76 research outputs found
Oviposition Response of \u3ci\u3eCotesia plutellae\u3c/i\u3e (Hymenoptera: Braconidae) to Sterile and Normal Diamondback Moth (Lepidoptera: Plutellidae) Larvae
Augmentative release of the endoparasitoid Cotesia plutellae (Kurdjumov) to control diamondback moth, Plutella xylostella (L.), in cabbage, Brassica oleracea variety capitata (L.), would be expensive for growers if done continually during a growing season. A method for establishing released parasitoids would be very beneficial in the control of this pest. One method under consideration is to use sterile diamondback moth larvae deposited on \u27nursery\u27 collard plants as hosts for C. plutellae to allow the parasitoid to build up in numbers and spread into adjacent cabbage fields. Therefore, the ability of C. plutellae to accept and develop successfully in normal and sterile diamondback larvae was evaluated. C. plutellae does not discriminate between normal larvae and larvae from parents sterilized by gamma radiation, and both sets of larvae served as suitable hosts for the parasitoid. Parasitism, foliage consumption, and survivorship were similar for the 2 types of larvae. Adult female Fl parasitoids developed from sterile diamondback larvae were as fit as those from normal larvae. In laboratory bioassays, sterile and normal diamondback larvae traversed similar distances before pupation. Field cage assays showed less distance traversed by both types of larvae compared with the laboratory studies. Survivorship for both types of larvae was very low under field conditions. Results indicate that sterile diamondback moth larvae are acceptable hosts for C. plutellae and suggest that the nursery approach toward establishment and build up of numbers would be a viable approach to in-field production of the parasitoid with little chance for harm to nearby cabbage because of spread of sterile larvae from the nursery plants. This approach could be a cost effective way to augment naturally occurring parasitoids and predators in diamondback moth management programs
Increased function of pronociceptive TRPV1 at the level of the joint in a rat model of osteoarthritis pain
Objectives Blockade of transient receptor potential vanilloid 1 (TRPV1) with systemic antagonists attenuates osteoarthritis (OA) pain behaviour in rat models, but on-target-mediated hyperthermia has halted clinical trials. The present study investigated the potential for targeting TRPV1 receptors within the OA joint in order to produce analgesia.
Methods The presence of TRPV1 receptors in human synovium was detected using western blotting and immunohistochemistry. In a rat model of OA, joint levels of an endogenous ligand for TRPV1, 12- ydroxyeicosatetraenoic acid (12-HETE), were quantified using liquid chromatography-tandem mass spectrometry (LCMS/MS). Effects of peripheral administration of the TRPV1 receptor antagonist JNJ-17203212 on afferent fibre activity, pain behaviour and core body temperature were investigated. Effects of a spinal administration of JNJ-17203212 on dorsal horn neuronal responses were studied.
Results We demonstrate increased TRPV1 immunoreactivity in human OA synovium, confirming the diseased joint as a potential therapeutic target for TRPV1-mediated analgesia. In a model of OA pain, we report increased joint levels of 12-HETE, and the sensitisation of joint afferent neurones to mechanical
stimulation of the knee. Local administration of JNJ- 17203212 reversed this sensitisation of joint afferents
and inhibited pain behaviour (weight-bearing asymmetry), to a comparable extent as systemic JNJ-
17203212, in this model of OA pain, but did not alter core body temperature. There was no evidence for
increased TRPV1 function in the spinal cord in this model of OA pain.
Conclusions Our data provide a clinical and mechanistic rationale for the future investigation of the therapeutic benefits of intra-articular administration of TRPV1 antagonists for the treatment of OA pain
Railway bridge structural health monitoring and fault detection: state-of-the-art methods and future challenges
Railway importance in the transportation industry is increasing continuously, due to the growing demand of both passenger travel and transportation of goods. However, more than 35% of the 300,000 railway bridges across Europe are over 100-years old, and their reliability directly impacts the reliability of the railway network. This increased demand may lead to higher risk associated with their unexpected failures, resulting safety hazards to passengers and increased whole life cycle cost of the asset. Consequently, one of the most important aspects of evaluation of the reliability of the overall railway transport system is bridge structural health monitoring, which can monitor the health state of the bridge by allowing an early detection of failures. Therefore, a fast, safe and cost-effective recovery of the optimal health state of the bridge, where the levels of element degradation or failure are maintained efficiently, can be achieved. In this article, after an introduction to the desired features of structural health monitoring, a review of the most commonly adopted bridge fault detection methods is presented. Mainly, the analysis focuses on model-based finite element updating strategies, non-model-based (data-driven) fault detection methods, such as artificial neural network, and Bayesian belief network–based structural health monitoring methods. A comparative study, which aims to discuss and compare the performance of the reviewed types of structural health monitoring methods, is then presented by analysing a short-span steel structure of a railway bridge. Opportunities and future challenges of the fault detection methods of railway bridges are highlighted
Correlations between milk and plasma levels of amino and carboxylic acids in dairy cows.
