970 resultados para Absorptive Capacity (ACAP)


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Secondary xylem of fibrous cactus wood is characterized by short narrow vessel elements with both simple perforation plates and large intervessel pits, libriform septate fibers, and large rays. These are present in basal cactus taxa, as well as in many other groups of the family. In Cactoideae, the most diversified and most derived subfamily, there are remarkable variations found in the secondary xylem, with the more highly derived taxa containing the greatest water storage capacity. Unlignified parenchyma is one specialization found in the fibrous wood of cacti. We observed this tissue in the secondary xylem at the base of the sterns of several Brazilian endemic species of Arrojadoa, Melocactus, and Stephanocereus, all members of the tribe Cereeae. In Arrojadoa and Melocactus the unlignified parenchyma occurs in lines and bands amongst the axial and radial xylem elements, while in Stephanocereus it is mainly restricted to the rays and does not form bands. We address the adaptive importance of the unlignified parenchyma in the fibrous wood in tribe Cereeae and the family Cactaceae as a whole.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

One of the main consequences of habitat loss and fragmentation is the increase in patch isolation and the consequent decrease in landscape connectivity. In this context, species persistence depends on their responses to this new landscape configuration, particularly on their capacity to move through the interhabitat matrix. Here, we aimed first to determine gap-crossing probabilities related to different gap widths for two forest birds (Thamnophilus caerulescens, Thamnophilidae, and Basileuterus culicivorus, Parulidae) from the Brazilian Atlantic rainforest. These values were defined with a playback technique and then used in analyses based on graph theory to determine functional connections among forest patches. Both species were capable of crossing forest gaps between patches, and these movements were related to gap width. The probability of crossing 40 m gaps was 50% for both species. This probability falls to 10% when the gaps are 60 m (for B. culicivorus) or 80 m (for T caerulescens). Actually, birds responded to stimulation about two times more distant inside forest trials (control) than in gap-crossing trials. Models that included gap-crossing capacity improved the explanatory power of species abundance variation in comparison to strictly structural models based merely on patch area and distance measurements. These results highlighted that even very simple functional connectivity measurements related to gap-crossing capacity can improve the understanding of the effect of habitat fragmentation on bird occurrence and abundance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Hypercycles are information integration systems which are thought to overcome the information crisis of prebiotic evolution by ensuring the coexistence of several short templates. For imperfect template replication, we derive a simple expression for the maximum number of distinct templates n(m). that can coexist in a hypercycle and show that it is a decreasing function of the length L of the templates. In the case of high replication accuracy we find that the product n(m)L tends to a constant value, limiting thus the information content of the hypercycle. Template coexistence is achieved either as a stationary equilibrium (stable fixed point) or a stable periodic orbit in which the total concentration of functional templates is nonzero. For the hypercycle system studied here we find numerical evidence that the existence of an unstable fixed point is a necessary condition for the presence of periodic orbits. (C) 2008 Elsevier Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of the study was to evaluate saliva flow rate, buffer capacity, pH levels, and dental caries experience (DCE) in autistic individuals, comparing the results with a control group (CG). The study was performed on 25 noninstitutionalized autistic boys, divided in two groups. G1 composed of ten children, ages 3-8. G2 composed of 15 adolescents ages 9-13. The CG was composed of 25 healthy boys, randomly selected and also divided in two groups: CG3 composed of 14 children ages 4-8, and CG4 composed of 11 adolescents ages 9-14. Whole saliva was collected under slight suction, and pH and buffer capacity were determined using a digital pHmeter. Buffer capacity was measured by titration using 0.01 N HCl, and the flow rate expressed in ml/min, and the DCE was expressed by decayed, missing, and filled teeth (permanent dentition [DMFT] and primary dentition [dmft]). Data were plotted and submitted to nonparametric (Kruskal-Wallis) and parametric (Student`s t test) statistical tests with a significance level less than 0.05. When comparing G1 and CG3, groups did not differ in flow rate, pH levels, buffer capacity, or DMFT. Groups G2 and CG4 differ significantly in pH (p = 0.007) and pHi = 7.0 (p = 0.001), with lower scores for G2. In autistic individuals aged 3-8 and 9-13, medicated or not, there was no significant statistical difference in flow rate, pH, and buffer capacity. The comparison of DCE among autistic children and CG children with deciduous (dmft) and mixed/permanent decayed, missing, and filled teeth (DMFT) did not show statistical difference (p = 0.743). Data suggest that autistic individuals have neither a higher flow rate nor a better buffer capacity. Similar DCE was observed in both groups studied.