bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Prereferral Surgery in Soft Tissue Sarcoma: 10 Years’ Experience in a Single Institution
Authors: Zacherl Maximilian , Kastner Norbert , Glehr Matthias , Scheipl Susanne , Schwantzer Gerold , Koch Horst , Leithner Andreas , Windhager Reinhard
Published: August 2012

Soft tissue sarcomas are a group of rare mesenchymal neoplasms comprising 0.8% of all malignant tumors. Workup should include medical history, physical examination, magnetic resonance imaging, biopsy, and thoracoabdominal computed tomography scan, in that order. Centralized multimodality treatment in a cross-disciplinary setting is mandatory. Treatment not according to current clinical practice guidelines is a common problem before referral to a specialized institution. The purpose of this 10-year, single-institution review was to investigate the influence of curative surgery on outcome, with a special emphasis on surgery before referral.

A cohort of 266 patients who underwent curative surgery for soft tissue sarcoma between 1998 and 2008 was analyzed. One hundred thirty-one (49%) patients underwent surgery contrary to current clinical guidelines before referral, most (73%) at primary care units. One hundred thirteen (86%) of these patients underwent surgery without previous biopsy with a higher rate of intralesional margins (
P
<.001), a smaller mean diameter of primary lesion (
P
<.001), a higher rate of subcutaneous situs (
P
<.001), a lower mean American Joint Committee on Cancer score (
P
=.008), a higher rate of additional plastic surgery after re-resection (eg, flap surgery) (
P
<.001), and a longer period before referral (
P
<.001). No influence on survival, local recurrence, or metastasis existed.

Prereferral surgery necessitating re-resection has no influence on survival but leads to an unfavorable clinical course. More effort should be made to improve awareness and referral modalities for general practitioners and physicians at community hospitals.
Analysis of CT-based Navigation System for Pedicle Screw Placement
Authors: Hodges Scott D. , Eck Jason C. , Newton Danette
Published: August 2012

The incidence of pedicle screw breech varies based on anatomic location, body habitus, surgeon experience, spinal deformity, and surgical technique. Pedicle breeches have been reported to occur in up to 40% of screws. The purpose of this retrospective study was to compare the rates of revision of pedicle screw placement when using intraoperative C-arm vs O-arm (Medtronic, Memphis, Tennessee) assessment of pedicle screws. An economic analysis was also performed based on the estimated cost of pedicle screw revision.

Four (1%) of 386 control patients required pedicle screw revision for a breeched pedicle screw not identified with intraoperative C-arm fluoroscopy. In the study group, none of the 331 patients returned to the operating room when O-arm was used to assess pedicle screw placement. Based on the 1% rate of returning to the operating room in the control group, the annual rate of cases nationwide requiring pedicle screw revision would be approximately 2300, with a cost of approximately $40,595,000.

These results suggest that the use of intraoperative O-arm can reduce the need for revision of a breeched pedicle screw. This can potentially lead to a major cost savings.
Sandwich Vertebral Fracture in the Study of Adjacent-level Fracture After Vertebral Cement Augmentation
Authors: Wang Lijun , Yang Huilin , Shi Yuanxin , Luo Zongping , Jiang Weimin , Bao Zhaohua , Chen Kangwu , Wang Genlin
Published: August 2012

The literature is inconclusive on the development of adjacent-level vertebral fracture after initial cement augmentation. A preliminary hypotheses is that cement injection exaggerates force transmission to the adjacent vertebral bodies, thereby predisposing those levels to future fractures. A sandwich vertebra is an intact vertebral body located between 2 previously cemented vertebrae. The purpose of this study was to determine whether the risk of adjacent-level fracture increased due to load shift after a cement injection procedure. The authors retrospectively investigated the rate of adjacent-level fracture after sandwiching compared with conservative treatment and determined the potential causative factors of sandwich vertebral fracture. Age, sex, weight, height, body mass index, follow-up period, and location of sandwich level (T10-L2 or nonT10-L2 junction) were assessed. Surgical variables, including surgical procedure (vertebroplasty or balloon kyphoplasty), surgical approach (through uni- or bilateral pedicle), volume of cement injected into the painful vertebrae, cement leakage into the intervertebral disk, cumulative number of treated levels, and pre- and postoperative kyphotic angulation of the sandwich region, were also analyzed. Nine of 42 sandwiched levels developed fatigue fractures, whereas 11 of 71 patients treated with conservative therapy sustained new vertebral fractures adjacent to the treated levels. Only preoperative kyphotic angulation was the variable positively associated with sandwich vertebral fracture at follow-up (
P
=.021). Although subjected to double load shifts, the sandwich vertebra was not prone to structural failure. Thus, cement augmentation protocol does not increase the incidence of adjacent vertebral fracture.
Surgical Strategy for Ossification of the Posterior Longitudinal Ligament in the Cervical Spine
Authors: Chen Yu , Liu Xiaowei , Chen Deyu , Wang Xinwei , Yuan Wen
Published: August 2012

Ossification of the posterior longitudinal ligament is a common cause of cervical myelopathy, and controversy remains regarding surgical options. Between January 2004 and December 2007, a total of 164 patients with ossification of the posterior longitudinal ligament in the cervical spine who underwent surgical treatment at the authors’ institution were included in this study. The choice of surgical option was based on pathological extent and cervical alignment. Short-segment pathology was treated via the anterior approach and long-segment pathology via the posterior approach. When the posterior approach was selected, laminoplasty was performed for the patients with cervical lordosis and laminectomy with fusion for those with cervical kyphosis. Consequently, anterior corpectomy and fusion was performed in 91 patients, laminoplasty in 41 patients, and laminectomy and instrumented fusion in 32 patients. The Japanese Orthopedic Association scoring system was used to evaluate patients’ neurological status, and related complications were also recorded. Clinical results between different approaches and techniques were compared at mid-term follow-up.

