bluuebunny/crossref_metadata_2025 huggingface dataset:
Screening for obstructive sleep apnea in treacher‐collins syndrome
Authors: Plomp Raul G. , Joosten Koen F. M. , Wolvius Eppo B. , Hoeve Hans L. J. , Poublon Rene M. L. , van Montfort Kees A. G. M. , Bredero‐Boelhouwer Hansje H. , Mathijssen Irene M. J.
Published: February 2012

Objectives/Hypothesis:

This study evaluated the accuracy of established obstructive sleep apnea syndrome (OSAS) questionnaires based on presenting symptoms and complaints as screening tools for OSAS in Treacher‐Collins syndrome (TCS).

Study Design:

Cross‐sectional cohort study.

Methods:

In 35 TCS patients (13 children, 22 adults) in whom diagnostic polysomnographic results on OSAS were available, the Brouillette score was evaluated in children and the Epworth Sleepiness Scale in adults.

Results:

The total Brouillette score showed a sensitivity of 50%, specificity of 71%, and positive and negative predictive values of 60% and 63%, respectively. The answer “No” to the question as to whether a child snored could rule out OSAS in children, and showed positive and negative predictive values of 55% and 100%, respectively. The Epworth Sleepiness Scale showed a sensitivity of 0%, specificity of 92%, and positive and negative predictive values of 0% and 57%, respectively. A positive answer to the question of whether a person falls asleep while sitting and talking to someone (sometimes or more) was able to predict OSAS in adults; this question had positive and negative predictive values of 100% and 72%, respectively.

Conclusions:

This cross‐sectional cohort study showed that the Brouillette score and the Epworth Sleepiness Scale are of minimal usefulness in TCS. Diagnosis of OSAS based solely on complaints is not reliable, probably due to habituation. Therefore, for a good evaluation and optimal multidisciplinary treatment of this chronic disease in TCS, all newly referred pediatric and adult TCS patients should be screened for OSAS at least once with polysomnography. Laryngoscope, 2012
Late complications of nickel–titanium alloy stent in tracheal stenosis
Authors: Chen Wenxian , Ruan Yanyan
Published: February 2012

Objectives/Hypothesis:

To investigate and treat the late complications of using nickel–titanium alloy stents in laryngotracheal, bronchial, and esophageal stenosis patients who developed severe laryngotracheal stenosis (SLS).

Study Design:

Retrospective clinical study.

Methods:

Thirteen patients with SLS or tracheoesophageal fistula secondary to insertion of a nickel–titanium alloy stent for treatment of laryngotracheal, bronchial, or esophageal stenosis treated between May 2004 and March 2010 were retrospectively analyzed. Of the 13 total patients, nine had one stent placed, and four had two stents placed. The late complications observed were glottic and/or subglottic extension of cervical tracheal stenosis (n = 6), new stricture of the thoracic trachea (n = 4), severe left bronchial stricture with massive left pulmonary collapse (n = 1), and cervical tracheoesophageal fistula (n = 2).

Results:

Six patients with glottic and/or subglottic to cervical tracheal stenosis underwent successful laryngotracheal reconstruction. Two patients with subglottic and upper thoracic tracheal stenosis were successfully treated by staged operation for the stenosis. Two patients with subglottic and distal thoracic tracheal stenosis are still undergoing treatment. One patient with severe left bronchial stricture and massive left pulmonary collapse has been treated but has not achieved full recovery. One patient with cervical tracheoesophageal fistula underwent successful repair but died later from metastatic disease. One patient with tracheoesophageal fistula died from massive hemorrhage and asphyxiation induced by the stent, which had not been removed.

Conclusions:

The nickel–titanium alloy stents should be used with extreme caution in patients with laryngotracheal, bronchial, or esophageal stenosis treatment that can be corrected by surgical therapy. Laryngoscope, 2012
Tympanic membrane retraction: An endoscopic evaluation of staging systems
Authors: James Adrian L. , Papsin Blake C. , Trimble Keith , Ramsden James , Sanjeevan Nadarajah , Bailie Neil , Chadha Neil K.
Published: February 2012

Objectives/Hypothesis:

The objectives of this work were to assess inter‐ and intraobserver variability of different staging systems for tympanic membrane (TM) retraction using otoendoscopy in children at risk of retraction from cleft palate, to compare hearing level with stage of retraction, and to propose optimum characteristics for monitoring TM retraction with endoscopy.

Study Design:

Cross‐sectional study.

Methods:

Endoscopic images of 245 TMs of children with cleft palate (mean age, 13.0 years) were assessed on two separate occasions by six observers using the Sade and Erasmus staging systems for pars tensa retraction and Tos system for pars flaccida retraction. Intra‐ and interobserver agreements were calculated. Extent of TM retraction was compared with hearing threshold. TMs with middle ear effusion, tympanostomy tubes, or perforation were excluded.

Results:

A total of 108 ear drums (44%) were rated as having pars tensa and/or flaccida retraction. Intraobserver agreement was fair to moderate (kappa = 0.3–0.37, P < .001) for the different staging systems and interobserver agreement slight to moderate (0.18–0.41 P < .001). Conductive hearing loss (four‐tone average air‐bone gap >25 dB HL) was present in 11 ears (15%). No correlation between hearing threshold and retraction stage was found. Isolated tensa retraction onto the promontory increased hearing threshold more than retraction involving the incus (P = .02; analysis of variance).

