bluuebunny/crossref_metadata_2025 huggingface dataset:
Adapter Sleeves Are Not Needed to Reduce the Risk of Fracture of a New Ceramic Head Implanted on a Well-Fixed Stem
Authors: Kim Young-Hoo , Park Jang-Won , Kim Jun-Shik
Published: May 2018

The purpose of this study was to assess (1) the prevalence of the fracture of ceramic heads implanted on used trunnions of well-fixed stems without using a titanium adapter sleeve; (2) the prevalence of trunnionosis secondary to fretting and/or corrosion at the trunnion of the well-fixed stem; and (3) clinical and radiographic results and the survival rate of the revised acetabular components. Eighty-eight patients (100 hips) underwent isolated revision of the acetabular components for polyethylene wear and osteolysis of the acetabulum. The study group consisted of 70 men and 18 women with a mean age of 52.8 years (range, 31–54 years) when the primary total hip arthroplasty was performed. Evidence of fretting and corrosion of the trunnion of all prostheses was examined macroscopically using a magnifying lens. Degree of fretting and corrosion of the trunnion was assessed using a 4-point scoring technique. A new 36-mm alumina delta ceramic head was implanted on the trunnion of a well-fixed stem without using a titanium adapter sleeve in all hips. The mean follow-up after revision of the acetabular component was 12.8 years (range, 10–14 years). Among the 100 new ceramic heads implanted on a well-fixed stem, no fracture of the ceramic head occurred at a mean follow-up of 12.8 years. The median fretting and corrosion scores for the trunnions were 1.5±1.1 and 1.3±0.9 points, respectively. The mean Harris hip score at the final follow-up was 89±15 points (range, 63–100 points). Survivorship of the revised acetabular components at 14 years was 95% (95% confidence interval, 87.6%–98.6%). [
Orthopedics
. 2018; 41(3):158–163.]
Bilateral Keratoconus Induced by Secondary Hypothyroidism After Radioactive Iodine Therapy
Authors: Lee Ramon , Hafezi Farhad , Randleman J. Bradley
Published: May 2018

PURPOSE:

To present a case of new-onset, bilateral, rapidly progressive keratoconus induced by secondary hypothyroidism after radioactive iodine therapy during the sixth decade of life that was successfully treated with corneal cross-linking.

METHODS:

Case report and literature review.

RESULTS:

A 53-year-old woman with no ocular complaints but with a history of Graves' disease and thyrotoxicosis was treated with radioactive iodine therapy and oral levothyroxine for secondary acquired hypothyroidism 3 years prior. Initially, uncorrected distance visual acuity (UDVA) was 20/40 and corrected distance visual acuity (CDVA) was 20/25 in both eyes. Over the following 3 years, the patient developed worsening UDVA and CDVA, with increasing manifest astigmatism of greater than 7.00 diopters (D) in the right eye and 4.75 D in the left eye, with corneal thinning and focal steepening and was diagnosed as having bilateral progressive keratoconus. The patient underwent sequential corneal cross-linking with resultant postoperative CDVA of 20/20 and reduced maximum keratometry and manifest astigmatism in both eyes. The patient's thyroid levels were within normal limits throughout the clinical course.

CONCLUSIONS:

This case provides evidence of the relationship between keratoconus development and thyroid gland dysfunction. The pathophysiology of this relationship has yet to be completely elucidated, but elevated levels of thyroxine in the aqueous humor and tear film and thyroxine receptors in the cornea likely play a role. Screening topographies for patients with thyroid gland dysfunction may be of value for these higher risk patients.

[
J Refract Surg.
2018;34(5):351–353.]
Risk Factors for Re-treatment Following Hyperopic LASIK
Authors: Mimouni Michael , Flores Victor , Sela Tzahi , Munzer Gur , Kaiserman Igor
Published: May 2018

PURPOSE:

To determine the risk factors for re-treatment following LASIK in hyperopic eyes.

METHODS:

In this retrospective study, consecutive hyperopic eyes underwent LASIK at the Care Vision Laser Centers, Tel-Aviv, Israel, between January 2000 and October 2014. Patients were divided into two groups according to whether or not they underwent additional refractive surgery (re-treatment). Logistic regression was performed to determine predictors of re-treatment.

RESULTS:

Overall, 1,776 eyes of 888 patients were included, of which 82 (4.6%) needed re-treatment. Eyes that underwent re-treatment were of older age (49.1 ± 7.5 vs 46.9 ± 10.3 years,
P
= .01), had better preoperative CDVA (1.0 ± 0.14 vs 0.95 ± 0.15 decimal,
P
= .001), were treated more often with the Allegretto EX200 (Alcon Laboratories, Inc., Fort Worth, TX) as opposed to the EX-500 (90.2% vs 63.7%,
P
< .001), and were treated with a Moria M2-90 microkeratome (Moria S.A., Antony, France) as opposed to Moria SBK-90 (66.7% vs 36.4%,
P
< .001). Multiple logistic regresison analysis demonstrated that treatment with Allegretto EX200 (odds ratio: 2.67,
P
= .04), and Moria M2-90 microkeratome (odds ratio: 2.23,
P
= .04) and older age (odds ratio: 1.03,
P
= .03) were significant risk factors for re-treatment.

CONCLUSIONS:

Factors associated with a higher risk of re-treatment following hyperopic LASIK include type of laser, type of microkeratome used, and older age. Identifying such factors may aid in reducing future retreatment rates in hyperopic LASIK.

