Chlorophyll fluorescence analysis revealed essential roles of FtsH11 protease in regulation of the adaptive responses of photosynthetic systems to high temperature

BACKGROUND

Photosynthetic systems are known to be sensitive to high temperature stress. To maintain a relatively "normal" level of photosynthetic activities, plants employ a variety of adaptive mechanisms in response to environmental temperature fluctuations. Previously, we reported that the chloroplast-targeted AtFtsH11 protease played an essential role for Arabidopsis plants to survive at high temperatures and to maintain normal photosynthetic efficiency at moderately elevated temperature. To investigate the factors contributing to the photosynthetic changes in FtsH11 mutant, we performed detailed chlorophyll fluorescence analyses of dark-adapted mutant plants and compared them to Col-0 WT plants under normal, two moderate high temperatures, and a high light conditions.

RESULTS

We found that mutation of FtsH11 gene caused significant decreases in photosynthetic efficiency of photosystems when environmental temperature raised above optimal. Under moderately high temperatures, the FtsH11 mutant showed significant 1) decreases in electron transfer rates of photosystem II (PSII) and photosystem I (PSI), 2) decreases in photosynthetic capabilities of PSII and PSI, 3) increases in non-photochemical quenching, and a host of other chlorophyll fluorescence parameter changes. We also found that the degrees of these negative changes for utilizing the absorbed light energy for photosynthesis in FtsH11 mutant were correlated with the level and duration of the heat treatments. For plants grown under normal temperature and subjected to the high light treatment, no significant difference in chlorophyll fluorescence parameters was found between the FtsH11 mutant and Col-0 WT plants.

CONCLUSIONS

The results of this study show that AtFtsH11 is essential for normal photosynthetic function under moderately elevated temperatures. The results also suggest that the network mediated by AtFtsH11 protease plays critical roles for maintaining the thermostability and possibly structural integrity of both photosystems under elevated temperatures. Elucidating the underlying mechanisms of FtsH11 protease in photosystems may lead to improvement of photosynthetic efficiency under heat stress conditions, hence, plant productivity.

Insights Into Upland Cotton (Gossypium hirsutum L.) Genetic Recombination Based on 3 High-Density Single-Nucleotide Polymorphism and a Consensus Map Developed Independently With Common Parents

High-density linkage maps are vital to supporting the correct placement of scaffolds and gene sequences on chromosomes and fundamental to contemporary organismal research and scientific approaches to genetic improvement, especially in paleopolyploids with exceptionally complex genomes, eg, upland cotton (Gossypium hirsutum L., "2n = 52"). Three independently developed intraspecific upland mapping populations were analyzed to generate 3 high-density genetic linkage single-nucleotide polymorphism (SNP) maps and a consensus map using the CottonSNP63K array. The populations consisted of a previously reported F2, a recombinant inbred line (RIL), and reciprocal RIL population, from "Phytogen 72" and "Stoneville 474" cultivars. The cluster file provided 7417 genotyped SNP markers, resulting in 26 linkage groups corresponding to the 26 chromosomes (c) of the allotetraploid upland cotton (AD)1 arisen from the merging of 2 genomes ("A" Old World and "D" New World). Patterns of chromosome-specific recombination were largely consistent across mapping populations. The high-density genetic consensus map included 7244 SNP markers that spanned 3538 cM and comprised 3824 SNP bins, of which 1783 and 2041 were in the At and Dt subgenomes with 1825 and 1713 cM map lengths, respectively. Subgenome average distances were nearly identical, indicating that subgenomic differences in bin number arose due to the high numbers of SNPs on the Dt subgenome. Examination of expected recombination frequency or crossovers (COs) on the chromosomes within each population of the 2 subgenomes revealed that COs were also not affected by the SNPs or SNP bin number in these subgenomes. Comparative alignment analyses identified historical ancestral At-subgenomic translocations of c02 and c03, as well as of c04 and c05. The consensus map SNP sequences aligned with high congruency to the NBI assembly of Gossypium hirsutum. However, the genomic comparisons revealed evidence of additional unconfirmed possible duplications, inversions and translocations, and unbalance SNP sequence homology or SNP sequence/loci genomic dominance, or homeolog loci bias of the upland tetraploid At and Dt subgenomes. The alignments indicated that 364 SNP-associated previously unintegrated scaffolds can be placed in pseudochromosomes of the NBI G hirsutum assembly. This is the first intraspecific SNP genetic linkage consensus map assembled in G hirsutum with a core of reproducible mendelian SNP markers assayed on different populations and it provides further knowledge of chromosome arrangement of genic and nongenic SNPs. Together, the consensus map and RIL populations provide a synergistically useful platform for localizing and identifying agronomically important loci for improvement of the cotton crop.

Comparative Transcriptome and Lipidome Analyses Reveal Molecular Chilling Responses in Chilling-Tolerant Sorghums

Chilling temperatures (0 to 15°C) are a major constraint for temperate cultivation of tropical-origin crops, including the cereal crop sorghum ( [L.] Moench). Northern Chinese sorghums have adapted to early-season chilling, but molecular mechanisms of chilling tolerance are unknown. We used RNA sequencing of seedlings to compare the chilling-responsive transcriptomes of a chilling-tolerant Chinese accession with a chilling-sensitive US reference line, and mass spectrometry to compare chilling-responsive lipidomes of four chilling-tolerant Chinese accessions with two US reference lines. Comparative transcriptomics revealed chilling-induced up-regulation of cold-response regulator C-repeat binding factor (CBF) transcription factor and genes involved in reactive oxygen detoxification, jasmonic acid (JA) biosynthesis, and lipid remodeling phospholipase Dα1 (α) gene in the chilling-tolerant Chinese line. Lipidomics revealed conserved chilling-induced increases in lipid unsaturation, as well as lipid remodeling of photosynthetic membranes that is specific to chilling-tolerant Chinese accessions. Our results point to CBF-mediated transcriptional regulation, galactolipid and phospholipid remodeling, and JA as potential molecular mechanisms underlying chilling adaptation in Chinese sorghums. These molecular systems underlying chilling response could be targeted in molecular breeding for chilling tolerance.

