bluuebunny/crossref_metadata_2025 huggingface dataset:
An Exact Method for the Capacitated Location-Routing Problem
Authors: Baldacci Roberto , Mingozzi Aristide , Wolfler Calvo Roberto
Published: November 2011

The capacitated location-routing problem (LRP) consists of opening one or more depots on a given set of a-priori defined depot locations, and designing, for each opened depot, a number of routes in order to supply the demands of a given set of customers. With each depot are associated a fixed cost for opening it and a capacity that limits the quantity that can be delivered to the customers. The objective is to minimize the sum of the fixed costs for opening the depots and the costs of the routes operated from the depots.

This paper describes a new exact method for solving the LRP based on a set-partitioning-like formulation of the problem. The lower bounds produced by different bounding procedures, based on dynamic programming and dual ascent methods, are used by an algorithm that decomposes the LRP into a limited set of multicapacitated depot vehicle-routing problems (MCDVRPs).

Computational results on benchmark instances from the literature show that the proposed method outperforms the current best-known exact methods, both for the quality of the lower bounds achieved and the number and the dimensions of the instances solved to optimality.
On 3-adic Valuations of Generalized Harmonic Numbers
Authors: Kamano Ken
Published: November 2011

We investigate 3-adic valuations of generalized harmonic numbers
Phenotypic Plasticity of Chinese Sprangletop (Leptochloa chinensis) in Competition with Seeded Rice
Authors: Chauhan Bhagirath S. , Johnson David E.
Published: November 2011

Chinese sprangletop, a C4species, is one of the most important grass weeds of seeded rice in Asia. Chinese sprangletop biology was studied by growing it alone and in competition with 4 and 12 rice plants. Rice competition did not affect the height of Chinese sprangletop, and the weed grew taller than rice, regardless of the competition. Compared with Chinese sprangletop grown alone, competition from rice reduced Chinese sprangletop leaf number, leaf production rate, tiller number, tiller production rate, leaf area, shoot biomass, relative growth rate, and net assimilation rate. Leaf area and shoot biomass of Chinese sprangletop when grown in competition with 12 rice plants was only 16% and 13%, respectively, of the leaf area and biomass of the weed grown alone.
Herbicide Programs for Enhanced Glyphosate-Resistant and Glufosinate-Resistant Cotton (Gossypium hirsutum)
Authors: Riar Dilpreet S. , Norsworthy Jason K. , Griffith Griff M.
Published: November 2011

Research was conducted at experimental research stations near Keiser and Marianna (Marianna-A), AR, in 2007, and in a grower's field near Marianna (Marianna-B), AR, in 2008, to compare herbicide programs, including POST application(s) of glyphosate/glufosinate alone or in combination with residual herbicides applied as PRE, mid-POST (MPOST), or layby POST-directed (PD) in enhanced glyphosate- and glufosinate-resistant cotton. Weed species evaluated included Palmer amaranth, pitted morningglory, hemp sesbania, barnyardgrass, and a mixture of large crabgrass and goosegrass. At Marianna-B, AR, the Palmer amaranth population was a mixture of glyphosate-resistant and -susceptible plants. For both cotton cultivars and at all locations, inclusion ofS-metolachlor plus fluometuron PRE increased weed control and/or decreased the number of glufosinate or glyphosate applications needed in-season. At Marianna-B, AR, PRE residual herbicides and/or glufosinate were required to control glyphosate-resistant Palmer amaranth. Addition of pyrithiobac to glufosinate or glyphosate did not increase weed control. A layby PD application of flumioxazin plus MSMA was required to increase late-season control of all weed species in POST glufosinate-only programs, but not in POST glyphosate-only programs. None of the programs caused > 5% injury to either cotton cultivar. Seed-cotton yield was similar in all herbicide programs at Keiser, AR, and Marianna-A, AR, except for the POST glyphosate-only program, which yielded less than the PRE followed by POST programs in glyphosate-resistant cotton at Keiser, AR. In general, PRE herbicides did not increase cotton yield but did improve early and late-season control of glyphosate-susceptible and -resistant weeds in both cotton cultivars.
Vegetative Reproduction Potential of Common Purslane (Portulaca oleracea)
Authors: Proctor Christopher A. , Gaussoin Roch E. , Reicher Zachary J.
Published: November 2011

Common purslane is a widely distributed summer annual weed. It can reproduce vegetatively from stem cuttings by forming adventitious roots from the cut end of the stem. Apart from large stem cuttings, it is unclear whether purslane cuttings of various plant tissues differ in their ability to reproduce asexually. The objective of the study was to determine the survival and asexual reproductive capacity of purslane cuttings. A greenhouse study evaluated three cuttings from two stem locations and a leaf from one stem location for their survival and new leaf growth after 21 d. Cuttings included a stem node with either leaves attached or removed and a stem internode, all from proximal and distal stem locations relative to the root crown, and a leaf from a proximal stem node. Stem node cuttings had ≥ 70% survival, whereas internodes had 0% survival. Nodes with leaves attached further increased survival by > 20%. The location of the cutting on the main stem did not affect survival. Only noded cuttings produced new leaves, and cuttings with leaves attached produced the most new leaves. For purslane to vegetatively reproduce, nodes on stem cuttings are required, and the presence of leaves on the cutting improves the survival and new leaf growth of cuttings. Therefore, mechanical methods of weed control that chop and spread purslane leaves and stems might not be effective and could ultimately increase weed populations.
Herbicide Choice and Timing for Weed Control in Imidazolinone-Resistant Lentil
Authors: Fedoruk L. K. , Shirtliffe S. J.
Published: November 2011

