bluuebunny/crossref_metadata_2025 huggingface dataset:
Corrosion Behavior of Ti and Ti Based Alloys Used as Implants-Supported Mandibular Overdentures
Authors: Meghea Daniela , Miculescu Marian , Cotrut Mihai Cosmin , Bane Marin , Gherghilescu A. , Vrânceanu D.M.
Published: March 2015

In the present study, four different types of the commercial dental implants used as support for total/partial dental prosthesis have been investigated. Pure Ti and Ti6Al4V alloy, provided by four different manufactures, were chosen because these were the most used in dentistry market. The corrosion resistance was evaluated by using linear polarization technique, after recording the open circuit curves in Fusayama Meyer artificial saliva for 240 minutes. The corrosion tests in artificial saliva with pH 5.2 have shown that pure Ti exhibited a better behavior than the Ti alloy. This result can be explained by a higher stability of the passive thin layer of titanium oxide than the complex oxide layer formed on the Ti alloy surface.
Hybrid Hydrogels Intended as Scaffolds for Soft Tissue Repair
Authors: Serafim Andrada , Petre Daniela G. , Lungu Adriana , Cioflan Horia Emil , Stancu Izabela Cristina
Published: March 2015

This work describes the investigation of the properties of hydrogels based on methacrylamide-modified gelatin (GelMA) and polyvinylpyrrolidone (PVP) with potential applications in wound treatment. While the semi-natural polymer insures the biocompatibility and biodegradability of the synthesized materials, the synthetic polymer was selected due to its water affinity and interesting mechanical properties. The efficiency of the polymerization process and the stability of the PVP within the semi interpenetrated polymer network (semiIPN) were verified through gel fraction study. The water affinity, tensile strength and rheological properties of the hydrogels were also investigated.
Hydroxyapatite Coating Influenced by Ti6Al4V Substrate Roughness
Authors: Constantinescu Florin , Ciocoiu Robert , Trante Octavian , Ciucă Ion
Published: March 2015

In this paper the author’s main goal was to determine if the roughness of the substrate (a Ti6Al4V alloy) shows any influence on the hydroxyapatite (HA) crystal morphology and distribution. Disks of Ti6Al4V, 24mm in diameter and 1mm thickness are sandblasted with Al2O3particles with different mean size: 29, 45 and 110μm. The disks are analyzed prior coating by atomic force microscopy (AFM) to determine the surface roughness. The samples are then cleaned and coated with HA by immersion in a solution derived from [Ca (NO3)2.4H2O] and P2O5dissolved in ethylene glycol – the process was repeated 3 times. The coated samples are analyzed by scanning electron microscopy (SEM) to observe HA crystal shape, size and distribution.
Mesenchymal Stem Cell Response to Surface Altered Porous Ti
Authors: Salantiu Ana Maria , Popa Florin , Pascuta Petru , Soritau Olga , Dirzu Noemi , Popa Catalin
Published: March 2015

This work aims to investigate the influence of surface conditioning of porous Ti for enhancing its biological activity, as assessed by in vitro stem cell testing. Porous Ti samples with an average porosity of 32% were processed by Powder Metallurgy with dextrin as a space holder. The samples were subjected to H2O2 treatment to form an enhanced TiO2 film, followed by a heat treatment at 400°C and 600°C aiming to the crystallization of the as-formed amorphous titanium oxide. Samples characterization was performed by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and X-Ray Diffraction (XRD). The treated surfaces revealed to be made of both anatase and rutile TiO2, with groove–shaped structure and cracks on the surface of the TiO2 film. The intrinsic biocompatibility of the chemically modified porous Ti surfaces was assessed in vitro. In our cell culture tests, stem cells were found to attach and proliferate better on the chemically treated Ti surfaces compared to the control untreated Ti surfaces.
The Effect of Silver Nanoparticles on the Collagen Secondary Structure
Authors: Drobota Mioara , Grierosu Irena , Radu Iulian , Vasilescu Dan Sorin
Published: March 2015

Attenuated Total Reflection - Fourier Transform Infrared (ATR-FTIR) spectroscopy is a label-free, non-destructive analytical technique that can be used extensively to study a wide variety of molecules in different conditions. Proteins have very complicated three dimensional structures with multi-level conformations, which are highly correlated with their biological activities. Recently, there is a significant increase of materials based on interaction between proteins and nanoparticles. The aim of this paper is to highlight the understanding of protein interaction with silver nanoparticles (AgNPs) surfaces. Information about the secondary structures of collagen with and without AgNPs was obtained from atomic force microscopy (AFM) measurements.ATR-FTIR spectroscopy was used for monitoring the changes in the secondary structures of collagen upon interaction with AgNPs. Amide I is the most sensitive band for detecting changes in the protein secondary structures. Its characteristic absorption band is located at 1600–1700 cm-1. Comparing the spectra of collagen with and without AgNPs in this region, information about the different types of secondary structures such as α-helix, β-sheets, turns and random coil can be obtained. The conjugation of AgNPs-collagen occurred mainly through electrostatic interactions. Based on these data, the effects of AgNPs stability and the conformational changes of collagen upon interaction with the AgNPs are discussed.
Three-Dimensional Nanostructures with Biocidal Activity Created on a Siloxane-Containing Copolyimide Film
Authors: Stoica Iuliana , Barzic Andreea Irina , Aflori Magdalena , Hulubei Camelia , Harabagiu Valeria , Vasilescu Dan Sorin
Published: March 2015

