bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcranial Measurement of Cerebral Microembolic Signals During Pulmonary Vein Isolation
Authors: Nagy-Baló Edina , Tint Diana , Clemens Marcell , Beke Ildikó , Kovács Katalin Réka , Csiba László , Édes István , Csanádi Zoltán
Published: April 2013

Background—

Pulmonary vein isolation has increasingly been used to cure atrial fibrillation, but concerns have recently been raised that subclinical brain damage may occur because of microembolization during these procedures. We compared the occurrence of bubble formation seen on intracardiac echocardiography and the microembolic signals (MESs) detected by transcranial Doppler on the use of different ablation techniques and anticoagulation strategies.

Methods and Results—

This prospective study included 35 procedures in 34 consecutive patients (age, 52; SD, 12.8 years; female:male 9:25). Pulmonary vein isolation was performed with a cryoballoon and the conventional anticoagulation protocol (activated clotting time >250 s) in 10 procedures (group 1), with a multipolar duty-cycled radiofrequency pulmonary group 2), and with regime a pulmonary vein ablation catheter with an aggressive anticoagulation (activated clotting time >320 s) in 13 procedures (group 3). The mean total numbers of MESs detected during the procedures were 833.7 (SD, 727.4) in group 1, 3142.6 (SD, 1736.4) in group 2, and 2204.6 (SD, 1078.1) in group 3 (
P
=0.0005). MESs were detected mostly during energy delivery in the pulmonary vein ablation catheter groups, whereas a relatively even distribution of emboli formation was seen during cryoballoon ablations. A significant correlation was found in all groups between the degree of bubble formation on intracardiac echocardiography and the number of MESs (
P
=0.0000).

Conclusions—

Duty-cycled radiofrequency ablation is associated with significantly more MESs, even when more aggressive anticoagulation is applied. With both techniques most of these microemboli are gaseous in nature.
Prognostic Value of Exercise Testing During Heart Transplant Evaluation in Children
Authors: Lytrivi Irene D. , Blume Elizabeth D. , Rhodes Jonathan , Dillis Shay , Gauvreau Kimberlee , Singh Tajinder P.
Published: April 2013

Background—

Maximum oxygen consumption (peak VO
2
) <50% predicted on exercise testing is a class I indication for heart transplant (HT) listing in children. This recommendation is based on exercise data in adults. We assessed the association of peak VO
2
<50% predicted during HT evaluation with freedom from death or deterioration in children.

Methods and Results—

We analyzed all children who underwent exercise testing during HT evaluation at our center between 2002 and 2011. Patients with peak VO
2
<50% predicted were compared with those with peak VO
2
≥50% predicted for the composite outcome of death before HT, initiation of mechanical circulatory support, and HT at highest urgency status, using time-to-event analyses. There were 50 children in the study (median age, 15 years; interquartile range, 13–17 years; 24 girls; 18 with palliated single ventricle). Overall, 24 children reached the composite end point. Peak VO
2
<50% predicted was associated with outcome in children with biventricular circulation (hazard ratio, 4.7; 95% confidence interval, 1.8–12.3;
P
<0.001) but not in those with a palliated single ventricle (hazard ratio, 1.3; 95% confidence interval, 0.1–12.0;
P
=0.80). Similarly, VE/VCO
2
slope ≥34 was associated with outcome in children with biventricular circulation (hazard ratio, 2.7; 95% confidence interval, 1.1–7.1;
P
<0.001) but not in children with a palliated single ventricle.

Conclusions—

Exercise testing during HT evaluation in children with biventricular circulation identified those at higher risk of death or deterioration in this small study. Larger studies are needed to assess the role of exercise testing during HT evaluation in children with a palliated single ventricle.
Aged parents’ experiences during a critical illness trajectory and after the death of an adult child: A review of the literature
Authors: Van Humbeeck Liesbeth , Piers Ruth D , Van Camp Sigrid , Dillen Let , Verhaeghe Sofie TL , Van Den Noortgate Nele J
Published: April 2013

Background:

Given the growing life expectancy, the likelihood increases that health-care providers are confronted with older people having an adult child with a life-limiting disease.

Aim:

This literature review aimed to (1) explore the experiences of aged parents with regard to their position and role as a parent of an adult child with a life-limiting illness, (2) detect gaps in the existing literature and (3) make recommendations for future research.

Design:

A literature search of English articles, including both quantitative and qualitative designs.

Data sources:

Four electronic databases and the reference lists of included studies.

Results:

In total, 19 studies (7 quantitative and 12 qualitative) were included. Few studies describe the experiences of older people whose adult child has cancer or has died of cancer. Existing studies are merely descriptive and give no concrete recommendations for health-care providers in daily practice. The studies suggest that aged parents carry deep burdens from the prospect of losing their adult child. Aged parents want to stay involved but need to reconfigure their parent role. As soon as the cancer diagnosis is disclosed, parents are confronted with a re-awakening of parental nurturing, which clashes with the autonomy of the adult child. Even after the adult child is deceased, older parents retain the image of themselves as parents.

