bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scorpion Sting Envenomation in Children in Southeast Turkey
Authors: Bosnak Mehmet , Ece Aydin , Yolbas Ilyas , Bosnak Vuslat , Kaplan Metin , Gurkan Fuat 
Published: February 2011

Background Scorpion sting envenomation is a life-threatening emergency and a common public health problem in many regions of the world, particularly in children. Children are at greater risk of developing severe cardiac, respiratory, and neurological complications. Objectives The aims of this study were to evaluate demographic, clinical, laboratory, treatment, and outcome characteristics for pediatric patients with scorpion sting envenomation in southeast Turkey and to describe features that may be predictive of the need for pediatric intensive care unit (PICU) care. Methods A total of 52 charts of children (mean age: 7.7 ± 2.8 years; age range: 1.5–15 years) presenting with scorpion sting envenomation to a single hospital in southeastern Turkey were investigated. General characteristics of the children, species of the scorpions, anatomic site of the sting, clinical and laboratory findings, treatment approaches, complications, and outcomes were recorded. Results Twenty-four stings (46.2%) were inflicted by Androctonus crassicauda, 1 (1.9%) by Leiurus quinquestriatus, and the sources of the other stings were not known. Thirty-one patients (59.6%) were admitted from rural areas. Admission from a rural area was a significant risk factor for severe envenomation. Foot-leg was the most frequently stung part of the body (48%). The greatest number of stings occurred in the summer (78.8%). Cold extremities and tachycardia were the most frequently seen clinical findings (38.4% for both). Twenty patients (38.5%) had signs of serious envenomation and required admission to the PICU. Hemoglobin, white blood cell count, activated prothrombin time, aspartate aminotransferase, alanine aminotransferase, and creatine phosphokinase levels were higher in severely envenomed children compared to levels in those with mild-moderate stings. Antivenom was given at a primary or secondary health center before arrival to our hospital in 44 (84.6%) patients, without any apparent difference in the number of patients presenting with mild-moderate and severe envenomed stings. All patients recovered after treatment except for 1 child who died with severe pulmonary edema. Conclusions We found no clinically useful demographic or epidemiological data to guide decision making regarding the need for PICU admission for pediatric victims of scorpion sting in our area. Decisions on transfer and admission to a PICU should be based on the development of systemic findings of envenomation.
Polygraphy of Sleep at Altitudes Between 5300 m and 7500 m During an Expedition to Mt. Everest (MedEx 2006)
Authors: Mees Klaus , de la Chaux Richard 
Published: February 2011

Objectives Sleep at extreme altitudes is characterized by the repetitive occurrence of central apneas that in some cases may lead to a marked decrease in arterial oxygen saturation. During the Ludwig Maximilians University Expedition to Mt. Everest (MedEx 2006), nocturnal polygraphic recordings were made at different altitudes and included the first recordings ever made at 7500 m, which were completed on 8 separate occasions during the expedition. Methods The study was performed on the author (K.M., 58 years, 181 cm, 75 kg), who is an experienced high-altitude mountaineer. The standard polygraphic parameters, such as nasal and oral airflow, thoracic and abdominal effort, oxygen saturation, heart rate, body position, movement, and snoring, were collected with a portable sleep recording device (AlphaScreen, SensorMedics, Germany, Hochberg) at different altitudes between 5300 m and 7500 m, and were compared with baseline assessments made in Munich, Germany (altitude 508 m). The daytime value of oxygen saturation at rest was measured at South Col (8000 m) and at the South Summit (8763 m) without breathing supplemental oxygen for at least 10 minutes. Results The number of apneas and hypopneas of central origin increased up to a maximum of 148/h with a minimal blood oxygen saturation of 48% at 7500 m, compared with <5/h at Munich. After 11 days of acclimatization, data recorded at 5300 m showed a marked reduction of disturbed sleep. The Apnea-Hypopnea-Index dropped from 138/h to 51/h, and the minimal blood oxygen saturation rose from 57% to 67%. At South Col (8000 m), the daytime value of oxygen saturation at rest ranged between 53% and 55%, and on South Summit (8673 m) without breathing supplemental oxygen for at least 10 minutes, it fluctuated around 50%. Conclusions These data correlate well compared with those obtained in hypobaric chamber studies and show that regardless of physiologic adjustment to low oxygen conditions at Base Camp altitude, during the final summit attempt oxygen saturation drops further to 55% and even less. Thus recordings of nocturnal oxygen saturation at Camp 3 (7500 m) on Everest, where the night is spent before the summit attempt, may help to show the actual efficiency of hypoxic ventilatory response and to detect the individual hypoxic tolerance to altitudes above 8000 m.
A Prospective, Multi-Year Analysis of Illness and Injury During Summer Travel to Arid Environments
Authors: Tonna Joseph E. , Lewin Matthew R. , Hahn In-Hei , Platts-Mills Timothy F. , Norell Mark A. 
Published: February 2011

