bluuebunny/crossref_metadata_2025 huggingface dataset:
Machiavellianism and Executive Functioning in Patients with Delusional Disorder
Authors: Brüne Martin , Basilowski Miriam , Bömmer Isabel , Juckel Georg , Assion Hans-Jörg
Published: May 2010

Previous research has demonstrated that patients with Delusional Disorder are impaired in executive functioning that affects performance on social cognitive tasks. In patients with Parkinson's disease, poor executive control induces an increase in “Machiavellianism,” a term that refers to opportunistic behaviors that aim at exploiting and manipulating others. Accordingly, the association between Machiavellianism in Delusional Disorder and executive functioning deficits was examined. Machiavellianism and executive functioning were measured in 22 patients with Delusional Disorder and compared with a group of 22 healthy controls matched for sex, (premorbid) intelligence, and education. Patients and controls did not differ regarding Machiavellianism scores, education level, or intelligence. However, patients with Delusional Disorder performed more poorly on an executive functioning task. Impaired executive functioning was associated with greater Machiavellianism, particularly cynical views on human nature, but not with intelligence or illness duration. Similar to findings in patients with Parkinson's disease, Machiavellianism in Delusional Disorder was associated with poorer executive functioning. This finding indicates that frontal lobe dysfunction may influence interpersonal attitudes and personality in Delusional Disorder.
An International Comparison of Grade 6 Students' Understanding of the Equal Sign
Authors: Capraro Robert M. , Capraro Mary Margaret , Yetkiner Z. Ebrar , Özel Serkan , Kim Hae Gyu , Küçük Ali Riza
Published: May 2010

This study extends the scope of international comparisons examining students' conceptions of the equal sign. Specifically, Korean ( n = 193) and Turkish ( n = 334) Grade 6 students were examined to assess whether their conceptions and responses were similar to prior findings published for Chinese and U.S. students and to hypothesize relationships about problem types and conceptual understanding of the equal sign. About 59.6% of the Korean participants correctly answered all items providing conceptually accurate solutions, as compared to 28.4% of the Turkish sample. Comparison with previous studies in China and the USA indicated that the Chinese sample outperformed those from other nations, followed by Korea, Turkey, and the USA. In large-scale international studies such as Trends in International Mathematics and Science (TIMSS) and the Programme for International Student Assessment (PISA), students from China and Korea have been among the high achievers.
Chilean Experimental Version of the State-Trait Depression Questionnaire (ST–DEP): State Subscale (S–DEP)
Authors: Vera-Villarroel Pablo , Buela-Casal Gualberto , Zych Izabela , Córdova-Rubio Natalia , Celis-Atenas Karem , Zepeda Lorena , Spielberger Charles D.
Published: May 2010

Depression is the most prevalent mental disorder and one of the most important health problems in Chile. The current study shows data for validity and reliability of the State subscale (S–DEP) of the Chilean experimental version of the State-Trait Depression Questionnaire (ST–DEP). The procedure conducted with the original version of the questionnaire was replicated on a sample of 300 university students. The utilized measures were the State Depression Questionnaire, Beck Depression Inventory, the State-Trait Anxiety Inventory, and neutral depressive, mild depressive, and moderate depressive vignettes. Results indicated that the factor structure was replicable, the internal consistency was good, and the situations were ranked as expected. The scale distinguishes intensities of depression. Clinicians and researchers in Chile are provided with a new measure for state depression.
Dialectical Thinking and Creativity among Young Adults: A Postformal Operations Perspective
Authors: Yang Chao-Chin , Wan Chin-Shen , Chiou Wen-Bin
Published: May 2010

This study used a post-Piagetian perspective to investigate the relation of dialectical thinking and creative performance in early adulthood. The modified version of the Social Paradigm Belief Scale was employed to measure the development of formal and dialectical thinking among 454 young adults, ages 23 to 40 years ( M = 32.1, SD = 4.8). The Divergent Thinking Test estimated their creative performance. Scores on dialectical thinking were positively correlated and scores on formal thinking were negatively correlated with Divergent Thinking Test scores. Planned contrasts indicated that participants in the dialectical thinking group scored higher than did those in the formal thinking group on the six dimensions of the Divergent Thinking Test, i.e., Fluency, Openness, Flexibility, Originality, Elaboration, and Naming. Multiple discriminant analysis with a cross-validation examination showed the linear combination of scores on the six dimensions of creativity included in the Divergent Thinking Test discriminated between formal and dialectical thinking groups; this supported predictions about the relation between postformal thinking and creativity among young adults.
Correction for Rhiel's Theory for the Range Estimator of the Coefficient of Variation for Skewed Distributions
Authors: Rhiel G. Steven
Published: May 2010

In 2007, Rhiel presented a technique to estimate the coefficient of variation from the range when sampling from skewed distributions. To provide an unbiased estimate, a correction factor ( an) for the mean was included. Numerical correction factors for a number of skewed distributions were provided. In a follow-up paper, he provided a proof he claimed showed the correction factor was independent of the mean and standard deviation, making the factors useful as these parameters vary; however, that proof did not establish independence. Herein is a proof which establishes the independence.
The Effect of Direction, Self-Relevance, and Focus of Social Comparisons on Self-Evaluation: Interpretation via Assimilation and Contrast Effects
Authors: Tsai Chia-Ching
Published: May 2010

