998 resultados para leaf appearance rate


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The cuticle covers the aerial parts of land plants, where it serves many important functions, including water retention. Here, a recessive cuticle mutant, eceriferum-ym (cer-ym), of Hordeum vulgare L. (barley) showed abnormally glossy spikes, sheaths, and leaves. The cer-ym mutant plant detached from its root system was hypersensitive to desiccation treatment compared with wild type plants, and detached leaves of mutant lost 41.8% of their initial weight after 1 h of dehydration under laboratory conditions, while that of the wild type plants lost only 7.1%. Stomata function was not affected by the mutation, but the mutant leaves showed increased cuticular permeability to water, suggesting a defective leaf cuticle, which was confirmed by toluidine blue staining. The mutant leaves showed a substantial reduction in the amounts of the major cutin monomers and a slight increase in the main wax component, suggesting that the enhanced cuticle permeability was a consequence of cutin deficiency. cer-ym was mapped within a 0.8 cM interval between EST marker AK370363 and AK251484, a pericentromeric region on chromosome 4H. The results indicate that the desiccation sensitivity of cer-ym is caused by a defect in leaf cutin, and that cer-ym is located in a chromosome 4H pericentromeric region.

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The magnetostratigraphic analysis of the middle to late Miocene continental deposits from the Valles-Penedes basin, combined with its well-documented fossil mammal record, provides a well-resoluted chronology for the upper basin infill. It is based on the biostratigraphic and magnetostratigraphic cross-correlation of 18 sections throughout the alluvial and transitional/shallow marine sequences in the Western Valles area. The biostratigraphic framework consists of 24 mammal localities of upper Aragonian and Vallesian age. Correlation of the studied sections to the geomagnetic polarity time scale (GPTS) is based on the distinctive pattern of local magnetozones, as well as the radiometric age of the late Vallesian fauna from the Bicorp Basin (9.6 + 0.3 Ma) and the known relationship of the late Vallesian assemblages with marine beds belonging to the planktonic forarninifera N16 zone. It has led to an absolute dating of the fauna1 events and a precise chronostratigraphy of the Vallesian marnrnal stage in its type area. The Hipparion First Appearance Datum (FAD) defines the lower Vallesian boundary and is dated at 11.1 Ma, at the base of chron C5r. ln. It is in good agreement with radiometric ages from the early Hipparion bearing sites in the Vienna Basin (1 1.1 * 0.5 Ma) and the classic Howenegg locality in Germany (10.8 * 0.3 Ma). It also agrees with the age of the turkish localities of Yailacilar (1 1.6 + 0.25 Ma) and Yenieskihisar-2 (1 1.1 * 0.2 Ma) with absence of Hipparion. Al1 these support the isochrony of the dispersa1 of Hipparion throughout the Mediterranean region. A possible isochrony at a larger geographical scale (Old World, Mesogea) must await more reliable ages of the Hipparion FAD in Asia and Africa. The Cricetulodon FAD that defines the MN9a/MN9b boundary occurs at the middle part of C5n. Assuming an on average constant sedimentation rate, this datum has an age of approximately 10.4 Ma. The earlyllate Vallesian boundary is marked by one of the most distinct fauna1 events of the late Neogene: the dispersa1 of the muridae Progonomys into Europe and North Africa, which coincides with an important macromarnmal turnover. The first extensive appearance of Progonomys in Europe (MN9íMN10 boundary) is dated at 9.7 Ma (C4Ar3r), showing a remarkable diachrony with the Himalayan region. F9i d lly, the FAD of Rotundomys bressnnus occurs in the upper part of C4Ar.ln (9.2-9.3 Ma). The Vallesian spans 2.4 Myr, from 11.1 Ma (CSr.ln) to 8.7 Ma (C4An), and correlates to the early Tortonian.

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DNA is nowadays swabbed routinely to investigate serious and volume crimes, but research remains scarce when it comes to determining the criteria that may impact the success rate of DNA swabs taken on different surfaces and situations. To investigate these criteria in fully operational conditions, DNA analysis results of 4772 swabs taken by the forensic unit of a police department in Western Switzerland over a 2.5-year period (2012-2014) in volume crime cases were considered. A representative and random sample of 1236 swab analyses was extensively examined and codified, describing several criteria such as whether the swabbing was performed at the scene or in the lab, the zone of the scene where it was performed, the kind of object or surface that was swabbed, whether the target specimen was a touch surface or a biological fluid, and whether the swab targeted a single surface or combined different surfaces. The impact of each criterion and of their combination was assessed in regard to the success rate of DNA analysis, measured through the quality of the resulting profile, and whether the profile resulted in a hit in the national database or not. Results show that some situations - such as swabs taken on door and window handles for instance - have a higher success rate than average swabs. Conversely, other situations lead to a marked decrease in the success rate, which should discourage further analyses of such swabs. Results also confirm that targeting a DNA swab on a single surface is preferable to swabbing different surfaces with the intent to aggregate cells deposited by the offender. Such results assist in predicting the chance that the analysis of a swab taken in a given situation will lead to a positive result. The study could therefore inform an evidence-based approach to decision-making at the crime scene (what to swab or not) and at the triage step (what to analyse or not), contributing thus to save resource and increase the efficiency of forensic science efforts.

