bluuebunny/crossref_metadata_2025 huggingface dataset:
Mathematical Modeling of Plant Metabolism―From Reconstruction to Prediction
Authors: Nägele Thomas , Weckwerth Wolfram
Published: September 2012

Due to their sessile lifestyle, plants are exposed to a large set of environmental cues. In order to cope with changes in environmental conditions a multitude of complex strategies to regulate metabolism has evolved. The complexity is mainly attributed to interlaced regulatory circuits between genes, proteins and metabolites and a high degree of cellular compartmentalization. The genetic model plant Arabidopsis thaliana was intensely studied to characterize adaptive traits to a changing environment. The availability of genetically distinct natural populations has made it an attractive system to study plant-environment interactions. The impact on metabolism caused by changing environmental conditions can be estimated by mathematical approaches and deepens the understanding of complex biological systems. In combination with experimental high-throughput technologies this provides a promising platform to develop in silico models which are not only able to reproduce but also to predict metabolic phenotypes and to allow for the interpretation of plant physiological mechanisms leading to successful adaptation to a changing environment. Here, we provide an overview of mathematical approaches to analyze plant metabolism, with experimental procedures being used to validate their output, and we discuss them in the context of establishing a comprehensive understanding of plant-environment interactions.
Design, Practical Synthesis, and Biological Evaluation of Novel 6-(Pyrazolylmethyl)-4-quinoline-3-carboxylic Acid Derivatives as HIV-1 Integrase Inhibitors
Authors: Hu Liming , Yan Song , Luo Zaigang , Han Xiao , Wang Yujie , Wang Zhanyang , Zeng Chengchu
Published: September 2012

A series of novel 6-(pyrazolylmethyl)-4-oxo-4H-quinoline-3-carboxylic acid derivatives bearing different substituents on the N-position of quinoline ring were designed and synthesized as potential HIV-1 integrase (IN) inhibitors, based on the structurally related GS-9137 scaffold. The structures of all new compounds were confirmed by 1H-NMR, 13C-NMR and ESI (or HRMS) spectra. Detailed synthetic protocols and the anti-IN activity studies are also presented.
Activity-Guided Isolation of Antioxidant Compounds from Rhizophora apiculata
Authors: Gao Mingzhe , Xiao Hongbin
Published: September 2012

Rhizophora apiculata (R. apiculata) contains an abundance of biologically active compounds due its special salt-tolerant living surroundings. In this study, the total phenolic content and antioxidant activities of various extract and fractions of stem of R. apiculata were investigated. Results indicated that butanol fraction possesses the highest total phenolic content (181.84 mg/g GAE/g dry extract) with strongest antioxidant abilities. Following in vitro antioxidant activity-guided phytochemical separation procedures, lyoniresinol-3α-O-β-arabinopyranoside (1), lyoniresinol-3α-O-β-rhamnoside (2), and afzelechin-3-O-L-rhamno-pyranoside (3) were separated from the butanol fraction. These compounds showed more noticeable antioxidant activity than a BHT standard in the DPPH, ABTS and hydroxyl radical scavenging assays. HPLC analysis results showed that among different plant parts, the highest content of 1–3 was located in the bark (0.068%, 0.066% and 0.011%, respectively). The results imply that the R. apiculata might be a potential source of natural antioxidants and 1–3 are antioxidant ingredients in R. apiculata.
Regiocontrolled Microwave Assisted Bifunctionalization of 7,8-Dihalogenated Imidazo[1,2-a]pyridines: A One Pot Double-Coupling Approach
Authors: Marie Emilie , Bouclé Sébastien , Enguehard-Gueiffier Cécile , Gueiffier Alain
Published: September 2012

The reactivity of the 7-chloro-8-iodo- and 8-chloro-7-iodoimidazo[1,2-a]pyridines 1a–e diversely substituted on the 2 position, towards Suzuki-Miyaura, Sonogashira, and Buchwald-Hartwig cross-coupling reactions as well as cyanation was evaluated. Various methodologies are proposed to introduce aryl, heteroaryl, alkyne, amine or cyano groups in the two positions depending on the nature of the substituent present in position 2. In both series, the substitution of the iodine atom was totally regioselective and the difficulty was to substitute the chlorine atom in a second step. Until now, only hetero(aryl) groups could be introduced though Suzuki-Miyaura cross-coupling. We overcame this problem evaluating both regioisomers in parallel. The double coupling approach was also studied allowing the one pot Suzuki/Suzuki, cyanation/Sonogashira and cyanation/Buchwald reactions leading to polyfunctionnalized imidazo[1,2-a]pyridines.
Itx 5061 Quantitation in Human Plasma with Reverse Phase Liquid Chromatography and Mass Spectrometry Detection
Authors: Hochreiter Jill , Lapham Jill , Wong-Staal Flossie , McKelvy Jeffrey , Sulkowski Mark , Glesby Marshall J , Johnson Victoria A , Morse Gene D
Published: September 2012

Background

ITX 5061 is a highly potent small molecule inhibitor of scavenger receptor-B1, an integral transmembrane protein that is found in liver cells and is actively involved in the transport of HCV into hepatocytes. Currently, ITX 5061 is being investigated in monoinfected hepatitis C patients in a proof-of-concept clinical trial carried out by the AIDS Clinical Trial Group (ACTG).

