bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature responses of roots: impact on growth, root system architecture and implications for phenotyping
Authors: Nagel Kerstin A. , Kastenholz Bernd , Jahnke Siegfried , van Dusschoten Dagmar , Aach Til , Mühlich Matthias , Truhn Daniel , Scharr Hanno , Terjung Stefan , Walter Achim , Schurr Ulrich
Published: November 2009

Root phenotyping is a challenging task, mainly because of the hidden nature of this organ. Only recently, imaging technologies have become available that allow us to elucidate the dynamic establishment of root structure and function in the soil. In root tips, optical analysis of the relative elemental growth rates in root expansion zones of hydroponically-grown plants revealed that it is the maximum intensity of cellular growth processes rather than the length of the root growth zone that control the acclimation to dynamic changes in temperature. Acclimation of entire root systems was studied at high throughput in agar-filled Petri dishes. In the present study, optical analysis of root system architecture showed that low temperature induced smaller branching angles between primary and lateral roots, which caused a reduction in the volume that roots access at lower temperature. Simulation of temperature gradients similar to natural soil conditions led to differential responses in basal and apical parts of the root system, and significantly affected the entire root system. These results were supported by first data on the response of root structure and carbon transport to different root zone temperatures. These data were acquired by combined magnetic resonance imaging (MRI) and positron emission tomography (PET). They indicate acclimation of root structure and geometry to temperature and preferential accumulation of carbon near the root tip at low root zone temperatures. Overall, this study demonstrated the value of combining different phenotyping technologies that analyse processes at different spatial and temporal scales. Only such an integrated approach allows us to connect differences between genotypes obtained in artificial high throughput conditions with specific characteristics relevant for field performance. Thus, novel routes may be opened up for improved plant breeding as well as for mechanistic understanding of root structure and function.
Visually evoked activity in cortical cells imaged in freely moving animals
Authors: Sawinski Juergen , Wallace Damian J. , Greenberg David S. , Grossmann Silvie , Denk Winfried , Kerr Jason N. D.
Published: November 2009

We describe a miniaturized head-mounted multiphoton microscope and its use for recording Ca
2+
transients from the somata of layer 2/3 neurons in the visual cortex of awake, freely moving rats. Images contained up to 20 neurons and were stable enough to record continuously for >5 min per trial and 20 trials per imaging session, even as the animal was running at velocities of up to 0.6 m/s. Neuronal Ca
2+
transients were readily detected, and responses to various static visual stimuli were observed during free movement on a running track. Neuronal activity was sparse and increased when the animal swept its gaze across a visual stimulus. Neurons showing preferential activation by specific stimuli were observed in freely moving animals. These results demonstrate that the multiphoton fiberscope is suitable for functional imaging in awake and freely moving animals.
The receptor protein tyrosine phosphatase LAR promotes R7 photoreceptor axon targeting by a phosphatase-independent signaling mechanism
Authors: Hofmeyer Kerstin , Treisman Jessica E.
Published: November 2009

Receptor protein tyrosine phosphatases (RPTPs) control many aspects of nervous system development. At the
Drosophila
neuromuscular junction (NMJ), regulation of synapse growth and maturation by the RPTP LAR depends on catalytic phosphatase activity and on the extracellular ligands Syndecan and Dally-like. We show here that the function of LAR in controlling R7 photoreceptor axon targeting in the visual system differs in several respects. The extracellular domain of LAR important for this process is distinct from the domains known to bind Syndecan and Dally-like, suggesting the involvement of a different ligand. R7 targeting does not require LAR phosphatase activity, but instead depends on the phosphatase activity of another RPTP, PTP69D. In addition, a mutation that prevents dimerization of the intracellular domain of LAR interferes with its ability to promote R7 targeting, although it does not disrupt phosphatase activity or neuromuscular synapse growth. We propose that LAR function in R7 is independent of its phosphatase activity, but requires structural features that allow dimerization and may promote the assembly of downstream effectors.
Rayleigh–Ritz variation method and connected-moments expansions
Authors: Amore Paolo , Fernández Francisco M
Published: November 2009

We compare the connected-moments expansion (CMX) with the Rayleigh–Ritz variational method in the Krylov space (RRK). As a benchmark model we choose the same two-dimensional anharmonic oscillator already treated earlier by means of the CMX. Our results show that the RRK converges more smoothly than the CMX. We also discuss the fact that the CMX is size consistent while the RRK is not.
The elastic constants for Fe3AlX (X=B, C and N) with anti-perovskite structure
Authors: Ouyang Yifang , Tang Mei , Fang Jie , Xiang Peng , Du Yong , He Yuehui , Liu Yong
Published: November 2009

The total energy and bulk properties of Fe3AlX (X=B, C and N) with anti-perovskite structure at T=0 K were calculated by using the projector augmented-wave (PAW) approach within generalized gradient approximation (GGA) and local density approximation (LDA). The lattice constant, bulk modulus and its pressure derivative, elastic constants, shear modulus, Poisson's ratio and Debye temperature both in paramagnetic and ferromagnetic states for Fe3AlX have been calculated. The calculations indicate that the ground states of Fe3AlB and Fe3AlC are ferromagnetic, while for Fe3AlN its ground state is paramagnetic. The calculated total energy within LDA is lower than that within GGA. The calculated lattice constant of Fe3AlC within GGA is in good agreement with experimental value, and this indicates that the calculations from GGA are more accurate than those from LDA. The calculated elastic constants and bulk moduli agree with other theoretical results available. The average magnetic moments of Fe in Fe3AlX (X=B, C and N) are 1.483, 1.103 and 0.0 μB (GGA), or 1.300, 0.401 and 0.0 μB (LDA), respectively.
NAND gate response in a mesoscopic ring: an exact result
Authors: Maiti Santanu K
Published: November 2009

