THE INFLUENCE OF CONSTANT TEMPERATURES ON THE NON-DIAPAUSE DEVELOPMENT OF HYSSOPUS THYMUS (HYMENOPTERA: EULOPHIDAE)

1972 ◽  
Vol 104 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Paul D. Syme
Keyword(s):  
Developmental Stages ◽  
Climatic Conditions ◽  
Thermal Constant ◽  
Regression Equations ◽  
Degree Days ◽  
Different Temperatures ◽  
Potential Impact ◽  
Diapause Development ◽  
The Relationship ◽  
Fluctuating Temperatures

AbstractThe influence of constant temperatures on the non-diapause development of Hyssopus thymus was studied and the results of these studies are presented. A lower threshold for development of less than 12 °C and an upper threshold of about 32 °C were determined. Mean times for and rates of development at different temperatures are presented for all developmental stages. The egg is the stage most sensitive to temperature change. Regression equations describing the relationship between the rate of development and temperature for these stages are given and a thermal constant (K) of about 190 degree-days is calculated for total development. This constant is not applicable to naturally fluctuating temperatures. The results of these studies are discussed in relation to the potential impact of H. thymus on European pine shoot moth dynamics under different climatic conditions. It is concluded that H. thymus should be more effective in warmer seasons and at lower latitudes.

scholarly journals Impacts of Temperature and Rootstocks on Tomato Grafting Success Rates

HortScience ◽  
2020 ◽  
Vol 55 (2) ◽  
pp. 136-140
Author(s):  
Thibault Nordey ◽  
Elias Shem ◽  
Joel Huat
Keyword(s):  
Hydraulic Conductivity ◽  
Success Rate ◽  
Developmental Stages ◽  
Climatic Conditions ◽  
Vegetable Crops ◽  
Success Rates ◽  
Degree Days ◽  
Plant Vigor ◽  
Different Temperatures ◽  
Number Of Leaves

Numerous studies have highlighted the merits of grafting to improve the performance of vegetable crops. However, the technique is hindered by several obstacles, including the synchronization of seedlings used as scions and rootstocks, and the effects of rootstocks and climatic conditions on grafting success rates. This study sought to gain insights into how such technical obstacles affect tomato grafting. An initial experiment conducted in a greenhouse set out to assess the relevance of using degree-days to predict the growth rates of seedlings used for grafting (i.e., stem diameters above cotyledons). The success rate for grafting a tomato variety (Tanya) on 10 different rootstocks from different species—namely tomato, eggplant, african eggplant, and a wild species—was assessed at different temperatures (i.e., 15, 20, 25, 30, 35, and 40 °C). The effects of grafting on plant vigor (i.e., fresh biomass), number of leaves, and plant height, and on the hydraulic conductivity of xylem vessels in the plant stem were assessed 2 weeks after grafting. The results show the advantage of using degree-days to predict the ready-to-graft stage of seedlings, as it reduced the discrepancy among trials. The grafting success rate was more than 90% at 15 and 20 °C, but decreased significantly with higher temperatures, down to 20% at 40 °C. Larger variations in growth rate for seedlings used as scions and rootstocks, a lower grafting success rate, and less vigor were recorded for heterografted plants than for homografted plants. The lower hydraulic conductivity measured in the stems of grafted plants, especially heterografted plants, was consistent with the lower plant vigor observed. Further studies are needed to investigate how grafting affects the hydraulic conductivity of xylem vessels in later developmental stages of grafted plants.

scholarly journals Determination of thermal constant and development threshold of Bihar hairy caterpillar, Spilarctia obliqua Walker

2014 ◽  
Vol 6 (2) ◽  
pp. 644-648 ◽  
Author(s):  
K. Selvaraj ◽  
B. S. Gotyal ◽  
V. Ramesh Babu ◽  
S. Satpathy
Keyword(s):  
Development Rate ◽  
Developmental Period ◽  
Adult Survival ◽  
Thermal Constant ◽  
Regression Equations ◽  
Small Larva ◽  
Degree Days ◽  
Large Larva ◽  
Developmental Threshold ◽  
Spilarctia Obliqua

