bluuebunny/crossref_metadata_2025 huggingface dataset:
A Continental Barley Market: Where Are the Gains?
Authors: Gray Richard , Ulrich Alvin , Schmitz Andrew
Published: November 2008

Under a continental barley marketing system, the Canadian Wheat Board would no longer be the only exporter of barley to the United States. Even though the volume of malting barley exports to the United States would increase, the historic price premium in both Canada and the United States would drop sufficiently to lower total revenue to malting barley producers. The United States' Export Enhancement Program allows the Canadian Wheat Board to sell feed barley at premium prices in some markets, including the United States. Under some conditions the continental barley market would adversely affect optimal trade flows and reduce revenue for feed barley producers. The potential to offset these losses in revenue by reducing grain‐handling charges or by growing higher‐yielding feed varieties appears to be very limited.

Dans un système de marché continental de l'brge, la Commission canadienne du blé ne serait plus le seul exportateur d'orge vers les Etats‐Unis. Même si Ie volume des exportations d'orge de malterie augmentait, la prime dont a longtemps bénéficié cette catégorie d'orge, tant au Canada qu'aux Etats‐Unis, tomberait suffisamment pour abaisser les recettes totales des producteurs. Par ailleurs, le Programme américain de stimulation des exportations (EEP) autorise actuellement la CCB à vendre son orge fourragère à prime sur certains marchés, dont les Etats‐his. Dans certaines circonstances, le marché continental de l'orge aurait un effet négatif sur les courants d'échange et réduirait les recettes des producteurs de ce type d'orge. Les possibilités de compenser ces pertes de revenu parune compression des frais de manutention et de stockage ou par la mise en service de variétés fourragères à rendement plus élevé paraissent très restreintes.
The Political Economv of Svstematic Government Intervention in Agriculture
Authors: Sarker Rakhal , Meilke Karl , Hoy Michael
Published: November 2008

There is a systematic pattern of government policy intervention in agriculture by developed and developing countries. This paper attempts to provide a political economy explanation of these policy interventions. A simple political economy model with two interest groups is developed following Becker and Gardner. This framework brings interest group competition formally into the political preference fitnction. In this model, interest groups' competitive lobbying expenditures cause changes in policies by changing the relative political weights. An empirical political economy model is specified and estimated for wheat using data for 12 developed and 13 developing countries from 1958 to 1987. The results suggest that the labor productivity ratio, agriculture's international terms of trade and the share of food in disposable income are the most important factors influencing the systematic subsidization of wheat producers in developed countries, while the factor endowment ratio, agriculture's international terms of trade and the share of imports financed by agricultural exports are the most important factors contributing to the systematic exploitation of wheat producers in developing countries. The results also suggest that the incentive mechanism in agricultural price policy changes gradually.

Il existe un profil systématique des interventions de l'État en agriculture chez les pays industrialisés et chez les pays en développement. L'objet de l'article est de dégager une explication d'économie politique pour ces interventions. Lln modèle simple d'économie politique comportant deux groupes d'intérêt est construit selon la méthode de Becker et Gardner. Le modèle intègre la concurrence des groupes d'intérêt dans lafonction préférence des politiques. Dans ce modèle, les dépenses de lobbying des groupes d'intérêt concurrentiels peuvent provoquer des changements dans les politiques en modifiant le poids politique actuel. Un modèle empirique d'économie politique est construit et évalué pour le bléà partir de données portant sur 12 pays industrialistés et sur 13 pays en développement, de 1958 à 1987. Les résultats laissent voir que le ratio productivité‐travail, les conditions du commerce agricole internutional et la part de l'alimentation dans le revenu disponible sont les facteurs qui influent le plus sur le subventionnement systematique des producteurs de blé dans les pays industrialisés. En revanche, dans les pays en développement, le ratio dotation en facteurs (terre agricole par ouvrier agricole), les conditions du commerce international en agriculture et la part des importations financée par les exportations agricoles sont celles qui contribuent le plus à l'expoitation systématique des producteurs de blé. Les résultats font voir aussi que les mécanisrnes d'incitation attachés aux politiques d'établissement des prix agricoles changent graduellement.
‘57 Varieties of Serious Defect in IFRS?’
Authors: Nobes Christopher
Published: November 2008

In a previous issue of this journal, Haswell and Langfield‐Smith (HLS) recorded 57 ‘serious defects' in IFRS. This commentary suggests that some of these are not defects and some others are not serious. Points are also made about the different implementation dates of standards in Australia compared to elsewhere, and about HLS's comparison of IFRS and previous Australian standards. HLS's conclusion that IFRS is not yet ready for world‐wide adoption is challenged on the grounds that a world standard is already needed for listed companies and that no plausible alternative to IFRS would be better.
What Drives TBL Reporting: Good Governance or Threat to Legitimacy?
Authors: Kent Pamela , Monem Reza
Published: November 2008

This paper provides two complementary explanations for the adoption of triple bottom line (TBL) reporting by Australian companies. The first explanation is that companies adopt TBL reporting to legitimise their relationship with society because of adverse publicity from the media. The second explanation is that TBL reporting is adopted because of the company's desire to achieve high‐quality reporting and transparency inferred by strong corporate governance. Companies with TBL reporting had significantly more adverse media coverage before implementing TBL reporting than non‐TBL companies. TBL reporting is also significantly and positively related to the existence of an environmental or sustainable development committee and the frequency of meetings of the audit committee.
Hepatic arterial infusion chemotherapy for advanced hepatocellular carcinoma: Is the addition of subcutaneous interferon‐α‐2b beneficial?
Authors: Takaki‐Hamabe Satoe , Yamasaki Takahiro , Saeki Issei , Harima Yohei , Okita Kohsuke , Terai Shuji , Sakaida Isao
Published: November 2008

Aim:  We previously reported the benefits of hepatic arterial infusion chemotherapy (HAIC) using cisplatin (CDDP), 5‐fluorouracil (5‐FU) [low‐dose FP], and leucovorin/isovorin for advanced hepatocellular carcinoma (HCC). In this study, we investigated the efficacy of combination therapy with HAIC and subcutaneous interferon (IFN)‐ α‐2b in patients with advanced HCC.

