bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional analysis of a NAC‐type transcription factor OsNAC6 involved in abiotic and biotic stress‐responsive gene expression in rice
Authors: Nakashima Kazuo , Tran Lam‐Son P. , Van Nguyen Dong , Fujita Miki , Maruyama Kyonoshin , Todaka Daisuke , Ito Yusuke , Hayashi Nagao , Shinozaki Kazuo , Yamaguchi‐Shinozaki Kazuko
Published: June 2007

The OsNAC6 gene is a member of the NAC transcription factor gene family in rice. Expression of OsNAC6 is induced by abiotic stresses, including cold, drought and high salinity. OsNAC6 gene expression is also induced by wounding and blast disease. A transactivation assay using a yeast system demonstrated that OsNAC6 functions as a transcriptional activator, and transient localization studies with OsNAC6–sGFP fusion protein revealed its nuclear localization. Transgenic rice plants over‐expressing OsNAC6 constitutively exhibited growth retardation and low reproductive yields. These transgenic rice plants showed an improved tolerance to dehydration and high‐salt stresses, and also exhibited increased tolerance to blast disease. By utilizing stress‐inducible promoters, such as the OsNAC6 promoter, it is hoped that stress‐inducible over‐expression of OsNAC6 in rice can improve stress tolerance by suppressing the negative effects of OsNAC6 on growth under normal growth conditions. The results of microarray analysis revealed that many genes that are inducible by abiotic and biotic stresses were upregulated in rice plants over‐expressing OsNAC6. A transient transactivation assay showed that OsNAC6 activates the expression of at least two genes, including a gene encoding peroxidase. Collectively, these results indicate that OsNAC6 functions as a transcriptional activator in response to abiotic and biotic stresses in plants. We conclude that OsNAC6 may serve as a useful biotechnological tool for the improvement of stress tolerance in various kinds of plants.
TaVRT2 represses transcription of the wheat vernalization gene TaVRN1
Authors: Kane Ndjido Ardo , Agharbaoui Zahra , Diallo Amadou Oury , Adam Hélène , Tominaga Yoko , Ouellet François , Sarhan Fathey
Published: June 2007

In wheat, VRN1/TaVRN1 and VRN2/TaVRN2 determine the growth habit and flowering time. In addition, the MADS box transcription factor VEGETATIVE TO REPRODUCTIVE TRANSITION 2 (TaVRT2) is also associated with the vernalization response in a manner similar to TaVRN2. However, the molecular relationship between these three genes and their products is unknown. Using transient expression assays in Nicotiana benthamiana, we show that TaVRT2 acts as a repressor of TaVRN1 transcription. TaVRT2 binds the CArG motif in the TaVRN1 promoter and represses its activity in vivo. In contrast, TaVRN2 does not bind the TaVRN1 promoter and has no direct effect on its activity, but it can enhance the repression effect of TaVRT2. This suggests that a repressor complex regulates the expression of TaVRN1. In winter wheat, TaVRT2, TaVRN2 and TaVRN1 transcripts accumulate in the shoot apical meristem and young leaves, and temporal expression is consistent with TaVRT2 and TaVRN2 being repressors of floral transition, whereas TaVRN1 is an activator. Non‐vernalized spring wheat grown under a short‐day photoperiod accumulates TaVRT2 and shows a delay in flowering, suggesting that TaVRT2 is regulated independently by photoperiod and low temperature. The data presented suggest that TaVRT2, in association with TaVRN2, represses the transcription of TaVRN1.
Nonsense‐mediated mRNA decay (NMD) silences the accumulation of aberrant trypsin proteinase inhibitor mRNA in Nicotiana attenuata
Authors: Wu Jianqiang , Kang Jin‐Ho , Hettenhausen Christian , Baldwin Ian T.
Published: June 2007

In eukaryotes, genes carrying premature termination codons (PTCs) are often associated with decreased mRNA levels compared with their counterparts without PTCs. PTC‐harboring mRNA is rapidly degraded through the nonsense‐mediated mRNA decay (NMD) pathway to prevent the accumulation of potentially detrimental truncated proteins. In a native ecotype of Nicotiana attenuata collected from Arizona (AZ), the mRNA levels of a trypsin proteinase inhibitor (TPI) gene are substantially lower than in plants collected from Utah (UT). Cloning the AZ TPI gene revealed a 6 bp deletion mutation in exon 2 resulting in a PTC and decreased mRNA levels through NMD. Silencing UPF1, 2 and 3 in N. attenuata AZ plants by virus‐induced gene silencing (VIGS) enhanced the levels of PTC‐harboring TPI mRNA, demonstrating a conserved role for UPF genes in plants. Furthermore, using cell suspension cultures that express variants of the TPI construct, we demonstrate that both intron‐containing and intronless genes are subject to NMD in plants; unlike PTCs in mammals, PTCs downstream of introns activate NMD in plants. However, when a PTC is only 4 bp upstream of an intron, the NMD surveillance mechanism is abrogated. We also demonstrate that, in an intronless TPI gene, a PTC located at the beginning or the end of the coding sequence triggers NMD less efficiently than do PTCs located at the middle of the coding sequence. Taken together, these results highlight the complexity of the NMD activation mechanisms in plants.
Silencing of the major family of NBS–LRR‐encoding genes in lettuce results in the loss of multiple resistance specificities
Authors: Wroblewski Tadeusz , Piskurewicz Urszula , Tomczak Anna , Ochoa Oswaldo , Michelmore Richard W.
Published: June 2007