Conventional lentil, because it is relatively noncompetitive, requires effective weed control. In conventional lentil, metribuzin should be applied by the four-node stage to avoid crop injury. This is earlier than the critical period of weed control (CPWC) of lentil, which is between the five- and 10-node stage. However, imidazolinone herbicides potentially can be applied later in imidazolinone-resistant lentil, which might allow lentil to be kept weed-free for the CPWC. The objective of this experiment was to determine the best herbicide choice and application timing necessary to achieve the CPWC in lentil. To do this we tested herbicides differing in efficacy and residual control. The herbicides imazethapyr/imazamox, imazamox, and metribuzin + sethoxydim were applied at the two- and six-node lentil stage. Of the three herbicide treatments, metribuzin + sethoxydim resulted in grain yield that was on average 31% lower than the other herbicides. This occurred because of greater broadleaf biomass (composed primarily of wild mustard) in lentils treated with these herbicides regardless of application timing. Because of this, the CPWC was not attained with metribuzin + sethoxydim. Late applications of imazethapyr/imazamox or imazamox resulted in grain yields 30% higher than with early application of these herbicides. Early applications of the imidazolinone herbicides gave poor control of grass weeds (wild oat and green foxtail), but late applications resulted in grass weed control equivalent to metribuzin + sethoxydim. Imazethapyr/imazamox or imazamox should be applied at the five- to six-node stage of lentil to achieve the CPWC.
Gestational Age/Developmental Guidelines Tool
Authors: Jo Kirschbaum Mary
Published: November 2011

NURSING STAFF IN LEVEL II nurseries within the Fairview Healthcare System wanted to learn how to request appropriate consultations for occupational and/or speech therapy with young infants. The Gestational Age/Developmental Guidelines handout presented in this column was a collaborative effort of both occupational and speech therapies. The checklist capitalizes on published literature and on the clinicians’ specialized knowledge.
News of The Academy of Neonatal Nursing
Authors: Davis Deborah Winders
Published: November 2011

Beginning with this issue, I am the new editor for the “News of The Academy of Neonatal Nursing.” Before introducing myself, let me first say thank you to Chuck Rait for his leadership and unending commitment to The Academy and to neonatal nursing. Chuck has been wearing many hats since launching this new association. In order to focus on other issues, Chuck is turning this column editorship over to me.
Patient-Triggered Ventilation: How Does the Trigger Work?
Authors: Thomas Patricia
Published: November 2011

FOR THE VAST MAJORITY OF neonates requiring ventilation in our NICUs today, we use what is called patient-triggered ventilation (PTV)—synchronized intermittent mandatory ventilation, assist/control ventilation, or pressure support ventilation (Table 1). Also called synchronized ventilation, PTV has long been used successfully in adults. The goal of PTV is to prevent asynchronous breathing against the ventilator, which has been shown to contribute to pneumothorax in the neonate and subsequently to an increased risk of intraventricular hemorrhage in preterm infants.1,2Other short-term benefits of PTV include improvements in oxygenation and carbon dioxide elimination, reduced variability in cerebral blood flow, and a shorter duration of mechanical ventilation.3
The Early Feeding Skills Assessment for Preterm Infants
Authors: Thoyre Suzanne , Shaker Catherine , Pridham Karen
Published: November 2011

Preterm infants develop the skills necessary to begin oral feeding as their health stabilizes and as they reach a postconceptional age that supports coordination of breathing and swallowing with oral-motor functioning. The time from initiation of oral feeding to full oral feedings (with adequate intake for growth and maintenance of physiologic stability) can vary from days to months for the preterm infant. The approach to feeding the infant during this transition period must be developmentally supportive and tailored to meet the needs of the individual. To accomplish this, caregivers—notably nurses and parents—need to communicate about the specific skills that the infant has gained, about skills that are emerging, and about skills that the infant has not yet developed. The Early Feeding Skills (EFS) Assessment is a checklist for assessing infant readiness for and tolerance of feeding and for profiling the infant’s developmental stage regarding specific feeding skills: the abilities to remain engaged in feeding, organize oral-motor functioning, coordinate swallowing with breathing, and maintain physiologic stability. This article introduces the EFS.
Medium-Chain Acyl-CoA Dehydrogenase Deficiency: A Case Presentation
Authors: Moore Darlene
Published: November 2011

When an infant presents with hypoglycemia, acidosis, hepatomegaly, and respiratory arrest, the neonatal team must be alert to the possibility of a metabolic disorder. Among those to be considered is medium-chain acyl-CoA dehydrogenase deficiency, which occurs in 1 in 10,000–23,000 live births. Recognizing and treating this disorder early could decrease the morbidity and mortality associated with the diagnosis.
Mark
Authors: Drew Debra
Published: November 2011

