Effects of mild hypoxia in aviation on mood and complex cognition

Thirty six volunteer air force personnel were sequentially exposed in a randomized balanced order in a hypobaric chamber to 30 min of baseline (sea level) and mild hypoxia induced by a specified altitude (sea level, 8000 ft and 12,000 ft), followed immediately by breathing 100% oxygen from an oro-nasal mask. Mood and complex cognition were assessed. Analysis of variance indicated that mood (fatigue and vigour) remained the same at 8000 ft but fatigue was increased (p = 0.001) and vigour reduced (p = 0.035) at 12,000 ft and was restored by supplementary oxygen. Complex cognition was not significantly altered by the test conditions. The results of this study do not support prior evidence that mild hypoxia equivalent to either 8000 or 12,000 ft, impairs complex cognition, but suggests that some aspects of mood may be affected at 12,000 ft and can be restored by breathing 100% oxygen.

Quantitative nanoscale electrostatics of viruses

Electrostatics is one of the fundamental driving forces of the interaction between biomolecules in solution. In particular, the recognition events between viruses and host cells are dominated by both specific and non-specific interactions and the electric charge of viral particles determines the electrostatic force component of the latter. Here we probe the charge of individual viruses in liquid milieu by measuring the electrostatic force between a viral particle and the Atomic Force Microscope tip. The force spectroscopy data of co-adsorbed ϕ29 bacteriophage proheads and mature virions, adenovirus and minute virus of mice capsids is utilized for obtaining the corresponding density of charge for each virus. The systematic differences of the density of charge between the viral particles are consistent with the theoretical predictions obtained from X-ray structural data. Our results show that the density of charge is a distinguishing characteristic of each virus, depending crucially on the nature of the viral capsid and the presence/absence of the genetic material.

Epiphyas postvittana (Lepidoptera: Tortricidae)-Botrytis cinerea (Helotiales: Sclerotiniaceae)-Vitis vinifera (Vitales: Vitaceae) Interaction: The Role of B. cinerea on the Development of E. postvittana in Synthetic Nutritional Media

Epiphyas postvittana (Walker) (light-brown apple moth) is a polyphagous herbivore of economic significance, which also feeds on Vitis vinifera L. The E. postvittana-V. vinifera interacting system also involves the participation of the fungus Botrytis cinerea Persoon ex Fries. We have been exploring the relationship among E. postvittana-V. vinifera-B. cinerea over the past two years. In this article, we report the preference and performance of the larvae of E. postvittana raised solely on a synthetic diet incorporated with the mycelial material of B. cinerea (Diet B). To characterize the effect of fungus on the development of E. postvittana, another synthetic diet was prepared that included the lyophilized leaf material of V. vinifera (Diet C). When raised on Diets B and C, a decrease in the duration of larval development and an increase in the survival and fecundity rate of E. postvittana occurred. Diet B influenced the pupal mass, but a significant increase occurred when the larvae were fed on Diet C. The larval emergence rate was the greatest in E. postvittana raised on Diet B, followed by those on Diet C. The F(2) generation of the larvae reared on Diet B showed similar effects as F(1) on the life-history performance of the larvae. Diet B enhanced the life-history performance of E. postvittana, although the larvae of E. postvittana showed little preference to Diet B. The greater fertility rate of E. postvittana reared on Diet B suggests the importance of sterols as shown in Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) and in a few Myrmicinae (Hymenoptera: Formicidae), which serve as precursors to different ecdysteroids that regulate many critical processes through embryonic development.

Quinoline benzimidazole-conjugate for the highly selective detection of Zn(ii) by dual colorimetric and fluorescent turn-on responses

A quinoline benzimidazole-conjugate (QBC) has been synthesized for the highly selective detection of Zn(ii) both by colorimetry and fluorimetry.

Association of chronic periodontitis and psoriasis: periodontal status with severity of psoriasis

OBJECTIVES

The chronic periodontitis (CP) and psoriasis share common risk factors and co-morbidities. This study was designed to explore how frequently CP is associated with patients with psoriasis compared to systemic healthy subjects.

MATERIALS AND METHODS

The periodontal clinical parameters probing depth (PD), periodontal attachment level (PAL), and presence or absence of radiographic bone loss (J Periodontol, 78, 2007, 1387) were recorded in 33 psoriasis subjects and 35 healthy subjects. The severity of psoriasis was assessed and recorded by Psoriasis Area and Severity Index as described earlier by Cohen et al (J Dermatolog Treat, 16, 2005, 308). The other oral health characteristics were also recorded.

