bluuebunny/crossref_metadata_2025 huggingface dataset:
Segregation of Cd2 Pairs in CaCu9Cd2 and EuCu9Cd2
Authors: Tappe Frank , Schwickert Christian , Pöttgen Rainer
Published: April 2012

The copper‐rich intermetallics CaCu9Cd2 and EuCu9Cd2 were synthesized from the elements in sealed tantalum tubes in a high‐frequency furnace. Both compounds were characterized by X‐ray powder and single crystal diffraction: Ce(Mn0.55Ni0.45)11 type, P4/mbm, a = 844.2(1), c = 504.72(8) pm, wR2 = 0.0216, 345 F2 values, 23 variables for CaCu9Cd2 and a = 844.1(2), c = 505.5(1) pm, wR2 = 0.0200, 331 F2 values, 24 variables for EuCu9.14Cd1.86. The europium‐based crystal showed a small mixed Cu/Cd occupancy on the 4g site. The calcium (europium) atoms have the high coordination number 20 (16Cu + 4Cd). These polyhedra are condensed via common Cu4 squares along the c axis. Other striking structural motifs are segregated Cd2 pairs (291 pm in CaCu9Cd2) in copper coordination and slightly distorted Cu2@Cu8Cd4 icosahedra. The latter are connected via common Cd2 pairs along c and form the motif of tetragonal rod packing. EuCu9Cd2 shows paramagnetic behavior above 100 K with an experimental magnetic moment of 7.82(1) μB/Eu atom, indicating purely divalent europium.
Feasibility of Emergency Laparoscopic Colectomy for Children with Acute Colonic Perforations and Fibropurulent Peritonitis
Authors: Chang Yu‐Tang , Lee Jui‐Ying , Chiu Chi‐Shu , Wang Jaw‐Yuan
Published: April 2012

Background

Several studies have demonstrated that laparoscopic surgery is safe and effective for urgent and emergent colectomy in adulthood. The aim of the present study was to evaluate the feasibility of laparoscopic colectomy for children in emergent settings.

Methods

Between March 2008 and August 2011, 10 consecutive children with acute colonic perforations and fibropurulent peritonitis secondary to infectious colitis underwent emergency laparoscopic colectomy. Simultaneously, we reviewed and recorded the same data from another consecutive 10 patients who underwent standard laparotomy between November 2004 and February 2008. The two groups were compared with regard to operative time, length of hospital stay (LOS), and complications.

Results

The gender, age, body weight, serum C‐reactive protein, number of involved bowel segments, operative time, and LOS were not significantly different (P = 0.36, 0.50, 0.33, 0.62, 0.81, 0.14 and 0.23, respectively). In the laparoscopy group, one patient required conversion to open surgery because of extensive bowel involvement, and another patient with solitary colonic perforation required reoperation for anastomostic leakage. However, patients who underwent laparotomy had a higher incidence of later complications, including wound infection, incisional hernia, and adhesion ileus (P = 0.03, 0.06, and 0.03, respectively) and thus required more additional unplanned operations (P = 0.05).

Conclusions

Emergency laparoscopic surgery is technically feasible in most children with acute colonic perforations and fibropurulent peritonitis. However, extensive intestinal involvement with multiple perforations should be an indication for converting to open surgery.
New Directions in Capacity Building: Incorporating Cultural Competence into the Interactive Systems Framework
Authors: Gregory Henry , Van Orden Onna , Jordan Lisa , Portnoy Galina A. , Welsh Elena , Betkowski Jennifer , Charles Jade Wolfman , DiClemente Carlo C.
Published: April 2012

The UMBC Psychology Department's Center for Community Collaboration (CCC) provides training and support for capacity building to promote substance abuse and mental health treatment as well as adherence improvement in community agencies funded through the Ryan White Act serving persons living with HIV/AIDS. This article describes an approach to dissemination of Evidence Based Practices (EBPs) for these services that uses the Interactive Systems Framework (ISF) and incorporates a collaborative process involving trainer cultural competence, along with a comprehensive assessment of organizational needs, culture, and climate that culminates in tailored training and ongoing collaboration. This article provides: (1) an overview of the CCC's expanded ISF for the effective dissemination of two EBPs—motivational interviewing and the stages of change perspective; (2) an examination of the role of trainer cultural competence within the ISF framework, particularly attending to organizational culture and climate; and (3) case examples to demonstrate this approach for both general and innovation‐specific capacity building in two community based organizations.

Special Issue: Advances in Bridging Research and Practice Using the Interactive System Framework for Dissemination and Implementation; Guest Editors: Abraham Wandersman, Paul Flaspohler, Catherine A. Lesesne, Richard Puddy; Action Editor: Emilie Phillips Smith
Using repertory grids to explore musical skills and attitudes in a mature-age adult at the early stages of learning for self-fulfilment: A case study of James
Authors: Taylor Angela
Published: April 2012

Repertory grids were used as a research tool to explore 73-year-old James’ musical development over two years. Choosing two music learning cultures for his instrumental learning, James learned the piano in a college workshop and the Appalachian dulcimer in his local folk group. There were clear changes in his musical skills and attitudes, particularly in relation to performing and practising, and an increase in his musical maturity as he transformed himself from a music listener into a musical performer, reconstructing himself as an amateur musician. The empowerment gained from his reconstruction was a critical factor in James’ self-fulfilment as a mature-age adult.
From singular to over-crowded region: Curriculum change in senior secondary school music in New Zealand
Authors: McPhail Graham
Published: April 2012