[
J Refract Surg.
2018;34(5):316–320.]
Corneal Inlays for Presbyopia Explanted Due to Corneal Haze
Authors: Ong Hon Shing , Chan Anita S. , Yau Christine W. , Mehta Jodhbir S.
Published: May 2018

PURPOSE:

To present 3 patients who required explantation of KAMRA inlays (AcuFocus, Inc., Irvine, CA) due to visual symptoms caused by postoperative corneal haze.

METHODS:

Case series.

RESULTS:

All patients had good near and distance vision immediately following implantation. They developed visual symptoms 3 to 6 years later. All patients reported a decline in distance vision. Two patients had hyperopic shift with flattening of the central cornea. Six months following explantation, all patients reported improvement in visual symptoms. A reversal of hyperopic shift was also observed, with improvement in corneal profiles on topography. Histopathology of the explanted inlays showed thin, acellular collagenous fibrotic membranes over the inlays with occasional chronic inflammatory cells.

CONCLUSIONS:

It is important for health care professionals to be made aware of this reversible complication following KAMRA inlay implantation. Long-term monitoring is recommended.

[
J Refract Surg.
2018;34(5):357–360.]
Sights, sounds and images: catching the metropolis in/at work(s)
Authors: Guillard Séverin , Pleven Bertrand
Published: May 2018

In French and English-speaking geographies, movies and music works are widely recognized as elements which contribute to shaping the imaginaries of cities and urban spaces. However, these two art forms have long been regarded separately within the discipline. With the idea of contributing to the development of a more global urban geography of art, we would like to show the interest of combining a musical and cinematic perspective to understand fictional images of the cities conveyed in specific art works. We’ll illustrate our point through the study of two fictional movies released in the middle of the 2000’s: Larry Clark’s Wassup Rockers and Chris Robinson’s ATL. Each of them being set in an American city, respectively in Los Angeles and Atlanta, they share the will of using music as a tool to describe the urban context. Through this study, we’ll show how the filmic and musical aspects of these movies complete each other to frame an imaginary on the American metropolises. We’ll make the connection with the goal of each movie, highlighting how the images conveyed in these works are dialoguing with an already existing body of representations about these cities, leading to its reproduction or its subversion.
MHD Nanofluid Flow Past a Rotating Disk with Thermal Radiation in the Presence of Aluminum and Titanium Alloy Nanoparticles
Authors: Makinde Oluwole Daniel , Mahanthesh Basavarajappa , Gireesha Bijjanal Jayanna , Shashikumar N.S. , Monaledi R.L. , Tshehla M.S.
Published: May 2018

The effects of thermal and exponential space dependent heat sources (THS and ESHS) on magneto-nanoliquid flow across a rotating disk with uniform stretching rate along radial direction are scrutinized in this communication. H2O based nanoliquids containing aluminium (AA 7075) and titanium (Ti6Al4V) alloy nanoparticles are considered. The AA7075 is made up of 90% Al, 5-6% Zn, 2-3% Mg, 1-2% Cu with additives such as Fe, Mn and Si etc. The flow is driven due to rotating disk with uniform stretching of the disk. Impacts of Joule and viscous heating are also deployed. The multidegree ordinary differential equations are formed via Von Karman transformations. The obtained non-linear BVP is solved by Runge-Kutta-Fehlberg based shooting approach (RKFS). Graphical illustrations depict the impacts of influential parameters on flow fields. The skin friction and Nusselt number are also calculated. Results pointed out that the thermal boundary layer growth stabilizes due to the influence of ESHS aspect. Velocities of nanofluid are superior than that of nanoliquid. Furthermore, the thermal performance of base liquid is outstanding when we added titanium alloy nanoparticles in comparison with aluminium alloy nanoparticles.
Do Supply Chain Management Practices Contribute Firm Competitiveness? A Study based on Medium Scale Entrepreneurial Firms in Sri Lanka
Authors: Wijetunge W.A.D.S , Ranwala R.
Published: May 2018

It is evident that supply chain management (SCM) practices are widely practiced by large scale and established business organizations as benchmark. Not only the large firms but also the small and medium scale businesses are required to follow these practices to achieve the growth. Further, present business environment is very competitive and organizations should face this as a challenge. This study is undertaken to empirically investigate the impact of supply chain management on competitiveness. Sample consists of 327 production managers of medium scale entrepreneurial firms (manufacturing sector) in Colombo district. The analyzed data supports the hypotheses revealing that higher the level of involvement in SCM practices higher the competitiveness. Further, it is found that except level of information quality and lean practices, other practices of SCM (Strategic partnership with suppliers, customer relationship, level of information sharing and internal supply chain process are significant factors that affect firm competitiveness.
Vegetation type conservation targets, status and level of protection in KwaZulu-Natal in 2016
Authors: Jewitt, Debbie
Published: May 2018

