bluuebunny/crossref_metadata_2025 huggingface dataset:
Comprehensive methodological analysis of long‐term changes in phenological extremes in Germany
Authors: Schleip Christoph , Ankerst Donna P. , Böck Andreas , Estrella Nicole , Menzel Annette
Published: March 2012

This study reports on alterations in the magnitude and frequency of extremes in reproductive phenology using long‐term records (1951–2008) for plant species widely distributed across Germany. For each of fourteen indicator phases studied, time series of annual onset dates at up to 119 stations, providing 50–58 years of observation, were standardized by their station mean and standard deviation. Four alternative statistical models were applied and compared to derive probabilities of extreme early or late onset times for the phases: (1) Gaussian models were used to describe decadal probabilities of standardized anomalies, defined by data either falling below the 5th or exceeding the 95th percentile. (2) Semi‐parametric quantile regression was employed for flexible and robust modelling of trends in different quantiles of onset dates. (3) Generalized extreme value distributions (GEV) were fitted to annual detrended minima and maxima of standardized anomalies, and (4) Generalized Pareto distributions (GPD) were fitted to extremes defined as peaks over threshold. Probabilities of extreme early phenological events inferred from Gaussian models, increased on average from 3 to 12%, whereas probabilities of extreme late phenological events decreased from 6 to 2% over the study period. Based on quantile regressions, summer and autumn phases revealed a more pronounced advancing pattern than spring phases. Estimated return levels by GEV were similar for the GPD methods, indicating that extreme early phenological events of magnitudes 2.5, 2.8, and 3.6 on the detrended standardized anomaly scale would occur every 20 years for spring, summer and autumn phases, respectively. This corresponds to absolute onset advances of up to 2 months depending on the season and species. This study demonstrates how extreme phenological events can be accurately modelled even in cases of inherently small numbers of observations, and underlines the need for additional evaluation related to their impacts on ecosystem functioning.
Climate shifts the interaction web of a marine plankton community
Authors: Francis Tessa B. , Scheuerell Mark D. , Brodeur Richard D. , Levin Phillip S. , Ruzicka James J. , Tolimieri Nick , Peterson William T.
Published: March 2012

Climatic effects in the ocean at the community level are poorly described, yet accurate predictions about ecosystem responses to changing environmental conditions rely on understanding biotic responses in a food‐web context to support knowledge about direct biotic responses to the physical environment. Here we conduct time‐series analyses with multivariate autoregressive (MAR) models of marine zooplankton abundance in the Northern California Current from 1996 to 2009 to determine the influence of climate variables on zooplankton community interactions. Autoregressive models showed different community interactions during warm vs. cool ocean climate conditions. Negative ecological interactions among zooplankton groups characterized the major warm phase during the time series, whereas during the major cool phase, ocean transport largely structured zooplankton communities. Local environmental conditions (sea temperature) and large‐scale climate indices (El Niño/Southern Oscillation) were associated with changes in zooplankton abundance across the full time series. Secondary environmental correlates of zooplankton abundance varied with ocean climate phase, with most support during the warm phase for upwelling as a covariate, and most support during the cool phase for salinity. Through simultaneous quantitation of community interactions and environmental covariates, we show that marine zooplankton community structure varies with climate, suggesting that predictions about ecosystem responses to future climate scenarios in the Northern California Current should include potential changes to the base of the pelagic food.
An investigation of striae distensae using reflectance confocal microscopy
Authors: Rolfe Heidi , Wurm Elisabeth , Gilmore Stephen
Published: March 2012

Background: Striae distensae, otherwise known as stretch marks, are white or red scar‐like streaks on the skin. Although they are not associated with adverse health outcomes, striae are associated with significant cosmetic morbidity. While they have been well characterised histopathologically, a non‐invasive method of microscopic lesion assessment of striae would be welcome.

Methods: To gain insight into the small‐scale morphological features associated with striae we undertook anin vivoinvestigation of nine patients with striae alba and one with striae rubra utilising reflectance confocal microscopy (RCM).

Results: Here we demonstrate that features known to be present using light microscopy, such as parallel collagen bundles in the dermis, and some features that are not well recognised by light microscopy, including distortion of dermal papillae, are demonstrable using RCM.

Conclusions: Characterising the features of early and established striae distensae with confocal microscopy is an important foundation for future work. The potential ability to reliably identify the earliest pathological changes in skin in early lesions or before clinically manifest striae develop – a task facilitated by our findings – will increase the understanding of their pathogenesis and will have significant practical utility in monitoring the impact of future preventative interventions.
Examining the orthopaedic examiners: reliability of the Part 2 Orthopaedic Clinical Fellowship Examination in Australia
Authors: Cundy Peter
Published: March 2012

Background:  The Final Examination for Orthopaedic Surgeons in Australia comprises seven components of which two are written responses and five are oral examinations involving separate pairs of examiners.

Methods:  The reliability of the examination process and close marking system was assessed by using a standardized DVD of a sham examination. Fifteen current examiners viewed the DVD and scored the viewed examination independently.

Results:  The results demonstrated consistency in scoring and reliability. This validation is likely to be further increased by the current system of the pairing of examiners. Additionally, the patient‐based examination segments were found to be as reliably scored as the criterion‐referenced computer‐based examination stations.

