bluuebunny/crossref_metadata_2025 huggingface dataset:
A dynamic conceptual model of care planning
Authors: Elf Marie , Poutilova Maria , Öhrn Kerstin
Published: November 2007

This article presents a conceptual model of the care planning process developed to identify the hypothetical links between structural, process and outcome factors important to the quality of the process. Based on existing literature, it was hypothesized that a thorough assessment of patients’ health needs is an important prerequisite when making a rigorous diagnosis and preparing plans for various care interventions. Other important variables that are assumed to influence the quality of the process are the care culture and professional knowledge. The conceptual model was developed as a system dynamics causal loop diagram as a first essential step towards a computed model. System dynamics offers the potential to describe processes in a nonlinear, dynamic way and is suitable for exploring, comprehending, learning and communicating complex ideas about care processes.
Patients’ and nurses’ experiences of the caring relationship in hospital: an aware striving for trust
Authors: Berg Linda , Danielson Ella
Published: November 2007

The phenomenon, caring relationship, has been widely studied in earlier research. Nevertheless, empirical studies in hospital, concerning patients and nurses experiences of the actual phenomenon caring relationship are rare. The aim was to illuminate patients with long‐term illness and nurses’ experiences of the caring relationship. The data were collected from 13 interviews, seven patients and six nurses, which were then analysed using an interpretive phenomenological method. This study shows patients’ and nurses’ view of the phenomenon. The findings concerning patients’ view were identified in themes –‘Maintaining dignity’ with subthemes: using one's own competence and being cared for by the team as well as ‘A feeling of vulnerability’ with subthemes: being cared for in a strained situation and being exposed, inquiring personal caring relationship. The findings concerning nurses’ view were identified in the following themes: ‘A purposeful striving’ with subthemes: using one's own competence and being aware of limitations as well as ‘An arduous compassion’ with subthemes: giving care in a strained situation and being aware of what is needed. These findings show that patients and nurses were aware in their striving for trust through forming a caring relationship. Their striving was not enough to result in trust. The findings in this study are understood as patients need a personal caring relationship which enables the possibility of trust.
Patient attitudes, behaviours, and other factors considered by doctors when estimating cancer patients’ anxiety and desire for information
Authors: Fröjd Camilla , Lampic Claudia , Larsson Gunnel , Birgegård Gunnar , Essen Louise von
Published: November 2007

The aim was to describe the patient attitudes, behaviours, and other factors, considered by doctors when estimating cancer patients’ worry about how the disease may develop and the desire for information about the disease and its treatment. Data was gathered through semi‐structured interviews with 19 doctors regarding 29 patients within endocrine oncology and haematology care, and the data were analysed by content analysis. The doctors considered the patients’ verbal expressions, verbal behaviours, questions, body language, and facial expressions together with their own professional knowledge and experience, when estimating the patients’ worry and desire for information. The doctors also considered contextual factors, patients’ demographical factors, and medical situation when estimating the patients’ worry, and also when estimating the patients’ desire for information. The findings illustrate that estimating patients’ worry and desire for information is a multifaceted and complex task, and that doctors consider not only the patients’ verbal and nonverbal cues, but also factors, such as their own professional knowledge and experience, contextual factors, and patients’ demographical variables. The findings should be communicated to doctors who meet cancer patients in medical consultations in order to illuminate the complexity of the medical consultation. The awareness of potentially important patient cues and other factors may aid doctors in their efforts to gain insight about their patients’ emotions and informational needs.
Bilby distribution and fire: a test of alternative models of habitat suitability in the Tanami Desert, Australia
Authors: Southgate Richard , Paltridge Rachel , Masters Pip , Carthew Susan
Published: November 2007

The distribution of the bilby Macrotis lagotis was assessed in the Tanami Desert using stratified random plots, repetitively sampled transects, aerial survey transects, and ground truth plots. Compared to a previous assessment of distribution, the extent of occurrence has changed little in the last 20 yr. However, the area of occupancy is small relative to the extent of occurrence and <25% of the current geographic range has bilby sign <20 km apart. Generalised linear modelling was used to determine the strength of association between bilby occurrence and habitat variables and identify refugia characteristics. Four competing candidate models were examined to determine whether bilby occurrence associated significantly with productive substrates and introduced herbivores, the distribution of key predator species, the pattern of fire, and climatic gradients including rainfall and temperature. For the entire study area, bilby presence associated most strongly with variables of mean annual rainfall, substrate type and the probability of dingo occurrence. Proximity to recently burnt habitat formed a significant predictor of bilby occurrence in a model derived for a reduced part of the study area where most sign was found. The work suggested that the current frameworks underpinning understanding of biotic distributions in arid Australia are deficient, and that climatic gradients, lateritic and rocky systems, and predators need to be incorporated into our thinking in the future. The extent of occurrence based on outlier records from opportunistic reports provided a misleading indication of the true status of the bilby.
End-to-End Stacking and Liquid Crystal Condensation of 6– to 20–Base Pair DNA Duplexes
Authors: Nakata Michi , Zanchetta Giuliano , Chapman Brandon D. , Jones Christopher D. , Cross Julie O. , Pindak Ronald , Bellini Tommaso , Clark Noel A.
Published: November 2007

