The influence of impurities on calcium phosphate floc structure and size in sugar solutions

Settling, dewatering and filtration of flocs are important steps in industry to remove solids and improve subsequent processing. The influence of non-sucrose impurities (Ca2+, Mg2+, phosphate and aconitic acid) on calcium phosphate floc structure (scattering exponent, Sf), size and shape were examined in synthetic and authentic sugar juices using X-ray diffraction techniques. In synthetic juices, Sf decreases with increasing phosphate concentration to values where loosely bound and branched flocs are formed for effective trapping and removal of impurities. Although, Sf did not change with increasing aconitic acid concentration, the floc size significantly decreased reducing the ability of the flocs to remove impurities. In authentic juices, the flocs structures were marginally affected by increasing proportions of non-sucrose impurities. However, optical microscopy indicated the formation of well-formed macro-floc network structures in sugar cane juices containing lower proportions of non-sucrose impurities. These structures are better placed to remove suspended colloidal solids.

Fluorescence polarization as a tool to study lectin-sugar interaction. An investigation of the binding of 4-methylumbelliferyl beta-D-galactopyranoside to Abrus precatorious agglutinin

Polarization of ligand fluorescence was used to study the binding of 4-methylumbelliferyl beta-D-galactopyranoside (MeUmb-Galp) to Abrus precatorious agglutinin. The binding of the fluorescent sugar to the lectin led to considerable polarization of the MeUmb-Galp fluorescence, which was also quenched by about 30% on binding to the lectin. The binding of the fluorescent sugar was carbohydrate-specific, as evidenced by inhibition of both fluorescence polarization and quenching when lectin was preincubated with lactose. The association constant as determined by fluorescence polarization is 1.42 x 10(4) M-1 at 25 degrees C and is in excellent agreement with those determined by fluorescence quenching (Ka = 1.51 x 10(4) M-1) and equilibrium dialysis (Ka = 1.62 x 10(4) M-1) at 25 degrees C. The numbers of binding sites as determined by fluorescence polarization, quenching and equilibrium dialysis agree very well with one another, n being equal to 2.0 +/- 0.05. The consistency between the association constant value determined by fluorescence polarization, quenching and equilibrium dialysis shows the validity of this approach to study lectin-sugar interaction.

Sugarcane-Based Biofuels and Bioproducts

Sugarcane has garnered much interest for its potential as a viable renewable energy crop. While the use of sugar juice for ethanol production has been in practice for years, a new focus on using the fibrous co-product known as bagasse for producing renewable fuels and bio-based chemicals is growing in interest. The success of these efforts, and the development of new varieties of energy canes, could greatly increase the use of sugarcane and sugarcane biomass for fuels while enhancing industry sustainability and competitiveness. Sugarcane-Based Biofuels and Bioproducts examines the development of a suite of established and developing biofuels and other renewable products derived from sugarcane and sugarcane-based co-products, such as bagasse. Chapters provide broad-ranging coverage of sugarcane biology, biotechnological advances, and breakthroughs in production and processing techniques. This text brings together essential information regarding the development and utilization of new fuels and bioproducts derived from sugarcane. Authored by experts in the field, Sugarcane-Based Biofuels and Bioproducts is an invaluable resource for researchers studying biofuels, sugarcane, and plant biotechnology as well as sugar and biofuels industry personnel.

Growing Up Vietnamese in Finland - Looking Back 12 Years Later : The Well-Being and Sociocultural Adaptation of Vietnamese as Children or Adolescents and as Young Adults

