Manipulation Treatments Research Articles

氮肥添加对高寒藏嵩草(Kobresia tibetica)沼泽化草甸和土壤微生物群落的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 氮肥添加对高寒藏嵩草(Kobresia tibetica)沼泽化草甸和土壤微生物群落的影响 DOI: 10.5846/stxb201508041642 作者: 作者单位: 西南民族大学生命科学与技术学院;中国科学院水利部成都山地灾害与环境研究所;中国科学院成都生物所,中国科学院水利部成都山地灾害与环境研究所,中国科学院成都生物所,西南民族大学生命科学与技术学院,西南民族大学生命科学与技术学院,西南民族大学生命科学与技术学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点基础研究发展计划（973计划）（2013CBA01807）；国家自然科学基金项目（31370542）；中央高校基本科研业务费优秀科研团队及重大孵化项目（2014NZYTDO1） Effects of N addition on the plant and soil microbial community in alpine Kobresia tibetica meadow of Qinghai-Tibet Plateau Author: Affiliation: College of Life Science and Technology,Southwest University for Nationalities,,,,, 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:以藏嵩草沼泽化草甸为研究对象，利用磷脂脂肪酸（PLFA）技术，研究连续6年N素添加对地上植被群落数量特征、土壤微生物群落结构的影响。结果表明：①藏嵩草沼泽化草甸群落生物量、枯枝落叶对施肥处理无明显响应，且莎草科植物对土壤氮素的吸收和利用率较低。②施肥增加了0-10 cm土壤微生物类群PLFAs丰富度，尤其细菌和革兰氏阳性菌PLFAs，降低了10-20 cm PLFAs丰富度；③磷脂脂肪酸饱和脂肪酸/单烯不饱和脂肪酸、细菌PLFAs/真菌PLFAs的比值随土壤层次增加而增加；④ 0-10 cm土层，革兰氏阳性菌、真菌PLFAs含量与pH、土壤速效磷、速效氮、土壤有机质显著正相关（P < 0.05或P < 0.01）；10-20 cm土层，细菌、革兰氏阳性菌、真菌和总PLFAs含量与土壤有机质含量显著正相关（P < 0.05或P < 0.01）。表明藏嵩草沼泽化草甸微生物PLFAs含量和丰富度对施肥的响应存在明显的土层梯度效应，土壤微生物PLFAs含量和丰富度主要受表层土壤初始养分含量的影响。 Abstract:Effects of continuous six-year N addition on the quantitative properties of plant and soil microbial communities in alpine Kobresia tibetica meadows were investigated experimentally by using field surveys and phospholipid fatty acid (PLFA) analyses. The experiment included four manipulative treatments involving both N and litter:added N (+N) with the litter removed (LR), +N with the litter left intact (LI), LI without N addition (-N), and LR with -N. Soil samples were collected at the depths of 0-10 and 10-20 cm. Aboveground biomass (AGB), litter biomass, microbial community composition, and nutrient content were measured. The results showed that (1) fertilization did not have significant effects on AGB and litter biomass. (2) N addition significantly increased the abundance of the microbial group PLFAs at the soil depth of 0-10 cm, particularly the abundance of the bacterial PLFAs (B PLFAs) and gram-positive bacterial PLFAs (G+ PLFAs), but decreased microbial abundances at the soil depth of 10-20 cm. (3) The ratio of the normal saturated fatty acids/monounsaturated fatty acids and B PLFAs/fungal PLFAs (F PLFAs) increased with the increase in the soil depth. (4) G+ PLFA and F PLFA contents were significantly and positively correlated to pH, available phosphorus, available nitrogen, and soil organic matter contents at 0-10 cm soil depth. The contents and abundance of fatty acids were mainly regulated and affected by initial nutrient level in the topsoil after short-term N addition. These results indicate that microbial communities in this alpine tundra are sensitive to both litter and N inputs, and that the vertical structures of these communities are particularly vulnerable. 参考文献 相似文献 引证文献

Effect of Embryo Thermal Stimulation on the Serum Levels of Immunoglobulins and Corticosterone, and Organ Histopathology of 1 day-old Broilers

