bluuebunny/crossref_metadata_2025 huggingface dataset:
Mathematics lesson study in the United States
Authors: Yoshida Makoto
Published: May 2012

Purpose

Teachers in the USA have been conducting lesson study for more than ten years since it was introduced from Japan in the late 1990s. Although interest in conducting lesson study in the USA is still strong and greater numbers of teachers have become involved in this professional learning, there are significant obstacles to conducting high quality and effective lesson study that enhances teachers’ content and pedagogical knowledge, as well as improving their instruction and student learning in classrooms. Because of the needs of improvement in lesson study in the USA, so it can be administered effectively and sustained, the purpose of this paper is to discuss the current status of lesson study in the USA, what high quality and effective lesson study is, and what ideas might be help to improve lesson study in the USA.

Design/methodology/approach

In this paper, issues that are common barriers to conducting effective lesson study, such as: US teachers’ misunderstanding or lack of understanding of lesson study; teachers’ insufficient knowledge of content, pedagogical content, curriculum knowledge; lack of support from administrators for lesson study; non‐systematic approach to implement lesson study; and having short‐sighted vision to conduct lesson study will be discussed. The discussions are based on the author's 12 years of experience working with teachers, schools, and school districts in the USA, interactions and information exchanges with other lesson study educators and researchers and professional development coordinators in schools and districts in the USA, and existing research documents in the USA. Through this discussion, the author attempts to provide suggestions for improving lesson study in the USA.

Findings

In order for lesson study to be successful, teachers need to think of lesson study as a way to improve their own learning as well as student learning. Spending more time studying mathematical content and curriculum, developing a strong pedagogical content knowledge with colleagues, and establishing a professional community of learning through lesson study will help it to be effective for improving classroom teaching and learning.

Originality/value

The paper provides some helpful suggestions for improving quality and effectiveness of lesson study in order to improve: classroom teaching – teacher's content, pedagogical content and curriculum knowledge; and student learning. The paper is particularly valuable for lesson study practitioners, and administrators and staff developers who are implementing lesson study in schools.
Effects of surgically implanted PIT tags on growth, survival and tag retention of yellow shortfin eels Anguilla australis under laboratory conditions
Authors: Hirt‐Chabbert J. A. , Young O. A.
Published: May 2012

This study evaluated the effects of surgically implanted passive integrated transponder (PIT) tags on growth rate, survival and tag retention of yellow shortfin eels Anguilla australis with an initial mean mass of 101 g. There were no significant differences in body mass, total length, specific growth rate and survival between tagged and untagged A. australis in a 108 day laboratory trial. This tagging method was very reliable, with a tag retention of >95%.
Effects of contrasting omnivorous fish on submerged macrophyte biomass in temperate lakes: a mesocosm experiment
Authors: DORENBOSCH MARTIJN , BAKKER ELISABETH S.
Published: May 2012

1. Freshwater fish can affect aquatic vegetation directly by consuming macrophytes or indirectly by changing water quality. However, most fish in the temperate climate zone have an omnivorous diet. The impact of fish as aquatic herbivores in temperate climates therefore remains unclear and depends on their dietary flexibility.

2. We tested the effects of a flexible omnivore and an herbivore on aquatic vegetation by comparing the effects of rudd (Scardinius erythrophthalmus, the most herbivorous fish in temperate climates) with grass carp (Ctenopharyngodon idella) in a mesocosm pond study. Exclosures distinguished herbivorous effects of fish on submerged macrophytes from indirect effects through changes in water quality, whereas stable isotope food‐web analysis provided information on fish diets.

3. We hypothesised that rudd, with its flexible diet and preference for animal food items, would only indirectly affect macrophytes, whereas grass carp, with its inflexible herbivorous diet, would directly affect macrophyte biomass.

4. Only grass carp significantly reduced macrophyte biomass through consumption. Rudd had no effect. Food‐web analysis indicated that rudd predominantly consumed animal prey, whereas grass carp included more plants in their diet, although they also consumed animal prey. Grass carp significantly affected water quality, resulting in lowered pH and increased N‐NH4 concentrations, whereas more periphyton growth was observed in the presence of rudd. However, the indirect non‐herbivorous effects of both fish species had no effect on macrophyte biomass.

5. Both fish species should be considered as omnivores. Despite the fact that rudd is the most herbivorous fish in the western European climate zone, its effect on submerged macrophyte biomass is not substantial at natural densities and current temperatures.
Genome‐wide binding‐site analysis of REVOLUTA reveals a link between leaf patterning and light‐mediated growth responses
Authors: Brandt Ronny , Salla‐Martret Mercè , Bou‐Torrent Jordi , Musielak Thomas , Stahl Mark , Lanz Christa , Ott Felix , Schmid Markus , Greb Thomas , Schwarz Martina , Choi Sang‐Bong , Barton M. Kathryn , Reinhart Brenda J. , Liu Tie , Quint Marcel , Palauqui Jean‐Christophe , Martínez‐García Jaime F , Wenkel Stephan
Published: May 2012

