The relationship between retinal and tectal growth in larval Xenopus: implications for the development of the retino-tectal projection

Development ◽  
1979 ◽  
Vol 53 (1) ◽  
pp. 103-143
Author(s):  
R. M. Gaze ◽  
M. J. Keating ◽  
A. Ostberg ◽  
S-H Chung

The modes of retinal and tectal histogenesis, as well as the patterns of terminal distribution of optic axons in larval Xenopus were studied, using anatomical techniques. We show that the retina grows by adding strips of cells at its ciliary margin. The pattern of retinal growth is asymmetrical along the dorso-ventral axis of the retina. On the other hand, the ectum grows by adding newly formed cells caudo-medially. The most rapid tectal growth takes place between stages 50 and 53, and thereafter only a small proportion of cells are added near the midline of the caudal tectum. Despite such incongruent modes of retinal and tectal growth, retinotopic order is maintained throughout larval life. We present here further evidence supporting the idea that connexions between the arrays of retinal and tectal cells shift progressively caudo-medially on the tectum during the period of growth. When the temporal pole of the retina is destroyed at various developmental stages, the density of degenerating synapses is always highest in the rostral pole of the tectum. Moreover, optic terminals stemming from the central retina spread caudally, invading newly maturing regions of the tectum. Quantitative analysis of the terminal distributions of optic axons suggest that orderly shifts in synaptic contacts between optic axons and tectal dendrites take place in the course of development. Ultrastructural observations on the maturing tectal neuropil are consistent with this view.

Proceedings ◽  
2019 ◽  
Vol 30 (1) ◽  
pp. 9
Author(s):  
Sebastiano Trevisani

Modern Earth Scientists need also to interact with other disciplines, apparently far from the Earth Sciences and Engineering. Disciplines related to history and philosophy of science are emblematic from this perspective. From one side, the quantitative analysis of information extracted from historical records (documents, maps, paintings, etc.) represents an exciting research topic, requiring a truly holistic approach. On the other side, epistemological and philosophy of science considerations on the relationship between geoscience and society in history are of fundamental importance for understanding past, present and future geosphere-anthroposphere interlinked dynamics.


2021 ◽  
Author(s):  
◽  
Kerry Alistair Nitz

<p>Iris Hanika’s commercially and critically successful novel Treffen sich zwei makes use of several techniques in the characterisation of its protagonists. Many of its reviews focus on the author’s deliberate placement of links to a wider literary context. Their interest extends from questions of genre-mixing through to the identification of direct quotes from other authors’ works. The critical preoccupation with intertexts demonstrates their importance for the readers’ response to the novel. More specifically, certain reviews highlight the important role intertexts play in the characterisation of the protagonists. This study catalogues the intertexts, metaphors and parodies in Treffen sich zwei and, by means of quantitative analysis, identifies high-level patterns in the use of these techniques. In particular, patterns are identified between, on the one hand, the different narrative functions of the intertexts and, on the other hand, the different ways in which they are interwoven in the text. The data also shows that distinct patterns are associated with each of the two protagonists and that certain patterns change in the course of the novel in parallel with the changes in the relationship between them. This quantitative evidence is supported by a more detailed, qualitative approach, which examines how specific intertexts or metaphors are used for the purposes of characterisation. In addition, variations in voice are used to distinguish the two main protagonists in a manner consistent with the intertexts and metaphors. It is thanks to the combination of these techniques that the theme of meeting encapsulated in the title, Treffen sich zwei, is woven into the textual fabric of the novel.</p>


Author(s):  
Amparo García Cuadrado

This article approaches the study of the private library of the Murcian land surveyor Francisco Falcón de los Reyes, from the first half of the eighteenth century, which constitutes a clear example of the relationship between education and written culture. From the data extracted from a postmortem inventory and the subsequent appraisal and partition of goods among the heirs, we carried out a quantitative and qualitative analysis of said library. First, the text provides a biographical profile of this geometer, a descendant of slaves (new Christians), and describes the formative precariousness of these professionals in their time. The quantitative analysis of the bibliographic collection and its comparison with other private collections from similar socioeconomic fields indicate the importance of this particular collection. The qualitative study of authors and titles shows, on one hand, the high degree of mathematical training of the subject, who is shown to be a recipient of the fundamentally Valencian pre-illustrated reformist scientific mainstream, and, on the other hand, the purpose with which those books were incorporated into the funds of the collection. Together with the library, which we could call professional, due to its scientific nature, the inventoried religious matter in the form of printed documents makes up another interesting part of the collection, one of a catechetical nature in its various formative levels