Methods

To provide quantitative results in human plasma for pharmacokinetic analysis, an assay for ITX 5061 was validated. ITX 5061 and the internal standard, a deuterated analogue, were separated by isocratic reverse phase chromatography using a Polar RP column (Phenomenex Synergi™; 2.0 mmx50 mm, 4 μm) and detected via electrospray coupled to a triple quadrupole mass spectrometer with a run time of 5 min. Multiple reaction monitoring in positive mode was used with ITX 5061 at 585/114 m/z and the internal standard at 592/122 m/z with a linear range of 2.50–5,000 ng/ml. Human plasma was extracted using a protein precipitation combing 400 μl of acetonitrile with 100 μl of EDTA plasma.

Results

The interassay variation ranged from 1.19 to 13.2%, while the intraassay variation ranged from 0.394 to 12.9% over 6 days of testing. The method was successfully applied to the samples collected for the ACTG Protocol A5277. Plasma concentrations at 1 h and 24 h following 150 mg ITX 5061 daily in HCV monoinfected patients ( n=3) ranged from 138 to 518 ng/ml and 33 to 111 ng/ml, respectively.

Conclusions

The ITX 5061 assay is accurate and reproducible with a wide linear range and will be used for pharmacokinetic analysis and dose-finding studies in HCV-monoinfected patients.
Open Release and a Hinged External Fixator for the Treatment of Elbow Stiffness in Young Patients
Authors: Ouyang Yuanming , Wang Yongping , Li Fengfeng , Fan Cunyi
Published: September 2012

Elbow stiffness is a well-recognized complication following elbow trauma, but little information is available regarding the surgical treatment of elbow stiffness in children and adolescents. This article presents the results of open arthrolysis with twin incisions and a hinged external fixator to treat severe elbow contracture in children and adolescents.

Twenty-one patients (mean age, 14.9 years; range, 7–19 years) were evaluated. All patients underwent surgery using a hinged external fixator and a combined mediolateral approach to address the elbow contracture. Mayo elbow score and range of motion (ROM) were measured preoperatively and at 3, 12, and 24 months postoperatively. All but 1 patient achieved a functional ROM of 100°. Preoperatively, mean flexion was 70.2° (range, 30°–100°), extension was 42.6° (range, 0°–80°), and total ROM was 28.5° (range, 0° to 80°); postoperatively, mean flexion improved to 122.8° (range, 90°–140°), extension to 10° (range, 0°–30°), and total ROM to 114.5° (range, 60°–140°). The Mayo elbow score improved from a mean of 48 points (range, 35–65 points) to 90 points (range, 75–100 points), and 9 patients had excellent results, 7 had good results, 4 had fair results, and 1 had a poor result. No significant differences existed between postoperative measurements at 3, 12, and 24 months. No pin-tract infections or deep infections occurred, and no vascular or neurological complications were noted.

Surgical treatment of elbow stiffness using a hinged external fixator and open arthrolysis is an effective procedure in children and adolescents.
Surgical Management of Congenital Cervical Kyphosis
Authors: He Zhimin , Liu Yang , Xue Feng , Xiao Haijun , Yuan Wen , Chen Deyu
Published: September 2012

Congenital cervical kyphosis is a rare clinical condition. The purpose of this study was to review the surgical management and outcomes of 12 consecutive cases of congenital cervical kyphosis management by the same surgical team. The authors retrospectively analyzed the records of 12 patients (5 men and 7 women) with an average age of 18.4 years (range, 15–31 years) who underwent surgery for congenital cervical kyphosis at the authors’ institution between 2001 and 2005. All patients had congenital cervical kyphosis; those with secondary kyphosis deformity due to causes such as infection, tumors, and surgery were excluded. The indications for surgery were signs of spinal cord compression with progression of clinical symptoms such as decreased muscle strength and paresthesia. All patients had radiographic evidence of cervical kyphosis. Six patients underwent anterior decompression, autogenous bone grafting, and instrumentation, and the other 6 patients underwent combined anterior–posterior surgery. All surgeries were performed successfully with no complications. Bone graft fusion occurred in 11 patients. In 1 patient who underwent anterior surgery, the bone graft was partly absorbed, and pseudarthrosis was noted at 3 years postoperatively. Mean Japan Orthopaedic Association cervical myelopathy score and mean Cobb angle were significantly improved at 1 week and 1 year postoperatively compared with preoperative values.

Anterior and combined anterior–posterior surgical approaches are useful for the correction of congenital cervical kyphosis. Bone graft fusion is also critical for maintaining the surgical correction. Choice of surgical methods depends on the patient’s clinical condition.
Prevalence of Answers to Orthopaedic In-Training Examination Questions in 3 Commonly Used Orthopedic Review Sources
Authors: Krueger Chad A. , Shakir Irshad , Fuller Brian C.
Published: September 2012

One of the greatest predictors for resident success on the Orthopaedic In-Training Examination (OITE) is reviewing previous OITE questions. However, no studies have examined which review sources contain the most answers to previously asked OITE questions. The goal of this study was to determine which review source contains the most answers to previously asked OITE questions.

