bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlations among Extinction Risks Assessed by Different Systems of Threatened Species Categorization
Authors: O'GRADY JULIAN J. , BURGMAN MARK A. , KEITH DAVID A. , MASTER LAWRENCE L. , ANDELMAN SANDY J. , BROOK BARRY W. , HAMMERSON GEOFFREY A. , REGAN TRACEY , FRANKHAM RICHARD
Published: December 2004

Abstract: Many different systems are used to assess levels of threat faced by species. Prominent ones are those used by the World Conservation Union, NatureServe, and the Florida Game and Freshwater Fish Commission (now the Florida Fish and Wildlife Conservation Commission). These systems assign taxa a threat ranking by assessing their demographic and ecological characteristics. These threat rankings support the legislative protection of species and guide the placement of conservation programs in order of priority. It is not known, however, whether these assessment systems rank species in a similar order. To resolve this issue, we assessed 55 mainly vertebrate taxa with widely differing life histories under each of these systems and determined the rank correlations among them. Moderate, significant positive correlations were seen among the threat rankings provided by the three systems (correlations 0.58–0.69). Further, the threat rankings for taxa obtained using these systems were significantly correlated to their rankings based on predicted probability of extinction within 100 years as determined by population viability analysis (correlations 0.28–0.37). The different categorization systems, then, yield related but not identical threat rankings, and these rankings are associated with predicted extinction risk.
Catastrophic Decline in Mollusc Diversity in Eastern Tasmania and Its Concurrence with Shellfish Fisheries
Authors: EDGAR G.J. , SAMSON C.R.
Published: December 2004

Abstract: 
We used historical patterns of deposition of mollusc shells to infer changes to inshore benthic assemblages in the southeastern Tasmanian region over the past 120 years. We identified and counted shells in slices embedded within 1m long 210Pb‐dated sediment cores were collected at 13 sites in water depths of 8–16 m. Declines in mollusc species richness and shell production occurred during the past century at all sites studied, with a mean decline per 5‐cm sediment slice from 21 species in 1890 to 7 species in 1990 and in shell abundance from 150 to 30 individuals over the same period. The time course of decline notably corresponded with the history of the scallop dredge fishery, presumably either because scallop dredging caused general declines in populations of mollusc species or because other factors caused a catastrophic regional decline in molluscs that included scallops. As a consequence, the fishery was forced to close. Of major concern is that losses had not previously been recognized but extended throughout the 100‐km coastal span of the study. Given that fishing and other anthropogenic impacts, as well as a lack of observational data, are virtually ubiquitous for the coastal zone, major recent losses in mollusc biodiversity may be globally widespread but have gone unnoticed.
Changes in Forest Use Value through Ecological Succession and Their Implications for Land Management in the Peruvian Amazon
Authors: GAVIN MICHAEL C.
Published: December 2004

Abstract: 
Research on local use values of forests across an ecological succession informs land‐use decisions and conservation planning. I evaluated use values of three age classes of secondary forest: fallow fields (<5 years old, $8.20/ha/year), young secondary forest (5–20 years old, $20.60/ha/year), and old secondary forest (>20 years old, $6.80/ha/year). I quantified daily forest product use and calculated use values in dollars per hectare per year for three communities in the northern Peruvian Amazon. I made three comparisons between forest types: number of useful species, value based on different use categories, and overall use values. Old secondary forest had the greatest number of total species present and species collected. Wood, food, and medicine were the three most valuable use categories. The value different families extracted from local forests varied enormously, but median forest values were lower for all forest types than potential gains from agricultural land use (e.g., coffee $167/ha/year). Values of different‐aged stands on privately owned lands in two communities did not differ significantly, whereas in the third community, young secondary forest had a significantly greater value than other forest types. Old secondary forests were the most valuable source of wood products, and wood was the only use category in which there was any difference in the value of products extracted from different‐aged forest stands. The value of all three forest types on open‐access (nonprivate) lands was minimal (mean in each forest type, $0/ha/year). Local people can utilize the valuation results to develop land‐use strategies that balance forest product use, agricultural productivity, and biodiversity conservation.
Response of Savanna Fire Regimes to Changing Fire‐Management Policies in a Large African National Park
Authors: VAN WILGEN B.W. , GOVENDER N. , BIGGS H.C. , NTSALA D. , FUNDA X.N.
Published: December 2004

Abstract: 
Approaches to fire management in the savanna ecosystems of the 2‐million ha Kruger National Park, South Africa, have changed several times over the past six decades. These approaches have included regular and flexible prescribed burning on fixed areas and a policy that sought to establish a lightning‐dominated fire regime. We sought to establish whether changes in management induced the desired variability in fire regimes over a large area. We used a spatial database of information on all fires in the park between 1957 and 2002 to determine elements of the fire regime associated with each management policy. The area that burned in any given year was independent of the management approach and was strongly related to rainfall (and therefore grass fuels) in the preceding 2 years. On the other hand, management did affect the spatial heterogeneity of fires and their seasonal distribution. Heterogeneity was higher at all scales during the era of prescribed burning, compared with the lightning‐fire interval. The lightning‐fire interval also resulted in a greater proportion (72% vs. 38%) of the area burning in the dry season. Mean fire‐return intervals varied between 5.6 and 7.3 years, and variability in fire‐return intervals was strongly influenced by the sequencing of annual rainfall rather than by management. The attempt at creating a lightning‐dominated fire regime failed because most fires were ignited by humans, and the policy has been replaced by a more pragmatic approach that combines flexible prescribed burning with lightning‐ignited fires.
Influence of Temporal Scale of Sampling on Detection of Relationships between Invasive Plants and the Diversity Patterns of Plants and Butterflies
Authors: NALLY RALPH MAC , FLEISHMAN ERICA , MURPHY DENNIS D.
Published: December 2004