This paper discusses recent developments in the senior music curriculum in New Zealand. I suggest that school music is in transition from its clearly defined origins to its ‘regionalisation’ by new content and knowledge. The concepts of knowledge differentiation and verticality are considered in relation to the subject's now diverse range of curriculum segments, and I argue that the varied progression requirements of these segments combined with an ‘emptying out’ of significant aspects of knowledge within an outcomes-based curriculum presents significant challenges for curriculum construction and pedagogy. Also vying for space within the curriculum are elements of informal music learning. These challenges need to be carefully considered in light of recent social realist critiques which highlight the significance of the relationship between knowledge structures, curriculum, pedagogy and student access to powerful knowledge.
Very low food security predicts obesity predominantly in California Hispanic men and women
Authors: Leung Cindy W , Williams David R , Villamor Eduardo
Published: April 2012

Objective

A high prevalence of food insecurity has persisted in the USA for the past two decades. Previous studies suggest that the association between food insecurity and obesity may vary by gender and race/ethnicity. We examined whether food insecurity was associated with BMI and obesity within gender and racial/ethnic groups in a large, diverse sample of low-income adults.

Design

A cross-sectional analysis of a large population-based health survey. We compared the distribution of BMI and obesity by food security levels within gender and racial/ethnic categories.

Setting

Data were derived from the 2003–2009 waves of the California Health Interview Survey.

Subjects

The study sample included 35 747 non-elderly adults with households ≤200 % of the federal poverty level.

Results

Among Hispanic men, very low food security was associated with a 1·0 kg/m2 higher BMI (95 % CI 0·3, 1·7 kg/m2) and a 36 % higher prevalence of obesity (95 % CI 17, 58 %) after multivariate adjustment. Among Hispanic women, very low food security was associated with a 1·1 kg/m2 higher BMI (95 % CI 0·4, 1·9 kg/m2) and a 22 % higher prevalence of obesity (95 % CI 8, 38 %). Positive associations were also observed for Asian women and multi-racial men. No significant associations were observed for non-Hispanic whites, African Americans, Asian men or multi-racial women.

Conclusions

Our results suggest that the association of food insecurity and obesity is limited to individuals of certain low-income, minority racial/ethnic groups. Whether targeted interventions to address food insecurity in these individuals may also decrease obesity risk deserves further investigation.
Aetiological factors behind adipose tissue inflammation: an unexplored research area
Authors: von Scholten Bernt J , Andresen Erik N , Sørensen Thorkild IA , Jess Tine
Published: April 2012

Objective

Despite extensive research into the biological mechanisms behind obesity-related inflammation, knowledge of environmental and genetic factors triggering such mechanisms is limited. In the present narrative review we present potential determinants of adipose tissue inflammation and suggest ways ahead for future research in the field.

Design

We searched the literature for potential determinants of obesity with inflammation through MEDLINE by applying the MeSH headings ‘obesity’ and ‘inflammation’ in combination with specific terms for a series of environmental and genetic factors.

Results

Numerous articles reported on the association between environmental or genetic factors and respectively obesity and inflammation, whereas only a few studies assessed obesity and inflammation as a combined outcome. Among suggested determinants for obesity with inflammation were Adenovirus-36, the gut microbiota,trans-fatty acids, and the four genesFTO,MC4R,TNF-αandLEPR.

Conclusions

We present a limited number of factors potentially contributing to the development of obesity with inflammation, while concluding that overall the area is indeed sparsely investigated. We present ideas for future studies that can identify relevant aetiological factors. This identification is essential for targeted prevention of obesity with inflammation and the clinical consequences thereof.
Purity and decomposition theorems for staggered sheaves
Authors: Achar Pramod N. , Treumann David
Published: April 2012

Two major results in the theory of ℓ-adic mixed constructible sheaves are the purity theorem (every simple perverse sheaf is pure) and the decomposition theorem (every pure object in the derived category is a direct sum of shifts of simple perverse sheaves). In this paper, we prove analogues of these results for coherent sheaves. Specifically, we work with staggered sheaves, which form the heart of a certain t-structure on the derived category of equivariant coherent sheaves. We prove, under some reasonable hypotheses, that every simple staggered sheaf is pure, and that every pure complex of coherent sheaves is a direct sum of shifts of simple staggered sheaves.
Organization of the magnetosphere during substorms
Authors: Živković T. , Rypdal K.
Published: April 2012

The change in degree of organization of the magnetosphere during substorms is investigated by analyzing various geomagnetic indices, as well as interplanetary magnetic field z‐component and solar wind velocity x‐component. We conclude that the magnetosphere self‐organizes globally during substorms, but neither the magnetosphere nor the solar wind become more predictable in the course of a substorm. This conclusion is based on analysis of substorms in the period from 2000 to 2002. A minimal dynamic‐stochastic model of the driven magnetosphere that reproduces many statistical features of substorm indices is discussed.
Carbon dioxide dynamics in Kelud volcanic lake
Authors: Caudron C. , Mazot A. , Bernard A.
Published: April 2012

