bluuebunny/crossref_metadata_2025 huggingface dataset:
Geometric dependence of transport and universal behavior in three dimensional carbon nanostructures
Authors: Wang Leizhi , Yin Ming , Jaroszynski Jan , Park Ju-Hyun , Mbamalu Godwin , Datta Timir
Published: September 2016

Carbon nanostructures with the spherical voids exhibit interesting temperature and magnetic field dependent transport properties. By increasing the void size, the structures are tuned from metallic to insulating; in addition, the magnetoresistance (MR) is enhanced. Our investigation in the magnetic fields (B) up to 18 T at temperatures (T) from 250 mK to 20 K shows that at high temperatures (T > 2 K), the MR crosses over from quadratic to a non-saturating linear dependence with increasing magnetic field. Furthermore, all MR data in this temperature regime collapse onto a single curve as a universal function of B/T, following Kohler's rule. Remarkably, the MR also exhibits orientation insensitivity, i.e., it displays a response independent of the direction on the magnetic field.
Discs large homologue 1 (Dlg1) coordinates mouse oocyte polarisation during maturation
Authors: Wang Jun-Chao , Lv Hong , Wu Ke-Liang , Zhang Yun-Shan , Luo Hai-Ning , Chen Zi-Jiang
Published: September 2016

Mouse oocyte meiotic division requires the establishment of asymmetries in the oocyte before division, indicating the presence of polarity-establishing molecules. During mouse oocyte maturation proper orientation and positioning of the meiotic spindle at the oocyte cortex, as well as polarity in the oocyte cytoplasm and its oolemma, are necessary for the formation of functional haploid oocytes. Discs large homologue 1 (Dlg1) protein is a conserved protein that regulates cell polarity. In the present study, we found that Dlg1 was expressed at different stages of oocyte development. The localisation of Dlg1 during mouse oocyte maturation and its relationship with the cytoskeleton were analysed. Our data show that at the germinal vesicle stage, Dlg1 was present in the cytoplasm, prominently surrounding the germinal vesicle membrane. During maturation, Dlg1 became highly polarised by associating with the spindle and formed characteristic crescent-shaped accumulations under the cortex. Addition of nocodazole or cytochalasin B into the culture medium at different stages changed the localisation of Dlg1, indicating that the organisation of Dlg1 is a complex multi-step process and is dependent on microtubules and microfilaments. More importantly, we found that silencing of Dlg1 compromised the G2–M transition.
Imprinted and DNA methyltransferase gene expression in the endometrium during the pre- and peri-implantation period in cattle
Authors: O'Doherty A. M. , O'Shea L. C. , Sandra O. , Lonergan P. , Fair T. , Forde N.
Published: September 2016

The endometrium plays a key role in providing an optimal environment for attachment of the preimplantation embryo during the early stages of pregnancy. Investigations over the past 2 decades have demonstrated that vital epigenetic processes occur in the embryo during the preimplantation stages of development. However, few studies have investigated the potential role of imprinted genes and their associated modulators, the DNA methyltransferases (DNMTs), in the bovine endometrium during the pre- and peri-implantation period. Therefore, in the present study we examined the expression profiles of the DNMT genes (3A, 3A2 and 3B) and a panel of the most comprehensively studied imprinted genes in the endometrium of cyclic and pregnant animals. Intercaruncular (Days 5, 7, 13, 16 and 20) and caruncular (Days 16 and 20) regions were analysed for gene expression changes, with protein analysis also performed for DNMT3A, DNMT3A2 and DNMT3B on Days 16 and 20. An overall effect of day was observed for expression of several of the imprinted genes. Tissue-dependent gene expression was detected for all genes at Day 20. Differences in DNMT protein abundance were mostly observed in the intercaruncular regions of pregnant heifers at Day 16 when DNMT3A, DNMT3A2 and DNMT3B were all lower when compared with cyclic controls. At Day 20, DNMT3A2 expression was lower in the pregnant caruncular samples compared with cyclic animals. This study provides evidence that epigenetic mechanisms in the endometrium may be involved with implantation of the embryo during the early stages of pregnancy in cattle.
The role of weather, past fire and topography in crown fire occurrence in eastern Australia
Authors: Storey Michael , Price Owen , Tasker Elizabeth
Published: September 2016

We analysed the influence of weather, time since fire (TSF) and topography on the occurrence of crown fire, as mapped from satellite imagery, in 23 of the largest wildfires in dry sclerophyll forests in eastern Australia from 2002 to 2013. Fires were analysed both individually and as groups. Fire weather was the most important predictor of crown consumption. TSF (a surrogate for fuel accumulation) had complex nonlinear effects that varied among fires. Crown fire likelihood was low up to 4 years post-fire, peaked at ~10 years post-fire and then declined. There was no clear indication that recent burning became more or less effective as fire weather became more severe. Steeper slope reduced crown fire likelihood, contrary to the assumptions of common fire behaviour equations. More exposed areas (ridges and plains) had higher crown fire likelihood. Our results suggest prescribed burning to maintain an average of 10 years’ TSF may actually increase crown fire likelihood, but burning much more frequently can be effective for risk reduction. Our results also suggest the effects of weather, TSF and slope are not adequately represented in the underlying equations of most fire behaviour models, potentially leading to poor prediction of fire spread and risk.
Danger-associated peptide signaling in
Arabidopsis
requires clathrin
Authors: Ortiz-Morea Fausto Andres , Savatin Daniel V. , Dejonghe Wim , Kumar Rahul , Luo Yu , Adamowski Maciej , Van den Begin Jos , Dressano Keini , Pereira de Oliveira Guilherme , Zhao Xiuyang , Lu Qing , Madder Annemieke , Friml Jiří , Scherer de Moura Daniel , Russinova Eugenia
Published: September 2016

