Principal subspaces for the affine Lie algebras in types DD, EE and FF

We consider the principal subspaces of certain level $k\geqslant 1$ integrable highest weight modules and generalized Verma modules for the untwisted affine Lie algebras in types $D$, $E$ and $F$. Generalizing the approach of G. Georgiev we construct their quasi-particle bases. We use the bases to derive presentations of the principal subspaces, calculate their character formulae and find some new combinatorial identities.Comment: 24 pages, 1 figure, comments are welcom

Systems of conservation tillage in Europe

Neke znanstvene spoznaje, ali još više praktične opservacije i empirija stvorile su podlogu da se već krajem 19., a osobito u prvim desetljećima 20. stoljeća počne na nov način razmišljati o obradi tla kao tradicionalnom mehaničkom zahvatu u fizikalni kompleks neposredno, te kemijski i biološki posredno. Međutim, tek razvojem nekih prirodnih znanosti nakon drugog svjetskog rata, a osobito u posljednja dva desetljeća ispunile su se i praktične pretpostavke za realizaciju nekih, ranije nezamislivih koncepcija u uzgoju poljoprivrednih kultura. Time je ujedno stvorena osnova za diferencirani pristup u obradi tla. Kao logična posljedica toga javile su se i nove metode obrade tla unutar kojih konzervacijska odnosno reducirana obrada tla zauzima središnje mjesto. Nakon određenog provjeravanja putem egzaktnih znanstvenih istraživanja, ali i posvemašne empirije, nove metode obrade već su duboko zaživjele u praksi mnogih europskih zemalja, no s različitim uspjehom u različitim, često potpuno divergentnim ekološkim uvjetima. Ipak, mora se reći da su se one već duboko usadile i u psihu onih uzgajatelja bilja koji u novim trendovima obrade sagledavaju ne samo njene praktične aspekte, već i one znatno sofisticiranije koje u prvi plan stavljaju brigu za očuvanje ravnoteže stanišnih faktora unutar određenog agroekosustava. Ovaj rad i drugih pet radova koji se iznose bave se problemima konzervacijske obrade tla u najširem smislu riječi na području cijele Europe. U njemu se na osnovi brojnih znanstvenih publikacija prikupljenih od najpozva-nijih znanstvenika u ovom području u Europi daje osvrt na pravac, opseg i rezultate provedenih istraživanja. Uz razmatranje nekih općih pitanja obrade tla, posebno se pojmovno razmatra konzervacijska obrada tla, procjena pogodnosti tla za njezinu primjenu, stanje konzervacijske obrade tla u Europi i razvojne tendencije u minimalnoj obradi tla, uključujući obradu tla čizelom i "paraplugom". Konzervacijska obrada tla razmatra se i s nekih drugih aspekata – s aspekta utroška energije, primjene specijalnih sijačica u ovom sustavu obrade, sa stajališta suzbijanja korova, borbe protiv erozije, te promjena u fizikalnom, kemijskom i biološkom kompleksu tla s posebnim naglaskom na odnos konzervacijske obrade tla prema primjeni dušika i djelomično biljnim bolestima. Na kraju se daje osvrt na reaktivnost nekih važnijih oraničnih kultura na različite oblike konzervacijske obrade tla. Ovaj sustav obrade tla, pod pretpostavkom da se još istraže objektivno i s potrebnom pozornošću neke njegove specifične osobitosti u našim ekološkim uvjetima, trebao bi se sasvim udomaćiti u našoj proizvodnoj praksi ne samo kao zamjena vladajućim sustavima u ekvivalentnim odnosima, već dijelom i kao njihova nadopuna.At the end of the 19th century, but specially in the first decades of the 20th century, some scientific findings and, particularly, practical observation and experience, induced new ways of thinking about soil tillage, the traditional intervention directly into the physical and indirectly into the chemical and biological soil complex. However, it was only after the Second World War, notably in the last two decades, that advances in some natural sciences made it possible to implement some, earlier unconceivable, ideas on growing field crops. This constituted the basis for a different approach to soil tillage. As a consequence, new methods of soil tillage have been, among which conservation, that is reduced tillage is most important. After being tested by exact scientific investigations, as well as by practical experience, new methods have already become common practice in a number of European countries, where they are applied with different success in sometimes quite divergent ecological conditions. Nevertheless, it should be noted that they have became deeply rooted in the minds of those plant growers who do not regard new trends in soil tillage only from their practical aspects, but also from the more sophisticated aspect of preserving the balance of habitat factors within a particular ecosystem. This paper and the other five papers which are presented in this journal deal with the problems of conservation tillage, in the broadest sense of the word, all over Europe. Based on numerous scientific publications, obtained from the most eminent scientists in the field in Europe, a survey is given of the trends, scope and investigation results. In addition to some general considerations relating to soil tillage, conceptual interpretation is made of conservation soil tillage, estimation of soil suitability for its application, standing of conservation tillage in Europe and the development trends of minimum tillage, including treatments with chisel- and para-plough. Furthermore, conservation tillage is also treated from some other aspects, such as energy consumption, application of special seeding machines for the tillage system, weed control, erosion control, as well as changes of the physical, chemical and biological soil properties, with special emphasis on the relation between conservation tillage and nitrogen application, and partly plant diseases. At the end, a survey is given of the responses of some major field crops to different kinds of conservation tillage. On the assumption that this tillage system is further investigated, objectively and thoroughly, in terms of some of its specific characteristics in the ecological conditions of this country, it could find its permanent place in our agricultural production, not only as a substitute for the prevailing systems, in equivalent proportion, but also as a supplement to them

