bluuebunny/crossref_metadata_2025 huggingface dataset:
Advancing the physical activity curriculum at the collegiate level
Authors: Warren Bradley (BJ) , Odenheimer Brin Eleanor
Published: April 2017

Purpose

The purpose of this paper is to assess college students’ pre- and post- health-related, fitness levels, as determined by the American College of Sports Medicine’s (ACSM) five components of fitness, in a one-credit, graded college course and to objectively measure any differences between those pre- and post- health-related fitness levels.

Design/methodology/approach

In a field setting, the investigators conducted health-related, fitness assessments using the ACSM validated protocols. In addition, descriptive statistics were collected including demographic information, such as, age and sex.

Findings

Paired-sample t tests were used to calculate the pre- and post-test scores for six fitness- and health-related categories across four semesters. There were statistically significant (p<0.001) improvements in six different areas in each of the four semesters with the exception of the resting heart rate and VO2 Max measurements in the fall semester of 2014.

Originality/value

This study builds upon the current body of work tracking trends in physical activity, college courses. The results answer health promotion scientists’ call for more research on the implementation and evaluation of programmatic interventions (Domitrovich and Greendberg, 2000; Durlack, 1998; Durlak and DuPre, 2008) “in real-world settings in order to understand if and how an intervention works” (Søvik et al., 2016, p. 238). This results in addressing a research gap in assessing the effectiveness of physical activity courses in higher education (Keating et al., 2005).
How do we keep them coming back? A look at individual factors impacting attendee satisfaction and intention to return to festivals
Authors: Pope Jennifer Angela , Isely Paul , Agbetunsin Busuyi
Published: April 2017

Purpose

The purpose of this paper is to analyze the factors that influence the level of satisfaction or festival attendees and how that influences their intention to return. The impact of other factors such as past attendance and distance traveled to the festival were also examined.

Design/methodology/approach

The data for this study were collected using an online survey from attendees at a LaughFest™, a comedy festival hosted as a fund and awareness raiser for a non-profit organization (NPO) in a medium-sized Midwestern city. The data related to reasons for level of satisfaction and intention to return were coded into dichotomous variables, and along with income, gender and distance traveled to the event were analyzed using logistic regression.

Findings

Of the factors that impacted satisfaction, performers, venue, and ticket prices were found to have the largest impact on intention to return, with negative experiences having a greater impact than positive. Previous attendance was also significant with regard to intention to return.

Practical implications

This information will allow this festival’s managers to target specific areas for improvement to increase the rate of repeat attendance.

Originality/value

This paper aims to contribute to the literature addressing specific factors influencing level of satisfaction and how those factors impact intention to return by examining them in a comedy festival that is also a fund and awareness raiser for a local NPO. There are few studies examining this aspect in regard to this particular type of festival.
Determinants of job satisfaction in a lean environment
Authors: Rodríguez Denise , Van Landeghem Hendrik , Lasio Virginia , Buyens Dirk
Published: April 2017

Purpose

The purpose of this paper is to analyze the situational and dispositional determinants of job satisfaction in environments created by implementing employee-supportive lean.

Design/methodology/approach

The research uses a questionnaire to measure the determinants of job satisfaction (perceived job demands, perceived job autonomy and core self-evaluations) and job satisfaction. Afterwards, the paper proposes a conceptual framework and uses hierarchical multiple regression to test the relationships among perceived job demands, perceived job autonomy, core self-evaluations and job satisfaction. Additionally, the study describes the implementation of employee-supportive lean in four small companies using an action research approach.

Findings

The findings reveal that perceived job demands has a negative impact on job satisfaction. In addition, the authors find that perceived job autonomy and core self-evaluations have a positive impact on job satisfaction. Finally, the results show that core self-evaluations buffer the impact of perceived job demands on job satisfaction.

Originality/value

The present research underscores the importance of work and personal characteristics for employees’ job satisfaction in an environment created by implementing employee-supportive lean.
Six Sigma project selections: a critical review
Authors: Padhy Ramakrushna
Published: April 2017

Purpose

The paper aims to review the literature on Six Sigma projects through a broad framework of Six Sigma project selection process. It proposes a process framework approach of six sigma project selection and enumerates various recent tools and methods required for each stage. The review aims to expand the domain of Six Sigma project selection by identifying the importance of project portfolio approach.

Design/methodology/approach

The study used a process framework approach and systematic literature review to identify and classify various literature pertaining six sigma projects and its associated tools and methods

Findings

The paper provides broad insights about the opportunity and direction to future research in the area of Six Sigma project. Emerging research opportunities exist in the area of Six Sigma project risk management and selecting portfolio of projects.

Research limitations/implications

The study has its own limitations because of its chosen research approach. The process framework developed for classification of literature is based on expert opinion. Further research can be carried out to validate it.

Practical implications

This study will benefit new researchers entering the field of Six Sigma to identify new research opportunities and issues for their research interest. Second, industry practitioners and consultants working in the area of Six Sigma may work towards more successful implementation of Six Sigma.

