Root pressure-volume curve traits capture rootstock drought tolerance

BACKGROUND AND AIMS

Living root tissues significantly constrain plant water uptake under drought, but we lack functional traits to feasibly screen diverse plants for variation in the drought responses of these tissues. Water stress causes roots to lose volume and turgor, which are crucial to root structure, hydraulics and growth. Thus, we hypothesized that root pressure-volume (p-v) curve traits, which quantify the effects of water potential on bulk root turgor and volume, would capture differences in rootstock drought tolerance.

METHODS

We used a greenhouse experiment to evaluate relationships between root p-v curve traits and gas exchange, whole-plant hydraulic conductance and biomass under drought for eight grapevine rootstocks that varied widely in drought performance in field trials (101-14, 110R, 420A, 5C, 140-Ru, 1103P, Ramsey and Riparia Gloire), grafted to the same scion variety (Vitis vinifera 'Chardonnay').

KEY RESULTS

The traits varied significantly across rootstocks, and droughted vines significantly reduced root turgor loss point (πtlp), osmotic potential at full hydration (πo) and capacitance (C), indicating that roots became less susceptible to turgor loss and volumetric shrinkage. Rootstocks that retained a greater root volume (i.e. a lower C) also maintained more gas exchange under drought. The rootstocks that previous field trials have classified as drought tolerant exhibited significantly lower πtlp, πo and C values in well-watered conditions, but significantly higher πo and πtlp values under water stress, than the varieties classified as drought sensitive.

CONCLUSIONS

These findings suggest that acclimation in root p-v curve traits improves gas exchange in persistently dry conditions, potentially through impacts on root hydraulics or root to shoot chemical signalling. However, retaining turgor and volume in previously unstressed roots, as these roots deplete wet soil to moderately negative water potentials, could be more important to drought performance in the deep, highly heterogenous rooting zones which grapevines develop under field conditions.

Genetic characterization of Vitis germplasm collected from the southwestern US and Mexico to expedite Pierce's disease-resistance breeding

Pierce's disease (PD) limits the cultivation of Vitis vinifera grape cultivars in California, across the southern United States and into South America. Resistance has been well characterized in V. arizonica, and one resistance locus has been identified (PdR1). However, resistance is poorly characterized in most other grape species. We tested a wide range of Vitis species from the southwestern United States for resistance to PD and used nuclear and chloroplast markers to phenotypically and genetically select a diverse set of resistant accessions. Chloroplast SSR markers identified 11 maternal lineage lines within the set of 17 (14 new and three previously identified) PD resistant accessions. A total of 19 breeding populations (F1 and pseudo-BC1) were developed with the 14 PD resistant accessions, and a total of 705 seedlings were analyzed for PD resistance. Using a limited mapping approach, 12 SSR markers, linked to the PdR1 locus, were used to genotype the breeding populations and phenotypic data were analyzed. Nine accessions had a major resistance quantitative trait locus (QTL) within the genomic region containing PdR1. The phenotypic data for these three resistant accessions, ANU67, b41-13, and T03-16, did not associate with PdR1 linked markers, indicating that their resistance is located in other regions of the genome. These three accessions were identified as candidates for use in the development of framework maps with larger populations capable of detecting additional and unique loci for PD resistance breeding and the stacking of PD resistance genes.

The Unilateral Swollen Lower Limb: Etiology, Investigation, and Management

The swollen lower limb, a common finding in routine clinical practice, is clinically challenging. The cause underlying this problem is often multifactorial, and its management may involve different specialties. It is important, though difficult, to avoid unnecessary and expensive investigations. The aim of this article is to provide an overview of the management of this problem by addressing the common causes, methods of assessment, diagnosis, and therapeutic options.

Coenzyme Q10 and immunity: A case report and new implications for treatment of recurrent infections in metabolic diseases

Coenzyme Q10 (CoQ10) deficiency can manifest diversely, from isolated myopathy to multisystem involvement. Immune dysregulation has not been reported as a feature of the disease. We report a four-year old girl with failure to thrive, recurrent infections, developmental delay with hypotonia, and CoQ10 deficiency with impaired immune function, which improved after CoQ10 and immunoglobulin replacement therapy. Immune dysfunction in CoQ10 deficiency should be considered and treated appropriately.

Genetic dissection of agronomic traits within a segregating population of breeding table grapes

Grapes (Vitis vinifera) are of great economic importance worldwide. We genetically dissected a table grape breeding population, using hidden Markov models (HMM) applied to quantitative trait locus (QTL) analyses. We evaluated and dissected the following traits: total number of clusters, leaf score, peduncle length, cluster length, number of berries, weight of 10 berries, average seed number, nature of seeds, berry skin color, soluble solids, titratable acidity, and berry anthocyanin. A consensus map was developed with 255 SSR molecular markers, ordered into 19 linkage groups. The observed length of this map was 1871.4 cM, with 89.7% coverage. QTL were identified using interval mapping with HMM. The number of QTL detected for each trait varied between 1 and 8, reflecting the quantitative nature of these traits. The percentage of variation explained by these QTL was small, varying between 1.56 and 11.98%. We found QTL across linkage groups 2, 7, 12, 13, and 14 for berry anthocyanin.

Soil Temperature Effects on the Interaction of Grape Rootstocks and Plant-parasitic Nematodes

Resistance to Meloidogyne spp. in commonly used resistant grape rootstocks is slightly compromised at soil temperatures above 27°C. Newly released UCD-GRN series rootstocks, which have broad nematode resistance, exhibit trace infections by Meloidogyne spp. at elevated temperature. Pathotypes of M. incognita and M. arenaria that are virulent on 'Harmony' rootstock, as well as M. incognita Race 3, which is avirulent on 'Harmony', failed to produce egg masses on the UCD-GRN series rootstocks and other resistant selections at 24°C. At 27°C and above, there was increased nematode galling and egg mass production; at 30°C, egg mass production levels of M. incognita Race 3 on 'Harmony' were up to 12% of that on susceptible 'Colombard' while reproduction of the virulent pathotypes on the UCD-GRN series was less than 5% of that on 'Colombard'. Resistance of several of the parental genotypes of the UCD-GRN rootstock series was slightly compromised at soil temperatures of 30°C and above; however, others maintained their resistance to even the virulent M. arenaria pathotype A at high temperatures. Effects of high temperature on resistance to Xiphinema index could not be assessed because of temperature sensitivity of the nematodes while resistance to Mesocriconema xenoplax was not compromised at high soil temperature. Resistance to Meloidogyne spp. in the UCD-GRN series rootstocks was not compromised when plants and nematodes were subjected to cyclical high and low temperature conditions, indicating that once initiated, the resistance mechanism is not reversed.