Conclusions:

There is a need for more in-depth research to understand the lived experience of these parents and what health-care providers can do to assist them.
The challenges of contamination in evaluations of childhood interventions
Authors: Doyle Orla , Hickey Claire
Published: April 2013

Contamination in social programmes occurs when the control group either actively or passively receive some or all of the intervention intended for the treatment group. While contamination is considered a potential threat to the internal validity of an evaluation, there is relatively little evidence on the magnitude and prevalence of contamination in social programmes and the extent to which it can bias the estimates of programme effectiveness. The aim of this article is to document the challenges of contamination in a number of childhood interventions currently being evaluated in Ireland using experimental and quasi-experimental methods. The article documents the experiences of addressing contamination at the professional staff level, the parent and child level and the dissemination level. It describes the methods employed to minimize contamination and the procedures used for measuring it. Finally, the consequences of contamination for both programme implementation and the research design are discussed.
Adolescent Leadership
Authors: Archard Nicole
Published: April 2013

This research investigated the female adolescent view of leadership by giving voice to student leaders through focus group discussions. The questions: What is leadership? Where/how was leadership taught?, and How was leadership practised? were explored within the context of girls’ schools located in Australia, with one school located in South Africa. The findings of this research indicated that girls not only had an understanding of leadership, they also actively performed it. Students viewed leadership as the active process of working with others in a positive way. Leadership was mostly taught through specific programmes and activities and practised both formally and informally by students. It was also acknowledged that leadership was often learnt through experience. Further exploration of this concept is needed in order to ascertain the ways in which these understandings of leadership can be better utilized in order to develop the leadership potential of girls when they enter adulthood.
MEK and the inhibitors: from bench to bedside
Authors: Akinleye Akintunde , Furqan Muhammad , Mukhi Nikhil , Ravella Pavan , Liu Delong
Published: April 2013

Four distinct MAP kinase signaling pathways involving 7 MEK enzymes have been identified. MEK1 and MEK2 are the prototype members of MEK family proteins. Several MEK inhibitors are in clinical trials. Trametinib is being evaluated by FDA for the treatment of metastatic melanoma with BRAF V600 mutation. Selumetinib has been studied in combination with docetaxel in phase II randomized trial in previously treated patients with advanced lung cancer. Selumetinib group had better response rate and progression-free survival. This review also summarized new MEK inhibitors in clinical development, including pimasertib, refametinib, PD-0325901, TAK733, MEK162 (ARRY 438162), RO5126766, WX-554, RO4987655 (CH4987655), GDC-0973 (XL518), and AZD8330.
A novel role for Pax6 in the segmental organization of the hindbrain
Authors: Kayam Galya , Kohl Ayelet , Magen Zohar , Peretz Yuval , Weisinger Karen , Bar Avi , Novikov Orna , Brodski Claude , Sela-Donenfeld Dalit
Published: April 2013

Complex patterns and networks of genes coordinate rhombomeric identities, hindbrain segmentation and neuronal differentiation and are responsible for later brainstem functions. Pax6 is a highly conserved transcription factor crucial for neuronal development, yet little is known regarding its early roles during hindbrain segmentation. We show that Pax6 expression is highly dynamic in rhombomeres, suggesting an early function in the hindbrain. Utilization of multiple gain- and loss-of-function approaches in chick and mice revealed that loss of Pax6 disrupts the sharp expression borders of Krox20, Kreisler, Hoxa2, Hoxb1 and EphA and leads to their expansion into adjacent territories, whereas excess Pax6 reduces these expression domains. A mutual negative cross-talk between Pax6 and Krox20 allows these genes to be co-expressed in the hindbrain through regulation of the Krox20-repressor gene Nab1 by Pax6. Rhombomere boundaries are also distorted upon Pax6 manipulations, suggesting a mechanism by which Pax6 acts to set hindbrain segmentation. Finally, FGF signaling acts upstream of the Pax6-Krox20 network to regulate Pax6 segmental expression. This study unravels a novel role for Pax6 in the segmental organization of the early hindbrain and provides new evidence for its significance in regional organization along the central nervous system.
HECT-E3 ligase ETC-1 regulates securin and cyclin B1 cytoplasmic abundance to promote timely anaphase during meiosis inC. elegans
Authors: Wang Ruishan , Kaul Zeenia , Ambardekar Charuta , Yamamoto Takaharu G. , Kavdia Kanisha , Kodali Kiran , High Anthony A. , Kitagawa Risa
Published: April 2013

The anaphase inhibitor securin plays a crucial role in regulating the timing of sister chromatid separation during mitosis. When sister chromatid pairs become bioriented, the E3 ligase anaphase promoting complex/cyclosome (APC/C) ubiquitylates securin for proteolysis, triggering sister chromatid separation. Securin is also implicated in regulating meiotic progression. Securin protein levels change sharply during cell cycle progression, enabling its timely action. To understand the mechanism underlying the tightly regulated dynamics of securin, we analyzed the subcellular localization of the securin IFY-1 during C. elegans development. IFY-1 was highly expressed in the cytoplasm of germ cells. The cytoplasmic level of IFY-1 declined immediately following meiosis I division and remained low during meiosis II and following mitoses. We identified a C. elegans homolog of another type of E3 ligase, UBE3C, designated ETC-1, as a regulator of the cytoplasmic IFY-1 level. RNAi-mediated depletion of ETC-1 stabilized IFY-1 and CYB-1 (cyclin B1) in post-meiosis I embryos. ETC-1 knockdown in a reduced APC function background caused an embryonic lethal phenotype. In vitro, ETC-1 ubiquitylates IFY-1 and CYB-1 in the presence of the E2 enzyme UBC-18, which functions in pharyngeal development. Genetic analysis revealed that UBC-18 plays a distinct role together with ETC-1 in regulating the cytoplasmic level of IFY-1 during meiosis. Our study reports a novel mechanism, mediated by ETC-1, that co-operates with APC/C to maintain the meiotic arrest required for proper cell cycle timing during reproduction.
Mechanical and energetic consequences of rolling foot shape in human walking
Authors: Adamczyk Peter G. , Kuo Arthur D.
Published: April 2013

