bluuebunny/crossref_metadata_2025 huggingface dataset:
Additional considerations for gray wolf management after their removal from Endangered Species Act protections
Authors: Way Jonathan G. , Bruskotter Jeremy T.
Published: November 2011

Mech (2010) provided a review of options involving regulated, public hunting of gray wolves (Canis lupus) when states regain control of wolf management. We agree with his general conclusion that the use of lethal management should focus more in areas of conflict and less in wilderness areas, especially near protected places like national parks. Here, we expand on Mech's work and provide additional considerations that could be incorporated into state management plans to make them more acceptable to an increasingly diverse group of interested stakeholders, including: 1) the use of human dimensions research to understand the conditions under which stakeholders find lethal management acceptable, and to evaluate the acceptability of agency efforts to increase tolerance for wolves; 2) employing preventative measures to protect livestock and pets, especially in cases where wolf packs are highly visible to the public; and 3) selective use of sport hunting in areas where wolf impacts are deemed unacceptable. © 2011 The Wildlife Society.
Otologic complications of cotton swab use: One institution's experience
Authors: Smith Matthew , Darrat Ilaaf , Seidman Michael
Published: November 2011

Objectives/Hypothesis:

To evaluate the indications for observation versus surgery in the management of cotton swab‐induced tympanic membrane perforations (TMP).

Study Design:

Institutional review board‐approved retrospective cohort study of 1,540 patients with a diagnosis of TMP from 2001 to 2010. Patients with a cotton swab injury were subdivided into two groups: observation and surgery.

Methods:

Data collection included demographics, symptoms, surgery type, and pre‐ and postintervention audiometry. Successful outcomes were defined as healed TMP; resolution/improvement of vertigo, tinnitus, or facial nerve paralysis; and/or closure of the air‐bone gap (ABG).

Results:

Fifty‐four of 1,540 patients presented with a cotton swab‐induced TMP. Four of the 54 patients (7.4%) underwent delayed surgical repair with 100% success. Preoperatively, one patient had a facial nerve paralysis and two had vertigo with confirmed perilymphatic fistulae (PLF). Postoperatively, the facial nerve paralysis resolved, and one patient had mild vertigo. Fifty of 54 patients opted to forego surgery with 35 patients available for follow‐up. Thirty‐four (97%) of the 35 patients had spontaneous healing. The average time to perforation closure was 1.75 months. Twelve of 35 patients had no ABG after healing.

Conclusions:

Observation is an appropriate consideration for patients who have a TMP due to a cotton swab injury. Surgical intervention should be offered early when a PLF is suspected, or if facial paralysis, severe vertigo, and/or profound sensorineural hearing loss are present. As otolaryngologists, we should be reluctant to offer surgical intervention of an acute injury without significant symptoms as most patients will heal spontaneously within 2 months.
Intravascular papillary endothelial hyperplasia of the internal auditory canal
Authors: Sun Gordon H. , Shoman Nael M. , Theodosopoulos Philip V. , Kendler Ady , Pensak Myles L.
Published: November 2011

Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson's tumor, is a rare vascular lesion characterized by intravascular proliferation of endothelial‐lined papillae and a propensity for manifestation in the head and neck. Signs and symptoms associated with IPEH generally occur due to compressive effects of the lesion on adjacent structures. A rare instance of IPEH occurring in the internal auditory canal is presented herein. Clinical presentation, radiographic and pathologic findings, and management strategies are discussed.
An integrated simulator for endolaryngeal surgery
Authors: Nixon Iain J. , Palmer Frank L. , Ganly Ian , Patel Snehal G.
Published: November 2011

The acquisition and maintenance of skills in transoral microlaryngeal surgery requires extended practice. Effective mentoring of such single‐operator procedures is not possible, making it important for trainee surgeons to acquire basic skills outside of the operating room before participating in procedures on patients. Currently available training simulators use either synthetic materials or human tissue, both of which have limitations. We have designed a hybrid simulator that incorporates a porcine larynx in to an airway training manikin, providing both accurate airway anatomy and natural tissue handling characteristics. This model allows training in the skills required for suspension laryngoscopy and the resection of laryngeal lesions. Further applications could include development of surgical techniques and instruments, and use in accreditation of training and revalidation of trained surgeons.
Estimation of skin removal in aging asian blepharoplasty
Authors: Hsu Amy K , Jen Albert
Published: November 2011

Objectives/Hypothesis:

To describe a novel method for estimating the amount of skin to resect in upper blepharoplasty in the aging Asian eyelid and to report our experience with this technique.

Study Design:

Retrospective review of patients in a single private practice.

Methods:

Resection of skin in upper blepharoplasty in an Asian eyelid can often be less forgiving than in other ethnicities due to the unique anatomy of the supratarsal fold. Excising a maximal amount of excess skin will result in an unfavorable appearance of the upper eyelid in an Asian patient. We applied a technique of pinching the skin while the patient is awake until the patient is satisfied with the appearance. The skin is then measured and the precise amount resected during blepharoplasty. The supratarsal crease is always recreated even in patients who have a preexisting crease. We conducted a retrospective review of 99 consecutive patients who underwent upper blepharoplasty using this technique. All patients were Asian and aged 40 years or older.

Results:

The study group included 99 patients with a mean age of 55.7 years (range, 42–78 years). The mean follow‐up time was 24 months (range, 12–30 months). The amount of desired skin overhang superior to the supratarsal crease varied considerably among patients. Complications included asymmetry in nine patients (9.1%), scarring in three patients (3.0%), and unfavorable cosmetic result in two patients (2.0%). No patients experienced infection, bleeding, or visual changes.