Conclusions:  Candidates for the Fellowship Examination should be reassured that this study has shown that the examination process has inter‐examiner reliability and consistency.
Exploring the Existence of Local and Global Knowledge Spillovers: Evidence from Plant‐Level Data*
Authors: Barrios Salvador , Bertinelli Luisito , Heinen Andreas , Strobl Eric
Published: March 2012

We investigate the existence of local (within‐country) and global (between‐country) knowledge spillovers within a single analytical framework. Our study is based on a detailed database of domestically owned and foreign‐affiliated manufacturing plants located in Ireland. The results of our econometric analysis show that domestically owned plants benefit from the research and development (R&D) activities of other domestically owned plants, as well as from R&D activities conducted in the country of origin of foreign‐owned plants through their presence in Ireland. A fundamental difference between such locally generated and locally transmitted global spillovers appears to be that the latter are much less constrained by distance decay effects.
The Political Business Cycle: New Evidence from the Nixon Tapes
Authors: ABRAMS BURTON A. , BUTKIEWICZ JAMES L.
Published: March 2012

Drawing from the personal tape recordings made during the presidency of Richard Nixon, we uncover and report in this paper new evidence that Nixon manipulated Arthur Burns and the Federal Reserve Bank into creating a political business cycle that helped secure Nixon's reelection victory in 1972. Nixon understood the risks that his desired monetary policy imposed but chose to trade longer‐term economic costs to the economy for his own short‐term political benefit.
Addressing the Issues: The Choice of Environmental Conflict‐Resolution Venues in the United States
Authors: Heikkila Tanya , Schlager Edella C.
Published: March 2012

Environmental conflicts are the catalyst for policy and institutional changes, and they are expected to increase due to rising populations, economic growth, and climate change impacts. Yet, environmental conflicts and the venues used to address them have not been thoroughly examined. A common‐pool resource dilemmas typology is used to categorize environmental conflict issues and to develop hypotheses relating conflict issues to resolution venues. The hypotheses are tested on western water‐resource conflicts. The capacity of venues to address the underlying conflict issues as well as how some venues tend to work in tandem are important for explaining the matching of conflict type to venue.
Are Stocks Really Less Volatile in the Long Run?
Authors: PÁSTOR ĽUBOŠ , STAMBAUGH ROBERT F.
Published: March 2012

According to conventional wisdom, annualized volatility of stock returns is lower over long horizons than over short horizons, due to mean reversion induced by return predictability. In contrast, we find that stocks are substantially more volatile over long horizons from an investor's perspective. This perspective recognizes that parameters are uncertain, even with two centuries of data, and that observable predictors imperfectly deliver the conditional expected return. Mean reversion contributes strongly to reducing long‐horizon variance but is more than offset by various uncertainties faced by the investor. The same uncertainties reduce desired stock allocations of long‐horizon investors contemplating target‐date funds.
Analysis of Variance: Variably Complex
Authors: DRUMMOND GORDON B. , VOWLER SARAH L.
Published: March 2012

Please cite this paper as: Drummond GB, Vowler SL. Analysis of variance: variably complex. Microcirculation 19: 280–283, 2012.
Performance Evaluation of Automated Fingerprint Identification Systems for Specific Conditions Observed in Casework Using Simulated Fingermarks
Authors: de Jongh Arent , Rodriguez Crystal M.
Published: March 2012

Abstract:  Few studies have been reported on the performance evaluation of automated fingerprint identification systems (AFIS) for fingermark‐to‐fingerprint comparisons. This paper aims to illustrate to fingerprint examiners the relevance of evaluating the AFIS performance under specific conditions by carrying out five types of performance tests. The conditions addressed are the number of minutiae assigned to a fingermark, manual and automatic assignment of the minutiae, the finger region from which the fingermark originates, the degree of distortion in the fingermark, and the difference in orientation between fingermarks and fingerprints. In these tests, the magnitude of the influence for each condition was quantified. The comparisons were performed using a research AFIS technology with simulated fingermarks. Simulated fingermarks provide a practical way to create fingermarks for specific conditions in large quantities. The results showed that each condition influences the performance significantly, emphasizing the relevance of developing, and applying performance tests for specific conditions.
Evaluating Equating Results: Percent Relative Error for Chained Kernel Equating
Authors: Jiang Yanlin , von Davier Alina A. , Chen Haiwen
Published: March 2012

This article presents a method for evaluating equating results. Within the kernel equating framework, the percent relative error (PRE) for chained equipercentile equating was computed under the nonequivalent groups with anchor test (NEAT) design. The method was applied to two data sets to obtain the PRE, which can be used to measure equating effectiveness. The study compared the PRE results for chained and poststratification equating. The results indicated that the chained method transformed the new form score distribution to the reference form scale more effectively than the poststratification method. In addition, the study found that in chained equating, the population weight had impact on score distributions over the target population but not on the equating and PRE results.
A Multilevel Testlet Model for Dual Local Dependence
Authors: Jiao Hong , Kamata Akihito , Wang Shudong , Jin Ying
Published: March 2012

