bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationships, marketing and small business: an exploration of links in theory and practice
Authors: Zontanos Grigorios , Anderson Alistair R.
Published: January 2005

This paper explores the links between the theory and practices of marketing and small business. The review of the literature highlights the close association of the more advanced conceptualisations of marketing, especially relationship marketing, and those of small business, particularly entrepreneurial small business. Given these theoretical similarities and the ensuing symmetry of actions and behaviours described in theory, the research question is posed, how does an appreciation of these links aid our understanding of entrepreneurial practices? The question is addressed by employing a participant observation methodology to create a case study of one small rural firm and by inductive analysis techniques. The findings show that it is difficult to disentangle or even to distinguish, the practice of relationship marketing from entrepreneurial action. This leads one to suggest that it may be useful to reconsider relationship marketing as a facet of entrepreneurship.
Spectral magnitude effects on the analyses of secondary structure from circular dichroism spectroscopic data
Authors: Miles Andrew J. , Whitmore Lee , Wallace B.A.
Published: January 2005

The effects of spectral magnitude on the calculated secondary structures derived from circular dichroism (CD) spectra were examined for a number of the most commonly used algorithms and reference databases. Proteins with different secondary structures, ranging from mostly helical to mostly β‐sheet, but which were not components of existing reference databases, were used as test systems. These proteins had known crystal structures, so it was possible to ascertain the effects of magnitude on both the accuracy of determining the secondary structure and the goodness‐of‐fit of the calculated structures to the experimental data. It was found that most algorithms are highly sensitive to spectral magnitude, and that the goodness‐of‐fit parameter may be a useful tool in assessing the correct scaling of the data. This means that parameters that affect magnitude, including calibration of the instrument, the spectral cell pathlength, and the protein concentration, must be accurately determined to obtain correct secondary structural analyses of proteins from CD data using empirical methods.
Assessing predictions of protein–protein interaction: The CAPRI experiment
Authors: Janin Joël
Published: January 2005

The Critical Assessment of PRedicted Interactions (CAPRI) experiment was designed in 2000 to test protein docking algorithms in blind predictions of the structure of protein–protein complexes. In four years, 17 complexes offered by crystallographers as targets prior to publication, have been subjected to structure prediction by docking their two components. Models of these complexes were submitted by predictor groups and assessed by comparing their geometry to the X‐ray structure and by evaluating the quality of the prediction of the regions of interaction and of the pair wise residue contacts. Prediction was successful on 12 of the 17 targets, most of the failures being due to large conformation changes that the algorithms could not cope with. Progress in the prediction quality observed in four years indicates that the experiment is a powerful incentive to develop new procedures that allow for flexibility during docking and incorporate nonstructural information. We therefore call upon structural biologists who study protein–protein complexes to provide targets for further rounds of CAPRI predictions.
Helical structure determined by NMR of the HIV‐1 (345–392)Gag sequence, surrounding p2: Implications for particle assembly and RNA packaging
Authors: Morellet Nelly , Druillennec Sabine , Lenoir Christine , Bouaziz Serge , Roques Bernard P.
Published: January 2005

Gag protein oligomerization, an essential step during virus assembly, results in budding of spherical virus particles. This process is critically dependent on the spacer p2, located between the capsid and the nucleocapsid proteins. P2 contributes also, in association with NCp7, to specific recognition of the HIV‐1 packaging signal resulting in viral genome encapsidation. There is no structural information about the 20 last amino acids of the C‐terminal part of capsid (CA[CTD]) and p2, in the molecular mechanism of Gag assembly. In this study the structure of a peptide encompassing the 14 residues of p2 with the upstream 21 residues and the downstream 13 residues was determined by 1H NMR in 30% trifluoroethanol (TFE). The main structural motif is a well‐defined amphipathic α‐helix including p2, the seven last residues of the CA(CTD), and the two first residues of NCp7. Peptides containing the p2 domain have a strong tendency to aggregate in solution, as shown by gel filtration analyses in pure H2O. To take into account the aggregation phenomena, models of dimer and trimer formed through hydrophobic or hydrophilic interfaces were constructed by molecular dynamic simulations. Gel shift experiments demonstrate that the presence of at least p2 and the 13 first residues of NCp7 is required for RNA binding. A computer‐generated model of the Gag polyprotein segment (282–434)Gag interacting with the packaging element SL3 is proposed, illustrating the importance of p2 and NCp7 in genomic encapsidation.
Crystal structure of the complex formed between a group I Phospholipase A2 and a naturally occurring fatty acid at 2.7 Å resolution
Authors: Singh Garima , Jasti Jayasankar , Saravanan K. , Sharma Sujata , Kaur Punit , Srinivasan A. , Singh Tej P.
Published: January 2005