Background: Systematic conservation planning aims to ensure representivity and persistence of biodiversity. Quantitative targets set to meet these aims provide a yardstick with which to measure the current conservation status of biodiversity features and measure the success of conservation actions.Objectives: The conservation targets and current ecosystem status of vegetation types and biomes occurring in KwaZulu-Natal (KZN) were assessed, and their level of formal protection was determined, to inform conservation planning initiatives in the province.Method: Land cover maps of the province were used to determine the amount of natural habitat remaining in KZN. This was intersected with the vegetation map and assessed relative to their conservation targets to determine the ecosystem status of each vegetation type in KZN. The proclaimed protected areas were used to determine the level of protection of each vegetation type.Results: In 17 years (1994–2011), 19.7% of natural habitat was lost to anthropogenic conversion of the landscape. The Indian Ocean Coastal Belt and Grassland biomes had the least remaining natural habitat, the highest rates of habitat loss and the least degree of formal protection.Conclusion: These findings inform conservation priorities in the province. Vegetation type targets need to be revised to ensure long-term persistence. Business-as-usual is no longer an option if we are to meet the legislative requirements and mandates to conserve the environment for current and future generations.
Perceptions of small business executives on determinants of performance in the construction industry in Gauteng, South Africa
Authors: Hove George , Banjo Adewale
Published: May 2018

Orientation: The South African (SA) government expects emerging contractors (ECs) to become the main players in economic transformation and growth, job creation and income generation. However, ECs fail to live up to the expectations as some are characterised by low performance levels and are at risk of business closure.Research purpose: The purpose of this research was to examine the perceptions of small business executives (SBEs) on determinants of ECs’ performance so that a performance model that could guide ECs in the construction industry is developed.Motivation for the study: Despite the significance of ECs to the SA economy, researchers have constantly omitted to identify and examine the role played by the perceptions of SBEs on the determinants of performance and this gap in the body of knowledge would be closed by this study.Research design, approach and method: A mixed approach was used to examine the perceptions of SBEs on determinants of performance by applying both qualitative and quantitative research approaches. Data were obtained from 433 urban based ECs registered with the Construction Industry Development Board (CIDB) in the construction industry in Gauteng Province. A structured questionnaire and an interview guide were administered as the data collection instruments. Content analysis, regression analysis and multiple linear regressions were performed.Main findings: The analysis of qualitative data demonstrated the perceptions of SBEs that financial factors, manpower, materials, machinery and equipment, project implementation, quality of work, legal and environmental factors and strategic planning were the determinants of ECs’ performance. Multiple linear regressions carried out based on the perceptions of SBEs identified strategic planning, project implementation and project performance as the most statistically significant factors in predicting the performance of ECs in Gauteng Province.Contribution and value add: Based on perceptual analysis of the ECs and multivariate results, a performance prediction model was developed. Furthermore, a new set of significant determinants of performance as perceived by SBEs in South Africa’s (Gauteng Province) construction industry was established.
Current collective engagement stakeholder strategies for South African labour relations
Authors: Madlala Popi C. , Govender Cookie M.
Published: May 2018

Orientation: Collective engagement stakeholder strategies are significant for the creation of harmony in the workplace. It is a known fact that the South African (SA) labour environment has been dominated by industrial action before and after the 1994 democratic transition. To be precise, the statistics reveals that industrial action has increased and become more destructive post-1994.Purpose: The purpose of this article was to present the current collective engagement stakeholder strategies for South African labour relations.Motivation for the study: The SA mining sector has seen more violent strikes, with a higher number of deaths, injuries, criminal activities, arrests, dismissals and job losses in recent years. This article captures the current mining stakeholder strategies shaping the existing labour relations environment.Research approach, design and method: This is a theoretical article highlighting the recent literature on collective engagement in the mining sector in South Africa.Main findings: This article presents the current labour relations incidents, reflecting the need for more effective collective engagement and stakeholder management strategies.Practical and managerial implications: The current labour relations context has prompted key stakeholders at the National Economic Development and Labour Council (NEDLAC) to look specifically at promoting employment, labour market stability, the right to strike, minimising violence through collective bargaining and highlighting the role of the state, reducing vulnerability through social protection and increasing the minimum wage.Contribution or value add: This article adds theoretically to the existing body of knowledge regarding collective engagement and stakeholder strategies in the SA mining sector.
Ubuntu as care: Deconstructing the gendered Ubuntu
Authors: Chisale Sinenhlanhla S.
Published: May 2018

In this article, I explore the concept of Ubuntu in a context of caregiving with the aim of deconstructing the gendering of caregiving in a context of pastoral care. Using a qualitative approach, this article draws from the empirical findings of primeval praxis of Ubuntu from a study conducted on the KwaZulu-Natal chapter of South Africa’s National Research Foundation (NRF) funded ‘Archaeology of Ubuntu’ project. Empirical findings were evaluated through African women theology. Findings of this article highlight that Ubuntu in a context of caregiving is not exclusively feminine because men also display strong tendencies of care in African traditional communities. This suggests that pastoral care in an African context should not be gendered because findings of the article confirm that the Zulu elders from KwaZulu-Natal generally linked Ubuntu to communal care where men and women partnered in extending caregiving to those in need.Intradisciplinary and/or interdisciplinary implications: Although the article is written from a socio-anthropological perspective, it integrates African traditional presumptions of gender and care ethics that are significant in extending pastoral care by reviewing literature from sociology, anthropology, gender, feminist studies, practical theology and systematic theology.
A Reformed assessment of George Lindbeck’s ecclesial ethics
Authors: Kim Junseop
Published: May 2018