The RGC2 gene cluster in lettuce (Lactuca sativa) is one of the largest known families of genes encoding nucleotide binding site–leucine‐rich repeat (NBS–LRR) proteins. One of its members, RGC2B, encodes Dm3 which determines resistance to downy mildew caused by the oomycete Bremia lactucae carrying the cognate avirulence gene, Avr3. We developed an efficient strategy for analysis of this large family of low expressed genes using post‐transcriptional gene silencing (PTGS). We transformed lettuce cv. Diana (carrying Dm3) using chimeric gene constructs designed to simultaneously silence RGC2B and the GUS reporter gene via the production of interfering hairpin RNA (ihpRNA). Transient assays of GUS expression in leaves accurately predicted silencing of both genes and were subsequently used to assay silencing in transgenic T1 plants and their offspring. Levels of mRNA were reduced not only for RGC2B but also for all seven diverse RGC2 family members tested. We then used the same strategy to show that the resistance specificity encoded by the genetically defined Dm18 locus in lettuce cv. Mariska is the result of two resistance specificities, only one of which was silenced by ihpRNA derived from RGC2B. Analysis of progeny from crosses between transgenic, silenced tester stocks and lettuce accessions carrying other resistance genes previously mapped to the RGC2 locus indicated that two additional resistance specificities to B. lactucae, Dm14 and Dm16, as well as resistance to lettuce root aphid (Pemphigus bursarius L.), Ra, are encoded by RGC2 family members.
Optimized Architecture for Nutrition in the Avascular Retina of Megachiroptera
Authors: Brudenall D. K. , Schwab I. R. , Lloyd W. , Giorgi P. P. , Graydon M. L.
Published: June 2007

Investigations were undertaken to evaluate the unique choroidal vascular system of the Megachiroptera (fruit bats) and its possible significance for retinal nutrition. Fluorescein angiography was performed and documented on Pteropus poliocephalus. Vascular casts were made of the eye of Pteropus scapulatus. Histologic evaluation was performed on P. scapulatus. Results confirmed that each papilla has a vascular core, and a unique vascular system emanating from the optic disc. The histological appearance of the choroid and retina of P. scapulatus confirmed a vascular core to the papillae with a thin, but definite Bruch's membrane. Megachiroptera have a unique vascular system to supply nutrition to the retina consisting of capillary loops within a dense, uniform mosaic of choroidal projections or papillae, which permit the diffusion of metabolites to the retina and a heretofore undescribed vascular tuft emanating from the optic disc. We suggest that this vascular system provides nutrition by diffusion to a thick avascular retina, without any shadowing by vessels, and allows for nocturnal visual acuity and light‐gathering capabilities.
Developmental Changes of Seminiferous Tubule in Prenatal, Postnatal and Adult Testis of Bonnet Monkey (Macaca radiata)
Authors: Prakash S. , Prithiviraj E. , Suresh S.
Published: June 2007

This paper is a part of our study on the male reproductive system of bonnet monkey. The developmental changes in testis of bonnet monkey were studied qualitatively and quantitatively, at the light microscopy level. Testicular development appears to primarily involve tubular growth that starts immediately after birth. There is a gradual increase in the number of tubules in the prenatal to neonatal stage in testis, without an increase in the volume. Increase in the number of tubules in the neonatal testis was achieved by an increase in the length of the tubules and reduction in the interstitial proportion. Scattered spermatogonial cells in the tubules of neonatal testis indicate the rapid growth rate of the tubules. Increase in tubular length along with diameter seems to be a continuous process until puberty. This is the first report on the developmental changes in the testis during fetal, postnatal and adult stages in the bonnet monkey.
Extraembryonic membrane of the polyembryonic parasitoid Macrocentrus cingulum Brischke (Hym., Braconidae) is essential for evasion of encapsulation
Authors: Lu J.‐F. , Feng C.‐J. , Hu J. , Fu W.‐J.
Published: June 2007

Abstract:  The wasp Macrocentrus cingulum (Hymenoptera) is an endoparasitoid that uses larvae of the Asian corn borer Ostrinia furnacalis as one of its hosts. The wasp is polyembryonic and a single wasp egg gives rise to several dozens of embryos. Earlier studies showed that the fibrous layer on the surface of M. cingulum eggs protects them from the immune system of the moth larvae. However, the way in which the embryos of the parasitoid avoid being encapsulated remained unknown. In this paper, we show that the evasion of encapsulation is mediated through the extraembryonic membrane. We also show that M. cingulum embryos developed normally in the larvae of O. furnacalis but were encapsulated when injected into the larvae of Helicoverpa armigera, which is not a host species for the wasp larvae. When the extraembryonic membrane was removed, either chemically using the enzyme dispase or mechanically using a dissecting needle, the ‘unprotected’ embryos were also encapsulated both in vivo and in vitro by the haemocytes of the normal host O. furnacalis. It was also shown that the extraembryonic membrane was labelled strongly with fluorescein isothiocyanate (FITC)‐conjugated Helix pomatia (H.p.) lectin. This suggests that a chemical in, or on, the extraembryonic membrane, that helps the embryos of M. cingulum to avoid encapsulation, is possibly a glycodeterminant produced in the haemocoel of the wasp.
Effect of epicuticular waxes of poplar hybrids on the aphid Chaitophorus leucomelas (Hemiptera: Aphididae)
Authors: Alfaro‐Tapia A. , Verdugo J. A. , Astudillo L. A. , Ramírez C. C.
Published: June 2007

