bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Secure and Fast Video Encryption Using Minimum Overhead in H.264/AVC Bitstream
Authors: Joshi Jay M. , Dalal Upena D. 
Published: March 2015

Abstract
This paper primarily focuses on the encryption method used to design a selective video encryption scheme to meet following objectives. Encryption and decryption are able to secure in bits-level cryptographic security (after encryption), as well as in the pixel-level visual content security (after decoding for unauthorized user) to meet with sensitive video applications with minimum encryption overhead. It provides perceptual encryption with total scrambling of visual content. Besides, it also makes provision for randomness, not only in spatial but also in the temporal domain. It is presumed that an overall encryption and decryption scheme is quick enough to meet real-time applications. There is no change in the quality of video for genuine users. However, these objectives have been achieved in our proposed algorithm in expense of slight changes in compression bandwidth. The proposed algorithm encrypts residue data and motion vectors after entropy encoding to scramble spatial and temporal resolution. Encryption of motion vectors is based on Expo-Golomb entropy coding in inter-coded macroblock and DC value of residues is encrypted based on context-adaptive variable-length coding (CAVLC) in intra-coded macroblock. In addition, encryption is carried out using an advanced encryption system (AES) in a counter mode stream cipher. The paper deals with security analysis of a proposed scheme in terms of cryptography, as well as perception security.
Inhibition of lethal inflammatory responses through the targeting of membrane‐associated Toll‐like receptor 4 signaling complexes with a Smad6‐derived peptide
Authors: Lee Youn Sook , Park Jin Seok , Jung Su Myung , Kim Sang‐Doo , Kim Jun Hwan , Lee Jae Young , Jung Kyeong Cheon , Mamura Mizuko , Lee Sangho , Kim Seong‐Jin , Bae Yoe‐Sik , Park Seok Hee 
Published: March 2015

AbstractWe have previously reported that Smad6, one of the inhibitory Smads of transforming growth factor‐β (TGF‐β)/bone morphogenetic protein (BMP) signaling, inhibits Toll‐like receptor (TLR) 4 signaling by disrupting the Pellino‐1‐mediated TLR4 signaling complex. Here, we developed Smaducin‐6, a novel membrane‐tethered palmitic acid‐conjugated Smad6‐derived peptide composed of amino acids 422–441 of Smad6. Smaducin‐6 interacted with Pellino‐1, located in the inner membrane, thereby disrupting the formation of IRAK1‐, RIP1‐, IKKε‐mediated TLR4 signaling complexes. Systemic administration of Smaducin‐6 showed a significant therapeutic effect on mouse TLR4‐mediated inflammatory disease models, cecal‐ligation–puncture (CLP)‐induced sepsis, and lipopolysaccharide‐induced endotoxemia, by inhibiting pro‐inflammatory cytokine production and apoptosis while enhancing neutrophil migration and bacterial clearance. Our findings provide clues to develop new peptide‐based drugs to target Pellino‐1 protein in TLR4 signaling pathway for the treatment of sepsis.
Patient reported outcome in posttraumatic pituitary deficiency: results from The Danish National Study on posttraumatic hypopituitarism
Authors: Klose Marianne , Stochholm Kirstine , Janukonyté Jurgita , Christensen Louise Lehman , Cohen Arieh S , Wagner Aase , Laurberg Peter , Christiansen Jens Sandahl , Andersen Marianne , Feldt-Rasmussen Ulla 
Published: March 2015

