bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF LIGHT AND TEMPERATURE ON GROWTH, NITRATE UPTAKE, AND TOXIN PRODUCTION OF TWO TROPICAL DINOFLAGELLATES:ALEXANDRIUM TAMIYAVANICHIIANDALEXANDRIUM MINUTUM(DINOPHYCEAE)1
Authors: Lim Po‐Teen , Leaw Chui‐Pin , Usup Gires , Kobiyama Atsushi , Koike Kazuhiko , Ogata Takehiko
Published: July 2006

The two tropical estuarine dinoflagellates,Alexandrium tamiyavanichiiBalech andA.minutumHalim, were used to determine the ecophysiological adaptations in relation to their temperate counterparts. These species are the two main causative organisms responsible for the incidence of paralytic shellfish poisoning (PSP) in Southeast Asia. The effects of light (10, 40, 60, and 100 μmol photons·m−2·s−1) and temperature (15, 20, and 25°C) on the growth, nitrate assimilation, and PST production of these species were investigated in clonal batch cultures over the growth cycle. The growth rates ofA.tamiyavanichiiandA.minutumincreased with increasing temperature and irradiance. The growth ofA.tamiyavanichiiwas depressed at lower temperature (20°C) and irradiance (40 μmol photons·m−2·s−1). Both species showed no net growth at 10 μmol photons·m−2·s−1and a temperature of 15°C, although cells remained alive. Cellular toxin quotas (Qt) ofA.tamiyavanichiiandA.minutumvaried in the range of 60–180 and 10–42 fmol PST·cell−1, respectively. Toxin production rate,Rtox, increased with elevated light at both 20 and 25°C, with a pronounced effect observed at exponential phase in both species (A.tamiyavanichii,r2=0.95;A.minutum,r2=0.96). Toxin production rate also increased significantly with elevated temperature (P<0.05) for both species examined. We suggest that the ecotypic variations in growth adaptations and toxin production of these Malaysian strains may reveal a unique physiological adaptation of tropicalAlexandriumspecies.
Ferroelectric and Piezoelectric Properties of Na1−xBaxNb1−xTixO3 Ceramics
Authors: Zeng J. T. , Kwok K. W. , Chan H. L. W.
Published: July 2006

Piezoelectric ceramics Na1−xBaxNb1−xTixO3 with low BaTiO3 concentrations x have been prepared by the solid‐state reaction method, and their ferroelectric and piezoelectric properties have been studied. The ceramics are classic ferroelectrics when x≤0.10, and the ferroelectric–paraelectric phase transition becomes diffusive when x≥0.15. A low doping level of BaTiO3 changes the NaNbO3 ceramics from antiferroelectric to ferroelectric. With the increase in BaTiO3 doping level, the Curie temperature of ceramics decreases linearly and the remnant polarization and coercive field also decrease, while their dielectric constant increases. Na0.9Ba0.1Nb0.9Ti0.1O3 ceramics show the largest piezoelectric constant d33 (147 pC/N) and good sinterability, suggesting that it is a good candidate for lead‐free piezoelectric ceramics.
Proper Assessment of the JFK Assassination Bullet Lead Evidence from Metallurgical and Statistical Perspectives
Authors: Randich Erik , Grant Patrick M.
Published: July 2006

ABSTRACT: The bullet evidence in the JFK assassination investigation was reexamined from metallurgical and statistical standpoints. The questioned specimens are comprised of soft lead, possibly from full‐metal‐jacketed Mannlicher‐Carcano (MC), 6.5‐mm ammunition. During lead refining, contaminant elements are removed to specified levels for a desired alloy or composition. Microsegregation of trace and minor elements during lead casting and processing can account for the experimental variabilities measured in various evidentiary and comparison samples by laboratory analysts. Thus, elevated concentrations of antimony and copper at crystallographic grain boundaries, the widely varying sizes of grains in MC bullet lead, and the 5–60 mg bullet samples analyzed for assassination intelligence effectively resulted in operational sampling error for the analyses. This deficiency was not considered in the original data interpretation and resulted in an invalid conclusion in favor of the single‐bullet theory of the assassination. Alternate statistical calculations, based on the historic analytical data, incorporating weighted averaging and propagation of experimental uncertainties also considerably weaken support for the single‐bullet theory. In effect, this assessment of the material composition of the lead specimens from the assassination concludes that the extant evidence is consistent with any number between two and five rounds fired in Dealey Plaza during the shooting.
Classification of Black Powder Toners on the Basis of Integrated Analytical Information Provided by Fourier Transform Infrared Spectrometry and X‐Ray Fluorescence Spectrometry
Authors: Trzcińska Beata M.
Published: July 2006

ABSTRACT:Differentiating between black powder toners used in laser printers and copiers can be challenging for forensic examiners. One hundred and sixty‐two samples from 82 different types of cartridges produced by 21 manufacturers that are currently available on the Polish market were studied using Fourier transform infrared spectrometry (FT‐IR) and energy‐dispersive X‐ray fluorescence spectrometry (XRF). The spectra obtained by these two methods were classified into 14 groups and 28 groups using FT‐IR and XRF, respectively. These classifications served as a basis for the development of an analytical scheme for differentiating black powder toners. This scheme can be used with any two methods that supply different information about an examined sample. The research will show that if two samples are similar in polymer composition (e.g., FT‐IR spectra), additional quantitative elemental composition from XRF analyses may provide more discrimination. It was possible to differentiate 82.5% pairs of examined samples using only FT‐IR, 90.8% pairs of examined samples using only XRF, and 95.8% pairs of examined samples using these two methods.

