bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo analyzes of dystroglycan function during somitogenesis in Xenopus laevis
Authors: Hidalgo Magdalena , Sirour Cathy , Bello Valérie , Moreau Nicole , Beaudry Michèle , Darribère Thierry
Published: December 2008

Dystroglycan (Dg) is a cell adhesion receptor for laminin that has been reported to play a role in skeletal muscle cell stability, cytoskeletal organization, cell polarity, and signaling. Here we show that Dg is expressed at both the notochord/somite and the intersomitic boundaries, where laminin and fibronectin are accumulated during somitogenesis. Inhibition of Dg function with morpholino antisense oligonucleotides or a dominant negative mutant results in the normal segmentation of the presomitic mesoderm but affects the number, the size, and the integrity of somites. Depletion of Dg disrupts proliferation and alignment of myoblasts without affecting XMyoD and XMRF4 expression. It also leads to defects in laminin deposition at the intersomitic junctions, whereas expression of integrin β1 subunits and fibronectin assembly occur normally. Our results show that Dg is critical for both proliferation and elongation of somitic cells and that the Dg‐cytoplasmic domain is required for the laminin assembly at the intersomitic boundaries. Developmental Dynamics 238:1332–1345, 2009. © 2008 Wiley‐Liss, Inc.
Molecular imaging of glucose uptake in oral neoplasia following topical application of fluorescently labeled deoxy‐glucose
Authors: Nitin Nitin , Carlson Alicia L. , Muldoon Tim , El‐Naggar Adel K. , Gillenwater Ann , Richards‐Kortum Rebecca
Published: December 2008

The clinical value of assessing tumor glucose metabolism via F‐18 fluorodeoxyglucose (FDG) PET imaging in oncology is well established; however, the poor spatial resolution of PET is a significant limitation especially for early stage lesions. An alternative technology is optical molecular imaging, which allows for subcellular spatial resolution and can be effectively used with topical contrast agents for imaging epithelial derived cancers. The goal of this study was to evaluate the potential of optical molecular imaging of glucose metabolism to aid in early detection of oral neoplasia. Fluorescently labeled deoxyglucose (2‐NBDG (2‐[N‐(7‐nitrobenz‐2‐oxa‐1,3‐diazol‐4‐yl)amino]‐2‐deoxy‐D‐glucose)) was applied topically to tissue phantoms, fresh oral biopsies (n = 32) and resected tumors specimens (n = 2). High‐resolution imaging results show that 2‐NBDG can be rapidly delivered to oral epithelium using topical application. In normal epithelium, the uptake of 2‐NBDG is limited to basal epithelial cells. In contrast, high‐grade dysplasia and cancers show uptake of 2‐NBDG in neoplastic cells throughout the lesion. Following 2‐NBDG labeling, the mean fluorescence intensity of neoplastic tissue averages 3.7 times higher than that of matched nonneoplastic oral biopsies in samples from 20 patients. Widefield fluorescence images of 8‐paired oral specimens were obtained pre and postlabeling with 2‐NBDG. Prior to labeling, neoplastic samples showed significantly lower autofluorescence than nonneoplastic samples. The fluorescence of neoplastic samples increased dramatically after labeling; the differential increase in fluorescence was on average 30 times higher in neoplastic samples than in normal samples. Topical application of 2‐NBDG can therefore provide image contrast in both widefield and high‐resolution fluorescence imaging modalities, highlighting its potential in early detection of oral neoplasia. © 2008 Wiley‐Liss, Inc.
Functionally gradient chitosan/hydroxyapatite composite scaffolds for controlled drug release
Authors: Teng Shu‐Hua , Lee Eun‐Jung , Wang Peng , Jun Shin‐Hee , Han Cheol‐Min , Kim Hyoun‐Ee
Published: December 2008

This study explored the potential of chitosan/hydroxyapatite (HA) composites to act as a controlled drug delivery system by developing functional scaffolds with a gradient of structure and drug concentration. Firstly, a porous composite scaffold was prepared and tetracycline hydrochloride (TCH) was impregnated in the scaffold as a model drug. The pore size of the scaffold was negatively dependent on the HA content and ranged about 40–250 μm. Subsequently, a porous chitosan/HA composite layer without drug was coated on the scaffold to create a gradient drug concentration in the specimen. The in vitro drug‐release test demonstrated that the porous layer without drug on the outer surface of the scaffold significantly reduced the initial burst of drug release and extended the release period. Finally, a successive and dense chitosan/HA composite layer endowed the scaffold with a sustained, drug‐release pattern without any initial drug burst. These findings confirmed the high effectiveness of the hybrid scaffolds in regulating the release of drugs, and hence their capability to serve as a temporary drug carrier in tissue regeneration. These functional scaffolds also have potential application to the delivery of some bioactive molecules such as growth factors. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Embryonic overexpression of Galgt2 inhibits skeletal muscle growth via activation of myostatin signaling
Authors: Chandraskeharan Kumaran , Martin Paul T.
Published: December 2008