ObjectivePosttraumatic pituitary hormone deficiency is often suggested. The impact of these predominantly mild and often irreproducible deficiencies on outcome is less clear. The aim of the present study was to describe patient reported outcome in a nationala prioriunselected cohort of patients with traumatic brain injury (TBI) in relation to deficiencies identified upon pituitary assessment.Design and methodsWe conducted a nationwide population-based cohort study. Participants were Danish patients with a head trauma diagnosis recorded in the Danish Board of Health diagnostic code registry; 439 patients (and 124 healthy controls) underwent assessment of anterior pituitary function 2.5 years (median) after TBI. Questionnaires on health-related quality of life (QoL) (SF36, EuroQoL-5D, QoL assessment of GH deficiency in adults) and fatigue (MFI-20) were completed in parallel to pituitary assessment.ResultsPatients with TBI had significant detriments in QoL. Impairment (mainly physical scales) related to pituitary deficiency, although only partially confirmed after adjustment for demographic differences. Hypogonadotropic hypogonadism related to several QoL scores. Increasing impairments were observed with declining total testosterone concentrations (men), but not free testosterone concentrations or any other hormone concentrations. Total testosterone was not independently related to impaired QoL and fatigue, after adjustment for demographics, and treatment with antidiabetics, opioids, antidepressants, and anticonvulsants.ConclusionsOnly a very limited relationship between pituitary hormone deficiencies and QoL/fatigue was demonstrated. Due to the dominating influence of concurrent comorbidities, pituitary deficiencies were not independently related to QoL/fatigue. Causality is still to be shown, and whether substitution therapy could be of additional relevance in selected patients needs to be proven.
Geriatric Assessment-Identified Deficits in Older Cancer Patients With Normal Performance Status
Authors: Jolly Trevor A. , Deal Allison M. , Nyrop Kirsten A. , Williams Grant R. , Pergolotti Mackenzi , Wood William A. , Alston Shani M. , Gordon Brittaney-Belle E. , Dixon Samara A. , Moore Susan G. , Taylor W. Chris , Messino Michael , Muss Hyman B. 
Published: March 2015

Abstract

Background.
We investigated whether a brief geriatric assessment (GA) would identify important patient deficits that could affect treatment tolerance and care outcomes within a sample of older cancer patients rated as functionally normal (80%–100%) on the Karnofsky performance status (KPS) scale.

Methods.
Cancer patients aged ≥65 years were assessed using a brief GA that included both professionally and patient-scored KPS and measures of comorbidity, polypharmacy, cognition, function, nutrition, and psychosocial status. Data were analyzed using descriptive statistics and multivariable logistic regression.

Results.
The sample included 984 patients: mean age was 73 years (range: 65–99 years), 74% were female, and 89% were white. GA was conducted before (23%), during (41%), or after (36%) treatment. Overall, 54% had a breast cancer diagnosis (n = 528), and 46% (n = 456) had cancers at other sites. Moreover, 81% of participants (n = 796) had both professionally and self-rated KPS ≥80, defined as functionally normal, and those patients are the focus of analysis. In this subsample, 550 (69%) had at least 1 GA-identified deficit, 222 (28%) had 1 deficit, 140 (18%) had 2 deficits, and 188 (24%) had ≥3 deficits. Specifically, 43% reported taking ≥9 medications daily, 28% had decreased social activity, 25% had ≥4 comorbidities, 23% had ≥1 impairment in instrumental activities of daily living, 18% had a Timed Up and Go time ≥14 seconds, 18% had ≥5% unintentional weight loss, and 12% had a Mental Health Index score ≤76.

Conclusion.
Within this sample of older cancer patients who were rated as functionally normal by KPS, GA identified important deficits that could affect treatment tolerance and outcomes.
Age-Stratified Risk of Unexpected Uterine Sarcoma Following Surgery for Presumed Benign Leiomyoma
Authors: Brohl Andrew S. , Li Li , Andikyan Vaagn , Običan Sarah G. , Cioffi Angela , Hao Ke , Dudley Joel T. , Ascher-Walsh Charles , Kasarskis Andrew , Maki Robert G. 
Published: March 2015

Abstract

Background.
Estimates of unexpected uterine sarcoma following surgery for presumed benign leiomyoma that use age-stratification are lacking.

Patients and Methods.
A retrospective cohort of 2,075 patients that had undergone myomectomy was evaluated to determine the case incidence of unexpected uterine sarcoma. An aggregate risk estimate was generated using a meta-analysis of similar studies plus our data. Database-derived age distributions of the incidence rates of uterine sarcoma and uterine leiomyoma surgery were used to stratify risk by age.