This study investigated the effect of direction, self-relevance, and focus of social comparisons on self-evaluation. 160 participants (76 men, 84 women; 19–27 years old) were enrolled from a marketing class. Using self as the focus of comparison will cause a contrast effect, while using others as the focus of comparison will have an assimilation effect. When the comparison dimension is highly self-relevant, a contrast effect will be observed on self-evaluation, while an assimilation effect will be observed when the comparison dimension is low on self-relevance. Also, when self is the focus of comparison, a highly self-relevant comparison dimension will make the contrast effect stronger, while a dimension with low self-relevance will make the contrast effect weaker. Conversely, when others are the focus of comparison, a comparison dimension that has low self-relevance will make the assimilation effect stronger, while a highly self-relevant one will weaken it. Primary results in this study were an interaction of comparison direction by focus of comparison and an interaction of comparison direction by self-relevance on self-evaluation.
Illness Duration and Coping Style in Chronic Fatigue Syndrome
Authors: Brown Molly M. , Brown Abigail A. , Jason Leonard A.
Published: May 2010

A sample of patients with chronic fatigue syndrome was recruited to assess coping strategies and illness duration. It was hypothesized that adaptive coping strategies would be higher among those with longer illness duration. Those in the longer illness duration group reported higher use of active coping, positive reframing, planning, and acceptance, and lower use of behavioral disengagement than those in the shorter illness duration group. No significant differences were found between the two illness duration groups for physical impairment or symptom severity, but the long duration group revealed a lower percentage of participants who were working than the short duration group. These findings suggest that individuals with longer or shorter duration of the illness have differences in coping styles but not differences in physical impairment or symptom severity.
Self-Concept in Lebanese and Arab-American Pre-Adolescents
Authors: Alkhateeb Haitham M.
Published: May 2010

The present study assessed self-concepts of 102 (35 boys, 67 girls) Arab-American pre-adolescents ( M age = 11.9 yr., SD = .8) and compared scores with those of 105 (43 boys, 62 girls) Arab national students ( M age = 12.3 yr., SD = .7) in Lebanon. The Arab-American students scored significantly higher than the group of Arab students in Lebanon on 6 of 8 subscales of Marsh's Self-description Questionnaire–I, suggesting overall higher self-concept on subscales for physical ability, physical appearance, peer relations, reading, general school, and general self-concept. The results are consistent with expectations associating biculturalism with high self-concept.
A Cross-Sectional Study of Onset, Cessation, Frequency, and Duration of Children's Temper Tantrums in a Nonclinical Sample
Authors: Österman Karin , Björkqvist Kaj
Published: May 2010

Temper tantrums among young children were investigated with the questionnaire Parents' Experiences of Temper Tantrums in Children. Parents of 132 children (101 mothers, 31 fathers) in a largely Swedish-speaking area of Finland completed the questionnaire. 87% of the parents reported that one or more of their children had had temper tantrums. Of all children in the study, 64.7% began having tantrums when they were 2 or 3 years old; 57.1% did not have tantrums anymore after age five. For 46.5% of the cases, the tantrums lasted between 5 and 10 minutes. There was no sex difference for age of onset of tantrums, age when tantrums ceased, age span during which they occurred, frequency, or duration of episodes.
Reliability and Validity of the Self-Report Family Content Scale
Authors: Samani S. , Sadeghzadeh M.
Published: May 2010

The aim of the study was to assess the reliability and validity of Self-report Family Content Scale for measurement of a contextual and psycho…educational model for family studies. The sample included 450 college students at Shiraz University (241 women, 209 men; M age = 27.5 yr., SD = 3.8). Principal-components factor analysis indicated a 7-factor solution. The mean correlations among factors and between factors and the total score of the scale were .18 and .42, respectively. Coefficients alpha indicated good reliability and internal consistency for the scale.
Intergenerational Differences in Mental Boundaries
Authors: Barbuto John E. , Bryant Stephanie , Pennisi Lisa A.
Published: May 2010

382 employees in government offices were surveyed using demographic variables and organizational and interpersonal boundaries. Analysis of variance indicated a significant difference in Mental Boundary Score between Baby Boomers I (born 1946–1954) and Generation X (born 1965–1976) cohorts.
Effects of Daylight Savings Time Changes on Stock Market Volatility
Authors: Berument M. Hakan , Dogan Nukhet , Onar Bahar
Published: May 2010

The presence of daylight savings time effects on stock returns and on stock volatility was investigated using an EGARCH specification to model the conditional variance. The evidence gathered from the major United States stock markets for the period between 1967 and 2007 did not support the existence of the daylight savings time effect on stock returns or on volatility. Returns on the first business day following daylight savings time changes were not lower nor was the volatility higher, as would be expected if there were an effect.
Electric dipole strength distribution below the E1 giant resonance in N = 82 nuclei
Authors: Guliyev Ekber , Kuliev Ali , Guner Mehmet
Published: May 2010

