bluuebunny/crossref_metadata_2025 huggingface dataset:
APOBEC3G: an intracellular centurion
Authors: Chiu Ya-Lin , Greene Warner C
Published: November 2008

The intrinsic antiretroviral factor APOBEC3G (A3G) is highly active against HIV-1 and other retroviruses. In different cell types, A3G is expressed in high-molecular-mass (HMM) RNA–protein complexes or low-molecular-mass (LMM) forms displaying different biological activities. In resting CD4 T cells, a LMM form of A3G potently restricts HIV-1 infection soon after virion entry. However, when T cells are activated, LMM A3G is recruited into HMM complexes that include Staufen-containing RNA granules. These complexes are probably nucleated by the induced expression of Alu/hY retroelement RNAs that accompany T-cell activation. HMM A3G sequesters these retroelement RNAs away from the nuclear long interspersed nuclear element-derived enzymes required for Alu/hY retrotransposition. Human immunodeficiency virus (HIV) exploits this ‘window of opportunity’ provided by the loss of LMM A3G in activated CD4 T cells to productively infect these cells. During HIV virion formation, newly synthesized LMM A3G is preferentially encapsidated but only under conditions where Vif is absent and thus not able to target A3G for proteasome-mediated degradation. Together, these findings highlight the discrete functions of the different forms of A3G. LMM A3G opposes the external threat posed by exogenous retroviruses, while HMM A3G complexes oppose the internal threat posed by the retrotransposition of select types of retroelements.
Shhh! Silencing by microRNA-155
Authors: Teng Grace , Papavasiliou F. Nina
Published: November 2008

Small RNAs mediate a diverse pot-pourri of post-transcriptional silencing mechanisms, ranging from ‘classical’ RNA interference (RNAi), to gene repression by microRNAs (miRNAs), to maintenance of genomic stability by repeat-associated small RNAs. Here, we review recent findings on the function of miR-155, particularly its roles in mammalian innate and adaptive immunity, viral infection and oncogenesis.
Negative modulation of the chicken infectious anemia virus promoter by COUP-TF1 and an E box-like element at the transcription start site binding δEF1
Authors: Miller Myrna M. , Jarosinski Keith W. , Schat Karel A.
Published: November 2008

Expression of enhanced green fluorescent protein (EGFP) under control of the promoter-enhancer of chicken infectious anemia virus (CAV) is increased in an oestrogen receptor-enhanced cell line when treated with oestrogen and the promoter-enhancer binds unidentified proteins that recognize a consensus oestrogen response element (ERE). Co-transfection assays with the CAV promoter and the nuclear receptor chicken ovalbumin upstream promoter transcription factor 1 (COUP-TF1) showed that expression of EGFP was decreased by 50 to 60 % in DF-1 and LMH cells. The CAV promoter that included sequences at and downstream of the transcription start point had less expression than a short promoter construct. Mutation of a putative E box at this site restored expression levels. Electromobility shift assays showed that the transcription regulator delta-EF1 (δEF1) binds to this E box region. These findings indicate that the CAV promoter activity can be affected directly or indirectly by COUP-TF1 andδEF1.
A DNA-launched reverse genetics system for rabbit hemorrhagic disease virus reveals that the VP2 protein is not essential for virus infectivity
Authors: Liu Guangqing , Ni Zheng , Yun Tao , Yu Bin , Chen Liu , Zhao Wei , Hua Jionggang , Chen Jianping
Published: November 2008

Rabbit hemorrhagic disease virus (RHDV), a member of the family Caliciviridae comprising positive-stranded RNA viruses, is a highly virulent pathogen of rabbits. Until recently, studies into the molecular mechanisms of RHDV replication and pathogenesis have been hindered by the lack of an in vitro culture system and reverse genetics. This study describes the generation of a DNA-based reverse genetics system for RHDV and the subsequent investigation of the biological role of the RHDV VP2 protein. The full-length RHDV genome was assembled as a single cDNA clone and placed under the control of the eukaryotic human cytomegalovirus promoter. Transfection of cells with the DNA clone resulted in a clear cytopathic effect and the generation of infectious progeny virions. The reconstituted virus was stable and grew to titres similar to that of the parental virus. Although previous reports have suggested that the minor structural protein (VP2) of other caliciviruses is essential for the production of infectious virions, using the DNA-launch-based RHDV reverse genetics system described here it was demonstrated that VP2 is not essential for RHDV infectivity. Transfection of cells with a cDNA clone of RHDV lacking VP2 resulted in the generation of infectious virions. These studies indicate that the presence of VP2 could reduce the replication of RHDV, suggesting that it may play a regulatory role in the life cycle of RHDV.
In vitro amplification of PrPSc derived from the brain and blood of sheep infected with scrapie
Authors: Thorne Leigh , Terry Linda A.
Published: November 2008

