Microbial activity and community diversity in a variable charge soil as affected by cadmium exposure levels and time

Effects of cadmium (Cd) on microbial biomass, activity and community diversity were assessed in a representative variable charge soil (Typic Aquult) using an incubation study. Cadmium was added as Cd(NO3)2> to reach a concentration range of 0～16 mg Cd/kg soil. Soil extractable Cd generally increased with Cd loading rate, but decreased with incubation time. Soil mi-crobial biomass was enhanced at low Cd levels (0.5～1 mg/kg), but was inhibited consistently with increasing Cd rate. The ratio of microbial biomass C/N varied with Cd treatment levels, decreasing at low Cd rate (<0.7 mg/kg available Cd), but increasing progressively with Cd loading. Soil respiration was restrained at low Cd loading (<1 mg/kg), and enhanced at higher Cd levels. Soil microbial metabolic quotient (MMQ) was generally greater at high Cd loading (1～16 mg/kg). However, the MMQ is also affected by other factors. Cd contamination reduces species diversity of soil microbial communities and their ability to metabolize different C substrates. Soils with higher levels of Cd contamination showed decreases in indicator phospholipids fatty acids (PLFAs) for Gram-negative bacteria and actinomycetes, while the indicator PLFAs for Gram-positive bacteria and fungi increased with increasing levels of Cd contamination.     

Electricity generation and brewery wastewater treatment from sequential anode-cathode microbial fuel cell

A sequential anode-cathode double-chamber microbial fuel cell (MFC), in which the effluent of anode chamber was used as a continuous feed for an aerated cathode chamber, was constructed in this experiment to investigate the performance of brewery wastewater treatment in conjugation with electricity generation. Carbon fiber was used as anode and plain carbon felt with biofilm as cathode. When hydraulic retention time (HRT) was 14.7 h, a relatively high chemical oxygen demand (COD) removal efficiency of 91.7%–95.7% was achieved under long-term stable operation. The MFC displayed an open circuit voltage of 0.434 V and a maximum power density of 830 mW/m3 at an external resistance of 300 ?. To estimate the electrochemical performance of the MFC, electrochemical measurements were carried out and showed that polarization resistance of anode was the major limiting factor in the MFC. Since a high COD removal efficiency was achieved, we conclude that the sequential anode-cathode MFC constructed with bio-cathode in this experiment could provide a new approach for brewery wastewater treatment.     

ATP content and biomass activity in sequential anaerobic/aerobic reactors

Specific ATP content of volatile solids was measured to characterize the sludge activity in a sequential anaerobic/aerobic wastewater treatment system, with an upflow anaerobic sludge blanket (UASB) reactor and a three-phase aerobic fluidized bed (AFB) reactor. The wastewater COD level was 2000(3000 mg/L in simulation of real textile wastewater. The ATP content and the specific ATP contents of volatile solids at different heights of the UASB reactor and those of the suspended and immobilized biomass in the AFB reactor were measured. In the UASB reactor, the maximum value of specific ATP (0.85 mg ATP/g VS) was obtained at a hydraulic retention time (HRT) 7.14 h in the blanket solution. In the AFB reactor, the specific ATP content of suspended biomass was higher than that of immobilized biomass and increased with hydraulic retention time reaching a maximum value of 1.6 mg ATP/g VS at hydraulic retention time 4.35 h. The ATP content of anaerobes in the UASB effluent declined rapidly under aerobic conditions following a 2nd-order kinetic model.     