Surface morphological characteristics of a copolyimide film prepared from a fluorine-based dianhydride combined with an aliphatic siloxane-based diamine and an aromatic containing ether linkages one, were studied before and after oxigen plasma treatment using atomic force microscopy (AFM). The three-dimensional texture parameters calculated from the AFM data have highlighted a more pronounced surface morphology (higher average roughness and developed interfacial area ratio), improved bearing properties and no predominant orientation, as the plasma exposure time was increased from 6 to 10 minutes, using the same power (40 W). The reactive groups generated on the binding surface have facilitated the interaction with a biocidal agent, such as silver nitrate. This creates silver-containing nanoparticles, of about 120-150 nm, uniformly distributed on the copolymer surface, with a density of 10±2 particles/μm2. The functionalization with the biocidal agent of the flourinated copolyimide surface was conducted for testing its antimicrobial properties, namely the inhibition/destruction of Escherichia coli bacterium.
Perceptions of professional nurses regarding introduction of the Batho Pele principles in State hospitals
Authors: James Sindiwe , Miza Thenjiwe M.
Published: March 2015

Background: The South African health care delivery system has shifted focus to primary health care since 1994. For this purpose the Batho Pele principles were introduced. Nurses claim, however, that since the introduction of these principles patients and their families have been making unnecessary and sometimes impossible demands of nursing staff. This article presents the perceptions of the professional nurses regarding the introduction of the Batho Pele principles in their workplace.Objectives: To describe the perceptions of professional nurses regarding introduction of the Batho Pele principles and to recommend guidelines to facilitate measures to realise the objects of these principles.Method: A qualitative, exploratory, descriptive and contexual research design was used. Six audio-taped focus group discussions and field notes were used to collect data from purposively sampled participants who have worked in the outpatient departments of hospitals in thePort Elizabeth Hospital Complex. Guba’s model of trustworthiness was used to confirm integrity of the study, whilst the participants were kept anonymous, protected from harm and participated voluntarily. Data analysis was done using Tesch’s data analysis spiral and with the involvement of an independent-coder.Results: Three themes emerged, revealing that the professional nurses perceived the objectives of the Batho Pele principles as difficult to uphold due to the inadequate planning prior to their implementation. Inadequacy of human and material resources aggravated this perception.Conclusion: Professional nurses are not happy with how things are in terms of introduction of the Batho Pele principles, but are optimistic of a positive change in the near future.
Normal Growth of Healthy Infants Born from HIV+ Mothers Fed a Reduced Protein Infant Formula Containing the Prebiotics Galacto-Oligosaccharides and Fructo-Oligosaccharides: A Randomized Controlled Trial
Authors: Da Costa Ribeiro Júnior Hugo , Ribeiro Tereza Cristina Medrado , De Mattos Angela Peixoto , Pontes Mariana , Sarni Roseli Oselka Saccardo , Cruz Maria Letícia Santos , Nogueira-De-Almeida Carlos Alberto , Mussi-Pinhata Marisa M. , De Carvalho Norton Rocksane , Steenhout Philippe
Published: March 2015

Objective

The aim of the current study was to evaluate the safety of a new reduced protein (2.1 g/100 kcal) infant formula containing 4 g/L of 90% galacto-oligosaccharides (GOS) and 10% fructo-oligosaccharides (FOS).

Methods

Healthy term infants from Brazil were enrolled. Those born to human immunodeficiency virus (HIV)-positive mothers were randomized to a test ( n = 65) or control ( n = 63) formula group. Infants born to HIV-negative mothers were either exclusively breast-fed ( n = 79) or received a mixed diet (breast milk and test formula, n = 65). Between 2 weeks and 4 months of age, infants were exclusively fed according to their assigned group. Anthropometric measurements were taken at baseline, 1, 2, 3, 4, 6, 8, 10, and 12 months. Digestive tolerance was evaluated during the first 4 months. The primary outcome was mean daily weight gain between 2 weeks and 4 months in the test formula and breast-fed groups.

Results

Data from all infants ( N = 272) were used in the intention-to-treat (ITT) analysis and data from 230 infants were used in the per-protocol (PP) analysis. The difference in mean daily weight gain between 2 weeks and 4 months in the test formula and breast-fed groups was 1.257 g/day (onesided 95% confidence interval [CI]: -0.705 to inf, P < 0.001) in the PP analysis, showing that the lower bound of the 95% CI was above the -3.0 g/day non-inferiority margin. Results were similar in the ITT analysis. Symptoms of digestive tolerance and frequency of adverse events were similar in the two groups.

Conclusions

The formula containing 2.1 g/100 kcal protein and GOS and FOS was safe and tolerated well.
Awareness regarding Antenatal Investigations among Antenatal Mothers attending Selected Tertiary Hospital, Kochi, Kerala
Authors: Udayan Seethu , Viswanath Lekha , Varghese Linda
Published: March 2015

Background

An antenatal investigation has now literally entered in the domain of prenatal care. Early antenatal investigations help to identify many sorts of medical and infectious diseases during pregnancy and initiate treatment for safeguarding the health of mother and fetus. Many antenatal mothers undergo antenatal investigations without adequate understanding.

Objectives

To identify awareness regarding antenatal investigations among antenatal mothers and to prepare an information booklet on antenatal investigations.

