bluuebunny/crossref_metadata_2025 huggingface dataset:
Exposure to pesticides impairs the expression of fish ornaments reducing the availability of attractive males
Authors: Arellano-Aguilar Omar , Macías Garcia Constantino
Published: March 2008

Ornament magnitude often reflects a local balance between sexual selection and other sources of natural selection opposing their elaboration. Human activity may disrupt this balance if it modifies the costs of producing, maintaining or displaying the ornaments. When costs are increased, a shortage of acceptable partners may ensue, with consequences commensurate with how stringent (and effective) the process of mate choice is. Here, we show that the expression of ornaments in the viviparous amarillo fish (
Girardinichthys multiradiatus
) is influenced by embryonic exposure to low concentrations of an organophosphorus insecticide. Male ornamental fin size, dimorphic yellow coloration and display rates were all compromised in exposed fish, but unaffected in their paternal half-sibling controls and in their sisters (morphology and colour). Exposure resulted in smaller fish of both sexes, thus the differential effect by sex was restricted to attributes such as fin size only above the naturally selected magnitude shown by females. Father phenotype predicted offspring morphology of controls, but not of exposed males, which were discriminated against by both control and exposed females. Since stringent female mate choice can result in females refusing to mate with suboptimal mates, this sub-lethal developmental effect can reduce the effective population size of amarillo fish populations.
Global-scale predictions of community and ecosystem properties from simple ecological theory
Authors: Jennings Simon , Mélin Frédéric , Blanchard Julia L , Forster Rodney M , Dulvy Nicholas K , Wilson Rod W
Published: March 2008

We show how theoretical developments in macroecology, life-history theory and food-web ecology can be combined to formulate a simple model for predicting the potential biomass, production, size and trophic structure of consumer communities. The strength of our approach is that it uses remote sensing data to predict properties of consumer communities in environments that are challenging and expensive to sample directly. An application of the model to the marine environment on a global scale, using primary production and temperature estimates from satellite remote sensing as inputs, suggests that the global biomass of marine animals more than 10
−5
 g wet weight is 2.62×10
9
 t (=8.16 g m
−2
ocean) and production is 1.00×10
10
 t yr
−1
(31.15 g m
−2
 yr
−1
). Based on the life-history theory, we propose and apply an approximation for distinguishing the relative contributions of different animal groups. Fish biomass and production, for example, are estimated as 8.99×10
8
 t (2.80 g m
−2
) and 7.91×10
8
 t yr
−1
(2.46 g m
−2
 yr
−1
), respectively, and 50% of fish biomass is shown to occur in 17% of the total ocean area (8.22 g m
−2
). The analyses show that emerging ecological theory can be synthesized to set baselines for assessing human and climate impacts on global scales.
The effects of gas flow on granular currents
Authors: Gilbertson M.A , Jessop D.E , Hogg A.J
Published: March 2008

Currents of particles have been quite successfully modelled using techniques developed for fluid gravity currents. These models require the rheology of the currents to be specified, which is determined by the interaction between particles. For relatively small slow currents, this is determined primarily through friction, which can be controlled and reduced by fluidizing the particles, so that they may become much more mobile. Recent results cannot be predicted using many of the proposed models, and may be defined by the interaction between the particles and the fluid through which they are passing. However, in addition, particles that are only initially fluidized also form currents that are also mobile, but otherwise are different from continuously fluidized currents. The mobility of these currents appears not to be connected to the time taken for them to degas. This suggests that defining the continuous stresses on the particle current may not be sufficient to understand its motion and that a challenge for the future is to understand the structure of these flows and how this affects their motion.
Wake attenuation in large Reynolds number dispersed two-phase flows
Authors: Risso Frédéric , Roig Véronique , Amoura Zouhir , Riboux Guillaume , Billet Anne-Marie
Published: March 2008

The dynamics of high Reynolds number-dispersed two-phase flow strongly depends on the wakes generated behind the moving bodies that constitute the dispersed phase. The length of these wakes is considerably reduced compared with those developing behind isolated bodies. In this paper, this wake attenuation is studied from several complementary experimental investigations with the aim of determining how it depends on the body Reynolds number and the volume fraction
α
. It is first shown that the wakes inside a homogeneous swarm of rising bubbles decay exponentially with a characteristic length that scales as the ratio of the bubble diameter
d
to the drag coefficient
C
d
, and surprisingly does not depend on
α
for 10
−2
≤
α
≤10
−1
. The attenuation of the wakes in a fixed array of spheres randomly distributed in space (
α
=2×10
−2
) is observed to be stronger than that of the wake of an isolated sphere in a turbulent incident flow, but similar to that of bubbles within a homogeneous swarm. It thus appears that the wakes in dispersed two-phase flows are controlled by multi-body interactions, which cause a much faster decay than turbulent fluctuations having the same energy and integral length scale. Decomposition of velocity fluctuations into a contribution related to temporal variations and that associated to the random character of the body positions is proposed as a perspective for studying the mechanisms responsible for multi-body interactions.
On the unsteady inviscid force on cylinders and spheres in subcritical compressible flow
Authors: Parmar M , Haselbacher A , Balachandar S
Published: March 2008

