bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental and Therapeutic Opportunities for Stem Cells in Multiple Sclerosis
Authors: Patani Rickie , Chandran Siddharthan
Published: November 2012

Multiple Sclerosis (MS) is an inflammatory demyelinating neurodegenerative disorder of the brain and spinal cord that causes significant disability in young adults. Although the precise aetiopathogenesis of MS remains unresolved, its pathological hallmarks include inflammation, demyelination, axonal injury (acute and chronic), astrogliosis and variable remyelination. Despite major recent advances in therapeutics for the early stage of the disease there are currently no disease modifying treatments for the progressive stage of disease, whose pathological substrate is axonal degeneration. This represents the great and unmet clinical need in MS. Against this background, human stem cells offer promise both to improve understanding of disease mechanism(s) through in-vitro modeling as well as potentially direct use to supplement and promote remyelination, an endogenous reparative process where entire myelin sheaths are restored to demyelinated axons. Conceptually, stem cells can act directly to myelinate axons or indirectly through different mechanisms to promote endogenous repair; importantly these two mechanisms of action are not mutually exclusive. We propose that discovery of novel methods to invoke or enhance remyelination in MS may be the most effective therapeutic strategy to limit axonal damage and instigate restoration of structure and function in this debilitating condition. Human stem cell derived neurons and glia, including patient specific cells derived through reprogramming, provide an unprecedented experimental system to model MS “in a dish” as well as enable high-throughput drug discovery. Finally, we speculate upon the potential role for stem cell based therapies in MS.
3,5-Bis(4-dodecylthiophen-2-yl)-4H-1,2,6-thiadiazin-4-one
Authors: Ioannidou Heraklidia A. , Koutentis Panayiotis A.
Published: November 2012

3,5-Dichloro-4H-1,2,6-thiadiazin-4-one 1 reacts with (4-dodecylthiophen-2-yl)trimethylstannane 4 (2.2 equiv.) and Pd(Ph3P)2Cl2 (5 mol%) in acetonitrile at ca. 82 °C to give 3,5-bis(4-dodecylthiophen-2-yl)-4H-1,2,6-thiadiazin-4-one 5 in 93% yield.
Epigallocatechin Gallate (EGCG) Is the Most Effective Cancer Chemopreventive Polyphenol in Green Tea
Authors: Du Guang-Jian , Zhang Zhiyu , Wen Xiao-Dong , Yu Chunhao , Calway Tyler , Yuan Chun-Su , Wang Chong-Zhi
Published: November 2012

Green tea is a popular drink consumed daily by millions of people around the world. Previous studies have shown that some polyphenol compounds from green tea possess anticancer activities. However, systemic evaluation was limited. In this study, we determined the cancer chemopreventive potentials of 10 representative polyphenols (caffeic acid, CA; gallic acid, GA; catechin, C; epicatechin, EC; gallocatechin, GC; catechin gallate, CG; gallocatechin gallate, GCG; epicatechin gallate, ECG; epigallocatechin, EGC; and epigallocatechin gallate, EGCG), and explored their structure-activity relationship. The effect of the 10 polyphenol compounds on the proliferation of HCT-116 and SW-480 human colorectal cancer cells was evaluated using an MTS assay. Cell cycle distribution and apoptotic effects were analyzed by flow cytometry after staining with propidium iodide (PI)/RNase or annexin V/PI. Among the 10 polyphenols, EGCG showed the most potent antiproliferative effects, and significantly induced cell cycle arrest in the G1 phase and cell apoptosis. When the relationship between chemical structure and anticancer activity was examined, C and EC did not show antiproliferative effects, and GA showed some antiproliferative effects. When C and EC esterified with GA to produce CG and ECG, the antiproliferative effects were increased significantly. A similar relationship was found between EGC and EGCG. The gallic acid group significantly enhanced catechin’s anticancer potential. This property could be utilized in future semi-synthesis of flavonoid derivatives to develop novel anticancer agents.
Epstein-Barr Virus Sequence Variation—Biology and Disease
Authors: Tzellos Stelios , Farrell Paul
Published: November 2012

Some key questions in Epstein-Barr virus (EBV) biology center on whether naturally occurring sequence differences in the virus affect infection or EBV associated diseases. Understanding the pattern of EBV sequence variation is also important for possible development of EBV vaccines. At present EBV isolates worldwide can be grouped into Type 1 and Type 2, a classification based on the EBNA2 gene sequence. Type 1 EBV is the most prevalent worldwide but Type 2 is common in parts of Africa. Type 1 transforms human B cells into lymphoblastoid cell lines much more efficiently than Type 2 EBV. Molecular mechanisms that may account for this difference in cell transformation are now becoming clearer. Advances in sequencing technology will greatly increase the amount of whole EBV genome data for EBV isolated from different parts of the world. Study of regional variation of EBV strains independent of the Type 1/Type 2 classification and systematic investigation of the relationship between viral strains, infection and disease will become possible. The recent discovery that specific mutation of the EBV EBNA3B gene may be linked to development of diffuse large B cell lymphoma illustrates the importance that mutations in the virus genome may have in infection and human disease.
Simultaneous Measurement of Neural Spike Recordings and Multi-Photon Calcium Imaging in Neuroblastoma Cells
Authors: Kim Suhwan , Jung Unsang , Baek Juyeong , Kang Shinwon , Kim Jeehyun
Published: November 2012

