bluuebunny/crossref_metadata_2025 huggingface dataset:
Beaver assisted river valley formation
Authors: Westbrook C. J. , Cooper D. J. , Baker B. W.
Published: January 2010

We examined how beaver dams affect key ecosystem processes, including pattern and process of sediment deposition, the composition and spatial pattern of vegetation, and nutrient loading and processing. We provide new evidence for the formation of heterogeneous beaver meadows on riverine system floodplains and terraces where dynamic flows are capable of breaching in‐channel beaver dams. Our data show a 1.7‐m high beaver dam triggered overbank flooding that drowned vegetation in areas deeply flooded, deposited nutrient‐rich sediment in a spatially heterogeneous pattern on the floodplain and terrace, and scoured soils in other areas. The site quickly de‐watered following the dam breach by high stream flows, protecting the deposited sediment from future re‐mobilization by overbank floods. Bare sediment either exposed by scouring or deposited by the beaver flood was quickly colonized by a spatially heterogeneous plant community, forming a beaver meadow. Many willow and some aspen seedlings established in the more heavily disturbed areas, suggesting the site may succeed to a willow carr plant community suitable for future beaver re‐occupation. We expand existing theory beyond the beaver pond to include terraces within valleys. This more fully explains how beavers can help drive the formation of alluvial valleys and their complex vegetation patterns as was first postulated by Ruedemann and Schoonmaker in 1938. Copyright © 2010 John Wiley & Sons, Ltd.
Online calculators of ecological footprint: do they promote or dissuade sustainable behaviour?
Authors: Franz Jennifer , Papyrakis Elissaios
Published: January 2010

Ecological footprint (EF) indices estimate the impact of an individual's lifestyle on the planet by converting levels of consumption into the amount of land needed to sustain production levels and lifestyle choices. Several popular organizations (e.g. WWF, Global Footprint Network) now offer personalized EF calculators to help inform consumers of the impacts of their personal consumption habits. In this paper, we evaluate the most popular online EF calculators and find that, even when the most environmentally friendly options are adopted, for the majority of available indices, one still exceeds the planet's biocapacity levels. The absence of options to fully offset one's environmental impacts implicitly suggests that there is no truly sustainable level of consumption at current population levels, even under the most prudent consumer choices. Although all online EF calculators claim to be a tool for education to promote sustainable behaviour, their calculations suggest, to the contrary, that as consumers we may postpone but not necessarily prevent environmental catastrophes. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Attacks on a lightweight cipher based on a multiple recursive generator
Authors: Xiao Lu , Rose Gregory G.
Published: January 2010

At IEEE GLOBECOM 2008, a lightweight cipher based on a Multiple Recursive Generator (MRG) was proposed for use in resource limited environment such as sensor nodes and RFID tags. This paper proposes two efficient attacks on this MRG cipher. A distinguishing attack is firstly introduced to identify the use of an MRG cipher that has a modulus suggested by its designers. It requires 218 words of ciphertext and the most significant bit of each corresponding plaintext word. Then an efficient known plaintext attack is proposed to construct the cipher's current state and generate subkeys used for all subsequent encryption. The known plaintext attack, when targeted at the MRG ciphers optimized for efficiency, only requires 2k words of known plaintext and trivial computation where k is the MRG order. Even the ciphers based on complicated and inefficient MRGs can be attacked with low complexity, e.g. in the magnitude of 212 words of known plaintext for all MRG ciphers with order 47, regardless of which MRG modulus is used. These two attacks indicate that the examined MRG cipher structure is seriously flawed. Copyright © 2010 John Wiley & Sons, Ltd.
Corrosion fatigue on 2024T3 and 6056T4 aluminum alloys
Authors: Scala A. , Squillace A. , Monetta T. , Mitton D. B. , Larson D. , Bellucci F.
Published: January 2010

Fatigue corrosion phenomenon is a form of degradation that is because of the combined occurrence of a mechanical cyclical stress and a corrosive environment. Fatigue corrosion can be an issue in commercial and military aircraft, and has the potential to affect the structural integrity and the useful life of an aerostructure. Although the distinct consequences of both fatigue and corrosion have been extensively documented for aluminum alloys, their synergistic action is not completely understood and continues to be an area of considerable scientific and industrial interest. In this paper, a novel approach is proposed and applied for monitoring the electrochemical behavior of different types of aluminum alloy samples while they are subjected to fatigue loading. Cyclic load experiments were conducted on bare 2024T3 and 6056T4 aluminum alloy samples in the presence of an aggressive aerated solution of 3.5% NaCl over a range of frequencies. The R‐ratio was 0. Two different aluminum alloys have been tested in both high‐ and low‐cycle fatigue. In the former case, the maximum stress experienced by the specimen is lower than the material yield strength, which means that the average expected number of cycles to failure is high; in the latter case, the maximum stress experienced by the specimen during the test is higher than the material yield strength, which means that the average expected number of cycles to failure is low. The open circuit potential(OCP) was monitored versus time during the tests described above. The observed OCP variations are interpreted as the occurrence of corrosion during crack initiation and propagation at the air formed oxide/solution interface film. As expected, there is a more pronounced influence of corrosion at lower fatigue frequencies. Crack propagation allows bulk material to be progressively more exposed to the aggressive environment, which stimulates accelerated crack propagation, resulting in a lower fatigue resistance. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of low‐cycle fatigue on a 10‐storey steel building
Authors: Nastar Navid , Anderson James C. , Brandow Gregg E. , Nigbor Robert L.
Published: January 2010

