Growth Depression Research Articles

Influence of larval outbreaks on the climate reconstruction potential of an Arctic shrub

Arctic shrubs have a strong potential for climate and environmental reconstructions in the chronically understudied regions of the high northern latitudes. The climate dynamics of these regions are important to understand because of large-scale feedbacks to the global climate system. However, little is known about other factors influencing shrub ring growth, possibly obscuring their climate signal. For example, as of yet we are not able to differentiate between herbivory or climatically induced growth depressions. Here, we use one of the most common Arctic shrubs, Alnus viridis as a test case to address this question. We sampled Alnus in Kobbefjord, Greenland, measured shrub-ring width and cell wall thickness and built site chronologies of each parameter. We analysed climate-growth relationships, tested their stability over time and employed a pointer-year analysis to detect growth depressions. We employed bootstrapped transfer function stability tests (BTFS) to assess the suitability of our shrub chronologies for climate reconstruction. Correlations with climate data showed strong significantly positive and stable correlations between summer temperature and ring-width with the exception of the recent decade. A climate reconstruction model failed stability tests, when the complete period of record was used for calibration and verification. Wood anatomy analysis uncovered the occurrence of unusual cell structure (very thin cell walls) in the exceptionally narrow ring of 2004, a recorded insect outbreak year in other parts of Greenland. When excluding the affected ring and a recovery period, the reconstruction model passed all tests, suggesting that the unusual 2004 ring was not climate driven, but rather the result of an insect attack. When combining anatomical analysis with traditional ring-width measurements, we move a step further in potentially distinguishing small rings caused by insect attacks from small rings formed in climatically challenging years. While this study does not provide unambiguous evidence, it does provide potential useful methodological combinations to enable more robust climate reconstructions in areas where climatic records are extremely sparse.

Soy protein concentrate as a substitute for fish meal in diets for juvenile Acanthopagrus schlegelii: effects on growth, phosphorus discharge and digestive enzyme activity

The current high demand and cost of fish meal (FM) necessities the evaluation of alternative plant protein ingredients in diets of farmed marine fish. A 56-day feeding trial was performed to study the effects of replacement of FM with soy protein concentrate (SPC) in diets of Acanthopagrus schlegelii. Diets were prepared at levels of 0%, 30%, 47.5%, 65%, 82.5% and 100% SPC, respectively, replacing FM. The results indicated no significant differences (p > .05) in % weight gain (WG) and specific growth rate of fish fed S30% to S82.5% diets compared with the control diet while, further inclusion at 100% significantly depressed growth performance. SPC inclusion and phytase supplementation significantly affected the phosphorous discharge (P-load) showing lowest value (3.83 ± 0.53 g/kg WG) in S100% compared to control (14.79 ± 0.37 g/kg WG) and in fish fed S30% diet (13.24 ± 0.89 g/kg WG) (p < .05). The results of this study showed that FM could be substituted up to 82.5% by SPC in the diet of Acanthopagrus schlegelii fingerlings (5.53 ± 0.12 g) without any adverse effects. Phytase supplementation SPC based diets could be effective in reducing the phosphorus load in the aquatic culture environment.

Linking dendroecology and association genetics in natural populations: Stress responses archived in tree rings associate with SNP genotypes in silver fir (Abies alba Mill.).

Genetic association studies in forest trees would greatly benefit from information on the response of trees to environmental stressors over time, which can be provided by dendroecological analysis. Here, we jointly analysed dendroecological and genetic data of surviving silver fir trees to explore the genetic basis of their response to the iconic stress episode of the 1970s and 1980s that led to large-scale forest dieback in Central Europe and has been attributed to air pollution. Specifically, we derived dendrophenotypic measures from 190 trees in the Bavarian Forest that characterize the resistance, resilience and recovery during this growth depression, and in the drought year in 1976. By focusing on relative growth changes of trees and by standardizing the dendrophenotypes within stands, we accounted for variation introduced by micro- and macroscale environmental differences. We associated the dendrophenotypes with single nucleotide polymorphisms (SNPs) in candidate genes using general linear models (GLMs) and the machine learning algorithm random forest with subsequent feature selection. Most trees at our study sites experienced a severe growth decline from 1974 until the mid-1980s with minimum values during the drought year. Fifteen genes were associated with the dendrophenotypes, including genes linked to photosynthesis and drought stress. With our study, we show that dendrophenotypes can be a powerful resource for genetic association studies that permit to account for micro- and macroenvironmental variation when data are derived from natural populations. We call for a wider collaboration of dendroecologists and forest geneticists to integrate individual tree-level dendrophenotypes in genetic association studies.

