bluuebunny/crossref_metadata_2025 huggingface dataset:
Föhn as a response to changing upstream and downstream air masses
Authors: Mayr Georg J. , Armi Laurence
Published: September 2008

Observations of föhn from the field phase of the Mesoscale Alpine Programme (MAP) are used to study how differences between the air masses upstream and downstream of the central Alpine crest determine whether the flow can descend to the lee as either shallow föhn, when it passes through passes in the mountains, or deep föhn, when it overflows the Alpine crest. First, the föhn case of 30 October 1999 is examined using ECMWF analyses and radiosonde data at various upstream and downstream locations. Additional measurements from aircraft, dropsondes, an instrumented car and automatic weather stations are then used for a detailed study of the föhn flow across the Brenner Pass. Advection of cold air around the eastern edges of the Alps and warm air around the western edge of the Alps ahead of a synoptic ridge set up a reservoir of colder air on the south side of the Alps and a reservoir of warmer air to the north. The depth to where the air was colder on the southern side was sufficient for a shallow föhn to flow through the pass. After the passage of the ridge axis, synoptic cold air advection provided another source of colder air, this time from the southwest, growing deeper with time and having a synoptically imposed cross‐barrier flow component. The maximum depth to where the air upstream was colder than downstream extended just above the peaks of the highest mountains. An analysis of the detailed measurements across the Brenner Pass showed that this depth was also the top of the layer that descended and accelerated down the lee slopes of the Wipp Valley. Upstream, air above the föhn layer had an even stronger cross‐barrier component yet did not descend because it did not have lower potential temperatures than the downstream side at that level. Deep föhn never developed.

An examination of other well‐documented MAP föhn cases confirmed the conclusion from the 30 October event that shallow and deep föhns – at least for the central Alps – are mostly a response to differences in air masses between the upstream and downstream side. A cross‐barrier component of the flow was only a modification but in itself not sufficient to cause the flow to both descend and accelerate down the lee slope, unless potential temperatures on the upstream side were lower in this layer than on the downstream side. Copyright © 2008 Royal Meteorological Society
The Monte Carlo Independent Column Approximation: an assessment using several global atmospheric models
Authors: Barker H. W. , Cole J. N. S. , Morcrette J.‐J. , Pincus R. , Räisänen P. , von Salzen K. , Vaillancourt P. A.
Published: September 2008

The Monte Carlo Independent Column Approximation (McICA) computes domain‐average, broadband radiative flux profiles within conventional global climate models (GCMs). While McICA is unbiased with respect to the full ICA, it generates, as a by‐product, random noise. If this by‐product leads to statistically significant impacts on GCM simulations, it could limit the usefulness of McICA. This paper assesses the impact of McICA's random noise on six GCMs. To this end, the GCMs performed ensembles of 14‐day long simulations for various renditions of McICA, each with differing amounts of random noise. As seen in the past, low‐cloud fraction and surface temperature were affected most by noise. However, all GCM simulations using operationally viable renditions of McICA showed no statistically significant impacts, even for precipitation ‐ a highly intermittent variable that one might expect to be sensitive to random fluctuations. Two GCMs showed statistically significant responses using an academic version of McICA that generates overly large sampling noise. Time series analyses of high‐resolution (i.e. typically 2‐hourly) data revealed that fluctuations associated with most variables and GCMs are immune to McICA noise. Moreover, the nature of these fluctuations can vary substantially among GCMs and most often they overwhelm any noise impacts. Overall, the results presented here corroborate a range of previous studies done on one GCM at a time: random noise produced by recommended versions of McICA has statistically insignificant effects on GCM simulations. Copyright © 2008 Royal Meteorological Society and Her Majesty in Right of Canada.
Lessons learnt from the operational 1D + 4D‐Var assimilation of rain‐ and cloud‐affected SSM/I observations at ECMWF
Authors: Geer Alan J. , Bauer Peter , Lopez Philippe
Published: September 2008

Rain‐ and cloud‐affected Special Sensor Microwave/Imager (SSM/I) observations are assimilated operationally at the European Centre for Medium‐Range Weather Forecasts (ECMWF). The four‐dimensional variational analysis (4D‐Var) assimilates total column water vapour (TCWV) derived from one‐dimensional variational retrievals (1D‐Var). From the SSM/I radiances, 1D‐Var retrieves surface wind and the vertical profiles of temperature, humidity, cloud and precipitation. The main shortcoming of the ‘1D + 4D‐Var’ technique is that, of all this information, only TCWV gets into the 4D‐Var analysis. More information could be used: the rainwater path agrees well, in an instantaneous comparison, with observations from the precipitation radar on the Tropical Rainfall Measuring Mission. There are other issues, however: the simplified moist physics operators used in 1D‐Var produce roughly twice the observed amount of rain, but the problem is masked by a sampling bias, which comes from applying 1D + 4D‐Var when the observations are cloudy or rainy, but not when the first guess is rainy or cloudy and the observations are clear. The shortcomings of 1D + 4D‐Var will be addressed by moving to a direct 4D‐Var assimilation which includes all SSM/I observations, whether clear, cloudy or rainy, in the same stream. Copyright © 2008 Royal Meteorological Society
Evaluation of the variational soil moisture assimilation scheme at Deutscher Wetterdienst
Authors: Hess Reinhold , Lange Martin , Wergen Werner
Published: September 2008

A two‐dimensional, variational soil moisture assimilation scheme has been in operational use at DWD since 2000. The same scheme was also used and evaluated in the EU‐funded project ELDAS. By design, the scheme leads to improved forecasts of screen level parameters. The present paper discusses if this is achieved in a physically consistent way so that the assimilation process results in more realistic soil water contents. It is shown that overall the scheme behaves well, both in the longer‐term mean and in individual cases. A remarkable result is that the assimilation process for soil moisture also leads to improved quality of precipitation forecasts. Nevertheless, erroneous precipitation forecasts remain the largest error source for soil moisture. The assimilation scheme can successfully compensate for these errors. Using observed precipitation would be better still.