Unlike the situation in animals, the final morphology of the plant body is highly modulated by the environment. During Arabidopsis development, intrinsic factors provide the framework for basic patterning processes. CLASS III HOMEODOMAIN LEUCINE ZIPPER (HD‐ZIPIII) transcription factors are involved in embryo, shoot and root patterning. During vegetative growth HD‐ZIPIII proteins control several polarity set‐up processes such as in leaves and the vascular system. We have identified several direct target genes of the HD‐ZIPIII transcription factor REVOLUTA (REV) using a chromatin immunoprecipitation/DNA sequencing (ChIP‐Seq) approach. This analysis revealed that REV acts upstream of auxin biosynthesis and affects directly the expression of several class II HD‐ZIP transcription factors that have been shown to act in the shade‐avoidance response pathway. We show that, as well as involvement in basic patterning, HD‐ZIPIII transcription factors have a critical role in the control of the elongation growth that is induced when plants experience shade. Leaf polarity is established by the opposed actions of HD‐ZIPIII and KANADI transcription factors. Finally, our study reveals that the module that consists of HD‐ZIPIII/KANADI transcription factors controls shade growth antagonistically and that this antagonism is manifested in the opposed regulation of shared target genes.
The Role of Dialectical Self and Bicultural Identity Integration in Psychological Adjustment
Authors: Chen Sylvia Xiaohua , Benet‐Martínez Verónica , Wu Wesley C. H. , Lam Ben C. P. , Bond Michael Harris
Published: May 2012

Objective

We applied the concept of naïve dialecticism (Peng & Nisbett,), which characterizesEastAsians’ greater tendency to encompass contradictory, ever‐changing, and interrelated features of an entity, to bicultural contexts and examined its effects on psychological well‐being across various acculturating groups.

Method

We administered questionnaire measures of the dialectical self, bicultural identity integration (BII;Benet‐Martínez &Haritatos, 2005), and well‐being toHongKongChinese (N = 213) in Study 1 andMainlandChinese (N = 239) in Study 2. In Study 3, a 4‐week longitudinal study was conducted amongHongKongChinese (N = 173) to test the relationships of these variables over time. We then extended similar measures to new immigrants fromMainlandChina (N = 67) in Study 4 andFilipino domestic workers inHongKong (N = 153) in Study 5.

Results

Five studies converged to show that psychological adjustment was positively related toBII, but negatively related to the dialectical self. In Studies 1–3, dialecticism mediated the effect ofBIIon psychological adjustment amongHongKong andMainlandChinese bicultural individuals.

Conclusions

Our findings reveal the deleterious effects of tolerance for contradiction on well‐being and differentiate biculturalism patterns of immigration‐based and globalization‐based acculturation.
Self‐Other Knowledge Asymmetries in Personality Pathology
Authors: Carlson Erika N. , Vazire Simine , Oltmanns Thomas F.
Published: May 2012

Objective

Self‐reports of personality provide valid information about personality disorders (PDs). However, informant reports provide information about PDs that self‐reports alone do not provide. The current article examines whether and when one perspective is more valid than the other in identifying PDs.

Method

Using a representative sample of adults 55 to 65 years of age (N = 991; 45% males), we compared the validity of self‐ and informant (e.g., spouse, family, or friend) reports of the Five‐Factor Model traits in predicting PD scores (i.e., composite of interviewer, self‐, and informant reports of PDs).

Results

Self‐reports (particularly of Neuroticism) were more valid than informant reports for most internalizing PDs (i.e., PDs defined by high Neuroticism). Informant reports (particularly of Agreeableness and Conscientiousness) were more valid than self‐reports for externalizing and/or antagonistic PDs (i.e., PDs defined by low Agreeableness and Conscientiousness). Neither report was consistently more valid for thought disorder PDs (i.e., PDs defined by low Extraversion). However, informant reports (particularly of Agreeableness) were more valid than self‐reports for PDs that were both internalizing and externalizing (i.e., PDs defined by high Neuroticism and low Agreeableness).

Conclusions

The intrapersonal and interpersonal manifestations of PDs differ, and these differences influence who knows more about pathology.
Disentangling respiratory acclimation and adaptation to growth temperature by Eucalyptus
Authors: Kruse Jörg , Turnbull Tarryn L. , Adams Mark A.
Published: May 2012

Respiratory acclimation to growth temperature differs between species, but underlying mechanisms are poorly understood. In the present study, we tested the hypothesis that respiratory acclimation of CO2 release is a consequence of growth regulation such that growth rates of young foliage of Eucalyptus spp. are similar at contrasting growth temperatures. Further, we tested whether such a response is affected by adaptation of Eucalyptus to different thermal environments via growth at different altitudes in the Australian Alps.

We employed calorimetric methods to relate rates of CO2 release (mainly from substrate oxidation) and rates of O2 reduction to conservation of energy. Temperature responses of these processes provided insight into mechanisms that control energy conservation and expenditure, and helped define ‘instantaneous enthalpic growth capacity’ (CapG).

CapG increased with altitude, but was counteracted by other factors in species adapted to highland habitats. The acclimation response was partly driven by changes in respiratory capacity (), and partly by more pronounced dynamic responses of CO2 release to measurement temperature. We observed enhanced temperature sensitivity of O2 reduction at higher altitudes.

