The ecology of Sminthurus viridis (L.) (Collembola). I. Processes influencing numbers in pastures in Western Australia

1967 ◽  
Vol 15 (6) ◽  
pp. 1173 ◽  
Author(s):  
MMH Wallace
Keyword(s):  
Western Australia ◽  
Dominant Role ◽  
Clay Content ◽  
Early Death ◽  
Factors Affecting ◽  
Dead Bodies ◽  
Fat Bodies ◽  
Set Up ◽  
Content Support ◽  
Type 3

The changes in numbers of Sminthurus viridis (Collembola: Sminthuridae) in pastures in Western Australia were studied for 9 years on one site and for shorter periods on other sites. Five factors affecting numbers are described: (1) weather, (2) soil type (3) botanical composition of the pasture, (4) predation by Bdellodes lapidaria (Acarina: Bdellidae), and (5) eating of dead bodies by newly hatched nymphs. Weather is generally favourable for the active stages during autumn, winter, and spring. In the summer, the species is maintained by aestivating eggs. Dry periods during the winter months sometimes cause high mortalities. Soils containing a high silt-plus-clay content support higher numbers due mainly to increased oviposition. Flea densities increase more rapidly where there is a high proportion of broad-leaved plants, such as clover and capeweed in the pasture. Grassy areas are not favoured. Predation by B. lapidaria effectively reduces numbers. The presence of more than 20 B. lapidaria per square metre early in the winter prevents any outbreak of fleas later in the season. Bdellodes lapidaria numbers increase in response to an increase in flea numbers. An irregular predator-prey cycle is set up in this way. Density-induced mortality, resulting from the newly hatched nymphs eating the bodies of recently dead fleas, plays a dominant role at high densities. This process operates continuously though at decreased intensity at lower densities. When newly hatched nymphs feed upon dead nymphs and adults they ingest materials which cause early death. Sometimes this may lead to a dramatic collapse of the population. Fleas from high-density populations usually contain large quantities of uric acid in their "fat-bodies". It is suggested that death of the mature fleas at high densities is hastened through the storage of excessive amounts of waste material. Death of the young nymphs feeding upon the dead bodies may be brought about by the ingestion of these waste materials, although this has yet to be proven.

scholarly journals Circulation and Molecular Epidemiology of Enteroviruses in Paralyzed, Immunodeficient and Healthy Individuals in Tunisia, a Country with a Polio-Free Status for Decades

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 380
Author(s):  
Anissa Chouikha ◽  
Dorra Rezig ◽  
Nadia Driss ◽  
Ichrak Abdelkhalek ◽  
Ahlem Ben Yahia ◽  
...  
Keyword(s):  
Detection Rate ◽  
Warning System ◽  
World Health ◽  
Clinical Samples ◽  
Nucleotide Sequencing ◽  
Comprehensive Picture ◽  
Set Up ◽  
Health Organization ◽  
Type 3

This report is an overview of enterovirus (EV) detection in Tunisian polio-suspected paralytic cases (acute flaccid paralysis (AFP) cases), healthy contacts and patients with primary immunodeficiencies (PID) during an 11-year period. A total of 2735 clinical samples were analyzed for EV isolation and type identification, according to the recommended protocols of the World Health Organization. Three poliovirus (PV) serotypes and 28 different nonpolio enteroviruses (NPEVs) were detected. The NPEV detection rate was 4.3%, 2.8% and 12.4% in AFP cases, healthy contacts and PID patients, respectively. The predominant species was EV-B, and the circulation of viruses from species EV-A was noted since 2011. All PVs detected were of Sabin origin. The PV detection rate was higher in PID patients compared to AFP cases and contacts (6.8%, 1.5% and 1.3% respectively). PV2 was not detected since 2015. Using nucleotide sequencing of the entire VP1 region, 61 strains were characterized as Sabin-like. Among them, six strains of types 1 and 3 PV were identified as pre-vaccine-derived polioviruses (VDPVs). Five type 2 PV, four strains belonging to type 1 PV and two strains belonging to type 3 PV, were classified as iVDPVs. The data presented provide a comprehensive picture of EVs circulating in Tunisia over an 11-year period, reveal changes in their epidemiology as compared to previous studies and highlight the need to set up a warning system to avoid unnoticed PVs.

