bluuebunny/crossref_metadata_2025 huggingface dataset:
Increasing atmospheric [CO2] from glacial to future concentrations affects drought tolerance via impacts on leaves, xylem and their integrated function
Authors: Medeiros Juliana S. , Ward Joy K.
Published: May 2013

Changes in atmospheric carbon dioxide concentration ([CO2]) affect plant carbon/water tradeoffs, with implications for drought tolerance. Leaf‐level studies often indicate that drought tolerance may increase with rising [CO2], but integrated leaf and xylem responses are not well understood in this respect. In addition, the influence of the low [CO2] of the last glacial period on drought tolerance and xylem properties is not well understood.

We investigated the interactive effects of a broad range of [CO2] and plant water potentials on leaf function, xylem structure and function and the integration of leaf and xylem function in Phaseolus vulgaris.

Elevated [CO2] decreased vessel implosion strength, reduced conduit‐specific hydraulic conductance, and compromised leaf‐specific xylem hydraulic conductance under moderate drought. By contrast, at glacial [CO2], transpiration was maintained under moderate drought via greater conduit‐specific and leaf‐specific hydraulic conductance in association with increased vessel implosion strength.

Our study involving the integration of leaf and xylem responses suggests that increasing [CO2] does not improve drought tolerance. We show that, under glacial conditions, changes in leaf and xylem properties could increase drought tolerance, while under future conditions, greater productivity may only occur when higher water use can be accommodated.
Species–area relationships and extinction forecasts
Authors: Halley John M. , Sgardeli Vasiliki , Monokrousos Nikolaos
Published: May 2013

The species–area relationship (SAR) predicts that smaller areas contain fewer species. This is the basis of the SAR method that has been used to forecast large numbers of species committed to extinction every year due to deforestation. The method has a number of issues that must be handled with care to avoid error. These include the functional form of the SAR, the choice of equation parameters, the sampling procedure used, extinction debt, and forest regeneration. Concerns about the accuracy of the SAR technique often cite errors not much larger than the natural scatter of the SAR itself. Such errors do not undermine the credibility of forecasts predicting large numbers of extinctions, although they may be a serious obstacle in other SAR applications. Very large errors can arise from misinterpretation of extinction debt, inappropriate functional form, and ignoring forest regeneration. Major challenges remain to understand better the relationship between sampling protocol and the functional form of SARs and the dynamics of relaxation, especially in continental areas, and to widen the testing of extinction forecasts.
Systemic use of non‐biologic corticosteroids in orofacial diseases
Authors: Georgakopoulou EA , Scully C
Published: May 2013

Systemic non‐biologic agents have long been in clinical use in medicine – often with considerable efficacy, albeit with some adverse effects – as with all medications. With the advent of biologic agents, all of which currently are restricted to systemic use, there is a growing need to ensure which agents have the better therapeutic ratio. The non‐biologic agents (NBAs) include a range of agents, most especially the corticosteroids (corticosteroids). This study reviews the corticosteroids in systemic use in management of orofacial mucocutaneous diseases; subsequent studies discuss corticosteroid‐sparing agents used in the management of orofacial diseases, such as calcineurin inhibitors used to produce immunosuppression; purine synthetase inhibitors; and cytotoxic and other immunomodulatory agents.
Influence of periodic vs continuous daily bright light exposure on development of experimental myopia in the chick
Authors: Backhouse Simon , Collins Andrew V , Phillips John R
Published: May 2013

Purpose

In children, time spent outdoors has a protective effect against myopia development. In animal models, bright light reduces the development of experimental myopia. This study investigates how an increase in daily light exposure, presented either continuously during the day or periodically at different times of day, influences the development of experimental myopia in the chick.

Methods

Myopia was induced in Cobb Chicks (Gallus domesticus) by monocular deprivation (MD) of form vision with a translucent diffuser for 3 days (from 4 days of age) under a 12:12 light: dark cycle. MD control chicks were exposed to constant 300 lux (n = 11) during the light period. MD treatment groups received either constant 2000 lux (n = 11) during the light period or 300 lux for 10 h with a 2 h period of bright light (10 000 lux), either in the morning (n = 10), midday (n = 10) or evening (n = 10), giving the same total daily light exposure as the 2000 lux group. After 3 days of MD, refractive status, corneal curvature and axial eye dimensions were measured for all eyes under anaesthesia.

Results

Myopia in the constant 2000 lux group (−4.94 ± 1.21 D) was significantly less than in the 300 lux control group (−9.73 ± 0.96 D; p = 0.022). However, compared to the 300 lux control group, 2 h periods of 10 000 lux did not produce significant effects on refraction when presented either in the morning (−9.98 ± 0.85; p = 1.00), midday (−8.00 ± 1.26; p = 0.80), or evening (−13.14 ± 1.16 D; p = 0.20), although significantly less myopia was induced in the midday group compared to the evening group (p = 0.018). Orthogonal regression showed that myopia development was matched by changes in vitreous chamber depth (R2 = 0.69; p < 0.0001).