Following the Northridge Earthquake in 1994, the SAC project was initiated as a joint venture between Structural Engineers Association of California (SEAOC), Applied Technology Council (ATC), and Consortium of Universities for Research in Earthquake engineering (CUREe) to investigate the causes of widespread damage observed in the connections of steel moment frame buildings. The published results of these studies concentrated on local connection defects that potentially initiated the observed cracks. It was also considered that much of the observed connection damage was the result of yielding of the material in the connection region and the formation of plastic hinges. However, damage to some buildings could not be reconciled by the use of these failure mechanisms. This has led to a renewed interest in the effects of low‐cycle fatigue on the members and connections in steel buildings that are either elastic or have been driven into the weakly nonlinear range.

The current paper is focused on the effect of low‐cycle fatigue in the connection damage observed in a 10‐storey steel building following the Northridge Earthquake. A comprehensive fatigue analysis procedure is developed based on the Palmgren–Miner method and S–N curves established for the high‐cycle fatigue range are extended to the low‐cycle region using the limited test results that are available. Fatigue analysis is performed at critical locations of a representative moment frame using the established procedure. Finally, the pattern of cumulative fatigue at critical connections and the observed damage are compared. Results of this analytical study indicate that the effect of low‐cycle fatigue may be significant in evaluating and predicting various types of connection damage similar to that observed in the steel moment frames following the Northridge Earthquake. Copyright © 2010 John Wiley & Sons, Ltd.
Screening fetal echocardiography in diabetic mothers with normal findings on detailed anatomic survey
Authors: Sekhavat S. , Kishore N. , Levine J. C.
Published: January 2010

Objectives

To evaluate the benefit of second‐trimester fetal echocardiography for women with diabetes whose fetuses had no obvious heart disease on a detailed anatomic survey performed at skilled, high‐volume obstetric centers, and to investigate the technical limitations of fetal echocardiography in this patient population.

Methods

This was a retrospective descriptive review of fetal echocardiograms performed at Children's Hospital Boston from 2000 to 2005. All women referred during the second trimester for fetal echocardiography because of maternal diabetes were included. Those with severe heart disease suspected on obstetric ultrasound examination were excluded.

Results

There were 584 initial fetal echocardiograms. No patients were diagnosed with severe heart disease prenatally. Nineteen were diagnosed with suspected mild heart disease (such as small ventricular septal defect), five of whom had normal follow‐up fetal evaluation and five of whom had normal postnatal evaluation. Most of these pregnancies did not have a postnatal cardiac evaluation. Forty‐seven fetuses had benign cardiac findings. Nearly one third of patients had imaging that was felt to be limited or incomplete, mostly due to poor acoustic windows. Forty‐eight patients were asked to return for at least one follow‐up visit, most due to the inability to complete the exam at the initial visit.

Conclusions

In an environment with access to high‐volume, skilled comprehensive ultrasound services, fetal echocardiography by a pediatric cardiology program adds little to the care of women with diabetes and no suspected heart disease on a detailed anatomic survey. Poor acoustic windows frequently necessitate multiple visits. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Plasma soluble endoglin concentration in pre‐eclampsia is associated with an increased impedance to flow in the maternal and fetal circulations
Authors: Chaiworapongsa T. , Romero R. , Kusanovic J. P. , Mittal P. , Kim S. K. , Gotsch F. , Than N. G. , Mazaki‐Tovi S. , Vaisbuch E. , Erez O. , Yeo L. , Hassan S. S. , Sorokin Y.
Published: January 2010

Objectives

To examine the relationship between abnormalities in uterine (UtA) and/or umbilical artery (UA) Doppler velocimetry and maternal plasma concentrations of soluble endoglin (sEng) in patients with pre‐eclampsia (PE).

Methods

A cross‐sectional study was conducted in 135 normal pregnant women and 69 patients with PE. Patients with PE were subclassified into four groups: those who had Doppler abnormalities in both the UtA and UA, patients who had Doppler abnormalities in the UtA alone, those who had Doppler abnormalities in the UA alone, and patients without Doppler abnormalities in either vessel. Plasma concentrations of sEng were determined by enzyme‐linked immunosorbent assay.

Results

Among patients with PE, those with abnormal UtA and UA Doppler velocimetry had the highest median plasma concentration of sEng compared with any other group (P < 0.001, Kruskal–Wallis test). Women with PE with normal Doppler velocimetry in both vessels had the lowest median plasma concentration of sEng. There was a significant relationship between plasma concentrations of sEng and mean UtA resistance index (Spearman Rho = 0.5, P < 0.001) as well as UA pulsatility index (Spearman Rho = 0.4, P = 0.002). Multiple regression analysis suggested that Doppler abnormalities in the UtA and UA as well as gestational age at blood sampling contributed to plasma sEng concentrations (P < 0.001).

