bluuebunny/crossref_metadata_2025 huggingface dataset:
Screening for Partial Conjunction Hypotheses
Authors: Benjamini Yoav , Heller Ruth
Published: February 2008

Summary We consider the problem of testing for partial conjunction of hypothesis, which argues that at least u out of n tested hypotheses are false. It offers an in‐between approach to the testing of the conjunction of null hypotheses against the alternative that at least one is not, and the testing of the disjunction of null hypotheses against the alternative that all hypotheses are not null. We suggest powerful test statistics for testing such a partial conjunction hypothesis that are valid under dependence between the test statistics as well as under independence. We then address the problem of testing many partial conjunction hypotheses simultaneously using the false discovery rate (FDR) approach. We prove that if the FDR controlling procedure in Benjamini and Hochberg (1995, Journal of the Royal Statistical Society, Series B 57, 289–300) is used for this purpose the FDR is controlled under various dependency structures. Moreover, we can screen at all levels simultaneously in order to display the findings on a superimposed map and still control an appropriate FDR measure. We apply the method to examples from microarray analysis and functional magnetic resonance imaging (fMRI), two application areas where the need for partial conjunction analysis has been identified.
The influence of blood volume‐controlled ultrafiltration on hemodynamic stability and quality of life
Authors: SENTVELD Bas , VAN DEN BRINK Mandy , BRULEZ Harald F.H. , POTTER VAN LOON Bert‐Jan , WEIJMER Marcel C. , SIEGERT Carl E.H.
Published: February 2008

Dialysis hypotension occurs frequently and is associated with increased morbidity, mortality, and may influence quality of life. We investigated the influence of blood volume (BV)‐controlled ultrafiltration on hemodynamic stability and quality of life in a prospective multiple crossover study. Nineteen patients were consecutively treated with standard hemodialysis (HD), BV‐controlled ultrafiltration, and again with standard ultrafiltration during 3‐week phases, during which different hemodynamic parameters, ultrafiltrate quantities, dry weight, and quality of life were measured. Blood volume‐controlled ultrafiltration resulted in increased hemodynamic stability: systolic blood pressure was significantly higher after treatment with BV‐controlled HD compared with both standard treatments (p=0.018 and 0.043, respectively). Also, systolic blood pressure reduction, as a measure of blood pressure stability, was significantly smaller during the BV‐controlled phase (−3.9 mmHg) compared with both standard phases (−13.7 and −11.0 mmHg): p=0.003 and 0.035, respectively. No difference was found in the occurrence of large decreases of blood pressure (>30 mmHg), decreases below 90 mmHg systolic pressure, or subjective complaints during treatment or after treatment between both treatment modalities. During the course of the study, the dry weight decreased significantly from mean 73.3 to mean 70.9 kg, and the amount of ultrafiltrate was significantly larger using BV‐controlled HD compared with standard treatment (mean 2407 vs. mean 2266 mL; p=0.035). Quality of life, measured by visual analog scales (VAS), showed discrete but no consistent differences between study phases. We conclude that BV‐controlled HD increases hemodynamic stability and ultrafiltrate amount compared with a standard treatment. No consistent change in quality of life is found between both treatment modalities.
Phase Morphology in Electrospun Zirconia Microfibers
Authors: Davies Erin , Lowe Adrian , Sterns Meta , Fujihara Kazutoshi , Ramakrishna Seeram
Published: February 2008

Electrospinning of sol–gels has been used to produce zirconium‐doped polymer microfibers from zirconyl chloride and poly(vinylpyrollidone) precursors. Calcination of these structures between temperatures of 370° and 930°C resulted in the formation of zirconia nanograined microfibers whose diameters ranged from 1200 to 800 nm at the higher temperatures and whose average grain size ranged from 9 to 33 nm. X‐ray diffraction analysis revealed varying amounts of monoclinic and tetragonal zirconia present in the fibers and established how this varied with calcination temperature and time. The tetragonal phase was shown to be unstable and disappeared on heating the material beyond around 750°C. The amount of zirconia yielded from the precursor material was measured and was found to be consistently greater than the theoretical yield. Average grain size within the microfibers increased with increasing calcination temperature and is effectively doubled when a 10 kPa pressure was applied. The effect of pressure also results in the creation of new crystal structures within the nanofibers and, as with traditional zirconia processing, the addition of impurity ions was found to stabilize the tetragonal phase.
A Silicon Carbonitride Ceramic with Anomalously High Piezoresistivity
Authors: Zhang Ligong , Wang Yansong , Wei Yun , Xu Weixing , Fang Danjie , Zhai Lei , Lin Kuo‐Chi , An Linan
Published: February 2008

The piezoresistive behavior of a silicon carbonitride ceramic derived from a polymer precursor is investigated under a uniaxial compressive loading condition. The electric conductivity has been measured as a function of the applied stress along both longitudinal and transverse directions. The gauge factor of the materials was then calculated from the data at different stress levels. The results show that the material exhibits an extremely high piezoresistive coefficient along both directions, ranging from 1000 to 4000, which are much higher than any existing ceramic material. The results also reveal that the gauge factor decreases significantly with increasing applied stress. A theoretical model based on the tunneling–percolation mechanism has been developed to explain the stress dependence of the gauge factor. The unique piezoresistive behavior is attributed to the unique self‐assembled nanodomain structure of the material.
Control of Functional Microstructure in WO3‐Doped Bi4Ti3O12 Ceramics
Authors: Jardiel Teresa , De La Rubia Miguel Angel , Peiteado Marco
Published: February 2008

