bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anomalously weak solar convection
Authors: Hanasoge Shravan M. , Duvall Thomas L. , Sreenivasan Katepalli R. 
Published: June 2012

Convection in the solar interior is thought to comprise structures on a spectrum of scales. This conclusion emerges from phenomenological studies and numerical simulations, though neither covers the proper range of dynamical parameters of solar convection. Here, we analyze observations of the wavefield in the solar photosphere using techniques of time-distance helioseismology to image flows in the solar interior. We downsample and synthesize 900 billion wavefield observations to produce 3 billion cross-correlations, which we average and fit, measuring 5 million wave travel times. Using these travel times, we deduce the underlying flow systems and study their statistics to bound convective velocity magnitudes in the solar interior, as a function of depth and spherical-harmonic degree
ℓ
. Within the wavenumber band
ℓ
< 60, convective velocities are 20–100 times weaker than current theoretical estimates. This constraint suggests the prevalence of a different paradigm of turbulence from that predicted by existing models, prompting the question: what mechanism transports the heat flux of a solar luminosity outwards? Advection is dominated by Coriolis forces for wavenumbers
ℓ
< 60, with Rossby numbers smaller than approximately 10
-2
at
r
/
R
⊙
= 0.96, suggesting that the Sun may be a much faster rotator than previously thought, and that large-scale convection may be quasi-geostrophic. The fact that isorotation contours in the Sun are not coaligned with the axis of rotation suggests the presence of a latitudinal entropy gradient.
Growing a vocabulary
Authors: Meara Paul 
Published: June 2012

This paper describes how simple Boolean Network models can be adapted to explore the way a vocabulary network might grow. The models described have two main parameters — a New Word parameter, which determines the rate at which new words are added to the lexicon, and an independent New Link parameter, which determines the rate at which links form between words. Delaying the application of the New Link parameter by a small amount allows a core of words to establish itself. With these very simple assumptions, a network structure with some of the features of real lexicons can grow itself.

The paper describes how the parameter values interact, and how the size of the initial core affects the way the lexicon grows. The paper also speculates about how a more realistic model of lexical growth might be constructed by making the basic processes in the models slightly more complex.
Marking Otoliths and Fin Spines of Juvenile Shortnose Sturgeon with Oxytetracycline and the Effects of Water Temperature during Treatment
Authors: Crumpton Roman L. , Henne James P. , Ware Kent M. 
Published: June 2012

Abstract
In order to evaluate a stocking program for shortnose sturgeon Acipenser brevirostrum that uses captive propagation to supplement wild populations, methods are needed to differentiate wild and hatchery-reared individuals. Recently, methods have been established for marking juvenile shortnose sturgeon in oxytetracycline hydrochloride (OTC) baths, and the marks have been confirmed on both sagittal otoliths and first-ray pectoral fin spines. However, considerable variability of mark quality has been observed on both structures, and sacrificing the fish for otolith removal is undesirable due to the shortnose sturgeon's endangered status. The objectives of this study were to determine the impact of water temperature during OTC marking on otolith and fin spine mark quality and to determine whether fin spines are as reliable as otoliths for detecting OTC marks. Six groups (N = 90) of hatchery-produced shortnose sturgeon fingerlings were exposed to 750-mg/L OTC baths for 12 h at two temperatures (heated and ambient). After marking was complete, fish were raised for 21 d, then euthanized. Otoliths and fin spines were independently analyzed by two readers, and a mark quality score (0, 1, or 2) was assigned based upon detectability. Fish marked at warmer temperatures (heated treatment) exhibited superior mark quality (mean ± standard error of the mean mark quality = 1.78 ± 0.07) on their otoliths than those marked in the cooler baths (ambient treatment; 1.27 ± 0.09). Similar results were observed for fin spines. Mark quality on fin spines and otoliths was not found to be significantly different. This research demonstrates the ability to chemically mark otoliths and fin spines of juvenile shortnose sturgeon with similar and predictable results.
Received July 8, 2011; accepted January 23, 2012
A Single Sea Lamprey Attack Causes Acute Anemia and Mortality in Lake Sturgeon
Authors: Sepúlveda Maria S. , Patrick Holly K. , Sutton Trent M. 
Published: June 2012

