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Background Cardiovascular and metabolic diseases are prevalent among patients with chronic liver disease (CLD) and contribute to adverse outcomes and mortality. Prior studies have hypothesized statin therapy improves liver transplant (LT) survival due to anti-inflammatory properties and reduced cardiac risk. Evidence for use of statins in this population is limited as acute liver failure or decompensated cirrhosis is considered a contraindication. Despite evidence supporting statin therapy in CLD their use remains inconsistent. Purpose Our study aimed to evaluate the indication and rate of statin use in patients both pre- and post-LT, as well as the impact on post-LT patient survival, graft failure, and post-LT cardiovascular and metabolic disease. Method This was a retrospective cohort study of adult LT recipients at the University of Alberta, Edmonton, Canada between 2005 and 2020. Exclusion criteria included pre-transplant acute liver failure, multi-visceral transplant, and re-transplant. Demographic, pharmaceutical and clinical data was collected through review of electronic medical records. Primary endpoints included rate of statin use, post-LT patient survival, and graft failure; secondary endpoints included development of cardiac disease, dyslipidemia, and metabolic syndrome post-LT. Result(s) We identified 868 patients meeting inclusion criteria; 596 (68.7%) were male, 713 (82.3%) were Caucasian, and median age at transplant was 55. The most common indication for LT was hepatocellular carcinoma in 291 patients (33.5%), followed by Hepatitis C Virus (24.0%), and alcohol liver disease (16.9%). There were no significant demographic differences between those who were and were not on statin therapy. In the pre-LT period only 3% of patients were on statins, despite 7% of patients having dyslipidemia and 24% having diabetes. A total of 261 patients (29.9%) were placed on statins post-LT. The use of statins post-LT was associated with decreased mortality (OR 0.433, 95% CI [0.302-0.622], p Conclusion(s) In our study we identified an association between statin use in the post-LT setting and improved mortality and graft survival. We did not find an association with improved cardiac or metabolic outcomes. The negative association between statin use and post-LT rejection may reflect detection bias as patients with rejection are closely monitored. We also identified a discrepancy between the number of patients with indication for statin use and those who were on statins both pre and post LT, reflecting underutilization consistent with prior literature. Additional studies are required to elucidate the role of statin medications in the transplant hepatologists armamentarium. Please acknowledge all funding agencies by checking the applicable boxes below None Disclosure of Interest None Declared

Cooler growing conditions in subtropical environments adversely affect banana fruit yield and quality. Crop cycling is longer, plants and fruits can be damaged by low temperatures, and bunches and fruits develop abnormally. These cooler temperatures also predispose some cultivars to pest and disease susceptibility. There is also consumer purchasing resistance to the dull gray/yellow fruit exhibiting under-peel discoloration caused by chilling. A simple prototype sap flow test shows promise as a practical, objective measure of cold tolerance to support the standard evaluation measures, chlorophyll photo-oxidation, black spotting of leaves, petiole blackening and vigour ratings. Sap flow tests were conducted between July and November 2016 at the Duranbah cultivar trial site in New South Wales, Australia. In this study, the top hand from the bunch was removed from the peduncle immediately after harvest, and the number of drops of sap in the first minute from the cut surface of the hand was measured. None of the ten Cavendish types (AAA) tested exhibited any sap flow during winter, and only two had sap flow in mid-November, well into the Australian spring. All four tetraploid cultivars, two AAB cultivars and one ABB cultivar tested showed sap flow right through the winter months. Significant differences in sap flow were found between some of the cultivars. Cold tolerance is a major selection criterion for potential new cultivars for the Australian subtropics, and this simple sap flow test shows promise as a practical, objective measure of cold tolerance to complement the standard evaluation measures. © 2020 International Society for Horticultural Science. All rights reserved.

A challenge preventing successful inverse kinematics measurements with heavy nuclei that are not fully stripped is identifying and tagging the beam particles. For this purpose, the HEavy ISotope Tagger (HEIST) has been developed. HEIST utilizes two micro-channel plate timing detectors to measure time of flight, a multi-sampling ion chamber to measure energy loss, and a high purity Ge detector to identify isomer decays and calibrate the isotope identification system. HEIST has successfully identified $^{198}$Pb and other nearby nuclei at energies of about 75 MeV/A. In the experiment discussed, a typical cut containing 89\% of all $^{198}$Pb$^{+80}$ in the beam had a purity of 86\%. We examine the issues of charge state contamination. The observed charge state populations of these ions are presented and are moderately well described by the charge state model GLOBAL., Comment: The following article has been submitted to Review of Scientific Instruments

Even though hematopoietic stem cells (HSC) are characterized by their ability to self-renew and differentiate, they primarily reside in quiescence. Despite the immense importance of this quiescent state, its maintenance and regulation is still incompletely understood. Schlafen2 (Slfn2) is a cytoplasmic protein known to be involved in cell proliferation, differentiation, quiescence, interferon response, and regulation of the immune system. Interestingly, Slfn2 is highly expressed in primitive hematopoietic cells. In order to investigate the role of Slfn2 in the regulation of HSC we have studied HSC function in the elektra mouse model, where the elektra allele of the Slfn2 gene contains a point mutation causing loss of function of the Slfn2 protein. We found that homozygosity for the elektra allele caused a decrease of primitive hematopoietic compartments in murine bone marrow. We further found that transplantation of elektra bone marrow and purified HSC resulted in a significantly reduced regenerative capacity of HSC in competitive transplantation settings. Importantly, we found that a significantly higher fraction of elektra HSC (as compared to wild-type HSC) were actively cycling, suggesting that the mutation in Slfn2 increases HSC proliferation. This additionally caused an increased amount of apoptotic stem and progenitor cells. Taken together, our findings demonstrate that dysregulation of Slfn2 results in a functional deficiency of primitive hematopoietic cells, which is particularly reflected by a drastically impaired ability to reconstitute the hematopoietic system following transplantation and an increase in HSC proliferation. This study thus identifies Slfn2 as a novel and critical regulator of adult HSC and HSC quiescence.

