bluuebunny/crossref_metadata_2025 huggingface dataset:
The Metallic Zintl Phase Ba3Si4 – Synthesis, Crystal Structure, Chemical Bonding, and Physical Properties
Authors: Aydemir Umut , Ormeci Alim , Borrmann Horst , Böhme Bodo , Zürcher Fabio , Uslu Burcu , Goebel Thorsten , Schnelle Walter , Simon Paul , Carrillo‐Cabrera Wilder , Haarmann Frank , Baitinger Michael , Nesper Reinhard , von Schnering Hans Georg , Grin Yuri
Published: July 2008

The Zintl phase Ba3Si4 has been synthesized from the elements at 1273 K as a single phase. No homogeneity range has been found. The compound decomposes peritectically at 1307(5) K to BaSi2 and melt. The butterfly‐shaped Si46− Zintl anion in the crystal structure of Ba3Si4 (Pearson symbol tP28, space group P42/mnm, a = 8.5233(3) Å, c = 11.8322(6) Å) shows only slightly different Si‐Si bond lengths of d(Si–Si) = 2.4183(6) Å (1×) and 2.4254(3) Å (4×). The compound is diamagnetic with χ ≈ −50 × 10−6 cm3 mol−1. DC resistivity measurements show a high electrical resistivity (ρ(300 K) ≈ 1.2 × 10−3 Ω m) with positive temperature gradient dρ/dT. The temperature dependence of the isotropic signal shift and the spin‐lattice relaxation times in 29Si NMR spectroscopy confirms the metallic behavior. The experimental results are in accordance with the calculated electronic band structure, which indicates a metal with a low density of states at the Fermi level. The electron localization function (ELF) is used for analysis of chemical bonding. The reaction of solid Ba3Si4 with gaseous HCl leads to the oxidation of the Si46− Zintl anion and yields nanoporous silicon.
RbSb2 – Eine mit KSb2 verwandte Zintl‐Phase
Authors: Petri Denis , Röhr Caroline
Published: July 2008

RbSb2 – A Zintl Phase related to KSb2

The electron‐precise Zintl compound RbSb2, which was known to melt incongruently at 418 °C, has been prepared in pure phase from elemental rubidium and antimony in sealed tantalum crucibles. In accordance with the ribbon‐shaped antimonide anions, the compound crystallizes with extremely thin intergrown, mechanically and chemically very sensitive needles of dark‐metallic lustre. The crystal structure could be determined and refined using single crystal x‐ray data (monoclinic, space group C2/m, a = 1403(2), b = 414.0(4), c = 855.7(14) pm, β = 104.45(12)°, Z = 4, R1 = 0.0901) despite the poor quality of the crystals. It shows fused six‐membered rings of two‐ and three‐bonded Sb atoms forming ribbons running along the monoclinic b axis, which can be interpreted as sections of the elemental structure of antimony (dSb‐Sb = 281.9(5) and 286.0(9) pm respectively). The structure of RbSb2 is thus closely related to that of KSb2, which exhibits identical antimony anions. Compared to the potassium compound, the $^{1}_{\infty}\rm [Sb_{2}]^{-}$ ribbons are reoriented against each so that the coordination number of the A counter ions is increased from 6 + 2 (for A = K) to 8 + 2 (for A = Rb). The results of a FP‐LAPW band structure calculation of RbSb2 are used to explain the chemical bonding in this classical Zintl phase with a calculated indirect band gap of 0.38 eV.
Effect of Heavy‐Atom (Br) at the Phenyl Rings of Schiff‐Base Ligands on the NIR Luminescence of their Bimetallic Zn‐Nd Complexes
Authors: Bi Wei‐Yu , Lü Xing‐Qiang , Chai Wen‐Li , Song Ji‐Rong , Wong Wai‐Kwok , Yang Xiao‐Ping , Jones Richard A.
Published: July 2008

Two heterobimetallic Zn‐Nd phenylene‐bridged Schiff‐base ligands complexes [ZnNdL1(Py)(NO3)3] (1) and [ZnL2Nd(Py)(NO3)3]·MeCN (2) (Py = pyridine, H2L1 = N,N′‐bis‐ (3‐methoxy‐salicylidene)phenylene‐1,2‐diamine, H2L2= N,N′‐bis‐5‐bromo‐3‐methoxy‐salicylidene)phenylene‐1,2‐diamine) were obtained. Both 1 and 2 were structurally characterized by X‐ray crystallography, and their near‐infrared (NIR) luminescent properties were determined. For the two complexes, the occupation of pyridine at the axial position of 3d Zn2+ ions could effectively prevent luminescent quenching arising from OH‐, NH‐ or CH oscillators of the solvates around the 4f Nd3+ ions, and the heavy‐atom (Br) effect of the Schiff‐base ligands on their NIR luminescent properties is also discussed.
Metal Derivatives of Heterocyclic Thioamides: Synthesis and Crystal Structures of Copper Complexes with 1‐Methyl‐1,3‐imidazoline‐2‐thione and 1,3‐Imidazoline‐2‐thione
Authors: Lobana Tarlok S. , Sharma Renu , Sharma Rekha , Butcher Ray J.
Published: July 2008

