bluuebunny/crossref_metadata_2025 huggingface dataset:
EVIDENCE FOR ASEXUAL RESTING CYSTS IN THE LIFE CYCLE OF THE MARINE PERIDINOID DINOFLAGELLATE,SCRIPPSIELLA HANGOEI1
Authors: Kremp Anke , Parrow Matthew W.
Published: April 2006

Scrippsiella hangoei(Schiller) Larsen is a peridinoid dinoflagellate that grows during winter and spring in the Baltic Sea. In culture this species formed round, smooth cysts when strains were mixed, indicating heterothallic sexuality and hypnozygote production. However, cysts of the same morphology were also formed in clonal strains exposed to slightly elevated temperature. To better understand the role of cysts in the life cycle ofS. hangoei, cyst formation and dormancy were examined in culture experiments and the cellular DNA content of flagellate cells and cysts was compared in clonal and mixed strains using flow cytometry.S. hangoeiexhibited a high rate of cyst formation in culture. Cysts produced in both clonal and mixed strain cultures were thick‐walled and underwent a dormancy period of 4 months before germinating. TheS. hangoeiflagellate cell population DNA distributions consisted of 1C, intermediate, and 2C DNA, indicative of respective eukaryotic cell cycle phases G1, S, and G2M. The majority (>95%) of cysts had a measured DNA content equivalent to the lower 1C DNA value, indicating a haploid nuclear phase and an asexual mode of cyst formation. A small percentage (<5%) of cysts produced in the mixed strain culture had 2C DNA, and thus could have been diploid zygotes. These findings represent the first measurements of dinoflagellate resting cyst DNA content, and provide the first quantitative evidence for dinoflagellate asexual resting cysts. Asexual resting cysts may be a more common feature of dinoflagellate life cycles than previously thought.
UNICELLULAR CYANOBIONTS IN OPEN OCEAN DINOFLAGELLATES, RADIOLARIANS, AND TINTINNIDS: ULTRASTRUCTURAL CHARACTERIZATION AND IMMUNO‐LOCALIZATION OF PHYCOERYTHRIN AND NITROGENASE1
Authors: Foster Rachel A. , Carpenter Edward J. , Bergman Birgitta
Published: April 2006

Cyanobacterial symbionts (cyanobionts) have been identified forming associations with various open ocean eukaryotic host genera, including two dinophysoid genera, Histioneis sp. and Ornithocercus sp., two radiolarians, Spongastaurus and Dictyocoryne truncatum, sp., and a tintinnid, Codonella sp. The TEM analysis revealed that single individual hosts were closely associated with one to two different cyanobacterial morphotypes (cyanobionts) and two hosts had in addition to cyanobionts, one to two bacterial cell types. Eleven significantly (P<0.01) different cell types were identified as cyanobionts, with cell diameters ranging 0.5±0.38–3.7±0.66 μm. Using immunogold‐labeling techniques coupled to the TEM, four of the five cell types contained phycoerythrin (PE) at high levels (>71±28 gold particles·μm−2). Immunolabeling‐TEM using nitrogenase antisera demonstrated a significant (P<0.01) nitrogenase content in cell type four cyanobionts of Histioneis sp. host 1 (39±34 gold particles·μm−2). The cyanobionts of the radiolarians were of a cell diameter (0.5–0.8 μm) and showed ultrastructural characters (peripheral thylakoids) reminiscent of Prochlorococcus sp. Also, an open ocean tintinnid, Codonella sp., was shown to contain cyanobacteria as symbionts for the first time. In all cyanobionts, glycogen storage was obvious, no cellular degradation was visible, cells were observed in the process of cellular division, and antisera localization was apparent. These observations suggest that the relationship between host eukaryote and cyanobacteria is an active one, and likely symbiotic.
APOPTOTIC‐LIKE CELL DEATH PATHWAY IS INDUCED IN UNICELLULAR CHLOROPHYTE CHLAMYDOMONAS REINHARDTII (CHLOROPHYCEAE) CELLS FOLLOWING UV IRRADIATION: DETECTION AND FUNCTIONAL ANALYSES1
Authors: Moharikar Swati , D'Souza Jacinta S. , Kulkarni Atul B. , Rao Basuthkar J.
Published: April 2006

Chlamydomonas reinhardtii (Ehrenberg) cells exhibited cell death process akin to that of apoptosis when exposed to ultraviolet (UV)‐C irradiation (1–100 J/m2). We observed typical hallmarks of apoptosis including cell shrinkage, associated nuclear morphological changes, flipping of phosphatidylserine, and DNA fragmentation detected by the terminal deoxynucleotidyl transferase‐mediated dUTP nick end‐labeling assay and oligonucleosomal DNA laddering assay. Interestingly, fluorescence imaging of DNA changes in UV‐C exposed cells, following PicoGreen staining, revealed that extra‐nuclear DNA disintegrates before that of nuclear changes, where the latter extensively diffuses out of the nuclear compartment, spreading into the whole cell and reaching the periphery of dying cells. Antibodies against a mammalian caspase‐3 shared epitopes with a protein of 28 kDa; whose pattern of expression correlated with the onset of cell death. Moreover, growth experiments indicate that spent medium recovered from UV‐C exposed cells exhibit a protective effect against cell killing of fresh cultures of C. reinhardtii cells by UV irradiation. The protective effect of UV‐spent medium is not a general growth promotional response on normal cells, but rather, is specific to UV‐exposed cells. We propose a model that C. reinhardtii cells exposed to UV elicit apoptotic‐like changes, which in turn lead to an adaptive response in neighboring cells against fresh rounds of UV exposure, thereby promoting survival of the cell population.
ICE‐BINDING PROTEINS FROM SEA ICE DIATOMS (BACILLARIOPHYCEAE)1
Authors: Janech Michael G. , Krell Andreas , Mock Thomas , Kang Jae‐Shin , Raymond James A.
Published: April 2006