Materials and methods

It is a descriptive study conducted among 180 antenatal mothers attending Obstetrics and Gynecology Outpatient Department in Amrita Institute of Medical Sciences (AIMS) at Kochi. The subjects were selected using quota sampling technique. The trimester was selected as the quota. Sixty women each were selected from first, second and third trimesters. Data were collected using semistructured knowledge questionnaire developed by the investigator.

Results

The mean score of antenatal investigations was 8.96 ± 6.33 with maximum score 19. Among 180 subjects, 61% of antenatal mothers had poor level of awareness regarding antenatal investigations, 63% were belong to first trimester and 64% were primigravida.

Interpretation and conclusion

The study concluded that the level of awareness among antenatal mothers was poor. It is very essential to organize an awareness program to increase the uptake of antenatal investigations.

How to cite this article

Udayan S, Viswanath L, Varghese L. Awareness regarding Antenatal Investigations among Antenatal Mothers attending Selected Tertiary Hospital, Kochi, Kerala. J South Asian Feder Obst Gynae 2014;6(3):129-132.
Selective Fetal Reduction in Triplet Pregnancy: Indian Experience — A Retrospective Review of 32 Cases
Authors: Chaudhury Kalyansree , Mukherjee Kanchan
Published: March 2015

Aim

To review the effects of selective fetal reduction in trichorionic triplet pregnancy with focus on risk of miscarriage and preterm delivery in Indian women and thus provide local data for counseling the prospective parents in similar situation.

Materials and methods

This retrospective study reviewed the pregnancy outcome of 32 sets of triplet pregnancies following fetal reduction. All mothers had trichorionic triplet pregnancy with three live fetuses at 10 to 11 weeks of gestation. One to two milliliter ml of 10% potassium chloride (KCl) was injected into the heart of the target fetus to achieve asystole.

Results

The miscarriage (pregnancy loss before 24 completed weeks) rate in our study was 3.12%. The delivery in our study at. 32 and. 35 weeks were 6.45 and 51.61% respectively. The mean gestational age (mean ± SD) of the mothers was 242.58 ± 12.93 days. Regarding the birthweight of neonates, 5.08% babies were <1500 gm, 89.83% were between 1500 and. 2500 gm and 5.08% were > 2500 gm. The mean birth weight (mean ± SD) of the babies was 1921.18 ± 339.78 gm. There was no neonatal death in this cohort.

Conclusion

Our study results, when compared with ‘expectant management’ group of two European studies as there was no control in our study, appeared significantly better in terms of gestational age at delivery and neonatal birth weight. Selective fetal reduction remains an effective option to Indian women with trichorionic triplet pregnancy.

How to cite this article

Chaudhury K, Mukherjee K. Selective Fetal Reduction in Triplet Pregnancy: Indian Experience — A Retrospective Review of 32 Cases. J South Asian Feder Obst Gynae 2014;6(3):144-150.
Active Management of Third Stage of Labor: A Comparison of Various Uterotonic
Authors: Goel Ruchika , Goel Jai Kishan , Modi Vineeta , Kashyap Anshika , Arya Shashi Bala , Kar Jayanti
Published: March 2015

Aims and objectives

This study was aimed at comparing the various uterotonics in active management of third stage of labor and reducing blood loss.

Materials and methods

A prospective study was conducted in the Department of Obstetrics and Gynecology of SRMSIMS, Bareilly, in 100 women. Patients were randomized into four groups of 25 each and were given oxytocic within 1 minute of delivery of the baby. Oxytocics used were 10 IU intramuscular oxytocin, 0.2 mg intravenous methylergometrine, 125 μg intramuscular 15-methyl PGF2-alpha and 600 μg tablet misoprostol per rectally in groups A, B, C and D respectively.

Results

Duration of third stage of labor recorded was minimum with methergine with mean duration of 3.84 ± 0.99 minutes and was maximum with prostodin with mean duration of 5.04 ± 1.02 minutes. Amount of blood loss observed was minimum with methergine (mean 131 ± 72.037 ml) and maximum with Prostodin (mean 435 ± 147.578 ml). Hemoglobin drop was also seen maximally with prostodin with mean drop of 0.872 ± 0.458 gm% and minimally with methergine with mean drop of 0.236 ± 0.221 gm%. Change in the general condition of the patients in the form of tachycardia, fall in systolic and diastolic blood pressure was observed maximum with prostodin group whereas, in other groups, there was no significant change.

Conclusion

It is concluded from this study that methergine is the uterotonic of choice followed by oxytocin for active management of third stage of labor.

How to cite this article

Modi V, Goel JK, Kashyap A, Arya SB, Kar J, Goel R. Active Management of Third Stage of Labor: A Comparison of Various Uterotonic. J South Asian Feder Obst Gynae 2014;6(3):151-155.
Nontraumatic Epidermoid Inclusion Cyst of Vulva in a Young Unmarried Female: A Rare Entity
Authors: Nagpal Anu , Mohan Praveen
Published: March 2015

Epidermoid inclusion cysts are the most common types of simple dermal epithelial benign lesions, presenting as wellencapsulated subepidermal mobile nodules. They arise on hair-bearing areas but vulva is a rare site. We here report clinical and ultrasonography (USG) findings of a big epidermal nontraumatic inclusion epidermoid cyst at the vulva which was excised and histopathological examination confirmed diagnosis of epidermoid inclusion cyst without any dysplasia.

