bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of weathering nodules of the ear in patients treated at the state civil servant's hospital of São Paulo, Brazil*
Authors: Cilento Juliana Nunes Maciel , Valente Neusa Yuriko Sakai
Published: March 2013

BACKGROUND: Weathering nodules of the ear are pale yellow, asymptomatic lesions which predominate on the helices of the ears. Although their pathogenesis remains unknown, there is an association with chronic exposure to ultraviolet radiation, age and thermal injuries. Few studies have been conducted to date, and these involved a very small number of patients. OBJECTIVE: Study the prevalence of weathering nodules of the ear in patients treated in the Dermatology Service of the State Civil Servant's Hospital of São Paulo, and evaluate their probable relationship with sun exposure, age and phototypes I and II. METHODS: Four hundred patients older than 20 years of age were examined between July 2008 and December 2008. A questionnaire evaluating age, sex, place of birth, origin, occupation and history of sun exposure was applied. All patients were examined and evaluated for the presence of lesions by only one person. RESULTS: The data showed that 155 (38.8%) patients had a lesion in at least one of the ears. The Chi-Square Test was used for the comparative analysis between the groups of patients with and without lesions. In the group of patients with lesions, 29% were 70 to 79 years old, 78.1% had a history of sun exposure and 45.1% belonged to FITZPATRICK skin phototypes I and II (p<0.05%). CONCLUSION: The findings suggest relevant prevalence, probable association with chronic sun exposure, advanced age and phototypes I and II.
How to design and write a clinical research protocol in Cosmetic Dermatology*
Authors: Bagatin Ediléia , Miot Helio A.
Published: March 2013

Cosmetic Dermatology is a growing subspecialty. High-quality basic science studies have been published; however, few double-blind, randomized controlled clinical trials, which are the major instrument for evidence-based medicine, have been conducted in this area. Clinical research is essential for the discovery of new knowledge, improvement of scientific basis, resolution of challenges, and good clinical practice. Some basic principles for a successful researcher include interest, availability, persistence, and honesty. It is essential to learn how to write a protocol research and to know the international and national regulatory rules. A complete clinical trial protocol should include question, background, objectives, methodology (design, variable description, sample size, randomization, inclusion and exclusion criteria, intervention, efficacy and safety measures, and statistical analysis), consent form, clinical research form, and references. Institutional ethical review board approval and financial support disclosure are necessary. Publication of positive or negative results should be an authors' commitment.
Generalized eruptive histiocytoma: a rare disease in an elderly patient*
Authors: Cardoso Fernanda ,   MD â€“ Graduate Course of Dermatology at the General Polyclinic of Rio de Janeiro (Policlínica Geral do Rio de Janeiro - PGRJ),  Brazil, Serafini Natália Battisti , Reis Brisa Dondoni , Nuñez Mónica Daniela Gauto , Nery José Augusto da Costa , Lupi Omar ,   Oswaldo Cruz Foundation (Fundação Oswaldo Cruz - FIOCRUZ),  Brazil,   PhD in Medicine (Dermatology) from the Federal University of Rio de Janeiro (Universidade Federal do Rio de Janeiro - UFRJ). Post-doctoral degree from the University of Texas Medical Branch (Galveston/TX between 2001 and 2002).Adjunct Professor of Dermatology at the Federal University oif the State of Rio de Janeiro (Universidad e Federal do Estado do Rio de Janeiro - UNIRIO),   Permanent Lecturer of Graduate Studies in Dermatology at the Federal University of Rio de Janeiro (Universidade Federal do Rio de Janeiro - UFRJ),   General Polyclinic of Rio de Janeiro (Policlínica Geral do Rio de Janeiro - PGRJ),  Brazil
Published: March 2013

Generalized eruptive histiocytoma is considered an extremely rare subtype of non-Langerhans cells histiocytosis. In the literature, there are few reports of this disease that mainly affects adults. In this report, we present a case of generalized eruptive histiocytoma in an elderly patient who had presented symptoms for over two months. Multiple erythematous papules, asymptomatic and symmetrically distributed were observed on the trunk and limbs. Histological examination showed a dense mononuclear cell dermal infiltrate. In the immunohistochemical analysis, the cells were CD68 positive, but CD1a, S100 and CD34 negative. A diagnosis of generalized eruptive histiocytoma was established. The aim of our paper is to report a case of a very rare disease, whose subtype and affected age group are even more unusual.
Sarcoid-like lesions in paracoccidioidomycosis: immunological factors*
Authors: Medeiros Vanessa Lucília Silveira de , Arruda Lúcia
Published: March 2013