Significance

Plant endogenous molecules, such as the
Arabidopsis thaliana
elicitor peptides (
At
Peps), activate defense responses by means of cell surface-located receptors that serve as an excellent model to study the implications of endomembrane trafficking in plant immunity. Here we used fluorescently labeled and bioactive pep1 to probe in vivo the intracellular dynamics and the fate of the active receptor-ligand complexes in the
Arabidopsis
root meristem. We show that
At
Pep1 internalization depends on its receptors and that clathrin-mediated endocytosis is essential for
At
Pep1-induced responses.
2-(m-Azidobenzoyl)taxol binds differentially to distinct β-tubulin isotypes
Authors: Yang Chia-Ping Huang , Yap Eng-Hui , Xiao Hui , Fiser Andras , Horwitz Susan Band
Published: September 2016

Significance

β-Tubulin is a validated target for Taxol. There are seven β-tubulin isotypes present in distinct quantities in mammalian cells of different origin. Altered expression of βIII-tubulin is found in cancer cell lines and in human tumors resistant to Taxol. A tritium-labeled Taxol analog was used to determine that βIII-tubulin binds the least amount of drug, compared with other isotypes. Sequence analysis near the Taxol binding site revealed the presence of a unique Ala218 in βIII-tubulin. Molecular dynamics simulations indicated that this residue could influence the ability of Taxol to interact with its binding site. These results link drug response with the β-tubulin isotypes present in a tumor and emphasize the importance of designing Taxol analogs that specifically interact with βIII-tubulin.
Higher-order free logic and the Prior-Kaplan paradox
Authors: Bacon Andrew , Hawthorne John , Uzquiano Gabriel
Published: September 2016

The principle of universal instantiation plays a pivotal role both in the derivation of intensional paradoxes such as Prior's paradox and Kaplan's paradox and the debate between necessitism and contingentism. We outline a distinctively free logical approach to the intensional paradoxes and note how the free logical outlook allows one to distinguish two different, though allied themes in higher-order necessitism. We examine the costs of this solution and compare it with the more familiar ramificationist approaches to higher-order logic. Our assessment of both approaches is largely pessimistic, and we remain reluctantly inclined to take Prior's and Kaplan's derivations at face value.
Epistemicism and modality
Authors: Yli-Vakkuri Juhani
Published: September 2016

What kind of semantics should someone who accepts the epistemicist theory of vagueness defended in Timothy Williamson'sVagueness(1994) give a definiteness operator? To impose some interesting constraints on acceptable answers to this question, I will assume that the object language also contains a metaphysical necessity operator and a metaphysical actuality operator. I will suggest that the answer is to be found by working within a three-dimensional model theory. I will provide sketches of two ways of extracting an epistemicist semantics from that model theory, one of which I will find to be more plausible than the other.
PDB2CD: a web-based application for the generation of circular dichroism spectra from protein atomic coordinates
Authors: Mavridis Lazaros , Janes Robert W
Published: September 2016

Motivation

Circular dichroism (CD) spectroscopy is extensively utilized for determining the percentages of secondary structure content present in proteins. However, although a large contributor, secondary structure is not the only factor that influences the shape and magnitude of the CD spectrum produced. Other structural features can make contributions so an entire protein structural conformation can give rise to a CD spectrum. There is a need for an application capable of generating protein CD spectra from atomic coordinates. However, no empirically derived method to do this currently exists.

Results

PDB2CD has been created as an empirical-based approach to the generation of protein CD spectra from atomic coordinates. The method utilizes a combination of structural features within the conformation of a protein; not only its percentage secondary structure content, but also the juxtaposition of these structural components relative to one another, and the overall structure similarity of the query protein to proteins in our dataset, the SP175 dataset, the ‘gold standard’ set obtained from the Protein Circular Dichroism Data Bank (PCDDB). A significant number of the CD spectra associated with the 71 proteins in this dataset have been produced with excellent accuracy using a leave-one-out cross-validation process. The method also creates spectra in good agreement with those of a test set of 14 proteins from the PCDDB. The PDB2CD package provides a web-based, user friendly approach to enable researchers to produce CD spectra from protein atomic coordinates.

Availability and implementation

http://pdb2cd.cryst.bbk.ac.uk

Supplementary information

Supplementary data are available at Bioinformatics online.
The rheology of a growing leaf: stress-induced changes in the mechanical properties of leaves
Authors: Sahaf Michal , Sharon Eran
Published: September 2016

We study in situ the mechanics and growth of a leaf. Young Nicotiana tabacum leaves respond to applied mechanical stress by altering both their mechanical properties and the characteristics of their growth. We observed two opposite behaviours, each with its own typical magnitude and timescale. On timescales of the order of minutes, the leaf deforms in response to applied tensile stress. During this phase we found a high correlation between the applied stress field and the local strain field throughout the leaf surface. For times over 12 hours the mechanical properties of the leaf become anisotropic, making it more resilient to deformation and restoring a nearly isotropic growth field despite the highly anisotropic load. These observations suggest that remodelling of the tissue allows the leaf to respond to mechanical perturbations by changing its properties. We discuss the relevance of the observed behaviour to the growth regulation that leads to proper leaf shape during growth.
Attenuated Positive Psychotic Symptoms in Relation to Cigarette Smoking in a Nonclinical Population
Authors: Wolfe Rebecca M. , Reeves Lauren E. , Gibson Lauren E. , Cooper Shanna , Ellman Lauren M.
Published: September 2016

Introduction:

This study explored the association between cigarette smoking and attenuated positive psychotic symptoms in a young adult nonclinical sample.