Diversity analysis of cotton (Gossypium hirsutum L.) germplasm using the CottonSNP63K Array

BACKGROUND

Cotton germplasm resources contain beneficial alleles that can be exploited to develop germplasm adapted to emerging environmental and climate conditions. Accessions and lines have traditionally been characterized based on phenotypes, but phenotypic profiles are limited by the cost, time, and space required to make visual observations and measurements. With advances in molecular genetic methods, genotypic profiles are increasingly able to identify differences among accessions due to the larger number of genetic markers that can be measured. A combination of both methods would greatly enhance our ability to characterize germplasm resources. Recent efforts have culminated in the identification of sufficient SNP markers to establish high-throughput genotyping systems, such as the CottonSNP63K array, which enables a researcher to efficiently analyze large numbers of SNP markers and obtain highly repeatable results. In the current investigation, we have utilized the SNP array for analyzing genetic diversity primarily among cotton cultivars, making comparisons to SSR-based phylogenetic analyses, and identifying loci associated with seed nutritional traits.

RESULTS

The SNP markers distinctly separated G. hirsutum from other Gossypium species and distinguished the wild from cultivated types of G. hirsutum. The markers also efficiently discerned differences among cultivars, which was the primary goal when designing the CottonSNP63K array. Population structure within the genus compared favorably with previous results obtained using SSR markers, and an association study identified loci linked to factors that affect cottonseed protein content.

CONCLUSIONS

Our results provide a large genome-wide variation data set for primarily cultivated cotton. Thousands of SNPs in representative cotton genotypes provide an opportunity to finely discriminate among cultivated cotton from around the world. The SNPs will be relevant as dense markers of genome variation for association mapping approaches aimed at correlating molecular polymorphisms with variation in phenotypic traits, as well as for molecular breeding approaches in cotton.

Genome-wide association analysis of seedling traits in diverse Sorghum germplasm under thermal stress

BACKGROUND

Climate variability due to fluctuation in temperature is a worldwide concern that imperils crop production. The need to understand how the germplasm variation in major crops can be utilized to aid in discovering and developing breeding lines that can withstand and adapt to temperature fluctuations is more necessary than ever. Here, we analyzed the genetic variation associated with responses to thermal stresses in a sorghum association panel (SAP) representing major races and working groups to identify single nucleotide polymorphisms (SNPs) that are associated with resilience to temperature stress in a major cereal crop.

RESULTS

The SAP exhibited extensive variation for seedling traits under cold and heat stress. Genome-wide analyses identified 30 SNPs that were strongly associated with traits measured at seedling stage under cold stress and tagged genes that act as regulators of anthocyanin expression and soluble carbohydrate metabolism. Meanwhile, 12 SNPs were significantly associated with seedling traits under heat stress and these SNPs tagged genes that function in sugar metabolism, and ion transport pathways. Evaluation of co-expression networks for genes near the significantly associated SNPs indicated complex gene interactions for cold and heat stresses in sorghum. We focused and validated the expression of four genes in the network of Sb06g025040, a basic-helix-loop-helix (bHLH) transcription factor that was proposed to be involved in purple color pigmentation of leaf, and observed that genes in this network were upregulated during cold stress in a moderately tolerant line as compared to the more sensitive line.

CONCLUSION

This study facilitated the tagging of genome regions associated with variation in seedling traits of sorghum under cold and heat stress. These findings show the potential of genotype information for development of temperature resilient sorghum cultivars and further characterization of genes and their networks responsible for adaptation to thermal stresses. Knowledge on the gene networks from this research can be extended to the other cereal crops to better understand the genetic basis of resilience to temperature fluctuations during plant developmental stages.

Technology Skills in the Workplace: Information Professionals’ Current Use and Future Aspirations

Information technology serves as an essential tool for today's information professional, with a need for ongoing research attention to assess the technological directions of the field over time. This paper presents the results of a survey of the technologies used by library and information science (LIS) practitioners, with attention to the combinations of technologies employed and the technology skills that practitioners wish to learn.  The most common technologies employed were: email, office productivity tools, web browsers, library catalog and database searching tools, and printers, with programming topping the list of most-desired technology skill to learn. Generally similar technology usage patterns were observed for early and later-career practitioners. Findings also suggested the relative rarity of emerging technologies, such as the makerspace, in current practice.

Diversion and Illicit Sale of Extended Release Tapentadol in the United States

OBJECTIVE

Prescription opioid analgesics are commonly prescribed for moderate to severe pain. An unintended consequence of prescribing opioid analgesics is the abuse and diversion of these medications. Tapentadol ER is a recently approved centrally acting analgesic with synergistic mechanisms of action: μ-opioid receptor agonism and inhibition of norepinephrine reuptake. We assessed the amount of diversion and related cost of obtaining tapentadol IR (Nucynta®) and tapentadol ER (Nucynta ER®) as well as other Schedule II opioid medications in street transactions in the United States using the Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS®) System.

METHODS

The Drug Diversion Program measures the number of cases opened by 260 drug diversion investigators in 49 states. StreetRx(TM) uses a crowd-sourcing Website to collect the prices paid for licit or illicit drugs.

RESULTS

The population-based rates of diversion were 0.003 (tapentadol IR), 0.001 (tapentadol ER), and 1.495 (other Schedule II opioid tablets) reports per 100,000 population. The tapentadol ER rate was lower than the other Schedule II opioid tablets (P < 0.001) and tapentadol IR (P= 0.004). Diversion rates based on drug availability were 0.03 (tapentadol IR), 0.016 (tapentadol ER), and 0.172 (other Schedule II opioid tablets) per 1,000 prescriptions dispensed. The median street price per milligram was $0.18 (tapentadol IR), $0.10 (tapentadol ER), and $1.00 (other Schedule II opioid tablets).

DISCUSSION

Our results indicate that tapentadol ER is rarely sold illicitly in the United States. When sold illicitly, tapentadol ER costs less than other Schedule II opioid products.

