bluuebunny/crossref_metadata_2025 huggingface dataset:
Are There Efficiency Gains from the Removal of Natural Resource Export Restrictions? Evidence from British Columbia
Authors: Fooks Jacob R. , Dundas Steven J. , Awokuse Titus O.
Published: February 2013

Log export bans (LEBs) are a popular development tool utilised by developing nations with sizable endowments of timber; however, the actual impact of these policies is debatable. British Columbia has a developed forestry sector and still maintains a LEB. This trade restriction continually creates conflicts with Canada's international trade partners, including the United States. This paper examines the efficiency implications of a hypothetical removal of roundwood export restrictions in British Columbia using roundwood price and quantity data from 1995 to 2008. A time‐series econometric approach is utilised to determine supply and demand elasticities for British Columbia's roundwood. Empirical results from a vector error correction model suggest that a removal of export restrictions will generate an overall increase of approximately $347.91 million US dollars per year to British Columbia's forest economy.
A novel model for simultaneous study of neointestinal regeneration and intestinal adaptation
Authors: Jwo Shyh‐Chuan , Tang Shye‐Jye , Chen Jim‐Ray , Chiang Kun‐Chun , Huang Ting‐Shou , Chen Huang‐Yang
Published: February 2013

The use of autologous grafts, fabricated from tissue‐engineered neointestine, to enhance insufficient compensation of intestinal adaptation for severe short bowel syndrome is a compelling idea. Unfortunately, current approaches and knowledge for neointestinal regeneration, unlike intestinal adaptation, are still unsatisfactory. Thus, we have designed a novel model of intestinal adaptation with simultaneous neointestinal regeneration and evaluated its feasibility for future basic research and clinical application. Fifty male Sprague‐Dawley rats weighing 250–350 g underwent this procedure and sacrificed at 4, 8, and 12 weeks postoperatively. Spatiotemporal analyses were carried out by gross, histology, and DNA/protein quantification. Three rats died of operative complications. In early experiments, the use of hard silicone stent as tissue scaffold in 11 rats was unsatisfactory for neointestinal regeneration. In later experiments, when a soft silastic tube was used, the success rate increased up to 90.9%. Further analyses revealed that no neointestine developed without donor intestine; regenerated lengths of mucosa and muscle were positively related to time postsurgery but independent of donor length with 0.5 or 1 cm. Other parameters of neointestinal regeneration or intestinal adaptation showed no relationship to both time postsurgery and donor length. In conclusion, this is a potentially important model for investigators searching for solutions to short bowel syndrome.
Automated cell‐specific laser detection and ablation of neural circuits in neonatal brain tissue
Authors: Wang Xueying , Hayes John A. , Picardo Maria Cristina D. , Del Negro Christopher A.
Published: February 2013

Key points

We developed an automated system that detects neurons belonging to specific populations in vitro or in situ, maps their physical locations in three‐dimensional tissue specimens and then laser ablates the cell ‘targets’ one at a time, in sequence, while monitoring neural population activity electrophysiologically.

Two‐photon Ca2+ imaging and image processing routines detect and validate target neurons based on rhythmic Ca2+ fluorescence activity patterns.

Visible‐wavelength confocal imaging and image processing routines detect and validate target neurons that express genetically encoded fluorescent proteins.

High‐intensity two‐photon spot scanning vaporizes target neurons with specificity while minimizing damage to neighbouring tissue.

Physiological monitoring of network function is performed before, during and after the cell‐specific laser ablations to measure the effects on network functionality in real time.

Abstract  A key feature of neurodegenerative disease is the pathological loss of neurons that participate in generating behaviour. To investigate network properties of neural circuits and provide a complementary tool to study neurodegeneration in vitro or in situ, we developed an automated cell‐specific laser detection and ablation system. The instrument consists of a two‐photon and visible‐wavelength confocal imaging setup, controlled by executive software, that identifies neurons in preparations based on genetically encoded fluorescent proteins or Ca2+ imaging, and then sequentially ablates cell targets while monitoring network function concurrently. Pathological changes in network function can be directly attributed to ablated cells, which are logged in real time. Here, we investigated brainstem respiratory circuits to demonstrate single‐cell precision in ablation during physiological network activity, but the technique could be applied to interrogate network properties in neural systems that retain network functionality in reduced preparations in vitro or in situ.
Pyridostigmine but not 3,4‐diaminopyridine exacerbates ACh receptor loss and myasthenia induced in mice by muscle‐specific kinase autoantibody
Authors: Morsch Marco , Reddel Stephen W. , Ghazanfari Nazanin , Toyka Klaus V. , Phillips William D.
Published: February 2013

Key points

A mouse model of anti‐muscle‐specific kinase (MuSK) myasthenia gravis was used to study the effect of pyridostigmine (a cholinesterase inhibitor drug commonly used in myasthenia) on the disease process at the neuromuscular junction.

In mice receiving injections of anti‐MuSK‐positive patient IgG, pyridostigmine treatment for 7–9 days did not prevent myasthenia, and even precipitated weakness.

Pyridostigmine treatment potentiated the anti‐MuSK‐induced reductions in postsynaptic acetylcholine receptor density and endplate potential (EPP) amplitude.

3,4‐Diaminopyridine, a drug that increases the number of quanta released (rather than the duration of each quantal response), elevated EPP amplitude without exacerbating the anti‐MuSK‐induced loss of acetylcholine receptors.

The results suggest that cholinergic‐ and MuSK‐mediated signalling may converge postsynaptically to regulate the mature acetylcholine receptor scaffold.