Methods:  Of the 48 patients, 31 received low‐dose FP with leucovorin/isovorin (HAIC group) and 17 received combination therapy comprising low‐dose FP with isovorin and subcutaneous IFN‐α‐2b (combination group). Prognostic factors were evaluated by univariate and multivariate analyses of the patient and the disease characteristics.

Results:  There were no significant differences in the response rate (patients with complete or partial response/all patients; P = 0.736) and survival (P = 0.399) between both groups. Univariate analysis revealed that IFN therapy was not a significant prognostic factor. Multivariate analysis showed 3 variables, namely, Child–Pugh score (P = 0.010), α‐fetoprotein level (P = 0.0047), and additional therapy (P = 0.002), to be significant prognostic factors.

Conclusions:  We considered that combination therapy with HAIC and subcutaneous interferon (IFN)‐α‐2b was not beneficial for advanced HCC.
Batf3
Deficiency Reveals a Critical Role for CD8α
+
Dendritic Cells in Cytotoxic T Cell Immunity
Authors: Hildner Kai , Edelson Brian T. , Purtha Whitney E. , Diamond Mark , Matsushita Hirokazu , Kohyama Masako , Calderon Boris , Schraml Barbara U. , Unanue Emil R. , Diamond Michael S. , Schreiber Robert D. , Murphy Theresa L. , Murphy Kenneth M.
Published: November 2008

Although in vitro observations suggest that cross-presentation of antigens is mediated primarily by CD8α
+
dendritic cells, in vivo analysis has been hampered by the lack of systems that selectively eliminate this cell lineage. We show that deletion of the transcription factor
Batf3
ablated development of CD8α
+
dendritic cells, allowing us to examine their role in immunity in vivo. Dendritic cells from
Batf3
–/–
mice were defective in cross-presentation, and
Batf3
–/–
mice lacked virus-specific CD8
+
T cell responses to West Nile virus. Importantly, rejection of highly immunogenic syngeneic tumors was impaired in
Batf3
–/–
mice. These results suggest an important role for CD8α
+
dendritic cells and cross-presentation in responses to viruses and in tumor rejection.
Thermodynamics and Density of Binding of a Panel of Antibodies to High-Molecular-Weight Capsular Polysaccharides
Authors: Harris Shannon L. , Fernsten Philip
Published: November 2008

The interaction between antipolysaccharide (anti-PS) antibodies and their antigens was investigated by the use of isothermal titration calorimetry to determine the thermodynamic binding constant (K), the change in the enthalpy of binding (ΔH), and the binding density (N) to high-molecular-weight PSs. From these values, the change in the entropy of binding (ΔS) was calculated. The thermodynamic parameters of binding to high-molecular-weight capsular PSs are reported for two monoclonal antibodies (MAbs) with different specificities for meningococcal serogroup C PS, five MAbs specific for different pneumococcal serotypes, and the Fab fragments of two antipneumococcal MAbs. TheKvalues were in the range of 106to 107M−1, and these values were 1 to 2 orders of magnitude greater than the previously reportedKvalues derived from antibody-oligosaccharide interactions. The ΔHassociated with binding was favorable for each MAb and Fab fragment. The ΔSassociated with binding was also generally favorable for both the MAbs and the Fab fragments, with the exception of the anti-serotype 14 MAb and its Fab fragment.Nprovides information regarding how densely MAbs or Fabs can bind along PS chains and, as expressed in terms of monosaccharides, was very similar for the seven MAbs, with an average of 12 monosaccharides per bound MAb. The value ofNfor each Fab was smaller, with five or seven monosaccharides per bound Fab. These results suggest that steric interactions between antibody molecules are a major influence on the values ofNof high-affinity MAbs to capsular PSs.
Peptide-Based Antibody Detection for Tuberculosis Diagnosis
Authors: Shen Guomiao , Behera Digambar , Bhalla Manpreet , Nadas Arthur , Laal Suman
Published: November 2008

Tuberculosis (TB) is a major cause of morbidity and mortality, especially in developing countries. Despite significant limitations, microscopy remains the cornerstone of the global TB control strategy. As the TB epidemic escalates, new diagnostic methods that are accurate and also economical and simple to manufacture and deploy are urgently needed. Although several promising antigens have been identified and evaluated in recent years, the reproducible production of high-quality recombinant mycobacterial proteins with minimal batch-to-batch variation is difficult, laborious, and expensive. To determine the feasibility of devising a synthetic peptide-based diagnostic test for TB, we have delineated the immunodominant epitopes of three candidate antigens, Ag85B, BfrB, and TrxC, that were previously identified to be immunogenic in TB patients. The results demonstrate that combinations of carefully selected synthetic peptides derived from highly immunogenic proteins can be the basis for devising an immunodiagnostic test for TB.
Evaluation of the Rapid BioStar Optical Immunoassay for Detection of
Chlamydia trachomatis
in Adolescent Women
Authors: Bandea Claudiu I. , Koumans Emilia H. , Sawyer Mary K. , Dover Jason , O'Connor Angelica , Papp John R. , Unger Elizabeth R. , Braxton Jim , Black Carolyn M.
Published: November 2008

