bluuebunny/crossref_metadata_2025 huggingface dataset:
Visual scanning as a reference framework for interactive representation design
Authors: Conversy Stéphane , Chatty Stéphane , Hurter Christophe
Published: July 2011

When designing a representation, the designer implicitly formulates a sequence of visual tasks required to understand and use the representation effectively. This paper aims at making the sequence of visual tasks explicit in order to help designers elicit their design choices. In particular, we present a set of concepts to systematically analyse what a user must theoretically do to decipher representations. The analysis consists of a decomposition of the activity of scanning into elementary visualization operations. We show how the analysis applies to various existing representations, and how expected benefits can be expressed in terms of elementary operations. The set of elementary operations form the basis of a shared language for representation designers. The decomposition highlights the challenges encountered by a user when deciphering a representation and helps designers to exhibit possible flaws in their design, justify their choices, and compare designs. We also show that interaction with a representation can be considered as facilitation to perform the elementary operations.

Categories and subject descriptors

H.5.2 User Interfaces – evaluation/methodology, screen design.

General terms

design, human factors
Neurophysiological and Behavioral Effects of tDCS Combined With Constraint-Induced Movement Therapy in Poststroke Patients
Authors: Bolognini Nadia , Vallar Giuseppe , Casati Carlotta , Latif Lydia Abdul , El-Nazer Rasheda , Williams Julie , Banco Elisabetta , Macea Debora Duarte , Tesio Luigi , Chessa Cecilia , Fregni Felipe
Published: July 2011

Background. Recovery of motor function after stroke may depend on a balance of activity in the neural network involving the affected and the unaffected motor cortices. Objective. To assess whether transcranial direct current stimulation (tDCS) can increase the training-induced recovery of motor functions. Methods. In an exploratory study, 14 patients with chronic stroke and mean Fugl-Meyer Upper Extremity Motor Assessment of 29 (range = 8-50) entered a double-blind sham-controlled study, aimed to investigate neurophysiological and behavioral effects of bihemispheric tDCS (cathodal stimulation of the unaffected motor cortex and anodal stimulation of the affected motor cortex), combined with constraint-induced movement therapy (CIMT). Results. Patients in both groups demonstrated gains on primary outcome measures, that is, Jebsen Taylor Hand Function Test, Handgrip Strength, Motor Activity Log Scale, and Fugl-Meyer Motor Score. Gains were larger in the active tDCS group. Neurophysiological measurements showed a reduction in transcallosal inhibition from the intact to the affected hemisphere and increased corticospinal excitability in the affected hemisphere only in the active tDCS/CIMT group. Such neurophysiological changes correlated with the magnitude of the behavioral gains. Both groups showed a reduction in corticospinal excitability of the unaffected hemisphere. Conclusions. CIMT alone appears effective in modulating local excitability but not in removing the imbalance in transcallosal inhibition. Bihemispheric tDCS may achieve this goal and foster greater functional recovery.
CCL18 differentiates dendritic cells in tolerogenic cells able to prime regulatory T cells in healthy subjects
Authors: Azzaoui Imane , Yahia Saliha Ait , Chang Ying , Vorng Han , Morales Olivier , Fan Ying , Delhem Nadira , Ple Coline , Tonnel André-Bernard , Wallaert Benoit , Tsicopoulos Anne
Published: July 2011

The aim of this study was to evaluate the nonchemotactic function of CCL18 on human dendritic cells (DCs). In different protocols of DC differentiation, CCL18 was highly produced, suggesting that it may constitute a mandatory mediator of the differentiation process. Differentiation of monocytes from healthy subjects in the presence of granulocyte-macrophage colony-stimulating factor and CCL18 led to the development of DCs with a semimature phenotype, with intermediate levels of costimulatory and MHC class II molecules, increased CCR7 expression, which induced, in coculture with allogenic naive T cells, an increase in IL-10 production. The generated T cells were able to suppress the proliferation of effector CD4+CD25− cells, through a cytokine-dependent mechanism, and exhibited characteristics of type 1 T regulatory cells. The generation of tolerogenic DCs by CCL18 was dependent on the production of indoleamine 2,3-dioxigenase through an interleukin-10-mediated mechanism. Surprisingly, when DCs originated from allergic patients, the tolerogenic effect of CCL18 was lost in relation with a decreased binding of CCL18 to its putative receptor. This study is the first to define a chemokine able to generate tolerogenic DCs. However, this function was absent in allergic donors and may participate to the decreased tolerance observed in allergic diseases.
Biphasic roles for soluble guanylyl cyclase (sGC) in platelet activation
Authors: Zhang Guoying , Xiang Binggang , Dong Anping , Skoda Radek C. , Daugherty Alan , Smyth Susan S. , Du Xiaoping , Li Zhenyu
Published: July 2011

