Early Growth Period Research Articles

Induction of adipose-derived stem cells on injectable nanofibrous spongy microspheres for vascularized adipose tissue regeneration in vivo

Event Abstract Back to Event Induction of adipose-derived stem cells on injectable nanofibrous spongy microspheres for vascularized adipose tissue regeneration in vivo Yasmine Doleyres1, Xiaobing Jin2 and Peter X. Ma1, 2, 3, 4 1 University of Michigan, Macromolecular Science and Engineering Program, United States 2 University of Michigan, Department of Biologic and Materials Sciences, United States 3 University of Michigan, Department of Biomedical Engineering, United States 4 University of Michigan, Department of Materials Science and Engineering, United States Soft tissue defects in the craniofacial region or the breast region often occur due to congenital defects, traumatic injury, or cancer occurring in the underlying tissue[1]. Correcting these defects in the case of facial reconstruction can be done by transplanting adipose (fat) tissue from another area of the body into the facial region or in the case of reconstruction following breast cancer can be done through autologous tissue transplantation, if available, or using silicone or saline-filled implants. The problem with these options is that between 20-90% of transplanted fat tissue often resorbs within a couple months after being transplanted due to lack of vascularization and implants often fail because of capsular constriction and become infected, leading to multiple surgeries in both cases[1]-[8]. The most ideal option would be to regenerate one’s own adipose tissue just as it is naturally produced by the body. Lasting tissue regeneration options for in vivo adipose tissue have yet to be developed, and this is the goal of this project. Novel nanofibrous spongy (porous) microspheres (NF-SMS) have been developed and appear to be a suitable scaffolding or cell-carrying material for the differentiation and growth of adipose-derived stem cells (ASCs). These microspheres made of poly-L-lactic acid (PLLA) have a nanofibrous architecture that well-mimics the cells’ natural extracellular matrix and also allows for cells to pack the interior of the microspheres[9]. A high number of cells are able to pack into the interior of the microspheres and the high cell attachment on the microspheres is critical for adipose tissue regeneration as high cell-cell contact is necessary for tissue growth. Adipogenesis of the isolated ASCs is induced for 3-4 days in growth medium containing Dexamethasone, Indomethacin, and 3-isobuytl-1-methylxanthine (IBMX)[10],[11]. The cells are then combined with the microspheres for a few hours and subsequently injected subcutaneously in a nude mouse model for testing. Early in vitro experiments comparing the growth and differentiation of the cells on the NF-SMS against enclosed nanofibrous hollow microspheres as a control show increased cell attachment and integration on the NF-SMS. The cells on the NF-SMS also showed greater Nile Red lipid staining and overall positive results in vitro. Current in vivo experiments are being done and are incorporating poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with insulin for sustained released of insulin from these particles during the early period of growth (1-2 weeks). Insulin appears to be very critical in the adipogenesis pathway and should be crucial in helping to produce substantial tissue in vivo[12]-[14]. These PLGA nanoparticles are injected along with the microsphere-cell complexes. Having a patient regenerate adipose tissue from their own pre-adipocyte cells will be advantageous because it eliminates the need for something foreign in the body and multiple invasive surgeries. Ensuring that the adipose tissue produced does not resorb as is the case in previous research attempts would be done by functionalizing the microsphere scaffolds with an angiogenic factor, which is the next goal of this project.