ATP content and biomass activity in sequential anaerobic/aerobic reactors

INTRODUCTION limiting conditions, obligatory aerobic and an- aerobic bacteria will survive in a mixed culture Sequential anaerobic/aerobic wastewater treat- (Gerritse et al., 1992). Little is know about thement has received increasing attention for effective change in the activity of anaerobic bacteria whennutrient removal, enhanced de…     

Toxicity of cadmium to soil microbial biomass and its activity：Effect of incubation time on Cd ecological dose in a paddy soil

INTRODUCTION Cadmium (Cd) is ubiquitous in the human en-vironment and has been recognized as one of the mostdeleterious heavy metal pollutants (Robards andWorsfold, 1991; Christine, 1997). It may easily movefrom soil to food plants through root absorption andaccumulate in their tissues (Oliver, 1997). In this way,Cd may enter the food chain and affect human health(Adriano, 1986). Among many heavy metals pollut-ing soil, Cd is of concern because of its potentiallyharmful effects on…     

Effect of land use on microbial biomass-C, -N and -P in red soils

INTRODUCTIONTheimportanceofmicroorganismstosoilfer tilityandsoilqualityhasbeencommonlyaccept ed (Smithetal.,1 990 ;Brookes,1 995;Da lal,1 998;Wicketal.,1 998) .Soilmicrobialbiomassasanimportantmicrobialpropertyhasbeenextensivelystudiedsinceitisthelivingco…     

Physical activity during physical education lessons: a qualitative investigation of Australian PE teacher perceptions

School physical education (PE) experiences play a critical role in adolescents’ physical activity (PA) levels. Teachers are crucial to students’ initial experiences in PA; however, limited research has explored teachers’ perspectives about PA during PE using in-depth qualitative research techniques. We conducted interviews with 25 current Australian male and female PE teachers to investigate their perceptions about PA in secondary school PE (grades 7–12). Our findings indicated PA was a major focus for teachers during PE lessons; however, many physical and psychosocial factors underpinned practical classes. During PE lessons, PE teachers favoured game-based activities to promote PA while citing the traditional skill-drill approach as a strategy that limited PA. These findings highlight an ongoing shift in PE teaching towards a games-based approach and have several important implications for future teaching practice and research.     

Diversity change of microbial communities responding to zinc and arsenic pollution in a river of northeastern China

Pollution discharge disturbs the natural functions of water systems. The environmental microbial community composition and diversity are sensitive key indicators to the impact of water pollutant on the microbial ecology system over time. It is meaningful to develop a way to identify the microbial diversity related to heavy metal effects in evaluating river pollution. Water and sediment samples were collected from eight sections along the Tiaozi River where wastewater and sewage were discharged from Siping City in northeastern China. The main pollutants contents and microbial communities were analyzed. As the primary metal pollutants, zinc (Zn) and arsenic (As) were recorded at the maximum concentrations of 420 and 5.72 μg/L in the water, and 1704 and 1.92 mg/kg in the sediment, respectively. These pollutants posed a threat to the microbial community diversity as only a few species of bacteria and eukaryotes with strong resistance were detected through denaturing gradient gel electrophoresis (DGGE). Acinetobacter johnsonii, Clostridium cellulovorans, and Trichococcus pasteurii were the dominant bacteria in the severely polluted areas. The massive reproduction of Limnodrilus hoffmeisteri almost depleted the dissolved oxygen (DO) and resulted in the decline of the aerobic bacteria. It was noted that the pollution reduced the microbial diversity but the L. hoffmeisteri mass increased as the dominant community, which led to the overconsuming of DO and anaerobic stinking water bodies. Water quality, concentrations of heavy metals, and the spatial distribution of microbial populations have obvious consistencies, which mean that the heavy metals in the river pose a serious stress on the microorganisms.     

发展中国家的利率、储蓄与投资:一种理论综合与政策框架--对麦金农-肖两假说的再探讨

运用三阶段生命周期消费理论构造的储蓄－投资行为的微观模型，可以分析存款在财富积累过程不同阶段中的不同作用，表明利率政策通过既影响内源融资投资的收益又影响外源融资的可能性从而影响资本形成。基于微观模型的储蓄－投产行为的宏观模型，可以阐释利率对总储蓄、总投资及货币需求的作用机制。基于跨时期理论的分析框架，说明了麦金农－肖两假说间的相容性，强调了利率作用于投资储蓄及手续资产等决定时的时滞性。上述理论对我国如何确定总投资、总储蓄及货币需求，提供有益的借鉴。     

Physical activity and sedentary behaviour during outdoor learning and traditional indoor school days among Finnish primary school students

