bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of antibody induction upon immunization with distinct NTS-DBL1α-domains of PfEMP1 from rosetting Plasmodium falciparum parasites
Authors: Angeletti Davide , Albrecht Letusa , Wahlgren Mats , Moll Kirsten
Published: January 2013

Background

Rosette-formation of Plasmodium falciparum parasitized erythrocytes is of importance in the development of severe malaria. The parasite-derived molecule PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1), central to rosetting, is suggested to be included in a multimeric vaccine targeting severe disease.

Methods

Three recombinant NTS-DBL1α-domains of PfEMP1 were generated in Escherichia coli, purified and used for immunization of rats and goats. Antibody titres were determined in ELISA assays and responses were compared in-between different individual animals and species. Reactivity with the parasites was tested in live pRBC using FACS. B-cell epitopes prediction was carried out in silico and compared to the results obtained by peptide microarray. Screening for serological cross-reactivity with heterologous NTS-DBL1α variants was carried out by ELISA, peptide array and FACS on pRBC of different laboratory strains and patient isolates.

Results

All three NTS-DBL1α-domains induced high titres of antibodies that were biologically active with no apparent difference between constructs covering slightly different parts of the DBL1α-sequence. The different animal species showed comparable titres of antibodies, while variations within individuals of the species could be observed.

Mapping of the recognized epitopes revealed that most parts of the molecule were able to induce an antibody response with a tendency for the N and C terminal parts of the molecule for slightly higher recognition. Important differences to the epitopes predicted were found as some of the most conserved parts of the DBL1α-domain contained the main epitopes for antibody reactivity. ELISA assays and peptide microarray demonstrated substantial cross-reactivity to heterologous variants, while binding to native PfEMP1 was observed only in few combinations on the pRBC surface, underlining that mainly internal, conserved and not surface exposed parts of the DBL1α-domain are responsible for this observation.

Conclusion

Biologically active antibodies can be induced consistently, with high titres, in different animal species and the antibodies elicited by different constructs react with similar epitopes. Induced antibodies recognize epitopes localized in all subdomains of the DBL1α-sequence. Cross-reactivity between NTS-DBL1α-variants is common in ELISA, but rare with live pRBC emphasizing that also internal, conserved areas of PfEMP1 carry important highly immunogenic epitopes of the molecule.
Management of patients with chronic cough using a clinical protocol: a prospective observational study
Authors: Ojoo Josephine C , Everett Caroline F , Mulrennan Siobhain A , Faruqi Shoaib , Kastelik Jack A , Morice Alyn H
Published: January 2013

Background and aims

Chronic cough is a common symptom the aetiology of which can be challenging to diagnose. Diagnostic protocols for chronic cough have required the use of specialist investigations which are not always easily available. We wanted to determine whether patients with chronic cough can be successfully managed using a clinical algorithm.

Methods

112 consecutive patients with chronic cough were prospectively recruited into this study. They were assessed by history, physical examination, chest radiograph, spirometry and reversibility to nebulised salbutamol. A clinical diagnosis was made and the patient had an 8-week trial of appropriate therapy. Further therapeutic trials were carried out depending on response to treatment and the possible differential diagnoses. Investigations were carried out in cases of failed clinical trials and to exclude specific pathology. The “clinical arm” comprised patients managed on the basis of clinical assessment and without any investigations. The “investigative arm” comprised those who needed further investigations.

Results

81 (72%) were managed in the clinical arm. Of these 74 (66%) were discharged following response to therapy. 31 (28%) patients were converted to the investigative arm after failure of diagnosis in the clinical protocol. The commonest causes of cough were gastroesophageal reflux, asthma and chronic rhinitis. 51 (45.5%) patients responded to therapy based on diagnosis at initial assessment while a further 23 (20.5%) patients responded to sequential clinical trials for the commonest causes of cough. Cough severity score improved by a mean of 3.6 points on a numeric response score (from 0–10, p < 0.0001).

Conclusion

It is possible to manage a majority of chronic cough patients successfully using a protocol based on presenting symptoms and therapeutic trials for the common causes of cough.
Laboratory capacity for diagnosis of foot-and-mouth disease in Eastern Africa: implications for the progressive control pathway
Authors: Namatovu Alice , Wekesa Sabenzia Nabalayo , Tjørnehøj Kirsten , Dhikusooka Moses Tefula , Muwanika Vincent B , Siegsmund Hans Redlef , Ayebazibwe Chrisostom
Published: January 2013

Background

Accurate diagnosis is pertinent to any disease control programme. If Eastern Africa is to work towards control of foot-and-mouth disease (FMD) using the Progressive Control Pathway for FMD (PCP-FMD) as a tool, then the capacity of national reference laboratories (NRLs) mandated to diagnose FMD should match this task. This study assessed the laboratory capacity of 14 NRLs of the Eastern Africa Region Laboratory Network member countries using a semi-structured questionnaire and retrospective data from the World Reference Laboratory for FMD annual reports and Genbank® through National Centre for Biotechnology Information for the period 2006–2010.