Conclusions

In chicks, an increase in daily light exposure continuously during the day is more effective at inhibiting myopia than adding an equivalent dose within a 2 h period of bright light. A weak time‐of‐day effect also appears to be present in the response to bright light exposure. Our results suggest that future light‐based myopia therapies in humans may be more effective if light levels are increased over the whole day, rather than through short periods of bright light exposure.
Automatic detection of modal spacing (Yellott's ring) in adaptive optics scanning light ophthalmoscope images
Authors: Cooper Robert F , Langlo Christopher S , Dubra Alfredo , Carroll Joseph
Published: May 2013

Purpose

An impediment for the clinical utilisation of ophthalmic adaptive optics imaging systems is the automated assessment of photoreceptor mosaic integrity. Here we propose a fully automated algorithm for estimating photoreceptor density based on the radius of Yellott's ring.

Methods

The discrete Fourier transform (DFT) was used to obtain the power spectrum for a series of images of the human photoreceptor mosaic. Cell spacing is estimated by least‐square fitting an annular pattern with a Gaussian cross section to the power spectrum; the radius of the resulting annulus provides an estimate of the modal spacing of the photoreceptors in the retinal image. The intrasession repeatability of the cone density estimates from the algorithm was evaluated, and the accuracy of the algorithm was validated against direct count estimates from a previous study. Accuracy in the presence of multiple cell types and disruptions in the mosaic was examined using images from four patients with retinal pathology and perifoveal images from two subjects with normal vision.

Results

Intrasession repeatability of the power spectrum method was comparable to a fully automated direct counting algorithm, but worse than that for the manually adjusted direct count values. In images of the normal parafoveal cone mosaic, we find good agreement between the power‐spectrum derived density and that from the direct counting algorithm. In diseased eyes, the power spectrum method is insensitive to photoreceptor loss, with cone density estimates overestimating the density determined with direct counting. The automated power spectrum method also produced unreliable estimates of rod and cone density in perifoveal images of the photoreceptor mosaic, though manual correction of the initial algorithm output results in density estimates in better agreement with direct count values.

Conclusions

We developed and validated an automated algorithm based on the power spectrum for extracting estimates of cone spacing, from which estimates of density can be derived. This approach may be used to estimate cone density in images where not every single cone is visible, though caution is needed, as this robustness becomes a weakness when dealing with images from patients with some retinal diseases. This study represents an important first step in carefully assessing the relative utility of metrics for analysing the photoreceptor mosaic, and similar analyses of other metrics/algorithms are needed.
The Arabidopsis GIBBERELLIN METHYL TRANSFERASE 1 suppresses gibberellin activity, reduces whole‐plant transpiration and promotes drought tolerance in transgenic tomato
Authors: NIR IDO , MOSHELION MENACHEM , WEISS DAVID
Published: May 2013

Previous studies have shown that reduced gibberellin (GA) level or signal promotes plant tolerance to environmental stresses, including drought, but the underlying mechanism is not yet clear. Here we studied the effects of reduced levels of active GAs on tomato (Solanum lycopersicum) plant tolerance to drought as well as the mechanism responsible for these effects. To reduce the levels of active GAs, we generated transgenic tomato overexpressing the Arabidopsis thaliana GA METHYL TRANSFERASE 1 (AtGAMT1) gene. AtGAMT1 encodes an enzyme that catalyses the methylation of active GAs to generate inactive GA methyl esters. Tomato plants overexpressing AtGAMT1 exhibited typical GA‐deficiency phenotypes and increased tolerance to drought stress. GA application to the transgenic plants restored normal growth and sensitivity to drought. The transgenic plants maintained high leaf water status under drought conditions, because of reduced whole‐plant transpiration. The reduced transpiration can be attributed to reduced stomatal conductance. GAMT1 overexpression inhibited the expansion of leaf‐epidermal cells, leading to the formation of smaller stomata with reduced stomatal pores. It is possible that under drought conditions, plants with reduced GA activity and therefore, reduced transpiration, will suffer less from leaf desiccation, thereby maintaining higher capabilities and recovery rates.
Balancing the Risk of Eye Irritation from UV‐C with Infection from Bioaerosols
Authors: Sliney David
Published: May 2013

The very aspect (phototoxicity) that makes short‐wavelength ultraviolet (UV) radiation an effective germicidal agent also is responsible for the unwanted side effects of erythema (reddening of the skin) and photokeratitis (“welder's flash” or “snow‐blindness”). Overexposure to this short‐wavelength UV radiation can produce these unwanted side effects from a very mild irritation of the skin and eyes to a rather painful case of photokeratitis. These effects are fortunately transient, as only superficial cells of the eye—the corneal epithelium—and the most superficial layer of the skin—the superficial epidermis—are significantly affected. Normal turnover of these cells soon erase the signs and symptoms of these effects. Radiant energy in the UV‐C band has very shallow penetration depths which account for the very superficial nature of any injury to the skin and eyes from excessive exposure, minimum risk of delayed effects and at the same time the strong absorption by bioaerosols. Guidelines for human exposure to UV‐C must be applied intelligently so as not to limit germicidal efficacy in upper‐room ultraviolet germicidal irradiation.
Does artificial UV use prior to spring break protect students from sunburns during spring break?
Authors: Dennis Leslie K. , Lowe John B.
Published: May 2013

Background

Dark‐skinned individuals are less likely than light‐skinned individuals to become sunburned or develop skin cancer. Some have extrapolated this relationship and surmised that developing and maintaining a tan will reduce the risk of sunburns and melanoma. In order to examine whether this strategy indeed protects against sunburns, we surveyed college students about both their tanning habits prior to spring break and their spring break activities.