In this study, we aimed at comparing Finnish primary school students’ physical activity and sedentary time during outdoor-learning and traditional school days. Outdoor learning is defined as purposeful and planned learning experiences in the outdoors . The study population consisted 20 students in grades 1–6 at one primary school. Physical activity was measured objectively by hip-worn accelerometers. The amounts of physical activity and sedentary time were compared for the same students between five school days with outdoor learning and four traditional school days. The study’s main findings show that, moving from traditional classroom teaching to an outdoor-learning environment decreases students’ sedentary time and increases light- and moderate-intensity physical activity during the school day. No differences were observed in leisure-time physical activity on school days with or without outdoor learning. Thus, outdoor learning is an effective complement to traditional classroom teaching in promoting physically active children.     

Using log variables in a learning management system to evaluate learning activity using the lens of activity theory

As the advance of learning technologies and analytics tools continues, learning management systems (LMSs) have been required to fulfil the growing expectations for smart learning. However, the reality regarding the level of technology integration in higher education differs considerably from such expectations or the speed of advances in educational technologies. This research aimed to evaluate the current activation levels and usage patterns of a LMS. A large data-set was analysed, which included the online activity information from 7940 courses. Through data pre-processing, general indicators reflecting login frequencies of the virtual campus and activity-based indicators presenting the activation patterns of diverse functions provided by Moodle were derived. Activity theory was applied to interpret the results of analysis, since it has been recognised as a powerful framework to understand phenomena encompassing interactive systems. Further, time-series investigation over three consecutive semesters allowed observation of historical changes. The results revealed considerably low use of the virtual campus with only slight changes, as well as significantly different activity patterns across course attributes and colleges. Contradictions among components in the activity system are discussed, along with the implications for improving teaching and learning with LMS in higher education.     

Play to learn: a case-study of parent/carer and child engagement with a physical activity website resource

In 2007, Sport Wales produced guidance for practitioners delivering the new Foundation Phase curriculum for children aged three to seven years. A focus was on physical development and in 2009 a resource entitled Play to Learn was developed supported by a website launched in 2011. The present study addresses (non-)engagement with the website. Based on a qualitative study (interviews and focus groups) with a small cohort of parents from a primary school in South Wales, the findings revealed some of the reasons for only low levels of engagement from parents/carers. ‘Hard copy’ resource materials were considered more useful than electronic media.     

Preschooler's physical activity levels and associations with lesson context,teacher's behavior,and environment during preschool physical education

Preschools offer two main opportunities, recess and physical education (PE), for preschool children to participate in physical activity (PA) and are considered a suitable institution for PA promotion given the large number of children enrolled. Although PE can have a meaningful effect on preschoolers’ PA levels, preschool PE characteristics associated with increased PA have, to the best of our knowledge, not been identified. Therefore, the purpose of the present study was to examine preschooler's PA levels and the associations with lesson context, teacher behavior, and environment during preschool physical education. A random sample of 573 preschoolers (288 boys; M_age = 5.4 years, SD = 0.4) from 35 preschools was examined during one PE class. Findings indicated that preschoolers accumulated 12 min (33%) of moderate-to-vigorous PA (MVPA), 5 min (13%) of light PA, and 20 min (54%) of sedentary behavior during PE. Forty-seven percent of the variance in pupils’ MVPA may be attributed to differences between PE classes. Less knowledge content, less promotion, less management, less preschoolers per 100 m², using obstruction material, and not using throwing equipment were significantly associated with higher MVPA levels. These predictors explained 56% of the variance in MVPA at the PE class-level. To conclude, PE in its current format contributes only a small amount to the PA requirements of preschoolers. Preschoolers’ MVPA levels were related to modifiable PE characteristics indicating that preschool PE can be restructured to increase MVPA.     

