bluuebunny/crossref_metadata_2025 huggingface dataset:
Technetium‐99m‐sestamibi subtraction scintigraphy vs. ultrasonography combined with a rapid parathyroid hormone assay in parathyroid aspirates in preoperative localization of parathyroid adenomas and in directing surgical approach
Authors: Barczynski Marcin , Golkowski Filip , Konturek Aleksander , Buziak‐Bereza Monika , Cichon Stanislaw , Hubalewska‐Dydejczyk Alicja , Huszno Bohdan , Szybinski Zbigniew
Published: June 2006

Objective  To determine the sensitivity and positive predictive value (PPV) of subtraction scintigraphy (SS) vs. ultrasonography (US) of the neck combined with rapid intact parathyroid hormone (iPTH) assay in US‐guided fine‐needle parathyroid aspirates in preoperative localization of parathyroid adenomas and in directing surgical approach.

Design  The results of SS for localization of parathyroid adenoma were determined in 121 patients with primary hyperparathyroidism (pHPT) and compared with findings at surgery and with the results of US alone (in patients without nodular goitre) and US in combination with the iPTH assay in US‐guided fine‐needle aspirates (FNAs) of suspicious parathyroid lesions (in patients with concomitant nodular goitre).

Patients  All 121 patients had biochemically documented pHPT; all were referred for first‐time surgery.

Measurements  SS was performed with 99mTc‐sestamibi and 99mTc‐pertechnetate. High‐resolution US of the neck was performed by a single endocrine surgeon and combined with US‐guided FNAs of suspicious parathyroid lesions in all patients with nodular goitre (n = 43).

Results  The sensitivity and PPV of SS were significantly higher in patients without vs. with goitre (89·3% and 95·7%vs. 74·3% and 76·5%, respectively; P < 0·001). The sensitivity and PPV of US were significantly higher in patients without vs. with goitre (96% and 97·3%vs. 67·7% and 71·9%, respectively; P < 0·001). The iPTH assay of US‐guided FNAs of suspicious parathyroid lesions in patients with nodular goitre significantly improved both the sensitivity and PPV of US imaging (90·7% and 100%, respectively), allowing for an accurate choice of surgical approach in 118 (97·5%) of 121 patients. SS was more accurate than US alone in detection of ectopic parathyroid adenomas. However, US alone was characterized by a higher sensitivity in detection of small parathyroid adenomas (< 500 mg) at typical sites (P < 0·01).

Conclusions  Both the sensitivity and PPV of SS and US alone are comparable, with significantly less accurate results obtained in patients with goitre. In cases of equivocal results of US and/or in patients with concomitant goitre, an iPTH assay in US‐guided FNAs of suspicious parathyroid lesions may be used to establish the nature of the mass, distinguish between parathyroid and nonparathyroid tissue (goitre, lymph nodes) and improve the accuracy of US parathyroid imaging, allowing for successful directing of surgical approach in a majority of patients.
Signs and symptoms from ectodermal organs in young Swedish individuals with oligodontia
Authors: BERGENDAL B. , NORDERYD J. , BÅGESUND M. , HOLST A.
Published: June 2006

Summary.  Objectives.  The aim was to assess signs and symptoms from other ectodermal organs in addition to teeth in young individuals with oligodontia and to establish the prevalence of oligodontia.

Sample and methods.  Children born 1981–94 reported by dental teams in the Public Dental Service to have oligodontia were asked to participate in a clinical study. The examinations comprised a structured interview on symptoms from ectodermal organs, and testing of salivary secretion.

Results.  One hundred and sixty‐two individuals met the inclusion criteria, and 123 individuals (75·9%) participated in the clinical study. Half of the individuals had one to four signs or symptoms from ectodermal organs beside oligodontia. The most common sign was low salivary secretion. Twelve individuals (9·6%) with isolated oligodontia reported impaired function of the sweat glands, hair, or nails. The prevalence of oligodontia was 0·090%.

Conclusions.  An early identification of individuals with oligodontia can be made in a majority of cases by checking that all permanent incisors have erupted at the age of 8 years. The validity in asking individuals about normal and abnormal function of ectodermal organs was found to be low. This indicates that there is a strong need to establish routine clinical criteria for dysplasia of ectodermal organs.
Ecosystem alteration modifies the relative strengths of bottom‐up and top‐down forces in a herbivore population
Authors: MOREAU GAÉTAN , EVELEIGH ELDON S. , LUCAROTTI CHRISTOPHER J. , QUIRING DAN T.
Published: June 2006

Ecosystem alterations can affect the abundance, distribution and diversity of plants and animals, and thus potentially change the relative strength of bottom‐up (the plant resource) and top‐down (natural enemies) trophic forces acting on herbivore populations.

The hypothesis that alterations of the forest ecosystem associated with precommercial thinning have contributed to the increased severity of outbreaks ofNeodiprion abietis(Harris), a sawfly defoliator, through the reduction of trophic forces acting onN. abietislarvae, was tested using exclusion techniques.

The relative contributions toN. abietislarval mortality of bottom‐up and top‐down forces both increased with increasing levels of defoliation and were both reduced by thinning. The reduction of bottom‐up and top‐down forces caused a 58% mean increase inN. abietislarval survival in thinned compared with untreated stands, which is less than would be expected by the sum of the effects of thinning on each source of mortality. Evidence indicates that the partly compensatory, partly additive nature of the mortality associated with trophic forces in the system under study is responsible for this discrepancy.

