bluuebunny/crossref_metadata_2025 huggingface dataset:
Restriction mapping of βS locus among tunisian sickle‐cell patients
Authors: Imen Moumni , Ikbel Ben Mansour Mosbehi , Leila Chaouch , Fethi Mellouli , Amine Zorai , Mohamed Bejaoui , Salem Abbes
Published: September 2011

Objectives: The polymorphism of the β‐globin gene haplotypes and frameworks is useful in the determination of the unicentric and multicentric origin of a mutational event. In our study, the haplotypes linked to the Tunisian βS mutation are determined to improve our knowledge of the chromosomal background of the β‐globin gene in sickle‐cell anemia in Tunisia.

Methods: The authors have investigated 242 unrelated individuals. Haplotype analysis was carried out by polymerase chain reaction‐restriction fragment length polymorphism‐based methods. Seven polymorphic sites in the β‐globin gene cluster were examined. The correlation of these various haplotypes with Hb F expression was studied.

Results: The Benin haplotype (Ben) was largely predominant (60.54%) followed by the Atypical haplotype A (8.43%) and Bantu (Ban) (2.71%) haplotypes. A total of 94 chromosomes had atypical haplotypes, 78 (23.49%) had A1 [−−−−−++], 11 (3.31%) had A2 [−−−−−−−], and five (1.5%) had B1 [−−+−−++]. The Benin haplotype is associated with a fairly low HbF levels.

Conclusion: The very high frequency of the Benin haplotype in our study suggests that the βS mutation present in Tunisia may have originated from the Benin region and was brought to Tunisia along the slave trade routes. However, another atypical haplotype observed a new emergence in our population and could be considered as specific to Tunisian chromosome βS. Am. J. Hum. Biol., 2011. © 2011 Wiley‐Liss, Inc.
Phenotypic heterogeneity in Woodhouse–Sakati syndrome: Two new families with a mutation in the C2orf37 gene
Authors: Ben‐Omran Tawfeg , Ali Rehab , Almureikhi Mariam , Alameer Seham , Al‐Saffar Muna , Walsh Christopher A. , Felie Jillian M. , Teebi Ahmad
Published: September 2011

Hypogonadism, alopecia, diabetes mellitus, mental retardation, and extrapyramidal syndrome [also known as Woodhouse–Sakati syndrome (WSS)] is a rare autosomal recessive neuroendocrine and ectodermal disorder. The syndrome was first described by Woodhouse and Sakati in 1983, and 47 patients from 23 families have been reported so far. We report on an additional seven patients (four males and three females) from two highly consanguineous Arab families from Qatar, presenting with a milder phenotype of WSS. These patients show the spectrum of clinical features previously found in WSS, but lack evidence of diabetes mellitus and extrapyramidal symptoms. These two new families further illustrate the natural course and the interfamilial phenotypic variability of WSS that may lead to challenges in making the diagnosis. In addition, our study suggests that WSS may not be as infrequent in the Arab world as previously thought. © 2011 Wiley Periodicals, Inc.
Atypical presentation of pseudoxanthoma elasticum with abdominal cutis laxa: Evidence for a spectrum of ectopic calcification disorders?
Authors: Vanakker Olivier M. , Leroy Bart P. , Schurgers Leon J. , Vermeer Cees , Coucke Paul J. , De Paepe Anne
Published: September 2011

A patient is presented with severe cutis laxa of the abdomen. Molecular investigations, including sequencing of the fibulin‐5 and elastin gene, failed to endorse the diagnosis of inherited cutis laxa. Ultrasonographical discovery of renal calcifications during his general work‐up suggested a possible diagnosis of pseudo‐xanthoma elasticum (PXE). A discrete yellowish reticular pattern in the anterior neck region was detected upon careful clinical examination. Clinically, the patient presented characteristics of both classic PXE (retinopathy, renal calcifications) and the PXE‐like syndrome (cutis laxa beyond the flexural areas). Skin biopsy and ophthalmological examination confirmed the diagnosis of PXE. In addition, ultrastructural evaluation revealed calcium deposits in the periphery of elastic fibers, a typical observation in the PXE‐like syndrome. Immunohistochemical experiments and ELISA tests for various inhibitors of calcification displayed results which were partly reminiscent of both PXE and the PXE‐like syndrome. Molecular analysis revealed not only two ABCC6 mutations (related to PXE), but also a gain of function SNP in the GGCX gene, in which loss‐of‐function mutations cause the PXE‐like syndrome. We conclude that the patients phenotype and—to a further extent—the PXE‐like syndrome, are part of a spectrum of ectopic calcification disorders which are clinically and/or pathogenetically related to PXE. The molecular findings in this patient are however insufficient to explain the entire phenotype and suggest a role for multiple genetic factors in soft tissue mineralization. © 2011 Wiley Periodicals, Inc.
Synthesis, spectral, and thermal characterization of photoreactive epoxy resin containing cycloalkanone moiety in the main chain
Authors: Devi R. , Murugavel S. C.
Published: September 2011

