bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sexual Systems and Ecological Correlates in an Azonal Tropical Forests, SW China
Authors: Chen Xin‐Sheng , Li Qing‐Jun 
Published: October 2007

ABSTRACTUnlike the seriate lowland rain forests in SE Asia, the tropical vegetation of Xishuangbanna (SW China) has developed in habitats with comparatively lower temperatures and precipitation. Consequently, although most of the families and genera of the flora are components of tropical ecosystems, many have reached their distribution limits in latitude. Selection pressures on sexual systems in these environments may be different from that experienced in lowland tropical regions. Here, we examine the sexual systems of 685 species of flowering plants belonging to 109 families and 356 genera based on 42 plots with a total area of 15.4 ha and compare our results with surveys of sexual systems from other tropical ecosystems. Among these species, 60.6 percent were hermaphroditic, 14.3 percent were monoecious, and 25.1 percent were dioecious. The percentage of dioecious sexual system among tree species (26.1%) was similar or higher than that of other tropical tree floras. Monoecy was significantly associated with the tree growth form and was relatively common in seasonal forest vegetation. Sexual systems involving unisexual flowers (dicliny) are particularly well represented in the tropical forests of Xishuangbanna accounting for 39.4 percent of all species surveyed. This pattern may be associated with the prevalence of relatively small inconspicuous flowers in the tropical forests of SE Asia and their correlation with diclinous sexual systems generally.
Community Structure of Large Mammals in Tropical Montane and Lowland Forest in the Tenasserim‐Dawna Mountains, Thailand
Authors: Steinmetz Robert , Chutipong Wanlop , Seuaturien Naret , Chirngsaard Erb 
Published: October 2007

ABSTRACTMontane evergreen forest in SE Asia is structurally and floristically different from lowland habitats. The response of large mammals to this variation is largely unexplored. We used sign transects to compare community structure of large mammals in montane (>1100 m), and lowland (<1100 m) forest types over 4 yr in western Thailand. Relative abundance of most ungulate species was significantly higher in lowland forest, except for elephant (Elephas maximus) and tapir (Tapirus indicus), which were most abundant in montane forest (based on chi‐square tests of sign encounter rates). Sexual segregation was apparent for gaur (Bos gaurus): breeding herds were concentrated in the lowlands, whereas single males were most abundant in montane forest. Large cat abundance was similar in both elevation zones. Tapir, single gaur, and bears (Ursus spp.) characterized the montane mammal community, whereas most other ungulate species and social groups were indicative of lowland forest (based on discriminant function analysis). Results pertain only to the dry season; seasonal movements could alter the patterns we observed. Differences in community structure between elevation zones are hypothesized to result from differences in habitat structure, resource availability, and human impacts. Lowland forests provide bamboo, grass, and mineral licks, probably accounting for higher ungulate densities despite higher levels of hunting. These resources are scarce in montane forest. However, montane forest functions as a refuge for at least three globally threatened large mammal species, because commercial hunting is concentrated in the more accessible lowlands.
Word Classes
Authors: Rijkhoff Jan 
Published: October 2007

AbstractThis article1provides an overview of recent literature and research on word classes, focusing in particular on typological approaches to word classification. The cross‐linguistic classification of word class systems (or parts‐of‐speech systems) presented in this article is based on statements found in grammatical descriptions of some 50 languages, which together constitute a representative sample of the world's languages. It appears that there are both quantitative and qualitative differences between word class systems of individual languages. Whereas some languages employ a parts‐of‐speech system that includes the categories verb, noun, adjective and adverb, other languages may use only a subset of these four lexical categories. Furthermore, quite a few languages have a major word class whose members cannot be classified in terms of the categories verb–noun–adjective–adverb, because they have properties that are strongly associated with at least two of these four traditional word classes (e.g. adjective and adverb). Finally, this article discusses some of the ways in which word class distinctions interact with other grammatical domains, such as syntax and morphology.
Bioaerosol sampling for the detection of aerosolized influenza virus
Authors: Blachere Francoise M. , Lindsley William G. , Slaven James E. , Green Brett J. , Anderson Stacey E. , Chen Bean T. , Beezhold Don H. 
Published: October 2007