How to cite this article

Nagpal A, Mohan P, Kaur T. Nontraumatic Epidermoid Inclusion Cyst of Vulva in a Young Unmarried Female: A Rare Entity. J South Asian Feder Obst Gynae 2014;6(3):173-175.
Conjoined Twins with Thoracoabdominopagus Anomaly in the Third Trimester
Authors: Saranya G , Vijayaraghavan Jaya , LNU Bhuvana , LNU Sheela
Published: March 2015

Conjoined twinning is rare; occurrence is about 1% of monochorionic twins. Here, we report a case of 26-year-old multigravida with 29 weeks pregnancy with conjoined twinsthoracoabdominopagus. Two live female babies joined at the chest and abdomen were delivered by cesarean section. The parents refused a separation operation and despite resuscitation the twins died of cardiopulmonary arrest after 16 hours. A review of the literature suggests that early diagnosis by a combination of ultrasound and magnetic resonance imaging is essential for predicting prognosis, management and success of surgical separation. It offers an opportunity for early counseling for parents and option for termination.

How to cite this article

Saranya G, Vijayaraghavan J, Bhuvana, Sheela. Conjoined Twins with Thoracoabdominopagus Anomaly in the Third Trimester. J South Asian Feder Obst Gynae 2014;6(3):191-194.
Effects of age at first access to range area on pecking behaviour and plumage quality of free-range layer chickens
Authors: Petek M. , Topal E. , Cavusoglu E.
Published: March 2015

Abstract. The aim of this study was to investigate the effects of age on pecking behaviour and plumage quality of free-range laying hens during first access to range. Six hundred 16-week-old layer pullets obtained from a commercial company were housed in a experimental free-range house. The experimental house consisted of a slat-and-litter floor with range area and was divided into three similar pens. The pullets were randomly assigned to a control and two experimental groups according to age at first access to range area. The birds were allowed into the range area for the first time at 18, 20 and 22 weeks of age in the groups of treatment I, treatment II and control, respectively. Pecking behaviour and plumage quality of the birds were measured for 8-week intervals from 24 to 48 weeks of age. Total feather damage significantly increased with age in all groups (P < 0.040, P < 0.006, P < 0.001). Compared to the control group, birds allowed into the range area earlier had less feather damage. The feather score of the tail body region in all groups was significantly greater (more damage) than in the others (P < 0.001). There were no significant differences for the total pecking behaviour of the birds in the groups at 24, 32, 40 and 48 weeks of age. Incidents of gentle feather pecking in every period were more frequent, while aggressive pecking was less frequent (P < 0.026, P < 0.007, P < 0.001). It can be said that access to range area as early as possible at the beginning of the laying period may be useful to reduce the negative effect of feather pecking in free-range layer chickens.
Quantification of the depletion of ozone in the plume of Mount Etna
Authors: Surl L. , Donohoue D. , Aiuppa A. , Bobrowski N. , von Glasow R.
Published: March 2015

Abstract. Volcanoes are an important source of inorganic halogen species into the atmosphere. Chemical processing of these species generates oxidised, highly reactive, halogen species which catalyse considerable O3 destruction within volcanic plumes. A campaign of ground-based in situ O3, SO2 and meteorology measurements was undertaken at the summit of Mount Etna volcano in July/August 2012. At the same time, spectroscopic measurements were made of BrO and SO2 columns in the plume downwind. Depletions of ozone were seen at all in-plume measurement locations, with average O3 depletions ranging from 11–35 nmol mol−1 (15–45%). Atmospheric processing times of the plume were estimated to be between 1 and 4 min. A 1-D numerical model of early plume evolution was also used. It was found that in the early plume O3 was destroyed at an approximately constant rate relative to an inert plume tracer. This is ascribed to reactive halogen chemistry, and the data suggests the majority of the reactive halogen that destroys O3 in the early plume is generated within the crater, including a substantial proportion generated in a high-temperature "effective source region" immediately after emission. The model could approximately reproduce the main measured features of the ozone chemistry. Model results show a strong dependence of the near-vent bromine chemistry on the presence or absence of volcanic NOx emissions and suggest that near-vent ozone measurements can be used as a qualitative indicator of NOx emission.
Air quality monitoring in communities of the Canadian Arctic during the high shipping season with a focus on local and marine pollution
Authors: Aliabadi A. A. , Staebler R. M. , Sharma S.
Published: March 2015

Abstract. The Canadian Arctic has experienced decreasing sea ice extent and increasing shipping activity in recent decades. While there are economic incentives to develop resources in the north, there are environmental concerns that increasing marine traffic will contribute to declining air quality in northern communities. In an effort to characterize the relative impact of shipping on air quality in the north, two monitoring stations have been installed in Cape Dorset and Resolute, Nunavut, and have been operational since 1 June 2013. The impact of shipping and other sources of emissions on NOx, O3, SO2, BC, and PM2.5 pollution have been characterized for the 2013 shipping season from 1 June to 1 November. In addition, a high-resolution Air Quality Health Index (AQHI) for both sites was computed. Shipping consistently increased O3 mixing ratio and PM2.5 concentration. The 90% confidence interval for mean difference in O3 mixing ratio between ship- and no ship-influenced air masses were up to 4.6–4.7 ppb and 2.5–2.7 ppb for Cape Dorset and Resolute, respectively. The same intervals for PM2.5 concentrations were up to 1.8–1.9 μg m−3 and 0.5–0.6 μg m−3. Ship-influenced air masses consistently exhibited an increase of 0.1 to 0.3 in the high-resolution AQHI compared to no ship-influenced air masses. Trajectory cluster analysis in combination with ship traffic tracking provided an estimated range for percent ship contribution to NOx, O3, SO2, and PM2.5 that were 12.9–17.5 %, 16.2–18.1 %, 16.9–18.3 %, and 19.5–31.7 % for Cape Dorset and 1.0–7.2 %, 2.9–4.8 %, 5.5–10.0 %, and 6.5–7.2 % for Resolute during the 2013 shipping season. Additional measurements in Resolute suggested that percent ship contribution to black carbon was 4.3–9.8 % and that black carbon constituted 1.3–9.7 % of total PM2.5 mass in ship plumes. Continued air quality monitoring in the above sites for future shipping seasons will improve the statistics in our analysis and characterize repeating seasonal patterns in air quality due to shipping, local pollution, and long-range transport.
Changing shapes and implied viscosities of suspended submicron particles
Authors: Zhang Y. , Sanchez M. S. , Douet C. , Wang Y. , Bateman A. P. , Gong Z. , Kuwata M. , Renbaum-Wolff L. , Sato B. B. , Liu P. F. , Bertram A. K. , Geiger F. M. , Martin S. T.
Published: March 2015