Effect of six constant temperatures viz., 18±1, 21±1, 24±1, 27±1, 30±1 and 33±10C was studied on the egg hatchability, larval pupal development and adult survival of Spilarctia obliqua. Development rate of egg, larva and pupa gradually increased with increase in temperature, while total developmental period decreased. Mean developmental period of the pest decreased from 93.73 days at 18±10C to 31.20 at 33±10C. The lowest and the highest temperatures at which no development took place were found to be 12±10C and 39±10C, respectively. Regression equations between development rate and temperature were found to be Y= 0.0189 X -0.1998 (R2=0.88) for egg, Y=0.00122 X -0.0248 (R2=0.84) for small larva (1-3rd instar), Y=0.0058 X -0.0675 (R2=0.76) for large larva (4-6th instar), Y=0.0074 X-0.1075 (R2=0.94) for pupa and Y=0.0142 X-0.4363 (R2=0.79) for adults. Developmental threshold were determined to be 10.57, 11.27, 11.55, 15.28 and 10.92oC for egg, small larva, large larva, pupa, and adult respectively with corresponding thermal constant being 52.91, 344.82, 243.90, 142.85 and 70.42 degree days (DD). Thermal constant to complete a generation was found to be 854.90 DD. This was the first studies on this aspects, these estimated thermal thresholds and degree days could be used to predict the S. obliqua activity in the field for their effective management through pest forecasting.

scholarly journals Biology and thermal requirements of Telenomus remus reared on fall armyworm Spodoptera frugiperda eggs

2008 ◽  
Vol 38 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Regiane Cristina Oliveira de Freitas Bueno ◽  
Tatiana Rodrigues Carneiro ◽  
Dirceu Pratissoli ◽  
Adeney de Freitas Bueno ◽  
Odair Aparecido Fernandes
Keyword(s):  
Sex Ratio ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Thermal Constant ◽  
Degree Days ◽  
Thermal Threshold ◽  
Thermal Requirements ◽  
Different Temperatures ◽  
Males And Females ◽  
Telenomus Remus

This research aimed at studing Telenomus remus Nixon biology reared on Spodoptera frugiperda (J.E. Smith) eggs at different temperatures. Based on the development of the cycle (egg-adult), the thermal requirements and the number of parasitoid generations at constant temperatures were determined. Initially, 24-hour-old S. frugiperda eggs were submitted to parasitism by T. remus during 5 h, being then transferred to acclimatized chambers regulated at 15, 20, 25, 28, 31, and 35°C. The cycle (egg to adult) was influenced by temperature varying from 8.3±0.01 to 47.2±0.01 for females and 8.1±0.01 to 46.8±0.01 days for males at 31 and 15°C, respectively. The emergency (%) was also influenced by temperature. A reduction in emergency was observed at 15°C and no emergency at 35°C. T. remus sex ratio was not influenced by temperature. Sexual rate was not changed by temperature. Regarding to thermal requirements, thermal constant (K) and inferior thermal threshold (Tb) were higher for T. remus females (158.88 degree-days and 12.5°C) when compared to males (154.12 degree-days and 12.6°C). The estimated number of T. remus generation per year for males and females at laboratory conditions was 5.6 and 5.6, 16.9 and 17.3, 28.3 and 29.0, 35.1 and 36.0, 39.6 and 40.7 at 15, 20, 25, 28, and 31oC, respectively.

DEVELOPMENT OF THE CARROT RUST FLY, PSILA ROSAE (DIPTERA: PSILIDAE), RELATIVE TO TEMPERATURE IN THE LABORATORY

1981 ◽  
Vol 113 (7) ◽  
pp. 569-574 ◽  
Author(s):  
A. B. Stevenson
Keyword(s):  
Effect Of Temperature ◽  
Thermal Constant ◽  
Degree Days ◽  
Psila Rosae ◽  
Egg Hatch ◽  
Rate Of Development ◽  
Threshold Temperatures ◽  
Thermal Constants ◽  
The Relationship

AbstractThe effect of temperature on development of the carrot rust fly, Psila rosae (F.), was determined at constant temperatures in the laboratory. The relationship between rate of development and temperature was essentially linear from 10° to 17.5°C but began to diverge from linearity between 17.5° and 20°C. Estimated threshold temperatures (t) and thermal constants (K) for development of overwintered pupae were 2.3°C and 319 degree-days (dd) for first emergence and 1.8°C and 368 dd for 50% emergence. For laboratory-reared stages, t and K values were 4.1°C and 102 dd for egg hatch, 2.0°C and 642 dd for development from egg to mature larvae, and 3.0°C and 107 dd for pupation. Development in the laboratory from egg (less than 24 h old) to adult was completed in 59, 70, and 81 days at 20°, 17.5°, and 15°C respectively; no threshold or thermal constant was estimated because few or no individuals completed development to adult at 12.5° or 10°C within expected times, presumably because diapause was induced at these temperatures.

