bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploiting joint synergy for actuation in a lower‐limb active orthosis
Authors: Sanz‐Merodio Daniel , Cestari Manuel , Carlos Arevalo Juan , Garcia Elena
Published: April 2013

Purpose

Lower‐limb exoskeletons and powered orthoses are external devices that assist patients with locomotive disorders to achieve correct limb movements. Current batteries cannot meet the long‐term power requirements for these devices, which operate for long periods of time. This issue has become a major challenge in the development of these portable robots. Conversely, legged locomotion in animals and humans is efficient; to emulate this behaviour, biomimetic actuation has been designed attempting to incorporate elements that resemble biological elements, such as tendons and muscles, in the mechanical systems. The purpose of this paper is to present a mechanism that resembles a human tendon to achieve and utilise the synergic actuation of the leg joints.

Design/methodology/approach

In this paper, we present a mechanism that resembles a human tendon to move the ankle joint and utilise the synergic actuation of hip and knee joints. Implementation of the proposed transmission system in the ATLAS active orthosis prototype allowed for a better ankle gait fit, which resulted in a more natural stride and, as expected, optimised energy consumption in the locomotion cycle and actuation energy requirements.

Findings

The fitted passive ankle motion provides toe‐off impulse, increases support force, and helps provide ground clearance.

Originality/value

A synergetic underactuated movement in the ankle joint, implemented by two cables in each leg, improves the functionality of the device without increasing the leg weight and while maintaining a reduced size. To achieve a correct and efficient motion in the ankle of an active orthosis, two steel cables were attached in the ATLAS orthosis. These cables act as a synergic biarticular linkage and transfer motion from the hip and knee joints. Synergic ankle motion provides impulse in the toe‐off, increases support force, and provides ground clearance. These goals are achieved with low energy expenditure because of synergical actuation, and high inertia is prevented in the more distal limb.
Increased performance in a bottom‐up designed robot by experimentally guided redesign
Authors: Larsen Jorgen , Stoy Kasper , Brandt David , Grimmer Sten , Groß Martin
Published: April 2013

Purpose

Using a bottom‐up, model‐free approach when building robots is often seen as a less scientific way, compared to a top‐down model‐based approach, because the results are not easily generalizable to other systems. The authors, however, hypothesize that this problem may be addressed by using solid experimental methods. The purpose of this paper is to show how well‐known experimental methods from bio‐mechanics are used to measure and locate weaknesses in a bottom‐up, model‐free implementation of a quadruped walker and come up with a better solution.

Design/methodology/approach

To study the bottom‐up, mode‐free approach, the authors used the robotic construction kit, LocoKit. This construction kit allows researchers to construct legged robots, without having a mathematical model beforehand. The authors used no specific mathematical model to design the robot, but instead used intuition and took inspiration from biology. The results were afterwards compared with results gained from biology, to see if the robot has some of the key elements the authors were looking for.

Findings

With the use of LocoKit as the experimental platform, combined with known experimental measurement methods from biology, the authors have shown how a bottom‐up, model‐free design approach can be used to gain specific knowledge on a robotic platform, and also how knowledge can potentially be generalized from this approach.

Originality/value

This paper shows that even though a bottom‐up, model‐free approach was taken, the results can still be compared with results from, for example, biology, because solid experimental methods were used.
Design and control method for a high‐mobility in‐pipe robot with flexible links
Authors: Jeon Woongsun , Kim Inho , Park Jungwan , Yang Hyunseok
Published: April 2013

Purpose

The purpose of this paper is to propose a high‐mobility in‐pipe robot platform and its navigation strategy for navigating in T‐branch pipes efficiently.

Design/methodology/approach

For high mobility, this robot is developed based on inchworm locomotion. An extensor mechanism with flexible links and clamper mechanisms enable the robot to conduct both steering and inchworm locomotion. The locomotion of the robot is modeled based on a pseudo‐rigid‐body model. From the developed model, this paper introduces a navigation strategy based on defining relay points and generating a path from a main pipe to a T‐branch pipe.

Findings

With this navigation strategy, the robot can avoid collisions and enter T‐branch pipes effectively. The path generation algorithm is verified by experiment. In addition, both the navigation strategy and mobility of the robot are demonstrated by experiments conducted in a commercial pipe configuration.

Originality/value

This paper describes the mechanism of an inchworm‐type in‐pipe robot that is able to steer and adapt to pipe diameter changes. This paper also describes navigation strategy that enables a robot to avoid collisions and enter T‐branch pipes effectively. This research will help the construction of a fully autonomous in‐pipe robot that can navigate through various types of pipes.
CEO duality: how many hats are too many?
Authors: Abels Patricia B. , Martelli Joseph T.
Published: April 2013

Purpose

This paper aims to concentrate on the prevailing agency theory along with its complementary theory of stewardship as foundations for the authors' research. Recent economic turmoil within the USA has resulted in stakeholders demanding change within governance policies of corporations. One such adjustment has been the separation of the CEO and Chairman positions within organizations. The authors' study seeks to uncover the extent to which duality CEO relationships exist in large corporations within the USA. In light of the push towards splitting the dual roles, the authors further investigated new CEOs recently appointed into the CEO position.

Design/methodology/approach

Companies selected for this study were the top 500 revenue‐producing companies in the USA as published by Fortune magazine in 2008. For comparison purposes, the authors' database included newly appointed CEOs coming on board with the original 2008 companies that had remained on the listing for both years as published by Fortune in 2010. The authors' 2008 database included 500 companies and their 2010 database included 86 companies. The North American Industry Classification System (NAICS) was the product classification used in order to establish the principal industry sector for companies under analysis.