Adaptation to growth temperature included differences in respiration and growth capacities, but there was little evidence that Eucalyptus species vary in metabolic flexibility.
Preserved Capillary Density of Dorsal Finger Skin in Treated Hypertensive Patients with or without Type 2 Diabetes
Authors: AELLEN JEROME , DABIRI AMIN , HEIM ABIGAEL , LIAUDET LUCAS , BURNIER MICHEL , RUIZ JUAN , FEIHL FRANÇOIS , WAEBER BERNARD
Published: May 2012

Please cite this paper as: Aellen J, Dabiri A, Heim A, Liaudet L, Burnier M, Ruiz J, Feihl F, Waeber B. Preserved capillary density of dorsal finger skin in treated hypertensive patients with or without type 2 diabetes. Microcirculation 19: 554–562, 2012.

Objectives:  Capillary rarefaction is a hallmark of untreated hypertension. Recent data indicate that rarefaction may be reversed by antihypertensive treatment in nondiabetic hypertensive patients. Despite the frequent association of diabetes with hypertension, nothing is known on the capillary density of treated diabetic patients with hypertension.

Methods:  We enrolled 21 normotensive healthy, 25 hypertensive only, and 21 diabetic (type 2) hypertensive subjects. All hypertensive patients were treated with a blocker of the renin‐angiotensin system, and a majority had a home blood pressure ≤135/85 mmHg. Capillary density was assessed with videomicroscopy on dorsal finger skin and with laser Doppler imaging on forearm skin (maximal vasodilation elicited by local heating).

Results:  There was no difference between any of the study groups in either dorsal finger skin capillary density (controls 101 ± 11 capillaries/mm2, nondiabetic hypertensive 99 ± 16, diabetic hypertensive 96 ± 18, p > 0.5) or maximal blood flow in forearm skin (controls 666 ± 114 perfusion units, nondiabetic hypertensive 612 ± 126, diabetic hypertensive 620 ± 103, p > 0.5).

Conclusions:  Irrespective of the presence or not of type 2 diabetes, capillary density is normal in hypertensive patients with reasonable control of blood pressure achieved with a blocker of the renin‐angiotensin system.
‘English leaflets are not meant for me’: a qualitative approach to explore oral health literacy in Chinese mothers in Southwestern Sydney, Australia
Authors: Arora Amit , Liu Mandy NM. , Chan Rainbow , Schwarz Eli
Published: May 2012

Objectives

The aim of this study was to record the views of Chinese mothers living in southwestern Sydney on the value of commonly used dental health education materials that gave behavioural advice on looking after the oral health of young children.

Methods

This qualitative study was nested within a large cohort study in south‐western Sydney. Chinese‐speaking mothers (n = 27) with young children were approached for a face‐to‐face, semi‐structured interview at their home. Two dental leaflets in English that gave behavioural advice on monitoring young children's oral health were sent to each mother prior to interview. On the day of the interview, mothers were also given translated versions of the leaflets for comparison. Interviews were recorded and subsequently transcribed verbatim. Transcripts were analysed by thematic coding.

Results

Mothers reported that the leaflets were not tailored to match the different levels of English literacy within the Chinese community, and participants favoured health information material written in their first language with the use of illustrations. However, translations had to take account of the Chinese culture, as some of the advice in the leaflets presented did not reflect Chinese family values. Mothers also felt that the information should be more specific to provide a better understanding of the rationale for changing or implementing a different behaviour.

Conclusions

Dental health information literature for Chinese people should not be translated directly from those intended for an English‐speaking audience, but should reflect Chinese culture–specific advice such as examples of the type and amount of foods to be given during early years of life. Supportive illustrations were also preferred.
Skin exposure to epoxy in the pipe relining trade–an observational study
Authors: Fillenham George , Lidén Carola , Anveden Berglind Ingegärd
Published: May 2012

Background. Epoxy resin systems (ERSs) are frequent causes of occupational allergic contact dermatitis. Epoxy pipe relining has become a widely used alternative to replacing old and worn drain pipes in housing, and involves a high risk of skin exposure to ERSs.

Objectives. To map out work methods, protective measures and skin and surface contamination among workers involved in epoxy pipe relining, as a basis for prevention of occupational skin disease.

Methods. Twenty‐one employees in eight relining companies in Stockholm County were observed. Contact and contamination with ERSs and the use of personal protective equipment during relining work were noted.

Results. Contamination by uncured ERSs on gloves, personal and shared tools and work areas was identified during mixing, wetting, installation, and cleaning. The gloves used were often inadequate for handling ERSs.

Conclusions. Relining pipes poses an extensive risk of uncured ERS exposure, and contamination was identified during the whole work process. Shared and personal tools and work areas were extensively contaminated. Changes in work routines and logistics for handling ERSs are essential, and knowledge among both employers and employees regarding the risks caused by ERS exposure is vital to create a safe work environment and prevent contact allergies.
Toll‐like receptor 7 agonist, Imiquimod, inhibits oral squamous carcinoma cells through apoptosis and necrosis
Authors: Ahn Mee‐Young , Kwon Seong‐Min , Cheong Hak Hyun , Park Jong‐Hwan , Lee Jun , Min Seung‐Ki , Ahn Sang‐Gun , Yoon Jung‐Hoon
Published: May 2012

J Oral Pathol Med (2012) 41: 540–546

Background:  Toll‐like receptor (TLR) agonists have anticancer effect by inducing apoptosis or activating immune cells. In this study, we investigated whether imiquimod, TLR7 agonist, inhibits the proliferation of oral cancer cells.