The clinical presentation of paracoccidioidomycosis is spectral. Spontaneous cure, state of latency or active disease with different levels of severity can occur after the hematogenous dissemination. The morphology and number of skin lesions will depend on the interaction of host immunity, which is specific and individual, and fungus virulence. Some individuals have natural good immunity, which added to the low virulence of the fungus maintain the presence of well-marked granulomas with no microorganism and negative serology for a long time, making the diagnosis a challenge. Factors inherent to the fungus, however, may modulate the immune response and modify the clinical picture over the time. We present a sarcoidosis-like clinical presentation and discuss the immunological factors involved.
Toxic epidermal necrolysis induced by lansoprazole*
Authors: Fracaroli Tainá Scalfoni , Miranda Ludmilla Queirós , Sodré João Luz , Chaves Mário , Gripp Alexandre
Published: March 2013

Toxic epidermal necrolysis is a rare, severe cutaneous reaction, mostly caused by drugs. It affects the skin and mucous membranes, with involvement of more than 30% of body surface. We describe the case of a young woman, previously healthy, who developed skin detachment of more than 90% of the body surface 15 days after being administered lansoprazole for peptic disease. The treatment consisted in discontinuation of the drug involved and early administration of intravenous human immunoglobulin, which led to a satisfactory outcome of the case, substantiating the impact of early diagnosis and treatment on the morbidity and mortality of these patients.
Umbilical endometriosis: report of a case and its dermoscopic features*
Authors: Jaime Thais Jerez , Jaime Tatiana Jerez , Ormiga Patrícia , Leal Fabiano , Nogueira Osvania Maris , Rodrigues Nilton
Published: March 2013

Cutaneous endometriosis is a rare manifestation of endometriosis, representing 0.5% to 1% of all endometriosis cases. It can be divided into primary and secondary, when appearing spontaneously or after a surgical procedure, when it is mostly found on surgical scar tissue. Some etiologies were proposed, but none of them could entirely explain the appearance of the tumor. Differential diagnosis includes melanoma, metastatic nodule, keloid and pyogenic granuloma. Dermoscopic features are not yet well established, but there are some characteristics that suggest the diagnosis. Treatment is surgical in larger sized lesions. Malignization can occur. The screening for endometriosis is mandatory by means of gynecologic, imaging and marked-tumor evaluation. We report a case of primary umbilical endometriosis and discuss its dermoscopic aspects.
Dermoscopy revealing a case of Tinea Nigra*
Authors: Criado Paulo Ricardo , Delgado Lívia , Pereira Gustavo Alonso
Published: March 2013

Dermoscopy has being used over the past twenty years as a noninvasive aid in the diagnosis of innumerable skin conditions, including infectious diseases and infestations (Entodermoscopy).Tinea nigra is a superficial phaeohyfomycosis that affects mainly the glabrous skin of palms and soles. We describe a 14 year-old girl with a three-month history of an enlarging brown patch of her hand diagnosed as Tinea Nigra following clinical and dermoscopy examination.These images emphasize the importance of dermoscopy as a diagnostic tool in the daily routine of dermatologists.
Case for diagnosis
Authors: Maio Paula , Fernandes Candida , Afonso Ana , Sachse Fernanda , Cabeçadas José , Cardoso Jorge
Published: March 2013

Blastic plasmacytoid dendritic cell tumor is a rare, highly aggressive systemic neoplasm for which effective therapies have not yet been established. We describe a 73-year-old man with multiple nodules and patches emerging on the trunk and limbs. Lesional skin biopsy revealed a plasmacytoid dendritic cell tumor with dense dermal infiltrate of tumor cells with blastoid features. No apparent systemic involvement was identified in the initial stage. The patient was treated with prednisone daily, with notorious improvement of the skin lesions, although no complete remission was obtained. During the six-month follow-up period, no disease progression was documented, but fatal systemic progression occurred after that period of time.
Do you know this syndrome?
Authors: Frainer Renata Hubner , Abreu Luciana Boff de , Pinto Giselle Martins , Carvalho André Vicente Esteves de , Meneghello Luana Pizarro
Published: March 2013

Congenital hypotrichosis and Stargardt macular dystrophy are rare autosomal recessive disorder of unk nown etiology respectively characterized by hair loss, macular degeneration and severe progressive vision reduc tion. There are few reports in the literature with this association. Studies show that the defective gene is on the chro mosome I6q22.1 and involve cadherin molecule in the pathogenesis. Early recognition of these disorders often starts with hair changes and should alert the dermatologist for an eye examination thereby avoiding more severe ocular defect.
Ferdinand Oyono'sUne vie de boyon the World Literary Stage
Authors: Moore David Chioni
Published: March 2013

Some of you know that my grandfather was a cook for the British in Kenya, and though he was a respected elder in his village, his employers called him “boy” for much of his life.

