bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel hydrogels from diepoxy‐terminated poly(ethylene glycol)s and aliphatic primary diamines: synthesis and equilibrium swelling studies
Authors: Teodorescu Mircea , Cursaru Bogdan , Stanescu Paul , Draghici Constantin , Stanciu Nicoleta Doriana , Vuluga Dumitru Mircea
Published: January 2009

New hydrogels were prepared from diepoxy‐terminated poly(ethylene glycol)s of approximate molecular weights 600, 1000, 2000, and 4000 Da and aliphatic primary diamines with different numbers of carbon atoms (ethylenediamine, 1,4‐diaminobutane, hexamethylenediamine, 1,8‐octanediamine, 1,10‐decanediamine, 1,12‐dodecanediamine), in water or ethanol–water mixture, depending on the amine solubility. The swelling behavior of these gels was tested in distilled water/aqueous solution at constant temperature and the equilibrium swelling degree (ESD) was determined for structurally different hydrogels and under various environmental conditions. It was shown that ESD was influenced by the molecular weight of PEG oligomers, amine/epoxy groups mole ratio, amine chain length, temperature, pH, and concentration of salts present in the swelling medium. Higher ESDs were obtained for either longer‐chain PEGs, non‐stoichiometric amine/epoxy groups ratio, shorter amines, acidic pH, lower temperatures, or in the absence of salts. Copyright © 2009 John Wiley & Sons, Ltd.
Severe neurologic side effects in patients being treated for hemophagocytic lymphohistiocytosis
Authors: Thompson Patrick A. , Allen Carl E. , Horton Terzah , Jones Jeremy Y. , Vinks Alexander A. , McClain Kenneth L.
Published: January 2009

Background

Hemophagocytic Lymphohistiocytosis (HLH) is characterized by uncontrolled inflammation that is generally fatal without immune modulating chemotherapy. At Texas Children's Hospital, we have observed significant central nervous system (CNS) toxicity in several patients treated for HLH according to the Histiocyte Society protocol HLH‐2004 in which cyclosporine is given early in the treatment regimen.

Methods

Patients diagnosed with HLH at Texas Children's Hospital between April 2004 and October 2007 were identified and charts were reviewed. A reference group of patients treated between August 2001 and March 2004, prior to the introduction of HLH‐2004, was also evaluated.

Results

Five of 17 patients in the study group developed severe neurotoxicity. Four had new onset seizures associated with significant MRI abnormalities, while the fifth died of intracerebral hemorrhage. Timing of the development of neurologic side effects ranged from day 5 to week 6 of therapy. Cyclosporine levels were outside the therapeutic range (200–300 ng/ml) prior to the onset of symptoms in two of the five patients. Systolic blood pressures for all five patients were greater than the 95th percentile for age on at least one measurement within 24 hr of the onset of neurologic symptoms. MRI scans obtained within 24 hr of seizure activity in four patients were consistent with posterior reversible encephalopathy syndrome (PRES). By comparison only one patient in the reference group (n = 15) had neurotoxicity (PRES).

Conclusions

Patients being treated for HLH appear to be at risk for neurotoxicity, particularly PRES. Elevated blood pressure, worsening renal and liver function, increased cyclosporine levels, and CNS involvement of HLH may be triggers for the neurotoxic side effects of treatment. Patients being treated on HLH‐2004 require close monitoring of their neurologic status and modifiable risk factors such as hypertension should managed aggressively. If larger studies validate our observations, it will be important to determine if up‐front cyclosporine in HLH protocols confers a survival benefit that outweighs the potential risk of increased neurotoxicity. Pediatr Blood Cancer 2009;52:621–625. © 2009 Wiley‐Liss, Inc.
Acquired factor VII deficiency associated with Wilms tumor
Authors: Granger Jeremy , Gidvani Vinod K.
Published: January 2009

We present the case of a 2‐year‐old female with Wilms tumor whose initial evaluation revealed a prolonged prothrombin time (PT) and normal activated partial thromboplastin time. Mixing studies demonstrated correction of the PT and the Factor VII activity was 17% in the absence of a Factor VII inhibitor. She underwent successful resection of the tumor with fresh frozen plasma support and no excessive bleeding. Post‐operative testing demonstrated normal PT at 3 days and 1‐month. Although acquired von Willebrand factor deficiency has a known association with Wilms tumor, paraneoplastic factor VII deficiency associated with Wilms tumor is previously unreported. Pediatr Blood Cancer 2009;52:394–395. © 2008 Wiley‐Liss, Inc.
Dissimilar hepatic protein expression profiles during the acute and flow phases following experimental thermal injury
Authors: Duan Xunbao , Berthiaume François , Yarmush David M. , Yarmush Martin L.
Published: January 2009