Conclusions:

In upper blepharoplasty in the aging Asian eyelid, it is necessary to resect less skin than in the Caucasian patient to achieve the desired appearance of the upper eyelid complex. Using a patient‐assisted approach to estimate the amount of skin to remove, a favorable cosmetic result with a low incidence of complications was achieved in a consecutive series of patients. Laryngoscope, 2012
Sentinel node biopsy in head and neck desmoplastic melanoma: An analysis of 244 cases
Authors: Smith Valerie A. , Lentsch Eric J.
Published: November 2011

Objectives/Hypothesis:

Desmoplastic melanoma's low rate of sentinel lymph node (SLN) positivity and predilection for the head and neck region have led some to question the role of sentinel lymph node biopsy (SLNB) in patients with this rare histologic variant. Given desmoplastic melanoma's sarcoma‐like histology and aberrant clinical behavior, we hypothesized that SLN status may not be indicative of outcomes in desmoplastic melanoma of the head neck. The objective of this study was to compare melanoma‐specific survival among patients with head and neck desmoplastic melanoma based on SLN status.

Study Design:

Retrospective analysis of patient data and outcomes using the Surveillance Epidemiology and End Results (SEER) database

Methods:

The SEER database was queried for patients who were diagnosed with desmoplastic melanoma and underwent SLNB. Clinicopathologic data and 5‐year disease‐specific survival (DSS) were compared among patients with positive and negative SLNs.

Results:

We identified 244 patients with desmoplastic melanoma of the head and neck who underwent SLNB. Of these, only nine had positive SLNs (3.69%). Among the SLN‐positive patients, five (55.6%) had scalp/neck tumors, three (33.3%) had ulcerated tumors, and tumor thickness ranged from 1.7 to 8.5 mm (mean, 4.8 mm). On univariable and multivariable analysis, SLN positivity did not significantly affect DSS in head and neck desmoplastic melanoma (P = .19 and P = .48, respectively).

Conclusions:

Our findings provide further evidence against routine SLNB in head and neck desmoplastic melanoma by demonstrating a lack of prognostic significance related to the procedure, and by confirming a significantly low rate of SLN positivity as well.
Clinical and pathological characteristics of IgG4‐related sclerosing sialadenitis
Authors: Ohta Nobuo , Kurakami Kazuya , Ishida Akihiro , Furukawa Takatoshi , Saito Fumiaki , Kakehata Seiji , Izuhara Kenji
Published: November 2011

Objectives/Hypothesis:

A new concept of IgG4‐related sclerosing sialadenitis characterized by high serum IgG4 levels and tissue infiltration of IgG4‐expressing plasmacytes has recently been proposed. To determine appropriate serum levels of IgG4 for monitoring disease activity, a total of 36 serum samples and eight tissue samples from patients with IgG4‐related sclerosing sialadenitis were studied.

Study Design:

A retrospective clinical study at Yamagata University School of Medicine.

Methods:

The patient group consisted of six males and four females with an average age of 60 years (range, 47–74 years). Serum levels of IgG4 and the density of IgG4‐positive plasmacytes in affected tissues were studied.

Results:

All patients had elevated serum IgG4 levels (>135 mg/dL), and IgG4‐positive plasmacytes (IgG4+ plasma cells/IgG+ plasma cells >50%) were observed in the involved salivary glands. Six patients with IgG4‐related sclerosing sialadenitis with high IgG4/IgG ratios and prominent infiltration of IgG4‐positive plasmacytes in the involved salivary glands had systemic complications, including pancreatitis, retroperitoneal fibrosis, and/or inflammatory pseudotumor of the lung after swelling of the salivary glands. All six of these patients were successfully treated with systemic corticosteroids.

Conclusions:

In the six patients with systemic complications, treatment with systemic corticosteroids reduced the salivary gland enlargement and lowered serum IgG4 concentrations. These results suggest that IgG4 plays an important role in the pathogenesis of IgG4‐related sclerosing sialadenitis, and that IgG4 levels and IgG4/IgG ratios may be used as additional indicators of disease activity and as biomarkers for potential life‐threatening complications.
Proposed classification system for reporting 532‐nm pulsed potassium titanyl phosphate laser treatment effects on vocal fold lesions
Authors: Mallur Pavan S. , Johns Michael M. , Amin Milan R. , Rosen Clark A.
Published: November 2011

Objectives/Hypothesis

Currently, no standard exists for reporting treatment results for the potassium titanyl phosphate (KTP) laser. The goal of this study was to establish a validated classification schema for reporting immediate tissue effects after laser treatment.

Study Design

Evaluation of KTP laser video sequences by academic laryngologists with use of the rating system.

Methods

A five‐point classification system was developed; this included noncontact angiolysis, epithelial blanching, epithelial disruption, contact epithelial ablation, and contact epithelial ablation with tissue removal. Video recordings were made prospectively for each treatment effect. Ten treatment recordings, with two repeated recordings, were presented to seven academic laryngologists, who were asked to categorize each based on the given classification scheme.

Results

Overall accuracy for the combined reviewers in rating the treatments was 82%. Six of seven reviewers showed perfect intrarater reliability. Accuracy in rating clips did not correlate with the previous number of 532‐nm KTP or 585‐nm pulsed dye laser procedures performed but showed a trend toward correlating with total years in practice. This study reveals that standardized reporting of effects of the KTP laser is feasible.

Conclusions

We believe that results of KTP treatment should be reported using a validated classification system of immediate laser effect, along with specific laser settings. This classification system allows for future systematic evaluation of long‐term treatment results prospectively from single laser treatments.