AtRAV1 and AtRAV2 overexpression in cotton increases fiber length differentially under drought stress and delays flowering

There is a longstanding problem of an inverse relationship between cotton fiber qualities versus high yields. To better understand drought stress signaling and adaptation in cotton (Gossypium hirsutum) fiber development, we expressed the Arabidopsis transcription factors RELATED_TO_ABA-INSENSITIVE3/VIVIPAROUS1/(RAV1) and AtRAV2, which encode APETALA2-Basic3 domain proteins shown to repress transcription of FLOWERING_LOCUS_T (FT) and to promote stomatal opening cell-autonomously. In three years of field trials, we show that AtRAV1 and AtRAV2-overexpressing cotton had ∼5% significantly longer fibers with only marginal decreases in yields under well-watered or drought stress conditions that resulted in 40-60% yield penalties and 3-7% fiber length penalties in control plants. The longer transgenic fibers from drought-stressed transgenics could be spun into yarn which was measurably stronger and more uniform than that from well-watered control fibers. The transgenic AtRAV1 and AtRAV2 lines flowered later and retained bolls at higher nodes, which correlated with repression of endogenous GhFT-Like (FTL) transcript accumulation. Elevated expression early in development of ovules was observed for GhRAV2L, GhMYB25-Like (MYB25L) involved in fiber initiation, and GhMYB2 and GhMYB25 involved in fiber elongation. Altered expression of RAVs controlling critical nodes in developmental and environmental signaling hierarchies has the potential for phenotypic modification of crops.

Natural Variation in Synthesis and Catabolism Genes Influences Dhurrin Content in Sorghum

Cyanogenic glucosides are natural compounds found in more than 1000 species of angiosperms that produce HCN and are deemed undesirable for agricultural use. However, these compounds are important components of the primary defensive mechanisms of many plant species. One of the best-studied cyanogenic glucosides is dhurrin [(S)-p-hydroxymandelonitrile-β-D-glucopyranoside], which is produced primarily in sorghum [Sorghum bicolor (L.) Moench]. The biochemical basis for dhurrin metabolism is well established; however, little information is available on its genetic control. Here, we dissect the genetic control of leaf dhurrin content through a genome-wide association study (GWAS) using a panel of 700 diverse converted sorghum lines (conversion panel) previously subjected to pre-breeding and selected for short stature (∼1 m in height) and photoperiod insensitivity. The conversion panel was grown for 2 yr in three environments. Wide variation for leaf dhurrin content was found in the sorghum conversion panel, with the Caudatum group exhibiting the highest dhurrin content and the Guinea group showing the lowest dhurrin content. A GWAS using a mixed linear model revealed significant associations (a false discovery rate [FDR] < 0.05) close to both UGT 185B1 in the canonical biosynthetic gene cluster on chromosome 1 and close to the catabolic dhurrinase loci on chromosome 8. Dhurrin content was associated consistently with biosynthetic genes in the two N-fertilized environments, while dhurrin content was associated with catabolic loci in the environment without supplemental N. These results suggest that genes for both biosynthesis and catabolism are important in determining natural variation for leaf dhurrin in sorghum in different environments.

Developing fiber specific promoter-reporter transgenic lines to study the effect of abiotic stresses on fiber development in cotton

Cotton is one of the most important cash crops in US agricultural industry. Environmental stresses, such as drought, high temperature and combination of both, not only reduce the overall growth of cotton plants, but also greatly decrease cotton lint yield and fiber quality. The impact of environmental stresses on fiber development is poorly understood due to technical difficulties associated with the study of developing fiber tissues and lack of genetic materials to study fiber development. To address this important question and provide the need for scientific community, we have generated transgenic cotton lines harboring cotton fiber specific promoter (CFSP)-reporter constructs from six cotton fiber specific genes (Expansin, E6, Rac13, CelA1, LTP, and Fb late), representing genes that are expressed at different stages of fiber development. Individual CFSP::GUS or CFSP::GFP construct was introduced into Coker 312 via Agrobacterium mediated transformation. Transgenic cotton lines were evaluated phenotypically and screened for the presence of selectable marker, reporter gene expression, and insertion numbers. Quantitative analysis showed that the patterns of GUS reporter gene activity during fiber development in transgenic cotton lines were similar to those of the native genes. Greenhouse drought and heat stress study showed a correlation between the decrease in promoter activities and decrease in fiber length, increase in micronaire and changes in other fiber quality traits in transgenic lines grown under stressed condition. These newly developed materials provide new molecular tools for studying the effects of abiotic stresses on fiber development and may be used in study of cotton fiber development genes and eventually in the genetic manipulation of fiber quality.

Development of a 63K SNP Array for Cotton and High-Density Mapping of Intraspecific and Interspecific Populations of Gossypium spp

High-throughput genotyping arrays provide a standardized resource for plant breeding communities that are useful for a breadth of applications including high-density genetic mapping, genome-wide association studies (GWAS), genomic selection (GS), complex trait dissection, and studying patterns of genomic diversity among cultivars and wild accessions. We have developed the CottonSNP63K, an Illumina Infinium array containing assays for 45,104 putative intraspecific single nucleotide polymorphism (SNP) markers for use within the cultivated cotton species Gossypium hirsutum L. and 17,954 putative interspecific SNP markers for use with crosses of other cotton species with G. hirsutum. The SNPs on the array were developed from 13 different discovery sets that represent a diverse range of G. hirsutum germplasm and five other species: G. barbadense L., G. tomentosum Nuttal × Seemann, G. mustelinum Miers × Watt, G. armourianum Kearny, and G. longicalyx J.B. Hutchinson and Lee. The array was validated with 1,156 samples to generate cluster positions to facilitate automated analysis of 38,822 polymorphic markers. Two high-density genetic maps containing a total of 22,829 SNPs were generated for two F2 mapping populations, one intraspecific and one interspecific, and 3,533 SNP markers were co-occurring in both maps. The produced intraspecific genetic map is the first saturated map that associates into 26 linkage groups corresponding to the number of cotton chromosomes for a cross between two G. hirsutum lines. The linkage maps were shown to have high levels of collinearity to the JGI G. raimondii Ulbrich reference genome sequence. The CottonSNP63K array, cluster file and associated marker sequences constitute a major new resource for the global cotton research community.