To our knowledge, this is the first study to show the impact of ecosystem alterations on the balance between bottom‐up and top‐down forces acting on an eruptive herbivore population along a gradient of host‐plant defoliation, and how this can lead to increased outbreak severity. It is stressed that accurate estimates of the relative contributions of bottom‐up and top‐down forces to mortality cannot be obtained if the additive or compensatory nature of the mortality associated with these trophic forces is overlooked.
Patterns of growth and body condition in sea otters from the Aleutian archipelago before and after the recent population decline
Authors: LAIDRE K. L. , ESTES J. A. , TINKER M. T. , BODKIN J. , MONSON D. , SCHNEIDER K.
Published: June 2006

Growth models for body mass and length were fitted to data collected from 1842 sea ottersEnhydra lutrisshot or live‐captured throughout south‐west Alaska between 1967 and 2004. Growth curves were constructed for each of two main year groups: 1967–71 when the population was at or near carrying capacity and 1992–97 when the population was in steep decline. Analyses of data collected from animals caught during 2004, when the population density was very low, were precluded by a small sample size and consequently only examined incidentally to the main growth curves.

Growth curves demonstrated a significant increase in body mass and body length at age in the 1990s. Asymptotic values of body mass were 12–18% higher in the 1990s than in the 1960s/70s, and asymptotic values for body length were 10–11% higher between the same periods. Data collected in 2004 suggest a continued increase in body size, with nearly all data points for mass and length falling significantly above the 1990s growth curves.

In addition to larger asymptotic values for mass and length, the rate of growth towards asymptotic values was more rapid in the 1990s than in the 1960s/70s: sea otters reached 95% of asymptotic body mass and body length 1–2 years earlier in the 1990s.

Body condition (as measured by the log mass/log length ratio) was significantly greater in males than in females. There was also an increasing trend from the 1960s/70s through 2004 despite much year‐to‐year variation.

Population age structures differed significantly between the 1960s/70s and the 1990s with the latter distribution skewed toward younger age classes (indicating an altered lxfunction) suggesting almost complete relaxation of age‐dependent mortality patterns (i.e. those typical of food‐limited populations).

This study spanned a period of time over which the population status of sea otters in the Aleutian archipelago declined precipitously from levels at or near equilibrium densities at some islands in the 1960s/70s to < 5% of estimated carrying capacity by the late 1990s. The results of this study indicate an improved overall health of sea otters over the period of decline and suggest that limited nutritional resources were not the cause of the observed reduced population abundance. Our findings are consistent with the hypothesis that the decline was caused by increased killer whale predation.
Lineage origin and expansion of a Neotropical migrant songbird after recent glaciation events
Authors: BOULET MARYLÈNE , GIBBS H. LISLE
Published: June 2006

Birds of the Northern Hemisphere often harbour the genetic signature of postglaciation expansion but analyses identifying the location of refugia and the directionality of expansions are rare. Here we explore the evolutionary history of yellow warbler lineages, focusing on how these lineages recolonized their current range. We genotyped samples from 696 yellow warblers via direct sequencing of a 333‐bp control region I mitochondrial DNA fragment or lineage‐specific genotyping. Phylogenetic analysis revealed two monophyletic clades: a highly migratory group including previously identified eastern and western lineages and a less migratory group including a lineage consisting of tropical residents and a new ‘southern’ lineage localized in southwest United States. We then modelled the expansion of the eastern and western lineages, identified the location of potential refugia and assessed the importance of migration as a historical factor promoting gene flow. The expansion of the eastern lineage proceeded from a main refugia in the eastern United States, with possible contribution of an additional local refugia. In the western lineage, the expansion proceeded from a single refugia possibly located in western United States. Because two lineages overlapped to varying degrees in central North America, we suggest that the Canadian Prairies offered a bridge of riparian habitats where the lineages met after glacier retreat, while the US Central Great Plains acted as a barrier that limited secondary contact. Finally, gene flow was more important along the north–south axis of migration than away from it, suggesting spring migration played a role in the dispersal of lineages.
Premature targeting of cell division proteins to midcell reveals hierarchies of protein interactions involved in divisome assembly
Authors: Goehring Nathan W. , Gonzalez Mark D. , Beckwith Jon
Published: June 2006

In order to divide, the bacterium Escherichia coli must assemble a set of at least 10 essential proteins at the nascent division site. These proteins localize to midcell according to a linear hierarchy, suggesting that cell division proteins are added to the nascent divisome in strict sequence. We previously described a method, ‘premature targeting’, which allows us to target a protein directly to the division site independently of other cell division proteins normally required for its localization at midcell. By systematically applying this method to probe the recruitment of and associations among late cell division proteins, we show that this linear assembly model is likely incorrect. Rather, we find that the assembly of most of the late proteins can occur independently of ‘upstream’ proteins. Further, most late proteins, when prematurely targeted to midcell, can back‐recruit upstream proteins in the reverse of the predicted pathway. Together these observations indicate that the late proteins, with the notable exception of the last protein in the pathway, FtsN, are associated in a hierarchical set of protein complexes. Based on these observations we present a revised model for assembly of the E. coli division apparatus.
Regulation and expression of bba66 encoding an immunogenic infection‐associated lipoprotein in Borrelia burgdorferi
Authors: Clifton Dawn R. , Nolder Christi L. , Hughes Jessica L. , Nowalk Andrew J. , Carroll James A.
Published: June 2006