Methods:

Undergraduates (N = 930), aged 18–35 years (26.3% male), completed a battery of self-report measures assessing subthreshold psychotic symptoms, cigarette smoking behavior/dependence, and drug use.

Results:

Individuals endorsing a greater number of attenuated positive psychotic symptoms were more likely to be smokers. Exploratory analyses indicated that the odds of being a smoker were two times greater for those at potential higher risk for psychosis compared with individuals at lower risk. Results were consistent after adjusting for sex and other drug use.

Conclusions:

In line with findings from psychotic populations, results suggest that attenuated positive psychotic symptoms, particularly those endorsed as distressing in a nonclinical, undergraduate population, are related to cigarette smoking.

Implications:

Even in nonclinical, undergraduate populations, subthreshold psychotic symptoms are related to cigarette smoking, and cigarette smokers are twice as likely to be considered at potentially higher risk for psychosis compared with noncigarette smokers. In summary, there may be a threshold whereby psychotic symptoms confer increased risk for nicotine consumption, with endorsement of a greater number of distressing subthreshold psychotic symptoms increasing the likelihood of cigarette use.
Imported Case of Lassa Fever in Sweden With Encephalopathy and Sensorineural Hearing Deficit
Authors: Grahn Anna , Bråve Andreas , Lagging Martin , Dotevall Leif , Ekqvist David , Hammarström Helena , Karlberg Helen , Lagerqvist Nina , Sansone Martina , Tegnell Anders , Ulleryd Peter , Studahl Marie
Published: September 2016

We describe an imported case of Lassa fever with both encephalopathy and bilateral sensorineural hearing deficit. Absence of fever during hospitalization, initially nonspecific symptoms, and onset of hearing deficit in a late stage of disease probably contributed to delayed diagnosis (14 days after admittance to hospital). The pathogenesis of neurological manifestations of Lassa fever is poorly understood and no specific treatment was given. A total of 118 personnel had close contact with the patient, but no secondary cases occurred. This case highlights the importance of considering Lassa fever as a differential diagnosis in patients with recent travel to endemic areas.
MAXI observations of long X-ray bursts
Authors: Serino Motoko , Iwakiri Wataru , Tamagawa Toru , Sakamoto Takanori , Nakahira Satoshi , Matsuoka Masaru , Yamaoka Kazutaka , Negoro Hitoshi
Published: September 2016

We report nine long X-ray bursts from neutron stars, detected with the Monitor of All-sky X-ray Image (MAXI). Some of these bursts lasted for hours, and hence are qualified as superbursts, which are prolonged thermonuclear flashes on neutron stars and are relatively rare events. MAXI observes roughly 85% of the whole sky every 92 minutes in the 2–20 keV energy band, and has detected nine bursts with a long e-folding decay time, ranging from 0.27 to 5.2 hr, since its launch in 2009 August until 2015 August. The majority of the nine events were found to originate from transient X-ray sources. The persistent luminosities of the sources, when these prolonged bursts were observed, were lower than 1% of the Eddington luminosity for five of them and lower than 20% for the rest. This trend is contrastive to the 18 superbursts observed before MAXI, all but two of which originated from bright persistent sources. The distribution of the total emitted energy, i.e., the product of e-folding time and luminosity, of these bursts clusters around 1041–1042 erg, whereas both the e-folding time and luminosity ranges for an order of magnitude. Among the nine events, two were from 4U 1850−086 during phases of relatively low persistent flux, whereas it usually exhibits standard short X-ray bursts during outbursts.
Breaking the Silence: Time to Talk About Race and Racism
Authors: Acosta David , Ackerman-Barger Kupiri
Published: September 2016

Recent events in the United States have catalyzed the need for all educators to begin paying attention to and discovering ways to dialogue about race. No longer can health professions (HP) educators ignore or avoid these difficult conversations. HP students are now demanding them. Cultural sensitivity and unconscious bias training are not enough. Good will and good intentions are not enough. Current faculty development paradigms are no longer sufficient to meet the educational challenges of delving into issues of race, power, privilege, identity, and social justice.

Engaging in such conversations, however, can be overwhelmingly stressful for untrained faculty. The authors argue that before any curriculum on race and racism can be developed for HP students, and before faculty members can begin facilitating conversations about race and racism, faculty must receive proper training through intense and introspective faculty development. Training should cover how best to engage in, sustain, and deepen interracial dialogue on difficult topics such as race and racism within academic health centers (AHCs). If such faculty development training—in how to conduct interracial dialogues on race, racism, oppression, and the invisibility of privilege—is made standard at all AHCs, HP educators might be poised to actualize the real benefits of open dialogue and change.
Hemodynamic Effect of Different Doses of Fluids for a Fluid Challenge: A Quasi-Randomized Controlled Study
Authors: Aya Hollmann D. , Rhodes Andrew , Chis Ster Irina , Fletcher Nick , Grounds R. Michael , Cecconi Maurizio
Published: September 2016

Objective:

The objectives of this study are to determine what is the minimal volume required to perform an effective fluid challenge and to investigate how different doses of IV fluids in an fluid challenge affect the changes in cardiac output and the proportion of responders and nonresponders.

