bluuebunny/crossref_metadata_2025 huggingface dataset:
Health record systems that meet clinical needs
Authors: Negrini Gabriella
Published: April 2013

Introduction Increased attention has recently been focused on health record systems as a result of accreditation programs, a growing emphasis on patient safety, and the increase in lawsuits involving allegations of malpractice. Health-care professionals frequently express dissatisfaction with the health record systems and complain that the data included are neither informative nor useful for clinical decision making. This article reviews the main objectives of a hospital health record system, with emphasis on its roles in communication and exchange among clinicians, patient safety, and continuity of care, and asks whether current systems have responded to the recent changes in the Italian health-care system.Discussion If health records are to meet the expectations of all health professionals, the overall information need must be carefully analyzed, a common data set must be created, and essential specialist contributions must be defined. Working with health-care professionals, the hospital management should define how clinical information is to be displayed and organized, identify a functionally optimal layout, define the characteristics of ongoing patient assessment in terms of who will be responsible for these activities and how often they will be performed. Internet technology can facilitate data retrieval and meet the general requirements of a paper-based health record system, but it must also ensure focus on clinical information, business continuity, integrity, security, and privacy.Conclusions The current health records system needs to be thoroughly revised to increase its accessibility, streamline the work of health-care professionals who consult it, and render it more useful for clinical decision making—a challenging task that will require the active involvement of the many professional classes involved.
Internal medicine and complex patient: considerations of an internist
Authors: D’Amore Francesco
Published: April 2013

Not available
Epidemiology of comorbidities in chronic obstructive pulmonary disease: clusters, phenotypes and outcomes
Authors: Aryala Shambhu , Diaz-Guzmana Enrique , Manninoa David M.
Published: April 2013

COPD is a complex multisystem disease often accompanied by multiple co-morbidities that contribute to symptoms, exacerbations, hospital admissions and mortality. Individual comorbidities can be grouped into clusters of common human pathology: inflammation/immune response (e.g., ischemic heart disease, metabolic syndrome), thrombosis/hemorrhage (e.g., cerebrovascular diseases, pulmonary embolism), fibrosis/cell proliferation (e.g., lung cancer and other malignancies) and apoptosis/necrosis (e.g., osteoporosis, skeletal muscle dysfunction). While the prevalence of the co-morbidities has been described in a number of observational studies, there is considerable variability in results; moreover characterization of cluster of co-morbidities with the most clinical significance in terms of morbidity and mortality is still lacking. Pathological mechanisms underlying some of the identified clusters are well known; others need further clarification to identify possible preventative strategies. Treatment of COPD must include management of the underlying co-morbidities for best outcomes.
Hypertension in the elderly
Authors: Pinna Giuliano , Pascale Claudio , La Regina Micaela , Orlandini Francesco
Published: April 2013

IntroductionThere is a high prevalence of hypertension in the elderly, as evidenced by clinical and health behavioral policies. Still, there are uncertainties on the treatment of hypertension, especially treatment of the very elderly. These considerations have largely been ignored in clinical trials due to concern regarding contamination by other pathologies that are difficult to frame and manage.Methods We performed an effective and ample literature review and provided reflections on the Consensus Conference ACCF/AHA 2011 on the principle types of hypertension found in the elderly. We also considered the associated principle pathologies for various treatments and related organs.Discussion Even if the goal of treatment of elevated blood pressure in the elderly is same as in younger population, it is no longer certain that a target systolic blood pressure (SBP) <140 mmHg should be persistently reached in the very elderly. It is important to note that for all studies these values have never been reached. In the treatment of isolated systolic hypertension (ISH) the preferred target is a SBP >160 mmHg. Treating hypertension in the elderly and very elderly reduces the risk of stroke and heart failure, though the evidence is inconclusive for all-cause mortality.Conclusion Hypertension in the elderly is very common and needs to be treated with criteria that consider the patient's age, comorbidities, lifestyle and adherence. Above all, in the very elderly, therapeutic treatment should be personalized according to the above criteria. Where possible pharmaceutical therapy should be limited at the preference of healthy lifestyle changes (physical activity, diet, etc.).
Eosinophilic gastroenteritis: a case report and review of the literature
Authors: Biagi Paolo , Abate Luigi , Mellone Carmine , Salvadori Stefania , Peccetti Andrea , Ginori Alessandro
Published: April 2013

BackgroundEosinophilic gastroenteritis (EoG) is a rare disease of unknown etiology characterized by patchy or diffuse eosinophilic infiltration of the gastrointestinal tract wall. As clinical presentation and endoscopic/ radiological findings are nonspecific, diagnosis may only be ascertained by histologic findings.Clinical case This article presents a case of EoG with associated colonic involvement but without peripheral eosinophilia. Although no allergy could be demonstrated, the clinical symptoms and histologic pattern of diffuse eosinophilic mucosal infiltration disappeared after steroid therapy, as discovered by a careful endoscopic follow-up.Discussion Current concepts of this complex disorder and a review of the literature are presented.
Proposal of early retreatment with iloprost in partially responsive patients with bone marrow edema syndrome: a case report
Authors: Meini Simone , Panigada Grazia
Published: April 2013