Reactions of copper(I) halides (Cl, Br, I) with 1‐methyl‐1, 3‐imidazoline‐2‐thione (mimzSH) in 1 : 2 molar ratio yielded sulfur‐bridged dinuclear [Cu2X2(μ‐S‐mimzSH)2(η1‐S‐mimzSH)2] (X = I, 1, Br, 2; Cl, 3) complexes. Copper(I) iodide with 1,3‐imidazoline‐2‐thione (imzSH2) and Ph3P in 1 : 1 : 1 molar ratio has also formed a sulfur‐bridged dinuclear [Cu2I2(μ‐S‐imzSH2)2(PPh3)2] (4) complex. The central Cu(μ‐S)2Cu cores form parallelograms with unequal Cu–S bond distances {2.324(2), 2.454(3) Å} (1); {2.3118(6), 2.5098(6) Å} (2); {2.3075(4), 2.5218(4) Å} (3); {2.3711(8), 2.4473(8) Å} (4). The Cu···Cu separations, 2.759–2.877Å in complexes 1–3 are much shorter than 3.3446Å in complex 4. The weak intermolecular interactions {H2CH···S# (2); CH···Cl# (3); NH···I# (4)} between dimeric units in complexes 2–4 lead to the formation of linear 1D polymers.
Synthese, Strukturen, NMR‐ und EPR‐Untersuchungen der binuklearen Bis(N,N,N‴,N‴‐tetraisobutyl‐N′,N″‐isophthaloylbis(selenoureato))‐Komplexe des NiII und CuII
Authors: Rodenstein Axel , Griebel Jan , Richter Rainer , Kirmse Reinhard
Published: July 2008

Synthesis, Structures, NMR and EPR Investigations of Binuclear Bis(N,N,N‴,N‴‐tetraisobutyl‐N′,N″‐isophthaloylbis(selenoureato)) Complexes of NiII and CuII

The synthesis of binuclear CuII and NiII complexes of the quadridentate ligand N,N,N‴,N‴‐tetraisobutyl‐N′,N″‐isophthaloylbis(selenourea) and their crystal structures are reported. The complexes crystallize monoclinic, P21/c (Z = 2). In the EPR spectra of the binuclear CuII complex exchange‐coupled CuII‐CuII pairs were observed. In addition the signals of a mononuclear CuII species are observed what will be explained with the assumption of an equilibrium between the binuclear CuII‐complex (CuII‐CuII pairs) and oligomeric complexes with “isolated” CuII ions. Detailed 13C and 77Se NMR investigations on the ligand and the NiII complex allow an exact assignment of all signals of the heteroatoms.
Synthesis and Crystal Structures of Bis(1‐{(E)‐2‐pyridinylmethylidene}‐semicarbazone)iron(II) and ‐copper(II) Diperchlorate Monohydrates
Authors: Garbelini Ellery R. , Hörner Manfredo , Boneberger Behm Mariana , Evans David J. , Nunes Fábio S.
Published: July 2008

The pyridine‐2‐carbaldehyde semicarbazone ligand (HL) reacts with iron(II) and copper(II) perchlorates in boiling ethanol to yield red‐violet [FeII(HL)2](ClO4)2·H2O (1) and light‐green crystals [CuII(HL)2](ClO4)2·H2O (2). The crystals are triclinic with the metal ions in an octahedral environment, coordinated to two nitrogen and one oxygen‐donor atom from HL. Electronic, magnetic and electrochemical properties are presented as well.
Two 1,2,4‐Triazole‐based Zinc(II) Complexes with Aromatic Acid as Coligand: Synthesis, Structure and Fluorescence Properties
Authors: Liu Zhong‐Yi , Wang Xiu‐Guang , Yang En‐Cui , Zhao Xiao‐Jun
Published: July 2008

Two two‐dimensional (2‐D) trz‐based coordination polymers, {[Zn(trz)(mb)]·H2O}n (1) and {[Zn(trz)(ca)]·H2O}n (2) (Htrz = 1,2,4‐triazole, Hmb = 4‐methylbenzoic acid, and Hca = trans‐cinnamic acid), have been synthesized by diffusion method and fully structural characterized by elemental analysis, FT‐IR, single‐crystal X‐ray crystallography, TG and fluorescence spectra. Structural analysis reveals that both complexes exhibit the analogous 2‐D ZnII‐trz layer motif with hydrophobic aromatic rings attached on both sides despite their different crystal system and space group (orthorhombic, Pbca for 1 and monoclinic, P21/c for 2). Interestingly, the discrete water‐dimer and infinite 1‐D water‐chain were observed to be entrapped in the 2‐D layer of 1 and 2, respectively, resulted from the different orientation of lattice water molecules as well as the patterns of hydrogen bonds involved. In addition, their similiar thermal behaviors and fluorescence emissions originated from intraligand electronic transfer were also investigated and compared.
Association of chromosome 9p21 SNPs with cardiovascular phenotypes in morbid obesity using electronic health record data
Authors: Wood G. Craig , Still Christopher D. , Chu Xin , Susek Meghan , Erdman Robert , Hartman Christina , Yeager Stephanie , Blosky Mary Ann , Krum Wanda , Carey David J. , Skelding Kimberly A. , Benotti Peter , Stewart Walter F. , Gerhard Glenn S.
Published: July 2008

Genomic medicine research requires substantial time and resources to obtain phenotype data. The electronic health record offers potential efficiencies in addressing these temporal and economic challenges, but few studies have explored the feasibility of using such data for genetics research. The main objective of this study was to determine the association of two genetic variants located on chromosome 9p21 conferring susceptibility to coronary heart disease and type 2 diabetes with a variety of clinical phenotypes derived from the electronic health record in a population of morbidly obese patients. Data on more than 100 clinical measures including diagnoses, laboratory values, and medications were extracted from the electronic health records of a total of 709 morbidly obese (body mass index (BMI) ≥ 40 kg/m2) patients. Two common single nucleotide polymorphisms located at chromosome 9p21 recently linked to coronary heart disease and type 2 diabetes (McPherson et al. Science 316:1488–1491, 2007; Saxena et al. Science 316:1331–1336, 2007; Scott et al. Science 316:1341-1345, 2007) were genotyped to assess statistical association with clinical phenotypes. Neither the type 2 diabetes variant nor the coronary heart disease variant was related to any expected clinical phenotype, although high-risk type 2 diabetes/coronary heart disease compound genotypes were associated with several coronary heart disease phenotypes. Electronic health records may be efficient sources of data for validation studies of genetic associations.
Wenhua: A crucial academic resource for Chinese classical criticism
Authors: Shuizhao WANG
Published: July 2008