The liver plays a major role in the early hypometabolic and later hypermetabolic phases after severe burn injury. Proteomic analysis was used to identify altered proteins in liver during these two phases. Sprague‐Dawley rats were subjected to a full‐thickness dorsal burn injury covering 40% of the total body surface area. Controls consisted of sham‐treated animals. Liver tissues were collected on postburn days 1 and 7. The proteomic data show greater production of positive acute phase proteins on day 1 than on day 7. Many antioxidant enzymes were coordinately downregulated on day 1, including the potent biliverdin reductase. These antioxidants were restored and in some cases upregulated on day 7. This opposite trend in the change of antioxidant proteins corroborated our finding of more pronounced oxidative stress on day 1 than on day 7 as measured via protein carbonyl content. The changes of metabolic enzymes on days 1 and 7 were consistent with hypo‐ and hyper‐metabolic states, respectively. Furthermore, a previously unreported decrease in ornithine aminotransferase on day 7 may be a key contributor to the observed increased urinary urea excretion during the hypermetabolic phase. Overall, the many differences in protein expression observed on postburn days 1 and 7 reflect the dissimilar hepatic metabolic patterns during the acute and flow phases following burn injury.
A chip‐based amide‐HILIC LC/MS platform for glycosaminoglycan glycomics profiling
Authors: Staples Gregory O. , Bowman Michael J. , Costello Catherine E. , Hitchcock Alicia M. , Lau James M. , Leymarie Nancy , Miller Christine , Naimy Hicham , Shi Xiaofeng , Zaia Joseph
Published: January 2009

A key challenge to investigations into the functional roles of glycosaminoglycans (GAGs) in biological systems is the difficulty in achieving sensitive, stable, and reproducible mass spectrometric analysis. GAGs are linear carbohydrates with domains that vary in the extent of sulfation, acetylation, and uronic acid epimerization. It is of particular importance to determine spatial and temporal variations of GAG domain structures in biological tissues. In order to analyze GAGs from tissue, it is useful to couple MS with an on‐line separation system. The purposes of the separation system are both to remove components that inhibit GAG ionization and to enable the analysis of very complex mixtures. This contribution presents amide–silica hydrophilic interaction chromatography (HILIC) in a chip‐based format for LC/MS of heparin, heparan sulfate (HS) GAGs. The chip interface yields robust performance in the negative ion mode that is essential for GAGs and other acidic glycan classes while the built‐in trapping cartridge reduces background from the biological tissue matrix. The HILIC chromatographic separation is based on a combination of the glycan chain lengths and the numbers of hydrophobic acetate (Ac) groups and acidic sulfate groups. In summary, chip based amide‐HILIC LC/MS is an enabling technology for GAG glycomics profiling.
Multivariate analysis of single quadrupole LC‐MS spectra for routine characterization and quantification of intact proteins
Authors: Michaud François‐Thomas , Garnier Alain , Lemieux Lise , Duchesne Carl
Published: January 2009

Modern high‐throughput proteomic platforms allow incomparable protein mixture resolution and identification. However, such sophisticated facilities are expensive and not always accessible for routine analysis of simple mixtures. In this paper, we propose a simple methodology, based on detection of intact, nondigested proteins by LC coupled to single quadrupole MS (sqLC‐MS), followed by the analysis of the resulting spectra by multivariate analysis (MA). By doing so, even large molecular weight (MW) proteins, generating complex spectra, can be characterized to a level that allows isoform discrimination, while standard algorithms, such as MS spectrum deconvolution, cannot. To demonstrate the effectiveness of the proposed approach, we have analyzed the spectra of a set of purified, intact albumins from seven different organisms (bovine, human, rabbit, rat, sheep, mouse, and pig) as a model of microheterogenous proteins, using Projection to Latent Structure Discriminant Analysis (PLS‐DA). Although these proteins are very similar (less than 1% difference in MW), sqLC‐MS/MA allowed their classification, and the identification of unknown source samples. In addition, MA allowed precise protein quantification from the same data (calibration curve R2 = 0.9966). The ability to rapidly characterize and quantify proteins, together with simplicity and affordability, could make of combined sqLC‐MS/MA a routine method for the characterization of simple mixture of known proteins.
Mass spectrometric characterization of membrane integral low molecular weight proteins from photosystem II in barley etioplasts
Authors: Plöscher Matthias , Granvogl Bernhard , Zoryan Mikael , Reisinger Veronika , Eichacker Lutz Andreas
Published: January 2009

In Photosystem II (PSII), a high number of plastid encoded and membrane integral low molecular weight proteins smaller than 10 kDa, the proteins PsbE, F, H, I, J, K, L, M, N, Tc, Z and the nuclear encoded PsbW, X, Y1, Y2 proteins have been described. Here we show that all low molecular weight proteins of PSII already accumulate in the etioplast membrane fraction in darkness, whereas PsaI and PsaJ of photosystem I (PSI) represent the only low molecular weight proteins that do not accumulate in darkness. We found by BN‐PAGE separation of membrane protein complexes and selective MS that the accumulation of one‐helix proteins from PSII is light independent and occurs in etioplasts. In contrast, in chloroplasts isolated from light‐grown plants, low molecular weight proteins were found to specifically accumulate in PSI and II complexes. Our results demonstrate how plants grown in darkness prepare for the induction of chlorophyll dependent photosystem assembly upon light perception. We anticipate that our investigation will provide the essential means for the analysis of protein assembly in any membrane utilizing low molecular weight protein subunits.
Quality of life in the chemotherapy treatment of Spanish cancer patients: a comparison of general population norms
Authors: Costa‐Requena Gema , Gil Francisco
Published: January 2009

Objective: The SF‐36 Health Survey (SF‐36) is a general instrument used to assess health‐related quality of life (HRQL). The purpose of this study is to describe self‐reported information on health and the quality of life among cancer outpatients during chemotherapy treatment and to compare it with the baseline sample drawn from the general Spanish population.

Methods: A randomised sample of 583 cancer outpatients completed the questionnaire. Using a cross‐sectional analysis of the SF‐36 data, standardised scores were used to compare patients with comparative Spanish baseline data. Other health‐related concerns (gender, age, site of cancer) were also analysed.

