bluuebunny/crossref_metadata_2025 huggingface dataset:
Thalamocortical Conduction Times and Stimulus-Evoked Responses in the Rat Whisker-to-Barrel System
Authors: Simons Daniel J. , Carvell George E. , Kyriazi Harold T. , Bruno Randy M.
Published: September 2007

Studies of the rodent whisker system indicate that somatosensory cortical circuitry operates at a millisecond timescale to transform sensory afferent signals from the thalamus. We measured axon conduction times and whisker-evoked responses of 48 thalamocortical (TC) neurons in the rat whisker-to-barrel pathway. Conduction times were derived from spike-triggered averages of local field potentials evoked in layer 4 cortical whisker-related barrels by the spontaneous firing of individual topographically aligned neurons in the ventral posterior medial thalamus. Conduction times varied fourfold, from 0.31 to 1.34 ms, and faster conducting TC neurons responded earlier and more robustly to controlled whisker deflections. Early arrival of highly responsive TC inputs, thought to contact inhibitory barrel neurons preferentially, could prime the cortical network, rendering it more selective for later-arriving signals.
Primer extension-based method for the generation of a siRNA/miRNA expression vector
Authors: Gou Deming , Zhang Honghao , Baviskar Pradyumna S. , Liu Lin
Published: September 2007

RNA interference (RNAi) has become a powerful technique for studying gene function, biological pathways, and the physiology of diseases. Typically, the RNAi response in mammalian cells is mediated by small interfering RNA (siRNA). The use of synthesized siRNA to silence gene is relatively quick and easy, but it is costly with transient effects. A short hairpin RNA (shRNA) with complementary sense and antisense sequences of a target gene separated by a loop structure results in gene silencing that is as effective as chemically synthesized siRNA with fewer limitations. However, current methods for constructing shRNA vectors require the synthesis of long oligonucleotides, which is costly and often suffers from mutation problems during synthesis. Here, we report an alternative approach to generate a shRNA expression vector with high efficacy. We utilized shorter (≤50-nucleotide) primers to generate a shRNA insert by the primer extension method. Our new approach for the construction of shRNA expression vectors dramatically reduced the possibility of mutations. Using this method, we constructed a microRNA (miRNA) library, which facilitates the expression of 254 matured miRNAs. We also performed high-throughput screening of miRNAs involved in the regulation of human Survivin promoter activity in lung A549 cells. We found that the expression of miR-192, 199a, 19a, 20a, 213, and 371 caused the activation of the Survivin promoter whereas miR-302b*, 34a, 98, 381, 463 and 471 decreased the Survivin promoter activity.
Transcriptional pathways associated with skeletal muscle disuse atrophy in humans
Authors: Chen Yi-Wen , Gregory Chris M. , Scarborough Mark T. , Shi Rongye , Walter Glenn A. , Vandenborne Krista
Published: September 2007

Disuse atrophy is a common clinical phenomenon that significantly impacts muscle function and activities of daily living. The purpose of this study was to implement genome-wide expression profiling to identify transcriptional pathways associated with muscle remodeling in a clinical model of disuse. Skeletal muscle biopsies were acquired from the medial gastrocnemius in patients with an ankle fracture and from healthy volunteers subjected to 4–11 days of cast immobilization. We identified 277 misregulated transcripts in immobilized muscles of patients, of which the majority were downregulated. The most broadly affected pathways were involved in energy metabolism, mitochondrial function, and cell cycle regulation. We also found decreased expression in genes encoding proteolytic proteins, calpain-3 and calpastatin, and members of the myostatin and IGF-I pathway. Only 26 genes showed increased expression in immobilized muscles, including apolipoprotein (APOD) and leptin receptor (LEPR). Upregulation of APOD (5.0-fold, P < 0.001) and LEPR (5.7-fold, P < 0.05) was confirmed by quantitative RT-PCR and immunohistochemistry. In addition, atrogin-1/MAFbx was found to be 2.4-fold upregulated ( P < 0.005) by quantitative RT-PCR. Interestingly, 96% of the transcripts differentially regulated in immobilized limbs also showed the same trend of change in the contralateral legs of patients but not the contralateral legs of healthy volunteers. Information obtained in this study complements findings in animal models of disuse and provides important feedback for future clinical studies targeting the restoration of muscle function following limb disuse in humans.
Sliver Solar Cells: High-Efficiency, Low-Cost PV Technology
Authors: Franklin Evan , Everett Vernie , Blakers Andrew , Weber Klaus
Published: September 2007

Sliver cells are thin, single-crystal silicon solar cells fabricated using standard fabrication technology. Sliver modules, composed of several thousand individual Sliver cells, can be efficient, low-cost, bifacial, transparent, flexible, shadow tolerant, and lightweight. Compared with current PV technology, mature Sliver technology will need 10% of the pure silicon and fewer than 5% of the wafer starts per MW of factory output. This paper deals with two distinct challenges related to Sliver cell and Sliver module production: providing a mature and robust Sliver cell fabrication method which produces a high yield of highly efficient Sliver cells, and which is suitable for transfer to industry; and, handling, electrically interconnecting, and encapsulating billions of sliver cells at low cost. Sliver cells with efficiencies of 20% have been fabricated at ANU using a reliable, optimised processing sequence, while low-cost encapsulation methods have been demonstrated using a submodule technique.
Fuzzy Logic Control of Adaptive ARQ for Video Distribution over a Bluetooth Wireless Link
Authors: Razavi R. , Fleury M. , Ghanbari M.
Published: September 2007