Scrapie is a fatal, naturally transmissible, neurodegenerative prion disease that affects sheep and goats and is characterized by the accumulation of a misfolded protein, PrPSc, converted from host-encoded PrPc, in the central nervous system of affected animals. Highly efficientin vitroconversion of host PrPcto PrPSchas been achieved in models of scrapie and in natural prion diseases by protein misfolding cyclic amplification (PMCA). Here, we demonstrate amplification, by serial PMCA, of PrPScfrom individual sources of scrapie-infected sheep. Efficiency of amplification was affected by the pairing of the source of PrPScwith the control brain substrate of different genotypes of PrP. In line with previous studies, efficiency of amplification was greatly enhanced with the addition of a synthetic polyanion, polyadenylic acid (PolyA), facilitating rapid detection of low levels of PrPScfrom body fluids such as blood. To this end PrPScwas amplified, in a 3 day PMCA assay, from blood leukocyte preparations from VRQ/VRQ scrapie-affected sheep at clinical end point. While PolyA-assisted PMCA resulted in spontaneous conversion of PrPc, we were able to distinguish blood samples from unaffected and affected sheep under controlled conditions. This study demonstrates that highly efficient amplification of PrPSccan be achieved for ovine scrapie from both brain and blood from naturally infected sheep and shows potential applications for improvements in current diagnostics and pre-mortem testing.
Vaccinia virus strain NYVAC induces substantially lower and qualitatively different human antibody responses compared with strains Lister and Dryvax
Authors: Midgley Claire M. , Putz Mike M. , Weber Jonathan N. , Smith Geoffrey L.
Published: November 2008

The antibody responses elicited by immunization of humans with vaccinia virus (VACV) strains Lister, Dryvax and NYVAC have been determined and compared. Neutralizing antibodies against intracellular mature virus (IMV) and extracellular enveloped virus (EEV), and binding antibody titres (ELISA) against the EEV protein B5, the IMV proteins A27 and H3, and VACV-infected cell lysate were measured. Lister and Dryvax induced broadly similar antibody titres, consistent with the fact that these vaccines each protected against smallpox. In contrast, antibody titres induced by NYVAC were significantly lower than those induced by both Lister and Dryvax. Moreover, there were qualitative differences with NYVAC-immunized subjects failing to induce A27-specific antibodies. These observations suggest that although NYVAC is a safer VACV strain, it does not induce an optimal VACV-specific antibody response. However, NYVAC strains engineered to express antigens from other pathogens remain promising candidate vaccines for immunization against other diseases.
Sialoadhesin and CD163 join forces during entry of the porcine reproductive and respiratory syndrome virus
Authors: Van Gorp Hanne , Van Breedam Wander , Delputte Peter L. , Nauwynck Hans J.
Published: November 2008

The porcine reproductive and respiratory syndrome virus (PRRSV) shows a restricted tropism for subsets of porcine macrophagesin vivo. To date, two PRRSV receptors have been identified on primary macrophages, heparan sulphate for binding and sialoadhesin for binding and internalization. However, additional factors are needed because the expression of both receptors in non-permissive cells results in virus internalization but not in virus uncoating and productive infection. Recently, CD163 was described as a PRRSV receptor on Marc-145 cells that renders non-permissive cells susceptible to PRRSV. Therefore, the potential role of CD163 in PRRSV entry in macrophages and its potential interplay with sialoadhesin were studied. Incubation of macrophages at 37 °C with either sialoadhesin- or CD163-specific antibodies reduced PRRSV infection by up to 75 %, while infection was completely blocked by a combination of both antibodies. When incubated at 4 °C, only sialoadhesin- and not CD163-specific antibodies reduced PRRSV infection. In addition, confocal analysis of PRRSV entry in non-permissive cells expressing only sialoadhesin showed PRRSV internalization but no uncoating. In contrast, when both sialoadhesin and CD163 were expressed, PRRSV was uncoated upon internalization, resulting in productive infection. Virus internalization was not observed when only CD163 was expressed; although, cells became productively infected. Thus, sialoadhesin is confirmed as a PRRSV internalization receptor and CD163 is shown to be involved in PRRSV entry, probably during uncoating. Co-expression of recombinant sialoadhesin and CD163 in non-permissive cells increased virus production 10–100 times compared with cells expressing only CD163, sustaining the requirement of both for efficient PRRSV infection.
Effects of the ligand sequence modifications on the retargeted transduction by the retroviral vector having a ligand-chimeric Env protein
Authors: Miyakawa Kei , Fujita Rika , Katane Masumi , Kubo Yoshinao , Amanuma Hiroshi
Published: November 2008

There have been various attempts to redirect the cell entry receptor tropism of the murine leukemia virus vectors. We have recently reported the successful retargeting of the ecotropic Moloney murine leukemia virus vector. This vector (S3-D84K) contains a viral envelope (Env) protein into which a full-length (68 aa) stromal cell-derived factor-1alpha (SDF-1α) was inserted at Pro-79. The S3-D84K vector transduces a certain human cell line through the CXC chemokine receptor 4 (CXCR4) at a titre of about 104 c.f.u. ml−1. Here, the S3-D84K vector was found to transduce another human cell line through CXCR4 with a titre close to 106 c.f.u. ml−1. The SDF-1α ligand of the S3-D84K Env protein was modified in different ways. In one, C-terminal truncations (by 3–51 aa) with or without a Cys-to-Gly change were performed, and in the other, Cys-to-Ala changes of the disulfide-forming cysteines without truncation were made. Seven truncation and three alanine mutant chimeric Env proteins were examined for virion incorporation, and the retroviral vectors displaying the mutant protein were examined for CXCR4 binding and retargeted transduction. Two mutant vectors showed transduction through CXCR4 with titres not higher than those of the S3-D84K vector, while the other mutant vectors minimally transduced cells through CXCR4 either due to a defect in virion incorporation of the chimeric Env protein or an inability to bind to CXCR4. These results suggest that a full-length sequence that may fold into a distinct domain within the chimeric Env protein is preferable as a targeting ligand.
Structural behaviour of synthetic Co2SiO4 at low temperatures
Authors: Sazonov Andrew , Meven Martin , Hutanu Vladimir , Kaiser Volker , Heger Gernot , Trots Dmytro , Merz Michael
Published: November 2008