Background Avascular Necrosis (AVN) is defined as the cellular death of bone components due to an alteration of the blood supply, resulting in Edema of the Bone Marrow (BME), structural collapse and bone destruction. In advanced stages, AVN requires surgery. One emerging medical treatment for supporting osseous perfusion is the administration of iloprost.Materials and methods A 38-year-old woman presented with severe BME of the left hip (primary), persisting for 6 weeks. She was treated with iloprost iv at 2 ng/kg/min for 6 hours/day for 5 days, and after 4 weeks, the treatment was repeated at 1.5 ng/kg/min for 6 hours for 5 days because she exhibited only a partial response to the first treatment. Complete remission was obtained, documented clinically and on Magnetic Resonance Imaging (MRI). Her Harris Hip Score (HHS) increased from 29.90 to 97. No significant adverse events related to iloprost were registered. No surgical procedures were necessary.Conclusions In most cases, iloprost is administered in a single cycle of treatment over 5 days at 1-2 ng/kg/min for 6 hours/day, but no research has investigated the effectiveness of early retreatment after the first cycle results in only a partially response. Only a few studies examining small numbers of patients have evaluated iloprost in AVN/BME, preferring, in most cases, the dose of 1 ng/kg/min and obtaining clinical improvement both in BME and in AVN in times comparable to surgical core decompression. This case report demonstrates the safety and effectiveness of early repetition of the maximal dose of iloprost before BME evolves into AVN, as well as in cases initially appearing serious and requiring surgical procedures.
A structured approach to medical comanagement of surgical patients
Authors: Siegal Eric
Published: April 2013

Comanagement is defined as shared responsibility, authority and accountability for the management of a hospitalized patient, and represents a fundamentally different model from traditional medical consultation. Medical comanagement has rapidly proliferated and is now a dominant model of care in American hospitals. Comanagement is most effective when patients are appropriately selected, processes are predetermined and systems are implemented to ensure rigorous and continuous improvement. This article provides a structured approach for conceptualizing and implementing medical comanagement.
Management of Health-Care Associated Pneumonia (HCAP)
Authors: Rosato Alessia , Santini Claudio
Published: April 2013

Introduction The traditional classification of Pneumonia as either community acquired (CAP) or hospital acquired (HAP) reflects deep differences in the etiology, pathogenesis, approach and prognosis between the two entities. Health-Care Associated Pneumonia (HCAP) develops in a heterogeneous group of patients receiving invasive medical care or surgical procedures in an outpatient setting. For epidemiology and outcomes, HCAP closely resembles HAP and possibly requires an analogous therapeutic regimen effective against multidrug-resistant pathogens. Materials and methods We reviewed the pertinent literature and the guidelines for the diagnosis and management of HCAP to analyze the evidence for the recommended approach. Results Growing evidence seems to confirm the differences in epidemiology and outcome between HCAP and CAP but fails to confirm any real advantage in pursuing an aggressive treatment for all HCAP and CAP patients. Discussion Further investigations are needed to establish the optimal treatment approach according to the different categories of patients and the different illness severities. Keywords Health Care Associated Pneumonia (HCAP); Community Acquired Pneumonia (CAP); Hospital Acquired Pneumonia (HAP); Multidrug-resistant (MDR) Pathogens
Hypertonic saline solution and high-dose furosemide infusion in cardiorenal syndrome: our experience
Authors: Ventrella Francesco , Cappello Sergio , Minafra Graziano , Pipino Maria , Carbone Mattea , Insalata Maria , Caccetta Luigi , Iamele Luigi
Published: April 2013

Introduction Heart failure is frequently complicated by renal failure, and this association is a negative prognostic factor. These patients sometimes present oligo-/anuria and resistance to high-dose furosemide, a condition referred to as the cardiorenal syndrome (CRS). Acute or chronic reductions in left ventricular function result in decreased blood flow, with reduction of renal perfusion and activation of several neurohormonal systems, which cause resistance to diuretic therapy. This condition often requires ultrafiltration, which is an effective, but invasive and expensive procedure. Infusions of hypertonic saline solution (HSS) and high-dose furosemide can be an effective alternative. Materials and methods From November 2009 through May 2010, our team treated 20 patients with CRS and resistance to iv boluses of high-dose furosemide. These patients were treated with small-volume (150-250 mL) infusions of HSS (NaCl 1.57 – 4.5%, depending on serum Na values) and high-dose furosemide twice a day. The aim of this treatment is to modify renal hemodynamics and the water-saline balance in the kidney by counteracting the extracellular fluid accumulation and eliminating symptoms of congestion. Results In 18 patients (90%), urine output was restored and renal function improved during the first hours of treatment. Clinical improvement was evident from the first day of therapy, and there were no adverse events. Two patients (10%) did not respond to the treatment: one (who had been in critical condition since admission) died; the other required regular sessions of ultrafiltration. Conclusions HSS combined with high-dose furosemide is a safe, effective, low-cost approach to the treatment of CRS that is resistant to diuretic therapy.
Present and future management of anti-neutrophil cytoplasmic antibody associated vasculitis: how therapy changed the prognosis
Authors: L’Andolina Massimo , Forte Giovanni , Marigliano Norma M. , Galasso Salvatore , Mazzei Francesca , Galasso Domenico
Published: April 2013