Background The COVID-19 pandemic has brought significant challenges to clinicians caring for liver transplant (LT) recipients. Researchers have sought to better understand the risk and clinical outcomes of LT recipients infected with COVID-19 globally, however, there is a paucity of data from within Canada. Aims Our multi-center study aims to examine the characteristics and clinical outcomes of LT patients with COVID-19 in Canada. Methods We identified a retrospective cohort of adult LT recipients with RT-PCR confirmed COVID-19 from 7 Canadian tertiary care centers between March 2020 and June 2021. Demographic and clinical data were compiled by clinicians within those centers. We identified liver enzyme profile at the time of COVID-19 infection, immunosuppression type and post-infection adjustments, rate of hospitalization, ICU admission, mechanical ventilation, and death. Results A total of 49 patients with a history of LT and COVID-19 infection were identified. Twenty nine patients (59%) were male, the median time from LT was 66 months (1, 128) and the median age at COVID-19 infection was 59 years (52, 65). At COVID-19 diagnosis, the median ALT was 37 U/L (21, 41), AST U/L was 34 (20, 37), ALP U/L was 156 (88, 156), Total Bilirubin was 11 umol/L (7, 14), and INR was 1.1 (1.0, 1.1). The majority of patients (92%) were on tacrolimus monotherapy or a combination of tacrolimus and mycophenolate mofetil (MMF); median tacrolimus level at COVID-19 diagnosis was 5.3 ug/L (4.0, 8.1). Immunosuppression was modified in 8 (16%) patients post-infection; either the tacrolimus dose was reduced or MMF was held. One patient developed acute cellular rejection which recovered after re-initiation of the prior regimen. Eighteen patients (37%) required hospitalization, 6 (12%) were treated with dexamethasone, and 3 (6%) required ICU admission and mechanical ventilation. Four patients (8%) died due to complications of COVID-19. On univariate analysis, neither age, sex, co-morbidities nor duration post-transplant were associated with risk of hospitalization. Conclusions In our national retrospective study, approximately 40% of patients required hospitalization with a mortality rate of < 10%. Previous studies have shown proximity to LT as an independent factor for mortality with COVID-19; the median time from LT for our patients was 5 years, which may explain the lower mortality rate. Of note, the median tacrolimus levels were much lower in comparison to the target of 8–10 ug/L used in the first year post-transplant. As the landscape of COVID-19 changes with vaccination, evolving treatments, and increasing rates of variant transmission, additional studies are required to continue identifying trends in clinical outcomes. Funding Agencies None

Three Gros Michel mutants (‘IBP 5-B’, ‘IBP 5–61’ and ‘IBP 12’) from the Cuban Instituto de Biotecnologia de las Plantas, two semi-dwarf Gros Michel varieties (‘Highgate’ and ‘Cocos’) and a Thai accession (‘Hom Thong Mokho’) were evaluated in Australia over a five year period. They were screened for their resistance to Fusarium wilt Race 1 (FocR1) caused by the pathogen Fusarium oxysporum f.sp. cubense, as well as resistance to yellow Sigatoka (Pseudocercospora musae Zimm [teleomorph Mycosphaerella musicola Leach]). They were also grown for a plant and ratoon crop in the tropics (17°S) and a plant crop in the subtropics (28°S) with no disease pressure to record their agronomic characteristics. They were compared with Australian industry standards, ‘Williams’ (AAA, Cavendish subgroup) and ‘Lady Finger’ (AAB, Pome subgroup). In the subtropics the Gros Michel mutants and semi-dwarf accessions were sensitive to cold and very susceptible to FocR1 and yellow Sigatoka while their agronomic performance in the tropics was good, with ‘Highgate’ having the best bunch weight on a shorter, more manageable plant. Of the six accessions evaluated, ‘Hom Thong Mokho’ showed the highest level of resistance to FocR1 although it had poor cold tolerance, as did the other Gros Michel selections, and consequently had low productivity compared to ‘Williams’ and even ‘Lady Finger’. However in the warmer, more humid tropics ‘Hom Thong Mokho's performance was much better and it was less susceptible to yellow Sigatoka than the other Gros Michel selections. Subsequent genetic analysis by Christelova et al. (2011) has revealed that although ‘Hom Thong Mokho’ is marketed as a Gros Michel variety in Asia, it is closer to the Rio subgroup (AAA) of dessert bananas.

Mixing matrices quantify how people with similar or different characteristics make contact with each other, creating potential for disease transmission. Little empirical data on mixing patterns among persons who inject drugs (PWID) are available to inform models of blood-borne disease such as HIV and hepatitis C virus. Egocentric drug network data provided by PWID in Baltimore, Maryland between 2005 and 2007 were used to characterise drug equipment-sharing patterns according to age, race and gender. Black PWID and PWID who were single (i.e. no stable sexual partner) self-reported larger equipment-sharing networks than their white and non-single counterparts. We also found evidence of assortative mixing according to age, gender and race, though to a slightly lesser degree in the case of gender. Highly assortative mixing according to race and gender highlights the existence of demographically isolated clusters, for whom generalised treatment interventions may have limited benefits unless targeted directly. These findings provide novel insights into mixing patterns of PWID for which little empirical data are available. The age-specific assortativity we observed is also significant in light of its role as a key driver of transmission for other pathogens such as influenza and tuberculosis.

