bluuebunny/crossref_metadata_2025 huggingface dataset:
Advances in imaging mouse tumour models in vivo
Authors: Lyons Scott K
Published: January 2005

Significant progress has been made recently in the variety of ways that cancer can be non‐invasively imaged in murine tumour models. The development and continued refinement of specialized hardware for an array of small animal imaging methodologies are only partly responsible. So too has been the development of new imaging techniques and materials that enable specific, highly sensitive and quantitative measurement of a wide range of tumour‐related parameters. Included amongst these new materials are imaging probes that selectively accumulate in tumours, or that become activated by tumour‐specific molecules in vivo. Other tumour imaging strategies have been developed that rely upon the detection of reporter transgene expression in vivo, and these too have made a significant impact on both the versatility and the specificity of tumour imaging in living mice. The biological implications resulting from these latest advances are presented here, with particular emphasis on those associated with MRI, PET, SPECT, BLI, and fluorescence‐based imaging modalities. Taken together, these advances in tumour imaging are set to have a profound impact on our basic understanding of in vivo tumour biology and will radically alter the application of mouse tumour models in the laboratory. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Cell and tissue responses to genotoxic stress
Authors: Coates Philip J , Lorimore Sally A , Wright Eric G
Published: January 2005

Cancers arise as a consequence of the accumulation of multiple genetic mutations in a susceptible cell, resulting in perturbation of regulatory networks that control proliferation, survival, and cellular function. Here, the sources of cellular stress that can cause oncogenic mutations and the responses of cells to DNA damage are reviewed. The role of different repair pathways and the potential for cell‐ and tissue‐specific reliance on individual repair mechanisms are discussed. Evidence for cell‐ and tissue‐specific activation of p53‐mediated growth arrest and apoptosis after exposure to an individual genotoxin is assessed and some of the potential mediators of these different responses are provided. These cell‐ and tissue‐specific responses to particular forms of DNA damage are likely to be key determinants of tissue‐specific tumour susceptibility, and there is good evidence for genetic variations in these responses. The role that genotoxic agents play in altering the microenvironment to produce indirect effects on tumourigenesis through altered production of free radicals and cytokines that are characteristic of inflammatory‐type processes is also evaluated. Changes to the microenvironment as direct or indirect effects of genotoxic stress can be involved in both tumour initiation and progression and may even be a prerequisite for tumourigenesis. Therefore, tumour susceptibility after endogenous or exogenous genotoxic stress represents a balance between cell‐intrinsic responses of target cells and changes to the microenvironment. A fuller understanding of cell‐ and tissue‐specific responses, alterations to the microenvironment, and genetic modifiers of these responses could lead to novel prevention and therapeutic strategies for common forms of human malignancy. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Hunting the primary: novel strategies for defining the origin of tumours
Authors: Dennis Jayne L , Oien Karin A
Published: January 2005

In 1995, two methods of genome‐wide expression profiling were first described: expression microarrays and serial analysis of gene expression (SAGE). In the subsequent 10 years, many hundreds of papers have been published describing the application of these technologies to a wide spectrum of biological and clinical questions. Common to all of this research is a basic process of data gathering and analysis. The techniques and statistical and bio‐informatic tools involved in this process are reviewed. The processes of class discovery (using clustering and self‐organizing maps), class prediction (weighted voting, k nearest neighbour, support vector machines, and artificial neural networks), target identification (fold change, discriminant analysis, and principal component analysis), and target validation (RT‐PCR and tissue microarrays) are described. Finally, the diagnostic problem of adenocarcinomas that present as metastases of unknown origin is reviewed, and it is demonstrated how integration of expression profiling techniques promises to throw new light on this important clinical challenge. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Gastrointestinal lymphoma: where morphology meets molecular biology
Authors: Isaacson Peter G , Du Ming‐Qing
Published: January 2005

Primary gastrointestinal lymphomas are best exemplified by mucosa‐associated lymphoid tissue (MALT) lymphoma of the stomach and enteropathy‐type T‐cell lymphoma (ETL). Both lymphomas were initially recognized on morphological grounds and their identification as distinct clinicopathological entities has subsequently been vindicated following integrated immunophenotypic, molecular, and cellular biological investigations. Delineation of the phenotypic, molecular, and biological properties of these lymphomas at various clinicopathological stages of their development has also provided critical information for the clinical management of patients with these diseases. Here, the histopathology and recent advances in phenotypic and molecular characterization of gastric MALT lymphoma and ETL and their applications in diagnosis and clinical management are reviewed. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
What have animal models taught us about the p53 pathway?
Authors: Lozano Guillermina , Zambetti Gerard P
Published: January 2005