Methods

Sorority and fraternity students were recruited after spring break. Analyses examined associations between potential risk factors and the development of one or more sunburns during spring break.

Results

As expected, the risk of obtaining a sunburn increased with: time spent in the sun during spring break; light complexion, as assessed by various sun‐sensitivity factors; and lack of sunscreen use. We also found that tanning using an artificial UV source during the 10 weeks prior to spring break was not associated with reduced risk of sunburns during spring‐break, but rather with a marginal increase in this risk.

Conclusions

These data provide evidence that maintaining a tan may not provide protection from sunburns. Public health messages need to address this misconception, stating clearly that a tan does not protect against or reduce the chances of developing a sunburn.
Chemical analysis and in vitro UV‐protection characteristics of clays traditionally used for sun protection in South Africa
Authors: Dlova Ncoza C. , Nevondo Funanani T. , Mwangi Elizabeth M. , Summers Beverley , Tsoka‐Gwegweni Joyce , Martincigh Bice S. , Mulholland Dulcie A.
Published: May 2013

Clays have been used in southern Africa as photoprotectants by the indigenous people. Typically, two types of clay are used: one white in colour and the other red. In this work, the two clays were identified and characterized, and their in vitro SPF values measured. The clays afford a low SPF but offer broad‐spectrum protection. No cutaneous side effects from the use of these clays are known. Further consideration should be given to the potential use of clays in sunscreen preparations.
5‐aminolevulinic acid‐based photodynamic therapy for the treatment of condylomata acuminata in Chinese patients: a meta‐analysis
Authors: Ying Zuolin , Li Xiaojie , Dang Hong
Published: May 2013

Objective

This meta‐analysis was designed to assess the efficacy of topical 5‐aminolaevulinic acid (ALA) photodynamic therapy (PDT) in Chinese patients with condylomata acuminata (CA).

Methods

Electronic literature databases (Medline, Embase, Cochrane Library, China National Knowledge Infrastructure, and Wanfang database) were searched for relevant randomized controlled trials (RCTs) published prior to October 2012. Only RCTs that compared ALA‐PDT to non‐ALA‐PDT for patients with genital condylomata were selected. The outcomes included the recurrence rate and adverse events. The risk ratios (RRs) and 95% confidence intervals (CIs) were calculated as the ALA‐PDT vs. without ALA‐PDT.

Results

Twenty RCTs composed of 1903 patients (ALA‐PDT, n = 1106; non‐ALA‐PDT, n = 797) were included in the meta‐analysis. ALA‐PDT decreased the recurrence rate within 12 week after treatment (vs. without ALA‐PDT, RR: 0.28, 95% CI: 0.22–0.35) and 24 week after treatment (vs. without ALA‐PDT, RR: 0.24, 95% CI: 0.17–0.34) in a fixed‐effect model. The common adverse events related ALA‐PDT included a mild burning and/or stinging sensation, erythema, mild edema, erosion, and hyperpigmentation.

Conclusion

Local application of ALA‐PDT reduced recurrence rate vs. without ALA‐PDT. The use of ALA‐PDT should be considered as a feasible therapy for the treatment of CA.
A Lottery Paradox for Counterfactuals Without Agglomeration
Authors: Leitgeb Hannes
Published: May 2013

We will present a new lottery‐style paradox on counterfactuals and chance. The upshot will be: combining natural assumptions on (i) the truth values of ordinary counterfactuals, (ii) the conditional chances of possible but non‐actual events, (iii) the manner in which (i) and (ii) relate to each other, and (iv) a fragment of the logic of counterfactuals leads to disaster. In contrast with the usual lottery‐style paradoxes, logical closure under conjunction—that is, in this case, the rule of Agglomeration of (consequents of) counterfactuals—will not play a role in the derivation and will not be entailed by our premises either. We will sketch four obvious but problematic ways out of the dilemma, and we will end up with a new resolution strategy that is non‐obvious but (as we hope) less problematic: contextualism about what counts as a proposition. This proposal will not just save us from the paradox, it will also save each premise in at least some context, and it will be motivated by independent considerations from measure theory and probability theory.
Probiotics in aquaculture: a current assessment
Authors: Pérez‐Sánchez Tania , Ruiz‐Zarzuela Imanol , de Blas Ignacio , Balcázar José L.
Published: May 2013

Because of health and environmental concerns, the use of chemotherapeutic agents has been restricted in many countries over recent years. This restriction has resulted in a demand for alternative strategies to improve aquaculture production and enhance disease resistance. Among these options, probiotics, live micro‐organisms that confer a health benefit to the host by providing both a nutritional benefit and protection against pathogens, represent an important option for the management of diseases and their use may replace some of the therapeutic chemicals commonly used in aquaculture. Our review explores the current state of knowledge on the impacts of probiotics on aquaculture, with particular emphasis on the criteria used for selection and evidence of their beneficial effects.
Temporomandibular disorder in a patient with pseudoxanthoma elasticum: a case report and review
Authors: Nadeau Christine , Kuperstein Arthur S. , Mupparapu Muralidhar , Stoopler Eric T.
Published: May 2013

