bluuebunny/crossref_metadata_2025 huggingface dataset:
Partial fourier reconstruction through data fitting and convolution in k‐space
Authors: Huang Feng , Lin Wei , Li Yu
Published: September 2009

A partial Fourier acquisition scheme has been widely adopted for fast imaging. There are two problems associated with the existing techniques. First, the majority of the existing techniques demodulate the phase information and cannot provide improved phase information over zero‐padding. Second, serious artifacts can be observed in reconstruction when the phase changes rapidly because the low‐resolution phase estimate in the image space is prone to error. To tackle these two problems, a novel and robust method is introduced for partial Fourier reconstruction, using k‐space convolution. In this method, the phase information is implicitly estimated in k‐space through data fitting; the approximated phase information is applied to recover the unacquired k‐space data through Hermitian operation and convolution in k‐space. In both spin echo and gradient echo imaging experiments, the proposed method consistently produced images with the lowest error level when compared to Cuppen's algorithm, projection onto convex sets–based iterative algorithm, and Homodyne algorithm. Significant improvements are observed in images with rapid phase change. Besides the improvement on magnitude, the phase map of the images reconstructed by the proposed method also has significantly lower error level than conventional methods. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Motion correction of single‐voxel spectroscopy by independent component analysis applied to spectra from nonanesthetized pediatric subjects
Authors: de Nijs Robin , Miranda Maria J. , Hansen Lars Kai , Hanson Lars G.
Published: September 2009

For single‐voxel spectroscopy, the acquisition of the spectrum is typically repeatedntimes and then combined with a factor$\sqrt{n}$in order to improve the signal‐to‐noise ratio. In practice, the acquisitions are not only affected by random noise but also by physiologic motion and subject movements. Since the influence of physiologic motion such as cardiac and respiratory motion on the data is limited, it can be compensated for without data loss. Individual acquisitions hampered by subject movements, on the other hand, need to be rejected if no correction or compensation is possible. If the individual acquisitions are stored, it is possible to identify and reject the motion‐disturbed acquisitions before averaging. Several automatic algorithms were investigated using a dataset of spectra from nonanesthetized infants with a gestational age of 40 weeks. Median filtering removed most subject movement artifacts, but at the cost of increased sensitivity to random noise. Neither independent component analysis nor outlier identification with multiple comparisons has this problem. These two algorithms are novel in this context. The peak height values of the metabolites were increased compared to the mean of all acquisitions for both methods, although primarily for the ICA method. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Optimized MRI contrast for on‐resonance proton exchange processes of PARACEST agents in biological systems
Authors: Li Alex X. , Suchy Mojmir , Jones Craig K. , Hudson Robert H. E. , Menon Ravi S. , Bartha Robert
Published: September 2009

Image contrast associated with paramagnetic chemical exchange saturation transfer agents can be generated by off‐resonance irradiation of agent‐bound water or amide protons or on‐resonance irradiation of bulk water. Previously, a four‐pool model was developed to describe an in vivo system. The model incorporated the magnetization transfer effect from macromolecules when using off‐resonance irradiation. In the current study, this four‐pool model is modified to describe the in vivo system when using on‐resonance irradiation. The influences of pulse power, pulse duration, the chemical shift of bound water, the proton exchange rate between bulk water and bound water, and agent concentration on the on‐resonance paramagnetic agent chemical exchange effects were simulated using a WALTZ‐16 pulse train in the absence and presence of the macromolecule pool. The results demonstrated that while contrast increases with pulse duration in aqueous solution, there is an optimal pulse duration that maximizes on‐resonance paramagnetic agent chemical exchange effects contrast in vivo. This predication was verified by experimental spectroscopic and imaging results from aqueous solution, bovine serum albumin phantoms, and a tissue phantom containing thulium‐DOTAM (1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetamide)‐glycine‐lysine. This model can be used to optimize sequence parameters to maximize in vivo on‐resonance paramagnetic agent chemical exchange effects contrast. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Proton MRS detects metabolic changes in hormone sensitive and resistant human prostate cancer models CWR22 and CWR22r
Authors: Le H. Carl , Lupu Mihaela , Kotedia Khushali , Rosen Neal , Solit David , Koutcher Jason A.
Published: September 2009

17‐Allylamino, 17‐demethoxygeldanamycin (17‐AAG), an effective inhibitor of the heat shock protein hsp90, preferentially inhibiting tumor hsp90 compared to hsp90 from normal cells, has shown promising results against several cancers, including hormone‐resistant prostate cancer. Levels of several oncogenic proteins critical to tumor growth and progression, such as androgen receptor and HER2/neu, were reduced 4 h post 17‐allylamino, 17‐demethoxygeldanamycin treatment. Posttreatment metabolic changes have also been observed in several tumor cell lines. In this study, total choline distributions in hormone sensitive CWR22 and hormone resistant CWR22r prostate cancer xenograft tumors in mice were measured before and at 4 h and 48 h after a single‐bolus 17‐allylamino, 17‐demethoxygeldanamycin treatment at 100 mg/kg, using proton MR spectroscopy. Our results show that tumor total choline levels declined 4 h after the treatment for CWR22 (P = 0.001) and 48 h post treatment for CWR22r (P = 0.003). Metabolic changes, in particular of total choline intensity detected by proton magnetic resonance spectroscopic imaging (MRSI), are consistent with the observed immunohistochemistry changes, tumor growth inhibition for CWR22r (P = 0.01 at 14 days post treatment), and a constant prostate specific antigen level versus increasing prostate specific antigen for control CWR22 (P = 0.01). Metabolic changes in total choline by proton MRSI can be used as an early biomarker of response for advanced‐stage prostate cancer in targeted therapy such as 17‐allylamino, 17‐demethoxygeldanamycin. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
4D retrospective black blood trueFISP imaging of mouse heart
Authors: Miraux Sylvain , Calmettes Guillaume , Massot Philippe , Lefrançois William , Parzy Elodie , Muller Bernard , Arsac Laurent M. , Deschodt‐Arsac Véronique , Franconi Jean‐Michel , Diolez Philippe , Thiaudière Eric
Published: September 2009

