scholarly journals Differential distribution of resources for females on a dioecious plant affects the small–scale distribution of male of an oligolectic bee

2019 ◽  
pp. 267-277 ◽  
Author(s):  
C. Polidori ◽  
M. Federici
Keyword(s):  
Limited Resource ◽  
Scramble Competition ◽  
Small Scale ◽  
Nest Density ◽  
Home Ranges ◽  
Differential Distribution ◽  
Male Density ◽  
Distribution Of Resources ◽  
Oligolectic Bees ◽  
The Relationship

Females of the solitary digger bee Andrena florea Fabricius, 1793 (Hymenoptera, Andrenidae) nest in aggregations and collect pollen almost exclusively on dioecious plants of the genus Bryonia, making this species a good model to study the relationship between nest density, male density, male behaviour and female lecty. At a study site in the valley of the river Serio, in Italy, an aggregation of this bee showed low density of randomly distributed nests and was closely surrounded by B. dioica plants. Female nectar foraging and male feeding and mate–searching activity, confined to the host plants, peaked at similar hours across the day, while female pollen foraging peaked earlier. Males fed on plants of both sexes but seemed to perch waiting for females more frequently on male B. dioica leaves. Individual males more often visited only one of the male plants, for up to four days; here they did not interact aggressively with conspecifics, suggesting scramble competition in resource–based home ranges and not territoriality. These findings are preliminarily in accordance with the predicted resource–based rendez–vous sites at low nest density for oligolectic bees and the predicted occurrence of scramble competition in case of high male density. Additionally, males would maximize their mating opportunity by mainly perching on male plants, the only source of the most limited resource for females (pollen).

Habitat use by female western roe deer (Capreolus capreolus): influence of resource availability on habitat selection in two contrasting years

2010 ◽  
Vol 88 (11) ◽  
pp. 1052-1062 ◽  
Author(s):  
M. Pellerin ◽  
C. Calenge ◽  
S. Saïd ◽  
J.- M. Gaillard ◽  
H. Fritz ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Habitat Use ◽  
Resource Availability ◽  
Roe Deer ◽  
Habitat Type ◽  
Capreolus Capreolus ◽  
Home Ranges ◽  
Distribution Of Resources ◽  
The Relationship ◽  
Selection Of

In most previous studies of habitat selection, the use of a given habitat type is assumed to be directly proportional to its availability. However, the use and (or) the selection of a given habitat may be conditional on the availability of that habitat. We aim here to (i) identify the environmental variables involved in habitat selection, (ii) identify classes of individuals with similar patterns of habitat selection, and (iii) assess whether habitat use changes with changing availability of habitat types, within monthly home ranges of female western roe deer ( Capreolus capreolus (L., 1758)). We found that some females adjust their habitat use according to the distribution of resources within habitats. Females with similar home ranges in terms of resource quantity and quality showed similar patterns of habitat selection. Differences in habitat use between 2 years with contrasting resource availability showed that temporal changes of environmental conditions influenced the pattern of habitat selection by female roe deer. Habitat selection also differed between periods of the life cycle likely because of contrasted energy requirements. This study shows that the relationship between habitat use by herbivores and habitat availability is nonproportional, and that the availability of resources influences use mostly at intermediate values.

scholarly journals Maternal toxoplasmosis and the risk of childhood autism: serological and molecular small-scale studies

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jamila S. Al Malki ◽  
Nahed Ahmed Hussien ◽  
Fuad Al Malki
Keyword(s):  
Neurodevelopmental Disorders ◽  
Repetitive Behavior ◽  
Saudi Arabian ◽  
Childhood Autism ◽  
Small Scale ◽  
Autistic Children ◽  
High Prevalence ◽  
Life Threatening ◽  
The Relationship ◽  
Delayed Language Development