Originality/value

The paper fulfils an identified gap of review of Six Sigma project selection.
Impact of team members’ composition on construction projects delivery in selected higher institutions in Nigeria
Authors: Olatunde Nathaniel Ayinde , Ogunsemi Deji Rufus , Oke Ayodeji Emmanuel
Published: April 2017

Purpose

The purpose of this paper is to examine the effect of team members’ composition on cost and time of completion of construction projects in selected higher institutions with a view to improving construction project delivery in Nigeria.

Design/methodology/approach

The study used the purposive sampling technique to select two higher institutions out of six in the study area, and census survey was used in selecting 35 completed construction projects executed by the institutions within the time frame 2000 to 2013. A total of 191 questionnaires were distributed to obtain information from construction team members (quantity surveyors, architects, structural/civil engineers, services engineers, contractors and clients) who participated in the selected construction projects. Mean item score and Kendall’s test were used in examining team members’ composition, while the relationship between team members’ composition and construction cost and time was tested usingt-test and eta-squared.

Findings

The results revealed that construction team members’ composition has a significant impact on the completion time of construction projects, though with small magnitude, while the impact of construction team members’ composition on construction cost is not significant. Also, it was revealed that some team members did not play any team role due to the fact that the main criterion for team members’ composition was knowledge, skill and abilities (KSA).

Practical implications

The study finally recommended that a deliberate effort should be made in studying and ascertaining the team role every construction team member will play before appointing them to be member of a team, as improper team members’ composition could hamper effective construction project delivery in terms of completion time.

Originality/value

The study is an attempt to discourage the traditional construction team members’ selection system which was based on KSAs, which is deficient under team environment.
Augmented reality, virtual reality and 3D printing for the co-creation of value for the visitor experience at cultural heritage places
Authors: Jung Timothy Hyungsoo , tom Dieck M. Claudia
Published: April 2017

Purpose

This paper aims to propose a value co-creation framework through examining the opportunities of implementing augmented reality, virtual reality and 3D printing into the visitor experience at cultural heritage places.

Design/methodology/approach

This study proposes the conceptual model of value co-creation using a case-study approach by presenting some cases of a cultural heritage place in the UK.

Findings

The findings of this study suggest that the effective use of multiple technologies in the context of cultural heritage places contributes to the co-creation of value for both cultural heritage organisations and also for visitors’ pre-visit, onsite and post-visit experience. Businesses can benefit from increased spending, intention to return and positive word-of-mouth, while visitors receive a personalised, educational, memorable and interactive experience.

Practical implications

Cultural heritage places have to find new ways to survive increasingly fierce competition. Using technology and the concept of value co-creation can prove to be a valuable concept in an attempt to attract new target markets, enhance visitors’ experience, create positive word-of-mouth and revisit intentions.

Originality/value

Recently, increased importance has been placed on the co-creation of value to account for consumers' interest in playing some part in the development of services and products. This study takes a holistic approach using augmented reality, virtual reality and 3D printing from a value co-creation perspective.
Ethylene detection using TiO2–WO3 composite sensor for fruit ripening applications
Authors: Kathirvelan Jayaraman , Vijayaraghavan Rajagopalan , Thomas Anna
Published: April 2017

Purpose

The purpose of this paper was to develop a chemo-resistive sensor based on TiO2–WO3 composite material to detect and estimate ethylene released from the fruit ripening process to ensure food safety.

Design/methodology/approach

The ethylene sensor has been fabricated using TiO2–WO3 composite material through the sol-gel method.

Findings

The sensitivity of the sensor obtained using the pre-calibrated ethylene is found to be 46.2 per cent at 200 ppm ethylene concentration, and the proposed sensor could measure 8 ppm as the lowest concentration.

Originality/value

The sensor was tested for continuous ethylene detection during natural ripening of fruits and hence is useful for ensuring food safety through discrimination of the type of fruit ripening. A TiO2–WO3 composite ethylene sensor is developed for the first time.
The release of pro‐inflammatory cytokines is mediated via mitogen‐activated protein kinases rather than by the inflammasome signalling pathway in keratinocytes
Authors: Ondet Thomas , Muscatelli‐Groux Béatrice , Coulouarn Cédric , Robert Sacha , Gicquel Thomas , Bodin Aude , Lagente Vincent , Grimaud Jean‐Alexis
Published: April 2017