Bi4Ti3O12 (BIT) coprecipitated powders sinter in the presence of a transitory liquid phase, which strongly enhances the diffusion of matter and also the anisotropic growth of BIT grains. However, by coating the surface of BIT particles with WO3 the aspect ratio of the platelets can be controlled. This, in addition to the donor effect of tungsten, finally leads to a decrease of the electrical conductivity of these ferroelectric ceramics.
Energetics of La2O3–HfO2–SiO2 Glasses
Authors: Morcos Riham Michelle , Tangeman Jean , Ushakov Sergey , Navrotsky Alexandra
Published: February 2008

A series of La2O3–HfO2–SiO2 glasses, approximately along the join 0.73SiO2–0.27(xHfO2–(1−x)La2O3), 0<x<0.3), was prepared using containerless processing techniques (aerodynamic levitation combined with laser heating in oxygen). The enthalpy of formation and enthalpy of vitrification at 25°C were obtained from drop solution calorimetry of these glasses and appropriate crystalline compounds in a molten lead borate (2PbO–B2O3) solvent at 702°C. The enthalpy of formation from crystalline oxides was exothermic and became less exothermic with increasing HfO2 content. Heat contents were measured by transposed temperature drop calorimetry and depended linearly on the HfO2 content. Differential scanning calorimetry showed that both the onset glass transition and the onset crystallization temperature of these glasses increased with increasing HfO2 content. Upon slow cooling in air, the glasses crystallized to a mixture of baddeleyite, cristobalite, lanthanum disilicate, and hafnon.
Validation Set Correlates of Anogenital Injury after Sexual Assault
Authors: Drocton Peter , Sachs Carolyn , Chu Lawrence , Wheeler Malinda
Published: February 2008

Objectives:  Forensic investigators remain unsure exactly why some sexual assault victims display acute injury while others do not. This investigation explores potential reasons for these differential findings among female victims.

Methods:  This cross‐sectional analysis examined data from consecutive female sexual assault victims, at least 12 years old, who agreed to a forensic exam between November 1, 2002, and November 30, 2006. Exams utilized colposcopy, anoscopy, macrodigital imaging, and toluidine blue dye to delineate anogenital injury (AGI), which was defined as the presence of recorded anogenital abrasions, tears, or ecchymosis. Demographic variables of the victim, including sexual experience and reproductive parity, and assault characteristics were recorded in the database for bivariate and multivariate analysis with AGI.

Results:  Forty‐nine percent of the initial 3,356 patients displayed AGI. Of this total, 2,879 cases included complete data for all variables and were included in the multivariate logistic regression model. A statistically significant increased risk for AGI was noted with: educational status (odds ratio [OR] 1.53, 95% CI = 1.25 to 1.87); vaginal or attempted penetration using penis (OR 2.29, 95% CI = 1.74 to 3.01), finger (OR 1.61, 95% CI = 1.88 to 1.94), or object (OR 3.19, 95% CI = 1.52 to 6.68); anal–penile penetration (OR 2.00, 95% CI = 1.57 to 2.54); alcohol involvement (OR 1.25, 95% CI = 1.04 to 1.50); and virgin status of victim (OR 1.38, 95% CI = 1.11 to 1.71). Victims were less likely to display AGI with a longer postcoital interval (OR 0.50, 95% CI = 0.39 to 0.65) and increased parity (OR 0.76, 95% CI = 0.57 to 0.99).

Conclusions:  Approximately half the patients displayed AGI. This rate is higher than earlier studies, but consistent with current investigations utilizing similar injury detection methods. The correlates of injury found reinforce the findings of prior studies, while prompting questions for future study.
RNA interference‐mediated silencing of the polo‐like kinase 1 gene enhances chemosensitivity to gemcitabine in pancreatic adenocarcinoma cells
Authors: Yu C. , Zhang X. , Sun G. , Guo X. , Li H. , You Y. , Jacobs J. L. , Gardner K. , Yuan D. , Xu Z. , Du Q. , Dai C. , Qian Z. , Jiang K. , Zhu Y. , Li Q. Q. , Miao Y.
Published: February 2008

Gemcitabine is the first‐line chemotherapeutic agent for advanced adenocarcinoma of the pancreas; however, chemoresistance to gemcitabine remains a major cause of failure for the clinical treatment of this disease. Polo‐like kinase 1 (Plk‐1) is highly expressed in pancreatic cancer cell lines and pancreatic tumour tissues, and is involved in a wide variety of cell cycle processes. Nevertheless, its biological role and implication for gemcitabine resistance are not clearly defined. In this study, we used RNA‐interference (RNAi)‐mediated depletion of Plk‐1 to determine its potential for sensitizing pancreatic tumour cells to gemcitabine. We showed that the level of Plk‐1 protein was correlated significantly with gemcitabine resistance in human pancreatic adenocarcinoma cells and that overexpression of Plk‐1 reduced sensitivity to gemcitabine in these cells. In addition, small interfering RNA (siRNA)‐mediated knockdown of Plk‐1 caused cell cycle arrest at G2/M and the reduction of cellular proliferation. More importantly, the treatment of pancreatic cancer cells with Plk‐1 siRNA followed by exposure to gemcitabine dramatically decreased cell viability and increased cellular apoptosis, as compared with treatment with either agent alone. These observations indicate that down‐regulation of Plk‐1 expression by RNAi enhances gemcitabine sensitivity and increases gemcitabine cytotoxicity in pancreatic tumour cells. This is the first demonstration that the combination of Plk‐1 gene therapy and gemcitabine chemotherapy has synergistic anti‐tumour activity against pancreatic carcinoma in vitro. This combination treatment warrants further investigation as an effective therapeutic regimen for patients with resistant pancreatic cancer and other tumours.
Paralog of the formylglycine‐generating enzyme – retention in the endoplasmic reticulum by canonical and noncanonical signals
Authors: Gande Santosh Lakshmi , Mariappan Malaiyalam , Schmidt Bernhard , Pringle Thomas H. , von Figura Kurt , Dierks Thomas
Published: February 2008