Sea ice diatoms thrive under conditions of low temperature and high salinity, and as a result are responsible for a significant fraction of polar photosynthesis. Their success may be owing in part to secretion of macromolecules that have previously been shown to interfere with the growth of ice and to have the ability to act as cryoprotectants. Here we show that one of these molecules, produced by the sea ice diatom Navicula glaciei Vanheurk, is a ∼25 kDa ice‐binding protein (IBP). A cDNA obtained from another sea ice diatom, Fragilariopsis cylindrus Grunow, was found to encode a protein that closely matched the partially sequenced N. glaciei IBP, and enabled the amplification and sequencing of an N. glaciei IBP cDNA. Similar proteins are not present in the genome of the mesophilic diatom Thalassiosira pseudonana. Both proteins closely resemble antifreeze proteins from psychrophilic snow molds, and as a group represent a new class of IBPs that is distinct from other IBPs found in fish, insects and plants, and bacteria. The diatom IBPs also have striking similarities to three prokaryotic hypothetical proteins. Relatives of both snow molds and two of the prokaryotes have been found in sea ice, raising the possibility of a fungal or bacterial origin of diatom IBPs.
MODELING PHYTOPLANKTON ABUNDANCE IN SAGINAW BAY, LAKE HURON: USING ARTIFICIAL NEURAL NETWORKS TO DISCERN FUNCTIONAL INFLUENCE OF ENVIRONMENTAL VARIABLES AND RELEVANCE TO A GREAT LAKES OBSERVING SYSTEM1
Authors: Millie David F. , Weckman Gary R. , Pigg Ryan J. , Tester Patricia A. , Dyble Julianne , Wayne Litaker R. , Carrick Hunter J. , Fahnenstiel Gary L.
Published: April 2006

Abstract
Phytoplankton abundance, as chl a, in Saginaw Bay, Lake Huron was modeled using artificial neural networks. Suites of abiotic variables served as predictors for the trends/patterns in chl a concentrations. Spatial and temporal gradients of sampling stations throughout the bay were evident, with physical/chemical differences arising from hydrological/meteorological forcing and zebra mussel recruitment. Chlorophyll a concentrations displayed corresponding disparities; concentrations differed between the inner and outer bays and varied intra‐ and inter‐annually. Trained networks reproduced the intrinsic variance and magnitude of chl a dynamics. Modeled‐measured concentrations best approximated a 1:1 relationship in a hybrid network incorporating both supervised and unsupervised training whereas concentrations greater than 15 μg/L were underestimated in networks utilizing only supervised training, likely because of inadequate training data. Variables indicative of phytoplankton nutrition, acting as proxy measurements of algal biomass, and/or corresponding to descriptors of hydrological and meteorological forcing had the greatest influence upon modeled concentrations. A conjunctive decision tree and a novel sensitivity analysis provided rule‐based information and comprehensible interpretation of relationships among multiple predictor variables. From this, the “knowledge” embedded in trained networks proved extractable and usable for ecological theory generation and/or decision making within water‐quality problem solving. Forecasting initiatives within the developing Great Lakes Observing System may be best served by embedding neural networks in mechanistic models to quantitatively initialize variables, qualitatively delineate conditions for projecting ecological structure, and/or estimate deviations from predictability within mechanistic simulations.
DEFINING THE MAJOR LINEAGES OF RED ALGAE (RHODOPHYTA)1
Authors: Yoon Hwan Su , Müller Kirsten M. , Sheath Robert G. , Ott Franklyn D. , Bhattacharya Debashish
Published: April 2006

Previous phylogenetic studies of the Rhodophyta have provided a framework for understanding red algal phylogeny, but there still exists the need for a comprehensive analysis using a broad sampling of taxa and sufficient phylogenetic information to clearly define the major lineages. In this study, we determined 48 sequences of the PSI P700 chl a apoprotein A1 (psaA) and rbcL coding regions and established a robust red algal phylogeny to identify the major clades. The tree included most of the lineages of the Bangiophyceae (25 genera, 48 taxa). Seven well‐supported lineages were identified with this analysis with the Cyanidiales having the earliest divergence and being distinct from the remaining taxa; i.e. the Porphyridiales 1–3, Bangiales, Florideophyceae, and Compsopogonales. We also analyzed data sets with fewer taxa but using seven proteins or the DNA sequence from nine genes to resolve inter‐clade relationships. Based on all of these analyses, we propose that the Rhodophyta contains two new subphyla, the Cyanidiophytina with a single class, the Cyanidiophyceae, and the Rhodophytina with six classes, the Bangiophyceae, Compsopogonophyceae, Florideophyceae, Porphyridiophyceae classis nov. (which contains Porphyridium, Flintiella, and Erythrolobus), Rhodellophyceae, and Stylonematophyceae classis nov. (which contains Stylonema, Bangiopsis, Chroodactylon, Chroothece, Purpureofilum, Rhodosorus, Rhodospora, and Rufusia). We also describe a new order, Rhodellales, and a new family, Rhodellaceae (with Rhodella, Dixoniella, and Glaucosphaera).
Variable Dielectrics in the Calcium Magnesium Titanate System Characterized with Scanning Microwave Microscopy
Authors: Wing Zachary N. , Halloran John W. , Zhang Qinxin , McGinn Paul J.
Published: April 2006

