Biological Routes to Gold Nanoplates

Much effort has been devoted to the synthesis of gold nanoparticles with different shapes, including the zero-dimensional nanospheres, one dimensional nanorods, and two-dimensional nanoplates. Compared to zero or one dimensional nanostructures, the synthesis of two-dimensional nanostructures in high yield has always been more involved, often requiring complex and time-consuming steps such as morphology transformation from the nanospheres, or the seeded growth process. Herein we report a high yield method for gold nanoplate synthesis using the extract of unicellular green alga Chlorella vulgaris, which can be carried out under ambient conditions. More than 90% of the total nanoparticle population is of the platelet morphology, surpassing the previously reported value of 45%. The control of the anisotropic growth of different planes; as well as the lateral size, has also been partially optimized.

Binding studies of a protonated dioxatetraazamacrocycle with carboxylate substrates

The tetraprotonated form of the dioxatetraazamacrocycle, 6,19-dioxa-3,9,16,22-tetraaza[22.2.2.2(11,14)]-triaconta-1(26),11,13,24, 27,29-hexaene, (H4L1)(4+), was used as the receptor for binding studies with carboxylate anionic substrates of different shapes, sizes, and charges [succinate (suc(2-)), cyclo- hexanetricarboxylate (cta(3-)), phthalate (ph(2-)), isophthalate (iph(2-)), terephthalate (tph(2-)), and benezenetricarboxylate (btc(3-))]. Association constants were determined by potentiometry in aqueous solution at 298.2 K and 0.10 M KCl and by H-1 NMR titration in D2O. The strongest association was found for the btc3- anion at 5-7 pH region. From both techniques it was possible to establish the binding preference trend of the receptor for the different substrates, and the H-1 NMR spectroscopy gave important suggestions about the type of interactions between partners and the location of the substrates in the supramolecular entities formed. The effective binding constants at pH 6 follow the order: btc(3-)>iph(2-)>cta(3-) =ph(2-)>tph(2-)>suc(2-). All the studies suggest that the anionic substrates bind to the receptor via N-H center dot center dot center dot O = C hydrogen bonds and electrostatic interactions, and the aromatic substrates can also establish pi-pi stacking interactions. The crystal structures of (H4L1)(4+) and its supramolecular assemblies with ph(2-) and tph(2-) were determined by X-ray diffraction. The last two structures showed that the association process in solid state occurs via multiple N-H center dot center dot center dot O = C hydrogen bonds with the anionic substrate located outside the macrocyclic cavity of the receptor. Molecular dynamics simulations carried out for the association of (H4L1)(4+) with tph(2-) and btC(3-) in water solution established at atomic level the existence of all interactions suggested by the experimental studies, which act cooperatively in the binding process. Furthermore, the binding free energies were estimated and the values are in agreement with the experimental ones, indicating that the binding of these two anionic substrates occurs into the receptor cavity. However, the tph(2-) has also propensity to leave the macrocyclic cavity and its molecular recognition can also happen at the top of the receptor. (C) 2008 Elsevier Ltd. All rights reserved.

Alcantarea (Bromeliaceae) leaf anatomical characterization and its systematic implications

Alcantarea (Bromeliaceae) has 26 species that are endemic to eastern Brazil, occurring mainly on gneiss-granitic rock outcrops (`inselbergs`). Alcantarea has great ornamental potential and several species are cultivated in gardens. Limited data is available in the literature regarding the leaf anatomical features of the genus, though it has been shown that it may provide valuable information for characterizing of Bromeliaceae taxa. In the present work, we employed leaf anatomy to better characterize the genus and understand its radiation into harsh environments, such as inselbergs. We also searched for characteristics potentially useful in phylogenetic analyses and in delimiting Alcantarea and Vriesea. The anatomical features of the leaves, observed for various Alcantarea species, are in accordance with the general pattern shown by other Bromeliaceae members. However, some features are notable for their importance for sustaining life on rock outcrops, such as: small epidermal thick-walled cells, uneven sinuous epidermal walls, hypodermis often differentiated into lignified layers with thick-walled cells, aquiferous hypodermis bearing collapsible cells, and the presence of well developed epicuticular stratum. Alcantarea leaves tend to show different shapes in the spongy parenchyma, and have chlorenchymatous palisade parenchyma arranged in more well-defined arches, when compared to Vriesea species from the same habitat.