Resistance of Grape Rootstocks to Plant-parasitic Nematodes

Candidate grape rootstocks were selected through a rigorous screening program initiated with important sources of resistance to Meloidogyne pathotypes and to Xiphinema index in Muscadinia rotundifolia and Vitis species native to North America. Based on their rooting capability and horticultural characteristics, 200 candidates were selected from 5,000 progeny of multiple crosses between commercial grape rootstocks and wild grape species that exhibited resistance to nematodes. After a 15-year screening process, 13 selections emerged with either almost complete or complete combined resistance to M. incognita Race 3, M. incognita pathotype Harmony C, M. arenaria pathotype Harmony A, and X. index, important nematode pests of grapevines. Durability of this broad resistance was tested by challenging the selections with the target nematodes in combination and with the target nematodes in combinations with species not included in the screening process. Durability of resistance of the candidate rootstocks was also tested by exposure to the nematode communities of infested field soils from different locations. Breadth of resistance was determined on the basis of their host status to non-target nematodes, including Mesocriconema xenoplax, Pratylenchus vulnus, Tylenchulus semipenetrans and Paratylenchus hamatus. After a total of 204 separate trials, the rootstocks were released to the grape industry as UCD GRN1, UCD GRN2, UCD GRN3, UCD GRN4, and UCD GRN5. We provide a compilation of current knowledge of the host status of these five newly released rootstocks and of 27 other rootstock cultivars to plant-parasitic nematodes.

The relationship between root hydraulics and scion vigour across Vitis rootstocks: what role do root aquaporins play?

Vitis vinifera scions are commonly grafted onto rootstocks of other grape species to influence scion vigour and provide resistance to soil-borne pests and abiotic stress; however, the mechanisms by which rootstocks affect scion physiology remain unknown. This study characterized the hydraulic physiology of Vitis rootstocks that vary in vigour classification by investigating aquaporin (VvPIP) gene expression, fine-root hydraulic conductivity (Lp(r)), % aquaporin contribution to Lp(r), scion transpiration, and the size of root systems. Expression of several VvPIP genes was consistently greater in higher-vigour rootstocks under favourable growing conditions in a variety of media and in root tips compared to mature fine roots. Similar to VvPIP expression patterns, fine-root Lp(r) and % aquaporin contribution to Lp(r) determined under both osmotic (Lp(r)(Osm)) and hydrostatic (Lp(r)(Hyd)) pressure gradients were consistently greater in high-vigour rootstocks. Interestingly, the % aquaporin contribution was nearly identical for Lp(r)(Osm) and Lp(r)(Hyd) even though a hydrostatic gradient would induce a predominant flow across the apoplastic pathway. In common scion greenhouse experiments, leaf area-specific transpiration (E) and total leaf area increased with rootstock vigour and were positively correlated with fine-root Lp(r). These results suggest that increased canopy water demands for scion grafted onto high-vigour rootstocks are matched by adjustments in root-system hydraulic conductivity through the combination of fine-root Lp(r) and increased root surface area.

A framework genetic map of Muscadinia rotundifolia

This study presents a framework linkage map based on microsatellite markers for Muscadinia rotundifolia (1n = 20). The mapping population consisted of 206 progeny generated from a cross of two M. rotundifolia varieties, 'Fry' and 'Trayshed'. A total of 884 primers were tested for their ability to amplify markers: 686 amplified and 312 simple sequence repeat (SSR) primer pairs generated 322 polymorphic markers for either one or both parents. The map for the female parent 'Fry' consisted of 212 markers and covered 879 cM on 18 chromosomes. The average distance between the markers was 4.1 cM and chromosome 6 was not represented due to a lack of polymorphic markers. The map for the male parent 'Trayshed' consisted of 191 markers and covered 841 cM on 19 chromosomes. The consensus map consisted of 314 markers on 19 chromosomes with a total distance of 1,088 cM, which represented 66 % of the distance covered by the Vitis vinifera reference linkage map. Marker density varied greatly among chromosomes from 5 to 35 mapped markers. Relatively good synteny was observed across 19 chromosomes based on markers in common with the V. vinifera reference map. Extreme segregation distortion was observed for chromosome 8 and 14 on the female parent map, and 4 on the male parent map. The lack of mapping coverage for the 20th M. rotundifolia chromosome is discussed in relation to possible evolutionary events that led to the reduction in chromosome number from 21 to 19 in the ancestral genome.

Balloon-expandable stent deformation during deployment into the iliac artery: a procedural complication managed conservatively

The management of aortoiliac insufficiency has been improved considerably since the introduction of balloon-expandable stents in 1991. Although numerous studies have shown the safety and efficacy of balloon-expandable iliac artery stent placement, the procedure is not without potential complication. We report here a very unusual case of iliac artery stenting being complicated by deformation and elongation of the stent following balloon rupture at initial deployment with retention of the distal balloon marker and our successful approach to subsequent management with combined acetylsalicylic acid and clopidogrel. In conclusion, this conservative approach may be an alternative treatment of a partially deployed aortoiliac stent with a retained foreign body when further intervention is considered to be of high risk.

Evaluation of genetic dissimilarity in a segregating wine grape population

This study examined the genetic diversity present in a population obtained by crossing two very distinctive varieties of wine grapes (142 progeny from a Riesling x Cabernet Sauvignon cross, including both parents, created at the University of California). The following list of morphological characters were evaluated and found to segregate in this population: cluster weight, cluster length, presence or absence of cluster wings, cluster wing length, number of berries, cluster density (CD), and berry weight. The following juice parameters were also measured: °Brix, pH, total phenolics, and titratable acidity. Genetic diversity within this population was estimated through multivariate methods that utilized the Gower index of dissimilarity and UPGMA clustering. The correlations between traits and relative contribution of each variable were also compared. Eleven groups of progeny were distinguished into categories with low, intermediate and high values for cluster weight and cluster density, and low and high values for total phenolics. An inverse correlation was detected between the variables related to production and those related to the quality of the fruit. Principal components analysis demonstrated that all variables examined in this study are important for the correct discrimination of optimal genotypes in this population. These statistical tools can be used to select individuals with the greatest potential for producing high-quality wines.

Using a limited mapping strategy to identify major QTLs for resistance to grapevine powdery mildew (Erysiphe necator) and their use in marker-assisted breeding

A limited genetic mapping strategy based on simple sequence repeat (SSR) marker data was used with five grape populations segregating for powdery mildew (Erysiphe necator) resistance in an effort to develop genetic markers from multiple sources and enable the pyramiding of resistance loci. Three populations derived their resistance from Muscadinia rotundifolia 'Magnolia'. The first population (06708) had 97 progeny and was screened with 137 SSR markers from seven chromosomes (4, 7, 9, 12, 13, 15, and 18) that have been reported to be associated with powdery or downy mildew resistance. A genetic map was constructed using the pseudo-testcross strategy and QTL analysis was carried out. Only markers from chromosome 13 and 18 were mapped in the second (04327) and third (06712) populations, which had 47 and 80 progeny, respectively. Significant QTLs for powdery mildew resistance with overlapping genomic regions were identified for different tissue types (leaf, stem, rachis, and berry) on chromosome 18, which distinguishes the resistance in 'Magnolia' from that present in other accessions of M. rotundifolia and controlled by the Run1 gene on chromosome 12. The 'Magnolia' resistance locus was termed as Run2.1. Powdery mildew resistance was also mapped in a fourth population (08391), which had 255 progeny and resistance from M. rotundifolia 'Trayshed'. A locus accounting for 50% of the phenotypic variation mapped to chromosome 18 and was named Run2.2. This locus overlapped the region found in the 'Magnolia'-based populations, but the allele sizes of the flanking markers were different. 'Trayshed' and 'Magnolia' shared at least one allele for 68% of the tested markers, but alleles of the other 32% of the markers were not shared indicating that the two M. rotundifolia selections were very different. The last population, 08306 with 42 progeny, derived its resistance from a selection Vitis romanetii C166-043. Genetic mapping discovered a major powdery mildew resistance locus termed Ren4 on chromosome 18, which explained 70% of the phenotypic variation in the same region of chromosome 18 found in the two M. rotundifolia resistant accessions. The mapping results indicate that powdery mildew resistance genes from different backgrounds reside on chromosome 18, and that genetic markers can be used as a powerful tool to pyramid these loci and other powdery mildew resistance loci into a single line.

