bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring Fluoride Binding in DMSO: Why is a Singular Binding Behavior Observed?
Authors: Goursaud Matthieu , De Bernardin Paolo , Dalla Cort Antonella , Bartik Kristin , Bruylants Gilles
Published: May 2012

Fluoride recognition by molecular receptors is attracting much interest in the scientific community and a variety of approaches are used to achieve recognition with high affinity and selectivity. Most of the synthetic systems reported have been extensively studied in organic solvents by using tetrabutylammonium fluoride (TBAF) as the source of fluoride. In many cases, titration behaviors are observed that cannot be ascribed to a classical 1:1 binding isotherm. By using UV/Vis, 19F NMR, and 1H NMR spectroscopy we have been able to highlight that the equilibrium between the fluoride and the corresponding bihalide ion, HF2–, which is inevitably generated in situ due to trace amounts of water, can be at the origin of this singular behavior. Our results highlight that when undertaking titrations with fluoride in DMSO, the data can be affected by the fluoride–bihalide equilibrium and that the latter species can even be the dominating species at low TBAF concentrations.
Highlights of the Keystone Symposium: sirtuins in metabolism, aging and disease
Authors: Maxwell Michele M. , Zaldivar‐Jolissaint Julien Francisco , Mai Antonello , Outeiro Tiago F. , Kazanstev Aleksey G.
Published: May 2012

From February 12–16, 2012, leading members of the sirtuin scientific community assembled in Tahoe, CA to attend the Keystone Symposium “Sirtuins in Aging, Metabolism, and Disease.” It was a vibrant and lively meeting, and in the spirit of Keystone Symposia, both established sirtuin researchers and those new to the field enjoyed a unique opportunity to interact and exchange ideas.
Commercial Real‐Estate Inventory and Theory of Storage
Authors: Geman Helyette , Tunaru Radu
Published: May 2012

Real estate, like commodities, belongs to the category of alternative investments. Even though the characteristics of real estate are fairly different from those of crude oil or copper, inventory plays a crucial role in both cases. Our goal in this study is to investigate whether the theory of storage, as developed by Kaldor (1939) and Working (1949), then thoroughly analyzed for various commodities, can be extended to real estate. We take advantage of recent Futures data on the main U.K. commercial property index as well as a proprietary inventory database in order to test in this setting, and for the first time to our knowledge, the validity of the theory of storage for this asset class. The empirical evidence, covering data of the period 2008–2010, suggests that its main results can interestingly be extended to commercial real estate. © 2012 Wiley Periodicals, Inc. Jrl Fut Mark
Comprehensive expression profiling of microRNAs in laryngeal squamous cell carcinoma
Authors: Cao Pengyu , Zhou Liang , Zhang Jin , Zheng Fengyun , Wang Huijun , Ma Duan , Tian Jie
Published: May 2012

Background

MicroRNAs (miRNAs) are noncoding RNAs involved in posttranscriptional regulation of gene expression in cancer and provide new perspectives on the development of laryngeal squamous cell carcinoma (SCC).

Methods

miRNA expression of 6 pairs of laryngeal SCC and adjacent normal tissues was screened using miRNA array. Laser capture microdissection was applied to isolate a homogeneous group of cells from laryngeal SCC samples. The results of miRNA array analysis were validated in 48 pairs of laryngeal SCC and adjacent normal tissues using quantitative RT‐PCR.

Results

Twenty‐nine differentially expressed miRNAs were detected in the 6 pairs of laryngeal SCC, of which 6 were confirmed, including upregulation of miR‐21, miR‐93, miR‐205, and miR‐708 and downregulation of miR‐125b and miR‐145. Their putative target genes were predicted using 3 online software programs.

Conclusion

These differentially expressed miRNAs may play a role in tumorigenesis and progression in laryngeal SCC and offer new angles for further investigations into the function of miRNAs. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Occult metastases detected by sentinel node biopsy in patients with early oral and oropharyngeal squamous cell carcinomas: Impact on survival
Authors: Broglie Martina A. , Haerle Stephan K. , Huber Gerhard F. , Haile Sarah R. , Stoeckli Sandro J.
Published: May 2012

Background

Analysis of the lymphatic drainage pattern, the reliability of a negative sentinel lymph node biopsy (SLNB), as well as the impact of sentinel lymph node (SLN) metastases on regional control and survival in patients with early stage oral and oropharyngeal squamous cell carcinoma (SCC).

Methods

A prospective consecutive cohort analysis was conducted which included 111 patients diagnosed between 2003 and 2010. Endpoints of the study were neck control rate, overall survival (OS), disease‐specific survival (DSS), and disease‐free survival (DFS), depending on the size of occult metastases.

Results

Forty‐nine of 111 patients (38%) had positive SLNs, 10 had isolated tumor cells (ITCs), 19 had micrometastases, and 13 had macrometastases. OS, DSS, and DFS at 3 years for SLN‐negative and SLN‐positive patients was 98% and 71%, 95% and 76%, and 98% and 73%, respectively. Furthermore, there was a statistically significant difference between the SLN‐negative group and ITCs in DSS as well as between the SLN‐negative group and patients with micrometastases in OS and DSS and between the SLN‐negative group and patients with macrometastases in all 3 survival estimates.

