bluuebunny/crossref_metadata_2025 huggingface dataset:
Dissimilatory Arsenate and Sulfate Reduction in Sediments of Two Hypersaline, Arsenic-Rich Soda Lakes: Mono and Searles Lakes, California
Authors: Kulp T. R. , Hoeft S. E. , Miller L. G. , Saltikov C. , Murphy J. N. , Han S. , Lanoil B. , Oremland R. S.
Published: October 2006

A radioisotope method was devised to study bacterial respiratory reduction of arsenate in sediments. The following two arsenic-rich soda lakes in California were chosen for comparison on the basis of their different salinities: Mono Lake (∼90 g/liter) and Searles Lake (∼340 g/liter). Profiles of arsenate reduction and sulfate reduction were constructed for both lakes. Reduction of [
73
As]arsenate occurred at all depth intervals in the cores from Mono Lake (rate constant [
k
] = 0.103 to 0.04 h
−1
) and Searles Lake (
k
= 0.012 to 0.002 h
−1
), and the highest activities occurred in the top sections of each core. In contrast, [
35
S]sulfate reduction was measurable in Mono Lake (
k
= 7.6 ×10
4
to 3.2 × 10
−6
h
−1
) but not in Searles Lake. Sediment DNA was extracted, PCR amplified, and separated by denaturing gradient gel electrophoresis (DGGE) to obtain phylogenetic markers (i.e., 16S rRNA genes) and a partial functional gene for dissimilatory arsenate reduction (
arrA
). The amplified
arrA
gene product showed a similar trend in both lakes; the signal was strongest in surface sediments and decreased to undetectable levels deeper in the sediments. More
arrA
gene signal was observed in Mono Lake and was detectable at a greater depth, despite the higher arsenate reduction activity observed in Searles Lake. A partial sequence (about 900 bp) was obtained for a clone (SLAS-3) that matched the dominant DGGE band found in deeper parts of the Searles Lake sample (below 3 cm), and this clone was found to be closely related to SLAS-1, a novel extremophilic arsenate respirer previously cultivated from Searles Lake.
Metschnikowia
Strains Isolated from Botrytized Grapes Antagonize Fungal and Bacterial Growth by Iron Depletion
Authors: Sipiczki Matthias
Published: October 2006

Noble-rotted grapes are colonized by complex microbial populations. I isolated pigment-producing
Metschnikowia
strains from noble-rotted grapes that had antagonistic activity against filamentous fungi, yeasts, and bacteria. A red-maroon pigment was formed from a diffusible colorless precursor released by the cells into the medium. The conversion of the precursor required iron and could occur both in the cells (red colonies) and in the medium (red halos around colonies). The intensity of pigmentation was correlated with the intensity of the antimicrobial activity. Mutants that did not form pigment also lacked antifungal activity. Within the pigmented halos, conidia of the sensitive fungi did not germinate, and their hyphae did not grow and frequently lysed at the tips. Supplementation of the medium with iron reduced the size of the halos and the inhibition zones, while it increased the pigment accumulation by the colonies. The iron-binding agent tropolone had a similar effect, so I hypothesize that pigmented
Metschnikowia
isolates inhibit the growth of the sensitive microorganisms by pigment formation, which depletes the free iron in the medium. As the pigment is a large nondiffusible complex produced in the presence of both low and high concentrations of ferric ions, the proposed mechanism is different from the mechanisms operating in microbes that release siderophores into the environment for iron acquisition.
Changes in Periodontal Health Status Are Associated with Bacterial Community Shifts as Assessed by Quantitative 16S Cloning and Sequencing
Authors: Kumar Purnima S. , Leys Eugene J. , Bryk Jennifer M. , Martinez Francisco J. , Moeschberger Melvin L. , Griffen Ann L.
Published: October 2006

The gingival sulcus contains a complex ecosystem that includes many uncultivated bacteria. Understanding the dynamics of this ecosystem in transitions between health and disease is important in advancing our understanding of the bacterial etiology of periodontitis. The objective of this longitudinal study was to examine the stability of bacterial colonization in the gingival crevice and to explore the relationship between shifts in microbial composition and changes in periodontal health status using a comprehensive, quantitative, culture-independent approach. Subgingival plaque samples and periodontal data were collected from 24 subjects over 2 years. Baseline and 2-year plaque samples were analyzed using quantitative ribosomal 16S cloning and sequencing. Ten subjects remained periodontally healthy over 2 years, the periodontal health of seven subjects worsened, and seven subjects showed clinical improvement. Bacterial stability was greatest among healthy, clinically stable subjects and lowest for subjects whose periodontal status worsened (
P
= 0.01). Higher numbers of species lost or gained were also observed for subjects whose clinical status changed (
P
= 0.009). This provides evidence that a change in periodontal status is accompanied by shifts within the bacterial community. Based on these data, measures of microbial stability may be useful in clinical diagnosis and prognosis. Regarding individual species, increases in levels of the uncultivated phylotype
Veillonella
sp. oral clone X042, a gram-negative bacterium and the most common member of the subgingival bacterial community, were associated with periodontal health (
P
= 0.04), suggesting that this is an important beneficial species.
Filifactor alocis
, a gram-positive anaerobe, was found at higher levels in subjects with disease (
P
= 0.01).
Performance of the Genotype MTBDR Line Probe Assay for Detection of Resistance to Rifampin and Isoniazid in Strains of
Mycobacterium tuberculosis
with Low- and High-Level Resistance
Authors: Brossier Florence , Veziris Nicolas , Truffot-Pernot Chantal , Jarlier Vincent , Sougakoff Wladimir
Published: October 2006