Obtained spectra and all the available information could be used to create/build a database. The results obtained confirm the multiplicity and compatibility of toners. Additionally, it was stated that not all the samples were original (OEM).
Fast Gas Chromatography of Explosive Compounds Using a Pulsed‐Discharge Electron Capture Detector*
Authors: Collin Olivier L. , Niegel Claudia , DeRhodes Kate E. , McCord Bruce R. , Jackson Glen P.
Published: July 2006

ABSTRACT: The detection of a mixture of nine explosive compounds, including nitrate esters, nitroaromatics, and a nitramine in less than 140 sec is described. The new method employs a commercially available pulsed‐discharge electron capture detector (PDECD) coupled with a microbore capillary gas chromatography (GC) column in a standard GC oven to achieve on‐column detection limits between 5 and 72 fg for the nine explosives studied. The PDECD has the benefit that it uses a pulsed plasma to generate the standing electron current instead of a radioactive source. The fast separation time limits on‐column degradation of the thermally labile compounds and decreases the peak widths, which results in larger peak intensities and a concomitant improvement in detection limits. The combination of short analysis time and low detection limits make this method a potential candidate for screening large numbers of samples that have been prepared using techniques such as liquid–liquid extraction or solid‐phase microextraction.
Evaluation and Comparison of the Electrostatic Dust Print Lifter and the Electrostatic Detection Apparatus2 on the Development of Footwear Impressions on Paper*
Authors: Craig Christine L. , Hornsby Breanne M. , Riles Matthew
Published: July 2006

ABSTRACT: The Electrostatic Dust Print Lifter (EDPL) and the Electrostatic Detection Apparatus2 (ESDA2) were compared to determine if both processes could be used to develop footwear impressions of the same or similar quality and in what order they should be used to develop the highest quality footwear impression. The sensitivity of each technique was also evaluated. The quality of the footwear impressions developed was determined by comparing 25 individual characteristics present on the known shoe to the footwear impressions developed using each technique. The footwear impressions were made by stepping on paper placed over several different surfaces, which included: linoleum, industrial Berber carpet, nylon carpet placed over a ⅜‐in. pad, ceramic tile, cardboard, 1‐in. foam, 4‐in. foam, cement, asphalt, grass, and mulch. Each of the papers placed on these surfaces was developed using the EDPL before the ESDA2 and vice versa. The sensitivity test for the ESDA2 was conducted by processing 10 sheets of stacked paper that were stepped on with the known shoe, beginning with the top sheet. The sensitivity test for the EDPL was conducted by processing 10 sheets of paper stepped on with the known shoe in succession. This study determined the footwear impressions developed using the EDPL were of better comparative value than impressions developed with the ESDA2. On average, 72.4% of the individual characteristics from the known impression were identified on images developed when the EDPL was used first compared with an average of 38.9% when the ESDA2 was used first. Therefore, if only one technique is used, the EDPL should be chosen. The sensitivity test determined the ESDA2 develops high‐quality footwear impressions on only the top sheet of paper. No footwear impressions were developed on any sheets under the top sheet of paper. The sensitivity test also determined the EDPL results increase in quality as the amount of dust residue decreases on the surface.
Evaluating the Accuracy and Precision of Cranial Morphological Traits for Sex Determination
Authors: Williams Brenda A. , Rogers Tracy L.
Published: July 2006

ABSTRACT: Sex determination is a key analysis that forensic anthropologists perform in order to construct a biological profile of human remains. The techniques used in forensic investigations must meet the Mohan or Daubert criteria, for admissibility in a court of law. In this study, the precision and accuracy of 21 morphological characteristics of the skull were tested on a modern sample of 50 adult crania of European White ancestry. The following craniofacial features are identified as high‐quality traits, defined by intraobserver error ≤10% and accuracy ≥80%: mastoid size, supraorbital ridge size, general size and architecture, rugosity of the zygomatic extension, size and shape of the nasal aperture, and gonial angle. Ninety‐six percent accuracy and 92% precision were achieved using 20 traits in combination. Fisher's exact probability tests revealed no significant differences (p=0.05) in the levels of precision or accuracy between age categories. Sex‐related bias in accuracy was found for the following cranial features: ramus symphysis (p=0.009), zygomatic extension (p=0.0016), and occipital markings (p=0.0013). These traits demonstrated a greater tendency to be scored male than female.
A Simple MicroThermal Desorption Device
Authors: Andrasko Jan
Published: July 2006

ABSTRACT: A new method for thermal desorption of small samples is presented. The method uses a solid phase microextraction (SPME) holder with the fiber removed. The sample—for example, an ink sample on paper—is simply placed inside the needle of the holder, where normally an SPME fiber is positioned. The thermal desorption is then performed on any kind of gas chromatograph in a manner similar to that for SPME analysis. The needle of the SPME holder penetrates the injector septum; the temperature of the thermal desorption is simply the temperature of the injector. No solvents or liquid nitrogen cooling are used. The paper sample is kept inside the holder needle during the analysis. After the analysis is completed, the sample is removed from the needle by pushing forward the steel wire inside the needle in the way normally used to perform sampling with the SPME fiber. The desorbed compounds were analyzed by gas chromatography with a flame ionization detector or by gas chromatography‐mass spectrometry. The optimum temperature for desorption of ink samples on paper was 200°C. The influence of the paper matrix is negligible at that temperature. Laboratories lacking the commercial device for thermal desorption can use this cheap device for the analysis of, for example, writing ink, printing ink, and inkjet ink samples on paper. Other types of samples can be investigated but the size of samples suitable for analysis is limited.
Laser Microdissection Separation of Pure Spermatozoa from Epithelial Cells for Short Tandem Repeat Analysis*
Authors: Sanders Christine T. , Sanchez Nick , Ballantyne Jack , Peterson Daniel A.
Published: July 2006

