bluuebunny/crossref_metadata_2025 huggingface dataset:
On the outage behaviour of large DS‐CDMA systems with LMMSE detection
Authors: Prätor Oliver , Fettweis Gerhard P.
Published: March 2006

The outage behaviour of the single cell DS‐CDMA uplink is investigated for flat Rayleigh fading channels. Goal of the work is to find an analytical way for the optimisation of the system spectral efficiency under some outage probability constraint by adjusting parameters such as modulation, spreading factor, code rate and number of codes per user. Therefore, the results of the asymptotic analysis for large CDMA systems with random spreading codes are used to obtain the signal‐to‐interference‐and‐noise ratio after the linear minimum mean‐squared‐error detector. This information is then deployed to characterise the system performance using bounds of the information theory. First, the ergodic behaviour is investigated with respect to the spectral efficiency for both coding at capacity and discrete modulation and coding at cut‐off rate. Then, the outage probability is defined and studied for coding at capacity. The influence of the system load on the outage is determined analytically and compared to simulation results. Afterwards, the impact of modulation and coding at cut‐off rate on the outage behaviour is considered. An expression is presented that allows to easily determine the additional required signal‐to‐noise ratio for modulation and coding at cut‐off rate from the capacity results. Finally, the investigations are extended to determine the maximum system spectral efficiency under given outage constraints. The optimum system loads corresponding to the maximum efficiencies are presented and shown to vary for the different modulation schemes. Copyright © 2006 AEIT.
Orthogonal transmit beamforming scheme based on semidefinite optimisation
Authors: Xu Hongji , Liu Ju , Rubio Francisco , Perez‐Neira Ana I.
Published: March 2006

The multiple‐access interference (MAI) is one of the major factors threatening the performance of multi‐user systems. Transmit beamforming is a powerful strategy to increase the system capacity and mitigate interference. Traditional zero‐forcing transmit beamforming (ZFTBF) is an effective means to remarkably suppress MAI if the downlink channel is precisely known. However, it is very difficult to get exact information on the actual channel in realistic scenarios. In this paper, we present an approach to achieve orthogonal transmit beamforming (OTBF), only in virtue of statistical information of the downlink channel by using semidefinite optimisation tools. Different criteria are considered to solve the same problem by satisfying specific constraints between the total transmission power and the quality of service (QoS) requirements of individual users. Furthermore, robust designs for the presented strategies are also analysed. Simulation results show the effectiveness and the robustness of these strategies. Copyright © 2006 AEIT.
Bit‐interleaved coded irregular modulation
Authors: Schreckenbach F. , Bauch G.
Published: March 2006

We consider a simple method to improve the adaptiveness and flexibility of bit‐interleaved coded modulation (BICM) with different iterative decoding schemes for bandwidth efficient transmission. The basic idea is to apply different signal constellations and mappings within one code word. The combination of different signal constellations allows a fine adaptation of the data rate to the channel characteristics with the modulation, even if only the average channel state is known at the transmitter. For a receiver performing iterative demapping and decoding (so called BICM‐ID system), the mixture of different mappings enables an optimisation of the iterative decoding process according to the system requirements. We call this approach bit‐interleaved codedirregularmodulation (BICIM) and analyse it using EXIT charts, capacity, error bounds and error rate simulations. Copyright © 2006 AEIT.
A 900 MHz CMOS RF transceiver including digital baseband and hardware‐MAC for IEEE 802.15.4/ZigBeeTM applications
Authors: Göpfert Lars , Hofmann Falk , Jacobasch Guido
Published: March 2006

This paper presents a fully‐integrated RF transceiver operating from 860 to 930 MHz. The device parameters are compliant to the IEEE 802.15.4 standard. The analogue portion of the chip contains a direct‐conversion receiver, a fractional‐N PLL, a direct‐conversion transmitter and a TR‐switch. Digital baseband signal processing as well as MAC support are also implemented on the same chip. Only minimal external components are needed to form a complete wireless network application two low‐cost crystals, the PLL loop filter, an antenna and a low‐cost 8 bit microcontroller. Therefore, this chip is one of the most integrated 802.15.4 transceiver ICs presented to date. The receiver input sensitivity is −98 dBm. The chip is fabricated in a 0.25 μm CMOS technology with MIM‐capacitors, deep n‐well and a thick top metal layer. Copyright © 2005 AEIT.
Synthesis and Characterization of Pt/C Nanocatalysts Using Room Temperature Ionic Liquids for Fuel Cell Applications
Authors: Xue X. , Liu C. , Lu T. , Xing W.
Published: March 2006

Carbon supported Pt nanocatalysts are prepared using different room temperature ionic liquids (RTILs) as the solvent and conventional preparation techniques, based on wet impregnation methods. The Pt/C nanocatalysts are characterized by XRD, TEM, EDX, and XPS. The results of the analyses show that the Pt/C catalysts, using different RTILs as solvents, are homogeneously dispersed with a narrow size distribution. The electro‐oxidation of liquid methanol on these catalysts is investigated at room temperature by cyclic voltammetry and chronoamperometry. The results have shown that the Pt/C catalysts prepared using RTILs are more active than the other Pt/C catalysts prepared by the authors. Surface area measurements of the Pt metal, conducted by electro‐oxidation of preadsorbed CO, indicate that catalysts prepared using RTILs as the solvents have higher surface area. The Pt/C nanocatalysts, prepared using RTILs, exhibit enhanced activity for the methanol oxidation reaction, compared with the Pt/C catalysts prepared by the impregnation method and commercial Pt/C catalysts.
BH3‐only proteins: Integrated control point of apoptosis
Authors: Shibue Tsukasa , Taniguchi Tadatsugu
Published: March 2006