An effective method has been developed for the stable transformation and regeneration of Cavendish banana (Musa spp. AAA group) cv 'Grand Nain' by microprojectile bombardment. Embryogenic cell suspensions were initiated using immature male flowers as the explant. Cells were co-bombarded with the neomycin phosphotransferase (nptII) selectable marker gene under the control of a banana bunchy top virus (BBTV) promoter or the CaMV 35S promoter, and either the β-glucuronidase (uidA) reporter gene or BBTV genes under the control of the maize polyubiquitin promoter. Plants were regenerated, under selection with kanamycin, that were co-transformed with nptII and either the uidA or BBTV genes. Molecular characterisation of transformants demonstrated that the transgenes had been stably integrated into the banana genome.

Apart from morphology and genetic characteristics, species status of Pythium zingiberis and P. myriotylum may also be confirmed based on their pathogenicity and host range. An Australian putative P. zingiberis isolate and imported type isolates of P. myriotylum and P. zingiberis were subject to both in vitro and in vivo pathogenicity tests. In vitro tests were carried out on excised carrot, ginger, potato, radish, and sweet potato tuber/root sections, and on seeds and seedlings of cucumber, cauliflower, millet, rye, sweet corn, tomato, and wheat. In all assays conducted, the Australian isolate was found to be the most pathogenic, followed by type specimen of P. zingiberis (UOP 275), and then the type specimen P. myriotylum (CBS 254.70). An in vivo experiment on ginger plants at 35°C (with 10 h day light) in quarantine conditions showed that the ginger plants inoculated with the Australian isolate and also the type specimen of P. zingiberis died at 21 days after inoculation, whereas those inoculated with P. myriotylum CBS 254.70 were still green and healthy. Along with cardinal growth rate, the Australian isolate was confirmed to be closely related to P. zingiberis. This is also the first direct comparison in pathogenicity of P. zingiberis and P. myriotylum.

Six tetraploid hybrids from Fundacion Hondurena de Investigacion Agricola (FHIA) were evaluated in Australia over a five year period. They included three AAAA hybrids (FHIA-02, FHIA-17 and FHIA-23) and three AAAB hybrids (FHIA-01, FHIA-18 and SH-3640.10) and they were compared with industry standards, ‘Williams’ (AAA, Cavendish subgroup) and ‘Lady Finger’ (AAB, Pome subgroup). They were screened for their resistance to Fusarium wilt race 1 and subtropical race 4 caused by the pathogen Fusarium oxysporum f.sp. cubense and they were also grown for several cycles on farms not infested with Fusarium wilt to record their agronomic characteristics. The AAAB hybrids, all derived from female parent ‘Prata Ana’ (AAB, Pome subgroup) were the most resistant to both races of Fusarium wilt and were very productive in the subtropics. They were significantly more productive than ‘Lady Finger’, which was susceptible to both races of Fusarium wilt. The AAAA hybrids, with the exception of FHIA-02 which was very susceptible to Fusarium wilt and displayed the poorest agronomic traits of the six hybrids, produced bunch weights as good as Cavendish but were significantly slower to cycle. FHIA-17 and FHIA-23, both derived from the female parent ‘Highgate’ (AAA, Gros Michel subgroup), were also significantly more resistant to Fusarium wilt than ‘Gros Michel’, while FHIA-17 demonstrated a level of resistance similar to ‘Williams’ and FHIA-23 was intermediate between ‘Lady Finger’ and ‘Williams’.

TRFLP (terminal restriction fragment length polymorphism) was used to assess whether management practices that improved disease suppression and/or yield in a 4-year ginger field trial were related to changes in soil microbial community structure. Bacterial and fungal community profiles were defined by presence and abundance of terminal restriction fragments (TRFs), where each TRF represents one or more species. Results indicated inclusion of an organic amendment and minimum tillage increased the relative diversity of dominant fungal populations in a system dependant way. Inclusion of an organic amendment increased bacterial species richness in the pasture treatment. Redundancy analysis showed shifts in microbial community structure associated with different management practices and treatments grouped according to TRF abundance in relation to yield and disease incidence. ANOVA also indicated the abundance of certain TRFs was significantly affected by farming system management practices, and a number of these TRFs were also correlated with yield or disease suppression. Further analyses are required to determine whether identified TRFs can be used as general or soil-type specific bio-indicators of productivity (increased and decreased) and Pythium myriotylum suppressiveness.

To examine the HIV/sexually transmitted infection (STI)-related risk behaviours among community-based female sex workers (FSWs) and their clients in Yunnan Province, China, we performed a cross-sectional study of 705 FSWs and 100 male clients. We found that HIV seroprevalence among FSWs was 13.0% and the most prevalent STI was herpes simplex virus type 2 (HSV-2) (71.1%), followed by Chlamydia trachomatis (18.1%) and syphilis (8.8%). The 20% of FSWs who reported injection drug use also reported needle-sharing behaviours in the last three months. Drug-using FSWs had substantially higher HIV and HSV-2 prevalence, serviced more clients and had a longer history of sex work than non-using FSWs. In total, 57.0% of male clients did not consistently use condoms with FSWs, 2.0% reported illicit drug use and 17.0% had STI symptoms in the last year. The dual risk behaviours of drug-using FSWs and clients place them at greater risk of HIV infection. Intervention programmes must adopt comprehensive methods.