Dual functional epoxy resins were synthesized by solution polycondensation of 2,6‐bis(4‐hydroxy‐3‐methoxy benzylidene)cyclohexanone and 2,5‐bis(4‐hydroxy‐3‐methoxy benzylidene)cyclopentanone with epichlorohydrin. The synthesized epoxy resins were characterized systematically for their structure by UV, Fourier transform infrared (FTIR), 1H NMR, and 13C NMR spectroscopic techniques. Thermal characterization of synthesized epoxy resins was carried out by thermogravimetric analysis, and differential scanning calorimetry (DSC) under nitrogen atmosphere. The self extinguishing property of synthesized oligomers was studied by determining limiting oxygen index (LOI) values using Van Krevelen's equation. X‐ray analysis showed that the epoxy resins containing cyclopentanone have higher degree of crystallinity. The photoreactive property of the synthesized epoxy resins in solution and film states was investigated by UV–Vis spectroscopy. The photocross‐linking proceeds through the dimerization of olefinic chromophore present in the main chain of the oligomer via 2π + 2π cycloaddition reaction. The influence of photoacid generator on the rate of photocross‐linking of epoxy resin was studied by FTIR. UV irradiation of the epoxy resin in presence of photoacid generator produces aromatic sulfonium cation radicals and aromatic radicals which initiate the cationic ring‐opening polymerization of oxirane ring. The photoreactivity studies of the oligomers by FTIR and DSC indicated the presence of dual functionality in the synthesized epoxy resins. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Comparative metabolite analysis to understand lactate metabolism shift in Chinese hamster ovary cell culture process
Authors: Luo Jun , Vijayasankaran Natarajan , Autsen Jennifer , Santuray Rodell , Hudson Terry , Amanullah Ashraf , Li Feng
Published: September 2011

A metabolic shift from lactate production (LP) to net lactate consumption (LC) phenotype was observed in certain Chinese hamster ovary (CHO) cell lines during the implementation of a new chemically defined medium (CDM) formulation for antibody production. In addition, this metabolic shift typically leads to process performance improvements in cell growth, productivity, process robustness, and scalability. In our previous studies, a correlation between a key media component, copper, and this lactate metabolism shift was observed. To further investigate this phenomenon, two complementary studies were conducted. In the first study, a single cell line was cultivated in two media that only differed in their copper concentrations, yet were known to generate an LP or LC phenotype with that cell line. In the second study, two different cell lines, which were known to possess inherently different lactate metabolic characteristics, were cultivated in the same medium with a high level of copper; one cell line produced lactate throughout the duration of the culture, and the other consumed lactate after an initial period of LP. Cell pellet and supernatant samples from both studies were collected at regular time intervals, and their metabolite profiles were investigated. The primary finding from the metabolic analysis was that the cells in LP conditions exhibited a less efficient energy metabolism, with glucose primarily being converted into pyruvate, sorbitol, lactate, and other glycolytic intermediates. This decrease in energy efficiency may be due to an inability of pyruvate and acetyl‐CoA to progress into the TCA cycle. The lack of progression into the TCA cycle or overflow metabolism in the LP phenotype resulted in the inadequate supply of ATP for the cells. As a consequence, the glycolysis pathway remained the major source of ATP, which in turn, resulted in continuous LP throughout the culture. In addition, the accumulation of free fatty acids was observed; this was thought to be a result of phospholipid catabolism that was being used to supplement the energy produced through glycolysis in order to meet the needs of LP cells. A thorough review of the metabolic profiles indicated that the lactate metabolic shift could be related to the oxidative metabolic capacity of cells. Biotechnol. Bioeng. 2012;109: 146–156. © 2011 Wiley Periodicals, Inc.
Determination of the Effect of Aeration Rate on Composting of Vegetable–Fruit Wastes
Authors: Arslan E. Işıl , Ünlü Ayhan , Topal Murat
Published: September 2011

In this study, it was aimed to determine the effect of various aeration rates on composting to supply the optimum aeration rate for a successful and economic composting. For this aim, vegetable–fruit wastes (VFW) were composted at various aeration rates (0.37, 0.49, 0.62, 0.74, 0.86, and 0.99 L/min kg VS) and moisture, temperature, pH, electrical conductivity, C/N, and cellulose were investigated. Moistures of the reactor that had the highest aeration were generally lower than those of the others. Reactor that had the lowest aeration reached thermophilic phase earlier than the others and stayed more days. This situation was opposite for the reactor that had the highest aeration. pH variations with aeration rates were not significant. Although electrical conductivity did not differ significantly with aeration rates, at the beginning of the thermophilic phase it generally increased with the increase in aeration. The highest C/N reduction was observed in the reactor that had an aeration of 0.62 L/min kg VS. The final cellulose contents were close to each other. It could be said that aeration rates used were efficient on composting of VFW. Taking the C/N into account which is the parameter of the indicator of the stabilization in composting, it could be said that the optimum aeration rate for forced aerobic composting of VFW was 0.62 L/min kg VS.
Lactobacillus casei Zhang stimulates lipid metabolism in hypercholesterolemic rats by affecting gene expression in the liver
Authors: Zhong Zhi , Zhang Wenyi , Du Ruiting , Meng He , Zhang Heping
Published: September 2011

In this study, we show that administration of Lactobacillus casei Zhang evokes a significant reduction in the levels of cholesterol, triglycerides (TGs), and low‐density lipoprotein cholesterol (LDL‐C) from the serum and liver of hypercholesterolemic rats. After administration of L. casei Zhang, there was 31.5 and 30.8% reduction in the levels of serum TG and LDL‐C. DNA microarray results revealed that 755 genes, mainly involved in biological regulation, and cellular and metabolic processes, were differentially expressed in the liver from rats treated with probiotic bacteria, wherein, 324 genes were up‐regulated and 431 were down‐regulated, respectively. In the up‐regulated group, we characterized genes including Acsl1, Hadh, Acaa2, Acads, and gcdH, which are involved in β‐oxidation of fatty acids and encodes enzymes catalyzing critical steps for CoA synthesis and dehydrogenation. It is possible that Lactobacillus could accelerate the fatty acid catabolism by enhancing β‐oxidation step, thus reducing the level of free fatty acid and TG in the serum and liver. Subsequently, it may trigger lipid homeostasis that converts TGs, which are the main storage form of fatty acids, into free fatty acids, and lower TG concentrations both in the serum and liver.

