Fault Localization Models in Debugging

Debugging is considered as a rigorous but important feature of software engineering process. Since more than a decade, the software engineering research community is exploring different techniques for removal of faults from programs but it is quite difficult to overcome all the faults of software programs. Thus, it is still remains as a real challenge for software debugging and maintenance community. In this paper, we briefly introduced software anomalies and faults classification and then explained different fault localization models using theory of diagnosis. Furthermore, we compared and contrasted between value based and dependencies based models in accordance with different real misbehaviours and presented some insight information for the debugging process. Moreover, we discussed the results of both models and manifested the shortcomings as well as advantages of these models in terms of debugging and maintenance.Comment: 58-6

Studies on length-weight and length-length relationships of a catfish Eutropiichthyes vacha Hamilton (Schilbeidae: Siluriformes) from Indus River, Sindh, Pakistan

Present study describes the length-weight (LWR) and length-length (LLR) relationships of a freshwater catfish Eutropiichthyes vacha Hamilton from Indus River, Sindh, Pakistan. A total of 281 specimen of E. vacha were collected from fisherman’s catch from February 2005 to January 2006, are used for this study. The parameters a and b of the length-weight relationship were calculated as W= aLb are presented. The values for allometric coefficient b of the LWR were close to isometric value for male (b = 3.159) and combined values for both sexes (b = 3.053). However, it suggested negative allometric growth for females (b = 2.973). Results for LLRs indicated that these are highly correlated (r2 > 0.9) P< 0.0001

Morphological pattern and frequency of thyroid tumors

Objective: The present study was done to evaluate the frequency of thyroid cancer and to find out the prevalence of histological types of thyroid tumor with respect to age and sex group.Setting: This study included consecutive cases of malignant tumors of thyroid gland, which were diagnosed in the Department of Pathology at the Aga Khan University Hospital, Karachi during the period of three years (1995-1997).Methods: These cases were evaluated on H & E stained sections from paraffin embedded 10% buffered formalin fixed tissue blocks. Special stains and immunohistochemical analysis were performed whenever required.Results: A total of 8541 malignant tumors were diagnosed in a period of 3 years which included 103 (1.2%) cases of thyroid cancer. Thyroid tumors were more prevalent in females with female to male ratio of 2.6:1. Papillary carcinoma (69%) was the most common histological type of thyroid tumors, followed by follicular carcinoma (11.6%), medullary carcinoma (9.7%), anaplastic carcinoma (5.9%), non-Hodgkin\u27s lymphoma (2.9%) and unclassified tumors (0.9%) in order of frequency.Conclusion: Thyroid cancer was more common in females. Papillary carcinoma was the most common histological type of thyroid tumors in females as well as in males. Papillary carcinoma was more prevalent in third, fourth and fifth decades of life while follicular and anaplastic carcinomas were more frequent after the fourth decade of life

Towards an understanding of Pakistani undergraduates’ current attitudes towards learning and speaking English

The English language has an important place in Pakistan and in its education system, not least because of the global status of English and its role in employment. Realising the need to enhance language learning outcomes, especially at the tertiary level, the Higher Education Commission (HEC) of Pakistan has put in place some important measures to improve the quality of English language teaching practice through its English Language Teaching Reforms (ELTR) project. However, there is a complex linguistic, educational and ethnic diversity in Pakistan and that diversity, alongside the historical and current role of English in the country, makes any language teaching reform particularly challenging. I argue, in this thesis, that reform to date has largely ignored the issues of learner readiness to learn and learner perceptions of the use of English. I argue that studying learner attitudes is important if we are to understand how learners perceive the practice of learning and the use of English in their lives. This study focuses on the attitudes of undergraduate learners of English as a foreign language at two universities in the provinces of Sindh and Balochistan in Pakistan. These provinces have experienced long struggles and movements related to linguistic and ethnic rights and both educate students from all of the districts of their respective provinces. Drawing on debates around linguistic imperialism, economic necessity, and linguistic and educational diversity, I focus on learners’ perceptions about learning and speaking English, asking what their attitudes are towards learning and speaking English with particular reference to socio-psychological factors at a given time and context, including perceived threats to their culture, religion, and mother tongue. I ask how they make choices about learning and speaking English in different domains of language use and question their motivation to learn and speak English. Additionally, I explore issues of anxiety with reference to their use of English. Following a predominantly qualitative mixed methods research approach, the study employs two research tools: an adapted Likert Scale questionnaire completed by 300 students and semi-structured interviews with 20 participants from the two universities. The data were analysed through descriptive statistics and qualitative content analysis, with each set of data synthesised for interpretation. The findings suggest that, compared with the past, the majority of participants hold positive attitudes towards learning and speaking English regardless of their ethnic or linguistic backgrounds. Most of these undergraduate students do not perceive the use of English as a threat to their culture, mother tongue or religious values but, instead, they have a pragmatic and, at the same time, aspirational attitude to the learning and use of English. I present these results and conclude this thesis with reference to ways in which this small-scale study contributes to a better understanding of learner attitudes and perceptions. Acknowledging the limitations of this study, I suggest ways in which the study, enhanced and extended by further research, might have implications for practice, theory and policy in English language teaching and learning in Pakistan

