bluuebunny/crossref_metadata_2025 huggingface dataset:
Is It Possible to Train Patients to Limit Weight Bearing on a Lower Extremity?
Authors: Hustedt Joshua W. , Blizzard Daniel J. , Baumgaertner Michael R. , Leslie Michael P. , Grauer Jonathan N.
Published: January 2012

Orthopedic patients are often instructed on how much weight to bear on an injured or postoperative extremity. Although specific weight-bearing instructions are given to a majority of lower-extremity orthopedic patients, the ability of patients to comply with these instructions is questioned in the medical literature. This study compared the effectiveness of new forms of clinical interventions designed to train patients on weight bearing, focusing on the use of biofeedback devices designed to offer real-time feedback to partial weight-bearing patients. Twenty healthy patients aged 20 to 30 years completed 3 interventions: (1) verbal instructions on weight bearing, (2) training with a bathroom scale, and (3) training with a biofeedback device.

Patients given touchdown weight-bearing instructions (25 lb) initially bore an average of 63.57±6.24 lb when given verbal instructions. This was reduced to 44.75±5.69 lb after training with a bathroom scale (
P
<.001), and was further reduced to 26.2±1.57 lb with biofeedback training (
P=
.011). Likewise, patients given partial weight-bearing instructions (75 lb) initially bore an average of 92.28±7.85 lb. No improvement occurred with the use of a bathroom scale (at 75 lb), which showed an average of 90.82±7.19 lb (
P=
1.000). Training with a biofeedback device improved the average weight bearing to 69.67±3.18 lb (
P=
.014).

Biofeedback training led to superior compliance with touchdown and partial weight-bearing instructions. Because partial weight-bearing instructions are commonly given to orthopedic patients, training with such a device may be appropriately considered.
Use of an Oblique Obturator Radiograph in Aspiration at Anterior Iliac Crest
Authors: Ebraheim Nabil A. , Zhang Jingwei , Lause Gregory E.
Published: January 2012

The purpose of this study was to evaluate the use of an oblique obturator radiograph in bone marrow aspiration. The authors retrospectively reviewed 22 patients who underwent bone marrow aspiration guided by the real-time oblique obturator radiograph while in a supine position at their institution between November 2009 and August 2010. The mean duration of bone marrow aspiration was 35±9 seconds. According to the visual analog scale, the postoperative pain score at the site of aspiration was an average 1.6 of 10. No complications were observed. The oblique obturator radiograph can improve the accuracy of the aspiration.
Nocardia Spinal Epidural Abscess: 14-year Follow-up
Authors: West Kristoffer R. , Mason Robert C. , Sun Mike
Published: January 2012

This article describes an immunocompetent patient with a spinal abscess that developed from
Nocardia asteroides. Nocardia
is a rare etiology for spinal abscesses, especially in immunocompetent patients.
Nocardia
usually affects the lungs and brain of immunocompromised individuals. Few reports of
Nocardia
involving bones or the spine have been published.

The patient had a history of chronic back pain and had several procedures to alleviate the pain. In August 1997, the patient had an epidural block and a subsequent infection that was treated with antibiotics. In October 1997, she developed increasing back pain greater than her baseline chronic low back pain. Additional presenting symptoms were fever, chills, and nausea. On admission, magnetic resonance imaging (MRI) revealed an epidural abscess. The patient underwent irrigation and debridement. Postoperatively, the patient was initially placed on broad-spectrum antibiotics. After 38 days, the culture was identified as
N asteroides
, and the patient was placed on appropriate antibiotics. The patient has been followed with MRI prior to the discovery of the abscess and annually since the abscess due to her baseline chronic low back pain. No residual abscess was discovered.
Piercing Injury of the Pelvis With a Steel Bar
Authors: Lee Soon Hyuck , Park Si Young , Kim Jin , Huh Young-Jae
Published: January 2012

A piercing or penetrating injury of the pelvis by a steel bar is a rare condition compared with piercing or penetrating injuries of the extremities. We report the case of a 34-year-old woman who attempted a suicidal fall that resulted in the piercing of the pelvis with a long steel bar. The steel bar entered the pelvic cavity from the left buttock through the sciatic notch and was bent at the middle of the pelvic cavity between the bladder and rectum. At the right hip joint, the rod penetrated the posteromedial aspect of the femoral head, was bent again, and extended straight along the medial border of the femur without damaging the femoral neurovascular bundle. At the middle one-third level, the bar spanned in a posterolateral direction and then down toward the lateral aspect at the level of the mid-calf. The bar exited the lateral side of the left calf.