Many proteins that affect skeletal muscle growth are secreted glycoproteins, yet the nature of how glycosylation regulates the expression and growth‐promoting properties of such factors is not well understood. One type of glycosylation that affects muscle growth is that controlled by the CT GalNAc transferase (Galgt2), the enzyme responsible for the synthesis of the β1,4GalNAc linkage on the CT carbohydrate antigen (GalNAcβ1,4[Neu5Ac(or Gc)α2,3]Galβ1,4GlcNAcβ‐R). In the mouse, both Galgt2 protein and the CT carbohydrate become confined to the neuromuscular synapse in skeletal muscle by the second postnatal week. Galgt2 transgenic mice that overexpress the CT carbohydrate from embryonic time‐points onward in skeletal muscle had profoundly impaired muscle growth that was maintained throughout adulthood. Transgenic overexpression of Galgt2 increased myostatin protein expression and stimulated myostatin signaling, whereas expression of follistatin protein, a myostatin inhibitor, was decreased. Changed myostatin and follistatin protein levels were controlled at a posttranslational level, and inhibition of muscle growth was overcome if serum follistatin levels were normalized to wild‐type levels. In contrast to embryonic Galgt2 overexpression, postnatal overexpression of Galgt2 had no effect on either myostatin or follistatin expression or muscle growth. These experiments demonstrate that Galgt2 can control growth by modulating the expression of myostatin and myostatin inhibitors during particular periods of muscle development. © 2009 Wiley Periodicals, Inc. Muscle Nerve 39: 25–41, 2009
A Neumann–Neumann algorithm for a mortar finite element discretization of fourth‐order elliptic problems in 2D
Authors: Marcinkowski Leszek
Published: December 2008

Here we present and analyze a Neumann–Neumann algorithm for the mortar finite element discretization of elliptic fourth‐order problems with discontinuous coefficients. The fully parallel algorithm is analyzed using the abstract Schwarz framework, proving a convergence which is independent of the parameters of the problem, and depends only logarithmically on the ratio between the subdomain size and the mesh size.© 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
N‐Hydroxyphthalimide (NHPI)/lead tetraacetate reactions with cyclic and acyclic alkenes
Authors: Coseri Sergiu
Published: December 2008

The reactions between phthalimide N‐oxyl (PINO) radical and cyclohexene, cyclooctene, and trans‐3‐hexene were carried out. The PINO radical has been in situ generated from its hydroxylimide parent, N‐hydroxyphthalimide (NHPI), applying two approaches: using metallic salts, such as lead tetraacetate and cerium (IV) ammonium nitrate (CAN), and a “metal free” system in which the role of metallic species has been undertaken by antraquinone. In the former case, the strong influence of lead tetraacetate (or CAN) on the NHPI's reactivity, induce two different channels for the reaction pathway, radical and non‐radical, a complex mixture of both saturated and unsaturated diadducts together with the corresponding monoadduct being formed. This behavior will not occur in the case of PINO generation in non‐metallic systems, in this case the reaction pathway proceed exclusively via radical mechanism, with the formation of monoadducts as sole products. Copyright © 2008 John Wiley & Sons, Ltd.
How many peroxyl radicals can be scavenged by hydroxyl‐substituted Schiff bases in the oxidation of linoleic acid?
Authors: Liu Zai‐Qun , Wu Di
Published: December 2008

Eleven hydroxyl‐substituted Schiff bases (SchOHs) were synthesized by the reaction between hydroxyl‐substituted benzaldehydes and hydroxyl‐substituted anilines, and their antioxidant effects on the oxidation of linoleic acid (dissolved in sodium dodecyl sulfate micelle) induced by 2,2′‐azobis(2‐amidinopropane hydrochloride) (AAPH) were investigated. The relationships between the period of the oxidation inhibited by SchOHs (tinh) and their concentrations ([SchOHs]) were measured firstly, and then treated by a chemical kinetic equation, tinh = (n/Ri)[SchOH], to obtain the number (n) of the oxidative chains terminated by one molecule of SchOH. Therefore, the antioxidant activities of SchOHs can be expressed quantitatively by the n value. Finally, the spin‐densities (SD) on O atom in the radical of SchOH (SchO.) were calculated by quantum chemical method, and, to some extent, SD provided an explanation to the difference of the antioxidant effects among various SchOH. Therefore, the obtained results provided an attempt to bridge the kinetic measurement and quantum calculation in the study on the property of an antioxidant. Copyright © 2008 John Wiley & Sons, Ltd.
Herbal medicine for dementia: a systematic review
Authors: May Brian H. , Lit M. , Xue Charlie C. L. , Yang Angela W. H. , Zhang Anthony L. , Owens Michael D. , Head Richard , Cobiac Lynne , Li Chun Guang , Hugel Helmut , Story David F.
Published: December 2008