Findings

The authors' 2008 analysis reveals that 303 CEOs hold a combination title of CEO and Chairman. The most frequent title combination is CEO and Chairman, with 156 executives holding this combined title. The authors' 2010 analysis reveals that 33 new CEOs hold a combination title of CEO and Chairman. The most frequent title combination is CEO and President with 43 executives holding the title. The authors' analysis of retired CEOs reveals that 15 retired CEOs continue serving in the capacity of Chairman of the Board of Directors.

Research limitations/implications

Using the top 500 companies in the USA, based upon sales revenue, did limit the study to large corporations within the USA.

Originality/value

The agency theory does provide an explanation of the duality movement witnessed in corporations. The practice of splitting duality roles of CEO and Chairman within public corporations appears to be becoming a reality within the USA, whether on a voluntary or a mandatory basis in order to enhance corporate independence and transparency.
Do global models predicting environmental suitability for the amphibian fungus, Batrachochytrium dendrobatidis, have local value to conservation managers?
Authors: Riley Karen , Berry Oliver F. , Roberts J. Dale
Published: April 2013

The amphibian chytrid fungus Batrachochytrium dendrobatidis is a major cause of frog declines globally.

Two recent Maxent models predict high environmental suitability for B. dendrobatidis in south‐western Australia despite severe summer drought and many frog species with direct development or breeding in ephemeral water bodies: features often associated with absence of B. dendrobatidis.

We determined B. dendrobatidis occurrence and intensity of infection, in 15 populations of Crinia georgiana, a frog that breeds in ephemeral ponds, to assess (i) current validity of claims about environmental suitability, (ii) risk of decline against recent suggestions of 100% prevalence and chytrid loads of > 10 000 zoospore equivalents per frog as predictors of imminent decline and (iii) assess apparent change in prevalence over 20 years.

Batrachochytrium dendrobatidis occurred on 40–100% of frogs at all sites and in water samples at 11 sites but infection levels were generally well below 10 000 zoospore equivalents per frog. Based on immediate and 5‐year climate averages, higher rainfall, more rain days and temperatures > 3 °C but < 30 °C were positively correlated with infection levels – consistent with the known physiology and growth patterns of B. dendrobatidis. Overall infection levels have changed little from 1992 to 2008.

Synthesis and applications. Predicted and realized high environmental suitability for B. dendrobatidis is not correlated with frog decline in south‐western Australia. Innate or acquired immunity, chytrid strain type and limited opportunities for chytrid growth may all explain absence of chytrid impacts. Occurrence of Batrachochytrium dendrobatidis is not a current critical management issue for conservation managers in south‐western Australia despite a known presence since 1985. Models predicting high environmental suitability for chytrid in Mediterranean climate zones should be interpreted cautiously in the absence of documentation of current, rather than historic, chytrid loads and a clear evaluation of any occurrence of chytrid on frog survival.
Molecular cloning and characterization of a putative proline dehydrogenase gene in the Colorado potato beetle, Leptinotarsa decemlineata
Authors: Wan Pin‐Jun , Lü Dong , Guo Wen‐Chao , Ahmat Tursun , Yang Lu , Mu Li‐Li , Li Guo‐Qing
Published: April 2013

Leptinotarsa decemlineata adults exhibit a season‐dependent activity. In spring, post‐diapause beetles often fly a long distance from overwintering sites to potato fields. In summer and autumn, the flight ability is sharply reduced. Proline is the main energy substrate of L. decemlineata during flight and proline dehydrogenase (ProDH) catalyzes the first step in proline catabolism. Here we identified a putative LdProDH gene; it had three cDNA isoforms which shared the same 5′UTR and coding region, but differed in the lengths of 3′UTRs (515, 1 092 and 1 242 bp for isoforms‐1, ‐2 and ‐3, respectively). LdProDH encoded a 616 amino acid protein that showed high sequence similarity to ProDH‐like proteins from other insect species. LdProDH was expressed in the third and fourth instars larvae and adults, but not in pupae. Dietary ingestion of bacterially expressed LdProDH‐dsRNA by adults significantly decreased its messenger RNA (mRNA) level, and caused an elevation of free proline content in the hemolymph. Further observation revealed that three canonical polyadenylation signals (AATAAA) were tandemly located in the 3′UTR of isoform‐3. The first, second and third polyadenylation sites gave rise to isoforms‐1, ‐2 and ‐3, respectively. Analysis of the genomic DNA uncovered that the three isoforms resulted from alternative polyadenylation. The mRNA level of isoform‐1, which expressed at low levels in pre‐diapause adults, became abundant in post‐diapause beetles. It is indicated that the LdProDH expression is fine‐tuned through 3′UTR to control proline catabolism for the season‐dependent activity of L. decemlineata adults.
Shared risk: who engages in substance use with American homeless youth?
Authors: Green Harold D. , de la Haye Kayla , Tucker Joan S. , Golinelli Daniela
Published: April 2013

Aims

To identify characteristics of social network members with whom homeless youth engage in drinking and drug use.

Design

A multi‐stage probability sample of homeless youth completed a social network survey.

Setting

Forty‐one shelters, drop‐in centers and known street hangouts in Los Angeles County.

Participants

A total of 419 homeless youth, aged 13–24 years (mean age = 20.09, standard deviation = 2.80).