Embryo thermal stimulation has been studied as a means to promote epigenetic changes and to improve broiler health and performance. This study aimed at evaluating immunoglobulin (IgM, IgG, and IgA) titers, serum corticosterone levels, and organ integrity of day-old male Cobb(r) and Ross(r) broilers. Embryos were submitted to hot and cold stimuli (thermal stimulation) on days 14-18 of incubation. The thermal manipulation treatments did not affect immunoglobulin titers of 1 day-old Cobb(r) or Ross(r) chicks, and caused severe bursal lesions (scores 3 and 4) in both strains. However, serum corticosterone levels of Cobb(r) chicks were higher when embryos were submitted to hot stimulus (+1.39oC) compared with cold stimulus (+36 oC). Serum corticosterone levels of Ross(r) chicks were not affected by embryo temperature manipulation. The only effect of broiler breeder age was observed on IgM titers of Cobb(r) chicks, which were higher in chicks from 33-wk-old breeders. Further studies are needed to detect the optimal period of embryo thermal stimulation.

Development of temporomandibular joint arthritis: The use of animal models

Osteoarthritis is the most common joint disease affecting roughly one sixth of the human population. It is also the most common arthritis affecting the temporomandibular joint, often leading to severe pain and the inability to masticate. Animal models are essential to investigate the disease in part because they lend themselves to genetic manipulation and various treatments and also because of the lack of availability of human specimens from various stages of the disease. The wide range of osteoarthritis models alone are a proof of its multifactorial origin. Manipulation of collagen, cytokine, matrix metalloproteinase and small leucine-rich repeat proteoglycan genes can all have an effect on the development and persistence of arthritis. Surgical models also exist, highlighting the importance of normal anatomy and trauma. Here we review the English literature of murine models of temporomandibular joint arthritis with special attention to the genetic and molecular background of osteoarthritis.

Demographic consequences of greater clonal than sexualreproduction in Dicentra canadensis.

Clonality is a widespread life history trait in flowering plants that may be essential for population persistence, especially in environments where sexual reproduction is unpredictable. Frequent clonal reproduction, however, could hinder sexual reproduction by spatially aggregating ramets that compete with seedlings and reduce inter‐genet pollination. Nevertheless, the role of clonality in relation to variable sexual reproduction in population dynamics is often overlooked. We combined population matrix models and pollination experiments to compare the demographic contributions of clonal and sexual reproduction in three Dicentra canadensis populations, one in a well‐forested landscape and two in isolated forest remnants. We constructed stage‐based transition matrices from 3 years of census data to evaluate annual population growth rates, λ. We used loop analysis to evaluate the relative contribution of different reproductive pathways to λ. Despite strong temporal and spatial variation in seed set, populations generally showed stable growth rates. Although we detected some pollen limitation of seed set, manipulative pollination treatments did not affect population growth rates. Clonal reproduction contributed significantly more than sexual reproduction to population growth in the forest remnants. Only at the well‐forested site did sexual reproduction contribute as much as clonal reproduction to population growth. Flowering plants were more likely to transition to a smaller size class with reduced reproductive potential in the following year than similarly sized nonflowering plants, suggesting energy trade‐offs between sexual and clonal reproduction at the individual level. Seed production had negligible effects on growth and tuber production of individual plants. Our results demonstrate that clonal reproduction is vital for population persistence in a system where sexual reproduction is unpredictable. The bias toward clonality may be driven by low fitness returns for resource investment in sexual reproduction at the individual level. However, chronic failure in sexual reproduction may exacerbate the imbalance between sexual and clonal reproduction and eventually lead to irreversible loss of sex in the population.

Global patterns and predictors of stem CO2 efflux in forest ecosystems.