Results.
Of 2,075 patients in our retrospective cohort, 6 were diagnosed with uterine sarcoma. Our meta-analysis revealed 8 studies from 1980 to 2014. Combined with our study, 18 cases of leiomyosarcoma are reported in 10,120 patients, for an aggregate risk of 1.78 per 1,000 (95% confidence interval [CI]: 1.1–2.8) or 1 in 562. Eight cases of other uterine sarcomas were reported in 6,889 patients, for an aggregate risk of 1.16 per 1,000 (95% CI: 0.5–4.9) or 1 in 861. The summation of these risks gives an overall risk of uterine sarcoma of 2.94 per 1,000 (95% CI: 1.8–4.1) or 1 in 340. After stratification by age, we predict the risk of uterine sarcoma to range from a peak of 10.1 cases per 1,000, or 1 in 98, for patients aged 75–79 years to &lt;1 case per 500 for patients aged &lt;30 years.

Conclusion.
The risk of unexpected uterine sarcoma varies significantly across age groups. Our age-stratified predictive model should be incorporated to more accurately counsel patients and to assist in providing guidelines for the surgical technique for leiomyoma.
Early Diagenesis by Modern Acid Brines in Western Australia and Implications for the History of Sedimentary Modification on Mars
Authors: Bowen Brenda B. , Benison Kathleen C. , Story Stacy 
Published: March 2015

ABSTRACT
Mineralogical and geochemical data collected from multiple sites on Mars suggest that acid saline surface waters and groundwater existed there in the past. The geologic context and sedimentology suggest that these acid saline waters were associated with groundwater-fed ephemeral lakes. Ephemeral acid saline lakes in southern Western Australia (WA) are some of the few known natural systems that have the same combination of extreme acid brine chemistry and lacustrine depositional setting as is observed on Mars. Thus, the WA acid saline environments provide a modern analog for understanding past depositional and diagenetic processes that may have occurred on Mars. Here, we examine surface sediments and sedimentary rocks that have been in contact with acid (pH down to ∼1.5) and saline brines (total dissolved solids up to ∼32%) in southern Western Australia. Through sedimentological, mineralogical, geochemical, and petrographic analyses, we identify the impacts of early diagenesis in and adjacent to eight acid saline lakes and evaluate the processes that have been important in creating these deposits. The combination of extreme chemistry, spatial variability, arid climate, and reworking by winds and floods contributes to make spatially complex depositional products that are a combination of siliciclastics and chemical sediments. Important syndepositional and very early diagenetic processes in these settings include the chemical precipitation of minerals from shallow groundwaters to form displacive crystals and cements, dissolution/partial dissolution of chemical sediments, replacement/partial replacement of some minerals, cracking due to repeated wetting and drying, and the formation of iron-oxide concretions. Minerals observed in these sediments include a variety of chlorides, sulfates, iron oxides, and phyllosilicates, many of which have textures and mineral associations that suggest authigenic formation. These observations are supported by the chemistry of the modern acid brines, which appear to be supersaturated with respect to these minerals. The range of early diagenetic products, compositions, and textures that are apparent in the WA acid saline lake sediments may provide insights into the processes that influenced the sediments on Mars and the timing of sedimentary formation processes on Mars.
Characteristics of Terrestrial Ferric Oxide Concretions and Implications for Mars
Authors: Chan Marjorie A. , Potter Sally L. , Bowen Brenda B. , Parry W.T. , Barge Laura M. , Seiler Winston , Petersen Erich U. , Bowman John R. 
Published: March 2015