ABSTRACT: Short tandem repeat (STR) analysis is a valuable tool in identifying the source of biological stains, particularly from the investigation of sexual assault crimes. Difficulties in analysis arise primarily in the interpretation of mixed genotypes when cell separation of the sexual assailant's sperm from the victim's cells is incomplete. The forensic community continues to seek improvements in cell separation methods from mixtures for DNA typing. The feasibility of applying laser microdissection (LMD) technology to precisely separate sexual assault cell mixtures by visual inspection coupled with laser dissection was assessed through three experiments. First, various histological stains were evaluated for use with LMD and DNA analysis. Second, different DNA isolation methods were evaluated on LMD‐collected cells. Finally, STR analysis was performed on LMD‐separated sperm cells from mixtures of semen and female buccal epithelial cells. The results indicated (a) hematoxylin/eosin staining performed best in its ability to differentiate sperm and epithelial cells while exhibiting the least negative effect on further downstream analysis; (b) both QIAamp® and Lyse‐N‐Go™ methods were useful for recovery of DNA from LMD‐collected sperm cells; and (c) LMD separation provided clear STR profiles of the male donor with the absence of any additional alleles from the female donor. This report describes an efficient, low‐manipulation LMD method for the efficient separation of spermatozoa from two‐donor sperm/epithelial cell mixtures.
Allele Frequencies and Haplotypes of the 12 Y‐STR Loci Using the PowerPlex® Y System in Japanese Population*
Authors: Morikawa Toshio , Nakaki Shin‐ichi , Moriyoshi Hiroyuki , Nakayama Hideki , Hino Daiki , Miyoshi Miki , Itohara Koji
Published: July 2006

POPULATION: Unrelated Japanese males (n=153).
Allele Frequencies for Two STR Loci D4S3251 and D8S2321 in Chinese Population
Authors: Wu Wei , Jiang Shi , Yun Li Bing , Liu Li , Bai Peng , Yan Jing , Zhang Ji , Li Ying Bi , Wu Jin , Hou Yi Ping
Published: July 2006

POPULATION: Chinese Han.
Close‐range, in‐flight integration of olfactory and visual information by a host‐seeking bark beetle
Authors: Campbell Stuart A. , Borden John H.
Published: July 2006

A long‐standing controversy questions whether foraging bark beetles assess the suitability of individual host trees using cues at close range while flying or engage in random landing followed by contact assessment. In most cases, visual discrimination mechanisms are ignored. We show that pheromone‐responding mountain pine beetles (MPB), Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae), can visually discriminate between ‘host’ (black) and ‘non‐host’ (white) traps arranged in small clusters, in the absence of additional host olfactory information, and that males (but not females) demonstrate a greater preference for combined host visual and olfactory cues. However, white, non‐host traps baited with a host volatile were as attractive as unbaited, black host traps. Our results support the hypotheses that when deciding to land, the MPBs integrate visual and olfactory information and can process cues in both sensory modes at relatively close range (≤2 m). Thus, host selection mechanisms in this species are unlikely to be random with respect to either sensory mode.
Temporal variation in arthropod sampling effectiveness: the case for using the beat sheet method in cotton
Authors: Wade Mark R. , Scholz Brad C.G. , Lloyd Richard J. , Cleary Amanda J. , Franzmann Bernie A. , Zalucki Myron P.
Published: July 2006

Predatory insects and spiders are key elements of integrated pest management (IPM) programmes in agricultural crops such as cotton. Management decisions in IPM programmes should to be based on a reliable and efficient method for counting both predators and pests. Knowledge of the temporal constraints that influence sampling is required because arthropod abundance estimates are likely to vary over a growing season and within a day. Few studies have adequately quantified this effect using the beat sheet, a potentially important sampling method. We compared the commonly used methods of suction and visual sampling to the beat sheet, with reference to an absolute cage clamp method for determining the abundance of various arthropod taxa over 5 weeks. There were significantly more entomophagous arthropods recorded using the beat sheet and cage clamp methods than by using suction or visual sampling, and these differences were more pronounced as the plants grew. In a second trial, relative estimates of entomophagous and phytophagous arthropod abundance were made using beat sheet samples collected over a day. Beat sheet estimates of the abundance of only eight of the 43 taxa examined were found to vary significantly over a day. Beat sheet sampling is recommended in further studies of arthropod abundance in cotton, but researchers and pest management advisors should bear in mind the time of season and time of day effects.
Can gene delivery close the door to HIV‐1 entry after escape?
Authors: Swan C.H. , Torbett B.E.
Published: July 2006

Background  Research efforts to prevent viral entry by developing small molecule inhibitors against HIV‐1 chemokine coreceptors have yielded promising clinical results. However, resistance to some chemokine receptor inhibitors has been recently documented, and therefore, alternative methods of HIV‐1 coreceptor disruption are needed.