Abstract  In myasthenia gravis, the neuromuscular junction is impaired by the antibody‐mediated loss of postsynaptic acetylcholine receptors (AChRs). Muscle weakness can be improved upon treatment with pyridostigmine, a cholinesterase inhibitor, or with 3,4‐diaminopyridine, which increases the release of ACh quanta. The clinical efficacy of pyridostigmine is in doubt for certain forms of myasthenia. Here we formally examined the effects of these compounds in the antibody‐induced mouse model of anti‐muscle‐specific kinase (MuSK) myasthenia gravis. Mice received 14 daily injections of IgG from patients with anti‐MuSK myasthenia gravis. This caused reductions in postsynaptic AChR densities and in endplate potential amplitudes. Systemic delivery of pyridostigmine at therapeutically relevant levels from days 7 to 14 exacerbated the anti‐MuSK‐induced structural alterations and functional impairment at motor endplates in the diaphragm muscle. No such effect of pyridostigmine was found in mice receiving control human IgG. Mice receiving smaller amounts of MuSK autoantibodies did not display overt weakness, but 9 days of pyridostigmine treatment precipitated generalised muscle weakness. In contrast, one week of treatment with 3,4‐diaminopyridine enhanced neuromuscular transmission in the diaphragm muscle. Both pyridostigmine and 3,4‐diaminopyridine increase ACh in the synaptic cleft yet only pyridostigmine potentiated the anti‐MuSK‐induced decline in endplate ACh receptor density. These results thus suggest that ongoing pyridostigmine treatment potentiates anti‐MuSK‐induced AChR loss by prolonging the activity of ACh in the synaptic cleft.
Hull Slamming
Authors: Abrate Serge
Published: February 2013

This report presents an in-depth review of the current state of knowledge on hull slamming, which is one of several types of slamming problems to be considered in the design and operation of ships. Hull slamming refers to the impact of the hull or a section of the hull as it reenters the water. It can be considered to be part of a larger class of water entry problems that include the water landing of spacecraft and solid rocket boosters, the water landing and ditching of aircraft, ballistic impacts on fuel tanks, and other applications. The problem involves the interaction of a structure with a fluid that has a free surface. Significant simplifications can be achieved by considering a two-dimensional cross section of simple shape (wedge, cone, sphere, and cylinder) and by assuming that the structure is a rigid body. The water is generally modeled as an incompressible, irrotational, inviscid fluid. Two approximate solutions developed by von Karman (1929, “The Impact on Seaplane Floats During Landing,” NACA Technical Note NACA-TN-32) and Wagner (1932, “Uber stoss und Gleitvorgange an der Oberache von Flussigkeiten,” Z. Angew. Math. Mech., 12, pp. 192–215) can be used to predict the motion of the body, the hydrodynamic force, and the pressure distribution on the wetted surface of the body. Near the intersection with the initial water surface, water piles up, a jet is formed, and the solution has a singularity in this region. It was shown that nearly half of the kinetic energy transferred from the solid to the fluid is contained in this jet, the rest being stored in the bulk of the fluid. A number of complicating factors are considered, including oblique or asymmetric impacts, elastic deformations, and more complex geometries. Other marine applications are considered as well as applications in aerospace engineering. Emphasis is placed on basic principles and analytical solutions as an introduction to this topic, but numerical approaches are needed to address practical problems, so extensive references to numerical approaches are also given.
Thermal stability of Ti, Pt, and Ru interfacial layers between seedless copper and a tantalum diffusion barrier
Authors: Liu Xin , King Sean W. , Nemanich Robert J.
Published: February 2013

The thermal stability of 7 nm Ti, Pt, and Ru interfacial adhesion layers between Cu film (10 nm) and a Ta barrier layer (4 nm) has been investigated. The barrier properties and interfacial stability have been evaluated by Rutherford backscattering spectrometry (RBS). Atomic force microscopy was used to measure the surfaces before and after annealing, and all the surfaces are relatively smooth which excludes islanding or dewetting phenomena as a cause of the instability. The RBS showed no discernible diffusion across the adhesion layer/Ta and Ta/Si interfaces which provides a stable underlying layer. For a Ti interfacial layer, RBS indicates that during 400 °C annealing, Ti interdiffuses through the Cu film and accumulates at the surface. For the Pt/Cu system, Pt interdiffusion is detected which is less evident than Ti. Among the three adhesion layer candidates, Ru shows negligible diffusion into the Cu film indicating thermal stability at 400 °C.
Improved imaging properties of thin attenuated phase shift masks for extreme ultraviolet lithography
Authors: Lee Sangsul , Lee Inhwan , Gul Doh Jong , Uk Lee Jae , Hong Seongchul , Ahn Jinho
Published: February 2013