Synthetic Co2SiO4 has an olivine structure with isolated SiO4 groups (space group Pnma) and shows magnetic ordering below 50 K. Single-crystal neutron diffraction was applied to determine precise crystal structure parameters at low temperatures. No structural phase transition was revealed in the temperature range 2.5–300 K. Lattice parameters were determined by high-resolution X-ray powder diffraction between 15 and 300 K. There is a clear evidence of an anomalous thermal expansion related to the magnetic phase transition which can be attributed to magnetostriction.
Formability of ABX
3 (X = F, Cl, Br, I) halide perovskites
Authors: Li Chonghea , Lu Xionggang , Ding Weizhong , Feng Liming , Gao Yonghui , Guo Ziming
Published: November 2008

In this study a total of 186 complex halide systems were collected; the formabilities of ABX
3 (X = F, Cl, Br and I) halide perovskites were investigated using the empirical structure map, which was constructed by Goldschmidt's tolerance factor and the octahedral factor. A model for halide perovskite formability was built up. In this model obtained, for all 186 complex halides systems, only one system (CsF–MnF2) without perovskite structure and six systems (RbF–PbF2, CsF–BeF2, KCl–FeCl2, TlI–MnI2, RbI–SnI2, TlI–PbI2) with perovskite structure were wrongly classified, so its predicting accuracy reaches 96%. It is also indicated that both the tolerance factor and the octahedral factor are a necessary but not sufficient condition for ABX
3 halide perovskite formability, and a lowest limit of the octahedral factor exists for halide perovskite formation. This result is consistent with our previous report for ABO3 oxide perovskite, and may be helpful to design novel halide materials with the perovskite structure.
Disorder in crystals of dioxofluorotungstates, (NH4)2WO2F4 and Rb2WO2F4
Authors: Udovenko Anatoly A. , Laptash Natalia M.
Published: November 2008

Dioxotetrafluorotungstates (NH4)2WO2F4 [(I) at 297 K and (II) at 133 K] and Rb2WO2F4 (III) were synthesized in a single-crystal form and their structures were determined by X-ray diffraction. Two independent states of the cis-WO2F4 octahedron are characteristic of static and dynamic disorder in structure (I). Dynamically disordered W2 is displaced from the symmetry axis producing four possible orientations of anion that permits O and F atoms to be identified in separate orientations owing to the inherent differences between W—O and W—F bonding. After the phase transition at lower temperature (201 K), (I) transforms into the twin structure (II) with complete O/F ordering. Structure (III) is characterized by full O/F static disorder without any phase transitions at lower temperature.
Structural characterization of RE10W22O81 rare-earth tungstates (RE = Ce, Nd)
Authors: Barker Rosemary S. , Radosavljevic Evans Ivana
Published: November 2008

The single-crystal diffraction study of Ce10W22O81 and powder X-ray diffraction (XRD) experiments on Ce10W22O81 and Nd10W22O81 show that the true space group of these phases is Pbnm, contrary to the previous literature reports of the space groups Pbcn and Pbcm for the rare-earth tungstates (RE = La, Ce, Pr, Nd) with this general formula. The structure contains rare-earth cations in seven-, eight- and ninefold coordination. W atoms are found in corner-sharing WO5 groups, and also in WO6 and WO7 polyhedra which share edges and corners to form W6O17 units. The new model obtained from our single-crystal work gives better agreement with powder XRD data on both Ce10W22O81 and Nd10W22O81, and gives more plausible coordination environments and bond-valence sums.
Five more phases of the structural family [M(H2O)2(15-crown-5)](NO3)2
Authors: Siegler Maxime A. , Hao Xiang , Parkin Sean , Brock Carolyn Pratt
Published: November 2008

The structures of five more phases of the structural family of compounds [M(H2O)2(15-crown-5)](NO3)2 have been determined. All of these phases are stable at room temperature or above, but transform to other phases if cooled slowly. All five phase transitions take place without significant damage to the single crystal. The M = Co phase, which has a three-dimensional hydrogen-bonding pattern, is a disordered version of the structure known at room temperature; Z′ changes from 2 to ½. The other four structures have a two-dimensional hydrogen-bonding pattern, are all modulated variants of the same basic cell (or subcell) and are at least mostly ordered. For M = Mg and Zn the structure found somewhat above room temperature is the Z′ = 8 variant found previously for M = Fe. For M = Cu and Ni the Z′ = 2 phase found is the same as seen previously for one of the room-temperature polymorphs with M = Mn. There are now two phases and one transition known for each M studied that has a two-dimensional hydrogen-bonding pattern. The changes in the modulation patterns during these transitions are Z′ 3 ↔ 8 (Mg, Fe, Zn), Z′ 3 ↔ 2 (Mn, Ni) and Z′ 5 ↔ 2 (Cu). In all two-dimensional hydrogen-bonded crystals the alternation pattern of conformational enantiomers along the modulation direction becomes more perfect above the phase transition. All stable [M(H2O)2(15-crown-5)](NO3)2 phases whose existence at accessible temperatures is indicated by differential scanning calorimetry (DSC) have now been characterized.
Chiral carboxylic acids and their effects on melting-point behaviour in co-crystals with isonicotinamide
Authors: Lemmerer Andreas , Báthori Nikoletta B. , Bourne Susan A.
Published: November 2008