In November 2007, the extrusion of a new lava dome evaporated Kelud volcanic lake in Java, Indonesia. Four months before a detailed echo sounding survey of the volcanic lake coupled to floating accumulation chamber measurements detected abnormally high carbon dioxide emissions. It constituted the earliest sign of the volcanic unrest; well before any other monitored parameter. CO2 flux is quantified using an empirical equation based on the volume of bubbles backscattered in the water column. Its comparison with the fluxes retrieved from the floating chamber method better constrain carbon dioxide dynamics in the volcanic lake. It reveals that 70% of the carbon dioxide enters the lake in a dissolved form, while the remaining 30% is supplied to the lake on a gaseous state. Almost three‐quarter of the ascending bubbles dissolve in the water column leaving the majority of the 330 Tons day−1 of carbon dioxide diffusing at the air‐water interface.
An observational study of aerosol and turbulence properties during dust storms in northwest China
Authors: Fu Peijian , Zhong Shiyuan , Huang Jianping , Song Guangning
Published: April 2012

Since late 2003, measurements of aerosol properties and meteorology have been made at three sites, Minqin, Jiuquan and Dunhuang, in the border areas of the Gobi and Taklimakan Deserts in the northwest of China as part of an observational program for Asian Dust Storms (ADS). The aerosol observations include mass concentration and optical depth, and the meteorological observations include both mean and turbulent quantities. The data from a three‐year period (2004–2007) have been analyzed to characterize aerosol and meteorological conditions during dust storms. The results show that during ADS the aerosol mass concentration (PM10) can reach above 7∼8 mg m−3, 10∼100 times of that on clear days, and the scatter coefficient of fine particles (PM2.5) is 2000∼2500 10−6 m−1, 20∼25 times of the clear day values. There is a dramatic reduction in the visibility during dust storms with average visibility about 2 km, which is only 1/20∼1/30 of that on clear days. The aerodynamic roughness is 0.018 and 0.046 m for the Taklimakan and Gobi Deserts respectively, and the friction velocity is about 0.71 and 0.56 m s−1 during ADS periods, doubling the value found on quiescent days. Turbulence in the lower atmosphere is more intense during ADS period due mainly to increased vertical wind shear associated with strong winds. The large‐scale circulation patterns show that during the ADS conditions the Gobi Desert is typically in the path of cold air from high latitudes moving toward the south or southeast and the data suggest that there is a declining trend for dust storms during the past 5 decades.
An emerging protagonist: Sodium Glucose Co-transporters (SGLTs) as a burgeoning target for the treatment of diabetes mellitus
Authors: Ahmed Danish , Sharma Manju , Kumar Vikas , Yadav Pankaj S
Published: April 2012

Contemporary therapies to rationalize the hyperglycaemia in type 2 diabetes mellitus (T2DM) generally involve insulin-dependent mechanisms and lose their effectiveness as pancreatic b-cell function decreases to a greater extent. The kidney emerges out as a novel and potential target to trim down the T2DM. The filtered glucose is reabsorbed principally through the sodium glucose co-transporter-2 (SGLT2), a low affinity transport system, which is present at the luminal surface cells that cover the first segment of proximal tubules. Competitive inhibition of SGLT2 therefore represents an innovative therapeutic strategy for the treatment of hyperglycaemia and/or obesity in patients with type 1 or type 2 diabetes by enhancing glucose and energy loss through the urine. Selective inhibitors of SGLT2 reduce glucose reabsorption, causing excess glucose to be eliminated in the urine; this decreases plasma glucose. SGLT2 inhibitors are coupled with osmotic dieresis and loss of weight which aid in reducing blood pressure. The observation that individuals with familial renal glycosuria maintain normal long-term kidney function provides some encouragement that this mode of action will not adversely affect renal function. This novel mechanism of targeting the kidney for the treatment of T2DM is reasonably valuable and is independent of insulin and clutch with the low risk of hypoglycemia.
Mummification in a Bitch: A case report
Authors: P Perumal , B Venkateswaralu , Mohanty D.N. , Das Srinibas , Barik Ashok Kumar , Mishra P.C.
Published: April 2012

A pug aged 5 years was admitted in the Lyka pet clinic with difficulty in parturition. Breeding history of the dog was collected from the owner. X-ray was conducted which confirmed the presence of foetus. The bitch was manually handled to relieve the Dystocia following intravenous drip of N.S.S. and oxytocin. In the vent of unsuccessful attempt the bitch was surgically operated for C.S. and six fetuses of which four normal and two mummified were relieved. Routine post operative care were undertaken and the bitch recovered normally with out any complication. Photographic recording was also made during the recovery of mummified foetus.
Role of intellectual property rights in biotechnology and pharmaceutical industries
Authors: Ajeet Ajeet
Published: April 2012

The main objective of this review is to highlight and explore the inter-relationship and the functioning of the intellectual property right in the pharmaceutical and biotechnology industry. The rising tide of patent applications can be witnessed globally in this industry as the need for such protection and licensing has become imperative so as to safeguard the rights of the inventor and also to encourage and promote new talents, inventions and innovations which can be a boon for the economy. The field of biotechnology is an upcoming science which is still at the initial stage of establishing a foundation but it promises a revolution in the fields of medicine, agriculture, pharmaceuticals and industrial sector amongst other sectors of the economy along with contribution to the GDP growth.
Estimation of extracellular lipase enzyme produced by thermophilic bacillus sp. isolated from arid and semi-arid region of Rajasthan, India
Authors: Gaur Deeksha , Jain Pankaj Kumar , Sisodia Yamini Singh , Bajpai Vivek
Published: April 2012