Inflated beta distributions

This paper considers the issue of modeling fractional data observed on [0,1), (0,1] or [0,1]. Mixed continuous-discrete distributions are proposed. The beta distribution is used to describe the continuous component of the model since its density can have quite different shapes depending on the values of the two parameters that index the distribution. Properties of the proposed distributions are examined. Also, estimation based on maximum likelihood and conditional moments is discussed. Finally, practical applications that employ real data are presented.

Asymmetrical awnings : a way to increase daylight in buildings without increasing the overheating

Different shapes of asymmetric awnings for east and west windows are investigated mathematically as well as by measurement in a model. A box with 90 cm side and a 30x30 cm window was placed outdoor in overcast weather and the daylight factor was measured at the bottom of the box when the window was unshaded or equipped with different awnings. The average daylight factor in the box decreased from 4.6% for the unshaded window to 1.0% when a full awning was used. With “the best” asymmetrical awning, the average daylight factor was 80% larger than with the full awing. Using Dutch climate, calculation of the energy from direct radiation transmitted through the window during the cooling season showed that this was decreased from 100% as an annual mean for the unshaded window down 22% with a full awing. With “the best” asymmetrical awning, 26% of the energy was transmitted. Calculation of the indoor temperature in a hypothetical row house in Netherlands show that the use of either normal or asymmetrical awnings considerable decrease the indoor temperature during the hot season. Therefore the use of asymmetrical awnings for east or west faced windows considerable can increase the daylight in buildings, with almost no change in overheating, compared to if traditional awnings are used.

Flexibilitetens frammarsch, en studie om den intermittenta anställningen

Flexible working conditions is used extensively in organizations today as a way to create flexibility for the employer. Recently we’ve been reading in the newspapers that this approach is a growing problem and the EU has warned Sweden twice that abuse of these forms of employment must be stopped. The Government has recently submitted a proposed rule change to reduce the possibility of stacking one temporary contract after another. Borlänge kommun makes themselves more flexible with the intermittent employments. This study aims to examine why infrequent employments, such as the intermittent employment is used and preferred by Borlänge kommun and how it’s perceived by affected employees in the organization. The questions related, besides why the intermittent employment is used by the organization and how its perceived by those involved, also includes the management of intermittent employment and how the organization is handling work contracts. The background information on the employment law implications gives the reader an insight into how the regulatory framework works surrounding the topic. The theory section highlights the main theories about flexibility and its different shapes and perspectives. For the study a qualitative approach is used. A case study with semi-structured interviews was performed. The respondents were employees involved in the staffing of intermittent employees and also members of the staff with an intermittent employment. The results show that the employment and contracts is correctly handled by labour law regulations. This study shows that Borlänge kommun uses intermittent employments extensively, with its 1 320 intermittently employees. If this is abuse, or not, is not clear from the result. The authors discuss, however, if that is the case. The intermittent employment is used mainly because of the great needs. This is because society is changing and the average age is increasing, both by those using the services and the employees. All respondents perceive the intermittent employment as most flexible for the employees. Respondents working in the staffing department say that they are not flexible enough. The intermittent employees’ working today does not cover the great need. Borlänge kommun think that the flexibility should benefit them more and is currently trying to become more flexible. The employees were generally satisfied with their work situation. Some tendencies of insecurity and uncertainty could be inferred from the intermittent employees answers. The author’s conclusions are that flexibility and the intermittent employment contracts mainly benefit the employer and the employees who actively choose this type of work, such as students. This kind of employment affects, however, the society and those who need a secure lifestyle. The necessary permanent contracts are becoming fewer and replaced by precarious and flexible employment conditions.

Distance teacher education – some experiences from Dalarna University, SwedenPaper presented at the 33rd Annual ATEE Conference Brussels, Belgium, 23rd – 27th August 2008