Each question from the 2006 to 2010 OITEs was examined. The questions were placed into 1 of 13 categories based on their topic. The publication date of the recommended readings associated with each question was recorded. The answer to each question was then searched for in 3 commonly used review sources: Miller’s
Review of Orthopaedics
, 5th edition (MRO), American Academy of Orthopaedic Surgeons
Comprehensive Orthopaedic Review
(COR), and
www.orthobullets.com
(OB). Searchable electronic versions of each textbook were used, and each question had a 12-minute time limit. Of 1358 questions, 665 (49%) were found in all 3 sources. Significantly more answers were found on OB (99.4%) compared with MRO (60%) and COR (62%) (
P
<.0001). Significantly more answers to questions in each question category were found on OB compared with MRO or COR (
P
<.0001). More than 50% of all recommended readings for OITE questions were published within 5 years of the OITE.

Residents using OB to review for the OITE will be exposed to significantly more answers of previously asked OITE questions than residents using MRO or COR (
P
<.0001).
Total Volar Extrusion of the Lunate and Scaphoid Proximal Pole With Concurrent Scapholunate Dissociation
Authors: Koh Kyoung Hwan , Lim Tae Kang , Park Min Jong
Published: September 2012

This article describes a case of a 24-year-old man with a total volar extrusion of the lunate and scaphoid proximal pole with concurrent scapholunate dissociation. The viability of the lunate and the proximal pole of the scaphoid are at high risk in this type of injury. Scaphoid nonunion, avascular necrosis of the lunate and proximal pole of the scaphoid, and carpal instability are inevitable unless the blood supply is restored. Thus, proximal row carpectomy at injury may be an acceptable option to avoid these complications and late sequelae, including chronic wrist pain and dysfunction. However, the authors attempted accurate reduction of the extruded bones and internal fixation.Final radiographs and magnetic resonance imaging 12 years postoperatively showed healing without avascular necrosis. Carpal indices involving the scapholunate angle, radiolunate angle, and carpal height ratio were similar in both wrists without evidence of carpal instability or collapse. Range of motion and grip power were 75% and 76%, respectively, compared with those of the uninjured wrist. Clinical scores showed good results, and the patient reported no pain during activities of daily living and was satisfied with his surgical results. Open reduction and internal fixation can be a viable option in this rare pattern of injury.
Athletic Cervical Spine Injury in the Setting of Fusion Failure of the Anterior and Posterior Atlas
Authors: Petre Benjamin M. , Karp Jacqueline E. , Riley Lee H.
Published: September 2012

This article describes a rare congenital abnormality of anterior and posterior C1 fusion failure presenting after an acute athletic injury to the fibrous nonunion. C1 congenital malformations are rare, occurring in approximately 2% of patients; even rarer are combined anterior and posterior arch malformations in the same patient. Posterior ring abnormalities are more common than anterior ring injuries (4.5:1, respectively). To the authors’ knowledge, combined anterior and posterior ring congenital malformations with subsequent injury have not been previously described.

In the current patient, a congenital failure of fusion of the anterior and posterior arches of C1 was identified. The anterior fibrous nonunion was injured while the patient played football, leading to transient neurologic injury and dysphagia from soft tissue swelling. The patient was initially diagnosed with an acute fracture at another facility; however, given advanced imaging, flexion and extension views, and a normal neurologic examination, the authors diagnosed a traumatized congenital defect. The injury healed with a short period of cervical collar immobilization and supportive measures. Such malformations are usually found incidentally, but they can be symptomatic after trauma. Images to distinguish these deficits can be difficult because the differences between chronic nonunions and congenital malformations are subtle. Surgery is rarely indicated for congenital malformations because they are often stable even after injury; however, they may predispose patients to neurologic injury in the future with high-risk activities. Because the current patient had an increased chance of future injury secondary to the lack of bone formation in the C1 vertebrae, he was restricted from participating in contact sports.
mLearning
Authors: Denham Andre R. , Quick John M. , Atkinson Robert K.
Published: September 2012

Rapid advances in mobile hardware and software have fueled the emergence of mobile learning (mLearning) as an area of interest within educational research. In spite of abundant excitement and discussion surrounding mLearning, certain challenges remain unresolved. To date, it seems the field is most enamored with categorizing hardware capabilities and replicating conventional learning content on portable devices. However, it would be beneficial to consider how mLearning can augment learners’ education in unique ways. Prior definitions of mLearning fall short in articulating why mobility is beneficial for learning and how mobile learning is not simply a reformulation of existing eLearning methods. A new perspective is offered to establish mLearning as a unique type of learning. Evidence from the field of embodied cognition that points to the potential affordances of mLearning is provided and future directions are discussed.
Driven by a Social and Interactional Routine
Authors: Rauniomaa Mirka , Haddington Pentti
Published: September 2012