Level of Evidence

4. Laryngoscope, 124:1170–1175, 2014
Diagnosis and gland‐preserving minimally invasive therapy for wharton's duct stenoses
Authors: Koch Michael , Iro Heinrich , Künzel Julian , Psychogios Georgios , Bozzato Alessandro , Zenk Johannes
Published: November 2011

Objectives/Hypothesis:

The management of stenoses of Wharton's duct has so far been little investigated or systematized. The development of minimally invasive treatment methods, including sialendoscopy, has made preservation of gland function possible.

Study Design:

Retrospective study in a tertiary referral center.

Methods:

A total of 153 stenoses of the submandibular duct were diagnosed and treated in 138 patients. Ultrasound and sialendoscopy were the first‐choice diagnostic measures. A total of 62.7% of the stenoses were located in the distal, 11.1% in the middle segment, and 18.3% in the proximal to posthilar duct. Diffuse stenoses were observed in 7.8% of the cases. Sialendoscopy‐assisted intraductal cortisone administration, interventional sialendoscopy, and transoral ductal surgery were the treatment options. The mean period between treatment and data collection was 52.5 months.

Results:

Fibrotic stenoses were diagnosed in 88.3% and bilateral involvement in 8.6% of the cases. Distal stenoses were treated predominantly by ductal incision (79.2%). Stenoses of the midsubmandibular duct were treated conservatively in 29.4% or with sialendoscopy or ductal incision in 35.3% of cases each. Proximal up to posthilar stenoses could be dilated by interventional sialendoscopy in 82.2%. In 25% of all diffuse stenoses, glandular resection was carried out, representing 2.6% of all stenoses. Glandular function was preserved in 97.8% of cases.

Conclusions:

Stenoses of the submandibular duct can be treated using minimally invasive procedures and with preservation of glandular function with a high success rate. Ductal incision procedures are the most important measure, but sialendoscopy becomes more important the more centrally the stenosis is located.
Hollow Polyaniline and Indomethacin Composite Microspheres for Controlled Indomethacin Release
Authors: Zhang Lijuan , Zhang Zhiming , Kilmartin Paul A. , Travas‐Sejdic Jadranka
Published: November 2011

Composite hollow microspheres consisting of polyaniline (PANI) and indomethacin (IND) are prepared through a self‐assembly process in a mixed methanol/water solutions. Different volume fractions of methanol to water and different aniline concentrations are investigated to obtain the optimal conditions for the formation of PANI/IND composite hollow microspheres. The morphologies of the PANI/IND composites are characterized, showing the inner hollow center of the microspheres. Spectroscopic characterizations reveal that the synthesized materials have many typical features of chemically synthesized PANI and confirm the presence of IND in the composites. A controlled release of IND is achieved by adjusting the pH value of the buffer solution.
Schutzschicht gegen Bakterien
Authors: Menzel Henning
Published: November 2011

Der unterschiedliche Aufbau der Membranen von eukaryontischen Zellen und von Bakterienzellen ist der Angriffspunkt für natürliche antibakterielle Peptide. Synthetische (Co)Polymere nutzen deren Strategie ebenfalls und schützen als Beschichtung medizinische Implantate gegen Bakterien.
Die Entdeckung der Gaschromatographie
Authors: Struppe Hans Georg
Published: November 2011

Drei Artikel von Erika Cremer aus dem Jahr 1951 markieren die Geburtsstunde der Gas chromatographie. Im Folgejahr lösen die Publikationen von Anthony T. James und Archer J. P. Martin über “Gas‐liquid Chromatography” eine lebhafte Entwicklung und schnelle Verbreitung dieser analytischen Methode aus.
Lichtblicke: Neues aus der Photoredoxkatalyse
Authors: Leibeling Markus , Werz Daniel B.
Published: November 2011

Eine Gesellschaft, die auf effiziente und saubere Energieträger setzt, verlangt einen ähnlichen Standard von modernen chemischen Synthesemethoden. Licht bietet dem Chemiker ein unerschöpfliches Potenzial als billige, ungiftige und praktisch endlos verfügbare Energiequelle.
Moleküle unterwegs visualisieren und modellieren
Authors: Dieterich Johannes M. , Mata Ricardo A.
Published: November 2011

Die rasche Entwicklung von mobilen Geräten wie Smartphones und Tablet‐PCs ändert unseren Alltag. Wie nutzen Chemiker die neue tragbare Rechenleistung?
Vergiftung oder Krankheit? Screening mit LC‐MS(n)
Authors: Müller Daniel M. , Rentsch Katharina M.
Published: November 2011

Bei klinisch‐toxikologischen Fragen in Spitälern geht es häufig um Notfälle: Die Ärzte müssen unverzüglich erfahren, ob der Zustand des Patienten auf Drogen oder Medikamente zurückzuführen ist, oder ob sie nach einer anderen Ursache suchen müssen. Schnelle Ergebnisse liefert ein neues LC‐MS(n)‐Verfahren mit automatisierter Probenvorbereitung.
Acesulfam: ein künstlicher Süßstoff als Abwasserindikator
Authors: Buerge Ignaz J. , Poiger Thomas
Published: November 2011

Den Weg des Abwassers durch die Kläranlagen über Oberflächengewässer und Grundwasser ins Trinkwasser zeigt ein Süßstoff an: Acesulfam ist weit verbreitet, wird in Kläranlagen nicht abgebaut, bindet kaum an Boden und Sedimente und ist empfindlich nachweisbar.
Sprengstoffe und Drogen — PTR‐MS in der Spurenanalytik
Authors: Jürschik Simone , Sulzer Philipp , Jordan Alfons , Märk Lukas , Märk Tilmann D.
Published: November 2011