Nitric oxide (NO) stimulates cGMP synthesis by activating its intracellular receptor, soluble guanylyl cyclase (sGC). It is a currently prevailing concept that No and cGMP inhibits platelet function. However, the data supporting the inhibitory role of NO/sGC/cGMP in platelets have been obtained either in vitro or using whole body gene deletion that affects vessel wall function. Here we have generated mice with sGC gene deleted only in megakaryocytes and platelets. Using the megakaryocyte- and platelet-specific sGC-deficient mice, we identify a stimulatory role of sGC in platelet activation and in thrombosis in vivo. Deletion of sGC in platelets abolished cGMP production induced by either NO donors or platelet agonists, caused a marked defect in aggregation and attenuated secretion in response to low doses of collagen or thrombin. Importantly, megakaryocyte- and platelet-specific sGC deficient mice showed prolonged tail-bleeding times and impaired FeCl3-induced carotid artery thrombosis in vivo. Interestingly, the inhibitory effect of the NO donor SNP on platelet activation was sGC-dependent only at micromolar concentrations, but sGC-independent at millimolar concentrations. Together, our data demonstrate important roles of sGC in stimulating platelet activation and in vivo thrombosis and hemostasis, and sGC-dependent and -independent inhibition of platelets by NO donors.
Effects of two Lactobacillus strains on lipid metabolism and intestinal microflora in rats fed a high-cholesterol diet
Authors: Xie Ning , Cui Yi , Yin Ya-Ni , Zhao Xin , Yang Jun-Wen , Wang Zheng-Gen , Fu Nian , Tang Yong , Wang Xue-Hong , Liu Xiao-Wei , Wang Chun-Lian , Lu Fang-Gen
Published: July 2011

Background

The hypocholesterolemic effects of lactic acid bacteria (LAB) have now become an area of great interest and controversy for many scientists. In this study, we evaluated the effects ofLactobacillus plantarum9-41-A andLactobacillus fermentumM1-16 on body weight, lipid metabolism and intestinal microflora of rats fed a high-cholesterol diet.

Methods

Forty rats were assigned to four groups and fed either a normal or a high-cholesterol diet. The LAB-treated groups received the high-cholesterol diet supplemented withLactobacillus plantarum9-41-A orLactobacillus fermentumM1-16. The rats were sacrificed after a 6-week feeding period. Body weights, visceral organ and fat pad weights, serum and liver cholesterol and lipid levels, and fecal cholesterol and bile acid concentrations were measured. Liver lipid deposition and adipocyte size were evaluated histologically.

Results

Compared with rats fed a high-cholesterol diet but without LAB supplementation, serum total cholesterol, low-density lipoprotein cholesterol and triglycerides levels were significantly decreased in LAB-treated rats (p < 0.05), with no significant change in high-density lipoprotein cholesterol levels. Hepatic cholesterol and triglyceride levels and liver lipid deposition were significantly decreased in the LAB-treated groups (p < 0.05). Accordingly, both fecal cholesterol and bile acids levels were significantly increased after LAB administration (p < 0.05). IntestinalLactobacillusandBifidobacteriumcolonies were increased whileEscherichia colicolonies were decreased in the LAB-treated groups. Fecal water content was higher in the LAB-treated groups. Compared with rats fed a high-cholesterol diet, administration ofLactobacillus plantarum9-41-A resulted in decreases in the body weight gain, liver and fat pad weight, and adipocytes size (p < 0.05).

Conclusions

This study suggests that LAB supplementation has hypocholesterolemic effects in rats fed a high-cholesterol diet. The ability to lower serum cholesterol varies among LAB strains. Our strains might be able to improve the intestinal microbial balance and potentially improve intestinal transit time. Although the mechanism is largely unknown,L. plantarum9-41-A may play a role in fat metabolism.
Heteroarylketones inhibit astroglial interleukin-6 expression via a STAT3/NF-κB signaling pathway
Authors: Schulz Ingo , Engel Claudia , Niestroj André J , Zeitschel Ulrike , Menge Katja , Kehlen Astrid , Meyer Antje , Roßner Steffen , Demuth Hans-Ulrich
Published: July 2011

Background

Elevated brain levels of the pleiotropic cytokine interleukin-6, which is mainly secreted from activated local astrocytes, contribute to pathological events including neuroinflammation and neurodegeneration. Thus, inhibition of pathological IL-6 expression provides a rationale strategy for targeting the onset or further progression of neurological disorders including Alzheimer's disease, multiple sclerosis, Parkinson's disease and traumatic brain injury. The purpose of this study was to identify and to characterize new potent inhibitors of astrocytic IL-6 expression for further therapeutic development of novel anti-inflammatory and neuroprotective drugs.

Methods

Oncostatin M (OSM)-treated human glioma U343 cells were used as model for induction of astrocytic IL-6 expression. This model was characterized by immunoblotting, siRNA technique, ELISA and qRT-PCR and used to screen low molecular weight compound libraries for IL-6-lowering effects. To validate bioactive compounds identified from library screens, bacterial lipopolysaccharide was used to induce IL-6 expression in cultivated primary astrocytes and in micein vivo. To dissect underlying molecular mechanisms, protein extracts from OSM-treated U343 cells were analyzed by phospho-specific immunoblotting and immunocytochemistry as well as by co-immunoprecipitation.

Results

OSM-treatment (100 ng/ml; 24 h) led to 30-fold increase of IL-6 secretion from U343 cells. The temporal profile of IL-6 mRNA induction displayed a biphasic induction pattern with peak synthesis at 1 h (6.5-fold) and 16 h (5.5-fold) post stimulation. IL-6 protein release did not show that biphasic pattern and was detected as early as 3 h post stimulation reaching a maximum at 24 h. The screen of compound libraries identified a set of heteroarylketones (HAKs) as potent inhibitors of IL-6 secretion. HAK compounds affected the second peak in IL-6 mRNA synthesis, whereas the first peak was insensitive to HAK treatment. HAK compounds also suppressed lipopolysaccharide-induced IL-6 expression in primary murine astrocytes as well as in brain and plasma samples from lipopolysaccharide-treated mice. Finally, HAK compounds were demonstrated to specifically suppress the OSM-induced phosphorylation of STAT3 at serine 727 and the physical interaction of pSTAT3S727with p65.