We evaluated the performance of the BioStar Chlamydia OIA (optical immunoassay) in adolescent females (
n
= 261) from an inner city population. With a reference standard of two different nucleic acid amplification tests, the sensitivity and specificity of the BioStar Chlamydia OIA were 59.4 and 98.4%, respectively. Due to its relatively low sensitivity, the BioStar Chlamydia OIA should only be used in conjunction with more sensitive laboratory tests unless laboratory tests are unavailable or timely return for treatment is unlikely.
Effect of ThinPrep Preparation on
Human papillomavirus
Detection and Genotyping in Rectal Samples by PCR
Authors: Tabrizi Sepehr N. , Stevens Matthew P. , van Leeuwen Marina T. , Vajdic Claire M. , Botes Leon P. , Medley Gabriele , Hillman Richard , Grulich Andrew , Garland Suzanne M.
Published: November 2008

Specimen-to-specimen carryover during ThinPrep slide preparation was evaluated by comparing human papillomavirus genotypes detected prior and subsequent to the ThinPrep processing of 121 PreservCyt samples. Overall, 52 samples generated concordant genotypes and 38 had additional and 21 had fewer genotypes postprocessing. PreservCyt samples should be aliquoted for PCR testing prior to ThinPrep processing.
Loop-Mediated Isothermal Amplification Method for Differentiation and Rapid Detection of
Taenia
Species
Authors: Nkouawa Agathe , Sako Yasuhito , Nakao Minoru , Nakaya Kazuhiro , Ito Akira
Published: November 2008

Rapid detection and differentiation of
Taenia
species are required for the control and prevention of taeniasis and cysticercosis in areas where these diseases are endemic. Because of the lower sensitivity and specificity of the conventional diagnosis based on microscopical examination, molecular tools are more reliable for differential diagnosis of these diseases. In this study, we developed and evaluated a loop-mediated isothermal amplification (LAMP) assay for differential diagnosis of infections with
Taenia
species with cathepsin L-like cysteine peptidase (clp) and cytochrome
c
oxidase subunit 1 (cox1) genes. LAMP with primer sets to the cox1 gene could differentiate between three species, and LAMP with primer sets to the clp gene could differentiate
Taenia solium
from
Taenia saginata
/
Taenia asiatica
. Restriction enzyme digestion of the LAMP products from primer set Tsag-clp allowed the differentiation of
Taenia saginata
from
Taenia asiatica
. We demonstrated the high specificity of LAMP by testing known parasite DNA samples extracted from proglottids (
n
= 100) and cysticerci (
n
= 68). LAMP could detect one copy of the target gene or five eggs of
T. asiatica
and
T. saginata
per gram of feces, showing sensitivity similar to that of PCR methods. Furthermore, LAMP could detect parasite DNA in all taeniid egg-positive fecal samples (
n
= 6). Due to the rapid, simple, specific, and sensitive detection of
Taenia
species, the LAMP assays are valuable tools which might be easily applicable for the control and prevention of taeniasis and cysticercosis in countries where these diseases are endemic.
High Prevalence of Human Parvovirus B19 DNA in Myocardial Autopsy Samples from Subjects without Myocarditis or Dilative Cardiomyopathy
Authors: Schenk Thomas , Enders Martin , Pollak Stefan , Hahn Ralph , Huzly Daniela
Published: November 2008

Human parvovirus B19 has been linked to a variety of cardiac diseases, as well as to erythema infectiosum, acute arthropathy, and fetal hydrops. A causal association between viral infection and cardiac disease was frequently postulated following the detection of B19 DNA by PCR in endomyocardial biopsy specimens. Since the lifelong persistence of B19 DNA in bone marrow, skin, synovia, tonsils, and liver was previously reported, the aim of our study was to investigate the possibility of asymptomatic B19 DNA persistence in heart tissue. Myocardial autopsy and postmortem blood samples were prospectively collected from 69 bodies sent to the Department of Forensic Medicine, Freiburg University Medical Center, for inquests. All study subjects were screened for B19-specific antibodies using a commercial enzyme immunoassay. Tissue samples were analyzed by real-time PCR for the presence of viral DNA. Since the presence of B19 genotype 2, known to have been circulating before 1960, would prove long-lasting persistence, the presence of the B19 genotype was retrospectively determined in seven of the study subjects by melting temperature analysis and sequencing of the PCR product. B19 DNA was found in myocardial samples from 46 of 48 seropositive and in none of 21 seronegative individuals. B19 genotype 1 was found in three patients born between 1950 and 1969. Genotype 2 was found in four patients born between 1927 and 1957. Our findings suggest lifelong persistence of B19 DNA in heart tissue. Thus, the detection of B19 DNA in myocardial biopsy specimens alone is not sufficient to postulate a relationship between B19 infection and cardiac disease.
Campylobacter
Immunity and Coinfection following a Large Outbreak in a Farming Community
Authors: Forbes K. J. , Gormley F. J. , Dallas J. F. , Labovitiadi O. , MacRae M. , Owen R. J. , Richardson J. , Strachan N. J. C. , Cowden J. M. , Ogden I. D. , McGuigan C. C.
Published: November 2008