We assessed the performance of the Genotype MTBDR line probe assay that offers the simultaneous identification of
Mycobacterium tuberculosis
and its resistance to rifampin (RIF) and isoniazid (INH) by detecting the most commonly found mutations in the
rpoB
and
katG
genes. One hundred thirteen
M. tuberculosis
isolates were tested. The nucleotide sequences of the
katG
and
inhA
genes and the
mabA
-
inhA
promoter region were also determined. The MTBDR assay detected 100% and 67% (
n
= 64) of the strains resistant to RIF and INH, respectively. Among the latter, 62 strains carried a Ser315Thr mutation in
katG
, 59 of them displaying a high level of resistance to INH. Two strains with a low level of INH resistance had a Ser315Asn mutation. No mutation was found by the MTBDR assay for 31 INH-resistant strains (33%), of which 24 showed a low level of resistance. By DNA sequencing, we found among them various mutations in the KatG protein for 7 strains, a C→T mutation in position −15 of the
mabA
-
inhA
promoter in 17 strains, and a Ser94Ala mutation in InhA for 7 strains. In conclusion, the MTBDR assay, which fits easily in the workflow of a routine laboratory, enabled the detection of 100% of the RIF-resistant strains and 89% of the INH-resistant strains with a high level of resistance but only 17% of the strains characterized by a low level of INH resistance, indicating that the test can be used as a rapid method to detect in the same experiment the rifampin-resistant and the high-level isoniazid-resistant strains of
M. tuberculosis.
Molecular Basis of Resistance Displayed by Highly Ciprofloxacin-Resistant
Salmonella enterica
Serovar Typhi in Bangladesh
Authors: Saha Samir K. , Darmstadt Gary L. , Baqui Abdullah H. , Crook Derrick W. , Islam M. Nurul , Islam Maksuda , Hossain Maqsud , El Arifeen Shams , Santosham Mathuram , Black Robert E.
Published: October 2006

Highly ciprofloxacin-resistant (MIC, 512 μg/ml) strains of
Salmonella enterica
serovar Typhi were isolated from the blood of typhoid patients in Dhaka, Bangladesh. The strains were indistinguishable by their antibiograms, biotypes, and variable-number tandem repeat types and had matching point mutations at positions 83 and 87 of the
gyrA
gene. The isolation of these strains in an area of high endemicity indicates the need for continuous surveillance of antibiotic resistance of
S. enterica
serovar Typhi and for the rationalized use of ciprofloxacin.
Malaria: Mechanisms of Erythrocytic Infection and Pathological Correlates of Severe Disease
Authors: Haldar Kasturi , Murphy Sean C. , Milner Dan A. , Taylor Terrie E.
Published: October 2006

Malaria is an ancient disease that continues to cause enormous human morbidity and mortality. The life cycle of the causative parasite involves multiple tissues in two distinct host organisms, mosquitoes and humans. However, all the clinical symptoms of malaria are a consequence of infection of human erythrocytes. An understanding of the basic mechanisms that govern parasite invasion, remodeling, growth, and reinvasion of erythrocytes and the complex events leading to tissue pathology may yield new diagnostics and treatments for malaria. This approach is revealing a more complete picture of the most serious syndrome associated with this infection—cerebral malaria. We focus on the most recent understanding of the molecular basis of infection, summarize our finding from an ongoing pediatric cerebral malaria autopsy study in Malawi, and integrate these insights to malarial pathology.
Perceptual Correlate of Nociceptive Long-Term Potentiation (LTP) in Humans Shares the Time Course of Early-LTP
Authors: Klein Thomas , Magerl Walter , Treede Rolf-Detlef
Published: October 2006

As in neocortex and hippocampus, neurons in the dorsal horn of the spinal cord develop long-term potentiation of synaptic efficacy (LTP) on high-frequency stimulation (HFS) of their afferent input, although how long LTP lasts in this nociceptive relay nucleus has not yet been addressed. Here we studied neurogenic hyperalgesia, a perceptual correlate of nociceptive LTP, in 13 healthy subjects, after HFS (5 × 1 s at 100 Hz) of superficial cutaneous afferents. HFS led to a mean upward shift of the stimulus–response function for pinprick-evoked pain (punctate mechanical hyperalgesia) in all subjects by a factor of 2.5 ( P < 0.001) that lasted undiminished for the initial 1-h observation period. Follow-up tests until the next day revealed that this type of neurogenic hyperalgesia decayed with a t1/2 of 3.3 h (99% CI: 3.1–3.5 h) and disappeared completely within 25.4 h (99% CI: 20.4–31.6 h). Touch-evoked pain (dynamic mechanical allodynia) developed in eight of 13 subjects, decayed with a t1/2 of 2.9 h from the maximum and disappeared within 9.3 h. These findings suggest that a single HFS session induces nociceptive LTP in healthy subjects that corresponds to early-LTP (LTP1), implying primarily posttranslational mechanisms for this type of plasticity of human pain perception.
RNASEL Gene Polymorphisms and the Risk of Prostate Cancer: a Meta-analysis
Authors: Li Huihua , Tai Bee Choo
Published: October 2006

Purpose: Studies revealing conflicting results on the role of RNASEL polymorphisms Glu265X, Arg462Gln, and Asp541Glu on prostate cancer risk led us to perform a meta-analysis to investigate the association of these polymorphisms and prostate cancer risk.