The diagnostics also revealed some unwanted features. They include sometimes large and frequent assimilation changes in the lower layer of the soil model. Reasons for this are discussed and possible remedies suggested. Copyright © 2008 Royal Meteorological Society
A mass‐conservative version of the semi‐implicit semi‐Lagrangian HIRLAM
Authors: Lauritzen P. H. , Kaas E. , Machenhauer B. , Lindberg K.
Published: September 2008

A mass‐conservative version of the semi‐implicit semi‐Lagrangian High‐Resolution Limited‐Area Model (HIRLAM) is presented. The explicit continuity equation is solved with the so‐called cell‐integrated semi‐Lagrangian (CISL) method. To allow for long time steps, the CISL scheme is coupled with a recently developed semi‐implicit time‐stepping scheme that involves the same non‐complicated elliptic equation as in HIRLAM. Contrarily to the traditional semi‐Lagrangian method, the trajectories are backward in the horizontal and forward in the vertical, i.e. cells moving with the flow depart from model layers and arrive in a regular column, and their vertical displacements are computed from continuity of mass and hydrostatic balance in the arrival column. This involves just two‐dimensional upstream integrals and allows for a Lagrangian discretization of the energy conversion term in the thermodynamic equation.

Preliminary validation of the new model version is performed using an idealized baroclinic wave test case. The accuracy of the new formulation of HIRLAM is comparable to the reference version though it is slightly more diffusive. A main finding is that the new discretization of the energy conversion term leads to more accurate simulations compared to the traditional ‘Eulerian’ treatment. Copyright © 2008 Royal Meteorological Society
Using a neural network to benchmark a diagnostic parametrization: the Met Office's visibility scheme
Authors: Claxton B. M.
Published: September 2008

Within the Met Office's Unified Model the visibility is diagnosed from a set of the model's prognostic variables using a parametrization. This parametrization has been optimized to minimize the error in the model visibility, relative to observed visibility. The performance of the parametrization is dependant on two aspects; (1) the quality of the input meteorological variables and (2) the structure of the parametrization itself. This paper describes a technique for obtaining a quantitative assessment of how much improvement is possible in the structure of the visibility parametrization. This is achieved by constructing an alternative visibility diagnostic scheme using a neural network. This statistical model provides a benchmark against which the performance of the current visibility parametrization can be judged, irrespective of the input error. It was found that the neural network achieved significant improvements over the current diagnostic parametrization: a 22% improvement in the geometric mean of the fractional error, and a 15% improvement in the geometric variance of the fractional error. ©Crown Copyright 2008. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Meta‐analysis of skewed data: Combining results reported on log‐transformed or raw scales
Authors: Higgins Julian P. T. , White Ian R. , Anzures‐Cabrera Judith
Published: September 2008

When literature‐based meta‐analyses involve outcomes with skewed distributions, the best available data can sometimes be a mixture of results presented on the raw scale and results presented on the logarithmic scale. We review and develop methods for transforming between these results for two‐group studies, such as clinical trials and prospective or cross‐sectional epidemiological studies. These allow meta‐analyses to be conducted using all studies and on a common scale. The methods can also be used to produce a meta‐analysis of ratios of geometric means when skewed data are reported on the raw scale for every study. We compare three methods, two of which have alternative standard error formulae, in an application and in a series of simulation studies. We conclude that an approach based on a log‐normal assumption for the raw data is reasonably robust to different true distributions; and we provide new standard error approximations for this method. An assumption can be made that the standard deviations in the two groups are equal. This increases precision of the estimates, but if incorrect can lead to very misleading results. Copyright © 2008 John Wiley & Sons, Ltd.
Assignment of pre‐edge peaks in K‐edge x‐ray absorption spectra of 3d transition metal compounds: electric dipole or quadrupole?
Authors: Yamamoto Takashi
Published: September 2008

The characteristics of pre‐edge peaks in K‐edge x‐ray absorption near edge structure (XANES) spectra of 3d transition metals were reviewed from viewpoints of the selection rule, coordination number, number of d‐electrons, and symmetry of the coordination sphere. The contribution of the electric dipole and quadrupole transition to the peaks was discussed on the basis of the group theory, polarized spectra, and theoretical calculations. The pre‐edge peak intensity for Td symmetry is larger than those for Oh symmetry for all 3d elements. The intense pre‐edge peak for tetrahedral species of 3d transition metals is not due to 1s–3d transition, but transition to the p component in d–p hybridized orbital. The mixing of metal 4p orbitals with the 3d orbitals depends strongly on the coordination symmetry, and the possibility is predictable by group theory. The transition of 1s electron to d orbitals is electric quadrupole component in any of the symmetries. The d–p hybridization does not occur with regular octahedral symmetry, and the weak pre‐edge peak consists of 1s–3d electric quadrupole transition. The pre‐edge peak intensity for a compound with a tetrahedral center changes as a function of the number of 3d electrons regardless of the kind of element; it is maximized at d0 and gradually decreases to zero at d10. The features of pre‐edge peaks in K‐edge XANES spectra for 4d elements and the L1‐edge for 5d elements are analogous with those for 3d elements, but the pre‐edge peak is broadened due to the wide natural width of the core level. Copyright © 2008 John Wiley & Sons, Ltd.
Results of a Multimodal Therapy in Patients with Stage IV Barrett’s Adenocarcinoma
Authors: Schauer Matthias , Stein Hubert , Lordick Florian , Feith Marcus , Theisen Joerg , Siewert Joerg Ruediger
Published: September 2008