The applications of item response theory (IRT) models assume local item independence and that examinees are independent of each other. When a representative sample for psychometric analysis is selected using a cluster sampling method in a testlet‐based assessment, both local item dependence and local person dependence are likely to be induced. This study proposed a four‐level IRT model to simultaneously account for dual local dependence due to item clustering and person clustering. Model parameter estimation was explored using the Markov Chain Monte Carlo method. Model parameter recovery was evaluated in a simulation study in comparison with three other related models: the Rasch model, the Rasch testlet model, and the three‐level Rasch model for person clustering. In general, the proposed model recovered the item difficulty and person ability parameters with the least total error. The bias in both item and person parameter estimation was not affected but the standard error (SE) was affected. In some simulation conditions, the difference in classification accuracy between models could go up to 11%. The illustration using the real data generally supported model performance observed in the simulation study.
Are the Distinctions Drawn in the Debate about End-of-Life Decision Making “Principled”? If Not, How Much Does it Matter?
Authors: Kamisar Yale
Published: March 2012

I sometimes wonder whether some proponents of physician-assisted suicide (PAS) or physician-assisted death (PAD) think they own the copyright to such catchy phrases as “death with dignity” and “a good death” so that if you are against PAS or PAD, thenyou must be againsta dignified death or a good death. If one removes the quotation marks around phrases like “aid-in-dying” or “compassionate care for the dying,” I am not opposed to such end-of-life care either. Indeed, how couldanybodybe against this type of care?

I do not want to abandon dying patients anymore than Dr. Timothy Quill does. Although, unfortunately, it will not always be easy to achieve the desired result, I agree with him that it ought to be a goal of medicine “to help people die well, to help them receive a good death” — or at least “the best possible” death under the circumstances. I part company with Professor Quill, however, when he urges us to change the law in the majority of our states so that in some circumstances patients may achieve a “good death” or a “dignified” one by means of lethal drugs.
Conflicts among Multinational Ethical and Scientific Standards for Clinical Trials of Therapeutic Interventions
Authors: Kolman Jacob M. , Wray Nelda P. , Ashton Carol M. , Wenner Danielle M. , Jarman Anna F. , Brody Baruch A.
Published: March 2012

There has been a growing concern over establishing norms that ensure the ethically acceptable and scientifically sound conduct of clinical trials. Among the leading norms internationally are the World Medical Association's Declaration of Helsinki, guidelines by the Council for International Organizations of Medical Sciences (CIOMS), the International Conference on Harmonization's standards for industry (ICH), and the CONSORT group's reporting norms (Consolidated Standards of Reporting Trials), in addition to the influential U.S. Federal Common Rule, Food and Drug Administration's (FDA) body of regulations, and information sheets by the Department of Health and Human Services. There are also many norms published at more local levels by official agencies and professional groups.

Any account of international standards should cover both scientific and ethical norms at once – the two are conceptually intertwined. Recent sources recognize that “[s]cientifically unsound research on human subjects is unethical in that it exposes research subjects to risks without possible benefit.”
A short note on the horizontal and vertical movements of a whale shark, Rhincodon typus, tracked by satellite telemetry in the South China Sea
Authors: WANG Yamin , LI Wei , ZENG Xiaoguang , CUI Yunchen
Published: March 2012

Whale sharks, a global migratory species, are often reported entangled in fishing nets in coastal areas of China. The effectiveness of conservation measures has been constrained by very limited knowledge on their movements and preferred habitats in the coastal areas of China. For the first time, we tracked the movements of 2 whale sharks by satellite telemetry in Mainland China. The tracking results of 1 whale shark revealed that it travelled in the South China Sea in a south‐eastern direction, parallel to the eastern coast of Vietnam. Total distance travelled was 1018 km, in approximately 74 days, with a mean speed of 14 km per day. It appeared to head towards the cool upwelling zones in southern Vietnam at the time of the tag's detachment. In our study, it was observed that this whale shark was a surface dweller and spent approximately 45% of its time above 10 m water depth and 90% of its time above 50 m depth. It also tended to stay in water temperatures between 27 and 30 °C, and was rarely recorded in water below 20 °C. This preliminary study indicates the importance of shallow waters as the foraging habitat for whale sharks, and has implications for their management and conservation.
Investigating Arabia Mountain: A Molecular Approach
Authors: Jacob Nitya P.
Published: March 2012

“Investigating Microbial Diversity on Arabia Mountain,” the IBI Prize–winning module, allows students to explore microbial diversity by DNA isolation and sequencing.
Cotranscriptional Role for
Arabidopsis
DICER-LIKE 4 in Transcription Termination
Authors: Liu Fuquan , Bakht Saleha , Dean Caroline
Published: March 2012

Making the CoTC

In eukaryotes, cotranscriptional cleavage (CoTC) of nascent RNA transcripts at the polyadenylation (polyA) site is involved in transcription termination of RNA polymerase II genes. The Dicer endoribonucleases, on the other hand, are generally associated with gene silencing through the generation of small RNAs from double-stranded RNA. Now,

Liu
et al.