Fine-scale genetic mapping of two Pierce's disease resistance loci and a major segregation distortion region on chromosome 14 of grape

A refined genetic map of chromosome 14, which contains the Pierce's disease (PD) resistance locus, was created from three grape mapping populations. The source of PD resistance in these populations was b43-17, a male form of Vitis arizonica Engelm. that is homozygous resistant. The resistance locus segregated as a single dominant gene and mapped as PdR1a in the F1 selection F8909-17 (9621 population) and as PdR1b in a sibling F1 selection F8909-08 (04190 population). These two full sibs inherited either allele of the Pierce's disease resistance locus from the b43-17 parent, which is homozygous at that locus. The 9621 population consisted of 425 progeny and PdR1a mapped between markers VvCh14-56/VvCh14-02 and UDV095 within a 0.6 cM genetic distance. The 04190 population consisted of 361 progeny and PdR1b mapped between markers VvCh14-02 and UDV095/VvCh14-10 within a 0.4 cM distance. Many of the markers present on chromosome 14 were distorted with an excess of female alleles in the 04190 and 04373 population (developed from a cross of V. vinifera L. F2-35 x b43-17) indicating that potential gametophytic factors are present in this region. Common markers from this region within the 9621 population were not distorted except Scu15. When these markers were compared to V. vinifera-based maps of chromosome 14 they were also distorted suggesting the involvement of gametophytic factors, and prompting the identification of this region as Vitis-segregation distortion region 1 (V-SDR1). The refined genetic maps developed from this study can be used to identify and clone genes that confer resistance to Pierce's disease.

Genetic and QTL analysis of resistance to Xiphinema index in a grapevine cross

Resistance to the dagger nematode Xiphinema index has been an important objective in grape rootstock breeding programs. This nematode not only causes severe feeding damage to the root system, but it also vectors grapevine fanleaf virus (GFLV), the causal agent of fanleaf degeneration and one of the most severe viral diseases of grape. The established screening procedures for dagger nematode resistance are time consuming and can produce inconsistent results. A fast and reliable greenhouse-based system for screening resistance to X. index that is suitable for genetic studies and capable of evaluating breeding populations is needed. In this report, the dynamics of nematode numbers, gall formation, and root weight loss were investigated using a variety of soil mixes and pot sizes over a 52-week period. Results indicated that the number of galls formed was correlated with the size of the nematode population and with the degree of root weight loss. After inoculation with 100 nematodes, gall formation could be reliably evaluated in 4-8 weeks in most plant growth conditions and results were obtained 6 months more rapidly than past evaluation methods. This modified X. index resistance screening method was successfully applied to 185 of the 188 F(1) progeny from a cross of D8909-15 x F8909-17 (the 9621 population), which segregates for a form of X. index resistance originally derived from Vitis arizonica. Quantitative trait loci (QTL) analysis was carried out on both parental genetic maps of 255 markers using MapQTL 4.0. Results revealed that X. index resistance is controlled by a major QTL, designated Xiphinema index Resistance 1 (XiR1), near marker VMC5a10 on chromosome 19. The XiR1 QTL was supported by a LOD score of 36.9 and explained 59.9% of the resistance variance in the mapping population.

Individual and Domain Adaptation in Sentence Planning for Dialogue

One of the biggest challenges in the development and deployment of spoken dialogue systems is the design of the spoken language generation module. This challenge arises from the need for the generator to adapt to many features of the dialogue domain, user population, and dialogue context. A promising approach is trainable generation, which uses general-purpose linguistic knowledge that is automatically adapted to the features of interest, such as the application domain, individual user, or user group. In this paper we present and evaluate a trainable sentence planner for providing restaurant information in the MATCH dialogue system. We show that trainable sentence planning can produce complex information presentations whose quality is comparable to the output of a template-based generator tuned to this domain. We also show that our method easily supports adapting the sentence planner to individuals, and that the individualized sentence planners generally perform better than models trained and tested on a population of individuals. Previous work has documented and utilized individual preferences for content selection, but to our knowledge, these results provide the first demonstration of individual preferences for sentence planning operations, affecting the content order, discourse structure and sentence structure of system responses. Finally, we evaluate the contribution of different feature sets, and show that, in our application, n-gram features often do as well as features based on higher-level linguistic representations.

Using Linguistic Cues for the Automatic Recognition of Personality in Conversation and Text

It is well known that utterances convey a great deal of information about the speaker in addition to their semantic content. One such type of information consists of cues to the speaker's personality traits, the most fundamental dimension of variation between humans. Recent work explores the automatic detection of other types of pragmatic variation in text and conversation, such as emotion, deception, speaker charisma, dominance, point of view, subjectivity, opinion and sentiment. Personality affects these other aspects of linguistic production, and thus personality recognition may be useful for these tasks, in addition to many other potential applications. However, to date, there is little work on the automatic recognition of personality traits. This article reports experimental results for recognition of all Big Five personality traits, in both conversation and text, utilising both self and observer ratings of personality. While other work reports classification results, we experiment with classification, regression and ranking models. For each model, we analyse the effect of different feature sets on accuracy. Results show that for some traits, any type of statistical model performs significantly better than the baseline, but ranking models perform best overall. We also present an experiment suggesting that ranking models are more accurate than multi-class classifiers for modelling personality. In addition, recognition models trained on observed personality perform better than models trained using self-reports, and the optimal feature set depends on the personality trait. A qualitative analysis of the learned models confirms previous findings linking language and personality, while revealing many new linguistic markers.

Visual documentation of ovine pituitary gland development with magnetic resonance imaging following zeranol treatment

The objective of the current study was to determine whether magnetic resonance imaging (MRI) could be successfully utilized to document the effect of an oestrogenic anabolic agent on pituitary gland growth. The experimental animals consisted of two 1/2 sibling Suffolk wethers (castrated rams), which received either no implant (control, n = 1) or a 24 mg zeranol implant at day 0 and day 42 (zeranol; n = 1). Animals were anaesthetized with propofol and supported with oxygen during the MRI procedure. A mobile MRI unit with a 0.5 tesla (T), superconducting magnet was used to obtain 3 mm thick, non-contrast enhanced, T1-weighted (TR 500-600, TE25) sagittal, transverse and dorsal images of the pituitary gland. Sagittal images were recorded only when the mesencephalic aqueduct and infundibulum were distinctly visible in the same image. Pituitary glands were imaged at 14-day intervals for 70 days to determine if and when the anabolic effects of zeranol on pituitary gland growth could be visualized using MRI techniques. Three separate measurements of the pituitary gland dimensions made with the on-screen cursor were averaged to calculate pituitary gland dimensions and volume. A computer-assisted image analysis system and laser film images were used to determine pituitary gland area. Increases in pituitary gland volume for control and zeranol-treated animals were evident within 14 days, and by the end of the 70-day study, the increase in pituitary volume for the zeranol-treated animal was three times greater than that of the control animal. Overall, our results indicate that MRI technology can be successfully used to document the development of the pituitary gland in vivo. Application of knowledge gained from this novel approach to study the growth, development and function of endocrine glands over time, and within the same animal, will enhance human and animal endocrine diagnostic procedures.