The crystal structures of co-crystals of two systems of chiral carboxylic acids, optically active and racemic 2-phenylpropionic acid and 2-phenylbutyric acid, with isonicotinamide are reported to investigate the effects of the chirality of the chiral carboxylic acids on the melting point of the co-crystal complexes. It was found that the racemic co-crystal has a higher melting point than the optically active co-crystal, which correlates with the denser packing arrangement inherent in centrosymmetric space groups.
Polymorphism in cyclohexanol. Corrigendum
Authors: Ibberson Richard M. , Parsons Simon , Allan David R. , Bell Anthony M. T.
Published: November 2008

A replacement Fig. 6 to the paper by Ibberson et al. (2008), Acta Cryst. B64, 573–582 is given.
Oral budesonide for maintenance of remission of Crohn’s disease: a pooled safety analysis
Authors: LICHTENSTEIN G. R. , BENGTSSON B. , HAPTEN‐WHITE L. , RUTGEERTS P.
Published: November 2008

Background Budesonide exhibits similar efficacy to systemic glucocorticosteroids (GCSs) in Crohn’s disease (CD), but with fewer adverse events (AEs).

Aim To evaluate budesonide’s safety profile in CD patients, in particular, incidences of clinically important AEs known to be associated with systemic GCSs.

Methods Five 1‐year, double‐blind, placebo‐controlled trials evaluating budesonide for mild‐to‐moderate CD were pooled for analysis.

Results The highest incidence rates of AEs were gastrointestinal‐ and endocrine systems‐related in both groups (budesonide 6 mg/day,n = 208; placebo,n = 209). Incidence rates were similar, except for higher incidence of endocrine disorders in budesonide versus placebo patients (P = 0.0042) caused by a higher overall occurrence of cutaneous GCS symptoms (P = 0.0036) in the budesonide group; differences in individual symptoms were nonsignificant. Percentage of patients with normal adrenal function was significantly lower at 13 weeks (three of five studies), but not at 52 weeks (two studies) in the budesonide versus placebo groups. Occurrence of clinically important or serious AEs associated with systemic GCSs, including sepsis, cataracts, adrenal insufficiency was rare and similar between groups.

Conclusions Budesonide treatment for up to 1 year is well‐tolerated in CD patients, with an AE profile similar to placebo and only rare occurrences of clinically important AEs associated with systemic GCSs.
The residence time of stocked hatchery‐reared brown trout, Salmo trutta L., and rainbow trout, Oncorhynchus mykiss (Walbaum), in Lake Trawsfynydd, and their accumulation of radioactive caesium
Authors: TIPPLE J.R.J. , LEONARD D.R.P.
Published: November 2008

Abstract Small amounts of radioactivity in liquid effluent are discharged under authorization into Lake Trawsfynydd in north Wales. MAFF inspectors from the Directorate of Fisheries Research (DFR) advise the Welsh Office on the terms of authorization and on the power station operators' compliance with them. DFR also has the responsibility for environmental monitoring, including fish caught for consumption. Trout angling is particularly popular in Lake Trawsfynydd, and because of angling pressure, additional brown trout, Salmo trutta L., and rainbow trout, Oncorhynchus mykiss (Walbaum), need to be introduced. An important factor in determining the concentration of radionuclides in these fish is the length of time that they spend at liberty. During the fishing season, samples of these stocked trout were tagged and released to assess the average residence time. This was found to be 6 days for rainbow trout and 10 days for brown trout. Less than 7% of the recaptured stocked trout of either species had a residence time of more than 20 days. Radiocaesium concentrations in recaptured trout were very low. Trout which avoided recapture and overwintered in the lake were found to have radiocaesium concentrations similar to those of indigenous trout sampled at the same time.
Influence of river flow on rod catch of Atlantic salmon, Salmo salar L., from the lower River Derwent, north‐west England
Authors: APRAHAMIAN M. W. , BALL M.
Published: November 2008

Abstract Twenty‐seven years of daily salmon, Salmo salar L., rod catch and flow data from the River Derwent were analysed. Daily catch was standardized for each month between June and October and the mean value determined for each 2‐cumec flow band. In June and July the mean standardized catch remained relatively low and stable for flows up to approximately 9 cumecs. Thereafter it increased steadily with increasing flow, reaching a peak at 21 cumecs and 41 cumecs for each month respectively. A linear model accounted for the greatest proportion of the variability in August and September with mean standardized catch increasing steadily up to a maximum value of 43 and 39 cumecs respectively. However, in October, a quadratic model was more appropriate, with mean standardized catch decreasing as flow increased up to 9 cumecs and thereafter increasing steadily with flow, reaching a maximum value at 21 cumecs. The pattern of the relationship at higher flows was not clear because of the paucity of data. These findings are discussed in relation to the management of the water resource for the maintenance of the fishery.
Annual patterns of phytoplankton density and primary production in a large, shallow lake: the central role of light
Authors: TORREMORELL A. , LLAMES M. E. , PÉREZ G. L. , ESCARAY R. , BUSTINGORRY J. , ZAGARESE H.
Published: November 2008

1. We studied the seasonal dynamics of suspended particulate matter in a turbid, large shallow lake during an annual period (2005–06). We relate the patterns of seston concentration (total suspended solids), phytoplankton biomass and water transparency to the seasonal pattern of incident solar radiation (I0). We also report the seasonal trends of phytoplankton primary production (PP) and photosynthesis photoinhibition due to photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) (Iβ and UV50).