AFTER MY USUAL COMMUTE, I ARRIVE in the NICU without much conscious thought. Having made this 30-minute commute for 17 years, I feel a bit like an automaton going through thoughtless motions; yet the repetition can be a time to prepare myself for the day.
Implementation of an Enteral Nutrition and Medication Administration System Utilizing Oral Syringes in the NICU
Authors: Copelan David , Appel Julie
Published: November 2011

NICU patients are at particularly high risk of harm and even death from medical error. In one NICU, a process change was undertaken to minimize the risk of errors resulting in the intravenous (IV) administration of enteral formulas and oral medications. In addition, a double-check system for medication doses was introduced to reduce the likelihood of medication errors. The previous practice was to deliver enteral formulas via syringe pump using IV syringes and tubing and to dispense medications in bulk bottles, drawing up patient-specific doses at the bedside. Converting to oral syringe delivery of medications and enteral formulas utilizing enteral-only tubing eliminated the necessity for Luer-Lok IV tubing and syringes, thereby reducing the potential for wrong-route error. Converting from dispensing medications in bulk to a unit-dose system permitted establishment of a double- check system in which doses are first checked by a pharmacist and then checked by the nurse before they are administered. This article describes the planning, implementation, and postimplementation process required to make this change in practice a success.
Using Developmental Assessments in the NICU to Empower Families
Authors: Lowman Linda , Stone Linda , Cole Jean Gardner
Published: November 2011

NICU nurses and developmental specialists have a unique opportunity to facilitate the beginning of a meaningful parent/infant relationship in the NICU setting. The Brazelton Neonatal Behavioral Assessment Scale (BNBAS) is one tool that can be utilized to support this process. When parents observe this assessment, they learn to recognize and understand infant cues and gain confidence for everyday routines such as diapering, feeding, general caregiving, and even taking that first trip with the baby to the grocery store. Parents become empowered when they discover not only their baby’s amazing competencies, but also their own. In addition, the BNBAS provides a framework through which parents can effectively communicate and advocate for their baby.
Life’s Lessons
Authors: Anonymous
Published: November 2011

SOMETIMES I WAKE UP IN THE MORNING and don’t remember I have a cancerous tumor in my eye until the second or third cup of coffee. But then again I remember there are a lot of nurses who have cancer and life experiences with possible outcomes much different than mine. Life often deals us lessons that remind us of who and what we are all about. My experience with cancer has been a reminder of what is important in life. It has been a reminder of my purpose in becoming a nurse and being a nurse for over 31 years.
Subdural and Primary Subarachnoid Hemorrhages: A Case Study
Authors: Barker Stacie
Published: November 2011

Subdural hemorrhage (SDH) and primary subarachnoid hemorrhage (SAH) are two forms of intracranial bleeding that can be encountered in infants. These events can be life threatening to the infant and devastating to his family. Neonatal nurses need to have an understanding of these unfortunate, yet not uncommon, types of intracranial hemorrhage. This article explains the etiology, the diagnosis, and the treatment of SDH and SAH, concluding with a case study.
Upping the Ante Again: Clinical Topics and the EBP Process
Authors: Trotter Carol
Published: November 2011

IF THE TITLE OF THIS EDITORIAL LOOKS FAMILIAR, THAT IS because it is the same title as the editorial in the May/June 2007 issue of Neonatal Network.® We would like to expand on the topic of Evidence-Based Practice (EBP) and how that might be reflected in the articles that we seek to publish in Neonatal Network:® The Journal of Neonatal Nursing.
Neonatal Subgaleal Hemorrhage
Authors: Reid Julie
Published: November 2011

Subgaleal hemorrhages, although infrequent in the past, are becoming more common with the increased use of vacuum extraction. Bleeding into the large subgaleal space can quickly lead to hypovolemic shock, which can be fatal. Understanding of anatomy, pathophysiology, risk factors, differential diagnosis, and management will assist in early recognition and care of the infant with a subgaleal hemorrhage.
Keeping the Wisdom at Work
Authors: Simons Sherri Lee
Published: November 2011

THE CURRENT SHORTAGE OF nurses is no secret to those who work in or manage neonatal intensive care units. The Health Resources and Service Administration projected that the vacancy rate among nursing positions will increase to 20 percent by 2015.1 Specialty care nurses are even harder to find.2,3 In one survey, 57 percent of hospitals reported that specialty unit positions are the hardest to fill and tend to have the highest vacancy rate.3 A dangerous worker shortage, more severe than many expect, is compounded by deep systems problems in the way most health care organizations operate today.4
Kangaroo Care and Breastfeeding of Mother–Preterm Infant Dyads 0–18 Months: A Randomized, Controlled Trial
Authors: Hake-Brooks Sara , Anderson Gene Cranston
Published: November 2011

Purpose:To determine the effects of kangaroo care (KC) (skin-to-skin contact) on breastfeeding status in mother–preterm infant dyads from postpartum through 18 months.

Design:Randomized, controlled trial. The control group received standard nursery care; in the intervention group, unlimited KC was encouraged.

Sample:A subsample of 66 mothers and their preterm infants (32–36 completed weeks gestation, 1,300–3,000 g, 5 minute Apgar ≥6) who intended to breastfeed.