Stem CO2 efflux (ES) plays an important role in the carbon balance of forest ecosystems. However, its primary controls at the global scale are poorly understood and observation-based global estimates are lacking. We synthesized data from 121 published studies across global forest ecosystems and examined the relationships between annual ES and biotic and abiotic factors at individual, biome, and global scales, and developed a global gridded estimate of annual ES . We tested the following hypotheses: (1) Leaf area index (LAI) will be highly correlated with annual ES at biome and global scales; (2) there will be parallel patterns in stem and root CO2 effluxes (RA) in all forests; (3) annual ES will decline with forest age; and (4) LAI coupled with mean annual temperature (MAT) and mean annual precipitation (MAP) will be sufficient to predict annual ES across forests in different regions. Positive linear relationships were found between ES and LAI, as well as gross primary production (GPP), net primary production (NPP), wood NPP, soil CO2 efflux (RS), and RA . Annual ES was correlated with RA in temperate forests after controlling for GPP and MAT, suggesting other additional factors contributed to the relationship. Annual ES tended to decrease with stand age. Leaf area index, MAT and MAP, predicted 74% of variation in ES at global scales. Our statistical model estimated a global annual ES of 6.7 ± 1.1 Pg C yr(-1) over the period of 2000-2012 with little interannual variability. Modeled mean annual ES was 71 ± 43, 270 ± 103, and 420 ± 134 g C m(2) yr(-1) for boreal, temperate, and tropical forests, respectively. We recommend that future studies report ES at a standardized constant temperature, incorporate more manipulative treatments, such as fertilization and drought, and whenever possible, simultaneously measure both aboveground and belowground CO2 fluxes.

Evaluating the Community Land Model in a pine stand with shading manipulations and &amp;lt;sup&amp;gt;13&amp;lt;/sup&amp;gt;CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; labeling

Abstract. Carbon allocation and flow through ecosystems regulates land surface–atmosphere CO2 exchange and thus is a key, albeit uncertain, component of mechanistic models. The Partitioning in Trees and Soil (PiTS) experiment–model project tracked carbon allocation through a young Pinus taeda stand following pulse labeling with 13CO2 and two levels of shading. The field component of this project provided process-oriented data that were used to evaluate terrestrial biosphere model simulations of rapid shifts in carbon allocation and hydrological dynamics under varying environmental conditions. Here we tested the performance of the Community Land Model version 4 (CLM4) in capturing short-term carbon and water dynamics in relation to manipulative shading treatments and the timing and magnitude of carbon fluxes through various compartments of the ecosystem. When calibrated with pretreatment observations, CLM4 was capable of closely simulating stand-level biomass, transpiration, leaf-level photosynthesis, and pre-labeling 13C values. Over the 3-week treatment period, CLM4 generally reproduced the impacts of shading on soil moisture changes, relative change in stem carbon, and soil CO2 efflux rate. Transpiration under moderate shading was also simulated well by the model, but even with optimization we were not able to simulate the high levels of transpiration observed in the heavy shading treatment, suggesting that the Ball–Berry conductance model is inadequate for these conditions. The calibrated version of CLM4 gave reasonable estimates of label concentration in phloem and in soil surface CO2 after 3 weeks of shade treatment, but it lacks the mechanisms needed to track the labeling pulse through plant tissues on shorter timescales. We developed a conceptual model for photosynthate transport based on the experimental observations, and we discussed conditions under which the hypothesized mechanisms could have an important influence on model behavior in larger-scale applications. Implications for future experimental studies are described, some of which are already being implemented in follow-on studies.

Dynamic Temporal Control of Signaling-Activated Gene Regulation

Many signal transduction and gene regulatory pathways are highly dynamic resulting in temporally varying activity of signaling proteins and time varying gene expression profiles. These time varying signaling profiles are important as these can direct different cellular phenotypes. Currently, our biophysical understanding of these temporal signaling profiles is very rudimentary and relies on the genetic manipulation of specific proteins or drug treatment regimes. Although protein numbers are often manipulated over a wide dynamic range using an inducible promoter, the activity of these signaling proteins may only be manipulated by mutations or drugs. One drawback of this approach is that genetic protein modification may result in a significant interference with the function of the cell, which may cause lethal phenotypes. Another drawback is that drugs are often not available for proteins of interest or have considerable off-target effect. In order to avoid these limitations, we developed a time varying perturbation approach that utilizes time varying ligand profiles to investigate the temporal properties of signaling and gene regulatory pathways, without genetic manipulation or drug treatments. To demonstrate the feasibility of this approach, we chose to interrogate the evolutionary conserved high-osmolarity glycerol stress response pathway (HOG/p38) in S. Cerevisiae, which enables to manipulate the intensity, duration and temporal activity of the signal transduction pathway in single cells. We are able to quantify signal transduction activation, signal transduction saturation and gene expression activation thresholds at high precision and demonstrate that the signaling dynamics is proportional to the first time derivative of the external perturbation profile. Because this approach is independent of the biological pathway or organism, it presents a general methodology to interrogate and control signaling and gene expression pathways non-invasively without the need for genetic or drug perturbations.