The unsteady inviscid force on cylinders and spheres in subcritical compressible flow is investigated. In the limit of incompressible flow, the unsteady inviscid force on a cylinder or sphere is the so-called added-mass force that is proportional to the product of the mass displaced by the body and the instantaneous acceleration. In compressible flow, the finite acoustic propagation speed means that the unsteady inviscid force arising from an instantaneously applied constant acceleration develops gradually and reaches steady values only for non-dimensional times
c

∞

t
/
R
≳10, where
c

∞

is the freestream speed of sound and
R
is the radius of the cylinder or sphere. In this limit, an effective added-mass coefficient may be defined. The main conclusion of our study is that the freestream Mach number has a pronounced effect on both the peak value of the unsteady force and the effective added-mass coefficient. At a freestream Mach number of 0.5, the effective added-mass coefficient is about twice as large as the incompressible value for the sphere. Coupled with an impulsive acceleration, the unsteady inviscid force in compressible flow can be more than four times larger than that predicted from incompressible theory. Furthermore, the effect of the ratio of specific heats on the unsteady force becomes more pronounced as the Mach number increases.
Introduction
Authors: Eames I
Published: March 2008

Dispersed multiphase flows—the study of the individual or collective motion of a discrete (solid/liquid/gas) phase in a continuous (liquid/gas) phase—has broad implications for health physics, processes in the natural environment, new technological developments (microelectromechanical systems) and many industrial problems. Many of these processes are important in our daily activities. In this paper, a general overview of the papers in this Theme Issue is described and some of the common issues are identified.
Ungulate and topographic control of nitrogen: phosphorus stoichiometry in a temperate grassland; soils, plants and mineralization rates
Authors: Frank Douglas A.
Published: March 2008

Although the link between the nitrogen (N): phosphorus (P) stoichiometry of biota and availability has received considerable attention in aquatic systems, there has been relatively little effort to compare the elemental composition of biota and supply in terrestrial habitats. In this study, I explored the effects of a prominent topo‐edaphic gradient, from dry hilltop to wet slope‐base, and native ungulates on N and P of soils, plants, and rates of in situ net mineralization in grasslands of Yellowstone National Park. Nitrogen and P measurements were made May–September, 2000, in paired, grazed and 38–42 year fenced, ungrazed grassland at five topographically variable sites. Similar to findings from other grassland ecosystems, several site factors associated with organic activity, including soil moisture, C, and plant biomass, covaried with soil N concentration and/or net N mineralization. Soil P concentration and net P mineralization, however, were unrelated to those factors. Instead, net P mineralization was negatively related to soil pH, which is known to control the form of inorganic P and its availability, and soil P was uncorrelated with any soil or plant variable measured in the study. Because of being influenced by different soil properties, N and P net mineralization were unrelated among grasslands. Furthermore, supply and plant N:P ratios were uncorrelated in this grassland system. Based on critical N:P ratios reflecting nutritional limitation of plants, Yellowstone grassland vegetation ranged from being N limited to N‐P co‐limited. Grazers increased N‐P co‐limitation by enhancing plant N concentrations and the soil pH gradient across grassland sites regulated plant nutritional limitation by affecting plant‐available P. These findings showed how ungulates and a landscape factor, i.e. soil pH, determined plant nutrient status among YNP grasslands differently by influencing plant N concentration versus plant P concentration, respectively.
Separate and interacting effects of deer florivory and salinity stress on iris herbivores
Authors: George Wang H. , Mopper Susan
Published: March 2008

Most herbivore studies focus on foliage feeders, despite the potentially strong impact of florivores on plant fitness and ecological communities. Vertebrate florivory is particularly noteworthy because it destroys the inflorescence, and may affect the community of floral arthropods. Strong biotic forces such as florivory can be influenced by abiotic forces. For example, field studies indicate that white‐tailed deer Odocoileus virginianus consume up to 90% of all flowers produced in Iris hexagona populations that inhabit high salinity wetlands, whereas freshwater iris populations suffer relatively little damage. We conducted a common garden experiment to investigate the potential effects of vertebrate florivory and salinity on two iris herbivores, the leafminer Cerodontha iridiphora, and the verbena bud moth, Endothenia hebesana. We administered four levels of florivory: zero (control), one, two, and three flowers removed per stalk, and applied three levels of salinity (0, 4 and 8 parts per thousand NaCl) in a full‐factorial design. Florivory and salinity had separate and interacting effects on herbivore performance. Salinity was more detrimental to herbivores than florivory, which was beneficial at low levels. A positive effect of moderate salinity on sexual reproduction was reversed by florivory. Our research reveals complex interactions between environmental stress and florivory, an understudied form of herbivory. These interactions have implications for wetland ecological communities that are increasingly exposed to biotic and abiotic stress.
Herbivores as architects of savannas: inducing and modifying spatial vegetation patterning
Authors: De Knegt Henrik J. , Groen Thomas A. , Van De Vijver Claudius A. D. M. , Prins Herbert H. T. , Van Langevelde Frank
Published: March 2008

