bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of soil deformation modulus using the static and dynamic circular plate load test
Authors: Tašić Dušan , Đurđevac-Ignjatović Lidija , Ignjatović Dragan , Đurđevac Vanja , Softić Sead
Published: July 2022

The increase in mining activity in the Bor basin in recent years has also required the construction of new mining facilities. The construction of numerous embankments and dams, as parts of these facilities, required a constant control of compaction the coarse-grained and fine-grained materials from which they were built. The compaction check was performed using the static and dynamic circular plate test. The results of measurement and correlation of static and dynamic deformation modulus for multiple types of materials, used during construction, are presented.
Reconstruction of the northwestern slope of the open pit South Mining District Majdanpek for the purpose of reconstruction the active landslide
Authors: Kržanović Daniel , Rajković Radmilo , Vušović Nenad , Milutinović Sandra
Published: July 2022

The exploitation of copper ore in the Majdanpek Copper Mine takes place at the open pit South Mining District. The operation takes place in the complex conditions, and a special feature is that the capital infrastructure facilities: the state road M24, 35 kV transmission line and ri-verbed of the Mali Pek River are located in the northwestern contour of the open pit. Due to the occurrence of landslide in this part of the open pit, the continuity of the ore exploitation process in the mining system of excavation-processing was endangered, as well as the stability of infrastructure facilities. Reconstruction of the northwestern slope of the open pit will eliminate all existing and potential risks and create the conditions for functioning of the mine and town of Majdanpek.
Characterization of ground oscillations induced by underground mining
Authors: Kostić Srđan , Vasović Nebojša
Published: July 2022

We examine ground acceleration during M1.5 and M2.0 seismic events induced by underground mining at Upper Silesian coal basin and Legnica Glogow copper mine, respectively, using methods of nonlinear time series analysis, in order to confirm its stochastic nature. Recorded time series are firstly embedded into the adequate phase space using the mutual information and box-assisted methods. After this, we performed stationarity test, by which we confirmed that the examined ground acceleration belongs to a group of stationary processes. Surrogate data testing is applied then, which resulted in following: (1) horizontal ground acceleration at Legnica Glogow copper mine represents stationary linear stochastic processes with Gaussian inputs, (2) ground acceleration at Upper Silesian coal basin originates from a stationary Gaussian linear process that has been distorted by a monotonic, instantaneous, time-independent non-linear function, (3) vertical ground acceleration at Legnica Glogow copper mine could not be ascribed to any of the examined processes, probably due to high level of instrumental or background noise. Low values of determinism coefficient (c≤0.7), negative values of maximum Lyapunov exponent and quick saturation of neighboring points distance with the increase of embedding dimension indicate the absence of determinism in the observed ground acceleration time series.
El origen de ingresos del auditor y calidad de la auditoría: el caso español
Authors: Serrano-Madrid José , Bustos-Contell Elisabeth , Porcuna-Enguix Luis , Labatut-Serer Gregorio
Published: July 2022

Previous studies point out the existence of a relationship between auditor’s specialization and audit quality. Beginning with this idea, the more important the auditing activity is over the audit firm’s business and the greater specialization in such activity, the more conservative the signing auditor will be in the issuance of the audit report. Using the quantitative materiality as audit quality proxy, we examine the effect of consultancy services’ fees and the signing audit partners’ relevance on materiality values. From the hand-collected real amounts of quantitative materiality informed by 995 Spanish non-listed client-year sample, we conclude that more effort on consultancy services lead auditors to apply higher materiality numbers. Our results also show that audit firms employ higher materiality estimations when the signing audit partners gain importance within the audit firm, supporting the idea of a risky shift. Our findings are consistent with the mainstream that affirms there are other factors, beyond quantitative ones, that influence the determination of materiality amounts. This study contributes to the existing research by using archival data that mirrors auditors’ quantitative materiality judgements and its implication for financial reporting.

Estudios previos señalan la existencia de una relación entre la especialización del auditor y la calidad de la auditoría. A partir de esta idea, cuanto más importante sea la actividad de auditoría en el total del negocio de la firma auditora y mayor especialización exista en dicha actividad, el auditor firmante adoptará una postura más conservadora en la emisión de su informe. Utilizando la materialidad cuantitativa como subrogado de la calidad, se examina el efecto que los honorarios por otros servicios distintos a los de auditoría y el peso de los socios firmantes en la firma tienen sobre la cifra de materialidad. Partiendo de la materialidad real utilizada en cada uno de los encargos como medida de calidad de la auditoría y a través de una muestra de 995 clientes-año de compañías españolas no cotizadas, se concluye que una mayor dedicación a trabajos distintos a los de auditoría lleva al auditor a aplicar unas cifras de materialidad más altas. Los resultados también muestran que las firmas de auditoría usan materialidades más altas cuando los socios firmantes de la firma de auditoría ganan representación, reforzando la idea de un risky shift. Los hallazgos de este estudio son consistentes con la corriente de estudios que afirma que existen otros factores además de los cuantitativos que afectan a la fijación de la cifra de materialidad. Este trabajo contribuye a esta corriente mediante datos de archivo que reflejan el comportamiento del auditor durante la determinación de la cifra de materialidad cuantitativa y sus implicaciones en la divulgación de información financiera.
Pengaruh Tepung Beras Pragelatinisasi terhadap Penyerapan Minyak dan Sensori Kue Cucur
Authors: Savitri Putri Novita , Syamsir Elvira , Budijanto Slamet
Published: July 2022