Abstract. The change in shape of atmospherically relevant organic particles is used to estimate the viscosity of the particle material without the need for removal from aerosol suspension. The dynamic shape factors χ of particles produced by α-pinene ozonolysis in a flow tube reactor, under conditions of particle coagulation, were measured while altering the relative humidity (RH) downstream of the flow tube. As relative humidity was increased, the results showed that χ could change from 1.27 to 1.02, corresponding to a transition from aspherical to nearly spherical shapes. The shape change could occur at elevated RH because the organic material had decreased viscosity and was therefore able to flow to form spherical shapes, as favored by minimization of surface area. Numerical modeling was used to estimate the particle viscosity associated with this flow. Based on particle diameter and RH exposure time, the viscosity dropped from 10(8.7±2.0) to 10(7.0±2.0) Pa s (2σ) for an increase in RH from < 5 to 58% at 293 K, corresponding to a solid to semisolid transition for the organic material. These results imply that the equilibration of the chemical composition of the particle phase with the gas phase can shift from hours at mid-range RH to weeks for low RH.
Improving satellite-retrieved aerosol microphysical properties using GOCART data
Authors: Li S. , Kahn R. , Chin M. , Garay M. J. , Liu Y.
Published: March 2015

Abstract. The Multi-angle Imaging SpectroRadiometer (MISR) aboard the NASA Earth Observing System's Terra satellite can provide more reliable aerosol optical depth (AOD) and better constraints on particle size (Ångström exponent, or ANG), sphericity, and single-scattering albedo (SSA) than many other satellite instruments. However, many aerosol mixtures pass the algorithm acceptance criteria, yielding a poor constraint, when the particle-type information in the MISR radiances is low, typically at low AOD. We investigate adding value to the MISR aerosol product under these conditions by filtering the list of MISR-retrieved mixtures based on agreement between the mixture ANG and absorbing AOD (AAOD) values, and simulated aerosol properties from the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model. MISR–GOCART ANG difference and AAOD ratio thresholds for applying GOCART constraints were determined based on coincident AOD, ANG, and AAOD measurements from the AErosol RObotic NETwork (AERONET). The results were validated by comparing the adjusted MISR aerosol optical properties over the contiguous USA between 2006 and 2009 with additional AERONET data. The correlation coefficient (r) between the adjusted MISR ANG derived from this study and AERONET improves to 0.45, compared to 0.29 for the MISR Version 22 standard product. The ratio of the adjusted MISR AAOD to AERONET increases to 0.74, compared to 0.5 for the MISR operational retrieval. These improvements occur primarily when AOD < 0.2 for ANG and AOD < 0.5 for AAOD. Spatial and temporal differences among the aerosol optical properties of MISR V22, GOCART, and the adjusted MISR are traced to (1) GOCART underestimation of AOD and ANG in polluted regions; (2) aerosol mixtures lacking in the MISR Version 22 algorithm climatology; (3) low MISR sensitivity to particle type under some conditions; and (4) parameters and thresholds used in our method.
MISR calibration issues in high-contrast scenes, and empirical corrections
Authors: Limbacher J. A. , Kahn R. A.
Published: March 2015

Abstract. We diagnose the potential causes for the Multi-angle Imaging SpectroRadiometer's (MISR) persistent high aerosol optical depth (AOD) bias at low AOD with the aid of coincident MODerate-resolution Imaging Spectroradiometer (MODIS) imagery from NASA's Terra satellite. Internal reflections within the MISR instrument are responsible for a large portion of the high AOD bias in high-contrast scenes, which are especially common as broken-cloud situations over ocean. Discrepancies between MODIS and MISR nadir-viewing near-infrared (NIR) images are used to optimize nine parameters, along with a background reflectance modulation term (that was modeled separately), to represent the observed features. Independent, surface-based AOD measurements from the AErosol RObotic NETwork (AERONET) and the Marine Aerosol Network (MAN) are compared with MISR Research Algorithm (RA) AOD retrievals for 1118 coincidences to validate the corrections when applied to the nadir and off-nadir cameras. Additionally, the calibration coefficients for the red and NIR channels used for MISR over-water aerosol retrievals were reassessed with the RA to be consistent on a camera-by-camera basis. With these corrections, plus the baseline RA corrections applied (except enhanced cloud screening), the median AOD bias in the mid-visible (green) band decreases from 0.010 to 0.002, the RMSE decreases by ~ 10%, and the slope and correlation of the MISR vs. sun photometer Ångström Exponent improves. For AOD558 nm < 0.10 and with additional cloud screening, the median bias for the RA-retrieved AOD in the green band decreases from 0.011 to 0.003, compared to ~ 0.023 for the Standard Algorithm (SA). RMSE decreases by ~ 20% compared to the baseline (uncorrected) RA and by 17–53% compared to the SA. After all corrections and cloud screening are implemented, for AOD558 nm < 0.10, which includes about half the validation data, 68% absolute AOD errors for the RA have dropped to < 0.02 (~ 0.018).
Shortwave surface radiation budget network for observing small-scale cloud inhomogeneity fields
Authors: Madhavan B. L. , Kalisch J. , Macke A.
Published: March 2015

