bluuebunny/crossref_metadata_2025 huggingface dataset:
Stomatal density, anatomy and nutrient concentrations of Scots pine needles are affected by elevated CO2 and temperature
Authors: LUOMALA EEVA‐MARIA , LAITINEN KAISA , SUTINEN SIRKKA , KELLOMÄKI SEPPO , VAPAAVUORI ELINA
Published: June 2005

Stomatal density, anatomy and nutrient concentrations of Scots pine (Pinus sylvestris L.) needles were studied during 3 years of growth at elevated CO2 (693 ± 30 µmol mol−1), at elevated temperature (ambient +2·8–6·2 °C depending on the time of the year) and in a combination of elevated CO2 and temperature in closed‐top chambers. The treatments were started in August 1996. At elevated temperature, the needles that were grown in the first year (i.e. the 1997 cohort) were thinner, had thinner mesophyll in the abaxial side, thinner vascular cylinder and lower stomatal density than those grown at ambient temperature. The proportion of mesophyll area occupied by vascular cylinder or intercellular spaces were not changed. Lower stomatal density apparently did not lead to decreased use of water, as these needles had higher concentrations of less mobile nutrients (Ca, Mg, B, Zn and Mn), which could indicate increased total transpiration. In the 1997 and 1998 cohorts, elevation of temperature decreased concentrations of N, P, K, S and Cu. In the 1999 cohort, contradictory, higher concentrations of N and S at elevated temperature may be related to increased nutrient mineralization in the soil. Elevation of CO2 did not affect stomatal density, needle thickness, thickness of epidermis or hypodermis, vascular cylinder or intercellular spaces. Concentrations of N, P, S and Cu decreased at elevated CO2. Reductions were transient and most distinct in the 1997 cohort. The effects of CO2 and temperature were in some cases interactive, which meant that in the combined treatment stomatal density decreased less than at elevated temperature, and concentrations of nutrients decreased less than expected on the basis of separate treatments, whereas the thickness of the epidermis and hypodermis decreased more than in the separate treatments. In conclusion, alterations in the anatomy and stomatal density of Scots pine needles were more distinct at elevated temperature than at elevated CO2. Both elevated CO2 and temperature‐induced changes in nutrient concentrations that partly corresponded to the biochemical and photosynthetic alterations in the same cohorts (Luomala et al. Plant, Cell and Environment26, 645–660, 2003) Reductions in nutrient concentrations and alterations in the anatomy were transient and more evident in the needle cohort that was grown in the first treatment year.
Differential accumulation of maysin and rhamnosylisoorientin in leaves of high‐altitude landraces of maize after UV‐B exposure
Authors: CASATI PAULA , WALBOT VIRGINIA
Published: June 2005

Flavonoid induction by UV‐B was investigated in five maize landraces from high altitudes and a W23 inbred line lacking the B1 and Pl1 transcription factors required for anthocyanin synthesis. In their natural habitats these landraces receive much higher UV‐B fluence than plants at lower altitudes at similar latitudes and would be predicted to have UV‐B tolerance by recurrent selection against UV‐B stress. We identified two flavones that are induced by UV‐B in leaves of high‐altitude lines: maysin and its biosynthetic precursor rhamnosylisoorientin. Accumulation is controlled by a p‐homologous transcription factor expressed in leaves, and this factor is regulated by UV‐B. The levels of either maysin or rhamnosylisoorientin are higher in seedling leaves than in subsequent leaves; the highest flavone concentration was detected in silks. Some landraces have only rhamnosylisoorientin; this likely reflects a mutation in salmon silk1 (sm1) or in a duplicate locus, as genetic crosses with W23 restore the production of maysin in heterozygous F1 plants. In conclusion, it is demonstrated that maize plants from high altitudes respond to UV‐B radiation by accumulating UV‐absorbing flavones in leaves; in contrast, these compounds are present at only very low levels in inbred lines such as W23 and are not regulated by UV‐B.
Inter‐vessel pitting and cavitation in woody Rosaceae and other vesselled plants: a basis for a safety versus efficiency trade‐off in xylem transport
Authors: WHEELER JAMES K. , SPERRY JOHN S. , HACKE UWE G. , HOANG NGUYEN
Published: June 2005

The hypothesis that greater safety from cavitation by air‐seeding through inter‐vessel pits comes at the cost of less porous pit membranes with greater flow resistance was tested . Sixteen vessel‐bearing species were compared: 11 from the Rosaceae, four from other angiosperm families, and one fern. Unexpectedly, there was no relationship between pit resistance (and hence the prevailing membrane porosity) and cavitation pressure. There was, however, an inverse relationship between pit area per vessel and vulnerability to cavitation (r2 = 0.75). This suggests that cavitation is caused by the rare largest membrane pore per vessel, the average size of which increases with total pit area per vessel. If safety from cavitation constrains pit membrane surface area, it also limits vessel surface area and the minimum vessel resistivity. This trade‐off was consistent with an approximately three‐fold increase in vessel resistivity with cavitation pressure dropping from −0.8 to −6.6 MPa. The trade‐off was compensated for by a reduction in the percentage of vessel wall pitted: from 10–16% in vulnerable species to 2–4% in resistant species. Across species, end‐wall pitting accounted for 53 ± 3% of the total xylem resistivity. This corresponded to vessels achieving on average 94 ± 2% of their maximum possible conductivity if vessel surface area is constrained.
Respiratory Vaccination of Mice Against Influenza Virus: Dissection of T‐ and B‐Cell Priming Functions
Authors: Coleclough C. , Sealy R. , Surman S. , Marshall D. R. , Hurwitz J. L.
Published: June 2005