Main Outcome Variables:Breastfeeding status at hospital discharge and at 1.5, 3, 6, 12, and 18 months as measured by the Index of Breastfeeding Status.

Results:KC dyads, compared to control dyads, breastfed significantly longer (5.08 months vs 2.05 months),p= .003. KC dyads also breastfed more exclusively at each measurement,p= .047. More KC dyads than control dyads breastfed at full exclusivity (100 percent breast milk, index of breastfeeding status levels 1 or 2) at discharge and at 1.5, 3, and 6 months. Mean KC contact per day was 4.47 hours.
A Model Program: Neonatal Nurse Practitioners Providing Community Health Care for High-Risk Infants
Authors: Vasquez Elias Provencio , Pitts Kathleen , Mejia Nilson Enrique
Published: November 2011

Perinatal drug exposure costs our communities millions of dollars each year in hospital fees and in services such as foster care, child protection, and drug treatment. Infants and their families in this group require substantial long- term health care and community resources. Neonatal health care providers should take an active role in developing and implementing home visitation programs to support early hospital discharge and continuity of care for these high- risk infants and their families. Neonatal nurse practitioners should prepare in the future to practice not only in secondary- and tertiary-level neonatal centers, but also in follow-up clinics, long-term developmental centers, and the community. This article describes a home intervention program delivered by neonatal nurse practitioners for high-risk infants and their mothers. The target population is infants exposed prenatally to drugs and/or alcohol.
Sacrococcygeal Teratoma in the Newborn: A Case Study of Prenatal Management and Clinical Intervention
Authors: Fadler Kara , Askin Debbie Fraser
Published: November 2011

Sacrococcygeal teratomas (SCTs) are the most common germinal cell neoplasms of the fetus and neonate. They originate during embryonic development when the primitive streak fails to differentiate among mesodermal, ectodermal, and endodermal tissues in the embryonic disc. This article discusses the fetal pathophysiology of SCTs and the impact of the condition on the newborn. Fetal SCTs can have life-threatening physiologic effects— such as premature labor, dystocia, and high-output cardiac failure—if not managed appropriately. Clinical manifestations, prenatal diagnosis, therapeutic approaches and treatment options for the fetus and newborn, and current research related to SCTs are addressed to aid practitioners caring for a fetus or infant diagnosed with an SCT.
Certification and Core Review for Neonatal Intensive Care Nursing (3rd edition)
Authors: Watson Robin
Published: November 2011

Certification and Core Review for Neonatal Intensive Care Nursing (3rd edition) is the companion to the Core Curriculum for Neonatal Intensive Care Nursing (3rd edition) and is a collaborative effort of AWHONN, NANN, and AACN. The editor (since the original work) has assembled a large group of practicing nurses from the three contributing organizations for this version. This text’s stated intent is to serve as a review tool or study guide for staff seeking certification in neonatal intensive care nursing. Its content is based upon the blueprints for the AACN Certification Corporation’s Neonatal CCRN exam and the National Certification Corporation’s Neonatal Intensive Care Nursing exam. Both of these outlines were used to guide identification of the subject matter discussed and the distribution of items in each content area. The content is divided into five sections.
Ganciclovir: Antiviral Therapy for Congenital Cytomegalovirus
Authors: Bell Susan Givens
Published: November 2011

CYTOMEGALOVIRUS (CMV), a member of the herpesvirus family, is the most common virus passed from the mother to the fetus. According to the Centers for Disease Control and Prevention (CDC), approximately 1 in 150 children is born with congenital CMV infection.1 Neonates may also acquire CMV during delivery, via blood transfusions, or through breast milk. Both prenatally and perinatally infected infants are at risk for developing short-term effects and long-term sequelae and are candidates for antiviral therapy.2 Each year, approximately 8,000 children suffer permanent disabilities secondary to CMV infection.1
The Dying Neonate: Family-Centered End-of-Life Care
Authors: Lisle-Porter Martine De , Podruchny Ann Marie
Published: November 2011

There is a need in the NICU for an end-of-life care guideline that nurses can follow when working with dying infants and their families. Maintaining intravenous access to relieve the infant’s pain, communicating sensitively to the family, and creating precious, everlasting memories are goals that should be part of every dying infant’s care. The nurse’s ability to partner with the family in caring for the infant is integral to helping the family take the first steps in their grief journey. Evidence-based literature provides NICU nurses with the knowledge that they are the facilitators of end-of-life care for dying infants. New mothers and fathers are not aware of the caring parental tasks they can perform for their dying baby. They look to and depend on their infant’s nurses to encourage them. The guideline included here provides nurses with a tool for ensuring that families have the opportunity to create memories that will not only help them with their immediate pain, but also comfort them for a lifetime.
Linezolid
Authors: Bell Susan Givens
Published: November 2011

THE MOST RECENT DATA FROM THE National Institute of Child Health and Human Development Neonatal Research Network revealed that in late-onset sepsis events in very low birth weight neonates proven by blood culture, 70 percent were caused by Gram-positive organisms. Coagulase-negative staphylococci accounted for 68 percent of these Gram-positive infections, and Staphylococcus aureus, Enterococcus species, and Group B Streptococcus were isolated in the remainder.1Staphylococcus epidermidis continues to be the most common coagulase-negative Staphylococcus species isolated in culture, and S. capitis, S. warneri, S. haemolyticus and S. hominis have also been implicated in neonatal infection.
Editorial: On Being a Professional
Authors: Fraser Deb
Published: November 2011