Anti-neutrophil cytoplasmic antibody associated vasculitis is part of a multi-systemic idiopathic, small vessel pouci-immune vasculitis. Given the heterogeneous spectrum of the disease, and the need to update therapeutic protocols, the aim of this review was to evaluate clinical-diagnostic approaches. We examined statistical data available in the literature, in particular the 2010 review of St. Hamour et al. Management of Anca-associated Vasculitis, published in Therapeutics and Clinical Risk Management. Acute immunosuppressive therapy and long-term maintenance, with the use of prednisolone, have significantly changed the prognosis of this disease, particularly compared with the 1970s before the introductions of steroids and cyclophosphamide. New drugs such as rituximab, monoclonal antibodies and other modulating immune system molecules are entering clinical use, and experience will confirm whether or not therapeutic guidelines are appropriate. The current diagnostic tools, ranging from laboratory and autoimmune tests, chest X-ray, broncho-alveolar lavage to capillaroscopy, allow prompt diagnosis and early treatment through a first phase of induction-remission, and a second phase of maintenance. There are, however, recurrent and refractory forms of the disease that require long-term immunosuppression and further research into this is merited. These issues have continued to drive the search for safer and more effective modulation of the immune system using targeted immunotherapy. However, the treatment limitations of incomplete efficacy, infection, and cumulative toxicity persist. Modifications to traditional treatment protocols by the use of azathioprine or methotrexate rather than cyclophosphamide, and the introduction of newer agents, such as rituximab, have meant that outcomes have been maintained while toxicity has been reduced.
The internist in the surgical setting: results from the Italian FADOI-ER survey
Authors: Gilioli Fabio , Di Donato Carlo , Ferrari Vincenzo , Bertesi Marcello , Chesi Giuseppe
Published: April 2013

More and more frequently, patients admitted to surgical wards present characteristics similar to those admitted to medical units. They are fragile patients, often elderly, with significant comorbidity. In recent years, to address these emerging clinical issues in a surgical setting, different organizational models involving specialists of different backgrounds were studied, and in particular involving internists and geriatricians. To widen our current knowledge, in 2011 the Federation of Associations of Hospital Doctors on Internal Medicine of Emilia-Romagna, northern Italy (FADOI-ER), proposed a questionnaire to the public healthcare internal medicine departments of the Emilia Romagna region to collect information as to in what way and to what extent internists are involved in the management of surgical patients. In this article, we analyze the results of the questionnaire and make some organizational considerations and proposals. The questionnaire was very simple, consisting of 14 items. The survey was conducted from 1-28 February 2011. Replies were received from 20 internal medicine departments of a total of 75 in the Emilia Romagna region. The FADOI-ER survey has some limitations, the first of which is that only just under 25% of internal medicine departments in the Emilia Romagna region took part. However, the results are still interesting and seem to suggest that internists, because of their particular cultural background and training, could be the preferred partners for comanagement within the context of inpatient surgical procedures. The results of the FADOI-ER questionnaire are also consistent with the data reported in literature and daily clinical experience that highlight the need for a more multi-specialist approach to patient management with medical internists. Further studies will help provide answers as to the best way to conduct this multidisciplinary approach that could represent one of the future challenges for healthcare.
Multiple abdominal nodules in a patient with ulcerative proctitis: a case of peritoneal splenosis
Authors: Marocchi Margherita , Ascari Elisabetta , Boni Maria Chiara , Marani Barbara , Cartelli Concetto , Bollino Ruggero , Rossi Francesco , Fornaciari Giovanni
Published: April 2013

A 40-year old gardener was referred for ulcerative proctitis treated with topical mesalamine with rapid improvement of symptoms. Eighteen years before he had had a splenectomy for traumatic splenic rupture. At the end of 2010, he was admitted to another hospital because of abdominal pain. Computerized tomography (CT) scan and magnetic resonance imaging revealed multiple abdominal nodules but a definite diagnosis was not made. While being examined for the proctitis, the patient was admitted to our unit due to worsening of the abdominal pain. After another CT scan, a laparoscopy was performed: several reddish-blue nodules on the peritoneal wall were observed and biopsies were performed. Histological examination was consistent with splenosis. After the procedure, we observed an improvement in the abdominal pain. Splenosis is an acquired condition defined as autotransplantation of viable splenic tissue throughout different sites of the body. It occurs after splenic rupture via trauma or surgery. Splenosis is a benign condition that is usually found incidentally unless symptomatic. Since on radiographic examination it can mimic a neoplasia, extensive workup is usually needed. The diagnostic method of choice is nuclear scintigraphy. Splenosis usually occurs in the abdominal and pelvic cavities but patients have been described with splenosis in other intrathoracic, hepatic and subcutaneous sites. Splenosis is usually asymptomatic and treatment is not necessary. Most patients who have an exploratory laparotomy or laparoscopy for abdominal pain, such as in our patient, experience no more pain after the procedure, regardless of whether the splenic nodules have been completely removed or not. The reason for this spontaneous improvement is not known.
Factors affecting the performance of professional nurses in Namibia
Authors: Awases Magdalene H. , Bezuidenhout Marthie C. , Roos Janetta H.
Published: April 2013