Winter snowfall can have a positive effect on photosynthetic carbon fixation and biomass accumulation of biological soil crusts from the Gurbantunggut Desert, China

AbstractWinter snowfall is an important factor in the growth and development of biological soil crusts (BSCs) in temperate desert regions of China. In this study, intact algae, lichen, and moss crusts from the Gurbantunggut Desert were collected and exposed to five experimental treatments—snow removal (0S), snow decrease to half that of ambient conditions (1/2S), ambient snow (S), snow increase to 1.5 times that of ambient conditions (3/2S), and snow increase to twice that of ambient conditions (2S)—to evaluate the effect of snowfall on the ecophysiological parameters of the BSCs during the melt and at the end of the growing period. The results clearly identified differences in physiological and ecological indexes between snowfall manipulation treatments in March, and further found that the values of most of the ecophysiological indexes were influenced by snow removal/reduction treatments, the type of BSC and their interaction effect. The chlorophyll fluorescence parameters, chlorophyll content, and the rates of photosynthesis and respiration of all three types of crust declined because of decreased soil water content with decreased snow cover, and this effect would likely be even greater under conditions of decreased precipitation. The rates of photosynthesis and respiration of the main types of BSC were changed by variations in the winter snowfall, and confirmed the existence of long‐term snowfall impacts on photosynthetic carbon fixation and biomass accumulation. These results provide a foundation for future studies to assess the potential effects of snowfall on the carbon sequestration of BSCs from arid and semi‐arid regions.

Drought Impacts on Competition in Phoetaliotes nebrascensis (Orthoptera Acrididae) in a Northern Mixed Grassland.

Global climate change is predicted to significantly modify patterns of precipitation, making it critical to develop a better understanding of how this will modify biotic interactions. Short-term to decadal-scale weather patterns can impact grasshopper population dynamics, but drought impacts on grasshoppers have rarely been studied in manipulative experiments. A cage experiment was conducted in eastern Montana to examine the impact of intra- and interspecific competition and precipitation manipulation treatments on performance of a common melanopline grasshopper Phoetaliotes nebrascensis (Thomas). High-density and drought treatments had similarly strong negative impacts on food availability. Proportional grasshopper survival did not differ significantly by treatment, but density dependence was evident in both body size and reproductive traits. The impact of precipitation and density treatments on grasshopper body size and reproduction were typically similar in magnitude and much larger than interspecific competition, with the exception of male femur length. Even with high late summer precipitation, drought had strong effects on individual body size and future reproduction. This study provides valuable information on population dynamics of an abundant grasshopper, with moderate precipitation reductions negatively affecting reproduction and body size. No positive impacts of drought as predicted by the plant stress hypothesis were observed. The study reinforces the need to examine drought manipulations to better predict grasshopper population changes due to changing climate conditions.

Lotic bacterioplankton and phytoplankton community changes under dissolved organic-carbon amendment: evidence for competition for nutrients