Conclusion  We will describe current HIV‐1 vector‐delivered genetic disruption mechanisms that target HIV‐1 chemokine coreceptors, such as RNA interference, ribozymes, zinc fingers, intrakines, and intrabodies, and frame the use of these gene delivery chemokine receptor disruption mechanisms in the context of current small molecule blocker/antagonists of CCR5 and CXCR4. In addition, we will discuss the importance of evaluating HIV‐1 vector‐delivered viral entry prevention mechanisms in the rhesus macaque SIV non‐human primate model in regard to pathogenesis and therapeutic efficacy.
Measuring and modelling the effects of inoculation date and aphid flights on the secondary spread of Beet mosaic virus in sugar beet
Authors: DUSI A N , PETERS D , VAN DER WERF W
Published: July 2006

The effect of the inoculation date on the spread of Beet mosaic virus (BtMV) in sugar beet field plots was studied. Two plants in the centre of each plot were inoculated with BtMV using Myzus persicae. The spread of the infection around these sources was monitored by inspecting the plants on two diagonal transects through the centre of the plot. Early inoculations resulted in a greater spread than late inoculations, but any inoculation before the onset of the aphid migration resulted in a similar‐sized spread. The spread was concentrated in patches around the inoculated plants, and its rate was explained by vector pressure, as shown by regression analysis and a mechanistic simulation model. This vector pressure was quantified using data obtained by catching aphids in a green water trap in the crop, catching aphids in a 12 m high suction trap at a distant location, and infection of bait plants from adjacent virus source plants. The daily total aphid catches obtained by a suction trap provided the best statistical explanation for the spread of this virus. The parameter r, describing the relationship between vector pressure and the rate of disease progress, was remarkably robust. This parameter varied less than 10% between treatments (infection date) within a single experiment, and less than a factor two between four experiments performed at different sites in two years. The robustness of this parameter suggests that the spread of a potyvirus may be predicted on the basis of the initial infection date and vector abundance.
Tolerance to reniform nematode (Rotylenchulus reniformis) race A in pigeonpea (Cajanus cajan) genotypes
Authors: SHARMA S B , JAIN K C , LINGARAJU S
Published: July 2006

The reniform nematode (Rotylenchulus reniformis) is an important pathogen of pigeonpea (Cajanus cajan). Forty‐six medium maturity (mature in 151–200 days at Patancheru, India) pigeonpea genotypes were evaluated for resistance and tolerance to the reniform nematode in greenhouse and field tests, over the period 1990–97. Each genotype was screened for number of nematode egg masses on a 1 (no egg mass = highly resistant) to 9 (> 50 egg masses = highly susceptible) scale. Plant biomass production in carbofurantreated plots was compared with that in non‐treated plots in a field naturally infested with R. reniformis. Pigeonpea genotypes C 11, ICPL 87119 and ICPL 270 were used as nematode susceptible checks. Genotypes with good plant growth, both in nematode‐free and nematode‐infested plots, were identified as tolerant and evaluated for plant growth and yield for at least three years. All the tested genotypes were susceptible (7 and 9 egg mass score). Single‐plant‐selections, based on plant vigour and yield, were made from genotypes showing tolerance to nematode infection. The level of tolerance was enhanced by plant‐to‐progeny row selection for plant vigour and seed yield in a nematode‐sick field for at least three years. The most promising nematode tolerant genotypes produced significantly greater yield and biomass than the locally grown pigeonpea cultivars in fields naturally infested with R. reniformis at two locations. Pigeonpea landraces are considered to be the most likely sources of tolerance to the nematode. These reniform nematode tolerant lines represent new germplasm and they are available in the genebank of pigeonpea at ICRISAT bearing accession numbers ICP 16329, ICP 16330, ICP 16331, ICP 16332, and ICP 16333.
Ovule differences between single‐kernelled and double‐kernelled fruits in almond (Prunus dulcis)
Authors: EGEA J , BURGOS L
Published: July 2006

In order to detect differences between almond cultivars that commonly produce one or two seeds, we compared ovule sizes and developmental stages at anthesis and three days after anthesis. The results showed that the presence of only small differences in size between primary and secondary ovules during flowering seemed to be a necessary but not sufficient condition for the production of double‐kernelled fruits. In contrast, differences in the developmental stage of both ovules did not prevent the production of double kernels. Large differences in ovule size at anthesis or in the following days resulted in fruits with single seeds. The behaviour of the secondary ovules in cultivars producing fruit with single seeds was very different, even in closely related cultivars. The degeneration of the secondary ovule seems to be genetically programmed and follows a genotype‐dependent pattern.
Occurrence of Peronospora sparsa (P. rubi) on cultivated and wild Rubus species in Finland and Sweden
Authors: KOPONEN H , HELLQVIST S , LINDQVIST‐KREUZE H , BÅNG U , VALKONEN J P T
Published: July 2006