Refined mapping of the Pierce's disease resistance locus, PdR1, and Sex on an extended genetic map of Vitis rupestris x V. arizonica

A framework genetic map based on genomic DNA-derived SSR, EST-derived SSR, EST-STS and EST-RFLP markers was developed using 181 genotypes generated from D8909-15 (female) x F8909-17 (male), the '9621' population. Both parents are half siblings with a common female parent, Vitis rupestris 'A. de Serres', and different male parents (forms of V. arizonica). A total of 542 markers were tested, and 237 of them were polymorphic for the female and male parents. The female map was developed with 159 mapped markers covering 865.0 cM with an average marker distance of 5.4 cM in 18 linkage groups. The male map was constructed with 158 mapped molecular markers covering 1055.0 cM with an average distance of 6.7 cM in 19 linkage groups. The consensus '9621' map covered 1154.0 cM with 210 mapped molecular markers in 19 linkage groups, with average distance of 5.5 cM. Ninety-four of the 210 markers on the consensus map were new. The 'Sex' expression locus segregated as single major gene was mapped to linkage group 2 on the consensus and the male map. PdR1, a major gene for resistance to Pierce's disease, caused by the bacterium Xylella fastidiosa, was mapped to the linkage group 14 between markers VMCNg3h8 and VVIN64, located 4.3 and 2.7 cM away from PdR1, respectively. Differences in segregation distortion of markers were also compared between parents, and three clusters of skewed markers were observed on linkage groups 6, 7 and 14.

Phase I study of intravenous CCI-779 in combination with bryostatin-1 in solid tumors

3067

Background: mTOR regulates translation of messenger RNA critical for angiogenesis and cell growth. CCI-779 inhibits mTOR signaling through p70S6 kinase (S6K), which phosphorylates the ribosomal S6 protein (S6). CCI-779 is active in renal carcinoma (RCC) and other solid tumors. Based on our finding that bryostatin-1 (bryo) inhibits S6K, and that CCI-779 + Bryo additively inhibit S6K and RCC growth in vitro, we initiated a phase I trial to determine the maximum tolerable (MTD) doses and dose-limiting toxicities of this novel combination in patients with solid tumors. Methods: Bryo (20 μg/m2) was administered over 60 minutes IV followed by CCI-779 (10 and 15 mg, planned escalation to 75 mg) IV over 30 minutes, both weekly for 3 of 4 weeks. Serum and peripheral blood mononuclear cell (PBMC) samples were collected for analysis of pharmacokinetics and markers of mTOR inhibition (phospho-S6 and p21waf1). Results: Nine patients (median age 57, 6 RCC, 2 sarcoma and 1 neuroendocrine) are evaluable for toxicity (total cycles=27 cycles, median 4, range 1–7) at the initial 2 dose levels (Bryo 20 μg/m2, CCI-779 10 mg and 15 mg). Cycle 1 toxicity includes grade 3 hypophosphatemia and myelosuppression in one patient each and grade 2 fatigue, stomatitis, and anemia. One patient developed reversible grade 3 pneumonitis after 7 cycles. Of 7 patients with therapy-resistant disease, 5 (4 RCC and 1 sarcoma) had stable disease lasting up to 7 months. A therapy-naive patient with RCC has 23% tumor reduction after 2 cycles at dose level 2 (CCI-779=15 mg). PBMC proteins from 5 patients show consistent decreases in phospho-S6 at 2–6 hours-post treatment compared with pre-treatment baseline measurement, with recovery by 24–72 hours after dosing. In parallel with inhibition of phosphorylation of S6, PBMC levels of p21waf1 were completely inhibited in all 5 patients. Conclusions: The combination of bryo and CCI-779 is feasible, with antitumor activity in RCC and mTOR pathway inhibition observed at submaximal doses. Dose escalation is continuing.

No significant financial relationships to disclose.

Genetic linkage map of the interspecific grape rootstock cross Ramsey (Vitis champinii) x Riparia Gloire (Vitis riparia)

The first genetic linkage map of grape derived from rootstock parents was constructed using 188 progeny from a cross of Ramsey (Vitis champinii) x Riparia Gloire (V. riparia). Of 354 simple sequence repeat markers tested, 205 were polymorphic for at least one parent, and 57.6% were fully informative. Maps of Ramsey, Riparia Gloire, and the F1 population were created using JoinMap software, following a pseudotestcross strategy. The set of 205 SSRs allowed for the identification of all 19 Vitis linkage groups (2n=38), with a total combined map length of 1,304.7 cM, averaging 6.8 cM between markers. The maternal map consists of 172 markers aligned into 19 linkage groups (1,244.9 cM) while 126 markers on the paternal map cover 18 linkage groups (1,095.5 cM). The expected genome coverage is over 92%. Segregation distortion occurred in the Ramsey, Riparia Gloire, and consensus maps for 10, 13, and 16% of the markers, respectively. These distorted markers clustered primarily on the linkage groups 3, 5, 14 and 17. No genome-wide difference in recombination rate was observed between Ramsey and Riparia Gloire based on 315 common marker intervals. Fifty-four new Vitis-EST-derived SSR markers were mapped, and were distributed evenly across the genome on 16 of the 19 linkage groups. These dense linkage maps of two phenotypically diverse North American Vitis species are valuable tools for studying the genetics of many rootstock traits including nematode resistance, lime and salt tolerance, and ability to induce vigor.

Identification and molecular mapping of PdR1, a primary resistance gene to Pierce's disease in Vitis

A major quantitative trait locus (QTL) controlling resistance to Pierce's disease (PD) of grape, caused by the bacterium Xylella fastidiosa (Xf), was identified on a Vitis linkage map and denoted as 'Pierce's disease resistance 1' (PdR1). Placement of the locus was accomplished by evaluating a family of full-sib progeny from a cross of two PD-resistant interspecific hybrids with resistance inherited from Vitis arizonica. Resistance was measured under greenhouse conditions by direct quantification of Xf numbers in stem tissues as well as by evaluation of disease symptoms based on leaf scorch and a cane maturation index (CMI). A large QTL (LOD 17.2) accounting for 72% of the phenotypic variance in bacterial numbers was localized to linkage group 14 of the male parent F8909-17. The approximate 95% confidence interval around the QTL peak extended 5.7 cM when using composite interval mapping. The other disease evaluation methods (leaf scorch and CMI, respectively) placed the resistance QTL to the same region on linkage group 14, although at wider 95% confidence intervals (6.0 and 7.5 cM), lower peak LOD scores (11.9 and 7.7) and accounting for less phenotypic variance (59 and 42%). This is the first report of an Xf resistance QTL mapped in any crop species. The relevance of the markers located in the region spanning the QTL will be discussed, addressing their usefulness for the development of PD-resistant grape cultivars.

The continued value of central histopathological review of testicular tumours

AIMS

Central histopathological review of testicular tumours prior to definitive treatment can have an important impact on patient management. This study was designed to assess the continued value of central review in the light of increasing subspecialization and increased numbers of consultant histopathologists.

