bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychological profiles of resilience in extreme environments: Correlating measures of personality and coping and resilience
Authors: Van Wijk Charles
Published: June 2022

The presence of psychological resilience appears to confer positive personal benefits, and may be particularly advantageous for individuals working in isolated, confined, and extreme environments. This study aimed to identify contextually adaptive ‘resilient’ personality and coping profiles in such contexts. This was done by correlating scores on measures of resilience with scores on measures of personality and coping, using specialists identified as good adaptors. As resilient profiles may differ across contexts, two highly specific samples were used, namely navy divers and submariners. This paper presents psychometric profiles of contemporary personality and coping styles. Then, using bivariate correlations, resilience-associated, context specific, diver and submariner personality and coping profiles were identified. Their resilient profiles appeared well suited to their respective environments. Some differences were noted between the typical personality descriptions and the resilient profiles identified, with three possible reasons forwarded to understand this. Firstly, there were some concerns regarding the validity of the measures in the local cultural context; secondly, context specific resilience may be expressed differently from resilience in general society; and thirdly, contemporary profiles of specialists may reflect current organisational processes in addition to psychological factors. In terms of practical application, while the identification of resilient profiles may also have value for selection purposes, it could be particularly useful for mission preparation, through the training of context-relevant coping skills.
Social media intelligence: The national security–privacy nexus
Authors: Putter Dries , Henrico Susan
Published: June 2022

Globally, changes in technology have always shaped the intelligence collection environment. South Africa is no different. The emergence of satellite imagery had a significant influence on the Geospatial Intelligence (GEOINT) capabilities and, similarly, the emergence of the telegram and later the telephone had and equally significant effect on the Signals Intelligence (SIGINT) environment. With communications being revolutionised by mobile technology that include recording, geo-positioning and photography, collection and distribution are ubiquitous. Smart mobile communication technology is also the driver of social media everywhere, at all ages, state, and non-state, non-stop. More recently, Social Media Intelligence (SOCMINT) has had the same significant influence on the collection of intelligence in general. Globally several examples of the successful exploitation of SOCMINT can be found internationally, it would be surprising if South Africa is not a statistic of this phenomenon yet. Initially, many organisations viewed (and some still do) SOCMINT as an Open-Source Intelligence (OSINT) tool. However, when considering the South African intelligence landscape, the concepts democracy, transparency, and intelligence oversight are calibrating factors to bear in mind. It is also important to consider the influence of the national legislative framework governing the use of SOCMINT in South Africa by state and non-state actors. It then becomes clear that issues such as personal legal right to privacy means that SOCMINT is probably no longer covered by the scope of the OSINT definition and that intelligence organisations collecting social media content and producing SOCMINT should adhere to the legislative framework governing the collection and use of social media content and the production of SOCMINT.
Breast-specific Gamma Imaging (BSGI) as a Complementary Imaging Tool for BI-RADS 0 and 4a Lesions on Mammography or Ultrasonography
Authors: Ryu Rae Rim , Kim Young Joong , Seo Jae Young , Kim Keum Won , Kim Jin Suk
Published: June 2022

Background: Mammography (MMG) and ultrasonography (US) have been used as standard imaging modalities for the diagnosis of breast cancer. However, several drawbacks have been attributed to these modalities. Breast-specific gamma imaging (BSGI), as a nuclear medicine imaging technique, has been introduced as a supplementary tool for diagnosing breast cancer. Objectives: This study aimed to determine whether the addition of BSGI to MMG or US interpretations could improve the diagnostic accuracy and reduce the need for further examinations or unnecessary biopsies of breast lesions. Patients and Methods: This retrospective study was conducted on 548 patients with 638 breast lesions from February 2013 to December 2018. The performance of BSGI, MMG, and US was examined for identifying breast cancer and high-risk lesions. Subgroups were classified by adding the results of BSGI for Breast Imaging-Reporting and Data System (BI-RADS) 0 and 4a lesions on MMG and BI-RADS 4a lesions on US. The diagnostic performance of each subgroup was then compared. The sensitivity, specificity, positive predictive value, and negative predictive value were also calculated. The diagnostic accuracy was determined by measuring the area under the receiver operating characteristic curve (AUC). Besides, factors associated with false-positive and false-negative results of BSGI were extracted. Results: The BSGI showed a sensitivity of 88.26% for breast cancer diagnosis, which was comparable to the sensitivity of MMG (87.95%) and lower than that of US (97.83%). The specificity and AUC of BSGI (81.62% and 0.85, respectively) were superior to those of MMG (66.83% and 0.77, respectively) and US (15.20% and 0.57, respectively). In the subgroup analysis of MMG, the sensitivity, positive predictive value, and AUC of MMG0+BSGI and MMG4a+BSGI increased significantly compared to MMG alone. In the MMG4a+BSGI group, the specificity also significantly increased. In the US subgroups, the specificity and AUC of US4a+BSGI increased significantly compared to US alone. Based on the results, a low Ki-67 index was associated with a false-negative result of BSGI. Conclusion: The addition of BSGI to MMG or US could improve the diagnostic performance, especially for BI-RADS 0 and 4a lesions. Additionally, the concomitant use of BSGI with MMG or US might reduce the need for an additional examination or unnecessary biopsy.
Framework for Assessing the Integration of Ethics in the Design of Impact Investment Ventures
Authors: Dedeke Adenekan ,   Philosophy Documentation Center
Published: June 2022