Abstract: Monitoring is a major component of restoration efforts and adaptive management. But monitoring is often neglected because it can be expensive and time‐consuming. Accordingly, it is valuable to determine whether the temporal extent of sampling alters the validity of inferences about the response of diversity measures to environmental variables affected by restoration actions. Non‐native species alter ecosystems in undesirable ways, frequently homogenizing flora and fauna and extirpating local populations of native species. In the Mojave Desert, invasion of salt‐cedar (Tamarix ramosissimaLedeb.) and human efforts to eradicate salt‐cedar have altered vegetation structure, vegetation composition, and some measures of faunal diversity. We examined whether similar inferences about relationships between plants and butterflies in the Muddy River drainage (Nevada, U.S.A.) could have been obtained by sampling less intensively (fewer visits per site over the same period of time) or less extensively (equal frequency of visits but over a more limited period of time). We also tested whether rank order of butterfly species with respect to occurrence rate (proportion of sites occupied) would be reflected accurately in temporal subsamples. Temporal subsampling did not lead to erroneous inferences about the relative importance of six vegetation‐based predictor variables on the species richness of butterflies. Regardless of the temporal scale of sampling, the species composition of butterflies was more similar in sites with similar species composition of plants. The rank order of occurrence of butterfly species in the temporal subsamples was highly correlated with the rank order of species occurrence in the full data set. Thus, similar inferences about associations between vegetation and butterflies and about relative occurrence rates of individual species of butterflies could be obtained by less intensive or extensive temporal sampling. If compromises between temporal intensity and extent of sampling must be made, our results suggest that maximizing temporal extent will better capture variation in biotic interactions and species occurrence.
Linkage of Conservation Activity to Trends in the U.S. Economy
Authors: PERGAMS OLIVER R. W. , CZECH BRIAN , HANEY J. CHRISTOPHER , NYBERG DENNIS
Published: December 2004

Abstract: 
As an economy grows, natural capital such as timber, soil, and water is reallocated to the human economy. This conflict between economic growth and biodiversity conservation creates a conundrum for conservation biologists because traditional forms of conservation action require money. We hypothesize that conservation spending in the United States is highly correlated with income and wealth, and we tested whether selected proxies for U.S. conservation activity could be predicted by U.S. economic indicators over time scales of 7–71 years. Stock market indexes (Dow Jones Industrial Average, Standard & Poor's 500 Index), gross domestic product (GDP), and personal income (PI) explained as much as 99% of annual variation in total revenue (including contributions) to four large nongovernmental organizations (NGOs), the World Wildlife Fund, Sierra Club, Environmental Defense, The Nature Conservancy. These broad economic indicators also explained as much as 96% of the annual number of university conservation programs, 83% of membership in professional conservation organizations (Natural Areas Association, Society for Conservation Biology), 93% of national park visitation, and 99+% of national park acreage. In most analyses, the income variables GDP and PI explained more variation in conservation activity than did either of the stock‐market wealth variables. After long‐term growth was removed from the time series, changes in revenues to the four NGOs combined were significantly correlated with GDP but not PI over the short term. Short‐term variation in park acreage was significantly correlated with GDP and PI but lagged both by 3 years. Using linear models based on GDP, we predicted increases of 2.3% in 2003 cumulative NGO revenues and 1.0% in 2006 acreage owned by the National Park Service. The conservation activity parameters we measured may exhibit positive trends even in the face of declining biodiversity, but biodiversity conservation will ultimately require the cessation of economic growth. The challenge to the conservation biology community is to retain a significant presence during and after the cessation of growth.
When Good Animals Love Bad Habitats: Ecological Traps and the Conservation of Animal Populations
Authors: BATTIN JAMES
Published: December 2004

Abstract: The concept of the ecological trap, a low‐quality habitat that animals prefer over other available habitats of higher quality, has appeared in the ecological literature irregularly for over 30 years, but the topic has received relatively little attention, and evidence for traps remains largely anecdotal. Recently, however, the ecological trap concept has been the subject of a flurry of theoretical activity that is likely to raise its profile substantially, particularly in conservation biology. Ecological trap theory suggests that, under most circumstances, the presence of a trap in a landscape will drive a local population to extinction. A number of empirical studies, almost all of birds, suggest the existence of traps and demonstrate the difficulties of recognizing them in the field. Evidence for ecological traps has primarily been found in habitats modified by human activities, either directly (e.g., through the mowing of grassland birds' nests) or indirectly (e.g., via human‐mediated invasion of exotic species), but some studies suggest that traps may occur even in relatively pristine areas. Taken together, these theoretical and empirical results suggest that traps may be relatively common in rapidly changing landscapes. It is therefore important for conservation biologists to be able to identify traps and differentiate them from sinks. Commonly employed approaches for population modeling, which tend to assume a source‐sink framework and do not consider habitat selection explicitly, may introduce faulty assumptions that mask the effects of ecological traps and lead to overly optimistic predictions about population persistence. Given the potentially dire consequences of ecological traps and the accumulating evidence for their existence, greater attention from the community of conservation biologists is warranted. In particular, it is important for conservation biologists and managers to incorporate into conservation planning an explicit understanding of the relationship between habitat selection and habitat quality.
Understanding the Causes of Disease in European Freshwater Crayfish
Authors: EDGERTON BRETT F. , HENTTONEN PAULA , JUSSILA JAPO , MANNONEN ARI , PAASONEN PIETARI , TAUGBØL TROND , EDSMAN LENNART , SOUTY‐GROSSET CATHERINE
Published: December 2004