The mask shadowing effect is a unique phenomenon caused by a mirror-based mask structure and an oblique incident angle of light in the extreme ultraviolet lithography process. This results in a horizontal–vertical (H–V) bias, an ellipticity in the contact hole pattern and, eventually, a patterning limit and critical dimension (CD) nonuniformity. Reducing the absorber thickness is the most effective method to minimize the mask shadowing effect, but this can deteriorate the mask image contrast. In this paper, an attenuated phase shift mask (PSM) is proposed as a potential method for extending the patterning limit to below 16 nm. By applying Mo as a phase shift layer, which has a refractive index (n) similar to that of the TaN absorber but with a lower absorption value, thin attenuated PSMs with various reflectivity values were obtained by controlling the Mo thickness. The proposed PSM consists of a 16.5-nm-thick TaN absorber layer and a 24-nm-thick Mo phase shifter on 2-nm-thick Ru-capped Mo/Si multilayers. This attenuated PSM results in 17.98% and 27.52% reductions in the mask error enhancement factor as well as 3.65 and 1.84 nm reductions in the H–V CD bias compared with the conventional binary intensity mask with a 70-nm-thick TaN absorber for the 22 nm line and space 1:1 vertical dense pattern under 0.25 and 0.33 numerical aperture illumination conditions, respectively. Moreover, a 10%–12% improved image contrast was obtained with 11%–17% reflectivity on the absorber stack, which corresponds to a 24–29 nm Mo thickness under 0.25 NA illumination conditions.
Evidence for Recent Acquisition and Successful Transmission of
bla
CTX-M-15
in Salmonella enterica in South Korea
Authors: Kang Min-Su , Kwon Yong-Kuk , Oh Jae-Young , Kim Mi-Jin , Call Douglas R. , An Byung-Ki , Shin Eun-Gyeong , Song Eun-A , Kwon Jun-Hun
Published: February 2013

We identified two distinct
bla
CTX-M
-bearing and five distinct
bla
CMY-2
-bearing genetic structures located on plasmids from
Salmonella enterica
and
Escherichia coli
isolates (
n
= 35) collected from chickens in South Korea. All
Salmonella
plasmids shared a common replicon,
bla
CTX-M-15
transposon, and core resistance phenotype, while
E. coli bla
CTX-M-15
plasmids included four distinct replicons.
Structural Insight into Potent Broad-Spectrum Inhibition with Reversible Recyclization Mechanism: Avibactam in Complex with CTX-M-15 and Pseudomonas aeruginosa AmpC β-Lactamases
Authors: Lahiri Sushmita D. , Mangani Stefano , Durand-Reville Thomas , Benvenuti Manuela , De Luca Filomena , Sanyal Gautam , Docquier Jean-Denis
Published: February 2013

Although β-lactams have been the most effective class of antibacterial agents used in clinical practice for the past half century, their effectiveness on Gram-negative bacteria has been eroded due to the emergence and spread of β-lactamase enzymes that are not affected by currently marketed β-lactam/β-lactamase inhibitor combinations. Avibactam is a novel, covalent, non-β-lactam β-lactamase inhibitor presently in clinical development in combination with either ceftaroline or ceftazidime.
In vitro
studies show that avibactam may restore the broad-spectrum activity of cephalosporins against class A, class C, and some class D β-lactamases. Here we describe the structures of two clinically important β-lactamase enzymes bound to avibactam, the class A CTX-M-15 extended-spectrum β-lactamase and the class C
Pseudomonas aeruginosa
AmpC β-lactamase, which together provide insight into the binding modes for the respective enzyme classes. The structures reveal similar binding modes in both enzymes and thus provide a rationale for the broad-spectrum inhibitory activity of avibactam. Identification of the key residues surrounding the binding pocket allows for a better understanding of the potency of this scaffold. Finally, avibactam has recently been shown to be a reversible inhibitor, and the structures provide insights into the mechanism of avibactam recyclization. Analysis of the ultra-high-resolution CTX-M-15 structure suggests how the deacylation mechanism favors recyclization over hydrolysis.
The Antimalarial Activities of Methylene Blue and the 1,4-Naphthoquinone 3-[4-(Trifluoromethyl)Benzyl]-Menadione Are Not Due to Inhibition of the Mitochondrial Electron Transport Chain
Authors: Ehrhardt Katharina , Davioud-Charvet Elisabeth , Ke Hangjun , Vaidya Akhil B. , Lanzer Michael , Deponte Marcel
Published: February 2013

Methylene blue and a series of recently developed 1,4-naphthoquinones, including 3-[4-(substituted)benzyl]-menadiones, are potent antimalarial agents
in vitro
and
in vivo
. The activity of these structurally diverse compounds against the human malaria parasite
Plasmodium falciparum
might involve their peculiar redox properties. According to the current theory, redox-active methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione are “subversive substrates.” These agents are thought to shuttle electrons from reduced flavoproteins to acceptors such as hemoglobin-associated or free Fe(III)-protoporphyrin IX. The reduction of Fe(III)-protoporphyrin IX could subsequently prevent essential hemoglobin digestion and heme detoxification in the parasite. Alternatively, owing to their structures and redox properties, methylene blue and 1,4-naphthoquinones might also affect the mitochondrial electron transport chain. Here, we tested the latter hypothesis using an established system of transgenic
P. falciparum
cell lines and the antimalarial agents atovaquone and chloroquine as controls. In contrast to atovaquone, methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione do not inhibit the mitochondrial electron transport chain. A systematic comparison of the morphologies of drug-treated parasites furthermore suggests that the three drugs do not share a mechanism of action. Our findings support the idea that methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione exert their antimalarial activity as redox-active subversive substrates.
Effectiveness of a Double-Carbapenem Regimen for Infections in Humans Due to Carbapenemase-Producing Pandrug-Resistant Klebsiella pneumoniae
Authors: Giamarellou Helen , Galani Lambrini , Baziaka Fotini , Karaiskos Ilias
Published: February 2013

