bluuebunny/crossref_metadata_2025 huggingface dataset:
The measurement of complexity in production and other commercial systems
Authors: Frizelle G , Suhov Y
Published: May 2008

The paper gives a review of three case studies of complexity of production systems in manufacturing and commercial industry and develops mathematical methods stemming from these studies. We use as measures of complexity various (long term) entropy rates that naturally emerge in the analysis of systems under consideration; in our case, the main focus is on (physical or virtual) queues and related phenomena. Consequently, a system is considered ‘more complex’ when its entropy rates are higher. The same principle is applied when different subsystems of a given system are compared with each other, identifying a ‘bottleneck’. The numerical values for entropy rates are determined in the course of observation and recording, subject to some simplifying assumptions. To enable us to make effective comparisons, we introduce various classifications of queue-related conditions in systems under investigation. We also discuss a number of practical issues that emerge here, including noise and data loss.
Uniqueness of fast travelling fronts in reaction–diffusion equations with delay
Authors: Aguerrea Maitere , Trofimchuk Sergei , Valenzuela Gabriel
Published: May 2008

We consider positive travelling fronts,
u
(
t
, 
x
)=
ϕ
(
ν
.
x
+
ct
),
ϕ
(−∞)=0,
ϕ
(∞)=
κ
, of the equation
u

t

(
t
, 
x
)=Δ
u
(
t
, 
x
)−
u
(
t
, 
x
)+
g
(
u
(
t
−
h
, 
x
)),
x
∈

m

. This equation is assumed to have exactly two non-negative equilibria:
u
1
≡0 and
u
2
≡
κ
>0, but the birth function
g
∈
C
2
(

, 

) may be non-monotone on [0,
κ
]. We are therefore interested in the so-called monostable case of the time-delayed reaction–diffusion equation. Our main result shows that for every fixed and sufficiently large velocity
c
, the positive travelling front
ϕ
(
ν
.
x
+
ct
) is unique (modulo translations). Note that
ϕ
may be non-monotone. To prove uniqueness, we introduce a small parameter
ϵ
=1/
c
and realize a Lyapunov–Schmidt reduction in a scale of Banach spaces.
Bloch waves in periodic multi-layered acoustic waveguides
Authors: Adams Samuel D.M , Craster Richard V , Guenneau Sebastien
Published: May 2008

The band spectrum and associated Floquet–Bloch eigensolutions, arising in acoustic and electromagnetic waveguides, which have periodic structure along the guide while remaining of finite width, are found. Homogeneous Dirichlet or Neumann conditions along the guide walls, or an alternation of them, are taken. Importantly, in some cases, a total stop band at zero frequency is identified providing space for low-frequency localized modes; geometric defects in the structured waveguide also create these modes. Numerical and asymptotic techniques identify dispersion curves and trapped modes. Some cases demonstrate maxima and minima of the spectral edges within the Brillouin zone and also allow for ultraslow light or sound. Imaging applications using anomalous dispersion to generate subwavelength resolution are possible and are demonstrated.
A gene duplication affecting expression of the ovine ASIP gene is responsible for white and black sheep
Authors: Norris Belinda J. , Whan Vicki A.
Published: May 2008

Agouti signaling protein (ASIP) functions to regulate pigmentation in mice, while its role in many other animals and in humans has not been fully determined. In this study, we identify a 190-kb tandem duplication encompassing the ovine ASIP and AHCY coding regions and the ITCH promoter region as the genetic cause of white coat color of dominant white/tan (AWt) agouti sheep. The duplication 5′ breakpoint is located upstream of the ASIP coding sequence. Ubiquitous expression of a second copy of the ASIP coding sequence regulated by a duplicated copy of the nearby ITCH promoter causes the white sheep phenotype. A single copy ASIP gene with a silenced ASIP promoter occurs in recessive black sheep. In contrast, a single copy functional wild-type (A+) ASIP is responsible for the ancient Barbary sheep coat color phenotype. The gene duplication was facilitated by homologous recombination between two non-LTR SINE sequences flanking the duplicated segment. This is the first sheep trait attributable to gene duplication and shows nonallelic homologous recombination and gene conversion events at the ovine ASIP locus could have an important role in the evolution of sheep pigmentation.
Hydrogen exchange of monomeric α‐synuclein shows unfolded structure persists at physiological temperature and is independent of molecular crowding in Escherichia coli
Authors: Croke Robyn L. , Sallum Christine O. , Watson Emma , Watt Eric D. , Alexandrescu Andrei T.
Published: May 2008

Amide proton NMR signals from the N‐terminal domain of monomeric α‐synuclein (αS) are lost when the sample temperature is raised from 10°C to 35°C at pH 7.4. Although the temperature‐induced effects have been attributed to conformational exchange caused by an increase in α‐helix structure, we show that the loss of signals is due to fast amide proton exchange. At low ionic strength, hydrogen exchange rates are faster for the N‐terminal segment of αS than for the acidic C‐terminal domain. When the salt concentration is raised to 300 mM, exchange rates increase throughout the protein and become similar for the N‐ and C‐terminal domains. This indicates that the enhanced protection of amide protons from the C‐terminal domain at low salt is electrostatic in nature. Cα chemical shift data point to <10% residual α‐helix structure at 10°C and 35°C. Conformational exchange contributions to R2 are negligible at both temperatures. In contrast to the situation in vitro, the majority of amide protons are observed at 37°C in 1H‐15N HSQC spectra of αS encapsulated within living Escherichia coli cells. Our finding that temperature effects on αS NMR spectra can be explained by hydrogen exchange obviates the need to invoke special cellular factors. The retention of signals is likely due to slowed hydrogen exchange caused by the lowered intracellular pH of high‐density E. coli cultures. Taken together, our results emphasize that αS remains predominantly unfolded at physiological temperature and pH—an important conclusion for mechanistic models of the association of αS with membranes and fibrils.
Computational study of the putative active form of protein Z (PZa): Sequence design and structural modeling
Authors: Chandrasekaran Vasu , Lee Chang Jun , Duke Robert E. , Perera Lalith , Pedersen Lee G.
Published: May 2008

