bluuebunny/crossref_metadata_2025 huggingface dataset:
Atomistic molecular dynamics simulation of the temperature and pressure dependences of local and terminal relaxations in cis-1,4-polybutadiene
Authors: Tsolou Georgia , Harmandaris Vagelis A. , Mavrantzas Vlasis G.
Published: February 2006

The dynamics of cis-1,4-polybutadiene (cis-1,4-PB) over a wide range of temperature and pressure conditions is explored by conducting atomistic molecular dynamics (MD) simulations with a united atom model on a 32-chain C128 cis-1,4-PB system. The local or segmental dynamics is analyzed in terms of the dipole moment time autocorrelation function (DACF) of the simulated polymer and its temperature and pressure variations, for temperatures as low as 195 K and pressures as high as 3 kbars. By Fourier transforming the DACF, the dielectric spectrum, ε*=ε′+iε″=ε*(ω), is computed and the normalized ε″∕εmax″vsω∕ωmax plot is analyzed on the basis of the time-temperature and time-pressure superposition principles. The relative contribution of thermal energy and volume to the segmental and chain relaxation processes are also calculated and evaluated in terms of the ratio of the activation energy at constant volume to the activation energy at constant pressure, QV∕QP. Additional results for the temperature and pressure dependences of the Rouse times describing terminal relaxation in the two polymers show that, in the regime of the temperature and pressure conditions covered here, segmental and chain relaxations are influenced similarly by the pressure and temperature variations. This is in contrast to what is measured experimentally [see, e.g., G. Floudas and T. Reisinger, J. Chem. Phys. 111, 5201 (1999); C. M. Roland et al.,J. Polym. Sci. Part B, 41, 3047 (2003)] for other, chemically more complex polymers that pressure has a stronger influence on the dynamics of segmental mode than on the dynamics of the longest normal mode, at least for the regime of temperature and pressure conditions covered in the present MD simulations.
Whispering-gallery-modelike-enhanced emission from ZnO nanodisk
Authors: Kim Chinkyo , Kim Yong-Jin , Jang Eue-Soon , Yi Gyu-Chul , Kim Hyun Ha
Published: February 2006

Hexagonal nanodisks of ZnO were fabricated by a solution process using ZnO nanoparticles and their cathodoluminescence characteristics were investigated. Monochromatic cathodoluminescence images showed that luminescence was spatially localized near the boundary of the nanodisk and spectral analysis in conjunction with the intensity profile consistently ascribed the spatial localization of luminescence to whispering-gallery-modelike-enhanced emission.
Suppression of crack generation in GaN epitaxy on Si using cubic SiC as intermediate layers
Authors: Komiyama Jun , Abe Yoshihisa , Suzuki Shunichi , Nakanishi Hideo
Published: February 2006

We demonstrate suppression of crack generation in GaN epitaxy on Si using cubic SiC as intermediate layers. Crack-free GaN with a thickness of 2μm was obtained. Epilayers of SiC (0–1μm), thin AlN (50nm), and GaN (1–3μm) were prepared on 3in. (111)Si substrates (GaN∕AlN∕SiC∕Si) by metalorganic vapor-phase epitaxy. Cracking of GaN is suppressed with thicker SiC (1μm), whereas cracks are generated in GaN without SiC and with thinner SiC (50nm). Transmission electron microscopy analysis revealed monocrystalline wurzite structure of GaN. Current-voltage measurements showed breakdown voltage exceeding 250V, indicating its potential for high voltage application.
Orbital-corrected orbital-free density functional theory
Authors: Zhou Baojing , Wang Yan Alexander
Published: February 2006

A new implementation of density functional theory (DFT), namely orbital-corrected orbital-free (OO) DFT, has been developed. With at most two non-self-consistent iterations, OO-DFT accomplishes the accuracy comparable to fully self-consistent Kohn-Sham DFT as demonstrated by its application on the cubic-diamond Si and the face-centered-cubic Ag systems. Our work provides a new impetus to further improve orbital-free DFT method and presents a robust means to significantly lower the cost associated with general applications of linear-scaling Kohn-Sham DFT methods on large systems of thousands of atoms within different chemical bonding environment.
Generation of femtosecond optical vortices using a single refractive optical element
Authors: Moh K. J. , Yuan X.-C. , Tang D. Y. , Cheong W. C. , Zhang L. S. , Low D. K. Y. , Peng X. , Niu H. B. , Lin Z. Y.
Published: February 2006

It is shown experimentally for small spectral bandwidth that spiral phase plates (SPPs) can generate optical vortices in femtosecond beams without the need for additional dispersion compensation elements. An autocorrelation measurement performed on the obtained optical vortex (OV) beam showed that the SPP did not significantly change the pulse duration. Hence the single element SPP, already an established beam shaping technique in continuous wave and high power regimes, is presented as an efficient and practical means to obtain OVs that are free from spatial chirp in femtosecond beams.
Renner-Teller nonadiabatic coupling terms: An ab-initio study of the HNH molecule
Authors: Halász G. J. , Vibók Á. , Baer R. , Baer M.
Published: February 2006