Ertapenem plus doripenem or meropenem were given in three patients suffering from pandrug-resistant, KPC-2-positive
Klebsiella pneumoniae
bacteremia (2 patients) and urinary tract infection (1 patient), respectively. All responded successfully, without relapse at follow-up. The results obtained should probably be attributed to ertapenem's increased affinity for the carbapenemases hindering doripenem/meropenem degradation in the environment of the microorganism.
OXA-235, a Novel Class D β-Lactamase Involved in Resistance to Carbapenems in Acinetobacter baumannii
Authors: Higgins Paul G. , Pérez-Llarena Francisco J. , Zander Esther , Fernández Ana , Bou Germán , Seifert Harald
Published: February 2013

We investigated the mechanism of carbapenem resistance in 10
Acinetobacter baumannii
strains isolated from the United States and Mexico between 2005 and 2009. The detection of known metallo-β-lactamase or carbapenem-hydrolyzing oxacillinase (OXA) genes by PCR was negative. The presence of plasmid-encoded carbapenem resistance genes was investigated by transformation of
A. baumannii
ATCC 17978. Shotgun cloning experiments and sequencing were performed, followed by the expression of a novel β-lactamase in
A. baumannii
. Three novel OXA enzymes were identified, OXA-235 in 8 isolates and the amino acid variants OXA-236 (Glu173-Val) and OXA-237 (Asp208-Gly) in 1 isolate each. The deduced amino acid sequences shared 85% identity with OXA-134, 54% to 57% identities with the acquired OXA-23, OXA-24, OXA-58, and OXA-143, and 56% identity with the intrinsic OXA-51 and, thus, represent a novel subclass of OXA. The expression of OXA-235 in
A. baumannii
led to reduced carbapenem susceptibility, while cephalosporin MICs were unaffected. Genetic analysis revealed that
bla
OXA-235
,
bla
OXA-236
, and
bla
OXA-237
were bracketed between two IS
Aba1
insertion sequences. In addition, the presence of these acquired β-lactamase genes might result from a transposition-mediated mechanism. This highlights the propensity of
A. baumannii
to acquire multiple carbapenem resistance determinants.
A Heterologous Prime-Boost Vaccination Strategy Comprising the Francisella tularensis Live Vaccine StraincapBMutant and Recombinant Attenuated Listeria monocytogenes Expressing F. tularensis IglC Induces Potent Protective Immunity in Mice against Virulent F. tularensis Aerosol Challenge
Authors: Jia Qingmei , Bowen Richard , Sahakian Jacob , Dillon Barbara Jane , Horwitz Marcus A.
Published: February 2013

Francisella tularensis, the causative agent of tularemia, is a category A bioterrorism agent. A vaccine that is safer and more effective than the currently available unlicensedF. tularensislive vaccine strain (LVS) is needed to protect against intentional release of aerosolizedF. tularensis, the most dangerous type of exposure. In this study, we employed a heterologous prime-boost vaccination strategy comprising intradermally administered LVS ΔcapB(highly attenuatedcapB-deficient LVS mutant) as the primer vaccine and rLm/iglC (recombinant attenuatedListeria monocytogenesexpressing theF. tularensisimmunoprotective antigen IglC) as the booster vaccine. Boosting LVS ΔcapB-primed mice with rLm/iglC significantly enhanced T cell immunity; their splenic T cells secreted significantly more gamma interferon (IFN-γ) and had significantly more cytokine (IFN-γ and/or tumor necrosis factor [TNF] and/or interleukin-2 [IL-2])-producing CD4+and CD8+T cells uponin vitroIglC stimulation. Importantly, mice primed with LVS ΔcapBor rLVS ΔcapB/IglC, boosted with rLm/iglC, and subsequently challenged with 10 50% lethal doses (LD50) of aerosolized highly virulentF. tularensisSchu S4 had a significantly higher survival rate and mean survival time than mice immunized with only LVS ΔcapB(P< 0.0001); moreover, compared with mice immunized once with LVS, primed-boosted mice had a higher survival rate (75% versus 62.5%) and mean survival time during the first 21 days postchallenge (19 and 20 days for mice boosted after being primed with LVS ΔcapBand rLVS ΔcapB/IglC, respectively, versus 17 days for mice immunized with LVS) and maintained their weight significantly better (P< 0.01). Thus, the LVS ΔcapB-rLm/iglC prime-boost vaccination strategy holds substantial promise for a vaccine that is safer and at least as potent as LVS.
Large Gartner cyst
Authors: Inocêncio Gonçalo , Azevedo Sara , Braga António , Carinhas Maria João
Published: February 2013

Gartner cyst is usually an asymptomatic vaginal cyst, measuring less than 2 cm, frequently found during a routine gynaecological examination. Very rarely, as these cysts are closed structures, they may increase in size because of mucus production. We describe here a case of a large Gartner cyst of approximately 8 cm, its differential diagnosis, investigation and vaginal surgical approach (with illustrations), that progressed uneventfully.
Absence of aneuploidy and gastrointestinal tumours in a man with a chromosomal 2q13 deletion andBUB1monoallelic deficiency
Authors: Hoang Don , Sue Gloria R , Xu Fang , Li Peining , Narayan Deepak
Published: February 2013

Chromosomal instability is a potentially critical step in the development of colorectal cancer. The budding uninhibited by benzimidazole 1 (BUB1) gene is a highly conserved protein that plays a critical role at the spindle assembly checkpoint during cell division.BUB1mutations function in a dominant-negative fashion and have been implicated in causing dysfunctional kinetochore attachments, premature chromatid separation, accelerated mis-segregation of whole chromosomes and aneuploidy.BUB1mutations have been observed in patients with colorectal cancers. We report a remarkable case ofBUB1haploinsufficiency owing to a 1.7 Mb deletion of chromosome 2q13 in a 54-year-old man with no prior history of carcinoma. These mutant alleles were observed in both tissue from the hand and peripheral blood. Aneuploidy was not observed on cytogenetic analysis. These findings highlight the insufficiency ofBUB1haploinsufficiency to directly stimulate tumourigenesis, and suggest that other factors may be more critical to this process.
Fibrolipoma of the eustachian ostium
Authors: Thakur J S , Saluja Manika , Sharma Dev Raj , Mohindroo N K
Published: February 2013