Design:

Quasi-randomized controlled trial.

Setting:

Cardiothoracic ICU, tertiary university hospital.

Patients:

Eighty postcardiac surgery patients.

Intervention:

IV infusion of 1, 2, 3, or 4 mL/Kg (body weight) of crystalloid over 5 minutes.

Measurements and Main Results:

Mean systemic filling pressure measured using the transient stop-flow arm arterial-venous equilibrium pressure, arterial and central venous pressure, cardiac output (LiDCOplus; LiDCO, Cambridge, United Kingdom), and heart rate. The groups were well matched with respect to demographic and baseline physiologic variables. The proportion of responders increased from 20% in the group of 1 mL/kg to 65% in the group of 4 mL/kg (p = 0.04). The predicted minimal volume required for an fluid challenge was between 321 and 509 mL. Only 4 mL/Kg increases transient stop-flow arm arterial-venous equilibrium pressure beyond the limits of precision and was significantly associated with a positive response (odds ratio, 7.73; 95% CI, 1.78–31.04).

Conclusion:

The doses of fluids used for an fluid challenge modify the proportions of responders in postoperative patients. A dose of 4 mL/Kg increases transient stop-flow arm arterial-venous equilibrium pressure and reliably detects responders and nonresponders.
Cysticercosis of the Pectoralis Major: A Case Report and Review of Literature
Authors: Chauhan Sushila , Singh Gagandeep , Khan Imran
Published: September 2016

Cysticercosis is a condition caused by the encysted larval form of Taenia solium (pork tapeworm). The commonest system affected is the central nervous system. Symptomatic primary muscle involvement is a rare phenomenon. We present a case of a 19-year-old male who presented with a solitary cystic swelling in the right infraclavicular area. Magnetic resonance imaging revealed a cystic mass in the right pectoralis major muscle. The cyst was excised and submitted for histopathology. The diagnosis of cysticercosis was confirmed on histopathology of the excised cyst.
Fewer Revisions in Abdominal-based Free Flaps than Latissimus Dorsi Breast Reconstruction after Radiation
Authors: Hanson Summer E. , Smith Benjamin D. , Liu Jun , Robb Geoffrey L. , Kronowitz Steven J. , Garvey Patrick B.
Published: September 2016

Background:

The most commonly chosen flaps for delayed breast reconstruction after postmastectomy radiation therapy (PMRT) are abdominal-based free flaps (ABFFs) and pedicled latissimus dorsi (LD) musculocutaneous flaps. The short-and long-term advantages and disadvantages of delayed ABFFs versus LD flaps after PMRT remain unclear. We hypothesized that after PMRT, ABFFs would result in fewer postoperative complications and a lower incidence of revision surgery than LD flaps.

Methods:

We retrospectively reviewed a prospectively maintained database of consecutive patients who underwent unilateral, delayed breast reconstruction after PMRT using ABFFs or pedicled LD flaps with implants at the MD Anderson Cancer Center between January 1, 2001, and December 31, 2011. We compared outcomes and additional surgeries required between the 2 groups. Univariate and multivariate logistic regression modeling analyzed the relationships between patient and reconstruction characteristics and postoperative outcomes.

Results:

A total of 139 consecutive patients’ breast reconstructions were evaluated: 101 ABFFs (72.7%) versus 38 LDs (27.3%). Average follow-up was similar for ABFF and LD reconstructions. Although ABFF and LD reconstructions experienced similar rates of overall (30.7% vs 23.7%, respectively; P = 0.53), donor-site (8.91% vs 5.13%, respectively; P = 0.48), and flap (20.7% vs 17.9%, respectively; P = 0.37) complications, the LD reconstructions required more additional surgeries (92.1% vs 67.3%; P < 0.001). Furthermore, LDs required more revision surgeries more than 1 year after reconstruction (37.1% vs 14.7%; P = 0.02).

Conclusion:

Although early complication rates were similar for both types of reconstructions, ABFFs seem to have the advantage of providing a more durable result that required fewer revision surgeries in the long term.
Shoulder Dystocia: Quality, Safety, and Risk Management Considerations
Authors: MONI SAILA , LEE COLLEEN , GOFFMAN DENA
Published: September 2016

Shoulder dystocia is a term that evokes terror and fear among many physicians, midwives, and health care providers as they recollect at least 1 episode of shoulder dystocia in their careers. Shoulder dystocia can result in significant maternal and neonatal complications. Because shoulder dystocia is an urgent, unanticipated, and uncommon event with potentially catastrophic consequences, all practitioners and health care teams must be well-trained to manage this obstetric emergency. Preparation for shoulder dystocia in a systematic way, through standardization of process, practicing team-training and communication, along with technical skills, through simulation education and ongoing quality improvement initiatives will result in improved outcomes.
HORIZONTAL RIDGE AS A POSTERIOR POLE FINDING IN A HIGHLY MYOPIC EYE WITH DOME-SHAPED MACULA
Authors: Liang I Chia
Published: September 2016

Purpose:

This article describes a case with a highly myopic eye and a posterior pole with ridge-like lesions.

Methods:

Case report.