Abstract: 
Native European freshwater crayfish (Astacida, Decapoda) are under severe pressure from habitat alteration, the introduction of nonindigenous species, and epizootic disease. Crayfish plague, an acute disease of freshwater crayfish caused by the fungus‐like agent Aphanomyces astaci, was introduced into Europe in the mid‐nineteenth century and is responsible for ongoing widespread epizootic mortality in native European populations. We reviewed recent developments and current practices in the field of crayfish pathology. The severity of crayfish plague has resulted in an overemphasis on it. Diagnostic methods for detecting fungi and fungal‐like agents, and sometimes culturing them, are frequently the sole techniques used to investigate disease outbreaks in European freshwater crayfish. Consequently, the causes of a significant proportion of outbreaks are undetermined. Pathogen groups well known for causing disease in other crustaceans, such as viruses and rickettsia‐like organisms, are poorly understood or unknown in European freshwater crayfish. Moreover, the pathogenic significance of some long‐known pathogens of European freshwater crayfish remains obscure. For effective management of this culturally significant and threatened resource, there is an urgent need for researchers, diagnosticians, and resource managers to address the issue of disease in European freshwater crayfish from a broader perspective than has been applied previously.
From Red Lists to Species of Conservation Concern
Authors: KELLER VERENA , BOLLMANN KURT
Published: December 2004

Abstract: National red lists of threatened animal and plant species prepared according to the criteria of the World Conservation Union (IUCN) adequately reflect the extinction risk of species within a country but cannot be used directly to set conservation priorities. In particular, the significance of national populations for the conservation of the species as a whole is not taken into account. We present a procedure that can be used to assess national responsibility based on the national red‐list status of a species, the international importance of the national population, and the species' “historical rarity” status. We distinguished five responsibility classes for breeding birds: B1, threatened species with internationally important populations in Switzerland; B2, threatened species with internationally less important populations; B3, nonthreatened species with internationally important populations; B4, nonthreatened species with internationally less important populations; and B5, species that have never been common in Switzerland. Two responsibility classes were distinguished for birds occurring in Switzerland as visitors: G1, species with large concentrations in Switzerland and an unfavorable conservation status in Europe, and G2, species with large concentrations in Switzerland and a favorable conservation status in Europe. Two additional classes (G3 and G4) for visiting species occurring in internationally less important numbers are possible but were not analyzed in detail. Responsibility classes B1, B2, B3, G1, and G2 were defined as species of national conservation concern. We developed the method for birds in Switzerland, but it can be used in other countries and for other taxonomic groups as well. It is particularly suitable where national red lists are established according to IUCN guidelines.
Measures for assessing architectural speech security (privacy) of closed offices and meeting rooms
Authors: Gover Bradford N. , Bradley John S.
Published: December 2004

Objective measures were investigated as predictors of the speech security of closed offices and rooms. A new signal-to-noise type measure is shown to be a superior indicator for security than existing measures such as the Articulation Index, the Speech Intelligibility Index, the ratio of the loudness of speech to that of noise, and the A-weighted level difference of speech and noise. This new measure is a weighted sum of clipped one-third-octave-band signal-to-noise ratios; various weightings and clipping levels are explored. Listening tests had 19 subjects rate the audibility and intelligibility of 500 English sentences, filtered to simulate transmission through various wall constructions, and presented along with background noise. The results of the tests indicate that the new measure is highly correlated with sentence intelligibility scores and also with three security thresholds: the threshold of intelligibility (below which speech is unintelligible), the threshold of cadence (below which the cadence of speech is inaudible), and the threshold of audibility (below which speech is inaudible). The ratio of the loudness of speech to that of noise, and simple A-weighted level differences are both shown to be well correlated with these latter two thresholds (cadence and audibility), but not well correlated with intelligibility.
Explicit secular equations for piezoacoustic surface waves: Shear-horizontal modes
Authors: Collet Bernard , Destrade Michel
Published: December 2004

Attention is given to surface waves of shear-horizontal modes in piezoelectric crystals permitting the decoupling between an elastic in-plane Rayleigh wave and a piezoacoustic antiplane Bleustein–Gulyaev wave. Specifically, the crystals possess 4̄ symmetry (inclusive of 4̄2m, 4̄3m, and 23 classes) and the boundary is any plane containing the normal to a symmetry plane (rotated Y cuts about the Z axis). The secular equation is obtained explicitly as a polynomial not only for the metallized boundary condition but, in contrast to previous studies on the subject, also for other types of boundary conditions. For the metallized surface problem, the secular equation is a quadratic in the squared wave speed; for the unmetallized surface problem, it is a sextic in the squared wave speed; for the thin conducting boundary problem, it is of degree 16 in the speed. The relevant root of the secular equation can be identified and the complete solution is then found (attenuation factors, field profiles, etc.). The influences of the cut angle and of the conductance of the adjoining medium are illustrated numerically for AlAs (4̄3m), BaLaGa3O7 (4̄2m), and Bi12GeO20 (23). Indications are given on how to apply the method to crystals with 222 symmetry.
Theoretical gas body pulsation in relation to empirical gas-body destabilization and to cell membrane damage thresholds
Authors: Miller Douglas L. , Dou Chunyan
Published: December 2004