This systematic review aimed to assess the effectiveness and safety of herbal medicines (HM) for treating dementia. Databases in English and Chinese were searched from their inceptions to February 2007. References in reviews and randomized controlled trials (RCTs) were screened by hand. Trials comparing orally administered HM with placebo, no intervention or other therapy were considered. Trials on Ginkgo biloba and its extracts were excluded to avoid duplication of existing reviews. Pairs of authors independently applied eligibility criteria, extracted data and assessed methodological quality using the Jadad Scale. Thirteen RCTs met the inclusion criteria of three or above on this scale. Six trials compared herbal medicine with placebo, one with no treatment, and the remainder with pharmaceutical intervention. Meta‐analyses were performed on common cognitive performance outcome measures. All studies reported HM had significant effects in improving symptoms. In studies that employed active controls, HM was at least as effective as the pharmaceutical intervention. Meta‐analyses found HM more effective than no treatment or placebo and at least equivalent to control interventions, although the overall effect was small. No severe adverse events were reported. These trials provide overall positive evidence for the effectiveness and safety of certain HMs for dementia management. Copyright © 2008 John Wiley & Sons, Ltd.
Modified myocardial performance index for evaluation of fetal cardiac function in pre‐eclampsia
Authors: Api O. , Emeksiz M. Balcin , Api M. , Uǧurel V. , Unal O.
Published: December 2008

Objective

To assess cardiac function by means of the modified myocardial performance index (Mod‐MPI) in fetuses of pre‐eclamptic mothers without intrauterine growth restriction and to compare this with values from normal controls.

Methods

A cross‐sectional study was conducted including a total of 72 fetuses at between 26 and 40 weeks' gestation. Forty fetuses of healthy mothers were assigned as the control group (Group I) while 15 fetuses of mildly pre‐eclamptic mothers constituted Group II and 17 fetuses of severely pre‐eclamptic mothers constituted Group III. Two‐dimensional gray‐scale and Doppler fetal echocardiography was used to exclude cardiac anomalies and calculate the Mod‐MPI.

Results

The mean ± SD Mod‐MPI values of Groups I, II and III were 0.43 ± 0.045, 0.44 ± 0.064 and 0.44 ± 0.064, respectively (P = 0.680). The mean aortic peak systolic velocity (PSV), the mean mitral valve early ventricular filling (E‐wave) and active atrial filling (A‐wave) peak velocities were significantly lower in fetuses of severely pre‐eclamptic mothers than in fetuses of mildly pre‐eclamptic mothers and control fetuses.

Conclusion

The fetal global myocardial function assessed by Mod‐MPI does not seem to change in mild or severe pre‐eclampsia. The lower mitral E‐wave and A‐wave peak velocities and the lower aortic PSV seem to reflect the increased cardiac afterload against which the fetal heart has to work, rather than systolic or diastolic cardiac dysfunction, in the fetuses of severely pre‐eclamptic mothers. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Effect of BH4 supplementation on phenylalanine tolerance
Authors: Burlina A. , Blau N.
Published: December 2008

Background:

Tetrahydrobiopterin (BH4) is a potential new orphan drug for the treatment of some patients with phenylketonuria (PKU), mostly mild forms. Numerous studies have confirmed this finding and BH4‐responsiveness may be predicted to some extent from the corresponding genotype.

Aim:

To investigate the response to BH4 loading test, the phenylalanine hydroxylase (PAH) mutations and the long‐term therapeutic efficacy of BH4 in patients with PKU, and to better define BH4‐responsive patients according to phenylalanine (Phe) levels and dietary phenylalanine tolerance.

Methods:

30 Italian PKU patients (age range: 6 months–24 years; 12 female, 18 male) were included in this retrospective study. Eleven out of 30 patients presented with Phe levels below 450 μmol/L and 19 patients with Phe levels between 450 and 900 μmol/L. In the second group, we investigated the effect of long‐term (6 months–7 years) oral administration of BH4 on blood Phe levels and daily Phe tolerance.

Results:

In all patients with initial blood Phe levels <450 μmol/L (n = 11), BH4 loading test was positive, but no treatment was introduced. In 12 out of 19 patients with blood Phe levels >450 μmol/L and positive at BH4 loading, the treatment with BH4 (10 mg/kg per day) was initiated. Before BH4 treatment, Phe tolerance was less than 700 mg/day in all patients except for one (patient no. 9), increasing to 2–3‐fold (from 498 ± 49 to 1475 ± 155 mg/day) on BH4 treatment. In these patients the amino acid mixture supplementation was stopped and the diet was a combination of low‐protein foods and natural proteins, mostly from animal sources.

Conclusion:

Long‐term BH4 substitution (up to 7 years) in a group of moderate PKU patients allowed a substantial relaxation of the dietary restrictions or even replacement of the diet with BH4 without any adverse effects.
Long‐standing mild hypertransaminasaemia caused by congenital disorder of glycosylation (CDG) type IIx
Authors: Calvo P. L. , Pagliardini S. , Baldi M. , Pucci A. , Sturiale L. , Garozzo D. , Vinciguerra T. , Barbera C. , Jaeken J.
Published: December 2008

A 32 year‐old asymptomatic male came to our attention with a 21‐year history, documented elsewhere, of puzzling increases in his serum transaminase level. At first, very low serum ceruloplasmin level suggested Wilson disease. Two liver biopsies showed mild portal inflammation, steatosis and mild fibrosis. Further investigation revealed low levels of the glycoproteins AT III and clotting factor XI, leading to a diagnosis of congenital disorder of glycosylation (CDG) type II. Further studies as to the cause of this ‘apparently new’ CDG, are ongoing. On the basis of our data and a literature review, we suggest that subjects with asymptomatic hypertransaminasaemia be screened for CDG.
Vulnerability to strong winds for major tree species in a northern Japanese mixed forest: analyses of historical data
Authors: Yoshida Toshiya , Noguchi Mahoko
Published: December 2008