Bluetooth's default automatic repeat request (ARQ) scheme is not suited to video distribution resulting in missed display and decoded deadlines. Adaptive ARQ with active discard of expired packets from the send buffer is an alternative approach. However, even with the addition of cross-layer adaptation to picture-type packet importance, ARQ is not ideal in conditions of a deteriorating RF channel. The paper presents fuzzy logic control of ARQ, based on send buffer fullness and the head-of-line packet's deadline. The advantage of the fuzzy logic approach, which also scales its output according to picture type importance, is that the impact of delay can be directly introduced to the model, causing retransmissions to be reduced compared to all other schemes. The scheme considers both the delay constraints of the video stream and at the same time avoids send buffer overflow. Tests explore a variety of Bluetooth send buffer sizes and channel conditions. For adverse channel conditions and buffer size, the tests show an improvement of at least 4 dB in video quality compared to nonfuzzy schemes. The scheme can be applied to any codec with I-, P-, and (possibly) B-slices by inspection of packet headers without the need for encoder intervention.
A Full Automatic Device for Sampling Small Solution Volumes in Photometric Titration Procedure Based on Multicommuted Flow System
Authors: Borges Sivanildo S. , Vieira Gláucia P. , Reis Boaventura F.
Published: September 2007

In this work, an automatic device to deliver titrant solution into a titration chamber with the ability to determine the dispensed volume of solution, with good precision independent of both elapsed time and flow rate, is proposed. A glass tube maintained at the vertical position was employed as a container for the titrant solution. Electronic devices were coupled to the glass tube in order to control its filling with titrant solution, as well as the stepwise solution delivering into the titration chamber. The detection of the titration end point was performed employing a photometer designed using a green LED (λ= 545 nm) and a phototransistor. The titration flow system comprised three-way solenoid valves, which were assembled to allow that the steps comprising the solution container loading and the titration run were carried out automatically. The device for the solution volume determination was designed employing an infrared LED (λ= 930 nm) and a photodiode. When solution volume delivered from proposed device was within the range of 5 to 105μl, a linear relationship (R = 0.999) between the delivered volumes and the generated potential difference was achieved. The usefulness of the proposed device was proved performing photometric titration of hydrochloric acid solution with a standardized sodium hydroxide solution and using phenolphthalein as an external indicator. The achieved results presented relative standard deviation of 1.5%.
In Vivo Evaluation of the Nitroimidazole‐Based Thioflavin‐T Derivatives as Cerebral Ischemia Markers
Authors: Chu Taiwei , Li Zejun , Liu Xinqi , Wang Xiangyun
Published: September 2007

Timely imaging and accurate interpretation of cerebral ischemia are required to
identify patients who might benefit from more aggressive therapy, and nuclear medicine
offers a noninvasive method for demonstrating cerebral ischemia. Three
nitroimidazole‐based thioflavin‐T derivatives, N‐[4‐(benzothiazol‐2‐yl)phenyl]‐3‐(4‐nitroimidazole‐1‐yl) propanamide (4NPBTA), N‐[4‐(benzothiazol‐2‐yl)phenyl]‐3‐(4‐nitroimidazole‐1‐yl)‐N‐methylpropanamide (4NPBTA‐1), and
N‐[4‐(benzothiazol‐2‐yl)phenyl]‐3‐(2‐nitroimidazole‐1‐yl) propanamide (2NPBTA), were
radioiodinated and evaluated as possible cerebral ischemia markers. In normal mice,
these compounds showed good permeation of the intact blood‐brain barrier (BBB), high
initial brain uptake, and rapid washout. In gerbil stroke models that had been subjected
to right common carotid artery ligation to produce cerebral ischemia, [I131]2NPBTA,
uptake in the right cerebral hemisphere decreased more slowly than that of the left, and
the right/left hemisphere uptake ratios increased with time. Also, the right/left
hemisphere uptake ratios correlated positively with the severity of the stroke. The results showed that
[I131]2NPBTA had a specific location in the cerebral ischemic tissue. This represented a first step in finding new drugs and might provide a possible cerebral
ischemic marker.
Folding and Unfolding in the Blue Copper Protein Rusticyanin: Role of the Oxidation State
Authors: Alcaraz Luis A. , Gómez Javier , Ramírez Pablo , Calvente Juan J. , Andreu Rafael , Donaire Antonio
Published: September 2007

The unfolding process of the blue copper protein rusticyanin has been studied from the structural and the thermodynamic points of view at two pH values (pH 2.5 and 7.0). When Rc unfolds, copper ion remains bound to the polypeptide chain. Nuclear magnetic resonance data suggest that three of the copper ligands in the folded state are bound to the metal ion in the unfolded form, while the other native ligand is detached. These structural changes are reflected in the redox potentials of the protein in both folded and unfolded forms. The affinities of the copper ion in both redox states have been also determined at the two specified pH values. The results indicate that the presence of two histidine ligands in the folded protein can compensate the change in the net charge that the copper ion receives from their ligands, while, in the unfolded protein, charges of aminoacids are completely transferred to the copper ion, altering decisively the relative stability of its two-redox states.
Electromagnetic Field Behavior in Dispersive Isotropic Negative Phase Velocity/Negative Refractive Index Guided Wave Structures Compatible with Millimeter-Wave Monolithic Integrated Circuits
Authors: Krowne Clifford M. , Daniel Maurice
Published: September 2007