NAND gate response in a mesoscopic ring threaded with a magnetic flux ϕ is investigated by using Green's function formalism. The ring is attached symmetrically to two semi-infinite one-dimensional metallic electrodes and two gate voltages, namely, V

a
and V

b
, are applied in one arm of the ring, these are treated as the two inputs of the NAND gate. We use a simple tight-binding model to describe the system and numerically compute the conductance–energy and current–voltage characteristics as functions of the gate voltages, ring-to-electrode coupling strength and magnetic flux. Our theoretical study shows that, for ϕ=ϕ0/2 (ϕ0=ch/e, the elementary flux quantum) a high output current (1) (in the logical sense) appears if one or both the inputs to the gate are low (0), while if both the inputs to the gate are high (1), a low output current (0) appears. It clearly exhibits the NAND gate behavior and this feature may be utilized in designing an electronic logic gate.
Magnetic properties study on Fe-doped calcium phosphate
Authors: Silva C C , Vasconcelos I F , Sombra A S B , Valente M A
Published: November 2009

Calcium phosphates are very important for applications in medicine due to their properties such as biocompatibility and bioactivity. In order to enhance these properties, substitution of calcium with other ions has been proposed. Partial substitution of calcium by different ions has been made in order to improve the properties of the calcium phosphates and also to allow new applications of apatite in medicine. In this work, hydroxyapatite [Ca10(PO4)6(OH)2—HAP] was prepared by high-energy dry milling (20 h) and mixed with iron oxide (5 wt.%). The mixture was calcinated at 900 °C for 5 h with a heating rate of 3 °C min−1 in an attempt to introduce iron oxide into the HAP structure. The sintered sample was characterized using x-ray diffraction (XRD) and magnetization. The 57Fe-Mössbauer spectra of the calcium phosphate oxides were also measured, revealing the presence of iron in three different phases: Ca2Fe2O5, Fe2O3 and hydroxyapatite.
Hydrogen Sulfide Increases Hypoxia-inducible Factor-1 Activity Independently of von Hippel–Lindau Tumor Suppressor-1 inC. elegans
Authors: Budde Mark W. , Roth Mark B.
Published: November 2009

Rapid alteration of gene expression in response to environmental changes is essential for normal development and behavior. The transcription factor hypoxia-inducible factor (HIF)-1 is well known to respond to alterations in oxygen availability. In nature, low oxygen environments are often found to contain high levels of hydrogen sulfide (H2S). Here, we show that Caenorhabditis elegans can have mutually exclusive responses to H2S and hypoxia, both involving HIF-1. Specifically, H2S results in HIF-1 activity throughout the hypodermis, whereas hypoxia causes HIF-1 activity in the gut as judged by a reporter for HIF-1 activity. C. elegans require hif-1 to survive in room air containing trace amounts of H2S. Exposure to H2S results in HIF-1 nuclear localization and transcription of HIF-1 targets. The effects of H2S on HIF-1 reporter activity are independent of von Hippel–Lindau tumor suppressor (VHL)-1, whereas VHL-1 is required for hypoxic regulation of HIF-1 reporter activity. Because H2S is naturally produced by animal cells, our results suggest that endogenous H2S may influence HIF-1 activity.
Novel Role of ATPase Subunit C Targeting Peptides Beyond Mitochondrial Protein Import
Authors: Vives-Bauza Cristofol , Magrané Jordi , Andreu Antoni L. , Manfredi Giovanni
Published: November 2009

In mammals, subunit c of the F1F0-ATP synthase has three isoforms (P1, P2, and P3). These isoforms differ by their cleavable mitochondrial targeting peptides, whereas the mature peptides are identical. To investigate this apparent genetic redundancy, we knocked down each of the three subunit c isoform by RNA interference in HeLa cells. Silencing any of the subunit c isoforms individually resulted in an ATP synthesis defect, indicating that these isoforms are not functionally redundant. We found that subunit c knockdown impaired the structure and function of the mitochondrial respiratory chain. In particular, P2 silencing caused defective cytochrome oxidase assembly and function. Because the expression of exogenous P1 or P2 was able to rescue the respective silencing phenotypes, but the two isoforms were unable to cross-complement, we hypothesized that their functional specificity resided in their targeting peptides. In fact, the expression of P1 and P2 targeting peptides fused to GFP variants rescued the ATP synthesis and respiratory chain defects in the silenced cells. Our results demonstrate that the subunit c isoforms are nonredundant, because they differ functionally by their targeting peptides, which, in addition to mediating mitochondrial protein import, play a yet undiscovered role in respiratory chain maintenance.
Age-dependent Preferential Dense-Core Vesicle Exocytosis in Neuroendocrine Cells Revealed by Newly Developed Monomeric Fluorescent Timer Protein
Authors: Tsuboi Takashi , Kitaguchi Tetsuya , Karasawa Satoshi , Fukuda Mitsunori , Miyawaki Atsushi
Published: November 2009