Mouse models have provided important insight into the in vivo significance of upstream and downstream signals that regulate the p53 tumour suppressor. One important lesson learned from these models is that negative regulators of p53 are critical in vivo modulators of p53 activity. Additionally, upstream regulators of p53 activity, such as p19Arf and Atm, are themselves critical tumour modifiers/suppressors. The presence of multiple positive regulators of p53 and numerous downstream targets indicates a redundancy that ensures activation of the p53 pathway. Importantly, p53 plays a prominent role as a tumour suppressor in vivo by virtue of its ability both to block cell cycle progression and to induce cell death. Finally, different p53 mutants have different properties in vivo. Three missense mutations have been generated at the p53 locus and all three exhibit unique differences in their ability to contribute to the tumour phenotype. Clearly, determining the levels of p53 inhibitors, and the typing of p53 mutations in human tumours should be performed to determine the best avenue for treatment. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Dormant hypermethylated tumour suppressor genes: questions and answers
Authors: Esteller Manel
Published: January 2005

The epigenetic inactivation of tumour suppressor genes by promoter CpG island methylation is nowadays one of the hottest topics in cancer research. However, there are still several important open questions: Can we use CpG island hypermethylation to classify tumours according to their clinical behaviour and chemosensitivity? How do we prove that our hypermethylated gene is important for cancer development and/or progression? Which enzymes are directly responsible for the CpG island hypermethylation of tumour suppressor genes? How is the chromatin structure and molecular environment in and around the hypermethylated CpG islands? Can we wake up these dormant hypermethylated tumour suppressor genes in an epigenetic therapy of cancer? Some answers are provided in this review, but other questions remain unsolved, awaiting the eager epigenetic researcher. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Cell‐cycle‐dependent regulation of DNA replication and its relevance to cancer pathology
Authors: Tachibana Kiku‐e K , Gonzalez Michael A , Coleman Nicholas
Published: January 2005

The highly orchestrated process of DNA replication ensures the accurate inheritance of genetic information from one cell generation to the next. The exact execution of DNA replication depends on a large number of proteins that are being studied extensively in the cell cycle field. Some of these proteins, such as the minichromosome maintenance proteins (MCMs), are essential for the process of DNA replication itself. Others such as geminin are specifically required to limit DNA replication to once per cell cycle. Together, these proteins protect the stability of the human genome in cycling cells. Their expression has been compared with routinely used proliferation markers, such as Ki‐67 (MIB‐1) and proliferating cell nuclear antigen (PCNA), which fulfil the requirements of molecular tumour markers to varying extents. However, it is with regard to the depth of our understanding of antigen biology that the MCM proteins and geminin qualify exceptionally well as novel cell‐cycle biomarkers for routine use in clinical practice, particularly in cancer detection and estimation of prognosis. Expression microarray analysis has also independently identified MCMs and their interacting proteins as determinants of the inherent aggressiveness of a wide range of epithelial malignancies. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The pathophysiology of HOX genes and their role in cancer
Authors: Grier DG , Thompson A , Kwasniewska A , McGonigle GJ , Halliday HL , Lappin TR
Published: January 2005

The HOM‐C clustered prototype homeobox genes of Drosophila, and their counterparts, the HOX genes in humans, are highly conserved at the genomic level. These master regulators of development continue to be expressed throughout adulthood in various tissues and organs. The physiological and patho‐physiological functions of this network of genes are being avidly pursued within the scientific community, but defined roles for them remain elusive. The order of expression of HOX genes within a cluster is co‐ordinated during development, so that the 3′ genes are expressed more anteriorly and earlier than the 5′ genes. Mutations in HOXA13 and HOXD13 are associated with disorders of limb formation such as hand–foot–genital syndrome (HFGS), synpolydactyly (SPD), and brachydactyly. Haematopoietic progenitors express HOX genes in a pattern characteristic of the lineage and stage of differentiation of the cells. In leukaemia, dysregulated HOX gene expression can occur due to chromosomal translocations involving upstream regulators such as the MLL gene, or the fusion of a HOX gene to another gene such as the nucleoporin, NUP98. Recent investigations of HOX gene expression in leukaemia are providing important insights into disease classification and prediction of clinical outcome. Whereas the oncogenic potential of certain HOX genes in leukaemia has already been defined, their role in other neoplasms is currently being studied. Progress has been hampered by the experimental approach used in many studies in which the expression of small subsets of HOX genes was analysed, and complicated by the functional redundancy implicit in the HOX gene system. Attempts to elucidate the function of HOX genes in malignant transformation will be enhanced by a better understanding of their upstream regulators and downstream target genes. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Mechanical properties of polymer‐ceramic nanocomposite coatings by depth‐sensing indentation
Authors: Sun Jiakuan , Francis Lorraine F. , Gerberich William W.
Published: January 2005