Cucur is a traditional food with oily appearance,which may affect the sensory acceptance. Thus, in this research we attempted to reduce its oil absorption by using pregelatinized rice flour as the ingredient for cucur dough. The type of rice and temperature of extrusion process affect the characteristics of pregelatinized rice flour and final products. Thus, the objective of this research was to determine the effect of using pregelatinized rice flour on the oil uptake and sensory of cucur. The type of rice used were IR64 and IR42, and the extrusion process temperatures were 130 and 150°C. The oil uptake by cucur made with pregelatinized rice flour was analyzed during deep frying and sensory analysis was done on the resulting cucur. The results showed that the type of rice, temperature of extrusion, and their interactions had a significant effect on the characteristics and sensory of cucur. A combination of IR42 and 150°C resulted in cucur with 35.97% moisture content, 19.32% fat content, 18.14% moisture loss, 18.14% oil uptake, while the overall sensory attribute was acceptable to the panelists. Use of pregelatinized rice flour resulted in decrease in the oil uptake and moisture loss. Cucur made with pregelatinized rice flour has desirable intensities of sensory attributes (appearance, flavor, texture, and mouthfeel), which result in the higher overall preferences score.
DOES TOURISM INFLUENCE FINANCIAL DEVELOPMENT IN KENYA?
Authors: T. Musakwa Mercy , M. Odhiambo Nicholas , Nyasha Sheilla
Published: July 2022

Objective: In this study, we investigate the impact of tourism on financial development in Kenya using time series data from 1995 to 2017. The study uses the autoregressive distributed lag (ARDL) bound testing approach to cointegration and error correction model to examine this connection. To increase the robustness of the results, the study uses two proxies of financial development, namely broad money (bank-based financial development proxy) and total value of stocks traded (market-based financial development proxy). Results show that tourism has an insignificant impact on financial development in Kenya – both in the short run and in the long run. The results are relevant regardless of whether the financial development is proxied by a bank-based financial development indicator or by a market-based financial development indicator. This finding points to the fact that, although tourism is one of the main sources of foreign exchange in Kenya, it has no direct impact on financial development. The findings from this study add value to policy makers in Kenya by revealing the insignificant impact that tourism has on financial development, although this is in contrast to other studies that found a positive contribution. Based on the findings, Kenya may not anchor its financial development policies on tourism.
Effects of wind and rainfall on ambient noise in the East Indian Ocean
Authors: Liu Yun-Feng , Li Zheng-Lin , Qin Ji-Xing , Wu Shuang-Lin , Wang Meng-Yuan , Zhou Jiang-Tao ,   State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China,   School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China,   School of Ocean Engineering and Technology, Sun Yat-Sen University, Zhuhai 519000, China,   Mailbox 5111, Beijing 100094, China
Published: July 2022

The wind speed and rainfall rate above the sea surface have significant effects on the ocean ambient noise, and the noise level can be predicted by using the ocean ambient noise model combined with wind speed and rainfall rate parameters. In this work, we study the ambient noise characteristics in the East Indian Ocean and analyze the influences of wind speed and rainfall rate on the ocean ambient noise. The results show that the correlation coefficient between high-band noise level and wind speed could reach 0.59 in the absence of rainfall, that the correlation coefficient between high-band noise level and rainfall rate can reach 0.85 in the presence of rainfall, and that the strong rainfall can increase the high-band ambient noise level by more than 6 dB. The wind-generated noise source level formula is also modified to make it applicable to the deep-sea environment of the East Indian Ocean, and the overall error between the model prediction of noise intensity level and the experimental noise intensity level in intense rainfall is within 2 dB after the modification. When the model is validated by using small-scale rainfall noise data, it is found that the noise source model using a non-uniform rainfall noise source at the sea surface during small-scale rainfall is more accurate than using a uniform rainfall noise source. The modified prediction model of wind-generated and rain-generated noise is important for predicting the ocean-ambient-noise characteristics in the Indian Ocean.
Digital Youth Work in Flanders: practices, challenges, and the impact of COVID-19
Authors: Vermiere Lotte , Van den Broeck Wendy , Van Audenhove Leo , Mariën Ilse
Published: July 2022

The pandemic had a considerable impact on youth work in Flanders, as many face-to-face activities had to shift online out of necessity. For many youth organizations, this was their first encounter with digital youth work, either online or in a blended format. Despite this recent boom in digital youth work practices, the concept is not new. It was first mentioned in the 2017 conclusions on smart youth work[1] by the Council of the European Union. Digital youth work is defined as using and discussing digital media/technology in different types of youth work situations, whilst still adhering to the goals, values, and principles of general youth work (Council of the European Union, 2019). While some Flemish youth work organizations focused specifically on digital media before COVID-19, the pandemic has accelerated the uptake of digital youth work. This paper examines the effects of COVID-19 on youth work in Flanders. It explores the challenges and opportunities, using the quick-scan-method to map relevant organizations.