An outbreak of a dryberry disease caused by Peronospora sparsa (syn. P. rubi) occurred in plantations of arctic bramble (Rubus arcticus subsp. arcticus) in Finland in the middle of 1990s. The disease persists and is most severe in cool and rainy summers. The disease has not been encountered in northern Sweden where cultivars (R. arcticus nothosubsp. stellarcticus) different from those in Finland are used. The occurrence of P. sparsa in wild Rubus spp. is virtually unknown in both areas and it is not known whether they constitute a potential infection source. Therefore, the aim of this study was to investigate the occurrence of P. sparsa on wild Rubus spp. growing in the vicinity of cultivations of arctic bramble. Symptomatic plants were sampled in 1997–1999. P. sparsa was detected using a light microscope, preceded by incubation of the sample in vitro if necessary, and by a polymerase chain reaction (PCR) based method. Plants of cultivated R. arcticus subsp. arcticus were commonly infected by P. sparsa in Finland. P. sparsa was also found on the cultivated R. arcticus nothosubsp. stellarcticus in Finland and Sweden. However, the infected plants of the cultivars of nothosubsp. stellarcticus seemed to be much less damaged than the cultivars of subsp. arcticus. Plants infected with P. sparsa were found in the populations of wild R. arcticus subsp. arcticus in both countries, and in cloudberry (R. chamaemorus) in natural habitats in Finland. In addition, P. sparsa was detected on specimens of R. arcticus subsp. arcticus (collected in 1966–1985) and R. chamaemorus (collected in 1899–1981) in Finnish herbaria. The samples of R. idaeus and R. saxatilis collected from the field in this study or investigated in the herbaria were not infected with P. sparsa. These data show that P. sparsa has not recently invaded Finland but has become an economically significant pathogen during the rapid expansion of cultivation of the apparently sensitive clones of arctic bramble.
Tomato spotted wilt virus (TSWV) in Greece: its incidence following the expansion of Frankliniella occidentalis, and characterisation of isolates collected from various hosts
Authors: CHATZIVASSILIOU E K , WEEKES R , MORRIS J , WOOD K R , BARKER I , KATIS N I
Published: July 2006

Leaf samples were collected from plants with tospovirus‐like symptoms from various hosts in different regions of Greece where Thrips tabaci, Frankliniella occidentalis or both vectors occur. The viruses infecting these plants were identified with polyclonal antibodies raised against the N proteins of Tomato spotted wilt virus (TSWV) and Impatiens necrotic spot virus (INSV) by ELISA. All samples tested positive for TSWV, but not for INSV. ELISA of thirty three isolates, using monoclonal antibodies against the N protein of TSWV, revealed the existence of five epitopes on the N protein. RT‐PCR tests on a few randomly‐selected isolates, using a pair of universal primers, a pair of primers specific for the L gene and a pair of primers specific for the N gene, as well as sequence analysis of a part of the S gene of one isolate, confirmed the authenticity of the virus isolated as TSWV. Host range studies showed differences in susceptibility, especially among species belonging to the Leguminosae and Cucurbitaceae. The species Beloporone guttata and Coleus sp. are reported for the first time as hosts of the virus, whereas Solanum melongena, Celosia cristata, Dianthus chinensis, Stephanotis floribunda and Catharanthus roseus were identified as new hosts of TSWV in Greece.
Effects of potential trap crops and planting date on soil infestation with potato cyst nematodes and root‐knot nematodes
Authors: SCHOLTE K , VOS J
Published: July 2006

In 1997 and 1998 the stimulation of hatch of potato cyst nematodes (PCN) by a trap crop was studied at various times during the growing season in a container and a field experiment. Solanum nigrum‘90‐4750‐188’was used as the trap crop in both experiments and was sown on 1 May, 16 June or 1 August in two successive years on different plots. Neither experiment revealed much seasonal variation in hatchability of PCN juveniles under a trap crop. In the container experiment, the hatch of the Globodera pallida Pa3 population was equally and strongly stimulated (89%) at all sowing dates in both years, except for the 1 August sowing in 1998 (when the hatch was 77% under extremely wet soil conditions). In the control treatment with non‐hosts (flax followed by barley) the total spontaneous hatch was 50% over 2 yr. In the field experiment, the hatch of PCN, averaged over the four populations, was also equally stimulated (71%) at all sowing dates in both years. In the control treatment with non‐hosts (flax‐barley) the total spontaneous hatch was 36% over 2 yr. Total hatch under the trap crop over 2 yr varied between the four PCN populations from 63% to 80%.

In 1998 and 1999, control of potato cyst nematodes (PCN) by the potential trap crops Solanum sisymbriifolium and S. nigrum‘90‐4750‐188’was studied in the field. Potato was also included as a trap crop. In the 1998 experiment, potato, S. sisymbriifolium and S. nigrum strongly stimulated the hatch of PCN compared with the non‐host white mustard (Sinapis alba). Roots of potato and white mustard were mainly found in the top 10 cm of soil, whereas roots of S. sisymbriifolium and S. nigrum were also abundant at depths of 10–20 cm and 20–30 cm. In the 1999 experiment, soil infestation with PCN decreased markedly with potato and S. sisymbriifolium as trap crops. In plots moderately to severely infested with 2‐yr old cysts (2–29 juveniles ml−1 air dried soil), potato reduced soil infestation by 87% and S. sisymbriifolium by 77%. In plots moderately to severely infested with 1‐yr old cysts the reductions were 74% and 60%, respectively. The reduction was least on plots very severely infested with PCN (110–242 juveniles ml−1 soil): 69% and 52% for potato and S. sisymbriifolium, respectively. Soil infestations of plots that were initially slightly to severely infested with the root‐knot nematode Meloidogyne hapla were greatly reduced under fallow and S. sisymbriifolium but increased under potato. From these and previous experiments it was concluded that, for several reasons, S. sisymbriifolium is a promising trap crop.
Effect of sowing date on the optimum plant density of winter wheat
Authors: SPINK J H , SEMERE T , SPARKES D L , WHALEY J M , FOULKES M J , CLARE R W , SCOTT R K
Published: July 2006