Results:

A 72-year-old man with unilateral high myopia showed poor vision and an extremely elongated axial length in his right eye, but normal vision and normal axial length in his left eye. He was examined using fundus examination and optical coherence tomography, and revealed to have dome-shaped macula with two horizontal ridges connecting the optic disc and the macula in his highly-myopic eye.

Conclusion:

The findings suggest that a dome-shaped macula may not be limited to the macula area, but may involve the whole posterior pole and is potentially involved in the elongation of highly myopic eyeballs.
WHY THE DOTS ARE BLACK ONLY IN THE LATE PHASE OF THE INDOCYANINE GREEN ANGIOGRAPHY IN MULTIPLE EVANESCENT WHITE DOT SYNDROME
Authors: Gaudric Alain , Mrejen Sarah
Published: September 2016

Purpose:

To determine what retinal layer is primarily involved in multiple evanescent white dot syndrome compared with acute posterior multifocal placoid pigment epitheliopathy using multimodal imaging including indocyanine green angiography.

Methods:

Color fundus photographs and fluorescein angiography, ICGA and spectral domain optical coherence tomography images of two typical acute cases, one of acute posterior multifocal placoid pigment epitheliopathy and one of multiple evanescent white dot syndrome, were assessed and compared.

Results:

In both diseases, white plaques or dots were seen at the posterior pole. The hypofluorescence of acute posterior multifocal placoid pigment epitheliopathy in the early phase of the fluorescein angiography and throughout the ICGA sequence suggested a multifocal choroidal hypoperfusion as the cause of the opacification of the outer retina corresponding to its hyper-reflectivity on spectral domain optical coherence tomography. In multiple evanescent white dot syndrome, there was no choroidal filling defect and the white spots were silent in the early phase of the ICGA, whereas they became black only in the late phase. The outer retina was also altered at the spots.

Conclusion:

In multiple evanescent white dot syndrome, the late hypofluorescence of the white spots on ICGA was likely due to the absence of ICG uptake by a damaged retinal pigment epithelium. Multiple evanescent white dot syndrome seems as a primary reversible nondestructive retinal pigment epitheliopathy, whereas acute posterior multifocal placoid pigment epitheliopathy is a true choroidopathy.
The Effect of Laser Photocoagulation on Intraocular Pressure in Premature Infants With Retinopathy of Prematurity
Authors: Erginturk Acar Damla , Acar Ugur , Tunay Zuhal Ozen , Ozdemir Ozdemir
Published: September 2016

Purpose:

To evaluate the effects of diode laser treatment on intraocular pressure (IOP) of premature infants with retinopathy of prematurity (ROP).

Patients and Methods:

The premature infants who underwent retinal laser photocoagulation therapy for ROP, and gestational age–matched, birth weight–matched, and sex-matched premature infants with ROP which recovered spontaneously without any treatment were enrolled into the study. Anterior segment examination and longitudinal IOP and central corneal thickness measurements were performed 5 times as follows: 1 day before the laser treatment (T0), and 24 hours (T1), 1 week (T2), 1 month (T3), and 3 months (T4) after the laser treatment. Premature infants who experienced any complication related to the laser treatment were excluded from the study.

Results:

Laser treated 67 premature infants and 70 premature infants in control group met inclusion criteria. Significant linear decreases in IOP and central corneal thickness values were measured throughout the study period for both groups (both, P<0.001). These changes were similar in 2 groups. There was a statistically insignificantly (P=0.999) and transient increase in the mean IOP value in the laser-treated group 24 hours after laser treatment. None of the patients in the laser-treated group experienced a shallow anterior chamber or a remarkable IOP elevation.

Conclusions:

Diode laser treatment for ROP was safe, and did not raise the IOP of premature infants.
Refractive Outcome of Cataract Surgery in Eyes With Prior Trabeculectomy: Risk Factors for Postoperative Myopia
Authors: Yeh Oliver L. , Bojikian Karine D. , Slabaugh Mark A. , Chen Philip P.
Published: September 2016

Purpose:

To examine refractive outcomes after phacoemulsification in eyes with prior trabeculectomy.

Design:

Retrospective observational case-control study

Methods:

Comparison of eyes of glaucoma patients undergoing cataract surgery after trabeculectomy (study group) with a matched group with medically controlled glaucoma (control group). Laser interferometry was used to obtain ocular biometry. We measured the difference between the expected and actual postoperative refraction using third-generation and fourth-generation intraocular lens (IOL) prediction formulae (Haigis, Holladay 2, Hoffer Q, and SRK-T). A residual difference of >1.0 D of hyperopia or myopia was considered a “refractive surprise.”

Results:

In total, 86 eyes (85 patients) were included, including 23 eyes (22 patients) in the study group and 63 eyes (63 patients) in the control group. The mean follow-up was 12.2±4.1 months. Eyes (n=13) with trabeculectomy and a preoperative intraocular pressure (IOP)≤9 mm Hg had significantly more large myopic surprises than the control group for all IOL formulae (P=0.015 Haigis, P=0.003 Holladay 2, P=0.004 Hoffer Q, P=0.003 SRK-T). Eyes (n=10) with trabeculectomy and preoperative IOP>9 mm Hg, however, did not have significantly more myopic errors than the control (P>0.05, all formulae). An “IOP spike” defined as a >50% rise in IOP from baseline within 1 month of cataract surgery in the subgroup with preoperative IOP≤9 mm Hg (n=8) was associated with increased risk of large myopic surprise (3/8 subset vs. 1/63 control eyes for all formulae; P=0.004 Haigis, P=0.004 Holladay 2, P=0.001 Hoffer Q, P=0.004 SRK-T) as well as for large myopic and hyperopic surprises overall (4/8 subset vs. ≤2/63 depending upon formulae; all P≤0.001).