Conclusion

Our study is the first to demonstrate that even small tumor deposits only detectable by the extensive histopathologic workup of the SLNB protocol have a significant impact on tumor control and survival in early Oropharyngeal SCC. Whether these findings will translate into different treatment strategies based on the upstaged neck has to be further investigated. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Liver sinusoidal endothelial cells contribute to CD8 T cell tolerance toward circulating carcinoembryonic antigen in mice
Authors: Höchst Bastian , Schildberg Frank A. , Böttcher Jan , Metzger Christina , Huss Sebastian , Türler Andreas , Overhaus Markus , Knoblich Andreas , Schneider Berthold , Pantelis Dimitrios , Kurts Christian , Kalff Jörg C. , Knolle Percy , Diehl Linda
Published: May 2012

Immunity against cancer is impeded by local mechanisms promoting development of tumor-specific T cell tolerance, such as regulatory T cells, myeloid-derived suppressor cells, or immunosuppressive factors in the tumor microenvironment. The release of soluble antigens, such as carcinoembryonic antigen (CEA) from colorectal carcinoma (CRC) cells, has been investigated for diagnostic purposes, but not for its immunological consequences. Here, we address the question of whether soluble CEA influences tumor-specific immunity. Mice were injected with soluble CEA protein, and CEA-specific CD8 T cells were analyzed for their phenotype and functionality by means of restimulation

ex vivo

or antitumor efficacy

in vivo

. We furthermore characterized the CD8 T cell population in peripheral blood mononuclear cell (PBMCs) from healthy donors and colorectal carcinoma patients. In mice, circulating CEA was preferentially taken up in a mannose receptor–dependent manner and cross-presented by liver sinusoidal endothelial cells, but not dendritic cells, to CD8 T cells. Such systemically circulating CEA promoted tolerization of CEA-specific CD8 T cells in the endogenous T cell repertoire through the coinhibitory molecule B7H1. These CD8 T cells were not deleted but were rendered nonresponsive to antigen-specific stimulation and failed to control growth of CEA-expressing tumor cells. These nonresponsive CD8 T cells were phenotypically similar to central memory T cells being CD44highCD62LhighCD25neg. We found T cells with a similar phenotype in PBMCs of healthy donors and at increased frequency also in patients with colorectal carcinoma.

Conclusion:

Our results provide evidence for the existence of an unrecognized tumor immune escape involving cross-presentation of systemically circulating tumor antigens that may influence immunotherapy of cancer.
Vitamin D binding protein gene polymorphisms and baseline vitamin D levels as predictors of antiviral response in chronic hepatitis C
Authors: Falleti Edmondo , Bitetto Davide , Fabris Carlo , Fattovich Giovanna , Cussigh Annarosa , Cmet Sara , Ceriani Elisa , Fornasiere Ezio , Pasino Michela , Ieluzzi Donatella , Pirisi Mario , Toniutto Pierluigi
Published: May 2012

Vitamin D deficiency seems to predict the unsuccessful achievement of sustained viral response (SVR) after antiviral treatment in hepatitis C virus (HCV) difficult-to-treat genotypes. Vitamin D binding protein (GC) gene polymorphisms are known to influence vitamin D levels. This study was performed to assess whether the interaction between basal circulating vitamin D and the GC polymorphism plays a role in influencing the rate of antiviral responses in patients affected by chronic hepatitis C. In all, 206 HCV patients treated with a combination therapy of pegylated (PEG)-interferon plus ribavirin were retrospectively evaluated. GC rs7041 G>T, GC rs4588 C>A, and IL-28B rs12979860 C>T polymorphisms were genotyped. Frequencies of GC rs7041 G>T and rs4588 C>A polymorphisms were: G/G = 64 (31.1%), G/T = 100 (48.5%), T/T = 42 (20.4%) and C/C = 108 (52.4%), C/A = 84 (40.8%), A/A = 14 (6.8%). Patients were divided into those carrying ≥3 major alleles (wildtype [WT]+: G-C/G-C, G-C/T-C, G-C/G-A, N = 100) and the remaining (WT−: G-C/T-A, T-A/T-C, T-A/T-A, T-C/T-C, N = 106). Four groups were identified: vitamin D ≤20 ng/mL and WT−, vitamin D ≤20 and WT+, vitamin D >20 and WT−, vitamin D >20 and WT+. In difficult-to-treat HCV genotypes the proportion of patients achieving SVR significantly increased with a linear trend from the first to the last group: 6/25 (24.0%), 9/24 (37.5%), 12/29 (41.4%), 19/29 (65.5%) (

P

= 0.003). At multivariate analysis, having basal vitamin D >20 ng/mL plus the carriage of GC WT+ was found to be an independent predictor of SVR (odds ratio 4.52,

P

= 0.015).

Conclusion :

In difficult-to-treat HCV genotypes, simultaneous pretreatment normal serum vitamin D levels and the carriage of GC-globulin WT isoform strongly predicts the achievement of SVR after PEG-interferon plus ribavirin antiviral therapy.
Topographic analysis for the prairie pothole region of Western Canada
Authors: Shaw Dean A. , Pietroniro Al , Martz L.W.
Published: May 2012

The unique topography of the pothole region of the North American prairies creates challenges for properly determining basin contributing area. Numerous depressions or potholes within the landscape impound runoff. However, potholes can ‘fill‐spill’ resulting in surface water connections between the potholes. Surface water connectivity between potholes ultimately influences basin contributing area. Currently, automated methods, such as landscape analysis tools, treat depressions in the landscape as artifacts and simply fill the depressions to delineate a drainage basin. Using this method to calculate contributing area assumes that all surface storage has been satisfied (threshold) and the drainage basin will contribute 100% of its area for all runoff events. However, most runoff events in the prairie pothole region are pre‐threshold events that contribute only a portion of surface runoff to the outlet. These pre‐threshold events have surface storage that varies because of antecedent water levels and have a variable or dynamic potential to store further runoff in the basin. Government agencies have developed methodologies for determining pre‐threshold contributing areas, but these methodologies do not incorporate current technologies and, as a result, have limitations.