Lindbeck’s theology can be defined as an ecclesiology. For the ultimate concern in his life and thoughts is an ecclesiastical one. His ecclesial ethics is based on his ecclesiology. It has two aspects: the intra-systematic view of truth and the cultural-linguistic view of religion. From a Reformed viewpoint, it attempts to overcome theological liberals’ universalistic and reductionist tendency by emphasising the particularity of religions. It also focuses on the -intra-textual and performative aspects of Christian ethics. Its notion of incommensurability, however, has difficulty in explaining the continuity between the world of the Bible and the extrabiblical world, and between religions. In contrast, Reformed theology can solve the problem by using the idea of revelatory continuity.Intradisciplinary and/or interdisciplinary implication: As a Reformed intradisciplinary assessment on George Lindbeck’s ecclesial ethics, this article maintains that his notion of incommensurability finds it difficult to explain the continuity between the world of the Bible and the extrabiblical world, and between religions, and that a Reformed idea of revelatory continuity can be its solution.
Risk factors for ruptured intracranial aneurysms
Authors: Wang Guang-Xian , Zhang Dong , Wang Zhi-Ping , Yang Liu-Qing , Yang Hua , Li Wen
Published: May 2018

Background & objectives:

The treatment of unruptured intracranial aneurysms (IAs) remains controversial; the ability to predict the risk of rupture for an aneurysm would be of clinical value. The aim of this study was to determine and evaluate the predictive value of the risk factors of IA rupture.

Methods:

This retrospective study involved 379 consecutive patients with 441 aneurysms between August 2011 and July 2014. Based on clinical data and computed tomography angiography findings, the potential of risk factors to predict the aneurysmal rupture was assessed using statistical methods.

Results:

Age, hypertension, heart disease, diabetes mellitus, cerebral atherosclerosis, aneurysms located at the internal carotid artery (ICA) and neck width (N) correlated negatively with rupture risk. Aneurysms located at the anterior communicating artery, bifurcation, irregularity, with a daughter sac, aneurysm height, maximum size, aspect ratio (AR), height-to-width ratio and bottleneck factor were significantly and positively correlated with rupture risk. The multivariate logistic regression model revealed that bifurcation aneurysm, irregular aneurysm and high AR increased the rupture risk, while cerebral atherosclerosis, aneurysm located on the ICA and greater N decreased the risk. Receiver operating characteristic analysis of AR curve values differed according to circumstances.

Interpretation & conclusions:

Cerebral atherosclerosis, location in the ICA and larger N were the protective factors against aneurysm rupture, and IAs located at bifurcations, irregular shape and increased AR indicated a greater rupture risk.
Cytopenia in adult brucellosis patients
Authors: Kaya Safak , Elaldi Nazif , Deveci Ozcan , Eskazan Ahmet Emre , Bekcibasi Muhammed , Hosoglu Salih
Published: May 2018

Background & objectives:

Brucellosis can lead to haematological abnormalities including cytopenia confusing with haematological malignancies. The aim of this study was to compare the main characteristics of brucellosis patients without cytopenia (Group 1) and with cytopenia (Group 2).

Methods:

This five-year period study which was performed in two referral hospitals in Turkey, included all adult brucellosis patients. Abnormally, low counts of leucocyte or haemoglobin or platelets in a patient were considered as cytopenia. The demographics, clinical, laboratory, treatment and outcome data were analyzed.

Results:

A total of 484 brucellosis patients were enrolled. Among the cases, 162 (33.5%) of them had cytopenia. One hundred and four (21.5%) had anaemia, 88 (18.8%) had thrombocytopenia, 71 (14.6%) had leucopenia and 28 (5.8%) had pancytopenia. The mean age of group 2 was 35.01±16.05 yr and it was 33.31±14.39 yr in group 1. While there was no difference between the groups in terms of duration of treatment, the median length of hospital stay (LOS) was significantly longer in group 2 (9 vs 10 days; P <0.001). The most frequently applied combination therapy consisted of doxycycline plus rifampicin and doxycycline plus streptomycin regimens. No significant difference was observed in terms of duration of treatment, LOS and restoration time of cytopenia between the patients who received either of these combinations.

Interpretation & conclusions:

Our findings suggested that the patients with cytopenia should be investigated for brucellosis, especially if living in, or with a history of travel to, endemic areas, in view of the increase in world travel.
Effects of synbiotics on ileal microbiota
Authors: Komatsu Shunichiro , Sakamoto Eiji , Asahara Takashi , Nomoto Koji , Nagino Masato
Published: May 2018

Background & objectives:

Despite advancements in molecular-based methods, the composition of the human ileal microbiota and the effects of synbiotics/probiotics on its microbes remain poorly understood. The aim of this study was to determine the composition of the mucus microbiota in the human ileum and to assess the effects of oral administration of synbiotics on the microbiota.

Methods:

As part of a clinical trial for synbiotics treatment and surgical infection, ileal mucus was sampled when resection of the ileocecal portion was required. The microbiota composition was examined using 16S rRNA-targeted real-time-quantitative polymerase chain reaction.

Results:

A total of 33 samples from the synbiotics group and 39 from the control group were analyzed. Total numbers of bacteria in the ileum were 108.5 cells/g in the synbiotics group and 108.4 cells/g in the control group, in which obligate anaerobes were dominant over facultative anaerobes. The level of Enterobacteriaceae was significantly lower in the synbiotics group than in the control group. The administered probiotics species Lactobacillus casei strain Shirota and Bifidobacterium breve strain Yakult were detected in 42 and 76 per cent of the synbiotics group, respectively. No significant correlations were observed between tumour stage/size and the various microbes present, except for a negative correlation between tumour size and Bifidobacterium.