This study examined historical census data to evaluate the vulnerability of major tall‐tree species in northern Japan to strong winds. Intensive data, which measured more than 20,000 damaged trees (defined as trees that were killed or lost their major crown) in >500 ha of a natural mixed forest, were collected immediately after a severe typhoon in 1954. More than half of the damaged trees had been uprooted, and the negative size‐dependency was found for the proportion of uprooting throughout species. Simple correlation analyses with respect to the averaged species‐specific characteristics suggested that tree species with a high crown‐depth/height tended to uproot (against to stem breakage) in a size‐class with diameter at breast height 30–50 cm. Although the census data had yielded no information about non‐damaged trees, the estimation of pre‐disturbed stand (based on 63 1‐ha plot data together with aerial photographs and GIS) revealed that the observed damage reached ca. 25% in terms of basal area. The proportion of damaged trees seemed to be doubled among species (15–42% in basal area). A higher proportion of uprooting, which indicates a large supply of tip‐up mounds, and mixture of less vulnerable species, might contribute to recovery process after a wind disturbance in this type of mixed forests.
Towards automatic near real-time traffic monitoring with an airborne wide angle camera system
Authors: Rosenbaum Dominik , Kurz Franz , Thomas Ulrike , Suri Sahil , Reinartz Peter
Published: December 2008

Purpose

Large area traffic monitoring with high spatial and temporal resolution is a challenge that cannot be served by today available static infrastructure. Therefore, we present an automatic near real-time traffic monitoring approach using data of an airborne digital camera system with a frame rate of up to 3 fps.

Methods

By performing direct georeferencing on the obtained aerial images with the use of GPS/IMU data we are able to conduct near real-time traffic data extraction. The traffic processor consists mainly of three steps which are road extraction supported by a priori knowledge of road axes obtained from a road database, vehicle detection by edge extraction, and vehicle tracking based on normalized cross correlation.

Results

Traffic data is obtained with a correctness of up to 79% at a completeness of 68%.

Conclusions

With this system we are able to perform area-wide traffic monitoring with high actuality independent from any stationed infrastructure which makes the system well suited for deployments on demand in case of disasters and mass events.
Ovine colostrum nanopeptide affects amyloid beta aggregation
Authors: Janusz Maria , Woszczyna Mirosław , Lisowski Marek , Kubis Adriana , Macała Józefa , Gotszalk Teodor , Lisowski Józef
Published: December 2008

A colostral proline‐rich polypeptide complex (PRP) consisting of over 30 peptides shows beneficial effects in Alzheimer's disease (AD) patients when administered in the form of sublinqual tablets called Colostrinin. The aim of the present studies was to investigate whether nanopeptide fragment of PRP (NP) – one of the PRP complex components can affect aggregation of amyloid β (Aβ1‐42). The effect of NP on Aβ aggregation was studied using Thioflavin T (ThT) binding, atomic force microscopy, and analyzing circular dichroism spectra. Results presented suggest that NP can directly interact with amyloid beta, inhibit its aggregation and disrupt existing aggregates acting as a β sheet breaker and reduce toxicity induced by aggregated forms of Aβ.
Cervical intraepithelial neoplasia recurrence after conization in HIV‐positive and HIV‐negative women
Authors: Lima Maria Inês , Tafuri Alexandre , Araújo Angela C , de Miranda Lima Luiza , Melo Victor Hugo
Published: December 2008

Objectives

To evaluate the recurrence rates of cervical intraepithelial neoplasia (CIN) in a cohort of HIV‐infected and noninfected women who underwent the loop electrosurgical excision procedure (LEEP).

Methods

A prospective cohort study of 94 HIV‐positive and 107 HIV‐negative women, both with CIN, treated with LEEP. The diagnosis of recurrence was established after biopsy. The Kaplan‐Meier method was used for survival analysis and multivariate analyses were carried out using the Cox proportional hazards regression model.

Results

There was a predominance of low‐grade lesions in HIV‐positive compared with HIV‐negative women (P < 0.01). Recurrence was more frequent with compromised margins and glandular involvement (P < 0.01). A multivariate analysis showed that HIV‐infection, glandular involvement, and positive margins were independently associated with recurrence of lesions.

Conclusions

Recurrence rate of CIN in HIV‐positive women was higher than in HIV‐negative women. The factors associated with recurrence were HIV infection, glandular involvement, and positive margins.
Gonadotropin‐releasing hormone analog combined with a low‐dose oral contraceptive to treat heavy menstrual bleeding
Authors: Cetin Nadire N. , Karabacak Onur , Korucuoglu Umit , Karabacak Nese
Published: December 2008

Objective

To compare the effects of low‐dose oral contraceptives used alone and in combination with a gonadotropin‐releasing hormone (GnRH) analog to treat heavy menstrual bleeding.

Methods

Fifty‐eight patients with heavy menstrual bleeding were prospectively randomized into two treatment groups to receive either a low‐dose oral contraceptive alone (group 1), or combined with a GnRH analog (group 2) for 6 months. The patients' hormonal profiles, and hemoglobin and hematocrit levels were measured at the beginning and at the end of the treatment period.