Bcl‐2 family proteins play central roles in the regulation of most, if not all, apoptotic pathways, and hence this family plays a critical role in oncogenesis. The Bcl‐2 homology 3 (BH3)‐only members of this family are “proapoptotic,” promoting apoptosis by sensing cellular stresses: that is, they are activated or induced in response to stress stimuli. These BH3‐only proteins then interfere with the function of “prosurvival” Bcl‐2 family members, thereby promoting the progression of apoptosis. It has long been recognized that the induction and activation of each of the BH3‐only proteins are subject to the type of stress stimulus. Although it was originally assumed that all the BH3‐only proteins exert similar effects on the downstream apoptotic machinery, recent studies have uncovered their distinct functional properties, indicating the operation of more intricate, versatile control mechanisms of apoptosis. In this review, we will summarize recent findings on the diversity in the activation and function of BH3‐only proteins. In particular, we focus on the overlapping and individual roles of 2 BH3‐only proteins, Puma and Noxa, in the context of the apoptotic response induced by the tumor suppressor p53. © 2006 Wiley‐Liss, Inc.
IRS‐1–Rad51 nuclear interaction sensitizes JCV T‐antigen positive medulloblastoma cells to genotoxic treatment
Authors: Trojanek Joanna , Ho Thu , Croul Sidney , Wang Jin Ying , Chintapalli Janaki , Koptyra Mateusz , Giordano Antonio , Khalili Kamel , Reiss Krzysztof
Published: March 2006

The large T‐antigen from human polyomavirus JC (JCV T‐antigen) is suspected to play a role in malignant transformation. Previously, we reported that JCV T‐antigen requires the presence of a functional insulin‐like growth factor I receptor (IGF‐IR) for transformation of fibroblasts and for survival of medulloblastoma cell lines; that IGF‐IR is phosphorylated in medulloblastoma biopsies and that JCV T‐antigen inhibits homologous recombination‐directed DNA repair, causing accumulation of mutations. Here we are evaluating whether JCV T‐antigen positive and negative mouse medulloblastoma cell lines, which significantly differ in their tumorigenic properties, are also different in their abilities to repair double strand breaks of DNA (DSBs). Our results show that despite much stronger tumorigenic potential, JCV T‐antigen positive medulloblastoma cells are more sensitive to genotoxic agents (cisplatin and γ‐irradiation). Subsequent analysis of DNA repair of DSBs indicated that homologous recombination‐directed DNA repair (HRR) was selectively attenuated in JCV T‐antigen positive medulloblastoma cells. JCV T‐antigen did not affect HRR directly. In the presence of JCV T‐antigen, insulin receptor substrate 1 (IRS‐1) translocated to the nucleus where it co‐localized with Rad51, possibly attenuating HRR. © 2006 Wiley‐Liss, Inc.
Serum C‐peptide levels and breast cancer risk: Results from the European prospective investigation into cancer and nutrition (EPIC)
Authors: Verheus Martijn , Peeters Petra H.M. , Rinaldi Sabina , Dossus Laure , Biessy Carine , Olsen Anja , Tjønneland Anne , Overvad Kim , Jeppesen Majbritt , Clavel‐Chapelon Françoise , Téhard Bertrand , Nagel Gabriele , Linseisen Jakob , Boeing Heiner , Lahmann Petra H. , Arvaniti Athina , Psaltopoulou Theodora , Trichopoulou Antonia , Palli Domenico , Tumino Rosario , Panico Salvatore , Sacerdote Carlotta , Sieri Sabina , van Gils Carla H. , Bueno‐de‐Mesquita Bas H. , González Carlos A. , Ardanaz Eva , Larranaga Nera , Garcia Carmen Martinez , Navarro Carmen , Quirós J. Ramón , Key Tim , Allen Naomi , Bingham Sheila , Khaw Kay‐Tee , Slimani Nadia , Riboli Elio , Kaaks Rudolf
Published: March 2006