In this Communication we present the first theoretical/numerical treatment of nonadiabatic coupling terms (NACT) that originate from the Renner-Teller (RT) model, namely, those that follow from the splitting of an electronic level of a linear molecule when it becomes bent. These two newly formed states are characterized by different symmetries and are designated as A and B. Our main findings: (1) The RT NACTs are quantized as long as they are calculated close enough to collinear configuration of the molecule (in this case HNH). Their value is τ=1 (the Jahn-Teller values in similar situations, are τ=1∕2). (2) Calculation of RT NACTs at bent configurations (i.e., at a distance from the linear axis) yield decreased values, sometimes by more than 50%. This last finding implies that in strongly bent configurations the two-state Hilbert subspace (formed by the above mentioned A and B states) is affected by upper states, most likely via Jahn-Teller conical intersections. (3) This study has also important practical implications. The fact that the RT NACTs decrease in (strongly) bent situations implies that analyzing spectroscopic data employing only the two Π-states may not be sufficient in order to achieve the required accuracy.
Feasibility study for thermal-field directed self-assembly of heteroepitaxial quantum dots
Authors: Friedman Lawrence H. , Xu Jian
Published: February 2006

Strain mismatched semiconductors are used to form self-assembled quantum dots (SAQDs). An important step in developing SAQD technology is to control randomness and disorder in SAQD arrays. There is usually both spatial and size disorder. Here, it is proposed to use spatially varying heating as a method of to direct self-assembly and create more ordered SAQD arrays or to control placement of single dots or dot clusters. The feasibility of this approach is demonstrated using a 2D computational model of Ge dots grown in Si based on finite element analysis of surface diffusion and linear elasticity.
Advanced perpendicular recording media structure with a magnetic intermediate layer
Authors: Piramanayagam S. N. , Zhao H. B. , Shi J. Z. , Mah C. S.
Published: February 2006

Co Cr Pt – Si O 2 perpendicular recording media containing a CoCr-based magnetic layer as an intermediate layer was studied. CoCr film deposited on a growth control layer such as Ta could grow with a hcp[0002] out-of-plane orientation, which could induce the desired perpendicular easy-axis orientation for the CoCrPt:SiO2 magnetic layer. It was observed that the growth of an intermediate layer based on Ru between the magnetic intermediate layer and the magnetic recording layer is crucial to reduce the noise. Recording performance of disks with a magnetic intermediate layer was comparable or better than that of conventional perpendicular media indicating the potential of the proposed structure.
Zinc oxide hexagram whiskers
Authors: Xu C. X. , Sun X. W. , Dong Z. L. , Zhu G. P. , Cui Y. P.
Published: February 2006

Through vapor-phase transport method, zinc oxide hexagram whiskers with uniform size and morphology were fabricated by heating a mixture source of zinc oxide, indium oxide, and graphite powders in air. Each whisker presented a hexagonal disk core closed by six equivalent surfaces of {101¯0} and was surrounded by side nanorods grown along the diagonal of the core disk in the 6-symmetric directions of ±[112¯0], ±[21¯1¯0], and ±[12¯10]. Based on the vapor-liquid-solid mechanism, the growth process of the zinc oxide hexagrams were discussed by considering the thermal dynamic properties of zinc oxide and indium oxide.
Functionalized carbon nanotubes in donor/acceptor-type photovoltaic devices
Authors: Pradhan Basudev , Batabyal Sudip K. , Pal Amlan J.
Published: February 2006

We have introduced functionalized multiwalled carbon nanotubes (CNTs) in donor/acceptor-type photovoltaic devices. We fabricated the devices based on heterostructure between polymer-CNT composite and buckminsterfullerene (C60) layers. Due to the functional groups of the CNTs, a homogeneous blend of CNT-polymer composite could be obtained. In the composite, the nanotubes acted as exciton dissociation sites and also hopping centers for hole transport. The CNTs in the polymer-CNT∕C60 device provided higher exciton dissociation volume and increased mobility for carrier transport. We have observed an increase in open-circuit voltage and short-circuit current in the polymer-CNT∕C60 devices as compared to the polymer∕C60 ones.
Blue-violet photoluminescence from amorphous Si-in-SiNx thin films with external quantum efficiency in percentages
Authors: Ma L. B. , Song R. , Miao Y. M. , Li C. R. , Wang Y. Q. , Cao Z. X.
Published: February 2006

Bright blue-violet photoluminescence centered at 428nm was obtained in amorphous Si-in-SiNx thin films prepared in a cyclic growth mode on cool substrates by plasma-enhanced chemical vapor deposition, in which the typical size of the silicon particles has been brought down to ∼1.80nm and the number density amounts to 1.07×1013cm2. A maximum external quantum efficiency over 3.0% was measured in the as-deposited samples. Time-resolved photoluminescence spectra revealed decay times within nanosecond even at room temperature, disclosing a fast recombination dynamics in this amorphous system. The excellent efficiency can be attributed to a better passivation of the silicon particles—hence, the conventional rapid thermal annealing has a negligible effect on the photoluminescence intensity—and also to an improved transparency of the film by cyclic growth. The high-efficiency, tunable wavelength and nanosecond decay time at room temperature, achieved via a low-temperature process without invoking any posttreatment, combine to make the Si-in-SiNx system a promising candidate for light-emitting nanostructures in photonic and optoelectronic applications.
Angular distribution control of extreme ultraviolet radiation from laser-produced plasma by manipulating the nanostructure of low-density SnO2 targets
Authors: Nagai Keiji , Gu QinCui , Gu ZhongZe , Okuno Tomoharu , Fujioka Shinsuke , Nishimura Hiroaki , Tao YeZheng , Yasuda Yuzuri , Nakai Mitsuo , Norimatsu Takayoshi , Shimada Yoshinori , Yamaura Michiteru , Yoshida Hidetsugu , Nakatsuka Masahiro , Miyanaga Noriaki , Nishihara Katsunobu , Izawa Yasukazu
Published: February 2006