Short complementary B-form DNA oligomers, 6 to 20 base pairs in length, are found to exhibit nematic and columnar liquid crystal phases, even though such duplexes lack the shape anisotropy required for liquid crystal ordering. Structural study shows that these phases are produced by the end-to-end adhesion and consequent stacking of the duplex oligomers into polydisperse anisotropic rod-shaped aggregates, which can order into liquid crystals. Upon cooling mixed solutions of short DNA oligomers, in which only a small fraction of the DNA present is complementary, the duplex-forming oligomers phase-separate into liquid crystal droplets, leaving the unpaired single strands in isotropic solution. In a chemical environment where oligomer ligation is possible, such ordering and condensation would provide an autocatalytic link whereby complementarity promotes the extended polymerization of complementary oligomers.
Response to Comment on "Roadless Space of the Conterminous United States"
Authors: Watts Raymond D. , Compton Roger W. , McCammon John H. , Rich Carl L. , Wright Stewart M. , Owens Tom , Ouren Douglas S.
Published: November 2007

Girvetz
et al
. criticize our work and the value of the roadless volume (RV) metric, basing their arguments on the artificial imposition of wildlife habitat connectivity as the context. We counter that in our intended contexts, both practical and geographic theoretical considerations make RV an appropriate measure of the space between roads.
Adventurer in Genome Science
Authors: Hilgartner Stephen
Published: November 2007

A Life Decoded
. My Genome: My Life.
By J. Craig Venter
. Viking, New York, 2007. 416 pp. $25.95, C$31. ISBN 9780670063581. Allen Lane, London. £25. ISBN 9780713997248.

The author recounts the course of his life to date and his quests in genome sequencing and synthetic life.
Manners, Good and Bad
Authors: Brenner Sydney
Published: November 2007

Avoid Boring People
. Lessons from a Life in Science / And Other Lessons from a Life in Science.
By James D. Watson
. Knopf, New York, 2007. 365 pp. $26.95, C$34.95. ISBN 9780375412844. Oxford University Press, Oxford. £14.99. ISBN 9780192802736.

Rather than providing a third installment of his life story, the author recounts his adventures from his birth through his leaving his Harvard position for Cold Spring Harbor and highlights lessons he learned along the way.
Use of Whole-Blood Samples in In-House Bulk and Single-Cell Antigen-Specific Gamma Interferon Assays for Surveillance of
Mycobacterium tuberculosis
Infections
Authors: Palazzo Raffaella , Spensieri Fabiana , Massari Marco , Fedele Giorgio , Frasca Loredana , Carrara Stefania , Goletti Delia , Ausiello Clara M.
Published: November 2007

Tests based on the gamma interferon (IFN-γ) assay (IGA) are used as adjunctive tools for the diagnosis of
Mycobacterium tuberculosis
infection. Here we compared in-house and commercial whole-blood IGAs to identify a suitable assay for the surveillance of tuberculosis in population studies. The IGAs were selected on the basis of the ease with which they are performed and because they require a small amount of a biological sample and do not require cell purification. Since a “gold standard” for latently
M. tuberculosis
-infected individuals is not available, the sensitivities and the specificities of the IGAs were determined with samples from patients with clinically diagnosed active tuberculosis and in
Mycobacterium bovis
BCG-unvaccinated healthy controls. The in-house tests consisted of a bulk assay based on diluted whole blood and a single-cell assay based on IFN-γ intracellular staining. The commercial assays used were the QuantiFERON-TB-Gold (Q-TB) and the Q-TB in-tube tests. When the purified protein derivative was used as the antigen, in-house whole-blood intracellular staining was found to be highly discriminatory between active tuberculosis patients and BCG-vaccinated healthy controls, whereas the other IGAs did not discriminate between the two categories of patients. When
M. tuberculosis
-specific antigens were used, a very strong agreement between the results of the Q-TB in-tube assay and the clinical diagnosis was observed, while the Q-TB assay, performed according to the manufacturer's instructions, showed a significantly lower performance. Intriguingly, when the test was performed with RD1 proteins instead of peptides, its sensitivity was significantly increased. The in-house assay with diluted whole blood showed an elevated sensitivity and an elevated specificity, and the results agreed with the clinical diagnosis. Considering that the in-house assay uses 1/20 of the sample compared with the amount of sample used in the commercial IGA, it appears to be particularly promising for use in pediatric studies. Overall, the different assays showed different performance characteristics that need to be considered for surveillance of tuberculosis in population studies.
Well-Characterized Monoclonal Antibodies against Cell Wall Antigen of
Aspergillus
Species Improve Immunoassay Specificity and Sensitivity
Authors: Hao Wei , Pan Yu-Xian , Ding Yan-Qing , Xiao Sha , Yin Kai , Wang Ya-Di , Qiu Li-Wen , Zhang Qing-Lin , Woo Patrick C. Y. , Lau Susanna K. P. , Yuen Kwok-Yung , Che Xiao-Yan
Published: November 2007