Conclusions:

Low posttrabeculectomy IOP (≤9 mm Hg) is a risk factor for significant myopic surprise when undergoing subsequent cataract surgery despite using laser interferometry to measure ocular biometry and later generation formulae to determine IOL power. In addition, an IOP spike was associated with a 50% risk for large refractive surprise in this low IOP group.
Methylmalonic and propionic acidemias: clinical management update
Authors: Fraser Jamie L. , Venditti Charles P.
Published: September 2016

Purpose of review

Recent clinical studies and management guidelines for the treatment of the organic acidopathies methylmalonic acidemia (MMA) and propionic acidemia address the scope of interventions to maximize health and quality of life. Unfortunately, these disorders continue to cause significant morbidity and mortality due to acute and chronic systemic and end-organ injury.

Recent findings

Dietary management with medical foods has been a mainstay of therapy for decades, yet well controlled patients can manifest growth, development, cardiac, ophthalmological, renal, and neurological complications. Patients with organic acidopathies suffer metabolic brain injury that targets specific regions of the basal ganglia in a distinctive pattern, and these injuries may occur even with optimal management during metabolic stress. Liver transplantation has improved quality of life and metabolic stability, yet transplantation in this population does not entirely prevent brain injury or the development of optic neuropathy and cardiac disease.

Management guidelines should identify necessary screening for patients with methylmalonic acidemia and propionic acidemia, and improve anticipatory management of progressive end-organ disease. Liver transplantation improves overall metabolic control, but injury to nonregenerative tissues may not be mitigated. Continued use of medical foods in these patients requires prospective studies to demonstrate evidence of benefit in a controlled manner.
Patient Safety During Chest Drain Insertion—A Survey of Current Practice
Authors: Villanueva Claudia , Doyle Mathew , Parikh Roneil , Manganas Con
Published: September 2016

Objectives

The aim of this study was to identify the degree of awareness of the current guidelines and common practices for pleural drain insertion.

Methods

A 10-item questionnaire was sent electronically to junior physicians from 4 different hospitals in the South Eastern Sydney and Illawarra Shoalhaven Local Health District. Participants were asked to give their level of experience and management practices for chest drain insertion.

Results

A total of 94 junior medical officers from 4 hospitals in the district completed the survey. More than 20% had never inserted a chest drain at the time; 72% had primarily learned from bedside teaching and peer learning, but 11% had no training at all. More than 50% of physicians felt that the biggest threat to the procedure was their own lack of confidence for drain insertion. Despite current guidelines, 25% insert chest drains routinely without the aid of ultrasound. A third of interviewees were aware of local guidelines but had not read them. Most physicians (86%) believe that formal standardized training should be available for junior physicians.

Conclusions

Our findings demonstrate the ongoing need for improved procedural training in chest drain insertion, with emphasis on mandatory thoracic ultrasound. We consider it important to continue to raise concern and awareness that chest drain insertion is not a harmless procedure, and further physician procedural competence is required.
Brief Report: Informing Strategies to Build PrEP Capacity Among San Francisco Bay Area Clinicians
Authors: Bacon Oliver , Gonzalez Rafael , Andrew Erin , Potter Michael B. , Iñiguez James R. , Cohen Stephanie E. , Liu Albert Y. , Fuchs Jonathan D.
Published: September 2016

A large pool of clinicians are needed to meet the growing demand for HIV preexposure prophylaxis. We surveyed a mixed group of HIV specialists and nonspecialists in the San Francisco Bay Area to determine their attitudes toward and training needs regarding prescribing preexposure prophylaxis to persons at increased risk of HIV infection. Willingness to prescribe was associated with experience in caring for HIV-infected patients (adjusted odds ratio 4.76, 95% confidence interval: 1.43 to 15.76, P = 0.01). Desire for further training was associated with concerns about drug resistance (P = 0.04) and side effects (P = 0.04) and was more common among noninfectious disease specialists. Clinicians favored online and in-person training methods.
Detection of Calcium Crystals in Knee Osteoarthritis Synovial Fluid
Authors: Frallonardo Paola , Oliviero Francesca , Peruzzo Luca , Tauro Leonardo , Scanu Anna , Galozzi Paola , Ramonda Roberta , Punzi Leonardo
Published: September 2016

Background

The identification of calcium crystals in synovial fluid (SF) of patients with osteoarthritis (OA) represents an important step in understanding the role of these crystals in synovial inflammation and disease progression.

Objectives

This study aimed to investigate the presence of calcium pyrophosphate (CPP) and basic calcium phosphate (BCP) crystals in SF collected from patients with symptomatic knee OA by scanning electron microscopy (SEM) coupled to x-ray energy dispersive spectroscopy, compensated polarized light microscopy (CPLM), and alizarin red staining.

Methods

Seventy-four patients with knee OA were included in the study. Synovial fluid samples were collected after arthrocentesis and examined under CPLM for the assessment of CPP crystals. Basic calcium phosphate crystals were evaluated by alizarin red staining. All the samples were examined by SEM. The concordance between the 2 techniques was evaluated by Cohen κ agreement coefficient.