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Data concerning the effect of temperature on different physiological parameters of an invasive species can be a useful tool to predict its potential distribution range through the use of modelling approaches. In the case of the Argentine ant these data are too scarce and incomplete. The aim of the present study is to compile new data regarding the effect of temperature on the oviposition rate of the Argentine ant queens. We analysed the oviposition rate of queens at twelve controlled temperatures, ranging from 10ºC to 34ºC under different monogynous and polygynous conditions. The oviposition rate of the Argentine ant queens is affected by temperature in the same manner, independently of the number of queens in the nest. The optimal temperature for egg laying was 28ºC, and its upper and lower limits depended on the degree of polygyny

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The cuticle is an essential diffusion barrier on aerial surfaces of land plants whose structural component is the polyester cutin. The PERMEABLE CUTICLE1/ABCG32 (PEC1) transporter is involved in plant cuticle formation in Arabidopsis. The gpat6 pec1 and gpat4 gapt8 pec1 double and triple mutants are characterized. Their PEC1-specific contributions to aliphatic cutin composition and cuticle formation during plant development are revealed by gas chromatography/mass spectrometry and Fourier-transform infrared spectroscopy. The composition of cutin changes during rosette leaf expansion in Arabidopsis. C16:0 monomers are in higher abundance in expanding than in fully expanded leaves. The atypical cutin monomer C18:2 dicarboxylic acid is more prominent in fully expanded leaves. Findings point to differences in the regulation of several pathways of cutin precursor synthesis. PEC1 plays an essential role during expansion of the rosette leaf cuticle. The reduction of C16 monomers in the pec1 mutant during leaf expansion is unlikely to cause permeability of the leaf cuticle because the gpat6 mutant with even fewer C16:0 monomers forms a functional rosette leaf cuticle at all stages of development. PEC1/ABCG32 transport activity affects cutin composition and cuticle structure in a specific and non-redundant fashion.

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BACKGROUND: Smoking is an important cardiovascular disease risk factor, but the mechanisms linking smoking to blood pressure are poorly understood. METHODS AND RESULTS: Data on 141 317 participants (62 666 never, 40 669 former, 37 982 current smokers) from 23 population-based studies were included in observational and Mendelian randomization meta-analyses of the associations of smoking status and smoking heaviness with systolic and diastolic blood pressure, hypertension, and resting heart rate. For the Mendelian randomization analyses, a genetic variant rs16969968/rs1051730 was used as a proxy for smoking heaviness in current smokers. In observational analyses, current as compared with never smoking was associated with lower systolic blood pressure and diastolic blood pressure and lower hypertension risk, but with higher resting heart rate. In observational analyses among current smokers, 1 cigarette/day higher level of smoking heaviness was associated with higher (0.21 bpm; 95% confidence interval 0.19; 0.24) resting heart rate and slightly higher diastolic blood pressure (0.05 mm Hg; 95% confidence interval 0.02; 0.08) and systolic blood pressure (0.08 mm Hg; 95% confidence interval 0.03; 0.13). However, in Mendelian randomization analyses among current smokers, although each smoking increasing allele of rs16969968/rs1051730 was associated with higher resting heart rate (0.36 bpm/allele; 95% confidence interval 0.18; 0.54), there was no strong association with diastolic blood pressure, systolic blood pressure, or hypertension. This would suggest a 7 bpm higher heart rate in those who smoke 20 cigarettes/day. CONCLUSIONS: This Mendelian randomization meta-analysis supports a causal association of smoking heaviness with higher level of resting heart rate, but not with blood pressure. These findings suggest that part of the cardiovascular risk of smoking may operate through increasing resting heart rate.

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This study investigated changes in heart rate variability (HRV) in elite Nordic-skiers to characterize different types of "fatigue" in 27 men and 30 women surveyed from 2004 to 2008. R-R intervals were recorded at rest during 8 min supine (SU) followed by 7 min standing (ST). HRV parameters analysed were powers of low (LF), high (HF) frequencies, (LF+HF) (ms(2)) and heart rate (HR, bpm). In the 1 063 HRV tests performed, 172 corresponded to a "fatigue" state and the first were considered for analysis. 4 types of "fatigue" (F) were identified: 1. F(HF(-)LF(-))SU_ST for 42 tests: decrease in LFSU (- 46%), HFSU (- 70%), LFST (- 43%), HFST (- 53%) and increase in HRSU (+ 15%), HRST (+ 14%). 2. F(LF(+) SULF(-) ST) for 8 tests: increase in LFSU (+ 190%) decrease in LFST (- 84%) and increase in HRST (+ 21%). 3. F(HF(-) SUHF(+) ST) for 6 tests: decrease in HFSU (- 72%) and increase in HFST (+ 501%). 4. F(HF(+) SU) for only 1 test with an increase in HFSU (+ 2161%) and decrease in HRSU (- 15%). Supine and standing HRV patterns were independently modified by "fatigue". 4 "fatigue"-shifted HRV patterns were statistically sorted according to differently paired changes in the 2 postures. This characterization might be useful for further understanding autonomic rearrangements in different "fatigue" conditions.