Although it is evident that only a few secretory vesicles accumulating in neuroendocrine cells are qualified to fuse with the plasma membrane and release their contents to the extracellular space, the molecular mechanisms that regulate their exocytosis are poorly understood. For example, it has been controversial whether secretory vesicles are exocytosed randomly or preferentially according to their age. Using a newly developed protein-based fluorescent timer, monomeric Kusabira Green Orange (mK-GO), which changes color with a predictable time course, here we show that small GTPase Rab27A effectors regulate age-dependent exocytosis of secretory vesicles in PC12 cells. When the vesicles were labeled with mK-GO–tagged neuropeptide Y or tissue-type plasminogen activator, punctate structures with green or red fluorescence were observed. Application of high [K+] stimulation induced exocytosis of new (green) fluorescent secretory vesicles but not of old (red) vesicles. Overexpression or depletion of rabphilin and synaptotagmin-like protein4-a (Slp4-a), which regulate exocytosis positively and negatively, respectively, disturbed the age-dependent exocytosis of the secretory vesicles in different manners. Our results suggest that coordinate functions of the two effectors of Rab27A, rabphilin and Slp4-a, are required for regulated secretory pathway.
Identification of Variants of the High Plains virus Infecting Wheat in Kansas
Authors: Seifers Dallas L. , Martin T. J. , Harvey Tom L. , Haber S. , Krokhin O. , Spicer V. , Ying S. , Standing K. G.
Published: November 2009

The properties of two virus isolates (U04-82 and U04-83) obtained from two wheat (Triticum aestivum) plants expressing mosaic symptoms were investigated using enzyme-linked immunosorbent assay (ELISA), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), time-of-flight mass spectrometry (TOFMS), and infection of wheat with resistance to Wheat streak mosaic virus (WSMV). The coat protein mass was estimated by SDS-PAGE as approximately 32 kDa for U04-82 and 30 kDa for U04-83. The amino acid sequence of the coat protein of U04-82 was 99.6 and 85.5% identical to two isolates, ABC58222 and TX96, respectively, of High Plains virus (HPV) described from Texas. U04-82 was transmitted by wheat curl mites and caused significant yield reductions in wheat resistant to WSMV. U04-83 was actually two distinct virus isolates whose capsid protein amino acid sequences were only 57 and 50% similar to that of TX96. Antiserum prepared to a synthetic peptide from the sequence of the U04-83 isolate recognized the two U04-83 isolates, but not the U04-82 isolate.
New Genotypes of Fusarium oxysporum f. sp. vasinfectum from the Southeastern United States
Authors: Holmes E. A. , Bennett R. S. , Spurgeon D. W. , Colyer P. D. , Davis R. M.
Published: November 2009

Sixty-one isolates of Fusarium oxysporum f. sp. vasinfectum were collected from cotton plants (Gossypium spp.) with symptoms of Fusarium wilt to determine the composition of races present in the southeastern United States. Analysis of partial sequences of the translation elongation factor gene revealed four novel genotypes, as well as the presence of races 3 and 8 for the first time in the United States outside of California. The majority of isolates (16 of 27) sampled from Arkansas were novel genotypes. A subset of isolates representing the novel genotypes was compared with previously described races using sequences from translation elongation factor, phosphate permase, and β-tubulin genes and their pathogenicity on a total of six Upland (Gossypium hirsutum) and Pima (G. barbadense) cotton cultivars. Two of the novel genotypes belonged to a clade containing races 1, 2, 4, 6, and 8 and two shared ancestry with race 3. All new genotypes were pathogenic to at least some of the cotton cultivars tested. The Pima cv. Phytogen 800 was relatively resistant to all genotypes of the pathogen. These results indicate that the population of F. oxysporum f. sp. vasinfectum in the southeastern United States is more diverse than previously recognized.
Evaluation of Seed and Soil Treatments with Novel Bacillus subtilis Strains for Control of Soybean Root Rot Caused by Fusarium oxysporum and F. graminearum
Authors: Zhang J. X. , Xue A. G. , Tambong J. T.
Published: November 2009

Fusarium root rot is an important disease of soybean in Ontario, Canada. This study is to select antagonistic bacterial agents as effective alternatives to chemical pesticides for the control of root rots caused by Fusarium oxysporum and F. graminearum. Twenty-two Bacillus subtilis strains from soybean and corn roots were tested in dual cultures for inhibition of mycelial growth of F. oxysporum and F. graminearum. All strains significantly reduced mycelial growth of F. oxysporum by approximately 17 to 48% and of F. graminearum by 10 to 32%. Ten B. subtilis strains selected based on their larger fungal inhibition zones were evaluated against macroconidial germination. These strains inhibited the spore germination of F. oxysporum by 20 to 48% and of F. graminearum by 14 to 32% in cell-free filtrates. Under greenhouse conditions, the efficacy of seed and soil treatments with B. subtilis strains against the two Fusarium root rot pathogens was evaluated based on root rot severity, seedling emergence, plant height, and root dry weight. Six B. subtilis strains (SB01, SB04, SB23, SB24, SB28, and SB33) from soybean roots and two strains (CB01 and CH22) from corn roots significantly reduced the severity of the two Fusarium root rots in seed or soil treatments. Strains SB01, SB04, SB23, and SB24 were the most effective treatments against both pathogens in either seed or soil treatment. When applied as seed treatments, these four strains reduced root rot severity by 43 to 63% and increased emergence by 13 to 17%, plant height by 9 to 18%, and root dry weight by 8.4 to 19%. When used as soil treatments, they reduced root rot severity by 68 to 74% and increased emergence by 14 to 18%, plant height by 11 to 23%, and root dry weight by 16 to 24%. These results suggest that the novel strains of B. subtilis identified in this research can be effective alternatives to fungicides in managing Fusarium root rots of soybean, and a greater level of efficacy may be achieved when they were used as soil treatments than seed treatments.
Leaf Whorl Inoculation Method for Screening Sugarcane Rust Resistance
Authors: Sood Sushma G. , Comstock Jack C. , Glynn Neil C.
Published: November 2009