Methods:  Toll‐like receptor 7 expression and IL‐6/8 production by imiquimod were examined using RT‐PCR and Enzyme‐linked immunosorbent assay, respectively. Cell viability was examined by MTT assay. To examine apoptotic cell death, Annexin V/PI staining for flow cytometry and Western blot analysis were performed. Necrotic cell death was determined by leakage of lactate dehydrogenase (LDH), HMGB1, and PI staining in imiquimod‐treated oral squamous cell carcinoma (OSCC) cells.

Results:  Toll‐like receptor7 mRNA was expressed in OSCC cells. Imiquimod induced IL‐6 and IL‐8 production in OSCC cells, suggesting the functional expression of TLR7. Imiquimod inhibited cells proliferation in a dose‐dependent manner. The ratio of annexin V‐positive cells and cleaved caspase‐3/7 was increased by imiquimod treatment in OSCC cells, suggesting that imiquimod‐induced cell death in OSCC cells may be owing to apoptosis. In addition, LDH secretion and PI staining were detected in OSCC cells treated with imiquimod, showing that imiquimod also induced necrotic cell death in the OSCC cells.

Conclusions:  Imiquimod inhibited effectively the growth of OSCC cells by inducing apoptosis and necrosis.
MAML2 rearrangement in Warthin’s tumour: a fluorescent in situ hybridisation study of metaplastic variants
Authors: Rotellini Matteo , Paglierani Milena , Pepi Monica , Franchi Alessandro
Published: May 2012

J Oral Pathol Med (2012) 41: 615–620

Background:  Warthin’s tumour (WT) is a common benign lesion of the major salivary glands. The nature of WT remains controversial, with particular regard to the presence of clonal chromosomal abnormalities, including the t(11;19) translocation involving the CRTC1 and MAML2 genes, that have been identified in both WT and mucoepidermoid carcinoma. In this study, we focused our attention on metaplastic WT variants, and we conducted a fluorescent in situ hybridisation (FISH) analysis for the presence of MAML2 gene rearrangement.

Methods:  Dual‐colour FISH analysis was performed on paraffin‐embedded sections of eight WTs showing metaplastic changes (five with squamous metaplasia, two with mucinous metaplasia and one with both) using a MAML2 break‐apart probe.

Results:  Presence of split signals indicative of gene rearrangement was identified in a subset of cells in areas of squamous metaplasia in two samples of WT. No rearrangement was observed in the oncocytic epithelium, in lymphocytes and in areas of mucinous metaplasia.

Conclusions:  The presence of a small subpopulation of cells carrying MAML2 rearrangement in areas of squamous metaplasia within WT could predispose these lesions to malignant transformation in mucoepidermoid carcinoma and could represent a molecular link between the two entities.
Discovery and Structural Characterization of a Phospholamban‐Binding Cyclic Peptide and Design of Novel Inhibitors of Phospholamban
Authors: Tilgmann Carola , Pollesello Piero , Ovaska Martti , Kaivola Juha , Pystynen Jarmo , Tiainen Eija , Yliperttula Marjo , Annila Arto , Levijoki Jouko
Published: May 2012

The interplay between cardiac sarcoplasmic Ca2+ATPase and phospholamban is a key regulating factor of contraction and relaxation in the cardiac muscle. In heart failure, aberrations in the inhibition of sarcoplasmic Ca2+ATPase by phospholamban are associated with anomalies in cardiac functions. In experimental heart failure models, modulation of the interaction between these two proteins has been shown to be a potential therapeutic approach. The aim of our research was to find molecules able to interfere with the inhibitory activity of phospholamban on sarcoplasmic Ca2+ATPase. For this purpose, a portion of phospholamban was synthesized and used as target for a phage‐display peptide library screening. The cyclic peptide C‐Y‐W‐E‐L‐E‐W‐L‐P‐C‐A was found to bind to phospholamban (1–36) with high specificity. Its functional activity was tested in Ca2+uptake assays utilizing preparations from cardiac sarcoplasmic reticulum. By synthesizing and testing a series of alanine point‐mutated cyclic peptides, we identified which amino acid was important for the inhibition of the phospholamban function. The structures of active and inactive alanine‐mutated cyclic peptides, and of phospholamban (1–36), were determined by NMR. This structure–activity analysis allowed building a model of phospholamban –cyclic peptide complex. Thereafter, a simple pharmacophore was defined and used for the design of small molecules. Finally, examples of such molecules were synthesized and characterized as phospholamban inhibitors.
Contesting Water Rights: Collective Ownership and Struggles against Privatization
Authors: Subramaniam Mangala , Williford Beth
Published: May 2012

The post‐1980s have seen increasing struggles over rights to water. Water rights have involved intense protests and campaigns against privatization of water including bottling of water and advocacy for citizens control of water. We review scholarly work to focus on four main aspects: the complexities intertwining globalization processes, the state, and water rights; collective ownership of water resources; peoples’ participating in managing and using water; and the campaigns against privatization which have emerged in both the developing and developed world in different ways. The conclusion calls for adopting a social movement lens to examine the struggles for water rights by providing some lead research questions around the macro and micro level theoretical approaches.
Copresence in Virtual Environments
Authors: Campos‐Castillo Celeste
Published: May 2012