Impact investment ventures are growing in the modern economy. However, the recent failures of some impact investment ventures are a cause for concern. Unfortunately, our concern about the ethicality of these kinds of social exchanges seem to emerge when it is too late. Namely, we become concerned about lack of ethics when a venture has failed or is collapsing. A better approach would be for us to have a means to proactively assess and improve the degree to which the arrangements and practices of a social exchange meet ethical standards. Whereas much work has been done to equip social ventures to evaluate their impacts, little work has been done to create frameworks that could be used to assess the degree to which social exchanges integrate ethical practices in their designs. This paper proposes such a framework. For illustration purposes, the proposed framework would also be used to evaluate the One Acre Farm, an impact investment venture in Africa.
Language policy in Ghana and Malawi: differing approaches to multilingualism in education
Authors: Reilly Colin , ResCue Elvis , Chavula Jean Josephine
Published: June 2022

Despite substantial international evidence that children learn best in a language which they understand, language-in-education policies in much of Africa do not effectively accommodate the range of languages found in the classroom, instead prescribing dominant national languages and/or colonial languages such as English. Further, these language policies continue to reflect a monoglossic conceptualisation of languages and do not adequately account for the multilingual repertoires of individuals and communities. They do not reflect an understanding of the ways in which multilingual language practices could be harnessed for education. This article provides a comparative overview of the policy context in Malawi and Ghana, at the levels of legislation, practice, and attitudes. Through interviews, questionnaires, classroom observations, and classroom recordings in primary schools, we highlight the multilingual realities of educational spaces in each country. We highlight that, despite different sociolinguistic and legislative contexts, there are similarities between these contexts which emerge as important factors when considering multilingualism within education.
On the suitability of Swahili for early schooling in remote rural Tanzania: do policy and practice align?
Authors: Mapunda Gastor , Gibson Hannah
Published: June 2022

This article explores the use of Swahili for education in Tanzania, focusing on rural areas where Swahili is not the main language of the community. Current language policy mandates Swahili as the exclusive Medium of Instruction at primary level throughout the country. However, findings reported here show that in parts of rural Tanzania, children learn Swahili only after a substantial period of being at school, meaning that Swahili does not support early childhood education nor equality of outcomes. Children experience difficulties with progression in learning and teacher-dominated classes can be observed. The study also finds unequal performance in national examinations based on the language of the community, and a prevalence of grade repetition in some settings. It calls for a policy which appreciates the role of community languages and an approach which sees multilingualism as a resource to be harnessed both inside and outside the classroom.
Vulnerabilidade Turística: uma análise do fenômeno criminal contra turistas sob a perspectiva Durkheimiana
Authors: Tjäder Rodrigo Ciriaco
Published: June 2022

O viajante estrangeiro ou turista se apresenta em determinada sociedade como ser naturalmente vulnerável. A atividade socioeconômica denominada Turismo, que movimenta uma parcela considerável da economia mundial, atrai criminosos e modalidades de crime de toda sorte. Nesse sentido, o objetivo do presente estudo é demonstrar, por meio de estatísticas descritivas, como o fenômeno criminal é potencializado pela vulnerabilidade a que estão sujeitos os estrangeiros e turistas na cidade do Rio de Janeiro.
Dynamics of allosteric regulation of the phospholipase C-γ isozymes upon recruitment to membranes
Authors: Siraliev-Perez Edhriz , Stariha Jordan TB , Hoffmann Reece M , Temple Brenda RS , Zhang Qisheng , Hajicek Nicole , Jenkins Meredith L , Burke John E , Sondek John
Published: June 2022

Numerous receptor tyrosine kinases and immune receptors activate phospholipase C-γ (PLC-γ) isozymes at membranes to control diverse cellular processes including phagocytosis, migration, proliferation, and differentiation. The molecular details of this process are not well understood. Using hydrogen-deuterium exchange mass spectrometry, we show that PLC-γ1 is relatively inert to lipid vesicles that contain its substrate, phosphatidylinositol 4,5-bisphosphate (PIP2), unless first bound to the kinase domain of the fibroblast growth factor receptor (FGFR1). Exchange occurs throughout PLC-γ1 and is exaggerated in PLC-γ1 containing an oncogenic substitution (D1165H) that allosterically activates the lipase. These data support a model whereby initial complex formation shifts the conformational equilibrium of PLC-γ1 to favor activation. This receptor-induced priming of PLC-γ1 also explains the capacity of a kinase-inactive fragment of FGFR1 to modestly enhance the lipase activity of PLC-γ1 operating on lipid vesicles but not a soluble analog of PIP2 and highlights potential cooperativity between receptor engagement and membrane proximity. Priming is expected to be greatly enhanced for receptors embedded in membranes and nearly universal for the myriad of receptors and co-receptors that bind the PLC-γ isozymes.
Situating the ‘author’
Authors: Gough Brendan
Published: June 2022

… but some arresting, thought-provoking (seductive) phrases, images, gems:

‘concepts as light seductions’

‘seduction can lead to productive entanglements’

‘qualitative interviews as betrayal/abandonment/misrepresentation of the other’
The role of metacognition in promoting deep learning in MOOCs during COVID-19 pandemic
Authors: Elbyaly Marwa Yasien Helmy , Elfeky Abdellah Ibrahim Mohammed
Published: June 2022