We find that a single respiratory administration of replicationally inactivated influenza A viral particles most often elicits a waning serum antibody response, as the long‐sustained bone marrow antiviral plasma cell populations characteristically induced by viral infection are lacking, though antiviral plasma cells at other sites may occasionally persist for a long time. To determine whether this alteration in the pattern of the B‐cell response is a reflection of the nature of T‐helper (Th) priming, we simultaneously primed B cells with inactivated influenza A/PR8(H1N1) and Th cells with infectious A/x31(H3N2). We show that Th cells cross‐react extensively between these two viruses, although the antibody response to viral envelope glycoproteins is completely non‐cross‐reactive. Th cells primed by infectious A/x31 have little impact on the antibody response specifically elicted from naïve B cells by inactivated A/PR8 viruses, suggesting that the characteristic vigour of the antibody response to influenza viral infection depends on the direct interaction of antiviral B cells with virally infected dendritic cells. Memory B cells primed by inactivated influenza viral particles however, respond rapidly to secondary challenge with live or inactivated viruses, promptly populating bone marrow with antiviral plasma cells. Moreover, Th cells primed by previous live A/x31 viral challenge alter the pattern of the response of naïve B cells to live A/PR8 challenge by accelerating the appearance of anti‐H1/N1 plasma cells in bone marrow, eliminating the early spike of anti‐H1/N1 plasma cells in the mediastinal node, and generally diminishing the magnitude of the lymph node response. Inactivated A/PR8 and infectious A/x31 are both effective vaccines against A/PR8 infection, as mice preimmunized with either vaccine exhibit much more rapid viral clearance from the lung after infectious A/PR8 challenge. In fact, even when given during a course of anti‐CD8 treatment to preempt cross‐reactive cytotoxic T cells, live A/x31 is a more effective vaccine against A/PR8 infection than is inactivated A/PR8 itself.
Mobile Classification in Microarray Experiments
Authors: Dozmorov I. M. , Centola M. , Knowlton N. , Tang Y.
Published: June 2005

In a homogeneous group of samples, there are genes whose expression variations can be attributed to factors other than experimental errors. These factors can include natural biological oscillations or metabolic processes. These genes are rarely classified as ‘interesting’ based on their variability profile. However, their dynamic behaviour can tease out important clues about naturally occurring biological processes in the organism under study and can be used for group classification. Dynamical discriminate function analysis was developed on the concept that stable classification parameters (roots) can be derived from highly variable gene‐expression data. Stability of these combinations implies a strongly compensatory relationship that may divulge functional interconnections.
Induction of Systemic Antitumour Resistance with Targeted Polymers
Authors: Rihova B. , Strohalm J. , Kovar M. , Mrkvan T. , Subr V. , Hovorka O. , Sirova M. , Rozprimova L. , Kubackova K. , Ulbrich K.
Published: June 2005

Conjugates based on N‐(2‐hydroxypropyl)methacrylamide (HPMA) represent a new generation of antibody‐targeted polymeric anticancer drugs with both cytotoxic and immunoprotecting/immunomobilizing activity. 20–90% of mice that are cured of EL4 mouse T‐cell lymphoma, BCL1 mouse B‐cell leukaemia and 38C13 mouse B‐cell lymphoma by injection of doxorubicin‐HPMA conjugate develop a long‐lasting memory and systemic antitumour resistance. It is suggested that the main activity of the polymeric drug, directly after application is – due to the high level of the drug – of cytotoxic and cytostatic nature. Thereafter, long‐term conjugates persist at low concentration in the circulation, which are capable of mobilizing the defence mechanisms of the host. Until now, seven patients with generalized carcinoma were treated with doxorubicin‐HPMA–human‐Ig conjugate. Disease stabilization, lasting from 6 to more than 18 months, was recorded.
Coding Joint Diversity in Mature and Immature B‐Cell Lines
Authors: Yuan S. W. , Agard E. A. , Larijani M. , Wu G. E.
Published: June 2005

Antigen receptor gene rearrangement is regulated by many factors in B and T lymphocytes. The sequences of the gene segments themselves, their associated recombination signal sequences (RSS), expression of the RAG genes and the chromatin accessibility of the particular gene segments to be rearranged all influence the outcome of recombination and thus antigen receptor diversity. In the present study, we have evaluated the effect of variations in RAG activity level on the junctional diversity of coding joint sequences. Using the pre‐B‐like 204‐1‐8 and the mature B DR3 cell lines under different transfection conditions, we were able to investigate recombination activity levels that varied 100‐fold. We evaluated the sequences of the coding joints for junctional diversity resulting from nucleotide addition or deletion. Surprisingly, we found that the sequence of coding joints of these recombinants did not exhibit significant variation despite the large difference in recombination frequency. Our results indicate that the fidelity of the joining phase of V(D)J recombination is not jeopardized by varying RAG activity.
Malaria infection among pregnant women attending antenatal clinics in six Rwandan districts
Authors: Geertruyden Jean‐Pierre Van , Ntakirutimana Dorothee , Erhart Annette , Rwagacondo Claude , Kabano Augustin , D'Alessandro Umberto
Published: June 2005

Objectives  The aim of the study was to assess the knowledge, attitude and practices of pregnant women towards malaria and their association with malaria morbidity.