Results

The questionnaire response rate was 13/14 (93%). Twelve out of the 13 countries/regions had experienced at least one outbreak in the relevant five year period. Only two countries (Ethiopia and Kenya) had laboratories at biosecurity level 3 and only three (Ethiopia, Kenya and Sudan) had identified FMD virus serotypes for all reported outbreaks. Based on their own country/region assessment, 12/13 of these countries /regions were below stage 3 of the PCP-FMD. Quarantine (77%) and vaccination (54%) were the major FMD control strategies employed. The majority (12/13) of the NRLs used serological techniques to diagnose FMD, seven used antigen ELISA and three of these (25%) also used molecular techniques which were the tests most frequently requested from collaborating laboratories by the majority (69%) of the NRLs. Only 4/13 (31%) participated in proficiency testing for FMD. Four (31%) laboratories had no quality management systems (QMS) in place and where QMS existed it was still deficient, thus, none of the laboratories had achieved accreditation for FMD diagnosis.

Conclusions

This study indicates that FMD diagnostic capacity in Eastern Africa is still inadequate and largely depends on antigen and antibody ELISAs techniques undertaken by the NRLs. Hence, for the region to progress on the PCP-FMD, there is need to: implement regional control measures, improve the serological diagnostic test performance and laboratory capacity of the NRLs (including training of personnel as well as upgrading of equipment and methods, especially strengthening the molecular diagnostic capacity), and to establish a regional reference laboratory to enforce QMS and characterization of FMD virus containing samples.
pH induced reversible assembly of DNA wrapped carbon nanotubes
Authors: Wan Ying , Liu Gang , Zhu Xinhua , Su Yan
Published: January 2013

Background

Reversible assembly and disassembly of nanostructures has important function in controllable construction of nanodevices. There are several methods to achieve reversible assembly/disassembly, such as pH, temperature, DNA hybridization and so on. Among these methods, pH driven reversible assembly presents superiority due to its ease-of-use and no waste produced. Herein we report a novel design that use two single-stranded (ss) DNAs wrapped single walled carbon nanotubes (SWCNTs) for the pH controlled assembly of SWCNTs without generation of waste.

Results

Both of the two DNAs with a same wrapping sequence of d(GT)20 and different free terminals showed a very high tendency to wrap around carbon nanotubes. The assembly was driven by the hybridization between the two free terminals of wrapped DNAs on the neighboring SWCNTs: i-motif (four-stranded C-quadruplex) and its complemental stranded G-quadruplex which would form tight tetraplexes and break the hybridization under slightly acidic conditions. Thus the assembly and disassembly are reversibly controlled by pH. And this assembly/disassembly process can be easily distinguished by naked eyes. Gel electrophoresis and Atomic Force Microscope are used to demonstrate the assembly and disassembly of SWCNTs at different pH.

Conclusions

A novel pH induced reversible assembly and disassembly of SWCNTs was realized which may have potential applications in the area of controlled assembly of nanostructures.
The signalling factor PI3K is a specific regulator of the clathrin-independent dynamin-dependent endocytosis of IL-2 receptors
Authors: Basquin Cyril , Malardé Valérie , Mellor Paul , Anderson Deborah H. , Meas-Yedid Vannary , Olivo-Marin Jean-Christophe , Dautry-Varsat Alice , Sauvonnet Nathalie
Published: January 2013

Receptor-mediated endocytosis is an essential process used by eukaryotic cells to internalise many molecules. Several clathrin-independent endocytic routes exist, but the molecular mechanism of each pathway remains to be uncovered. The present study focuses on a clathrin-independent dynamin-dependent pathway used by interleukin 2 receptors (IL-2R), essential players of the immune response. Ras-related C3 botulinum toxin substrate (Rac1) and its targets, the p21-activated kinases (Pak), are specific regulators of this pathway, acting on cortactin and actin polymerization. The present study reveals a dual and specific role of phosphatidylinositol 3-kinase (PI3K) in IL-2R endocytosis. Inhibition of the catalytic activity of PI3K strongly affects IL-2R endocytosis, in contrast to transferrin (Tf) uptake, a marker of the clathrin-mediated pathway. Moreover, Vav2, a GTPase exchange factor (GEF) induced upon PI3K activation, is specifically involved in IL-2R entry. The second action of PI3K is through its regulatory subunit, p85α, which binds to and recruits Rac1 during IL-2R internalisation. Indeed, the overexpression of a p85α mutant missing the Rac1 binding motif leads to the specific inhibition of IL-2R endocytosis. The inhibitory effect of this p85α mutant could be rescued by the overexpression of either Rac1 or the active form of Pak, indicating that p85α acts upstream of the Rac1-Pak cascade. Finally, biochemical and fluorescent microscopy techniques reveal an interaction between p85α, Rac1 and IL-2R that is enhanced by IL-2. In summary, our results indicate a key role of class I PI3K in IL-2R endocytosis that creates a link with IL-2 signalling.
COUP-TFII orchestrates venous and lymphatic endothelial identity by homo- or hetero-dimerisation with PROX1
Authors: Aranguren Xabier L. , Beerens Manu , Coppiello Giulia , Wiese Cornelia , Vandersmissen Ine , Lo Nigro Antonio , Verfaillie Catherine M. , Gessler Manfred , Luttun Aernout
Published: January 2013