Contrast agent gas bodies attached to phagocytic monolayer cells pulsate in response to ultrasound exposure and damage the cells above thresholds, which increase in proportion to frequency. This study considered the physical basis for the thresholds and their frequency dependence. Theory for the pulsation was evaluated using empirical pulse waveforms acquired at thresholds for 1.0, 2.25, 3.5, 5.0, 7.5, and 10 MHz. For optimum-sized gas bodies, the amplitudes calculated at the thresholds were about 11% of the initial radii. At the cell membrane damage thresholds, theoretical negative shell stresses were approximately constant with frequency at about 50 MPa. This stress appears to be sufficient to induce failure of the shell, and gas body destabilization was confirmed by increases in transmission of ultrasound pulses through the monolayer and by microscopically-observed shrinkage of the gas bodies. A model of acoustic microstreaming was used to calculate the shear stress during the pulses. The maximum shear stress increased from about 1500 to 4500 Pa from 1 to 10 MHz, sufficient for the cell membrane damage. This theoretical analysis shows that both the gas body destabilization and the cell membrane damage could be expected at similar peak rarefactional pressure amplitudes, with thresholds having the observed proportionality to frequency.
Evidence for a Role of the Regulator of G-Protein Signaling Protein CPRGS-1 in Gα Subunit CPG-1-Mediated Regulation of Fungal Virulence, Conidiation, and Hydrophobin Synthesis in the Chestnut Blight Fungus
Cryphonectria parasitica
Authors: Segers Gerrit C. , Regier Jerome C. , Nuss Donald. L.
Published: December 2004

We previously reported that the chestnut blight fungus
Cryphonectria parasitica
expresses at least three G-protein α subunits and that Gα subunit CPG-1 is essential for regulated growth, pigmentation, sporulation, and virulence. We now report the cloning and characterization of a
C. parasitica
regulator of G-protein signaling (RGS) protein, CPRGS-1. The phylogenetic relationship of CPRGS-1 to orthologs from other fungi was inferred and found to be generally concordant with species relationships based on 18S ribosomal sequences and on morphology. However, Hemiascomycotine RGS branch lengths in particular were longer than for their 18S sequence counterparts, which correlates with functional diversification in the signaling pathway. Deletion of
cprgs-1
resulted in reduced growth, sparse aerial mycelium, and loss of pigmentation, sporulation, and virulence. Disruption of
cprgs-1
was also accompanied by a severe posttranscriptional reduction in accumulation of CPG-1 and Gβ subunit CPGB-1 and severely reduced expression of the hydrophobin-encoding gene cryparin. The changes in phenotype, cryparin expression, and CPGB-1 accumulation resulting from
cprgs-1
gene deletion were also observed in a strain containing a mutationally activated copy of CPG-1 but not in strains containing constitutively activated mutant alleles of the other two identified Gα subunits, CPG-2 and CPG-3. Furthermore,
cprgs-1
transcript levels were increased in the activated CPG-1 strain but were unaltered in activated CPG-2 and CPG-3 strains. The results strongly suggest that CPRGS-1 is involved in regulation of Gα subunit CPG-1-mediated signaling and establish a role for a RGS protein in the modulation of virulence, conidiation, and hydrophobin synthesis in a plant pathogenic fungus.
BINDING ENERGY OF THE SELF-TRAPPED MAGNETIC POLARON: EFFECT OF THE INTRA-SUBLATTICE ELECTRON HOPPING
Authors: THULASI S. , SATPATHY S.
Published: December 2004

We study the energetic stability of the self-trapped magnetic polaron in an antiferromagnetic lattice of localized spins, including the effects of the intra-sublattice hopping which allows electron transfer within the same magnetic sublattice. The model consists of an itinerant electron moving in a one-dimensional antiferromagnetic lattice of localized spins. In addition to the first and the second neighbor electron hopping, terms describing the superexchange between the localized spins as well as the Hund's-rule coupling between the electron and the localized spins are included in the model Hamiltonian. The ground-state energy of the self-trapped polaron with the resulting ferromagnetic core region is compared with the energy of the propagating state in the antiferromagnetic lattice. We find the magnetic polaron to be self-trapped for all values of the Hamiltonian parameters, although the intra-sublattice hopping substantially reduces the polaron binding energy.
STOCHASTIC MODELS OF LAGRANGIAN ACCELERATION OF FLUID PARTICLE IN DEVELOPED TURBULENCE
Authors: ARINGAZIN A. K. , MAZHITOV M. I.
Published: December 2004

