bluuebunny/crossref_metadata_2025 huggingface dataset:
Multimodel emission metrics for regional emissions of short lived climate forcers
Authors: Aamaas B. , Berntsen T. K. , Fuglestvedt J. S. , Shine K. P. , Bellouin N.
Published: September 2015

Abstract. For short lived climate forcers (SLCFs), the impact of emissions depends on where and when the emissions take place. Comprehensive new calculations of various emission metrics for SLCFs are presented based on radiative forcing (RF) values calculated in four different (chemistry-transport or coupled-chemistry climate) models. We distinguish between emissions during summer (May–October) and winter season (November–April) for emissions from Europe, East Asia, as well as the global shipping sector. The species included in this study are aerosols and aerosols precursors (BC, OC, SO2, NH3), and ozone precursors (NOx, CO, VOC), which also influence aerosols, to a lesser degree. Emission metrics for global climate responses of these emissions, as well as for CH4, have been calculated relative to CO2, using Global Warming Potential (GWP) and Global Temperature change Potential (GTP), based on dedicated RF simulations by four global models. The emission metrics include indirect cloud effects of aerosols and the semi-direct forcing for BC. In addition to the standard emission metrics for pulse and sustained emissions, we have also calculated a new emission metric designed for an emission profile consisting of a ramp up period of 15 years followed by sustained emissions, which is more appropriate for a gradual implementation of mitigation policies. For the aerosols, the emission metric values are larger in magnitude for Europe than East Asia and for summer than winter. A variation is also observed for the ozone precursors, with largest values in East Asia and winter for CO and in Europe and summer for VOC. In general, the variations between the emission metrics derived from different models are larger than the variations between regions and seasons, but the regional and seasonal variations for the best estimate also hold for most of the models individually. Further, the estimated climate impact of a mitigation policy package is robust even when accounting for correlations. For the ramp up emission metrics, the values are generally larger than for pulse or sustained emissions, which holds for all SLCFs. For a potential SLCFs mitigation policy, the dependency of metric values on the region and season of emission should be considered.
The importance of temporal collocation for the evaluation of aerosol models with observations
Authors: Schutgens N. A. J. , Partridge D. G. , Stier P.
Published: September 2015

Abstract. It is often implicitly assumed that over suitably long periods the mean of observations and models should be comparable, even if they have different temporal sampling. We assess the errors incurred due to ignoring temporal sampling and show they are of similar magnitude as (but smaller than) actual model errors (20–60 %). Using temporal sampling from remote sensing datasets (the satellite imager MODIS and the ground-based sun photometer network AERONET) and three different global aerosol models, we compare annual and monthly averages of full model data to sampled model data. Our results show that sampling errors as large as 100 % in AOT (Aerosol Optical Thickness), 0.4 in AE (Ångström Exponent) and 0.05 in SSA (Single Scattering Albedo) are possible. Even in daily averages, sampling errors can be significant. More-over these sampling errors are often correlated over long distances giving rise to artificial contrasts between pristine and polluted events and regions. Additionally, we provide evidence that suggests that models will underestimate these errors. To prevent sampling errors, model data should be temporally collocated to the observations before any analysis is made. We also discuss how this work has consequences for in-situ measurements (e.g. aircraft campaigns or surface measurements) in model evaluation.
Transport across the tropical tropopause layer and convection
Authors: Tissier A.-S. , Legras B.
Published: September 2015

Abstract. Transit properties across the tropical tropopause layer are studied using extensive forward and backward Lagrangian trajectories between cloud tops and the reference surface 380 K. The tropical domain being subdivided into 11 sub-regions according to the distribution of land and convection, we estimate the contribution of each region to the upward mass flux across the 380 K surface, the vertical distribution of convective sources and of transit times over the period 2005–2008. The good agreement between forward and backward statistics is the basis of the results presented here. It is found that about 85 % of the tropical parcels at 380 K originate from convective sources all along the year. From November to April, the sources are dominated by the warm pool which accounts for up to 70 % of the upward flux. During summer, Asian monsoon region is the largest contributor with similar contributions from oceanic regions and Asian mainland, although the signature in vertical distribution and transit time is very different, Asian mainland displaying higher sources and smaller transit times. The Tibetan plateau, although a minor overall contributor, is found to be the region with the highest impact of convection at 380 K due to its central location beneath the Asian upper level anticyclone. We show the robustness of our main results to uncertainties in data and methods but we also find some sensitivity of the vertical distribution of sources and transit times to the representation of cloud tops and heating rates.
ESCIMO.spread (v2): parameterization of a spreadsheet-based energy balance snow model for inside-canopy conditions
Authors: Marke T. , Mair E. , Förster K. , Hanzer F. , Garvelmann J. , Pohl S. , Warscher M. , Strasser U.
Published: September 2015