Enhancement of reproductive heat tolerance in plants

Comparison of average crop yields with reported record yields has shown that major crops exhibit annual average yields three- to seven-fold lower than record yields because of unfavorable environments. The current study investigated the enhancement of pollen heat tolerance through expressing an Arabidopsis thaliana heat shock protein 101 (AtHSP101) that is not normally expressed in pollen but reported to play a crucial role in vegetative thermotolerance. The AtHSP101 construct under the control of the constitutive ocs/mas 'superpromoter' was transformed into cotton Coker 312 and tobacco SRI lines via Agrobacterium mediated transformation. Thermotolerance of pollen was evaluated by in vitro pollen germination studies. Comparing with those of wild type and transgenic null lines, pollen from AtHSP101 transgenic tobacco and cotton lines exhibited significantly higher germination rate and much greater pollen tube elongation under elevated temperatures or after a heat exposure. In addition, significant increases in boll set and seed numbers were also observed in transgenic cotton lines exposed to elevated day and night temperatures in both greenhouse and field studies. The results of this study suggest that enhancing heat tolerance of reproductive tissues in plant holds promise in the development of crops with improved yield production and yield sustainability in unfavorable environments.

Overexpression of MIC-3 indicates a direct role for the MIC gene family in mediating Upland cotton (Gossypium hirsutum) resistance to root-knot nematode (Meloidogyne incognita)

Transgene-based analysis of the MIC-3 gene provides the first report of a cotton gene having a direct role in mediating cotton resistance to root-knot nematode. Major quantitative trait loci have been mapped to Upland cotton (Gossypium hirsutum L.) chromosomes 11 and 14 that govern the highly resistant phenotype in response to infection by root-knot nematode (RKN; Meloidogyne incognita); however, nearly nothing is known regarding the underlying molecular determinants of this RKN-resistant phenotype. Multiple lines of circumstantial evidence have strongly suggested that the MIC (Meloidogyne Induced Cotton) gene family plays an integral role in mediating cotton resistance to RKN. In this report, we demonstrate that overexpression of MIC-3 in the RKN-susceptible genetic background Coker 312 reduces RKN egg production by ca. 60-75 % compared to non-transgenic controls and transgene-null sibling lines. MIC-3 transcript and protein overexpression were confirmed in root tissues of multiple independent transgenic lines with each line showing a similar level of increased resistance to RKN. In contrast to RKN fecundity, transgenic lines showed RKN-induced root galling similar to the susceptible controls. In addition, we determined that this effect of MIC-3 overexpression was specific to RKN as no effect was observed on reniform nematode (Rotylenchulus reniformis) reproduction. Transgenic lines did not show obvious alterations in growth, morphology, flowering, or fiber quality traits. Gene expression analyses showed that MIC-3 transcript levels in uninfected transgenic roots exceeded levels observed in RKN-infected roots of naturally resistant plants and that overexpression did not alter the regulation of native MIC genes in the genome. These results are the first report describing a direct role for a specific gene family in mediating cotton resistance to a plant-parasitic nematode.

One-pot conversion of cellobiose to mannose using a hybrid phosphotungstic acid–cerium oxide catalyst

Two-step conversion of cellobiose to mannose using hybrid catalyst.

Mapping genomic loci for cotton plant architecture, yield components, and fiber properties in an interspecific (Gossypium hirsutum L. × G. barbadense L.) RIL population

A quantitative trait locus (QTL) mapping was conducted to better understand the genetic control of plant architecture (PA), yield components (YC), and fiber properties (FP) in the two cultivated tetraploid species of cotton (Gossypium hirsutum L. and G. barbadense L.). One hundred and fifty-nine genomic regions were identified on a saturated genetic map of more than 2,500 SSR and SNP markers, constructed with an interspecific recombinant inbred line (RIL) population derived from the genetic standards of the respective cotton species (G. hirsutum acc. TM-1 × G. barbadense acc. 3-79). Using the single nonparametric and MQM QTL model mapping procedures, we detected 428 putative loci in the 159 genomic regions that confer 24 cotton traits in three diverse production environments [College Station F&B Road (FB), TX; Brazos Bottom (BB), TX; and Shafter (SH), CA]. These putative QTL loci included 25 loci for PA, 60 for YC, and 343 for FP, of which 3, 12, and 60, respectively, were strongly associated with the traits (LOD score ≥ 3.0). Approximately 17.7 % of the PA putative QTL, 32.9 % of the YC QTL, and 48.3 % of the FP QTL had trait associations under multiple environments. The At subgenome (chromosomes 1-13) contributed 72.7 % of loci for PA, 46.2 % for YC, and 50.4 % for FP while the Dt subgenome (chromosomes 14-26) contributed 27.3 % of loci for PA, 53.8 % for YC, and 49.6 % for FP. The data obtained from this study augment prior evidence of QTL clusters or gene islands for specific traits or biological functions existing in several non-homoeologous cotton chromosomes. DNA markers identified in the 159 genomic regions will facilitate further dissection of genetic factors underlying these important traits and marker-assisted selection in cotton.