(p.
1621
) show that transcriptional read-through of the
Arabidopsis FCA
gene is regulated by
DICER-LIKE 4
(
DCL4
). DCL4 associated with the
FCA
gene downstream of the polyA site and repressed transcriptional read-through. The C terminus of DCL4 has a similar domain structure to the yeast endoribonuclease Rnt1, involved in CoTC, which suggests that DCL4 is involved in repressing read-through of endogenous
FCA
by prompting cotranscriptional cleavage.
238
U/
235
U Systematics in Terrestrial Uranium-Bearing Minerals
Authors: Hiess Joe , Condon Daniel J. , McLean Noah , Noble Stephen R.
Published: March 2012

A Better Date

Uranium-lead (U-Pb) dating, which is one of the most commonly used methods of radiometric dating for old terrestrial materials, operates by comparing the ratio of trace levels of U with its nuclear decay product Pb. This dating method, and the similar Pb-Pb method, assumes that the ratio between the two most common U isotopes (
238
U and
235
U) is constant. By accurately measuring the
238
U/
235
U ratio in a suite of minerals representing a range of tectonic environments,

Hiess
et al.

(p.
1610
; see the Perspective by

Stirling

) demonstrate that this ratio is more variable than was previously thought. The variability does not reflect any systematic bias with time, location, or temperature—suggesting that ideally
238
U/
235
U should be determined for every sample to calculate ages. In the absence of such data, a revised
238
U/
235
U ratio for zircon minerals could significantly modify previous age estimates using U-Pb and Pb-Pb dating techniques.
Comment on “Disentangling the Drivers of β Diversity Along Latitudinal and Elevational Gradients”
Authors: Qian Hong , Wang Xianli , Zhang Yangjian
Published: March 2012

Kraft
et al
. (Report, 23 September 2011, p. 1755) analyzed two data sets and concluded that “there is no need to invoke differences in the mechanisms of community assembly in temperate versus tropical systems to explain these global-scale patterns of β diversity.” We show that their conclusion is based on inappropriate data and inadequate methods of analysis.
Field Research on Bees Raises Concern About Low-Dose Pesticides
Authors: Stokstad Erik
Published: March 2012

Two field studies reported online this week in
Science
document evidence that systemic insecticides, a common way to protect crops, indirectly harm bees.
Hepatitis C Virus Activates the mTOR/S6K1 Signaling Pathway in Inhibiting IRS-1 Function for Insulin Resistance
Authors: Bose Sandip K. , Shrivastava Shubham , Meyer Keith , Ray Ratna B. , Ray Ranjit
Published: March 2012

Hepatitis C virus (HCV) infection significantly increases the prevalence of type 2 diabetes mellitus (T2DM). Insulin receptor substrate 1 (IRS-1) plays a key role in insulin signaling, thus enabling metabolic regulation in mammalian cells. We have previously shown that HCV infection modulates phosphorylation of Akt, a downstream target of IRS-1. In this study, we further examined the status of total IRS-1 and the downstream regulation of the Akt pathway in understanding mTOR/S6K1 signaling using HCV genotype 2a (clone JFH1)-infected hepatocytes. Inhibition of IRS-1 expression was observed in HCV-infected hepatocytes compared to that in a mock-infected control. The status of the tuberous sclerosis complex (TSC-1/TSC-2) was significantly decreased after HCV infection of human hepatocytes, showing a modulation of the downstream Akt pathway. Subsequent study indicated an increased level of Rheb and mTOR expression in HCV-infected hepatocytes. Interestingly, the phosphoS6K1 level was higher in HCV-infected hepatocytes, suggesting a novel mechanism for IRS-1 inhibition. Ectopic expression of TSC-1/TSC-2 significantly recovered the IRS-1 protein expression level in HCV-infected hepatocytes. Further analyses indicated that HCV core protein plays a significant role in modulating the mTOR/S6K1 signaling pathway. Proteasome inhibitor MG 132 recovered IRS-1 and TSC1/2 expression, suggesting that degradation occurred via the ubiquitin proteasome pathway. A functional consequence of IRS-1 inhibition was reflected in a decrease in GLUT4 protein expression and upregulation of the gluconeogenic enzyme PCK2 in HCV-infected hepatocytes. Together, these observations suggested that HCV infection activates the mTOR/S6K1 pathway in inhibiting IRS-1 function and perturbs glucose metabolism via downregulation of GLUT4 and upregulation of PCK2 for insulin resistance.
Mus spicilegus Endogenous Retrovirus HEMV Uses Murine Sodium-Dependent Myo-Inositol Transporter 1 as a Receptor
Authors: Tipper Christopher H. , Cingöz Oya , Coffin John M.
Published: March 2012

We sought to determine the relationship between two recent additions to the murine leukemia virus (MLV) ecotropic subgroup:
Mus cervicolor
isolate M813 and
Mus spicilegus
endogenous retrovirus HEMV. Though divergent in sequence, the two viruses share an Env protein with similarly curtailed VRA and VRB regions, and infection by both is restricted to mouse cells. HEMV and M813 displayed reciprocal receptor interference, suggesting that they share a receptor. Expression of the M813 receptor murine sodium-dependent myo-inositol transporter 1 (mSMIT1) allowed previously nonpermissive cells to be infected by HEMV, indicating that mSMIT1 also serves as a receptor for HEMV. Our findings add HEMV as a second member to the MLV subgroup that uses mSMIT1 to gain entry into cells.
Deep Sequencing Reveals Minor Protease Resistance Mutations in Patients Failing a Protease Inhibitor Regimen
Authors: Fisher Randall , van Zyl Gert U. , Travers Simon A. A. , Kosakovsky Pond Sergei L. , Engelbrech Susan , Murrell Ben , Scheffler Konrad , Smith Davey
Published: March 2012