Near‐field scanning microwave microscopy (SMM) is used to observe the fine‐scale dielectric phenomena. The purpose of the present study is to apply the SMM to examine the dielectrics in the multiphase CT–MT–M2T system and study the dielectric relative permittivity

distribution. SMM clearly resolves the three‐phase distribution and is in agreement with chemical analysis.
White sponge naevus with minimal clinical and histological changes: report of three cases
Authors: Lucchese Alberta , Favia Gianfranco
Published: April 2006

White sponge naevus (WSN) is a rare autosomal dominant disorder that predominantly affects non‐cornified stratified squamous epithelia: oral mucosa, oesophagus, anogenital area. It has been shown to be related to keratin defects, because of mutations in the genes encoding mucosal‐specific keratins K4 and K13. We illustrate three cases diagnosed as WSN, following the clinical and histological criteria, with unusual appearance. They presented with minimal clinical and histological changes that could be misleading in the diagnosis. The patients showed diffuse irregular plaques with a range of presentations from white to rose coloured mucosae involving the entire oral cavity. In one case the lesion was also present in the vaginal area. The histological findings included epithelial thickening, parakeratosis and extensive vacuolization of the suprabasal keratinocytes, confirming WSN diagnosis. Clinical presentation and histopathology of WSN are discussed in relation to the differential diagnosis of other oral leukokeratoses.
Validity and reliability of functional performance tests in meniscectomized patients with or without knee osteoarthritis
Authors: Bremander A. B. , Dahl L. L. , Roos E. M.
Published: April 2006

Aims: Reduced functional performance and muscular dysfunction after knee injury and in knee osteoarthritis (OA) is suggested to be a factor in OA development. Validated functional performance tests applicable in the clinic and large‐scale studies are lacking. The aim was to study the reliability and validity of 10 functional performance tests.

Methods: Two hundred and eighty‐five subjects, 15–22 years post‐meniscectomy, performed 10 functional performance tests. The mean age was 54 years (SD±11.2) and 79% were men; 52% had radiographic OA, and 48% were categorized as symptomatic. The tests were evaluated for test–retest reliability, discriminative ability (younger vs older age, men vs women, symptom‐free vs symptomatic) and floor and ceiling effects.

Results: Two of the 10 tests, maximum number of knee bendings in 30 s and one‐leg hop for distance, had good test–retest reliability (ICC 0.92, 95% CI 0.86–0.96 and 0.93, 95% CI 0.87–0.97) and were able to discriminate with regard to age, gender and symptoms, and had acceptable floor effects (9% and 3%, respectively).

Conclusion: This study suggests the use of two functional performance tests: knee bendings/30 s and one‐leg hop for distance, easy to use for evaluation of interventions due to knee injury and knee OA and when attaining long‐term data of natural disease history.
Relationships between postural balance, rifle stability and shooting accuracy among novice rifle shooters
Authors: Mononen K. , Konttinen N. , Viitasalo J. , Era P.
Published: April 2006

The present study examined the relationships between shooting accuracy and shooters' behavioral performance, i.e., postural balance and gun barrel stability, among novice rifle shooters in intra‐ and inter‐individual levels. Postural balance and rifle stability were assessed in terms of anteroposterior (VELAP) and mediolateral (VELML) sway velocity of the movement of center of pressure, and horizontal (DEVH) and vertical (DEVV) deviation of the aiming point. The participants (n=58) performed 30 shots in the standing position at a distance of 10 m from the target. The data showed that shooting accuracy was related to postural balance and rifle stability, but only at the inter‐individual level. The correlation coefficients between shooting score and behavioral performance variables ranged from −0.29 to −0.45. The stepwise multiple regression analysis revealed that the VELML and the DEVH as independent variables accounted for 26% of the variance in the shooting score. The results also suggested that postural balance is related to the shooting accuracy both directly and indirectly through rifle stability. As the role of postural balance appeared to be important in shooting performance, the use of additional balance training programs to improve a shooter's postural skills should be encouraged.
Toxicity of endodontic filling materials
Authors: DAHL JON E.
Published: April 2006

The toxicity of endodontic materials is reviewed. The patient may be exposed by constituents leaching from the unset and set sealer and by accidental overfilling of the root canal. For most patients the exposure is believed to be below the threshold for a toxic effect. Most sealers exhibited a cytotoxic response, especially unset and the responses diminished with time after setting. Unset and newly set endodontic material may also have a toxic potential in vivo that may result in a localized inflammation postponing the healing of an apical periodontitis. Root canal sealers containing paraformaldehyde is of biological concern.
Acne therapy with topical benzoyl peroxide, antibiotics and azelaic acid
Authors: Worret Wolf‐Ingo , Fluhr Joachim W.
Published: April 2006

Benzoyl peroxide (BPO) was introduced in the treatment of acne in 1934. Despite the fact that only few randomized trials have been published, BPO is considered the standard in topical acne treatment. Anaerobic bacteria are reduced by oxidative mechanisms and the induction of resistant strains is reduced. Topical formulations are available at concentrations of 2.5, 5, 10 and 20 %. The effect is dose‐dependent, but the irritation increases with higher concentrations. Usually 5 % BPO is sufficient to control acne grade I‐II. Due to its strong oxidative potential, patients should be advised that BPO may bleach colored and dark clothing, bedding and even hair. BPO is safe for use in pregnant and lactating females because it is degraded to benzoic acid. It is a cost‐effective treatment for acne grade I–II.