Toll‐like receptors (TLRs) are expressed in the skin and airway epithelial tissues, which are the most important sites of host–pathogen interactions. TLRs recognize the 3‐D structures of pathogen‐associated molecules and are therefore useful markers of the innate immune response. Here, we investigated the role of lipopolysaccharides and monosodium urate (MSU) crystals in the activation of the TLR and NOD‐like receptor (NLR) pathways in human keratinocytes. Analysis of the inflammasome compounds revealed that NOD‐like receptor P3 and TLR4, both of which are components of inflammasome complexes involved in the activation of interleukin (IL)‐1β, were not expressed in keratinocytes. Transcriptomic analysis showed that the combination of MSU and lipopolysaccharide priming did not elicit significant results compared to MSU treatment, which induced the expression of TLR2, IL‐6 and IL‐8/chemokine (C‐X‐C motif) ligand 8 CXCL8 in the keratinocyte cell line HaCaT. Furthermore, MSU promoted the phosphorylation of extracellular signal‐regulated kinase 1/2 and MAPK14/p38α mitogen‐activated protein kinases. We concluded that MSU stimulates a pro‐inflammatory response in keratinocytes via mitogen‐activated protein kinase pathway to induce production of IL‐8/CXCL8 chemokine (C‐X‐C motif) ligand 8 and TLR2.
Successful long‐term maintenance following Nutrition Care Process Terminology implementation across a state‐wide health‐care system
Authors: Vivanti Angela , O'Sullivan Therese A. , Porter Jane , Hogg Marion
Published: April 2017

Aim

Three years following a state‐wide Nutrition Care Process Terminology (NCPT) implementation project, the present study aimed to (i) assess changes in NCPT knowledge and attitudes, (ii) identify implementation barriers and enablers and (iii) seek managers’ opinions post‐implementation.

Methods

Pre‐implementation and three years post‐implementation, all Queensland Government hospitals state‐wide were invited to repeat a validated NCPT survey. Additionally, a separate survey sought dietetic managers’ opinions regarding NCPT’s use and acceptance, usefulness for patient care, role in service planning and continued use.

Results

A total of 238 dietitians completed the survey in 2011 and 82 dietitians in 2014. Use of diagnostic statement in the previous six months improved (P < 0.001). Perceptions of NCPT’s importance (P < 0.020) and benefits of incorporating NCPT into practice (P = 0.029) increased. Time to complete NCPT documentation (P < 0.013) and access to mentors decreased (P < 0.001).

Other areas including enhanced attitudes, familiarity, confidence, views, knowledge and incorporation into practice were sustained (P > 0.05). Key elements in sustaining NCPT implementation over three years included ongoing management support, workshops/tutorials, discussion and mentor and peer support. The most valued resources were pocket guides, ongoing workshops/tutorials and mentor support. Dietetic managers held many positive NCPT views, however, opinions differed around the usefulness of service planning, safer practice, improving patient care and facilitating communication. Some managers would not support NCPT unless it was recommended for practice.

Conclusions

Immediate improvements following the NCPT implementation project were sustained over three years. Moving forward, a professional focus on continuing to incorporate NCPT into standard practice will provide structure for process and outcomes assessment.
The influence of substance use on depressive symptoms among young adult black men: The sensitizing effect of early adversity
Authors: Kogan Steven M. , Cho Junhan , Oshri Assaf , MacKillop James
Published: April 2017

Background and Objectives

Depressive symptoms have been identified as an important consequence of substance use. Both heavy drinking and marijuana use have acute and short‐term effects on systems that regulate emotion, increasing the potential for substance use to induce problems with negative affect and irritability. We investigated the effects of alcohol and marijuana use on depressive symptoms among a sample of young Black men. We also tested the stress sensitization hypothesis that exposure to adverse childhood experiences would amplify the influence of substance use on men's depressive symptoms.

Methods

Hypotheses were tested with 505 rural Black men who, at ages 19–22 years, provided data on their substance use, adverse childhood experiences, and depressive symptoms; they provided data again 18 months later.

Results

Substance use forecasted increases in depressive symptoms; cross‐lagged analyses yielded no evidence for the inverse path, depressive symptoms increasing substance use. The impact of substance use on depressive symptoms was amplified among young Black men who were exposed to adverse childhood experiences. Substance use did not significantly predict depressive symptoms when adversity was low.

Discussion and Conclusions

Our findings suggest that, during young adulthood, substance use increases depressive symptoms among Black men who were exposed to childhood adversity. Because childhood adversity disproportionately affects Black men, these findings inform future cross‐group research designed to investigate racial disparities in the consequences of substance use.

Scientific Significance

Depressive symptoms may be understood as an effect as well as a cause of substance use, particularly among vulnerable young Black men. (Am J Addict 2017;26:400–406).
Protease‐activated receptor‐2 suppresses interleukin (IL)‐10 expression in B cells via upregulating Bcl2L12 in patients with allergic rhinitis
Authors: Xue J.‐M. , Yang L.‐T. , Yang G. , Geng X.‐R. , Liu Z.‐Q. , Wang S. , Zhao H.‐L. , Liu Z.‐G. , Zhao C.‐Q. , Yang P.‐C.
Published: April 2017

Background and aims

The function of interleukin (IL)‐10‐producing B cells (B10 cell) is compromised in patients with allergic diseases. Protease‐activated receptor (PAR)‐2 has immunoregulatory functions. This study aimed to elucidate the role of PAR2 in the suppression of IL‐10 expression in peripheral B cells.

Methods

Peripheral blood B cells were collected from patients with allergic rhinitis (AR). A correlation between the expression of Bcl2‐like protein 12 (Bcl2L12) and IL‐10 in the B cells was analyzed. An AR mouse model was developed.