An outbreak of campylobacteriosis affected approximately one-half of 165 people attending an annual farmers' dance in Montrose, Scotland, in November 2005. Epidemiological investigations, including a cohort study (
n
= 164), identified chicken liver paté as the most likely vehicle of infection. Paté preparation involved deliberate undercooking of chicken livers by flash-frying, followed by mechanical homogenization. Typing of 32
Campylobacter
strains (isolated from submitted stools) by multilocus sequence typing identified four distinct clades of
Campylobacter jejuni
. There was good agreement when isolates were typed by Penner serotyping, pulsed-field gel electrophoresis, and
flaA
short variable region sequencing but poorer agreement with phage and antibiotic susceptibility testing. At least three attendees were coinfected with two
Campylobacter
strains each. The outbreak was probably due to several livers contributing
Campylobacter
strains that survived undercooking and were dispersed throughout the paté. The study highlights improper culinary procedures as a potential human health risk and provides a striking counterexample to the “dominant outbreak strain” view of point source outbreaks of food-borne infections. It also demonstrates that previous exposure to biologically plausible sources of
Campylobacter
may confer protection against subsequent infection.
Results from the ARTEMIS DISK Global Antifungal Surveillance Study, 1997 to 2007: 10.5-Year Analysis of Susceptibilities of Noncandidal Yeast Species to Fluconazole and Voriconazole Determined by CLSI Standardized Disk Diffusion Testing
Authors: Pfaller M. A. , Diekema D. J. , Gibbs D. L. , Newell V. A. , Bijie H. , Dzierzanowska D. , Klimko N. N. , Letscher-Bru V. , Lisalova M. , Muehlethaler K. , Rennison C. , Zaidi M.
Published: November 2008

Fluconazole in vitro susceptibility test results determined by the CLSI M44-A disk diffusion method for 11,240 isolates of noncandidal yeasts were collected from 134 study sites in 40 countries from June 1997 through December 2007. Data were collected for 8,717 yeast isolates tested with voriconazole from 2001 through 2007. A total of 22 different species/organism groups were isolated, of which
Cryptococcus neoformans
was the most common (31.2% of all isolates). Overall,
Cryptococcus
(32.9%),
Saccharomyces
(11.7%),
Trichosporon
(10.6%), and
Rhodotorula
(4.1%) were the most commonly identified genera. The overall percentages of isolates in each category (susceptible, susceptible dose dependent, and resistant) were 78.0%, 9.5%, and 12.5% and 92.7%, 2.3%, and 5.0% for fluconazole and voriconazole, respectively. Less than 30% of fluconazole-resistant isolates of
Cryptococcus
spp.,
Cryptococcus albidus
,
Cryptococcus laurentii
,
Trichosporon beigelii/Trichosporon cutaneum
,
Rhodotorula
spp.,
Rhodotorula rubra/Rhodotorula mucilaginosa
, and
Rhodotorula glutinis
remained susceptible to voriconazole. Emerging resistance to fluconazole was documented among isolates of
C. neoformans
from the Asia-Pacific, Africa/Middle East, and Latin American regions but not among isolates from Europe or North America. This survey documents the continuing broad spectrum of activity of voriconazole against opportunistic yeast pathogens but identifies several of the less common species with decreased azole susceptibility. These organisms may pose a future threat to optimal antifungal therapy and emphasize the importance of prompt and accurate species identification.
Genotyping of
Chlamydophila psittaci
by Real-Time PCR and High-Resolution Melt Analysis
Authors: Mitchell Stephanie L. , Wolff Bernard J. , Thacker W. Lanier , Ciembor Paula G. , Gregory Christopher R. , Everett Karin D. E. , Ritchie Branson W. , Winchell Jonas M.
Published: November 2008

Human infection with
Chlamydophila
(
Chlamydia
)
psittaci
can lead to psittacosis, a disease that occasionally results in severe pneumonia and other medical complications.
C. psittaci
is currently grouped into seven avian genotypes: A through F and E/B. Serological testing, outer membrane protein A (
ompA
) gene sequencing, and restriction fragment length polymorphism analysis are currently used for distinguishing these genotypes. Although accurate, these methods are time-consuming and require multiple confirmatory tests. By targeting the
ompA
gene, a real-time PCR assay has been developed to rapidly detect and genotype
C. psittaci
by light-upon-extension chemistry and high-resolution melt analysis. Using this assay, we screened 169 animal specimens; 98 were positive for
C. psittaci
(71.4% genotype A, 3.1% genotype B, 4.1% genotype E, and 21.4% unable to be typed). This test may provide insight into the distribution of each genotype among specific hosts and provide epidemiological and epizootiological data in human and mammalian/avian cases. This diagnostic assay may also have veterinary applications during chlamydial outbreaks, particularly with respect to identifying the sources and tracking the movements of a particular genotype when multiple animal facilities are affected.
Double-Stranded RNA Analog Poly(I:C) Inhibits Human Immunodeficiency Virus Amplification in Dendritic Cells via Type I Interferon-Mediated Activation of APOBEC3G
Authors: Trapp Susanna , Derby Nina R. , Singer Rachel , Shaw Andrew , Williams Vennansha G. , Turville Stuart G. , Bess Julian W. , Lifson Jeffrey D. , Robbiani Melissa
Published: November 2008

