The influence of rearing density on the subsequent response to ddt dosing for tadpoles of the frogRana temporaria

1979 ◽  
Vol 21 (1) ◽  
pp. 837-841 ◽  
Author(s):  
A. S. Cooke
1970 ◽  
Vol 65 (4) ◽  
pp. 608-616 ◽  
Author(s):  
M. J. Levell ◽  
S. R. Stitch ◽  
M. J. Noronha

ABSTRACT Pituitary-adrenal function was tested in a group of 33 patients with multiple sclerosis who had been treated with corticotrophin for at least 1 year. Assessment was made by measuring the change in the plasma 11-hydroxycorticosteroid concentration following lysine vasopressin (LVP) administration. Ten patients showed abnormally small increases after LVP. Two of the 5 patients with the smallest increases still showed impairment 8 months later. The patients with no withdrawal symptoms had normal or nearly normal increases following LVP. There was an association between the concentration of 11-hydroxycorticosteroids immediately after withdrawal of ACTH and the subsequent response to LVP.


2021 ◽  
Vol 13 ◽  
pp. 1759720X2110140
Author(s):  
Conor Magee ◽  
Hannah Jethwa ◽  
Oliver M. FitzGerald ◽  
Deepak R. Jadon

Aims: The ability to predict response to treatment remains a key unmet need in psoriatic disease. We conducted a systematic review of studies relating to biomarkers associated with response to treatment in either psoriasis vulgaris (PsV) or psoriatic arthritis (PsA). Methods: A search was conducted in PubMed, Embase and the Cochrane library from their inception to 2 September 2020, and conference proceedings from four major rheumatology conferences. Original research articles studying pre-treatment biomarker levels associated with subsequent response to pharmacologic treatment in either PsV or PsA were included. Results: A total of 765 articles were retrieved and after review, 44 articles (22 relating to PsV and 22 to PsA) met the systematic review’s eligibility criteria. One study examined the response to methotrexate, one the response to tofacitinib and all the other studies to biologic disease-modifying antirheumatic drugs (DMARDs). Whilst several studies examined the HLA-C*06 allele in PsV, the results were conflicting. Interleukin (IL)-12 serum levels and polymorphisms in the IL-12B gene show promise as biomarkers of treatment response in PsV. Most, but not all, studies found that higher baseline levels of C-reactive protein (CRP) were associated with a better clinical response to treatment in patients with PsA. Conclusion: Several studies have identified biomarkers associated with subsequent response to treatment in psoriatic disease. However, due to the different types of biomarkers, treatments and outcome measures used, firm conclusions cannot be drawn. Further validation is needed before any of these biomarkers translate to clinical practice.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nwamaka Oluchukwu Akpodiete ◽  
Frédéric Tripet

Abstract Background Malaria vector control approaches that rely on mosquito releases such as the sterile insect technique (SIT) and suppression or replacement strategies relying on genetically modified mosquitoes (GMM) depend on effective mass production of Anopheles mosquitoes. Anophelines typically require relatively clean larval rearing water, and water management techniques that minimise toxic ammonia are key to achieving optimal rearing conditions in small and large rearing facilities. Zeolites are extensively used in closed-system fish aquaculture to improve water quality and reduce water consumption, thanks to their selective adsorption of ammonia and toxic heavy metals. The many advantages of zeolites include low cost, abundance in many parts of the world and environmental friendliness. However, so far, their potential benefit for mosquito rearing has not been evaluated. Methods This study evaluated the independent effects of zeolite and daily water changes (to simulate a continuous flow system) on the rearing of An. coluzzii under two feed regimes (powder and slurry feed) and larval densities (200 and 400 larvae per tray). The duration of larval development, adult emergence success and phenotypic quality (body size) were recorded to assess the impact of water treatments on mosquito numbers, phenotypic quality and identification of optimal feeding regimes and larval density for the use of zeolite. Results Overall, mosquito emergence, duration of development and adult phenotypic quality were significantly better in treatments with daily water changes. In treatments without daily water changes, zeolite significantly improved water quality at the lower larval rearing density, resulting in higher mosquito emergence and shorter development time. At the lower larval rearing density, the adult phenotypic quality did not significantly differ between zeolite treatment without water changes and those with daily changes. Conclusions These results suggest that treating rearing water with zeolite can improve mosquito production in smaller facilities. Zeolite could also offer cost-effective and environmentally friendly solutions for water recycling management systems in larger production facilities. Further studies are needed to optimise and assess the costs and benefits of such applications to Anopheles gambiae (s.l.) mosquito-rearing programmes. Graphic abstract


2002 ◽  
Vol 14 (3) ◽  
pp. 261-292 ◽  
Author(s):  
J. Michael Martinez

In the wake of India's May 1998 decision to resume nuclear testing for the first time since 1974, as well as arch-rival Pakistan's subsequent response, the attention of the world again has focused on nuclear nonproliferation policy as a means of maintaining stability in politically troubled regions of the world. The 1990s proved to be an uncertain time for nonproliferation policy. Pakistan acquired nuclear capabilities. Iraq displayed its well-known intransigence by refusing to allow International Atomic Energy Agency (IAEA) arms inspectors access to facilities suspected of manufacturing nuclear weapons. North Korea maintained a nuclear weapons program despite opposition from many Western nations. Troubling questions about nuclear holdings persisted in Argentina, Brazil, and South Africa. New nuclear powers were created in Belarus, Kazakhstan, Russia, and Ukraine after the disintegration of the Soviet Union. Even the renewal of the Treaty on the Non-Proliferation of Nuclear Weapons in 1995 failed to assuage the concerns of Western powers fearful of aggressive measures undertaken by rogue nuclear proliferants.