Co-development of Problem Gambling and Depression Symptoms in Emerging Adults: A Parallel-Process Latent Class Growth Model.

This study examines whether there are multiple joint trajectories of depression and problem gambling co-development in a sample of emerging adults. Data were from the Manitoba Longitudinal Study of Young Adults (n=679), which was collected in 4 waves across 5years (age 18-20 at baseline). Parallel process latent class growth modeling was used to identified 5 joint trajectory classes: low decreasing gambling, low increasing depression (81%); low stable gambling, moderate decreasing depression (9%); low stable gambling, high decreasing depression (5%); low stable gambling, moderate stable depression (3%); moderate stable problem gambling, no depression (2%). There was no evidence of reciprocal growth in problem gambling and depression in any of the joint classes. Multinomial logistic regression analyses of baseline risk and protective factors found that only neuroticism, escape-avoidance coping, and perceived level of family social support were significant predictors of joint trajectory class membership. Consistent with the pathways model framework, we observed that individuals in the problem gambling only class were more likely using gambling as a stable way to cope with negative emotions. Similarly, high levels of neuroticism and low levels of family support were associated with increased odds of being in a class with moderate to high levels of depressive symptoms (but low gambling problems). The results suggest that interventions for problem gambling and/or depression need to focus on promoting more adaptive coping skills among more "at-risk" young adults, and such interventions should be tailored in relation to specific subtypes of comorbid mental illness.

Dispositional mindfulness moderates the relationship between depression and posttraumatic growth in Chinese adolescents following a tornado

This study explored whether dispositional mindfulness moderated the relationship between depression and posttraumatic growth. A total of 435 Chinese adolescents who experienced a tornado in Yancheng city reported their level of depressive symptoms (The Center for Epidemiologic Studies Depression Scale for Children; CES-DC), posttraumatic growth (Posttraumatic Growth Inventory; PTGI) and dispositional mindfulness (Mindfulness Attention Awareness Scale; MAAS). The current study found that for individuals with higher dispositional mindfulness, their depression was associated with more posttraumatic growth, while the individuals with lower dispositional mindfulness showed no such association. These findings suggest that individuals high in dispositional mindfulness possess the potential to benefit from the process of adaptive coping in response to depression following a traumatic experience. The implications of the results for research and mindfulness-based interventions targeting depression were discussed.

Natural Disasters in Indonesia: Relationships Among Posttraumatic Stress, Resource Loss, Depression, Social Support, and Posttraumatic Growth

ABSTRACTIndonesia is at significant risk for catastrophic natural disasters, including earthquakes, volcanic eruptions, and tsunamis. Few studies have examined psychological functioning following disaster exposure in Indonesia, the fourth most populous country in the world. This study assesses variables associated with posttraumatic stress and posttraumatic growth following a devastating earthquake in Central Java that ranks as one of the costliest in Indonesia. The participants were 85 men and women living in rural farming villages. Almost all (95%) experienced major home damage or total home destruction. Posttraumatic stress symptoms were associated with resource loss, depression, and concerns about future earthquakes. Participants reported moderate posttraumatic growth. Posttraumatic growth was associated with energy resource loss and social support. The findings support conservation of resources stress theory. The implications of the findings for intervention and recovery programs are discussed.

Spatial and temporal limits of coral-macroalgal competition: the negative impacts of macroalgal density, proximity, and history of contact.