Conclusions:

Endoscopic image capture may provide a clear objective record of TM retraction, but current staging systems have unsatisfactory reliability when applied to such images, and retraction stage correlates poorly with hearing threshold. Modification of retraction assessment to improve validity and clinical relevance is proposed.
Validating the clinical assessment of eustachian tube dysfunction: The eustachian tube dysfunction questionnaire (ETDQ‐7)
Authors: McCoul Edward D. , Anand Vijay K. , Christos Paul J.
Published: February 2012

Objectives/Hypothesis:

Eustachian tube dysfunction (ETD) is a common condition that is associated with otologic and rhinologic symptoms. The complete assessment of ETD is limited without a valid symptom score. We developed and conducted initial validation of the seven‐item Eustachian Tube Dysfunction Questionnaire (ETDQ‐7), a disease‐specific instrument to assess symptoms with respect to ETD.

Study Design:

Validation study.

Methods:

The ETDQ‐7 was developed using standard survey methodology. The ETDQ‐7 was completed by a group of 50 consecutive adult patients diagnosed with ETD and 25 non‐ETD patients who served as a control group. Tympanometry was used as a criterion standard to distinguish the two groups. A subset of respondents repeated the ETDQ‐7 at a time point 4 weeks later.

Results:

Content validity for the ETDQ‐7 was established by focus group and review of the literature. Reliability testing indicated acceptable internal consistency for the entire instrument (Cronbach α = .71). The test–retest reliability indicated good correlation between the two questionnaires completed by the same patient 4 weeks apart (r = 0.78). The ETDQ‐7 was able to discriminate between patients with ETD and those without (P < .001), indicating excellent discriminant validity.

Conclusions:

The ETDQ‐7 is a valid and reliable symptom score for use in adult patients with ETD that may facilitate clinical practice by highlighting the impact of ETD. Further testing is needed to determine its usefulness in assessing treatment response.
Investigation of the role of the cerebellum in the myoclonic‐like movement disorder exhibited by tottering mice
Authors: Abbott Louise C. , Bump Melissa , Brandl Amy , De Laune Scarlett
Published: February 2012

Recently it has been discovered that defects in neuronal ion channels can result in seizure disorders. The tottering mouse is a genetic animal model carrying a mutation in the α1A calcium channel subunit that causes these mice to exhibit generalized petit mal‐like epilepsy, cerebellar ataxia, and an intermittent movement disorder that has some characteristics similar to myoclonus or myoclonic epilepsy. We postulate that abnormal cerebellar Purkinje cell output to the deep cerebellar nuclei results in the intermittent movement disorder observed in these mice. The frequency and duration of seizure activity were measured in tottering mice before and 2 weeks after surgical or chemical lesioning of the cerebellum. Surgical lesions in the anterior cerebellar vermis of tottering mice produced significant reductions in seizure duration and frequency. Surgical lesioning of the posterior cerebellar vermis had no significant effect. Chemical lesions of the same cerebellar regions, using a locally applied neurotoxin, NMD‐L‐A, appear to produce effects similar to the surgical lesions. These data indicate that anterior vermal cerebellar output is important for production of the seizures associated with the intermittent movement disorder observed in tottering mice.
Charcot‐marie‐tooth disease presenting as a nonhealing ulcer in a 26‐year‐old man
Authors: Judhan Rudy J. , Maharaj Stefan R. , Perry Andrew , Dellon A. Lee , Maharaj Dale
Published: February 2012

A 26‐year‐old man presented with a nonhealing ulcer on the plantar aspect of the left foot of five years duration. Initial investigations were unremarkable. It was only after careful neurological examination that an inherited neuropathy was suspected. This was confirmed by nerve conduction studies and serum electrophoresis. He subsequently underwent partial great toe amputation for the ulcer and underlying first phalangeal osteomyelitis with uneventful healing. Neuropathic ulcers are usually associated with several well‐known disorders including diabetes mellitus, tabes dorsalis, pernicious anemia, and sickle cell disease. A rarer cause is Charcot‐Marie‐Tooth Disease (CMTD). The report gives a review of CMTD and emphasizes that when faced with a nonhealing ulcer in the younger age group, such an underlying hereditary neuropathic cause must be considered. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Bilateral autologous breast reconstruction with deep inferior epigastric artery perforator flaps: Review of a single surgeon's early experience
Authors: Venkat Raghunandan , Lee Johnson C. , Rad Ariel N. , Manahan Michele A. , Rosson Gedge D.
Published: February 2012

Background:

The purpose of this study is to describe the early experience of a single surgeon just out of training, including preoperative conditioning, surgical approach, and outcomes in bilateral deep inferior epigastric artery perforator (DIEP) flap breast reconstruction patients.

Methods:

We retrospectively reviewed 54 consecutive patients who underwent 108 DIEP flap breast reconstructions performed by a single surgeon over an initial 2.5‐year period.