—Barack Obama, president of the United States, speaking to the Parliament of Ghana, Accra, 11 July 2009

How do you saykhakiin fourteen languages? assuming that the answer is, in most cases, more or lesskhaki, what might that word mean? This question occurred to me three years ago as I was sitting in my Minnesota office with a student—a brilliant sophomore economics major from Hanoi—trying to understand a thorny text from Cameroon. The text before us was the Vietnamese translation of Ferdinand Oyono's landmark 1956 francophone anticolonial novelUne vie de boy, which I had been pondering for years. A central figure in the novel, the village's French commandant, was often depicted in “son short kaki” (“his khaki shorts”). Though I don't speak Vietnamese, I could make out enough of its modified Latin alphabet to recognizekakiseveral times in the 1997 translation. In seeking its Vietnamese meaning, I knew that at least six languages were already in play:kakicame to Oyono's French from English, which got the word in the mid-nineteenth century from Hindi-Urdu (where it means dust-colored), which got it from the Persian(transliterated “khakeh”), meaning dust (“Khaki”). What is more, Oyono's novel purports to be translated from the Ewondo, wherekakicertainly meant something too. But in Vietnamese? My instinct was thatkhaki, at least in Vietnam, would signify what it did in Cameroon: the iconic colonial oppressor's fabric. But when my student, Phuong Vu, saw the word in Vietnamese, she immediately searched for an image on her laptop, then showed me a photo of the greatanticolonialleader of Vietnam: the khaki-wearing Ho Chi Minh. Seeking a further data point, I asked my dean, the Somali scholar Ahmed Samatar, whatkhakimeant in his mother tongue. His reaction, too, was instant: “my grandfather was the first man in our village to wear khaki: it signifies modernity!”Khaki:one word, worldwide. But clearly not a monosignifying word, since it means, at minimum, dust, dust-colored, modernity, colonization, and anticolonial resistance. To paraphrase Langston Hughes, what kind of a translation can you make out of that?
Oyono in Arabic
Authors: Hassan Waïl S.
Published: March 2013

A rendition by nayif kharma of michael etherton's theatrical adaptation of john reed's english translation, the arabic version of Ferdinand Oyono's novel Une vie de boy is at three removes from the original French. Under the title Al-khādim (“The Servant”), the play appeared in 1982 in the series Min al-masrah al-'ālami (“From World Theater”), published by Kuwait's Ministry of Culture. Since to all effects and purposes Etherton's theatrical adaptation is Kharma's original, it is necessary to begin by describing how the Zambian-born British writer who taught drama at the University of Zambia in the 1960s adapted his source, Reed's Houseboy, before discussing how the play was later Arabized.
Majors and Minors in Europe's African Enterprise: Oyono's Une vie de boy in Danish and Swedish Translations
Authors: Lindqvist Ursula
Published: March 2013

The publication of ferdinand oyono's anticolonial novel une vie de boy (1956) in three scandinavian-language translations—danish, Swedish, and Nynorsk Norwegian—in the 1960s and 1970s coincided with a surge of pan-Nordic interest in African culture and liberation movements. This outward turn was part of a major shift in the construction of national and regional identities in the Nordic region—particularly in Denmark and Sweden. Once minor European kingdoms with modest colonial holdings on several continents (including Africa), these considerably downsized modern nation-states were forced to reposition themselves on the world stage starting in the twentieth century. Africa's anticolonial movements presented an opportunity for the Nordic region to embrace a new global role: that of nations of conscience whose leadership on human rights issues granted them influence and authority far beyond the size of their military, population, gross domestic product, or cultural and linguistic presence in the world. While the importance of this leadership among Western nations—particularly in fighting apartheid—can hardly be disputed, it has, paradoxically, also made it possible for Scandinavians to distance themselves from their own colonial involvement in Africa and to focus instead on the more extensive, visible, and enduring colonial histories of other European nations, mainly France and England.
Oyono in Slovene: Toundi's Visit to Yugoslavia
Authors: Žagar Monika
Published: March 2013

In 1979 the publishing house mladinska knjiga released the slovene translation of ferdinand oyono's une vie de boy (1956) as Življenje hišnega služabnika. The book appeared largely as a result of an order “from above” in what was then Yugoslavia, mandating publication of texts by writers from Nonaligned Movement (NAM) countries. Marjana Samide, the translator, had previously translated From a Crooked Rib (1970), by the Somali writer Nuruddin Farah (Upognjeno rebro [1978]), and she was given Une vie de boy by a Mladinska knjiga series editor because both authors, Farah and Oyono, were from Africa, seen evidently as a unitary place.
The New Unhistoricism in Queer Studies
Authors: Traub Valerie
Published: March 2013

In the name of “homohistory,” “queer temporality,” and “unhistoricism,” some early modernists have accused queer historicists of promoting a normalizing view of sexuality, history, and time. These early modernists announce their critique of the “straight temporality” allegedly caused by a framework of teleology as a decisive break from previous methods of queer history. Using the accusation of teleology as an analytic fulcrum, this essay scrutinizes these scholars' assumptions regarding temporality, representation, periodization, empiricism, and historical change. Ascertaining the conceptual work that the allegation of teleology performs, I reconsider the meanings and uses of the concept queer, as well as homo and hetero, in the context of historical inquiry. I also assess some of the affordances of psychoanalysis and deconstruction for the history of sexuality. At stake are not only our emerging understandings of the relations between chronology and teleology, sequence and consequence, but also some of the fundamental purposes and destinations of queering.
Reading on the Move
Authors: Koepnick Lutz
Published: March 2013