Large-volume CdZnTe (CZT) single crystals with electron lifetimes exceeding 10 μs recently became available commercially for making large effective area gamma-ray arrays. However, significant variations were observed in the performance of detectors made from such arrays. We evaluated the spectroscopic performance of such a large-volume, 20 × 20 × 15 mm3, coplanar-grid (CPG) CdZnTe detector, intended for use in a handheld radioisotope-identifier, which unexpectedly showed a poor spectral performance with an energy resolution of 3.5-4% FWHM measured with 662-keV gamma-rays. To understand the factors affecting its performance, we applied several characterization techniques, viz., white X-ray diffraction topography measurements, IR microscopy, and micron-spatial resolution X-ray mapping. They allowed us to identify major crystal defects in the device that limit its energy resolution and detection efficiency.

A field experiment was established in which an amendment of poultry manure and sawdust (200 t/ha) was incorporated into some plots but not others and then a permanent pasture or a sequence of biomass-producing crops was grown with and without tillage, with all biomass being returned to the soil. After 4 years, soil C levels were highest in amended plots, particularly those that had been cropped using minimum tillage, and lowest in non-amended and fallowed plots, regardless of how they had been tilled. When ginger was planted, symphylans caused severe damage to all treatments, indicating that cropping, tillage and organic matter management practices commonly used to improve soil health are not necessarily effective for all crops or soils. During the rotational phase of the experiment, the development of suppressiveness to three key pathogens of ginger was monitored using bioassays. Results for root-knot nematode (Meloidogyne javanica) indicated that for the first 2 years, amended soil was more suppressive than non-amended soil from the same cropping and tillage treatment, whereas under pasture, the amendment only enhanced suppressiveness in the first year. Suppressiveness was generally associated with higher C levels and enhanced biological activity (as measured by the rate of fluorescein diacetate (FDA) hydrolysis and numbers of free-living nematodes). Reduced tillage also enhanced suppressiveness, as gall ratings and egg counts in the second and third years were usually significantly lower in cropped soils under minimum rather than conventional tillage. Additionally, soil that was not disturbed during the process of setting up bioassays was more suppressive than soil which had been gently mixed by hand. Results of bioassays with Fusarium oxysporum f. sp. zingiberi were too inconsistent to draw firm conclusions, but the severity of fusarium yellows was generally higher in fumigated fallow soil than in other treatments, with soil management practices having little impact on disease severity. With regard to Pythium myriotylum, biological factors capable of reducing rhizome rot were present, but were not effective enough to suppress the disease under environmental conditions that were ideal for disease development.

Tropical fruits play an important role in the economy of Queensland. The major crops are banana, mango, pineapple and papaya. For the past 20 years, biotechnology has been applied to tropical fruit species in Queensland. Micropropagation systems have been developed for banana, pineapple, papaya, passionfruit and coffee; and good embryogenic protocols have been employed in banana, mango and papaya. A program of intergeneric hybridisation between papaya and related Vasconcella species has continued since 1991 and has been facilitated by embryo rescue and plantlet production, and micropropagation in vitro. Cryopreservation protocols are being developed for several tropical fruit species. Transformation systems have been used to produce disease resistant genotypes of papaya and to prevent blackheart, to control flowering and delay ripening of pineapple. Molecular marker technology has been used for genotype identification and to confirm intergeneric hybrids between papaya and related Vasconcella species. Molecular maps have been developed for two Vasconcella species. Genetic diversity within mangosteen populations and between related wild species has been evaluated with RAF markers. Specific DAF markers have been identified for sex determination in papaya, and SCAR markers have been developed to identify dwarfism in bananas and the PRSV-P resistant gene in Vasconcella cundinamarcensis.

'Goldfinger', a tetraploid banana produced from the Fundacion Hondurena de Investigacion Agricola (FHIA) breeding program, was released to the Australian industry in 1995. It was promoted as an apple-flavoured dessert banana with resistance to Fusarium wilt race 1 and subtropical race 4, as well as resistance to black and yellow Sigatoka (Mycosphaerella fijiensis and M. musicola, respectively). This study was initiated to provide agronomic information to the banana industry, which was under threat from Fusarium wilt, on a new cultivar which could replace 'Williams' (AAA, Cavendish subgroup) or 'Lady Finger' (AAB, Pome subgroup) in those areas affected by Fusarium wilt. Also few studies had reported on the production characteristics of the new tetraploid hybrids, especially from subtropical areas, and therefore two field sites, one a steep-land farm and the other a level, more productive site, were selected for planting density and spatial arrangement treatments. The optimum density in terms of commercial production, taking into account bunch weight, finger size, length of the production cycle, plant height and ease of management, was 1680 plants/ha on the steep-land site where plants were planted in single rows with 2.5 m × 2.5 m spacings. However on the level site a double-row triangular layout with inter-row distances of 4.5 m to allow vehicular access (1724 plants/ha) gave the best results. With this arrangement plants were in an alternate, triangular arrangement along a row and a spacing of 1.5 m between plants at the points of each triangle and between each block of triangles.

The population genetic structure of the freshwater snail, Biomphalaria glabrata, was assessed in the municipality of Virgem das Gracas (Minas Gerais, Brazil), a schistosomiasis-endemic area. The seven microsatellite loci that were used to genotype 326 individuals from 17 collection sites within a 3-km radius revealed high genetic variability. However, we found a deficit of heterozygotes relative to Hardy- Weinberg expectations for most of the loci and in many collection sites, indicating a high level of inbreeding. This may be the result of founder effects and sib-mating. A high level of overall population genetic differentiation among B. glabrata collection sites suggested low gene flow at this rela- tively small spatial scale in this region. However, subsequent analyses also indicated that these patterns may also result from founder events and that an exchange of individuals between particular collection sites does exist. The isolation-by-distance correlation between collection sites of B. glabrata was found to be significant. However, only approximately 6% of the variance in FST was explained by geographic distances suggesting that there are other factors affecting genetic differentiation among these collection sites. It is likely that the current population genetic structure reflects patterns of both migration and founder events. Results from this study are important for understanding the potential for local adaptation between schistosomes and their snail hosts at this epidemiologically relevant scale.