During human walking, the center of pressure under the foot progresses forward smoothly during each step, creating a wheel-like motion between the leg and the ground. This rolling motion might appear to aid walking economy, but the mechanisms that may lead to such a benefit are unclear, since the leg is not literally a wheel. We propose that there is indeed a benefit, but less from rolling than from smoother transitions between pendulum-like stance legs. The velocity of the body center of mass (COM) must be redirected in that transition, and a longer foot reduces the work required for the redirection. Here we develop a dynamic walking model that predicts different effects from altering foot length as opposed to foot radius, and test it by attaching rigid, arc-like foot bottoms to humans walking with fixed ankles. The model suggests that smooth rolling is relatively insensitive to arc radius, whereas work for the step-to-step transition decreases approximately quadratically with foot length. We measured the separate effects of arc-foot length and radius on COM velocity fluctuations, work performed by the legs, and metabolic cost. Experimental data (N = 8) show that foot length indeed has much greater effect on both the mechanical work of the step-to-step transition (23% variation, P = 0.04) and the overall energetic cost of walking (6%, P = 0.03) than foot radius (no significant effect, P > 0.05). We found a minimum of metabolic energy cost for an arc foot length about 29% of leg length, roughly comparable to human foot length. Our results suggest that the foot’s apparently wheel-like action derives less benefit from rolling per se than from reduced work to redirect the body COM.
Colour vision and response bias in a coral reef fish
Authors: Cheney Karen , Newport Cait , McClure Eva , Marshall Justin
Published: April 2013

Animals use coloured signals for a variety of communication purposes, including to attract potential mates, recognize individuals, defend territories and warn predators of secondary defences (aposematism). To understand the mechanisms that drive the evolution and design of such visual signals, it is important to understand the visual systems and potential response biases of signal receivers. Here, we provide raw data on the spectral capabilities of a coral reef fish, Picasso triggerfish Rhinecanthus aculeatus, which are potentially trichromatic with three cone sensitivities of 413 nm (single cone), 480 nm (double cone, medium sensitivity), 528 nm (double cone, long sensitivity) and a rod sensitivity of 498 nm. The ocular media have a 50% transmission cut off at 405 nm. Behavioural experiments confirmed colour vision over their spectral range; triggerfish were significantly more likely to choose coloured stimuli over grey distractors, irrespective of luminance. We then examined whether response biases existed towards coloured and patterned stimuli to provide insights into how visual signals - in particular, aposematic colouration - may evolve. Triggerfish showed a preferential foraging response bias to red and green stimuli, in contrast to blue and yellow, irrespective of pattern. There was no response bias to patterned over monochromatic non-patterned stimuli. A foraging response bias towards red in fish differs to that of avian predators, who often avoid red food items. Red is frequently associated with warning colouration in terrestrial environments (ladybirds, snakes, frogs), whilst blue is used in aquatic environments (blue-ringed octopus, nudibranchs); whether the design of warning (aposematic) displays is a cause or consequence of response biases is unclear.
Horizontal Capacity Coordination for Risk Management and Flexibility: Pay Ex Ante or Commit a Fraction of Ex Post Demand?
Authors: Wu Xiaole , Kouvelis Panos , Matsuo Hirofumi
Published: April 2013

Motivated by the dual-sourcing and contracting practices in the semiconductor industry, we study two prevailing types of contracts that deal with horizontal-capacity-coordination issues between two possible sources: an integrated device manufacturer (IDM) and a foundry. IDMs both design and manufacture semiconductor devices, whereas foundries concentrate only on manufacturing. Because production capacity is capital intensive, IDMs often make decisions on whether to manufacture each device internally or subcontract to foundries. Two types of contracts are most frequently used in such settings. Under α-contracts, a fixed fraction α of ex post realized demand is committed to subcontract to the foundry and serves as an incentive for the foundry to build capacity. Under reservation contracts, an ex ante capacity reservation fee is paid to the foundry as an incentive to build capacity. Because of the different nature of incentives under these contracts, it is unclear which type of contract maximizes the IDM's expected profit. Furthermore, IDMs and their customers often prefer dual sourcing to sole sourcing for risk-management purposes. This paper studies the relationship between the two types of contracts, both with and without dual-sourcing constraints and shows the effect of a dual-sourcing preference on contract selection. Our analysis offers supporting rationale for the coexistence of α-contracts and reservation contracts in practice and provides insights on horizontal capacity coordination beyond the semiconductor industry.
Phasing Locking of High Power Fiber Amplifier Arrays
Authors: Shay T. M. , Baker J. T. , Sanchez Anthony D. , Robin C. A. , Vergien C. L. , Flores Angel , Zerinque C. , Gallant D. , Lu Chunte A. , Pulford Benjamin , Bronder Capt. T. J. , Lucero Arthur
Published: April 2013

We report locking the phase of a five element 725-W amplifier array and in addition we report phase locking off the backscatter from a remote object. The rms phase error was measured to be λ/60.
Over 20W pico-second vortex output from a large-mode-area fiber MOPA system
Authors: Tanaka Yuichi , Koyama Mio , Okida Masahito , Miyamoto Katsuhiko , Omatsu Takashige
Published: April 2013