Wenhua is an important genre of Chinese classical literary criticism. Besides the form of collections of tales and notes, as defined in a narrow sense, there are different writing formats of Wenhua, including theoretical monographs, compilations of sources, annotated and commented anthologies, etc. The four types of critical writings emerged simultaneously in the Song dynasty, thus signified the founding of Chinese classical article-logy and then grew in abundance in the Ming and Qing dynasties. They are rich in insights and artistic experience in the aspects of literature-Tao relationship, manner of writing, poetic state of the prose, genre, writing skills and criticism. After the reflection of “May-fourth Movement”, evaluation of the merits of Wenhua is supposed to be more comprehensive and scientific.
Patient led conferences – Who attends, are their expectations met and do they vary in three different countries?
Authors: Zakrzewska Joanna M. , Jorns Teekayu P. , Spatz Amy
Published: July 2008

Objective: To determine the demographics of attendees at three national conferences for trigeminal neuralgia sufferers, to quantify their expectations and determine if they were fulfilled.

Design: A self complete questionnaire was distributed at the start and end of patient led conferences delivered by health care practitioners (HCP).

Participants: 249 sufferers, most of whom were members of their support group.

Setting: National conferences in US, UK and Australia organised by the Trigeminal Neuralgia Associations of the respective countries.

Results: 83% of attendees completed the questionnaire before the conference and 79% returned them at the end. The majority were middle aged females in pain and there was little difference between the three countries. Some attendees were newly diagnosed, others had undergone both medical and surgical therapies. Disability on the graded chronic pain scale was high in 32% of attendees and their expectations centred around increasing their knowledge about the disease and hearing about new treatments. Their expectations were fully met as shown by mean scores of 8 and above (10 being the best). Attendees particularly valued the opportunity to meet expert HCPs (mean 9.4) but also appreciated the opportunity to meet fellow sufferers (mean 8.9). Participants stated that the conference improved their confidence in dealing with their pain (mean 8.1).

Conclusion: Attendees at national conferences of support groups show considerable disability and their major expectations of improving their knowledge and meeting both expert HCPs and fellow sufferers are fulfilled.
Loss of peroxisome function triggers necrosis
Authors: Jungwirth Helmut , Ring Julia , Mayer Tanja , Schauer Alexandra , Büttner Sabrina , Eisenberg Tobias , Carmona-Gutierrez Didac , Kuchler Karl , Madeo Frank
Published: July 2008

Disturbance of peroxisome function can lead to various degenerative diseases during ageing. Here, we show that in yeast deletion of PEX6, encoding a protein involved in a key step of peroxisomal protein import, results in an increased accumulation of reactive oxygen species and an enhanced loss of viability upon acetic acid treatment and during early stationary phase. Cell death of ageing‐like yeast cells lacking PEX6 does not depend on the apoptotic key players Yca1p and Aif1p, but instead shows markers of necrosis. Thus, we conclude that loss of peroxisomal function leads to a form of necrotic cell death.
Endogenous flow of amino acids in the avian ileum as influenced by increasing dietary peptide concentrations
Authors: Ravindran Velmurugu , Morel Patrick C. H. , Rutherfurd Shane M. , Thomas Donald V.
Published: July 2008

The aim of the present study was to establish whether feeding broiler chickens with diets containing increasing dietary peptide concentrations would cause increases in ileal endogenous amino acid flow. The flow of N and most amino acids increased quadratically (P < 0·05 to 0·001) with increasing dietary concentrations of peptides. The exceptions were the flow of threonine, serine, glycine, tyrosine and cystine, which increased linearly (P < 0·001) with dietary peptide levels. Another notable exception to the general trend was the flow of proline, which was significantly higher (P < 0·01) in birds fed the protein-free diet. The amino acid profile of endogenous protein, expressed as proportion of crude protein, indicated that the ratios of threonine, glutamic acid, proline, glycine, leucine, histidine, arginine and cystine were influenced (P < 0·05) with increasing dietary peptide concentrations. In general, compared with the protein-free diet, the ratios of threonine and arginine in endogenous protein were lower (P < 0·05) and those of glutamic acid, glycine and histidine were greater (P < 0·05) in diets with high concentrations of peptides. The ratio of proline was found to decrease (P < 0·05) with increasing dietary peptide concentrations. These changes in the amino acid profile of endogenous protein are probably reflective of changes in the output of one or more of the components of endogenous protein. Overall, the present results demonstrated that increasing dietary peptide concentrations increased the flow of endogenous amino acid flow at the terminal ileum of broiler chickens in a dose-dependent manner and also caused changes in the composition of endogenous protein. The observed changes in endogenous amino flow will influence the maintenance requirements for amino acids and also have implications for the calculation of true digestibility coefficient of feedstuffs.
Survey of subterranean termites (Isoptera: Rhinotermitidae) in a managed silvicultural plantation in Portugal, using a line-intersection method (LIS)
Authors: Nobre T. , Nunes L. , Bignell D.E.
Published: July 2008