This paper proposes the design and implementation of a micro-electrode array (MEA) for neuroblastoma cell culturing. It also explains the implementation of a multi-photon microscope (MPM) customized for neuroblastoma cell excitation and imaging under ambient light. Electrical signal and fluorescence images were simultaneously acquired from the neuroblastoma cells on the MEA. MPM calcium images of the cultured neuroblastoma cell on the MEA are presented and also the neural activity was acquired through the MEA recording. A calcium green-1 (CG-1) dextran conjugate of 10,000 D molecular weight was used in this experiment for calcium imaging. This study also evaluated the calcium oscillations and neural spike recording of neuroblastoma cells in an epileptic condition. Based on our observation of neural spikes in neuroblastoma cells with our proposed imaging modality, we report that neuroblastoma cells can be an important model for epileptic activity studies.
The ‘Dys-Appearing’ Body in Doris Lessing’s The Diary of a Good Neighbour and Margaret Forster’s Have the Men Had Enough?
Authors: Oró-Piqueras Maricel
Published: November 2012

If the old body is usually read as a synonym of fragility and upcoming illness, even though not the case for most elderly citizens, the reality is that the longer we live, the increased probability of being affected by different illnesses cannot be eluded or denied. In Doris Lessing’s The Diary of a Good Neighbour and Margaret Forster’s Have the Men Had Enough? the reader is invited to participate in the day-to-day routines of two aged female protagonists, as well as to empathize with their inner feelings as they go through their last life stage. In fact, their ‘dys-appearing’ bodies, marked by their respective terminal illnesses, force these characters to grow closer to those around them and to accept the help of their families and friends, despite their desire to keep their free will and independence until the very end. The analysis of the two novels within the framework of ageing studies aims to show the contradictions existing between a growing ageing society and the negative cultural connotations of old age in Western society and the need to revise them.
Conotoxins Targeting Neuronal Voltage-Gated Sodium Channel Subtypes: Potential Analgesics?
Authors: Knapp Oliver , McArthur Jeffrey R. , Adams David J.
Published: November 2012

Voltage-gated sodium channels (VGSC) are the primary mediators of electrical signal amplification and propagation in excitable cells. VGSC subtypes are diverse, with different biophysical and pharmacological properties, and varied tissue distribution. Altered VGSC expression and/or increased VGSC activity in sensory neurons is characteristic of inflammatory and neuropathic pain states. Therefore, VGSC modulators could be used in prospective analgesic compounds. VGSCs have specific binding sites for four conotoxin families: μ-, μO-, δ- and ί-conotoxins. Various studies have identified that the binding site of these peptide toxins is restricted to well-defined areas or domains. To date, only the μ- and μO-family exhibit analgesic properties in animal pain models. This review will focus on conotoxins from the μ- and μO-families that act on neuronal VGSCs. Examples of how these conotoxins target various pharmacologically important neuronal ion channels, as well as potential problems with the development of drugs from conotoxins, will be discussed.
Topography-guided Hyperopic LASIK With and Without High Irradiance Collagen Cross-linking: Initial Comparative Clinical Findings in a Contralateral Eye Study of 34 Consecutive Patients
Authors: Kanellopoulos Anastasios John , Kahn Jonathan
Published: November 2012

PURPOSE:

To evaluate the safety and efficacy of intrastromally applied collagen cross-linking (CXL) in a comparative contralateral eye study of topography-guided femtosecond laser–assisted hyperopic LASIK.

METHODS:

Thirty-four consecutive patients with hyperopia and hyperopic astigmatism elected to have bilateral topography-guided LASIK and were randomized to receive a single drop of 0.1% sodium phosphate riboflavin solution under the flap followed by 3-minute exposure of 10 mW/cm
2
ultraviolet A (UVA) light with the flap realigned in one eye (CXL group) and no intrastromal CXL in the contralateral eye (no CXL group). All eyes were treated with the WaveLight FS200 femtosecond laser and WaveLight EX500 excimer laser (Alcon Laboratories Inc). Refractive error and keratometric, topographic, and tomographic measurements were evaluated over mean follow-up of 23 months.

RESULTS:

Preoperatively, mean spherical equivalent refraction was +3.15±1.46 diopters (D) and +3.40±1.78 D with a mean cylinder of 1.20±1.18 D and 1.40±1.80 D and mean uncorrected distance visual acuity (UDVA) (decimal) of 0.1±0.26 and 0.1±0.25 in the CXL and no CXL groups, respectively. At 2 years postoperatively, mean spherical equivalent refraction was −0.20±0.56 D and +0.20±0.40 D with mean cylinder of 0.65±0.56 D and 0.76±0.72 D and mean UDVA of 0.95±0.15 and 0.85±0.23 in the CXL and no CXL groups, respectively. Eyes with CXL demonstrated a mean regression from treatment of +0.22±0.31 D, whereas eyes without CXL showed a statistically significant greater regression of +0.72±0.19 D (
P
=.0001).