Die Protonen‐Tauschreaktions‐Massenspektrometrie ist in Lebensmittel‐ und Umweltanalytik eine etablierte Spurengasanalysetechnik. Sie weist auch Drogen und Sprengstoffe im ppt‐Bereich nach.
Polymer–TiO2 composite nanorattles via RAFT‐mediated emulsion polymerization
Authors: Nguyen Duc , Such Chris , Hawkett Brian
Published: November 2011

In this work, successful synthesis of polymer nanorattles containing titanium dioxide pigment particles in the centers of air voids is reported. The method used amphiphilic macro‐RAFT copolymers as stabilizers for pigment dispersion and the subsequent encapsulation of the pigment with polymer. The particles were first encapsulated by a water swellable hydrophilic layer, followed by a hard hydrophobic layer. Nanorattles were formed by swelling of hydrophilic polymer layers on the surface of the encapsulated pigment particles in a basic solution at elevated temperature. After swelling, the outer hard polymer shell was crosslinked to improve its strength. Air void sizes of the nanorattles were found to be controlled by swelling time, temperature, and the hydrophilic polymer layer thickness. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Exhaustive and partial alkoxylation of polymethylhydrosiloxane by copper‐catalyzed dehydrocoupling with alcohols: Synthesis, crosslinking behavior, and thermal properties of the products
Authors: Iinuma Ryosuke , Narsi Reddy Poreddy , Hayashi Teruyuki , Tanaka Masato
Published: November 2011

Polymethylhydrosiloxane (PMHS) reacts with aliphatic and aromatic alcohols at room temperature in the presence of [CuH(PPh3)]6 complex catalyst to give poly[(methyl) (alkoxy)siloxane]s in high yields. Reactivity of alcohols decreases in the order of p‐methoxyphenol > p‐cresol > phenol > benzyl alcohol > allyl alcohol > ethanol > isopropanol > tert‐butyl alcohol. Partially p‐cresylated polymers, which still retain unreacted SiH bonds, react further with ethylene glycol or water to form cross‐linked polymers, which, depending on the extent of cross linking, gelate during the cross‐linking process. Propargyl alcohol reacts with PMHS very rapidly to give exhaustively and partially propargyloxylated PMHS. Resulting polymers, upon heating, undergo crosslinking. Partially propargyloxylated polymers display high thermal stability [Td5 (temperature of 5% weight loss) > 500 °C] as compared with starting PMHS (243 °C) and exhaustively propargyloxylated one (414 °C). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and property of novel amino acid‐based polymers by self‐polyaddition of monomers containing both oxetanyl and carboxyl groups
Authors: Kudo Hiroto , Ohshiro Toshiki , Atsumi Hiroyuki , Kamio Ayako , Nishikubo Tadatomi , Murakami Saeko
Published: November 2011

A new synthetic strategy for polymers containing amino acids in the main chain was developed. Monomers N‐oxetanylalanine (N‐Oxe‐Ala‐COOH), N‐oxetanylglutamic acid (N‐Oxe‐Glu‐COOH), and N‐oxetanyllysine (N‐Oxe‐Lys‐COOH) containing both oxetanyl and carboxyl groups were synthesized, and self‐polyaddition and self‐copolyaddition of these monomers afforded the corresponding polymers containing amino acids in the main chain [poly(OxAla), poly(OxLys), poly(OxGlu), poly(OxAla‐co‐OxGlu), poly(OxGlu‐co‐OxLys), and poly(OxAla‐co‐OxLys)] with molecular weight in the range of 920–6620, in satisfactory yields. The physical properties, such as solubility, glass transition temperature, and thermal stability, were consistent with the amount of carboxyl groups at the chain ends. Biodegradability of the polymers was examined by the biochemical oxygen demand method; the decomposition ratios of poly(OxAla) and poly(OxAla‐co‐OxGlu) were about 60%, whereas that of poly(OxGlu) was nearly 100% after 28 days. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Asymmetric anionic polymerizations of 7‐cyano‐7‐alkoxycarbonyl‐1,4‐benzoquinone methides
Authors: Nagai Takeshi , Uno Takahiro , Kubo Masataka , Itoh Takahito
Published: November 2011

Asymmetric anionic polymerizations of 7‐cyano‐7‐alkoxycarbonyl‐1,4‐benzoquinone methides (1) with various alkoxy groups were performed using chiral initiators such as lithium isopropylphenoxide (iPrPhOLi)/(S)‐(–)‐2,2′‐isopropylidene‐bis(4‐phenyl‐2‐oxazoline) ((–)‐PhBox) and lithium isopropylphenoxide (iPrPhOLi)/(–)‐sparteine ((–)‐Sp) to investigate the effect of the alkoxy groups of alkoxycarbonyl substituent in the monomers 1 and chiral ligands of chiral initiators on the control of chiral center in the formation of polymers. Molar optical rotation values of the polymers were significantly dependent upon alkoxy groups, and the polymers with higher molar optical rotation were obtained in monomers with primary alkoxy groups. The asymmetric anionic oligomerizations of the quinone methides having methoxy(1a), ethoxy(1b), and n‐propoxy(1c) groups with chiral initiators were carried out. Both 1‐mers and 2‐mers were isolated and their optical resolutions were performed to determine the extent of stereocontrol. High stereoselectivity was observed at the propagation reaction, but not at the initiation reaction. The effect of the counterion on the control of chiral center in the formation of the polymer was investigated in the asymmetric anionic polymerizations of 1b with iPrPhOM(M = Li, Na, K)/(–)‐Sp and iPrPhOM(M = Li, Na, K)/(–)‐PhBox initiators and discussed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis of a “molecular rope curtain”: Preparation and characterization of a sliding graft copolymer with grafted poly(ethylene glycol) side chains by the “grafting onto” strategy
Authors: Araki Jun , Ohkawa Kousaku , Uchida Yusuke , Murakami Yoshihiko
Published: November 2011