Measurements

Respondents described 20 individuals in their networks, including their substance use and demographics, and the characteristics of the relationships they shared, including with whom they drank and used drugs. Dyadic, multi‐level regressions identified predictors of shared substance use.

Findings

Shared drinking was more likely to occur with recent sex partners [odds ratio (OR) = 2.64, confidence interval (CI): 1.67, 4.18], drug users (OR = 4.57, CI: 3.21, 6.49), sexual risk takers (OR = 1.71, CI: 1.25, 2.33), opinion leaders (OR = 1.69, CI: 1.42, 2.00), support providers (OR = 1.41, CI: 1.03, 1.93) and popular people (those with high degree scores in the network) (OR = 1.07, CI: 1.01, 1.14). Shared drug use was more likely to occur with recent sex partners (OR = 2.44, CI: 1.57, 3.80), drinkers (OR = 4.53, CI: 3.05, 6.74), sexual risk takers (OR = 1.51, CI: 1.06, 2.17), opinion leaders (OR = 1.24, CI: 1.03, 1.50), support providers (OR = 1.83, CI: 1.29, 2.60) and popular people (OR = 1.16, CI: 1.08, 1.24).

Conclusions

Homeless youth in the United States are more likely to drink or use drugs with those who engage in multiple risk behaviors and who occupy influential social roles (popular, opinion leaders, support providers, sex partners). Understanding these social networks may be helpful in designing interventions to combat substance misuse.
Growing teratoma syndrome: Brief communication and algorithm for management
Authors: Byrd Kevin , Stany Michael P. , Herbold Natasha C. , Leath Charles A. , Hamilton Chad A.
Published: April 2013

Growing teratoma syndrome (GTS) is a rare condition among women with ovarian germ cell tumours. Women with GTS classically present during or after systemic chemotherapy with normalised tumour markers and a mass pathologically consistent with mature teratoma. Awareness of this syndrome is necessary to prevent unnecessary chemotherapy and allow optimal management. We report five cases of ovarian GTS as examples of the clinical dilemmas encountered with these women and provide recommendations and an algorithm to guide potential management.
Oesophageal bacterial biofilm changes in gastro‐oesophageal reflux disease, Barrett's and oesophageal carcinoma: association or causality?
Authors: Blackett K. L. , Siddhi S. S. , Cleary S. , Steed H. , Miller M. H. , Macfarlane S. , Macfarlane G. T. , Dillon J. F.
Published: April 2013

Barrett's oesophagus (BO) and gastro‐oesophageal reflux disease (GERD) are precursors of oesophageal adenocarcinoma (OAC). There is an oesophageal biofilm, which changes in disease, but its role in aetiopathogenesis remains unclear.

Aim

To define the oesophageal microbiota of patients with GERD, BO and OAC compared with controls and to investigate mucosal responses related to the microbiota.

Methods

Cultural analysis identified the dominant bacterial species from a subset of each disease group. Based on this, molecular techniques were used to define the cohort. Host responses were analysed in tissues and co‐culture experiments.

Results

A total of 111 species belonging to 26 genera were isolated. There was a significant decrease in bacterial counts in the GERD and BO groups for all genera except Campylobacter, which colonised GERD and Barrett's patients in increasing numbers. Campylobacter concisus was the dominant species. This relationship was not seen in the cancer group. Significant increases in IL‐18 were seen in GERD and BO colonised by Campylobacter.

Conclusions

This study defines differences in the oesophageal biofilm in disease states, revealing the emergence of C. concisus as the dominant new colonist in the refluxed oesophagus. We also associate the presence of these bacteria with increased expression of cytokines related to carcinogenesis.
Efficacy of nasopancreatic stenting prior to laparoscopic enucleation of pancreatic neuroendocrine tumor
Authors: Misawa Takeyuki , Imazu Hiroo , Fujiwara Yuki , Kitamura Hiroaki , Tsutsui Nobuhiro , Ito Ryusuke , Shiba Hiroaki , Futagawa Yasuro , Wakiyama Shigeki , Ishida Yuichi , Yanaga Katsuhiko
Published: April 2013

We report a patient who underwent laparoscopic enucleation for a nonfunctioning pancreatic neuroendocrine tumor. The patient was a 55‐year‐old man who had a 12‐ × 11‐mm tumor close to the main pancreatic duct (MPD) in the pancreatic body. To avoid and detect injury to the main pancreatic duct during operation, a nasopancreatic drainage stent (NPDS) was endoscopically placed prior to the operation. According to the NPDS, the relation between the tumor and MPD was easily identified by laparoscopic ultrasonography during enucleation, thus enabling the resecting line to be determined. Moreover, after enucleation, pancreatography through the NPDS was able to clarify the absence of injury to the MPD. The NPDS was removed postoperatively, and the patient was discharged uneventfully on postoperative day 8. Preoperative placement of the NPDS seems to be a useful option for performing safe laparoscopic enucleation of pancreatic neuroendocrine tumor, especially when the lesion is located close to the MPD.
Perforated gastrointestinal stromal tumor in Meckel's diverticulum treated laparoscopically
Authors: López‐Tomassetti Fernández Eudaldo M. , Hernández Hernández Juan Ramón , Nuñez Jorge Valentin
Published: April 2013