It is often said that proper reading relies on the art of taking a pause: On our abilityto suspend the pressing rhythms of the everyday and allow ourselves to absorb, and be absorbed by, alternative structures of temporality. The clocks of the imagination do not run at the same speeds as the timetables of the real; to read is to inhabit the present at one's own pace and in the light of a multitude of unknown pasts and possible futures. Recent years have witnessed a swell in publications pondering the state of reading in our world of instant connectivity and shrinking attention spans. In one of these books, Jane Smiley, a Pulitzer Prize winner, considers the peculiar acts of writing and reading a novel as profound contributions to the process of enlightenment—a kind of enlightenment enlightened about itself and no longer repressing the other of reason: “The way in which novels are created—someone is seized by inspiration and then works out his inspiration methodologically by writing, observing, writing, observing, thinking through, and writing again—is by nature deliberate, dominated neither by reason nor by emotion” (176). According to Smiley, the act of reading a novel re-creates an author's deliberate negotiation of affect and rationality. As readers follow the lines of a (good) book, they remain in relative control over the speed of their reading, able to pause when necessary, to hasten forward when desiring so, to reread passages at their leisure, and to close the pages of the book when overtaken by exhaustion. Good stories rely on intricate plot constructions and narrative tensions, but they also situate readers as subjects freed from the temporal determination and ideological drive of other time-based media. Good books can certainly move readers, but—following Smiley's logic—they will not curtail a reader's freedom to move along the text at his or her own speed, and hence they will allow this reader to simultaneously bring into play emotion and reason, the absorptive and the distant.
“Words with Friends”: Socially Networked Reading onGoodreads
Authors: Nakamura Lisa
Published: March 2013

Reading isn't what it was. As we enter the “late age of print,” E-Books are still less common than “P-Books” (printed books), but the balance is quickly changing, especially in the world of academic publishing (Striphas xii). While many lament the loss of the p-book's materiality, texts have become more lively as a result of digitization: textual-production platforms like blogging let writers and readers interact with each other and create intimate social relationships. As Kathleen Fitzpatrick found while writing her bookPlanned ObsolescenceusingCommentPress, an online platform that enables readers' commenting, writing can become a more social and creative process when done in dialogue with readers. This turn to the social in writing parallels a turn to the social in media generally. Thus, it makes sense to evaluate not how far our devices are taking us from paper—the answer is already pretty far—but rather how digital media are creating new social valences of reading.
Homer in a Nutshell: Vergilian Miniaturization and the Sublime
Authors: Young Elizabeth
Published: March 2013

This paper explores the strange fascination with smallness that runs through Vergil's Aeneid, focusing on the bee simile in book 1, the poem's inaugural miniaturizing moment. Deviating from the standard paradigms of Vergilian criticism, I suggest we can learn a great deal about smallness in this poem by studying it through the lens of the sublime. My analysis bypasses the proliferation of Romantic sublimes to draw primarily on a model of sublimity derived from Neil Hertz's influential reading of Longinus. Read through the Hertzian sublime, miniaturization in the Aeneid is revealed as a subtle articulation of the poem's running concern with power. The bee simile, I argue, enacts a threefold drama in which hero, author, and reader confront what I call their sublime condition, coming to terms with their implication in immensities beyond their comprehension and control.
Ground improvement efficiency and back-analysis of settlements
Authors: Debats Jean-Marc , Scharff Grégory , Balderas Juan , Melentijevic Svetlana
Published: March 2013

The ground improvement works carried out for the construction of five oil tanks at the Chiriqui Grande Phase II Oil Terminal, Chiriqui Grande, Panama, and their results are presented herein. The site is underlain by some 28 m of loose/soft, poorly graded, silty sands to clayey sands and silts. Ground improvement was used to provide the required bearing capacity and reduce the expected total and differential settlements. To fulfil the technical specifications, two ground improvement techniques were used in association with preloading: wick drains to full depth of the soft layers and stone columns in the upper 18 m. Stone columns are commonly installed as partial replacement to improve a soft ground, increasing its bearing capacity and accelerating its primary consolidation. Wick drains are used to accelerate the consolidation of soft clayey soils. Particular emphasis was given to the behaviour of the treated ground under the preloading fill: a back-analysis was carried out on measured settlements and pore pressures; the improvement of the ground and the degrees of consolidation achieved at the end of the preloading are highlighted; some correlations were derived and they provide an interpretation of the overall behaviour of the improved ground; estimates of the settlements for the short and long term are presented, the short term being that of the hydrotest and the long term being the design life of the oil terminal. They are based on results of preloading for their primary consolidation part, and on reasonable assumptions for their long-term creep (secondary consolidation) part. The estimates are compared to the actual hydrotest survey results.
Model of flow over spillways by computational fluid dynamics
Authors: Chinnarasri Chaiyuth , Kositgittiwong Duangrudee , Julien Pierre Y.
Published: March 2013