MATERIALS AND RESULTS

The original and review reports of 291 testicular cancer specimens from 1998 to 2002 were analysed, looking particularly at major diagnosis, vascular invasion and the tumour elements within non-seminomatous germ cell tumours (NSGCT). When a diagnosis was altered any effect on subsequent patient management was assessed. There was a discrepancy in tumour type in 11 cases (4%) compared with 6% in 1992-1997. The commonest change was from seminoma to NSGCT or combined germ cell tumour (5/11). There was also diagnostic difficulty with spermatocytic seminoma (3/11). The clinical management of all 11 cases was influenced as a result of the review diagnosis. Discrepancies in vascular invasion were noted in 13 of the 126 NSGCTs (10%) compared with 20% in 1992-1997. Differences in NSGCT tumour elements, though clinically less important, were frequent in both groups.

CONCLUSIONS

There continues to be a small number of significant and clinically important errors identified following central histopathological review of testicular tumours. This study highlights the value of central review and supports its continued practice in the management of testicular tumours.

Learning Content Selection Rules for Generating Object Descriptions in Dialogue

A fundamental requirement of any task-oriented dialogue system is the ability to generate object descriptions that refer to objects in the task domain. The subproblem of content selection for object descriptions in task-oriented dialogue has been the focus of much previous work and a large number of models have been proposed. In this paper, we use the annotated COCONUT corpus of task-oriented design dialogues to develop feature sets based on Dale and Reiter's (1995) incremental model, Brennan and Clark's (1996) conceptual pact model, and Jordan's (2000b) intentional influences model, and use these feature sets in a machine learning experiment to automatically learn a model of content selection for object descriptions. Since Dale and Reiter's model requires a representation of discourse structure, the corpus annotations are used to derive a representation based on Grosz and Sidner's (1986) theory of the intentional structure of discourse, as well as two very simple representations of discourse structure based purely on recency. We then apply the rule-induction program RIPPER to train and test the content selection component of an object description generator on a set of 393 object descriptions from the corpus. To our knowledge, this is the first reported experiment of a trainable content selection component for object description generation in dialogue. Three separate content selection models that are based on the three theoretical models, all independently achieve accuracies significantly above the majority class baseline (17%) on unseen test data, with the intentional influences model (42.4%) performing significantly better than either the incremental model (30.4%) or the conceptual pact model (28.9%). But the best performing models combine all the feature sets, achieving accuracies near 60%. Surprisingly, a simple recency-based representation of discourse structure does as well as one based on intentional structure. To our knowledge, this is also the first empirical comparison of a representation of Grosz and Sidner's model of discourse structure with a simpler model for any generation task.

Inheritance of resistance to Xylella fastidiosa within a Vitis rupestris x Vitis arizonica hybrid population

The inheritance of resistance to Xylella fastidiosa (Xf), the bacterium which causes Pierce's disease (PD) in grapevines, was evaluated within a factorial mating design consisting of 16 full-sib families with resistance derived from Vitis arizonica interspecific hybrids. Measurements of disease progression under greenhouse conditions were based on quantitative assessment of Xf populations in stem tissues and on three phenotypic scores: leaf scorch, a cane maturation index (CMI) and an index that incorporated shoot stunting into the cane maturation index (CMSSI). Measurement of bacterial populations yielded the highest broad-sense heritability for resistance on a genotype mean basis (0.97), indicating that this measure of resistance was the least effected by environmental variation. Narrow-sense heritability of PD resistance was moderately high and measured 0.52, 0.60, 0.63 and 0.37 for Xf populations, CMI scores, CMSSI scores and leaf scorch values, respectively. Complex segregation analysis using the computer program Statistical Analysis for Genetic Epidemiology (SAGE: ) strongly indicated the existence of a major gene for PD resistance, which accounted for 91% of the total genetic variance. Conversion of the quantitative data into qualitative resistance levels and evaluation via a chi-square analysis showed that 15 of the 16 families segregated in accordance with a single gene hypothesis with a dominant allele controlling PD resistance. These data indicate that the trait should be relatively easy to pass on from parents to progeny in a breeding program for the development of PD-resistant grape cultivars, particularly when selection is based on cane maturation scores or stem Xf populations.

Vitis Resistance to Pierce's Disease Is Characterized by Differential Xylella fastidiosa Populations in Stems and Leaves

ABSTRACT The pattern of Xylella fastidiosa infection in resistant and susceptible grapevines representing a diverse selection of Vitis spp. was characterized through measurements of X. fastidiosa bacterial movement and accumulation in artificially inoculated greenhouse-grown grapevines. A double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) was optimized for quantification of X. fastidiosa populations and tested on known amounts of X. fastidiosa added to grape tissue extracts. Predicted versus known X. fastidiosa concentrations proved to be highly correlated (R(2) = 0.99). Populations of X. fastidiosa in stem internode, stem node, petiole, and leaf blade samples from the genotypes in this study were measured at 12 weeks postinoculation using the optimized ELISA procedure. Samples from each plant part were taken at eight positions along the inoculated shoots. Systemic infection was detected in both susceptible and resistant genotypes. Resistant genotypes were characterized by significant differences in X. fastidiosa populations between stem internodes and leaves (1.0 x 10(6) and 1.1 x 10(7) cells/g of sample, respectively). In contrast, the susceptible genotypes were characterized by high mean X. fastidiosa populations in both stems and leaves (5.6 x 10(7) and 4.8 x 10(7) cells/g, respectively) the latter of which were not significantly different from the resistant genotypes. A high correlation (R(2) = 0.97) between stem X. fastidiosa numbers to previously characterized field Pierce's disease (PD) performance indicates that the quantitative ELISA measurements of X. fastidiosa in greenhouse-grown grapevines should be a useful tool for predicting PD resistance under field conditions.

Development and Comparison of Symptom Indices for Quantifying Grapevine Resistance to Pierce's Disease

ABSTRACT Symptoms of Pierce's disease (PD) were assessed under greenhouse conditions on field-resistant and field-susceptible grapevines in order to characterize the PD resistance phenotype in the genus Vitis. A cane maturation index (CMI) was developed to quantify the green-islands symptom, which was measured at 12 weeks post-bacterial inoculation, along with leaf scorch and percentage of xylem vessels blocked by occlusions. Canes of resistant genotypes matured normally and had a significantly lower CMI score of 0.9 (on a 0-to-6 scale) compared with 5.1 for the susceptible genotypes. The CMI scoring method had a high correlation (R(2) = 0.91) with previously characterized field performance, whereas leaf scorch had only a moderate correlation (R(2) = 0.51) with field performance. Average scorched area on leaves of the susceptible and resistant genotypes was 80 and 48%, respectively, demonstrating that leaf scorch can be extensive in resistant genotypes under the presented screening conditions, and suggesting that systemic infection can occur in all evaluated genotypes. Occlusions within both stem and petiole vessels were composed principally of tyloses and were significantly higher in petioles than in stems of either resistant or susceptible backgrounds. Susceptible genotypes displayed a higher level of stem tylose occlusions relative to resistant genotypes, but correlation to field performance was low (R(2) = 0.13). Ease of use and high correlation to field performance makes CMI scoring a better choice for PD resistance evaluations relative to other phenotypic symptom assessments.