Background Influenza virus was used to characterize the efficacy of a cyclone‐based, two‐stage personal bioaerosol sampler for the collection and size fractionation of aerosolized viral particles.Methods A Collison single‐jet nebulizer was used to aerosolize the attenuated FluMist® vaccine into a calm‐air settling chamber. Viral particles were captured with bioaerosol samplers that utilize 2 microcentrifuge tubes to collect airborne particulates. The first tube (T1) collects particles greater than 1.8 μm in diameter, while the second tube (T2) collects particles between 1.0 and 1.8 μm, and the back‐up filter (F) collects submicron particles. Following aerosolization, quantitative PCR was used to detect and quantify H1N1 and H3N2 influenza strains.Results Based on qPCR results, we demonstrate that aerosolized viral particles were efficiently collected and separated according to aerodynamic size using the two‐stage bioaerosol sampler. Most viral particles were collected in T2 (1‐1.8 μm) and on the back‐up filter (< 1 μm) of the bioaerosol sampler. Furthermore, we found that the detection of viral particles with the two‐stage sampler was directly proportional to the collection time. Consequently, viral particle counts were significantly greater at 40 minutes in comparison to 5, 10 and 20 minute aerosol collection points.Conclusions Due to a lack of empirical data, aerosol transmission of influenza is often questioned. Using FluMist®, we demonstrated that a newly developed bioaerosol sampler is able to recover and size fractionate aerosolized viral particles. This sampler should be an important tool for studying viral transmission in clinical settings and may significantly contribute towards understanding the modes of influenza virus transmission.
DNA‐ligand Binding Mode Discrimination by Characterizing Fluorescence Resonance Energy Transfer Through Lifetime Measurements with Picosecond Resolution
Authors: Nardo Luca , Bondani Maria , Andreoni Alessandra 
Published: October 2007

AbstractWe describe a method for distinguishing between minor groove binders and base intercalators that is based on measurements of the fluorescence lifetime of a donor (D) in the presence of an acceptor (A). The D–A pair is separated by a short double helix DNA with which the ligands interact. By plotting the D fluorescence lifetime as a function of the ligand‐to‐base pair concentration ratio we find a clear signature that distinguishes between the two binding mechanisms: minor groove binding induces an asymptotic decrease of the D fluorescence lifetime, while intercalation gives a monotonically increasing lifetime and the appearance of an additional short lifetime. We assayed Quinacrine, Hoechst and 4′–6′diamidine‐2‐phenyl indole, which in control experiments performed on oligodeoxyribonucleotides (oligos) lacking the A are demonstrated not to interfere with the D fluorescence. The changes in fluorescence lifetimes measured in the case of dual‐labeled oligos are thus caused by structural changes in the DNA that modify the D–A distance. The appearance of the short‐lived transient in the fluorescence decay of Ds attached to dual‐labeled oligos upon binding of an intercalator can be interpreted as denaturation.
OT‐674 Suppresses Photooxidative Processes Initiated by an RPE Lipofuscin Fluorophore
Authors: Zhou Jilin , Jang Young P. , Chang Stanley , Sparrow Janet R. 
Published: October 2007

AbstractThe pathological processes involved in age‐related macular degeneration (AMD) include retinal pigment epithelial (RPE) cell degeneration; oxidative mechanisms likely contribute to the demise of these cells. Indeed, RPE cells may be particularly susceptible to photooxidative mechanisms since they accumulate retinoid‐derived photoreactive compounds that constitute the lipofuscin of the cell. Thus we undertook to test the capacity of OT‐674, the reduction product (Tempol‐H) of the nitroxide Tempol, to suppress photooxidative processes initiated by the RPE lipofuscin fluorophore A2E. Accordingly, when ARPE‐19 cells that had accumulated A2E were irradiated at 430 nm, pretreatment with OT‐674 (0.01–10 mm) was found to confer a resistance to cell death. Monitoring by quantitative HPLC also showed that OT‐674 reduced A2E photooxidation in a cell‐free system. Moreover, when presented with a singlet oxygen generator, OT‐674 served as a quencher of singlet oxygen that was more effective than Trolox and α‐tocopherol. We conclude that OT‐674 is a potent antioxidant that suppresses photooxidative processes generated in cultured RPE cells by the lipofuscin fluorophore A2E. As oxidative damage to RPE cells is considered to be a risk factor for AMD, antioxidant therapy with OT‐674 may serve a protective role.
Identification of Sites Within a Monomeric Red Fluorescent Protein that Tolerate Peptide Insertion and Testing of Corresponding Circular Permutations
Authors: Li Yankun , Sierra Aillette M. , Ai Hui‐wang , Campbell Robert E. 
Published: October 2007