It has been hypothesized that chronic hyperinsulinemia, a major metabolic consequence of physical inactivity and excess weight, might increase breast cancer risk by direct effects on breast tissue or indirectly by increasing bioavailable levels of testosterone and estradiol. Within the European Prospective Investigation into Cancer and Nutrition (EPIC), we measured serum levels of C‐peptide—a marker for pancreatic insulin secretion—in a total of 1,141 incident cases of breast cancer and 2,204 matched control subjects. Additional measurements were made of serum sex hormone binding globulin (SHBG) and sex steroids. Conditional logistic regression models were used to estimate breast cancer risk for different levels of C‐peptide. C‐peptide was inversely correlated with SHBG and hence directly correlated with free testosterone among both pre and postmenopausal women. C‐peptide and free estradiol also correlated positively, but only among postmenopausal women. Elevated serum C‐peptide levels were associated with a nonsignificant reduced risk of breast cancer diagnosed up to the age of 50 years [odds ratio (OR) = 0.70, (95% confidence interval (CI), 0.39–1.24); ptrend = 0.05]. By contrast, higher levels of C‐peptide were associated with an increase of breast cancer risk among women above 60 years of age, however only among those women who had provided a blood sample under nonfasting conditions [OR = 2.03, (95% CI, 1.20–3.43); ptrend = 0.01]. Our results do not support the hypothesis that chronic hyperinsulinemia generally increases breast cancer risk, independently of age. Nevertheless, among older, postmenopausal women, hyperinsulinemia might contribute to increasing breast cancer risk. © 2006 Wiley‐Liss, Inc.
The antimicrobial peptide, lactoferricin B, is cytotoxic to neuroblastoma cells in vitro and inhibits xenograft growth in vivo
Authors: Eliassen Liv Tone , Berge Gerd , Leknessund Arild , Wikman Mari , Lindin Inger , Løkke Cecilie , Ponthan Frida , Johnsen John Inge , Sveinbjørnsson Baldur , Kogner Per , Flægstad Trond , Rekdal Øystein
Published: March 2006

Antimicrobial peptides have been shown to exert cytotoxic activity towards cancer cells through their ability to interact with negatively charged cell membranes. In this study the cytotoxic effect of the antimicrobial peptide, LfcinB was tested in a panel of human neuroblastoma cell lines. LfcinB displayed a selective cytotoxic activity against both MYCN‐amplified and non‐MYCN‐amplified cell lines. Non‐transformed fibroblasts were not substantially affected by LfcinB. Treatment of neuroblastoma cells with LfcinB induced rapid destabilization of the cytoplasmic membrane and formation of membrane blebs. Depolarization of the mitochondria membranes and irreversible changes in the mitochondria morphology was also evident. Immuno‐ and fluorescence‐labeled LfcinB revealed that the peptide co‐localized with mitochondria. Furthermore, treatment of neuroblastoma cells with LfcinB induced cleavage of caspase‐6, ‐7 and ‐9 followed by cell death. However, neither addition of the pan‐caspase inhibitor, zVAD‐fmk, or specific caspase inhibitors could reverse the cytotoxic effect induced by LfcinB. Treatment of established SH‐SY‐5Y neuroblastoma xenografts with repeated injections of LfcinB resulted in significant tumor growth inhibition. These results revealed a selective destabilizing effect of LfcinB on two important targets in the neuroblastoma cells, the cytoplasmic‐ and the mitochondria membrane. © 2006 Wiley‐Liss, Inc.
Randomized controlled trial of human papillomavirus testing versus Pap cytology in the primary screening for cervical cancer precursors: Design, methods and preliminary accrual results of the Canadian cervical cancer screening trial (CCCaST)
Authors: Mayrand Marie‐Hélène , Duarte‐Franco Eliane , Coutlée François , Rodrigues Isabel , Walter Stephen D. , Ratnam Sam , Franco Eduardo L. ,   for the CCCaST Study Group
Published: March 2006

Since infection with oncogenic human papillomavirus (HPV) has been considered a necessary cause of cervical cancer, tests for oncogenic HPV types have been proposed as adjuncts or replacements to Pap cytology. We designed the Canadian Cervical Cancer Screening Trial (CCCaST) to compare the relative efficacy of HPV DNA testing and Pap cytology in primary screening for cervical cancer and its high‐grade precursors. CCCaST randomized women aged 30–69 years in Montreal (Quebec) and in St. John's (Newfoundland) to 1 of 2 screening groups: focus on Pap (conventional) or focus on HPV testing (Hybrid Capture 2). Women in both arms received both tests, but were randomized as to their order, the first test being the index test. Women with an abnormal Pap test or a positive HPV test underwent colposcopy and biopsy, as did a random sample of women with a negative index test. CCCaST enrolled 9,667 women between October 2002 and October 2004. At enrolment, 2.8% had an abnormal Pap test, 6.1% had a positive HPV test and 1.1% were abnormal in both tests. ASC‐US was the most frequent cytological abnormality, representing 64% of abnormal Pap results. The frequency of abnormal Pap and HPV results decreased with increasing age and the proportion of HPV‐positive results increased with the severity of Pap abnormality. Efficacy analysis will determine if the extra referrals with HPV DNA testing will translate into a relevant increase in high‐grade cervical cancer precursor detection. Because of its design, CCCaST will provide sound evidence for formulating cervical cancer screening strategies. © 2006 Wiley‐Liss, Inc.
Tissue array analysis of expression microarray candidates identifies markers associated with tumor grade and outcome in serous epithelial ovarian cancer
Authors: Ouellet Véronique , Guyot Marie‐Claude , Le Page Cécile , Filali‐Mouhim Abdelali , Lussier Christian , Tonin Patricia N. , Provencher Diane M. , Mes‐Masson Anne‐Marie
Published: March 2006