A genetic linkage map of grape, utilizing Vitis rupestris and Vitis arizonica

A genetic linkage map of grape was constructed, utilizing 116 progeny derived from a cross of two Vitis rupestris x V. arizonica interspecific hybrids, using the pseudo-testcross strategy. A total of 475 DNA markers-410 amplified fragment length polymorphism, 24 inter-simple sequence repeat, 32 random amplified polymorphic DNA, and nine simple sequence repeat markers-were used to construct the parental maps. Markers segregating 1:1 were used to construct parental framework maps with confidence levels >90% with the Plant Genome Research Initiative mapping program. In the maternal (D8909-15) map, 105 framework markers and 55 accessory markers were ordered in 17 linkage groups (756 cM). The paternal (F8909-17) map had 111 framework markers and 33 accessory markers ordered in 19 linkage groups (1,082 cM). One hundred eighty-one markers segregating 3:1 were used to connect the two parental maps' parents. This moderately dense map will be useful for the initial mapping of genes and/or QTL for resistance to the dagger nematode, Xiphinema index, and Xylella fastidiosa, the bacterial causal agent of Pierce's disease.

Size of hippocampal pyramidal neurons in schizophrenia

BACKGROUND

Meta-analyses of hippocampal size have indicated that this structure is smaller in schizophrenia. This could reflect a reduction in the size of constituent neurons or a reduced number of neurons.

AIMS

To measure the size of hippocampal pyramidal neurons in the brains of people with and without schizophrenia.

METHOD

Pyramidal neuron size in hippocampal subfields was estimated stereologically from sections taken at 5 mm intervals throughout the whole length of right and left hippocampi from the brains of 13 people with schizophrenia and 16 controls. Results were assessed using repeated-measures analysis of covariance looking for a main effect of diagnosis and gender, and interactions of these with side.

RESULTS

We were unable to detect significant differences related to diagnosis, gender or side for any hippocampal subfield for this series of cases.

CONCLUSIONS

For this series of brains, hippocampal cell size is unchanged in schizophrenia.

Comparative analyses of multi-species sequences from targeted genomic regions

The systematic comparison of genomic sequences from different organisms represents a central focus of contemporary genome analysis. Comparative analyses of vertebrate sequences can identify coding and conserved non-coding regions, including regulatory elements, and provide insight into the forces that have rendered modern-day genomes. As a complement to whole-genome sequencing efforts, we are sequencing and comparing targeted genomic regions in multiple, evolutionarily diverse vertebrates. Here we report the generation and analysis of over 12 megabases (Mb) of sequence from 12 species, all derived from the genomic region orthologous to a segment of about 1.8 Mb on human chromosome 7 containing ten genes, including the gene mutated in cystic fibrosis. These sequences show conservation reflecting both functional constraints and the neutral mutational events that shaped this genomic region. In particular, we identify substantial numbers of conserved non-coding segments beyond those previously identified experimentally, most of which are not detectable by pair-wise sequence comparisons alone. Analysis of transposable element insertions highlights the variation in genome dynamics among these species and confirms the placement of rodents as a sister group to the primates.

A postmortem study of the mediodorsal nucleus of the thalamus in schizophrenia

Four studies have reported that the mediodorsal nucleus of the thalamus (MD) is smaller and contains fewer neurons in schizophrenia. The MD is a key node in a circuit proposed to be dysfunctional in the disorder. However, one study did not find a MD volume loss in schizophrenia, and all the studies to date are relatively small. Given the importance of establishing unequivocally the presence of MD pathology, we have carried out a study of the volume and number of neurons in the left and right MD in 21 patients with schizophrenia and 27 healthy comparison subjects. We also measured the size of MD neurons, and estimated total thalamic volume. We found no difference in the volume of the MD, the number of MD neurons, or the size of MD neurons in either hemisphere in schizophrenia. Neither was total thalamic volume altered. There are no obvious methodological or clinical factors to explain our failure to replicate the finding of MD involvement in schizophrenia. Hence our negative observations, in the largest sample yet investigated, cast doubt on the robustness and/or the generalisability of MD neuropathology in schizophrenia.

Larval debridement therapy: a cost-effective alternative to hydrogel in necrotic venous ulcers: a randomized trial

Background

Evidence for the effectiveness of larval debridement therapy (LDT) in necrotic wounds has hitherto been the anecdotal results of enthusiasts. The aim of this study was to compare the cost and effectiveness of LDT with standard hydrogel treatment of necrotic venous ulcers.

Methods

Patients with sloughy venous ulcers were randomized to either standard hydrogel dressings (Intrasite gel) (group 1) or LDT (group 2). All patients were reviewed every 72 h until effective debridement had occurred, for a maximum of 1 month. The outcome measure used for effectiveness was whether or not desloughing occurred and time to deslough. The measures of cost were the cost of nursing time, dressing costs, and costs of larvae and hydrogel required to achieve healing in 1 month's treatment.

Results

Twelve patients were randomized. Ulcers in all patients receiving LDT (group 2) desloughed within two applications of larva therapy. All of these patients were treated subsequently with four-layer bandaging and all healed within 4 months. Ulcers in only two patients in group 1 desloughed completely within 1 month. One of the patients in whom hydrogel had failed at 1 month was changed to LDT and the ulcer desloughed with one application. Taking into account the cost of a vial of larvae (£58), the overall median cost of treatment in group 1 was greater than that in group 2 (£136·23 (range 63·89–319·30) versus £78·64 (range 73·49–£92·36)).

Conclusion

LDT is more effective and significantly less expensive than hydrogel in the debridement of sloughy venous ulcers. While a larger randomized controlled study should be performed to confirm these observations, LDT appears to be a cost-effective alternative to hydrogel.

Automatically Training a Problematic Dialogue Predictor for a Spoken Dialogue System

Spoken dialogue systems promise efficient and natural access to a large variety of information sources and services from any phone. However, current spoken dialogue systems are deficient in their strategies for preventing, identifying and repairing problems that arise in the conversation. This paper reports results on automatically training a Problematic Dialogue Predictor to predict problematic human-computer dialogues using a corpus of 4692 dialogues collected with the 'How May I Help You' (SM) spoken dialogue system. The Problematic Dialogue Predictor can be immediately applied to the system's decision of whether to transfer the call to a human customer care agent, or be used as a cue to the system's dialogue manager to modify its behavior to repair problems, and even perhaps, to prevent them. We show that a Problematic Dialogue Predictor using automatically-obtainable features from the first two exchanges in the dialogue can predict problematic dialogues 13.2% more accurately than the baseline.

Ecological and genetic aspects of grape phylloxera Daktulosphaira vitifoliae (Hemiptera: Phylloxeridae) performance on rootstock hosts

Performance and genetic variability of clonal lineages derived from one Californian and one German population of grape phylloxera, Daktulosphaira vitifoliae Fitch were studied on their natal grape rootstock host and on three novel hosts over four generations in an aseptic dual culture system. The ability of D. vitifoliae to adapt to new hosts was measured by changes in fitness (rm) over four generations. The performance of a given clonal lineage changed over successive generations, depending upon the host plant and the phylloxera group. Analysis of amplified fragment length polymorphism-polymerase chain reaction (AFLP-PCR) banding patterns from 40 individual parthenogenetic D. vitifoliae revealed equal levels of genetic variation both among the four clonal lineages analysed and within the different generations of one lineage. Analysis of molecular variance (AMOVA) showed no significant differences between the D. vitifoliae lineages reared on different host plants, nor was a correlation between host performance and genotype found.