The article reports findings from a qualitative study that draws on the methods of conversation analysis and on audio-video recordings of ordinary, real-life, non-experimental driving situations. The article shows what happens in a car after a mobile phone summons, i.e., the initial ring or beep of a car occupant’s phone. It identifies three phases (i.e., orienting to, locating and handling a phone) that follow the summons and lead to an attempt at verbally responding to the summons. It is shown that the ringing of a phone (indicating an incoming call) or the beeping of a phone (indicating an incoming text message), as a socially and interactionally significant action, is treated as requiring a more or less immediate response. It is argued that this routinization of responding to a summons explains drivers’, and possible passengers,’ use of a mobile phone while traveling in a car.
Investigating Web 2.0 Application Impacts on Knowledge Workers’ Decisions and Performance
Authors: Ajjan Haya , Hartshorne Richard , Buechler Scott
Published: September 2012

Web 2.0 applications (such as blogs, wikis, and group messaging) have been widely adopted by organizations to enhance the effectiveness of internal communication and improve knowledge management within the organization. However, predictors that impact Web 2.0 continuous use within the organization and knowledge management performance have been neither well defined nor well understood in academia and practice. This paper empirically investigates the impact of hedonic and utilitarian performance on continual usage intention of Web 2.0 applications within the organization, and then examines continuance use decision impact on knowledge management performance. The authors’ results are useful in developing guidelines and strategies to increase the likelihood of Web 2.0 continuance use and to improve its positive impact within the organization.
Exploring the Complexities of Community Engaged GIS
Authors: Mukherjee Falguni , Ghose Rina
Published: September 2012

Participatory GIS projects are increasingly popular in urban governance. This paper explores the complexities of a community involved pilot project that was implemented in the town of Verona, Wisconsin and critically examines their GIS (Geographic Information Systems) practices and the support structures that played an important role in facilitating GIS use. The paper first traces the evolution of the project, and the role of the various actors in shaping it and then shows that relations between key institutions and actors played a crucial role in shaping the pilot project. While inherently supportive, these actors occupied a dominant power position, setting a top down tone to the project from its onset. As such, the project simultaneously enhanced and constricted the process of participation and spatial knowledge production of the community residents.
Estimating Residential Carbon Footprints for an American City
Authors: Connolly Matthew H. , Hagelman Ronald R. , Fuhrmann Sven
Published: September 2012

The proliferation of online emission calculators and the growing popularity of carbon footprint assessments recently underscores an emerging interest among Americans in understanding their personal environmental impacts, especially in relation to greenhouse gas emissions. While studies have quantified carbon footprints at a variety of geographic scales using economic data, or a combination of economic and census data, few have produced results that were immediately useful for local-scale emission reduction efforts. The authors explore the feasibility of utilizing block group level census data to estimate the residential carbon footprint of an American city. A census-based emission model was adapted from the United States Environmental Protection Agency’s Individual Emission Calculator. Block group census data were used as surrogates for household energy consumption and transportation related carbon emissions. Although lacking some of the finer nuances of individual behavior assessments, this approach enables analysis of a continuous urban landscape with a relatively high degree of data resolution using Geographic Information Systems (GIS) and standard desktop-software. The model output, paired with choropleth and dasymetric visualizations, illustrate that census data can be successfully adapted to estimate the residential carbon footprint for Austin, Texas, and by extension, any other American city with equivalent census data coverage.
The Challenges of Carbon Capture and Storage (CCS) Development in China
Authors: Zhao Ang
Published: September 2012

As a significant mitigation strategy to fight climate change, Carbon Capture & Storage (CCS) demonstration projects have received huge amount of public funding across the world. After examining three large scale integrated CCS coal-fired power demonstration projects, which are carried out by America, Europe and China, this paper presents three different approaches that three authorities are taking to support the adventure of CCS technology. By comparing these three cases, the paper demonstrates there exist some significant challenges in CCS development in China and offer relevant policy recommendations to cope with the challenges.
The Amount of Control in Offshore Software Development Projects
Authors: Remus Ulrich , Wiener Martin
Published: September 2012

Prior research has focused on factors influencing the choice of controls in traditional project settings. Building on this research, this paper investigates the amount of control—defined as the variety and intensity of control mechanisms—in offshore software development projects. Using a comparative case study approach, the authors put forward eight propositions regarding the factors that influence the amount of control and its dynamics. Their results not only confirm existing findings, such as the predominance of formal controls and the negative effect of trust on the amount of formal control, but also contribute with new findings. For instance, they were able to identify particularly high levels of control in projects with high task complexity and/or high offshore team involvement as well as intensive use of formal (outcome) control in high volume and strategically important projects. The authors’ empirical findings are integrated in a conceptual model that leads to a better understanding of the antecedents of the amount of both formal and informal controls. In contrast with previous studies, their findings do not support the notion that the amount of control is directly related to project success.
End User Adoption of Enterprise Systems in Eastern and Western Cultures
Authors: Hwang Yujong
Published: September 2012