Tropical reefs are commonly transitioning from coral- to macroalgal-dominance, producing abrupt, and often lasting, shifts in community composition and ecosystem function. Although negative effects of macroalgae on corals are well documented, whether such effects vary with spatial scale or the density of macroalgae remains inadequately understood, as does the legacy of their impact on coral growth. Using closely adjacent coral- versus macroalgal-dominated areas, we tested effects of macroalgal competition on the Indo-Pacific corals Acropora millepora and Porites cylindrica. When corals were transplanted to areas of: i) macroalgal-dominance, ii) macroalgal-dominance but with nearby macroalgae removed, or iii) coral-dominance lacking macroalgae, coral growth was equivalently high in plots without macroalgae and low (62-90% less) in plots with macroalgae, regardless of location. In a separate experiment, we raised corals above the benthos in each area and exposed them to differing densities of the dominant macroalga Sargassum polycystum. Coral survivorship was high (≥ 93% after 3 months) and did not differ among treatments, whereas the growth of both coral species decreased as a function of Sargassum density. When Sargassum was removed after two months, there was no legacy effect of macroalgal density on coral growth over the next seven months; however, there was no compensation for previously depressed growth. In sum, macroalgal impacts were density dependent, occurred only if macroalgae were in close contact, and coral growth was resilient to prior macroalgal contact. The temporal and spatial constraints of these interactions suggest that corals may be surprisingly resilient to periodic macroalgal competition, which could have important implications for ecosystem trajectories that lead to reef decline or recovery.

How newly diagnosed HIV-positive men who have sex with men look at HIV/AIDS \u2013 validation of the Chinese version of the revised illness perception questionnaire

BackgroundNewly diagnosed HIV-positive men who have sex with men (MSM) are an important subgroup in HIV intervention. How newly diagnosed HIV-positive MSM look at HIV/AIDS is consequential and is potentially associated with their risk behaviors and mental health problems. Illness representation has been used to define patients’ beliefs and expectations on an illness, and the revised Illness Perception Questionnaire (IPQ-R) has been developed to measure illness representations. This study aims to examine the psychometric properties of the IPQ-R among newly diagnosed HIV-positive MSM and to investigate their views towards HIV/AIDS.MethodA total of 225 newly diagnosed HIV-positive MSM completed the Chinese version of IPQ-R. Both confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) were applied to examine the factor structure of IPQ-R.ResultsCFA showed a poor goodness of fit to the original factor structure of IPQ-R. EFA of the IPQ-R revealed 7 factors, including Emotional Response, Treatment Control, Timeline-acute/chronic, Illness Coherence, Consequence, Personal Control and Helplessness. Cronbach’s alpha showed acceptable internal consistency for the derived factors, except the Personal Control (0.61) and Helplessness (0.55). Person correlation coefficients demonstrated that the derived factors of IPQ-R had significant associations with the outcome variables (depression and posttraumatic growth). The scores of the Emotional Response, Consequence, Treatment Control, Personal Control, Timeline-acute/chronic and Illness Coherence were above the midpoint, and the score of the Helplessness was below the midpoint.ConclusionBoth similarities and differences were found when the IPQ-R is applied to newly diagnosed HIV-positive MSM. The IPQ-R can be used with some refinements in future studies. Newly diagnosed HIV-positive MSM have a relatively high level of negative perceptions towards HIV/AIDS in both cognitive and emotional aspects.

Banana Stem Bokashi and its Effect to Increase Soybean Yield (Glycine max L. Merrill) in Coastal Sands Area

The development of soybeans in coastal sand area besides using adaptive cultivars also requires the input of organic matter to increase its productivity. One source of organic material that has not been widely used is banana stem. The research aimed to study: 1) the characteristics of banana stems bokashi and its role to improving the growth and yield of some soybean cultivars, and 2) Response growth and yield of soybean cultivars at the level of banana stem bokashi in the coastal sands. The research is a laboratory and field experiment conducted for 6 months from October 2016 until March 2017. Pot experiments in the field have been done in Samas coastal sands, Srigading Village, Sanden Sub-district, Bantul Regency, special Region of Yogyakarta. The factorial experiment (4 × 12) was repeated 3 times, arranged in a complete randomized block design (RCBD). The first factor was dose banana stem bokashi including 0, 20, 40, and 60 t.ha-1; was tested on 12 soybean cultivars namely Anjasmoro, Argomulyo, Burangrang, Demas 1, Dena 1, Devon 1, Gamasugen 1, Gema, Gepak Ijo, Grobogan, Kaba, and Slamet. The observational data were analyzed by the variant analysis of the error rate of 5% and if significantly different was followed by DMRT 5% error level. The results showed that bokashi made from banana stem has chemical composition which can be used as a soil conditioner and as organic fertilizer. Soybean cultivars respond to various doses of bokashi given. In general, soybean cultivars increased growth and yield of seeds in bokashi application to optimum dosage, and did not increase again with higher doses. However, there are also soy cultivars that are not responsive or even depressed growth and yield of seeds when given bokashi banana stem.

