bluuebunny/crossref_metadata_2025 huggingface dataset:
Small Mammal Responses to Fine Woody Debris and Forest Fuel Reduction in Southwest Oregon
Authors: MANNING JEFFREY A. , EDGE W. DANIEL
Published: March 2008

Abstract:Despite its importance for wildlife, most forests in the Pacific Northwest contain low volumes of large downed wood compared to fine woody debris (FWD). We used a replicated experiment to compare short‐term responses of deer mice (Peromyscus maniculatus) and western red‐backed voles (Clethrionomys californicus) among 3 arrangements of FWD: piled, lopped and scattered, and pile burning, a commonly used method of fuel reduction in commercial Douglas fir (Pseudotsuga menziesii) forests in southwest Oregon, USA. We assessed habitat use, density, and survival of mice and voles during 2 consecutive summers (Jun—Aug 1999 and 2000). Both mice and voles used FWD cover disproportionately from its availability, and they differed in their responses to specific FWD arrangements. Mice used piled FWD (proportional use = 37.0%, 90% CI = 33.0–44.0) 43% more than expected (26.0). Number of mice captured (x̄ = 1.9 mice, 90% CI = 1.5–2.5) and index of home range size (x̄ = 4.8 m, 90% CI = 0.7–8.9) at individual FWD piles decreased up to 16% and increased up to 50%, respectively, for each 1‐m increase in distance from piles. Voles used all FWD cover classes in proportion to availability, but number of voles captured increased slightly (x̄ = 0.016 voles/m, 90% CI = 0.001–0.031) for each 1‐m increase in distance from piles. Piled FWD had no discernable effect on population density and apparent survival of mice, but analyses had low power (0.25, 0.67). Our results suggest that piling FWD would benefit deer mice, whereas lopped and scattered FWD might benefit voles. Thus, a combination of methods to reduce fire risk should be considered to accommodate multiple small mammal species. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):625–632; 2008)
Cerulean Warbler Reproduction, Survival, and Models of Population Decline
Authors: BUEHLER DAVID A. , GIOCOMO JAMES J. , JONES JASON , HAMEL PAUL B. , ROGERS CHRISTOPHER M. , BEACHY TIFFANY A. , VARBLE DUSTIN W. , NICHOLSON CHARLES P. , ROTH KIRK L. , BARG JENNIFER , ROBERTSON RALEIGH J. , ROBB JOSEPH R. , ISLAM KAMAL
Published: March 2008

Abstract: We present and compare demographic data for cerulean warblers (Dendroica cerulea) from 5 study sites across the range of the species from 1992 to 2006. We conducted field studies to collect data on daily nest survival, nest success, and young fledged per successful nest, and we used data to estimate fecundity. Daily nest survival, nest success, young fledged, and fecundity varied widely across the cerulean range and among years. Study sites in agriculture‐dominated landscapes (Mississippi Alluvial Valley, IN, and MI, USA) had negative growth rates in all years monitored because measured values of nest success and young produced per successful nest were incapable of offsetting apparent mortality. Ontario (Canada) and Tennessee (USA) populations had greater nest success and fecundity but still appeared to be incapable of producing stable populations (λ = 1) under field‐measured and assumed conditions. We had survival data only for one site (Ontario); thus, additional survival data are greatly needed to enable more reliable estimates of population growth. Conservation strategies for cerulean warblers in agriculture‐dominated landscapes (e.g., Mississippi Alluvial Valley, IN, and MI) may require major landscape‐level habitat reconfiguration to change agriculture‐dominated landscapes to forest‐dominated landscapes to increase fecundity. Conservation strategies in predominantly forested landscapes in the core of the range (e.g., TN) require a focus on minimizing habitat loss and developing management prescriptions capable of improving fecundity. In both cases, based on sensitivity and elasticity analyses, efforts to improve survival during the nonbreeding season would have the greatest positive effect on population growth. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):646–653; 2008)
Foot Surveys of Large Mammals in Woodlands of Western Tanzania
Authors: WALTERT MATTHIAS , MEYER BRITTA , SHANYANGI MUSSA WILSON , BALOZI JOHANNES JOHN , KITWARA OMARI , QOLLI STEPHAN , KRISCHKE HUBERT , MÜHLENBERG MICHAEL
Published: March 2008

Abstract: Reliable assessments of large mammal population sizes are crucial for the management of protected areas. We tested feasibility of foot surveys for population assessments of large mammals in western Tanzanian woodland, comparing estimates of herbivore densities from line‐transect data from a National Park with those from an adjacent Game Reserve (GR). We used a Geographic Information System (GIS) and Global Positioning System—supported field design, consisting of systematically distributed closed‐circuit transects, and recorded sighting distances and angles. Total survey effort was 1,032 km, conducted within the dry season. We fitted detection functions to distance data with the help of DISTANCE 4.1, using the 3 habitat categories woodland, grassland, and swamp as covariates for detection probability. We found estimates of density and abundance to be reliable for 19 out of 20 larger mammalian herbivores and found significant differences in density between the Park and the GR for 5 species, of which 4 had a higher density in the Park and one had a higher density in the GR. Our results show that, using GIS support and modern navigation methods, foot‐transect surveys can be effective in providing accurate data on woodland herbivore populations even in large study areas. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):603–610; 2008)
Piping Plover Chick Foraging, Growth, and Survival in the Great Plains
Authors: FER DANIELLE LE , FRASER JAMES D. , KRUSE CASEY D.
Published: March 2008