Interpretation & conclusions:

The present analysis of a substantial number of samples from surgically resected intestines showed an abundance of obligate anaerobes as a characteristic feature of the ileal mucus microbiota. Our results also indicated that the synbiotics intervention induced a prominent reduction in Enterobacteriaceae in the ileal microbiota.
Treatment Outcomes of Brazilian Inmates with Treponema pallidum and Human Immunodeficiency Virus Infection: A Prospective Cohort Study
Authors: Bet Graciela Mendonça dos Santos , Souza Gleyce Hellen de Almeida de , Croda Júlio , Correa Maísa Estopa , Sales Romário Oliveira de , Santos Ruthe Aline da Silva , Viebrantz Enne Sgarbi Renata , Yassuda Renata Terumi Shiguematsu , Coimbra Motta-Castro Ana Rita , Pompílio Maurício Antônio , Simionatto Simone
Published: May 2018

A prospective cohort study was conducted to evaluate the incidence and treatment outcomes of syphilis and human immunodeficiency virus (HIV) in inmates from Central Brazil. In 2013, 3,363 inmates from 12 prisons in the state of Mato Grosso do Sul were recruited, and 1,614 remained incarcerated after 1 year. The inmates were interviewed, and blood samples were collected for serological testing for Treponema pallidum and HIV infections. Inmates infected with T. pallidum or HIV within the first year were assessed for treatment using prison medical record data, based on Venereal Disease Research Laboratory test results, HIV-1 viral load, and CD4 counts. Acquired syphilis was identified in 5.8% (N = 95) of the inmates and 74% (N = 70) of them demonstrated poor treatment outcomes after 1 year. Multivariate analysis revealed that not reporting a stable partner was a risk factor for failure of syphilis treatment. Twenty-five patients had HIV (1.5%) and among those, 13 (52%) had an HIV-1 viral load > 200 copies/mL after 1 year. The incidence of T. pallidum and HIV infections was 0.5% (N = 9). The poor treatment outcomes of syphilis and HIV within Brazilian prisons demonstrate the inadequacy of public health programs. Although the incidence of these infections within the prison population is low, new cases still occur. Our results reinforce the significance of screening programs during prison admission for early detection and treatment of sexually transmitted infections.
Model celovite obravnave funkcionalno degradiranih območij kot podpora trajnostnemu prostorskemu in razvojnemu načrtovanju v Sloveniji
Authors: Lampič Barbara , Kušar Simon , Zavodnik Lamovšek Alma
Published: May 2018

V prispevku predstavljamo značilnosti funkcionalno degradiranih območij (FDO) v Sloveniji, kriterije za njihovo opredelitev, tipologijo ter argumente za nadaljnje spremljanje in redno ažuriranje novega prostorskega in podatkovnega sloja. Natančna prostorska umeščenost in poznavanje značilnosti razvrednotenih območij predstavljata pomemben korak v smeri trajnostnega načrtovanja in umeščanja dejavnosti v prostor. Leta 2017 smo v Sloveniji evidentirali 1081 FDO v skupni površini 3423 ha, med katerimi prevladujejo območja industrijskih in obrtnih dejavnosti.
Microphysical variability of Amazonian deep convective cores observed by CloudSat and simulated by a multi-scale modeling framework
Authors: Dodson J. Brant , Taylor Patrick C. , Branson Mark
Published: May 2018

Abstract. Recently launched cloud observing satellites provide
information about the vertical structure of deep convection and its
microphysical characteristics. In this study, CloudSat reflectivity data is
stratified by cloud type, and the contoured frequency by altitude diagrams
reveal a double-arc structure in deep convective cores (DCCs) above 8 km.
This suggests two distinct hydrometeor modes (snow versus hail/graupel)
controlling variability in reflectivity profiles. The day–night contrast in
the double arcs is about four times larger than the wet–dry season contrast.
Using QuickBeam, the vertical reflectivity structure of DCCs is analyzed in
two versions of the Superparameterized Community Atmospheric Model (SP-CAM)
with single-moment (no graupel) and double-moment (with graupel)
microphysics. Double-moment microphysics shows better agreement with
observed reflectivity profiles; however, neither model variant captures the
double-arc structure. Ultimately, the results show that simulating realistic
DCC vertical structure and its variability requires accurate representation
of ice microphysics, in particular the hail/graupel modes, though this alone
is insufficient.
Effectiveness of Ammonia Reduction on Control of Fine Particle Nitrate
Authors: Guo Hongyu , Otjes Rene , Schlag Patrick , Kiendler-Scharr Astrid , Nenes Athanasios , Weber Rodney J.
Published: May 2018