Clinico-morphological pattern of intracranial tumors in children

Objective: The objective of present study was to observe the histopathological pattern of intracranial tumors in children (\u3c 15 yrs) and to correlate the site of lesion along with the histological diagnosis. Setting: The study included consecutive cases of intracranial tumors diagnosed in children (\u3c 15 yrs.) in the section of histopathology at the Aga Khan University Hospital, Karachi during the period of three years. Methods:The initial histological evaluation of these lesions was performed on H and E stained section of paraffin embedded tissue. Special stains and immunohistochemical analysis was done whenever indicated. Results:During the study period, fifty-four cases of intracranial tumors were diagnosed in children. The age ranged from 1-1/2 years to 4 years with male to female ratio of 1.1:1. Astrocytoma comprised 39% of all intracranial tumors of childhood. Medulloblastoma (18.6%) ranked the second most prevalent brain tumor followed by empendymoma (13%), oligodendroglioma 7.5% while non-Hodgkin\u27s lymphoma, primitive neuroblastoma 3.7% and ganglioglioma 3.7% while non-Hodgkin\u27s lymphoma, primitive neuroectodermal tumors, mixed germ cell tumor, pineoblastoma, choroid plexus carcinoma and malignant meningioma constituted 1.8% each. Conculsion: Astrocytoma was the most common pediatric brain tumor. Medulloblastoma was more common in males while pilocytic astrocytoma was more frequent in females. Posterior cranial fossa was the most common site (43.5%) of pediatric brain tumors. Low grade astrocytoma was more prevalent in posterior cranial fossa as compared to high grade astrocytoma which was more frequent in the supratentorial region

Association of Epstein Barr Virus (EBV) with nasopharyngeal carcinoma (NPC)

Aim: To observe the frequency of nasopharyngeal carcinoma (NPC) and its association with Epstein Barr Virus (EBV) infection. Setting: This study included consecutive cases of nasopharyngeal carcinoma, which were diagnosed in the Department of Pathology at the Aga Khan University Hospital, Karachi in the period of two years (1996-97). Methods: These tumors were initially evaluated on H&E stained sections. The tumors showing evidence of keratinization were excluded from the study. The Epstein Barr Virus was detected with the help of Polymerase chain reaction in formalin fixed, paraffin embedded tissue sections. Results: During the study period, seventeen cases of nasopharyngeal carcinoma were diagnosed which comprised 0.3% of all malignant tumors. The age ranged from 5 years to 70 years with male to female ratio of 2.4:1. The NPC was more prevalent in adults (71%) as compared to children (29%) under 15 years. Six cases (35%) exhibited positive signal for Epstein Barr Virus. Conclusion: Nasopharyngeal carcinoma is an infrequent tumor. The prevalence of Epstein Barr virus infection in nasopharyngeal carcinoma is quite low as compared to other regions of the world

Clinico-morphological pattern and frequency of bone cancer

Objective: The present study was done to find out the frequency of malignant tumors of bone and to categorize the prevelence of various histological types of osseous malignancies with respect to age, sex and site of origin. Setting: This study included consecutive cases of malignant bone tumors, which were diagnosed in the department of pathology at the Aga Khan University Hospital, Karachi during the period of three years (1995-1997). Methods: These tumors were initially evaluated on H & E stained section from paraffin embedded tissue blocks. Special stains and immunohistochemical analysis was performed whenever required. Results: A total of 169 malignant bone tumors were diagnosed during the study period. Metastatic tumors accounted for 28.4% of all malignant tumors of bone. Osteogenic sarcoma (27.2%) was the most frequent primary tumor of bone followed by Ewing’s sarcoma (12.4%), Non- Hodgkin’s lymphoma (10.6%), Chondrosarcoma (8.3%), Plasma Cell Myeloma (8.3%) and other rare entities (4.8%) in order of frequency. Conclusion: The most common malignant neoplasm diagnosed in osseous biopsies was metastatic tumors. Osteogenic sarcoma was the most frequent primary bone tumor in this series. The bone tumors were relatively more prevalent in males. The frequency of malignant bone tumor was relatively high as compared to developed countries

Immunohistochemical evaluation of small round cell tumors of childhood

Objective: This study was done to evaluate the pediatric undifferentiated small round cell tumors with immunohistochemical staining. Setting: The present study included consecutive cases of small round cell tumors which were diagnosed in children (\u3c15 years) in the section of Histopathology at the Aga Khan University Hospital, Karachi during the period of two years. Methods: The group of undifferentiated small round cell tumors were evaluated immunohistochemically by using a panel of antibodies on sections from routinely processed, formalin fixed, paraffin embedded tissue blocks. Results: The category of undifferentiated small round cell tumors included rhabdomyosarcoma (23.2%), primitive neuroectodermal tumor (17.9%), non-Hodgkin’s lymphoma (16.1%), neuroblastoma (14.2%), Ewing’s sarcoma (10.7%) in order of frequency. Osteosarcoma (Small cell variant), retinoblastoma and medulloblastoma comprised 1.8% each. In seven cases (12.5%), the immunohistochemical analysis was inconclusive. Conclusion: Immunohistochemistry is a very valuable diagnostic tool which helps in distinguishing the undifferentiated tumors especially small round cell tumors. The immunohistochemical staining needs to be performed routinely for undifferentiated tumors in diagnostic histopathology