952 research outputs found
Recommended from our members
Land resource assessment of Northern Belize (NRI Bulletin 43, Volume 1 of 2)
The land resource assessment was undertaken from July 1989 to June 1990 by the Natural Resources Institute (NRI) of the Overseas Development Administration (ODA), assisted by Mr. A. C. S. Wright, and Dr. M. Holder of Central Farm. The main object of the survey was to produce an updated land suitability assessment of Orange Walk, Corozal, Belize and Cayo districts which had not already been surveyed by Jenkin et al. (1976) and King et al. (1989). In addition, this survey would provide a land suitability assessment for the Belize Valley based on the soil mapping of )en kin et al. Thus, together with the land resource assessments of Toledo and Stann Creek districts (King et al., 1986, 1989 respectively), a land suitability assessment for the whole of Belize is now available
Recommended from our members
Land resource assessment of Northern Belize (NRI Bulletin 43, Volume 2 of 2)
The land resource assessment was undertaken from July 1989 to June 1990 by the Natural Resources Institute (NRI) of the Overseas Development Administration (ODA), assisted by Mr. A. C. S. Wright, and Dr. M. Holder of Central Farm. The main object of the survey was to produce an updated land suitability assessment of Orange Walk, Corozal, Belize and Cayo districts which had not already been surveyed by Jenkin et al. (1976) and King et al. (1989). In addition, this survey would provide a land suitability assessment for the Belize Valley based on the soil mapping of )en kin et al. Thus, together with the land resource assessments of Toledo and Stann Creek districts (King et al., 1986, 1989 respectively), a land suitability assessment for the whole of Belize is now available
Sodium nitroprusside prevents the detrimental effects of glucose on the neurovascular unit and behaviour in zebrafish
Diabetes is associated with dysfunction of the neurovascular unit, although the mechanisms of this are incompletely understood, and currently no treatment exists to prevent these negative effects. We previously found that the NO donor sodium nitroprusside (SNP) prevents the detrimental effect of glucose on neurovascular coupling in zebrafish. We therefore sought to establish the wider effects of glucose exposure on both the neurovascular unit and on behaviour in zebrafish and the ability of SNP to prevent these.
We incubated 4 days post fertilisation (dpf) zebrafish embryos in 20mM glucose or mannitol for five days until 9dpf, with or without 0.1mM SNP co-treatment for 24h (8-9dpf), and quantified vascular nitric oxide reactivity, vascular mural cell number, expression of a klf2a reporter, glial fibrillary acidic protein (GFAP) and TRPV4, as well as spontaneous neuronal activation at 9dpf, all in the optic tectum. We also assessed the effect on light/dark preference and locomotory characteristics during free-swimming studies.
We find that glucose exposure significantly reduced nitric oxide reactivity, klf2a reporter expression, vascular mural cell number and TRPV4 expression, while significantly increasing spontaneous neuronal activation and GFAP expression (all in the optic tectum). Furthermore, when we examined larval behaviour we found glucose exposure significantly altered light/dark preference and high and low speed locomotion while in light. Co-treatment with SNP reversed all these molecular and behavioural effects of glucose exposure.