Abstract:We tested the hypothesis that piping plover (Charadrius melodus) habitat quality and chick survival on the Missouri River, USA, were lower on a cold‐water reservoir and downstream from a hypolimnetic (cold‐water) release dam with diel water fluctuations (Garrison Dam) than downstream from an epilimnetic dam (Gavins Point Dam). Plovers in adjacent alkali wetlands provided an index to the maximum reproductive potential in the region. Chicks gained weight more rapidly in the alkali wetlands than on epilimnetic and hypolimnetic river reaches. Invertebrate numbers and biomass were higher in the wetlands and epilimnetic reach, but chick survival was lower on the epilimnetic reach. Thus, piping plovers adapted to a variety of prey densities, and other factors, likely predation, reduced survival rates in the epilimnetic reach. Temporal and spatial variability in site quality indices suggests the need for a regional management strategy with different strategies at each site. Managers can minimize effects of local fluctuations in resource abundance and predators by ensuring protection of or creating geographically dispersed habitat. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):682–687; 2008)
Florida Panther Habitat Selection Analysis of Concurrent GPS and VHF Telemetry Data
Authors: LAND E. DARRELL , SHINDLE DAVID B. , KAWULA ROBERT J. , BENSON JOHN F. , LOTZ MARK A. , ONORATO DAVE P.
Published: March 2008

Abstract: Florida panthers (Puma concolor coryi) are listed as an endangered subspecies in the United States and they exist in a single Florida population with <100 individuals; all known reproduction occurs south of Lake Okeechobee. Habitat loss is the biggest threat to this small population and previous studies of habitat selection have relied on very high frequency (VHF) telemetry data collected almost exclusively during diurnal periods. We investigated habitat selection of 12 panthers in the northern portion of the breeding range using 1) Global Positioning System (GPS) telemetry data collected during nocturnal and diurnal periods and 2) VHF telemetry data collected only during diurnal periods. Analysis of both types of telemetry data yielded similar results as panthers selected upland (P < 0.001) and wetland (P < 0.001) forested habitat types. Our results indicated that forests are the habitats selected by panthers and generally support the current United States Fish and Wildlife Service panther habitat ranking system. We suggest that future studies with greater numbers of panthers should investigate panther habitat selection using GPS telemetry data collected throughout the range of the Florida panther and with location attempts scheduled more evenly across the diel period. Global Positioning System radiocollars were effective at obtaining previously unavailable nocturnal telemetry data on panthers; however, we recommend that panther researchers continue to collect VHF telemetry data until acquisition rates and durability of GPS collars improve. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):633–639; 2008)
Relationship of Endangered Amphibians to Landscape Disturbance
Authors: WARREN STEVEN D. , BÜTTNER REINER
Published: March 2008

Abstract: We examined the density of 2 endangered amphibians, natterjack toads (Bufo calamita) and yellow‐bellied toads (Bombina variegata), in 150 breeding pools at each of 2 military training areas in the German state of Bavaria. We selected pools to ensure a wide range of observable ground disturbance resulting from military vehicular traffic during cross‐country maneuvers. Both species exhibited significant affinity for pools with high levels of ground disturbance. Natterjack toads preferred pools with 80–100% ground disturbance; yellow‐bellied toads preferentially occupied pools with 40–100% ground disturbance. Pools occupied by the target species were characterized by higher levels of bare ground and minimal vegetation. Among other observed amphibians, European edible frogs (Rana esculenta) preferred pools with ≤60% ground disturbance, less bare ground, more vegetative cover, and disturbance >2 years old. Common tree frogs (Hyla arborea), smooth newts (Triturus vulgaris), and alpine newts (T. alpestris) showed no preference for level of disturbance; densities were correlated to parameters apparently unrelated to disturbance. The habitat mosaic created by the heterogeneous nature of military training disturbance may help explain the high biodiversity that often characterizes military training areas. Preservation of native biodiversity is dependent on maintaining an appropriate disturbance regime that, in turn, maintains a habitat mosaic conducive to the presence of native species adapted to a broad disturbance—succession continuum. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):738–744; 2008)
Evaluating Cementum to Determine Past Reproduction in Northern Sea Otters
Authors: VON BIELA VANESSA R. , TESTA J. WARD , GILL VERENA A. , BURNS JENNIFER M.
Published: March 2008

Abstract: Age at first reproduction (AFR) has been difficult to quantify in mammals, as the most commonly used methods require reproductive tracts or direct observations. However, work in several large mammal species suggests that the width of cementum light bands in teeth decline once females begin to reproduce, suggesting that teeth structures might provide a new tool to examine AFR. To determine if changes in cementum light band width could be used to calculate AFR for the northern sea otter (Enhydra lutris kenyoni), we measured cementum light band widths on sectioned premolar teeth and compared them to reproductive tracts. We classified otters as parous if any single light band was narrower than a threshold value, selected as the value that minimized error rates. At a threshold value of 0.32, we correctly identified otters as parous or nulliparous in 83% of cases (n = 92) as compared to reproductive tracts, and the AFR estimated from teeth samples (3.52 ± 0.032 yr) was not different from that determined by reproductive tract analysis (3.45 ± 0.031 yr; t‐test, P > 0.05). These data support the use of cementum as an indicator of past reproduction in individual female otters, which can then be used to estimate average AFR. Given that declines in cementum width have been described for other mammal species, the same quantitative approach used here could be applied to other species. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):618–624; 2008)
Effectiveness of Lethal, Directed Wolf‐Depredation Control in Minnesota
Authors: HARPER ELIZABETH K. , PAUL WILLIAM J. , MECH L. DAVID , WEISBERG SANFORD
Published: March 2008