When Borrelia burgdorferi (Bb) is transmitted from a tick vector to a mammalian host the spirochaete alters gene expression, allowing for adaptation to the new host. We evaluated the regulation of paralogous gene family (pgf) 54 members in response to environmental cues and focused our efforts on determining the molecular mechanisms influencing bba66 expression. By qRT‐PCR, bba65, bba66, bba71 and bba73 displayed regulation similar to ospC under mammalian‐like conditions. Of the pgf 54 members, bba66 demonstrated the greatest and second greatest change in expression in response to pH or temperature shift respectively. Furthermore, Bb‐infected mice and patients with early disseminated Lyme disease produced detectable antibodies to BBA66. A protein(s) active in Bb at pH 7 was able to interact with the bba66 upstream region and was specific as bba64 and ospC promoters were unable to out‐compete for binding. bba66 promoter mapping revealed putative σ70 and σS consensus sequences, enabling us to narrow the protein binding site to a region within an imperfect inverted repeat upstream of the −35 region. Moreover, BBA66 production is associated with an infectious phenotype, and loss of either σN or σS resulted in loss of BBA66. Promoter‐GFP fusion analysis indicated that the σ70 and/or σS consensus sequences alone were not sufficient to initiate transcription and a portion of the upstream inverted repeat was required. These results suggest a primary role for BBA66 in Bb transmission and infection.
Type IV pili function upstream of the Dif chemotaxis pathway in Myxococcus xanthus EPS regulation
Authors: Black Wesley P. , Xu Qian , Yang Zhaomin
Published: June 2006

The developmental bacterium Myxococcus xanthus utilizes gliding motility to aggregate during the formation of multicellular fruiting bodies. The social (S) component of M. xanthus gliding motility requires at least two extracellular surface structures, type IV pili (Tfp) and the fibril polysaccharide or exopolysaccharide (EPS). Retraction of Tfp is proposed to power S motility and EPS from neighbouring cells is suggested to provide an anchor and trigger for Tfp retraction. The production of EPS in M. xanthus is regulated in part by the Dif chemosensory pathway; however, the input signal for the Dif pathway in EPS regulation remains to be uncovered. Using a genetic approach combined with quantitative and qualitative analysis, we demonstrate here that Tfp function upstream of the Dif proteins in regulating EPS production. The requirement of Tfp for the production of EPS was verified using various classes of Tfp mutants. Construction and examination of double and triple mutants indicated that mutations in dif are epistatic to those in pil. Furthermore, extracellular complementation between various Tfp and dif mutants suggests that Tfp, instead of being signals, may constitute the sensor or part of the sensor responsible for mediating signal input into the Dif pathway. We propose that S motility involves a regulatory loop in which EPS triggers Tfp retraction and Tfp provide proximity signals to the Dif pathway to modulate EPS production.
The order of the ring: assembly of Escherichia coli cell division components
Authors: Vicente Miguel , Rico Ana Isabel
Published: June 2006

Topological cues appear to override temporal events in the assembly of the Escherichia coli cell division ring. When a procedure that allows the recruitment of ring components based on their topological properties is used, a concerted mode of assembly of several components of the divisome, rather than a strict linear mode, is revealed. Three multimolecular complexes, the proto‐ring, the periplasmic connector and the peptidoglycan factory, show some degree of concertation for their assembly. In addition, back‐recruitment of all late proteins except FtsN into the division ring occurs even in the absence of proteins incorporated at earlier stages, i.e. FtsA or FtsQ.
Geochemical arguments for identifying second‐order sea‐level changes in hemipelagic carbonate ramp deposits
Authors: Rosales Idoia , Quesada Santiago , Robles Sergio
Published: June 2006

Second‐order transgressive–regressive (T–R) cycles, previously recognized using sedimentological criteria in Lower Jurassic hemipelagic deposits from northern Spain, are distinguishable based upon bulk‐rock organic geochemistry [total organic carbon (TOC) and hydrogen index (HI)] and the stable carbon isotope compositions from belemnite rostra. There is a coincidence between regressions and decreasing δ13Cbel, TOC and HI values, and between transgressions and increasing δ13Cbel, TOC and HI values. The δ18O and Mg/Ca records from the belemnite rostra are not always in phase with the T–R cycles. The δ18Obel record reveals, however, a prominent excursion towards higher values within the spinatum Zone that correlates, according to our results, with a regression and with negative shifts in Mg/Ca, δ13Cbel and TOC. On the other hand, an excursion in the δ18Obel towards lower values in the serpentinus Zone also correlates with a peak transgression and with positive shifts in Mg/Ca, δ13Cbel and TOC. These two excursions have been identified in other European regions as geochemical perturbations of the same characteristics. This suggests a link between second‐order relative sea‐level changes and variations in seawater geochemistry that may reflect local and regional palaeoceanographic perturbations in sea‐water temperature, salinity and water circulation during the Early Jurassic.