Abstract:  Insect response to plant surface features is a critical step in host‐finding and acceptance of herbivorous insects. The plant surface is usually covered with epicuticular waxes (EWs), which are not only involved in water physiology, but also provide resistance to insects. In the present work the probing behaviour and performance of the aphid Chaitophorus leucomelas Koch (Hemiptera: Aphididae) on dewaxed and waxed leaves of two poplar hybrids, [(Populus trichocarpa Torr. & Gray × Populus deltoides Bartram ex Marshall) × P. deltoides] (TD × D) and [(P. trichocarpa × Populus maximowiczii Henry) × (P. trichocarpa × P. maximowiczii)] (TM × TM), previously reported as susceptible and resistant, respectively, are described. Laboratory experiments showed that in naturally waxed leaves of the resistant hybrids, aphids devoted less time to probing and more time to non‐probing behaviour when compared with their behaviour on susceptible hybrids. These differences were not present when leaves of these hybrids were experimentally dewaxed. A field experiment demonstrated that aphid reproductive performance was affected by hybrid genotype (higher in the TD × D) but not by EWs, although a trend of lower performance on dewaxed leaves in both hybrids was apparent. SEM analysis of EWs revealed micromorphological differences between both hybrids. These results support the idea that EWs affect aphid behaviour in poplars, with a rather slight impact on reproductive performance.
Suppression of the stored‐product insect Tribolium confusum by Xylocoris flavipes and Amphibolus venator
Authors: Murata M. , Imamura T. , Miyanoshita A.
Published: June 2007

Abstract:  We evaluated the suppression of the confused flour beetle, Tribolium confusum, by the anthocorid bug Xylocoris flavipes and the reduviid bug Amphibolus venator. Four treatments were tested: X. flavipes adults, A. venator adults, X. flavipes adults and A. venator adults released, and control (no predators). After 25 days, X. flavipes alone showed 96.9% suppression of T. confusum, A. venator alone showed 76.2% suppression and both the predatory bugs together showed 95.6% suppression. The rates of loss of whole‐wheat flour as an index of damage caused by T. confusum were 2.7%, 6.4%, 3.6% and 11.7% in X. flavipes adults, A. venator adults, X. flavipes adults and A. venator adults released, and control respectively. Furthermore, A. venator attacked X. flavipes adults but not X. flavipes nymphs. The possibility of using both X. flavipes and A. venator against T. confusum is discussed.
Ground cover management does not influence densities of key Iridomyrmex species (Hym., Formicidae) in Australian citrus groves
Authors: Stevens M. M. , Madge D. G. , James D. G. , Diffey S. , Schiller L. J.
Published: June 2007

Abstract:  Ants in the genus Iridomyrmex cause extensive problems for citrus producers in southern Australia by disrupting the biological control of honeydew‐producing Hemiptera. We used baited pitfall traps to survey ant communities in 20 commercial citrus groves and test the hypothesis that populations of Iridomyrmex rufoniger gp spp. and Iridomyrmex purpureus can be reduced by conserving volunteer inter‐row vegetation. Nine groves (five in the Murrumbidgee Irrigation Area, New South Wales, and four in the Sunraysia area, Victoria) were classified as ‘bare’ groves, where inter‐row vegetation was routinely eliminated using herbicides and cultivation. The remaining ‘grassed’ groves (five in the MIA, six in Sunraysia) had inter‐row vegetation controlled only by intermittent mowing. All groves had been managed consistently for between 9 and 22 years. MIA groves were trapped on three occasions (October 1997, January 1998 and April 1998), and Sunraysia groves once (March 1999). Over 190 000 ants were recovered, with I. rufoniger gp spp. accounting for 74% of overall captures and dominating collections in both ‘bare’ and ‘grassed’ groves. A linear mixed model analysis showed that ground cover management history had no significant effect (P > 0.05) on captures of I. rufoniger gp spp., I. purpureus, other Dolichoderinae, Ponerinae, Formicinae or Myrmicinae. High variability between ant populations in groves under the same management regime in each region suggests that aspects of grove management may be affecting ant community composition, however, our results indicate that suppression of pest Iridomyrmex species cannot be reliably achieved simply by altering the management of volunteer inter‐row vegetation.
Is host selection in leafminer adults influenced by pre‐imaginal or early adult experience?
Authors: Facknath S. , Wright D. J.
Published: June 2007

Abstract:  Olfactometer and feeding/oviposition preference tests were carried out to study if host plant preference in two agromyzid leafminers, Liriomyza trifolii and Liriomyza huidobrensis, is influenced by pre‐imaginal or imaginal experience, and at what level (host plant species, host plant variety or host age). It was found that the choice of host plant species (potato or tomato) and host plant variety had a pre‐imaginal component, which could be reinforced (or modified) by an imaginal component. On the other hand, preference for potato leaves of different ages did not appear to be based on either pre‐imaginal or imaginal factors, but resulted from differential performance and oviposition preference. The Hopkins’ host selection principle appears to operate in these leafminers at the level of host species, and to some extent at the level of host variety, but not with respect to host age.
Reappearance of Cucumber mosaic virus Isolates Belonging to Subgroup IB in Tomato Plants in North‐eastern Spain
Authors: Aramburu J. , Galipienso L. , López C.
Published: June 2007