A sliding graft copolymer (SGC) with poly(ethylene glycol) (PEG) side chains was prepared by ester formation between terminal carboxyl groups of oxidized PEG methyl ether with molecular weight of 2000 (mPEG2000‐COOH) and hydroxyl groups of a polyrotaxane consisting of PEG and cyclodextrins (CDs). Formation of the SGC structure was confirmed by 1H NMR, attenuated total reflectance Fourier‐transformed infrared, and gel permeation chromatography. The SGC was soluble in good solvents of PEG and insoluble in poor solvents of PEG. Estimation of the number of grafted mPEG chains suggested a “rope‐curtain” like structure, in which an mPEG chain is connected to each CD ring. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Modulating light‐tunable acid sensitivity of a bioinspired polymer simply by adjusting the position of a single methoxy substituent
Authors: Liu Zhilin , Tang Yufang , Li Nan , Lu Lican , Deng Junjie , Cai Yuanli
Published: November 2011

This article describes a rhodopsin‐inspired photosensitive polymer whose light‐tunable acid sensitivity can be widely modulated simply by adjusting the position of a single methoxy substituent in the aromatic rings of cinnamyl groups. The well‐defined poly(5‐ethyl‐5‐methacryloyloxymethyl‐2‐(p‐methoxystyryl)‐[1,3]dioxane) (PEMpMSD) and poly(5‐ethyl‐5‐methacryloyloxymethyl‐2‐(o‐methoxystyryl)‐[1,3]dioxane) (PEMoMSD) as well as poly(5‐ethyl‐5‐methacryloyloxymethyl‐2‐styryl‐[1,3]dioxane) were synthesized via reversible addition‐fragmentation chain transfer (RAFT) process. The results demonstrated that the para‐methoxy substitution of EMpMSD monomer led to the more shortened initialization period and rapid chain propagation of RAFT process than 5‐ethyl‐5‐methacryloyloxymethyl‐2‐styryl‐[1,3]dioxane monomer under mild visible light radiation at 25 °C. The ortho‐methoxy substitution of PEMoMSD led to high degree of photoinduced Z‐isomerization over 80%. Moreover, the para‐methoxy substitution of PEMpMSD led to the rapid hydrolysis of the cyclic acetal linkages in ambient acid media, while the ortho‐methoxy substitution of PEMoMSD slowed down this hydrolysis. This hydrolysis slowed down on Z‐isomerization particularly in PEMoMSD. These effects widely broadened the tunability of the light‐modulated acid sensitivity. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis of imidazolium‐functionalized ionic polyurethane and formation of CdTe quantum dot–polyurethane nanocomposites
Authors: Li Xue , Ni Xufeng , Liang Zhenhua , Shen Zhiquan
Published: November 2011

A series of positively charged imidazolium‐functionalized ionic polyurethanes (IPUs) were prepared in one‐step polymerization process by polymerization of presynthesized short‐chain imidazolium‐based ionic diol, polyethylene glycols with different molecular weights as long‐chain diols, and toluylene‐2,4‐diisocyanate. The structures of IPUs are confirmed by 1H NMR analysis, and the thermogravimetric analysis measurement indicates that the IPUs have high degradation temperature. Fluorescent nanocrystal–polymer composites CdTe–IPU can be prepared conveniently, by the electrostatic interaction between positively charged IPUs and the negatively charged aqueous CdTe quantum dots (QDs). UV–vis absorption and photoluminescence spectra indicate the photochemical stability and strong fluorescent emission of CdTe–IPU composites. The quantum yields (QYs) of the composites are high and basically restore the QYs of the pure QDs. In addition, the transmission electron microscopy photographs show that the QDs in composites are uniform (about 3 nm in diameter) and monodisperse. The obtained nanocomposites are powder or elastomers with good film building. The casted CdTe–IPU films are transparent under visible light, and the colors of the composites and their films are vivid under a UV lamp. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Chemical safety and hazard investigation board web site—summary
Authors: Cohen Hillary
Published: November 2011

The Chemical Safety Board (CSB) is an independent federal agency charged with investigating serious chemical accidents. CSB strives to be a leader in the online communication of safety information and recommendations. The web site reflects our ongoing commitment to effectively outreach to business people, workers, and communities who share our goal of preventing chemical accidents and saving lives. This summary article outlines the CSB resources that are designed to assist companies prevent accidents. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011
InAs/GaAs quantum dots for THz generation
Authors: Daghestani N. S. , Cataluna M. A. , Berry G. , Ross G. , Rose M. J.
Published: November 2011

We report pulsed terahertz generation from InAs/GaAs quantum‐dot based photoconductive devices. For 800 nm optical excitation, the dots act as recombination centres for carriers generated in the GaAs layers. Using photoreflective pump‐probe measurements we demonstrate that the photogenerated carrier lifetime decreases when a lateral bias is applied. This can be attributed to an increase in the capture area of the dots when under bias.