Nasopharyngeal fibrolipoma is extremely rare, with only four case reports in the literature. However, lipoma of the eustachian tube is the rarest with a single case report in the literature. A 50-year-old woman presented with obstruction of both nostrils for the past 1 year. CT scan showed a mass in the postnasal space extending from the right side of the nasopharynx to the oropharynx. The nasal endoscopy found a polypoidal mass arising from the posterior–inferior margin of the right eustachian tube ostium and extending to the oropharynx. Histopathological examination of the excised polyp found features suggestive of fibrolipoma. Fibrolipoma is characterised by prominent bundles of mature collagenous or myxocollagenous stroma intermixed with mature adipocytes. CT is useful in the diagnosis of lipoma but MRI is preferable. This is the second case of eustachian tube fibrolipoma to be reported in the literature that emphasises the role of nasal endoscopy and rarity of this tumour.
Brain abscess as an initial presentation in a patient of hereditary haemorrhagic telangiectasia caused by a novelENGmutation
Authors: Chen Kai-Hsiang , Lin Chin-Hsien
Published: February 2013

Hereditary haemorrhagic telangiectasia (HHT) is a rare inherited autosomal-dominant vascular dysplasia involving multiple organs. Brain abscess is an uncommon and potential fatal complication. We report a case of HHT caused by a novelENGmutation who initially presented as brain abscess. The patient, with a family history of epistaxis, presented with fever, headache and right-sided haemiparesis. Upon examination, brain MRI showed a contrast-enhanced abscess on the left fronto-parietal region. Open brain drainage was performed and pus culture yieldedActinomyces meyeri. The chest image revealed multiple pulmonary arterio-venous fistulas. HHT was diagnosed according to Curacao criteria. Genetic analysis revealed a novel duplication on exon 6 ofENGgene, which segregates with symptomatic subjects in her family. Clinicians should be cautiously aware of HHT as a differential diagnosis if patients presented with an unknown entry source of intracerebral infections.
To invade or not to invade: two approaches to a prokaryotic predatory life cycle
Authors: Chanyi Ryan M. , Ward Caitlin , Pechey Andrea , Koval Susan F.
Published: February 2013

Bdellovibrio and like organisms (BALOs) are a group of Gram-negative bacterial predators that are defined as having a periplasmic life cycle, whereby the predator enters into the periplasm of a prey cell. Recently, a predator of Caulobacter crescentus with a novel epibiotic life cycle was identified as a new species — Bdellovibrio exovorus. Therefore, this raises the question as to what determines the type of life cycle of a predator. Six bacterial strains susceptible to predation by B. exovorus JSS were isolated from soil, sewage, and activated sludge. 16S rRNA gene sequence analysis revealed these prey cells to be Acinetobacter johnsonii, Acinetobacter junii, Aeromonas hydrophila, and Delftia acidovorans. The life cycle of B. exovorus was epibiotic on all these prey cells. Environmental samples were enriched with these prey cells; new BALOs were isolated and their life cycle assessed. All new isolates had a periplasmic life cycle. BALOs generally have diverse prey ranges, and thus, not all new prey cells could be used by each new predator. Overall, each prey cell was able to support the growth of predators with either life cycle. Therefore it was confirmed that it is the predator and not the prey that determines the type of life cycle.
GRADIENT SCHEMES: A GENERIC FRAMEWORK FOR THE DISCRETISATION OF LINEAR, NONLINEAR AND NONLOCAL ELLIPTIC AND PARABOLIC EQUATIONS
Authors: DRONIOU JEROME , EYMARD ROBERT , GALLOUET THIERRY , HERBIN RAPHAELE
Published: February 2013

Gradient schemes are nonconforming methods written in discrete variational formulation and based on independent approximations of functions and gradients, using the same degrees of freedom. Previous works showed that several well-known methods fall in the framework of gradient schemes. Four properties, namely coercivity, consistency, limit-conformity and compactness, are shown in this paper to be sufficient to prove the convergence of gradient schemes for linear and nonlinear elliptic and parabolic problems, including the case of nonlocal operators arising for example in image processing. We also show that the schemes of the Hybrid Mimetic Mixed family, which include in particular the Mimetic Finite Difference schemes, may be seen as gradient schemes meeting these four properties, and therefore converges for the class of above-mentioned problems.
NANOSEEDING EFFECT IN ZSM-5 CRYSTALLIZATION PROCESS
Authors: LU YI , ZHANG NAI-QIAN , TONG QIN , LIU JIN-KU , HONG DAN-JING
Published: February 2013