Human immunodeficiency virus (HIV) is taken up by and replicates in immature dendritic cells (imDCs), which can then transfer virus to T cells, amplifying the infection. Strategies known to boost DC function were tested for their ability to overcome this exploitation when added after HIV exposure. Poly(I:C), but not single-stranded RNA (ssRNA) or a standard DC maturation cocktail, elicited type I interferon (IFN) and interleukin-12 (IL-12) p70 production and the appearance of unique small (15- to 20-kDa) fragments of APOBEC3G (A3G) and impeded HIV
Bal
replication in imDCs when added up to 60 h after virus exposure. Comparable effects were mediated by recombinant alpha/beta IFN (IFN-α/β). Neutralizing the anti-IFN-α/β receptor reversed poly(I:C)-induced inhibition of HIV replication and blocked the appearance of the small A3G proteins. The poly(I:C)-induced appearance of small A3G proteins was not accompanied by significant differences in A3G mRNA or A3G monomer expression. Small interfering RNA (siRNA) knockdown of A3G could not be used to reverse the poly(I:C)-induced protective effect, since siRNAs nonspecifically activated the DCs, inducing the appearance of the small A3G proteins and inhibiting HIV infection. Notably, the appearance of small A3G proteins coincided with the shift of high-molecular-mass inactive A3G complexes to the low-molecular-mass (LMM) active A3G complexes. The unique immune stimulation by poly(I:C) with its antiviral effects on imDCs marked by the expression of IFN-α/β and active LMM A3G renders poly(I:C) a promising novel strategy to combat early HIV infection in vivo.
Coadministration of Cidofovir and Smallpox Vaccine Reduced Vaccination Side Effects but Interfered with Vaccine-Elicited Immune Responses and Immunity to Monkeypox
Authors: Wei Huiyong , Huang Dan , Fortman Jeff , Wang Richard , Shao Linyun , Chen Zheng W.
Published: November 2008

While the smallpox vaccine, Dryvax or Dryvax-derived ACAM2000, holds potential for public immunization against the spread of smallpox by bioterror, there is serious concern about Dryvax-mediated side effects. Here, we report that a single-dose vaccination regimen comprised of Dryvax and an antiviral agent, cidofovir, could reduce vaccinia viral loads after vaccination and significantly control Dryvax vaccination side effects. However, coadministration of cidofovir and Dryvax also reduced vaccine-elicited immune responses of antibody and T effector cells despite the fact that the reduced priming could be boosted as a recall response after monkeypox virus challenge. Evaluations of four different aspects of vaccine efficacy showed that coadministration of cidofovir and Dryvax compromised the Dryvax-induced immunity against monkeypox, although the covaccinated monkeys exhibited measurable protection against monkeypox compared to that of naïve controls. Thus, the single-dose coadministration of cidofovir and Dryvax effectively controlled vaccination side effects but significantly compromised vaccine-elicited immune responses and vaccine-induced immunity to monkeypox.
Human Immunodeficiency Virus Type 1 Env Trimer Immunization of Macaques and Impact of Priming with Viral Vector or Stabilized Core Protein
Authors: Mörner Andreas , Douagi Iyadh , Forsell Mattias N. E. , Sundling Christopher , Dosenovic Pia , O'Dell Sijy , Dey Barna , Kwong Peter D. , Voss Gerald , Thorstensson Rigmor , Mascola John R. , Wyatt Richard T. , Karlsson Hedestam Gunilla B.
Published: November 2008

Currently there is limited information about the quality of immune responses elicited by candidate human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env)-based immunogens in primates. Here we describe a comprehensive analysis of neutralizing antibody and T-cell responses obtained in cynomolgus macaques by three selected immunization regimens. We used the previously described YU2-based gp140 protein trimers administered in an adjuvant, preceded by two distinct priming strategies: either alphavirus replicon particles expressing matched gp140 trimers or gp120 core proteins stabilized in the CD4-bound conformation. The rationale for priming with replicon particles was to evaluate the impact of the expression platform on trimer immunogenicity. The stable core proteins were chosen in an attempt to expand selectively lymphocytes recognizing common determinants between the core and trimers to broaden the immune response. The results presented here demonstrate that the platform by which Env trimers were delivered in the priming (either protein or replicon vector) had little impact on the overall immune response. In contrast, priming with stable core proteins followed by a trimer boost strikingly focused the T-cell response on the core sequences of HIV-1 Env. The specificity of the T-cell response was distinctly different from that of the responses obtained in animals immunized with trimers alone and was shown to be mediated by CD4
+
T cells. However, this regimen showed limited or no improvement in the neutralizing antibody responses, suggesting that further immunogen design efforts are required to successfully focus the B-cell response on conserved neutralizing determinants of HIV-1 Env.
A Single Amino Acid Substitution in a Segment of the CA Protein within Gag That Has Similarity to Human Immunodeficiency Virus Type 1 Blocks Infectivity of a Human Endogenous Retrovirus K Provirus in the Human Genome
Authors: Heslin David J. , Murcia Pablo , Arnaud Frederick , Van Doorslaer Koenraad , Palmarini Massimo , Lenz Jack
Published: November 2008

Human endogenous retrovirus K (HERV-K) is the most intact retrovirus in the human genome. However, no single HERV-K provirus in the human genome today appears to be infectious. Since the Gag protein is the central component for the production of retrovirus particles, we investigated the abilities of Gag from two HERV-K proviruses to support production of virus-like particles and viral infectivity. HERV-K113 has full-length open reading frames for all viral proteins, while HERV-K101 has a full-length
gag
open reading frame and is expressed in human male germ cell tumors. The Gag of HERV-K101 allowed production of viral particles and infectivity, although at lower levels than observed with a consensus sequence Gag. Thus, including HERV-K109, at least two HERV-K proviruses in human genome today have functional Gag proteins. In contrast, HERV-K113 Gag supported only very low levels of particle production, and no infectivity was detectable due to a single amino acid substitution (I516M) near the extreme C terminus of the CA protein within Gag. The sequence of this portion of HERV-K CA showed similarities to that of human immunodeficiency virus type 1 and other primate immunodeficiency viruses. The extreme C terminus of CA may be a general determinant of retrovirus particle production. In addition, precise mapping of the defects in HERV-K proviruses as was done here identifies the key polymorphisms that need to be analyzed to assess the possible existence of infectious HERV-K alleles within the human population.
Optimization of Human Immunodeficiency Virus Gag Expression by Newcastle Disease Virus Vectors for the Induction of Potent Immune Responses
Authors: Carnero Elena , Li Wenjing , Borderia Antonio V. , Moltedo Bruno , Moran Thomas , García-Sastre Adolfo
Published: November 2008