RESULTS

Probing depth and PAL showed significant higher values in psoriasis group compared with healthy group. It was also found that periodontal status was associated with severity of psoriasis.

CONCLUSIONS

The results showed a link between CP and psoriasis. This suggests the need for a multidisciplinary approach to manage psoriasis patients with chronic periodontitis, especially in relation to current and future treatment.

Salivary proteins of plant-feeding hemipteroids - implication in phytophagy

Many hemipteroids are major pests and vectors of microbial pathogens, infecting crops. Saliva of the hemipteroids is critical in enabling them to be voracious feeders on plants, including the economically important ones. A plethora of hemipteroid salivary enzymes is known to inflict stress in plants, either by degrading the plant tissue or by affecting their normal metabolism. Hemipteroids utilize one of the following three strategies of feeding behaviour: salivary sheath feeding, osmotic-pump feeding and cell-rupture feeding. The last strategy also includes several different tactics such as lacerate-and-flush, lacerate-and-sip and macerate-and-flush. Understanding hemipteroid feeding mechanisms is critical, since feeding behaviour directs salivary composition. Saliva of the Heteroptera that are specialized as fruit and seed feeders, includes cell-degrading enzymes, auchenorrhynchan salivary composition also predominantly consists of cell-degrading enzymes such as amylase and protease, whereas that of the Sternorhyncha includes a variety of allelochemical-detoxifying enzymes. Little is known about the salivary composition of the Thysanoptera. Cell-degrading proteins such as amylase, pectinase, cellulase and pectinesterase enable stylet entry into the plant tissue. In contrast, enzymes such as glutathione peroxidase, laccase and trehalase detoxify plant chemicals, enabling the circumvention of plant-defence mechanisms. Salivary enzymes such as M1-zinc metalloprotease and CLIP-domain serine protease as in Acyrthosiphon pisum (Aphididae), and non-enzymatic proteins such as apolipophorin, ficolin-3-like protein and 'lava-lamp' protein as in Diuraphis noxia (Aphididae) have the capacity to alter host-plant-defence mechanisms. A majority of the hemipteroids feed on phloem, hence Ca++-binding proteins such as C002 protein, calreticulin-like isoform 1 and calmodulin (critical for preventing sieve-plate occlusion) are increasingly being recognized in hemipteroid-plant interactions. Determination of a staggering variety of proteins shows the complexity of hemipteroid saliva: effector proteins localized in hemipteran saliva suggest a similarity to the physiology of pathogen-plant interactions.

Four component domino reaction for the synthesis of highly functionalized dimeric tetracyclic dilactam fluorophores: H-bond aided self-assembly

A series of new dimeric tetracyclic dilactam fluorophores (DTDF) consisting of diazabicyclooctane-dione (DBOD) fused to tetrahydronaphthalene (THP) was designed and synthesized from a simple precursor.

Pyrene pyridine-conjugate as Ag selective fluorescent chemosensor

A new pyrene pyridine conjugate (PPC) has been developed as a selective fluorescent sensor for Ag⁺ion.

Influence of ureteric anastomosis technique on urological complications after kidney transplantation

The best technique for anastomosis of the donor ureter remains unresolved and an individual surgeon's preferred technique is likely to be based on training background. This retrospective analysis compares three ureteroneocystostomy techniques in 204 consecutive transplants with an overall ureteric complication rate of 7.3%. Ureteric complications after kidney transplantation present early, are more common when using deceased donor kidneys, and, require complex reconstructive surgery to resolve. Three significant and related findings have been demonstrated with a common theme related to the length of the transplanted ureter, and not, the debate over extravesical versus intravesical techniques.

Extension MRI is clinically useful in cervical myelopathy

INTRODUCTION

Cervical spine MRI with the neck in extension has been well described over the last 10 years, but its clinical value remains unknown.

METHODS

We performed extension imaging in 60 patients in whom the initial neutral study showed borderline cord compression. Images were assessed using a previously validated grading system for cord compression. Multiple linear and area measurements were also obtained. Images were scored blindly and randomly. Inter- and intra-rater variability were determined in a subset of 20 cases. Independent clinical assessment utilised the Ranwat criteria.

