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101.
doi: 10.1111/j.1741‐2358.2012.00613.x Derivation of the short form of the Oral Health Impact Profile in Spanish (OHIP‐EE‐14) Background and Objective: The Oral Health Impact Profile is the most frequently used and validated of the Oral Health Quality of Life instruments. Several short versions have been developed; and a validation of the OHIP‐49 in Spanish has been published. The objective was to develop the short version of the Oral Health Impact Profile in Spanish (OHIP‐EE‐14). Methods: Cross‐sectional study. One hundred and thirty‐one persons aged ≥60 years attending a social centre for the elderly, residents of a nursing home and persons seeking dental care at a dental school in Mexico City were interviewed and examined. The validity of each of the 49 questions was evaluated, and, to construct the short version, 14 items were selected. The perceived need for dental treatment, number of teeth, presence of coronal caries, root caries, presence of dental plaque and utilisation of removable prosthesis were measured. Internal consistency, repeatability and discriminant validity were calculated. Results: The OHIP‐EE‐14 was reliable (Cronbach’s‐α = 0.918, ICC = 0.825). Significant associations were found between OHIP‐EE‐14 and the number of teeth and perceived need for dental treatment. Conclusions: The OHIP‐EE‐14 is a reliable and valid instrument and can be used in subjects aged 60 years and over from Mexico City. 相似文献
102.
水稻根系通气组织与根系泌氧及根际硝化作用的关系 总被引:9,自引:0,他引:9
通过根箱土培试验研究了不同产量籼稻品种中旱22(ZH,高产品种)及禾盛10号(HS,低产品种)苗期根系生长、通气组织发育、根系径向泌氧量(radial oxygen loss,ROL)以及根表和根际土壤硝化强度差异。结果表明,除水稻播种40 d时二者根数量和根干重无显著差异外,ZH根直径、根数量和根干重均显著高于HS,二者差异尤其表现在根系生物量差异。两个水稻品种在距根尖20 mm处均可见辐射状通气组织,ZH皮层薄壁细胞已经完全崩溃形成连接中柱和外皮层的纵向气腔,而HS皮层薄壁细胞未发生完全离解,但仍能观察到明显的连接中柱和外皮层的纵向气腔的形成。同时ZH外皮层厚壁细胞体积较小,排列紧密,细胞壁增厚程度大;而HS外皮层厚壁细胞体积相对较大,排列疏松,细胞壁增厚程度相对较小。表明高产品种通气组织发育比低产品种更加完善,表现为ZH根孔隙度(porosity of root,POR)显著高于HS,且高产品种对水稻根系ROL的屏蔽作用较低产品种更强,为根系提供更充足的氧气供应,促进根系生长。除了水稻播种后40 d时ZH和HS单根ROL无显著差异外(P<0.05),ZH单株、单位重量以及单根ROL均显著高于HS(P<0.01)。两个水稻品种硝化强度均表现为根际土壤显著高于根表土壤 (P<0.01),前者大约是后者的3-6倍。两个品种根表土壤硝化强度无显著差异,而ZH根际土壤硝化强度均显著高于HS。相关性分析结果表明水稻根际土壤硝化强度和整株水稻ROL呈极显著正相关关系(r=0.803,P<0.01),和水稻POR也呈现极显著正相关关系(r=0.808,P<0.01),同时和根系直径、数量和干重均呈极显著正相关关系(P<0.01)。而根表土壤硝化强度和以上指标均无相关关系。由于硝化作用是好氧过程,因此高产品种由于根系发达,通气组织发育好,相应ROL也较大,造成根际土壤氧气含量高,从而可能导致根际土壤硝化强度显著高于低产品种。 相似文献
103.