The Nexus between Tax Revenue and Government Expenditure in Kenya

In lieu of rising budget deficits in many countries across the world, driven by tax revenue insufficiency in financing government expenditure, many governments continue to accumulate public debt due to the financing of budget deficits. In the long run, however, persistent budget deficits as well as debt accumulation are unsustainable and pose several problems to the economy including inflationary spirals, depressed growth, higher associated poverty levels and consequently fiscal crisis. To offer any policy prognosis towards controlling and consequently reducing budget deficit requires an understanding of the nexus between tax revenue and government expenditure. This study examined this nexus in Kenya, for 1960-2011. Data was collected from Kenya economic surveys from 1960-2012. Because data was available in fiscal years, it was converted to calendar years by splicing. Augmented Dickey Fuller and Philips Perron unit root tests were employed to establish the stationary properties of the series while the Johansen and Juselius co-integration techniques were used to determine presence of linear long run economic relationships in the series. The study established that budgetary authorities follow the spend-revenue hypothesis. The study recommends resort to fiscal discipline, especially by cutting down on nonproductive expenditure.

Links between Depression and Fixed Versus Growth Mindsets

Links between Depression and Fixed Versus Growth Mindsets

Effect of Headspace and Trapped Volatile Organic Compounds (VOCs) of the Chinese Caterpillar Mushroom, Ophiocordyceps sinensis (Ascomycetes), against Soil-Borne Plant Pathogens.

Headspace volatile metabolites produced by Ophiocordyceps sinensis were tested against soil-borne plant pathogens (namely, Fusarium oxysporum f. sp. lycopersici, F. oxysporum f. sp. cubense, Thanatephorus cucumeris, Athelia rolfsii, and Macrophomina phaseolina). Diffusible volatile metabolites produced by O. sinensis inhibited 52% and 48% of the mycelial growth of F. oxysporum f. sp. lycopersici and F. oxysporum f. sp. cubense, respectively. In addition to inhibiting mycelial growth, the headspace volatile metabolites also induced several morphological changes in the culture characteristics and mycelia of the tested fungi. Stunted and depressed colony growth was observed for F. oxysporum f. sp. cubense and F. oxysporum f. sp. lycopersici. The headspace volatile compounds produced by O. sinensis were trapped in a glass cartridge (Porapak Q). The trapped compounds were eluted from the column by using hexane and then, by using gas chromatography-mass spectrometry, were identified as tetratetracontane, 1(2H)-naphthalenone, 3, 4-dihydro-3-methyl, 3-hexenoic acid, 1-methyl-3-ethyladamantane, and phenol, 3-ethyl.

Effects of 50 Percent Substitution of Soybean Meal by Alternative Proteins from &amp;lt;i&amp;gt;Hermetia illucens&amp;lt;/i&amp;gt; or Spirulina platensis in Meat-Type Chicken Diets with Graded Amino Acid Supply

Alternative protein sources, such as insects or algae meals are in special focus of animal nutrition in order to replace soybean meal (SBM). As part of the multidisciplinary project “sustainability transitions” this study evaluated effects of replacing SBM by partly defatted larvae meal from the black soldier fly, Hermetia illucens or meal from the micro algae Spirulina platensis in broiler diets. The aim of the current study was to investigate the chickens’ growth performance and the intestinal morphology as well as the health status. 288 one-day-old male growing chickens (Ross 308) from a commercial hatchery were randomly allotted to 48 pens (6 birds per pen) for the growth study with five diets and feed supply on free choice level. The control diet was based on wheat, corn and SBM. The experimental diets replaced 50% of SBM by the alternative proteins under study, both on a basic level of amino acid (AA) supplementation (Lys and Met added equal to the control diet) (diet HM and SM) and an extended level of AA fortification (Lys, Met, Thr, Arg, Val added) (diet HM+ and SM+). Response of chickens was evaluated by zoo-technical parameters, which were under weekly control (e.g. growth, feed intake, feed conversion ratio, mortality). After finishing the growth study birds from control and the experimental diets at the basic level of AA supplementation were slaughtered after 12 hour fastening and utilized for gut morphometric analysis and histological evaluation of the health status. Diets at a basic level of AA fortification led to significant depression of growth, feed intake, feed conversion ratio, and protein conversion ratio, respectively. In addition, the acceptance of the Spirulina diet was lower (p ≤ 0.001) as compared to the Hermetia based diet. However, the extended level of AA supplementation improved all parameters significantly. Diets without extended AA supply altered some morphological parameters of the intestinal wall, but the nutritional significance of this observation needs to be verified in AA balanced diets. The health state of chicken was not impaired by the diets under study.