RESULTS

For most parameters inter/intra-observer variance of kappa/ICC > 0.6 was highly satisfactory. Standard MR was poor at discriminating between patients with and without myelopathy (ROC analysis, area under the curve (AUC), 0.52). This was considerably improved with extension imaging (AUC, 0.60), or by using the change in compression score between neutral and extension studies. Most measurements were not helpful; however, the ratio of cord area/CSF area at the level of maximum compression on extended images was the best discriminator (AUC, 0.71), as well as the presence of T2 change in cord substance (AUC, 0.68).

CONCLUSION

This is the first study to demonstrate added clinical value utilising extension MRI. In this cohort of difficult patients, when there was no T2 signal change in the cord, the presence of clinical myelopathy could only be predicted by utilising the data from extension imaging.

Regulatory issues relating to herbal products-part 3: quality and its determination

ABSTRACT The concept of quality in the manufacture of herbal products is directed toward ensuring that the required standard of product is attained through processes that involve good manufacturing practice and quality control. This article reviews the need for quality assurance of herbal products, approaches taken by regulatory authorities in Europe to address this issue, and analytical methods applicable to the evaluation of herbal products. The natural ingredients that are used to prepare herbal products give rise to problems that are not encountered with conventional medicinal products. Quality standards are applied to both starting materials and finished products. Pharmacopoeial monographs, even when not forming part of official compendia, lay down criteria for analytical testing, including materials and methods, test limits, and acceptance ranges for results. Analytical tests are employed to establish the identity of the plant material or of the active principles, the content of active principles or characteristic marker compounds by assay, and the purity of the product by exclusion of specific adulterants or contaminants. Advances in instrumentation and test methods provide the analyst with powerful tools to determine the level of quality. Nevertheless, there still exist limitations to testing because of the complex and variable nature of the herbal ingredients. The standards and requirements for quality of herbal products as applied in the European Union are also intended to provide further assurances on the efficacy and safety of products.

Regulatory issues relating to herbal products-part 1: legislation in the European union, north america, and australia

ABSTRACT The increased public awareness about herbal products has led to a growth of the botanicals market and attracted the interest of the pharmaceutical industry. The laws that regulate the sale of manufactured herbal products differ between regions and countries of the Western world. The European Union favors the classification of the remedies as medicinal products. However, differences in the interpretation of European law by the Member States have meant that herbal products have been assigned to various sale categories across the European market. The European Agency for the Evaluation of Medicinal Products is working to introduce changes to achieve harmonization within the market. Canada and Australia have embarked on similar reforms to improve product regulation without imposing undue restrictions on marketing. In these countries, herbal products have been assigned a status that respects their therapeutic role. Changes introduced in the United States of America in 1994 led to a deregulation of the market with herbal products being classified as dietary supplements and excluded from the stricter regulatory requirements applicable to drugs and foods. However, a United States Presidential Commission has advised that a study is needed regarding an alternative system for botanical products that are not used solely as dietary supplements but that cannot meet the requirements applicable for conventional over-the-counter drugs.

Endophytic fungus-vascular plant-insect interactions

Insect association with fungi has a long history. Theories dealing with the evolution of insect herbivory indicate that insects used microbes including fungi as their principal food materials before flowering plants evolved. Subtlety and the level of intricacy in the interactions between insects and fungi indicate symbiosis as the predominant ecological pattern. The nature of the symbiotic interaction that occurs between two organisms (the insect and the fungus), may be either mutualistic or parasitic, or between these two extremes. However, the triangular relationship involving three organisms, viz., an insect, a fungus, and a vascular plant is a relationship that is more complicated than what can be described as either mutualism or parasitism, and may represent facets of both. Recent research has revealed such a complex relationship in the vertically transmitted type-I endophytes living within agriculturally important grasses and the pestiferous insects that attack them. The intricacy of the association depends on the endophytic fungus-grass association and the insect present. Secondary compounds produced in the endophytic fungus-grass association can provide grasses with resistance to herbivores resulting in mutualistic relationship between the fungus and the plant that has negative consequences for herbivorous insects. The horizontally transmitted nongrass type-II endophytes are far less well studied and as such their ecological roles are not fully understood. This forum article explores the intricacy of dependence in such complex triangular relationships drawing from well-established examples from the fungi that live as endophytes in vascular plants and how they impact on the biology and evolution of free-living as well as concealed (e.g., gall-inducing, gall-inhabiting) insects. Recent developments with the inoculation of strains of type-I fungal endophytes into grasses and their commercialization are discussed, along with the possible roles the endophytic fungi play in the galls induced by the Cecidomyiidae (Diptera).