Conclusion

Heteroarylketone compounds are potent inhibitors of IL-6 expressionin vitroandin vivoand may represent a new class of potent anti-inflammatory and neuroprotective drugs.
The accuracy of echocardiography versus surgical and pathological classification of patients with ruptured mitral chordae tendineae: a large study in a Chinese cardiovascular center
Authors: Wu Weichun , Luo Xiaoliang , Wang Linlin , Sun Xin , Jiang Yong , Huo Shunwei , Tu Dalou , Bai Zhigang , Wang Hao
Published: July 2011

Background

The accuracy of echocardiography versus surgical and pathological classification of patients with ruptured mitral chordae tendineae (RMCT) has not yet been investigated with a large study.

Methods

Clinical, hemodynamic, surgical, and pathological findings were reviewed for 242 patients with a preoperative diagnosis of RMCT that required mitral valvular surgery. Subjects were consecutive in-patients at Fuwai Hospital in 2002-2008. Patients were evaluated by thoracic echocardiography (TTE) and transesophageal echocardiography (TEE). RMCT cases were classified by location as anterior or posterior, and classified by degree as partial or complete RMCT, according to surgical findings. RMCT cases were also classified by pathology into four groups: myxomatous degeneration, chronic rheumatic valvulitis (CRV), infective endocarditis and others.

Results

Echocardiography showed that most patients had a flail mitral valve, moderate to severe mitral regurgitation, a dilated heart chamber, mild to moderate pulmonary artery hypertension and good heart function. The diagnostic accuracy for RMCT was 96.7% for TTE and 100% for TEE compared with surgical findings. Preliminary experiments demonstrated that the sensitivity and specificity of diagnosing anterior, posterior and partial RMCT were high, but the sensitivity of diagnosing complete RMCT was low. Surgical procedures for RMCT depended on the location of ruptured chordae tendineae, with no relationship between surgical procedure and complete or partial RMCT. The echocardiographic characteristics of RMCT included valvular thickening, extended subvalvular chordae, echo enhancement, abnormal echo or vegetation, combined with aortic valve damage in the four groups classified by pathology. The incidence of extended subvalvular chordae in the myxomatous group was higher than that in the other groups, and valve thickening in combination with AV damage in the CRV group was higher than that in the other groups. Infective endocarditis patients were younger than those in the other groups. Furthermore, compared other groups, the CRV group had a larger left atrium, higher aortic velocity, and a higher pulmonary arterial systolic pressure.

Conclusions

Echocardiography is a reliable method for diagnosing RMCT and is useful for classification. Echocardiography can be used to guide surgical procedures and for preliminary determination of RMCT pathological types.
Neuroprotective effect of a new DJ-1-binding compound against neurodegeneration in Parkinson's disease and stroke model rats
Authors: Kitamura Yoshihisa , Watanabe Shotaro , Taguchi Masanobu , Takagi Kentaro , Kawata Takuya , Takahashi-Niki Kazuko , Yasui Hiroyuki , Maita Hiroshi , Iguchi-Ariga Sanae MM , Ariga Hiroyoshi
Published: July 2011

Background

Parkinson's disease (PD) and cerebral ischemia are chronic and acute neurodegenerative diseases, respectively, and onsets of these diseases are thought to be induced at least by oxidative stress. PD is caused by decreased dopamine levels in the substantia nigra and striatum, and cerebral ischemia occurs as a result of local reduction or arrest of blood supply. Although a precursor of dopamine and inhibitors of dopamine degradation have been used for PD therapy and an anti-oxidant have been used for cerebral ischemia therapy, cell death progresses during treatment. Reagents that prevent oxidative stress-induced cell death are therefore necessary for fundamental therapies for PD and cerebral ischemia. DJ-1, a causative gene product of a familial form of PD, PARK7, plays roles in transcriptional regulation and anti-oxidative stress, and loss of its function is thought to result in the onset of PD. Superfluous oxidation of cysteine at amino acid 106 (C106) of DJ-1 renders DJ-1 inactive, and such oxidized DJ-1 has been observed in patients with the sporadic form of PD.

Results

In this study, a compound, comp-23, that binds to DJ-1 was isolated by virtual screening. Comp-23 prevented oxidative stress-induced death of SH-SY5Y cells and primary neuronal cells of the ventral mesencephalon but not that of DJ-1-knockdown SH-SY5Y cells, indicating that the effect of the compound is specific to DJ-1. Comp-23 inhibited the production of reactive oxygen species (ROS) induced by oxidative stress and prevented excess oxidation of DJ-1. Furthermore, comp-23 prevented dopaminergic cell death in the substantia nigra and restored movement abnormality in 6-hydroxyldopamine-injected and rotenone-treated PD model rats and mice. Comp-23 also reduced infarct size of cerebral ischemia in rats that had been induced by middle cerebral artery occlusion. Protective activity of comp-23 seemed to be stronger than that of previously identified compound B.