In this study quasiparticle random-phase approximation with the translational invariant Hamiltonian using deformed mean field potential has been conducted to describe electric dipole excitations in 136Xe, 138Ba, 140Ce, 142Nd, 144Sm and 146Gd isotones. The distribution of the calculated E1 strength shows a resonance like structure at energies between 6–8 MeV exhausting up to 1% of the isovector electric dipole Energy Weighted Sum Rule and in some aspects nicely confirms the experimental data. It has been shown that the main part of E1 strength, observed below the threshold in these nuclei may be interpreted as main fragments of the Pygmy Dipole resonance. The agreement between calculated mean excitation energies as well as summed B(E1) value of the 1− excitations and the available experimental data is quite good. The calculations indicate the presence of a few prominent positive parity 1+ States in heavy N = 82 isotones in the energy interval 6–8 MeV which shows not all dipole excitations were of electric character in this energy range.
Seasonal fluctuations of the nematode communities in a hop garden soil
Authors: Renčo M. , Lišková M. , Čerevková A.
Published: May 2010

A study on the seasonal fluctuation of nematode population was conducted during three vegetation periods (2005 – 2007), at 20 and 40 cm soil depth, from May to October, in a hop garden at Nemšová (Slovak Republic). The seasonal fluctuation of the nematode population was related to temperature and rainfall. At 20 cm soil depth of each year, the largest nematode population was recorded in July, and the smallest from July to October. At 40 cm soil depth, nematode abundance was not significantly different between the years 2006 and 2007. In general, at the same depth, a decrease of nematode abundance was observed from May to October. The soil nematode community was rich in bacteriovorous nematodes, especially in the top 20 cm soil. The genus Rhabditis was the eudominant taxon at both soil depths. This genus with the genera Cephalobus, Heterodera, Merlinius and Aglenchus represented the 50 % of the total nematode population at 20 cm soil depth and with the genera Cephalobus, Helicotylenchus, Heterodera and Merlinius represented the 52 % of total nematodes abundance at 40 cm depth.
Application of Novel Inertial Technique to Compare the Kinematics and Kinetics of the Legs in the Soccer Instep Kick
Authors: Meamarbashi Abbas , Hossaini S.
Published: May 2010

Application of Novel Inertial Technique to Compare the Kinematics and Kinetics of the Legs in the Soccer Instep Kick

The kinematic and kinetic parameters of dominant and non-dominant legs examined with a new technology on 15 male, university soccer players in the field. A sensor module with special configuration of accelerometers placement, connected to a data logger, which attached to the shank and thigh, was applied to execute four instep kicks in the field. The angular velocity, linear velocity, angular acceleration and Z-axis linear acceleration (p<0.005) of the shank in dominant and non-dominant leg before impact were: 1970 ± 210, 1648 ± 300 °/s; 14.9 ± 3.0, 12.4 ± 2.6 m/s; 586.4 ± 121.9, 498.2 ± 160.4 rad/s2; 5.7 ± 1.7 and 4.0 ± 0.9 gravity, respectively. The leg swing time, force (X) (p<0.001), torque, angular momentum, angular power and angular impulse (p<0.05) of the shank, for dominant and non-dominant leg, before impact were: 271 ± 48 vs. 263 ± 62 msec; 172.4 ± 46.6 vs. 68.7 ± 47.1 N; 133.2 ± 29.8 vs. 111.8 ± 34.9 N.m.; 5.3 ± 1.1 vs. 4.1 ± 1.0 kg.m2/s; 2443 ± 666 vs. 1660 ± 790.1 W; 4.0 ± 0.9 vs. 3.3 ± 1.2 N.s., respectively. Even though there was lower shank angular velocity of the dominant leg compared with reported professional players, similar shape and gradient of the kicking pattern were found in the curves.
Physiological Background of Muscular Pain During Skiing and Delayed Muscle Soreness after Skiing
Authors: Klimek Andrzej
Published: May 2010

Physiological Background of Muscular Pain During Skiing and Delayed Muscle Soreness after Skiing

During intensive skiing, at each turn, in particular towards the end of the turning steering phase, eccentric work of the lower limb muscles occurs (predominantly of the quadriceps femoris), which is the direct cause of damage within muscle cells. A few or more than ten hours after intensive physical effort the symptoms of delayed onset muscle soreness may appear, which is mainly a result of the micro-damage within the myocytes.

The following procedure can be proposed for prevention of muscle soreness for skiers: around a week before first day of skiing in the season, skiers should perform a series of intensive physical exercises involving eccentric contractions, thus inducing delayed muscular soreness. The exercises may involve for example: downhill running, preferably down a steep slope, running down stairs, deep knee bend jumps, deep knee bend jumps over an obstacle, jumping to the ground from a certain height, sit-ups on one or both feet, etc. The exercises should lead considerable local fatigue, in particular of the lower limb muscles, so that muscle soreness occurs on the second day, in particular in the frontal part of the thighs. After approximately two days the pain will alleviate, while after a week the strength of the muscles will return to its pre-exercise condition. This should considerably reduce, or even remove, delayed muscle soreness after skiing, which will not only help skiers use their time more effectively but will also be crucial to the skiers' safety.
Localization of cervical and cervicomedullary stimulation leads for pain treatment using median nerve somatosensory evoked potential collision testing
Authors: Balzer Jeffrey R. , Tomycz Nestor D. , Crammond Donald J. , Habeych Miguel , Thirumala Parthasarathy D. , Urgo Louisa , Moossy John J.
Published: May 2010

Object

Spinal cord stimulation (SCS) is being currently used to treat medically refractory pain syndromes involving the face, trunk, and extremities. Unlike thoracic SCS surgery, during which patients can be awakened from conscious sedation to confirm good lead placement, safe placement of paddle leads in the cervical spine has required general anesthesia. Using intraoperative neurophysiological monitoring, which is routinely performed during these cases at the authors' institution, the authors developed an electrophysiological technique to intraoperatively lateralize lead placement in the cervical epidural space.