Results: The patients showed acceptable levels on HRQL and no significant differences were found between the oncology patients compared with the general population for any of the SF‐36 domains. The older patients had scores significantly lower in physical functioning (p<0.01) and physical role (p<0.05). The results identified lower HRQL ratings among women compared with men on all the scales except general health. In relation to the location of the cancer, patients with genitourinary tumours scored statistically lower (p<0.05) on bodily pain in the SF‐36 domain compared with patients with gastrointestinal tumours.

Conclusions: Although more studies are needed, the SF‐36 allows us to describe the HRQL of cancer outpatients during chemotherapy treatment compared with the general population. Copyright © 2009 John Wiley & Sons, Ltd.
Cancer patients' decisions about discussing Internet information with their doctors
Authors: Bylund Carma L. , Gueguen Jennifer A. , D'Agostino Thomas A. , Imes Rebecca S. , Sonet Ellen
Published: January 2009

Objective: To explore cancer patients' and caregivers' decisions regarding whether to discuss cancer‐related information they found on the Internet with their doctors.

Methods: 238 participants (cancer patients and caregivers) from three online cancer communities responded to a survey about their experiences finding information on the Internet about their cancer and their reasons for discussing or not discussing that information with their doctors. The reasons were coded into mutually exclusive categories.

Results: Participants most frequently reported discussing information in order to be proactive in improving their health. Other reasons included appealing to the doctor as expert, wanting to become more educated, meeting a psychological or coping need, and checking up on or testing the doctor. Of the participants, caregivers were more likely than patients to cite checking up on or testing the doctor as a reason for discussing Internet information. Sixty‐two percent of participants reported sometimes or never talking about Internet information that they thought was important with their doctors. Across all participants, the most frequently reported reasons for not talking about Internet information were attributions about the information and systems‐related reasons. Participants who reported information attribution as a reason for not discussing it with their doctors had higher overall comfort levels with these types of discussions.

Conclusions: Many factors influence cancer patients' and caregivers' decisions about discussing Internet information with their doctors. The coherence of the reasons across the communities in this study and in other studies suggests that this typology of reasons is both thorough and valid. Copyright © 2009 John Wiley & Sons, Ltd.
No effect on survival of home psychosocial intervention in a randomized study of Danish colorectal cancer patients
Authors: Ross Lone , Frederiksen Kirsten , Boesen Sidsel H. , Karlsen Randi V. , Rasmussen Morten S. , Sørensen Lars T. , Jørgensen Torben , Claesson Mogens H. , Johansen Christoffer
Published: January 2009

Objective: We investigated whether regular home visits to persons with newly diagnosed colorectal cancer influenced their overall survival and selected immune parameters.

Methods: A total of 249 Danish colorectal cancer patients undergoing abdominal surgery were randomly assigned to a control or an intervention group. The intervention group received 10 home visits from a project nurse or a medical doctor during the first 2 years after discharge. The home visits aimed at providing emotional support and information. A subgroup of 55 patients provided blood samples 3, 12 and 24 months after discharge for measurement of immune parameters. Survival was assessed 6.5–9.5 years after the first operation.

Results: A total of 148 patients died during follow‐up. The intervention was not significantly associated with survival (p=0.68) after adjustment for Dukes' stage, radicality of the operation, age, sex, family social class and marital status. Likewise, no significant interactions were found between group and these covariates (allp⩾0.08). In the substudy of the possible effect of the intervention on immune parameters, there were no differences between the two groups with respect to lymphocyte proliferation (allp⩾0.078) or natural killer cell activity (allp⩾0.33) and no consistent effect on the number of specific subsets of cells (phenotypes) during follow‐up.

Conclusion: The study failed to provide evidence that the psychosocial intervention provided as home visits significantly affected the prognosis or selected immune parameters of patients who had undergone surgery for colorectal cancer. Copyright © 2009 John Wiley & Sons, Ltd.
Order and Disorder in Powder Mixtures: Spatial Distribution Functions as Tools to Assess Powder Homogeneity
Authors: Mihranyan Albert , Frenning Göran , Fransén Nelly , Welch Ken , Strømme Maria
Published: January 2009

In interactive mixtures with small carrier particles, the content variability is often higher than predicted by available models despite the significant degree of interaction visualized with Scanning Electron Microscopy (SEM). The present work details how pair‐correlation functions can be used to reveal information about the spatial distribution of mixture constituents and their interactions. SEM pictures of a 2 % w/w oxazepam/sodium starch glycolate (SSG) mixture were recorded (n= 14). The constituent coordinates were extracted and pair‐correlation functions as well as the cross‐correlation function were calculated. A significant degree of interaction was observed between the constituents in the experimental mixture, compared to a randomized control system. In particular, the probability of finding an oxazepam particle was especially high inside the perimeter of the carrier particle and along its edges. The observed cross‐correlation between oxazepam and SSG particles was periodic and repeated at distances corresponding to 1–1.5 carrier diameters. It was concluded that interactive mixtures of powders can be compared to disordered/amorphous solids since both exhibit short‐range order, whilst lacking long‐range translational periodicity.
The effect of fetal tracheal occlusion on lung tissue mechanics and tissue composition
Authors: Jani Jacques C. , Flemmer Andreas W. , Bergmann Florian , Gallot Denis , Roubliova Xenia , Muensterer Oliver J. , Hajek Kerstin , Deprest Jan A.
Published: January 2009