Gastrointestinal stromal tumors (GIST) can represent a source of substantial gastrointestinal hemorrhage. Bleeding is described as a frequent cause of clinical presentation and commonly patients received surgical treatment on an urgent basis to drain the hematoma. However, a literature review has shown that perforation with peritonitis is very uncommon and rarely reported. These tumors are usually located in the stomach, and primary ileal and Meckel's localization is rare, occurring in less than 10% of cases in many series. In the English literature, we have found seven well‐reported cases of GIST in a Meckel's diverticulum that presented with perforation and peritonitis; these case were found through a MEDLINE search of the terms: “perforated” GISTs in “Meckel's” GISTs. Herein, we describe a rare case of a perforated GIST in Meckel's diverticulum that caused severe peritonitis and that was treated with minimally invasive surgery.
Absence of both MDR1 (ABCB1) and Breast Cancer Resistance Protein (ABCG2) Transporters Significantly Alters Rivaroxaban Disposition and Central Nervous System Entry
Authors: Gong Inna Y. , Mansell Sara E. , Kim Richard B.
Published: April 2013

Rivaroxaban is a novel factor 10a inhibitor, where hepatic metabolism and renal clearance account for its overall disposition. Renal impairment is known to increase rivaroxaban‐associated bleeding risk in patients. As renal rivaroxaban clearance exceeds glomerular filtration rate, we suggested that active secretion by efflux transporters P‐glycoprotein (MDR1) and breast cancer resistance protein (BCRP) contributes to rivaroxaban clearance. The ability of MDR1 and BCRP efflux transporters to mediate rivaroxaban transport in vitro was assessed in polarized cell monolayers. A significantly greater vectorial transport of rivaroxaban was observed in the basal to apical direction in Caco‐2 cells, which was attenuated in the presence of the selective inhibitors. After oral administration of rivaroxaban (2 mg/kg), plasma concentrations did not significantly differ between wild‐type and Mdr1adef or Bcrp−/− mice (n = 6 per group). However, rivaroxaban clearance was significantly reduced in Mdr1a/Mdr1b−/−/Bcrp−/− mice. Interestingly, rivaroxaban brain‐to‐plasma ratio did not differ in mice lacking only Mdr1a or Bcrp, but more than two times higher in the Mdr1a/Mdr1b−/−/Bcrp−/− mice. Rivaroxaban is a shared substrate of MDR1 and BCRP. In vivo, MDR and BCRP function synergistically to modulate rivaroxaban disposition and appear to be particularly relevant to limiting its central nervous system entry. These data have important implications for safety and efficacy of anticoagulation therapy with rivaroxaban as many drugs in clinical use are known MDR1 inhibitors and loss‐of‐function polymorphisms in BCRP are common.
Effect of FSH Receptor‐Binding Inhibitor‐8 on FSH‐Mediated Granulosa Cell Signaling and Proliferation
Authors: Navalakhe Rajshri M. , Jagtap Dhanashree D. , Nayak Sumeet U. , Nandedkar Tarala D. , Mahale Smita D.
Published: April 2013

Follicle‐stimulating hormone is important for mammalian reproduction. It acts through specific receptors located on the plasma membrane of granulosa cells in ovaries and Sertoli cells in testes. The binding of follicle‐stimulating hormone to its receptor activates intracytoplasmic signaling pathways leading to steroidogenesis. These steroids in turn regulate the follicle‐stimulating hormone action from the anterior pituitary through exerting negative feedback effect. In addition to steroids, non‐steroidal factors secreted by the ovaries are believed to modulate follicle‐stimulating hormone action through autocrine/paracrine mode. One such low molecular weight peptide referred to as follicle‐stimulating hormone receptor‐binding inhibitor‐8 purified from human follicular fluid has been extensively studied. Follicle‐stimulating hormone receptor‐binding inhibitor‐8 has been shown to inhibit binding of follicle‐stimulating hormone to its receptor. The present article describes the effect of follicle‐stimulating hormone receptor‐binding inhibitor‐8 on follicle‐stimulating hormone‐induced signaling in rat granulosa cells. Follicle‐stimulating hormone receptor‐binding inhibitor‐8 inhibited the follicle‐stimulating hormone‐induced cAMP, and the effect was observed to be mediated through the protein kinase A. Further, an inhibitory effect of follicle‐stimulating hormone receptor‐binding inhibitor‐8 on the granulosa cell proliferation was evaluated using COV434 cell line which is derived from the human granulosa cell tumor. The effect of the peptide on the cell cycle analysis showed an increase in apoptotic population and the arrest of G1 phase. These findings suggest that follicle‐stimulating hormone receptor‐binding inhibitor‐8 acts as a follicle‐stimulating hormone antagonist and affects the follicle‐stimulating hormone‐mediated signaling and proliferation in the granulosa cells.
Comparison of the Pentacam equivalent keratometry reading and IOL Master keratometry measurement in intraocular lens power calculations
Authors: Karunaratne Nicholas
Published: April 2013

Background

To compare the accuracy of the Pentacam Holladay equivalent keratometry readings with the IOL Master 500 keratometry in calculating intraocular lens power.

Design

Non‐randomized, prospective clinical study conducted in private practice.

Participants

Forty‐five consecutive normal patients undergoing cataract surgery.

Methods

Forty‐five consecutive patients had Pentacam equivalent keratometry readings at the 2‐, 3 and 4.5‐mm corneal zone and IOL Master keratometry measurements prior to cataract surgery. For each Pentacam equivalent keratometry reading zone and IOL Master measurement the difference between the observed and expected refractive error was calculated using the Holladay 2 and Sanders, Retzlaff and Kraff theoretic (SRKT) formulas.

Main Outcome Measure

Mean keratometric value and mean absolute refractive error.