Endothelial cell (EC) identity is in part genetically predetermined. Transcription factor NR2F2 (also known as chicken ovalbumin upstream promoter transcription factor II, COUP-TFII) plays a key role in EC fate decision making; however, many of the underlying mechanisms remain enigmatic. In the present study, we demonstrate that NR2F2 differentially regulates gene expression of venous versus lymphatic ECs (LECs) and document a novel paradigm whereby NR2F2 homodimers induce a venous EC fate, while heterodimers with the LEC-specific transcription factor PROX1 instruct LEC lineage specification. NR2F2 homodimers inhibit arterial differentiation in venous ECs through direct binding to the promoter regions of the Notch target genes HEY1 and HEY2 (HEY1/2), whereas NR2F2/PROX1 heterodimers lack this inhibitory effect, resulting at least in part in non-canonical HEY1/2 expression in LECs. Furthermore, NR2F2/PROX1 heterodimers actively induce or are permissive for the expression of a major subset of LEC-specific genes. In addition to NR2F2/PROX1 heterodimerisation, the expression of HEY1 and some of these LEC-specific genes is dependent on PROX1 DNA binding. Thus, NR2F2 homodimers in venous ECs and NR2F2/PROX1 heterodimers in LECs differentially regulate EC subtype-specific genes and pathways, most prominently the Notch target genes HEY1/2. This novel mechanistic insight could pave the way for new therapeutic interventions for vascular-bed-specific disorders.
Using multifocal plane microscopy to reveal novel trafficking processes in the recycling pathway
Authors: Gan Zhuo , Ram Sripad , Ober Raimund J. , Ward E. Sally
Published: January 2013

A major outstanding issue in cell biology is the lack of understanding of the contribution of tubulovesicular transport carriers (TCs) to intracellular trafficking pathways within 3D cellular environments. This is primarily due to the challenges associated with the use of microscopy techniques to track these highly motile, small compartments. In the present study we have used multifocal plane microscopy with localized photoactivation to overcome these limitations. Using this approach, we have characterized individual components constituting the recycling pathway of the receptor FcRn. Specifically, several different pathways followed by TCs that intersect with larger, relatively static sorting endosomes have been defined. These pathways include a novel ‘looping’ process in which TCs leave and return to the same sorting endosome. Significantly, TCs with different itineraries can be identified by associations with distinct complements of Rab GTPases, APPL1 and SNX4. These studies provide a framework for further analyses of the recycling pathway.
Long-Term Impacts of Individual Development Accounts on Homeownership among Baseline Renters: Follow-Up Evidence from a Randomized Experiment
Authors: Grinstein-Weiss Michal , Sherraden Michael , Gale William G , Rohe William M , Schreiner Mark , Key Clinton
Published: January 2013

We examine the long-term effects of a 1998–2003 randomized experiment in Tulsa, Oklahoma with Individual Development Accounts that offered low-income households 2:1 matching funds for housing down payments. Prior work shows that, among households who rented in 1998, homeownership rates increased more through 2003 in the treatment group than for controls. We show that control group renters caught up rapidly with the treatment group after the experiment ended. As of 2009, the program had an economically small and statistically insignificant effect on homeownership rates, the number of years respondents owned homes, home equity, and foreclosure activity among baseline renters. (JEL D14, H75, R21, R31)
The Demand for Food of Poor Urban Mexican Households: Understanding Policy Impacts Using Structural Models
Authors: Angelucci Manuela , Attanasio Orazio
Published: January 2013

We use Oportunidades, a conditional cash transfer to women, to show that standard demand models do not represent the sample's behavior: Oportunidades increases eligible households' food budget shares, despite food being a necessity; demand for food and high-protein food changes over time only in treatment areas; the treatment effects on food and high-protein food consumption are larger than the prediction from the Engel curves at baseline; and the curves do not change in eligible households with high baseline bargaining power for the transfer recipient. Thus, handing transfers to women is a likely determinant of the observed nutritional changes. (JEL D12, H23, J16, O12)
Targeting with Agents
Authors: Niehaus Paul , Atanassova Antonia , Bertrand Marianne , Mullainathan Sendhil
Published: January 2013

Targeting assistance to the poor is a central problem in development. We study the problem of designing a proxy means test when the implementing agent is corruptible. Conditioning on more poverty indicators may worsen targeting in this environment because of a novel tradeoff between statistical accuracy and enforceability. We then test necessary conditions for this tradeoff using data on Below Poverty Line card allocation in India. Less eligible households pay larger bribes and are less likely to obtain cards, but widespread rule violations yield a de facto allocation much less progressive than the de jure one. Enforceability appears to matter. (JEL D12, I32, I38, O12, O15)
The Price Effects of a Large Merger of Manufacturers: A Case Study of Maytag-Whirlpool
Authors: Ashenfelter Orley C , Hosken Daniel S , Weinberg Matthew C
Published: January 2013