Modeling statistical properties of motion of a Lagrangian particle advected by a high-Reynolds-number flow is of much practical interest and complement traditional studies of turbulence made in Eulerian framework. The strong and nonlocal character of Lagrangian particle coupling due to pressure effects makes the main obstacle to derive turbulence statistics from the three-dimensional Navier–Stokes equation; motion of a single fluid-particle is strongly correlated to that of the other particles. Recent breakthrough Lagrangian experiments with high resolution of Kolmogorov scale have motivated growing interest to acceleration of a fluid particle. Experimental stationary statistics of Lagrangian acceleration conditioned on Lagrangian velocity reveals essential dependence of the acceleration variance upon the velocity. This is confirmed by direct numerical simulations. Lagrangian intermittency is considerably stronger than the Eulerian one. Statistics of Lagrangian acceleration depends on Reynolds number. In this review we present description of new simple models of Lagrangian acceleration that enable data analysis and some advance in phenomenological study of the Lagrangian single-particle dynamics. Simple Lagrangian stochastic modeling by Langevin-type dynamical equations is one the widely used tools. The models are aimed particularly to describe the observed highly non-Gaussian conditional and unconditional acceleration distributions. Stochastic one-dimensional toy models capture main features of the observed stationary statistics of acceleration. We review various models and focus in a more detail on the model which has some deductive support from the Navier–Stokes equation. Comparative analysis on the basis of the experimental data and direct numerical simulations is made.
RGD-modified liposomes targeted to activated platelets as a potential vascular drug delivery system
Authors: Gupta Anirban , Huang Guofeng , Lestini Brian , Sagnella Sharon , Kottke-Marchant Kandice , Marchant Roger
Published: December 2004

Local drug delivery has become an important treatment modality for the prevention of thrombotic events following coronary angioplasty. In this study, we investigate the ability of liposomes bearing surface conjugated linear Arg-Gly-Asp (RGD) peptide (GSSSGRGD SPA) moieties to target and bind activated platelets, and the effect of such RGD-modified liposomes on platelet activation and aggregation. The binding of RGD-liposomes to human platelets was assessed by fluorescence microscopy,phase contrast microscopy and flow cytometry. The effect of RGDmodified liposomes on platelet activation and aggregation was investigated in vitro, with and without platelet agonists. RGD-liposomes were found to bind activated platelets at levels significantly greater than the control RGE-liposomes.The RGD-liposomes did not exhibit any statistically significant effect on platelet activation or aggregation.The results demonstrate the ability of the RGD-modified liposomes to target and bind activated platelets without causing significant platelet aggregation and suggests a feasible way for the development of a platelet-targeted anti-thrombogenic drug delivery system. Furthermore, the approach can be extended to the development of liposomes for other vascular targets, for application in drug delivery or gene therapy.
Elites, single parties and political decision making in Southern European dictatorships: the Salazar, Franco and Mussolini regimes
Authors: Costa Pinto António
Published: December 2004

Awareness of the interaction between the single party, the government, the State apparatus and civil society appears fundamental if we are to achieve an understanding of the different ways in which the various dictatorships of the fascist era functioned. The party and its ancillary
organisations were not simply parallel institutions: they attempted to gain control of the bureaucracy and select the governing elite – forcing some dictatorships towards an unstable equilibrium in the process, even while they were the central agents for the creation and maintenance
of the leader’s charismatic authority. These articles focus on an analysis of the gradations of these tensions, that may be illustrated by the eventual emergence of a weaker or stronger ‘dualism of power’ that appears to be the determining factor in explanations for the typological
and classificatory variations used to qualify those dictatorships that have been historically associated with fascism and which have been variously defined as ‘authoritarian’ and ‘totalitarian’, or as ‘authoritarian’ and ‘fascist’. It is in this
perspective that we will study three dictatorships that have each been associated with European fascism: Portuguese Salazarism, Spanish Francoism and Italian Fascism.
Health worker (internal customer) satisfaction and motivation in the public sector in Ghana
Authors: Agyepong Irene Akua , Anafi Patricia , Asiamah Ebenezer , Ansah Evelyn K. , Ashon Daniel A. , Narh‐Dometey Christiana
Published: December 2004

This paper describes factors affecting health worker motivation and satisfaction in the public sector in Ghana. The data are from a survey of public sector health care providers carried out in January 2002 and repeated in August 2003 using an interviewer administered structured questionnaire. It is part of a continuous quality improvement (CQI) effort in the health sector in the Greater Accra region of Ghana. Workplace obstacles identified that caused dissatisfaction and de‐motivated staff in order of the most frequently mentioned were low salaries such that obtaining basic necessities of daily living becomes a problem; lack of essential equipment, tools and supplies to work with; delayed promotions; difficulties and inconveniences with transportation to work; staff shortages; housing, additional duty allowances and in‐service (continuous) training. Others included children's education, vehicles to work with such as ambulances and pickups, staff transfer procedures, staff pre‐service education inadequate for job requirements, and the effect of the job on family and other social factors. There were some differences in the percentages of staff selecting a given workplace obstacle between the purely rural districts, the highly urbanized Accra metropolis and the districts that were a mixture of urbanized and rural. It is unlikely that the Ghana Health Service can provide high quality of care to its end users (external customers) if workplace obstacles that de‐motivate staff (internal customers) and negatively influence their performance are not properly recognized and addressed as a complex of inter‐related problems producing a common result—dissatisfied poorly motivated staff and resulting poor quality services. Copyright © 2004 John Wiley & Sons, Ltd.
A validated liquid chromatographic/tandem mass spectrometric method for the determination of phencyclidine in microliter samples of rat serum
Authors: Hendrickson Howard P. , Whaley E. Cathrine , Owens S. Michael
Published: December 2004