This is the first evidence of a naturally bound fatty acid to a group I Phospholipase A2 (PLA2) and also to a PLA2 with Asp 49. The fatty acid identified as n‐tridecanoic acid is observed at the substrate recognition site of PLA2 hydrophobic channel. The complex was isolated from the venom of Bungarus caeruleus (Common Indian Krait). The primary sequence of the PLA2 was determined using the cDNA method. Three‐dimensional structure has been solved by the molecular replacement method and refined using the CNS package to a final R factor of 19.8% for the data in the resolution range from 20.0 to 2.7 Å. The final refined model is comprised of 912 protein atoms, one sodium ion, one molecule of n‐tridecanoic acid, and 60 water molecules. The sodium ion is located in the calcium‐binding loop with a sevenfold coordination. A characteristic extra electron density was observed in the hydrophobic channel of the enzyme, into which a molecule of n‐tridecanoic acid was clearly fitted. The MALDI–TOF measurements of the crystals had earlier indicated an increase in the molecular mass of PLA2 by 212 Da over the native PLA2. A major part of the ligand fits well in the binding pocket and interacts directly with His 48 and Asp 49. Although the overall structure of PLA2 in the present complex is similar to the native structure reported earlier, it differs significantly in the folding of its calcium‐binding loop.
Intramolecular disulphide bond arrangements in nonhomologous proteins
Authors: Hartig Gerald R.S. , Tran Tran T. , Smythe Mark L.
Published: January 2005

The presence and location of intramolecular disulphide bonds are a key determinant of the structure and function of proteins. Intramolecular disulphide bonds in proteins have previously been analyzed under the assumption that there is no clear relationship between disulphide arrangement and disulphide concentration. To investigate this, a set of sequence nonhomologous protein chains containing one or more intramolecular disulphide bonds was extracted from the Protein Data Bank, and the arrangements of the bonds, Protein Data Bank header, and Structural Characterization of Proteins fold were analyzed as a function of intramolecular disulphide bond concentration. Two populations of intramolecular disulphide bond‐containing proteins were identified, with a naturally occurring partition at 25 residues per bond. These populations were named intramolecular disulphide bond‐rich and ‐poor. Benefits of partitioning were illustrated by three results: (1) rich chains most frequently contained three disulphides, explaining the plateaux in extant disulphide frequency distributions; (2) a positive relationship between median chain length and the number of disulphides, only seen when the data were partitioned; and (3) the most common bonding pattern for chains with three disulphide bonds was based on the most common for two, only when the data were partitioned. The two populations had different headers, folds, bond arrangements, and chain lengths. Associations between IDSB concentration, IDSB bonding pattern, loop sizes, SCOP fold, and PDB header were also found. From this, we found that intramolecular disulphide bond‐rich and ‐poor proteins follow different bonding rules, and must be considered separately to generate meaningful models of bond formation.
The crystal structure of an eukaryotic iron superoxide dismutase suggests intersubunit cooperation during catalysis
Authors: Muñoz Inés G. , Moran Jose F. , Becana Manuel , Montoya Guillermo
Published: January 2005

Superoxide dismutases (SODs) are a family of metalloenzymes that catalyze the dismutation of superoxide anion radicals into molecular oxygen and hydrogen peroxide. Iron superoxide dismutases (FeSODs) are only expressed in some prokaryotes and plants. A new and highly active FeSOD with an unusual subcellular localization has recently been isolated from the plant Vigna unguiculata (cowpea). This protein functions as a homodimer and, in contrast to the other members of the SOD family, is localized to the cytosol. The crystal structure of the recombinant enzyme has been solved and the model refined to 1.97 Å resolution. The superoxide anion binding site is located in a cleft close to the dimer interface. The coordination geometry of the Fe site is a distorted trigonal bipyramidal arrangement, whose axial ligands are His43 and a solvent molecule, and whose in‐plane ligands are His95, Asp195, and His199. A comparison of the structural features of cowpea FeSOD with those of homologous SODs reveals subtle differences in regard to the metal–protein interactions, and confirms the existence of two regions that may control the traffic of substrate and product: one located near the Fe binding site, and another in the dimer interface. The evolutionary conservation of reciprocal interactions of both monomers in neighboring active sites suggests possible subunit cooperation during catalysis.
Artificial neural networks for estimating soil hydraulic parameters from dynamic flow experiments
Authors: Schmitz G. H. , Puhlmann H. , Dröge W. , Lennartz F.
Published: January 2005

Inverse methods are often used for estimating soil hydraulic parameters from experiments on flow of water through soil. We propose here an alternative method using neural networks. We teach a problem‐adapted network of radial basis functions (RBF) the relationship between soil parameters and transient flow patterns using a numerical flow model. The trained RBF network accurately identifies soil parameters from flow patterns not contained in the training scenarios. A comparison with the inverse method (Annealing‐Simplex) reveals a similarly good prediction by both approaches for randomly perturbed data and data from the real world. Nonetheless, the inverse method showed dependency on initial parameter estimates not required by the RBF network. Training demands moderately more computation and manpower than the inverse technique, but the absolutely stable and simple network application requires negligible resources. Thus, for individual applications, the network approach is slightly surpassed by the Annealing‐Simplex method. However, the RBF network has to be trained only once and, subsequently, it can be applied easily and without effort upon any number of laboratory experiments with standardized experimental setups.
Redistribution of particulate organic matter during ultrasonic dispersion of highly weathered soils
Authors: Oorts K. , Vanlauwe B. , Recous S. , Merckx R.
Published: January 2005