AbstractIn recent years the class of known fluorescent proteins (FPs) has dramatically expanded as an ever‐increasing numbers of variants and homologs of the green fluorescent protein (GFP) from Aequorea jellyfish have been either engineered in the lab or discovered in other marine organisms. The red fluorescent protein (RFP) from Discosoma coral (also known as dsFP583 and DsRed) has proven to be a particularly fruitful progenitor of variants with biochemical and spectroscopic properties conducive to applications in live cell imaging. We have investigated the tolerance of an engineered monomeric descendent of Discosoma RFP, known as mCherry, towards peptide insertion and circular permutation. Starting from a random library of insertion variants, we identified six genetically distinct sites localized in three different loops where a sequence of five residues could be inserted without abolishing the ability of the protein to form its intrinsic red fluorescent chromophore. For each of these insertion variants, a corresponding circular permutation variant was created in which the original N‐ and C‐termini were connected by a six‐residue linker and new termini were introduced at the site of the insertion. All six circular permutation variants had significantly diminished brightness relative to the analogous insertion variants. The most promising circular permutation variant has termini at the position corresponding to residue 184 of mCherry and retains 37% of the intrinsic fluorescent brightness of mCherry. These circularly permuted variants may serve as the foundation for construction of genetically encoded Ca2+ sensors analogous to the previously reported camgaroo, pericam and G‐CaMP sensors based on variants of Aequorea GFP.
Combination Therapy with Antiangiogenic Treatment and Photodynamic Therapy for the Nude Mouse Bearing U87 Glioblastoma
Authors: Jiang Feng , Zhang Xuepeng , Kalkanis Steven N. , Zhang ZhengGang , Yang Hongyan , Katakowski Mark , Hong Xin , Zheng Xuguang , Zhu Zhenping , Chopp Michael 
Published: October 2007

AbstractThe objective of this study was to evaluate the effects of combination therapy with photodynamic therapy (PDT) and a novel antiangiogenic regimen using monoclonal antibodies against both vascular endothelial growth factor receptors (VEGFR)‐1 (MF1) and VEGFR‐2 (DC101) on intracranial glioblastoma xenografts in nude mice. Nude mice bearing intracerebral U87 glioblastoma were treated with PDT and the antiangiogenic regimen (MF1 and DC101) either alone or in combination, while those left untreated served as tumor controls. Tumor volume and animal survival time were analyzed to evaluate the outcome of different treatment modalities. In addition, the immunohistochemical expression of VEGF in the brain adjacent to the tumor, von Willebrand factor (vWF), apoptotic, and proliferative markers in the tumor area were examined. PDT or MF1 + DC101 alone significantly reduced the tumor volume and prolonged the survival time of glioma‐implanted animals. Combined therapy markedly reduced tumor volume and increased survival time with significantly better outcomes than both monotherapies. Both vWF and VEGF levels significantly increased after PDT while they both significantly decreased after antiangiogenic treatment, compared with no treatment. PDT plus antiangiogenic treatment led to significant decreases in both vWF and VEGF expression, compared with PDT alone. Either PDT or antiangiogenic treatment alone significantly increased tumor cell apoptosis compared with no treatment, while combination therapy resulted in further augmentation of apoptosis. Antiangiogenic treatment with or without PDT significantly decreased tumor cell proliferation, compared with either no treatment or PDT alone. In summary, we demonstrate both significant inhibition of tumor growth and extended survival of mice treated by the combination therapy with PDT and antiangiogenic agents, compared with each single treatment, suggesting that the combination therapy may be a promising strategy to improve clinical outcomes in glioblastoma.
The Photoyellowing of Stilbene‐derived Fluorescent Whitening Agents—Mass Spectrometric Characterization of Yellow Photoproducts
Authors: Dyer Jolon M. , Cornellison Charisa D. , Bringans Scott D. , Maurdev George , Millington Keith R. 
Published: October 2007

