bluuebunny/crossref_metadata_2025 huggingface dataset:
Recovery of gastric function after Helicobacter pylori eradication in subjects with body atrophic gastritis: Prospective 4‐year study
Authors: DI MARIO FRANCESCO , MOUSSA ALI M , DAL BÒ NADIA , CARUANA PIETRO , PILOTTO ALBERTO , CAVALLARO LUCAS G , CAVESTRO GIULIA M , IORI VERONICA , MERLI ROBERTA , FRANZÉ ANGELO , RUGGE MASSIMO
Published: October 2005

Background:  The relationship between Helicobacter pylori (H. pylori) eradication and atrophic changes in the gastric mucosa has not yet been fully defined. Although studies report a partial restoration of serum pepsinogen I (sPGI) levels after eradication, it is not clear if this finding reflects gastric mucosal healing on a morphological level.

Aim:  To assess alterations in gastric function after H. pylori eradication on moderate/severe body atrophic gastritis by determination of sPGI levels.

Methods:  Twenty‐three dyspeptic patients, selected from 284 consecutive H. pylori positive patients, with histological features of moderate/severe body atrophic gastritis and sPGI < 25 µg/L (11 men, mean age: 51.8 years, range: 29–79 years), underwent an upper gastrointestinal endoscopy with gastric biopsies and sPGI determination at baseline. All patients underwent eradication therapy. Serum pepsinogen I was measured again after 6 months, and at 1, 2, 3 and 4 years after eradication therapy.

Results:  Mean sPGI levels prior to eradication were 11.9 µg/L (range: 4–23 µg/L). Six months after eradication therapy, mean sPGI levels significantly increased to 17.4 µg/L (P = 0.04). At the completion of the study, 4 years after eradication, sPGI levels increased from 17.4 to 32.7 µg/L (P = 0.01). A significant progressive increase in sPGI levels was observed from 6 months to 1 year (17.4 to 23.9 µg/L) and from 1 to 2 years (23.9 to 26.0 µg/L, P = 0.01). Serum pepsinogen I levels higher than the cut‐off value of 25 µg/L were observed at various time‐points: 6.3% of patients at 6 months (1/16), 33.3% (5/15) at 1 year, 50% (7/14) at 24 months, 66.7% (6/9) at 36 months and 87.5% (7/8) at 4 years.

Conclusion:  After H. pylori eradication, subjects with body atrophic gastritis showed long‐term improvement of physiological gastric function, reflected by significantly and continually increasing sPGI levels over a 4‐year period.
Bax and Bcl‐2 protein expression in gastric precancerous lesions: Immunohistochemical study
Authors: ANAGNOSTOPOULOS GEORGE K , STEFANOU DIMITRIOS , ARKOUMANI EVDOKIA , SAKORAFAS GEORGE , PAVLAKIS GEORGE , ARVANITIDIS DIMITRIOS , TSIANOS EPAMEINONDAS , AGNANTIS NIKI J
Published: October 2005

Background and Aims:  Bcl‐2 protein prolongs cell survival in the face of classical apoptotic stimuli, and is considered to be a suppressor of apoptosis. Bax plays a key role in apoptosis by accelerating cell death after an apoptotic stimulus. The aim of our study was to determine the roles of the Bax proapoptotic gene and the Bcl‐2 antiapoptotic gene in the carcinogenesis of gastric cancer.

Methods:  One hundred and forty‐five gastric biopsy specimens of chronic gastritis, atrophic gastritis, intestinal metaplasia and gastric dysplasia were studied. Using immunohistochemical methods, Bax and Bcl‐2 protein expression was observed.

Results:  Bax was expressed in epithelial cells in all cases of chronic gastritis. Bax was not detected in 26% of specimens of atrophic gastritis. As intestinal metaplasia develops, Bax is further suppressed. In biopsy samples with dysplasia, Bax expression was demonstrated only in 12% of biopsy samples. Although Bcl‐2 protein was not detected in chronic gastritis, aberrant expression was found in gastric epithelial intestinal metaplasia and dysplasia.

Conclusions:  The suppression of Bax and overexpression of Bcl‐2 protein is an early event in gastric tumorigenesis, before gastric dysplastic changes occur.
Psychological implications of hepatitis C virus diagnosis
Authors: GILL MUZAFFAR L , ATIQ MUSLIM , SATTAR SYMA , KHOKHAR NASIR
Published: October 2005

Background and Aims:  Hepatitis C virus (HCV) diagnosis causes significant psychological stress and anxiety. We thought it would be important to illustrate the anxiety caused by HCV diagnosis in patients from the developing world.

Methods:  This study was conducted at the Shifa International Hospital, Islamabad, between February 2004 and April 2004. All patients who were recently diagnosed with HCV (those who tested positive to anti‐HCV and HCV polymerase chain reaction) were given a questionnaire that compared stress due to HCV infection with four other variables, including death of a close family member, divorce, loss of source of income and move to another city. We also analyzed the anxiety level among these patients using the Beck Anxiety Inventory (BAI).