The purpose of this study was to demonstrate the feasibility of steady‐state True fast imaging with steady precession (TrueFISP) four‐dimensional imaging of mouse heart at high resolution and its efficiency for cardiac volumetry. Three‐dimensional cine‐imaging of control and hypoxic mice was carried out at 4.7 T without magnetization preparation or ECG‐triggering. The k‐space lines were acquired with the TrueFISP sequence (pulse repetition time/echo time = 4/2 ms) in a repeated sequential manner. Retrospective reordering of raw data allowed the reconstruction of 10 three‐dimensional images per cardiac cycle. The acquisition scheme used an alternating radiofrequency phase and sum‐of‐square reconstruction method. Black‐blood three‐dimensional images at around 200 μm resolution were produced without banding artifact throughout the cardiac cycle. High contrast to noise made it possible to estimate cavity volumes during diastole and systole. Right and left ventricular stroke volume was significantly higher in hypoxic mice vs controls (20.2 ± 2 vs 15.1 ± 2; P < 0.05, 24.9 ± 2 vs 20.4 ± 2; P < 0.05, respectively). In conclusion, four‐dimensional black‐blood TrueFISP imaging in living mice is a method of choice to investigate cardiac abnormalities in mouse models. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Split gradient coils for simultaneous PET‐MRI
Authors: Poole Michael , Bowtell Richard , Green Dan , Pittard Simon , Lucas Alun , Hawkes Rob , Carpenter Adrian
Published: September 2009

Combining positron emission tomography (PET) and MRI necessarily involves an engineering tradeoff as the equipment needed for the two modalities vies for the space closest to the region where the signals originate. In one recently described scanner configuration for simultaneous positron emission tomography–MRI, the positron emission tomography detection scintillating crystals reside in an 80‐mm gap between the 2 halves of a 1‐T split‐magnet cryostat. A novel set of gradient and shim coils has been specially designed for this split MRI scanner to include an 110‐mm gap from which wires are excluded so as not to interfere with positron detection. An inverse boundary element method was necessarily employed to design the three orthogonal, shielded gradient coils and shielded Z0 shim coil. The coils have been constructed and tested in the hybrid positron emission tomography‐MRI system and successfully used in simultaneous positron emission tomography‐MRI experiments. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Inactive Wnt/β‐catenin pathway in conventional high‐grade osteosarcoma
Authors: Cai Yongping , Mohseny Alexander B , Karperien Marcel , Hogendoorn Pancras CW , Zhou Gengyin , Cleton‐Jansen Anne‐Marie
Published: September 2009

Osteosarcoma is the most common malignant bone tumour, with a peak incidence in children and young adolescents, suggesting a role of rapid bone growth in its pathogenesis. The Wnt/β‐catenin pathway plays a crucial role in skeletal development and is indispensable for osteoblasts' lineage determination. Previous studies suggesting an oncogenic role for the Wnt/β‐catenin pathway in osteosarcoma were based on cytoplasmic staining of β‐catenin or the detection of one component of this pathway. However, those approaches are inappropriate to address whether the Wnt/β‐catenin pathway is functionally active. Therefore, in this study, we examined nuclear β‐catenin expression in 52 human osteosarcoma biopsies, 15 osteoblastomas (benign bone tumours), and four human osteosarcoma cell lines by immunohistochemistry. Furthermore, we modulated Wnt/β‐catenin pathway activity using a GIN (GSK3β inhibitor) and evaluated its effect on cell growth and osteogenic differentiation. Absence of nuclear β‐catenin staining was found in 90% of the biopsies and all osteosarcoma cell lines, whereas strong nuclear β‐catenin staining was observed in all osteoblastomas. Wnt‐luciferase activity was comparable to the negative control in all osteosarcoma cell lines. GIN stimulated the Wnt/β‐catenin pathway, as shown by translocation of β‐catenin into the nucleus and increased Wnt‐luciferase activity as well as mRNA expression of AXIN2, a specific downstream target gene. Stimulation of the Wnt/β‐catenin pathway by GIN significantly reduced cell proliferation in the cell lines MG‐63 and U‐2‐OS and enhanced differentiation in the cell lines HOS and SJSA‐1, as shown by an increase in alkaline phosphatase (ALP) activity and mineralization. In contrast with the oncogenic role of the Wnt/β‐catenin pathway in osteosarcoma as previous studies suggested, here we demonstrate that this pathway is inactivated in osteosarcoma. Moreover, activation of the Wnt/β‐catenin pathway inhibits cell proliferation or promotes osteogenic differentiation in osteosarcoma cell lines. Our data suggest that loss of Wnt/β‐catenin pathway activity, which is required for osteoblast differentiation, may contribute to osteosarcoma development. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Polymorphic and miscibility behavior in crystalline/crystalline blends of poly(pentamethylene terephthalate) with poly(heptamethylene terephthalate)
Authors: Yen Kai Cheng , Woo Eamor M
Published: September 2009

BACKGROUND: The phase behavior of blends of semicrystalline aryl polyesters with long methylene segments ((CH2)nwith n = 5 or 7) in the repeat units has not been much studied. Thus, crystalline/crystalline blends comprising monomorphic poly(pentamethylene terephthalate) (PPT) and polymorphic poly(heptamethylene terephthalate) (PHepT) were prepared and the crystal growth kinetics, polymorphism behavior and miscibility in this blend system were probed using polarized‐light optical microscopy, differential scanning calorimetry and wide‐angle X‐ray diffraction.