In many nations affected by the COVID-19 pandemic, the situation in higher education institutions has changed. During the pandemic, these institutions have introduced numerous e-solutions to continue the process of education. Besides, research has shown many benefits in the last years of MOOCs. Yet, to date there are few studies to explore some individual characteristics, such as learners’ metacognitive skills, that might have an impact on learning outcomes in MOOCs. Furthermore, promotion of deep learning is a serious challenge for online courses including MOOCs. Therefore, the purpose of this research was to explore the role of metacognition in promoting deep learning in MOOCs during COVID-19 pandemic. The participants were students at the department of home economics who were all at the seventh academic level. Based on their scores on the metacognition awareness inventory (MAI), they were divided into two experimental groups,i.e.high metacognition students and low metacognition students. A three- aspect assessment card of deep learning namely connecting concepts, creating new concepts, and critical thinking was used to collect data. The results showed that MOOC was more effective in fostering the deep learning aspects of high metacognition skills, and deep learning as a whole. With regard to backward seeking and slow watching events, results showed significant differences in favor of high metacognition students (HMs). Nevertheless, there were no statistically significant differences between students in both groups regarding the pausing event.
Are all thermometers equal? A study of three infrared thermometers to detect fever in an African outpatient clinic
Authors: Ravi Nirmal , Vithyananthan Mathura , Saidu Aisha
Published: June 2022

Infrared thermometry has certain advantages over traditional oral thermometry including quick, non-invasive administration and an absence of required consumables. This study compared the performance of tympanic, temporal artery and forehead contactless thermometers with traditional oral electronic thermometer as the reference in measuring temperature in outpatients in a Nigerian secondary care hospital. A convenience sample of 100 male and 100 female adult patients (Mean age = 38.46 years, SD = 16.33 years) were recruited from a secondary care hospital in Kano, Nigeria. Temperature measurements were taken from each patient using the tympanic, temporal artery and contactless thermometers and oral electronic thermometer. Data was analyzed to assess bias and limits using scatterplots and Bland-Altman charts while sensitivity analysis was done using ROC curves. The tympanic and temporal artery thermometers systematically gave higher temperature readings compared to the oral electronic thermometer. The contactless thermometer gave lower readings compared to the oral electronic thermometer. The temporal artery thermometer had the highest sensitivity (88%) and specificity (88%) among the three infrared thermometers. The contactless thermometer showed a low sensitivity of 13% to detect fever greater than 38 °C. Our study shows that replacing oral thermometers with infrared thermometers must be done with caution despite the associated convenience and cost savings.
G.E.M Anscombe sobre la prioridad conceptual de una teoría de la acción intencional
Authors:   Universidad de Chile, Bussche Rivera Matias von dem
Published: June 2022

La presente investigación busca aclarar las razones fundamentales consideradas por G.E.M. Anscombe para defender la tesis según la cual el desarrollo de una teoría de la acción intencional es una tarea conceptualmente anterior a la de la ética o filosofía moral. La aclaración de dicho asunto opera en las siguientes etapas: 1) Es presentada la tesis anscombeana relativa a la anterioridad conceptual de la teoría de la acción respecto de la ética y es expuesto el material sistemático que permite hacerla inteligible. 2) Es interpretada la tesis de la anterioridad conceptual conforme al material sistemático expuesto y es, por ende, presentada la especificidad con que es introducida dicha tesis. 3) Se expone el modo en que la propia teoría de la acción de Anscombe es capaz de satisfacer la tarea que ella misma se ha puesto como una forma, también, de dar cuenta de la tesis de la anterioridad conceptual.
La impersonalidad en la traducción del italiano al español
Authors:   Universitat Autònoma de Barcelona (España), Edo Miquel
Published: June 2022

El italiano da muestras de una fuerte tendencia a la impersonalidad y, más en general, de una preferencia por las formas lingüísticas no personales, sean o no éstas funcionales a la expresión de una impersonalidad real. El español, en cambio, gusta de la marca de persona incluso en construcciones de sentido impersonal. El presente artículo analiza las distintas estructuras en las que se pone de manifiesto esta disimetría y los problemas que plantea en la traducción del italiano al castellano, así como los fenómenos de retórica contrastiva que se entrelazan con la misma.
Estudio de mercado de la traducción en Argentina, Chile y España: perfil académico y profesional de los traductores
Authors:   Pontificia Universidad Católica de Chile, Diéguez Morales María Isabel , Lazo Rodríguez Rosa María ,   Pontificia Universidad Católica de Chile, Quezada Gaponov Camilo ,   Pontificia Universidad Católica de Chile
Published: June 2022

El objetivo general de este estudio de mercado es conocer las principales características del trabajo que realizan traductores profesionales residentes en Chile, Argentina y España. Con este fin, se elaboró una encuesta en línea que permitió recabar información detallada sobre estas características, para luego describir contrastivamente los datos obtenidos por país. Además se realizó un estudio comparativo de los datos obtenidos en el estudio (2011) y una encuesta anterior (2008) aplicada a traductores residentes en Chile. La investigación tiene un enfoque cuantitativo y un alcance descriptivo. La encuesta fue respondida por 1077 traductores profesionales entre mayo y julio de 2011 y sus resultados permitieron actualizar y optimizar el Magíster en Traducción y el diploma de especialización en TIC aplicadas a la traducción que ofrece el Programa de Traducción de nuestra Universidad. Los datos obtenidos pueden ser también de utilidad para otras universidades que forman traductores profesionales. En este artículo se exponen algunos datos del estudio referidos a los perfiles académico yprofessional translation; profesional de los traductores que respondieron la encuesta.
La creación del modelo dialógico en el castellano del siglo XVI: interferencias entre las traducciones de los Coloquios de Erasmo
Authors:   Universidad de Tubinga (Alemania), Quesada Santiago del Rey
Published: June 2022