Patients with papulopustular acne grade I–II, particularly with marked inflammation, show satisfactory improvement with topical antibiotic treatment. The following compounds are available and effective: erythromycin, clindamycin and tetracycline (the latter being less frequently used). A review in 1990 suggested that topical tetracycline was ineffective in the treatment of acne. Along with eliminating Propionibacterium acnes, the main mechanism of topical antibiotics is their antiinflammatory effect. All three penetrate the epidermal barrier well and are similarly efficacious. Randomized trials have shown that in concentrations of 2–4 %, their effects are comparable to oral tetracycline and minocycline. Combination therapy with retinoids or benzoyl peroxide (BPO) increases efficacy. Retinoids increase penetration and reduce comedones, while topical antibiotics primarily address inflammation. One side effect of topical antibacterial treatment is an increase in drug‐resistant resident skin flora with gram‐negative microorganisms prevailing, which can lead to gram‐negative folliculitis. All three antibiotics fluoresce under black light which may produce interesting effects in a discotheque. There are two reports of topical clindamycin causing pseudomembranous colitis after long‐term and widespread usage.

Azelaic acid has a predominant antibacterial action, although it is not considered as an antibiotic in the classical sense. Furthermore, it possesses a modest comedolytic effect. Burning upon application is common. Since azelaic acid is naturally present, systemic side effects are not likely to occur, making it safe for acne treatment during pregnancy and lactation.
Post‐marketing surveillance on treatment of 5,665 patients with atopic dermatitis using the calcineurin inhibitor pimecrolimus: Positive effects on major symptoms of atopic dermatitis and on quality of life
Authors: Sunderkötter Cord , Weiss Johannes M. , Bextermöller Raphael , Löffler Helena , Schneider Dirk
Published: April 2006

Background: Topical application of the calcineurin inhibitors pimecrolimus and tacrolimus is a current major advance in the therapy of atopic dermatitis. The aims of this post‐marketing surveillance were: a) to acquire data on the efficacy and tolerability of pimecrolimus ointment (Elidel®) on a very large cohort of patients from outpatient clinics, and b) to assess changes in their quality of life, a parameter not often considered in previous studies.

Patients and methods: Included were 5,665 patients with atopic dermatitis. During the observation period, data on efficacy and tolerability were obtained at the beginning of the study, 3 to 10 days after initiation of therapy and after 4 to 6 weeks. Evaluation of symptoms as well as assessment of efficacy and tolerability were based on linear scales and on the percentage of the body surface area (% BSA) involved. Quality of life was assessed by the German version of the “Dermatology Life Quality Index (DLQI)” or the “Children's Dermatology Life Quality Index (CDLQI)”.

Results: In this largest post‐marketing surveillance hitherto performed in Germany, the efficacy of pimecrolimus was judged as “good” by 79.3 % of physicians and by 76.5 % of patients. Tolerability was assessed as “good” by 87.2 % of physicians and by 83.1 % of patients. Major symptoms of atopic dermatitis such as pruritus, erythema or lichenification showed marked reduction after just 3 to 10 days, signalling general improvement of the skin disease. In addition, application of pimecrolimus resulted in a significant improvement of the quality of life scores in both children and adults.

Conclusion: The present study demonstrates that the good efficacy and tolerability of pimecrolimus ointment which had been shown in controlled trials: i) could also be demonstrated on a very large cohort of patients with atopic dermatitis when used in the outpatient setting, and ii) were paralleled by a significant improvement in the quality of life.
Keratosis pilaris and keratosis pilaris atrophicans faciei
Authors: Arnold Andreas W. , Buechner Stanislaw A.
Published: April 2006

Keratosis pilaris and ulerythema ophryogenes (keratosis pilaris atrophicans faciei) are hereditary disorders with altered follicular keratinization that show follicular, horny papules surrounded by an erythematous halo. Ulerythema ophryogenes is an uncommon variant of keratosis pilaris characterized by erythematous follicular papules of the eyebrows and cheeks followed by a gradual loss of hair. On the background of 15‐year‐old boy who presented with keratosis pilaris and ulerythema ophryogenes, we discuss the various clinical manifestations of keratosis pilaris.
Skin ulceration after leflunomide treatment in two patients with rheumatoid arthritis
Authors: Jakob Antje , Porstmann Romy , Rompel Rainer
Published: April 2006

Leflunomide is a disease‐modifying antirheumatic drug for the treatment of active rheumatoid arthritis and psoriatic arthritis. Skin ulcerations are not listed as a side effect for this drug, and there has been only one case report on leflunomide associated skin ulcerations. We report on two females, 59 and 63 years old respectively, who were treated with leflunomide for rheumatoid arthritis and subsequently developed severe skin ulcerations. After discontinuation of the drug the skin ulcerations healed complete even if very slowly.
Ehlers‐Danlos syndrome – 20 years experience with diagnosis and classification
Authors: Proske Sylvia , Hartschuh Wolfgang , Enk Alexander , Hausser Ingrid
Published: April 2006

Background: The Ehlers‐Danlos syndrome encompasses a group of hereditary disorders of the connective tissue, characterized by hyperextensible skin, joint hypermobility; and varying degrees of vessel and tissue fragility. The main forms are classical,hypermobile,vascular,kyphoscoliotic A/B,arthrochalasis A/B and dermatosparaxis types.

Patients and Methods: We report our experience in diagnosis and classification of Ehlers‐Danlos‐syndrome, especially with the combination of clinical and morphological criteria, at the Department of Dermatology of the University of Heidelberg with more than 600 patients between 1984 and 2004.

Results: We classified those types of EDS which are characterized by regular and characteristic ultrastructural changes in the dermal components, primarily collagen, including the classical, hypermobile and vascular types as well as the less‐common arthrochalasis and dermatosparaxis types. The combination of clinical and morphologic features facilitates the selection of candidate genes for molecular genetic investigation.