The diagnosis of invasive aspergillosis (IA) based on the detection of
Aspergillus
galactomannan (GM) is complicated by the presence of cross-reactive GM epitopes in patient specimens. We have developed a novel and specific
Aspergillus
antigen-capture enzyme-linked immunosorbent assay (ELISA) by the selection of two well-characterized monoclonal antibodies from 17 candidate antibodies. The epitopes recognized by the monoclonal antibodies were present on the cell walls of the hyphae and the conidia of
Aspergillus
species, which were circulating or excreted as immunodominant antigens during the acute phase of IA established in the animal models. The detection of experimental
Aspergillus
-mediated antigenemia was suitably sensitive, and the sensitivity was comparable to that of a commercial GM detection ELISA kit (the Platelia
Aspergillus
assay). Moreover, the specificity of this assay was 100% when it was used to test 382 serum specimens and 120 urine specimens from healthy individuals. Cross-reactivity with other common opportunistic fungi, such as
Penicillium
and
Candida
species, and with purified GM protein derived from
Aspergillus
was not evident. Therefore, the chemical nature of the epitopes captured in this assay is most likely not associated with the GM structure, indicating that this newly developed
Aspergillus
antigen-capture ELISA is a promising tool for the diagnosis of IA without the risk of the false-positive results that are problematic with current GM antigen assays.
Rapid and Highly Sensitive Coxsackievirus A Indirect Immunofluorescence Assay Typing Kit for Enterovirus Serotyping
Authors: Lin Tsuey-Li , Li Yi-Syue , Huang Chiao-Wei , Hsu Chiu-Chu , Wu Ho-Sheng , Tseng Tsan-Chang , Yang Chen-Fu
Published: November 2007

We describe the development and evaluation of an indirect immunofluorescence assay (IFA) kit for rapid and sensitive detection of coxsackievirus A2, -4, -5, -6, and -10. This IFA kit was determined to have 95.9 to 100% sensitivity and 95.8 to 97.2% specificity. It also proved to be beneficial in reducing the number of enteroviruses that are untypeable in the clinical virology laboratory.
Hidden VIM-1 Metallo-β-Lactamase Phenotypes among
Acinetobacter baumannii
Clinical Isolates
Authors: Ikonomidis Alexandros , Ntokou Eleni , Maniatis Antonios N. , Tsakris Athanassios , Pournaras Spyros
Published: November 2007

A total of 87
Acinetobacter baumannii
nonrepetitive consecutive clinical isolates were tested for the presence of metallo-β-lactamases (MBLs). Results of phenotypic assays (MBL Etest, imipenem/imipenem-EDTA combined-disk test, and imipenem/EDTA double-disk synergy test) were negative in all cases, but molecular testing revealed the presence of two
bla
VIM-1
-carrying isolates. One isolate had
bla
VIM-1
preceded by a weak P1 promoter, and both had inactivated P2 promoters and reduced
bla
VIM-1
expression, partially justifying the results revealing hidden MBL phenotypes.
Elucidating Global Epidemiology of
Burkholderia multivorans
in Cases of Cystic Fibrosis by Multilocus Sequence Typing
Authors: Baldwin Adam , Mahenthiralingam Eshwar , Drevinek Pavel , Pope Chris , Waine David J. , Henry Deborah A. , Speert David P. , Carter Phil , Vandamme Peter , LiPuma John J. , Dowson Chris G.
Published: November 2007

Burkholderia multivorans
is a prominent
B. cepacia
complex (BCC) species causing infection in people with cystic fibrosis. Despite infection control measures being introduced to reduce the spread of BCC there is a continued emergence of infections by
B. multivorans
. Our objective was to analyze a global collection of
B. multivorans
isolates, comparing those from environmental and clinical sources with those from reported outbreaks. Multilocus sequence typing (MLST) was performed on 107
B. multivorans
isolates to provide a detailed analysis of the global population biology of this species. MLST resolved 64
B. multivorans
sequence types. Twelve of these were globally distributed and associated with human infection; two of these (ST-21 and ST-375) were also composed of environmental isolates. These global lineages included strains previously linked to large outbreaks (e.g., French epidemic clone ST-16). Though few environmental isolates of
B. multivorans
were available for analysis, of six strains identified, three were identical to strains recovered from cystic fibrosis (CF) infection. Although the ability of
B. multivorans
to cause CF outbreaks is known, our report here concerning the existence of globally distributed
B. multivorans
CF strains is a new observation for this emerging
B. cepacia
complex pathogen and suggests that certain strain types may be better adapted to human infection than others. Common transmission-associated risk factors were not obviously linked to the globally distributed strains; however, the overlap in strains recovered from water environments, industrial products, and human infection suggests that environmental sources may be an important reservoir for infection with
B. multivorans
.
Identification of Residues Required for RNA Replication in Domains II and III of the Hepatitis C Virus NS5A Protein
Authors: Tellinghuisen Timothy L. , Foss Katie L. , Treadaway Jason C. , Rice Charles M.
Published: November 2007

The NS5A protein of hepatitis C virus (HCV) plays an important but undefined role in viral RNA replication. NS5A has been proposed to be a three-domain protein, and the crystal structure of the well-conserved amino-terminal domain I has been determined. The remaining two domains of NS5A, designated domains II and III, and their corresponding interdomain regions are poorly understood. We have conducted a detailed mutagenesis analysis of NS5A domains II and III using the genotype 1b HCV replicon system. The majority of the mutants containing 15 small (8- to 15-amino-acid) deletions analyzed were capable of efficient RNA replication. Only five deletion mutations yielded lethal phenotypes, and these were colinear, spanning a 56-amino-acid region within domain II. This region was further analyzed by combining triple and single alanine scanning mutagenesis to identify individual residues required for RNA replication. Based upon this analysis, 23 amino acids were identified that were found to be essential. In addition, two residues were identified that yielded a small colony phenotype while possessing only a moderate defect in RNA replication. These results indicate that the entire domain III region and large portions of domain II of the NS5A protein are not required for the function of NS5A in HCV RNA replication.
Early Divergence in Lymphoid Tissue Apoptosis between Pathogenic and Nonpathogenic Simian Immunodeficiency Virus Infections of Nonhuman Primates
Authors: Cumont M.-C. , Diop O. , Vaslin B. , Elbim C. , Viollet L. , Monceaux V. , Lay S. , Silvestri G. , Le Grand R. , Müller-Trutwin M. , Hurtrel B. , Estaquier J.
Published: November 2007