Results:

There was 100% overall flap survival. The unplanned reoperation rate was 7.6% (n = 4). Minor complications including nonoperative infection, minor wound dehiscence, and donor site seroma occurred in 26% of patients (n = 14). Significant late complications were abdominal wall bulge (n = 1) and fat necrosis < 10% of volume (n = 1). Tissue expander explantation due to infection occurred in 25% of attempted staged patients (two of eight); this did not seem to compromise their oncologic treatment or final reconstruction outcome.

Conclusion:

This study demonstrates the efficacy of the DIEP flap for bilateral autologous breast reconstruction in the immediate, staged, and delayed settings. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Correlation imaging for multiscan MRI with parallel data acquisition
Authors: Li Yu , Dumoulin Charles
Published: February 2012

A new approach to high‐speed magnetic resonance imaging (MRI) that uses all the data acquired in a multiscan imaging session is presented. This approach accelerates MRI data acquisition by statistically estimating correlation functions from images with different contrast and/or resolution. In multiscan MRI with parallel data acquisition, the estimation of correlation functions is dynamically improved as imaging proceeds. This allows imaging acceleration factors to be increased in subsequent scans, thereby reducing the total time of a multiscan MRI protocol. Furthermore, the correlation function estimates bring information about both coil sensitivity and anatomical structure into image reconstruction, thereby offering the ability to speed up MRI beyond the parallel imaging acceleration limit posed by a coil array alone. In this study, the feasibility of correlation imaging is demonstrated experimentally using brain and spine imaging protocols. The ability of correlation imaging to achieve an aggregate acceleration factor in excess of the number of coil elements in the phase encoding direction is also demonstrated. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Loss of bladder smooth muscle caveolae in the aging bladder
Authors: Lowalekar Samar K. , Cristofaro Vivian , Radisavljevic Ziv M. , Yalla Subbarao V. , Sullivan Maryrose P.
Published: February 2012

Aims

Caveolae are specialized regions of the cell membrane that modulate signal transduction and alterations in these structures affect bladder smooth muscle (BSM) contraction. Since bladder dysfunctions are common in the elderly, we evaluated the effect of aging on the morphology of caveolae and caveolin protein expression in BSM.

Methods

Caveolar morphology (number, size, and depth) in BSM was determined from electron microscopy images of young (10 weeks), adult (6‐month old), and old (12‐month old) rat urinary bladders. Changes in expression levels of caveolin proteins with age were investigated by Western blot and immunofluorescence microscopy. Caveolin‐3 gene expression was determined by real‐time RT‐PCR in young and 19‐month‐old rat bladders.

Results

Twelve‐month‐old animals exhibited 50% fewer BSM caveolae compared to young (P < 0.01). The area of caveolae was significantly decreased at 6 and 12 months. Despite a decrease in the number of BSM caveolae at 12 months, the expression of caveolin‐1 and cavin‐1 were unaltered with age. In contrast, caveolin‐2 and caveolin‐3 protein expression and immunoreactivity were reduced in BSM at 6 and 12 months of age. Caveolin‐3 gene expression was also downregulated at 19 months compared to young animals.

Conclusion

Biological aging significantly decreases BSM caveolae number and morphology with associated selective alteration in caveolin protein expression. Since caveolae are protected membrane regions that regulate signal transduction, age‐related alterations in caveolae and caveolin protein expression could alter BSM contractility resulting in bladder dysfunctions of the elderly. Neurourol. Urodynam. 31:586–592, 2012. © 2012 Wiley Periodicals, Inc.
Finding off‐diagonal entries of the inverse of a large symmetric sparse matrix
Authors: Eastwood Shawn , Wan Justin W. L.
Published: February 2012

The method fast inverse using nested dissection (FIND) was proposed to calculate the diagonal entries of the inverse of a large sparse symmetric matrix. In this paper, we show how the FIND algorithm can be generalized to calculate off‐diagonal entries of the inverse that correspond to ‘short’ geometric distances within the computational mesh of the original matrix. The idea is to extend the downward pass in FIND that eliminates all nodes outside of each node cluster. In our advanced downwards pass, it eliminates all nodes outside of each ‘node cluster pair’ from a subset of all node cluster pairs. The complexity depends on how far (i,j) is from the main diagonal. In the extension of the algorithm, all entries of the inverse that correspond to vertex pairs that are geometrically closer than a predefined length limit l will be calculated. More precisely, let α be the total number of nodes in a two‐dimensional square mesh. We will show that our algorithm can compute O(α3 ∕ 2 + 2ε) entries of the inverse in O(α3 ∕ 2 + 2ε) time where l = O(α1 ∕ 4 + ε) and 0 ≤ ε ≤1 ∕ 4. Numerical examples are given to illustrate the efficiency of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.
Response to Comment on ‘Preconditioning of matrices partitioned in 2 × 2 block form: Eigenvalue estimates and Schwarz DD for mixed FEM’
Authors: Axelsson Owe , Blaheta Radim
Published: February 2012

As has been pointed out in a study by Cao, there is an erroneous omission in the study by Axelsson, Corollary 3.2 and Proposition 3.2, and the authors thank Zhi‐hao Cao for pointing this out.

We mention, however, that these are side results and do not influence the major result of the paper ‘Preconditioning of matrices partitioned in 2 by 2 block form: Eigenvalue estimates and Schwarz DD for mixed FEM’.