Based on the results of this study and a review of previous literature, no significant differences existed between different approaches and techniques for patients with mild ossification of the posterior longitudinal ligament, but anterior corpectomy and fusion had significantly better results in patients with severe ossification of the posterior longitudinal ligament. With respect to the posterior approach, laminectomy and instrumented fusion improved the surgical results of patients with cervical kyphosis, but a high incidence of C5 palsy existed simultaneously.
Effects of Interleukin-1 Receptor Antagonist on Collagen and Matrix Metalloproteinases in Stress-shielded Achilles Tendons of Rats
Authors: Ma Yanhong , Yan Xiaoyan , Zhao Huakun , Wang Wei
Published: August 2012

Based on previous studies showing that interleukin-1 (IL-1) significantly increased after stress shielding, this article reports further research into the possible therapeutic applications of IL-1 receptor antagonist (IL-1Ra).

Forty rats whose left Achilles tendons were denervated and completely stress shielded were divided into 5 groups: 2-week phosphate-buffered saline (PBS); 4-week PBS; 2-week IL-1Ra; 4-week IL-1Ra; and normal control. The Achilles tendons were tested morphologically, and the changes in collagen I and III, matrix metalloproteinases (MMP)-1 and -3, and tissue inhibitors of metalloproteinase (TIMP)-1 were determined. The collagen fibrils in the IL-1Ra groups were morphologically more similar to those in the control group than to those in the PBS groups. The collagen I levels increased in the 2-week groups. Significant differences existed between the PBS and IL-1Ra groups at 4 weeks. The MMP-1 level increased dramatically after stress shielding and increased less in the 2-week IL-1Ra group than in the 2-week PBS group. The degree of decrease of MMP-3 in the IL-1Ra groups was significantly less than that in the PBS groups. The collagen III and TIMP-1 levels continued to increase, and no difference was found between the PBS and IL-1Ra groups. Interleukin-1 receptor antagonist prevented morphological deterioration and collagen metabolism of the denervated Achilles tendons after stress shielding, likely by inhibiting the decline of MMP-3 and increasing MMP-1 levels at an early stage.
Cuff Width Increases the Serum Biochemical Markers of Tourniquet-induced Skeletal Muscle Ischemia in Rabbits
Authors: Chalidis Byron E. , Kalivas Efstathios , Parziali Marina , Christodoulou Anastasios G. , Dimitriou Christos G.
Published: August 2012

Tourniquet application is a widely accepted adjuvant technique in extremity surgery. The purpose of this prospective, randomized trial was to evaluate the effect of cuff width on skeletal muscle ischemia-reperfusion injury. A 2- or 4-cm wide curved tourniquet cuff was applied around the midthigh of 36 New Zealand White rabbits and inflated to a pressure of 200 or 400 mm Hg for 2 hours: group A=2 cm to 200 mm Hg; group B=2 cm to 400 mm Hg; group C=4 cm to 200 mm Hg; group D=4 cm to 400 mm Hg. Blood levels of potassium, lactic acid, urea, lactic dehydrogenase, and creatinine phosphokinase MM isoenzyme (CPK-MM) were measured as basic indicators for limb ischemia before tourniquet inflation and 1, 5, and 30 minutes after cuff release.

Potassium values did not differ among the 4 groups. Lactic acid and urea concentrations were always higher in the 400 mm Hg groups (B and D) (
P
<.001). However, cuff width did not affect their levels (
P
>.16). Lactic dehydrogenase and CPK-MM values were also greater in the 400 mm Hg groups at all times (
P
<.001). Further subgroup analysis of 200 mm Hg pressure groups showed higher lactic dehydrogenase (
P
<.02) but not CPK-MM (
P
>.9) concentrations in group C than in group A during the 30-minute period. At 400 mm Hg, lactic dehydrogenase and CPK-MM values were higher in group D compared with group B only 30 minutes after cuff deflation (
P
<.001).

Broad tourniquets are associated with significantly greater and prolonged elevation of serum biochemical markers of inducible skeletal muscle ischemia-reperfusion injury compared with narrow ones. This difference is more prominent when a wide cuff is inflated to a high pressure.
Extra-articular Synovial Fluid Extravasation Following Operative Fixation of an Osteochondral Fracture of the Patella
Authors: Marberry Kevin M. , Ginsburg Zach
Published: August 2012

Osteochondral fracture of the patella following a lateral patellar dislocation can be treated with operative and nonoperative techniques that are dictated by the clinical presentation. In the presence of large fragments following acute fractures, arthroscopic retrieval and fixation are advocated, whereas smaller displaced fragments may be removed and discarded as loose bodies. Several methods of fixation exist for osteochondral fractures of the patella, including the use of cannulated and noncannulated screws.