Subterranean termites (Reticulitermes grassei) were surveyed over successive seasons in a managed eucalyptus plantation in southeastern Portugal for 26 months. Termite activity in seven diameter categories of lying dead wood was investigated by a modified line intersection method (LIS). Each item sampled was inspected and assessed for termite attack and for general (i.e. fungal) decay status using standard protocols. Line intersection is quantitative to the extent that it can link foraging and decay parameters to woody biovolume. It was found that termites selected items with larger diameter, the observed trend showing an exponential character with greater termite attack as diameter increased. Attack by termites was positively associated with prior decay by fungi. A clear positive relationship was shown between rainfall and total woody biovolume containing live termites, underlining the importance of moisture for termite activity. Subterranean termites appeared to be important wood decomposers in the woodland studied, with an average of 30% of lying dead wood branches showing signs of termite attack.
NATIONALITÉ ET CITOYENNETÉ EN AFRIQUE OCCIDENTALE FRANÇAIS: ORIGINAIRES
ET CITOYENS DANS LE SÉNÉGAL COLONIAL
Authors: COQUERY-VIDROVITCH CATHERINE
Published: July 2008

The French in West Africa remained deeply ambivalent in regard to
applying naturalization policies to their African subjects. Applying a
distinction between ‘citizenship’ and ‘nationality’, this article traces the
history of French colonial policy from 1789 through decolonization in the
1950s. Apart from the originaires of the four
communes of Senegal, who had ill-defined rights of French citizenship
without ever being considered French nationals, naturalization policy in
West Africa became so restrictive that no more than sixteen individuals were
granted French citizenship each year between 1935 and 1949. This article
uses dossiers of naturalization cases from French West Africa.
ECOLOGY AND POWER IN THE PERIPHERY OF MAASINA: THE CASE OF THE HAYRE IN
THE NINETEENTH CENTURY
Authors: DE BRUIJN MIRJAM , VAN DIJK HAN
Published: July 2008

This article explores political tensions between successive
nineteenth-century rulers of the inland delta of the Niger in central Mali
(the Fulbe Diina of Hamdullahi and the Futanke successors of al-Hajj Umar)
and the pastoral interests of the Fulbe chiefdoms on their eastern
periphery, in a region known as the Hayre. A close study of changing forms
of local governance and natural resource management demonstrates that
although different strategies were employed by the Fulbe and Futanke states
to control the Hayre, the internal dynamics of the region can only partly be
explained by the influence of these central powers.
CONVERSION TO ISLAM: MILITARY RECRUITMENT AND GENERATIONAL CONFLICT IN A SEREER-SAFÈN VILLAGE (BANDIA), 1920–38
Authors: SEARING JAMES F.
Published: July 2008

The Sereer-Safèn are a minority population in a predominantly Wolof and Muslim region. During the colonial period the Safèn were ruled by Wolof chiefs, who treated them as a conquered population. Until the First World War, Safèn resistance was based on preserving a separate religious and ethnic identity, symbolized by the village shrine and matrilineal descent. Conversion to Islam had its roots in the crisis created by military recruitment. When the Safèn were forced to give soldiers to the French, ‘maternal uncles’ used their authority over their ‘nephews’ to recruit soldiers. Today this act is remembered as a ‘betrayal’ that called into question the legitimacy of the matrilineal system of labor and inheritance. Conversion to Islam has been studied by focusing on long-term Islamization rather than the moment of conversion. Oral testimony from converts emphasizes changes in behavior, funeral rites, inheritance and patterns of labor and power in the village community.
NEO-TRADITIONALISM AND THE LIMITS OF INVENTION IN BRITISH COLONIAL AFRICA
Authors: SPEAR THOMAS
Published: July 2008

Exploring a range of studies regarding the ‘invention of tradition’, the ‘making of customary law’ and the ‘creation of tribalism’ since the 1980s, this survey article argues that the case for colonial invention has often overstated colonial power and ability to manipulate African institutions to establish hegemony. Rather, tradition was a complex discourse in which people continually reinterpreted the lessons of the past in the context of the present. Colonial power was limited by chiefs' obligation to ensure community well-being to maintain the legitimacy on which colonial authorities depended. And ethnicity reflected longstanding local political, cultural and historical conditions in the changing contexts of colonial rule. None of these institutions were easily fabricated or manipulated, and colonial dependence on them often limited colonial power as much as facilitating it.
JOHN FAGE A PERSONAL RECOLLECTION
Authors: OLIVER ROLAND
Published: July 2008

JOHN FAGE and I met first in Cambridge in 1948 as graduate students at Cambridge University, each researching on topics in the history of the colonial period in Africa. Thereafter our ways parted. He became the first full-time history teacher at the recently founded University College of the Gold Coast. I went to the School of Oriental and African Studies in London, where my initial duty was to investigate what could be recovered of the pre-colonial history of East Africa that might be brought within the scope of academic study. We met next in 1952, when a London publisher suggested that we might join in writing a History of Africa in two volumes designed for the academic market. Following this initiative, we spent a fortnight of that summer, together with our wives and children, at my house in Buckinghamshire to discuss the possibilities, and this proved to be the beginning of a close professional collaboration which was to last for more than thirty-five years.
The recovery of recombinant inbreds outyielding the hybrid in tomato
Authors: CHRISTAKIS P. A. , FASOULAS A. C.
Published: July 2008

Publications commenting on the possibility of fixing heterosis and the possibility to transgress heterosis through partition of crop yield into genetic components have prompted us to reconsider our views on the relative importance of hybrid versus inbred vigour. The three genetic components of crop yield, all assessed in the absence of competition, are: (1) yield per plant assessed by the progeny mean, (2) tolerance to stresses assessed by the progeny standardized mean, and (3) responsiveness to inputs assessed by the progeny standardized selection differential. Although fixation of heterosis using the top commercial tomato hybrids was based only on the first genetic component of crop yield and quality, inbreds outyielding the original hybrid were obtained relatively easily. The results indicated that selection for homozygote superiority on the basis of the three genetic components of crop yield and quality, would lead to the development of tomato inbreds outperforming the hybrids.
The ability of wheat cultivars to withstand drought in UK conditions: resource capture
Authors: FOULKES M. J. , SCOTT the late R. K. , SYLVESTER-BRADLEY R.
Published: July 2008