ZSM-5 zeolites were hydrothermally synthesized in three different seeding pathways under the direction of tetrapropylammonium bromide (TPABr) template. In order to investigate the seeding effect in ZSM-5 crystallization process, ZSM-5 crystals and pre-fabricated MFI-type nanoseeds were added into the original self-induction system, respectively. The final ZSM-5 zeolites were systematically investigated based on XRD (X-ray diffraction), SEM (scanning electron micrograph), TEM (transmission electron micrograph), nitrogen adsorption characterizations and NH3 -TPD (ammonia-temperature programmed desorption). The self-induction system produced ca. 20 μm ZSM-5 zeolite displaying hexagonally uniform prisms. After the addition of ZSM-5 crystal seeds, the crystal sizes were decreased greatly to ca. 5 μm. When MFI-type nanoseeds were adopted, irregular aggregate particles consisting of 20–50 nm primary particles were rapidly synthesized. The varied hydrothermal crystallization kinetics of the three synthesis system was also explored. Adjusting the seed agents alone, ZSM-5 crystals with diverse structural, morphological, textural and hydrothermal behaviors could be fabricated conveniently. The three ZSM-5 zeolites loaded by 0.05 wt.% Pt were assessed for the xylene isomerization reaction to investigate the particle size effect on the catalytic properties.
TiO2 HOLLOW SPHERES: ONE-POT SYNTHESIS AND ENHANCED PHOTOCATALYSIS
Authors: JIA CHANGCHAO , CAO YONGQIANG , YANG PING
Published: February 2013

Hollow TiO2 microspheres were successfully fabricated by metal salts with low solubility in ethanol acting as intelligent templates using a simple one-pot solvothermal method. Hollow spheres with large diameter were obtained using CuSO4⋅5H2O as templates while small ones were obtained using Sr(NO3)2 as templates. It is found that titanium precursor plays an important role for the morphology of samples. Solid TiO2 microspheres were prepared by using titanium tetrabutoxide (TBT). In contrast, bowl-like hollow microspheres were obtained by using titanium tetrachloride (TiCl4) . Furthermore, the amount of H2O can stimulate the hydrolysis rate of TiCl4 to form solid spheres. Compared with solid microspheres, hollow TiO2 microspheres depending on their interior cavity structure exhibited enhanced photocatalysis efficiency for the UV-light photodegradation of methyl orange. Quantificationally, the apparent photocatalytic degradation pseudo-first-rate constant of the hollow microspheres is 1.25 times of that of the solid ones.
Probing the Hepatic Progenitor Cell in Human Hepatocellular Carcinoma
Authors: Jia Shu-Qin , Ren Jian-Jun , Dong Pei-De , Meng Xing-Kai
Published: February 2013

Objective. The intrahepatic stem cells, also known as hepatic progenitor cells (HPCs), are able to differentiate into hepatocytes and bile duct epithelia. By exposure of different injuries and different hepatocarcinogenic regimens, the mature hepatocytes can no longer effectively regenerate; stem cells are involved in the pathogenesis of hepatocellular carcinoma.Methods. Immunohistochemistry was performed on 107 paraffin-embedded hepatocellular carcinoma specimens with the marker of hepatocyte and hepatocellular carcinoma (HepPar1), biliary differentiation (CK7,CK19), haemopoietic stem cell (HSC) (c-kit/CD117, CD34, and Thy-1/CD90), HPC specific markers (OV-6), and Ki-67, p53 protein.Results. HPCs can be identified in the tumor nodules, around the edge of tumor nodules, and in the portal tracts of the paracirrhosis nodules being positive in HepPar1, CK7, CK19, and OV-6, but they failed to immunostain with CD117, CD34, and CD90. The HPCs positive in Ki-67 are observed in the tumor and paracirrhosis tissues. In 107 specimens, 40.2% (43/107) HCC tissues expressed p53 protein, lower than that of the HPCs around the tumor nodules (46.7%, 50/107) and much higher than that of the HPCs around the paracirrhosis nodules (8.41%, 9/107).Conclusion. Human hepatocellular carcinogenesis may be based on transformation of HPCs, not HSCs, through the formation of the transitional cells (hepatocyte-like cells and bile ductal cells).
Working Memory Training in Patients with Chronic Schizophrenia: A Pilot Study
Authors: Hubacher Martina , Weiland Marcus , Calabrese Pasquale , Stoppe Gabriela , Stöcklin Markus , Fischer-Barnicol David , Opwis Klaus , Penner Iris-Katharina
Published: February 2013

Background. There is evidence that patients with schizophrenia suffer from decline in working memory performance with consequences for psychosocial outcome.Objective. To evaluate the efficacy of a computerized working memory training program (BrainStim) in patients with chronic schizophrenia.Methods. Twenty-nine inpatients with chronic schizophrenia were assigned to either the intervention group receiving working memory training (N=15) or the control group without intervention (N=14). Training was performed four times a week for 45 minutes during four weeks under neuropsychological supervision. At baseline and followup all participants underwent neuropsychological testing.Results. Pre-post comparisons of neuropsychological measures showed improvements in visual and verbal working memories and visual short-term memory with small and large effect sizes in the intervention group. In contrast, the control group showed decreased performance in verbal working memory and only slight changes in visual working memory and visual and verbal short-term memories after 4 weeks. Analyses of training profiles during application ofBrainStimrevealed increased performance over the 4-week training period.Conclusions. The applied training toolBrainStimimproved working memory and short-term memory in patients with chronic schizophrenia. The present study implies that chronic schizophrenic patients can benefit from computerized cognitive remediation training of working memory in a clinical setting.
Using Microseismicity to Estimate Formation Permeability for Geological Storage of CO2
Authors: Angus D. A. , Verdon J. P.
Published: February 2013

