Children with absent and unknown fathers (also referred to as undisclosed paternal identity) have distinctly been identified as an interest group due to their increased risk to adverse psychological effects specifically associated with not knowing one’s biological father. It is taken for granted that these children have the freedom of asking their mothers and female caregivers who their fathers are, not taking into account that often there is a tacit rule within these homes whereby the biological father is never discussed. The aim of this exploratory study was to use narratives of mothers and guardians who have children under their care who do not know their true fathers’ identities, in order to explore the range of probable reasons that contribute to maternal caregivers not disclosing the identity of biological fathers. Eight face-to-face, individual interviews were conducted with female participants from varying cultural and socioeconomic backgrounds within the Johannesburg area. The women aged between 33 and 60 years were recruited with the assistance of a non-governmental organisation and from online forums. Interviews were conducted in English or a language that the participants understood and lasted on average an hour. Thematic analysis was used to analyse the transcribed text. The study was undertaken using an interpretive approach that explored the phenomenon of the participants' lived experience of not disclosing. A gendered analysis provided a distanciated framework to review the findings against current societal arrangements. Findings indicated that mothers not disclosing could be linked to the fathers’ behaviour such as inconsistent commitment to the paternal role, denial of paternity and at times, whereabouts were not known limiting what could be conveyed to the children. For this particular study, the nature of the relationship, which is often characterised by the instability of the parents’ relationship at the time of the birth, and subsequent separation, seemed to be a risk factor that a child may not be told who their true father is. Gender-based violence was also found to be contributing to the separation between parents and this in turn created an opportunity for the uninvolved fathers to be absent and unknown to the children. The cultural script that silences women’s experiences of gender-based violence means that father absence that resulted from the violence was difficult to talk about in the homes. The data also gave insight into the differential experiences among the women when dealing with absent, unknown whereabouts and absconded fathers. Although this study was conducted on an exploratory basis, it is suggested that continuous engagement with this topic through research and public discourse would best define how to address the issue. The findings suggest a need to provide mothers who may be considering disclosure with strategies on how to disclose. There is also a broader need to address structural issues that may be contributing towards the phenomenon such as men's violence towards their families.

Cell walls are a distinct feature of plants and their chemical constituents, cellulose, hemicelluloses and lignin, are economically valuable. Plant fibres rich in cellulose, which mainly resides in their cell wall, are traditionally used in making paper and textiles. The changing global economic situation and environmental concerns have imparted necessity for renewable, but at the same time value added cellulosic materials. The Department of Wood Biotechnology, KTH together with its collaborators, have established EST libraries and performed transcript profiling during wood development in poplar, a tree considered as a model for wood development. The majority of the genes upregulated during cellulose biosynthesis encode proteins with known or predictable functions, such as carbohydrate active enzymes (CAzymes). However, some of them encode proteins with unknown functions. Characterization of these genes will potentially give additional opportunities to modify fibre properties. This thesis describes the discovery and characterization of a highly upregulated gene with a previously unknown function in poplar xylem, here denoted PttMAP20. Following its early discovery by mRNA profiling, the characterization was initiated with a thorough bioinformatic analysis, and the knowledge obtained was used to devise techniques for further functional analysis. Specific antibodies were raised, affinity purified and characterized. The antibodies were used as a tool for screening recombinant expression in E. coli and for the cellular localization of the protein in plant tissues, visualized with confocal and transmission electron microscopy. A purification protocol was developed for the expressed protein, followed by biochemical characterization. Appropriate model systems were used in both in vivo and in vitro studies. Fluorescently labelled protein transiently expressed in tobacco leaves was used for localization studies and the same system was used to characterize the molecular properties of the protein. Phenotypes arising from overexpressing the PttMAP20 gene were traced in the model plant Arabidopsis. All the results obtained so far indicate that PttMAP20 is a novel microtubule associated protein that binds to a cellulose biosynthesis inhibitor, DCB (2,6-dichlorobenzonitrile) and is required during cellulose biosynthesis in secondary cell walls. / QC 20100906