Over the past couple of months I have had the privilege of attending the national meetings of three different professional nursing organizations including the ANN meeting held this year in Phoenix. I was impressed to say the least. Despite changes in the global economy and, more particularly in hospital funding models, nurses took time from their busy work and personal schedules to attend these meetings. In fact over 800 nurses filled the ballrooms and exhibit halls in Phoenix. These nurses took time to carefully listen to speakers, often lining up at the end of a session to ask more questions, and spent hours reviewing the poster presentations and speaking with the authors. They roamed the exhibit hall looking at all the products that promised to help them provide better patient care and gathered at the breakfast round tables to converse with colleagues and share ideas.
You Are the Next Witness: Deposition Tips for the Nurse in the Hot Seat
Authors: Smalls Harriett Twiggs
Published: November 2011

YOU’VE JUST RECEIVED A SUBPOENA and a notice that you are to be deposed. The notice informs you of the time and place of the deposition. The subpoena is, in effect, an order of the court requiring you to be present. It may also require you to bring certain documents with you. As bad as that may sound, if you are prepared, it does not have to be your worst nightmare. Knowing what to expect and doing your homework will help you feel more confident and less anxious.
Ambiguous Genitalia: A Case Study Involving a 24-Week-Gestation Twin B
Authors: Snyder Robin
Published: November 2011

When recognized in the extremely premature infant in the delivery room, ambiguous genitalia is a devastating diagnosis. It can be even more so, if the diagnosis is made several weeks later. The case study reported here illustrates this point. A 24-week Twin B infant born with multiple congenital anomalies was originally thought to be a male. After two weeks, assessment by an astute bedside nurse revealed that the infant’s genitalia were not consistent with those of other 24-week males. A complete workup followed. Twin B was indeed a female with ambiguous genitalia and a high cloacal anomaly. Faced with the uncertainty of ambiguous genitalia, many parents feel emptiness, grief, and guilt. This article differentiates among the various intersex disorders and their treatments, and discusses physical findings, embryologic development, incidence, and treatment plans for male pseudohermaphroditism, true hermaphroditism, gonadal dysgenesis, and female pseudohermaphroditism. Current management strategies are contrasted with protocols of the 1950s to show changes over time.
Nonimmune Hydrops Fetalis Part I: Etiology and Pathophysiology
Authors: Randenberg Andrea
Published: November 2011

Nonimmune hydrops fetalis (NIHF) is a condition in which excess fluid has accumulated in the fetal interstitial spaces as a result of one or more nonimmune factors. A plethora of maternal, placental, and fetal disease processes have been associated with NIHF. Knowledge of the various etiologies of NIHF and how the disease process affects fluid homeostasis is important for planning patient care and counseling families of patients diagnosed with nonimmune hydrops fetalis. This article discusses the mechanisms governing fluid distribution in the extracellular spaces, examines the various etiologies associated with NIHF, and describes the pathogenesis of NIHF for each etiologic category.Part II of this article will appear as the Evidence-Based Practice column in the November/December 2010 issue ofNeonatal Network®.
NonimmuneHydrops FetalisPart II: Does Etiology Influence Mortality?
Authors: Randenberg Andrea
Published: November 2011

HYDROPS FETALIS IS A CONDITION in which there is an excess of total body fluid, primarily within the fetal interstitial spaces.1,2Etymologically,hydrops fetalisis a Latin term meaning “edema of the fetus.”2,3In addition to generalized edema, the fetus has at least one of the following: ascites, pericardial effusion, pleural effusion(s), and an abnormally thick (>6 cm) placenta.4–6Hydrops is classified as nonimmune hydrops fetalis (NIHF) when it occurs without evidence of isoimmunization.7,8
Thomas Hill: A Courageous Premie and His Loving Family
Authors: Discenza Deb
Published: November 2011

I HAVE SPOKEN OVER THE YEARS WITH many families who have described medical professionals giving dire predictions for their NICU baby and preparing them for the worst. An informed opinion is important for families, but the reality is that NICU medicine has many daily miracles that go beyond science and beyond rational thought.
Developmental Considerations in Working with Newborn Infants of Mothers with Diabetes
Authors: Quist Miller Margaret , Morris Lizbeth Ann
Published: November 2011

Infants of diabetic mothers (IDMs) are at risk for an altered developmental course beginning with physiologic alterations in utero. This article describes physiologic and behavioral factors that impact the fetus and newborn infant and may have long-term developmental consequences. A clinical reasoning process to support development optimizes the outcomes of IDMs while in the NICU. Specific interventions are suggested.
Gram-Negative Neonatal Osteomyelitis: Two Case Reports
Authors: Zhang Jinping , Lee Ben H. , Chen Chao
Published: November 2011