We have found that the divergence of a relatively monochromatic extreme ultraviolet (EUV) emission from a laser-produced plasma can be manipulated by changing the target morphology which is a porous low-density tin oxide (SnO2) structure. The fundamental light of a Nd-YAG laser was irradiated on the target with laser intensity of ∼1011W∕cm2 and pulse duration of 10ns. The nanostructure and density of the targets were tuned by a combination of colloidal polymer template and sol-gel processes [Gu, Nagai, Norimatsu, Fujioka, Nishimura, Nishihara, Miyanaga, and Izawa, Chem. Mater. 17, 1115 (2005)], which has a merit in large-scale preparation. When the target has an open cell nanostructure, the EUV emission directed predominantly along target normal, while a closed cell target exhibited divergent emission. The angular distribution may be affected by the orientation of the microstructured initial target, and this phenomenon can be applied to wavefront control of EUV emission.
Can a N2-fixing Gluconacetobacter diazotrophicus association with sugarcane be achieved?
Authors: Walsh Kerry B. , Brown Sharon M. , Harrison Dion K.
Published: February 2006

Several published studies claim that high rates of N2 fixation occur in sugarcane and sorghum, and have ascribed this result to infection by the bacterium Gluconacetobacter diazotrophicus, abetted by arbuscular mycorrhizal infection (Glomus clarum). These results have not been confirmed within Australia. In this study, G. diazotrophicus was detected in stalks of field-grown sugarcane in Australia (based on phenotypic tests, and a PCR test using species-specific primers developed to amplify a fragment of the G. diazotrophicus 16S rRNA gene). Isolates were nitrogenase positive (acetylene reduction assay) in vitro. However, in glasshouse trials involving inoculation of sugarcane setts with G. diazotrophicus, co-inoculation with mycorrhizae, and plant growth under low N status, recovery of bacteria from maturing plants was variable. At 165 days from planting, no appreciable N2 fixation, as assessed by dry weight increment, N budget, or 15N ratio, of either an Australian or a Brazilian cultivar of sugarcane, or a sorghum cultivar, was achieved. We conclude that a N2-fixing sugarcane–G. diazotrophicus association is not easily achievable, being primarily limited by a lack of infection.
Responses of osmotic adjustment and seed yield of Brassica napus and B. juncea to soil water deficit at different growth stages
Authors: Ma Qifu , Niknam Sharon R. , Turner David W.
Published: February 2006

Canola (Brassica napus L.) is a major rotation crop but low yield has limited its adoption by farmers in the low-rainfall regions of southern Australia, where drought events can occur at any stage of crop development. We examined the effect of soil water deficit on osmotic adjustment and seed yield of canola and mustard (B. juncea L.) at the juvenile, elongation, anthesis, or seed-fill stage under glasshouse conditions and post-anthesis drought in the field. At the juvenile and elongation stages, leaves of both canola cv. Monty and mustard line 397-23-2-3-3 adjusted osmotically after exposure to water deficit. In comparison, only the mustard line expressed osmotic adjustment at anthesis and neither genotype adjusted at the seed-fill stage. A single drought event at the juvenile or elongation stage had little effect on growth and seed yield of either genotype, whereas water deficit at anthesis or seed-fill stage reduced seed yield of the canola cultivar by decreasing pod number, seeds per pod, and/or harvest index but largely did not affect the mustard line. In the field where rainfall diminished and plants were subjected to increasing water deficit during the reproductive stages, canola cv. Karoo and mustard line JN25 showed higher osmotic adjustment at anthesis and less yield reduction than the canola cv. Monty. This study suggests that yield sensitivity to water deficit was mainly due to its effect on concurrent formation of yield components, but could be modified by the physiological trait of osmotic adjustment.
Effect of defoliation interval on water-soluble carbohydrate and nitrogen energy reserves, regrowth of leaves and roots, and tiller number of cocksfoot (Dactylis glomerata L.) plants
Authors: Turner L. R. , Donaghy D. J. , Lane P. A. , Rawnsley R. P.
Published: February 2006