Terra Nova, 18, 233–240, 2006
The lba1 mutation of UPF1 RNA helicase involved in nonsense‐mediated mRNA decay causes pleiotropic phenotypic changes and altered sugar signalling in Arabidopsis
Authors: Yoine Masato , Ohto Masa‐aki , Onai Kiyoshi , Mita Satoru , Nakamura Kenzo
Published: June 2006

The low‐beta‐amylase1 (lba1) mutant of Arabidopsis thaliana has reduced sugar‐induced expression of Atβ‐Amy and shows pleiotropic phenotypes such as early flowering; short day‐sensitive growth; and seed germination that is hypersensitive to glucose and abscisic acid and resistant to mannose. lba1 was a missense mutation of UPF1 RNA helicase involved in nonsense‐mediated mRNA decay (NMD), which eliminates mRNAs with premature termination codons (PTCs), and replaces highly conserved Gly851 of UPF1 with Glu. Expression of the wild‐type UPF1 in lba1 rescued not only the reduced sugar‐inducible gene expression, but also early flowering and altered seed‐germination phenotypes. Sugar‐inducible mRNAs were over‐represented among transcripts decreased in sucrose‐treated lba1 compared with Col plants, suggesting that UPF1 is involved in the expression of a subset of sugar‐inducible genes. On the other hand, transcripts increased in lba1, which are likely to contain direct targets of NMD, included mRNAs for many transcription factors and metabolic enzymes that play diverse functions. Among these, the level of an alternatively spliced transcript of AtTFIIIA containing PTC was 17‐fold higher in lba1 compared with Col plants, and it was reduced to the level in Col by expressing the wild‐type UPF1. The lba1 mutant provides a good tool for studying NMD in plants.
Adaptive evolution of the Bordetella autotransporter pertactin
Authors: Diavatopoulos D. A. , Hijnen M. , Mooi F. R.
Published: June 2006

The virulence factor pertactin is expressed by the closely related pathogens Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica. Pertactin is an autotransporter involved in adherence of Bordetella species to the lung epithelium of mammalian hosts, and it is an important component of most current acellular pertussis vaccines. These three species produce immunologically distinct pertactin molecules, resulting in a lack of cross-protection against B. parapertussis and probably also against B. bronchiseptica. Variation in pertactin is not only inter-specific, but also occurs between isolates from the same species. Knowledge about codons that are under positive selection could facilitate the development of more broadly protective vaccines. Using different nucleotide substitution models, pertactin genes from B. bronchiseptica, B. parapertussis and B. pertussis were compared, and positively selected codons were identified using an empirical Bayesian approach. This approach yielded 15 codons predicted to be under diversifying selection pressure. These results were interpreted in an immunological context and may help in improving future pertussis vaccines.
Potential causes of weight gain in type 1 diabetes mellitus
Authors: Jacob A. N. , Salinas K. , Adams‐Huet B. , Raskin P.
Published: June 2006

Aim:  To investigate the potential causes of weight gain with insulin therapy and improved diabetic control in type 1 diabetes mellitus.

Methods:  This was an open‐label prospective study of insulin therapy of 6 months duration in an academic medical centre. Twenty‐one subjects with type 1 diabetes were enrolled. The goal was to achieve an haemoglobin A1c (HbA1c) in the range of individuals without diabetes (<5.6%). At baseline, 3 and 6 months, weight, resting energy expenditure, appetite assessment, food intake, activity level, HbA1c and 24‐h glycosuria and urea nitrogen were measured. Plasma leptin, ghrelin and adiponectin levels and body fat were measured at baseline and 6 months.

Results:  At baseline, average weight was 73.7 ± 17.4 kg and HbA1c was 10.0 ± 2.2%. Weight increased by 2.15 kg (2.69% of baseline) by 6 months whereas the HbA1c dropped by 1.71% (16.3%) to 7.9%. Energy intake differences between 3 and 6 months had a negative correlation with weight gain, but the changes in glycosuria, appetite scores and the frequency of hypoglycaemia did not correlate with weight gain. Glycaemic control did not correlate with weight change but tended to correlate with fat mass increase (p = 0.064; r = −0.51). An increase in the activity levels between 3 and 6 months correlated with decreasing fat mass (p = 0.037; r = −0.74). The changes in the appetite scores had a negative correlation with fat mass gain (p = 0.035; r = −0.61). The changes in lean body mass correlated with protein and total energy intake (p = 0.007, r = 0.85 and p = 0.003, r = 0.73 respectively). The changes in leptin levels correlated with weight gain.

Conclusions:  The lipogenic effect of insulin with subsequent increase in fat mass may be the primary cause of this weight gain that can be attenuated by the increases in the activity levels. The negative correlation of energy intake and appetite scores with fat mass gain suggests that they do not play a significant role in fat mass gain whereas energy intake did correlate with lean body mass gain.
Acute regulation of plasma leptin by isoprenaline in lean and obese fasted subjects
Authors: Baynes K. C. R. , Nicholas M. D. , Shojaee‐Moradie F. , Umpleby A. M. , Giannoulis M. G.
Published: June 2006

Aim:  In human obesity, there is some evidence for impaired adrenergic sensitivity with respect to catecholamine‐induced lipolysis. The β‐adrenoceptor agonist isoprenaline has been shown to suppress plasma leptin levels in lean humans in vivo. We hypothesized that a reduced adrenergic sensitivity in obese humans would result in impaired suppression of leptin secretion.