ABSTRACT
Concretions are diagenetic products of cementation that establish significant records of groundwater flow through porous sedimentary deposits. Common spheroidal ferric oxide concretions form by diffusive coupled with advective mass transfer and share similar physical characteristics with hematite spherules from Meridiani Planum (Mars “blueberries”), investigated by the Mars Exploration Rover Opportunity. Terrestrial concretions from the Jurassic Navajo Sandstone are not perfect analogs to Mars, particularly in terms of their geochemistry. However, the Navajo Sandstone contains exceptional examples that represent typical concretion characteristics from the geologic record. Both ancient and modern analogs provide information about concretion forming processes and their relationship to porosity and permeability, fluid flow events, subsequent weathering, and surficial reworking.
Concretions on Earth possess variable mineralogies and form in a variety of lithologies in formations of nearly all geologic ages. Despite the prevalence of concretions, many unknowns exist, including their absolute ages and their precise nucleation and growth mechanisms. Some opportunities for future concretion research lie in three approaches: (1) New analytical techniques may show geochemical gradients and important textures reflecting biotic (role of bacteria) or abiotic origins. (2) Concretion modeling can determine important formation mechanisms. Sensitivity tests and simulations for different parameters can help show the magnitude of influence for different input factors. (3) New age-dating methods that remove preservational bias and expand the supply of datable material may yield quantitative limits to the timing of diagenetic events beyond what relative cross-cutting relationships can show.
The discovery of hematite spherules on Mars has driven efforts to better understand both terrestrial examples of ferric oxide concretions and the competing mechanisms that produce spheroidal geometries. The integration of geologic and planetary sciences continues to encourage new findings in the quest to understand the role of water on Mars as well as the tantalizing possibility that extraterrestrial life is associated with mineral records of watery environments.
Using Nanoparticles to Formulate Sag-Resistant Invert Emulsion Drilling Fluids
Authors: Wagle Vikrant , Al-Yami Abdullah S. , AlAbdullatif Ziad 
Published: March 2015

Abstract
Invert-emulsion fluid (IEF) systems formulated without organophilic clay have successfully addressed issues of barite sag while drilling wellbores. In the absence of organoclay, the “organoclay-free” IEFs have to use additional materials like sized calcium carbonate or clay-type materials to bolster the rheological properties and suspension character of the system. In the absence of low-gravity solids (LGS), the loss of suspension, especially in an inclined well, can lead to sag and cause a density gradient along the fluid column that may fracture the formation.
This paper presents a solution toward barite sag in an invert emulsion drilling fluid with the use of novel nanoparticles. The use of nanoparticles was shown to prevent sag in 9 ppg, 12 ppg, and 16 ppg organoclay-free IEF in a static-aging cell held vertical at 90° and then inclined at 45°. Fluids formulated with nanoparticles showed good sag control in different base oils with minimal oil separation. Extended sag testing with the sag-control additive at 250°F for 24 hours and at 150°F for 60 hours gave minimal oil separation and no barite sag. The nanoparticles based IEF was also subjected to contamination testing. Barite sag measurements performed on “contaminated” nanoparticle-based IEF shows that the suspension characteristics remain unaffected and the mud properties are tolerant to the presence of contaminants. Experimental data demonstrating the anti-sag performance of the nanoparticles in IEF is presented and compared to fluids without the nanoparticles.
Percussion Drilling System Combined with Hybrid PDC Bit Increases ROP and Interval Drilled on Taoudenni Basin Well in Mauritania
Authors: Powell Scott , Garcia Alexis , Barocio Hector , Alonso Alvaro 
Published: March 2015

Abstract
Drilling the Taoudenni Basin in Mauritania has posed a costly and time consuming challenge for operators looking to develop the basin economically. The formation's compressive strength limits the bit selection to heavyset PDC bits or hard rock roller cone insert bits due to their abrasive composition. One way to increase the effectiveness and drilling efficiency is to add a percussion force, increasing the axial energy, along with a hybrid PDC bit with PDC cutters and impregnated diamond material on the blades and secondary cutting structures.
The main similarity between fixed cutter hybrid bits and roller cone bits is that both incorporate a similar means of energy transfer when used with a positive displacement motor. Axial weight from a drilling rig is applied while a hydraulic motor turns the bit at different speeds. A proposed improvement to this drilling system would be a new energy distribution system that induces axial oscillations and percussion force while still applying the same weight and torsional energy as previous systems.
The system combines the torsional power of a conventional positive displacement motor with a high frequency axial pulse created by a mechanical action. The torque is still transferred directly to the bit and 100% of the hydraulic flow is utilized by the bit nozzles. The mechanical lifting and falling action creates a rapid variation in weight on bit (WOB), allowing the bit's depth of cut to fluctuate while overcoming different stresses. The percussion force created after each downward stroke, along with weight on bit variations, lead to increased rates of penetration (ROP).
This system has already been utilized on two wells in Mauritania, drilling a variety of formations with PDC, hybrid fixed cutter and roller cone insert bits. This paper will focus on the 8½″ interval, drilling the Atar Group and Jbeliat Teniagouri formations. These formations consist of sandstone, shale interbedded with siltstone, dolerite and pyrite. Confined compressive strengths range from 20 to 30kpsi in top section to 60kpsi in lower intervals where dolerite appears. This new technology increased ROP by more than 52% and interval drilled by over 100% through these intervals.
Integrated 3-D Method for Prediction of Mud-Weight Window for Subsalt Well Sections
Authors: Shen Xinpu , Hu Xiaomin , Zheng Xiuyun , Standifird William 
Published: March 2015