Enterprise systems are gaining interest from both international practitioners and researchers, and this paper investigates enterprise systems management and implementation issues comparing Eastern and Western end users. This issue is important because currently enterprise systems involve end-users with different cultural backgrounds in the East and West. Thus, this paper applies enterprise systems adoption issues to cross-cultural end user perspectives in Japan (East) and the U.S. (West), based on the innovation diffusion theory, the self-determinant theory, and Hofstede’s cultural dimensions. Academic and practical implications are discussed in the paper based on empirical findings found deeper in this paper.
Computer Self-Efficacy
Authors: Karsten Rex , Mitra Atul , Schmidt Dennis
Published: September 2012

Computer self-efficacy (CSE) has been a popular and important construct in information systems research for more than two decades. Although CSE researchers have conducted extensive qualitative reviews, quantitative analyses are lacking for studies of the relationships between CSE and variables of interest. This study provides such a quantitative analysis. The authors meta-analyze 102 empirical CSE studies that reported 232 usable statistical relationships between CSE and seven correlates. Their main meta-analysis demonstrates that CSE is significantly correlated in the theoretically predicted direction with each of the seven correlates. They also quantitatively assess five study characteristics as potential moderators of the CSE-correlate relationships. The moderator analysis reveals complex patterns and indicates that more research is needed to investigate possible moderating effects.
Semantics for the Internet of Things
Authors: Barnaghi Payam , Wang Wei , Henson Cory , Taylor Kerry
Published: September 2012

The Internet of Things (IoT) has recently received considerable interest from both academia and industry that are working on technologies to develop the future Internet. It is a joint and complex discipline that requires synergetic efforts from several communities such as telecommunication industry, device manufacturers, semantic Web, and informatics and engineering. Much of the IoT initiative is supported by the capabilities of manufacturing low-cost and energy-efficient hardware for devices with communication capacities, the maturity of wireless sensor network technologies, and the interests in integrating the physical and cyber worlds. However, the heterogeneity of the “Things” makes interoperability among them a challenging problem, which prevents generic solutions from being adopted on a global scale. Furthermore, the volume, velocity and volatility of the IoT data impose significant challenges to existing information systems. Semantic technologies based on machine-interpretable representation formalism have shown promise for describing objects, sharing and integrating information, and inferring new knowledge together with other intelligent processing techniques. However, the dynamic and resource-constrained nature of the IoT requires special design considerations to be taken into account to effectively apply the semantic technologies on the real world data. In this article the authors review some of the recent developments on applying the semantic technologies to IoT.
B-Cell Acute Lymphoblastic Leukemia with t(4;11)(q21;q23) in a Young Woman: Evolution into Mixed Phenotype Acute Leukemia with Additional Chromosomal Aberrations in the Course of Therapy
Authors: Carulli Giovanni , Marini Alessandra , Ferreri Maria I. , Azzarà Antonio , Ottaviano Virginia , Lari Tiziana , Rocco Melania , Giuntini Stefano , Petrini Mario
Published: September 2012

About 5% of adult B-cell acute lymphoblastic leukemias (B-ALL) are characterized by t(4;11)(q21;q23), which confers peculiar features to this B-ALL subtype, including a very immature immunophenotype and poor prognosis. We describe the case of a 21-year-old female who presented with B-ALL carrying the t(4;11)(q21;q23) and blasts positive for CD19, TdT, CD79a, CD38, HLA-DR. Before completing the Hyper-CVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone) therapy regimen, the B-cell leukemic clone still was detected, but an additional leukemic clone appeared, with morphology and immunophenotype (CD13, CD33, CD64, CD38, CD56, CD15, CD4dim) compatible with derivation from the myeloid/monocytic lineage. Karyotype showed the co-existence of three cell lines, with persistence of t(4;11)(q21;q23) and appearance of +8,+12,+13 and two der(4). The patient died because of disseminated intravas- cular coagulation. Our report describes a rare, possible evolution of such a subtype of B-ALL, with transformation into mixed phenotype acute leukemia in the course of therapy. This finding suggests a blast cell derivation from a common lymphoid/monocytic precursor leading to a final bilineal acute leukemia.
The role of psychological ownership in retaining talent: A systematic literature review
Authors: Olckers Chantal , Du Plessis Yvonne
Published: September 2012

Orientation: Managing psychological ownership can have positive attitudinal and behavioural effects, promote organisational effectiveness and support talent retention.Research purpose: This paper seeks to explore and describe psychological ownership, distinguish it from other work-related attitudes and clarify the role that psychological ownership can play in retaining talent.Motivation for the study: Previous studies of human resource practices and organisational characteristics that affect organisational commitment and the retention of talent have reported that absent variables could be responsible for varied results. Psychological ownership could be one of them.Research design, approach and method: Based on a systematic review of the literature published over the last 20 years, the authors synthesised various research perspectives into a framework of psychological ownership and its links to retaining talent.Main findings: The authors found that psychological ownership was a comprehensive multidimensional construct. It is distinct from other work-related attitudes and seems capable of enabling organisations to retain the talents of skilled employees.Practical/managerial implications: Organisations can benefit from psychological ownership because it leads employees to feel responsible towards targets (like organisations) and to show stewardship. It can help organisations to retain talent and influence the intentions of skilled employees to remain with their organisations.Contribution/value-add: Psychological ownership, as an integrated multidimensional construct, has expanded the existing theory about the organisational commitment and work-related attitudes that organisations need to retain talent in the 21st century.
Congenital Dacryocystocele: A Rare and Benign Nasolacrimal Duct Cyst Condition
Authors: Bonilla-Musoles Fernando , Castillo Juan Carlos , Jimenez Luis Carlos
Published: September 2012

Dacryocystocele is an uncommon congenital obliteration of the nasolacrimal drainage system. Based on a case diagnosed at 30 weeks gestation using two-dimensional (2D) and threedimensional (3D), its ultrasound characteristics as well as the evolution and therapeutic options applied in the scarce existing literature are described.