Methods:  Eight obese [Ob, body mass index (BMI) = 33.3 kg/m2] and seven lean (Ln, BMI = 21.8 kg/m2) men were studied after an overnight fast. Intravenous isoprenaline infusion was initiated at a rate of 8 ng/kg/min, titrated up to 24 ng/kg/min over 30 min and continued at this rate for a further 120 min with continuous electrocardiogram monitoring.

Results:  Baseline fasting plasma leptin was higher in obese compared with lean subjects (Ob 12.2 ± 1.8, Ln 2.6 ± 0.6 ng/ml, p < 0.05 unpaired t‐test). Baseline fasting glycerol as a measure of lipolysis was similar in both groups (Ob 62.9 ± 7.6, Ln 42.4 ± 8.9 µmol/l) and increased from baseline to 150 min by equivalent amounts (Ob +66.9%, Ln +81.2%, p = NS). Plasma leptin decreased from baseline to 150 min with similar relative changes in both groups (Ob −29.2%, Ln −27.8%).

Conclusions:  Obese subjects show a similar lipolytic and leptin response to acute isoprenaline infusion compared with lean subjects. Impaired β‐adrenergic‐induced inhibition of leptin secretion does not appear to contribute to hyperleptinaemia in obese human subjects.
A metabolomic study of substantial equivalence of field‐grown genetically modified wheat
Authors: Baker John M. , Hawkins Nathaniel D. , Ward Jane L. , Lovegrove Alison , Napier Johnathan A. , Shewry Peter R. , Beale Michael H.
Published: June 2006

The ‘substantial equivalence’ of three transgenic wheats expressing additional high‐molecular‐weight subunit genes and the corresponding parental lines (two lines plus a null transformant) was examined using metabolite profiling of samples grown in replicate field trials on two UK sites (Rothamsted, Hertfordshire and Long Ashton, near Bristol) for 3 years. Multivariate comparison of the proton nuclear magnetic resonance spectra of polar metabolites extracted with deuterated methanol–water showed a stronger influence of site and year than of genotype. Nevertheless, some separation between the transgenic and parental lines was observed, notably between the transgenic line B73‐6‐1 (which had the highest level of transgene expression) and its parental line L88‐6. Comparison of the spectra showed that this separation resulted from increased levels of maltose and/or sucrose in this transgenic line, and that differences in free amino acids were also apparent. More detailed studies of the amino acid composition of material grown in 2000 were carried out using gas chromatography‐mass spectrometry. The most noticeable difference was that the samples grown at Rothamsted consistently contained larger amounts of acidic amino acids (glutamic, aspartic) and their amides (glutamine, asparagine). In addition, the related lines, L88‐6 and B73‐6‐1, both contained larger amounts of proline and γ‐aminobutyric acid when grown at Long Ashton than at Rothamsted. The results clearly demonstrate that the environment affects the metabolome and that any differences between the control and transgenic lines are generally within the same range as the differences observed between the control lines grown on different sites and in different years.
Neuropsychological function in a group of patients 25 years after sustaining minor head injuries as children and adolescents
Authors: HESSEN ERIK , NESTVOLD KNUT , SUNDET KJETIL
Published: June 2006

Previous studies suggest that neuropsychological impairment following mild to moderate pediatric head injury may become persistent and interrupt the normal course of intellectual development. In this study 45 subjects were assessed with a standardized neuropsychological test battery 25 years after sustaining mild to moderate head injury as children. Although the group scores in the normal range, significant relations between head injury severity and current neuropsychological function were found. The most important predictor of poor outcome was length of PTA at injury, EEG pathology, and loss of consciousness at injury. No significant influence of pre‐ and post‐injury risk factors on current neuropsychological function was evident. The findings support the view that complicated mild and moderate paediatric head injury may heighten the risk of developing subtle neuropsychological problems later in life.
TECHNOLOGICAL CHANGE, INEQUALITY AND WORK SHARING
Authors: Moutos Thomas
Published: June 2006

The effects of technological change on wage inequality are usually studied under the assumption of exogenous supplies of skilled and unskilled workers. Moreover, in these studies there is no distinction between the stock (number of workers) and the flow (hours of work) dimension of labour services. In the present paper, we construct a model in which hours of work and technological change affect both the (relative) demand and supply of unskilled workers. The labour supply of unskilled workers (numbers of persons) is derived from a model of household labour supply in which households differ regarding the disutility suffered when both household members work. Combining together the (relative) supply and demand parts of the model we are able to establish technological change (either biased or neutral) as a plausible explanation of recent trends in wage inequality.
BANK INTEREST MARGINS AND BUSINESS START‐UP COLLATERAL: TESTING FOR CONVEXITY
Authors: Burke Andrew , Hanley Aoife
Published: June 2006