Molecular profiling is a powerful approach to identify potential clinical markers for diagnosis and prognosis as well as providing a better understanding of the biology of epithelial ovarian cancer. On the basis of the analysis of HuFL expression data, we have previously identified genes that distinguish low malignant potential and invasive serous epithelial ovarian tumors. In this study, we used immunohistochemistry to monitor a subset of differently expressed candidates (Ahr, Paep, Madh3, Ran, Met, Mek1, Ccne1, Ccd20, Cks1 and Cas). A tissue array composed of 244 serous tumors of different grades (0–3) and stages (I–IV) was used in this analysis. All markers assayed presented differential protein expression between serous tumors of low and high grade. Significant differences in Ccne1 and Ran expression were observed in a comparison of low malignant potential and grade 1 tumor samples (p < 0.01). In addition, irrespective of the grade, Ccne1, Ran, Cdc20 and Cks1 showed significant differences of expression in association with the clinical stage of disease. While high level of Ccne1 have previously been associated with poor outcomes, here we found that high level of either Ran or Cdc20 appear to be more tightly associated with a poor prognosis (p < 0.001, 0.03, respectively). The application of these biomarkers in both the initial diagnosis and prognostic attributes of patients with epithelial ovarian tumors should prove to be useful in patient management. © 2006 Wiley‐Liss, Inc.
Sun exposure and host phenotype as predictors of cutaneous melanoma associated with neval remnants or dermal elastosis
Authors: Lee Eva Y. , Williamson Richard , Watt Peter , Hughes Maria Celia , Green Adèle C. , Whiteman David C.
Published: March 2006

Recent research suggests that cutaneous melanomas may arise through 2 distinct pathways, characterized by chronic sun exposure on one hand and nevus‐prone phenotype of the host on the other. Two histological characteristics of melanoma consistent with these divergent origins are dermal elastosis in adjacent skin and neval remnants contiguous with the tumor, respectively. To further explore causal heterogeneity in melanoma, we compared sun exposure histories and phenotypic characteristics among a population‐based sample of patients newly diagnosed with cutaneous melanoma with and without contiguous neval remnants or dermal elastosis. Tissue blocks were obtained for 141 patients: 53 with superficial spreading melanoma (SSM) of the back, 42 with SSM of head and neck (H & N), and 39 and 7 with lentigo maligna/lentigo maligna melanoma (LM/LMM) of the H & N and back, respectively. Melanomas of the H & N were less likely than those on back to have neval remnants (adjusted OR 0.6, 95% CI 0.3–1.4), but were significantly more likely to have dermal elastosis (adjusted OR 9.3, 95% CI 3.5–25). In site‐specific analyses, we found that H & N melanomas with neval remnants were more likely than those without neval remnants to arise in people with more than 60 nevi (adjusted OR 2.1, 95% CI 0.3–14.3), but were less likely to arise in those with more than 20 actinic keratoses. Less marked associations were observed for melanomas of the back. High levels of sun exposure strongly predicted dermal elastosis for H & N melanomas (OR 22.5, 95% CI 2.1–245), but not for melanomas of the back (OR 2.1, 95% CI 0.4–11). We conclude that melanomas with different histologic characteristics have different risk factor profiles, particularly on the head and neck. These data accord with the hypothesis that melanomas arise through different causal pathways. © 2006 Wiley‐Liss, Inc.
Noninvasive diagnosis of nasopharyngeal carcinoma: Nasopharyngeal brushings reveal high Epstein‐Barr virus DNA load and carcinoma‐specific viral BARF1 mRNA
Authors: Stevens Servi J.C. , Verkuijlen Sandra A.W.M. , Hariwiyanto Bambang , Harijadi  , Paramita Dewi K. , Fachiroh Jajah , Adham Marlinda , Tan I. Bing , Haryana Sophia M. , Middeldorp Jaap M.
Published: March 2006

Nasopharyngeal carcinoma (NPC) is the most prevalent ENT‐tumour in Indonesia. We investigated the primary diagnostic value of Epstein‐Barr virus (EBV) DNA load and mRNA detection in noninvasive nasopharyngeal (NP) brushings, obtained prospectively from consecutive Indonesian ENT‐patients with suspected NPC (N = 106) and controls. A subsequent routine NP biopsy was taken for pathological examination and EBER‐RISH, yielding 85 confirmed NPC and 21 non‐NPC tumour patients. EBV DNA and human DNA load were quantified by real‐time PCR. NP brushings from NPC patients contained extremely high EBV DNA loads compared to the 88 non‐NPC controls (p < 0.0001). Using mean EBV DNA load in controls plus 3 SD as cut‐off value, specificity, sensitivity, positive and negative predictive values were 98, 90, 97 and 91%, respectively. Epstein‐Barr nuclear antigen 1 (EBNA1) and the carcinoma‐specific BARF1 mRNA were detected by nucleic acid sequence based amplification and found in 86 and 74% of NP brushings, confirming NPC tumour cell presence. EBV RNA positivity was even higher in fresh samples stored at −80°C until RNA expression analyses (88% for both EBNA1 and BARF1). EBV RNA‐negative NP brushings from proven NPC cases had the lowest EBV DNA loads, indicating erroneous sampling. No EBV mRNA was detected in NP brushings from healthy donors and non‐NPC patients. In conclusion, EBV DNA load measurement combined with detection of BARF1 mRNA in simple NP brushings allows noninvasive NPC diagnosis. It reflects carcinoma‐specific EBV involvement at the anatomical site of tumour development and reduces the need for invasive biopsies. This procedure may be useful for confirmatory diagnosis in large serological NPC screening programs and has potential as prognostic tool. © 2006 Wiley‐Liss, Inc.
c‐Myc‐dependent etoposide‐induced apoptosis involves activation of Bax and caspases, and PKCdelta signaling
Authors: Albihn Ami , Lovén Jakob , Ohlsson Johan , Osorio Lyda M. , Henriksson Marie
Published: March 2006