 

[1] “[I]mplementing smart youth work enables young people and youth workers to, based on existing experiences and seeking new connections and means, create innovative solutions (including digital solutions) for coping with both current problems and new challenges. Smart youth work activities are based on the needs of young people and youth workers, and take into account developments in society and technology, including globalisation, networking and e-solutions” (Schlümmer, 2018).
How Twitter data sampling biases U.S. voter behavior characterizations
Authors: Yang Kai-Cheng , Hui Pik-Mai , Menczer Filippo
Published: July 2022

Online social media are key platforms for the public to discuss political issues. As a result, researchers have used data from these platforms to analyze public opinions and forecast election results. The literature has shown that due to inauthentic actors such as malicious social bots and trolls, not every message is a genuine expression from a legitimate user. However, the prevalence of inauthentic activities in social data streams is still unclear, making it difficult to gauge biases of analyses based on such data. In this article, we aim to close this gap using Twitter data from the 2018 U.S. midterm elections. We propose an efficient and low-cost method to identify voters on Twitter and systematically compare their behaviors with different random samples of accounts. We find that some accounts flood the public data stream with political content, drowning the voice of the majority of voters. As a result, these hyperactive accounts are over-represented in volume samples. Hyperactive accounts are more likely to exhibit various suspicious behaviors and to share low-credibility information compared to likely voters. Our work provides insights into biased voter characterizations when using social media data to analyze political issues.
Genome-wide identification and functional analysis of class III peroxidases in Gossypium hirsutum
Authors: Chen Yi , Feng Jiajia , Qu Yunfang , Zhang Jinlong , Zhang Li , Liang Dong , Yang Yujie , Huang Jinling
Published: July 2022

Class III peroxidase (PRX) genes play essential roles in various processes, such as auxin catabolism, removal of H2O2, crosslinking cell wall components, and response to biotic and abiotic stresses. In this study, we identified 166, 78 and 89 PRX genes from G. hirsutum, G. arboretum and G. raimondii, respectively. These PRX genes were classified into seven subfamilies based on phylogenetic tree analysis and the classification of PRX genes in Arabidopsis. Segmental duplication and purifying selection were the major factors driving the evolution of GhPRXs. GO and KEGG enrichment analysis revealed that GhPRX genes were mainly associated with responding to oxidative stresses, peroxidase activities and phenylpropanoid biosynthesis pathways. Transcriptome data analysis showed that GhPRX genes expression were significantly different in microspore development between the sterility line-JinA and the maintainer line MB177. We confirmed the up-regulation of GhPRX107 and down-regulation of GhPRX128 in the sterile line compared to its maintainer line using qRT-PCR, suggesting their roles in pollen fertility. In addition, silencing GhPRX107 in cotton showed a significant decrease of the reactive oxygen species (ROS) levels of microsporocyte stage anthers compared to control. Overexpressing GhPRX107 in Arabidopsis significantly increased the ROS levels of anthers compared to wild type. In conclusion, we identified GhPRX107 as a determinant of ROS levels in anther. This work sets a foundation for PRX studies in pollen development.
Recent advances in methods for in situ root phenotyping
Authors: Li Anchang , Zhu Lingxiao , Xu Wenjun , Liu Liantao , Teng Guifa
Published: July 2022

Roots assist plants in absorbing water and nutrients from soil. Thus, they are vital to the survival of nearly all land plants, considering that plants cannot move to seek optimal environmental conditions. Crop species with optimal root system are essential for future food security and key to improving agricultural productivity and sustainability. Root systems can be improved and bred to acquire soil resources efficiently and effectively. This can also reduce adverse environmental impacts by decreasing the need for fertilization and fresh water. Therefore, there is a need to improve and breed crop cultivars with favorable root system. However, the lack of high-throughput root phenotyping tools for characterizing root traits in situ is a barrier to breeding for root system improvement. In recent years, many breakthroughs in the measurement and analysis of roots in a root system have been made. Here, we describe the major advances in root image acquisition and analysis technologies and summarize the advantages and disadvantages of each method. Furthermore, we look forward to the future development direction and trend of root phenotyping methods. This review aims to aid researchers in choosing a more appropriate method for improving the root system.
DEFICIÊNCIA VISUAL: PROPOSIÇÃO DE UM TESTE DE NIVELAMENTO AUXILIAR NO LEVANTAMENTO DE DEMANDAS FORMATIVAS DOCENTES
Authors: Venturini Medeiros Ronise , De Oliveira Pavão Sílvia Maria
Published: July 2022

Este trabalho teve como objetivo geral conhecer as principais demandas encontradas pelos professores da Educação Básica, para o desenvolvimento de práticas pedagógicas que efetivem a inclusão de alunos com deficiência visual no ensino regular, bem como apresentar um roteiro para teste de nivelamento. Apresenta caráter qualitativo, exploratório e descritivo. A análise dos dados foi realizada por meio da análise de conteúdo do tipo categorial. Constatou-se, que as principais demandas apontadas pelos participantes se referem a formação, a organização escolar/gestão, o pertencimento da Educação Especial, a inclusão escolar e a participação familiar. O roteiro de teste de nivelamento, foi elaborado a partir dos dados coletados e da análise de material bibliográfico na área da deficiência visual e possibilita conhecer as demandas dos docentes.
DARIO VELLOZO, ESCOLA MODERNA E O REGULAMENTO DE ENSINO DE 1909: OS EMBATES E DEBATES SOBRE A INSTRUÇÃO PÚBLICA NO PARANÁ
Authors: Ruckstadter Flávio Massami Martins , Mello Maria Beatriz De Almeida
Published: July 2022

O artigo analisa os debates e embates sobre a instrução pública no Paraná durante a primeira década do século XX. A pesquisa elegeu textos do intelectual Dario Vellozo, publicados no periódico A Escola, como suas principais fontes. Parte-se do pressuposto que os periódicos possibilitam amplas perspectivas de análise aos historiadores da educação. Neste caso, permitem analisar os projetos educacionais e societários em disputa no início do século passado. O referencial teórico e metodológico para análise foi pautado em Antonio Gramsci, em suas discussões acerca da função dos intelectuais na organização da cultura. Por meio da investigação foi possível identificar intensos e complexos debates intelectuais sobre a organização da instrução pública no período em questão.
Assessing the Strategies for Coping with Academic Stress among the Undergraduate Students of TNAU
Authors: Gayathri P. , Devi M. Nirmala , Balasubramaniam P. , Duraisamy M. R.
Published: July 2022

Aims: College students experience stress from many different sources that ultimately have an impact on their academics. To cope with the academic stress, it is needed for them to undertake appropriate coping strategies. This study aimed to identify the extent of various strategies used among the students to cope with the academic stress and to compare coping strategies used by the male and female students. 