Results

There was a statistically significantly difference between the mean keratometric values of the IOL Master, Pentacam equivalent keratometry reading 2‐, 3‐ and 4.5‐mm measurements (P < 0.0001, analysis of variance). There was no statistically significant difference between the mean absolute refraction error for the IOL Master and equivalent keratometry readings 2 mm, 3 mm and 4.5 mm zones for either the Holladay 2 formula (P = 0.14) or SRKT formula (P = 0.47). The lowest mean absolute refraction error for Holladay 2 equivalent keratometry reading was the 4.5 mm zone (mean 0.25 D ± 0.17 D). The lowest mean absolute refraction error for SRKT equivalent keratometry reading was the 4.5 mm zone (mean 0.25 D ± 0.19 D). Comparing the absolute refraction error of IOL Master and Pentacam equivalent keratometry reading, best agreement was with Holladay 2 and equivalent keratometry reading 4.5 mm, with mean of the difference of 0.02 D and 95% limits of agreement of −0.35 and 0.39 D.

Conclusions

The IOL Master keratometry and Pentacam equivalent keratometry reading were not equivalent when used only for corneal power measurements. However, the keratometry measurements of the IOL Master and Pentacam equivalent keratometry reading 4.5 mm may be similarly effective when used in intraocular lens power calculation formulas, following constant optimization.
Retinal nerve fibre layer imaging: comparison of Cirrus optical coherence tomography and Heidelberg retinal tomograph 3
Authors: Kratz Assaf , Lim Ridia , Rush Ryan , Sheth Saumil , Goldberg Ivan
Published: April 2013

Background

The purpose of this study was to analyze the relationship between retinal nerve fibre layer thickness measured by spectral domain optical coherence tomography and confocal scanning laser ophthalmoscope.

Design

Prospective, cross‐sectional study. Hospital setting.

Participants

One hundred seventy‐three subjects (85 glaucoma and 88 normal subjects).

Methods

One eye from each individual was selected randomly for imaging by the spectral domain Cirrus optical coherence tomography and Heidelberg retinal tomograph 3.

Main Outcome Measures

Global thickness and measurements at the four quadrants around the optic disc.

Results

Measurements as determined by Heidelberg retinal tomograph 3 were significantly larger than measurements done by Cirrus optical coherence tomography (respectively in mm, for global thickness: 200.0 ± 87.2 and 80.7 ± 14.7; for temporal quadrant: 75.3 ± 31.9 and 59.1 ± 13.8; for superior quadrant: 223.2 ± 128.4 and 97.7 ± 20.9; for nasal quadrant: 208.0 ± 102.9 and 66.8 ± 11.8; and for inferior quadrant: 224.4 ± 116.9 and 99.1 ± 26.6, for all P < 0.01). Significant correlation was found for all measurements (P ≤ 0.009), but a pattern of proportional bias was demonstrated. The agreement of categorical classification (within normal limits, borderline or outside normal limits) ranged between poor and fair.

Conclusions

The thickness easurements by the two technologies are strongly correlated but significantly different. The differences are substantial and proportional to the retinal nerve fibre layer thickness. The normative diagnostic classification of the two technologies may not agree. The results preclude interchangeable use of these measurements in clinical practice.
Pro‐osteogenic topographical cues promote early activation of osteoprogenitor differentiation via enhanced TGFβ, Wnt, and Notch signaling
Authors: Chakravorty Nishant , Hamlet Stephen , Jaiprakash Anjali , Crawford Ross , Oloyede Adekunle , Alfarsi Mohammed , Xiao Yin , Ivanovski Saso
Published: April 2013

Objectives

Titanium implant surfaces with modified topographies have improved osteogenic properties in vivo. However, the molecular mechanisms remain obscure. This study explored the signaling pathways responsible for the pro‐osteogenic properties of micro‐roughened (SLA) and chemically/nanostructurally (modSLA) modified titanium surfaces on human alveolar bone‐derived osteoprogenitor cells (BCs) in vitro.

Materials and methods

The activation of stem cell signaling pathways (TGFβ/BMP, Wnt, FGF, Hedgehog, Notch) was investigated following early exposure (24 and 72 h) of BCs to SLA and modSLA surfaces in the absence of osteogenic cell culture supplements.

Results

Key regulatory genes from the TGFβ/BMP (TGFBR2, BMPR2, BMPR1B, ACVR1B, SMAD1, SMAD5), Wnt (Wnt/β‐catenin and Wnt/Ca2+) (FZD1, FZD3, FZD5, LRP5, NFATC1, NFATC2, NFATC4, PYGO2, LEF1) and Notch (NOTCH1, NOTCH2, NOTCH4, PSEN1, PSEN2, PSENEN) pathways were upregulated on the modified surfaces. These findings correlated with a higher expression of osteogenic markers bone sialoprotein (IBSP) and osteocalcin (BGLAP), and bone differentiation factors BMP2, BMP6, and GDF15, as observed on the modified surfaces.

Conclusions

These findings demonstrate that the activation of the pro‐osteogenic cell signaling pathways by modSLA and SLA surfaces leads to enhanced osteogenic differentiation as evidenced after 7 and 14 days culture in osteogenic media and provides a mechanistic insight into the superior osseointegration on the modified surfaces observed in vivo.
One thousand cases of severe occupational contact dermatitis
Authors: Schwensen Jakob Ferløv , Friis Ulrik Fischer , Menné Torkil , Johansen Jeanne Duus
Published: April 2013

Background.