Conclusions

The results indicate that comp-23 exerts a neuroprotective effect by reducing ROS-mediated neuronal injury, suggesting that comp-23 becomes a lead compound for PD and ischemic neurodegeneration therapies.
Solid variant of aneurysmal bone cyst of the thoracic spine: a case report
Authors: Al-Shamy George , Relyea Katherine , Adesina Adekunle , Whitehead William E , Curry Daniel J , Luerssen Thomas G , Jea Andrew
Published: July 2011

Introduction

The solid variant of aneurysmal bone cyst is rare, and only 13 cases involving the spine have been reported to date, including seven in the thoracic vertebrae. The diagnosis is difficult to secure radiographically before biopsy or surgery.

Case report

An 18-year-old Hispanic man presented to our facility with a one-year history of left chest pain without any significant neurological deficits. An MRI scan demonstrated a 6 cm diameter enhancing multi-cystic mass centered at the T6 vertebral body with involvement of the left proximal sixth rib and extension into the pleural cavity; the spinal cord was severely compressed with evidence of abnormal T2 signal changes. Our patient was taken to the operating room for a total spondylectomy of T6 with resection of the left sixth rib from a single-stage posterior-only approach. The vertebral column was reconstructed in a 360° manner with an expandable titanium cage and pedicle screw fixation. Histologically, the resected specimen showed predominant solid fibroblastic proliferation, with minor foci of reactive osteoid formation, an area of osteoclastic-like giant cells, and cyst-like areas filled with erythrocytes and focal hemorrhage, consistent with a predominantly solid variant of aneurysmal bone cyst. At 16 months after surgery, our patient remains neurologically intact with resolution of his chest and back pain.

Conclusions

Because of its rarity, location, and radical treatment approach, we considered this case worthy of reporting. The solid variant of aneurysmal bone cyst is difficult to diagnose radiologically before biopsy or surgery, and we hope to remind other physicians that it should be included in the differential diagnosis of any lytic expansile destructive lesion of the spine.
Living donor liver transplantation from a donor previously treated with interferon for hepatitis C virus: a case report
Authors: Hidaka Masaaki , Takatsuki Mitsuhisa , Soyama Akihiko , Miyaaki Hisamitsu , Ichikawa Tatsuki , Nakao Kazuhiko , Kanematsu Takashi , Eguchi Susumu
Published: July 2011

Introduction

Selecting a marginal donor in liver transplantation (LT) remains controversial but is necessary because of the small number of available donors.

Case presentation

A 46-year-old Japanese woman was a candidate to donate her liver to her brother, who had decompensated liver cirrhosis of unknown origin. Eight years before the donation, she had a mild liver dysfunction that was diagnosed as a hepatitis C virus (HCV) infection (serotype 2). She had received anti-viral therapy with interferon α-2b three times weekly for 24 weeks and had a sustained viral response (SVR). A biopsy of her liver before the donation showed normal findings without any active hepatitis, and her serum was negative for HCV-RNA. Only 67 patients have undergone LT from a cadaveric donor in Japan. The family in this case decided to have living donor LT. A careful selection for the liver graft donation was made; however, since she was the only candidate, we approved her as a living donor. She was discharged nine days after the liver donation. Her liver function recovered immediately. A computed tomography scan showed sufficient liver regeneration one year later. Her brother also had good liver function after LT and had no HCV infection 48 months after surgery and no de novo malignancy. Neither of the siblings has developed an HCV infection.

Conclusions

A patient with SVR status after interferon therapy might be considered a candidate for living donor LT but only if there are no other possibilities of LT for the recipient. A careful follow-up of the donor after donation is needed. The recipient also must have a very close follow-up because it is difficult to predict what might happen to the graft with post-transplant immunosuppression.
Colonization of Phlebotomus papatasi changes the effect of pre-immunization with saliva from lack of protection towards protection against experimental challenge with Leishmania major and saliva
Authors: Ben Hadj Ahmed Sami , Kaabi Belhassen , Chelbi Ifhem , Cherni Saifeddine , Derbali Mohamed , Laouini Dhafer , Zhioua Elyes
Published: July 2011

Background

Sand fly saliva has been postulated as a potential vaccine or as a vaccine component within multi component vaccine against leishmaniasis. It is important to note that these studies were performed using long-term colonizedPhlebotomus papatasi. The effect of sand flies colonization on the outcome ofLeishmaniainfection is reported.

Results

While pre-immunization of mice with salivary gland homogenate (SGH) of long-term colonized (F5 and beyond) femalePhlebotomus papatasiinduced protection againstLeishmania majorco-inoculated with the same type of SGH, pre-immunization of mice with SGH of recently colonized (F2 and F3) femaleP. papatasidid not confer protection againstL. majorco-inoculated with the same type of SGH. Our data showed for the first time that a shift from lack of protection to protection occurs at the fourth generation (F4) during the colonization process ofP. papatasi.

Conclusion

For the development of a sand fly saliva-based vaccine, inferences based on long-term colonized populations of sand flies should be treated with caution as colonization ofP. papatasiappears to modulate the outcome ofL. majorinfection from lack of protection to protection.
Increasing levels of circulating Th17 cells and interleukin-17 in rheumatoid arthritis patients with an inadequate response to anti-TNF-α therapy
Authors: Chen Der-Yuan , Chen Yi-Ming , Chen Hsin-Hua , Hsieh Chia-Wei , Lin Chi-Chen , Lan Joung-Liang
Published: July 2011

Introduction

The objective of this study was to investigate the effects of tumor necrosis factor (TNF)-α inhibitors on circulating T helper-type 17 (Th17) cells and Th17-related cytokines in patients with rheumatoid arthritis (RA).