We scale the power of a pico-second vortex master-oscillator power amplifier system based on a stressed large-mode-area fiber amplifier. The vortex output power of >20 W with the corresponding peak power of >30kW was obtained.
Reduction of timing-jitter in a passively Q-switched microchip laser using self-injection seeding
Authors: Steinmetz A. , Nodop D. , Limpert J. , Tünnermann A.
Published: April 2013

We present an efficient and simple technique for the reduction of the timing jitter in a passively Q-switched microchip laser by self-injection seeding using an optical fiber as a delay line. The jitter is reduced by several orders of magnitude to the order of the pulse duration. With possible pulse durations down to 50 ps, tunable repetition rates up to few MHz and jitter-reduced operation such microchip lasers are a very attractive seed source for manifold applications.
Periodically Poled KTiOAsO4 For Mid-Infrared Light Generation
Authors: Zukauskas Andrius , Thilmann Nicky , Pasiskevicius Valdas , Laurell Fredrik , Canalias Carlota
Published: April 2013

A periodically poled KTiOAsO4 crystal was fabricated at room temperature. The poled crystal shows a deff of 10.1 pm/V and gives a parametric conversion efficiency of 45%.
First theoretical and experimental demonstration of quantum correlations of triple photons
Authors: Dot Audrey , Bencheikh Kamel , Boulanger Benoît , Levenson Ariel , Segonds Patricia , Gérardin Antoine , Félix Corinne
Published: April 2013

We give prominence to the first experimental and theoretical demonstration of quantum correlations of triple photons produced by a true phase-matched third order non linear process in a KTP crystal pumped at 532 nm.
High Power SHG at 515 nm by means of extracavity frequency conversion of sub-picosecond pulses from a mode-locked Innoslab MOPA
Authors: Gronloh B. , Mans T. , Rußbüldt P. , Jungbluth B. , Wester R. , Hoffmann D.
Published: April 2013

190 W output power at 515 nm were achieved by extracavity frequency conversion of sub700 fs pulses at 76 MHz. Numerical simulations considering thermal effects and group velocity dispersion are applied to model the conversion.
KGW and diamond picosecond visible Raman lasers
Authors: Spence David J. , Granados Eduardo , Pask Helen M. , Mildren Richard P.
Published: April 2013

We present three synchronously pumped Raman lasers generating picosecond visible laser pulses. Using KGW and diamond, we efficiently convert the wavelength of standard neodymium picosecond laser sources, as well as substantially compressing their pulse duration.
Compact post-compression system for peak power enhancement of an ultrafast diode-pumped laser
Authors: Courjaud Antoine , Mével Eric , Constant Eric , Mottay Eric
Published: April 2013

We report on a compact system based on post-compression of an ytterbium ultrafast laser, using Nitrogen-filled hollow fiber, delivering 60fs pulses with 330µJ energy at 2kHz and 200µJ at 5kHz.
Recent Advances in Fluoride Crystal Based GaN-Diode-Pumped Green Praseodymium Lasers
Authors: Hansen N.-O. , Fechner M. , Petermann K. , Huber G. , Parisi D. , Tonelli M.
Published: April 2013

We report the first diode-pumped laser oscillation of Pr:BaY2F8 in the green spectral range, related crystal growth and basic spectroscopic properties. Furthermore, recent results of experiments with Pr:LiYF4, showing efficient green laser action, are presented.
Efficient Resonantly-Pumped Eye-Safe Composite Ceramic Er:YAG Laser
Authors: Ter-Gabrielyan N. , Merkle L. D. , Dubinskii M. , Kupp E. R. , Messing G. L.
Published: April 2013

Laser operation of a composite ceramic Er:YAG rod is demonstrated at 1645 nm with a slope efficiency of 56.9% under resonant pumping at 1532.3 nm. This is believed to be the first reported composite ceramic Er:YAG laser.
Suppression of Parasitic Laser Processes in Cladding Pumped Er:Yb-Codoped Fiber Amplifier via Auxiliary Signal at 1.0 μm
Authors: Kuhn Vincent , Weßels Peter , Neumann Jörg , Kracht Dietmar
Published: April 2013

We report on an Er:Yb-codoped cladding pumped fiber amplifier simultaneously seeded at 1556nm and 1064nm. We were able to demonstrate stable output power of 8.7W at 1556nm with an amplifier gain of >22dB.
Cavity-Dumped Picosecond Mode-Locked Nd:YVO4 laser for Micro-Machining Applications
Authors: Meier J. , Wegner U. , Lederer M. J.
Published: April 2013

We present a Nd:YVO4 cavity-dumper with average power of 10W at 1MHz and pulse energies up to 15.6μJ at 10ps. These parameters render it a compact source for picosecond micro-machining, alternative to more complex schemes.
Passively Q-Switched Nd:YAG/Cr4+:YAG Laser with a Volume Bragg Gratings Output Coupler
Authors: Pavel N. , Tsunekane M. , Taira T.
Published: April 2013

A compact passively Q-switched Nd:YAG/Cr4+:YAG laser that uses a volume Bragg gratings optical element as output coupler was build and characterized. The laser operated on a limited range of temperature when the pump pulse energy was constant.
Efficiency, energy, and power scaling of diode-pumped, short-pulse laser amplifiers using Yb-doped gain media
Authors: Siebold M. , Loeser M. , Koerner J. , Wolf M. , Hein J. , Wandt C. , Klingebiel S. , Karsch S. , Schramm U.
Published: April 2013