Influence of invasive shrubs and deer browsing on regeneration in temperate deciduous forests

While both chronic white-tailed deer (Odocoileus virginianus Zimmermann) overbrowsing and invasive shrubs have been linked to native regeneration failure in temperate hardwood forests, little is known of their relative importance and possible synergistic effects. Therefore, we established three study areas in Connecticut to examine the interaction of three levels of invasive shrub control and absence or presence of deer herbivory on forest regeneration over 9 years. Five observations suggest that obtaining forest regeneration requires a comprehensive management strategy. First, competitive interference by invasive shrubs in intact thickets continued to impede forest regeneration, especially taller seedlings, after deer were excluded. Second, density of small seedlings increased following removal of the competitive interference by invasive shrubs. Third, deer browsing depressed growth of small seedlings into taller height classes. Fourth, preferential browsing reduced species richness, especially in taller seedling classes, by favoring growth of low palatability species such as beech. Lastly, if a disturbance (e.g., cutting) does not kill the root system of the invasive shrubs, the window of forest regeneration recruitment may be narrow because invasive shrubs can quickly recover. In stands with both established shrub thickets and high deer densities, invasive shrub control and multiyear reduction of deer densities are both recommended to obtain adequate forest regeneration.

Examining cancer survivorship trajectories: Exploring the intersection between qualitative illness narratives and quantitative screening instruments.

This article examines the associations of quantitatively refined trajectories of adjustment to cancer survivorship determined by previously published qualitative narrative analysis. Patients completed measures of cancer-related worry (Cancer Related Worries Scale), depression (Patient Health Questionnaire-9), posttraumatic growth (Benefit Finding Scale), and open-ended survey questions 6, 12, and 18 months postdiagnosis of head and neck, esophageal, gastric, or colorectal cancer. Previously published narrative analysis revealed five distinct survivorship "paths," which were combined into four paths in the present article: Moving On, Seeing the World Differently, Taking One Day at a Time, and Never the Same. To determine the association of qualitatively determined paths with quantitatively assessed adjustment (i.e., Cancer Related Worries Scale, Patient Health Questionnaire-9, Benefit Finding Scale), we used linear multilevel modeling to regress the adjustment variables on time, path, the time-by-path interaction, and relevant covariates (age, stage, cancer site, ethnicity, and Deyo score). There was a significant main effect of path on cancer worry, depression, and posttraumatic growth (p &lt; 0.02 for all). Patients in the Moving On group reported consistently low worry, depression, and growth compared to the other groups. Patients in the Seeing the World Differently and Taking One Day at a Time paths both reported moderate worry and depression; but those in the Seeing the World Differently path reported the highest posttraumatic growth, whereas patients in the Taking One Day at a Time path reported little growth. Finally, patients in the Never the Same path reported the highest worry and depression but lowest posttraumatic growth.Significance of resultsThis longitudinal study reinforces the notion that cancer survivorship is not a one-size-fits-all experience nor a dichotomized experience of "distress" or "no distress." Additionally, this hypothesis-generating study suggests future directions for potential self-report measures to help clinicians identify cancer survivors' trajectory to develop a more patient-centered survivorship care plan.