RESULTS: The PPT/PHepT blends of all compositions were first proven to be miscible in the melt state or quenched amorphous phase, whose interaction strength was determined (χ12 = − 0.35), showing favorable interactions and phase homogeneity. Although the spherulites of neat PPT and PHepT could exhibit ring bands at different crystallization temperature (Tc) ranges (100–110 and 50–65 °C, respectively), the spherulites of PPT/PHepT (50/50) blend became ringless in the range 50–110 °C. Growth analysis and polymorphic behavior in the crystalline phases of the blends provided extra evidence for the miscibility between these two crystalline polymers. Spherulitic growth rates of PPT in the PPT/PHepT blends were significantly reduced in comparison with those of neat PPT. In addition, miscible blending of a small fraction of monomorphic PPT (20 wt%) with polymorphic PHepT altered the crystal stability and led to the originally polymorphic PHepT exhibiting only the β‐crystal form when melt‐crystallized at all values of Tc.

CONCLUSION: The highly intimate mixing in polymer chains of crystalline PPT and PHepT causes significant disruption in ring‐band patterns and reduction in crystallization rates of PPT as well as alteration in the polymorphic behavior of PHepT. Copyright © 2009 Society of Chemical Industry
Initiating events and independent protection layers
Authors: Murphy John F. , Chastain Wayne , Bridges William (Bill)
Published: September 2009

Layer of protection analysis (LOPA) is a semiquantitative tool for analyzing and assessing process risk. The tool has grown greatly in popularity and usefulness since the publication of the first CCPS/AIChE guidebook on the subject, Layer of Protection Analysis, Simplified Process Risk Assessment (LOPA). This article is a summary of a new CCPS guideline book that includes the following:

Initiating events (IEs).

Independent protection layers (IPLs).

Criteria for identifying the value of each prospective IE and prospective IPL.

Example IE and IPL data.

This book is a necessary reference for those applying the LOPA methodology. © 2009 American Institute of Chemical Engineers Process Saf Prog, 2009
Re‐thinking environmental flows: from allocations and reserves to sustainability boundaries
Authors: Richter Brian D.
Published: September 2009

Attempts to implement environmental flows have encountered many obstacles. Many water allocation systems include a system of prioritization among water uses that generally does not favor environmental flow protection, or do not allow for protection of high flow events for ecological purposes. It has proven very difficult to implement complicated environmental flow prescriptions that attempt to mimic natural flow variability within water allocation systems. Additionally, many water allocation systems do not adequately address interconnections between surface water and groundwater, or releases from dams. It is time to re‐think our approaches to protecting environmental flows. As with water quality protection, environmental flows should be viewed not as an “allocation” of water, but rather as a desirable outcome of integrated management of water and land resources for long‐term sustainability. In this sense, environmental flows should be managed in a manner similar to water quality protection, in which the influences of diverse land and water use activities are regulated to ensure that the ecological and social values of water are optimized. Both water quality and environmental flow management protect a vast array of important social benefits that are sustained by managing for healthy freshwater ecosystems. In this paper I offer a definition of sustainable water management that explicitly recognizes the fact that society derives substantial benefits both from out‐of‐stream extractions of water as well as by maintaining adequate flows of water within freshwater ecosystems. To help facilitate sustainable water management, a ”Sustainability Boundary Approach“ is described for use in setting quantitative water management goals. When the cumulative hydrologic impacts of water and land uses are managed within these sustainability boundaries, the full array of values associated with water can be more fully realized. Copyright © 2009 John Wiley & Sons, Ltd.
malnets: large‐scale malicious networks via compromised wireless access points
Authors: Traynor Patrick , Butler Kevin , Enck William , McDaniel Patrick , Borders Kevin
Published: September 2009

Densely populated areas are increasingly filled with vulnerable wireless routers set up by unsophisticated users. In isolation, such routers appear to represent only a minor threat, but in aggregate, the threat can be much greater. We introduce the notion of malnets: networks of adversary‐controlled wireless routers targeted to a physical geography. Similar to Internet worms such as Slammer and Code‐Red, malnets are created by the recursive compromise of targeted devices. However, unlike their traditionally wired counterparts, malnet worms exploit only other routers that are within their transmission range. The malnet thus creates a parallel wireless infrastructure that is (a) completely under control of the adversary, and (b) spans a targeted physical area, creating a valuable infrastructure for a variety of virtual and physical attacks. We initially study the propagation characteristics of commercial routers and model inter‐router connectivity using publicly available war‐driving data. The resulting characterization is applied to well‐known epidemiological models to explore the success rates and speeds of malnet creation across cities such as New York, Atlanta, and Los Angles. Finally, we use a sampling of available exploits to demonstrate the construction of multi‐vector, multi‐platform worms capable of targeting wireless routers. Our analysis show that an adversary can potentially deploy a malnet of over 24,000 routers in Manhattan in less than 2,h. Through this work we show that malnets are not only feasible but can be efficiently deployed. Copyright © 2009 John Wiley & Sons, Ltd.
Model‐driven architecture of a maritime surveillance system simulator
Authors: Monperrus M. , Long B. , Champeau J. , Hoeltzener B. , Marchalot G. , Jézéquel J.M.
Published: September 2009