Background

Locally advanced and metastatic Barrett’s carcinomas account for the majority of this tumor entity at the time of diagnosis. Many studies have shown that a multimodal therapy concept consisting of neoadjuvant chemotherapy followed by resection can result in improved long‐term survival in patients responding to chemotherapy. The benefit of a multimodal therapy concept in patients with stage IV disease remains unclear.

Methods

A total of 178 patients with Barrett’s carcinoma who underwent multimodal therapy with resection of the tumor were reviewed. The pathological staging and the clinical course of patients with metastatic disease, who were treated equally, were compared to patients with locally advanced tumors.

Results

As expected, postoperative pathological staging showed that patients with metastatic disease have a more advanced T‐ and N‐status. Moreover, the histopathological response according to Becker showed a chemoresistence in 84% of cases with metastatic disease, whereas 54% of patients with locally advanced carcinomas had a good response rate. Overall survival was poor, with 9 months in the metastatic group.

Conclusions

This is the first study to compare the outcome of a modern multimodal therapy concept in patients with metastatic Barrett’s carcinoma in comparison to patients with the locally advanced form of the disease. There are profound differences in the two groups with regard to survival time and response rates. Because of the poor outcome to date, multimodal therapy with resection of the tumor in stage IV disease cannot be recommended.
Identification of amino acid residues important for the phosphomannose isomerase activity of PslB in Pseudomonas aeruginosa PAO1
Authors: Lee Hui-Ju , Chang Hwan-You , Venkatesan Nandinin , Peng Hwei-Ling
Published: September 2008

Phosphomannose isomerase (PMI) plays a pivotal role in biosynthesis of GDP‐mannose, an important precursor of many polysaccharides. We demonstrate in this study that Pseudomonas aeruginosa pslB encodes a protein with GDP‐mannose pyrophosphorylase/PMI dual activities. The PMI activity is Co2+‐dependent and could be inhibited by GDP‐mannose in a competitive manner. Furthermore, the activity could be inactivated by 2,3‐butanedione suggesting the presence of a catalytic Arg residue. Site‐specific mutations at R373, R472, R479, E410, H411, N433 and E458 increase the K
M approximately 8–20‐fold. The PMI activity of PslB was completely diminished with a R408K or R408A, reflecting the importance of this residue in catalysis. Overall, these results provide a basis for understanding the catalytic mechanism of PMI.
Suppressor of cytokine signaling‐1 reduces high glucose‐induced TGF‐β1 and fibronectin synthesis in human mesangial cells
Authors: Shi Yonghong , Zhang Yanling , Wang Chen , Du Chunyang , Zhao Song , Qi Zhao , Zhang Qingxian , Duan Huijun
Published: September 2008

Janus kinase (JAK) signal transducers, and activators of transcription (STAT), contribute to diabetic nephropathy. Here we show that one of the suppressors of cytokine signaling (SOCS) proteins, SOCS‐1, was upregulated in human mesangial cells (HMCs) under high glucose conditions, along with the activation of JAK2, STAT1, and STAT3. Overexpression of SOCS‐1 in HMCs inhibited HG‐induced JAK2/STAT activation, c‐Fos/c‐Jun expression, and increased synthesis of TGF‐β1 and fibronectin. These data suggest that SOCS‐1 inhibits HG‐induced overexpression of TGF‐β1 and synthesis of fibronectin in HMC, which may be via JAK/STAT pathway.
Circulating tumour cells as a predictive factor for response to systemic chemotherapy in patients with advanced colorectal cancer
Authors: Lankiewicz Silke , Zimmermann Silke , Hollmann Christiane , Hillemann Tina , Greten Tim F.
Published: September 2008

Circulating tumour cells (CTC) can be traced in patients with different types of cancer. The aim of this study was to detect CTC in patients with advanced colorectal cancer and whether CTC are still detectable after systemic chemotherapy. Blood from 34 patients with advanced colorectal cancer was analysed for the presence of CTC before chemotherapy was given and after 3months. Eleven patients demonstrated a tumour remission after chemotherapy. In 6 cases CTC were detectable before but not after initiation of chemotherapy. Ten patients demonstrated a progression. In 5 cases CTC were detected before and after chemotherapy. Our data suggest that the detection of CTC will help to identify patients responding to chemotherapy or with a risk of a therapy failure.
Information contents misjudged: Digressive convergence to equilibrium in cointegrated prices
Authors: Tswei Keshin , Lai Jing‐yi
Published: September 2008