Study Design: Ex post facto research design was used in this study.

Place and Duration of Study: Study area: Four Constituent colleges of Tamil Nadu Agricultural University viz., Coimbatore, Madurai, Trichy and Killikulam. Sample: Third-year B.Sc. (Hons.) Agriculture Undergraduate degree programme students. 

Methodology: Sample: 180 students (90 male and 90 female) from the four colleges were chosen based on employing proportionate random sampling. The coping strategies were classified into five categories namely relaxation, social support, personal, diet and exercise and psychological strategies The most preferred coping strategies were identified by computing mean scores and Mann Whitney U - test was employed to find the gender difference in terms of major stress coping strategies.

Results: The findings from the study showed that listening to music, seeking out friends for conversation, consulting with parents and relatives, using past experience to handle problems, getting enough sleep, look at the bright side of the things with mean scores of 2.48, 2.3, 2.29, 2.37, 1.99 and 2.35 respectively. There also existed a significant difference between male and female undergraduate students concerning relaxation and personal strategies at a 1% significance level.  

Conclusion: It could be concluded that the students should regularly be encouraged and motivated to get involved and take up better-suited and also scientifically approved coping strategies to handle and get relieved from their academic stress.
Effect of Iron Formulations on the Performance of Maize Crop
Authors: Malathi P. , Sellamuthu K. M.
Published: July 2022

Chelated iron formulations are gaining importance due to their higher use efficiency and favourable effect on crop growth and yield. At present, chelated iron formulations prepared using synthetic chelating agents are used by farmers which are harmful to the ecosystem. Hence, an attempt made in the present study to develop new chelated iron formulations using citric acid, a naturally occurring organic acid. Newly developed TNAU Fe citrate (10.9 % Fe) formulation was tested in comparison with Ferrous sulphate and commercial Ferric citrate. Nine treatments replicated thrice in Randomised Block Design (RBD). The treatments included control (NPK alone), soil application (basal) of FeSO4 @ 9.5 kg Fe ha-1, TNAU Fe citrate and commercial Ferric citrate @ 0.95 and 1.9 kg Fe ha-1, foliar spray of 1.0 % FeSO4, TNAU Fe citrate and commercial Ferric citrate thrice on 30, 40 and 50 days after sowing (DAS). The results revealed that foliar application of Fe fertilizers outperformed soil application due to the calcareous nature of the experimental soil. Among the Fe formulations, foliar spray of 1% TNAU Fe citrate recorded highest yield attributes (cob length, no. of grains /cob, 100 grain weight), grain and stover yield, net income and B:C ratio.
Maize Yield and Iron Uptake as Impacted by Iron Citrate Treatment
Authors: Malathi P. , Sellamuthu K. M.
Published: July 2022

Chelated iron formulations prepared using synthetic chelating agents are widely used and they are harmful to the environment. The present study was aimed at developing and evaluating new chelated iron citrate formulation. New chelated iron citrate formulation with 10.9% Fe was developed and evaluated in comparison with Ferrous sulphate and commercial Ferric citrate during 2018-19 in Tamil Nadu Agricultural University, Coimbatore. A field experiment was conducted with TNAU maize hybrid CO6. Nine treatments replicated thrice in Randomized Block Design.  The results revealed that foliar spray of 1% Tamil Nadu Agricultural University Fe citrate thrice on 30,40 and 50 days after sowing registered significantly highest grain yield (7065 kg ha-1) and stover yield (12583 kg ha-1). This was on par with foliar spray of 1% commercial Ferric citrate (T9). At late vegetative stage, significantly highest Fe content (268 mg kg-1) and Fe uptake (2.13 kg ha-1) were observed in foliar spray of 1% TNAU Fe citrate (T8). Significantly highest grain and stover Fe content (192 and 219 mg kg-1 respectively), grain and stover Fe uptake (1.28 and 2.58 kg ha-1 respectively) were observed with foliar spray of 1 % TNAU Fe citrate (T8).
Influence of Nutrient and Weed Management on Zn and S Uptake by Crop and weeds in Mustard
Authors: Tyagi Shashank , Kumar Arun , Paul S. C. , Acharya S. S.
Published: July 2022