scholarly journals Internal Factors Affecting the Surface Rumpling of a β-NiAlHf Coating

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 436
Author(s):  
Liang Liu ◽  
Jian He ◽  
Yaoge Dong ◽  
Hongbo Guo
Keyword(s):  
Physical Vapor Deposition ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Dominant Role ◽  
Cyclic Loads ◽  
Internal Factor ◽  
Internal Factors ◽  
Factors Affecting ◽  
Mismatch Stress ◽  
Thermal Mismatch Stress

β-NiAl coatings on a superalloy substrate will inevitably result in severe rumpling at elevated temperatures; however, the associated rumpling mechanisms are not completely understood. The scale rumpling behavior of a β-NiAlHf coating deposited by electron beam physical vapor deposition (EB-PVD) on single crystal superalloy IC21 was investigated in this work. Some internal factors, including the mismatch in the coefficient of thermal expansion and the stress induced by the growth of oxide scale and the phase transformation, were taken into consideration. The thermal mismatch stress between the coating and substrate was the main internal factor responsible for rumpling behavior during thermal cyclic loads, while the phase degradation from β-NiAl to γ’-Ni3Al in the coating played a dominant role during static thermal loads.

Ticket Income Distribution of Urban Rail Transit in Network Operating Condition

2011 ◽  
Vol 243-249 ◽  
pp. 4375-4380
Author(s):  
Yuan Chun Huang ◽  
Jian Li ◽  
Haize Pan
Keyword(s):  
Income Distribution ◽  
Urban Rail Transit ◽  
Ratio Method ◽  
Rail Transit ◽  
Matching Algorithm ◽  
Factors Affecting ◽  
Urban Rail ◽  
Set Up ◽  
Urban Rail Transit Network ◽  
Factor Matching

Through analyzing the factors affecting passengers’ path-choice, the corresponding principles and rules of the ticket income distribution are put forward and the new model of the Urban Rail Transit Network in Beijing is set up in the paper. Through the deformation of the urban rail transit and the simplification of the lines, the topology of the urban rail transit lines is abstracted into an undirected connection graph. Breadth-priority optimization algorithm is applied to search the effective paths between the OD and the flow-matching ratio is acquired by calculating based on multi-factor matching algorithm, in which many relevant numerical examples are analyzed to verify the feasibility of the dual-ratio method and to summarize the characteristics of the project.

Investigation of Drilling Temperature in Relation to Machining Conditions and Cutting Time

2020 ◽  
Author(s):  
Charbel Y. Seif ◽  
Ilige S. Hage ◽  
Ahmad M. R. Baydoun ◽  
Ramsey F. Hamade
Keyword(s):  
Temperature Rise ◽  
Cutting Speed ◽  
Drilling Depth ◽  
Machining Center ◽  
Drilling Temperature ◽  
Wide Range ◽  
Set Up ◽  
Type 3 ◽  
Flank Surface ◽  
Thrust Forces

Abstract Controlling drilling temperature and thrust forces play a significant role in reducing tool wear and improving machining efficiency. In this work, drilling experiments are set up to measure flank surface temperature via thermocouple sensor wires passed through the coolant holes of 10mm twist drill and brazed to the drill flank surface. The testing setup is an inverted drilling jig where the workpiece (Aluminum 6061-T6 rod) is chucked into the spindle of a vertical machining center. Thrust forces are co-measured using Kistler type 3-component plate dynamometer attached to the table. A design of experiment (DOE) using JMP-SAS/STAT® was adopted for selecting combinations of cutting speed and feed values that cover a wide range. Drilling temperature rise and thrust forces are found to correlate with cutting conditions of feed (f), maximum cutting speed (V), and drilling depth (Dp). Nonlinear regression analysis produced correlating equations of flank temperature rise and thrust forces to conditions and follow a mechanistic power law of the form a1fa2Va3Dpa4 where a1, a2, a3 and a4 are identified via regression fitting.