Many experts speculate that US antitrust policy towards horizontal mergers has been too lenient. We estimate the price effects of Whirlpool's acquisition of Maytag to provide new evidence on this debate. We compare price changes in appliance markets most affected by the merger to markets where concentration changed much less or not at all. We estimate price increases for dishwashers and relatively large price increases for clothes dryers, but no price effects for refrigerators or clothes washers. The combined firm's market share fell across all four affected categories, and the number of distinct appliance products offered for sale fell. (JEL G34, K21, L11, L41, L68)
Unemployment in an Interdependent World
Authors: Felbermayr Gabriel J , Larch Mario , Lechthaler Wolfgang
Published: January 2013

How do changes in labor market institutions, like more generous unemployment benefits in one country, affect labor market outcomes in other countries? We set up a two-country Armingtonian trade model with frictions on the goods and labor markets. Contrary to the literature, higher labor market frictions increase unemployment at home and abroad. The strength of the spillover depends on the relative size of countries and on trade costs. It is exacerbated when real wages are rigid. Using panel data for 20 rich OECD countries, and controlling for institutions as well as for business cycle comovement, we confirm our theoretical predictions. (JEL E24, F16, J64, J65)
Poisoning: Fact or Fiction?
Authors: Flanagan Robert J.
Published: January 2013

Analytical toxicology is a complex discipline. Simply detecting a poison in a biological sample does not necessarily mean that the individual from whom the sample was obtained had been poisoned. An analysis can prove exposure and perhaps give an indication of the magnitude of exposure, but the results have to be placed in proper context. Even if sampling was antemortem an analysis does not necessarily prove the effects that the drug or poison had on the victim immediately before or at the time of sampling. Tolerance is one big issue, the mechanism of exposure (how the drug got into the body) is another, and of course with postmortem work there are always additional considerations such as site of sample collection and the possibility of postmortem change in analyte concentration. There are also questions of quality and reliability, and whether a particular analysis and the interpretation placed upon the result are appropriate in a particular case.
Media Multiplexing Behavior: Implications for Targeting and Media Planning
Authors: Lin Chen , Venkataraman Sriram , Jap Sandy D.
Published: January 2013

There is a growing trend among consumers to serially consume small, incomplete “chunks” of multiple media types—television, radio, Internet, and print—within a short time period. We refer to this behavior as media multiplexing and note that key challenges for integrated marketing communications media planners are (1) predicting which media or combination of media their target audience is likely to consume at any given time and (2) understanding potential substitutions and complementarities in their joint consumption. We propose a forecasting model that incorporates media-multiplexing behavior of both traditional and new media, their interdependencies, and consumer heterogeneity, and we calibrate the model using a rich database of individual-specific media activity diaries. The results suggest that accounting for media synergies within a single utility specification significantly improves model forecasts. We also introduce a utility function that directly models cross-channel media complementarities via interactive effects of the satiation parameters of own and joint consumption of various media types. Finally, our individual-level analyses generate unique insights on consumer-level media switching, multiplexing, and individual heterogeneity often ignored in aggregate data.
Vaporware, Suddenware, and Trueware: New Product Preannouncements Under Market Uncertainty
Authors: Ofek Elie , Turut Özge
Published: January 2013

A firm may want to preannounce its plans to develop a new product in order to stimulate future demand. But given that such communications can affect rivals' incentives to develop the same new product, a firm may decide to preannounce untruthfully in order to deter competitors. We examine an incumbent's preannouncement strategy when there is uncertainty regarding the commercial viability of a new product opportunity and a threat of rival entry. Each firm has a private assessment of the market potential for the new product. Two competitive incentives arise for the incumbent in terms of discouraging rival entry: it can use preemptive communication or it can remain silent and instill a pessimistic market potential outlook. We find that an incumbent prefers to follow a vaporware strategy—i.e., declares plans to pursue a new product opportunity even when it may have no development intentions—when its market forecasting capabilities are weak and the demand-side benefits from preannouncing are small. By contrast, when the incumbent has strong market forecasting capabilities and the demand-side benefits are small, the incumbent adopts a suddenware strategy—i.e., remains silent about its new product plans even when it actually plans to develop the new product. Finally, when its market forecasting capabilities are strong and the demand-side benefits are large, the incumbent prefers to engage in a trueware strategy—i.e., truthfully preannounces development plans. We show that an interplay between competition-related and demand-related considerations is what allows trueware to emerge as an equilibrium in the absence of any ex post cost to engaging in vaporware. In an extension, we let the incumbent's actual development plans leak out and allow the entrant to wait and learn those plans prior to setting a research and development level. We identify conditions for the entrant to postpone development despite the risk of being late to market, as well as conditions for the entrant to commence development immediately despite not knowing the incumbent's plans based on the observed preannouncement strategy.
Multilateral Bargaining and Downstream Competition
Authors: Guo Liang , Iyer Ganesh
Published: January 2013