Abstract. This article describes the extension of the spreadsheet-based point energy balance snow model ESCIMO.spread by (i) an advanced approach for precipitation phase detection, (ii) a concept for cold and liquid water storage consideration and (iii) a canopy sub-model that allows to quantify the effect of a forest canopy on the meteorological conditions inside the forest as well as the simulation of snow accumulation and ablation inside a forest stand. To provide the data for model application and evaluation, innovative low-cost Snow Monitoring Systems (SnoMoS) have been utilized that allow the collection of important meteorological and snow information in and outside the canopy. The model performance with respect to both, the modification of meteorological conditions as well as the subsequent calculation of the snow cover evolution are evaluated using in- and outside-canopy observations of meteorological variables and snow cover evolution as provided by a pair of SnoMoS for a site in the Black Forest mountain range (south-west Germany). The validation results indicate a good overall model performance in and outside the forest canopy. The newly developed version of the model refered to as ESCIMO.spread (v2) is provided free of charge together with one year of sample data including the meteorological data and snow observations used in this study.
Technical Note: The use of an interrupted-flow centrifugation method to characterise preferential flow in low permeability media
Authors: Crane R. A. , Cuthbert M. O. , Timms W.
Published: September 2015

Abstract. We present an interrupted-flow centrifugation technique to characterise preferential flow in low permeability media. The method entails a minimum of three phases: centrifuge-induced flow, no flow and centrifuge-induced flow, which may be repeated several times in order to most effectively characterise multi-rate mass transfer behaviour. In addition, the method enables accurate simulation of relevant in situ total stress conditions during flow by selecting an appropriate centrifugal force. We demonstrate the utility of the technique for characterising the hydraulic properties of smectite-clay-dominated core samples. All core samples exhibited a non-Fickian tracer breakthrough (early tracer arrival), combined with a decrease in tracer concentration immediately after each period of interrupted flow. This is indicative of dual (or multi-)porosity behaviour, with solute migration predominately via advection during induced flow, and via molecular diffusion (between the preferential flow network(s) and the low hydraulic conductivity domain) during interrupted flow. Tracer breakthrough curves were simulated using a bespoke dual porosity model with excellent agreement between the data and model output (Nash–Sutcliffe model efficiency coefficient was > 0.97 for all samples). In combination, interrupted-flow centrifuge experiments and dual porosity transport modelling are shown to be a powerful method to characterise preferential flow in low permeability media.
Reviving the "Ganges Water Machine": where and how much?
Authors: Muthuwatta L. , Amarasinghe U. A. , Sood A. , Lagudu S.
Published: September 2015

Abstract. Surface runoff generated in the monsoon months in the upstream parts of the Ganges River Basin contributes substantially to downstream floods, while water shortages in the dry months affect agricultural production in the basin. This paper examines the parts (sub-basins) of the Ganges that have the potential for augmenting subsurface storage (SSS), increase the availability of water for agriculture and other uses, and mitigate the floods in the downstream areas. The Soil and Water Assessment Tool (SWAT) is used to estimate sub-basin-wise water availability. The water availability estimated is then compared with the sub-basin-wise un-met water demand for agriculture. Hydrological analyses revealed that five sub-basins produced more than 10 billion cubic meters (B m3) of annual surface runoff consistently during the simulation period. In these sub-basins, less than 50 % of the annual surface runoff is sufficient to irrigate all irrigable land in both the \\textit{Rabi} (November to March) and summer (April to May) seasons. Further, for most of the sub-basins, there is sufficient water to meet the un-met water demand, provided that it is possible to capture the surface runoff during the wet season. It is estimated that the average flow to Bihar State from the upstream of the Ganges, a downstream basin location, is 277 ± 121 B m3, which is more than double the rainfall in the state alone. Strong relationships between outflows from the upstream sub-basins and the inflows to Bihar State suggested that flood inundation in the state could be reduced by capturing a portion of the upstream flows during the peak runoff periods.
Stream flow recession patterns can help unravel the role of climate and humans in landscape co-evolution
Authors: Bogaart P. W. , van der Velde Y. , Lyon S. W. , Dekker S. C.
Published: September 2015

Abstract. Traditionally, long term predictions of river discharges and their extremes include constant relationships between landscape properties and model parameters. However, due to co-evolution of many of landscape properties more sophisticated methods to quantify future landscape-hydrological model relationships are likely necessary. As a first step towards such an approach we use the Brutsaert and Nieber (1977) analysis method to characterize streamflow recession behaviour of ≈ 200 Swedish catchments within the context of global change and landscape co-evolution. Results suggest that the Brutsaert–Nieber parameters are strongly linked to the climate, soil, land-use and their interdependencies. Many catchments show a trend towards more non-linear behaviour, meaning faster initial recession, but also slower recession towards baseflow. This trend has been found to be independent from climate change. Instead, we suggest that land cover change, both natural (restoration of natural soil profiles in forested areas) and anthropogenic (reforestation and optimized water management), is probably responsible. Both change types are characterised by system adaptation and change, towards more optimal ecohydrological conditions, suggesting landscape co-evolution is at play. Given the observed magnitudes of recession changes during the past 50 years, predictions of future river discharge critically need to include effects of landscape co-evolution. The interconnections between the controls of land cover and climate on river recession behaviour, as we have quantified in this paper, provide first-order handles to do so.
Spatio-temporal variability of micro-, nano- and pico-phytoplankton in the Mediterranean Sea from satellite ocean colour data of SeaWiFS
Authors: Sammartino M. , Di Cicco A. , Marullo S. , Santoleri R.
Published: September 2015

