural crops, however little is known about the biology of D. notescens. The aim of this study was to provide information on the life cycle of this predator and improve our understanding of its biological control potential, particularly against one of the major pests of cotton, Aphis gossypii Glover. In laboratory experiments, juvenile development, prey consumption, as well as adult lifespan and fecundity were studied. Results from this study revealed that D. notescens could successfully complete development on A. gossypii, which at 25 °C required 21 days and during this period they each consume 129 ± 5.2 aphids. At 25 °C adult lifespan was 77 ± 9.6 days, with a mean daily prey consumption of 28 ± 1.8 aphids and a mean daily fecundity of 8 ± 0.5 eggs. Net reproductive rate was estimated as 187 ± 25.1 females and the intrinsic rate of increase was estimated as 0.14. Juvenile development was recorded at four constant temperatures (15, 21, 26 and 27 °C) and using a linear model, the lower threshold for D. notescens development was estimated to be 10 ± 0.6 °C with 285 ± 4.7 degree days required to complete development. A prey choice experiment studying predation rates revealed a strong preference for A. gossypii nymphs compared to Bemisia tabaci Gennadius eggs

    Identification of a Novel Synaptic Protein, TMTC3, Involved in Periventricular Nodular Heterotopia with Intellectual Disability and Epilepsy

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    Defects in neuronal migration cause brain malformations, which are associated with intellectual disability (ID) and epilepsy. Using exome sequencing, we identified compound heterozygous variants (p.Arg71His and p. Leu729ThrfsTer6) in TMTC3, encoding transmembrane and tetratricopeptide repeat containing 3, in four siblings with nocturnal seizures and ID. Three of the four siblings have periventricular nodular heterotopia (PVNH), a common brain malformation caused by failure of neurons to migrate from the ventricular zone to the cortex. Expression analysis using patient-derived cells confirmed reduced TMTC3 transcript levels and loss of the TMTC3 protein compared to parental and control cells. As TMTC3 function is currently unexplored in the brain, we gathered support for a neurobiological role for TMTC3 by generating flies with post-mitotic neuron-specific knockdown of the highly conserved Drosophila melanogaster TMTC3 ortholog, CG4050/tmtc3. Neuron-specific knockdown of tmtc3 in flies resulted in increased susceptibility to induced seizures. Importantly, this phenotype was rescued by neuron-specific expression of human TMTC3, suggesting a role for TMTC3 in seizure biology. In addition, we observed co-localization of TMTC3 in the rat brain with vesicular GABA transporter (VGAT), a presynaptic marker for inhibitory synapses. TMTC3 is localized at VGAT positive pre-synaptic terminals and boutons in the rat hypothalamus and piriform cortex, suggesting a role for TMTC3 in the regulation of GABAergic inhibitory synapses. TMTC3 did not co-localize with Vglut2, a presynaptic marker for excitatory neurons. Our data identified TMTC3 as a synaptic protein that is involved in PVNH with ID and epilepsy, in addition to its previously described association with cobblestone lissencephaly

    Measuring senescence rates of patients with end-stage renal disease while accounting for population heterogeneity : an analysis of data from the ERA-EDTA Registry

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    Purpose: Although a population's senescence rate is classically measured as the increase in mortality rate with age on a logarithmic scale, it may be more accurately measured as the increase on a linear scale. Patients on dialysis, who suffer from accelerated senescence, exhibit a smaller increase in their mortality rate on a logarithmic scale, but a larger increase on a linear scale than patients with a functioning kidney transplant. However, this comparison may be biased by population heterogeneity. Methods: Follow-up data on 323,308 patients on dialysis and 91,679 patients with a functioning kidney transplant were derived from the ERA-EDTA Registry. We measured the increases in their mortality rates using Gompertz frailty models that allow individual variation in this increase. Results: According to these models, the senescence rate measured as the increase in mortality rate on a logarithmic scale was smaller in patients on dialysis, while the senescence rate measured as the increase on a linear scale was larger in patients on dialysis than patients with a functioning kidney transplant. Conclusions: Also when accounting for population heterogeneity, a population's senescence rate is more accurately measured as the increase in mortality rate on a linear scale than a logarithmic scale. (C) 2016 Elsevier Inc. All rights reserved.Peer reviewe

    Data from the ERA-EDTA Registry were examined for trends in excess mortality in European adults on kidney replacement therapy