AbstractThe application of fluorescent whitening agents (FWAs) significantly accelerates the photoyellowing of wool and silk under exposure to the ultraviolet and visible components of sunlight <500 nm. The photochemistry involved in this process is poorly understood, particularly the role of photoproducts derived directly from the FWA itself. Hydroxylation was identified as the key initial mechanism of photodegradation leading to coloration of the solution in the irradiation of the stilbene‐derived FWA 4,4′‐bis(2‐sulfostyryl)biphenyl (DSBP) in the presence of hydrogen peroxide (H2O2). Polyhydroxylated DSBP derivatives were implicated as critical intermediates in the formation of yellow photoproducts under these conditions. The formation of trace quantities of DSBP quinone derivatives subsequent to hydroxylation was identified as the key cause of DSBP photoyellowing. These results are the first successful characterization of yellow photoproducts resulting directly from irradiation of a stilbene‐based FWA. Formation of these yellow stilbene‐based FWA‐derived photoproducts may occur on the surface of FWA‐treated wool exposed to simulated sunlight, as previous work has shown that H2O2 is photogenerated when wet FWA‐treated wool is exposed to light. These results therefore suggest that yellow FWA‐derived photoproducts contribute to the accelerated photoyellowing of FWA‐treated wool.
Thwarting the Need to Belong: Understanding the Interpersonal and Inner Effects of Social Exclusion
Authors: Baumeister Roy F. , Brewer Lauren E. , Tice Dianne M. , Twenge Jean M. 
Published: October 2007

AbstractThe need to belong is a powerful motivational basis for interpersonal behavior, and it is thwarted by social exclusion and rejection. Laboratory work has uncovered a destructive set of consequences of being socially excluded, such as increased aggressiveness and reduced helpfulness toward new targets. Rejected persons do, however, exhibit a cautious interest in finding new friends. Theory and intuition associate social exclusion with emotional distress, but laboratory research finds instead that the first response is a reduced sensitivity to pain and an emotional insensitivity that hampers empathy and may contribute to a variety of interpersonal behaviors. Self‐regulation and intelligent thought are also impaired as a direct result of being rejected.
Failures in Clinical Treatment of
Staphylococcus aureus
Infection with Daptomycin Are Associated with Alterations in Surface Charge, Membrane Phospholipid Asymmetry, and Drug Binding
Authors: Jones Tiffanny , Yeaman Michael R. , Sakoulas George , Yang Soo-Jin , Proctor Richard A. , Sahl Hans-Georg , Schrenzel Jacques , Xiong Yan Q. , Bayer Arnold S. 
Published: October 2007

ABSTRACT

Increasingly frequent reports have described the in vivo loss of daptomycin susceptibility in association with clinical treatment failures. The mechanism(s) of daptomycin resistance is not well understood. We studied an isogenic set of
Staphylococcus aureus
isolates from the bloodstream of a daptomycin-treated patient with recalcitrant endocarditis in which serial strains exhibited decreasing susceptibility to daptomycin. Since daptomycin is a membrane-targeting lipopeptide, we compared a number of membrane parameters in the initial blood isolate (parental) with those in subsequent daptomycin-resistant strains obtained during treatment. In comparison to the parental strain, resistant isolates demonstrated (i) enhanced membrane fluidity, (ii) increased translocation of the positively charged phospholipid lysyl-phosphotidylglycerol to the outer membrane leaflet, (iii) increased net positive surface charge (
P
< 0.05 versus the parental strain), (iv) reduced susceptibility to daptomycin-induced depolarization, permeabilization, and autolysis (
P
< 0.05 versus the parental strain), (v) significantly lower surface binding of daptomycin (
P
< 0.05 versus the parental strain), and (vi) increased cross-resistance to the cationic antimicrobial host defense peptides human neutrophil peptide 1 (hNP-1) and thrombin-induced platelet microbicidal protein 1 (tPMP-1). These data link distinct changes in membrane structure and function with in vivo development of daptomycin resistance in
S. aureus
. Moreover, the cross-resistance to hNP-1 and tPMP-1 may also impact the capacity of these daptomycin-resistant organisms to be cleared from sites of infection, particularly endovascular foci.
Colistin Heteroresistance in
Acinetobacter
and Its Association with Previous Colistin Therapy
Authors: Hawley Joshua S. , Murray Clinton K. , Jorgensen James H. 
Published: October 2007