Practical applications: Lactobacillus casei Zhang has the ability to reduce cholesterol level in the blood by stimulating gene expression related to lipid metabolism, particularly through β‐oxidation of fatty acids in liver, thereby, making it an effective candidate probiotic to treat hypercholesterolemia. The findings of this study should provide very useful information in understanding the molecular mechanism of the hypocholesterolemic effect of the strain in an animal model.
Local disruption of glial adenosine homeostasis in mice associates with focal electrographic seizures: A first step in epileptogenesis?
Authors: Li Tianfu , Lytle Nikki , Lan Jing‐Quan , Sandau Ursula S. , Boison Detlev
Published: September 2011

Astrogliosis and associated dysfunction of adenosine homeostasis are pathological hallmarks of the epileptic brain and thought to contribute to seizure generation in epilepsy. The authors hypothesized that astrogliosis—an early component of the epileptogenic cascade—might be linked to focal seizure onset. To isolate the contribution of astrogliosis to ictogenesis from other pathological events involved in epilepsy, the authors used a minimalistic model of epileptogenesis in mice, based on a focal onset status epilepticus triggered by intra‐amygdaloid injection of kainic acid. The authors demonstrate acute neuronal cell loss restricted to the injected amygdala and ipsilateral CA3, followed 3 weeks later by focal astrogliosis and overexpression of the adenosine‐metabolizing enzyme adenosine kinase (ADK). Using synchronous electroencephalographic recordings from multiple depth electrodes, the authors identify the KA‐injected amygdala and ipsilateral CA3 as two independent foci for the initiation of non‐synchronized electrographic subclinical seizures. Importantly, seizures remained focal and restricted to areas of ADK overexpression. However, after systemic application of a non‐convulsive dose of an adenosine A1‐receptor antagonist, seizures in amygdala and CA3 immediately synchronized and spread throughout the cortex, leading to convulsive seizures. This focal seizure phenotype remained stable over at least several weeks. We conclude that astrogliosis via disruption of adenosine homeostasis per se and in the absence of any other overt pathology, is associated with the emergence of spontaneous recurrent subclinical seizures, which remain stable over space and time. A secondary event, here mimicked by brain‐wide disruption of adenosine signaling, is likely required to turn pre‐existing subclinical seizures into a clinical seizure phenotype. © 2011 Wiley Periodicals, Inc.
AN AHP MODEL FOR CROP PLANNING WITHIN IRRIGATION COMMAND AREAS
Authors: Montazar Aliasghar , Gaffari Ahmad
Published: September 2011

Crop planning decisions are complex due to a number of constraints, the desire to secure crop diversification and the involvement of various affected parameters. In the present study, a multi‐criteria technique, an analytical hierarchy process (AHP), is considered a promising framework for selecting adequate cropping patterns in an irrigation command area. The approach is illustrated using data from the Varamin Irrigation Network in I.R. Iran. Ten attribute decisions are considered for ranking the type of crop in the cropping system. These criteria are assumed nine attributes for determination of the crop cultivation area. The results show that the AHP can synthesize various sets of criteria in the preferred elicitation of the type and the cultivated area. It is concluded that AHP can be used to aggregate preferences in order to obtain a group decision, improve understanding of the choice problem, accommodate multiple objectives and increase transparency and credibility in decision making by actively involving relevant criteria in the crop planning. Further research could include a useful extension of the methodology, which could be devised by using other multi‐objective methods and incorporating fuzzy set theory. Copyright © 2011 John Wiley & Sons, Ltd.
Tumor detection from enhanced magnetic resonance imaging using fuzzy curvelet
Authors: Jaffar M. Arfan , Ain Quratul , Choi Tae Sun
Published: September 2011

Effective medical image analysis is possible by the use of technique known as segmentation. Segmentation is a very challenging task because there is not any standard segmentation method is available for any medical application. In this article, we have proposed an automatic brain MR image segmentation method. Fast discrete curvelet transform and spatial fuzzy C‐mean algorithm is used for noise removal and segmentation of brain MR image. Fuzzy entropy has been used for calculating adaptive and optimal threshold to separate out the image segments. Our proposed system is exclusively based on the information contained by the image itself. No extra information and no human intervention are required in our proposed system. We have tested our proposed system on different T1, T2 and PD brain MR images. Microsc. Res. Tech., 2011. © 2011 Wiley‐Liss, Inc.
Manganese‐enhanced MRI reveals multiple cellular and vascular layers in normal and degenerated retinas
Authors: Nair Govind , Pardue Machelle T. , Kim Moon , Duong Timothy Q.
Published: September 2011

Purpose:

To use manganese‐enhanced magnetic resonance imaging (MEMRI) at 25 × 25 × 800 μm3 to image different retinal and vascular layers in the rat retinas.