Background: Professional nurses play a vital role in the provision of health care globally. The performance of health care workers, including professional nurses, link closely to the productivity and quality of care provision within health care organisations. It was important to identify factors influencing the performance of professional nurses if the quality of health care delivery was to improved.Objectives: The aim of the present study was to identify factors affecting the performance of professional nurses in Namibia.Method: A quantitative, descriptive survey was used to collect data by means of a questionnaire. A random sample of 180 professional nurses was selected from six hospitals in three regions of Namibia.Results: Factors affecting the performance of nurses negatively were identified such as: lack of recognition of employees who are performing well, quality performance outcomes and an absence of a formal performance appraisal system and poor working conditions. Various factors contribute to both the positive and negative performance of professional nurses in Namibia. Strategies were developed for addressing the negative factors that could positively affect the performance of professional nurses in Namibia.Conclusions: This study emphasises the importance of developing strategies to promote the performance of nurses; build knowledge and expertise; develop mechanisms for improving the performance of nurses; expand leadership and management capacity; and generate information and knowledge through research.
Basilar skull fracture in a Thoroughbred colt: Radiography or computed tomography?
Authors: Lim Chee Kin , Saulez Montague N. , Viljoen Adrienne , Carstens Ann
Published: April 2013

A two-year-old Thoroughbred colt was presented to the Equine Clinic, Onderstepoort Veterinary Academic Hospital for head trauma after rearing and falling backwards, hitting his head on the ground. Following medical therapy for acute onset neurological impairment secondary to a suspected basilar skull fracture, the horse was anaesthetised and computed tomography of the skull was performed. A diagnosis of a comminuted basilar skull fracture was made and skull radiographs were taken for comparison. The horse was subsequently euthanased owing to the poor prognosis; necropsy findings were compatible with imaging findings. The value and limitation of computed tomography versus radiography for the diagnosis of basilar skull fracture are discussed in this report.
The diversity of South African spiders (Arachnida: Araneae: Documenting a National Survey).
Authors: Dippenaar-Schoeman Ansie , Van den Berg Almie , Lyle Robin , Haddad Charles , Foord Stefan , Lotz Leon
Published: April 2013

The South African National Survey of Arachnida (SANSA) was initiated in 1997 by the Agricultural Research Council (ARC), with the main aim of documenting the Arachnid fauna of South Africa at a national level. Through their Endangered Species Programme, the South African National Biodiversity Institute (SANBI) came on board for the project’s second phase, called SANSA II, from 2006 to 2010, in partnership with the ARC. During this four-year project an attempt was made to consolidate all available data on South African spiders into one database. This data was used to determine the spatial coverage of the already available data, and to determine where ‘gaps’ in the data lie to identify priority areas for focused field work. Due to extensive collecting done by SANSA field work managers, specimen bycatches from other research projects, student projects, and through public participation in collecting specimens, more than 40 degree square grids were sampled in previously poorly sampled areas. This effort has provided valuable material that has improved our knowledge of the distribution of species, and provided specimens for future taxonomic studies. All this data was used to compile the First Atlas of the Spider Species of South Africa, including georeferenced locality data, distribution maps and information on the level of endemicity of each species. Following SANSA II, 71 spider families, 471 genera and 2028 species are presently known in South Africa. The third phase of SANSA started in 2011 and several actions, such as Red Listing of species, a handbook series for all the biomes, publication of the atlas, and description of new species are underway.
Global patterns in oceanic planktonic metabolism
Authors: Regaudie-de-Gioux Aurore , Duarte Carlos M.
Published: April 2013

Rates of gross primary production (GPP) and respiration (CR) of plankton communities in the upper ocean were evaluated on the basis of a data set comprising 3149 paired light and dark bottle measurements of volumetric GPP‐CR of euphotic zone plankton communities. The data were from 72 published and unpublished reports of measurements made between 1981 and 2011 from the open ocean and the Mediterranean Sea. The data set is dominated by measurements in chlorophyll a (Chl a)‐rich oceans and North Atlantic waters, with a paucity of measurements in the Indian Ocean and South Pacific Ocean. CR scaled as the 3/4 power of GPP with a power slope of 0.79 ± 0.01, implying that the threshold GPP separating heterotrophic from autotrophic plankton communities is 1.26 mmol O2 m−3 d−1. Plankton communities with Chl a < 0.35 mg m−3 tend to be heterotrophic. Both GPP and CR declined exponentially with depth, but the GPP declined faster, at 42% ± 7% m−1, than CR (29% ± 8% m−1), so that CR increases relative to GPP with depth.
Kinetics of manganese adsorption, desorption, and oxidation in coastal marine sediments
Authors: Richard Dominique , Sundby Bjørn , Mucci Alfonso
Published: April 2013

