Obesity Might Be a Predictor of Weight Reduction after Smoking Cessation

Background and Objectives. Approximately one in five ex-smokers reduces or maintains weight after smoking cessation but little is known about who succeeds to avoid weight gain. The purpose of this study was to identify predictors of weight reduction after long-term smoking cessation in a general population. Methods. Data was obtained from two Danish population-based cohorts (the Inter99 and the Helbred2006 study). Anthropometric measurements were performed by trained research staff. Out of 3.577 daily smokers at baseline 317 participants had quit smoking at the five-year follow-up for at least one year. Multiple logistic regression analysis was performed to determine predictors of weight reduction. Results. Thirteen percent reduced weight by at least 1 kg and 4% maintained their weight. Quitters with obesity had more than seven times higher odds than normal weight quitters to lose weight (OR 7.13 (95% CI 2.76–19.71)), and they had the largest median weight loss of 4.45 kg. The only other significant predictor of weight reduction was low tobacco consumption at baseline. Conclusions. Predictors of weight reduction after smoking cessation were high body mass index and low tobacco consumption at baseline. This study might motivate smokers with obesity to quit smoking and health professionals to give them support

Age-related decline in associative learning in healthy Chinese adults

10.1371/journal.pone.0080648PLoS ONE811-POLN

Non-structural carbohydrates in woody plants compared among laboratories

Non-structural carbohydrates (NSC) in plant tissue are frequently quantified to make inferences about plant responses to environmental conditions. Laboratories publishing estimates of NSC of woody plants use many different methods to evaluate NSC. We asked whether NSC estimates in the recent literature could be quantitatively compared among studies. We also asked whether any differences among laboratories were related to the extraction and quantification methods used to determine starch and sugar concentrations. These questions were addressed by sending sub-samples collected from five woody plant tissues, which varied in NSC content and chemical composition, to 29 laboratories. Each laboratory analyzed the samples with their laboratory-specific protocols, based on recent publications, to determine concentrations of soluble sugars, starch and their sum, total NSC. Laboratory estimates differed substantially for all samples. For example, estimates for Eucalyptus globulus leaves (EGL) varied from 23 to 116 (mean = 56) mg g⁻¹ for soluble sugars, 6–533 (mean = 94) mg g⁻¹ for starch and 53–649 (mean = 153) mg g⁻¹ for total NSC. Mixed model analysis of variance showed that much of the variability among laboratories was unrelated to the categories we used for extraction and quantification methods (method category R² = 0.05–0.12 for soluble sugars, 0.10–0.33 for starch and 0.01–0.09 for total NSC). For EGL, the difference between the highest and lowest least squares means for categories in the mixed model analysis was 33 mg g⁻¹ for total NSC, compared with the range of laboratory estimates of 596 mg g⁻¹. Laboratories were reasonably consistent in their ranks of estimates among tissues for starch (r = 0.41–0.91), but less so for total NSC (r = 0.45–0.84) and soluble sugars (r = 0.11–0.83). Our results show that NSC estimates for woody plant tissues cannot be compared among laboratories. The relative changes in NSC between treatments measured within a laboratory may be comparable within and between laboratories, especially for starch. To obtain comparable NSC estimates, we suggest that users can either adopt the reference method given in this publication, or report estimates for a portion of samples using the reference method, and report estimates for a standard reference material. Researchers interested in NSC estimates should work to identify and adopt standard methods.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Oxford University Press. The published article can be found at: http://treephys.oxfordjournals.org/Keywords: soluble sugars, starch, particle size, reference method, standardization, non-structural carbohydrate chemical analysis, extraction and quantification consistenc

UV-B impact on aphid performance mediated by plant quality and plant changes induced by aphids

Kuhlmann F, Müller C. UV-B impact on aphid performance mediated by plant quality and plant changes induced by aphids. PLANT BIOLOGY. 2010;12(4):676-684.Plants face various abiotic and biotic environmental factors and therefore need to adjust their phenotypic traits on several levels. UV-B radiation is believed to impact herbivorous insects via host plant changes. Plant responses to abiotic challenges (UV-B radiation) and their interaction with two aphid species were explored in a multifactor approach. Broccoli plants [Brassica oleracea L. convar. botrytis (L.), Brassicaceae] were grown in two differently covered greenhouses, transmitting either 80% (high UV-B) or 4% (low UV-B) of ambient UV-B. Three-week-old plants were infested with either specialist cabbage aphids [Brevicoryne brassicae (L.), Sternorrhyncha, Aphididae] or generalist green peach aphids [Myzus persicae (Sulzer), Sternorrhyncha, Aphididae]. Plants grown under high-UV-B intensities were smaller and had higher flavonoid concentrations. Furthermore, these plants had reduced cuticular wax coverage, whereas amino acid concentrations of the phloem sap were little influenced by different UV-B intensities. Cabbage aphids reproduced less on plants grown under high UV-B than on plants grown under low UV-B, whereas reproduction of green peach aphids in both plant light sources was equally poor. These results are likely related to the different specialisation-dependent sensitivities of the two species. The aphids also affected plant chemistry. High numbers of cabbage aphid progeny on low-UV-B plants led to decreased indolyl glucosinolate concentrations. The induced change in these glucosinolates may depend on an infestation threshold. UV-B radiation considerably impacts plant traits and subsequently affects specialist phloem-feeding aphids, whereas aphid growth forces broccoli to generate specific defence responses