The events that contribute to the progression to AIDS during the acute phase of a primate lentiviral infection are still poorly understood. In this study, we used pathogenic and nonpathogenic simian models of simian immunodeficiency virus (SIV) infection of rhesus macaques (RMs) and African green monkeys (AGMs), respectively, to investigate the relationship between apoptosis in lymph nodes and the extent of viral replication, immune activation, and disease outcome. Here, we show that, in SIVmac251-infected RMs, a marked increased in lymphocyte apoptosis is evident during primary infection at the level of lymph nodes. Interestingly, the levels of apoptosis correlated with the extent of viral replication and the rate of disease progression to AIDS, with higher apoptosis in RMs of Indian genetic background than in those of Chinese origin. In stark contrast, no changes in the levels of lymphocyte apoptosis were observed during primary infection in the nonpathogenic model of SIVagm-sab infection of AGMs, despite similarly high rates of viral replication. A further and early divergence between SIV-infected RMs and AGMs was observed in terms of the dynamics of T- and B-cell proliferation in lymph nodes, with RMs showing significantly higher levels of cycling cells (Ki67+) in the T-cell zones in association with relatively low levels of Ki67+in the B-cell zones, whereas AGMs displayed a low frequency of Ki67+in the T-cell area but a high proportion of Ki67+cells in the B-cell area. As such, this study suggests that species-specific host factors determine an early immune response to SIV that predominantly involves either cellular or humoral immunity in RMs and AGMs, respectively. Taken together, these data are consistent with the hypotheses that (i) high levels of T-cell activation and lymphocyte apoptosis are key pathogenic factors during pathogenic SIV infection of RMs and (ii) low T-cell activation and apoptosis are determinants of the AIDS resistance of SIVagm-infected AGMs, despite high levels of SIVagm replication.
The UL14 Tegument Protein of Herpes Simplex Virus Type 1 Is Required for Efficient Nuclear Transport of the Alpha Transinducing Factor VP16 and Viral Capsids
Authors: Yamauchi Yohei , Kiriyama Kazuya , Kubota Naomi , Kimura Hiroshi , Usukura Jiro , Nishiyama Yukihiro
Published: November 2007

The protein encoded by the UL14 gene of herpes simplex virus type 1 (HSV-1) and HSV-2 is expressed late in infection and is a minor component of the virion tegument. An UL14-deficient HSV-1 mutant (UL14D) forms small plaques and exhibits an extended growth cycle at low multiplicities of infection (MOI) compared to wild-type virus. Although UL14 is likely to be involved in the process of viral maturation and egress, its precise role in viral replication is still enigmatic. In this study, we found that immediate-early viral mRNA expression was decreased in UL14D-infected cells. Transient coexpression of UL14 and VP16 in the absence of infection stimulated the nuclear accumulation of both proteins. We intended to visualize the fate of VP16 released from the infected virion and constructed UL14-null (14D-VP16G) and rescued (14R-VP16G) viruses that expressed a VP16-green fluorescent protein (GFP) fusion protein. Synchronous high-multiplicity infection of the viruses was performed at 4°C in the absence of de novo protein synthesis. We found that the presence of UL14 in the virion had an enhancing effect on the nuclear accumulation of VP16-GFP. The lack of UL14 did not significantly alter virus internalization but affected incoming capsid transport to the nuclear pore. These observations suggested that UL14 (i) enhanced VP16 nuclear localization at the immediately early phase, thus indirectly regulating the expression of immediate-early genes, and (ii) was associated with efficient nuclear targeting of capsids. The tegument protein UL14 could be part of the machinery that regulates HSV-1 replication.
Inhibition of Endosome-Lysosome System Acidification Enhances Porcine Circovirus 2 Infection of Porcine Epithelial Cells
Authors: Misinzo Gerald , Delputte Peter L. , Nauwynck Hans J.
Published: November 2007