scholarly journals A study of the factors affecting construction time in Western Australia

2012 ◽  
Vol 7 (40) ◽  
pp. 3390-3398 ◽  
Author(s):  
Wong Kenny ◽  
Vimonsatit Vanissorn
Keyword(s):  
Western Australia ◽  
Construction Time ◽  
Factors Affecting

The forms of potassium and potassium adsorption in some virgin soils from south-western Australia

Soil Research ◽  
1999 ◽  
Vol 37 (4) ◽  
pp. 695 ◽  
Author(s):  
Y. Pal ◽  
R. J. Gilkes ◽  
M. T. F. Wong
Keyword(s):  
Western Australia ◽  
Agricultural Soils ◽  
Clay Mineralogy ◽  
Sorption Isotherms ◽  
Clay Content ◽  
Water Soluble ◽  
X Ray Diffraction ◽  
Exchangeable K ◽  
The North ◽  
Southern District

This investigation was undertaken to determine the potassium (K) status and adsorption behaviour of 227 samples from horizons of 41 representative virgin soil profiles, extending from Geraldton in the north to the Great Southern district of Western Australia. X-ray diffraction analysis of random powder of whole soil indicated that quartz is the dominant mineral and some soils contain significant amounts of feldspars. Clay mineralogy is dominated by kaolinite but minor quantities of illite are present in some soils. Most south-west Australian agricultural soils contain little available K: NaHCO3-extractable K (NaHCO3-K, median value 0·09 cmol K/kg, equivalent to 35 mg K/kg soil), HNO3-extractable K (HNO3-K, median value 0·30 cmol K/kg, equivalent to 117 mg K/kg soil), and total K (XRF determined K, median value, 17 cmol K/kg, equivalent to 6630 mg K/kg soil). The proportion of water-soluble K (H2O-K) ranges from 0 to 3·5% of total K, 0 to 76% of HNO3-K, and 0 to nearly 100% of exchangeable K. Exchangeable K ranges from 0 to 100% (median value 37%) of HNO3-K. These are relatively high proportions of H2O-K and exchangeable K compared with soils from many other parts of the world. The amounts of all forms of K variously increase or decrease downwards in the soil profile depending on both clay content and mineralogy. The commonly assumed increase in K with clay content alone is invalid. The soils mostly have low-to-moderate values of K sorption capacity, ranging from 5% to 67% (median value 14%) of added K (initially 4·1 mM K/L, equivalent to 4·1 cmol K/kg). otassium sorption isotherms conform well to the Freundlich equation. The inability of the Langmuir equation to describe the data may indicate that there are several types of K sorption sites in these soils. The Gapon coefficient KG varied widely from 0·04 to 29·8 (L/mol) ½ [median value 5·4 (L/mol) ½ ].

Measuring Relative Effectiveness of Service Quality Factors Affecting Quality of Higher Education in India

2021 ◽  
Vol 11 (2) ◽  
pp. 30-46
Author(s):  
Anshuman Kaler
Keyword(s):  
Higher Education ◽  
Service Quality ◽  
Dominant Role ◽  
Relative Effectiveness ◽  
Program Quality ◽  
Quality Factors ◽  
Factors Affecting ◽  
Input Quality ◽  
Quality Of Higher Education

The existing competitive environment in the education sector in India has forced higher education institutes to adopt ‘students as a customer' approach in educational delivery. The extant literature supports seven dimensions of service quality namely input quality, curriculum, academic facilities, industry interaction, interaction quality, support facilities, and nonacademic processes. The objective of the study was to measure the relative effectiveness of service quality factors as perceived by the Indian students. Focus group interviews were conducted with a group of technical and management students. Stratified judgmental sampling was used for the data collection. In the current study, it was observed that the factor of program quality plays a more dominant role than the factor of quality of life in determining the service quality in institutes of higher education. It is further observed that in the sub-dimension of program quality, the factor of curriculum and academic facilities are relatively more dominant than the factor of input quality.