We propose an automated method for determining contributing area that incorporates the fill‐spill of prairie potholes. The algorithm, which uses the D‐8 drainage direction method, automates a methodology for identifying and quantifying runoff contributing area. Any algorithm that determines pre‐threshold contributing area, must allow the DEM to be filled in an incremental manner. This will simulate increasing pond levels, and the resulting decrease in available storage in the basin, in response to runoff events. The SPILL algorithm is an iterative solution that increases the magnitude of input runoff events and records the decreasing change in available surface storage and the increase in contributing area until the storage threshold is reached and the contributing area reaches 100%. Through application of the algorithm on prairie pothole region basins, we test proposed conceptual curves that describe a hypothesized non‐linear relationship between decreasing potential storage in the landscape and contributing area. Results indicate that the proposed conceptual curves represent the relationship between potential surface storage and contributing area in the test basins very well. Copyright © 2012 John Wiley & Sons, Ltd.
Inverse modelling for freshwater lens in small islands: Kish Island, Persian Gulf
Authors: Ataie‐Ashtiani Behzad , Rajabi Mohammad Mahdi , Ketabchi Hamed
Published: May 2012

A number of challenges including instability, nonconvergence, nonuniqueness, nonoptimality, and lack of a general guideline for inverse modelling have limited the application of automatic calibration by generic inversion codes in solving the saltwater intrusion problem in real‐world cases. A systematic parameter selection procedure for the selection of a small number of independent parameters is applied to a real case of saltwater intrusion in a small island aquifer system in the semiarid region of the Persian Gulf. The methodology aims at reducing parameter nonuniqueness and uncertainty and the time spent on inverse modelling computations. Subsequent to the automatic calibration of the numerical model, uncertainty is analysed by constrained nonlinear optimization of the inverse model. The results define the percentage of uncertainty in the parameter estimation that will maintain the model inside a user‐defined neighbourhood of the best possible calibrated model. Sensitivity maps of both pressure and concentration for the small island aquifer system are also developed. These sensitivity maps indicate higher sensitivity of pressure to model parameters compared with concentration. These sensitivity maps serve as a benchmark for correlation analysis and also assist in the selection of observations points of pressure and concentration in the calibration process. Copyright © 2012 John Wiley & Sons, Ltd.
Greater effect of canopy conductance in regulating the energy partition above the maize field in arid northwest China
Authors: Li Sien , Kang Shaozhong , Zhang Lu , Li Fusheng , Du Taisheng , Tong Ling , Wang Shufen , Lu Hongna
Published: May 2012

The partition of available energy into evapotranspiration affected by environmental and physiological factors is critical in understanding the water cycle and optimizing the water management in the field. Our study attempted to accurately quantify the environmental and physiological control on variability in evaporative fraction (EF) based on the Penman–Monteith model. The eddy covariance method was used to measure water flux over a canopy and then calculate the EF above a maize field in northwest China in 2007. Results indicate that the EF was lower in other growth stages than in the heading stage, so the EF value in the heading stage was taken as the standard value. The decreases in EF caused by canopy conductance and environmental factors were 0.176 and −0.026, accounting for 117% and −17% of the total difference in EF, respectively. Such results were mainly due to the following: (1) the variation of maize canopy conductance was greater than that of the environmental factors, such as air temperature, air humidity, wind speed and radiation; (2) the EF of the maize was more sensitive to variation in canopy conductance than the environmental factor. Our study revealed that crop physiological factor played an important role in determining the energy partition processes and reducing the sensible heat flux in the maize field. Copyright © 2012 John Wiley & Sons, Ltd.
Sequential chemoradiotherapy with gemcitabine and cisplatin for locoregionally advanced nasopharyngeal carcinoma
Authors: Gu Mo‐Fa , Liu Li‐Zhi , He Long‐Jun , Yuan Wen‐Xin , Zhang Rong , Luo Guang‐Yu , Xu Guo‐Liang , Zhang Hua‐Man , Yan Chao‐Xian , Li Jian‐Jun
Published: May 2012

We investigated a new chemoradiotherapy (CRT) regimen for locoregionally advanced nasopharyngeal carcinoma (NPC). A total of 240 patients were randomly assigned to three different CRT regimens: sequential CRT [1 cycle chemotherapy + Phase I radiotherapy (RT) + 1 cycle chemotherapy + Phase II RT + 2 cycles chemotherapy] with a cisplatin–gemcitabine (GC) regimen (800 mg/m2 gemcitabine on Days 1 and 8 and 20 mg/m2 cisplatin on Days 1–5, every 4 weeks) (sGC‐RT); sequential chemoradiotherapy with a cisplatin–fluorouracil (PF) regimen (20 mg/m2 DDP and 500 mg/m2 5‐FU on Days 1–5, every 4 weeks) (sPF‐RT) and cisplatin‐based concurrent chemoradiotherapy plus adjuvant PF chemotherapy (Con‐RT + PF). The complete response rate was higher in the sGC + RT group than in the other two groups (98.75% vs. 92.50%, p < 0.01). The 3‐year overall survival (OS), disease‐free survival (DFS) and distant metastasis‐free survival (DMFS) rates in the sGC‐RT group were significantly higher than those observed in the Con‐RT group (OS, 95.0% vs. 76.3%, p < 0.001; DFS, 89.9% vs. 67.5%, p < 0.001; DMFS, 92.5% vs. 76.0%, p = 0.004) and in the sPF + RT group (OS, 95.0% vs. 73.6%, p < 0.001; DFS, 89.9% vs. 63.3%, p < 0.001; DMFS, 92.5% vs. 74.7%, p = 0.002). There were no significant differences in 3‐year OS, DFS and MFS rates between the Con‐RT and the sPF‐RT groups. The GC‐RT group experienced more hematologic toxicity, constipation and rash; however, there were no differences in late RT toxicity between the groups. These results demonstrate that a sGC‐RT regimen is effective and well tolerated in patients with locoregionally advanced NPC.
Ribonucleases P/MRP and the Expanding Ribonucleoprotein World
Authors: Hernandez‐Cid Aaron , Aguirre‐Sampieri Sergio , Diaz‐Vilchis Adelaida , Torres‐Larios Alfredo
Published: May 2012