Although protein Z (PZ) has a domain arrangement similar to the essential coagulation proteins FVII, FIX, FX, and protein C, its serine protease (SP)‐like domain is incomplete and does not exhibit proteolytic activity. We have generated a trial sequence of putative activated protein Z (PZa) by identifying amino acid mutations in the SP‐like domain that might reasonably resurrect the serine protease catalytic activity of PZ. The structure of the activated form was then modeled based on the proposed sequence using homology modeling and solvent‐equilibrated molecular dynamics simulations. In silico docking of inhibitors of FVIIa and FXa to the putative active site of equilibrated PZa, along with structural comparison with its homologous proteins, suggest that the designed PZa can possibly act as a serine protease.
A consistent metric for nestedness analysis in ecological systems: reconciling concept and measurement
Authors: Almeida‐Neto Mário , Guimarães Paulo , Guimarães Paulo R. , Loyola Rafael D. , Ulrich Werner
Published: May 2008

Nestedness has been widely reported for both metacommunities and networks of interacting species. Even though the concept of this ecological pattern has been well‐defined, there are several metrics by which it can be quantified. We noted that current metrics do not correctly quantify two major properties of nestedness: (1) whether marginal totals (i.e. fills) differ among columns and/or among rows, and (2) whether the presences (1's) in less‐filled columns and rows coincide, respectively, with those found in the more‐filled columns and rows. We propose a new metric directly based on these properties and compare its behavior with that of the most used metrics, using a set of model matrices ranging from highly‐nested to alternative structures in which no nestedness should be detected. We also used an empirical dataset to explore possible biases generated by the metrics as well as to evaluate correlations between metrics. We found that nestedness has been quantified by metrics that inappropriately detect this pattern, even for matrices in which there is no nestedness. In addition, the most used metrics are prone to type I statistical errors while our new metric has better statistical properties and consistently rejects a nested pattern for different types of random matrices. The analysis of the empirical data showed that two nestedness metrics, matrix temperature and the discrepancy measure, tend to overestimate the degrees of nestedness in metacommunities. We emphasize and discuss some implications of these biases for the theoretical understanding of the processes shaping species interaction networks and metacommunity structure.
What is a food allergen?
Authors: Lucas J. S. A. , Atkinson R. G.
Published: May 2008

With the increasing prevalence of allergies, accurate identification of allergens is a major priority for allergists, scientists, the food industry, and food regulators. Knowledge of allergens is essential for risk assessment of novel genetically modified (GM) foods, and to develop recombinant proteins for the treatment and diagnosis of allergies. This Opinion Paper considers the lack of standardization for the clinical and scientific assessment of proteins before they are labelled as allergens. Food allergens are being reported and recorded in allergen databases, with minimal or in some cases apparently no published justification. IgE binding, rather than clinically relevant reactivity, is inappropriately used to confirm allergenicity. Using kiwifruit as an example, the lack of rigor in identifying allergenic proteins is considered.
Reduced learning ability as a consequence of evolutionary adaptation to nutritional stress in Drosophila melanogaster
Authors: KOLSS MUNJONG , KAWECKI TADEUSZ J.
Published: May 2008

Abstract 1. Dietary conditions affect cognitive abilities of many species, but it is unclear to what extent this physiological effect translates into an evolutionary relationship.

2. A reduction of competitive ability under nutritional stress has been reported as a correlated response to selection for learning ability in Drosophila melanogaster. Here we test whether the reverse holds as well, i.e. whether an evolutionary adaptation to poor food conditions leads to a decrease in learning capacities.

3. Populations of D. melanogaster were: (i) not subject to selection (control), (ii) selected for improved learning ability, (iii) selected for survival and fast development on poor food, or (iv) subject to both selection regimes.

4. There was no detectable response to selection for learning ability.

5. Selection on poor food led to higher survival, faster development and smaller adult size as a direct response, and to reduced learning ability as a correlated response. This study supports the hypothesis that adaptation to poor nutrition is likely to trade off with the evolution of improved learning ability.
Effects of shoreline development on the nearshore environment in large deep oligotrophic lakes
Authors: ROSENBERGER ELIZABETH E. , HAMPTON STEPHANIE E. , FRADKIN STEVEN C. , KENNEDY BRIAN P.
Published: May 2008

1. In large deep oligotrophic lakes, the shallow nearshore waters may provide the most important habitat for animals to feed and breed, and it is this area of the lake where humans are most likely to have initial impacts as the shoreline is developed. Nutrients in fertilizers, sediments and sewage effluents are likely to be rapidly intercepted by nearshore algae at the lake edge, having heterogeneous effects nearshore before offshore effects are noted.