Experimental Design: Relevant studies were selected by searching PubMed from January 1996 to August 2005 using keywords “RNASEL gene AND prostate cancer.” For each study, odds ratio (OR) with 95% confidence interval (95% CI) was calculated to estimate the gene effect. Pooled estimates of the OR were computed using the random effects model.

Results: Ten studies were included in the meta-analysis. The overall results suggested no major influence of these variants on prostate cancer risk. However, analysis of the Asp541Glu polymorphism by ethnic populations showed that Asp/Glu (familial cases versus control: OR, 1.38; 95% CI, 1.04-1.82; sporadic cases versus control: OR, 1.26; 95% CI, 1.07-1.48; prostate cancer versus control: OR, 1.29; 95% CI, 1.12-1.48) and Asp/Glu + Glu/Glu (familial cases versus control: OR, 1.37; 95% CI, 1.10-1.70; sporadic cases versus control: OR, 1.24; 95% CI, 1.07-1.44; prostate cancer versus control: OR, 1.27; 95% CI, 1.13-1.44) increased prostate cancer risk in Caucasians, thus suggesting a dominant model for the Glu variant.

Conclusions: Compared with the genotype Asp/Asp, the Glu variant at the Asp541Glu polymorphism increases prostate cancer risk by <2-fold in Caucasians, regardless of family history of the disease. This suggests that genuine genetic effects of this polymorphism may account for only a part of prostate cancer in the Caucasian population.
Enhanced Antitumor Effect of Oncolytic Adenovirus Expressing Interleukin-12 and B7-1 in an Immunocompetent Murine Model
Authors: Lee Young-Sook , Kim Joo-Hang , Choi Kyung-Ju , Choi Il-Kyu , Kim Hoguen , Cho Sungae , Cho Byoung Chul , Yun Chae-Ok
Published: October 2006

Purpose: We investigated whether an armed viral platform, where lytic property of a viral infection is coupled to viral-mediated delivery of therapeutic genes, could increase the therapeutic potential of a viral-based therapy.

Experimental Design: We generated interleukin (IL)-12-expressing oncolytic adenovirus (YKL-IL-12) and IL-12- and B7-1-expressing (YKL-IL12/B7) oncolytic adenovirus. Therapeutic efficacy of these newly engineered adenoviruses was then evaluated in vivo using an immunocompetent mouse bearing murine melanoma B16-F10 tumors. Overall survival was assessed with the Kaplan-Meier method. The induction of immune cell cytotoxicity was assessed by CTL assay, IFN-γ enzyme-linked immunospot assay, and immunohistochemical studies.

Results: YKL-IL12/B7 oncolytic adenovirus, expressing both IL-12 and B7-1, showed a higher incidence of complete tumor regression compared with the analogous oncolytic adenovirus, YKL-1, or IL-12-expressing, YKL-IL12. Significant survival advantage was also seen in response to YKL-IL12/B7. Moreover, IL-12 and IFN-γ levels produced in tumors treated with YKL-IL12/B7 was significantly greater than those treated with YKL-IL12. The enhanced survival advantage was mediated by the induction of immune cell cytotoxicity. In agreement with these results, massive infiltration of CD4+ and CD8+ T cells into tissues surrounding the necrotic area of the tumor was observed following in situ delivery of YKL-IL12/B7.

Conclusion: Combination of oncolysis and the enhancement of antitumor immune response by oncolytic adenovirus expressing both IL-12 and B7-1 elicits potent antitumor effect and survival advantage.
An Extended Procedure for Implementing the Relative Operating Characteristic Graphical Method
Authors: Semazzi Fredrick H. M. , Mera Roberto J.
Published: October 2006

The functional relationship between the relative operating characteristic (ROC) and the economic value (EV) graphical methods have been exploited to develop a hybrid procedure called the extended ROC (EROC) method. The EROC retains the appealing simplicity of the traditional ROC method and the ability of the EV method to provide evaluation of the performance of an ensemble climate prediction system (EPS) for a hypothetical end user defined by the cost–loss ratio (μ = C/L). An inequality defining the lower and upper theoretical bounds of μ has been derived. Outside these limits, the EPS yields no added benefits for end user μ relative to the use of climatological persistence as an alternative prediction system. In the traditional ROC graphical method, the ROC skill (ROCS) is often expressed in terms of the area between the ROC graph and the diagonal baseline passing through the origin with slope m = 1. Thus, ROCS = 2A − 1, where A is the area under the ROC graph. In the proposed EROC approach, a more general procedure is recommended based on the construction of user-specific baselines that do not necessarily pass through the origin and, in general, have slope m ≠ 1. The skill of a particular EPS computed from the EROC method is proportional to the corresponding estimated value based on the EV graphical method. Therefore, the EROC geometry conveys the same basic information as the EV method. The Semazzi–Mera skill score (SMSS) is proposed as a convenient and compact way of expressing the combined verification based on the ROC and EV methods. The ROCS estimate is a special case of the SMSS. The near-horizontal trail-like geometry sometimes exhibited by EV graphs is also examined. It is shown to occur when either the hit-rate or false-alarm term dominates in the formula for EV, unlike the more typical situation in which both terms are comparable in magnitude.
Human plasmacytoid dendritic cells regulate immune responses to Epstein-Barr virus (EBV) infection and delay EBV-related mortality in humanized NOD-SCID mice
Authors: Lim Wai Hon , Kireta Svjetlana , Russ Graeme Randolph , Coates Patrick Toby Hewlett
Published: October 2006