Ejection of excavated manganese (Mn)‐laden particles from anoxic subsurface sediment onto an oxic sediment‐water interface by infauna and by other physical disturbances triggers desorption and oxidation of reduced manganese species. These competing reactions determine whether adsorbed Mn(II) will be desorbed and escape into the water column or be oxidized to Mn(IV) and retained as an insoluble component of the sediment. Consequently, the net flux of Mn(II) to the water column depends on the relative rates of the two reactions. We determined the rates of Mn(II) adsorption, desorption, and oxidation by incubating slurries of natural anoxic sediment at 25°C and monitoring the concentration of manganese in the aqueous phase of the slurry. The kinetics of adsorption, desorption, and oxidation were fitted to first‐order rate laws. The first‐order rate constants for adsorption ( = 7.0 ± 3.4 h−1) and desorption ( = 12.7 ± 3.3 h−1) are more than two orders of magnitude greater than the first‐order rate constant for oxidation ( = 0.020 ± 0.006 h−1). The combination of rapid desorption kinetics and slow oxidation kinetics allows dissolved manganese to be dispersed into the bottom water by turbulent diffusion and escape local reoxidation and retention at the sediment‐water interface. Thus, advection of anoxic sediment to the sediment‐water interface contributes to the overall flux of manganese from the sediment to the water column.
Urediospores of rust fungi are ice nucleation active at > −10 °C and harbor ice nucleation active bacteria
Authors: Morris C. E. , Sands D. C. , Glaux C. , Samsatly J. , Asaad S. , Moukahel A. R. , Gonçalves F. L. T. , Bigg E. K.
Published: April 2013

Abstract. Various features of the biology of the rust fungi and of the epidemiology of the plant diseases they cause illustrate the important role of rainfall in their life history. Based on this insight we have characterized the ice nucleation activity (INA) of the aerially disseminated spores (urediospores) of this group of fungi. Urediospores of this obligate plant parasite were collected from natural infections of 7 species of weeds in France, from coffee in Brazil and from field and greenhouse-grown wheat in France, the USA, Turkey and Syria. Immersion freezing was used to determine freezing onset temperatures and the abundance of ice nuclei in suspensions of washed spores. Microbiological analyses of spores from France, the USA and Brazil, and subsequent tests of the ice nucleation activity of the bacteria associated with spores were deployed to quantify the contribution of bacteria to the ice nucleation activity of the spores. All samples of spores were ice nucleation active, having freezing onset temperatures as high as −4 °C. Spores in most of the samples carried cells of ice nucleation-active strains of the bacterium Pseudomonas syringae (at rates of less than 1 bacterial cell per 100 urediospores), but bacterial INA accounted for only a small fraction of the INA observed in spore suspensions. Changes in the INA of spore suspensions after treatment with lysozyme suggest that the INA of urediospores involves a polysaccharide. Based on data from the literature, we have estimated the concentrations of urediospores in air at cloud height and in rainfall. These quantities are very similar to those reported for other biological ice nucleators in these same substrates. However, at cloud level convective activity leads to widely varying concentrations of particles of surface origin, so that mean concentrations can underestimate their possible effects on clouds. We propose that spatial and temporal concentrations of biological ice nucleators active at temperatures > −10 °C and the specific conditions under which they can influence cloud glaciation need to be further evaluated so as to understand how evolutionary processes could have positively selected for INA.
Cloud-Aerosol-Radiation (CAR) ensemble modeling system
Authors: Liang X.-Z. , Zhang F.
Published: April 2013

Abstract. A Cloud-Aerosol-Radiation (CAR) ensemble modeling system has been developed to incorporate the largest choices of alternative parameterizations for cloud properties (cover, water, radius, optics, geometry), aerosol properties (type, profile, optics), radiation transfers (solar, infrared), and their interactions. These schemes form the most comprehensive collection currently available in the literature, including those used by the world leading general circulation models (GCMs). The CAR provides a unique framework to determine (via intercomparison across all schemes), reduce (via optimized ensemble simulations), and attribute specific key factors for (via physical process sensitivity analyses) the model discrepancies and uncertainties in representing greenhouse gas, aerosol and cloud radiative forcing effects. This study presents a general description of the CAR system and illustrates its capabilities for climate modeling applications, especially in the context of estimating climate sensitivity and uncertainty range caused by cloud-aerosol-radiation interactions. For demonstration purpose, the evaluation is based on several CAR standalone and coupled climate model experiments, each comparing a limited subset of the full system ensemble with up to 896 members. It is shown that the quantification of radiative forcings and climate impacts strongly depends on the choices of the cloud, aerosol and radiation schemes. The prevailing schemes used in current GCMs are likely insufficient in variety and physically biased in a significant way. There exists large room for improvement by optimally combining radiation transfer with cloud property schemes.
The covariation of Northern Hemisphere summertime CO2 with surface temperature at boreal latitudes
Authors: Wunch D. , Wennberg P. O. , Messerschmidt J. , Parazoo N. , Toon G. C. , Deutscher N. M. , Keppel-Aleks G. , Roehl C. M. , Randerson J. T. , Warneke T. , Notholt J.
Published: April 2013