2. Here we examined the spatially explicit effects of residential development on nearshore periphyton communities in three large deep oligotrophic lakes that have all experienced modest residential development in the Pacific Northwest of the United States. We demonstrate that substantial nearshore changes in the basal food web are detectable even with low levels of shoreline development. These changes can potentially affect whole‐lake food web dynamics.

3. For our primary study site (Lake Crescent, Washington, USA), we found that algal biomass and accumulation of detritus were higher at developed sites. In addition, both macroinvertebrate and periphyton communities exhibited a shift in composition with more detritivores and filamentous green algae at developed sites. These differences were more pronounced during the spring than at other times of year.

4. A complementary investigation of field patterns in Priest Lake and Lake Pend Oreille (Idaho, USA) suggested that, although spatial and temporal patterns were idiosyncratic, indicators of productivity and the presence of filamentous green algae were generally higher at developed sites across lakes.

5. Stable isotope signatures and water column nutrients were not useful in distinguishing developed and undeveloped sites, increasing the potential usefulness of periphyton monitoring during early stages of lake development.

6. A laboratory investigation suggested that common macroinvertebrate grazers assimilated a much greater proportion of diatoms than the filamentous green algae that are associated with fertilization at developed sites.

7. These findings have at least two clear implications: (i) periphyton may be used to detect human impacts before disturbance is evident in offshore monitoring programmes and (ii) nearshore impacts in response to modest residential development have the potential to disrupt lake food web dynamics.
Efficient production of monoclonal antibodies recognizing specific structures in Caenorhabditis elegans embryos using an antigen subtraction method
Authors: Takeda Kazumasa , Watanabe Chie , Qadota Hiroshi , Hanazawa Momoyo , Sugimoto Asako
Published: May 2008

Monoclonal antibodies (mAbs) have been widely used to probe molecular components of specific cell types or cellular structures. We have developed a method to enrich antigens of low abundance in heterogeneous molecule mixtures by subtracting abundant antigens. The subtracted immunogen mixture is then used for immunization, which significantly increases the production of mAbs that exhibit specific staining patterns. By applying this “antigen subtraction” method to the embryonic extract of Caenorhabditis elegans, we have successfully isolated 35 mAbs that recognize specific structures, including P granules, muscles, the pharynx, and subsets of hypodermal cells; some of the mAbs revealed previously unreported cellular structures. This antigen subtraction approach can be used in various applications to produce mAbs against relatively scarce antigens in complex molecular mixtures. The mAbs will be useful tools for developmental and cell biological studies.
Identification of a putative human mitochondrial thymidine monophosphate kinase associated with monocytic/macrophage terminal differentiation
Authors: Chen Yen‐Ling , Lin Da‐Wei , Chang Zee‐Fen
Published: May 2008

Mitochondrial DNA synthesis requires the supply of thymidine triphosphate (dTTP) independent of nuclear DNA replication. In resting and differentiating cells that withdraw from the cell cycle, mitochondrial thymidine kinase 2 (TK2) mediates thymidine monophosphate (dTMP) formation for the dTTP biosynthesis in mitochondria. However, a thymidine monophosphate kinase (TMPK) that phosphorylates dTMP to form thymidine diphosphate (dTDP) in mitochondria remains undefined. Here, we identified an expressed sequence tag cDNA, which encodes a TMPK with a mitochondrial import sequence at its N‐terminus designated as TMPK2. HeLa cells expressing TMPK2 fused to green fluorescent protein (GFP) displayed green fluorescence in mitochondria. Over‐expression of TMPK2 increased the steady‐state level of cellular dTTP and promoted the conversion of radioactive labeled‐thymidine and ‐dTMP to dTDP and dTTP in mitochondria. TMPK2 RNA was detected in several tissues and erythroblastoma cell lines. We also generated TMPK2 antibody and used it for immunofluorescence staining to demonstrate endogenous expression of TMPK2 in mitochondria of erythroblastoma cells. Finally, we showed that TMPK2 protein expression was upregulated in monocyte/macrophage differentiating cells, suggesting the coordinated regulation of TMPK2 expression with the terminal differentiation program.
The prevalence and nature of intellectual disability in Norwegian prisons
Authors: Søndenaa E. , Rasmussen K. , Palmstierna T. , Nøttestad J.
Published: May 2008

Background  The objective of the study was to calculate the prevalence of inmates with intellectual disabilities (ID), and identify historical, medical and criminological characteristics of a certain impact.

Methods  A random sample of 143 inmates from a Norwegian prison cross sectional sample was studied. The Hayes Ability Screening Index (HASI) was validated with the Wechsler Abbreviated Scale of Intelligence (WASI).

Results  The prevalence of inmates with ID, IQ < 70, was 10.8%. Some essential characteristics of inmates with ID were more frequent medication for mental disorders, a higher number of imprisonments, less drug abuse and less education than the other inmates. The results indicated that the HASI is a valid tool for screening of ID for the Norwegian inmates.

Conclusions  The prevalence of ID in Norwegian inmates is significant, measured by WASI and HASI. Identification, rehabilitation and care, concerning an intellectual handicap, are mostly absent in the Norwegian criminal justice system.
The patient movement as an emancipation movement
Authors: Williamson Charlotte
Published: May 2008

Objective  To suggest that the patient movement is an emancipation movement.

Background  The patient movement is young and fragmented; and it can seem confusing because it lacks an explicit ideology with intellectual and theoretical underpinnings.