This article reports on an experiment to apply a model‐driven approach for systems engineering in an industrial context. This experiment consisted of setting up a model‐driven simulation environment for a maritime surveillance system. The simulation is fully based on three models, each conforming to a specific metamodel. We discuss the main advances given by model‐driven orientated simulation for systems engineering. © 2009 Wiley Periodicals, Inc. Syst Eng
Has the Partington procedure for chronic pancreatitis become a thing of the past? A review of the evidence
Authors: Isaji Shuji
Published: September 2009

Introduction

For the surgical management of chronic pancreatitis with an inflammatory pancreatic head mass, extended drainage operations such as Beger and Frey procedures were established in the 1980s as an alternative to resectional procedures like pancreaticoduodenectomy and as opposed to simple drainage operations such as lateral pancreaticojejunostomy, that is, the Partington procedure. With the relatively rapid adoption of the two procedures, it seems that the Partington procedure has become a thing of the past.

Materials and methods

The Partington procedure was re‐evaluated with regard to the historical aspects and its present status by a literature review.

Results

The results show that this procedure relieves chronic abdominal pain in 66–91% of patients with a mean follow‐up of 3.5–9.1 years. It is important to note that this procedure is generally used for inflammatory disease left of the gastroduodenal artery and is specifically not used as the procedure of choice for inflammatory disease of the pancreatic head.

Conclusion

For patients with a dilated main pancreatic duct but without an inflammatory pancreatic head mass, the Partington procedure is still the procedure of choice, since it is technically simple to perform with a minimum of morbidity and mortality, preserving pancreatic endocrine and exocrine function. Because it is a relatively simple technique, the laparoscopic approach will be justified as a treatment of appropriate patients in the near future.
Conjugated Linoleic Acid Induces Uncoupling Protein 1 in White Adipose Tissue of ob/ob Mice
Authors: Wendel Angela A. , Purushotham Aparna , Liu Li‐Fen , Belury Martha A.
Published: September 2009

Conjugated linoleic acid (CLA) reduces body weight and adipose mass in a variety of species. The mechanisms by which CLA depletes adipose mass are unclear, but two independent microarray analyses indicate that in white adipose tissue (WAT), uncoupling protein 1 (UCP1) was among genes most changed by CLA. The objective of this study was to determine whether CLA induces ectopic expression of UCP1 in WAT, which may contribute to increased energy expenditure and weight loss. Six‐week old, male ob/ob mice were fed either a control diet (CON) or a diet supplemented with 1.5% mixed isomer CLA (CLA) for 4 weeks. A third group of mice (LEPTIN) was fed the control diet and received daily injections of recombinant leptin as a positive control for adipose depletion in ob/ob mice. CLA did not alter several mRNA markers of lipid oxidation in epididymal white adipose tissue (eWAT), but significantly increased carnitine palmitoyltransferase‐1b (CPT1b) and PPAR gamma coactivator‐1α (PGC1α) expression. Notably, CLA increased both mRNA and protein expression of uncoupling protein‐1 (UCP1). β3‐adrenoceptor mRNA and phosphorylated‐p38 mitogen activated protein kinase (MAPK) protein levels were not affected by CLA, but were upregulated by LEPTIN. These data suggest the increased CPT1b, PGC1α, and UCP1, in WAT of CLA‐fed mice may contribute to the depletion of adipose, and CLA does not appear to increase UCP1 through β3‐adrenergic signaling. Future studies will focus on understanding how CLA increases mitochondrial oxidation and energy dissipation in white adipose tissue.
Asset Substitution and Structured Financing
Authors: Vanden Joel M.
Published: September 2009

This article shows how structured financing can be used to solve the asset substitution problem in a dynamic setting. Structuring induces the firm’s owner to optimally choose the first best operating strategy even though the owner’s value function might be locally convex (concave), which would ordinarily lead to overinvestment (underinvestment) in risky projects. This result is demonstrated in two different continuous time settings—one that is based on the risk-shifting framework of Leland (1998) and one that generalizes the scaled return model of Green (1984). It is shown that the contractual nature of the structuring is a key determinant of the issuing firm’s dynamic asset volatility. Furthermore, unlike nonstructured financing, the default (conversion) probability of a structured debt security may be increasing (decreasing) in the firm’s total assets. Structured securities are therefore hedge assets, which potentially explains the popularity of structured securities among investors and third-party issuers.
Role of magnetic resonance imaging in evaluating sphenoid sinus and internal carotid artery
Authors: Hatipoglu H G , Cetin M A , Selvi A , Yuksel E
Published: September 2009

Objective:

This study aimed to determine whether magnetic resonance imaging has a role in the evaluation of the sphenoid sinus and internal carotid artery. In addition, we aimed to establish reference measurements for the minimal distance between the internal carotid arteries.