Results:  We studied 98 patients and 100 healthy controls. Thirty‐one (31.63%) patients who were diagnosed with HCV presented only with fatigue. Sixty‐three (64.28%) patients admitted that diagnosis of HCV interfered with their daily life in some way. Among the newly diagnosed cases, 48 (48.97%) patients had moderate to severe anxiety (BAI Class B and C). Multi‐logistic regression analysis showed that anxiety was related to HCV‐related stress (P < 0.002) and self‐perceived severity of disease (P < 0.001). HCV diagnosis was significantly more stressful than divorce (59.87 vs 70.95; P < 0.013), loss of source of income (50.52 vs 70.80; P < 0.001), and a move to another city (28.32 vs 70.80; P < 0.001).

Conclusions:  Diagnosis with HCV is reported to be more stressful than divorce, loss of source of income and a move to another city.
Lymphotoxin‐β production following bile duct ligation: Possible role for Kupffer cells
Authors: LEE CLAIR M , KNIGHT BELINDA , YEOH GEORGE C , RAMM GRANT A , OLYNYK JOHN K
Published: October 2005

Background and Aims:  Lymphotoxin‐β (LT‐β) may play a role in the pathogenesis of chronic liver injury. The aim of this study was to determine in an animal model of bile duct ligation liver injury whether LT‐β expression is induced and whether Kupffer cells are an intrahepatic source of LT‐β.

Methods:  Sprague–Dawley rats were divided into two groups: one group received a single dose of GdCl (a Kupffer cell‐blocking agent, 10 mg/kg i.v.), whereas the other group received saline. One day later, the groups underwent bile duct ligation or a sham operation. Liver tissue was obtained on days 1, 3, 5, and 8 for assessment of Kupffer cell numbers, early fibrogenic events and LT‐β gene expression. Kupffer cells were isolated using pronase/collagenase perfusion and centrifugal elutriation.

Results:  Hepatic LT‐β mRNA expression increased early following bile duct ligation. Pretreatment of bile duct‐ligated animals with GdCl significantly reduced the number of Kupffer cells, delayed the rise in LT‐β expression, but had no effect on fibrogenesis. Recovery of the Kupffer cell population in these animals was accompanied by increased hepatic LT‐β expression. The LT‐β ligand and receptor were expressed by isolated normal Kupffer cells.

Conclusions:  Hepatic LT‐β expression is induced early following bile duct ligation. Kupffer cells may be an intrahepatic source of LT‐β.
Reproductive ecology of the freshwater red alga Batrachospermum delicatulum (Batrachospermales, Rhodophyta) in three tropical streams
Authors: Necchi Orlando , Vis Morgan L.
Published: October 2005

Batrachospermum delicatulum specimens from three stream segments were analyzed from a tropical region in south‐ eastern Brazil (20°18′– 20°49′S, 49°13′– 49°46′W). Physical and chemical parameters and the spatial placement of thalli were investigated along with the reproductive characteristics of the gametophytic phase. Sequence data of the cox 2‐ 3 spacer region was also utilized to evaluate genetic variation in individuals within and among stream segments. Gametophyte occurred under relatively diverse environmental conditions, whereas thalli abundance was weakly or not correlated to environmental variables within the stream segments. All specimens examined were dioecious. The ratio of male/female plants was relatively low (0.5 to 1.3) and male plants tended to occur as clumps (two or three plants together). High reproductive success was observed, as indicated by the occurrence of 100% fertilized (carposporophytic) female plants. This is similar to previous reports for this and other dioecious species, which is remarkable considering the relatively low proportion of male/female plants. Results support the two hypotheses to explain the high reproductive success in dioecious species. The occurrence of male plants in clumps was evidence for a strict spatial relationship (i.e. male plants located in upstream position of female plants in order to release spermatia, which would be carried by eddies through female plants). In contrast, the occurrence of male and female plants adjacent to each other allowed outcrossing among neighboring plants with intermingled male and female branches, which seemed more applicable to some situations (low turbulence habitats). The cox 2‐ 3 spacer region from the 18 individuals sequenced was 376 bp and the DNA sequence was identical with no base pair substitutions. Likewise, a previous study of another Batrachospermum species showed that the same haplotypes were present in all stream segments from the same drainage basin, even though the stream segments were a considerable distance apart. Short distance dispersal either by small birds or waterway connectivity might explain these findings.
Accounting for uncertainty in marine reserve design
Authors: Halpern Benjamin S. , Regan Helen M. , Possingham Hugh P. , McCarthy Michael A.
Published: October 2005

Ecosystems and the species and communities within them are highly complex systems that defy predictions with any degree of certainty. Managing and conserving these systems in the face of uncertainty remains a daunting challenge, particularly with respect to developing networks of marine reserves. Here we review several modelling frameworks that explicitly acknowledge and incorporate uncertainty, and then use these methods to evaluate reserve spacing rules given increasing levels of uncertainty about larval dispersal distances. Our approach finds similar spacing rules as have been proposed elsewhere – roughly 20–200 km – but highlights several advantages provided by uncertainty modelling over more traditional approaches to developing these estimates. In particular, we argue that uncertainty modelling can allow for (1) an evaluation of the risk associated with any decision based on the assumed uncertainty; (2) a method for quantifying the costs and benefits of reducing uncertainty; and (3) a useful tool for communicating to stakeholders the challenges in managing highly uncertain systems. We also argue that incorporating rather than avoiding uncertainty will increase the chances of successfully achieving conservation and management goals.
Tracking carbon from the atmosphere to the rhizosphere
Authors: Olsson Pål A. , Johnson Nancy C.
Published: October 2005