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the scope of our ongoing researchers on antioxidant compounds, twenty four extracts and fractions obtained from Piper arboreum Aublet and Piper tuberculatum Jacq. (Piperaceae) were screened for radical scavenging capacity (RSC) by using DPPH colorimetric assay. The strongest activity was found in ethyl acetate fractions from the leaves of P. arboreum IC(50) = 5.70 mu g/mL) and P. tuberculatum IC(50) = 8.40 mu g/mL). Hydromethanol fractions of the leaves of P. tuberculatum and P. arboreum showed moderate RSC, with values of IC(50) (mu g/mL) of 11.9 and 19.2, respectively. Additionally, a brief phytochemical study of the ethyl acetate fraction of P. arboreum leaves affording quercetin (1) and quercitrin (2), two flavonols with antioxidant activity previously described in the literature.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The leaves and twigs of Piper krukoffii, collected in the Carajas National Forest, north Brazil, yielded essential oils (2.0% and 0.8%), the main constituents of which were myristicin (40.3% and 26.7%), apiole (25.4% and 34.1%) and elemicin (2.8% and 3.0%). The antioxidant activities of the oils, methanol extract and its sub-fractions were evaluated. The DPPH EC(50) values varied from the ethyl acetate sub-fraction (73.4 +/- 3.7 mu g/mL) to the methanol extract (24.9 +/- 0.8 mu g/mL), and the ABTS TEAC values ranged in the same order from 265.7 to 349.2 mu Mol TE/g. These results indicated a significant antioxidant activity for the plant. The lignans (-)-kusunokin, yatein, (-)-hinokin and cubebin were identified in the methanol extract. The hydro-methanolic sub-fraction showed a high value for total phenol content (106.5 +/- 0.7 mg GAE/g), as well as (1)H NMR signals for sugar moieties. Crude extracts and sub-fractions were also able to inhibit beta-carotene bleaching, varying from 22.4 to 47.1%. The oils from the leaves and twigs showed strong larvicidal (21.4 and 3.6 mu g/mL) and fungicide (0.5 and 0.1 mu g/mL) activities.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Sugarcane spirit extracts of six different Brazilian woods for potential use in manufacturing aging casks were compared with similar extracts of five oak samples from different geographic origin and heat treatment regarding: (1) content of phenolics and copper; (2) radical reducing capacity and reactivity toward 2,2-diphenyl-1-picrylhydrazyl radical (DPPH center dot); and (3) effect on the rate of oxygen depletion rate in a peroxidating lipid model system. Total phenolic contents of the Brazilian wood extracts ranged from 0.65 (canela-sassafras) to 6.4 (jatoba) mmol(GAE) L(-1) and from 1.39 to 2.87 mmol(GAE) L(-1) for oak extracts. Flavonoids ranged from 1.54 x 10(-4) (ipe) to 6.5 x 10(-2) (oak) mmol(rutin) L(-1), and tannins from below the detection limit to 0.22 (jatoba) mmol(tannic acid) L(-1). Correlation was observed for the antioxidant capacity versus phenolics/flavonoids/tannins content, where oak extracts exhibit the highest radical scavenging capacity compared to Brazilian woods. Rate constant for radical scavenging by the extracts ranged from 4.9 x 10(3) M(-1) s(-1)(canela-sassafras) to 9.7 x 10(4) M(-1) s(-1) (oak). The oxygen consumption index showed the Brazilian woods amendoim and jatoba to be more efficient inhibitors than the oak extracts for lipid autoxidation initiated by metmyoglobin, despite that the oak extracts seem to be more efficient to scavenge DPPH center dot. No simple correlation with phenolics or copper content could be established, and a prooxidative tendency was observed for the extracts of canela-sassafras, castanheira, and louro-canela.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The CRAC assay is a direct electron transfer test of antioxidant capacity for several organic compounds. The ability of eight different compounds in reducing Cc 41 was studied by chronoamperometric measurements of the remaining Ce(3+) species. The following antioxidant classification was observed: tannic acid >> quercetin > rutin > gallic acid approximate to catechin > ascorbic acid > BHA > Trolox. These results agree with others already published and a good correlation (R(2) = 0.937) was found with the classical spectrophotometric FRAP assay. The CRAC assay is simple, fast, free from sample pretreatment and applicable to nontransparent samples.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study investigated whether there was a worsening of the neuromuscular capacity of older adults after the seventh decade of life. The results suggest that the age-related deterioration in maximal strength measures and rapid force production characteristics in older adults could be related to a reduction in the mass and neural activation of the thigh muscles.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper summarises initiatives in the area of capacity building between communities, governments and universities since Rio 1992.