Objective There exist no prospectively generated analyses of the type and frequency of medical incidents in desert settings. We created a database of every illness and injury during 6 field seasons in the Gobi Desert in order to optimize expedition medical and safety planning. Methods Every incident presenting to the expeditions’ physicians, regardless of type, magnitude, treatment, or outcome, was recorded. Incidents ranged from headache, insomnia, and diarrhea to lacerations, infection, fights, psychosis, and foreign body extraction and were thus categorized, segregating urban travel-related complaints from illness and injury occurring in the desert setting. The chronology of incidents and illnesses was observed. The incidence of categorized illness and injury was analyzed using descriptive statistics and was presented in terms of person-days in the field. Results There were 412 incidents recorded during 2689 person-days from 6 field seasons in the Gobi Desert from 2003 through 2007. The expeditions’ physicians saw an average of 2.2 incidents·d−1 in the urban setting compared to 3.6 incidents·d−1 in the desert. Circadian rhythm disturbances, gastrointestinal illnesses, and musculoskeletal complaints predominated in the urban setting, while minor trauma, heat-related exposures, and gastrointestinal and orthopedic problems predominated in the desert setting. Our data show an absolute risk of illness or injury of 153.2 incidents per 1000 person-days and a risk of “gastrointestinal” and “trauma” complaints of 21.2 and 23.1 per 1000 person-days, respectively. Conclusions Herein we describe results from the first ever prospective study of the hazards of travel in an arid environment. We observed that there are patterns of injury and illness that are consistent across expeditions to the Gobi Desert. For example, while heat- and wind-exposure–related illness and injury in the desert are quite common, other aspects of the desert environment are very forgiving. Perhaps the most interesting finding in our cohort was the degree to which different problems occurred at different stages of the expeditions. Our data sets suggest several future studies to evaluate patterns of illness and injury and could be an asset to recreational travelers and religious pilgrims, as well as to those sending employees to extreme environments.
The Effect of Dynamic Intermittent Hypoxic Conditioning on Arterial Oxygen Saturation
Authors: Hetzler Ronald K. , Stickley Christopher D. , Kimura Iris F. , LaBotz Michelle , Nichols Andrew W. , Nakasone Kenneth T. , Sargent Ryan W. , Burgess Lawrence P.A. 
Published: February 2011

Background Increases in arterial oxygen saturation (SaO2) in response to intermittent hypoxic exposure (IHE) are well established. However, IHE protocols have historically involved static hypoxic environments. The effect of a dynamic hypoxic environment on SaO2 is not known. Objective The purpose of this study was to examine the effect of dynamic IHE conditioning on SaO2 using the Cyclical Variable Altitude Conditioning Unit. Methods Thirteen trained participants (9 males, age 30.1 ± 9.2 years; 4 females, age 30.3 ± 8.9 years) residing at or near sea level were exposed to a 7-week IHE conditioning protocol (mean total exposure time = 30.8 hours). Participants were exposed to a constantly varying series of hypobaric pressures simulating altitudes from sea level to 6858 m (22 500 feet) in progressive conditioning tiers, creating a dynamic hypoxic environment. SaO2 was evaluated using pulse oximetry (SpO2) 4 times: at 2740, 3360, and 4570 m, prior to and following the first 3 weeks of IHE, and at 4570, 5490, and 6400 m at the start and end of the final 4 weeks. Results SpO2 improved 3.5%, 3.8%, and 4.1% at 2470, 3360, and 4570 m, respectively ( P < .05), and 3.3%, 3.4%, and 5.9% at 4570, 5490, and 6400 m, respectively ( P < .05). At 4570 m, SpO2 increased from 81.7% ± 6.5% to 89.1% ± 3.2% over the entire 7-week conditioning period. Discussion The dynamic intermittent hypoxic conditioning protocol used in the present study resulted in an acclimation response, such that SpO2 was significantly increased at all altitudes tested, with shorter exposure times than generally reported.
Prevalence of Airway Obstruction in Recreational SCUBA Divers
Authors: Weaver Lindell K. , Churchill Susan K. , Hegewald Matthew J. , Jensen Robert L. , Crapo Robert O. 
Published: February 2011