Methods  Drawing mainly on the experiences and the published writings of patient activists, the author identified eight aspects of the patient movement that could be compared with aspects of recognized emancipation movements: the radicalization of activists; the creation of new knowledge; the identification of guiding principles; the sense of direction; the unmasking of new issues; schisms within the movement and allies outside it; and the gradual social acceptance of some of the ideas (here standards of health care) that activists work to promote.

Results  Similarities between certain aspects of the patient movement and of the recognized emancipation movements were close.

Conclusion  The patient movement can be regarded as an emancipation movement, albeit an immature one.
Evaluating the use of a modified CAHPS® survey to support improvements in patient‐centred care: lessons from a quality improvement collaborative
Authors: Davies Elizabeth , Shaller Dale , Edgman‐Levitan Susan , Safran Dana G , Oftedahl Gary , Sakowski John , Cleary Paul D
Published: May 2008

Objectives  To evaluate the use of a modified Consumer Assessment of Healthcare Providers and Systems (CAHPS®) survey to support quality improvement in a collaborative focused on patient‐centred care, assess subsequent changes in patient experiences, and identify factors that promoted or impeded data use.

Background  Healthcare systems are increasingly using surveys to assess patients’ experiences of care but little is established about how to use these data in quality improvement.

Design  Process evaluation of a quality improvement collaborative.

Setting and participants  The CAHPS team from Harvard Medical School and the Institute for Clinical Systems Improvement organized a learning collaborative including eight medical groups in Minnesota.

Intervention  Samples of patients recently visiting each group completed a modified CAHPS® survey before, after and continuously over a 12‐month project. Teams were encouraged to set goals for improvement using baseline data and supported as they made interventions with bi‐monthly collaborative meetings, an online tool reporting the monthly data, a resource manual called The CAHPS® Improvement Guide, and conference calls.

Main outcome measures  Changes in patient experiences. Interviews with team leaders assessed the usefulness of the collaborative resources, lessons and barriers to using data.

Results  Seven teams set goals and six made interventions. Small improvements in patient experience were observed in some groups, but in others changes were mixed and not consistently related to the team actions. Two successful groups appeared to have strong quality improvement structures and had focussed on relatively simple interventions. Team leaders reported that frequent survey reports were a powerful stimulus to improvement, but that they needed more time and support to engage staff and clinicians in changing their behaviour.

Conclusions  Small measurable improvements in patient experience may be achieved over short projects. Sustaining more substantial change is likely to require organizational strategies, engaged leadership, cultural change, regular measurement and performance feedback and experience of interpreting and using survey data.
Information needs and preferences of low and high literacy consumers for decisions about colorectal cancer screening: utilizing a linguistic model
Authors: Smith Sian K , Trevena Lyndal , Nutbeam Don , Barratt Alexandra , McCaffery Kirsten J
Published: May 2008

Context  The use of written decision aids (DAs) in clinical practice has proliferated. However, few DAs have been developed for low literacy users, despite this group having low knowledge about healthcare and lacking involvement in health decisions.

Objective  To explore the information needs and understanding of adults with varying literacy in relation to colorectal cancer screening, and to consider their responses to two versions of a decision aid.

Participants  Thirty‐three men and women aged 45–74 years were recruited from Adult Basic Education classes (n = 17) and University Continuing Education programs (n = 16).

Methods  We used qualitative methods (in‐depth, semi‐structured interviews) to compare and contrast the views of adults with lower and higher literacy levels, to gain a better understanding of how people with lower literacy value and interpret specific DA content and components; and determine whether needs and preferences are specific to lower literacy groups or generic across the broad literacy spectrum.

Results  Regardless of literacy perspective, participants’ interpretations of the DA were shaped by their prior knowledge and expectations, as well as their values and preferences. This influenced perceptions of the DAs role in supporting informed decision making. A linguistic theoretical model was applied to interpret the findings. This facilitated considerations beyond the traditional focus on the readability of materials.

Conclusion  Decision aids developers may find it useful to apply alternative approaches (linguistic) when creating DAs for consumers of varying literacy.
Evaluation of fungicides for the control of Botryosphaeria corticola on cork oak in Catalonia (NE Spain)
Authors: Luque J. , Pera J. , Parladé J.
Published: May 2008

Botryosphaeria canker of cork oak (Quercus suber L.), caused by Botryosphaeria corticola, is a well‐known factor contributing to the decline of this forest species and is a serious disease in the main cork‐producing countries of the Western Mediterranean basin. In this work, fungicides with the potential for controlling the disease were selected using a combination of in vitro tests and field trials. Fourteen fungicides in different chemical families were tested in vitro to evaluate their effect on inhibition of mycelial growth. The most effective fungicides were benomyl, carbendazim, cyprodinil + fludioxonil, thiabendazol and thiophanate‐methyl; these compounds were then further tested under field conditions. In the field trials, carbendazim and thiophanate‐methyl were the most effective fungicides, as shown by efficacy indices, in reducing debarked trunk surface affected by cankers (76% and 50–65%, respectively). These results suggest that the occurrence of Botryosphaeria canker on cork oak can be reduced effectively with the application of selected fungicides after cork removal from the trees.
Childhood dermatomycoses study in Sfax hospital, Tunisia
Authors: Sellami A. , Sellami H. , Makni F. , Mezghani S. , Cheikh‐Rouhou F. , Marrekchi S. , Turki H. , Ayadi A.
Published: May 2008