Formylglycine‐generating enzyme (FGE) catalyzes in newly synthesized sulfatases the oxidation of a specific cysteine residue to formylglycine, which is the catalytic residue required for sulfate ester hydrolysis. This post‐translational modification occurs in the endoplasmic reticulum (ER), and is an essential step in the biogenesis of this enzyme family. A paralog of FGE (pFGE) also localizes to the ER. It shares many properties with FGE, but lacks formylglycine‐generating activity. There is evidence that FGE and pFGE act in concert, possibly by forming complexes with sulfatases and one another. Here we show that human pFGE, but not FGE, is retained in the ER through its C‐terminal tetrapeptide PGEL, a noncanonical variant of the classic KDEL ER‐retention signal. Surprisingly, PGEL, although having two nonconsensus residues (PG), confers efficient ER retention when fused to a secretory protein. Inducible coexpression of pFGE at different levels in FGE‐expressing cells did not significantly influence the kinetics of FGE secretion, suggesting that pFGE is not a retention factor for FGE in vivo. PGEL is accessible at the surface of the pFGE structure. It is found in 21 mammalian species with available pFGE sequences. Other species carry either canonical signals (eight mammals and 26 nonmammals) or different noncanonical variants (six mammals and six nonmammals). Among the latter, SGEL was tested and found to also confer ER retention. Although evolutionarily conserved for mammalian pFGE, the PGEL signal is found only in one further human protein entering the ER. Its consequences for KDEL receptor‐mediated ER retrieval and benefit for pFGE functionality remain to be fully resolved.
Active γ‐secretase is localized to detergent‐resistant membranes in human brain
Authors: Hur Ji‐Yeun , Welander Hedvig , Behbahani Homira , Aoki Mikio , Frånberg Jenny , Winblad Bengt , Frykman Susanne , Tjernberg Lars O.
Published: February 2008

Several lines of evidence suggest that polymerization of the amyloid β‐peptide (Aβ) into amyloid plaques is a pathogenic event in Alzheimer’s disease (AD). Aβ is produced from the amyloid precursor protein as the result of sequential proteolytic cleavages by β‐secretase and γ‐secretase, and it has been suggested that these enzymes could be targets for treatment of AD. γ‐Secretase is an aspartyl protease complex, containing at least four transmembrane proteins. Studies in cell lines have shown that γ‐secretase is partially localized to lipid rafts, which are detergent‐resistant membrane microdomains enriched in cholesterol and sphingolipids. Here, we studied γ‐secretase in detergent‐resistant membranes (DRMs) prepared from human brain. DRMs prepared in the mild detergent CHAPSO and isolated by sucrose gradient centrifugation were enriched in γ‐secretase components and activity. The DRM fraction was subjected to size‐exclusion chromatography in CHAPSO, and all of the γ‐secretase components and a lipid raft marker were found in the void volume (> 2000 kDa). Co‐immunoprecipitation studies further supported the notion that the γ‐secretase components are associated even at high concentrations of CHAPSO. Preparations from rat brain gave similar results and showed a postmortem time‐dependent decline in γ‐secretase activity, suggesting that DRMs from fresh rat brain may be useful for γ‐secretase activity studies. Finally, confocal microscopy showed co‐localization of γ‐secretase components and a lipid raft marker in thin sections of human brain. We conclude that the active γ‐secretase complex is localized to lipid rafts in human brain.
Bereavement Therapy With Adolescents: Facilitating a Process of Spiritual Growth
Authors: Leighton Sharon
Published: February 2008

TOPIC:  Bereavement therapy as a catalyst for spiritual growth.

PURPOSE:  This study aims to review the literature and reflect on the bereavement therapy undertaken with two adolescents who had been bereaved during childhood.

SOURCES:  Research articles and books identified through a combination of electronic and manual searches.

CONCLUSIONS:  It would appear that grief therapy could facilitate spiritual growth in such circumstances. Further in‐depth studies are required to identify how typical or atypical this experience is, and to contribute to the evidence base for working with bereaved children and adolescents.
Comparative QSAR Study on Para‐substituted Aromatic Sulphonamides as CAII Inhibitors: Information versus Topological (Distance‐Based and Connectivity) Indices
Authors: Singh Jyoti , Shaik Basheerulla , Singh Shalini , Agrawal Vijay K. , Khadikar Padmakar V. , Deeb Omar , Supuran Claudiu T.
Published: February 2008