In this reply, we give a short background to the relations between inverses of saddle point matrices, thereby providing justified references to previous publications of the topic and present a corrected and extended version of Proposition 3.2. This gives an alternative presentation of the statements in the study by Cao, which might be useful for readers. Copyright © 2012 John Wiley & Sons, Ltd.
Guaranteed computable bounds on quantities of interest in finite element computations
Authors: Ainsworth Mark , Rankin Richard
Published: February 2012

We develop and compare a number of alternative approaches to obtain guaranteed and fully computable bounds on the error in quantities of interest of arbitrary order finite element approximations in the context of a linear second‐order elliptic problem. In each case, the bounds are fully computable and do not involve any unknown multiplicative factors. Guaranteed computable bounds are also obtained for the case when the Dirichlet boundary conditions are non‐homogeneous. This is achieved by taking account of the error incurred by the approximation of the Dirichlet data in the functional used to approximate the quantity of interest itself, which is found to generally give better results. Numerical examples are presented to show that the resulting estimators provide tight bounds with the effectivity index tending to unity from above. Copyright © 2012 John Wiley & Sons, Ltd.
Mediators of receptor tyrosine kinase activation in infantile fibrosarcoma: a Children's Oncology Group study
Authors: Gadd Samantha , Beezhold Patricia , Jennings Lawrence , George David , Leuer Katrin , Huang Chiang‐Ching , Huff Vicki , Tognon Cristina , Sorensen Poul HB , Triche Timothy , Coffin Cheryl M , Perlman Elizabeth J
Published: February 2012

Infantile fibrosarcoma (IFS; also known as cellular congenital mesoblastic nephroma, CMN, when in the kidney) is a rare, undifferentiated tumour often characterized by the ETV6‐NTRK3 fusion transcript. Our goal was to identify downstream pathways, diagnostic markers and potential therapeutic targets for IFS/CMN. Global gene expression, reverse‐phase protein array and ETV6‐NTRK3 fusion analyses were performed on 14 IFS/CMN and compared with 41 other paediatric renal tumours. These analyses confirm significant receptor tyrosine kinase (RTK) activation, with evidence of PI3‐Akt, MAPK and SRC activation. In particular, GAB2 docking protein, STAT5‐pTyr‐694, STAT3‐pSer‐729 and YAP‐pSer‐127 were elevated, and TAZ‐pSer‐89 was decreased. This provides mRNA and proteomic evidence that GAB2, STAT activation and phosphorylation of the Hippo pathway transcription co‐activators YAP and TAZ contribute to the RTK signal transduction in IFS/CMN. All IFS/CMN tumours displayed a distinctive gene expression pattern that may be diagnostically useful. Unexpectedly, abundant ETV6‐NTRK3 transcript copies were present in only 7/14 IFS, with very low copy number in 3/14. An additional 4/14 were negative by RT‐PCR and absence of ETV6‐NTRK3 was confirmed by FISH for both ETV6 and NTRK3. Therefore, molecular mechanisms other than ETV6‐NTRK3 fusion are responsible for the development of some IFS/CMNs and the absence of ETV6‐NTRK3 fusion products should not exclude IFS/CMN as a diagnosis. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Frequent activating GNAS mutations in villous adenoma of the colorectum
Authors: Yamada Masayoshi , Sekine Shigeki , Ogawa Reiko , Taniguchi Hirokazu , Kushima Ryoji , Tsuda Hitoshi , Kanai Yae
Published: February 2012

To elucidate the role of GNAS mutations in colorectal tumourigenesis, we performed a mutation analysis in a total of 234 colorectal tumours, including adenomas, serrated lesions and adenocarcinomas. Activating GNAS mutations were found in 20 of the 24 villous adenomas (83%) but were absent in all the other tumours, except for one tubulovillous adenoma (3%) and two adenocarcinomas (3%). KRAS and BRAF mutations were always mutually exclusive. KRAS mutations were frequent in villous (67%) and tubulovillous (60%) adenomas but were rare or absent in tubular adenomas (6%) and serrated lesions, including hyperplastic polyps, sessile serrated polyps/sessile serrated lesions and traditional serrated adenomas (0‐9%). BRAF mutations were found in four villous adenomas (17%) and in the large majority of serrated lesions (81‐92%), but were absent in tubular and tubulovillous adenomas. Seventeen villous adenomas (71%) harboured GNAS mutations concomitantly with KRAS or BRAF mutations. Immunohistochemically, all the villous adenomas retained mismatch repair protein expression, suggesting that they are microsatellite‐stable. The current study showed that the presence of activating GNAS mutations, in association with KRAS or BRAF mutations, is a characteristic genetic feature of colorectal villous adenoma. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Neutrophil‐mediated experimental metastasis is enhanced by VEGFR inhibition in a zebrafish xenograft model
Authors: He Shuning , Lamers Gerda EM , Beenakker Jan‐Willem M , Cui Chao , Ghotra Veerander PS , Danen Erik HJ , Meijer Annemarie H , Spaink Herman P , Snaar‐Jagalska B Ewa
Published: February 2012