An explorative laparotomy was performed to ensure that no intraperitoneal injury had occurred. The smaller portion of the uterus bicornis was the only organ that had been pierced. The penetrated uterus was incised to expose the bent portion of the bar. The bar was cut in half using a diamond burr, and the cutting edge was trimmed so as not to injure the surrounding organs during removal. The second bent portion of the rod, located in the right hip joint, was straightened by positional reduction, and the hip joint was abducted under fluoroscopic monitoring from outside of the operative field by grasping the end of the bar remaining in the pelvic cavity. The steel bar was safely removed and treated after careful planning and multiteam approaches with a general surgeon and orthopedic trauma specialists.
Intracranial Meningeal Hemangiopericytoma Metastatic to the Scapula
Authors: Siegel Herrick J. , Lopez-Ben Robert , Sutton J. Hunter , Siegal Gene P.
Published: January 2012

Meningeal hemangiopericytomas are rare vascular tumors that have a propensity for recurrence and metastasis. Intracranial hemangiopericytomas are rare vascular tumors. They account for 0.5% of primary central nervous system tumors and 2% of meningiomas. Unlike usual benign meningiomas, which rarely metastasize extracranially, meningeal hemangiopericytoma has a high rate of local recurrence and distant metastasis. The treatment paradigms for hemangiopericytomas and meningiomas differ based on their biological behaviors. Hemangiopericytomas have higher rates of recurrence and metastasis compared with meningiomas. Intracranial meningeal hemangiopericytoma is characterized by clinically repeated local recurrences at the primary site. Bone, liver, lung, central nervous system, and abdominal cavity are the most commonly reported sites of metastasis in hemangiopericytomas.

This article describes a case of bone metastasis with extensive involvement of the scapula from intracranial hemangiopericytoma. Bone metastasis can be seen in a relatively late phase of the disease, with metastasis to other organs. Although radiation therapy is effective in controlling pain from bone metastases in unresectable disease and those with extensive visceral metastases, aggressive local surgical control of a solitary bone metastasis may be an option for patients with limited distant disease. The diagnosis may be initially confused with clear cell meningioma and benign meningiomas. The management of bone metastasis is not well reported in the orthopedic literature.
Chronic Pain in Older Adults
Authors: Bernhofer Esther I. , Sorrell Jeanne M.
Published: January 2012

Despite the sophisticated pharmaceutical agents and technologies available today, many people, including older adults, continue to experience chronic pain. Inadequately treated chronic pain can seriously affect one’s quality of life. Health care providers are only beginning to understand the structural and functional changes that occur in older adults with chronic pain, but recent research suggests that nurses and other health professionals need to become aware of the unique needs of older adults who live with chronic pain. When health professionals lack specific knowledge of pain management in older adults, patients may suffer needlessly.
Now Take a Deep Breath: Inhaled Loxapine for the Treatment of Acute Agitation
Authors: Howland Robert H.
Published: January 2012

Acute agitation in patients with schizophrenia or bipolar disorder is an important clinical management problem. Liquid concentrates, orally disintegrating tablets, and/or intramuscular formulations of several second-generation atypical antipsychotic drugs are available for treating acute agitation. Loxapine is an older first-generation antipsychotic drug that is approved for the treatment of schizophrenia. Staccato
®
loxapine is an investigational device system using a loxapine-coated heat source to administer loxapine by inhalation. Three multicenter, randomized, double-blind, placebo-controlled efficacy and safety studies of Staccato loxapine have been conducted in patients with acute agitation associated with schizophrenia or bipolar disorder. These studies found that inhaled loxapine was rapidly effective and generally well tolerated, although there are potential concerns about adverse pulmonary effects.
Intratympanic Injection of Dexamethasone for Treatment of Tinnitus in Patients with Sudden Sensorineural Hearing Loss
Authors: Yoshida Tadao , Teranishi Masaaki , Iwata Tomoyuki , Otake Hironao , Nakashima Tsutomu
Published: January 2012

The purpose of this study is to test the effectiveness of intratympanic dexamethasone injections as a treatment for severe tinnitus in idiopathic sudden sensorineural hearing loss (SNHL). We studied 37 patients who received intratympanic dexamethasone injections and 14 control patients who did not receive it, with severe tinnitus after onset of unilateral sudden SNHL. Hearing level did not change during this study in any patient. The relationship between the duration of tinnitus and effectiveness of treatment was investigated in sudden SNHL. We used a visual analogue scale to evaluate 51 patients with severe tinnitus at the stage of stable hearing level after idiopathic sudden sensorineural hearing loss. Forty-one per cent of patients showed significant improvement after treatment. The average period between onset of sudden sensorineural hearing loss and initiation of intratympanic dexamethasone injection was significantly shorter (207 days) in the improved group than in the unchanged group (482 days) (P<0.001). In control group, one of 14 patients presented significant improvement spontaneously. Intratympanic dexamethasone treatment may be effective in treatment of severe tinnitus after sudden SNHL at the stage of stable hearing level, and the shorter the period from onset of sudden deafness to the start of intratympanic dexamethasone treatment, the greater the improvement in tinnitus that can be expected.
The Woodward Technique for Sprengel Deformation
Authors: Ngowe Marcelin Ngowe , Farikou Ibrahim , Mouafo Tambo Faustin Félicien , Nonga Bernadette Ngo , Andze Gervais Ondobo , Sosso Maurice Aurélien
Published: January 2012

A case of 5-year-old boy with a left congenital undescended scapula graded Cavendish III was consulted in our unit and operated successfully with the Woodward technique. It was the first case treated by this procedure for the past 10 years, in the Pediatric Surgical Unit of the Yaounde Gyneco-Obstetric and Pediatric Hospital (Cameroon). The Woodward procedure permitted to obtain a good functional and cosmetic result.
A history of lignite coal mining and reclamation practices in Lusatia, eastern Germany
Authors: Krümmelbein Julia , Bens Oliver , Raab Thomas , Anne Naeth M.
Published: January 2012