Varttuminen vietnamilaisena Suomessa: 12 vuoden seurantajakso – Vietnamilaisten hyvinvointi ja sosiokulttuurinen sopeutuminen lapsena/nuorena sekä nuorena aikuisena Tämä tutkimus oli määrällinen pitkittäistutkimus lapsena tai nuorena vuosina 1979-1991 Suomeen saapuneiden vietnamilaisten akkulturaatiosta (kulttuurin muutoksista), psyykkisestä hyvinvoinnista ja sosiokulttuurisesta sopeutumisesta. Tutkimukseen osallistui ensimmäisessä vaiheessa (vuonna 1992) 97 satunnaisesti valittua vietnamilaista peruskoululaista ympäri maata, joita verrattin suomalaisiin luokkatovereihin. Seurantavaiheeseen (vuonna 2004) osallistui 59 ensimmäisessä vaiheessa mukana ollutta vietnamilaista, nyt iältään 20 – 31 -vuotiaita. Tutkimuksen tavoitteena oli selvittää mitkä tekijät ennustivat akkulturaation lopputuloksia, samalla huomioiden iän ja ympäristön (kontekstin) vaikutukset psyykkiseen hyvinvointiin ja sosiokulttuuriseen sopeutumiseen. Yksittäiset akkulturaatiodimensiot (kieli, arvot ja identiteetti) osoittautuivat tärkeämmiksi psyykkiselle hyvinvoinnille ja sosiokulttuuriselle sopeutumiselle kuin etniset, kansalliset tai kaksikulttuuriset profiilit, joissa yhdistyivät ao. kieli, arvot ja identiteetti. Identiteettimuutosta tapahtui (etniseen) vietnamilaiseen suuntaan ajan kuluessa, kun taas arvomuutosta tapahtui (kansalliseen) suomalaiseen suuntaan. Sekä suomen että vietnamin kielen taito lisääntyivät ajan myötä, millä oli myönteisiä vaikutuksia sekä psyykkiseen hyvinvointiin että sosiokulttuuriseen sopeutumiseen. Lähtötilanteen psyykkinen hyvinvointi ennusti hyvinvointia (masennuksen puutetta ja itsetuntoa) aikuisena, mutta sosiokulttuurinen sopeutuminen (koulumenestys) lapsena tai nuorena ei ennustanut kouluttautumista aikuisena. Parempi suomen kielen taito ja vähemmän identifioitumista suomalaiseksi aikuisena sekä masentuneisuuden puute ja vähemmän koettua syrjintää lapsena tai nuorena erottelivat psyykkisesti paremmin voivat aikuiset (ei-masentuneet) heistä, jotka olivat masentuneita. Parempaa kouluttautumista aikuisena ennustivat toisaalta vähemmän koettua syrjintää lapsena tai nuorena ja toisaalta aikuisena parempi suomen kielen taito, suurempi kansallisten (suomalaisten) itsenäisyysarvojen kannattaminen, mutta kuitenkin vähemmän identifioitumista suomalaisiin. Koetun syrjinnän merkitys psyykkiselle hyvinvoinnille, erityisesti lapsena tai nuorena, sekä sen pitkäaikaisvaikutukset psyykkiselle hyvinvoinnille ja sosiokulttuuriselle sopeutumiselle aikuisena osoittavat tarpeen puuttua varhain psyykkisiin ongelmiin sekä parantaa etnisten ryhmien välisiä suhteita. Avainsanat: akkulturaatio, psyykkinen hyvinvointi, sosiokultuurinen sopeutuminen, kieli, arvot, identiteetti, vietnamilainen, Suomi, lapset, nuoret, nuoret aikuiset