We examine multilateral bargaining in vertical supply relationships that involve an upstream manufacturer who sells through two competing retailers. In these relationships the negotiations are interdependent, and bargaining externality may arise across the retailers. In addition, the timing by which the manufacturer negotiates with the retailers becomes important. In simultaneous bargaining the retailers negotiate without knowing if an agreement has been reached in the other retail channel, whereas in sequential bargaining the retailer in the second negotiation is able to observe whether an agreement was reached in the first negotiation. We show that simultaneous bargaining is optimal for the manufacturer when the retail prices (and profitability) are similar, and sequential bargaining is preferred when the dispersion in the retail prices is sufficiently large. As a result of ex post renegotiations, the manufacturer may strategically stock out the less profitable retailer who charged a relatively low retail price and exclusively supply only the retailer who charged a relatively high retail price and maintained high channel profitability. Moreover, ex post multilateral bargaining can buffer downstream competition and thus lead to positive retail profits even in markets that are close to perfect competition.
The Role of MET Receptor Tyrosine Kinase in Non-Small Cell Lung Cancer and Clinical Development of Targeted Anti-MET Agents
Authors: Robinson Kyle W. , Sandler Alan B.
Published: January 2013

A better understanding of the pathophysiology and evolution of non-small cell lung cancer (NSCLC) has identified a number of molecular targets and spurred development of novel targeted therapeutic agents. The MET receptor tyrosine kinase and its ligand hepatocyte growth factor (HGF) are implicated in tumor cell proliferation, migration, invasion, and angiogenesis in a broad spectrum of human cancers, including NSCLC. Amplification of MET has been reported in approximately 5%–22% of lung tumors with acquired resistance to small-molecule inhibitors of the epidermal growth factor receptor (EGFR). Resistance to EGFR inhibitors is likely mediated through downstream activation of the phosphoinositide 3-kinase /AKT pathway. Simultaneous treatment of resistant tumors with a MET inhibitor plus an EGFR inhibitor can abrogate activation of downstream effectors of cell growth, proliferation, and survival, thereby overcoming acquired resistance to EGFR inhibitors. Development and preclinical testing of multiple agents targeting the HGF–MET pathway, including monoclonal antibodies targeting HGF or the MET receptor and small-molecule inhibitors of the MET tyrosine kinase, have confirmed the crucial role of this pathway in NSCLC. Several agents are now in phase III clinical development for the treatment of NSCLC. This review summarizes the role of MET in the pathophysiology of NSCLC and in acquired resistance to EGFR inhibitors and provides an update on progress in the clinical development of inhibitors of MET for treatment of NSCLC.
Gypsum attack: performance of silicic pozzolans and Portland cements as determined by ASTM C 452-68
Authors: Talero Rafael
Published: January 2013

An earlier study with metakaolin and 10 Portland cements (PC) suggested that the ASTM C 452-68 test could be used to characterise and differentiate 28-day blended cements prepared with metakaolin. ASTM C 452-68 testing was once again conducted on 67 cements: the above 10 PC and 57 blended cements (POZC) containing 20%, 30% or 40% silica fume or diatomites (D or N) (= Z pozzolan). ASTM C 452-68 specimens were made from all the cements and their daily rate of increase in length was determined. The results showed that in a gypsum and water environment, the pozzolanic reactions induced by the reactive silica, SiO2r−, present in Z pozzolans, prevailed over the sulfatic hydration of the pozzolans themselves, reaching completion within 28 days. The explanation is that the formation rate (Vf) of the calcium silicate hydrate gel and silanol groups from the SiO2r− present in the Z pozzolan finishes being greater than the Vf observed for the ettringite forming slowly (ett-lf) from the C3A of ordinary Portland cement, which declines to zero, even though sulfatic hydration continues. The positive 7 and/or 28-day results obtained with the Frattini test (EN 196-5) and the tests set out in standards EN 450, ASTM C 311-07, EN 13263-1 or ASTM 618-95a provided proof that the ASTM C 452-68 test can be validly used to characterise 28-day POZC prepared with any natural or artificial pozzolan, subject, however, to the establishment of suitable standard physical-chemical requirements and specifications.
Assessment of Learners' Attention to E-Learning by Monitoring Facial Expressions for Computer Network Courses
Authors: Chen Hong-Ren
Published: January 2013

Recognition of students' facial expressions can be used to understand their level of attention. In a traditional classroom setting, teachers guide the classes and continuously monitor and engage the students to evaluate their understanding and progress. Given the current popularity of e-learning environments, it has become important to assess the degree of attention during the online learning process. In this study, we used interactive video-capture facial-recognition technology to automatically detect the facial expressions of students as a means of analyzing their attention state during the e-learning process. Participants were divided into three different learning-strategy groups for a course on computer networks. An attention-detection feedback module evaluated participants' attention span during the learning sessions and initiated a response to redirect the participants' attention when they became distracted. The three groups of participants showed significant differences in their course achievement; this was attributed to the different learning strategies used for content presentation. A positive correlation was found between learning improvement and attention, indicating that video-capture facial-recognition technology can be used to provide timely learning assistance and appropriate stimulation to enhance the educational benefits of e-learning.
A Survey of Factors Contributing to Learners' “Listening” Behaviors in Asynchronous Online Discussions
Authors: Wise Alyssa Friend , Marbouti Farshid , Hsiao Ying-Ting , Hausknecht Simone
Published: January 2013