Inhibition of VEGF signalling effectively suppresses localized tumour growth but accelerates tumour invasiveness and micrometastasis by unknown mechanisms. To study the dynamic and reciprocal interactions between tumour cells and their microenvironment during these processes, we established a xenograft model by injecting tumour cells into the blood circulation of transparent zebrafish embryos. This reproducibly results in rapid simultaneous formation of a localized tumour and experimental micrometastasis, allowing time‐resolved imaging of both processes at single‐cell resolution within 1 week. The tumour vasculature was initiated de novo by remodelling of primitive endothelial cells into a functional network. Roles of myeloid cells in critical tumourigenesis steps such as vascularization and invasion were revealed by genetic and pharmaceutical approaches. We discovered that the physiological migration of neutrophils controlled tumour invasion by conditioning the collagen matrix and forming the metastatic niche, as detected by two‐photon confocal microscopy and second harmonic generation. Administration of VEGFR inhibitors blocked tumour vascularization and a localized tumour growth but enhanced migration of neutrophils, which in turn promoted tumour invasion and formation of micrometastasis. This demonstrates the in vivo cooperation between VEGF signalling and myeloid cells in metastasis and provides a new mechanism underlying the recent findings that VEGFR targeting can promote tumour invasiveness. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The dark side of a success story: microRNAs of the C19MC cluster in human tumours
Authors: Flor Inga , Bullerdiek Jörn
Published: February 2012

MicroRNAs are a class of macromolecules of rapidly emerging significance for the pathogenesis of numerous human diseases, including cancer. Moreover, many of them hold great promise as valid biomarkers because of their high extracellular stability. Chromosome 19 harbours the largest cluster of microRNA genes known so far, which has developed in a very short time during mammalian evolution. Thus, in terms of evolution, gain of this cluster is an apparent success story. Nevertheless, we know very little about how functions of its microRNAs have contributed to this success and apparently, at least some of them can turn from Jekyll into Hyde and contribute to tumourigenesis. Recent work published in the Journal of Pathology by Fornari and colleagues, addressed here, reveals how members of that cluster are involved in the molecular pathogenesis of hepatocellular carcinomas. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Activation of protein kinase Cδ leads to increased pancreatic acinar cell dedifferentiation in the absence of MIST1
Authors: Johnson Charis L , Peat Jodi M , Volante Sonia N , Wang Rennian , McLean Carolyn A , Pin Christopher L
Published: February 2012

Pancreatic ductal adenocarcinoma (PDAC) has a 5 year survival rate post‐diagnosis of < 5%. Individuals with chronic pancreatitis (CP) are 20‐fold more likely to develop PDAC, making it a significant risk factor for PDAC. While the relationship for the increased susceptibility to PDAC is unknown, loss of the acinar cell phenotype is common to both pathologies. Pancreatic acinar cells can dedifferentiate or trans‐differentiate into a number of cell types including duct cells, β cells, hepatocytes and adipocytes. Knowledge of the molecular pathways that regulate this plasticity should provide insight into PDAC and CP. MIST1 (encoded by Bhlha15 in mice) is a transcription factor required for complete acinar cell maturation. The goal of this study was to examine the plasticity of acinar cells that do not express MIST1 (Mist1−/−). The fate of acinar cells from C57Bl6 or congenic Mist1−/− mice expressing an acinar specific, tamoxifen‐inducible Cre recombinase mated to Rosa26 reporter LacZ mice (Mist1CreERT/− R26r) was determined following culture in a three‐dimensional collagen matrix. Mist1CreERT/− R26r acini showed increased acinar dedifferentiation, formation of ductal cysts and transient increases in PDX1 expression compared to wild‐type acinar cells. Other progenitor cell markers, including Foxa1, Sox9, Sca1 and Hes1, were elevated only in Mist1−/− cultures. Analysis of protein kinase C (PKC) isoforms by western blot and immunofluorescence identified increased PKCε accumulation and nuclear localization of PKCδ that correlated with increased duct formation. Treatment with rottlerin, a PKCδ‐specific inhibitor, but not the PKCε‐specific antagonist εV1‐2, reduced acinar dedifferentiation, progenitor gene expression and ductal cyst formation. Immunocytochemistry on CP or PDAC tissue samples showed reduced MIST1 expression combined with increased nuclear PKCδ accumulation. These results suggest that the loss of MIST1 is a common event during PDAC and CP and events that affect MIST1 function and expression may increase susceptibility to these pathologies. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Integrating multi‐tiered measurement outcomes for special education eligibility with sequential decision‐making methodology
Authors: Decker Scott L. , Englund Julia , Albritton Kizzy
Published: February 2012