Abstract. As part of the High Definition Clouds and Precipitation for advancing Climate Prediction Observational Prototype Experiment (HOPE), a high spatial density network of 99 silicon photodiode pyranometers was set up around Jülich (10 km x 12 km area) from April to July 2013, to capture the variability in the radiation field at the surface induced by small-scale cloud inhomogeneity. Each of these autonomously operated pyranometer stations was equipped with weather sensors for simultaneous measurements of ambient air temperature and relative humidity. In this paper, we provide the details of this unique setup of the pyranometer network and the data analysis with initial quality screening procedure we adopted. We also present some exemplary cases consisting of the days with clear, broken cloudy and overcast skies to assess our spatio-temporal observations from the network, and validate their consistency with other collocated radiation measurements available during the HOPE period.
Vertical level selection for temperature and trace gas profile retrievals using IASI
Authors: Vincent R. A. , Dudhia A. , Ventress L. J.
Published: March 2015

Abstract. This work presents a new iterative method for optimally selecting a vertical retrieval grid based on the location of the information content while accounting for inter-level correlations. Sample atmospheres initially created to parametrise the RTTOV forward model are used to compare the presented iterative vertical selection method with two other common approaches, which are using levels of equal vertical spacing and selecting levels based on the cumulative trace of the averaging kernel matrix (AKM). This new method is shown to outperform compared methods for synthesized profile retrievals with IASI of temperature, H2O, O3, CH4, and CO. However, the benefits of using the more complicated iterative approach compared to the simpler method of referencing the cumulative trace of the AKM are slight and may not justify the added effort. Furthermore, comparing retrievals using a globally optimized static grid vs. an atmosphere specific one shows that a static grid is likely appropriate for retrievals of O3, CH4, and CO. However, developers of temperature and H2O retrieval schemes may at least consider using adaptive or location specific vertical retrieval grids.
Geographic and seasonal variation of dissolved methane and aerobic methane oxidation in Alaskan lakes
Authors: Martinez-Cruz K. , Sepulveda-Jauregui A. , Walter Anthony K. , Thalasso F.
Published: March 2015

Abstract. Methanotrophic bacteria play an important role oxidizing a significant fraction of methane (CH4) produced in lakes. Aerobic CH4 oxidation depends on lake CH4 and oxygen (O2) concentrations, temperature, and organic carbon input to lakes, including from thawing permafrost in thermokarst (thaw)-affected lakes. Given the large variability in these environmental factors, CH4 oxidation is expected to be subject to large seasonal and geographic variations, which have been scarcely reported in the literature. In the present study, we measured CH4 oxidation rates in 30 Alaskan lakes along a north–south latitudinal transect during winter and summer with a new field laser spectroscopy method. Additionally, we measured dissolved CH4 and O2 concentrations. We found that in the winter, aerobic CH4 oxidation was mainly controlled by the dissolved O2 concentration, while in the summer it was controlled primarily by the CH4 concentration, which was in deficit compared to dissolved O2. The permafrost environment of the lakes was identified as another key factor. Thermokarst (thaw) lakes formed in yedoma-type permafrost had significantly higher CH4 oxidation rates compared to other thermokarst and non-thermokarst lakes formed in non-yedoma permafrost environments. These results confirm that landscape processes play an important role in lake CH4 cycling.
The Global Terrestrial Network for Permafrost Database: metadata statistics and prospective analysis on future permafrost temperature and active layer depth monitoring site distribution
Authors: Biskaborn B. K. , Lanckman J.-P. , Lantuit H. , Elger K. , Streletskiy D. A. , Cable W. L. , Romanovsky V. E.
Published: March 2015

Abstract. The Global Terrestrial Network for Permafrost (GTN-P) provides the first dynamic database associated with the Thermal State of Permafrost (TSP) and the Circumpolar Active Layer Monitoring (CALM) programs, which extensively collect permafrost temperature and active layer thickness data from Arctic, Antarctic and Mountain permafrost regions. The purpose of the database is to establish an "early warning system" for the consequences of climate change in permafrost regions and to provide standardized thermal permafrost data to global models. In this paper we perform statistical analysis of the GTN-P metadata aiming to identify the spatial gaps in the GTN-P site distribution in relation to climate-effective environmental parameters. We describe the concept and structure of the Data Management System in regard to user operability, data transfer and data policy. We outline data sources and data processing including quality control strategies. Assessment of the metadata and data quality reveals 63% metadata completeness at active layer sites and 50% metadata completeness for boreholes. Voronoi Tessellation Analysis on the spatial sample distribution of boreholes and active layer measurement sites quantifies the distribution inhomogeneity and provides potential locations of additional permafrost research sites to improve the representativeness of thermal monitoring across areas underlain by permafrost. The depth distribution of the boreholes reveals that 73% are shallower than 25 m and 27% are deeper, reaching a maximum of 1 km depth. Comparison of the GTN-P site distribution with permafrost zones, soil organic carbon contents and vegetation types exhibits different local to regional monitoring situations on maps. Preferential slope orientation at the sites most likely causes a bias in the temperature monitoring and should be taken into account when using the data for global models. The distribution of GTN-P sites within zones of projected temperature change show a high representation of areas with smaller expected temperature rise but a lower number of sites within arctic areas were climate models project extreme temperature increase. This paper offers a scientific basis for planning future permafrost research sites on large scales.
Improved routines to model the ocean carbonate system: mocsy 2.0
Authors: Orr J. C. , Epitalon J.-M.
Published: March 2015