Sixty-seven undergraduates taking either a Blended Business Course (BBC) or an Online Education Course (OEC) were surveyed about factors influencing their “listening” behaviors in asynchronous online course discussions. These are the ways they attend to the posts made by others: which posts they open, how they engage with open posts, and which posts they choose to respond to. Goal-orientations were also assessed. Results indicate that student decisions about which posts to open relied strongly on discussion reply-structure and message timing; authorship was important only to BBC students. Once open, OEC students often scanned posts to decide whether to read in-depth. In the BBC, similar triage strategies were used by work-avoidant students, while mastery students read posts thoroughly. In deciding which posts to reply to, BBC students favored posts that agreed with them while OEC students favored those that disagreed. Course and student characteristics that may account for these differences are discussed and implications for research and practice are presented.
SpaceSafari
Authors: Scarlatos Tony
Published: January 2013

Exploring the Solar System in the elementary school curriculum has traditionally involved activities, such as building scale models, to help students visualize the vastness of space and the relative size of the planets and their orbits. Today, numerous websites provide a wealth of information about the sun and the planets, combining text, photos, and graphics, and even interactive models. Some sites also include lesson plans and suggested classroom activities. Yet none of these resources allow for development of a lesson plan interactively, or offer tracking of student performance. Many lesson plans also have materials or space requirements that are impractical for some schools. SpaceSafari is an interactive multimedia software program for learning about the solar system that integrates information, exploration, and instruction. It employs a real-time 3D space for navigation, a module for learning about the planets, and an administrative interface for creating activities and tracking student progress. The design of the software resembles a first-person adventure game: a treasure hunt through the solar system in which the missions are created by the teacher. SpaceSafari was developed for both the formal (classroom) and informal (home) learning spaces, with a choice of input modes and display options. This integrated solution for teaching elementary Astronomy using personal computers poses an intriguing research question: “What is the impact of game mechanics, combined with an immersive, kinesthetic, 3D interface, on learning outcomes about the solar system?” Scarlatos, 2008–2009). Once centralized data collection is implemented, a study will be designed to assess the usability of SpaceSafari and the efficacy of its novel approach to teaching elementary Astronomy. Pending IRB approval, the study could begin in the fall of 2013.
QR Codes in Higher ED: Fad or Functional Tool?
Authors: Gradel Kathleen , Edson Alden J.
Published: January 2013

As higher education grapples with addressing the 21st century needs of learners, technology is a pervasive concern. Waters (2012) painted a picture of three historical “screens,” namely the television screen, the computer monitor, and today's mobile device screen. As mobile devices become increasingly commonplace in the workplace and on the street, educators are faced with challenges to staying updated, infusing relevant use, and engaging students who are both media-savvy and device-dependent (Edson & Gradel, 2011; Gradel, 2012). Quick Response (QR) codes—easy-to-use links from offline to online content—may be functional “hooks” to making mobilism more relevant to student learning and engagement in higher education. This article addresses: basics about QR codes, popular and research literature, and recommended cross-discipline applications and efficiencies in higher education.
Assessment Study of an Undergraduate Research Training Abroad Program
Authors: Nieto-Fernandez Fernando , Race Kathryn , Quarless Duncan A.
Published: January 2013

The Old Westbury Neuroscience International Research Program (OWNIP) encourages undergraduate students from health disparities populations and underrepresented minorities to pursue careers in basic science, biomedical, clinical, and behavioral health research fields. To evaluate this program, several measures were used tracked through an online learning management system (ModdleMentors and Angel), including: science related perceptions by students; student program assessments; laboratory performance of students evaluated by mentors; and (since 2011) student performance of weekly and biweekly online deliverables, a journal entry, and a research report. Herein we describe our more broad-based approach to program evaluations of this type, including the articulation of a full program model linking key program elements with priority outcomes, and the reporting of findings from the first and second cohort of students who participated in the summers of 2010 and 2011 and the tracking of students who have participated since the inception of the program in 1994.
A characterization of p-bases of rings of constants
Authors: Jędrzejewicz Piotr
Published: January 2013

We obtain two equivalent conditions for m polynomials in n variables to form a p-basis of a ring of constants of some polynomial K-derivation, where K is a unique factorization domain of characteristic p > 0. One of these conditions involves Jacobians while the other some properties of factors. In the case m = n this extends the known theorem of Nousiainen, and we obtain a new formulation of the Jacobian conjecture in positive characteristic.
Interpretations of cosmological spectral shifts
Authors: Østvang Dag
Published: January 2013

It is shown that for Robertson-Walker models with flat or closed space sections, all of the cosmological spectral shift can be attributed to the non-flat connection (and thus indirectly to space-time curvature). For Robertson-Walker models with hyperbolic space sections, it is shown that cosmological spectral shifts uniquely split up into “kinematic” and “gravitational” parts provided that distances are small. For large distances no such unique split-up exists in general. A number of common, but incorrect assertions found in the literature regarding interpretations of cosmological spectral shifts, is pointed out.
Integration of plug-in hybrid electric vehicles (PHEV) with grid connected residential photovoltaic energy systems
Authors: Nagarajan Adarsh , Shireen Wajiha
Published: January 2013