Fetal tracheal occlusion (TO) is currently used to treat severe cases of congenital diaphragmatic hernia (DH). Clinical and experimental studies suggest an improved postnatal outcome, but lung tissue mechanics after TO have not been studied. We determined the effect of TO on mechanical impedance and lung tissue components in a rabbit model for DH. At 23 days of gestation (term = 31 days) either a sham thoracotomy or a diaphragmatic defect was induced. DH fetuses were randomly assigned to undergo 5 days later TO. Fetuses were delivered by term cesarean section to determine lung to body weight ratio (LBWR), dynamic lung mechanics and lung impedance. Airway resistance (Raw), elastance (HL), tissue damping (GL) and hysteresivity (GL/HL) were calculated from impedance data. Collagen I and III and elastin were quantified histologically. LBWR was significantly increased by TO compared to DH (P < 0.001) and resistance and compliance of the respiratory system (Rrs, Crs) were improved as well. TO resulted in a significant decrease of Raw comparable to observations in sham‐fetuses, without effect on lung tissue mechanics HL, GL and hysteresivity. This coincides with a significant decrease of collagen I, III and elastin in comparison to DH fetuses. In this first report on lung tissue mechanics in a rabbit model of DH, TO had a substantial effect on tissue morphology yet this was not mirrored in lung mechanics. We conclude that the effect of TO on lung mechanics without in utero reversal of occlusion, is dominated by airway remodeling. Pediatr Pulmonol. 2009; 44:112–121. © 2009 Wiley‐Liss, Inc.
Recurrent severe lower respiratory tract infections in a child with abnormal tracheal morphology
Authors: Panigada Serena , Sacco Oliviero , Girosi Donata , Tomà Paolo , Rossi Giovanni A.
Published: January 2009

Localized recurrent respiratory infections, leading to severe hypoxia in young children without immunological abnormalities or other risk factors, should raise the suspicion of airway structural abnormalities. In a 24‐month‐old boy, with recurrent severe post‐viral wheezing and a history of RSV‐induced bronchiolitis and gastro‐esophageal reflux, fiberoptic bronchoscopy demonstrated an abnormal morphology of the distal portion of the trachea, ending in four openings. Computed tomography (CT) scans demonstrated the presence of a right tracheal bronchus and an anomalous upper lobar bronchus, originating at the level of the major carina. Pediatr Pulmonol. 2009; 44:192–194. © 2009 Wiley‐Liss, Inc.
Ciliopathy spectrum expanded? Jeune syndrome associated with foregut dysmotility and malrotation
Authors: Hall Tim , Bush Andrew , Fell John , Offiah Amaka , Smith Virpi , Abel Robin
Published: January 2009

We report the association and surgical management of gastrointestinal dysmotility and malrotation with Jeune asphyxiating thoracic dystrophy (JATD), an autosomal recessive condition that often results in respiratory failure due to a small rib cage. A 4‐month‐old male with JATD presented with vomiting and aspiration pneumonitis compounding already severe respiratory morbidity. A contrast study revealed esophageal and gastric dysmotility with associated malrotation. This was treated surgically with good results. Some cases of JATD are caused by missense mutations in the gene IFT80, which encodes a protein implicated in the process of intraflagellar transport of primary cilia. We speculate that these abdominal complications might also be part of the extending spectrum of ciliopathy. Pediatr Pulmonol. 2009; 44:198–201. © 2009 Wiley‐Liss, Inc.
Morpholinone mediated oxazolone‐free C‐terminus amide coupling permitting a convergent strategy for peptide synthesis
Authors: Harwood Laurence M. , Mountford Simon J. , Yan Ran
Published: January 2009

3‐Substituted‐5‐phenylmorpholinones have been demonstrated to act as N‐protected C‐terminus activated α‐amino acids capable of undergoing solution phase N‐terminus peptide extension following standard coupling procedures. The N‐acylated morpholinones do not undergo epimerisation of the stereocentre of the C‐terminus amino acid residue as oxazolone formation is sterically prevented, although C‐terminus peptide coupling is still possible. This convergent approach to peptide synthesis is exemplified by the preparation of L‐ala‐L‐ala‐L‐ala and L‐ala‐D‐ala‐L‐ala. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Identification and characterization of a novel heparin‐binding peptide for promoting osteoblast adhesion and proliferation by screening an Escherichia coli cell surface display peptide library
Authors: Kim Hyoun‐Ee , Kim Hae‐Won , Jang Jun‐Hyeog
Published: January 2009

Heparin/heparan sulfate (HS) plays a key role in cellular adhesion. In this study, we utilized a 12‐mer random Escherichia coli cell surface display library to identify the sequence, which binds to heparin. Isolated insert analysis revealed a novel heparin‐binding peptide sequence, VRRSKHGARKDR, designated as HBP12. Our analysis of the sequence alignment of heparin‐binding motifs known as the Cardin–Weintraub consensus (BBXB, where B is a basic residue) indicates that the HBP12 peptide sequence contains two consecutive heparin‐binding motifs (i.e. RRSK and RKDR). SPR‐based BIAcore technology demonstrated that the HBP12 peptide binds to heparin with high affinity (KD = 191 nM). The HBP12 peptide is found to bind the cell surface HS expressed by osteoblastic MC3T3 cells and promote HS‐dependent cell adhesion. Moreover, the surface‐immobilized HBP12 peptide on titanium substrates shows significant increases in the osteoblastic MC3T3‐E1 cell adhesion and proliferation. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Rapid detection of drugs in biofluids using atmospheric pressure chemi/chemical ionization mass spectrometry
Authors: Chen Lee Chuin , Hashimoto Yutaka , Furuya Hiroko , Takekawa Kenichi , Kubota Takeo , Hiraoka Kenzo
Published: January 2009