A microstrip configuration has been loaded with a dispersive isotropic left-handed medium (LHM) substrate and studied regarding its high frequency millimeter-wave behavior near 100 GHz. This has been accomplished using a full-wave integral-equation anisotropic Green's function code configured to run for isotropy. Never before seen electromagnetic field distributions are produced, unlike anything found in normal media devices, using this ab initio solver. These distributions are made in the cross-sectional dimension, with the field propagating in the perpendicular direction. It is discovered that the LHM distributions are so radically different from ordinary media used as a substrate that completely new electronic devices based upon the new physics become a real possibility. The distinctive dispersion diagram for the dispersive medium, consisting of unit cells with split ring resonator-rod combinations, is provided over the upper millimeter-wave frequency regime.
Cross-Layer Design of Source Rate Control and Congestion Control for Wireless Video Streaming
Authors: Zhu Peng , Zeng Wenjun , Li Chunwen
Published: September 2007

Cross-layer design has been used in streaming video over the wireless channels to optimize the overall system performance. In this paper, we extend our previous work on joint design of source rate control and congestion control for video streaming over the wired channel, and propose a cross-layer design approach for wireless video streaming. First, we extend the QoS-aware congestion control mechanism (TFRCC) proposed in our previous work to the wireless scenario, and provide a detailed discussion about how to enhance the overall performance in terms of rate smoothness and responsiveness of the transport protocol. Then, we extend our previous joint design work to the wireless scenario, and a thorough performance evaluation is conducted to investigate its performance. Simulation results show that by cross-layer design of source rate control at application layer and congestion control at transport layer, and by taking advantage of the MAC layer information, our approach can avoid the throughput degradation caused by wireless link error, and better support the QoS requirements of the application. Thus, the playback quality is significantly improved, while good performance of the transport protocol is still preserved.
Silicon Quantum Dots in a Dielectric Matrix for All-Silicon Tandem Solar Cells
Authors: Cho Eun-Chel , Green Martin A. , Conibeer Gavin , Song Dengyuan , Cho Young-Hyun , Scardera Giuseppe , Huang Shujuan , Park Sangwook , Hao X.  J. , Huang Yidan , Van Dao Lap
Published: September 2007

We report work progress on the growth of Si quantum dots in different matrices for future photovoltaic applications. The work reported here seeks to engineer a wide-bandgap silicon-based thin-film material by using quantum confinement in silicon quantum dots and to utilize this in complete thin-film silicon-based tandem cell, without the constraints of lattice matching, but which nonetheless gives an enhanced efficiency through the increased spectral collection efficiency. Coherent-sized quantum dots, dispersed in a matrix of silicon carbide, nitride, or oxide, were fabricated by precipitation of Si-rich material deposited by reactive sputtering or PECVD. Bandgap opening of Si QDs in nitride is more blue-shifted than that of Si QD in oxide, while clear evidence of quantum confinement in Si quantum dots in carbide was hard to obtain, probably due to many surface and defect states. The PL decay shows that the lifetimes vary from 10 to 70 microseconds for diameter of 3.4 nm dot with increasing detection wavelength.
A Global Convergence Result for a Higher Order Difference Equation
Authors: Iricanin Bratislav D.
Published: September 2007

Letf(z1,…,zk)∈C(Ik,I)be a given function, whereIis (bounded or unbounded) subinterval ofℝ, andk∈ℕ. Assume thatf(y1,y2,…,yk)≥f(y2,…,yk,y1)ify1≥max{y2,…,yk},f(y1,y2,…,yk)≤f(y2,…,yk,y1)ify1≤min{y2,…,yk}, andfis non- decreasing in the last variablezk. We then prove that every bounded solution of an autonomous difference equation of orderk, namely,xn=f(xn−1,…,xn−k),n=0,1,2,…,with initial valuesx−k,…,x−1∈I, is convergent, and every unbounded solution tends either to+∞or to−∞.
High-Efficiency Crystalline Silicon Solar Cells
Authors: Glunz S. W.
Published: September 2007

The current cost distribution of a crystalline silicon PV module is clearly dominated by material costs, especially by the costs of the silicon wafer. Therefore cell designs that allow the use of thinner wafers and the increase of energy conversion efficiency are of special interest to the PV industry. This article gives an overview of the most critical issues to achieve this aim and of the recent activities at Fraunhofer ISE and other institutes.
Glutathione Peroxidase 3, Deleted or Methylated in Prostate Cancer, Suppresses Prostate Cancer Growth and Metastasis
Authors: Yu Yan P. , Yu Guoying , Tseng George , Cieply Kathleen , Nelson Joel , Defrances Marie , Zarnegar Reza , Michalopoulos George , Luo Jian-Hua
Published: September 2007