Objective The prevalence of airflow obstruction in recreational self-contained underwater breathing apparatus (SCUBA) divers is unknown. Since airflow obstruction is a relative contraindication for diving, we conducted a study to determine its prevalence and magnitude in a cohort of recreational divers in Saba, Netherlands Antilles. Methods Prior to diving, divers were asked to complete a diving/health questionnaire and then to perform spirometry administered by trained dive store personnel. Spirometry instrumentation provided immediate feedback regarding test quality. Results Of 8365 eligible divers during the study period (November 1997–March 1999), 668 enrolled and completed questionnaires. Of those completing questionnaires, 46% reported a history of smoking, 13% were current smokers, 15% wheezed, 6% had asthma, 4% used bronchodilators, and 3% took oral steroids. Of 654 completing spirometry, 231 had acceptable spirometry quality and complete questionnaires. By forced expiratory volume in 1 second/forced vital capacity, 10% had mild, 1.7% had moderate, and 0.4% had severe airflow obstruction. Conclusions The prevalence of airflow obstruction was 6% to 15% by report and 12% by spirometry, approximating the combined prevalence of asthma and chronic obstructive pulmonary disease in the general population. Study limitations include possible self-selection and low enrollment rate. Prospective lung function testing can be conducted at remote sites using nonmedical personnel as “testers.” This study could guide future investigations to determine if asthma is a risk factor for decompression illness.
Comparison of Commercially Available Disposable Chemical Hand and Foot Warmers
Authors: Sands William A. , Kimmel Wendy L. , Wurtz Brittany R. , Stone Michael H. , McNeal Jeni R. 
Published: February 2011

Objective Small chemical hand and foot warmers are used by many winter sport athletes and other outdoor enthusiasts. The purpose of this study was to characterize the thermal behaviors of 14 commercially available hand and foot warmers. Methods Both types of warmers were instrumented with a fast-responding thermistor. One of each pair of warmers was placed in a boot or glove. Temperature was recorded in a data logger for a period of hours to more than a day until the heat output of the devices ceased and returned to room temperature. Thermal behaviors were characterized and graphed, including peak temperature, time to peak temperature, and duration of temperature greater than 30°C. Reliability was determined by comparing thermal behavior of 2 hand or foot warmers of the same type and from the same manufacturer. Comparisons were also made between package claims and measured behaviors. Results Measured outcomes were most noteworthy in their variability within and between manufacturers and types of warmers. A strong correlation was found between the masses of the warmers and their duration of heat production. Conclusions Although there is a paucity of research information on these types of warmers, this experiment showed that some of the devices exceeded packaging claims while others fell short; that the thermal behavior over time of the devices was variable; and that there appears to be a simple but strong relationship between the mass of the devices and the duration of their heat production.
Can People with Raynaud's Phenomenon Travel to High Altitude?
Authors: Luks Andrew M. , Grissom Colin K. , Jean Dominique , Swenson Erik R. 
Published: February 2011