A disease characterized by symptomless leaves and fruit decolouration, loss of consistency and mild deformation on ripening was detected in tomato fields in north‐eastern Spain during 2003 and 2004. DAS‐ELISA analysis revealed the presence of the Cucumber mosaic virus (CMV) in all diseased plants. CMV isolates were characterized by polyacrylamide gel electrophoresis (PAGE) analysis of double‐stranded RNAs (dsRNAs) and nucleotide sequence analysis, and compared with some CMV isolates belonging to different subgroups used as controls. A total of 12 isolates obtained from the infected tomato plants selected for this study gave the same electrophoresis pattern for the three genomic dsRNAs, which was different to the patterns showed by the CMV isolates collected in the same region a few years ago. The identity of the complete nucleotide sequence of one of these CMV isolates and the partial sequence of other five isolates compared to the Tfn strain from Italy and the BAR92/1 isolate from tomato collected in Barcelona in 1992 was higher than 99%, both belonging to subgroup IB of CMV. The CMV isolates of this subgroup found in eastern Spain in previous studies were not detected after 1996. The nucleotide sequences of two isolates that were chosen as representatives of the CMV isolates more frequently detected in previous years revealed that they belonged to the CMV subgroups IA. The origin and the possible causes of reappearance of CMV IB isolates in north‐eastern Spain are discussed.
Effects of the Harvest Method on the Infestation of Chestnuts (Castanea sativa) by Insects and Moulds
Authors: Sieber T. N. , Jermini M. , Conedera M.
Published: June 2007

Chestnuts were collected either every 7 days from suspended nets used to intercept the fruits, every 2 days from the ground or every 7 days from the ground. Nuts were visually inspected after collection for the presence of exit holes of the chestnut weevil (Curculio elephas) and the chestnut moth (Cydia splendana), and 20 nuts per sampling and tree were bisected to assess fungal colonization. Apparently healthy nuts were incubated at 24°C and 70–80% relative humidity for 21 days. All nuts were bisected after incubation and examined for the presence of insects and moulds. The harvest method did not have a statistically significant effect on either moulding or insect infestation except onAmphiporthe castanea. This vertically transmitted fungal endophyte was less frequently isolated from fruits collected after 7 days from the ground. The black rot fungusCiboria batschianadid not occur in chestnuts intercepted in nets, but the difference to chestnuts collected from the ground was statistically not significant. The frequency of nuts colonized byC. batschianawas low in general probably due to the hot and dry summer in 2003. Big, marketable fruits appeared to be less frequently colonized by insects and moulds right after collection. This difference disappeared after incubation except for the chestnut moth. The mother tree had the greatest effect on fungal and insect infestation, indicating the importance of the genetic disposition and/or the phytosanitary situation of each tree. The chestnut weevil preferred chestnuts of the variety ‘Lüina’ to those of the variety ‘Torcion’, whereas the fungiA. castanea,Trichothecium roseum,Clonostachys roseaandPenicilliumspp. preferentially colonized chestnuts of the variety ‘Torcion’.
Determination of Deoxynivalenol and Nivalenol Chemotypes of Fusarium graminearum Isolates from China by PCR Assay
Authors: Ji L. , Cao K. , Hu T. , Wang S.
Published: June 2007

Fusarium graminearum is the main causative agent of cereal scab and maize cob rot in China. Two hundred and fifty‐five F. graminearum isolates were obtained from wheat, barley and maize from Hebei, Heilongjiang and Hubei, provinces with distinct climate conditions and cropping systems. The isolates were confirmed to be F. graminearum by polymerase chain reaction (PCR) assay using F. graminearum species‐specific primers Fg16F/Fg16R. Two populations, 7C1 and 6A5, were identified to exist in China. The 6A5 population was predominant in Hubei in central China along the Yangtze River, whereas the 7C1 population was predominant in Heilongjiang and Hebei in northern China. Based on sequences of Tri13 and Tri3, genes involved in the mycotoxin biosynthetic pathway, PCR assays were used to detect 3‐acetyldeoxynivalenol (3‐ADON), 15‐acetyldeoxynivalenol (15‐ADON) and nivalenol (NIV) chemotypes. All three chemotypes of F. graminearum were identified, with 15‐ADON chemotype predominating overall. A greater proportion of 3‐ADON chemotype was found in Hubei, whereas a greater proportion of 15‐ADON was found in Heilongjiang and Hebei.
Identification and Regulation of Genes from a Biocontrol Strain of Fusarium oxysporum
Authors: Fravel D. R. , Moravec B. C. , Bailey B. A.
Published: June 2007

Differential display with three time points revealed that thiram altered expression of numerous genes in the biocontrol fungus Fusarium oxysporum CS‐20. Of the 101 bands purified from the differential display gel, 86 were successfully cloned, and 64 sequenced. Based on nucleic acid sequences, homology to known products was found using BLASTn for 26 sequences and homology to hypothetical proteins was found for six sequences, also from Gibberella zeae. One band (BM1 24‐1) showed homology to an ABC transporter from three different fungi. Because of its association with detoxification functions, the ABC transporter was selected for further study. Mycelia of CS‐20 were exposed to 25 μg active ingredient (a.i.) thiram in liquid culture for various times from 0 to 8 h. Quantitative real‐time PCR was used to evaluate gene expression. At 30 min after treatment with thiram, the ABC transporter was upregulated 20‐ to 25‐fold relative to the control treatment. The ABC transporter was upregulated 15‐fold at 1 h after treatment and 10‐fold at 2 h. At 8 h after treatment, there was no difference between treated and non‐treated for expression of the ABC transporter. Transcription of the gene encoding EST BM1 24‐1 is induced in response to thiram treatment and may function in providing resistance in F. oxysporum isolate CS‐20 to fungicides and other toxins. Tolerance to toxins may be critical to the successful inclusion of CS‐20 in disease control strategies in cropping systems.
Phylogenetic Analysis of Iris yellow spot virus Isolates from Onion (Allium cepa) in Georgia (USA) and Peru
Authors: Nischwitz C. , Pappu H. R. , Mullis S. W. , Sparks A. N. , Langston D. R. , Csinos A. S. , Gitaitis R. D.
Published: June 2007