In this paper, we address the question whether and through which mechanisms herbivores can induce spatial patterning in savanna vegetation, and how the role of herbivory as a determinant of vegetation patterning changes with herbivore density and the pre‐existing pattern of vegetation. We thereto developed a spatially explicit simulation model, including growth of grasses and trees, vertical zonation of browseable biomass, and spatially explicit foraging by grazers and browsers. We show that herbivores can induce vegetation patterning when two key assumptions are fulfilled. First, herbivores have to increase the attractiveness of a site while foraging so that they will revisit this site, e.g. through an increased availability or quality of forage. Second, foraging should be spatially explicit, e.g. when foraging at a site influences vegetation at larger spatial scales or when vegetation at larger spatial scales influences the selection and utilisation of a site. The interaction between these two assumptions proved to be crucial for herbivores to produce spatial vegetation patterns, but then only at low to intermediate herbivore densities. High herbivore densities result in homogenisation of vegetation. Furthermore, our model shows that the pre‐existing spatial pattern in vegetation influences the process of vegetation patterning through herbivory. However, this influence decreases when the heterogeneity and dominant scale of the initial vegetation decreases. Hence, the level of adherence of the herbivores to forage in pre‐existing patches increases when these pre‐existing patches increase in size and when the level of vegetation heterogeneity increases. The findings presented in this paper, and critical experimentation of their ecological validity, will increase our understanding of vegetation patterning in savanna ecosystems, and the role of plant–herbivore interactions therein.
Non‐additive, identity‐dependent effects of detrital species mixing on soft‐sediment communities
Authors: Bishop Melanie J. , Kelaher Brendan P.
Published: March 2008

Accelerating rates of species extinction and invasion have sparked recent interest in how changes in plant community composition can be propagated through food webs. Research in this area has, however, been largely restricted to considerations of how detrital species mixing affects litter decay processes. The consequences of changing detrital resources for whole assemblages of sediment‐dwelling invertebrates remain largely unknown. We manipulated the availability of three detrital sources, Avicennia marina leaves, Posidonia australis blades and Sargassum sp. thalli, on an Australian mudflat to test hypotheses about how changes in the type and number of macrophytes contributing to detrital resources might impact benthic invertebrate assemblages of estuarine soft‐sediments. By controlling for changes in total detrital biomass and ensuring that each detrital source was present in two‐ and three‐species mixes as well as monocultures, our experimental design was able to distinguish among effects of mixing, identity and biomass. Three months after detrital manipulation, macroinvertebrate abundance and species richness differed among treatments according to the biomass of detritus added and non‐additive effects of detrital species mixing. Whereas the mixing of two detrital species generally had an antagonistic effect on macroinvertebrate abundance and richness, faunal assemblages did not appreciably differ between three‐species mixes and monocultures. Generally negative effects of two‐species mixes on macroinvertebrates were opposed by positive effects on microphytobenthos, an important food‐source for many of the animals. Non‐additive effects on sediment communities were particularly apparent when Sargassum sp., the most labile of the three detrital sources considered, was included in two‐species mixes. This demonstration of non‐additive and identity‐dependent effects of detrital species mixing on soft‐sediment communities suggests that predicted compositional changes to aquatic macrophyte communities, resulting from coastal development and climate change, will flow on to effect other components of the estuarine food‐web.
Invertebrate predators drive distance‐dependent patterns of seedling mortality in a temperate tree Acer pseudoplatanus
Authors: Pigot Alex L. , Leather Simon R.
Published: March 2008

There is growing evidence that distance‐ and density‐dependent recruitment are important factors in structuring tree communities in temperate forests. Although pathogens have generally been assumed to be driving these patterns, few studies have attempted to experimentally identify the agent responsible. Here we investigate patterns of recruitment in sycamore Acer pseudoplatanus, a temperate tree species, in its exotic range in Britain. Seedling mortality, the limiting stage in sycamore regeneration, was monitored with respect to the proximity and density of adult sycamores and seedlings in a grid of sampling units. We found that mortality was significantly greater beneath adult sycamores compared with heterospecifics, and was further elevated in areas of high conspecific basal area, a proxy for biomass. An experimental approach that manipulated the access of predators to seedlings demonstrated that herbivorous invertebrates were responsible for driving these distance‐ and biomass‐dependent trends in mortality. Evidence of stem damage on dead seedlings suggests that slugs are the principal cause of mortality, although there was only partial evidence of higher slug activity beneath sycamores. The implications of these findings for sycamore invasion, species co‐existence and management are discussed.
Evidence on the Impact of Internal Control and Corporate Governance on Audit Fees
Authors: Hay David , Knechel W. Robert , Ling Helen
Published: March 2008

Previous studies generally suggest that internal control and external auditing can substitute for each other, so that better internal control will be associated with lower audit fees. However, their empirical results do not support this view. In contrast, previous studies of the interaction between corporate governance and external audit services often assume that they are complementary, and that improved governance is associated with higher audit fees, although the evidence about this issue is also mixed. We examine whether the ‘substitution’ or ‘complementary controls’ views apply. We find that measures of internal auditing, corporate governance, and concentration of ownership are all positively related to audit fees, consistent with the explanation that controls are complementary. The study makes a contribution by assisting regulators in understanding the effects of regulation of corporate governance, and by showing auditors and auditing standard setters that the view that internal controls can substitute for external auditing may not be helpful. We also find that these relationships hold only in a relatively less‐regulated environment.
Audit Committees and Voluntary External Auditor Involvement in UK Interim Reporting
Authors: Mangena Musa , Tauringana Venancio
Published: March 2008