Comparative quantitative structure–activity relationship studies on para‐substituted aromatic sulphonamides carbonic anhydrase II (CAII) inhibitors are reported in this paper. The study is made utilizing (i) information indices along; (ii) distance‐based and connectivity indices and (iii) combination of information, distance‐based and connectivity type topological indices. The study has shown that distance‐based and connectivity type indices are superior for modelling, monitoring and estimating CAII inhibition. The results are critically discussed using a variety of statistical parameters. Our results show that starting from the mono‐parametric regression itself, our results are superior: Furthermore, our methodology allowed carrying out much higher‐parametric regressions, yielding a nine‐parametric model with R2 as high as 0.8375. The eight‐parametric regression, gave R2 = 0.8343. As there is not much difference, we have considered the eight‐parametric regression the best.
Physical Properties and Consumer Liking of Cookies Prepared by Replacing Sucrose with Tagatose
Authors: Taylor T.P. , Fasina O. , Bell L.N.
Published: February 2008

ABSTRACT:  The objective of this study was to investigate the suitability of tagatose, a minimally absorbed prebiotic monosaccharide, as a replacement for sucrose in cookies. A sucrose‐containing cookie recipe was prepared as the control. Sucrose was replaced with tagatose at various levels ranging from 25% to 100%. Cookies containing fructose were also prepared for comparison due to the structural similarities between tagatose and fructose. The rheological properties of the dough were measured using texture profile analysis. The baked cookies were evaluated for spread, color, and hardness. For tagatose‐containing cookies, the extent of likeness was evaluated by 53 untrained panelists using a 9‐point hedonic scale. When sucrose was replaced by tagatose, doughs with similar rheological properties to the control resulted. The tagatose‐containing cookies were harder and darker with a lower spread than the control. Sensory data indicated that panelists liked the brown color of the 100% tagatose cookies better than the control, but disliked their sweetness. Overall likeness scores of the control and cookies made by replacing half of the sucrose with tagatose were the same. Tagatose appears to be suitable as a partial replacer for sucrose in cookies based on similar dough properties, cookie properties, and likeness scores. Using tagatose to replace sucrose in foods would reduce the amount of metabolizeable sugars in the diet as well as provide the desirable prebiotic effect.
Vaccination of feral pigs (Sus scrofa) using iophenoxic acid as a simulated vaccine
Authors: Cowled BD , Lapidge SJ , Smith Ml , Staples LD
Published: February 2008

Objectives  To develop an encapsulation method for delivery of vaccines to feral pigs, and quantify the effect of iophenoxic acid on captive feral pig blood iodine concentrations to assist in investigation of factors affecting vaccine uptake.

Design and methods  Feral pigs were administered iophenoxic acid by oral gavage, and consumption was assessed for different encapsulation methods in baits. Blood iodine concentrations were monitored for eight days after consumption. The relationship between dose rate, time since dosing and blood iodine concentration was assessed for gavaged and baited captive feral pigs. Wild feral pigs were baited with PIGOUT® baits containing 20 mg of encapsulated iophenoxic acid to simulate a vaccination program. Using knowledge from the pen studies, bait uptake and factors affecting bait uptake were investigated.

Results  Bait‐delivered iophenoxic acid led to variable and inconsistent changes in blood iodine concentrations, in contrast to pigs receiving iophenoxic acid by gavage. This precluded accurate assessment of the quantity consumed, but still allowed a conservative determination of bait uptake. Iophenoxic acid in smaller capsules was consumed readily. Increasing baiting intensity appeared to increase bait uptake by wild feral pigs, and pigs of varying sexes, ages and weights appeared equally likely to consume baits.

Conclusions  Encapsulated liquids can be delivered to feral pigs within baits, should the need to vaccinate feral pigs for fertility or disease management arise. High baiting intensities may be required.
ABSORPTION CHANGES IN BACTERIAL CHROMATOPHORES‐II. A NEW CHLOROPHYLL‐LIKE PIGMENT FROM THE OXIDATION OF CHROMATQPHORES FROM RHODOSPIRILLUM RUBRUM
Authors: Gould Edwin S. , Kuntz Irwin D. , Calvin Melvin
Published: February 2008

Abstract— Evidence is presented which points to (at least) two bound forms of bacteriochlor‐ophyll present in chromatophores of Rhodospirillum rubrum, both of them readily converted to unbound bacteriochlorophyll (abs. max 770 mμ) when the chromatophores are extracted with acetone or ethanol. Controlled oxidation of the chromatophores with Ir(IV) or with Zn (II) and ferricyanide preferentially destroys the more strongly absorbing pigment (abs. max 880 mμ) but brings about only a slight decrease in the magnitude of the photoinduced absorption changes at 810 and 792 mμ. Such oxidations yield a new pigment, absorbing at 715 mμ in the aqueous preparation and, more strongly, at 680–684 mu when the pigment is extracted into organic solvents. This pigment is formed irreversibly and is therefore different from the material formed by photooxidation of chromatophores. Its visible spectrum and the spectrum of the material formed from it by acidification suggest that it is a chlorophyll‐like substance, possibly derived from bacteriochlorophyll by (two‐electron) oxidation of one of the dihydropyrrole rings to a pyrrole ring. Directions are given for separation of this pigment from other colored compounds present in the oxidation mixtures.
KINETIC STUDIES OF THE TWO LIGHT REACTIONS IN PHOTOSYNTHESIS
Authors: Kuntz I. D. , Calvin Melvin
Published: February 2008

Abstract— The decay kinetics of the photo‐induced absorbance changes in red and green algae are very sensitive to the wavelength of the actinic light. A four to tenfold increase in half‐decay time is noted in going from short wavelength (550–650 mμ) to long wavelength (> 700 mμ) excitation. The slow decay rates produced by long wavelength light can be enhanced with a steady background of short wavelength light. A relationship between initial decay rates and O2 evolution rates is described. This relationship allows a direct correspondence between these spectroscopic studies and the ‘red‐drop’ and ‘enhancement’ experiments of Emerson.
MORPHOGENETIC RESPONSES OF EPICOTYL HOOK, PRIMARY LEAVES AND FIRST INTERNODE OF CITRUS SEEDLINGS TO IRRADTANCE*
Authors: Monselise S. P. , Kadman‐Zahavi Avishag
Published: February 2008

Abstract— Dark germinated citrus seeds produce a characteristic epicotyl hook which opens in white light.