Epstein-Barr virus (EBV) is associated with posttransplant lymphoproliferative disease (PTLD), which is a leading cause of cancer death in recipients of transplants. We investigated the role of plasmacytoid dendritic cells (PDCs) in the development of EBV infection and the onset of lymphoproliferative disease (LPD) in humanized NOD-SCID mice and studied the effect of EBV on PDC function. NOD-SCID mice reconstituted with PDC-depleted peripheral blood mononuclear cells (PBMCs) from EBV IgG+ human donors had significantly enhanced mortality from disseminated EBV infection (median survival, 43 days) compared to PBMC-only mice (median survival, 72 days; log-rank P < .05). Mice reconstituted with PDC-enriched PBMCs challenged with EBV exhibited delayed mortality from EBV-LPD (median survival, 80 days) compared to PBMC-only mice challenged with EBV (median survival, 50 days; log-rank P < .05). EBV-stimulated pDCs produced interferon α (IFN-α) and promoted the activation of natural killer cells and IFN-γ–producing CD3+T cells. PDC activation of CD3+T cells in response to EBV stimulation was dependent on cell-to-cell contact, in part mediated by toll-like receptor 9 (TLR-9) signaling that was inhibited by chloroquine and TLR-9 inhibitory CpG. Thus, PDCs play an important role in anti-EBV cellular immune responses that may be targets for manipulation in novel strategies for the treatment of PTLD.
Dual role for RhoA in suppression and induction of cytokines in the human neutrophil
Authors: Fessler Michael B. , Arndt Patrick G. , Just Ingo , Nick Jerry A. , Malcolm Kenneth C. , Scott Worthen G.
Published: October 2006

Production of tumor necrosis factor-α (TNFα) by the neutrophil (PMN) is a pivotal event in innate immunity, but the signals regulating TNFα induction in this primary cell are poorly understood. Herein, we use protein transduction to identify novel, opposing anti– and pro–cytokine-inducing roles for RhoA in the resting and lipopolysaccharide (LPS)–stimulated human PMN, respectively. In the resting cell, RhoA suppresses Cdc42 activation, IκBα degradation, nuclear factor-κB (NF-κB) activation, and induction of TNFα and NF-κB–dependent chemokines. Suppression of TNFα induction by RhoA is Rho kinase α (ROCKα) independent, but Cdc42 dependent, because TNFα induction by C3 transferase is attenuated by inhibition of Cdc42, and constitutively active Cdc42 suffices to activate NF-κB and induce TNFα. By contrast, we also place RhoA downstream of p38 mitogen-activated protein kinase and Cdc42 in a novel LPS-activated pathway in which p38, Cdc42, and ROCKα all promote TNFα protein expression. The p65 subunit of NF-κB coprecipitates with RhoA in a manner sensitive to the RhoA activation state. Our findings suggest a new, 2-faced role for RhoA as a checkpoint in innate immunity.
Selection and characterization of RNA aptamers to the RNA-dependent RNA polymerase from foot-and-mouth disease virus
Authors: Ellingham Mark , Bunka David H.J. , Rowlands David J. , Stonehouse Nicola J.
Published: October 2006

Foot-and-mouth disease virus causes a highly contagious disease of agricultural livestock and is of enormous economic importance. Replication of the RNA genome of the virus, via negative strand intermediates, involves an RNA-dependent RNA polymerase (3Dpol). RNA aptamers specific to this enzyme have been selected and characterized. Some of these molecules inhibit enzymatic activity in vitro, with IC50 values of <20 nM and Ki values of 18–75 nM. Two of these show similarity, both with each other and with regions of the viral genome. Furthermore, truncated versions of one of the aptamers have been used to define the parts of the molecule responsible for its inhibitory activity.
Otosclerosis and meniere's syndrome: Diagnosis and treatment
Authors: Paparella Michael M. , Mancini Fernando , Liston Stephen L.
Published: October 2006

Occasionally a patient with otosclcrosis and a conductive hearing loss will develop typical findings of Meniere's syndrome in the involved car, years later. A review of clinical and pathological studies in the literature and in our laboratory and clinic indicates a likely cause‐and‐effect relationship for these cases. The pathology and pathogenesis of the syndrome of otosclcrosis and Meniere's syndrome is discussed. A stapedectomy/sacculotomy was used to treat 17 patients, 13 of whom acquired a satisfactory result in terms of improvement of hearing and control of vertigo. This technique and findings are described and discussed.
Cash flow estimation for real option analysis using Margrabe's model
Authors: Andor György , Bóta Gábor
Published: October 2006

This paper looks at how the parameters for real option analysis can be extracted from the general capital budget of a project and discusses how the estimated cash flows of a general project can be used for a real option analysis. A project is described where it is possible to stop the business operation in case of predicting a loss for the next year. Our model shows how the cash flow of the period influenced by the option-like decision has to be separated in order to get the exercise price and the price of the underlying asset for real option valuation. Besides providing arguments against the suitability of the general Black-Scholes formula for real option situations, the paper also shows how Margrabe's exchange option valuation formula may be used, and how the volatility as a parameter of this model can be calculated from the data available about the project.
Taylor's Fiscal Rule: An Exit to the Stability and Growth Pact Dead-end?
Authors: Farvaque Etienne , Huart Florence , Vaneecloo Clément
Published: October 2006