Related to ABA-Insensitive3(ABI3)/Viviparous1 and AtABI5 transcription factor coexpression in cotton enhances drought stress adaptation

Drought tolerance is an important trait being pursued by the agbiotech industry. Abscisic acid (ABA) is a stress hormone that mediates a multitude of processes in growth and development, water use efficiency (WUE) and gene expression during seed development and in response to environmental stresses. Arabidopsis B3-domain transcription factor Related to ABA-Insensitive3 (ABI3)/Viviparous1 (namely AtRAV2) and basic leucine zipper (bZIPs) AtABI5 or AtABF3 transactivated ABA-inducible promoter:GUS reporter expression in a maize mesophyll protoplast transient assay and showed synergies in reporter transactivation when coexpressed. Transgenic cotton (Gossypium hirsutum) expressing AtRAV1/2 and/or AtABI5 showed resistance to imposed drought stress under field and greenhouse conditions and exhibited improved photosynthesis and WUEs associated with absorption through larger root system and greater leaf area. We observed synergy for root biomass accumulation in the greenhouse, intrinsic WUE in the field and drought tolerance in stacked AtRAV and AtABI5 double-transgenic cotton. We assessed AtABI5 and AtRAV1/2 involvement in drought stress adaptations through reactive oxygen species scavenging and osmotic adjustment by marker gene expression in cotton. Deficit irrigation-grown AtRAV1/2 and AtABI5 transgenics had 'less-stressed' molecular and physiological phenotypes under drought, likely due to improved photoassimilation and root and shoot sink strengths and enhanced expression of endogenous GhRAV and genes for antioxidant and osmolyte biosynthesis. Overexpression of bZIP and RAV TFs could impact sustainable cotton agriculture and potentially other crops under limited irrigation conditions.

Prescription drugs purchased through the internet: who are the end users?

Although prescription drugs are readily available on the Internet, little is known about the prevalence of Internet use for the purchase of medications without a legitimate prescription, and the characteristics of those that obtain non-prescribed drugs through online sources. The scientific literature on this topic is limited to anecdotal reports or studies plagued by small sample sizes. Within this context, the focus of this paper is an examination of five national data sets from the U.S. with the purpose of estimating: (1) how common obtaining prescription medications from the Internet actually is, (2) who are the typical populations of "end users" of these non-prescribed medications, and (3) which drugs are being purchased without a prescription. Three of the data sets are drawn from the RADARS (Researched Abuse Diversion and Addiction-Related Surveillance) System, a comprehensive series of studies designed to collect timely and geographically specific data on the abuse and diversion of a number of prescription stimulants and opioid analgesics. The remaining data sets include the National Survey on Drug Use and Health (NSDUH) and the Monitoring the Future (MTF) survey. Our analysis yielded uniformly low rates of prescription drug acquisition from online sources across all five data systems we examined. The consistency of this finding across very diverse populations suggests that the Internet is a relatively minor source for illicit purchases of prescription medications by the individual end-users of these drugs.

Plant lipidomics: Discerning biological function by profiling plant complex lipids using mass spectrometry

Since 2002, plant biologists have begun to apply mass spectrometry to the comprehensive analysis of complex lipids. Such lipidomic analyses have been used to uncover roles for lipids in plant response to stresses and to identify in vivo functions of genes involved in lipid metabolism.

Evaluation of source leaf responses to water-deficit stresses in cotton using a novel stress bioassay

Water-deficit stresses preferentially reduce shoot growth, thereby disrupting the flow of carbohydrates from source leaves to the developing sinks. Here, we use a novel stress bioassay to dissect responses of field and greenhouse-grown cotton (Gossypium hirsutum) source leaves to water-deficit stresses. Fifth main stem leaf samples were harvested at sunrise and subjected to a prolonged elevated respiratory demand in the dark. Sucrose levels are lower in nonstressed cotton at sunrise compared to water-deficit stressed cotton, potentially predisposing the nonstressed tissue to succumb more rapidly. Tissue death was determined initially using the cell viability stain 2,3,5-triphenyltetrazolium chloride, but was determined in subsequent experiments by monitoring the decline in chlorophyll fluorescence yield. Fluorescence yield measurements were obtained within minutes of harvesting and individual samples were monitored over the time course of the treatment. Analyses of the time course and magnitude of chlorophyll fluorescence yield decline in samples from irrigated and dryland plots permitted the detection of stress responses within 24 h of the cessation of irrigation. The rate of fluorescence yield decline during the elevated respiratory demand treatment slowed as the water-deficit stress increased. Upon irrigation, the source leaves of the water-stressed plants recovered to prestress values within 4 d. Well-watered cotton overexpressing heat shock protein 101 had identical rates of fluorescence yield decline as nontransgenic cotton. These results suggest that the delayed decline in fluorescence yield of water-stressed tissue exposed to prolonged elevated respiratory demand can be used as a sensitive indicator of water-deficit stress responses.

FtsH11 protease plays a critical role in Arabidopsis thermotolerance

Plants, as sessile organisms, employ multiple mechanisms to adapt to the seasonal and daily temperature fluctuations associated with their habitats. Here, we provide genetic and physiological evidence that the FtsH11 protease of Arabidopsis contributes to the overall tolerance of the plant to elevated temperatures. To identify the various mechanisms of thermotolerance in plants, we isolated a series of Arabidopsis thaliana thermo-sensitive mutants (atts) that fail to acquire thermotolerance after pre-conditioning at 38 degrees C. Two allelic mutants, atts244 and atts405, were found to be both highly susceptible to moderately elevated temperatures and defective in acquired thermotolerance. The growth and development of the mutant plants at all stages examined were arrested after exposure to temperatures above 30 degrees C, which are permissive conditions for wild-type plants. The affected gene in atts244 was identified through map-based cloning and encodes a chloroplast targeted FtsH protease, FtsH11. The Arabidopsis genome contains 12 predicted FtsH protease genes, with all previously characterized FtsH genes playing roles in the alleviation of light stress through the degradation of unassembled thylakoid membrane proteins and photodamaged photosystem II D1 protein. Photosynthetic capability, as measured by chlorophyll content (chl a/b ratios) and PSII quantum yield, is greatly reduced in the leaves of FtsH11 mutants when exposed to the moderately high temperature of 30 degrees C. Under high light conditions, however, FtsH11 mutants and wild-type plants showed no significant difference in photosynthesis capacity. Our results support a direct role for the A. thaliana FtsH11-encoded protease in thermotolerance, a function previously reported for bacterial and yeast FtsH proteases but not for those from plants.

