bluuebunny/crossref_metadata_2025 huggingface dataset:
Wave motion in relaxation-testing of nonlinear elastic media
Authors: Nekouzadeh Ali , Genin Guy M , Bayly Philip V , Elson Elliot L
Published: May 2005

Relaxation testing is a fundamental tool for mechanical characterization of viscoelastic materials. Inertial effects are usually neglected when analysing these tests. However, relaxation tests involve sudden stretching of specimens, which causes propagation of waves whose effects may be significant. We study wave motion in a nonlinear elastic model specimen and derive expressions for the conditions under which loading may be considered to be quasi-static. Additionally, we derive expressions for wave properties such as wave speed and the time needed to reach a steady-state wave pattern. These expressions can be used to deduce nonlinear elastic material properties from dynamic experiments.
Homogenization of a fibre/sphere with an inhomogeneous interphase for the effective elastic moduli of composites
Authors: Shen Lianxi , Li Jackie
Published: May 2005

An effective interphase model (EIM) and a uniform replacement model (URM) are proposed to study the effect of an inhomogeneous interphase with varying elastic properties in the radial direction on the effective elastic moduli of composites reinforced by fibres/spheres. The central idea of these models is to convert a fibre/sphere with its interphase into a two-phase or homogeneous fibre/sphere. Then, the strain energy changes can be obtained using the three-phase model or Eshelby's solution. Detailed comparisons with the finite-element method (FEM) results of the strain energy changes for various possible material combinations of fibre/sphere, interphase and matrix are carried out to check the validity of the two models. Moreover, the other two existing models, the uniform interphase model (UIM) and differential replacement model (DRM), are compared with the new ones. It is shown that the validity of these analytical models depends on the material combinations. The EIM can be valid for general cases, while the simple URM is only valid for some cases. The validity ranges of the two existing models lie between those of the two new ones. Finally, the expressions of the effective elastic moduli of composites involving an inhomogeneous interphase are given by combining these models and the Mori–Tanaka method. The application of these expressions is illustrated through three examples and further comparisons with FEM results are also given.
Inferences about information flow and dispersal for spatially extended population systems using time-series data
Authors: Nichols J.M
Published: May 2005

This work explores an information-theoretic approach to drawing inferences about coupling of spatially extended ecological populations based solely on time-series of abundances. The efficacy of the approach, time‐delayed mutual information, was explored using a spatially extended predator–prey model system in which populations at different patches were coupled via diffusive movement. The approach identified the relative magnitude and direction of information flow resulting from animal movement between populations, the change in information flow as a function of distance separating populations, and the diffusive nature of the information flow. In addition, when the diffusive movement was eliminated from the model, mutual information correctly provided no evidence of information flow, even when population synchrony was generated by a common environmental driving function. Thus, for this model system, time‐delayed mutual information was useful in discriminating between the Moran effect and animal movement as causes of population synchrony, as well as in characterizing dispersal in terms of direction, relative speed and diffusive nature.
Adaptive significance of avian beak morphology for ectoparasite control
Authors: Clayton Dale H , Moyer Brett R , Bush Sarah E , Jones Tony G , Gardiner David W , Rhodes Barry B , Goller Franz
Published: May 2005

The beaks of Darwin's finches and other birds are among the best known examples of adaptive evolution. Beak morphology is usually interpreted in relation to its critical role in feeding. However, the beak also plays an important role in preening, which is the first line of defence against harmful ectoparasites such as feather lice, fleas, bugs, flies, ticks and feather mites. Here, we show a feature of the beak specifically adapted for ectoparasite control. Experimental trimming of the tiny (1–2 mm) maxillary overhang of rock pigeons (Columba livia) had no effect on feeding efficiency, yet triggered a dramatic increase in feather lice and the feather damage they cause. The overhang functions by generating a shearing force against the tip of the lower mandible, which moves forward remarkably quickly during preening, at up to 31 times per second. This force damages parasite exoskeletons, significantly enhancing the efficiency of preening for parasite control. Overhangs longer than the natural mean of 1.6 mm break significantly more often than short overhangs. Hence, stabilizing selection will favour overhangs of intermediate length. The adaptive radiation of beak morphology should be re-assessed with both feeding and preening in mind.
Sperm competition and the evolution of male reproductive anatomy in rodents
Authors: Ramm Steven A , Parker Geoffrey A , Stockley Paula
Published: May 2005

Sperm competition is a pervasive selective force in evolution, shaping reproductive anatomy, physiology and behaviour. Here, we present comparative evidence that varying sperm competition levels account for variation in the male reproductive anatomy of rodents, the largest and most diverse mammalian order. We focus on the sperm-producing testes and the accessory reproductive glands, which produce the seminal fluid fraction of the ejaculate. We demonstrate a positive association between relative testis size and the prevalence of within-litter multiple paternity, consistent with previous analyses in which relative testis size has been found to correlate with sperm competition levels inferred from social organization and mating systems. We further demonstrate an association between sperm competition level and the relative size of at least two accessory reproductive glands: the seminal vesicles and anterior prostate. The size of the major product of these glands—the copulatory plug—is also found to vary with sperm competition level. Our findings thus suggest that selection for larger plugs under sperm competition may explain variation in accessory gland size, and highlight the need to consider both sperm and non-sperm components of the male ejaculate in the context of post-copulatory sexual selection.
Novel, benign, solid catalysts for the oxidation of hydrocarbons
Authors: Ratnasamy Paul , Raja Robert , Srinivas Darbha
Published: May 2005