One attractive strategy for the development of a human immunodeficiency virus (HIV) vaccine is the use of viral vectors with a proven safety profile and an absence of preexisting immunity in humans, such as Newcastle disease virus (NDV). Several NDV vaccine vectors have been generated, and their immunogenicities have been investigated with different animal models. However, a systematic study to evaluate the optimal insertion site of the foreign antigens into NDV that results in enhanced immune responses specific to the antigen has not yet been conducted. In this article, we describe the ability of NDV expressing HIV Gag to generate a Gag-specific immune response in mice. We also have determined the optimal insertion site into the NDV genome by generating recombinant NDV-HIVGag viruses in which HIVgagwas located at different transcriptional positions throughout the NDV viral genome. All recombinant viruses were viable, grew to similar titers in embryonated chicken eggs, and expressed Gag in a stable manner. Our in vivo experiments revealed that higher HIV Gag protein expression positively correlates with an enhanced CD8+T-cell-mediated immune response and protective immunity against challenge with vaccinia virus expressing HIV Gag. We also inserted a codon-optimized version of HIVgagin the described best location, between the P and M genes. Virus expressing the codon-optimized version of HIVgaginduced a higher expression of the protein and an enhanced immune response against HIV Gag in mice. These results indicate that strategies directed toward increasing antigen expression by NDV result in enhanced immunogenicity and vaccine efficacy.
The Mdm2 Ubiquitin Ligase Enhances Transcriptional Activity of Human Papillomavirus E2
Authors: Gammoh Noor , Gardiol Daniela , Massimi Paola , Banks Lawrence
Published: November 2008

The regulation of human papillomavirus (HPV) gene expression by the E2 protein is a critical feature of the viral life cycle. Previous studies have shown an important role in transcription for the ubiquitin-proteasome pathway, but its role in HPV gene expression has not been addressed. We now show that HPV E2 requires an active proteasome for its optimal transcriptional activator function. This involves an interaction with the Mdm2 ubiquitin ligase, which together with E2 acts synergistically to activate the HPV type 16 promoter. We also show that HPV E2 recruits Mdm2 onto HPV promoter sequences, providing an explanation for this cooperative activity.
African Swine Fever Virus Blocks the Host Cell Antiviral Inflammatory Response through a Direct Inhibition of PKC-θ-Mediated p300 Transactivation
Authors: Granja Aitor G. , Sánchez Elena G. , Sabina Prado , Fresno Manuel , Revilla Yolanda
Published: November 2008

During a viral infection, reprogramming of the host cell gene expression pattern is required to establish an adequate antiviral response. The transcriptional coactivators p300 and CREB binding protein (CBP) play a central role in this regulation by promoting the assembly of transcription enhancer complexes to specific promoters of immune and proinflammatory genes. Here we show that the protein A238L encoded by African swine fever virus counteracts the host cell inflammatory response through the control of p300 transactivation during the viral infection. We demonstrate that A238L inhibits the expression of the inflammatory regulators cyclooxygenase-2 (COX-2) and tumor necrosis factor alpha (TNF-α) by preventing the recruitment of p300 to the enhanceosomes formed on their promoters. Furthermore, we report that A238L inhibits p300 activity during the viral infection and that its amino-terminal transactivation domain is essential in the A238L-mediated inhibition of the inflammatory response. Importantly, we found that the residue serine 384 of p300 is required for the viral protein to accomplish its inhibitory function and that ectopically expressed PKC-θ completely reverts this inhibition, thus indicating that this signaling pathway is disrupted by A238L during the viral infection. Furthermore, we show here that A238L does not affect PKC-θ enzymatic activity, but the molecular mechanism of this viral inhibition relies on the lack of interaction between PKC-θ and p300. These findings shed new light on how viruses alter the host cell antiviral gene expression pattern through the blockade of the p300 activity, which represents a new and sophisticated viral mechanism to evade the inflammatory and immune defense responses.
The C-Terminal Domains of Adenovirus Serotype 5 Protein IX Assemble into an Antiparallel Structure on the Facets of the Capsid
Authors: Fabry Céline M. S. , Rosa-Calatrava Manuel , Moriscot Christine , Ruigrok Rob W. H. , Boulanger Pierre , Schoehn Guy
Published: November 2008

Adenovirus serotype 5 protein IX (pIX) has two domains connected by a flexible linker. Three N-terminal domains form triskelions on the capsid facets that cement hexons together, and the C-terminal domains of four monomers form complexes toward the facet periphery. Here we present a cryoelectron microscopy structure of recombinant adenovirus with a peptide tag added to the C terminus of pIX. The structure, made up by several C termini of pIX, is longer at both ends than the wild-type protein, and Fabs directed against the tag bind to both ends of the oligomer, demonstrating that the pIX C termini associate in an antiparallel manner.
Structural Plasticity and Rapid Evolution in a Viral RNA Revealed by In Vivo Genetic Selection
Authors: Guo Rong , Lin Wai , Zhang Jiuchun , Simon Anne E. , Kushner David B.
Published: November 2008