长期施肥对双季稻田土壤微生物学特性的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 长期施肥对双季稻田土壤微生物学特性的影响 DOI: 10.5846/stxb201504080708 作者: 作者单位: 湖南生物机电职业技术学院,湖南省土壤肥料研究所,湖南省土壤肥料研究所,湖南省土壤肥料研究所,湖南省土壤肥料研究所,湖南省土壤肥料研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目（31201178，31571591）；湖湘青年科技创新创业平台资助项目 Effects of different long-term fertilization regimes on the soil microbiological properties of a paddy field Author: Affiliation: College of Biological and Electromechanical Polytechnic,Hunan Soil and Fertilizer Institute,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为探明不同施肥处理对早稻和晚稻各个生育时期稻田土壤微生物生物量碳、氮和微生物熵的影响，以湖南宁乡长期定位试验为平台，应用氯仿熏蒸-K2SO4提取法和化学分析法系统分析了定位长达29年5种施肥处理之间（化肥、秸秆还田+化肥、30%有机肥+70%化肥、60%有机肥+40%化肥和无肥）双季稻田土壤微生物生物量碳、氮和微生物熵的差异。结果表明，早稻和晚稻各主要生育时期，长期施肥均能提高土壤微生物生物量碳、氮含量和微生物熵，各施肥处理土壤微生物生物量碳、氮含量和微生物熵均随水稻生育期推进呈先增加后降低的变化趋势，均于齐穗期达到最大值，成熟期达到最低值；其中，以60%有机肥和30%有机肥处理双季稻田土壤微生物生物量碳、氮含量和微生物熵均为最高，均显著高于其他处理，其大小顺序表现为60%有机肥 > 30%有机肥 > 秸秆还田 > 化肥 > 无肥。长期有机无机配施可以提高土壤微生物生物量碳、氮和微生物熵，有机肥与化肥配施对提高土壤肥力效果最好。土壤微生物生物量碳、氮及微生物熵可以反映土壤质量的变化，可作为评价土壤肥力的生物学指标。 Abstract:Fertilization regimes affect the soil microbiological properties of paddy fields. In China, few studies have investigated the influence of long-term fertilizer and combined organic matter and fertilizer application on the soil's microbiological properties. Our objective was to explore the characteristics of soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), and the soil microbial quotient of a paddy field during the early and late rice growth periods under different long-term fertilization regimes in a double cropping rice system. A long-term experiment was established in 1986 in Ningxiang county of Hunan Province, China, and five different fertilizer treatments were applied:(1) no fertilizer input (CK), (2) mineral fertilizer alone (MF), (3) rice residue plus mineral fertilizer (RF), (4) 30% organic matter and 70% mineral fertilizer (OM1), and (5) 60% organic matter and 40% mineral fertilizer (OM2). We analyzed the SMBC, SMBN, and soil microbial quotient of the fields with the above five treatments using the fumigation-extraction and chemical analysis methods. The results showed that after 29 years, the different fertilization regimes significantly affected the soil's chemical and microbial properties. Compared to the CK, the organic matter, total N, and available N, P, and K increased due to the combined application of chemical fertilizer, recycled rice straw, and chicken manure. In paddy fields, the SMBC activity, SMBN, and soil microbial quotient were increased by long-term fertilization regimes wherein applications were carried out during the early and late rice growth periods. Meanwhile, the SMBC activity, SMBN, and soil microbial quotient increased with the development of early and late rice, peaking at the heading stages of early and late rice. These measurements then reached their minimum value at the mature stages of early and late rice. Compared to the CK, the SMBN activity increased by 7.67%, 10.98%, 19.17%, and 21.75% when treated with MF, RF, OM1, or OM2, respectively, at the heading stage of early rice, and increased by 7.27%, 10.41%, 18.18%, and 20.14% when treated with MF, RF, OM1, or OM2 at the heading stage of late rice, respectively. Furthermore, the SMBC activity, SMBN, and the soil microbial quotient were significantly higher when treated with OM1 or OM2 than that in the MF, RF, or CK treatments at the different main growth stages of early and late rice, respectively. In addition, the SMBC activity, SMBN, and soil microbial quotient under different fertilization regimes were ordered as follows:OM2 > OM1 > RF > MF > CK at the main growth stages of early and late rice. The soil fertility was increased by the combined application of mineral fertilizer and organic matter, and the SMBC activity, SMBN, and soil microbial quotient were correlated with combined long-term fertilizer and organic matter application. Therefore, the combined application of chemical fertilizer and recycled rice straw or chicken manure could significantly increase the SMBC activity, SMBN, and soil microbial quotient of paddy fields during early and late rice growth. In addition, the soil microbial properties reflect changes in soil quality, such as the SMBC activity, SMBN, and soil microbial quotient, all of which can be used as biological indicators for the evaluation of soil fertility. 参考文献 相似文献 引证文献

Habitat use and growth of the western painted crayfish Orconectes palmeri longimanus (Faxon, 1898) (Decapoda: Cambaridae)

Identifying ontogenetic shifts in habitat use by aquatic organisms is necessary for improving conservation strategies; however, our ability to designate life stages based on surrogate metrics (i.e., length) is questionable without validation. This study identified growth patterns of age-0 western painted crayfish Orconectes palmeri longimanus (Faxon, 1898) reared in the laboratory, provided support for field-based designations of age-0 lengths, and identified microhabitat factors important to adult and juvenile presence from field collections. Two growth periods of a laboratory crayfish population were described using a broken line model: a rapid, early-growth period (weeks 2-20, slope = 0.81 ± 0.03SE), and a slower, late-growth period (weeks 22-50, slope = 0.13 ± 0.03SE). A smoothed curve was generated to represent the size distribution of juveniles from our laboratory population to determine the probability that an age-0 crayfish from our laboratory population had a carapace length (CL) similar to that found in previous field studies using onset of maturity (22.4 mm CL). We determined that the probability of the age-0 crayfish in our summer laboratory population exceeding 22.4 mm CL was 0.06. The threshold between the lower 0.95 and upper 0.05 probabilities was 22.9 mm CL, confirming previous field observations of onset at maturity. We used this threshold to identify juveniles and adults from our field collections, and found that both life stages were positively associated with coarse substrate and negatively associated with water depth. Adults, however, were negatively related to gravel, whereas juveniles showed a positive relationship. This result is reflective of the relationship between crayfish body size and refuge use within the interstitial spaces of substrates, whereby adult crayfish are unable to seek refuge in the small interstitial spaces of gravel.