Abstract. The seasonal and year-to-year variability of the phytoplankton size class (PSC) spatial distribution has been examined in the Mediterranean Sea by using the entire time series of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) space observations (1998–2010). Daily maps of PSCs have been determined using an empirical model based on a synoptic relationship between surface chlorophyll a and diagnostic pigments referred to different taxonomic groups. The analysis of micro-, nano- and pico-phytoplankton satellite time series (1998–2010) describes, quantitatively, the algal assemblage structure over the basin and reveals that the main contribution to chlorophyll a in most of the Mediterranean Sea comes from the pico-phytoplankton component, especially in nutrient-poor environments. Regions with different and peculiar features are the Northwestern Mediterranean Sea, the Alborán Sea and several coastal areas, such as the North Adriatic Sea. In these areas, local interactions between physical and biological components modulate the composition of the three phytoplankton size classes. It results that, during the spring bloom season, micro-phytoplankton dominates in areas of intense vertical winter mixing and deep/intermediate water formation, while in coastal areas micro-phytoplankton dominates in all seasons because of the nutrient supply from the terrestrial inputs. In the Alborán Sea, where the Atlantic inflow modulates the nutrient availability, any predominance of one class over the other two has been observed. The nano-phytoplankton component instead remains widespread over the entire basin along the year, and its contribution to chlorophyll a is of the order of 30–40 %. The largest inter-annual signal occurs in the Northwestern Mediterranean Sea, driven by the year-to-year variation in intensity and extension of the spring bloom, followed by the Alborán Sea, in which the inter-annual variability is strongly modulated by the Atlantic inflow. In absence of sufficient in situ data of community composition, the satellite-based analysis demonstrated that pico-, nano- and micro-phytoplankton classes often coexist. The predominance of one group over the other ones is strongly dependent on the physical and biological processes occurring at the mesoscale. These processes directly influence the nutrient and light availability, which are the principal forcing for the algae growth.
Tree shrews at the German Primate Center
Authors: Fuchs E.
Published: September 2015

Abstract. For many years, Tupaia (family Tupaiidae), most commonly known as tree shrews, have been studied almost exclusively by zoologists resulting in a controversial debate on their taxonomic status among mammals. Today, tree shrews are placed in the order Scandentia; they are valuable, widely accepted and increasingly used model animals as an alternative to rodents and non-human primates in biomedical research. After a brief description on how tree shrews entered science and their taxonomic odyssey, the present article describes the history of the tree shrew (Tupaia belangeri) colony at the German Primate Center and selected aspects of our work with special emphasis on the psychosocial stress model in these animals.
Command-And-Control or Taxation? The Cases of Water Regulation in California and Denmark
Authors: H Christina , Svendsen Gert Tinggaard
Published: September 2015

California and Denmark are both facing water scarcity issues as demand has increased and supply has decreased over the years. In order to solve this problem these two actors have chosen very different ways of dealing with sustaining an adequate amount of domestic water supply. California has chosen an ineffective command-and-control (CAC) tool, whereas Denmark has chosen the effective tool of taxation. One main explanation for this variation in policy choice is the variation in institutional setups, namely the corporatist route in Denmark versus the pluralistic route in California.
PD-L1 Gene Polymorphism and High Level of Plasma Soluble Pd-L1 Protein may be aSsociated with Non-Small Cell Lung Cancer
Authors: Cheng Sensen , Zheng Jinsong , Zhu Jingyan , Xie Chao , Zhang Xia , Han Xiao , Song Bao , Ma Yuan , Liu Jie
Published: September 2015

Background

PD-1 and its ligand PD-L1 belong to the co-inhibition molecules, which can downregulate immune responses. The PD-L1 polymorphism and the level of soluble PD-L1 (sPD-L1) were investigated in non-small cell lung cancer (NSCLC).

Methods

A total of 288 NSCLC patients and 300 controls were enrolled. An A/C polymorphism at position 8923 in the PD-L1 gene was genotyped using the polymerase chain reaction-restriction fragment length polymorphism method.

Results

The prevalence of the 8923C allele was significantly higher in NSCLC patients than controls (10.2% versus 5.3%, p = 0.002, odds ratio 2.03, 95% confidence interval 1.30-3.17; data were adjusted for age and sex). NSCLC patients also showed increased plasma levels of sPD-L1 compared to controls (1.92 ng/mL versus 0.91 ng/mL, p<0.001). Furthermore, lung adenocarcinoma patients had higher sPD-L1 levels than patients with squamous cell carcinoma (p<0.01). However, no association was observed between the different genetic variants and plasma concentrations of sPD-L1.

Conclusions

The PD-L1 8923A/C polymorphism could be associated with increased susceptibility to NSCLC. Plasma levels of sPD-L1 are significantly increased in NSCLC patients, especially those with adenocarcinoma.
An Affordable and Easily Constructed Model for Training in Ultrasound-guided Vascular Access
Authors: Rippey James C.R. , Blanco Pablo , Carr Peter J.
Published: September 2015

Purpose

This paper describes a simple and inexpensive method to make high-fidelity simulators for use in ultrasound-guided vascular access teaching. The phantoms can be created to reflect the ultrasound appearance and feel of central or peripheral arteries and veins. Different clinical states such as hypovolaemia may be readily displayed using the phantoms.

Methods

The article and associated videos describe the production, appearance and use of phantoms for central vascular access, for peripheral venous access and for peripheral arterial access. Key ingredients are readily accessible and include chicken breasts, modelling balloons and thin walled latex or silicone tubing.