The c‐Myc transcription factor is a key regulator of cell proliferation, differentiation, and apoptosis. While deregulation of myc induces programmed cell death, defects in the apoptotic program facilitate Myc‐driven tumor development. We have treated c‐Myc inducible mouse cells and rat fibroblasts with different c‐myc status with cytotoxic drugs to explore the effect of c‐Myc on drug‐induced apoptosis. We found that c‐Myc overexpression potentiated etoposide‐, doxorubicin‐, and cisplatin‐induced cell death in mouse fibroblasts. In addition, these drugs provoked a strong apoptotic response in c‐Myc‐expressing cells, but a weak apoptosis in c‐myc null Rat1 cells. In contrast, staurosporine‐induced apoptosis was c‐Myc‐independent, confirming a functional apoptotic pathway in c‐myc null cells. Apoptosis was paralleled by c‐Myc‐dependent Bax‐activation after etoposide and doxorubicin treatment, but not after cisplatin administration. All three drugs induced higher caspase activation in c‐Myc expressing cells than in c‐myc null cells. Furthermore, etoposide treatment of c‐Myc expressing cells resulted in PKCδ cleavage, while inhibition of PKCδ reduced etoposide‐induced apoptosis and prevented Bax activation. Taken together, these findings suggest that Bax and caspase activation, together with PKCδ signaling are involved in c‐Myc‐dependent etoposide‐induced apoptosis. © 2006 Wiley‐Liss, Inc.
An intercomparison study of two land surface models using a 1‐D model and fife measurements
Authors: Alapaty Kiran , Mihailovic Dragutin T.
Published: March 2006

Two land‐surface parameterization schemes (ISBA (Interactions Soil‐Biosphere‐Atmosphere) and LAPS (Land‐Air‐Parameterization‐Scheme)) of differing complexity were implemented into a 1‐D atmospheric boundary layer model and evaluated utilizing the special observational data collected during the summer of 1987 from the FIFE measurements. Results from two case studies were analyzed during which boundary layer processes dominated the lower atmospheric processes. In the first case study (6 June 1987), we found that differences in the estimation of stomatal resistance in the two land‐surface models (LSMs) triggered many of the differences in results obtained using the two LSMs. In the second case study (11 July 1987), only minor differences existed between respective net radiation and stomatal resistance estimations, leading to similar boundary layer structures. Diagnostic results indicate that in both case studies growth rates of and depths of atmospheric boundary layers and vertical profiles of virtual potential temperatures, water vapor mixing ratio, and horizontal winds are very similar in LAPS and ISBA. Our future studies are directed at evaluating these two schemes using a regional climate version of the WRF model. Copyright © 2006 Royal Meteorological Society.
Variability of summer temperature over Egypt
Authors: Hasanean H. M. , Basset H. Abdel
Published: March 2006

Variations of summer temperature over Egypt have been studied using the data of 19 stations. The analysis of these data shows that the surface temperature is a stable climate element where its coefficient of variation (COV) is found to be low during summer. The time sequence of cumulative seasonal mean (CSM) is shown to exhibit bounded, oscillatory, nonperiodic behavior. The boundedness of the oscillation supports the notion of climate compensation; i.e. that spells of cold must eventually follow spells of warm. The trend analysis of the time series of our stations shows striking positive trend values during the last 20 years; this could be attributed not only to human activities but also to atmospheric circulation changes. Spectral analyses of the monthly values of the 19 stations were made. It was found that the first harmonic plays a dominant role in the regional climatological variations in Egypt; it explains more than 38% of the amplitude variations and may be related to the sunspot cycle, which affects summer temperature over Egypt. Other harmonics may be related to El Nino southern oscillation (ENSO) cycle, quasi‐biennial oscillation (QBO) cycle, and solar inertial motion cycle. Each of them contribute approximately 9% to summer temperature in Egypt and so their influence on summer temperatures in the area is not so much. Copyright © 2006 Royal Meteorological Society.
East Asian dust storm and weather disturbance: possible links to the Arctic Oscillation
Authors: Gong Dao‐Yi , Mao Rui , Fan Yi‐Da
Published: March 2006