This article describes a case of an elite competitive swimmer who sustained a lateral patellar dislocation with a large osteochondral fracture of the patella that was treated with open reduction and fixation using absorbable cannulated screws in an inside-out fashion. In the early postoperative period, the patient developed a symptomatic synovial fluid fistula through a cannulated screw to the prepatellar space. The diagnosis of this condition was made clinically and confirmed with noncontrast magnetic resonance imaging 6 weeks postoperatively. The symptoms of pain, skin erythema, and swelling were self-limited and eventually resolved with observation, allowing the athlete to return to his previous activity level. Magnetic resonance imaging 3 years postoperatively showed the complete resolution of the fluid extravasation.

Extra-articular synovial fluid extravasation is as a rare complication following routine knee arthroscopy, accounting for 3.2% of the complications. This article describes a rare, self-limited complication following open fixation of an osteochondral fracture of the patella.
Isolated Tear of the Pectoralis Minor Tendon in a High School Football Player
Authors: Li Xinning , Gorman Matthew T. , Dines Joshua S. , Limpisvasti Orr
Published: August 2012

Multiple pectoralis major tendon tears have been reported in the literature; however, isolated rupture of the pectoralis minor tendon is rare and has been reported 3 times (4 patients).

This article describes a case of an isolated pectoralis minor tendon tear in a male high school football player after a traumatic injury. The patient was injured while making a tackle and leading with his arm and chest. He presented with left anterior shoulder and chest wall pain with direct tenderness on palpation over the coracoid. Magnetic resonance imaging of the chest revealed an isolated tear of the pectoralis minor tendon with slight retraction and significant edema in the muscle belly. The patient returned to full activities after conservative management.

Although rare, the diagnosis of pectoralis minor tendon rupture should be considered in patients who sustain a contact injury to the shoulder with tenderness on palpation over the coracoid. The mechanism of injury can be related to a direct anterior force to the shoulder, forced external rotation of the arm in slight abduction, or with the arm in extension and shoulder in flexion (eg, blocking in football). The diagnosis can be confirmed with magnetic resonance imaging when edema exists on the medial aspect of the coracoid and extends into the muscle belly. Physical therapy with scapular stabilization exercises and avoidance of abduction and active adduction can be successful in returning these patients to their previous activity levels.
Effect of Nd:YAG Laser Capsulotomy on Refraction in Multifocal Apodized Diffractive Pseudophakia
Authors: Vrijman Violette , van der Linden Jan Willem , Nieuwendaal Carla P. , van der Meulen Ivanka J.E. , Mourits Maarten P. , Lapid-Gortzak Ruth
Published: August 2012

PURPOSE:

To evaluate the effect on refraction of neodymium:YAG (Nd:YAG) laser posterior capsulotomy for posterior capsule opacification (PCO), and to evaluate the correlation between automated and subjective refraction in multifocal apodized diffractive pseudophakia.

METHODS:

A retrospective study of 75 pseudophakic eyes (50 patients) with multifocal apodized diffractive pseudophakia, treated for PCO with Nd:YAG laser posterior capsulotomy, was performed. Pre- and postintervention values of refractive and visual parameters were compared. The outcomes of autorefraction and subjective refraction were also compared.

RESULTS:

Uncorrected and corrected distance visual acuity improved significantly after Nd:YAG capsulotomy (
P<
.001). No significant changes were noted in defocus equivalent, astigmatic power vectors J
0
and J
45
, and overall blurring strength in subjective refraction and autorefraction. Spherical equivalent changed significantly in autorefraction (
P
=.008), but not in subjective refraction. Autorefraction and subjective refraction were highly correlated in spherical equivalent, defocus equivalent, and blurring strength (r
2
>0.59). In approximately 7% of eyes, a change of more than 0.50 diopters in spherical equivalent in subjective refraction occurred.

CONCLUSIONS:

In most cases, Nd:YAG laser capsulotomy in patients with multifocal pseudophakia did not result in a change in refraction. However, 7% of eyes experienced a significant change in subjective refraction. Autorefraction correlated well with subjective refraction in apodized diffractive multifocal IOLs.
Effect of Combined Topical Heparin and Steroid on Corneal Neovascularization in Children
Authors: Michels Rike , Michels Stephan , Kaminski Stephan
Published: August 2012

BACKGROUND AND OBJECTIVE:

To demonstrate the effect of topical heparin combined with topical steroid on corneal neovascularization (CN) in children.

PATIENTS AND METHODS:

Four children (5 eyes) with new-onset progressive CN in at least one eye received topical rimexolone or dexamethasone in combination with heparin until complete regression of CN was obtained. The regression of CN was documented by slit-lamp or anterior segment photography.

RESULTS:

All 5 eyes showed complete regression of CN within 5 months. An anti-angiogenic effect was found as early as 1 week after starting topical combination treatment. No ocular and systemic side effects were detected and treatment was well tolerated by all children. In the 3 eyes with involvement of the optical axis, symmetrical visual acuity was obtained by amblyopia treatment. Recurrence of the CN was detectable in 2 eyes at 1 and 6 months, respectively, after ending combination therapy. Both eyes responded favorably to re-treatment.