The catalytic properties of two classes of solid catalysts for the oxidation of hydrocarbons in the liquid phase are discussed: (i) microporous solids, encapsulating transition metal complexes in their cavities and (ii) titanosilicate molecular sieves. Copper acetate dimers encapsulated in molecular sieves Y, MCM-22 and VPI-5 use dioxygen to regioselectivelyortho-hydroxylatel-tyrosine tol-dopa, phenol to catechol and cresols to the correspondingo-dihydroxy ando-quinone compounds. Monomeric copper phthalocyanine and salen complexes entrapped in zeolite-Y oxidize methane to methanol, toluene to cresols, naphthalene to naphthols, xylene to xylenols and phenol to diphenols. Trimeric μ3-oxo-bridged Co/Mn cluster complexes, encapsulated inside Y-zeolite, oxidizepara-xylene, almost quantitatively, to terephthalic acid. In almost all cases, the intrinsic catalytic activity (turnover frequency) of the metal complex is enhanced very significantly, upon encapsulation in the porous solids. Spectroscopic and electrochemical studies suggest that the geometric distortions of the complex on encapsulation change the electron density at the metal ion site and its redox behaviour, thereby influencing its catalytic activity and selectivity in oxidation reactions.

Titanosilicate molecular sieves can oxidize hydrocarbons using dioxygen when loaded with transition metals like Pd, Au or Ag. The structure of surface Ti ions and the type of oxo-Ti species generated on contact with oxidants depend on several factors including the method of zeolite synthesis, zeolite structure, solvent, temperature and oxidant. Although, similar oxo-Ti species are present on all the titanosilicates, their relative concentrations vary among different structures and determine the product selectivity.
Controlling automotive exhaust emissions: successes and underlying science
Authors: Twigg Martyn V
Published: May 2005

Photochemical reactions of vehicle exhaust pollutants were responsible for photochemical smog in many cities during the 1960s and 1970s. Engine improvements helped, but additional measures were needed to achieve legislated emissions levels. First oxidation catalysts lowered hydrocarbon and carbon monoxide, and later nitrogen oxides were reduced to nitrogen in a two-stage process. By the 1980s, exhaust gas could be kept stoichiometric and hydrocarbons, carbon monoxide and nitrogen oxides were simultaneously converted over a single ‘three-way catalyst’. Today, advanced three-way catalyst systems emissions are exceptionally low. NOxcontrol from lean-burn engines demands an additional approach because NO cannot be dissociated under lean conditions. Current lean-burn gasoline engine NOxcontrol involves forming a nitrate phase and periodically enriching the exhaust to reduce it to nitrogen, and this is being modified for use on diesel engines. Selective catalytic reduction with ammonia is an alternative that can be very efficient, but it requires ammonia or a compound from which it can be obtained. Diesel engines produce particulate matter, and, because of health concerns, filtration processes are being introduced to control these emissions. On heavy duty diesel engines the exhaust gas temperature is high enough for NO in the exhaust to be oxidised over a catalyst to NO2that smoothly oxidises particulate material (PM) in the filter. Passenger cars operate at lower temperatures, and it is necessary to periodically burn the PM in air at high temperatures.
SMC proteins and chromosome mechanics: from bacteria to humans
Authors: Hirano Tatsuya
Published: May 2005

Chromosome cohesion and condensation are essential prerequisites of proper segregation of genomes during mitosis and meiosis, and are supported by two structurally related protein complexes, cohesin and condensin, respectively. At the core of the two complexes lie members of the structural maintenance of chromosomes (SMC) family of ATPases. SMC proteins are also found in most bacterial and archaeal species, implicating the existence of an evolutionarily conserved theme of higher-order chromosome organization and dynamics. SMC dimers adopt a two-armed structure with an ATP-binding cassette (ABC)-like domain at the distal end of each arm. This article reviews recent work on the bacterial and eukaryotic SMC protein complexes, and discusses current understanding of how these uniquely designed protein machines may work at a mechanistic level. It seems most likely that the action of SMC proteins is highly dynamic and plastic, possibly involving a diverse array of intramolecular and intermolecular protein–protein interactions.
Merotelic kinetochores in mammalian tissue cells
Authors: Salmon E.D , Cimini D , Cameron L.A , DeLuca J.G
Published: May 2005