In this work, the authors investigated the spring dust storm frequency variations in northern China and its relationship with weather disturbances, cold high, eddy kinetic energy (EKE), as well as the impact of the Arctic Oscillation (AO) on the dust storm frequency variations. It is found that there is a significantly decreasing trend of −26%/10 years in the dust storm frequency variations. In addition, the year‐to‐year variations are also remarkable, which account for 58.3% of the total variance of the dust storm frequency variations. The synoptic variance of 850 hPa height, EKE, and near‐surface cold highs are highly correlated with the dust storm frequency variations. During the last 40 years or so, there have been significant trends in synoptic variance, cold‐high frequency, and kinetic energy over northern China and Mongolia, which are −3.2, −4.0, and −5.0%/10 years, respectively. The trends are fairly consistent with long‐term variations of dust storm frequency. The AO shows good correlation with the interannual variations of the dust storm frequency. This out‐of‐phase relation is supported by the significantly negative correlations between AO index and eddy growth rate between 850/700 hPa in midlatitude East Asia, implying that AO can modulate weather disturbances and dust storm activities through influencing the atmospheric instability. It is found, however, that the spring AO index shows no evident long‐term trend. Land cover changes, global warming, and other climate teleconnections may, at least partly, be responsible for the secular decreasing of dust storm frequency over northern China. Copyright © 2006 Royal Meteorological Society.
Diversity and food quality properties of farmers' varieties of sorghum from Bénin
Authors: Kayodé AP Polycarpe , Linnemann Anita R , Nout MJ Rob , Hounhouigan Joseph D , Stomph Tjeerd Jan , Smulders Marinus JM
Published: March 2006

Farmers' varieties of sorghum from three communities in different regions of northern Bénin were analysed for their food quality and agro‐morphological properties, and also for their genetic diversity using amplified fragment length polymorphism (AFLP). Farmers' varieties of sorghum differed greatly with respect to their morphology and agronomic and food traits. Most of the varieties had long (>200 cm) stems (87%), loose panicles (79%) and a red or pink colour (52%). Most were susceptible to drought (54%) and to attacks by striga (79%), insects (99%) and birds (77%). Farmers evaluated the quality of the seeds for preparing porridges as being high for 60% of the varieties and 26% of the varieties were regarded as suitable for making beverages. Late‐maturing, large‐seeded, red or pink varieties are preferred by farmers for porridges and beverages. Gene diversity among varieties within regions, as measured by neutral markers, was similar for the three regions (0.211–0.240). However, across regions the short (<150 cm) stem varieties showed relatively high genetic diversity compared with long or medium stem varieties (0.378 vs 0.184–0.216 for long–medium stem varieties). Genetic differentiation (Fst) among regions and among stem lengths of varieties was significant and ranged between 0.086 and 0.135. Grain colour, stem length and panicle shape varied significantly with the region/stem length and correlated with the genetic differentiation of regions. No relationship could be detected between the genetic differentiation of the varieties and their food quality as expressed by the farmers. Implications of the findings for crop conservation and breeding are discussed. Copyright © 2006 Society of Chemical Industry
Single breath‐hold T1 measurement using low flip angle TrueFISP
Authors: Bokacheva L. , Huang A.J. , Chen Q. , Oesingmann N. , Storey P. , Rusinek H. , Lee V.S.
Published: March 2006

A method for estimating T1 using a single breath‐hold, segmented, inversion recovery prepared, true fast imaging with steady‐state precession (sIR‐TrueFISP) acquisition at low flip angle (FA) was implemented in this study. T1 values measured by sIR‐TrueFISP technique in a Gd‐DTPA‐doped water phantom and the human brain and abdomen of healthy volunteers were compared with the results of the standard IR fast spin echo (FSE) technique. A good correlation between the two methods was observed (R2 = 0.999 in the phantom, and R2 = 0.943 in the brain and abdominal tissues). The T1 values of the tissues agreed well with published results. sIR‐TrueFISP enables fast measurements of T1 to be obtained within a single breath‐hold with good accuracy, which is particularly important for chest and abdominal imaging. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Education not training: the challenge of developing professional autonomy
Authors: Esdaile Susan A. , Roth Linda M.
Published: March 2006

The aims of this paper are first, to differentiate between education and training, emphasizing the importance of the former in the professional education of occupational therapists; and second, to outline some of the possible threats to professional autonomy. A focus on training may result in a level of education that cannot sustain professional autonomy. However, the establishment of proscribed and detailed, nationally controlled educational standards may also limit a profession. The latter may occur when cost‐containment is a major societal concern, focusing educational standards on training and measurable outcomes of professional practice. Copyright © 2000 Whurr Publishers Ltd.
Being that bit older: mature students' experience of university and healthcare education
Authors: Shanahan Margaret
Published: March 2006

This study used a phenomenological approach to gain insight into the lives of a small number of mature female students on healthcare programmes at university. The qualitative methods used sought to reveal aspects of that lived experience that would explain why mature students lack confidence in their academic abilities. Data were collected from participants using an in‐depth interview, a diary/journal, an open questionnaire and group discussion. The emergent themes showed that mature students see education as a catalyst for change in their lives and feel a tremendous pressure to succeed. With the multiple roles they have to juggle there is not enough time in the day to accomplish all the tasks to the high standard they expect of themselves. These compromises leave the women experiencing feelings of guilt, which seems to be expressed as anxiety about the academic demands of the programme. However, experience of life and the world of work is stated as one of the great advantages of being a mature student, and one that adds to their level of confidence as they prepare to qualify and enter the workforce. Copyright © 2000 Whurr Publishers Ltd.
Enhancing graduate supervision in occupational therapy education through alternative delivery
Authors: Rodger Sylvia , Brown G. Ted
Published: March 2006