Conclusions: Besides the skin, skeleton and vessels, many other organ systems such as eyes and intestine, can be affected in Ehlers‐Danlos syndrome. Accordingly, interdisciplinary cooperation (pediatrics, surgery, orthopedics, rheumatology, neurology, genetics) is necessary. As the connective tissue of the skin is accessible for biopsy and diagnostic investigation, dermatologists should be trained in the diagnostic approach and classification of this syndrome.
Investigation of risk factors for surgical wound infection among teaching hospitals in Tehran
Authors: Arabshahi Kamran Soltani , Koohpayezade Jalil
Published: April 2006

This prospective study was carried out to investigate the risk factors and incidence of surgical site infection (SSI) among patients in surgical wards of five hospitals affiliated to Iran University of Medical Sciences. Data was collected in a register card filled by specially trained staff. Nine‐hundred and eighteen patients admitted in surgical wards were followed 30 days postoperatively for SSI during 1 April 2003 to 30 September 2003. A total of 77 patients were identified among 918 cases included in the study, with a resulting overall SSI rate of 8·4%. The risk of SSI was increased by age older than 60 years (OR = 3·9; P < 0·0001), diabetes mellitus (OR = 4·9; P < 0·0001), smoking (OR = 3·1; P < 0·0001), obesity (OR = 4·1; P < 0·0001) and wound drain (OR = 2·2; P < 0·0001). There were significant statistical difference in duration of anaesthesia (131·6 vs. 177 min, P < 0·001) and duration of surgery (99 vs. 140·5) between patients without SSI and patients with SSI. In conclusion, identification of the risk factors for SSI will help physicians to improve patient care and may decrease mortality and morbidity and hospital care costs of surgery patients.
Labdane Diterpenoids from Coleus forskohlii (Willd.) Briq.
Authors: Xu Ling‐Ling , Kong Ling‐Yi
Published: April 2006

In order to investigate the active substances of Coleus forskohlii (Willd.) Briq., a new labdane diterpenoid, 12‐hydroxy‐8, 13E‐labdadien‐15‐oic acid, together with two 8, 13‐epoxylabd‐14‐ene‐11‐one diterpenoids, 6‐acetyl‐1‐deoxyforskolin and 6‐acetyl‐1,9‐dideoxyforskolin, was isolated on the basis of various chromatographic techniques and spectroscopic methods.

(Managing editor: Wei Wang)
Walnut Staminate Flowers Can Be Explored as a Supplementary Plant Oil Source
Authors: Jia Husen , Xu Yinong
Published: April 2006

Fossil fuel is currently the major energy source driving global socio‐economy, but its stock is being heavily depleted due to increasing anthropogenic activities worldwide. There are also concerns regarding the burning of fossil fuels, which contributes to global climate warming and air pollution. As such, the development of biodiesel as a non‐toxic, biodegradable, and renewable alternative energy source using oil crops such as soybean and rapeseed has quickly emerged in the West countries. However, the production of oil crops in China is far from sufficient to meet the demands of the country's population of 1.3 billion, and increasing oil crop production is inhibited by a severe shortage of agricultural land, which currently averages 0.2 acre per person and, as such, is less than half the world average. The current national policy in China regarding land use is more towards revering cultivated lands in ravins and hills to forestry, which presents an ideal opportunity to further develop plantations of walnut (Juglans regia L.) trees, a plant that is tolerant to drought and infertile soils and has a high oil content. Study in this paper shows that one ament of walnut staminate flowers produces about 0.168 g dry pollen, and the dry pollen contained 49.67% oil. Based on this discovery, oil yield obtained from staminate flowers is estimated to reach 6.95% of that from walnut nuts. Thus walnut staminate flower is suggested to explore as supplementary plant oil source, and has a great opportunity to utilize as a biodiesel feedstock.

(Managing editor: Wei Wang)
The Cathaysia Flora and the Mixed Late Permian Cathaysian‐Angaran Floras in East Asia
Authors: Sun Ke‐Qin
Published: April 2006

The Cathaysia flora, one of the most prominent floras of the Carboniferous and Permian, was mainly distributed in East Asia and was characterized by numerous endemic elements. China is one of the most important localities of the Cathaysia flora and it is also the center of origin of this flora. This paper reviews and discusses the characteristics of the Cathaysia flora and the biogeographically mixed Permian Cathaysian‐Angaran floras of East Asia. In addition, the formative mechanism of the mixed Permian floras is also discussed.

(Managing editor: Ya‐Qin)
Effects of Overexpression of the Endogenous Farnesyl Diphosphate Synthase on the Artemisinin Content in Artemisia annua L.
Authors: Han Jun‐Li , Liu Ben‐Ye , Ye He‐Chun , Wang Hong , Li Zhen‐Qiu , Li Guo‐Feng
Published: April 2006

Artemisinin is a novel effective antimalarial drug extracted from the medicinal plant Artemisia annua L. Owing to the tight market and low yield of artemisinin, there is great interest in enhancing the production of artemisinin. In the present study, farnesyl diphosphate synthase (FPS) was overexpressed in high‐yield A. annua to increase the artemisinin content. The FPS activity in transgenic A. annua was two‐ to threefold greater than that in non‐transgenic A. annua. The highest artemisinin content in transgenic A. annua was approximately 0.9% (dry weight), which was 34.4% higher than that in non‐transgenic A. annua. The results demonstrate the regulatory role of FPS in artemisinin biosynthesis.

(Managing editor: Wei Wang)
Two New Cytotoxic Sesquiterpenoids from Eupatorium lindleyanum DC.
Authors: Huo Jun , Yang Sheng‐Ping , Ding Jian , Yue Jian‐Min
Published: April 2006

Two new sesquiterpenoid lactones, namely eupalinilides K and L, were isolated from Eupatorium lindleyanum DC. Their structures were determined by spectral methods, including 1D‐ and 2D‐NMR spectra. Cytotoxic evaluation showed that eupalinilide L exhibited potent cytotoxicity against P‐388 and A‐549 tumor cell lines with IC50 values of 0.17 and 2.60 μmol/L, respectively.