Abstract. We observe significant interannual variability in the strength of the seasonal cycle drawdown in northern midlatitudes from measurements of CO2 made by the Total Carbon Column Observing Network (TCCON) and the Greenhouse Gases Observing Satellite (GOSAT). This variability correlates with surface temperature in the boreal latitudes. The TCCON measurements give an average covariation between the XCO2 seasonal cycle minima and boreal surface temperature of 1.3 ± 0.7 ppm K−1. Assimilations from CarbonTracker 2011 and CO2 simulations using the Simple Biosphere exchange Model (SiB) transported by GEOS-Chem underestimate this covariation. Both atmospheric transport and biospheric activity contribute to the observed covariation.
Deuterium fractionation in formaldehyde photolysis: chamber experiments and RRKM theory
Authors: Nilsson E. J. K. , Schmidt J. A. , Johnson M. S.
Published: April 2013

Abstract. While isotope effects in formaldehyde photolysis are the key link between the δD of methane emissions with the δD of atmospheric in situ hydrogen production, the mechanism and the extent of their pressure dependencies is not adequately described. The pressure dependence of the photolysis rates of the mono- and di-deuterated formaldehyde isotopologues HDCO and D2CO relative to the parent isotopologue H2CO was investigated using RRKM theory and experiment. D2CO and H2CO were photolysed in a static reaction chamber at bath gas pressures of 50, 200, 400, 600 and 1000 mbar; these experiments compliment and extend our earlier work with HDCO vs. H2CO. The UV lamps used for photolysis emit light at wavelengths that mainly dissociate formaldehyde into molecular products, CO and H2 or D2. A model was constructed using RRKM theory to calculate the lifetime of excited formaldehyde on the S0 surface to describe the observed pressure dependent photolytic fractionation of deuterium. The effect of deuteration on the RRKM lifetime of the S0 state is not the main cause of the experimentally observed isotope effect. We propose that there is an additional previously unrecognised isotopic fractionation in the rate of transfer of population from the initially excited S1 state onto the S0 surface.
Influence of observed diurnal cycles of aerosol optical depth on aerosol direct radiative effect
Authors: Arola A. , Eck T. F. , Huttunen J. , Lehtinen K. E. J. , Lindfors A. V. , Myhre G. , Smirnov A. , Tripathi S. N. , Yu H.
Published: April 2013

Abstract. The diurnal variability of aerosol optical depth (AOD) can be significant, depending on location and dominant aerosol type. However, these diurnal cycles have rarely been taken into account in measurement-based estimates of aerosol direct radiative forcing (ADRF) or aerosol direct radiative effect (ADRE). The objective of our study was to estimate the influence of diurnal aerosol variability on the top of the atmosphere ADRE estimates. By including all the possible AERONET sites, we wanted to assess the influence on global ADRE estimates, while by focusing also in more detail on some selected sites of strongest impact, our goal was to also see the possible impact regionally. We calculated ADRE with different assumptions about the daily AOD variability: taking the observed daily AOD cycle into account and assuming diurnally constant AOD. Moreover, we estimated the corresponding differences in ADREs, if the single AOD value for the daily mean was taken from the the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra or Aqua overpass times, instead of accounting for the true observed daily variability. The mean impact of diurnal AOD variability on 24 h ADRE estimates, averaged over all AERONET sites, was rather small and it was relatively small even for the cases when AOD was chosen to correspond to the Terra or Aqua overpass time. This was true on average over all AERONET sites, while clearly there can be much stronger impact in individual sites. Examples of some selected sites demonstrated that the strongest observed AOD variability (the strongest morning afternoon contrast) does not typically result in a significant impact on 24 h ADRE. In those cases, the morning and afternoon AOD patterns are opposite and thus the impact on 24 h ADRE, when integrated over all solar zenith angles, is reduced. The most significant effect on daily ADRE was induced by AOD cycles with either maximum or minimum AOD close to local noon. In these cases, the impact on 24 h ADRE was typically around 0.1–0.2 W m−2 (both positive and negative).
Vertical profiling of aerosol particles and trace gases over the central Arctic Ocean during summer
Authors: Kupiszewski P. , Leck C. , Tjernström M. , Sjogren S. , Sedlar J. , Graus M. , Müller M. , Brooks B. , Swietlicki E. , Norris S. , Hansel A.
Published: April 2013