Results

The phantoms are easily and rapidly constructed and may be used repeatedly in a training session. As the needle passes through the phantom and vessel wall, the ultrasound appearance and tactile sensation is very similar to that of human tissue and vessels.

Conclusions

Using this method, simple and inexpensive phantoms can be created. These are ideal for use in training for ultrasound-guided vascular access. Links to videos describing the phantom construction process, their appearance and the teaching techniques utilised by the authors are found in the text.
Evaluation of Sterilization using the MEH200® (Cotton Pack) in Vascular Access Puncture
Authors: Ueda Yuka , Tsuchida Kenji , Okada Daigo , Muromiya Yasuto , Suenaga Takehiro , Yokota Narushi , Kawahara Kana , Nagai Kojiro , Kanayama Hiro-omi , Minakuchi Jun
Published: September 2015

Background

In recent years, chlorhexidine-alcohol has been attracting increasing attention for its role in skin antisepsis. There have been few reports on the infection frequency associated with vascular access and no reports on the infection frequency associated with antiseptics.

Aims

We investigated skin disinfection during vascular access puncture in patients on chronic hemodialysis (HD).

Methods

We analyzed patients on chronic HD with arteriovenous fistula (AVF) and arteriovenous graft (AVG) between January 2006 and December 2010.

Results

The MEH200® (cotton pack including alcohol and chlorhexidine gluconate) was used in 97% of patients. A total of 1130 patients were analyzed, including 911 with AVF and 219 with AVG. Of these, seven with AVF had an infection attributed to the insertion site, which represented a rate of 0.008% of patients per year. Twenty patients with AVG had an infection attributed to the insertion site, which represented a rate of 9.1% of patients per year. The frequency was not higher than that previously reported.

Conclusions

In HD patients, the MEH200® may be effective for the prevention of bacteremia.
Outcomes of Blood Flow Suppression Methods of Treating High Flow Access in Hemodialysis Patients with Arteriovenous Fistula
Authors: Kanno Taro , Kamijo Yuji , Hashimoto Koji , Kanno Yutaka
Published: September 2015

Purpose

A high flow access (HFA) may cause heart failure in patients with an arteriovenous fistula (AVF) undergoing hemodialysis (HD) and is associated with poor prognosis. There are a variety of blood flow suppression techniques for treating HFA; however, the therapeutic outcome is still unclear.

Methods

The following three different blood flow suppression methods were performed on 74 patients with HFA: proximal artery banding with distal artery ligation (A-ban with A-lig: 12 cases); shunt vein banding (V-ban: 37 cases); and anastoplasty (Ana: 25 cases).

Results

There were no differences in the sex or mean age or duration of HD between the treatment groups. The A-ban with A-lig method was mainly selected for patients with a distal AVF and the anastoplasty method was selected most often for patients with a cubital AVF. The techniques were equally effective in reducing flow volume (FV) and the FV/cardiac output ratio (Flow/CO) to target levels, and clinical symptoms improved in all patients. The rates of HFA recurrence and AVF occlusion were significantly higher in the V-ban group (18.9% and 24.3%, respectively). A small proportion of patients in each treatment group developed a postoperative infection.

Conclusions

Each method proved to be an effective means of treating HFA. The choice of surgical method should be informed by the type of vascular access; however, the A-ban with A-lig and Ana methods appear to achieve clinically significant reductions in FV and have lower rates of HFA recurrence and AVF occlusion.
Use of Long-Term Catheters in Japan: Implant Procedures, Maintenance Methods, and Future Aspects
Authors: Miyata Akira , Hamanoue Satoshi , Kawabata Chiaki , Maekawa Ai , Toyoda Mariko , Arita Tomomi , Uekihara Souichi , Hayano Shunnichi
Published: September 2015

The Japanese society for dialysis therapy (JSDT) launched the second edition of ‘Guidelines for Vascular Access Construction and Repair for Chronic Hemodialysis’ concerning the vascular access in 2011. The indication of long-term catheters is strictly limited in these guidelines because of possible high risks of infections including sepsis and obstruction of catheters with thrombus. In Japan, the long-term catheters would be needed more frequently to prepare the very rapid demographic change within a decade, under the condition that the material and structure of these catheters will be more resistant against the complications.
Vascular Access Intervention by a Nephrologist in Hiroshima
Authors: Doi Shigehiro , Masaki Takao
Published: September 2015

Background

Vascular access intervention (VAI) is a procedure essential to the maintenance of patency in vascular access and has become indispensable to nephrologists. This procedure has changed nephrology to a more exciting field.

Concept

This report describes the VAI technique which is based on 15 years of treatment experience of the author of this report and which the author has taught to young nephrologists in Hiroshima.
Is Bypass Graft Technique Effective in Arteriovenous Graft?
Authors: Noguchi Tomonaga , Miyamoto Masahito , Kataoka Kazuyoshi , Sato Kazuhiro , Nihei Hiroshi , Takeda Isao , Inoue Keiji , Sasagawa Naru , Chiba Tetsuo
Published: September 2015

Background

Arteriovenous graft (AVG) requires percutaneous transluminal angioplasty (PTA) to maintain its patency; however, bypass graft technique is often chosen in cases requiring PTA again within 3 months. We retrospectively examined whether bypass graft technique is effective for AVG.

