489 research outputs found
Taxonomic placement of Paphiopedilum rungsuriyanum (Cypripedioideae; Orchidaceae) based on morphological, cytological and molecular analyses
Additional file 9: Table S4. The comparison of main significant traits between subgenera and sections of Paphiopedilum by Gorniak et al. (2014) and the present study
Impacts of increasing typhoons on the structure and function of a subtropical forest: reflections of a changing climate
Due to their destructive and sporadic nature, it is often difficult to evaluate and predict the effects of typhoon on forest ecosystem patterns and processes. We used a 21-yr record of litterfall rates to explore the influence of typhoon frequency and intensity, along with other meteorological variables, on ecosystem dynamics in a subtropical rainforest. Over the past half century there has been an increasing frequency of strong typhoons (category 3; >49.6 m s-1; increase of 1.5 typhoons/decade) impacting the Fushan Experimental Forest, Taiwan. At Fushan strong typhoons drive total litterfall mass with an average of 1100 kg ha-1 litterfall typhoon-1. While mean typhoon season litterfall has been observed to vary by an order of magnitude, mean litterfall rates associated with annual leaf senescence vary by <20%. In response to increasing typhoon frequency, total annual litter mass increased gradually over the 21-year record following three major typhoons in 1994. Monthly maximum wind speed was predictive of monthly litterfall, yet the influence of precipitation and temperature was only evident in non-typhoon affected months. The response of this subtropical forest to strong typhoons suggests that increasing typhoon frequency has already shifted ecosystem structure and function (declining carbon sequestration and forest stature)
Differential Gene Expression in Response to Papayaringspot virus Infection in Cucumis metuliferus UsingcDNA- Amplified Fragment Length PolymorphismAnalysis
A better understanding of virus resistance mechanisms can offer more effective strategies to control virus diseases. Papayaringspot virus (PRSV), Potyviridae, causes severe economical losses in papaya and cucurbit production worldwide. However,no resistance gene against PRSV has been identified to date. This study aimed to identify candidate PRSV resistance genesusing cDNA-AFLP analysis and offered an open architecture and transcriptomic method to study those transcriptsdifferentially expressed after virus inoculation. The whole genome expression profile of Cucumis metuliferus inoculated withPRSV was generated using cDNA-amplified fragment length polymorphism (cDNA-AFLP) method. Transcript derivedfragments (TDFs) identified from the resistant line PI 292190 may represent genes involved in the mechanism of PRSVresistance. C. metuliferus susceptible Acc. 2459 and resistant PI 292190 lines were inoculated with PRSV and subsequentlytotal RNA was isolated for cDNA-AFLP analysis. More than 400 TDFs were expressed specifically in resistant line PI 292190. Atotal of 116 TDFs were cloned and their expression patterns and putative functions in the PRSV-resistance mechanism werefurther characterized. Subsequently, 28 out of 116 candidates which showed two-fold higher expression levels in resistant PI292190 than those in susceptible Acc. 2459 after virus inoculation were selected from the reverse northern blot andbioinformatic analysis. Furthermore, the time point expression profiles of these candidates by northern blot analysissuggested that they might play roles in resistance against PRSV and could potentially provide valuable information forcontrolling PRSV disease in the future
Hyperthyroidism-Associated Insulin Resistance Is Not Mediated by Adiponectin Levels
To evaluate the relationship between circulating adiponectin and insulin sensitivity in patients with hyperthyroid Graves' disease, we studied 19 adult patients with this disease and 19 age- and sex-matched euthyroid controls. All hyperthyroid patients were treated with antithyroid drugs and were re-evaluated after thyroid function normalized. Before antithyroid treatment, the adiponectin plasma concentrations were not different comparing with those in control group. The adiponectin levels remained unchanged after treatment. The homeostasis model assessment of insulin resistance (HOMA-IR) in hyperthyroid group was higher before treatment than after treatment. There was no significant difference in serum glucose and insulin levels between hyperthyroid and control groups and in the hyperthyroid group before and after treatment. BMI-adjusted adiponectin levels were not different among three groups. On the other hand, BMI-adjusted insulin levels and HOMA-IR values were significantly decreased after management of hyperthyroidism. Pearson's correlation revealed that insulin and HOMA-IR values positively correlated with triiodothyronine (T3) and free thyroxine (FT4) levels. However, adiponectin did not correlate with T3, FT4, insulin, HOMA-IR and thyrotropin receptor autoantibody (TRAb) levels. In conclusion, insulin resistance associated with hyperthyroidism is not mediated by the levels of plasma adiponectin