During periods of low river discharge, bacterial growth is typically limited by dissolved organic carbon (DOC) and is tightly regulated by phytoplankton production. However, import of allochthonous DOC into rivers by freshwater inflows may diminish bacterial reliance on phytoplankton-produced carbon, leading to competition for nitrogen (N) and phosphorus (P). To investigate phytoplankton–bacterial competition in response to allochthonous inputs, we conducted a mesocosm experiment, comparing microbial responses to the following two manipulation treatments: (1) addition of N and P, and (2) addition of a DOC and N and P. Measurement of chlorophyll-a estimated phytoplankton biomass and microscopic counts were performed to discriminate community change. Bacterial abundance was tracked using flow cytometry and community assemblages were characterised using automated ribosomal intergenic spacer analyses and 16S rRNA-amplicon sequencing. We found that bacterial abundance increased in the leachate addition, whereas chlorophyll-a was reduced and the bacterial community shifted to one dominated by heterotrophic genera, and autotrophic microbes including Synechococcus and Cyclotella increased significantly in the nutrient treatment. These observations indicated that DOC and nutrient inputs can lead to shifts in the competitive dynamics between bacteria and phytoplankton, reducing phytoplankton biomass, which may potentially shift the major pathway of carbon to higher trophic organisms, from the phytoplankton grazer chain to the microbial food web.

Expression of the estrogen and relaxin receptors in human fascial tissue

Fascia is a tissue that interact with different structure in a very precise manner. It creates a structural continuity that give form and function to every tissue and organ. It plays a significant role in mechanical tension, transmitting force, correct motor coordination so altered structure of specific components layers could be generate a clinical problem. Recent studies have shown the possible role of the fascial nociceptors to mechanical and chemical stimuli may contribute to myofascial or musculoskletal pain (1). Many epidemiologic, clinical, and experimental evidence points to sex differences in myofascial pain, and generally adult women more often have myofascial problems than do men (2). It is possible that one of the stimuli to sensitization of fascial nociceptors could come from hormonal factors such as estrogen and relaxin that are involved in extracellular matrix and collagene remodelling (3). Relaxin-2 (RLX-2) is recognized as anti-fibrotic factor that is the ligand for RXFP1. Estrogens and in particular 17β-estradiol (E2) regulate a widespread of physiological functions and the actions are mediated by two estrogen receptor isoforms, ERα and ERβ. We hypothesized that E2 and relaxin contribute on metabolism and function of myofascial tissue. Immunohistochemical and molecular investigation (real-time PCR analysis) for RXFP1 and ERα localization were carried out in human fascia of different districts (peroneal, abdomen rectum, hip and low back fascia) and in fibroblasts isolated from the same districts, with the aim of describing both protein and RNA expression. ERα and RXFP1 are expressed on fibroblasts of human fascial tissues and RXFP1 expression was particular intense on vessels and nerves. These results are confirmed in isolated fibroblasts derived from the same fascial districts. Not all the cells have the same reactivity but the positive reaction was evident in the cytoplasm of cells for RXFP1 and with more intensity on nuclei of cells for ERα. Our results are the first demonstration that the fibroblasts of different districts of the muscular fasciae express sex hormone receptors. These findings could represent a new target for the care of myofascial pain and the possible stimulation during manipulative treatments and exercises. More studies about the interactions between fibroblasts, extracellular matrix and hormone receptors (estrogen, progesteron, relaxin) could help to understand the role of these receptors on myofascial pain.

Expression of the endocannabinoid receptors in human fascial tissue

Endocannabinoids are endogenous lipid mediators with wide range of biological effects similar to those of marijuana. They exert their biological effects via two main G-protein-coupled cannabinoid receptors, the CB1 (cannabinoid receptor 1) and CB2 (cannabinoid receptor 2). Cannabinoid receptors have been localized in the central and peripheral nervous system as well as on cells of the immune system, but recent studies gave evidence for the presence of cannabinoid receptors in different types of tissues (1,2) Their presence was supposed in myofascial tissue, suggesting that the endocannabinoid system may help resolve myofascial trigger points, suppressing proinflammatory cytokines such as IL-1beta e TNF-alpha and increasing anti-inflammatory cytokines (3, 4). However, until now the expression of CB1 and CB2 in fasciae and in fascial fibroblasts has not yet been established. In this work small samples of fascia were collected from volunteers patients: for each sample were done a fibroblast cell isolation, immunohistochemical investigation (CB1 and CB2 antibodies) and real time RT-PCR to detect the expression of CB1 and CB2. The immunostaining results demonstrate the expression of CB2 and CB1 on fascial fibroblasts and fascial tissue. In the tissue not all the fibroblasts are positive, whereas the isolated and expanded cells are homogeneous. These results are confirmed by the real time PCR where the specificity of the reaction on fibroblasts and fascial tissue is the same, but the amount of expression in the tissue is lower, for both CB1 and CB2. This is the first demonstration that the fibroblasts of the muscular fasciae express CB1 and CB2. These results could represent a new target for drugs to care fascial fibrosis and inflammation. The presence of the endocannabinoid system in the fascial fibroblasts can also explain the efficacy of cannabis to care myofascial pain and the possible stimulation during manipulative treatments and exercises (5). More studies about the interactions between fibroblasts, extracellular matrix and CB1 and CB2 receptors could help to understand the role of these receptors on myofascial pain.