The mechanical properties of antimony‐doped tin oxide (ATO) nanoparticle/poly (vinyl acetate‐co‐acrylic) (PVAc‐co‐acrylic) coatings with various ATO contents were investigated using depth‐sensing indentation. These coatings were prepared from aqueous dispersions of ATO and PVAc‐co‐acrylic latex. Three types of methods, including a prolonged load holding time, analysis of the pull‐off portion of the unloading curve, and dynamic indentation, were used to characterize the mechanical properties of these composite coatings. As compared to dynamic indentation, quasistatic conventional indentation even with a prolonged load holding time and analysis of the pull‐off portion of unloading curves generate more scattered coating modulus data. This is due to the effect of creep deformation and inconsistency of the pull‐off portion dimension, respectively. The results obtained using dynamic indentation are more reliable because the technique minimizes the effect of creep deformation using a combination load including static and dynamic components. The dynamic indentation results indicate that the addition of the ATO nanoparticles made the composite coatings stiffer and more elastic solid–like. For example, the storage indentation modulus of the PVAc‐co‐acrylic coating is ∼1 GPa and tan δ is ∼1.6; the addition of 0.50 volume fraction of ATO increased the modulus to ∼5 GPa and reduced the tan δ to ∼0.01. POLYM. ENG. Sci. 45:207–216, 2005. © 2005 Society of Plastics Engineers.
Nuclear magnetic resonance monitoring of chain‐end functionality in the atom transfer radical polymerization of styrene
Authors: Lutz Jean‐François , Matyjaszewski Krzysztof
Published: January 2005

The evolution of the bromine end functionality during the bulk atom transfer radical polymerization (ATRP) of styrene [in the presence of the catalyst CuBr/4,4′‐di‐(5‐nonyl)‐2,2′‐bipyridine] was monitored with 600‐MHz 1H NMR. A decrease in the functionality versus the conversion was observed. The loss of functionality was especially significant at very high conversions (>90%). The experimental data were compared with a kinetic model of styrene ATRP. The latter indicated that the loss of chain‐end functionality was partly due to bimolecular terminations but was mainly due to β‐H elimination reactions induced by the copper(II) deactivator. These elimination reactions, which occurred later in the reaction, did not significantly affect the polymer molecular weights and the polydispersity. Therefore, a linear evolution of the molecular weights and low‐polydispersity polymers were still observed, despite a loss of functionality. Understanding these side reactions helped in the selection of the proper conditions for reducing the contribution of the elimination process and for preparing well‐defined polystyrene (number‐average molecular weight ∼10,000 g mol−1; weight‐average molecular weight/number‐average molecular weight ∼1.1) with a high functionality (92%). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 897–910, 2005
Synthesis, characterization, and degradation of silicon(IV) phthalocyanines conjugated axially with poly(sebacic anhydride)
Authors: Lee Priscilla P. S. , Ngai To , Yang Cheng , Wu Chi , Ng Dennis K. P.
Published: January 2005

A novel silicon(IV) phthalocyanine with two axial poly(sebacic anhydride) chains has been synthesized by melt condensation of silicon phthalocyanine dihydroxide and oligo(sebacic anhydride). The polymer has been spectroscopically characterized and its molecular weights have been determined by gel permeation chromatography (GPC) and 1H NMR spectroscopy. Nanoparticles with an intensity‐average apparent hydrodynamic radius of 65 ± 1 nm have been prepared from this polymer via a microphase inversion method with sodium dodecyl sulfate as the surfactant. The spherical nanoparticles contain loosely aggregated polymer chains, trapping about 90% of the water. On treatment with NaOH, these nanoparticles undergo degradation that has been monitored by laser light scattering and fluorescence spectroscopy. Because of the axial substitution, the change in the aggregation state of the phthalocyanine core of this polymer during nanoparticle formation and degradation is relatively small compared with that of the zinc(II) phthalocyanine analogue reported earlier, in which poly(sebacic anhydride) chains are linked to the periphery of the phthalocyanine ring. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 837–843, 2005
New polyphenylene‐g‐polystyrene and polyphenylene‐g‐polystyrene/poly(ε‐caprolactone) copolymers by combined controlled polymerization and cross‐coupling processes
Authors: Yurteri Seda , Cianga Ioan , Demirel A. Levent , Yagci Yusuf
Published: January 2005

1,4‐Dibromo‐2‐(bromomethyl)benzene and 1,3‐dibromo‐5‐(bromomethyl)benzene were used as initiators in the atom transfer radical polymerization of styrene in conjunction with CuBr/2,2′‐bipyridine as a catalyst. The resulting polystyrene (PSt)‐based macromonomers, possessing at one end a 2,5‐dibromophenylene or 3,5‐dibromophenylene moiety, were used in combination with 2,5‐dihexylbenzene‐1,4‐diboronic acid for Suzuki coupling in the presence of Pd(PPh3)4 as a catalyst or with the system NiCl2/2,2′‐bipyridine/triphenylphosphine/Zn for Yamamoto polymerization. Polyphenylenes (PPs) with PSt chains as substitution groups were obtained. The same macromonomers were used in Yamamoto copolycondensation reactions, in combination with a poly(ε‐caprolactone) (PCL) macromonomer, and this resulted in PPs with PSt/PCL side chains. The obtained PPs had good solubility properties in common organic solvents at room temperature similar to those of the starting macromonomers. The new polymers were characterized with 1H (13C) NMR, IR, and gel permeation chromatography. The optical properties of the polymers were monitored with UV and fluorescence spectroscopy. The thermal behaviors of the macromonomers and final PPs were investigated with differential scanning calorimetry and compared. The morphology of PPs containing PSt and PCL blocks was characterized with atomic force microscopy, and a microphase‐separated layered morphology was observed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 879–896, 2005
Controlled anionic synthesis of star‐shaped polystyrene by the incremental addition of divinylbenzene
Authors: Lee Hyung‐Jae , Lee Kwanyoung , Choi Namsun
Published: January 2005