Lead Exposure Is Associated with Decreased Serum Paraoxonase 1 (PON1) Activity and Genotypes
Lead exposure causes cardiac and vascular damage in experimental animals. However, there is considerable debate regarding the causal relationship between lead exposure and cardiovascular dysfunction in humans. Paraoxonase 1 (PON1), a high-density lipoprotein-associated antioxidant enzyme, is capable of hydrolyzing oxidized lipids and thus protects against atherosclerosis. Previous studies have shown that lead and several other metal ions are able to inhibit PON1 activity in vitro. To investigate whether lead exposure has influence on serum PON1 activity, we conducted a cross-sectional study of workers from a lead battery manufactory and lead recycling plant. Blood samples were analyzed for whole-blood lead levels, serum PON1 activity, and three common PON1 polymorphisms (Q192R, L55M, −108C/T). The mean blood lead level (± SD) of this cohort was 27.1 ± 15 μg/dL. Multiple linear regression analysis showed that blood lead levels were significantly associated with decreased serum PON1 activity (p < 0.001) in lead workers. This negative correlation was more evident for workers who carry the R192 allele, which has been suggested to be a risk factor for coronary heart disease. Taken together, our results suggest that the decrease in serum PON1 activity due to lead exposure may render individuals more susceptible to atherosclerosis, particularly subjects who are homozygous for the R192 allele
Increased Expression of 9-Cis-Epoxycarotenoid Dioxygenase, PtNCED1, Associated With Inhibited Seed Germination in a Terrestrial Orchid, Phaius tankervilliae
The phytohormone abscisic acid (ABA) is involved in regulating seed dormancy and germination. A crucial step of ABA biosynthesis in higher plants is the oxidative cleavage of cis-epoxycarotenoids by 9-cis-epoxycarotenoid dioxygenase (NCED). Seed development in orchids is unusual because the embryos are minute in size, without obvious histodifferentiation, and lack endosperm. To understand the regulation of ABA biosynthesis in orchid seeds, we isolated and characterized a full-length cDNA encoding an NCED homolog, PtNCED1, from developing seeds of an ornamental orchid, Phaius tankervilliae. Germination percentage was high at 90 days after pollination (DAP), when a globular embryo proper with a degenerating suspensor was evident. After 90 DAP, seed maturation was accompanied by a decrease in water content and a concomitant increase in ABA content and PtNCED1 mRNA level along with a marked decrease in germination percentage. Mature seeds pretreated with NaOCl solution lowered ABA content and improved seed germination. Moreover, after seed germination, developing protocorms could respond to dehydration stress. Dehydration of protocorms stimulated an increase in PtNCED1 level along with ABA content. Our results provide evidence of the involvement of PtNCED1 in regulating endogenous ABA content in developing seeds and protocorms. The accumulation of endogenous ABA content in orchid seeds may have a critical role in seed dormancy and the protocorm response to water stress after seed germination
Early iron production in the Levant: Smelting and smithing at early 1st millennium BC Tell Hammeh, Jordan, and Tel Beth-Shemesh, Israel
The use of iron in the Near East is first attested by the sporadic occurrence of iron artefacts during the Bronze Age. By the end of the Late Bronze Age, however, use of iron metal gradually increases to such a level that one can assume a reasonably regular production of iron metal from terrestrial ores by smelting. However, very few iron metallurgical workshops or installations have been discovered in the Near East thus far. Of these, most are apparently related to secondary smithing, and very few if any have clear evidence for iron smelting. Recent fieldwork at Tell Hammeh, Jordan, identified a major iron smelting operation dated to ca. 930 Cal BC. Excavations in 2001 and 2003 at Tel Beth- Shemesh, Israel, uncovered remains of a full-scale smithing operation, dating to ca. 900 Cal BC. Dedicated