The objective of the present study was to simulate the flow behaviour through smooth, 25-step and 50-step spillways using a multiphase flow model with the realisable k–ε model. The simulation results were compared with the data from a large-scale physical model. A grid convergence index was used to reduce the discretisation error. The simulation results of flow along stepped spillways and the flow on the step agreed well with experimental data for both smooth and stepped spillways. The flow profiles, velocity profiles, turbulence intensity, and energy dissipation of flow through spillways are illustrated and discussed. Expressions for the turbulence intensity distributions in smooth and stepped spillways are also proposed.
Modeling the relationship between propagule pressure and invasion risk to inform policy and management
Authors: Wonham Marjorie J. , Byers James E. , Grosholz Edwin D. , Leung Brian
Published: March 2013

Predicting population establishment based on initial population size is a theoretically and empirically challenging problem whose resolution informs a multitude of applications. Indeed, it is a central problem in the management of introduced, endangered, harvested, and pathogenic organisms. We focus here on introduced species. We synthesize the current state of modeling in this predictive enterprise and outline future directions in the application of these models to developing regulations intended to prevent the establishment of invaders. Descriptive and mechanistic models of single‐population introductions are fairly well developed and have provided insight into invasion risk in laboratory and field conditions. However, many invasions stem from large‐scale and repeated releases of a multitude of species from relatively indiscriminate invasion vectors associated with international trade and travel. Vector‐scale models of invasion risk are less well developed and are characterized largely by the use of untested proxy variables for propagule pressure. We illustrate the problems associated with proxy variables and introduce a more mechanistic theoretical formulation characterizing vector‐scale invasion pressure in terms of propagule pressure (number of introduced individuals) and colonization pressure (number of introduced species). We outline key questions to be addressed in applying both single‐population and vector‐scale models to the development of threshold‐based invasion regulations. We illustrate these ecological and applied questions using examples from terrestrial, aquatic, and marine systems. We develop in detail examples from ballast‐water transport that, as one of the best‐characterized global invasion vectors and one that is subject to emerging international threshold‐based biosecurity regulations, provides a rich case study.
The past ecology of Abies alba provides new perspectives on future responses of silver fir forests to global warming
Authors: Tinner Willy , Colombaroli Daniele , Heiri Oliver , Henne Paul D. , Steinacher Marco , Untenecker Johanna , Vescovi Elisa , Allen Judy R. M. , Carraro Gabriele , Conedera Marco , Joos Fortunat , Lotter André F. , Luterbacher Jürg , Samartin Stéphanie , Valsecchi Verushka
Published: March 2013

Paleoecology can provide valuable insights into the ecology of species that complement observation and experiment‐based assessments of climate impact dynamics. New paleoecological records (e.g., pollen, macrofossils) from the Italian Peninsula suggest a much wider climatic niche of the important European tree species Abies alba (silver fir) than observed in its present spatial range. To explore this discrepancy between current and past distribution of the species, we analyzed climatic data (temperature, precipitation, frost, humidity, sunshine) and vegetation‐independent paleoclimatic reconstructions (e.g., lake levels, chironomids) and use global coupled carbon‐cycle climate (NCAR CSM1.4) and dynamic vegetation (LandClim) modeling. The combined evidence suggests that during the mid‐Holocene (∼6000 years ago), prior to humanization of vegetation, A. alba formed forests under conditions that exceeded the modern (1961–1990) upper temperature limit of the species by ∼5–7°C (July means). Annual precipitation during this natural period was comparable to today (>700–800 mm), with drier summers and wetter winters. In the meso‐Mediterranean to sub‐Mediterranean forests A. alba co‐occurred with thermophilous taxa such as Quercus ilex, Q. pubescens, Olea europaea, Phillyrea, Arbutus, Cistus, Tilia, Ulmus, Acer, Hedera helix, Ilex aquifolium, Taxus, and Vitis. Results from the last interglacial (ca. 130 000–115 000 BP), when human impact was negligible, corroborate the Holocene evidence. Thermophilous Mediterranean A. alba stands became extinct during the last 5000 years when land‐use pressure and specifically excessive anthropogenic fire and browsing disturbance increased. Our results imply that the ecology of this key European tree species is not yet well understood. On the basis of the reconstructed realized climatic niche of the species, we anticipate that the future geographic range of A. alba may not contract regardless of migration success, even if climate should become significantly warmer than today with summer temperatures increasing by up to 5–7°C, as long as precipitation does not fall below 700–800 mm/yr, and anthropogenic disturbance (e.g., fire, browsing) does not become excessive. Our finding contradicts recent studies that projected range contractions under global‐warming scenarios, but did not factor how millennia of human impacts reduced the realized climatic niche of A. alba.
Spatial generality of predicted occurrence models of nesting habitat for the greater sage‐grouse
Authors: Dzialak Matthew R. , Olson Chad V. , Harju Seth M. , Winstead Jeffrey B.
Published: March 2013