Methods

The sample patient population consisted of 50 patients who underwent bypass graft technique on the venous side of the AVG between April 2012 and March 2014. The primary and assisted patencies of the technique were calculated, and compared by the type and length of the bypass graft. Kaplan-Meier method and log-rank test were used for the calculation and comparison of the patency, respectively. p<0.05 was considered statistically significant.

Results

The reasons for surgery were thrombotic occlusion (27 cases), frequent PTA (15 cases) and others (8 cases). Frequent PTA was conducted within 3 months in 22 of 27 thrombotic occlusion cases (making 37/50, or 74%). Moreover, thrombectomy was required in 34 cases (68%). The 1-year primary and 1-year assisted patencies of the technique were 6.5% and 72.6%, respectively. When the endpoint was frequent PTA within 3 months after the technique, 1-year primary patency was 45.9%.

Conclusions

The 1-year primary patency of the technique was poor, and patency was hard to maintain without the assistance of PTA. Given that frequent PTA was conducted in 74% of patients, it may be a cause for the poor patency. Many cases required thrombectomies, which have the disadvantage of being more invasive than PTA. We concluded that bypass graft technique is not valuable for cases that received frequent PTA.
Reduction or Discontinuation of Antibiotic Prophylaxis in Vascular Access Surgery, Tendon Sheath Incision and PD Catheter Placement
Authors: Nagai Kojiro , Tsuchida Kenji , Sasada Maki , Yokota Narushi , Nishitani Masaaki , Kanayama Hiro-omi , Minakuchi Jun
Published: September 2015

Purpose

Immune response in dialysis patients is suppressed and these patients are susceptible to bacterial infections. Therefore, minimal use of antibiotics in dialysis patients is recommended to avoid generating drug-resistant bacteria. However, minor surgeries including vascular access surgery, tendon sheath incision and peritoneal dialysis (PD) catheter placement are inevitable in dialysis patients and evidence-based recommendations on the judicious use of antibiotics are not currently available for these procedures. In this study, the optimal antibiotic prophylaxis for minor surgeries was evaluated.

Methods

This is a retrospective study. In dialysis patients at Kawashima Hospital, a three-step reduction of antibiotic use was performed in 651 cases of arteriovenous fistula (AVF) and tendon sheath incision surgeries from July 2009 through October 2012. Moreover, general surgical guidelines-recommended dose of preoperative antibiotics only were used in 532 cases of arteriovenous graft (AVG) and PD catheter placement from January 2010 through October 2012. The surgical site was observed for 2 weeks after the surgery.

Results

In only one case of AVF surgery, redness of the skin around the stitches was noticed 5 days after the surgery, which was healed with antibiotics taken orally for 3 days. Neither AVG nor PD catheter placement demonstrated any infection at the surgical site during the 2-week observation period.

Conclusions

Even in dialysis patients, neither pre- nor postoperative antibiotics are necessary for AVF and tendon sheath incision surgeries. AVG and PD catheter placement surgeries require only a small amount of antibiotics preoperatively.
Percutaneous Transluminal Angioplasty in Japan: Five-Center Investigation
Authors: Murakami Masaaki , Miyamoto Masahito , Suemitsu Kotaro
Published: September 2015

Purpose

Percutaneous transluminal angioplasty (PTA) is the first-line treatment for vascular access stenosis. To our knowledge, multicenter clinical research of PTA has not been reported in Japan. We examined the efficacy and safety of PTA for arteriovenous fistula (AVF) and arteriovenous graft (AVG) in five centers of Japan.

Methods

Three hundred cases of angioplasty for AVF and 300 for AVG were examined in three centers each. A hundred consecutive patients from each center who underwent PTA for AVG or AVF prior to March 2014 and met the inclusion criteria were searched retrospectively. Primary patency rates were estimated using the Kaplan-Meier method.

Results

The mean age was 69.3 ± 11.2 years in the AVF group and 70.2 ± 11.9 years in the AVG group. The anatomical success rates were 51.7% (155 of 300) in the AVF group and 72.0% (216 of 300) in the AVG group. The clinical success rates were 99.7% (299 of 300) in the AVF group and 100% (300 of 300) in the AVG group. A total of 25 complications (4.17%) were encountered in both groups including one major complication (0.17%). The primary patency was 99.0% at 1 month, 87.9% at 3 months and 51.7% at 6 months in the AVF group, and 96.0% at 1 month, 64.8% at 3 months and 20.4% at 6 months in the AVG group.

Conclusions

The clinical success rate of PTA in five centers was relatively high and a major complication rate was only 0.17%. However, anatomical success rates were low comparing with the previous studies and the primary patency rates were inferior to the past data.
Vascular access in super-aged patients
Authors: Kawanishi Hideki , Shintaku Sadanori , Moriishi Misaki
Published: September 2015

Purpose

In developed countries, dialysis patients are aging along with the general population. The choice of vascular access (VA) is a more complex decision among elderly patients and is not specifically addressed by clinical practice guidelines. We investigated the relationship between the VA type at dialysis initiation in elderly patients and their prognosis, as well as the selection of the optimal VA type.

Methods

We conducted a retrospective observational cohort study of consecutive adult patients (age ≥18 years) as their first form of renal replacement therapy (RRT) between January 1, 2003, and December 31, 2010. For this study, VA included both arteriovenous fistula (AVF) and temporary central venous catheter (CVC).