The use of ultrasonic energy for the dispersion of aggregates in studies of soil organic matter (SOM) fractionation entails a risk of redistribution of particulate organic matter (POM) to smaller particle‐size fractions. As the mechanical strength of straw also decreases with increasing state of decomposition, it can be expected that not all POM will be redistributed to the same extent during such dispersion. Therefore, we studied the redistribution of POM during ultrasonic dispersion and fractionation as a function of (i) dispersion energy applied and (ii) its state of decomposition. Three soils were dispersed at different ultrasonic energies (750, 1500 and 2250 J g−1 soil) or with sodium carbonate and were fractionated by particle size. Fraction yields were compared with those obtained with a standard particle‐size analysis. Undecomposed or incubated (for 2, 4 or 6 months) 13C‐enriched wheat straw was added to the POM fraction (0.25–2 mm) of one of the soils before dispersion and fractionation. Dispersion with sodium carbonate resulted in the weakest dispersion and affected the chemical properties of the fractions obtained through its high pH and the introduction of carbonate. The mildest ultrasonic dispersion treatment (750 J g−1) did not result in adequate soil dispersion as too much clay was still recovered in the larger fractions. Ultrasonic dispersion at 1500 J g−1 soil obtained a nearly complete dispersion down to the clay level (0.002 mm), and it did not have a significant effect on the total amount of carbon and nitrogen in the POM fractions. The 2250 J g−1 treatment was too destructive for the POM fractions since it redistributed up to 31 and 37%, respectively, of the total amount of carbon and nitrogen in these POM fractions to smaller particle‐size fractions. The amount of 13C‐enriched wheat straw that was redistributed to smaller particle‐size fractions during ultrasonic dispersion at 1500 J g−1 increased with increasing incubation time of this straw. Straw particles incubated for 6 months were completely transferred to smaller particle‐size fractions. Therefore, ultrasonic dispersion resulted in fractionation of POM, leaving only the less decomposed particles in this fraction. The amounts of carbon and nitrogen transferred to the silt and clay fractions were, however, negligible compared with the total amounts of carbon and nitrogen in these fractions. It is concluded that ultrasonic dispersion seriously affects the amount and properties of POM fractions. However, it is still considered as an acceptable and appropriate method for the isolation and study of SOM associated with silt and clay fractions.
Measurement of the size distribution of water‐filled pores at different matric potentials by stray field nuclear magnetic resonance
Authors: Bird N. R. A. , Preston A. R. , Randall E. W. , Whalley W. R. , Whitmore A. P.
Published: January 2005

The water retention characteristic provides the traditional data set for the derivation of a soil's pore‐size distribution. However, the technique employed to achieve this requires that assumptions be made about the way pores interconnect. We explore an alternative approach based on stray field nuclear magnetic resonance (STRAFI‐NMR) to probe the water‐filled pores of both saturated and unsaturated soils, which does not require information relating to pore connectivity. We report the relative size distributions of water‐occupied pores in saturated and unsaturated samples of two sets of glass beads of known particle size, two sands, and three soils (a silty loam, a sandy loam and a loamy sand), using measurements of the NMRT1proton relaxation time of water. TheT1values are linearly related to pore size and consequently measuredT1distributions provide a measure of the pore‐size distribution. For both the sands and the glass beads at saturation theT1distributions are unimodal, and the samples with small particle sizes show a shift to smallT1values indicating smaller voids relative to the samples with larger particles. Different matric potentials were used to reveal how the water‐occupied pore‐size distribution changes during drainage. These changes are inconsistent with, and demonstrate the inadequacies of, the commonly employed parallel‐capillary tube model of a soil pore space. We find that not all pores of the same size drain at the same matric potential. Further, we observe that theT1distribution is shifted to smaller values beyond the distribution at saturation. This shift is explained by a change in the weighted average of the relaxation rates as the proportion of water in the centre of water‐filled pores decreases. This is evidence for the presence of pendular structures resulting from incomplete drainage of pores. For the soils the results are similar except that at saturation theT1distributions are bimodal or asymmetrical, indicative of inter‐aggregate and intra‐aggregate pore spaces. We conclude that the NMR method provides a characterization of the water‐filled pore space which complements that derived from the water retention characteristic and which can provide insight into the way pore connectivity impacts on drainage.
Changes in the microbial community of an arable soil caused by long‐term metal contamination
Authors: Abaye D. A. , Lawlor K. , Hirsch P. R. , Brookes P. C.
Published: January 2005