Results

We observed that the expression of IL‐10 was lower in the peripheral B cells from patients with airway allergy. A negative correlation was identified between the expression of IL‐10 and PAR2 in B cells. Activation of PAR2 of B cells increased the expression of Bcl2L12 and suppression of LPS‐induced IL‐10 expression, which were inhibited by knocking down the Bcl2L12 gene. Treating B cells from AR patients with Bcl2L12‐shRNA‐carrying liposomes reversed the capability of IL‐10 expression and the immunosuppressive function. Administration of Bcl2L12 shRNA‐carrying liposomes attenuated experimental AR in mice.

Conclusions

Activation of PAR2 inhibits the expression of IL‐10 in B cells, which can be reversed by treating B cells with Bcl2L12 shRNA‐carrying liposomes. The data suggest that regulation of Bcl2L12 may be a novel approach in the treatment for AR.
A Note on Marginalization of Regression Parameters from Mixed Models of Binary Outcomes
Authors: Hedeker Donald , du Toit Stephen H. C. , Demirtas Hakan , Gibbons Robert D.
Published: April 2017

This article discusses marginalization of the regression parameters in mixed models for correlated binary outcomes. As is well known, the regression parameters in such models have the “subject-specific” (SS) or conditional interpretation, in contrast to the “population-averaged” (PA) or marginal estimates that represent the unconditional covariate effects. We describe an approach using numerical quadrature to obtain PA estimates from their SS counterparts in models with multiple random effects. Standard errors for the PA estimates are derived using the delta method. We illustrate our proposed method using data from a smoking cessation study in which a binary outcome (smoking, Y/N) was measured longitudinally. We compare our estimates to those obtained using GEE and marginalized multilevel models, and present results from a simulation study.
The influence of flow on learning outcomes: An empirical study on the use of clickers
Authors: Buil Isabel , Catalán Sara , Martínez Eva
Published: April 2017

Flow is a state of total absorption and concentration in an activity that is desirable for students, as it enhances the learning experience. Due to the importance of flow for learning, this research investigates the influence of three flow preconditions—namely balance of skill and challenge, feedback and goal clarity—on students' flow, operationalized as heightened concentration, sense of control and autotelic experience, while using clickers—a type of polling device. The study also explores the impact of concentration, sense of control and autotelic experience on students' perceived learning and satisfaction. Based on a survey of 204 undergraduate students who use clickers in the classroom, the findings show that balance of skill and challenge has a positive influence on students' concentration, sense of control and autotelic experience. Both feedback provided by clickers and goal clarity have a positive influence on concentration and sense of control, but do not influence the autotelic experience. Findings also corroborate the positive impact of concentration and sense of control experienced by students on perceived learning. Finally, autotelic experience predicts both perceived learning and satisfaction.
Health‐related quality of life outcomes from a contemporary prostate cancer registry in a large diverse population
Authors: Chien Gary W. , Slezak Jeff M. , Harrison Teresa N. , Jung Howard , Gelfond Joy S. , Zheng Chengyi , Wu Edward , Contreras Richard , Loo Ronald K. , Jacobsen Steven J.
Published: April 2017

Objective

To assess the health‐related quality of life (HRQoL) of patients with prostate cancer up to 24 months after treatment in a contemporary large diverse population.

Patients and Methods

Patients with newly diagnosed prostate cancer from March 2011 to January 2014 in our healthcare system were included. The Expanded Prostate Cancer Index Composite (EPIC‐26) questionnaire was administered before treatment, and at 1, 3, 6, 12, 18, and 24 months after treatment up to November 2014 for all methods of treatment. The Kruskall–Wallis test was used to compare the distribution of each EPIC‐26 domain score at each time point, and mixed models were used to assess the overall scores over the period after treatment.

Results

In all, 5 727 patients were included. There were data for 3 422, 2 329, 2 017, 1 922, 1 772, 1 260, and 837 patients before treatment, and at 1, 3, 6, 12, 18, and 24 months after treatment, respectively. At 1 month, bowel scores were the lowest for patients that had had radiation therapy, and urinary irritative symptoms were the lowest for those who had had brachytherapy. There were sexual function declines for all the treatment methods, with surgery having the steepest decline; open radical prostatectomy (ORP) had a greater decline than robot‐assisted laparoscopic prostatectomy (RALP). Patients who underwent RALP had a better return of sexual function, approaching that of brachytherapy and radiation therapy at 24 months. Urinary incontinence (UI) also declined the most in surgical patients, with RALP patients improving slightly more than ORP patients at 12–24 months.