The paper investigates the relationship between bank interest rate margins and collateral for loans issued to new ventures. The analysis finds a convex U‐shaped relationship. The results indicate that while provision of collateral initially reduces bank exposure to risk (through security, more optimal levels of capital and lower moral hazard among entrepreneurs) that beyond a point, the positive risk‐wealth association gives rise to greater risk taking propensity among entrepreneurs and ultimately higher interest rates. This indicates that a lender's pricing policy may even somewhat help to level the competitive playing field between ventures launched by higher and moderately wealthy entrepreneurs.
COMPETITION, PARALLEL IMPORTS AND COST‐REDUCING INNOVATION
Authors: Li Changying
Published: June 2006

Incorporating parallel imports (PI), we develop a two‐country two‐firm model which relates to the incentives for cost‐reducing innovation. We show that PI may facilitate or inhibit the manufacturers' incentives to innovate. In particular, PI could encourage both firms' innovations. The difference between the manufacturer's profits under successful innovation and failed innovation is either a U‐shaped curve or an inverted U‐shaped curve in terms of the cost of engaging in PI. As these differences reflect the manufacturers' incentive to innovate, the variations in R&D investment depend on transportation cost, and firms' marginal costs before and after successful innovations.
OPTIMUM‐WELFARE AND MAXIMUM‐REVENUE TARIFFS UNDER BERTRAND DUOPOLY
Authors: Clarke Roger , Collie David R.
Published: June 2006

This article derives the maximum‐revenue tariff and the optimum‐welfare tariff under Bertrand duopoly with differentiated products. It is shown that both tariffs are lower under Bertrand duopoly than under Cournot duopoly. Also, the optimum‐welfare tariff may exceed the maximum‐revenue tariff under both Bertrand duopoly and Cournot duopoly. This result is more likely the lower the costs of the home firm relative to the costs of the foreign firm, and the greater the degree of product substitutability. Also, it is shown that the optimum‐welfare tariff is less likely to exceed the maximum‐revenue tariff under Bertrand duopoly than under Cournot duopoly.
Institutional Arrangements and the Dynamics of Agenda Formation in the U.S. Supreme Court and Courts of Appeals
Authors: HURWITZ MARK S.
Published: June 2006

The manner in which agenda change occurs demonstrates how institutional arrangements influence agenda priorities in the Supreme Court and Courts of Appeals. A neo‐institutional theoretic perspective is employed to examine the dynamics of agenda formation in these courts. The article finds that the Supreme Court's agenda choices influence the decisions of litigants, interest groups, and lawyers to appeal certain cases to the Courts of Appeals. While the Supreme Court's agenda primarily is influenced by internal factors, it is constrained by agenda changes in the appeals courts. Critically, it is shown that these federal appellate courts exist within an endogenous system with respect to agenda formation, as both courts respond to agenda changes made in the other over time.
Are Regulators Responsive?
Authors: NIELSEN VIBEKE LEHMANN
Published: June 2006

For decades there has been a trend in regulatory studies to advocate a responsive, tit‐for‐tat, regulatory strategy. However, most of the prominent arguments for this strategy are theoretical and few have tested its effectiveness. Even less tested has been whether or not regulatory inspectors manage to react responsively to the “conduct” of regulatees. By distinguishing between five different kinds of responsiveness, the present article tests these different kinds of responsiveness in four different regulatory areas, using data about more than 2,500 legal breaches. The empirical analyses show that regulatory inspectors manage to act responsively, but only to a small degree and not necessarily in the way that the theories of responsive and tit‐for‐tat regulation recommend. Furthermore, the analyses show large differences between the four regulatory areas suggesting that future studies should focus on the role of formal and informal institutional settings in creating responsiveness. If we want to design regulatory agencies that are able to regulate responsively we need to know what kind of institutional settings promote responsiveness.
PYRRHIC VICTORY? THE UNINTENDED CONSEQUENCE OF THE PENSIONS ACT 2004
Authors: Byrne Alistair , Harrison Debbie , Rhodes Bill , Blake David
Published: June 2006

The UK's 2004 Pensions Act is a far‐reaching piece of legislation, with significant implications for the occupational pensions marketplace. The Act is intended to improve the governance of pension schemes and increase the security of the members’ accrued benefits. However, our research suggests that it will have serious and adverse unintended consequences. The most significant of these will be to undermine occupational pension provision by placing an increased burden on sponsoring employers, whose involvement in pension provision is on a voluntary basis.
Analysis of strain‐induced ground‐water fluctuations at Devils Hole, Nevada
Authors: CUTILLO P. A. , GE S.
Published: June 2006

The pool in Devils Hole is a sensitive indicator of crustal strain and fluctuates in response to changes in atmospheric pressure, earth tides, earthquakes, large‐scale tectonic activity and ground‐water development. Short‐term and cyclic water‐level fluctuations caused by atmospheric pressure and earth tides were found to be on the order of millimeters to centimeters. The 1992 Landers/Little Skull Mountain earthquake sequence and the 1999 Hector Mine earthquake induced water‐level offsets of greater than −12 and −3.6 cm, respectively. The results of a dislocation model used to compute volumetric strain for each earthquake indicates that the coseismic water‐level offsets are consistent in magnitude and sense with poroelastic responses to earthquake‐induced strain. Theoretical postseismic fluid‐flow modeling indicates that the diffusivity of the system is on the order of 0.03 m2 sec−1, and identified areas of anomalous water‐level fluctuations. Interpretation of model results suggests that while the persistent post‐Landers rise in water‐level can be attributed to deformation‐induced channeling of fluid to the Devils Hole fault zone, the cause of the pre‐Hector Mine water‐level rise may be related to postseismic excess fluid pressures or preseismic strain accumulation.
Physiological correlates of habitat association in East African sunbirds (Nectariniidae)
Authors: Seavy N. E.
Published: June 2006