北方典型农牧交错带草地开垦对地表辐射收支与水热平衡的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 北方典型农牧交错带草地开垦对地表辐射收支与水热平衡的影响 DOI: 10.5846/stxb201507131484 作者: 作者单位: 中国科学院地理科学与资源研究所陆地表层格局与模拟重点实验室;内蒙古师范大学,中国科学院地理科学与资源研究所陆地表层格局与模拟重点实验室,中国科学院地理科学与资源研究所陆地表层格局与模拟重点实验室,中国科学院地理科学与资源研究所陆地表层格局与模拟重点实验室,内蒙古师范大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（41371409）；国家科技支撑计划项目（2013BAC03B04）；国家重大科学研究计划（973）项目（2010CB950902） Impacts of grassland reclamation on land surface radiation and water-heat fluxes in the farming-pastoral ecotone of northern China Author: Affiliation: Institute of Geographic Sciences and Natural Resources Research; Inner Mongolia Normal University,Institute of Geographic Sciences and Natural Resources Research,Institute of Geographic Sciences and Natural Resources Research,Institute of Geographic Sciences and Natural Resources Research, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以北方典型农牧交错带草原和农田生态系统的涡度相关数据为基础，对比分析了生长季两种不同土地利用类型的辐射和水热通量之异同，揭示了草地开垦影响地表辐射收支与水热平衡的机制。结果表明：在植被生长季（5月-9月），草地开垦引起太阳总辐射增加了10.74%，短波反射辐射减少了14.20%，净辐射增加了35.16%；在水热通量方面，草地开垦引起潜热通量日积分平均值增加了0.20 MJ/m2，同时显热通量减少了0.09 MJ/m2；生长季内地表反照率减小，表征地表吸收太阳辐射增加，有升高气温的趋势；非生长季内地表反照率增加，有降低气温趋势，此外地表反照率与土壤湿度存在负指数关系；波文比在植被生长早期和末期增加，生长旺期减小，说明草地开垦与影响着近地表大气状态，从而改变了区域气候。 Abstract:We compared land surface radiation and water-heat flux of two different land use types using eddy covariance flux data of typical grassland and cropland ecosystems in a farming-pastoral ecotone of northern China. The comparisons revealed that the biophysical mechanisms of grassland reclamation affected the surface radiation flux budget and the water-heat flux balance. The results further showed that, during the growing season (May-September), grassland reclamation increased the solar radiation by 10.74%, reduced the shortwave reflected radiation by 14.20%, and increased the net radiation by 35.16%. As for the water-heat flux, grassland reclamation increased the latent heat flux 0.20 MJ/m2, whereas the sensible heat flux was reduced by 0.09 MJ/m2. The surface albedo decreased during the growing season, which was illustrated by the surface that absorbed more solar radiation and had a tendency to rise in the temperature. In contrast, the albedo increased during non-growing season, which was illustrated by a decrease in the temperature; in addition, a negative exponential relationship between surface albedo and soil moisture was observed. The Bowen ratio in the early and late vegetation growth period increased and decreased dramatically during these growing stages. Finally, the grassland reclamation affected the near-surface atmospheric conditions, which consequently changed the regional climate. 参考文献 相似文献 引证文献

Growth performance of male broilers fed diets varying in digestible threonine to lysine ratio from 1 to 14 days of age

Summary Threonine (Thr) is the third limiting amino acid for broilers fed corn-soybean meal–based diets. Digestible Thr to lysine (Lys) ratios utilized by commercial nutritionists vary from 0.63 to 0.68 in the starter period. Low Thr to Lys ratios used during the early growth period can limit performance. This study examined growth responses of broilers provided experimental diets varying in digestible Thr from 1 to 14 d of age. Dietary treatments were formulated at 8 digestible Thr to Lys ratios (0.55, 0.58, 0.61, 0.64, 0.67, 0.70, 0.73, and 0.76). Two diets (dilution and summit) consisting of corn and soybean meal were formulated to be adequate in all other amino acids with the exception of Thr and Lys. All diets were formulated to contain 1.13% digestible Lys, which is slightly below the digestible Lys requirement for male broilers from 1 to 14 d of age. Digestible Thr to Lys ratios were estimated using broken-line methodology. Linear (P = 0.003) and quadratic (P = 0.005) increases in body weight gain (BWG) were observed for broilers fed progressive additions of digestible Thr. Additionally, linear (P

Effects of overexpression of a bHLH transcription factor on biomass and lipid production in Nannochloropsis salina.