Methods

Data from 44 patients undergoing median and tibial nerve somatosensory evoked potential (SSEP) monitoring during cervical laminectomy or hemilaminectomy for placement or replacement of dorsal column stimulators were retrospectively reviewed. Paddle leads were positioned laterally or just off midline and parallel to the axis of the cervical spinal cord to effectively treat what was most commonly a predominant unilateral pain syndrome. During SSEP recording, the spinal cord stimulator was activated at 1.0 V and increased in increments of 1.0 V to a maximum of 6.0 V. A unilateral reduction or abolishment of SSEP amplitude was regarded as an indicator of lateralized placement of the stimulator. A bilateral diminutive effect on SSEPs was interpreted as a midline or near midline lead placement.

Results

Epidural stimulation abolished or significantly reduced SSEP amplitudes in all patients undergoing placement for a unilateral pain syndrome. In 15 patients, electrodes were repositioned intraoperatively to achieve the most robust SSEP amplitude reduction or abolishment using the lowest epidural stimulation intensity. In all cases in which a significant unilateral reduction in SSEP was observed, the patient reported postoperative sensory alterations in target locations predicted by intraoperative SSEP changes. Placement of cervical spinal cord stimulators for bilateral pain syndromes often resulted in bilateral but asymmetrical SSEP changes. In no cases were significant SSEP changes, other than those induced using the device to directly stimulate the dorsal surface of the spinal cord, observed. No case of new postoperative neurological deficit was observed.

Conclusions

Somatosensory evoked potentials can be used safely and successfully for predicting the lateralization of cervical spinal cord stimulator placement. Moreover, they can also intraoperatively alert the surgical team to inadvertent displacement of a lead during anchoring. Further studies are needed to determine whether apart from assisting with proper lateralization, SSEP collision testing may help to optimize electrode positioning and improve pain control outcomes.
Rathke cleft cyst apoplexy: a newly characterized distinct clinical entity
Authors: Chaiban Joumana T. , Abdelmannan Dima , Cohen Mark , Selman Warren R. , Arafah Baha M.
Published: May 2010

Object

Although most Rathke cleft cysts (RCCs) remain asymptomatic, some present with compression of surrounding structures and pituitary hormone dysfunction. A rare, but distinct presentation of the RCC includes hemorrhage into the cyst—a presentation that mimics the clinical syndrome of pituitary tumor apoplexy. The objective of this article is to present the authors' experience on the prevalence and the clinical, biochemical, pathological, and imaging characteristics of hemorrhage into an RCC and review published reports on this entity.

Methods

An institutional database for patients with pituitary masses was reviewed and data on cases involving surgery for a subsequently documented RCC were identified. Patients with documented hemorrhage within the RCC were included in the analysis. Documentation included intraoperative visualization of hemorrhage by the surgeon and/or pathological confirmation of hemorrhage within the RCC. The clinical, biochemical, pathological, and imaging characteristics of these patients were extracted from the database. All published data on RCC were also reviewed and confirmed cases of hemorrhage were extracted and included in the review.

Results

A total of 11 cases with hemorrhage within an RCC were identified to have been managed at the authors' institution over a 10-year span. This figure represented 20% of all surgically treated cases of RCC from that period. Among published reports, a total of 10 confirmed cases were evaluated. The clinical presentation of patients with hemorrhage within an RCC are classical and include sudden onset of severe headache—or a sudden increase in headache severity—associated with visual disturbances, impairment in pituitary function, and occasionally alterations in mental status. Leakage of the cystic contents into the subarachnoid space can occur rarely and may lead to associated chemical meningitis. There are no known precipitating factors for this phenomenon. The clinical presentation of such patients is difficult to distinguish from that of patients with pituitary tumor apoplexy. However, patients with RCC apoplexy often present with less severe symptoms, have a lower prevalence of pituitary dysfunction, and generally have smaller mass lesions than those with pituitary tumor apoplexy. Management of patients with RCC apoplexy is similar to that of those with pituitary tumor apoplexy. Surgery can provide definitive diagnosis and relief of symptoms and often leads to recovery from hypopituitarism. All patients with this syndrome require long-term follow-up to treat any residual sequelae.