Thermophilic organisms can be defined as microorganisms which are adapted to live at high temperatures. The enzymes produce by thermophilic bacteria are capable of catalyzing biochemical reactions at high temperatures. Thermophilic bacteria are able to produce thermostable lipase enzymes capable of degradation of lipid at temperatures higher than those of mesophilic bacteria. Therefore, the isolation of thermophilic bacteria from natural sources and their identification are quite useful in terms of discovering thermophilic lipase enzymes. Due to great temperature fluctuation in hot arid and semi-arid regions of Rajasthan, this area could serve as a good source for new thermophilic lipase producing bacteria with novel industrially important properties. The main objective of this research is the isolation and estimation of industrially important thermophilic lipase enzyme produced by thermophilic bacteria, isolated from arid and semi-arid region of Rajasthan. For this research purpose, soil samples were collected from Churu, Sikar and Jhunjunu regions of Rajasthan. A total of 16 bacterial strains were isolated, and among these bacterial isolates only two thermophilic lipase producing bacteria were identified. The thermophilic lipase enzyme was estimated by qualitative and quantitative experiments. The isolate was identified as Bacillus sp. by microscopic, biochemical and molecular characterization. The optimum enzyme activity was observed at pH 8, temperature 60°C and 5% salt concentration at 24 hrs time duration. Lipases are useful in a variety of biotechnological fields such as food and dairy (cheese ripening, flavour development), detergent, pharmaceutical (naproxen, ibuprofen), agrochemical (insecticide, pesticide) and oleochemical (fat and oil hydrolysis, biosurfactant synthesis) industries. Lipases can be further used in many newer areas where they can serve as potential biocatalysts.
Pyruvate fuels mitochondrial respiration and proliferation of breast cancer cells: effect of monocarboxylate transporter inhibition
Authors: Diers Anne R. , Broniowska Katarzyna A. , Chang Ching-Fang , Hogg Neil
Published: April 2012

Recent studies have highlighted the fact that cancer cells have an altered metabolic phenotype, and this metabolic reprogramming is required to drive the biosynthesis pathways necessary for rapid replication and proliferation. Specifically, the importance of citric acid cycle-generated intermediates in the regulation of cancer cell proliferation has been recently appreciated. One function of MCTs (monocarboxylate transporters) is to transport the citric acid cycle substrate pyruvate across the plasma membrane and into mitochondria, and inhibition of MCTs has been proposed as a therapeutic strategy to target metabolic pathways in cancer. In the present paper, we examined the effect of different metabolic substrates (glucose and pyruvate) on mitochondrial function and proliferation in breast cancer cells. We demonstrated that cancer cells proliferate more rapidly in the presence of exogenous pyruvate when compared with lactate. Pyruvate supplementation fuelled mitochondrial oxygen consumption and the reserve respiratory capacity, and this increase in mitochondrial function correlated with proliferative potential. In addition, inhibition of cellular pyruvate uptake using the MCT inhibitor α-cyano-4-hydroxycinnamic acid impaired mitochondrial respiration and decreased cell growth. These data demonstrate the importance of mitochondrial metabolism in proliferative responses and highlight a novel mechanism of action for MCT inhibitors through suppression of pyruvate-fuelled mitochondrial respiration.
The Incidence of Infection after Posterior Cervical Spine Surgery: A 10 Year Review
Authors: Barnes Matt , Liew Sue
Published: April 2012

Background

The incidence of infection after posterior cervical spine surgery ranges from 0 to 18%. Higher rates have been reported after posterior procedures compared with anterior procedures, but these studies have been for small series. We report on our rate of surgical site infection (SSI) after posterior cervical spine surgery and the risk factors that influence these infections.

Methods

We retrospectively reviewed the records of 90 consecutive patients who underwent posterior cervical spine procedures at a major spinal referral center between 1998 and 2007. The main indications for surgery were trauma and degenerative conditions. Tumors and primary infections were excluded. Medical records of these patients were examined for evidence of SSI as diagnosed by Centers for Disease Control and Prevention criteria.

Results

Using stringent criteria for diagnosing SSI, we found 15 infected patients (16.67%). The postoperative use of a Philadelphia hard collar was found to be a significant risk factor for SSI with a relative risk of 15.30 (95% confidence interval 2.10 to 111.52). Almost half of infected patients (47%) required reoperation for wound debridement, with four requiring skin flap closure. All 15 patients had successful outcomes with complete resolution of their infection.

Conclusions

This study confirms a high incidence of SSI after posterior cervical surgery. The most significant risk factors for SSI were found to be a traumatic etiology and postoperative use of a collar. We believe it is important to develop strategies to minimize the risk of infection after posterior cervical surgery, which include questioning the postoperative use of collars.
Rationale of Revision Lumbar Spine Surgery
Authors: Elgafy Hossein , Vaccaro Alexander R. , Chapman Jens R. , Dvorak Marcel F.
Published: April 2012