Enhanced gross nitrogen transformation rates and nitrogen supply in paddy field under elevated atmospheric carbon dioxide and temperature

Climate change, particularly the combined effects of elevated CO2 and temperature, is likely to alter the internal nitrogen (N) cycle of agricultural ecosystems. However, little is known about such phenomena in paddy soils, which are expected to expand in the near future due to population increase. A 15N tracer study, with soil taken from field manipulation treatments, showed that elevated CO2, either alone or combined with elevated temperature, stimulated the mineralization of labile organic N 37-fold but decreased the mineralization of recalcitrant organic N. In contrast, elevated temperature alone accelerated the mineralization of recalcitrant organic N approximately 2-fold but had no effect on the mineralization of labile organic N. Ammonium immobilization increased under elevated CO2 and elevated temperature. Gross and net NO3− production decreased under elevated CO2 and the combined treatments, whereas elevated temperature caused an increase in both rates. Dissimilatory reduction of NO3− to NH4+ increased under elevated CO2 but decreased with elevated temperature. Our findings suggest that progressive N limitation can be alleviated by increasing gross N transformation rates under each climate change treatment and that counteraction will dominate the interactive responses of CO2 and temperature. Because we expect a concomitant increase in both CO2 and temperature, we only expect minor effects of these particular factors arising as a result of climate on soil N dynamics in paddy soils.

Climate change may reduce litter decomposition while enhancing the contribution of photodegradation in dry perennial Mediterranean grasslands

Understanding how the interactions between solar UV radiation and climate will affect leaf litter decomposition is fundamental to predict how soil and ecosystem biogeochemical cycles will respond to ongoing climate change. We carried out a manipulative experiment to investigate how UV radiation and its interaction with increased temperature (3 °C on average) and a ∼35% reduction in precipitation affect the decomposition of “standing” and “on the ground” litter of Stipa tenacissima, a dominant species in semiarid Mediterranean grasslands. UV radiation was manipulated using specially designed screens that either passed or blocked 90% of the UV radiation. All climate change manipulation treatments decreased litter decomposition compared to the control treatment. In particular, litter decay rates were reduced by a 34%, 43% and 62% in the rainfall reduction (RE), warming (W), and the combination of warming and rainfall reduction (WRE) treatments, respectively, compared to the control treatment. Across climate manipulation treatments, higher decay rates were observed in litter exposed to UV radiation than in litter non-exposed to UV radiation, and in litter placed on the ground than in standing litter. However, significant interactions were found between climate manipulation and UV exposure or position treatments. In the control and RE treatments, litter on the ground decomposed 25% faster than standing litter. In the W and WRE treatments, litter decomposition rates increased by 29% when exposed to UV radiation despite lower overall decay rates were observed in these treatments. Overall, lignin losses were parallelled by increases in soluble cell materials, particularly when litter was exposed to UV radiation. Our results indicate that predicted climate change scenarios will likely reduce leaf litter decomposition rates, while enhancing the relative contribution of photodegradation to overall litter decomposition in dry perennial Mediterranean grasslands.

Modeled Osteopathic Manipulative Treatments: A Review of Their in Vitro Effects on Fibroblast Tissue Preparations.