CONCLUSIONS:

Topography-guided hyperopic LASIK with or without intrastromal CXL is safe and effective, with greater long-term efficacy (less regression) in eyes with CXL. Our data suggest that the regression seen with hyperopic LASIK may be related to biomechanical changes in corneal shape over time.
Transepithelial Corneal Cross-linking in Pediatric Patients: Early Results
Authors: Buzzonetti Luca , Petrocelli Gianni
Published: November 2012

PURPOSE:

To report 18-month follow-up after transepithelial cross-linking (CXL) in young patients.

METHODS:

Thirteen eyes with keratoconus were evaluated (mean patient age: 14.4±3.7 years [range: 8 to 18 years]). Corrected distance visual acuity (CDVA); spherical equivalent refraction; keratometry (K); coma, spherical aberration, and higher order aberrations (HOAs) for a 5.0-mm pupil; and thinnest point were measured preoperatively and 1, 3, 6, 9, 12, and 18 months postoperatively by Scheimplflug camera. Endothelial cell density and anterior segment optical coherence tomography were also evaluated. Paired Student
t
test was used to compare preoperative and 12- and 18-month postoperative data.
P
<.05 was considered significant.

RESULTS:

Eighteen months after treatment, CDVA improved significantly, whereas K readings and HOAs showed statistically significant worsening (
P
<.05). Spherical equivalent refraction, sphere and cylinder, coma, spherical aberration, thinnest point, and endothelial cell density did not show statistically significant changes (
P
>.05). The mean demarcation line depth was 105 μm. No side effects were observed.

CONCLUSIONS:

Transepithelial CXL appears to be a safe treatment in children. Although improved CDVA was noted 18 months after treatment, this technique does not effectively halt keratoconus progression in children compared to standard CXL.
Karst as a criterion for defining areas less suitable for agriculture
Authors: Ciglič Rok , Hrvatin Mauro , Komac Blaž , Perko Drago
Published: November 2012

The proposed European Union indicators for defining areas less suitable for agriculture in Slovenia are not entirely appropriate because taking them into account would omit some distinctly and clearly unsuitable areas–for example, Suha krajina (Dry Carniola) and Bela krajina (White Carniola)–and farmers would be unjustifiably financially harmed. In such a case, every European Union member state has the right to propose an additional indicator to reduce such discrepancies. With regard to actual natural conditions, in Slovenia especially some karst landscapes would be unjustifiably omitted, and so we have proposed a karst indicator as an additional criterion based on the distribution of karst (i.e., carbonate) rocks. Through spatial coverage of karst rocks and soils, we determined whether more reasonable and less strict application of European criteria regarding soil could be satisfactory for better results in defining areas less suitable for agriculture in Slovenia.
Ageing at home with the help of information and communication technologies
Authors: Kerbler Boštjan
Published: November 2012

Due to the ageing of the population, developed countries are facing increasing financial needs to provide suitable healthcare, social care and housing for the elderly. One of the ways in which society has responded to such issues is the idea that the elderly should be able to remain in their home environment as long as possible, where they would be capable of leading their lives as independently as possible with the best possible quality of life. This article is based on the assumption that the concept of ageing at home can be implemented with the help of information and communication technologies, which is why developed societies should integrate it into their regular healthcare and social welfare systems as soon as possible. The implementation process has proven to be very complex and as such requires careful planning, especially in Slovenia.
Mesonero, viajero por Francia y Bélgica (1840-1841)
Authors: Núñez Rey Concepción
Published: November 2012

El testimonio del viaje que Mesonero Romanos emprendió por Francia y Bélgica de 1840 a 1841, apareció publicado en el Semanario Pintoresco Español poco después de su regreso. Entre abril y agosto de ese año vertió su experiencia viajera en dieciséis artículos, que muy pronto reeditó reuniéndolos en un volumen. En estos textos descubrimos la mirada con que el autor contempla las sociedades visitadas, en la que está siempre presente España, dando lugar a constantes comparaciones y reflexiones. Para el lector habituado a sus artículos costumbristas madrileños sorprende su fascinación por el progreso técnico y el interés con que supo ver la modernidad de las sociedades visitadas.
El Artista y la ideación romántica de los géneros literarios
Authors: Ferri Coll José María
Published: November 2012

El propósito de este artículo radica en mostrar cómo a través de las páginas de El Artista se difundieron tanto los principios del nuevo movimiento, según el parecer de los miembros de su redacción, como los formatos en que tales contenidos podían divulgarse de manera más efectiva entre los jóvenes románticos.
Goya en El Artista y el Semanario Pintoresco Español
Authors: Romero Tobar Leonardo
Published: November 2012

Tanto la personalidad como la obra del pintor aragonés Francisco de Goya y Lucientes (1746-1828) han generado una copiosa e intensa reacción artística entre sus contemporáneos y los artistas posteriores hasta la actualidad. El trabajo del profesor Romero Tobar estudia la presencia de Francisco de Goya en las dos grandes revistas ilustradas de los años románticos.
Educación para la convivencia intercultural
Authors: Níkleva Dimitrinka G.
Published: November 2012