Conclusions

This article provides the first thorough review and characterization of patients with hemorrhage within an RCC. Based on the clinical manifestations of this presentation, we recommend using the term “Rathke cleft cyst apoplexy” to describe the syndrome.
Effect of an External Oriented Magnetic Field on Entropy Generation in Natural Convection
Authors: El Jery Atef , Hidouri Nejib , Magherbi Mourad , Brahim Ammar Ben
Published: May 2010

The influence of an external oriented magnetic field on entropy generation in natural convection for air and liquid gallium is numerically studied in steady-unsteady states by solving the mass, the momentum and the energy conservation equations. Entropy generation depends on five parameters which are: the Prandtl number, the irreversibility coefficients, the inclination angle of the magnetic field, the thermal Grashof and the Hartmann numbers. Effects of these parameters on total and local irreversibilities as well as on heat transfer and fluid flow are studied. It was found that the magnetic field tends to decrease the convection currents, the heat transfer and entropy generation inside the enclosure. Influence of inclination angle of the magnetic field on local irreversibility is then studied.
Bioadhesive Controlled Metronidazole Release Matrix Based on Chitosan and Xanthan Gum
Authors: Eftaiha Ala’a F. , Qinna Nidal , Rashid Iyad S. , Al Remawi Mayyas M. , Al Shami Munther R. , Arafat Tawfiq A. , Badwan Adnan A.
Published: May 2010

Metronidazole, a common antibacterial drug, was incorporated into a hydrophilic polymer matrix composed of chitosan xanthan gum mixture. Hydrogel formation of this binary chitosan-xanthan gum combination was tested for its ability to control the release of metronidazole as a drug model. This preparation (MZ-CR) was characterized by in vitro, ex vivo bioadhesion and in vivo bioavailability study. For comparison purposes a commercial extended release formulation of metronidazole (CMZ) was used as a reference. The in vitro drug-release profiles of metronidazole preparation and CMZ were similar in 0.1 M HCl and phosphate buffer pH 6.8. Moreover, metronidazole preparation and CMZ showed a similar detachment force to sheep stomach mucosa, while the bioadhesion of the metronidazole preparation was higher three times than CMZ to sheep duodenum. The results of in vivo study indicated that the absorption of metronidazole from the preparation was faster than that of CMZ. Also, MZ-CR leads to higher metronidazole Cmax and AUC relative to that of the CMZ. This increase in bioavailability might be explained by the bioadhesion of the preparation at the upper part of the small intestine that could result in an increase in the overall intestinal transit time. As a conclusion, formulating chitosan-xanthan gum mixture as a hydrophilic polymer matrix resulted in a superior pharmacokinetic parameters translated by better rate and extent of absorption of metronidazole.
Beyond Genetics—Stratified and Personalised Medicines Using Multiple Parameters
Authors: Peck Richard , Smith Patrick
Published: May 2010

Prescribers have been practicing stratified medicine for many years. Patient characteristics, usually non-genetic, including age, comorbidities and concomitant medications are taken into account when deciding which drug to prescribe. In addition, the majority of drugs require dose adjustments across patient subgroups, usually determined by non-genetic differences between the subgroups. Whilst pharmacogenetics hold promise for enhancing treatment stratification and even treatment individualisation, non-genetic factors will continue to be very important. Both non-genetic and genetic factors must be considered to improve understanding and quantification of the variability in treatment outcomes and to guide stratification and targeting of patient subgroups to the right drug and also to the right range of doses within that subgroup. Development of stratified medicines must consider non-genetic as well as genetic factors and, where appropriate, include stratification through optimising the dose for each patient or subgroup as well as by choosing the drug most likely to deliver efficacy to that patient or group.
The Role of Configurational Entropy in Amorphous Systems
Authors: Graeser Kirsten A. , Patterson James E. , Zeitler J. Axel , Rades Thomas
Published: May 2010

Configurational entropy is an important parameter in amorphous systems. It is involved in the thermodynamic considerations, plays an important role in the molecular mobility calculations through its appearance in the Adam-Gibbs equation and provides information on the solubility increase of an amorphous form compared to its crystalline counterpart. This paper presents a calorimetric method which enables the scientist to quickly determine the values for the configurational entropy at any temperature and obtain the maximum of information from these measurements.
Characterization of Mixed xWO3(1-x)Y2O3 Nanoparticle Thick Film for Gas Sensing Application
Authors: Abadi M. H. Shahrokh , Hamidon M. N. , Shaari Abdul Halim , Abdullah Norhafizah , Misron Norhisam , Wagiran Rahman
Published: May 2010

Microstructural, topology, inner morphology, and gas-sensitivity of mixed xWO3(1-x)Y2O3 nanoparticles (x = 1, 0.95, 0.9, 0.85, 0.8) thick-film semiconductor gas sensors were studied. The surface topography and inner morphological properties of the mixed powder and sensing film were characterized with X-ray diffraction (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Also, gas sensitivity properties of the printed films were evaluated in the presence of methane (CH4) and butane (C4H10) at up to 500 °C operating temperature of the sensor. The results show that the doping agent can modify some structural properties and gas sensitivity of the mixed powder.
Symmetry OUT, Asymmetry IN
Authors: Lourenço Raquel , Saúde Leonor
Published: May 2010