Copresence, the sense of “being together” with others, is at the center of theories about social interaction. It is an intra‐individual sense that stems from and shapes the social context. Recent research on copresence in virtual environments (VEs), synthetic simulations of existing experiences (e.g., desktop computer environments, “virtual reality”), demonstrates the variability in which people experience copresence with others who are not sharing in the same time or space. At the same time, experimental researchers in sociology are using VEs as a methodological tool, yet remain unaware about the ramifications of varying levels of copresence for the social processes under investigation. The goal of this review is to introduce sociologists to the research on copresence, specifically highlighting findings and gaps important for those who use VEs in their research practice. An understanding of how copresence occurs in VEs can improve how well sociologists design experiments to advance theories about interpersonal behavior.
Genomic characterisation of acral melanoma cell lines
Authors: Furney Simon J. , Turajlic Samra , Fenwick Kerry , Lambros Maryou B. , MacKay Alan , Ricken Gerda , Mitsopoulos Costas , Kozarewa Iwanka , Hakas Jarle , Zvelebil Marketa , Lord Christopher J. , Ashworth Alan , Reis‐Filho Jorge S. , Herlyn Meenhard , Murata Hiroshi , Marais Richard
Published: May 2012

Acral melanoma is a rare melanoma subtype with distinct epidemiological, clinical and genetic features. To determine if acral melanoma cell lines are representative of this melanoma subtype, six lines were analysed by whole‐exome sequencing and array comparative genomic hybridisation. We demonstrate that the cell lines display a mutation rate that is comparable to that of published primary and metastatic acral melanomas and observe a mutational signature suggestive of UV‐induced mutagenesis in two of the cell lines. Mutations were identified in oncogenes and tumour suppressors previously linked to melanoma including BRAF, NRAS, KIT, PTEN and TP53, in cancer genes not previously linked to melanoma and in genes linked to DNA repair such as BRCA1 and BRCA2. Our findings provide strong circumstantial evidence to suggest that acral melanoma cell lines and acral tumours share genetic features in common and that these cells are therefore valuable tools to investigate the biology of this aggressive melanoma subtype. Data are available at: http://rock.icr.ac.uk/collaborations/Furney_et_al_2012/.
The economic performance of jatropha, cassava and Eucalyptus production systems for energy in an East African smallholder setting
Authors: van Eijck Janske , Smeets Edward , Faaij André
Published: May 2012

This study evaluates the potential economic feasibility of three smallholder energy crop production systems (jatropha, cassava and eucalyptus) under typical semi‐arid conditions in Eastern Africa. This feasibility is determined by assessing net present values (NPV), internal rates of return (IRR), benefit‐cost ratios (BCR) and payback periods (PBP). In addition, the production costs are compared to the costs of reference energy systems, petrol, diesel and pellets. Low and intermediate input systems are considered and specific attention is paid to the opportunity cost of labour, by considering both family labour (no labour costs) and hired labour. The results show that all family labour settings have positive NPVs and high IRR and BCR values. Moreover, cassava has the highest family labour NPV (2900–5800US$ ha−1) and the shortest PBP, but the required investment costs are high in comparision with the other crops. If hired labour is used, the NPV of eucalyptus is highest (380–1400$/ha−1), and it is also the least sensitive to changes in wages and yields. Jatropha performs best only for the indicator IRR and only with family labour or low labour opportunity costs. The analysis and comparison of bioenergy production costs shows that eucalyptus pellets (2.6–3.1$ GJ−1) are competitive compared with reference pellets at current market prices (5$ GJ−1). Jatropha SVO (19$ GJ−1) and cassava ethanol (19–36$ GJ−1) are only competitive with fossil diesel (21$ GJ−1) and petrol (25$ GJ−1) in a family labour setting. At current values jatropha biodiesel (24–37$ GJ−1) is not competitive. The economic performance is sensitive to variations in crop yields and yield data are highly uncertain. However, this study demonstrates that there is considerable potential for increasing the economic performance by further improvements in yield, harvesting efficiency and conversion efficiency as well as reductions in transport and packaging costs.
Simultaneous chromatic and luminance human electroretinogram responses
Authors: Parry Neil R. A. , Murray Ian J. , Panorgias Athanasios , McKeefry Declan J. , Lee Barry B. , Kremers Jan
Published: May 2012

Key points

It has recently been shown that, with careful control over stimulation, the electroretinogram (ERG) can reflect the properties of the post‐receptoral parvocellular (P) and magnocellular (M) pathways, which are thought of as the respective substrates for red–green colour and luminance vision.

Using a novel compound stimulus, which contains red–green colour information at the fundamental frequency and luminance information at the second harmonic, we were able to simultaneously record colour and luminance ERGs.

In trichromats, the temporal tuning curves of these components reflected the known properties of the P and M systems, whereas the dichromats showed negligible chromatic response but a normal achromatic response.

Parallel retinal processing that is relevant for vision can be reflected in the ERG.

