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891.
Fire‐related heat and endozoochory by elephants have independently been found to be important for savanna plant seed germination, yet there is little information on how heat affects germination of elephant‐dispersed seeds. We measured the germination behavior (time to germination and proportion of seeds germinating) of 11 species of seeds extracted from African savanna elephant dung and subjected them to various intensities of heat as a proxy for fire exposure. The effects of heat were inconsistent and varied significantly by species, with some species having increased time to germination in response to heat and others having reduced time to germination. More studies are needed to expand the number of seed species examined and tease apart the interaction between elephant‐mediated endozoochory and fire.  相似文献   
892.
893.

Background

Third-generation cryoballoon (CB3) is characterized by a 40% shorter distal tip designed to increase the rate of pulmonary veins real-time signal recording in order to measure time necessary to isolate veins, the “Time to effect” (TTE). Few data are currently available on clinical follow up of CB3 treated patients.

Methods

Sixtyeight consecutive patients (mean age 57.8?±?9.6 years, 48 male) with paroxysmal or persistent atrial fibrillation (AF) were enrolled. Thirthyfour (25 paroxysmal AF) underwent to a 28 mmCB3 pulmonary veins isolation and were compared to 34 treated (21 paroxysmal AF) with 28 mmCB2.

Results

CB3 use was correlated to significant increase of the possibility to measure TTE in every treated veins (left superior 82,35% vs 23,53%, left inferior 70,59% vs 38,24%, right superior 58,82% vs 14,71%, right inferior 52,94% vs 17,65%). When it is measured, TTE wasn't different between two groups. Higher nadir temperature was observed in CB3 patients (?39.4?±?5.2?°C vs ?43.0?±?7.2?°C, p?=?0.03). CB3 procedures were shorter (91.4?±?21.7 vs 110.9?±?31.8?min, p?=?0.018), with a significant reduction in cryoenergy delivery time (24.2?±?8.5 vs 20.3?±?6.7?min, p?<?0.05), and a significant reduction in left atrium dwell time (59.3?±?9.8 vs 69.3?±?10.8?min, p?=?0.02, p?<?0.05). At one year follow up period the Kaplan-Meier curve didn't show any significant difference in AF-free survival (Log p?=?0,49).

Conclusions

Novel CB3 is a useful tool in order to simplify AF cryoballoon ablation when compared to second generation cryoballoon, as observed in our experience. Follow up data seem confirm a clinical CB3 efficacy at least comparable CB2.  相似文献   
894.
895.
896.

Background

Past experience and modelling suggest that, in most cases, mass treatment strategies are not likely to succeed in interrupting Plasmodium falciparum malaria transmission. However, this does not preclude their use to reduce disease burden. Mass screening and treatment (MSAT) is preferred to mass drug administration (MDA), as the latter involves massive over-use of drugs. This paper reports simulations of the incremental cost-effectiveness of well-conducted MSAT campaigns as a strategy for P. falciparum malaria disease-burden reduction in settings with varying receptivity (ability of the combined vector population in a setting to transmit disease) and access to case management.

Methods

MSAT incremental cost-effectiveness ratios (ICERs) were estimated in different sub-Saharan African settings using simulation models of the dynamics of malaria and a literature-based MSAT cost estimate. Imported infections were simulated at a rate of two per 1,000 population per annum. These estimates were compared to the ICERs of scaling up case management or insecticide-treated net (ITN) coverage in each baseline health system, in the absence of MSAT.

Results

MSAT averted most episodes, and resulted in the lowest ICERs, in settings with a moderate level of disease burden. At a low pre-intervention entomological inoculation rate (EIR) of two infectious bites per adult per annum (IBPAPA) MSAT was never more cost-effective than scaling up ITNs or case management coverage. However, at pre-intervention entomological inoculation rates (EIRs) of 20 and 50 IBPAPA and ITN coverage levels of 40 or 60%, respectively, the ICER of MSAT was similar to that of scaling up ITN coverage further.