Experiments in three dry seasons (1993/94, 1994/95, 1995/96) on a loamy medium sand at ADAS Gleadthorpe, Nottinghamshire, England tested responses of green area, radiation interception, water uptake and above-ground dry matter growth of six wheat cultivars to irrigation. Cultivars differing in date of introduction (Haven 1987, Maris Huntsman 1969, Mercia 1983, Rialto 1991, Riband 1985 and Soissons 1989) were chosen for contrast in flowering time and maximum green area. Maximum soil moisture deficit (SMD) exceeded 140 mm in all years, with large deficits (> 75 mm) from early June in 1994 and more prolonged large deficits in 1995 and 1996. Restricted water availability first affected canopy expansion at a SMD of 74 mm (50% available water capacity; AW), and canopy senescence at 95 mm (64% AW). Decreases in biomass at harvest were larger with prolonged droughts in 1995 and 1996 (424–562 g/m2) than in 1994 (222 g/m2). Compared in the two driest years, 1995 and 1996, the decrease in biomass was greater in Haven (599 g/m2) than in Maris Huntsman (420 g/m2) (P < 0·05). The better drought resistance of Maris Huntsman appeared to arise through its greater water use efficiency (WUE); 6·2 cf. 5·5–5·7 g/m2/mm. The susceptibility of Haven to drought was possibly due to restricted water uptake, depression of radiation use efficiency (RUE) and accelerated senescence. The cultivars differed in flowering by up to 9 days but date of flowering correlated poorly with biomass response to irrigation. Early flowering was, however, correlated with favourable distribution of seasonal water use with respect to the grain filling period. The maximum green area index (GAI) of cultivars varied from 4·4 to 5·3 (P < 0·01), but differences were countered by shifts in the extinction coefficient (K), such that season-long radiation interception varied little. Green area index maxima did not therefore relate to the pattern of growth or water use, and they were correlated poorly with the biomass responses. Cultivars did not differ in their maximum depth of water extraction; they all extracted water to 1·65 m depth in each year. It is concluded that early flowering and high WUE might offer scope for improving drought resistance in the UK's temperate climate, but that small maximum GAI seems less useful.
The effects of Gliricidia supplementation on intake and digestion of a Digitaria decumbens hay by Black-belly sheep
Authors: ARCHIMEDE H. , DULORME M. , TOURNEBIZE R. , SAMINADIN G. , PERIACARPIN F. , XANDE A.
Published: July 2008

The research was carried out at the animal experimental station of the National Agricultural Research Institute of the French West Indies (Guadeloupe) in 1999. Effects on intake and digestion by sheep of addition of Gliricidia leaves to a diet of 35-day-old Digitaria decumbens (pangola) hay, have been studied. In a first trial (a 4×4 Latin Square design), four rams were fed four diets: hay (G0); hay plus 1300 g of Gliricidia (G0·25), hay plus 2600 g of Gliricidia (G0·50), hay plus 3900 g of Gliricidia (G0·75). Total dry matter intake (DM), hay and Gliricidia intake, total tract and rumen digestibility of DM and its components, microbial and total nitrogen flows were estimated. In a second trial (a 2×2 Latin Square design), the same animals received hay (G0) or Gliricidia (G1·00) ad libitum to estimate the rumen turnover of pangola and Gliricidia fibrous particle. Neutral detergent fibre and crude protein content of the Digitaria decumbens hay and Gliricidia were 746 and 51, 458 and 198 g/kg dry matter respectively. Total dry matter intake (DM) varied from 42·7 to 76 g DM/kg LW0·75 from G0 to G0·75. The rate of substitution of pangola by Gliricidia (decrease of pangola intake for one unit Gliricidia consumed) was 233 g/kg. The digestibility of cell-wall linearly decreased with increasing level of Gliricidia in the diet. No digestive interaction was registered in the mixed diets. The total nitrogen and microbial nitrogen duodenal flows increased with the level of Gliricidia in the diet. The rumen turnover of fibrous particles of Gliricidia was double that of pangola. The incorporation of Gliricidia in diets increases their nutritive value by higher intake and intestinal nitrogen duodenal flows, but no positive digestive interaction was observed between pangola hay and Gliricidia leaves.
Comparative efficiency of three selection methods in Dactylis glomerata L. and Agropyron cristatum L.
Authors: ABRAHAM E. M. , FASOULAS A. C.
Published: July 2008

Two populations, one non-improved of Dactylis glomerata and one improved of Agropyron cristatum were selected in an isolated spaced plant environment (80 cm) by three selection procedures: (1) Mass honeycomb selection (MHS), (2) pedigree honeycomb selection (PHS) and (3) pedigree honeycomb selection-combined criterion (PHS-CC). The third procedure is a between-families selection based on increased family mean and reduced family coefficient of variation (CV). Response to selection assessed in sward trials in the first and second harvest year was effective for the three procedures, which ranked PHS-CC > PHS > MHS. Evaluation was based on consistent efficiency as measured by both cloned and half-sib families. The precision of assessing progeny performance under sward conditions on the basis of single plant evaluation in the isolation environment, increased with a reduction in competition among plants, the use of moving-ring selection, and the application of high selection pressures (1·6%). The efficiency of selection between unimproved families increased when families were selected concurrently for high family mean and reduced family coefficient of variation.
The impact of modern farming practices on soil fertility and quality in England and Wales
Authors: WEBB J. , LOVELAND P. J. , CHAMBERS B. J. , MITCHELL R. , GARWOOD T.
Published: July 2008