Author(s):  
Sarah Tremblay-Bourgeois ◽  
Nathalie R Le François ◽  
Robert L Roy ◽  
Tillmann J Benfey ◽  
Albert K Imsland

Author(s):  
Robert H. Brown ◽  
David W. Kaczka ◽  
Katherine Fallano ◽  
Steve Shapiro ◽  
Wayne Mitzner

In healthy individuals, a DI can reverse (bronchodilation) or prevent (bronchoprotection) induced airway constriction. For individuals with asthma or COPD, these effects may be attenuated or absent. Previous work showed that the size and duration of a DI affected the subsequent response of the airways. Also, increased airway tone lead to increased airway size variability. The present study examined how a DI affected the temporal variability in individual airway baseline size and after methacholine challenge in dogs using High-Resolution Computed Tomography. Dogs were anesthetized and ventilated, and on 4 separate days, HRCT scans were acquired before and after a DI at baseline and during a continuous intravenous infusion of methacholine (Mch) at 3 dose rates (17, 67, and 200 μg/mm). The Coefficient of Variation was used as an index of temporal variability in airway size. We found that at baseline and the lowest dose of Mch, variability decreased immediately and 5 minutes after the DI ( P < 0.0001). In contrast, with higher doses of Mch, the DI caused a variable response. At a rate of 67 μg/min of Mch, the temporal variability increased after 5 minutes, while at a rate of 200 μg/min of Mch, the temporal variability increased immediately after the DI. Increased airway temporal variability has been shown to be associated with asthma. Although the mechanisms underlying this temporal variability are poorly understood, the beneficial effects of a DI to decrease airway temporal variability was eliminated when airway tone was increased. If this effect is absent in asthmatics, this may suggest a possible mechanism for the loss of bronchoprotective and bronchodilatory effects after a DI in asthma.


2015 ◽  
Vol 11 (3) ◽  
pp. 20150012 ◽  
Author(s):  
Kenneth Wilson ◽  
Robert I. Graham

There is an increasing appreciation of the importance of transgenerational effects on offspring fitness, including in relation to immune function and disease resistance. Here, we assess the impact of parental rearing density on offspring resistance to viral challenge in an insect species expressing density-dependent prophylaxis (DDP); i.e. the adaptive increase in resistance or tolerance to pathogen infection in response to crowding. We quantified survival rates in larvae of the cotton leafworm ( Spodoptera littoralis ) from either gregarious- or solitary-reared parents following challenge with the baculovirus S. littoralis nucleopolyhedrovirus. Larvae from both the parental and offspring generations exhibited DDP, with gregarious-reared larvae having higher survival rates post-challenge than solitary-reared larvae. Within each of these categories, however, survival following infection was lower in those larvae from gregarious-reared parents than those from solitary-reared, consistent with a transgenerational cost of DDP immune upregulation. This observation demonstrates that crowding influences lepidopteran disease resistance over multiple generations, with potential implications for the dynamics of host–pathogen interactions.


1992 ◽  
Vol 68 (5) ◽  
pp. 1667-1682 ◽  
Author(s):  
P. J. Simmons ◽  
F. C. Rind

1. We examine the critical image cues that are used by the locust visual system for the descending contralateral motion detector (DCMD) neuron to distinguish approaching from receding objects. Images were controlled by computer and presented on an electrostatic monitor. 2. Changes in overall luminance elicited much smaller and briefer responses from the DCMD than objects that appeared to approach the eye. Although a decrease in overall luminance might boost the response to an approaching dark object, movement of edges of the image is more important. 3. When two pairs of lines, in a cross-hairs configuration, were moved apart and then together again, the DCMD showed no preference for divergence compared with convergence of edges. A directional response was obtained by either making the lines increase in extent during divergence and decrease in extent during convergence; or by continually increasing the velocity of line movement during divergence and decreasing velocity during convergence. 4. The DCMD consistently gave a larger response to growing than to shrinking solid rectangular images. An increase compared with a decrease in the extent of edge in an image is, therefore, an important cue for the directionality of the response. For single moving edges of fixed extent, the neuron gave the largest response to edges that subtended 15 degrees at the eye. 5. The DCMD was very sensitive to the amount by which an edge traveled between frames on the display screen, with the largest responses generated by 2.5 degrees of travel. This implies that the neurons in the optic lobe that drive this movement-detecting system have receptive fields of about the same extent as a single ommatidium. 6. For edges moving up to 250 degree/s, the excitation of the DCMD increases with velocity. The response to an edge moving at a constant velocity adapts rapidly, in a manner that depends on velocity. Movement over one part of the retina can adapt the subsequent response to movement over another part of the retina. 7. For the DCMD to track and continue to respond to the image of an approaching object, the edges of the image must continually increase in velocity. This is the second important stimulus cue. 8. Edges of opposite contrasts (light-dark compared with dark-light) are processed in separate pathways that inhibit each other. This would contribute to the reduction of responses to wide-field movements.


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