Two types of antenna metallization were investigated; non‐Ohmic, and quasi‐Ohmic contacts. Non‐Ohmic antennae displayed resilience to Joule heating when operated at a field strength of 46 MV/m. The breakdown field of the devices was 48 MV/m, which is comparable to the breakdown field of bulk GaAs (∼50 MV/m). The maximum estimated infrared‐to‐THz conversion efficiency is ∼1x10‐5. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Room temperature photoluminescence intensity enhancement in GaAs1‐xBix alloys
Authors: Mohmad A. R. , Bastiman F. , Ng J. S. , Sweeney S. J. , David J. P. R.
Published: November 2011

The optical properties of GaAs1‐xBix alloys with Bi compositions between 0.022 and 0.06 have been studied by photoluminescence (PL). The samples were grown at 400 °C using molecular beam epitaxy. At room temperature, the incorporation of Bi in GaAs reduces the band gap by 64 meV/%Bi with peak wavelength of 1.2 µm for x = 0.06. It was found that room temperature PL intensity increased with Bi composition, but decreases with composition at 10 K. The results at 10 K suggest that the incorporation of Bi degrades the crystal quality. However, the effect is negated by more efficient carrier confinement as a result of larger band gap offset between GaAs1‐xBix and GaAs at room temperature. Hence, the room temperature PL intensity continues to increase monotonically for x up to 0.06. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photomodulation reflectance study of temperature dependence of the band gap of ZnSe1‐xOx
Authors: Chen Wen‐Yen , Lai Chi‐Wen , Cheng Chao‐Chia , Chen Cheng‐Yu , Chyi Jen‐Inn , Hsu Tzu‐Min
Published: November 2011

We investigated the band gap of ZnSe1‐xOx alloys (x =2.7% and 5.3%) by photomodulation reflectance spectroscopy from 10 K to 300 K. The temperature dependence of band gap of ZnSe1‐xOx exhibited slight deviation from the expectation of the band anticrossing model. The deviation was explained by the decrease of the anticrossing interaction between the oxygen states and conduction band at low temperature. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Trade‐offs between performance and reliability in AlGaN/GaN transistors
Authors: Waltereit Patrick , Bronner Wolfgang , Kiefer Rudolf , Quay Rüdiger , Dammmann Michael , Cäsar Markus , Brückner Peter , Müller Stefan , Mikulla Michael , Ambacher Oliver
Published: November 2011

We report on the trade‐off between performance and reliability for AlGaN/GaN transistors. It is shown that changes in epitaxial growth, transistor design and process may lead to an improvement in performance but are, at the same time, accompanied by a degradation of device reliability. As a result we show strategies in order to balance performance and reliability as both are linked. Based on these findings we have realized state‐of‐the‐art power bars for mobile communication systems and X‐band MMICs for radar applications. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
GaSb‐based semiconductor saturable absorber mirrors for mode‐locking 2 µm semiconductor disk lasers
Authors: Paajaste Jonna , Suomalainen Soile , Koskinen Riku , Härkönen Antti , Steinmeyer Günter , Guina Mircea
Published: November 2011

GaAs‐ and InP‐based Semiconductor saturable absorber mirrors (SESAMs) operating at around 1 μm and 1.55 μm wavelength domains are well understood reliable components used in a large variety of ultrafast lasers. Recently, we demonstrated the first 2 µm GaSb based saturable absorber mirrors used for pico‐ and femtosecond pulse generation in a mode‐locked semiconductor disk laser. Here we report on the fabrication and characterization of similar type of GaSb‐based SESAMs with an in‐depth focus on the growth parameters and their impact on the dynamic properties of the SESAMs. In particular the effects of quantum well growth temperature and strain on absorption recovery time were investigated by pump probe measurements. The results reveal fast absorption recovery times for SESAMs grown under typical growth conditions used to fabricate high quality quantum‐well laser structures. The absorption recovery exhibited a double exponential decay characteristic with a fast component having a characteristic time of about 0.5 ps and a slow component of about 10 ps. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of the cone angle and crystal shape on the formation of twins in InP crystals
Authors: Li Xiaolan , Yang Ruixia , Yang Fan , Sun Tongnian , Sun Niefeng
Published: November 2011

We present the investigation of twinning phenomena of LEC InP crystal growth which has been carried out in our laboratory in recent years. It is observed that the yield of twin‐free single crystal InP can be grown by control the cone angle and crystal shape of a gradually increased diameter. Twin formation has been correlated to many growth factors. The influence of ingot shape on the formation of twins can be looked as the conical angle dependent twin probability of InP crystals. Twin‐free InP crystals can be grown by large cone angle over 75° to 90°. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase‐controlled epitaxial growth of iron oxide thin films on MgO(001) and LaAlO3(001) substrates
Authors: Wang Zhiguang , Viswan Ravindranath , Hu Bolin , Harris V. G. , Li Jie‐Fang , Viehland D.
Published: November 2011

We have deposited epitaxial iron oxide thin films on MgO(001) and LaAlO3(LAO)(001) substrates, resulting in different phase stabilities. Atomic force microscopy images revealed a smooth surface. Detailed X‐ray diffraction (XRD) measurements were performed to confirm the epitaxial growth and to analyze the atomic growth configuration. We found that (00l) oriented γ‐Fe2O3 was the stable phase on MgO(001) substrates, whereas $ (1\bar 102) $ oriented α‐Fe2O3 was stable on LAO(001). Magnetic hysteresis loop measurements revealed typical ferrimagnetic behavior for γ‐Fe2O3 on MgO, whereas the magnetization of α‐Fe2O3 on LAO was relatively small and consistent with an antiferromagnetic order. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tracking and prediction of large‐scale organized tropical convection by spectrally focused two‐step space–time EOF analysis
Authors: Roundy Paul E.
Published: November 2011