A key osteopathic tenet involves the body's ability to self-heal. Osteopathic manipulative treatment (OMT) has been evolved to improve this healing capacity. The authors' in vitro work has focused on modeling 2 common OMT modalities: myofascial release (MFR) and counterstrain. Their studies have evaluated the effects of these modalities on wound healing, cytokine secretion, and muscle repair. The key components of the host response to mechanical forces are fibroblasts, which are the main fascial cells that respond to different types of strain by secreting anti-inflammatory chemicals and growth factors, thus improving wound healing and muscle repair processes. The purpose of this review is to discuss the cellular and molecular mechanisms by which MFR and other OMT modalities work, in particular, the role of strained fibroblasts in inflammation, wound healing, and muscle repair and regeneration. Changing MFR parameters, such as magnitude, duration, direction, and frequency of strain, might uniquely affect the physiologic response of fibroblasts, muscle contraction, and wound healing. If such results are clinically translatable, the mechanisms underlying the clinical outcomes of OMT modalities will be better understood, and these treatments will be more widely accepted as evidence-based, first-line therapies.

Do alterations in mesofauna community affect earthworms?

Interactions between the saprotrophic animal groups that strongly control soil microbial activities and the functioning of detrital food webs, such as earthworms and mesofauna, are not well understood. Earthworm trophic and engineering activities strongly affect mesofauna abundance and diversity through various direct and indirect pathways. In contrast, mesofauna effects on earthworm populations are less evident; however, their importance may be high, considering the keystone significance of earthworms for the functioning of the soil system. We studied effects of a diverse mesofauna community of a deciduous forest on two earthworm species representing epigeic (Lumbricus rubellus) and endogeic (Aporrectodea caliginosa) ecological groups. In microcosms, the density of total mesofauna or its separate groups (enchytraeids, collembolans, gamasid mites) was manipulated (increased) and responses of earthworms and soil systems were recorded. A rise in mesofauna density resulted in a decrease of biomass and an increased mortality in L. rubellus, presumably due to competition with mesofauna for litter resources. In contrast, similar mesofauna manipulations promoted reproduction of A. caliginosa, suggesting a facilitated exploitation of litter resources due to increased mesofauna activities. Changes of microcosm respiration rates, litter organic matter content and microbial activities across the manipulation treatments indicate that mesofauna modify responses of soil systems in the presence of earthworms. However, similar mesofauna manipulations could induce different responses in soil systems with either epigeic or endogeic lumbricids, which suggests that earthworm/mesofauna interactions are species-specific. Thus, mesofauna impacts should be treated as a factor affecting the engineering activities of epigeic and endogeic earthworms in the soil.

The DIRT Experiment

Resolving carbon use by fungi and bacteria is thought to capture disparate life strategies for soil microbial decomposers, associating bacteria with a fast but leaky use of carbon (C) and nutrients, and fungi with a slow but efficient use. We tested these ideas using the Detritus Input and Removal Treatments (DIRT) experiment, where litter and root inputs had been experimentally manipulated during 23 years, generating differences in soil C quality. We find no support for the presumed differences between fungal- and bacterial-dominated detrital food webs in these soils, calling for a revision of our basic understanding of microbial communities and the processes they regulate. The different litter manipulation treatments of the DIRT experiment. Photo by Mel Knorr. These photographs illustrate the article ”Revisiting the hypothesis that fungal-to-bacterial dominance characterizes turnover of soil organic matter and nutrients” by Johannes Rousk and Serita D. Frey, tentatively scheduled to appear in Ecological Monographs 85(3), August 2015. http://dx.doi.org/10.1890/14-1796.1

A single and rapid calcium wave at egg activation in Drosophila.