The effect of diurnal maximum/minimum (20/10 or 25/15 °C) temperatures on seed and fruit development of ‘Irwin’, ‘Kensington’ and ‘Nam Dok Mai’ mangoes ( Mangifera indica L.) was studied in a controlled-environment glasshouse. Exposure to low temperatures (20/10 °C day/night) 3 days after hand pollination significantly increased the percentage of stenospermocarpic fruit (nubbins), in which embryos were aborted at some stage during early fruit development. There were significant differences between cultivars in the percentage of nubbins produced out of the total fruit set following overnight exposure to 10 °C with 21% for ‘Nam Dok Mai’, 11% for ‘Kensington’ and 3% for ‘Irwin’. At 45 days after pollination, nubbin fruits were much smaller in size and weighed ca. 50% less than normal fruits. The lower percentage of nubbin fruits in ‘Irwin’ implies a greater adaptation to cool temperatures by this cultivar during fruit set and early embryo development.

The dwarf somaclonal variant is a major problem affecting micropropagation of the banana cultivar Williams (Musa spp. AAA; subgroup Cavendish). This problem arises from genetic changes that occur during the tissue culture process. Early identification of this problem is difficult and propagators must wait until plants are ex vitro in order to visualise the dwarfism phenotype. In this study, we have improved a SCAR-based molecular diagnostic technique, developed by Damasco et al. [Acta Hortic. 461 (1997) 157], for the early identification of dwarf off-types. We have included a positive internal control in a multiplex PCR and adapted the technique for use with small amounts of fresh in vitro leaf material as PCR template. The control product is a 500 bp fragment from 18S rRNA and is amplified in all tissues irrespective of phenotype. The use of small in vitro leaf material removing the need for genomic DNA extraction.

Truncated human coronavirus HCoV-229E spike glycoproteins containing amino acids 407 to 547 bound to purified, soluble virus receptor, human aminopeptidase N (hAPN). Soluble hAPN neutralized the infectivity of HCoV-229E virions at 37°C, but not 4°C. Binding of hAPN may therefore trigger conformational changes in the viral spike protein at 37°C that facilitate virus entry.

Changes in cell-surface glycan patterns are markers of the presence of many different disease and cancer types, offering a relatively untapped niche for glycan-targeting reagents and therapeutics in diagnosis and treatment. Of paramount importance for the success of any glycan-targeting reagent is the ability to specifically recognize the target among the plethora of different glycans that exist in the human body. The preeminent technique for defining specificity is glycan array screening, in which a glycan-binding protein (GBP) can be simultaneously screened against multiple glycans. Glycan array screening has provided unparalleled insight into GBP specificity, but data interpretation suffers from difficulties in identifying false-negative binding arising from altered glycan presentation, associated with the linker used to conjugate the glycan to the surface. In this work, we model the structure and dynamics of the linkers employed in the glycan arrays developed by the Consortium for Functional Glycomics. The modeling takes into account the physical presence and surface polarity of the array, and provides a structure-based rationalization of false-negative results arising from the so-called "linker effect." The results also serve as a guide for interpreting glycan array screening data in a biological context; in particular, we show that attempts to employ natural amino acids as linkers may be prone to unexpected artifacts compromising glycan recognition.

SummaryAn understanding of the suckering behaviour of micropropagated bananas is important not only in terms of commercial management but also to gain further appreciation of the physiological mechanisms involved in sucker development. Field studies showed that plants of micropropagated banana (Musa sp., AAA, Cavendish subgroup) produced significantly more suckers than plants grown from conventional planting material (sections of the rhizome with a lateral bud, termed bits). However, when bits were established in containers in a glasshouse and grown under the same conditions as micropropagated plants, the differences became less distinct. In fact, height, dry-matter accumulation and leaf area of the mother plants of micropropagated plants was similar to those of plants grown from containerized bits. Plants derived from bits that had been established directly in the field always lagged behind plants grown from the other two sources. The most significant difference between micropropagated plants and those g...

Trees of two mono-embryonic (‘Irwin’ and ‘Sensation’) and two poly-embryonic (‘Nam Dok Mai’ and ‘Kensington’) mango cultivars were exposed to winter temperatures to induce flowering. They were subsequently transferred into controlled environment glasshouse rooms under day/night temperature regimes of 15/5, 20/10, 25/15 and 30/20°C for 20 weeks. Inflorescence development only occurred on trees that were maintained at 20/10, 25/15 and 30/20°C. Higher temperatures generally increased the inflorescence size while there was an inverse effect on the mean number of flowers per inflorescence with 619.6 at 20/10°C decreasing to 431.3 at 30/20°C. There was an inverse relationship between the length of the anthesis period and temperature. Low temperatures at 20/10°C decreased the percent hermaphrodite flowers in poly-embryonic cultivars but increased the percentages in mono-embryonic cultivars. Style length and stigma width was reduced when the trees were held at 20/10°C compared to those trees held at either 25/15 or 30/20°C. Trees of ‘Kensington’ grown at 20/10°C mainly produced flowers which had short styles (0.62 mm) and small stigmatic surfaces while ‘Nam Dok Mai’ and ‘Irwin’ trees produced some flowers which had deformed ovaries or fused ovaries. A decrease in percent hermaphrodite flowers and floral changes which occur in poly-embryonic cultivars when inflorescences develop under low temperatures (20/10°C), are likely factors contributing to their low fruit set when grown in subtropical climates.