Star polystyrenes were synthesized from polystyryllithium with an incremental procedure in which equally divided portions of divinylbenzene (DVB) were added periodically. When the addition of DVB was repeated, the content of the unreacted polystyryllithium dramatically decreased, and complete conversion was readily achieved. In the conventional linking reaction, however, in which all the required amounts of DVB were added at once, there was an incomplete conversion of the arm polymer. The arm number of star polymers also continuously increased upon the subsequent addition of DVB. The incremental‐addition method effectively synthesized star polystyrene, minimizing uncoupled polystyrene and reproducibly controlling the arm number of star polystyrene without the formation of gel polymers. The intrinsic viscosity of star polystyrene was measured to determine the highly branched structure of star polystyrene prepared by incremental or one‐shot addition. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 870–878, 2005
Copolymerization of carbon dioxide and epoxide
Authors: Sugimoto Hiroshi , Inoue Shohei
Published: January 2005

The original article to which this Erratum refers was published in J Polym Sci Part A: Polym Chem (2004) 42(22) 5561‐5573.

No abstract.
DFT LCAO and plane wave calculations of SrZrO3
Authors: Evarestov R. A. , Bandura A. V. , Alexandrov V. E. , Kotomin E. A.
Published: January 2005

The results of the density functional (DFT) LCAO and plane wave (PW) calculations of the electronic and structural properties of four known SrZrO3 phases (Pm3m, I4/mcm, Cmcm and Pbnm) are presented and discussed. The calculated unit cell energies and relative stability of these phases agree well with the experimental sequence of SrZrO3 phases as the temperature increases.

The lattice structure parameters optimized in the PW calculations for all four phases are in good agreement with the experimental neutron diffraction data. The LCAO and PW results for the electronic structure, density of states and chemical bonding in the cubic phase (Pm3m) are discussed in detail and compared with the results of previous PW calculations. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Site inequivalence for Mn2+substitution on Zn sites in ZnGeP2and ZnSiP2
Authors: Gehlhoff W. , Azamat D. , Voevodin V. G. , Hoffmann A.
Published: January 2005

The magnetic site‐inequivalence of the both Zn sites in ZnGeP2(ZnSiP2) could be resolved for MnZn2+(S=$ \textstyle 5 \over 2 $) by electron paramagnetic resonance (EPR) measurements. The EPR spectra are analyzed with the generalized spin Hamiltonian (SH) for S4symmetry. We found that the Mn substitu‐tion on Zn site causes a strong local distortion of the free parameterxf, which describes the positions of the anions in chalcopyrite structures withc/a≠ 2. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low‐energy (0.1 eV) electron attachment SS bond cleavage assisted by Coulomb stabilization
Authors: Sawicka Agnieszka , Berdys‐Kochańska Joanna , Skurski Piotr , Simons Jack
Published: January 2005

Electron capture by the ion H3C–S–S–CH2–CH2–NH at either the −NH site (to form the Rydberg radical H3C–S–S–CH2–CH2–NH3) or into the S–S antibonding σ* orbital is shown to be able to produce the same S–S bond fragmentation products H3C–S and HS–CH2–CH2–NH2, albeit by very different pathways. Capture into the S–S σ* orbital is, in the absence of the nearby positive site, endothermic by approximately 0.9 eV and leads to an electronically metastable anion that can undergo dissociation or autodetachment. In contrast, in the presence of the stabilizing Coulomb potential provided by the nearby NH site, electron attachment into the S–S σ* orbital is rendered exothermic. As a result, as we have shown in this paper, the effective cross sections for forming the H3C–S and HS–CH2–CH2–NH2 products via attachment at the −NH and S–S σ* sites are predicted to be comparable for our model compound. Moreover, we predict that the σ* site will become more amenable to electron attachment compared with the −NH site for compounds in which the distance between the S–S bond and the protonated amine is larger than in our cation. These findings and insights should be of substantial value to workers studying bond cleavage rates and fragmentation patterns in gaseous positively charged samples of peptides and proteins. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Quantum chemistry study of monomer electronic properties in water clusters and liquid water and methanol
Authors: Tu Yaoquan , Laaksonen Aatto
Published: January 2005

A self‐consistent quantum chemistry approach is presented to study the electronic properties of a single molecule in condensed phases where Coulomb interaction is predominant in the intermolecular interactions. Using the approach, implemented in this work in a self‐consistent charge way, the electronic properties of a single water molecule in water clusters, liquid water, and those of a single methanol molecule in liquid methanol are studied at the second‐order Møller–Plesset level. The average monomer dipole moments for water and methanol in their liquid phases are calculated to be 2.65 D and 2.39 D, respectively. The changes in quadrupole moments are also discussed. For water monomer, the polarizability changes upon going from gas state to interaction systems are reported, as well. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Memory formulas for perturbations in time‐dependent density functional theory
Authors: Maitra Neepa T.
Published: January 2005