Characterization of the Arabidopsis thermosensitive mutant atts02 reveals an important role for galactolipids in thermotolerance

Plants are constantly challenged with various abiotic stresses in their natural environment. Elevated temperatures have a detrimental impact on overall plant growth and productivity. Many plants increase their tolerance to high temperatures through an adaptation response known as acquired thermotolerance. To identify the various mechanisms that plants have evolved to cope with high temperature stress, we have isolated a series of Arabidopsis mutants that are defective in the acquisition of thermotolerance after an exposure to 38 degrees C, a treatment that induces acquired thermotolerance in wild-type plants. One of these mutants, atts02, was not only defective in acquiring thermotolerance after the treatment, but also displayed a reduced level of basal thermotolerance in a 30 degrees C growth assay. The affected gene in atts02 was identified by positional cloning and encodes digalactosyldiacylglycerol synthase 1 (DGD1) (the atts02 mutant was, at that point, renamed dgd1-2). An additional dgd1 allele, dgd1-3, was identified in two other mutant lines displaying altered acquired thermotolerance, atts100 and atts104. Expression patterns of several heat shock proteins (HSPs) in heat-treated dgd1-2 homozygous plants were similar to those from identically treated wild-type plants, suggesting that the thermosensitivity in the dgd1-2 mutant was not caused by a defect in HSP induction. Lipid analysis of wild-type and mutant plants indicated a close correlation between the ability to acquire thermotolerance and the increases in digalactosyldiacylglycerol (DGDG) level and in the ratio of DGDG to monogalactosyldiacylglycerol (MGDG). Thermosensitivity in dgd1-2 and dgd1-3 was associated with (1) a decreased DGDG level and (2) an inability to increase the ratio of DGDG to MGDG upon exposure to a 38 degrees C sublethal temperature treatment. Our results suggest that the DGDG level and/or the ratio of DGDG to MGDG may play an important role in basal as well as acquired thermotolerance in Arabidopsis.

The diversion of prescription drugs by health care workers in Cincinnati, Ohio

Data are reported from drug diversion cases involving health care workers who were investigated by the Cincinnati Police Division Pharmaceutical Diversion Squad over an 11-year period. This type of information is rarely available because few U.S. police jurisdictions dedicate resources to prescription drug diversion surveillance. Data from 1992 through 2002 show that opioids were the drugs most commonly diverted by health care workers, followed by benzodiazepines. Nurses, nursing assistants, and medical assistants were involved in almost three quarters of all cases. Hospitals were the most common sources of complaint to police, followed by pharmacies. Health care professional associations are advised to promote greater awareness of drug misuse and dependence concerns among their memberships, and health care facilities that stock pharmaceuticals liable for misuse and diversion are advised to increase the security of their supplies.

High-throughput DNA extraction method suitable for PCR

PCR has become one of the most popular techniques in functional genomics. Projects in both forward and reverse genetics routinely require PCR amplification of thousands of samples. Processing samples to extract DNA of sufficient purity for PCR is often a limiting step. We have developed a simple 96-well plate-based high-throughput DNA extraction method that is applicable to many plant species. The method involves a simple incubation of plant tissue samples in a DNA extraction buffer followed by a neutralization step. With the addition of a modified PCR buffer, the extracted DNA enabled the robust amplification of genomic fragments from samples of Arabidopsis, tobacco, sorghum, cotton, moss, and even pine needles. Several thousand DNA samples can be economically processed in a single day by one person without the use of robotics. This procedure will facilitate many technologies including high-throughput genotyping, map-based cloning, and identification of T-DNA or transposon-tagged mutants for known gene sequences.

Recurrent ascites and pleural effusions after surgery for early-stage endometrial adenocarcinoma

A case of massive postoperative ascites in a woman treated for endometrial cancer is reported. A workup for typical causes of ascites yielded negative results, prompting a more detailed analysis of the patient's condition. Hypothyroidism was discovered. After correction of the hypothyroidism, the ascites slowly resolved. Since myxedema is an uncommon cause of ascites, this is usually a diagnosis of exclusion. However, hypothyroidism must be ruled out to prevent unnecessary and possibly inappropriate treatments for ascites.

Isolation of Arabidopsis mutants lacking components of acquired thermotolerance

Acquired thermotolerance is a complex physiological phenomenon that enables plants to survive normally lethal temperatures. This study characterizes the temperature sensitivity of Arabidopsis using a chlorophyll accumulation bioassay, describes a procedure for selection of acquired thermotolerance mutants, and provides the physiological characterization of one mutant (AtTS02) isolated by this procedure. Exposure of etiolated Arabidopsis seedlings to 48 degrees C or 50 degrees C for 30 min blocks subsequent chlorophyll accumulation and is eventually lethal. Arabidopsis seedlings can be protected against the effects of a 50 degrees C, 30-min challenge by a 4-h pre-incubation at 38 degrees C. By the use of the milder challenge, 44 degrees C for 30 min, and protective pretreatment, mutants lacking components of the acquired thermotolerance system were isolated. Putative mutants isolated by this procedure exhibited chlorophyll accumulation levels (our measure of acquired thermotolerance) ranging from 10% to 98% of control seedling levels following pre-incubation at 38 degrees C and challenge at 50 degrees C. The induction temperatures for maximum acquired thermotolerance prior to a high temperature challenge were the same in AtTS02 and RLD seedlings, although the absolute level of chlorophyll accumulation was reduced in the mutant. Genetic analysis showed that the loss of acquired thermotolerance in AtTS02 was a recessive trait. The pattern of proteins synthesized at 25 degrees C and 38 degrees C in the RLD and AtTS02 revealed the reduction in the level of a 27-kD heat shock protein in AtTS02. Genetic analysis showed that the reduction of this protein level was correlated with the acquired thermotolerance phenotype.

Regulation of PTP1D mRNA by peptide growth factors in the human endometrial cell line HEC-1-A

OBJECTIVE

To assess, in the human endometrial cell line HEC-1-A, the presence of protein tyrosine phosphatase 1D (PTP1D) and the possible regulation of its mRNA expression by mitogens such as forskolin (an agent that increases intracellular cyclic adenosine monophosphate [cAMP] levels), epidermal growth factor (EGF), and insulin-like growth factor-I (IGF-I).