Iris yellow spot virus (IYSV) was first observed in sweet onions in Georgia (USA) in 2003 in the Vidalia region. The virus had been reported in the onion‐growing regions in western USA several years before being detected in Georgia in the east. Although symptoms were observed on onions in Peru several years earlier, the presence of IYSV was not confirmed in Peru until after the virus was detected in Georgia. We characterized nine isolates of IYSV recovered from sweet onions in both Georgia (four isolates) and Peru (five isolates) by sequencing the nucleocapsid (N) gene and compared those sequences with sequences available in GenBank. Sequence divergence between IYSV isolates from Georgia and Peru was low with 1.1%, and comparisons with IYSV isolates from other regions showed divergence of up to 11.4%. Bootstrap analysis indicated with a high degree of confidence that the Georgia and Peruvian isolates fell into the same clade and were different from known isolates from western USA that fell into sister clades. The high degree of similarity between Georgia and Peruvian isolates suggests that gene flow occurred from Peru into Georgia.
Evaluation of Water Yam (Dioscorea alata L.) Germplasm for Reaction to Yam Anthracnose and Virus Diseases and their Effect on Yield
Authors: Egesi C. N. , Odu B. O. , Ogunyemi S. , Asiedu R. , Hughes J.
Published: June 2007

Use of genetic resistance is the most practical and economic way to manage major diseases of yams. In a search for sources of resistance, 40 water yam (Dioscorea alata L.) accessions from Benin, Ghana, Nigeria and Puerto Rico were screened under natural disease infection conditions in Ibadan, Nigeria. The accessions were evaluated at 1, 3 and 6 months after planting (MAP) for severity of yam anthracnose and viral diseases. The effect of the pathogens on yield was also evaluated at harvest 9 MAP. There were significant differences (P < 0.001) between accessions for severities of anthracnose and viral diseases. Eight (20%) of them had lower anthracnose area under disease progress curves (AUDPC) values than the resistant check while 10 (25%) had AUDPC values below the trial mean. There were significant variations (P < 0.001) in yield components among the accessions. There was significant negative correlation of anthracnose severity with fresh tuber yield (r = −0.51) and with number of tubers per plot (r = −0.40). Similarly, significant negative correlations were observed of virus disease severity with fresh tuber yield (r = −0.78) and number of tubers per plot (r = −0.65). Linear regression models also showed that the fresh yield had significant negative relationships with anthracnose (R2 = 0.26) and viral (R2 = 0.62) diseases. The accessions identified as resistant constitute a valuable resource for breeding of resistant germplasm.
Eradication of Polymyxa betae by Thermal and Anaerobic Conditions and in the Presence of Compost Leachate
Authors: Van Rijn E. , Termorshuizen A. J.
Published: June 2007

The abiotic conditions required for eradication of Polymyxa betae, the vector of Beet necrotic yellow vein virus in sugar beet, were investigated. Survival of resting spores of P. betae was determined under aerobic (30 min, 4 days and 21 days) and anaerobic (4 days) conditions under several temperature regimes in a water suspension and in leachate extracted from an aerobic compost heap. In water under aerobic conditions the lethal temperature was 60, 55 and 40°C for exposure times of 30 min, 4 days and 21 days, respectively. The effect of compost leachate and/or anaerobic conditions on survival of P. betae depended on temperature. After incubation for 4 days at 20°C, no significant effects of anaerobic conditions or leachate on the survival of P. betae were found. However, at 40°C for 4 days under anaerobic conditions, survival of P. betae was significantly lower than survival under aerobic conditions in water as well as in leachate. In leachate taken from an aerobic compost heap, aerobically incubated at 40°C for 4 days, survival of P. betae was significantly lower than survival in water at the same temperature. As anaerobic spots are prevalent in aerobic compost heaps, especially during the thermophilic phase, actual inactivation temperatures under composting conditions are likely to be lower than the temperatures we found for eradication in water under aerobic conditions.
Characterization of Synergy between Cucumber mosaic virus and Tobacco necrosis virus in Nicotiana benthamiana
Authors: Xi D. , Feng H. , Lan L. , Du J. , Wang J. , Zhang Z. , Xue L. , Xu W. , Lin H.
Published: June 2007

Mixed infections of Nicotiana benthamiana plants by Cucumber mosaic virus (CMV) and Tobacco necrosis virus (TNV) exhibit a synergistic interaction and result in symptom enhancement. Accumulation of CMV(+) RNA as well as capsid protein (CP) in mixed infection was considerably higher than that of singly‐infected plants. There was also a slight increase in TNV(+) RNA and CP levels in doubly infected plants. Synergistic infection by CMV‐ and TNV‐induced higher increase in the levels of malonyldialdehyde, hydrogen peroxide (H2O2) and more decline in the activities of catalase than singly infected ones. Both peroxidase and superoxide dismutase activities increased rapidly for the first 10 days post inoculation (dpi) in doubly‐infected plants and then declined, whereas the enzyme activities continued to increase after 10 dpi in singly infected plants and had higher enzyme activities in the late stages than that of co‐infected plants. These results suggest that synergistic infection by CMV and TNV produced severes oxidative stress in N. benthamiana plants and the synergy between the two viruses was mutual.
Health‐enhancing effects of engaging in productive occupation: Experiences of young people with mental illness
Authors: Iannelli Sophia , Wilding Clare
Published: June 2007

Background/aim:  This paper investigates the relationship between productive occupation and mental well‐being for young people with a mental illness. In doing so, it aims to increase the understanding of applying occupation therapeutically.