We investigated generality of resource‐based models of predicted occurrence as part of an effort in spatial prioritization of habitat for conservation in shrub‐steppe landscapes of western North America. Using GPS telemetry data on the greater sage‐grouse (Centrocercus urophasianus), we investigated whether spatial models developed in particular regions of Wyoming, USA were generalizable to other portions of the state, whether generality versus region‐specificity were mediated by behavior state, and why models were either general or region‐specific (i.e., what factors constrained versus promoted generality). The behavior states we examined were nest‐site selection, and resource selection during nesting off‐bouts. We tested generality by developing models within the region at which location data were collected, applying models across regions (3 different hydrologic basins), using independent location data to validate, and subsequently analyzing a validation parameter (Spearman's rho) in a beta regression model. In a spatial application, we combined information on nest site selection and off‐bout occurrence to develop predictive occurrence maps that account for multiple biological processes influencing occurrence during the nesting period. Models of nest site occurrence showed considerable generality, but models of occurrence during off‐bouts did not. Habitat‐occurrence relationships associated with generality included inter‐region consistency in sagebrush coverage, and importance (selection/avoidance) of linear features (rights‐of‐way) and natural gas wells. Relationships associated with region‐specificity included importance of mesic habitat and bare ground. These findings suggest generality is mediated by behavior state, with certain behavior more generalizable than other behavior. Features of generalizable behavior included a relatively well‐defined niche and historical constraints (in this case, nest‐area fidelity); features of region‐specificity included influences on behavior that were more local/variable in space and time (i.e., functional responses). Implications for conservation are that, in the shrub‐steppe and perhaps other systems, a steadfast need for region‐specific data to parameterize occurrence models is not universal, with some behavior (i.e., nest‐site selection) amenable to spatial prediction across large areas based on relationships identified in the species elsewhere.
Investigation of Low Frequency Water Hammer for Extended Reach Applications
Authors: Macdonald R. , Jennings B. , Vecseri G.
Published: March 2013

Horizontal wellbores typically encounter inefficiencies due to friction during both drilling and completions operations. In severe cases, further advancement of the bit or downhole tools is almost impossible due to the inability of existing technology and methods to overcome downhole friction forces. This problem, seen in drilling, completions, and intervention activities, is particularly acute in coil tubing deployed bottom hole assemblies (BHA). Fluid hammer tools are often used in an attempt to mitigate this friction, with varying degrees of success. Current commercially available fluid hammer tools are preset mechanical systems operating at relatively high frequencies from 12 to over 40 Hz. These tools, which cannot be deactivated once installed in the BHA, typically exhibit a large pressure drop which can rise even further with increased flow. It is proposed that a downhole pressure oscillation tool be developed that provides the capability to manage downhole pressure oscillation amplitude independent of flow rate. It is also proposed that such a tool, operating at low frequencies, could simultaneously encode downhole measurements within the pressure pulse signal. This paper presents experimental data collected in the development of such a system and further explores the theory that high amplitude oscillations at lower frequencies impart significant motive force to the BHA enabling extended reach.
Development of a New CT Life Tracking Process
Authors: Newman Kenneth R
Published: March 2013

A new process has been developed to track the life of coiled tubing (CT) strings. This paper documents the development of this process, including the material models and the software tools used by the process. The results of this process are a prediction of the CT life and diametrical change along the length of the CT. When the process is used for multiple CT strings, statistical metrics about the strings can be mined from a web based database.
Successful Case Histories for the Next Generation 3D CFD-Derived Fluidic Oscillator
Authors: Howard Robert , Martinez Ismael , Hunter Tim
Published: March 2013

Near-wellbore (NWB) stimulation continues to evolve and change over time as a wide variety of tools and processes designed to target this problem area of the borehole are being developed. Fluidic oscillators (FOs) are amongst some of the most simple and successful tools to affect this region; however, even after decades of multidiscipline industry development, there is still room for improvement.

This paper discusses the search for the perfect oscillator design for NWB stimulation using solid modeling and 3D computational fluid dynamics (CFD). These tools allowed fast and efficient evaluation of hundreds of concepts to optimize features of the selected design without the need for prototype testing during each design iteration. As a result, many months of development time were saved by eliminating repeated manufacturing and testing activities. The best possible solution was then validated in the laboratory using rapid-prototype models, machined prototypes, and ultrahigh-speed photography.

The main purpose of this paper is to focus on the case histories collected during field testing and commercialization of the new design. Pre- and post-treatment production figures, infield well comparisons with competing technologies, and repeat treatments originally performed with previous versions best showcase the superior performance from the advances made to the tool and treatment process and are used whenever possible.