Growing Flowers in the Frost: Civic Activity, Citizenship and Gender in Russia

This study analyzes civic activity, citizenship and their gendered manifestations in contemporary Russia. It is based on a case study conducted in the city of Tver , located in the vicinity of Moscow, during 2001-2005. The data consists of interviews with civic activists and municipal and regional authorities; observations of civic organizations; and a quantitative survey conducted among local civic groups. The theoretical and methodological framework of the study draws upon a micro perspective on organization, discourse analysis, gender and citizenship theories and Pierre Bourdieu s theory of fields and capital. This study develops theoretical understanding of the characteristics and logic of civic organization in Russia. It shows that social class centrally structures the field of civic activity. Organizations can be seen as a vehicle of the educated class to advocate their interests, help themselves and seek both social and individual-level change. The study also argues that civic organizations founded during the post-Soviet era are often an institutionalized form of informal social networks. Networks, which were a central element of everyday interaction in Soviet society, are a resource and often the only resource available that can be made use of in contemporary organizational activities. The study argues that gender operates as a key structuring principle in the Russian socio-political community. Civic activity is often discursively associated with femininity and institutional politics with masculinity. Women tend to participate more than men in civic organizations, while men dominate the formal political domain. The study shows that civic organizations are important loci of communality. This communality, however, differs from the communality envisioned in the communitarian and social capital debates in the West. It is selective communality , as it is restricted to the members of the organizations and does not create generalized reciprocity and trust. Civic organizations tend to build upon and reproduce the traditional Russian organizational form of circles , kruzhki. Along with the analysis of civic activities, the study also examines the redefinition of the role and functions of the state. The authorities interviewed in this study understand civic organizations as serving those goals and interests determined by the authorities, instead of viewing them as sites of citizens self-organization around interests and problems citizens themselves deem important, or as a counterforce to the state. By contrast, civic activists understand the core of organizational activity to be advocacy of their interests and rights, tackling social problems, the pursuit of wider social change and self-help. Co-operation between authorities and organizations tends to be personified and based upon unequal, hierarchical patron-client arrangements, which inhibits the development of democratic governance. The study will be published in Routledge Contemporary Russia and Eastern Europe Series later this year.

Photoswitchable multivalent sugar ligands: Synthesis, isomerization, and lectin binding studies of azobenzene-glycopyranoside derivatives

Coating of azobenzene chromophore with multivalent sugar ligands has been accomplished. Such sugar coating allows the study of the isomerization properties of this chromophore in aqueous solutions. The predominantly cis-isomer-containing photostationary state (PS) mixture of these azobenzene derivatives is found to be stable for hours. The rate constants for their isomerization, as well as the Arrhenius activation energies, are determined experimentally. An assessment of the lectin binding properties of the lactoside bearing isomeric azobenzene derivatives, by isothermal calorimetric methods, reveals the existence of an unusual cooperativity in their binding to lectin peanut agglutinin. Thermodynamic parameters evaluated for the trans and the PS mixture are discussed, in detail, for the lactoside bearing bivalent azobenzene derivative.

Growing up in Affiliation with a Religious Community : A Case Study of Seventh-day Adventist Youth in Finland

This study investigates how the religious community as a socialization context affects the development of young people's religious identity and values, using Finnish Seventh-day Adventism as a context for the case study. The research problem is investigated through the following questions: (1) What aspects support the intergenerational transmission of values and tradition in religious home education? (2) What is the role of social capital and the social networks of the religious community in the religious socialization process? (3) How does the religious composition of the peer group at school (e.g., a denominational school in comparison to a mainstream school) affect these young people s social relations and choices and their religious identity (as challenged versus as reinforced by values at school)? And (4) How do the young people studied negotiate their religious values and religious membership in the diverse social contexts of the society at large? The mixed method study includes both quantitative and qualitative data sets (3 surveys: n=106 young adults, n=100 teenagers, n=55 parents; 2 sets of interviews: n=10 young adults and n=10 teenagers; and fieldwork data from youth summer camps). The results indicate that, in religious home education, the relationship between parents and children, the parental example of a personally meaningful way of life, and encouraging critical thinking in order for young people to make personalized value choices were important factors in socialization. Overall, positive experiences of the religion and the religious community were crucial in providing direction for later choices of values and affiliations. Education that was experienced as either too severe or too permissive was not regarded as a positive influence for accepting similar values and lifestyle choices to those of the parents. Furthermore, the religious community had an important influence on these young people s religious socialization in terms of the commitment to denominational values and lifestyle and in providing them with religious identity and rooting them in the social network of the denomination. The network of the religious community generated important social resources, or social capital, for both the youth and their families, involving both tangible and intangible benefits, and bridging and bonding effects. However, the study also illustrates the sometimes difficult negotiations the youth face in navigating between differentiation and belonging when there is a tension between the values of a minority group and the larger society, and one wants to and does belong to both. It also demonstrates the variety within both the majority and the minority communities in society, as well as the many different ways one can find a personally meaningful way of being an Adventist. In the light of the previous literature about socialization-in-context in an increasingly pluralistic society, the findings were examined at four levels: individual, family, community and societal. These were seen as both a nested structure and as constructing a funnel in which each broader level directs the influences that reach the narrower ones. The societal setting directs the position and operation of religious communities, families and individuals, and the influences that reach the developing children and young people are in many ways directed by societal, communal and family characteristics. These levels are by nature constantly changing, as well as being constructed of different parts, like the pieces of a jigsaw puzzle, each of which alters in significance: for some negotiations on values and memberships the parental influence may be greater, whereas for others the peer group influences are. Although agency does remain somewhat connected to others, the growing youth are gradually able to take more responsibility for their own choices and their agency plays a crucial role in the process of choosing values and group memberships. Keywords: youth, community, Adventism, socialization, values, identity negotiations