Exact time‐dependent density functionals depend on both the entire history of the density and the initial wave function. Recently we have shown that the two effects are entangled by an exact condition that should be useful as a test in building accurate memory‐dependent functionals. Here we consider this condition for small perturbations and derive an exact relation connecting the exchange‐correlation kernel with initial‐state derivatives. We discuss other exact conditions on the initial‐state derivatives which shed some light on the elusive memory‐dependence in time‐dependent density functional theory. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Transmetatarsal Amputation: Three‐year Experience At Groote Schuur Hospital
Authors: Mwipatayi B.P. , Naidoo N.G. , Jeffery P.C. , Maraspini C.D. , Adams M.Z. , Cloete N.
Published: January 2005

Transmetatarsal amputation (TMA) for peripheral vascular disease has the reputation of being an operation with a poor outcome. This retrospective study reviewed a 3‐year consecutive series of TMA in diabetic and nondiabetic patients. All amputations performed for peripheral vascular disease at Groote Schuur Hospital from January 1999 to December 2002 were reviewed. Data were obtained from hospital records and operating theatre books. The following groups were defined for the purpose of this retrospective study: group 1, TMAs performed in diabetic patients; group 2, TMAs done in nondiabetic patients. Altogether, 43 TMAs were performed: 27 in group 1 and 16 in group 2. Perioperative mortality rates were 7% and 4%, respectively. Overall, the healing rate was 67%: 62% (17/27) in group 1 and 75% (12/16) in group 2. The median times to healing were 8 months in group 1 and 7 months in group 2. Toe pressure and the presence of advanced tibioperoneal disease influenced the outcome of TMA in diabetic patients.

Transmetatarsal amputation with a healed stump provided our patients with good mobility. Prediction of healing after operation is unreliable. There was no statistical difference in outcome in diabetic (group 1) versus nondiabetic (group 2) patients.
Valproic acid induces apoptosis dependent of Yca1p at concentrations that mildly affect the proliferation of yeast
Authors: Mitsui Kazuhiro , Nakagawa Daichi , Nakamura Masahiro , Okamoto Taro , Tsurugi Kunio
Published: January 2005

Valproic acid (VPA) inhibited the growth of yeast in a dose‐dependent manner with complete inhibition attained at 100 mM. When cells were exposed to 25 mM VPA, the wild‐type died showing apoptotic markers, while yca1Δ deleted of YCA1 encoding yeast caspase 1 survived. On the other hand, when cells were exposed to 50 mM VPA, both the wild‐type and yca1Δ died showing morphological features similar to those of the autophagic death of cdc28 which was also independent of YCA1. Thus, these results suggested that yeast cells die via YCA1‐dependent apoptosis when their proliferative activity is mildly impaired.
The evidence for emergency obstetric care
Authors: Paxton A. , Maine D. , Freedman L. , Fry D. , Lobis S.
Published: January 2005

Purpose

We searched for evidence for the effectiveness of emergency obstetric care (EmOC) interventions in reducing maternal mortality primarily in developing countries.

Methods

We reviewed population‐based studies with maternal mortality as the outcome variable and ranked them according to the system for ranking the quality of evidence and strength of recommendations developed by the US Preventive Services Task Force. A systematic search of published literature was conducted for this review, including searches of Medline, PubMed, Cochrane Database of Systematic Reviews, the Cochrane Pregnancy and Childbirth Database and the Cochrane Controlled Trials Register.

Results

The strength of the evidence is high in several studies with a design that places them in the second and third tier in the quality of evidence ranking system. No studies were found that are experimental in design that would give them a top ranking, due to the measurement challenges associated with maternal mortality, although many of the specific individual clinical interventions that comprise EmOC have been evaluated through experimental design. There is strong evidence based on studies, using quasi‐experimental, observational and ecological designs, to support the contention that EmOC must be a critical component of any program to reduce maternal mortality.
Dung beetle (Coleoptera: Scarabaeidae) diversity and community structure across three disturbance regimes in eastern Amazonia
Authors: Scheffler Pamela Y.
Published: January 2005

Anthropogenic disturbance in Amazonian forests has increased dramatically since the early 1980s and forest disturbance is expected to continue in the early twenty-first century. Logging and conversion to pasture for cattle are two of the largest causes of forest disturbance and destruction. This study examined the distribution and diversity of dung beetles (Coleoptera: Scarabaeidae) in intact forest and under three disturbance regimes (selective logging, clear-cutting and pasture) in a forest tract in southern Pará state, Brazil. Dung beetles were collected using faeces-baited pitfall traps, then identified, measured and weighed. Principal Components Analyses and the Sørensen's Index indicated that the intact and selectively logged areas were similar in terms of species composition but that the pasture areas and clear-cut areas had substantially different groups of species. Beetle size and diversity (as measured by species richness, Shannon index and Simpson's index) were lower in clear-cuts and pasture than in intact forest. The selectively logged forest was no less diverse than intact forest, and beetles were the same size or larger than those in intact forest. Total beetle biomass, however, was highest in the pasture due to the abundance of small-bodied beetles in this habitat. While the fact that selective logging has a relatively minor impact on the dung beetle community is heartening, the projected increase in the amount of highly disturbed landscape in Amazonia is expected to have a severe impact on dung beetle biodiversity in the region.
The role of clumped defecation in the spatial distribution of soil nutrients and the availability of nutrients for plant uptake
Authors: Feeley Kenneth
Published: January 2005