Abstract. Modelers compute ocean carbonate chemistry often based on code from the Ocean Carbon Cycle Model Intercomparison Project (OCMIP), last revised in 2005. Here we offer improved publicly available Fortran 95 routines to model the ocean carbonate system (mocsy 2.0). Both codes take as input dissolved inorganic carbon CT and total alkalinity AT, tracers that are conservative with respect to mixing and changes in temperature and salinity. Both use the same thermodynamic equilibria to compute surface-ocean pCO2 and simulate air–sea CO2 fluxes, but mocsy 2.0 uses a faster and safer algorithm (SolveSAPHE) to solve the alkalinity-pH equation, applicable even under extreme conditions. The OCMIP code computes only surface pCO2, while mocsy computes all other carbonate system variables throughout the water column. It also avoids three common model approximations: that density is constant, that modeled potential temperature is equal to in situ temperature, and that depth is equal to pressure. Errors from these approximations grow with depth, e.g., reaching 3% or more for pCO2, H+, and ΩA at 5000 m. The mocsy package uses the equilibrium constants recommended for best practices. It also offers two new options: (1) a recently reassessed total boron concentration BT that is 4% larger and (2) new K1 and K2 formulations designed to include low-salinity waters. Although these options enhance surface pCO2 by up to 7 μatm, individually, they should be avoided until (1) best-practice equations for K1 and K2 are reevaluated with the new BT and (2) formulations of K1 and K2 for low salinities are adjusted to be consistent among pH scales. The common modeling practice of neglecting alkalinity contributions from inorganic P and Si leads to substantial biases that could easily be avoided. With standard options for best practices, mocsy agrees with results from the CO2SYS package within 0.005% for the three inorganic carbon species (concentrations differ by less than 0.01 μmol kg−1). Yet by default, mocsy's deep-water fCO2 and pCO2 are many times larger than those from older packages, because they include pressure corrections for K0 and the fugacity coefficient.
Development and basic evaluation of a prognostic aerosol scheme (v1) in the CNRM Climate Model CNRM-CM6
Authors: Michou M. , Nabat P. , Saint-Martin D.
Published: March 2015

Abstract. We have implemented a prognostic aerosol scheme (v1) in CNRM-CM6, the climate model of CNRM-GAME and CERFACS, based upon the GEMS/MACC aerosol module of the ECMWF operational forecast model. This scheme describes the physical evolution of the five main types of aerosols, namely black carbon, organic matter, sulfate, desert dust and sea salt. In this work, we describe the characteristics of our implementation, for instance, taking into consideration a different dust scheme or boosting biomass burning emissions by a factor of 2, as well as the evaluation performed on simulation output. The simulations consist of time slice simulations for 2004 conditions and transient runs over the 1993–2012 period, and are either free-running or nudged towards the ERA-Interim Reanalysis. Evaluation data sets include several satellite instrument AOD (aerosol optical depth) products (i.e., MODIS Aqua classic and Deep-Blue products, MISR and CALIOP products), as well as ground-based AERONET data and the derived AERONET climatology, MAC-v1. The uncertainty of aerosol-type seasonal AOD due to model internal variability is low over large parts of the globe, and the characteristics of a nudged simulation reflect those of a free-running simulation. In contrast, the impact of the new dust scheme is large, with modelled dust AODs from simulations with the new dust scheme close to observations. Overall patterns and seasonal cycles of the total AOD are well depicted with, however, a systematic low bias over oceans. The comparison to the fractional MAC-v1 AOD climatology shows disagreements mostly over continents, while that to AERONET sites outlines the capability of the model to reproduce monthly climatologies under very diverse dominant aerosol types. Here again, underestimation of the total AOD appears in several cases, sometimes linked to insufficient efficiency of the aerosol transport away from the aerosol sources. Analysis of monthly time series at 166 AERONET sites shows, in general, correlation coefficients higher than 0.5 and lower model variance than observed. A large interannual variability can also be seen in the CALIOP vertical profiles over certain regions of the world. Overall, this prognostic aerosol scheme appears promising for aerosol-climate studies. There is room, however, for implementing more complex parameterisations in relation to aerosols.
Matching soil grid unit resolutions with polygon unit scales for DNDC modelling of regional SOC pool
Authors: Zhang H. D. , Yu D. S. , Ni Y. L. , Zhang L. M. , Shi X. Z.
Published: March 2015