Data are presented on the effects of modern farming practices on soil as an agricultural resource in England and Wales (E&W), namely: nutrient status, pH, soil organic carbon (SOC), heavy metal concentrations, and on soil erosion risk. Fertilizer-N inputs to tillage (arable) and grassland soils increased from 84 and 65 kg/ha N in 1969 to 151 and 120 kg/ha N, respectively, in 1997. The estimated N surplus (inputs less outputs) increased from 84 and 96 kg/ha N to 102 and 154 kg/ha N, respectively, over the same time. Phosphorus inputs to tillage (mean 37 kg/ha P) and grassland (mean 21 kg/ha P) changed little over the period. However, P surpluses decreased from 25 kg/ha P in 1969 to 15 kg/ha P in 1997 on tillage land (largely as a result of greater P offtakes), and from 20 to 17 kg/ha P in 1997 on grassland (largely because of a small decrease in fertilizer P). The cumulative tillage land soil P surplus was c. 580 kg/ha P, and was estimated to increase topsoil total P concentrations by c. 170 mg/kg P and Olsen-extractable soil P by c. 26 mg/l P. The mean annual P surplus for grassland was 18 kg/ha P which, over the study period, added c. 427 kg/ha P to the soil, an increase in topsoil total P of c. 214 mg/kg P, and in Olsen-extractable P of 19 mg/l P.

Concentrations of SOC in some soils have decreased between 1980 and 1995, especially where soils have been ploughed out of grassland and on lowland organic and peaty soils in tillage. The mean SOC of soils in arable/ley cultivation in 1980 was 3·4% and 2·8% in 1995.

The proportion of arable soils with pH < 6·0 decreased from 10% in 1969–73 to 4% in 1990–93, reflecting the better targeting of lime inputs. In contrast, the proportion of grassland soils with pH < 6·0 increased from 39% in 1969–73 to 56% in 1990–93.

Although there were statistically significant changes in the mean soil concentrations of Cd, Cu, Ni, Pb and Zn between 1980 and 1995, many of the changes were small in absolute terms. Hence, there was little evidence of marked or systematic changes in topsoil total heavy metal concentrations that could not be explained by factors other than increased pollutant loadings.

Over the next 50 years or so, the threat from soil erosion to crop productivity will be greatest on shallow soils ([les ] c. 0·3 m depth), mostly over chalk and sandstone as further removal of soil will lead to increased drought stress. Provided that nutrient supplies are maintained, the evidence is that losses in arable crops on eroded soils would range between 2% and 8% of current yields.

Thus, within the limitations of the data available, both in time and space, we found little evidence that most soils in E&W cannot continue to support modern farming practices, and the associated crop and animal outputs, given appropriate inputs of nutrients and an adequate degree of crop protection.
Effect of dietary condensed tannins on gastrointestinal nematodes
Authors: BUTTER N. L. , DAWSON J. M. , WAKELIN D. , BUTTERY P. J.
Published: July 2008

It has been previously shown in this laboratory that feeding a model condensed tannin, quebracho tannin, reduces the small intestinal nematode burden in sheep and rats. The aim of the current programme was to determine whether this occurs through direct toxicity against the parasites. Both in vivo and in vitro studies were conducted. The first study compared the effect of dietary quebracho tannin (40 g/kg) on the establishment of the parasitic nematodes Nippostrongylus brasiliensis and Trichinella spiralis in the rat small intestine. The burden of N. brasiliensis, which, although closely associated with the mucosa, actually dwells within the small intestinal lumen, was significantly reduced (P<0·001) by dietary quebracho tannin. In contrast, T. spiralis, which penetrates into the small intestinal mucosa, was unaffected (>0·05) by the dietary inclusion of quebracho tannin. The second study involved monitoring the survival of adult N. brasiliensis and T. spiralis when incubated in vitro in varying concentrations of quebracho tannin in Hanks’ balanced salt solution. The survival of N. brasiliensis was compromised at concentrations as low as 0·01% (w/v) quebracho tannin but improved with the addition of 0·1% (w/v) polyethylene glycol, which binds to, and inactivates, tannin. T. spiralis was similarly affected, but much more rapidly. These results suggest that dietary quebracho tannin may reduce nematode worm burdens through a toxic effect that requires direct contact between parasite and tannin. This raises the possibility that feeding locally available plant material containing condensed tannins may be an alternative method for controlling parasite infections, especially in areas such as the tropics and subtropics.
Field activities and blood profile of pregnant South African indigenous goats after receiving dihydroxy pyridone-degrading rumen bacteria and grazing Leucaena leucocephala-grass or natural pastures
Authors: AKINGBADE A. A. , NSAHLAI I. V. , MORRIS C. D. , IJI P. A.
Published: July 2008