Krümmelbein, J., Bens, O., Raab, T. and Naeth, M. A. 2012. A history of lignite coal mining and reclamation practices in Lusatia, eastern Germany. Can. J. Soil Sci. 92: 53–66. Germany is the world's leading lignite coal producer. The region surrounding the towns of Cottbus and Senftenberg in Lusatia, Eastern Germany, is one of the largest mining areas in Germany, and has economically been strongly dependent on lignite mining and lignite processing industries since the middle of the 19th century. We introduce the area, give a brief historical overview of lignite mining techniques and concentrate on post-mining recultivation (reclamation) to agricultural and forestry dominated landscapes. An overview of the physical and chemical limitations for reclamation of the Tertiary and Quaternary substrates due to their natural composition and the technical processes of mine site construction is provided. We introduce some recultivation practices and end with a display of land uses before and after mining and an outlook on the future use of the reclaimed landscape. This review serves as a defined perspective on long-term coal mine reclamation from which to address global similarities and contrasts.
Laboratory-based nitrogen mineralization and biogeochemistry of two soils used in oil sands reclamation
Authors: MacKenzie M.D. , Quideau S.A.
Published: January 2012

MacKenzie, M. D. and Quideau, S. A. 2012. Laboratory-based nitrogen mineralization and biogeochemistry of two soils used in oil sands reclamation. Can. J. Soil Sci. 92: 131–142. In the Athabasca oil sands region of Alberta, Canada, peat mineral and upland forest floor mineral soils are salvaged and stockpiled for reclamation. Previous work showed that sites reclaimed with forest floor mineral soil had better understory regeneration and nitrogen dynamics more similar to naturally disturbed ecosystems. Both soils and a mixture of the two were compared in laboratory incubations by examining nitrogen mineralization (over 45 wk) and factorial fertility additions (4 wk trial with NPK) on microbial community structure and nutrient availability. Nitrogen mineralization indicated forest floor mineral soil had lower release rates and a higher estimated labile nitrogen pool than peat mineral soil. Nitrogen mineralization in mixed soil started like peat mineral soil and finished like forest floor mineral soil. Fertility additions influenced microbial community structure less than soil type. Multi-response permutation procedure indicated the forest floor mineral soil microbial community was significantly different from peat mineral and mixed soil communities. Control nutrient profiles differed from those with added NPK. Forest floor mineral soil retained nitrogen as ammonium, while peat mineral and mixed soils were nitrate dominated. Reclamation will require all soil types to be used and these data will help determine soil placement prescriptions.
Influence of biosolids and fertilizer amendments on element concentrations and revegetation of copper mine tailings
Authors: Gardner Wendy C. , Anne Naeth M. , Broersma Klaas , Chanasyk David S. , Jobson Allen M.
Published: January 2012

Gardner, W. C., Naeth, M. A., Broersma, K., Chanasyk, D. S. and Jobson, A. M. 2012. Influence of biosolids and fertilizer amendments on element concentrations and revegetation of copper mine tailings. Can. J. Soil Sci. 92: 89–102. A 3-yr field study on copper mine tailings in British Columbia determined the effects of fertilizer and biosolids on element concentrations in tailings and vegetation and on plant biomass. Biosolids applied at 50, 100, 150, 200 and 250 Mg ha−1(dry weight) increased total carbon, iron, magnesium, nickel, nitrogen, phosphorus, sulphur and zinc and available ammonium, iron, manganese, nitrate, phosphorus and zinc in tailings. With highest applications on silt loam tailings, total zinc (214 mg kg−1) exceeded Canadian Council of Ministers of the Environment guidelines for agricultural soils. Total chromium and copper exceeded these guidelines but not due to biosolids, being high in controls (chromium 38, 8; copper 647, 1291 mg kg−1; silt loam and sandy sites, respectively). Plant tissue calcium, phosphorus, magnesium, manganese, nitrogen and zinc increased with increasing biosolids. Plant tissue calcium (20 g kg−1) and molybdenum (5 mg kg−1) exceeded National Research Council maximums for beef cattle. Total molybdenum in unamended silt loam (35 mg kg−1) and sandy tailings (18 mg kg−1) and vegetation on silt loam (112 mg kg−1) were high. Biosolids had variable effects on tailings molybdenum and decreased total plant tissue molybdenum. Fertilizer and control treatments had limited plant growth. Managed biosolids use in reclamation can ameliorate sites and facilitate vegetation establishment, with low environmental risk.
Evaluation of substrate and amendment materials for soil reclamation at a diamond mine in the Northwest Territories, Canada
Authors: Drozdowski Bonnie L. , Anne Naeth M. , Wilkinson Sarah R.
Published: January 2012