Merotelic kinetochore attachment is a major source of aneuploidy in mammalian tissue cells in culture. Mammalian kinetochores typically have binding sites for about 20–25 kinetochore microtubules. In prometaphase, kinetochores become merotelic if they attach to microtubules from opposite poles rather than to just one pole as normally occurs. Merotelic attachments support chromosome bi-orientation and alignment near the metaphase plate and they are not detected by the mitotic spindle checkpoint. At anaphase onset, sister chromatids separate, but a chromatid with a merotelic kinetochore may not be segregated correctly, and may lag near the spindle equator because of pulling forces toward opposite poles, or move in the direction of the wrong pole. Correction mechanisms are important for preventing segregation errors. There are probably more than 100 times as many PtK1 tissue cells with merotelic kinetochores in early mitosis, and about 16 times as many entering anaphase as the 1% of cells with lagging chromosomes seen in late anaphase. The role of spindle mechanics and potential functions of the Ndc80/Nuf2 protein complex at the kinetochore/microtubule interface is discussed for two correction mechanisms: one that functions before anaphase to reduce the number of kinetochore microtubules to the wrong pole, and one that functions after anaphase onset to move merotelic kinetochores based on the ratio of kinetochore microtubules to the correct versus incorrect pole.
A comparison of the ability of XMAP215 and tau to inhibit the microtubule destabilizing activity of XKCM1
Authors: Noetzel Tim L , Drechsel David N , Hyman Anthony A , Kinoshita Kazuhisa
Published: May 2005

During mitosis, microtubules not only grow fast, but also have a high rate of catastrophe. This is achieved in part by the activity of the MAP, XMAP215, which can stimulate the growth rate of microtubules without fully inhibiting the function of the catastrophe-kinesin XKCM1. We do not know whether this activity is particular to XMAP215, or is a general property of all MAPs. Here, we compare the activities of XMAP215 with the neuronal MAP tau, in opposing the destabilizing activity of the non-conventional kinesin XKCM1. We show that tau is a much more potent inhibitor of XKCM1 than XMAP215. Because tau completely suppresses XKCM1 activity, even at low concentrations, the combination of tau and XKCM1 is unable to generate mitotic microtubule dynamics.
Two distinct pathways responsible for the loading of CENP-A to centromeres in the fission yeast cell cycle
Authors: Takahashi Kohta , Takayama Yuko , Masuda Fumie , Kobayashi Yasuyo , Saitoh Shigeaki
Published: May 2005

CENP-A is a centromere-specific histone H3 variant that is- essential for faithful chromosome segregation in all eukaryotes thus far investigated. We genetically identified two factors, Ams2 and Mis6, each of which is required for the correct centromere localization of SpCENP-A (Cnp1), the fission yeast homologue of CENP-A. Ams2 is a cell-cycle-regulated GATA factor that localizes on the nuclear chromatin, including on centromeres, during the S phase. Ams2 may be responsible for the replication-coupled loading of SpCENP-A by facilitating nucleosomal formation during the S phase. Consistently, overproduction of histone H4, but not that of H3, suppressed the defect of SpCENP-A localization in Ams2-deficient cells. We demonstrated the existence of at least two distinct phases for SpCENP-A loading during the cell cycle: the S phase and the late-G2 phase. Ectopically induced SpCENP-A was efficiently loaded onto the centromeres in G2-arrested cells, indicating that SpCENP-A probably undergoes replication-uncoupled loading after the completion of S phase. This G2 loading pathway of SpCENP-A may require Mis6, a constitutive centromere-binding protein that is also implicated in the Mad2-dependent spindle attachment checkpoint response. Here, we discuss the functional relationship between the flexible loading mechanism of CENP-A and the plasticity of centromere chromatin formation in fission yeast.
Chromosomal instability and human cancer
Authors: Michor Franziska
Published: May 2005

Genetic instability is a defining feature of human cancer. The main type of genetic instability, chromosomal instability (CIN), enhances the rate of gross chromosomal changes during cell division. CIN is brought about by mutations of CIN genes, i.e. genes that are involved in maintaining the genomic integrity of the cell. A major question in cancer genetics is whether genetic instability is a cause and hence a driving force of tumorigenesis. A mathematical framework for studying the somatic evolution of cancer sheds light onto the causal relations between CIN and human cancer.
Explaining the oligomerization properties of the spindle assembly checkpoint protein Mad2
Authors: DeAntoni Anna , Sala Valeria , Musacchio Andrea
Published: May 2005

Mad2 is an essential component of the spindle assembly checkpoint (SAC), a molecular device designed to coordinate anaphase onset with the completion of chromosome attachment to the spindle. Capture of chromosome by microtubules occur on protein scaffolds known as kinetochores. The SAC proteins are recruited to kinetochores in prometaphase where they generate a signal that halts anaphase until all sister chromatid pairs are bipolarly oriented. Mad2 is a subunit of the mitotic checkpoint complex, which is regarded as the effector of the spindle checkpoint. Its function is the sequestration of Cdc20, a protein required for progression into anaphase. The function of Mad2 in the checkpoint correlates with a dramatic conformational rearrangement of the Mad2 protein. Mad2 adopts a closed conformation (C-Mad2) when bound to Cdc20, and an open conformation (O-Mad2) when unbound to this ligand. Checkpoint activation promotes the conversion of O-Mad2 to Cdc20-bound C-Mad2. We show that this conversion requires a C-Mad2 template and we identify this in Mad1-bound Mad2. In our proposition, Mad1-bound C-Mad2 recruits O-Mad2 to kinetochores, stimulating Cdc20 capture, implying that O-Mad2 and C-Mad2 form dimers. We discuss Mad2 oligomerization and link our discoveries to previous observations related to Mad2 oligomerization.
Acute Effect of Gamma Irradiation on Gastric Acid Secretion and Gastric Mucosal Integrity in the Rat
Authors: Salam Omar M. E. Abdel , Hadajat Ihsan , Bayomy Ayman Ragab , El-Shinawy Siham , Arbid Mahmoud S.
Published: May 2005