East African sunbirds (Nectariniidae) vary in the degree to which they use open habitats and forest habitats. Species that use open habitats may experience more extreme temperatures and greater exposure to solar radiation than those in forest habitats. Basal rates of metabolism, body temperature and thermal conductance were compared for open habitat‐ and forest‐associated sunbirds from Kibale National Park, Uganda. Variation in basal rate of metabolism was associated with body mass, but there was no difference between forest and open habitat species. Variation in body temperature was not associated with body mass or habitat. Variation in thermal conductance was associated with body mass and habitat; open habitat species were characterized by significantly lower thermal conductances than forest species. Because reduced thermal conductance may decrease energy expenditure at low ambient temperatures and reduce exogenous heat gain at high ambient temperatures, this difference may optimize energy expenditure when temperatures are highly variable. This suggests a mechanism by which physiological characteristics may influence energetic consequences of habitat selection.
Microsatellite loci for Cherrie's tanager (Ramphocelus costaricensis)
Authors: KRUEGER TERRY R. , WILLIAMS DEAN A.
Published: June 2006

Cherrie's tanager (Ramphocelus costaricensis) is a common woodland bird of the Pacific lowlands of Costa Rica. Males and females have sexually dimorphic plumage and are socially monogamous. As part of a study of sexual selection in this species, we characterized six species‐specific polymorphic microsatellite loci and one cross‐species locus that works well in Cherrie's tanager to ascertain parentage.
Nine polymorphic microsatellite markers in Centaurea stoebe L. [subspecies C. s. stoebe and C. s. micranthos (S. G. Gmelin ex Gugler) Hayek] and C. diffusa Lam. (Asteraceae)
Authors: MARRS ROBIN A. , HUFBAUER RUTH A. , BOGDANOWICZ STEVEN M. , SFORZA RENÉ
Published: June 2006

Centaurea stoebe (subspecies C. s. stoebe and C. s. micranthos[S. G. Gmelin ex Gugler) Hayek] and Centaurea diffusa are Eurasian plant species that have invaded much of North America. We isolated seven microsatellite loci from C. stoebe and two loci from C. diffusa. All loci described here amplify in both species and have between six and 25 alleles each. These markers will be useful in examining population structure and addressing questions regarding these invasions.
Gauging the impact of natural hazards: the pattern and cost of emergency response during flood events
Authors: Penning‐Rowsell Edmund , Wilson Theresa
Published: June 2006

Flood risk management policy in the UK is shifting away from simplistic flood defence towards ‘living with floods’ and ‘making space for water’, thereby accepting that significant flood damage and disruption will continue into the future. This highlights the need for efficient emergency response to flood events, as the first step towards recovery, yet we know very little about the resources and costs that this involves. This paper evaluates the severe flooding in the UK in autumn 2000, and shows that these costs are widely distributed, both geographically and institutionally. Geographically, they broadly match the incidence of property flooding, but they are much larger than we had hitherto appreciated, at approximately 15 per cent of total economic flood losses. The implication is that we should take this topic more seriously in the future than in the past, not see emergency response to floods and other disasters as a low‐cost or even a cost‐free option, and ensure that this effort is as effective as possible in facilitating post‐event recovery.
Cold shoulders and napkins handed: gestures of responsibility
Authors: Laurier Eric , Philo Chris
Published: June 2006

Cafes are places in the city in which we have come to expect conviviality between the unacquainted. Goffman is perhaps the most famous analyst of relations between strangers in public space, yet his depiction of society's members points towards a misanthropic form of life. Drawing on video footage shot during ethnographic research, this paper analyses gestures made between strangers in cafés and how they produce cafés as cold, receptive or accommodating places. It considers how we might move on from Goffman's work to an understanding of urban life that includes the possibility of more than the impression of conviviality.
Mental health, the arts and belongings
Authors: Parr Hester
Published: June 2006

This paper explores how and whether people with severe and enduring mental health problems experience belonging through their participation in a range of contemporary artistic practices and spaces. The paper draws on qualitative evidence from in‐depth interviews with artists in two Scottish community arts‐for‐mental‐health projects in order to show how such spaces engender geographies of creative recovery, social connectedness and cultural inclusivity. Set against a history of insane ‘outsider art’ and art therapy, ‘insider’ and ‘outsider’ positions in relation to the supposedly inclusive cultural city are critically examined. Experiences of artistic belongings are shown as ones constituted by ambiguous and contingent social processes that only partially disrupt ascriptions of difference.
Soft capitalism and a hard industry: virtualism, the ‘transition industry’ and the restructuring of the Ukrainian coal industry
Authors: Swain Adam
Published: June 2006