Pressure on financial margins in UK wheat production is driving a review of all inputs, and seed represents one of the largest financial inputs in wheat production. The potential savings through exploiting the crop's ability to compensate for reduced population are, therefore, attractive. Field experiments were carried out at ADAS Rosemaund (Herefordshire, UK) in 1996/97, 1997/98 and 1998/99 to investigate the effect of sowing date on dry matter growth and yield responses of winter wheat to reduced plant population. There were three target sowing dates (late‐Septembr, mid‐October and mid‐November), six seed rates (20, 40, 80, 160, 320 and 640 seeds m−2) and four varieties (Cadenza, Haven, Soissons and Spark). Grain yield was significantly affected by plant population with a mean reduction from 9.2 to 5.5 t ha−1 as plant number was reduced from 336 to 13 m−2. In addition, there was a significant interaction between plant density and sowing date. There was, however, no interaction between variety and plant population in terms of yield, except when lodging affected high plant populations of lodging susceptible varieties. The experiments demonstrated scope for reducing plant populations below the current target of 250–300 plants m−2; however, the degree of reduction was dependent on sowing date. Over the three years, the average economic optimum plant density was 62 plants m−2 for late‐September, 93 plants m−2 for mid‐October, and 139 plants m−2 for mid‐November sowings. Compensation for reduced population was due to increased shoot number per plant, increased grain number per ear and to a lesser extent increased grain size. Higher economic optimum plant densities at later sowing dates were due to reduced tiller production and hence ear number per plant. The other compensatory mechanisms were unaffected by sowing date.
Effects of sodium on mineral nutrition in rose plants
Authors: LORENZO H , CID M C , SIVERIO J M , RUANO M C
Published: July 2006

The effects of sodium (Na+) ion concentration on shoot elongation, uptake of ammonium (NH4+) and nitrate (NO3−) and the activities of nitrate reductase (NR) and glutamine synthetase (GS) were studied in rose plants (Rosa hybrida cv. “Lambada”).

The results showed that shoot elongation was negatively correlated with sodium concentration, although no external symptoms of toxicity were observed. Nitrate uptake decreased at high sodium levels, specifically at 30 meq litre4 of sodium. As flower development was normal under high saline conditions, this could suggest that nitrogen was being mobilised from shoot and leaf reserves. Ammonium uptake was not affected by any of the salt treatments applied probably because it diffuses through the cell membrane at low concentrations. Nitrate reductase activity was reduced by 50% at 30 meq litre 1 compared with control treatment, probably due to a decrease in the free nitrate related to nitrate uptake pattern. None of the salt treatments used affected total leaf GS activity (both chloroplastic and cytosolic isoforms) or leaf NPK mineral contents. Nitrate reductase activity in leaves increased at 10 meq litre−1 of sodium and GS activity in roots (cytosolic isoform only) followed the same pattern as NR. It is suggested that the activation of both enzymes at low salt level could be attributed to the beneficial effect of increased sulphur in the nutrient solutions.
Effects of cultivar and fungicides on stem‐base pathogens, determined by quantitative PCR, and on diseases and yield of wheat
Authors: BATEMAN G L , EDWARDS S G , MARSHALL J , MORGAN L W , NICHOLSON P , NUTTALL M , PARRY D W , SCRANCHER M , TURNER A S
Published: July 2006

The polymerase chain reaction (PCR) was used to identify and quantify all fungal pathogens of wheat (Triticum aestivum) stem bases in nine field experiments at three locations in England. The main aim was to apply quantitative PCR to provide robust data on the efficacy of new fungicides against the individual components of the stem‐base disease complex. Cyprodinil most effectively controlled eyespot by decreasing both pathogens, Tapesia yallundae and T. acuformis (the most widespread species), and sometimes contributed to increased yields. Prochloraz controlled eyespot less consistently, its effectiveness dependent mainly on the presence of T. yallundae or on rainfall events soon after application. Azoxystrobin contributed to yield increases most consistently. Although it decreased sharp eyespot and its pathogen, Rhizoctonia cerealis, these effects were insufficient to account for much of the yield increases. The effects of fungicides on eyespot were sometimes greatest on the most susceptible cultivars. Amounts of Tapesia DNA were usually consistent with cultivar susceptibility ratings. The only pathogens of brown foot rot present in significant amounts were Microdochium nivale vars nivale and majus. They appeared not to affect yield or to respond greatly to fungicides. The susceptibility of cultivars to these pathogens was sometimes similar to their susceptibility to eyespot, suggesting that they may respond to the same host resistance genes or may in some cases be secondary colonisers of eyespot‐infected plants.
Comparison of damage levels caused by Radopholus similis and Helicotylenchus multicinctus on bananas in Uganda
Authors: BAREKYE A , KASHAIJA I N , TUSHEMEREIRWE W K , ADIPALA E
Published: July 2006