The effect of 3- or 6-Gray (Gy) whole-body gamma irradiation on basal and stimulated gastric acid secretion was studied in pylorus-ligated rats. Different groups of rats were irradiated with a single 3- or 6-Gy fraction and examined 7 days after irradiation. Exposure to 3-Gy fraction led to marked increase in basal (nonstimulated) gastric acid output in the 4-h pylorus-ligated rat (47.5% compared with unirradiated controls). After exposure to 6 Gy, only 18.2% increase in gastric acid output was noted compared with unirradiated controls. Under pentagastrin or histamine stimulation, gastric acid secretion in those irradiated with 3- or 6-Gy fraction was markedly reduced compared to that of unirradiated controls. Exposure to 3- or 6-Gy gamma irradiation intensified the degree of gastric mucosal injury evoked by indomethacin or 50% ethanol in a dose-dependent manner. It is concluded that in the pylorus-ligated rat model, lower doses of gamma irradiation increase basal gastric acid secretion and impair the gastric mucosal barrier with marked increase in its permeability to H+following stimulation of acid secretion or exposure to barrier breakers. Exposure to irradiation is likely to result in failure of the parietal cell to respond to direct stimulation with histamine or pentagastrin.
Functional Recovery Following Pertrochanteric Hip Fractures Fixated with the Dynamic Hip Screw vs. the Percutaneous Compression Plate
Authors: Laufer Yocheved , Lahav Miriam , Lenger Reuben , Sprecher Elliot
Published: May 2005

The Dynamic Hip Screw (DHS) is currently the most frequently used implant for the treatment of pertrochanteric hip fractures. The Percutaneous Compression Plate (PCCP) is a recently developed, alternative device that involves minimal invasive surgery. The objective of the present study was to compare functional recovery following these two surgical procedures. A total of 76 consecutive elderly subjects (mean age and standard deviation, 80.6 ± 5.5) following pertrochanteric hip fracture fixation were evaluated prospectively. Functional recovery was assessed 3 and 12 weeks and 2 years following surgery. Differences between groups 3 weeks postsurgery were found only in pain level during ambulation and in the weight-bearing capability of the operated extremity, which were both in favor of the PCCP. By 3 months, both groups had improved in all measures, but did not reach their preinjury level of independence. However, the PCCP group ambulated with fewer assistive devices and demonstrated better recovery of basic activities of daily living (BADL). While the majority of the subjects from both groups ambulated independently 2 years postsurgery, the PCCP group exhibited less pain during ambulation, was more independent in ADL, and required fewer assistive devices for ambulation. To summarize, the PCCP presents enhanced short- and long-term recovery of functional abilities in comparison to DHS. However, given the limited number of patients, further studies are necessary to substantiate these results.
On The Possible Leakage of ET-RR1 Liquid Waste Tank: Hydrological and Migration Modes Studies
Authors: Mahmoud N. S. , EL-Hemamy S. T.
Published: May 2005

The first Egyptian (ET-RR1) research reactor has been in operation since 1961 at the Egyptian Atomic Energy Authority (EAEA) Inshas site. Therefore, at present, it faces a serious problem due to aging equipment, especially those directly in contact with the environment such as the underground settling tanks of nuclear and radioactive waste. The possible leakage of radionuclides from these aging tanks and their migration to the aquifer was studied using instantaneous release.This study was done based on the geological and hydrological characteristics of the site, which were obtained from the hydrogeological data of 25 wells previously drilled at the site of the reactor[1]. These data were used to calculate the trend of water levels, hydraulic gradient, and formulation of water table maps from 1993–2002. This information was utilized to determine water velocity in the unsaturated zone.Radionuclides released from the settling tank to the aquifer were screened according to the radionuclides that have high migration ability and high activity. The amount of fission and activation products of the burned fuels that contaminated the water content of the reactor pool were considered as 10% of the original spent fuel. The radionuclides considered in this case were H-3, Sr-90, Zr-93, Tc-99, Cd-113, Cs-135, Cs-137, Sm-151, Pu-238, Pu-240, Pu-241, and Am-241.The instantaneous release was analyzed by theoretical calculations, taking into consideration the migration mechanism of the various radionuclides through the soil space between the tank bottom and the aquifer. The migration mechanism through the unsaturated zone was considered depending on soil type, thickness of the unsaturated zone, water velocity, and other factors that are specific for each radionuclide, namely retardation factor, which is the function of the specific distribution coefficient of each radionuclide. This was considered collectively as delay time. Meanwhile, the mechanism of radionuclide migration during their passage in the water body of the aquifer was the main focus of this study.The degree of water pollution in the aquifer at a point of contact with the main water body of Ismailia Canal 1000 m from the reactor site was assessed for the instantaneous release by comparing the results obtained with the regulations of the standard limit of radionuclides in drinking water[2,3].
RNA-Guided RNA modification: functional organization of the archaeal H/ACA RNP
Authors: Baker Daniel L. , Youssef Osama A. , Chastkofsky Michael I.R. , Dy David A. , Terns Rebecca M. , Terns Michael P.
Published: May 2005