Drozdowski, B. L., Naeth, M. A. and Wilkinson, S. R. 2012. Evaluation of substrate and amendment materials for soil reclamation at a diamond mine in the Northwest Territories, Canada. Can. J. Soil Sci. 92: 77–88. Mine waste materials with potential for use in soil construction at a diamond mine in the Northwest Territories were evaluated to address physical and chemical limitations for plant establishment, growth and development. Substrates were glacial till, gravel, processed kimberlite, and 50:50 and 25:75 mixes of processed kimberlite and till. Amendments were salvaged topsoil, sewage sludge, inorganic fertilizer and sludge from a water treatment facility. Reclamation soils constructed with these materials were adequate for revegetation. Mixes of processed kimberlite and glacial till enhanced soil structure and diluted adverse concentrations of elements. The original gravel pad, alone or amended, was a suitable substrate for plants. Addition of organic amendments topsoil and sludge, to any substrate, increased organic matter, nutrients and surface water retention. Of amendments evaluated, salvaged topsoil provided the most consistent increase in plant density among substrates. Inorganic fertilizer applied to gravel or till provided results similar to those with topsoil. Sludge had potential to amend mixes of processed kimberlite and till, although results were variable. Sewage was a good source of organic matter, increasing soil water content and macro nutrients. Vegetation response was poor in sewage-amended treatments likely due to combined effects of high copper, molybdenum, phosphorus, selenium, sulphate and zinc.
Leishmania infantum chagasi in Northeastern Brazil: Asymptomatic Infection at the Urban Perimeter
Authors: Lima Iraci D. , Queiroz Jose W. , Lacerda Henio G. , Queiroz Paula V. S. , Pontes Nubia N. , Barbosa James D. A. , Martins Daniella R. , Weirather Jason L. , Pearson Richard D. , Wilson Mary E. , Jeronimo Selma M. B.
Published: January 2012

Visceral leishmaniasis (VL) is endemic in large cities in Brazil, including Natal. We determined the prevalence of asymptomatic human infection with Leishmania infantum chagasi and associated environmental risks around Natal. Infection was detected by Leishmania skin test (LST) and anti-leishmanial antibodies in humans and anti-leishmanial antibodies in dogs. Amongst 345 humans, 24.6% were seropositive, and 38.6% were LST-positive. Prevalence of positive serology was similar in both sexes and across all ages. However, positive LST responses increased with age, suggesting that LST is long-lasting and cumulative. Multinomial logistic analysis showed that LST response varied with location (P = 0.007) and that males were more frequently LST-positive (P = 0.027). Indicators of lower socioeconomic status associated significantly with human infection. Furthermore, there was geographic coincidence of seropositive humans and dogs (r = 0.7926, P = 0.011). These data suggest that dog and human L. i. chagasi infection are intimately interrelated in environmental conditions associated with low income.
Evaluation of Serum Procalcitonin Levels for Diagnosis of Secondary Bacterial Infections in Visceral Leishmaniasis Patients
Authors: Pasyar Neda , Alborzi Abdolvahab , Pouladfar Gholam R.
Published: January 2012

Secondary bacterial infections are a major complication and cause of death in children with visceral Leishmaniasis (VL). Thus, early diagnosis of bacterial infections is an important step in the treatment of patients with VL. The goal of this study was to determine if serum procalcitonin (PCT) could be used as a diagnostic marker of secondary bacterial infections in VL patients. Serum PCT was measured in 35 hospitalized patients with VL before treatment and after defervescence. The level was higher than normal (> 0.5 ng/mL) in 72% (25) of the patients. Twelve (34%) of 35 patients had secondary bacterial infections with PCT levels ranging from 0.1 to 12.29 ng/mL, and those without secondary bacterial infections (23) had PCT levels ranging from 0.1 to 14.58 ng/mL. The results suggest that PCT levels increase significantly in most VL patients but are not correlated with the presence of secondary bacterial infections.
Persistence of Viral RNA in Chikungunya Virus-Infected Aedes aegypti (Diptera: Culicidae) Mosquitoes after Prolonged Storage at 28°C
Authors: Mavale Mangala , Sudeep Anakkathil , Gokhale Mangesh , Hundekar Supriya , Parashar Deepti , Ghodke Youwaraj , Arankalle Vidya , Mishra Akhilesh Chandra
Published: January 2012

Experiments were conducted to determine the persistence of chikungunya viral (CHIKV) RNA in experimentally infected Aedes aegypti mosquitoes stored for prolonged periods at 28°C. Intra-thoracically inoculated mosquitoes with confirmed positivity were killed by quick freezing at -80°C, applied to sticky tape, and stored at 28°C with 80 ± 5% relative humidity (RH). At weekly intervals, five mosquitoes were removed from the tape randomly and assayed individually for detection of viral RNA by reverse transcriptase-polymerase chain reaction (RT-PCR). CHIKV RNA was detected up to 12 weeks in dry mosquitoes by RT-PCR. Virus could not be isolated either in cell culture or in the suckling Swiss-albino mouse system at any stage. This study demonstrated the persistence of CHIKV viral RNA up to 12 weeks when stored at 28°C with RH 80 ± 5%. This finding will have significance in CHIKV surveillance programs in mosquito populations or field-based studies in countries where maintenance of a cold chain is a concern.
Horizontal and Vertical Transmission of West Nile Virus Genotype NY99 by Culex salinarius and Genotypes NY99 and WN02 by Culex tarsalis
Authors: Anderson John F. , Main Andy J. , Cheng Gong , Ferrandino Francis J. , Fikrig Erol
Published: January 2012