Mycoses are frequent affections in childhood. Fungal type varies according to the age and the affected organ. The aim of this study was to determine the aetiological agents of childhood dermatomycoses and to draw attention to the diversity of their clinical manifestations. Retrospective study dealing with children’s cases with age <16‐year old and having dermatomycosis diagnosed between 1991 and 2005 at the Parasitology and Mycology Laboratory of Sfax University Hospital. A total of 4559 children suspected to have superficial mycoses were examined. Dermatomycosis diagnosis was confirmed in 49.3% of cases. Dermatophytes were the most prevalent fungal agents and accounted for 1865 cases (80.6%) dominated by Trichophyton violaceum (54.1%) and Microsporum canis (24.5%). Tinea capitis (69.4%) was the most common type of infection, followed by tinea corporis (20%). Superficial yeast infections (442 cases) were dominated by Malassezia infections (71%). Candida infections were mainly due to Candida albicans (58%). The clinical features of paediatric dermatomycoses vary with the age of the children: tinea capitis and tinea corporis were more frequent before 13 years of age. After this age, tinea versicolor and onychomycoses became more common.
Determination of the efficacy of terbinafine hydrochloride nail solution in the topical treatment of dermatophytosis in a guinea pig model
Authors: Ghannoum Mahmoud A. , Long Lisa , Pfister William R.
Published: May 2008

Currently available topical antifungals are often not satisfactory for the treatment of nail infections, because of the inability to penetrate the nail plate. Terbinafine HCl nail solution is a novel antifungal formulation containing a nail penetration enhancer dodecyl‐2‐N,N‐dimethylaminopropionate hydrochloride (DDAIP HCl, trade name NexACT®‐88). In this study, we used a guinea pig model of Trichophyton mentagrophytes dermatophytosis and evaluated the clinical and mycological efficacy of different terbinafine HCl nail solutions (TNS) formulated with or without DDAIP HCl. Ciclopirox (8%) nail lacquer (Penlac®), the only Food and Drug Administration approved topical treatment for onychomycosis, was used as a comparator. Following the IACUC Guidelines, the skin of male albino guinea pigs was abraded under anaesthesia. Each animal was infected with T. mentagrophytes ATCC 24953 (cell suspension containing 1 × 107 conidia). The experimental animals were divided into 11 groups (five animals per group) and tested with the following formulations: vehicle control, 0.5% DDAIP HCl, 1%, 5% and 10% TNS (without DDAIP HCl), 1% TNS with 0.5%, 2.5% and 5.0% DDAIP HCl, 5% and 10% TNS with 0.5% DDAIP HCl, 8% ciclopirox nail lacquer and an untreated control group. Evaluation of clinical and mycological efficacy was performed 72 h after completion of a 7‐day treatment regimen. Skin biopsy samples were processed for histopathological examination. The infected untreated control guinea pigs showed patches of hair loss and ulcerated or scaly skin and fungal invasion of hair roots. The vehicle and 0.5% DDAIP HCl treated groups showed minimal clinical efficacy (only 11% and 5%, respectively). In contrast, all three concentrations of TNS (1%, 5% and 10% terbinafine HCl) formulated with or without 0.5% DDAIP HCl showed 100% mycological efficacy by the hair root invasion test. Clinical efficacy of the 5% and 10% TNS improved with addition of 0.5% DDAIP HCl (47.4% and 73.8% vs. 68.4% and 89.5%, respectively). In addition, no fungal elements were detected in the treated guinea pig skin. All formulations of TNS resulted in a higher clinical and mycological efficacy compared with the 8% ciclopirox nail lacquer (P = 0.0444). In conclusion, TNS containing 1%, 5% and 10% terbinafine HCl formulated with and without DDAIP HCl demonstrated high antifungal efficacy in experimental dermatophytosis. Addition of 0.5% DDAIP HCl to 5% and 10% TNS significantly enhanced the clinical and mycological efficacy of these formulations which were superior compared with the 8% ciclopirox nail lacquer. Evaluation of the 1%, 5% and 10% TNS in clinical trials for the treatment of dermatophytosis and onychomycosis is warranted.
A general framework for the distance–decay of similarity in ecological communities
Authors: Morlon Hélène , Chuyong George , Condit Richard , Hubbell Stephen , Kenfack David , Thomas Duncan , Valencia Renato , Green Jessica L.
Published: May 2008

Species spatial turnover, or β‐diversity, induces a decay of community similarity with geographic distance known as the distance–decay relationship. Although this relationship is central to biodiversity and biogeography, its theoretical underpinnings remain poorly understood. Here, we develop a general framework to describe how the distance–decay relationship is influenced by population aggregation and the landscape‐scale species‐abundance distribution. We utilize this general framework and data from three tropical forests to show that rare species have a weak influence on distance–decay curves, and that overall similarity and rates of decay are primarily influenced by species abundances and population aggregation respectively. We illustrate the utility of the framework by deriving an exact analytical expression of the distance–decay relationship when population aggregation is characterized by the Poisson Cluster Process. Our study provides a foundation for understanding the distance–decay relationship, and for predicting and testing patterns of beta‐diversity under competing theories in ecology.
The efficacy of self‐monitoring of blood glucose in the management of patients with type 2 diabetes treated with a gliclazide modified release–based regimen. A multicentre, randomized, parallel‐group, 6‐month evaluation (DINAMIC 1 study)
Authors: Barnett A. H. , Krentz A. J. , Strojek K. , Sieradzki J. , Azizi F. , Embong M. , Imamoglu S. , Perušičová J. , Uličiansky V. , Winkler G.
Published: May 2008

Aim:  To determine if therapeutic management programmes for type 2 diabetes that include self‐monitoring of blood glucose (SMBG) result in greater reductions in glycated haemoglobin (HbA1c) compared with programmes without SMBG in non‐insulin requiring patients.