We have demonstrated that, with simple pH adjustment, volatile drugs such as methamphetamine, amphetamine, 3,4‐methylenedioxymethamphetamine (MDMA), ketamine, and valproic acid could be analyzed rapidly from raw biofluid samples (e.g. urine and serum) without dilution, or extraction, using atmospheric pressure ionization. The ion source was a variant type of atmospheric pressure chemical ionization (APCI) that used a dielectric barrier discharge (DBD) to generate the metastable helium gas and reagent ions. The sample solution was loaded in a disposable glass pipette, and the volatile compounds were purged by nitrogen gas to be reacted with the metastable helium gas. The electrodes of the DBD were arranged in such a way that the generated glow discharge was confined within the discharge tube and was not exposed to the analytes. A needle held at 100–500 V was placed between the ion‐sampling orifice and the discharge tube to guide the analyte ions into the mass spectrometer. After pH adjustment of the biofluid sample, the amphiphilic drugs were in the form of a water‐insoluble oil, which could be concentrated on the liquid surface. By gentle heating of the sample to increase the evaporation rate, rapid and sensitive detection of these drugs in raw urine and serum samples could be achieved in less than 2 min for each sample. Copyright © 2009 John Wiley & Sons, Ltd.
Partial least squares regression as a powerful tool for investigating large combinatorial polymer libraries
Authors: Taylor Michael , Urquhart Andrew J. , Anderson Daniel G. , Langer Robert , Davies Martyn C. , Alexander Morgan R.
Published: January 2009

Partial Least Squares (PLS) regression is an established analytical tool in surface science, particularly for relating multivariate ToF‐SIMS data to a univariate surface property. Herein we construct a PLS model using ToF‐SIMS and surface energy data from a 496 copolymer micro‐patterned library. Using this 496 copolymer library we investigate how changing the number of samples used to construct the PLS model affects the identity of the most influential ions identified in the regression vector. The regression coefficients vary in magnitude, but the general relationship between ion structure and surface energy is maintained. As expected, if copolymers containing monomers with unique chemistries are removed from the training set, secondary ions specific to these copolymers are not present in the regression vector. The use of PLS to obtain quantitative predictions has not been actively explored in the surface analytical field. We investigate whether the PLS model obtained can be used to predict the surface energies of polymers within and outside of the training set. The model systematically underestimated the surface energy of a group of acrylate copolymers synthesised using monomers common to the training set, but in different compositions. The predictions for a group of acrylate copolymers that were synthesised from monomers not used in the training set were very poor. When the model was used to obtain predictions for six commercially available polymers the values obtained were all close to the mean surface energy of the training set. This exercise suggests that PLS may be able to predict the surface energy of polymers synthesised from monomers common to the training set, confirming the importance that the training set reflects the chemistry of the samples to be predicted. Copyright © 2008 John Wiley & Sons, Ltd.
Students' levels of explanations, models, and misconceptions in basic quantum chemistry: A phenomenographic study
Authors: Stefani Christina , Tsaparlis Georgios
Published: January 2009

We investigated students' knowledge constructions of basic quantum chemistry concepts, namely atomic orbitals, the Schrödinger equation, molecular orbitals, hybridization, and chemical bonding. Ausubel's theory of meaningful learning provided the theoretical framework and phenomenography the method of analysis. The semi‐structured interview with 19 second‐year chemistry students supplied the data. We identified four levels of explanations in the students' answers. In addition, the scientific knowledge claims reflected three main levels of models. By combining levels of explanations with levels of models, we derived four categories. Two of the categories are shades of variation in the rote‐learning part of a continuum, while the other two categories are in the meaningful‐learning part. All students possessed alternative conceptions some of which occurred within certain categories, while others spanned more categories. The insistence on the deterministic models of the atom, the misinterpretation of models, and the poor understanding of the current quantum concepts are main problems in the learning of the basic quantum chemistry concepts. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 520–536, 2009
Safety of Laparoscopic Appendectomy During Pregnancy
Authors: Kirshtein Boris , Perry Zvi Howard , Avinoach Eliezer , Mizrahi Solly , Lantsberg Leonid
Published: January 2009

Background

Use of laparoscopic appendectomy (LA) remains controversial during pregnancy because data regarding procedure safety are limited. The outcome of LA in pregnant women was evaluated and compared to results of open surgery.

Methods

Between January 1997 and December 2007, 42 pregnant women (mean age 24 years [range: 19–40 years]; range of gestation: 5–25 weeks) underwent appendectomy for suspected acute appendicitis: 23 laparoscopic (LA) and 19 open appendectomies (OA). Retrospective review of medical charts included preoperative information, surgery results, and outcome of the pregnancy.