A Technique for Screening Grape Germplasm for Resistance to Meloidogyne incognita

A technique to evaluate the root-knot nematode resistance of grape seedlings was developed. Seedlings of rootstock crosses and nematode-susceptible Vitis vinifera cvs. Colombard and Carignane were inoculated with Meloidogyne incognita juveniles. Reproduction of nematodes on individual plants was measured by counting the number of egg masses stained with eosin and the number of eggs present. Egg mass counts were highly correlated with egg counts. Resistant and susceptible cultivars could be clearly distinguished by the number of egg masses produced on vegetatively propagated cuttings. It is concluded that egg mass counting can substitute for the more laborious and time-consuming methods of counting nematode eggs or juveniles in the evaluation of root-knot nematode resistance in Vitis.

Synthesis of a novel C-10 spiro-epoxide of paclitaxel

New analogues of paclitaxel (1a, active constituent of Taxol) were synthesized containing an epoxide at the C-10 position. The introduction of the epoxide was carried out by selective removal of the C10-acetate followed by protection of the C2'- and C7-hydroxyl groups. After oxidation to yield a ketone at the C10-position, this intermediate was reacted with dimethylsulfonium ylide. Deprotection and further manipulations provide the C10-spiro epoxide of paclitaxel (1b) and the corresponding C7-MOM ether (1c).

Simple sequence repeat analysis of a clonally propagated species: a tool for managing a grape germplasm collection

The USDA germplasm repositories help to preserve the genetic variability of important crop species by collecting and maintaining representative cultivars and related germplasm. Simple sequence repeat markers with high allelic diversity were used to type 41 grapevines from 40 accessions. All vines were either seedless table grape cultivars or cultivars with names similar to table grape cultivars. The proportion of shared alleles was selected as the most appropriate statistical measure of genetic distance for this population. In conjunction with morphological traits, known synonyms were confirmed and a previously unknown synonym was discovered. An alleged synonym in the literature was disproved by the DNA data. The data were consistent with known parentage, where such data were available. Two mislabeled vines in the USDA collection were identified. UPGMA grouped the cultivars loosely into three groups: a group of nine mostly Middle Eastern cultivars, a group of 22 accessions mostly from Russia and Afghanistan that were morphologically similar to 'Thompson Seedless', and a third very loose group of 11 accessions consisting mostly of eastern European wine grape cultivars. The limitations and usefulness of this type of analysis are discussed.

Schizophrenia and the frontal lobes: post-mortem stereological study of tissue volume

BACKGROUND

It has been suggested that there is frontal lobe involvement in schizophrenia, and that it may be lateralised and gender-specific.

AIMS

To clarify the structure of the frontal lobes in schizophrenia in a post-mortem series.

METHOD

The volume of white matter and cortical components of the frontal lobes was measured in brains of controls and patients with schizophrenia using planimetry and the Cavalieri principle. The components measured were: superior frontal gyrus, middle frontal gyrus, a composite of inferior frontal gyrus and orbito-frontal cortex, as well as total frontal lobe cortex and white matter. In addition, the anterior cingulate gyrus was measured.

RESULTS

No diagnosis, gender, diagnosis x side, diagnosis x gender or diagnosis x gender x side interactions were observed in the volume of any of the components, the grey matter as a whole or the white matter. No evidence for volumetric inter-group differences was found for the anterior cingulate gyrus.

CONCLUSIONS

Such structural abnormalities as are present in the frontal lobes are more subtle than straightforward alterations in tissue volume; they may include changes in shape and the pattern of gyral folding.

Seasonal capacity of attached and detached vineyard roots to support grape phylloxera (Homoptera: Phylloxeridae)

Field experiments were conducted to evaluate population densities and survival, developmental rate, and fecundity of grape phylloxera, Daktulosphaira vitifoliae (Fitch), as influenced by root attachment or detachment from mature, field-grown, Vitis vinifera L. grapevines through the growing season. Experiments were performed using artificial infestations of California biotype A grape phylloxera. Thirty-day bioassays on attached- and detached-roots were repeated monthly from May to September in 1997 (cultivar 'Carignane') and April to September in 1998 (cultivar 'Thompson Seedless'). The bioassays showed that attached roots had lower population densities than detached roots in all months of both years. Densities varied by month, tending to be higher in spring than in summer. Of the population parameters studied, survival was most influenced by attachment condition, being higher on detached than on attached roots by up to 25-fold. These results imply the importance of vine-related mortality factors to grape phylloxera population density. Influence of root attachment condition on developmental rate and fecundity was not uniform across bioassay months for either year; however, in the four out of 21 assays where there was a significant difference it favored detached roots by twofold. Fruit harvest resulted in higher survival in the July assay but not for assays in August and September; however, neither developmental rate nor fecundity was affected by harvest in any ofthe assays. We conclude that mortality rather than nutritional factors are most limiting for field populations on susceptible vines. This work suggests that detachment of roots as occurs with root girdling by root pathogens may increase grape phylloxera populations on infested, susceptible vines. These results imply that excised root bioassays over-estimate grape phylloxera virulence and underestimate rootstock resistance.

Biology and management of grape phylloxera

Grape phylloxera, Daktulosphaira vitifoliae (Homoptera: Phylloxeridae), is a worldwide pest of grapevines. Its life cycle has sexual and asexual portions with forms that feed from leaf and root galls. Not all forms occur throughout the insect's range. Root forms predominate on Vitis vinifera cultivars; leaf forms predominate on other Vitis species characteristic of the American native range. Other conditions influence expression of the life cycle. Hosts and conditions similarly affect life table performance. Damage to grapevines is by secondary soilborne pathogens attacking the feeding site and by physiological interaction of the insect with the grapevine, though the latter has not been well studied. Resistant rootstocks derived from native American Vitis are the primary control tool. The insect varies genetically and relative to performance on hosts. Use of insecticides is limited in effect, and other control methods are not proven. More research on the biology, ecology, and management of phylloxera is needed.

A two-component pericyclic reaction for synthesis of substituted benzofurans and aryl-quaternary carbon bonds

The reaction shown is presumed to be a new [3,3]-sigmatropic rearrangement involving an O-arylsulfoxonium species or related sulfurane. It allows a sulfoxide and a phenol to be joined and rearranged in one operation at or below room temperature, coupling an aromatic to a quaternary carbon and creating benzofurans or articulated dihydrobenzofurans in a number of examples.

Genetic structure of an introduced pest, grape phylloxera (Daktulosphaira vitifoliae Fitch), in Europe

A model for the genetic structure of grape phylloxera populations in Europe was developed using hierarchical sampling techniques and AFLP-PCR (amplified fragment length polymorphism--polymerase chain reaction) methodology. One-hundred three European and 6 North American phylloxera populations were studied. An additional European sampling set comprising 60 samples was analyzed to study regional subdivision. The populations grouped into two clusters loosely correlated with collection site location. Phylloxera populations collected from northern (above lat 43 degrees) geographic regions were significantly different from southern (below 43 degrees) populations. The northern cluster was more heterogeneous than the southern cluster, possibly reflecting holocyclic versus anholocyclic reproduction. Microgeographic scales of phylloxera genetic structure displayed as much variation within as among host plants. The host plant did not affect the genetic structure of European phylloxera as revealed in two independent experiments.