How to cite this article

Bonilla-Musoles F, Jimenez LC, Castillo JC. Congenital Dacryocystocele: A Rare and Benign Nasolacrimal Duct Cyst Condition. Donald School J Ultrasound Obstet Gynecol 2012;6(3):233-236.
A Prospective Study of Total Laryngectomy and associated Complications
Authors: Reddy Sudarshan L , Reddy Sridhar D , Prasad AVVSL
Published: September 2012

A prospective study conducted over a period of 2 years at a tertiary care hospital on all patients who underwent total laryngectomy to study the complications of the surgeries, their possible etiology. Laryngectomy is one of the most frequently done oncological surgeries in this part of the world, with high incidence of morbidity. Through improved techniques and preand postoperative protocols the incidence of complications have reduced, none the less they occur. Aim of the present study is to note the incidence of complications and their management in our setup.

How to cite this article

Reddy SL, Reddy SD, Prasad AVVSL. A Prospective Study of Total Laryngectomy and associated Complications. Int J Phonosurg Laryngol 2012;2(1):20-22.
Quantification of uncertainties of water vapour column retrievals using future instruments
Authors: Diedrich H. , Preusker R. , Lindstrot R. , Fischer J.
Published: September 2012

Abstract. This study presents a quantification of uncertainties of water vapour retrievals based on near infrared measurements of upcoming instruments. The concepts of three scheduled spectrometer were taken into account: OLCI (Ocean and Land Color Instrument) on Sentinel-3, METimage on MetOp (Meteorological Operational Satellite) and FCI (Flexible Combined Imager) on MTG (Meteosat Third Generation). Optimal estimation theory was used to estimate the error of an hypothetical total water vapour column retrieval for 27 different atmospheric cases. The errors range from 100% in very dry cases to 2% in humid cases with a very high surface albedo. Generally the absolute uncertainties increase with higher water vapour column content due to H2O-saturation and decrease with a brighter surface albedo. Uncertainties increase with higher aerosol optical thickness, apart from very dark cases. Overall the METimage channel setting enables the most accurate retrievals. The retrieval using the MTG-FCI buildup has the highest uncertainties apart from very bright cases. A retrieval using two absorption channels increases the accuracy, in some cases by one order of magnitude, in comparison to a retrieval using just one absorption channel. On the other hand, a retrieval using three absorption channels has no significant advantage over a two-absorption channel retrieval. Furthermore, the optimal position of the absorption channels was determined using the concept of the "information content". For a single channel retrieval a channel at 900 or 915 nm has the highest mean information contents over all cases. The second absorption channel is ideally weakly correlated with the first one, thus positioned at 935 nm, in a region with stronger water vapour absorption.
Modeling the impact of soil aggregate size on selenium immobilization
Authors: Kausch M. F. , Pallud C. E.
Published: September 2012

Abstract. Soil aggregates are mm- to cm-sized microporous structures separated by macropores. Whereas fast advective transport prevails in macropores, advection is inhibited by the low permeability of intra-aggregate micropores. This can lead to mass transfer limitations and the formation of aggregate-scale concentration gradients affecting the distribution and transport of redox sensitive elements. Selenium (Se) mobilized through irrigation of seleniferous soils has emerged as a major aquatic contaminant. In the absence of oxygen, the bioavailable oxyanions selenate, Se(VI), and selenite, Se(IV), can be microbially reduced to solid, elemental Se, Se(0), and anoxic microzones within soil aggregates are thought to promote this process in otherwise well aerated soils. To evaluate the impact of soil aggregate size on selenium retention, we developed a dynamic 2-D reactive transport model of selenium cycling in a single idealized aggregate surrounded by a macropore. The model was developed based on flow-through-reactor experiments involving artificial soil aggregates (diameter: 2.5 cm) made of sand and containing Enterobacter cloacae SLD1a-1 that reduces Se(VI) via Se(IV) to Se(0). Aggregates were surrounded by a constant flow providing Se(VI) and pyruvate under oxic or anoxic conditions. In the model, reactions were implemented with double-Monod rate equations coupled to the transport of pyruvate, O2, and Se-species. The spatial and temporal dynamics of the model were validated with data from experiments and predictive simulations were performed covering aggregate sizes between 1 and 2.5 cm diameter. Simulations predict that selenium retention scales with aggregate size. Depending on O2, Se(VI), and pyruvate concentrations, selenium retention was 4–23 times higher in 2.5-cm-aggregates compared to 1-cm-aggregates. Under oxic conditions, aggregate size and pyruvate-concentrations were found to have a positive synergistic effect on selenium retention. Promoting soil aggregation on seleniferous agricultural soils, through organic matter amendments and conservation tillage, may thus help decrease the impacts of selenium contaminated drainage water on downstream aquatic ecosystems.
Seasonal leaf dynamics for tropical evergreen forests in a process-based global ecosystem model
Authors: De Weirdt M. , Verbeeck H. , Maignan F. , Peylin P. , Poulter B. , Bonal D. , Ciais P. , Steppe K.
Published: September 2012