Methods

The frequencies of circulating Th17 cells and serum levels of Th17-related cytokines were determined using flow cytometry analysis and ELISA, respectively, in 48 RA patients both before (baseline) and six months after anti-TNF-α therapy. Therapeutic response was evaluated using European League Against Rheumatism (EULAR) response criteria.

Results

Significantly higher baseline frequencies of circulating Th17 cells and serum levels of interleukin (IL)-6, IL-17, IL-21, IL-23 and TNF-α were observed in active RA patients than in 12 healthy controls (all P < 0.001). After anti-TNF-α therapy, 36 patients (75%) were EULAR responders (20 good responders and 16 moderate responders) and 12 (25.0%) were non-responders. The mean levels of circulating Th17 cells and IL-17 significantly decreased (1.13% vs. 0.79%; 43.1 pg/ml vs. 27.8 pg/ml; respectively, both P < 0.001) in parallel with clinical remission in responders. Levels of IL-6, IL-21, IL-23 and TNF-α were significantly decreased after anti-TNF-α therapy in responders. In contrast, the mean levels of circulating Th17 cells and IL-17 significantly increased after anti-TNF-α therapy (2.94% vs. 4.23%; 92.1 pg/ml vs. 148.6 pg/ml; respectively, both P < 0.05) in non-responders. Logistic regression analysis identified a high baseline level of IL-17 as a significant predictor of poor therapeutic response.

Conclusions

The beneficial effect of anti-TNF-α therapy might involve a decrease in Th17-related cytokines in responders, whereas rising levels of circulating Th17-cells and IL-17 were observed in patients with an inadequate response to anti-TNF-α therapy.
Accuracy of CT angiography in the assessment of the circle of Willis: comparison of volume-rendered images and digital subtraction angiography
Authors: Han Ari , Yoon Dae Young , Chang Suk Ki , Lim Kyoung Ja , Cho Byung-Moon , Shin Yoon Cheol , Kim Sam Soo , Kim Keon Ha
Published: July 2011

Background

Computed tomography angiography (CTA) is increasingly used for non-invasive imaging of the cerebrovascular diseases.

Purpose

To evaluate the accuracy of CTA in the assessment of the variation of the segment calibers of the circle of Willis.

Material and Methods

One hundred and 17 patients with acute SAH (51 men and 66 women, mean age 50.9 years) who underwent CTA using a 16 detector-row CT scanner and DSA were evaluated retrospectively. The CTA and DSA studies were performed within 24 h after the onset of symptoms and within 24 h of each other. A total of 819 arterial segments (A-comA, right and left A1 segment, right and left P-com A, and right and left P1 segment) of the circle of Willis were determined to be aplastic (grade 1), hypoplastic (grade 2), or normal-sized (grade 3) by blinded observers evaluating CTA volume-rendered images. The CTA results were then compared with findings on the corresponding DSA images (reference standard).

Results

The overall agreement between CTA and DSA was 92.4%. We had 62 (7.6%) cases of disagreement (58 cases of under-estimation and four cases of over-estimation by CTA) between tow modalities. The sensitivity and specificity of CTA in the detection of aplastic and normal-sized segments were more than 90%. In contrast, subgroup analysis of the hypoplastic segments showed a sensitivity of 52.6% and a specificity of 98.2%.

Conclusion

CTA is highly accurate in the assessment of anatomical variations of the circle of Willis; however, its sensitivity is limited in depicting hypoplastic segments.
Internal jugular thrombosis post venoplasty for chronic cerebrospinal venous insufficiency
Authors:   Imperial College CCSVI Investigation Group, Thapar A , Lane T R A , Pandey V , Shalhoub J , Malik O , Ellis M , Franklin I J , Nicholas R , Davies A H
Published: July 2011

Chronic cerebrospinal venous insufficiency (CCSVI) is a hypothesis through which cerebral venous drainage abnormalities contribute towards the pathogenesis of multiple sclerosis. CCSVI venoplasty is already practised worldwide. We report the case of a 33-year-old lady with multiple sclerosis who underwent left internal jugular venoplasty resulting in iatrogenic jugular thrombosis requiring open thrombectomy for symptom relief. This occurred without insertion of a stent and while fully anticoagulated. Clinicians should be aware that endovenous treatment of CCSVI could cause paradoxical deterioration of cerebral venous drainage. Patients with complications post venoplasty are now presenting to geographically distant vascular units.
Lack of ADAM15 in mice is associated with increased osteoblast function and bone mass
Authors: Marzia Marilena , Guaiquil Victor , Horne William C. , Blobel Carl P. , Baron Roland , Chiusaroli Riccardo
Published: July 2011

The ADAMs (a disintegrin and metalloprotease) contribute to various biological functions including the development of tissues by taking part in cell-cell and cell-matrix interactions. We previously found that ADAM15 is prominently expressed in osteoblasts and to a lesser extent in osteoclasts. The aim of this study was to investigate a possible function of ADAM15 in bone. Adult ADAM15-/- mice displayed an increase in bone volume and thickness with an increase in the number and activity of osteoblasts, whereas osteoclasts were apparently unaffected. We found an increase in proliferation, alkaline phosphatase (ALP) staining and nodule deposition, and mineralization in cultures of ADAM15-/- osteoblasts compared to wild-type osteoblasts. We also observed an increase in β-catenin immunoreactivity in the nucleus of ADAM15-/- osteoblasts compared to wild-type, whereas β-catenin in the membrane/cytoplasm compartment appeared to undergo increased degradation. Furthermore, cyclin D1 and c-Jun, known downstream targets of β-catenin and effectors of cell activation, were found up-regulated in absence of ADAM15. This study indicates that ADAM15 is required for normal skeletal homeostasis and that its absence causes increased nuclear translocation of β-catenin in osteoblasts leading to increased osteoblast proliferation and function, which results in higher trabecular and cortical bone mass.
Utilization of surfactants for consolidation of wooden work of art
Authors: Kubrichtová Daniela , Kučerová Irena
Published: July 2011