Occupational contact dermatitis is frequent, and further understanding of the epidemiology will improve the basis of its prevention.

Objectives.

To identify occupations at risk for severe occupational contact dermatitis.

Methods.

The last 1000 cases of severe occupational contact dermatitis seen at our department were identified.

Results.

The study population comprised 618 females and 382 males. The mean age at onset of irritant contact dermatitis was significantly lower than the mean age at onset of allergic contact dermatitis for both sexes, irrespective of the presence of atopic dermatitis. Females at high riskwere cooks, butchers, beauticians, bakers, and hairdressers, ranging from 23.3 to 96.8 cases per 10 000 workers per year. Males at high risk were painters, cooks, mechanics, locksmiths, and bakers, ranging from 16.5 to 32.3 cases per 10000 workers per year.

Conclusions.

Occupational contact dermatitis remains frequent, even if only severe cases are considered. It is a concern that no effective, systematic interventions and prevention schemes have been launched in Europe, despite documentation of a significant problem overmany years, and knowledge of risk occupations and risk factors. This study suggests new approaches for general and specific prevention of occupational contact dermatitis.
Surgical resection of retrorectal tumours in adults: long‐term results in 47 patients
Authors: Chéreau N. , Lefevre J. H. , Meurette G. , Mourra N. , Shields C. , Parc Y. , Tiret E.
Published: April 2013

Aim

Retrorectal tumours (RT) are uncommon, and diagnosis and management remain difficult. The aim of this study was to evaluate the results of the surgical management ofRTin our institution.

Method

Medical notes of all patients operated on forRTwere reviewed. Clinical, radiological, surgical, histological data as well as morbidity and long‐term results were noted.

Results

Forty‐seven patients [34 women (72%), mean age 45.8 (range 17–85) years] underwent surgery forRTbetween 1997 and 2011. The commonest symptoms were pain (n = 31) and suppuration (n = 10). Thirty‐nine (83%) patients underwent preoperative magnetic resonance imaging (MRI). Malignant lesions exhibited typical characteristics onMRIincluding heterogeneity (n = 5, 83%), solid appearance (n = 4, 67%), a low‐T1 signal and high‐T2 intensity (n = 5, 83%), enhancement after gadolinium injection (n = 5, 83%), irregular margin (n = 4, 67%) and extension above S3 (i = 5, 83%). AKraske approach was used in 42 (89%) patients with resection of the coccyx in 25 (60%) and an abdominal or combined approach for the remaining five. Four patients developed complications (two haematoma, two abscess), but only one (haematoma) required reoperation. Histological examination showed 38 (80.9%) benign lesions. After a median follow‐up of 71 (2–168) months, 5‐year disease‐free survival was 75% for malignant lesions and 93.1% for benign lesions (P = 0.023). Four (4/42; 9.5%) patients had moderate perineal pain after aKraske approach, while no anal dysfunction was seen.

Conclusion

Magnetic resonance imaging was the most helpful investigation for retrorectal tumours. The posterior trans‐sacrococcygeal approach is the procedure of choice for complete resection for most, especially for benign and cystic lesions without extension aboveS2.
Commercial trade of federally listed threatened and endangered plants in the United States
Authors: Shirey Patrick D. , Kunycky Brianna N. , Chaloner Dominic T. , Brueseke Michael A. , Lamberti Gary A.
Published: April 2013

The commercial trade of propagated listed plants is a common but controversial ex situ conservation approach for rare plant species. We investigated the Internet trade of plants protected under the U.S. Endangered Species Act to determine their availability for interstate (i.e., regulated) commerce. We identified 49 listed plant species that were available via the Internet, with less than 10% of vendors having obtained the required federal permit. The lack of permits among vendors suggests that sellers are unaware or ignore regulations. Illegal trade undermines both the permitting process and conservation efforts of the U.S. Fish and Wildlife Service to ensure that commercial propagation aids the long‐term survival of listed species. Furthermore, in addition to supplying a demand for plant collections and landscaping, commercial trade could provide a source of plants for deliberate species introductions, including assisted colonization—a debated conservation strategy that involves moving species to new environments to mitigate for habitat loss and climate change. Given the potential costs and benefits associated with trade, the challenges suggest that a collaborative approach between agencies, nurseries, and plant collectors is needed to regulate the trade of listed plants. In regulating commercial trade, policymakers and conservation biologists may want to consider potential risks and benefits of private efforts to recover species.
On the dynamics of dental fear: dental or mental?
Authors: Hägglin Catharina , Carlsson Sven G. , Hakeberg Magnus
Published: April 2013

This study explored possible predictors of change over time in dental fear. In a population‐based sample of 664 women, 38–54 yr of age at first assessment, a self‐rating of dental fear was recorded on two occasions, 6 yr apart. Whilst the majority of the women maintained their level of fear, two subgroups reported changes at follow up. Of the 99 subjects indicating high fear at baseline, 54 recorded no or minimal fear at follow up and, among the 565 recording minimal fear at baseline, 27 reported increased fear at follow up. We used psychological and odontological findings at baseline to compare the four subgroups with altered or maintained fear ratings at follow up. The women reporting reduced fear at follow up differed significantly in the psychological variables from those reporting unchanged fear; there were no significant differences between these groups in any of the odontological variables. The group indicating increased fear at follow up did not differ from those with a maintained fearlessness in any of the baseline measurements. The results are discussed in terms of a systems‐oriented understanding of the development of dental fear.
Iron oxidation stimulates organic matter decomposition in humid tropical forest soils
Authors: Hall Steven J. , Silver Whendee L.
Published: April 2013