Brown rust, caused by Puccinia melanocephala, and orange rust, caused by P. kuehnii, are agronomically important diseases of sugarcane in Florida. Cultivar resistance is the best means of controlling these diseases. Natural infection has been the primary means of assessing resistance in sugarcane cultivars against rusts; unfortunately, natural infection is not always efficient in identifying resistant cultivars due to variable environmental conditions. Therefore, a more reliable screening method is needed to effectively select resistant genotypes. An inoculation technique was evaluated for identification of brown and orange rust resistance in sugarcane cultivars. Inoculations were performed in the field by placing a 0.5-ml urediniospore suspension in the leaf whorl of three individual sugarcane stalks per plant using a pipette. Symptoms developed on leaves of all the susceptible cultivars after 4 weeks, and appeared as a band of pustules. Plants were rated for their reaction to rust 4 weeks after inoculation. The optimum concentrations of inoculum for expression of brown and orange rust symptoms were determined. The most severe brown rust and orange rust symptoms were observed using inoculum containing 105 and 104 urediniospores/ml, respectively. Clones in several stages of the Canal Point breeding program were screened for their rust reaction by leaf whorl inoculation. The technique enabled rapid screening of a large number of cultivars in field plantings using a small amount of inoculum and limited man hours.
Bacterial Spot of Tomato Caused by Xanthomonas perforans, a New Disease in Korea
Authors: Myung I.-S. , Moon S. Y. , Jeong I. H. , Lee Y.-K. , Lee Y. H. , Ra D. S.
Published: November 2009

In July 2007, a leaf spot was observed on seedlings of tomato (Solanum lycopersicum) in a commercial greenhouse in Sungju County, Korea. Symptoms were dark, circular-to-irregular, water-soaked spots surrounded by chlorotic halos. Affected leaves turned yellow and readily detached. Two bacterial isolates, BC2642 and BC2923, were obtained from leaf lesions. The isolates were gram-negative, aerobic rods with a single flagellum. On peptone sucrose agar, colonies were yellow and raised with smooth margins. Starch and pectate hydrolysis tests were positive. Pathogenicity was confirmed by spraying cell suspensions containing 108 CFU/ml on seedlings of tomato (cv. Seokwang) and hot pepper (Capsicum annuum cv. Daekwang) in a greenhouse maintained at 28 ± 2°C. The isolates induced similar symptoms as those originally observed on tomato and also caused spots and a marginal blight of leaves of pepper 2 weeks after inoculation. No symptoms were noted on the control plants sprayed with sterilized distilled water. The identity of bacteria reisolated from spots on leaves of both plants were confirmed by comparison of patterns of metabolite fingerprints with those from preliminary identification of the isolates using the Biolog Microbial Identification System, version 4.2 (Biolog Inc., Hayward, CA), and reinoculation of the seedlings as above. The 16S rRNA gene (rrs) and the intergenic spacer (IGS) located between the rrs and the 23S rRNA gene, and partial sequences of gyrB were sequenced to aid in the identification of the isolates (1–3). A 2,134-bp fragment of the rrs and IGS regions and 701-bp fragment of the gyrB region from isolates BC2642 and BC2923 were compared with sequences in GenBank. Sequences from both isolates shared 100% similarity to sequences of Xanthomonas perforans (Genbank Accession No. AF123091). On the basis of the sequences and other assays, the two isolates were identified as X. perforans. To our knowledge, this is the first report of bacterial spot of tomato caused by X. perforans in Korea. Nucleotide sequence data reported are available under Accession Nos. GQ461739 and GQ461740 for rrs and IGS of BC2642 and BC2923, respectively, and GQ368187 and GQ380567 for gyrB of BC2642 and BC2923, respectively. An outbreak of this disease in the greenhouse may be due to the use of tomato seeds harvested in foreign countries where spot is known to occur. The disease is expected to have a significant economic impact on tomato culture in Korea.

References: (1) J. B. Jones et al. Int. J. Syst. Evol. Microbiol. 50:1211, 2000. (2) N. Parkinson et al. Int. J. Syst. Evol. Microbiol. 59:264, 2009. (3) J. M. Young et al. Syst. Appl. Microbiol. 31:366, 2008.
First Report of Sclerotinia Blight Caused by Sclerotinia sclerotiorum on Petunia × hybrida in Italy
Authors: Garibaldi A. , Bertetti D. , Pensa P. , Gullino M. L.
Published: November 2009