Abstract Background Toxoplasmosis resulting from infection with the Toxoplasma parasite has become an endemic disease worldwide. Recently, a few studies have reported a high prevalence of Toxoplasmosis infections among Saudi Arabian women. This disease could become life threatening for pregnant women and for immunodeficient people. There is evidence that infections during pregnancy, especially in the early stages, are associated with neurodevelopmental disorders. Autism disorder represents one of the most common neurodevelopmental disorders worldwide; it is associated with delayed language development, weak communication interaction, and repetitive behavior. The relationship between prenatal toxoplasmosis and autism in childhood remains unclear. The present study aims to report a link between maternal toxoplasmosis and autistic offspring among Saudi Arabian women. Method Blood samples (36 maternal, 36 from their non-autistic children, and 36 from their autistic children) were collected for serological and molecular evaluation. Results A toxoplasmosis infection was reported for 33.34% of participants using an ELISA assay (5.56% IgG+/IgM+, 11.11% IgG−/IgM+, and 16.67% IgG+/IgM-); however, a nested PCR assay targeting B1 toxoplasmosis specific genes recorded positive tests for 80.56% of the samples. In addition, the present study detected several points of mutation of mtDNA including NADH dehydrogenase (ND1, ND4) and Cyt B genes and the nDNA pyruvate kinase (PK) gene for autistic children infected with toxoplasmosis. Conclusion Considering previous assumptions, we suggest that a maternal toxoplasmosis infection could have a role in the development of childhood autism linked to mtDNA and nDNA impairment.

Hydrostatic Collapse Pressure and Radial Collapse Force Comparisons for Ultra-Deepwater Pipelines

2014 ◽  
Author(s):  
Marco A. P. Rosas ◽  
Ana Paula F. Souza ◽  
Marcos V. Rodrigues ◽  
Danilo Machado L. da Silva
Keyword(s):  
Numerical Models ◽  
Research Work ◽  
Compressive Force ◽  
Quadratic Function ◽  
Radial Force ◽  
Small Scale ◽  
Collapse Pressure ◽  
First Results ◽  
Specimen Test ◽  
The Relationship

In this paper the behavior and the relationship between hydrostatic collapse pressure and diametrically opposed radial compressive force for pipelines were analyzed. This study presents an introduction of a research work aimed to assess the pipeline collapse pressure based on the radial collapse force. Initially the hydrostatic collapse pressure is analyzed, for pipes with different diameter to wall thickness ratio (D/t) and ovalities, using classical assessment (DNV method) and numerical models (FE). Then, the compressive radial force is also analyzed using numerical models validated by a small-scale ring specimen test. After that, the relationship between hydrostatic collapse pressure and compressive radial force is discussed. These first results show that the radial force is a quadratic function of the collapse pressure.

scholarly journals التنمية الإقتصادية والسلام المفهوم والاستراتيجيات

2021 ◽  
Author(s):  
ali ahmed mohammed
Keyword(s):  
Sustainable Development ◽  
Economic Development ◽  
Human Development ◽  
Political Development ◽  
The Other ◽  
Reconstruction Process ◽  
Distribution Of Resources ◽  
The Relationship ◽  
Economic Development Strategies ◽  
Peace And Development

الملخص تعد التنمية الاقتصادية ذات أهمية كبيرة حيث حظيت بالإهتمام من قبل الدارسين والباحثين والاقتصاديين داخل الدولة منذ عقود، وخصوصاً بعد انتهاء الحرب العالمية الثانية، عندما بدأت الدول التي عانت من هذه الحرب بعمليات إعادة الاعمار، ومن ثم بعد ذلك بدأت تظهر الانواع الاخرى من التنمية، كالتنمية المستدامة والتنمية البشرية، وبدأ الحديث عن التنمية الاجتماعية والسياسية كذلك، وعلى الرغم من ذلك الا ان هناك تحديات كثيرة تقف في طريق التنمية الاقتصادية كالفقر والتخلف، ولا بد من اتباع إستراتيجيات معينة لتحقيق التنمية الاقتصادية وبالتالي تحقيق السلام، حيث ان التنمية والسلام هما ذات علاقة وثيقة ببعضهما، نظرا لان معظم الحروب والنزاعات تنشب لأسباب اقتصادية اما للسيطرة على الموارد او بسبب التوزيع غير العادل لها، ويتناول هذا البحث إستراتيجيات التنمية الاقتصادية المحققة للسلام، مع بيان العلاقة بين السلام والتنمية، والمفاهيم المرتبطة بهما.Summary Economic development has a great importance, it has the First attention by scholars, researchers and economists within the state, especially after the end of the WWII, when the countries that suffered from this war began the reconstruction process, then the other types of Development began to appear, such as sustainable development and human development, and also they began to talk about social and political development. However, many challenges stand in the way of economic development such as poverty and underdevelopment, and certain strategies must be followed to achieve economic development and thus achieve Peace, peace and development are closely interrelated, since most wars and conflicts arise for economic reasons or either for the control of resources or because of unfair distribution of resources. This research deals with the economic development strategies for peace, with explanation of the relationship between peace and development.