Field surveys were done in 1997 and 1998 in Masaka district, Uganda, an area which is experiencing a decline in banana production, to assess level of damage caused by nematodes Radopholus similis and Helicotylenchus multicinctus at farm level. Ten farms within a radius of 2 km were selected and nematode damage assessed. The major nematodes encountered were Pratylenchus goodeyi, R. similis and H. multicinctus. P. goodeyi and H. multicinctus were more abundant than R. similis but R. similis had a stronger and significant correlation with root damage. A subsequent pot trial examined pathogenicities of R. similis and H. multicinctus in pure and mixed cultures on tissue cultured‐banana plantlets. R. similis alone and in mixed population reduced root fresh weight significantly, and the percentage of root necrosis ranged between 22.8–41.6% and 18.3–45.5% for March 1998 and March 1999 trials, respectively. The difference in damage caused by R. similis alone and in mixed population was not statistically significant, and was higher than the damage caused by H. multicinctus alone. There were no significant differences in pathogenicity among the R. similis isolates from different parts of Uganda.
The potential of some adjuvants in promoting infection with Verticillium lecanii: laboratory bioassays with Myzus persicae
Authors: WILLIAMS M E DE COURCY , EDMONDSON R N , GILL G
Published: July 2006

The potential of 14 adjuvants, including mineral oils, vegetable oils, stickers, spreaders, surfactants and nutrients, in promoting the virulence of the entomopathogenic fungus Verticillium lecanii were compared relative to a commercial formulation of the pathogen. The rate of infection over time with each adjuvant relative to the commercial formulation was tested using the peach potato aphid Myzus persicae. The proportion of infected aphids was modelled binomially with a logistic rate function assumed for the proportion infected over the time period of the experiment. Four of the adjuvant treatments, Codacide, skimmed milk, glycerol and Cutinol together with the commercial control had similar logistic slope parameters and were modelled using parallel regressions. The parallel regressions model showed significant differences between the intercepts with both glycerol and Cutinol significantly better than V. lecanii alone. Glycerol had a more positive intercept than Cutinol but the difference was not statistically significant. Although highly variable, the numbers of progeny produced by the treated aphids were significantly reduced by all the treatments relative to untreated control aphids. Glycerol and Cutinol were the only treatments that significantly reduced the number of progeny relative to the V. lecanii control.
Changes in the incidence and severity of Cassava mosaic virus disease, varietal diversity and cassava production in Uganda
Authors: OTIM‐NAPE G W , ALICAI T , THRESH J M
Published: July 2006

A survey in 1994 assessed the incidence and severity of Cassava mosaic virus disease (CMD) in Uganda and the changes that had occurred since the previous survey in 1990–92. Three counties in each of 27 districts were selected and 15 fields were assessed per county. CMD occurred in each of the 1215 fields surveyed and the overall incidence within fields was 64% compared with 52% in the same districts in 1990–92. Mean incidence differed significantly between districts and between counties within some districts. The incidence and severity of CMD had increased in 20 and 23 of the 27 districts, respectively, compared with 1990–92, indicating the continued progress of the epidemic that was first reported in Uganda in 1988. In all but three districts, there had been a decrease in the total area of cassava. The number of different varieties that predominated in one or more fields had increased in 17 districts compared with 1990–92, although the total number of varieties encountered was little changed. Ebwanateraka was again the most widely grown variety but it was recorded less frequently and predominated or was co‐dominant in only two districts in 1994 compared with seven in 1990–92. The biggest decrease in the cultivation of Ebwanateraka had occurred in districts where there was a high incidence of CMD in 1990–92.
Expression of tomato Cf genes and their corresponding avirulence genes in transgenic tobacco plants using nematode responsive promoters
Authors: BERTIOLI DAVID J , GUIMARÃES PATRICIAM , JONES JONATHON D G , THOMAS COLWYNM , BURROWS PAUL R , MONTE DAMARES C , LEAL‐BERTIOLI SORAYA C DE M
Published: July 2006

In this study two plant resistance genes, Cf‐4 and Cf‐9, were expressed in transgenic plants together with their corresponding pathogen avirulence genes Avr4 and Avr9. Three nematode responsive promoters (4xB5+A, A0.3TobRB7 and 35S) in different combinations were used to control the expression of these transgenes. According to previous descriptions of the activity of these promoters, for the promoter combinations used, co‐expression would be expected to occur only in the feeding sites of root‐knot nematodes, and not in uninfected plants. This being the case, it was predicted that transgenic plants which express a hypersensitive response, induced by nematode feeding, specifically at the feeding site could be engineered. However, transgenic plants that harbored both resistance and avirulence gene constructs underwent spontaneous necrosis, revealing new features of promoter activity. We show that the pattern of hypersensitive response was dependent upon the combination of promoters used to control the expression of the Cf and Avr genes, transgene position effects and growth conditions. Although activity of the Cf genes has only previously been reported from aerial parts of the plant, here we present evidence that both Cf‐9 and Cf‐4 are active in tobacco roots.
The potential of lentil (Lens culinaris) as a grain legume crop in the UK: an assessment based on a crop growth model
Authors: ANDREWS M , McKENZIE B A , JOYCE A , ANDREWS M E
Published: July 2006

A crop growth model developed in Canterbury, New Zealand was used to assess the potential of lentil (Lens culinaris) as a grain legume crop in the UK. The model was validated using five sowing dates at Durham (54.77°N, 1.58°W) in 1999. Predicted time to flowering was within 7 days of actual time to flowering and predicted seed yields were within 9% of actual yields. Actual yields ranged from 1.40 to 1.65 t ha‐1. Seed was of high quality.