Petunia × hybrida (Solanaceae) includes several hybrids that are grown as ornamental plants and are very much appreciated for their long-lasting flowering period. During the spring of 2009, extensive wilting was observed on 2-month-old potted plants of Petunia × hybrida cv. Sanguna Lilac Vein grown in a commercial glasshouse near Albenga (northern Italy). First symptoms included stem necrosis and darkening and withering of leaves. Wilt occurred a few days after the appearance of the first symptoms. Infected plants were characterized by the presence of soft, watery tissues. In the presence of high relative humidity, lesions became covered with a whitish mycelium and irregular, dark gray sclerotia (3.0 to 6.5 × 2.0 to 5.0 mm, average 4.8 × 3.3 mm) were produced on the mycelium. Diseased tissue was surface sterilized for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 mg/l of streptomycin sulfate. Sclerotinia sclerotiorum (Lib.) de Bary (3) was consistently recovered from infected stem pieces. Sclerotia produced on PDA measured 2.0 to 6.0 × 1.5 to 5.0 mm (average 3.9 × 3.1) mm. The internal transcribed spacer (ITS) region of rDNA was amplified with primers ITS4/ITS6 and sequenced. BLAST analysis (1) of the 548-bp segment showed a 100% homology with the sequence of S. sclerotiorum. The nucleotide sequence has been assigned GenBank Accession No. GQ375746. Pathogenicity of one isolate obtained from sclerotia of infected plants was confirmed by inoculating three 90-day-old plants belonging to cv. Sanguna Lilac Vein transplanted in 22-cm-diameter pots in a glasshouse in a sphagnum peat/pomix/pine bark/clay (50:20:20:10) mix. Inoculum that consisted of 2 g/liter of substrate of wheat kernels infested with mycelium and sclerotia was placed in the soil and around the base of each plant. Three noninoculated plants served as controls. Plants were maintained in greenhouse at temperatures ranging between 22 and 26°C and relative humidity >90%. The inoculation trial was carried out twice. All inoculated plants developed leaf yellowing by 20 days after soil infestation. White, cottony mycelium and dark sclerotia developed on stems and at the base of all inoculated plants. Eventually, infected plants wilted. Control plants remained symptomless. S. sclerotiorum was reisolated from the stems of inoculated plants. To our knowledge, this is the first report of S. sclerotiorum on Petunia × hybrida in Italy. The disease has been previously reported on Petunia × hybrida in Bermuda (2) and the United States (4).

References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997 (2) R. M. Brien. N.Z. J. Sci. Tech., A, 24, 62, 1942. (3) N. F. Buchwald. Kongl. Veterisk Landb. Aarssk. 75, 1949. (4) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989.
Safe sex: male–female coalitions and pre-copulatory mate-guarding in a fiddler crab
Authors: Milner Richard N. C. , Jennions Michael D. , Backwell Patricia R. Y.
Published: November 2009

In fiddler crabs both males and females defend territories that are essential for survival. Given pronounced sexual dimorphism in weaponry, how do weaponless females defend their territory from well-armed males? Using observational data and two simple experiments, we test whether male
Uca annulipes
protect their female neighbours from conspecific intruders. We show that males defend their female neighbours against male but not female intruders. We also show that females sometimes mate with their immediate neighbours. Male defence of female neighbours appears to represent both pre-copulatory mate-guarding and a territorial coalition. Males who ensure that their neighbour remains female could benefit through increased opportunity for future reproductive success and lower boundary maintenance costs.
Stereoselectivity in the human metabolism of methamphetamine
Authors: Li Linghui , Everhart Tom , Jacob III Peyton , Jones Reese , Mendelson John
Published: November 2009

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Methamphetamine (MA) is a chiral compound.

• The S‐(+) enantiomer is more commonly abused and is more potent in producing central nervous system and cardiovascular effects than the R‐(−) enantiomer.

• Studies describing the metabolism of MA have mainly been done with the S‐(+)‐isomer; pharmacokinetic data for R‐(−)‐MA or racemic MA are very limited.

WHAT THIS STUDY ADDS

• Stereoselectivity exists in the metabolism of MA.

• Urinary excretion of para hydroxymethamphetamine (pOH‐MA) was found to be least affected by stereoselectivity.

• It is suggested that pOH‐MA may be a more stable biomarker of MA abuse.

AIM

To characterize the formation and urinary elimination of metabolites of S‐(+) and R‐(−) methamphetamine (MA) in humans.

METHODS

In this 12‐subject, six‐session, double‐blind, placebo‐controlled, balanced, crossover design study, the formation of the MA metabolites para hydroxymethamphetamine (pOH‐MA) and amphetamine (AMP) were determined in urine after intravenous doses of S‐(+)‐MA 0.25 and 0.5 mg kg−1, R‐(−)‐MA 0.25 and 0.5 mg kg−1, racemic MA 0.5 mg kg−1, or placebo. Parent drug and metabolite levels in urine and plasma were measured by gas chromatography‐mass spectrometry. Pharmacokinetic parameters were calculated by noncompartmental models using WinNonlin.

RESULTS

An approximately threefold enantioselectivity difference in elimination was observed for AMP, with 7% of the dose converted to S‐(+)‐AMPvs.2% to R‐(−)‐AMP (P< 0.001). Furthermore, less R‐(−)‐pOH‐MA was excreted in the urine compared with S‐(+)‐pOH‐MA (8%vs.11%,P= 0.02). Correspondingly, S‐(+)‐MA excretion was less than R‐(−)‐MA (42%vs.52%;P= 0.005).