Glutathione peroxidase 3 is a selenium-dependent enzyme playing a critical role in detoxifying reactive oxidative species and maintaining the genetic integrity of mammalian cells. In this report, we found that the expression of glutathione peroxidase 3 (GPx3) was widely inactivated in prostate cancers. Complete inactivation of GPx3 correlates with a poor clinical outcome. Deletions (hemizygous and homozygous) of GPx3 gene are frequent in prostate cancer samples, occurring in 39% of the samples studied. The rate of methylation of the GPx3 exon 1 region in prostate cancer samples reaches 90%. Overexpression of GPx3 in prostate cancer cell lines induced the suppression of colony formation and anchorage-independent growth of PC3, LNCaP, and Du145 cells. PC3 cells overexpressing GPx3 reduced invasiveness in Matrigel transmigration analysis by an average of 2.7-fold. Xenografted PC3 cells expressing GPx3 showed reduction in tumor volume by 4.8-fold, elimination of metastasis (0/16 versus 7/16), and reduction of animal death (3/16 versus 16/16). The tumor suppressor activity of GPx3 seems to relate to its ability to suppress the expression of c-met. The present findings suggest that GPx3 is a novel tumor suppressor gene. [Cancer Res 2007;67(17):8043–50]
Strong Evidence of a Genetic Determinant for Mammographic Density, a Major Risk Factor for Breast Cancer
Authors: Vachon Celine M. , Sellers Thomas A. , Carlson Erin E. , Cunningham Julie M. , Hilker Christopher A. , Smalley Regenia L. , Schaid Daniel J. , Kelemen Linda E. , Couch Fergus J. , Pankratz V. Shane
Published: September 2007

Increased mammographic density (MD), the proportion of dense tissue visible on a mammogram, is a strong risk factor for breast cancer, common in the population and clusters in families. We conducted the first genome-wide linkage scan to identify genes influencing MD. DNA was obtained from 889 relatives (756 women, 133 men) from 89 families. Percent MD was estimated on 618 (82%) female family members using a validated computer-assisted thresholding method. The genome-wide scan included 403 microsatellite DNA markers with an average spacing of 9 cM. Fine mapping of a region of chromosome 5p (5p13.1-5p15.1) was done using 21 additional closely spaced DNA markers. Linkage analyses were conducted to quantify the evidence for a gene responsible for MD across the genome. The maximum log odds for linkage (LOD) score from the genome-wide scan was on chromosome 5p (LOD = 2.9, supporting linkage by a factor of 102.9 or 794 to 1) with a 1-LOD interval spanning 28.6 cM. Two suggestive regions for linkage were also identified on chromosome 12 (LOD = 2.6, 1-LOD interval of 14.8 cM; and LOD = 2.5, 1-LOD interval of 17.2 cM). Finer mapping of the region surrounding the maximum LOD on chromosome 5p resulted in stronger and statistically significant evidence for linkage (LOD = 4.2) and a narrowed 1-LOD interval (13.4 cM). The putative locus on chromosome 5p is likely to account for up to 22% of variation in MD. Hence, 1 or more of the 45 candidate genes in this region could explain a large proportion of MD and, potentially, breast cancer. [Cancer Res 2007;67(17):8412–8]
Down-regulation of Forkhead Box M1 Transcription Factor Leads to the Inhibition of Invasion and Angiogenesis of Pancreatic Cancer Cells
Authors: Wang Zhiwei , Banerjee Sanjeev , Kong Dejuan , Li Yiwei , Sarkar Fazlul H.
Published: September 2007

The Forkhead Box M1 (FoxM1) transcription factor has been shown to play important roles in regulating the expression of genes involved in cell proliferation, differentiation, and transformation. Overexpression of FoxM1 has been found in a variety of aggressive human carcinomas including pancreatic cancer. However, the precise role and the molecular mechanism of action of FoxM1 in pancreatic cancer remain unclear. To elucidate the cellular and molecular function of FoxM1, we tested the consequences of down-regulation and up-regulation of FoxM1 in pancreatic cancer cells, respectively. Using multiple cellular and molecular approaches such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, gene transfection, flow cytometry, real-time reverse transcription-PCR, Western blotting, migration, invasion, and angiogenesis assays, we found that down-regulation of FoxM1 inhibited cell growth, decreased cell migration, and decreased invasion of pancreatic cancer cells. FoxM1 down-regulation also decreased cell population in the S phase. Compared with control, FoxM1 small interfering RNA–transfected cells showed decreased expression of cyclin B, cyclin D1, and Cdk2, whereas p21 and p27 expression was increased. We also found that down-regulation of FoxM1 reduced the expression of matrix metalloproteinase-2 (MMP-2), MMP-9 and vascular endothelial growth factor, resulting in the inhibition of migration, invasion, and angiogenesis. These findings suggest that FoxM1 down-regulation could be a novel 1:49 AM 8/29/2007approach for the inhibition of pancreatic tumor progression. [Cancer Res 2007;67(17):8293–300]
NAC-1 Controls Cell Growth and Survival by Repressing Transcription of Gadd45GIP1, a Candidate Tumor Suppressor
Authors: Nakayama Kentaro , Nakayama Naomi , Wang Tian-Li , Shih Ie-Ming
Published: September 2007