Culex tarsalis is a superior horizontal and vertical vector of West Nile virus (WNV) compared with Culex salinarius. Culex salinarius transmitted WNV genotype NY99 (CT 2741-99 strain) horizontally to suckling mice at significantly lower rates than Cx. tarsalis on Days 8, 9, 10, and 12 post-infection, and Cx. salinarius transmitted WNV genotype NY99 to offspring at a lower vertical transmission infection rate than Cx. tarsalis. Culex tarsalis transmitted WNV genotypes NY99 and WN02 (CT S0084-08 strain) with equal efficiency. Daily percent horizontal transmission of genotype NY99 by Cx. tarsalis-infected per os and by intra-thoracic infection was not significantly different from daily transmission of genotype WN02 from Days 5–23 and Days 2–9 post-infection, respectively. Our findings do not support the previously published hypothesis that genotype NY99 was replaced in the New World by WN02 because of a shorter extrinsic incubation of WN02.
Acid-yield measurements of the gas-phase ozonolysis of ethene as a function of humidity using Chemical Ionisation Mass Spectrometry (CIMS)
Authors: Leather K. E. , McGillen M. R. , Cooke M. C. , Utembe S. R. , Archibald A. T. , Jenkin M. E. , Derwent R. G. , Shallcross D. E. , Percival C. J.
Published: January 2012

Abstract. Gas-phase ethene ozonolysis experiments were conducted at room temperature to determine formic acid yields as a function of relative humidity (RH) using the integrated EXTreme RAnge chamber-Chemical Ionisation Mass Spectrometry technique, employing a CH3I ionisation scheme. RHs studied were <1, 11, 21, 27, 30 % and formic acid yields of (0.07±0.01) and (0.41±0.07) were determined at <1 % RH and 30 % RH respectively, showing a strong water dependence. It has been possible to estimate the ratio of the rate coefficient for the reaction of the Criegee biradical, CH2OO with water compared with decomposition. This analysis suggests that the rate of reaction with water ranges between 1×10−12–1×10−15 cm3 molecule−1 s−1 and will therefore dominate its loss with respect to bimolecular processes in the atmosphere. Global model integrations suggest that this reaction between CH2OO and water may dominate the production of HC(O)OH in the atmosphere.
The stable isotopic composition of molecular hydrogen in the tropopause region probed by the CARIBIC aircraft
Authors: Batenburg A. M. , Schuck T. J. , Baker A. K. , Zahn A. , Brenninkmeijer C. A. M. , Röckmann T.
Published: January 2012

Abstract. More than 450 air samples that were collected in the upper troposphere – lower stratosphere (UTLS) region around the tropopause (TP) by the CARIBIC aircraft (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) have been analyzed for molecular hydrogen (H2) mixing ratios (m(H2)) and H2 isotopic composition (deuterium content, δD). More than 120 of the analysed samples consisted of air from the lowermost stratosphere (LMS). These show that m(H2) does not vary appreciably with O3-derived height above the thermal TP, whereas δD does increase with height. The isotope enrichment is caused by competing H2 production and destruction processes that enrich the stratospheric H2 reservoir in deuterium (D); the exact shapes of the profiles are mainly determined by mixing of stratospheric with tropospheric air. Tight negative correlations are found between δD and the mixing ratios of methane (CH4) and nitrous oxide (N2O), as a result of the relatively long lifetimes of these three species. The correlations are described by δ D [‰]=-0.35 · m(CH4)[ppb]+768 and δD [‰]=-1.90 · m(N2O)[ppb]+745. These correlations are similar to previously published results and likely hold globally. Samples that were collected from the Indian subcontinent up to 40° N before, during and after the summer monsoon season show no significant seasonal change in m(H2), but δD is up to 15‰ lower in the July, August and September monsoon samples. This δD lowering is correlated with m(CH4) increase. The significant correlation with m(CH4) and the absence of a perceptible m(H2) increase that accompanies the δD lowering indicates that microbial production of very D-depleted H2 in the wet season may contribute to this phenomenon. Some of the samples have very high m(H2) and very low δD values, which indicates a pollution effect. Aircraft engine exhaust plumes are a suspected cause, since the effect mostly occurs in samples collected close to airports, but no similar signals are found in other chemical tracers to support this. The isotopic source signature of the H2 pollution seems to be on the low end of the signature for fossil fuel burning.
Intercomparison of modal and sectional aerosol microphysics representations within the same 3-D global chemical transport model
Authors: Mann G. W. , Carslaw K. S. , Ridley D. A. , Spracklen D. V. , Pringle K. J. , Merikanto J. , Korhonen H. , Schwarz J. P. , Lee L. A. , Manktelow P. T. , Woodhouse M. T. , Schmidt A. , Breider T. J. , Emmerson K. M. , Reddington C. L. , Chipperfield M. P. , Pickering S. J.
Published: January 2012