This study applies Taylor's (2000) proposed fiscal rule to EU-15 countries. We show that such a simple, flexible and transparent fiscal rule, if applied to individual EMU countries, could improve the enforceability of the Stability and Growth Pact. This rule is used to compute the structural budget balance consistent with a total budget position in balance, given national specificities concerning automatic stabilisers and the output gap. It is thus designed for being consistent with both fiscal discipline and flexibility.
Three-dimensional study of indentation-induced cracks in an amorphous carbon coating on a steel substrate
Authors: Xie Z-H. , Munroe P.R. , McGrouther D. , Singh R.K. , Hoffman M. , Bendavid A. , Martin P.J. , Yew S.
Published: October 2006

An amorphous carbon coating, approximately 1.7 μm thick, deposited onto a ductile steel substrate, was indented using a 5-μm radius spherical-tipped diamond indenter to a maximum load of 150 mN. Displacement discontinuities were observed during loading, indicative of crack formation in the system. After indentation, a focused ion beam instrument was used to prepare cross-sections, which revealed the presence of ring, radial, and lateral cracks. A three-dimensional reconstruction of the deformation zone beneath the indent was conducted using a dual ion/electron beam instrument, assisted by a commercial three-dimensional visualization software package. These three-dimensional images enabled a detailed analysis of indentation-induced cracking in this film at submicron resolution. In contrast to traditional understanding and modeling, it was observed that the development of ring cracks was asymmetric for this type of coating/substrate system. Based on this observation, it can be deduced that the strain energy release rate was different for the growth of the spiral ring crack compared with the traditional concentric-ring model. Consequently, the concentric ring-crack fracture model may not be appropriate for the evaluation of the fracture toughness of this type of coating. Hence, three-dimensional images have presented a requirement that the asymmetrical nature of ring and radial cracks should be addressed and carefully considered in the fracture mechanics analysis of this type of hard coating system.
Monolithic nanoporous copper by dealloying Mn–Cu
Authors: Hayes J.R. , Hodge A.M. , Biener J. , Hamza A.V. , Sieradzki K.
Published: October 2006

Monolithic nanoporous copper was synthesized by dealloying Mn0.7Cu0.3 by two distinct methods: potentiostatically driven dealloying and free corrosion. Both the ligament size and morphology were found to be highly dependent on the dealloying methods and conditions. For example, ligaments from 16 nm–125 nm were obtained by dealloying either electrochemically or by free corrosion, respectively. Optimization of the starting Mn–Cu alloy microstructure allowed us to synthesize uniform porous structures; but we found cracking to be unavoidable. Despite the presence of unavoidable defects, the nanoporous material still exhibits higher than expected yield strength.
Correlated Response in Plant Height and Heading Date to Selection in Perennial Ryegrass Populations
Authors: Hazard Laurent , Betin Michèle , Molinari Nicolas
Published: October 2006

Understanding how management practices apply selective pressures that shape adaptive traits in forage grass is essential for managing genetic resources and breeding improved cultivars. The defoliation regime, for instance, induces a genotypic differentiation in plant height and heading. To explore these changes, plant height, heading date, and their relationship were studied in a nursery experiment among populations of perennial ryegrass (Lolium perenne L.) that had experienced different selection pressures: the cultivar ‘Clerpin’ from the original seed lot and its derived population from a pasture intensively grazed, 23 commercial cultivars, and 86 families coming from a divergent and recurrent mass selection for leaf length. A controlled experiment was performed on two populations contrasted on both plant height and heading date to compare their phyllochron, leaf elongation rate, leaf elongation duration, tiller number, and biomass per plant. Dissections were performed to monitor apex development and stem elongation. Genetic differentiations in plant height and heading date were found as a result of grazing pressure, commercial breeding, and selection for leaf length. Heading date was negatively correlated to plant height. Delayed flowering and reduction in plant stature resulted from a reduction in both leaf and stem elongation rate and were associated with a delay in the production of double ridge at the apex level. Selecting for a short plant resulted in an overall decrease in both vegetative and reproductive plant growth. Genetic differentiation in heading date in response to defoliation regime could be interpreted as an indirect effect of an adaptive differentiation in plant height.
Yield Response of Indeterminate Potato (Solanum tuberosum L.) to Simulated Insect Defoliation
Authors: Ziems Jesse R. , Zechmann Benjamin J. , Hoback W. Wyatt , Wallace John C. , Madsen Rod A. , Hunt Thomas E. , Higley Leon G.
Published: October 2006

Yield response to insect defoliation is primarily a function of light interception. A series of leaf removal experiments were conducted on an indeterminate chipping variety of Irish potato, Solanum tuberosum L., to simulate late‐season insect defoliation injuries. Leaf removal was conducted following a computer simulation model for growing insect populations. Across 2 yr, 50 to 75% of the canopy leaf area was removed during a 10‐d period. In 2001, 75% leaf removal resulted in a 14% yield loss (in total potato weight) while in 2002, 50% defoliation resulted in 15% yield loss and 75% leaf removal resulted in 22% yield loss. In addition to yield differences, high defoliation reduced number and weight of large (65–100 mm diam.) tubers and increased the number of small tubers (47–64 mm diam.). Yield loss was significant when defoliated canopies remained below a leaf area index (LAI) of 4.0. Percentage light interception was a better predictor of potato yield than was percentage defoliation. These data are consistent with the light interception hypothesis and show that remaining leaf area is a better predictor of yield potential than percentage defoliation. Thus, treatment decisions based on light interception and LAIs rather than estimates of percentage defoliation should be applicable to indeterminate varieties of potato.
Grain Yield and Milling Quality Response of Two Rice Cultivars to Top‐Dress Nitrogen Application Timings
Authors: Walker Timothy W. , Martin Steven W. , Gerard Patrick D.
Published: October 2006