Exploring the Potential Impact of Sentence-Level Comprehension and Sentence-Level Fluency on Deaf Students' Passage Comprehension

2020 ◽  
Vol 63 (7) ◽  
pp. 2281-2292
Author(s):  
Ying Zhao ◽  
Xinchun Wu ◽  
Hongjun Chen ◽  
Peng Sun ◽  
Ruibo Xie ◽  
...  
Keyword(s):  
Independent Predictor ◽  
Vocabulary Knowledge ◽  
Group Differences ◽  
Regression Analyses ◽  
Deaf Students ◽  
Mediating Role ◽  
Sentence Level ◽  
Mediating Mechanisms ◽  
Potential Impact ◽  
The Relationship

Purpose This exploratory study aimed to investigate the potential impact of sentence-level comprehension and sentence-level fluency on passage comprehension of deaf students in elementary school. Method A total of 159 deaf students, 65 students ( M age = 13.46 years) in Grades 3 and 4 and 94 students ( M age = 14.95 years) in Grades 5 and 6, were assessed for nonverbal intelligence, vocabulary knowledge, sentence-level comprehension, sentence-level fluency, and passage comprehension. Group differences were examined using t tests, whereas the predictive and mediating mechanisms were examined using regression modeling. Results The regression analyses showed that the effect of sentence-level comprehension on passage comprehension was not significant, whereas sentence-level fluency was an independent predictor in Grades 3–4. Sentence-level comprehension and fluency contributed significant variance to passage comprehension in Grades 5–6. Sentence-level fluency fully mediated the influence of sentence-level comprehension on passage comprehension in Grades 3–4, playing a partial mediating role in Grades 5–6. Conclusions The relative contributions of sentence-level comprehension and fluency to deaf students' passage comprehension varied, and sentence-level fluency mediated the relationship between sentence-level comprehension and passage comprehension.

ЗУБРЫ НА СЕВЕРЕ РОССИИ — НАСТОЯЩЕЕ И БУДУЩЕЕ

2019 ◽  
pp. 42-44
Author(s):  
I.V. GUSAROV ◽  
V.A. OSTAPENKO ◽  
T.V. NOVIKOVА
Keyword(s):  
Biological Diversity ◽  
Climatic Conditions ◽  
Economic Consequences ◽  
European Bison ◽  
Rare And Endangered Species ◽  
The North ◽  
Rare And Endangered ◽  
Relationship Of ◽  
First Time ◽  
The Relationship

Впервые в мире создана популяция зубров на территории 60 градусов северной широты. В новых климатических условиях разведения и сохранения зубров определены и проанализированы факторы существования вида на севере Европейской части РФ. Выявлены признаки, динамика численности, которые являются составной частью системы, предназначенной для управления биоразнообразием. Интродукция, являясь процессом введения в экосистему нехарактерных для нее видов, может усиливать изменения биоценозов как положительно, так и отрицательно. Насколько быстро и успешно проходит процесс адаптации заселенного вида, и усматривается его влияние на окружающую среду зависит дальнейшее существование зубров и в целом биоразнообразия. В статье обсуждаются вопросы взаимоотношения зубров с другими видами копытных и хозяйственной деятельностью человека, а также дальнейшим использованием зубров в сельскохозяйственном производстве. Пластичность зубров, выявление изменений и их анализ при вселении видов в новые условия обитания необходимы не только для определения развития или деградации биоценозов и в целом экосистемы, но и прогноза социально-экономических последствий интродукции как одного из методов сохранения редких и исчезающих видов фауны.For the first time in the world, a bison population has been created in an area of 60 degrees north latitude. In the new climatic conditions of breeding and preservation of bison, the factors of the species existence in the north of the European part of the Russian Federation are identified and analyzed. The signs, dynamics of abundance, which are an integral part of the system designed to manage biodiversity are identified, since the preservation of biological diversity on the planet is one of the main problems of our time. Introduction, being the process of introducing non-typical species into an ecosystem, can enhance changes in biocenoses, both positively and negatively. The question posing sounds especially when it comes to such a large hoofed animal as the European bison. How quickly and successfully the process of adaptation of the universe takes place and its environmental impact is seen depends on the continued existence of bison and biodiversity in general. The article discusses the relationship of bison with other types of ungulates and human activities, as well as the further use of bison in agricultural production. How these issues will be resolved positively depends on the future of these animals. Thus, the plasticity of bison, the identification of changes and their analysis, with the introduction of species into new habitat conditions is necessary not only to determine the development or degradation of biocenoses and the ecosystem as a whole, but also to predict the socio-economic consequences due to the introduction as one of the methods of preserving rare and endangered species of fauna.