The effects of white, red and far red irradiation, in different combinations on the opening of hooks, the increase in length of primary leaves and the reduction in length of epicotyl have been studied. Broadly speaking, morphogenetic effects of light are similar to those usual for annual plants.

One single red cycle coming after a long period of intermittent far red seems to be more effective than coming after a long period of darkness. It is also at least as effective as a long period of intermittent red irradiance. These features are of interest and deserve further study.

Elongation of leaves and opening of hooks are correlated when treatment means are considered, but not in individual seedlings, possibly indicating independence of these two effects of radiation.
EFFECT OF AMINO ACIDS ON THYMINE DIMERIZATION*
Authors: Balis M. Earl
Published: February 2008

Abstract— The effect of several amines on the U.V. catalyzed dimerization of thymine was determined at 25† and — 20†. Most amino acids and EDTA had no effect. Histidine, phosphoserine and phosphoethanolamine increased the net yield of dimer at 25†, but decreased the yield at — 20†. Histidine stimulates the cleavage of dilute solutions of thymine dimer at 25†. It is suggested that these compounds might prevent the orientation of thymine molecules necessary for their photoactivation. These findings stress the potential role of the surrounding medium in photoreactions involving DNA both in vitro and in vivo.

Attempts to cause photodimerization of thymine with proflavin as pholoactivator were unsuccessful. This is contrasted with the observed effects of this dye on DNA which mimic those of U.V.
LIGHT REACTION SYSTEMS IN CYANOPHYCEAE*
Authors: Nultsch W.
Published: February 2008

Abstract— In the blue green algae, Phormidium uncinatum and Ph. autumnale, movement in the dark is arrested by 2 × 10‐‐4 M DCPIP†, whereas photokinesis, i.e. the acceleration of the movement by light, is not markedly impaired. Thus at this concentration movement occurs in the light, but not in the dark. Obviously, the dark movement is coupled with oxidative phosphoiylation and the inhibitory effect of DCPLP is probably due to trapping of electrons from the cytochrome chain and uncoupling of the oxidative phosphorylation whereas photophosphorylation in vivo is not uncoupled and accordingly photokinesis is not inhibited. On the other hand, the dark movement is not influenced by 10‐‐4 M DCMU, a high concentration, which otherwise stops both cyclic and non‐cyclic photophosphorylation and hence photokinesis. The inhibition by DCMU of that part of the light induced movement which is due to non‐cyclic phosphorylation is reversible by the addition of ferrocyanide (10‐‐2 to 10‐‐4 M) as external electron donor.

The photo‐phobotactic response is less sensitive to DCMU and is not completely suppressed even at 10‐‐3 M. The inhibition is not significantly reversible by the addition of ferrocyanide. However, 10‐‐4 M DCPIP, that does not considerably impair photokinesis, suppresses the photo‐phobotactic responx completely. Thus, contrary to Links' hypothesis, photo‐phobotaxis cannot be linked with photophosphorylation. But there is some evidence that photo‐phobotaxis is coupled with the non‐cyclic electron transport of photosynthesis at another point, which seems to lie between electron supply from oxygen and the inhibition point of DCMU, probably in the region of the acmssory pigments.
Bacterial colonisation of lower airways in health and chronic lung disease
Authors: Weinreich U. M. , Korsgaard J.
Published: February 2008

Background:  To evaluate the colonisation rate and type in different groups of patients with chronic lung diseases, bronchial lavage (BL) fluid was investigated for bacteria.

Methods:  All patients underwent fibre‐optic bronchoscopy as part of routine investigation for remote haemoptysis or nodule investigation. The standard procedure included BL and microbiological culture providing the total number of colony forming units (cfu)/mL and the number of potential pathogenic bacteria (ppb)/mL. Three groups of patients were included: 48 persons had a final diagnosis of no pathology, 53 patients with chronic obstructive pulmonary disease in a stable phase and 32 patients with a final diagnosis of bronchiectasis.

Results:  The median number of cfu cultured from patients with bronchiectasis was 105 cfu/mL compared to 5 103 cfu/mL in patients with COPD and 104 cfu/mL in persons with no pathology. The ppb colonisation rate varied from 10% in persons with no pathology to 43% in patients diagnosed with chronic obstructive pulmonary disease (COPD) and 63% in patients with bronchiectasis. The most frequent bacteria isolated was Haemophilus influenzae. Colonisation rates were associated with frequencies of respiratory infections; patients with bronchiectasis reported a median of three infections per year, patients with COPD reported one infection per year, and persons without pathology reported 0 infections per year (P < 0.05). Within each group a large patient‐to‐patient variation was found.