Abstract. The influence of seasonal phenology on canopy photosynthesis in tropical evergreen forests remains poorly understood, and its representation in global ecosystem models is highly simplified, typically with no seasonal variation of canopy leaf properties taken into account. Including seasonal variation in leaf age and photosynthetic capacity could improve the correspondence of global vegetation model outputs with the wet–dry season CO2 patterns measured at flux tower sites in these forests. We introduced a leaf litterfall dynamics scheme in the global terrestrial ecosystem model ORCHIDEE based on seasonal variations in net primary production (NPP), resulting in higher leaf turnover in periods of high productivity. The modifications in the leaf litterfall scheme induce seasonal variation in leaf age distribution and photosynthetic capacity. We evaluated the results of the modification against seasonal patterns of three long-term in-situ leaf litterfall datasets of evergreen tropical forests in Panama, French Guiana and Brazil. In addition, we evaluated the impact of the model improvements on simulated latent heat (LE) and gross primary productivity (GPP) fluxes for the flux tower sites Guyaflux (French Guiana) and Tapajós (km 67, Brazil). The results show that the introduced seasonal leaf litterfall corresponds well with field inventory leaf litter data and times with its seasonality. Although the simulated litterfall improved substantially by the model modifications, the impact on the modelled fluxes remained limited. The seasonal pattern of GPP improved clearly for the Guyaflux site, but no significant improvement was obtained for the Tapajós site. The seasonal pattern of the modelled latent heat fluxes was hardly changed and remained consistent with the observed fluxes. We conclude that we introduced a realistic and generic litterfall dynamics scheme, but that other processes need to be improved in the model to achieve better simulations of GPP seasonal patterns for tropical evergreen forests.
Influence of basin connectivity on sediment source, transport, and storage within the Mkabela Basin, South Africa
Authors: Miller J. R. , Mackin G. , Lechler P. , Lord M. , Lorentz S.
Published: September 2012

Abstract. The management of sediment and other non-point source (NPS) pollution has proven difficult, and requires a sound understanding of particle movement through the drainage system. The primary objective of this investigation was to obtain an understanding of NPS sediment source(s), transport, and storage within the Mkabela basin, a representative agricultural catchment within the KwaZulu-Natal Midlands of southeastern South Africa, by combining geomorphic, hydrologic and geochemical fingerprinting analyses. The Mkabela Basin can be subdivided into three distinct subcatchments that differ in their ability to transport and store sediment along the axial valley. Headwater (upper catchment) areas are characterized by extensive wetlands that act as significant sediment sinks. Mid-catchment areas, characterized by higher relief and valley gradients, exhibit few wetlands, but rather are dominated by a combination of alluvial and bedrock channels that are conducive to sediment transport. The lower catchment exhibits a low-gradient alluvial channel that is boarded by extensive riparian wetlands that accumulate large quantities of sediment (and NPS pollutants). Fingerprinting studies suggest that silt- and clay-rich layers found within wetland and reservoir deposits are derived from the erosion of fine-grained, valley bottom soils frequently utilized as vegetable fields. Coarser-grained deposits within both wetlands and reservoirs result from the erosion of sandier hillslope soils extensively utilized for sugar cane, during relatively high magnitude runoff events that are capable of transporting sand-sized sediment off the slopes. Thus, the source of sediment to the axial valley varies as a function of sediment size and runoff magnitude. Sediment export from the basin was limited until the early 1990s, in part because the upper catchment wetlands were hydrologically disconnected from lower parts of the watershed during low- to moderate flood events. The construction of a drainage ditch through a previously unchanneled wetland altered the hydrologic connectivity of the catchment, allowing sediment to be transported from the headwaters to the lower basin where much of it was deposited within the riparian wetlands. The axial drainage system is now geomorphically and hydrologically connected during most events throughout the study basin. The study indicates that increased valley connectivity partly negated the positive benefits of controlling sediment/nutrient exports from the catchment by means of upland based, best management practices.
The mechanism of non-linear photochemical oscillations in the mesopause region
Authors: Kulikov M. Yu. , Vadimova O. L. , Ignatov S. K. , Feigin A. M.
Published: September 2012