Our findings comprehensively describe the negative effects of glucose exposure on the vascular anatomy, molecular phenotype, and function of the optic tectum and on whole organism behaviour. We also show that SNP or other NO donors may represent a therapeutic strategy to ameliorate the complications of diabetes on the neurovascular unit
The fundamental cycle of concept construction underlying various theoretical frameworks
In this paper, the development of mathematical concepts over time is considered. Particular reference is given to the shifting of attention from step-by-step procedures that are performed in time, to symbolism that can be manipulated as mental entities on paper and in the mind. The development is analysed using different theoretical perspectives, including the SOLO model and various theories of concept construction to reveal a fundamental cycle underlying the building of concepts that features widely in different ways of thinking that occurs throughout mathematical learning
Use of variability in national and regional data to estimate the prevalence of lymphangioleiomyomatosis
Background: Understanding the true prevalence of lymphangioleiomyomatosis (LAM) is important in estimating disease burden and targeting specific interventions. As with all rare diseases, obtaining reliable epidemiological data is difficult and requires innovative approaches. Aim: To determine the prevalence and incidence of LAM using data from patient organizations in seven countries, and to use the extent to which the prevalence of LAM varies regionally and nationally to determine whether prevalence estimates are related to health-care provision. Methods: Numbers of women with LAM were obtained from patient groups and national databases from seven countries (nâ=â1001). Prevalence was calculated for regions within countries using female population figures from census data. Incidence estimates were calculated for the USA, UK and Switzerland. Regional variation in prevalence and changes in incidence over time were analysed using Poisson regression and linear regression. Results: Prevalence of LAM in the seven countries ranged from 3.4 to 7.8/million women with significant variation, both between countries and between states in the USA. This variation did not relate to the number of pulmonary specialists in the region nor the percentage of population with health insurance, but suggests a large number of patients remain undiagnosed. The incidence of LAM from 2004 to 2008 ranged from 0.23 to 0.31/million women/per year in the USA, UK and Switzerland. Conclusions: Using this method, we have found that the prevalence of LAM is higher than that previously recorded and that many patients with LAM are undiagnose
Induced differential forms on manifolds of functions
Differential forms on the Fr\'echet manifold F(S,M) of smooth functions on a
compact k-dimensional manifold S can be obtained in a natural way from pairs of
differential forms on M and S by the hat pairing. Special cases are the
transgression map associating (p-k)-forms on F(S,M) to p-forms on M (hat
pairing with a constant function) and the bar map associating p-forms on F(S,M)
to p-forms on M (hat pairing with a volume form). We develop a hat calculus
similar to the tilda calculus for non-linear Grassmannians.Comment: 17 page
Recommended from our members
Simple model of adsorption on external surface of carbon nanotubes: a new analytical approach basing on molecular simulation data
Nitrogen adsorption on carbon nanotubes is wide- ly studied because nitrogen adsorption isotherm measurement is a standard method applied for porosity characterization. A further reason is that carbon nanotubes are potential adsorbents for separation of nitrogen from oxygen in air. The study presented here describes the results of GCMC simulations of nitrogen (three site model) adsorption on single and multi walled closed nanotubes. The results obtained are described by a new adsorption isotherm model proposed in this study. The model can be treated as the tube analogue of the GAB isotherm taking into account the lateral adsorbate-adsorbate interactions. We show that the model describes the simulated data satisfactorily. Next this new approach is applied for a description of experimental data measured on different commercially available (and characterized using HRTEM) carbon nanotubes. We show that generally a quite good fit is observed and therefore it is suggested that the observed mechanism of adsorption in the studied materials is mainly determined by adsorption on tubes separated at large distances, so the tubes behave almost independently
A suberized exodermis is required for tomato drought tolerance.
Plant roots integrate environmental signals with development using exquisite spatiotemporal control. This is apparent in the deposition of suberin, an apoplastic diffusion barrier, which regulates flow of water, solutes and gases, and is environmentally plastic. Suberin is considered a hallmark of endodermal differentiation but is absent in the tomato endodermis. Instead, suberin is present in the exodermis, a cell type that is absent in the model organism Arabidopsis thaliana. Here we demonstrate that the suberin regulatory network has the same parts driving suberin production in the tomato exodermis and the Arabidopsis endodermis. Despite this co-option of network components, the network has undergone rewiring to drive distinct spatial expression and with distinct contributions of specific genes. Functional genetic analyses of the tomato MYB92 transcription factor and ASFT enzyme demonstrate the importance of exodermal suberin for a plant water-deficit response and that the exodermal barrier serves an equivalent function to that of the endodermis and can act in its place
Sex differences in the associations between L-arginine pathway metabolites, skeletal muscle mass and function, and their responses to resistance exercise, in old age
This work was supported by the Biotechnology and Biological Sciences Research Council (BB/J015911/1) and was registered at clinicaltrials.gov (ClinicalTrials. gov Identifier: NCT02843009). Supplementary email included with articlePeer reviewedPostprin
- âŠ