Conclusions

In all the transmission settings considered, achieving a minimal level of ITN coverage is a “best buy”. At low transmission, MSAT probably is not worth considering. Instead, MSAT may be suitable at medium to high levels of transmission and at moderate ITN coverage. If undertaken as a burden-reducing intervention, MSAT should be continued indefinitely and should complement, not replace, case management and vector control interventions.  相似文献   
897.
An extensive survey of wild Sicilian oregano was made. A total of 57 samples were collected from various sites, followed by taxonomic characterization from an agronomic perspective. Based on morphological and production characteristics obtained from the 57 samples, cluster analysis was used to divide the samples into homogeneous groups, to identify the best biotypes. All samples were analyzed for their phytochemical content, applying a cascade‐extraction protocol and hydrodistillation, to obtain the non volatile components and the essential oils, respectively. The extracts contained thirteen polyphenol derivatives, i.e., four flavanones, seven flavones, and two organic acids. Their qualitative and quantitative characterization was carried out by LC/MS analyses. The essential oils were characterized using a combination of GC‐FID and GC/MS analyses; a total of 81 components were identified. The major components of the oils were thymol, p‐cymene, and γ‐terpinene. Cluster analysis was carried out on both phytochemical profiles and resulted in the division of the oregano samples into different chemical groups. The antioxidant activity of the essential oils and extracts was investigated by the Folin? Ciocalteau (FC) colorimetric assay, by UV radiation‐induced peroxidation in liposomal membranes (UV‐IP test), and by determining the O ‐scavenging activity.  相似文献   
898.
A continuum mixture model with distinct collagen (COL) and glycosaminoglycan elastic constituents was developed for the solid matrix of immature bovine articular cartilage. A continuous COL fiber volume fraction distribution function and a true COL fiber elastic modulus ( $E^\mathrm{f})$ were used. Quantitative polarized light microscopy (qPLM) methods were developed to account for the relatively high cell density of immature articular cartilage and used with a novel algorithm that constructs a 3D distribution function from 2D qPLM data. For specimens untreated and cultured in vitro, most model parameters were specified from qPLM analysis and biochemical assay results; consequently, $E^\mathrm{f}$ was predicted using an optimization to measured mechanical properties in uniaxial tension and unconfined compression. Analysis of qPLM data revealed a highly anisotropic fiber distribution, with principal fiber orientation parallel to the surface layer. For untreated samples, predicted $E^\mathrm{f}$ values were 175 and 422 MPa for superficial (S) and middle (M) zone layers, respectively. TGF- $\upbeta $ 1 treatment was predicted to increase and decrease $E^\mathrm{f}$ values for the S and M layers to 281 and 309 MPa, respectively. IGF-1 treatment was predicted to decrease $E^\mathrm{f}$ values for the S and M layers to 22 and 26 MPa, respectively. A novel finding was that distinct native depth-dependent fiber modulus properties were modulated to nearly homogeneous values by TGF- $\upbeta $ 1 and IGF-1 treatments, with modulated values strongly dependent on treatment.  相似文献   
899.
The influence of larval diet source in Sitophilus oryzae (L.), a primary grain feeder, on the choice of a new cereal host by young adult was investigated through a multiple choice comparative bioassay. For this purpose, virgin male and female adults, which had been reared as immatures in different grain commodities, were monitored according to their food preference in cylindrical arenas containing whole kernels of maize, rice, barley and wheat. The adults showed a clear individual preference for maize kernels, regardless of the previous food experience, sex and also the interval on which the adults are exposed to food. Males were much more mobile than females and visited more vigorously different commodities before the final choice. Female response was found to be related with male response to specific food sources. Hence, our results indicate that there was no natal habitat preference induction, since maize was, in most cases, the final commodity choice.  相似文献   
900.
Differences in the inherent properties of adipose tissue-derived stem cells (ASC) may contribute to the biological specificity of the subcutaneous (Sc) and visceral (V) adipose tissue depots. In this study, three distinct subpopulations of ASC, i.e. ASCSVF, ASCBottom, and ASCCeiling, were isolated from Sc and V fat biopsies of non-obese subjects, and their gene expression and functional characteristics were investigated. Genome-wide mRNA expression profiles of ASCSVF, ASCBottom and ASCCeiling from Sc fat were significantly different as compared to their homologous subsets of V-ASCs. Furthermore, ASCSVF, ASCCeiling and ASCBottom from the same fat depot were also distinct from each other. In this respect, both principal component analysis and hierarchical clusters analysis showed that ASCCeiling and ASCSVF shared a similar pattern of closely related genes, which was highly different when compared to that of ASCBottom. However, larger variations in gene expression were found in inter-depot than in intra-depot comparisons. The analysis of connectivity of genes differently expressed in each ASC subset demonstrated that, although there was some overlap, there was also a clear distinction between each Sc-ASC and their corresponding V-ASC subsets, and among ASCSVF, ASCBottom, and ASCCeiling of Sc or V fat depots in regard to networks associated with regulation of cell cycle, cell organization and development, inflammation and metabolic responses. Finally, the release of several cytokines and growth factors in the ASC cultured medium also showed both inter- and intra-depot differences. Thus, ASCCeiling and ASCBottom can be identified as two genetically and functionally heterogeneous ASC populations in addition to the ASCSVF, with ASCBottom showing the highest degree of unmatched gene expression. On the other hand, inter-depot seem to prevail over intra-depot differences in the ASC gene expression assets and network functions, contributing to the high degree of specificity of Sc and V adipose tissue in humans.  相似文献   
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