Results

A total of 402 patients were included in this study. The percentage of patients who started dialysis with CVC increased with age, and 63% of those were over 80 years. The survival rate in the group of elderly patients (≥70 years) using CVC at dialysis initiation was significantly lower. In contrast, the survival rates were comparable between nonelderly patients (<70 years) using CVC or AVF. One hundred and thirty patients were super-aged (≥80 years). In super-aged patients (≥80 years) and aged patients (70-79 years), dialysis initiation with CVC was correlated with a significantly poorer survival rate than dialysis initiation with AVF. The survival rates were comparable between the low CRP group (<1.8 mg/dL) using CVC or AVF.

Conclusions

The initiation of dialysis with temporary CVC is not a risk factor of death in nonelderly patients (<70 years). On the other hand, in elderly (≥70 years) and super-aged (≥80 years) patients, dialysis initiation with CVC increased the risk of death, but they had to start dialysis with CVC on an emergency basis because of their clinical condition, that is, inflammations.
Central Venous Access Devices Site Care Practices: An International Survey of 34 Countries
Authors: Broadhurst Daphne , Moureau Nancy , Ullman Amanda J.
Published: September 2015

Purpose

Effective postinsertion management of central venous access devices (CVADs) is important to prevent CVAD-associated complications, including catheter-associated bloodstream infections. Although there is a wealth of evidence-based guidelines available to guide the care of CVADs, applying their recommendations to the clinical setting across variable patient groups, CVAD types and international healthcare settings is challenging. This may result in patients receiving suboptimal care.

Methods

A cross-sectional descriptive study using an online survey was performed with an aim to determine current CVAD site care practices internationally. The CVAD site care domains included skin antisepsis, dressing selection, frequency of dressing change and device securement practices across impaired and unimpaired CVAD sites.

Results

Clinicians (n = 1044) residing in 34 countries reported diversity in their practice, with the majority of respondents practicing as nurses (89%) from North America (81%) as vascular access specialists (52%). The respondents’ reported practice was variant, with differing inconsistency to guidelines throughout each of the domains. There was wide variance in the management of CVAD sites with impaired skin integrity, such as rash, skin stripping/adhesive-related injuries and drainage. Vascular access clinicians reported high levels of confidence in managing CVAD sites, including those with impaired skin.

Conclusions

These inconsistencies are reflective of the complex and heterogeneous populations requiring CVADs, the evidence available to support practice in this area, the skills and knowledge of the clinicians caring for them and the resources of the healthcare setting. Further research and education is necessary to ensure that CVAD site care is undertaken effectively to minimise preventable complications.
The Impact of Tunnelled Vascular Catheters on Time to Arteriovenous Fistula Creation
Authors: Nandakoban Hareeshan , Aravindan Ananthakrishnapuram , Spicer Tim , Narayanan Govind , Gonzalez Noemir , Suranyi Michael , Wong Jeffrey K.W.
Published: September 2015

Purpose

The purpose of this study is to examine the effect of the presence of tunnelled vascular catheter (TVC) on physician referral and surgeon review and operating patterns and ultimately time of creation of permanent haemodialysis (HD) access.

Methods

A retrospective analysis of TVC and arteriovenous fistulae (AVF) databases in 2010. Physician referral time and surgical time to operation were compared between patients commencing HD with TVC and a control group who commenced HD with AVF.

Results

The AVF group (n = 27) commenced HD with an AVF and TVC group (n = 49) commenced HD via a TVC. Time from physician referral to surgeon review in the AVF vs. TVC group was 29 vs. 35 days (p = 0.6). Time from surgeon review to access creation was 43 vs. 50 days (p = 0.4). However, in the TVC group, the time from TVC insertion to physician referral to a surgeon was an additional 109 ± 20 days. Subgroup analysis of 11 TVC patients (23%) presenting at end stage without AVF (crash starters) had a TVC to physician referral time of 103 ± 75 days, physician referral to surgeon review of 14.4 ± 4 days and surgeon review to AVF of 67 ± 23 days.

Conclusions

The presence of a TVC is associated with a significant delay (>3 months) before physicians make a referral for surgeon review. There was no surgeon-related delay to access creation related to the presence of a TVC.
No-Touch Technique for Radiocephalic Arteriovenous Fistula – Surgical Technique and Preliminary Results
Authors: Hörer Tal M. , Skoog Per , Quell Robin , Nilsson Kristofer F. , Larzon Thomas , Souza Domingos R.
Published: September 2015

Purpose

The radiocephalic arteriovenous fistula (RC-AVF) has significant failure rates due to occlusions and failure to mature. The size and quality of the veins are considerable limiting factors for the procedure. The aim of this pilot study was to describe the No-Touch technique (NTT) to create RC-AVF and present the results up to 1 year of follow-up.

Methods

Thirty-one consecutive patients who were referred for surgery for a RC-AVF were included (17 men, mean age 63 years, range 35-84) and operated by NTT where the vein and artery were dissected with a tissue cushion around it. Twenty-two patients had small veins or arteries (≤2 mm), 12 patients had a small cephalic vein (≤2 mm), and the mean distal cephalic vein diameter was 2.4 mm (range 1.0-4.1 mm).