Abstract  The parallel processing of information forms an important organisational principle of the primate visual system. Here we describe experiments which use a novel chromatic–achromatic temporal compound stimulus to simultaneously identify colour and luminance specific signals in the human electroretinogram (ERG). Luminance and chromatic components are separated in the stimulus; the luminance modulation has twice the temporal frequency of the chromatic modulation. ERGs were recorded from four trichromatic and two dichromatic subjects (1 deuteranope and 1 protanope). At isoluminance, the fundamental (first harmonic) response was elicited by the chromatic component in the stimulus. The trichromatic ERGs possessed low‐pass temporal tuning characteristics, reflecting the activity of parvocellular post‐receptoral mechanisms. There was very little first harmonic response in the dichromats’ ERGs. The second harmonic response was elicited by the luminance modulation in the compound stimulus and showed, in all subjects, band‐pass temporal tuning characteristic of magnocellular activity. Thus it is possible to concurrently elicit ERG responses from the human retina which reflect processing in both chromatic and luminance pathways. As well as providing a clear demonstration of the parallel nature of chromatic and luminance processing in the human retina, the differences that exist between ERGs from trichromatic and dichromatic subjects point to the existence of interactions between afferent post‐receptoral pathways that are in operation from the earliest stages of visual processing.
Levofloxacin Inhibits Rhinovirus Infection in Primary Cultures of Human Tracheal Epithelial Cells
Authors: Yamaya Mutsuo , Nishimura Hidekazu , Hatachi Yukimasa , Yasuda Hiroyasu , Deng Xue , Sasaki Takahiko , Mizuta Katsumi , Kubo Hiroshi , Nagatomi Ryoichi
Published: May 2012

Respiratory virus infections, including infections with rhinoviruses (RVs), are related to exacerbations of chronic obstructive pulmonary disease (COPD). A new quinolone antibiotic, levofloxacin (LVFX), has been used to treat bacterial infections that cause COPD exacerbations as well as bacterial infections that are secondary to viral infection in COPD patients. However, the inhibitory effects of LVFX on RV infection and RV infection-induced airway inflammation have not been studied. We examined the effects of LVFX on type 14 rhinovirus (RV14) (a major human RV) infection of human tracheal epithelial cells pretreated with LVFX. LVFX pretreatment reduced the RV14 titer, the level of cytokines in the supernatant, the amount of RV14 RNA in the cells after RV14 infection, and the cells' susceptibility to RV14 infection. LVFX pretreatment decreased the mRNA level of intercellular adhesion molecule 1 (ICAM-1), a receptor for RV14, in the cells and the concentration of the soluble form of ICAM-1 in the supernatant before RV14 infection. LVFX pretreatment also decreased the number and the fluorescence intensity of the acidic endosomes from which RV14 RNA enters the cytoplasm. LVFX pretreatment inhibited the activation of nuclear factor κB proteins, including p50 and p65, in nuclear extracts. LVFX pretreatment did not reduce the titers of RV2 (a minor human RV) but reduced the titers of RV15 (a major human RV). These results suggest that LVFX inhibits major-group rhinovirus infections in part by reducing ICAM-1 expression levels and the number of acidic endosomes. LVFX may also modulate airway inflammation in rhinoviral infections.
2-Alkylaminoethyl-1,1-Bisphosphonic Acids Are Potent Inhibitors of the Enzymatic Activity of Trypanosoma cruzi Squalene Synthase
Authors: Rodrígues-Poveda Carlos A. , González-Pacanowska Dolores , Szajnman Sergio H. , Rodríguez Juan B.
Published: May 2012

As part of our efforts aimed at searching for new antiparasitic agents, the effect of representative 2-alkylaminoethyl-1,1-bisphosphonic acids on
Trypanosoma cruzi
squalene synthase (
Tc
SQS) was investigated. These compounds had proven to be potent inhibitors of
T. cruzi
. This cellular activity had been associated with an inhibition of the enzymatic activity of
T. cruzi
farnesyl diphosphate synthase. 2-Alkylaminoethyl-1,1-bisphosphonic acids appear to have a dual action, since they also inhibit
Tc
SQS at the nanomolar range.
Production of the Antimicrobial Secondary Metabolite Indigoidine Contributes to Competitive Surface Colonization by the Marine Roseobacter Phaeobacter sp. Strain Y4I
Authors: Cude W. Nathan , Mooney Jason , Tavanaei Arash A. , Hadden Mary K. , Frank Ashley M. , Gulvik Christopher A. , May Amanda L. , Buchan Alison
Published: May 2012

Members of the
Roseobacter
lineage of marine bacteria are prolific surface colonizers in marine coastal environments, and antimicrobial secondary metabolite production has been hypothesized to provide a competitive advantage to colonizing roseobacters. Here, we report that the roseobacter
Phaeobacter
sp. strain Y4I produces the blue pigment indigoidine via a nonribosomal peptide synthase (NRPS)-based biosynthetic pathway encoded by a novel series of genetically linked genes:
igiBCDFE
. A Tn
5
-based random mutagenesis library of Y4I showed a perfect correlation between indigoidine production by the
Phaeobacter
strain and inhibition of
Vibrio fischeri
on agar plates, revealing a previously unrecognized bioactivity of this molecule. In addition, igiD null mutants (igiD encoding the indigoidine NRPS) were more resistant to hydrogen peroxide, less motile, and faster to colonize an artificial surface than the wild-type strain. Collectively, these data provide evidence for pleiotropic effects of indigoidine production in this strain. Gene expression assays support phenotypic observations and demonstrate that
igiD
gene expression is upregulated during growth on surfaces. Furthermore, competitive cocultures of
V. fischeri
and Y4I show that the production of indigoidine by Y4I significantly inhibits colonization of
V. fischeri
on surfaces. This study is the first to characterize a secondary metabolite produced by an NRPS in roseobacters.
Microbial Degradation of 2,4-Dichlorophenoxyacetic Acid on the Greenland Ice Sheet
Authors: Stibal Marek , Bælum Jacob , Holben William E. , Sørensen Sebastian R. , Jensen Anders , Jacobsen Carsten S.
Published: May 2012