Many types of primate, particularly species of the genus Alouatta (howler monkey) defecate as a social group and tend to defecate repeatedly in specific locations (sometimes referred to as latrines; Andresen 2001, 2002; Gilbert 1997). The importance of these clumped defecations in the dispersal of seeds has been well investigated (Andresen 2001, 2002; Estrada & Coates-Estrada 1984, 1991; Julliot 1996). In contrast, no study has yet looked at the role of clumped defecation in the spatial distribution of soil nutrients and the availability of nutrients for plant uptake.
Determinants of tree species preference of birds in oak–acacia woodlands of Central America
Authors: Greenberg Russell , Bichier Peter
Published: January 2005

In mid-elevation areas of Mesoamerica, Acacia pennatula commonly occurs in mixed woods with various species of oak. During a 1-y study in Nicaragua, we found the abundance of birds in acacia was far higher than the representation of this species in the mix of trees, whether this is estimated by number of individual trees, canopy cover or foliage cover. This higher abundance was probably related to the fact that acacias supported approximately three to four times the abundance of arthropods that were found in oaks and twice the biomass. Although oak foliage supported fewer arthropods, relatively more of them were large (>1 cm). The greater preponderance of small arthropods in acacias versus oaks was probably related to the small leaflet size of acacias. However, it is likely that the higher abundance of arthropods in acacias, particularly herbivorous species, was related to the higher nutritional content of the acacia foliage (crude protein, minerals, non-structural carbohydrates) and lower content of digestion-inhibiting compounds (structural carbohydrates, total phenolics, condensed tannins). The major defensive mechanisms of acacia are mechanical (thorns) or qualitative-defence chemicals (cyanogenic glucosides) that are apparently more effective against vertebrate than invertebrate herbivores. These observations support the hypothesis that the anti-herbivore defences of acacia are primarily directed against large mammalian herbivores, rendering the foliage highly palatable to arthropods.
Is camera-trapping an efficient method for surveying mammals in Neotropical forests? A case study in south-eastern Brazil
Authors: Srbek-Araujo Ana Carolina , Chiarello Adriano Garcia
Published: January 2005

Although highly diverse (Fonseca et al. 1996), the Atlantic forest mammal fauna is still poorly known, with very few sites exhaustively inventoried or subjected to long-term studies (Passamani et al. 2000). Although the first surveys using camera traps were carried out in the 1920s (e.g. Chapman 1927), most studies are rather recent (Karanth & Nichols 1998). This is not different in Brazil, where few studies have been published (Marques & Ramos 2001, Santos-Filho & Silva 2002, Silveira et al. 2003, Trolle 2003, Trolle & Kéry 2003). Given this, the objective of this paper is to assess the efficiency of camera trapping as an inventory technique for Neotropical forests in general and Atlantic forest in particular. The study was conducted at the Santa Lúcia Biological Station (SLBS), a biologically rich Atlantic Forest preserve located in south-eastern Brazil (Mendes & Padovan 2000) where mammals have been intensively live-trapped, observed from line-transects or had indirect evidence of their presence (faeces, footprints, scratches, etc.) recorded in earlier years (Passamani et al. 2000).
Regeneration and population structure of Heliconia acuminata in Amazonian secondary forests with contrasting land-use histories
Authors: Bruna Emilio M. , Ribeiro Maria Beatriz Nogueira
Published: January 2005

An estimated 154 million ha of tropical forest are cleared each year by human activities such as cattle ranching and agriculture (Whitmore 1997). When the economic return of these sites declines, they are often abandoned and allowed to regenerate. As a result, ‘secondary’ or ‘regenerating’ forests are becoming an increasingly common feature in tropical landscapes (Guariguata & Ostertag 2001). Unlike treefall gaps and other ‘naturally’ disturbed areas, the regeneration of secondary forests on anthropogenically disturbed lands does not always follow a predictable pathway (reviewed in Guariguata & Ostertag 2001). Instead, the type and intensity of post-clearing land use has major implications for the trajectory along which succession proceeds (Guariguata & Ostertag 2001, Mesquita et al. 2001, Uhl et al. 1988).
Diversity of leaf phenology in a tropical deciduous forest in India
Authors: Kushwaha C. P. , Singh K. P.
Published: January 2005