Conclusions

Patients' HRQoL after prostate cancer treatment varies by treatment method. Notably, sexual function recovers most for RALP patients. UI remains worse at 24 months after surgery, compared to other methods of prostate cancer treatment.
Lifestyle use of drugs by healthy people for enhancing cognition, creativity, motivation and pleasure
Authors: d'Angelo L‐S Camilla , Savulich George , Sahakian Barbara J
Published: April 2017

Today, there is continued, and in some cases growing, availability of not only psychoactive substances, including treatments for mental health disorders such as cognitive enhancers, which can enhance or restore brain function, but also ‘recreational’ drugs such as novel psychoactive substances (NPS). The use of psychoactive drugs has both benefits and risks: whilst new drugs to treat cognitive symptoms in neuropsychiatric or neurodegenerative disorders could have great benefits for many patient groups, the increasing ease of accessibility to recreational NPS and the increasing lifestyle use of cognitive enhancers by healthy people means that the effective management of psychoactive substances will be an issue of increasing importance. Clearly, the potential benefits of cognitive enhancers are large and increasingly relevant, particularly as the population ages, and for this reason, we should continue to devote resources to the development of cognitive enhancers as treatments for neurodegenerative diseases and psychiatric disorders, including Alzheimer's disease, attention deficit hyperactivity disorder and schizophrenia. However, the increasing use of cognitive enhancers by healthy individuals raises safety, ethical and regulatory concerns, which should not be ignored. Similarly, understanding the short‐ and long‐term consequences of the use of NPS, as well as better understanding the motivations and profiles of users could promote more effective prevention and harm reduction measures.

Linked Articles

This article is part of a themed section on Pharmacology of Cognition: a Panacea for Neuropsychiatric Disease? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.19/issuetoc
Neural tube defects: Risk factors and preventive measures
Authors: Kondo Atsuo , Matsuo Takuya , Morota Nobuhito , Kondo Atsuya S. , Okai Ikuyo , Fukuda Hiromi
Published: April 2017

For the last 25 years, it has been proven that the occurrence or recurrence of neural tube defects can be prevented with the administration of folic acid before and early pregnancy. At present, over 80 countries in the world, except Japan, have mandated the fortification of wheat flour and/or rice with folic acid, which has resulted in a significant reduction in the prevalence of neural tube defects. In 2000, the Japanese government recommended folic acid 400 μg daily for young women of childbearing age and women who are planning to conceive. In 2002, the government started to present information about the importance of folic acid in the development of fetuses in the Mother‐Child Health Booklet annually. Despite these endeavors, the prevalence of neural tube defects has remained unchanged. We discuss the risk factors of neural tube defects and propose preventive measures to decrease the number of neonates with neural tube defects. We believe that the government should implement the fortification of staple food with folic acid very soon, which will eventually decrease not only the neonatal mortality and morbidity, but also the economic burden on our health care system.
Children's Perspectives on Happiness and Subjective Well‐being in Preschool
Authors: Koch Anette Boye
Published: April 2017

Photo‐elicited interviews indicate that children hardly ever mention educators when asked about elements in preschool that make them feel happy. Happiness is found to occur in activities in the ‘underlife’ of the ECEC institution. Children challenge adult rules and norms in order to create status in the peer‐group, while at the same time, they seek to construct social identity and maintain a positive relationship with their educators. A child that manages to balance both adult expectations and what is needed to participate in the underlife among peers, experiences happiness and thus, is in a good state of well‐being.
Understanding the effects of different social data on selecting priority conservation areas
Authors: Karimi Azadeh , Tulloch Ayesha I.T. , Brown Greg , Hockings Marc
Published: April 2017

Conservation success is contingent on assessing social and environmental factors so that cost‐effective implementation of strategies and actions can be placed in a broad social–ecological context. Until now, the focus has been on how to include spatially explicit social data in conservation planning, whereas the value of different kinds of social data has received limited attention. In a regional systematic conservation planning case study in Australia, we examined the spatial concurrence of a range of spatially explicit social values and land‐use preferences collected using a public participation geographic information system and biological data. We used Zonation to integrate the social data with the biological data in a series of spatial‐prioritization scenarios to determine the effect of the different types of social data on spatial prioritization compared with biological data alone. The type of social data (i.e., conservation opportunities or constraints) significantly affected spatial prioritization outcomes. The integration of social values and land‐use preferences under different scenarios was highly variable and generated spatial prioritizations 1.2–51% different from those based on biological data alone. The inclusion of conservation‐compatible values and preferences added relatively few new areas to conservation priorities, whereas including noncompatible economic values and development preferences as costs significantly changed conservation priority areas (48.2% and 47.4%, respectively). Based on our results, a multifaceted conservation prioritization approach that combines spatially explicit social data with biological data can help conservation planners identify the type of social data to collect for more effective and feasible conservation actions.
THE IMPACT OF EXPORTING AND FOREIGN DIRECT INVESTMENT ON PRODUCT INNOVATION: EVIDENCE FROM CHINESE MANUFACTURERS
Authors: Olabisi Michael
Published: April 2017

To understand the drivers of product innovation at the firm level, I compare the effects of foreign direct investment (FDI) and exporting on product innovation using a rich firm‐level database of manufacturing and industrial enterprises. The article focuses on product innovation, as it is vital to economic development. Estimates from linear regressions and propensity score matching tests show that learning‐by‐exporting is a stronger predictor of product innovation. Firms that receive foreign investment also tend to engage in more product innovation, but not at the same level as the firms that export. Additional tests confirm that as they start and stop exporting, firms change their patterns of investment in the drivers of product innovation—fixed capital and research. (JEL D22, F14, F23, L25, O31)
Interactive effects of nitrate concentrations and carbon dioxide on the stoichiometry, biomass allocation and growth rate of submerged aquatic plants
Authors: Dülger Emin , Heidbüchel Patrick , Schumann Tobias , Mettler‐Altmann Tabea , Hussner Andreas
Published: April 2017

The partial pressure of carbon dioxide (CO2) in freshwater ecosystems is likely to be affected by climate change, but little is known of its potential effects on aquatic plants when interacting with other stressors such as nitrate pollution.