The Greenland ice sheet (GrIS) receives organic carbon (OC) of anthropogenic origin, including pesticides, from the atmosphere and/or local sources, and the fate of these compounds in the ice is currently unknown. The ability of supraglacial heterotrophic microbes to mineralize different types of OC is likely a significant factor determining the fate of anthropogenic OC on the ice sheet. Here we determine the potential of the microbial community from the surface of the GrIS to mineralize the widely used herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Surface ice cores were collected and incubated for up to 529 days in microcosms simulating
in situ
conditions. Mineralization of side chain- and ring-labeled [
14
C]2,4-D was measured in the samples, and quantitative PCR targeting the
tfdA
genes in total DNA extracted from the ice after the experiment was performed. We show that the supraglacial microbial community on the GrIS contains microbes that are capable of degrading 2,4-D and that they are likely present in very low numbers. They can mineralize 2,4-D at a rate of up to 1 nmol per m
2
per day, equivalent to ∼26 ng C m
−2
day
−1
. Thus, the GrIS should not be considered a mere reservoir of all atmospheric contaminants, as it is likely that some deposited compounds will be removed from the system via biodegradation processes before their potential release due to the accelerated melting of the ice sheet.
Accessing the Inaccessible: Molecular Tools for Bifidobacteria
Authors: Sun Zhongke , Baur Annika , Zhurina Daria , Yuan Jing , Riedel Christian U.
Published: May 2012

Bifidobacteria are an important group of the human intestinal microbiota that have been shown to exert a number of beneficial probiotic effects on the health status of their host. Due to these effects, bifidobacteria have attracted strong interest in health care and food industries for probiotic applications and several species are listed as so-called “generally recognized as safe” (GRAS) microorganisms. Moreover, recent studies have pointed out their potential as an alternative or supplementary strategy in tumor therapy or as live vaccines. In order to study the mechanisms by which these organisms exert their beneficial effects and to generate recombinant strains that can be used as drug delivery vectors or live vaccines, appropriate molecular tools are indispensable. This review provides an overview of the currently available methods and tools to generate recombinant strains of bifidobacteria. The currently used protocols for transformation of bifidobacteria, as well as replicons, selection markers, and determinants of expression, will be summarized. We will further discuss promoters, terminators, and localization signals that have been used for successful generation of expression vectors.
Cold Atmospheric Air Plasma Sterilization against Spores and Other Microorganisms of Clinical Interest
Authors: Klämpfl Tobias G. , Isbary Georg , Shimizu Tetsuji , Li Yang-Fang , Zimmermann Julia L. , Stolz Wilhelm , Schlegel Jürgen , Morfill Gregor E. , Schmidt Hans-Ulrich
Published: May 2012

Physical cold atmospheric surface microdischarge (SMD) plasma operating in ambient air has promising properties for the sterilization of sensitive medical devices where conventional methods are not applicable. Furthermore, SMD plasma could revolutionize the field of disinfection at health care facilities. The antimicrobial effects on Gram-negative and Gram-positive bacteria of clinical relevance, as well as the fungus
Candida albicans
, were tested. Thirty seconds of plasma treatment led to a 4 to 6 log
10
CFU reduction on agar plates.
C. albicans
was the hardest to inactivate. The sterilizing effect on standard bioindicators (bacterial endospores) was evaluated on dry test specimens that were wrapped in Tyvek coupons. The experimental
D
23
°
C
values for
Bacillus subtilis
,
Bacillus pumilus
,
Bacillus atrophaeus
, and
Geobacillus stearothermophilus
were determined as 0.3 min, 0.5 min, 0.6 min, and 0.9 min, respectively. These decimal reduction times (
D
values) are distinctly lower than
D
values obtained with other reference methods. Importantly, the high inactivation rate was independent of the material of the test specimen. Possible inactivation mechanisms for relevant microorganisms are briefly discussed, emphasizing the important role of neutral reactive plasma species and pointing to recent diagnostic methods that will contribute to a better understanding of the strong biocidal effect of SMD air plasma.
Galacturonic Acid Inhibits the Growth of Saccharomyces cerevisiae on Galactose, Xylose, and Arabinose
Authors: Huisjes Eline H. , de Hulster Erik , van Dam Jan C. , Pronk Jack T. , van Maris Antonius J. A.
Published: May 2012