Conclusions

Abnormalities of impedance to blood flow in the UtA and UA are associated with an excess of sEng in the circulation of mothers with PE. These findings suggest that the ‘antiangiogenic state’ in PE is partially reflected in abnormalities of Doppler velocimetry. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal diagnosis of tricuspid atresia: intrauterine course and outcome
Authors: Berg C. , Lachmann R. , Kaiser C. , Kozlowski P. , Stressig R. , Schneider M. , Asfour B. , Herberg U. , Breuer J. , Gembruch U. , Geipel A.
Published: January 2010

Objective

To evaluate the intrauterine course and outcome of tricuspid atresia detected in the fetus.

Methods

This was a retrospective review of all confirmed cases of tricuspid atresia detected prenatally between 1998 and 2006 in three tertiary referral centers in Germany.

Results

Fifty‐four cases of tricuspid atresia were detected prenatally during the study period and confirmed postnatally: 28 (51.9%) cases had a concordant ventriculoarterial connection of which 14 also had pulmonary outflow obstruction; 25 (46.3%) cases had a discordant ventriculoarterial connection of which 14 also had aortic outflow obstruction, six had pulmonary outflow tract obstruction and two had other associated intracardiac anomalies; and one (1.9%) had a common arterial trunk. The peak velocity index for veins in the ductus venosus was significantly elevated in 19 of the 37 (51.4%) cases assessed; however, this finding did not correlate with adverse intrauterine outcome. There were associated extracardiac anomalies in 12 cases: five with chromosomal anomalies, two with VACTERL association, one with unilateral renal agenesis, one with hypospadia, one with hydrothorax, one with megacystis and one with agenesis of the ductus venosus. Seventeen of the 54 (31.5%) cases underwent termination of pregnancy, two (3.7%) died in utero, two (3.7%) died in infancy and 33 (61.1%) children survived with a median follow‐up of 26 (range, 12–120) months. Prenatal echocardiography correctly anticipated the postnatal course and the need for neonatal intervention in 29/35 (82.9%) continued pregnancies; in the remaining six (17.1%) cases the right outflow tract obstruction had been underestimated.

Conclusions

Tricuspid atresia and the frequently associated intracardiac anomalies can be diagnosed in the fetus with considerable accuracy. A thorough search for extracardiac malformations should be performed in order to rule out chromosomal anomalies and multiple malformation syndromes. Elevated pulsatility in the ductus venosus does not indicate cardiac failure. The short‐term overall survival in continued pregnancies in our study exceeded 89%, with the greatest rate of loss being in the first year of postnatal life. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Sonographic assessment of fetal spine and head position during the first and second stages of labor for the diagnosis of persistent occiput posterior position: a pilot study
Authors: Blasi I. , D'Amico R. , Fenu V. , Volpe A. , Fuchs I. , Henrich W. , Mazza V.
Published: January 2010

Objectives

The aim of this pilot study was to perform a preliminary investigation into the predictive values of the position of the fetal spine and of the occiput measured during the first and second stages of labor by intrapartum ultrasound for persistent occiput posterior (OP) position.

Methods

This was a prospective, cohort study, in which 100 women with singleton pregnancies were enrolled during the first or second stage of labor. The women underwent intrapartum transabdominal sonography and the positions of the fetal head and spine were recorded. The women were followed up until delivery and occiput position at birth was assessed.

Results

Eighty‐four pregnancies were evaluated in the second stage of labor, with 74 of these also evaluated in the first stage. Fifty‐one percent of fetuses were found to be in an OP position during the first stage of labor, but the majority of these rotated to an anterior position before delivery. There were six cases of OP at delivery, and all of these were among the 23 fetuses that were found to be in an OP position on ultrasound evaluation during the second stage of labor. All six were also found to have a posterior spine position during the second stage of labor, with this finding observed in only one fetus with occiput anterior position at delivery.

Conclusions

The results of this study suggest that the position of the head and spine during the second stage of labor could be useful indicators for predicting the OP position at delivery. The results also suggest that the OP position at delivery results from a failure of rotation from the OP position, rather than a malrotation from the anterior position. Studies with larger sample sizes are needed to confirm these results. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
High‐resolution light microscopy using luminescent nanoparticles
Authors: Ohulchanskyy Tymish Y. , Roy Indrajit , Yong Ken‐Tye , Pudavar Haridas E. , Prasad Paras N.
Published: January 2010

This review presents recent progress in the development of the luminescent nanoparticles for confocal and multiphoton microscopy. Four classes of nanomaterials are discussed: (1) silica‐based nanoparticles doped with fluorescent molecules, (2) gold nanoparticles, (3) semiconductor nanocrystals (quantum dots/rods), and (4) nanophosphors. Special considerations are given to recently developed imaging nanoprobes, such as (1) organically modified silica (ORMOSIL) nanoparticles doped with two‐photon absorbing fluorophores, which exhibit aggregation‐enhanced fluorescence (AEF), and (2) nanophosphors (ceramic nanoparticles containing luminescent lanthanoid ions). Advantages and disadvantages of every class of nanomaterials and their specific applications are briefly discussed. WIREs Nanomed Nanobiotechnol 2010 2 162–175

This article is categorized under:

Diagnostic Tools > Biosensing

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
Axon repair: surgical application at a subcellular scale
Authors: Chang Wesley C. , Hawkes Elizabeth , Keller Christopher G. , Sretavan David W.
Published: January 2010