Changes to federal guidelines for the identification of children with disabilities have supported the use of multi‐tiered models of service delivery. This study investigated the impact of measurement methodology as used across numerous tiers in determining special education eligibility. Four studies were completed using a sample of inner‐city children (N = 150) who were administered a reading screener twice and a reading measure adapted from the state high‐stakes reading test. A sub‐sample of children identified as At‐Risk were administered a comprehensive reading assessment and compared with a randomly selected control group, who were also administered a comprehensive reading assessment (n = 14). A model was developed to estimate the likelihood of special education eligibility based on both theoretical and empirical measurement parameters. Depending on the measurement assumptions of the multi‐tiered model, special education eligibility outcomes varied from a low of 0.2% to as high as 11%, depending on the type of measure used, decision‐making criteria used at each tier, and the number of tiers in the model. This study highlights the importance of measurement specification, explicit decision‐making criteria, and empirical investigation to fully understand outcomes associated with the implementation of multi‐tiered models. Implications for special education eligibility policy and practical implications for implementing comprehensive measurement practice in multi‐tiered systems at the school level are discussed. © 2012 Wiley Periodicals, Inc.
A Comparative Study of the Benefits of Applying Target Cost Contracts between South Australia and Hong Kong
Authors: Chan Daniel W. M. , Lam Patrick T. I. , Chan Joseph H. L , Ma Tony , Perkin Thomas
Published: February 2012

This article aims to identify and analyze the key benefits of adopting Guaranteed Maximum Price and Target Cost Contracts (GMP/TCC) over and above the traditional lump-sum contractual arrangement through an empirical questionnaire survey conducted in South Australia and compared with the findings in Hong Kong. The Mann-Whitney U Test indicated differences in perception between the two groups of respondents on the majority of the identified benefits. The study has provided an in-depth understanding of the perceived benefits of the GMP/TCC scheme, hence leading to a wider application of those alternative integrated procurement strategies in both regions for reference by the construction community at large.
Acyl carrier protein structural classification and normal mode analysis
Authors: Cantu David C. , Forrester Michael J. , Charov Katherine , Reilly Peter J.
Published: February 2012

All acyl carrier protein primary and tertiary structures were gathered into the ThYme database. They are classified into 16 families by amino acid sequence similarity, with members of the different families having sequences with statistically highly significant differences. These classifications are supported by tertiary structure superposition analysis. Tertiary structures from a number of families are very similar, suggesting that these families may come from a single distant ancestor. Normal vibrational mode analysis was conducted on experimentally determined freestanding structures, showing greater fluctuations at chain termini and loops than in most helices. Their modes overlap more so within families than between different families. The tertiary structures of three acyl carrier protein families that lacked any known structures were predicted as well.
Is there an en route folding intermediate for cold shock proteins?
Authors: Huang Lei , Shakhnovich Eugene I.
Published: February 2012

Cold shock proteins (Csps) play an important role in cold shock response of a diverse number of organisms ranging from bacteria to humans. Numerous studies of the Csp from various species showed that a two‐state folding mechanism is conserved and the transition state (TS) appears to be very compact. However, the atomic details of the folding mechanism of Csp remain unclear. This study presents the folding mechanism of Csp in atomic detail using an all‐atom Go model‐based simulations. Our simulations predict that there may exist an en route intermediate, in which β strands 1‐2‐3 are well ordered and the contacts between β1 and β4 are almost developed. Such an intermediate might be too unstable to be detected in the previous fluorescence energy transfer experiments. The transition state ensemble has been determined from the Pfold analysis and the TS appears even more compact than the intermediate state.
A Bayesian approach to the statistical analysis of device preference studies
Authors: Fu Haoda , Qu Yongming , Zhu Baojin , Huster William
Published: February 2012

Drug delivery devices are required to have excellent technical specifications to deliver drugs accurately, and in addition, the devices should provide a satisfactory experience to patients because this can have a direct effect on drug compliance. To compare patients' experience with two devices, cross‐over studies with patient‐reported outcomes (PRO) as response variables are often used. Because of the strength of cross‐over designs, each subject can directly compare the two devices by using the PRO variables, and variables indicating preference (preferring A, preferring B, or no preference) can be easily derived. Traditionally, methods based on frequentist statistics can be used to analyze such preference data, but there are some limitations for the frequentist methods. Recently, Bayesian methods are considered an acceptable method by the US Food and Drug Administration to design and analyze device studies. In this paper, we propose a Bayesian statistical method to analyze the data from preference trials. We demonstrate that the new Bayesian estimator enjoys some optimal properties versus the frequentist estimator. Copyright © 2012 John Wiley & Sons, Ltd.
Optimal control of katabatic flows within canopies
Authors: Chen Hongbin , Yi Chuixiang
Published: February 2012

What slope angle favours the development of katabatic flow is still an open question. Some studies have clarified that katabatic winds are stronger on steep slopes, while others have demonstrated that katabatic winds are stronger on gentle slopes. Here, we explore the control mechanisms of katabatic flow using a simplified theoretical model in an attempt to clarify the causes of the paradoxical findings. Our results indicate that optimal conditions for katabatic flows within canopies are synergistically controlled by terrain angle, canopy structure and thermal condition through a simple equation \documentclass{article}\usepackage{amsmath}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{amsfonts}\pagestyle{empty}\begin{document}$L_{{\mathrm c}} V_T^{-2} \sin^{3}\alpha = b$ \end{document}, where α is terrain slope, Lc = 1/(cDa) is canopy length‐scale, cD is drag coefficient, a is leaf area density, VT = Rc/γ is a thermal factor, Rc is a cooling rate, γ is ambient lapse rate, and b is a constant. This theoretical prediction implies that gentle slopes are optimal for katabatic flow developments in stably stratified air while steep slopes are optimal in weak or near‐neutral stratification. Canopy effect is significant in the control of katabatic flows only on gentle slopes. Copyright © 2012 Royal Meteorological Society
Dispersion analysis of the spectral element method
Authors: Melvin Thomas , Staniforth Andrew , Thuburn John
Published: February 2012