The results prove what laboratory testing predicted—the improvements translated to superior stimulation results.
Innovative Coiled Tubing Technology to Improve Performance in Horizontal Completions
Authors: McClelland Garry , Tubing Global
Published: March 2013

Recent technological innovations in seismic imaging, directional drilling and hydraulic fracturing and other completion techniques have made development of unconventional hydrocarbon resources economically feasible. Coiled tubing is an integral component in completing most unconventional wells. However, the life of coiled tubing used in such applications has been negatively affected by higher well pressures often coupled with larger pipe diameters relative to wall thicknesses ("D/T Ratios"), as well as sinusoidal and helical buckling unique to horizontal completions. Such stresses frequently manifest in bias welds present in certain portions of the coiled tubing string, affecting both fatigue life and potentially operational safety.

It has long been understood that higher wall thicknesses improve the fatigue performance of coiled tubing, including bias welds. However, higher wall thicknesses throughout the length of the tubing may increase the weight of the coiled tubing strings to unacceptable levels. Technology now exists to provide coiled tubing strings with greater wall thicknesses at the bias welds while maintaining the thinner nominal wall thickness over the majority of the body of the tubing. This provides the ultimate in design flexibility for engineering a coiled tubing string with optimized reach, weight, overpull, fatigue life and safety.

This paper presents data demonstrating the improved performance of coiled tubing with increased localized wall thickness at the bias welds, and outlines the string design flexibility offered by this technology for engineering the next generation of coiled tubing.
Successful Oriented Hydrajet Perforation and Fracture Stimulation of a Highly Deviated Tight-Gas-Producer Well Completed in the Casing/Liner Overlap Section
Authors: Gomez Francisco , Al-Asiri Mohammed , Al-Mutary Talal , Abass Hazim , Sierra Leopoldo , Vielma Jose R.
Published: March 2013

Hydraulic fracturing is essential for stimulating tight-gas reservoirs, where hydrocarbon recovery is optimized by placing long and conductive fractures. It has been established in the oil and gas industry that placing hydraulic fractures in vertical wells can be achieved with a good degree of confidence; however, when the wellbore is deviated from the vertical plane, completion challenges can negatively impact the proper placement of the fracture and stimulation. Moreover, if wellbore deviation is very high (greater than 65°) and the formation to be fracture stimulated is located in the overlap of the last casing and production liner, achieving effective stimulation can be even more challenging.

Perforation, completion, and fracture stimulation of tight-gas reservoirs performed in highly deviated wellbores that are located in the overlap of the casing/liner is not common practice within the industry; when this situation is encountered, performing effective fracture stimulations is often considered impossible because of operational challenges and screenout risks.

This paper presents a case history of a successful perforation and fracture stimulation of a deep tight-gas reservoir where the wellbore was highly deviated (65°) and was located between a 7-in. casing and 4 1/2-in. liner overlap. Wellbore perforation was performed using an innovative oriented hydrajetting process, where the perforated interval was aligned to the plane of the maximum stress. Additionally, this paper documents the innovative isolation of the openhole section located below the zone to be fractured using a chemical packer.
Combining Tools to Increase Efficiency in Challenging Wellbore Cleanouts
Authors: Li J. , Lindsey B. J. , Rahimov K. , Smith S.
Published: March 2013

More than 30% of coiled tubing (CT) operations worldwide are related to debris removal from a wellbore. The process is affected by multiple variables including fluid properties/velocities, particle properties, wellbore geometry and deviation, pipe size and eccentricity, fill penetration rate, and wiper trip speed. Debris cleanout with CT is challenged by the achievable pump rates and lack of pipe rotation. This challenge is further compounded by highly deviated or horizontal well trajectories, especially in large-diameter wellbores with low bottom-hole pressures.

A hydraulically actuated, switchable circulation sub was developed a decade ago. While running into the well, forward jets of the sub help break down debris. While pulling out of the well, the tool is switched to a low resistance, backward jetting mode, which sweeps debris more efficiently using higher flow rates. However, in some challenging conditions such as compacted sand columns, or scale in extended wellbores, the sub has to be combined with other downhole tools to meet operational requirements. This paper discusses how to combine the switchable circulation sub with a tractor, water hammer tool, and a mud motor/bit. It goes on to demonstrate a means of verifying the tool is operated correctly using real time downhole signals transmitted by a small but robust conductor inside the CT.

The benefits of this combination are multi-fold. First, while running into the well the tractor or water hammer tool helps to reach target depth. While pulling out of the well, the switchable circulation sub cuts off flow to the lower BHA (bottom hole assembly), stopping the bit/PDM (positive displacement motor) and/or idling the tractor or water hammer tool. At the same time, the flow rate can be increased with relatively lower surface injection pressures improving the hole-sweeping efficiency and pipe fatigue life. A few field case histories are presented to demonstrate the benefits of these special BHAs in improving operational efficiency. The challenges, benefits, and lessons learned during these operations are reviewed.
Extending the Operating Life of Mature North Sea Assets by Big-Scale Offshore Installation of Large-Diameter Chrome Coiled-Tubing Velocity Strings
Authors: de Jonge R. M. , Ambergen D. , Tousis U. A. , Veeken K. , Hoekstra L. , Gesterkamp S.
Published: March 2013

In the Southern North Sea, many fields are suffering from declining gas production due to depletion of the reservoir and associated liquid loading. At some time during the operating life of offshore production facilities, the ability for these facilities to keep operating economically at a further decline in gas production, will need to be evaluated. To avoid early abandonment of these offshore assets, well deliquification or liquid unloading techniques, like Velocity String (VS) installations, are considered for extending the operating life of these mature fields.