High-speed atomic force microscopy in slow motion--understanding cantilever behaviour at high scan velocities

Using scanning laser Doppler vibrometer we have identified sources of noise in contact mode high-speed atomic force microscope images and the cantilever dynamics that cause them. By analysing reconstructed animations of the entire cantilever passing over various surfaces, we identified higher eigenmode oscillations along the cantilever as the cause of the image artefacts. We demonstrate that these can be removed by monitoring the displacement rather than deflection of the tip of the cantilever. We compare deflection and displacement detection methods whilst imaging a calibration grid at high speed and show the significant advantage of imaging using displacement.

Mapping nanomechanical properties of live cells using multi-harmonic atomic force microscopy

The nanomechanical properties of living cells, such as their surface elastic response and adhesion, have important roles in cellular processes such as morphogenesis, mechano-transduction, focal adhesion, motility, metastasis and drug delivery. Techniques based on quasi-static atomic force microscopy techniques can map these properties, but they lack the spatial and temporal resolution that is needed to observe many of the relevant details. Here, we present a dynamic atomic force microscopy method to map quantitatively the nanomechanical properties of live cells with a throughput (measured in pixels/minute) that is ∼10-1,000 times higher than that achieved with quasi-static atomic force microscopy techniques. The local properties of a cell are derived from the 0th, 1st and 2nd harmonic components of the Fourier spectrum of the AFM cantilevers interacting with the cell surface. Local stiffness, stiffness gradient and the viscoelastic dissipation of live Escherichia coli bacteria, rat fibroblasts and human red blood cells were all mapped in buffer solutions. Our method is compatible with commercial atomic force microscopes and could be used to analyse mechanical changes in tumours, cells and biofilm formation with sub-10 nm detail.

Sources and implications of resonant mode splitting in silicon nanowire devices

This work investigates the effects of asymmetric cross-sectional geometry on the resonant response of silicon nanowires. The work demonstrates that dimensional variances of less than 2% qualitatively alter a nanosystem's near-resonant response, yielding a non-Lorentzian frequency response structure, which is a direct consequence of resonant mode splitting. Experimental results show that this effect is independent of device boundary conditions, and can be easily modeled using continuous beam theory. Proper understanding of this phenomenon is believed to be essential in the characterization of the dynamic response of resonant nanowire systems, and thus the predictive design of such devices.

Mass and stiffness calibration of nanowires using thermally driven vibration

Cantilevered or suspended nanowires show promise for force or mass sensing applications due to their small mass, high force sensitivity and high frequency bandwidth. To use these as quantitative sensors, their bending stiffness or mass must be calibrated experimentally, often using thermally driven vibration. However, this can be difficult because nanowires are slightly asymmetric, which results in two spatially orthogonal bending eigenmodes with closely spaced frequencies. This asymmetry presents problems for traditional stiffness calibration methods, which equate the measured thermal vibration spectrum near a resonance to that of a single eigenmode. Moreover, the principal axes may be arbitrarily rotated with respect to the measurement direction. In this work, the authors propose a method for calibrating the bending stiffness and mass of such nanowires' eigenmodes using a single measurement taken at an arbitrary orientation with respect to the principal axes.

Dietary intakes of urban, high body mass index, African American children: family and child dietary attributes predict child intakes

OBJECTIVE

To identify family and child nutrition and dietary attributes related to children's dietary intakes.

DESIGN

African American children (ages 8-11 years, n = 156), body mass index > 85th percentile, from urban, low-income neighborhoods. Baseline, cross-sectional data collected as part of an ongoing diabetes prevention intervention. Dietary intakes were collected by 3-day food diary to assess total energy, percent fat, discretionary fat, added sugar, whole grains, vegetables, fruit, meat, and dairy. Questionnaires on nutrition and dietary attributes administered to children and parents were used to develop 5 diet-related indices: child knowledge, child preferences, child snack habits, child beverage habits, and family food habits.

RESULTS

A higher child nutrition knowledge score was significantly related to a lower starchy vegetable intake. Higher scores on the child snack habits index were significantly related to higher intakes of fruit, total fruits and vegetables, total fruits and nonstarchy vegetables, and to lower intakes of added sugars. A higher score on the family food habits index was significantly related to lower intakes of total energy and discretionary fat.

CONCLUSIONS AND IMPLICATIONS

Targeting both child and family food and nutrition attributes may be used to promote more healthful eating among urban, low-income, overweight African American children.