We investigate two approaches for estimating formation permeability based on microseismic data. The two approaches differ in terms of the mechanism that triggers the seismicity: pore-pressure triggering mechanism and the so-called seepage-force (or effective stress) triggering mechanism. Based on microseismic data from a hydraulic fracture experiment using water and supercritical CO2 injection, we estimate permeability using the two different approaches. The microseismic data comes from two hydraulic stimulation treatments that were performed on two formation intervals having similar geological, geomechanical, and in situ stress conditions, yet different injection fluid was used. Both approaches (pore-pressure triggering, and the seepage-force triggering) provide estimates of permeability within the same order of magnitude. However, the seepage-force mechanism (i.e., effective stress perturbation) provides more consistent estimates of permeability between the two different injection fluids. The results show that permeability estimates using microseismic monitoring have strong potential to constrain formation permeability limitations for large-scale CO2 injection.
A Preliminary Study of Banana Stem Juice as a Plant‐Based Coagulant for Treatment of Spent Coolant Wastewater
Authors: Alwi Habsah , Idris Juferi , Musa Mohibah , Ku Hamid Ku Halim
Published: February 2013

The effectiveness of banana stem juice as a natural coagulant for treatment of spent coolant wastewater was investigated . Three main parameters were studied, namely, chemical oxygen demand (COD), suspended solids (SSs), and turbidity of effluent. Coagulation experiments using jar test were performed with a flocculation system where the effects of spent coolant wastewater pH as well as banana stem juice dosage on coagulation effectiveness were examined. The highest recorded COD, SS, and turbidity removal percentages by banana stem juice were 80.1%, 88.6%, and 98.5%, respectively, observed for effluent at pH 7 using 90 mL dosage. The inulin concentration in the banana stem was examined to be 1.22016 mg/mL. It could be concluded that banana stem juice showed tremendous potential as a natural coagulant for water treatment purposes and could be applied in the pretreatment stage of Malaysian spent coolant wastewater prior to secondary treatment.
Estimation of Observer Parameters for Dynamic Positioning Ships
Authors: Lin Xiaogong , Xie Yehai , Zhao Dawei , Xu Shusheng
Published: February 2013

Considering the problem of dynamic positioning systems for the slowly varying disturbances, a parametrically adaptive observer is presented. The peak frequency of observer is adjusted on-line by autoregressive (AR) spectral estimation; other parameters of observer are optimized using particle swarm optimization (PSO). The peak frequency can be calculated by spectral analysis of the pitch, roll, and heave measurements. In the spectral estimation, Levinson-Durbin algorithm is used to solve the Yule-Walker equations. Finally, the computer simulation is given to demonstrate the effectiveness of the proposed method.
Out on the Land: Income, Subsistence Activities, and Food Sharing Networks in Nain, Labrador
Authors: Dombrowski Kirk , Channell Emily , Khan Bilal , Moses Joshua , Misshula Evan
Published: February 2013

In recent Inuit ethnography, a major concern has been how and to what extent contemporary Inuit participate in and depend on subsistence activities, particularly in the context of increasing wage employment and growing participation in the cash economy. This paper provides an analysis of these activities in the predominately Inuit community of Nain, Labrador. Using social network data and demographic information collected between January and June 2010, we examine the interconnections between subsistence activities—obtaining “country food” through activities such as hunting, fishing, and collecting—with access to the means of obtaining subsistence resources (such as snow mobiles, cabins, and boats), employment status, and income. Our data indicate that individuals with higher employment status and income tend to be more central to the network of subsistence food sharing, but not because they have greater access to hunting tools or equipment (they do not). We conclude that those individuals who play the most central role in the network are those who are financially able to do so, regardless of access to hunting tools/means.
Investigating the Formation Process of Sn‐Based Lead‐Free Nanoparticles with a Chemical Reduction Method
Authors: Zhang Weipeng , Zhao Bingge , Zou Changdong , Zhai Qijie , Gao Yulai , Acquah Steve F. A.
Published: February 2013

Nanoparticles of a promising lead‐free solder alloy (Sn3.5Ag (wt.%, SnAg) and Sn3.0Ag0.5Cu (wt.%, SAC)) were synthesized through a chemical reduction method by using anhydrous ethanol and 1,10‐phenanthroline as the solvent and surfactant, respectively. To illustrate the formation process of Sn‐Ag alloy based nanoparticles during the reaction, X‐ray diffraction (XRD) was used to investigate the phases of the samples in relation to the reaction time. Different nucleation and growth mechanisms were compared on the formation process of the synthesized nanoparticles. The XRD results revealed different reaction process compared with other researchers. There were many contributing factors to the difference in the examples found in the literature, with the main focus on the formation mechanism of crystal nuclei, the solubility and ionizability of metal salts in the solvent, the solid solubility of Cu in Ag nuclei, and the role of surfactant on the growth process. This study will help define the parameters necessary for the control of both the composition and size of the nanoparticles.
Unattended Home Labor until Complete Cervical Dilatation Ending with Hospital Delivery: Analysis of 238 Pregnancies
Authors: Gun Eryilmaz Ozlem , Dogan Nasuh Utku , Gulerman Cavidan , Mollamahmutoglu Leyla , Cicek Nedim , Deveer Ruya
Published: February 2013