El artículo se centra en la necesidad de desarrollar la competencia comunicativa intercultural afectiva para conseguir la convivencia intercultural tan característica de nuestra sociedad actual. Presenta un breve repaso de alguna terminología básica relacionada con el tema y esboza algunas dificultades para la convivencia intercultural. En el ámbito educativo, el tratamiento de los temas multiculturales en el aula aporta distintas oportunidades para resolver este tipo de conflictos interculturales: educar en valores, usar el conflicto como aprendizaje y prevenir.
El presente estudio profundiza en los estereotipos culturales que existen en la sociedad española y en su expresión lingüistica. El objetivo es colaborar en la formación de actitudes positivas hacia la diversidad cultural.
Al final, ofrece una propuesta didáctica para la aplicación del tema estudiado a la clase de Lengua castellana y Literatura en la etapa de la Educación Secundaria Obligatoria.
Jugurtha héros national : jalons sur un itinéraire
Authors: Alexandropoulos Jacques
Published: November 2012

En créant son Jugurtha comme archétype du Numide en éternel mouvement dans un espace et un temps imprécis, Salluste pose les conditions d’une récupération « nationale » officielle du héros après l’indépendance algérienne. Cela suppose néanmoins des relais, dont celui de Michelet qui fait de Jugurtha un champion de l’indépendance berbère à l’époque où les circonstances de la conquête de l’Algérie tendent à rapprocher Jugurtha de son double contemporain Abdelkader. L’analogie permet alors un basculement progressif du personnage de Jugurtha. Pour le colonisateur, il représente l’éternel Numide enfin soumis, comme Abdelkader. Le poète Jean Amrouche, écartelé entre sa culture berbère algérienne et celle de la France, intériorise à la fois le portrait charge de l’éternel Numide et son potentiel de révolte en un dernier avertissement au colonisateur (L’éternel Jugurtha, 1943). La prégnance de la réception « occidentale » de l’Antiquité apparaît ici dans toute sa force. Puis le nationalisme algérien de l’indépendance se réfère dans les chartes nationales algériennes successives à un Jugurtha désormais délesté des défauts numides, ne gardant de ses origines sallustéennes qu’un cadre événementiel emblématique d’un combat contre l’éternel « colonisateur » et ses alliés, comme Bocchus « le Marocain ».
Charles Garnier et l’histoire du théâtre. À propos du gala de l’Opéra du 26 janvier 1886
Authors: Martin Marie Saint
Published: November 2012

La représentation de gala du 26 janvier 1886, à l’Opéra, s’inscrit dans une visée de reconstitution archéologique. Cette ambition éclaire l’histoire de la réception du théâtre antique au xixe siècle. La question des masques, en particulier, cristallise les interrogations de la critique sur les nouvelles pratiques scéniques attachées à cette visée archéologique. Les problèmes que soulève cette tentative sont déjà au cœur des commentaires contemporains : la représentation de Garnier met en valeur les apories du système de reconstitution adopté, puis abandonné par le xixe siècle antiquisant.
Évaluation, motivation et formation
Authors: Doucet Patrick
Published: November 2012

Dans le cadre d’un compte-rendu de deux expériences menées à l’Université de Poitiers (Faculté des Sciences, 1991-93 et 1993-95) sur des échantillons respectivement de 100 et de 44 étudiants, cet article vise à démontrer une relation de causalité entre une pratique évaluative présentée par anticipation sous forme de pré-test et l’apprentissage, postulant ainsi l’existence d’un effet de reflux positif qu’un test crédible peut avoir. Cet effet de reflux est souvent mentionné dans la recherche comme allant de soi, mais non mesuré. On insiste sur la notion de crédibilité des pratiques évaluatives aux yeux des apprenants : en l’occurrence, la compétence de communication est évaluée à l’aide d’un test d’interaction orale en binôme. On montre comment il est possible de créer des conditions pour que l’évaluation, conçue au départ comme ressort de la motivation, puisse en fin de compte n’être qu’une étape sur la voie d’une motivation intrinsèque, permettant la prise en charge de son apprentissage par l’apprenant lui-même.
Ex Vivo Enzymatic Treatment of Aged CD4 T Cells Restores Cognate T Cell Helper Function and Enhances Antibody Production in Mice
Authors: Perkey Eric , Miller Richard A. , Garcia Gonzalo G.
Published: November 2012

Previous in vitro studies showed that CD4 T cells from old mice have defects in TCR signaling, immune synapse formation, activation, and proliferation. We reported that removing a specific set of surface glycoproteins by ex vivo treatment with O-sialoglycoprotein endopeptidase (OSGE) can reverse many aspects of the age-related decline in CD4 T cell function. However, the specific mechanism by which this process occurs remains unclear, and it is unknown whether this enzymatic treatment can also restore important aspects of adaptive immunity in vivo. By using an in vivo model of the immune response based on adoptive transfer of CD4 T cells from pigeon cytochrome C–specific transgenic H-2(k/k) TCR-Vα11Vβ3 CD4+ mice to syngeneic hosts, we demonstrate that aging diminishes CD28 costimulatory signals in CD4 T cells. These age-associated defects include changes in phosphorylation of AKT and expression of glucose transporter type I, inducible T cell costimulatory molecule, and CD40L, suggesting that the lack of CD28 costimulation contributes to age-dependent loss of CD4 function. All of these deficits can be reversed by ex vivo OSGE treatment. Blocking B7–CD28 interactions on T cells prevents OSGE-mediated restoration of T cell function, suggesting that changes in surface glycosylation, including CD28, may be responsible for the age-related costimulation decline. Finally, we show that the age-related decline in CD4 cognate helper function for IgG production and long-term humoral immunity can also be restored by OSGE treatment of CD4 T cells prior to adoptive transfer.
Lymphopenia-Driven Homeostatic Regulation of Naive T Cells in Elderly and Thymectomized Young Adults
Authors: Sauce Delphine , Larsen Martin , Fastenackels Solène , Roux Antoine , Gorochov Guy , Katlama Christine , Sidi Daniel , Sibony-Prat Joyce , Appay Victor
Published: November 2012