The effect of consolidation is proportional to the content of polymer in wood, i.e., to the ability of wood to absorb a polymer solution. One of the ways of increasing the absorption of the polymer solution is its modification by a surfactant. This article evaluates in detail the impact of non-ionic, anionic, and cationic surfactants on penetration of the ethylmethacrylate and methacrylate copolymer solution (Paraloid B72 in toluene) into lime wood by capillary rise. The impact of surfactants is evaluated on the basis of the solution surface tension, the contact angle of a sessile drop, and absorption of the solution by wood. Anionic and non-ionic surfactants based on polyoxyethylene had a positive impact on penetration of Paraloid B72 solution due to their ability to form inverse micelles in toluene. Fluorinated surfactants, polydimethylsiloxane-based surfactants, and cationic surfactants worsen its penetration.
Preparation of chitosan oligomers and characterization: their antifungal activities and decay resistance
Authors: Hussain Ibrar , Singh Tripti , Chittenden Colleen
Published: July 2011

Chitosan, a polymer of D-glucosamine, is known for its antimicrobial activity. However, the physicochemical properties of chitosan depend upon three principal factors, i.e., source of raw material, molecular weight and degree of deacetylation. Here, synthesis and characterization of chitosan oligomers is reported, which were prepared by the nitrous acid deaminative depolymerization of chitosan obtained from Sigma Aldrich and China (industrial grade). Subsequently, their antifungal activities were evaluated against selected basid-iomycetes. The nutrient medium bioassay results show that chitosans and chitosan oligomers affected mycelial growth to different magnitudes. Nevertheless, two of the low-MW chitosan oligomers completely inhibited the growth of all the tested fungi as compared to high-MW chitosan oligomers. Accordingly, antifungal activity increases by decreasing degree of polymerization of chitosan oligomers, which is divergent to literature data. The wood decay trial confirmed the antifungal activity of chitosan oligomers against basid-iomycetes. Chitosan is leachable by water.
Longitudinal Study of Effect of Hotz's Plate and Lip Adhesion on Maxillary Growth in Bilateral Cleft Lip and Palate Patients
Authors: Hak Muhammad Syafrudin , Sasaguri Masaaki , Sulaiman Farida Kamil , Hardono Enny Tyasandarwati , Suzuki Akira , Nakamura Seiji , Ohishi Masamichi
Published: July 2011

Objective

To investigate the effects of infant orthopedic treatment and lip adhesion on maxillary growth of patients with bilateral cleft lip and palate (BCLP).

Design

Prospective longitudinal study.

Setting

The present study was conducted at the Cleft Lip and Palate Center, Harapan Kita Children and Maternity Hospital, Indonesia, and the Department of Oral and Maxillofacial Surgery, Kyushu University Hospital, Japan.

Subjects

The study sample consisted of 53 patients with complete BCLP and 10 noncleft patients with other diseases. Patients with BCLP were divided into three groups: H (-), 11 patients treated without Hotz's plate; H (+), 24 treated with Hotz's plate; and LA-H, 18 treated with lip adhesion and Hotz's plate.

Methods

Serial dental casts were obtained from each BCLP child at the following four time points: first visit, labioplasty, palatoplasty, and 5 years of age. Each maxillary dental cast was scanned, and the linear and angular dimensions were measured.

Results and Conclusion

Lip adhesion showed a temporary negative effect. In all patients with BCLP, the surgeries affected the growth of the anterior arch width until the age of 5 years. Collapse of the premaxilla following labioplasty in the H (-) group affected the growth of dental arch length until the age of 5 years. Treatment using Hotz's plate prevented collapse of the premaxilla, and the growth of the arch length was comparable to that observed in the noncleft group.
Stability and strength analysis of leaning towers
Authors: MARCHI M. , BUTTERFIELD R. , GOTTARDI G. , LANCELLOTTA R.
Published: July 2011

Many ancient towers are afflicted by stability problems. Shallow foundations are typical components of such structures, and their behaviour strongly influences the overall safety of the tower. This paper is concerned with two major, geotechnically related, failure modes of tower foundations: (a) bearing capacity failure, due to lack of strength of the supporting soil; and (b) instability of equilibrium, due to lack of foundation stiffness. Both of these hazards are tackled in a unified way in the paper, using a strain-hardening plasticity model for shallow footings from which a non-linear rotational stiffness (moment–rotation curve) for the soil–foundation system can be derived. The stability of equilibrium analysis is augmented by the inclusion of rotational creep, which is new, and an important feature of the behaviour of real towers. The practical utility of the analysis resides in its simplicity, input parameters being derived from conventional geotechnical data. The analysis provides not only a complete framework within which both failure mechanisms can be assessed but also a prediction of which of them is eventually most likely to be critical. The methodology is demonstrated in relation to the Pisa Tower.
A New Approach to Aquifer Influx Calculation for Finite Aquifer System
Authors: Omeke James E , Nwachukwu A. , Awo R. O , Obah Boniface , Uche I. N
Published: July 2011