A liquid chromatographic/tandem mass spectrometric method is described for the determination of phencyclidine (PCP) in small volumes of rat serum (e.g. 50 µl). Samples were extracted using a mixed‐mode strong cation‐exchange column and then separated isocratically using a narrow‐bore (2.1 mm i.d.) 3 µm Hypersil phenyl column and a mobile phase consisting of an ammonium formate buffer (pH 2.7) with 60% (v/v) methanol. Detection was accomplished using positive ion electrospray ionization in the multiple reaction monitoring mode. Mass spectra were obtained and peaks were observed at an m/z (% abundance) of 244 (100), 159 (25), and 86 (89). Tandem mass spectra were also obtained from the m/z 244 precursor ion with peaks observed at m/z 159 (100), 86 (96), and 91 (11). Optimum serum PCP sensitivity and precision were obtained at a transition of m/z 244 → 159. Matrix‐associated ion suppression did not significantly affect the accuracy (100–112%) or precision (CV ≤8%) of the assay. The lower limit of quantitation was 1 ng ml−1 in 50 µl of serum. The method was used to study the serum pharmacokinetics of PCP in rats after an intravenous bolus dose of PCP. Copyright © 2004 John Wiley & Sons, Ltd.
Novel Biodegradable Polymers as Gene Carriers
Authors: Yang Yuan , Jia Wenxiang , Qi Xin , Yang Chun , Liu Li , Zhang Zairong , Ma Juhui , Zhou Shaobing , Li Xiaohong
Published: December 2004

Summary: This study investigated two new biodegradable polymers as gene controlled‐released coatings for gene transfer. Poly(ethylene glycol)‐co‐poly(D,L‐lactic acid) (PELA) and poly(ethylene glycol)‐co‐poly(lactic acid)‐co‐poly(glycolic acid) random copolymer (PELGA) were synthesized and used as microspheres matrices with encapsulated plasmid pCH110. The plasmid loading efficiency, cytotoxicity, transfection efficiency and in vitro degradation and release profiles of microsphere complexes were evaluated in details. The biodegradable polymers showed high DNA loading efficiency and low cytotoxicity as gene controlled‐released coatings, and the poly(ethylene glycol) (PEG) contents of polymer matrices influenced the diameter, loading efficiency and transfection efficiency of plasmid DNA within the microspheres. The average diameters of PELA and PELGA microspheres were between 0.5 and 1.5 μm, and the plasmid loading efficiency was 62 and 73% for PELA and PELGA microspheres with 10% PEG content, respectively. In vitro testing showed a gradual release profile of DNA from polymeric matrices. The polymers/DNA microspheres had high transfection efficiency and early gene expression and maintenance of gene expression level for up to 96 h, although transfection efficiency were slightly lower than that of liposome in the initial 24 h. The biodegradable polymeric materials possess potential superiority as gene carriers.

Percent release of DNA from PELA and PELGA microspheres with 10% PEG content in vitro.

magnified image

Percent release of DNA from PELA and PELGA microspheres with 10% PEG content in vitro.
Immunological mechanisms elicited at the tumour site by lymphocyte activation gene‐3 (LAG‐3) versus IL‐12: sharing a common Th1 anti‐tumour immune pathway
Authors: Carlo Emma Di , Cappello Paola , Sorrentino Carlo , D'Antuono Tommaso , Pellicciotta Antonella , Giovarelli Mirella , Forni Guido , Musiani Piero , Triebel Fréderic
Published: December 2004

The experimentally induced TS/A murine mammary carcinoma is poorly immunogenic and mainly infiltrated by antigen‐presenting cells (APCs), namely macrophages and immature dendritic cells (DCs). Human (h) and mouse (m) lymphocyte activation gene‐3 (LAG‐3 or CD233) is a physiological MHC class II ligand and powerful APC activator. A gene transfer approach has revealed its anti‐tumour activity in this model: hLAG‐3 was more effective than mLAG‐3. To obtain a clearer picture of the immunoregulatory mechanisms associated with the rejection dynamics of h‐ and m‐LAG‐3 transfectants, immunohistochemistry and confocal microscopy analyses of TS/A‐hLAG‐3, TS/A‐mLAG‐3, and control TS/A‐pc tumours were performed. The immune events elicited by mLAG‐3 and m‐interleukin (IL)‐12 were also compared, since their rejection kinetics were quite similar, and LAG‐3 enables IL‐12 production by macrophages and DCs. Both the TS/A‐h‐ and, to a lesser extent, the m‐LAG‐3 rejection areas were characterized by an impressive recruitment of APCs, granulocytes, NK cells, CD4+ T lymphocytes and CD8+ IFNγ‐expressing cells. In both cases, infiltration by APCs was accompanied by strong CD80 and CD86 expression and macrophage nitric oxide (NO) synthase up‐regulation. Distinct expression of IL‐12 and CXCL9 was also found, especially in the draining lymph nodes. T lymphocytes and CD86‐expressing APCs were significantly prevalent in both the TS/A‐h‐ and the m‐LAG‐3 compared with the TS/A‐mIL‐12 rejection area. Production of IFNγ, TNFα and IL1β, and chemokines, namely CXCL5, CXCL9, CXCL10, CXCL11, CCL5, and CCL2, by infiltrating leukocytes and signs of defective neovascularization were detected in tumours expressing h‐LAG‐3‐, m‐LAG‐3‐, and m‐IL‐12. However, IFNγ, CCL2, and CCL5 production prevailed in the TS/A‐hLAG‐3 rejection area. Taken together, these results indicate that LAG‐3 expression by engineered tumour cells efficiently promotes intra‐tumoural recruitment, activation, and Th1 commitment of APCs, and leads to a wide intra‐tumoural influx of non‐specific and specific reactive cells, and the release of immunoregulatory and cytotoxic mediators. Many of LAG‐3's anti‐tumour activities are shared with IL‐12. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Primary extramedullary plasmacytoma and multiple myeloma: phenotypic differences revealed by immunohistochemical analysis
Authors: Kremer Marcus , Ott German , Nathrath Michaela , Specht Katja , Stecker Katrin , Alexiou Christoph , Quintanilla‐Martinez Leticia , Fend Falko
Published: December 2004