Methods:  Four young people who experienced mental illness were interviewed about their engagement in productive occupations. Interviews were audiotaped and transcribed. Transcripts were analysed and categorised into four themes.

Findings:  The participants found that the obligatory nature of productive occupations encouraged engagement in occupation; responsibility gained from work or study helped develop a positive sense of self; accomplishments achieved through engaging in productive occupations enhanced self‐worth; and engaging in productive occupations helped foster hope.

Conclusion:  Engaging in productive occupations is found to enhance the mental health and well‐being of participants and thus accentuates that meaningful productive occupations can be a valuable aspect to occupational therapy practice.
The Four‐Quadrant Model of Facilitated Learning (Part 2): strategies and applications
Authors: Greber Craig , Ziviani Jenny , Rodger Sylvia
Published: June 2007

Occupational therapists routinely use a variety of learning strategies as part of their engagement with clients. This paper is the second of a two‐part presentation of the Four‐Quadrant Model of Facilitated Learning (4QM), a client‐centred means of employing teaching–learning approaches to intervention. The first paper examined the way teaching–learning approaches can be used in occupational therapy. The current paper discusses the ways that various learning strategies can be used as therapeutic tools. Useful learning strategies are grouped according to purpose and presented in the 4QM as a coordinated way of organising therapeutic intervention. In this way, the 4QM is posited to enhance the repertoire of strategies from which therapists can draw, and to help coordinate the learning process over time. The 4QM is advanced as a way of informing clinical reasoning in teaching–learning approaches to occupational therapy by providing a means of understanding how and when various strategies are most appropriately used. Although grounded in theories of child learning, applications to adult learning may also be possible.
Solid–papillary carcinoma of the breast: Clinicopathological study of 20 cases
Authors: Otsuki Yoshiro , Yamada Makoto , Shimizu Shin‐ichi , Suwa Kaori , Yoshida Masayuki , Tanioka Fumihiko , Ogawa Hiroshi , Nasuno Hironari , Serizawa Atsushi , Kobayashi Hiroshi
Published: June 2007

The purpose of the present paper was to evaluate the clinicopathological and biological features of 20 Japanese patients with solid–papillary carcinoma of the breast (SPC) or SPC associated with invasive breast cancer. All the patients were Japanese women, including two sisters. The mean age was 66.0 years. The incidence of SPC among all the breast cancers treated at two institutions was 1.1% and 1.7%, respectively. The mean disease‐free interval was 4 years 11 months. Axillary lymph node metastasis or tumor recurrence did not occur in any of the cases. Fifteen cases of SPC contained invasive cancers that ranged from <5% to 60% of the entire tumor area. Histological types of invasive cancers were mucinous carcinoma in five cases and neuroendocrine cell carcinoma in 10 cases. These results indicate that SPC is a potential precursor lesion for neuroendocrine carcinoma as well as mucinous carcinoma. When all the cases were classified and analyzed according to both the 2002 tumor node metastasis (TNM) classification system and the Nottingham histological grade, SPC patients, even those with invasive cancers, seemed to have longer disease‐free survival compared to patients with the other invasive breast cancers of matching grade and stage. Clinicopathologically, SPC could be regarded as a separate type of ductal carcinoma in situ.
Missense mutation with/without nonsense mutation of the p53 gene is associated with large cell morphology in human malignant lymphoma
Authors: Mitani Shoko , Kamata Hiroshi , Fujiwara Mutsunori , Aoki Naoto , Okada Shuji , Watanabe Masato , Tango Toshiro , Mori Shigero
Published: June 2007

Mutations in p53 gene exons 5–9 were studied in 44 non‐Hodgkin's lymphomas (NHL) consisting of 35 B‐NHL and 9 T‐NHL. Missense mutations were found in two diffuse large B‐cell lymphomas (DLBL) and one peripheral T‐cell lymphoma (unspecified). Double transversion missense and nonsense mutations were detected in one DLBL and one adult T‐cell leukemia/lymphoma. Silent mutations were found in two DLBL. Detailed histomorphological study showed that cases harboring p53 missense mutation with/without nonsense mutation tended to have larger nuclei with much more prominent nucleoli. Cytomorphometric analysis was therefore conducted by measuring the gross area of 100 lymphoma cell nuclei in 44 cases and the results were compared between lymphomas harboring p53 missense mutation with/without nonsense mutation and lymphomas harboring p53 silent mutation or lacking mutation. It was found that the lymphomas harboring p53 missense mutation with/without nonsense mutation had a highly significantly larger nuclear gross area than lymphomas with silent p53 mutation or lacking mutation (two‐sample t‐test, P < 0.00001; Exact Wilcoxon rank–sum test, P < 0.00001). This result suggests that p53 mutation might induce enlargement of neoplastic cell nuclei by some molecular mechanism.
Factors influencing short‐term re‐admission and one‐year mortality in patients with chronic obstructive pulmonary disease
Authors: LIU Shih‐Feng , LIN Kuan‐Chun , CHIN Chien‐Hung , CHEN Yung‐Che , CHANG Hsueh‐Wen , WANG Chih‐Chou , LIN Meng‐Chih
Published: June 2007

Background and objectives:  Fourteen day re‐admission rates are deemed to be an important indicator of the quality of medical care for COPD in Taiwan. This study identified the characteristics of patients with COPD who required short‐term re‐admission and analysed the risk factors for 1‐year mortality.