Cancer mortality and morbidity are primarily related to recurrent tumors, and characterization of recurrence-associated genes should illuminate fundamental properties of tumor progression and provide new therapeutic targets. We have previously identified NAC-1, a member of the BTB/POZ gene family and a transcription repressor, as a gene associated with recurrent ovarian carcinomas after chemotherapy. We further showed that homodimerization of NAC-1 proteins is essential for tumor growth and survival. In this study, we applied serial analysis of gene expression and identified growth arrest and DNA-damage–inducible 45-γ interacting protein (Gadd45GIP1) as one of the downstream genes negatively regulated by NAC-1. NAC-1 knockdown in both SKOV3 and HeLa cells that expressed abundant endogenous NAC-1 induced Gadd45GIP1 expression transcriptionally; on the other hand, engineered expression of NAC-1 in NAC-1–negative RK3E and HEK293 cells suppressed endogenous Gadd45GIP1 expression. In NAC-1–expressing tumor cells, induction of dominant negative NAC-1 conferred a growth-inhibitory effect that can be partially reversed by Gadd45GIP1 knockdown. Induced Gadd45GIP1 expression resulted in growth arrest in SKOV3 and HeLa cells both in vitro and in vivo. In summary, NAC-1 contributes to tumor growth and survival by at least inhibiting Gadd45GIP1 expression, which has a tumor suppressor effect in cancer cells. [Cancer Res 2007;67(17):8058–64]
Crystal Structure of the T315I Abl Mutant in Complex with the Aurora Kinases Inhibitor PHA-739358
Authors: Modugno Michele , Casale Elena , Soncini Chiara , Rosettani Pamela , Colombo Riccardo , Lupi Rosita , Rusconi Luisa , Fancelli Daniele , Carpinelli Patrizia , Cameron Alexander D. , Isacchi Antonella , Moll Jürgen
Published: September 2007

Mutations in the kinase domain of Bcr-Abl are the most common cause of resistance to therapy with imatinib in patients with chronic myelogenous leukemia (CML). Second-generation Bcr-Abl inhibitors are able to overcome most imatinib-resistant mutants, with the exception of the frequent T315I substitution, which is emerging as a major cause of resistance to these drugs in CML patients. Structural studies could be used to support the drug design process for the development of inhibitors able to target the T315I substitution, but until now no crystal structure of the T315I Abl mutant has been solved. We show here the first crystal structure of the kinase domain of Abl T315I in complex with PHA-739358, an Aurora kinase inhibitor currently in clinical development for solid and hematologic malignancies. This compound inhibits in vitro the kinase activity of wild-type Abl and of several mutants, including T315I. The cocrystal structure of T315I Abl kinase domain provides the structural basis for this activity: the inhibitor associates with an active conformation of the kinase domain in the ATP-binding pocket and lacks the steric hindrance imposed by the substitution of threonine by isoleucine. [Cancer Res 2007;67(17):7987–90]
A Dual Phosphoinositide-3-Kinase α/mTOR Inhibitor Cooperates with Blockade of Epidermal Growth Factor Receptor in PTEN-Mutant Glioma
Authors: Fan Qi-Wen , Cheng Christine K. , Nicolaides Theodore P. , Hackett Christopher S. , Knight Zachary A. , Shokat Kevan M. , Weiss William A.
Published: September 2007

We have shown previously that blockade of epidermal growth factor receptor (EGFR) cooperates with a pan-selective inhibitor of phosphoinositide-3-kinase (PI3K) in EGFR-driven glioma. In this communication, we tested EGFR-driven glioma differing in PTEN status, treating with the EGFR inhibitor erlotinib and a novel dual inhibitor of PI3Kα and mTOR (PI-103). Erlotinib blocked proliferation only in PTENwt cells expressing EGFR. Although erlotinib monotherapy showed little effect in PTENmt glioma, PI-103 greatly augmented the antiproliferative efficacy of erlotinib in this setting. To address the importance of PI3K blockade, we showed in PTENmt glioma that combining PI-103 and erlotinib was superior to either monotherapy or to therapy combining erlotinib with either rapamycin (an inhibitor of mTOR) or PIK-90 (an inhibitor of PI3Kα). These experiments show that a dual inhibitor of PI3Kα and mTOR augments the activity of EGFR blockade, offering a mechanistic rationale for targeting EGFR, PI3Kα, and mTOR in the treatment of EGFR-driven, PTEN-mutant glioma. [Cancer Res 2007;67(17):7960–5]
Postoperative Brain Stem Tension Pneumocephalus Causing Transient Locked-In Syndrome
Authors: Biyani N. , Silbiger A. , Ben-Ari J. , Constantini S.
Published: September 2007

The incidence of pneumocephalus after supratentorial craniotomy has been reported to be as high as 100%. However, transformation of postoperative pneumocephalus into tension pneumocephalus (symptomatic intracranial air) is a rather rare phenomenon. Tension pneumocephalus after posterior fossa surgery is reported mainly when the surgery is performed in a sitting position. We hereby report on a patient who developed brain-stem tension pneumocephalus in the early postoperative period after posterior fossa craniotomy for an exophytic brainstem astrocytoma, operated in the prone position. A complete locked-in syndrome resolved following surgical relief of the trapped air.
Intracerebral Sewing Needle
Authors: Yolas C. , Aydın M.D. , Ozdikici M. , Aydın N. , Onder A.
Published: September 2007

A 9-year-old male patient complaining of seizure attack was admitted to the neurosurgery department. Radiologic investigations revealed a 5-cm-long metallic sewing needle extending from the right frontal cortex to the right lateral ventricle. Burr hole surgery was performed and the needle was grasped with biopsy forceps and removed with endoscopic guidance. The patient recovered without any complications.
Routine Use of Gastrograffin Enema prior to the Reversal of a Loop Ileostomy
Authors: Khair G. , Alhamarneh O. , Avery J. , Cast J. , Gunn J. , Monson J.R.T. , Hartley J.
Published: September 2007