Abstract
The effects of sea lamprey Petromyzon marinus parasitism on hematological variables have not been quantified for lake sturgeon Acipenser fulvescens. Our study objectives were to (1) assess changes in lake sturgeon hematology immediately after a single sea lamprey attack and after a 2-week recovery period and (2) assess changes in the histological condition of major hematopoietic organs. Lake sturgeon from four size-groups (470–570, 570–650, 650–760, and 950–1,500 mm fork length) were individually subjected to a sea lamprey attack in a series of 55 experimental trials. Survival of lake sturgeon after a single sea lamprey attack was size dependent, with fish in smaller size-groups exhibiting higher direct and indirect mortality than individuals in larger size-classes. The most sensitive blood chemistry variable was hematocrit: each 1% decline in hematocrit resulted in a 5.1% increase in mortality risk. Other important variables were plasma protein level, with a 10-g/dL decline resulting in a 4.2% increase in mortality risk; and hemoglobin, with a 1-g/dL decline resulting in a 2.9% increase in mortality risk. Most of the surviving lake sturgeon were unable to restore hemoglobin, hematocrit, and plasma protein to pre-attack levels by the end of the 2-week recovery period. We developed an index of histological spleen condition, which indicated that short-duration (&lt;5-d) sea lamprey attachments depleted red blood cell reserves faster than longer-duration attacks. Our study results indicate that sea lamprey parasitism has the potential to induce acute anemia in lake sturgeon and that nonlethal attacks on smaller (&lt;760-mm) fish can have serious physiological implications.
Received August 3, 2011; accepted February 2, 2012.
Association between Vancomycin-Resistant Enterococci Bacteremia and Ceftriaxone Usage
Authors: McKinnell James A. , Kunz Danielle F. , Chamot Eric , Patel Mukesh , Shirley Rhett M. , Moser Stephen A. , Baddley John W. , Pappas Peter G. , Miller Loren G. 
Published: June 2012

Objective.Vancomycin-resistant enterococci (VRE) have become a public health concern with implications for patient mortality and costs. Hospital antibiotic usage may impact VRE incidence, but the relationship is poorly understood. Animal investigations suggest that ceftriaxone may be associated with VRE proliferation. We measured antimicrobial usage and VRE bloodstream infection (VRE-BSI) incidence to test our hypothesis that increased ceftriaxone usage would be associated with a higher incidence of VRE-BSI.Design.Retrospective cohort study.Setting.University of Alabama at Birmingham Medical Center, a 900-bed urban tertiary care hospital.Participants.All patients admitted during the study period contributed data.Methods.We conducted a retrospective analysis of antimicrobial usage and VRE-BSI from 2005 to 2008 (43 months). Antimicrobial usage was quantified as days of therapy (DOTs) per 1,000 patient-days. VRE-BSI incidence was calculated as cases per 1,000 patient-days. Negative binomial regression with adjustment for correlation between consecutive observations was used to measure the association between antimicrobial usage and VRE-BSI incidence at the hospital- and care-unit levels.Results.VRE-BSI incidence increased from 0.06 to 0.17 infections per 1,000 patient-days. Hospital VRE-BSI incidence was associated with prior-month ceftriaxone DOTs (incidence rate ratio, 1.38 per 10 DOTs; P = .005). After controlling for ceftriaxone, prior-month cephalosporin usage (class) was not predictive of VRE-BSI (P = .70). Similarly, prior-month usage of piperacillin-tazobactam, ceftazidime, cefepime, cefazolin, or vancomycin was not predictive of VRE-BSI when considered individually (P ≥ .4 for all comparisons). The final model suggests that type of intensive care unit was related to VRE-BSI incidence.Conclusions.Ceftriaxone usage in the prior month, but not cephalosporin (class) or vancomycin usage, was related to VRE-BSI incidence. These findings suggest that an antimicrobial stewardship program that limits ceftriaxone may reduce nosocomial VRE-BSI incidence.
Serologic Testing for Protection against Hepatitis B Virus Infection among Students at a Health Sciences University in the United States
Authors: Spradling Philip R. , Williams Roxanne E. , Xing Jian , Soyemi Kenneth , Towers Joseph 
Published: June 2012