Abstract
Owing to the complex distribution of stress directions around a salt body, accurate prediction of mud-weight window (MWW) for subsalt wells has presented a challenge to the industry for a long time. This paper presents an integrated 3-D method for the prediction of mud-weight window. An example of the application of the proposed method in the VK field in deep-water Gulf of Mexico (GoM) is presented. In this integrated 3-D method and the example, 3-D stress solutions obtained by the finite-element method are used as input data to the 1-D prediction tool. The field-scale model used in the calculation is a cubic block with a TVD depth of 30,000 ft, a width of 25,000 ft, and a length of 25,000 ft. The salt body's thickness along the wellbore trajectory is 20,000 ft, and its width is 18,000 ft. Based on seismic sectional data, an anti-cline structure is constructed accordingly at its bottom surface. A 3-D, porous, elastoplastic, finite-element calculation was performed first with the field-scale model. The numerical results of effective-stress components were provided for the 1-D prediction of MWW along the given wellbore trajectory. The finite-element model simulates the geometry of the salt body in detail. Comparisons have been made between the results obtained with the integrated 3-D method, conventional 1-D method, and the finite-element submodeling method. Solutions obtained with conventional 1-D method have missed the abnormality of stress distribution at the salt base and have smaller values of MWW compared to the other solutions. The solution of MWW obtained with the integrated 3-D method is very close to the one obtained with the finite-element submodeling method, but at only one-tenth of the time cost. The integrated 3-D method proposed here has proven to be the most effective and cost-efficient method for MWW prediction for subsalt wells. This work also presents an example of best practice for using the proposed 3D method to predict MWW.
Drillpipe Influence on Drilling Performance
Authors: Herbig Christian , Oueslati Hatem , Hohl Andreas , Reckmann Hanno , Heinisch Dennis , Pessier Rolf , Silva Nalon , Castilho Carlos Alexandre , Gozzi Danilo Signorini 
Published: March 2015

Abstract
Many drilling operations are longer, more complex and harder to achieve. Combined with strict timelines and the demand for higher rates of penetration (ROP), the entire drilling system is being pushed to its physical (loads, bending moment, etc.) and operational limits (drilled formation, drilling parameters, well path, etc.). Exceeding these limits can induce excessive loads and drilling vibrations that can be harmful for the complete drilling systems, including the drill bit, bottomhole assembly (BHA) and drillpipe. Neglecting the drilling dysfunctions can lead to damage, wear and tool failures that finally result in non-productive time (NPT) and higher costs.
Previously published papers concentrated on BHA and drill bit combinations to deliver optimum drilling performance. In this paper, the authors focus on the drillpipe influence on drilling performance and vibration mitigation. Statistics on the influence of stick-slip and ROP for various drillpipe sizes were created and compared. An extensive database containing drilling data, from the past three years, was used as the data source.
To eliminate the effect of various BHA configurations, data from only one high-end standard rotary steerable system (RSS) BHA, without a mud motor, were analyzed. To ensure formation influence on the drillstring dynamics was reduced, only data from horizontal sections within a specific region in US land were considered within this analysis (same target formation).
In addition, a case study from Brazil provides an example where two drillpipes with different diameters were used, resulting in different dynamic behavior. To confirm and understand these observations numerical time domain simulations were performed, analyzed, visualized and compared to the results from the field. The insights gained from the previously described case study and time domain simulations highlight further opportunities to deliver optimal performance and improve bit, BHA and drillstring integrity.