The use of video-based instruction to promote independent performance of physical activity skills in students with developmental disabilities in a school and community setting

School psychologists are well-positioned to assist practitioners in engaging students in physical activity (PA) which can increase student access to improved well-being and associated health benefits. This may be of particular importance for adolescents with moderate to severe developmental disabilities (DD; autism and intellectual disability) who display various deficits in performing PA skills. Previous research suggests video-based instruction (VBI) effectively facilitated independence associated with PA skills in people with DD, however, additional research is warranted. The purpose of this study was to evaluate the degree a VBI impacted acquisition of skills in individuals with DD at school, and, subsequently, in a community setting. Multiple probe design was used to assess the effect of the intervention in four participants. The results indicate the intervention was effective in teaching three participants to perform the circuit in the school setting and transfer the skills to the community setting; however, maintenance was variable. Implications related to practice for school psychologists, teachers, and other practitioners, as well as, limitations and future research directions are discussed.     

小飞蓬化学成分及生物活性研究进展

综述了国内外对小飞蓬地上部分、地下部分、花和果实等部位中其化学成分、生物活性、影响因素等方面的研究进展.小飞蓬的主要化学成分有烃类、萜类、酮类、生物碱、鞘脂类、醇类和黄酮类等,其主要生物活性有化感作用、抑菌作用、抗病毒、抗癌、抗氧化等,为今后对小飞蓬的研究和利用提供参考.     

Active Families in the Great Outdoors: a program to promote family outdoor physical activity

This study evaluated a 4-week program to increase the time families spent engaging in outdoor activity. Parents were provided strategies to increase family outdoor activity and locations to be active. Sixteen families completed the program. Duration and number of family outdoor activity bouts per week, type of activities, locations, and family member attendance were measured using logs. Pre/post surveys were conducted to determine the usefulness of providing educational resources and maps. Compared to baseline (216.1±127.3 min/week), family outdoor activity for weeks 1 (316.1±180.2 min/week), 2 (351.1±209.1 min/week), and 4 (317.5±186.8 min/week) were significantly greater at follow-up. At follow-up, parents reported increased regular exercise and encouragement for their child to be active. Children reported adults engaged in physical activity with them and increased transportation to places to be active. This novel program increased family outdoor activity levels and contributes to limited research on strategies to increase outdoor activity in youth.     

Conceptions of ‘research’ and their gendered impact on research activity: a UK case study

ABSTRACT

The last twenty years have seen an increased emphasis around the world on the quality and quantity of research in response to national research assessments, international league tables, and changes in government funding. The prevailing attitude in higher education embeds research as the ‘gold standard’ in the context of academic activity. However, a key feature of this trend is significant gender differences in research activity. We argue that research productivity is related to identification as a researcher, and that identifying as ‘research-active’ or not would appear to depend upon how an individual academic subjectively defines ‘research’. This article brings together two hitherto separate bodies of work (1) the impact of gender on academic research careers, and (2) academic conceptions of research. Through a combination of interviews, focus groups and questionnaires, we investigate the extent to which interpretations of ‘research’ and ‘research activity’ differ by gender within an institution in the UK and the potential impact of these interpretations. Although the research found that there are many similarities in the interpretations of ‘research activity’ between genders, we found one important difference between male and female participants’ conceptions of research and its relationship to teaching. Significantly, our findings suggest that there is a need to expand our existing conceptualisations of ‘research’ to include ‘research as scholarship’ in order to address the obstacles that current understandings of ‘research’ have placed on some academics. Self-definition as a researcher underlies research activity. A narrow conception of ‘research’ may prevent individuals from identifying as ‘research-active’ and therefore engaging with research.     

Narratives and activity theory as reflective tools in action research

Narratives and activity theory are useful as socially constructed data collection tools that allow a researcher access to the social, cultural and historical meanings that research participants place on events in their lives. This case study shows how these tools were used to promote reflection within a cultural–historical activity theoretically shaped research project on multi-professional collaborative practice. The tools are shown to individually and jointly aid insight, understanding and action. The participants generated data through narratives and analysed the data with an activity theoretical framework. These were then interpreted as cultural historical artefacts by the researcher. The socially constructed paradigm within which they are situated, their participative use, and their creation of insight, understanding and action make them ideal as action research tools.