Interaction of DNA with anti-cancer drugs: copper-thiosemicarbazide system

The interaction of copper-thiosemicarbazide complexes with DNA was investigated using ultraviolet and infrared spectroscopy. Evidence for the interaction of the complexes with nucleic acid bases and with the phosphate group is presented.

Darwin as a botanist

Charles Darwin on his voyage aboard H. M. S. Beagle contracted a mysterious illness that persisted throughout his life. Despite being ill, he continued his writings. He is remembered as the scientist who putforth the theory that species are changing. A species evolves by the accumulation and preservation of successive slight favourable variations, now known as mutations. In his quest to strengthen his theory on the common origin of all life, and evolution by natural selection, he increasingly turned to plants and carried out experiments at his home-cum-laboratory, focusing on phenomena commonly associated with animals namely, movement. In plant roots, seedlings and climbing plants, he described nyctitropism, geotropism, phototropism and circumnutation. Darwin described the sleep movements in plants in which the petiole hangs down and the leaflets press together in the evening.

Negative experiences and donor return: An examination of the role of asking for something different

BACKGROUND Negative donation experiences, including vasovagal reactions, deter donor retention. However, whether this deterrence effect varies as a function of whole blood (WB) donation history and requests to donate the same or a different product remains unclear. STUDY DESIGN AND METHODS The responses of 894 eligible WB donors who had been approached to convert to plasmapheresis and 954 eligible first-time plasmapheresis donors who had been surveyed on their last donation experience and their intention to donate plasma were considered. This information was matched with individual vasovagal reaction records, deferral category, WB donation history, and subsequent donation behavioral data obtained from the blood collection agency. RESULTS Path analysis indicated that the application of a deferral and an officially recorded vasovagal reaction decreased donors' intentions to continue plasmapheresis donation, but had no effect on WB donors' intentions to convert to plasmapheresis. Consistent with past findings, vasovagal reactions occurred more frequently with female and inexperienced donors. CONCLUSION Experiencing vasovagal reactions and deferrals may not universally deter donors from continuing to donate. Rather, the offer to convert to another form of donation—in this instance, plasmapheresis—after experiencing a negative donation event while donating WB may be sufficient to eliminate the deterrence effect on retention.

Molecular Characterization of Sclerospora graminicola, the Incitant of Pearl Millet Downy Mildew Using ISSR Markers

The DNA polymorphism among 22 isolates of Sclerospora graminicola, the causal agent of downy mildew disease of pearl millet was assessed using 20 inter simple sequence repeats (ISSR) primers. The objective of the study was to examine the effectiveness of using ISSR markers for unravelling the extent and pattern of genetic diversity in 22 S. graminicola isolates collected from different host cultivars in different states of India. The 19 functional ISSR primers generated 410 polymorphic bands and revealed 89% polymorphism and were able to distinguish all the 22 isolates. Polymorphic bands used to construct an unweighted pair group method of averages (UPGMA) dendrogram based on Jaccard's co-efficient of similarity and principal coordinate analysis resulted in the formation of four major clusters of 22 isolates. The standardized Nei genetic distance among the 22 isolates ranged from 0.0050 to 0.0206. The UPGMA clustering using the standardized genetic distance matrix resulted in the identification of four clusters of the 22 isolates with bootstrap values ranging from 15 to 100. The 3D-scale data supported the UPGMA results, which resulted into four clusters amounting to 70% variation among each other. However, comparing the two methods show that sub clustering by dendrogram and multi dimensional scaling plot is slightly different. All the S. graminicola isolates had distinct ISSR genotypes and cluster analysis origin. The results of ISSR fingerprints revealed significant level of genetic diversity among the isolates and that ISSR markers could be a powerful tool for fingerprinting and diversity analysis in fungal pathogens.

Multivalent ligand presentation as a central concept to study intricate carbohydrate-protein interactions

Studying the weak binding affinities between carbohydrates and proteins has been a central theme in sustained efforts to uncover intricate details of this class of biomolecular interaction. The amphiphilic nature of most carbohydrates, the competing nature of the surrounding water molecules to a given protein receptor site and the receptor binding site characteristics led to the realization that carbohydrates are required to exert favorable interactions, primarily through clustering of the ligands. The clustering of sugar ligands has been augmented using many different innovative molecular scaffolds. The synthesis of clustered ligands also facilitates fine-tuning of the spatial and topological proximities between the ligands, so as to allow the identification of optimal molecular features for significant binding affinity enhancements. The kinetic and thermodynamic parameters have been delineated in many instances, thereby allowing an ability to correlate the multivalent presentation and the observed ligand-receptor interaction profiles. This critical review presents various multivalent ligands, synthetic and semisynthetic, and mechanisms by which the weak binding affinities are overcome, and the ligand-receptor complexation leads to significantly enhanced binding affinities (157 references).