We present a novel approach to overcome efficiency limitations of nanosecond lasers based on Yb-doped materials. Furthermore, we introduce a combination of bulk and thin-disk design for power scaling of diode-pumped lasers.
Design of high average power mode-locked oscillator based on edge-pumped all ceramic Yb:YAG/YAG microchip
Authors: Sugita Atsushi , Matsushita Tomonori , Taira Takunori
Published: April 2013

We report the first high-power mode-locked ceramic laser in Yb:YAG/YAG composite microchip. The primal result of 1.0 μJ-pulse energy for 21W-average power was successfully obtained. The future issue of power-scalability and downsizing was also discussed.
Intracavity Synthetic Diamond: Underpinning Wavelength Diversity in Semiconductor Disk Lasers
Authors: Kemp Alan J. , Maclean Alexander J. , Millar Patricia , Hopkins John-Mark , Hastie Jennifer E. , Calvez Stephane , Dawson Martin D. , Burns David
Published: April 2013

Semiconductor disk lasers are diode-pumped solid-state lasers offering broad spectral coverage. An approach to thermal management that is similarly adaptable is thus required: finite element analysis shows that intracavity diamond heatspreaders are such an approach.
Oscillator Pulse Train with Constant Carrier-Envelope-Offset Phase and 65 Attosecond CE Jitter
Authors: Rausch Stefan , Binhammer Thomas , Harth Anne , Morgner Uwe
Published: April 2013

We present an octave-spanning Ti:sapphire laser oscillator stabilized to carrier-envelope-offset frequency zero, generating a pulse train with constant CE-phase and 65 attosecond jitter. The stabilization is realized using a modified f-to-2f-interferometer and phase-coherent locking.
Fully Phase and Amplitude-Locked Multicolor Coherent Pulse Synthesis from a fs Yb:KGW-Driven IR-OPA
Authors: Andriukaitis G. , Mücke O.D. , Verhoef A.J. , Pugžlys A. , Baltuška A. , Mikalauskas D. , Giniūnas L. , Danielius R.
Published: April 2013

Combining active CEP-locking of an Yb-DPSS amplifier with a passive CEP-lock on the idler, we demonstrate a 40-kHz 10-µJ OPA with a shot-to-shot-stable coherent superposition of the signal, idler and pump pulses and their harmonics.
CW Crystalline Raman Lasers: Multi-Watt and Multi-Wavelength Operation in the Visible
Authors: Pask Helen M. , Lee Andrew J. , Spence David J. , Piper James A.
Published: April 2013

We report the generation of high power, continuous-wave yellow emission from a frequency-doubled, self-Raman laser. Output power of 2.25 W at 586.5 nm is achieved with a diode to yellow conversion efficiency of 13.2%.
High power picosecond mid-infrared and visible source based on degenerated four-wave-mixing in a large mode area photonic crystal fiber
Authors: Nodop D. , Jauregui C. , Schimpf D. , Steinmetz A. , Limpert J. , Tünnermann A.
Published: April 2013

The unique properties of a 10µm endlessly-single-mode LMA PCF allowed for the efficient conversion of a 8W @ 1MHz fiber amplified 200ps, 1064nm microchip laser to 3W @ 673nm and 450mW @ 2.539µm by degenerated FWM. Scaling potential as well as tuneability options are supported by numerical simulations and will be discussed in detail.
Ultra-Broadband (> 500 nm) Single-Walled Carbon Nanotube Saturable Absorber Mode-Locking of Bulk Solid-State Lasers
Authors: Cho Won Bae , Yim Jong Hyuk , Choi Sun Young , Lee Soonil , Yeom Dong-Il , Kim Kihong , Rotermund Fabian , Schmidt Andreas , Steinmeyer Günter , Petrov Valentin , Griebner Uwe
Published: April 2013

Femtosecond mode-locking of Yb:KYW at 1.04 μm, Cr:forsterite at 1.25 μm and a Cr:YAG at 1.50 μm lasers using one and the same transmission-type single-walled carbon nanotube saturable absorber is demonstrated.
Picosecond Fiber Source for Coherent Raman Microscopy
Authors: Kieu Khanh , Saar Brian G. , Holtom Gary R. , Xie Sunney X. , Wise Frank W.
Published: April 2013

We report a high power picosecond fiber laser system for coherent Raman microscopy (CRM). The laser system was used to pump an optical parametric oscillator to produce the pump and the Stokes beams for CRM.
Military Imaging System Performance
Authors: Krapels Keith
Published: April 2013

Article not available.
Imaging at DARPA MTO
Authors: Dhar Nibir
Published: April 2013

Article not available.
Static architecture for compressive motion detection in persistent, pervasive surveillance applications
Authors: Stenner M.D. , Townsend D.J. , Gehm M.E.
Published: April 2013

High-resolution, wide-field-of-view airborne imaging produces large optical systems and data streams. Significant simplification is possible if motion detection, rather than full imaging, is the goal. We consider a static, compressive-sensing architecture for this problem.
Lens Aberration Correction Using Locally Optimal Mask Based Low Cost Light Field Cameras
Authors: Pandharkar Rohit , Kirmani Ahmed , Raskar Ramesh
Published: April 2013