Unknown bridge foundations pose a significant safety risk due to stream scour and erosion. Records from older structures may be non-existent, incomplete, or incorrect. Nondestructive and inexpensive geophysical methods have been identified as suitable to investigate unknown bridge foundations. The objective of the present study is to apply advanced 2D electrical resistivity imaging (ERI) in order to identify depth of unknown bridge foundations. A survey procedure is carried out in mixed terrain water and land environments with rough topography. A conventional resistivity survey procedure is used with the electrodes installed on the stream banks. However, some electrodes must be adapted for underwater use. Tests were conducted in one laboratory experimentation and at five field experimentations located at three roadway bridges, a geotechnical test site, and a railway bridge. The first experimentation was at the bridges with the smallest foundations, later working up in size to larger drilled shafts and spread footings. Both known to unknown foundations were investigated. The geotechnical test site is used as an experimental site for 2D and 3D ERI. The data acquisition is carried out along 2D profile with a linear array in the dipole-dipole configuration. The data collections have been carried out using electrodes deployed directly across smaller foundations. Electrodes are deployed in proximity to larger foundations to image them from the side. The 2D ERI can detect the presence of a bridge foundation but is unable to resolve its precise shape and depth. Increasing the spatial extent of the foundation permits better image of its shape and depth. Using electrode < 1 m to detect a slender foundation < 1 m in diameter is not feasible. The 2D ERI method that has been widely used for land surface surveys presently can be adapted effectively in water-covered environments. The method is the most appropriate geophysical method for determination of unknown bridge foundations. Fully 3D ERI method at bridge sites is labor intensive, time consuming, and does not add enough value over 2D ERI to make it worthwhile.

The aim of this study is to explore different graders¡¦ concept of unknown and performance in solving equations in concrete situations. In recent years of early algebra research in the United States (Carraher, Schliemann, & Schwartz, in press), it was found that through systematic teaching, low and middle graders¡¦ algebra performance was better than the same or even higher graders without teaching. Therefore, semi-structured interview was adopted to collect data on three cases: a second-grader, a fifth-grader and a seventh-grader who were using textbooks that follow Grade one-nine Integrated Coordinate Curriculum in SY89. The interview questions included addition and subtraction CHANGE problems, as well as multiplication and division EQUAL GROUPS problems; with natural numbers below 20, and given in four types: one-step, two-steps mixed, relating two unknowns and comparing two unknowns. Data analysis was conducted by referring to three sources of data: protocols from interviews, children¡¦s problem-solving records and interviewer¡¦s observation records. Research findings were: all three cases that received guidance could use equations to express problems; ¡§Undoing¡¨ was the most frequently used problem-solving strategy; both second and fifth graders could simplify expressions by number properties in concrete situations; both fifth and seventh graders could check if answers were reasonable; the meaning of equal sign developed from ¡§finding the results of¡¨ to ¡§equality in measures¡¨; and, individual differences in ¡§trial and error substitution¡¨ among three cases. Such results were consistent to that of Carraher. It is suggested that, introducing early algebra in the elementary school is helpful to children¡¦s learning of formal algebra in the junior high school.

Abstract The fundamental purpose of this research is to discuss the solution strategies and error types when seventh-grade students in middle school solved simple equations with one unknown and application problems; we hope results can provide reference for teachers in remedial teaching and in improving instructional. The items in the examination paper used in this research were taken from 12 past papers of basic competency test in Taiwan (2001 to 2006, twice a year). The subjects were students from Kaohsiung City Y Middle School (City region), Kaohsiung County T Middle School (Ordinary town) and Pingtung County Z Middle School (Near seacoast) forming a convenience sample. The investigators selected 2 classes from each school by random, with a total of 188 students. The main results of this research are as follows: 1. There are ten questions and the average proportion of correct answers is 49.10%; it shows that, at least 51% students have difficulties in solving symbolic operation and linear equations with one unknown. 2. The solution strategy student used most frequently is Removal of Term. Equal Axiom and Enumeration Evaluation Method were used occasionally. No student used Substitution method, Reduction method and Hidden method. 3. The main error types are: missing knowledge of using symbol; do not understand meanings of symbols; combine dissimilar terms freely; do not understand the meaning of bracket; cannot do calculation involving bracket; and, cannot simplify equation etc. 4. The main reasons for failures are: do not understand the meaning of equation; do not understand combination rules of like terms, position of symbol, unknown variables; whether containing fractions in reducing equation will also cause an error. Keywords: linear equations with one unknown, solution strategies, error types.