The spot price on the Taiwan stock index is richer in information than the futures price judged by the price discovery measures of Gonzalo and Granger [Gonzalo, J., & Granger, C.W.J. (1995). Estimation of common long‐memory components in cointegrated systems. Journal of Business and Economic Statistics, 13, 27–35.] and Hasbrouck [Hasbrouck, J. (1995). One security, many markets: Determining the contributions to price discovery. Journal of Finance, 50, 1175–1199.]. What is special about the markets is that both the spot and futures error‐correction coefficients are positive, implying a digressive convergence to their long‐run equilibrium in the error‐correction (EC) process. Innovation accounting suggests that the cause of this digressive equilibrium adjustment is that investors systematically overreact to news in the less informative futures market but under‐react to the more informative spot market. Our contribution is in identifying the digressive convergence implied by same‐sign EC coefficients, comparing it to the normal convergence widely found in opposite‐sign EC models, and providing short‐run mispricing interpretations for both types of convergence to equilibrium.
Association of Apolipoprotein E Polymorphism with Ischemic Stroke Subtypes in Taiwan
Authors: Lai Chiou‐Lian , Liu Ching‐Kuan , Lin Ruey‐Tay , Tai Chih‐Ta
Published: September 2008

The aim of this study was to clarify whether the apolipoprotein E gene (APOE) is related to ischemic stroke subtypes in Taiwan's Chinese population. Using the classification of Cerebrovascular Diseases III, 143 patients with lacunar infarction, 114 patients with atherothrombotic infarction, and 112 healthy controls were enrolled.APOEgenotype was determined using polymerase chain reaction. Regarding the distribution ofAPOEgenotypes, the frequency of ɛ3/ɛ4 genotypes in lacunar patients was significantly different from that in control subjects, by logistic regression, using ɛ3/ɛ3 as a reference group. There was no significant difference between atherothrombotic patients and the control group in the distribution ofAPOEgenotypes or alleles. The present finding suggests that there is a probable association between ɛ3/ɛ4 genotype and lacunar infarcts, but not atherothrombotic infarcts. This indicates that genetic factors may play a role, at least partially, in lacunar infarction in Taiwan's Chinese population.
Lightwand‐Guided Endotracheal Intubation Performed by the Nondominant Hand is Feasible
Authors: Kuo Yi‐Wei , Yen Mu‐Ken , Cheng Kuang‐I , Tang Chao‐Shuan , Chau Siu‐Wah , Hou Ming‐Fung , Wang Jhi‐Jong , Lin Shu‐Fen
Published: September 2008

The aim of this study was to evaluate the efficiency of lightwand‐guided endotracheal intubation (LWEI) performed using either the right (dominant) or left (nondominant) hand. Two hundred and forty patients aged 21–64 years, with a Mallampati airway classification grade of I—II and undergoing endotracheal intubation under general anesthesia, were enrolled in this randomized and controlled study. Induction of anesthesia was initiated by intravenous administration of fentanyl (2 mg/kg) and thiopentone (5mg/kg), and tracheal intubation was facilitated by intravenous atracurium (0.5 mg/kg). In the direct‐vision laryngoscope group (group D; n = 80), the intubator held the laryngoscope in the left hand and inserted the endotracheal tube (ETT) into the glottic opening with the right hand. In the group in which LWEI was performed with the right hand (group R; n = 80), the intubator lifted the patients' jaws with the left hand and inserted the ETT‐LW unit into the glottic openings with the right hand. On the contrary, in the group in which LWEI was performed with the left hand (group L; n = 80), the intubator lifted the jaws with the right hand and inserted the ETT‐LW unit with the left hand. Data including total intubation time, the number of intubation attempts, hemodynamic changes during intubation, and side effects following intubation, were collected. Regardless of whether lightwand manipulation was performed with the left hand (group L; 11.4 ± 9.3 s) or the right‐hand (group R; 12.4 ± 9.2 s), less time was consumed in the LWEI groups than in the laryngoscope group (group D; 17.9 ± 9.9s) (p < 0.001). All three groups obtained success rates > 95% on their first intubation attempts. The changes in mean arterial blood pressure and heart rate were similar among the three groups. A higher incidence of intubation‐related oral injury and ventricular premature contractions (VPC) was found in group D compared with groups L and R (oral injury: group D 8.5%, group L 1.3%, group R 0%, p = 0.005; VPC: group D 16.3%, group L 5%, group R 7.5%, p = 0.04). We concluded that LWEI performed by either dominant or nondominant hands resulted in similar efficiency, and could be a suitable alternative to traditional laryngoscopy. It is both feasible and logical for an experienced anesthesiologist to use the nondominant hand to perform LWEI.
Management of Poisonous Snake Bites in Southern Taiwan
Authors: Chang Kao‐Ping , Lai Chung‐Sheng , Lin Sin‐Daw
Published: September 2008