Recently, Misinzo et al. (G. Misinzo, P. Meerts, M. Bublot, J. Mast, H. M. Weingartl, and H. J. Nauwynck, J. Gen. Virol.
86
:2057-2068, 2005) reported that inhibiting endosome-lysosome system acidification reduced porcine circovirus 2 (PCV2) infection of monocytic 3D4/31 cells. The present study examined the effect of inhibiting endosome-lysosome system acidification in epithelial cells, since epithelial cells support PCV2 infection in vivo and are used in culturing PCV2 in vitro. Ammonium chloride (NH
4
Cl), chloroquine diphosphate (CQ), and monensin were used to inhibit endosome-lysosome system acidification. NH
4
Cl, CQ, or monensin increased PCV2 (Stoon-1010) infection by 726% ± 110%, 1,212% ± 34%, and 1,100% ± 179%, respectively, in porcine kidney (PK-15) cells; by 128% ± 7%, 158% ± 3%, and 142% ± 11% in swine kidney cells; by 160% ± 28%, 446% ± 50%, and 162% ± 56% in swine testicle (ST) cells; and by 313% ± 25%, 611% ± 86%, and 352% ± 44% in primary kidney epithelial cells. Similarly, increased PCV2 infection was observed with six other PCV2 strains in PK-15 cells treated with endosome-lysosome system acidification inhibitors. The mechanism behind increased PCV2 infection was further investigated in PK-15 cells using CQ. PCV2 infection of PK-15 cells was increased only when CQ was added early during PCV2 infection. CQ did not affect PCV2 virus-like particle (VLP) attachment to PK-15 cells but increased the disassembly of internalized PCV2 VLPs. In untreated PK-15 cells, internalized PCV2 VLPs localized within the endosome-lysosome system. PCV2 infection of untreated 3D4/31 and PK-15 cells and CQ-treated PK-15 cells was blocked by a serine protease inhibitor [4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride] but not by aspartyl protease (pepstatin A), cysteine protease (E-64), and metalloprotease (phosphoramidon) inhibitors. These results suggest that serine protease-mediated PCV2 disassembly is enhanced in porcine epithelial cells but inhibited in monocytic cells after inhibition of endosome-lysosome system acidification.
Species-Specific Restriction of Apobec3-Mediated Hypermutation
Authors: Browne Edward P. , Littman Dan R.
Published: November 2007

Apobec proteins are a family of cellular cytidine deaminases, among which several members have been shown to have potent antiviral properties. This antiviral activity is associated with the ability to cause hypermutation of retroviral cDNA. However, recent research has indicated that Apobec proteins are also able to inhibit retroviruses by other mechanisms that are independent of their deaminase activity. We have compared the antiviral activities of human and murine Apobec3 (A3) proteins, and we have found that, consistent with previous reports, human immunodeficiency virus (HIV) is able to resist human A3G but is sensitive to murine A3, whereas murine leukemia virus (MLV) is relatively resistant to murine A3 (mA3) but sensitive to human A3G. In contrast to previous studies, we observed that mA3 is packaged efficiently into MLV particles. The C-terminal cytidine deaminase domain (CDD2) is required for packaging of mA3 into MLV particles, and packaging did not depend on the MLV viral RNA. However, mA3 packed into MLV particles failed to cause hypermutation of viral DNA, indicating that its deaminase activity is blocked or inhibited. hA3G also caused significantly less hypermutation of MLV than of HIV DNA. Both mA3 and the splice variant mA3Δ5 exhibited some residual antiviral activity against MLV and caused a reduction in the ability of MLV particles to generate reverse transcription products. These results suggest that MLV has evolved specific mechanisms to block the ability of Apobec proteins to mediate deaminase-dependent hypermutation.
Replication-Coupled Packaging Mechanism in Positive-Strand RNA Viruses: Synchronized Coexpression of Functional Multigenome RNA Components of an Animal and a Plant Virus in
Nicotiana benthamiana
Cells by Agroinfiltration
Authors: Annamalai Padmanaban , Rofail Fady , DeMason Darleen A. , Rao A. L. N.
Published: November 2007

Flock house virus (FHV), a bipartite RNA virus of insects and a member of the
Nodaviridae
family, shares viral replication features with the tripartite brome mosaic virus (BMV), an RNA virus that infects plants and is a member of the
Bromoviridae
family. In BMV and FHV, genome packaging is coupled to replication, a widely conserved mechanism among positive-strand RNA viruses of diverse origin. To unravel the events that modulate the mechanism of replication-coupled packaging, in this study, we have extended the transfer DNA (T-DNA)-based agroinfiltration system to express functional genome components of FHV in plant cells (
Nicotiana benthamiana
). Replication, intracellular membrane localization, and packaging characteristics in agroinfiltrated plant cells revealed that T-DNA plasmids of FHV were biologically active and faithfully mimicked complete replication and packaging behavior similar to that observed for insect cells. Synchronized coexpression of wild-type BMV and FHV genome components in plant cells resulted in the assembly of virions packaging the respective viral progeny RNA. To further elucidate the link between replication and packaging, coat protein (CP) open reading frames were precisely exchanged between BMV RNA 3 (B3) and FHV RNA 2 (F2), creating chimeric RNAs expressing heterologous CP genes (B3/FCP and F2/BCP). Coinfiltration of each chimera with its corresponding genome counterpart to provide viral replicase (B1+B2+B3/FCP and F1+F2/BCP) resulted in the expected progeny profiles, but virions exhibited a nonspecific packaging phenotype. Complementation with homologous replicase (with respect to CP) failed to enhance packaging specificity. Taken together, we propose that the transcription of CP mRNA from homologous replication and its translation must be synchronized to confer packaging specificity.
A Diacidic Motif in Human Immunodeficiency Virus Type 1 Nef Is a Novel Determinant of Binding to AP-2
Authors: Lindwasser O. Wolf , Smith William J. , Chaudhuri Rittik , Yang Peter , Hurley James H. , Bonifacino Juan S.
Published: November 2007