Method:

The sphenoid sinuses and neighbouring internal carotid arteries of 90 patients were evaluated using sagittal T1-weighted and axial and coronal T2-weighted magnetic resonance images.

Results:

Sphenoid sinus pneumatisation was categorised as occipitosphenoidal (0 per cent), conchal (3.3 per cent), presellar (14.4 per cent) or sellar (82.2 per cent). The internal carotid artery protruded into the sphenoid sinus in 32.8 per cent, with a septum in 9.4 per cent. The incidence of sellar-type sphenoid sinus pneumatisation was higher in patients with protrusion of the internal carotid artery into the sphenoid sinus (p < 0.001). The incidence of presellar pneumatisation was higher in patients without internal carotid artery protrusion (p < 0.001). The minimal distance between the internal carotid arteries varied between 9.04 and 24.26 mm (mean, 15.94 mm).

Conclusion:

Magnetic resonance imaging can provide useful information about the sphenoid sinus and internal carotid artery, prior to endoscopic sphenoidotomy and trans-sphenoidal hypophysectomy.
Cochlear implantation at King Abdulaziz University Hospital, Riyadh, Saudi Arabia: a 12-year experience
Authors: Al-Muhaimeed H S , Al-Anazy F , Attallah M S , Hamed O
Published: September 2009

Objective:

This paper aims to report our experience with different multichannel cochlear implant devices, and to discuss the outcomes of our cochlear implant programme, together with the problems encountered.

Setting:

Cochlear implantation was undertaken in 117 patients (35 post-lingual and 82 pre-lingual cases; 70 males and 47 females) over a 12-year period. Three cochlear implant systems were used: Nucleus (22 and 24), Med-El and Advanced Bionics Clarion. An extended endaural incision was used in 78 cases and a minimally invasive approach in 39 cases.

Results:

Complications occurred in 16.2 per cent of patients. All patients showed a significant post-implantation improvement in their perception and discrimination of sound and speech. Better results were noted in pre-lingual patients under the age of six years. The cause of hearing loss was unknown in 81 per cent of patients.

Conclusion:

The outcomes of our cochlear implantation series are comparable to previous reports. The possibility of an abnormally rotated cochlea should be borne in mind when difficulty is encountered during cochleostomy.
‘Active ageing’: a qualitative study in six Caribbean countries
Authors: CLOOS PATRICK , ALLEN CAROLINE F. , ALVARADO BEATRIZ E. , ZUNZUNEGUI MARIA VICTORIA , SIMEON DONALD T. , ELDEMIRE-SHEARER DENISE
Published: September 2009

The aim of this study was to document the perceptions of elders in six Caribbean countries about ‘active ageing’ and on the basis of their reports to make recommendations to improve their situation. Data were collected principally through 31 focus group discussions conducted in both urban and rural areas. Comparative analysis was carried out of the qualitative information, focusing on three components of ‘active ageing’: health and social services access and use, social support, and economic circumstances. Most of the participants were women, aged 60–79 years, of lower socio-economic status and from urban areas. Large disparities in the responses of Caribbean societies to population ageing were indicated, as well as unequal opportunities to obtain health care and social services, public transport, income and food by both socio-economic status and location. Home-care services are either insufficient or non-existent. Some elders receive social and financial support from relatives while others fear isolation and face deprivation. Social participation varies by place, physical condition, financial situation, association membership, and transport opportunities. Social protection benefits do not provide adequate income and some older people face food insecurity. It was concluded that a comprehensive and multi-sectoral approach using the ‘active ageing’ framework should be implemented to ensure a healthy ageing process.
On the interaction between sharing and linearity
Authors: AMATO GIANLUCA , SCOZZARI FRANCESCA
Published: September 2009

In the analysis of logic programs, abstract domains for detecting sharing and linearity information are widely used. Devising abstract unification algorithms for such domains has proved to be rather hard. At the moment, the available algorithms are correct but not optimal; i.e., they cannot fully exploit the information conveyed by the abstract domains. In this paper, we define a new (infinite) domainShLinωwhich can be thought of as a general framework from which other domains can be easily derived by abstraction.ShLinωmakes the interaction between sharing and linearity explicit. We provide a constructive characterization of the optimal abstract unification operator onShLinω, and we lift it to two well-known abstractions ofShLinω, namely, to the classicalSharing×Linabstract domain and to the more preciseShLin2abstract domain by Andy King. In the case of single-binding substitutions, we obtain optimal abstract unification algorithms for such domains.
Ein «Gutes Sterben» und ein «Guter Tod»: zum Verständnis des Sterbeideals und seiner Bedeutung für Hospiz und Palliative Care
Authors: Steffen-Bürgi Barbara
Published: September 2009

Es gehört zu den prioritären Zielen der modernen Hospizbewegung und der Palliative Care, schwer kranken und sterbenden Menschen ein «gutes Lebensende» bzw. ein «gutes Sterben» zu ermöglichen. Die Vorstellungen davon, was ein «gutes Sterben» ausmacht, spiegeln sich im jeweiligen Sterbeideal. Die Literaturanalyse diente der konzeptuellen Klärung des gegenwärtigen Verständnisses vom «guten Sterben» und «guten Tod», ihrer Merkmale sowie der mit dem Sterbeideal zusammenhängenden theoretischen und ideellen Grundlagen. Im Artikel werden die Bedeutung des Sterbeideals als Orientierungspunkt und Leitidee zur Gestaltung der palliativen und hospizlichen Betreuung, die theoretischen Hintergründe und die Komponenten des «guten Sterbens» dargestellt.
Comparison of modeling methods for the determination of effective porosities and diffusion coefficients in through‐diffusion tests
Authors: Benning Jennifer L. , Barnes David L.
Published: September 2009