Abstract: Wolf (Canis lupus) depredations on livestock in Minnesota, USA, are an economic problem for many livestock producers, and depredating wolves are lethally controlled. We sought to determine the effectiveness of lethal control through the analysis of data from 923 government‐verified wolf depredations from 1979 to 1998. We analyzed the data by 1) assessing the correlations between the number of wolves killed in response to depredations with number of depredations the following year at state and local levels, and 2) the time to the next depredation. No analysis indicated that trapping wolves substantially reduced the following year's depredations at state or local levels. However, more specific analyses indicated that in certain situations, killing wolves was more effective than no action (i.e., not trapping). For example, trapping and killing adult males decreased the re‐depredation risk. At sheep farms, killing wolves was generally effective. Attempting to trap, regardless of the results, seemed more effective at reducing depredations than not trapping, suggesting that mere human activity near depredation sites might deter future depredations. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):778–784; 2008)
Factors Affecting Detection of Burrowing Owl Nests During Standardized Surveys
Authors: CONWAY COURTNEY J. , GARCIA VICTORIA , SMITH MATTHEW D. , HUGHES KATIE
Published: March 2008

Abstract: Identifying causes of declines and evaluating effects of management practices on persistence of local populations of burrowing owls (Athene cunicularia) requires accurate estimates of abundance and population trends. Moreover, regulatory agencies in the United States and Canada typically require surveys to detect nest burrows prior to approving developments or other activities in areas that are potentially suitable for nesting burrowing owls. In general, guidelines on timing of surveys have been lacking and surveys have been conducted at different times of day and in different stages of the nesting cycle. We used logistic regression to evaluate 7 factors that could potentially affect probability of a surveyor detecting a burrowing owl nest. We conducted 1,444 detection trials at 323 burrowing owl nests within 3 study areas in Washington and Wyoming, USA, between February and August 2000–2002. Detection probability was highest during the nestling period and increased with ambient temperature. The other 5 factors that we examined (i.e., study area, time of day, timing within the breeding season, wind speed, % cloud cover) interacted with another factor to influence detection probability. Use of call‐broadcast surveys increased detection probability, even during daylight hours when we detected >95% of owls visually. Optimal timing of surveys will vary due to differences in breeding phenology and differences in nesting behavior across populations. Nevertheless, we recommend ≥3 surveys per year: one that coincides with the laying and incubation period, another that coincides with the early nestling period, and a third that coincides with the late nestling period. In northern latitudes, surveys can be conducted throughout the day. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):688–696; 2008)
Mating Behavior as a Possible Cause of Bat Fatalities at Wind Turbines
Authors: CRYAN PAUL M.
Published: March 2008

Abstract:Bats are killed by wind turbines in North America and Europe in large numbers, yet a satisfactory explanation for this phenomenon remains elusive. Most bat fatalities at turbines thus far occur during late summer and autumn and involve species that roost in trees. In this commentary I draw on existing literature to illustrate how previous behavioral observations of the affected species might help explain these fatalities. I hypothesize that tree bats collide with turbines while engaging in mating behaviors that center on the tallest trees in a landscape, and that such behaviors stem from 2 different mating systems (resource defense polygyny and lekking). Bats use vision to move across landscapes and might react to the visual stimulus of turbines as they do to tall trees. This scenario has serious conservation and management implications. If mating bats are drawn to turbines, wind energy facilities may act as population sinks and risk may be hard to assess before turbines are built. Researchers could observe bat behavior and experimentally manipulate trees, turbines, or other tall structures to test the hypothesis that tree bats mate at the tallest trees. If this hypothesis is supported, management actions aimed at decreasing the attractiveness of turbines to tree bats may help alleviate the problem. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):845–849; 2008)
Hormesis and Adaptive Cellular Control Systems
Authors: Zhang Qiang , Pi Jingbo , Woods Courtney G. , Jarabek Annie M. , Clewell Harvey J. , Andersen Melvin E.
Published: March 2008

Hormetic dose response occurs for many endpoints associated with exposures of biological organisms to environmental stressors. Cell-based U- or inverted U-shaped responses may derive from common processes involved in activation of adaptive responses required to protect cells from stressful environments. These adaptive pathways extend the region of cellular homeostasis and are protective against ultimate cell, organ, and system toxicity. However, the activation of stress responses carries a significant energetic cost to the cell, leading to alterations of a variety of basal cellular functions in adapted or stressed cells. This tradeoff of resources between the unstressed and adapted states may lead to U-or inverted U-shaped dose response curves for some precursor endpoints. We examine this general hypothesis with chlorine, a prototype oxidative stressor, using a combination of cellular studies with gene expression analysis of response pathways and with computational modeling of activation of control networks. Discrete cellular states are expected as a function of exposure concentration and duration. These cellular states include normal functioning state, adaptive and stressed states at mild to intermediate exposures, and overt toxicity in the presence of an overwhelming concentration of stressors. These transitions can be used to refine default risk assessment practices that do not currently accommodate adaptive responses.
Trends in Fear of Crime in a Western Canadian City: 1984, 1994, and 2004
Authors: Weinrath Michael , Clarke Kristin , Forde David R.
Published: March 2008