Conclusions:  Different groups of patients with chronic pulmonary diseases have very different colonisation rates. Patients with bronchiectasis have the highest colonisation rate. This correlates to the reported frequency of lower respiratory tract infections.

Please cite this paper as: Weinreich UM and Korsgaard J. Bacterial colonisation of lower airways in health and chronic lung disease. The Clinical Respiratory Journal 2008; 2: 116–122.
Release in radial growth in the trunk and structural roots of white spruce as measured by dendrochronology
Authors: Urban S.T. , Lieffers V.J. , Macdonald S.E.
Published: February 2008

We used a new technique to examine the response of the trunk and structural roots of white spruce (Piceaglauca (Moench) Voss) to an increase in wind exposure. Ring widths were measured in the roots and trunks of trees located within a 120-year-old, boreal mixedwood stand (control) and at the edge of a road built through the stand 16 years before sampling (released). The observed ring widths were divided by widths predicted from regression to produce ring indices. Response indices were produced by subtracting the ring indices of control trees from those of released trees. Allocation indices were produced by subtracting the ring indices of trunks from those of roots. A final index, quantifying the change in allocation to the root and trunk after road clearing, was produced by subtracting allocation indices of control trees from those of released trees. Following the road clearing, the rate of trunk diameter growth remained unchanged for 3–9 years, while root diameter growth increased. These observations suggest that trunk growth may be suppressed for some years following road clearing as a result of increased root growth. The increase in root growth may help stabilize trees after exposure to increased wind stress by increasing the amount of root wood anchoring and supporting them.
Soil fauna communities in two distinct but adjacent forest types on northern Vancouver Island, British Columbia
Authors: Battigelli Jeffrey P. , Berch Shannon M. , Marshall Valin G.
Published: February 2008

The composition of major soil fauna groups throughout the soil profile in adjacent old growth western red cedar (Thujaplicata Donn)–western hemlock (Tsugaheterophylla (Raf.) Sarg.) and mature hemlock–amabilis fir (Abiesamabilis (Dougl.) Forbes) forests on northern Vancouver Island was compared as part of an integrated study on the possible causes of poor growth of plantation Sitka spruce (Piceasitchensis (Bong.) Carr.) on cedar–hemlock cutblocks. In addition, we examined seasonal changes in vertical distribution of soil fauna within the forest floor of both forest types. At five times between August 1989 and March 1991, four methods were used to extract soil fauna: hand sorting, high-gradient extraction, modified Baermann funnel, and the Formalin method. Forty-one faunal groups were identified in both forest types. The hemlock–amabilis fir forest maintained a higher abundance and biomass of soil fauna than the cedar–hemlock forest. Nematoda were numerically dominant in both forest types followed by Acari, Collembola, and Copepoda. Diplopoda, Enchytraeidae, Diptera larvae, and Acari dominated soil fauna biomass in both forests. Similarity indices indicated that the forest types have similar group diversity. The majority of Nematoda, Acari, and Collembola were found in the LF and H horizons in both forest types. On average, more than 50% of the Acari and Collembola populations were found in the LF horizon while approximately 30% of the Nematoda were found there.
Pollen contamination effects on progeny from an off-site Douglas-fir seed orchard
Authors: Stoehr Michael U. , Webber Joe E. , Painter Roger A.
Published: February 2008

The effects of background pollen contamination were evaluated for first-year height growth pattern of seedlings originating from a Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) coastal–interior transition zone seed orchard located on southern Vancouver Island, British Columbia. Pollen collected from five stands surrounding the orchard (background pollen) and pollen from five half-sib families of the seed orchard were applied to six individual trees in the orchard. The resulting 60 seed lots were raised outdoors in a coastal-climate nursery with five seed lots collected from wild stands of the transition zone. Heights were measured in 10-day intervals during the growing season. Final heights, maximum height growth rate, and growth cessation were subjected to analysis of variance. Growth rate and cessation were derived from data fitted to the logistic growth curve using nonlinear regression analysis. Seedlings sired by the background pollen had significantly greater final heights and growth rates. There were no differences in orchard seedlings in growth cessation probably because all seedlings were exposed to a blackout treatment to force bud set in mid-August. The average final height of wild-stand seedlings from the transition zone was 15% and 21% lower than that of pure orchard seedlings and seedlings sired by the background pollen lots, respectively. Standard deviations for measured traits were similar between orchard seedlings sired by background pollen and orchard pollen. If pollen contamination is not prevented, the faster growing seedlings sired by the background pollen may be preferentially selected during culling in the nursery and outplanted on sites to which they are maladapted.
Use of root-ingrowth cores to assess nutrient limitations in forest ecosystems
Authors: Raich J.W. , Riley R.H. , Vitousek P.M.
Published: February 2008

We tested the suitability of using root-ingrowth cores to identify nutrient limitations in a Metrosideros-dominated forest in Hawaii that previously was demonstrated to be nitrogen limited. Plastic mesh cylinders filled with a calcined-clay growing medium were treated with nitrogen, phosphorus, calcium and potassium, or distilled water, and were inserted into the surface soil of the forest. After 6 months in situ, significantly more roots grew into the cores dosed with nitrogen. Fertilization trials provide the best means of identifying nutrient limitations to forest growth, but our results indicate that root-ingrowth cores can provide a reliable, alternative method of assessing nutrient limitations in forest ecosystems.
Skeletal muscle lipid oxidation and obesity: influence of weight loss and exercise
Authors: Berggren Jason R. , Boyle Kristen E. , Chapman William H. , Houmard Joseph A.
Published: February 2008