We set a laboratory experiment to test the effects of CO2 and nitrate availability on growth, biomass allocation, chlorophyll content, and nitrogen, carbon and starch content in four species of submerged aquatic plants. Plants were grown under low CO2 (0.02 mm CO2 and 0.83 mm HCO3−) and high CO2 (0.33 mm CO2 and 0.54 mm HCO3−) at five nitrate concentrations (0.1, 0.5, 1, 2 and 4 mg N/L).

Growth rates were stimulated in all species by increasing nitrogen and CO2 availability. Leaf dry matter content (LDMC), leaf starch content and biomass allocation to roots increased with increasing CO2, but decreased with increasing nitrogen availability.

Leaf chlorophyll and nitrogen content in roots and leaves were significantly higher in the low than in the high CO2 treatments, and generally increased with increasing nitrogen availability. The starch content of leaves correlated positively with LDMC, but negatively with chlorophyll content.

There were strong interactive effects of CO2 and nitrogen availability on plant growth parameters, tissue nitrogen, chlorophyll and starch content. CO2 availability had a stronger effect on biomass allocation to roots than nitrogen. The effects of CO2 on LDMC, tissue nitrogen, starch and chlorophyll content were more pronounced under low than under high nitrogen concentration.

Our laboratory study suggests that changes in the composition of dissolved inorganic carbon driven by climate change can interact with environmental stressors such as nitrate pollution and affect growth, biomass allocation and physiology of submerged aquatic plants. This is likely to have significant implications for the structuring role of macrophytes in freshwater ecosystems.
Vertical and seasonal distribution of picoplankton and functional nitrogen genes in a high‐altitude warm‐monomictic tropical lake
Authors: Pajares Silvia , Merino‐Ibarra Martín , Macek Miroslav , Alcocer Javier
Published: April 2017

The nitrogen (N) cycle is highly dependent on microbial processes. Distribution of these communities is one of the most important factors in the variation of the N cycling in warm‐monomictic lakes. However, the effects of the alternation of water stratification and mixing periods on the ecology of microbial communities involved in these processes are rarely studied in this type of aquatic ecosystem.

We explored vertical and seasonal patterns of picoplankton and the genetic potential for ammonium oxidation (amoA gene for bacteria and archaea), denitrification (nirS and nirK), anammox (hzsA), and DNRA (nrfA) and their relationships with the main limnological variables in Lake Alchichica (Central Mexican Plateau) to provide insight into the distribution and importance of these planktonic communities in warm‐monomictic tropical lakes. Ten depths were sampled during late stratification (November 2015) and mixing (February 2016) periods, covering the epilimnion, metalimnion (oxycline), and hypolimnion layers in the first case.

We showed that temperature and oxygen stratification shaped the distribution of picoplankton and functional N genes in this lake. These communities also varied in relation to nutrient availability and underwent temporal changes throughout the water column. The amoA genes, along with autotrophic picoplankton, were more abundant during the stratification, indicating that nitrification could be potentially more important during this period, mainly at the oxycline layer. Denitrifying genes showed strong variations during the stratification period, with highest gene copy numbers at the oxycline and hypolimnion layers. Anoxic conditions were characterised by a relative increase in the abundance of the nrfA gene with depth, which was positively correlated with NH4+ concentration. On the other hand, the hzsA gene was not detected in any sample.

Our findings highlight the importance of thermal stratification as one of the main factors influencing the genetic potential for N transformations within the water column in warm‐monomictic tropical lakes.
Differences in xylem and leaf hydraulic traits explain differences in drought tolerance among mature Amazon rainforest trees
Authors: Powell Thomas L. , Wheeler James K. , de Oliveira Alex A. R. , da Costa Antonio Carlos Lola , Saleska Scott R. , Meir Patrick , Moorcroft Paul R.
Published: April 2017