Injury to the nervous system is a common occurrence after trauma. Severe cases of injury exact a tremendous personal cost and place a significant healthcare burden on society. Unlike some tissues in the body that exhibit self healing, nerve cells that are injured, particularly those in the brain and spinal cord, are incapable of regenerating circuits by themselves to restore neurological function. In recent years, researchers have begun to explore whether micro/nanoscale tools and materials can be used to address this major challenge in neuromedicine. Efforts in this area have proceeded along two lines. One is the development of new nanoscale tissue scaffold materials to act as conduits and stimulate axon regeneration. The other is the use of novel cellular‐scale surgical micro/nanodevices designed to perform surgical microsplicing and the functional repair of severed axons. We discuss results generated by these two approaches and hurdles confronting both strategies. WIREs Nanomed Nanobiotechnol 2010 2 151–161

This article is categorized under:

Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease

Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement

Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery
Comparisons of ancient mortars and hydraulic cements through in situ analyses by portable X‐ray fluorescence spectrometry
Authors: Donais Mary Kate , Duncan Bradley , George David , Bizzarri Claudio
Published: January 2010

A portable X‐ray fluorescence spectrometer was used to collect elemental data on various mortars and hydraulic cements at an excavation site near Orvieto, Italy. Four cases are presented that use X‐ray fluorescence data to differentiate among mortars: (1) comparison of two mortars on one locus; (2) comparison of two layers of hydraulic cement on one locus; (3) comparison of two hydraulic cement floors; (4) comparison among mortars on five walls from four trenches. The conclusions made from the comparisons aided the site archaeologists in their assessment of the relationships of various loci at the site and establishment of phasing. Elements found in measureable amounts in the mortars and hydraulic cements were Ca, Ti, Mn, Fe, Zn, As, Rb, Sr, Zr, Pb, and Bi. Elements found to be different in the samples and used to differentiate among mortars were Ca, Fe, Zn, Pb, Zr, and Rb. Graphical and statistical data evaluations are presented. Copyright © 2010 John Wiley & Sons, Ltd.
Damage of nonlinearly elastic materials at small strain – Existence and regularity results –
Authors: Thomas M. , Mielke A.
Published: January 2010

This paper discusses an existence result for energetic solutions of rate‐independent damage processes and the temporal regularity of the solution. We consider a body consisting of a physically nonlinearly elastic material undergoing small deformations and partial damage. The present work is a generalization of [16] concerning the properties of the stored elastic energy density as well as the suitable Sobolev space for the damage variable: While previous work assumes that the damage variable z satisfies z in W1, r(Ω) with r > d for Ω ⊂ ℝd, we can handle the case r > 1 by a new technique for the construction of joint recovery sequences. Moreover, this work generalizes the temporal regularity results to physically nonlinearly elastic materials by analyzing Lipschitz‐ and Hölder‐continuity of solutions with respect to time.
A preliminary study of orbitofrontal activation and hypersociability in Williams Syndrome
Authors: Mimura Masaru , Hoeft Fumiko , Kato Motoichiro , Kobayashi Nobuhisa , Sheau Kristen , Piggot Judith , Mills Debra , Galaburda Albert , Korenberg Julie R. , Bellugi Ursula , Reiss Allan L.
Published: January 2010

Individuals with Williams syndrome (WS) demonstrate an abnormally positive social bias. However, the neural substrates of this hypersociability, i.e., positive attribution bias and increased drive toward social interaction, have not fully been elucidated. Methods: We performed an event-related functional magnetic resonance imaging study while individuals with WS and typically developing controls (TD) matched positive and negative emotional faces. WS compared to TD showed reduced right amygdala activation during presentation of negative faces, as in the previous literature. In addition, WS showed a unique pattern of right orbitofrontal cortex activation. While TD showed medial orbitofrontal cortex activation in response to positive, and lateral orbitofrontal cortex activation to negative, WS showed the opposite pattern. In light of the general notion of a medial/lateral gradient of reward/punishment processing in the orbitofrontal cortex, these findings provide an additional biological explanation for, or correlate of positive attribution bias and hypersociability in WS.
Biocatalytic Properties of Lipase from Walnut Seed (Juglans regia L.)
Authors: Yeşiloğlu Yeşim , Demirkan Bora
Published: January 2010

Lipase (E.C. 3.1.1.3) from walnut seed was purified 28.6‐fold with 31% yield using Sephadex G‐100 gel chromatography. Olive oil served as good substrate for the enzyme. The optimum pH and temperature were 9.0 and 70 °C, respectively. The lipase was stable between 30 and 80 °C for 5 min. Km and Vmax values were determined as 48 mM and 23.06 × 10−3 U/min mg for triolein as substrate. Lipase activity was slightly reduced by Cu2+, Ca2+, Hg2+, Mn2+, and Ni2+ ions, while Mg2+ and Zn2+ had no effects. Anionic surfactant sodium dodecyl sulfate stimulated lipase activity while non‐ionic surfactants Tween‐80 and Triton X‐100 had negligible effects on enzymatic activity. The enzyme activity was not affected by 50 mM urea and thioacetamide. Potassium ferricyanide, n‐bromosuccinamide and potassium cyanide reduced the enzyme activity. The enzyme showed a good stability in organic solvents, the best result being in n‐hexane (113% residual activity). The activity of dialysate was maintained approximately 80% for 1 year at −20 °C.
Adjustment of female adolescents leaving home for the military: Links with earlier individuation
Authors: Sher‐Censor Efrat , Oppenheim David
Published: January 2010