Este artículo se orienta a la descripción del modus interpretandi en diferentes traductores de los Colloquia erasmianos, obra fundamental para comprender la creación y el desarrollo del discurso dialógico a partir del Renacimiento en España. El análisis de los diferentes testimonios permite comprobar qué intérpretes realizan una versión más original, reflejo del texto latino, y qué otros siguen más de cerca traducciones preexistentes. El objetivo de este estudio es establecer el mapa de las mutuas influencias entre estas traducciones que representan un caso excepcional de la literatura de traducción en el Renacimiento, pues no son muchas las obras que, para el siglo XVI, cuentan con hasta cuatro traducciones diferentes, algo que pone en evidencia la influencia de los Coloquios en la vida cultural española de esta época
Ultrasonographic Measurement of Optic Nerve Sheath Diameter in Patients Undergoing Open Heart Surgery: A Prospective Cross-sectional Study
Authors: Vivek PD , Joshi VS , Kumar Anil , adhusudana HN M
Published: June 2022

Introduction: Adverse neurologic outcomes following cardiac surgery can be catastrophic to the patient, next of kin, healthcare facility and community at large. Ultrasonographic measurement of Optic Nerve Sheath Diameter (ONSD) has emerged as a promising modality to reflect Intracranial Pressure (ICP) and neurological status in various neurological settings. Aim: To explore ONSD as a tool to reflect ICP changes and predict neurologic outcomes in a cardiac surgical perioperative setting during Cardiopulmonary Bypass (CPB). Materials and Methods: This was an open-label, prospective and observational study conducted in Department of Anaesthesia, Command Hospital, Karnataka, India, from June 2016 to July 2018. All patients aged between 15 and 80 years who underwent open heart surgeries irrespective of gender, primary diagnosis and preoperative American society of Anaesthesiologist’s Physical Status (ASA PS) grade were enrolled in the study. Serial ultasonographic ONSD of both eyes in two planes (viz. sagittal and transverse) were acquired by a single observer at the following time intervals: baseline (prior to general anaesthesia induction, immediately postintubation, and every 15 minutes interval during CPB (until 150 minutes or end of the CPB whichever was earlier). Postoperative neurologic reassessment was done at 6 hours/postextubation (whichever earlier), at 24 hours and after 7 days, postoperatively. Continuous variables were compared using the student t-tests, while Chi-square or Fisher’sexact test was used to compare categorical variables. To assess inter-rater reliability for categorical variables, the Cohen’s Kappa statistic was used. Results: The mean age of the study cohort was 56.30±11.42 years. A slight male preponderance (56%) was observed. With regards to mean of total CPB time, it was insignificantly higher in patients with adverse neurologic outcomes as compared to those without adverse neurological outcomes (165.83±53.61 minutes vs. 121.36±21.41 minutes; p-value=0.098). Patients with adverse neurologic outcomes had significantly higher ONSD (average of both planes) on CPB from 60 minutes through 150 minutes/end of CPB timeline for right eye (p-value < 0.001), left eye (p-value <0.001), and both eyes (p-value <0.001). For patients with ONSD value (average of both eyes in both planes of each eye) ≥5.5 mm had more likelihood to develop adverse neurologic outcomes, postoperatively. With respect to maximum ONSD anytime during CPB (average of both eyes in both planes of each eye), an arbitrary cut-off of ≥5.5 mm showed a sensitivity of 100%, specificity of 95%, diagnostic accuracy of 100%, and predictive value of 100% with significant p-value of <0.001. Conclusion: Serial ultrasonographic ONSD measurement is assuredly a promising tool to monitor elevated level of ICP as well as a good predictor for the assessment of major adverse neurologic outcomes secondary to open heart cardiac surgeries.
Group B Streptococcal Colonisation among Pregnant Women Attending a Tertiary Care Hospital of Northeast India
Authors: Singh Amit Kumar , Beyong Taso , Agarwal Loveleena , Lundup Chuing , Bezbaruah Verbena
Published: June 2022