Methods  Cross‐sectional malaria survey of 1432 pregnant women attending six health centres, each of them situated in a specific health district in Rwanda from September to October 2002.

Results  The overall prevalence of malaria infection was 13.6% and all infections but two were caused by Plasmodium falciparum. The six health districts were significantly different in terms of malaria prevalence, which varied between 11.5% and 15.4% in four and was <5% in the other two districts. The prevalence of anaemia and splenomegaly mirrored that of malaria infection. In three districts, the prevalence of infection was significantly higher in primigravidae than in secundigravidae and multigravidae (P = 0.01), while in two others it did not vary with parity. Bed net use was low – only 13.1% of the women had at least one bed net at home and 8.3% of them slept under it – and significantly different between districts. Most women knew that malaria might have serious consequences for their pregnancy and that insecticide‐treated bed nets are useful for malaria prevention. However, the bed net market price [1525 Rwandan Francs (RFr), approximately 1.6€] was much higher than that considered as affordable and acceptable (389 RFr, approximately 0.3€).

Conclusion  Malaria in pregnancy is a major problem in Rwanda, even in the districts of low transmission. Bed net use among pregnant women is low. The option of providing free insecticide‐treated bed nets to pregnant women should be explored and possibly implemented; it could rapidly increase bed net use and earlier attendance to antenatal clinics with clear benefits for the women's health.
Creutzfeldt–Jakob disease in Kenya
Authors: Adam A. M. , Akuku O.
Published: June 2005

Objective  To study the pattern of occurrence of Creutzfeldt–Jakob disease (CJD) in Kenya.

Study design  Prospective, cross‐sectional, descriptive study of clinical, encephalographic and natural history of CJD, backed by histology in as many patients as possible.

Methods  Consecutive patients presenting with the criteria laid down by WHO expert committee for diagnosis of CJD were recruited between January 1990 and May 2004. We analysed the clinical features and electroencephalography of all participants and took brain biopsies from four patients.

Results  There were four definite, seven probable and two possible cases. The electroencephalographic and histological features were typical of sporadic CJD.

Conclusion  Sporadic CJD occurs in Kenya and the clinical, encephalographic and histological features were no different to those described elsewhere. Although we did not see variant, hereditary and iatrogenic forms of CJD, neurologists should not exclude these in making diagnoses.
Age‐dependent effect of plasma nitric oxide on parasite density in Ghanaian children with severe malaria
Authors: Cramer Jakob P. , Nüssler Andreas K. , Ehrhardt Stephan , Burkhardt Jana , Otchwemah Rowland N. , Zanger Philipp , Dietz Ekkehart , Gellert Sabine , Bienzle Ulrich , Mockenhaupt Frank P.
Published: June 2005

Nitric oxide (NO) has toxic properties against Plasmodium falciparum. While high blood levels have been associated with protection against severe malarial disease, they may also contribute to the pathophysiology of cerebral malaria and severe anaemia. Promoter variants in the inducible nitric oxide synthase (iNOS) gene have been shown to influence NO concentrations and disease manifestation. However, findings are conflicting. We examined associations of plasma NO metabolites (NOx) with symptoms of severe malaria, particularly malarial anaemia and cerebral malaria, and with iNOS promoter variants. In 210 Ghanaian children with severe malaria, we measured plasma nitrite, nitrate, and S‐nitrosothiol, and genotyped the iNOS promoter variants −954G→C, −1173C→T, and the −2.5 kb (CCTTT)n microsatellite. NOx levels decreased with age. In young children (<24 months), high NOx was associated with reduced parasite density. This was not seen in patients of 24–48 months of age and reversed in older children. Subgroup analysis revealed that in children with severe anaemia but without cerebral involvement (prostration, impaired consciousness, convulsions), high NOx levels correlated with low parasitaemia (P = 0.02). In these children, elevated NOx levels were also associated with the iNOS−954C→T/(CCTTT)8 haplotype (P = 0.03). No association between NOx or iNOS genotypes and cerebral malaria was observed. Our findings suggest that in young children with severe malaria NOx reduces parasitaemia. This effect wanes at higher ages and may reflect a predominance of unspecific immune responses to infection in early childhood. This finding may have importance for the understanding of associations between iNOS variants and severe malaria in regions of differing disease manifestation.
From the Old World to the New World: an ecologic study of population susceptibility to HIV infection
Authors: Pepin Jacques
Published: June 2005

It remains unclear why the global distribution of human immunodeficiency virus (HIV), between and within continents, is so heterogeneous. This ecologic study of 34 populations of the Americas explored the hypothesis that populations differ in their intrinsic, biological susceptibility to HIV which, together with exposure, might determine the ultimate ‘mature’ prevalence. If true, national HIV prevalence in populations of the Americas should be predictable from each country's ethnic mosaic, inter‐racial admixture and HIV prevalence in regions of Africa, Europe and Asia from where their ancestors migrated. For each country, the adult population (15–49 years) was multiplied by the proportion corresponding to each ethnic group by HIV prevalence in the country/region of origin of each group, yielding the predicted prevalences, which were then compared with observed prevalences documented by UNAIDS for 2001. Predicted and observed HIV prevalences were highly correlated (r = 0.70, P < 0.001). In North America, predicted prevalences were within 0.5% of the observed values, except for African–Americans and African–Canadians. In Central and South America, differences between predicted and observed prevalences were <1.0% except in Honduras and Guyana. Some Caribbean countries had a predicted prevalence identical to the observed one, but there were outliers. Overall, predicted prevalence was 0.93% and observed prevalence 0.64%; two‐thirds of this difference was attributed to Brazil. Although it was not possible to adjust to the confounding effects of sexual behaviour and cofactors of transmission (such as sexually transmitted infections) because of the lack of nationally representative data for each and every country, a number of arguments reviewed in the paper suggest that confounders cannot explain all this association and that differential susceptibility might be an important determinant of steady‐state HIV prevalence.
A randomized clinical trial to compare the efficacy of three treatment regimens along with footcare in the morbidity management of filarial lymphoedema
Authors: Kerketta A. S. , Babu B. V. , Rath K. , Jangid P. K. , Nayak A. N. , Kar S. K.
Published: June 2005