On the hardness of shear bands in amorphous alloys

The nanoindentation hardness of individual shear bands in a Zr-based metallic glass was investigated in order to obtain a better understanding of how shear band plasticity is influenced by non-crystalline defects. The results clearly showed that the shear band hardness in both as-cast and structurally relaxed samples is much lower than the respective hardness of undeformed region. Interestingly, inter-band matrix also exhibited lower hardness than undeformed region. The results are discussed in terms of the influence of structural state and the prevailing mechanism of plastic deformation.

BCN:A Graphene Analogue with Remarkable Adsorptive Properties

A new analogue of graphene containing boron, carbon and nitrogen (BCN) has been obtained by the reaction of high-surface-area activated charcoal with a mixture of boric acid and urea at 900 degrees C. X-ray photoelectron spectroscopy and electron energy-loss spectroscopy reveal the composition to be close to BCN. The X-ray diffraction pattern, high-resolution electron microscopy images and Raman spectrum indicate the presence of graphite-type layers with low sheet-to-sheet registry. Atomic force microscopy reveals the sample to consist of two to three layers of BCN, as in a few-layer graphene. BCN exhibits more electrical resistivity than graphene, but weaker magnetic features. BCN exhibits a surface area of 2911 m(2)g(-1), which is the highest value known for a BxCyNz composition. It exhibits high propensity for adsorbing CO2 (approximate to 100 wt %) at 195 K and a hydrogen uptake of 2.6 wt % at 77 K. A first-principles pseudopotential-based DFT study shows the stable structure to consist of BN3 and NB3 motifs. The calculations also suggest the strongest CO2 adsorption to occur with a binding energy of 3.7 kJ mol(-1) compared with 2.0 kJ mol(-1) on graphene.

Simultaneous observation of positive and negative nuclear Overhauser effects in oligopeptides due to segmental motio

Nuclear Overhauser effect (NOE) studies of the symmetrical cystine peptides (Formula: see text) (n = 1-3) in dimethylsulfoxide, have resulted in the simultaneous observation of both positive and negative NOEs. Positive NOEs are observed on the Trp C2H and C4H protons of the indole ring upon irradiation of Trp C alpha H and C beta H2 resonances in the peptides where n = 1 and 2. Negative NOEs are observed between backbone NH and C alpha H protons. The magnitudes of the observed NOEs are sensitive to changes in molecular size and solvent viscosity. The results demonstrate that NOEs may be a useful probe of sidechain segmental motion in oligopeptides.

High-Throughput Flexible Constraint Length Viterbi Decoders on De Bruijn, Shuffle-Exchange and Butterfly Connected Architectures

Flexible constraint length channel decoders are required for software defined radios. This paper presents a novel scalable scheme for realizing flexible constraint length Viterbi decoders on a de Bruijn interconnection network. Architectures for flexible decoders using the flattened butterfly and shuffle-exchange networks are also described. It is shown that these networks provide favourable substrates for realizing flexible convolutional decoders. Synthesis results for the three networks are provided and a comparison is performed. An architecture based on a 2D-mesh, which is a topology having a nominally lesser silicon area requirement, is also considered as a fourth point for comparison. It is found that of all the networks considered, the de Bruijn network offers the best tradeoff in terms of area versus throughput.

Modular design of synthetic protein mimics. Crystal structures, assembly, and hydration of two 15- and 16-residue apolar, leucyl-rich helical peptides