Introduction: Group B Streptococcus (GBS) is an important cause of maternal as well as neonatal morbidity and mortality worldwide. Early identification of colonisation of GBS among pregnant women plays an important role in preventing neonatal disease by taking measures such as antibiotic prophylaxis. In India, the spectrum of disease caused due to GBS is largely unrecognised due to lack of screening practices and also there is no specific guideline to prevent the disease. Aim: To determine the group B streptococcal colonisation and their antibiotic susceptibility profile among pregnant women of North-east India. Materials and Methods: The study was a hospital based cross- sectional survey conducted from April to June 2019. A total of 295 pregnant women with gestational age more than 35 weeks attending the Outpatient and Inpatient Departments were included in the study. Two vaginal swabs and two rectal swabs were collected from each participant and were processed according to standard laboratory protocol. Identification of GBS was done on the basis of Christie-Atkins-Munch-Peterson (CAMP) test and Lancefield grouping by latex agglutination test. Antibiotic susceptibility profile was also obtained for these isolates for certain antibiotics. Chi-square test was applied to determine the association of isolation among different types of cases. Results: Out of 295 pregnant women, 15(5.1%) showed GBS colonisation. There was no significant association found with age or socioeconomic status. However, GBS colonisation was found to be significantly associated with increasing gravidity (p-value=0.03). GBS colonisation of vaginal flora is siginficantly associated with rectal colonisation (p-value <0.01). Although certain isolates were found to be resistant to macrolide antibiotics (66.7%), all strains were uniformly sensitive (100%) to penicillin, levofloxacin, quinupristin-dalfopristin, vancomycin and linezolid. Conclusion: A low rate of colonisation was determined among the pregnant women and it is not associated with age and socioeconomic status. However, it is suggested that routine screening of pregnant women especially multigravida women should be done to prevent the transmission to the newborn.
Morphological and Anti-microbial Study of Whey Protein Concentrate Prepared by Dehydrating Milk Serum
Authors: Saurab Pal , Mishra Sunita
Published: June 2022

Whey protein concentrate (WPC) are an group of whey (Milk serum) based food ingredient. They are used in confectionary product, ready to eat cereals, nutritional bars,  and sports beverages.                                                                                                                                

Aim: The main aim of this study was to evaluate the morphological and antimicrobial study of whey protein concentrate after extraction from milk serum.                                    

Methods: Proximate analysis was done for the determination of protein, ash, fat, and moisture content in whey protein concentrate. Morphological study was done using X-Ray Diffraction (X-RD) and scanning electron microscope. The antimicrobial property of whey protein concentrate was evaluated by Agar well diffusion method.

Results: Proximate analysis reveals whey protein concentrates, protein (42%), Fat (4.40), ash (10.37), and moisture (4.27). The whey protein concentrate antimicrobial property also particularly effective against S. aureus (Gram Positive), E. coli (gram negative). SEM and X-RD results reveal micro structure and nature of the compound.
Expression of protein kinase C isozymes in hippocampal neurones in culture
Authors: Tejero-Díez Pedro , Rodríguez-Sánchez Paloma , Javier Díez-Guerra F.
Published: July 2002

Several protein kinase C (PKC) isozymes were analyzed by immunoblot and immunocytochemistry in cultures of hippocampal neurones at several stages of differentiation. Our findings reveal the existence of two distinct patterns of expression. Firstly, conventional PKC isozymes α, β and γ, that are expressed at very low levels during the initial stages and then increase continuously with time of culture. Secondly, novel PKC isozymes δ, ϵ and ζ, whose contents increase very early to reach a maximum after three days of culture and then progressively decline. Specific proteolysis for PKC isozymes β and γ was observed throughout the period studied. The developmental profile obtained for the different PKC isozymes is discussed in relation to the differentiation of hippocampal neurones in culture.
Preparative Purification of a Recombinant Protein by Hydrophobic Interaction Chromatography: Modulation of Selectivity by the Use of Chaotropic Additives
Authors: Shukla Abhinav A. , Peterson Joshua , Sorge Laura , Lewis Patsy , Thomas Shannon , Waugh Steve
Published: July 2002

Development and implementation of a chaotropic wash step following protein loading on a hydrophobic interaction chromatographic (HIC) column is described for the purification of a recombinant protein. Various agents that reduce protein affinity in hydrophobic interaction chromatographic systems were screened for their utility in a wash step following protein loading on a Phenyl Fast Flow Sepharose HIC column. A combination of sodium thiocyanate, glycerol, and urea was selected as a suitable additive for the wash buffer that selectively eluted most of the major impurities present in the feed stream. Eluate purity, as monitored by reversed‐phase chromatography and SDS‐PAGE, was significantly increased by incorporation of this wash step in the purification process. Incorporation of this wash step on HIC enabled a reduction in the overall number of chromatographic steps in the downstream purification process for this recombinant protein, resulting in improved process yields and significant economic advantages.The effect of varying concentrations of each of the three wash additives on yield was studied. While the step yield decreased with an increase in concentration for urea and sodium thiocyanate, an optimum was observed with respect to glycerol concentration. The preferential interaction theory is employed to explain this effect.
Effect of Additives on Refolding of a Denatured Protein
Authors: Yasuda Masahiro , Murakami Yumi , Sowa Ayumu , Ogino Hiroyasu , Ishikawa Haruo
Published: July 2002

Denatured lysozyme was refolded by a dilution method. The refolding yield depended greatly on the lysozyme concentration in the refolding mixture. When the concentration of denatured lysozyme was 0.02 g/L, the refolding yield was as high as 60%. However, when the concentration of denatured lysozyme was 0.2 g/L, the refolding yield was as low as 10% due to the formation of aggregates. To prevent the formation of aggregates and to increase the refolding yield at a low cost, inexpensive additives were screened. The addition of acetone, acetoamide, or urea derivatives was very effective for improving the refolding yield. To clarify why the addition of acetoamide in the refolding mixture improved the refolding yield at the high lysozyme concentration, the time courses of the concentration and the average diameter of the aggregates in the refolding mixture were monitored by the dynamic light scattering method. The experimental results showed that acetoamide played a role in preventing the formation and growth of aggregates and secondary aggregation between the lysozyme aggregates.
Production of Amylases from Rice by Solid‐State Fermentation in a Gas−Solid Spouted‐Bed Bioreactor
Authors: Silva Ellen M. , Yang Shang‐Tian
Published: July 2002