Neonatal osteomyelitis is a rare and challenging diagnosis, particularly in the early onset period. Neonatal osteomyelitis is predominantly caused byStaphylococcus aureuswith single bone involvement. Here, we report two cases of neonatal osteomyelitis in premature infants caused byKlebsiella pneumoniaewith multiple bone lesions. Both cases presented with sepsis and meningitis and were initially diagnosed by incidental findings on plain films, with follow-up bone scan imaging. In both cases, diagnosis was timely and treatment was successful. These cases highlight the need to include neonatal osteomyelitis in the differential diagnosis when late-onset or prolonged neonatal sepsis is present, particularly because long-term outcome is dependent on rapid diagnosis and initiation of treatment.
The Case for and Against Using Ball-Drop Multi-Stage Fracturing Systems in Unconventional Horizontal Wells
Authors: Lehman Lyle V. , Shah Koras
Published: November 2011

The use of multi-stage stimulation tools to accelerate the process of stimulating horizontal wells has grown at a tremendous rate. In fact, the usage of these systems is currently underwritten by stimulation service companies because time constraints are minimized on 20-plus-stage treatments. However, using these tools can come with a cost.

This paper will examine the cost benefit of using these tools in unconventional matrix and naturally fractured-based gas and oil completions. The authors will present data that will help readers choose a system to meet their needs based on their particular case. Impact on production rate and ultimate recovery, frac fluid imbibition, reduced service costs, risk in running these systems in horizontal wells and other factors will be explored.
Influence of Thermo-Elastic Stress on Fracturing a Horizontal Injector During Geological CO2 Storage
Authors: Luo Zhiyuan , Bryant Steven L.
Published: November 2011

Horizontal injection wells could be widely used in geological storage projects to provide large injectivities into formations with less favorable permeability-thickness products. Injection induced fracturing, which plays an important role in injection and storage risk assessment, is much more complex for horizontal well than vertical well,. The temperature variation of formation around wellbore due to cool CO2 injection introduces thermo-elastic stress which dramatically decrease critical fracture pressure under some strategies. According to the definition of thermo-elastic stress, the temperature profile of CO2 in horizontal wellbore essentially determines its magnitude.

A model is developed to describe heat transfer between wellbore fluid and surrounding formations by extending our previous heat transfer model of vertical wellbore. In the model, CO2 flux along horizontal wellbore is divided to uniform and non-uniform flux. Mass flow rate of the former case is linear; in the latter case, mass flow rate depends is non-linear and depends of the pressure drop along the wellbore, which is related to friction loss.

The model analyzes factors that affect temperature difference between wellbore CO2 and formation by several dimensionless groups: (1) dimensionless ratio of the rate of heat transfer to the rate of advective transport of enthalpy in vertical wellbore; (2) the length ratio of horizontal well over vertical well; (3) dimensionless friction factor. With new criterion by considering the influence of thermo-elastic stress, we optimize perforation zone of horizontal wellbore to prevent fracturing. Additionally, the influence of formation properties wellbore pressure is discussed to estimate safe perforation zone of horizontal wellbore.
Interplay of Capillarity, Drainage Height, and Aqueous Phase Saturation on Mass Transfer Rate of Solvent Vapor into Heavy Oil
Authors: Ahmadloo F. , Asghari K. , Henni A. , Freitag N. P.
Published: November 2011

Performance of the vapor extraction process is strongly dependent on the efficiency of the mass transfer rate between the solvent and heavy oil or bitumen. Therefore, realistic approximation of diffusion and convective dispersion occurring on the edge of the vapor chamber is required for reliable prediction of production rates in this process. Studies conducted at extremely high permeabilities (>200 D) have reported up to four orders of magnitude increase in the solvent diffusion/dispersion rates between the solvent and heavy oil, such increases could result in unrealistic overestimation of the performance of this process at real reservoir conditions. To address this shortcoming, a comprehensive experimental study was designed and conducted to systematically investigate the interplay of capillarity, drainage height, and aqueous phase saturation on efficiency of mass transfer rate in permeability range similar to western Canadian heavy oil and bitumen reservoirs (i.e. 5.1–6.5D). In order to experimentally simulate the vapor extraction process, a new experimental approach was developed to eliminate the effect of pressure disturbances occurring during the course of experiment (20–45 days) and investigate the interplay between studied parameters in a gravity dominant system. In this study, measured stabilized drainage rates per unit length of porous media (9.17×10-7-3.33×10-5 cm3/s/cm) revealed functionality with drainage height, specific pore surface area of the porous medium, and presence of aqueous phase at higher capillarities. Moreover, analytical modeling was conducted to determine the effective diffusion/dispersion coefficient, which showed convective dispersion is not playing a prominent role in mixing between solvent and heavy oil as it was proposed by studies conducted in high permeabilities. In addition, comparison between the stabilized drainage rates of oil in absence or presence of water saturation confirmed that the presence of water phase enhances the drainage rates at higher capilarities, which is in contradiction with previous studies investigating the effect of aqueous phase saturation on mass transfer rate in higher permeabilities. This paper provides in-depth knowledge of the impact of three major parameters that affect the rate of the mass transfer between heavy oil and solvent, and that are necessary for realistic modeling of the performance of the vapor extraction process.
Geomechanical and Thermal Simulation of ES-SAGD Process
Authors: Deng Hui , Chen Zhangxin , Bao Xia , Wei Yizheng , Liu Hui , Dong Chao
Published: November 2011

Overlying top water and gas thief zones have a detrimental effect on the Steam-Assisted Gravity Drainage (SAGD) recovery process since steam penetrates into these zones which results in great heat loss. Due to the presence of these top thief zones, recovering bitumen by the SAGD process has become challenging for the Athabasca oil sands.