SummaryThe effect of a constant (10, 15, 20 or 25°C) or a diurnal maximum/minimum (15/5, 20/10, 25/15 or 30/20°C) incubation temperature on in vitro pollen germination and pollen tube growth in the pistils of two poly-embryonic (‘Kensington’ and ‘Nam Dok Mai’), and two mono-embryonic (‘Irwin’ and ‘Sensation’) mango cultivars was studied. In in vitro experiments where pollen was incubated in a liquid germination medium for 24 h in darkness, little difference was found between pollen germination of mono- and poly-embryonic cultivars. Averaged over the four cultivars, 53.9% of pollen germinated at 10°C, this increased to 76.2% when the incubation temperature was increased to 15°C, thereafter up to 25°C the percentage germination remained stable but germination decreased slightly to 68.2% at 30°C. Similarly, there was no difference in percent germination between cultivars when pollen was incubated under diurnal temperature regimes. Mean pollen germination of all four cultivars was 52.3% at 15/5°C and pollen g...

To study the effect of low temperature on inflorescence and floral development of mango (Mangifera indica L.), 'Nam Dok Mai', 'Kensington', 'Irwin' and 'Sensation' trees were exposed to natural winter temperatures to induce flowering, and then transferred to controlled-environment glasshouse rooms where day/night temperature regimes of 15/5 degrees, 20/10 degrees, 25/15 degrees and 30/20 degrees C were maintained for 20 weeks. Day/night temperatures of 15/5 degrees C severely inhibited the emergence and elongation of inflorescences of all cultivars with inflorescence development only occurring on trees that were maintained at the warmer temperatures (20/10 degrees, 25/15 degrees and 30/20 degrees C). The time taken for inflorescences to reach maximum length was 15-20 days on trees held at 25/15 degrees or 30/20 degrees C but extended to 54 days on trees kept at 20/10 degrees C. Warmer temperatures generally increased the inflorescence size of all cultivars, At 20/10 degrees C, pollen viability of 'Sensation' was significantly lower than the other cultivars, but there was no significant difference between cultivars held at 25/15 degrees and 30/20 degrees C, Low temperatures caused morphological changes in styles, stigmas, ovaries and anther size in all cultivars, and changes were especially pronounced in 'Kensington'. Style length and stigma width of all cultivars were reduced when trees were held at 20/10 degrees C compared to trees field at either 25/15 degrees or 30/20 degrees C. Trees of 'Kensington' grown at 20/10 degrees C mainly produced flowers that had short styles (0.62 mm) and small stigmas (0.09 mm) while 'Nam Dok Mai' and 'Irwin' trees produced some flowers with deformed or fused ovaries. Scanning electron microscopic studies indicated that normal 'Kensington' flowers had non-symmetrical stigmas that were covered with undeveloped papillae cells. The short-styled 'Kensington' flowers (produced at 20/10 degrees C) had a much smaller receptive stigmatic area compared to normal flowers produced at 30/20 degrees C. Low temperature-induced (20/10 degrees C) changes in ovary size in 'Nam Dolt Mai' and style length in 'Kensington' flowers may contribute to low fruit set in these two cultivars when grown in subtropical climates. (C) 1999 Elsevier Science B.V. All rights reserved.

SummaryThe effect of temperature on inflorescence development and sex expression in two mono-embryonic (`Irwin' and `Sensation'), and two poly-embryonic (`Nam Dok Mai' and `Kensington') mango cultivars was studied. Trees were subjected to natural winter temperatures to induce flowering prior to transfer into controlled environment glasshouse rooms under day/night temperature regimes of 15/5, 20/10, 25/15 and 30/208C for 20 weeks. Inflorescence development did not progress when trees were held at 15/58C. Cooler temperatures (20/108C) delayed the start of anthesis (42.4.d) compared with trees grown at 25/158C (23.d) and 30/208C (16.1.d). At 20/108C, the delay in the start of anthesis was greatest for `Sensation' (55.5.d) and least for `Nam Dok Mai' (25.5.d) while at other temperatures there was little difference between cultivars. The distribution of hermaphrodite flowers within the inflorescence was independent of temperature with the highest percentage found in the apical half of the inflorescence. There ...

In vertebrates, cytochrome P450s of the CYP2 and CYP3 families play a dominant role in drug metabolism, while in insects members of the CYP6 and CYP28 families have been implicated in metabolism of insecticides and toxic natural plant compounds. A degenerate 3' RACE strategy resulted in the identification of fifteen novel P450s from an alkaloid-resistant species of Drosophila. The strong (17.4-fold) and highly specific induction of a single gene (CYP4D10) by the toxic isoquinoline alkaloids of a commonly utilized host-plant (saguaro cactus) provides the first indication that members of the CYP4 family in insects may play an important role in the maintenance of specific insect-host plant relationships. Strong barbiturate inducibility of CYP4D10 and two other D. mettleri P450 sequences of the CYP4 family was also observed, suggesting a pattern of xenobiotic responsiveness more similar to those of several vertebrate drug-metabolizing enzymes than to putative vertebrate CYP4 homologs.

