42 research outputs found

    Using word frequency and parafoveal preview to determine the locus of contextual predictability and imageability effects: Evidence from eye movements during reading and lexical decision

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    The present thesis examines the time course of two semantic variables, contextual predictability and word imageability. Both variables can be said to reflect semantic aspects of meaning. For example the contextual predictability of a given target indicates the semantic context within which the target word occurs. The imageability of a given word reflects the meaning aspects of the word itself (Whaley, 1978). The word frequency effect (the faster response to commonly used high frequency words compared to low frequency words which occur less often) was taken to index the moment of lexical access (Balota, 1990; Pollatsek & Rayner, 1990; Sereno & Rayner, 2003) and by applying the logic of additive factors method (Sternberg, 1969a, 1969b), we determined whether the combined effect of each respective semantic variable was additive or interactive. This allowed us to examine whether there are semantic influences on lexical access. Previous research has been undecided and the question remains as to whether semantic variables operate during the lexical access processing stage, or alternatively after lexical access, for example in the post-lexical stage (e.g., Hand, Miellet, Sereno & Oā€™Donnell, 2010; Sereno, Oā€™Donnell & Rayner, 2006). Another aim of the thesis was to address the issue concerning the information presented to participants in the condition of ā€˜invalid parafoveal preview of a targetā€™ (e.g., Sereno & Rayner, 2000). Several criteria were identified as being important in order to make the assumption that parafoveal processing was successfully inhibited on the pre-target fixation. Another aim of the thesis was to investigate whether word frequency and contextual predictability of the parafoveal word affected parafoveal preview benefit. Preview benefit was calculated by subtracting fixation durations in a condition of ā€˜validā€™ preview of the target with an ā€˜invalidā€™ preview of the target. Experiment 1 utilised a lexical decision task to investigate the relationship between word frequency and the imageability of the word. Experiment 2 investigated whether the orthogonal manipulation of word frequency and contextual predictability led to an additive or interactive relationship between these two variables. Two pre-tests, the rating and Cloze tasks, were used to determine the predictability of the target. Experiment 3 and a further cross comparison of Experiments 2 and 3 replicated and extended Experiment 2 by additionally using an eye movement-contingent boundary change paradigm (Rayner, 1975). Experiment 4 examined the joint and combined effects of frequency, predictability and preview in a within-subjects design. A separate pre-test Cloze task was used to determine predictability of targets in their low and high predictable contexts. This experiment used a larger set of materials than in the previous experiments to examine these variables. Finally Chapter 6 was an overall discussion of the thesis. It was concluded that display screen presentations in our eye tracking experiments led to very fast reading times (as well as more skipping) compared to past studies which have used dot-matrix display presentations. It is possible that faster fixation durations led to floor effects in conditions where reading times are already fast because of preferential circumstances of high frequency targets, high predictable contexts and being given a parafoveal preview of the target. Possible ways to counteract this floor effect as well as alternative experimental methods of investigation were discussed

    Testing the limits of contextual constraint: interactions with word frequency and parafoveal preview during fluent reading

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    Contextual constraint is a key factor affecting a word's fixation duration and its likelihood of being fixated during reading. Previous research has generally demonstrated additive effects of predictability and frequency in fixation times. Studies examining the role of parafoveal preview have shown that greater preview benefit is obtained from more predictable and higher frequency words versus less predictable and lower frequency words. In two experiments, we investigated effects of target word predictability, frequency, and parafoveal preview. A 3 (Predictability: low, medium, high) Ɨ 2 (Frequency: low, high) design was used with Preview (valid, invalid) manipulated between experiments. With valid previews, we found main effects of Predictability and Frequency in both fixation time and probability measures, including an interaction in early fixation measures. With invalid preview, we again found main effects of Predictability and Frequency in fixation times, but no evidence of an interaction. Fixation probability showed a weak Predictability effect and Predictability-Frequency interaction. Predictability interacted with Preview in early fixation time and probability measures. Our findings suggest that high levels of contextual constraint exert an early influence during lexical processing in reading. Results are discussed in terms of models of language processing and eye movement control

    Early EEG correlates of word frequency and contextual predictability in reading

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    Previous research into written language comprehension has been equivocal as to whether word frequency and contextual predictability effects share an early time course of processing. Target word frequency (low, high) and its predictability from prior context (low, high) were manipulated across two-sentence passages. Context sentences were presented in full, followed by word-by-word presentation (300ā€…ms SOA) of target sentences. ERPs were analysed across left-to-right and anterior-to-posterior regions of interest within intervals from 50 to 550ā€…ms post-stimulus. The onset of significant predictability effects (50ā€“80ā€…ms) preceded that of frequency (P1, 80ā€“120ā€…ms), while both main effects were generally sustained through the N400 (350ā€“550ā€…ms). Critically, the frequency-predictability interaction became significant in the P1 and was sustained through the N400, although the specific configuration of effects differed across components. The pattern of findings supports an early, chronometric locus of contextual predictability in recognising words during reading