Considerable uncertainty surrounds the impacts of anthropogenic climate change on the composition and structure of Amazon forests. Building upon results from two large‐scale ecosystem drought experiments in the eastern Brazilian Amazon that observed increases in mortality rates among some tree species but not others, in this study we investigate the physiological traits underpinning these differential demographic responses. Xylem pressure at 50% conductivity (xylem‐P50), leaf turgor loss point (TLP), cellular osmotic potential (πo), and cellular bulk modulus of elasticity (ε), all traits mechanistically linked to drought tolerance, were measured on upper canopy branches and leaves of mature trees from selected species growing at the two drought experiment sites. Each species was placed a priori into one of four plant functional type (PFT) categories: drought‐tolerant versus drought‐intolerant based on observed mortality rates, and subdivided into early‐ versus late‐successional based on wood density. We tested the hypotheses that the measured traits would be significantly different between the four PFTs and that they would be spatially conserved across the two experimental sites. Xylem‐P50, TLP, and πo, but not ε, occurred at significantly higher water potentials for the drought‐intolerant PFT compared to the drought‐tolerant PFT; however, there were no significant differences between the early‐ and late‐successional PFTs. These results suggest that these three traits are important for determining drought tolerance, and are largely independent of wood density—a trait commonly associated with successional status. Differences in these physiological traits that occurred between the drought‐tolerant and drought‐intolerant PFTs were conserved between the two research sites, even though they had different soil types and dry‐season lengths. This more detailed understanding of how xylem and leaf hydraulic traits vary between co‐occuring drought‐tolerant and drought‐intolerant tropical tree species promises to facilitate a much‐needed improvement in the representation of plant hydraulics within terrestrial ecosystem and biosphere models, which will enhance our ability to make robust predictions of how future changes in climate will affect tropical forests.
Comparison of Fused Glass Beads and Pressed Powder Pellets for the Quantitative Measurement of Al, Fe, Si and Ti in Bauxite by Laser‐Induced Breakdown Spectroscopy
Authors: Carvalho Alexandrina A. C. , Alves Victoria C. , Silvestre Daniel M. , Leme Flávio O. , Oliveira Pedro V. , Nomura Cassiana S.
Published: April 2017

Due to matrix interference and sample particle size effects, some of the most important and difficult issues in laser‐induced breakdown spectroscopy (LIBS) analysis are the calibration and quantitative measurement of a complex matrix. This study proposes the use of borate fusion as an alternative sample preparation procedure for the quantitative measurement of Al, Fe, Si and Ti in bauxite by LIBS. Analytical calibration curves were made using bauxite certified reference materials (CRM), and the precision and accuracy of the methods were evaluated by analysing an additional bauxite CRM, using two different approaches: pressed powder pellets and fused glass beads. The borate fusion method was the most suitable sample preparation technique, since particle size effects and matrix interference could be minimised, obtaining better linearity on the analytical calibration curves (r2), and more accurate and more precise results for bauxite analysis.
Survival comparisons of intensive vs. conventional hemodialysis: Pitfalls and lessons
Authors: Miller Amanda J. , Perl Jeff , Tennankore Karthik K.
Published: April 2017

The optimal dose of hemodialysis (HD) has not yet been established. As a means of better approximating the physiology of native kidney function, there has been a growing interest in intensive HD (an increase in dialysis frequency and/or duration). Although many studies have demonstrated a survival benefit with intensive dialysis, results have been conflicting. This controversy stems from the challenges of randomizing patients to conventional vs. intensive HD modalities and, therefore, the reliance on observational comparisons that have been limited by varying definitions for intensive dialysis, differences in dialysis location and prescription, unavoidable treatment selection bias, and a potential lack of generalizability. This review will discuss the pitfalls and complexities surrounding survival comparisons with intensive HD, and identify important directions for future study.
Ascorbic acid triggered physiochemical transformations at different phenological stages of heat‐stressed Bt cotton
Authors: Kamal M. A. , Saleem M. F. , Shahid M. , Awais M. , Khan H. Z. , Ahmed K.
Published: April 2017

Heat stress at reproductive stages of cotton crop is the main cause for instability in yield than other abiotic stresses of crops. An experiment was conducted to observe the impacts of heat stress at squaring and flowering stages of cotton and potential of exogenously applied ascorbic acid to alleviate this stress. The experiment was planted for two consecutive years, that is 2013 and 2014, in randomized complete block design with split plot arrangement having three replications. Treatments were comprised of heat stress in main plots, viz. H0 = no heat imposition; H1 = heat imposition at square initiation; H2 = heat imposition at flower initiation and foliar‐applied ascorbic acid in subplots, viz. A0 = control or water spray; A1 = 20 mg/L; A2 = 40 mg/L; and A3 = 60 mg/L. Results showed that heat stress badly affected plant water relations (relative water contents and osmotic potential), total chlorophyll contents and activities of antioxidant enzymes that led to a corresponding decrease in seed cotton yield. Foliar application of ascorbic acid (40–60 mg/L) ameliorated adverse effects of heat and thus helped the crop to improve its water relations, stay green and antioxidant enzymes resulting into better crop yield.
Microstructural evolution, non‐Ohmic properties, and giant dielectric response in CaCu3Ti4−xGexO12 ceramics
Authors: Boonlakhorn Jakkree , Thongbai Prasit , Putasaeng Bundit , Kidkhunthod Pinit , Maensiri Santi , Chindaprasirt Prinya
Published: April 2017