CONCLUSIONS

The metabolism of MA is enantioselective, with formation of AMP having the highest isomer selectivity. A greater percentage of MA is converted to pOH‐MA (8–11%) than AMP (2–7%). The formation of pOH‐MA was less affected by the MA enantiomer administered, suggesting that urine pOH‐MA may be a more stable biomarker of MA metabolism.
Randomized cross‐over clinical trial of injectablevs.implantable depot testosterone for maintenance of testosterone replacement therapy in androgen deficient men
Authors: Fennell Carolyn , Sartorius Gideon , Ly Lam P. , Turner Leo , Liu Peter Y. , Conway Ann J. , Handelsman David J.
Published: November 2009

Background Life‐long testosterone replacement therapy (TRT) for younger men with organic androgen deficiency is best provided by depot testosterone (T) products. This study compared directly the two long‐acting depot T products, subdermal T implants (TI) and injectable T undecanoate (TU) for maintenance of TRT.

Design, setting and participants Men with organic androgen deficiency (n = 38) undergoing regular TRT at an academic Andrology centre were recruited for a two period, randomized sequence, cross‐over clinical trial without intervening wash‐out period of TRT maintenance.

Outcomes For both depot T products, their pharmacokinetics and pharmacodynamics were evaluated using a range of androgen sensitive clinical, laboratory and quality of life measures as well as preference for ongoing treatment after experience of both products.

Results The two depot T products had distinct pharmacokinetics and were not bioequivalent. However, there were no consistent clinical differences in a comprehensive range of pharmacodynamic measures reflecting androgen effects on biochemistry and haematology, muscle mass and strength, and quality of life, mood and sexual function. The majority (91%) of participants chose TU over TI at study completion.

Conclusion Despite significant pharmacokinetic differences, the two depot T products are clinically interchangeable allowing for choice dependent on patient and physician delivery preference in practice but most patients preferred the injectable over the implantable form.
Identification of lateral discontinuities via multi‐offset phase analysis of surface wave data
Authors: Vignoli Giulio , Cassiani Giorgio
Published: November 2009

Surface wave methods are based on the inversion of observed Rayleigh wave phase‐velocity dispersion curves. The goal is to estimate mainly the shear‐wave velocity profile of the investigated site. The model used for the interpretation is 1D, hence results obtained wherever lateral variations are present cannot be considered reliable.

In this paper, we study four synthetic models, all with a lateral heterogeneity. When we process the entire corresponding seismograms with traditional f‐k approach, the resulting 1D profiles are representative of the subsurface properties averaged over the whole length of the receivers lines. These results show that classical analysis disregards evidences of sharp lateral velocity changes even when they show up in the raw seismograms.

In our research, we implement and test over the same synthetic models, a novel robust automated method to check the appropriateness of 1D model assumption and locate the discontinuities. This new approach is a development of the recent multi‐offset phase analysis with the following further advantages: it does not need previous noise evaluation and more than one shot.

Only once the discontinuities are clearly identified, we confidently perform classical f‐k dispersion curve extraction and inversion separately on both sides of the discontinuity. Thus the final results, obtained by putting side by side the 1D profiles, are correct 2D reconstructions of the discontinuous S‐wave distributions obtained without any additional ad‐hoc hypotheses.
Parabiotic associations between tropical ants: equal partnership or parasitic exploitation?
Authors: Menzel F. , Blüthgen N.
Published: November 2009

1. The huge diversity of symbiotic associations among animals and/or plants comprises both mutualisms and parasitisms. Most symbioses between social insect species, however, involve social parasites, while mutual benefits have been only suspected for some parabiotic associations – two colonies that share a nest.

2. In the rainforest of Borneo, we studied parabiotic associations between the ants Crematogaster modiglianii and Camponotus rufifemur. Parabiotic nests were regularly found inside hollow tree trunks, most likely initiated by Cr. modiglianii. This species frequently nested without its partner, whereas we never found non‐parabiotic Ca. rufifemur nests. We experimentally investigated potential benefits, potential interference competition for food (as a probable cost), and foraging niches of both species.

3. The two species never showed aggressive interactions and amicably shared food resources. However, Cr. modiglianii had a wider temporal and spatial foraging range than Ca. rufifemur, always found baits before Ca. rufifemur and recruited more efficiently. Camponotus rufifemur probably benefited from following pheromone trails of Cr. modiglianii. In turn, Ca. rufifemur was significantly more successful in defending the nest against alien ants. Crematogaster modiglianii hence may profit from its partner’s defensive abilities.

4. In neotropical parabioses, epiphytes grown in ‘ant‐gardens’ play a crucial role in the association, e.g. by stabilization of nests. Hemiepiphytic Poikilospermum cordifolium (Cecropiaceae) seedlings and saplings frequently grew in the entrances of parabiotic nests in Borneo, obviously dispersed by the ants. In cafeteria experiments, both parabiotic ants carried its elaiosome‐bearing seeds into the nest. However, P. cordifolium does not provide additional nest space, contrasting with neotropical ant‐gardens.

5. The parabiotic association appears beneficial for both ant species, the main benefits being nest initiation by Cr. modiglianii and interspecific trail‐following (for Ca. rufifemur), and, in turn, nest defence by Ca. rufifemur (for Cr. modiglianii). However, Ca. rufifemur seems to be more dependent on its partner than vice versa.
Endoscopic transpapillary drainage for external fistulas developing after surgical or radiological pancreatic interventions
Authors: Rana Surinder Singh , Kumar Bhasin Deepak , Nanda Mohit , Siyad Ismail , Gupta Rajesh , Kang Mandeep , Nagi Birinder , Singh Kartar
Published: November 2009

Background and Aims:  External pancreatic fistulas (EPFs) are a therapeutic challenge. The present study was conducted to evaluate the efficacy of endoscopic transpapillary nasopancreatic drainage (NPD) in patients with EPF.