scholarly journals The Impact of Phenological and Artificial Factors on Seed Quality in a Nematode-resistant Pinus densiflora Seed Orchard

2009 ◽  
Vol 58 (1-6) ◽  
pp. 145-152 ◽  
Author(s):  
H. Ozawa ◽  
J. Watanabe ◽  
H. Chen ◽  
K. Isoda ◽  
A. Watanabe
Keyword(s):  
Seed Quality ◽  
Pinus Densiflora ◽  
Seed Orchard ◽  
Small Scale ◽  
Maternal Contribution ◽  
Paternal Parent ◽  
A Minor ◽  
The Impact ◽  
The Relationship ◽  
Seed Resistance

Abstract To clarify the relationship between the impact of phenological and/or artificial factors on seed quality, we measured the numbers of strobili on nematode-resistant Pinus densiflora clones grown in an immature and relatively small scale (700 m2) seed orchard. In addition, we established the clonal identities of all ramets, identified the paternal parent of the seeds, and assessed the resistance of seedlings to nematode infection. We also clarified the quantitative differences of strobili among clones; one clone produced 86.4% and 70.8% of all male strobili and female strobili, respectively. However, given that the total contamination ratio of the orchard was 82.0%, immigrant pollen had a larger impact on the success of actual crossing than phenology. Seedlings with a resistant maternal parent were resistant, even when their paternal parent was from outside the orchard. Two unselected clones were also planted in the seed orchard, one of which was not resistant and was associated with a maternal contribution of 34.7% of all seed stock. These findings suggest that, despite having a large impact on the crossing, immigrant pollen has a minor impact on seed resistance. Conversely, unselected and nonresistant clones have a marked impact on seed resistance. We concluded that artificial factors have larger impact on the seed quality than phenological factors in this orchard and the seeds will be of sufficient quality for supplying the market once nonresistant clones have been removed from the orchard.

scholarly journals Challenging Teachers’ Pedagogic Practice and Assumptions about Social Media

2017 ◽  
Vol 21 (2) ◽  
Author(s):  
Helen C. Cartner ◽  
Julia L. Hallas
Keyword(s):  
Professional Development ◽  
Social Media ◽  
Online Course ◽  
Small Scale ◽  
Pedagogical Practice ◽  
Critical Reasoning ◽  
Professional Development For Teachers ◽  
Effective Technology ◽  
The Relationship

This article describes an innovative approach to professional development designed to challenge teachers’ pedagogic practice and assumptions about educational technologies such as social media. Developing effective technology-related professional development for teachers can be a challenge for institutions and facilitators who provide this support. To contend with this challenge, we drew on Bain’s (2004) “baker’s dozen” questions to guide the design of an online postgraduate course for teachers. This article discusses the design of the online course and what teachers came to understand about the relationship between social media and teaching as a result of completing the course activities. This small-scale case study utilised qualitative data from three cohorts of participating teachers and found that teachers do change their pedagogical practice and assumptions about social media for their own teaching contexts when they engage in course activities that challenge their existing mental models and encourage critical reasoning and reflection on learning.

scholarly journals Finding One’s Place in a Host Space: A Small-Scale Study of Cultural Integration and Language Maintenance Among Croatian Immigrants in Canada

2021 ◽  
Vol 12 (1) ◽  
pp. 37-76
Author(s):  
Sanja Škifić ◽  
Antonia Strika
Keyword(s):  
British Columbia ◽  
Language Acquisition ◽  
Language Use ◽  
Language Maintenance ◽  
Small Scale ◽  
Cultural Integration ◽  
The Relationship ◽  
Cognitive Perspectives ◽  
Insight Into

This paper focuses on sociocultural and language-related issues among Croatian immigrants in Canada. It presents the results of thestudy conducted from November 2018 to February 2019 among Croatian immigrants of different generations in Ontario and British Columbia. Questions included in the questionnaire refer to different aspects of participants’ identity and their (families’) immigration, as well as issues related to their attitudes towards the homeland and engagement in Croatian associations in Canada. Participants were asked to provide feedback on their language acquisition, competence and use, as well as evaluations of the importance of the Croatian language for their identity. The questionnaire also contained questions related to participants’ language use from emotional and cognitive perspectives. Conclusions drawn on the basis of the collected data provide an insight into Croatian immigrants’ language use, the extent of cultural integration and language maintenance, and their attitudes towards the relationship between identity and language.

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