Snake bite envenomation is not uncommon in Taiwan. This study focuses on the pattern of poisonous snake bites and their management in southern Taiwan over a 5‐year period. The case histories of 37 patients with poisonous snake bites admitted to the Kaohsiung Medical University Hospital between June 2001 and July 2005 were analyzed retrospectively. Three patients, bitten by unknown species of venomous snakes, were excluded from this study. The frequency of snake bites from each species of snake, the local and systemic manifestations of snake bite, treatment of complications and final outcomes were analyzed. Of the remaining 34 patients, 11 (32.4%) were bitten by bamboo vipers, 10 (29.4%) by Russell's pit vipers, 8 (23.5%) by Taiwan cobras and 5 (14.7%) by Taiwan Habu. The majority of snake bites (28) occurred between May and November. Those affected were mainly outdoor hikers (14) and workers (9). The antivenin requirements for treatment in the emergency room were in accordance with standard procedures. No mortality was noted among those envenomed by poisonous snakes. Although poisonous snake bite is not a common life‐threatening emergency in the study area, we observed both an environmental risk and a seasonal incidence of snake bite. Keeping the varied clinical manifestations of snake bite in mind is important for effective management. Ready availability and appropriate use of antivenin, close monitoring of patients, institution of ventilatory support and early referral to a larger hospital when required, all help reduce mortality.
Three‐dimensional Relationship of the Maxillary Anterior Teeth to the Incisive Papilla in Young Adults
Authors: Fu Po‐Sung , Hung Chun‐Cheng , Hong Jau‐Ming , Wang Jen‐Chyan , Tsai Ching‐Fang , Wu Yi‐Min
Published: September 2008

The use of the incisive papilla as an important guide for setting maxillary teeth has been applied in prosthetic dentistry. The purpose of this study was to estimate the relationship between maxillary anterior teeth and the incisive papilla of young adults with approximately optimal occlusion in Taiwan. Study casts of 100 young adults (50 males, 50 females; mean age, 22.4 years) were selected in this study. All of the marked points on maxillary casts were measured using a three‐dimensional precise measuring device. The relative positions of maxillary teeth landmarks to incisive papilla were measured and analyzed using SAS software (JMP 4.02). Student's t test and Pearson's correlation test were used to test the statistical significance of any differences (p < 0.05). The results showed that the mesiolabial incisal edge of the upper central incisor was 7.30 ± 0.64mm anterior to the center of the incisive papilla. There was no significant difference in gender (p > 0.05). The intercanine line was 0.27 ± 1.30 mm posterior to the center of incisive papilla. There was no significant difference in gender (p > 0.05). The horizontal distances of the mesiolabial incisal edge of the upper central incisor and the intercanine line to the center of the incisive papilla showed only weak correlation (r < 0.5). In addition, the three‐dimensional relationship of maxillary anterior teeth to the center of the incisive papilla was measured and analyzed. We suggest using the incisive papilla as a reference landmark for the setting of maxillary anterior teeth.
Insulinoma‐associated Transient Hypothalamus—Pituitary—Adrenal Axis Impairment and Amelioration by Steroid Therapy and Surgical Intervention: A Case Report
Authors: Chang Yu‐Hung , Hsieh Ming‐Chia , Hsin Shih‐Chieh , Shin Shyi‐Jang , Lin Kun‐Der
Published: September 2008

Insulinoma is the most common functional tumor among pancreatic islet cell tumors. This type of tumor is difficult to localize prior to surgery and can lead to serious hypoglycemia. This paper presents the case of a young female who suffered from insulinoma associated with transient hypothalamus—pituitary—adrenal axis impairment. To localize her insulinoma, we used two alternative testing methods, somatostatin receptor scintigraphy and selective arterial calcium stimulation with venous sampling, after a failure of conventional imaging methods. We treated her adrenal insufficiency and prevented serious hypoglycemia by giving her prednisolone. The impairment in her hypothalamus—pituitary—adrenal axis and her serious hypoglycemia recovered after excision of the tumor.
Reconstruction of the Soft Palate In Oral Cancer to Repair an Operative Defect with Speech Aid Prosthesis: A Case Report
Authors: Wang Chau‐Hsiang , Huang I‐Yeuh , Du Je‐Kang , Chen Jen‐Hao , Lee Huey‐Er , Lee Ka‐Wo , Wu Ju‐Hui
Published: September 2008

A soft palate defect may result from surgical resection, and its consequences could include hypernasal speech and nasal regurgitation of food and liquids. A speech aid prosthesis fabricated for patients can improve nasal emission during speech, and assist in preventing nasal regurgitation of food. This article presents a case of the reconstruction of a soft palate defect by prosthetic obturation.
JACOBI-LIKE FORMS, PSEUDODIFFERENTIAL OPERATORS, AND GROUP COHOMOLOGY
Authors: LEE MIN HO
Published: September 2008

Pseudodifferential operators are formal Laurent series in the formal inverse ∂−1 of the derivative operator ∂ whose coefficients are holomorphic functions on the Poincaré upper half-plane. Given a discrete subgroup Γ of SL(2,ℝ), automorphic pseudodifferential operators for Γ are pseudodifferential operators that are Γ-invariant, and they are closely linked to Jacobi-like forms and modular forms for Γ. We construct linear maps from the space of automorphic pseudodifferential operators and from the space of Jacobi-like forms for Γ to the cohomology space of the group Γ, and prove that these maps are compatible with the respective Hecke operator actions.
ON SUPERNILPOTENT NONSPECIAL RADICALS
Authors: FRANCE-JACKSON HALINA
Published: September 2008