Among the classic models used in the evaluation of aquifer properties, the most used are Van Everdingen & Hurst, (1949), Fetkovich approximate (1971), Carter & Tracy (1960), Allard & Chen (1984), and Leung (1986). Due to the inherent uncertainties in the aquifer characteristics, all the models require historical reservoir performance data to evaluate aquifer property parameters. The fact that the reservoir-aquifer boundary pressure is not constant with time gives rise to computational challenges. Most authors seek to eliminate this disadvantage by bringing up approximate models. Fetkovich assumes a constant boundary pressure while deriving his model and required a superposition to get a proper result. This led to the introduction of some forms of pressure approximation and iterations; any error introduced is constituted by this. Higher computational ability is mostly required especially in the evaluation of the Everdingen & Hurst model due to the application of Duhamel superposition principle. More uncertainty however is also seen in the geometry and areal continuity of the aquifer itself.

In this paper, a fast and simple approach was used to develop a new aquifer influx model for a finite aquifer system that admits a pseudo-steady-state flow regime. The partial differential equation that characterizes the flow of aquifer in the reservoir was considered. It was simplified through some basic assumption and in turn resulted to ordinary differential equation, with an appropriate boundary condition, a solution was gotten that enables a direct calculation of cumulative water influx at a given time without the use of superposition or pressure approximations or iterative means. In other to derive a solution under varying reservoir-aquifer boundary pressure the dependency of the boundary pressure with time was described as an exponential trend, which is mostly the case.

In other to validate the developed model, comparison was made with Carter & Tracy, Fetkovich and Van Everdingen Models. Van Everdingen and Hurst Model was used as the standard for comparison since it represents the exact solution of radial diffusivity equation. Two case examples were considered. The results show a close match between the developed model and the existing models, also from the error analysis made, it was noticed that the predictions of the newly developed model were better than that of the Carter & Tracy.
Application of Genetic Algorithm in Deconvolution of Logs
Authors: Mogbolu Peter O. , Akinola Olayinka , Uguru Chukwuma
Published: July 2011

The wave pattern observed during data acquisition from the subsurface rock is often affected by heterogeneity, formation fluid, tool resolution and other forms of noise. Often however, the aim of the engineer or geologist is to generate the original pattern by deconvolving the wave such as in seismic interpretation. Subsequently, several models have been designed over the years but most of them require the use of cumbrous logical sequences which are difficult to understand and are thus written in computer programs.

This paper aims to solve the problem by the use of a method that involves the backward modelling of such wave patterns using genetic algorithm. This works on the principle of evolution of data such that different individuals converge to a perfect individual, imitating natural evolution. Using this method, a model was created to deconvolve waves. The assumption made was that some waves (including logs) originate from two extreme divergent points before the influence of ‘noise’. The new model was used to recreate the wave pattern and was compared to the input wave.

The model was tested on pseudo-logs wave patterns and the results were estimate to be between 80% and 95% accurate. The significance however, is that such model can be used to recreate lithological patterns which can be used to project forward models by applying certain rock properties.
Best Use of Production Tests – Estimating Well Productivity Parameters in the Absence of Bottomhole Pressure Tests
Authors: Samson Ibukun , Onyekonwu Mike
Published: July 2011

Most operators routinely (usually monthly) carry out production tests on flowing wells as against the bottomhole pressure (BHP) surveys which are not frequently done. This is often the case in wells where economic considerations do not support the costs of acquiring such data. The semi-annual acquisition of BHP data as required by the Department of Petroleum Resources (DPR) is very seldom implemented. This is more so in wells located in marginal fields or wells belonging to smaller operators. In cases where the data is actually acquired, interpretation of the acquired data is frequently not done.

The lack of BHP data has made it difficult for many E&P professionals to estimate well productivity parameters such as productivity index (J), skin (S) and flow efficiency (FE). These parameters are required to predict the performance of production wells and estimate the reserves for such wells. The estimated reserves in turns affect the evaluation of economic viability of such assets.

This paper enumerates practical procedures for estimating and monitoring well productivity parameters from analysis of routine production test data. It also provides procedures for quality checking (therefore accepting or rejecting) results of well productivity parameters obtained from interpretation of BHP tests. The paper goes on to introduce trend analysis as a means of estimating well productivity parameters. A discussion on the conditions under which trends can be extrapolated is also provided. A sample data set is included in the paper as an example to demonstrate some of the proposed procedures and to clarify ambiguities.
Case study: Numerical Simulation on Formation Damage in Low-permeability Gas Reservoir
Authors: Xu Feng , Guo Xiao , Zhang Yong , Wang Mianmian , Zhang Nan , Li Jiudi
Published: July 2011