Evaluation of tryptophan-aspartic acid repeat-containing protein 34 as a novel tumor-suppressor molecule in human oral cancer

Tryptophan-aspartic acid (WD) repeat-containing protein 34 (WDR34), one of the WDR protein superfamilies with five WD40 domains, inhibits a transforming growth factor-beta (TGF-β) activated kinase 1 (TAK1)-associated NF-κB activation pathway. Nevertheless, little is known about the roles of WDR34 in cancer. The current study sought to elucidate the clinical relevance of WDRsfb34 in oral squamous cell carcinoma (OSCC). We found WDR34 down-regulation in OSCCs compared with normal control tissues using real-time quantitative reverse transcription-polymerase chain reaction, immunoblotting, and immunohistochemistry. Models of overexpression of WDR34 (oeWDR34) showed depressed cellular growth through cell-cycle arrest at the G1 phase. To investigate the inhibitory function of WDR34, we challenged oeWDR34 cells with interleukin (IL)-1, a ligand for activation of the TAK1-NF-κB pathway and assessed the expression of a target gene of the pathway. oeWDR34 strongly inhibited IL-6 expression, which is closely related to tumoral growth, compared with control cells, suggesting that WDR34 would be a critical molecule for control of tumoral progression. In addition to the in vitro experiments, WDR34 negativity was correlated with tumoral growth of OSCCs. Our findings suggested that WDR34 inhibits OSCC progression and might be a potential tumor-suppressor molecule in OSCCs.

Rotavirus infections in domestic animals

Rotaviruses are major enteric pathogens of humans and a wide variety of animals. Rotavirus infections have a worldwide prevalence. The viral genome is composed of 11 double-stranded RNA segments with six structural and five or six non-structural proteins. Over 35,000 strains have been identified and classified into five main (A, B, C, D, E) and three additional tentative (F, G, H) serotype groups. A binary classification system has been proposed defining ‘G’ or ‘P’ types, with at least 27 G and 35 P genotypes reported thusfar. The virus is transmitted primarily by the faecal-oral and oral routes. After attachment, entry into the host cells occurs through direct entry, fusion or endocytosis. Main mechanisms of Rotavirus-induced diarrhoea involve extensive enterocyte losses and nutrient disdigestion and malabsorption. Clinical features of Rotavirus infections range from asymptomatic infections to fulminant disease leading to rapid death.In calves, lambs and kids, piglets and foals, salient sign of the disease is diarrhoea; diarrhoeic faeces are white, yellow or, in severe cases, blood-tinted or frank haemorrhagic. In dogs and cats, the infection occurs usually as self-limiting diarrhoea. Avian Rotavirus infections are characterized by enteritis, growth depression and/or growth retardation. Definitive diagnosis of the infection can only be achieved by laboratory tests, including electron microscopic examination, immunohistochemical examination, immunofluorescence, ELISA, latex agglutination and molecular techniques. There is no specific treatment against Rotavirus infections. Treatment is based in providing supportive care and managing clinical signs and potential complications. Effective vaccines, containing inactivated, recombinant or attenuated strains of the virus, are available. Challenge studies have shown the ease of the virus in cross-infecting various animal species; animal strains of the virus may cross species and infect humans. Due to the ability of the virus to overcome species barriers, animal strains may act as natural source of viral genomes, promoting mutations and creating new viral genotypes, whose virulence cannot be predictable.

Evidence for depressed growth of juvenile Pacific salmon (Oncorhynchus) in Johnstone and Queen Charlotte Straits, British Columbia

AbstractJuvenile salmon traveling northwestward to the Pacific Ocean from the Strait of Georgia migrate through and take residence in both Johnstone and Queen Charlotte Straits. Johnstone Strait is a narrow and deep passage that is tidally mixed daily, resulting in a nearly isothermal water column, surface to the bottom (approximately 250 m). The trophic gauntlet hypothesis (McKinnell, Curchitser, Groot, Kaeriyama, &amp; Trudel, ) suggests that Johnstone Strait provides a poor growth environment for fish required to transit this area during their migration, due to the oceanographic conditions found there. Using insulin‐like growth factor‐1 (IGF1), a hormone used to assess short‐term growth (within 5–7 days) in fishes, growth was measured in individual juvenile salmon from five species in the Northern Strait of Georgia, Johnstone Strait, Queen Charlotte Strait, and Queen Charlotte Sound in the summer of 2012, 2013, and 2014. All five juvenile salmon species had significantly lower IGF1 concentration in both Johnstone and Queen Charlotte Straits as compared to the Northern Strait of Georgia. These results are consistent with some aspects of the tropic gauntlet hypothesis as growth of juvenile salmon in both Johnstone and Queen Charlotte Straits were significantly lower than found in the Northern Strait of Georgia across all salmon species and all years. In addition, these results demonstrate the utility of growth indices for assessing the effects of environmental variation on juvenile salmon in the presence of a strong ecological driver.