This study investigated the influence of leaf stage-based defoliation interval on water-soluble carbohydrate and nitrogen energy reserve status, regrowth of leaves and roots, and tiller number of cocksfoot (Dactylis glomerata L.) cv. Kara plants up to 24 days (3.5-leaf stage) following defoliation. Treatments were based on defoliation intervals of 1-, 2-, and 4-leaf stages of regrowth, with treatments terminated when the 1-leaf defoliation interval had been completed 4 times, the 2-leaf interval 2 times, and the 4-leaf interval once. Selected plants were destructively harvested prior to commencement of treatments (H0), immediately following cessation of treatments (H1), and at 5 days (H2), 10 days (H3), and 24 days (H4) following H1. Leaf, root, and tiller dry matter yield were determined at each harvest event, as well as tiller number/plant. Levels of water-soluble carbohydrate and nitrogen reserves in plant stubble and roots were determined at each destructive harvest. Initiation and death of daughter tillers were monitored from H0 to the completion of the study. More frequent defoliation of cocksfoot plants resulted in reduced water-soluble carbohydrate assimilation and therefore leaf, root, and tiller dry matter accumulation during the subsequent recovery period. Defoliation at the 1-leaf stage severely limited the regrowth potential of cocksfoot plants, whereas defoliation at the 2-leaf stage was adequate for plant recovery, but did not maximise regrowth. The results of this study showed that a defoliation interval based on the 4-leaf stage maximises water-soluble carbohydrate reserves, tillering, and leaf and root dry matter yields. The priority sequence for allocation of water-soluble carbohydrate reserves followed the order of leaf growth, root growth, and tillering during the regrowth period. Nitrogen energy reserves were found to play a minor role in the regrowth of cocksfoot plants following defoliation.
Differences in the distribution and seed germination behaviour of populations of Bromus rigidus and Bromus diandrus in South Australia: adaptations to habitat and implications for weed management
Authors: Kleemann S. G. L. , Gill G. S.
Published: February 2006

A field survey was undertaken in South Australia to determine the relative distribution of the brome grass species B. diandrus and B. rigidus. Seeds of brome grass plants were collected from locations across the Yorke (n = 10) and Eyre Peninsulas (n = 25). B. rigidus was found more frequently and at higher densities in South Australian crops than B. diandrus, which showed a distinct preference for undisturbed fence-line margins. Species identity of brome plants in each sample was initially determined by assessing morphology of the callus-scar of the caryopsis as well as the structure of the panicle. Species identity was later confirmed by counting somatic chromosome number. There was consistent agreement between the 2 approaches to identification, indicating that these morphological features can be used with confidence when identifying B. diandrus and B. rigidus in the field. Although B. diandrus and B. rigidus are morphologically very similar, they showed large differences in germination behaviour. B. diandrus seeds collected from fence-line margins were more germinable than B. rigidus from neighbouring cropped areas. Populations of B. rigidus also showed strong inhibition of seed germination when exposed to light. This inhibitory effect of light on seed germination was not seen in the B. diandrus collections. Two populations of B. rigidus from Yorke Peninsula showed little germination (<15% germination in complete darkness) until well after the start of the next growing season. These 2 populations did, however, show a large response to treatment with gibberellic acid (1 mm), indicating high seed viability but presence of deep dormancy. From a practical point of view, the germination behaviour (longer dormancy and light inhibition) exhibited by B. rigidus would allow this species to proliferate under conservation tillage systems such as no-till, where seeds only experience complete darkness after burial following the sowing operation. Germination behaviour of B. rigidus observed in this study is expected to contribute to greater seed carry-over from one season to the next, and favour its colonisation in crops, as seen in the current field survey.
A human cytomegalovirus antagonist of type I IFN-dependent signal transducer and activator of transcription signaling
Authors: Paulus Christina , Krauss Steffen , Nevels Michael
Published: February 2006

Type I IFNs are crucial components of the innate immune response to viral attack. They are rapidly synthesized and secreted after infection with human cytomegalovirus (CMV) and trigger a signal transduction pathway that involves successive activation and nuclear translocation of signal transducer and activator of transcription 1 (STAT1) and STAT2. The activated STATs, together with the IFN regulatory factor 9 protein, form a trimeric transcription complex (IFN-stimulated gene factor 3) that stimulates expression of numerous IFN-responsive genes, many of which exhibit antiviral activity. Here we demonstrate that the viral 72-kDa IE1 protein (IE1-72kDa) confers partial resistance to the antiviral activity of type I IFNs upon CMV. Accordingly, IFN-responsive transcripts accumulate to substantially increased levels after infection with an IE1-deficient mutant as compared with wild-type virus, and ectopic expression of the viral protein in stably transfected cells is sufficient to block their induction. We further show that IE1-72kDa forms a physical complex with STAT1 and STAT2 in nuclei of infected cells and
in vitro
and prevents association of STAT1, STAT2, and IFN regulatory factor 9 with promoters of IFN-responsive genes
in vivo
. Our results indicate that the viral protein blocks an intranuclear step after nuclear translocation and before DNA binding of IFN-stimulated gene factor 3, presumably by interfering with the integrity and/or correct subnuclear localization of the protein complex. This study identifies the CMV IE1-72kDa protein as a viral antagonist of the cellular innate immune response, inhibiting IFN-dependent STAT signaling by means of an unprecedented molecular mechanism.
Teaching of psychology in Brazil
Authors: Hutz Claudio S. , Gomes William , McCarthy Sherri
Published: February 2006