The study examined the associations between female adolescents' individuation during mid‐adolescence and their adjustment two years later to leaving home for mandatory military service. Forty nine daughter–mother dyads participated. Individuality and connectedness during adolescent–mother interactions were observed at age 16. Two years later girls reported on their psychological distress and negative expectations regarding the upcoming conscription, and both daughters and mothers reported on maternal support of daughters' autonomy. Controlling for these concurrent perceptions, girls' higher connectedness was associated with less psychological distress and their higher individuality in the context of low to medium connectedness was related to more negative expectations. These findings contribute to the literature on home leaving by showing that early individuation may play a role in female adolescents' adjustment to this transition.
Autophagy in cellular growth control
Authors: Wang Richard C. , Levine Beth
Published: January 2010

Cell growth is regulated by two antagonistic processes: TOR signaling and autophagy. These processes integrate signals including growth factors, amino acids, and energy status to ensure that cell growth is appropriate to environmental conditions. Autophagy responds indirectly to the cellular milieu as a downstream inhibitory target of TOR signaling and is also directly controlled by nutrient availability, cellular energy status, and cell stress. The control of cell growth by TOR signaling and autophagy are relevant to disease, as altered regulation of either pathway results in tumorigenesis. Here we give an overview of how TOR signaling and autophagy integrate nutritional status to regulate cell growth, how these pathways are coordinately regulated, and how dysfunction of this regulation might result in tumorigenesis.
Viability and functional capacity after thawing of hematopoietic progenitor cells cryopreserved at a cord blood stem cell bank in Colombia
Authors: Ávila Portillo Luz Mabel , Guzmán Juliana , Rojas Carolina , Becerra Andrea , Avila Jennifer , Jaimes Diego , Ospino Benjamín , Gomez Claudia , Madero José Ignacio
Published: January 2010

Objective

To evaluate the viability and functional capacity of hematopoietic progenitor cells from cord blood samples cryopreserved at the Banco de Células Stem de Colombia.

Methods

After thawing and centrifugation of 20 samples, viable white blood cells were numbered by the trypan blue method and CD34+CD45+ dim hematopoietic progenitor cells were numbered by flow cytometry. Clonogenic assays also tested the functional capacity of viable CD34+CD45+ dim cells.

Results

The median rates of viable CD34+CD45+ dim cells were 99.6% before freezing and 73.0% after thawing (P < 0.001). The 20 cultures yielded a median of 12 cells with a lineage of red cells, 17.5 cells with a lineage of white cells, and 10 cells with a mixed lineage.

Conclusion

Although the rate of viable CD34+CD45+ dim cells was decreased by 26.6% after thawing by the method we used, the numbers of CD34+CD45+ dim cells that formed colonies were similar to those obtained by other published methods.
Factors associated with operative hysteroscopy outcome in patients with uterine adhesions or submucosal myomas
Authors: Chang Cherry Yin‐Yi , Chang Yung‐Tsang , Chien Shu‐Chin , Yu Shyr‐Shen , Hung Yao‐Ching , Lin Wu‐Chou
Published: January 2010

Objective

To determine the factors associated with hysteroscopic surgery long‐term outcome in patients with intrauterine adhesions or submucosal myomas.

Methods

Factors thought to be associated with outcome were retrospectively evaluated from the records of 591 patients who were followed up for at least 5 years after undergoing hysteroscopic adhesiolysis (n = 203) or myomectomy (n = 388).

Results

The major factors affecting outcome were degree of adhesion (OR, 1.91; P = 0.03) in the former group and parity (OR, 0.55; P = 0.005) and depth of intramural penetration of the myoma (OR, 30.74; P < 0.001) in the latter. Severe intrauterine adhesion, low parity, and deep intramural penetration of submucosal myoma had an associated increase risk of poor outcome. The overall complication rate was 1.35% and, respectively, 12.8% and 9.3% of the patients who underwent hysteroscopic adhesiolysis or myomectomy needed a second intervention.

Conclusion

Hysteroscopic surgery is a safe and effective procedure. Degree of adhesion or parity and depth of intramural penetration of myomas are the major factors affecting outcome in patients with these lesions.
Perioperative course and medium‐term outcome of the transobturator and infracoccygeal hammock for posthysterectomy vaginal vault prolapse
Authors: Sergent Fabrice , Zanati Joël , Bisson Violène , Desilles Nicolas , Resch Benoît , Marpeau Loïc
Published: January 2010

Objective

To describe the perioperative course and medium‐term anatomic and functional outcomes of the transobturator–infracoccygeal hammock for posthysterectomy vaginal vault prolapse repair.

Methods

A prospective consecutive series of 52 women with a stage 2 vaginal vault prolapse or higher that occurred after total hysterectomy who underwent surgery between 2003 and 2007. Principal outcome measures were anatomic cure (stage 1 or lower) and impact on quality of life measured using the pelvic floor distress inventory (PFDI) and pelvic floor impact self‐reported questionnaire (PFIQ). Anatomical results were analyzed using χ2 and Fisher exact tests, and PFDI and PFIQ scores were analyzed using the Wilcoxon test.