Numerical simulations, laboratory experiments and field production data have demonstrated that oil production tends to decrease as the depletion of top gas occurs; also, heat loss to the overlying thief zone will be more significant when a top water zone is present. Indeed, SAGD is a coupled geomechanical, thermal and fluid flow problem because continuous steam injection changes reservoir pore pressure and temperature, which can alter the effective stress in-situ. Therefore, to represent the physics of thermal flow and soil geomechanics, a coupled geomechanical simulation that solves the flow and stress equation simultaneously in the reservoir is crucial for modeling the SAGD process.

The objective of this paper is to construct a 3D geostatistical model for the Surmont pilot and implement coupled geomechanical modeling for the SAGD process aiming at investigating the impact of dilation and thermal expansion on the surface subsidence and bitumen recovery. Reasonable history match of oil and water rates has been achieved and steam chamber profiles have been conformed to the field data from the observation wells. An Expanding Solvent Steam-Assisted Gravity Drainage (ES-SAGD) process has been investigated on a full field-based heterogeneous simulation model using an optimal solvent mixture. Finally, geomechanical effects on the ES-SAGD process are investigated through an iterative coupling approach.
Production Analysis of Western Canadian Unconventional Light Oil Plays
Authors: Clarkson C. R. , Pedersen P. K.
Published: November 2011

Unconventional low-permeability (tight) light oil reservoirs have emerged as a significant source of oil supply in North America. As with unconventional gas reservoirs, these low-permeability oil plays exhibit a wide variety of reservoir characteristics, and consequently well-performance profiles. Further, different drilling and completion strategies are used to exploit them. In this work, we suggest that a categorization analogous to that used for unconventional gas reservoirs (i.e. based on reservoir/fluid properties) be used for unconventional light oil reservoirs because of the significant difference in reservoir and production characteristics observed to date in Western Canada. We propose the term "Unconventional Light Oil" (ULO) to capture the spectrum of play types and to distinguish them from unconventional heavy (high viscosity) oil plays. We further propose the following categories of ULO, which can be used as a practical guide for exploration and development: "Halo Oil" – light oil plays where the source ≠ the reservoir, and matrix permeability is relatively high (> 0.1 md) compared to the other categories. These plays represent portions of conventional light oil pools that do not meet traditional petrophysical cutoffs and pay criteria, and may be clastics or carbonates."Tight Oil" – light oil plays where the source ≠ the reservoir, and matrix permeability is low (< 0.1 md). These plays are analogous to tight gas plays and may be clastics or carbonates."Shale Oil" – light oil plays where the source = the reservoir, matrix permeability is very low, and organic matter content may be high. These plays are analogous to shale gas plays.

We note that for all three categories, modern completion (ex. horizontal wells) and stimulation methods (hydraulic fracturing) are required to commercially produce oil. We further note that the differences between these play types and their gas counterparts are not strictly related to fluid PVT differences.

In this work, we examine, using modern rate-transient analysis methods, differences in production characteristics of three ULO play types in Western Canada, and infer the primary controls on production performance in each. As expected, there are significant differences related to reservoir type and completion strategy.
Experimental Study of Simultaneous Athabasca Bitumen Recovery and Upgrading Using Ultradispersed Catalysts Injection
Authors: Hashemi R. , Pereira P.
Published: November 2011

The worldwide global demand for oil has grown to 80 million barrels per day, and is estimated to grow by 50% in next 20 years while conventional resources are declining. Unconventional reserve of heavy oil and bitumen has been considered as long term replacement for conventional resources. There are a large number of research projects in order to achieve this goal with technological efficiency. In situ upgrading of heavy oil and bitumen using Ultra Dispersed (UD) submicronic catalysts is a promising idea to improve the quality of produced liquid. In this process, hydrogen and a catalytic suspension are injected to the reservoir to react with heavy oil in the porous media. Nano catalyst particles enhance the recovery of oil by viscosity reduction. Series of experiments have been designed in an elemental model under typical reservoir condition. Tests are performed at a pressure of 500 Psi, residence time of 36 h, and temperatures from 300 to 340 (°C).