In eukaryotes and archaea, uridines in various RNAs are converted to pseudouridines by RNA-guided RNA modification complexes termed H/ACA RNPs. Guide RNAs within the complexes base-pair with target RNAs to direct modification of specific ribonucleotides. Cbf5, a protein component of the complex, likely catalyzes the modification. However, little is known about the organization of H/ACA RNPs and the roles of the multiple proteins thought to comprise the complexes. We have reconstituted functional archaeal H/ACA RNPs from recombinant components, defined the components necessary and sufficient for function, and determined the direct RNA–protein and protein–protein interactions that occur between the components. The results provide substantial insight into the functional organization of this RNP. The functional complex requires a guide RNA and each of four proteins: Cbf5, Gar1, L7Ae, and Nop10. Two proteins interact directly with the guide RNA: L7Ae and Cbf5. L7Ae does not interact with other H/ACA RNP proteins in the absence of the RNA. We have defined two novel functions for Cbf5. Cbf5 is the protein that specifically recognizes and binds H/ACA guide RNAs. In addition, Cbf5 recruits the two other essential proteins, Gar1 and Nop10, to the pseudouridylation guide complex.
Direct processing and presentation of antigen from malaria sporozoites by professional antigen‐presenting cells in the induction of CD8+ T‐cell responses
Authors: Plebanski Magdalena , Hannan Carolyn M , Behboudi Shahriar , Flanagan Katie L , Apostolopoulos Vasso , Sinden Robert E , Hill Adrian VS
Published: May 2005

Irradiated malaria sporozoites induce better protection than viable untreated sporozoites. We observed early differences between irradiated and viable untreated sporozoites in priming responses in vivo to a protective CD8 T‐cell epitope, pb9, of the circumsporozoite protein of Plasmodium berghei. Sporozoites were processed for MHC class I presentation by dendritic cells (DC) to prime pb9‐specific IFN‐γ‐producing CD8 T cells. DC pulsed with untreated and irradiated sporozoites were similarly capable of priming central memory T‐cell responses, detectable by the IFN‐γ cultured ELISPOT assay. However, irradiation significantly enhanced sporozoites’ ability to prime effector T‐cell responses detectable by the IFN‐γex vivo ELISPOT assay. Irradiation also enhanced the ability of splenic APC to process and present sporozoites in order to re‐stimulate pb9‐specific polyclonal and clonal T‐cell responses. Sporozoites did not stimulate T cells in the absence of APC. Over‐irradiation decreased the sporozoites’ T‐cell stimulating capacity in vitro at high parasite doses, which may indicate that an optimal irradiation dose is necessary to induce protective immunity by sporozoite inoculation. The induction of sporozoite‐specific CD8 T‐cell responses without the need for liver stage infection identifies a potentially important mechanism in the development of pre‐erythrocytic immunity.
Potential roles for short RNAs in lymphocytes
Authors: Chowdhury Dipanjan , Novina Carl D
Published: May 2005

RNA interference (RNAi) is an ancient and evolutionarily conserved process. In some eukaryotes, RNAi silences parasitic genetic elements. In plants, RNAi serves as an immune system against RNA viruses and transgenes and in worms, RNAi silences transposons. In mammals, RNAi has yet unknown functions. However, emerging roles for short RNAs and the factors that interact with them in other eukaryotes include chromatin modification, DNA deletion and DNA methylation, which may provide clues to the roles for short RNA function in mammals. For example, antigen receptor expression in lymphocytes is a highly regulated process and although much is known about chromatin modification and DNA deletion in the immune system, several molecular details of chromatin regulation remain elusive. This review compares emerging roles for short RNA function to processes required for antigen receptor expression in mammalian lymphocytes and predicts that short RNAs direct events required for successful lymphocyte‐restricted gene expression.
ADOPTIVE IMMUNOTHERAPY: METHODS AND PROTOCOLS
Authors: Khanna Rajiv
Published: May 2005

Immunology and Cell Biology (2005) 83, 313; doi:10.1111/j.1440‐1711.2005.01334.x
Expression systems and developments in plant‐made vaccines
Authors: Rigano M Manuela , Walmsley Amanda M
Published: May 2005

Delivery of vaccines to mucosal surfaces can elicit humoral and cell‐mediated responses of the mucosal and systemic immune systems, evoke less pain and discomfort than parenteral delivery, and eliminate needle‐associated risks. Transgenic plants are an ideal means by which to produce oral vaccines, as the rigid walls of the plant cell protect antigenic proteins from the acidic environment of the stomach, enabling intact antigen to reach the gut associated lymphoid tissue. In the past few years, new techniques (such as chloroplast transformation and food processing) have improved antigen concentration in transgenic plants. In addition, adjuvants and targeting proteins have increased the immunogenicity of mucosally administered plant‐made vaccines. These studies have moved plant‐made vaccines closer to the development phase.
Use of viral vectors for vaccine production in plants
Authors: Cañizares M Carmen , Nicholson Liz , Lomonossoff George P
Published: May 2005