Pseudoxanthoma elasticum (PXE) is a disorder characterized by progressive degeneration of elastic fibers and ectopic mineralization. Cutaneous manifestations are a hallmark of this disease and organs that may be affected by the disease process include cardiovascular, central nervous system, ocular and gastrointestinal systems. Oral manifestations of PXE have been previously reported as intramucosal nodules observed on various intraoral surfaces. We present a case of a 46‐year‐old female with PXE diagnosed with temporomandibular disorder (TMD). To our knowledge, this is the first report of a patient with TMD coexisting with PXE in the scientific literature.
The effect of speech therapy on acoustic speech characteristics of cleft lip and palate patients: a preliminary study
Authors: Jahanbin Arezoo , Pahlavannezhad Mohammad Reza , Savadi Maryam , Hasanzadeh Nadia
Published: May 2013

Purpose

To assess the effects of speech therapy on the acoustic characteristics of speech in a group of cleft lip and palate patients.

Materials and methods

In this experimental pilot study, eight patients with unilateral cleft lip and palate participated in the 13‐month period of speech therapy. They had some exercises in the class and at home to reduce the hypernasality of speech. Using an acoustic software named Praat, three formants (F1, F2, F3) of speech sounds /b /, /p /, /f /, /v /, /k /, and /g / were obtained pre and post speech therapy. We used paired samples t‐test to compare the acoustic variables of each consonant before and after the therapy.

Results

No significant differences were found between the pre‐ and posttherapy acoustic measures for fricative consonants /f /, /v / and stop consonants /k / and /g/. However, a statistically significant improvement in hypernasality of labial consonants /b / and /p / was observed after the speech therapy.

Conclusions

The present study underlines the role of a speech therapist in a complete cleft care team, in order to take care of the speech improvement of the patient and to motivate the parents to help the speech development of their child.
Tumour Regression Induced by Co‐administration of MIP‐3α and CpG in an Experimental Model of Colon Carcinoma
Authors: Arab S. , Mojarrad M. , Motamedi M. , Mirzaei R. , Modarressi M. H. , Hadjati J.
Published: May 2013

CCL20/macrophage inflammatory protein‐3α (MIP‐3α) represents one of the potent chemoattractive proteins for dendritic cells (DCs). Herein, we investigated whether in vivo genetic modification of tumour cells aimed at intratumoural production of MIP‐3α might lead to accumulation of DCs in tumour tissue. Mice injected with CT26, received recombinant adenovirus (Ad) vectors (AdMIP‐3α) expressing MIP‐3α protein. This was complemented by injections of CpG. Interestingly, MIP‐3α gene therapy combined with CpG injections resulted in specific cytotoxicity. This was associated with significant suppression of tumour growth rate. These findings demonstrate the potential of strategies that utilize in vivo overexpression of chemokines.
Atrial Fibrillation: Inflammation in Disguise?
Authors: Lappegård K. T. , Hovland A. , Pop G. A. M. , Mollnes T. E.
Published: May 2013

Atrial fibrillation is highly prevalent, and affected patients are at an increased risk of a number of complications, including heart failure and thrombo‐embolism. Over the past years, there has been increasing interest in the role of inflammatory processes in atrial fibrillation, from the first occurrence of the arrhythmia to dreaded complications such as strokes or peripheral emboli. As the standard drug combination which aims at rate control and anticoagulation only offers partial protection against complications, newer agents are needed to optimize treatment. In this paper, we review recent knowledge regarding the impact of inflammation on the occurrence, recurrence, perpetuation and complications of the arrhythmia, as well as the role of anti‐inflammatory therapies in the treatment for the disease.
The Role of Microparticles in the Pathogenesis of Rheumatoid Arthritis and Systemic Lupus Erythematosus
Authors: Dye J. R. , Ullal A. J. , Pisetsky D. S.
Published: May 2013

Microparticles (MPs) are small membrane‐bound vesicles with potent biological activities that can promote the pathogenesis of rheumatoid arthritis and systemic lupus erythematosus (SLE). These particles contain diverse cellular components and are shed from cells during apoptosis or activation.MPs can drive inflammation and autoimmunity by multiple mechanisms reflecting their content of bioactive molecules and ability to engage multiple receptor systems simultaneously. In the rheumatoid joint, particles can stimulate synovitis via their display of cytokines, chemokines, complement and angiogenesis factors. InSLE, particles can serve as an important source of extracellular nuclear molecules to signal ‘danger’ and form pathogenic immune complexes. Future studies will define the pathways by which particles promote pathogenesis, strategies to block their activity and their utility as biomarkers to assess disease activity and the response to therapy.
Humoral Pattern Recognition and the Complement System
Authors: Degn S. E. , Thiel S.
Published: May 2013