(Managing editor: Wei Wang).
Anthocyanin Accumulation Mediated by Blue Light and Cytokinin in Arabidopsis Seedlings
Authors: Chen Da‐Qing , Li Zhi‐Yang , Pan Rui‐Chi , Wang Xiao‐Jing
Published: April 2006

It has been reported that pigmentation in plants is stimulated by light and cytokinin (CTK); however, the signaling pathways and the relationship between light and CTK involved in the regulation of anthocyanin accumulation remain to be elucidated. We investigated (i) the role of blue light (BL) and CTK in anthocyanin accumulation ; and (ii) the relationship between BL and CTK in wild type (WT) and hy4 mutants of Arabidopsis thaliana. Two‐d‐old seedlings grown on medium with or without kinetin (KT) or zeatin (ZT) in darkness were irradiated using BL at different fluence rates for 3 d before the anthocyanin content was determined using a spectrophotometric method. Anthocyanin accumulation was strongly induced by BL in WT seedlings but not in hy4 seedlings, which demonstrated that CRY1 is the main photoreceptor for BL. Both KT and ZT enhanced the response of the WT seedlings to BL in a dose‐dependent manner, whereas they were not sufficient to promote anthocyanin accumulation in darkness. In addition, data from experiments using the hy4 mutant showed that the CTK effect of BL was also CRY1‐dependent. The results from experiments with three different treatment programs showed that the relationship between BL and KT in anthocyanin accumulation of Arabidopsis seedlings seems neither multiplicative nor additive coaction, but rather interaction. BL is necessary for anthocyanin accumulation, and KT might be involved in the BL signaling pathway.

(Managing editor:Ping He)
Clonal Plasticity in Response to Reciprocal Patchiness of Light and Nutrients in the Stoloniferous Herb Glechoma longituba L.
Authors: Chu Yu , Yu Fei‐Hai , Dong Ming
Published: April 2006

Interconnected ramets of clonal plants can functionally specialize in the uptake of resources from aboveground and/or underground sources. Ramet pairs of the clonal stoloniferous herb Glechoma longituba L. were grown in spatially heterogeneous environments with complementary availability of light and nutrients. Plasticity with respect to root‐shoot ratio, fitness‐related traits (biomass, number of ramets and dry weight per ramet), morphological traits (lamina area, root length) were experimentally examined. The aim was to understand the adaptation of G. longituba to an environment with reciprocal patchiness of light and soil nutrients by plasticity in its root‐shoot ratio and clonal morphology. The results showed that the performance of ramets growing in patches with high light intensity and low soil nutrients into the adjacent opposite patches was increased in terms of fitness‐related traits. However, the performance of those from patches with low light intensity and high soil nutrients into the adjacent opposite patches was not changed. The root‐shoot ratio and clonal morphology were plastic. Morphological traits such as lamina area and root length were altered in a way that enhanced the capture of light resources and soil nutrients. Apparent reciprocal resource transport between the ramets in an environment of reciprocal patchiness of resources can enhance the growth of ramets with complementary resource deficiencies.

(Managing editor: Ya‐Qin Han)
Effect of Water Deficit on Self‐thinning Line in Spring Wheat (Triticum aestivum L.) Populations
Authors: Liu Jing , Wei Liang , Wang Chun‐Ming , Wangl Gen‐Xuan , Wei Xiao‐Ping
Published: April 2006

Monocultures of spring wheat (Triticum aestivum L.) were grown at overcrowded densities (10 000 and 3 000 plants per m2) under well‐watered and water‐stressed conditions to investigate the effects of water deficits on self‐thinning. The results showed that density reduction in water‐stressed populations was delayed compared with that in well‐watered populations. Populations grown in well‐watered conditions conformed to the ‐3/2‐power law. Compared with the well‐watered condition, there was no significant decrease of the self‐thinning line underwater‐stressed conditions in this experiment, although the rate of average shoot biomass accumulation decreased. This result implied that the exponent of the ‐3/2‐power equation is not as sensitive as the rate of average shoot biomass accumulation to water stress. Further analysis indicated that, in each density treatment, the lines of the height versus shoot biomass relationships did not differ significantly between the two water conditions. However, the intercepts of the height versus shoot biomass relationships were greater in the higher‐density populations (10 000/m2) than those in the lower‐density populations (3 000/m2). These results showed that water deficit did not change plant geometry in this experiment. That is to say, shoot competition for light remains constant at a given biomass, although root competition for water becomes more serious in water deficit conditions. Based on these results and previous reports we propose that, to affect the thinning line slope, changes in symmetric competition are not as efficient as changes in asymmetric competition.

(Managing editor: Ya‐Qin Han)
Contribution of Root Respiration to Total Soil Respiration in aLeymus chinensis(Trin.) Tzvel. Grassland of Northeast China
Authors: Wang Wei , Guo Ji‐Xun , Feng Jiang , Oikawa Takehisa
Published: April 2006

The loss of carbon through root respiration is an important component of grassland carbon budgets. However, few data are available concerning the contribution of root respiration to total soil respiration in grasslands in China. We investigated seasonal variations of soil respiration rate, root biomass, microbial biomass C and organic C content of the soil in a semi‐aridLeymus chinensis(Trin.) Tzvel. grassland of northeast China during the 2002 growing season (from May to September). The linear regression relationship between soil respiration rate and root biomass was used to determine the contribution of root respiration to total soil respiration. Soil respiration rate ranged from 2.5 to 11.9 g C/m2per d with the maximum in late June and minimum in September. The microbial biomass C and organic C content of the soil ranged from 0.3 to 1.5 g C/m2and from 29 to 34 g C/kg respectively. Root biomass had two peaks, in early June (1.80 kg/m2) and mid‐August (1.73 kg/m2). Root respiration rate peaked in mid‐August (6.26 g C/m2per d), whereas microbial respiration rate peaked in late June (7.43 g C/m2per d). We estimated that the contribution of root respiration to total soil respiration during the growing season ranged from 38% to 76%.