The small size of plant viral genomes, the ease with which they can be manipulated, and the simplicity of the infection process is making the viral vectors an attractive alternative to the transgenic systems for the expression of foreign proteins in plants. One use of these virus expression systems is for vaccine production. There are two basic types of viral system that have been developed for the production of immunogenic peptides and proteins in plants: epitope presentation and polypeptide expression systems. In this review, we discuss advances made in this field.
The next 15 years: Taking plant‐made vaccines beyond proof of concept
Authors: Kirk Dwayne D , Webb Steven R
Published: May 2005

Significant potential advantages are associated with the production of vaccines in transgenic plants; however, no commercial product has emerged. An analysis of the strengths, weaknesses, opportunities and threats for plant‐made vaccine technology is provided. The use of this technology for human vaccines will require significant investment and developmental efforts that cannot be supported entirely by the academic sector and is not currently supported financially by industry. A focus on downstream aspects to define potential products, conduct of additional basic clinical testing, and the incorporation of multidisciplinary strategic planning would accelerate the potential for commercialization in this field. Estimates of production cost per dose and volume of production are highly variable for a model vaccine produced in transgenic tomato, and can be influenced by the optimization of many factors. Commercialization of plant‐made vaccine technology is likely to be led by the agricultural biotechnology sector rather than the pharmaceutical sector due to the disruptive nature of the technology and the complex intellectual property landscape. The next major milestones will be conduct of a phase II human clinical trial and demonstration of protection in humans. The achievement of these milestones would be accelerated by further basic investigation into mucosal immunity, the codevelopment of oral adjuvants, and the integration of quality control standards and good manufacturing practices for the production of preclinical and clinical batch materials.
Post‐fire vegetation dynamics in nutrient‐enriched and non‐enriched sclerophyll woodland
Authors: THOMSON VIVIEN P. , LEISHMAN MICHELLE R.
Published: May 2005

Abstract  Exotic plant invasions are a significant problem in urban bushland in Sydney, Australia. In low‐nutrient Hawkesbury Sandstone communities, invasive plants are often associated with urban run‐off and subsequent increases in soil nutrients, particularly phosphorus. Fire is an important aspect of community dynamics in Sydney vegetation, and is sometimes used in bush regeneration projects as a tool for weed control. This study addressed the question: ‘Are there differences in post‐fire resprouting and germination of native and exotic species in nutrient‐enriched communities, compared with communities not disturbed by nutrient enrichment?’ We found that in non‐enriched areas, few exotic species emerged, and those that did were unable to achieve the rapid growth that was seen in exotic plants in the nutrient‐enriched areas. Therefore, fire did not promote the invasion of exotic plants into areas that were not nutrient‐enriched. In nutrient‐enriched areas after fire, the diversity of native species was lower than in the non‐enriched areas. Some native species were able to survive and compete with the exotic species in terms of abundance, per cent cover and plant height. However, these successful species were a different suite of natives to those commonly found in the non‐enriched areas. We suggest that although fire can be a useful tool for short‐term removal of exotic plant biomass from nutrient‐enriched areas, it does not promote establishment of native species that were not already present.
Ecosystem wicks: Woodland trees enhance water infiltration in a fragmented agricultural landscape in eastern Australia
Authors: ELDRIDGE DAVID J. , FREUDENBERGER DAVID
Published: May 2005

Abstract Since European settlement,Eucalyptusbox woodlands have been substantially modified by agricultural practices, and in many areas in southern Australia are now restricted to scattered or clumped trees. We report here on a study to examine the impact of trees on water flow (infiltration) in an agricultural landscape with substantial areas of extant native vegetation. We examined infiltration through coarse‐ and fine‐textured soils within four landscape strata, the zones belowEucalyptus melliodoraandCallitris glaucophyllacanopies, the intertree zone dominated by perennial grasses and a landscape homogenized by cultivation and dominated by annual crops. We measured sorptivity, the early phase of water flow, and steady‐state infiltration with disc permeameters at two supply potentials. These different potentials enabled us to separate infiltration into (i) flow through large (biopores) and small pores and (ii) flow through small pores only where biopores are prevented from conducting water. On the fine‐textured soils, both sorptivity and steady‐state infiltration were significantly greater (approximately fivefold) under the timbered strata compared with the grassy slopes or cultivation. Differences were attributable to the greater proportion of macropores below the tree canopies compared with the nontimbered strata. The lack of a significant difference on the coarse‐textured soils, despite their macropore status, was attributed to differences in surface litter and plant cover, which would maintain continuous macropores at the surface and thus conduct large amounts of water. The tendency of slopes covered by cryptogamic crusts and grasses to shed run‐off and for the trees to absorb substantial quantities of water reinforced the important ecological service provided by trees, which moderates large run‐off events and captures small amounts of water leaking from the grassy patches. In the absence of these ‘ecosystem wicks’, run‐off would find its way into regional groundwater and contribute to rising salinity.
Lower urinary tract symptoms suggestive of benign prostatic hyperplasia: latest update on α1‐adrenoceptor antagonists
Authors: Milani Shirin , Djavan Bob
Published: May 2005