BackgroundMicroalgae are considered promising alternative energy sources because they consume CO2 and accumulate large amounts of lipids that can be used as biofuel. Nannochloropsis is a particularly promising microalga due to its high growth rate and lipid content, and the availability of genomic information. Transcription factors (TFs) are global regulators of biological pathways by up- or down-regulation of related genes. Among these, basic helix-loop-helix (bHLH) TFs regulate growth, development, and stress responses in plants and animals, and have been identified in microalgae. We identified two bHLH TFs in the genome of N. salina CCMP1776, NsbHLH1, and NsbHLH2, and characterized functions of NsbHLH2 that may be involved in growth and nutrient uptake.ResultsWe obtained NsbHLH2 overexpressing transformants of N. salina CCMP1776 by particle bombardment and confirmed that these were stable transformants. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting using antibodies against the FLAG tag that was attached at the end of the coding sequence confirmed the expression of the NsbHLH2 protein under various culture conditions. The qRT-PCR results also indicated that the endogenous and transgenic expression of NsbHLH2 was reduced under stressed conditions. Overexpression of NsbHLH2 led to increased growth rate in the early growth period, and concomitantly higher nutrient uptake, than wild type (WT). These enhanced growth and nutrient uptake resulted in increased productivities of biomass and FAME. For example, one of the transformants, NsbHLH2 3–6, showed increased biomass productivity by 36 % under the normal condition, and FAME productivity by 33 % under nitrogen limitation condition. Conclusively, the improved growth in the transformants can be associated with the enhanced nutrient uptake. We are currently assessing their potential for scale-up cultivation with positive outcomes.ConclusionOverexpression of NsbHLH2 led to enhanced growth rate and nutrient uptake during the early growth phase, and increased biomass and FAME productivity, especially in the later period under normal and stressed conditions. Based on these results, we postulate that NsbHLH2 can be employed for the industrial production of biodiesel from N. salina.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-015-0386-9) contains supplementary material, which is available to authorized users.

Fly ash and zeolite amendments increase soil nutrient retention but decrease paddy rice growth in a low fertility soil

Fly ash (FA) and zeolite (Z) are known to increase nutrient retention in paddy soils through the immobilization of phosphorus (P) by FA and nitrogen (N) by Z. However, there is a possibility that the co-application of the amendments may hamper rice growth due to reduced availability of the nutrients. This study was conducted to investigate the effects of the co-application of FA and Z on soil N and P availability and rice growth. Rice was cultivated in soils without the amendment (control) and with the amendment: FA alone, Z alone, and both FA and Z. Tiller number, dry matter (DM), rice uptake of N and P, and soil N and P concentrations were determined. The application of FA and Z increased N and P concentrations in the soils; however, such increased nutrient retention did not translate to DM increases. Results suggested that reduced mobility of nutrients hampered tillering in the early growth period, eventually leading to a reduction in DM accumulation at the harvest. Due to the nutrient limitation caused by FA and Z, the rice grown with both FA and Z did not survive at the harvest. Our study shows that the application of FA and Z does not always improve rice growth due to nutrient limitation, especially in a low fertility soil. Furthermore, the co-application of FA and Z should be avoided, as the negative impact of FA or Z on nutrient limitation became more severe when FA and Z were co-amended.

Evaluation of the tolerance of Thai indigenous upland rice germplasm to early drought stress using multiple selection criteria

Drought remains the most important factor that affects rice productivity, especially in rainfed areas, worldwide. Upland rice is one of the crop choices of farmers in the rainfed environment. Although upland rice varieties require less water than lowland rice varieties, yields often remain limited by drought, particularly in the period of early growth. The aims of this study were to identify the traits related to early drought tolerance in upland rice varieties, and to identify the potential sources of germplasm for early drought tolerance. A total of sixty upland rice varieties were planted in a factorial experiment with a randomized complete block design with 3 replications in the rainy seasons of 2011 and 2012, under greenhouse conditions. Based on the drought tolerance index (DTI), the test germplasm sources were classified into three groups: (i) susceptible; (ii) moderately tolerant; (iii) tolerant to drought stress. Grain yield (GY) showed significant negative correlations with the leaf rolling score (r= − 0.623, P< 0.01), the leaf death score (LDS) (r= − 0.673, P< 0.01) and the recovery score (r= − 0.746, P< 0.01), while leaf dry matter (r= 0.698, P< 0.01) and leaf water potential (r= 0.618, P< 0.01) had significant positive correlations with GY. These findings indicate the suitability of the DTI as the selection criteria for early drought tolerance in a breeding programme. In addition, the upland rice germplasm accessions KKU-ULR011, KKU-ULR012, KKU-ULR125, KKU-ULR199 and KKU-ULR292 were identified as having high levels of stability for drought tolerance in both the 2011 and 2012 experiments, suggesting their potential for further use for rice variety improvement for drought tolerance.