Criminologists have shown much interest in the distribution, causes, and consequences of fear of crime, but few studies have examined trends in fear. Using data from the Winnipeg Area Study from 1984, 1994, and 2004, and official crime data from the Winnipeg Police Service, we examine trends in fear of crime and compare them to reported crime. Fear of crime is evaluated by using an index compiled from five offence-specific indicators that asks how worried people are about becoming victims of theft, burglary, armed robbery, fraud, and sexual assault. Bonferonni procedures and regression methods are used to assess differences in fear of crime. The results show that respondents report low levels of fear of crime over the 20-year period. The results also indicate a lack of correspondence between fear of crime and official measures of crime. These findings challenge the use of fear of crime measures by policy makers seeking to evaluate criminal justice initiatives.
Forensic Barefoot Morphology Comparison
Authors: Yamashita A.B.
Published: March 2008

Forensic barefoot morphology comparison refers to the examination of the weight-bearing areas of the human foot, in order to include or exclude suspects in a criminal investigation. Casts or inked impressions of a foot can be compared to bare or socked foot impressions found at a crime scene, or to insoles of footwear linked to a crime scene. The comparison process is similar to that of a tire being compared to a tire track or a shoe being compared to a footwear impression. In order to justify presenting this technique in court, extensive research has been carried out to show the variability of barefoot impressions. Lawyers and investigators should be aware of the existence of this type of comparison, and should consider its use in cases where it is warranted.
Are the lights coming on? How can we tell? English language learners and literacy assessment
Authors: Toohey Kelleen
Published: March 2008

Abstract:

This article explores definitions of reading comprehension, research on how reading comprehension is assessed, and issues in assessing the reading comprehension of English language learners (ELLs). By way of illustration, I present aspects of the literacy practices of an intermediate-grade ELL in a suburban school of the Lower Mainland of British Columbia. This learner, Aman, is evaluated as being ‘not yet within expectations’ on a reading-comprehension test given by the BC Ministry of Education. The article examines Aman's writing, showing that she has appropriated some important aspects of written language, and argues that her writing and reading comprehension must be supported so that she can achieve as fully as possible the benefits of her education. This case is representative of many ELLs’ trajectories in English literacy learning in BC schools and illustrates some of the human faces behind ELL achievement patterns.
Gibbs’ Paradox and the Definition of Entropy
Authors: Swendsen Robert H.
Published: March 2008

Gibbs’ Paradox is shown to arise from an incorrect traditional definition of the entropy that has unfortunately become entrenched in physics textbooks. Among its flaws, the traditional definition predicts a violation of the second law of thermodynamics when applied to colloids. By adopting Boltzmann’s definition of the entropy, the violation of the second law is eliminated, the properties of colloids are correctly predicted, and Gibbs’ Paradox vanishes.
Air‐Stable and Highly Active Dendritic Phosphine Oxide‐ Stabilized Palladium Nanoparticles: Preparation, Characterization and Applications in the Carbon‐Carbon Bond Formation and Hydrogenation Reactions
Authors: Wu Lei , Li Zhi‐Wei , Zhang Feng , He Yan‐Mei , Fan Qing‐Hua
Published: March 2008

Dendrimer‐stabilized palladium nanoparticles were formed in the reduction of palldium bis(acetylacetonate) [Pd(acac)2] in the presence of phosphine dendrimer ligands using hydrogen in tetrahydrofuran. The resulting Pd nanoparticles were characterized by TEM, 31P NMR and 31P MAS NMR. The results indicated that the dendritic phosphine ligands were oxidized to phosphine oxides. These dendrimer‐stabilized Pd nanoparticles were demonstrated to be efficient catalysts for Suzuki and Stille coupling reactions and hydrogenations. The dendritic wedges served as a stabilizer for keeping the nanoparticles from aggregating, and as a vehicle for facilitating the separation and/or the recycling of the Pd catalyst. In the case of the Suzuki coupling reaction, these Pd nanoparticles exhibited high catalytic efficiency (TON up to 65,000) and air stability as compared with the commonly used homogeneous catalyst tetrakis(triphenylphosphine)palladium [Pd(PPh3)4]. In addition, the results obtained from the bulky dendritic substrate suggest that the Pd nanoparticles might act as reservoir of catalytically active species, and that the reaction is actually catalyzed by the soluble Pd(0) and/or Pd(II) species leached from the nanoparticle surface.
Extensive Re‐Investigations of Pressure Effects in Rhodium‐ Catalyzed Asymmetric Hydrogenations
Authors: Alame Mohamad , Pestre Nathalie , de Bellefon Claude
Published: March 2008