Distance teaching is now-a-days used in different shapes. However, it is something different from traditional campus organised education as it systematically uses Information Communication Technology (ICT) as a key element. When the distance teacher education started in Sweden many teacher educators doubted the wisdom of this. They expressed that the educational process to become a teacher would be deteriorated. For instance, they feared for high drop out rates and difficulties to examine in a proper way. The Swedish National Agency for Higher Education has recently edited a report that showed that this form of teacher education was well adapted to the labour market, but the possibilities for the teacher students to shape their education were relatively limited. However, we still know quite little about the effects of this way to educate teacher students. This paper explores the possibility of using distance teacher education.In a case study 20 students, who were the first to finish a complete a distance teacher education at Högskolan Dalarna, were asked in a questionnaire how they had apprehended their education. We also interviewed four of these students, as well as five teacher educators.One of our findings were that the distance teacher education reached new target groups, who not had been able to participate in university studies if it not had been offered in this form. Especially, this was valid for the middle-aged women, living a long distance away from a university, with social responsibilities for children or old parents. Other findings were that these students in general were target oriented and ambitious, wrote more than the campus students and developed that kind of skill better. Marratech, an ICT system for small groups, e-mail and chat were used for the communication. Marratech was considered to permit free and spontaneous communication, both of the teacher educators and the students. Initially the teacher educators were sceptical to distance teacher education, but afterwards they were surprised of how well it had worked. They declared that they had better and nearer contact with their students and more control over the students´ performance, but some parts of the teacher education were better suitable for campus education, for example, power of creating characters. Distance teacher education was considered time consuming and demanded much activity from the teacher educators as the students wanted rapid responses. This study indicates that distance teacher education works well for mature individuals with high motivation. However, it demands more time from the teacher educators, but it gives in general good results. Still, there are pedagogical challenges to overcome. Maybe we should reflect on a mix of distance teacher education and campus based teacher education, instead of separated ways of accomplishing teacher education?

Scriptural Archeology: Excavating the Presence of Women in the Torah

Women's roles in religious history have been traditionally described in terms of their relation and value to men. The normative religious texts provide an androcentric perspective on the gender relationships within the early community, the growth of Judaism in "Jacob's House" and the monotheistic worship of God. Yet these literary representations omit an entire half of the experience of the Jewish community: the perspective and participation of women. As Judith Plaskow argues extensively in Standing Again at Sinai, women are defined not in her own terms or in her own voice, but by her relationship and value to men through the androcentric vocabulary of the Torah. This statement is textually illustrated by the authorial and editorial presentation of women and their place in ancient Israelite society in the Torah. As Judaism grew increasingly androcentric in its leadership, women were increasingly reduced to marginal figures in the community by authorial and editorial revisions. Yet the participation of women of ancient Israel is not lost. Instead, the presence of women is buried beneath the androcentric presentation of the early Judaic community, waiting to be excavated by historical and scriptural examination. The retelling of the past is influenced by the present; memory is not static but takes on different shapes depending on the focus of concentration. However, tradition greatly influences the interpretation of religious history as well. In the book of Genesis, the literature emphasizes the divine appointment of male figures such as Abraham the father of the covenant and Jacob who is renamed and claimed by God as "Israel," placing them at the center of Jewish history. As a result, the other figures in these biblical narratives are described in relation to the patriarchs, those male bearers of the covenant, by their service or their value to him. Women are at the bottom of this hierarchy. Although female figures of exceptional quality are noted in later chronicles, such as Ruth, Deborah and Miriam, it is the very nature of their exception that highlights the androcentric editorial focus of the Torah. I agree with Peggy Day, whose own scriptural examination in Gender and Difference in Ancient Israel, makes the important distinction between the literary representation and the reality of ancient Israelite culture: they are not coextensive nor equivalent. Although the text represents the culture of ancient Israel as male dominated from the time of Abraham, this presentation omits the perspective of half of the population-the women. By beginning at the point of realization that women did exist and were active in their culture, and placing aside the androcentric perspective of the text and its editors, the reality of women's place in ancient Israel may be determined. Through this new perspective, the women of the Torah will emerge as the archetypes of strength, leadership and spiritual insight to provide Jewish women of the present with female, ancestral role models and a foundation for their gender's heritage, a more complete understanding of the partial record of Jewish history recorded in the Torah. Those stories that appear as the exception of women's presence will unveil an exceptional presence. As Tamar Frankiel eloquently states in The Voice of Sarah, "the women we call our 'Mothers'-Sarah, Rivkah (Rebekah), Rachel, and Leah-are not merely mothers, any more than the 'Fathers'-Abraham, Isaac and Jacob-are merely fathers "(Frankiel 5).