Methods:  Over 12 years, 23 patients (19 males) with EPF underwent attempted endoscopic transpapillary NPD. The end points were fistula closure with healing of pancreatic duct disruption on nasopancreatogram, or need for surgery.

Results:  All 23 patients had persistent drain output (>50 mL/day) for >6 weeks. The mean output volume of the fistula was 223 mL (range: 60 mL to 750 mL). Sixteen patients had partial and seven patients had complete pancreatic duct disruption. The NPD could be successfully placed in 21/23 (91.3%) patients. Disruption was bridged in 15 of 16 patients with partial duct disruption. EPF healed in 2–8 weeks of placement of NPD in all of the patients with partial duct disruption that was bridged and there was no recurrence at a mean follow‐up of 38 months. The EPF resolved in only 2/6 (33%) patients with complete duct disruption.

Conclusions:  External pancreatic fistulas developing following percutaneous drainage of pancreatic fluid collections or surgical necrosectomy can be effectively treated by transpapillary nasopancreatic drain placement especially when there is partial ductal disruption and the disruption can be bridged.
Multiple tiny granulomatous lesions with eosinophils in a patient with smoldering‐type adult T‐cell leukaemia: The possibility of a new type of bronchioloalveolopathy
Authors: ISHII Hiroshi , KAWABATA Yoshinori , AMEMIYA Yuka , OGATA Masao , KADOTA Jun‐ichi
Published: November 2009

We herein describe the first case, to our knowledge, of pulmonary lesions characterized by necrotizing granuloma formation with eosinophils, in a patient with smoldering‐type adult T‐cell leukaemia. A 74‐year‐old man, diagnosed with smoldering‐type adult T‐cell leukaemia 1 year previously, was admitted due to repeated pyrexia and concurrent identification of diffuse small pulmonary nodules. A surgical lung biopsy specimen revealed inflammatory nodular lesions measuring up to 3 mm in size, which contained necrotizing and non‐necrotizing granulomas, intraluminar organization and eosinophils, and were of unknown aetiology. The patient's condition, including the radiological findings, improved gradually without any treatment. This case suggests the possibility of a new type of human T‐lymphotropic virus type‐1 associated bronchioloalveolar disorder.
The physical activity, stress and metabolic syndrome triangle: a guide to unfamiliar territory for the obesity researcher
Authors: Holmes M. E. , Ekkekakis P. , Eisenmann J. C.
Published: November 2009

Research aimed at deciphering the aetiology of obesity and the metabolic syndrome remains focused on two behavioural factors, namely diet and physical activity, even though epidemiologic research suggests that these two cornerstones of treatment and prevention account for only a small‐to‐moderate portion of the variance in these phenotypes. In recent years, this observation has prompted the intensified investigation of the pathogenic potential of factors that extend beyond the traditional concept of energy imbalance and examine the putative causes of this imbalance. Psychosocial stress has emerged as one such factor, raising the need for researchers to be informed about this expansive and complex literature. The purpose of this review is twofold (i) To introduce obesity researchers to fundamental concepts and historically important theoretical developments in the stress field and (ii) To outline the dyadic and triadic interactions between stress, physical activity and the metabolic syndrome. Although the expansion of the research focus to multiple, diverse and interacting putative causal agents will certainly increase the complexity of the research enterprise, this step seems essential for the comprehension and effective response to the continuing rise in the prevalence of obesity and the metabolic syndrome.
Study: The Lack of Significant Association of the Catechol‐O‐Methyl Transferase (COMT) Gene Polymorphism in Violent Offenders with Mental Retardation
Authors: Isir Aysun Baransel , Dai Alper Ibrahim , Nacak Muradiye , Gorucu Senay
Published: November 2009

Abstract: Little is known about criminality of cognitively impaired people and also there have been no reports on the relationship between catechol‐O‐methyl transferase (COMT) and committed Mental Retardation (MR) subjects. In the present study, the association between committed (violent offences) MR subjects and genetic variants of COMT were investigated by using polymerase chain reaction and based restriction fragment length polymorphism methods. During 6 years of follow‐up, 36 violent offenders with mild MR were investigated. Thirty‐six control volunteers were included in the study as a control group. H/L polymorphism of the COMT gene was investigated in these two groups. In conclusion, the COMT gene genotype distribution and allele frequency is not significantly different between the two groups (p > 0.05). This result suggests that the H/L polymorphism of the COMT gene does not show an association with the potential of “commits‐violent offense” of Turkish subjects with mental retardation, compared with control group.
Correlation of the Experience of Peer Relational Aggression Victimization and Depression among African American Adolescent Females*
Authors: Gomes Melissa M. , Davis Bertha L. , Baker Spencer R. , Servonsky E. Jane
Published: November 2009

PROBLEM:  This study aimed to examine if the experience of peer relational aggression victimization (PRAV) can be linked to feelings of depression in the African American adolescent female population.

METHODS:  The sample included 241 college‐age African American adolescent females assessed for PRAV and depression. Statistical analysis was carried out to determine the relationship between the variables.

FINDINGS:  PRAV in this study population does exist as a detrimental phenomenon, whereby PRAV significantly correlates with depression, r (214) = 0.29, p < .01.

