Experimental effects of ash deposition on macroinvertebrate assemblages in peatland streams

2018 ◽  
Vol 69 (11) ◽  
pp. 1681
Author(s):  
K. Johnston ◽  
B. J. Robson
Keyword(s):  
Environmental Conditions ◽  
Significant Relationship ◽  
Headwater Streams ◽  
Dry Mass ◽  
Ash Deposition ◽  
Assemblage Composition ◽  
Macroinvertebrate Assemblages ◽  
Natural Stream ◽  
And Control ◽  
Stream Depth

Rotational burn management has been practiced for >150 years in UK peatlands; however, little information exists on its effects on streams. An experiment investigated effects of ash input on four UK headwater streams by depositing ash onto trays filled with natural stream substrata. Before the experiment, streambed samples (SS) were taken to describe ambient macroinvertebrate assemblages. Macroinvertebrate response after 21 days was compared among SS, low (50g), high (100g) and top-up (50g + 50g dosed twice) ash-addition treatments and control trays (0g ash addition). Additions increased tray ash-free dry mass (AFDM), and by the end of the experiment, some trays retained more ash than did others (F12,72=5.15, P<0.001). Macroinvertebrate assemblages differed among streams (r=0.84, P<0.001) and treatments (r=0.23, P<0.001). SS contained fewer shredders than did other treatments (range: r=0.35–0.52, P=0.005). A significant relationship was found between assemblages and environmental conditions (Spearmans rho: 0.203, P=0.001). Stream depth and AFDM showed strongest correlations with assemblages. Ash deposition affects macroinvertebrate assemblages when deposited onto streambeds. However, the high among-stream variation in assemblage composition typical of UK headwaters is a stronger source of variation, suggesting that the effect of deposition is reasonably small in these streams.

Dry chip feedrate control using online chip moisture

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 295-305
Author(s):  
Wesley Gilbert ◽  
Ivan Trush ◽  
Bruce Allison ◽  
Randy Reimer ◽  
Howard Mason
Keyword(s):  
Production Rate ◽  
Control Strategy ◽  
Rate Control ◽  
Near Infrared ◽  
Dry Mass ◽  
The Other ◽  
Process Variability ◽  
Moisture Sensor ◽  
Feedback Control Strategy ◽  
And Control

Normal practice in continuous digester operation is to set the production rate through the chip meter speed. This speed is seldom, if ever, adjusted except to change production, and most of the other digester inputs are ratioed to it. The inherent assumption is that constant chip meter speed equates to constant dry mass flow of chips. This is seldom, if ever, true. As a result, the actual production rate, effective alkali (EA)-to-wood and liquor-to-wood ratios may vary substantially from assumed values. This increases process variability and decreases profits. In this report, a new continuous digester production rate control strategy is developed that addresses this shortcoming. A new noncontacting near infrared–based chip moisture sensor is combined with the existing weightometer signal to estimate the actual dry chip mass feedrate entering the digester. The estimated feedrate is then used to implement a novel feedback control strategy that adjusts the chip meter speed to maintain the dry chip feedrate at the target value. The report details the results of applying the new measurements and control strategy to a dual vessel continuous digester.

scholarly journals Cardiac Parasympathetic Withdrawal and Sympathetic Activity: Effect of Heat Exposure on Heart Rate Variability

2021 ◽  
Vol 18 (11) ◽  
pp. 5934
Author(s):  
Oriol Abellán-Aynés ◽  
Pedro Manonelles ◽  
Fernando Alacid
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Environmental Conditions ◽  
Sympathetic Activity ◽  
Heat Exposure ◽  
Repeated Measurements ◽  
Control Group ◽  
Poincaré Plot ◽  
Activity Effect ◽  
And Control