Objective.To evaluate hepatitis B vaccination coverage and documentation of vaccine-induced immunity.Design.Retrospective cohort analysis.Setting.Graduate school in the United States with programs in osteopathic medicine, dentistry, and allied health.Methods.Data collected included demographics, dates of hepatitis B vaccine doses, and postvaccination concentrations of antibody to hepatitis B surface antigen (anti-HBs), with dates. The proportions of students with anti-HBs of 10 IU/L or more by demographics, age at vaccination, interval since completion of the primary series, and response to additional vaccine doses were compared.Results.Of 3,452 students who matriculated during 2004–2009, 2,643 had complete data; 2,481 (93.9%) received 3 primary doses. Most were women (64.6%), US-born (85.6%), and white (63.2%); median age at receipt of the primary series was 14.5 years (interquartile range, 11.6–20.2 years) and at postvaccination testing was 23.2 years (interquartile range, 22.1–24.8 years). Of those who received 3 primary doses, 2,306 (92.9%) had an anti-HBs postvaccination concentration of 10 IU/L or more. Younger age at vaccination and longer time interval from vaccination to anti-HBs testing were associated with a postvaccination concentration of less than 10 IU/L (P < .001 and P = .0185, respectively, Cochran-Armitage test for trend). Almost all students (98.2%) who initially had less than 10 IU/L of anti-HBs, but then received at least 1 additional dose, had a follow-up anti-HBs concentration of 10 IU/L or more.Conclusions.Almost all students had serologic evidence of protection against hepatitis B virus infection; most were vaccinated as adolescents and were tested more than 10 years after vaccination. Among students with anti-HBs concentrations of less than 10 IU/L, nearly all had 10 IU/L or more after at least 1 additional vaccine dose.
Cluster Randomized Trial to Evaluate the Effect of a Multimodal Hand Hygiene Improvement Strategy in Primary Care
Authors: Martín-Madrazo Carmen , Soto-Díaz Sonia , Cañada-Dorado Asuncion , Salinero-Fort Miguel Angel , Medina-Fernández Manuela , de Santa Pau Enrique Carrillo , Gómez-Campelo Paloma , Abánades-Herranz Juan Carlos 
Published: June 2012

Objective.To evaluate the effectiveness of a multimodal intervention in primary care health professionals for improved compliance with hand hygiene practice, based on the World Health Organization's 5 Moments for Health Hygiene.Design.Cluster randomized trial, parallel 2-group study (intervention and control).Setting.Primary healthcare centers in Madrid, Spain.Participants.Eleven healthcare centers with 198 healthcare workers (general practitioners, nurses, pediatricians, auxiliary nurses, midwives, odontostomatologists, and dental hygienists).Methods.The multimodal hand hygiene improvement strategy consisted of training of healthcare workers by teaching sessions, implementation of hydroalcoholic solutions, and installation of reminder posters. The hand hygiene compliance level was evaluated by observation during regular care activities in the office visit setting, at the baseline moment, and 6 months after the intervention, all by a single external observer.Results.The overall baseline compliance level was 8.1% (95% confidence interval [CI], 6.2-10.1), and the healthcare workers of the intervention group increased their hand hygiene compliance level by 21.6% (95% CI, 13.83-28.48) compared with the control group.Conclusions.This study has demonstrated that hand hygiene compliance in primary healthcare workers can be improved with a multimodal hand hygiene improvement strategy.
Monitoring Hand Hygiene via Human Observers: How Should We Be Sampling?
Authors: Fries Jason , Segre Alberto M. , Thomas Geb , Herman Ted , Ellingson Katherine , Polgreen Philip M. 
Published: June 2012

Objective.To explore how hand hygiene observer scheduling influences the number of events and unique individuals observed.Design.We deployed a mobile sensor network to capture detailed movement data for 6 categories of healthcare workers over a 2-week period.Setting.University of Iowa Hospital and Clinic medical intensive care unit (ICU).Methods.We recorded 33,721 time-stamped healthcare worker entries to and exits from patient rooms and considered each entry or exit to be an opportunity for hand hygiene. Architectural drawings were used to derive 4 optimal line-of-sight placements for observers. We ran simulations for different observer movement schedules, all with a budget of 1 hour of total observation time. We considered observation times of 1–15, 15–30, 30, and 60 minutes per station. We stochastically generated healthcare worker hand hygiene compliance on the basis of all data and recorded the total unit compliance as it would be reported by each simulated observer.Results.Considering a 60-minute total observation period, aggregate simulated observers captured 1.7% of the average total number of opportunities per day at best and 0.5% at worst. The 1–15-minute schedule captures, on average, 16% fewer events than does the 60-minute (ie, static) schedule, but it samples 17% more unique individuals. The 1–15-minute schedule also provides the best estimator of compliance for the duration of the shift, with a mean standard deviation of 17%, compared with 23% for the 60-minute schedule.Conclusions.Our results show that observations are sensitive to different observers' schedules and suggest the importance of using data-driven approaches to schedule hand hygiene audits.
On the generalized Benjamin-Ono equation
Authors: Kenig Carlos E. , Ponce Gustavo , Vega Luis 
Published: June 2012