Background/Aims: Anastomotic failure occurs in up to 10% of patients following anterior resection. Selective use of a loop ileostomy may reduce the septic consequences of anastomotic leak. The use of gastrograffin enema to confirm the anastomotic integrity prior to ileostomy closure is still controversial. Our aim was to determine the impact of the routine use of gastrograffin enema on patients’ management prior to ileostomy reversal. Methods: A review of 81 patients who underwent low anterior resection with loop ileostomy for rectal cancer over 3 years. Results: Gastrograffin enema was performed in 69 patients (85.2%). The mean time from operation to gastrograffin enema was 22 weeks. Four patients (5.8%) had a positive radiological leak without clinical suspicion of anastomotic problems, 2 patients (2.9%) of these subsequently had the ileostomy closed despite the positive result, 2 patients (2.9%) had a gastrograffin enema repeated which showed no leak and the patients are awaiting reversal. Conclusion: The incidence of positive radiological leak in uncomplicated patients is low; such patients had their loop ileostomies closed with or without serial gastrograffin enema. Routine gastrograffin enema in the absence of a clinical suspicion of anastomotic failure would appear to be of little value.
Slow Intravenous Iron Administration Does Not Aggravate Oxidative Stress and Inflammatory Biomarkers during Hemodialysis: A Comparative Study between Iron Sucrose and Iron Dextran
Authors: Malindretos Pavlos , Sarafidis Pantelis A. , Rudenco Igor , Raptis Vasilios , Makedou Kali , Makedou Areti , Grekas Dimirios M.
Published: September 2007

Background/Aims: Fast intravenous (i.v.) iron administration during hemodialysis (HD) is associated with the augmentation of oxidative stress and the increase in inflammatory biomarkers, which are also induced by the hemodialysis procedure itself. The aim of this study was to investigate if slow i.v. iron administration would aggravate the status of oxidative stress and inflammatory biomarkers during a hemodialysis session. Methods: Twenty dialysis patients 30–92 years of age that were iron replete and had values for hemoglobin, transferrin saturation and serum ferritin among recommended goals were evaluated in three separate hemodialysis sessions. In the first session patients did not receive any iron treatment, whereas during the second and the third session patients received slow (60 min) i.v. infusions of 100 mg of iron sucrose and 100 mg of iron dextran, respectively. Blood samples were drawn before the hemodialysis session, 15 min after the end of iron administration and at the end of the hemodialysis session in all occasions, for the measurement of markers of oxidant stress (oxidized LDL and ischemia-modified albumin) and inflammation (high-sensitivity C-reactive protein, interleukin-6 and tumor necrosis factor-α). Results: Oxidized LDL was not significantly altered during hemodialysis and this pattern was similar between the three occasions studied. In contrast, ischemia-modified albumin was significantly increased and this effect was also not different between the net hemodialysis and the occasions of iron administration. High-sensitivity CRP, IL-6 and TNF-α were all significantly elevated during hemodialysis and again both types of iron administration did not produce significant changes in this pattern. Conclusion: We did not find an increase in the markers of oxidation/inflammation studied, after slow i.v. iron administration during hemodialysis session.
Antioxidant Effect of Sulphurous Thermal Water on Human Neutrophil Bursts: Chemiluminescence Evaluation
Authors: Braga Pier Carlo , Sambataro Giuseppe , Dal Sasso Monica , Culici Maria , Alfieri Marina , Nappi Giuseppe
Published: September 2007

Background: The activities of the HS (sulfhydryl or thiolic) group in the cysteine of glutathione or various low-weight soluble molecules (thiolic drugs), such as N-acethylcysteine, mesna, thiopronine and dithiotreitol or stepronine and erdosteine (prodrugs), include its antioxidant activity in the airways during the release of reactive oxygen or nitrogen species (ROS, RNS) by polymorphonuclear neutrophils (PMNs) activated in response to exogenous or endogenous stimuli. Objective: In addition to being administered by means of thiolic molecules, the HS group can also be given by means of the inhalation of sulphurous thermal water. The aim of this study was to investigate the effect of sulphurous thermal water on the release of ROS and RNS during the bursts of human PMNs. Methods: The luminol-amplified chemiluminescence methodology was used to investigate the ROS and RNS released by PMNs stimulated with N-formyl-methionyl-leucyl-phenylalanine and phorbol-12-myristate-13-acetate, before and after incubation with sulphurous water. Effects on cell-free systems were also investigated. Results: The water significantly reduced the luminol-amplified chemiluminescence of N-formyl-methionyl-leucyl-phenylalanine- andphorbol-12-myristate-13-acetate-activated PMNs on average from 0.94 to 15.5 µg/ml of HS, even after the addition of L-arginine, a nitric oxide (NO) donor. Similar findings have also been obtained in a cell-free system, thus confirming the importance of the presence of the HS group (reductive activity). Conclusions: The positive effects of the activity of sulphurous thermal waters has been partially based on the patients’ subjective sense of wellbeing and partially on not always easy to quantify symptomatic (or general) clinical improvements. Our findings indicate that, in addition to their known mucolytic activity and trophic effects on respiratory mucosa, the HS groups present in the sulphurous thermal water of this spring also have antioxidant activity that contributes to the therapeutic effects of the water in upper and lower airway inflammatory diseases.
Dynamic Calibration with an Ensemble Kalman Filter Based Data Assimilation Approach for Root-Zone Moisture Predictions
Authors: Montaldo Nicola , Albertson John D. , Mancini Marco
Published: September 2007