Objective To determine whether high altitude travel adversely affects mountain enthusiasts with Raynaud's phenomenon. Methods Volunteers with Raynaud's phenomenon were recruited using announcements disseminated by organizations dedicated to climbing or wilderness travel and Internet discussion boards dedicated to mountain activities to complete an online, anonymous survey. Survey questions addressed demographic variables, aspects of their Raynaud's phenomenon, and features of their mountain activities. Respondents compared experiences with Raynaud's phenomenon between high (>2440 m; 8000 feet) and low elevations and rated agreement with statements concerning their disease and the effects of high altitude. Results One hundred forty-two people, 98% of whom had primary Raynaud's phenomenon, completed the questionnaire. Respondents spent 5 to 7 days per month at elevations above 2440 m and engaged in 5.4 ± 2.0 different activities. Eighty-nine percent of respondents engaged in winter sports and only 22% reported changing their mountain activities because of Raynaud's phenomenon. Respondents reported a variety of tactics to prevent and treat Raynaud's attacks, but only 12% used prophylactic medications. Fifteen percent of respondents reported an episode of frostbite following a Raynaud's phenomenon attack at high altitude. There was considerable heterogeneity in participants’ perceptions of the frequency, duration, and severity of attacks at high altitude compared to their home elevation. Conclusions Motivated individuals with primary Raynaud's phenomenon, employing various prevention and treatment strategies, can engage in different activities, including winter sports, at altitudes above 2440 m. Frostbite may be common in this population at high altitude, and care must be taken to prevent its occurrence.
Stability, Accuracy, and Efficiency of Sequential Methods for Coupled Flow and Geomechanics
Authors: Kim J.. , Tchelepi H.A.. A. , Juanes R.. 
Published: February 2011

Summary
We perform detailed stability and convergence analyses of sequential-implicit solution methods for coupled fluid flow and reservoir geomechanics. We analyze four different sequential-implicit solution strategies, where each subproblem (flow and mechanics) is solved implicitly: two schemes in which the mechanical problem is solved first—namely, the drained and undrained splits—and two schemes in which the flow problem is solved first—namely, the fixed-strain and fixed-stress splits. The von Neumann method is used to obtain the linear-stability criteria of the four sequential schemes, and numerical simulations are used to test the validity and sharpness of these criteria for representative problems. The analysis indicates that the drained and fixed-strain splits, which are commonly used, are conditionally stable and that the stability limits depend only on the strength of coupling between flow and mechanics and are independent of the timestep size. Therefore, the drained and fixed-strain schemes cannot be used when the coupling between flow and mechanics is strong. Moreover, numerical solutions obtained using the drained and fixed-strain sequential schemes suffer from oscillations, even when the stability limit is honored. For problems where the deformation may be plastic (nonlinear) in nature, the drained and fixed-strain sequential schemes become unstable when the system enters the plastic regime. On the other hand, the undrained and fixed-stress sequential schemes are unconditionally stable regardless of the coupling strength, and they do not suffer from oscillations. While both the undrained and fixed-stress schemes are unconditionally stable, for the cases investigated we found that the fixed-stress split converges more rapidly than the undrained split. On the basis of these findings, we strongly recommend the fixed-stress sequential-implicit method for modeling coupled flow and geomechanics in reservoirs.
A Risk-Adjusted Method for Determining OCS Lease Abandonment Liability in the Gulf of Mexico for BOEMRE Supplemental Bonding
Authors: Kaiser Mark J. , Kruse Bernard J. 
Published: February 2011

Summary
In recent years, because of widespread hurricane destruction in the Gulf of Mexico (GOM) and unprecedented losses to the offshore industry, concern has been raised by the federal government that small operators may have difficulty in completing their decommissioning requirements. Hurricane-destroyed infrastructure is significantly more expensive to decommission than normal operations, and small operators are at risk to financial liability and potential bankruptcy. If a company goes bankrupt and there are no capable working-interest owners or previous leaseholders, the financial liability may fall upon the US government. To ensure that the government is adequately protected from incurring costs associated with offshore-lease abandonment, Minerals Management Service (MMS), recently renamed the Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE), requires operators to post a supplemental bond if at least one working-interest owner on a lease does not satisfy a minimum financial capacity. A supplemental-bonding formula was developed by MMS in the early 1990s that is based upon the estimated cost of decommissioning. In recognition of the long period of time since the supplemental-bonding formula was developed, an updated risk-adjusted bonding mechanism is presented in this paper. Our purpose is to update the 1990-legacy formula and present risk-adjusted alternatives to incorporate the uncertainty inherent in the implementation of formula mechanisms. The philosophy of making rational tradeoffs between cost and risks is common throughout the offshore industry, and this paper describes the selection of bonding levels that balance the need of the government to minimize its decommissioning exposure at an acceptable level of risk.
A Novel Application of Closed-Fracture Acidizing
Authors: Pournik M.. , Mahmoud M.. , Nasr-El-Din H.A.. A. 
Published: February 2011