Psychology programs were first recognized in Brazilian universities during the mid‐20th century. Prior to that, psychology had been taught in conjunction with other programs such as medicine, law, and education. The growth of psychology programs has been rapid in the last 25 years. From the time the Brazilian government first established a 5‐year degree program in 1962, the number of psychology programs regulated by the Ministry of Education has increased to about 150. Graduate programs, established in 1965 and 1968, are also rapidly expanding. Psychology teaching draws on both European and US traditions in content and teaching methodology. A sociocultural psychological orientation is emphasized. Psychologists are prepared in 5‐year undergraduate programs including 2 years of internship and extensive coursework in all areas of the discipline, including neurophysiology, psychobiology, social psychology, clinical psychology, developmental psychology, health psychology, and organizational psychology. Programs must follow national curriculum guidelines. There is no consensus as to which textbooks to use in particular courses and these decisions are generally left to the discretion of the professors. The preference is for use of customized collections of readings rather than books. Textbooks are thought to provide one‐sided perspectives and to discourage library research. The increasing availability of on‐line journals and e‐books has revolutionized information access in Brazil, as in the rest of the world, and these are often used. The goals of undergraduate psychology programs are to prepare capable psychologists to work in a variety of capacities to benefit Brazilian society as a whole. The majority of psychologists practice in urban areas. Community organizations and social movements operating in rural areas may also have psychologists on staff. The optimism, respect for diversity, and dedication to democratic principles that are leading Brazil quickly into strong economic and social prominence in the 21st century are reflected in the teaching of psychology.
The education of psychologists in Greece
Authors: Georgas James
Published: February 2006

There are four departments of psychology in Greece: the University of Crete, the National and Capodistrian University of Athens, the Aristoteleian University of Thessalonike, and Panteios University. Entry to university is based on national examinations and marks in secondary schools. The number of undergraduate students accepted each year at the four Departments of Psychology is approximately 800, and total number of undergraduate students enrolled is approximately 3000. Three degrees are offered in psychology. The Ptychion (Bachelors) degree requires 4 years of study and the degree is generic in that there is no specialization. The Masters degree (Metaptychiako Diploma) is in areas of practice such as clinical psychology, school psychology, and organizational and work psychology, and requires 2 or 3 years of study in addition to internship at a mental health centre, school, or organization. These programmes also lead to the Doctor of Philosophy, but doctorates are also awarded in other areas of psychology through research. Licensing of psychology graduates with at least the Ptychion degree is granted by the Ministry of Welfare. In addition, the Masters level programmes of approved psychology programmes entitle the candidates to the European Diploma of Psychology, which is awarded by the European Federation of Psychologists Associations by national accreditation committees under the supervision of the EFPA accreditation committee.
Teaching psychology as a science in Italy
Authors: Prandini Carlo , McCarthy Sherri
Published: February 2006

Teaching of psychology as a science in Italy has developed steadily over the last few decades. University programs have experienced growth and psychology programs in some secondary schools and in teacher training programs may be better developed than those in other countries. Italian secondary school programs last for 5 years, and psychology is taught every year for both semesters. A postgraduate course, which includes training in psychology, is now mandatory for all public school teachers in Italy, as well. The first level of university education in psychology now corresponds to “Class 34”, Psychological Sciences and Techniques, and includes courses such as: Behaviour and Social Relation Sciences; Clinical and Community Sciences; and Techniques and Psychology of Educational Relations. Each course contains different aspects of a fixed national curriculum. All share a general scientific focus and teach practical abilities in specific areas of psychology. Two types of degrees are possible for undergraduates. A 3‐year degree qualifies students to practice as a “psychological assistant” in a restricted range of areas. A 3‐year degree followed by an additional 2 years of study allows the graduate to practise as a psychologist. Graduate programs then provide specific specialization focus. At present there are over 500 psychology faculty members in Italian universities. Goals of university psychology programs are to facilitate student mastery of the wealth of information in the discipline and to prepare competent psychologists. The lecture is a common teaching method. In the last decade, many teachers have also adopted more active learning methods. Discussions of assigned readings are used. In addition, students engage in guided practice activities, conduct library research, participate in empirical studies, and write in‐depth papers on various aspects of psychology. Course grades are generally determined by written tests that include both multiple‐choice and free‐response items. Field placement is typically evaluated through written reports and practical exercises.
Teaching undergraduate psychology in the Philippines: A summary of current programs, policies, and instruction
Authors: Gines Adelaida C.
Published: February 2006