A field experiment was conducted in rabi season 2018-2019 and 2019-2020 at Research farm of Bihar Agricultural College, Sabour to study the effect of nutrient levels and weed management on zinc and sulphur uptake by crop and weeds in mustard. This experiment consisted of three nutrient levels (N1-soil test-based recommended dose of fertilizer (RDF), N2-100 % RDF, N3-125 % RDF) in main plot; eight weed management practices (W1-Weedy, W2- Hand weeding (HW), W3-pendimethalin, W4-pendimethalin followed by (fb) quizalofop, W5-pendimethalin fb clodinafop, W6-oxyflourfen, W7-oxyflourfen fb quizalofop, W8-oxyflourfen fb clodinafop) in sub plots, was laid out in split plot design. Results indicated that in both the years 2018-19 and 2019-20, hand weeding at 25 and 50 DAS along with 125% RDF exhibited minimum Zn uptake by weeds. Among herbicides, application of pendimethalin 30 EC 1.0 kg a.i. ha-1 PE fb quizalofop 5 EC 60 g a.i. ha-1 PoE along with 125% RDF exhibited lowest Zn uptake by weeds. In both the years 2018-19 and 2019-20, hand weeding at 25 and 50 DAS along with 125% RDF recorded minimum S uptake by weeds. Lowest S uptake by weeds was noted under application of pendimethalin 30 EC 1.0 kg a.i. ha-1 PE fb quizalofop 5 EC 60 g a.i. ha-1 PoE along with 125% RDF. In 2018-2019, Zn uptake by mustard was maximum under 125% RDF being at par with soil test-based RDF and was superior over 100% RDF. Hand weeding at 25 and 50 DAS exhibited highest Zn uptake by mustard. Maximum Zn uptake by mustard was noted with pendimethalin 30 EC 1.0 kg a.i. ha-1 PE fb quizalofop 5 EC 60 g a.i. ha-1 PoE. In 2019-2020, hand weeding at 25 and 50 DAS along with 125% RDF exhibited highest Zn uptake by mustard. Among herbicides, application of pendimethalin 30 EC @ 1.0 kg a.i. ha-1 PE fb clodinafop 15 WP @ 60 g a.i. ha-1 PoE along with 125% RDF registered highest Zn uptake by mustard. In 2018-2019, hand weeding at 25 and 50 DAS exhibited highest S uptake by mustard. Maximum S uptake by mustard was recorded with pendimethalin 30 EC 1.0 kg a.i. ha-1 PE fb quizalofop 5 EC 60 g a.i. ha-1 PoE. In 2019-2020, although hand weeding at 25 and 50 DAS along with 125% RDF exhibited highest S uptake by mustard, however, pendimethalin 30 EC 1.0 kg a.i. ha-1 PE fb quizalofop 5 EC 60 g a.i. ha-1 PoE along with 125% RDF registered highest S uptake by mustard.
Teaching Analytical Instrumental Analysis to Undergraduates in Specialized Degree Programs with Heterogeneous Prior Knowledge: Reflections on Inquiry Based Lecture Activities
Authors:   Florida State University, Tucker Kirsten , Pingerelli Peter ,   Grand Canyon University
Published: July 2022

An adjunct faculty member and graduate instructional assistant (GIA) introduced inquiry-based activities into a 20-student undergraduate analytical instrumental analysis (AIA) lecture course, and reflect on their teaching assumptions, practices and experiences. The increased need for interdisciplinary scientific programs now has an AIA course serving multiple Bachelor of Science degrees in environmental sciences, forensic sciences, molecular biology, and secondary science education. However, we learned degree specialization also introduces into a course, student populations possessing heterogeneous prior knowledge, making an instructor’s rendering of student prerequisite skills a greater challenge. Guided by a pretest assessment, instructional activities were modified or developed by the authors and aimed at enhancing student engagement and motivation to mitigate prior knowledge gaps, improve analytical problem-solving skills, and facilitate a deeper understanding of modern instrumentation design and function. Detailed activity rationale and descriptions are presented. Activities included using readily available Internet bioinformatics and database tools for analytical problem-solving; demonstrating principles of electronic hardware and software design and integration; and creating interdisciplinary scientific narratives using biological, environmental, and industrial molecular exemplars. Our teaching reflections reference weekly post-lecture instructor/GIA discussions, strategic student questioning, collaborative classroom activity observations, and formative assessments. We propose continual instructional reflection is essential for a course serving multiple specialized degrees programs in a scientific field and facilitates preparation for students entering the workforce or graduate school. Further, our observations suggest inquiry-based, real-world activities relevant to modern instrumentation and its applications, assisted students in resolving heterogeneous prior knowledge gaps.
Epidermal growth factor induces serine phosphorylation of actin
Authors: van Delft Sanne , Verkleij Arie J. , Boonstra Johannes , van Bergen en Henegouwen Paul M.P.
Published: July 2002

Stimulation of cells by epidermal growth factor induces a rapid polymerisation of actin in the cortical skeleton. Activation of the EGF‐receptor leads to autophosphorylation and to phosphorylation of specific intracellular substrates. Here we show that actin is phosphorylated in vitro and in vivo upon EGF stimulation. Two‐dimensional phospho‐amino acid analysis shows that phosphorylation occurs on serine, not on tyrosine residues.
The 1,10‐phenanthroline micelles‐copper(I) complex catalyzes protein degradation
Authors: Kito Makoto , Takenaka Yasuyuki , Urade Reiko
Published: July 2002

The 1,10‐phenanthroline micelles‐copper(I) coordinated complex, not the mono‐dispersed bis 1,10‐phenanthroline‐copper(I) one, rapidly degraded proteins in the presence of β‐mercaptoethanol in the neutral‐to‐mild acidic region under aerobic conditions. The degradation products derived from α‐casein were peptides and amino acids.
Characterization of in vitro oxidized barstar
Authors: Frisch C. , Schreiber G. , Fersht A.R.
Published: July 2002