2. We first collected empirical evidence that indicated the conditions of light limitation persisted during the study period. We found that the depth‐averaged irradiance estimated for the time of the day of maximum irradiance (Imean–noon) was always lower than the measured onset of light saturation of photosynthesis (Ik).

3. We then contrasted the observations with theoretical expectations based on a light limitation scenario. The observed temporal patterns of seston concentration, both on a volume and area basis, were significantly explained by I0 (R2 = 0.39 and R2 = 0.37 respectively). The vertical diffuse attenuation coefficient (kdPAR) (R2 = 0.55) and the depth‐averaged irradiance (Imean) (R2 = 0.66), significantly increased with the I0; while the irradiance reaching the lake bottom (Iout) significantly decreased with the incident irradiance (R2 = 0.49). However, phytoplankton biovolume maxima were not coincident with the time of the year of maximum irradiance.

4. A significant positive relationship was observed between PP estimated on an area basis and I0 (R2 = 0.51, P < 0.001). In addition, the parameters describing the photosynthetic responses to high irradiances displayed marked seasonal trends. The photosynthesis photoinhibition due to PAR as well as to UV were significantly related to incident solar radiation (PAR: R2 = 0.73; UV: R2 = 0.74). These results suggest adaptation of the phytoplankton community in response to changes in incident solar radiation.
Uric acid deposits in symbiotic marine algae
Authors: CLODE PETA L. , SAUNDERS MARTIN , MAKER GARTH , LUDWIG MARTHA , ATKINS CRAIG A.
Published: November 2008

The symbiosis between cnidarians and dinoflagellate algae is not understood at the cell or molecular level, yet this relationship is responsible for the formation of thousands of square kilometres of coral reefs. We have investigated the nature of crystalline material prominent within marine algal symbionts ofAiptasiasp. anemones. This material, which has historically been considered to be calcium oxalate, is shown to be uric acid. We demonstrate that these abundant uric acid stores can be mobilized rapidly, thereby allowing the algal symbionts to flourish in an otherwise N‐poor environment. This is the first report of uric acid accumulation by symbiotic marine algae. These data provide new insight and considerations for understanding the physiological basis of algal symbioses, and represent a new and previously unconsidered aspect of N metabolism in cnidarian, and a variety of other, marine symbioses.
Bacterial rhamnolipids are novel MAMPs conferring resistance to Botrytis cinerea in grapevine
Authors: VARNIER ANNE‐LISE , SANCHEZ LISA , VATSA PARUL , BOUDESOCQUE LESLIE , GARCIA‐BRUGGER ANGELA , RABENOELINA FANJA , SOROKIN ALEXANDER , RENAULT JEAN‐HUGUES , KAUFFMANN SERGE , PUGIN ALAIN , CLEMENT CHRISTOPHE , BAILLIEUL FABIENNE , DOREY STEPHAN
Published: November 2008

Rhamnolipids produced by the bacteria Pseudomonas aeruginosa are known as very efficient biosurfactant molecules. They are used for a wide range of industrial applications, especially in food, cosmetics and pharmaceutical formulations as well as in bioremediation of pollutants. In this paper, the role of rhamnolipids as novel molecules triggering defence responses and protection against the fungus Botrytis cinerea in grapevine is presented. The effect of rhamnolipids was assessed in grapevine using cell suspension cultures and vitro‐plantlets. Ca2+ influx, mitogen‐activated protein kinase activation and reactive oxygen species production form part of early signalling events leading from perception of rhamnolipids to the induction of plant defences that include expression of a wide range of defence genes and a hypersensitive response (HR)‐like response. In addition, rhamnolipids potentiated defence responses induced by the chitosan elicitor and by the culture filtrate of B. cinerea. We also demonstrated that rhamnolipids have direct antifungal properties by inhibiting spore germination and mycelium growth of B. cinerea. Ultimately, rhamnolipids efficiently protected grapevine against the fungus. We propose that rhamnolipids are acting as microbe‐associated molecular patterns (MAMPs) in grapevine and that the combination of rhamnolipid effects could participate in grapevine protection against grey mould disease.
Focus on ecological weed management: what is hindering adoption?
Authors: BASTIAANS L , PAOLINI R , BAUMANN D T
Published: November 2008

Despite increased concerns regarding the heavy reliance of many cropping systems on chemical weed control, adoption of ecological weed management practices is only steadily progressing. For this reason, this paper reflects on both the possibilities and limitations of cultural weed control practices. Cultural weed control utilises a number of principles, predominantly: (i) a reduced recruitment of weed seedlings from the soil seedbank, (ii) an alteration of crop–weed competitive relations to the benefit of the crop and (iii) a gradual reduction of the size of the weed seedbank. Compared with chemical control, the general applicability, reliability and efficacy of most measures is only moderate, and consequently, cultural control strategies need to consist of a combination of measures, resulting in increased systems complexity. Combined with the trade‐offs connected to some of the measures, this hampers large‐scale implementation. It is argued that tailoring cultural weed management strategies to the needs and skills of individual farmers would be an important step forward. Research can aid in improving the utilisation of cultural weed control strategies by focussing on a broadening of the range of available measures and by providing clear quantitative insight in efficacy, variability in outcome and trade‐offs of these measures.
Ecological weed management by cover cropping: effects on weed growth in autumn and weed establishment in spring
Authors: KRUIDHOF H M , BASTIAANS L , KROPFF M J
Published: November 2008