CONCLUSION:  Nurses can assist the adolescent clients experiencing relational aggression by becoming knowledgeable on the presentation and manifestations of this experience.
Bacterial colonisation of root canal dentine previously treated with endodontic irrigants
Authors: Rasimick Brian J. , Shah Rinal P. , Musikant Barry L. , Deutsch Allan S.
Published: November 2009

Certain irrigants leave antimicrobial residues on dentine. This study assessed if residues from MTAD, Endo‐CHX, Peridex Oral Rinse or 6% NaOCl were inactivated by exposure to simulated leakage. Extracted teeth (15/group) were cut and drilled to produce a cylindrical canal space. They were irrigated, dried with paper points and transferred into 1 mL of simulated leakage (Enterococcus faecalis in tryptic soy broth) every 24 h. After one, two or three transfers, the number of colony forming units was measured by drilling the canal space and recovering the dentine shavings in antimicrobial‐inactivating broth. Two‐way anova of the log‐transformed data showed irrigation method, leakage volume and their interaction were significant factors (P < 0.001). Compared with the positive control, the logarithmic reductions in the number of E. faecalis colonies after the first and third millilitre of leakage were: Endo‐CHX 6.2 and 2.4; MTAD 3.4 and 2.7; Peridex 1.6 and 0.4; NaOCl 1.0 and 0.0.
Selective dry etching of attenuated phase-shift mask materials for extreme ultraviolet lithography using inductively coupled plasmas
Authors: Jung H. Y. , Park Y. R. , Lee H. J. , Lee N.-E. , Jeong C. Y. , Ahn Jinho
Published: November 2009

Among the core extreme ultraviolet lithography (EUVL) technologies, mask fabrication is of considerable importance due to the use of new reflective optics having a completely different configuration from that of conventional photolithography. This study investigated the etching properties of attenuated phase-shift mask materials for EUVL, such as TaN (attenuator layer), Al2O3 (spacer), Mo (phase shifting layer), Ru (buffer/capping/etch-stop layer), and Mo–Si multilayer (reflective layer) by varying the Cl2∕Ar gas flow ratio, dc self-bias voltage (Vdc), and etch time in inductively coupled plasmas. For the fabrication of the attenuated EUVL mask structure proposed herein, the TaN, Al2O3, and Mo layers need to be etched with no loss of the Ru layer on the Mo–Si multilayer. The TaN and Al2O3 layers were able to be etched in BCl3∕Cl2∕Ar plasmas with a Vdc of −100V and the Mo layer was etched with an infinitely high etch selectivity over the Ru etch-stop layer in a Cl2∕Ar plasma with a Vdc of −25V even with increasing overetch time.
Electrical characteristics of thin boron carbonitride films on Ge(100) and Si(100)
Authors: Fitzpatrick P. R. , Ekerdt J. G.
Published: November 2009

Metal insulator semiconductor structures were fabricated from n-Si(100) and n-Ge(100) wafers passivated with thin (4.5–5 nm) films of N-rich BCxNy (0.09≤x≤0.15, 0.38≤y≤0.52) and with atomic layer deposition HfO2 (10 nm) as the gate dielectric. C-V and I-V characteristics of devices with BCxNy films grown at 275–400 °C by chemical vapor deposition showed that lower deposition temperatures resulted in improved electrical characteristics, including decreased hysteresis, lower VFB shift, lower leakage current, and less C-V stretch out. The electrical improvement is attributed to decreased bulk and interfacial defects in lower temperature deposited BCxNy films, which also had a higher optical bandgap [Eg=3.55 eV at 275 °C on Ge(100)], lower subbandgap absorption, lower index of refraction [n(633 nm)=1.84 at 275 °C on Ge(100)], reduced O uptake during ambient exposure, and increased percentage of B. Even for the lowest growth temperature studied (275 °C), BCxNy-passivated Ge(100) devices had considerable hysteresis (1.05 V), and electrical characteristics worsened after a postmetallization anneal. BCxNy-passivated Si(100) devices outperformed similar Ge(100) devices likely due to the higher interface state densities at the BCxNy–Ge(100) interface associated with the higher relative inertness of Ge(100) to thermal nitridation. C-rich BC0.61N0.08 films were also investigated but large amounts of hysteresis and fixed negative charge motivated the abandonment of these films.
Evaluation of Pneumococcal Polysaccharide Immunoassays Using a 22F Adsorption Step with Serum Samples from Infants Vaccinated with Conjugate Vaccines
Authors: Poolman Jan T. , Frasch Carl E. , Käyhty Helena , Lestrate Pascal , Madhi Shabir A. , Henckaerts Isabelle
Published: November 2009

The history of the pneumococcal polysaccharide enzyme-linked immunosorbent assay (ELISA) is characterized by a continuous search for increased specificity. A third-generation ELISA that uses 22F polysaccharide inhibition has increased the specificity of the assay, particularly at low antibody concentrations. The present work compared various 22F ELISAs and non-22F ELISAs. The comparisons involved three different laboratories, including a WHO reference laboratory, and included sera from subjects from different geographic areas immunized with different pneumococcal conjugate vaccines, including the licensed 7-valent Prevenar vaccine and the 10-valent Synflorix vaccine. All comparisons led to the same conclusion that the threshold defined as 0.35 μg/ml for the WHO non-22F ELISA is lower when any 22F ELISA is used. The use of highly purified polysaccharides for coating further improved the specificity of the assay. In conclusion, we confirm that the 22F ELISA can be recommended as a reference method for the determination of antibodies against pneumococcal polysaccharides.