Materials and Methods:

Manganese‐chloride was injected intraocularly in normal (n = 5) and Royal College of Surgeons (RCS, an model of photoreceptor degeneration) (n = 5) rats at postnatal day 90. MEMRI at 4.7 T was performed 24 hours later. MRI was repeated following intravenous Gd‐DTPA in the same animals to highlight the vasculatures. Layer assignment and thickness were compared to histology.

Results:

MEMRI 24 hours after intravitreal manganese‐chloride injection revealed seven bands of alternating hyper‐ and hypointensities, corresponding histologically to the ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, photoreceptor‐segment layer, and choroidal vascular layer. Intravenous Gd‐DTPA—which does not cross the blood–retinal barrier and the retinal pigment epithelium—further enhanced the two layers bounding the retina, corresponding to the retinal and choroidal vascular layers, but not the avascular outer nuclear layer and the photoreceptor‐segment layer. MEMRI of the RCS retinas revealed the loss of the outer plexiform layer, outer nuclear layer, and photoreceptor‐segment layer. Histological analysis corroborated the MRI laminar assignments and thicknesses.

Conclusion:

Lamina‐specific retinal structures neurodegenerative changes to structure in retinal diseases can be detected using MEMRI. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Magnetic resonance imaging measurement reproducibility for calf muscle and adipose tissue volume
Authors: Commean Paul K. , Tuttle Lori J. , Hastings Mary K. , Strube Michael J. , Mueller Michael J.
Published: September 2011

Purpose:

To describe a new semiautomated method for segmenting and measuring the volume of the muscle, bone, and adipose (subcutaneous and intermuscular) tissue in calf muscle compartments using magnetic resonance (MR) images and determine the intrarater and interrater reproducibility of the measures.

Materials and Methods:

Proton‐density weighted MR images were acquired from the right calf of 21 subjects. Three raters segmented and measured the volumes of bones, adipose tissue, and five individual muscle compartments. Two raters repeated the segmentations. The intra‐ and interrater reproducibility of the measures (intraclass correlation coefficients; ICC) were determined using generalizability theory.

Results:

All ICC values were greater than 0.96. The average standard error of the mean (SEM) of all measures was 1.21 cm3 and none were greater than 2.3 cm3. Essentially all variation (≥97% for all measures) was due to subject differences, indicating low error in the measurements.

Conclusion:

The volumetric measurements for the bones, adipose tissue, and muscle in each of the compartments using MRI were highly reproducible. MRI can provide quantitative, reproducible volumetric measures of bone, adipose tissue, and individual muscle compartments in the calf. We believe these methods can be used to quantify specific muscle or adipose volumetric measures for other clinical or research purposes. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Impact of partial volume effects on visceral adipose tissue quantification using MRI
Authors: Zhou Anqi , Murillo Horacio , Peng Qi
Published: September 2011

Purpose:

To quantitatively estimate the impact of partial volume effects on visceral adipose tissue (VAT) quantification using typical resolution magnetic resonance imaging (MRI).

Materials and Methods:

Nine normal or overweight subjects were scanned at central abdomen levels with a water‐saturated, balanced steady‐state free precession (b‐SSFP) sequence. The water‐saturation effectiveness was evaluated with region‐of‐interest analysis on fat, muscle, bowel, and noise areas. The number of full‐volume (FV) and partial‐volume (PV) fat pixels was estimated based on a gray‐level histogram model of water‐saturated images. Both FV and PV fat amounts were quantified.

Results:

High‐quality, fat‐only images were generated with the b‐SSFP imaging method. Fat SNR was 77.7 ± 25.6 and water‐saturation was effective, with the average fat‐to‐water signal intensity ratio = 20.7 ± 3.8. The average ratio of partial‐ to full‐volume fat amounts was 104.0%. The ratio was higher with lower body mass index (BMI) and PV fat amount only increased slightly when BMI increased.

Conclusion:

PV fat contributes a significant amount of fat to fat measurements on typical spatial resolution MRI on normal and overweight subjects. The relative PV fat contribution is markedly higher in slimmer patients. Inclusion of this portion of the adipose tissue will increase overall accuracy and decrease variability of VAT quantification using MRI. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
On stackelberg pricing with computationally bounded customers
Authors: Briest Patrick , Gualà Luciano , Hoefer Martin , Ventre Carmine
Published: September 2011

In Stackelberg pricing a leader sets prices for items to maximize revenue from a follower purchasing a feasible subset of items. We consider computationally bounded followers who cannot optimize exactly over the range of all feasible subsets, but who apply publicly known algorithms to determine the items to purchase. This corresponds to general multidimensional pricing when customers cannot optimize their valuation functions efficiently but still aim to act rationally to the best of their ability. We consider two versions of this novel type of pricing problem. In the MIn‐KNAPSACK variant items are weighted objects and the follower seeks to purchase a min‐cost selection of objects of some bounded weight. When he uses a greedy 2‐approximation algorithm, we provide a polynomial‐time (2+ε) ‐approximation algorithm for the leader's revenue maximization problem based on so‐called near‐uniform price assignments. We also prove the problem to be strongly NP‐hard. In the SET‐COVER variant items are subsets of some ground set which the follower seeks to cover. When he uses a standard primal‐dual approach, we prove that exact revenue maximization is possible in polynomial time when elements have frequency 2 (VERTEX‐COVER variant). This stands in sharp contrast to APX‐hardness for the problem with elements of frequency 3. © 2011 Wiley Periodicals, Inc. NETWORKS, 2012
Depressed mothers as informants on child behavior: Methodological issues
Authors: Ordway Monica Roosa
Published: September 2011