Results

With a median follow‐up of 36 months, the anatomic cure rate was 96%. Significant improvements were noted in POPQ‐S scores after surgery (P < 0.05). Stress urinary incontinence was cured in 73% of patients and improved in 15% of patients. The PFDI and PFIQ scores were improved (P < 0.05). One mesh extrusion was observed. The rates of mesh contraction and new cases of dyspareunia were 31% and 13%, respectively.

Conclusion

The transvaginal mesh hammock represents a useful treatment for recurrent and major vaginal vault prolapse, and has few complications.
Transfusion criteria in free flap surgery
Authors: Rossmiller Sarah R. , Cannady Steven B. , Ghanem Tamer A. , Wax Mark K.
Published: January 2010

Objective

The ideal hematocrit for patients undergoing free flap reconstruction is unknown. It is standard practice to keep hematocrit levels above 30 percent, although there is evidence that blood transfusions are associated with both infectious and noninfectious complications. We propose that lowering the trigger for postoperative transfusions from 30 percent to 25 percent will not increase flap‐related complications and may reduce unnecessary blood transfusions.

Study Design

Observational cohort study.

Setting

Tertiary care center.

Subjects and Methods

Patients undergoing free tissue transfer from January 2007 through February 2008 received blood transfusions for hematocrit < 30 percent, whereas patients having surgery from March 2008 through April 2009 received blood transfusions for hematocrit < 25 percent. Outcomes include flap‐related complications, length of stay, number of units transfused, and lowest postoperative hematocrit.

Results

In the group transfused for hematocrit < 30 percent, 123 patients underwent 129 free flaps. In the group transfused for hematocrit < 25 percent, 122 patients underwent 135 flaps. The mean lowest postoperative hematocrit levels were significantly lower in the group transfused for hematocrit < 25 percent compared with the group transfused for hematocrit < 30 percent (26.6% vs 28.4%, respectively, P < 0.0001). The group with hematocrit < 25 percent also received fewer units of blood transfused (1.47 vs 2.11, P = 0.028). Complication rates between the two groups were not significantly different aside from higher rates of fistula and respiratory failure in the group transfused for hematocrit < 30 percent. Flap loss was 2.3 percent compared with 6.7 percent (P = 0.138).

Conclusion

For patients undergoing free flap surgery, a postoperative transfusion trigger of hematocrit < 25 percent decreases blood transfusion rates without increasing rates of flap‐related complications.
Interaction between gravitational waves and plasma waves in the Vlasov description
Authors: BRODIN G. , FORSBERG M. , MARKLUND M. , ERIKSSON D.
Published: January 2010

The nonlinear interaction between electromagnetic, electrostatic and gravitational waves in a Vlasov plasma is reconsidered. By using a orthonormal tetrad description the three-wave coupling coefficients are computed. Comparing with previous results, it is found that the present theory leads to algebraic expression that are much reduced, as compared to those computed using a coordinate frame formalism. Furthermore, here we calculate the back reaction on the gravitational waves, and a simple energy conservation law is deduced in the limit of a cold plasma.
Magnetized plasma-wall transition layer with cold ions
Authors: TSKHAKAYA D. D. , BINT-E-MUNIR F. , KUHN S.
Published: January 2010

The magnetized plasma-wall transition (MPWT) layer occurring, for example near a tokamak diverter, typically consists of three distinct sublayers: the Debye sheath (DS), the magnetic presheath (MPS) and the collisional presheath (CPS), with characteristic lengths λD (electron Debye length), ρi (ion gyroradius) and λ (smallest relevant ion collision length), respectively. For analytical simplicity one usually assumes the ordering λD ≪ ρi ≪ λ, or, equivalently, $\varepsilon _{Dm} \equiv \frac{{\lambda _D }}{{\rho _i }} \to 0$ and $\varepsilon _{mc} \equiv \frac{{\rho _i }}{\lambda } \to 0$ (‘asymptotic three-scale (A3S) limit’), in which the three sublayers are precisely defined. In the present work the equations and length scales governing the transition, or the ‘intermediate’ regions between neighboring sublayers (DS–MPS, MPS–CPS), in the A3S limit are derived, allowing one to avoid the singularities arising from the ϵDm → 0 and ϵmc → 0 approximations. The MPS entrance and the related Bohm–Chodura condition is defined in a natural way. It is found that in the hydrodynamic Ti = 0 approximation the intermediate scales and equations have a universal form and a similar structure not only for the MPS–DS and CPS–MPS transitions but also for the DS–CPS transition in the non-magnetized case.
Developing language in a developing body: the relationship between motor development and language development
Authors: IVERSON JANA M.
Published: January 2010

During the first eighteen months of life, infants acquire and refine a whole set of new motor skills that significantly change the ways in which the body moves in and interacts with the environment. In this review article, I argue that motor acquisitions provide infants with an opportunity to practice skills relevant to language acquisition before they are needed for that purpose; and that the emergence of new motor skills changes infants' experience with objects and people in ways that are relevant for both general communicative development and the acquisition of language. Implications of this perspective for current views of co-occurring language and motor impairments and for methodology in the field of child language research are also considered.
Incidence of hospitalization due to community-acquired rotavirus infection: a 12-year study (1996–2008)
Authors: CILLA G. , GOMARIZ M. , MONTES M. , MENDIBURU M. I. , PÉREZ-YARZA E. G. , PÉREZ-TRALLERO E.
Published: January 2010