Abstract. In some regions, reducing aerosol ammonium nitrate (NH4NO3) concentrations may substantially improve air quality. This can be accomplished by reductions in precursor emissions, such as nitrogen oxides (NOx) to lower nitric acid (HNO3) that partitions to the aerosol, or reductions in ammonia (NH3) to lower particle pH and keep HNO3 in the gas phase. Using the ISORROPIA-II thermodynamic aerosol model and detailed observational datasets, we explore the sensitivity of aerosol NH4NO3 to gas phase NH3 and NOx controls for a number of contrasting locations, including Europe, the US, and China. NOx control is always effective, whereas the aerosol response to NH3 control is highly nonlinear and only becomes effective at a thermodynamic “sweet spot”. The analysis provides a conceptual framework and fundamental evaluation on the relative value of NOx versus NH3 control. We find that regardless of the locations examined, it is only when ambient particle pH drops below approximately 3 that NH3 reduction leads to an effective response in PM2.5 mass. The required amount of NH3 reduction to efficiently decrease NH4NO3 at different sites is assessed. Owing to the linkage between NH3 emissions and agricultural productivity, substantial NH3 reduction required in some locations may not be feasible. Finally, controlling NH3 emissions to increase aerosol acidity and evaporate NH4NO3 will have other effects, beyond reduction of PM2.5 NH4NO3, such as increasing aerosol toxicity and changing the deposition patterns of nitrogen and trace nutrients.
Understanding nitrate formation in a world with less sulfate
Authors: Vasilakos Petros , Russell Armistead , Weber Rodney , Nenes Athanasios
Published: May 2018

Abstract. SO2 emission controls, combined with modestly increasing ammonia, have been thought to generate aerosol of significantly reduced acidity where sulfate is partially substituted by nitrate. However, neither expectation agrees with decadal observations in the Southeastern US, suggesting that a fundamentally different response of aerosol pH to emissions changes is occurring. We postulate this ``nitrate substitution paradox'' arises from a positive bias in aerosol pH in model simulations, exacerbated by reductions in SO2 emissions. This bias can elevate pH to where nitrate partitioning is readily promoted, leading to behavior consistent with ``nitrate substitution''. CMAQ simulations are used to investigate this hypothesis; predictions of PM2.5 pH for 2001 emissions compare favorably with observations; for 2011 emissions however, predicted pH increases by 1 unit, presenting a positive trend not seen in the observations. Non-volatile cations (K+, Na+, Ca+2 and Mg+2) in the fine mode are found responsible for most of this trend. pH biases of 1 unit can induce a nitrate bias of 1–2 μg m-3 which may further increase in future projections, reaffirming an otherwise incorrect expectation of “nitrate substitution”. Evaluation of predicted aerosol pH against thermodynamic analysis of observations is therefore a critically important, but overlooked, aspect of model evaluation for robust emissions policy.
Calibration of Raman lidar water vapor profiles by means of AERONET photometer observations and GDAS meteorological data
Authors: Dai Guangyao , Althausen Dietrich , Hofer Julian , Engelmann Ronny , Seifert Patric , Bühl Johannes , Mamouri Rodanthi-Elisavet , Wu Songhua , Ansmann Albert
Published: May 2018

Abstract. We present a practical method to continuously calibrate Raman lidar
observations of water vapor mixing ratio profiles. The water vapor profile
measured with the multiwavelength polarization Raman lidar
PollyXT is calibrated by means of co-located AErosol
RObotic NETwork (AERONET) sun photometer observations and Global Data
Assimilation System (GDAS) temperature and pressure profiles. This method is
applied to lidar observations conducted during the Cyprus Cloud Aerosol and
Rain Experiment (CyCARE) in Limassol, Cyprus. We use the GDAS temperature and
pressure profiles to retrieve the water vapor density. In the next step, the
precipitable water vapor from the lidar observations is used for the
calibration of the lidar measurements with the sun photometer measurements.
The retrieved calibrated water vapor mixing ratio from the lidar measurements
has a relative uncertainty of 11 % in which the error is mainly caused by
the error of the sun photometer measurements. During CyCARE, nine measurement
cases with cloud-free and stable meteorological conditions are selected to
calculate the precipitable water vapor from the lidar and the sun photometer
observations. The ratio of these two precipitable water vapor values yields
the water vapor calibration constant. The calibration constant for the
PollyXT Raman lidar is
6.56 g kg−1 ± 0.72 g kg−1 (with a statistical uncertainty
of 0.08 g kg−1 and an instrumental uncertainty of 0.72 g kg−1).
To check the quality of the water vapor calibration, the water vapor mixing
ratio profiles from the simultaneous nighttime observations with Raman lidar
and Vaisala radiosonde sounding are compared. The correlation of the water
vapor mixing ratios from these two instruments is determined by using all of
the 19 simultaneous nighttime measurements during CyCARE. Excellent agreement
with the slope of 1.01 and the R2 of 0.99 is found. One example is
presented to demonstrate the full potential of a well-calibrated Raman lidar.
The relative humidity profiles from lidar, GDAS (simulation) and radiosonde
are compared, too. It is found that the combination of water vapor mixing
ratio and GDAS temperature profiles allow us to derive relative humidity
profiles with the relative uncertainty of 10–20 %.
Photocurrent modelling and experimental confirmation for Meteor Smoke Particle Detectors onboard atmospheric sounding rockets
Authors: Giono Gabriel , Strelnikov Boris , Asmus Heiner , Staszak Tristan , Ivchenko Nickolay , Lübken Franz-Josef
Published: May 2018