Mothers with depressive symptoms more frequently report behavioral problems among their children than non‐depressed mothers leading to a debate regarding the accuracy of depressed mothers as informants of children's behavior. The purpose of this integrative review was to identify methodological challenges in research related to the debate. Data were extracted from 43 articles (6 theoretical, 36 research reports, and 1 instrument scoring manual). The analysis focused on the methodologies considered when using depressed mothers as informants. Nine key themes were identified and I concluded that researchers should incorporate multiple informants, identify the characteristics of maternal depression, and incorporate advanced statistical methodology. The use of a conceptual framework to understand informant discrepancies within child behavior evaluations is suggested for future research. © 2011 Wiley Periodicals, Inc. Res Nurs Health 34:520–532, 2011
There is no way to identify patients who will harbor small volume, unilateral prostate cancer at final pathology. Implications for focal therapies
Authors: Briganti Alberto , Tutolo Manuela , Suardi Nazareno , Gallina Andrea , Abdollah Firas , Capitanio Umberto , Freschi Massimo , Bianchi Marco , Salonia Andrea , Colombo Renzo , Rigatti Patrizio , Montorsi Francesco
Published: September 2011

BACKGROUND

The aim of this study was to assess the clinical characteristics of the potentially ideal candidates for focal therapy, that is, patients with unilateral, small volume (namely, pT2a) prostate cancer (PCa) at radical prostatectomy (RP).

MATERIALS AND METHODS

We evaluated 2,503 consecutive pT2 PCa patients treated with RP between 2002 and 2009 at a single center. Within this population, the clinical characteristics of patients with pT2a and pT2b/c disease were compared. Univariable and multivariable logistic regression models were fitted to assess clinical predictors of pT2a at RP.

RESULTS

Overall, 349 patients (14%) had pT2a PCa, while the remaining patients had either pT2b (n = 334; 15.5%) or pT2c disease (n = 1,820 patients; 84.5%). Patients with pT2a PCa had a significantly lower mean PSA value, lower mean percentage of positive biopsy cores and lower biopsy Gleason score distribution (all P ≤ 0.03). However, at multivariable analyses, only percentage of positive cores maintained an independent predictor status (P = 0.01). Even when considering only patients sharing all the most favorable PCa characteristics (namely, clinical stage T1, PSA ≤ 4, Gleason score ≤6 and percentage of positive cores ≤25%), the rate of pT2a disease was only 24%.

CONCLUSIONS

The rate of small volume, unilateral PCa even among patients with extremely favourable PCa characteristics was remarkably low (roughly 25%). This suggests that: (1) Three quarters of the best candidates for focal therapy would ultimately show adverse pathological features; (2) At present, accurate identification of the ideal candidate for focal therapy is not possible with current clinical‐pathologic parameters. Prostate 72:925–930, 2012. © 2011 Wiley Periodicals, Inc.
Local photoconductivity of microcrystalline silicon thin films measured by conductive atomic force microscopy
Authors: Ledinský Martin , Fejfar Antonín , Vetushka Aliaksei , Stuchlík Jiří , Rezek Bohuslav , Kočka Jan
Published: September 2011

Local currents measured under standard conductive atomic force microscopy (C‐AFM) conditions on microcrystalline silicon (µc‐Si:H) thin films were studied. It was shown that the AFM detection diode illuminating the AFM cantilever (see the figure on the right side) 100× enhanced the current flows through the photosensitive µc‐Si:H layer. The local current map and current–voltage characteristics were measured under dark conditions. This study enables mapping of both the dark current and photocurrent.

magnified image

C‐AFM cantilever illuminated by the detection diode during measurement on µc‐Si:H thin film.

(© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Planning and financial performance of small, mature firms
Authors: Bracker Jeffre Y. S. , Pearson John N.
Published: September 2011

This article develops a classification scheme of planning process sophistication in small firms, categorizes small firms according to planning process sophistication, and examines the relationship between planning process sophistication and the financial performance of a select group of small, mature firms. The study overcomes several methodological shortcomings of prior research on strategic planning and firm performance. Multivariate analysis of variance is used to identify statistically significant differences between the financial performance data of firms that employ structured, strategic plans and those that do not. The results confirm previous research on strategic planning and financial performance. Finally, recommendations are made for future research.
A project‐based approach to competitive analysis
Authors: Prescott John E. , Smith Daniel C.
Published: September 2011

While comprehensive, ongoing competitive intelligence systems generate valuable input for broad strategic decisions, they often fail to provide the specific actionable information needed by managers operating in a project‐oriented environment. This paper proposes a project‐based framework for competitive analysis. The framework was developed from field reseach involving 16 projects. A comparison of project‐based and comprehensive competitive analysis systems is made to illustrate their differences. A case example from field research is utilized to illustrate concepts central to this approach and its practical utility. A set of guidelines regarding pitfalls to avoid in project‐based competitive analysis is presented.
Global strategy: An organizing framework
Authors: Ghoshal Sumantra
Published: September 2011