Determination of distances of sugar protons from Mn2+ in concanavalin A

1H NMR spin-lattice relaxation time (T1) measurements have been carried out with various sugars, viz. methyl alpha-D-glucopyranoside (alpha-MeGluP), methyl beta-D-lucopyranoside (beta-MeGluP), methyl alpha--annopyranoside (alpha-MeManP), maltose (4-O-alpha-D-glucopyranosyl--glucose), nigerose (3-O-alpha-D-glucopyranosyl-D-glucose), p-nitrophenyl alpha-maltoside (PNP-alpha-maltoside) and p-nitrophenyl beta-maltoside (PNP-beta-maltoside) to determine the distances of sugar protons from Mn2+ in concanavalin A (Con A). With a rotational correlation time of 1.58 x 10(-10) s determined, distances were calculated using Solomon-Bloembergen equation. The data obtained indicated differences in disposition of different groups in the binding site of Con A. An average value of about 10 A was obtained for the distances of sugar protons from Mn2+ in Con A. In the case of mono and disaccharides, the non-reducing end sugar unit was found to be closer to Mn2+ than the reducing end one.

Mechanism of interaction of the antileukemic drug cytosine arabinoside with aromatic peptides : role of sugar conformation and peptide backbone

Interaction of the antileukemic drugs, cytosine-arabinoside (Ara-C) and adenosine-arabinoside (Ara-A) and a structural analogue, cytidine, with aromatic dipeptides has been studied by fluorescence and NMR spectroscopy. Ara-C and cytidine bind tryptophanyl and histidyl dipeptides but not tyrosyl dipeptides, while Ara-A does not bind to any of them. Both studies indicate association involving stacking of aromatic moieties. NMR spectra also indicate a protonation of the histidine moiety by Ara-C. In case of cytidine, the chemical shifts observed on binding to His-Phe imply that the backbone protons of the dipeptide participate in the binding. The conformation of the sugar and the base seem to play a very important role in the binding phenomenon as three similar molecules, Ara-C, Ara-A and cytidine bind in totally different ways.

Evaluation of the profitability of fast-growing tropical trees.