Obesity is associated with a decrement in the ability of skeletal muscle to oxidize lipid. The purpose of this investigation was to determine whether clinical interventions (weight loss, exercise training) could reverse the impairment in fatty acid oxidation (FAO) evident in extremely obese individuals. FAO was assessed by incubating skeletal muscle homogenates with [1-14C]palmitate and measuring 14CO2 production. Weight loss was studied using both cross-sectional and longitudinal designs. Muscle FAO in extremely obese women who had lost weight (decrease in body mass of ∼50 kg) was compared with extremely obese and lean individuals (BMI of 22.8 ± 1.2, 50.7 ± 3.9, and 36.5 ± 3.5 kg/m2 for lean, obese, and obese after weight loss, respectively). There was no difference in muscle FAO between the extremely obese and weight loss groups, and FAO was depressed (−45%; P ≤ 0.05) compared with the lean subjects. Muscle FAO also did not change in extremely obese women ( n = 8) before and 1 yr after a 55-kg weight loss. In contrast, 10 consecutive days of exercise training increased ( P ≤ 0.05) FAO in the skeletal muscle of lean (+1.7-fold), obese (+1.8-fold), and previously extremely obese subjects after weight loss (+2.6-fold). mRNA content for PDK4, CPT I, and PGC-1α corresponded with FAO in that there were no changes with weight loss and an increase with physical activity. These data indicate that a defect in the ability to oxidize lipid in skeletal muscle is evident with obesity, which is corrected with exercise training but persists after weight loss.
The Aging Cardiomyocyte: A Mini-Review
Authors: Bernhard D. , Laufer G.
Published: February 2008

Background: Aging per se is a risk factor for reduced cardiac function and heart diseases, even when adjusted for aging-associated cardiovascular risk factors. Accordingly, aging-related biochemical and cell-biological changes lead to pathophysiological conditions, especially reduced heart function and heart disease. Objective: In this review, we summarize the changes that occur as the heart ages from youth to old age on the basis of the cardiac myocyte. Aging phenotypes and underlying mechanisms shall be discussed that affect cardiomyocyte repair, signaling, structure, and function. Methods: Review of the literature. Results: The following factors play vital roles in the aging of cardiomyocytes: oxidative stress, inflammation, cellular protection and repair, telomere integrity, survival and death, metabolism, post-translational modifications, and altered gene expression. Importantly, non-cardiomyocyte-based aging processes (vascular, fibroblast, extracellular matrix, etc.) in the heart will interfere with cardiomyocyte aging and cardiac function. Conclusion: Based on our analyses, we postulate that the physiological aging process of the heart and of the cardiomyocyte is primarily driven by intrinsic aging factors. However, extrinsic aging factors, e.g. smoking, also make an important contribution to pathologically accelerated aging of the heart.
Effects of Synaptic Synchrony on the Neuronal Input-Output Relationship
Authors: Li Xiaoshen , Ascoli Giorgio A.
Published: February 2008

The firing rate of individual neurons depends on the firing frequency of their distributed synaptic inputs, with linear and nonlinear relations subserving different computational functions. This letter explores the relationship between the degree of synchrony among excitatory synapses and the linearity of the response using detailed compartmental models of cortical pyramidal cells. Synchronous input resulted in a linear input-output relationship, while asynchronous stimulation yielded sub- and supraproportional outputs at low and high frequencies, respectively. The dependence of input-output linearity on synchrony was sigmoidal and considerably robust with respect to dendritic location, stimulus irregularity, and alteration of active and synaptic properties. Moreover, synchrony affected firing rate differently at lower and higher input frequencies. A reduced integrate-and-fire model suggested a mechanism explaining these results based on spatiotemporal integration, with fundamental implications relating synchrony to memory encoding.
Using Aptamer–Nanoparticle Conjugates for Cancer Cells Detection
Authors: Chen Xiaolan , Huang Yu-Fen , Tan Weihong
Published: February 2008

Accurate and sensitive diagnosis is particularly critical in the early stages of tumor development in order to facilitate the selection of effective therapeutic pathways and improve clinical outcomes. However, accurate and sensitive detection of malignant cells requires probes capable
of differentiating the unique features of target cells at the molecular level. Recently, aptamers have emerged as a powerful class of ligands for specific biomolecular targeting. To select aptamers which can bind their target cells with high affinity and specificity, the cell-based SELEX method
has been developed. Because of its fast enrichment, easy operation and ability to obtain a group of probes simultaneously, cell-based SELEX has allowed expansion of aptamer use to the fields of cancer cell detection, imaging, and targeted therapy. In large part, the development of nanomaterials
as aptamer bioconjugates has increased the interest of using aptamer–nanoparticle conjugates as potential diagnostic and therapeutic vehicles. In this review, we will outline the routes of synthesis, fundamental properties, and potential applications of several types of nanoparticles,
including dyedoped silica nanoparticles, gold-based nanoparticles, and magnetic nanoparticles. By combining such nanomaterials with cancer-related aptamers, a novel class of bioconjugates is emerging with promising potential for application in cancer separation, detection, imaging and targeted
therapy.
Metal and Magnetic Nanostructures for Cancer Detection, Imaging, and Therapy
Authors: Rozanova Nadejda , Zhang Jin Z.
Published: February 2008