Results

There was no difference between groups in surgery delay following arrival at the hospital. All procedures, except one case of Meckel’s diverticulitis, were completed laparoscopically without need for conversion. Acute appendicitis was found in 19 cases and Meckel’s diverticulitis in one case during LA (87%) and in 18 cases (95%) during OA. Complicated appendicitis was found in 7 (30%) pregnant women in the LA group and 1 (5%) in the OA group. Five women with normal preoperative abdominal ultrasonography had acute appendicitis (2 in the OA group and 3 in the LA group). The laparoscopic procedure was performed more often by senior surgeons (70% of cases), and OA was more commonly done by residents (47% of cases). There were no intraoperative or postoperative complications recorded. The length of postoperative hospital stay was slightly prolonged after LA—2.4 days versus 1.4 day after OA. There was one fetal loss in each group, 1 and 2 months after the operation.

Conclusions

Laparoscopic appendectomy is safe and effective during pregnancy and is associated with good maternal and fetal outcome.
Microarray Analysis of Somatostatin Receptor 5‐Regulated Gene Expression Profiles in Murine Pancreas
Authors: Patel Sanjeet G. , Zhou Guisheng , Liu Shi‐He , Li Min , Jeong Jae‐Wook , DeMayo Francesco J. , Gingras Marie‐Claude , Gibbs Richard A. , Fisher William E. , Brunicardi F. Charles
Published: January 2009

Background

We previously demonstrated that somatostatin receptor type 5 (SSTR5) gene ablation results in alterations in insulin secretion and glucose metabolism, accompanied by morphologic alterations in the islets of Langerhans. The underlying mechanism(s) by which SSTR5 exerts its cellular functions remain(s) unknown. We hypothesized that SSTR5 mediates the inhibitory effect of somatostatin (SST) on insulin secretion and islet proliferation by regulating a specific set of pancreatic genes.

Methods

To identify SSTR5‐regulated pancreatic genes, gene expression microarray analysis was performed on the whole pancreas of 1‐ and 3‐month‐old wild‐type (WT) andSSTR5knockout (SSTR5−/−) male mice. Real‐time RT‐PCR and immunofluorescence were performed to validate selected differentially expressed genes.

Results

A set of 143 probes were identified to be differentially expressed in the pancreas of 1‐month‐oldSSTR5−/−mice, 72 of which were downregulated and 71 upregulated. At 3 months of age,SSTR5gene ablation resulted in downregulation of a set of 30 probes and upregulation of a set of 37 probes. Among these differentially expressed genes, there were 15 and 5 genes that were upregulated and downregulated, respectively, in mice at both 1 and 3 months of age. Three genes,PAP/INGAP,ANG, andTDE1, were selected to be validated by real‐time RT‐PCR and immunofluorescence.

Conclusions

A specific set of genes linked to a wide range of cellular functions such as islet proliferation, apoptosis, angiogenesis, and tumorigenesis were either upregulated or downregulated inSSTR5‐deficient male mice compared with their expression in wild‐type mice. Therefore, these genes are potentialSSTR5‐regulated genes during normal pancreatic development and functional maintenance.
On polyharmonic maps into spheres in the critical dimension
Authors: Goldstein Paweł , Strzelecki Paweł , Zatorska-Goldstein Anna
Published: January 2009

We prove that every polyharmonic map

u\in W^{m,2}(\mathbb{B}^{n},\mathbb{S}^{N−1})

is smooth in the critical dimension

n = 2m

. Moreover, in every dimension

n

, a weak limit

u\in W^{m,2}(\mathbb{B}^{n},\mathbb{S}^{N−1})

of a sequence of polyharmonic maps

u_{j}\in W^{m,2}(\mathbb{B}^{n},\mathbb{S}^{N−1})

is also polyharmonic.

The proofs are based on the equivalence of the polyharmonic map equations with a system of lower order conservation laws in divergence-like form. The proof of regularity in dimension

2m

uses estimates by Riesz potentials and Sobolev inequalities; it can be generalized to a wide class of nonlinear elliptic systems of order

2m

.
Boundary blow-up solutions of cooperative systems
Authors: Dupaigne Louis , Goubet Olivier , Martínez Salomé , Dávila Juan
Published: January 2009

We study the existence, uniqueness and boundary profile of nonnegative boundary blow-up solution to the cooperative system

\begin{cases}
\mathrm{\Delta }u = g(u−v) & \text{in} & \Omega , \\
\mathrm{\Delta }v = f(v−\beta u) & \text{in} & \Omega , \\
u = v = \infty & \text{on} & \partial \Omega
\end{cases}

in a smooth bounded domain of

\mathbb{R}^{N}

, where

f

,

g

are nondecreasing, nonnegative

C^{1}

functions vanishing in

(−\infty ,0]

and

\beta > 0

is a parameter.
A neurotropic lymphoma in the brachial plexus of a cat
Authors: Linzmann Helge , Brunnberg Leo , Gruber Achim D. , Klopfleisch Robert
Published: January 2009

A 7-year-old, intact male domestic shorthair cat was presented with a progressive, non-weight-bearing lameness of the right forelimb. A neurological examination of the patient at the Small Animal Clinic revealed a paralysis of the radial nerve with sustained cutaneous sensation and a hyperaesthetic response. Further clinical, radiological and pathological findings lead to a diagnosis of a primary, neurotropic B-cell lymphoma in the brachial plexus.
Rage Against the Machines: Explaining Outcomes in Counterinsurgency Wars
Authors: Lyall Jason , Wilson Isaiah
Published: January 2009