Abstract. A global modal aerosol microphysics module (GLOMAP-mode) is evaluated and improved by comparing against a sectional version (GLOMAP-bin) and observations in the same 3-D global offline chemistry transport model. With both schemes, the model captures the main features of the global particle size distribution, with sub-micron aerosol approximately unimodal in continental regions and bi-modal in marine regions. Initial bin-mode comparisons showed that various size distribution parameter settings (mode widths and inter-modal separation sizes) resulted in clear biases compared to the sectional scheme. By adjusting these parameters in the modal scheme, much better agreement is achieved against the bin scheme and observations. Surface mass of sulphate, sea-salt, black carbon (BC) and organic carbon (OC) are, on the annual mean, within 25 % in the two schemes in nearly all regions. On the annual mean, surface level concentrations of condensation nuclei (CN), cloud condensation nuclei (CCN), surface area density and condensation sink also compare within 25 % in most regions. However, marine CCN concentrations between 30° N and 30° S are systematically higher in the modal scheme, by 25–60 %, which we attribute to differences in size-resolved particle growth or cloud-processing. Larger differences also exist in regions or seasons dominated by biomass burning and in free-troposphere and high-latitude regions. Indeed, in the free-troposphere, GLOMAP-mode BC is a factor 2–4 higher than GLOMAP-bin, likely due to differences in size-resolved scavenging. Nevertheless, in most parts of the atmosphere, we conclude that bin-mode differences are much less than model-observation differences, although some processes are missing in these runs which may pose a bigger challenge to modal schemes (e.g. boundary layer nucleation, ultra-fine sea-spray). The findings here underline the need for a spectrum of complexity in global models, with size-resolved aerosol properties predicted by modal schemes needing to be continually benchmarked and improved against freely evolving sectional schemes and observations.
Estimating cloud optical thickness and associated surface UV irradiance from SEVIRI by implementing a semi-analytical cloud retrieval algorithm
Authors: Pandey P. , De Ridder K. , Gillotay D. , van Lipzig N. P. M.
Published: January 2012

Abstract. In this paper, we describe the implementation of the Semi-Analytical Cloud Retrieval Algorithm (SACURA), to obtain scaled cloud optical thickness (SCOT) from satellite imagery acquired with the SEVIRI instrument and surface UV irradiance levels. In estimation of SCOT particular care is given to the proper specification of the background (i.e., cloud-free) spectral albedo and the retrieval of the cloud water phase from reflectance ratios in SEVIRI's 0.6 μm and 1.6 μm spectral bands. The SACURA scheme is then applied to daytime SEVIRI imagery over Europe, for the month of June 2006, at 15-min time increments. The resulting SCOT fields are compared with values obtained by the CloudSat experimental satellite mission, yielding a negligible bias, correlation coefficients ranging from 0.51 to 0.78, and a root mean square difference of 1 to 2 SCOT increments. These findings compare favourably to results from similar intercomparison exercises reported in the literature. Based on the retrieved SCOT from SEVIRI and radiative transfer modelling approach, simple parameterisations are proposed to estimate the surface UV-A and UV-B irradiance. The validation of the modelled UV-A and UV-B irradiance against the measurements over two Belgian stations, Redu and Ostend, indicate good agreement with the high correlation, index of agreement and low bias. The SCOT fields estimated by implementing SACURA on imagery from geostationary satellite are reliable and its impact on surface UV irradiance levels is well produced.
First measurements of reactive α-dicarbonyl concentrations on PM2.5 aerosol over the boreal forest in Finland during HUMPPA-COPEC 2010 – source apportionment and links to aerosol aging
Authors: Kampf C. J. , Corrigan A. L. , Johnson A. M. , Song W. , Keronen P. , Königstedt R. , Williams J. , Russell L. M. , Petäjä T. , Fischer H. , Hoffmann T.
Published: January 2012

Abstract. The first dataset for summertime boreal forest concentrations of two atmospherically relevant α-dicarbonyl compounds, glyoxal (Gly) and methylglyoxal (Mgly) on PM2.5 aerosol was obtained during the HUMPPA-COPEC-2010 field measurement intensive in Hyytiälä, Finland. Identification of anthropogenic influences over the course of the campaign, using trace gas signatures and aerosol particle chemical composition analysis, allowed the identification of different events such as urban pollution plumes, biomass burning and sawmill emissions as sources of high Gly and Mgly concentrations. Mean aerosol concentrations during periods of biogenic influence were 0.81 ng m−3 for Gly and 0.31 ng m−3 for Mgly. Mgly was generally less abundant in PM2.5, probably due to its shorter photolysis lifetime and less effective partitioning into the particle phase due to its smaller effective Henry's Law constant compared to Gly. This is in contrast with previous urban studies which show significantly more Mgly than Gly. Peak concentrations for Gly coincided with nearby sources, e.g. high VOC emissions from nearby sawmills, urban pollution plumes from the city of Tampere located 50 km southwest of the sampling site and biomass burning emissions from wildfires. Calculated ratios of Gly in PM2.5 and total organic matter in PM1 aerosols indicate higher values in less aged aerosols. Irreversible processing of Gly in the particle phase, e.g. via oxidation by OH radicals, organo sulfate or imidazole formation are processes currently discussed in the literature which could likely explain these findings.
Autofluorescence of atmospheric bioaerosols – fluorescent biomolecules and potential interferences
Authors: Pöhlker C. , Huffman J. A. , Pöschl U.
Published: January 2012