Turnover rates of arbuscular mycorrhizal (AM) fungi may influence storage of soil organic carbon (SOC). We examined the longevity of AM hyphae in monoxenic cultures; and we also used 13C incorporation into signature fatty acids to study C dynamics in a mycorrhizal symbiosis involving Glomus intraradices and Plantago lanceolata. 13C enrichment of signature fatty acids showed rapid transfer of plant assimilates to AM fungi and a gradual release of C from roots to rhizosphere bacteria, but at a much slower rate. Furthermore, most C assimilated by AM fungi remained 32 days after labelling. These findings indicate that 13C labelled fatty acids can be used to track C flux from the atmosphere to the rhizosphere and that retention of C in AM fungal mycelium may contribute significantly to SOC.
Additive and interactive effects of plant genotypic diversity on arthropod communities and plant fitness
Authors: Johnson Marc T. J. , Lajeunesse Marc J. , Agrawal Anurag A.
Published: October 2005

Recent research suggests that genetic diversity in plant populations can shape the diversity and abundance of consumer communities. We tested this hypothesis in a field experiment by manipulating patches of Evening Primrose (Oenothera biennis) to contain one, four or eight plant genotypes. We then surveyed 92 species of naturally colonizing arthropods. Genetically diverse plant patches had 18% more arthropod species, and a greater abundance of omnivorous and predacious arthropods, but not herbivores, compared with monocultures. The effects of genotypic diversity on arthropod communities were due to a combination of interactive and additive effects among genotypes within genetically diverse patches. Greater genetic diversity also led to a selective feedback, as mean genotype fitness was 27% higher in diverse patches than in monocultures. A comparison between our results and the literature reveals that genetic diversity and species diversity can have similar qualitative and quantitative effects on arthropod communities. Our findings also illustrate the benefit of preserving genetic variation to conserve species diversity and interactions within multitrophic communities.
Transfer of endophyte‐origin defensive alkaloids from a grass to a hemiparasitic plant
Authors: Lehtonen Päivi , Helander Marjo , Wink Michael , Sporer Frank , Saikkonen Kari
Published: October 2005

Plants growing in natural environments experience myriad interactions with a diverse assemblage of pathogens, parasites and mutualists. Many of these interactions involve symbiotic bacteria and fungi, but they also include macroparasitic plants. In this study, we investigated the interactions among a host grass (Lolium pratense, ex., Festuca pratensis), its symbiotic endophytic fungus (Neotyphodium uncinatum), a root hemiparasitic plant (Rhinanthus serotinus) of the host grass and a generalist herbivore (aphid Aulacorthum solani) of the hemiparasite. We demonstrate that the hemiparasitic plant acquires defending mycotoxins produced by the endophytic fungus living within their shared host grass. The uptake of defensive mycotoxins from the endophyte‐infected host grass enhances the resistance of the hemiparasitic plant to the generalist aphid herbivore. Endophyte infection increases the performance of the hemiparasitic plant, but reduces the growth of the host grass. In other words, the mutualistic endophytic fungus becomes parasitic in the presence of the hemiparasitic plant. Our results suggest that the outcomes of grass–endophyte interactions are conditional on the complexity of community‐level interactions; thus, the outcome of multispecies interactions may not be predictable from pair‐wise combinations of species.
Effects of Suction on the Nonstationary Lower Branch Modes of a Compressible Boundary Layer Flow Due to a Rotating Disk
Authors: Turkyilmazoglu M.
Published: October 2005

In this paper, suction and injection effects are investigated theoretically on the structure of the lower branch neutral stability modes of three‐dimensional small disturbances imposed on the compressible boundary layer flow due to a rotating disk. In a recent study [1], it was demonstrated that the short‐wavelength stationary/nonstationary compressible crossflow vortex modes at sufficiently high Reynolds numbers with reasonably small scaled frequencies can be described by an asymptotic expansion procedure as set up in [2] for the incompressible stationary modes, which rigorously takes into account the nonparallel effects. Employing this rational asymptotic technique, it is shown here that the wavenumber and the orientation of the compressible lower branch modes are governed by an eigenrelation that is under the strong influence of a suction/injection parameter , which, when set to zero, the relation turns out to be the one obtained previously by Turkyilmazoglu [1] for zero‐suction compressible modes.

The boundary layer growth contributes in the way of destabilizing all the modes, in particular for the compressible modes, though the wall cooling in the case of suction and the wall insulation and heating in the case of injection are found to persist to the destabilization for the modes in the vicinity of the stationary mode. From a linear stability analysis point of view, suction is found to be stabilizing, whereas injection enhances the instability as compared to the no suction through the surface of the disk. In both cases, positive frequency waves are found to be highly destabilized as compared to the waves having negative frequencies. The findings of the work are also fully supported after a comparison between the numerical results obtained from directly solving the linearized compressible system with a usual parallel flow approximation and the asymptotic compressible data obtained at a high Reynolds number.
Actin‐Based Motility in the Net Slime MouldLabyrinthula: Evidence for the Role of Myosin in Gliding Movement
Authors: PRESTON TERENCE M. , KING CONRAD A.
Published: October 2005