Combinations of two vegetative N application schemes (single pre‐flood [SPF]) and two‐way split [2WS]) and five top‐dress (TD) N timings (internode elongation [IE], IE+7, 14, 21, and 28 d) were tested for ‘Cocodrie’ and ‘Wells’ rice. When averaged across TD timings, the average grain yield for Cocodrie was 9142 kg ha−1 when the SPF scheme was used, compared with 8736 kg ha−1 for the 2WS scheme. Whole and total milled rice percentage showed a quadratic response to TD timing and was greatest when the TD application was made at IE+28 d for Cocodrie; however, only the early vegetative N application scheme affected the net return, which, when averaged across TD timings, was $75 ha−1 greater when the SPF scheme was used. When N was top‐dressed at the IE timing, whole milled rice was 52.9% with the SPF scheme, compared with 49.8% with the 2WS scheme. In addition, where the SPF scheme was used, whole milled rice responded quadratically to TD timing compared with linearly when the 2WS scheme was used. Sensitivity analyses indicated that at three N prices ($0.16, $0.33, and $0.48 kg−1), the relative difference in net returns among treatment combinations were not changed. Rice grain yields for semi‐dwarf cultivars respond more favorably to a higher percentage of the total N being applied pre‐flood. Growers should implement N fertilizer practices that produce the highest economic grain yield, which for Cocodrie is to use the SPF vegetative N application scheme regardless of the TD N timing.
Allelopathic, Autotoxic, and Hormetic Effects of Postharvest Sugarcane Residue
Authors: Viator Ryan P. , Johnson Richard M. , Grimm Casey C. , Richard Edward P.
Published: October 2006

With green sugarcane (interspecific hybrids of Saccharum spp.) harvesting, 6 to 24 Mg ha−1 of postharvest residue is deposited on the field surface covering the sugarcane stubble that must reemerge for several ratoon crops. The objectives of this research were to: (i) determine if postharvest residue possesses allelopathic, autotoxic, and hormetic properties; (ii) determine the interaction of soil type with possible autotoxic effects; and (iii) identify a reliable indicator species. Extract concentrations consisted of 0, 0.1, 10, 25, and 100% of the original solution of a 1:28 tissue to water extract. The higher concentrations of residue extracts exhibited autotoxicity by delaying early leaf development. The lower extract concentration of 10% increased sugarcane bud germination by 45% compared with the control, indicating hormetic effects. Allelopathic activity on tall morninglory (Ipomoea hederacea Jacq.) was more pronounced on a light soil; germination and radical length were reduced by all concentrations by an average of 42% and 8 mm, respectively, compared with the control. Seedling dry weights were reduced by an average of 10 mg by the 10, 25, and 100% extract concentrations relative to the control. On the heavy soil, only the 100% concentration reduced radical length and weight by 5 mm and 4 mg, respectively, relative to the control. Extract effects on oat (Avena nuda L.), rye (Secale cereale L.), and tomato (Lycopersicon esculentum Mill.) showed poor correlation with effects on sugarcane. Chemical analysis by gas chromatography/mass spectrotometry indicated the extract contained benzoic acid. Further studies are needed to establish the impact of benzoic acid in natural settings.
Iron Deficiency Chlorosis in Soybean: Soybean Seeding Rate and Companion Crop Effects
Authors: Naeve Seth L.
Published: October 2006

Iron deficiency chlorosis (IDC) is an important production problem in soybean [Glycine max (L.) Merr.] grown in the upper Midwest. Although IDC‐tolerant varieties are available to producers, even tolerant cultivars suffer from IDC‐related stresses. Several cultural methods have been utilized in an attempt to reduce IDC losses. Interplant competition from increased soybean seeding rates or companion crops appears to reduce IDC symptoms. Two related studies were established to examine increased seeding rates and the planting of companion crops to reduce IDC of soybean in eight IDC‐prone environments. In one study, soybean was planted at five seeding rates from 432 000 to 926 000 seeds ha−1. In a second study, a glyphosate‐resistant soybean variety was planted as a sole crop or with companion crops of glyphosate‐susceptible soybean or oat (Avena sativa L.). Seeding rate treatments affected IDC scores and yield, but these effects were confounded by environmental interactions. Overall, yield increases from higher seeding rates tended to be small and inconsistent, but among seven environments exhibiting mild to moderate IDC symptoms, increasing seeding rates from 432 000 to 926 000 seeds ha−1 increased yields by 281 kg ha−1 (16%). Blending of a glyphosate‐susceptible with a glyphosate‐resistant variety seemed to have little positive effect on yield of soybean (yield gains varied from −333 to + 566 kg ha−1). Likewise, using oat interseeded with soybean to reduce IDC symptoms and increase soybean yields is unlikely to be a profitable practice for soybean producers.
Anatomic study of the synovial folds of the occipito‐atlanto‐axial joints
Authors: Tang Xue‐Yang , Liu Li‐Jun , Yang Hui‐Jun , Peng Ming‐Xing , Liao Su‐Hua
Published: October 2006