The study investigates the relationship between audit committee characteristics and the decision to engage external auditors to review published interim reports. The motivation for the study derives from the consensus notion that the audit committee enhances the quality of financial reporting. Using interim reports of 258 UK listed companies published in the period 2001–2002, the results of logistic regression analyses show that the likelihood of engaging an external auditor to review interim reports increases with audit committee independence and financial expertise and decreases with share ownership by audit committee members. The results show that audit committee size and the number of audit committee meetings are not significantly associated with the decision to engage auditors in interim reporting. Taken overall, these findings suggest that an effective audit committee is associated with a review of interim reports by external auditors.
Infection of primary cultures of murine splenic and thymic cells with coxsackievirus B4
Authors: Jaïdane Hela , Gharbi Jawhar , Lobert Pierre‐Emmanuel , Caloone Delphine , Lucas Bernadette , Sané Famara , Idziorek Thierry , Romond Marie‐Bénédicte , Aouni Mahjoub , Hober Didier
Published: March 2008

Infection of primary cultures of total splenic and thymic cells from BALB/c and C3H/HeN mice with CVB4 E2 and JVB strains has been investigated. The presence of positive‐strand viral RNA within cells was determined by semi‐nested RT‐PCR, and viral replication was attested by detection of intracellular negative‐strand viral RNA and by release of infectious particles in culture supernatants. Viral replication occurred with both CVB4 strains to an extent dependent on the genetic background of the host. No interferon‐α production was detected in the supernatants of CVB4‐infected cultures using biological titration. Together these results suggest that infection of splenic and thymic cells can play a role in virus dissemination, and therefore in the pathophysiology of CVB4 infections.
Expression of interferon‐stimulated gene 20 in vascular endothelial cells
Authors: Imaizumi Tadaatsu , Mechti Nadir , Matsumiya Tomoh , Sakaki Hirotaka , Kubota Kosei , Yoshida Hidemi , Kimura Hiroto , Satoh Kei
Published: March 2008

ISG20 is an ribonuclease specific for single‐stranded RNA and considered to play a role in innate immunity against virus infections. We herein show that both poly IC, an authentic double‐stranded RNA, and IFN‐γ induced ISG20 expression in cultured HUVEC. Poly IC‐induced ISG20 expression was inhibited by LY294002, an inhibitor of PI3K, or by RNA interference against IFN regulatory factor three. ISG20 expression was not induced by IFN‐β, loxoribine or CpG oligonucleotide. These results suggest that ISG20 induction by poly IC may not be dependent on the IRF‐3‐mediated type I IFN induction pathway in HUVEC. ISG20 may be involved in innate immunity against viral infection in vascular endothelial cells.
Detection ofStreptobacillusspp. in feral rats by specific polymerase chain reaction
Authors: Kimura Masanobu , Tanikawa Tsutomu , Suzuki Michio , Koizumi Nobuo , Kamiyama Tsuneo , Imaoka Koichi , Yamada Akio
Published: March 2008

Streptobacillus moniliformisis an etiological agent of rat‐bite fever and Haverhill fever in human infection. As the currently available methods for identifying the causative bacteria are not satisfactory, we attempted to establish them by PCR using newly designed primers for the 16S rRNA gene ofS. moniliformis.We then determined the prevalence ofStreptobacillusspp. in two species of feral rats that inhabit an urban region in Japan, because information on the prevalence of the bacteria in feral rats is obscure. The use of PCR with newly designed primers showed that an extremely high proportion ofR. norvegicusharbored the bacteria (61/66, 92%), whereas the prevalence was only 58% inR. rattus(30/52). The nucleotide sequence analysis of the 16S rRNA gene ofStreptobacillusspp. isolated from oral swabs of feral rats showed at least two different types of bacteria among isolates fromR. norvegicusandR. rattus.
Low expression of ZHX2, but not RCBTB2 or RAN, is associated with poor outcome in multiple myeloma
Authors: Armellini A. , Sarasquete M. E. , García‐Sanz R. , Chillón M. C. , Balanzategui A. , Alcoceba M. , Fuertes M. , López R. , Hernández J. M. , Fernández‐Calvo J. , Sierra M. , Megido M. , Orfão A. , Gutiérrez N. C. , González M. , San Miguel J. F.
Published: March 2008

RAN, ZHX2 and RCBTB2 (CHC1L) expression was evaluated by quantitative real time reverse transcription polymerase chain reaction in plasma cells from 85 monoclonal gammopathies: 58 symptomatic multiple myeloma (MM) (52 untreated, six relapsed), eight smouldering MM, five monoclonal gammopathy of undetermined significance, four plasma cell leukaemias and 10 myeloid cell lines. ZHX2 was weakly expressed in high‐risk/proliferative disease compared to low‐risk or indolent disease. High ZHX2 expression was associated with better response and longer survival after high‐dose therapy. RCBTB2 expression was weaker in hyperdiploid versus non‐hyperdiploid cases while RAN was more expressed in symptomatic MM and cell lines.
Heterogeneous response of nasal and lung fibroblasts to transforming growth factor‐β1
Authors: Nonaka M. , Pawankar R. , Fukumoto A. , Yagi T.
Published: March 2008

Background
Nasal polyposis is characterized by marked oedema, sparse extracellular matrix (ECM) and proliferating blood vessels. Pulmonary fibrosis is characterized by inflammatory cells accumulation, considerable ECM deposition and vascular abnormalities. Although lung fibrosis is not only and necessarily an inflammatory disorder, we hypothesized that the difference between nasal polyposis and pulmonary fibrosis may, in part, be due to the heterogeneity between nasal and lung fibroblasts. Fibroblasts participate in the inflammatory response by releasing ECM proteins and cytokines. TGF‐β is thought to participate in chronic inflammation and fibrosis. Myofibroblasts are the activated form of fibroblasts. A phenotypic hallmark of myofibroblasts is the expression of smooth muscle α‐actin (SMA).