One of the hallmarks of life is the widespread use of certain essential ribozymes. The ubiquitous ribonuclease P (RNase P) and eukaryotic RNase MRP are essential complexes where a structured, noncoding RNA acts in catalysis. Recent discoveries have elucidated the three‐dimensional structure of the ancestral ribonucleoprotein complex, suggested the possibility of a protein‐only composition in organelles, and even noted the absence of RNase P in a non‐free‐living organism. With respect to these last two findings, import mechanisms for RNases P/MRP into mitochondria have been demonstrated, and RNase P is present in organisms with some of the smallest known genomes. Together, these results have led to an ongoing debate regarding the precise definition of how “essential” these ribozymes truly are. © IUBMB IUBMB Life, 2012.
Acceptance as a process variable in relation to catastrophizing in multidisciplinary pain treatment
Authors: Baranoff J. , Hanrahan S.J. , Kapur D. , Connor J.P.
Published: May 2012

Background

The underlying processes of change that contribute to the effectiveness of multidisciplinary pain treatment require clarification. Previous research has found support for pain acceptance as a process variable in acceptance‐based treatment. Preliminary findings indicate that pain acceptance may also be a process variable in traditional cognitive behavioural therapy (CBT). The aim of this study was to investigate the role of pain acceptance as a process variable in CBT relative to two empirically supported process variables, namely catastrophizing and pain intensity.

Methods

Patients with chronic pain (n = 186) attended a 3‐week, multidisciplinary pain programme, which was CBT based. Patients completed a measure of pain intensity; the Chronic Pain Acceptance Questionnaire; the catastrophizing subscale of the Pain Response Self‐Statements Scale; the Roland Morris Disability Questionnaire; the Depression Anxiety and Stress Scale; and two measures of physical functioning at pretreatment, post‐treatment and 3‐month follow‐up.

Results

Both acceptance and catastrophizing showed statistically significant and clinically relevant changes from pre‐ to post‐treatment. Changes in both acceptance and catastrophizing showed a significant correlation with changes in almost all of the outcome variables. Regression analyses demonstrated that change in acceptance was a significant predictor of changes in depression, disability, timed walk and sit‐to‐stand performance, after controlling for changes in catastrophizing and pain intensity.

Conclusions

Although not specifically targeted in CBT treatment, acceptance of pain was an important process variable that contributed to CBT treatment outcomes after controlling for changes in pain intensity and catastrophizing. Implications for future research and clinical practice are discussed.
Built to Bite: Feeding Kinematics, Bite Forces, and Head Shape of a SpecializedDurophagous Lizard,Dracaena Guianensis(Teiidae)
Authors: SCHAERLAEKEN VICKY , HOLANOVA VERONIKA , BOISTEL R. , AERTS PETER , VELENSKY PETR , REHAK IVAN , ANDRADE DENIS V. , HERREL ANTHONY
Published: May 2012

Most lizards feed on a variety of food items that may differ dramatically in their physical and behavioral characteristics. Several lizard families are known to feed upon hard‐shelled prey (durophagy). Yet, specializations toward true molluscivory have been documented for only a few species. As snails are hard and brittle food items, it has been suggested that a specialized cranial morphology, high bite forces, and an adapted feeding strategy are important for such lizards. Here we compare head and skull morphology, bite forces, and feeding kinematics of a snail‐crushing teiid lizard (Dracaena guianensis) with those in a closely related omnivorous species (Tupinambis merianae). Our data show that juvenileD. guianensisdiffer fromT. merianaein having bigger heads and greater bite forces. Adults, however, do not differ in bite force. A comparison of feeding kinematics in adultDracaenaandTupinambisrevealed thatDracaenatypically use more transport cycles, yet are more agile in manipulating snails. During transport, the tongue plays an important role in manipulating and expelling shell fragments before swallowing. AlthoughDracaenais slow, these animals are very effective in crushing and processing hard‐shelled prey.J. Exp. Zool. 317A:371–381, 2012. © 2012 Wiley Periodicals, Inc.
Acyclic List Edge Coloring of Graphs
Authors: Lai Hsin-Hao , Lih Ko-Wei
Published: May 2012

A proper edge coloring of a graph is said to be acyclic if any cycle is colored with at least three colors. An edge-list L of a graph G is a mapping that assigns a finite set of positive integers to each edge of G. An acyclic edge coloring ϕ of G such that for any is called an acyclic L-edge coloring of G. A graph G is said to be acyclically k-edge choosable if it has an acyclic L‐edge coloring for any edge‐list L that satisfies for each edge e. The acyclic list chromatic index is the least integer k such that G is acyclically k‐edge choosable. We develop techniques to obtain bounds for the acyclic list chromatic indices of outerplanar graphs, subcubic graphs, and subdivisions of Halin graphs.
On Forbidden Pairs Implying Hamilton‐Connectedness
Authors: Faudree Jill R. , Faudree Ralph J. , Ryjáček Zdeněk , Vrána Petr
Published: May 2012