This study was performed to observe and measure synovial folds of the occipito‐atlanto‐axial joints and to explore their clinical significance. Two hundred ninety eight occipito‐atlanto‐axial joints from 30 embalmed cadavers of children and 20 of adults were dissected to find the incidence, quantity, distribution, forms, dimension, and histology of synovial folds. Synovial folds were found in most joints in both groups except for the posterior median atlantoaxial joints. Most of synovial folds were crescent‐shaped, distributed on the superior aspects of the anterior median atlantoaxial joints, or in the antero‐lateral aspects of the atlantooccipital joints and the lateral atlantoaxial joints. Compared to the adult group, the child group had a higher incidence of synovial folds (72.5% joints). The adult incidence was found to be 58.5%. 54.3% of the synovial folds in child were medium size or large size, but only 30.1% of the synovial folds in adult were medium size and there were no large ones. Microscopically, there were three histologic types synovial folds in these cervical joints, and 78.9% of them belonged to adipose type or fibro‐adipose type in child, but only 45.8% belonged to the two types in adult. Our data suggest that the larger synovial folds in children may predispose them to an increased rate of entrapment with resultant edema and subluxation of the associated joint complex. This may be the cause why some cervical spine diseases preferentially take place in children rather than in adult, such as benign paroxysmal torticollis'atlantoaxial rotatory deformity and Grisel's syndrome. Clin. Anat. 20:376–381, 2007. © 2006 Wiley‐Liss, Inc.
Juvenile recurrent respiratory papillomatosis: Still a mystery disease with difficult management
Authors: Stamataki Sofia , Nikolopoulos Thomas P. , Korres Stavros , Felekis Dimitrios , Tzangaroulakis Antonios , Ferekidis Eleftherios
Published: October 2006

Juvenile recurrent respiratory papillomatosis (RRP) is the most common benign neoplastic disease of the larynx in children and adolescents and has a significant impact on patients and the health care system with a cost ranging from $60,000 to $470,000 per patient. The aim of this paper is to review the current literature on RRP and summarize the recent advances. RRP is caused by human papillomavirus (HPV; mainly by types 6 and 11). Patients suffer from wart‐like growths in the aerodigestive tract. The course of the disease is unpredictable. Although spontaneous remission is possible, pulmonary spread and malignant transformation have been reported. Surgical excision, including new methods like the microdebrider, aims to secure an adequate airway and improve and maintain an acceptable voice. Repeated recurrences are common and thus overenthusiastic attempts to eradicate the disease may cause serious complications. When papillomas recur, old and new adjuvant methods may be tried. In addition, recent advances in immune system research may allow us to improve our treatment modalities and prevention strategies. A new vaccine is under trial to prevent HPV infection in women; the strongest risk factor for juvenile RRP is a maternal history of genital warts (transmitted from mother to child during delivery). Better understanding of the etiology of the disease and the knowledge of all available therapies is crucial for the best management of the affected patients. © 2006 Wiley Periodicals, Inc. Head Neck, 2006
Influence of anti‐washout agents on the rheological properties and injectability of a calcium phosphate cement
Authors: Wang Xiupeng , Chen Ling , Xiang Hong , Ye Jiandong
Published: October 2006

Anti‐washout‐type calcium phosphate cement (aw‐CPC) was prepared by introducing chitosan, sodium alginate, or modified starch into the powder phase of CPC, respectively. The results showed that these cements cannot be washed out and set within approximately 10–30 min even if the pastes were immersed in distilled water immediately and were shaken in a shaker after mixing and moulding. To our knowledge, it is the first report about the influence of the content of these anti‐washout additives on the rheological properties and injectability of the cement. Moreover, novel approach of yield stress measurement was used to evaluate the injectability of the pastes. A modified starch was originally used as anti‐washout agent for CPC. This study provided a convenient way to use the injectable CPC with good anti‐washout performance when the paste was exposed to blood. The aw‐CPC had potential prospects for the wider applications in surgery such as orthopaedics, oral, and maxillofacial surgery. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Influence of hernioplastic implants on male fertility in rats
Authors: Kolbe T. , Lechner W.
Published: October 2006

This study explored the vulnerability of the ductus deferens due to mesh induced inflammation and shrinkage after hernia repair in the rodent model. Two commonly used types of hernioplastic implants (Prolene™ and Vypro II™) were surgically wrapped around the ductus deferentes on both sides in 20 juvenile and 20 adult Sprague–Dawley rats. Twenty male rats underwent sham surgeries as controls. After 3 months, each male was mated with 2–3 adult females, which were subsequently sacrificed and oocytes or embryos were flushed and counted. Histochemical investigations of the implants and the ductus recovered surgically 4 weeks after implantation (one side) and after the fertility test (second side) were conducted. All groups exhibited 1–3 males with decreased or restricted fertility but there was no difference between groups. Histochemical analysis of the implants and the ductus recovered 4 weeks and 4 months after implantation revealed some sperm granulomes due to lesions of the spermatic cord caused by the implant in the Prolene™ group. There was no inflammatory reaction in the mucosa or blockage of the spermatic cord visible. Both types of hernioplastic implants tested in this investigation do not give an indication of a negative influence on male fertility in juvenile or adult rats. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Preparation of bentonite–poly[(acrylic acid)‐acrylamide] water superabsorbent by photopolymerization
Authors: Tao Wan , Xiaoqing Wang , Yi Yuan , Wenqiong He
Published: October 2006