The effects of past applications of farmyard manure (FYM, applied from 1942 to 1967), metal‐contaminated sewage sludge (applied from 1942 to 1961) and mineral fertilizer (NPK, applied from 1942 until now) on the microbial biomass and community structure in a sandy loam, arable soil from the Woburn Market Garden Experiment, UK, were investigated in 1998. Concentrations of Cu, Ni and Zn in soils which previously received sewage sludge were less than current European Union (EU) limits, but the soil Cd concentration was more than twice the permitted limit. Organic‐C concentration in the FYM‐treated soil and contaminated soils was about twice that of NPK‐treated soil. The initial microbial biomass‐C and estimates of total bacterial numbers by acridine orange direct count were significantly (P < 0.05) greater in the FYM‐treated soil compared with the NPK‐treated and the most contaminated soils. Total phospholipid fatty acid (PLFA) concentration (another measure of biomass) was significantly greater in the FYM‐treated soil compared with either the low or high metal‐contaminated soils, both of which contained similar PLFA concentrations. In the metal‐contaminated soils, in contrast, fluorescent Pseudomonas counts, as a percentage of total plate counts, were at least 1.5 times greater than in the uncontaminated soils. The concentrations of these microbial parameters were significantly (P < 0.05) less in the NPK soil than in all the other treatments. Biomass‐C as a percentage of organic‐C was also significantly (P < 0.05) greater in the uncontaminated soils compared with the metal‐contaminated soils. Biomass specific respiration rates in the metal‐contaminated soils were c. 1.5 times those in the FYM‐treated soil. In the metal‐contaminated soils, the concentration of mono‐unsaturated and hydroxy‐fatty acids (derived from phospholipids), and lipopolysaccharide hydroxy‐fatty acids (all indicative of Gram‐negative bacteria) were significantly (P < 0.05) greater than branched fatty acids (indicative of Gram‐positive bacteria). Furthermore, Gram‐negative counts were 62–68% greater than Gram‐positive counts in the metal‐contaminated soils. Branched fatty acid concentration was significantly (P < 0.05) greater in the FYM‐treated soil than in the metal‐contaminated soils. Gram‐positive counts were also 63% greater than Gram‐negative counts in the FYM‐treated soil. We found that effects of the relatively small heavy metal concentration caused measurable decreases in soil microbial biomass‐C concentrations, acridine orange direct counts and Gram‐positive counts. There were also increases in biomass specific respiration rates, and the microbial community had changed substantially, nearly 40 years after the metal inputs ceased. We conclude that, at the very least, the current EU permitted limits for heavy metals in agricultural soils should not be relaxed.
Wavelet analysis of the scale‐ and location‐dependent correlation of modelled and measured nitrous oxide emissions from soil
Authors: Milne A. E. , Lark R. M. , Addiscott T. M. , Goulding K. W. T. , Webster C. P. , O'Flaherty S.
Published: January 2005

We used the wavelet transform to quantify the performance of models that predict the rate of emission of nitrous oxide (N2O) from soil. Emissions of N2O and other soil variables that influence emissions were measured on soil cores collected at 256 locations across arable land in Bedfordshire, England. Rate‐limiting models of N2O emissions were constructed and fitted to the data by functional analysis. These models were then evaluated by wavelet variance and wavelet correlations, estimated from coefficients of the adapted maximal overlap discrete wavelet transform (AMODWT), of the fitted and measured emission rates.

We estimated wavelet variances to assess whether the partition of the variance of modelled rates of N2O emission between scales reflected that of the data. Where the relative distribution of variance in the model is more skewed to coarser scales than is the case for the observation, for example, this indicates that the model predictions are too smooth spatially, and fail adequately to represent some of the variation at finer scales. Scale‐dependent wavelet correlations between model and data were used to quantify the model performance at each scale, and in several cases to determine the scale at which the model description of the data broke down. We detected significant changes in correlation between modelled and predicted emissions at each spatial scale, showing that, at some scales, model performance was not uniform in space. This suggested that the influence of a soil variable on N2O emissions, important in one region but not in another, had been omitted from the model or modelled poorly. Change points usually occurred at field boundaries or where soil textural class changed.

We show that wavelet analysis can be used to quantify aspects of model performance that other methods cannot. By evaluating model behaviour at several scales and positions wavelet analysis helps us to determine whether a model is suitable for a particular purpose.
Describing soil crack formation using elastic–plastic fracture mechanics
Authors: Hallett P. D. , Newson T. A.
Published: January 2005

Crack development is predominant in soil structure formation. A number of fracture mechanics models have been applied to soil to describe cracking, but most are not applicable for soil in a wet, plastic state. We address this weakness by applying a new elastic–plastic fracture mechanics approach to describe crack formation in plastic soil. Samples are fractured using a deep‐notch (modified four‐point) bend test, with data on load transmission, sample bending, crack growth, and crack‐mouth opening collected to assess the crack‐tip opening angle (CTOA). CTOA provides a powerful parameter for describing soil cracking since it can be induced by soil shrinkage (an easily measured parameter) and can be used to describe elastic–plastic fracture in numerical approximations, such as finite element modelling. The test variables we studied were the direction of the applied consolidation stress, clay content, and pore water salinity. All samples were formed by consolidating soil slurry one‐dimensionally with a 120‐kPa vertical effective stress. Tests on pure kaolinite showed that the direction of the consolidation stress did not affect CTOA, which was 0.23 ± 0.02 m m−1 for specimens cut both in a horizontal and in a vertical direction to the applied stress. Soil clay content had a marked influence, however, with silica sand:kaolinite mixtures by weight of 20:80 and 40:60 reducing CTOA to 0.14 ± 0.02 m m−1 and 0.12 ± 0.01 m m−1, respectively. These smaller values of CTOA indicate that less strain is required to induce fracture when the amount of clay is less. Salinity (0.5 m NaCl) caused a reduction in the CTOA of pure kaolinite from 0.23 ± 0.02 m m−1 to 0.17 ± 0.03 m m−1.
Respite care for caregivers and people with severe mental illness: literature review
Authors: Jeon Yun‐Hee , Brodaty Henry , Chesterson Jon
Published: January 2005

Aim. The aim of this study was to review research literature over the past 10 years on respite care for people affected by severe mental illness; and identify key implications for nursing practice in provision of respite care for family caregivers of people with severe mental illness.