A gas−solid spouted‐bed bioreactor was developed to produce amylases from rice in solid‐state fermentation by Aspergillus oryzae. The spouted‐bed bioreactor was developed to overcome many of the problems inherent to large‐scale solid‐state fermentation, including mass‐ and heat‐transfer limitations in the conventional tray reactors and solids‐handling difficulties seen in packed‐bed bioreactors. The solid‐state fermentation results from the tray‐type reactor with surface aeration were poor because of mass‐ and heat‐transfer problems. A packed‐bed bioreactor with continuous aeration through the rice bed produced high protein and enzymes, but the fermented rice was difficult to remove and process due to the formation of large chunks of rice aggregates knitted together with fungal mycelia. Also, the fermentation was not uniform in the packed bed. The spouted‐bed bioreactor with intermittent spouting with air achieved high production levels in both total protein and enzymes (α‐amylase, β‐amylase, and glucoamylase) that were comparable to those found in the packed‐bed bioreactor, but without the nonuniformity and solids‐handling problems. However, continual spouting was found to be detrimental to this solid‐state fermentation, possibly because of shear or impact damage to fungal mycelia during spouting. Increasing spouting frequency from 4‐h intervals to 1‐h intervals decreased protein and enzyme production. Other operating conditions critical to the fermentation include proper humidification to prevent drying of the substrate and control of reactor wall temperature to prevent excessive condensation, which would interfere with proper spouting.
Characterization of recombinant glutathionylspermidine synthetase/amidase from Crithidia fasciculata
Authors: OZA Sandra L. , ARIYANAYAGAM Mark R. , FAIRLAMB Alan H.
Published: July 2002

Trypanothione [N1,N8-bis(glutathionyl)spermidine] is a unique metabolite found only in trypanosomatids, where it subsumes many of the functions of GSH in other organisms. In Crithidia fasciculata, two distinct ATP-dependent ligases, glutathionylspermidine synthetase (GspS; EC 6.3.1.8) and trypanothione synthetase (TryS; EC 6.3.1.9), are involved in the synthesis of trypanothione from GSH and spermidine. Both enzymes have been cloned previously, but expression in Escherichia coli produced insoluble and inactive protein. Here we report on the successful expression of soluble (His)6-tagged C. fasciculata GspS in E. coli. Following purification using nickel-chelating affinity chromatography, the tag sequence was removed and the enzyme purified to homogeneity by anion-exchange chromatography. The kinetic parameters of the recombinant enzyme have been determined using a coupled enzyme assay and also by HPLC analysis of end-product formation. Under optimal conditions (0.1M K+-Hepes, pH 7.3) GspS has synthetase activity with apparent Km values for GSH, spermidine and MgATP of 242, 59 and 114μM respectively, and a kcat of 15.5s−1. Glutathionylspermidine is formed as end product and the enzyme lacks TryS activity. Like E. coli GspS, the recombinant enzyme also possesses amidase activity (EC 3.5.1.78), hydrolysing glutathionylspermidine to GSH and spermidine with a kcat of 0.38s−1 and a Km of 500μM. GspS can also hydrolyse trypanothione at about 1.5% of the rate with glutathionylspermidine. A single amino acid mutation (Cys-79→Ala) is shown to ablate the amidase activity without affecting the synthetase activity.
Oreochromis mossambicus (tilapia) Corticotropin‐Releasing Hormone: cDNA Sequence and Bioactivity
Authors: Van Enckevort F. H. J. , Pepels P. P. L. M. , Leunissen J. A. M. , Martens G. J. M. , Wendelaar Bonga S. E. , Balm P. H. M.
Published: July 2002

Although hypothalamic corticotropin‐releasing hormone (CRH) is involved in the stress response in all vertebrate groups, only a limited number of studies on this neuroendocrine peptide deals with non‐mammalian neuroendocrine systems. We determined the cDNA sequence of the CRH precursor of the teleost Oreochromis mossambicus (tilapia) and studied the biological potency of the CRH peptide in a homologous teleost bioassay. Polymerase chain reaction (PCR) with degenerate and specific primers yielded fragments of tilapia CRH cDNA. Full‐length CRH cDNA (988 nucleotides) was obtained by screening a tilapia hypothalamus cDNA library with the tilapia CRH PCR products. The precursor sequence (167 amino acids) contains a signal peptide, the CRH peptide and a motif conserved among all vertebrate CRH precursors. Tilapia CRH (41 aa) displays between 63% and 80% amino acid sequence identity to CRH from other vertebrates, whereas the degree of identity to members of the urotensin I/urocortin lineage is considerably lower. In a phylogenetic tree, based on alignment of all full CRH peptide precursors presently known, the three teleost CRH precursors (tilapia; sockeye salmon, Oncorhynchus nerka; white sucker, Catostomus commersoni) form a monophyletic group distinct from amphibian and mammalian precursors. Despite the differences between the primary structures of tilapia and rat CRH, maximally effective concentrations of tilapia and rat CRH were equally potent in stimulating adrenocorticotropic hormone (ACTH) and α‐MSH release by tilapia pituitaries in vitro. The tilapia and salmon CRH sequences show that more variation exists between orthologous vertebrate CRH structures, and teleost CRHs in particular than previously recognized. Whether the structural differences reflect different mechanisms of action of this peptide in the stress response remains to be investigated.
Evaluation of Trichoderma harzianum for controlling root rot caused by Phytophthora capsici in pepper plants
Authors: Sid Ahmed A. , Pérez‐Sánchez C. , Egea C. , Candela M. E.
Published: July 2002