This paper examines the geographical transfer of economic knowledge and practices from centres of neoliberalism in North America and Western Europe to post‐soviet Ukraine. The paper argues that a ‘transition industry’ emerged in the wake of the disintegration of the soviet system whose purpose was to realize economic transition in central and eastern Europe. The paper discusses the emergence of a community of academic and professional economists affiliated to international financial institutions and academic and professional economic research organizations in Kyiv engaged in promoting the Washington consensus. This community identified the coal industry, located in the Ukrainian Donbas, as a barrier to structural economic reform and the political re‐alignment of the country. The paper then examines the way the World Bank unsuccessfully attempted to force the coal industry to conform to its own policy prescriptions. The example points to the articulation not only of extra‐local and internal processes of neoliberalization, but also with indigenous informal marketization. In this instance the World Bank's vision failed to materialize because state power could not be allied to its neoliberal project.
Who's Who in Conservation Biology—an Authorship Analysis
Authors: HARRISON AUTUMN‐LYNN
Published: June 2006

Abstract:  As the flagship journal of the field, Conservation Biology represents a multidisciplinary, global constituency of conservation professionals—a constituency composed of more than 5200 authors representing 1500 organizations and 89 countries. Using bibliometric records of research published in Conservation Biology, I evaluated trends in authorship of research papers from 1987 to 2005. Authorship diversified and became increasingly collaborative over time. North Americans now compose one‐half of primary authorship, down from 75% in the 1990s, and European primary authors contribute a quarter of the journal's contributed research. Forty‐five countries were represented in volume 19 of the journal. The top three most‐cited authors are Australian. The percentage of single‐authored papers declined from 57% in 1987 to 18% in 2005. Collectively, academic institutions contribute the most research to Conservation Biology, although a government agency, the U.S. Department of Agriculture Forest Service, was the single most‐productive organization. The maturing of conservation biology as a discipline, the complex geographic and multidisciplinary nature of conservation questions, and the increased ease of communication in a technologically connected world contribute to the increasingly diverse and collaborative Conservation Biology authorship.
Demography, Hunting Ecology, and Pathogen Exposure of Domestic Dogs in the Isoso of Bolivia
Authors: FIORELLO CHRISTINE V. , NOSS ANDREW J. , DEEM SHARON L.
Published: June 2006

Abstract:  Disease is increasingly recognized as a threat to the conservation of wildlife, and in many cases the source of disease outbreaks in wild carnivores is the domestic dog. For disease to spill over from a domestic to a wild population, three conditions must be satisfied: susceptibility of the wild species, presence of the disease agent in the domestic population, and contact between the two populations of interest. We investigated the potential for disease spillover from the domestic dog population to the wild carnivore population in the Isoso of Bolivia, an area of tropical dry forest contiguous with a national park. Using questionnaires and discussions with residents, we gathered data on the demography of dogs in the Isoso, including adult and neonatal mortality, litter size, and hunting frequency. We analyzed a large data set containing self‐recorded information on hunting in various communities of the Isoso to determine the extent of dog participation in hunting and the duration of hunting trips. Finally, we took blood samples from dogs in the Isoso for a serosurvey of common canine pathogens. More than 95% of dogs had positive titers to canine distemper virus and canine parvovirus. There was also a high seroprevalence in dogs for other pathogens, a high population turnover of dogs (which may allow diseases to be maintained endemically), and frequent opportunities for contact between domestic and wild carnivores. Based on our results and the susceptibility of wild species previously reported in the literature, domestic dogs represent a disease risk for wildlife in the Bolivian Isoso.
Albite vein formation during exhumation of high‐pressure terranes: a case study from alpine Corsica
Authors: MILLER J. A. , CARTWRIGHT I.
Published: June 2006

The formation of late‐stage veins can yield valuable information about the movement and composition of fluids during uplift and exhumation of high‐pressure terranes. Albite veins are especially suited to this purpose because they are ubiquitously associated with the greenschist facies overprint in high‐pressure rocks. Albite veins in retrogressed metabasic rocks from high‐pressure ophiolitic units of Alpine Corsica (France) are nearly monomineralic, and have distinct alteration haloes composed of actinolite + epidote + chlorite + albite. Estimated P–T conditions of albite vein formation are 478 ± 31 °C and 0.37 ± 0.14 GPa. The P–T estimates and petrographic constraints indicate that the albite veins formed after the regional greenschist facies retrogression, in response to continued decompression and exhumation of the terrane. Stable isotope geochemistry of the albite veins, their associated alteration haloes and unaltered hostrocks indicates that the vein‐forming fluid was derived from the ophiolite units and probably from the metabasalts within each ophiolite slice. That the vein‐forming fluid was locally derived means that a viable source of fluid to form the veins was retained in the rocks during high‐pressure metamorphism, indicating that the rocks did not completely dehydrate. This conclusion is supported by the observation of abundant lawsonite at the highest metamorphic grades. Fluids were liberated during retrogression via decompression dehydration reactions such as those that break down hydrous high‐pressure minerals like lawsonite. Albite precipitation into veins is sensitive to the solubility and speciation of Al, which is more pressure sensitive than other factors which might influence albite vein formation such as silica saturation or Na:K fluid ratios. Hydraulic fracturing in response to fluid generation during decompression was probably the main mechanism of vein formation. The associated pressure decrease with fracturing and fluid decompression may also have been sufficient to change the solubility of Al and drive albite precipitation in fracture systems.