Analysis of Conveyance Environment and Pre-treatment on Quality Maintenance of Cut Dendranthema grandiflorum ‘Baekma’ during Ship Export to Japan

본 연구는 절화 국화 'Baekma'를 일본으로 선박 수출 시 수송 환경을 분석하였으며, 절화 국화의 선도를 유지하기 위한 최적 전처리제를 구명하고자 하였다. 그 결과 일본으로 절화 국화를 수출시 약 3일~5일이 소요되었으며, 국내 이동, 선박 운송 및 일본 내에서 이동은 저온이 유지되었으나, 일본에서 검역시 상온에 노출되는 것으로 조사되었다. 이는 품질의 손상을 야기하는 것으로 수송 전체 기간동안 저온조건을 유지해야 할 것으로 판단되었다. 또한, 전처리제는 Chrysal RVB, NaOCl 처리구가 절화수명 연장에 효과적이었으며, Chrysal RVB 전처리는 절화 국화가 끝까지 만개하여 화형이 유지되었다. 박테리아 검정 결과 NaOCl, <TEX>$ClO_2$</TEX> 처리구의 박테리아가 검출되지 않아 살균 성분이 세균증식을 막아준 것으로 판단되었다. 그러나 <TEX>$ClO_2$</TEX>처리구는 수확 후 초기 생육에 영향을 미치는 것으로 사료되었다. Chrysal RVB 처리 및 NaOCl 처리구의 엽록소 함유량이 가장 높은 것으로 조사되었다. This study was carried out to investigate conveyance environment during shipping export to Japan and the optimum pre-treatment of cut Dendranthema grandiflorum 'Baekma'. Shipping from Korea to Japan, which usually takes three to five days, requires keeping the flower at the ideal temperature. When inspection took place in Japan, the ideal temperature was lost and deterioration began. Once the ideal temperature is lost, deterioration takes place. The results of this work showed that vase life was extended by treatment Chrysal RVB and NaOCl compared to the control (distilled water), and Chrysal RVB was used to maintain the flower from bud to full bloom. Bacterial growth was not observed after pretreatment with NaOCl or <TEX>$ClO_2$</TEX>. However, <TEX>$ClO_2$</TEX> pre-treatment was observed to affect the early growth period of the bacteria. The chlorophyll content was the highest after Chrysal RVB or NaOCl pretreatment compared to the other treatments. Therefore, these results support pretreatment with NaOCl and Chrysal RVB of Dendranthema grandiflorum 'Baekma' for export to Japan.

Effects of Different Soil Texture on Peanut Growth and Development

The effects of different soil textures (namely sand, loam, and clay) on peanut growth and development were investigated using the carton planting method. The results showed that sand is conducive to the growth of stems and leaves of peanuts in the early growth period, loam is conducive to the growth of stems and leaves in the middle and late periods, and clay is not conducive to the growth of stems and leaves of peanuts throughout the entire growth period. Soil texture had a significant effect on the number of peanut flowers. This is because the amount of flowering peanuts was insufficient in the clay. Although the amount of flowering peanuts was large in the sand, the peanuts mainly flowered in the late period, and there was a large amount of fruitless flowers. In the loam, the peanuts mainly flowered in the early period, and there was a large amount of fruitful flowers. The difference in the total number of pegs between the sand and loam was not significant, but either had more pegs than when grown in clay. Peanuts accumulated pod dry matter quickly in the sand early in the season, but pod growth slowed later in the season. The pod dry matter in the loam was accumulated mostly in the middle and late periods. Clay was not conducive to pod dry-matter accumulation. The moderate aeration and water and fertility retention of the loam was more suitable for peanut growth and development, as well as yield formation.

Dietary vitamin A restriction affects adipocyte differentiation and fatty acid composition of intramuscular fat in Iberian pigs

The aim of this study was to investigate whether dietary vitamin A level is associated with differences in adipocyte differentiation or lipid accumulation in Iberian pigs at early growing (35.8kg live weight) and at finishing (158kg live weight). Iberian pigs of 16.3kg live weight were allocated to two feeding groups, one group received 10,000IU of vitamin A/kg diet (control); the other group received a diet with 0IU of vitamin A (var) for the whole experimental period. The dietary vitamin A level had no effect on growth performance and carcass traits. The early suppression of vitamin A increased the preadipocyte number in Longissimus thoracis (LT) muscle in the early growth period (P<0.001) and the neutral lipid content and composition (higher MUFA and lower SFA content) at the end of the finishing period (P<0.05). Vitamin A restriction in young pigs increases their lipogenic potential without affecting carcass traits.