Let ρ be a supernilpotent radical. Let ρ* be the class of all rings A such that either A is a simple ring in ρ or the factor ring A/I is in ρ for every nonzero ideal I of A and every minimal ideal M of A is in ρ. Let $\mathcal {L}\left ( \rho ^{\ast }\right ) $ be the lower radical determined by ρ* and let ρφ denote the upper radical determined by the class of all subdirectly irreducible rings with ρ-semisimple hearts. Le Roux and Heyman proved that $\mathcal {L}\left ( \rho ^{\ast }\right ) $ is a supernilpotent radical with $\rho \subseteq \mathcal {L}\left ( \rho ^{\ast }\right ) \subseteq \rho _{\varphi }$ and they asked whether $\mathcal {L} \left ( \rho ^{\ast }\right ) =\rho _{\varphi }$ if ρ is replaced by β, ℒ , 𝒩 or 𝒥 , where β, ℒ , 𝒩 and 𝒥 denote the Baer, the Levitzki, the Koethe and the Jacobson radical, respectively. In the present paper we will give a negative answer to this question by showing that if ρ is a supernilpotent radical whose semisimple class contains a nonzero nonsimple * -ring without minimal ideals, then $\mathcal {L}\left ( \rho ^{\ast }\right ) $ is a nonspecial radical and consequently $\mathcal {L}\left ( \rho ^{\ast }\right ) \neq \rho _{\varphi }$. We recall that a prime ring A is a * -ring if A/I is in β for every $0\neq I\vartriangleleft A$.
CONTINUITY OF WEIGHTED COMPOSITION OPERATORS BETWEEN WEIGHTED BLOCH TYPE SPACES
Authors: WOLF ELKE
Published: September 2008

Let ϕ:D→Dandψ:D→ℂ be analytic maps. These induce a weighted composition operatorψCϕacting between weighted Bloch type spaces. Under some assumptions on the weights we give a necessary as well as a sufficient condition when such an operator is continuous.
Organic block coatings in block-and-ash flow deposits at Merapi Volcano, central Java
Authors: DONOGHUE E. , TROLL V. R. , SCHWARZKOPF L. M. , CLAYTON G. , GOODHUE R.
Published: September 2008

The 1954, 1994, 1998 and 2006 block-and-ash flow deposits from Merapi volcano, Indonesia, contain andesite blocks that display localized, dark surface coatings. These coated blocks are typically found in clusters, but may also occur isolated within the block-and-ash flow deposits. The coatings form irregular patches (tens of centimetres across) on block surfaces, and are characterized by a silver, metallic appearance. The origin and composition of the coatings have not previously been determined, and no comparable deposits have been described in detail from any other volcanically active region of the world. Carbon isotope analyses of coated and uncoated bulk rock material, and of a range of charred and uncharred wood samples, suggest that the dark block coatings at Merapi volcano are organic in origin. Scanning electron microscopy and reflected light microscopy indicate that such coatings may form due to the migration and subsequent deposition of organic carbon in cavities within the andesite blocks. The most recent field evidence from the 2006 block-and-ash flow deposits at Merapi indicates that in situ charcoalification of plant material after block deposition and/or during the final stages of flow, is the major mechanism that forms localized concentrations of block coatings. Isolated coated blocks may result either from recycling of older deposits, or, more likely, from charcoalification and redistribution of plant material caught between colliding lava blocks during flow.
Geochemical constraints on the origin of enigmatic cemented chalks, Norfolk, UK
Authors: WOOLHOUSE G. , ANDREWS J. E. , MARCA-BELL A. , DENNIS P. F.
Published: September 2008

Very hard cemented chalk stacks and crusts found locally in the upper part of the Cretaceous Chalk of north Norfolk, UK, are related to solution features. The solution features, mainly pipes and caves, formed after deposition of the overlying Middle Pleistocene Wroxham Crag, probably by routing of sub-glacial, or glacial, melt-waters derived from late Pleistocene glaciers. New geochemical (particularly stable isotope) data shows that cementation of the chalks, although related spatially to the solution features, was not caused by glacier-derived waters. The carbon isotope composition of the chalk cements is typically around −9.5‰, indicative of biologically active soils. Moreover, the oxygen isotope compositions of the cements, around −5‰, are incompatible with water δ18O values much below −9 to −10‰ (which probably precludes isotopically negative glacier-derived water), as resulting palaeo-temperatures are below zero. Taken together, the isotope data suggest chalk cementation occurred under interglacial conditions similar to the present. Dissolved calcium carbonate for cementation came from dissolution of reworked chalk in overlying MIS 12 glacial tills.
Dehydration, melting and related garnet growth in the deep root of the Amalaoulaou Neoproterozoic magmatic arc (Gourma, NE Mali)
Authors: BERGER JULIEN , CABY RENAUD , LIÉGEOIS JEAN-PAUL , MERCIER JEAN-CLAUDE C. , DEMAIFFE DANIEL
Published: September 2008

The Amalaoulaou Neoproterozoic island-arc massif belongs to the Gourma belt in Mali. The metagabbros and pyroxenites forming the main body of this arc root show the pervasive development of garnet. In the pyroxenites, the latter has grown by reaction between pyroxene and spinel during isobaric cooling. By contrast, in the metagabbros, garnet textures and relations to felsic veins exclude an origin through solid-state reactions only. It is proposed that garnet has grown following dehydration and localized melting of amphibole-bearing gabbros at the base of the arc. The plagioclase-saturated melts represented by anorthositic veins in the metagabbros and by trondhjemites in the upper part of the massif provide evidence for melting in the deep arc crust, which locally generated high-density garnet–clinopyroxene–rutile residues. Garnet growth and melting began around 850 °C at 10 kbar and the tonalitic melts were most probably generated around 1050 °C at P ≥ 10 kbar. This HT granulitic imprint can be related to arc maturation, leading to a P–T increase in the deep arc root and dehydration and/or dehydration-melting of amphibole-bearing gabbros. Observation of such features in the root of this Neoproterozoic island arc has important consequences, as it provides a link to models concerning the early generation of continental crust.
Sentinel lymph node biopsy in node-negative squamous cell carcinoma of the oral cavity and oropharynx
Authors: Burns P , Foster A , Walshe P , O'Dwyer T
Published: September 2008

Objectives:

Considerable controversy exists regarding the merits of elective neck dissection in patients with early stage oral cavity and oropharyngeal squamous cell carcinoma. It is highly desirable to have a method of identifying those patients who would benefit from further treatment of the neck when they are clinically node-negative. The purpose of the present study was to examine the use of sentinel lymph node biopsy in identifying occult neck disease in a cohort of patients with node-negative oral cavity and oropharyngeal squamous cell carcinoma.

