scholarly journals Factors affecting the breeding of the field mouse ( Microtus agrestis ). Part III.—Locality

1933 ◽  
Vol 113 (784) ◽  
pp. 486-495 ◽  
Keyword(s):  
Experimental Work ◽  
The Other ◽  
Microtus Agrestis ◽  
Field Mouse ◽  
Factors Affecting ◽  
Intermediate Area ◽  
Forestry Commission ◽  
North And South

The first two papers in this series (1932, a and b ) were descriptions of experimental work. This third paper is based upon observation. In order to study the effect of latitude upon the starting and stopping of breeding, we chose three areas in a nearly north and south line. The most northerly was about 360 miles from the most southerly, and the other area was roughly half way between them. All three areas were elevated grassland belonging to the Forestry Commission, whom we must thank for their kind co-operation, without which the investigation would have been impossible. The most northerly area was at Huntly in Aberdeenshire. The intermediate area was at Newcastleton in Roxburghshire. The most southerly area was at Corris in Merionethshire (see fig. 1.). The Aberdeen and Roxburgh areas were at elevations of about 700 feet, and the Merioneth area at between 500 and 600 feet. Microtus agrestis was caught in each area as nearly as possible every month from January, 1930, to December, 1931. Deep snow and other causes occasionally prevented the monthly trapping in one or other area. On the average 32 Microtus were caught each month during these tow years in Aberdeen, 29 in Roxburgh, and 43 in Merioneth. The total number of mice caught in all three areas was precisely 2500.

scholarly journals Factors affecting the breeding of the field mouse (microtus agrestis). Part II.—Temperature and food

1932 ◽  
Vol 112 (774) ◽  
pp. 39-46 ◽  
Keyword(s):  
Winter Temperature ◽  
Microtus Agrestis ◽  
Field Mouse ◽  
Factors Affecting ◽  
Winter Food ◽  
Temperature Experiment ◽  
Daily Period

Introduction .—In Part I (1931) we described experiments on the effects of light on reproduction in the field mouse. The conditions under which the control and experimental mice were kept was described in full. The control mice were kept for a year under summer conditions of temperature, food and daily period of exposure to light (15 hours), while the experimental mice had the same conditions of temperature and food, but light for only 9 hours daily. We call this the “ winter light ” experiment. The control mice bred throughout the year, but the winter-light mice scarcely at all. Concurrently with the winter light experiment, two other experiments were carried out against the same control. These were the winter temperature experiment and the winter food experiment, which are described in this paper.

Investigation on Polymer Adsorption and Retention in a Polymer Flooded Reservoir

2013 ◽  
Vol 734-737 ◽  
pp. 1200-1203
Author(s):  
Shu Qiang Liu ◽  
Ji Cheng Zhang ◽  
Jin Cheng Xu
Keyword(s):  
Polymer Solution ◽  
Influencing Factors ◽  
Polymer Adsorption ◽  
Solution Concentration ◽  
Injection Rate ◽  
The Other ◽  
Injection Time ◽  
Factors Affecting ◽  
Dynamic Factors ◽  
Polymer Retention

During polymer flooding, certain amount of polymer would be lost. Polymer retention causes sweep volume expanding on one side, it also causes polymer loss on the other. Therefore, it is a very important topic to study the influencing factors of polymer retention. There are many factors affecting polymer retention process. This paper mainly studied the influence from dynamic factors such as polymer solution concentration, injection rate, injection time, injected pv number. This paper investigated the influence of these factors on polymer retention process, and optimized these factors to minimize polymer loss in reservoir.

XXVII.—The Inheritance of Long and Short Wings in the Weevil, Sitona hispidula, with a Discussion of Wing Reduction among Beetles

1928 ◽  
Vol 55 (3) ◽  
pp. 665-735 ◽  
Author(s):  
Dorothy J. Jackson
Keyword(s):  
Experimental Work ◽  
Adult Stage ◽  
Point Of View ◽  
The Other ◽  
Wing Dimorphism ◽  
Wing Reduction ◽  
Hereditary Factors ◽  
The Subject ◽  
The One ◽  
Evolutionary Point

It is well known that in many orders of typically winged insects species occur which in the adult stage are apterous or have the wings so reduced in size that flight is impossible. Sometimes the reduction of wings affects one sex only, as in the case of the females of certain moths, but in the majority of cases it is exhibited by both sexes. In many instances wing dimorphism occurs irrespective of sex, one form of the species having fully developed wings and the other greatly reduced wings. In some species the wings are polymorphic. The problem of the origin of reduced wings and of other functionless organs is one of great interest from the evolutionary point of view. Various theories have been advanced in explanation, but in the majority of cases the various aspects of the subject are too little known to warrant discussion. More experimental work is required to show how far environmental conditions on the one hand, and hereditary factors on the other, are responsible for this phenomenon. Those species which exhibit alary dimorphism afford material for the study of the inheritance of the two types of wings, but only in a few cases has this method of research been utilized.