CONCLUSION:

Combination of topical heparin and steroid leads to rapid regression and complete inactivity of CN. This therapeutic approach is promising, especially in children with limited therapeutic alternatives and a high risk for amblyopia.
Comparison of Postoperative Refractive Outcomes: IOLMaster
®
Versus Immersion Ultrasound
Authors: Whang Woong-Joo , Jung Byung-Ju , Oh Tae-Hoon , Byun Yong-Soo , Joo Choun-Ki
Published: August 2012

BACKGROUND AND OBJECTIVE:

To compare the postoperative refractive outcomes between IOLMaster biometry (Carl Zeiss Meditec, Inc., Dublin, CA) and immersion ultrasound biometry for axial length measurements.

PATIENTS AND METHODS:

Refractive outcomes in 354 eyes were compared using the IOLMaster and the immersion ultrasound biometry. Predicted refraction was determined using manual keratometry and the SRK-T formula with personalized A-constant.

RESULTS:

The axial lengths measured using the IOLMaster and immersion ultrasound were 24.49 ± 2.11 and 24.46 ± 2.11 mm, respectively, and the difference was significant (
P
< .05). The mean errors were 0.000 ± 0.578 D with the IOLMaster, and 0.000 ± 0.599 D with the immersion ultrasound, but the difference was not significant. The mean absolute error was smaller with the IOLMaster than with immersion ultrasound (0.463 ± 0.341 vs 0.479 ± 0.359 D), but the difference was not significant.

CONCLUSION:

IOLMaster biometry yields highly accurate results in cataract surgery. However, if the IOLMaster is unavailable, immersion ultrasound biometry with personalized intraocular lens constants is an acceptable alternative.
Rationale for Performing Penetrating Keratoplasty Rather Than DSAEK in Patients With Bullous Keratopathy in Japan
Authors: Yokogawa Hideaki , Kobayashi Akira , Saito Yoshiaki , Yamazaki Natsuko , Masaki Toshinori , Sugiyama Kazuhisa
Published: August 2012

BACKGROUND AND OBJECTIVE:

To analyze the rationale for performing penetrating keratoplasty (PK) rather than Descemet’s stripping automated endothelial keratoplasty (DSAEK) in patients with bullous keratopathy (BK) in Japan.

PATIENTS AND METHODS:

A total of 136 eyes of 130 patients with consecutive BK were enrolled. Patients treated by DSAEK were categorized as the DSAEK group. The remaining patients were considered unsuitable for DSAEK due to the presence of risk factors, and were treated by PK (PK group). In both groups, the number of the patients and the causes of BK were analyzed. Also, specifically in the PK group, the reasons for not performing DSAEK were analyzed.

RESULTS:

The causes of BK differed significantly between the two groups (
P
< .001). Risk factors considered unsuitable for DSAEK include significant stromal scarring, iris abnormalities, and lens abnormalities.

CONCLUSION:

For successful DSAEK, risk factors and contraindications should be carefully evaluated before surgery.
Semi‐automated characterisation of seabed pockmarks in the central North Sea
Authors: Gafeira J. , Long D. , Diaz‐Doce D.
Published: August 2012

Pockmarks are indicators of focused fluid seepage, most notably gas such as methane, and can occur in vast numbers in many marine and even in lacustrine environments. The presence and distribution of pockmarks need to be considered in the development of any infrastructure at the seabed. However, manual mapping of these features can be extremely time‐consuming and it is implicitly subjective.

An extensive area in the central North Sea, where the seabed comprises a thick sequence of muds and sandy muds of the late glacial Witch Ground Formation, shows numerous inactive pockmarks, typically 20–100 m diameter and 3–4 m deep. Within this area a few larger, active pockmarks, 500 m diameter and up to 17 m deep are known. Modern site investigations in this area regularly include multibeam sonar mapping, a technique that collects large volumes of bathymetric data that can be used to produce digital depth models of the seafloor with sufficient resolution to characterize individual pockmarks.

This paper presents a semi‐automated method to recognize, spatially delineate and characterise morphometrically pockmarks at the seabed. The method comprises two scripts, Pockmark Mapping and Pockmark Characterization, that allow the systematic application of a sequence of well defined tools available within the ESRI ArcGIS toolbox. Almost 4150 pockmarks were mapped applying this method to 18 selected site surveys across the central North Sea. The mapping and morphometric characterization of such vast number of pockmarks allows the identification of certain trends reflecting the hydrodynamic regime, whereas the pockmarks density and spatial distribution appears to be attributable to differences in shallow gas availability and deeper geology controlling fluid migration pathways.
Contribution of high‐resolution 3D seismic near‐seafloor imaging to reservoir‐scale studies: application to the active North Anatolian Fault, Sea of Marmara
Authors: Thomas Y. , Marsset B. , Westbrook G.K. , Grail C. , Géli L. , Henry P. , Çifçi G. , Rochat A. , Saritas H.
Published: August 2012

High Resolution (HR) marine seismic acquisition contributes to numerous research fields. The vertical resolution is of metric scale in order to study geological processes at a short time scale or to characterise small objects. 3D seismic imaging allows optimal resolution to be reached whereas 2D images are blurred mainly by side effects. Developed for the oil industry decades ago and tailored to the exploration for hydrocarbon reservoirs, 3D seismic, as applied to higher resolution targets, is more recent. Available technological advances in acquisition have allowed research institutes to develop innovative 3D high‐resolution marine seismic systems tailored to these targets.