ABSTRACT

Colistin heteroresistance has been reported among
Acinetobacter
isolates; however, its association with prior colistin therapy has not been not described. A population analysis profile identified resistant
Acinetobacter
subpopulations from colistin-susceptible clinical isolates. The proportion of cells exhibiting heteroresistance was significantly higher among isolates recovered from patients treated with colistin.
Potential Use of Poly-
N
-Acetyl-β-(1,6)-Glucosamine as an Antigen for Diagnosis of Staphylococcal Orthopedic-Prosthesis-Related Infections
Authors: Sadovskaya Irina , Faure Stéphanie , Watier Denis , Leterme Damien , Chokr Ali , Girard Julien , Migaud Henry , Jabbouri Saïd 
Published: October 2007

ABSTRACT

Staphylococcus aureus
and coagulase-negative staphylococci are microorganisms most frequently isolated from orthopedic-implant-associated infections. Their capacity to maintain these infections is thought to be related to their ability to form adherent biofilms. Poly-
N
-acetyl-β-(1,6)-glucosamine (PNAG) is an important constituent of the extracellular biofilm matrix of staphylococci. In the present study, we explored the possibility of using PNAG as an antigen for detecting antibodies in the blood sera of patients with staphylococcal orthopedic-prosthesis-associated infections. First, we tested the presence of anti-PNAG antibodies in an animal model, in the blood sera of guinea pigs that developed an implant-associated infection caused by biofilm-forming, PNAG-producing strains of
Staphylococcus epidermidis
. Animals infected with
S. epidermidis
RP62A showed levels of anti-PNAG immunoglobulin G (IgG) significantly higher than those of the control group. The comparative study of healthy individuals and patients with staphylococcal prosthesis-related infections showed that (i) relatively high levels of anti-PNAG IgG were present in the blood sera of the healthy control group, (ii) the corresponding levels in the infected patients were slightly but not significantly higher, and (iii) only 1 of 10 patients had a level of anti-PNAG IgM significantly higher than that of the control group. In conclusion, the encouraging results obtained in the animal study could not be readily applied for the diagnosis of staphylococcal orthopedic-prosthesis-related infections in humans, and PNAG does not seem to be an appropriate antigen for this purpose. Further studies are necessary to determine whether the developed enzyme-linked immunosorbent assay method could serve as a complementary test in the individual follow-up treatment of such infections caused by PNAG-producing staphylococci.
Therapeutic Immunization with Human Immunodeficiency Virus Type 1 (HIV-1) Peptide-Loaded Dendritic Cells Is Safe and Induces Immunogenicity in HIV-1-Infected Individuals
Authors: Connolly Nancy C. , Whiteside Theresa L. , Wilson Cara , Kondragunta Venkatswarlu , Rinaldo Charles R. , Riddler Sharon A. 
Published: October 2007

ABSTRACT
Treatments for human immunodeficiency virus type 1 (HIV-1)-positive individuals that augment HIV-1 suppression and have potential for achieving long-term control of HIV-1 viremia in the absence of antiretroviral therapy (ART) are urgently needed. We therefore conducted a phase I, clinical safety trial of a dendritic cell (DC)-based vaccination strategy as immunotherapy for HIV-1-positive individuals on ART. We studied 18 HIV-1-positive subjects on ART who underwent leukapheresis to obtain peripheral blood mononuclear cells for DC generation from monocytes cultured with cytokines. Mature DC were pulsed with three HIV-1 HLA*A0201 Gag, Env, and Pol peptides and one influenza A virus matrix protein peptide. The vaccine was administered to donors randomized to receive two vaccinations, either intravenously or subcutaneously. The primary end points were safety and tolerability of two doses of peptide-DC vaccine (3 million versus 10 million). Secondary end points included gamma interferon (IFN-γ) enzyme-linked immunospot assay responses and clinical correlates of an immune response to vaccination. Autologous DC-peptide vaccine was safe, well tolerated, and feasible for use in all participants. Adverse events were rare. Although the trial was not powered to assess an immunologic response, a significantly increased frequency of HIV-1 peptide-specific IFN-γ-positive cells was observed 2 weeks following the second vaccine, with three individuals responding to all four peptides. DC vaccination was safe, was feasible, and showed promise of immunogenicity in ART-treated, HIV-1-positive individuals. Additional studies of DC immunization strategies for HIV-1 infection are warranted.