Sophisticated information technology systems have made distance education both possible and highly desirable. Distance graduate research degrees have contributed to the globalization of occupational therapy research. An exploratory study using qualitative methodology was conducted to further understand the perspectives of four distance students and three supervisors. All students perceived many personal and professional advantages in undertaking graduate study by distance; however, they acknowledged a number of challenges, such as social isolation and lack of access to resources. Supervisors and students identified issues relating to the university bureaucracy, infrastructure, time and isolation. A number of supports that promote successful graduate education were identified, including associate supervisors, on‐campus residency and informal social networks. Students and supervisors needed excellent time management and communication skills, and a commitment to maintaining contact. Students needed to balance multiple demands and supervisors needed to be student advocates. The small sample size in this study limits generalizability of the findings. Further research into methods of optimizing the use of information technology is required. An awareness of the issues and challenges is essential if graduate distance education is to be a mutually beneficial experience for supervisors and students. Copyright © 2000 Whurr Publishers Ltd.
Clinical reasoning and the occupational therapy curriculum
Authors: Liu Karen P. Y. , Chan Chetwyn C. H. , Hui‐Chan Christina W. Y.
Published: March 2006

Several reasoning styles are used by occupational therapists when they evaluate clients' problems. This study investigated the influence of the occupational therapy curriculum in Hong Kong on therapists' clinical reasoning styles. Two groups of therapists with different clinical experience were recruited. Through interviews with the therapists after identifying clients' problems using the Canadian Occupational Performance Measure, their clinical reasoning styles were explored. The local occupational therapy curriculum was analysed to isolate the components that influence clinical reasoning. Results showed that more experienced therapists use conditional reasoning that considers clients' needs in their future lives whereas junior therapists use procedural reasoning that focuses on clients' disabilities. The analysis of the occupational therapy curriculum indicated that it prepared the students with an equal emphasis on theoretical and clinical subjects and fieldwork practice. The present curriculum was useful in providing educational preparation for novice therapists. However, the period of fieldwork practice can be lengthened to allow adequate maturation of clinical reasoning skills. Problem‐based learning can be incorporated to facilitate students' problem‐solving and self‐directed learning skills. Copyright © 2000 Whurr Publishers Ltd.
A winning merger: when entry‐level and continuing education courses get together
Authors: Friedland Judith , Rappolt Susan , Mullan Liz , Ballon Anna
Published: March 2006

In this short report the viability of providing the same course to entry‐level and continuing education students is examined. The analysis of course evaluations, responses to a survey six months later, and the instructor's narrative indicated that the course was successful for both sets of students. Survey responses from the seven students and 11 practitioners revealed that both groups benefited from the combined format, and suggested methods for improvement in delivery. As demands for continuing education to meet the college's regulatory requirements increase and university budgets decrease, the potential to provide enhanced learning in this format is worthy of further research. Copyright © 2000 Whurr Publishers Ltd.
Client outcomes after student community fieldwork in Russia
Authors: Packer Tanya L. , Paterson Margo , Krupa Terry , Avtchoukhova Lioudmila , Tchebotareva Ludmila , Krasnova Lioudmila
Published: March 2006

This short report outlines how occupational therapy education was introduced in Russia in 1996 through a partnership between Canadian and Russian academic organizations and consumer groups. Role‐emerging placements were selected as a strategy to provide clinical experience in a healthcare system where there were no established occupational therapists. Students' ability to help clients to improve their occupational performance was evaluated through a record audit when the second cohort of students had completed their training. Thirty‐one files of clients aged 6 to 80 were reviewed. Clients' ratings of performance and satisfaction scores on the Canadian Occupational Performance Measure before and after occupational therapy intervention were examined. Analysis using the Wilcoxon signed rank test showed highly significant differences (p=0.001), indicating that students were able to help clients to improve their occupational performance. This is also interpreted as an indication of the success of the education programme. Copyright © 2000 Whurr Publishers Ltd.
Occupational therapy as an academic discipline in Finland
Authors: Kolehmainen Anne , Pikkarainen Aila , Aittomäki Satu
Published: March 2006

The aim of this short report is to outline the relation between Finnish educational policy and the dualistic educational structure of Finland, to describe the consequences of this system for education in occupational therapy at university level, and to speculate on the likely development and challenges facing academic occupational therapy education in the future. The authors have been involved in the development process. Copyright © 2000 Whurr Publishers Ltd.
An in‐service part‐time undergraduate programme for occupational therapy support workers
Authors: Douglas Fiona M
Published: March 2006

This short report outlines the success of an undergraduate programme designed specifically for mature students' participation while they continue with their work as occupational therapy support workers. The programme was established to meet a local need. Copyright © 2000 Whurr Publishers Ltd.
Perceptual, motor and cognitive performance components of Bedouin children in Israel
Authors: Parush Shula , Sharoni Chaya , Hahn‐Markowitz Jeri , Katz Noomi
Published: March 2006