A novel bentonite–poly[(acrylic acid)‐acrylamide] superabsorbent composite with water and salt solution absorbencies of 450 and 108 times its own weight, respectively, was successfully synthesized by photopolymerization of acrylic acid with acrylamide in the presence of bentonite powder using 30 min of ultraviolet irradiation at room temperature. The results show a synergetic effect of Michler's ketone and benzophenone mixed photoinitiators on the water absorbency, and incorporation of bentonite below 10 wt% into the water superabsorbent can slightly increase the water and salt solution absorbencies, and improve water retention, as demonstrated using thermogravimetric analysis and differential scanning calorimetry. Fourier transform infrared spectroscopy allowed the determination of the structure of the bentonite composite superabsorbent. Copyright © 2006 Society of Chemical Industry
Importance of charcoal in determining the age and chemistry of organic carbon in surface soils
Authors: Krull Evelyn S. , Swanston Christopher W. , Skjemstad Jan O. , McGowan Janine A.
Published: October 2006

Understanding the chemical character and turnover time of the oldest soil organic carbon (SOC) fraction is fundamental in deciphering soil carbon sequestration processes and the fate of soil‐eroded carbon in aquatic sediments. Two main processes are thought to extend the turnover time of SOC: protection by the mineral matrix and chemical recalcitrance. Various oxidation methods have been proposed to isolate the oldest and most recalcitrant SOC fraction, which is often assumed to be black carbon (BC). However, few data have been published that confirm the chemical character of the isolated fractions. Using established and newly developed methods together with 13C‐NMR spectroscopy and AMS dating, we show that protection by the mineral matrix prolonged the turnover time of SOC by tens of years, but long‐term (hundreds of years) stabilization was controlled by the inherent recalcitrance of SOC, determined by the type of ecosystems. In ecosystem without significant fire occurrences, the older SOC pool was comparably small and was represented by alkyl carbon. In ecosystems with high fire frequency charcoal constituted the oldest SOC pool, and constituted up to 35% of the total SOC. By applying methods with different oxidative strengths, it was possible to isolate different age groups of charcoal with different degrees of weathering. Further substantiation of this finding could provide a much greater resolution of paleo‐fire events. Our results demonstrate that fire frequency plays a dominant role in determining the chemical nature and 14C abundance of SOC and that the separation of age groups of charcoal provides a means to reconstruct detailed fire histories. Our results indicate that modeling SOC turnover, transport and sequestration for frequently burnt environments requires modification of existing models, specifying an input and decay function for the charcoal pool in different environments.
Dissociative photodetachment dynamics of the iodide-aniline cluster
Authors: Bowen M. Shane , Becucci Maurizio , Continetti Robert E.
Published: October 2006

The photodetachment dynamics of the iodide-aniline cluster, I−(C6H5NH2), were investigated using photoelectron-photofragment coincidence spectroscopy at several photon energies between 3.60 and 4.82eV in concert with density functional theory calculations. Direct photodetachment from the solvated I− chromophore and a wavelength-independent autodetachment process were observed. Autodetachment is attributed to a charge-transfer-to-solvent reaction in which incipient continuum electrons photodetached from I− are temporarily captured by the nascent neutral iodine-aniline cluster configured in the anion geometry. Subsequent dissociation of the neutral cluster removes the stabilization, leading to autodetachment of the excess electron. The dependence of the dissociative photodetachment (DPD) and autodetachment dynamics on the final spin-orbit electronic state of the iodine fragment is characterized. The dissociation dynamics of the neutral fragments correlated with autodetached electrons were found to be identical to the DPD dynamics of the I atom product spin-orbit state closest to threshold at a given photon energy, lending support to the proposed sequential mechanism.
Features of the magnetoelectric behavior of the family of multiferroics RMn2O5 at high magnetic fields (Review)
Authors: Kadomtseva A. M. , Krotov S. S. , Popov Yu. F. , Vorob’ev G. P.
Published: October 2006

The family of multiferroics comprised of the orthorhombic manganates RMn2O5 (R=Eu,Gd,Er,Y), in which the coexistence of antiferromagnetism and ferroelectricity has been reported previously, is investigated at high magnetic fields. These compounds, unlike the members of the family RMnO3 (where R=Eu,Ge,Tb,Dy) have two subsystems of magnetic mixed-valence d ions Mn3+ and Mn4+, the direct and indirect interactions between which, being of the ferro- or antiferromagnetic type, depending on the particulars of the environment and properties of the rare-earth ions, enhance substantially the role of the frustrations observed in RMnO3 compounds. These systems, as a consequence of the specific combination of the additional magnetic degeneracy realized in them (due to competition between nearest- and next-nearest-neighbor interactions of nearly equal magnitude) and their strong magnetoelastic coupling, display a cascade of magnetic phase transitions, with the appearance/disappearance of incommensurate (modulated) magnetic structure independently along the a and c axes. The substantial magnetoelectric interactions observed in these systems provide the prerequisites not only for efficiently influencing the phase transitions by means of a magnetic field but also hold forth the possibility of magnetic control of electrical polarization effects.