The catalytic hydrogenation of three pro‐chiral substrates methyl Z‐α‐acetamidocinnamate (MAC), methyl 2‐acetamidoacrylate (M‐Acrylate) and ethyl 4‐methyl‐3‐acetamido‐2‐propanoate (E‐EMAP) with rhodium precursors complexed with chiral diphosphines is reported at 1–30 bar hydrogen pressure. A library of 56 chiral diphosphines, including 23 BINAP derivatives, 7 JOSIPHOS, 5 BIPHEP, 3 DUPHOS derivatives, and 18 other ligands, was used. While it was generally accepted that high hydrogen pressure would result in lower ees, it is now demonstrated on a statistical basis that an equivalent distribution between beneficial and detrimental pressure effects on ee prevails and that the hydrogen pressure effect on enantioslectivity is not an isolated phenomenon since more than 33% of the reaction systems studied are strongly affected. In some case, the enantioselectivity can be improved up to 97% just by applying a higher hydrogen pressure. Extension of these conclusions to other non‐chiral reagents is proposed.
Development of a Model System for the Study of Long Distance Electron Transfer in Peptides
Authors: Cordes Meike , Jacques Olivier , Köttgen Agnieszka , Jasper Christian , Boudebous Hassen , Giese Bernd
Published: March 2008

We have designed and synthesized a peptide model in which stepwise electron transfer (ET) through amino acid side chains could be observed. An injection system, which generates an electron hole upon laser irradiation, was connected directly to the aromatic side chain of a modified C‐terminal amino acid. This electron acceptor could be observed by transient absorption spectroscopy. The N‐terminal amino acid tyrosine acts as an electron donor, giving a different signal in the transient absorption spectrum. Additional non‐natural oxidizable aromatic amino acids were synthesized as spectroscopic sensors to detect oxidized amino acid side chains as chemical intermediates in long range ET.
Leaching and fastness behavior of cotton fabrics dyed with different type of dyes using sol‐gel process
Authors: Aķ⋅it Aysun Cireli , Onar Nurhan
Published: March 2008

Cotton fabrics were dyed with reactive, direct, and basic dyes by sol‐gel process and exhausting process. As to this aim, the solutions of reactive, direct, and basic dyes were prepared by sol‐gel process and then cotton fabrics were treated at 80°C for 10 min with these solutions and dried at 120°C for 20 min. Dyeing solutions contained tetraethyl orthosilicate and 3‐glycidoxypropyl‐trimethoxysilane as precursor, ethanol and water as solvent for sol‐gel process. The wash fastness, light fastness, rubbing fastness and the degree of leaching, the light fading value, and dyeing yield of dyeings were evaluated. Moreover, the effect on dyeing yield, fastnesses, leaching, and fading properties of adding of sodium acetate trihydrate in dyeing solutions for sol‐gel process was firstly studied. It was found that the dyeing yield of dyed cotton fabrics with the direct dyes significantly improved with using sol‐gel process with adding sodium acetate trihydrate in comparison with exhausting process. The color fastness values to washing and to light of the basic dyeing increased with using sol‐gel process without adding sodium acetate trihydrate in comparison with exhausting process. The degree of leaching of dyed fabrics with the basic and reactive dyes decreased with using sol‐gel process with adding sodium acetate trihydrate in comparison with exhausting process. The light fading value of dyed cotton fabrics with the basic and direct dyes after 120 h irridation decreased with using sol‐gel process with adding sodium acetate trihydrate in comparison with exhausting process. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
The structure and dynamic properties of nitrile–butadiene rubber/poly(vinyl chloride)/hindered phenol crosslinked composites
Authors: Xiang Ping , Zhao Xiu‐Ying , Xiao Da‐Ling , Lu Yong‐Lai , Zhang Li‐Qun
Published: March 2008

In this article, a new nitrile–butadiene rubber (NBR) crosslinked composites containing poly(viny chloride) (PVC) and hindered phenol (AO‐80 and AO‐60) was successfully prepared by melt‐blending procedure. Microstruture and dynamic mechanical properties of the composites were investigated using SEM, DSC, XRD, and DMTA. Most of hindered phenol was dissolved in the NBR/PVC matrix and formed a much fine dispersion. The results of DSC and DMTA showed that strong intermolecular interaction was formed between the hindered phenol and NBR/PVC matrix. The NBR/PVC/AO‐80 crosslinked composites showed only one transition with higher glass transition temperature and higher tan δ value than the neat matrix, whereas for the NBR/PVC/AO‐60 crosslinked composites, a new transition appeared above the glass transition temperature of matrix, which was associated with the intermolecular interaction between AO‐60 and PVC component of the matrix. Both AO‐80 and AO‐60 in the crosslinked composites existed in amorphous form. Furthermore, the chemical crosslinking of composites resulted in better properties of the materials, e.g., considerable tensile strength and applied elastic reversion. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Improving the mechanical properties of polypropylene via melt vibration
Authors: Li Youbing , Shen Kaizhi
Published: March 2008

The effect of melt vibration on the mechanical properties of polypropylene prepared by low‐frequency vibration‐assisted injection molding (VAIM) has been investigated. With the application of melt vibration technology, the mechanical properties of polypropylene are improved. The yield strength increases with the increment of the vibration frequency, and a peak stands at a special frequency for VAIM; the elongation at break decreases first and then increases with increasing vibration frequency, and a valley stands at a special frequency. The tensile properties increase sharply at an enlarged vibration pressure amplitude with sharply decreased elongation at break. The Young's modulus and impact strength also increase with the vibration frequency and pressure vibration amplitude. When it is prepared at 59.4 MPa and 0.7 Hz, the maximal yield strength is approximately 40 MPa versus 33.7 MPa for a conventional sample; an 18.7% increase in the tensile strength is produced. Self‐reinforcing and self‐toughening polypropylene molded parts have been found to be prepared at a high vibration frequency or at a large pressure vibration amplitude. Scanning electron micrographs have shown that, in the vibration field, the enhancement of the mechanical properties is attributable to more pronounced spherulite orientation and increased crystallinity in comparison with conventional injection moldings. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, characterization, and redox and electrochromic behaviors of poly(3‐n‐octyloxythiophene)
Authors: Sheng Chen , Wenting Bao , Shijian Tu , Yuechuan Wang
Published: March 2008