Large diameter (2 3/8 and 2 7/8-in.) chrome coiled tubing (CT) strings are being installed in deep gas wells in the Southern North Sea, as part of a large-scale installation project, including some 20 wells over a period of two years. A self-propelled jackup work vessel is used to house all the coiled tubing, well test and associated equipment needed to enable well interventions on the small production platforms and NUI’s (Normally Unmanned Installations). Critical to the success of the project was the cross-discipline approach to preparing, selecting and testing appropriate coiled tubing hardware and tools, hazard analyses and logistical coordination.

In this paper the preparation of the project, the operational details and lessons learned are presented. Candidate well-selection criteria and the choice for the selected coiled tubing material and size are discussed as well. Due to the size of the project, which is a worldwide first of this magnitude and set-up, both in terms of investment and quantity of offshore installations, good case histories for large diameter offshore chrome velocity string installations are provided.

At time of writing not all the velocity strings have been installed. The velocity strings installed thus far have yielded incremental gas production of the order of 50,000-150,000 sm3/d (1.7 – 5.3 Mscf/day) per well, which is in line with expectations. Based on the initial production results and production expectations for the remainder of the wells, the production life of these assets is expected to extend with many years.
Stuck Coiled Tubing: Addressing the Risks in a Complex Operating Environment
Authors: Burgos Rex , Mallalieu Robin
Published: March 2013

Stuck coiled tubing (CT) remains among the major operational risks when performing a CT well intervention. Stuck pipe incidents normally result in considerable production delays or—even worse—possible loss of the well. The mechanisms for stuck pipe are varied, and over the years, the industry has relied on tried and tested "rules of thumb" to address the risk under different operating scenarios.

Today, CT well intervention is more popular than ever. With service demand on the rise, the application envelope for this versatile technology continues to expand. Over the last decade, however, the profile of the wells where CT intervention is featured has also evolved. If anything, the operating environment for today’s intervention is more challenging, involving difficulties in wellbore trajectory and complexities in the completion, as well as an array of sophisticated tool assemblies requiring conveyance. During this period, the approach to stuck pipe avoidance or prevention has more or less remained steadfast.

A study performed on a decade’s worth of data (2001 to 2010) from sticking incidents for a leading CT service provider identified the changes and trends in the mechanisms for sticking as the operating environment has evolved. More importantly, recommendations for addressing the associated risks with the expanded application envelope are proposed.
Rheological Properties of Surfactant-Based and Polymeric Nano-Fluids
Authors: Fakoya M. F. , Shah S. N.
Published: March 2013

Nanotechnology is well established in several industries. However, the emergence of its application is recent in the oil and gas industry; a fact corroborated by the current surge of publication in literature. Interestingly, advancement in research has shown that nanotechnology can improve the rheological properties of surfactant-based fluids (SBF) and polymeric fluids.

To date, this application focuses more on polymeric fluids than on SBF. Furthermore, a few or none of the studies address the detrimental effect of nanotechnology on rheological properties of these fluids once certain limits are exceeded. Likewise, little or no information is available regarding the application of nanotechnology in SBF-polymeric fluid blends.

This paper presents an experimental investigation of nanotechnology on the rheological properties of SBF, polymeric fluids, and SBF-polymeric fluid blends. The surfactant-based and polymeric fluids are composed of 5% SBF in 4% KCl and 33 lb/Mgal guar in 4% KCl respectively. Blend A was prepared by adding 75% vol. of surfactant-based fluid to 25% vol. of polymeric fluid; while Blend B resulted from the addition of 25 and 75% vol. of these fluids. The 20 nm silica nanoparticles were added to achieve three nano-fluid concentrations (0.058%, 0.24%, and 0.4% wt.) for each clean fluid. Rheological data were gathered by conducting viscometry and frequency sweep tests using the Bohlin CS-50 rheometer within a temperature range of 75 to 175 °F. The results indicate that 20 nm silica nanoparticles are beneficial in terms of enhancing rheological properties in surfactant-based and polymeric nano-fluids up to particle concentration of 0.24% and 0.4% respectively. Blend A nano-fluids show similar results at 0.058%, and only at 0.4% at high shear rates. Similarly, Blend B displayed favorable results up to 0.24% and at high temperature applications only (125 to 175 °F). Finally, relative viscosity correlations are developed for predicting viscosity of nano-suspensions.

The application of nanotechnology on the rheological properties of SBF, polymeric fluids, and SBF-polymeric fluid blends delivers on great benefits, if nanoparticle concentrations are carefully selected. These nano-fluids will be applicable for oilfield operations such as hydraulic fracturing.