Reduced thymopoiesis and continuous mobilization of naive T cells into the effector–memory pool can lead to severe alterations of the naive T cell compartment. However, maintenance of the naive T cell population is essential to mount effective immune responses. Evidence of homeostatic regulation of naive T cells is currently debated in animal models. In humans, the situation remains unresolved, in particular with advanced age. In this study, we analyzed the CD4+ and CD8+ naive T cell compartments from elderly, young adults thymectomized during early childhood, and HIV-1–infected patients, which are characterized by T lymphocytopenia. We show a direct association between increased turnover and decreased frequency of naive T cells. Moreover, the IL-7–induced pathway was fully functional in naive T cells from elderly and young adults thymectomized during early childhood, who are characterized by elevated IL-7 plasma levels. Our findings support the establishment of homeostatic regulation of naive T cell proliferation in humans. This regulation is particularly active in lymphopenic hosts, such as elderly and thymectomized patients.
IPS-1 Signaling Has a Nonredundant Role in Mediating Antiviral Responses and the Clearance of Respiratory Syncytial Virus
Authors: Demoor Tine , Petersen Bryan C. , Morris Susan , Mukherjee Sumanta , Ptaschinski Catherine , De Almeida Nagata Denise E. , Kawai Taro , Ito Toshihiro , Akira Shizuo , Kunkel Steven L. , Schaller Matthew A. , Lukacs Nicholas W.
Published: November 2012

The cytosolic RNA helicases melanoma differentiation–associated gene 5 and retinoic acid–inducible gene-I and their adaptor IFN-β promoter stimulator (IPS-1) have been implicated in the recognition of viral RNA and the production of type I IFN. Complementing the endosomal TLR, melanoma differentiation–associated gene 5, and retinoic acid–inducible gene-I provides alternative mechanisms for viral detection in cells with reduced phagocytosis or autophagy. The infection route of respiratory syncytial virus (RSV)—via fusion of virus particles with the cell membrane—points to IPS-1 signaling as the pathway of choice for downstream antiviral responses. In the current study, viral clearance and inflammation resolution were indeed strongly affected by the absence of an initial IPS-1–mediated IFN-β response. Despite the blunted inflammatory response in IPS-1–deficient alveolar epithelial cells, pulmonary macrophages, and CD11b+ dendritic cells (DC), the lungs of RSV-infected IPS-1–knockout mice showed augmented recruitment of inflammatory neutrophils, monocytes, and DC. Interestingly, pulmonary CD103+ DC could functionally compensate for IPS-1 deficiency with the upregulation of certain inflammatory cytokines and chemokines, possibly via TLR3 and TLR7 signaling. The increased inflammation and reduced viral clearance in IPS-1–knockout mice was accompanied by increased T cell activation and IFN-γ production. Experiments with bone marrow chimeras indicated that RSV-induced lung pathology was most severe when IPS-1 expression was lacking in both immune and nonimmune cell populations. Similarly, viral clearance was rescued upon restored IPS-1 signaling in either the nonimmune or the immune compartment. These data support a nonredundant function for IPS-1 in controlling RSV-induced inflammation and viral replication.
Suppression of Vaccine Immunity by Inflammatory Monocytes
Authors: Mitchell Leah A. , Henderson Angela J. , Dow Steven W.
Published: November 2012

Vaccine adjuvant-induced inflammation augments vaccine immunity in part by recruiting APCs to vaccine draining lymph nodes (LNs). However, the role of one APC subtype, inflammatory monocytes, in regulating vaccine immunity in healthy animals has not been fully examined in detail. Therefore, vaccine-mediated monocyte recruitment and subsequent immune responses were investigated using murine vaccination models and in vitro assays. Recruitment of inflammatory monocytes to vaccine draining LNs was rapid and mediated primarily by local production of MCP-1, as revealed by studies in MCP-1−/− mice. Interrupting monocyte recruitment to LNs by either transient monocyte depletion or monocyte migration blockade led to marked amplification of both cellular and humoral immune responses to vaccination. These results were most consistent with the idea that rapidly mobilized inflammatory monocytes were actually suppressing vaccine responses. The suppressive nature of vaccine-elicited monocytes was confirmed using in vitro cocultures of murine monocytes and T cells. Furthermore, it was determined that inflammatory monocytes suppressed T cell responses by sequestering cysteine, as cysteine supplementation in vitro and in vivo appreciably augmented vaccine responses. These findings indicated, therefore, that vaccination-elicited inflammation, although necessary for effective immunity, also generated potent counter-regulatory immune responses that were mediated primarily by inflammatory monocytes. Therefore, interrupting monocyte-mediated vaccine counterregulatory responses may serve as an effective new strategy for broadly amplifying vaccine immunity.
Promoting transformative learning: Writing a reflective journal in Natural Sciences.
Authors: Du Toit Erna R.
Published: November 2012