We present a technique for effective lens aberration correction using a low cost mask based light field camera that uses locally optimal masks. Present physical methods for lens aberration corrections require complicated hardware installations on the cameras. Lens aberration correction in software without active optics is an ill-posed problem since the open lens blur causes frequency information loss. We present an extremely low cost modification in the camera by inserting a plastic transparency based mask which converts the ill-posed de blurring problem into a well-posed one allowing efficient de blurring of the lens aberration blur. We use a theoretical field curvature aberration model for designing the optimal transparency masks which are locally optimal. We perform the MSE analysis for our lens aberration correction technique and show that its performance is up to 35 db better than the standard software based correction techniques. We present the hardware built, theoretical model, and synthetic results for aberration correction.
Towards photon counting X-ray image sensors
Authors: Dierickx B. , Dupont B. , Defernez A. , Henckes P.
Published: April 2013

The advantages of photon counting over charge integration, for medical X-ray imaging, are known. Yet the realization is hindered by technical and economical factors. The question that we try to answer is: what does it take to make a photon counting X-ray sensor? ©2010 Optical Society of America
Coded Strobing Photography for High-Speed Periodic Events
Authors: Reddy Dikpal , Veeraraghavan Ashok , Raskar Ramesh
Published: April 2013

We capture high-speed periodic events using a low-frame rate camera by temporally modulating the shutter (coded strobing) and demonstrate that the Nyquist rate constraint can be imposed on strobe-rate rather than the sensor-rate.
Computational Photography
Authors: Raskar Ramesh
Published: April 2013

Article not available.
On Recent Progress Using QCLs for Molecular Trace Gas Detection - from Basic Research to Industrial Applications
Authors: Roepcke Juergen , Davies Paul , Hempel Frank , Huebner Marko , Glitsch Sven , Lang Norbert , Naegele Markus , Rousseau Antoine , Wege Stephan , Welzel Stefan
Published: April 2013

Quantum Cascade Lasers offer attractive options for applications of MIR absorption spectroscopy for basic research and industrial process control. The contribution reviews applications for plasma diagnostics and trace gas monitoring in research and industry.
Spectroscopic Applications of External Cavity Quantum Cascade Laser with Fast Tuning
Authors: Tsai Tracy , Wysocki Gerard
Published: April 2013

Littrow-based folded external cavity QCL capable of tuning up to 7cm−1 at kHz rates is presented. Laser capabilities in pulsed and cw modes are demonstrated by performing absorption spectroscopy of ammonia and ethylene at ~10μm.
Atmospheric Propagation and LIDAR Modeling of LITE Remote Sensing of Distant Compounds
Authors: Plutov Denis V. , Killinger Dennis K.
Published: April 2013

Atmospheric propagation simulations of Stand-off Laser-Induced-Thermal-Emission spectroscopy (Stand-off LITE) have been carried out taking into account molecular and aerosol attenuation of the atmosphere and a modified lidar equation.
Improved Wavelength Tuning of CW Optical Parametric Oscillators
Authors: Vainio Markku , Siltanen Mikael , Peltola Jari , Halonen Lauri
Published: April 2013

We discuss a new method for controlled wavelength tuning of cw singly resonant optical parametric oscillators. The method uses a grating for fast and broad wavelength scanning.
Gas Diagnostics by Laser-Induced Breakdown Spectroscopy Employing Polarization Filtering
Authors: Kiefer J. , Tröger J. W. , Seeger T. , Leipertz A. , Li B. , Li Z. S. , Aldén M.
Published: April 2013

In this work we present a setup for laser-induced breakdown spectroscopy (LIBS) employing a polarization filtering approach and use it for gas diagnostics. A one parts-per-million (ppm) detection sensitivity is achieved for hydrogen atoms.
Single and Dual Pulse LIBS and its Application to Metal Detection in Coastal Estuarine Ecosystems
Authors: Branch J. , Martinez J. , Akpovo C. , Jagoe C. , Johnson E. , Johnson L.
Published: April 2013

Oyster tissues and shells normally contain some trace elements, and can accumulate others as contaminants from food, water and sediments. These may pose risks to consumers or affect shellfish health and growth. Dual pulse Laser Induced Breakdown Spectroscopy (LIBS) can be used to examine trace elements and their ionic forms in different environmental samples. A rapid-pulse Nd:YAG laser was used to ablate a small amount of sample to obtain emission spectra from the resulting plasma. We also measured metal concentrations in the same samples by conventional acid-digestion graphite furnace AA (GFAA). LIBS may provide an extremely rapid, inexpensive and sensitive method for sample screening. LIBS also allows mapping of metal distributions along tissue transects, and so may have applications in growth or geochronology studies and modification of the method may facilitate lower detection limits.
Mid Infrared Tunable Diode Laser spectrometer for sensitive detection of acetylene
Authors: Lundqvist Stefan , Kluczynski Pawel
Published: April 2013

A Mid Infrared Tunable Diode Laser spectrometer utilizing Wavelength Modulation Spectroscopy for sensitive detection of acetylene has been designed. A sensitivity of 18 ppb m at an integration time of 3 seconds was achieved.
Frequency-Dependent Lower-State Energy: A New Spectroscopic Parameter Useful for Designing Laser-Based Thermometers
Authors: An Xinliang , Caswell Andrew W. , Sanders Scott T.
Published: April 2013