The formation of a perfect vertebrate body plan poses many questions that thrill developmental biologists. Special attention has been given to the symmetric segmental patterning that allows the formation of the vertebrae and skeletal muscles. These segmented structures derive from bilaterally symmetric units called somites, which are formed under the control of a segmentation clock. At the same time that these symmetric units are being formed, asymmetric signals are establishing laterality in nearby embryonic tissues, allowing the asymmetric placement of the internal organs. More recently, a “shield” that protects symmetric segmentation from the influence of laterality cues was uncovered. Here we review the mechanisms that control symmetric versus asymmetric development along the left-right axis among vertebrates. We also discuss the impact that these studies might have in the understanding of human congenital disorders characterized by congenital vertebral malformations and abnormal laterality phenotypes.
HIV-1 Virological Synapse is not Simply a Copycat of the Immunological Synapse
Authors: Vasiliver-Shamis Gaia , Dustin Michael , Hioe Catarina
Published: May 2010

The virological synapse (VS) is a tight adhesive junction between an HIV-infected cell and an uninfected target cell, across which virus can be efficiently transferred from cell to cell in the absence of cell-cell fusion. The VS has been postulated to resemble, in its morphology, the well-studied immunological synapse (IS). This review article discusses the structural similarities between IS and VS and the shared T cell receptor (TCR) signaling components that are found in the VS. However, the IS and the VS display distinct kinetics in disassembly and intracellular signaling events, possibly leading to different biological outcomes. Hence, HIV-1 exploits molecular components of IS and TCR signaling machinery to trigger unique changes in cellular morphology, migration, and activation that facilitate its transmission and cell-to-cell spread.
Best Fit and Selection of Theoretical Flood Frequency Distributions Based on Different Runoff Generation Mechanisms
Authors: Iacobellis Vito , Fiorentino Mauro , Gioia Andrea , Manfreda Salvatore
Published: May 2010

Theoretically derived distributions allow the detection of dominant runoff generation mechanisms as key signatures of hydrologic similarity. We used two theoretically derived distributions of flood peak annual maxima: the first is the “IF” distribution, which exploits the variable source area concept, coupled with a runoff threshold having scaling properties; the second is the Two Component-IF (TCIF) distribution, which generalizes the IF distribution, and is based on two different threshold mechanisms, associated with ordinary and extraordinary events, respectively. By focusing on the application of both models to two river basins, of sub-humid and semi-arid climate in Southern Italy, we present an ad hoc procedure for the estimation of parameters and we discuss the use of appropriate techniques for model selection, in the case of nested distributions.
Clonal resistance analyses of HIV type-1 after failure of therapy with didanosine, lamivudine and tenofovir
Authors: Barnas Douglas , Koontz Dianna , Bazmi Holly , Bixby Christian , Jemsek Joseph , Mellors John W
Published: May 2010

Background

The rapid failure of initial therapy with combinations of nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) that exclude zidovudine has not been fully explained by standard virus population analyses of HIV type-1 (HIV-1) drug resistance. We therefore investigated HIV-1 genotype and phenotype at the single genome level in samples from patients on a failing regimen of tenofovir (TNV), didanosine (ddI) and lamivudine (3TC).

Methods

Single genome sequencing was performed on 9 failure samples containing both K65R and M184V mutations by standard genotype, either as wild-type/mutant mixtures (6/9) or as mutant only (3/9). Recombinant clones with different combinations of observed mutations were generated and tested for NRTI susceptibility.

Results

Of the 204 single genome sequences analysed, 50% were K65R/M184V double mutants, 38% were M184V single mutants, 10% were M184I single mutants and only 1% (2 sequences) were K65R single mutants. Phenotypic testing of recombinant clones showed a significant increase in resistance for double mutants: mean fold resistance to abacavir, ddI and TNV was 6.5, 4.3 and 1.6 for K65R/M184V double mutants versus 2.5, 1.9 and 0.6 for M184V single mutants, respectively ( P<0.001).

Conclusions

Mutants with K65R and M184V linked on the same genome were the most common HIV-1 variants in samples analysed from patients failing TNV, ddI and 3TC with both mutations detected by standard genotype. The double mutant exhibited reduced susceptibility to all three NRTIs in the regimen. This resistant phenotype, resulting from just two linked point mutations, likely contributes to rapid failure of NRTI combinations that exclude zidovudine.
Evaluation of the in vitro anti-HBV activity of clevudine in combination with other nucleoside/ nucleotide inhibitors
Authors: Niu Congrong , Bao Haiying , Tolstykh Tatiana , Steuer Holly M Micolochick , Murakami Eisuke , Korba Brent , Furman Phillip A
Published: May 2010

Background

To reduce the incidence of drug resistance and to maintain viral suppression, patients chronically infected with HBV might require combination therapy using two or more drugs with different resistance pro-files. We investigated the activity of clevudine (CLV) in combination with other nucleoside/nucleotide analogues to determine if these combinations were compatible in vitro.

Methods

Using the HepAD38 cell line, which expresses wild-type HBV, and a real-time PCR assay, we tested the anti-HBV activity of CLV in combination with entecavir, lamivudine, adefovir, tenofovir and telbivudine (TBV). We evaluated the uptake and phosphorylation of CLV in the presence of TBV, using HepAD38 cells and primary hepatocytes to determine the effect of TBV on the phosphorylation of CLV and vice versa. Phosphorylation of TBV and CLV to their corresponding monophosphate by deoxycytidine kinase, thymidine kinase-1 and thymidine kinase-2, and the phosphorylation of TBV monophosphate and CLV monophosphate by thymidylate kinase was evaluated and compared.