Patterns of leaf phenological diversity were documented in nine key tree species of a tropical deciduous forest in the Vindhyan region of India. Monthly leaf counts on 160 tagged twigs on ten individuals of each species were made through two annual cycles. Tree species exhibited a gradient of deciduousness (∼leafless duration), ranging from semi-evergreen species (entire population never becoming leafless) to 7-mo-deciduous species. The semi-evergreen species initiated leaf flush (bud break of vegetative bud) earlier around the spring equinox. In all deciduous tree species synchronous leaf-flush initiation, with low inter-annual variability, occurred during the hot dry summer (May–June, day temperature >40 °C), prior to the onset of the rainy season. Based on the quantification of leafless period, leaf-flush duration, and leaf strategy index (leaf-flush rate/leaf-fall rate, proposed in this study) in different species, four plant functional types were recognized: (a) semi-evergreen, spring flushing, showing leaf exchange, with mean leafless period 8 d, leaf-flush duration 6–7 mo and leaf strategy index <0.5 (Shorea robusta); (b) <2-mo-deciduous, summer flushing, leafless period 3–8 wk, leaf-flush duration 5–6 mo, and leaf strategy index >0.5−<0.7 (Anogeissus latifolia, Diospyros melanoxylon and Hardwickia binata); (c) 2–4-mo-deciduous, summer flushing, leafless period 2–3 mo, leaf-flush duration 4–5 mo, and leaf strategy index >0.8−<1.0 (Acacia catechu, Lagerstroemia parviflora and Terminalia tomentosa); and (d) >4-mo-deciduous, summer flushing, leafless period >4–7 mo, leaf-flush duration 3–4 mo, and leaf strategy index 1.0 (Boswellia serrata and Lannea coromandelica). Conspecific trees showed asynchrony with respect to leaf-flush completion, initiation and completion of leaf-fall, and extent of leafless period. Leaf strategy index (indicating rate of resource use and conservation) was strongly related with the leafless period in different species (r=0.82) and can serve as a useful index in leaf phenological studies and classification of plant functional types.
Diel flight activity and ecological segregation within an assemblage of tropical forest dung and carrion beetles
Authors: Feer François , Pincebourde Sylvain
Published: January 2005

Temporal variation in activity of dung and carrion beetles in tropical forest is considered as a mechanism of ecological segregation between potentially competing species. We describe the diel flight activity of Scarabaeidae collected with baited pitfall traps at Les Nouragues field station in French Guiana. A total of 2663 individuals of 63 species was recorded, from the subfamilies Coprinae, Scarabaeinae and Aphodinae. Temporal guilds of diurnal, nocturnal and crepuscular species were identified. Diurnal species were about twice as numerous and abundant as either nocturnal or crepuscular species. Two main activity patterns characterize the diurnal species while nocturnal and crepuscular species show overlapping activity. The association of activity rhythm with the other niche variables, food selection, functional group, body size and relative abundance, was analysed using multiple correspondence analysis. Small diurnal coprophagous species were opposed to large crepuscular necrophagous species. Species packing is suggested but further analysis showed that the variables were independent of one another. The temporal differentiation of species combined with separation along multiple niche dimensions and resource gradients may facilitate the coexistence of species assumed to be strongly affected by interspecific competition.
Seasonal abundance in the floor-dwelling frog fauna on Iriomote Island of the Ryukyu Archipelago, Japan
Authors: Watanabe Shinichi , Nakanishi Nozomi , Izawa Masako
Published: January 2005

Abundance of floor-dwelling frogs was studied in the humid subtropical lowland forest of Iriomote Island, the Ryukyu Archipelago, southern Japan. Field survey was conducted monthly for 1 y, and the seasonal pattern of abundance was examined for each species. We observed 251 frogs belonging to four species of three families in a total sampling of 600 m2. Of these species, Microhyla ornata (66.5% of total frogs) and Fejervarya limnocharis (30.3%) were dominant in number. Total abundance of the frogs was strongly seasonal and peaked in the hottest month, August, while the number of frog species was one to three throughout the year. The seasonal pattern of abundance showed considerable variation among species, most likely due to their differences in reproductive season, and in physiological characteristics under the influence of varying temperature and rainfall. These patterns are more similar to those of temperate species than those of tropical species. The estimated density of all frogs ranged from 0.08 to 1.60 individuals m−1, and their average annual density and biomass were 4180 individuals ha−1 and 11460 g ha−1, respectively. These values, among the highest so far reported for floor-dwelling anurans, may be a feature of amphibian fauna in the humid subtropical forests on a small island.
Seasonality, dung specificity and competition in dung beetle assemblages in the Australian Wet Tropics, north-eastern Australia
Authors: Vernes Karl , Pope Lisa C. , Hill Christopher J. , Bärlocher Felix
Published: January 2005