Satellite RNAs usually lack substantial homology with their helper viruses. The 356-nucleotide satC of Turnip crinkle virus (TCV) is unusual in that its 3′-half shares high sequence similarity with the TCV 3′ end. Computer modeling, structure probing, and/or compensatory mutagenesis identified four hairpins and three pseudoknots in this TCV region that participate in replication and/or translation. Two hairpins and two pseudoknots have been confirmed as important for satC replication. One portion of the related 3′ end of satC that remains poorly characterized corresponds to juxtaposed TCV hairpins H4a and H4b and pseudoknot ψ
3
, which are required for the TCV-specific requirement of translation (V. A. Stupina et al., RNA 14:2379-2393, 2008). Replacement of satC H4a with randomized sequence and scoring for fitness in plants by in vivo genetic selection (SELEX) resulted in winning sequences that contain an H4a-like stem-loop, which can have additional upstream sequence composing a portion of the stem. SELEX of the combined H4a and H4b region in satC generated three distinct groups of winning sequences. One group models into two stem-loops similar to H4a and H4b of TCV. However, the selected sequences in the other two groups model into single hairpins. Evolution of these single-hairpin SELEX winners in plants resulted in satC that can accumulate to wild-type (wt) levels in protoplasts but remain less fit in planta when competed against wt satC. These data indicate that two highly distinct RNA conformations in the H4a and H4b region can mediate satC fitness in protoplasts.
Spatial heterogeneity of vegetation and environmental factors on talus slopes of the Niagara Escarpment
Authors: Cox Janet E. , Larson Douglas W.
Published: November 2008

Spatial heterogeneity of vegetation and environmental factors were studied on talus slopes of the Niagara Escarpment, southern Ontario, Canada. Random sampling of 197 taxa and 19 environmental variables along the length of the Escarpment permitted multivariate analysis of heterogeneity that occurred at both geographical and local scales. While previous work on these slopes had indicated that rockfall disturbance was the main organizing factor of vegetation, this variable was shown to be unimportant. Instead, we found geographical-scale control of vegetation heterogeneity related to one component of macroclimate and local-scale heterogeneity controlled by a complex of soil factors. The local-scale heterogeneity appeared to be too patchy, however, to be explained by normal soil development processes. We suggest that the talus vegetation develops in response to a positive feedback mechanism involving inputs of slowly decomposing wood from the neighbouring cliffs, followed by accelerated vegetation development on patches of fertile organic matter. Key words: talus vegetation, cliff, multivariate analysis, Niagara Escarpment, plant community, positive feedback, spatial heterogeneity.
Laboratory selection for copper tolerance in Scenedesmus acutus (Chlorophyceae)
Authors: Twiss M. R. , Welbourn P. M. , Schwärtzel E.
Published: November 2008

Through repeated subculturing of a Cu-sensitive population (X72) of the microalga Scenedesmus acutus f. alternans Hortobagyi (Chlorophyceae) in sublethal concentrations of copper (2.4 μM), a Cu-tolerant population (XCu) was derived. Tolerance to copper, measured as yield over 10 days in batch culture with 0.79 μM Cu, was constitutive. Adsorbed copper as a percentage of total copper was 77, 63, and 40% for a Cu-tolerant field isolate (B-4), XCu, and X72, respectively, during 16 h exposure to 10 μM Cu. These percentages were positively correlated with the level of copper tolerance displayed by the algal strains, i.e., B-4 > XCu > X72. Cells of XCu adsorbed twice as much copper per unit surface area in comparison with the parent strain (X72 = 13.1 amol∙μm−2; XCu = 26.0 amol∙μm−2). Exclusion of copper from the cell interior due to the high Cu-adsorptive capacity of the cell surface is suggested as the primary tolerance mechanism for the XCu strain. No metal cotolerance was demonstrated by XCu when assayed at 0.85 μM Co or Ni. Smaller cell size of the XCu but similar growth rate in comparison with the parent population X72 suggests that selection of a cell type from the original population may have occurred as a result of the copper challenge. Key words: algae, copper, metal tolerance, selection, toxicity.
Three new species of the genus Kengyilia (Poaceae: Triticeae) from West China and new combinations of related species
Authors: Yang Jun Liang , Yen Chi , Baum Bernard R.
Published: November 2008

This paper provides the nomenclatural protocols and illustrations for three new species of the genus Kengyilia from West China. The three species are Kengyilia tahelacana J. L. Yang, Yen et Baum, Kengyilia zhaosuensis J. L. Yang, Yen et Baum, and Kengyilia nana J. L. Yang, Yen et Baum. The results of karyotype analysis of the three taxa, each with 2n = 6x = 42, are also reported. In addition, three new combinations are made: Kengyilia batalinii (Krassn.) J. L. Yang, Yen et Baum, Kengyilia alaica (Drobov) J. L. Yang, Yen et Baum, and Kengyilia alatavica (Drobov) J. L. Yang, Yen et Baum. Distinguishing characters among these three related species are tabulated. Key words: new species, new combinations, Kengyilia, karyotypes, Triticeae, Poaceae.
Water relations and gas exchange in young coconut palm (Cocos nuciferaL.) as influenced by water deficit
Authors: Repellin Anne , Braconnier Serge , Laffray Daniel , Daniel Claude , Zuily-Fodil Yasmine
Published: November 2008