Cover crops grown in the period between two main crops have potential as an important component of a system‐oriented ecological weed management strategy. In late summer and autumn, the cover crop can suppress growth and seed production of weeds, whereas the incorporation of cover crop residues in spring may reduce or retard weed emergence. Based on these two criteria, six cover crop species were evaluated for their weed suppressive potential in 2 years of experimentation in the Netherlands. Fodder radish, winter oilseed rape and winter rye had the strongest competitive ability in autumn; the competitive strength of Italian ryegrass was intermediate and white lupin and lucerne were poor competitors. Competitiveness was strongly correlated to early light interception. Surprisingly, doubling the recommended sowing density did not increase weed suppressive ability. Although a poor competitor in the fall, after incorporation in spring, lucerne had the strongest inhibitory effect on seedling establishment, followed by winter oilseed rape and white lupin. Winter rye and fodder radish did not affect seedling establishment, whereas Italian ryegrass was not evaluated because of re‐growth after incorporation. Competition in autumn and subsequent residue‐mediated suppression of weed establishment in spring varied among the cover crop species, with winter oilseed rape offering relatively strong effects during both periods.
Protocol Optimization for Long‐Term Liquid Storage of Goat Semen in a Chemically Defined Extender
Authors: Zhao B‐T , Han D , Xu C‐L , Luo M‐J , Chang Z‐L , Tan J‐H
Published: November 2008

Contents

A specific problem in the preservation of goat semen has been the detrimental effect of seminal plasma on the viability of spermatozoa in extenders containing egg yolk or milk. The use of chemically defined extenders will have obvious advantages in liquid storage of buck semen. Our previous study showed that the self‐made mZAP extender performed better than commercial extenders, and maintained a sperm motility of 34% for 9 days and a fertilizing potential for successful pregnancies for 7 days. The aim of this study was to extend the viability and fertilizing potential of liquid‐stored goat spermatozoa by optimizing procedures for semen processing and storage in the mZAP extender. Semen samples collected from five goat bucks of the Lubei White and Boer breeds were diluted with the extender, cooled and stored at 5°C. Stored semen was evaluated for sperm viability parameters, every 48 h of storage. Data from three ejaculates of different bucks were analysed for each treatment. The percentage data were arcsine‐transformed before being analysed with anova and Duncan’s multiple comparison test. While cooling at the rate of 0.1–0.25°C/min did not affect sperm viability parameters, doing so at the rate of 0.6°C/min from 30 to 15°C reduced goat sperm motility and membrane integrity. Sperm motility and membrane integrity were significantly higher in semen coated with the extender containing 20% egg yolk than in non‐coated semen. Sperm motility, membrane integrity and acrosomal intactness were significantly higher when coated semen was 21‐fold diluted than when it was 11‐ or 51‐fold diluted and when extender was renewed at 48‐h intervals than when it was not renewed during storage. When goat semen coated with the egg yolk‐containing extender was 21‐fold diluted, cooled at the rate of 0.07–0.25°C/min, stored at 5°C and the extender renewed every 48 h, a sperm motility of 48% was maintained for 13 days, and an in vitro‐fertilizing potential similar to that of fresh semen was maintained for 11 days.
The risk of venous thromboembolism associated with the use of tranexamic acid and other drugs used to treat menorrhagia: a case–control study using the General Practice Research Database
Authors: Sundström A , Seaman H , Kieler H , Alfredsson L
Published: November 2008

Objective  To assess whether use of tranexamic acid is associated with an increased risk of venous thromboembolism (VTE).

Design  Nested case–control study.

Setting  Database study using the General Practice Research Database for the years 1992–1998.

Population  Women aged 15–49 years with a diagnosis of menorrhagia.

Methods  Multivariate conditional logistic regression was used to estimate the risk for VTE associated with different drug treatments for menorrhagia, adjusting for confounders.

Main outcome measures  Adjusted odds ratios with 95% CI.

Results  A total of 134 cases of VTE and 552 matched controls were identified. Recent use of tranexamic acid was scarce, yielding an adjusted odds ratio for VTE of 3.20 (95% CI 0.65–15.78). The use of mefenamic acid (ORadj 5.54 [95% CI 2.13–14.40]) or norethisterone (ORadj 2.41 [95% CI 1.00–5.78]) was associated with an increased risk of VTE, as was a recent—in relation to menorrhagia—diagnosis of anaemia or a haemoglobin value <11.5 g/dl (ORadj 2.23 [95% CI 1.02–4.86]).

Conclusions  We found that tranexamic acid was associated with an increased risk of VTE, although the risk estimate did not reach statistical significance. Increased risks of VTE associated with other treatments for menorrhagia were observed. The increased risk of VTE observed with a diagnosis of anaemia—a proxy for more severe menorrhagia—suggests that menorrhagia could be a prothrombotic condition. The observed association between VTE, tranexamic acid and other treatments for menorrhagia may thus partly be explained by confounding by indication. The possibility that menorrhagia is itself a risk factor for VTE merits further investigation.
A randomised controlled trial of routine versus restrictive use of episiotomy at operative vaginal delivery: a multicentre pilot study
Authors: Murphy DJ , Macleod M , Bahl R , Goyder K , Howarth L , Strachan B
Published: November 2008

Objective  To compare the maternal and neonatal outcomes of operative vaginal delivery in relation to the use of episiotomy.