An update of a systematic review of α1‐adrenoceptor (AR) antagonists in the treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) showed that these agents have comparable efficacy. The total symptom score is improved by 30–45% and maximum urinary flow rate by 15–30% vs baseline. α1‐AR antagonists that can be started at their therapeutic dose have a more rapid onset of action than α1‐AR antagonists that have to be titrated. α1‐AR antagonists can be differentiated according to their tolerability. Alfuzosin (especially the 10 mg once daily dose) and tamsulosin (especially the 0.4 mg once daily dose) are better tolerated than doxazosin and terazosin. However, alfuzosin might induce more cardiovascular adverse events (AEs) in the elderly and/or patients with cardiovascular comorbidity and/or comedication. Tamsulosin tends to interfere less with blood pressure regulation and induce less vasodilatory AEs than alfuzosin, especially in the elderly, and is well tolerated in patients with cardiovascular comorbidity and/or comedication. Cardiovascular AEs might lead to potentially serious complications such as falls, fractures and institutionalization. Abnormal ejaculation has mainly been reported in placebo‐controlled trials with tamsulosin but in direct comparative trials its rate with tamsulosin 0.4 mg was similar to, or only slightly higher than, the rate with alfuzosin. In addition, abnormal ejaculation is not reported as bothersome by the patient or associated with serious complications. It can be concluded that an α1‐AR antagonist with a low potential to interfere with blood pressure regulation and to induce cardiovascular AEs, also in patients with cardiovascular comorbidity and/or comedication, can be considered a first‐choice treatment option in LUTS/BPH.
Treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia: sexual function
Authors: Lowe Franklin C.
Published: May 2005

Lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH), and sexual dysfunction, are common, highly bothersome conditions in older men, and the prevalence of both disorders increases with age. Sexual dysfunction manifests mainly as erectile dysfunction (ED), ejaculatory disorders, or decreased libido/hypoactive sexual desire (HSD). Whereas both reduced rigidity and reduced ejaculate volume are highly prevalent in ageing men, reduced rigidity and pain on ejaculation are considered to be most bothersome. Sexual dysfunction is much more prevalent in patients with LUTS/BPH than in men with no LUTS/BPH, even after controlling for confounding variables such as age or comorbidities. Hence LUTS/BPH is considered an independent risk factor for sexual dysfunction. Whether this is because of a common underlying pathology, or whether the considerable bother associated with LUTS/BPH leads to reduced sexual functioning, remains to be elucidated. Despite a decline in the frequency of sexual intercourse, as well as in overall sexual functioning, most ageing men report regular sexual activity and consider their sex life as an important dimension of their quality of life (QoL). However, most patients with LUTS/BPH experience a negative effect of their LUTS on their sex life. Hence, treatment of LUTS/BPH should aim to at least maintain or, if possible, improve sexual function. Current medical treatment of LUTS/BPH consists of monotherapy with α1‐adrenoceptor (AR) antagonists, 5α‐reductase inhibitors (RIs) or a combination of these. Whereas 5α‐RIs increase the risk of ED, ejaculatory disorders and HSD, α1‐AR antagonists can induce ejaculatory disorders, but do not provoke HSD or ED. Combined therapy carries the cumulative risk for sexual dysfunction associated with either type of drug. As already indicated, ED is generally perceived as more bothersome than ejaculatory disorders. In addition, α1‐AR antagonists slightly improve overall sexual function, possibly by increasing blood flow in the penis through α1‐AR blockade and/or to an increased overall QoL from the relief of LUTS. It can be concluded that α1‐AR antagonists constitute a first‐line therapy for LUTS/BPH because they combine good treatment efficacy with very few adverse effects on sexual function.
Chronic Cytomegalovirus Infection and Inflammation Are Associated with Prevalent Frailty in Community‐Dwelling Older Women
Authors: Schmaltz Heidi N. , Fried Linda P. , Xue Qian‐Li , Walston Jeremy , Leng Sean X. , Semba Richard D.
Published: May 2005

Objectives: To evaluate the association between asymptomatic chronic cytomegalovirus (CMV) infection and the frailty syndrome and to assess whether inflammation modifies this association.

Design: Cross‐sectional analysis.

Setting: Women's Health and Aging Study I & II, Baltimore, Maryland.

Participants: Seven hundred twenty‐four community‐dwelling women aged 70 to 79 with baseline measures of CMV, interleukin‐6 (IL‐6), and frailty status.

Measurements: CMV serology and IL‐6 concentrations were measured using enzyme‐linked immunosorbent assay. Frailty status was based on previously validated criteria: unintentional weight loss, weak grip strength, exhaustion, slow walking speed, and low level of activity. Frail women had three or more of the five components, prefrail women had one or two components, and women who were not frail had none of the components. Multinomial logistic regression adjusted for potential confounders.

Results: Eighty‐seven percent of women were CMV seropositive, an indication of chronic infection. CMV was associated with prevalent frailty, adjusting for age, smoking history, elevated body mass index, diabetes mellitus, and congestive heart failure (CMV frail adjusted odds ratio (AOR)=3.2, P=.03; CMV prefrail AOR=1.5, P=.18). IL‐6 interacted with CMV, significantly increasing the magnitude of this association (CMV positive and low IL‐6 frail AOR=1.5, P=.53; CMV positive and high IL‐6 frail AOR=20.3, P=.007; CMV positive and low IL‐6 prefrail AOR=0.9, P=.73; CMV positive and high IL‐6 prefrail AOR=5.5, P=.001).