Results

Hemoglobin and hematocrit levels significantly improved in both groups after 6 months of treatment (P < 0.05 and P < 0.01, respectively). Even in the first month of the study, the number of pads used and the duration of menstruation were significantly decreased in both groups and markedly lower in group 2 (P < 0.01).

Conclusion

The addition of a GnRH analog to low‐dose oral contraceptive treatment for heavy menstrual bleeding resulted in better control of vaginal bleeding, even in the first month of therapy.
Urinary cortisol/cortisone ratios in hypertensive and normotensive cats
Authors: Walker David J. , Elliott Jonathan , Syme Harriet M.
Published: December 2008

Hypertension is a common problem in older cats, particularly associated with chronic kidney disease (CKD). Reduced activity of 11β-hydroxysteroid dehydrogenase type 2 predisposes to hypertension in human patients by allowing excessive stimulation of the mineralocorticoid receptor by cortisol. This study was designed to test the hypothesis that reduced conversion of cortisol to cortisone contributes to the development of systemic hypertension in some cats with CKD and idiopathic hypertension (iHT). The study included 60 client-owned cats: 21 clinically normal, 16 normotensive cats with CKD (NTCKD), 14 hypertensive cats with CKD (HTCKD) and nine iHTs. Urine cortisol and cortisone were extracted into dichloromethane and chloroform, respectively, prior to analysis by radioimmunoassay. Data are reported as median and range. The Kruskall–Wallis test was used to compare cortisol:cortisone ratios between groups with post-hoc testing using the Mann–Whitney U test. Wilcoxon signed-ranks test was used to compare results before and after treatment of hypertensive cats with amlodipine. The urinary cortisol:cortisone ratio was significantly higher in clinically normal cats (0.87; 0.46–1.39) when compared to NTCKD (0.60; 0.35–1.20; P<0.001), HTCKD (0.62; 0.34–1.00; P=0.002) and cats with iHT (0.65; 0.46–0.85; P=0.015). No statistical difference was detected between NTCKD, HTCKD and iHT groups. No effect of anti-hypertensive treatment on the urinary cortisol–cortisone ratio was detected ( P=0.327). Reduced urinary cortisol to cortisone conversion does not appear to be associated with systemic hypertension in cats. In fact, the cortisol to cortisone shuttle appears to be more effective in cats with CKD (hypertensive and normotensive) and iHT than clinically normal cats. The mechanism for this potentially adaptive response to kidney disease is not clear.
Pathological abnormalities after long-term administration of medroxyprogesterone acetate in a queen
Authors: Keskin Abdulkadir , Yilmazbas Gulnaz , Yilmaz Rahsan , Ozyigit Musa O. , Gumen Ahmet
Published: December 2008

In this report, multiple abnormalities (bilateral ovarian cysts, cystic endometrial hyperplasia and pyometra (CEH–P), mammary adenoma, fibrosarcoma and cystic-papillary adenocarcinoma) identified in a queen continually administered medroxyprogesterone acetate (MPA) for 9 years are described. An 11-year-old domestic shorthair intact queen was presented for reduced appetite, polyuria, polydipsia, abdominal distension, and mammary mass. Pyometra was diagnosed based upon clinical, ultrasonographic and radiographic examinations. Mastectomy and ovariohysterectomy (OHE) were performed for treatment. Bilateral ovarian cysts were detected during OHE. Histopathologically, follicular ovarian cysts, CEH–P, and benign and neoplastic mammary lesions were identified. We suggest that, the pathological abnormalities may have been attributed to adverse effects of prolonged administration of MPA.
Deregulation, privatisation and public service delivery: Universal service in telecommunications in Europe
Authors: Eliassen Kjell A , From Johan
Published: December 2008

This paper argues that the re-emergence of a universal service debate is a political reaction to the deregulation process and an attempt to force the role of the state and public services higher on the agenda at EU level. To this end, the concepts of ‘service public’ and ‘public services’ are explored in light of telecommunication deregulation and public service provision as expressed by the universal service obligation (USO) in France, Great Britain, Belgium and Norway. Attention is paid to the importance of securing general access to telecommunications. Findings suggest the legitimating effect of USO is greater than its practical effects, and that market, competition, and technology have largely addressed problems with universal access, equality, continuity and affordability, rather than regulations. Further, future regulations of universal service provision and ‘service public’ requirements will need to address concerns over citizens’ dislike of some effects of regional and national deregulation and liberalisation policies.
Postal reform around the globe: Comparing the Asian and European experience
Authors: Eckert Sandra
Published: December 2008

Postal reform has become a global trend in the age of liberalisation and privatisation. At the same time, change in this politically entrenched policy field meets with domestic resistance. This article sheds light on the politics of reform and regulation in four European and Asian countries. It is found that reform trajectories are far from being uniform and so are the emerging regulatory regimes: in view of domestic resistance France engaged in minimal change which was exclusively driven by European Union (EU) pressure; Germany initially introduced far-reaching measures, but for political motives deviated from this reform path over time; in Japan postal reform has been a side-effect of restructuring the country’s financial and banking sector, running short of introducing a regulatory framework which would effectively open up the market to competition; the preconditions for change were most favourable in Singapore, yet remaining bottlenecks may prevent that full liberalisation lives up to reality.
The failure of water utilities privatization: Synthesis of evidence, analysis and implications
Authors: Araral Eduardo
Published: December 2008