A key function of the Nef protein of immunodeficiency viruses is the downregulation of the T-cell and macrophage coreceptor, CD4, from the surfaces of infected cells. CD4 downregulation depends on a conserved (D/E)XXXL(L/I)-type dileucine motif in the C-terminal, flexible loop of Nef, which mediates binding to the clathrin adaptor complexes AP-1, AP-2, and AP-3. We now report the identification of a consensus (D/E)D motif within this loop as a second, conserved determinant of interaction of Nef with AP-2, though not with AP-1 and AP-3. Mutations in this diacidic motif abrogate both AP-2 binding and CD4 downregulation. We also show that a dileucine motif from tyrosinase, both in its native context and in the context of Nef, can bind to AP-2 independently of a diacidic motif. These results thus identify a novel type of AP-2 interaction determinant, support the notion that AP-2 is the key clathrin adaptor for the downregulation of CD4 by Nef, and reveal a previously unrecognized diversity among dileucine sorting signals.
Oxidation of phosphohydroxypyruvate and hydroxypyruvate: physiological implications in plants
Authors: Daley L. S. , Vines H. Max , Bidwell R. G. S.
Published: November 2007

Rates of nonenzymic oxygen consumption by phosphohydroxypyruvate, hydroxypyruvate, and phosphoglyceric acid were compared. Relative rates of 1:20:0 were found at physiological pH. The results support the occurrence of phosphohydroxypyruvate metabolism that may contribute to photorespiration, and the presence of a serine biosynthetic pathway via phosphoserine in plants.
Leciographa gallicola n.sp., a putative parasite on aspen galls
Authors: Funk A.
Published: November 2007

Leciographa gallicola n.sp. (Patellariaceae) is described from galls of aspen (Populus tremuloides Michx.) in western Canada.
Sopagraha sibika, a new Hyphomycete from leaf litter from India
Authors: Subramanian C. V. , Sudha K.
Published: November 2007

An undescribed Hyphomycete occurring on leaf litter of Glycosmis cochinchinensis Pierre, collected at Tambaram, near Madras, India, is described and assigned to a new genus Sopagraha as a new species S. sibika.
Buried viable propagules as a factor in postfire regeneration in northern Saskatchewan
Authors: Archibold O. W.
Published: November 2007

Soils collected from seven sample plots in a burned mixed-wood area in northern Saskatchewan were held at optimum laboratory conditions to determine the number of viable seeds and latent underground buds. A total of 270 plants developed, representing a rate of emergence of 426 plants/m2 of which 372 plants (87%) originated from seed and 54 (13%) came from remnant roots or rhizomes. In addition, 19 birch seeds were extracted from the soil following the germination tests giving a total count of 456 propagules/m2. Tree species accounted for 42.9% of this total.
Development of the female flower and gynecandrous partial inflorescence of Myrica californica
Authors: Macdonald Alastair D.
Published: November 2007

Organogenesis of the female flower and gynecandrous partial inflorescence is described. Approximately 25 first-order inflorescence bracts are formed in an acropetal sequence. A second-order inflorescence axis, the partial inflorescence, develops in the axil of each bract. Third-, fourth-, and fifth-order axes arise in the axils of second-, third-, and fourth-order bracts. A gynoecium terminates a second-order axis and sometimes a distal third-order axis. A gynoecium consists of two stigmas and one basal, unitegmic, orthotropous ovule. The wall enclosing the ovule, the circumlocular wall, is comprised distally of gynoecial tissue and proximally of tissue of the inflorescence axis and its appendages. The latter portion of the wall is formed by zonal growth. Androecial members, formed proximal to the gynoecium on the partial inflorescence, are carried onto the circumlocular wall by zonal growth. A stamen may develop from the last-formed primordium before gynoecial inception or from a potentially stigmatic primordium. The papillae of the flower and fruit arise as emergences and from potentially bracteate, axial, and staminate primorida during the development of the circumlocular wall. The term circumlocular wall is used in a neutral sense to describe this unique structure. Since the gynoecium is composed of gynoecial appendages and inflorescence axis and appendages, a functional definition of gynoecium must be expanded to include any tissue, including an inflorescence, that surrounds the ovule(s) and forms the fruit(s).
New combinations in Hypericum, Triadenum, and Gentianopsis
Authors: Gillett John M.
Published: November 2007

For consistency in use of subspecific rank in forthcoming publications, the following combinations are made: Hypericum scoitleri Hook. ssp. nortoniae (M. E. Jones) J. M. Gillett, H. mutilum L. ssp. boreale (Britton) J. M. Gillett, Triadenum virginicum (L.) Raf. ssp. fraseri (Spach) J. M. Gillett, and Gentianopsis detansa (Rottb.) Ma ssp. yukonensis (J. M. Gillett) J. M. Gillett.
Biochemical contributions to the taxonomic status of the Endogonaceae
Authors: Weijman A. C. M. , Meuzelaar H. L. C.
Published: November 2007

The Endogonaceae are generally considered as zygomycete representatives, although zygospores have only been observed in the type genus Endogone. Consequently, the oomycetous or chytridiomycetous nature of some fungi classified in the Endogonaceae cannot be excluded. The presence or absence of chitin in cell walls can indicate the oomycetous or zygomycetous relationship. The occurrence of glucosamine was investigated by gas–liquid chromatographic analysis of intact cell hydrolyzates, a process requiring small quantities of material. The cells were also characterized by Curie-point pyrolysis mass spectrometry. These two techniques were applied to lyophilized spores or sporocarps of Endogone, Glomus, Glaziella, and Gigaspora. Mucor mucedo, Allomyces arbuscula, Pythium spinosum, and Saprolegnia ferax were included for comparison.In all endogonaceous isolates tested, a strong predominance of chitin was indicated, supporting their classification within the Zygomycetes.The phylogenetic significance of chitin and cellulose distribution in fungal cell walls is discussed.
Photosynthesis in black and red spruce and their hybrid derivatives: ecological isolation and hybrid adaptive inferiority
Authors: Manley S. A. M. , Ledig F. Thomas
Published: November 2007