Abstract. The mechanism of generation of 2-day photochemical oscillations in the mesopause region (80–90 km) has been studied analytically. The initial system of equations of chemical kinetics describing the temporal evolution of O, O3, H, OH and HO2 concentrations with allowance for diurnal variations of solar radiation has been simplified successively to a system of two nonlinear first-order time equations with sinusoidal external forcing. The obtained system has a minimum number of terms needed for generation of 2-day oscillations. Linearization of this system near the period-doubling threshold permits separating explicitly a particular case of the Mathieu equation ẍ + α · sin ω t · x = 0, in which the first sub-harmonic (ω/2) of the exciting force starts to grow exponentially when the amplitude of external forcing (α) exceeds its threshold value. Finally, a system of two simplest differential equations with power-law nonlinearity has been derived that allows analytical investigation of the effect of arising of reaction-diffusion waves in the mesospheric photochemical system.
Definition of Infection
Authors: Krismer Martin
Published: September 2012

Acute periprosthetic infections occur either early, due to perioperative contamination, or late and haematogenous, and are caused by virulent bacteria. Late chronic or delayed periprosthetic infections produce implant loosening or symptoms of articular pain, and are caused by low-virulence bacteria. The intension of the definitions characterising the virulence of bacteria are more important than exact periods (delayed from 4 weeks to 2 years, early before and late after this period).
Peri-Prosthetic Hip Infections: In Favour of One-Stage
Authors: Gehrke Thorsten , Kendoff Daniel
Published: September 2012

Although it does offer certain obvious advantages, the one-staged revision approach in infected THA remains rare in the field of orthopaedics. Besides the reduced number of surgical interventions for patients, it is associated with a decreased inpatient hospital stay and quicker mobilisation. Furthermore, it might be the more cost-effective approach and enables a reduced duration of post-operative systemic antibiotics, usually less than 14 days in our setting. Technically speaking, the presence of a positive culture of a pre-operative aspiration and respective antibiogram are mandatory requirements. A general cemented implant fixation using topical antibiotics is the treatment of choice for single-staged procedures. The key to surgical success is based on the well-defined and detailed intra-hospital infrastructure, including a meticulous pre-operative hip aspiration regime, pre-operative planning and an aggressive intra-operative surgical approach.
Bone Grafting and One-Stage Revision of THR - Biological Reconstruction and Effective Antimicrobial Treatment Using Antibiotic Impregnated Allograft Bone
Authors: Winkler Heinz
Published: September 2012

Infection of a total hip replacement (THR) is considered one of the most serious complications in orthopaedic surgery. Problems derive from the presence of biofilms with inherent resistance to usual antibiotic treatment and bone defects resulting from infection induced osteolysis. Discussions on the choice of treatment mainly focus on the chance of eradicating the infection in either one or more stages. The advantages of only one operation with regard to patients’ satisfaction, functional results and economical burden are evident. However, the fear of re-infection usually leads surgeons to multiple stage procedures, mostly using antibiotic loaded spacers in the interval. Spacers have no effect on biofilms and are associated with a high rate of complications such as breakage or dislocation. Cemented revisions show several disadvantages like reduction of biomechanical properties through added antibiotics, inferior long term results, difficulties of removal in case of recurrence etc. Uncemented implants appear more advantageous but are at risk of becoming colonised by remaining bio-film fragments. To overcome this risk higher local concentrations of antibiotics are needed.

Allograft bone may be impregnated with high loads of antibiotics using special incubation techniques, resulting in an antibiotic bone compound (ABC). ABC provides local concentrations exceeding those of cement by more than a 100-fold and efficient release is prolonged for several weeks. At the same time it is likely to restore bone stock, which is usually compromised after removal of an infected endoprosthesis. Based on these considerations new protocols for one-stage exchange of infected THR have been established. Bone voids may be filled with ABC, uncemented implants may be fixed in original healthy bone. Recent studies indicate an overall success rate of more than 90% with one operation, without any adverse side effects. Incorporation of allografts appears as after grafting with unimpregnated bone grafts. One stage revision using ABC together with uncemented implants, should be at least comparable to multiple stage procedures, but with the advantage of the obvious benefits for patients and cost.
Turning Ability in Stroke Survivors: A Review of Literature
Authors: Manaf Haidzir , Justine Maria , Omar Mazlifah , Md Isa Khairil Anuar , Salleh Zoolfaiz
Published: September 2012

The aim of this paper is to explore the research literature on the turning ability among stroke survivors. Stroke is one of the top five leading causes of death and disability in Malaysia. Stroke survivors reported a higher rate of fall incidences with turning while walking has been the major contributor in most of the incidences. The attentional task requires stroke survivors to have higher cognitive and attention function, and sound muscle coordination in order to perform multitask activities such as driving, walking and turning while talking, carrying an object (holding a plastic bag), navigating corners and overcoming obstacles within the base of support. Most of the previous studies have focused on the kinematic and gait parameters measurement of turning ability among stroke survivors. However, studies conducted on muscle activity using electromyography to evaluate the time pattern of muscle contraction during turning event is lacking. With regards to dual-task ability among stroke survivors, there is insufficient information or research into dual task (motor and cognitive) ability during turning. Further studies are needed to understand the effects of dual-task activity on muscle activity and gait parameters and how this impairment affects the turning ability. This needs to be addressed in order to prevent falls among stroke survivors.