Objective
We examined whether there is any heterogeneity between nasal and lung fibroblasts upon stimulation with TGF‐β1 with regard to the synthesis of SMA, pro‐collagen type I and vascular endothelial growth factor (VEGF) as well as translocation of Smad proteins.

Methods
Fibroblasts lines were established from human biopsy tissue. The expression of SMA, pro‐collagen type I, VEGF mRNA was evaluated by reverse transciptase RT‐PCR. The amount of pro‐collagen type I and VEGF was measured by ELISA. By immunocytochemistry, we analysed the expression of SMA and Smad2, 3, 4 in cultured fibroblasts.

Results
TGF‐β1 induced SMA and pro‐collagen type I synthesis in lung, but not in nasal fibroblasts. By contrast, TGF‐β1 induced VEGF synthesis in both lung and nasal fibroblasts. After stimulation with TGF‐β1, Smad2, 3, 4 were translocated from the cytoplasm to the nucleus in lung fibroblasts, whereas only Smad3 was translocated in nasal fibroblasts.

Conclusion
These results establish the heterogeneous responsiveness of fibroblast populations in the airways to TGF‐β1 and that such a heterogeneity may contribute, at least in part, to the different pathological outcomes of inflammation in the upper and lower airways.
Birth order, atopy, and symptoms of allergy and asthma among inner‐city children attending Head Start in New York City
Authors: Perzanowski M. S. , Canfield S. M. , Chew G. L. , Mellins R. B. , Hoepner L. A. , Jacobson J. S. , Goldstein I. F.
Published: March 2008

Background
In past research, children with older siblings were more likely than others to wheeze at age 2 years, but less likely by age 6 years. Higher infection transmission and a down‐regulated allergic immune response as a result of these infections, respectively, were suggested as the causes. However, in a study of children aged 0–3 years in a low‐income urban community in New York City, USA, with high asthma prevalence, we observed no birth‐order effect.

Objective
To evaluate the association between birth order and atopy and respiratory symptoms in 4‐year‐old children attending Head Start programs in NYC.

Methods
Respiratory symptoms were assessed by questionnaire for 1005 children (mean age 4.0 years) living in high asthma prevalence neighbourhoods. Serum was collected from a subgroup of the children (n=494) and specific IgE responses to dust mite, cockroach, mouse, and cat allergens were measured.

Results
Prevalence of specific IgE (0.35 IU/mL) did not differ significantly among first (35%), second (35%), and later‐born children (28%) (P=0.23). Increasing birth order was associated with increasing prevalence of respiratory symptoms in the prior year, including wheeze (first 20%, second 27%, third or later 35%; P<0.001), being awakened at night by cough (28%, 33%, 38%; P=0.005), emergency department visits (14%, 17%, 21%; P=0.02) and hospitalizations for difficulty breathing (6.1%, 6.6%, 10%; P=0.04). The associations of birth order with respiratory symptoms were statistically significant only for the non‐seroatopic children and those without an asthmatic parent.

Conclusions
Non‐seroatopic children with older siblings were more likely than those without older siblings to have respiratory symptoms at age 4 years. Although the stability of these associations over time remains to be determined, the differences in findings between this study and our previous NYC birth cohort study suggest that patterns of asthma development may vary even among low‐income populations within the same city.
ANALYSIS OF TSH RECEPTORS AND MICROSOMAL ANTIGEN IN DIFFERENT HUMAN THYROID TISSUE SPECIMENS
Authors: FURMANIAK J. , DAVENPORT S. , NAKAJIMA Y. , KAISER U. , MULLER‐GARTNER H.W. , BUCKMANN F. W. , PEGG C. , SMITH B. REES
Published: March 2008

Affinity labelling with a 125I‐labelled photoactive derivative of TSH (HSAB‐TSH) was used to analyse TSH receptor size in the following specimens of human thyroid tissue: (1) cold nodules; (2) autonomous nodules; (3) papillary carcinoma; (4) medullary carcinoma; (5) metastasis of papillary carcinoma to lymph node; (6) anaplastic carcinoma, and (7) Graves' thyroid. In addition, a sample of histologically normal thyroid tissue surrounding specimens 1–4 was analysed in each case. Thyroid microsomes were also prepared from the tissue samples, solubilized using 1% deoxycholate and labelled with 125I. The preparations were immunoprecipitated using microscomal autoantibodies and protein A and analysed by SDS‐PAGE and autoradiography. These studies indicated that no differences in the characteristics of the TSH receptor or of microsomal antigen were observed in the tissue samples 1–3 and 7. Neither protein was detected in tissue specimens 4–6.
DIFFERENTIATION OF AUTOIMMUNE OPHTHALMOPATHY FROM GRAVES’HYPERTHYROIDISM BY ANALYSIS OF GENETIC MARKERS
Authors: KENDALL‐TAYLOR P. , STEPHENSON A. , STRATTON A. , PAPIHA S. S. , PERROS P. , ROBERTS D. F.
Published: March 2008