2021 ◽  
Author(s):  
◽  
Kerry Alistair Nitz

<p>Iris Hanika’s commercially and critically successful novel Treffen sich zwei makes use of several techniques in the characterisation of its protagonists. Many of its reviews focus on the author’s deliberate placement of links to a wider literary context. Their interest extends from questions of genre-mixing through to the identification of direct quotes from other authors’ works. The critical preoccupation with intertexts demonstrates their importance for the readers’ response to the novel. More specifically, certain reviews highlight the important role intertexts play in the characterisation of the protagonists. This study catalogues the intertexts, metaphors and parodies in Treffen sich zwei and, by means of quantitative analysis, identifies high-level patterns in the use of these techniques. In particular, patterns are identified between, on the one hand, the different narrative functions of the intertexts and, on the other hand, the different ways in which they are interwoven in the text. The data also shows that distinct patterns are associated with each of the two protagonists and that certain patterns change in the course of the novel in parallel with the changes in the relationship between them. This quantitative evidence is supported by a more detailed, qualitative approach, which examines how specific intertexts or metaphors are used for the purposes of characterisation. In addition, variations in voice are used to distinguish the two main protagonists in a manner consistent with the intertexts and metaphors. It is thanks to the combination of these techniques that the theme of meeting encapsulated in the title, Treffen sich zwei, is woven into the textual fabric of the novel.</p>


Author(s):  
Sergey Andreyev

The article studies the degree of description nominality in fiction based on the usage of the two most frequent attributes: adjectival and nominal ones. The former are adnominals, expressed by adjectives or adjectival phrases (adjectives with dependent words), the latter are of-N constructions (in English texts) and genitive case of nouns (in Russian texts). The data-base includes extracts from highly popular English and Russian women authors: R. Galbraith, S. Kinsella, A. Marinina and T. Ustinova.The research is based on a quantitative analysis of data with the use of a number of statistical measures. The Busemann coefficient is used to study the relationship of adjectival and nominal attributes and the power function is necessary for fitting the distribution of distances of attributes counted within separate sentences.The analysis has demonstrated that the frequency of adjectival attributes as expected exceeds that of nominal attributes. However, the relationship of these types of attributes is highly different for the abovementioned authors. The results have proved that there is no difference in the proportion of these two attribute types between English and Russian texts whereas this feature distinguishes the styles of R.Galbraith and A. Marinina on the one hand, and S. Kinsella and T. Ustinova on the other hand.The research of the distance dynamics of the two given attributes from the beginning to the end of the works has shown big differences in the style of the authors, too. In a number of cases the tendency for compensation is observed while a drop in the frequency of one attribute type correlates with the rise in frequency of the other one.


2006 ◽  
Vol 49 (6) ◽  
pp. 989-999 ◽  
Author(s):  
Roberta Hehl de Sylos Cintra ◽  
José Eduardo dos Santos ◽  
Luiz Eduardo Moschini ◽  
José Salatiel Rodrigues Pires ◽  
Carlos Henke-Oliveira

A qualitative and quantitative analysis of the environmental damages occurrences was conducted through the lawful documents established for charging at the State Prosecution Service of São Carlos city, State of São Paulo, during 1991 - 2000, to understand the relationship between environmental problems and the current development actions. The environmental damage identified were grouped into nine classes, where deforestation was prevailing in each year along the period of study. Of the total number of deforestation occurrences, 180 was related to areas smaller than 5 ha. It corresponded to 110.35 ha of the total deforested area. The other 37 were associated with areas higher than 5 ha, equivalent to 1,013.27 ha. The registers of environmental damages in the period in a rough estimate, corresponded to a mediam loss of 5.91 ± 4.14 ha/occurrence and of 112.36 ± 91.73 ha/year of deforested area.


2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0004
Author(s):  
Cameron A. Trotter ◽  
Justin J. Greiner ◽  
Tim McGuine ◽  
Geoffrey S. Baer