Humid tropical forests have the fastest rates of organic matter decomposition globally, which often coincide with fluctuating oxygen (O2) availability in surface soils. Microbial iron (Fe) reduction generates reduced iron [Fe(II)] under anaerobic conditions, which oxidizes to Fe(III) under subsequent aerobic conditions. We demonstrate that Fe (II) oxidation stimulates organic matter decomposition via two mechanisms: (i) organic matter oxidation, likely driven by reactive oxygen species; and (ii) increased dissolved organic carbon (DOC) availability, likely driven by acidification. Phenol oxidative activity increased linearly with Fe(II) concentrations (P < 0.0001, pseudo R2 = 0.79) in soils sampled within and among five tropical forest sites. A similar pattern occurred in the absence of soil, suggesting an abiotic driver of this reaction. No phenol oxidative activity occurred in soils under anaerobic conditions, implying the importance of oxidants such as O2 or hydrogen peroxide (H2O2) in addition to Fe(II). Reactions between Fe(II) and H2O2 generate hydroxyl radical, a strong nonselective oxidant of organic compounds. We found increasing consumption of H2O2 as soil Fe(II) concentrations increased, suggesting that reactive oxygen species produced by Fe(II) oxidation explained variation in phenol oxidative activity among samples. Amending soils with Fe(II) at field concentrations stimulated short‐term C mineralization by up to 270%, likely via a second mechanism. Oxidation of Fe(II) drove a decrease in pH and a monotonic increase in DOC; a decline of two pH units doubled DOC, likely stimulating microbial respiration. We obtained similar results by manipulating soil acidity independently of Fe(II), implying that Fe(II) oxidation affected C substrate availability via pH fluctuations, in addition to producing reactive oxygen species. Iron oxidation coupled to organic matter decomposition contributes to rapid rates of C cycling across humid tropical forests in spite of periodic O2 limitation, and may help explain the rapid turnover of complex C molecules in these soils.
Bioactive Glasses: From Macro to Nano
Authors: Izquierdo‐Barba Isabel , Salinas Antonio J. , Vallet‐Regí María
Published: April 2013

Bioactive glasses play an important role for the bone defects treatment. Forty years ago, it was discovered the first bioactive glass, Bioglass®, obtained by melting and used in Orthopedics and Dentistry. Twenty years ago, another family of bioactive glasses obtained by solgel processing was reported. Solgel glasses exhibit high textural properties and quicker bioactive response than melt glasses. However, their presence in the market is scarce which could be explained considering that the improvements they bring do not justify the costs of their translation to product. In the last decade, so‐called template glasses exhibiting greater bioactivity than solgel glasses were described. These glasses display high pore volume and ordered mesopore structure, which makes them optimal candidates for hosting biologically active substances. For these characteristics, template glasses are being considered ideal candidates for the scaffolds manufacture used in bone engineering. This article shows the main features of three families of bioactive glasses and the importance of their nanostructure in the bioactivity. We demonstrate here that glasses with identical composition may exhibit very different properties, specifically bioactivity, as a function of their nanostructure. This fact demonstrates the importance of controlling this nanostructure in the design of new bioactive materials for bone regeneration.
Effects of Initial Audit Fee Discounts on Audit Quality: Evidence from Germany
Authors: Krauß Patrick , Quosigk Benedikt M. , Zülch Henning
Published: April 2013

We examine the presence and magnitude of initial audit engagement fee cutting and its potential effect on audit quality in Germany using a sample of 992 firm‐year observations from 2005 through 2011. Our results show systematic fee cutting for initial audit engagement years in Germany. Despite significant audit fee differences between initial and subsequent audit engagement years, we do not find differences in audit quality. Overall, our findings support prior empirical studies, suggesting that low‐balling is merely a natural response of auditors to competitive audit market conditions and does not necessarily impair auditor independence. In the wake of the on‐going discussion in the European Union regarding the control of appointment, remuneration, and duration of audit engagements to curb threats to auditor independence, our findings do not support the implementation of audit market price controls through governmental regulators.
Training pharmacists to deliver a complex information technology intervention (PINCER) using the principles of educational outreach and root cause analysis
Authors: Sadler Stacey , Rodgers Sarah , Howard Rachel , Morris Caroline J , Avery Anthony J
Published: April 2013

Objective

To describe the training undertaken by pharmacists employed in a pharmacist-led information technology-based intervention study to reduce medication errors in primary care (PINCER Trial), evaluate pharmacists’ assessment of the training, and the time implications of undertaking the training.

Methods

Six pharmacists received training, which included training on root cause analysis and educational outreach, to enable them to deliver the PINCER Trial intervention. This was evaluated using self-report questionnaires at the end of each training session. The time taken to complete each session was recorded. Data from the evaluation forms were entered onto a Microsoft Excel spreadsheet, independently checked and the summary of results further verified. Frequencies were calculated for responses to the three-point Likert scale questions. Free-text comments from the evaluation forms and pharmacists’ diaries were analysed thematically.

Key findings

All six pharmacists received 22 h of training over five sessions. In four out of the five sessions, the pharmacists who completed an evaluation form (27 out of 30 were completed) stated they were satisfied or very satisfied with the various elements of the training package. Analysis of free-text comments and the pharmacists’ diaries showed that the principles of root cause analysis and educational outreach were viewed as useful tools to help pharmacists conduct pharmaceutical interventions in both the study and other pharmacy roles that they undertook. The opportunity to undertake role play was a valuable part of the training received.