A trapping study of five mammal species in wet sclerophyll forest adjacent to rain forest in the Australian Wet Tropics was used to examine the seasonal diversity, abundance and dung-specificity of dung beetles associated with mammal dung. A total of 542 dung beetles from 11 species within three genera was recovered from beneath the traps of 1104 mammal captures. The diversity of beetles associated with the dung of the northern bettong (Bettongia tropica), a mycophagous marsupial, differed significantly from the diversity predicted by a null model. Numbers of beetles varied significantly with type of dung, indicating preference by beetles. Beetle numbers were related positively to a 1-mo lag in monthly mean minimum temperature and less strongly to maximum temperature and rainfall. Significantly more beetles per mammal capture were detected in the wet season than in the dry season. Dung beetles showed a strong preference for either the Eucalyptus woodland (six species) or the adjacent Allocasuarina forest (four species), with only one species occurring in both habitat types. Beetle species from the Eucalyptus woodland were typically only detected in the late wet and early dry seasons, while species in the wetter Allocasuarina forest were generally collected during the late dry and early wet seasons. A significant ‘checkerboard’ species effect was detected in both time and space in both habitat types, suggesting that competition for dung was strong.
Threat reduction assessment of conventional and community-based conservation approaches to managing protected areas in Uganda
Authors: MUGISHA ARTHUR R. , JACOBSON SUSAN K.
Published: January 2005

Loss of wildlife, encroachment on wild lands and conflicts between protected areas and neighbouring communities continue to threaten the integrity of protected areas (PAs) in Uganda. To increase support from local communities and ensure long-term sustainability for Uganda's PAs, a policy of community-based conservation was introduced in 1988 as a management approach in seven PAs. The effectiveness of the community-based approach for reducing threats was compared to conventional PA management by conducting a threat reduction assessment at 16 PAs, seven with community-based approaches and nine without. Additional data collected using document reviews, interviews with government officials, and surveys of PA wardens were compared with the threat reduction assessments. Twenty-three primary threats were identified at PAs. Local game poaching was the most common threat. The threat reduction assessment indices of community-based PAs (mean=49.0±12) were not significantly different from those of conventional PAs (mean=37.96±21.6). Some specific threats, such as bush burning, logging, encroachment and unclear boundaries, seemed to be better mitigated at community-based PAs. Management approaches at all PAs mitigated fewer than half of the identified threats. Management approaches are needed that directly target PA threats, go beyond PA boundaries by involving additional government departments, link people's livelihoods to conservation efforts and strengthen PA institutions.
Three‐dimensional numerical simulation of fully coupled groundwater flow and land deformation in unsaturated true anisotropic aquifers due to groundwater pumping
Authors: Kim Jun‐Mo
Published: January 2005

A hydrogeomechanical numerical model is presented to evaluate three‐dimensional groundwater flow and land deformation in unsaturated true anisotropic aquifers due to groundwater pumping. This multidimensional numerical model is developed on the basis of the fully coupled poroelastic governing equations for saturated‐unsaturated groundwater flow in deforming true anisotropic geologic media and the Galerkin finite element method. A series of true anisotropic aquifers, which comprise variously tilting layers, respectively, and a corresponding isotropic aquifer, which is composed of a geometrically averaged equivalent isotropic material, are simulated for the purpose of comparison. The numerical simulation results show that true anisotropy has significant effects on the spatial distributions and temporal changes of hydraulic head and displacement vector. Such effects of true anisotropy are caused by the uneven partitioning of the hydraulic pumping stress between the vertical and horizontal directions in both groundwater flow and solid skeleton deformation fields. This directionally uneven partitioning of the hydraulic pumping stress results from both the differences in hydraulic and mechanical properties among the principal axes and the discordance between the global coordinate axes and the principal axes.
Voyager 2 observations related to the October–November 2003 solar events
Authors: Burlaga L. F. , Ness N. F. , Stone E. C. , McDonald F. B. , Richardson J. D.
Published: January 2005

A transient flow system observed at 1 AU from October 24–November 7, 2003 (consisting of several shocks, ejecta and possibly other flows) moved away from the Sun for ≈180 days to 73 AU, where Voyager 2 (V2) observed a large Merged Interaction Region (MIR) associated with a fast (560 km/s) stream that followed a forward shock and moved past V2 for ≈1.5 solar rotations. The MIR and stream were associated with a large decrease in the cosmic ray intensity and an exceptionally large enhancement in the flux of ≈2.5 MeV protons. The speed and the cosmic ray profiles observed by V2 were very simple, resembling the profiles of a shock/sheath/ejecta flow and a Forbush decrease, respectively, at 1 AU, but rescaled by a factor by a factor of ≈10. The onset of the MIR‐associated decrease in the cosmic ray intensity occurred 10 days after the shock, lasting several days, with a full recovery ≈70 days after the onset.
Response of the inner radiation belt to the violent Sun‐Earth connection events of October–November 2003
Authors: Looper M. D. , Blake J. B. , Mewaldt R. A.
Published: January 2005

We report observations of the response of the low‐altitude radiation population below L = 3 during and after the strong solar energetic particle events and geomagnetic disturbances of late October and early November 2003, and we place this response in the context of observations throughout the 12‐year SAMPEX mission. We find that on 29 October 2003, at the approximately 600 km altitude of SAMPEX, the usual belt of energetic protons (above 19 MeV) around L = 2 almost completely disappeared, recovering only after several months. We also observed the appearance of a new belt of ultrarelativistic (above 10 MeV) electrons centered around L = 2. In the previous twelve years, we have never observed such a large decrease of the energetic protons at low altitude. An injection of very high energy electrons like this has not been seen since February 1994.