Results

Technical surgical success and immediate patency were obtained in all patients. Clinical success was achieved in 23 of the 27 (85%) patients who required hemodialysis. The proportion of primary patency at 30 days and 6 months was 84% and 64%, respectively. Secondary patency at 30 days and 6 months was 97% and 83%, respectively. At 1-year follow-up, primary patency was 54% and secondary patency was 80%. There was no major difference in patency due to preoperative vein diameter.

Conclusions

The results of this study indicate that NTT can be used for primary radio-cephalic fistula surgery with very good results. This method offers the potential to create a RC-AVF in patients who are not usually considered appropriate for a distal arm fistula due to a small cephalic vein.
Peripherally Inserted Central Catheter-Related Vein Thrombosis in Breast Cancer Patients
Authors: Kang Junren , Sun Wenyan , Li Hailong , Ma Enling , Wang Kai , Chen Wei
Published: September 2015

Purpose

To identify clinical incidence, risk factors and treatment of peripherally inserted central venous catheters (PICCs)-related upper extremity venous thrombosis (UEVT) in breast cancer patients undergoing chemotherapy.

Methods

We performed a retrospective cohort study of breast cancer patients with PICC insertion undergoing chemotherapy. PICC-related UEVT was diagnosed by ultrasound. Patient-, catheter- and insertion-related factors were analyzed in univariable and multivariable logistic regression to identify significant independent risk factors for PICC-related UEVT. The incidence and treatment of PICC-related UEVT were also analyzed.

Results

A total of 568 breast cancer patients with PICC undergoing chemotherapy were included, for a total of 54,769 catheter days; 8 patients (1.4%) developed PICC-related UEVT. The median time of developing UEVT was 11 days (range of 3 to 79 days). In multivariable analysis, metastasis (p = 0.002) and malposition (p = 0.013) were shown to be significant risk factors for PICC-related UEVT. All patients were treated with low-molecular-weight heparin (LMWH) and followed until PICCs were removed. None of the patients developed pulmonary embolus.

Conclusions

Metastasis and malposition were significant risk factors for PICC-related UEVT in breast cancer patients. With early diagnosis and standardized anticoagulant treatment, a better clinical outcome could be achieved. Further prospective and large sample studies are needed.
Hemodialysis Catheter Tip Design: Observations on Fluid Flow and Recirculation
Authors: Vesely Thomas M. , Ravenscroft Adrian
Published: September 2015

Purpose

To observe fluid flow patterns and measure recirculation rates of tunneled hemodialysis catheters using a mechanical model that simulates hemodialysis treatment.

Materials and methods

Nine tunneled hemodialysis catheters were evaluated using a mechanical model that simulated catheter conditions during a routine hemodialysis treatment. Objective and subjective determinants of catheter performance were measured and compared. Catheters were evaluated with blood lines connected in standard and reversed configurations using a fluid flow rate of 425 ml/min.

Results

With blood lines in standard configuration the Split Cath® was the only catheter to exhibit an atypical fluid flow pattern and significant tip movement. When the blood lines were reversed, three split-tip catheters had significant tip movement. The three step-tip catheters and two symmetric tip catheters had stable fluid flow patterns and no significant tip movement with blood lines connected in standard and reverse configurations. The nine catheters had no recirculation when connected in standard configuration. When the blood lines were reversed the percentage of recirculating fluid for symmetric tip, step-tip, and split-tip catheters was 0%, 15% to 20%, and 20% to 30%, respectively. The Equistream®, Palindrome™, and Symetrex catheters had no recirculation with blood lines connected in standard or reversed configurations.

Conclusions

Eight of the nine catheters evaluated in this study performed well with blood lines connected in standard configuration. When blood lines were reversed, symmetric tip and step-tip designs had more stable fluid flow patterns, less tip movement and lower recirculation rates when compared to split-tip designs.
APTIDÃO URBANA AOS INSTRUMENTOS DO ESTATUTO DA CIDADE: PERSPECTIVAS METODOLÓGICAS
Authors: Lobo Mirna Luisa Cortopassi , Muratori Ana Maria
Published: September 2015

A Lei Federal 10.257/01, conhecida como Estatuto da Cidade, cuja função principal é regulamentar os artigos 182 e 183 da Constituição Federal de 1988, instituiu a obrigatoriedade da elaboração de planos diretores para municípios com mais de 20.000 habitantes e municípios com situações específicas como os que integram as regiões metropolitanas ou aqueles de interesse turístico. Simultaneamente, o Estatuto da Cidade legitimou instrumentos criados a partir da década de 1950 em várias cidades brasileiras, quando a questão urbana passou a ser vista como um problema social a ser equacionado no âmbito municipal, direcionado e gerenciado pelos planos diretores, monitorado por novos instrumentos complementares aos pré-existentes. No entanto, a implementação desses instrumentos integrados às leis dos planos diretores municipais, passa pelo gargalo da seleção da maior aptidão de cada setor urbano, ou outra unidade territorial da cidade, para a implantação de cada instrumento ou de um conjunto de instrumentos. Nesse contexto, o presente artigo visa colaborar, discutindo o estabelecimento de indicadores que, relacionados a cada instrumento, possam identificar tais aptidões, através de análises simplificadas das características das cidades. É importante destacar que essa metodologia está voltada principalmente a cidades de porte médio, que se posicionam aquém das metrópoles, quanto a demandas de estudos mais apurados, face às características das variáveis que se sobrepõem em sua estrutura urbana. Outro aspecto importante que vale salientar é que a aplicação dos instrumentos baseados nos indicadores não garante por si só os resultados pretendidos, dependendo de outras variáveis de cunho político e da visão dos atores sociais. São alternativas a serem submetidas ao processo decisório.
ENVIRONMENTAL PERCEPTION OF RURAL COMMUNITIES AND ANALYSIS OF LANDSCAPE: SUBSIDIES FOR PRIORITY AREA FOR CONSERVATION PROPOSITION IN THE RIO GRANDE DO NORTE SEMIARID, BRAZIL
Authors: Lucena Mycarla Araujo , Freire Eliza Maria
Published: September 2015