In the context of immunity, pattern recognition is the art of discriminating friend from foe and innocuous from noxious. The basis of discrimination is the existence of evolutionarily conserved patterns on microorganisms, which are intrinsic to these microorganisms and necessary for their function and existence. Such immutable or slowly evolving patterns are ideal handles for recognition and have been targeted by early cellular immune defence mechanisms such as Toll‐like receptors, NOD‐like receptors, RIG‐I‐like receptors, C‐type lectin receptors and by humoral defence mechanisms such as the complement system. Complement is a proteolytic cascade system comprising around 35 different soluble and membrane‐bound proteins. It constitutes a central part of the innate immune system, mediating several major innate effector functions and modulating adaptive immune responses. The complement cascade proceeds via controlled, limited proteolysis and conformational changes of constituent proteins through three activation pathways: the classical pathway, the alternative pathway and the lectin pathway, which converge in common effector functions. Here, we review the nature of the pattern recognition molecules involved in complement activation, as well as their close relatives with no or unknown capacity for activating complement. We proceed to examine the composition of the pattern recognition complexes involved in complement activation, focusing on those of the lectin pathway, and arrive at a new model for their mechanism of operation, supported by recently emerging evidence.
The schema provokes a disparity of false recollection between actions and objects in an everyday scene
Authors: Yamada Ryoma , Itsukushima Yukio
Published: May 2013

We explored the effect of the schema on recognition memories and subjective experiences for actions and objects in an everyday scene. At first, participants watched slides of a man cooking in a kitchen. The man performed schema‐consistent actions, and schema‐consistent objects were left. After watching the slides, participants completed a recognition test, a remember/know test, and a Perception/Thought/Emotion/Context questionnaire. We confirmed three main results. First, participants made more false recognitions for schema‐consistent distracters than for schema‐inconsistent distracters with more “remember” judgments accompanied by perceptual, thought, and contextual details, and with more “know” judgments. Second, participants made more false recognitions for schema‐consistent object distracters than for schema‐consistent action distracters. Third, participants more frequently recognized schema‐consistent action targets than schema‐consistent object targets with more “remember” judgments. Both action memory and object memory were reconstructed under the schema, provoking false recognitions for schema‐consistent distracters. However, the memories of schema‐consistent action targets were so recollective that they could prevent false recognitions for schema‐consistent action distracters.
Image‐based Continuous Displacement Measurements Using an Improved Spectral Approach
Authors: Mortazavi F. , Lévesque M. , Villemure I.
Published: May 2013

Digital Image Correlation algorithms capable of determining continuous displacement fields are receiving growing attention in the field of mechanical properties identification. In this paper, we develop an Improved Spectral Approach (ISA) to reconstruct continuous displacements based on their Fourier decomposition. This approach leads to a time and memory‐efficient algorithm, thanks to the fast Fourier transform. Moreover, the Fourier‐based decomposition enables accurate heterogeneous measurements. Improvements consist in increasing the accuracy and convergence rate as well as dealing with non‐periodic displacements and images. Furthermore, a theoretical framework is presented to quantify the noise sensitivity of the ISA from which useful information is retrieved. The approach is evaluated using synthetic images deformed by heterogeneous displacement fields. Comparisons show that the introduced modifications lead to lower uncertainties by one order of magnitude in the case of non‐periodic images and displacement field studied. Moreover, first‐order (SO1) and second‐order (SO2) subset‐based Digital Image Correlation algorithms are compared with the ISA. The comparisons herein reveal that the uncertainties of the ISA are 6–9 times smaller than those of the SO1 due to insufficiency of the first‐order shape function for the estimation of heterogeneous displacements, while being slightly smaller than those of the SO2. Moreover, as the image smoothness decreases, the uncertainties of the SO2 deviate from those of the ISA and the exact displacements. The presented approach shows great potentials for challenging applications such as strain measurements at microstructural levels.
A facies‐based depositional model for ancient and modern, tectonically–confined tidal straits
Authors: Longhitano Sergio G.
Published: May 2013

Modern and ancient tidal straits are the least well understood of all tide‐dominated depositional systems. To provide an increased understanding of these systems, a facies‐based depositional model is assessed by comparing multibeam surveys of three present‐day tidally dominated seaways with a number of superbly exposed Neogene‐to‐Quaternary strait‐fill successions of Calabria (south Italy).

The model points out the existence of four depositional zones, laterally adjacent from the narrowest strait centre to its terminations, distributed along symmetrical or asymmetrical seaways.

These zones, whose signature is recorded in four facies associations in the Calabrian tidal straits, are as follows: (i) the strait‐centre zone, associated with the tidal current maxima and where sediments are scarce or absent; (ii) the dune‐bedded zone, where sediments form dune complexes due to tidal flow expansion; (iii) the strait‐end zone, where currents decelerate accumulating thinly bedded, fine‐grained deposits; and (iv) the strait‐margin zone, where sediment massflows descend tectonically active, steep margins towards the strait axis.

In ancient, tectonically confined, narrow seaways, these facies generate a distinctive deepening‐upward vertical succession, where tidal currents are the dominant process in the sediment distribution.
Ensuring that blood transfusion sets administer an effective dose of functional blood components
Authors: Bashir S. , Nightingale M. J. , Cardigan R.
Published: May 2013

SUMMARY

Background

Proposed changes to ISO 1135‐4 will require that blood transfusion administration sets are demonstrated by the manufacturers to be suitable for the range of cellular and plasma blood components for which they are designated.

Aims

To design a test protocol to asses the depletion of the blood components by transfusion sets and damage and activation of blood components during their passage through the set.