Diffusion coefficients and effective, or transport, porosities are important parameters in the assessment of the fate and transport of contaminants in fractured rock systems and when contaminant transport needs to be considered in zones of low to negligible advective flows. This study presents and discusses various solutions, analytical and semianalytical, to Fick's law for the typical through‐diffusion experiment and applies these solutions to the results of three through‐diffusion experimental data sets. These through‐diffusion experiments were conducted on two natural breccia samples, with bulk measured porosities of approximately 13.7% and 16.8%, and one manufactured porous plate sample with a bulk measured porosity of 40.9%, such that the samples displayed order of magnitude differences in their diffusivities. For each experiment, the derived effective porosities and intrinsic diffusion coefficients for each method are compared. It was shown that the semianalytical solution provides an improved method for reliably estimating the effective porosity from through‐diffusion experimental data; however, there is little difference between methods in the derived intrinsic diffusion coefficients.
An observation‐based stochastic model for sediment and vegetation dynamics in the floodplain of an Alpine braided river
Authors: Perona P. , Molnar P. , Savina M. , Burlando P.
Published: September 2009

Riparian vegetation dynamics in Alpine rivers are to a large extent driven by the timing and magnitude of floods which inundate the floodplain, transport sediment, erode the river bed, and create and destroy suitable germination sites. Here we present a stochastic approach for studying sediment‐vegetation dynamics lumped at the floodplain scale and driven by stochastic flood disturbances. The premise of the model is that floods erode riparian vegetation in the inundated part of the floodplain and expose bare sediment surfaces. In the absence of subsequent flooding these surfaces are gradually recolonized. The stochastic nature of the disturbance process and the deterministic rate of vegetation colonization are described by a Poisson arrival of floods and a process equation which treats the floodplain erosion and vegetation colonization processes, respectively. An analytical solution is developed to obtain the probability density function of the exposed sediment area. The model is applied to the Maggia River in Switzerland, where it reproduces the changes in riparian vegetation cover observed from aerial photographs with an absolute error less than 5%. The model has potential as a tool to study the impacts of changes in the disturbance regime on sediment and vegetation dynamics.
Constraints on asthenospheric flow from the depths of oceanic spreading centers: The East Pacific Rise and the Australian‐Antarctic Discordance
Authors: Buck W. Roger , Small Christopher , Ryan William B. F.
Published: September 2009

The fastest spreading center, the East Pacific Rise (EPR), is consistently deeper than most other spreading centers. Its average depth along the ∼5000 km length is ∼3100 m, while the mean depth along the adjacent, slower spreading Pacific‐Antarctic Rise (PAR) is ∼2700 m. The deepest spreading center is the ∼4000 m deep, ∼1000 km long Australian Antarctic Discordance (AAD). Analytic and numerical models show that dynamic thinning of asthenosphere can explain the magnitude and wavelength of the depth anomalies along the EPR and AAD. Previous models did not show such significant depth anomalies along spreading centers because the equations used to describe flow of thin viscous asthenosphere were linearized. At the EPR, fast plate divergence thins the asthenosphere by both sequestering it into diverging lithosphere and dragging it with the plates in contrast to the slower spreading but faster migrating PAR. The AAD asthenosphere is starved because of the restriction of asthenospheric flow due to nearby thick continental lithospheric roots combined with a moderately fast spreading rate. A narrow range of asthenospheric properties explains observed depth anomalies for both the AAD and EPR. If the asthenosphere is ∼100°C hotter, and so ∼10 kg/m3 less dense than the underlying asthenosphere, then the model requires an average asthenospheric thickness of ∼250 km and a viscosity of ∼1019 Pa s. Thinner asthenosphere works in the model if it has a lower density and lower viscosity. Although the source of the asthenosphere is not critical to our models, we assume that it is supplied by upwelling of depleted mantle plumes in contrast to enriched plumes that feed oceanic island basalts.
NOx descent in the Arctic middle atmosphere in early 2009
Authors: Randall C. E. , Harvey V. L. , Siskind D. E. , France J. , Bernath P. F. , Boone C. D. , Walker K. A.
Published: September 2009

Measurements by the Atmospheric Chemistry Experiment show that the amount of NOx (NO + NO2) produced by energetic particle precipitation (EPP) that descended from the Arctic mesosphere and lower thermosphere into the stratosphere in early 2009 was up to ∼50 times higher than average in 2005, 2007 and 2008. This is of note because the level of EPP in the preceding months was very low, suggesting that excess production of NOx was not the cause of the enhancements. Rather, the enhancements are attributed to unusually strong descent in the middle atmosphere. This is the third time on record that extraordinary meteorology contributed to descent of excess NOx. The results confirm that EPP impacts on the middle atmosphere can be large even in the absence of exceptional EPP, and highlight the need to continually measure NOx throughout the polar region from the stratosphere to the lower thermosphere.
Summer monsoon onset in the subtropical western North Pacific
Authors: Wu Chi‐Hua , Kau Wen‐Shung , Chou Ming‐Dah
Published: September 2009