Standard genotypic antiretroviral resistance testing, performed by bulk sequencing, does not readily detect variants that comprise <20% of the circulating HIV-1 RNA population. Nevertheless, it is valuable in selecting an antiretroviral regimen after antiretroviral failure. In patients with poor adherence, resistant variants may not reach this threshold. Therefore, deep sequencing would be potentially valuable for detecting minority resistant variants. We compared bulk sequencing and deep sequencing to detect HIV-1 drug resistance at the time of a second-line protease inhibitor (PI)-based antiretroviral regimen failure. Eligibility criteria were virologic failure (HIV-1 RNA load of >500 copies/ml) of a first-line nonnucleoside reverse transcriptase inhibitor-based regimen, with at least the M184V mutation (lamivudine resistance), and second-line failure of a lopinavir/ritonavir (LPV/r)-based regimen. An amplicon-sequencing approach on the Roche 454 system was used. Six patients with viral loads of >90,000 copies/ml and one patient with a viral load of 520 copies/ml were included. Mutations not detectable by bulk sequencing during first- and second-line failure were detected by deep sequencing during second-line failure. Low-frequency variants (>0.5% of the sequence population) harboring major protease inhibitor resistance mutations were found in 5 of 7 patients despite poor adherence to the LPV/r-based regimen. In patients with intermittent adherence to a boosted PI regimen, deep sequencing may detect minority PI-resistant variants, which likely represent early events in resistance selection. In patients with poor or intermittent adherence, there may be low evolutionary impetus for such variants to reach fixation, explaining the low prevalence of PI resistance.
Human Monoclonal Antibodies to Pandemic 1957 H2N2 and Pandemic 1968 H3N2 Influenza Viruses
Authors: Krause Jens C. , Tsibane Tshidi , Tumpey Terrence M. , Huffman Chelsey J. , Albrecht Randy , Blum David L. , Ramos Irene , Fernandez-Sesma Ana , Edwards Kathryn M. , García-Sastre Adolfo , Basler Christopher F. , Crowe James E.
Published: March 2012

Investigation of the human antibody response to the 1957 pandemic H2N2 influenza A virus has been largely limited to serologic studies. We generated five influenza virus hemagglutinin (HA)-reactive human monoclonal antibodies (MAbs) by hybridoma technology from the peripheral blood of healthy donors who were born between 1950 and 1968. Two MAbs reacted with the pandemic H2N2 virus, two recognized the pandemic H3N2 virus, and remarkably, one reacted with both the pandemic H2N2 and H3N2 viruses. Each of these five naturally occurring MAbs displayed hemagglutination inhibition activity, suggesting specificity for the globular head domain of influenza virus HA. When incubated with virus, MAbs 8F8, 8M2, and 2G1 each elicited H2N2 escape mutations immediately adjacent to the receptor-binding domain on the HA globular head in embryonated chicken eggs. All H2N2-specific MAbs were able to inhibit a 2006 swine H2N3 influenza virus. MAbs 8M2 and 2G1 shared the V
H
1-69 germ line gene, but these antibodies were otherwise not genetically related. Each antibody was able to protect mice in a lethal H2N2 virus challenge. Thus, even 43 years after circulation of H2N2 viruses, these subjects possessed peripheral blood B cells encoding potent inhibiting antibodies specific for a conserved region on the globular head of the pandemic H2 HA.
Leadership competencies for medical education and healthcare professions: population-based study
Authors: Çitaku Fadil , Violato Claudio , Beran Tanya , Donnon Tyrone , Hecker Kent , Cawthorpe David
Published: March 2012

Objective

To identify and empirically investigate the dimensions of leadership in medical education and healthcare professions.

Design

A population-based design with a focus group and a survey were used to identify the perceived competencies for effective leadership in medical education.

Setting

The focus group, consisting of five experts from three countries (Austria n=1; Germany n=2; Switzerland n=2), was conducted (all masters of medical education), and the survey was sent to health professionals from medical schools and teaching hospitals in six countries (Austria, Canada, Germany, Switzerland, the UK and the USA).

Participants

The participants were educators, physicians, nurses and other health professionals who held academic positions in medical education. A total of 229 completed the survey: 135 (59.0%) women (mean age=50.3 years) and 94 (41.0%) men (mean age=51.0 years).

Measures

A 63-item survey measuring leadership competencies was developed and administered via electronic mail to participants.

Results

Exploratory principal component analyses yielded five factors accounting for 51.2% of the variance: (1) social responsibility, (2) innovation, (3) self-management, (4) task management and (5) justice orientation. There were significant differences between physicians and other health professionals on some factors (Wilk's λ=0.93, p<0.01). Social responsibility was rated higher by other health professionals (M=71.09) than by physicians (M=67.12), as was innovation (health professionals M=80.83; physicians M=76.20) and justice orientation (health professionals M=21.27; physicians M=20.46).