Methods

Transfusion giving sets (CareFusion Ref no. 60895 180311 and Fresenius Ref no. 2900032) were assessed by comparing samples of the blood component taken prior to and after passage through the transfusion set in strict accordance with the manufacturer's instructions. As well as depletion of red cells, platelets and FVIIIc, the following markers of damage/activation were assessed: red cells—supernatant haemolysis and potassium; FFP—prothrombin fragments 1 and 2 and fibrinopeptide A and platelets—pH, CD62P, CD63 and sP‐selectin.

Results

The CareFusion and the Fresenius transfusion sets gave less than 5% depletion of blood components and caused negligible and clinically insignificant effects on red cells, platelet concentrates and FFP.

Conclusion

A practical test protocol has been established to assess the depletion, damage to and activation of the key constituents of commonly requested blood components. This protocol would provide a valuable addition to ISO 1135‐4 in assuring the suitability of transfusion sets.
Evaluation of azithromycin in systemic and toothpaste forms for the treatment of ciclosporin‐associated gingival overgrowth in dogs
Authors: Rosenberg Andrew , Rosenkrantz Wayne , Griffin Craig , Angus John , Keys Deborah
Published: May 2013

Background

Gingival overgrowth is an adverse effect of ciclosporin therapy. Azithromycin (AZI) in capsule and toothpaste form is an effective treatment for ciclosporin‐associated gingival overgrowth (CsAGO) in humans.

Hypothesis/Objectives

To evaluate AZI in a systemic and a toothpaste form for the treatment of CsAGO in dogs. The secondary objective was to determine which treatment is more effective.

Animals

Thirty‐six client‐owned dogs with CsAGO.

Methods

Dogs were randomly assigned to the following four groups: AZI capsule; AZI toothpaste; placebo capsule; and placebo toothpaste. Treatments were for 4 weeks, and measurements of gingival sulcus depth, tooth length and subjective global scores were taken at weeks 0, 2, 4 and 8. The AZI dose was 10 mg/kg daily, and brushing (8.5% AZI) was once daily.

Results

There was a significant decrease in gingival sulcus depth for the AZI capsule group at week 8 and for the AZI toothpaste group at weeks 2, 4 and 8. The mean decrease in gingival sulcus depth was significantly greater in active versus placebo groups (P = 0.0356). The tooth length and subjective global scores were not significantly different for any groups. Gastrointestinal adverse events occurred in all groups, but more frequently in the AZI capsule group.

Conclusions and clinical importance

Azithromycin improved CsAGO in only one measured parameter, gingival sulcus depth. Only one dog in the AZI capsule group had complete resolution of CsAGO. Further studies are warranted. Azithromycin capsules were associated with the most gastrointestinal adverse effects.
Prioritization of subwatersheds based on flooding conditions using hydrological model, multivariate analysis and remote sensing technique
Authors: Darabi Hamid , Shahedi Kaka , Solaimani Karim , Miryaghoubzadeh Mirhasan
Published: May 2013

Prioritization of watersheds has gained more importance in natural resources management, particularly in the context of watershed management. Flooding potential is one of the main indices used to prioritize watersheds. The objective of this study is to investigate the Pol‐Doab Shazand Watershed flooding conditions as a result of land use change and prioritization of its subwatersheds using rainfall – runoff data. For this purpose, after computation of design flow with different return periods, factor analysis technique was applied to determine the best flow with proper return period towards evaluation and prioritization of subwatersheds. The results showed that the design flow with 25‐year return period (Q25) is suitable. The results indicate that subwatershed 22 is the highest priority because of large changes in peak flow, and subwatershed 2 given the lowest priority since changes in peak flow is the lowest.
Leptospira interrogans at the Human–Wildlife Interface in Northern Botswana: A Newly Identified Public Health Threat
Authors: Jobbins S. E. , Sanderson C. E. , Alexander K. A.
Published: May 2013

Leptospirosis is the most widespread zoonosis in the world. In northern Botswana, humans live in close proximity to a diversity of wildlife and peridomestic rodents and may be exposed to a variety of zoonotic pathogens. Little is known regarding the occurrence and epidemiology of L. interrogans in Africa despite the recognized global importance of this zoonotic disease and the threat it poses to public health. In Botswana, banded mongooses (Mungos mungo) live in close proximity to humans across protected and unprotected landscapes and may be a useful sentinel species for assessing the occurrence of zoonotic organisms, such as L. interrogans. We utilized PCR to screen banded mongoose kidneys for leptospiral DNA and identified 41.5% prevalence of renal carriage of L. interrogans (exact binomial 95% CI 27.7–56.7%, n = 41). Renal carriage was also detected in one Selous' mongoose (Paracynictis selousi). This is the first published confirmation of carriage of L. interrogans in either species. This is also the first report of L. interrogans occurrence in northern Botswana and the only report of this organism in a wildlife host in the country. Pathogenic Leptospira are usually transmitted indirectly to humans through soil or water contaminated with infected urine. Other avenues, such as direct contact between humans and wildlife, as well as consumption of mongooses and other wildlife as bushmeat, may pose additional exposure risk and must be considered in public health management of this newly identified zoonotic disease threat. There is a critical need to characterize host species involvement and pathogen transmission dynamics, including human–wildlife interactions that may increase human exposure potential and infection risk. We recommend that public health strategy be modified to include sensitization of medical practitioners to the presence of L. interrogans in the region, the potential for human infection, and implementation of clinical screening. This study illustrates the need for increased focus on neglected zoonotic diseases as they present an important threat to public health.
Heterogeneous responses of nucleus incertus neurons to corticotrophin‐releasing factor and coherent activity with hippocampal theta rhythm in the rat
Authors: Ma Sherie , Blasiak Anna , Olucha‐Bordonau Francisco E. , Verberne Anthony J. M. , Gundlach Andrew L.
Published: May 2013

Key points

The nucleus incertus (NI) is a stress and arousal responsive, hindbrain region involved in ascending control of septohippocampal theta rhythm.