Summary
The success of acid fracturing depends on the conductivity created and retained under closure stress in addition to the length of conductive fracture. The majority of acid-fracturing treatments show a sharp decline in conductivity with increasing closure stress, with almost no significant conductivity after a short production time. As a result, many wells are refractured to restore them to the original productivity after the initial fracture. However, the success of these refracture treatments has been diverse with respect to extent of stimulation.
A new approach to overcome productivity decline of acid-fractured wells is to perform closed-fracture acidizing (CFA) at the appropriate time in the life of the well to keep fractures conductive. An experimental study was conducted to investigate the effect of CFA on already-acid-fractured cores exposed to a certain level of closure stress. Indiana limestone cores were acidized with a typical acid system of 15 wt% hydrochloric acid (HCl) viscosified with a polymer under typical field conditions. After the first acidizing process, conductivity measurements were conducted on acid-etched core faces up to a certain closure stress. While the fracture was kept under the closure stress, a CFA treatment was conducted under the same conditions as the initial acidizing. The re-etched fractures were once again placed under different levels of closure stress, and conductivity measurements were taken at each stress. Experiments were conducted under different conditions of leakoff, polymer concentration, and closure stress after the first acidizing in order to determine the influence of these parameters on the refracturing conductivity.
In all cases, CFA enhanced fracture-face etching, while it significantly increased fracture conductivity under closure stress. However, leakoff, polymer concentration, and closure stress did influence the degree of success of CFA. Leakoff allowance and lower polymer concentration resulted in the most enhanced fracture conductivity in comparison to the initial acid-fracturing process.
Integrating Learning Curves in Probabilistic Well-Construction Estimates
Authors: Jablonowski C.. , Ettehad A.. , Ogunyomi B.. , Srour I.. 
Published: February 2011

Summary
For multiple-well drilling and completion campaigns, cost and schedule performance tend to improve over time. This trend in improvement is commonly referred to as a "learning curve." When a learning curve is anticipated, the campaign cost and schedule estimates may be reduced dramatically relative to an assumption of constant performance. That is, ignoring the learning curve will lead to overly pessimistic estimates. While learning curves can be observed in campaigns of various lengths and complexity, they are typically most important in large campaigns where the majority of wells are drilled after a significant portion of the learning has occurred. Conversely, they may not be appropriate in short campaigns where there is a limited time to implement learnings, or in campaigns with highly idiosyncratic wells where learning does not necessarily translate across projects.
Many operators consider the use of learning curves a best practice and provide procedures for estimation and implementation in their cost-estimating guidelines. In cases where comparison projects exist, estimating a learning curve for a prospective project can be achieved with some certainty. This form of deterministic learning is a well-established topic in the drilling-engineering literature and in practice. However, in cases where the sample of comparison projects is small, there may be significant uncertainty in the rate and magnitude of learning over time, and some form of probabilistic learning is more appropriate. This form of learning is not well established in the literature or in practice.
This paper investigates methods for systematic integration of learning curves in probabilistic estimates. Brief reviews of probabilistic estimating methods and learning curves are provided. A general method and specific procedures for integrating learning curves in probabilistic estimates are then provided. For each method, the key assumptions are itemized and discussed and a demonstration is provided. While no single procedure will fit every situation, it is concluded that the general method is straightforward, transparent, and can be implemented using off-the-shelf spreadsheet software. The proposed procedures generate results that provide engineers and decision makers with a refined representation of uncertainty and can improve capital-investment valuation and decision making.