This paper proposes an approach for integrating Plug-In Hybrid Electric Vehicles (PHEV) to an existing residential photovoltaic system, to control and optimize the power consumption of residential load. Control involves determining the source from which residential load will be catered, where as optimization of power flow reduces the stress on the grid. The system built to achieve the goal is a combination of the existing residential photovoltaic system, PHEV, Power Conditioning Unit (PCU), and a controller. The PCU involves two DC-DC Boost Converters and an inverter. This paper emphasizes on developing the controller logic and its implementation in order to accommodate the flexibility and benefits of the proposed integrated system. The proposed controller logic has been simulated using MATLAB SIMULINK and further implemented using Digital Signal Processor (DSP) microcontroller, TMS320F28035, from Texas Instruments
Oxygen uptake in relation to body weight in a Hillstream fish Glyptothorax telchitta (Ham.)
Authors: Subba Bharat Raj , Ghosh Tapan Kumar
Published: January 2013

Oxygen uptake (VO2) through the gills of a hill-stream fish Glyptothorax telchitta from the Saptakoshi river (Nepal) has been studied in relation to different body weights. The oxygen uptake was determined at 24.0±1°C using a cylindrical glass respirometer with continuous water flow system. The aquatic oxygen uptake through the gills increased from 1.048 to 8.115 mlO2 kg-1.h-1 within the body weight range of 3.215 to 31.355 g. A fish of 17.052 g average body weight consumes 4.461 mlO2-1.h-1. The relation between oxygen uptake (VO2) and body weight was determined by performing regression analysis using logarithmic transformation. It has been found that with a unit increase in body weight, the oxygen uptake per unit time (mlO2h-1) increases by a power of 0.930 showing significant positive correlation whereas, the weight specific oxygen uptake decreases by a power of 0.070 showing significant but negative correlation. DOI: http://dx.doi.org/10.3126/njbs.v1i0.7464 Nepalese Journal of Biosciences 1: 11-18 (2011)
Studies on birds of Biratnagar Sub-Metropolis, Nepal
Authors: Jha Kanchan , Subba Bharat Raj
Published: January 2013

Biratnagar sub-metropolis is a good habitat for several bird species but in the past three decades drastic changes have taken place in the environment of this place because of anthropogenic activities. Several commonly visible birds’ species do not turn out at present. Habitats of birds have shrunk here in such a way that very limited species of birds have become successful to show representatives in this situation. Considering gradual loss of habitats and their inhabitants, an attempt was made to study the present bird status. In the observation of seven months, seventy two species of birds belonging to thirty two families were recorded. The birds recorded, were residents (72.17%), winter visitors (23.59%) and summer visitors (4.16%). DOI: http://dx.doi.org/10.3126/njbs.v1i0.7468 Nepalese Journal of Biosciences 1: 37-40 (2011)
Vegetation record around a cement factory and the impact of dust pollution on crop productivity
Authors: Chapagain Narahari , Dhakal Min Raj
Published: January 2013

Effect of cement dust pollution on crop productivity in the environment of Himal Cement Factory, Kathmandu, Nepal has been studied. The productivity of the crops like wheat, maize and mustard were significantly low in the fields 1.5 km around the factory site in comparison to the fields at 3-4-km distance. Productivity of rice was least affected. Polluted area around the cement factory becomes unsuitable for vegetable production due to deposition of dust particles on the leaves. A list of plants growing around the factory has also been presented. DOI: http://dx.doi.org/10.3126/njbs.v1i0.7472 Nepalese Journal of Biosciences 1: 55-62 (2011)
Algal flora of Betana wetland, Morang, Nepal
Authors: Rai Shiva Kumar
Published: January 2013

In this paper, a total 23 epiphytic as well as planktonic taxa belonging to the classes cyanophyceae (6), chlorophyceae (1) and bacillariophyceae (16) have been enumerated from Betana wetland. Out of these, six diatom taxa viz., Gomphonema constrictum Ehr. var. capitata, Gomphonema intricatum Kütz. var. vibrio, Gomphonema parvulum (Kütz.) var. lagenula Hust., Rhopalodia gibba (Ehr.) O. Müll. var. ventricosa, Nitzschia amphibia Grun. and Surirella tenera Greg. var. ambigua Gandhi were the new records for the country. DOI: http://dx.doi.org/10.3126/njbs.v1i0.7477 Nepalese Journal of Biosciences 1: 104-113 (2011)
Restoration in soil and plant properties in landslide damaged forest ecosystem
Authors: Mandal Tej Narayan
Published: January 2013