Monsoon onset in July over the subtropical western North Pacific (SWNP, 15–25°N; 130–150°E) is investigated by focusing on the westward movement of cloudy region east of the SWNP, which is associated with high vorticity in the upper troposphere. At least in seven of the 22 years between 1985 and 2006, the arrival of clouds at the SWNP from the east coincides with a significant change in the upper tropospheric circulation and a rapid northeastward extension of strong convections from the tropical western North Pacific, which essentially is monsoon onset. Before the monsoon onset, the sea surface temperature (SST) increases, but winds remain divergent over the SWNP. Right after the monsoon onset, winds turn convergent and convections enhance, leading to a rapid decrease of surface heating and SST. It is suggested that westward‐moving upper‐level disturbances might trigger onset of monsoon in July when low‐level atmospheric conditions favor development of deep convections.
Charging of spinning insulating objects by plasma and photoemission
Authors: Miloch W. J. , Vladimirov S. V.
Published: September 2009

The charging of spinning insulating objects by plasma and photoemission is studied in two spatial dimensions with the particle‐in‐cell method. Unidirectional photon flux, different angular velocities of the object, and different plasma flow speeds are considered. Photoemission can lead to a positive total charge and electric dipole moment on the object. The spinning of the object redistributes the surface charge and leads to asymmetric potential barriers near the object. The total charge on the object oscillates in time with the period matching the period of the object rotation. The plasma potential and density in the vicinity of the object oscillate with the same frequency. For flowing plasmas, the wake in the ion density is conspicuous behind a positively charged object. The time averaged charge on the object depends on its angular velocity.
The opportunistic coral pathogen Aspergillus sydowii contains dddP and makes dimethyl sulfide from dimethylsulfoniopropionate
Authors: Kirkwood Mark , Todd Jonathan D , Rypien Krystal L , Johnston Andrew W B
Published: September 2009

The ascomycete Aspergillus sydowii is associated with a serious epizootic of sea fan corals in the Caribbean. Corals are rich in the compatible solute, dimethylsulfoniopropionate (DMSP), produced by their symbionts, the dinoflagellate Symbiodinium. As other Aspergillus species can catabolize DMSP, liberating dimethyl sulfide (DMS) in the process, we tested A. sydowii strains, obtained from diseased corals and other environments, for this Ddd+ phenotype. All the strains, irrespective of their geographical or environmental origins, made DMS from DMSP, and all of them contained homologs (>87% identical) of the dddP gene, which encodes an enzyme that releases DMS from DMSP and which occurs in other Ddd+ fungi and in some marine bacteria. The dddP gene was likely acquired by the Aspergillus fungi by inter-domain horizontal gene transfer from α-proteobacteria.
Gene-targeted-metagenomics reveals extensive diversity of aromatic dioxygenase genes in the environment
Authors: Iwai Shoko , Chai Benli , Sul Woo Jun , Cole James R , Hashsham Syed A , Tiedje James M
Published: September 2009

Understanding the relationship between gene diversity and function for important environmental processes is a major ecological research goal. We applied gene-targeted metagenomics and pyrosequencing to aromatic dioxygenase genes to obtain greater sequence depth than possible by other methods. A polymerase chain reaction (PCR) primer set designed to target a 524-bp region that confers substrate specificity of biphenyl dioxygenases yielded 2000 and 604 sequences from the 5′ and 3′ ends of PCR products, respectively, which passed our validity criteria. Sequence alignment showed three known conserved residues, as well as another seven conserved residues not reported earlier. Of the valid sequences, 95% and 41% were assigned to 22 and 3 novel clusters in that they did not include any earlier reported sequences at 0.6 distance by complete linkage clustering for sequenced regions. The greater diversity revealed by this gene-targeted approach provides deeper insights into genes potentially important in environmental processes to better understand their ecology, functional differences and evolutionary origins. We also provide criteria for primer design for this approach, as well as guidance for data processing of diverse functional genes, as gene databases for most genes of environmental relevance are limited.
Mice Deficient in Phosphofructokinase‐M Have Greatly Decreased Fat Stores
Authors: Getty‐Kaushik Lisa , Viereck Jason C. , Goodman Jessie M. , Guo Zifang , LeBrasseur Nathan K. , Richard Ann‐Marie T. , Flanagan John N. , Yaney Gordon C. , Hamilton James A. , Tornheim Keith
Published: September 2009

Synthesis of triacylglycerol requires the glucose‐derived glycerol component, and glucose uptake has been viewed as the rate‐limiting step in glucose metabolism in adipocytes. Furthermore, adipose tissue contains all three isoforms of the glycolytic enzyme phosphofructokinase (PFK). We here report that mice deficient in the muscle isoform PFK‐M have greatly reduced fat stores. Mice with disrupted activity of the PFK‐M distal promoter were obtained from Lexicon Pharmaceuticals, developed from OmniBank OST#56064. Intra‐abdominal fat was measured by magnetic resonance imaging of the methylene proton signal. Lipogenesis from labeled glucose was measured in isolated adipocytes. Lipolysis (glycerol and free fatty acid release) was measured in perifused adipocytes. Intra‐abdominal fat in PFK‐M–deficient female mice (5–10 months old) was 17 ± 3% of that of wild‐type littermates (n = 4; P < 0.02). Epididymal fat weight in 15 animals (7–9.5 months) was 34 ± 4% of control littermate (P < 0.002), with 10–30% lower body weight. Basal and insulin‐stimulated lipogenesis in PFK‐M–deficient epididymal adipocytes was 40% of the rates in cells from heterozygous littermates (n = 3; P < 0.05). The rate of isoproterenol‐stimulated lipolysis in wild‐type adipocytes declined ∼10% after 1 h and 50% after 2 h; in PFK‐M–deficient cells it declined much more rapidly, 50% in 1 h and 90% in 2 h, and lipolytic oscillations appeared to be damped (n = 4). These results indicate an important role for PFK‐M in adipose metabolism. This may be related to the ability of this isoform to generate glycolytic oscillations, because such oscillations may enhance the production of the triacylglycerol precursor α‐glycerophosphate.
Increase in the Prevalence of Obesity in Switzerland 1982–2007: Birth Cohort Analysis Puts Recent Slowdown into Perspective
Authors: Faeh David , Bopp Matthias
Published: September 2009