Abstract. Unique measurements of vertical size resolved aerosol particle concentrations, trace gas concentrations and meteorological data were obtained during the Arctic Summer Cloud Ocean Study (ASCOS, http://www.ascos.se), an International Polar Year project aimed at establishing the processes responsible for formation and evolution of low-level clouds over the high Arctic summer pack ice. The experiment was conducted from onboard the Swedish icebreaker Oden, and provided both ship- and helicopter-based measurements. This study focuses on the vertical helicopter profiles and onboard measurements obtained during a three-week period when Oden was anchored to a drifting ice floe, and sheds light on the characteristics of Arctic aerosol particles and their distribution throughout the lower atmosphere. Distinct differences in aerosol particle characteristics within defined atmospheric layers are identified. Near the surface (lowermost couple hundred meters), transport from the marginal ice zone (MIZ), if sufficiently short (less than ca. 2 days), condensational growth and cloud-processing develop the aerosol population. During two of the four representative periods defined in this study, such influence is shown. At altitudes above about 1 km, long-range transport occurs frequently. However, only infrequently does large-scale subsidence descend such air masses to become entrained into the mixed layer in the high Arctic, and therefore they are unlikely to directly influence low-level stratiform cloud formation. Nonetheless, long-range transport plumes can influence the radiative balance of the PBL by influencing formation and evolution of higher clouds, as well as through precipitation transport of particles downwards. New particle formation was occasionally observed, particularly in the near-surface layer. We hypothesize that the origin of these ultrafine particles can be from biological processes, both primary and secondary, within the open leads between the pack ice and/or along the MIZ. In general, local sources, in combination with upstream boundary layer transport of precursor gases from the MIZ, are suggested to constitute the origin of CCN particles and thus be of importance for the formation of interior Arctic low level clouds during summer, and subsequently, through cloud influences, on the melting and freezing of sea ice.
The Atmospheric Mercury Network: measurement and initial examination of an ongoing atmospheric mercury record across North America
Authors: Gay D. A. , Schmeltz D. , Prestbo E. , Olson M. , Sharac T. , Tordon R.
Published: April 2013

Abstract. The National Atmospheric Deposition Program (NADP) developed and operates a collaborative network of atmospheric mercury monitoring sites based in North America – the Atmospheric Mercury Network (AMNet). The justification for the network was growing interest and demand from many scientists and policy makers for a robust database of measurements to improve model development, assess policies and programs, and improve estimates of mercury dry deposition. Many different agencies and groups support the network, including federal, state, tribal, and international governments, academic institutions, and private companies. AMNet has added two high elevation sites outside of continental North America in Hawaii and Taiwan because of new partnerships forged within NADP. Network sites measure concentrations of atmospheric mercury fractions using automated, continuous mercury speciation systems. The procedures that NADP developed for field operations, data management, and quality assurance ensure that the network makes scientifically valid and consistent measurements. AMNet reports concentrations of hourly gaseous elemental mercury (GEM), two-hour gaseous oxidized mercury (GOM), and two-hour particulate-bound mercury less than 2.5 microns in size (PBM2.5). As of January 2012, over 450 000 valid observations are available from 30 stations. The AMNet also collects ancillary meteorological data and information on land-use and vegetation, when available. We present atmospheric mercury data comparisons by time (3 yr) at 22 unique site locations. Highlighted are contrasting values for site locations across the network: urban versus rural, coastal versus high-elevation and the range of maximum observations. The data presented should catalyze the formation of many scientific questions that may be answered through further in-depth analysis and modeling studies of the AMNet database. All data and methods are publically available through an online database on the NADP website (http://nadp.isws.illinois.edu/amn/). Future network directions are to foster new network partnerships and continue to collect, quality assure, and post data, including dry deposition estimates, for each fraction.
Application of linear polarized light for the discrimination of frozen and liquid droplets in ice nucleation experiments
Authors: Clauss T. , Kiselev A. , Hartmann S. , Augustin S. , Pfeifer S. , Niedermeier D. , Wex H. , Stratmann F.
Published: April 2013

Abstract. We report on the development and test results of the new optical particle counter TOPS-Ice (Thermo-stabilized Optical Particle Spectrometer for the detection of Ice). The instrument uses measurements of the cross-polarized scattered light by single particles into the near-forward direction (42.5° ± 12.7°) to distinguish between spherical and non-spherical particles. This approach allows the differentiation between liquid water droplets (spherical) and ice particles (non-spherical) having similar volume-equivalent sizes and therefore can be used to determine the fraction of frozen droplets in a typical immersion freezing experiment. We show that the numerical simulation of the light scattered on non-spherical particles (spheroids in random orientation) considering the actual scattering geometry used in the instrument supports the validity of the approach, even though the cross-polarized component of the light scattered by spherical droplets does not vanish in this scattering angle. For the separation of the ice particle mode from the liquid droplet mode, we use the width of the pulse detected in the depolarization channel instead of the pulse height. Exploiting the intrinsic relationship between pulse height and pulse width for Gaussian pulses allows us to calculate the fraction of frozen droplets even if the liquid droplet mode dominates the particle ensemble. We present test results obtained with TOPS-Ice in the immersion freezing experiments at the laminar diffusion chamber LACIS (Leipzig Aerosol Cloud Interaction Simulator) and demonstrate the excellent agreement with the data obtained in similar experiments with a different optical instrument. Finally, the advantages of using the cross-polarized light measurements for the differentiation of liquid and frozen droplets in the realistic immersion freezing experiments are discussed.
Double cusp encounter by Cluster: double cusp or motion of the cusp?
Authors: Escoubet C. P. , Berchem J. , Trattner K. J. , Pitout F. , Richard R. , Taylor M. G. G. T. , Soucek J. , Grison B. , Laakso H. , Masson A. , Dunlop M. , Dandouras I. , Reme H. , Fazakerley A. , Daly P.
Published: April 2013