Design  Pilot randomised controlled trial (RCT).

Setting  Two urban maternity units in Scotland and England.

Sample  Nulliparous women anticipating a singleton cephalic vaginal delivery were recruited in the antenatal period.

Methods  If an operative vaginal delivery was required in the second stage of labour, women were randomised to either routine (in all cases) or restrictive (only if tearing apparent) use of episiotomy.

Main outcome measures  The primary outcome was anal sphincter tearing (third or fourth degree). Secondary outcomes included postpartum haemorrhage (PPH), neonatal trauma and pelvic floor symptoms up until 10 days postpartum.

Results  In a group of 317 women requiring operative vaginal delivery, 200 were randomised: 99 to routine use of episiotomy and 101 to restrictive use. There were small differences in the rates of anal sphincter tears (8.1% routine versus 10.9% restrictive, OR 0.72, 95% CI 0.28–1.87) and primary PPH (36.4% routine versus 26.7% restrictive, OR 1.57, 95% CI 0.86–2.86). Neonatal trauma was similar between the two groups (45.5% routine versus 43.6% restrictive, OR 1.08, 95% CI 0.62–1.89), as was prolonged catheterisation, urinary incontinence, faecal incontinence, perineal infection and prolonged hospital admission.

Conclusions  This pilot study does not provide conclusive evidence that a policy of routine episiotomy is better or worse than a restrictive policy. A definitive RCT is feasible but will require a large sample size to inform clinical practice.
EXTENSION OPPORTUNITIES IN MARKETING1
Authors: HOW R. BRIAN
Published: November 2008

In summary I would like to make the following points:

1. There are numerous opportunities for educational programs in agricultural marketing that would be of value to farmers, to the management of marketing firms, and to consumers.

2. In Colleges and Departments of Agriculture our first responsibility is still to farm people, even though they are actually performing fewer marketing services today.

3. Marketing information of most general use to farmers is that which helps them understand the economic situation and outlook, and important economic principles related to marketing.

4. Developing educational programs with marketing firms requires a change in direction from primary concern with farm problems to concern with the problems of the private marketing firm. While this may be difficult to accept, there is really no direct conflict of interest between programs for farmers and those for marketing firm personnel and the methods and kinds of information available can often be used in both areas.

5. Programs with marketing firms are as varied as the needs of the firms themselves. The extension specialist well versed in a particular phase of business management, or equipped with a particular set of analytical tools, or familiar with recent research findings, can make considerable improvement in the efficiency of operation of most marketing firms.

6. A major policy question at present is how far we should go in working with marketing firms. There is considerable agreement that some work is desirable from the point of view of providing greater knowledge of marketing, and that it can be done with little additional help and few special studies.

7. Arguments presented in favor of considerable expansion in marketing work are that legislators are willing to provide public support, the need is great in view of rising marketing costs and obvious inefficiencies, and benefits to agriculture are as great as for some of the farm production work.

8. Those who caution against moving too rapidly in this area are reluctant to divert resources away from agricultural programs, and argue that once work with marketing firms is initiated there is no logical place to draw the line on extension programs.

9. The case for marketing information for consumer programs is largely based on the complexity of modern food marketing. The growth of new products and more processing would indicate that educational programs in buying foods for homes or institutions will expand in the future.

10. Extension programs in marketing can be successful if the educational feature is stressed, and the programs are based on sound research, conducted by competent personnel using appropriate methods, and given the freedom and administrative support necessary for the job.
WESTER WHEAT MARKETING IN ONTARIO
Authors: CRADDOCK W. J.
Published: November 2008

The purpose of this paper is to assess the success of the Ontario Wheat Producers' Marketing Board in fulfilling the need which prompted its formation. Its prime objective was to increase, by various means, the proceeds received by producers from the sale of winter wheat. This paper will focus on the Board's efforts to raise these returns by means of its minimum price policy. Empirical problems greatly hindered the evaluation. The conclusions reached have largely been derived from logical deductions rather than from refined statistical techniques.
YIELD PREDICTIONS FOR 1965 WHEAT, OATS, AND BARLEY IN MANITOBA1
Authors: YEH MARTIN H.
Published: November 2008

This is an aggregate study based on the time series data, 1921 to 1964, covering the entire Province of Manitoba on a district‐by‐district basis. The study has attempted to include three parts. First it has examined grain yield fluctuations and has selected the most significant factors influencing yields. These include resource inputs, technology, weather and chance. Second, the study has developed a method by which the influence of each factor on grain yields may be measured. Third, it has shown that grain yields can be forecast within an acceptable margin of error, based on the past pattern of weather cycles, the current trend of technical advance and a monthly assessment of rainfall and temperature during seeding, growing and harvesting periods in any given year.

The findings from this study show that the predicted yields for each of the grain crops were reasonably close to the actual yields, demonstrating an adequate model used and the efficiency of the analytical technique employed. Additional work on this topic is necessary, firstly to explore other possible methods of analysis and, secondly, to extend the analysis to cover the other two prairie provinces on a district‐by‐district basis, in order to be able to provide more information regarding the crop predictions which may be useful to farmers, distributors, businessmen, and governments involved in decision making.
A Regional Analysis Of The Supply And Demand Of Farm Labor In Canada
Authors: YEH M. H. , LI LEW‐KING
Published: November 2008

This is an aggregative study covering the years 1946 to 1962, with the primary objective ofexamining the most significant factors which affect a market structure for farm labor. A recursive system is used to derive an equilibrium level of both hired and family farm labor during the period studied as well as an equilibrium level of future farm labor requirement by 1970.