In the presence of uncertain initial conditions and soil hydraulic properties, land surface model (LSM) performance can be significantly improved by the assimilation of periodic observations of certain state variables, such as the near-surface soil moisture (θg), as observed from a remote platform. In this paper the possibility of merging observations and the model optimally for providing robust predictions of root-zone soil moisture (θ2) is demonstrated. An assimilation approach that assimilates θg through the ensemble Kalman filter (EnKF) and provides a physics-based update of θ2 is developed. This approach, as with other common soil moisture assimilation approaches, may fail when a key LSM parameter, for example, the saturated hydraulic conductivity (ks), is estimated poorly. This leads to biased model errors producing a violation of a main assumption (model errors with zero mean) of the EnKF. For overcoming this model bias an innovative assimilation approach is developed that accepts this violation in the early model run times and dynamically calibrates all the components of the ks ensemble as a function of the persistent bias in root-zone soil moisture, allowing one to remove the model bias, restore the fidelity to the EnKF requirements, and reduce the model uncertainty. The robustness of the proposed approach is also examined in sensitivity analyses.
A Brief Evaluation of Precipitation from the North American Regional Reanalysis
Authors: Bukovsky Melissa S. , Karoly David J.
Published: September 2007

Several aspects of the precipitation climatology from the North American Regional Reanalysis (NARR) are analyzed and compared with two other reanalyses and one set of gridded observations over a domain encompassing the United States. The spatial distribution, diurnal cycle, and annual cycle of precipitation are explored to establish the reliability of the reanalyses and to judge their usefulness. While the NARR provides a much improved representation of precipitation over that of the other reanalyses examined, some inaccuracies are found and have been highlighted as a warning to potential users of the data.
The Partitioning of Evapotranspiration into Transpiration, Soil Evaporation, and Canopy Evaporation in a GCM: Impacts on Land–Atmosphere Interaction
Authors: Lawrence David M. , Thornton Peter E. , Oleson Keith W. , Bonan Gordon B.
Published: September 2007

Although the global partitioning of evapotranspiration (ET) into transpiration, soil evaporation, and canopy evaporation is not well known, most current land surface schemes and the few available observations indicate that transpiration is the dominant component on the global scale, followed by soil evaporation and canopy evaporation. The Community Land Model version 3 (CLM3), however, does not reflect this global view of ET partitioning, with soil evaporation and canopy evaporation far outweighing transpiration. One consequence of this unrealistic ET partitioning in CLM3 is that photosynthesis, which is linked to transpiration through stomatal conductance, is significantly underestimated on a global basis. A number of modifications to CLM3 vegetation and soil hydrology parameterizations are described that improve ET partitioning and reduce an apparent dry soil bias in CLM3. The modifications reduce canopy interception and evaporation, reduce soil moisture stress on transpiration, increase transpiration through a more realistic canopy integration scheme, reduce within-canopy soil evaporation, eliminate lateral drainage of soil water, increase infiltration of water into the soil, and increase the vertical redistribution of soil water. The partitioning of ET is improved, with notable increases seen in transpiration (13%–41% of global ET) and photosynthesis (65–148 Pg C yr−1). Soils are wetter and exhibit a far more distinct soil moisture annual cycle and greater interseasonal soil water storage, which permits plants to sustain transpiration through the dry season.

The broader influences of improved ET partitioning on land–atmosphere interaction are diverse. Stronger transpiration and reduced canopy evaporation yield an extended ET response to rain events and a shift in the precipitation distribution toward more frequent small- to medium-size rain events. Soil moisture memory time scales decrease particularly at deeper soil levels. Subsurface soil moisture exerts a slightly greater influence on precipitation. These results indicate that partitioning of ET is an important responsibility for land surface schemes, a responsibility that will gain in relevance as GCMs evolve to incorporate ever more complex treatments of the earth’s carbon and hydrologic cycles.
An Improved Gridded Historical Daily Precipitation Analysis for Brazil
Authors: Silva Viviane B. S. , Kousky Vernon E. , Shi Wei , Higgins R. Wayne
Published: September 2007

A gauge-only precipitation data quality control and analysis system has been developed for monitoring precipitation at NOAA’s Climate Prediction Center (CPC). Over the past 10 yr the system has been used to develop and deliver many different precipitation products over the United States, Mexico, and Central and South America. Here the authors describe how the system has been applied to develop improved gridded daily precipitation analyses over Brazil. Consistent with previous studies, comparisons between the the gridded analyses and station observations reveal fewer dry days, a greater number of low precipitation days, and fewer extreme precipitation events in the gridded analyses. Even though the gridded analysis system reduces the number of dry days and increases the number of wet days, there is still a good correlation between time series of the gridpoint precipitation values and observations.

Retrospective analyses are important for computing basic statistics such as mean daily/monthly rainfall, extremes, and probabilities of wet and dry days. The CPC gridded precipitation analyses can be used in hydrologic and climate variability studies dealing with large spatial-scale anomaly patterns, such as those related to ENSO. The analyses can also be used as a benchmark for evaluating model simulations, serve as a basis for real-time monitoring, and provide statistics on the occurrence of large-scale heavy rainfall events and dry periods.
Modeling and Analysis of the Variability of the Water Cycle in the Upper Rio Grande Basin at High Resolution
Authors: Li J. , Gao X. , Sorooshian S.
Published: September 2007