Conservation tillage in the European countries

Iz prikazanog rada vidljivo je da konzervacijska odnosno reducirana obrada tla u različitim europskim zemljama ima svoje specifičnosti. One ponajčešće proizlaze iz različitih ekoloških uvjeta, ali i objektivnih mogućnosti za prihvaćanje novih znanstvenih spoznaja i tehnoloških inovacija, a dijelom i različitih koncepcija u području obrade tla. Ipak, u većini zemalja konzervacijska obrada tla nije poprimila one razmjere koji bi se prema prirodnim uvjetima mogli očekivati. Ne treba smetnuti s uma i subjektivne poteškoće koje traže viši stupanj obrazovanja i veći smisao za znanstveni pristup konzervacijskoj obradi tla. Što se tiče naše zemlje, istraživanja s konzervacijskom obradom tla trebalo bi proširiti na sve tipove tala i one, prvenstveno ratarske kulture u kojih se očekuje pozitivna reakcija na konzervacijsku obradu tla.The presented paper points to the specific features of conservation, or reduced, tillage in different European countries. The specificities are mainly due to different ecological conditions, but also to objective potentials of adopting new scientific findings and technological innovations, and partly also different concepts in the sphere of soil tillage. Still, in most countries conservation tillage has not extended to such an extent as could be expected according to their natural conditions. Subjective difficulties demanding a higher educational level and orientation to the scientific approach to conservation tillage should not be disregarded either. As regards this country, investigations of conservation tillage should be extended to all soil types and to those, primarily field crops which are expected to respond favourably to conservation tillage

The influence of residual fertilizing by phosphorus and potassium upon sugar beat root yield and some soil chemical properties in crop rotation maize-soybean-winter wheat-sugar beat