A spectroscopic transition’s temperature sensitivity is characterized by its lower-state energy. Here, we define a related parameter that is not fundamental but is a continuous function of frequency and applies to broadened and blended spectra.
Terahertz Time Domain Spectroscopy for Nondestructive Testing and Sensing Applications
Authors: Ellrich F. , Herrmann M. , Jonuscheit J. , Theuer M. , Torosyan G. , Molter D. , Wiegand S. , Wohnsiedler S. , Beigang R.
Published: April 2013

Terahertz spectroscopy and imaging using innovative photonic THz sources and detectors have turned out to be very useful techniques for applications in nondestructive testing and sensing. Typical examples of THz imaging and spectroscopy are presented.
Slits, curves, chains and rings: how to mix the right ingredients for surface-emitting THz quantum cascade lasers
Authors: Tredicucci Alessandro
Published: April 2013

Mechanisms and structures to achieve surface emission in terahertz quantum cascade lasers are discussed. The necessary symmetry breaking is produced in gratings with a base, or curved, or quasiperiodic, and by the finite device length.
Application of Mid-IR Laser Spectroscopy for the Analysis of Surgical Smoke
Authors: Gianella Michele , Sigrist Markus W.
Published: April 2013

The composition of surgical smoke was quantitatively analyzed by employing infrared laser spectroscopy. In vitro and in vivo samples were compared. In addition to smoke components, the anesthetic sevoflurane was identified in samples from laparoscopy.
Ultra high framing-rate laser diagnostics for high-speed reacting and non-reacting flows
Authors: Jiang Naibo , Webster Matthew C. , Gabet Kathryn N. , Patton Randy L. , Adamovich Igor , Sutton Jeffrey A. , Lempert Walter R. , Miller Joseph D. , Meyer Terrence R. , Inman Jenifer A. , Bathel Brett , Jones Steve B. , Danehy Paul M.
Published: April 2013

The critical features of a burst mode diagnostic imaging system is described, along with representative NO PLIF measurements at 1MHz, in a Mach 10 hypersonic flow, and Rayleigh imaging at 10kHz in a turbulent flame.
Phosphor thermometry at an optically accessible internal combustion engine
Authors: Brübach J. , Kissel T. , Dreizler A.
Published: April 2013

Two-dimensional phosphor thermometry based on the temperature-dependent luminescence lifetime using a CMOS high-speed camera was characterized and applied to an optically accessible Diesel engine. A temperature transient was monitored in trailed and in fired operation.
Fiber Lasers as a Source for Laser –Induced Incandescence in Practical Applications
Authors: Black John D.
Published: April 2013

Laser-induced incandescence (LII) using a fiber laser has been demonstrated in an engine exhaust and ambient air. There are advantages over Nd/YAG lasers in practical applications, but a new model for long pulse LII is required.
Photonic Microring-Chip-Sensor for Explosive Detection
Authors: Orghici Rozalia , Lützow Peter , Burgmeier Jörg , Schade Wolfgang , Welschoff Nina , Waldvogel Siegfried
Published: April 2013

A microring resonator sensor for selective and sensitive detection of the explosive TNT (trinitrotoluene) is discussed. The combination of integrated optics and specially developed receptor molecules is used for this optical sensing.
Mapping coastal wetlands using small-footprint, green-wavelength lidar
Authors: Nayegandhi Amar
Published: April 2013

Airborne lidar technology has broad applications in vegetation-structure mapping within coastal environments. However, several challenges still exist in mapping wetland topography where the elevation changes are slight and the vegetation cover varies from short grasses to dense marshlands to thick shrubs.
Holographic sensors for environmental monitoring
Authors: Naydenova I. , Mintova S. , Martin S. , Toal V.
Published: April 2013

The properties of holographic sensors for environmental monitoring fabricated in zeolite doped photopolymerisable nanocomposites have been studied. The sensors based on volume transmission holograms have been theoretically modelled and their sensitivity has been discussed.
Retrieval of cloud properties using a principal component based physical methodology
Authors: Wu Wan , Liu Xu , Zhou Daniel K. , Larar Allen M.
Published: April 2013

We present here the study of cloud top height and microphysical properties retrievals from the Infrared Atmospheric Sounding Interferometer (IASI) simulation radiance data using the PCRTM physical inversion algorithm.
Maximizing the Efficiency Cost Ratio in a CPV System via a Tolerant Optical Design
Authors: Miñano Juan C. , Benítez Pablo , Zamora Pablo , Mohedano Rubén , Cvetkovic Aleksandra , Buljan Marina , Chaves Julio , Alvarez Roberto
Published: April 2013

An advanced CPV concentrator with a Fresnel primary and a refractive secondary produces both high concentration with high tolerance and an excellent light homogenization. It compares well with conventional Fresnel-based CPV from both optical and cost standpoints.
A 5kW CPV collector design using an inflated plastic film primary mirror
Authors: Baldwin Leo
Published: April 2013

Cool Earth Solar is designing a utility-scale concentrated solar photovoltaic generating system using inflated reflective polyester teraphthalate film as the primary concentrator to achieve the combined objectives of low installed cost per watt and low cost per kWh. The shape of the film is a consequence of the properties of the film and the inflation pressure. The optical properties of the film are characterized and an appropriate receiver designed. The receiver is a monolithic multiple-channel design incorporating a compound secondary concentrator and a mosaic of solar cells chosen to best exploit the properties of the primary. The primary concentrator is profiled using a specially designed test set-up and software. The secondary-optic design is optimized using commercial non-sequential ray-tracing software with multi-variable optimization. The secondary optic design dictates the layout of the solar cell mosaic.
Measurement of sun-tracking accuracy and solar irradiance through multispectral imaging
Authors: Vincenzi Donato , Baricordi Stefano , Occhiali Massimiliano , Stefancich Marco , Parretta Antonio , Martinelli Giuliano
Published: April 2013