The study on the formation damage mechanism in low-permeability gas reservoirs is conductive to establish reasonable and effective development policies. The effects that the threshold pressure gradient and stress sensitivity have on productivity during the development. Rock samples of PH group have gone through with threshold pressure gradient measurement and stress sensitivity test. The results show that the average threshold pressure gradient is 0.00011MPa/cm, and stress sensitivity index is 0.04 on average, belonging to low stress sensitivity. In this paper a special method of dealing with seepage law in low permeability gas reservoir is mentioned, including how to process the threshold pressure gradient and converse the experimental data to field application. The formation damages caused by threshold pressure gradient and stress sensitivity are respectively simulated in the numerical simulation software to evaluate their effects on the gas reservoir development. The results of the simulation show that: 1) when the impact of threshold pressure gradient is considered, the stable production period of the gas well is 150 days shorter than that when the impact of threshold pressure gradient is ignored, and the final recovery of stable production is 7.35% lower; 2) when the impact of stress sensitivity is considered, the stable production period of the gas well is 510 days shorter than that when the impact of stress sensitivity is ignored, and the final recovery of stable production is 12.52% lower.
Efficient Methodology for Stimulation Candidate Selection and Well Workover Optimization
Authors: Ugbenyen Benson Oghenovo , Ogbe David O. , Osisanya Samuel O.
Published: July 2011

Nigeria is endowed with huge proven gas reserves estimated to be 184 trillion cubic feet (Tcf). It ranks as the seventh holder of natural gas reserves in the world, and the largest in Africa. Nigeria also flares more natural gas than any other country; it accounts for 12.5% of the world's annual gas flared equivalent to $2.0 billion of annual revenue wasted. There is crucial need, therefore, to reduce gas flaring and its environmental impacts, and to derive maximum economic benefits from gas production.

Well stimulation consists of several methods used for enhancing the natural producing ability of the reservoir when production rate declines. The purpose of the study is to present a methodology and models for the selection, design and optimization of well stimulation. Production decline curve analysis is combined with economic discounting concepts to develop a model that can be used for optimizing stimulation decisions. The model is presented in the form of a non-linear programming problem subject to the constraints imposed by the production facilities, reservoir productivity and the stimulation budget approved by management. Production data from four stimulation candidate wells, offshore Niger Delta was used to validate the model developed by setting up a maximization problem. Solution to the problem was obtained using non-linear optimization software. The results show that the optimization model can be combined with stimulation treatment modules, developed from industry wide models, to quantify stimulation benefits. Candidate wells were then ranked based on stimulation cost, payout time and stimulation benefit. Proposed methodology and models can be used for stimulation candidate selection, ranking workover programs in a field and in optimizing stimulation decisions.
Modeling Petrophysical Properties Input for Probabilistic Reserves Estimation
Authors: Ehigie S. O.
Published: July 2011

While the popularity of the numerical simulation approach (such as the Monte Carlo) for probabilistic reserves estimation has never been higher among geoscientists and reservoir engineers, comparatively little attention has been paid to the techniques needed to correctly model the required petrophysical input parameters.

Petrophysical well analyses typically end in the presentation of average reservoir property values for porosity, water saturation and net-to-gross but these lone averages, while adequate for deterministic reserves estimates, obviously fail to account for the inherent reservoir petrophysical properties uncertainty within a probabilistic reserves estimate. Of more importance for probabilistic reserves estimation is a statistical model comprising Probability Distribution Functions (or PDFs) of the aerial uncertainty in reservoir properties resulting from a larger reservoir being sampled by a relatively small discrete well population.

Monte Carlo simulations are typically used to estimate probabilistic reserves but the accuracy of these are strongly correlated to the quality of the input probability distributions. Many errors in the outputs of reserves models could be traced back to assigning incorrect values to the descriptive parameters of a distribution, and indeed the selection of an appropriate distribution. Therefore, if probability distributions are to be used to represent statistical assumptions of petrophysical properties in reserves estimates, then the way petrophysical averages data is analysed and transformed into PDFs becomes of crucial importance.

Hence, the purpose of this paper is to present practical ideas for achieving the definition of probability distributions that best represent the petrophysical property input into probabilistic reserves estimates.

The focus on petrophysical properties in this paper is not arbitrary or accidental but, instead, reflects the centrality of petrophysical input as a driver of accuracy in reserves estimates.
Optimization of Strategies for Natural Gas Utilization: Niger Delta Case Study
Authors: Ogbe Emmanuel , Ogbe David O. , Iledare Omowumi
Published: July 2011

Nigeria is endowed with huge proven gas reserves estimated to be 184 trillion cubic feet (Tcf). It ranks as the seventh holder of natural gas reserves in the world, and the largest in Africa. Nigeria also flares more natural gas than any other country; it accounts for 12.5% of the world's annual gas flared equivalent to $2.0 billion of annual revenue wasted. There is crucial need, therefore, to reduce gas flaring and its environmental impacts, and to derive maximum economic benefits from gas production.

The purpose of this paper is to identify options for natural gas utilization and to develop a model for optimizing the natural gas utilization strategies using the Niger Delta as a case study. A Linear Programming model is proposed consisting of an objective function that is based on maximizing profit derived from the various utilization projects in the Niger Delta subject to several constraints. The optimal utilization/decision is determined from the solution of the optimization model. Results obtained indicate that the optimal utilization for maximum profit include both current and planned projects such as the Liquefied Natural gas project at Bonny, supply of gas for domestic use and power generation, transport to West African countries, transport of natural gas to Algeria through the TransSaharan Gas Pipeline (TSGP), and sales of EOR products to market. Upcoming project such as the Olokola LNG was only profitable as the gas price increases. Sensitivity analysis is carried out to evaluate impact of changes in the input parameters on the objective function. Paper also discusses the impact of gas pricing on the implementation of the Nigerian gas master plan (NGMP).

The model can be used to select which set of projects would provide maximum profits (net income) from several competing natural gas projects.