The ability of Trichoderma harzianum to control the rotting of pepper (Capsicum annuum) plant roots caused by Phytophthora capsici was studied. Interactions between the fungi were assessed in vitro on three culture media (V8c, Czapek and 2% water agar) and in vivo in plants grown in a substrate inoculated with P. capsici and T. harzianum. Studies on mutual antagonism in vitro showed that P. capsici was inhibited by T. harzianum; however, the intensity of inhibition differed according to the medium used, being greatest on Czapek. Analysis of the fungal populations in the plant growth substrate showed that T. harzianum consistently reduced that of P. capsici over time. This reduction in the pathogen population was associated with a reduction in root rot of between 24 and 76%, although plant growth (dry weight) was still reduced by 21.2–24.7%, compared with the uninoculated control. In the absence of T. harzianum with the same pathogen inoculum levels, the reduction in dry weight was 59.8–68.6%, suggesting that T. harzianum reduced the damage.
Comparison of In Vitro Maturation, In Vitro Fertilization, Metabolism and Ultrastructure of Oocytes from Prepubertal and Adult Pigs
Authors: O'Brien JK , Dwarte D , Ryan JP , Maxwell WMC , Evans G
Published: July 2002

Contents

In vitro maturation and fertilization, metabolism and ultrastructure were examined for oocytes from prepubertal and adult pigs. The proportion of oocytes undergoing in vitro maturation was lower for oocytes derived from prepubertal (piglets aged 8–10 weeks; 59.8% and gilts aged 5–6 months; 79.2%) than for those from adult ( ows aged 4–6 years; 92.2%) pigs (p < 0.05). A higher proportion of oocytes from piglets (22.8%) degenerated during in vitro maturation than from gilts (4.8%) and adult pigs (4.7%; p < 0.05). There was an increased incidence of polyspermic fertilization in prepubertal (piglet; 52.2%, gilt; 23.8%) compared with adult (7.1%) oocytes (p < 0.05). There were no differences in the metabolism of glucose, glutamine or pyruvate between oocytes from prepubertal and adult pigs. The metabolism of glutamine by prepubertal and adult oocytes matured in vitro was significantly higher than that by prepubertal oocytes matured in vivo (p < 0.05). Oocyte size and ultrastructure was also similar for oocytes from prepubertal and adult pigs. These data show that prepubertal and adult pig oocytes have a different in vitro developmental capacity, but similar metabolic activity and ultrastructure, under the conditions investigated.
Interpreting urgent brain CT scans: Does review by a radiology trainee make a difference in accuracy?
Authors: Heng Robert C , Bell Kevin W
Published: July 2002

An urgent brain CT scan is now commonly performed on patients presenting to hospital emergency departments for a wide variety of indications. At most institutions in Australia, such scans are reviewed immediately by an on‐call radiologist, who is usually an accredited registrar. The value of the trainee radiologist in such a setting is unclear. In the present study, the rate of abnormal findings in a random sample of 100 brain CT scans performed on hospital patients is reviewed and the accuracy of detection of potentially urgent lesions is compared between three junior clinicians, an accredited radiology registrar and a junior radiographer, using the final radiological report as the standard of reference. At least one potentially urgent abnormality in 25% of the patients scanned was found. The RANZCR trainee recorded a significantly higher sensitivity compared to the other readers. It is concluded that an urgent brain CT is of greater value as a screening test if a contemporaneous radiological review is made available, and the implications this may have on current imaging practices are briefly considered.
Effect of prolonged dissociation on the subjective measurement of near heterophoria
Authors: Rosenfield Mark , Chun Terry W. , Fischer Susan E.
Published: July 2002

Previous studies have demonstrated that vergence adaptation resulting from the prolonged decay of slow fusional vergence may prevent the accurate assessment of oculomotor deviations. Continuing changes in heterophoria have been reported after 27 days of monocular occlusion. However, since most slow fusional vergence will decay within the first ten minutes of dissociation, a clinical assessment of both vergence adaptation and heterophoria could be made more rapidly. This report documents two investigations which examined changes in near horizontal heterophoria during 30min and 180min of continuous dissociation, respectively. Seven out of the 16 subjects exhibited significant changes in heterophoria during the 30 min dissociation period, with a mean increase in exophoria of 3.4Δ. The decay of slow fusional vergence took approximately 25 min to reach completion. Thus in the clinical setting, both the degree of vergence adaptation and a more accurate assessment of heterophoria may be obtained by maintaining dissociation for 25 min. Furthermore, the presence of vergence adaptation can be assessed after just 5 min of dissociation.
Photochemical hole burning of tetraphenylporphin in phenoxy resin
Authors: Horie Kazuyuki , Mori Takeo , Naito Takuya , Mita Itaru
Published: July 2002