The microstructural evolution, non‐Ohmic properties, and giant dielectric properties of CaCu3Ti4−xGexO12 ceramics (x=0‐0.10) are systematically investigated. The Rietveld refinement confirms the existence of a pure CaCu3Ti4O12 phase in all samples. Significantly enlarged grain sizes of CaCu3Ti4−xGexO12 ceramics are associated with the liquid phase sintering mechanism. Enhanced dielectric permittivity from 6.90×104 to 1.08×105 can be achieved by increasing Ge4+ dopant from x=0‐0.10, whereas the loss tangent is remarkably reduced by a factor of ≈10. Non‐Ohmic properties are enhanced by Ge4+ doping ions. Using impedance and admittance spectroscopies, the underlying mechanisms for the dielectric and nonlinear properties are well described. The improved nonlinear properties and reduced loss tangent are attributed to the enhanced resistance and conduction activation energy of the grain boundaries. The largely enhanced permittivity is closely associated with the enlarged grain sizes and the increase in the Cu+/Cu2+ and Ti3+/Ti4+ ratios, which are calculated from the X‐ray absorption near‐edge structure.
Contrasting dispersal histories of broad‐ and fine‐leaved temperate Loliinae grasses: range expansion, founder events, and the roles of distance and barriers
Authors: Minaya Miguel , Hackel Jan , Namaganda Mary , Brochmann Christian , Vorontsova Maria S. , Besnard Guillaume , Catalán Pilar
Published: April 2017

Aim

Successful colonization after long‐distance dispersal (LDD) depends on the availability of suitable habitats and competitive ability. In this study, we address the hypothesis that two widely distributed sister grass lineages (broad‐ and fine‐leaved Loliinae; hereafter BL and FL) that differ in their habitat requirements and competitive ability also differ in their biogeographic history, with particular reference to LDD.

Location

Global.

Methods

We reconstructed a comprehensive phylogeny of Loliinae, based on nuclear and plastid markers and estimated divergence times using fossil calibrations. Biogeographical events were estimated using analysis of range evolution, comparing different models. Numbers and rates of dispersals were estimated for BL and FL using stochastic mapping with best‐performing and baseline biogeographical models, and examined for correlation with distance, disjunction type, and phenotypic syndrome.

Results

The most recent common ancestor of Loliinae likely split at the Oligocene‐Miocene transition (22.50 ± 3.95 Ma), pre‐dating previous estimates, whereas the ancestors of the BL and FL Loliinae likely began to diversify in the Early Miocene (18.91 ± 4.15 and 17.50 ± 3.50 Ma, respectively). A model of range evolution integrating founder events and scaling of dispersal by shortest distance between areas performed best amongst a set of alternative models and recovered a mean of 83 dispersal events in Loliinae. Overall dispersal rates were significantly higher in BL than in FL. Per‐route dispersal rates showed a significant negative exponential relationship to shortest distance but were not affected by phenotypic syndrome or disjunction type.

Main conclusions

Loliinae originated in the Northern Hemisphere and evolved through recurrent LDDs. Higher competitive ability, potentially related to the broad‐leaved syndrome (i.e. tall strong‐rhizomatous plants, long‐living individuals, occupancy of more stable habitats), may explain higher observed dispersal rates in BL compared with FL Loliinae. However, the dominant factor impacting dispersal in both BL and FL Loliinae is the distance between suitable areas.
Geographic variation in mimetic precision among different species of coral snake mimics
Authors: Akcali C. K. , Pfennig D. W.
Published: April 2017

Batesian mimicry is widespread, but whether and why different species of mimics vary geographically in resemblance to their model is unclear. We characterized geographic variation in mimetic precision among four Batesian mimics of coral snakes. Each mimic occurs where its model is abundant (i.e. in ‘deep sympatry’), rare (i.e. at the sympatry/allopatry boundary or ‘edge sympatry’) and absent (i.e. in allopatry). Geographic variation in mimetic precision was qualitatively different among these mimics. In one mimic, the most precise individuals occurred in edge sympatry; in another, they occurred in deep sympatry; in the third, they occurred in allopatry; and in the fourth, precise mimics were not concentrated anywhere throughout their range. Mimicry was less precise in allopatry than in sympatry in only two mimics. We present several nonmutually exclusive hypotheses for these patterns. Generally, examining geographic variation in mimetic precision – within and among different mimics – offers novel insights into the causes and consequences of mimicry.
Influence of coral cover and structural complexity on the accuracy of visual surveys of coral‐reef fish communities
Authors: Coker D. J. , Nowicki J. P. , Graham N. A. J.
Published: April 2017

Using manipulated patch reefs with combinations of varying live‐coral cover (low, medium and high) and structural complexity (low and high), common community metrics (abundance, diversity, richness and community composition) collected through standard underwater visual census techniques were compared with exhaustive collections using a fish anaesthetic (clove oil). This study showed that reef condition did not influence underwater visual census estimates at a community level, but reef condition can influence the detectability of some small and cryptic species and this may be exacerbated if surveys are conducted on a larger scale.