Poly(3‐n‐octyloxythiophene), a conjugated polymer, which possessed solubility in common organic solvents, was synthesized by electrochemical polymerization in the presence of lithium perchlorate as the supporting electrolyte and sodium dodecyl sulfate as the surfactant in an aqueous medium. Characterizations of the intermediate, monomer, and polymer were performed by NMR spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, and gel permeation chromatography. The process of electrochemical polymerization and the electrochemical redox behaviors were investigated by cyclic voltammetry and the potentiostatic method. A poly(3‐n‐octyloxythiophene) film that was deposited on a platinum electrode was found to exhibit electrochromic behaviors, and it switched electrochemically between blue–green oxidized and dark red reduced states. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Flammability of blends of low‐density polyethylene and ethylene vinyl acetate crosslinked by both dicumyl peroxide and ionizing radiation for wire and cable applications
Authors: Shukri T. M. , Mosnáček J. , Basfar A. A. , Bahattab M. A. , Noireaux P. , Courdreuse A.
Published: March 2008

Formulations of chemically crosslinked and radiation‐crosslinked low‐density polyethylene (LDPE) containing an intumescent flame retardant such as ammonium polyphosphate were prepared. The influence of blending LDPE with poly(ethylene vinyl acetate) (EVA) as well as the effects of a coadditive such as talc on flammability was investigated. Chemical crosslinking by dicumyl peroxide and crosslinking by ionizing radiation from an electron‐beam accelerator were both used and compared. An increase in the limiting oxygen index (LOI) was found by the partial replacement of LDPE with EVA. The effect of talc on the flammability depended on the amount of talc in the formulations. The addition of a small amount of talc increased LOI and reduced smoke during cone calorimeter measurements. A higher amount of talc led to a decrease in the LOI values. Formulations crosslinked by ionizing radiation yielded lower LOI values than chemically crosslinked formulations. This could be attributed to the use of trimethylolpropane triacrylate as a crosslinking coagent in formulations crosslinked by ionizing radiation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
[8+2] and [8+3] Cyclization Reactions of Alkenyl Carbenes and 8‐Azaheptafulvenes: Direct Access to Tetrahydro‐1‐azaazulene and Cyclohepta[b]pyridinone Derivatives
Authors: Barluenga José , García‐Rodríguez Jaime , Martínez Silvia , Suárez‐Sobrino Ángel L. , Tomás Miguel
Published: March 2008

The reactivity of Fischer alkenyl carbenes toward 8‐azaheptafulvenes is examined. Alkenyl carbenes react with 8‐azaheptafulvenes with complete regio‐ and stereoselectivity through formal [8+3] and [8+2] heterocyclization reactions, which show an unprecedented dependence on the Cβ substituent at the alkenyl carbene complex. Thus, the formal [8+3] heterocyclization reaction is completely favored in carbene complexes that bear a coordinating moiety to give tetrahydrocyclohepta[b]pyridin‐2‐ones. Otherwise, alkenyl carbenes that lack appropriate coordinating groups undergo a formal [8+2] cyclization with 8‐azaheptafulvenes to give compounds that bear a tetrahydroazaazulene structure. A likely mechanism for these reactions would follow well‐established models and would involve a 1,4‐addition/cyclization in the case of the [8+2] cyclization or a 1,2‐addition/[1,2] shift–metal‐promoted cyclization for the [8+3] reaction. The presence of a coordinating moiety in the carbene would favor the [1,2] metal shift through transition‐state stabilization to lead to the [8+3] product. All these processes provide an entry into the tetrahydroazaazulene and cycloheptapyridone frameworks present in the structure of biologically active molecules.
Intramolecular Diamination of Alkenes with Palladium(II)/Copper(II) Bromide and IPy2BF4: The Role of Halogenated Intermediates
Authors: Muñiz Kilian , Hövelmann Claas H. , Campos‐Gómez Esther , Barluenga José , González José M. , Streuff Jan , Nieger Martin
Published: March 2008

The oxidative intramolecular diamination of alkenes with tethered ureas and related groups as the nitrogen source has been investigated both with the iodonium reagent IPy2BF4 (Py=pyridine) and under palladium catalysis in the presence of copper(II) bromide as a reoxidant. For terminal alkenes, the two procedures enable selective and high‐yielding transformations. Studies with deuterated material led to the conclusion that the reactions proceed through different stereochemical pathways. An advanced protocol for palladium‐catalyzed diamination through six‐membered‐ring annulation was also developed, and the first examples of the intramolecular diamination of internal alkenes are described. In this case, the same stereochemical outcome was observed for the iodonium‐promoted and palladium‐catalyzed transformations. On this basis, it was possible to determine the importance of aminohalogenated intermediates in both diamination reactions. Overall, the disclosed procedures broaden significantly the synthetic applicability of the oxidative intramolecular diamination of alkenes.
High‐throughput screening of chromatographic separations: I. Method development and column modeling
Authors: Coffman Jonathan L. , Kramarczyk Jack F. , Kelley Brian D.
Published: March 2008