Revision lumbar spine surgeries are technically challenging with inconstant outcome results. This article discusses the preoperative, intraoperative, as well as postoperative management in these difficult patients. Successful intervention requires a detailed history and physical examination and carefully chosen diagnostic tests. Preoperative planning is paramount in these cases. The decision-making process should address the timing of the surgery, surgical approach, level of interbody fusion required, correction of sagittal imbalance, type of osteotomy, location of the osteotomy, and the end of the construct. Surgeons should be prepared to manage associated complications such as dural tear and massive blood loss. The use of autograft and/or biologic graft is necessary to help in achieving a successful fusion. Postoperative management includes prophylactic antibiotic, anticoagulation, nutritional support, and brace.
Good Functional Outcome and Adjacent Segment Disc Quality 10 Years after Single-Level Anterior Lumbar Interbody Fusion with Posterior Fixation
Authors: Horsting Philip P. , Pavlov Paul W. , Jacobs Wilco C.H. , Obradov-Rajic Marina , de Kleuver Marinus
Published: April 2012

We reviewed the records of a prospective consecutive cohort to evaluate the clinical performance of anterior lumbar interbody fusion with a titanium box cage and posterior fixation, with emphasis on long-term functional outcome. Thirty-two patients with chronic low back pain underwent anterior lumbar interbody fusion and posterior fixation. Radiological and functional results (visual analogue scale [VAS] and Oswestry score) were evaluated. Adjacent segment degeneration (ASD) was evaluated radiologically and by magnetic resonance imaging (MRI). Twenty-five patients (78%) were available for follow-up. Functional scores showed significant improvement in pain and function up to the 2-year follow-up observation. At 4 years, there was some deterioration of the clinical results. At 10-year follow-up, results remained stable compared with 4-year results. MRI showed ASD in 3/25 (12%) above and 2/10 (20%) below index level (compared with absent preoperatively). ASD could not be related to clinical outcome in this study. Anterior lumbar interbody fusion and posterior fixation is safe and effective. Initial improvement in VAS and Oswestry scores is partly lost at the 4-year follow-up. Good clinical results are maintained at 10-year follow-up and are not related to adjacent segment degeneration.
Correlation between oxygen stoichiometry, structure, and opto-electrical properties in amorphous In2O3:H films
Authors: Koida Takashi , Shibata Hajime , Kondo Michio , Tsutsumi Koichi , Sakaguchi Akio , Suzuki Michio , Fujiwara Hiroyuki
Published: April 2012

We have characterized amorphous In2O3:H (H : ∼4 at.%) transparent conducting films by Rutherford backscattering spectrometry (RBS), thermal desorption spectroscopy, spectroscopic ellipsometry, and Hall measurements. The amorphous In2O3:H films have been fabricated at room temperature by sputtering of an In2O3 ceramic target under Ar, O2, and H2O vapor with variation of a flow ratio r(O2) = O2/(O2+Ar). We observe (i) signals originating from Ar in RBS spectra for all the films and (ii) desorption of H2O and Ar gases during post thermal annealing of the films. Furthermore, O2 desorption together with H2O and Ar is observed for the films grown at r(O2) > 0.375%, whereas In desorption together with H2O and Ar is observed for the films grown at r(O2) < 0.375%. These results suggest that the films have void and/or multi-vacancy rich structures inside the amorphous network, and the variety of atoms, such as Ar, H2O, and weakly bonded O and In, is present in the void structures for the films grown at O2-rich and O2-poor conditions, respectively. Corresponding to the structural changes, optical and electrical properties also change at r(O2) = 0.375%. For the films grown at r(O2) < 0.375%, we observe a broad absorption in the visible wavelengths that cannot be explained by free carrier absorption. In this film, the carrier mobility reduces rapidly with increasing carrier density. Analysis of spectroscopic ellipsometry and Hall measurements reveals that a large decrease in mobility is due to a large increase in carrier effective mass, in addition to the effect of ionized impurity scattering. In this article, we discuss the optical and transport properties with the variation of oxygen stoichiometry and microscopic structures in the amorphous In2O3:H films.
Effect of fiber orientation on shape and stability of air–water interface on submerged superhydrophobic electrospun thin coatings
Authors: Emami B. , Tafreshi H. Vahedi , Gad-el-Hak M. , Tepper G. C.
Published: April 2012

To better understand the role of fiber orientation on the stability of superhydrophobic electrospun coatings under hydrostatic pressures, an integro-differential equation is developed from the balance of forces across the air–water interface between the fibers. This equation is solved numerically for a series of superhydrophobic electrospun coatings comprised of random and orthogonal fiber orientations to obtain the exact 3D shape of the air–water interface as a function of hydrostatic pressure. More important, this information is used to predict the pressure at which the coatings start to transition from the Cassie state to the Wenzel state, i.e., the so-called critical transition pressure. Our results indicate that coatings composed of orthogonal fibers can withstand higher elevated hydrostatic pressures than those made up of randomly orientated fibers. Our results also prove that thin superhydrophobic coatings can better resist the elevated pressures. The modeling methodology presented here can be used to design nanofibrous superhydrophobic coatings for underwater applications.
Two-dimensional order-disorder transition of argon monolayer adsorbed on graphitized carbon black: Kinetic Monte Carlo method
Authors: Ustinov E. A. , Do D. D.
Published: April 2012

We present results of application of the kinetic Monte Carlo technique to simulate argon adsorption on a graphite surface at temperatures below and above the triple point. We show that below the triple point the densification of the adsorbed layer with loading results in the rearrangement of molecules to form a hexagonal structure, which is accompanied by the release of an additional heat, associated with this disorder-order transition. This appears as a spike in the plot of the heat of adsorption versus loading at the completion of a monolayer on the surface. To describe the details of the adsorbed phase, we analyzed thermodynamic properties and the effects of temperature on the order-disorder transition of the first layer.
Readout of carbon nanotube vibrations based on spin-phonon coupling
Authors: Ohm C. , Stampfer C. , Splettstoesser J. , Wegewijs M. R.
Published: April 2012