Methods:  Multicentre, randomized, parallel‐group trial. A total of 610 patients were randomized to SMBG or non‐SMBG groups. Patients in both groups received the same oral antidiabetic therapy using a gliclazide modified release (MR)–based regimen for 27 weeks. The primary efficacy end‐point was the difference between groups in HbA1c at the end of observation.

Results:  A total of 610 patients were randomized: 311 to the SMBG group and 299 to the non‐SMBG group. HbA1c decreased from 8.12 to 6.95% in the SMBG group and from 8.12 to 7.20% in the non‐SMBG group; between‐group difference was 0.25% (95% CI: 0.06, 1.03; p = 0.0097). Symptoms suggestive of mild to moderate hypoglycaemia was the most commonly reported adverse event, reported by 27 (8.7%) and 21 (7.0%) patients in the SMBG and non‐SMBG groups, respectively; the incidence of symptomatic hypoglycaemia was lower in the SMBG group.

Conclusion:  In patients with type 2 diabetes, the application of SMBG as an adjunct to oral antidiabetic agent therapy results in further reductions in HbA1c.
Comparison of the antilipolytic effects of an A1adenosine receptor partial agonist in normal and diabetic rats
Authors: Dhalla A. K. , Santikul M. , Chisholm J. W. , Belardinelli L. , Reaven G. M.
Published: May 2008

Introduction and Aims: Elevated plasma free fatty acid (FFA) concentrations play a role in the pathogenesis of type 2 diabetes (2DM). Antilipolytic agents that reduce FFA concentrations may be potentially useful in the treatment of 2DM. Our previous observation that CVT‐3619 lowered plasma FFA and triglyceride concentrations in rats and enhanced insulin sensitivity in rodents with dietary‐induced forms of insulin resistance suggested that it might be of use in the treatment of patients with 2DM. The present study was undertaken to compare the antilipolytic effects of CVT‐3619 in normal (Sprague Dawley, SD) and Zucker diabetic fatty (ZDF) rats.

Results: ZDF rats had significantly higher fat pad weight, glucose, insulin and FFA concentrations than those of SD rats. EC50values for forskolin‐stimulated FFA release from isolated adipocytes from SD and ZDF rats were 750 and 53 nM, respectively (p < 0.05). Maximal forskolin stimulation of FFA release was significantly (p < 0.01) less in ZDF rats (133 ± 60 μM) compared with SD rats (332 ± 38 μM). EC50values for isoproterenol to increase lipolysis in adipocytes from SD and ZDF rats were 2 and 7 nM respectively. Maximal isoproterenol‐stimulated lipolysis was significantly (p < 0.01) lower in adipocytes from ZDF rats (179 ± 23 μM) compared with SD rats (343 ± 27 μM). Insulin inhibited lipolysis in adipocytes from SD rats with an IC50value of 30 pM, whereas adipocytes from ZDF rats were resistant to the antilipolytic actions of insulin. In contrast, IC50values for CVT‐3619 to inhibit the release of FFA from SD and ZDF adipocytes were essentially the same (63 and 123 nM respectively). CVT‐3619 inhibited lipolysis more than insulin in both SD (86 vs. 46%, p < 0.001) and ZDF (80 vs. 13%, p < 0.001) adipocytes. Inin vivoexperiments, CVT‐3619 (5 mg/kg, PO) lowered FFA to a similar extent in both groups. Plasma concentrations of CVT‐3619 were not different in SD and ZDF rats. There was no significant difference in the messenger RNA expression of the A1receptors relative to β‐actin expression in adipocytes from SD (0.98 ± 0.2) and ZDF rats (0.99 ± 0.3).

Conclusion: The antilipolytic effects of CVT‐3619 appear to be independent of insulin resistance and animal model.
Novel pathways for glycaemic control in type 2 diabetes: focus on bile acid modulation
Authors: Brinton Eliot A.
Published: May 2008

Type 2 diabetes is a common disorder with high risk of macrovascular and microvascular complications. These complications are largely driven by hyperglycaemia, dyslipidaemia and hypertension, for which aggressive treatment is thus warranted. Achieving and maintaining control of all three risk factors is especially difficult, however, and new therapeutic approaches could be useful. Bile acids have a well‐established and important role in cholesterol homeostasis. Normally, their levels are maintained primarily by ileal reabsorption and enterohepatic recycling. Bile acid sequestrants bind bile acids in the intestine, reduce this recycling and deplete the bile acid pool, thereby stimulating use of hepatic cholesterol for bile acid synthesis, which leads to accelerated removal of LDL from the plasma and a decrease in LDL‐cholesterol levels. Interestingly, recent evidence suggests that bile acid sequestrants can lower glucose levels to a clinically meaningful degree. This review presents this evidence and the possible mechanisms by which these glucose‐lowering effects occur and discusses the apparently unique ability of bile acid sequestrants among lipid‐lowering agents to significantly improve two cardiovascular risk factors, hyperglycaemia and dyslipidaemia. There is renewed interest in the use of bile acid sequestrants in individuals with type 2 diabetes, most of whom would benefit from additional reductions in both LDL‐cholesterol and glycaemia.
Biphasic insulin aspart 30 treatment improves glycaemic control in patients with type 2 diabetes in a clinical practice setting: Chinese PRESENT study
Authors: Gao Y. , Guo X. H. , Vaz J. A. ,   PRESENT Study Group
Published: May 2008

Aim:  PRESENT (Physicians’ Routine Evaluation of Safety and Efficacy of NovoMix® 30 Therapy) is the largest, multinational, open‐labelled, uncontrolled and completed observational study of the efficacy and safety of biphasic insulin aspart 30 (BIAsp 30) treatment in clinical practice. We present results of 3 months of treatment in Chinese patients with type 2 diabetes mellitus who were inadequately controlled on current treatment.