Conclusions

The results of the principal component analyses support the theoretical meaningfulness of these factors, their coherence, internal consistency and parsimony in explaining the variance of the data. Although there are some between-group differences, the competencies appear to be stable and coherent.
New windows to enhance direct reprogramming of somatic cells towards induced pluripotent stem cells
Authors: Nakhaei-Rad Saeideh , Bahrami Ahmad R. , Mirahmadi Mahdi , Matin Maryam M.
Published: March 2012

Induced pluripotent stem cells are generated by direct reprogramming of somatic cells with the introduction of defined transcription factors or other means. Clinical applications of induced pluripotent stem cells are the latest of stem cell therapy approaches due to overcoming problems associated with insufficient cells from conventional sources and immune rejections. In practice, this is restricted by 4 major barriers including the use of genetic manipulations for delivering the reprogramming factors, low efficiency of this process, slow kinetics of the direct reprogramming, and potential for tumor development. Here, we review the latest achievements in improving reprogramming efficiency by alternative strategies. These alternatives mainly involve the replacement of genetic reprogramming factors with small molecules or other factors.
Changes in the levels of thioredoxin and indoleamine-2,3-dioxygenase activity in plasma of patients with colorectal cancer treated with chemotherapy
Authors: Cavia-Saiz Monica , Muñiz Pilar , De Santiago Reyes , Herreros-Villanueva Marta , Garcia-Giron Carlos , Lopez Ana Sofia , Coma-del Corral Maria Jesus
Published: March 2012

Increased oxidative stress and indoleamine-2,3-dioxygenase (IDO) activity have been reported in cancer, but their relationship with chemotherapy remains unknown. The aim of the present study was to examine wether the chemotherapy treatments used in colorectal cancer had an additional effect on oxidative stress and on IDO activity. Plasma samples were collected from 27 colorectal cancer patients on cytostatic treatment, 27 with cytostatic drugs plus monoclonal antibodies (cytostatic-Mabs) and 15 non-treated patients. All patients with colorectal cancer had high plasma malondialdehyde (MDA), thioredoxin (Trx) levels, and elevated IDO activity in plasma (IDOp) and in dendritic cells (IDOc). This study shows that treatment with cytostatics have an effect on oxidative stress by increasing MDA levels and by decreasing Trx levels and IDO activity. However, treatment with cytostatic-Mabs showed no effect on MDA levels but decreased Trx levels, and the IDO activity showed values similar to the healthy group. Significant correlations between plasma IDO activity and the levels of Trx (r = 0.2062, p < 0.05) and MDA (r = 0.2873, p < 0.005) were observed. Furthermore, our study suggests that IDO activity measured as kynurenine levels could be used as a marker of the response to the chemotherapy treatments, although further studies are necessary.
Time-dependent behaviour of the Bearpaw Shale in oedometric loading and unloading
Authors: Powell J. Suzanne , Take W. Andy , Siemens Greg , Remenda V.H.
Published: March 2012

Time-dependent behaviour can have a significant influence on the compressibility characteristics of soils. However, most of the research on this topic has investigated the behaviour of soft soils. In this paper, the time-dependent behaviour of a hard clay shale (Bearpaw Shale) is investigated using both one-dimensional multi-staged loading (MSL) oedometer and constant rate of strain (CRS) oedometer consolidation tests conducted on 25.0 and 16.9 mm diameter specimens. The results show that soft clays and hard clay shales that share the same Cαe/[Formula: see text] ratio (where Cαeis the secondary compression index and [Formula: see text] is the incremental compression index) will show the same approximately 7% change in pre-consolidation pressure for an increase of one log cycle of strain rate despite the many orders of magnitude difference in pre-consolidation pressure. In the case of the Bearpaw Shale, this 7% change in pre-consolidation pressure corresponds to approximately 700 kPa. The time-dependent behaviour of the Bearpaw Shale during unloading (Cαe/[Formula: see text], where [Formula: see text] is the incremental swelling index) was observed to follow a similar ratio to that observed in compression (Cαe/[Formula: see text]). While the exact nature of the compression and swelling events that have occurred over the life of the Bearpaw Formation is not clear, the influence of secondary compression cannot be ignored for interpretation of the geological history of this deposit.
Flexural behaviour of a clay layer: experimental and numerical study
Authors: Plé O. , Manicacci A. , Gourc J.P. , Camp S.
Published: March 2012

Solid waste landfills consist of a cover barrier that often includes a compacted clay liner. However, this barrier can encounter numerous problems, in particular those related to in situ implementation and to mechanical loading that may cause stress in the clay layer, leading to the development of cracks. Tensile stress damage and shearing bands are often observed. To characterize the behaviour of a clay in tension, four-point bending tests attempting to reproduce conditions of implementation were carried out in the laboratory. At the same time, original large-scale bursting tests were carried out in the field for validation. To interpret these results, a numerical simulation was used, which was calibrated with laboratory results and then applied to large-scale bursting tests. This simulation was then used to simulate the flexural behaviour of the cover barrier. By focusing on the most critical case, the numerical simulation is able to predict the initiation of cracks.
Two new one-dimensional coordination polymers containing [N(CN)2]– — Syntheses, structures, and magnetic properties of [MII(3- Bzpy)2(N(CN)2)2] (M = Mn (1) and Co (2) and 3-Bzpy = 3-benzoylpyridine)
Authors: Bao Qianqian , Ma Yutao , Zhao Qihua , Luo Yanghui , Sun Baiwang
Published: March 2012