The spectral element method (SEM) has (with exact time integration) the desirable attribute of locally and globally conserving mass, energy and potential vorticity. It also scales well on massively parallel computers. Another desirable attribute of a numerical method for an atmospheric dynamical core is that it should have good numerical dispersion properties in order to accurately represent wave propagation and adjustment processes. Application of the SEM to the one‐way wave equation is analysed to provide insight into its dispersion properties as a function of spectral order. For the lowest‐order spectral truncation (linear) the SEM discretisation is formally equivalent to centred second‐order finite differences on an Arakawa A grid. It consequently shares its poor dispersion properties, including energy propagation in the wrong direction for the short‐wavelength half of the spectrum. Increasing the spectral truncation of the SEM to quadratic improves its dispersion properties for the long‐wavelength part of the spectrum, but the problem of energy propagation in the wrong direction for the short‐wavelength part remains. Further increasing the order of the spectral truncation not only fails to address the poor energy propagation at small scales, but also introduces new problems, including gaps in the spectrum of frequencies that can be represented, and localisation of eigenmode structures near element boundaries. Numerical integrations confirm that these SEM dispersion properties lead to reversed group velocities and to grid imprinting at spectral element boundaries. Copyright © 2012 Royal Meteorological Society and British Crown Copyright, the Met Office
On the Analysis of Balanced Two‐Level Factorial Whole‐Plot Saturated Split‐Plot Designs
Authors: Perry Marcus B. , Mercado Gary R. , Simpson James R.
Published: February 2012

This paper considers an experimentation strategy when resource constraints permit only a single design replicate per time interval and one or more design variables are hard to change. The experimental designs considered are two‐level full‐factorial or fractional‐factorial designs run as balanced split plots. These designs are common in practice and appropriate for fitting a main‐effects‐plus‐interactions model, while minimizing the number of times the whole‐plot treatment combination is changed. Depending on the postulated model, single replicates of these designs can result in the inability to estimate error at the whole‐plot level, suggesting that formal statistical hypothesis testing on the whole‐plot effects is not possible. We refer to these designs as balanced two‐level whole‐plot saturated split‐plot designs. In this paper, we show that, for these designs, it is appropriate to use ordinary least squares to analyze the subplot factor effects at the ‘intermittent’ stage of the experiments (i.e., after a single design replicate is run); however, formal inference on the whole‐plot effects may or may not be possible at this point. We exploit the sensitivity of ordinary least squares in detecting whole‐plot effects in a split‐plot design and propose a data‐based strategy for determining whether to run an additional replicate following the intermittent analysis or whether to simply reduce the model at the whole‐plot level to facilitate testing. The performance of the proposed strategy is assessed using Monte Carlo simulation. The method is then illustrated using wind tunnel test data obtained from a NASCAR Winston Cup Chevrolet Monte Carlo stock car. Copyright © 2012 John Wiley & Sons, Ltd.
Mini‐navigator: a new system for navigated deformity corrections
Authors: Liodakis Emmanouil , Macke Christian , Kenawey Mohamed , Krettek Christian
Published: February 2012

Background

The purpose of this study is to present a new navigation device for deformity correction surgery and to evaluate its accuracy compared with a conventional electromagnetic navigation system in tracking the orientation of synthetic bony fragments.

Methods

This system consists of three sensors and software which can be installed on any personal computer. One sensor is mounted about 1 m above the other sensors. The remaining two sensors are fixed to the bone fragments using Schanz screws. Data from all three sensors are computed using the software to estimate the change in position of the sensors. For the first part of the study 118 planned one and two plane deformities in 5° increments were created. For the second part of the study complex random 3‐dimensional deformities were created (300 valid measurements).

Results

The mean absolute differences between measurements of the electromagnetic and mini‐navigator were 1.8 ± 1.9° in the coronal, 1.1 ± 1.1° in the sagittal and 0.8 ± 0.7° in the transverse plane. Absolute differences between mini‐navigator and Fastrak measurements were significantly affected by the magnitude of the deformity (P < 0.0001) with better accuracy for lower deformities.

Conclusions

We believe that this new technology is appealing, because of its high accuracy and lower planned costs compared with conventional navigation devices. Copyright © 2012 John Wiley & Sons, Ltd.
da Vinci® single‐site platform: anthropometrical, docking and suturing considerations for hysterectomy in the cadaver model
Authors: Escobar Pedro F. , Knight Jason , Rao Sanjay , Weinberg Lori
Published: February 2012

Background

The paper describes specific technical requirements, limitations, anthropometrical, docking and suturing considerations on the performance of robotic hysterectomy using the da Vinci® Single‐Site Platform in the cadaver model

Methods

A data set was collected for each procedure including port placement, docking sequence, robotic arms placement and angles, robotic instrumentation, optimal ergonomics, operative time, and cadaver anthropometrical measurements. Pearson correlation coefficients were calculated to determine whether age, BMI or docking approach were correlated with docking difficulty and likelihood of successful procedure completion. Analysis of the data was performed using SPSS v19.0.0.