Global strategy has recently emerged as a popular concept among managers of multinational corporations as well as among researchers and students in the field of international management. This paper presents a conceptual framework encompassing a range of different issues relevant to global strategies. The framework provides a basis for organizing existing literature on the topic and for creating a map of the field. Such a map can be useful for teaching and also for guiding future research in this area. The article, however, is primarily directed at managers of multinational corporations, and is aimed at providing them with a basis for relating and synthesizing the different perspectives and prescriptions that are currently available for global strategic management.
The emerging paradigm of strategic behavior
Authors: Ansoff H. Igor
Published: September 2011

Several apparently conflicting empirically tested theories have been advanced as explanations of strategic behavior. This paper suggests that the theories differ because they were based on observations of organizations in different environmental settings. The paper proposes a paradigmic framework which legitimizes and accommodates the respective theories.
Application of Variable Life Adjusted Display (VLAD) to Risk‐Adjusted Mortality of Esophagogastric Cancer Surgery
Authors: Guest R. V. , Chandrabalan V. V. , Murray G. D. , Auld C. D.
Published: September 2011

Purpose

In the new era of revalidation, there is an increasing need to measure surgical outcome objectively. We apply a graphical method, the Variable Life Adjusted Display (VLAD), to esophagogastric resection for malignancy. This technique charts the cumulative difference between expected and actual risk‐adjusted mortality over time, allowing observation of performance trends irrespective of case‐mix.

Methods

P‐POSSUM was applied retrospectively to 182 consecutive patients who underwent resection for esophageal or gastric malignancy in a district general hospital. The primary outcome measured was 30‐day mortality.

Results

A total of 168 patients were eligible for inclusion, with a median age of 68 years. The overall 30‐day mortality rate was 4.2% compared with 7.1% as predicted by P‐POSSUM. The resulting VLAD plot demonstrates an upward trend of better than predicted surgical performance.

Conclusions

VLAD has been hereby applied to esophagogastric surgery and has graphically demonstrated risk‐adjusted trends in a single general surgeon’s performance. For qualitative comparative purposes, including recertification, VLAD is judged to be a simple, directly interpretable, and useful technique for monitoring surgical performance.
An examination of Edward Inglefield's 1852 voyage into Jones Sound
Authors: Graville Brian
Published: September 2011

Edward Augustus Inglefield is usually credited with penetrating Jones Sound to 84°W longitude during his Franklin search voyage of 1852. His chart of the region including Coburg Island replaced Horatio Austin's chart made in 1851 and became the accepted standard until the 20th century. By analysing Inglefield's map of Coburg Island it is shown that he made several errors in navigation and surveying which resulted in him believing he was further west than he really was and overestimating his speed. The results suggest he mistook Stewart Islands for Cone and Smith Islands and that his Sir Robert Inglis Peak reportedly seen near 84°W was actually Cone Island. Thus his penetration of Jones Sound was no further than Austin's the year before and the ready acceptance of his charts set back the mapping of that region of the Arctic for three quarters of a century.
Allometry of emergent tree species from saplings to above-canopy adults in a Costa Rican rain forest
Authors: King David A. , Clark Deborah A.
Published: September 2011

Relations between crown width and tree height and trunk diameter and tree height were measured for trees of all sizes of six large emergent species (Balizia elegans, Dipteryx panamensis, Hieronyma alchorneoides, Hymenolobium mesoamericanum, Lecythis amplaandTerminalia oblonga) in the lowland tropical wet forest at La Selva, Costa Rica. Thirty to 45 individuals were chosen per species to provide a relatively even height distribution from 1 m up to the maximum encountered height. Among small juveniles, the crown widths of the two species with the smallest leaves and horizontally spreading branches were greater than those of the four large-leaved species. On reaching and exceeding the canopy, all but one species showed pronounced increases in crown width with increasing height. These patterns are linked to leaf size and first branching height in small juveniles and low densities of emergent trees at La Selva and other tropical forests, where crown expansion in all directions enhances light interception under the equatorial sun in trees that are not crowded by neighbours of similar height.
Soil disturbance by vertebrates alters seed predation, movement and germination in an African rain forest
Authors: Dunham Amy E.
Published: September 2011

Biopedturbation, or animal-caused soil disturbance, may be important for development and maintenance of small-scale heterogeneity in ecosystems with the potential to alter seed mortality and recruitment. However, its role in tropical forests has been largely ignored. This study explored effects of vertebrate biopedturbation on seed (1) microsite heterogeneity, (2) predation and (3) germination in a West African rain forest. Exclosure experiments were used to study how biopedturbation altered burial and movements of seeds of four common canopy species. Effect of seed burial on removal by seed predators was also examined. Germination of the dominant canopy species (Raphia palma-pinus) in swamp forest was tested within artificial disturbances mimicking that of a locally common but endangered mammal, the Liberian mongoose (Liberiictis kuhni), which was estimated to turn over the entire forest floor in this habitat in c. 8 mo. Seed exposure to biopedturbation for 20 d (n = 80) led to an overall 6.5-fold increase in small-scale horizontal movement and increased probability of burial (6–52% higher), varying by species. Burial effectively eliminated seed removal for all four species (n = 160) by seed predators over 20 d. Germination of Raphia palma-pinus seeds (n = 100) was enhanced by 17.5% on average over 4 mo in simulated disturbances. Results suggest biopedturbation may be important for seedling recruitment and that loss of species with this functional role could have underappreciated yet important impacts on tropical plant communities.
Abundance of gall-inducing insect species in sclerophyllous savanna: understanding the importance of soil fertility using an experimental approach
Authors: Cuevas-Reyes Pablo , De Oliveira-Ker Fabricio T. , Fernandes Geraldo Wilson , Bustamante Mercedes
Published: September 2011