The seismic survey carried out in 2009 on the Western High, Sea of Marmara, illustrates the value of HR3D imaging. Since the destructive İzmit earthquake in 1999, an intensive international research effort has demonstrated that the Western High is one of the key structures for assessing the processes of deformation related to the North Anatolian Fault (NAF). The 30‐km2 HR3D survey centred on the main NAF was acquired using a dual streamers ‐ dual source‐array configuration. In spite of the minimal 3D processing sequence that was applied to the data, the fine imaging of the seabed and of the sedimentary stratigraphy and structures is much better than HR2D seismic. Comparison with an autonomous underwater vehicle (AUV) multi‐beam bathymetric survey carried out at the same location enables the limits of the vertical resolution of the seismic data to be assessed. The lateral resolution is between 13.5 and 25 metres at the seabed. The HR3D seismic data highlight the interplay between tectonic processes and stratigraphy. In particular, differential uplift leads to syntectonic deposition and submarine slides. The widespread occurrence of gas in the sedimentary sequence is clearly shown by anomalously high seismic amplitudes. 3D imaging of these high amplitudes enables the identification of the pathways through faults and permeable units that gas takes as it migrates to the seabed.
An ice‐ moulded surface from the middle Pleistocene of the Central North Sea
Authors: Buckley Francis
Published: August 2012

A collection of seismic datasets, including Ultra‐High Resolution 2D, High Resolution 2D and Exploration 3D data, have been compared with geotechnical borehole logs, to investigate a Middle to Late Pleistocene sequence within the Central North Sea (CNS). An Elsterian glacial erosion surface is interpreted to be overlain by a series of seismo‐stratigraphic formations which can mostly be referenced to the accepted stratigraphic model for the area, though with some significant qualifications. Evidence is shown for the presence of at least three grounded ice‐sheets within the Middle‐Late Pleistocene of the CNS, including a previously unreported, pre‐Weichselian, ice‐moulded and lineated surface. The late and post‐glacial history of the CNS is re‐constructed by reference to borehole lithological data, compared with seismic textures. It is proposed that a seismo‐stratigraphic unit at seabed and named in published sources as the late glacial Forth Fm. is much older, with implications for the prediction of geotechnical properties of the unit elsewhere in the region.
Surgical Techniques: Past, Present and Future
Authors: Qayumi Karim
Published: August 2012

The aim of this paper is to provide an analytical survey of the information available on the development of past and present surgical techniques, and to make projections for the future. For the purposes of this paper, the Past starts in the Neolithic period and ends in the 1800s. In this context, I have divided the Past into Prehistoric, Ancient and Middle Ages, and this period ends in the second half of the 19th century when the major obstacles to the further development of surgery, such as overcoming pain and infection, were removed. We will discuss the development of surgical techniques, and the obstacles and opportunities prevalent in these periods. In the context of this paper, the Present begins in 1867, when Louis Pasteur discovered microorganisms, and ends in the present day. There have been many important changes in the development of surgical techniques during this period, such as the transfer of surgery from the unsterile operating room to the modern hospital operating theater, the development of advanced and specialized surgical practices, such as transplants and laparoscopy, and minimally invasive surgical methods, robotic and Natural Orifice Transluminal Endoscopic Surgery. It is very difficult to foresee how surgical techniques will develop in the Future because of the unpredictable nature of technological progress. Therefore, in this paper, the forecast for the Future is limited to the next 50- 100 years and is a realistic calculation based on already existing technologies. In this context, the Future is divided into the development of surgical techniques that will develop in the near and distant future. It is anticipated that this overview will shed light on the historical perspective of surgical techniques and stimulate interest in their further development.
Identification and Quantification of Dimethylamylamine in Geranium by Liquid Chromatography Tandem Mass Spectrometry
Authors: Li J.S. , Chen M. , Li Z.C.
Published: August 2012

A sensitive and reliable method of liquid chromatography–electrospray ionization/tandem mass spectrometry (LC-ESI/MS/MS) was developed and validated for determining 1,3-dimethylamylamine (1,3-DMAA) and 1,4-dimethylamylamine (1,4-DMAA) in geranium plants ( Pelargonium graveolens). The sample was extracted with 0.5 M HCl and purified by liquid-liquid partition with hexane. The parameters for reverse-phase (C18) LC and positive ESI/MS/MS were optimized. The matrix effect, specificity, linearity, precision, accuracy and reproducibility of the method were determined and evaluated. The method was linear over a range of 0.10-10.00 ng/mL examined, with R 2 of 0.99 for both 1,3-DMAA and 1,4-DMAA. The recoveries from spiked concentrations between 5.00-40.00 ng/g were 85.1%-104.9% for 1,3-DMAA, with relative standard deviation (RSD) of 2.9%-11.0%, and 82.9%-101.8% for 1,4-DMAA, with RSD of 3.2%–-11.7%. The instrument detection limit was 1-2 pg for both DMAAs. The quantification limit was estimated to be 1-2 ng/g for the plant sample. This method was successfully applied to the quantitative determination of 1,3- and 1,4-DMAA in both geranium plant and geranium oil.
Characterization of aerosol and cloud water at a mountain site during WACS 2010: secondary organic aerosol formation through oxidative cloud processing
Authors: Lee A. K. Y. , Hayden K. L. , Herckes P. , Leaitch W. R. , Liggio J. , Macdonald A. M. , Abbatt J. P. D.
Published: August 2012