Effects of winter covering crop residue incorporation on CH₄ and N₂O emission from double-cropped paddy fields in southern China.

Residue management in cropping systems is useful to improve soil quality. However, the studies on the effects of residue management on methane (CH4) and nitrous oxide (N2O) emission from paddy field in southern China are few. Therefore, the emissions of CH4 and N2O were investigated in double cropping rice (Oryza sativa L.) systems with different winter covering crops using the static chamber-gas chromatography technique to assess the effects of different covering crops on the emissions of greenhouse gases. The experiment was established in 2004 in Hunan Province, China. Three winter cropping systems were used: rice–rice–rape (Brassica napus L.) (T1), rice–rice–potato with straw mulching (Solanum tuberosum L.) (T2), and rice–rice with winter fallow (CK). A randomized block design was adopted in plots, with three replications. The results showed that T2 plots had the largest CH4 emissions during the early and late rice growing season with 12.506 and 32.991 g m−2, respectively. When compared to CK, total N2O emissions in the early rice growth period and the emissions of the gas increased by 0.013 g m−2 in T1 and 0.045 g m−2 in T2, respectively. Similar results were obtained in the late rice growth period; the total N2O emissions increased by 0.027 g m−2 in T1 and 0.084 g m−2 in T2, respectively. The mean value of global warming potentials (GWPs) of CH4 and N2O emissions over 100 years was in the order of T2 > T1 > CK, which indicated CK and T1 was significantly lower than T2 (P < 0.05). This suggests that adoption of T1 would be beneficial for greenhouse gas emission mitigation and could be a good option cropping pattern in double rice cropped regions.

The major aliphatic glucosinolate content in Korean radish during vegetative and reproductive growth

Glucosinolates (GSLs) are secondary metabolites abundant in Brassica vegetables and the interest on this compound has been grown due to their health benefits. The amounts of major aliphatic GSLs, glucoraphasatin (GRH), and glucoraphenin (GRE) were measured in five radish cultivars during their vegetative and reproductive growth. The GRE content was higher in seed (ranging from 16.5 to 19.4 mg·g−1 dry weight) than that of leaves or roots in all five genotypes. The GRE content sharply declined during germination and remained stable at the basal level for the subsequent vegetative growth period. In contrast, the amount of GRH, an immediate precursor of the GRE, steadily increased during the early growth period up to 8 weeks and remained at a similar level thereafter. As growth of seedlings progressed, the inner leaves contained higher amounts of GRH than the outer leaves. In roots, smaller amounts of GRE were found, as compared to other tissues. However, the GRH was abundant in roots and mature inner leaves. The GRE tended to accumulate in reproductive organs, while GRH was found primarily in the roots and the inner leaves at the mature stage.

Bridging the gaps: An early integrated support collaborative for at risk mothers in rural Maine.

The antecedents that contribute to health disparities in maternal child health populations begin before birth and extend into the early prenatal and gestational growth periods. Mothers and infants living in rural poverty in particular are at considerable risk for problems associated with reproductive health, including pregnancy complications and premature births. The aim of this manuscript is thus two-fold, to describe the epidemiologic makeup of the community and the intervention model of the Community Caring Collaborative. Innovative models of early-integrated care for high-risk mothers and children are showing promise for long-term outcomes. They foster environments that enable mothers to trust health systems while maintaining a workforce of high functioning health workers who understand the mechanisms that underpin maternal and child health disparities. The Community Caring Collaborative in Washington County, Maine developed one such model that has made inroads in bridging such gaps. This manuscript explicates a case study of how the Community Caring Collaborative came into being and why it established the Bridging model of comprehensive care. The focus of this manuscript is thus two-fold, the community and the intervention model. The "bridging model" develops trust-based relationships between high-risk mothers with the health system and its multiple resources. Community members with advanced training provide the support and care linkages that are critical for family success. Innovative models of collaborative care impact the health of vulnerable mothers and their children working toward a marked decrease in health related disparities.

Accumulation and speciation of selenium in Cardamine sp. in Yutangba Se Mining Field, Enshi, China