Undergraduate psychology programs in the Philippines have grown from 44 institutions 20 years ago to 170 colleges and universities at present. It is not clear when psychology was first taught in the Philippines, however in 1926 psychology was offered as a course separate from philosophy. Then the department of psychology was established at the University of the Philippines, attached to the school of education. Other psychology departments were created during the early 1930s. The BS degree in Psychology was first offered in 1948 at the University of Santo Tomas. This university also offered the first Master's and Doctoral degrees in the discipline. After its separation from philosophy, psychology was closely identified with education until the 1960s. The teaching of the discipline emphasized education courses, specifically on guidance and counselling, which served as supporting courses in the psychology curriculum. Now, students are required to have a minimum of 63 units in general education, 45 units in major courses and 18 units in other courses to be determined by the institution, for a total of 126 units. These required courses are similar to many undergraduate psychology program courses in the USA. Philippine undergraduate psychology programs are of two general types, the AB and BS degrees. Both are 4‐year single major degree programs. Areas of emphasis commonly offered in AB or BS psychology in addition to general and educational emphasis include industrial psychology, clinical psychology, guidance and counselling, special education, and child development. Psychology programs anchor on the mission statement of the Psychological Association of the Philippines, “to be a world‐class community of psychologists committed to personal and professional growth, human service and social transformation.” Faculty members use a variety of modern teaching methods, including experiential learning, fieldwork, discussion, peer tutoring, and cooperative group work as well as lectures and reading material to help students reach this goal.
Undergraduate education in psychology: United States
Authors: Brewer Charles L.
Published: February 2006

Until the last quarter of the 19th century, many colleges and universities in the USA did not have separate departments of psychology. Now, psychology undergraduate degrees are among the most popular and frequently awarded in US higher education. Undergraduate psychology programs appeal to students for many reasons, including self‐understanding as well as their relatedness to other career paths of interest. Unlike undergraduate programs in most of the world, which are 5 years in length and designed to prepare professional psychologists, programs in the US are 4 years in length and do not prepare professional psychologists. Licensed psychologists in the US are generally required to hold doctoral degrees. Graduate programs to prepare psychologists are accredited by the American Psychological Association, but undergraduate programs vary widely and are evaluated by state and regional accrediting entities. Teaching methods, materials, and forms of student assessment also differ widely. Providing specific information about program and course requirements, because of this variation, is impossible. The majority of programs include a combination of general studies and psychology courses. Required psychology courses include general, developmental, social, history, learning, experimental, research, and statistics courses as well as seminars on other topics and require approximately 130 credit hours of total coursework. Lecture, discussion, peer‐tutoring, reading, written reports, and exams are common teaching methods. Most instructors require textbooks and supplemental readings as well. Since 1950, numerous groups have studied the undergraduate psychology curriculum. Recent efforts to clarify learning goals and outcomes for high school psychology courses and courses taught within the undergraduate psychology major have focused on establishing objectives, competencies, and content guidelines. Important work on assessing academic outcomes is ongoing, as are activities designed to internationalize the curriculum. Considering the dramatic achievements of the past decade, the future appears bright for the teaching of undergraduate psychology within US universities.
A Risk Index for Sternal Surgical Wound Infection After Cardiovascular Surgery
Authors: Kohli Michele , Yuan Lilian , Escobar Michael , David Tyrone , Gillis Grant , Garcia Marta , Conly John
Published: February 2006

Objectives:

To identify factors that increase the risk of sternal surgical wound infection after cardiovascular surgery and to develop a bedside clinical risk index using these factors.

Design:

A risk index was developed using clinical data collected from a cohort of 11,508 cardiac surgery patients and validated using three independent subsets of the data. With two of these subsets, we derived a logistic regression equation and then modified the scoring algorithm to simplify the calculation of patient risk scores by clinicians. The final subset was used to validate the index. The area under the receiver operating characteristic (aROC) curve was the primary measure of goodness of fit.

Setting:

Toronto General Hospital, a teaching hospital and the largest center for cardiac surgery in Ontario, Canada.

Patients:

Cardiac surgery patients receiving cardiopulmonary bypass between April 1, 1990, and December 31, 1995, who survived at least 6 days after surgery.

Results:

Variables that were used to construct the risk index included reoperation due to complication (odds ratio, 4.3; range, 1.9 to 8.5), diabetes (odds ratio, 2.4; range, 1.5 to 3.7), more than 3 days in the intensive care unit (odds ratio, 5.4; range, 3.2 to 8.7), and use of the internal mammary artery for revascularization (odds ratio, 3.2; range, 1.7 to 5.8). Validation showed that the index had an aROC curve of 0.64.

Conclusions:

The risk index described in this article allows clinicians to quickly stratify patients into four risk groups associated with an increasing risk of sternal surgical wound infection. It may be used perioperatively or as part of a wound infection surveillance system.
Risk Factors for Spinal Surgical-Site Infections in a Community Hospital: A Case–Control Study
Authors: Apisarnthanarak Anucha , Jones Marilyn , Waterman Brian M. , Carroll Cathy M. , Bernardi Robert , Fraser Victoria J.
Published: February 2006

Objective:

To characterize risk factors for surgical-site infection after spinal surgery.

Design:

A case–control study.

Setting:

A 113-bed community hospital.

Method:

From January 1998 through June 2000, the incidence of surgical-site infection in patients undergoing laminectomy, spinal fusion surgery, or both increased at community hospital. A We compared 13 patients who acquired surgical-site infections after laminectomy, spinal fusion surgery, or both with 47 patients who were operated on during the same time period but did not acquire a surgical-site infection. Information collected included demographics, risk factors, personnel involved in the operations, length of hospital stay, and hospital costs.