Results

When CLV was combined with entecavir, lamivudine, adefovir or tenofovir, a synergistic antiviral effect was observed; however, the combination of CLV and TBV gave an antagonistic antiviral response. The results of in vitro metabolism and enzyme studies suggest that the antagonism observed with the CLV/TBV combination involves competition for uptake and phosphorylation.

Conclusions

The results of our studies demonstrate that combination treatments can provide enhanced antiviral activity and, when used in conjunction with appropriate metabolic investigations, provide a rational basis for the design and development of combination regimens for treating chronic HBV infection.
CD4+ T-cell-guided structured treatment interruptions of antiretroviral therapy in HIV disease: Projecting beyond clinical trials
Authors:   CEPAC-International Investigators, Yazdanpanah Yazdan , Wolf Lindsey L , Anglaret Xavier , Gabillard Delphine , Walensky Rochelle P , Moh Raoul , Danel Christine , Sloan Caroline E , Losina Elena , Freedberg Kenneth A
Published: May 2010

Background

International trials have shown that CD4+ T-cell-guided structured treatment interruptions (STI) of antiretroviral therapy (ART) lead to worse outcomes than continuous treatment. We simulated continuous ART and STI strategies with higher CD4+ T-cell interruption/reintroduction thresholds than those assessed in actual trials.

Methods

Using a model of HIV, we simulated cohorts of African adults with different baseline CD4+ T-cell counts (≤200; 201-350; and 351-500 cells/μl). We varied ART initiation criteria (immediate; CD4+ T-cell count <350 cells/μl or ≥350 cells/μl with severe HIV-related disease; and CD4+ T-cell count <200 cells/μl or ≥200 cells/μl with severe HIV- related disease), and ART interruption/reintroduction thresholds (350/250; 500/350; and 700/500 cells/μl). First-line therapy was non- nucleoside reverse transcriptase inhibitor (NNRTI)-based and second-line therapy was protease inhibitor (PI)-based.

Results

STI generally reduced life expectancy compared with continuous ART. Life expectancy increased with earlier ART initiation and higher interruption/reintroduction thresholds. STI reduced life expectancy by 48–69 and 11–30 months compared with continuous ART when interruption/reintroduction thresholds were 350/250 and 500/350 cells/μl, depending on ART initiation criteria. When patients interrupted/reintroduced ART at 700/500 cells/μl, life expectancies ranged from 2 months lower to 1 month higher than continuous ART. STI-related life expectancy increased with decreased risk of virological resistance after ART interruptions.

Conclusions

STI with NNRTI-based regimens was almost always less effective than continuous treatment, regardless of interruption/reintroduction thresholds. The risks associated with STI decrease only if patients start ART earlier, interrupt/reintroduce treatment at very high CD4+ T-cell thresholds (700/500 cells/μl) and use first-line medications with higher resistance barriers, such as PIs.
Genotypic and phenotypic evolution of HIV type-1 protease during in vitro sequential or concomitant combination of atazanavir and amprenavir
Authors: Cunyat Francesc , Ruiz Lidia , Marfil Silvia , Puig Teresa , Bofill Margarita , Blanco Julià , Clotet Bonaventura , Cabrera Cecilia
Published: May 2010

Background

The pathways of resistance to atazanavir (ATV) and amprenavir (APV) converge at position 50 of HIV protease. The determinants of cross-resistance were analysed during in vitro sequential or concomitant combination pressure with both drugs.

Methods

Recombinant viruses containing in vitro and in vivo selected I50L and I50V proteases were constructed and cultured in increasing concentrations of APV or ATV, respectively. In addition, in vitro resistance to ATV plus APV was performed. All the resistant viruses obtained were genotyped and phenotyped.

Results

ATV or APV alone selected I50L- or I50V-containing variants. Subsequent addition of ATV to I50V-containing recombinant viruses led to the reversion of this change and the later selection of I50L. By contrast, addition of APV to I50L-containing recombinant viruses was not associated with reversion. The combined pressure with ATV plus APV selected several changes but not at position 50. Phenotypically, both sequential and concomitant ATV–APV pressure yielded viruses resistant to all the drugs tested, although the emergence of I50L by ATV pressure on APV-resistant variants was associated with a reduced resistance to APV and darunavir.

Conclusions

All drug combinations led to APV plus ATV cross-resistance. The different pathways select for isoleucine or leucine at position 50, whereas the I50V mutation was excluded. Sequential pressure with ATV might have an advantage in terms of modulating the sensitivity of HIV to other protease inhibitors.
Can Person-Centered Technology Enhanced Learning Contribute to Develop Project Management Soft Skills in an Academic Context?
Authors: Motschnig-Pitrik Renate , Derntl Michael
Published: May 2010

In the preceding years we employed active technology enhanced learning in a course on project management soft skills that was particularly well received by students. This chapter presents the underlying philosophy, the current course design, students’ reactions, and our experiences and lessons learned. Concurrently, we confirm the applicability of participatory action research as a methodological framework suited for improving course design, specific interventions, and theory building. We propose to complement that framework by qualitative and quantitative methods in order to deal with specific research questions. Results indicate that students consider their active involvement in the course, both face-to face and online, the top factor from which they benefit. Furthermore, the majority of students felt that it was easier for them to work in teams and to establish social relationships. The primary goal of the chapter is to provide a pool of inspiration for other educators in practice and research.
Information Technology Portfolio Management
Authors: Syrris Vassilis
Published: May 2010