Graves' hyperthyroidism and dysthyroid eye disease are closely related autoimmune conditions. Whether the eye disease is an integral part of Graves' disease or a separate entity is controversial. To investigate this we have examined the genetic associations of ophthalmopathy and hyperthyroidism, and compared their phenotype and gene frequencies with a control normal population. HLA‐A, B, and DR antigens were typed in 67 patients with dysthyroid eye disease (GO), 60 hyperthyroid patients without significant eye disease (HT) and 500 normal subjects. Patients were also typed for a variety of other genetic markers: blood group systems (10), serum proteins (6) and red cell enzyme systems (10). Increased frequency of B8 and DR3 in Graves' disease was confirmed; B17 occurred less frequently and appears to be protective. HLA antigen frequencies for GO did not differ from HT. The MNS blood group showed a significant association with Graves' disease, the HT patients having a deficit of the s gene compared with controls. The most interesting finding was an increased frequency of blood group P in GO patients compared with either HT or controls. Significant differences were not seen with any of the other HLA antigens, blood groups, protein or enzyme markers considered individually. Multivariate analysis applied first to the HLA and then to the non‐HLA systems indicated clear separation of the two patient groups. Although Graves' eye disease shares the same HLA associations as hyperthyroidism, it differs in the increased frequency of P blood group, suggesting that additional genetic factors may determine which patients with Graves' disease develop ophthalmopathy.
REDUCED FREQUENCY OF LUTEINIZING HORMONE PULSES IN WOMEN WITH WEIGHT LOSS‐RELATED AMENORRHOEA AND MULTIFOLLICULAR OVARIES
Authors: MASON H. D. , SAGLE M. , POLSON D. W. , KIDDY D. , DOBRIANSKY D. , ADAMS J. , FRANKS S.
Published: March 2008

We have studied pulsatile secretion of LH in 10 women with secondary amenorrhoea and multifollicular ovaries (MFO). This group of patients have a history of mild to moderate, or partially recovered weight loss. They have normal basal LH concentrations but evidence of oestrogen deficiency suggesting a hypothalamic abnormality of gonadotrophin regulation. The results of gonadotrophin pulse analysis were compared with those in normal women during the early follicular phase of the cycle. The mean LH concentration during the 8 h study (5.0 ± 0.9 [SD] U/l) was not significantly different from that in normal women (5.7 ± 2.5). There was no difference between the groups in mean LH pulse amplitude (2.1 ± 0.5 in MFO; 2.2 ± 1.3 in normal women). The frequency of LH pulses was, however, significantly lower in women with MFO (2.8 ± 1.6 vs 4–8 ± 1.5, P<0.05). Two women with MFO had LH pulses of normal frequency. One subsequently developed a normal pattern of ovarian follicles. The other showed a sleep‐related rise in LH concentrations during a 24 h profile which was similar to the pattern of gonadotrophin secretion normally observed during late puberty. These results show that women with MFO have a hypothalamic disturbance of gonadotrophin regulation with slowing of LH pulses without a diminution of pulse amplitude.
EFFECTS OF CHANGING GONADOTROPHIN‐RELEASING HORMONE PULSE FREQUENCY ON GONADOTROPHIN SECRETION IN MEN
Authors: SAUDER S. E. , FRAGER M. S. , CASE G. D. , KELCH R. P. , MARSHALL J. C.
Published: March 2008

To investigate the effects of alterations in GnRH pulse frequency on gonadotro‐phin secretion, we administered low dose GnRH pulses (25 ng/kg) at hourly or 2‐hourly frequencies to eight normal men. All subjects received GnRH pulses i.v. every 2 h for 88 h. Following this, exogenous GnRH was discontinued in four normal men (Group A, GnRH withdrawal), and the frequency of GnRH injections was increased to one pulse every hour for 24 h in the other four normal men (Group B, hourly GnRH). Blood samples were obtained every 20 min for LH and FSH and every 12 h for testosterone (T) and oestradiol (E2). Plasma LH increased in all subjects during injection of GnRH pulses every 2h. Withdrawal of GnRH pulses in Group A men was accompanied by a fall in mean LH, reductions in LH pulse amplitude (x̄± SEM: control 6.5±1.0; GnRH withdrawal 4.0 ± 0.5 mlU/ml) and pulse frequency (control 5.5 ± 0.2; GnRH withdrawal 3.5 ± 0.7 pulses/12 h), and an increase in plasma E2 (control 122 ± 15; GnRH withdrawal 340 ± 37 pmol/l). Gonadotrophin responses to GnRH (25 ng/kg) were normal when tested 32 h after GnRH withdrawal. Injection of hourly GnRH pulses in Group B men was accompanied by a time‐dependent change in mean LH, which transiently rose, then fell, and subsequently rose to a plateau during the second 12 h period of hourly GnRH. The final rise in LH was accompanied by an increase in LH frequency to 11.8 ± 0.3 pulses/12 h. These data suggest that: (1) increases in gonadal steroids decrease LH secretion by reducing the amplitude and frequency of endogenous GnRH pulses; and (2) the normal adult male pituitary requires approximately 12 h to initiate a sustained increase in LH secretion in response to a doubling in GnRH pulse frequency.
METABOLIC AND THYROIDAL RESPONSES TO MILD COLD ARE ABNORMAL IN OBESE DIABETIC WOMEN
Authors: LEAN M. E. J. , MURGATROYD P. R. , ROTHNIE I. , REID I. W. , HARVEY R.
Published: March 2008