The polypeptide inhibitor of the ribonuclease barnase, barstar, has two cysteine residues in positions 40 and 82. These have been proposed to form a disulfide bridge leading to an increase in stability without changing the inhibitory activity of the protein. Barstar and a mutant (E80A) were oxidized in vitro and the biochemical and physico‐chemical properties of the oxidized monomers were analysed. The oxidized proteins show no inhibition of barnase using a plate assay and are significantly destabilized. CD spectra indicate a loss of secondary structure. The amino acid substitution E80 → A stabilizes the oxidized barstar to about the same extent as it does the reduced protein, indicating, however, that the helical region which it is in is intact.
The cytostatic activity of 5‐(1‐azidovinyl)‐2′‐deoxyuridine (AzVDU) against herpes simplex virus thymidine kinase gene‐transfected FM3A cells is due to inhibition of thymidylate synthase and enhanced by UV light (λ = 254 nm) exposure
Authors: Balzarini J. , Andrei G. , Kumar R. , Knaus E.E. , Wiebe L.I. , De Clercq E.
Published: July 2002

5‐(1‐Azidovinyl)‐2′‐deoxyuridine (AzVDU) and a series of 5‐[1‐azido‐2‐halogenoethyl]‐derivatives of β‐d‐arabinofuranosyluracil (AU) proved markedly inhibitory to the replication of herpes simplex virus type 1 (HSV‐1) and varicella zoster virus (VZV), but not thymidine kinase (TK)‐deficient HSV‐1 and VZV strains. None of the compounds were cytostatic. However, AzVDU, but not the 5‐[1‐azido‐2‐halogenoethyl]‐AU derivatives became highly cytostatic against HSV‐1 and HSV‐2 TK genetransfected FM3A tumor cells. The molecular target for the cytostatic effect of AzVDU proved to be thymidylate synthase. Short exposure of AzVDU‐treated FM3A TK−/HSV‐1 TK+ cells to irradiation at λ = 254 nm enhanced the cytostatic activity of AzVDU by 5‐fold.
Expression of an archaeal chaperonin in E. coli: formation of homo‐ (α, β) and hetero‐oligomeric (α + β) thermosome complexes
Authors: Waldmann Thomas , Nitsch Michael , Klumpp Martin , Baumeister Wolfgang
Published: July 2002

Co‐expression of the two genes encoding the α‐ and β‐subunit of the Thermoplasma acidophilum thermosome in Escherichia coli yielded fully assembled hetero‐oligomeric complexes (α + β). Surprisingly, also separate expression of both genes resulted in formation of hexadecameric complexes (α, β) in the bacterial cytoplasm. On electron micrographs these complexes were indistinguishable from each other and from the native thermosome. The recombinant a‐complex as well as the native thermosome could be reconstituted in vitro from their dissociated subunits in the presence of Mg‐ATP.
Current views on the management of trophoblastic tumors
Authors: Tham K.F. , Ratnam S.S.
Published: July 2002

Gestational trophoblastic disease has been recognized as a form of abnormal pregnancy as early as 1600 AD, and choriocarcinoma was the first cancer to be cured with chemotherapy even in the presence of distant and widespread metastases. Important advances in the past include the standardization of terminology, the concept of assignment of risk and the use of staging systems, the centralization of care and the establishment of regional registries, and of course the development of the radioimmunoassay for the beta subunit of human chorionic gonadotropin. The current views on the management of this disease recognizes the need for a multidisciplinary approach, with chemotherapy remaining at the forefront but also utilizing newer diagnostic techniques when necessary, and keeping in mind the crucial role that surgery can play especially in resistant cases. At the same time, the importance of basics such as careful follow up after evacuation of a hydatidiform mole cannot be overemphasized. There will be a continual refinement of the chemotherapy regimes used, and the aim is to achieve a similar level of response with decreased toxicity to the patient.
A simple cell labeling technique by means of lectins linked to fluorochromes for the detection of cells on tissue sections
Authors: Alonso‐Varona Ana , Calle Yolanda , Palomares Teodoro , Castro Begoña , Barberá‐Guillem Emilio
Published: July 2002

Summary— We designed a protocol for cell labeling with the lectin wheat germ agglutinin (WGA) linked to the fluorochrome tetramethyl‐rhodamine isothiocyanate (TRITC) for effective detection of the B16F10 melanoma and Lewis lung carcinoma (LLc) cells on pulmonary histological sections from C57BL6; mice. We have also determined a suitable concentration of WGA‐TRITC (10 μg/ml), which leads to a very intense and homogeneous labeling of the cells, as it avoids cell clumping due to the presence of the lectin WGA. In order to determine to what extent the method affects these tumor cells, we have studied some important aspects related to their metastatic behavior, taking into account three parameters: a) viability and rate of proliferation of the cells cultured in vitro; b) percentage of animals C57BL6 mice) bearing metastasis 15 days after intravenous inoculation with 105 B16F10 or LLc cells; and c) pattern of distribution of tumor foci in lung. There were no significant differences in these three parameters between the WGA‐TRITC labeled‐cells compared to the cultures of non‐labeled cells in either of the cell lines (B16F10, LLc). Thus, we conclude that B16F10 and LLc tumor cells can be labeled following the protocol set‐up in our study, as it allows these cells to be neatly identified on tissue sections and it causes no important physiological changes in the cells, with regard to metastatic behavior. These points make this technique very suitable for the detection of B16F10 and LLc cells on histological sections in studying their behavior during the first stages of the metastatic process.
The cytotoxic action of Bax on yeast cells does not require mitochondrial ADP/ATP carrier but may be related to its import to the mitochondria
Authors: Kiššová Ingrid , Polčic Peter , Kempná Petra , Zeman Igor , Šabová L'udmila , Kolarov Jordan
Published: July 2002