This study involves the exploration of Information Technology Portfolio Management (ITPM) in conjecture with Modern Portfolio Theory (MPT). The ITPM constitutes an indispensable part of the Strategic Information System which is an integrated multi-functional structure having its origin in works of Anthony (1965) and Gibson & Nolan (1974). ITPM attempts to resolve the project selection problem concerning the majority of project-centric organizations. Roughly speaking, projects must compete for the scarce resources which are only available for the fittest ones. Although a large proportion of portfolio selection decisions are taken on a qualitative basis, quantitative approaches to selection such as MPT or its variants are beginning to gain wide application. Yet, the standard MPT has proved incapable of representing the complexities of real-world situations. This issue generates the present work which focuses on the project portfolio optimization problem through a meta-heuristic approach, that is, application of algorithmic methods able to find near-optimal solutions in a reasonable amount of computation time. The ultimate goal is the enhancement of IT portfolio management which has become a significant factor in the planning and operation of information-based organizations, thus, offering a competitive advantage.
A Bio-Psycho-Social Review of Usability Methods and their Applications in Healthcare
Authors: Price Morgan
Published: May 2010

The purpose of this chapter is to provide the reader with an overview of several models and theories from the general HCI literature, highlighting models at three levels of focus: biomechanical interactions, individual-cognitive interactions, and social interactions. This chapter will also explore how these models were or could be applied to the design and evaluation of clinical information systems, such as electronic medical records and hospital information systems. Finally, it will conclude with how an understanding at each level compliments the other two in order to create a more complete understanding of the interactions of information systems in healthcare.
Towards Computer Supported Clinical Activity
Authors: Nøhr Christian , Boye Niels
Published: May 2010

The introduction of electronic health records (EHRs) to the clinical setting has led healthcare professionals, policy makers, and administrators to believe that health information systems will improve the functioning of the healthcare system. In general, such expectations of health information system functionality, impact, and ability to disseminate have not been met. In this chapter the authors present the findings of three empirical studies: (1) the structured monitoring of EHR implementation processes in Denmark from 1999–2006 by the Danish EHR observatory, (2) a usability study based on human factors engineering concepts with clinicians in artificial but realistic circumstances—a “state of the art (2005)” for Danish CPOE (computerized physician order entry system), and (3) user reactions to a conceptual “high level model” of healthcare activities—the Danish G-EPJ model in order to better understand the reasons for health information system failures and to suggest methods of improving adoption. The authors suggest that knowledge handling as a science seems immature and is not in line with the nature of clinical work. The prerequisites for mature knowledge handling are discussed in the second part of this chapter. More specifically, the authors describe one way of improving knowledge handling: the development of a more true digital representation of the object of interest (OOI) or the virtual patient/citizen that interacts with computer based healthcare services on behalf of and for the benefit of the citizen’s health.
Pervasive Healthcare
Authors: Boye Niels
Published: May 2010

Pervasive healthcare is a vision for the future of healthcare. Healthcare provisions can be delivered with high quality at low cost along with higher patient-experienced quality and satisfaction as a service on top of a pervasive computing infrastructure, which can be built by integrating communicating computerpower into industrial products and fixed structures in urban and rural spaces. For pervasive healthcare, integration with on body networks sensors and actuators may also be needed. This chapter discusses the prerequisites of this vision from a point of a healthcare professional. A number of parallel advances in concepts have to take place before pervasive healthcare (PH) is matured into a general method for delivering healthcare provisions. The contemporary, most widespread model of healthcare provisions as industrial products with consumer-goods characteristics has to mature into the concepts of welfare economics. New market models have to be developed for PH to pervade society and add value to the health aspects of an individual’s life. Ethical and legal aspects must also be further matured. Maturation of technology is needed. This includes all the components of the “pervasive loop” from sensors to the central intelligence back to the actuators. The “virtual patient/healthy human” as an operational digital representation of the “object/subject of care” also has to be developed. Pervasive healthcare (or the European Union term: ambient assisted living) is a promising field, that has potential to integrate health considerations and health promoting activities for patients and non-patients in their everyday conduct and provide added value to life quality for individuals.
Best Practices for Implementing Electronic Health Records and Information Systems
Authors: Kucukyazici Beste , Keshavjee Karim , Bosomworth John , Copen John , Lai James
Published: May 2010

This chapter introduces a multi-level, multi-dimensional meta-framework for successful implementations of EHR in healthcare organizations. Existing implementation frameworks do not explain many features experienced and reported by implementers and have not helped to make health information technology implementation any more successful. To close this gap, we have developed an EHR implementation framework that integrates multiple conceptual frameworks in an overarching, yet pragmatic meta-framework to explain factors which lead to successful EHR implementation, in order to provide more quantitative insight into EHR implementations. Our meta-framework captures the dynamic nature of an EHR implementation through their function, interactivity with other factors and phases, and iterative nature.