Two IS- and 16-residue peptides containing a-aminoisobutyric acid (Aib) have been synthesized, as part of a strategy to construct stereochemically rigid peptide helices, in a modular approach to design of protein mimics. The peptides Boc-(Val-Ala-Leu-Aib),-OMe ( I ) and Boc-Val-Ala-Leu-Aib-Val-Ala-Leu-(Val-Ala-Leu-Aib()11z)- OhaMvee been crystallized.Both crystals are stable only in the presence of mother liquor or water. The crystal data are as follows. I: C78H140N16019~2H20,P2,, a = 16.391 (3) A, b = 16.860 (3) A, c = 18.428 (3) A, p = 103.02 (I)O, Z = 2, R = 9.6% for 3445 data with lFol >30(F), resolution 0.93 A. 11: C7,Hl,,N,S018.7.5H,0, C2221, a = 18.348 ( 5 ) A, b = 47.382 (1 1) A, c = 24.157 ( 5 ) A, Z =8, R = l0,6%, for 3147 data with lFol > 3a(F), resolution 1.00 A. The 15-residue peptide (11) is entirely a helical, while the 16-residue peptide ( I ) has a short segment of 310 helix at the N terminus. The packing of the helices in the crystals is rather incfficicnt with no particular attractions between Leu-Leu side chains, or any other pair. Both crystals have fairly large voids, which are filled with water molecules in a disordered fashion. Water molecule sites near the polar head-to-tail regions are well detcrmined, those closer to the hydrophobic side chains less so and a number of possible water sites in the remaining "empty" space are not determined. No interdigitation of Leu side chains is observed in the crystal as is hypothesized in the "leucine zipper" class of DNA binding proteins.

A hybrid computer for X-ray crystallography

A hybrid computer for structure factor calculations in X-ray crystallography is described. The computer can calculate three-dimensional structure factors of up to 24 atoms in a single run and can generate the scatter functions of well over 100 atoms using Vand et al., or Forsyth and Wells approximations. The computer is essentially a digital computer with analog function generators, thus combining to advantage the economic data storage of digital systems and simple computing circuitry of analog systems. The digital part serially selects the data, computes and feeds the arguments into specially developed high precision digital-analog function generators, the outputs of which being d.c. voltages, are further processed by analog circuits and finally the sequential adder, which employs a novel digital voltmeter circuit, converts them back into digital form and accumulates them in a dekatron counter which displays the final result. The computer is also capable of carrying out 1-, 2-, or 3-dimensional Fourier summation, although in this case, the lack of sufficient storage space for the large number of coefficients involved, is a serious limitation at present.

Raman spectra of crystalline double sulphates

Raman spectra of single crystals of K2M(SO4)2 · 6 H2O where M=Mg, Zn, Ni or Co have been recorded for the first time using λ 2537 as the exciting radiation. The corresponding five single sulphates have also been studied. Interesting results concerning the substitution of magnesium, zinc, nickel or cobalt in the double sulphate lattice on the sulphate frequencies are observed. The lattice spectra of these double sulphates are analysed group theoretically and discussed in relation to the lattice spectra of the corresponding individual sulphates. Certain new results concerning the Raman spectra of the individual sulphates have also been obtained and in the case of CoSO4 · 7 H2O the spectrum has been recorded for the first time.

Participes présents et gérondifs en traduction finnoise : perte ou changement de valeur ?

Les participes présents apparaissent, entre autres, dans des constructions à prédication seconde détachées : (1) Intervenant hier soir à Ankara, […], Vladimir Poutine s’est risqué à […]. (Le Figaro 7.12.2004 : 4) Même si les gérondifs, formes adverbiales du verbe (« converbes », cf. Haspelmath & König 1995), n’ont pas d’incidence nominale, contrairement aux participes présents, formes adjectivales du verbe, et ne sont donc pas toujours comptés parmi les constructions à prédication seconde (p.ex. Neveu 1998), les deux ont des emplois assez proches : dans des énoncés du type (2a-b), le participe adjoint peut être paraphrasé par un gérondif, même si son statut fonctionnel n’est pas le même (Halmøy, 2003 : 156-157) : (2a) Arrivant à Paris, Emile a proposé à Léa de [...]. (2b) En arrivant à Paris, Emile a proposé à Léa de[...]. (Halmøy, 2003 : 157) Le finnois ne connaît ni ce genre de constructions détachés ni de forme appelée ‘gérondif’, et les deux participes présents finnois (actif et passif) ne correspondent jamais à un participe présent détaché français : en plus de subordonnées, on trouve à leur place le deuxième infinitif, soit à l’inessif, soit à l’instructif, formes nominales qu’on trouve également dans la traduction des gérondifs : (3a) […] ? me demanda-t-elle sèchement en me montrant l’une des lignes incriminées. (Nothomb, p. 62) […] : hän kysyi minulta kuivakkaasti näyttäen erästä Unajin moittimaa riviä. (Suni, p. 4) (3b) L’espace d’un instant, il sourit, croyant que […] je m’étais trompée de commodités. (Nothomb, p. 138-139) Hetken hän hymyili luullen, että minä […] olin erehtynyt mukavuuslaitoksesta. (Suni, p. 94) : Dans cette communication, nous examinerons quatre traductions littéraires en nous demandant dans quels cas et de quelle manière la différence entre le participe et le gérondif a éventuellement été prise en considération.