Mild cold exposure (22°C, with reference to 28°C, thermoneutral) was studied by overnight whole‐body indirect calorimetry in euthyroid women. Basal, sleeping, energy expenditure (EE) was significantly increased (+ 3.8%, P < 0.05) in six normal weight women but reduced (−3.5%, P < 0.05) in five obese type II diabetic women. Mixed responses were found in five women with simple obesity. Biochemical measurements were made on fasting blood samples taken at 0900 h after 12 h exposure to the two temperatures. Serum T4, free T3 and TSH were within the normal reference range in all subjects. Serum T4 did not show any differences between the groups, nor any effect from temperature. There was a significant increase in free T3 (P < 0.05) at 22°C in the control subjects, but no differences in the obese diabetic women. Serum thyroglobulin fell significantly in the diabetic group. Both TSH and free T3 responses to mild cold were significantly different between the groups, but both correlated positively (P<0.05) with the changes in sleeping energy expenditure at 22°C with reference to 28°C. Changes in TSH and free T3 were themselves significantly correlated within individuals (P<0.01). The normal physiological non‐shivering thermogenesis of adult humans on exposure to a cool environment may thus be mediated by a pituitary‐thyroid mechanism. The abnormal response of obese diabetic women was associated with impaired TSH and thyroid hormone responses, and may be a factor contributing to weight gain.
Randomized controlled GH trial: effects on anthropometry, body composition and body proportions in a large group of children with Prader–Willi syndrome
Authors: Festen Dederieke A. M. , De Lind van Wijngaarden Roderick , Van Eekelen Marielle , Otten Barto J. , Wit Jan M. , Duivenvoorden Hugo J. , Hokken‐Koelega Anita C. S.
Published: March 2008

Background  Prader–Willi syndrome (PWS) children have impaired growth, and abnormal body composition. Previous 1‐year controlled studies showed improvement of height and body composition during GH‐treatment.

Objective  To evaluate growth, body composition and body proportions during GH‐treatment in a large group of PWS children.

Design/patients  We performed a randomized controlled GH trial in 91 prepubertal PWS children (42 infants, 49 children, aged 3–14 years). After stratification for age, infants were randomized to GH‐treatment (GH‐group; 1 mg/m2/day; n = 20), or no treatment (control group; n = 22) for 1 year. In the second year all infants were treated with GH. After stratification for BMI, children > 3 years of age were randomized to GH‐treatment (GH‐group; 1 mg/m2/day; n = 27) or no treatment (control group; n = 22) for 2 years. Anthropometric parameters were assessed once in every 3 months. Body composition was measured by Dual Energy X‐ray Absorptiometry.

Results  Median (interquartile range, iqr) height SDS increased during 2 years of GH in infants from –2·3 (–2·8 to –0·7) to –0·4 (–1·1–0·0) and in prepubertal children from –2·0 (–3·1 to –1·7) to –0·6 (–1·1 to –0·1). In non‐GH‐treated children height SDS did not increase. Head circumference completely normalized during 1 and 2 years of GH in infants and children, respectively. Body fat percentage and body proportions improved in GH‐treated children, but did not completely normalize. Lean body mass SDS improved compared to the control group. Serum IGF‐I increased to levels above the normal range in most GH‐treated children.

Conclusions  Our randomized study shows that GH‐treatment in PWS children significantly improves height, BMI, head circumference, body composition and body proportions. PWS children are highly sensitive to GH, suggesting that monitoring of serum IGF‐I is indicated.
Sequential exhaustive extraction of a Mollisol soil, and characterizations of humic components, including humin, by solid and solution state NMR
Authors: Song G. , Novotny E. H. , Simpson A. J. , Clapp C. E. , Hayes M. H. B.
Published: March 2008

A comprehensive sequential extraction procedure was applied to isolate soil organic components using aqueous solvents at different pH values, base plus urea (base‐urea), and finally dimethylsulfoxide (DMSO) plus concentrated H2SO4 (DMSO‐acid) for the humin‐enriched clay separates. The extracts from base‐urea and DMSO‐acid would be regarded as ‘humin’ in the classical definitions. The fractions isolated from aqueous base, base‐urea and DMSO‐acid were characterized by solid and solution state NMR spectroscopy. The base‐urea solvent system isolated ca. 10% (by mass) additional humic substances. The combined base‐urea and DMSO‐acid solvents isolated ca. 93% of total organic carbon from the humin‐enriched fine clay fraction (<2 μm). Characterization of the humic fractions by solid‐state NMR spectroscopy showed that oxidized char materials were concentrated in humic acids isolated at pH 7, and in the base‐urea extract. Lignin‐derived materials were in considerable abundance in the humic acids isolated at pH 12.6. Only very small amounts of char‐derived structures were contained in the fulvic acids and fulvic acids‐like material isolated from the base‐urea solvent. After extraction with base‐urea, the 0.5 m NaOH extract from the humin‐enriched clay was predominantly composed of aliphatic hydrocarbon groups, and with lesser amounts of aromatic carbon (probably including some char material), and carbohydrates and peptides. From the combination of solid and solution‐state NMR spectroscopy, it is clear that the major components of humin materials, from the DMSO‐acid solvent, after the exhaustive extraction sequence, were composed of microbial and plant derived components, mainly long‐chain aliphatic species (including fatty acids/ester, waxes, lipids and cuticular material), carbohydrate, peptides/proteins, lignin derivatives, lipoprotein and peptidoglycan (major structural components in bacteria cell walls). Black carbon or char materials were enriched in humic acids isolated at pH 7 and humic acids‐like material isolated in the base‐urea medium, indicating that urea can liberate char‐derived material hydrogen bonded or trapped within the humin matrix.
Soil air compression in clays during flood irrigation
Authors: Navarro V. , Yustres A. , Candel M. , García B.
Published: March 2008