First the global advances through the UN and associated agencies are described with lessons learned and challenges remaining being highlighted. This is followed by a similar approach for first regionally based initiatives and finally some of the better examples of nationally based approaches.

Among the key findings from the review were: trying to keep the initial message simple, asking the “user” what they want and what they need from capacity building, the use of local experts in capacity building where ever possible, universities extending themselves to engage in genuine partnerships as well as offering new courses, subjects, etc., attempting to match the strengths and weaknesses of partners in capacity building, concentrating on improving regional partnerships across national boundaries, deriving methods to sustain capacity building programs over the long term, questioning the absence of the private sector from capacity building partnerships, questioning whether capacity building is receiving the attention, funding and centrality to ICM promotion that it warrants, a proposal to build a global ICM capacity building network, the need for greater critical analysis of capacity building programs, integrating capacity building into ICM practices and recognising that effective capacity building practice may require some time and effort to build up, i.e. there are no universal “quick-fixes”.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article focuses on children’s capacity to exercise legal rights. It is argued that, undisturbed by the High Court’s subsequent decision, the Family Court in B & B & Minister for Immigration and Multicultural & Indigenous Affairs [2003] Fam CA has found that a child’s capacity is qualified only by contingent factors. This represents a significant development of the prevailing Gillick approach for the determination of the competence of children and young people. Where the Gillick approach requires a positive inquiry as to whether the actual maturity level of an
individual child or young person is adequate relative to the question at issue, the new approach focuses on barriers to justice encountered by the child. At least in relation to some matters, capacity is presupposed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There is currently little understanding of the physicochemical properties in the human gastrointestinal tract of Australian sweet lupin (Lupinus angustifolius) kernel fibre (LKF), a novel food ingredient with potential for the fibre enrichment of foods such as baked goods. Since physicochemical properties of dietary fibres have been related to beneficial physiological effects in vitro, this study compared water-binding capacity and viscosity of LKF with that of other fibres currently used for fibre-enrichment of baked goods, under in vitro conditions simulating the human upper gastrointestinal tract. At between 8.47 and 11.07g water/g dry solids, LKF exhibited water-binding capacities that were significantly higher (P<0.05) than soy fibre, pea hull fibre, cellulose and wheat fibre at all of the simulated gastrointestinal stages examined. Similarly, viscosity of LKF was significantly higher (P<0.05) than that of the other fibres at all simulated gastrointestinal stages. The relatively high water-binding capacity and viscosity of LKF identified in this study suggests that this novel fibre ingredient may elicit different and possibly more beneficial physiological effects in the upper human gastrointestinal tract than the conventional fibre ingredients currently used in fibre-enriched baked goods manufacture. We are now performing human studies to investigate the effect of LKF in the diet on health-related gastrointestinal events.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

One of the dominant themes in development programmes over the last fifteen years has been a commitment to capacity building. This paper investigates the forms of capacity building in Aceh, Indonesia, since the devastating earthquake and tsunami that hit the province on 26 December 2004. Despite the preference of the Acehnese people for reconstruction processes based on the principles of community development, local people have been largely marginalized by both the Indonesian government and the international aid and development agencies. The paper suggests some of the reasons for this marginalization.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background and Aims: This paper is the second in a series of two that presents and discusses an exploratory evaluation study of the 'Motor Magic' program conducted in Adelaide, South Australia.

Methods:
A realist evaluation approach was used, and two focus groups (one with parents and one with kindergarten staff) were held to identify program outcomes and to develop and refine key hypotheses about how these outcomes occurred.

Results and Conclusions:
Results for kindergarten staff involved in the program are presented and discussed in this paper, including improved early identification and early intervention for children with, or at risk of, fine motor developmental difficulties; increased confidence in the effectiveness of their practice with these children; improved practice of kindergarten staff with both targeted and all children; improved empathy with, and support for, parents; and increased interagency links and ongoing advocacy for further resources. These results suggest that the program provides an effective model for building the capacity of kindergarten staff to support children with, or at risk of, developmental difficulties.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The silence around overpopulation prevents the global health community from making the necessary link between the planner's limited ability to support its people and health and development crises. The author describes how popular thinking on population control has been shaped over the last 200 years and how out failure to address the population explosion may be one cause of recent epidemics and social unrest.