(Managing editor: Ya‐Qin Han)
Achene Wall Anatomy and Surface Sculpturing of Lactuca L. and Related Genera (Compositae: Lactuceae) with Notes on Their Systematic Significance
Authors: Zhu Shi‐Xin , Qin Hai‐Ning , Shih Chu
Published: April 2006

The achene wall anatomy and surface sculpturing of 14 species representing Lactuca L. and related genera were investigated to evaluate inter‐ and intrageneric relationships. The achene wall anatomy of the studied species can be divided into two types: winged and ribbed. The winged type is present in Lactuca L., Pterocypsela Shih, Cicerbita Wallr., Chaetoseris Shih and Stenoseris Shih, and is characterized by protruding wings and costae in transverse section. Winged type achene mesocarps are composed of parenchymatous cells and fiber cells, and the distinct fibrous strands are confined to the costae or wings of the achenes. The ribbed type is present in Notoseris Shih and Paraprenanthes Chang ex Shih, and is characterized by only having costae in transverse section. Fiber cells are continuous in the costae and intercostae. In surface sculpturing, the ornamentation and the shape of epidermal cells are different among these genera. The results indicate that L. altaica and L. serriola should be conspecific, and that L. dolichophylla is probably an intermediate taxon between Lactuca and Chaetoseris. The results also support the separation of Pterocypsela, Paraprenanthes, Notoseris, Chaetoseris and Stenoseris from Lactuca and Cicerbita as independent entities. Close affinities between Pterocypsela and Lactuca, Paraprenanthes and Notoseris, and Chaetoseris and Stenoseris are also proposed.

(Managing editor: Wei Wang)
Expression of theGrifola frondosaTrehalose Synthase Gene and Improvement of Drought‐Tolerance in Sugarcane(Saccharum officinarumL.)
Authors: Zhang Shu‐Zhen , Yang Ben‐Peng , Feng Cui‐Lian , Chen Ru‐Kai , Luo Jing‐Ping , Cai Wen‐Wei , Liu Fei‐Hu
Published: April 2006

Trehalose is a nonreducing disaccharide of glucose that functions as a protectant in the stabilization of biological structures and enhances stress tolerance to abiotic stresses in organisms. We report here the expression of aGrifola frondosatrehalose synthase(TSase)gene for improving drought tolerance in sugarcane(Saccharum officinarumL.). The expression of the transgene was under the control of two tandem copies of the CaMV35S promoter and transferred into sugarcane byAgrobacterium tumefaciensEHA105. The transgenic plants accumulated high levels of trehalose, up to 8.805–12.863 mg/g fresh weight, whereas it was present at undetectable level in nontransgenic plants. It has been reported that transgenic plants transformed withEscherichia coli TPS(trehalose‐6‐phosphatesynthase) and/orTPP(trehalose‐6‐phosphate phosphatase) are severely stunted and have root morphologic alterations. Interestingly, our transgenic sugarcane plants had no obvious morphological changes and no growth inhibition in the field. Trehalose accumulation in 35S–35S:TSase plants resulted in increased drought tolerance, as shown by the drought and the drought physiological indexes, such as the rate of bound water/free water, plasma membrane permeability, malondialdehyde content, chlorophyllaandbcontents, and activity of SOD and POD of the excised leaves. These results suggest that transgenic plants transformed with theTSasegene can accumulate high levels of trehalose and have enhanced tolerance to drought.

(Managing editor: Li‐Hui Zhao)
Genotyping the Heading Date of Male‐Sterile Rice Line II‐32A
Authors: Xu Jun‐Feng , Jiang Ling , Wei Xiang‐Jin , Zhang Wei‐Wen , Liu Shi‐Jia , Chen Liang‐Ming , Wang Chun‐Ming , Luo Lin‐Guang , Wan Jian‐Min
Published: April 2006

II‐32A, an elite male‐sterile line of rice (Oryza sativa L.), has been widely used for the production of hybrid rice seed in China. Heading date in most combinations using II‐32A shows transgressive inheritance or similarity to the latter parent, but the genotype of II‐32A with respect to major genes for heading time is unknown. This limits the further exploitation of this sterile line in breeding and hybrid seed production. Using a number of major gene heading date isogenic lines and heading date QTL near‐isogenic lines, we genetically analyzed II‐32B under both long‐ and short‐day conditions. We show that II‐32B carries two photoperiod‐sensitive genes, E1 and E3, a recessive late‐heading gene, ef‐1, and a photoperiod‐sensitive allele, Se‐1u. In addition we identified in II‐32B a recessive inhibitor for E1 or Se‐1n and other modified photoperiod‐sensitive genes. The heading‐date constitution of II‐32A was determined to be E1e2E3Se‐1uef‐1i‐Se‐1.