The progression of lymphoedema to elephantiasis associated with increased incidence of episodic adeno‐lymphangitis (ADL) is of great concern, as it causes physical suffering, permanent disability and economic loss to lymphatic filariasis patients. This randomized clinical trial aimed to assess the efficacy in terms of reduction of oedema and ADL frequency of three treatment regimens among lymphoedema patients from Orissa, India. The regimens were: (I) oral penicillin – one tablet of 800 000 U penicillin G potassium twice daily for 12 days‐repeated every 3 months for 1 year; (II) diethylcarbamazine – 6 mg/kg bodyweight for 12 days‐repeated every 3 months for 1 year; and (III) topical antiseptic, i.e. betadine ointment. Foot care was part of all regimens. All three drug regimens are efficacious in reducing oedema and frequency of ADL episodes. Although the efficacy was slightly higher in regimen I, the difference was not significant. About half of all patients had reduced oedema after the 90 days of treatment, with oedema reduction of 75–100% in 20%. A major proportion of the remaining patients had oedema reduced by less than 25%. The proportion of people whose oedema reduced was slightly but not significantly lower in regimen II. anova revealed that lymphoedema reduction varied according to grade; being greatest at grade 1 lymphoedema, followed by grade 2. All three regimens significantly reduced ADL frequency after 1 year of treatment. This may be because of foot care as well as use of antibiotics. The estimated costs of treatment per patient for a period of 3 months are US$2.4, 1.5 and 4.0 respectively for regimen I, II and III. Thus affordable treatments with simple antibiotics and foot care can give substantial relief to the patients and reverse early lymphoedema.
Retention and effectiveness of HIV/AIDS training of traditional healers in far western Nepal
Authors: Poudel Krishna C. , Jimba Masamine , Joshi Anand B. , Poudel‐Tandukar Kalpana , Sharma Mahesh , Wakai Susumu
Published: June 2005

Objective  To evaluate HIV/AIDS training for traditional healers (THs) in far western Nepal.

Methods  We collected data using a structured questionnaire and assessed THs’ knowledge of HIV transmission, misconceptions and preventive measures immediately prior to the initial training conducted from June to December 1999, and then 9–12 months after the training in 2000. We also conducted six focus group discussions (FGD) and assessed THs’ performances after the training. We interviewed 12 key informants about their perceptions towards the trained THs.

Results  THs significantly improved their knowledge of HIV transmission, misconceptions and preventive measures after the training. The FGD and key informant interview results showed that the trained THs provided culturally acceptable HIV/AIDS education to the local people, distributed condoms and played a role in reducing the HIV/AIDS‐related stigma.

Conclusions  THs have a potential to work as key players in HIV/AIDS programmes in Nepal.
Short Communication: Limited influence of haptoglobin genotypes on severe malaria in Ghanaian children
Authors: Bienzle Ulrich , Eggelte Teunis A. , Adjei Lydia A. , Dietz Ekkehart , Ehrhardt Stephan , Cramer Jakob P. , Otchwemah Rowland N. , Mockenhaupt Frank P.
Published: June 2005

Haptoglobin (Hp) polymorphisms in sub‐Saharan Africa have been associated with an increased risk of severe malaria. However, available data are inconclusive. We examined the role of Hp polymorphisms in susceptibility to Plasmodium falciparum infection and to severe malaria in northern Ghana. Three groups each of 290 age and sex‐matched children with severe malaria, children with asymptomatic P. falciparum infection and aparasitaemic healthy controls were studied. Hp typing was based on PCR. In all children, Hp1‐1, Hp2‐1, and Hp2‐2 occurred in 32.4%, 54.1%, and 13.5%, respectively. The prevalence of the Hp genotypes did not differ significantly between groups. However, Hp2 alleles were least common in healthy children (0.379), more frequent in parasitaemic controls (0.402), and most common in severe malaria patients (0.434;  = 3.7; P = 0.06). In matched pair analysis, no Hp genotype increased the risk of severe malaria. However, using Hp1‐1 as a reference, children with Hp2‐2 exhibited a slightly increased risk of severe malaria (odds ratio, 1.6; P = 0.04). These results indicate that Hp polymorhisms may have a rather limited influence on the development of severe malaria.
Community‐based surveillance: a pilot study from rural Cambodia
Authors: Oum Sophal , Chandramohan Daniel , Cairncross Sandy
Published: June 2005

Objective  This study seeks to assess the performance of a community‐based surveillance system (CBSS), developed and implemented in seven rural communes in Cambodia from 2000 to 2002 to provide timely and representative information on major health problems and life events, and so permit rapid and effective control of outbreaks and communicable diseases in general.