Primary extramedullary plasmacytomas are infrequent, typically solitary, plasma cell neoplasms that generally pursue an indolent clinical course but may, rarely, convert to multiple myeloma. Phenotypic differences between these two entities are not well defined. Twenty‐eight cases of primary extramedullary plasmacytoma and 26 cases of both medullary (n = 17) and extramedullary (n = 9) multiple myeloma were analysed for the expression of proteins known to play a role in the biology of multiple myeloma. Immunohistochemistry was performed on paraffin wax sections using antibodies against cyclin D1, Bcl‐2, Bcl‐xL, p27, p21, p53, MIB1, CD20, and CD56. Twenty‐three extramedullary plasmacytomas were localized in the upper aerodigestive tract, four in the lymph nodes, and one in the testis. There was a strong male predominance (M : F = 6 : 1). None of the patients died from the disease or progressed to multiple myeloma (mean follow‐up 50 months). Nine patients developed local relapse and one patient's tumour evolved into a B‐cell non‐Hodgkin's lymphoma. In contrast to both intra‐ and extra‐medullary multiple myeloma, extramedullary plasmacytoma showed absence of cyclin D1 (p < 0.001) and infrequent expression of CD56 (p < 0.001). Furthermore, extramedullary plasmacytomas were characterized by weaker staining for Bcl‐2 protein and rare overexpression of p21 and p53. In comparison to extramedullary multiple myeloma, extramedullary plasmacytoma showed a more mature morphology and lower proliferation indices (p = 0.008). There was no association between the phenotypic parameters investigated and clinical outcome in extramedullary plasmacytoma. In summary, extramedullary plasmacytoma and multiple myeloma show significant immunophenotypic differences, some of which may be of both diagnostic utility and biological relevance. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Characteristics of the biodegradability and physical properties of stereocomplexes between poly(L‐lactide) and poly(D‐lactide) copolymers
Authors: Shirahama Hiroyuki , Ichimaru Akiko , Tsutsumi Chikara , Nakayama Yuushou , Yasuda Hajime
Published: December 2004

Random and block copolymerizations of L‐ or D‐lactide with ε‐caprolactone (CL) were performed with a novel anionic initiator, (C5Me5)2SmMe(THF), and they resulted in partial epimerization, generating D,L‐ or meso‐lactide polymers with enhanced biodegradability. A blend of PLLA‐r‐PCL [82/18; PLLA = poly(L‐LA) and PCL = poly(ε‐caprolactone)] and PDLA‐r‐PCL [79/21; PDLA = poly(D‐LA)] prepared by the solution‐casting method generated a stereocomplex, the melting temperature of which was about 40 °C higher than that of the nonblended copolymers. A blend of PLLA‐b‐PCL (85/15) and PDLA‐b‐PCL (82/18) showed a lower elongation at break and a remarkably higher tensile modulus than stereocomplexes of PLLA‐r‐PCL/PDLA‐r‐PCL and PLLA/PDLA. The biodegradability of a blend of PLLA‐r‐PCL (65/35) and PDLA‐r‐PCL (66/34) with proteinase K was higher than that of PLLA‐b‐PCL (47/53) and PDLA‐b‐PCL (45/55), the degradability of which was higher than that of a PLLA/PDLA blend. A blend film of PLLA‐r‐PDLLA (69/31)/PDLA‐r‐PDLLA (68/32) exhibited higher degradability than a film of PLLA/PDLLA [PDLLA = poly(D,L‐LA)]. A stereocomplex of PLLA‐r‐PCL‐r‐PDMO [80/18/2; PDMO = poly(L‐3,D,L‐6‐dimethyl‐2,5‐morpholinedion)] with PDLA‐r‐PCL‐r‐PDMO (81/17/2) showed higher degradability than PLLA‐r‐PDMO (98/2)/PDLA‐r‐PDMO (98/2) and PLLA‐r‐PCL (82/18)/PDLA‐r‐PCL (79/21) blends. The tensile modulus of a blend of PLLA‐r‐PCL‐r‐PDMO and PDLA‐r‐PCL‐r‐PDMO was much higher than that of a blend of PLLA‐r‐PDMO and PDLA‐r‐PDMO. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 438–454, 2005
Individualized growth assessment of fetal soft tissue using fractional thigh volume
Authors: Lee W. , Deter R. L. , McNie B. , Gonçalves L. F. , Espinoza J. , Chaiworapongsa T. , Romero R.
Published: December 2004

Objectives

The main goals of this study were to introduce fractional thigh volume (TVol) as a new soft tissue parameter for fetal growth evaluation, define its relationship to menstrual age, and develop individualized fetal growth standards based on Rossavik growth models.