(Managing editor: Li‐Hui Zhao)
Genetic Analysis and Mapping of the Dominant Dwarfing Gene D‐53 in Rice
Authors: Wei Li‐Rong , Xu Ji‐Chen , Li Xiao‐Bo , Qian Qian , Zhu Li‐Huang
Published: April 2006

The dwarfing gene D‐53 is one of a few dominant genes for dwarfing in rice (Oryza sativa L.). In the present study, our genetic analysis confirmed that mutant characteristics including dwarfing, profuse tillering, thin stems and small panicles are all controlled by the dominant D‐53 gene. We measured the length of each internode of KL908, a D‐53‐carrying line, and classified the dwarfism of KL908 into the dn‐type. In addition, we measured elongation of the second sheath and α‐amylase activity in the endosperm, and we characterized KL908 as a dwarf mutant that was neither gibberellic acid‐deficient nor gibberellic acid‐insensitive. Using a large F2 population obtained by crossing KL908 with a wild‐type variety, NJ6, the D‐53 gene was mapped to the terminal region of the short arm of chromosome 11, with one simple sequence repeat marker, Ds3, co‐segregating, and the other, K81114, located 0.6 cM away.

(Managing editor: Li‐Hui Zhao)
Diversity Suppression‐Subtractive Hybridization Array for Profiling Genomic DNA Polymorphisms
Authors: Li Tong‐Xiang , Wang Jin‐Ke , Bai Yun‐Fei , Lu Zu‐Hong
Published: April 2006

Genomic DNA polymorphisms are very useful for tracing genetic traits and studying biological diversity among species. Here, we present a method we call the “diversity suppression‐subtractive hybridization array” for effectively profiling genomic DNA polymorphisms. The method first obtains the subtracted gDNA fragments between any two species by suppression subtraction hybridization (SSH) to establish a subtracted gDNA library, from which diversity SSH arrays are created with the selected subtracted clones. The diversity SSH array hybridizes with the DIG‐labeled genomic DNA of the organism to be assayed. Six closely related Dendrobium species were studied as model samples. Four Dendrobium species as testers were used to perform SSH. A total of 617 subtracted positive clones were obtained from four Dendrobium species, and the average ratio of positive clones was 80.3%. We demonstrated that the average percentage of polymorphic fragments of pairwise comparisons of four Dendrobium species was up to 42.4%. A dendrogram of the relatedness of six Dendrobium species was produced according to their polymorphic profiles. The results revealed that the diversity SSH array is a highly effective platform for profiling genomic DNA polymorphisms and dendrograms.

(Managing editor: Li‐Hui Zhao)
Evidence for the strong effect of gas removal on the internal dynamics of young stellar clusters
Authors: Bastian N. , Goodwin S. P.
Published: April 2006

We present detailed luminosity profiles of the young massive clusters M82-F, NGC 1569-A and NGC 1705-1 which show significant departures from equilibrium (King and Elson, Fall & Freeman) profiles. We compare these profiles with those from N-body simulations of clusters that have undergone the rapid removal of a significant fraction of their mass as a result of gas expulsion. We show that the observations and simulations agree very well with each other, suggesting that these young clusters are undergoing violent relaxation and are also losing a significant fraction of their stellar mass.

That these clusters are not in equilibrium can explain the discrepant mass-to-light ratios observed in many young clusters with respect to simple stellar population models without resorting to non-standard initial stellar mass functions as claimed for M82-F and NGC 1705-1. We also discuss the effect of rapid gas removal on the complete disruption of a large fraction of young massive clusters (‘infant mortality’). Finally, we note that even bound clusters may lose >50 per cent of their initial stellar mass as a result of rapid gas loss (‘infant weight-loss’).
Turbulent velocity fields in smoothed particle hydrodymanics simulated galaxy clusters: scaling laws for the turbulent energy
Authors: Vazza F. , Tormen G. , Cassano R. , Brunetti G. , Dolag K.
Published: April 2006

We present a study of the turbulent velocity fields in the intracluster medium (ICM) of a sample of 21 galaxy clusters simulated by the smoothed particle hydrodynamics code gadget2, using a new numerical scheme where the artificial viscosity is suppressed outside shocks. The turbulent motions in the ICM of our simulated clusters are detected with a novel method devised to better disentangle laminar bulk motions from chaotic ones. We focus on the scaling law between the turbulent energy content of the gas particles and the total mass, and find that the energy in the form of turbulence scales approximately with the thermal energy of clusters. We follow the evolution with time of the scaling laws and discuss the physical origin of the observed trends. The simulated data are in agreement with independent semi-analytical calculations, and the combination between the two methods allows one to constrain the scaling law over more than two decades in cluster mass.
International Purchasing: Benefits, Requirements, and Challenges
Authors: Birou Laura M. , Fawcett Stanley E.
Published: April 2006

International sourcing emerged initially as a reactive approach designed to reduce production costs in an effort to neutralize the threat of foreign competition. Today, leading edge firms have shifted the focus of their international sourcing efforts to that of a proactive strategy that pursues a sustainable competitive advantage. This article explores the challenges, requirements, and benefits of international sourcing by means of a brief literature review and a discussion of the results of a survey of purchasing managers. The study focuses on the various aspects of international sourcing that affect its ability to impact a firm's competitiveness.
Purchasing's Role in Product Development: The Case for Time‐Based Strategies
Authors: Mendez Ednardo G. , Pearson John N.
Published: April 2006

Aggressive global and domestic competition, accelerated technological advances, and market demands are catalysts in the thrusts to reduce product‐to‐market elapsed times. These developments have created the need for competitive firms to consider time‐based strategies as a potential solution to the shorter time‐to‐market requirements of today's customers. The authors suggest that purchasing can play a more active role in the new product development process through its participation in a cooperative multi‐disciplinary team approach. A team structure with the capabilities to reduce the new product development cycle is presented. In addition, the article introduces an organizational structure that facilitates purchasing's contribution to the success of time‐based product development strategies.