Integrating open innovation in the social innovation process: an exploratory study

Inovação tem se tornado um fenômeno cada vez mais complexo e dinâmico, com a mudança de um paradigma focado na inovação industrial, onde a inovação acontecia no produto ou no processo de fabricação, para outro baseado no conhecimento, muito mais amplo. Além disso, o conhecimento e a competência técnica não são mais considerados como um monopólio do departamento de pesquisa e desenvolvimento. Isto trouxe mudanças nas práticas de inovação, que se tornaram mais abertas e levaram as empresas a interagir cada vez mais com o seu ambiente. Por outro lado, a inovação tecnológica, cujo primeiro objetivo é de criar valor para a empresa, tem experimentado alguns limites para resolver problemas sociais, como o aquecimento global. As novas tecnologias têm a capacidade de melhorar a qualidade de vida de muita gente, mas não é suficiente. É nesse contexto que surge outro tipo de inovação, cujo objetivo é de maximizar o impacto positivo na sociedade: a inovação social. Estes dois paradigmas de inovação, mais adequados aos desafios atuais, têm alguns pontos em comum na sua integração com o ambiente externo: a sociedade e outros atores da inovação. No entanto, praticamente não existem estudos integrando inovação aberta e inovação social. Este trabalho estuda a integração destes dois modelos a partir de uma pesquisa exploratória, realizando entrevistas em profundidade com 11 dirigentes de organizações sociais. As iniciativas sociais parecem atrair mais organizações externas para colaborar do que empresas com fins lucrativos, já que são mais altruístas. Parecem integrar essas pessoas e procurar por mais ajuda, especialmente no momento de escalar o negócio. Ainda que algumas organizações têm como prioridade institucionalizar a inovação aberta, outras veem isto como secundário ou simplesmente não sabem como fazer. Isto resulta em uma colaboração mais informal, que não é focada em atividades de pesquisa e desenvolvimento, prática ausente nas empresas da nossa amostra.

Influence of door handles design in effort perception: accessibility and usability

The application of ergonomics in product design is essential to its accessibility and usability. The development of manual devices should be based on ergonomic principles. Effort perception analysis is an essential approach to understand the physical and subjective aspects of the interface. The objective of the present study was to analyze the effort perception during a simulated task with different door handles by Portuguese subjects of both genders and different ages. This transversal study agreed with ethical aspects. 180 subjects of both genders pertaining to three age groups have participated. Five door handles with different shapes were evaluated. A subjective numeric rating scale of 5 levels was used to evaluate the effort. For statistical analysis it was applied the Friedman non-parametric test. The results have showed no significant differences of effort perception in door handles "A" and "B"; "A" and "D"; and "D" and "C". Door handle "E" presented the lowest values of all. In general, there's an inverse relationship between the results of biomechanical studies and the effort perception of the same task activity. This shows that door handles design influence directly these two variables and can interfere in the accessibility and usability of these kinds of products.

As geometrias urbana e isoperimétrica: uma alternativa de uso em sala de aula

The main goal of the present study is to propose a methodological approach to the teaching of Geometry and, in particular, to the construction of the concepts of circle (circumference) and ellipse by 7th and 8th grade students. In order to aid the students in the construction of these concepts, we developed a module based on mathematical modeling, and both Urban Geometry (Taxicab Geometry) and Isoperimetric Geometry. Our analysis was based on Jean Piaget's Equilibrium Theory. Emphasizing the use of intuition based on accumulated past experiences, the students were encouraged to come up with a hypothesis, try it out, discuss it with their peers, and derive conclusions. Although the graphs of circles and ellipses assume different shapes in Urban and Isoperimetric Geometry than they do in the standard Euclidian Geometry, their definitions are identical regardless of the metric used. Thus, by comparing the graphs produced in the different metrics, the students were able to consolidate their understanding of these concepts. The intervention took place in a series of small group activities. At the end of the study, the 53 seventh grade and the 55 eighth grade students had a better understanding of the concepts of circle and ellipse

Uma Aplicação de Redes Neurais Auto-Organizaveis à Reconstrução Tridimensional de Superfícies

We propose a multi-resolution approach for surface reconstruction from clouds of unorganized points representing an object surface in 3D space. The proposed method uses a set of mesh operators and simple rules for selective mesh refinement, with a strategy based on Kohonen s self-organizing map. Basically, a self-adaptive scheme is used for iteratively moving vertices of an initial simple mesh in the direction of the set of points, ideally the object boundary. Successive refinement and motion of vertices are applied leading to a more detailed surface, in a multi-resolution, iterative scheme. Reconstruction was experimented with several point sets, induding different shapes and sizes. Results show generated meshes very dose to object final shapes. We include measures of performance and discuss robustness.