This article aims to show that writing a reflective journal in Natural Science can transform the perspectives and thoughts of teacher students and/or promote learning. The study mediates for the use of a reflective journal as an instrument to give meaning to the learning environment from various perspectives by learning in practice. A qualitative research method is used to analyse the entries in a journal on the basis of specific indicators. The findings indicate that the majority of students were positive following the practical experience, and some students showed other perspectives on account of their experience.
Analysis and Confirmation of 1,3-DMAA and 1,4-DMAA in Geranium Plants Using High Performance Liquid Chromatography with Tandem Mass Spectrometry at ng/g Concentrations
Authors: Fleming Heather L. , Ranaivo Patricia L. , Simone Paul S.
Published: November 2012

1,3-Dimethylamylamine (1,3-DMAA) is a stimulant commercially sold in a variety of dietary supplements as a chemical species derived from geranium plants (Pelargonium graveolens). Whether 1,3-DMAA naturally occurs in geranium plants or other dietary ingredients, it has important regulatory and commercial ramifications. However, the analysis of 1,3-DMAA in geranium plants is not trivial due to low concentrations and a complex environmental matrix, requiring high selectivity and sensitivity. An extraction method combined with high performance liquid chromatography and tandem mass spectrometry is used to determine 1,3-DMAA and 1,4-dimethylamylamine (1,4-DMAA) concentrations in geranium plants with both external calibration and standard addition method. Samples from the Changzhou, Kunming, and Guiyang regions of China during both winter and summer were analyzed for 1,3-DMAA and 1,4-DMAA. The diastereomer ratios of the 1,3-DMAA stereoisomers of a racemic standard and the extracted plant were also quantified.
A multi-model study of impacts of climate change on surface ozone in Europe
Authors: Langner J. , Engardt M. , Baklanov A. , Christensen J. H. , Gauss M. , Geels C. , Hedegaard G. B. , Nuterman R. , Simpson D. , Soares J. , Sofiev M. , Wind P. , Zakey A.
Published: November 2012

Abstract. The impact of climate change on surface ozone over Europe was studied using four offline regional chemistry transport models (CTMs) and one online regional integrated climate-chemistry model (CCM), driven by the same global projection of future climate under the SRES A1B scenario. Anthropogenic emissions of ozone precursors from RCP4.5 for year 2000 were used for simulations of both present and future periods in order to isolate the impact of climate change and to assess the robustness of the results across the different models. The sensitivity of the simulated surface ozone to changes in climate between the periods 2000–2009 and 2040–2049 differs by a factor of two between the models, but the general pattern of change with an increase in southern Europe is similar across different models. Emissions of isoprene differ substantially between different CTMs ranging from 1.6 to 8.0 Tg yr−1 for the current climate, partly due to differences in horizontal resolution of meteorological input data. Also the simulated change in total isoprene emissions varies substantially across models explaining part of the different climate response on surface ozone. Ensemble mean changes in summer mean ozone and mean of daily maximum ozone are close to 1 ppb(v) in parts of the land area in southern Europe. Corresponding changes of 95-percentiles of hourly ozone are close to 2 ppb(v) in the same region. In northern Europe ensemble mean for mean and daily maximum show negative changes while there are no negative changes for the higher percentiles indicating that climate impacts on O3 could be especially important in connection with extreme summer events.
Amino acids in Arctic aerosols
Authors: Scalabrin E. , Zangrando R. , Barbaro E. , Kehrwald N. M. , Gabrieli J. , Barbante C. , Gambaro A.
Published: November 2012

Abstract. Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs) in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS) to analyze 20 amino acids and quantify compounds at fmol m−3 levels. Mean total FAA concentration was 1070 fmol m−3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45–60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m−3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (< 0.49 μm) and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanic emissions.
Ambient black carbon particle hygroscopic properties controlled by mixing state and composition
Authors: Liu D. , Allan J. , Whitehead J. , Young D. , Flynn M. , Coe H. , McFiggans G. , Fleming Z. , Bandy B.
Published: November 2012