Background. Family caregivers play an important role in health care, but need regular breaks to maintain their own health and well‐being. Respite care is one of the few services available with a primary focus on supporting family caregivers. In most developed countries the notion of respite care as an extension of the health care service has been embraced, evidenced by a growing body of literature in health and health‐related disciplines.

Methods. An initial literature search was undertaken using the key words ‘respite’, ‘short‐term care’, ‘shared care’ and ‘day care’ in major electronic databases for nursing, psychiatry, psychology and sociology literature between 1967 and 2002, identifying 704 articles. Closer examination of the literature from 1993 to 2002 on gaps and trends in respite care for people affected by severe mental illness was conducted. This is discussed in the context of the broader literature, particularly on dementia, where the mainstream research on respite care is found.

Results. The majority of family caregiving studies identified a need for greater quality, quantity, variety and flexibility in respite provision, and the literature has remained largely silent in relation to those affected by severe mental illness. There are contradictory findings on outcomes of respite care services and a lack of controlled empirical studies and evaluative research on effectiveness.

Conclusions. Respite care is beneficial for caregivers, there is significant unmet need in provision of services for the mentally ill, and greater flexibility and the needs of caregivers should be recognised and addressed.
Smoking among Japanese nursing students: nationwide survey
Authors: Suzuki Kenshu , Ohida Takashi , Yokoyama Eise , Kaneita Yoshitaka , Takemura Shinji
Published: January 2005

Aim.  This paper reports a study estimating the nationwide prevalence of and attitudes towards smoking among Japanese nursing students.

Background.  The World Health Organization established ‘World No Tobacco Day’ in 1987, and has been promoting antismoking measures worldwide since then, with annual themes. It has emphasized that health care professionals, including nurses, as role models for healthy living, should not smoke, and that as promoters of health education they should not seem to justify or condone their patients’ smoking. To promote antismoking measures among nurses, it will be necessary to scrutinize the smoking habits and behavior of nursing students and associated factors, and to conduct effective antismoking education and health education before they acquire the smoking habit.

Methods.  A cross‐sectional survey was carried out through self‐administered, closed‐ended, structured questionnaires. Questionnaires were mailed to 4169 nursing students at 27 randomly selected vocational nursing schools nationwide. Smoking status, history, and attitudes towards smoking were examined.

Results.  Smoking prevalence among female nursing students was 23·5%, which was higher than that among the Japanese general female population aged 20–29 (21·9%). Smoker‐students were significantly more positive toward smoking than non‐smokers in all opinions about health care professionals’ smoking. Multiple logistic regression analysis showed that smoking statuses of the people around the participants, dissatisfaction with being a nursing student, and living alone were associated with participants’ smoking behaviour.

Conclusions.  The results of the present study suggest an urgent necessity to provide effective antismoking measures for nursing students.
Creation of a multidisciplinary, evidence based, clinical guideline for the assessment, investigation and management of acute diabetes related foot complications
Authors: Wraight P. R. , Lawrence S. M. , Campbell D. A. , Colman P. G.
Published: January 2005

Aims To design a multidisciplinary, evidenced‐based, clinical guideline for the assessment, investigation and management of inpatients with acute diabetes related foot complications.

Methods A systematic search of both published (identified by searching all major electronic databases and hand searching key journals) and unpublished literature (derived from national and internationally recognized experts) identified 266 articles specific to diabetes related foot complications. Of these, 126 (47%) were assessed to be methodologically sound and clinically relevant. A narrative summary with the articles tabulated according to their level of evidence was prepared. A multidisciplinary expert group of health professionals, with a known interest and recognized expertise in diabetes related foot complications, was established to assess the evidence.

Results The multidisciplinary expert group used the identified literature and clinical experience to create a comprehensive, evidence‐based, clinical guideline for the assessment, investigation and management of acute diabetes related foot complications. Included within the guideline is a novel, diabetes specific classification system, which codes for the presence/absence and severity of the four principle causative factors (Neuropathy, Vascular compromise, Ulceration and Infection) in the development of acute diabetes related foot complications.

Conclusion Through the creation and implementation of this evidence‐based clinical guideline, specific for acute diabetes related foot complications, it is hoped that health professionals will be better equipped to make informed decisions for this patient population. This may benefit the individual and health system through reductions in amputation rate, length of hospital stay and health expenditure.
Increasing body weight predicts the earlier onset of insulin‐dependant diabetes in childhood: testing the ‘accelerator hypothesis’ (2)
Authors: Betts P. , Mulligan J. , Ward P. , Smith B. , Wilkin T.
Published: January 2005

Aims and methods  It has recently been hypothesized that weight gain in childhood accelerates the onset of Type 1 diabetes, as well as increasing its risk, and that Type 1 diabetes and Type 2 diabetes may be one and the same disorder of insulin resistance. An explanation is needed for the rising incidence of childhood diabetes and, to test the Accelerator Hypothesis, we examined the anthropometric measurements recorded from birth in 168 young people presenting with Type 1 diabetes between 1980 and 2002. Pre‐onset as well as peri‐ and post‐onset measurements of height and weight were available, and waist circumference was recorded at various intervals after onset.