The structures of two one-dimensional coordination complexes, [MII(3-Bzpy)2(N(CN)2)2] (M = Mn (1) and Co (2) and 3-Bzpy = 3-benzoylpyridine), have been determined in this work. The two structures are isomorphous, crystallize in a monoclinic P21/c space group, and show almost the same crystal structure. The magnetic measurements of the two compounds (2–300 K) indicate that antiferromagnetic exchanges exist between the metal ions of the two compounds.
Forest mortality in high-elevation whitebark pine (Pinus albicaulis) forests of eastern California, USA; influence of environmental context, bark beetles, climatic water deficit, and warming
Authors: Millar Constance I. , Westfall Robert D. , Delany Diane L. , Bokach Matthew J. , Flint Alan L. , Flint Lorraine E.
Published: March 2012

Whitebark pine ( Pinus albicaulis Engelm.) in subalpine zones of eastern California experienced significant mortality from 2007 to 2010. Dying stands were dense (mean basal area 47.5 m2/ha), young (mean 176 years), and even-age; mean stand mortality was 70%. Stands were at low elevations (mean 2993 m), on northerly aspects, and experienced warmer, drier climates relative to the regional species distribution. White pine blister rust was not observed; mountain pine beetle infestations were extensive. Ring widths were negatively correlated with climatic water deficit and positively correlated with water-year precipitation. Although trees that survived had greater growth during the 20th century than trees that died, in the 19th century trees that eventually died grew better than trees that survived, suggesting selection for genetic adaptation to current climates as a result of differential tree mortality. Air surveys (2006–2010) in the Sierra Nevada, Mt. Shasta, and Warner Mountains showed similar trends to the intensive studies. Observed mortality from air surveys was highest in the Warner Mountains (38%) and lowest in the Sierra Nevada (5%); northern aspects at lower elevations within each mountain region had the highest probabilities of mortality and dying stands had higher climatic water deficit. Scenarios for the future of whitebark pine in California are discussed.
APPROXIMATE ROTATIONAL SOLUTIONS OF PENDULUM UNDER COMBINED VERTICAL AND HORIZONTAL EXCITATION
Authors: PAVLOVSKAIA EKATERINA , HORTON BRYAN , WIERCIGROCH MARIAN , LENCI STEFANO , REGA GIUSEPPE
Published: March 2012

A pendulum excited by the combination of vertical and horizontal forcing at the pivot point was considered and the period-1 rotational motion was studied. Analytical approximations of period-1 rotations and their stability boundary on the excitation parameters (ω, p)-plane are derived using asymptotic analysis for the pendulum excited elliptically and along a tilted axis. It was assumed that the damping is small and the frequency of the base excitation is relatively high. The accuracy of the approximations was examined for different values of the parameters e and κ controlling the shape of excitation, and it was found that using the second and third order approximations ensures a good correspondence between analytical and numerical results in the majority of cases. Basins of attractions of the coexisting solutions were constructed numerically to evaluate the robustness of the obtained rotational solutions. It was found that the horizontal component of excitation has a larger effect on the shift in position of the saddle node bifurcations for the elliptically excited case than for the pendulum excited along a tilted axis. For the elliptically excited pendulum with pivot rotating in the same direction as the pendulum the stability boundary is shifted downwards providing a larger region of the solution existence. When the pendulum and the pivot rotate in opposite directions, the boundary is shifted upwards significantly limiting the region of the solution existence. In contrast, for the pendulum excited along the tilted axis, the direction of the rotation has a minor effect for low frequency values and the addition of the horizontal component always results in a larger region of the solution existence.
BIFURCATION AND CHAOS ANALYSIS FOR A DELAYED TWO-NEURAL NETWORK WITH A VARIATION SLOPE RATIO IN THE ACTIVATION FUNCTION
Authors: SONG ZIGEN , XU JIAN
Published: March 2012

In this paper, some complex phenomena of dynamical bifurcations are shown for a two-neural network with delay coupling. The sigmoid activation function with slope ratio, a monotonically increasing function, is proposed to consider the relations of the sigmoid and Hardlim functions. The equilibrium points are studied analytically in detail in terms of the characteristic equation and static bifurcation. The central manifold reduction and normal form method are employed to determine Hopf bifurcation and its stability. The stable equilibrium points and periodic motions are observed in different parameter regions. Effects of slope ratio and delayed coupling on dynamic behaviors are investigated by the numerical simulation, such as Poincare map, phase portraits, and power spectrum. Various active transitions to chaos and the corresponding critical boundaries on the focused parameter regions are obtained to classify dynamical behaviors including stable equilibrium point, periodic solution, 2-torus, 3-torus, and then the chaotic motions.
NOISE-INDUCED PATTERN FORMATION AND SYNCHRONIZATION IN A SQUARE-LATTICE NEURONAL NETWORK
Authors: ZHENG YANHONG , WANG QINGYUN , GAN CHUNBIAO
Published: March 2012