Abstract. Matching soil grid unit resolution with polygon unit map scale is important to minimize uncertainty of regional soil organic carbon (SOC) pool simulation as their strong influences on the uncertainty. A series of soil grid units at varying cell sizes were derived from soil polygon units at the six map scales of 1:50 000 (C5), 1:200 000 (D2), 1:500 000 (P5), 1:1 000 000 (N1), 1:4 000 000 (N4) and 1:14 000 000 (N14), respectively, in the Tai lake region of China. Both format soil units were used for regional SOC pool simulation with DeNitrification–DeComposition (DNDC) process-based model, which runs span the time period 1982 to 2000 at the six map scales, respectively. Four indices, soil type number (STN) and area (AREA), average SOC density (ASOCD) and total SOC stocks (SOCS) of surface paddy soils simulated with the DNDC, were attributed from all these soil polygon and grid units, respectively. Subjecting to the four index values (IV) from the parent polygon units, the variation of an index value (VIV, %) from the grid units was used to assess its dataset accuracy and redundancy, which reflects uncertainty in the simulation of SOC. Optimal soil grid unit resolutions were generated and suggested for the DNDC simulation of regional SOC pool, matching with soil polygon units map scales, respectively. With the optimal raster resolution the soil grid units dataset can hold the same accuracy as its parent polygon units dataset without any redundancy, when VIV < 1% of all the four indices was assumed as criteria to the assessment. An quadratic curve regression model y = −8.0 × 10−6x2 + 0.228x + 0.211 (R2 = 0.9994, p < 0.05) was revealed, which describes the relationship between optimal soil grid unit resolution (y, km) and soil polygon unit map scale (1:x). The knowledge may serve for grid partitioning of regions focused on the investigation and simulation of SOC pool dynamics at certain map scale.
Documentary evidence of historical floods and extreme rainfall events in Sweden 1400–1800
Authors: Retsö D.
Published: March 2015

Abstract. This article explores documentary evidence of floods and extreme rainfall events in Sweden in the pre-instrumental period (1400–1800). The survey shows that two sub-periods can be considered as flood-rich, 1590–1670 and the early 18th century. The result related to a low degree of human impact on hydrology during the period, suggests that climatic factors, such as lower temperatures and increased precipitation connected to the so-called Little Ice Age rather than large-scale atmospheric circulation patterns, should be considered as the main driver behind flood frequency and magnitude.
Accelerated gravity testing of aquitard core permeability and implications at formation and regional scale
Authors: Timms W. A. , Crane R. , Anderson D. J. , Bouzalakos S. , Whelan M. , McGeeney D. , Rahman P. F. , Guinea A. , Acworth R. I.
Published: March 2015

Abstract. Evaluating the possibility of leakage through low permeability geological strata is critically important for sustainable water supplies, the extraction of fuels from strata such as coal beds, and the confinement of waste within the earth. The current work demonstrates that relatively rapid and reliable hydraulic conductivity (K) measurement of aquitard cores using accelerated gravity can inform and constrain larger scale assessments of hydraulic connectivity. Steady state fluid velocity through a low K porous sample is linearly related to accelerated gravity (g-level) in a centrifuge permeameter (CP) unless consolidation or geochemical reactions occur. The CP module was custom designed to fit a standard 2 m diameter geotechnical centrifuge (550 g maximum) with a capacity for sample dimensions of 30 to 100 mm diameter and 30 to 200 mm in length, and a maximum total stress of ~2 MPa at the base of the core. Formation fluids were used as influent to limit any shrink–swell phenomena which may alter the permeability. Vertical hydraulic conductivity (Kv) results from CP testing of cores from three sites within the same regional clayey silt formation varied (10−7 to 10−9 m s−1, n = 14). Results at one of these sites (1.1 × 10−10 to 3.5 × 10−9 m s−1, n = 5) that were obtained in < 24 h were similar to in situ Kv values (3 × 10−9 m s−1) from pore pressure responses over several weeks within a 30 m clayey sequence. Core scale and in situ Kv results were compared with vertical connectivity within a regional flow model, and considered in the context of heterogeneity and preferential flow paths at site and formation scale. More reliable assessments of leakage and solute transport though aquitards over multi-decadal timescales can be achieved by accelerated core testing together with advanced geostatistical and numerical methods.
Decadal variability and trends of the Benguela Upwelling System as simulated in a high-resolution ocean simulation
Authors: Tim N. , Zorita E. , Hünicke B.
Published: March 2015

Abstract. Detecting the atmospheric drivers of the Benguela Upwelling Systems is essential to understand its present variability and its past and future changes. We present a statistical analysis of an ocean-only simulation driven by observed atmospheric fields over the last decades with the aim of identifying the large-scale atmospheric drivers of upwelling variability and trends. The simulation is found to reproduce well the seasonal cycle of upwelling intensity, with a maximum in the June-to-August season in North Benguela and in the December-to-February season in South Benguela. The statistical analysis of the interannual variability of upwelling focuses on its relationship to atmospheric variables (sea level pressure, 10 m-wind, wind stress). The relationship between upwelling and the atmospheric variables differ somewhat in the two regions, but generally, the correlation patterns reflect the common atmospheric pattern favoring upwelling: southerly wind/wind stress, strong subtropical anticyclone, and an ocean-land sea level pressure gradient. In addition, the statistical link between upwelling and large-scale climate variability modes was analyzed. The El Niño Southern Oscillation and the Antarctic Oscillation exert some influence on austral summer upwelling velocities in South Benguela. The decadal evolution and the long-term trends of upwelling and of ocean-minus-land air pressure gradient do not agree with Bakun's hypothesis that anthropogenic climate change should generally intensify coastal upwelling.