Results

Calcium pyrophosphate and BCP crystals were found, respectively, in 23 (31.1%) and 13 (17.5%) of 74 OA SFs by SEM analysis. Calcium pyrophosphate crystals were identified in 23 (31.1%) of 74 samples by CPLM, whereas BCP crystals were suspected in 27 (36.4%) of 74 samples. According to κ coefficient, the concordance between CPLM and SEM was 0.83 for CPP, and that between alizarin red and SEM was 0.68 for BCP.

Conclusions

The results of our study showed a high level of concordance between the 2 microscope techniques as regards CPP crystal identification and a lower agreement for BCP crystals. Although this finding highlights the difficulty in identifying BCP crystals by alizarin red staining, the use of SEM remains unsuitable to apply in the clinical setting. Because of the in vitro inflammatory effect of BCP crystals, further work on their analysis in SF could provide important information about the OA process.
Systemic Lupus Erythematosus Does Not Increase Risk of Adverse Events in the First 6 Months After Total Knee Arthroplasty
Authors: Fein Arielle W. , Figgie Caroline A. , Dodds Taylor R. , Wright-Chisem Joshua , Parks Michael L. , Mandl Lisa A. , Su Edwin P. , Salmon Jane E. , Mayman David J. , Lee Yuo-Yu , Figgie Mark P. , Goodman Susan M.
Published: September 2016

Background

Increasing numbers of patients with systemic lupus erythematosus (SLE) are undergoing total knee arthroplasty (TKA). Whether postsurgical adverse events (AEs) are higher in patients with SLE than patients with osteoarthritis (OA) is unknown.

Objectives

This study aims to compare AEs within 6 months of TKA.

Methods

Patients in a single institution’s arthroplasty and SLE registries who underwent TKA from 2007 to 2014 were eligible. SLE cases were matched 1:2 to OA on age, sex, year of TKA, and procedure type. AEs were collected through chart review and registry responses. Baseline characteristics were compared and regression analysis performed to determine predictors of AEs.

Results

Fifty-two SLE TKA were matched to 104 OA TKA. There was no difference in follow-up between groups. SLE patients had more comorbidities (≥1 Charlson-Deyo comorbidity: SLE 38.4% vs. OA 17.3%; P-value < 0.001) and steroid use (preoperative [SLE 28.8% vs. OA 1.9%, P-value < 0.001] and perioperative “stress-dose” [30.8% vs. 2.9%, P-value = 0.01]). SLE patients did not experience more major (SLE 25.0% vs. OA 19.2%; P-value = 0.41), minor (15.4% vs. 10.6%; P-value = 0.39), or total (38.5% vs. 27.9%; P-value = 0.18) AEs. AEs were not increased among patients on stress-dose steroids. In a multiple logistic regression analysis controlling for comorbidities and diagnosis, neither SLE (OR 1.61, 95% CI 0.74–3.50) nor >1 comorbidity (OR 1.05, 95% CI 0.46–2.39) was an independent risk factor for AEs.

Conclusion

SLE is not an independent risk factor for increased AEs 6 months after TKA. Stress-dose steroid use does not heighten AE risk. These findings should inform recommendations for SLE patients considering TKA.
Titanium Surgical Tacks: Are They Safe? Do They Work?
Authors: Shatkin-Margolis Abigail , Merchant Maqdooda , Margulies Rebecca U. , Ramm Olga
Published: September 2016

Objectives

Minimally invasive approaches to sacrocolpopexy have transformed it into a primary procedure for treatment of pelvic organ prolapse. Certain modifications are commonly used to facilitate the laparoscopic approach, but have not yet been widely studied. In this study, we investigated the efficacy and safety of titanium surgical tacks for the attachment of mesh to the anterior longitudinal ligament in laparoscopic sacrocolpopexy.

Methods

This retrospective cohort study involved all patients within 1 health care system who underwent laparoscopic sacrocolpopexy between January 2009 and December 2012. Each medical record was reviewed and abstracted.

Results

Of the 231 patients included in our study, 190 (82%) had titanium surgical tacks, and 41 (18%) had suture for mesh attachment to the anterior longitudinal ligament. The demographics of the 2 subgroups as well as concomitantly performed procedures were comparable. There was no significant difference found between the 2 cohorts in regards to operative time, estimated blood loss, complication rates, rate of recurrent pelvic organ prolapse symptoms or the rate of reoperation for pelvic organ prolapse.

Conclusions

Surgical tacks are a safe alternative to suture for the attachment of mesh to the anterior longitudinal ligament in laparoscopic sacrocolpopexy. Although we saw no advantage to using tacks over suture, tacking the mesh to the anterior longitudinal ligament may make the laparoscopic approach more accessible to a wider range of gynecologic surgeons. Further studies about the long-term impact of surgical tacks on bone and disk disease are needed.
The scientific, the literary and the popular: Commerce and the reimagining of the scientific journal in Britain, 1813–1825
Authors: Topham Jonathan R.
Published: September 2016

As scientists question the recent dominance of the scientific journal, the varied richness of its past offers useful materials for reflection. This paper examines four innovative journals founded and run by leading publishers and men of science in the 1810s and 1820s, which contributed to a significant reimagining of the form. Relying on a new distinction between the ‘literary’ and the ‘scientific’ to define their market, those who produced the journals intended to maximize their readership and profits by making them to some extent ‘popular’. While these attempts ended in commercial failure, not least because of the rapidly diversifying periodical market in which they operated, their history makes clear the important role that commerce has played both in defining the purposes and audiences of scientific journals and in the conceptualization of the scientific project. It also informs the ongoing debate concerning how the multiple audiences for science can be addressed in ways that are commercially and practically viable.
Monocular blur alters the tuning characteristics of stereopsis for spatial frequency and size
Authors: Li Roger W. , So Kayee , Wu Thomas H. , Craven Ashley P. , Tran Truyet T. , Gustafson Kevin M. , Levi Dennis M.
Published: September 2016