The efficiency of hole formation and the thermal stability of holes burnt at 4.2 K with 0.36 or 3.6 mW/cm2 helium-neon laser are studied for tetraphenylporphin (TPP) in phenoxy resin (aromatic polyhydroxyether, PhR) as well as in poly(methyl methacrylate) (PMMA). The efficiency of hole formation for TPP in PhR at 4.2 and 30 K is much higher than that in PMMA and the hole depth reaches more than 30% of initial absorbance. The purification by reprecipitation of the matrix polymer and the annealing of the sample films improve the efficiency. Our system of TPP in PhR is the first system in which the hole was detected even at liquid-nitrogen temperature (80 K) after 30 min annealing at the temperature. Partial recovery of the hole cooled again to 4.2 K was observed after holding the sample for 30 min at 120 K.
Resonant interband tunnel diodes
Authors: Sweeny Mark , Xu Jingming
Published: July 2002

Novel device structures are proposed, incorporating quantum wells and a pn diode structure. Such a device combines the structure and behavior of both resonant tunneling diodes and conventional tunnel diodes, leading to high speed and low excess current. There is interband tunneling between the conduction band and the valence band, as is in the case for a tunnel diode, but carriers are confined within quantum wells. Under small forward bias the diodes are expected to behave in a manner very similar to that of a tunnel diode formed of bulk material. Under large forward bias, however, the devices act much like resonant tunneling diodes, and display additional negative resistance regions.
Growth of regularly coiled spring-like fibers of Si3N4 by iron impurity-activated chemical vapor deposition
Authors: Motojima Seiji , Ueno Shuji , Hattori Tatsuhiko , Goto Keisuke
Published: July 2002

Very regularly coiled spring-like fibers of Si3N4 have been obtained from a gas mixture of Si2Cl6, NH3, and H2 at 1200 °C on a graphite substrate on which an iron impurity was painted. The spring-like fibers were amorphous Si3N4 with a circular cross section having a 0.5–1 μm thickness, 3–5 μm coil pitch, 10–15 μm coil diameter, and 50–100 μm coil length. The height of the bush of the fibers reached 1.5–2 mm after 30 min reaction time.
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u investigation of the optoelectronic properties of transparent conducting oxide/amorphous silicon interfaces
Authors: Drevillon B. , Kumar Satyendra , Roca i Cabarrocas P. , Siefert J. M.
Published: July 2002

Transparent conducting oxide (TCO)/hydrogenated amorphous silicon (a-Si:H) interfaces are investigated combining kinetic ellipsometry and Kelvin probe measurements. It is shown that the correlation between both in situ techniques allows a detailed description of the optoelectronic behavior of these interfaces. The Schottky barrier at the TCO/a/Si:H interfaces, as revealed by Kelvin probe measurements, is correlated with the chemical reduction of the TCO surface during the early stage of a:Si:H growth, as evidenced by kinetic ellipsometry. In particular, indium tin oxide (ITO) and SnO2 are found to be reduced by the silane plasma at 250 °C. On the countrary, ZnO is found highly resistant upon plasma reduction. The influence of the substrate temperature during a-Si:H deposition is analyzed. Finally, the technical consequences of this study are outlined.
Organic electroluminescent device having a hole conductor as an emitting layer
Authors: Adachi Chihaya , Tsutsui Tetsuo , Saito Shogo
Published: July 2002

We have succeeded in fabricating a novel thin-film electroluminescent device with a luminescent hole transport layer as an emitter. The cell structure is composed of an indium-tin-oxide substrate, a luminescent hole transport layer (emitter), an electron transport layer, and a MgAg electrode. The most essential feature of our device owes for adoption of an oxadiazole derivative as an electron transport layer. The emission intensity of 1000 cd/m2 was achieved at a current of 100 mA/cm2.
Resistivity of chemical vapor deposited diamond films
Authors: Landstrass M. I. , Ravi K. V.
Published: July 2002

Diamond films grown by plasma chemical vapor deposition techniques display a fairly low resistivity (∼106 Ω cm). Heat treating the films causes an increase in the resistivity by up to six orders of magnitude. The low resistivity of the as-grown films is postulated to be due to hydrogen passivation of traps in the films. Annealing causes dehydrogenation resulting in the electrical activation of deep traps with an attendant increase in the resistivity. This mechanism has been confirmed by an observed reduction of the resistivity of the heat-treated films when they are subjected to a plasma hydrogen treatment.
Conformal vapor phase epitaxy
Authors: Pribat D. , Karapiperis L. , Collet C.
Published: July 2002

A novel technique of shaped crystal growth from the vapor is presented, which we call conformal vapor phase epitaxy. Using selective epitaxy as a main ingredient, we have obtained a conformal Si single-crystal growth between two SiO2 films. Since vertical growth is physically impeded by a SiO2 cap, lateral to vertical growth ratios (overgrowth ratios) can be controlled at will. Using a standard chemical vapor deposition reactor, submicron thick (100)Si layers have been laterally grown with a totally controlled overgrowth ratio >20.
Magnetic force microscopy with 25 nm resolution
Authors: Hobbs Philip C. D. , Abraham David W. , Wickramasinghe H. K.
Published: July 2002

We describe a refined technique for magnetic force microscopy (MFM) which makes possible magnetic imaging with 25 nm resolution. Previous MFM work has relied on a servo system which used the amplitude of the response of an electropolished iron wire cantilever tip to an applied, near-resonance excitation to maintain a constant force gradient between tip and sample. The present results have been obtained with a redesigned instrument which uses a fast lock-in detector to servo on the phase, as opposed to the amplitude of the tip response. With these changes and the use of sharp electrochemically etched Ni tips, it is possible to servo stably on the very weak force gradients encountered in MFM, within 20 nm of the sample surface, and thus obtain 25 nm resolution.