Pajala–Kolarin ja Soklin kaivoshankkeisiin liittyvien rautatie- ja tieinvestointien ja Kemin satamainvestointien aluetaloudelliset vaikutukset

Lappiin suunnitteilla olevat Pajala–Kolarin rauta- ja Soklin fosforikaivos ovat megaluokan hankkeita. Kaivosten rakentaminen ei voi kuitenkaan toteutua jos niiden tarvitsemia rautatie-, satama- ja tieinvestointeja ei voida toteuttaa. Tutkimuksen tavoitteena oli arvioida näiden väyläinvestointien aluetaloudellisia vaikutuksia. Tutkimus on jatkoa Ruraliassa juuri valmistuneelle yhdeksää Pohjois- ja Itä-Suomen kaivoshanketta koskevalle tutkimukselle, jossa keskitytään itse kaivosinvestointien vaikutuksiin. Tutkimuksen on rahoittanut Liikenne- ja viestintäministeriö yhdessä Työ- ja elinkeinoministeriön kanssa. Työvälineenä oli Ruraliassa kehitetty RegFinDyn-aluemalli. Simuloinnit suoritettiin vuosille 2008–2030 ja raportoitiin Lapin seutukuntien tasolla. Tulosten mukaan kaikki, mutta erityisesti mittavat rautatieinvestoinnit olisivat merkittäviä seutukuntien taloudelliselle kasvulle. Äkäsjoki–Ajos radan rakentaminen auttaisi Tunturi-Lapin, Torniolaakson ja Kemi–Tornion seutukuntia taantuman yli. Taloudellinen kasvu voisi lisääntyä läntisen Lapin seutukunnissa yhteensä 0,6–2,2% vuoteen 2011 ja yhteensä 1,3–4,3% vuoteen 2016 mennessä. Tämä olisi keskimäärin 0,1–0,5% vuodessa. Soklin kaivoksen tapauksessa Kemijärvi–Kelloselkä–Sokli rautatien vaikutukset Itä- ja Pohjois-Lapin seutukuntiin olisivat merkittäviä. Investointien edetessä Itä-Lapin seutukunnan taloudellinen kasvu voisi vahvistua kumulatiivisesti tarkasteltuna 8,3% vuoteen 2013 mennessä. Vuosikeskiarvona tämä olisi 2,8%. Radan vaikutus Pohjois-Lapin taloudelliseen kasvuun olisi pienempi, vuoteen 2014 mennessä yhteensä 3% eli keskimäärin 0,8% vuodessa. Väyläinvestointien työllisyysvaikutukset olisivat myönteisiä. Pajala–Kolarin kaivoksen rautatieinvestoinnit toisivat läntiseen Lappiin uusia työpaikkoja vuoteen 2015 mennessä yhteensä 418. Tästä Tunturi-Lapin osuus olisi 147, Torniolaakson 114 ja Kemi–Tornion seutukunnan 157. Vastaavat vuosikeskiarvot olisivat 52, 18, 14 ja 20. Soklin kaivoksen rautatieinvestoinnit toisivat jonkun verran enemmän uusia työpaikkoja Pajala–Kolariin verrattuna koska investoinnit olisivat suuremmat. Radan rakentaminen voisi tuoda Itä-Lappiin yhteensä 506 uutta työpaikkaa vuoden 2013 loppuun mennessä. Pohjois-Lapin työllisyys voisi lisääntyä 153 uudella työpaikalla. Yhteensä voisi siten syntyä 660 uutta työpaikkaa. Vastaavat vuosikeskiarvot olisivat 169, 51, 220 uutta työpaikkaa. Kun kaivoksia tarkastellaan yhdessä, työllisyysvaikutukset olisivat suurimmat vuonna 2015, jonka loppuun mennessä väyläinvestoinnit voisivat luoda yhteensä 1288 uutta työpaikkaa. Vastaava vuosikeskiarvo olisi 161. Taloudellisen kasvun ohella työllisyystulokset korostavat analysoitujen väyläinvestointien myönteistä aluetaloudellista merkitystä. Ruralia-instituutin arvioinnin perusteella molempien kaivosten rautatie-, satama- ja tieinvestoinnit olisivat toteuttamiskelpoisia aluetaloudellisin perustein. Ne lisäisivät tuotantoa, työllisyyttä, tuloja, kulutusta ja verotuloja useissa Lapin seutukunnissa.