Methods:  Consecutive patients with COPD who were re‐admitted to hospital within 14 days of discharge and a random computer generated selection of patients with COPD not re‐admitted within 14 days of discharge were recruited to the study and their medical data collected from hospital records. Recruitment occurred over an 18‐month period.

Results:  Fifty patients were recruited to each group. Multivariate analysis revealed statistically significant differences in oral steroid use (P = 0.013) and FEV1 (P = 0.04) between the re‐admission group and non‐re‐admission group. Of the many variables assessed, risk of death within 1 year of discharge was significantly associated with re‐admission within 14 days alone (P = 0.02; odds ratio = 15.01).

Conclusion:  COPD patients using long‐term oral corticosteroids and with a low FEV1 are at risk of re‐admission with 14 days of hospital discharge, and medical care of these patients warrants much greater attention.
Efficacy and safety of once‐daily inhaled ciclesonide in adults with mild to moderate asthma: A double‐blind, placebo‐controlled study*
Authors: ADACHI Mitsuru , ISHIHARA Kyosuke , INOUE Hiroshi , KUDO Koichiro , TAKAHASHI Kiyoshi , MORITA Yutaka , MASUDA Ken‐Ichi , TAKADA Yoshinori , KATO Ryuichi , MIYAMOTO Terumasa
Published: June 2007

Background and objective:  Inhaled corticosteroids are recommended as first‐line therapy for the management of asthma, although side‐effects may limit their use. Ciclesonide, a novel pro‐drug inhaled corticosteroid, exerts potent and prolonged local anti‐inflammatory effects in the lungs, and is considered to have an improved safety and tolerability profile. The aim of this study was to evaluate the efficacy and safety of ciclesonide in adult patients with mild to moderate asthma.

Methods:  A placebo‐controlled, multicentre, randomized, double‐blind, parallel‐group study was conducted. During the 4‐week baseline period, patients were given 400 μg/day of beclomethasone dipropionate in a chlorofluorocarbon formulation. After the baseline period, 311 patients were given once‐daily 100, 200 or 400 μg of ciclesonide or placebo for an 8‐week treatment period without the use of a spacer. The primary efficacy variable was morning PEF.

Results:  Changes in the morning PEF (least squares mean) at the end of the study were 4.23 L/min (P < 0.001) in the 100 μg group, 3.75 L/min (P < 0.001) in the 200 μg group, −0.40 L/min (P < 0.001) in the 400 μg group, as compared with −24.95 L/min in the placebo group. In the ciclesonide groups, the PEF remained at the same level as the baseline period. No large differences were observed between the placebo group and the ciclesonide groups regarding safety.

Conclusion:  Once‐daily administration of ciclesonide at doses of 100, 200 or 400 μg was shown to be effective in adult patients with mild to moderate asthma. Ciclesonide is considered to have favourable safety profiles and be well tolerated.
Sex‐based hatching asynchrony in an oviparous lizard (Bassiana duperreyi, Scincidae)
Authors: RADDER RAJKUMAR S. , SHINE RICHARD
Published: June 2007

Abstract  Sex disparities in mean dates of hatching are widespread, but are generated by a variety of mechanisms. For example, a correlation between offspring sex and hatching date is produced by temperature‐dependent sex determination (TSD) in turtles and lizards, and by laying asynchrony and differential incubation behaviours in birds. Our laboratory experiments on montane lizards (Bassiana duperreyi, Scincidae) provide the first direct evidence of an intrinsic sex effect on the date of hatching in a reptile. All eggs within a clutch are laid on the same day but, even when incubated under identical thermal and hydric conditions, male lizards hatch about 2 days earlier than do their sisters. The effects are not due to laying asynchrony, differential incubation by parents, TSD or sex differences in mean egg size. Hormonally induced sex reversal did not eliminate the sex disparity in incubation periods, suggesting that this sex disparity is due to events occurring prior to oviposition rather than to sexual differences following gonadal differentiation. In the field, the intrinsically briefer incubation of male embryos is counterbalanced by two other trends: smaller eggs more often produce males and tend to hatch later than larger eggs within the same clutch; and cooler (and thus, later‐hatching) nests overproduce male offspring via thermally induced sex reversal. Thus, somewhat ironically, the sex‐specific hatching asynchrony of laboratory‐incubated eggs may reflect adaptation to minimize sex differences in dates of hatching.
Mistletoe fruit‐colour polymorphism and differential success in a habitat mosaic
Authors: BACH CATHERINE E. , KELLY DAVE
Published: June 2007

Abstract  Polymorphisms in fruit colour are common in nature, but mechanistic explanations for the factor(s) responsible for their maintenance are for the most part lacking. Past studies have focused on frugivore colour preferences and fruit removal rates, but until recently there has been no evidence that these factors are responsible for the maintenance of the polymorphisms. For other types of genetic polymorphisms, habitat heterogeneity has been shown to play a role in their maintenance. Here we test the habitat heterogeneity hypothesis for a polymorphic New Zealand mistletoe. We show that red‐fruited and orange‐fruited morphs of the mistletoe Alepis flavida (Hook. F) Tiegh. (Loranthaceae) differ in their growth, mortality and flowering on forest edges and in forest interior. Red‐fruited morphs, which are preferred by dispersers, grew, survived and flowered as well as orange‐fruited morphs on edges, whereas orange‐fruited morphs had much greater growth, survival, and flowering than red‐fruited morphs in the forest interior. This is the first evidence that habitat‐specific differences in growth and survival may contribute to maintaining fruit‐colour polymorphisms.
Effect of landscape position on the acidification of loess‐derived soils underPinus radiata
Authors: AMIOTTI N. M. , BRAVO O. , ZALBA P. , PEINEMANN N.
Published: June 2007