The effect of the expression of murine Bax protein on growth and vitality was examined in Saccharomyces cerevisiae and compared with the effect of Bax in mutant cells lacking functional mitochondria. The cytotoxic effect of Bax on yeast does not require functional oxidative phosphorylation, respiration, or mitochondrial proteins (ADP/ATP carriers) implicated in the formation of the permeability transition pore in mammalian mitochondria. In the wild type S. cerevisiae the expression of Bax does not result in a severe effect on mitochondrial membrane potential and respiration. On the basis of Bax induced differences in the fluorescence of green fluorescent protein fused to mitochondrial proteins, it is proposed that Bax may interfere with one essential cellular process in yeast: the mitochondrial protein import pathway that is specific for the proteins of the mitochondrial carrier family.
Properties of RNase A Immobilized on Magnetic Poly(2‐hydroxyethyl methacrylate) Microspheres
Authors: Horák Daniel , Rittich Bohuslav , Šafář Jan , Španová Alena , Lenfeld Jiří , Beneš Milan J.
Published: July 2002

Magnetic hydrogel microspheres 1.5 μm in size were prepared by dispersion copolymerization of 2‐hydroxyethyl methacrylate and ethylene dimethacrylate in the presence of magnetite, which formed the core of the particles. RNase A was coupled to the particles by the cyanuric chloride method. Gel electrophoresis of plasmid DNA pUC 19 (contaminated by bacterial RNA) confirmed RNA degradation with the immobilized enzyme. The effect of temperature and pH on the relative activity of immobilized RNase A was estimated after incubation of the samples at different temperatures (30−80 °C) and pH (4.0−8.0). Maximum relative activity was observed at 70 °C and pH 6.5. The matrices based on magnetic poly(HEMA) had a low tendency to adsorb RNA.
Separation of MBP Fusion Proteins through Affinity Membranes
Authors: Cattoli Francesca , Sarti Giulio C.
Published: July 2002

Cellulose microporous membranes have been modified in order to obtain a stationary phase specific for the recovery of a class of fusion proteins containing the maltose binding protein domain, through affinity chromatography separations. The feasibility of a single step separation process for the recovery of large amounts of the desired product has been considered. To that purpose, a preparative scale module has been realized, suitable for flat sheet membranes. The affinity matrix used proved to be highly selective toward the fusion proteins examined. The binding capacity determined is comparable with the nominal binding capacity of commercially available supports. The influence of the relevant working parameters, such as flow rate, on the performances of the recovery process has been studied.
Specific Effects of Synthetic Oligopeptides on Cultured Animal Cells
Authors: Franěk František , Katinger Hermann
Published: July 2002

Synthetic oligopeptides, tri‐ to pentaglycine and tri‐ and tetraalanine, were found to enhance viable cell density and culture viability when applied at concentrations higher than milllimolar to the cultures of a model hybridoma line. Oligoalanines, in addition, enhanced monoclonal antibody yields. Oligoglycines promoted solely the cell growth, unless the batch culture was fed with a medium concentrate. Examination of the effects of various tripeptides composed of glycine, alanine, serine, threonine, lysine, and histidine showed that some of the peptides promoted the growth of the culture, while other peptides suppressed the growth and enhanced the monoclonal antibody yield. Determination of the levels of amino acids and peptides in culture media indicated that the observed changes of culture parameters were caused by intact peptide molecules, rather than by amino acids liberated from the peptides by enzymic cleavage.
Use of Dye Affinity Chromatography for the Purification of Aerococcusviridans Lactate Oxidase
Authors: Streitenberger Sergio A. , López‐Más José A. , Sánchez‐Ferrer Álvaro , García‐Carmona Francisco
Published: July 2002

Lactate oxidase was purified from Aerococcus viridans ( A. viridans) by dye affinity chromatography and FPLC ion exchange chromatography. The lactate oxidase could be purified by comparatively simple procedures, the purification achieved from a crude extract of A. viridans was 41‐fold with a specific activity of 143 units/(mg of protein). The purified enzyme was a l ‐ lactate oxidase, which catalyses the conversion of l‐lactate in the presence of molecular oxygen to pyruvate and H2O2. This purified lactate oxidase showed an apparent molecular mass of 48 200 in SDS‐PAGE and the native molecular weight, as estimated by FPLC gel filtration, was 187 300. This molecular weight indicates that lactate oxidase exists in tetrameric form after gel filtration. To differing degrees, all the triazine dyes tested were inhibitors of lactate oxidase, solutions of free triazine dyes showing an inhibition mechanism which was both time‐ and pH‐dependent.
Thermal Denaturation of Lysozyme in a Cosolvent Studied by NMR
Authors: Hancock Timothy J. , Hsu James T.
Published: July 2002