Factors affecting changes in the intraocular pressure after phacoemulsification surgery

2020 ◽  
Vol 1 (3) ◽  
pp. 166-172
Author(s):  
Rita Dhamankar ◽  
◽  
Suhas S Haldipurkar ◽  
Tanvi Haldipurkar ◽  
Vijay Shetty ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Axial Length ◽  
Anterior Chamber Depth ◽  
The Other ◽  
Factors Affecting ◽  
Factors Associated ◽  
Post Surgery ◽  
Unit Increase ◽  
The Mean

AIM: To assess the changes in anterior chamber parameters and examine the factors associated with changes in the intraocular pressure (IOP) in individuals who have undergone phacoemulsification surgery. METHODS: It is a longitudinal analysis of secondary clinical data collected from 105 non-glaucomatous eyes (82 patients) undergoing a cataract surgery. We studied the association between anterior chamber parameters, grade of cataract, demographics, and changes in the IOP over a period of three weeks. We also evaluated the association between the pressure-depth (PD) ratio and changes in the IOP during this time. RESULTS: The mean age (SD) of the 82 patients was 60.1±7.8y. The mean±standard deviation (SD) IOP was 15.06±3.36 mm Hg pre-operatively; it increased to 15.75±4.21 mm Hg on day one (P=0.20). In the multifactorial models, the mean IOP was -1.715 (95%CI: -2.795, -0.636) mm Hg on day 21±5 compared with the pre-operative values. The anterior chamber depth (ACD), axial length, age, sex, and grade of cataract were not significantly associated with changes in the IOP. Each unit increase in the PD ratio was associated with an increase in the mean IOP by 1.289 mm Hg (95%CI: 0.906, 1.671). After adjusting for pre-operative PD ratio, none of the other variables (ACD, axial length, temporal angle) were significantly associated with changes in mean IOP. CONCLUSION: The PD ratio was the single most important factor associated with the changes in post-operative IOP over three weeks post-surgery.

Narrating The City: spaces Of Urban Change, South London

2008 ◽  
Vol 33 (2) ◽  
pp. 10-17
Author(s):  
Suzanne M. Hall
Keyword(s):  
Inner City ◽  
The Other ◽  
Urban Change ◽  
Spatial Transformation ◽  
Class Culture ◽  
Relationship Of ◽  
The City ◽  
North And South ◽  
Official Data ◽  
Over Time

This paper explores the documentation of social and spatial transformation in the Walworth area, South London. Spatial narratives are the entry point for my exploration, where official and ‘unofficial’ representations of history are aligned to capture the nature of urban change. Looking at the city from street level provides a worldly view of social encounter and spaces that are expressive of how citizens experience and shape the city. A more distanced view of the city accessed from official data reveals different constructs. In overlaying near and far views and data and experience, correlations and contestations emerge. As a method of research, the narrative is the potential palimpsest, incorporating fragments of the immediate and historic without representing a comprehensive whole. In this paper Walworth is documented as a local and Inner City context where remnants and insertions are juxtaposed, where white working class culture and diverse ethnicities experience difference and change. A primary aim is to consider the diverse experiences of groups and individuals over time, through their relationship with their street, neighbourhood and city. In relating the Walworth area to London I use three spatial narratives to articulate the contemporary and historic relationship of people to place: the other side examines the physical discrimination between north and south London, the other half looks at distinctions of class and race and other histories explores the histories displaced from official accounts.

CHROMOSOMES AND DNA OF MICROTUS II. CONFIRMATION OF DELETION OF CONSTITUTIVE HETEROCHROMATIN IN M. AGRESTIS CELLS IN VITRO

1977 ◽  
Vol 19 (3) ◽  
pp. 537-541 ◽  
Author(s):  
J. E. K. Cooper
Keyword(s):  
Somatic Cell ◽  
Cell Line ◽  
Cell Lines ◽  
X Chromosome ◽  
Sex Chromosomes ◽  
Constitutive Heterochromatin ◽  
The Other ◽  
Microtus Agrestis ◽  
C Banding