Abstract.In contrast to crawling movement (e.g. in amoebae and tissue cells) the other major class of substratum‐associated motility in eukaryotes, gliding, has received relatively little attention. The net slime moldLabyrinthulaprovides a useful laboratory model for studying this process since it exhibits a particular kind of gliding in its plasmodial stage. Here nucleated spindle cells glide along self‐established cytoplasmic trackways in a predominantly unidirectional manner, at 1–2 μm/s. These trackways, upon which gliding is dependent, are held by filopodial tethers some distance off the well‐developed reticulopodial mesh anchoring the plasmodium onto the substratum. Reflection interference microscopy resolves this matrix in live plasmodia. The axially disposed cytoskeletal elements of the trackways are revealed by rhodamine‐labelled phalloidin to be rich in F‐actin. A weft of peripheral, rapidly extending filopodia (50 μm/min) typifies the expanding regions of the plasmodium. Here spindle cells are recruited before emigrating into newly differentiated trackways. Immunoblotting whole plasmodia or a sucrose‐soluble cytoplasmic extract reveals a single actin‐positive band of Mr 48 kDa. Polyclonal antibodies to two distinct myosin peptide sequences identify a single myosin HC (Mr 96 kDa) in immunoblots. Gliding was reversibly blocked by 10 mM 2,3‐butanedione‐2‐monoxime, a myosin ATPase inhibitor, but it was insensitive to the actin‐binding drugs cytochalasin D and phalloidin. We suggest that the force (>50 pN) for gliding motility results from interaction of myosin molecules, associated with the spindle cells, with trackway F‐actin via the bothrosomes.
The combination of shared family environment and individual‐specific developmental deviance as a cause for treated psychiatric morbidity in children
Authors: Gunther N. , Drukker M. , Feron F. , Korebrits A. , van Os J.
Published: October 2005

Objective:  There is an incomplete understanding of why some children growing up in the same family are in need of treatment for psychiatric morbidity whilst their siblings are not. The present paper examined the possible role of individual‐specific developmental risk factors.

Method:  Three case–control analyses were conducted: i) 80 children referred to the Community Mental Health Centre (cases) and 320 population controls, ii) 68 healthy siblings of cases and 272 population controls, and iii) 80 children and 68 healthy siblings. Measures of development and psychosocial circumstances were obtained from routine, longitudinal, standardized child medical records.

Results:  Given shared family environments, additional presence of delays in speech and motor development contributed most to differential sibling mental health outcomes. In addition, cases displayed both earlier expression and more severe levels of developmental behavioural deviance than their healthy siblings, who in turn had higher levels of behavioural deviance than population controls.

Conclusion:  In siblings sharing a familial risk environment, development of psychiatric morbidity may be canalized through additional individual‐specific developmental exposures.
A prospective study of offspring of women with psychosis: visual dysfunction in early childhood predicts schizophrenia‐spectrum disorders in adulthood
Authors: Schubert E. W. , Henriksson K. M. , McNeil T. F.
Published: October 2005

Objective: Children with visual dysfunction have perinatal, neurological, visual‐perceptual and cognitive abnormalities, similar to schizophrenia patients. We prospectively investigated whether visual dysfunction in childhood selectively predicts adult schizophrenia‐spectrum disorders, and is related to childhood neurological abnormality.

Method: Offspring of mothers with and without a history of psychosis were prospectively assessed with vision tests at 4 years, neurological examinations at 6 years, and interviews for psychiatric disorders at follow‐up (93% effective,n = 166) at 22 years.

Results: In the total sample and high‐risk (HR) offspring, visual dysfunction at 4 years, and its severity, were associated only with schizophrenia‐spectrum disorders in adulthood, and with neurological abnormality at 6 years.

Conclusion: Visual dysfunction at 4 years of age selectively predicts schizophrenia‐spectrum disorders in adulthood among HR offspring, this likely reflecting disturbed neurological development.
Triazine‐based tyrosinase inhibitors identified by chemical genetic screening
Authors: Ni‐Komatsu Li , Leung Jennifer K. , Williams Darren , Min Jaeki , Khersonsky Sonya M. , Chang Young‐Tae , Orlow Seth J.
Published: October 2005

As most of the available depigmenting agents exhibit only modest activity and some exhibit toxicities that lead to adverse side effects after long‐term usage, there remains a need for novel depigmenting agents. Chemical genetic screening was performed on cultured melanocytes to identify novel depigmenting compounds. By screening a tagged‐triazine library, we identified four compounds, TGH11, TGD10, TGD39 and TGJ29, as potent pigmentation inhibitors with IC50 values in the range of 10 μM. These newly identified depigmenting compounds were found to function as reversible inhibitors of tyrosinase, the key enzyme involved in melanin synthesis. Tyrosinase was further confirmed as the cellular target of these compounds by affinity chromatography. Kinetic data suggest that all four compounds act as competitive inhibitors of tyrosinase, most likely competing with l‐3,4‐dihydroxyphenylalanine (l‐DOPA) for binding to the DOPA‐binding site of the enzyme. No effect on levels of tyrosinase protein, processing or trafficking was observed upon treatment of melanocytes with these compounds. Cytotoxicity was not observed with these compounds at concentrations up to 20 μM. Our data suggest that TGH11, TGD10, TGD39 and TGJ29 are novel potent tyrosinase inhibitors with potential beneficial effects in the treatment of cutaneous hyperpigmentation.
Brassica napus L. Homeodomain Leucine‐Zipper Gene BnHB6 Responds to Abiotic and Biotic Stresses
Authors: YU Shun‐Wu , ZHANG Li‐Da , ZUO Kai‐Jing , TANG Dong‐Qin , SUN Xiao‐Fen , TANG Ke‐Xuan
Published: October 2005