Results:

Of 13 case-patients, 9 (69%) were obese, 9 (69%) had spinal compression, 5 (38.5%) had a history of tobacco use, and 4 (31%) had diabetes. Oxacillin-sensitiveStaphylococcus aureus(6 of 13; 46%) was the most common organism isolated. Significant risk factors for postoperative spinal surgical-site infection were dural tear during the surgical procedure and the use of glue to cement the dural patch (3 of 13 [23%] vs 1 of 47 [2.1%] ;P= .02) and American Society of Anesthesiologists risk class of 3 or more (6 of 13 [46.2%] vs 7 of 47 [15%];P= .02). Case-patients were more likely to have prolonged length of stay (median, 16 vs 4 days;P< .001). The average excess length of stay was 11 days and the excess cost per case was $12,477.

Conclusion:

Dural tear and the use of glue should be evaluated as potential risk factors for spinal surgical-site infection. Systematic observation for potential lapses in sterile technique and surgical processes that may increase the risk of infection may help prevent spinal surgical-site infection.
Hemorrhage After Coronary Artery Bypass Graft Procedures
Authors: Herwaldt Loreen A , Swartzendruber Sheri K. , Zimmerman M. Bridget , Scholz David A. , Franklin Jo Ann , Caldarone Christopher A.
Published: February 2006

Objectives:

To identify risk factors for excessive bleeding after coronary artery bypass graft (CABG) procedures and to quantify the outcomes related to this complication.

Design:

We conducted a case–control study to identify risk factors for hemorrhage following CABG surgery and a historical cohort study to quantify outcomes of hemorrhage.

Setting:

The cardiothoracic surgery service of a university hospital.

Results:

Factors associated with excessive blood loss were recent catheterization (odds ratio [OR] = 0.44; 95% confidence interval [CI95], 0.21 to 0.91); age older than 65 years (OR = 1.94; CI95, 0.96 to 3.93); bypass time of 150 minutes or more (OR = 2.91; CI95, 1.09 to 7.81); and postoperative platelet count of 160,000/mm3 or less (OR = 2.36; CI95, 1.06 to 5.22). The attributable cost of a postoperative hemorrhage was $3,866 (P= .0002) overall, $9,912 (P= .0001) for patients who required reoperation, and $3,316 (P= .03) for those treated medically. The median attributable postoperative length of stay was 1 day longer for cases than for controls (P= .011). Postoperatively, patients who hemorrhaged received significantly larger volumes of packed red blood cells (P< .0001), fresh frozen plasma (P< .0001), platelets (P< .0001), plasminate (P= .007), protamine sulfate (P< .0001), desmopressin acetate (P< .0001), and epsilon-aminocaproic acid (P< .0001) than did controls.

Conclusions:

Age, duration of bypass, and postoperative platelet count were associated with excessive bleeding. Hemorrhage after CABG surgery significantly increased the length of stay and cost of care.
Resource Utilization Among Patients With Sepsis Syndrome
Authors: Bates David W. , Yu D. Tony , Black Edgar , Sands Kenneth E. , Schwartz J. Sanford , Hibberd Patricia L. , Graman Paul S. , Lanken Paul N. , Kahn Katherine L. , Snydman David R. , Parsonnet Jeffrey , Moore Richard , Platt Richard
Published: February 2006

Objective:

To assess the resource utilization associated with sepsis syndrome in academic medical centers.

Design:

Prospective cohort study.

Setting:

Eight academic, tertiary-care centers.

Patients:

Stratified random sample of 1,028 adult admissions with sepsis syndrome and all 248,761 other adult admissions between January 1993 and April 1994. The main outcome measures were length of stay (LOS) in total and after onset of sepsis syndrome (post-onset LOS) and total hospital charges.

Results:

The mean LOS for patients with sepsis was 27.7 ± 0.9 days (median, 20 days), with sepsis onset occurring after a mean of 8.1 ± 0.4 days (median, 3 days). For all patients without sepsis, the LOS was 7.2 ± 0.03 days (median, 4 days). In multiple linear regression models, the mean for patients with sepsis syndrome was 18.2 days, which was 11.0 days longer than the mean for all other patients (P< .0001), whereas the mean difference in total charges was $43,000 (bothP< .0001). These differences were greater for patients with nosocomial as compared with community-acquired sepsis, although the groups were similar after adjusting for pre-onset LOS. Eight independent correlates of increased post-onset LOS and 12 correlates of total charges were identified.

Conclusions:

These data quantify the resource utilization associated with sepsis syndrome, and demonstrate that resource utilization is high in this group. Additional investigation is required to determine how much of the excess post-onset LOS and charges are attributable to sepsis syndrome rather than the underlying medical conditions.
Modelling the glacial isostatic adjustment of the UK region
Authors: Milne G.A , Shennan I , Youngs B.A.R , Waugh A.I , Teferle F.N , Bingley R.M , Bassett S.E , Cuthbert-Brown C , Bradley S.L
Published: February 2006