Photosynthetic responses of black and red spruce were used to define parameters of their fundamental niches. Grown at warm temperature, black spruce had highest rates of CO2 uptake at high light intensities, fitting it for a pioneering role, while red spruce had the lowest light compensation point, fitting it for a late successional role. Black and red spruce responded in different ways to low temperature acclimation. Low temperature, low light (12 °C, 100 ft-c (1 ft-c = 10.764lx)) acclimation stimulated CO2 uptake in black spruce under all conditions while it depressed CO2 uptake in red spruce relative to rates following high temperature (26 °C) acclimation. Niches defined by photosynthetic responses corresponded to observed habitats in the area of sympatry of black and red spruce and demonstrated the existence of ecological isolation, a premating restriction to hybridization.Hybrids, backcrosses, and recurrent backcrosses of black and red spruce had lower rates of CO2 uptake than one or the other species in all light and temperature environments tested. In most cases, the hybrid had lower rates than both species. Growth depends on photosynthesis and is one component of fitness. Therefore, negative heterosis in hybrids and hybrid derivatives represents another mechanism of reproductive isolation, the postulating barrier of hybrid adaptive inferiority. Selection against hybrids should be density dependent, explaining both their widespread occurrence in habitats opened by fire or logging and their paucity in closed stands.
Seasonal development of Dutch elm disease on white elms in central Ontario, Canada. I. Following wound inoculation
Authors: Takai S. , Kondo E. S.
Published: November 2007

Field inoculation experiments were carried out to determine the pattern of Ceratocystis ulmi infection of white elm (Ulmus americana). From April 7 to October 27, 1971, four methods of artificial inoculation were used to infect healthy, naturally occurring elm saplings approximately 56 km north of Sault Ste. Marie, Ontario. External and internal symptoms of Dutch elm disease, internal spread of C. ulmi, and external damage by the disease were correlated with inoculation methods and seasonal morphological development of elm.The results suggested that the most susceptible period for successful artificial infection of white elm in 1971 was early June to late July. The beginning of the most susceptible period corresponded with the initiation of leaf expansion and large size of springwood vessels in the outer rings. It coincided with a change in accumulated degree days above 5.6 °C from minus to plus. A decline in susceptibility was found after August 12 when leaves were fully matured and 1971 buds had developed. Inoculations before June 3 resulted in the expression of wilting symptoms, always about June 24. This indicates that the disease development is highly dependent on host morphological and physiological conditions.The slit method of inoculation most closely simulated natural beetle infection. The modified Hagborg method of inoculation gave results similar to those of the slit method but required more effort and time in practice. The drill and chisel methods appeared too severe and resulted in the death of all trees inoculated from April 7 to August 12.
Evolution du contenu en DNA nucléaire dans les gamétophytes mâles du Datura innoxia au cours de la période favorable à l'androgenèse
Authors: Sangwan-Norreel Brigitte S.
Published: November 2007

The nuclear DNA content was estimated by densitometry for six stages during the maturation of male gamétophytes of Datura innoxia Mill. Changes in nucleus size and structure (distribution of chromatin) were analysed simultaneously. The following were found. (a) After the tetrad stage, DNA synthesis preceding the first haploid mitosis took place progressively and slowly. Once this division was terminated, the pollen nuclei had the same DNA content (1C). When the period favoring embryogenesis was completed, the DNA content of the reproductive nuclei approached 2C while there was a tendency for the vegetative nuclei to undergo endomitosis. (b) A direct correlation between DNA content and size of pollen nuclei was only noted for the stages having identical nuclear structures. (c) The stage during which the pollen grain had the greatest embryological potential was a period of complete change in the DNA content (change from postsynthetic to presynthetic). (d) The fusion of the 2C reproductive nucleus with the 4C vegetative nucleus could lead to the formation, after a normal mitosis, of a 3C pollen nucleus; that would explain the formation of androgenic triploid seedlings found in Datura innoxia. [Translated by the Journal]
Early stages in colony development in the genus Meliola
Authors: Goos R. D. , Palm Lauraine
Published: November 2007

Early stages in the development of Meliola palmicola and M. peleae on their respective hosts were studied and are illustrated with photomicrographs. Ascospores of these fungi germinate from a terminal cell to produce short stalk cells with capitate hyphopodia; typically, a single hyphopodium is formed by M. palmicola, whereas three are usually produced in M. peleae. Growth from the terminal cell is limited to the production of these structures, and subsequent development of the fungus colony occurs through outgrowths from other cells of the ascospore. Development of the colony appears to be dependent on the successful establishment of the parasitic relationship by the initial outgrowths from the ascospore.
Influence of plant development stage, temperature, and plant hormones on chromosome doubling of barley haploids using colchicine
Authors: Thiebaut J. , Kasha K. J. , Tsai A.
Published: November 2007