桂西南喀斯特地区生物多样性丰富、特有种多, 同时也是石漠化问题较为严重的区域。由于该喀斯特地区土层浅薄、岩石裸露、表层储水能力差, 植物在干旱季节经常会受到水分胁迫。植物水力学特征不仅是探讨喀斯特地区植物的生理生态适应性的关键, 还能够为石漠化地区的植被恢复提供重要参考。该研究测定了桂西南喀斯特季雨林17种代表性木本植物(包括不同生活型、叶片习性和生境)的木质部脆弱性曲线、最低水势、叶片膨压丧失点和边材密度等水力性状, 结果发现: (1)喀斯特植物木质部导水率丧失50%时的水势值(P50)的种间差异较大(-0.51- -2.51 MPa), 其中常绿种的抗栓塞能力比落叶种强; (2)喀斯特植物的木质部水力安全边界值(最低水势与P50之间的差值)的均值为0.36 MPa, 说明喀斯特森林植物在自然最低水势状况下木质部发生栓塞的程度较高; 但是不同植物种间存在显著差异, 这可能与喀斯特峰丛洼地生境的复杂性以及物种不同的抗旱策略有关; (3)由于喀斯特植物水分适应机制的多样化, 导致木质部水力安全边界与叶片膨压丧失点、边材密度的相关性并不显著。在区域气候干热化的背景下, 结合喀斯特植物的栓塞脆弱性和长期水势监测(尤其极端干旱事件)分析它们的水力安全, 对预测未来喀斯特森林物种分布和群落动态具有重要的指示作用。 相似文献
104.
Data for the historical years 1970 and 1995 and the FAO-Agriculture Towards 2030 projection are used to calculate N inputs (N fertilizer, animal manure, biological N fixation and atmospheric deposition) and the N export from the field in harvested crops and grass and grass consumption by grazing animals. In most industrialized countries we see a gradual increase of the overall N recovery of the intensive agricultural production systems over the whole 1970-2030 period. In contrast, low N input systems in many developing countries sustained low crop yields for many years but at the cost of soil fertility by depleting soil nutrient pools. In most developing countries the N recovery will increase in the coming decades by increasing efficiencies of N use in both crop and livestock production systems. The surface balance surplus of N is lost from the agricultural system via different pathways, including NH3 volatilization, denitrification, N2O and NO emissions, and nitrate leaching from the root zone. Global NH3-N emissions from fertilizer and animal manure application and stored manure increased from 18 to 34 Tg·yr-1 between 1970 and 1995, and will further increase to 44 Tg·yr-1 in 2030. Similar developments are seen for N2O-N (2.0 Tg·yr-1 in 1970, 2.7 Tg·yr-1 in 1995 and 3.5 Tg·yr-1 in 2030) and NO-N emissions (1.1 Tg·yr-1 in 1970, 1.5Tg·yr-1 in 1995 and 2.0 Tg·yr-1 in 2030). 相似文献
105.
Xiuli Dan Beimeng Yang Ross A. McDevitt Samuel Gray Xixia Chu Quia Claybourne David M. Figueroa Yongqing Zhang Deborah L. Croteau Vilhelm A. Bohr 《Aging cell》2023,22(4):e13793
Olfactory dysfunction is a prevalent symptom and an early marker of age-related neurodegenerative diseases in humans, including Alzheimer's and Parkinson's Diseases. However, as olfactory dysfunction is also a common symptom of normal aging, it is important to identify associated behavioral and mechanistic changes that underlie olfactory dysfunction in nonpathological aging. In the present study, we systematically investigated age-related behavioral changes in four specific domains of olfaction and the molecular basis in C57BL/6J mice. Our results showed that selective loss of odor discrimination was the earliest smelling behavioral change with aging, followed by a decline in odor sensitivity and detection while odor habituation remained in old mice. Compared to behavioral changes related with cognitive and motor functions, smelling loss was among the earliest biomarkers of aging. During aging, metabolites related with oxidative stress, osmolytes, and infection became dysregulated in the olfactory bulb, and G protein coupled receptor-related signaling was significantly down regulated in olfactory bulbs of aged mice. Poly ADP-ribosylation levels, protein expression of DNA damage markers, and inflammation increased significantly in the olfactory bulb of older mice. Lower NAD+ levels were also detected. Supplementation of NAD+ through NR in water improved longevity and partially enhanced olfaction in aged mice. Our studies provide mechanistic and biological insights into the olfaction decline during aging and highlight the role of NAD+ for preserving smelling function and general health. 相似文献
106.