Background: Softball is a popular sport among youth female athletes. While multiple youth baseball studies have evaluated the relationship of injury to pitch counts, there is a paucity of literature for youth softball. In contrast to the numerous youth baseball leagues adhering to pitching guidelines, pitch counts are frequently not enforced in youth softball which results in pitchers with exceedingly high volumes. Purpose: The purpose of this study was to perform a quantitative analysis of pitching volume in youth softball players. We hypothesized that the majority of pitches would be thrown by a small proportion of pitchers on each team. Methods: Seventy youth softball teams including 538 pitchers competing in age brackets eight and under (8U) to fourteen and under (14U) between Spring 2017 and Fall 2019. Game dates and pitch counts were collected for each player using an electronic application. Games played on two or more consecutive days were defined as a tournament. The three highest-volume pitchers from each team defined by total season pitches were analyzed for comparison to the average pitcher. Results: 538 pitchers on 70 teams were included. The average pitcher threw 813 pitches per year and appeared in 20.0% of games and the average high-volume pitcher threw 2500 pitches per year and appeared in 54.5% of games. The highest-volume pitcher from each team threw 40% of all recorded pitches, the second highest 27.2%, and the third highest 15.2%, totaling 82.4% of all team pitches. Single day pitch counts of >100 and >200 occurred in 17.7%, and 1.1% of same day games with the average pitcher and in 31.2%, and 2.4% of same day games with the average highest-volume pitcher. Tournament pitch counts of >100 and >200 occurred in 51.0% and 13.8% of tournaments with the average pitcher and in 81.4% and 30.8% of tournaments with the average highest-volume pitcher. The average and highest-volume pitcher threw pitches in two or more games on the same day in 37.5% and 48.6% of possible games while pitching two or more consecutive days in 64.0% and 79.6% of possible games, respectively. Conclusion: Softball pitchers throw high volumes of pitches while also pitching multiple days consecutively. A disparity among pitchers on softball teams exists as 82.4% of team pitches are thrown by three pitchers. These high-volume pitchers may be engaging in unsustainable pitching practices that could predispose to injury. Tables: [Table: see text]


Crisis ◽  
2011 ◽  
Vol 32 (5) ◽  
pp. 246-253 ◽  
Author(s):  
Gretchen E. Ely ◽  
William R. Nugent ◽  
Julie Cerel ◽  
Mholi Vimbba

Background: The relationship between suicidal thinking and adolescent dating violence has not been previously explored in a sample of adolescent abortion patients. Aims: This paper highlights a study where the relationship between dating violence and severity of suicidal thinking was examined in a sample of 120 young women ages 14–21 seeking to terminate an unintended pregnancy. Methods: The Multidimensional Adolescent Assessment Scale and the Conflict in Adolescent Relationships Scale was used to gather information about psychosocial problems and dating violence so that the relationship between the two problems could be examined, while controlling for the other psychosocial problems. Results: The results suggest that dating violence was related to severity of suicidal thinking, and that the magnitude of this relationship was moderated by the severity of problems with aggression. Conclusions: Specifically, as the severity of participant’s general problems with aggression increased, the magnitude of the relationship between dating violence and severity of suicidal thinking increased. Limitations of the study and implications for practice are discussed.


Author(s):  
Melanie K. T. Takarangi ◽  
Deryn Strange

When people are told that their negative memories are worse than other people’s, do they later remember those events differently? We asked participants to recall a recent negative memory then, 24 h later, we gave some participants feedback about the emotional impact of their event – stating it was more or less negative compared to other people’s experiences. One week later, participants recalled the event again. We predicted that if feedback affected how participants remembered their negative experiences, their ratings of the memory’s characteristics should change over time. That is, when participants are told that their negative event is extremely negative, their memories should be more vivid, recollected strongly, and remembered from a personal perspective, compared to participants in the other conditions. Our results provide support for this hypothesis. We suggest that external feedback might be a potential mechanism in the relationship between negative memories and psychological well-being.


1994 ◽  
Vol 72 (01) ◽  
pp. 058-064 ◽  
Author(s):  
Goya Wannamethee ◽  
A Gerald Shaper

SummaryThe relationship between haematocrit and cardiovascular risk factors, particularly blood pressure and blood lipids, has been examined in detail in a large prospective study of 7735 middle-aged men drawn from general practices in 24 British towns. The analyses are restricted to the 5494 men free of any evidence of ischaemic heart disease at screening.Smoking, body mass index, physical activity, alcohol intake and lung function (FEV1) were factors strongly associated with haematocrit levels independent of each other. Age showed a significant but small independent association with haematocrit. Non-manual workers had slightly higher haematocrit levels than manual workers; this difference increased considerably and became significant after adjustment for the other risk factors. Diabetics showed significantly lower levels of haematocrit than non-diabetics. In the univariate analysis, haematocrit was significantly associated with total serum protein (r = 0*18), cholesterol (r = 0.16), triglyceride (r = 0.15), diastolic blood pressure (r = 0.17) and heart rate (r = 0.14); all at p <0.0001. A weaker but significant association was seen with systolic blood pressure (r = 0.09, p <0.001). These relationships remained significant even after adjustment for age, smoking, body mass index, physical activity, alcohol intake, lung function, presence of diabetes, social class and for each of the other biological variables; the relationship with systolic blood pressure was considerably weakened. No association was seen with blood glucose and HDL-cholesterol. This study has shown significant associations between several lifestyle characteristics and the haematocrit and supports the findings of a significant relationship between the haematocrit and blood lipids and blood pressure. It emphasises the role of the haematocrit in assessing the risk of ischaemic heart disease and stroke in individuals, and the need to take haematocrit levels into account in determining the importance of other cardiovascular risk factors.


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