Twenty-four multiparous female South African indigenous goats were used. Once a week during the 2nd (weeks 8, 11 and 14) and 3rd (weeks 18, 19 and 20) trimesters, between 08·00 and 15·00 h, four females per treatment were randomly selected and observed every 1 min for time spent grazing, browsing, ruminating and idling. Blood samples were taken once a week during the 2nd (weeks 8, 11 and 14) and 3rd (weeks 18, 19, 20 and 21) trimesters for measurements of some mineral elements and protein metabolites. Goats on natural pasture (NP) grazed 54·8 min (P<0·001) more and browsed 53 min (P<0·001) less than goats on Leucaena leucocephala-grass pasture (LGP) during the 2nd trimester. During the 3rd trimester, goats on NP treatments grazed and idled more (24·7 min, P = 0·004; 15·8 min, P = 0·044, respectively) but ruminated less (−24·1 min, P<0·001) than LGP goats. Time allotted to each field activity by the goats on both treatments within trimester seemed to be dependent on forage species composition while activity between trimesters was possibly influenced by seasons, plant type, herbage quantity, environment and quality, and changes in stage of gestation of the goats. Blood Mg level on NP was higher (P = 0·051) than on LGP during the 2nd trimester while blood Cu and albumin contents on LGP were significantly higher (P = 0·029 and 0·022, respectively) than on NP during the 3rd trimester. Furthermore, blood concentrations of the haematological parameters (except serum protein) on both treatments were within the normal range for goats in the tropics and subtropics and perhaps explain the absence of mineral and nutrient deficiency symptoms. The absence of visible symptoms of mineral deficiency and mimosine toxicity in LGP goats can be attributed to the transfer of DHP-degrading rumen bacteria. The bacteria effectively detoxified mimosine and its metabolites, thereby overcoming chelating tendency of mimosine and its metabolites. Mimosine-susceptible pregnant SAIG can be safely grazed on LGP once their rumen is completely colonized by the DHP-degrading rumen bacteria (Synergistes jonesii).
The effects of fungicides on rate and duration of grain filling in winter wheat in relation to maintenance of flag leaf green area
Authors: DIMMOCK J. P. R. E. , GOODING M. J.
Published: July 2008

Three field experiments were conducted on sandy-loam soils comparing the effects of triazole, strobilurin and oxazolidinedione fungicides applied at flag leaf emergence and again at ear emergence to wheat between 1998 and 2000. Cultivars Hereward and Consort were included in all 3 years, Cockpit in 1999 and 2000 and Charger in 1999. Foliar disease, green area of the flag leaf, grain weight and moisture content were assessed weekly during grain filling and senescence. Grain yield, 1000 grain weight (TGW) and specific weights were measured at harvest maturity. Septoria tritici was the dominant disease in all cultivars except Cockpit, where Puccinia striiformis caused most damage. Consort was more affected than Hereward by S. tritici in all years. Effects of fungicides on disease control were usually reflected in green flag leaf area duration (GFLAD), with large gains in Consort and Cockpit. In 2000, however, fungicides increased GFLAD of Hereward and Consort by similar amounts. Apical grains had smaller water content than medially placed grains. Maximum water content was positively influenced by fungicides where significant disease was controlled before maximum grain weight had been attained. Grain weight in Hereward was less affected than other cultivars by fungicides in both positions. Grain filling rates varied between cultivar and ear position by inconsistent and small amounts, but large and significant gains from fungicide treatment were made in grain filling periods. These varied from 0·16 days per day GFLAD in Hereward to 0·69 days per day GFLAD in Consort in apical grains in 2000. Gains in GFLAD were associated with increased yield, TGW and specific weight, but these relationships varied with cultivar. Increases in GFLAD by fungicide in Hereward in 2000 occurred much later relative to grain filling and thus after the time of maximum grain water content, resulting in smaller gains in filling duration, yield, TGW and specific weight than that seen in Consort. There was no evidence of differing relationships between GFLAD and yield for the different fungicide groups used in these experiments.
The effects of seed rate and row spacing on light interception, dry matter accumulation and seed yield, in non-dwarf and dwarf genotypes of autumn-sown determinate white lupins (Lupinus albus) in north-west Europe
Authors: SHIELD I. F. , SCOTT T. , HUYGHE C. , BRUNEAU M. , PARISSEAUX B. , PAPINEAU J. , HARZIC N. , STEVENSON H. J. , LEACH J. E.
Published: July 2008

Two non-dwarf and two dwarf, autumn-sown determinate genotypes of white lupin (Lupinus albus L.) were sown at three sites in north-west Europe in the crop years, 1995–96, 1996–97 and 1997–98. Fully factorial experimental designs were used to analyse all combinations of genotype, seed rate and row spacing. Canopy expansion, expressed as the percentage of Photosynthetically Active Radiation (PAR) intercepted, and above ground dry matter (DM) accumulation were measured at frequent intervals during the main growing season at Rothamsted in the UK and Lusignan in France. The data from Rothamsted were used to derive models for the two processes, which were compared to the data from Lusignan, France.

Crops with more than 23 plants/m2, 25 main stem leaves per plant or 1400 leaves/m2 were able to intercept more than 80% of the incident PAR. There were small differences in canopy expansion between genotypes. The non-dwarf genotypes began expansion slightly earlier (100–150 °Cd or thermal time in °Cdays, base temperature = 3 °C) than the dwarf genotypes. Crops sown on rows wider than 40 cm apart or with low plant densities (less than 23 plants/m2) were also slower to expand the canopy and intercept the PAR.

The maximum quantity of dry matter accumulated by a genotype in the season (476–1044 g/m2) was related by a conversion efficiency (e) to the cumulative quantity of PAR intercepted. Values of e were generally in the range 0·92–1·65 g DM/MJ PAR during the early part of the growing season, which was comparable with other work on temperate-zone grain legumes. The non-dwarf genotype Ludet achieved an unusually large value of e (3·13 g DM/MJ PAR) and accumulated 1355 g DM/m2 at Lusignan in 1998. Late season drought in 1995–96 at Rothamsted produced some low values of e (0·75 and 0·88 g DM/MJ PAR).