Design:

We evaluated a total of 13 patients with oral cavity and oropharyngeal cancer who were clinically and radiologically node-negative.

Results:

A sentinel lymph node was found in all 13 patients, revealing metastatic disease in five patients, four of whom had one or more positive sentinel lymph nodes. There was one false negative result, in which the sentinel lymph node was negative for tumour whereas histological examination of the neck dissection specimen showed occult disease.

Conclusion:

In view of these findings, we would recommend the use of sentinel lymph node biopsy in cases of oral cavity and oropharyngeal squamous cell carcinoma, in order to aid the differentiation of those patients whose necks are harbouring occult disease and who require further treatment.
The septal body revisited
Authors: Elwany S , Salam S A , Soliman A , Medanni A , Talaat E
Published: September 2008

Introduction:

The term septal body refers to a thickened area of the nasal septum which is located superior to the inferior turbinate and anterior to the middle turbinate. Despite its important role in changing nasal airflow resistance, it has received little attention. Clinically, a well developed septal body may be misdiagnosed as high septal deviation.

Aim:

The aim of the present study was to reassess the histological characteristics of the septal body mucosa and the morphometric differences between it and the adjacent septal mucosa. This information was then used to determine the exact location and surface area of the septal body.

Materials and methods:

The study was performed on 30 cadaveric specimens (60 sides). Serial numbered sections of the whole septal mucosa were stained with haematoxylin and eosin as well as periodic acid Schiff – Alcian blue. Morphometric analysis was performed to determine the histological differences between the septal body mucosa, the anterior septal mucosa and the inferior septal mucosa. The precise boundaries of the septal body area were then defined in a manner similar to the Mohs micrographic surgical technique.

Results:

The histological characteristics of the septal body mucosa included thick (more than 60 µm), pseudostratified, ciliated respiratory epithelium with goblet cells, abundant seromucinous glands and many blood sinusoids. Morphometric analysis showed that the septal body mucosa had thicker epithelium and more glandular acini and blood sinusoids than the rest of the septal mucosa. Mapping of the septal body area showed that its anterior end was 2.2 ± 0.3 cm (mean ± standard deviation) behind the caudal edge of the septal cartilage, and its inferior border was 1.1 ± 0.2 cm above the floor of the nose. The mean horizontal diameter of the septal body was 2.0 ± 0.15 cm, and the mean vertical diameter was 1.5 ± 0.11 cm.

Conclusions:

The present study determined the morphometric characteristics of the septal body as well as its location and surface area. The intimate relationship of the septal body to the internal nasal valve and the histological characteristics of its mucosa should stimulate research into its potential role in modifying nasal airflow pattern and resistance, and its role in changing the humidity and temperature of the inspiratory air stream.
Development of cavernous haemangioma following radical chemo-radiotherapy for nasopharyngeal carcinoma
Authors: Ellenbogen J R , Joshi S M , Kitchen N
Published: September 2008

Objective:

We report an adult case of nasopharyngeal carcinoma treated with radical chemo-radiotherapy, with subsequent development of a histologically proved temporal cavernous haemangioma within the radiation field.

Method:

Case report and review of the current literature concerning radiation-induced, secondary, space-occupying lesions.

Conclusion:

The increasing role of radiotherapy in nasopharyngeal carcinoma treatment, together with improved patient survival, is likely to lead to radiation-induced, secondary, space-occupying lesions being encountered more frequently. We emphasise the need to be vigilant for this important but relatively rare complication, which has significant associated morbidity.
Avian influenza viruses detected by surveillance of waterfowl in Ireland during 2003–2007
Authors: RALEIGH P. J. , FLYNN O. , O'CONNOR M. , O'DONOVAN T. , PURCELL B. , DE BURCA M. , REGAZZOLI V. , MINIHAN D. , CONNELL J. , MARKEY B. K. , SAMMIN D. J.
Published: September 2008

Specimens for the detection of avian influenza virus (AIV) were collected from 1937 waterfowl on the Wexford Sloblands, a major wetland reserve in southeast Ireland, between January 2003 and September 2007. During the same period, 1404 waterfowl were sampled at other locations in Ireland. Specimens were tested either by virus isolation or real-time reverse transcriptase polymerase chain reaction (rtRT–PCR). A total of 32 isolates of AIV, comprising nine subtypes, was obtained from specimens from the Sloblands compared with just one isolate from elsewhere in Ireland. Samples from nine other waterfowl, five of which were from the Sloblands, tested positive for AIV by rtRT–PCR. Ecological factors are likely to have contributed to the higher detection rate of AIV at the Sloblands compared with the rest of Ireland. It was concluded that targeted surveillance at such sites is a cost-effective means of monitoring the circulation of new AIVs in waterfowl, whereas widespread opportunistic sampling is unproductive and wasteful of resources.
A ten year review of atrioventricular septal defects
Authors: Dunlop Kathryn A. , Mulholland H. Connor , Casey Frank A. , Craig Brain , Gladstone Dennis J.
Published: September 2008