During the nineteenth century, states routinely defeated insurgent foes. Over the twentieth century, however, this pattern reversed itself, with states increasingly less likely to defeat insurgents or avoid meeting at least some of their demands. What accounts for this pattern of outcomes in counterinsurgency (COIN) wars? We argue that increasing mechanization within state militaries after World War I is primarily responsible for this shift. Unlike their nineteenth-century predecessors, modern militaries possess force structures that inhibit information collection among local populations. This not only complicates the process of sifting insurgents from noncombatants but increases the difficulty of selectively applying rewards and punishment among the fence-sitting population. Modern militaries may therefore inadvertently fuel, rather than deter, insurgencies. We test this argument with a new data set of 286 insurgencies (1800–2005) and a paired comparison of two U.S. Army divisions in Iraq (2003–2004). We find that higher levels of mechanization, along with external support for insurgents and the counterinsurgent's status as an occupier, are associated with an increased probability of state defeat. By contrast, we find only partial support for conventional power- and regime-based explanations, and no support for the view that rough terrain favors insurgent success.
The Unconditional Most-Favored-Nation Clause and the Maintenance of the Liberal Trade Regime in the Postwar 1870s
Authors: Coutain Bryan
Published: January 2009

International institutions within the past thirty years become the subject of renewed interest as scholars vigorously dispute their utility. Neorealists draw on the post–World War II era to advance sweeping general claims of institutional inefficacy. This study, by contrast, deploys the same hard-test method Grieco applied to the 1970s Tokyo Round negotiations to the crisis-rife 1870s to construct a unique methodological objective: a rigorous hard-test of nineteenth-century institutional autonomy. Three principal findings emerged. First, the maintenance of a liberal world economy in the turbulent 1870s is explained by an unlikely commercial instrument and the unprecedented regime design of an unexplored international institution—respectively the unconditional most-favored-nation (MFN) clause and the informal conventional tariff system (CTS) regime it underpinned—not British hegemony. Second, the international trade regime was not a public good unilaterally provisioned by “hegemonic” Britain via the 1846 Corn Laws Repeal. The regime was instead a private good that was collectively provisioned by all its constituent member states via the unprecedented interstate practices institutionalized in the 1860 Cobden-Chevalier Treaty and then autonomously maintained by a negarchical and self-enforcing sanctioning mechanism. Finally, the informal CTS regime's enforcement mechanism autonomously altered the interests and behaviors of states in directions incongruent with executive preferences solely through the brute force of rational calculations imposed by decentralized international institutional constraints. Both the French and British executives in the 1870s believed the regime was normatively inappropriate and unsuccessfully attempted to exit amid eight system-threatening crises. Nonetheless, the MFN-based regime's self-enforcing sanctioning mechanism autonomously induced compliance: conceptualized as unitary states' behavior deviating from executives' first-order preference. The extraordinarily turbulent 1870s therefore provide an unexplored historical vantage point to make strong institutionalist claims in an era, issue area, and under conditions that they are least likely to be validated.
In the Shadow of War: The Effects of Conflict on Liberal Democracy
Authors: Krebs Ronald R.
Published: January 2009

Events of and since 11 September 2001 have renewed interest in age-old questions about liberal-democratic governance in the shadow of insecurity, crisis, and war. Academic lawyers in particular have engaged in a vigorous debate about how liberal polities can confront security threats while maintaining their commitment to the rule of law. Yet few empirical political scientists, and even fewer scholars of international relations, have weighed in. The short- and especially long-run effects of international conflict on liberal-democratic institutions and processes remain an underexplored aspect of the second-image-reversed. Prompted by recent research in law, this article finds that prominent arguments often rest on shaky theoretical and empirical foundations. It argues that the two most notable traditions of thought on war and democracy are complementary, not competing; that small wars may also have substantial consequences; and that analysts must distinguish clearly among three distinct causal phenomena—threat, mobilization, and warfare—when considering conflict's impact on democracy. The article critically reviews the effects of conflict on both participation and contestation; identifies the salient outstanding questions and suggests hypotheses addressing them; and explores the implications for contemporary normative debates over executive authority and emergency powers.
The ‘Durty Spirit’ at Hertford: A Falling out of Friends
Authors: ADAMS BEVERLY
Published: January 2009

In 1660 the Quaker movement was confronted with a new political situation. In response, the
leadership constructed a centralised system of bureaucracy designed to maintain solidarity in the face
of persecution. Not all Friends, however, reacted positively to the changes, especially the new
arrangements for women's meetings and the conduct of weddings. By the 1670s the movement was
split by the Wilkinson–Story controversy, an internal dispute reflected in Quaker meetings
throughout the country. This article examines the friction between Friends in Hertford and the
claims made by some members of the meeting that George Fox was stifling individual spiritual
freedom, the touchstone of Quaker doctrine.
Responses to Hume on Religion by Anglicans and Dissenters
Authors: RIVERS ISABEL
Published: January 2009

David Hume's attacks on religion posed particular problems of method and approach for those who undertook to reply to them. This article is concerned with the responses of two main groups from the mid-eighteenth century to the early nineteenth: a number of Anglicans and Episcopalians, and a smaller group of rational Dissenters. The responses of some of these are well known, but those of others have not hitherto been investigated. The essay charts a definite shift from wit and ridicule to reasoned and mannerly response as the appropriate way to deal with infidelity. Most respondents assumed that Hume could be adequately refuted by rehearsing old arguments; however, a small but significant number maintained that his infidelity was of positive value for the future of Christianity.
BOOTSTRAPPING SYSTEMS COINTEGRATION TESTS WITH A PRIOR ADJUSTMENT FOR DETERMINISTIC TERMS
Authors: Trenkler Carsten
Published: January 2009