Methods  Lay people were trained as Village Health Volunteers (VHVs) to report suspected outbreaks, important infectious diseases, and vital events occurring in their communities to local health staff who analysed the data and gave feedback to the volunteers during their monthly meetings.

Results  Over 2 years of its implementation, the system was able to detect outbreaks early, regularly monitor communicable disease trends, and to provide continuously updated information on pregnancies, births and deaths in the rural areas. In addition, the system triggered effective responses from both health staff and VHVs for disease control and prevention and in outbreaks.

Conclusion  A CBSS can successfully fill the gaps of the current health facility‐based disease surveillance system in the rapid detection of outbreaks, in the effective monitoring of communicable diseases, and in the notification of vital events in rural Cambodia. Its replication or adaptation for use in other rural areas in Cambodia and in other developing countries is likely to be beneficial and cost‐effective.
Rapid assessment of Schistosoma mansoni: the validity, applicability and cost‐effectiveness of the Lot Quality Assurance Sampling method in Uganda
Authors: Brooker Simon , Kabatereine Narcis B. , Myatt Mark , Russell Stothard J. , Fenwick Alan
Published: June 2005

Rapid and accurate identification of communities at highest risk of morbidity from schistosomiasis is key for sustainable control. Although school questionnaires can effectively and inexpensively identify communities with a high prevalence of Schistosoma haematobium, parasitological screening remains the preferred option for S. mansoni. To help reduce screening costs, we investigated the validity of Lot Quality Assurance Sampling (LQAS) in classifying schools according to categories of S. mansoni prevalence in Uganda, and explored its applicability and cost‐effectiveness. First, we evaluated several sampling plans using computer simulation and then field tested one sampling plan in 34 schools in Uganda. Finally, cost‐effectiveness of different screening and control strategies (including mass treatment without prior screening) was determined, and sensitivity analysis undertaken to assess the effect of infection levels and treatment costs. In identifying schools with prevalences ≥50%, computer simulations showed that LQAS had high levels of sensitivity and specificity (>90%) at sample sizes <20. The method also provides an ability to classify communities into three prevalence categories. Field testing showed that LQAS where 15 children were sampled had excellent diagnostic performance (sensitivity: 100%, specificity: 96.4%, positive predictive value: 85.7% and negative predictive value: 92.3%). Screening using LQAS was more cost‐effective than mass treating all schools (US$218 vs. US$482/high prevalence school treated). Threshold analysis indicated that parasitological screening and mass treatment would become equivalent for settings where prevalence ≥50% in 75% of schools and for treatment costs of US$0.19 per schoolchild. We conclude that, in Uganda, LQAS provides a rapid, valid and cost‐effective method for guiding decision makers in allocating finite resources for the control of schistosomiasis.
Analysis of Mycelial Growth Rates and RAPD‐PCR Profiles in a Population of Gaeumannomyces graminis var. tritici Originating from Wheat Plants Grown from Fungicide‐treated Seed
Authors: Weber Z. , Irzykowska L. , Bocianowski J.
Published: June 2005

Linear mycelial growth rates of 70 isolates of Gaeumannomyces graminis var. tritici on agar medium amended or unamended with the fungicide silthiofam were not correlated. Mycelial growth rate was not influenced by the fungicide applied to the seed of the plants from, which the isolates originated. DNA polymorphism determined by randomly amplified polymorphic DNA (RAPD) polymerase chain reaction was used to assess genetic variation among isolates. Thirty RAPD markers generated with five arbitrary 10‐mer primers revealed DNA polymorphism suitable for assessing variability in this fungal population. Cluster analysis of RAPD data identified two groups at the 54% similarity level. There was a significant relationship between the presence of 11 markers and sensitivity to silthiofam.
Use of β‐Glucuronidase Activity to Quantify the Growth of Fusarium oxysporum f. sp. radicis‐lycopersici during Infection of Tomato
Authors: Papadopoulou K. K. , Kavroulakis N. , Tourn M. , Aggelou I.
Published: June 2005

The β‐glucuronidase (gus) reporter gene was integrated into the phytopathogenic fungus Fusarium oxysporum f. sp. radicis‐lycopersici (FORL) in a co‐transformation experiment using the hygromycin B resistance (hph) gene as selective marker, which resulted in the generation of 10 mitotically stable transformants. One transformant, F30, was selected based on the results of prior detailed characterization of the 10 transformants for growth rate, conidia production and pathogenicity in comparison with the wild‐type strain. A strong positive correlation was found between GUS activity and accumulated biomass of in vitro‐grown fungus and therefore GUS activity was used to study fungal growth quantitatively in two tomato lines. Although a parallel increase in lesion development and GUS activity was noted for both tomato lines, a correlation between the GUS activity and disease progression was not always possible. Interestingly, the levels of GUS activity obtained for the more resistant line were higher than those obtained for the susceptible line, indicating that disease progression in tomato caused by FORL may not be related only to the amount of fungal biomass within the root tissue.
First Report of AG‐A of Binucleate Rhizoctonia in China, Pathogenic to Soya Bean, Pea, Snap Bean and Pak Choy
Authors: Yang G. H. , Chen H. R. , Naito S. , Ogoshi A. , Deng Y. L.
Published: June 2005