Na lesiviranom tlu na pretaloženom lesu na lokalitetu Lukač (Virovitica) provedena su višegodišnja istraživanja gnojidbe na zalihu fosforom i kalijem za šećernu repu u sklopu četverogodišnjeg mjembenog plodoreda u dvije rotacije. Uz negnojenu varijantu i standardnu mineralnu gnojidbu, istraživanja su obuhvatila gnojidbu na zalihu u dvije varijante za četverogodišnje razdoblje i jednu varijantu za dvogodišnje razdoblje, dakako s različitim izvorima fosfora, pa donekle i kalija. Što se tiče prinosa korijena, šećerna je repa vrlo povoljno reagirala na gnojidbu na zalihu fosforom i kalijem, pri čemu ne bi trebalo biti dvojbe da je u tome kalij odigrao ključnu ulogu. Izvjesna, ali ipak samo relativna prednost na strani je tripleksa i kalijeve soli pred kompleksnim gnojivom. Povećanje sadržaja biljci pristupačnog fosfora i kalija u tlu prema višegodišnjim prosječnim vrijednostima nije sukladno primijenjenim količinama, iako je značajnije u kalija. Ipak, u pojedinim godinama to je povećanje signifikantno pod utjecajem fosforno-kalijeve gnojidbe. U relativnom se smislu smanjuje uglavnom zasićenost adsorpcijskog kompleksa bazama u odnosu na kontrolu. Vrijednosti u pojedinim godinama vrlo su heterogene pod utjecajem fosforno-kalijeve gnojidbe.Residual fertilization with phosphorus and potassium was investigated on sugar beet grown in two rotations within the four-year field crop rotation. The several years long trial was set up on luvic soil on redeposited loess at the locality Lukač (Virovitica). Besides the unfertilized variant and standard mineral fertilization, the trial also included two variants of residual fertilization for a four-year period and one variant for a two-year period, naturally with different sources of phosphorus, and partly also potassium. As regards its root yields, sugar beet responded favourably to residual fertilization with phosphorus and potassium, in which potassium indisputably played the key role. It was found that triplex and potassium salt had an advantage, though only relative, over complex fertilizer. According to average several-years values, increase of plant available phosphorus and potassium content in the soil was not proportional to their quantities applied, though it was more significant for potassium. Nonetheless, this increase was significant in some years due to phosphorus-potassium fertilization. In a relative sense, mainly the base saturation of the cation exchange capacity was reduced compared to the control. Under the influence of phosphorus-potassium fertilization, very heterogeneous values were recorded in particular trial years

Variation in the Biomolecular Interactions of Nickel(Ii) Hydrazone Complexes Upon Tuning the Hydrazide Fragment

Three new bivalent nickel hydrazone complexes have been synthesised from the reactions of [NiCl2(PPh3)(2)] with H2L {L = dianion of the hydrazones derived from the condensation of o-hydroxynaphthaldehyde with furoic acid hydrazide (H2L1) (1)/thiophene-2-acid hydrazide (H2L2) (2)/isonicotinic acid hydrazide (H2L3) (3)} and formulated as [Ni(L-1)(PPh3)] (4), [Ni(L-2)(PPh3)] (5) and [Ni(L-3)(PPh3)] (6). Structural characterization of these compounds 4-6 were accomplished by using various physico-chemical techniques. Single crystal X-ray diffraction data of complexes 4 and 5 proved their distorted square planar geometry. In order to ascertain the potential of the above synthesised compounds towards biomolecular interactions, additional experiments involving interaction with calf thymus DNA (CT DNA) and bovine serum albumin (BSA) were carried out. All the ligands and corresponding nickel(II) chelates have been screened for their scavenging effect towards O-2(-), OH and NO radicals. The efficiency of complexes 4-6 to arrest the growth of HeLa, HepG-2 and A431 tumour cell lines has been studied along with the cell viability test against the non-cancerous NIH 3T3 cells under in vitro conditions.University Grants Commission, New Delhi under the UGC-SAP-DRSRobert A. Welch Foundation F-0003Chemistr

Synthesis and Coordination Compounds of A Bis(Imino)Acenaphthene (Bian)-Supported N-Heterocyclic Carbene

The bis(imino)acenaphthene-supported N-heterocyclic carbene IPr(BIAN) has been prepared by deprotonation of the precursor imidazolium chloride. Treatment of IPr(BIAN) imidazolium chloride with Ag(2)O afforded the silver complex [IPr(BIAN)]AgCl which can be converted into the corresponding gold complex [IPr(BIAN)]AuCl by reaction with (tht)AuCl (tht = tetrahydrothiophene). The iridium complex [IPr(BIAN)]Ir(COD)Cl was prepared by reaction of the imidazolium chloride with KO(t)Bu and [Ir(COD)Cl](2) and subsequently converted to the carbonyl complex [IPr(BIAN)]Ir(CO)(2)Cl by exposure to an atmosphere of CO. All new compounds were characterized by single-crystal X-ray diffraction, multinuclear NMR, MS and HRMS data.Robert A. Welch Foundation F-0003National Science Foundation 0741973Chemistr