Summary Herpes simplex virus type 2 (HSV-2) can contribute to the spread of HIV. From March 2006 to November 2009, female sex workers (FSWs) in Yunnan, China were recruited into an open cohort study to determine incidence and risk factors for HSV-2 acquisition. Participants were interviewed and tested for HSV-2 and other sexually transmitted infections (STIs) every six months. A multivariate Cox proportional hazards regression model with time-dependent variables was used to measure associations with HSV-2 acquisition. In 3.5 years, 83 incident cases of HSV-2 infection were diagnosed, yielding an overall incidence of 21.9 per 100 person years (PY) (95% confidence interval [CI], 17.8–26.3). Working in higher risk commercial sex venues, current Neisseria gonorrhoeae infection, age of sexual debut

Sperm motility variables from the milt of the common carp Cyprinus carpio were assessed using a computer-assisted sperm analysis (CASA) system across several months (March-August 1992) known to encompass the natural spawning period. Two-year-old pond-raised males obtained each month were primed with an exogeneous hormone injection of carp pituitary extract and stripped of milt 18–24h later. The milt was diluted, activated and videotaped using a high-speed (200 Hz) videocamera and recorder. Videotaped samples were subsequently analysed using the CellTrak/S CASA system (Motion Analysis Corp.) for percent motility, curvilinear and straight-line velocity. In addition to assessing changes in motility parameters across several months, a comparison was made between two predilution/ activation media combinations (homologous seminal plasma/NaCl+HEPES v. 2-h incubation in 200 mM KCl+Tris/Tris). The percentage of motile cells assessed immediately after activation was significantly greater in the summer months (May, June, July) when compared to a spring sampling point (March); when assessed 1 min after activation, cells prediluted in seminal plasma maintained a higher percentage of motility than those prediluted in KC1. Curvilinear and straight-line velocities exhibited a slight seasonal trend; variations in response to the predilution treatments were observed with these measurements. Sperm count gradually increased through April and May (9–63 × 109 to 2–38 × lO10ml– 1 milt), declined in June and July (to 1–83 × lO10ml– 1 milt), and was followed by a steep increase in August (2–74 × 1010 ml– 1 milt). Mean seminal plasma osmolality remained relatively constant (250–265 mOsmol kg – 1) throughout the sampling period.

The phyllosphere microbial populations inhabiting the needles of three conifer species, Scots pine (Pinus sylvestris L.), Sitka spruce (Picea sitchensis L.) and Norway spruce (Picea abies (L.) Karst.), exposed to SO 2 and O 3 in an open-air fumigation experiment were analysed over a 3 year period using serial dilution after washing, direct plating and a fluorescein diacetate (FDA) enzyme assay. Total fungal populations ranged from 10 2 to 10 5 colony-forming units (CFU) g −1 fresh weight of needles. The dominant fungi isolated from needles varied with tree species and isolation technique; Aureobasidium pullulans (de Bary) Arnaud was most common on Scots pine and Norway spruce and white yeasts on Sitka spruce using the dilution plating method. However, direct plating of needle segments onto culture media indicated that Sclerophoma pythiophila (Corda) Hohnel was dominant on Scots pine and A. pullulans on Sitka and Norway spruce. Green needles of Sitka spruce were found to be endophytically colonized by Rhizosphaera kalkhoffii Bubak, but seldom by Lophodermium piceae (Fuckel) Hohn during extensive sampling in 1990. Statistical analyses revealed significant differences (P < 0.05) between plots in the 3 year mean of the total fungal populations or the fungal biomass (FDA assay) on all three tree species. Differences between plots were also observed for a number of dominant component species. Data were also analysed for treatment effects. A significant effect of SO 2 treatment was observed on the total fungal populations on Sitka spruce (P < 0.05) which were reduced markedly by the low-SO 2 treatment, while the O 3 treatment caused a significant increase in total fungal numbers on Scots pine (P < 0.05). The FDA activity on needles of both Scots pine and Sitka spruce was noticeably higher in the O 3 -only treatment plot, but the overall O 3 effect was not significant. Treatment effects were also detected on the occurrence of component species. The serial dilution method revealed an SO 2 effect (P < 0.05) of a reduction in the occurrence of pink yeasts on Sitka spruce and an O 3 effect (P < 0.05) of an increase in the occurrence of S. pythiophila on Sitka spruce (P < 0.01) but a decrease of Epicoccum nigrum Link and Cladosporium spp. on Scots pine. The direct-plating method revealed an SO 2 effect of an increase in S. pythiophila on Norway spruce (P < 0.05). Ozone treatment caused a significant increase in the isolation of a black strain of A. pullulans on Norway spruce (P < 0.05). Endophytic colonization of Sitka spruce needles by R. kalkhoffii was found to be increased on two occasions by O 3 exposure

This chapter presents procedures for the synthesis of α-vinyl amino acids, in which the usual α-proton is replaced by an unsubstituted vinyl group (Fig. 1). The parent member of this family, α-vinylglycine (R≠H), is a natural product (1,2) and acts as a suicide substrate for a number of PLP-dependent enzymes (4-9). Higher members of this family (R≠H) have also been synthesized (10-12). Several including α-vinyl-m-tyrosine (13-15), α-vinyl-DOPA (13-15), α-vinylglutamate (16), α-vinylornithine (17), α-vinyllysine (18), and α-vinylarginine (18) are Trojan horse inhibitors of their cognate amino acid decarboxylases (AADCs). Such (appropriately labeled) AADC inhibitors may also have potential as reagents for positron emission tomography (19). Fig. 1. Generic structure for α-vinyl amino acids.

Dichloroacetic acid (DCA) is a by-product of the chlorine disinfection of water and may occur in treated water at levels exceeding 100 micrograms/L. Previous studies revealed teratogenic effects, particularly heart malformations, at high doses (900-2,400 mg/kg given on days 6-15 of pregnancy). In a series of three studies, groups of 7-10 Long-Evans rats were dosed with 1,900 mg/kg of DCA on days 6-8, 9-11, or 12-15; with 2,400 mg/kg on days 10, 11, 12, or 13; and with 3,500 mg/kg on days 9, 10, 11, 12, or 13, in an attempt to determine the most sensitive period and further characterize the heart defect. In a fourth study, six dams were treated with 1,900 mg/kg of DCA days 6-15 of pregnancy, and 56 fetuses were harvested for light microscopy of the heart. Eight control fetuses from four litters were also examined. No heart malformations were seen in the groups treated with 1,900 mg/kg DCA days 6-8 but were present in the group treated on days 9-11 and 12-15, with the higher incidence occurring on days 12-15. Single doses of 2,400 mg/kg DCA given on days 10, 11, 12, or 13 resulted in a much lower incidence of cardiac malformations, which occurred only on days 10 and 12. The high dose of DCA (3,500 mg/kg) did not increase the incidence of heart defects but showed that dosing on day 9 as well as on days 10 and 12 would produce the defect. The defects seen were characterized as high interventricular septal defects (H-IVSD). Light microscopy showed that the defect was caudal to the semilunar valves, with the anterior right wall of the aorta communicating with the right ventricle. Another aspect of the defect is at the level of the semilunar valves, with the right cusp or sinus of Valsalva in communication with the right ventricle. The defects are discussed more fully and methods for further study suggested.