Vibrational spectroscopy applied to the study of archeological ceramic artifacts from Guarani culture in Brazil

An archeological artifact can be seen as a chronological element, which helps to determine the age of certain society and to understand the thinking, values and the way of life of this society. Thus, the classification of archeological artifacts is one of the approaches used to study the cultural system of antique societies trying to reconstruct their history. The "Centro de Museologia, Antropologia e Argueologia (CEMAARQ)" of the "Unesp Univ Estadual Paulista" in Presidente Prudente, São Paulo state, Brazil, develops projects within this context (identification and preservation). This is the case of the archeological site named "Lagoa São Paulo-02" discovered in 1993 at the margins of the Parana river in the region of Presidente Epitacio city, São Paulo state, Brazil. This site has ceramic fragments of different shapes and sizes that have a strong influence of traces of the Guarani culture, which is one of the Brazilian native populations. These samples were basically characterized via micro-Raman scattering and Fourier transform infrared absorption (FTIR) spectroscopies. The main objective was to identify the pigments used in the manufacture of the ceramic artifacts and to analyze the composition of the ceramic body to understand how the artifacts were made. Three pigments were found: red, black and white. For the red pigment were identified characteristic bands of hematite, an iron oxide found in the red rocks of the river banks that were eroded by water. The black pigment, probably, is due to the use of vegetal charcoal, which is found in nature as the product of burning organic material such as wood. For the white pigment, the FTIR spectra suggested the use of kaolin, either in the ceramic body or in the proper white pigment, due to the presence of the characteristic bands of the kaolinite. Complementary, the additives applied as anti-plastics were identified as charcoal and quartz, being the latter found in the rocks present in the archeological site. (C) 2010 Elsevier B.V. All rights reserved.

Vortices in a mesoscopic superconducting circular sector

In the present paper we develop an algorithm to solve the time dependent Ginzburg-Landau equations, by using the link variables technique, for circular geometries. In addition, we evaluate the Helmholtz and Gibbs free energy, the magnetization, and the number of vortices. This algorithm is applied to a circular sector. We evaluate the superconduting-normal magnetic field transition, the magnetization, and the superconducting density. Our results point out that, as we reduce the superconducting area, the nucleation field increases. Nevertheless, as the angular width of the circular sector goes to small values the asymptotic behavior is independent of the sample area. We also show that the value of the first nucleation field is approximately the same independently of the form of the circular sector. Furthermore, we study the nucleation of giant and multivortex states for the different shapes of the present geometry.

Influence of microgap location and configuration on the periimplant bone morphology in submerged implants. An experimental study in dogs

Objectives: The vertical location of the implant-abutment connection influences the periimplant bone morphology. It is unknown, however, whether different microgap configurations cause different bone reactions. Therefore, in this study the bone morphologies of two different implant systems were compared.Material and methods: Three months after tooth extraction in eight mongrel dogs, two grit-blasted screw implants with internal Morse taper connection (ANK group) were placed on one side whereas the contralateral side received two oxidized screw implants with external hex (TIU group). One implant on each side was placed level with the bone (equicrestal), the second implant was inserted 1.5mm below bone level (subcrestal). After 3 months the implants were uncovered. Three months after stage two surgery, histometrical evaluations were performed in order to assess the periimplant bone levels (PBL), the first bone-to-implant contact points (BICP), the width (HBD) and the steepness (SLO) of the bone defect.Results: All implants osseointegrated clinically and histologically. Bone overgrowth of the microgap was seen in ANK implants only. No significant differences between ANK and TIU could be detected in neither vertical position for PBL and BICP. However, a tendency in favor of ANK was visible when the implants were placed subcrestally. In the parameters HBD (ANK equicrestal -0.23mm; TIU equicrestal -0.51mm; ANK subcrestal +0.19mm; TIU subcrestal -0.57mm) and SLO (ANK equicrestal 35.36 degrees; TIU equicrestal 63.22 degrees; ANK subcrestal 20.40 degrees; TIU subcrestal 44.43 degrees) more pronounced and significant differences were noted.Conclusions: Within the limits of this study, it is concluded that different microgap designs cause different shapes and sizes of the periimplant ('dish-shaped') bone defect in submerged implants both in equicrestal and subcrestal positions.