excavation techniques were developed and refined for both sites, aiming at optimal recovery of both technological and archaeological information. The excavated materials were comprehensively analysed using relevant scientific analytical techniques, which included the development and application of a calibration method for quantitative bulk chemical analysis of iron- rich materials by XRF. Combining laboratory data and fieldwork, this thesis explores the particular lime- rich and iron-oxide-poor nature of the Hammeh slags as a function of the composition of the local ore and the sacrificial contribution of technical ceramics (tuyeres and furnace wall). Furthermore, it compares the smelting operations at Tell Hammeh with the smithing at Tel Beth-Shemesh, both in terms of their respective archaeological contexts as well as of their technological residues. This aims at the identification and reconstruction of the chaine operatoire of the technologies at both sites. The reconstructed technological processes are discussed in terms of their place in the socio-economic and cultural context of the early first millennium BC of the Levant. Beyond providing new data about early iron metallurgy, the integrated archaeological and laboratory approach, the excavation methods applied, the analytical methodology, as well as the archaeometric data presented here may serve as a model for the excavation, interpretation, or comparison of future (and previous) discoveries of iron metallurgy in the Near East
Recommended from our members
Molecular cytogenetic characterization of a human thyroid cancercell line
The incidence of papillary thyroid carcinoma (PTC) increases significantly after exposure of the head and neck region to ionizing radiation, yet we know neither the steps involved in malignant transformation of thyroid epithelium nor the specific carcinogenic mode of action of radiation. Such increased tumor frequency became most evident in children after the 1986 nuclear accident in Chernobyl, Ukraine. In the twelve years following the accident, the average incidence of childhood PTCs (chPTC) increased over one hundred-fold compared to the rate of about 1 tumor incidence per 10{sup 6} children per year prior to 1986. To study the etiology of radiation-induced thyroid cancer, we formed an international consortium to investigate chromosomal changes and altered gene expression in cases of post-Chernobyl chPTC. Our approach is based on karyotyping of primary cultures established from chPTC specimens, establishment of cell lines and studies of genotype-phenotype relationships through high resolution chromosome analysis, DNA/cDNA micro-array studies, and mouse xenografts that test for tumorigenicity. Here, we report the application of fluorescence in situ hybridization (FISH)-based techniques for the molecular cytogenetic characterization of a highly tumorigenic chPTC cell line, S48TK, and its subclones. Using chromosome 9 rearrangements as an example, we describe a new approach termed ''BAC-FISH'' to rapidly delineate chromosomal breakpoints, an important step towards a better understanding of the formation of translocations and their functional consequences
Access to
To evaluate the relationship between circulating adiponectin and insulin sensitivity in patients with hyperthyroid Graves' disease, we studied 19 adult patients with this disease and 19 age-and sex-matched euthyroid controls. All hyperthyroid patients were treated with antithyroid drugs and were re-evaluated after thyroid function normalized. Before antithyroid treatment, the adiponectin plasma concentrations were not different comparing with those in control group. The adiponectin levels remained unchanged after treatment. The homeostasis model assessment of insulin resistance (HOMA-IR) in hyperthyroid group was higher before treatment than after treatment. There was no significant difference in serum glucose and insulin levels between hyperthyroid and control groups and in the hyperthyroid group before and after treatment. BMI-adjusted adiponectin levels were not different among three groups. On the other hand, BMI-adjusted insulin levels and HOMA-IR values were significantly decreased after management of hyperthyroidism. Pearson's correlation revealed that insulin and HOMA-IR values positively correlated with triiodothyronine (T3) and free thyroxine (FT4) levels. However, adiponectin did not correlate with T3, FT4, insulin, HOMA-IR and thyrotropin receptor autoantibody (TRAb) levels. In conclusion, insulin resistance associated with hyperthyroidism is not mediated by the levels of plasma adiponectin
- …