We propose a scheme for spin-based detection of the bending motion in suspended carbon-nanotubes, using the curvature-induced spin-orbit interaction. We show that the resulting effective spin-phonon coupling can be used to down-convert the high-frequency vibration-modulated spin-orbit field to spin-flip processes at a much lower frequency. This vibration-induced spin-resonance can be controlled with an axial magnetic field. We propose a Pauli spin blockade readout scheme and predict that the leakage current shows pronounced peaks as a function of the external magnetic field. Whereas the resonant peaks allow for frequency readout, the slightly off-resonant current is sensitive to the vibration amplitude.
Boundary layer development in the flow field between a rotating and a stationary disk
Authors: van Eeten K. M. P. , van der Schaaf J. , Schouten J. C. , van Heijst G. J. F.
Published: April 2012

This paper discusses the development of boundary layers in the flow of a Newtonian fluid between two parallel, infinite disks. One of the disks is rotating at a constant angular velocity while the other remains stationary. An analytical series approximation and a numerical solution method are used to describe the velocity profiles of the flow. Both methods rely on the commonly used similarity transformation first proposed by Von Kármán [T. von Kármán, ZAMM 1, 233 (1921)]10.1002/zamm.19210010401. For Reh < 18, the power series analytically describe the complete velocity profile. With the numerical model a Batchelor type of flow was observed for Reh > 300, with two boundary layers near the disks and a non-viscous core in the middle. A remarkable conclusion of the current work is the coincidence of the power series’ radius of convergence, a somewhat abstract mathematical notion, with the physically tangible concept of the boundary layer thickness. The coincidence shows a small deviation of only 2% to 4%.
Broadband conversion of TE01 mode for the coaxial gyrotron at low terahertz
Authors: Chen Nai-Ching , Chang Tsun-Hsu , Yang Ching-Yuan
Published: April 2012

This paper investigates the mode characteristics of coaxial waveguide and proposes a mechanism to convert a rectangular TE10 mode to a coaxial TE01 mode. Four-wave, eight-wave, and sixteen-wave coupling structures are developed to selectively excite the desired coaxial TE01 mode with different outer to inner radius ratios. The proposed structures can suppress the unwanted parasitic modes and lead to high converting efficiency with broad bandwidth. The measured 3-dB transmission bandwidths at W-band are 13.5 GHz (14.3%), 8.5 GHz (9.0%), and 12.2 GHz (13.0%), respectively. These coaxial TE01 mode converters are mutually non-overlapping in their coaxial cross-sections, and therefore can be joined concentrically and utilized to develop a multi-channel gyrotron traveling-wave tube or backward-wave oscillator in a single superconducting magnet.
Nucleation of colloids and macromolecules: Does the nucleation pathway matter?
Authors: Lutsko James F.
Published: April 2012

A recent description of diffusion-limited nucleation based on fluctuating hydrodynamics that extends classical nucleation theory predicts a very non-classical two-step scenario whereby nucleation is most likely to occur in spatially extended, low-amplitude density fluctuations. In this paper, it is shown how the formalism can be used to determine the maximum probability of observing any proposed nucleation pathway, thus allowing one to address the question as to their relative likelihood, including of the newly proposed pathway compared to classical scenarios. Calculations are presented for the nucleation of high-concentration droplets in a low-concentration solution of globular proteins and it is found that the relative probabilities (new theory compared to classical result) for reaching a critical nucleus containing Nc molecules scales as \documentclass[12pt]{minimal}\begin{document}$e^{-N_c/3}$\end{document}e−Nc/3 thus indicating that for all but the smallest nuclei, the classical scenario is extremely unlikely.
Nano conductive particle dispersed percolative thin film ceramics with high permittivity and high tunability
Authors: Wang Zongrong , Hu Tao , Li Xiaoge , Han Gaorong , Weng Wenjian , Ma Ning , Du Piyi
Published: April 2012

Conductive Ag nanoparticles dispersed Pb0.4Sr0.6TiO3 (PST) thin film was obtained by dual complexing agents of citric acid and acetylacetone controlled sol route heated in air without using reduction atmosphere. Percolation behaviour occurs with the nano-particle fraction adjacent to a threshold. Dielectric constant of the percolative composite thin film with Ag nanoparticles near the threshold is 4 times higher than that of the one without Ag nanoparticles. Tunability of the PST thin film increases dramatically by 42% with inner electric field by Ag nanoparticles inside.
Lens-less edge-pumped high power microchip laser
Authors: Kong Weipeng , Taira Takunori
Published: April 2012

We report the demonstration of compact lens-less microchip laser, which is directly pumped by single-emitter diode chips from multiple directions. The lens-less design makes the microchip laser more compact; the multi-direction designable pump schemes can realize a Gaussian shape. As a preliminary result, continuous wave output power of 32.5 W and slope efficiency of 45% was obtained by 9-direction pumped Yb:YAG ceramic microchip. Further, 27.2 W single peak Gaussian beam was obtained by a small adjustment of the output mirror. Power scalability is easy by increasing the number of diodes to 27 to achieve 100-watt-level microchip laser.
The improvement of the field emission properties from graphene films: Ti transition layer and annealing process
Authors: Li Jun , Chen Jiangtao , Luo Baomin , Yan Xingbin , Xue Qunji
Published: April 2012