Abstract. The water-soluble fractions of aerosol filter samples and cloud water collected during the Whistler Aerosol and Cloud Study (WACS 2010) were analyzed using an Aerodyne aerosol mass spectrometer (AMS). This is the first study to report AMS organic spectra of re-aerosolized cloud water, and to make direct comparison between the AMS spectra of cloud water and aerosol samples collected at the same location. In general, the mass spectra of aerosol were very similar to those of less volatile cloud organics. By using a photochemical reactor to oxidize both aerosol filter extracts and cloud water, we find evidence that fragmentation of water-soluble organics in aerosol increases their volatility during photochemical oxidation. By contrast, enhancement of AMS-measurable organic mass by up to 30% was observed during the initial stage of oxidation of cloud water organics, which was followed by a decline at the later stages of oxidation. These observations are in support of the general hypothesis that cloud water oxidation is a viable route for SOA formation. In particular, we propose that additional SOA material was produced by functionalizing dissolved organics via OH oxidation, where these dissolved organics are sufficiently volatile that they are not usually part of the aerosol. This work demonstrates that water-soluble organic compounds of intermediate volatility (IVOC), such as cis-pinonic acid, produced via gas-phase oxidation of monoterpenes, can be important aqueous-phase SOA precursors in a biogenic-rich environment.
The impact of a future H2-based road transportation sector on the composition and chemistry of the atmosphere – Part 2: Stratospheric ozone
Authors: Wang D. , Jia W. , Olsen S. C. , Wuebbles D. J. , Dubey M. K. , Rockett A. A.
Published: August 2012

Abstract. The prospective future adoption of hydrogen to power the road transportation sector could greatly improve tropospheric air quality but also raises the question whether the adoption would have adverse effects on stratospheric ozone. The possibility of these undesirable impacts must be fully evaluated to guide future policy decisions. Here we evaluate the possible impact of a future (2050) H2-based road transportation sector on stratospheric composition and chemistry, especially on stratospheric ozone, with the MOZART chemical transport model. Since future growth is highly uncertain we evaluate the impact for two world evolution scenarios, one based on a high emitting scenario (IPCC A1FI) and the other on a low emitting scenario (IPCC B1), as well as two technological options: H2 fuel cells and H2 internal combustion engines. We assume a H2 leakage rate of 2.5% and a complete market penetration of H2 vehicles in 2050. The model simulations show that a H2-based road transportation sector would reduce stratospheric ozone concentrations as a result of perturbed catalytic ozone destruction cycles. The magnitude of the impact depends on which growth scenario the world evolves and which H2 technology option is applied. For the same world evolution scenario, stratospheric ozone decreases more in the H2 fuel cell scenarios than in the H2 internal combustion engine scenarios because of the NOx emissions in the latter case. If the same technological option is applied, the impact is larger in the A1FI emission scenario. The largest impact, a 0.54% decrease in annual average global mean stratospheric column ozone, is found with a H2 fuel cell type road transportation sector in the A1FI scenario; whereas the smallest impact, a 0.04% increase in stratospheric ozone, is found with applications of H2 internal combustion engine vehicles in the B1 scenario. The impacts of the other two scenarios fall between the above two bounding scenarios. However, the magnitude of these changes is much smaller than the increases in 2050 stratospheric ozone expected as stratospheric ozone recovers due to the limits in ozone depleting substance emissions imposed in the Montreal Protocol.
Fine-scale variability in methanol uptake and oxidation: from the microlayer to 1000 m
Authors: Dixon J. L. , Nightingale P. D.
Published: August 2012

Abstract. The aim of this research was to make the first depth profiles of the microbial assimilation of methanol carbon and its oxidation to carbon dioxide and use as an energy source from the microlayer to 1000 m. Some of the highest reported methanol oxidation rate constants of 0.5–0.6 d−1 were occasionally found in the microlayer and immediately underlying waters (10 cm depth), albeit these samples also showed the greatest heterogeneity compared to other depths down to 1000 m. Methanol uptake into the particulate phase was exceptionally low in microlayer samples, suggesting that any methanol utilised by microbes in this environment is for energy generation. The sea surface microlayer and 10 cm depth also showed a higher proportion of bacteria with a low DNA content, and bacterial leucine uptake rates in surface microlayer samples were either less than or the same as those in the underlying 10 cm layer. The average methanol oxidation and particulate rates were however statistically the same throughout the depths sampled, although the latter were highly variable in the near-surface 0.25–2 m compared to deeper depths. The statistically significant relationship demonstrated between uptake of methanol into particles and bacterial leucine incorporation suggests that many heterotrophic bacteria could be using methanol carbon for cellular growth. On average, methanol bacterial growth efficiency (BGEm) in the top 25 m of the water column is 6% and decreases with depth. Although, for microlayer and 10 cm-depth samples, BGEm is less than the near-surface 25–217 cm, possibly reflecting increased environmental UV stress resulting in increased maintenance costs, i.e. energy required for survival. We conclude that microbial methanol uptake rates, i.e. loss from seawater, are highly variable, particularly close to the seawater surface, which could significantly impact upon seawater concentrations and hence the air–sea flux.
CO2 increases 14C-primary production in an Arctic plankton community
Authors: Engel A. , Borchard C. , Piontek J. , Schulz K. , Riebesell U. , Bellerby R.
Published: August 2012