Our sense of depth perception is mediated by spatial filters at different scales in the visual brain; low spatial frequency channels provide the basis for coarse stereopsis, whereas high spatial frequency channels provide for fine stereopsis. It is well established that monocular blurring of vision results in decreased stereoacuity. However, previous studies have used tests that are broadband in their spatial frequency content. It is not yet entirely clear how the processing of stereopsis in different spatial frequency channels is altered in response to binocular input imbalance. Here, we applied a new stereoacuity test based on narrow-band Gabor stimuli. By manipulating the carrier spatial frequency, we were able to reveal the spatial frequency tuning of stereopsis, spanning from coarse to fine, under blurred conditions. Our findings show that increasing monocular blur elevates stereoacuity thresholds ‘selectively’ at high spatial frequencies, gradually shifting the optimum frequency to lower spatial frequencies. Surprisingly, stereopsis for low frequency targets was only mildly affected even with an acuity difference of eight lines on a standard letter chart. Furthermore, we examined the effect of monocular blur on the size tuning function of stereopsis. The clinical implications of these findings are discussed.
Acidification and
γ
-aminobutyric acid independently alter kairomone-induced behaviour
Authors: Charpentier Corie L. , Cohen Jonathan H.
Published: September 2016

Exposure to high
p
CO
2
or low pH alters sensation and behaviour in many marine animals. We show that crab larvae lose their ability to detect and/or process predator kairomones after exposure to low pH over a time scale relevant to diel pH cycles in coastal environments. Previous work suggests that acidification affects sensation and behaviour through altered neural function, specifically the action of
γ
-aminobutyric acid (GABA), because a GABA antagonist, gabazine, restores the original behaviour. Here, however, gabazine resulted in a loss of kairomone detection/processing, regardless of pH. Our results also suggest that GABAergic signalling is necessary for kairomone identification in these larvae. Hence, the mechanism for the observed pH effect varies from the original GABA hypothesis. Furthermore, we suggest that this pH effect is adaptive under diel-cycling pH.
Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots
Authors: Cox S. L. , Miller P. I. , Embling C. B. , Scales K. L. , Bicknell A. W. J. , Hosegood P. J. , Morgan G. , Ingram S. N. , Votier S. C.
Published: September 2016

Oceanic fronts are key habitats for a diverse range of marine predators, yet how they influence fine-scale foraging behaviour is poorly understood. Here, we investigated the dive behaviour of northern gannets
Morus bassanus
in relation to shelf-sea fronts. We GPS (global positioning system) tracked 53 breeding birds and examined the relationship between 1901 foraging dives (from time-depth recorders) and thermal fronts (identified via Earth Observation composite front mapping) in the Celtic Sea, Northeast Atlantic. We (i) used a habitat-use availability analysis to determine whether gannets preferentially dived at fronts, and (ii) compared dive characteristics in relation to fronts to investigate the functional significance of these oceanographic features. We found that relationships between gannet dive probabilities and fronts varied by frontal metric and sex. While both sexes were more likely to dive in the presence of seasonally persistent fronts, links to more ephemeral features were less clear. Here, males were positively correlated with distance to front and cross-front gradient strength, with the reverse for females. Both sexes performed two dive strategies: shallow V-shaped plunge dives with little or no active swim phase (92% of dives) and deeper U-shaped dives with an active pursuit phase of at least 3 s (8% of dives). When foraging around fronts, gannets were half as likely to engage in U-shaped dives compared with V-shaped dives, independent of sex. Moreover, V-shaped dive durations were significantly shortened around fronts. These behavioural responses support the assertion that fronts are important foraging habitats for marine predators, and suggest a possible mechanistic link between the two in terms of dive behaviour. This research also emphasizes the importance of cross-disciplinary research when attempting to understand marine ecosystems.
Colour thresholds in a coral reef fish
Authors: Champ C. M. , Vorobyev M. , Marshall N. J.
Published: September 2016

Coral reef fishes are among the most colourful animals in the world. Given the diversity of lifestyles and habitats on the reef, it is probable that in many instances coloration is a compromise between crypsis and communication. However, human observation of this coloration is biased by our primate visual system. Most animals have visual systems that are ‘tuned’ differently to humans; optimized for different parts of the visible spectrum. To understand reef fish colours, we need to reconstruct the appearance of colourful patterns and backgrounds as they are seen through the eyes of fish. Here, the coral reef associated triggerfish,
Rhinecanthus aculeatus
, was tested behaviourally to determine the limits of its colour vision. This is the first demonstration of behavioural colour discrimination thresholds in a coral reef species and is a critical step in our understanding of communication and speciation in this vibrant colourful habitat. Fish were trained to discriminate between a reward colour stimulus and series of non-reward colour stimuli and the discrimination thresholds were found to correspond well with predictions based on the receptor noise limited visual model and anatomy of the eye. Colour discrimination abilities of both reef fish and a variety of animals can therefore now be predicted using the parameters described here.