We present the design guidelines and the characterization of a multispectral camera tailored to be used as accuracy measurement device for sun trackers. The camera has been calibrated for direct normal irradiance measurements.
Reduced Temperature of Holographic Planar Concentrators
Authors: Castillo Jose E. , Russo Juan M. , Herr-Cardillo Starr , Kumar Rakesh , Rosenberg Glenn A.
Published: April 2013

We present the temperature data for several examples of holographic planar concentrators. The extended holographic regions act as radiative transfer surfaces which reduce the temperature of the cells used with the concentrating film.
2D blazed grating for light trapping in thin silicon solar cells
Authors: Gjessing Jo , Sudbø Aasmund , Marstein Erik Stensrud
Published: April 2013

We propose a novel sub-micron back-side grating for light trapping in thin silicon solar cells. The 2D-blazed grating has the potential to increase the optical thickness of the solar cell by a factor of 17.
A Scattering Model for Transparent Thin Films with Surface Textures
Authors: Jaeger Klaus , Zeman Miro
Published: April 2013

Scattering properties of surface-textured thin films that are used in thin-film silicon solar cells, such as angular intensity distribution and haze, were calculated with the scalar scattering theory. Good agreement with measured data was achieved.
Theory of the “Inverse Method” for Characterization of Solar Concentrators
Authors: Parretta A. , Roncati D.
Published: April 2013

The theory of “inverse method” applied to the optical characterization of solar concentrators is revisited. New optical quantities are introduced and the experimental procedure for measuring the on-axis absolute “direct” transmission efficiency is reported.
Optical Biasing Effects on Multijunction Solar Cells
Authors: Lim S. H. , O’Brien K. , Steenbergen E. H. , Zhang Y.–H.
Published: April 2013

We analyze and demonstrate the electrical and optical characterization techniques for multijunction solar cells to explain and quantify measurement artifacts commonly encountered under practical test conditions.
Randomly textured surfaces for photon management in silicon thin film solar cells
Authors: Rockstuhl Carsten , Fahr Stephan , Lederer Falk
Published: April 2013

Rigorous diffraction theory is used to reveal the peculiarities of randomly textured surfaces as used for photon management. The effect of such surfaces in solar cells with an increasing complexity is analyzed to provide unprecedented insights.
Commercial CIGS Solar Cells for Concentrator Applications
Authors: Zhang Deming , Castro Jose M , Kostuk Raymond K.
Published: April 2013

We studied the effect of concentration on commercial CIGS solar cells. Measurement results indicate 23% improvement in efficiency can be achieved under 20X. Methods to optimize concentrator cells for higher irradiance levels are also discussed.
Environmental Impacts of Distributed Manufacturing from 3-D Printing of Polymer Components and Products
Authors: Kreiger Megan , Pearce Joshua M.
Published: April 2013

Although additive layer manufacturing is well established for rapid prototyping the low throughput and historic costs have prevented mass-scale adoption. The recent development of the RepRap, an open source self-replicating rapid prototyper, has made low-cost 3-D printers readily available to the public at reasonable prices (<$1,000). The RepRap (Prusa Mendell variant) currently prints 3-D objects in a 200x200x140 square millimeters build envelope from acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). ABS and PLA are both thermoplastics that can be injection-molded, each with their own benefits, as ABS is rigid and durable, while PLA is plant-based and can be recycled and composted. The melting temperature of ABS and PLA enable use in low-cost 3-D printers, as these temperature are low enough to use in melt extrusion in the home, while high enough for prints to retain their shape at average use temperatures. Using 3-D printers to manufacture provides the ability to both change the fill composition by printing voids and fabricate shapes that are impossible to make using tradition methods like injection molding. This allows more complicated shapes to be created while using less material, which could reduce environmental impact.

As the open source 3-D printers continue to evolve and improve in both cost and performance, the potential for economically-viable distributed manufacturing of products increases. Thus, products and components could be customized and printed on-site by individual consumers as needed, reversing the historical trend towards centrally mass-manufactured and shipped products. Distributed manufacturing reduces embodied transportation energy from the distribution of conventional centralized manufacturing, but questions remain concerning the potential for increases in the overall embodied energy of the manufacturing due to reduction in scale. In order to quantify the environmental impact of distributed manufacturing using 3-D printers, a life cycle analysis was performed on a plastic juicer. The energy consumed and emissions produced from conventional large-scale production overseas are compared to experimental measurements on a RepRap producing identical products with ABS and PLA. The results of this LCA are discussed in relation to the environmental impact of distributed manufacturing with 3-D printers and polymer selection for 3-D printing to reduce this impact. The results of this study show that distributed manufacturing uses less energy than conventional manufacturing due to the RepRap's unique ability to reduce fill composition. Distributed manufacturing also has less emissions than conventional manufacturing when using PLA and when using ABS with solar photovoltaic power. The results of this study indicate that open-source additive layer distributed manufacturing is both technically viable and beneficial from an ecological perspective.