Abstract: A homeodomain leucine‐zipper (HD‐Zip) gene BnHB6 (GenBank accession No. AY3 36103) was isolated from oilseed rape (Brassica napus L.) following drought treatment through rapid amplification of cDNA ends (RACE). The full‐length cDNA of BnHB6 was 1611 bp and contained a 936‐bp open reading frame encoding 311 amino acids. Sequence analysis indicated that BnHB6 belonged to the HD‐Zip I subfamily. High‐stringency Southern boltting analysis showed that BnHB6 appeared in rape as a single copy but had homologous genes. Semi‐quantitative reverse transcription‐polymerase chain reaction (RT‐PCR) analysis revealed that BnHB6 was expressed in several tissues tested under control conditions, but that expression was significantly upregulated in shoots by mannitol, NaCl, cold treatment, anaerobic culture, wounding, H2O2, abscisic acid (ABA), and salicylic acid (SA) treatments, but not by ultraviolet treatment. Further RT‐PCR analysis revealed that BnHB6 was a late‐responsive gene, the expression of which was not activated by NaCl, cold treatment, H2O2, ABA, and SA at an early time point (20 min) of treatment in the shoot. However, after a certain period of treatment, the induced expression culminated and then declined until the next peak occurred. Tissue‐specific analysis revealed that BnHB6 was expressed at certain levels in the roots, shoots, and flowers, and the roots were found to respond to the osmotic stimuli more rapidly than shoots to increase the expression of BnHB6. The present study implies that BnHB6 plays a positive role as a regulator of biotic and abiotic stresses on growth during seedling establishment.

(Managing editor: Li‐Hui ZHAO)
Identification of Random Amplified Polymorphic DNA Markers Linked to Sex Determination in Calamus simplicifolius C. F. Wei.
Authors: YANG Hua , GAN Si‐Ming , YIN Huang‐Tian , XU Huang‐Can
Published: October 2005

Abstract: The random amplified polymorphic DNA (RAPD) molecular marker technique was used to determine the sex of Calamus simplicifolius C. F. Wei. In the present study, DNA samples were extracted individually from 10 male and 10 female plants. After a total of 1 040 decamer primers had been tested, an approximate 500‐bp male‐specific DNA fragment was generated with the S1443 primer. It is feasible to identify sex at the early stages of plant life, which is beneficial for improving breeding programs of this dioecious species. In addition, we have obtained a proper RAPD protocol that is useful for other species of rattan.

(Managing editor: Li‐Hui ZHAO)
Functional Analysis of Nodulin‐like Promoter in Transgenic Cotton Plants
Authors: REN Mao‐Zhi , CHEN Quan‐Jia , LI Li , ZHANG Rui , GUO San‐Dui
Published: October 2005

Abstract: For the first time, a nodulin‐like gene promoter was isolated from Gossypium hirsutum L. Guo Y18 by means of inverse PCR. Three plant expression vectors were constructed for functional identification of the promoter. These vectors were different only in promoter regions; three truncations of the nodulin‐like promoter took the place of the CaMV35S promoter in the pBI121 plant expression vector. Then, the three vectors were introduced into cotton plants via the pollen tube pathway. The expression patterns of the gus gene driven by nodulin‐like promoter truncations were investigated in the offspring of transgenic cotton plants. Histochemical GUS staining and fluorescence quantitative analysis were performed to achieve this goal. The results showed that the nodulin‐like promoter was a strong, highly reproductive organ‐specific promoter, which demonstrated a much higher driver activity than the CaMV35S promoter did in cotton reproductive organs, but relatively lower activity in vegetation. Identification of the speciality and strength‐determining regions of the nodulin‐like promoter was also undertaken.

(Managing editor: Li‐Hui ZHAO)
Diversity in the Content of Some Nutritional Components in Husked Seeds of Three Wild Rice Species and Rice Varieties in Yunnan Province of China
Authors: CHENG Zai‐Quan , HUANG Xing‐Qi , ZHANG Yi‐Zheng , QIAN Jun , YANG Ming‐Zhi , WU Cheng‐Jun , LIU Jia‐Fu
Published: October 2005

Abstract: In addition to rice (Oryza sativa L.) cultivars, there are three wild rice species, namely O. rufipogon Griff, O. officinalis Wall and O. granulata Baill, in Yunnan Province, China. Each species has different subtypes and ecological distributions. Yunnan wild rice species are excellent genetic resources for developing new rice cultivars. The nutritional components of the husked seeds of wild rice have not been investigated thus far. Herein, we report on the contents of total protein, starch, amylose, 17 amino acids, and five macro and five trace mineral elements in husked seeds from three wild rice species and six O. sativa cultivars. The mean (±SD) protein content in the husked rice of O. rufipogon, O. officinalis, and O. granulata was (14.5 ± 0.6)%, (16.3 ± 1.1)%, and (15.3 ± 0.5)%, respectively. O. officinalis III originating from Gengma had the highest protein content (19.3%). In contrast, the average protein content of six O. sativa cultivars was only 9.15%. The total content of 17 amino acids of three wild rice species was 30%‐50% higher than that of the six cultivars. Tyrosine, lysine, and valine content in the three wild rice species was 34%‐209% higher than that of the cultivars. However, the difference in total starch content among different O. sativa varieties or types of wild rice species was very small. The average amylose content of O. rufipogon, O. officinalis, and O. granulata was 12.0%, 9.7%, and 11.3%, respectively, much lower than that of the indica and japonica varieties (14.37%‐17.17%) but much higher than that of the glutinous rice cultivars (3.89%). The sulfur, phosphorus, magnesium, zinc, and ferrite content in the three wild rice species was 30%‐158% higher than that of the six cultivars. The considerable difference in some nutritional components among wild rice species and O. sativa cultivars represents a wide biodiversity of Yunnan Oryza species. Based on the results of the present study, it is predicted that some good genetic traits, especially high protein and ideal amylose content, of Yunnan wild rice species may be useful in improving the nutritional value of rice. This is the first report regarding the amino acid, mineral element, protein and amylose content of husked seeds of some Yunnan wild rice species that have important genetic characteristics for rice quality and nutritional value.