The profitability of fast-growing trees was investigated in the northeastern and eastern provinces of Thailand. The financial, economic, and tentative environmental-economic profitability was determined separately for three fast-growing plantation tree species and for three categories of plantation managers: the private industry, the state (the Royal Forest Department) and the farmers. Fast-growing tree crops were also compared with teak (Tectona grandis), a traditional medium or long rotation species, and Para rubber (Hevea brasiliensis) which presently is the most common cultivated tree in Thailand. The optimal rotation for Eucalyptus camaldulensis pulpwood production was eight years. This was the most profitable species in pulpwood production. In sawlog production Acacia mangium and Melia azedarach showed a better financial profitability. Para rubber was more profitable and teak less profitable than the three fast-growing species. The economic profitability was higher than the financial one, and the tentative environmental-economic profitability was slightly higher than the economic profitability. The profitability of tree growing is sensitive to plantation yields and labour cost changes and especially to wood prices. Management options which aim at pulpwood production are more sensitive to input or output changes than those options which include sawlog production. There is an urgent need to improve the growth and yield data and to study the environmental impacts of tree plantations for all species and plantation types.

Structure of the putative mutarotase YeaD from Salmonella typhimurium in two different forms: in vivo binding of a sugar phosphate

Salmonella typhimurium YeaD (stYeaD), annotated as a putative aldose 1-epimerase, has a very low sequence identity to other well characterized mutarotases. Sequence analysis suggested that the catalytic residues and a few of the substrate-binding residues of galactose mutarotases (GalMs) are conserved in stYeaD. Determination of the crystal structure of stYeaD in an orthorhombic form at 1.9 angstrom resolution and in a monoclinic form at 2.5 angstrom resolution revealed this protein to adopt the beta-sandwich fold similar to GalMs. Structural comparison of stYeaD with GalMs has permitted the identification of residues involved in catalysis and substrate binding. In spite of the similar fold and conservation of catalytic residues, minor but significant differences were observed in the substrate- binding pocket. These analyses pointed out the possible role of Arg74 and Arg99, found only in YeaD-like proteins, in ligand anchoring and suggested that the specificity of stYeaD may be distinct from those of GalMs

Conformational Polymorphism in G-tetraplex Structures: Strand Reversal by Base Flipover or Sugar Flipover

Guanine rich sequences adopt a variety of four stranded structures, which differ in strand orientation and conformation about the glycosidic bond even though they are all stabilised by Hoogsteen hydrogen bonded guanine tetrads. Detailed model building and molecular mechanics calculations have been carried out to investigate various possible conformations of guanines along a strand and different possible orientations of guanine strands in a G-tetraplex structure. It is found that for an oligo G stretch per se, a parallel four stranded structure with all guanines in anti conformation is favoured over other possible tetraplex structures. Hence an alternating syn-anti arrangement of guanines along a strand is likely to occur only in folded back tetraplex structures with antiparallel G strands. Our study provides a theoretical rationale for the observed alternation of glycosidic conformation and the inverted stacking arrangement arising from base flipover, in antiparallel G-tetraplex structures and also highlights the various structural features arising due to different types of strand orientations. The molecular mechanics calculations help in elucidating the various interactions which stabilize different G-tetraplex structures and indicate that screening of phosphate charge by counterions could have a dramatic effect on groove width in these four stranded structures.

Conformational polymorphism in G-tetraplex structures: strand reversal by base flipover or sugar flipover

Guanlne rich sequences adopt a variety of four stranded structures, which differ in strand orientation and conformation about the glycosldic bond even though they are all stabilised by Hoogsteen hydrogen bonded guanlne tetrads. Detailed model building and molecular mechanics calculations have been carried out to investigate various possible conformations of guanlnes along a strand and different possible orientations of guanlne strands In a G-tetraplex structure. It is found that for an ollgo G stretch per se, a parallel four stranded structure with all guanines In anti conformation is favoured over other possible tetraplex structures. Hence an alternating syn-anti arrangement of guanlnes along a strand is likely to occur only in folded back tetraplex structures with antiparallel G strands. Our study provides a theoretical rationale for the observed alternation of glycosldic conformation and the inverted stacking arrangement arising from base filpover, In antlparallel G-tetraplex structures and also highlights the various structural features arising due to different types of strand orientations. The molecular mechanics calculations help in elucidating the various interactions which stabilize different G-tetraplex structures and indicate that screening of phosphate charge by counterions could have a dramatic effect on groove width in these four stranded structures.