A naturally selenium-accumulating Cardamine sp. is growing in Yutangba Selenium Mining Field, Enshi area, Hubei Province, China, where the geochemical environment is selenium-enriched and endemic selenosis ever occurred in humans. The present study investigated the characteristics of accumulation, speciation and quantity of selenium in Cardamine sp. with HPLC-ICP-MS. Results show that Cardamine sp. can accumulate Se at most 1427 mg/kg in seedling leaves. Even after the biomass incensement of growing up, the plant still could accumulate Se up to several hundred of mg/kg in concentration. Moreover, the biomass enrichment coefficient (BEC) of Se is exceedingly high, in the seedling leaves mostly, higher than 50 mg/kg; in the range of 43.7–68 mg/kg; and the lowest value is higher than 3 mg/kg in mature fronds. Se is present in the plant predominantly in form of SeCys2 with the highest concentration in seeds; up to 1081 mg/kg as Se. In contrast, SeCys2 levels are low during early growth period; they are 136.1 mg/kg as Se in seedling fronds and 39.4 mg/kg as Se in mature fronds, respectively. SeMet concentration is comparatively low; 10.6 mg/kg as Se in seedling frond and 5.3 mg/kg as Se in half mature fronds, respectively. This indicates that Cardamine sp. is extremely efficient in extracting Se from soil and translocating it into its above-ground biomass. Therefore, Cardamine sp., found in Yutangba Se Mining Field may be a new Se hyperaccumulator. It is still uncertain whether the Se-accumulation or detoxification of Cardamine sp. happens through the pathway of SeCys methylated to form Se-methylselenoCys or through the formation of Se-carboxymethyl-selenohomocysteine. Indeed, further study should be carried out on the determination of more Se species to explain the high Se hyperaccumulation in Cardamine sp.

Sustained costs of growth and the trajectory of recovery

Summary Large body size is associated with many fitness advantages. Despite this, most species do not grow at their physiological maximum, suggesting costs to rapid growth. There are now many empirical examples of trade‐offs with growth. Despite the ubiquity of physiological delays, few studies have evaluated the duration over which growth costs occur. To address this question, we measured swimming ability in growth‐manipulated Atlantic silversides (Menidia menidia). Fish were manipulated to grow at their maximum for 2 weeks and then were put on restricted rations, so they grew slowly. We then compared swimming ability with fish that had always grown slowly. Fast‐grown fish had significantly poorer swimming ability and continued to show a prolonged cost of this early period of rapid growth. We found that fish fully recovered normal swimming ability after ˜1 month of growing slowly. Most surprisingly, the trajectory of recovery was not monotonic; performance actually decreased before it improved. We conclude with a suggestion to develop a better understanding of the mechanisms linking growth to performance trade‐offs. Our results suggest that reduced swimming performance following fast growth is unlikely to be completely explained by bioenergetic constraints. Additionally, there is need for more nuanced life‐history theory that incorporates prolonged growth costs to increase accuracy of growth rate prediction.

Proteus mirabilis alleviates zinc toxicity by preventing oxidative stress in maize (Zea mays) plants

Plant-associated bacteria can have beneficial effects on the growth and health of their host. However, the role of plant growth promoting bacteria (PGPR), under metal stress, has not been widely investigated. The present study investigated the possible mandatory role of plant growth promoting rhizobacteria in protecting plants from zinc (Zn) toxicity. The exposure of maize plants to 50µM zinc inhibited biomass production, decreased chlorophyll, total soluble protein and strongly increased accumulation of Zn in both root and shoot. Similarly, Zn enhanced hydrogen peroxide, electrolyte leakage and lipid peroxidation as indicated by malondaldehyde accumulation. Pre-soaking with novel Zn tolerant bacterial strain Proteus mirabilis (ZK1) isolated zinc (Zn) contaminated soil, alleviated the negative effect of Zn on growth and led to a decrease in oxidative injuries caused by Zn. Furthermore, strain ZK1 significantly enhanced the activities of catalase, guaiacol peroxidase, superoxide dismutase and ascorbic acid but lowered the Proline accumulation in Zn stressed plants. The results suggested that the inoculation of Zea mays plants with P. mirabilis during an earlier growth period could be related to its plant growth promoting activities and avoidance of cumulative damage upon exposure to Zn, thus reducing the negative consequences of oxidative stress caused by heavy metal toxicity.

Production of dimethylsulfide and acrylic acid from dimethylsulfoniopropionate during growth of three marine microalgae

We measured the concentrations of dimethylsulfide (DMS), acrylic acid (AA), and dimethylsulfoniopropionate (DMSP) during growth of three microalgae: Prorocentrum micans, Gephyrocapsa oceanica, and Platymonas subcordiformis. The DMSP, AA, and DMS concentrations in culture media varied significantly among algal growth stages, with the highest concentrations in the late stationary growth stage or the senescent stage. In the stationary growth stage, the average DMSP concentration per cell in P. micans (0.066 5 pmol/cell) was 1.3 times that in G. oceanica (0.049 5 pmol/cell) and 20.2 times that in P. subcordiformis (0.003 29 pmol/cell). The average concentrations of AA were 0.044 6, 0.026 9, and 0.003 05 pmol/cell in P. micans, G. oceanica, and P. subcordiformi s, respectively, higher than the concentrations of DMS (0.272, 0.497, and 0.086 2 fmol/cell, respectively). There were significant positive correlations between cell density and AA, DMSP, and DMS concentrations. The ratios of DMS/AA and AA/(DMSP+AA) in the three algae differed significantly over the growth cycle. In all three microalgae, the DMS/AA ratios were less than 25% during the growth period, suggesting that the enzymatic cleavage pathway, which generates DMS, was not the main DMSP degradation pathway. The changes in the DMS/AA ratio indicated that there was a higher rate of enzymatic breakdown of DMSP in the early growth period and a lower rate during senescence. In all three microalgae, the AA/(DMSP+AA) ratio (degradation ratio of DMSP) decreased during the exponential growth phase, and then increased. The variations in these ratios can approximately indicate the cleavage mechanism of DMSP at different stages of algal growth.