Abstract. Characterizing the photoelectron current induced by the Sun’s UV radiation is crucial to ensure accurate daylight measurements from particle detectors. This article lays out the methodology used to address this problem in the case of the Meteor Smoke Particle Detectors (MSPDs), developed by the Leibniz Institute of Atmospheric Physics in Kühlungsborn (IAP) and to be flown onboard the PMWE (Polar Meosphere Winter Echoes) sounding rockets in mid-April 2018. The methodology focuses on two complementary aspects: modelling and experimental measurements. A detailed model of the MSPD photocurrent was created based on the expected solar UV flux, the atmospheric UV absorption as a function of height by molecular oxygen and ozone, the photoelectric yield of the material coating the MSPD as a function of wavelength, the index of refraction of these materials as a function of wavelength and the angle of incidence of the illumination onto the MSPD. Due to its complex structure composed of a central electrode shielded by two concentric grids, extensive ray tracing calculations were conducted to obtain the incidence angles of the illumination on the central electrode, and this for various orientations of the MSPD with respect to the Sun. Results of the modelled photocurrent at different heights and for different materials, as well as for different orientation of the detector, are presented. As a pre-flight confirmation, the model was used to reproduce the experimental measurements conducted by Robertson et. al. (2014) and agrees within an order of magnitude. An experimental setup for the calibration of the MSPD photocurrent is also presented. The photocurrent induced by the Lyman-alpha line from a deuterium lamp was recorded inside a vacuum chamber using a narrow-band filter, while an UV-sensitive photodiode was used to monitor the UV flux. These measurements were compared with the model prediction, and also matched within the same order of magnitude. Although precisely modelling the photocurrent is a challenging task, this article quantitatively improved the understanding of the photocurrent on the MSPD and discusses possible strategies to untangle the MSP current from the photocurrent recorded in-flight.
The mirror mode: A superconducting space plasma analogue
Authors: Treumann Rudolf A. , Baumjohann Wolfgang
Published: May 2018

Abstract. We re-examine the physics of the magnetic mirror mode in its final state of saturation, the thermodynamic equilibrium, to demonstrate that the mirror mode is the analogue of a superconducting effect in a classical anisotropic-pressure space plasma. Two different spatial scales are identified which control the behaviour of its evolution. These are the ion inertial scale λim(τ) based on the excess density Nm(τ) generated in the mirror mode, and the Debye scale λD(τ). The Debye length plays the role of the correlation length in superconductivity. Their dependence on the temperature ratio τ = T‖ / T⊥  ν⊥th, is exceeded.
Impacts of the horizontal and vertical grids on the numerical solutions of the dynamical equations – Part 2: Quasi-geostrophic Rossby modes
Authors: Konor Celal S. , Randall David A.
Published: May 2018

Abstract. We use a normal-mode analysis to investigate the impacts of the horizontal
and vertical discretizations on the numerical solutions of the
quasi-geostrophic anelastic baroclinic and barotropic Rossby modes on a
midlatitude β plane. The dispersion equations are derived for the
linearized anelastic system, discretized on the Z, C, D, CD, (DC), A, E and B
horizontal grids, and on the L and CP vertical grids. The effects of various
horizontal grid spacings and vertical wavenumbers are discussed. A companion
paper, Part 1, discusses the impacts of the discretization on the
inertia–gravity modes on a midlatitude f plane. The results of our normal-mode analyses for the Rossby waves overall support
the conclusions of the previous studies obtained with the shallow-water
equations. We identify an area of disagreement with the E-grid solution.
Interannual rainfall variability over China in the MetUM GA6 and GC2 configurations
Authors: Stephan Claudia Christine , Klingaman Nicholas P. , Vidale Pier Luigi , Turner Andrew G. , Demory Marie-Estelle , Guo Liang
Published: May 2018

Abstract. Six climate simulations of the Met Office Unified Model Global
Atmosphere 6.0 and Global Coupled 2.0 configurations are evaluated against
observations and reanalysis data for their ability to simulate the mean state
and year-to-year variability of precipitation over China. To analyse the
sensitivity to air–sea coupling and horizontal resolution, atmosphere-only
and coupled integrations at atmospheric horizontal resolutions of N96, N216
and N512 (corresponding to ∼ 200, 90 and 40 km in the zonal direction
at the equator, respectively) are analysed. The mean and interannual variance
of seasonal precipitation are too high in all simulations over China but
improve with finer resolution and coupling. Empirical orthogonal
teleconnection (EOT) analysis is applied to simulated and observed
precipitation to identify spatial patterns of temporally coherent interannual
variability in seasonal precipitation. To connect these patterns to
large-scale atmospheric and coupled air–sea processes, atmospheric and
oceanic fields are regressed onto the corresponding seasonal mean time series.
All simulations reproduce the observed leading pattern of interannual
rainfall variability in winter, spring and autumn; the leading pattern in
summer is present in all but one simulation. However, only in two simulations
are the four leading patterns associated with the observed physical
mechanisms. Coupled simulations capture more observed patterns of variability
and associate more of them with the correct physical mechanism, compared to
atmosphere-only simulations at the same resolution. However, finer resolution
does not improve the fidelity of these patterns or their associated
mechanisms. This shows that evaluating climate models by only geographical
distribution of mean precipitation and its interannual variance is
insufficient. The EOT analysis adds knowledge about coherent variability and
associated mechanisms.
Comment on “Origin of water in the Badain Jaran Desert, China:
new insight from isotopes” by Wu et al. (2017)
Authors: Zhan Lucheng , Chen Jiansheng , Li Ling , Barry David Andrew
Published: May 2018