Methods:  Patients received BIAsp 30 treatment with or without oral antidiabetic drugs (OADs). Patients were categorized according to their treatment prior to entering the study: drug‐naive (n = 3697), OAD (n = 4754), insulin (n = 2392) or OAD + insulin (n = 817).

Results:  At 3 months, significant reductions from baseline were observed in the mean haemoglobin A1c (HbA1c) (−2.24 ± 1.67, −2.04 ± 1.57, −1.82 ± 1.49 and −1.86 ± 1.61%), fasting plasma glucose (−3.93 ± 3.12, −3.51 ± 2.55, −2.99 ± 2.93 and −3.38 ± 3.16 mmol/l) and postprandial plasma glucose (−7.09 ± 4.92, −6.51 ± 4.02, −5.20 ± 4.31 and −5.50 ± 4.32 mmol/l) in the drug‐naive, OAD, insulin and insulin + OAD groups respectively (p < 0.001). The proportions of patients in each group achieving target HbA1c of less than 7% were higher at 3 months (49.5, 51.8, 51.0 and 48.3%) compared with baseline (3.2, 4.2, 7.1 and 8.3%). The rates of hypoglycaemic episodes (events per patient‐year) were lower at the end of the study in all the groups compared with baseline. Hypoglycaemic episodes were mostly minor and diurnal in nature. A total of 151 adverse drug reactions were reported, of which five were serious adverse drug reaction (SADRs). These SADRs were all symptoms of local hypersensitivity.

Conclusions:  The use of BIAsp 30 monotherapy or in combination with OADs in clinical practice was efficacious and safe in Chinese patients with poorly controlled type 2 diabetes.
All‐cause mortality risk predictors in a preventive cardiology clinic cohort‐examining diabetes and individual metabolic syndrome criteria: a PRECIS database study
Authors: Doshi K. B. , Kashyap S. R. , Brennan D. M. , Hoar B. M. , Cho L. , Hoogwerf B. J.
Published: May 2008

Aim:  It is unclear if metabolic syndrome (MS) is equal to type 2 diabetes mellitus (DM) in predicting cardiovascular disease (CVD) risk and mortality, and its prognostic value compared to Framingham risk model is controversial. We assessed mortality, CVD risk and prevalence in patients with DM and those without DM who met National Cholesterol Education Program Adult Treatment Panel III (NCEP‐ATP III) MS criteria compared to patients without DM or MS. We analysed which component(s) of NCEP MS criteria had greatest predictive value for mortality.

Methods:  Retrospective cohort analysis of 1189 DM, 1241 MS (fasting glucose < 126 mg/dl and ≥3 components NCEP‐ATP III criteria) and 3023 non‐DM/non‐MS patients presented for baseline visit to Preventive Cardiology clinic between 1995 and 2006, whose subsequent vital status was determined for a median of 5.2 years. The association with mortality was determined by Cox proportional hazards models. The incremental predictive value of MS components was performed by concordance indexes.

Results and conclusion:  DM group had highest mortality and CVD prevalence vs. MS and non‐DM/non‐MS groups respectively (all p ≤ 0.001). Patients with MS criteria had increased CVD prevalence and 1.5‐fold increased mortality vs. non‐DM/non‐MS group (all p < 0.02). In NCEP MS criteria, only fasting glucose significantly predicted mortality in MS group (p = 0.05). MS criteria predicted CVD prevalence in a parallel manner to Framingham risk score assessment. In a cohort of patients at high risk for CVD whose risk factors are being treated, presence of diabetes in addition to plasma glucose within NCEP MS criteria strongly predicts all‐cause mortality.
An evidence‐based definition of lifelong premature ejaculation: report of the International Society for Sexual Medicine Ad Hoc Committee for the Definition of Premature Ejaculation
Authors: McMahon Chris G. , Althof Stanley , Waldinger Marcel D. , Porst Hartmut , Dean John , Sharlip Ira , Adaikan P.G. , Becher Edgardo , Broderick Gregory A. , Buvat Jacques , Dabees Khalid , Giraldi Annamaria , Giuliano François , Hellstrom Wayne J.G. , Incrocci Luca , Laan Ellen , Meuleman Eric , Perelman Michael A. , Rosen Raymond , Rowland David , Segraves Robert
Published: May 2008

OBJECTIVE

To develop a contemporary, evidence‐based definition of premature ejaculation (PE).

METHODS

There are several definitions of PE; the most commonly quoted, the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders – 4th Edition – Text Revision, and other definitions of PE, are all authority‐based rather than evidence‐based, and have no support from controlled clinical and/or epidemiological studies. Thus in August 2007, the International Society for Sexual Medicine (ISSM) appointed several international experts in PE to an Ad Hoc Committee for the Definition of PE. The committee met in Amsterdam in October 2007 to evaluate the strengths and weaknesses of current definitions of PE, to critically assess the evidence in support of the constructs of ejaculatory latency, ejaculatory control, sexual satisfaction and personal/interpersonal distress, and to propose a new evidence‐based definition of PE.