Results  The mean birth weight of the children and their height, weight and body mass index (BMI) at diagnosis lay close to the population mean. However, pre‐onset and post‐onset BMI were both well above the population mean, were closely correlated with each other (r = 0.79, P < 0.001) and (inversely) with age at onset (r = −0.30, P < 0.001). A significant correlation was also found between BMI standard deviation scores (sds) and year of diagnosis (r = 0.27, P < 0.001) and, importantly, waist circumference sds in the children with Type 1 diabetes was found to be substantially greater than average for the population [boys: +0.96 (sd 1.04), girls: +1.30 (sd 0.89)].

Conclusions  The data suggest that children with Type 1 diabetes have become progressively heavier at diagnosis over the past 20 years, and that the heavier child develops it earlier. Waist circumference, a proxy for visceral fat mass and insulin resistance, is substantially greater in children with Type 1 diabetes. Weight centile crossing appears to be an important environmental accelerator which may contribute to or account for the striking increase in both Type 1 diabetes and Type 2 diabetes in childhood. A reduction of body weight and improved lifestyle might reverse this trend in both types of diabetes.
Psychiatric morbidity and health outcome in Type 1 diabetes – perspectives from a prospective longitudinal study
Authors: Northam E. A. , Matthews L. K. , Anderson P. J. , Cameron F. J. , Werther G. A.
Published: January 2005

Aims  To describe psychiatric status and relationship to metabolic control in adolescents with Type 1 diabetes studied prospectively from diagnosis.

Methods  Adolescents (n = 41) completed a self‐report measure of psychiatric status 10 years after disease onset. Metabolic control information was recorded prospectively from diagnosis. The rate and type of psychiatric disorder were determined and the relationship between mental health status and metabolic control history examined.

Results  Thirty‐seven per cent of the adolescents met criteria for a DSM‐IV psychiatric disorder, two to three times higher than community levels of psychiatric morbidity. Females were significantly more likely to receive a diagnoses (χ2 = 4.98, P < 0.05). Two thirds of participants had experienced at least one serious hypoglycaemic episode and one third had a history of chronic poor metabolic control. DSM‐IV diagnoses were present in half of those with a history of chronic poor control, one third of the hypoglycaemia group and one quarter of well controlled participants. Adolescents with a current Mood (t = −2.83, P < 0. 01), Anxiety (t = −3.77, P = 0.001) or Behaviour (t = 2.56, P < 0.05) disorder and those with a history of poorly controlled diabetes (F (2,29) = 5.4, P = 0.01) had higher externalizing behaviour problem scores at diagnosis than those without current disorder.

Conclusions  Adolescents with Type 1 diabetes are at high risk for psychiatric disorder. Poorly controlled diabetes over the first 10 years of illness was associated with pre‐existing behaviour problems at diagnosis and there was a trend for an association with current psychiatric status.
In‐hospital breast feeding rates among women with gestational diabetes and pregestational Type 2 diabetes in South Auckland
Authors: Simmons D. , Conroy C. , Thompson C. F.
Published: January 2005

Aim  To describe the uptake of breast feeding in mothers with either Type 2 diabetes or gestational diabetes (GDM) in a hospital serving a multiethnic community in South Auckland, New Zealand.

Research design and methods  A retrospective study of all women attending the Diabetes in Pregnancy clinic over a 4‐year period was undertaken: 30 women had Type 2 diabetes and 373 GDM.

Results  Compared with mothers with GDM, mothers with Type 2 diabetes were less likely to breast feed in any way as the first feed (41.4% vs. 68.0%, P = 0.011) or at discharge (69.0% vs. 84.0%, P = 0.039). In the combined group, there were no differences in uptake of breast feeding by ethnicity, age, parity, body mass index, smoking or antenatal glycaemia, use of insulin or presence of hypertension. Breast feeding on discharge was associated with a higher APGAR score, breast feeding as the first feed (78.2% vs. 19.4%, P < 0.001) and lower rates of delivery by Caesarean section (17.0% vs. 31.8%, P = 0.006). Logistic regression showed breast feeding as the first feed, the major determinant for breast feeding on discharge.

Conclusions  Factors delaying breast feeding as the first feed are the major determinant of breast feeding on discharge. Strategies to increase breast feeding as the first feed among women with Type 2 diabetes, and those having a Caesarean section, may be useful in increasing the uptake of breast feeding in the longer term.
Glycaemic and insulin responses of six traditional Sudanese carbohydrate‐rich meals in subjects with Type 2 diabetes mellitus
Authors: Abdelgadir M. , Abbas M. , Järvi A. , Elbagir M. , Eltom M. , Berne C.
Published: January 2005

Aims  The objective of this study was to investigate the influence of six Sudanese traditional carbohydrate‐rich meals on glucose and insulin responses and to formulate appropriate dietary guidelines based on glycaemic excursions of traditional foods.