Let X, Y be connected graphs. A graph G is ‐free if G contains a copy of neither X nor Y as an induced subgraph. Pairs of connected graphs such that every 3‐connected ‐free graph is Hamilton connected have been investigated most recently in (Guantao Chen and Ronald J. Gould, Bull. Inst. Combin. Appl., 29 (2000), 25–32.) [8] and (H. Broersma, R. J. Faudree, A. Huck, H. Trommel, and H. J. Veldman, J. Graph Theory, 40(2) (2002), 104–119.) [5]. This paper improves those results. Specifically, it is shown that every 3‐connected ‐free graph is Hamilton connected for and or N1, 2, 2 and the proof of this result uses a new closure technique developed by the third and fourth authors. A discussion of restrictions on the nature of the graph Y is also included.
FINANCIAL SECTOR DEVELOPMENT AND INEQUALITY: IS THERE A FINANCIAL KUZNETS CURVE?
Authors: Nikoloski Zlatko
Published: May 2012

The existing empirical knowledge in the area of financial sector development and income inequality finds evidence for the theoretical work which posits a simple, linear relationship between the two variables. In this article, we subject the extant empirical knowledge to close scrutiny and point out to a potential dynamic and endogenous relationship between financial sector development and inequality. By using dynamic multivariate panel data analysis on a carefully selected data set of income inequality data for developed and developing countries spanning the period 1962–2006, we find robust empirical evidence for the existence of an inverted U‐curve relationship between financial sector development and income inequality. In that token, we confirm the theoretical stipulations of Greenwood and Jovanovic (1990) for an inverted U‐curve relationship between the financial sector and income inequality. Copyright © 2012 John Wiley & Sons, Ltd.
An empirical analysis of surface acting in intra‐organizational relationships
Authors: Ozcelik Hakan
Published: May 2012

Prior research analyzing surface acting—employees' regulation of emotional expressions—has mostly focused on the interactions between front‐line employees and their customers in service industries and paid very little attention to intra‐organizational relationships. With an aim to shed light on this important yet relatively unexplored area, I developed a theoretical model analyzing the antecedents and outcomes of surface acting within organizations, by drawing on the sociometer theory and self‐presentation theory frameworks.

To test the model, I conducted a cross‐level field study in a sample of 65 work groups and 478 employees in two organizations, located in a large city in Northern California. I have collected the data from two sources, including employees and their supervisors who rated their performance. Results indicated that employees were more likely to engage in surface acting when their affective traits and personal goals were less congruent with work environment. Surface acting was also positively related to perceived organizational politics and self‐monitoring. As for outcomes, surface acting was positively related to emotional exhaustion and negatively to performance. I discuss limitations, implications, and future research direction. Copyright © 2012 John Wiley & Sons, Ltd.
High‐performer turnover and firm performance: The moderating role of human capital investment and firm reputation
Authors: Kwon Kiwook , Rupp Deborah E.
Published: May 2012

Research has shown a complex relationship between turnover and firm performance. Not only does it matter who leaves (e.g., high‐performing versus low‐performing employees), but the context also stands to influence this effect in complex ways. We apply human capital theory, social capital theory, and the cost–benefit perspective to propose two boundary conditions to the high‐performer turnover and firm performance relationship. Specifically, we predict that the negative impact of high‐performer turnover on firm performance will be the strongest for reputable firms and for firms who invest less in human capital (e.g., selection, training, and incentive‐based pay). We present data from 155 South Korean firms that support the hypothesized model. We discuss findings in terms of current and future theory, practical implications, and subsequent research needs. Copyright © 2012 John Wiley & Sons, Ltd.
Two‐week joint mobilization intervention improves self‐reported function, range of motion, and dynamic balance in those with chronic ankle instability
Authors: Hoch Matthew C. , Andreatta Richard D. , Mullineaux David R. , English Robert A. , Medina McKeon Jennifer M. , Mattacola Carl G. , McKeon Patrick O.
Published: May 2012

We examined the effect of a 2‐week anterior‐to‐posterior ankle joint mobilization intervention on weight‐bearing dorsiflexion range of motion (ROM), dynamic balance, and self‐reported function in subjects with chronic ankle instability (CAI). In this prospective cohort study, subjects received six Maitland Grade III anterior‐to‐posterior joint mobilization treatments over 2 weeks. Weight‐bearing dorsiflexion ROM, the anterior, posteromedial, and posterolateral reach directions of the Star Excursion Balance Test (SEBT), and self‐reported function on the Foot and Ankle Ability Measure (FAAM) were assessed 1 week before the intervention (baseline), prior to the first treatment (pre‐intervention), 24–48 h following the final treatment (post‐intervention), and 1 week later (1‐week follow‐up) in 12 adults (6 males and 6 females) with CAI. The results indicate that dorsiflexion ROM, reach distance in all directions of the SEBT, and the FAAM improved (p < 0.05 for all) in all measures following the intervention compared to those prior to the intervention. No differences were observed in any assessments between the baseline and pre‐intervention measures or between the post‐intervention and 1‐week follow‐up measures (p > 0.05). These results indicate that the joint mobilization intervention that targeted posterior talar glide was able to improve measures of function in adults with CAI for at least 1 week. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1798–1804, 2012
Central England temperature since AD 1850: the potential of stable carbon isotopes in British oak trees to reconstruct past summer temperatures
Authors: Young G. H. F. , Bale R. J. , Loader N. J. , Mccarroll D. , Nayling N. , Vousden N.
Published: May 2012