Priority Areas for Conservation are defined in order to protect environments that are home to a richness of species, endemisms and/or endangered species. However, besides these factors, additional studies such as Environmental Perception of local communities and Landscape Analysis are relevant to assess and minimize the negative effects caused to natural environments. In this context and in this perspective, the Mountain Range Complex João do Vale was studied, located in the state of Rio Grande do Norte, which holds a set of landscapes with different vegetation types that are being replaced by various economic activities resulting from disordered population growth and consequent exploitation of natural resources' potential. The use of these resources, in most cases, occurs improperly, leading to a depletion of this potential. This study proposes to combine Analysis of Landscape, through a Geographic Information System (GIS), to the Environmental Perception of rural communities in order to define Priority Areas for Conservation. Perception data were obtained through direct observation, questioning, interviews and application forms (n = 240); as to the landscape, data from slope maps, Permanent Preservation Areas (PPA) and Environmental Vulnerability were used. The Content Analysis used for perception data showed that respondents have a sense of topophilia regarding where they live, hold a vast knowledge about natural resources and responded positively when asked about the choice of an exclusive area for conservation. These results coupledwith the Analysis of Landscape allowed with of Priorty Areas for Conservation in this Mountain Range Complex with three categories of priority low, medium and high.
ANTROPOGEOMORFOLOGIA DA BACIA HIDROGRÁFICA DO MURUTUCU: ABASTECIMENTO HÍDRICO, USO E OCUPAÇÃO EM BELÉM-PA
Authors: Araújo Júnior Antônio Carlos Ribeiro
Published: September 2015

As Unidades de Proteção Integral estão divididasem Estação Ecológica, Reserva Biológica, Parque Nacional (ou Estadual ou Municipal), Monumento Natural e Refúgio de Vida Silvestre. A Área de Proteção Ambiental de Belém (APA Belém) enquadra-se na categoria Parque Nacional e se deve, sobremaneira, ao fato desta abrigar a fonte de abastecimento de água de toda a Região Metropolitana de Belém (RMB), os lagos Bolonha e Água Preta, além de guardar um ambiente ameno e contemplativo com atrativos turísticos. Apesar de estar inserida na região amazônica, abundante em recursos hídricos, a cidade de Belém e sua região metropolitana, historicamente enfrentam dificuldades de captação, armazenamento e distribuição de água. A antropogeomorfologia considerando as consequências positivas e negativas da ação humana sobre o relevo ajuda a compreender como as formas e processos da Bacia Hidrográfica do Murutucu (BHM) são condicionados para se entender holisticamente quais alterações foram empreendidas nos mananciais do Utinga na BHM tornando mais eficiente o abastecimento hídrico na RMB. As alterações processadas na forma dos lagos mostraram ser necessárias para aumentar seu volume de água e assim atender a demanda crescente da população da RMB denotando que a antropogeomorfologia é um importante instrumento de gestão ambiental.
CARACTERIZAÇÃO E CARTOGRAFIA EM ESCALA DE DETALHE DAS FEIÇÕES FLUVIAIS DERIVADAS DO RIO PEQUENO, ANTONINA-PR
Authors: Silva Julio Manoel França da , Santos Leonardo José Cordeiro
Published: September 2015

O presente artigo aborda a questão da cartografia geomorfológica de detalhe, especificadamente das feições fluviais do rio Pequeno, cuja bacia hidrográfica está inserida na Serra do Mar paranaense, na porção que drena para a baía de Antonina, a nordeste do município homônimo. As etapas de trabalho contaram com interpretação das feições fluviais e uso e cobertura da terra mediante imagens do satélite SPOT-5 (Satellite pour L”Observation de la Terre); estabelecimento de pontos de análise e coleta de amostras (descrição morfológica de campo); análises laboratoriais (granulometria e teor de carbono orgânico); e uso de software de Sistema de Informações Geográficas para elaboração dos mapas representativos dos padrões e da distribuição espacial das feições fluviais. As unidades mapeadas foram: a) feições em calha fluvial – gerados por acreção lateral e constituídos por sedimentos de textura arenosa (barras centrais, barras de pontal, barras de atalho e meandros abandonados), apresentando perfis pedológicos pouco desenvolvidos; e b) feições de planície – gerados por acreção vertical, constituídos predominantemente por sedimentos de textura média  (planície de inundação, terraços fluviais, planície distal, sulcos e lagoas), apresentando desde solos de maturação intermediária a bem desenvolvidos.