Methods  On six occasions with 1‐week intervals, 10 Type 2 diabetic subjects consumed six Sudanese traditional carbohydrate‐rich meals. The following meals were tested and also analysed for their composition: wheat gorasa (pancakes), sorghum kisra (flat bread) and sorghum acida (porridge), millet kisra and millet acida and maize acida. Blood samples were collected before and after meal ingestion at 0, 30, 60, 120 and 240 min and analysed for plasma glucose and plasma insulin and incremental areas under the curves (AUC) were calculated.

Results  A significant variation in AUC for glucose and insulin responses were found between meals, the over all differences in incremental AUCs between the six meals were significant for both plasma glucose (P = 0.0092) and insulin (P = 0.0001). The 2‐h glucose values were 10.5 ± 2.7 for sorghum flatbread, 9.5 ± 3.1 for sorghum porridge, 10.3 ± 3.4 for millet flatbread, 10.6 ± 3.6 for millet porridge, 11.4 ± 2.7 for maize porridge and 8.7 ± 2.4 for the wheat pancakes. The comparison between the AUCs of the meals showed that millet acida (porridge) followed by wheat gorasa (pancakes) displayed significantly lower post‐prandial glucose and insulin responses, whereas maize acida induced a higher post‐prandial glucose and insulin response.

Conclusions  The comparison of glycaemic and insulin responses to six traditional Sudanese meals show differences of clinical importance, and could form a basis for dietary advice to diabetic subjects in Sudan and countries sharing similar food traditions.
NT‐proBNP in normoalbuminuric patients with Type 2 diabetes mellitus
Authors: Andersen N. H. , Poulsen S. H. , Knudsen S. T. , Heickendorff L. , Mogensen C. E.
Published: January 2005

Objective  To examine levels of NT‐proBNP and its relation to hypertension, as well as diastolic function in normoalbuminuric patients with Type 2 diabetes.

Research design and methods  The study comprised 60 Type 2 diabetic patients without albuminuria. Thirty patients were normotensive and 30 had hypertension. Exclusion criteria were cardiac symptoms and an ejection fraction < 55%. Thirty age‐ and sex‐matched normal subjects served as controls. Diastolic dysfunction was assessed with echocardiography, by means of mitral inflow and colour M‐Mode flow propagation recordings.

Results  Overall NT‐proBNP was significantly elevated in the Type 2 diabetes group, compared with the controls [54.5 pg/ml (5–162) vs. 32.7 pg/ml (5–74.3) P = 0.02]. NT‐proBNP was significantly higher among hypertensive patients compared with both normotensive patients and controls but no difference was found between the normotensive patients and the controls [58.0 pg/ml (8.5–162), P < 0.05 vs. 50.8 pg/ml (5–131) P = 0.4]. Patients with concentric and eccentric hypertrophy had significantly higher NT‐proBNP levels compared with the control group [81.0 pg/ml (5–147), P < 0.001 and 66.8 pg/ml (42–128), P < 0.001], whereas patients with left ventricular remodelling (enlarged relative wall diameter but normal left ventricular mass) were comparable with the control group [42.3 pg/ml (8.3–142) P = 0.55]. Patients with left atrial enlargement also had incremental NT‐proBNP values. NT‐proBNP was only moderately correlated to age (r = 0.33, P < 0.05) and left ventricular diastolic diameter (r = 0.41, P < 0.05), but unrelated to diastolic function.

Conclusions  NT‐proBNP is significantly increased in hypertensive, normoalbuminuric patients with Type 2 diabetes. These findings were related to left ventricular hypertrophy and increased left atrial and ventricular diameters.
Genetic Differences between Wild and Artificial Populations ofMetasequoia glyptostroboides: Implications for Species Recovery
Authors: LI YUAN‐YUAN , CHEN XIAO‐YONG , ZHANG XIN , WU TIAN‐YI , LU HUI‐PING , CAI YUE‐WEI
Published: January 2005

Abstract: Information on population genetics is fundamental to developing in situ or ex situ conservation strategies. Few researchers, however, have compared the genetic structure of restored and natural populations of threatened plant species.Metasequoia glyptostroboidesHu & Cheng (dawn redwood) (Taxodiaceae), a living fossil endemic to China, may be the most successfully recovered threatened species, with many more individuals and a much wider distribution than fossil records indicate. We used random amplification of polymorphic DNA markers to compare the genetic structure of artificial populations with that of wild ones and to determine whether the genetic structure ofM. glyptostroboideshas been recovered as has its distribution. The genetic variation of wild populations ofM. glyptostroboideswas lower than the average of gymnosperms, indicating the effects of glaciations and recent habitat loss and fragmentation. Genetic variation in artificial populations was less, but not substantially, compared with wild populations. The unweighted pair group method with arithmetic mean revealed that the wild and the artificial populations formed two distinct groups. Artificial populations were more similar to each other (mean Nei's genetic distance = 0.0924) than to wild populations (mean distance = 0.2054). This might be the result of biased seed collection, vegetative propagation, or a mixture of propagules from different populations and an ultimate propagule source. These results suggest that although the quantity and distribution range have been successfully restored, the genetic structure ofM. glyptostroboideshas not recovered appropriately, given the loss of genetic variation and biased genetic composition in artificial populations. Therefore, in addition to protecting the wild populations, additional ex situ genetic reserves should be established based on genetic knowledge and via appropriate approaches. We suggest that population genetic and demographic indices should be considered when downlisting or delisting threatened species.
Higher Taxa as Surrogates of Plant Biodiversity in a Megadiverse Country
Authors: VILLASEÑOR JOSE L. , IBARRA‐MANRÍQUEZ GUILLERMO , MEAVE JORGE A. , ORTÍZ ENRIQUE
Published: January 2005