THE MODEL FOR MANAGING INVESTMENTS IN THE MOSCOW ENVIRONMENT BASED ON A POWER REGRESSION EQUATION

2020 ◽  
Vol 2 (7) ◽  
pp. 91-99
Author(s):  
E. V. KOSTYRIN ◽  
◽  
M. S. SINODSKAYA ◽  
Keyword(s):  
Solid Waste ◽  
Influencing Factors ◽  
Pair Correlation ◽  
Approximation Error ◽  
Regression Equation ◽  
Regression Equations ◽  
The Impact ◽  
The Relationship ◽  
Average Approximation ◽  
Average Approximation Error

The article analyzes the impact of certain factors on the volume of investments in the environment. Regression equations describing the relationship between the volume of investment in the environment and each of the influencing factors are constructed, the coefficients of the Pearson pair correlation between the dependent variable and the influencing factors, as well as pairwise between the influencing factors, are calculated. The average approximation error for each regression equation is determined. A correlation matrix is constructed and a conclusion is made. The developed econometric model is implemented in the program of separate collection of municipal solid waste (MSW) in Moscow. The efficiency of the model of investment management in the environment is evaluated on the example of the growth of planned investments in the activities of companies specializing in the export and processing of solid waste.

scholarly journals Review article: Jesus’ resurrection in Joseph’s garden

2010 ◽  
Vol 66 (1) ◽  
Author(s):  
Estelle Dannhauser
Keyword(s):  
Developmental Stages ◽  
Faith Community ◽  
Review Article ◽  
Historical Jesus ◽  
Life And Death ◽  
The Relationship ◽  
Community Church

The article is a lengthy review of the book Jesus’ resurrection in Joseph’s garden by P.J.W. (Flip) Schutte. The book represents a quest to trace the relationship between Jesus’ resurrection, myth and canon. Schutte finds the origin of events underlying the biblical canon in proclamation. His focus in the book is the proclamation of the death and resurrection of Christ, which, in its developmental stages, hinged on the life and death of the historical Jesus. Proclamation developed into a mythical narrative that became the foundational myth for the Christ cult, validating its existence and rituals. With the growth and institutionalisation of the faith community (church), came an increased production of literature, causing the power-wielding orthodoxy to identify a body of literature containing the ‘truth’ and ‘correct teaching’, thus establishing the authoritative canon. In, through, behind and beyond Jesus of Nazareth, Schutte has perceived a canon behind the canon: a God of love. In Jesus, the man of myth with historical roots who has become to us the observable face of God, Schutte confesses the kerygma to open up before him. The proclamation therefore extends an invitation to join in a mythological experience and an encounter with God whose love is preached in the metaphor called Easter.

scholarly journals Sodium Metasilicate Cemented Analogue Material and Its Mechanical Properties

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Songlin Yue ◽  
Yanyu Qiu ◽  
Pengxian Fan ◽  
Pin Zhang ◽  
Ning Zhang
Keyword(s):  
Complex Geometry ◽  
Sodium Metasilicate ◽  
Raw Material ◽  
Fine Aggregate ◽  
Regression Equations ◽  
Deformation And Failure ◽  
Orthogonal Experiments ◽  
Low Modulus ◽  
New Type ◽  
The Relationship

Analogue material with appropriate properties is of great importance to the reliability of geomechanical model test, which is one of the mostly used approaches in field of geotechnical research. In this paper, a new type of analogue material is developed, which is composed of coarse aggregate (quartz sand and/or barite sand), fine aggregate (barite powder), and cementitious material (anhydrous sodium silicate). The components of each raw material are the key influencing factors, which significantly affect the physical and mechanical parameters of analogue materials. In order to establish the relationship between parameters and factors, the material properties including density, Young’s modulus, uniaxial compressive strength, and tensile strength were investigated by a series of orthogonal experiments with hundreds of samples. By orthogonal regression analysis, the regression equations of each parameter were obtained based on experimental data, which can predict the properties of the developed analogue materials according to proportions. The experiments and applications indicate that sodium metasilicate cemented analogue material is a type of low-strength and low-modulus material with designable density, which is insensitive to humidity and temperature and satisfies mechanical scaling criteria for weak rock or soft geological materials. Moreover, the developed material can be easily cast into structures with complex geometry shapes and simulate the deformation and failure processes of prototype rocks.

scholarly journals The Respiration of some Planktonic copepods II. The Effect Of Temperature

1953 ◽  
Vol 31 (3) ◽  
pp. 447-460 ◽  
Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont
Keyword(s):  
Respiratory Rate ◽  
The Body ◽  
The Other ◽  
Effect Of Temperature ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Different Temperatures ◽  
Planktonic Copepods ◽  
The Difference ◽  
The Relationship

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.

Sign in / Sign up

Export Citation Format

Share Document