The development of purification processes for protein biopharmaceuticals is challenging due to compressed development timelines, long experimental times, and the need to survey a large parameter space. Typical methods for development of a chromatography step evaluate several dozen chromatographic column runs to optimize the conditions. An efficient batch‐binding method of screening chromatographic purification conditions in a 96‐well format with a robotic liquid‐handling system is described and evaluated. The system dispenses slurries of chromatographic resins into filter plates, which are then equilibrated, loaded with protein, washed and eluted. This paper evaluates factors influencing the performance of this high‐throughput screening technique, including the reproducibility of the aliquotted resin volume, the contact time of the solution and resin during mixing, and the volume of liquid carried over in the resin bed after centrifugal evacuation. These factors led to the optimization of a batch‐binding technique utilizing either 50 or 100 µL of resin in each well, the selection of an industrially relevant incubation time of 20 min, and the quantitation of the hold‐up volume, which was as much as one quarter of the total volume added to each well. The results from the batch‐binding method compared favorably to chromatographic column separation steps for a cGMP protein purification process utilizing both hydrophobic interaction and anion‐exchange steps. These high‐throughput screening tools can be combined with additional studies on the kinetics and thermodynamics of protein–resin interactions to provide fundamental information which is useful for defining and optimizing chromatographic separations steps. Biotechnol. Bioeng. 2008;100: 605–618. © 2008 Wiley Periodicals, Inc.
High‐throughput screening of chromatographic separations: II. Hydrophobic interaction
Authors: Kramarczyk Jack F. , Kelley Brian D. , Coffman Jonathan L.
Published: March 2008

A high‐throughput screen (HTS) was developed to evaluate the selectivity of various hydrophobic interaction chromatography (HIC) resins for separating a mAb from aggregate species. Prior to the resin screen, the solubility of the protein was assessed to determine the allowable HIC operating region by examining 384 combinations of pH, salt, and protein concentration. The resin screen then incorporated 480 batch‐binding and elution conditions with eight HIC resins in combination with six salts. The results from the screen were reproducible, and demonstrated quantitative recovery of the mAb and aggregate. The translation of the HTS batch‐binding data to lab‐scale chromatography columns was tested for four conditions spanning the range of product binding and selectivity. After accounting for the higher number of theoretical plates in the columns, the purity and recovery of the lab‐scale column runs agreed with the HTS results demonstrating the predictive power of the filterplate system. The HTS data were further analyzed by the calculation of pertinent thermodynamic parameters such as the partition coefficient, KP, and the separation factor, α. The separation factor was used to rank the purification capabilities of the resin and salt conditions explored. Biotechnol. Bioeng. 2008;100: 707–720. © 2008 Wiley Periodicals, Inc.
Implementation and assessment of a molecular biology and bioinformatics undergraduate degree program
Authors: Pham Daphne Q.‐D. , Higgs David C. , Statham Anne , Schleiter Mary Kay
Published: March 2008

The Department of Biological Sciences at the University of Wisconsin‐Parkside has developed and implemented an innovative, multidisciplinary undergraduate curriculum in Molecular Biology and Bioinformatics (MBB). The objective of the MBB program is to give students a hands‐on facility with molecular biology theories and laboratory techniques, an understanding of mathematical and physical concepts, an ability to apply these concepts to MBB, and a proficiency with the computational tools and skills related to bioinformatics. We hypothesized that a greater exposure to bioinformatics methods, more rigorous requirements in math and computer science, and a constant demand for integrating information in hands‐on laboratory courses would help students develop better analytical skills. Indeed, the assessment data support these predictions. Interestingly, 80% of MBB majors apply and are accepted into graduate schools.
Biochemical thermodynamics under near physiological conditions
Authors: Méndez Eduardo
Published: March 2008

The recommendations for nomenclature and tables in Biochemical Thermodynamics approved by IUBMB and IUPAC in 1994 can be easily introduced after the chemical thermodynamic formalism. Substitution of the usual standard thermodynamic properties by the transformed ones in the thermodynamic equations, and the use of appropriate thermodynamic tables can be easily employed in the study of the energetics of biochemical equations, regulatory systems, and metabolic pathways under near physiological conditions.
Use of molecular dynamics data in biochemistry courses
Authors: Mazzé Fernanda M. , Fuzo Carlos A. , Degrève Léo , Ciancaglini Pietro
Published: March 2008

The aim of this manuscript is to explain the application of an amphipathy scale obtained from molecular dynamics simulations and to demonstrate how it can be useful in the protein structure field. It is shown that this scale is easy to be used with the advantage of revealing domains of transmembrane α‐helix of proteins without the need of knowing anything besides the protein primary structure. In addition, it allows the students to correlate concepts of protein structure and function, energy minimization, molecular dynamics simulations, and protein location.
A laboratory exercise to determine human ABO blood type by noninvasive methods
Authors: Martin Michael P. , Detzel Stephen M.
Published: March 2008