Seasonal Performance and Spatial Heterogeneity of Soil Salt Ions in a Semiarid Orchard of Northwest China

The relationship between spatial and temporal dynamics of major salt ions and their toxicology is still unclear, particularly in perennial orchard fields. A seasonal soil sampling was conducted from Apr. to Oct. 2011 in a salinized orchard soil in semiarid northwest China. Soil moisture content and concentrations of total soluble salt and eight salt ions were measured every 2 weeks in the soil at 0 to 2, 2 to 5, 5 to 10, 10 to 15, 15 to 20, 20 to 25, 25 to 40, 40 to 60, 60 to 80, and 80 to 120 cm during the growing period of apple trees. Soil moisture content decreased early in the growth season (Period 1) but with increasing rainfall in the middle of growing season (Period 2 and Period 3) and reached a maximum at late season (Period 4) at all depths. Soil salt concentration increased along with soil profile, particularly in the 60- to 120-cm soil layer at all periods. The highest soil salt level was observed in Period 4. The contents of HCO3–, Ca2+, and Mg2+ were almost uniform in all soil layers, but the contents of Cl–, SO42–, and Na+ increased with soil layer. The content of K+ decreased from the upper to the deeper layers of soil profile. The distribution of CO32– had a high temporal and spatial heterogeneity with soil depths and season. Analysis of the charge balance on positive and negative salt ions indicated that the horizontal movement of ions and the transfer of soil water were likely the driving factors affecting soil salinization. The movement of Na+ and Mg2+ ions in the top soil may be responsible for rhizospheric ions composition and toxin effect to restrain apple tree growth in the early growth period.

Deficit irrigation scheduling and yield prediction of ‘Kinnow’ mandarin (Citrus reticulate Blanco) in a semiarid region

Scarcity of irrigation water in critical growth stages of the crop is one of the major causes of low productivity and decline of citrus orchards. Regulated deficit irrigation (RDI) is a recently proposed water saving technique in irrigated agriculture. The present study was planned with a hypothesis that the optimal RDI scheduling at early fruit growth period (EFGP), which coincides with summer months could save substantial amount of water, without significantly affecting the yield of ‘Kinnow’ mandarin (Citrus reticulata Blanco) plants. Two DI strategies: (a) withholding irrigation at EFGP (RDI0) and (b) irrigation at 50% crop evapotranspiration (ETc) at EFGP (RDI50) were compared with full irrigation (FI, 100% ETc) in relation to gas exchange, water relation and nutrient composition of leaves along with growth and yield of the plants. The greater plant growth with maximum fruit yield (61.9–63.2tha−1) was recorded with fully-irrigated plants. However, the yield under RDI50 was statistically (p>0.05) at par with that under FI. The reduction in water application of around 24% with RDI50 resulted in 30% improvement in irrigation water use efficiency with this treatment over that with FI. The maximum rate of net-photosynthesis, stomatal conductance and transpiration of leaves was recorded with fully-irrigated plants. However, the plants under RDI50 exhibited the highest leaf water use efficiency. The leaf nutrients (N, P, K, Fe, Mn, Cu and Zn) analysis revealed that RDI0 produced significantly (p<0.05) lower concentration of all the nutrients except P and Cu than that in other treatments. Relative leaf water content (RLWC), leaf water concentration (LWC) and mid-day stem water potential (Ψ) showed a decreasing trend, whereas water stress integral (SΨ) and plant canopy reflectance indices (water band index, WBI; normalised difference water index, NDWI; and moisture stress index, MSI) showed the reverse trend of RLWC with water stress. The prediction model formulated based on midday stem water stress integral, leaf N, leaf K, stomatal conductance and water stress index using Principal component regression technique during EFGP performed well with reasonably accuracy (R2=0.85) to forecast annual fruit yield of the citrus plants. Overall, these results reveal that irrigation at 50% ETc during EFGP could impose desirable water stress on ‘Kinnow’ mandarin plants, improving their water use efficiency, without significantly affecting the fruit yield under water scarce condition.