In this paper we analyze bootstrap procedures for systems cointegration tests with a prior adjustment for deterministic terms suggested by Saikkonen et al. (2006,Econometric Theory22, 15–68) and Saikkonen and Lütkepohl (2000,Journal of Time Series Analysis21, 435–456). The asymptotic properties of the bootstrap test procedures are derived, and their small-sample properties are studied. The simulation study also considers the standard asymptotic test versions and the Johansen cointegration test for comparison.
FINITE-SAMPLE MOMENTS OF THE COEFFICIENT OF VARIATION
Authors: Bao Yong
Published: January 2009

We study the finite-sample bias and mean squared error, when properly defined, of the sample coefficient of variation under a general distribution. We employ a Nagar-type expansion and use moments of quadratic forms to derive the results. We find that the approximate bias depends on not only the skewness but also the kurtosis of the distribution, whereas the approximate mean squared error depends on the cumulants up to order 6.
ADDING REGRESSORS TO OBTAIN EFFICIENCY
Authors: Jun Sung Jae , Pinkse Joris
Published: January 2009

It is well known that in standard linear regression models with independent and identically distributed data and homoskedasticity, adding “irrelevant regressors” hurts (asymptotic) efficiency unless such irrelevant regressors are orthogonal to the remaining regressors. But we have found that under (conditional) heteroskedasticity “irrelevant regressors” can always be found such that one can achieve the asymptotic variance of the generalized least squares estimator by adding the “irrelevant regressors” to the model.
Outbreaks ofShigella sonneiinfections in Denmark and Australia linked to consumption of imported raw baby corn
Authors: LEWIS H. C. , ETHELBERG S. , OLSEN K. E. P. , NIELSEN E. M. , LISBY M. , MADSEN S. B. , BOEL J. , STAFFORD R. , KIRK M. , SMITH H. V. , TIKUMRUM S. , WISETROJANA A. , BANGTRAKULNONTH A. , VITHAYARUNGRUANGSRI J. , SIRIARAYAPORN P. , UNGCHUSAK K. , BISHOP J. , MØLBAK K.
Published: January 2009

We investigated an outbreak ofShigella sonneiinfections in Denmark and Australia associated with imported baby corn from one packing shed in Thailand. We reviewed nationwide surveillance and undertook case finding, food trace-back and microbiological investigation of human, food and environmental samples. A recall of baby corn and sugar snaps was based on descriptive epidemiological evidence. In Denmark, we undertook a retrospective cohort study in one workplace. In total, 215 cases were laboratory-confirmed in Denmark, and 12 in Australia. In a multivariable analysis, baby corn was the only independent risk factor. Antibiotic resistance and PFGE outbreak profiles in Denmark and Australia were indistinguishable, linking the outbreaks. Although we did not detectS. sonneiin baby corn, we isolated high levels of other enteric pathogens. We identified a packing shed in Thailand that supplied baby corn to Denmark and Australia, and uncovered unhygienic practices in the supply chain. This outbreak highlights the importance of international communication in linking outbreaks and pinpointing the source.
Enhanced production of Labrador Sea Water in 2008
Authors: Yashayaev Igor , Loder John W.
Published: January 2009

A May 2008 oceanographic survey of the Labrador Sea and recent Argo float profiles have revealed that convective overturning extended to a depth of about 1600 m during the winter of 2008, resulting in the production of a large “year class” of Labrador Sea Water. This convection was the deepest since 1994, and substantially exceeded the convection to 500–1100 m in the past few years in both the Labrador and Irminger Seas. The resultant 0.2°C cooling of the intermediate‐depth waters in the Labrador Sea has disrupted a steady warming of these waters since 1994. The cumulative heat loss from the ocean to the atmosphere during the 2007–2008 cooling season was the largest since the mid‐1990s and exceeded the 2000–2007 mean by about 50%. This indicates that enhanced atmospheric cooling, apparently associated with below‐normal air temperatures in the region, was the predominant factor contributing to the enhanced LSW production in 2008.
Modes of the southern extension of the East Madagascar Current
Authors: Siedler Gerold , Rouault Mathieu , Biastoch Arne , Backeberg Bjorn , Reason Chris J. C. , Lutjeharms Johann R. E.
Published: January 2009

Data sets from satellite observations and a nested high‐resolution model are used to study a source region of the Agulhas Current. Altimeter‐derived geostrophic surface currents are averaged over varying periods, providing evidence of the persistence of flow patterns in the extension of the southern branch of the East Madagascar Current (SEMC). South of Madagascar, the SEMC separates into one branch toward the Agulhas Current and into a second branch retroflecting and connecting to the Subtropical Indian Ocean Countercurrent (SICC). Good agreement is found between long‐term mean patterns of observational and model dynamic heights. Two basic modes are identified in the SEMC extension, with anticyclonic motion favoring retroflection in the northern Mozambique Basin when the extension is in a southwestward direction and cyclonic motion occurring in the case of the SEMC flowing westward along the southern Madagascar slope. A cross‐correlation sequence between model SEMC transports and the modal changes in the extension region displays a correlation at about 1‐month lag which agrees with eddy propagation time from the SEMC to the outflow region. Mean model SEMC transports are determined using floats released at 21°S, and the contribution of the SEMC to the SICC is obtained using floats injected at 55°E with the model running backward. Almost half of the SEMC volume transport contributes to the Agulhas system, and about 40% of SICC water originates from the SEMC.