The incidence of hospitalization for acute gastroenteritis (AGE) is a useful parameter to assess the utility of the new rotavirus vaccines in high-income countries. Children hospitalized for AGE were identified by searching hospital discharge data and the records of the microbiology laboratory of Hospital Donostia. Rotavirus antigen was investigated in 96·1% of the 1114 children aged 1 month to <5 years hospitalized for AGE in the study period. Nearly 40% were rotavirus positive (44·9% of the 798 children aged 1 month to <2 years), with G1[P8] being the predominant genotype. The mean annual incidence rate of hospitalization due to rotavirus AGE was 29·8 and 63·7 cases/10 000 inhabitants in the <5 and <2 years age groups, respectively, in 1996–1999, decreasing to 13·6 and 27·4 cases/10 000 inhabitants in <5 and <2 years age groups, respectively, in 2002–2005 (P<0·001). This decrease coincided with a significant increase in the consumption of oral rehydration solutions.
Declining HCV seroprevalence in pregnant women with HIV
Authors: FLORIDIA M. , TAMBURRINI E. , ANZIDEI G. , TIBALDI C. , MUGGIASCA M. L. , GUARALDI G. , FISCON M. , VIMERCATI A. , MARTINELLI P. , DONISI A. , DALZERO S. , RAVIZZA M. ,   for the Italian Group on Surveillance on Antiretroviral Treatment in Pregnancy
Published: January 2010

We assessed recent trends in hepatitis C virus (HCV) prevalence in pregnant women with HIV using data from a large national study. Based on 1240 pregnancies, we observed a 3·4-fold decline in HCV seroprevalence in pregnant women with HIV between 2001 (29·3%) and 2008 (8·6%). This decline was the net result of two components: a progressively declining HCV seroprevalence in non-African women (from 35·7% in 2001 to 16·7% in 2008), sustained by a parallel reduction in history of injecting drug use (IDU) in this population, and a significantly growing presence (from 21·2% in 2001 to 48·6% in 2008) of women of African origin, at very low risk of being HCV-infected [average HCV prevalence 1%, adjusted odds ratio (aOR) for HCV 0·09, 95% CI 0·03–0·29]. Previous IDU was the stronger determinant of HCV co-infection in pregnant women with HIV (aOR 30·9, 95% CI 18·8–51·1). The observed trend is expected to translate into a reduced number of cases of vertical HCV transmission.
Community-associated methicillin-resistant Staphylococcus aureus infections at an Army training installation
Authors: MORRISON-RODRIGUEZ S. M. , PACHA L. A. , PATRICK J. E. , JORDAN N. N.
Published: January 2010

To assess the burden of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in a high-risk population, the monthly incidence of laboratory-confirmed MRSA in service members/trainees stationed at Fort Benning, Georgia, USA without hospitalization or surgery documented 30 days prior to infection was calculated for calendar years 2002–2007. Clinical management and antibiotic susceptibility patterns were also evaluated. By 2007, ~67% of S. aureus strains were MRSA, and ~82% of these were community-associated, primarily in trainees. In total, 3531 CA-MRSA infections were identified. Rates appeared to be seasonal, peaking at 42 cases/1000 soldiers in 2005, with rates remaining above 35/1000 soldiers thereafter. Increased prescription of effective antibiotics was documented. Susceptibility to clindamycin, ciprofloxacin, and levofloxacin decreased from 2002 to 2007 by 6%, 17%, and 14%, respectively. The sustained high prevalence of CA-MRSA observed highlights the need for more vigilant population-based counter-measures at military training installations.
La construction détachée à gauche dans l'alternance des tours de parole
Authors: LIKHACHEVA LIDIA
Published: January 2010

Dans le présent article, je me propose de montrer comment les fonctions discursives de la Construction Détachée à Gauche (CDG) liées au marquage de la structure informationnelletopique/commentairese réalisent dans des contextes interactifs. Je pose notamment que la façon dont les occurrences de la CDG sont distribuées à travers la succession de tours de parole dépend en partie d'une stratégie discursive déployée par le locuteur, à savoir l’élicitation ou la narration. Les faits présentés ici ont pour visée de fournir des éléments de réponses nouveaux qui aident à mieux comprendre le rôle de la CDG dans l'organisation thématique et séquentielle du discours.
Organizations and economics
Authors: ADELSTEIN RICHARD
Published: January 2010

Judge Posner (2010) identifies organizational economics with the principal-agent problem and offers no definition of the crucial term organization, which leads him to force the principal-agent template on social formations that are not organizations and to neglect aspects of their operation that might be illuminated by alternative conceptions of organizational economics. This response offers an explicit characterization of organizations as central planning agencies, considers Posner's examples in light of the problems of purpose, information, and control faced by all central planners, and draws upon an emerging capabilities theory of organizations to extend the scope of Posner's analysis and suggest insights beyond those that flow from the principal-agent approach.
What do corporate directors maximize? (Not quite what everybody thinks)
Authors: AVIRAM AMITAI
Published: January 2010

The agency problem at the core of corporate law stems from a chronic potential conflict of interest between directors’ self-interest and that of shareholders. Corporate law views directors’ self-interest in terms of diverting welfare to directors at the expense of shareholders. Another component of directors’ self-interest – being perceived as maximizing shareholders’ welfare – is seen not as part of the agency problem, but as part of the solution (aligning directors’ incentives with shareholders’).