An empirical orthogonal function (EOF) analysis in time and space is applied to extract the coherent signals of convectively coupled equatorial waves, intraseasonal oscillations, and other disturbances from unfiltered satellite outgoing long‐wave radiation anomaly data. The algorithm produces a basis of time indices for the coherent signals in selected bands of the zonal wave‐number frequency domain and also generates reduced noise versions of wave‐number frequency filtered data applicable in real time. Multiple linear regression is applied to forecast the time indices of each wave‐number frequency band, and the predicted indices are applied to reconstruct the predicted filtered outgoing long‐wave radiation (OLR) fields. A cross‐validation analysis demonstrates that the predicted Madden–Julian oscillation (MJO) signals exhibit skill to 25 days across the global Tropics, and beyond 30 days across some of the higher latitudes of the Tropics. Copyright © 2011 Royal Meteorological Society
Advances in data stream mining
Authors: Gaber Mohamed Medhat
Published: November 2011

Mining data streams has been a focal point of research interest over the past decade. Hardware and software advances have contributed to the significance of this area of research by introducing faster than ever data generation. This rapidly generated data has been termed as data streams. Credit card transactions, Google searches, phone calls in a city, and many others\are typical data streams. In many important applications, it is inevitable to analyze this streaming data in real time. Traditional data mining techniques have fallen short in addressing the needs of data stream mining. Randomization, approximation, and adaptation have been used extensively in developing new techniques or adopting exiting ones to enable them to operate in a streaming environment. This paper reviews key milestones and state of the art in the data stream mining area. Future insights are also be presented. © 2011 Wiley Periodicals, Inc.

This article is categorized under:

Algorithmic Development > Spatial and Temporal Data Mining
The box C/D and H/ACA snoRNPs: key players in the modification, processing and the dynamic folding of ribosomal RNA
Authors: Watkins Nicholas J. , Bohnsack Markus T.
Published: November 2011

Box C/D and H/ACA RNPs are essential ribonucleoprotein particles that are found throughout both eukaryotes [small nucleolar RNPs (snoRNPs)] and archaea [snoRNP‐like complexes (sRNPs)]. These complexes catalyze the site‐specific pseudouridylation and most of the methylation of ribosomal RNA (rRNA). The numerous modifications, which are clustered in functionally important regions of the rRNA, are important for rRNA folding and ribosome function. The RNA component of the complexes [small nucleolar RNA (snoRNA) or small RNA (sRNA)] functions in substrate binding by base pairing with the target site and as a scaffold coordinating the organization of the complex. In eukaryotes, a subset of snoRNPs do not catalyze modification but, through base pairing to the rRNA or flanking precursor sequences, direct pre‐rRNA folding and are essential for rRNA processing. In the last few years there have been significant advances in our understanding of the structure of archaeal sRNPs. High resolution structures of the archaeal C/D and H/ACA sRNPs have not only provided a detailed understanding of the molecular architecture of these complexes but also produced key insights into substrate binding and product release. In both cases, this is mediated by significant movement in the complexes. Advances have also been made in our knowledge of snoRNP recruitment and release from pre‐ribosome complexes in eukaryotes. New snoRNA–rRNA interactions have been documented, and the roles of RNA helicases in releasing snoRNP complexes from the rRNA have been described. WIREs RNA 2012, 3:397–414. doi: 10.1002/wrna.117

This article is categorized under:

RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes

Translation > Ribosome Biogenesis

RNA Processing > rRNA Processing
Relative importance of quantity, quality and isolation of patches for butterfly diversity in fragmented urban forests
Authors: Soga Masashi , Koike Shinsuke
Published: November 2011

The majority of forests in urban areas are small and isolated. Improving habitat quality of small forests instead of increasing habitat size and connectivity could be an effective means of conserving the biodiversity of such highly fragmented landscapes. In this study, we investigated the relative importance of habitat quantity, quality and isolation on butterfly assemblages in urban fragmented forests in Tokyo, Japan. We used four habitat geographic parameters: (1) fragment size, (2) shape index, (3) isolation (distance to the mainland), and (4) connectivity; and three habitat quality parameters: (1) herbaceous nectar plant abundance, (2) herbaceous nectar plant diversity, and (3) larval host plant diversity. We surveyed butterfly assemblages along transects in 20 forest fragments that ranged in size from 1 to 122 ha. We used generalized linear models to relate the number of species in a fragment to four habitat geographic parameters and three habitat quality parameters. The averaged models based on AICcshowed that fragment size had a strong positive effect on butterfly species richness. There was also a positive effect of herbaceous nectar plant abundance on species diversity. These findings suggest that improving the habitat quality of small and isolated forests in highly fragmented landscapes may be capable of maintaining levels of butterfly diversity comparable to those of large fragments.
Diversity and decomposition potential of endophytes in leaves of a Cinnamomum camphora plantation in China
Authors: He Xingbing , Han Guomin , Lin Yonghui , Tian Xingjun , Xiang Changguo , Tian Qijian , Wang Fangyuan , He Zaihua
Published: November 2011