During much of the 1990s, water utilities worldwide experienced a wave of privatization. The rationale for this is largely based on two hypotheses: the fiscal hypothesis and the efficiency hypothesis. This article examines the evidence and concludes that water utilities privatization has been a failure.
Short-time self-diffusion of nearly hard spheres at an oil–water interface
Authors: PENG Y. , CHEN W. , FISCHER TH. M. , WEITZ D. A. , TONG P.
Published: December 2008

Optical microscopy and multi-particle tracking are used to study hydrodynamic interactions of monodisperse polymethylmethacrylate (PMMA) spheres at a decalin–water interface. The short-time self-diffusion coefficient measured at low surface coverage has the formDSS(n) = αD0(1 − βn), wherenis the area fraction occupied by the particles, andD0is the Stokes–Einstein diffusion coefficient in the bulk suspension of PMMA spheres in decalin. The measured values of α are found to be in good agreement with the numerical calculation for the drag coefficient of interfacial particles. The measured values of β differ from that obtained for bulk suspensions, indicating that hydrodynamic interactions between the particles have interesting new features at the interface.
Motion on upper‐plate faults during subduction zone earthquakes: Case of the Atacama Fault System, northern Chile
Authors: Loveless J. P. , Pritchard M. E.
Published: December 2008

Motion on the Atacama Fault System (AFS) in northern Chile is driven by Andean subduction zone processes. We use two approaches, observational and theoretical, to evaluate how the AFS and other forearc faults responded to coseismic stress induced by one well‐studied megathrust earthquake, the 1995 Mw = 8.1 Antofagasta event. We use synthetic aperture radar interferometry (InSAR) to search for small‐scale coseismic and postseismic deformation on individual faults. The InSAR data are ambiguous: some images show offset consistent with coseismic faulting on the Paposo segment of the AFS and others lack such signal. The fact that we do not observe the fault‐like displacement in all coseismic interferograms suggests that atmospheric contamination, not tectonic deformation, is responsible for the signal. To explore the capacity of the earthquake to trigger motion on upper plate faults, we use seven published slip maps constrained by geodetic and/or seismic data to calculate static and dynamic Coulomb stress change (CSC) on faults in the Antofagasta region. The static CSC field varies between models and depends on the distribution of coseismic interplate slip. On the basis of the CSC distribution predicted by our preferred model constrained by all available data, we suggest it was unlikely that the Antofagasta earthquake directly triggered normal motion on the AFS, and the InSAR data are consistent with this null result. Field reports of normal faulting related to the earthquake may reflect recent (but not coseismic) motion or highly localized behavior not representative of the regional coseismic stress field.
Flood trends and river engineering on the Mississippi River system
Authors: Pinter Nicholas , Jemberie Abebe A. , Remo Jonathan W. F. , Heine Reuben A. , Ickes Brian S.
Published: December 2008

Along >4000 km of the Mississippi River system, we document that climate, land‐use change, and river engineering have contributed to statistically significant increases in flooding over the past 100–150 years. Trends were tested using a database of >8 million hydrological measurements. A geospatial database of historical engineering construction was used to quantify the response of flood levels to each unit of engineering infrastructure. Significant climate‐ and/or land use‐driven increases in flow were detected, but the largest and most pervasive contributors to increased flooding on the Mississippi River system were wing dikes and related navigational structures, followed by progressive levee construction. In the area of the 2008 Upper Mississippi flood, for example, about 2 m of the flood crest is linked to navigational and flood‐control engineering. Systemwide, large increases in flood levels were documented at locations and at times of wing‐dike and levee construction.
Electronic structure of the organic semiconductor Alq3 (aluminum tris-8-hydroxyquinoline) from soft x-ray spectroscopies and density functional theory calculations
Authors: DeMasi A. , Piper L. F. J. , Zhang Y. , Reid I. , Wang S. , Smith K. E. , Downes J. E. , Peltekis N. , McGuinness C. , Matsuura A.
Published: December 2008

The element-specific electronic structure of the organic semiconductor aluminum tris-8-hydroxyquinoline (Alq3) has been studied using a combination of resonant x-ray emission spectroscopy, x-ray photoelectron spectroscopy, x-ray absorption spectroscopy, and density functional theory (DFT) calculations. Resonant and nonresonant x-ray emission spectroscopy were used to measure directly the carbon, nitrogen and oxygen 2p partial densities of states in Alq3, and good agreement was found with the results of DFT calculations. Furthermore, resonant x-ray emission at the carbon K-edge is shown to be able to measure the partial density of states associated with individual C sites. Finally, comparison of previous x-ray emission studies and the present data reveal the presence of clear photon-induced damage in the former.
Wave propagation and tunneling through periodic structures
Authors: Konoplev I. V. , MacInnes P. , Cross A. W. , Phelps A. D. R. , Fisher L. , Ronald K.
Published: December 2008