The cost effectiveness of larval therapy in venous ulcers

The treatment of necrotic ulcers involves considerable nursing time and expense. The current standard treatment involves repeated application of hydrogels. Larval debridement therapy (LDT) has been shown anecdotally to clear ulcers of necrotic slough but has never been compared directly with 'modern' therapies. The aim of this study has been to compare LDT with hydrogel dressings in the treatment of necrotic venous ulcers. 12 patients with sloughy venous ulcers were randomised to receive either LDT or the control therapy--a hydrogel. Effective debridement occurred with a maximum of one larval application in 6/6 patients. 4/6 patients [corrected] in the hydrogel group still required dressings at one month. The median cost of treatment of the larval group was 78.64 Pounds compared with 136.23 Pounds for the control treatment group (p < 0.05). The study confirms both the clinical efficacy and cost effectiveness of larval therapy in the debridement of sloughy venous ulcers.

An Application of Reinforcement Learning to Dialogue Strategy Selection in a Spoken Dialogue System for Email

This paper describes a novel method by which a spoken dialogue system can learn to choose an optimal dialogue strategy from its experience interacting with human users. The method is based on a combination of reinforcement learning and performance modeling of spoken dialogue systems. The reinforcement learning component applies Q-learning (Watkins, 1989), while the performance modeling component applies the PARADISE evaluation framework (Walker et al., 1997) to learn the performance function (reward) used in reinforcement learning. We illustrate the method with a spoken dialogue system named ELVIS (EmaiL Voice Interactive System), that supports access to email over the phone. We conduct a set of experiments for training an optimal dialogue strategy on a corpus of 219 dialogues in which human users interact with ELVIS over the phone. We then test that strategy on a corpus of 18 dialogues. We show that ELVIS can learn to optimize its strategy selection for agent initiative, for reading messages, and for summarizing email folders.

A null mutation in HLA-G is not associated with preeclampsia or intrauterine growth retardation

Modulation of the expression of genes of the major histocompatibility complex (MHC) in tissues at the maternal-fetal interface almost certainly plays a role in successful development of the semi-allogeneic fetus. While expression of the classical class I genes (HLA-A, B, C) is low to non-existent at this site, the non-classical molecule, HLA-G, is expressed uniquely in fetal cells at the maternal-fetal interface. The recent demonstration that homozygotes for a deletion mutation in exon 3 (1597DeltaC) of HLA-G do not express the full-length HLA-G1 isoforms indicates a potential reduction in expression of this isoform in heterozygotes. If the full-length isoform of HLA-G (i.e. HLA-G1) contributes to proper invasion of maternal spiral arteries by extravillous cytotrophoblast, then 1597DeltaC heterozygotes could be at increased risk for disorders of trophoblast invasion. Two populations, infants with intrauterine growth retardation (IUGR) and infants of preeclamptic (PE) mothers, were genotyped for the 1597DeltaC polymorphism. The frequency of 1597DeltaC in these samples was not significantly different from healthy controls, suggesting that heterozygotes for this deletion mutation are not at significantly increased risk for PE or IUGR (P = 0.727 and 0.803, respectively).

Comparison of nuclear scintigraphy and acetaminophen absorption as a means of studying gastric emptying in horses

OBJECTIVE

To evaluate the correlation between halftime of liquid-phase gastric emptying (T50), determined with nuclear scintigraphy using technetium Tc 99m pentetate, and absorption variables of orally administered acetaminophen.

ANIMALS

6 mature horses.

PROCEDURE

Technetium Tc 99m pentetate (10 mCi) and acetaminophen (20 mg/kg of body weight) were administered simultaneously in 200 ml of water. Serial left and right lateral images of the stomach region were obtained with a gamma camera, and T50 determined separately for counts obtained from the left side, the right side and the geometric mean. Power exponential curves were used for estimation of T50 and modified R2 values for estimation of goodness of fit of the data. Serial serum samples were taken, and acetaminophen concentration was determined, using fluorescence polarization immunoassay. Maximum serum concentration (Cmax), time to reach maximum serum concentration (Tmax), area under the curve for 240 minutes and the absorption constant (Ka) were determined, using a parameter estimation program. Correlations were calculated, using the Spearman rank correlation coefficient.

RESULTS

Correlations between T50 and Tmax and between T50 and Ka were significant.

CONCLUSIONS AND CLINICAL RELEVANCE

Tmax and Ka are valuable variables in the assessment of liquid-phase gastric emptying using acetaminophen absorption. Acetaminophen absorption may be a valuable alternative to nuclear scintigraphy in the determination of gastric emptying rates in equine patients with normally functioning small intestine.

Anomalous asymmetry of fusiform and parahippocampal gyrus gray matter in schizophrenia: A postmortem study

OBJECTIVE

Anomalies of structure and asymmetry of the parahippocampal gyrus (origin of the perforant path input to the hippocampal formation in the medial temporal lobe) have been shown in some postmortem studies of schizophrenia, but previous studies have not included the fusiform gyrus (which may have a role in facial recognition and naming), adjacent to the parahippocampal gyrus on the ventral occipitotemporal surface.

METHOD

The volumes of gray matter in the left and right parahippocampal and fusiform gyri were assessed with a stereological point-counting technique in the temporal lobes from formalin-fixed brains of 27 comparison subjects and 31 patients with schizophrenia. Age was a covariate and gender was a factor in the analysis.

RESULTS

In relation to the comparison subjects, the schizophrenic patients (both sexes) had lower volumes of both the parahippocampal and fusiform gyri on the left side. For both structures a left-greater-than-right volume asymmetry was present in the comparison subjects, but this asymmetry was reversed in the parahippocampal and fusiform gyri of the schizophrenic patients. A sex difference was present with respect to age at onset-degree of anomaly of asymmetry for both gyri increased with age at onset in men but not in women.

CONCLUSIONS

The findings add substance to the view that the sex-related dimension of symmetry/asymmetry is integral to the disease process in schizophrenia and draw attention to the fusiform gyrus as a structure of particular interest in relation to disturbances of identification and naming in psychosis.

Contrast radiographic findings in canine bacterial discospondylitis: a multicenter, retrospective study of 27 cases

A multicenter, retrospective study was undertaken to evaluate contrast radiographic findings in canine bacterial discospondylitis. Records and myelograms or epidurograms of 27 patients were obtained from five colleges of veterinary medicine. Fifteen cases (56%) were evaluated as having some degree of spinal cord compression. The majority (73.3%) of the cases had only soft tissue as the compressive mass. The median compression for all cases was 5% of the vertebral canal. No difference was noted for compression based on anatomical site (i.e., cervical versus thoracolumbar versus lumbosacral). No significant correlation between degree of lesion compression and clinical outcome was noted, but there was a trend toward increased mortality with greater compression. There was no correlation between the ambulatory status and the ultimate outcome. Three of the 15 (20%) cases showed vertebral subluxation. Results of this study indicate that static spinal cord compression is not a significant component of the neurological dysfunction associated with bacterial discospondylitis. Identification of vertebral subluxation in some patients may indicate a dynamic lesion that should be evaluated with stress radiography.