The efficient fermentation of mixed substrates is essential for the microbial conversion of second-generation feedstocks, including pectin-rich waste streams such as citrus peel and sugar beet pulp. Galacturonic acid is a major constituent of hydrolysates of these pectin-rich materials. The yeast
Saccharomyces cerevisiae
, the main producer of bioethanol, cannot use this sugar acid. The impact of galacturonic acid on alcoholic fermentation by
S. cerevisiae
was investigated with anaerobic batch cultures grown on mixtures of glucose and galactose at various galacturonic acid concentrations and on a mixture of glucose, xylose, and arabinose. In cultures grown at pH 5.0, which is well above the pK
a
value of galacturonic acid (3.51), the addition of 10 g · liter
−1
galacturonic acid did not affect galactose fermentation kinetics and growth. In cultures grown at pH 3.5, the addition of 10 g · liter
−1
galacturonic acid did not significantly affect glucose consumption. However, at this lower pH, galacturonic acid completely inhibited growth on galactose and reduced galactose consumption rates by 87%. Additionally, it was shown that galacturonic acid strongly inhibits the fermentation of xylose and arabinose by the engineered pentose-fermenting
S. cerevisiae
strain IMS0010. The data indicate that inhibition occurs when nondissociated galacturonic acid is present extracellularly and corroborate the hypothesis that a combination of a decreased substrate uptake rate due to competitive inhibition on Gal2p, an increased energy requirement to maintain cellular homeostasis, and/or an accumulation of galacturonic acid 1-phosphate contributes to the inhibition. The role of galacturonic acid as an inhibitor of sugar fermentation should be considered in the design of yeast fermentation processes based on pectin-rich feedstocks.
Identification and Functional Characterization of Rca1, a Transcription Factor Involved in both Antifungal Susceptibility and Host Response in Candida albicans
Authors: Vandeputte Patrick , Pradervand Sylvain , Ischer Françoise , Coste Alix T. , Ferrari Sélène , Harshman Keith , Sanglard Dominique
Published: May 2012

The identification of novel transcription factors associated with antifungal response may allow the discovery of fungus-specific targets for new therapeutic strategies. A collection of 241
Candida albicans
transcriptional regulator mutants was screened for altered susceptibility to fluconazole, caspofungin, amphotericin B, and 5-fluorocytosine. Thirteen of these mutants not yet identified in terms of their role in antifungal response were further investigated, and the function of one of them, a mutant of orf19.6102 (
RCA1
), was characterized by transcriptome analysis. Strand-specific RNA sequencing and phenotypic tests assigned Rca1 as the regulator of hyphal formation through the cyclic AMP/protein kinase A (cAMP/PKA) signaling pathway and the transcription factor Efg1, but also probably through its interaction with a transcriptional repressor, most likely Tup1. The mechanisms responsible for the high level of resistance to caspofungin and fluconazole observed resulting from
RCA1
deletion were investigated. From our observations, we propose that caspofungin resistance was the consequence of the deregulation of cell wall gene expression and that fluconazole resistance was linked to the modulation of the cAMP/PKA signaling pathway activity. In conclusion, our large-scale screening of a
C. albicans
transcription factor mutant collection allowed the identification of new effectors of the response to antifungals. The functional characterization of Rca1 assigned this transcription factor and its downstream targets as promising candidates for the development of new therapeutic strategies, as Rca1 influences host sensing, hyphal development, and antifungal response.
Expansion of Variant Diversity Associated with a High Prevalence of Pathogen Strain Superinfection under Conditions of Natural Transmission
Authors: Ueti Massaro W. , Tan Yunbing , Broschat Shira L. , Castañeda Ortiz Elizabeth J. , Camacho-Nuez Minerva , Mosqueda Juan J. , Scoles Glen A. , Grimes Matthew , Brayton Kelly A. , Palmer Guy H.
Published: May 2012

Superinfection occurs when a second, genetically distinct pathogen strain infects a host that has already mounted an immune response to a primary strain. For antigenically variant pathogens, the primary strain itself expresses a broad diversity of variants over time. Thus, successful superinfection would require that the secondary strain express a unique set of variants. We tested this hypothesis under conditions of natural transmission in both temperate and tropical regions where, respectively, single-strain infections and strain superinfections of the tick-borne pathogen
Anaplasma marginale
predominate. Our conclusion that strain superinfection is associated with a significant increase in variant diversity is supported by progressive analysis of variant composition: (i) animals with naturally acquired superinfection had a statistically significantly greater number of unique variant sequences than animals either experimentally infected with single strains or infected with a single strain naturally, (ii) the greater number of unique sequences reflected a statistically significant increase in primary structural diversity in the superinfected animals, and (iii) the increase in primary structural diversity reflected increased combinations of the newly identified hypervariable microdomains. The role of population immunity in establishing temporal and spatial patterns of infection and disease has been well established. The results of the present study, which examined strain structure under conditions of natural transmission and population immunity, support that high levels of endemicity also drive pathogen divergence toward greater strain diversity.
DivIVA-Mediated Polar Localization of ComN, a Posttranscriptional Regulator of Bacillus subtilis
Authors: dos Santos Valquiria Tiago , Bisson-Filho Alexandre W. , Gueiros-Filho Frederico J.
Published: May 2012

ComN (YrzD) is a small, 98-amino-acid protein recently shown to be involved in the posttranscriptional control of the late competence
comE
operon in
Bacillus subtilis
. We show here that ComN localizes to the division site and cell poles in a DivIVA-dependent fashion. Yeast two-hybrid and glutathione
S
-transferase pulldown experiments showed that ComN interacts directly with DivIVA. ComN is not essential for the polar assembly of the core competence DNA uptake machinery. Nevertheless, polar localization of ComN should play some role in competence acquisition because delocalization of ComN leads to a small reduction in competence efficiency. We found that ComN promotes the accumulation of its target
comE
mRNA to septal and polar sites. Thus, we speculate that localized translation of ComE proteins may be required for efficient competence development. Our results underscore the versatility of DivIVA as a promoter of the differentiation of bacterial poles and demonstrate that the repertoire of polarly localized molecules in
B. subtilis
is broad, including a regulator of gene expression and its target mRNA. Moreover, our findings suggest that mRNA localization may play a role in the subcellular organization of bacteria.