RESULTS

The Committee unanimously agreed that the constructs which are necessary to define PE are rapidity of ejaculation, perceived self‐efficacy, and control and negative personal consequences from PE. The Committee proposed thatlifelong PE be defined as a male sexual dysfunction characterized by ejaculation which always or nearly always occurs before or within about one minute of vaginal penetration, and the inability to delay ejaculation on all or nearly all vaginal penetrations, and negative personal consequences, such as distress, bother, frustration and/or the avoidance of sexual intimacy. This definition is limited to men with lifelong PE who engage in vaginal intercourse. The panel concluded that there are insufficient published objective data to propose an evidence‐based definition of acquired PE.

CONCLUSION

The ISSM definition of lifelong PE represents the first evidence‐based definition of PE. This definition will hopefully lead to the development of new tools and patient‐reported outcome measures for diagnosing and assessing the efficacy of treatment interventions, and encourage ongoing research into the true prevalence of this disorder, and the efficacy of new pharmacological and psychological treatments.
Political Risk and Export Promotion: Evidence from Germany
Authors: Moser Christoph , Nestmann Thorsten , Wedow Michael
Published: May 2008

Political risk represents an important hidden transaction cost that reduces international trade. This paper investigates the claim that public export credit guarantees mitigate this friction to trade flows and hence promote exports. We employ an empirical trade gravity model, where we explicitly control for political risk in the importing country in order to evaluate the effect of export guarantees. Using a novel data set on guarantees, we estimate the effect of guarantees in a static and dynamic panel model. We find a statistically and economically significant positive effect of public export guarantees on exports which indicates that export promotion is indeed effective. Furthermore, political risk turns out to be an important obstacle for exports and hence should be taken into account in any empirical model of trade.
A Meta‐Analysis of General and Partial Equilibrium Simulations of Trade Liberalisation under the Doha Development Agenda
Authors: Hess Sebastian , Von Cramon‐Taubadel Stephan
Published: May 2008

Model‐based simulation of welfare effects is commonly used to make a case for trade liberalisation and to inform participants and stakeholders in trade negotiations. However, the simulated welfare effects of trade liberalisation vary greatly, even across studies that model similar liberalisation scenarios. This undermines confidence in the reliability of model‐based simulations. A meta‐analysis of over 100 studies that model WTO Doha Development Agenda trade negotiation outcomes is employed to identify characteristics of models, databases and liberalisation experiments that influence simulated welfare effects. Meta‐regressions produce plausible results and explain a significant proportion of the variation in simulated welfare effects in a representative sample of Doha Development Agenda trade liberalisation studies. Results also reveal that many quantitative trade policy simulation studies fail to adequately document the assumptions and data on which they are based.
Non‐at‐risk adolescents' attitudes towards reading in a Singapore secondary school
Authors: Bokhorst‐Heng Wendy , Pereira Delfin
Published: May 2008

In this paper, we examine the various nuanced dimensions of adolescents' dispositions towards reading in one secondary school in Singapore, where a high‐stakes examination culture often threatens to colonise the practices of leisure reading. Our focus is on the better and more avid readers as they were the ones that developed the more negative attitudes towards reading at the end of their first year in secondary school. Our analysis found that there were no significant differences between boys and girls in their declining attitudes, and that for both ‘intrinsic motivation’ saw the greatest decline. However, attitudes related to learning orientation remained stable, suggesting both the impact of constraints in an exam‐oriented educational structure as well as possibilities for developing reading pedagogy and adolescent reading programmes. We argue that the more educators are aware of the multidimensionality and complexity of the attitudes and values that students bring to their reading, the more effectively they will be able to design and implement programmes and pedagogy to foster positive attitudes and promote a lifelong love for reading.
Children's inference generation across different media
Authors: Kendeou Panayiota , Bohn‐Gettler Catherine , White Mary Jane , Van Den Broek Paul
Published: May 2008

In the present study, we investigated the degree to which children's inference generation ability generalises across different media and predicts narrative comprehension over and above basic language skills and vocabulary. To address both aims, we followed two cohorts of children aged 4 and 6 as they turned 6 and 8 years old, respectively. At each time point we assessed their inference and narrative comprehension skills using aural, televised and written stories. We also assessed their basic language skills and vocabulary. The findings demonstrated that children's inference generation skills were highly inter‐related across different media for both cohorts and at both time points. Also, children's inference generation had a significant contribution to children's narrative comprehension over and above basic language skills, vocabulary and media factors. The current set of findings has important theoretical and practical implications for early diagnosis and intervention in young children's high‐order comprehension skills.
Revisiting print exposure: exploring differential links to vocabulary, comprehension and reading rate
Authors: Martin‐Chang Sandra Lyn , Gould Odette N.
Published: May 2008

Undergraduates (N=171) completed a revised version of the Author Recognition Test (Stanovich & West, 1989). The resulting print exposure scores were divided into two dimensions: personal reading experience (primary print knowledge – PPK) and secondary print knowledge (SPK). Both PPK and SPK were correlated with print exposure, but not with each other. PPK correlated more strongly with reading‐related variables (vocabulary, comprehension and reading rate) than did SPK. Of particular importance, PPK accounted for variance in all three criterion variables after the effects of SPK had been factored out. Thus, these data support the notion that it is the act of reading over and above memory for reading‐related information that furthers the development of linguistic skill.