This is true only if taking actions that maximize shareholders’ welfare is also the optimal manner for a director to be perceived as maximizing welfare. However, directors have more appealing ways to be positively perceived. In conducting bias arbitrage, directors identify risks that shareholders over-estimate, take action to address the risk, and then take credit for the ‘lowered’ risk (i.e., shareholders’ corrected assessment of the risk).

Bias arbitrage is more attractive as shareholders’ misperception of a risk increases. The opportunity to bias arbitrage thus leads directors to address highly misperceived risks instead of highly remediable risks.
Comment on Richard A. Posner's organization economics
Authors: BACKHAUS JÜRGEN G.
Published: January 2010

The intellectual roots of law and economics, institutional economics, and the possible science of organization economics are here explored for a better understanding of what Posner is pushing for. The purpose is, of course, to gain better acceptance of his proposal. As it turns out, organization economics comes close to what has come to be called ‘the science of State’, i.e. treating law, economics, sociology, and political science as approaches to one and the same subject always to be taken together.
Richard Posner's economics of organization
Authors: CHOI YOUNG BACK
Published: January 2010

Posner's economics of organization yields an unconventional view that private organizations operating in the market, the publicly held US business corporation, despite the profit motive, ends up being inefficient, paying excessive compensation to CEOs, while some public organizations, the US federal judicial system (and the judicial system of Continental Europe and Japan), despite the insulation of judges from most of incentives and the near complete autonomy afforded to them, works reasonably well. Unfortunately, Posner does not state clearly the criteria by which he judges one ‘excessive’ and the others ‘works reasonably well’, nor does he explain well why professional norms of judges that play a crucial role in public organizations are not a factor in business organizations.
Judicial creativity and judicial errors: an organizational perspective
Authors: LUPPI BARBARA , PARISI FRANCESCO
Published: January 2010

The different role played by case law and the historical and conceptual differences between the doctrines of precedent in common law and civil law traditions are important determinants of judicial creativity. In this article, we consider a hybrid version of stare decisis, called by the French name of jurisprudence constante, adopted by mixed jurisdictions. Unlike stare decisis, which allows a single precedent to establish case law, the doctrine of jurisprudence constante links the recognition of a judge-made rule to the existence of a consecutive line of decisions affirming the same legal principle. We develop a model to consider the effects of this doctrine on the social costs arising from judicial error and uncertainty in case law. We further consider the effects of these alternative doctrines of precedent on judicial creativity and ideological bias in judge-made law.
Roll over George Stigler: Berle and Means meet Chicago price theory
Authors: MEDEMA STEVEN G.
Published: January 2010

Recent writings by Richard Posner in this Journal and elsewhere appear to mark a departure from the Chicago price theory tradition with which Posner long has been associated. This paper picks up on one facet of this: the similarity of Posner's views of the corporation, and of executive compensation in particular, to the perspective laid out by Adolf Berle and Gardiner Means in The Modern Corporation and Private Property – a perspective that has for decades been harshly rejected by the Chicago school.
Organizational economics: applications to metropolitan governance
Authors: OSTROM ELINOR
Published: January 2010

This comment relates to Richard Posner (2010), the lead article for this issue. Posner applies ‘the principles of organization economics’ to the study of diverse types of organizations. His study comparing the FBI to other types of police organization is important and compatible with the study of urban policing in American metropolitan areas. Many policy prescriptions are based on an inadequate understanding of the diversity of urban public good production functions and a lumping together of every type of police service. A brief review of research related to the concept of polycentricity as related to urban services in metropolitan areas is provided as a way of further illustrating Posner's concern that finer distinctions need to be made in the way scholars analyze organizational economics.
Designing incentives in organizations
Authors: ROBERTS JOHN
Published: January 2010

The design of incentive systems is a central issue in the economics of organization. This paper argues that very often the ideal incentive systems to use within firms will involve low-powered incentives. Five particular circumstances leading to weak incentives being optimal are examined.
Organization economics explains many forensic science errors
Authors: KOPPL ROGER
Published: January 2010

Judge Posner (2010) has identified an important lacuna in law and economics, namely a tendency to ignore organization theory. I will apply the tools of organization theory to an area almost completely neglected in law and economics, forensic science. Posner points us to tools we should make use of; I am pointing to an application we have neglected. Forensic science today is characterized by a twofold monopoly. First, evidence is typically examined by one crime lab only. Second, that same lab will normally be the only one to offer an interpretation of the results of the examination it performs. Crime labs today are typically organized under law enforcement agencies, which may create conscious and unconscious biases in favor of police and prosecution. These organizational features of forensic science today encourage errors and wrongful convictions.
Reply to comments
Authors: POSNER RICHARD A.
Published: January 2010

The 13 responses to my article are of high quality and suggest many fascinating directions for further research in the economics of organizations. I will not try to reply to all of them, in view of their number, but omissions should not be taken as criticism or that I think the response is not a contribution. I shall strive for brevity.