Soil air is compressed ahead of the wetting front in flood irrigation when the water table is close to the ground surface and the soil is clayey. The general perception is that a two‐dimensional two‐phase flow model should be used to take into account the effects of air compression on infiltration. In this paper, we apply a model of this kind to validate this perception. The results show that the behaviour of the system is controlled by lateral air flow towards the contours of the ponded area. Even in cases where the width of the ponded area is reduced, in the clayey soils analysed, the soil air pressure is 22% greater than the atmospheric pressure, with a water intake rate amounting to only 19% of the values that would have been obtained if air compression (free air escape) had not been considered. Therefore, the suitability of use of a two‐dimensional two‐phase flow model is demonstrated quantitatively.
The Fort Drum Crystal Mine, Florida, USA
Authors: Whicher John
Published: March 2008

The Pliocene and Pleistocene deposits of South Florida contain a spectacularly rich fossil record and chronicle several cycles of marine inundation and freshwater lake formation. The Pinecrest, Tamiami, Caloosahatchee and Bermont formations are famed for the variety and preservation of their molluscan faunas. It is therefore sad that good exposures are ephemeral and where they do exist it is very difficult to gain access. In addition, the large commercial pits that exploit the sediments for landfill and aggregate are rarely pumped dry, the material being extracted by draglines from the flooded pit, thereby rendering it impossible to study the stratigraphy.
Two‐dimensional joint inversion of radiomagnetotelluric and direct current resistivity data
Authors: Candansayar M. Emin , Tezkan Bülent
Published: March 2008

An algorithm for the two‐dimensional (2D) joint inversion of radiomagnetotelluric and direct current resistivity data was developed. This algorithm can be used for the 2D inversion of apparent resistivity data sets collected by multi‐electrode direct current resistivity systems for various classical electrode arrays (Wenner, Schlumberger, dipole‐diplole, pole‐dipole) and radiomagnetotelluric measurements jointly. We use a finite difference technique to solve the Helmoltz and Poisson equations for radiomagnetotelluric and direct current resistivity methods respectively. A regularized inversion with a smoothness constrained stabilizer was employed to invert both data sets. The radiomagnetotelluric method is not particularly sensitive when attempting to resolve near‐surface resistivity blocks because it uses a limited range of frequencies. On the other hand, the direct current resistivity method can resolve these near‐surface blocks with relatively greater accuracy. Initially, individual and joint inversions of synthetic radiomagnetotelluric and direct current resistivity data were compared and we demonstrated that the joint inversion result based on this synthetic data simulates the real model more accurately than the inversion results of each individual method. The developed 2D joint inversion algorithm was also applied on a field data set observed across an active fault located close to the city of Kerpen in Germany. The location and depth of this fault were successfully determined by the 2D joint inversion of the radiomagnetotelluric and direct current resistivity data. This inversion result from the field data further validated the synthetic data inversion results.
Potential distribution of the invasive tree Triadica sebifera (Euphorbiaceae) in the United States: evaluating climex predictions with field trials
Authors: PATTISON ROBERT R. , MACK RICHARD N.
Published: March 2008

Models that project introduced species distributions based on the climates in native and potential introduced ranges can provide valuable insights on the extent of a species' future spread. Yet, the lack of direct field evaluation of these range projections remains a major limitation. We evaluated results from the climex model in conjunction with results from seed and plant field trials in assessing environmental constraints to spread of the invasive tree Triadica sebifera (Chinese tallow tree) in the southeastern USA. climex incorporates key climatic parameters to generate large‐scale projections of potential distributions based on the climate across the species' current distribution. By employing field trials within microhabitats within and beyond the tree's current range, we were able to determine seed and young plants' response to the heterogeneity of the environment at regional scales. Based on projections of the climex model, T. sebifera has the potential to spread 500 km northward beyond its current distribution in the southeastern USA; minimum temperature and limited precipitation are the key climatic constraints in the eastern and western USA, respectively. climex results correlate strongly with seed germination across sites in the southeastern USA. These results do not however correlate with plant growth rates, which were often higher in sites with low projected climatic suitability. Competition and herbivory were not constraints on the growth of T. sebifera in our field trials and were therefore not responsible for the lack of correlation between model results and plant growth rates. If the minimum and maximum temperatures were to rise by 2 °C, the range of T. sebifera could extend northward 700 km beyond its current distribution. While both climex and the field trials indicate that T. sebifera is capable of extensive northward spread in the eastern USA, results of field trials indicate that the patterns of invasion within the region are likely to vary substantially with local site conditions.