We study well-posedness of the initial value problem for the generalized Benjamin-Ono equation∂tu+uk∂xu−∂xDxu=0{\partial _t}u + {u^k}{\partial _x}u - {\partial _x}{D_x}u = 0,k∈Z+k \in {\mathbb {Z}^ + }, in Sobolev spacesHs(R){H^s}(\mathbb {R}). For small data and higher nonlinearities(k≥2)(k \geq 2)new local and global (including scattering) results are established. Our method of proof is quite general. It combines several estimates concerning the associated linear problem with the contraction principle. Hence it applies to other dispersive models. In particular, it allows us to extend the results for the generalized Benjamin-Ono to nonlinear Schrödinger equations (or systems) of the form∂tu−i∂x2u+P(u,∂xu,u¯,∂xu¯)=0{\partial _t}u - i\partial _x^2u + P(u,{\partial _x}u,\bar u,{\partial _x}\bar u) = 0.
Infinite families of isomorphic nonconjugate finitely generated subgroups
Authors: Johnson F. E. A. 
Published: June 2012

Let

⟨

,

⟩
:
L
×
L
→

Z

\langle \;,\;\rangle :L \times L \to \mathbb {Z}

be a nondegenerate symmetric bilinear form on a finitely generated free abelian group L which splits as an orthogonal direct sum

(
L
,

⟨

,

⟩
)
≅
(

L
1

,

⟨

,

⟩
)
⊥
(

L
2

,

⟨

,

⟩
)
⊥
(

L
3

,

⟨

,

⟩
)

(L,\;\langle \;,\;\rangle ) \cong ({L_1},\;\langle \;,\;\rangle ) \bot ({L_2},\;\langle \;,\;\rangle ) \bot ({L_3},\;\langle \;,\;\rangle )

in which

(

L
1

,

⟨

,

⟩
)

({L_1},\;\langle \;,\;\rangle )

has signature (2, 1),

(

L
2

,

⟨

,

⟩
)

({L_2},\;\langle \;,\;\rangle )

has signature (n, 1) with

n
≥
2

n \geq 2

, and

(

L
3

,

⟨

,

⟩
)

({L_3},\;\langle \;,\;\rangle )

is either zero or indefinite with

rk

Z

(

L
3

)
≥
3

{\text {rk}}_\mathbb {Z}({L_3}) \geq 3

. We show that the integral automorphism group

Aut

Z

(
L
,

⟨

,

⟩
)

{\operatorname {Aut} _\mathbb {Z}}(L,\;\langle \;,\;\rangle )

contains an infinite family of mutually isomorphic finitely generated subgroups

(

Γ
σ

)

σ
∈
Σ

{({\Gamma _\sigma })_{\sigma \in \Sigma }}

, no two of which are conjugate. In the simplest case, when

L
3

=
0

{L_3} = 0

, the groups

Γ
σ

{\Gamma _\sigma }

are all normal subdirect products in a product of free groups or surface groups. The result can be seen as a failure of the rigidity property for subgroups of infinite covolume within the corresponding Lie group

Aut

Z

(
L

⊗

Z

R

,

⟨

,

⟩
⊗
1
)

{\operatorname {Aut} _\mathbb {Z}}(L{ \otimes _\mathbb {Z}}\mathbb {R},\;\langle \;,\;\rangle \otimes 1)

.
Climate-related variations in the occurrence and distribution of mackerel (Scomber scombrus) in Icelandic waters
Authors: Astthorsson Olafur S. , Valdimarsson Héðinn , Gudmundsdottir Asta , Óskarsson Guðmundur J. 
Published: June 2012