Abstract. Precipitation isotope data were used to determine the origin of groundwater in the Badain Jaran Desert (BJD) in the study of Wu et al. (2017). Both precipitation and its isotopic composition vary seasonally, so arithmetic averages of precipitation isotope values poorly represent the isotope composition of meteoric water. Their finding that the BJD groundwater is recharged by modern meteoric water from local areas including the southeastern adjacent mountains was based on arithmetic averaging. However, this conclusion is not supported by the corrected mean precipitation isotope values, which are weighted by the precipitation rate. Indeed, the available isotopic evidence shows that modern precipitation on the Qilian Mountains is more likely to be the main source of the groundwater and lake water in the BJD, as found by Chen et al. (2004).
Comparison of MODIS and SWAT evapotranspiration over a complex terrain at different spatial scales
Authors: Abiodun Olanrewaju O. , Guan Huade , Post Vincent E. A. , Batelaan Okke
Published: May 2018

Abstract. In most hydrological systems, evapotranspiration (ET) and precipitation are the largest components of the water balance, which are difficult to estimate, particularly over complex terrain. In recent decades, the advent of remotely sensed data based ET algorithms and distributed hydrological models has provided improved spatially upscaled ET estimates. However, information on the performance of these methods at various spatial scales is limited. This study compares the ET from the MODIS remotely sensed ET dataset (MOD16) with the ET estimates from a SWAT hydrological model on graduated spatial scales for the complex terrain of the Sixth Creek Catchment of the Western Mount Lofty Ranges, South Australia. ET from both models was further compared with the coarser-resolution AWRA-L model at catchment scale. The SWAT model analyses are performed on daily timescales with a 6-year calibration period (2000–2005) and 7-year validation period (2007–2013). Differences in ET estimation between the SWAT and MOD16 methods of up to 31, 19, 15, 11 and 9 % were observed at respectively 1, 4, 9, 16 and 25 km2 spatial resolutions. Based on the results of the study, a spatial scale of confidence of 4 km2 for catchment-scale evapotranspiration is suggested in complex terrain. Land cover differences, HRU parameterisation in AWRA-L and catchment-scale averaging of input climate data in the SWAT semi-distributed model were identified as the principal sources of weaker correlations at higher spatial resolution.
How downstream sub-basins depend on upstream inflows to avoid scarcity: typology and global analysis of transboundary rivers
Authors: Munia Hafsa Ahmed , Guillaume Joseph H. A. , Mirumachi Naho , Wada Yoshihide , Kummu Matti
Published: May 2018

Abstract. Countries sharing river basins are often dependent upon water originating
outside their boundaries; meaning that without that upstream water, water
scarcity may occur with flow-on implications for water use and management.
We develop a formalisation of this concept drawing on ideas about the transition
between regimes from resilience literature, using water stress and water
shortage as indicators of water scarcity. In our analytical framework,
dependency occurs if water from upstream is needed to avoid scarcity. This
can be diagnosed by comparing different types of water availability on which
a sub-basin relies, in particular local runoff and upstream inflows. At the
same time, possible upstream water withdrawals reduce available water
downstream, influencing the latter water availability. By developing a
framework of scarcity and dependency, we contribute to the understanding of
transitions between system regimes. We apply our analytical framework to
global transboundary river basins at the scale of sub-basin areas (SBAs). Our
results show that 1175 million people live under water stress (42 % of the
total transboundary population). Surprisingly, the majority (1150 million) of these currently suffer
from stress only due to their own excessive water use and possible water from
upstream does not have impact on the stress status – i.e. they are not yet
dependent on upstream water to avoid stress – but could still impact on the
intensity of the stress. At the same time, 386 million people (14 %) live
in SBAs that can avoid stress owing to available water from upstream and have
thus upstream dependency. In the case of water shortage, 306 million people
(11 %) live in SBAs dependent on upstream water to avoid possible shortage.
The identification of transitions between system regimes sheds light on how
SBAs may be affected in the future, potentially contributing to further refined
analysis of inter- and intrabasin hydro-political power relations and
strategic planning of management practices in transboundary basins.
Testing the effects of topography, geometry, and kinematics on modeled thermochronometer cooling ages in the eastern Bhutan Himalaya
Authors: Gilmore Michelle E. , McQuarrie Nadine , Eizenhöfer Paul R. , Ehlers Todd A.
Published: May 2018

Abstract. In this study, reconstructions of a balanced geologic cross section in the Himalayan fold–thrust belt of eastern Bhutan are used in flexural–kinematic and thermokinematic models to understand the sensitivity of predicted cooling ages to changes in fault kinematics, geometry, topography, and radiogenic heat production. The kinematics for each scenario are created by sequentially deforming the cross section with  ∼ 10 km deformation steps while applying flexural loading and erosional unloading at each step to develop a high-resolution evolution of deformation, erosion, and burial over time. By assigning ages to each increment of displacement, we create a suite of modeled scenarios that are input into a 2-D thermokinematic model to predict cooling ages. Comparison of model-predicted cooling ages to published thermochronometer data reveals that cooling ages are most sensitive to (1) the location and size of fault ramps, (2) the variable shortening rates between 68 and 6.4 mm yr−1, and (3) the timing and magnitude of out-of-sequence faulting. The predicted ages are less sensitive to (4) radiogenic heat production and (5) estimates of topographic evolution. We used the observed misfit of predicted to measured cooling ages to revise the cross section geometry and separate one large ramp previously proposed for the modern décollement into two smaller ramps. The revised geometry results in an improved fit to observed ages, particularly young AFT ages (2–6 Ma) located north of the Main Central Thrust. This study presents a successful approach for using thermochronometer data to test the viability of a proposed cross section geometry and kinematics and describes a viable approach to estimating the first-order topographic evolution of a compressional orogen.