The phenomenon of tunneling manifests itself in nearly every field of physics. The ability to distinguish a wave tunneling through a barrier from one propagating is important for a number of applications. Here we explore the properties of the wave traveling through the band gap created by a lattice, either as a consequence of tunneling through the barrier or due to the presence of a pass band inside the gap. To observe the pass band for studying tunneling and propagating waves simultaneously, a localized lattice defect was introduced. The differences between the two phenomena are highlighted via waves’ dispersion characteristics.
An analytic study of the perpendicularly propagating electromagnetic drift instabilities in the Magnetic Reconnection Experiment
Authors: Wang Yansong , Kulsrud Russell , Ji Hantao
Published: December 2008

A local linear theory is proposed for a perpendicularly propagating drift instability driven by relative drifts between electrons and ions. The theory takes into account local cross-field current, pressure gradients, and modest collisions as in the Magnetic Reconnection Experiment [M. Yamada et al., Phys. Plasmas 4, 1936 (1997)]. The unstable waves have very small group velocities in the direction of the pressure gradient, but have a large phase velocity near the relative drift velocity between electrons and ions in the direction of the cross-field current. By taking into account the electron-ion collisions and applying the theory in the Harris sheet, we establish that this instability could be excited near the center of the Harris sheet and have enough e-foldings to grow to large amplitude before it propagates out of the unstable region. Comparing with the other magnetic reconnection related instabilities (lower-hybrid-drift instability, modified two-stream instability, etc.) studied previously, we believe the instability we found is a favorable candidate to produce anomalous resistivity because of its unique wave characteristics, such as electromagnetic component, large phase velocity, and small group velocity in the cross-current-layer direction.
Low temperature diffusion length of excitons in gallium nitride measured by cathodoluminescence technique
Authors: Ino Naoyuki , Yamamoto Naoki
Published: December 2008

Monochromatic cathodoluminescence (CL) images of threading dislocations in GaN epitaxial layers were observed using a transmission electron microscopy combined with CL system. The carrier diffusion lengths were derived from the free exciton emission intensity profile of the dislocation contrast in the CL images. The carrier diffusion lengths in Si-doped and Mg-doped GaN were nearly the same and shorter than that in undoped GaN in the temperature range from 20 to 140 K, respectively. Moreover, the temperature dependence of the diffusion length shows that the acoustic phonon scattering mainly affects the exciton diffusion process at low temperatures from 40 to 120 K.
El Niño/Southern Oscillation response to global warming
Authors: Latif M. , Keenlyside N. S.
Published: December 2008

The El Niño/Southern Oscillation (ENSO) phenomenon, originating in the Tropical Pacific, is the strongest natural interannual climate signal and has widespread effects on the global climate system and the ecology of the Tropical Pacific. Any strong change in ENSO statistics will therefore have serious climatic and ecological consequences. Most global climate models do simulate ENSO, although large biases exist with respect to its characteristics. The ENSO response to global warming differs strongly from model to model and is thus highly uncertain. Some models simulate an increase in ENSO amplitude, others a decrease, and others virtually no change. Extremely strong changes constituting tipping point behavior are not simulated by any of the models. Nevertheless, some interesting changes in ENSO dynamics can be inferred from observations and model integrations. Although no tipping point behavior is envisaged in the physical climate system, smooth transitions in it may give rise to tipping point behavior in the biological, chemical, and even socioeconomic systems. For example, the simulated weakening of the Pacific zonal sea surface temperature gradient in the Hadley Centre model (with dynamic vegetation included) caused rapid Amazon forest die-back in the mid-twenty-first century, which in turn drove a nonlinear increase in atmospheric CO
2
, accelerating global warming.
A movement ecology paradigm for unifying organismal movement research
Authors: Nathan Ran , Getz Wayne M. , Revilla Eloy , Holyoak Marcel , Kadmon Ronen , Saltz David , Smouse Peter E.
Published: December 2008

Movement of individual organisms is fundamental to life, quilting our planet in a rich tapestry of phenomena with diverse implications for ecosystems and humans. Movement research is both plentiful and insightful, and recent methodological advances facilitate obtaining a detailed view of individual movement. Yet, we lack a general unifying paradigm, derived from first principles, which can place movement studies within a common context and advance the development of a mature scientific discipline. This introductory article to the Movement Ecology Special Feature proposes a paradigm that integrates conceptual, theoretical, methodological, and empirical frameworks for studying movement of all organisms, from microbes to trees to elephants. We introduce a conceptual framework depicting the interplay among four basic mechanistic components of organismal movement: the internal state (why move?), motion (how to move?), and navigation (when and where to move?) capacities of the individual and the external factors affecting movement. We demonstrate how the proposed framework aids the study of various taxa and movement types; promotes the formulation of hypotheses about movement; and complements existing biomechanical, cognitive, random, and optimality paradigms of movement. The proposed framework integrates eclectic research on movement into a structured paradigm and aims at providing a basis for hypothesis generation and a vehicle facilitating the understanding of the causes, mechanisms, and spatiotemporal patterns of movement and their role in various ecological and evolutionary processes.