Chemical-reduced graphene oxide (rGO) films were deposited on titanium (Ti)-coated silicon substrates by a simple electrophoretic deposition. The rGO films were annealed under argon atmosphere at different temperatures. The morphology and microstructure of the rGO films before and after annealing were characterized using scanning electron microscope, X-ray diffraction and Raman spectroscope. The field emission behaviors from these rGO films were investigated. The results show that, Ti-based transition layer can improve the stability of field emission from the rGO film, and the annealing at appropriate temperature is in favor of the field emission. Particularly, the rGO film displays an unexpected vacuum breakdown phenomenon at a relatively high current density. In addition, it is found that the field emission property of the rGO film is dependent on anode-sample distance and the film exhibits lower turn on field at larger anode-sample distance.
Isolated sub-10 attosecond pulse generation by a 6-fs driving pulse and a 5-fs subharmonic controlling pulse
Authors: Wang Yunhui , Wu Haiping , Chen Ying , Lu Zelin , Yu Chao , Shi Qi , Deng Kaiming , Lu Ruifeng
Published: April 2012

We theoretically study high-order harmonic generation by quantum path control in a special two-color laser field, which is synthesized by a 6 fs/800 nm fundamental pulse and a weaker 5 fs/1600 nm subharmonic controlling pulse. Single quantum path is selected without optimizing any carrier phase, which not only broadens the harmonic bandwidth to 400 eV, but also enhances the harmonic conversion efficiency in comparison with the short-plus-long scheme, which is based on 5 fs/800 nm driving pulse and 6 fs/1600 nm control pulse. An isolated 8-attosecond pulse is produced with currently available ultrafast laser sources.
Efficacy of 35% PEROX-AID (Hydrogen Peroxide) in Reducing an Infestation of Gyrodactylus salmonis in Freshwater-Reared Rainbow Trout
Authors: Bowker James D , Carty Daniel , Dotson Miranda M
Published: April 2012

Gyrodactylus salmonis is a monogenean ectoparasite that can infest a variety of captive-reared salmonid fishes. The physical damage inflicted during severe infestations can cause osmoregulatory disturbances and potentially render individuals more vulnerable to secondary pathogens. If not treated, G. salmonis infestations can reduce growth and survival in affected fish populations. Many chemical compounds have been used to treat Gyrodactylus infestations; however, little information has been published about the use of hydrogen peroxide (H2O2) for Gyrodactylus control. Consequently, we conducted a trial to evaluate the efficacy of H2O2 in reducing a natural infestation of G. salmonis in freshwater-reared, adult rainbow trout Oncorhynchus mykiss. Triplicate tanks of adult rainbow trout (20 fish per tank; length = 45.6 ± 5.8 cm and weight = 1.3 ± 0.4 kg, mean ± SD) were exposed to a static bath of H2O2 at a target dosage of 50 mg/L or hatchery water (sham treatment) for 30 min/d on two alternate days. Treatment efficacy was assessed at 2 and 7 d posttreatment via light microscopy examination of skin scrapes (one per fish) taken from 10 fish per tank on each day. At 2 d posttreatment, the mean abundance of G. salmonis in the H2O2-treated group (0.1 ± 0.3 G. salmonis individuals per skin scrape) was significantly different from that observed in the sham-treated group (34.4 ± 43.2 individuals per skin scrape). Also, at 7 d posttreatment, the mean abundance of G. salmonis in the H2O2-treated group (0.1 ± 0.3 individuals per skin scrape) was significantly different from that observed in the sham-treated group (38.5 ± 77.4 individuals per skin scrape). The percent reduction in mean abundance (treated group compared with control group) was greater than 99% at both 2 and 7 d posttreatment. In conclusion, the H2O2 treatment regimen that we used significantly reduced a natural infestation of G. salmonis in freshwater-reared, adult rainbow trout.
Effects of Abrupt pH Increases on Survival of Different Ages of Young Channel Catfish and Hybrid Catfish
Authors: Mischke Charles C , Chatakondi Nagaraj
Published: April 2012

A previous study showed that fry of channel catfish Ictalurus punctatus are sensitive to pH increases but tolerant of pH decreases. This study determined the tolerance of channel catfish and hybrid catfish (female channel catfish × male blue catfish I. furcatus) sac fry, swim-up fry, and fingerlings to abrupt pH increases. Sac fry, swim-up fry, and fingerlings of channel catfish and hybrid catfish are sensitive to abrupt pH increases and become more tolerant with age or size. Hybrid catfish sac fry were more tolerant than channel catfish sac fry at lower pH increases, as evidenced by their higher 24-h LC10 (0.38 and 0.13 pH unit increases, respectively) and 24-h LC50 (0.48 and 0.36 pH unit increases, respectively). However, the 24-h LC90 for hybrid catfish sac fry (0.62 pH unit) was much lower than that for channel catfish (1.03 pH unit), showing that at higher pH increases hybrids are less tolerant. Channel catfish swim-up fry were more tolerant of pH increases (24-h LC50 = 1.28 pH units) than were hybrids (24-h LC50 = 0.83 pH units), but hybrid catfish fingerlings (24-h LC50 = 1.54 pH units) were more tolerant of pH increases than channel catfish fingerlings (24-h LC50 = 1.33 pH units). When comparing fish acclimated to different starting pH levels, lethal concentration values increased correspondingly. This indicates that pH sensitivity is due to upper lethal pH limits rather than abrupt pH changes.
Geomorphic histories for river and catchment management
Authors: Wasson R. J.
Published: April 2012