Varying colchicine treatments in the direction of earlier developmental stages, higher temperatures, and addition of N-6-benzyl adenine (BA) was without effect on percent of surviving plants that set seed. However, all three factors did increase the extent of doubling within the plant. This increase in size of doubled sectors suggests that the addition of BA and the shift to higher temperatures stimulate cell divisions in meristematic regions. The addition of gibberellic acid (GA3), on the other hand, led to a decrease in size of doubled sectors. Comparisons among experiments, although nonorthogonal for genotype, confirmed that GA3 increased plant survival after colchicine treatment and indicated that BA had a similar effect at 20 to 22 °C. However, the combination of high temperature (32 °C) and addition of BA increased plant lethality following colchicine treatment.
Interrelationships of vegetative growth and assimilate distribution of Citrus limettioides seedlings in response to root-applied GA3 and SADH
Authors: Ben-Gad D. Y. , Altman A. , Monselise S. P.
Published: November 2007

The effects of root-applied GA3 or SADH on vegetative growth, distribution of 14C-labelled assimilates, and starch content of various organs of Citrus limettioides seedlings were investigated. In contrast with the uniform elongation rate of control seedlings, GA3 induced an initial high elongation rate which later dropped to the level of the control, resulting in considerably longer seedlings. Final leaf area was drastically reduced by GA3 root treatment, which also induced both earlier appearance of thorns and more and shorter thorns per seedlings. Elongation rate of SADH-treated seedlings was initially retarded, but vigorous growth was later resumed for a short period, causing treated seedlings to be eventually similar to, or slightly longer than, controls. SADH did not affect the number and timing of thorn emergence but considerably promoted their elongation.The effect of GA3 and SADH on the vegetative growth was closely related to their differential effects on distribution of assimilates and starch in shoot and root tissues. A high growth rate was characterized by an increased supply of 14C-labelled assimilates to shoot organs and especially to buds as well as by a greater utilization of starch. The opposite was found in the root system, resulting in a significant modification of shoot–root ratios of both 14C-Iabelled assimilates and starch. The changes in 14C-labelled assimilates and starch usually preceded changes in growth, thus suggesting that GA3 and SADH effects on growth are mediated via their effects on the activity of apical sinks.
Binary pathways for analysis of primary infection and host response in populations of powdery mildew fungi
Authors: Johnson L. E. B. , Bushnell W. R. , Zeyen R. J.
Published: November 2007

Events in development of powdery mildew fungi from spore germination to formation of the first haustorium and hypha, including host cell responses, were cataloged using a binary pathway system. This system branches at "event-points" which represent sites of "on–off" alternatives for the occurrence of an event or sites where one of two alternative events occur. The system permits statistical comparisons of probabilities for different events within a given host–parasite combination and for specific events in different host–parasite combinations. Data from the binary pathway system can be converted to percentage of total spores to show the size of the fungal population which passes each event-point, or the data can be resorted to determine how many germlings are associated with a given combination of events.The binary system was used with data for powdery mildew of barley obtained from whole leaves harvested 1 and 2 days after inoculation, which were fixed and then stained with acid fuchsin and aniline blue. Approximately 5000 germinated spores were observed for each host–parasite combination. In compatible combinations, 6–7% of spores failed to produce a normal germ tube and (or) appressorium after germination, and 9–11% of spores failed to produce a penetration peg at the first appressorial lobe. In epidermal cells distant from stomates, only 2–3% of the fungal population produced haustoria and hyphae. The fungus had a high probability of inducing papillae in such cells and a low probability of passing through papillae. In cells near stomates, papillae were less frequent and 46–52% of the population produced haustoria and hyphae.In an incompatible host–parasite combination (with the M1a gene), most penetration pegs terminated in papillae regardless of host cell location. In cells distant from stomates, virtually no germlings grew beyond papillae. In cells near stomates, 11% of the fungal population either penetrated a papilla or entered a host cell without inducing papillae. Of these, about half induced host cell collapse either before or after haustorium formation and half stopped growing after haustorium formation without inducing cell collapse. Thus, incompatability was expressed at several stages in fungal development.
Comparison of anther development in genic male-sterile (ms10) and in male-fertile corn (Zea mays) from light microscopy and scanning electron microscopy
Authors: Cheng P. C. , Greyson R. I. , Walden D. B.
Published: November 2007

Anther ontogeny of a genic male-sterile mutant (ms 10/ms 10) and a related fertile cultivar of Zea was studied from the primordial stage through to tassel maturity. From material glutaraldehyde–formalin fixed, OsO4 postfixed, and plastic embedded, light microscopy of 0.7-μm sections revealed no developmental differences between the two until the young microspore stage. Vacuolation or cytoplasmic disintegration of tapetal cells was detected in male-sterile anthers at this stage. Disintegration of microspores was not detected until the intermediate microspore stage. By the young pollen stage, tapetal cells were highly disorganized and degeneration of the middle layer and endothecium was apparent. No endothecial wall thickenings developed in male-sterile anthers.In normal anther development in Zea, endothecial thickenings are found only at the anterior and posterior ends of the anther. A highly ridged anther cuticle, which is essentially absent in male-sterile anthers, is a common feature of fertile flowers. Anther dehiscence involves a separation of the epidermis from the underlying parenchyma of the connective to form a large pollen cavity from the two microsporangial locules. This process does not involve endothecial fibrous wall thickenings as they are not present over the bulk of the anther. Formation of the anterior pore is a separate process which involves changes in the endothecium wall thickenings.During normal anther development starch accumulates in the endothecium and epidermis at the precallose stage and disappears during the young microspore stage. No differences were noted in the male-sterile anthers. During the formation of normal pollen, considerable starch accumulation is evident. However, none is deposited at this late stage in the male-sterile anther.