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    The objective of this study was to investigate whether the improvement in survival seen in patients on kidney replacement therapy reflects the enhanced survival of the general population. Patient and general population statistics were obtained from the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry and the World Health Organization databases, respectively. Relative survival models were composed to examine trends over time in all-cause and cause-specific excess mortality, stratified by age and modality of kidney replacement therapy, and adjusted for sex, primary kidney disease and country. In total, 280,075 adult patients started kidney replacement therapy between 2002 and 2015. The excess mortality risk in these patients decreased by 16% per five years (relative excess mortality risk (RER) 0.84; 95% confidence interval 0.83-0.84). This reflected a 14% risk reduction in dialysis patients (RER 0.86; 0.85-0.86), and a 16% increase in kidney transplant recipients (RER 1.16; 1.07-1.26). Patients on dialysis showed a decrease in excess mortality risk of 28% per five years for atheromatous cardiovascular disease as the cause of death (RER 0.72; 0.70-0.74), 10% for non-atheromatous cardiovascular disease (RER 0.90; 0.88-0.92) and 10% for infections (RER 0.90; 0.87-0.92). Kidney transplant recipients showed stable excess mortality risks for most causes of death, although it did worsen in some subgroups. Thus, the increase in survival in patients on kidney replacement therapy is not only due to enhanced survival in the general population, but also due to improved survival in the patient population, primarily in dialysis patients.Peer reviewe

    BAC-Based Sequencing of Behaviorally-Relevant Genes in the Prairie Vole

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    The prairie vole (Microtus ochrogaster) is an important model organism for the study of social behavior, yet our ability to correlate genes and behavior in this species has been limited due to a lack of genetic and genomic resources. Here we report the BAC-based targeted sequencing of behaviorally-relevant genes and flanking regions in the prairie vole. A total of 6.4 Mb of non-redundant or haplotype-specific sequence assemblies were generated that span the partial or complete sequence of 21 behaviorally-relevant genes as well as an additional 55 flanking genes. Estimates of nucleotide diversity from 13 loci based on alignments of 1.7 Mb of haplotype-specific assemblies revealed an average pair-wise heterozygosity (8.4×10−3). Comparative analyses of the prairie vole proteins encoded by the behaviorally-relevant genes identified >100 substitutions specific to the prairie vole lineage. Finally, our sequencing data indicate that a duplication of the prairie vole AVPR1A locus likely originated from a recent segmental duplication spanning a minimum of 105 kb. In summary, the results of our study provide the genomic resources necessary for the molecular and genetic characterization of a high-priority set of candidate genes for regulating social behavior in the prairie vole

    Race Yourselves: A Longitudinal Exploration of Self-Competition Between Past, Present, and Future Performances in a VR Exergame

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    Participating in competitive races can be a thrilling experience for athletes, involving a rush of excitement and sensations of flow, achievement, and self-fulfilment. However, for non-athletes, the prospect of competition is often a scary one which affects intrinsic motivation negatively, especially for less fit, less competitive individuals. We propose a novel method making the positive racing experience accessible to non-athletes using a high-intensity cycling VR exergame: by recording and replaying all their previous gameplay sessions simultaneously, including a projected future performance, players can race against a crowd of "ghost" avatars representing their individual fitness journey. The experience stays relevant and exciting as every race adds a new competitor. A longitudinal study over four weeks and a cross-sectional study found that the new method improves physical performance, intrinsic motivation, and flow compared to a non-competitive exergame. Additionally, the longitudinal study provides insights into the longer-term effects of VR exergames

    CDK19 is disrupted in a female patient with bilateral congenital retinal folds, microcephaly and mild mental retardation

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    Microcephaly, mental retardation and congenital retinal folds along with other systemic features have previously been reported as a separate clinical entity. The sporadic nature of the syndrome and lack of clear inheritance patterns pointed to a genetic heterogeneity. Here, we report a genetic analysis of a female patient with microcephaly, congenital bilateral falciform retinal folds, nystagmus, and mental retardation. Karyotyping revealed a de novo pericentric inversion in chromosome 6 with breakpoints in 6p12.1 and 6q21. Fluorescence in situ hybridization analysis narrowed down the region around the breakpoints, and the breakpoint at 6q21 was found to disrupt the CDK19 gene. CDK19 was found to be expressed in a diverse range of tissues including fetal eye and fetal brain. Quantitative PCR of the CDK19 transcript from Epstein–Barr virus-transformed lymphoblastoid cell lines of the patient revealed ~50% reduction in the transcript (p = 0.02), suggesting haploinsufficiency of the gene. cdk8, the closest orthologue of human CDK19 in Drosophila has been shown to play a major role in eye development. Conditional knock-down of Drosophila cdk8 in multiple dendrite (md) neurons resulted in 35% reduced dendritic branching and altered morphology of the dendritic arbour, which appeared to be due in part to a loss of small higher order branches. In addition, Cdk8 mutant md neurons showed diminished dendritic fields revealing an important role of the CDK19 orthologue in the developing nervous system of Drosophila. This is the first time the CDK19 gene, a component of the mediator co-activator complex, has been linked to a human disease
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