NI neurons express high levels of the neuropeptide relaxin‐3 and corticotrophin‐releasing factor (CRF) receptor‐1 (CRF‐R1).

We report the first in‐depth characterization of NI neurons, using in vivo and in vitro electrophysiological techniques, which reveal a population of relaxin‐3‐containing NI neurons activated by CRF via postsynaptic CRF‐R1 and a non‐relaxin‐3 neuron population inhibited or unaffected by CRF.

Relaxin‐3 NI neurons exhibit strong phase‐locked firing with the ascending phase of hippocampal theta oscillations.

These findings suggest the NI is a heterogeneous neuronal population and key site of CRF action with the capacity to modulate cognition in response to stress.

Abstract  The nucleus incertus (NI) of the rat hindbrain is a putative node in the ascending control of the septohippocampal system and hippocampal theta rhythm and is stress and arousal responsive. NI contains GABA neurons that express multiple neuropeptides, including relaxin‐3 (RLN3) and neuropeptide receptors, including corticotrophin‐releasing factor receptor‐1 (CRF‐R1), but the precise anatomical and physiological characteristics of NI neurons are unclear. Therefore, we examined the firing properties of NI neurons and their responses to CRF, the correlation of these responses with occurrence of relaxin‐3, and NI neuron morphology in the rat. Most NI neurons excited by intracerebroventricular CRF infusion were RLN3‐positive (9 of 10), whereas all inhibited cells were RLN3‐negative (8 of 8). The spontaneous firing of RLN3 (n= 6) but not non‐RLN3 neurons (n= 6) was strongly modulated and phase‐locked with the initial ascending phase of hippocampal theta oscillations. In brain slices, the majority of recorded NI neurons (15 of 19) displayed excitatory responses to CRF, which uniformly increased action potential frequency and membrane potential depolarization in the presence of tetrodotoxin, indicating a direct, postsynaptic action of CRF on NI neurons. This excitation was associated with reduction in the slow component of afterhyperpolarization and a strong depolarization. Quantitative analysis in naïve rats of validated CRF‐R1, RLN3 and neuronal nuclear antigen (NeuN) immunoreactivity revealed 52% of NI neurons as CRF‐R1 positive, of which 53% were RLN3 positive, while 48% of NI neurons lacked CRF‐R1 and RLN3. All RLN3 neurons expressed CRF‐R1. CRF neurons that projected to the NI were identified in lateral preoptic hypothalamus, but not in paraventricular hypothalamus, bed nucleus of stria terminalis or central amygdala. Our findings suggest NI is an important site for CRF modulation of hippocampal theta rhythm via effects on GABA/RLN3 transmission.
Oxygen sensitivity of mitochondrial function in rat arterial chemoreceptor cells
Authors: Buckler Keith J. , Turner Philip J.
Published: May 2013

Key points

Arterial chemoreceptors measure blood oxygen and are involved in the control of both breathing and the cardiovascular system.

Oxygen is mostly used by cells in their mitochondria to generate energy.

In this study we have investigated the effects of oxygen starvation (hypoxia) on the mitochondria of specialised oxygen sensing cells from arterial chemoreceptors.

Our data confirm that the mitochondria of these oxygen sensing cells are unusually sensitive to modest hypoxia. This effect seems to stem from a reduced affinity of the oxygen utilising enzyme cytochrome oxidase for oxygen.

These results are consistent with a functional adaptation of the mitochondria of oxygen sensing cells that may enable them to play a direct role in the oxygen sensing process itself.

Abstract  The mechanism of oxygen sensing in arterial chemoreceptors is unknown but has often been linked to mitochondrial function. A common criticism of this hypothesis is that mitochondrial function is insensitive to physiological levels of hypoxia. Here we investigate the effects of hypoxia (down to 0.5% O2) on mitochondrial function in neonatal rat type‐1 cells. The oxygen sensitivity of mitochondrial [NADH] was assessed by monitoring autofluorescence and increased in hypoxia with a P50 of 15 mm Hg (1 mm Hg = 133.3 Pa) in normal Tyrode or 46 mm Hg in Ca2+‐free Tyrode. Hypoxia also depolarised mitochondrial membrane potential (ψm, measured using rhodamine 123) with a P50 of 3.1, 3.3 and 2.8 mm Hg in normal Tyrode, Ca2+‐free Tyrode and Tyrode containing the Ca2+ channel antagonist Ni2+, respectively. In the presence of oligomycin and low carbonyl cyanide 4‐(trifluoromethoxy) phenylhydrazone (FCCP; 75 nm) ψm is maintained by electron transport working against an artificial proton leak. Under these conditions hypoxia depolarised ψm/inhibited electron transport with a P50 of 5.4 mm Hg. The effects of hypoxia upon cytochrome oxidase activity were investigated using rotenone, myxothiazol, antimycin A, oligomycin, ascorbate and the electron donor tetramethyl‐p‐phenylenediamine. Under these conditions ψm is maintained by complex IV activity alone. Hypoxia inhibited cytochrome oxidase activity (depolarised ψm) with a P50 of 2.6 mm Hg. In contrast hypoxia had little or no effect upon NADH (P50= 0.3 mm Hg), electron transport or cytochrome oxidase activity in sympathetic neurons. In summary, type‐1 cell mitochondria display extraordinary oxygen sensitivity commensurate with a role in oxygen sensing. The reasons for this highly unusual behaviour are as yet unexplained.
Complex Orthogonal Decomposition Applied to Nematode Posturing
Authors: Feeny B. F. , Sternberg P. W. , Cronin C. J. , Coppola C. A.
Published: May 2013