METHODS

Cells were grown to confluence and maintained in serum-free media for 24 hours before treatment. Cells were exposed to forskolin, EGF, and IGF-I for increasing time periods (0, 1, 3, 6, and 24 hours), and PTP1D mRNA expression was determined by Northern blot analysis. In addition, cells were incubated with increasing doses of forskolin (final concentrations: 1, 5, 10, 20, and 30 mumol/L) for 6 hours.

RESULTS

When treated with the various mitogens, cells increased their stimulation of PTP1D mRNA expression in a time- and dose-dependent fashion. Specifically, forskolin, EGF, and IGF-I induced maximal mRNA expression at 6, 3, and 6 hours, respectively. Expression induced by forskolin, EGF, and IGF-I was five, three, and six times control levels, respectively. At a dose of 10 mumol/L, forskolin induced PTP1D mRNA expression almost two times higher than control values.

CONCLUSION

These data suggest that in human endometrial carcinomas, cAMP, EGF, and IGF-I may regulate the expression of PTP1D mRNA, which may, in turn, play a role in uncontrolled cell proliferation and neoplastic transformation.

70-nm-bandwidth achromatic waveguide coupler

We report a general approach to the design of broadband waveguide couplers. A double-parallel grating assembly is used to cancel the first chromatic order, and a proper choice of prism glass and base angle is made to compensate for the second chromatic order. The technique was applied to a Corning glass 7059 waveguide, and a spectral bandwidth of 70 nm was measured by the use of two complementary procedures.

Wet-chemical fabrication of a single leakage-channel grating coupler

We demonstrate the fabrication of a unique optical device, the single leakage-channel grating coupler, using solgel techniques. Design specifications are outlined to establish the material criteria for the sol-gel compositions. Material choice and preparation are described. We evaluate the characteristics and performance of the single leakage-channel grating coupler by comparing the predicted and the measured branching ratios. The branching ratio of the solution-derived device is within 3% of the theoretically predicted value.

Design and fabrication of a single leakage-channel grating coupler

We describe the modeling and fabrication of waveguide grating couplers with theoretical outcoupling efficiencies into a single diffracted order nearing 100%. Termed single leakage-channel grating couplers (or SLCGC's), these devices utilize a high-reflectivity dielectric stack to reflect the outcoupled beam diffracted toward the substrate and back up into the air region, where it constructively adds with the beam diffracted into the air region. Computer modeling shows that the branching ratio and the leakage rate can be independently controlled, and that the branching ratio is independent of grating depth and grating period. A SLCGC with a branching ratio of 97.1% is fabricated by the use of a combination of vacuum-evaporation and wet-chemical techniques.

Inhibition of tobacco NADH-hydroxypyruvate reductase by expression of a heterologous antisense RNA derived from a cucumber cDNA: implications for the mechanism of action of antisense RNAs

Tobacco plants were genetically transformed to generate antisense RNA from a gene construct comprised of a full-length cucumber NADH-dependent hydroxypyruvate reductase (HPR) cDNA placed in reverse orientation between the cauliflower mosaic virus 35S promoter and a nopaline synthase termination/polyadenylation signal sequence. In vivo accumulation of antisense HPR RNA within eight independent transgenic tobacco plants resulted in reductions of up to 50% in both native HPR activity and protein accumulation relative to untransformed tobacco plants (mean transgenote HPR activity = 67% wild type, mean transgenote HPR protein = 63% wild type). However, in contrast to previous reports describing antisense RNA effects in plants, production of the heterologous HPR antisense RNA did not systematically reduce levels of native tobacco HPR mRNA (mean transgenote HPR mRNA level = 135% wild type). Simple regression comparison of the steady-state levels of tobacco HPR mRNA to those of HPR antisense RNA showed a weak positive correlation (r value of 0.548, n = 9; n is wild type control plus eight independent transformants; significant at 85% confidence level), supporting the conclusion that native mRNA levels were not reduced within antisense plants. Although all transgenic antisense plants examined displayed an apparent reduction in both tobacco HPR protein and enzyme activity, there is no clear correlation between HPR activity and the amount of either sense (r = 0.267, n = 9) or antisense RNA (r = 0.175, n = 9). This compares to a weak positive correlation between HPR mRNA levels and the amount of HPR activity observed in wild-type SR1 tobacco plants (r = 0.603, n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)

Gaussian beams from variable groove depth grating couplers in planar waveguides

Analysis, fabrication, and characterization of variable groove depth planar waveguide grating couplers are presented. A formula is derived to describe the grating groove depth variation necessary to produce an outcoupled beam of arbitrary profile. A variable depth grating for producing a Gaussian beam profile is fabricated on a waveguide by ion-beam etching through a scanning slit apparatus. A photoresist grating placed on the waveguide provides a mask to define the grating etched onto the waveguide. The near-field irradiance of the outcoupled beam is measured and shown to approach a Gaussian profile.

Increased resistance to oxidative stress in transgenic plants that overexpress chloroplastic Cu/Zn superoxide dismutase

Transgenic tobacco plants that express a chimeric gene that encodes chloroplast-localized Cu/Zn superoxide dismutase (SOD) from pea have been developed. To investigate whether increased expression of chloroplast-targeted SOD could alter the resistance of photosynthesis to environmental stress, these plants were subjected to chilling temperatures and moderate (500 mumol of quanta per m2 per s) or high (1500 mumol of quanta per m2 per s) light intensity. During exposure to moderate stress, transgenic SOD plants retained rates of photosynthesis approximately 20% higher than untransformed tobacco plants, implicating active oxygen species in the reduction of photosynthesis during chilling. Unlike untransformed plants, transgenic SOD plants were capable of maintaining nearly 90% of their photosynthetic capacity (determined by their photosynthetic rates at 25 degrees C) following exposure to chilling at high light intensity for 4 hr. These plants also showed reduced levels of light-mediated cellular damage from the superoxide-generating herbicide methyl viologen. These results demonstrate that SOD is a critical component of the active-oxygen-scavenging system of plant chloroplasts and indicate that modification of SOD expression in transgenic plants can improve plant stress tolerance.