(Managing editor: Wei WANG)
Effects of Logging on the Genetic Diversity of Quercus tiaoloshanica Chun et Ko in a Tropical Montane Forest of Hainan Island, Southern China
Authors: ZHENG Jian‐Wei , AN Shu‐Qing , CHEN Lin , LENG Xin , WANG Zhong‐Sheng , XIANG Hua‐Jun
Published: October 2005

Abstract: Quercus tiaoloshanica Chun et Ko, which has a narrow range of distribution, is one of the important endemic species of the tropical montane rain forest on Hainan Island, southern China. Long‐term logging and habitat destruction have resulted in population decline and distribution retreat of Q. tiaoloshanica. To determine the impact of logging on the genetic diversity of Q. tiaoloshanica, the authors investigated the genetic structures using amplified fragment length polymorphism markers in four regenerated stands after logging and in one unlogged stand. Compared with the unlogged stand, the effective number of alleles per locus dropped by 1.0% in selective logging stands and by 2.0% in clear logging stands, corresponding to reductions of 3.8% and 5.2%, respectively, in mean Nei's gene diversity and 2.9% and 3.5%, respectively, in mean Shannon diversity index. No substantial genetic erosion was detected in any of the regenerated stands owing to the high tree density and high heterogeneity of the Q. tiaoloshanica stands investigated. Meanwhile, there was no natural regeneration of the species observed in a Dacrydium pierrei Hickel plantation 700 m away from the regenerated stands, suggesting the limited ability of seed dispersal of Q. tiaoloshanica. Clear logging should be undertaken cautiously because the total number of plant species dropped by 15.2% in the clear‐logged stands compared with the unlogged stand. To conserve the genetic diversity of this species, as well as the plant biodiversity of tropical forests, the habitats of Q. tiaoloshanica should be protected against exploitation in terms of agricultural or other forms of land use, and some mature trees should be preserved as seed sources to maintain an adequate regeneration base for this species in the management of logging.

(Managing editor: Ya‐Qin HAN)
Ectopic Expression of the Pttknl Gene Induces Alterations in the Morphology of the Leaves and Flowers in Petunia hybrida Vilm.
Authors: HU Xin , WU Qing‐Feng , XIE Ya‐Hong , RU Hong , XIE Feng , WANG Xin‐Yu , WANG Chong‐Ying
Published: October 2005

Abstract: A novel knottedl‐like homeobox (knox) gene, Pttknl (Populus tremula tremuloides knottedl), isolated from the cambial region of hybrid aspen, was introduced into Petunia hybrida Vilm. using the leaf‐disc method mediated by Agrobacterium. A series of novel phenotypes was observed in transgenic petunia plants, including the formation of ectopic spikes on the adaxial surface of corollas and small pet als on the abaxial surface of corollas, fusion of floral organs, shortening of corolla midribs, the formation of tumor‐like knots along the midrib on the abaxial surface and serrated lobs of corolla margins, and alterations in pet al color; except for changes in the leaves and plant architecture, RT‐PCR showed that the Pttknl gene was expressed in the leaves of different petunia transgenic plants, whereas no signal was detected in wild‐type plants. The possible function of Pttknl in leaf and flower development is discussed.

(Managing editor: Li‐Hui ZHAO)
Modeling of Aerodynamically Generated Noise From Wind Turbines
Authors: Zhu Wei Jun , Heilskov Nicolai , Shen Wen Zhong , Sørensen Jens Nørkær
Published: October 2005

A semiempirical acoustic generation model based on the work of Brooks, Pope, and Marcolini [NASA Reference Publication 1218 (1989)] has been developed to predict aerodynamic noise from wind turbines. The model consists of dividing the blades of the wind turbine into two-dimensional airfoil sections and predicting the total noise emission as the sum of the contribution from each blade element. Input is the local relative velocities and boundary layer parameters. These quantities are obtained by combining the model with a Blade Element Momentum (BEM) technique to predict local inflow characteristics to the blades. Boundary layer characteristics are determined from two-dimensional computations of airfoils. The model is applied to the Bonus 300 kW wind turbine at a wind speed of 8 m/s. Comparisons of total noise spectra show good agreement with experimental data.
Numerical Simulation of the Aerodynamics of Horizontal Axis Wind Turbines under Yawed Flow Conditions
Authors: Tongchitpakdee Chanin , Benjanirat Sarun , Sankar Lakshmi N.
Published: October 2005