Estimating the water budgets in a small-scale basin is a challenge, especially in the mountainous western United States, where the terrain is complex and observational data in the mountain areas are sparse. This manuscript reports on research that downscaled 5-yr (1999–2004) hydrometeorological fields over the upper Rio Grande basin from a 2.5° NCEP–NCAR reanalysis to a 4-km local scale using a regional climate model [fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5), version 3]. The model can reproduce the terrain-related precipitation distribution—the trend of diurnal, seasonal, and interannual precipitation variability—although poor snow simulation caused it to overestimate precipitation and evapotranspiration in the cold season. The outcomes from the coupled model are also comparable to offline Variable Infiltration Capacity (VIC) and Land Data Assimilation System (LDAS)/Mosaic land surface simulations that are driven by observed and/or analyzed surface meteorological data.
The Influence of Mechanical and Thermal Forcing by the Tibetan Plateau on Asian Climate
Authors: Wu Guoxiong , Liu Yimin , Zhang Qiong , Duan Anmin , Wang Tongmei , Wan Rijin , Liu Xin , Li Weiping , Wang Zaizhi , Liang Xiaoyun
Published: September 2007

This paper attempts to provide some new understanding of the mechanical as well as thermal effects of the Tibetan Plateau (TP) on the circulation and climate in Asia through diagnosis and numerical experiments. The air column over the TP descends in winter and ascends in summer and regulates the surface Asian monsoon flow. Sensible heating on the sloping lateral surfaces appears from the authors’ experiments to be the major driving source. The retarding and deflecting effects of the TP in winter generate an asymmetric dipole zonal-deviation circulation, with a large anticyclone gyre to the north and a cyclonic gyre to the south. Such a dipole deviation circulation enhances the cold outbreaks from the north over East Asia, results in a dry climate in south Asia and a moist climate over the Indochina peninsula and south China, and forms the persistent rainfall in early spring (PRES) in south China. In summer the TP heating generates a cyclonic spiral zonal-deviation circulation in the lower troposphere, which converges toward and rises over the TP. It is shown that because the TP is located east of the Eurasian continent, in summertime the meridional winds and vertical motions forced by the Eurasian continental-scale heating and the TP local heating are in phase over the eastern and central parts of the continent. The monsoon in East Asia and the dry climate in middle Asia are therefore intensified.
Influence of Precipitation Assimilation on a Regional Climate Model’s Surface Water and Energy Budgets
Authors: Nunes Ana M. B. , Roads John O.
Published: September 2007

Initialization of the moisture profiles has been used to overcome the imbalance between analysis schemes and prediction models that generates the so-called spinup problem seen in the hydrological fields. Here precipitation assimilation through moisture adjustment has been proposed as a technique to reduce this problem in regional climate simulations by adjusting the specific humidity according to 3-hourly North American Regional Reanalysis rain rates during two simulated years: 1988 and 1993. A control regional simulation provided the initial condition fields for both simulations. The precipitation assimilation simulation was then compared to the control regional climate simulation, reanalyses, and observations to determine whether assimilation of precipitation had a positive influence on modeled surface water and energy budget terms. In general, rainfall assimilation improved the regional model surface water and energy budget terms over the conterminous United States. Precipitation and runoff correlated better than the control and the global reanalysis fields to the regional reanalysis and available observations. Upward shortwave and downward short- and longwave radiation fluxes had regional seasonal cycles closer to the observed values than the control, and the near-surface temperature anomalies were also improved.
How to Meta-Analyze Coefficient-of-Stability Estimates
Authors: Mason Corinne , Allam Reynald , Brannick Michael T.
Published: September 2007

Reliability generalization studies have provided estimates of the mean reliability coefficients and examined factors that explain the variability in the reliability estimates across studies for many different tests and measures. Different authors have used different data analyses to do such meta-analyses, and little research has addressed whether some methods are more accurate than others. Three methods of meta-analysis for reliability data were compared using Monte Carlo techniques. The meta-analytic methods were those described by Hedges and Vevea, Hunter and Schmidt, and Vacha-Haase. The results suggested that a combination of methods worked best and that Hunter and Schmidt's method should be used to estimate the mean and random-effect variance component, but weighted regression should be used to model continuous moderators.
African Americans Versus the Memphis Street Railway Company
Authors: Goings Kenneth W. , Page Brian D.
Published: September 2007

The traditional interpretation of the southern justice system is that African Americans rarely, if ever, won. This article examines a seemingly anomalous situation in Memphis in which at the turn of the twentieth century, African Americans successfully sued the Memphis Street Railway Company for personal injury and racial insult. African American working-class men and women were often financially compensated for physical injuries, while African American middle-class women won their lawsuits against white conductors who insulted their personal dignity. These lawsuits amounted to personal victories for the plaintiffs but were in actuality political losses for African Americans in general. Through a detailed examination of race, class, and gender, the authors show how notions of middle-class respectability were contested by blacks and whites to influence the verdict in these lawsuits while simultaneously reinforcing negative stereotypes of African Americans that relegated the race to second-class citizens.
HRM Effectiveness in Older People's and Nursing Homes: The Search for Best (Quality) Practices
Authors: De Prins Peggy , Henderickx Erik
Published: September 2007

This article presents an empirical evaluation of the human resources management (HRM) effectiveness in relation to quality of labor and quality of care in older people's and nursing homes. The authors suggest that innovative policies, in terms of HRM and work design, increase the likelihood of lower stress rates and higher scores on quality of care. The data supply little empirical evidence for this hypothesis, which means that innovative policy practices have very little effect on the realities of stress, burnout, and individually tailored care. A question that arises from this is whether the search for best practices is then equal to a measure for nothing. This is not the authors' opinion. The reference framework for research must be turned round. This can be achieved by no longer starting from the normative (practice) theory but starting instead with excellent practice, which can teach researchers important content and policy lessons.