Although the prevalence of obesity continues to increase in Switzerland, the latest figures suggest a slowdown in the rate of increase. In order to elucidate whether this could be the onset of a trend reversal, we analyzed cross‐sectional data by birth cohort. We assessed the prevalence of overweight+ (BMI ≥25 kg/m2) and obesity (BMI ≥30 kg/m2) in six population surveys with self‐reported height and weight values (Switzerland, N = 68,829, 1982–2007, men (45%) and women (55%), aged 20–84 years) by 10‐year birth cohorts (from the decade 1910–1919 through to 1970–1979). We found that increases in the prevalence of overweight+ and obesity occurred mainly in the cohort born 1930 to 1939, and again in the cohorts born 1960 to 1979. The accelerated increase in the prevalence of overweight+ in the youngest birth cohort and the lower prevalence in the oldest birth cohorts suggest that the current slowdown seen in Switzerland may not herald the onset of a trend reversal. As this example shows, simple comparisons of prevalence rates over time could provide a misleading picture of actual trends. Birth cohort analysis may offer a valuable alternative.
Illusory Movement of Dotted Lines
Authors: Ito Hiroyuki , Anstis Stuart , Cavanagh Patrick
Published: September 2009

When oblique rows of black and white dots drifted horizontally across a mid-grey surround, the perceived direction of motion was shifted to be almost parallel to the dotted lines and was often nearly orthogonal to the real motion. The reason is that the black/white contrast signals between adjacent dots along the length of the line are stronger than black/grey or white/grey contrast signals across the line, and the motion is computed as a vector sum of local contrast-weighted motion signals.
The Meteorite Collection in the Natural Science Museum of Turin
Authors: Costa E. , Gallo L. M.
Published: September 2009

The Natural Science Museum of Turin is the owner of a small but nice collection of meteorites, partly obtained by means of direct acquisition during the last 30 years, and partly inherited from the rather old collection of the University of Turin. This collection was partially forgotten for the last 50 years, and after 1936 the collection became almost invisible. In the last 30 years the meteorite samples were tightly packaged and retained in the basement of the museum building. Currently a new listing of the meteorite collection is in progress and almost finished, in which every sample is described, measured and weighed. For each sample the authors acquired high resolution images and examined historical documentations. Images were acquired with a desktop scanner, which was found to be an ideal tool for this purpose. A classification based on most famous meteorite catalogues is coupled to each description. About eighty samples (and probably a new meteorite, not described until now) will be depicted in the new catalogue, which hopefully will be published during 2009. The authors want to inform the international community that Turin the Museum holds an important collection containing almost all of the Piedmont meteorites (e.g. MOTTA DI CONTI, CERESETO, ALESSANDRIA), some Italian meteorites of considerable historical importance (TRONZANO, ALFIANELLO, ASSISI, SIENA), together with a selection of American and Eastern European samples.
Fluorine Abundances in AGB Carbon Stars: New Results?
Authors: Abia C. , de Laverny P. , Recio-Blanco A. , Domínguez I. , Cristallo S. , Straniero O.
Published: September 2009

A recent reanalysis of the fluorine abundance in three Galactic Asymptotic Giant Branch (AGB) carbon stars (TX Psc, AQ Sgr and R Scl) by Abia et al. (2009) results in estimates of fluorine abundances systematically lower by ∼0.8 dex on average, with respect to the sole previous estimates by Jorissen, Smith & Lambert (1992). The new F abundances are in better agreement with the predictions of full-network stellar models of low-mass (<3 M⊙) AGB stars.
Searching for s-Process-Enhanced Metal-Poor Stars
Authors: Cruz M. A. , Rossi S. , Beers T. C.
Published: September 2009

We present preliminary results for the estimation of barium [Ba/Fe], and strontium [Sr/Fe], abundances ratios using medium-resolution spectra (1–2 Å). We established a calibration between the abundance ratios and line indices for Ba and Sr, using multiple regression and artificial neural network techniques. A comparison between the two techniques (showing the advantage of the latter), as well as a discussion of future work, is presented.
Opportunities for Nuclear Astrophysics at FRANZ
Authors: Reifarth R. , Chau L. P. , Heil M. , Käppeler F. , Meusel O. , Plag R. , Ratzinger U. , Schempp A. , Volk K.
Published: September 2009

The ‘Frankfurter Neutronenquelle am Stern–Gerlach–Zentrum’ (FRANZ), which is currently under development, will be the strongest neutron source in the astrophysically interesting energy region in the world. It will be about three orders of magnitude more intense than the well-established neutron source at the Research Center Karlsruhe (FZK).