The findings show that the demand for farm labor was apparently not, or weakly, responsive to the farm wage rate in all regions and it was weakly responsive to the parity ratio, farm machinery and productivity. On the supply side, farm labor also was not, or weakly, responsive to the variables included in all regions with the exception of the farm wage rate or parity ratio in B.C. and the adjusted non‐farm wage rate and farm machinery in the Atlantic region. The results also show that, in Canada as a whole, the projected family labor employment will be 294,000 manequivalents by 1910 or 42 percent decline as compared to the 1962 level, while the projected hired labor employment will be 114,000 manequivalents in 1970 or 14 percent increase in the eight years after 1962. This would likely be the tendency because of the continuous economic development on the one hand and the consolidation of farms on the other.
MEASURING THE RELATIVE INCOME OF FARM LABOUR, 1941–611
Authors: KULSHRESHTHA S. N.
Published: November 2008

This is an analysis of farm labour income at an aggregate level for the period 1941 to 1961. The income of farm labour was estimated for paid workers, operators or self‐employed workers, and total paid and unpaid workers, These incomes were compared with five sub‐sectors of the nonfarm economy and for five geographical regions. In estimating income, adjustments were made for the age and sex composition of labour force, bours of work in various industries, movement of prices of inputs and output, and period of employment of farm workers.

The results show significant differences in incomes of various categories of workers, and incomes of farm workers compared to various sub‐sectors of the nonfarm economy. Similarly, various regions were found to. be highly heterogeneous with respect to relative labour income levels. When the farm and nonfarm sectors were adjusted for differences in characteristics, the labour income ratio of Canadian agriculture on a normalized man equivalent basis ranged between 41 and 63 percent.
SITE SELECTION FOR REGIONAL PUBLIC INVESTMENTS*
Authors: BENDER LLOYD D.
Published: November 2008

Investments in community and human resources to facilitate adaptive regional economic and social changes can occur in an infinite number of places and forms. It is extremely difficult to consider social and economic payoffs in such large arrays simultaneously. Policymakers need models which identify places with the best potential. After initial screening has reduced the number of places to manageable proportions, other methods can be applied to places, and the investments to be made. One set of definitions and classification schemes out of the many possible for initial screening is developed in this study, using previously developed tools, and applied to the Ozarks Region of the United States.
US TENDANCES DE LA PRODUCTIVITE TOTALE DANS L'AGRICULTURE: CANADA, ONTARIO, QUEBEC, 1926–64
Authors: WAMPACH J. P.
Published: November 2008

This paper measures and analyses the changes in total productivity of Canadian, Ontario and Quebec agriculture for the period 1926 to 1964. The rate of growth in productivity from 1945 to 1964 has been about the same for Canadian and Ontario agriculture while that of Quebec has been higher than either by one per cent a year. Total productivity gains correspond to decreases in the average costs of production at the farm level. Quebec's farmers have therefore improved their relative position as competitors. These productivity gains have important and far reaching implications not only for fanners and the agricultural industry but also for the provinces and the entire Canadian economy.
A Capital Budgeting, Mixed Integer, Temporal Programming Model
Authors: COLYER DALE
Published: November 2008

A temporal model utilizing mixed integer programming was constructed to evaluate investment alternatives in combination with the present value method of capital budgeting. As such it is a first step beyond conventional linear and integer programming in developing relevant capital decision‐making models. The procedure permits the consideration of investment in discontinuous (lumpy) inputs which also are interdependent —thus overcomes some of the principle weaknesses of other capital budgeting procedures. The model was tested with a relatively simple five‐year model including land and machinery investment alternatives for a cash grain farm and proved capable of handling both the discontinuities and interrelationships. The possibilities of extending the model to include a greater range of alternatives and more complicated interrelationships such as reinvestment of intermediate cash throwoffs also was explored.
Regional Planning For Depressed Rural Areas —The Canadian Experience1
Authors: POETSCHKE L. E.
Published: November 2008

Attempts are being made to improve the level of living of people in depressed rural areas in Canada. The most significant institutional efforts are those by the Agricultural and Rural Development Administration's comprehensive planning programs.

A description is given of the problem confronted both from an economic development and practical planning viewpoint. The evolving federal program including general research procedures are discussed along with the specific area programs that are being developed and implemented.
COOPERATIVE INSTITUTIONS: THE WIDE AND THE NARROW1
Authors: LAIDLAW A. F.
Published: November 2008

An important problem confronting agriculture is institutional adaptation to the needs and changes of yesterday, today and tomorrow. This paper looks at some challenges facing a familiar institution to agriculture — the cooperative. While other problem areas often considered distant to agriculture are focused on, it is apparent that there is much interdependence between rural and urban problems and institutional change in helping bring about solutions. With present urban problems and their likelihood of persisting for some time, the encouragement of farm people to become city dwellers may need to be more seriously appraised. Similarly there is a need for better understanding of the role of institutions, their jobs, and the socio‐economic impact of alternate means in achieving them before real progress can be broadly achieved.