Methods

A prospective, longitudinal study of 22 fetuses was conducted with conventional biometry and TVol measurements by three‐dimensional ultrasonography. Infant growth outcomes were determined from modified neonatal growth assessment scores. Rossavik functions (P = c(t)k+s(t)) were used to fit complete datasets to examine relationships between TVol and model coefficients. Second‐trimester models were subsequently specified from the linear slopes of growth curves before 28.0 menstrual weeks with each fetus acting as its own control. Third‐trimester trajectories and birth measurements were predicted for standard growth parameters and TVol. Observed and predicted measurements were compared using percent deviations and growth potential realization index values. Four additional infants, with serial prenatal scans and postnatal evidence of intrauterine growth restriction (IUGR), were also evaluated.

Results

All 22 fetuses had no evidence of growth abnormalities after delivery. Accelerated soft tissue deposition occurred in the fetal thigh by 28 menstrual weeks. A mean TVol start point of 9.0 ± 1.4 menstrual weeks was consistent with embryological studies of thigh development. Rossavik functions fitted all TVol trajectories well (mean R2 = 0.998 ± 0.002). By fixing the coefficient k at its mean value (2.976), the fit did not change and the variabilities of coefficients c and s were reduced. The mean percent deviation between observed and predicted third‐trimester TVol measurements was −0.048 ± 7.5%. Relatively early pathological deviations were observed for TVol in all four fetuses with IUGR; in these cases the abdominal circumference was abnormal in only one fetus and thigh circumference in none.

Conclusions

Individualized growth assessment can be used to accurately predict TVol during the third trimester of pregnancy and at birth. Expected growth trajectories, from second‐trimester data, do not rely on population‐based standards because each fetus serves as its own control. This new parameter may allow earlier detection and improved monitoring of fetal soft tissue abnormalities such as IUGR. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Ozone production in transpacific Asian pollution plumes and implications for ozone air quality in California
Authors: Hudman R. C. , Jacob D. J. , Cooper O. R. , Evans M. J. , Heald C. L. , Park R. J. , Fehsenfeld F. , Flocke F. , Holloway J. , Hübler G. , Kita K. , Koike M. , Kondo Y. , Neuman A. , Nowak J. , Oltmans S. , Parrish D. , Roberts J. M. , Ryerson T.
Published: December 2004

We examine the ozone production efficiency in transpacific Asian pollution plumes, and the implications for ozone air quality in California, by using aircraft and surface observations in April–May 2002 from the Intercontinental Transport and Chemical Transformation 2002 (ITCT 2K2) campaign off the California coast and the Pacific Exploration of Asian Continental Emission–B (PEACE‐B) campaign over the northwest Pacific. The observations are interpreted with a global three‐dimensional chemical transport model (GEOS‐CHEM). The model reproduces the mean features observed for CO, reactive nitrogen oxides (NOy), and ozone but underestimates the strong (∼20 ppbv) stratospheric contribution to ozone in the middle troposphere. The ITCT 2K2 aircraft sampled two major transpacific Asian pollution plumes, one on 5 May at 5–8 km altitude with CO up to 275 ppbv but no elevated ozone and one on 17 May at 2.5–4 km altitude with CO up to 225 ppbv and ozone up to 90 ppbv. We show that the elevated ozone in the latter plume is consistent with production from peroxyacetylnitrate (PAN) decomposition during subsidence of the plume over the northeast Pacific. This production is particularly efficient because of the strong radiation and low humidity of the subsiding environment. We argue that such PAN decomposition represents a major and possibly dominant component of the ozone enhancement in transpacific Asian pollution plumes. Strong dilution of Asian pollution plumes takes place during entrainment in the U.S. boundary layer, greatly reducing their impact at U.S. surface sites. California mountain sites are more sensitive to Asian pollution because of their exposure to the free troposphere. Model results indicate a mean Asian pollution enhancement of 7 ppbv ozone at Sequoia National Park in May 2002 on those days when the 8‐hour average ozone concentration exceeded 80 ppbv.
Fibroblast growth factor-223 binds directly to the survival of motoneuron protein and is associated with small nuclear RNAs
Authors: CLAUS Peter , BRUNS Alexander-Francisco , GROTHE Claudia
Published: December 2004

The SMN (survival of motoneuron) protein is mutated in patients with the neurodegenerative disease spinal muscular atrophy. We have shown previously that a high-molecular-mass isoform of FGF (fibroblast growth factor) 2 (FGF-223) is in a complex with SMN [Claus, Döring, Gringel, Müller-Ostermeyer, Fuhlrott, Kraft and Grothe (2003) J. Biol. Chem. 278, 479–485]. FGF-2 is a neurotrophic factor for motoneurons, and is known not only as a classical extracellular growth factor, but also as a nuclear protein. In the present study, we demonstrate that SMN binds to the arginine-rich N-terminus of FGF-223. In turn, FGF-223 interacts with amino acid residues 1–90 of the human SMN protein. This sequence displays nucleic-acid-binding capacity and overlaps partially with known binding sites for Gemin2/SIP1 (SMN-interacting protein 1) and p53. Finally, as a functional consequence of FGF-223 binding to SMN, FGF-223 is in a complex with the small nuclear RNAs U2 and U4. Since SMN functions as an assembly factor for snRNPs (small nuclear ribonucleoprotein particles), these results suggest binding of FGF-223 to snRNPs.