Analysis of single‐nucleotide polymorphisms and their association with diseases and nondisease phenotypes is of growing importance in human biology studies. In this laboratory exercise, students determine the genetic basis for their ABO blood type; however, no blood is drawn. Students isolate genomic DNA from buccal mucosa cells that are present in saliva and analyze the DNA on an agarose gel. Subsequently, this DNA is used as a PCR template to amplify exons 6 and 7 of the gene that determines the human ABO phenotype. These PCR products are digested and run on agarose gels to examine the restriction fragment length polymorphisms. A deletion in the O1 allele converts the BstE II site in exon 6 into a Kpn I site, and this feature is used to determine the presence of O1 alleles. The pattern of exon 7 digest products allows students to distinguish among four other common ABO alleles: A1, A2, B, and O2. This exercise introduces students to commonly used molecular biology techniques, such as genomic DNA isolation, PCR, gel electrophoresis, and restriction digests.
A case of extensive hyperostosis frontalis interna in an 87‐year‐old female human cadaver
Authors: Talarico Ernest F. , Prather Andrew D. , Hardt Kevin D.
Published: March 2008

Hyperostosis frontalis interna (HFI) is a condition that involves thickening of the inner surface of the frontal bone with sparing of the midline. Little is known about the etiology and clinical presentation of HFI. We report unusual findings in a woman with extensive Type D hyperostosis of the frontal bone and a large hyperostotic nodule in the parietal bone with impingement on the precentral gyrus, distinguishing this from the common form of HFI. The scalp was dissected from the cranial vault, and the calvaria and brain were removed and digitally imaged. Bone specimens were embedded in methyl methacrylate plastic, sectioned, and stained using the Von Kossa Method with MacNeal's tetrachrome. Medical records were reviewed, and additional history was obtained through interviews with the donor's family. The calvaria had extensive, bilateral thickening of the frontal bone with irregular topography and clearly demarcated borders. The dura was adherent to all hyperostotic regions. A 3.5‐cm nodule was visible on the inner table of the left parietal bone. The dura and cerebrum showed compression in this region, but it was unclear if this resulted in clinical ramifications. Microscopic analysis revealed a larger proportion of cancellous bone was present in regions of macroscopic hyperostosis. Quantitative analysis of sections through areas of gross hyperostosis demonstrated a lower proportion of lamellar bone than in the control. The patient exhibited symptoms that have been correlated to HFI in previous studies. We suggest that the HFI disease process was responsible for the manifestation of these symptoms in this patient. Clin. Anat. 21:259–268, 2008. © 2008 Wiley‐Liss, Inc.
Synthesis of Selenocysteine and Selenomethionine Derivatives from Sulfur‐Containing Amino Acids
Authors: Iwaoka Michio , Ooka Ryuta , Nakazato Toshifumi , Yoshida Sari , Oishi Sadahiro
Published: March 2008

Selenium‐containing amino acids have attracted increasing interest from view points of the importance as active centers of several selenoenzymes, the biological synthesis, the metabolism, and the use for structure determination of proteins. In this article, our recent progresses in the transformation from sulfur‐containing amino acids to selenocysteine (SeCys) and selenomethionine (SeMet) derivatives are reviewed along with the surveys of general organic methodologies for the synthesis of SeCys and SeMet derivatives in the literature. The S→Se modification (i.e., the chemical atomic mutation) would be a useful approach to peptide synthesis involving selenoamino acid residues.
Synthesis of Analogues of Flazin, in Particular, Flazinamide, as Promising Anti‐HIV Agents
Authors: Tang Jian‐Guo , Wang Yun‐Hua , Wang Rui‐Rui , Dong Ze‐Jun , Yang Liu‐Meng , Zheng Yong‐Tang , Liu Ji‐Kai
Published: March 2008

Flazin isolated from the fruiting bodies of Suillus granulatus was found to possess weak anti‐HIV activity (EC50=2.36 μM, TI=12.1). To establish a SAR study, 46 flazin analogues were synthesized, and their anti‐HIV activities were evaluated in vitro. Among them, flazinamide (9a) showed the most potent activity with an EC50 value of 0.38 μM and a TI value of 312.0. The results suggested that appropriate substituents at positions 3, 1′, and 5′ of flazin might play a crucial role in determining their anti‐HIV activities, and that flazinamide can be considered as a promising, readily available anti‐HIV agent.
Phytochemical Analysis and in vitro Antiviral Activities of the Essential Oils of Seven Lebanon Species
Authors: Loizzo Monica R. , Saab Antoine M. , Tundis Rosa , Statti Giancarlo A. , Menichini Francesco , Lampronti Ilaria , Gambari Roberto , Cinatl Jindrich , Doerr Hans Wilhelm
Published: March 2008

The chemical composition of the essential oils of Laurus nobilis, Juniperus oxycedrus ssp. oxycedrus, Thuja orientalis, Cupressus sempervirens ssp. pyramidalis, Pistacia palaestina, Salvia officinalis, and Satureja thymbra was determined by GC/MS analysis. Essential oils have been evaluated for their inhibitory activity against SARS‐CoV and HSV‐1 replication in vitro by visually scoring of the virus‐induced cytopathogenic effect post‐infection. L. nobilis oil exerted an interesting activity against SARS‐CoV with an IC50 value of 120 μg/ml and a selectivity index (SI) of 4.16. This oil was characterized by the presence of β‐ocimene, 1,8‐cineole, α‐pinene, and β‐pinene as the main constituents. J. oxycedrus ssp. oxycedrus oil, in which α‐pinene and β‐myrcene were the major constituents, revealed antiviral activity against HSV‐1 with an IC50 value of 200 μg/ml and a SI of 5.