The irreversible denaturation of hen egg white lysozyme was monitored by one‐dimensional1H nuclear magnetic resonance (1D1H NMR). Extended incubation of lysozyme at 75 and 81 °C in 20% w/w PEG 1000 caused more native lysozyme peak intensity loss than at 0% PEG. Further an increase in lysozyme concentration from 3.5 to 10 mM increased the irreversible denaturation as did the increase in temperature from 75 to 81 °C. Additionally, new peaks appeared in most spectra. Intriguingly, spectra in PEG after extended heating all resembled the reversible denatured state, whereas at 0% PEG spectra appeared native at reduced intensity, indicating that PEG causes the denatured state to persist, while without PEG, aggregation may persist. The methylenes and ethers of PEG may paralyze the denaturation and delay aggregation by hydrophobic and hydrogen bond interactions with the denatured state. The results indicate that NMR techniques may have many potential uses in biopharmaceutical industries. NMR may be able to provide further insight into product integrity, such as the extent of irreversible denaturation.
Structural features of thePip/AzPip couple in the crystalline state: influence of the relative AzPip location in an azadipeptide sequence upon the induced chirality and conformational characteristics
Authors: Didierjean C. , Aubry A. , Wyckaert F. , Boussard G.
Published: July 2002

Abstract: Azapipecolic (AzPip) is a pipecolic (Pip) residue analogue containing a nitrogen atom in place of the CαH group. AzPip was introduced into two reverse dipeptide sequences,Piv‐AzPip‐l‐Ala‐NHiPr I and Boc‐l‐Ala‐AzPip‐NHiPr II in order to evaluate, in the crystalline state, the influence of thel‐Ala‐induced chirality upon the prochiral AzPip residue, and therefore the resulting conformational characteristics, according to the relative position of the AzPip residue. Piv‐dl‐Pip‐NHMe III served as a control derivative for comparison between the properties of the two different heterocycles of Pip and AzPip residues. Piperidine and hexahydropyridazine rings have a few characteristics in common: chair conformation, axial disposition of the C‐terminal backbone substituent and the cisoid form of the N‐terminal tertiary amide function. An almost pure sp3 hybridization state is observed for the substituted nitrogen atom Nα, so that l‐Ala induces an AzPip (R) or (S) chirality when it follows or precedes, respectively, the azaresidue in such a pseudodipeptide sequence. If both I and II compounds present a short NH…N contact between the sp2 tertiary amide nitrogen atom and the NH of the next secondary amide function, whatever the chiral nature of the sequence, the heterochiral azadipeptide I adopts a rather totally extended conformation while the homochiral azadipeptide II is folded by a β‐VI turn‐like structure stabilized by a classical 4→1 intramolecular hydrogen bond.
Mutational analysis of the carbohydrate-binding activity of the NeuAc(α-2,6)Gal/GalNAc-specific type 2 ribosome-inactivating protein from elderberry (Sambucus nigra) fruits
Authors: CHEN Ying , ROUGE Pierre , PEUMANS Willy J. , van DAMME Els J.M.
Published: July 2002

Sambucus nigra agglutinin I (SNA-I) is a type 2 ribosome-inactivating protein. Site-directed mutagenesis was used to mimic the conversion of the highly active B-chain of fruit-specific SNA (SNA-If) into the completely inactive B-chain of the closely related and naturally occurring loss-of-activity mutant called S. nigra agglutinin lectin-related protein. In the first mutant SNA-If-M1 the high-affinity site 2 of SNA-If was disrupted by replacing the presumed critical residue Asp231 with Glu231. In the double mutant SNA-If-M2, site 1 of SNA-If-M1 was also disrupted by substituting the presumed critical residue Asn48 with Ser48. The parent type 2 ribosome-inactivating protein and both mutants were expressed in Nicotiana tabacum Samsun NN and the recombinant proteins were purified and analysed. Recombinant SNA-If agglutinated rabbit erythrocytes equally well as SNA-If, but both mutants were completely inactive in this test. Binding assays to immobilized galactose and fetuin revealed that the mutation Asp231→Glu231 reduces the affinity of the B-chain for galactose and fetuin by more than 50%. Furthermore, the introduction of the second mutation Asn48→Ser48 reduces the binding activity to less than 20% of the original activity.
Reduced susceptibility to apoptosis correlates with kinetic quiescence in disease progression of chronic lymphocytic leukaemia
Authors: Ricciardi Maria R. , Petrucci Maria T. , Gregorj Chiara , Ariola Cristina , Lemoli Roberto M. , Fogli Miram , Mauro Francesca R. , Cerretti Raffaella , Foà Robin , Mandelli Franco , Tafuri Agostino
Published: July 2002

The role of apoptosis and cell kinetics in the mechanisms of disease progression of chronic lymphocytic leukaemia (CLL) is still unclear. In the present study, we investigated the susceptibility of leukaemic cells taken from 75 CLL patients with either stable (STD) or progressive disease (PRD) to enter apoptosis. Particular attention was paid to the relationship between cell cycle status and autologous serum (AS). The susceptibility to enter apoptosis was significantly greater in STD than in PRD, both in standard medium (mean = 23·62% ± 14·7 versus 14·23% ± 7·2; P = 0·02) and in the presence of AS (mean = 23·03% ± 17·9 versus 11·27% ± 7·6; P = 0·01). Furthermore, cell kinetics studies revealed a higher quiescence in PRD than in STD cases, both in terms of a lower RNA content (P = 0·04) and of higher expression of the negative cell cycle regulator p27kip1 (P = 0·03). These kinetic differences were confirmed by short‐term in vitro culture both in fetal calf serum and in AS. The results of this study indicate that CLL cells from PRD cases are characterized by a higher degree quiescence and much lower susceptibility to apoptosis when compared with STD ones. In this context, AS does not appear to play a specific role. The association between these kinetic characteristics and disease progression in CLL prompts further studies to establish whether higher quiescence may be responsible for the decreased susceptibility of PRD cells to enter apoptosis.