As of September 2007, there were over 67,000 U.S. bridges in the National Bridge Inventory classified as having unknown foundations. The bridges spanning rivers are of critical importance due to the risks of potential scour. In fact, over half of all bridge collapses are due to scour. Not only are these failures costly, they can be deadly for the traveling public. On April 5, 1987, ten people were killed in New York when a pier collapsed on the Schoharie Creek Bridge causing two spans of the deck to fall into the creek. Several other fatal collapses have occurred since the Schoharie Creek Bridge failure. Detecting scour is only part of the assessment that must take place to determine risk of failure and knowing the foundation depth is a critical component of the assessment. While this issue is not new, current techniques are typically invasive or costly. This research explores the feasibility and effectiveness of induced polarization (IP) and electrical resistivity imaging (ERI), near surface geophysical methods, for determining the depth of unknown foundations. In this work, forward models are created to ascertain the effects of the bridge layout on data quality such as varying depths and the impact of adjacent foundations on the foundation in question. Next, an experimental study is conducted at a National Geotechnical Experimentation Site (NGES) to further identify key parameters for the testing design and setup in order to obtain optimal surveys of bridge foundations. The conclusions of the forward modeling and NGES investigations are used to plan the field surveys on four bridges with known foundations. The outcomes of the four bridges show that IP and ERI can be used in concert with one another to estimate the type and depth of bridge foundations. The results of the field surveys are used to create a probability of non-exceedance curve for future predictions of unknown bridge foundations using the methods described in this research.

When examining the art, actions, and writings of Zurich Dadaists it becomes apparent that there is an affinity with Eastern thought, namely Taoism and Zen Buddhism. It cannot be said that Eastern thought directly influenced the artistic production of these Dadaists. However, the philosophy of Dada artists in Zurich mirrors that of Taoism and Zen so strongly that this connection cannot be ignored, although the Western art historical cannon has done just that. Exploring this connection offers a new perspective of Zurich Dada and encourages a reconsideration of the commonly applied label of nihilism to this group of Dadaists.

The aim of this study is to develop a methodology, through phenomenology, for exploring the unknown in the acquisition of therapeutic knowledge. An exploration is made of the way various writers attempt to explain the unknown, raising a problematic about how the unknown can become defined as if known, whereas others attempt to hold open the question of the unknown of the unknown. It is argued that learning places emphasis on knowing whereas in psychotherapy, there is increasing interest in learning to tolerate doubt and uncertainty. Ten participants were interviewed in terms of the question ‘how do psychotherapists learn about the unknown?’ An empirical phenomenological method was utilised to translate a general descriptive structure of the phenomenon. Findings suggest learning about the unknown as acquired during a process of lifelong enquiry through interrelated experiences, including: the known, training, therapy and supervision, practice and just living. Furthermore, immersion in experiences and relationships highlighted recognition of the spiritual or mystical, opening up hope in the face of fear of death and repeated disillusionment, with realisation that no single theory explains everything. In de-translating findings, examples of a second analysis suggested that reverie seemed more helpful in researcher and participants was disrupted, compared to empirical psychological phenomenology which separates phenomenology from philosophy. Reverie was explored as an approach, which can attend more to aspects where something other than dialectic of birth and death has possibility, and the unknown emerges when one disrupts the intentional position of the other.

Thesis (Ph. D.)--University of Toronto, 2004. / Adviser: Shahrzad Mojab. Includes bilbiographical references.

<p> The problem of communication would have been trivial if the channel through which the signal must propagate were ideal, that is, an all pass system with a linear phase response. In practice, channels are non-ideal; imperfections in the physical channel, such as time-dispersion and frequency-dispersion, are the results of signal dependent distortions. In addition, upon reception the signal is further corrupted by the inevitable presence of additive random noise. Time dispersion causes successive pulses to overlap, thereby creating a phenomenon which has been termed 'intersymbol interference'. Frequency dispersion causes the received signal spectrum to vary both in amplitude and phase. Unless these channel imperfections are taken into account in the design of the communication system, the rate of data transmission can be limited by the physical channel. Also, the presence of additive noise poses further limitations on the ultimate performance of the system.</p> <p> This thesis is concerned with adaptive signal processing techniques for digital communication through dispersive unknown channels. The research undertaken has been principally aimed at the analytical derivations of an adaptive recursive filter and an adaptive recursive equalizer, and the simulations of overall binary communication systems, taking into account dispersive effects as well as random noise.</p> <p> Computer simulation tests have indicated that the new adaptive equalizer exhibits a much more robust operation capability and improved system performance than the conventional adaptive equalizer. This study has indicated that adaptive signal processing is a viable technique upon which a reliable communications system may be designed.</p> / Thesis / Doctor of Philosophy (PhD)