Twenty binucleate Rhizoctonia (BNR) isolates were collected from roots of soya bean, pea, snap bean and pak choy with root rot symptoms in Yunnan Province, China. Chinese isolates anastomosed with the tester isolate of anastomosis group‐A (AG‐A; C‐517) with a high C2 fusion rate (>70%). Chinese isolates were pathogenic to soya bean, pea, snap bean and pak choy and had 97% similarity sequence of 5.8S rDNA‐internal transcribed spacer with AG‐A tester isolates SN‐2 and C‐662. When compared with other groups, AG‐Ba and AG‐Bb, Chinese isolates showed 77% sequence similarity. These results show that Chinese isolates belong to AG‐A of BNR. Growth rate, hyphal diameter, cultural characteristics and pathogenicity of the Chinese isolates differed significantly from the tester isolate of AG‐A. This is the first report on AG‐A in China.
Pathogenic Specialization of Puccinia triticina in Andalusia from 1998 to 2000
Authors: Martínez F. , Sillero J. C. , Rubiales D.
Published: June 2005

Wheat leaf rust (Puccinia triticina) is becoming a serious concern in Spanish wheat, especially on durum wheat where acreage has enormously increased. Host resistance is the preferred method of disease control, but the virulence spectrum of the leaf rust population in Spain is currently unknown. In order to deploy effective Lr genes, this study was conducted to characterize the virulence spectrum of leaf rust in Andalusia (Spain). Isolates were obtained from surveys of wheat fields across Andalusia from 1998 to 2000. From 56 isolates phenotyped, 35 pathotypes were identified. Virulence to Lr10, Lr11, Lr14a, Lr14b and Lr18 was high (>96%), while virulence to Lr9 and Lr24 were not found. None of the isolates collected from durum wheat were virulent to Lr1, Lr3, Lr3ka, Lr3bg, Lr15, Lr16 and Lr17, while many of the isolates collected on bread wheat showed virulence on these genes, indicating a certain specialization in the leaf rust infecting durum wheat. Population dynamics of current wheat leaf rust pathotypes in terms of mutation and migration are discussed.
The Effect of Downy and Powdery Mildew on Grapevine (Vitis vinifera L.) Leaf Gas Exchange
Authors: Moriondo M. , Orlandini S. , Giuntoli A. , Bindi M.
Published: June 2005

The impact of powdery (Uncinula necator) and downy mildew (Plasmopara viticola) on grapevine leaf gas exchange was analysed. Gas exchange measurements (assimilation A, transpiration E, stomatal conductance gs, intercellular concentration of CO2Ci) were made on three different leaf materials: (i) healthy tissue of diseased leaves, (ii) infected tissue of diseased leaves, (iii) healthy tissue of healthy leaves (control treatment). Using the same source of leaf tissue, photosynthetic pigment concentration (chlorophyll a, b) and fluorescence levels (minimal fluorescence F0, maximal fluorescence Fm and the optimal quantum yield [Fm − F0]/Fm) were determined to explain the mechanism of action of the two diseases on leaf assimilation. The results indicated that powdery and downy mildew reduced the assimilation rates, not only through a reduction in green leaf area (visual lesions), but also through an influence on gas exchange of the remaining green leaf tissues, determining a ‘virtual lesion’. The ratios between virtual and visual lesions were higher in powdery mildewed leaves than in the downy mildewed leaves. The photosynthetic fluorescence level (Fv/Fm) was affected by neither of the two pathogens. The reduction in intercellular concentration of CO2 and photosynthetic pigment may explain the lower assimilation rates in the healthy tissues of powdery and downy mildewed leaves respectively.
Fate of Clavibacter michiganensis ssp. sepedonicus, the Causal Organism of Bacterial Ring Rot of Potato, in Weeds and Field Crops
Authors: van der Wolf J. M. , van Beckhoven J. R. C. M. , Hukkanen A. , Karjalainen R. , Müller P.
Published: June 2005

Crops and weeds were tested for their ability to host Clavibacter michiganensis ssp. sepedonicus (Cms), the causal agent of bacterial ring rot in potato. Ten crops grown in rotation with potato in Europe, namely maize, wheat, barley, oat, bush bean, broad bean, rape, pea and onion and five cultivars of sugar beet were tested by stem and root inoculation. About 6–8 weeks after inoculation, Cms could be detected in most crops except onion and sugar beet, in larger numbers in stems (105–106 cells/g of tissue) than in roots (≤103 cells/g of tissue) in immunofluorescence cell‐staining (IF). Cms was successfully re‐isolated only from IF‐positive stem samples of maize, bush bean, broad bean, rape and pea, but not from roots. Twelve solanaceous weeds and 13 other weeds, most commonly found in potato fields in Europe, were tested in IF as hosts of Cms by stem and root inoculations. Only in Solanum rostratum, a weed present in northern America, Cms persisted in high numbers (108 cells/g tissue) in stems and leaves, where it caused symptoms. In the other solanaceous weeds, Cms persisted at low numbers (approximately 105 cells/g of tissue) in stems but less so in roots. The bacteria could be frequently re‐isolated from stem but not from root tissues. In 2 consecutive years, plants from 14 different weed species were collected from Cms‐contaminated potato field plots and tested for the presence of Cms by dilution plating or immunofluorescence colony‐staining (IFC), and by AmpliDet RNA, a nucleic acid‐based amplification method. Cms was detected in roots but not in stems of Elymus repens plants growing through rotten potato tubers, and in some Viola arvensis and Stellaria media plants, where they were detected both in stems and roots, but more frequently by AmpliDet RNA than by IFC.
Fusarium oxysporum f. sp. radicis‐lycopersici can Induce Systemic Resistance in Barley Against Powdery Mildew
Authors: Nelson H. E.
Published: June 2005