Interactions between arbuscular mycorrhizal fungi and exotic grasses differentially affect the establishment of seedlings of early- and late-successional woody species

The survival and growth of seedlings of woody species belonging to early- and late-successional stages are differentially affected by competition with the root system of Urochloa brizantha. Three trials were conducted to clarify such effect. First, seedlings of early- and late-successional woody species were grown in competition with the root system of U. brizantha. All seedlings of late-successional species survived and grew, and their ability to tolerate the competition was attributed to their long and thick roots. All seedlings of early-successional species died under competition, but 30–40 days earlier when the grass was mycorrhizal, compared with the non-mycorrhizal grass. The grass’ root system seems to use the arbuscular mycorrhizal fungi (AMF) hyphae network to increase its competitiveness with the woody seedlings, reducing their lifetime. In the second trial, AMF showed to be vital for three fast-growing exotic grasses (U. brizantha, Megathyrsus maximus, and Paspalum notatum) grown in a low-fertility soil. Conversely, in a high-fertility soil, the non-mycorrhizal grasses produced three-times more shoot dry mass than mycorrhizal grasses. The growth depression of mycorrhizal grasses was attributed to the carbon drain for AMF maintenance. In the third trial, we excluded the effect of U. brizantha root competition using a steel mesh that allowed the passage of only AMF hyphae. Seedlings of early- and late-successional woody species were grown around non-mycorrhizal and mycorrhizal U. brizantha which roots were confined within the steel mesh. The AMF hyphae associated to U. brizantha passed through the net and colonized the woody seedling roots, forming a common mycorrhizal network (CMN). The seedlings of early-successional woody species grew three-times more without CMN, suggesting that the CMN associated with the root grass increased the competition and anticipated the seedlings death, as observed in the first trial. Conversely, the seedlings of late-successional woody species were not affected by the CMN. Fine root traits of the early- and late-successional woody species can explain the differences in seedlings establishment during below-ground competition with U. brizantha, whereas the AMF increase the competitiveness of the grass and make harder the survival and establishment of early-successional woody seedlings.

A systematic review of exercise and psychosocial rehabilitation interventions to improve health-related outcomes in patients with bladder cancer undergoing radical cystectomy

Objective: Summarizing the evidence on the effects of pre- and postoperative exercise and psychosocial rehabilitation interventions on patient-reported outcomes (PROs) and physical fitness in bladder cancer patients undergoing radical cystectomy. Data sources: The Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Web of Science and the Physiotherapy Evidence Database were searched independently by two authors from inception until 10 November 2017. Cited references of the studies and citing references retrieved via Web of Science were also checked. Review methods: Randomized controlled trials (RCTs) and non-randomized studies assessing effects of exercise and psychosocial interventions in bladder cancer patients undergoing radical cystectomy were eligible. Primary outcome measures were PROs and physical fitness. Risk of bias was assessed using the Cochrane Collaboration tool and the Newcastle–Ottawa Scale. Results: Five RCTs (three exercise and two psychosocial studies) and one non-randomized psychosocial study comprising 317 bladder cancer patients were included. Timing of the intervention was preoperative (n = 2), postoperative (n = 2) or both pre- and postoperative (n = 2). Positive effects of exercise were found for physical fitness (n = 3), some health-related quality-of-life (HRQoL) domains (n = 2), personal activities in daily living (n = 1) and muscle strength (n = 1). Psychosocial interventions showed positive effects on anxiety (n = 1), fatigue (n = 1), depression (n = 1), HRQoL (n = 1) and posttraumatic growth (n = 1). Quality assessment showed most shortcomings with sample sizes and strong heterogeneity was observed between studies. Conclusion: The evidence relating to the effects of exercise in bladder cancer is very limited and is even less for psychosocial interventions.