The distribution of constitutive heterochromatin has been examined by C-banding in two somatic cell lines, grown in vitro, from a female Microtus agrestis. One line retains one intact X chromosome together with the short arm of the other X chromosome, while the other cell line retains only the short arm of one X chromosome. Thus, each cell line has lost substantial amounts of heterochromatin from the sex chromosomes, but this material has been deleted from the cells, and not translocated to other chromosomes. Nonetheless, both cell lines continue to propagate well in vitro.

scholarly journals Using Hotspots Algebra to analyze crime events and their urban context

2017 ◽  
Vol 18 (1) ◽  
pp. 9-26
Author(s):  
Lenin Heredia G. ◽  
Germán E. Bravo C.
Keyword(s):  
Temporal Analysis ◽  
The Other ◽  
Crime Analysis ◽  
Temporal Context ◽  
Urban Context ◽  
Factors Affecting ◽  
Spatial Factors ◽  
Spatial Influence ◽  
Police Agencies ◽  
The Subject

Hotspots analysis is essential in the criminology field and quite important in decisions making for police agencies because it permits the enhancement of allocation of police resources for timely and adequate actions. There exist different techniques for analysis and generation of hotspots, limited by its difficulty to consider other urban and demographic factors that could be the cause of the emergence of these hotspots or their influence over other factors. On the other hand, it is also difficult and unusual to analyze hotspots in a temporal context. This paper seeks, through spatial-temporal operations based in hotspots, to go beyond of classical crime analysis with hotspots, by looking for the spatial influence of other spatial factors over and analyzing also their relationship in a temporal context. The paper initially presents and analyze the performance of various techniques for hotspot generation and determines that STAC technique from CrimeStat is the more suitable for the proposed objective. Then, it defines a hotspot algebra allowing the combined study of crime and spatial factors affecting it and/or been affected by crime events. Temporal analysis includes the hotspots generation for days of the week and/or months in a year. In this way it is possible to study causality relationships and/or correlations among the studied phenomena and the spatial-temporal environment where crime occurs. Therefore, it is possible to define and apply informed actions, primarily concerning the allocation of police resources. Finally, it shows some application examples, thematic as well as temporal analysis, of hotspot algebra using crime data from Bogota for the years 2011 to 2013; finally, some future works in the subject are proposed.

scholarly journals Factors Affecting Language Proficiency in Heritage Language: The Case of Young Russian Heritage Speakers in Spain

2021 ◽  
Vol 14 (2) ◽  
pp. 303-329
Author(s):  
Tamara Vorobyeva ◽  
Aurora Bel
Keyword(s):  
Language Proficiency ◽  
Significant Relationship ◽  
Heritage Language ◽  
Language Use ◽  
Age Of Onset ◽  
The Other ◽  
Significant Variable ◽  
Heritage Speakers ◽  
Factors Affecting ◽  
Family Language

Abstract This study focuses on the issue of language proficiency attainment among young heritage speakers of Russian living in Spain and examines factors that have been claimed to promote heritage language proficiency, namely, age, gender, age of onset to L2, quantity of exposure and family language use. A group of 30 Russian-Spanish-Catalan trilingual children aged 7–11 participated in the study. In order to measure heritage language proficiency (L1 Russian), oral narratives were elicited. The results demonstrated a significant relationship between L1 proficiency and three sociolinguistic variables (age of onset to L2, quantity of exposure and family language use). Additionally, the multiply regression model demonstrated that the only significant variable affecting language proficiency was family language use and it accounted only for 33% of the variation of children’s language proficiency. The study raises the question about what are the other, yet unknown factors, which can affect heritage language proficiency.

scholarly journals The maximum surface area polyhedron with five vertices inscribed in the sphere {\bb S}^{2}

2021 ◽  
Vol 77 (1) ◽  
pp. 67-74
Author(s):  
Jessica Donahue ◽  
Steven Hoehner ◽  
Ben Li
Keyword(s):  
Convex Hull ◽  
Surface Area ◽  
Coordination Polyhedron ◽  
Unit Sphere ◽  
The Other ◽  
Optimal Placement ◽  
The North ◽  
Trigonal Bipyramidal ◽  
Bipyramidal Structure ◽  
North And South

This article focuses on the problem of analytically determining the optimal placement of five points on the unit sphere {\bb S}^{2} so that the surface area of the convex hull of the points is maximized. It is shown that the optimal polyhedron has a trigonal bipyramidal structure with two vertices placed at the north and south poles and the other three vertices forming an equilateral triangle inscribed in the equator. This result confirms a conjecture of Akkiraju, who conducted a numerical search for the maximizer. As an application to crystallography, the surface area discrepancy is considered as a measure of distortion between an observed coordination polyhedron and an ideal one. The main result yields a formula for the surface area discrepancy of any coordination polyhedron with five vertices.

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