Abstract Interactions between landscape position and the acidifying effect of trees planted into loess‐derived grassland soils were studied in the Ventana region of Argentina. Forests ofPinus radiataplanted at the end of 1940, were selected in two different positions from the landscape, plains and slopes. Samples of the soil surface mineral horizon were taken from landscape positions at four distances from the trees and compared with grassland soils. The values of the main soil chemical properties changed significantly with distance from trees, with a decrease in pH, base saturation, exchangeable Ca2+, Mg2+and K+, and increase in Na+, Al3+and particularly H+closer to the trees. This pattern confirms the prominent role of vegetation in bringing about changes in soil properties. Regression models showed high levels of explanation (r2 > 0.85) indicating that a high percentage of the spatial variability of soil chemical properties is systematic and predictable with distance from the trees. The pH in KCl proved an excellent tool for predicting the cationic composition of soils. Organic carbon and total nitrogen were significantly higher in the plains positions than in the slopes under the trees, whereas there was no difference under grassland. The slopes of the regression lines indicated that acidification is more intense in soils on the plains. Vegetation was the main factor influencing acidification of the studied soils. The landscape position regulates the bio‐hydrological factor and thus the speed of acidification process.
Habitat selection and web plasticity by the orb spider Argiope keyserlingi (Argiopidae): Do they compromise foraging success for predator avoidance?
Authors: BLAMIRES SEAN J. , THOMPSON MICHAEL B. , HOCHULI DIETER F.
Published: June 2007

Abstract  Orb web spiders face a dilemma: forage in open habitats and risk predation or forage in closed habitats to minimize risk but at reduced foraging profitability. We tested whether Argiope keyserlingi opts for safer habitats at the expense of foraging success by (i) determining habitat selection indices in open and closed habitats; (ii) marking and releasing individual juvenile, subadult and adults over two 4‐week periods to determine if life‐history stage influences habitat selection; and (iii) determining the biotic and abiotic environmental parameters that relate to A. keyserlingi abundance. We found that A. keyserlingi selected closed habitats. Sedge and anthropogenic structures were selected and trees were avoided. Juveniles were never found in open habitats, most likely because of high postdispersal mortality. Subadults and adults may shift from closed to open habitats while juveniles never shifted habitat. Foliage density, plant height, potential prey abundance, and mantid and bird abundance were correlated with A. keyserlingi abundance, with only bird abundance explaining habitat selection. We measured web capture area, spiral distance (distance between spiral threads) and the number of decoration arms (0, 1, 2, 3 or 4) in the field and did laboratory experiments to test the influence of (i) space and vegetation; (ii) prey abundance; and (iii) web damage, on web architecture. Argiope keyserlingi webs exhibited geometric plasticity by having larger prey capture areas and spiral distances in open habitats. Decoration design did not differ between habitats however. Variation in space availability, air temperature, prey abundance and web damage explained the variations in web architecture. Potential prey size and diversity differed between habitats but prey abundance did not. As large prey may be important for spider survivorship, foraging success appears to be compromised by occupying closed habitats.
Using species accumulation curves to estimate trapping effort in fauna surveys and species richness
Authors: THOMPSON GRAHAM G. , THOMPSON SCOTT A.
Published: June 2007

Abstract  The shape of species accumulation curves is influenced by the relative abundance and diversity of the fauna being sampled, and the order in which individuals are caught. We use resampling to show the variation in species accumulation curves caused by the order of trapping periods. Averaged species accumulation curves calculated by randomly assigning the order of trapping periods are smooth curves that are a better estimate of species richness and a more useful tool for determining the trapping effort required to adequately survey a site. We extend this concept of randomly resampling the trapping period to show that randomizing the number of individuals caught for each species over the number of collection periods (e.g. days) can provide an accurate estimate of the averaged species accumulation curve. This is particularly useful as it enables an accurate estimation of the proportion of the total number of species caught in an area during a survey from information on the number of individuals caught for each species and the number of trapping periods, and is not dependent on having knowledge of the trapping period in which each individual was caught. This calculation also enables an assessment to be made of the adequacy of fauna surveys to report a species inventory in environmental impact assessments when only a species list and relative abundance data are provided.
The response of riparian vegetation to flood‐maintained habitat heterogeneity†
Authors: WINTLE BONNIE C. , KIRKPATRICK J. B.
Published: June 2007

Abstract  Riparian environments are subject to the scouring and depositional effects of floods. Riparian vegetation and substrates are scoured during high flows, while litter and sediment is deposited downstream. In the Prosser and Little Swanport River catchments in south‐east Tasmania, vascular plant species were surveyed in large riparian relevés. Within these relevés, 1 × 1 m subplots were placed in both flood‐scoured and depositional environments. Species composition was compared between these three datasets, to investigate the importance of floods in determining species richness and species composition of riparian vegetation. Species richness and diversity were highest in areas experiencing flood scour. Herbs appear particularly reliant on the creation of gaps for colonization, and some major riparian shrub species may also require disturbance to maintain their abundance. The depositional environment tended to favour shrubs and graminoids. Given that differences in species composition are related to flood‐induced features of the riparian environment, the regulation of these rivers might reduce the diversity of the riparian vegetation downstream of dams.