Development-dependent effects of UV radiation exposure on broccoli plants and interactions with herbivorous insects

Kuhlmann F, Müller C. Development-dependent effects of UV radiation exposure on broccoli plants and interactions with herbivorous insects. ENVIRONMENTAL AND EXPERIMENTAL BOTANY. 2009;66(1):61-68.The responses of plants to stress can highly depend on their developmental stage and furthermore influence biotic interactions. Effects of outdoor exposure to different ambient radiation conditions including (+UV) or excluding (-UV) solar ultraviolet radiation were investigated in broccoli plants (Brassica oleracea L. convar. botrytis) at two developmental stages. Plants either germinated directly under these different outdoor UV conditions, or were first kept for three weeks in a climate chamber under low radiation before outside exposure at +UV and -UV. Access of herbivores to the plants was possible under the outdoor conditions. Plants of both groups protected their tissue against destructive UV by increasing concentrations of phenolic compounds (flavonoids and hydroxycinnamic acids) after +UV exposure. But only plants that germinated under +UV conditions kept smaller than plants grown under -UV conditions, indicating certain costs for production of phenolics or for other potential metabolic processes specifically in young, growing plants. In contrast, growth of plants transferred at a later stage did not differ under both UV conditions. Thus, plants responded much more sensitive to the environment they experienced at first growth. Glucosinolates, the characteristic secondary compounds of Brassicaceae, as well as proteinase inhibitors, remained unaffected by UV in all plants, demonstrating independent regulation pathways for different metabolites. Plant infestation by phloem-feeding insects, Aleyrodidae and Aphididae, was more pronounced on +UV exposed plants, whereas cell content feeders, like Thripidae were more abundant on plants under the -UV condition. Choice experiments with the cabbage whitefly Aleyrodes proletella L. (Aleyrodidae), commonly found on Brassica spp., revealed that the key environmental cue navigating their behaviour seems to be the radiation composition, rather than plant quality itself. In conclusion, stress mediated changes of plant chemistry and morphology depend on the plant life cycle stage and are not necessarily mirrored in the behavioural responses of herbivorous insects. (c) 2009 Elsevier B.V. All rights reserved

Revised determination of free and complexed myrosinase activities in plant extracts

Travers-Martin N, Kuhlmann F, Müller C. Revised determination of free and complexed myrosinase activities in plant extracts. PLANT PHYSIOLOGY AND BIOCHEMISTRY. 2008;46(4):506-516.The enzyme myrosinase (thioglucoside glucohydrolase, EC 3.2.1.147, formerly EC 3.2.3.1) catalyzes the hydrolysis of glucosinolates after tissue damage in plants of the order Brassicales. The various myrosinase isoforms occur either as free soluble dimers or as insoluble complexes. We propose a reliable method for determination of both soluble and insoluble myrosinase activity concentrations in partially purified plant extracts. The procedure requires the removal of endogenous glucosinolates through ion-exchange columns previous to enzyme measurements. Myrosinase activity was assayed in continuous mode by photometric quantification of the released glucose using glucose-oxidase with peroxidase and colorimetric indicators. The measurement of the colored product at 492 nm has a favorable signal to noise ratio both in clear extract solutions (free dinners) and in turbid pellet suspensions (insoluble complexes). No interferences by ascorbic acid were found in continuous analyses. With the recommended sample preparation methods and assay conditions potential activities in damaged plant tissues can be characterized which are involved in plant defense mechanisms. (C) 2008 Elsevier Masson SAS. All rights reserved

Impact of ultraviolet radiation on interactions between plants and herbivorous insects: a chemo-ecological perspective

Kuhlmann F, Müller C. Impact of ultraviolet radiation on interactions between plants and herbivorous insects: a chemo-ecological perspective. In: Lüttge UE, Beyschlag W, Büdel B, Francis D, eds. Progress in Botany 72. Berlin: Springer Science + Business Media; 2011: 305-347