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PURPOSE: Pencil beam scanning and filter free techniques may involve dose-rates considerably higher than those used in conventional external-beam radiotherapy. Our purpose was to investigate normal tissue and tumour responses in vivo to short pulses of radiation. MATERIAL AND METHODS: C57BL/6J mice were exposed to bilateral thorax irradiation using pulsed (at least 40Gy/s, flash) or conventional dose-rate irradiation (0.03Gy/s or less) in single dose. Immunohistochemical and histological methods were used to compare early radio-induced apoptosis and the development of lung fibrosis in the two situations. The response of two human (HBCx-12A, HEp-2) tumour xenografts in nude mice and one syngeneic, orthotopic lung carcinoma in C57BL/6J mice (TC-1 Luc+), was monitored in both radiation modes. RESULTS: A 17Gy conventional irradiation induced pulmonary fibrosis and activation of the TGF-beta cascade in 100% of the animals 24-36 weeks post-treatment, as expected, whereas no animal developed complications below 23Gy flash irradiation, and a 30Gy flash irradiation was required to induce the same extent of fibrosis as 17Gy conventional irradiation. Cutaneous lesions were also reduced in severity. Flash irradiation protected vascular and bronchial smooth muscle cells as well as epithelial cells of bronchi against acute apoptosis as shown by analysis of caspase-3 activation and TUNEL staining. In contrast, the antitumour effectiveness of flash irradiation was maintained and not different from that of conventional irradiation. CONCLUSION: Flash irradiation shifted by a large factor the threshold dose required to initiate lung fibrosis without loss of the antitumour efficiency, suggesting that the method might be used to advantage to minimize the complications of radiotherapy.

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The differentiation of workers into morphological subcastes (e.g., soldiers) represents an important evolutionary transition and is thought to improve division of labor in social insects. Soldiers occur in many ant and termite species, where they make up a small proportion of the workforce. A common assumption of worker caste evolution is that soldiers are behavioral specialists. Here, we report the first test of the "rare specialist" hypothesis in a eusocial bee. Colonies of the stingless bee Tetragonisca angustula are defended by a small group of morphologically differentiated soldiers. Contrary to the rare specialist hypothesis, we found that soldiers worked more (+34%-41%) and performed a greater variety of tasks (+23%-34%) than other workers, particularly early in life. Our results suggest a "rare elite" function of soldiers in T. angustula, that is, that they perform a disproportionately large amount of the work. Division of labor was based on a combination of temporal and physical castes, but soldiers transitioned faster from one task to the next. We discuss why the rare specialist assumption might not hold in species with a moderate degree of worker differentiation.

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Estimation of human oxygen uptake (V˙o2) during exercise is often used as an alternative when its direct measurement is not feasible. The American College of Sports Medicine (ACSM) suggests estimating human V˙o2 during exercise on a cycle ergometer through an equation that considers individual's body mass and external work rate, but not pedaling rate (PR). We hypothesized that including PR in the ACSM equation would improve its V˙o2 prediction accuracy. Ten healthy male participants' (age 19-48 years) were recruited and their steady-state V˙o2 was recorded on a cycle ergometer for 16 combinations of external work rates (0, 50, 100, and 150 W) and PR (50, 70, 90, and 110 revolutions per minute). V˙o2 was calculated by means of a new equation, and by the ACSM equation for comparison. Kinematic data were collected by means of an infrared 3-D motion analysis system in order to explore the mechanical determinants of V˙o2. Including PR in the ACSM equation improved the accuracy for prediction of sub-maximal V˙o2 during exercise (mean bias 1.9 vs. 3.3 mL O2 kg(-1) min(-1)) but it did not affect the accuracy for prediction of maximal V˙o2 (P > 0.05). Confirming the validity of this new equation, the results were replicated for data reported in the literature in 51 participants. We conclude that PR is an important determinant of human V˙o2 during cycling exercise, and it should be considered when predicting oxygen consumption.

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Prompt production of charmonium χ c0, χ c1 and χ c2 mesons is studied using proton-proton collisions at the LHC at a centre-of-mass energy of TeX TeV. The χ c mesons are identified through their decay to J/ψγ, with J/ψ → μ + μ − using photons that converted in the detector. A data sample, corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb detector, is used to measure the relative prompt production rate of χ c1 and χ c2 in the rapidity range 2.0 < y < 4.5 as a function of the J/ψ transverse momentum from 3 to 20 GeV/c. First evidence for χ c0 meson production at a high-energy hadron collider is also presented.