Abstract. Modelling plasma entry in the polar cusp has been successful in reproducing ion dispersions observed in the cusp at low and mid-altitudes. The use of a realistic convection pattern, when the IMF-By is large and stable, allowed Wing et al. (2001) to predict double cusp signatures that were subsequently observed by the DMSP spacecraft. In this paper we present a cusp crossing where two cusp populations are observed, separated by a gap around 1° Invariant Latitude (ILAT) wide. Cluster 1 (C1) and Cluster 2 (C2) observed these two cusp populations with a time delay of 3 min, and about 15 and 42 min later Cluster 4 (C4) and Cluster 3 (C3) observed, respectively, a single cusp population. A peculiarity of this event is the fact that the second cusp population seen on C1 and C2 was observed at the same time as the first cusp population on C4. This would tend to suggest that the two cusp populations had spatial features similar to the double cusp. Due to the nested crossing of C1 and C2 through the gap between the two cusp populations, C2 being first to leave the cusp and last to re-enter it, these observations are difficult to be explained by two distinct cusps with a gap in between. However, since we observe the cusp in a narrow area of local time post-noon, a second cusp may have been present in the pre-noon sector but could not be observed. On the other hand, these observations are in agreement with a motion of the cusp first dawnward and then back duskward due to the effect of the IMF-By component.
Impact of global change on coastal oxygen dynamics and risk of hypoxia
Authors: Meire L. , Soetaert K. E. R. , Meysman F. J. R.
Published: April 2013

Abstract. Climate change and changing nutrient loadings are the two main aspects of global change that are linked to the increase in the prevalence of coastal hypoxia – the depletion of oxygen in the bottom waters of coastal areas. However, it remains uncertain how strongly these two drivers will each increase the risk of hypoxia over the next decades. Through model simulations we have investigated the relative influence of climate change and nutrient run-off on the bottom water oxygen dynamics in the Oyster Grounds, an area in the central North Sea experiencing summer stratification. Simulations were performed with a one-dimensional ecosystem model that couples hydrodynamics, pelagic biogeochemistry and sediment diagenesis. Climatological conditions for the North Sea over the next 100 yr were derived from a global-scale climate model. Our results indicate that changing climatological conditions will increase the risk of hypoxia. The bottom water oxygen concentration in late summer is predicted to decrease by 24 μM or 11.5% in the year 2100. More intense stratification is the dominant factor responsible for this decrease (58%), followed by the reduced solubility of oxygen at higher water temperature (27%), while the remaining part could be attributed to enhanced metabolic rates in warmer bottom waters (15%). Relative to these climate change effects, changes in nutrient runoff are also important and may even have a stronger impact on the bottom water oxygenation. Decreased nutrient loadings strongly decrease the probability of hypoxic events. This stresses the importance of continued eutrophication management in coastal areas, which could function as a mitigation tool to counteract the effects of rising temperatures.
Symbiosis increases coral tolerance to ocean acidification
Authors: Ohki S. , Irie T. , Inoue M. , Shinmen K. , Kawahata H. , Nakamura T. , Kato A. , Nojiri Y. , Suzuki A. , Sakai K. , van Woesik R.
Published: April 2013

Abstract. Increasing the acidity of ocean waters will directly threaten calcifying marine organisms such as reef-building scleractinian corals, and the myriad of species that rely on corals for protection and sustenance. Ocean pH has already decreased by around 0.1 pH units since the beginning of the industrial revolution, and is expected to decrease by another 0.2–0.4 pH units by 2100. This study mimicked the pre-industrial, present, and near-future levels of pCO2 using a precise control system (±5% pCO2), to assess the impact of ocean acidification on the calcification of recently-settled primary polyps of Acropora digitifera, both with and without symbionts, and adult fragments with symbionts. The increase in pCO2 of 100 μatm between the pre-industrial period and the present had more effect on the calcification rate of adult A. digitifera than the anticipated future increases of several hundreds of micro-atmospheres of pCO2. The primary polyps with symbionts showed higher calcification rates than primary polyps without symbionts, suggesting that (i) primary polyps housing symbionts are more tolerant to near-future ocean acidification than organisms without symbionts, and (ii) corals acquiring symbionts from the environment (i.e. broadcasting species) will be more vulnerable to ocean acidification than corals that maternally acquire symbionts.