In regions with seasonal temperate climatic regimes, tree growth is rarely controlled by any single environmental factor. As a consequence, the development of robust palaeoclimate reconstructions has proved challenging. Tree‐ring stable carbon isotope ratios (δ13C), however, are controlled primarily by photosynthetic rate, not by net growth. Therefore, at sites where climatic controls on tree‐ring growth are not strongly expressed, a robust (isotopic) palaeoclimate signal may still potentially be preserved. This hypothesis was tested using a 160‐year record of δ13C measured from the pooled latewood cellulose of six Quercus petraea L. (sessile oak) trees from Allt Lan‐las in West Wales, UK. Raw δ13C values were corrected for changes in the isotopic ratio of atmospheric carbon dioxide and for changes in the behaviour of trees due to the increasing availability of atmospheric CO2 since AD 1850. Strong correlations with local summer temperature and sunshine are reported, and also with the Central England Temperature record over the full length of the isotopic chronology (AD 1850–2010) (r = 0.69, P < 0.001). We conclude that tree‐ring stable isotopes can be used to extract strong palaeoclimate signals even from oak trees growing in a temperate maritime climate. This demonstrates the potential for extracting robust palaeoclimatic information from the very long and well‐replicated oak chronologies which have been developed in western and central Europe primarily for dating rather than palaeoclimatic research purposes. Copyright © 2012 John Wiley & Sons, Ltd.
Tailored Poly(2‐oxazoline) Polymer Brushes to Control Protein Adsorption and Cell Adhesion
Authors: Zhang Ning , Pompe Tilo , Amin Ihsan , Luxenhofer Robert , Werner Carsten , Jordan Rainer
Published: May 2012

POx bottle‐brush brushes (BBBs) are synthesized by SIPGP of 2‐isopropenyl‐2‐oxazoline and consecutive LCROP of 2‐oxazolines on 3‐aminopropyltrimethoxysilane‐modified silicon substrates. The side chain hydrophilicity and polarity are varied. The impact of the chemical composition and architecture of the BBB upon protein (fibronectin) adsorption and endothelial cell adhesion are investigated and prove extremely low protein adsorption and cell adhesion on BBBs with hydrophilic side chains such as poly(2‐methyl‐2‐oxazoline) and poly(2‐ethyl‐2‐oxazoline). The influence of the POx side chain terminal function upon adsorption and adhesion is minor but the side chain length has a significant effect on bioadsorption.

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Aqueous‐Phase Copolymerization of N‐Vinylpyrrolidone and N‐Vinylformamide
Authors: Santanakrishnan Sandhya , Stach Marek , Lacík Igor , Hutchinson Robin A.
Published: May 2012

Aqueous‐phase batch free‐radical copolymerization of NVP and NVF is studied at 60 and 85 °C with varying initial monomer mixture compositions and monomer to water ratios. The rate of monomer conversion is found to increase with increasing NVP molar fraction and with decreasing total monomer concentration, in accordance with the expected behavior based on homopolymerization kinetics. The copolymer composition is equal to the initial comonomer composition, indicating monomer reactivity ratios to be unity. A terminal copolymerization model provides a good description of polymerization rate, copolymer composition, and polymer molar mass distributions using the same kinetic rate coefficients as used to previously describe the homopolymerization of the two monomers.
Dispersion of Single‐Walled Carbon Nanotubes with Poly(Pyridinium Salt)s Containing Various Rigid Aromatic Moieties
Authors: Jo Tae Soo , Han Haesook , Bhowmik Pradip K. , Ma Longzhou
Published: May 2012

Dispersions of single‐walled carbon nanotubes (SWNTs) with several poly(pyridinium salt)s containing various aromatic diamine moieties are prepared via a non‐covalent coagulation in DMSO. The interactions between SWNTs and polymers are characterized with various spectroscopic techniques. The 1H NMR spectra suggest that strong interactions exist. The UV−Vis absorption spectra are independent of the incorporation of SWNTs. The resulting composites display high quenching efficiency in the photoluminescent properties; and transmission electron microscopy studies reveal the well‐dispersed SWNTs in the ionic polymer matrices. The enhanced thermal stability of the composites is determined by thermogravimetric analysis. The fully grown lyotropic LC properties of the poly(pyridinium salt)s are disrupted by the introduction of SWNTs.
Differentially Degradable Janus Particles for Controlled Release Applications
Authors: Hwang Sangyeul , Lahann Joerg
Published: May 2012

Janus particles with differentially degradable compartments were prepared by electrohydrodynamic (EHD) co‐jetting and subsequent controlled crosslinking. These bicompartmental particles are composed of an interpenetrating polymer network of poly(ethylene oxide) and poly(acrylamide‐co‐acrylic acid) in one hemisphere and a crosslinked copolymer of dextran and poly(acrylamide‐co‐acrylic acid) segments in the second compartment. The compositional anisotropy caused differential hydrolytic susceptibility: Although both compartments were stable at pH 3.0, selective degradation of the PEO‐containing compartment pH 7.4 was observed wtihin 5 days. Janus particles with differentially degradable polymer compartments may be of interest for a range of oral drug delivery applications because of their propensity for decoupled release profiles.
Zinc Undecylenate Catalyst for the Ring‐Opening Polymerization of Caprolactone Monomers
Authors: Hao Jing , Granowski Patricia C. , Stefan Mihaela C.
Published: May 2012