The pattern of natural restoration in soil and plant components was studied in five landslide-damaged (1-58-year-old) sites in the tropical moist sal (Shorea robusta) forest ecosystem of Nepal Himalaya .Rate of restoration in soil properties was faster in the early successional stages (1-15 year) than late stages while plant biomass recovered rapidly after 15-year age. Based on the recovery in ecosystem properties; the 58- year-old landslide damaged site demonstrated the re-establishment of an ecosystem showing closer affinity with the mature sal forest. On the basis of best fit power function models it was concluded that the estimated times for the 58-year old site to reach the level of undisturbed matured sal forest would be about 30-35 years for microbial biomass (C and N) and plant biomass and about 100-150 year for soil organic Carbon and total N. Higher accumulation of soil microbial biomass, plant biomass and high N-mineralization rate at late successional stages indicated the re-establishment of an ecosystem with enriched soil and restitution of nutrient cycling during the course of ecosystem restoration DOI: http://dx.doi.org/10.3126/njbs.v2i0.7488 Nepalese Journal of Biosciences 2 : 40-45 (2012)
Physico-chemical properties of Seepage stream at Shripur area, eastern Nepal
Authors: Chhetry Damodar Thapa , Pal Joydeb
Published: January 2013

Physico-chemical parameters of the Seepage stream of Shripur area were studied for two years from July, 2002 to June, 2004, once in every month at regular intervals. The maximum air temperature was recorded in rainy season during first year (July, 2002 to June, 2003) and second year study period (July, 2003 to June, 2004). Water temperature was maximum in summer and lowest in winter season. Transparency, total alkalinity, total hardness, chloride were maximum in winter season. Free CO2 and BOD was maximum in summer season. The minimum transparency, total alkalinity, total hardness and chloride were recorded in rainy season. DO and pH were maximum in winter and minimum in summer season during the whole study period. Air temperature, water temperature, free CO2, BOD showed positive and significant correlation with each other. Transparency showed positive and significant correlation with pH, DO, total alkalinity, total hardness and chloride. pH showed positive and significant correlation with DO and chloride. Similarly, DO, total alkalinity, total hardness and chloride showed positive and significant correlation with each other. DOI: http://dx.doi.org/10.3126/njbs.v2i0.7489 Nepalese Journal of Biosciences 2 : 46-54 (2012)
Indigenous knowledge on common medicinal plants among Raji Community of Surkhet district, mid-western Nepal
Authors: Thapa Lal Bahadur
Published: January 2013

Rajis are one of the endangered indigenous tribe of Nepal distributed natively in Surkhet. In present situation the Rajis are in great pressure to change their ways of practice, belief, decision making and harvesting plant resources due to increasing population, migration and modernization. The present paper highlights the indigenous knowledge and practice of medicine preparation from common ten medicinal plants of their localities, transformation of the knowledge and response of respondents on conservation and management of medicinal plants. DOI: http://dx.doi.org/10.3126/njbs.v2i0.7494 Nepalese Journal of Biosciences 2 : 88-92 (2012)
Impact of climate change on food value of molluscs in Nepal
Authors: Subba Bharat Raj
Published: January 2013

The questionnaires and interviews were taken randomly with ethnic people, the molluscs consumers of different districts of Tarai regions. Regarding other information about the impact of climate change in the context of Nepal, literature survey was done. Edible molluscs are cheap non-conventional source of protein for huge population of poor ethnic peoples (53 castes living in twenty districts of Tarai in Nepal), from time immemorial. Up to, nearly four and half decades back, there were virgin forests in Tarai region, water sources were in better condition but because of rapid population explosion, encroachment of wetlands and deforestation the water sources began to dry up early in the year. Gradual increase in atmospheric temperature due to imbalanced amount of CO2 and precipitation, is worsening the environment. The climate change is not only destroying the suitable aquatic environment of the molluscs habitats but their foods of plant and animal origins as well. Several changes in water chemistry might have taken place threatening aquatic lives including molluscs. As a result, annual production of mollusc also has decreased. The climate change is enforcing molluscs to change their original habitats and habits. While their production of molluscs is decreasing, demand is increasing due to rapid human population growth. The price of molluscs meat also has increased 100% as compared to one decade back (Bellamya Rs 20-25/kg with shell, Pila without shell Rs 48-60/kg, similarly bivalves (Lamellidens and Parreysia) Rs 20-30/kg with shell whereas Rs 50-60/kg without shell; Brotia Rs 10-12/kg with shell). Local production of Nepal covers hardly 30-40% demand of molluscs. The rest 60% demand is met imported from India. The only solution of the problem is to initiate molluscs culture which will also help conserve water sources and other aquatic organisms as well. DOI: http://dx.doi.org/10.3126/njbs.v2i0.7496 Nepalese Journal of Biosciences 2 : 98-108 (2012)
Histopathological changes in the gills of some fishes inhabiting polluted Singhiya river, Biratnagar, Nepal
Authors: Subba Bharat Raj , Khanal Bikash
Published: January 2013

Histopathological effects on the gills of a few fish species of polluted Singhiya river, Biratnagar sub-metropolis was made. The gills sections of Oxygaster bacaila, Neomacheilus botia,, Glossogobius giuris, Puntius sophore, Barillius barana, Channa gachua and Silorhynchus sucatio were found much deformed. Lesions, abnormal growth of taste buds and inter-lamellar space, fusion at the tips of primary as well as secondary lamellae, shifting of epithelial layer, deformation of gill head and that of outer margin, tilted secondary lamellae were found common. DOI: http://dx.doi.org/10.3126/njbs.v2i0.7498 Nepalese Journal of Biosciences 2 : 113-117 (2012)