The Road Less Travelled

2020 ◽  
pp. 307-327
Author(s):  
Seema S. P.
Keyword(s):  
Women Managers ◽  
Well Being ◽  
Factors Affecting ◽  
The Road ◽  
Family Balance ◽  
Education In India ◽  
Managerial Positions ◽  
Work Family ◽  
Set Up ◽  
Work And Family Roles

One of the most crucial factors affecting development in the 21st century is the increased participation of women in the economy of a country and increased entrance to managerial positions. Even though such tremendous changes have taken place, the patriarchal social set up insists on women's responsibilities towards family and children. The domestic roles of women are not shared by men despite the fact that women have shared the economic and social responsibilities of men. This causes conflict among work and family roles, which ultimately affects the physical and psychological well-being of women managers. This chapter deals with the problems and challenges faced by women managers in higher education in India and how family support and suitable coping strategies help them maintain work-family balance.

scholarly journals Quantile Regression Analysis of Depression and Clinical Symptom Degree in Chinese Patients with Spinocerebellar Ataxia Type 3

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Xiaoping Chen ◽  
Lihui Zheng ◽  
Jianqi Yao
Keyword(s):  
Clinical Symptoms ◽  
Depression Scale ◽  
Chinese Patients ◽  
Psychological State ◽  
Spinocerebellar Ataxia Type ◽  
Spinocerebellar Ataxia Type 3 ◽  
Factors Affecting ◽  
Quantile Regression Analysis ◽  
And Gender ◽  
Type 3

Spinal cerebellar ataxia type 3 is a common SCA subtype in the world. It is a neurodegenerative disease characterized by ataxia. Patients exhibit common neuropsychological symptoms such as depression and anxiety. Some patients have suicidal tendencies when they are severely depressed. So, it is very important to study the severity of depression and clinical symptoms (SARA), to find out the patient’s psychological state in time and to help patients actively respond to treatment. A total of 97 Chinese SCA3 patients were enrolled in the study. The Beck Depression Scale was used to investigate the prevalence of depression in the confirmed patients. The distribution of depression data in these patients was investigated. Then, the quantifier was used to model the depression status of Chinese SCA3 patients. An analysis was conducted to identify the key factors affecting depression under different quantiles. Studies have shown that SARA and gender are important factors affecting depression; the effect of initial SARA is small, then the degree of influence increases, and the degree of influence decreases in the later period, but it is always positively correlated with depression; the development of women’s SARA is gentler than that of men, and the degree of depression is lower than that of men.

scholarly journals Kinematic bidimensional analysis of the propulsion technique in wheelchair rugby athletes

2020 ◽  
Vol 30 (1) ◽  
pp. 129-133
Author(s):  
Sara Maria Franchin ◽  
Federico Giordani ◽  
Michele Tonellato ◽  
Michael Benazzato ◽  
Giuseppe Marcolin ◽  
...  
Keyword(s):  
Upper Limb ◽  
Cervical Spinal Cord ◽  
Contact Angles ◽  
Kinematic Parameters ◽  
Factors Affecting ◽  
Wheelchair Rugby ◽  
Circular Pattern ◽  
Cord Injury ◽  
Speed Range ◽  
Set Up

Wheelchair rugby is a sport ideated for individuals with cervical spinal cord injury (CSCI) which is extremely important for maintaining their neuromuscular abilities and improving their social and psychological wellbeing. However, due to the frequent changes in direction and speed it considerably stresses the players’ upper limbs. 13 athletes have undergone two sports-related tests on an inertial drum bench and several kinematic parameters have been registered. Most athletes use a semi-circular pattern which is considered protective for the upper limb. With increasing speed, range of motion (ROM) increases. Release angles increment and contact angles reduce, displacing the push angle forward to increase speed. Instead, the more anterior late push angle used to increase velocity is a factor which further loads the shoulder joint. However, other factors affecting propulsion technique, such as posture and wheelchair set up should be studied to further reduce loading on the upper limb.

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