”Now we must consider in general the common reason for moving with any movement whatever.“ (Aristotle,De Motu Animalium, 4th century B.C.)
Trends and missing parts in the study of movement ecology
Authors: Holyoak Marcel , Casagrandi Renato , Nathan Ran , Revilla Eloy , Spiegel Orr
Published: December 2008

Movement is important to all organisms, and accordingly it is addressed in a huge number of papers in the literature. Of nearly 26,000 papers referring to movement, an estimated 34% focused on movement by measuring it or testing hypotheses about it. This enormous amount of information is difficult to review and highlights the need to assess the collective completeness of movement studies and identify gaps. We surveyed 1,000 randomly selected papers from 496 journals and compared the facets of movement studied with a suggested framework for movement ecology, consisting of internal state (motivation, physiology), motion and navigation capacities, and external factors (both the physical environment and living organisms), and links among these components. Most studies simply measured and described the movement of organisms without reference to ecological or internal factors, and the most frequently studied part of the framework was the link between external factors and motion capacity. Few studies looked at the effects on movement of navigation capacity, or internal state, and those were mainly from vertebrates. For invertebrates and plants most studies were at the population level, whereas more vertebrate studies were conducted at the individual level. Consideration of only population-level averages promulgates neglect of between-individual variation in movement, potentially hindering the study of factors controlling movement. Terminology was found to be inconsistent among taxa and subdisciplines. The gaps identified in coverage of movement studies highlight research areas that should be addressed to fully understand the ecology of movement.
Individual movement behavior, matrix heterogeneity, and the dynamics of spatially structured populations
Authors: Revilla Eloy , Wiegand Thorsten
Published: December 2008

The dynamics of spatially structured populations is characterized by within- and between-patch processes. The available theory describes the latter with simple distance-dependent functions that depend on landscape properties such as interpatch distance or patch size. Despite its potential role, we lack a good mechanistic understanding of how the movement of individuals between patches affects the dynamics of these populations. We used the theoretical framework provided by movement ecology to make a direct representation of the processes determining how individuals connect local populations in a spatially structured population of Iberian lynx. Interpatch processes depended on the heterogeneity of the matrix where patches are embedded and the parameters defining individual movement behavior. They were also very sensitive to the dynamic demographic variables limiting the time moving, the within-patch dynamics of available settlement sites (both spatiotemporally heterogeneous) and the response of individuals to the perceived risk while moving. These context-dependent dynamic factors are an inherent part of the movement process, producing connectivities and dispersal kernels whose variability is affected by other demographic processes. Mechanistic representations of interpatch movements, such as the one provided by the movement-ecology framework, permit the dynamic interaction of birth–death processes and individual movement behavior, thus improving our understanding of stochastic spatially structured populations.
A framework for generating and analyzing movement paths on ecological landscapes
Authors: Getz Wayne M. , Saltz David
Published: December 2008

The movement paths of individuals over landscapes are basically represented by sequences of points (

x
i

,

y
i

) occurring at times

t
i

. Theoretically, these points can be viewed as being generated by stochastic processes that in the simplest cases are Gaussian random walks on featureless landscapes. Generalizations have been made of walks that (
i
) take place on landscapes with features, (
ii
) have correlated distributions of velocity and direction of movement in each time interval, (
iii
) are Lévy processes in which distance or waiting-time (time-between steps) distributions have infinite moments, or (
iv
) have paths bounded in space and time. We begin by demonstrating that rather mild truncations of fat-tailed step-size distributions have a dramatic effect on dispersion of organisms, where such truncations naturally arise in real walks of organisms bounded by space and, more generally, influenced by the interactions of physiological, behavioral, and ecological factors with landscape features. These generalizations permit not only increased realism and hence greater accuracy in constructing movement pathways, but also provide a biogeographically detailed epistemological framework for interpreting movement patterns in all organisms, whether tossed in the wind or willfully driven. We illustrate the utility of our framework by demonstrating how fission–fusion herding behavior arises among individuals endeavoring to satisfy both nutritional and safety demands in heterogeneous environments. We conclude with a brief discussion of potential methods that can be used to solve the inverse problem of identifying putative causal factors driving movement behavior on known landscapes, leaving details to references in the literature.
Multiple movement modes by large herbivores at multiple spatiotemporal scales
Authors: Fryxell John M. , Hazell Megan , Börger Luca , Dalziel Ben D. , Haydon Daniel T. , Morales Juan M. , McIntosh Therese , Rosatte Rick C.
Published: December 2008

Recent theory suggests that animals should switch facultatively among canonical movement modes as a complex function of internal state, landscape characteristics, motion capacity, and navigational capacity. We tested the generality of this paradigm for free-ranging elk (
Cervus elaphus
) over 5 orders of magnitude in time (minutes to years) and space (meters to 100 km). At the coarsest spatiotemporal scale, elk shifted from a dispersive to a home-ranging phase over the course of 1–3 years after introduction into a novel environment. At intermediate spatiotemporal scales, elk continued to alternate between movement modes. During the dispersive phase, elk alternated between encamped and exploratory modes, possibly linked to changes in motivational goals from foraging to social bonding. During the home-ranging phase, elk movements were characterized by a complex interplay between attraction to preferred habitat types and memory of previous movements across the home-range. At the finest temporal and spatial scale, elk used area-restricted search while browsing, interspersed with less sinuous paths when not browsing. Encountering a patch of high-quality food plants triggered the switch from one mode to the next, creating biphasic movement dynamics that were reinforced by local resource heterogeneity. These patterns suggest that multiphasic structure is fundamental to the movement patterns of elk at all temporal and spatial scales tested.