This study was carried out to improve our understanding of the diversity and decomposition potential of endophytes in the leaves of Cinnamomum camphora trees grown in a subtropical region of China. We isolated and identified endophytic fungi from senescent leaves of C. camphora and tested their role in decomposition through pure‐culture and pre‐colonization. A total of 2,861 endophytic fungi isolated from 69 leaves of C. camphora were grouped into 39 taxa comprising 36 Ascomycetes and 3 Basidiomycetes based on sporulation and ITS sequence analysis. Of these, Colletotrichum gloeosporioides was the most common species (69% relative abundance and 96% colonization frequency), followed by Cladosporium sp.1, Colletotrichum sp. and Chaetomium sp. All 39 endophytes had the ability to decompose C. camphora leaf litter in pure culture, and a few exhibited >20% litter mass loss in 2 months. In most cases, single endopyhytic species showed lower mass loss than mixed microbial groups from active soil after 60 or 120 days. In pre‐inoculation, endophytic fungi like Chaetomium sp., Cladosporium sp.1, C. gloeosporioides, Colletotrichum sp. and Guignardia sp. exhibited higher abundance and caused greater mass loss, indicating the potential of these groups to enter and significantly accelerate the process of decomposition. This study concludes that, after entering the decomposition process, selected endophytic fungi with high abundance could influence significantly the decomposition process and thus probably affect carbon and nutrient cycling in C. camphora plantations.
On (Not) Closing the Gaps: The Evolution of National and Regional Unemployment Rates by Race and Ethnicity
Authors: Freeman Donald G.
Published: November 2011

This paper conducts stationarity tests for levels and ratios of national and regional unemployment rates by race and ethnicity. Results indicate that both unemployment rates and ratios for the total population and for subgroups by race, ethnicity and region are stationary around changing means. The black/white unemployment ratio has increased on average and the Hispanic/white unemployment ratio has decreased on average. Results are compared across regions of the US.
Afghanistan: The ‘failed State’ as Status Quo?
Authors: Del Pino Teresa de los Reyes Vázquez
Published: November 2011

Since the breakdown of the bipolar system, there has been a renewed interest in so-called failed states. Initially, this interest could be attributed to a post–Cold War enthusiasm for addressing outstanding issues hitherto blocked by the stand-off between superpowers. After 9/11, the focus shifted to failed states that could potentially harbour a new type of asymmetric threat that has proliferated in the form of insurgencies and terrorism. Afghanistan is an example of such a failed state. Ten years after 9/11 and the start of the conflict on its territory, the security and political situation in Afghanistan remains unstable and the Islamist insurgency continues to represent the principal threat. The 10th anniversary of 9/11 presents an appropriate moment to review the reasons why Afghanistan is considered to be a failed state, the challenges faced by the international community and the Afghan authorities in the short to medium term and, more importantly, the issues that should be addressed if Afghanistan is to shed its label as a ‘failed state’.
Brown representability often fails for homotopy categories of complexes
Authors: Modoi George Ciprian , Šťovíček Jan
Published: November 2011

We show that for the homotopy categoryK(Ab) of complexes of abelian groups, both Brown representability and Brown representability for the dual fail. We also provide an example of a localizing subcategory ofK(Ab) for which the inclusion intoK(Ab) does not have a right adjoint.
Flowing resistance and dilatancy of dense suspensions: lubrication and repulsion
Authors: Rognon Pierre Grégoire , Einav Itai , Gay Cyprien
Published: November 2011

The purpose of this study is to provide generic insights into the rheology of immersed particulate materials in dense configurations. We focus on a non-Brownian and Stokesian suspension of elastic spheres, as a way to identify the effect on the collective behaviour of two short-range interactions: lubrication and steric repulsion below a tunable range. The response of the material to shear under a prescribed shear rate and a prescribed normal stress is simulated using ‘soft dynamics’, a discrete element method which accounts for the dynamics of such a system. The material exhibits a visco-elastic behaviour, deforming elastically at high shear rates, and viscously at slower shear rates. When steady flow is established, the constitutive law can be expressed, as for dry grains, through a friction law and a dilatancy law, whose numerical constants depend in a non-trivial manner on the equilibrium gap. The analysis of the contribution of each interacting pair as a function of its distance and orientation sheds some light on this collective behaviour. Lubrication, which hinders grain approach, is responsible for a loss of contact and a low repulsion contribution to the stress. In contrast, lubrication viscously connects each grain to as many as 10 neighbours, which all contribute significantly to the shear stress. This forms a robust dynamic connected network controlling the collective resistance to flow. This study should be useful for modelling the rheological behaviour of real materials such as foams, emulsions and blood: beside the specific properties of their particles, these particulate fluids also involve lubrication and repulsion.
Numerical computation of solitary waves in a two-layer fluid
Authors: Woolfenden H. C. , Pǎrǎu E. I.
Published: November 2011

We consider steady two-dimensional flow in a two-layer fluid under the effects of gravity and surface tension. The upper fluid is bounded above by a free surface and the lower fluid is bounded below by a rigid bottom. We assume the fluids to be inviscid and the flow to be irrotational in each layer. Solitary wave solutions are found to the fully nonlinear problem using a boundary integral method based on the Cauchy integral formula. The behaviour of the solitary waves on the interface and free surface is determined by the density ratio of the two fluids, the fluid depth ratio, the Froude number and the Bond numbers. The dispersion relation obtained for the linearized equations demonstrates the presence of two modes: a ‘slow’ mode and a ‘fast’ mode. When a sufficiently strong surface tension is present only on the free surface, there is a region, or ‘gap’, between the two modes where no linear periodic waves are found. In-phase and out-of-phase solitary waves are computed in this spectral gap. Damped oscillations appear in the tails of the solitary waves when the value of the free-surface Bond number is either sufficiently small or large. The out-of-phase waves broaden as the Froude number tends towards a critical value. When surface tension is present on both surfaces, out-of-phase solitary waves are computed. Damped oscillations occur in the tails of the waves when the interfacial Bond number is sufficiently small. Oppositely oriented solitary waves are shown to coexist for identical parameter values.