Activation is an essential process that accompanies fertilisation in all animals and heralds major cellular changes, most notably, resumption of the cell cycle. While activation involves wave-like oscillations in intracellular Ca2+ concentration in mammals, ascidians and polychaete worms and a single Ca2+ peak in fish and frogs, in insects, such as Drosophila, to date, it has not been shown what changes in intracellular Ca2+ levels occur. Here, we utilise ratiometric imaging of Ca2+ indicator dyes and genetically encoded Ca2+ indicator proteins to identify and characterise a single, rapid, transient wave of Ca2+ in the Drosophila egg at activation. Using genetic tools, physical manipulation and pharmacological treatments we demonstrate that the propagation of the Ca2+ wave requires an intact actin cytoskeleton and an increase in intracellular Ca2+ can be uncoupled from egg swelling, but not from progression of the cell cycle. We further show that mechanical pressure alone is not sufficient to initiate a Ca2+ wave. We also find that processing bodies, sites of mRNA decay and translational regulation, become dispersed following the Ca2+ transient. Based on this data we propose the following model for egg activation in Drosophila: exposure to lateral oviduct fluid initiates an increase in intracellular Ca2+ at the egg posterior via osmotic swelling, possibly through mechano-sensitive Ca2+ channels; a single Ca2+ wave then propagates in an actin dependent manner; this Ca2+ wave co-ordinates key developmental events including resumption of the cell cycle and initiation of translation of mRNAs such as bicoid.

Evaluation of stress and pain in young children with cerebral palsy during early developmental intervention programs: a descriptive study.

The aim of this study was to use the Face, Legs, Activity, Cry, Consolability Scale; salivary cortisol levels; and withdrawal reflex thresholds to assess pain, stress, and pain sensitivity in young children with cerebral palsy during early developmental intervention programs. A total of 40 children with cerebral palsy (age range, 1-4 yrs) participated in the early intervention programs, which included neurodevelopmental treatment, neuromuscular electrical stimulation, occupational therapy, head acupuncture, and Chinese traditional manipulation five times per week for 3 wks. The Face, Legs, Activity, Cry, Consolability Scale was applied during the course of each treatment, and salivary cortisol samples were obtained from each child 10 mins before and 10 mins after each treatment. Withdrawal reflex thresholds were assessed via mechanical stimulation of the foot with von Frey hairs. All treatment programs caused some degree of pain. In descending order, the extents of the pain caused by each treatment were head acupuncture, neurodevelopmental treatment, neuromuscular electrical stimulation, Chinese traditional manipulation, and occupational therapy. There were statistically significant increases in salivary cortisol levels after the head acupuncture (P < 0.001), neurodevelopmental treatment (P < 0.001), neuromuscular electrical stimulation (P < 0.001), and Chinese traditional manipulation (P < 0.001) treatments. No significant changes were found in the withdrawal reflex thresholds during the study (P > 0.05). The results of this study demonstrate that early developmental intervention programs cause pain and stress in young children with cerebral palsy.

Multimodal compared to pharmacologic treatments for chronic tension-type headache in adolescents

Chronic tension-type headache (CTTH) in children and adolescents is a serious medical condition, with considerable morbidity and few effective, evidence-based treatments. We performed a chart review of 83 adolescents (age range=13-18 years; 67 girls and 16 boys) diagnosed with CTTH. Two treatment protocols were compared: multimodal (osteopathic manipulative treatments, mindfulness, and qi gong) and pharmacologic (amitriptyline or gabapentin). Four outcomes (headache frequency, pain intensity, general health, and health interference) were assessed at three time points (baseline, 3 months, and 6 months). A fifth outcome, number of bilateral tender points, was recorded at baseline and 6 months. All five were evaluated statistically with a linear mixed model. Although both multimodal and pharmacologic treatments were effective for CTTH (time effects for all measures were significant at p<.001), results from each analysis favored multimodal treatment (the five group by time interaction effects were significant at or below the p<.001 level). Headache frequency in the pharmacologic group, for example, reduced from a monthly average (95% Confidence Interval shown in parentheses) of 23.9 (21.8, 26.0) to 16.4 (14.3, 18.6) and in the multimodal group from 22.3 (20.1, 24.5) to 4.9 (2.6, 7.2) (a substantial group difference). Pain intensity (worst in the last 24 hours, 0-10 scale) was reduced in the pharmacologic group from 6.2 (5.6, 6.9) to 3.4 (2.7, 4.1) and from 6.1 (5.4, 6.8) to 2.0 (1.2, 2.7) in the multimodal group (a less substantial difference). Across the other three assessments, group differences were larger for general health and number of tender points and less so for pain restriction. Multimodal treatment for adolescent CTTH appears to be effective. Randomized controlled trials are needed to confirm these promising results.