The complex orthogonal decomposition (COD), a process of extracting complex modes from complex ensemble data, is summarized, as is the use of complex modal coordinates. A brief assessment is made on how small levels of noise affect the decomposition. The decomposition is applied to the posturing of Caenorhabditis elegans, an intensively studied nematode. The decomposition indicates that the worm has a multimodal posturing behavior, involving a dominant forward locomotion mode, a secondary, steering mode, and likely a mode for reverse motion. The locomotion mode is closer to a pure traveling waveform than the steering mode. The characteristic wavelength of the primary mode is estimated in the complex plane. The frequency is obtained from the complex modal coordinate's complex whirl rate of the complex modal coordinate, and from its fast Fourier transform. Short-time decompositions indicate the variation of the wavelength and frequency through the time record.
A Methodology for Protective Vibration Monitoring of Hydropower Units Based on the Mechanical Properties
Authors: Nässelqvist Mattias , Gustavsson Rolf , Aidanpää Jan-Olov
Published: May 2013

It is important to monitor the radial loads in hydropower units in order to protect the machine from harmful radial loads. Existing recommendations in the standards regarding the radial movements of the shaft and bearing housing in hydropower units, ISO-7919-5 (International Organization for Standardization, 2005, “ISO 7919-5: Mechanical Vibration—Evaluation of Machine Vibration by Measurements on Rotating Shafts—Part 5: Machine Sets in Hydraulic Power Generating and Pumping Plants,” Geneva, Switzerland) and ISO-10816-5 (International Organization for Standardization, 2000, “ISO 10816-5: Mechanical Vibration—Evaluation of Machine Vibration by Measurements on Non-Rotating Parts—Part 5: Machine Sets in Hydraulic Power Generating and Pumping Plants,” Geneva, Switzerland), have alarm levels based on statistical data and do not consider the mechanical properties of the machine. The synchronous speed of the unit determines the maximum recommended shaft displacement and housing acceleration, according to these standards. This paper presents a methodology for the alarm and trip levels based on the design criteria of the hydropower unit and the measured radial loads in the machine during operation. When a hydropower unit is designed, one of its design criteria is to withstand certain loads spectra without the occurrence of fatigue in the mechanical components. These calculated limits for fatigue are used to set limits for the maximum radial loads allowed in the machine before it shuts down in order to protect itself from damage due to high radial loads. Radial loads in hydropower units are caused by unbalance, shape deviations, dynamic flow properties in the turbine, etc. Standards exist for balancing and manufacturers (and power plant owners) have recommendations for maximum allowed shape deviations in generators. These standards and recommendations determine which loads, at a maximum, should be allowed before an alarm is sent that the machine needs maintenance. The radial bearing load can be determined using load cells, bearing properties multiplied by shaft displacement, or bearing bracket stiffness multiplied by housing compression or movement. Different load measurement methods should be used depending on the design of the machine and accuracy demands in the load measurement. The methodology presented in the paper is applied to a 40 MW hydropower unit; suggestions are presented for the alarm and trip levels for the machine based on the mechanical properties and radial loads.
Adaptive Observer-Based Integrated Fault Diagnosis and Fault-Tolerant Control Systems Against Actuator Faults and Saturation
Authors: Fan Jinhua , Zhang Youmin , Zheng Zhiqiang
Published: May 2013

A challenging problem on observer-based, integrated fault diagnosis and fault-tolerant control for linear systems subject to actuator faults and control input constraints is studied in this paper. An adaptive observer approach is used for the joint state-fault magnitude estimation, and a feedback controller is designed to stabilize the closed-loop system without violating the actuator limits in the presence of actuator faults. Matrix inequality conditions are provided for computation of design parameters of the observer and the feedback controller, and the admissible initial conditions and estimation errors are bounded by invariant ellipsoidal sets. The design results are closely related to the fault magnitude and variation rate, and a necessary condition on the admissible fault magnitudes dependent on the control limits is directly obtained from the design process. The proposed design framework allows a direct application of the pole placement method to obtain stabilization results. To improve the system performance, a nonlinear programming-based optimization algorithm is proposed to compute an optimized feedback gain, whereas the one obtained by pole placement can be taken as an initial feasible solution for nonlinear optimization. Numerical studies with two flight control systems demonstrate the effectiveness of proposed design techniques.