Effects of noise on the collective dynamic phenomena such as patterns and firing synchronization are studied in a square-lattice FitzHugh–Nagumo neural network with gap junctions. It is shown that as the noise intensity is above a critical value, typical patterns can emerge and propagate through the network in the form of coexisting circular waves and parallel ones with spatially periodic structure. Circular waves can change from a single-array to double-array as the noise increases. Furthermore, we can observe that spatial evolutions of patterns can exhibit different styles as the noise is changed. In addition, we study noise-induced firing synchronization of neurons. In particular, firing synchronization can be enhanced, and then can reach a saturated value as the noise is large enough. More interestingly, it is found that the stronger the coupling strength is, the larger the noise intensity is needed to make neurons fire. Finally, the critical relation between the noise intensity and the coupling strength is given to investigate the occurrence of firing synchronization in the network.
DYNAMICAL BEHAVIORS AND NUMERICAL SIMULATION OF A LORENZ-TYPE SYSTEM FOR THE INCOMPRESSIBLE FLOW BETWEEN TWO CONCENTRIC ROTATING CYLINDERS
Authors: WANG HEYUAN
Published: March 2012

In this paper, we investigate the problem of dynamical behaviors and numerical simulation of Lorenz systems for the incompressible flow between two concentric rotating cylinders. A spectral Galerkin method is used to derive a model system of axisymmetric Couette–Taylor flow, a three-mode system, which is structurally similar to the Lorenz system, is obtained by a suitable three-mode truncation of the Navier–Stokes equations for the incompressible flow between two concentric rotating cylinders. The stability of the three-mode system is discussed, the existence of its attractor is given. Moreover, numerical simulation results indicate that this low-dimensional model exhibits a route to chaos via a period doubling cascade. Using these numerical results we explain successive transitions of Couette–Taylor flow from Laminar flow to turbulence in the experiment.
WORD AND CATEGORY LEARNING IN A CONTINUOUS SEMANTIC DOMAIN: COMPARING CROSS-SITUATIONAL AND INTERACTIVE LEARNING
Authors: BELPAEME TONY , MORSE ANTHONY
Published: March 2012

The problem of how young learners acquire the meaning of words is fundamental to language development and cognition. A host of computational models exist which demonstrate various mechanisms in which words and their meanings can be transferred between a teacher and learner. However these models often assume that the learner can easily distinguish between the referents of words, and do not show if the learning mechanisms still function when there is perceptual ambiguity about the referent of a word. This paper presents two models that acquire meaning-word mappings in a continuous semantic space. The first model is a cross-situational learning model in which the learner induces word-meaning mappings through statistical learning from repeated exposures. The second model is a social model, in which the learner and teacher engage in a dyadic learning interaction to transfer word-meaning mappings. We show how cross-situational learning, despite there being no information to the learner as to the exact referent of a word during learning, still can learn successfully. However, social learning outperforms cross-situational strategies both in speed of acquisition and performance. The results suggest that cross-situational learning is efficient for situations where referential ambiguity is limited, but in more complex situations social learning is the more optimal strategy.
Default Mode Network Activity and Connectivity in Psychopathology
Authors: Whitfield-Gabrieli Susan , Ford Judith M.
Published: March 2012

Neuropsychiatric disorders are associated with abnormal function of the default mode network (DMN), a distributed network of brain regions more active during rest than during performance of many attention-demanding tasks and characterized by a high degree of functional connectivity (i.e., temporal correlations between brain regions). Functional magnetic resonance imaging studies have revealed that the DMN in the healthy brain is associated with stimulus-independent thought and self-reflection and that greater suppression of the DMN is associated with better performance on attention-demanding tasks. In schizophrenia and depression, the DMN is often found to be hyperactivated and hyperconnected. In schizophrenia this may relate to overly intensive self-reference and impairments in attention and working memory. In depression, DMN hyperactivity may be related to negative rumination. These findings are considered in terms of what is known about psychological functions supported by the DMN, and alteration of the DMN in other neuropsychiatric disorders.
Design Mixers to Minimize Effects of Erosion and Corrosion Erosion
Authors: Fasano Julian , Janz Eric E. , Myers Kevin
Published: March 2012

A thorough review of the major parameters that affect solid-liquid slurry wear on impellers and techniques for minimizing wear is presented. These major parameters include (i) chemical environment, (ii) hardness of solids, (iii) density of solids, (iv) percent solids, (v) shape of solids, (vi) fluid regime (turbulent, transitional, or laminar), (vii) hardness of the mixer's wetted parts, (viii) hydraulic efficiency of the impeller (kinetic energy dissipation rates near the impeller blades), (ix) impact velocity, and (x) impact frequency. Techniques for minimizing the wear on impellers cover the choice of impeller, size and speed of the impeller, alloy selection, and surface coating or coverings. An example is provided as well as an assessment of the approximate life improvement.
Lipophagy: Connecting Autophagy and Lipid Metabolism
Authors: Singh Rajat , Cuervo Ana Maria
Published: March 2012

Lipid droplets (LDs), initially considered “inert” lipid deposits, have gained during the last decade the classification of cytosolic organelles due to their defined composition and the multiplicity of specific cellular functions in which they are involved. The classification of LD as organelles brings along the need for their regulated turnover and recent findings support the direct contribution of autophagy to this turnover through a process now described as lipophagy. This paper focuses on the characteristics of this new type of selective autophagy and the cellular consequences of the mobilization of intracellular lipids through this process. Lipophagy impacts the cellular energetic balance directly, through lipid breakdown and, indirectly, by regulating food intake. Defective lipophagy has been already linked to important metabolic disorders such as fatty liver, obesity and atherosclerosis, and the age-dependent decrease in autophagy could underline the basis for the metabolic syndrome of aging.