Abstract. The wet removal of black carbon aerosol (BC) in the atmosphere is a crucial factor in determining its atmospheric lifetime and thereby the vertical and horizontal distributions, dispersion on local and regional scales, and the direct, semi-direct and indirect radiative forcing effects. The in-cloud scavenging and wet deposition rate of freshly emitted hydrophobic BC will be increased on acquisition of more-hydrophilic components by coagulation or coating processes. The lifetime of BC is still subject to considerable uncertainty for most of the model inputs, which is largely due to the insufficient constraints on the BC hydrophobic-to-hydrophilic conversion process from observational field data. This study was conducted at a site along UK North Norfolk coastline, where the BC particles were transported from different regions within Western Europe. A hygroscopicity tandem differential mobility analyser (HTDMA) was coupled with a single particle soot photometer (SP2) to measure the hygroscopic properties of BC particles and associated mixing state in real time. In addition, a Soot Particle AMS (SP-AMS) measured the chemical compositions of additional material associated with BC particles. The ensemble of BC particles persistently contained a less-hygroscopic mode at a growth factor (gf) of around 1.05 at 90% RH (dry diameter 163 nm). Importantly, a more-hygroscopic mode of BC particles was observed throughout the experiment, the gf of these BC particles extended up to ~1.4–1.6 with the minimum between this and the less hygroscopic mode at a gf ~1.25, or equivalent effective hygroscopicity parameter κ = ~0.1. The gf of BC particles (gfBC) was highly influenced by the composition of associated soluble material: increases of gfBC were associated with secondary inorganic components, and these increases were more pronounced when ammonium nitrate was in the BC particles; however the presence of secondary organic matter suppressed the gfBC below that of pure inorganics. The Zdanovskii-Stokes-Robinson (ZSR) mixing rule captures the hygroscopicity contributions from different compositions within ±30% compared to the measured results, however is subject to uncertainty due to the complex morphology of BC component and potential artefacts associated with semivolatile particles measured with the HTDMA. This study provides detailed insights on BC hygroscopicity associated with its mixing state, and the results will importantly constrain the microphysical mixing schemes of BC as used by a variety of high level models. In particular, this provides direct evidence to highlight the need to consider ammonium nitrate ageing of BC particles because this will result in particles becoming hydrophilic on much shorter timescales than for sulphate formation, which is often the only mechanism considered.
What controls the spatio-temporal distribution of D-excess and 17O-excess in precipitation? A general circulation model study
Authors: Risi C. , Landais A. , Winkler R. , Vimeux F.
Published: November 2012

Abstract. Combined measurements of the H218O and HDO isotopic ratios in precipitation, leading to second-order parameter D-excess, have provided additional constraints on past climates compared to the H218O isotopic ratio alone. More recently, measurements of H217O have led to another second-order parameter: 17O-excess. Recent studies suggest that 17O-excess in polar ice may provide information on evaporative conditions at the moisture source. However, the processes controlling the spatio-temporal distribution of 17O-excess are still far from being fully understood. We use the isotopic general circulation model LMDZ to better understand what controls D-excess and 17O-excess in precipitation at present-day (PD) and during the last glacial maximum (LGM). The simulation of D-excess and 17O-excess is evaluated against measurements in meteoric water, water vapor and polar ice cores. A set of sensitivity tests and diagnostics are used to quantify the relative effects of evaporative conditions (sea surface temperature and relative humidity), Rayleigh distillation, precipitation re-evaporation and supersaturation during condensation at low temperature. Simulations suggest that in the tropics convective processes and rain re-evaporation are important controls on D-excess and 17O-excess. In higher latitudes, the effect of distillation, transport and mixing balance the effect of supersaturation. Since these terms are very large and near cancellation, results for both PD and LGM are very sensitive to the supersaturation function. The lower D-excess and 17O-excess at LGM simulated at LGM are dominated by the supersaturation effect. Evaporative conditions had previously been suggested to be key controling factors of D-excess and 17O-excess. In LMDZ, evaporative conditions are key in explaining the PD latitudinal and seasonal distributions, but play little role for 17O-excess and for LGM variations. However, the LMDZ may underestimate this role. More generally, some shortcomings in the simulation of 17O-excess by LMDZ suggest that GCMs are not yet the perfect tool to quantify with confidence all processes controlling 17O-excess.
Hydrologic system complexity and nonlinear dynamic concepts for a catchment classification framework
Authors: Sivakumar B. , Singh V. P.
Published: November 2012

Abstract. The absence of a generic modeling framework in hydrology has long been recognized. With our current practice of developing more and more complex models for specific individual situations, there is an increasing emphasis and urgency on this issue. There have been some attempts to provide guidelines for a catchment classification framework, but research in this area is still in a state of infancy. To move forward on this classification framework, identification of an appropriate basis and development of a suitable methodology for its representation are vital. The present study argues that hydrologic system complexity is an appropriate basis for this classification framework and nonlinear dynamic concepts constitute a suitable methodology. The study employs a popular nonlinear dynamic method for identification of the level of complexity of streamflow and for its classification. The correlation dimension method, which has its base on data reconstruction and nearest neighbor concepts, is applied to monthly streamflow time series from a large network of 117 gaging stations across 11 states in the western United States (US). The dimensionality of the time series forms the basis for identification of system complexity and, accordingly, streamflows are classified into four major categories: low-dimensional, medium-dimensional, high-dimensional, and unidentifiable. The dimension estimates show some "homogeneity" in flow complexity within certain regions of the western US, but there are also strong exceptions.
Antimicrobial Activity of Nanocomposite Zirconium Nitride/Silver Coatings to Combat External Bone Fixation Pin Infections
Authors: Wickens David J. , West Glen , Kelly Peter J. , Verran Joanna , Lynch Stephen , Whitehead Kathryn A.
Published: November 2012

During external fixation, temporary implants are used to penetrate the skin, muscle and bone to support severely fractured bones. This creates a biologically critical interface at the site of entry, which potentially allows a risk of infection. The aim of this study, therefore, was to investigate potential antimicrobial nanocomposites to combat infection.