Drench inoculation of the undisturbed roots of barley seedlings with Fusarium oxysporum f. sp. radicis‐lycopersici (FORL) significantly reduced the primary infection frequency of Blumeria graminis f. sp. hordei (BGH) on the first leaves. The length of secondary hyphae and subsequent conidial production of BGH were also found to be significantly reduced by preinoculation with FORL. The reduction in infection frequency was observed as early as 48 h after inducer treatment, namely when plants were challenge‐inoculated immediately following inoculation with FORL. The induced resistance continued up to 16 days after treatment as indicated by the reduction in infection frequency, up to 22 days after treatment when evaluated as a reduction in the length of secondary hyphae, and up to 35 days after treatment when evaluated as a reduction in conidial production. Characteristics of FORL that may explain its success as an inducer of resistance against barley powdery mildew are discussed.
Growth and photosynthetic rates of Chlamydomonas plethora and Nitzschia frustula cultures isolated from Kuwait Bay, Arabian Gulf, and their potential as live algal food for tropical mariculture
Authors: Subba Rao Durvasula Venkata , Pan Youlian , Al‐Yamani Faiza
Published: June 2005

With a view to utilize local algae as food organisms in mariculture, the green alga Chlamydomonas plethora and the diatom Nitzschia frustula were isolated and studied from the unique coastal waters arid zone off Kuwait. Batch cultures of C. plethora and N. frustula had maximum division rates (μmax) of 2.5 and 3.4 day−1, respectively. Cultures grown for 36 h yielded comparable growth rates. Photosynthesis‐irradiance relationships in cultures harvested at various phases of growth showed that cultures attained log phase after 1‐day growth and yielded the highest assimilation numbers (P: μg C [μg Chl a]−1 h−1): 22.8 for C. plethora and 18.1 for N. frustula. Their initial slopes (αB: ng C [μg Chl a]−1 h−1 [μmol m−2 s−1]−1 were also the highest observed so far: 79.5 for C. plethora and 39.6 for N. frustula. Photoinhibition was low. Compared with these, assimilation numbers in senescent cultures of 20‐day growth were <8% of the maximum for both species, and the initial slope decreased to 17 and 13% in C. plethora and N. frustula, respectively. Two polyunsaturated fatty acids (20:5n‐3 eicosapentaenoic acid and 22:6n‐3 docosahexaenoic acid) that are essential in many marine animal diets constituted up to 24% and 1.9% of the total fatty acids, respectively. Of the two algae, N. frustula contained higher levels of 16:1n‐7, 20:5n‐3 and comparatively low levels of 22:6n‐3 fatty acids. Due to its rapid growth, high photosynthetic rate and presence of the amino acids leucine, lysine, glutamic acid and arginine N. frustula has good potential as a feed organism in mariculture applications. The capacity of these algae to produce a wide range of size groups (nano and net plankton) is an additional bonus for mariculture operations.
Use of point‐of‐care online clinical evidence by junior and senior doctors in New South Wales public hospitals
Authors: Westbrook J. I. , Gosling A. S. , Westbrook M. T.
Published: June 2005

Abstract

Background: The Clinical Information Access Program (CIAP), an online evidence retrieval system, provides NSW health professionals in public hospitals with 24 h access to information supporting evidence‐based practice.

Aim: To assess the frequency and type of CIAP usage by senior and junior medical staff and doctors’ attitudes to CIAP.

Methods: A convenience sample of 25% of doctors from 65 randomly selected public hospitals completed a survey. Junior (n = 392) and senior (n = 684) doctors’ responses were compared using χ2 analyses and t‐tests.

Results: Most doctors had heard of CIAP (71.8%) and 60.6% had used it. More junior (72.4%) than senior (53.8%) doctors had used CIAP and junior doctors found it easier to use. Of the users 93.5% believed CIAP had the potential to improve patient care; 55.2% had directly experienced this. Most usage (61.5%) occurred at point‐of‐care; 74% of users found all/most of the information they sought and 71.6% found the search time to be ‘good/excellent’. Users had increased their usage in the past year and predicted increased future usage. The most popular databases were Medline and MIMS. Age, access to other evidence, and lack of training, time and computer skills were associated with non‐usage. Junior and senior users differed in 4 of 15 reasons for using CIAP.

Conclusions: CIAP is used and valued by the majority of doctors. Patterns of usage, online experiences and the attitudes toward CIAP of senior doctors who use CIAP are relatively similar to those of junior doctors. (Intern Med J 2005; 35: 399–404)
New therapeutic target in inflammatory disease: macrophage migration inhibitory factor
Authors: Morand E. F.
Published: June 2005