Objectives:To review all cases of atrioventricular septal defects in Northern Ireland from January 1990 to February 1999, examining clinical and morphological features, management, and outcome.Methods:A retrospective case note analysis of 106 subjects with comparisons between subgroups.Results:An atrioventricular septal defect was part of a more complex abnormality in 50 of the patients (47%). Down's syndrome was present in 57 (54%). Cardiac surgery was performed in 81%. The defects were unrestrictive in 69 patients (65%), 45 of whom had Down's syndrome. Complex associated abnormalities existed in 36 patients, and 10 of these died without cardiac surgery. Operative mortality was 9.5% for those with co-existing Down's syndrome group, and 14.3% for the chromosomally normal patients. The ventricular components of the septal defect were restrictive in 23 patients (22%), with 9 having Down's syndrome. Spontaneous closure occurred in more than half of these patients. Mortality was zero. The septal defect was exclusively at atrial level in 14 patients (“primum” defects – 13%), and 3 of these had Down's syndrome. Operative mortality was again zero. Median duration of postoperative follow-up was 3 and a half years. Overall, moderate to severe left atrioventricular valvar regurgitation was observed postoperatively in 23% at follow-up.Conclusions:Mortality was highest in the atrioventricular septal defects with an unrestrictive ventricular component. Uncomplicated cases had good outcomes. Patients without Down's syndrome tended to have more associated cardiac abnormalities, and to have more postoperative arrhythmias. Approximately half of the defects with restrictive ventricular components closed spontaneously. Moderate postoperative left atrioventricular valvar regurgitation was commonest in patients with the defect exclusively at atrial level.
Long-term survival in children with atrioventricular septal defect and common atrioventricular valvar orifice in Sweden
Authors: Frid Christina , Björkhem Gudrun , Jonzon Anders , Sunnegårdh Jan , Annerén Göran , Lundell Bo
Published: September 2008

Background:The survival for patients with atrioventricular septal defect has improved markedly over the last decades and, during the same period, the survival of children with Down's syndrome has also increased. The aim of our study was to investigate long-term survival in patients having atrioventricular septal defect with common valvar orifice, but without associated significant congenital heart defects, in the setting of Down's syndrome, comparing the findings to those in chromosomally normal children with the same malformation.Methods and results:In a population-based retrospective study, we scrutinised the medical records from 801 liveborn children with atrioventricular septal defect born in Sweden during the period 1973 through 1997. Data on gender, presence or absence of Down's syndrome, associated congenital heart defects, date of birth, operation and death were recorded and followed up until 2001. An isolated atrioventricular septal defect with common atrioventricular valvar orifice was present in 502 children, of whom 86% had Down's syndrome. We found a significant reduction over time in age at operation, and in postoperative mortality at 30 days, from 28 to 1%. Using a multiple logistic regression model, we found no significant differences in mortality between genders, nor between those with or without Down's syndrome. Early corrective surgery could not be identified as a significant independent factor for survival. The 5-year postoperative survival in patients with Down's syndrome increased from 65% over the period from 1973 through 1977, to about 90% in the period 1993 through 1997, and the same trend was observed in chromosomally normal patients.Conclusions:Survival in uncomplicated atrioventricular septal defect with common atrioventricular valvar orifice has greatly increased, and surgical correction is now equally successful in patients with Down's syndrome and chromosomally normal patients, and for both genders. Death in connection with surgery is no longer the major threat, and focus must now be on long-term follow-up.
Repair of aortic coarctation using temporary ascending to descending aortic bypass in children with poor collateral circulation
Authors: Christenson Jan T. , Sierra Jorge , Didier Dominique , Beghetti Maurice , Kalangos Afksendiyos
Published: September 2008

Aortic coarctation can now be repaired surgically with excellent results. Even though rare, injury to the spinal cord resulting in paraplegia remains a major concern. Preoperative evaluation showing the absence of collateral circulation is valuable in order to introduce protective actions. This report describes our experience using a temporary bypass from the ascending to the descending aorta bypass in children undergoing surgical correction of aortic coarctation in the setting of poorly developed collateral circulation.

Between 1990 and 2002, we undertook direct surgical repair in 56 patients with isolated aortic coarctation, 20 as neonates, 11 as infants, and 25 during childhood. From 1998 onwards, we introduced preoperative evaluation of the collateral circulation with magnetic resonance imaging. From that time, we placed a temporary bypass from the ascending to the descending aorta, using a polytetrafluoroethylene tube of 4 to 8 mm diameter, whenever distal pressures were shown to be 25 mmHg or less after test clamping, or when magnetic resonance imaging revealed absence of collateral circulation.

We found excellent correlations between the direct intra-operative measurements of distal pressure and the findings at magnetic resonance imaging. Following introduction of the temporary bypass, we observed no neurological complications, nor were there any complications related to bypass. Freedom from restenosis was 96%.

Preoperative magnetic resonance imaging, therefore, can accurately visualize poor collateral circulation in children with aortic coarctation. The use of a temporary bypass can possibly eliminate the risk of neurological sequels following direct repair of coarctation in children with poorly developed collateral circulation. The temporary bypass is both easy to apply and safe.