Although many studies have now demonstrated that both richness and abundance of gall-inducing insect species are directly and indirectly (via the host plant) influenced by soil quality, the empirical evaluation of it in the field remains anecdotal at best. The effects of soil fertility on richness and abundance of gall-inducing insects associated with a widespread savanna species,Eremanthus glomerulatus, were evaluated under experimental field conditions in Brasilia, central Brazil. The effect of soil fertility on gall-inducing insects species richness was evaluated using three treatments: (1) plots fertilized with nitrogen; (2) plots fertilized with phosphorus; and (3) control plots: soils without fertilization. Species richness of gall-inducing insects (six species of Cecidomyiidae) did not differ among the treatments. Leaves with galls had higher nitrogen concentrations (mean = 15.0 ± 0.5 mg g−1), compared with leaves without galls (mean = 9.0 ± 0.7 mg g−1) on plants that occurred in soils with addition of nitrogen. Similarly, leaves with galls had higher foliar phosphorus concentration (mean = 1.0 ± 0.04 mg g−1) than leaves without galls (mean = 0.6 ± 0.05 mg g−1) in plots with addition of phosphorus. In galled leaves, a negative relationship between gall density and nitrogen concentration was found for one gall-inducing insect species, while three species showed a positive relationship between gall density and leaf nitrogen concentration. A negative relationship between gall density and concentration of leaf phosphorus was observed for four of the six gall-inducing insect species studied. No relationship was found between gall density and leaf nitrogen and phosphorus concentration in ungalled leaves. We argue that foliar nitrogen and phosphorus concentration respond to gall density in galled leaves and therefore, gall-inducing insect species are capable of manipulating their host plant, modifying the foliar nutrients ofE. glomerulatusin sclerophyllous savanna.
CEC‐normalized clay‐water sorption isotherm
Authors: Woodruff W. F. , Revil A.
Published: September 2011

A normalized clay‐water isotherm model based on BET theory and describing the sorption and desorption of the bound water in clays, sand‐clay mixtures, and shales is presented. Clay‐water sorption isotherms (sorption and desorption) of clayey materials are normalized by their cation exchange capacity (CEC) accounting for a correction factor depending on the type of counterion sorbed on the mineral surface in the so‐called Stern layer. With such normalizations, all the data collapse into two master curves, one for sorption and one for desorption, independent of the clay mineralogy, crystallographic considerations, and bound cation type; therefore, neglecting the true heterogeneity of water sorption/desorption in smectite. The two master curves show the general hysteretic behavior of the capillary pressure curve at low relative humidity (below 70%). The model is validated against several data sets obtained from the literature comprising a broad range of clay types and clay mineralogies. The CEC values, derived by inverting the sorption/adsorption curves using a Markov chain Monte Carlo approach, are consistent with the CEC associated with the clay mineralogy.
On stable entire solutions of semi-linear elliptic equations with weights
Authors: Cowan Craig , Fazly Mostafa
Published: September 2011

We are interested in the existence versus non-existence of non-trivial stable sub- and super-solutions of

−
div
⁡
(

ω
1

∇
u
)
=

ω
2

f
(
u
)

in
 
 

R

N

,

\begin{equation} -\operatorname {div}( \omega _1 \nabla u) = \omega _2 f(u) \qquad \text {in}\ \ \mathbb {R}^N, \end{equation}

with positive smooth weights

ω
1

(
x
)
,

ω
2

(
x
)

\omega _1(x),\omega _2(x)

. We consider the cases

f
(
u
)
=

e
u

,

u
p

f(u) = e^u, u^p

where

p
>
1

p>1

and

−

u

−
p

-u^{-p}

where

p
>
0

p>0

. We obtain various non-existence results which depend on the dimension

N
N

and also on

p
p

and the behaviour of

ω
1

,

ω
2

\omega _1,\omega _2

near infinity. Also the monotonicity of

ω
1

\omega _1

is involved in some results. Our methods here are the methods developed by Farina. We examine a specific class of weights

ω
1

(
x
)
=
(

|

x

|

2

+
1

)

α
2

\omega _1(x) = ( |x|^2 +1)^\frac {\alpha }{2}

and
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="omega 2 left-parenthesis x right-parenthesis equals left-parenthesis StartAbsoluteValue x EndAbsoluteValue squared plus 1 right-parenthesis Superscript StartFraction beta Over 2 EndFraction Baseline g left-parenthesis x right-parenthesis">

ω
2

(
x
)
=
(

|

x

|

2

+
1

)

β
2

g
(
x
)

\omega _2(x) = ( |x|^2+1)^\frac { \beta }{2} g(x)

, where

g
(
x
)

g(x)

is a positive function with a finite limit at

∞
\infty

. For this class of weights, non-existence results are optimal. To show the optimality we use various generalized Hardy inequalities.
Parsimonious Multi‐dimensional Impact Assessment
Authors: Antle John M.
Published: September 2011