Results

The planned surgical procedure was successfully completed with single‐port robotics in 87.5% of cases. High BMI was correlated with difficulty docking the robot, correlation coefficient 0.98.

Conclusions

Further work is needed in the development and advancement of single‐site robotic platforms, articulated instrumentation, and optics. Copyright © 2012 John Wiley & Sons, Ltd.
Network intrusion detection using hybrid binary PSO and random forests algorithm
Authors: Malik Arif Jamal , Shahzad Waseem , Khan Farrukh Aslam
Published: February 2012

Network security risks grow with increase in the network size. In recent past, the attacks on computer networks have increased tremendously and require efficient network intrusion detection mechanisms. Data mining and machine‐learning techniques have been used for network intrusion detection during the past few years and have gained much popularity. In this paper, we propose an intrusion detection mechanism based on binary particle swarm optimization (PSO) and random forests (RF) algorithms called PSO‐RF and investigate the performance of various dimension reduction techniques along with a set of different classifiers including the proposed approach. Binary PSO is used to find more appropriate set of attributes for classifying network intrusions, and RF is used as a classifier. In the preprocessing step, we reduce the dimensions of the dataset by using different state‐of‐the‐art dimension reduction techniques, and then this reduced dataset is presented to the proposed PSO‐RF approach that further optimizes the dimensions of the data and finds an optimal set of features. PSO is an optimization method that has a strong global search capability and is used here for dimension optimization. We perform extensive experimentation to prove the worth of the proposed approach by using different performance metrics. The standard benchmark, that is, KDD99Cup dataset, is used that contains the information about various kinds of network intrusions. The experimental results indicate that the proposed approach performs better than the other approaches for the detection of all kinds of attacks present in the dataset. Copyright © 2012 John Wiley & Sons, Ltd.
Drosophila models of epithelial stem cells and their niches
Authors: Sahai‐Hernandez Pankaj , Castanieto Angela , Nystul Todd G.
Published: February 2012

Epithelial stem cells are regulated through a complex interplay of signals from diffusible ligands, cellular interactions, and attachment to the extracellular matrix. The development of Drosophila models of epithelial stem cells and their associated niche has made it possible to dissect the contribution of each of these factors in vivo, during both basal homeostasis and in response to acute damage such as infection. Studies of Drosophila epithelial stem cells have also provided insight into the mechanisms by which a healthy population of stem cells are maintained throughout adulthood by demonstrating, for example, that stem cells have a finite lifespan and may be displaced by replacement cells competing for niche occupancy. Here, we summarize the literature on each of the known Drosophila epithelial stem cells, with a focus on the two most well‐characterized types, the follicle stem cells (FSCs) in the ovary and the intestinal stem cells (ISCs) in the posterior midgut. Several themes have emerged from these studies, which suggest that there may be a common set of features among niches in a variety of epithelia. For example, unlike the simpler Drosophila germline stem cell niches, both the FSC and ISC niches produce multiple, partially redundant, niche signals, some of which activate pathways such as Wnt/Wingless, Hedgehog, and epidermal growth factor (EGF) that also regulate mammalian epithelial tissue renewal. Further study into these relatively new stem cell models will be of use in understanding both the specifics of epithelial regeneration and the diversity of mechanisms that regulate adult stem cells in general. WIREs Dev Biol 2012, 1:447–457. doi: 10.1002/wdev.36

This article is categorized under:

Early Embryonic Development > Gametogenesis

Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches
Cav3 T‐type calcium channels
Authors: Senatore Adriano , Zhorov Boris S. , Spafford J. David
Published: February 2012

T‐type channels are unique among the voltage‐gated calcium channels in their fast kinetics and low voltages of activation and inactivation, the latter two features allowing them to operate at voltages near the resting membrane potential of most neurons. T‐type channels can therefore be recruited by subthreshold depolarizations, and hyperpolarizations that remove inactivation. As such, T‐type channels can significantly influence how and when cells reach action potential threshold, and thus are critical regulators of excitability. T‐type channels are also significantly conserved within the animal kingdom, present even in animals lacking muscles and nerves, suggesting that they evolved before or very early on during the emergence of neuronal and neuromuscular synapses. Physiologically, T‐type channels are involved in multiple processes, and their contributions range from purely electrogenic roles to the activation of calcium‐sensitive ion channels, signaling pathways, and other macromolecular complexes. Unfortunately, it has been difficult to prove sufficiency and necessity of T‐type channels in many of these processes, in part due to inconsistencies in their suspected contributions. Furthermore, gene knockout studies have failed to show that T‐type channels are essential for development or survival, as knockout animals exhibit only weak phenotypes. T‐type channels roles are likely dependent on cellular context, and the three mammalian isotypes are expected to be somewhat redundant in their functionality, but have evolved from the single ancestral precursor gene in invertebrates to carry out unique functions, as evidenced by their divergent biophysical properties and protein–protein interaction motifs present within cytoplasmic regions.WIREs Membr Transp Signal2012, 1:467–491. doi: 10.1002/wmts.41

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