(1) Background: Research on heart rate variability has increased in recent years and the temperature has not been controlled in some studies assessing repeated measurements. This study aimed to analyze how heart rate variability may change based on environmental temperature during measurement depending on parasympathetic and sympathetic activity variations. (2) Methods: A total of 22 volunteers participated in this study divided into an experimental (n = 12) and control group (n = 10). Each participant was assessed randomly under two different environmental conditions for the experimental group (19 °C and 35 °C) and two identical environmental conditions for the control group (19 °C). During the procedure, heart rate variability measurements were carried out for 10 min. (3) Results: Significantly changes were observed for time and frequency domains as well as Poincaré plot variables after heat exposure (p < 0.05). These findings were not observed in the control group, whose conditions between measurements did not change. (4) Conclusions: The reduction of heart rate variability due to exposure to hot conditions appears to be produced mostly by a parasympathetic withdrawal rather than a sympathetic activation. Therefore, if consecutive measurements have to be carried out, these should always be done under the same temperature conditions.

Boards of Governors' Roles and Management of Government Aided Secondary Schools in Kyenjojo District, Uganda

2018 ◽  
Vol 1 (2) ◽  
pp. 138-150
Author(s):  
Hellen Kabasinguzi Wataba ◽  
Nafiu Lukman Abiodun
Keyword(s):  
Secondary Schools ◽  
Significant Relationship ◽  
Quantitative Data ◽  
Qualitative Data ◽  
Head Teachers ◽  
Correlational Research ◽  
Interview Guide ◽  
Major Predictor ◽  
And Control ◽  
The Relationship

This study sought to establish the relationship between boards of governors' (BOGs) roles and management of government aided secondary schools in Kyenjojo District. The objectives were to establish the relationship between BOGs' planning role and management of government aided secondary schools, to establish the relationship between BOGs' supervisory role and management of government aided secondary schools, to establish the relationship between BOGs' control role and management of government aided secondary schools; and to determine the major predictor of management of government aided secondary schools out of the three aspects of BOGs' roles. A correlational research design was used. A total of 90 respondents drawn from 108 BOGs and nine head teachers were selected as sample for the study using stratified random sampling and census inquiry respectively. The instruments used were questionnaire and interview guide. Quantitative data was analysed using Pearson product-moment correlation and regression, while thematic analysis was used on qualitative data. The study found a statistically moderate positive and significant relationship between BOGs' planning role and management of government aided secondary schools (r=.626, p=.000); a statistically moderate positive and significant relationship between BOGs' supervisory role and management of government aided secondary schools(r=.591, p=.000); and a statistically weak positive and significant relationship between BOGs' control role and management of government aided secondary schools(r=.280, p=.015). All the three aspects of BOGs roles account for 38.4% of the influence on management of government aided secondary schools in Kyenjojo district (adjusted r2=0.384, p=.000). The researchers recommend that BOGs should be well trained in management of schools in order to be effective in their work. Head teachers should not be dictators but create a conducive climate for planning, supervision and control by the BOGs.

scholarly journals Mingle Model for Increasing Productive Language Skills and Relationship with Student’s Personality Based on Jung Theory

2021 ◽  
Vol 5 (1) ◽  
pp. 35-51
Author(s):  
Suci Ramadhanti Febriani ◽  
Wildana Wargadinata ◽  
Syuhadak Syuhadak
Keyword(s):  
Data Collection ◽  
Research Methods ◽  
Significant Relationship ◽  
Language Skills ◽  
Correlation Method ◽  
Quantitative Approach ◽  
Control Group ◽  
Carl Gustav Jung ◽  
And Control ◽  
The Relationship

This study aims to find the effect of the implemetation of the Mingle Model on productive language skills and the relationship to the personality based on Carl Gustav Jung Theory in Arabic learning at MTsN Batu City, East Java. This research used a quantitative approach by combining the experimental and correlation methods, it was applying the Mingle Model to improve students' productive skills (speaking and writing) which have been divided into two groups; the Experiment and Control group and connected using the correlation method to extroverted and introverted students based on the theory of Carl Gustav Jung. Data collection through questionnaires, tests, and documentation. The results showed that there was a significant relationship to students' productive skills after applying the Mingle Model and there were no significant differences between extroverted and introverted students. This research recommend that the Mingle Model can be applied to improve students' productive skills. This study recommends further research to utilise more varied research methods with more diverse variables.