The aerodynamic performance of the National Renewable Energy Laboratory (NREL) Phase VI horizontal axis wind turbine (HAWT) under yawed flow conditions is studied using a three-dimensional unsteady viscous flow analysis. Simulations have been performed for upwind cases at several wind speeds and yaw angles. Results presented include radial distribution of the normal and tangential forces, shaft torque, root flap moment, and surface pressure distributions at selected radial locations. The results are compared with the experimental data for the NREL Phase VI rotor. At low wind speeds (∼7m∕s) where the flow is fully attached, even an algebraic turbulence model based simulation gives good agreement with measurements. When the flow is massively separated (wind speed of 20m∕s or above), many of the computed quantities become insensitive to turbulence and transition model effects, and the calculations show overall agreement with experiments. When the flow is partially separated at wind speed above 15m∕s, encouraging results were obtained with a combination of the Spalart-Allmaras turbulence model and Eppler’s transition model only at high enough wind speeds.
The Effect of Blade Geometry on Blade Stall Characteristics
Authors: van Rooij R. P. J. O. M. , Schepers J. G.
Published: October 2005

The effect of rotation has been investigated with emphasis on the impact of blade geometry on the “correction factor” in stall models. The data used came from field tests and wind tunnel experiments performed by the National Renewable Energy Laboratory and were restricted to the steady-state nonyawed conditions. Three blade layouts were available; a blade with constant chord without twist (phase II), a blade with constant chord and twist (phases III and IV), and a tapered blade with twist (phase VI). Effects due to twist and taper were determined from comparison of c n between the different blade layouts. The formulation of the stall model was rewritten so that the measured c n values could be used without reference to 2D airfoil performance. This enabled a direct comparison of the normal force characteristics between the four blade stations of the selected blade configurations. In particular, the correction term f used in stall models for rotational effects was analyzed. The comparison between the test results with a straight and a twisted blade showed that a relation for twist + pitch is required in f . In addition, a dependency offon the angle-of-attack was identified in the measurements and it is recommended that this dependency be incorporated in the stall models.
Parameter Sensitivities Affecting the Flutter Speed of a MW-Sized Blade
Authors: Lobitz Don W.
Published: October 2005

With the current trend toward larger and larger horizontal axis wind turbines, classical flutter is becoming a more critical issue. Recent studies have indicated that for a single blade turning in still air the flutter speed for a modern 35 m blade occurs at approximately twice its operating speed (2 per rev), whereas for smaller blades (5–9 m), both modern and early designs, the flutter speeds are in the range of 3.5–6 per rev. Scaling studies demonstrate that the per rev flutter speed should not change with scale. Thus, design requirements that change with increasing blade size are producing the concurrent reduction in per rev flutter speeds. In comparison with an early small blade design (5 m blade), flutter computations indicate that the non rotating modes which combine to create the flutter mode change as the blade becomes larger (i.e., for the larger blade the second flapwise mode, as opposed to the first flapwise mode for the smaller blade, combines with the first torsional mode to produce the flutter mode). For the more modern smaller blade design (9 m blade), results show that the non rotating modes that couple are similar to those of the larger blade. For the wings of fixed-wing aircraft, it is common knowledge that judicious selection of certain design parameters can increase the airspeed associated with the onset of flutter. Two parameters, the chordwise location of the center of mass and the ratio of the flapwise natural frequency to the torsional natural frequency, are especially significant. In this paper studies are performed to determine the sensitivity of the per rev flutter speed to these parameters for a 35 m wind turbine blade. Additional studies are performed to determine which structural characteristics of the blade are most significant in explaining the previously mentioned per rev flutter speed differences. As a point of interest, flutter results are also reported for two recently designed 9 m twist/coupled blades.
Measurement of Tip Vortex Paths in the Wake of a HAWT Under Yawed Flow Conditions
Authors: Haans Wouter , Sant Tonio , van Kuik Gijs , van Bussel Gerard
Published: October 2005

Tip vortex locations have been measured in the wake of a model rotor in both axial flow and yaw using quantitative flow visualization. For each setting, the axial force coefficient has been derived, as well, from measurements. The results agree well with those previously published on the Delft University of Technology model rotor. The main interest is to determine the tip vortex pitch, wake skew angle, wake expansion, and to physically interpret the data. The results also help to validate and construct models. The tip vortex location data complement the existing skewed wake velocity data from hot-wire anemometry, making it a valuable experimental database.
Potential Load Reduction Using Airfoils with Variable Trailing Edge Geometry
Authors: Buhl Thomas , Gaunaa Mac , Bak Christian
Published: October 2005