Abstract
Astthorsson, O. S., Valdimarsson, H., Gudmundsdottir, A., and Óskarsson, G. J. 2012. Climate-related variations in the occurrence and distribution of mackerel (Scomber scombrus) in Icelandic waters. – ICES Journal of Marine Science, 69: . Based on long-term investigations on sea temperature in Icelandic waters, five climatic periods are defined from the mid-1880s until today. These are a cold period between 1880 and 1920, a warm period between 1921 and 1964, a cold period between 1965 and 1971, one of intermediate conditions (alternating warm and cold) between 1972 and 1995, and finally a warm period from 1996 until today. Mackerel were first reported from Icelandic waters in 1895, were then found intermittently until 1996, and from then appeared almost every year and since 2007 in large numbers in many areas around Iceland. The occurrence of mackerel appears to be confined mainly to warm periods in the North Atlantic Ocean and around Iceland. The unprecedented occurrence and extended distribution of the species began at the onset of the recent warm period during the mid-1990s and, in recent years, 0-group and age 1 mackerel have also been observed in Icelandic waters. This expansion in distribution resulted initially in a bycatch fishery, which then developed into a direct fishery within the Icelandic Exclusive Economic Zone, increasing from ∼1700 t in 2006 to ∼120 000 t in 2009 and 2010.
Impact of rituximab on treatment outcomes of patients with diffuse large b‐cell lymphoma: a population‐based analysis
Authors: Lee Linda , Crump Michael , Khor Sara , Hoch Jeffrey S. , Luo Jin , Bremner Karen , Krahn Murray , Hodgson David C. 
Published: June 2012

SummaryWe conducted a multi‐institutional population‐based analysis of the survival and toxicity associated with the addition of rituximab to chemotherapy for patients with diffuse large B‐cell lymphoma (DLBCL), including patients aged ≥80 years, who were excluded from published randomized trials. Using population‐based registries in Ontario, we identified 4021 patients who received chemotherapy with or without rituximab (R‐CHOP [rituximab with cyclophosphamide, doxorubicin, vincristine and prednisone] or CHOP) for DLBCL between 1996 and 2007, including 397 patients aged ≥80 years. After propensity score matching, the overall survival (OS) and significant toxicities for R‐CHOP and CHOP treatment groups were compared. R‐CHOP was associated with a significant increase in 5‐year OS compared to CHOP alone (62% vs. 54%; hazard of death = 0·78, P = 0·0004). Survival benefit was seen in all age groups, including those aged ≥80 years. Patients treated with rituximab did not have a significant increase in 1‐year hospitalization rates for cardiac, pulmonary, gastrointestinal or neurological diagnoses compared to those treated with CHOP alone. The addition of rituximab to CHOP improves survival in the general population of patients with DLBCL and produces early survival benefit for very elderly patients, without any significant increase in the risk of serious toxicity.
Surviving, not thriving: a qualitative study of newly qualified midwives’ experience of their transition to practice
Authors: Fenwick Jennifer , Hammond Athena , Raymond Jane , Smith Rachel , Gray Joanne , Foureur Maralyn , Homer Caroline , Symon Andrew 
Published: June 2012

Aim and objectives.  The study explored the experiences of newly qualified midwives and described the factors that facilitated or constrained their development during the transition from student to registered midwife.Background.  Knowledge of the transition to midwifery practice remains limited.Design and Method.  A qualitative descriptive approach was used. Sixteen graduates from one Australian University participated in a tape‐recorded interview. Thematic analysis was used to analyse the data set.Results.  The metaphor of ‘The Pond’, an environment that consists of layers of life and can be both clear and peaceful or murky and infested, was used to describe new midwives perceptions of the context and culture of hospital‐based maternity care. For some, ‘The Pond’ was a harsh environment that often became toxic. The ‘Life‐raft’ metaphor was used to describe the importance of midwife‐to‐midwife relationships. The theme of ‘Swimming’ captured the consequence of positive interactions with colleagues and a supportive environment, whilst ‘Sinking’ described the consequence of poor relationships with midwives and a difficult working environment.Conclusion.  The study highlights the importance of positive midwife‐to‐midwife relationships on the transition from student to registered midwife. There was also evidence that continuity with women and midwifery colleagues enhanced confidence and restored faith in normal birth. At the same time, it was clear that the midwifery culture of some institutions remains highly contested with midwives struggling to provide woman‐centred care and often challenged by the risk‐averse nature of maternity care.Relevance to Clinical Practice.  Whilst further work is required, the findings provide a deeper understanding of individual midwives’ transition period. The importance of forming longitudinal relationships not only with women but with midwifery colleagues is highlighted. Developing continuity models that adequately support graduates and student’s needs are likely to assist in addressing practices issues in both the academic and clinical setting.