Abstract. Primary biological aerosol particles (PBAP) are an important subset of air particulate matter with a substantial contribution to the organic aerosol fraction and potentially strong effects on public health and climate. Recent progress has been made in PBAP quantification by utilizing real-time bioaerosol detectors based on the principle that specific organic molecules of biological origin such as proteins, coenzymes, cell wall compounds and pigments exhibit intrinsic fluorescence. The properties of many fluorophores have been well documented, but it is unclear which are most relevant for detection of atmospheric PBAP. The present study provides a systematic synthesis of literature data on potentially relevant biological fluorophores. We analyze and discuss their relative importance for the detection of fluorescent biological aerosol particles (FBAP) by online instrumentation for atmospheric measurements such as the ultraviolet aerodynamic particle sizer (UV-APS) or the wide issue bioaerosol sensor (WIBS). In addition, we provide new laboratory measurement data for selected compounds using bench-top fluorescence spectroscopy. Relevant biological materials were chosen for comparison with existing literature data and to fill in gaps of understanding. The excitation-emission matrices (EEM) exhibit pronounced peaks at excitation wavelengths of ~280 nm and ~360 nm, confirming the suitability of light sources used for online detection of FBAP. They also show, however, that valuable information is missed by instruments that do not record full emission spectra at multiple wavelengths of excitation, and co-occurrence of multiple fluorophores within a detected sample will likely confound detailed molecular analysis. Selected non-biological materials were also analyzed to assess their possible influence on FBAP detection and generally exhibit only low levels of background-corrected fluorescent emission. This study strengthens the hypothesis that ambient supermicron particle fluorescence in wavelength ranges used for most FBAP instruments is likely to be dominated by biological material and that such instrumentation is able to discriminate between FBAP and non-biological material in many situations. More detailed follow-up studies on single particle fluorescence are still required to reduce these uncertainties further, however.
Continuous measurements of methane mixing ratios from ice cores
Authors: Stowasser C. , Buizert C. , Gkinis V. , Chappellaz J. , Schüpbach S. , Bigler M. , Faïn X. , Sperlich P. , Baumgartner M. , Schilt A. , Blunier T.
Published: January 2012

Abstract. This work presents a new, field-deployable technique for continuous, high-resolution measurements of methane mixing ratios from ice cores. The technique is based on a continuous flow analysis system, where ice core samples cut along the long axis of an ice core are melted continuously. The past atmospheric air contained in the ice is separated from the melt water stream via a system for continuous gas extraction. The extracted gas is dehumidified and then analyzed by a Wavelength Scanned-Cavity Ring Down Spectrometer for methane mixing ratios. We assess the performance of the new measurement technique in terms of precision (±0.8 ppbv, 1 σ), accuracy (±8 ppbv), temporal (ca. 100 s) and spatial resolution (ca. 6 cm). Using a firn air transport model, we compare the resolution of the measurement technique to the resolution of the atmospheric methane signal as preserved in ice cores in Greenland. We conclude that our measurement technique can resolve all climatically relevant variations as preserved in the ice down to an ice depth of at least 1980 m (66 000 yr before present) in the North Greenland Eemian Ice Drilling ice core. Furthermore, we describe the modifications which are necessary to make a commercially available spectrometer suitable for continuous methane mixing ratio measurements from ice cores.
Remote sensing of CO2 and CH4 using solar absorption spectrometry with a commercial low resolution spectrometer
Authors: Petri C. , Warneke T. , Jones N. , Ridder T. , Messerschmidt J. , Weinzierl T. , Geibel M. , Notholt J.
Published: January 2012

Abstract. Throughout the last few years solar absorption Fourier Transform Spectrometry (FTS) has been further developed to measure the total columns of CO2 and CH4. The observations are performed at high spectral resolution, typically at 0.02 cm−1. The precision achieved is actually generally better than 0.25%. However, these high resolution instruments are quite large and need a dedicated room or container for installation. We performed these observations using a smaller commercial interferometer at its maximum possible resolution of 0.11 cm−1. The measurements have been performed at Bremen and have been compared to observations using our high resolution instrument also situated at the same location. The high resolution instrument has been successfully operated as part of the Total Carbon Column Observing Network (TCCON). The precision of the low resolution instrument is 0.32% for XCO2 and 0.46% for XCH4. A comparison of the measurements of both instruments yields an average deviation in the retrieved daily means of ≤0.2% for CO2. For CH4 an average bias between the instruments of 0.46% was observed. For test cases, spectra recorded by the high resolution instrument have been truncated to the resolution of 0.11 cm−1. This study gives an offset of 0.03% for CO2 and 0.26% for CH4. These results indicate that for CH4 more than 50% of the difference between the instruments results from the resolution dependant retrieval. We tentatively assign the offset to an incorrect a-priori concentration profile or the effect of interfering gases, which may not be treated correctly.
A new concept for simulation of vegetated land surface dynamics – Part 1: The event driven phenology model
Authors: Kovalskyy V. , Henebry G. M.
Published: January 2012

Abstract. Phenologies of the vegetated land surface are being used increasingly for diagnosis and prognosis of climate change consequences. Current prospective and retrospective phenological models stand far apart in their approaches to the subject. We report on an exploratory attempt to implement a phenological model based on a new event driven concept which has both diagnostic and prognostic capabilities in the same modeling framework. This Event Driven Phenological Model (EDPM) is shown to simulate land surface phenologies and phenophase transition dates in agricultural landscapes based on assimilation of weather data and land surface observations from spaceborne sensors. The model enables growing season phenologies to develop in response to changing environmental conditions and disturbance events. It also has the ability to ingest remotely sensed data to adjust its output to improve representation of the modeled variable. We describe the model and report results of initial testing of the EDPM using Level 2 flux tower records from the Ameriflux sites at Mead, Nebraska, USA, and at Bondville, Illinois, USA. Simulating the dynamics of normalized difference vegetation index based on flux tower data, the predictions by the EDPM show good agreement (RMSE < 0.08; r2 > 0.8) for maize and soybean during several growing seasons at different locations. This study presents the EDPM used in the companion paper (Kovalskyy and Henebry, 2011) in a coupling scheme to estimate daily actual evapotranspiration over multiple growing seasons.
Alternative methods to predict actual evapotranspiration illustrate the importance of accounting for phenology – Part 2: The event driven phenology model
Authors: Kovalskyy V. , Henebry G. M.
Published: January 2012