Abstract. Responses to ocean acidification in plankton communities were studied during a CO2-enrichment experiment in the Arctic Ocean, accomplished from June to July 2010 in Kongsfjorden, Svalbard (78°56, 2' N, 11°53, 6' E). Enclosed in 9 mesocosms (volume: 43.9–47.6 m3), plankton was exposed to CO2 concentrations, ranging from glacial to projected mid-next-century levels. Fertilization with inorganic nutrients at day 13 of the experiment supported the accumulation of phytoplankton biomass, as indicated by two periods of high Chl a concentration. This study tested for CO2 sensitivities in primary production (PP) of particulate organic carbon (PPPOC) and of dissolved organic carbon (PPDOC). Therefore, 14C-bottle incubations (24 h) of mesocosm samples were performed at 1 m depth receiving about 60% of incoming radiation. PP for all mesocosms averaged 8.06 ± 3.64 μmol C l−1 d−1 and was slightly higher than in the outside fjord system. Comparison between mesocosms revealed significantly higher PPPOC at elevated compared to low pCO2 after nutrient addition. PPDOC was significantly higher in CO2 enriched mesocosms before as well as after nutrient addition, suggesting that CO2 had a direct influence on DOC production. DOC concentrations inside the mesocosms increased before nutrient addition and more in high CO2 mesocosms. After addition of nutrients, however, further DOC accumulation was negligible and not significantly different between treatments, indicating rapid utilization of freshly produced DOC. Bacterial biomass production (BP) was coupled to PP in all treatments, indicating that 3.5 ± 1.9% of PP, or 21.6 ± 12.5% of PPDOC provided sufficient carbon for synthesis of bacterial biomass. The response of 14C-based PP rates to CO2 enrichment was at odds with O2-based net community production (NCP) rates that were also determined during this study, albeit at lower light level. We conclude that the enhanced release of labile DOC during autotrophic production at high CO2 exceedingly stimulated activities of heterotrophic microorganisms. As a consequence, increased PP induced less NCP, as suggested earlier for carbon limited microbial systems in the Arctic.
CO2 exchange in a temperate marginal sea of the Mediterranean Sea: processes and carbon budget
Authors: Cossarini G. , Querin S. , Solidoro C.
Published: August 2012

Abstract. Marginal seas play a potentially important role in the global carbon cycle; however, due to differences in the scales of variability and dynamics, marginal seas are seldom fully accounted for in global models or estimates. Specific high-resolution studies may elucidate the role of marginal seas and assist in the compilation of a complete global budget. In this study, we investigated the air-sea exchange and the carbon cycle dynamics in a marginal sub-basin of the Mediterranean Sea (the Adriatic Sea) by adopting a coupled transport-biogeochemical model of intermediate complexity including carbonate dynamics. The Adriatic Sea is a highly productive area owed to riverine fertilisation and is a site of intense dense water formation both on the northern continental shelf and in the southern sub-basin. Therefore, the study area may be an important site of CO2 sequestration in the Mediterranean Sea. The results of the model simulation show that the Adriatic Sea, as a whole, is a CO2 sink with a mean annual flux of 36 mg m−2 day−1. The northern part absorbs more carbon (68 mg m−2 day−1) due to an efficient continental shelf pump process, whereas the southern part behaves similar to an open ocean. Nonetheless, the Southern Adriatic Sea accumulates dense, southward-flowing, carbon-rich water produced on the northern shelf. During a warm year and despite an increase in aquatic primary productivity, the sequestration of atmospheric CO2 is reduced by approximately 15% due to alterations of the solubility pump and reduced dense water formation. The seasonal cycle of temperature and biological productivity modulates the efficiency of the carbon pump at the surface, whereas the intensity of winter cooling in the northern sub-basin leads to the export of C-rich dense water to the deep layer of the southern sub-basin and, subsequently, to the interior of the Mediterranean Sea.
Web 2.0 collaboration tool to support student research in hydrology – an opinion
Authors: Pathirana A. , Gersonius B. , Radhakrishnan M.
Published: August 2012

Abstract. A growing body of evidence suggests that it is unwise to make the a-priori assumption that university students are ready and eager to embrace modern online technologies employed to enhance the educational experience. We present our opinion on employing Wiki, a popular Web 2.0 technology, in small student groups, based on a case-study of using it customized to work as a personal learning environment (PLE1) (Fiedler and Väljataga, 2011) for supporting thesis research in hydrology. Since inception in 2006, the system presented has proven to facilitate knowledge construction and peer-communication within and across groups of students of different academic years and to stimulate learning. Being an open ended and egalitarian system, it was a minimal burden to maintain, as all students became content authors and shared responsibility. A number of unintended uses of the system were also observed, like using it as a backup medium and mobile storage. We attribute the success and sustainability of the proposed Web 2.0-based approach to the fact that the efforts were not limited to the application of the technology, but comprised the creation of a supporting environment with educational activities organized around it. We propose that Wiki-based PLEs are much more suitable than traditional learning management systems for supporting non-classroom education activities like thesis research in hydrology. 1Here we use the term PLE to refer to the conceptual framework to make the process of knowledge construction a personalized experience – rather than to refer to the technology (in this case Wiki) used to attempt implementing such a system.
The ring current: a short biography
Authors: Egeland A. , Burke W. J.
Published: August 2012