River and catchment management usually proceeds from the identification of an undesirable state (e.g. pollution, sedimentation, excessive water extraction, dams, invasion by exotic species) to a strategy for reaching a desirable state described as a target. Desirable states are usually determined from community values, economic assessments and ecosystem functions, or a combination of these. Where a catchment is highly disturbed, the target is usually not a natural state, as that cannot be achieved while maintaining human uses, and a history is needed to document the disturbance, understand its cause and define the ‘existence space’, that is, the range of natural states that have occurred in the past. Where a catchment is less disturbed, a former natural state could provide a target for management. But which of the many natural (equilibrium) states that have occurred in the past should be the target? The paper reviews what is known of the quantitative difference between pre- and post-disturbance states, searches for the presence or otherwise of equilibrium and comments on the utility of this information for catchment management. The focus is on erosion and sediment transport.
The fluvial record of climate change
Authors: Macklin M. G. , Lewin J. , Woodward J. C.
Published: April 2012

Fluvial landforms and sediments can be used to reconstruct past hydrological conditions over different time scales once allowance has been made for tectonic, base-level and human complications. Field stratigraphic evidence is explored here at three time scales: the later Pleistocene, the Holocene, and the historical and instrumental period. New data from a range of field studies demonstrate that Croll–Milankovitch forcing, Dansgaard–Oeschger and Heinrich events, enhanced monsoon circulation, millennial- to centennial-scale climate variability within the Holocene (probably associated with solar forcing and deep ocean circulation) and flood-event variability in recent centuries can all be discerned in the fluvial record. Although very significant advances have been made in river system and climate change research in recent years, the potential of fluvial palaeohydrology has yet to be fully realized, to the detriment of climatology, public health, resource management and river engineering.
Retrotransposon insertion targeting: a mechanism for homogenization of centromere sequences on nonhomologous chromosomes
Authors: Birchler James A. , Presting Gernot G.
Published: April 2012

The centromeres of most eukaryotic organisms consist of highly repetitive arrays that are similar across nonhomologous chromosomes. These sequences evolve rapidly, thus posing a mystery as to how such arrays can be homogenized. Recent work in species in which centromere-enriched retrotransposons occur indicates that these elements preferentially insert into the centromeric regions. In two different Arabidopsis species, a related element was recognized in which the specificity for such targeting was altered. These observations provide a partial explanation for how homogenization of centromere DNA sequences occurs.
Multiphoton Stimulation of Neurons and Spines
Authors: Hirase Hajime , Nikolenko Volodymyr , Yuste Rafael
Published: April 2012

This protocol describes an optical method to directly stimulate a neuron (i.e., without using any caged chemicals or genetic probes) using an infrared ultrafast mode-locked laser. This method can trigger action potentials in a targeted neuron when a laser beam is applied to the somatic membrane. Alternatively, it can mimic excitatory postsynaptic potentials (EPSPs) when applied to dendritic spines. The protocol has been applied successfully using juvenile (postnatal day 7–14) C57 mouse neocortical and hippocampal acute slices (∼300-µm thickness). It can be used in conjunction with slices bulk loaded with calcium indicators, such as Fura-2 AM.
Building an Imaging Chamber for In Vivo Imaging of Drosophila Larvae
Authors: Andlauer Till F.M. , Sigrist Stephan J.
Published: April 2012

In the past decade, a significant number of proteins involved in the developmental assembly and maturation of synapses have been identified. However, detailed knowledge of the molecular processes underlying developmental synapse assembly is still sparse. We have developed an approach that makes extended in vivo imaging of selected proteins in live Drosophila larvae feasible at a single-synapse resolution. The intact larvae are anesthetized and noninvasively imaged with confocal microscopy. This method allows for both protein trafficking and protein turnover kinetics to be studied at various points in time during the development of an animal. These data contribute to our understanding of synaptic assembly under in vivo conditions. This protocol describes the assembly of the imaging chamber needed for in vivo imaging of Drosophila larvae. It also covers the construction of an appropriate anesthetization device.
General Principles for Measuring Resting Membrane Potential and Ion Concentration Using Fluorescent Bioelectricity Reporters
Authors: Adams Dany S. , Levin Michael
Published: April 2012

This overview provides the basic information needed to understand, choose, and use fluorescent bioelectricity reporters (FBRs), where bioelectricity is defined as cell processes that involve ions or ion flux. While traditional methods of measuring these characteristics are still valid and necessary, the utility of FBRs has facilitated measurement of these properties under circumstances that are not possible with microelectrodes. Specifically, these dyes can be used to achieve subcellular resolution, to measure many cells simultaneously in vivo, and to track bioelectric gradients over long time periods despite cell movements and divisions. This article covers the basic principles underlying the interpretation of the dye signals, describes essential steps for troubleshooting, optimizing data collection, analysis, and presentation, and provides compilations of information that are useful for choosing FBRs for particular projects.