Metal and magnetic nanostructures process novel optical, electronic, thermal, and magnetic properties that are promising for biomedical applications such as drug delivery and cancer detection, imaging and therapy through various mechanisms. Nanomaterials can be tailored in terms of their size, shape, and surface characteristics for specific applications such as photothermal ablation therapy, photodynamic therapy, and magnetically targeted drug delivery. Specific examples are drawn from many recent studies on the development and exploitation of new metal and magnetic nanostructures for cancer treatment. Emphasis is placed on the unique properties of nanomaterials for such applications.
Nanomaterial Based Electrochemical DNA Biosensors and Bioassays
Authors: Mao Xun , Liu Guodong
Published: February 2008

This article reviews recent advances in nanomaterials based electrochemical DNA biosensors and bioassays. Colloidal gold/silver/platinum, semiconductor nanoparticles, nanowires and markers loaded nanocarriers (carbon nanotubes, apoferritin and silica nanoparticles), dendrimers, magnetic
nanoparticles and liposome beads are discussed. The enormous signal enhancement associated with the use of nanomaterial labels and with the formation of nanomaterial–DNA hybrids provides the basis for ultrasensitive electrochemical detection of disease-related gene markers, biothreat
agents, or infectious agents. In general, all endeavors cited here are geared to achieve one or more of the following goals: signal amplification by several orders of magnitude, lower detection limits, and detecting multiple targets.
Precipitation and Latent Heating Characteristics of the Major Tropical Western Pacific Cloud Regimes
Authors: Jakob Christian , Schumacher Courtney
Published: February 2008

An objective tropical cloud regime classification based on daytime averaged cloud-top pressure and optical thickness information from the International Satellite Cloud Climatology Project (ISCCP) is combined with precipitation and latent heating characteristics derived using the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). TRMM precipitation information is stratified into the ISCCP regimes in the tropical western Pacific (TWP), revealing the following three major precipitation regimes: a heavy (12 mm day−1) precipitation regime dominated by stratiform precipitation and top-heavy latent heating; a regime with moderate (5 mm day−1) precipitation amounts, mostly convective in nature with more midlevel latent heating; and a low (2 mm day−1) precipitation regime with a relatively large rain contribution from shallow convection, compared to the other regimes. Although three of the ISCCP cloud regimes are linked to the more convective, moderate precipitation regime, only one of the cloud regimes is associated with the more stratiform, top-heavy latent heating regime, making the ISCCP regimes a potentially useful tool for the further study of this dynamically important tropical weather state. Similarly, only one cloud regime is associated with the more shallow convective precipitation regime.

In terms of the TWP, precipitation and latent heating are dominated by the relatively infrequent (15%) occurrence of the strongly precipitating top-heavy latent heating state and by the frequent (>30%) occurrence of one of the more moderately precipitating convective states. The low precipitation/shallow cumulus regime occurs often (i.e., 25% of the time) but does not contribute strongly to the overall precipitation and latent heating. Each of these regimes also shows distinct geographical patterns in the TWP, thus providing insight into the distribution of convective and stratiform rain across the tropics. This study confirms the potential usefulness of the objective regime classification based on ISCCP, and it opens several new avenues for studying the interaction of convection with the large-scale tropical circulation.
The Political Economy of Teacher Quality in School Mathematics
Authors: Tate William F.
Published: February 2008

Mathematics education is linked to modern technological advancement, citizenship, and matters of political economy. Access to quality mathematics teachers can have a profound influence on African American males. This article focuses on several salient issues related to the question “What is a qualified teacher?” In particular, the article describes common concerns and challenges associated with teacher quality and the advancement of African American males and other traditionally under served demographic groups in mathematics.
Ghana's Construction Industry and Global Competition
Authors: Assibey-Mensah George O.
Published: February 2008

Doing business in Ghana could not have come at a better time. In the name of globalization, the government of President Kufuor has liberalized trade so that foreign construction companies easily compete with Ghana's own construction firms for big-ticket contracts. A major consequence of the bidding policy, however, is that globalization has negatively affected the nation's indigenous construction contractors in competing with large, international, private corporations for public contracts in Ghana. The situation has rendered indigenous entrepreneurs not only virtually helpless but also continually lacking vital resources. This article examines the current predicament of Ghana's indigenous construction businesses in terms of their inability to effectively compete with foreign construction firms. The author proposes meaningful ways in which the government should formulate a much-needed framework for developing, nurturing, and sustaining their operational infrastructure with the view to preparing them to compete effectively with foreign businesses, particularly for lucrative public-construction contracts in Ghana.
Alternative Economics—A Missing Component in the African American Studies Curriculum
Authors: Nembhard Jessica Gordon
Published: February 2008

The author expands on questions about the place and role of economics and Black political economy in African American Studies by asking about what economic models are taught and how economic agency is taught. This article reiterates the importance of economic content in Africana Studies and proposes that even when economics is taught the focus is on poverty and theories about scarcity, competition, and discrimination without analyses of group economics, game theory, or alternative economic institutions. African American Studies curricula do not provide students with the methodological tools to theorize and apply Black political economic analysis. The article reviews the paucity of courses on alternative economic development and cooperative economics. The author reviews the history of Black alternative economic strategies and African American cooperative economic thought and practice. The article ends with definitions and concepts that can be included in Africana Studies curricula to teach students how to become economic development and policy analysts and economic change agents.