Abstract: An important question in conservation biology is the extent to which the number of taxonomic supraspecific categories can serve as surrogates of species richness. This issue has been little explored in highly diverse areas. We used 113 floristic inventories from throughout Mexico, a megadiverse country, to evaluate the potential of higher‐taxon richness for predicting local species richness of vascular plants. This large biodiversity data set includes the main vegetation types found across the country. In all, 247 families, 2,398 genera, and 11,890 species were used for the analysis, representing 99.6%, 90.2%, and 53.2% of the respective totals recorded in the country. We hypothesized that the number of genera and species would be accurately predicted by the richness of the higher taxon. To avoid getting spurious regressions resulting from the logical increase in lower‐taxon richness as a higher taxon becomes richer, we calculated new response variables by subtracting from the number of elements in the lower taxon group the number of those in the higher taxon; these variables were “excess species” (number of species minus number of genera or families) and “excess genera” (number of genera minus number of families). Our results indicate that genera provide very effective surrogates for estimation of local species richness (R2= 0.85), whereas families have a more limited potential for this purpose (R2= 0.64). The predictive capacity of the diversity of higher taxon increased when the analyses were constrained to particular vegetation types (maximum R2= 0.95 for genera). This surrogate method may be a valuable tool in locating and designing representative systems of protected areas for vascular plant diversity, especially in megadiverse countries, where conservation efforts are hindered by the lack of complete inventories and insufficient resources.
Role of Prices and Wealth in Consumer Demand for Bushmeat in Gabon, Central Africa
Authors: WILKIE DAVID S. , STARKEY MALCOLM , ABERNETHY KATE , EFFA ERNESTINE NSTAME , TELFER PAUL , GODOY RICARDO
Published: January 2005

Abstract:  Unsustainable hunting of wildlife for food is often a more immediate and significant threat to the conservation of biological diversity in tropical forests than deforestation. Why people eat wildlife is debated. Some may eat bushmeat because they can afford it; others may eat it because it is familiar, traditional, confers prestige, tastes good, or adds variety. We completed a survey of 1208 rural and urban households in Gabon, Africa, in 2002–2003 to estimate the effect of wealth and prices on the consumption of wildlife and other sources of animal protein. Consumption of bushmeat, fish, chicken, and livestock increased with increasing household wealth, and as the price of these commodities rose, consumption declined. Although the prices of substitutes for bushmeat did not significantly, in statistical terms, influence bushmeat consumption, as the price of wildlife increased and its consumption fell, the consumption of fish rose, indicating that fish and bushmeat were dietary substitutes. Our results suggest that policy makers can use economic levers such as taxation or supply reduction through better law enforcement to change demand for wildlife. These measures will help to regulate unsustainable exploitation and reduce the risk of irreversible loss of large‐bodied and slow‐reproducing wildlife species. If policy makers focus solely on reducing the unsustainable consumption of wildlife, they may see adverse impacts on the exploitation of fish. Furthermore, policy makers must ensure that raising household wealth through development assistance does not result in undesirable impacts on the conservation status of wildlife and fish.
Effects of Human Exclusion on Parasitism in Intertidal Food Webs of Central Chile
Authors: LOOT GÉRALDINE , ALDANA MARCELA , NAVARRETE SERGIO A.
Published: January 2005

Abstract:  Numerous ecological studies have demonstrated the dramatic effects that humans have on coastal marine ecosystems. Consequently, marine reserves have been established to preserve biodiversity. Recent reviews show that this strategy has paid off because inside reserves, most species have rapidly increased in size and abundance. Even though these studies focused on free‐living organisms and paid little attention to parasite populations, numerous authors support the hypothesis that parasitism levels could be good indicators of ecosystem stability. We examined harvesting effects on the dynamics of a parasitic trematode ( Proctoeces lintoni) that completes its life cycle in intertidal mussels ( Perumytilus purpuratus), keyhole limpets (Fissurella crassa), and clingfish ( Sicyases sanguineus). All of these species are directly or indirectly affected by humans. Prevalence and abundance of the trematode P. lintoni in the three host species were compared in four study sites that differed in the intensity of human harvest. Parasitism infection in limpets and mussels was significantly higher in areas protected from human harvesting than in open‐access areas, which suggests a significant change in parasite dynamics inside reserves. Yet the average parasitic biomass found in the gonads of F. crassa did not differ between protected and open‐access areas. These results show, then, that the parasite system responded by increasing infection rates in marine protected areas without implication for reproductive success of the intermediate host. Our findings show that the indirect effects of harvesting by humans on the embedded parasite communities of littoral ecosystems require further scientific investigation.