Abstract. Evapotranspiration (ET) flux constitutes a major component of both the water and energy balances at the land surface. Among the many factors that control evapotranspiration, phenology poses a major source of uncertainty in attempts to predict ET. Contemporary approaches to ET modeling and monitoring frequently summarize the complexity of the seasonal development of vegetation cover into static phenological trajectories (or climatologies) that lack sensitivity to changing environmental conditions. The Event Driven Phenology Model (EDPM) offers an alternative, interactive approach to representing phenology. This study presents the results of an experiment designed to illustrate the differences in ET arising from various techniques used to mimic phenology in models of land surface processes. The experiment compares and contrasts two realizations of static phenologies derived from long-term satellite observations of the Normalized Difference Vegetation Index (NDVI) against canopy trajectories produced by the interactive EDPM trained on flux tower observations. The assessment was carried out through validation of predicted ET against records collected by flux tower instruments. The VegET model (Senay, 2008) was used as a framework to estimate daily actual evapotranspiration and supplied with seasonal canopy trajectories produced by the EDPM and traditional techniques. The interactive approach presented the following advantages over phenology modeled with static climatologies: (a) lower prediction bias in crops; (b) smaller root mean square error in daily ET – 0.5 mm per day on average; (c) stable level of errors throughout the season similar among different land cover types and locations; and (d) better estimation of season duration and total seasonal ET.
Paleoenvironmental imprint on subseafloor microbial communities in Western Mediterranean Sea Quaternary sediments
Authors: Ciobanu M.-C. , Rabineau M. , Droz L. , Révillon S. , Ghiglione J.-F. , Dennielou B. , Jorry S.-J. , Kallmeyer J. , Etoubleau J. , Pignet P. , Crassous P. , Vandenabeele-Trambouze O. , Laugier J. , Guégan M. , Godfroy A. , Alain K.
Published: January 2012

Abstract. An interdisciplinary study was conducted to evaluate the relationship between geological and paleontological parameters and the bacterial and archaeal community structure of two contrasted subseafloor sites in the Western Mediterranean Sea (Ligurian Sea and Gulf of Lions). Since both depositional environments were well-documented in this area, large data-sets were available and allowed to calibrate the investigated cores with several reference and dated cores previously collected in the same area, and notably correlated to Quaternary climate variations. Molecular-based fingerprints showed that the Ligurian Sea sediments, characterized by an heterolithic facies with numerous turbidites from a deep-sea levee, were unexpectedly dominated by Betaproteobacteria (more than 70 %), at the base of the core mainly below five meters in the sediment. Analysis of relative betaproteobacterial abundances and turbidites frequency indicated that the microbial diversity was controlled by the important climatic changes occurring during the last 20 ka. This result was supported by statistical direct multivariate canonical correspondence analyses (CCA). In contrast, the Gulf of Lions core, characterized by a homogeneous lithology of upper-slope environment, was dominated by the Bacteroidetes group and in a lesser extent, by the Betaproteobacteria group. At both sites, the dominance of Betaproteobacteria coincided with increased terrestrial inputs, as confirmed by the geochemical measurements (Si, Sr, Ti and Ca). In the Gulf of Lions, geochemical parameters were also found to drive microbial community composition. Taken together, our data suggest that the palaeoenvironmental history of erosion and deposition recorded in the Western-Mediterranean Sea sediments has left its imprint on the structure/composition of the microbial communities during the late Quaternary.
Watershed discretization based on multiple factors and its application in the Chinese Loess Plateau
Authors: Xu Y. D. , Fu B. J. , He C. S. , Gao G. Y.
Published: January 2012

Abstract. The spatial discretization of watersheds is an indispensable procedure for representing landscape variations in eco-hydrological research, representing the contrast between reality and data-supported models. When discretizing a watershed, it is important to construct a scheme of a moderate number of discretized factors while adequately considering the actual eco-hydrological processes, especially in regions with unique eco-hydrological features and intense human activities. Because of their special lithological and pedologic characteristics and widespread man-made vegetation, discretization of watersheds in the Loess Plateau in Northern China is a challenge. In order to simulate the rainfall-runoff process, a watershed in the Loess Plateau, referred as Ansai, was spatially discretized into new units called land type units. These land type units were delineated under a scheme of factors including land use, vegetation condition, soil type and slope. Instead of using units delineated by overlaying land use and soil maps, the land type units were used in the Soil and Water Assessment Tool (SWAT). Curve numbers were assigned and adjusted to simulate runoff, using the US Natural Resources Conservation Service (NRCS) curve number method. The results of the runoff simulation better matched actual observations. Compared to the results that used the original units, the coefficient of determination (R2) and the Nash-Sutcliffe coefficient (ENS) for monthly flow simulation increased from 0.655–0.713 and 0.271–0.550 to 0.733–0.745 and 0.649–0.703, respectively. This method of delineating into land type units is an easy operation and suitable approach for eco-hydrological studies in the Chinese Loess Plateau and other similar regions. It can be further applied in soil erosion simulation and the eco-hydrological assessment of re-vegetation.