This paper presents an investigation of the potential for reduction of fluctuating loads on wind turbine blades with the use of flaplike deflectable trailing edges. More specifically, the aeroelastic response of an elastically mounted airfoil section with a deflectable trailing edge is investigated. This is done by coupling a model for the aerodynamic forces on a deforming airfoil with a linear spring/damper model for the elastic deformation of a rigid airfoil to which the forces associated with the deflection of the trailing edge are added. The analysis showed that when the airfoil experienced a wind step from 10to12m∕s the standard deviation of the normal force could be reduced by up to 85% when the flap was controlled by the reading of the airfoil flapwise position and velocity, while reductions of up to 95% could be obtained when the flap was controlled by the reading of the angle of attack. When the airfoil experienced a turbulent wind field, the standard deviation of the normal force could be reduced by 81% for control based on measured angle of attack. The maximum reduction using a combination of flapwise position and velocity was 75%. The maximum deflection of the trailing edge geometry was, in all the considered cases, small enough to justify the use of a potential flow code for calculation of the aerodynamic forces. Calculations showed that the effect of a time lag in the actuators and sensors may drastically reduce the efficiency of the control algorithm. Likewise, the effect of a low maximum actuation velocity reduces the efficiency of the control algorithm. The analysis of the two-dimensional (2D) aeroservoelastic system shown in this paper indicates that the potential of using trailing edge flaps for reduction of fluctuating loads is significant.
Low-Dimensional Representations of Inflow Turbulence and Wind Turbine Response Using Proper Orthogonal Decomposition
Authors: Saranyasoontorn Korn , Manuel Lance
Published: October 2005

A demonstration of the use of Proper Orthogonal Decomposition (POD) is presented for the identification of energetic modes that characterize the spatial random field describing the inflow turbulence experienced by a wind turbine. POD techniques are efficient because a limited number of such modes can often describe the preferred turbulence spatial patterns and they can be empirically developed using data from spatial arrays of sensed input/excitation. In this study, for demonstration purposes, rather than use field data, POD modes are derived by employing the covariance matrix estimated from simulations of the spatial inflow turbulence field based on standard spectral models. The efficiency of the method in deriving reduced-order representations of the along-wind turbulence field is investigated by studying the rate of convergence (to total energy in the turbulence field) that results from the use of different numbers of POD modes, and by comparing the frequency content of reconstructed fields derived from the modes. The National Wind Technology Center’s Advanced Research Turbine (ART) is employed in the examples presented, where both inflow turbulence and turbine response are studied with low-order representations based on a limited number of inflow POD modes. Results suggest that a small number of energetic modes can recover the low-frequency energy in the inflow turbulence field as well as in the turbine response measures studied. At higher frequencies, a larger number of modes are required to accurately describe the inflow turbulence. Blade turbine response variance and extremes, however, can be approximated by a comparably smaller number of modes due to diminished influence of higher frequencies.
Self-Excitation and Harmonics in Wind Power Generation
Authors: Muljadi E. , Butterfield C. P. , Romanowitz H. , Yinger R.
Published: October 2005

Traditional wind turbines are commonly equipped with induction generators because they are inexpensive, rugged, and require very little maintenance. Unfortunately, induction generators require reactive power from the grid to operate; capacitor compensation is often used. Because the level of required reactive power varies with the output power, the capacitor compensation must be adjusted as the output power varies. The interactions among the wind turbine, the power network, and the capacitor compensation are important aspects of wind generation that may result in self-excitation and higher harmonic content in the output current. This paper examines the factors that control these phenomena and gives some guidelines on how they can be controlled or eliminated.
Structure and acoustical properties of PTMEG polyurethanes
Authors: Thompson Corley M. , Gebert Karen L.
Published: October 2005

Polyurethanes are widely used in underwater acoustical devices because of their convenience and attractive physical properties. Rarely, however, have these polyurethanes been designed for the specific application. More typically, a commercial material is used in both sound-transmission and sound-absorption applications, usually with little understanding of structural parameters that control the acoustical properties. This paper will show that the acoustical properties of these polyurethanes may be modified by changing the size of the PTMEG softblock, and that adjustment of the softblock components is ineffective in producing such changes. Evidence will be presented that the structural mechanism for the correlation between acoustical properties and softblock size is the decreasing solubility of the hardblock material with increasing softblock molecular weight. This decreased solubility results in a more pure softblock and in lower dynamic losses and lower specific acoustic impedance. The evidence for this is the regular change in the softblock's glass transition temperature with molecular weight. The acoustical ramifications of these relationships will be discussed.
Relationship between polyurethane composition and viscoelastic properties of model urethane systems
Authors: Capps R. N. , Stack G. M. , Dodd E. M. , Chang E. Y.
Published: October 2005

A study was performed to determine the relationship between polyurethane composition and viscoelastic properties in a series of model urethane compounds. The compositional variables studied included the nature of the soft segment, amount of hard segment, and cure stochiometry. Model urethanes were prepared using the aliphatic diisocyanate, metatetramethylene diisocyanate (m-TMXDI). This aliphatic isocyanate is less reactive than commonly used aromatic isocyanates and does not undergo the secondary cross-linking reactions commonly observed with aromatic isocyanates. The urethanes chosen for this study contained soft segments based on hydroxy-terminated polybutadiene (HTPBD) or polycaprolactone (PCL), which is a highly polar material in which extensive phase mixing should occur. In contrast, polyurethanes based on HTPBD should undergo more complete phase separation. Prepolymers were prepared with both of these soft segments and with available isocyanate contents varying from 3.7% to 5.7%. Diethyltoluene diamine (DETDA) was used to cure these prepolymers over a range of cure stochiometries. Thermal transitions attributed to the hard and soft segments were observed in these urethanes using a Perkin-Elmer DSC-4. Dynamic mechancial behavior was measured using both a Polymer Labs dynamic mechanical thermal analyzer (DMTA) and a resonance apparatus developed at the NRL-USRD. [Sponsored by ONT.]