The purpose of this study was to evaluate the perceptual, motor and cognitive performance abilities of Bedouin children as compared with mainstream Israeli children of the same age. The study population comprised two age groups (6–8 year olds and 10–12 year olds) living in two different types of settlements (rural and town). Participants included 20 children in each group. The Test of Visual‐Perceptual Skills (TVPS), the Developmental Test of Visual‐Motor Integration (VMI), selected subtests from the Bruininks‐Oseretsky Test of Motor Proficiency and the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) were used. Older participants in all three groups performed better than the younger subjects. There were no significant differences between the two Bedouin groups in either age category. The mainstream Israeli subjects scored significantly higher than the two Bedouin groups on most variables tested. The lack of differences between the two Bedouin groups may indicate that the transition from nomadic communities to urban communities is mainly external and has not caused a significant change in perception, perceptual‐motor and cognitive performance abilities. The results of this study may be used as a base for developing preventive intervention programmes to meet the specific needs of Bedouin children. A limitation of this study was the classification of the Bedouin population according to their dwelling place and not according to their sociodemographic background, such as parents' economic status, parents' education and so on. Recommendations for future research include expanding the number of participants, including children from additional rural schools of various distant tribes and incorporating more detailed cognitive assessments. Copyright © 2000 Whurr Publishers Ltd.
Developing a measure of beliefs and attitudes about chronic non‐malignant pain: a pilot study of occupational therapists
Authors: Jones Derek , Ravey John , Steedman Wilma
Published: March 2006

The paper reports the results from the early stages of the development of an instrument to measure professionals' beliefs and attitudes on chronic non‐malignant pain, and assesses the instrument's use in measuring the effectiveness of education. British state‐registered occupational therapists (n=19) were surveyed, using a pilot instrument designed by one of the researchers, before and after a twoday course in the management of chronic non‐malignant pain led by a psychologist and two occupational therapists. Results show a statistically significant change in scores after education, indicating a positive change in beliefs and attitudes. Implications for future research are briefly discussed. The limitations of the study are the small sample size and the early stage in development of the instrument used. Further research will be aimed at improving the validity and reliability of the instrument using a larger multidisciplinary sample. Copyright © 2000 Whurr Publishers Ltd.
Cross‐cultural assessment of the Contextual Memory Test (CMT)
Authors: Josman Naomi , Hartman‐Maeir Adina
Published: March 2006

The Contextual Memory Test (CMT) measures aspects of memory and metamemory of people with cognitive disabilities. The assessment tool was originally developed and standardized in the United States. The objectives of this study were: (1) to evaluate the applicability of the CMT to an Israeli population; (2) to further investigate the construct validity of the CMT to discriminate among age groups; and (3) to analyse the 40 items on the CMT from a cultural point of view. The CMT was administered to 217 typical Israeli adults, grouped into three age categories, closely matching those in the US normative study (Toglia, 1993). Similar levels of performance were obtained for Israelis and Americans on the various test components. Statistically significant differences between American and Israeli subjects' performance levels were evident in three memory components in the elderly groups (group 3) and in only two memory components in the young group (group 1). In addition, within‐sample comparisons of the three Israeli age groups yielded significant age effects for recall, recognition, strategy use and general awareness. This study confirmed discriminant validity for the CMT. The tool seems to be highly appropriate for use by occupational therapists in assessing memory and metamemory with American and Israeli adult subjects. The relatively small size of the age groups and the lack of random selection of subjects are limitations of this study. Therefore, it is recommended that the study be replicated with a larger and randomized sample. The multifaceted nature of the assessment provides much more information than traditional recall scores, and the metamemory components enhance both differential diagnosis and appropriate planning of treatment. Copyright © 2000 Whurr Publishers Ltd.
The impact of child abuse on children's play: a conceptual model
Authors: Cooper Rodney J.
Published: March 2006

The purpose of this article is to examine critically the impact of child abuse on children's play, using a descriptive model of children's play as a conceptual framework for this review of the literature. Play is recognized as a primary occupation of childhood by occupational therapists. When a child is exposed to an abusive or neglectful care environment his or her play development may be disrupted. Although the detrimental effects of physical, sexual or emotional abuse and neglect are well documented, relatively few studies have investigated the play of abused children. Reported effects suggest that abused or neglected children are more likely to show developmentally delayed play skills, decreased playfulness and behavioural disturbance in their play, which may place them at greater risk for learning and social problems. Occupational therapists often use play, including play therapy, to assess and treat abused children. This analysis highlights the need for occupational therapists to evaluate how play‐based therapeutic approaches can best meet the developmental and emotional needs of abused and neglected children. Recommendations are made for occupational therapists to be more knowledgeable about child abuse and to address the need for research into the specific effects of child abuse on children's play. Copyright © 2000 Whurr Publishers Ltd.
Psychiatric occupational therapists' verbal interaction with their clients
Authors: Eklund Mona , Hallberg Ingalill Rahm
Published: March 2006

This study reports from a survey investigating psychiatric occupational therapists' (n=292) use of verbal interaction on a regular basis with their clients. Among predefined areas of verbal interaction, routine occupations, self‐image and ego‐strengthening interventions were among the most frequently given alternatives. Verbal interaction with clients was more common among occupational therapists in outpatient care than among those in inpatient care. Verbal interaction with clients was also more common among occupational therapists with advanced education in psychodynamically oriented psychotherapy. The respondents' use of theoretical frames of reference was related to the focus of their verbal interaction with clients. Interventions to reach certain goals emerged as the most common category of verbal interactions. It was concluded that verbal interaction with clients is essential to the occupational therapy process. Future research needs to investigate the interplay between verbal and non‐verbal components of interaction in occupational therapy and how patients benefit from these elements. Copyright © 2001 Whurr Publishers Ltd.