The model was used to predict rate of development and yields of spring and autumn sown lentils at eight sites along a transect from NW Scotland (Stornoway, 58.22°N, 6.32°W) to SE England (East Mailing, 51.28°N, 0.45°E) chosen to encompass important environmental gradients in the UK. In general, for a 1 May sowing with 150 or 250 mm plant available water (PAW) and a 1 October sowing with 150 mm PAW, predicted mean values over the period 1987–95 for maximum crop growth rate, maximum leaf area index, radiation intercepted, total dry matter produced and seed yield were closely positively related to monthly mean values for mean daily air temperature and increased along the transect from NW to SE UK. Time to flowering generally decreased along the transect from NW to SE UK ranging from 28 June to 9 July and from 20 May to 14 June with the May and October sowings respectively.

For the 1 May sowing with 250 mm PAW, predicted mean seed yield ranged from 1.00 to 1.90 t ha‐1. For all sites, yield was very stable over the 9 yr period. For the 1 May sowing with 150 mm PAW, predicted mean seed yield ranged from 0.97–1.23 t ha‐1. Yields for the four more southerly sites were more variable at the lower PAW and, in exceptionally dry years, were substantially lower than average. For these sites, autumn sowing increased seed yields in exceptionally dry years and gave similar or greater mean seed yields to spring sowing with 250 mm PAW. For East Mailing, predicted yields for autumn sowing were on average 2.78 t ha‐1. Also, for Stornoway, because of its relatively high overwinter temperatures, the model predicted substantial increases in yield with autumn sowing. It is concluded that lentil has considerable potential as a grain legume crop in the UK.
Earthworm populations in conventional and integrated farming systems in the LIFE Project (SW England) in 1990–2000
Authors: HUTCHEON A , ILES D R , KENDALL D A
Published: July 2006

Dilute formalin was used to sample earthworm populations in a field experiment comparing conventional (CFS) and integrated (IFS) farming systems, at Long Ashton in SW England during 1990–2000. Crops in the CFS were established by ploughing. Those in the IFS treatments were established by non‐inversion tillage: in the first 5 yrs using a Dutzi cultivator or by direct drilling (IFS‐1); from 1994 onwards using either a Vaderstad cultivator (IFS‐2) or a Dutzi cultivator (IFS‐3). These treatments had little or no effect on earthworm populations over the first 3 yrs of the experiment, but after this time total earthworm numbers and biomass were generally greater in the IFS treatments than in the CFS.

Individual earthworm species (determined from 1995 onwards) differed in their response to the different farming systems. Numbers ofAllolobophora chlorotica, Lumbricus festivus, L. rubellus and L. terrestrisaveraged over all years were significantly greater in IFS‐3 than in CFS, with densities in IFS‐2 nearly always intermediate and not significantly different from either extreme. Average treatment differences for other species were not significant, although in most years numbers ofAporrectodea longa, Lumbricus castaneus and Octolasionspp. were greatest in IFS‐3, with IFS‐2 similar to or less than CFS. There were no consistent differences between treatments forAporrectodea caliginosa and A. rosea. Tillage method and the number of crop establishment passes were probably the main factors affecting earthworm populations, although the abundance and distribution of some species may also have been influenced by the amount of soil organic matter. During the period 1995–2000,13 species of earthworms were recorded from the site withA. caliginosaandAl. chloroticathe dominant species. These and other species which normally live in temporary burrows close to the soil surface formed about 80% of the total earthworms extracted, with the larger deep burrowing species, such asA. longaandL. terrestris, representing <20% of the total catch. Species diversity was consistently greater in the Dutzi‐based integrated system (IFS‐3) than in either the Vaderstad‐based integrated system (IFS‐2) or the conventional system (CFS). It is suggested that knowledge of the species composition of earthworm communities is essential in order to properly anticipate the likely impact of modified farming practices on earthworm populations. Careful consideration of the specific machine(s) used for tillage operations may also be required.
Factors affecting the development of Botrytis cinerea (grey mould) on linseed (Linum usitatissimum) buds, flowers and capsules
Authors: FERRYMAN S A M , FITT B D L , HAROLD J F S
Published: July 2006

A key was produced to describe 10 stages of development of linseed buds, flowers and capsules. Botrytis cinerea conidia germinated more rapidly and germ tubes grew longer on linseed stigmas, petals and mature senescing capsules than on green leaves, sepals and immature capsules. The proportion of conidia which germinated increased and the germ tubes continued growing for longer in the presence of linseed pollen and flower petal extracts. In controlled environment and field experiments, the response of buds, flowers and capsules to inoculation with B. cinerea changed with stage of development; few pre‐flowering buds developed symptoms (brown lesions, then grey mould), but high proportions of flowering and post‐flowering buds did so. Few immature green capsules developed symptoms and the proportion of capsules which developed symptoms increased as they matured. The presence of linseed pollen decreased the incubation period from inoculation with spore suspensions to appearance of B. cinerea symptoms on buds. A disease cycle was produced to suggest the changes in susceptibility of linseed to infection by B. cinerea conidia during bud, flower and capsule development.
Genetic Manipulation of Rubisco: Chromatium vinosum rbcL is expressed in Nicotiana tabacum but does not form a functional protein
Authors: MADGWICK P J , COLLIVER S P , BANKS F M , HABASH D Z , DULIEU H , PARRY M A J , PAUL M J
Published: July 2006

N. tabacum lines that lacked functional Rubisco were transformed with plasmids encoding a chloroplast transit peptide in frame with C. vinosum rbcL and stable transformants generated. However, the transgene was transcribed at a low level and no Rubisco activity or C. vinosum large subunits were detectable in any line.