Abstract. The "ring current'' grows in the inner magnetosphere during magnetic storms and contributes significantly to characteristic perturbations to the Earth's field observed at low-latitudes. This paper outlines how understanding of the ring current evolved during the half-century intervals before and after humans gained direct access to space. Its existence was first postulated in 1910 by Carl Størmer to explain the locations and equatorward migrations of aurorae under stormtime conditions. In 1917 Adolf Schmidt applied Størmer's ring-current hypothesis to explain the observed negative perturbations in the Earth's magnetic field. More than another decade would pass before Sydney Chapman and Vicenzo Ferraro argued for its necessity to explain magnetic signatures observed during the main phases of storms. Both the Størmer and Chapman–Ferraro models had difficulties explaining how solar particles entered and propagated in the magnetosphere to form the ring current. During the early 1950s Hannes Alfvén correctly argued that the ring current was a collective plasma effect, but failed to explain particle entry. The discovery of a weak but persistent interplanetary magnetic field embedded in a continuous solar wind provided James Dungey with sufficient evidence to devise the magnetic merging-reconnection model now regarded as the basis for understanding magnetospheric and auroral activity. In the mid-1960s Louis Frank showed that ions in the newly discovered plasma sheet had the energy spectral characteristics needed to explain the ring current's origin. The introduction of ion mass spectrometers on space missions during the 1970s revealed that O+ ions from the ionosphere contribute large fractions of the ring current's energy content. Precisely how cold O+ ions in the ionosphere are accelerated to ring-current energies still challenges scientific understanding.
MISALIGNMENT CALIBRATION OF ULTRACAM D AND XP
Authors: Malihi S. , Maboudi M. , Pourmomen M.
Published: August 2012

Abstract. Digital aerial cameras are near to become the predominant sensor for photogrammetric image acquisition. The technology of GPS and IMU integrated with a digital aerial camera is a complex procedure of aerial photography with possibility of decreasing number of necessary ground control points (GCPs) for aerial triangulation (AT). Moreover, direct georeferencing, which uses calculated parameters by GPS/IMU directly, is undertaken for a range of projects. In this regard determination of the geometric relationship between GPS, IMU and camera geometry is a significant factor. Also compensation of camera rotations during the flight, which is carried out by stabilizer, plays a principle role for its successful operation. This paper will discuss calculation of 3 requisite rotational connecting parameters of geometry of camera and GPS/IMU and revise the effect of height on them.
In situ determination of the remote sensing reflectance: an inter-comparison
Authors: Zibordi G. , Ruddick K. , Ansko I. , Moore G. , Kratzer S. , Icely J. , Reinart A.
Published: August 2012

Abstract. Inter-comparison of data products from simultaneous measurements performed with independent systems and methods is a viable approach to assess the consistency of data and additionally to investigate uncertainties. Within such a context the inter-comparison called Assessment of In Situ Radiometric Capabilities for Coastal Water Remote Sensing Applications (ARC) was carried out at the Acqua Alta Oceanographic Tower in the northern Adriatic Sea to explore the accuracy of in situ data products from various in- and above-water optical systems and methods. Measurements were performed under almost ideal conditions, including a stable deployment platform, clear sky, relatively low sun zenith angles and moderately low sea state. Additionally, all optical sensors involved in the experiment were inter-calibrated through absolute radiometric calibration performed with the same standards and methods. Inter-compared data products include spectral water-leaving radiance Lw (λ), above-water downward irradiance Ed(0+,λ) and remote sensing reflectance Rrs(λ). Data products from the various measurement systems/methods were directly compared to those from a single reference system/method. Results for Rrs(λ) indicate spectrally averaged values of relative differences comprised between −1 and +6%, while spectrally averaged values of absolute differences vary from approximately 6% for the above-water systems/methods to 9% for buoy-based systems/methods. The agreement between Rrs(λ) spectral relative differences and estimates of combined uncertainties of the inter-compared systems/methods is noteworthy.
Rhetoric's Other:
Authors: Lipari Lisbeth
Published: August 2012

It does not seem terribly unfair to say that studies of both rhetoric and dialogue have tended, by and large, to pass over listening in favor of speaking. In scholarly as well as quotidian parlance, it would appear that both rhetoric and dialogue are principally concerned with speech, banishing listening to the silent subservience of rhetoric's other. Whichever way it is glossed—as rhetoric, dialogue, language, or argumentation—the Western conception of logos emphasizes speaking at the expense of listening (Fiumara 1990). And the problem with conceiving of logos in terms of speech and speaking is not only that it ignores the importance of listening but also that it obscures how listening makes the ethical response possible. Drawing on the philosophy of Emmanuel Levinas, this article examines the ethical exigency of the face and its relation to primordial discourse in order to disclose the otherwise hidden ethical significance of listening and its vocation as a form of co-constitutive communicative action that can “listen persons to speech.”