This paper presents the results of the in situ upgrading obtained along with the recovery of bitumen evidenced using ultra dispersed catalysts in an experimental rig. These experiments involve the injection of UD catalyst particles and hydrogen into a sand pack which is saturated with Athabasca bitumen. Produced liquids were analyzed with different techniques and results were demonstrated in recovery curves. Also, results of each experiment have been compared with base steam injection case to evaluate recovery performance of the catalyst suspended in a hot fluid. Temperature profile distributions and produced gas analysis are demonstrated to justify the quality of reaction through porous media. Produced liquids from media have higher API gravity and lower viscosity which shows a successful in situ upgrading process.
Examining the Effects of Stress Dependent Reservoir Permeability on Stimulated Horizontal Montney Gas Wells
Authors: Bachman R. C. , Sen V. , Khalmanova D. , M’Angha V. Okouma , Settari A.
Published: November 2011

The Montney gas play in NE British Columbia and NW Alberta is undergoing intense development utilizing multi-stage fracturing of horizontal wells. Problems persist in determining an optimal development strategy for each area within the Montney. For the Groundbirch area, operators are in the early stages of development. As a consequence they have invested significantly in well monitoring including microseismic, pressure build-ups, real time rate and pressure measurements and offsetting pressure observation wells. Conventional core analysis indicates that reservoir rocks have permeability in the micro-Darcy range. Lab experiments indicate permeability is also a function of the changing effective stress. Effective stress increases and permeability decreases as production occurs. A coupled geomechanical/reservoir study was performed after 400 days of production history in order to match behavior and determine the sensitivity of conventional production forecasts to the changing stresses within the reservoir.

This paper focuses on the performance analysis of a single Upper Montney well in the Groundbirch area. The approach is staged, with the analysis proceeding from the simple to the more complex. The first step involved an improved version of production analysis. After the identification of linear flow, the utility of a long neglected plot, dm/q versus superposition linear time is illustrated. The ability of this plot to accurately split production well performance into reservoir properties and skin effects introduced by the fracture treatments is shown. This has wide ranging implications for the industry. Finally a simple practical method has been found to compare performance of various types of horizontal multi-stage fracture treatments where the impact of reservoir properties has been removed.

In the second step of the study various descriptions of the study well were developed for all the processes the well encountered. These reservoir simulation models successfully matched treatment placement, an early build-up test distorted by clean-up effects and long term production behavior. Models types ranged from constant reservoir permeability through stress dependent permeability variation. Techniques were developed that eliminated the need to perform the time consuming geomechanical calculations. This allows the use of conventional reservoir models with pressure dependent permeability functions of a special form, to be used in day to day analysis. Sensitivity of the predicted production response with these models was then quantified.
Integration of Seismic Data and a Triple Porosity Model for Interpretation of Tight Gas Formations in the Western Canada Sedimentary Basin
Authors: Castillo Fernando , Aguilera Roberto , Lawton Don
Published: November 2011

A method is presented that integrates a triple porosity model with sonic, density and resistivity logs for evaluation of tight gas formations. The interpretation takes into account results from petrographic work in the Western Canada Sedimentary Basin (WCSB), which indicates that tight rocks are comprised of different types of pores including (i) intergranular, (ii) slot + microfractures, and (iii) isolated non-effective porosities.

Seismic data are powerful in the exploration and production domains but a method that integrates seismic velocities and the observed triple porosity petrographic characteristics of tight gas formations is not available. This paper provides the theoretical foundation and development of equations for this integration along with examples using real data from tight gas formations in the WCSB.

The proposed method provides estimates of inter-well formation resistivity, porosity and water saturation to obtain estimates of original gas in place. The comparison between resistivity from seismic velocities and resistivity from well logs is good with a strong statistical effectiveness. Under favorable conditions, the partition between effective and non-effective porosity might be estimated.

The proposed methodology has significant potential for application in tight gas formations of the WCSB. The method can probably be extended to other regions around the world, which possess tight gas formations with similar characteristics to the ones described in this work.
Living in the Shadows: Experiences of Undocumented Students
Authors: Singh Shailen M. , Byrd David A.
Published: November 2011

This article focuses on the experiences of undocumented students attending colleges and universities as a result of Texas House Bill 1403 / Senate Bill 1528. Through a qualitative interview, the authors seek to provide an overview of the issues and challenges many of these students face, as well as concepts for higher education professionals to focus on in order to better serve these students.The results of this case study indicate that these students face incongruent expectations based on whether they are on or off campus. On campus, they are of legal status with many of the same rights as their fellow students. Off campus, they face a number of challenges associated with being an undocumented immigrant. This stark dichotomy creates a remarkable tension through which these students navigate daily.
The Effect of Past Client Relationship and Strength of the Audit Committee on Auditor Negotiations
Authors: Brown-Liburd Helen L. , Wright Arnold M.
Published: November 2011

Auditors and clients are often required to resolve difficult, complex accounting issues in which they have different views. However, we know little about the effect of contextual factors on auditors' negotiation behaviors. This experimental study involving 63 experienced audit managers and partners examines the impact of the strength of the audit committee (strong or weak) and past relationship with the client (contending or compromising) on auditors' judgments in the pre-negotiation planning phase in resolving a difficult, subjective inventory writedown issue. These two important contextual factors are posited to affect auditors' perceived bargaining power and expectations of difficulties with respect to the impending negotiation. Specifically, we hypothesize an interaction where the most contending position (negotiation strategy) is adopted when the audit committee is strong (enhanced auditor bargaining power) and the past relationship is contending (a difficult negotiation). The findings support these expectations. In additional analyses, we obtain parallel results in the negotiation phase. In all, the findings confirm the importance of strength of the audit committee and past client relationship on auditors' negotiation planning judgments, and the concurrent consideration of these two pervasive contextual factors in the audit environment.

Data Availability: Contact the authors.