Conclusion: Chronic CMV infection is associated with prevalent frailty, a state with increased morbidity and mortality in older adults; inflammation enhances this effect. Further prospective studies are needed to establish a causal relationship between CMV, inflammation, and frailty.
Type and Intensity of Activity and Risk of Mobility Limitation: The Mediating Role of Muscle Parameters
Authors: Visser Marjolein , Simonsick Eleanor M. , Colbert Lisa H. , Brach Jennifer , Rubin Susan M. , Kritchevsky Stephen B. , Newman Anne B. , Harris Tamara B. ,   for the Health ABC Study
Published: May 2005

Objectives: To investigate the association between different types of physical activity behavior and incident mobility limitation in older men and women and to examine whether muscle parameters mediate these associations.

Design: Cohort study with 4.5‐year follow‐up.

Setting: Metropolitan areas surrounding Pittsburgh, Pennsylvania, and Memphis, Tennessee. A random sample of white Medicare beneficiaries and all age‐eligible blacks.

Participants: Three thousand seventy‐five black and white men and women aged 70 to 79 with no self‐reported difficulty walking one‐quarter of a mile or climbing 10 steps, enrolled in the Health, Aging and Body Composition (Health ABC) Study.

Measurements: Participants were classified as exercisers (reporting ≥1,000 kcal/wk of exercise activity), lifestyle active (reporting <1,000 kcal/wk of exercise activity and ≥2,719 kcal/wk of total physical activity), or inactive (reporting <1,000 kcal/wk of exercise activity and <2,719 kcal/wk of total physical activity). The study outcome, incident mobility limitation, was defined as two consecutive, semiannual self‐reports of any difficulty walking one quarter of a mile or climbing 10 steps. Thigh muscle area, thigh muscle attenuation (a marker of fat infiltration in muscle), appendicular lean soft tissue mass, and isokinetic knee extensor strength were examined as potential mediators.

Results: Over 4.5 years, 34.3% of men and 47.4% of women developed mobility limitation. Inactive persons had twice the risk of incident mobility limitation as exercisers (hazard ratio (HR)=2.08, 95% confidence interval (CI)=1.60−2.70, for men, HR=1.98, 95% CI=1.51−2.60, for women). Lifestyle‐active men and women had an intermediate risk (HR=1.47 and 1.44, respectively). For the lifestyle active and inactive, absence of walking activity conferred an additional risk of mobility limitation. Muscle parameters did not mediate the relationship between physical activity and mobility limitation, except for knee extensor strength in men.

Conclusion: Exercise and an active lifestyle that includes walking protect against mobility loss in older men and women. Activity effects on muscle parameters do not explain this association.
Reduced Mammographic Screening May Explain Declines in Breast Carcinoma in Older Women
Authors: Kaplan Robert M. , Saltzstein Sidney L.
Published: May 2005

Objectives: To examine whether declines in breast cancer in the oldest‐old women correspond with declines in the use of cancer testing.

Design: Cross‐sectional evaluation of three databases.

Setting: Public access data.

Participants: Cases recorded in the California Registry and the Surveillance, Epidemiology, and End Results Program between 1988 and 1997. The study also included respondents to the 2002 Centers for Disease Control and Prevention Behavioral Risk Factor Surveillance System.

Measurements: Cancer incidence and self‐reported mammography within the previous 2 years.

Results: Most previous analyses have combined all individuals aged 75, 80, or 85 and older. Creating separate categories for age ranges 85 to 89, 90 to 94, 95 to 99, and 100 and older suggests different incidence patterns for a variety of cancers, including mammary carcinoma in situ (CIS). Between the ages of 40 and 74, there is a significant rise in CIS. Beginning at age 75, there is a significant decline in CIS through the highest age categories. The use of mammographic screening increases between the ages of 40 and 60. Beginning at age 75, there is a significant decline in the use of mammography that parallels the decline in incident cases of CIS.

Conclusion: There may be a substantial reservoir of undiagnosed CIS in the population. Surveillance bias might explain the decreasing incidence of CIS with advancing age in the oldest age groups. Autopsy studies are needed to estimate the true prevalence of CIS in older women.
The Care of Patients with Dementia: A Modern Jewish Ethical Perspective
Authors: Jotkowitz Alan B. , Clarfield A. Mark , Glick Shimon
Published: May 2005

Patients with dementia and their families can face many difficult and agonizing ethical dilemmas over the course of the illness. An awareness of the Jewish ethical response to some of these issues can help clinicians in treating patients of the Jewish faith and also serve as an example of how one ethical system addresses these questions. The Jewish response is grounded in a profound respect and value for human life in all its forms and man's responsibility to preserve it, but Judaism rejects unproven therapies and recognizes the limitations of modern medicine. Jewish law also codifies normative obligations that children have toward their elderly parents. With these principles in the forefront, this article analyzes a Jewish ethical response to various problems in the care of the demented patient such as truth telling, transfer to a nursing home, artificial nutrition, and end‐of‐life care, taking into account modern concepts of the doctor‐patient relationship and ancient Jewish tradition.