Dichloroacetic acid (DCA) is a principal by-product of the chlorine disinfection of water containing humic and fulvic acids, and is also a drug of interest in the therapeutic management of metabolic disorders. The developmental effects of DCA were evaluated in the pregnant Long-Evans rat. In two separate studies, animals were dosed by oral intubation on gestation days 6-15 (plug = 0) with 0, 900, 1,400, 1,900 or 2,400 mg/kg/day and 0, 14, 140, or 400 mg/kg/day. The vehicle control was distilled water. Maternal observations included clinical signs, weight change, and gross evaluation of organ weights and uterine contents at necropsy (day 20). Corpora lutea were counted and uteri stained for implantation sites. Live fetuses were examined for external, skeletal, and soft tissue malformations. Seven dams died during treatment (1,400 mg 1/19, 1,900 mg 2/19, 2,400 mg 4/21), and maternal weight gain was reduced at all except the lowest treatment levels. Liver, spleen, and kidney weights increased in a dose-related manner. The mean percentage of resorbed implants per litter was significantly elevated at greater than or equal to 900 mg/kg/day. Live fetuses showed dose-dependent reductions in weight and length at doses above 140 mg/kg. Statistically significant frequencies of soft tissue malformations ranged from 2.6% (140 mg/kg) to 73% (2,400 mg/kg). These were principally in the cardiovascular system and predominantly comprised defects between the ascending aorta and the right ventricle. Skeletal malformations were not observed in significant numbers in any dose group.(ABSTRACT TRUNCATED AT 250 WORDS)

Important determinants in the autoinhibitory domain of calcium/calmodulin-dependent protein kinase II (CaMK-II), corresponding to residues 281-302 of the kinase alpha-subunit sequence, were identified. Replacement of Thr286 with Ala (CaMK-(281-302 Ala286)) had no effect on either the potency (IC50 = 2 MicroM) or inhibitory mechanism (competitive with ATP) using the catalytic fragment of CaMK-II. Single replacement of charged residues in CaMK-(281-302, Ala286) identified His282, Arg283, Lys291, Arg297, and Lys298 as important determinants (greater than 10-fold increase in IC50) for potent inhibition of CaMK-II. Glu285, Asp288, Lys291, Arg296, and Lys300 were not as essential (less than 4-fold change in IC50) for potent CaMK-II inhibition. Replacement of either Arg283, Lys291, or Arg297, and Lys298 with Ala did not alter the ATP-competitive mechanism of inhibition although the Ki values increased 16-530-fold. However, replacement of His282 with Ala decreased the IC50 by 20-fold and altered the mechanism of inhibition to noncompetitive with respect to ATP. The non-protonated form of His282 was functionally active since decreasing the pH from 7.5 to 5.5 increased the IC50 of CaMK-(281-302, Ala286) almost 20-fold. Histidine protonation also appeared to disrupt the autoinhibitory domain of intact forms of CaMK-II since preincubation of non-proteolyzed rat brain CaMK-II with calcium/calmodulin (in the absence of ATP) at pH 5.5 generated up to 16% calcium-independent activity when assayed at pH 5.5. Similarly, the level of calcium-independent activity of a baculovirus-expressed Asp286 mutant CaMK-II ((D286)mCaMK alpha) increased to almost 80% calcium independence when assayed at pH 5.5 compared to only 20% when assayed at pH 7.5. The levels of calcium-independent activity of both the (D286)mCaMK alpha (at pH 5.5 and 7.5) and the rat brain CaMK-II (at pH 5.5) were sensitive to the concentrations of both ATP and peptide substrate (syntide-2) in the assays. These data suggest that the basic residues Arg283, Lys291, Arg297, and Lys298 are important for potent inhibition of CaMK-II and that the non-protonated form of His282 may play a unique role in the ATP-directed mechanism of inhibition by the CaMK-II autoinhibitory domain.

This chapter discusses the botany and history, importance, breeding and genetics, molecular genetics, micropropagation (to control viruses), somatic cell genetics, genetic manipulation and cryopreservation of banana and plantain.

Various types of bioreactors have been investigated for use in producing tissue-engineered human cartilage. These include rotating-wall vessels, spinner flasks, perfusion and compression/perfusion bioreactors. In each type of reactor the flow of the culture medium causes the growing tissue to experience a different dynamic environment, potentially influencing the character of the final tissue. Laboratory measurements have been made in model systems that obey requirements for dynamic similarity to prototype reactors. Local measurements of the velocity field made using particle-image velocimetry (PIV) permit the determination of local shear stresses within the observation plane, particularly in the vicinity of the tissue-construct model. Computationally, simulations have been performed with the commercial package FLUENT; these are compared with results from the laboratory experiments. We shall describe laboratory and numerical experiments conducted for various types of bioreactors used for the production of cartilage, focusing on those flow characteristics most likely to play a role in tissue development.