scholarly journals Integrated management of tough lovegrass (Eragrostis plana Nees): associating chemical control tools and plant physiology

2021 ◽  
Vol 51 (2) ◽  
Author(s):  
Eduardo Avelino Faleiro ◽  
Diego Martins Chiapinotto ◽  
Fabiane Pinto Lamego ◽  
Carlos Eduardo Schaedler ◽  
Eduardo Bohrer de Azevedo
Keyword(s):  
Solar Radiation ◽  
Integrated Management ◽  
Dry Mass ◽  
Radiation Factor ◽  
Factor B ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Factor C ◽  
Resource Conditions ◽  
And Control

ABSTRACT: The objective of the study was to evaluate the efficiency of herbicides use in the control of tough lovegrass according to the availability of solar radiation and the presence or absence of flooded. Two experiments were conducted in a completely randomized design, in a 2x2x4 and 2x2x5 factorial scheme, where factor A was equivalent to the environment (natural or reduced radiation); factor B to water condition (with a 2 cm flooded or without); and, factor C the herbicides: cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), cyhalofop butyl + glyphosate (315 g ha-1 + 1080 g ha-1) and control (without application) in the first experiment. In the second experiment, the herbicides used were cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), sethoxydim (184g ha-1), imazethapyr (106 g ha-1) and control (without application). Glyphosate efficiently controls plants of tough lovegrass with four tillers (>90%), being superior to cyhalofop, imazethapyr and sethoxydim; independently, of resource conditions. Reduction in the availability of solar radiation generates less shoot dry mass production from the weed, and improves the control only by imazethapyr and cyhalofop. In general, a flooded condition does not affect tough lovegrass control by herbicides.

Bioeroding sponge assemblages: the importance of substrate availability and sediment

2018 ◽  
Vol 99 (2) ◽  
pp. 343-358 ◽  
Author(s):  
Joseph Marlow ◽  
Christine H.L. Schönberg ◽  
Simon K. Davy ◽  
Abdul Haris ◽  
Jamaluddin Jompa ◽  
...  
Keyword(s):  
Coral Reef ◽  
Environmental Factors ◽  
Spatial Variation ◽  
Environmental Conditions ◽  
Sponge Species ◽  
Coral Mortality ◽  
Substrate Availability ◽  
Abiotic Conditions ◽  
Assemblage Composition ◽  
Reef Health

Despite global deterioration of coral reef health, not all reef-associated organisms are in decline. Bioeroding sponges are thought to be largely resistant to the factors that stress and kill corals, and are increasing in abundance on many reefs. However, there is a paucity of information on how environmental factors influence spatial variation in the distribution of these sponges, and how they might be affected by different stressors. We aimed to identify the factors that explained differences in bioeroding sponge abundance and assemblage composition, and to determine whether bioeroding sponges benefit from the same environmental conditions that can contribute towards coral mortality. Abundance surveys were conducted in the Wakatobi region of Indonesia on reefs characterized by different biotic and abiotic conditions. Bioeroding sponges occupied an average of 8.9% of available dead substrate and variation in abundance and assemblage composition was primarily attributed to differences in the availability of dead substrate. Our results imply that if dead substrate availability increases as a consequence of coral mortality, bioeroding sponge abundance is also likely to increase. However, bioeroding sponge abundance was lowest on a sedimented reef, despite abundant dead substrate. This suggests that not all forms of coral mortality will benefit all bioeroding sponge species, and sediment-degraded reefs are likely to be dominated by a few resilient bioeroding sponge species. Overall, we demonstrate the importance of understanding the drivers of bioeroding sponge abundance and assemblage composition in order to predict possible impacts of different stressors on reefs communities.

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