Conclusions

Findings presented in this paper suggest that providing the PINCER pharmacists with training in root cause analysis and educational outreach contributed to the successful delivery of PINCER interventions and could potentially be utilised by other pharmacists based in general practice to deliver pharmaceutical interventions to improve patient safety.
Robotic removal of eroded vaginal mesh into the bladder
Authors: Macedo Francisco Igor B , O'Connor Jeffrey , Mittal Vijay K , Hurley Patrick
Published: April 2013

Vaginal mesh erosion into the bladder after midurethral sling procedure or cystocele repair is uncommon, with only a few cases having been reported in the literature. The ideal surgical management is still controversial. Current options for removal of eroded mesh include: endoscopic, transvaginal or abdominal (either open or laparoscopic) approaches. We, herein, present the first case of robotic removal of a large eroded vaginal mesh into the bladder and discuss potential benefits and limitations of the technique.
Laparoscopic simultaneous bilateral adrenalectomy for testosterone‐secreting bilateral adrenal tumors
Authors: Suzuki Takahisa , Furuse Hiroshi , Kurita Yutaka , Ushiyama Tomomi , Mugiya Soichi , Ozono Seiichiro , Oki Yutaka
Published: April 2013

Laparoscopic adrenalectomy is widely accepted as a safe and minimally‐invasive procedure. Although it is a standard procedure for the surgical treatment of adrenal tumors, its simultaneous use with bilateral adrenalectomy is relatively rare. A 21‐year‐old woman was referred to Hamamatsu University School of Medicine University Hospital complaining of a deepening voice, hirsutism and secondary amenorrhea. Abdominal computed tomography showed bilateral adrenal tumors, and hormonal examinations showed that the tumors secreted excessive testosterone, resulting in virilizing symptoms. Laparoscopic simultaneous bilateral adrenalectomy was carried out. Postoperatively, serum testosterone levels immediately recovered to within the normal range. Menstruation began the month after the operation, and the hirsutism gradually regressed. This is the third reported case of bilateral virilizing adrenal tumors, and the first to be successfully treated with laparoscopic simultaneous bilateral adrenalectomy.
Solvent/Detergent Treatment of Human Plasma ‐ A Very Robust Method for Virus Inactivation. Validated Virus Safety of OCTAPLAS®
Authors: Biesert L. , Suhartono H.
Published: April 2013

OCTAPLAS® is a cell‐free standardized blood group specific human coagulation active plasma for transfusion. The viral safety is mainly based on the treatment with solvent/detergent. SD is known to irreversibly inactivate the lipid enveloped viruses including HTV 1+2, HBV and HCV and has been recommended both by European guidelines and the FDA. The potential limitation of each inactivation method should be validated according to the current EU‐guidelines CPMP/BWP/268/95 and CPMP/BWP/269/95. Our studies demonstrate that the SD method inactivates lipid enveloped viruses within a few minutes to below the limit of detection. The concentration of the SD reagents as well as several other process parameters chosen for the virus inactivation step of plasma pools of different protein and lipid composition result in a high safety margin towards the clinically relevant viruses.
Viral Safety of Blood Derivatives by Immune Neutralization
Authors: Rollag H. , Solheim B. G. , Svennevig J. L.
Published: April 2013

Despite careful donor selection and virus inactivation procedures, transmission of viruses by transfusion of blood and blood derivatives is still a threat. Outbreaks of hepatitis A among hemophiliacs having received highly purified, immune globulin depleted coagulation factor concentrates, put the importance of immune neutralization of viruses in blood derivatives in focus. Neutralizing antibodies may block several steps in the virus infection of a cell, from binding of virus to the cellular receptor to the uncoating of virus after uptake in the cell. The efficacy of antibody neutralizing activity depends on the availability and stability of the neutralizing epitopes. Hepatitis A and B viruses are very efficiently neutralized by antibodies and immune escape mutants rarely emerge. Anti‐parvovirus B19 antibodies do not fully inactivate the virus, at least in low concentrations, but may prevent development of disease. The neutralizing epitopes on hepatitis C virus and human immunodeficiency virus are located on hypervariable regions of virus membrane proteins. The effects of neutralizing antibodies are thus marginal as immune escape mutants emerge at a relatively high frequency for both viruses. The neutralizing activity of anti‐cytomegalovirus antibodies is also questionable as persons may become reinfected with cytomegolvirus despite high levels of antibodies. Plasma and plasma derivatives produced from large donor pools have the potential of being very efficient transmitters of viruses. Neutralizing antibodies are Nature's own, and very important barriers against the spread of many known and unknown viruses contaminating the plasma pools.
On The Receiving End: The Governance of the Police in Britain
Authors: Amann Ron
Published: April 2013

Based on direct observation over a five‐year period, the article paints an intimate picture of how the police in Britain are governed. It analyses the complexity of the economic and political environment in which the police have to work: the insecure funding platform; the stream of initiatives, targets and official guidelines; the delicacy of handling community sensitivities; the inherent opaqueness of the national ‘tripartite’ system of governance; and the constant challenge of making balanced judgements under conflicting pressures. The central theme that runs through the article (which follows on logically from two previous articles published in Political Quarterly) is that of a ‘managerialist’ political class, with a distinctive ideology and mode of control, trying to get a policy grip on the real world of service delivery: in this instance, policing. Unlike the previous two articles, which had a top‐down focus, the emphasis here is primarily on how the thicket looks to those who have to navigate their way through it.