The ring‐opening polymerization of two caprolactone monomers catalyzed by zinc undecylenate (ZU) is reported. Polymerizations were performed in bulk with benzyl alcohol (BnOH) as an initiator at 90 and 110 °C, respectively. A slower polymerization rate was observed for γ‐octyloxy‐ϵ‐caprolactone as compared to ϵ‐caprolactone. Diblock copolymers were synthesized by the sequential monomer addition at 90 and 110 °C. The kinetic studies performed for the ring‐opening polymerization of ϵ‐caprolactone and γ‐octyloxy‐ϵ‐caprolactone and the successful synthesis of diblock copolymers by the sequential monomer addition confirmed the controlled/living nature of zinc undecylenate catalyzed reactions.
Molecular Nanoworm with PCL Core and PEO Shell as a Non‐spherical Carrier for Drug Delivery
Authors: Zhao Peng , Liu Lixin , Feng Xiaoqin , Wang Chun , Shuai Xintao , Chen Yongming
Published: May 2012

Core/shell wormlike polymer brushes with densely grafted poly(ϵ‐caprolactone)‐b‐poly(ethylene oxide) (PCL‐b‐PEO) are synthesized via grafting an alkynyl terminated PCL‐b‐PEO (ay‐PCL17‐b‐PEO113) onto a well‐defined azido functionalized polymethacrylate (PGA940) and are evaluated preliminarily as a single molecular cylindrical vehicle for drug delivery. Water soluble molecular worms of ca. 230 nm are obtained and then the anticancer drug doxorubicin (DOX) is loaded into its PCL core by hydrophobic interaction. Compared with spherical micelles from linear PCL17‐b‐PEO113, the brushes demonstrate a lower loading efficiency but a faster release rate of DOX. Confocal laser scanning microscopy measurements show that DOX‐loaded cylindrical molecular brushes can easily enter into HeLa and HepG2 cells in 1 h.
Efficient Polymerization of Azide and Active Internal Alkynes
Authors: Wei Qiang , Deng Haiqin , Cai Yunbo , Lam Jacky W. Y. , Li Jie , Sun Jingzhi , Gao Meng , Qin Anjun , Tang Ben Zhong
Published: May 2012

The 1,3‐dipolar cycloaddition of azides and active internal alkynes has been well studied, but is rarely utilized as a tool for polymer preparation. In this work, an efficient polymerization route is developed. Polycycloaddition of diazide (4) and bis(benzoylethynyl)‐benzenes and ‐butane (3) at elevated temperature has produced the first examples of soluble 1,4,5‐trisubstituted polytriazoles PI with satisfactory molecular weights (Mw up to 16 400) in excellent yields (up to 98.6%). All the obtained polymers are thermally stable, losing merely 5% of their weights at temperatures higher than 367 °C. They exhibit higher refractive indices than some commercial plastics and can be crosslinked upon UV irradiation to generate a 3D photopattern with high resolution. The metal‐free feature of such a methodology offers a facile tool to prepare functional materials free from the contamination of metal species.
Gene expression of peripheral blood mononuclear cells as a tool in dietary intervention studies: What do we know so far?
Authors: de Mello Vanessa Derenji Ferreira , Kolehmanien Marjukka , Schwab Ursula , Pulkkinen Leena , Uusitupa Matti
Published: May 2012

Peripheral blood mononuclear cells (PBMCs) generally refer to monocytes and lymphocytes, representing cells of the innate and adaptive immune systems. PBMCs are a promising target tissue in the field of nutrigenomics because they seem to reflect the effects of dietary modifications at the level of gene expression. In this review, we describe and discuss the scientific literature concerning the use of gene expression at the mRNA level measured from PBMCs in dietary interventions studies conducted in humans. A search of literature was undertaken using PubMed (last assessed November 24, 2011) and 20 articles were selected for discussion. Currently, results from these studies showed that PBMCs seem to reflect liver environment and complement adipose tissue findings in transcriptomics. PBMC gene expression after dietary intervention studies can be used for studying the response of certain genes related to fatty acid and cholesterol metabolism, and to explore the response of dietary interventions in relation to inflammation. However, PBMC transcriptomics from dietary intervention studies have not resulted yet in clear confirmation of candidate genes related to disease risk. Use of microarray technology in larger well‐designed dietary intervention studies is still needed for exploring PBMC potential in the field of nutrigenomics.
Prevalence, incidence and determinants of PTSD and other mental disorders: design and methods of the PID‐PTSD+3 study
Authors: Wittchen Hans‐Ulrich , Schönfeld Sabine , Thurau Christin , Trautmann Sebastian , Galle Michaela , Mark Kathleen , Hauffa Robin , Zimmermann Peter , Schaefer Judith , Steudte Susann , Siegert Jens , Höfler Michael , Kirschbaum Clemens
Published: May 2012

Investigation of the prevalence, incidence, and determinants of post‐traumatic stress disorders (PTSD) and other mental disorders associated with military deployment in international missions poses several methodological and procedural challenges. This paper describes the design and sampling strategies, instruments, and experimental procedures applied in a study programme aimed to examine military deployment‐related mental health and disorders (prevalence and trajectories) and to identify vulnerability and risk factors (e.g. age, gender, type of mission, rank, and duration of deployment and a wide range of neurobiological, psychological, social, and behavioural factors).