The objective of this study was to investigate the relationship between the concentrations of 19 amino acids, glucose, and seven carboxylic acids in the blood and milk of dairy cows and their correlations with established markers of ketosis. To that end, blood plasma and milk specimens were collected throughout lactation in two breeds of dairy cows of different milk yield. Plasma concentrations of glucose, pyruvate, lactate, α-aminobutyrate, β-hydroxybutyrate (BHBA), and most amino acids, except for glutamate and aspartate, were on average 9.9-fold higher than their respective milk levels. In contrast, glutamate, aspartate, and the Krebs cycle intermediates succinate, fumarate, malate, and citrate were on average 9.1-fold higher in milk than in plasma. For most metabolites, with the exception of BHBA and threonine, no significant correlations were observed between their levels in plasma and milk. Additionally, milk levels of acetone showed significant direct relationships with the glycine-to-alanine ratio and the BHBA concentration in plasma. The marked decline in plasma concentrations of glucose, pyruvate, lactate, and alanine in cows with plasma BHBA levels above the diagnostic cutoff point for subclinical ketosis suggests that these animals fail to meet their glucose demand and, as a consequence, rely increasingly on ketone bodies as a source of energy. The concomitant increase in plasma glycine may reflect not only the excessive depletion of protein reserves but also a potential deficiency of vitamin B6
Invited review: Large-scale indirect measurements for enteric methane emissions in dairy cattle: A review of proxies and their potential for use in management and breeding decisions
Publication history: Accepted - 7 December 2016; Published online - 1 February 2017.Efforts to reduce the carbon footprint of milk production through selection and management of low-emitting
cows require accurate and large-scale measurements of
methane (CH4) emissions from individual cows. Several
techniques have been developed to measure CH4 in a research setting but most are not suitable for large-scale
recording on farm. Several groups have explored proxies (i.e., indicators or indirect traits) for CH4; ideally
these should be accurate, inexpensive, and amenable
to being recorded individually on a large scale. This
review (1) systematically describes the biological basis
of current potential CH4 proxies for dairy cattle; (2)
assesses the accuracy and predictive power of single
proxies and determines the added value of combining
proxies; (3) provides a critical evaluation of the relative
merit of the main proxies in terms of their simplicity,
cost, accuracy, invasiveness, and throughput; and (4)
discusses their suitability as selection traits. The proxies range from simple and low-cost measurements such
as body weight and high-throughput milk mid-infrared
spectroscopy (MIR) to more challenging measures such
as rumen morphology, rumen metabolites, or microbiome profiling. Proxies based on rumen samples are generally poor to moderately accurate predictors of CH4,
and are costly and difficult to measure routinely onfarm. Proxies related to body weight or milk yield and
composition, on the other hand, are relatively simple,
inexpensive, and high throughput, and are easier to
implement in practice. In particular, milk MIR, along
with covariates such as lactation stage, are a promising
option for prediction of CH4 emission in dairy cows.
No single proxy was found to accurately predict CH4,
and combinations of 2 or more proxies are likely to be
a better solution. Combining proxies can increase the
accuracy of predictions by 15 to 35%, mainly because
different proxies describe independent sources of variation in CH4 and one proxy can correct for shortcomings
in the other(s). The most important applications of
CH4 proxies are in dairy cattle management and breeding for lower environmental impact. When breeding for
traits of lower environmental impact, single or multiple
proxies can be used as indirect criteria for the breeding
objective, but care should be taken to avoid unfavorable correlated responses. Finally, although combinations of proxies appear to provide the most accurate
estimates of CH4, the greatest limitation today is the
lack of robustness in their general applicability. Future
efforts should therefore be directed toward developing
combinations of proxies that are robust and applicable
across diverse production systems and environments.Technical and financial support from the COST Action FA1302 of the European Union
Mature adipocytes may be a source of stem cells for tissue engineering
Adipose tissue contains a large portion of stem cells. These cells appear morphologically like fibroblasts and are primarily derived from the stromal cell fraction. Mature (lipid-filled) adipocytes possess the ability to become proliferative cells and have been shown to produce progeny cells that possess the same morphological (fibroblast-like) appearance as the stem cells from the stromal fraction. A closer examination of mature adipocyte-derived progeny cells may prove to be an emerging area of growth/metabolic physiology that may modify present thinking about adipose tissue renewal capabilities. Knowledge of these cells may also prove beneficial in cell-based therapies for tissue repair, regeneration, or engineering
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