Abstract

The cytokine macrophage migration inhibitory factor (MIF) participates in fundamental events in innate and adaptive immunity. The profile of activities of MIF in vivo and in vitro is strongly suggestive of a role for MIF in the pathogenesis of many inflammatory diseases, including rheumatoid arthritis (RA), and hence antagonism of MIF is suggested as a potential therapeutic strategy in inflammatory disease. The best developed case for therapeutic antagonism of MIF is in RA. In RA, MIF is abundantly expressed in serum and synovial tissue. MIF induces synovial expression of key pro‐inflammatory genes, regulates the function of endothelial cells and leucocytes, and is implicated in the control of synoviocyte proliferation and apoptosis via direct effects on the expression of the tumour suppressor protein p53. In animal models of RA, anti‐MIF antibodies or genetic MIF deficiency are associated with significant inhibition of disease. A similar case has been made, for example using MIF‐deficient mice, in models of atheroma, colitis, multiple sclerosis and other inflammatory diseases. The relationship with p53 also means MIF may be important in the link between inflammatory disease and cancer, such as is seen in RA or colitis. MIF also has a unique relationship with glucocorticoids, in that despite antagonizing their effects, the expression of MIF is in fact induced by glucocorticoids. Thus, MIF functions as a physiological counter‐regulator of the anti‐inflammatory effects of glucocorticoids. This may be entrained by selective activation of mitogen‐activated protein kinases rather than nuclear factor kappa B. Therapeutic MIF antagonism may therefore provide a specific means of ‘steroid sparing’. Exploitation of antibody, soluble receptor or small molecule technologies may soon lead to the ability to test in the clinic the importance of MIF in human inflammatory diseases. (Intern Med J 2005; 35: 419–426)
Recognition and optimal management of schizophrenia and related psychoses
Authors: Singh B.
Published: June 2005

Abstract

Schizophrenia continues to remain one of the major unsolved conditions of our time, contributing significantly to causes of disability worldwide. Advances in neuroimaging have demonstrated that schizophrenia appears to be primarily a neurodevelopmental disorder. The dopamine theory of schizophrenia continues to hold sway but interest is growing in the role of other neurotransmitters. Genetic linkage studies continue to suggest that specific chromosomes have a role in the aetiology of the condition but the findings are, as yet, inconsistent. A new generation of drug therapies and reforms of the mental health system have meant that it is now possible to treat the majority of those with this condition in the community albeit, in some instances, against their will. The medical complications of both the disorder, the lifestyle changes resulting from the disorder and the new and older medications have come to prominence in recent years. The development of guidelines for treatment has the potential to reduce the variability in clinical practice that currently exists in the management of the condition. (Intern Med J 2005; 35: 413–418)
The innovating region: toward a theory of knowledge‐based regional development
Authors: Etzkowitz Henry , Klofsten Magnus
Published: June 2005

This paper sets forth a model of knowledge‐based regional development conceived as a set of multi‐linear dynamics, based on alternative technological paradigms. Utilizing longitudinal data from a Swedish region, and international comparisons, four stages of development are identified: Inception, Implementation, Consolidation and Renewal. Innovation policy is created ‘bottom‐up’ as an outcome of ‘collective entrepreneurship’ through collaboration among business, government and academic actors – the ‘triple helix’. The key event is the creation of an entrepreneurial university, whether from an existing academic base or a new foundation, which takes initiatives together with government and industry to create a support structure for firm formation and regional growth. The result of these initiatives is a self‐sustaining dynamic in which the role of academia and government appears to recede as industrial actors come to the fore and a lineage of firms is created. Nevertheless, as one technological paradigm is exhausted and another one is needed as the base for new economic activity, the role of academia and government comes to the fore again in creating the conditions for the next wave of innovation.
Disruptive technologies, stakeholders and the innovation value‐added chain: a framework for evaluating radical technology development
Authors: Hall Jeremy K. , Martin Michael J. C.
Published: June 2005

Contemporary frameworks for evaluating technological innovations contend that innovative success is dependent upon the ability of firms to acquire and assimilate new knowledge without disrupting value chain members such as suppliers, customers and complementary innovators. These frameworks, however, provide little advice on how to deal with radical, controversial innovations that may also introduce new undesirable environmental, health, and social side affects. In addition to technological, commercial and organisational uncertainties, the developers of such technology typically must resolve social uncertainties, a particularly difficult activity because of the added complexities and often conflicting and/or difficult‐to‐reconcile concerns from secondary stakeholders. Attempts must be made to address the potential unintended and unforeseen consequences of the technology, as well as its potential benefits, if it is to be successfully applied. Using Monsanto's development of agricultural biotechnology as an illustration, we suggest an evaluation framework that incorporates stakeholder theory, innovation management concepts and Popper's evolutionary learning methodology of science and its extension to social issues.
Risks in new product development: devising a reference tool
Authors: Keizer Jimme A. , Vos Jan‐Peter , Halman Johannes I.M.
Published: June 2005

This paper describes the development and applicability of a risk reference framework (RRF) for diagnosing risks in technological breakthrough projects. In contrast to existing risk identification strategies, the RRF centers on an integral perspective on risk (i.e. business, technological and organizational) and the assessment of risks in ongoing projects. The resulting RRF consists of 12 main risk categories and 142 connected critical innovation issues and has been developed for a globally operating company in the fast‐moving consumer goods industry. Our analyses show that to some extent different project members identified the same risks and that saturation occurred in the number of new risk‐issues brought to light. We conclude that the success of breakthrough innovation projects improves through formal risk‐assessment.
Content validation of a measure of R&D effectiveness
Authors: García‐Valderrama Teresa , Mulero‐Mendigorri Eva
Published: June 2005

The overall purpose of this paper is to analyse the content validity of a tool for measuring research and development (R&D) effectiveness in industry using an approach known as scale or construct validation.

Since a large number of indicators is needed in order to measure this concept, and it is often difficult to find qualitative measures that would provide more information than quantitative measures or purely numerical magnitudes, we have constructed a scale that enables us to create a multiindicator to measure R&D inputs, processes, outputs and results. This multiindicator also enables us to group together all the relevant data obtained from the R&D management literature, which we then validate by consulting the opinion of experts from two firms that are very active in R&D and we have consulted two more nationally recognized Spanish researchers on R&D.