This article develops the conceptual and empirical foundations for a parsimonious, generic modeling approach to multi‐dimensional (i.e., economic, environmental and social) impact assessments of agricultural technologies and environmental change. Joint distributions between technology adoption and outcome variables are characterized, and used to analyze the selection effects of adoption on a general class of impact indicators. The approach is implemented with a generic model that can be parameterized with low‐order moments of outcome variables. A case study of adoption of a high‐yielding maize variety in Kenya illustrates the model's use and confirms theoretical results.
Downward causation by information control in micro-organisms
Authors: Jaeger Luc , Calkins Erin R.
Published: September 2011

The concepts of functional equivalence classes and information control in living systems are useful to characterize downward (or top-down) causation by feedback information control in synthetic biology. Herein, we re-analyse published experiments of microbiology and synthetic biology that demonstrate the existence of several classes of functional equivalence in microbial organisms. Classes of functional equivalence from the bacterial operating system, which processes and controls the information encoded in the genome, can readily be interpreted as strong evidence, if not demonstration, of top-down causation (TDC) by information control. The proposed biological framework reveals how this type of causality is put in action in the cellular operating system. Considerations on TDC by information control and adaptive selection can be useful for synthetic biology by delineating the irreducible set of properties that characterizes living systems. Through a ‘retro-synthetic’ biology approach, these considerations could contribute to identifying the constraints behind the emergence of molecular complexity during the evolution of an ancient RNA/peptide world into a modern DNA/RNA/protein world. In conclusion, we propose TDCs by information control and adaptive selection as the two types of downward causality absolutely necessary for life.
PrcR, a PucR-type transcriptional activator, is essential for proline utilization and mediates proline-responsive expression of the proline utilization operon putBCP in Bacillus subtilis
Authors: Huang Shih-Chien , Lin Ta-Hui , Shaw Gwo-Chyuan
Published: September 2011

The soil bacteriumBacillus subtiliscan utilize exogenous proline as a sole nitrogen or carbon source. The proline-inducibleputBCP(formerlyycgMNO) operon encodes proteins responsible for proline uptake and two-step oxidation of proline to glutamate. We now report that a gene (formerlyycgP, now designatedprcR) located downstream of theputBCPoperon is essential forB. subtiliscells to utilize proline as a sole nitrogen or carbon source. Disruption of theprcRgene also abolished proline induction ofputBtranscription.prcRexpression is not subject to autoregulation and proline induction. The PrcR protein shows no significant amino acid sequence similarity to the known transcriptional activators for proline utilization genes of other bacteria, but it does show partial amino acid sequence similarity to the transcriptional regulator PucR for the purine degradation genes ofB. subtilis. PrcR orthologues of unknown function are present in some otherBacillusspecies. Primer-extension analysis suggests that bothputBandprcRare transcribed by a σA-dependent promoter. Deletion and mutation analysis revealed that an inverted repeat (5′-TTGTGG-N5-CCACAA-3′) centred at position −76 relative to the transcriptional initiation site ofputBis essential forputBexpression. Electrophoretic mobility shift assays showed that the purified His-tagged PrcR was capable of binding specifically to this inverted repeat. Altogether, these results suggest that PrcR is a PucR-type transcriptional activator that mediates expression of theB. subtilis putBCPoperon in response to proline availability.
Fatty acid composition of consumers in boreal lakes – variation across species, space and time
Authors: LAU DANNY C. P. , VREDE TOBIAS , PICKOVA JANA , GOEDKOOP WILLEM
Published: September 2011

1. Fatty acids (FAs) have been widely applied as trophic biomarkers in aquatic food web studies. However, current knowledge of inter‐ and intraspecific variation in consumer FA compositions across spatial and temporal scales is constrained to a few pelagic taxa.

2. We analysed the FAs of 22 taxa of benthic macroinvertebrates, zooplankton and fish collected from the littoral, pelagic and profundal habitats of nine boreal oligotrophic lakes over spring, summer and autumn. We quantified and compared the FA variance partitions contributed by species identity (i.e. an integrative effect of phylogenetic origin, life history and functional feeding guild of individual taxa), site and season using partial redundancy analysis both on all consumers and on benthic arthropods alone.

3. Species identity alone contributed 84.4 and 72.8% of explained FA variation of all consumers and benthic arthropods, respectively. Influences of site, season and all joint effects accounted for 0–11.3% only. Fatty acid profiles of primary consumers differentiated below class level, but those of predators were distinguishable only when they became more taxonomically distinct (i.e. among classes or higher).

4. Pelagic and profundal consumers showed stronger reliance on autochthonous resources than did their littoral counterparts as reflected by their higher ω3 to ω6 FA ratios. Polyunsaturated FAs (PUFAs) were increasingly retained with trophic levels, and saturated FAs (e.g. FA 16 : 0) gradually reduced. Ecologically, this trade‐off enhances the trophic transfer efficiency and confirms the importance of PUFA‐rich autotrophs in aquatic food webs.

5. Our findings indicate strong interspecific differences in FA requirements and assimilation among aquatic consumers from a wide range of taxonomic levels, habitats and lakes. Consumers were able to maintain homoeostasis in FA compositions across spatial and temporal changes in resource FAs, but consumer homoeostasis did not limit the effectiveness of FAs as trophic biomarkers.