The study comprised two components. The first component, a cross‐sectional study, included 1483 deployed and 889 non‐deployed German soldiers (response rate, 93%) who served during the 2009 International Security Assistance Force (ISAF) mission. A standardized diagnostic instrument (Composite International Diagnostic Interview, CIDI) coupled with established questionnaires was administered to detect and diagnose PTSD and a broad spectrum of mental disorders and mental health problems. The second component, a prospective‐longitudinal study, included 621 soldiers examined before (2011) and after return (2012) from the ISAF mission. In addition to the CIDI and questionnaires, several experimental behavioural tests and biological markers were implemented to probe for incident mental disorders, mental health problems and risk factors. Our methods are expected to provide greater precision than previous studies for estimating the risk for incident deployment‐related and non‐deployment‐related disorders and their risk factors. We expect the findings to advance our understanding of a wide spectrum of adverse mental health outcomes beyond PTSD. Copyright © 2012 John Wiley & Sons, Ltd.
SAR simulations for high‐field MRI: How much detail, effort, and accuracy is needed?
Authors: Wolf S. , Diehl D. , Gebhardt M. , Mallow J. , Speck O.
Published: May 2012

Accurate prediction of specific absorption rate (SAR) for high field MRI is necessary to best exploit its potential and guarantee safe operation. To reduce the effort (time, complexity) of SAR simulations while maintaining robust results, the minimum requirements for the creation (segmentation, labeling) of human models and methods to reduce the time for SAR calculations for 7 Tesla MR‐imaging are evaluated. The geometric extent of the model required for realistic head‐simulations and the number of tissue types sufficient to form a reliable but simplified model of the human body are studied. Two models (male and female) of the virtual family are analyzed. Additionally, their position within the head‐coil is taken into account. Furthermore, the effects of retuning the coils to different load conditions and the influence of a large bore radiofrequency‐shield have been examined. The calculation time for SAR simulations in the head can be reduced by 50% without significant error for smaller model extent and simplified tissue structure outside the coil. Likewise, the model generation can be accelerated by reducing the number of tissue types. Local SAR can vary up to 14% due to position alone. This must be considered and sets a limit for SAR prediction accuracy. All these results are comparable between the two body models tested. Magn Reson Med 69:1157–1168, 2013. © 2012 Wiley Periodicals, Inc.
A Dissipation Gap Method for full‐field measurement‐based identification of elasto‐plastic material parameters
Authors: Blaysat B. , Florentin E. , Lubineau G. , Moussawi A.
Published: May 2012

Using enriched data such as displacement fields obtained from digital image correlation is a pathway to the local identification of material parameters. Up to now, most of the identification techniques for nonlinear models are based on Finite Element Updating Methods. This article explains how an appropriate use of the Dissipation Gap Method can help in this context and be an interesting alternative to these classical techniques. The Dissipation Gap Methods rely on the concept of error in dissipation that has been used mainly for the verification of finite element simulations. We provide here an original application of these founding developments to the identification of material parameters for nonlinear behaviors. The proposed technique and especially the main technical keypoint of building the admissible fields are described in detail. The approach is then illustrated through the identification of heterogeneous isotropic elasto‐plastic properties. The basic numerical features highlighted through these simple examples demonstrate this approach to be a promising tool for nonlinear identification.Copyright © 2012 John Wiley & Sons, Ltd.
A multiscale finite element method for modeling fully coupled thermomechanical problems in solids
Authors: Sengupta Arkaprabha , Papadopoulos Panayiotis , Taylor Robert L.
Published: May 2012

This article proposes a two‐scale formulation of fully coupled continuum thermomechanics using the finite element method at both scales. A monolithic approach is adopted in the solution of the momentum and energy equations. An efficient implementation of the resulting algorithm is derived that is suitable for multicore processing. The proposed method is applied with success to a strongly coupled problem involving shape‐memory alloys.Copyright © 2012 John Wiley & Sons, Ltd.
Differential drug class‐specific metastatic effects following treatment with a panel of angiogenesis inhibitors
Authors: Chung Alicia S , Kowanetz Marcin , Wu Xiumin , Zhuang Guanglei , Ngu Hai , Finkle David , Komuves Laszlo , Peale Franklin , Ferrara Napoleone
Published: May 2012

Inhibiting angiogenesis has become an important therapeutic strategy for cancer treatment but, like other current targeted therapies, benefits experienced for late‐stage cancers can be curtailed by inherent refractoriness or by acquired drug resistance, requiring a need for better mechanistic understanding of such effects. Numerous preclinical studies have demonstrated that VEGF pathway inhibitors suppress primary tumour growth and metastasis. However, it has been recently reported that short‐term VEGF and VEGFR inhibition can paradoxically accelerate tumour invasiveness and metastasis in certain models. Here we comprehensively compare the effects of both antibody and small molecule receptor tyrosine kinase (RTK) inhibitors targeting the VEGF–VEGFR pathway, using short‐term therapy in various mouse models of metastasis. Our findings demonstrate that antibody inhibition of VEGF pathway molecules does not promote metastasis, in contrast to selected small molecule RTK inhibitors at elevated‐therapeutic drug dosages. In particular, a multi‐targeted RTK inhibitor, sunitinib, which most profoundly potentiated metastasis, also increased lung vascular permeability and promoted tumour cell extravasation. Mechanistically, sunitinib, but not anti‐VEGF treatment, attenuated endothelial barrier function in culture and caused a global inhibition of protein tyrosine phosphorylation, including molecules important for maintaining endothelial cell–cell junctions. Together these findings indicate that, rather than a specific consequence of inhibiting the VEGF signalling pathway, pharmacological inhibitors of the VEGF pathway can have dose‐ and drug class‐dependent side‐effects on the host vasculature. These findings also advocate for the continued identification of mechanisms of resistance to anti‐angiogenics and for therapy development to overcome it. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.