A. Justin Nowakowski James I. Watling Michelle E. Thompson George A. Brusch IV Alessandro Catenazzi Steven M. Whitfield David J. Kurz Ángela Suárez‐Mayorga Andrés Aponte‐Gutiérrez Maureen A. Donnelly Brian D. Todd 《Ecology letters》2018,21(3):345-355
Human activities often replace native forests with warmer, modified habitats that represent novel thermal environments for biodiversity. Reducing biodiversity loss hinges upon identifying which species are most sensitive to the environmental conditions that result from habitat modification. Drawing on case studies and a meta‐analysis, we examined whether observed and modelled thermal traits, including heat tolerances, variation in body temperatures, and evaporative water loss, explained variation in sensitivity of ectotherms to habitat modification. Low heat tolerances of lizards and amphibians and high evaporative water loss of amphibians were associated with increased sensitivity to habitat modification, often explaining more variation than non‐thermal traits. Heat tolerances alone explained 24–66% (mean = 38%) of the variation in species responses, and these trends were largely consistent across geographic locations and spatial scales. As habitat modification alters local microclimates, the thermal biology of species will likely play a key role in the reassembly of terrestrial communities. 相似文献
107.
István Tátrai 《Hydrobiologia》1982,96(2):129-135
The oxygen consumption and ammonia excretion of a herbivorous midge larva,Chironomus sp., inhabiting Lake Balaton was measured at two different temperatures. The loss of energy through respiration and that through ammonia excretion were calculated. The daily respiratory energy loss amounted to 655.5 ± 123.8 J g–1 at 17 °C and to 1 160.0 ± 168.4 J g–1 (dry weight) at 25 °C. Mean energy loss through ammonia excretion was about 40% less than through respiration. 相似文献
108.
The partial CaDSR6 (Capsicum annuum Drought Stress Responsive 6) cDNA was previously identified as a drought-induced gene in hot pepper root tissues. However, the cellular role of CaDSR6 with regard to drought stress tolerance was unknown. In this report, full-length CaDSR6 cDNA was isolated. The deduced CaDSR6 protein was composed of 234 amino acids and contained an approximately 30 amino acid-long Asp-rich domain in its central region. This Asp-rich domain was highly conserved in all plant DSR6 homologs identified and shared a sequence identity with the N-terminal regions of yeast p23fyp and human hTCTP, which contain Rab protein binding sites. Transgenic Arabidopsis plants overexpressing CaDSR6 (35S:CaDSR6-sGFP) were tolerant to high salinity, as identified by more vigorous root growth and higher levels of total chlorophyll than wild type plants. CaDSR6-overexpressors were also more tolerant to drought stress compared to wild type plants. The 35S:CaDSR6-sGFP leaves retained their water content and chlorophyll more efficiently than wild type leaves in response to dehydration stress. The expression of drought-induced marker genes, such as RD20, RD22, RD26, RD29A, RD29B, RAB18, KIN2, ABF3, and ABI5, was markedly increased in CaDSR6-overexpressing plants relative to wild type plants under both normal and drought conditions. These results suggest that overexpression of CaDSR6 is associated with increased levels of stress-induced genes, which, in turn, conferred a drought tolerant phenotype in transgenic Arabidopsis plants. Overall, our data suggest that CaDSR6 plays a positive role in the response to drought and salt stresses. 相似文献
109.
110.
Introductions do not compensate for functional and phylogenetic losses following extinctions in insular bird assemblages 下载免费PDF全文
The ratio of species extinctions to introductions has been comparable for many insular assemblages, suggesting that introductions could have ‘compensated’ for extinctions. However, the capacity for introduced species to replace ecological roles and evolutionary history lost following extinction is unclear. We investigated changes in bird functional and phylogenetic diversity in the wake of extinctions and introductions across a sample of 32 islands worldwide. We found that extinct and introduced species have comparable functional and phylogenetic alpha diversity. However, this was distributed at different positions in functional space and in the phylogeny, indicating a ‘false compensation’. Introduced and extinct species did not have equivalent functional roles nor belong to similar lineages. This makes it unlikely that novel island biotas composed of introduced taxa will be able to maintain ecological roles and represent the evolutionary histories of pre‐disturbance assemblages and highlights the importance of evaluating changes in alpha and beta diversity concurrently. 相似文献