Magnetron sputtering was used to produce zirconium nitride/silver nanocomposite coatings, which were prepared at two different silver concentrations of 15.5 at.% and 29.8 at.%. These coatings were characterized for morphology, chemical composition, and antimicrobial activity in comparison to pure zirconium nitride and stainless steel. Staphylococcus aureus and Staphylococcus epidermidis were used as in vitro test organisms in a range of antimicrobial assays; retention of the bacteria on the surfaces and their survival using LiveDead™ staining; the use of a metabolic redox dye to indicate a contact kill and zone of inhibition assays to indicate leaching of inhibitory silver ions. Antimicrobial tests demonstrated a significant kill when the bacterial cells came in contact with the coatings containing silver at both 15.5 at.% and 29.8 at.%. No inhibitory leaching from the surfaces occurred. These surfaces demonstrate potential for use as antimicrobial fixation pin coatings.
Historical ethnobotanical review of wild edible plants of Estonia (1770s–1960s)
Authors: Kalle Raivo , Sõukand Renata
Published: November 2012

This paper is a historical ethnobotanical review of wild plants used by the residents of present day Estonia during the 1770s–1960s. Twenty two sources addressing historical ethnographical accounts of the use of wild food plants were analysed. The use of 147 taxa of vascular plants (over 6% of Estonian vascular flora) and two lichens has been recorded. Although the data does not allow for reliable determination of the frequency of use of specific taxa among the population, general conclusions on the preferences for specific dishes made of wild food plants can be made. While the category of snacks covers the largest proportion of species used, a substantial addition to food rations was provided by bread ingredients (used predominantly in famine times), green vegetables used for making soup, and later jams and other dishes of wild berries. Also beverages (tea and coffee substitutes), beer and beer-like drinks were widely made, and the saps of several tree species were consumed in fresh and fermented form. The most important species, according to the criterion of diversity of use, were Carum carvi, Urtica dioica, and the wild berries Vaccinium vitis-idaea and Vaccinium myrtillus.
Design of a Scalable Modular Production System for a Two-Stage Food Service Franchise System
Authors: Matt D. T. , Rauch E.
Published: November 2012

The geographically distributed production of fresh food poses unique challenges to the production system design because of their stringent industry and logistics requirements. The purpose of this research is to examine the case of a European fresh food manufacturer's approach to introduce a scalable modular production concept for an international two-stage gastronomy franchise system in order to identify best practice guidelines and to derive a framework for the design of distributed production systems that perform in a highly dynamic environment. The design framework was developed by creating a theoretical model through literature review and the thorough analysis of an industrial case. Information was collected through multiple site visits, workshops and semi-structured interviews with the company's key staff of the project, as well as examination of relevant company documentations. By means of a scenario for the Central European market, the model was reviewed in terms of its development potential and finally approved for implementation. However, research through case survey requires further empirical investigation to fully establish this approach as a valid and reliable design tool.
Adaptive Tracking and Obstacle Avoidance Control for Mobile Robots with Unknown Sliding
Authors: Cui Mingyue , Sun Dihua , Liu Weining , Zhao Min , Liao Xiaoyong
Published: November 2012

An adaptive control approach is proposed for trajectory tracking and obstacle avoidance for mobile robots with consideration given to unknown sliding. A kinematic model of mobile robots is established in this paper, in which both longitudinal and lateral sliding are considered and processed as three time-varying parameters. A sliding model observer is introduced to estimate the sliding parameters online. A stable tracking control law for this nonholonomic system is proposed to compensate the unknown sliding effect. From Lyapunov-stability analysis, it is proved, regardless of unknown sliding, that tracking errors of the controlled closed-loop system are asymptotically stable, the tracking errors converge to zero outside the obstacle detection region and obstacle avoidance is guaranteed inside the obstacle detection region. The efficiency and robustness of the proposed control system are verified by simulation results.
A Visual Lifting Approach for Dynamic Bipedal Walking
Authors: Song Wei , Minami Mamoru , Zhang Yanan
Published: November 2012

Although many papers have been published on visual tracking and visual servoing for vision-based robotics, there are only a few research projects studying using vision to improve standing and walking stabilization for legged robots. In this paper, we proposition a “Visual Lifting Bipedal Walking” strategy, which uses visually measured information to control the robot to keep a desired head-top's position/orientation in order to help prevent the robot from falling into unstable gaits, such as falling down on the ground or dangerous foot-slipping caused by gravity, unexpected coupling dynamics, etc.
Kinematic Analysis of a Hybrid Structure
Authors: Duan Q.J. , Du J.L. , Duan X.C.
Published: November 2012

This paper presents a kinematic analysis and simulation of a hybrid structure applied to the new design cable-suspended feed structure (CSFS) for the next generation of large spherical radio telescopes. First, considering the requirement that feeds should be tilted from 40° to 60° and that the tracking precision in steady state is 4mm, a novel design of the feed supporting structure including a cable-cabin structure, an AB axis structure and a Stewart platform is performed. Next, kinematic analysis and the simulation of the CSFS are done. Simulations have been developed in combination with the 50m CSFS model, which demonstrate the effectiveness and feasibility of the proposed three-level cable-suspended feed system.