The seed yield was not related to the quantity of dry matter accumulated as harvest index varied from 22·3% to 49·7%. Maximum seed yield (4·54 t/ha) was produced from a low plant density (15·9 plants/m2). Mutual shading, caused by any combination of high plant densities, large numbers of leaves per plant or sowing on wide rows (>40 cm; at high plant densities within the rows) appeared to limit seed yield potential.
Effect of short transport during di-oestrus and pro-oestrus on cortisol levels and oestrous behaviour of sheep
Authors: ORIHUELA AGUSTÍN , SÁNCHEZ-MEJORADA HÉCTOR , TOLEDO MARTÍN
Published: July 2008

Two experiments were conducted to evaluate the effect of short transport stress on ewes during di-oestrus and pro-oestrus. In Experiment 1, intra-vaginal sponges containing fluorogestone acetate were inserted into ewes for a period of 12 days. A gonadotrophin (PMSG) injection was given at the time of sponge withdrawal to induce oestrous. To dissociate the possible effect of PMSG during pro-oestrus, a second experiment was designed in which prostaglandin was used as the oestrous induction factor. Ewes in both experiments were subjected to 30 min of transport by truck. In addition, oestrous behaviour and serum cortisol concentration were evaluated. Control groups consisted of un-transported ewes. In both experiments, cortisol concentration was greater (P <0·01) in transported than in un-transported animals. No difference (P> 0·05) was found between moving the ewes during pro-oestrous or di-oestrus (0·30±0·03 v. 0·53±0·18 ng/ml and 3·88±0·97 v. 2·94±0·73 ng/ml in Experiment 1 and 2 respectively). The number of ewes detected in oestrous was similar (P>0·05) among those stressed during di-oestrus, pro-oestrus or un-transported animals within each experiment (66, 47 and 42% respectively in Experiment 1 and 96·7 in all situations in Experiment 2). In general, higher cortisol concentration and more ewes displaying oestrous behaviour were detected in Experiment 2. It was concluded that under the conditions of these experiments, no difference was found in the proportion of ewes displaying oestrus regardless of the phase of the oestrous cycle in which they were transported.
Performance, heterosis and heritability in selected tropical maize single, double and three-way cross hybrids
Authors: SALEH G. B. , ABDULLAH D. , ANUAR A. R.
Published: July 2008

A series of tropical maize hybrids, involving 10 single, four double and four three-way crosses were evaluated with their parental inbred lines and three control varieties, at Universiti Putra Malaysia, Serdang, Malaysia, in a randomized complete block design, with three replications. The objectives were to identify hybrids superior for yield, yield components and other agronomic traits, to estimate heterosis revealed by the hybrids, and to estimate broad-sense heritability for important characters in the populations. The hybrids were found to vary highly for grain yield and most other traits measured. High estimates of heterosis were shown by grain yield, ear weight and grain weight per ear, moderate for plant and ear heights, shelling percentage, ear diameter, number of kernel rows per ear, number of kernels per ear row and 100-grain weight. The hybrids flowered and matured earlier than their respective inbred parents. Estimates of broad-sense heritability also varied with characters. Moderate heritability was shown for grain yield indicating a substantial amount of genetic variation in this population of hybrids. Low and negligible heritability for days to silking and 100-grain weight indicate that these traits were very much influenced by environmental factors. Based on the overall performance of the hybrids, the single cross, SC-2, the double cross, DC-11 and the three-way cross, TWC-15, were found to have high potential. No obvious differences were observed in performance among the three categories of hybrids, the single, double and three-way crosses.
Spatial and seasonal distribution of ascidians in a semi-enclosed basin of the Mediterranean Sea
Authors: Mastrototaro F. , D'Onghia G. , Tursi A.
Published: July 2008

A total of 25 species of ascidians were collected in the Mar Piccolo of Taranto, a semi-enclosed Mediterranean basin. Three are non-indigenous for the Mediterranean Sea: Microcosmus squamiger, Polyandrocarpa zorritensis and Distaplia bermudensis. The substrate features, season and depth affect the distribution of ascidians in the study area. Some species, such as Pyura dura and Pyura microcosmus, were found only on artificial substrates, while Ascidiella aspersa was almost exclusively recovered on natural bottoms. Seasonal variation in the ascidian distribution and abundance seems to be due mainly to their biological cycles, larval recruitment and adaptation. During the autumn and winter the most abundant species were Clavelina phlegraea and Ciona intestinalis, while A.aspersa was particularly abundant during spring. Depth and more directly light intensity play an important role in ascidian distribution. In the upper few metres the shallow-water species Polyandrocarpa zorritensis was abundant due to its photopositive larvae. Even though the distribution and abundance changed significantly between substrates, seasons and depths, the most abundant species in the Mar Piccolo of Taranto were Clavelina phlegraea, Ciona intestinalis and Styela plicata all of which are able to tolerate the variations in environmental conditions, low rate of water renewal and continuous silting of this semi-enclosed sea. Assuming the role that the above mentioned species have as marine pollution indicators and the abundance recorded for some of them, a high degree of environmental stress can be confirmed for the Mar Piccolo of Taranto. A comparative list of the ascidians recorded in this and previous studies is also reported.
Variation in migratory history of Japanese eels, Anguilla japonica, collected in the northernmost part of its distribution
Authors: Arai Takaomi , Kotake Aya , Ohji Madoka
Published: July 2008

In order to examine the variation of migratory histories in the Japanese eel, Anguilla japonica, we measured otolith strontium (Sr) and calcium (Ca) concentrations by X-ray electron microprobe analysis in A. japonica collected in a coastal brackish water lake in the northernmost part of its distribution. Two migratory types that were categorized as river eels and estuarine eels were found. Estuarine eels were dominant (85%), while ordinary diadromous eels that had entered the freshwater habitat made up only 15% of the population. The low proportion of river eels suggested that the estuarine eels that inhabit the nearby coastal areas might make a larger reproductive contribution to the next generation in this area. There was no significant difference in growth between the river and estuarine eels, which suggested that the limited carrying capacity of the adjacent river and geographical features might be more effective in determining the habitat use of the Japanese eel than the genetic feature and food abundance at the northern edge of its distribution.