    Tukhm Khashkhaash (Poppy Seeds): A Unani drug of multitudinous potential

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    Tukhm Khashkhaash is the seeds of Papaver somniferum belonging to the family Papaveraceae. The description of Poppy seeds is mentioned in various classical Unani books. Renowned Unani scholar Avicenna had also described poppy seeds in his famous book ā€œThe Canon of Medicineā€. He wrote that Tukhme Khashkhaash safaid are the small white seeds obtained from the capsule of white poppy plant. The seeds which are obtained before the incision of capsules for the extraction of opium are considered to be of best quality. They are used since centuries for treating various ailments like diarrhea, dysentery, cough, premature ejaculation, chronic cough, insomnia and skin disorders as well as a nutritive food. Their antibacterial, anti-carcinogenic and hypoglycemic potential have also proved on scientific basis. In this review an effort have been made to collect the disseminated information and summarize the available data of the said drug

    Use Of Constructive Approach In Talk Shows: A Case Of Post Corona Raised Social, Economic And Religious Issues In Pakistan

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    Constructive approach in journalism emphasizes upon reporting of facts to provide solution oriented information. The use of constructive approach in the coverage of post corona social, economic and religious issues on Television talk shows was expected to inculcate positive thoughts among its viewers to overcome the feeling of fear and uncertainty. This study through content analysis, intends to check the use of constructive approach in television talk shows during the coverage of corona related social, economic and religious issues. For this purpose 114 programs of 5 popular TV talk shows on aired during lockdown period have been selected. Further, through purposive sampling, 33 programs with topic of social, economic and religious issues in the wake of Corona outbreak were scrutinized.           These programs were analyzed against constructive coverage index. The dimensions of index include introduction of the show, relevance of the invited guests, presence of different perspectives in discussion, role of anchor person and concluding part of the talk show. The findings reveal that certain ingredients of constructive journalism were missing in talk shows.&nbsp

    TRADITIONAL USES, PHYTOCHEMISTRY AND PHARMACOLOGICAL ACTIVITIES OF PAPAVER SOMNIFERUM WITH SPECIAL REFERENCE OF UNANI MEDICINE AN UPDATED REVIEW

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    Papaver somniferum commonly known as Khashkhash /Afyon, belongs to family Papaveraceae. It is one of those traditional plants, which have a long history of usage as medicine. The opium poppy (Papaver somniferum) produces some of the most widely used medicinal alkaloids like morphine, codeine, thebain and porphyroxine which are the most important component of this plant. Apart from these alkaloids, opium poppy produces approximately eighty alkaloids belonging to various tetrahydrobenzylisoquinolinederived classes. It has been known for over a century that morphinan alkaloids accumulate in the latex of opium poppy. According to Unani literature, it possesses most important theurapeutic values as modern literature and research studies also prove its therapeutical importance. It is used as analgesic, narcotic, sedative, stimulant as well as nutritive, etc. It is also useful in headache, cough, insomnia, cardiac asthma, and biliary colic. In this paper we have provide a review on habitate, pharmacological actions, phytochemical with special refrence to Unani Medicine. In this review, an attempt is made to explore the complete information of Papaver somniferum including its  phytochemistry and pharmacology. Key words: Khashkhash, Biliary colic, Alkaloid, phytochemistry

    Comparative analysis of chromogenic vs clot based CDC modified, Nijmegen-Bethesda assay for detection of factor viii inhibitor titre

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    Background:-Inhibitors to infused factor VIII are the most significant complication of hemophilia treatment. These inhibitors are usually IgG antibodies, that react with FVIII in a time and temperature dependent manner. Coagulation factor VIII inhibitors can be detected by Chromogenic, clot based and immunological assays. However, there is lack of consensus as to what constitutes a positive inhibitor, including the appropriate cut-off for inhibitor measurement The main objective of this study is to compare the sensitivity and specificity of chromogenic Nijmegen Bethesda assay (CNBA) with Centre for disease control modified Nijmegen Bethesda (CDC-NBA) assay against the Reference control method (RCM).Materials and Methods: The Coagulometer used for inhibitor titreĀ  quantification is Sysmex CS-5100. APTT reagent used isPathromtin SL supplied by seimensSeimens. All data were expressed as Mean Ā± SD. Statistical formulae were used for sensitivity and specificity calculations. Unpaired students t test was used whereever necessary and a P value of <0.05 is considered as statistical significanceResults: A total of 150 cases were tested for inhibitor titre using CNBA vs CDC-NBA. For low titre Inhibitor (<2 NBU), CNBA has 92% and 86% and CDC-NBA has 80 and 60% sensitivity and specificity respectively. These results show that CDC-NBA shows false positive results at low inhibitor titre. For High titre Inhibitor ( >2 NBU) CNBA has 88% and 80% and CDC-NBA has 85 and 70 % sensitivity and specificity respectively.Conclusion :- These results shows that CNBA is more sensitive and specific than CDC-NBA at both low and high inhibitor titre. Moreover chromogenic assays can differentiate factor specific inhibitor from nonspecific inhibitors like lupus anticoagulant and unfractionated heparin therapy.Keywords: Hemophilia, Bethesda assay, ELISA, Factor VIII, Inhibitor, Mixing studyAbbrevations: APLA- Antiphospholipid antibody syndrome, CDC:NBA- Centers for Disease Control and Prevention - Nijmegen-BethesdaAssay, CNBA:- chromogenic Nijmegen Bethesda assa