The glacial isostatic adjustment of the UK region has been considered in a number of recent studies. We have revisited this problem in order to: (i) highlight some key issues with regard to limitations in the ice modelling approach adopted in these studies and (ii) consider the constraints provided from observations of crustal motion available via continuous global positioning system monitoring. With regard to the first aim, we have found that: (i) previous studies have significantly overestimated ice thicknesses in regions where trim line field constraints were adopted and (ii) the duration of the glaciation phase of the UK ice sheet is a critical aspect of the model and that discrepancies in this model component have led to inconsistent inferences of Earth model parameters. With regard to the second aim, we have found that predictions of horizontal velocities (relative to a chosen site) based on a UK ice model calibrated to fit the regional sea-level database capture the geometry of the signal well but only account for 10% of the magnitude (for a range of Earth models).
Impacts and responses to sea-level rise: a global analysis of the SRES scenarios over the twenty-first century
Authors: Nicholls Robert J , Tol Richard S.J
Published: February 2006

Taking the Special Report on Emission Scenarios (SRES) climate and socio-economic scenarios (A1FI, A2, B1 and B2 ‘future worlds’), the potential impacts of sea-level rise through the twenty-first century are explored using complementary impact and economic analysis methods at the global scale. These methods have never been explored together previously. In all scenarios, the exposure and hence the impact potential due to increased flooding by sea-level rise increases significantly compared to the base year (1990). While mitigation reduces impacts, due to the lagged response of sea-level rise to atmospheric temperature rise, impacts cannot be avoided during the twenty-first century by this response alone. Cost–benefit analyses suggest that widespread protection will be an economically rational response to land loss due to sea-level rise in the four SRES futures that are considered. The most vulnerable future worlds to sea-level rise appear to be the A2 and B2 scenarios, which primarily reflects differences in the socio-economic situation (coastal population, Gross Domestic Product (GDP) and GDP/capita), rather than the magnitude of sea-level rise. Small islands and deltaic settings stand out as being more vulnerable as shown in many earlier analyses. Collectively, these results suggest that human societies will have more choice in how they respond to sea-level rise than is often assumed. However, this conclusion needs to be tempered by recognition that we still do not understand these choices and significant impacts remain possible. Future worlds which experience larger rises in sea-level than considered here (above 35 cm), more extreme events, a reactive rather than proactive approach to adaptation, and where GDP growth is slower or more unequal than in the SRES futures remain a concern. There is considerable scope for further research to better understand these diverse issues.
Autoimmune lymphoproliferative syndrome: molecular basis of disease and clinical phenotype
Authors: Worth Austen , Thrasher Adrian J. , Bobby Gaspar H.
Published: February 2006

Autoimmune lymphoproliferative syndrome (ALPS) is a variable clinical condition manifest by lymphoproliferative disease, autoimmune cytopenias and susceptibility to malignancy. Central to the cellular pathogenesis is defective FAS‐induced apoptosis, which in turn leads to dysregulation of lymphocyte homeostasis. The majority of patients have heterozygous mutations in the FAS (TNFRSF6) gene, but the condition is genetically heterogeneous and mutations in FAS ligand and caspase‐8 and caspase‐10, all of which are involved in Fas mediated signalling, have also been identified. This review provides a detailed insight into the pathophysiology of lymphocyte apoptosis and how this relates to the variable and complex clinical manifestations of ALPS.
Effect of glucocorticoids on stem cell factor expression in human asthmatic bronchi
Authors: Da Silva C. A. , de Blay F. , Israel‐Biet D. , Laval A.‐M. , Glasser N. , Pauli G. , Frossard N.
Published: February 2006

Background
Stem cell factor (SCF) is a major mast cell growth factor promoting differentiation, chemotaxis as well as inhibition of apoptosis of mast cells. Regulation of SCF expression by glucocorticoids has not yet been reported in human asthmatic bronchi.

Objective
To evaluate SCF mRNA and protein expression in biopsy specimen and bronchoalveolar lavage fluid, respectively, and to determine the mast cell numbers in biopsy sections from control and asthmatic subjects treated or not with glucocorticoids.

Methods
Volunteers were recruited out of pollen season. Asthmatic patients were allergic to common allergen extracts including grass and tree pollen, cat, dog or mite; three volunteers had non‐allergic asthma. Mast cell numbers were counted after anti‐human tryptase immunolabelling. SCF mRNA was quantified by real‐time fluorescent PCR (LightCycler™) after reverse transcription, and SCF protein was measured by ELISA.

Results
Asthmatic patients not treated with glucocorticoids showed a 5.8‐, 1.8‐ and 3.1‐fold significant increase in SCF mRNA, protein levels and mast cell numbers, respectively, compared with healthy volunteers of the control group (7.8 and 1.3 pg/μg SCF mRNA/GAPDH; 99.8±11.5 and 56.0±11.0 pg/mL SCF protein; 103±21 and 33±8 mast cells/mm2, respectively; P<0.05). In asthmatic patients treated with glucocorticoids, a significant decrease of SCF mRNA, protein levels and mast cell numbers was observed as compared with untreated asthmatic patients (1.1 pg/μg mRNA; 62.0±10.3 pg/mL SCF protein and 39±13 mast cells/mm2; P<0.05), reaching levels comparable to those of the control group.

Conclusion
Our study shows that SCF is expressed in the bronchus in humans in vivo. This expression is increased in asthma, and is parallel to the increased mast cell numbers in the airways. Both increases were normalized in glucocorticoid‐treated patients, strongly suggesting an involvement of SCF in the mast cell‐associated asthmatic disease.