Drought is the main climatic limitation to coconut palm (Cocos nucifera L.) production. To identify early screening parameters for drought resistance, physiological responses to water deficit were investigated for the first time using containerized young plants grown outside. Three varieties were studied: 'West Coast Tall' (drought avoiding), 'Malayan Yellow Dwarf' (drought susceptible), and their progeny, the hybrid 'PB 121' (drought resistant). Leaf water status (relative water content, leaf water potential) and leaf gas exchange parameters (stomatal conductance to water vapor, net photosynthetic rate, and leaf internal CO2concentration) were measured throughout a drying cycle induced by withholding watering. On fully hydrated plants, the sensitivity of stomata to atmospheric water vapor deficit was also investigated. In the three varieties, stomatal conductance to water vapor declined before leaf water status parameters were affected. The existence of a root-to-shoot communication system was proposed. Net photosynthetic rate was highly dependent on stomatal aperture, but nonstomatal factors also participated in the reduction of CO2fixation. Since gas exchange rates were equally sensitive to drought in the three varieties, they could not be used as screening parameters for drought resistance. Under severe drought stress, both relative water content and leaf water potential differed significantly among populations. 'West Coast Tall' maintained a higher leaf water status than 'Malayan Yellow Dwarf'. Remarkably, the water status parameters of 'PB 121' were intermediate between those of the two parents. Similar ranking was obtained in experiments with excised leaflets. The high reproductibility of the results suggests that leaf water status parameters might be useful as early selection criteria for drought resistance in coconut palm. Key words: Cocos nucifera L., gas exchange, leaf water status parameters, water deficit, water relations.
Effect of soil moisture and fertilizer application on clonal growth and reproduction in a tristylous weed, Lythrum salicaria
Authors: Mal Tarun K. , Lovett-Doust Jon , Lovett-Doust Lesley
Published: November 2008

Clonal growth and reproduction in tristylous Lythrum salicaria L. were examined experimentally, using cloned genotypes of each of the three flower morphs, in field studies involving four moisture and three nutrient treatments. Clonal growth was measured in terms of diameter of clones, number of ramets per clone, and total length of ramets, and an index of reproduction was recorded as the total length of infructescence per clone. Neither clonal growth nor reproduction differed significantly among flower morphs, but both differed significantly as a consequence of both moisture and nutrient treatments. The pattern of seasonal growth indicates that ramet production was restricted mainly to the beginning of the season following vigorous vegetative growth. Although flowering began in June, it was restricted to plants in drier treatments in the water-gradient experiment. Characters intrinsic to tristyly (such as lengths of styles and stamens, and allocation of biomass to stamens and pistil) differed significantly among morphs. Soil moisture levels but not fertilizer treatments significantly affected the size of floral structures and biomass. Although absolute levels of biomass allocation to whole flowers and to attractive structures did not differ significantly among morphs, relative allocation to stamens increased progressively from long morph to mid-morph to short morph, with a corresponding decrease in relative mass of pistil. Although proportional allocation differed significantly among morphs, it was unaffected by moisture treatment, suggesting tight genetic control of herkogamy (spatial separation between anther and stigma). This should maintain the floral polymorphism in different ecological conditions. Key words: Lythrum salicaria, nutrient and water gradients, heterostyly, floral morphometry, floral allocation, clonal growth, sexual reproduction.
Lignin-degrading activity and ligninolytic enzymes of different white-rot fungi: effects of manganese and malonate
Authors: Vares Tamara , Hatakka Annele
Published: November 2008

Ten species of white-rot fungi, mainly belonging to the family Polyporaceae (Basidiomycotina), were studied in terms of their ability to degrade14C-ring labelled synthetic lignin and secrete ligninolytic enzymes in liquid cultures under varying growth conditions. Lignin mineralization by the fungi in an air atmosphere did not exceed 14% within 29 days. Different responses to the elevated Mn2+concentration and the addition of a manganese chelator (sodium malonate) were observed among various fungal species. This could be related with the utilization of either lignin peroxidase (LiP) or manganese peroxidase (MnP) for lignin depolymerization, i.e., some fungi apparently had an LiP-dominating ligninolytic system and others an MnP-dominating ligninolytic system. The LiP isoforms were purified from Trametes gibbosa and Trametes trogii. Isoelectric focusing of purified ligninolytic enzymes revealed the expression of numerous MnP isoforms in Trametes gibbosa, Trametes hirsuta, Trametes trogii, and Abortiporus biennis grown under a high (50-fold) Mn2+level (120 μM) with the addition of the chelator. In addition, two to three laccase isoforms were detected. Key words: white-rot fungi, lignin degradation, lignin peroxidase, manganese peroxidase, manganese, malonate.
Small-scale distribution and salinity response of Juniperus virginiana on an Atlantic Coast barrier island
Authors: Martin David W. , Young Donald R.
Published: November 2008

A field and laboratory study examined the hypothesis that the small-scale distribution pattern of Juniperus virginiana on barrier islands is related to salinity patterns and plant responses to salinity. Temporal (May – October) and spatial variability in ground water availability, ground water salinity, and total soil chlorides were quantified across a Virginia barrier island. Groundwater depth and salinity increased throughout the summer; microtopographic position and location on the island also affected soil salinities. Highest salinities occurred near the ocean side beach and bay side marsh, as well as in low lying swales that flood during extreme high tides or storms. Median rooting zone chloride level for J. virginiana was 54 μg/g. In contrast, laboratory germination and growth studies indicated that J. virginiana was significantly affected only at high salinity levels (1000 and 1400 μg/g), suggesting that salinity is not the only factor regulating small-scale distribution patterns. The broad tolerance to salinity may account for the abundance of J. virginiana in coastal environments. Key words: barrier island, eastern red cedar, Juniperus virginiana, salinity response, water relations.