    Role of Serum Vitamin B12 and Glutathione Peroxidase during Third Trimester of Pregnancy with Gestational Diabetes Mellitus

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    Objective: To investigate the role and relationship of serum Vitamin B12 and Glutathione peroxidase in pregnancy with gestational diabetes mellitus (GDM). Study Design: Comparative cross-sectional study. Place and Duration of Study: Physiology Department, University of Health Sciences, Lahore Pakistan, from Feb 2019 to Mar 2020. Methodology: Ninty pregnant women were recruited, fulfilling the inclusion and exclusion criteria. Women with GDM were the cases, and those without GDM were the controls. Serum Vitamin B12 and Glutathione peroxidase were measured by ELISA. Results: Serum Vitamin B12 was significantly lower in cases compared to controls (158.98Ā±7.38 and 357.48Ā±42.07mg/dL, respectively, at p<0.001. Glutathione peroxidase was also significantly lower in cases compared to controls (2.68Ā±1.13U/mL and 5.53Ā±1.05U/mL, respectively, at p<0.001. Correlation analysis showed that Vitamin B12 and Glutathione peroxidase had a significant positive correlation in cases (p<0.001 and rho=0.76) and a non-significant correlation in controls (p=0.87 and rho=-0.024). Linear regression analysis showed that Vitamin B12 positively affects Glutathione peroxidase (Ī²=0.13, p<0.001).Vitamin B12 and Glutathione peroxidase have a significant, negative effect on fasting blood glucose (Ī² =-0.06, p<0.001 and Ī²=- 3.66, p<0.001, respectively). Conclusion: Deficient Vitamin B12 leads to reduced Glutathione levels in GDM pregnancy. A deficiency of these two predicts elevated blood sugar levels

    Anti-seizure activity of flower extracts of Nepeta bractaeta in Swiss albino mice

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    Epilepsy is a neurological disorder characterized by unprovoked, recurring seizures that disrupts the nervous system and can cause mental and physical dysfunction. Based on the ethno pharmacological information of the plant, the methanolic and aqueous extracts of the flowers of Nepeta bractaeta was evaluated for its antiepileptic activity. The methanolic and aqueous extracts of the flowers of Nepeta bracteata were observed for their antiepileptic activity by increased current Electroshock seizures (ICES) test and Pentylenetetrazole (PTZ) test using Swiss albino mice. Both the extracts showed significant activity in ICES and PTZ induced convulsions in comparison to control. In ICES model, NBAE at higher dose showed 16.7 % and NBME at higher dose showed 33.3 % protection against seizure and in PTZ model, NBME at higher dose showed 33.3 % protection against seizure. From the experiments performed, it can be said that Nepeta bractaeta does possess anticonvulsant property

    A concise overview of advancements in ultrasensitive biosensor development

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    Electrochemical biosensing has evolved as a diverse and potent method for detecting and analyzing biological entities ranging from tiny molecules to large macromolecules. Electrochemical biosensors are a desirable option in a variety of industries, including healthcare, environmental monitoring, and food safety, due to significant advancements in sensitivity, selectivity, and portability brought about by the integration of electrochemical techniques with nanomaterials, bio-recognition components, and microfluidics. In this review, we discussed the realm of electrochemical sensors, investigating and contrasting the diverse strategies that have been harnessed to push the boundaries of the limit of detection and achieve miniaturization. Furthermore, we assessed distinct electrochemical sensing methods employed in detection such as potentiometers, amperometers, conductometers, colorimeters, transistors, and electrical impedance spectroscopy to gauge their performance in various contexts. This article offers a panoramic view of strategies aimed at augmenting the limit of detection (LOD) of electrochemical sensors. The role of nanomaterials in shaping the capabilities of these sensors is examined in detail, accompanied by insights into the chemical modifications that enhance their functionality. Furthermore, our work not only offers a comprehensive strategic framework but also delineates the advanced methodologies employed in the development of electrochemical biosensors. This equips researchers with the knowledge required to develop more accurate and efficient detection technologies
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