Differential temperature sensitivity of pea superoxide dismutases

The activity of pea (Pisum sativum L.) Cu/Zn and Mn superoxide dismutase isoforms was evaluated across a range of temperatures from 10 to 45 degrees C. Maximal activity of the Cu/Zn and Mn superoxide dismutase isoforms was observed at 10 degrees C. Both cytoplasmic and chloroplast Cu/Zn superoxide dismutases exhibit a reduction in staining intensity with increasing temperatures. Mn superoxide dismutase, however, maintained a relatively constant staining intensity across the range of temperatures evaluated. An unrelated enzyme used as a control, malate dehydrogenase, exhibited the expected increase in staining activity with increasing temperatures. These results describe a unique response of a protection enzyme to temperature.

Linear propagation characteristics of periodically segmented waveguides

Periodically segmented planar waveguides are modeled by using the rigorous modal method of diffraction gratings. The radiation loss, effective index, and electric-field strength distribution are analyzed for different segment duty cycles. It is shown that except for the low radiation loss and possible presence of stop bands, a segmented waveguide behaves much like a uniform waveguide. The theoretical calculation confirms the low radiation loss observed experimentally.

A new method of measuring protein-methionine-s-oxide reductase activity

A new assay for measuring protein-methionine-S-oxide reductase is reported. The assay measures the conversion of N-(9-fluorenylmethoxycarbonyl)-methionine sulfoxide to N-(9-fluorenylmethoxycarbonyl)-methionine using fluorescence detection after high-performance liquid chromatography separation. Enzyme activity is linear over a 60-min period and the assay is sensitive enough to detect the consumption of only 1% of available substrate. Protein-methionine-S-oxide reductase activity was demonstrated in pea (Pisum sativum L.) chloroplasts, and enzyme levels in leaves of etiolated and light-grown seedlings were compared.

Polarization properties of planar dielectric waveguide gratings

An experimental and theoretical study of polarization properties of planar dielectric waveguide gratings operating at general (oblique) inicidence is reported. The radiation modes coupled out by a surface-relief waveguide grating, when the incident light is not normal to the grating rulings, are linearly polarized for TE excitation and are elliptically polarized for TM excitation. The polarization states of the radiation modes are determined primarily by the polarization state of the principal guided wave in the grating region and by the propagation directions of the radiation modes with respect to the plane of the principal guided wave. Experimental data and numerical results based on three physical models are presented.

Facial nerve regeneration through semipermeable chambers in the rabbit

Peripheral neural regeneration, over a 10-mm transectional gap, was determined in 70 rabbit buccal divisions of the facial nerve using two entubational systems (semipermeable and impermeable silicone chambers) prefilled with three natural occurring media (serum, blood, and saline) during a 5-week period. The number of myelinated axonal regenerates at the midchamber and at 2 mm in the distal transected neural stump were counted in each group and compared to pooled myelinated axonal counts in 9 normal rabbit buccal divisions of the facial nerve. Semipermeable porous chambers had an overall greater regeneration success rate (75% vs. 42.8%) and regained, on the average, a higher number of myelinated axons (51.4% vs. 26.1%) than silicone chamber regenerates. Semipermeable chambers prefilled with serum or blood had significantly higher regeneration success rates, myelinated axonal counts, and percentages of neural innervation of the distal transected neural stump. Both entubational systems produced similar axonal counts with intraluminal saline. The highest overall success rate (93.7%) and average number of myelinated axons per chamber (3072) were achieved in semipermeable chambers prefilled with serum. The greatest variability in myelinated axonal counts (0 to 3266 axons) and percentage of distal stump innervation (5.5% to 98.1%) was seen in silicone chambers filled with saline. The percentage of myelinated axons from the midchamber that innervated the distal stump was greater in semipermeable chambers with blood (73%) and serum (54%) than in silicone saline chambers (43%). On the average, the distal stumps from semipermeable chambers filled with serum (47%) and blood (33.5%) regained a higher percentage of normal myelinated axonal counts than silicone-saline chambers (12.5%). These results suggest that both the construction of entubational chamber and the intraluminal medium can have significant influence on neurite regeneration. Semipermeable chambers prefilled with serum have a strong neurite-promoting potential in peripheral neural regeneration of rabbit facial nerves.

Influence of Water and Temperature Stress on the Temperature Dependence of the Reappearance of Variable Fluorescence following Illumination

The temperature dependence of the rate and magnitude of the reappearance of photosystem II (PSII) variable fluorescence following illumination has been used to determine plant temperature optima. The present study was designed to determine the effect of a plant's environmental history on the thermal dependency of the reappearance of PSII variable fluorescence. In addition, this study further evaluated the usefulness of this fluorescence technique in identifying plant temperature optima. Laboratory and greenhouse grown potato (Solanum tuberosum L. cv "Norgold M") plants had a thermal kinetic window between 15 and 25 degrees C. The minimum apparent K(m) of NADH hydroxypyruvate reductase for NADH occurred at 20 degrees C. This temperature was also the temperature providing maximal reappearance of variable fluorescence. Soybean (Glycine max [L.] Merrill cv "Wayne") plants had a thermal kinetic window between 15 and 30 degrees C with a minimum apparent K(m) at 25 degrees C. Maximal reappearance of variable fluorescence was seen between 20 and 30 degrees C. To determine if increasing environmental temperatures increased the temperature optimum provided from the fluorescence response curves, potato and soybean leaves from irrigated and dryland field grown plants were evaluated. Although the absolute levels of PSII variable fluorescence declined with increasing thermal stress, the temperature optimum of the dryland plants did not increase with increased exposure to elevated temperatures. Because of variability in the daily period of high temperature stress in the field, studies were initiated with tobacco plants grown in controlled environment chambers. The reappearance of PSII variable fluorescence in tobacco (Nicotiana tabacum L. cv "Wisconsin 38") leaves that had experienced continuous leaf temperatures of 35 degrees C for 8 days had the same 20 degrees C optima as leaves from plants grown at room temperature. The results of this study suggest that the temperature optimum for the reappearance of variable fluorescence following illumination is not altered by the plant's previous exposure to variable environmental temperatures. These findings support the usefulness of this procedure for the rapid identification of a plant's temperature optimum.