Objectives. Hospital fear and avoidance of the routine hospital obstetrical interventions cause some women with low-risk pregnancies to spend most of the active labor period at home, and subsequently they present to the hospital for delivery. Our aim was to analyze the maternal and neonatal outcomes of pregnancies with a planned hospital birth, yet spending the first stage of labor at home without a health provider and completing the delivery in the hospital setting.Methods. We retrospectively compared 238 pregnancies having home labor plus hospital delivery (study group) with 476 pregnancies that had spent the whole labor in the hospital setting, considering various maternal and neonatal outcomes.Results. Cesarean and episiotomy rates were lower (P<0.0001andP<0.001, resp.), but neonatal intensive care unit admissions of the infants were more prevalent (P<0.01) in the study group. Other maternal and neonatal outcomes including neonatal mortality were comparable.Conclusion. Although our preliminary data generally do support the safety of home active labor plus hospital delivery for low-risk pregnancies, the clinical implications of current data warrant further prospective trials.
Acute Renal Failure and Volume Overload Syndrome Secondary to a Femorofemoral Arteriovenous Fistula Angioplasty in a Kidney Transplant Recipient
Authors: Bertrand Dominique , Desbuissons Geoffroy , Pallet Nicolas , Sartorius Albane , Legendre Christophe , Mamzer Marie-France , Sberro Soussan Rebecca
Published: February 2013

Experimental and clinical studies analyzing the impact of AVF on cardiovascular and renal parameters, as well as outcomes, in kidney transplant recipients are lacking. On the other hand, it is not known whether AVF ligation after transplantation modifies hemodynamic parameters and kidney function. We report a case of a renal transplant recipient who developed an acute congestive heart failure accompanied by renal failure, which were triggered by femorofemoral AVF angioplasty. Prompt AVF ligation rapidly reversed clinical symptoms and normalized cardiac and renal functions. This paper illustrates the potential deleterious consequences of high-output AVF after kidney transplantation and raises considerations regarding the impact of the fistula on cardiac status and kidney function after kidney transplantation and, consequently, the management AVF after transplantation.
Molecular Imaging Probes for Diagnosis and Therapy Evaluation of Breast Cancer
Authors: Meng Qingqing , Li Zheng
Published: February 2013

Breast cancer is a major cause of cancer death in women where early detection and accurate assessment of therapy response can improve clinical outcomes. Molecular imaging, which includes PET, SPECT, MRI, and optical modalities, provides noninvasive means of detecting biological processes and molecular eventsin vivo.Molecular imaging has the potential to enhance our understanding of breast cancer biology and effects of drug action during both preclinical and clinical phases of drug development. This has led to the identification of many molecular imaging probes for key processes in breast cancer. Hormone receptors, growth factor receptor, and angiogenic factors, such as ER, PR, HER2, and VEGFR, have been adopted as imaging targets to detect and stage the breast cancer and to monitor the treatment efficacy. Receptor imaging probes are usually composed of targeting moiety attached to a signaling component such as a radionuclide that can be detected using dedicated instruments. Current molecular imaging probes involved in breast cancer diagnosis and therapy evaluation are reviewed, and future of molecular imaging for the preclinical and clinical is explained.
Extrahepatic Textiloma Long Misdiagnosed as Calcified Echinococcal Cyst
Authors: Cattaneo Federico , Graffeo Massimo , Brunetti Enrico
Published: February 2013

Textiloma or gossypiboma is a retained surgical swab in the body after an operation and is a complication that can remain undetected for many years and may represent a diagnostic dilemma depending on its location. It may be confused with several focal lesions and an accurate history taking, combined with clinical and instrumental data, is key to suspecting the diagnosis. We report a case of abdominal textiloma that was initially misdiagnosed as echinococcal cyst and discuss the differential diagnosis based on sonographic features and the WHO-IWGE classification.
The Radial Distribution Functions of Water as Derived from Radiation Total Scattering Experiments: Is There Anything We Can Say for Sure?
Authors: Soper A. K.
Published: February 2013

The present paper reviews the investigation of ambient water structure and focusses in particular on the determination of the radial distribution functions of water from total experimental radiation
scattering experiments. A novel method for removing the inelastic scattering from neutron data is introduced, and the effect of Compton scattering on X-ray data is discussed. In addition the extent to which quantum effects can be discerned between heavy and light water is analysed against these more recent data. It is concluded that, with the help of modern data analysis and computer simulation tools to interrogate the scattering data, a considerable degree of consistency can be obtained between recent and past scattering experiments on water. That consistency also gives a realistic estimate of the likely uncertainties in the extracted radial distribution functions, as well as offering a benchmark against which future experiments can be judged.
Phage Display Screening for Tumor Necrosis Factor-α-Binding Peptides: Detection of Inflammation in a Mouse Model of Hepatitis
Authors: Sclavons Coralie , Burtea Carmen , Boutry Sébastien , Laurent Sophie , Vander Elst Luce , Muller Robert N.
Published: February 2013

TNF-αis one of the most abundant cytokines produced in many inflammatory and autoimmune conditions such as multiple sclerosis, chronic hepatitis C, or neurodegenerative diseases. These pathologies remain difficult to diagnose and consequently difficult to treat. The aim of this work is to offer a new diagnostic tool by seeking new molecular probes for medical imaging. The target-specific part of the probe consists here of heptameric peptides selected by the phage display technology for their affinity for TNF-α. Several affinity tests allowed isolating 2 peptides that showed the best binding capacity to TNF-α. Finally, the best peptide was synthesized in both linear and cyclic forms and tested on the histological sections of concanavalin-A-(ConA-)treated mice liver. In this well-known hepatitis mouse model, the best results were obtained with the cyclic form of peptide 2, which allowed for the staining of inflamed areas in the liver. The cyclic form of peptide 2 (2C) was, thus, covalently linked to iron oxide nanoparticles (magnetic resonance imaging (MRI) contrast agent) and tested in the ConA-induced hepatitis mouse model. The vectorized nanoparticles allowed for the detection of inflammation as well as of the free peptide. Theseex vivoresults suggest that phage display-selected peptides can direct imaging contrast agents to inflammatory areas.