bluuebunny/crossref_metadata_2025 huggingface dataset:
Calcium signalling indicates bilateral power balancing in theDrosophilaflight muscle during manoeuvring flight
Authors: Lehmann Fritz-Olaf , Skandalis Dimitri A. , Berthé Ruben
Published: March 2013

Manoeuvring flight in animals requires precise adjustments of mechanical power output produced by the flight musculature. In many insects such as fruit flies, power generation is most likely varied by altering stretch-activated tension, that is set by sarcoplasmic calcium levels. The muscles reside in a thoracic shell that simultaneously drives both wings during wing flapping. Using a genetically expressed muscle calcium indicator, we here demonstratein vivothe ability of this animal to bilaterally adjust its calcium activation to the mechanical power output required to sustain aerodynamic costs during flight. Motoneuron-specific comparisons of calcium activation during lift modulation and yaw turning behaviour suggest slightly higher calcium activation for dorso-longitudinal than for dorsoventral muscle fibres, which corroborates the elevated need for muscle mechanical power during the wings’ downstroke. During turning flight, calcium activation explains only up to 54 per cent of the required changes in mechanical power, suggesting substantial power transmission between both sides of the thoracic shell. The bilateral control of muscle calcium runs counter to the hypothesis that the thorax of flies acts as a single, equally proportional source for mechanical power production for both flapping wings. Collectively, power balancing highlights the precision with which insects adjust their flight motor to changing energetic requirements during aerial steering. This potentially enhances flight efficiency and is thus of interest for the development of technical vehicles that employ bioinspired strategies of power delivery to flapping wings.
Desert ants achieve reliable recruitment across noisy interactions
Authors: Razin Nitzan , Eckmann Jean-Pierre , Feinerman Ofer
Published: March 2013

We study how desert ants,Cataglyphis niger, a species that lacks pheromone-based recruitment mechanisms, inform each other about the presence of food. Our results are based on automated tracking that allows us to collect a large database of ant trajectories and interactions. We find that interactions affect an ant's speed within the nest. Fast ants tend to slow down, whereas slow ones increase their speed when encountering a faster ant. Faster ants tend to exit the nest more frequently than slower ones. So, if an ant gains enough speed through encounters with others, then she tends to leave the nest and look for food. On the other hand, we find that the probability for her to leave the nest depends only on her speed, but not on whether she had recently interacted with a recruiter that has found the food. This suggests a recruitment system in which ants communicate their state by very simple interactions. Based on this assumption, we estimate the information-theoretical channel capacity of the ants’ pairwise interactions. We find that the response to the speed of an interacting nest-mate is very noisy. The question is then how random interactions with ants within the nest can be distinguished from those interactions with a recruiter who has found food. Our measurements and model suggest that this distinction does not depend on reliable communication but on behavioural differences between ants that have found the food and those that have not. Recruiters retain high speeds throughout the experiment, regardless of the ants they interact with; non-recruiters communicate with a limited number of nest-mates and adjust their speed following these interactions. These simple rules lead to the formation of a bistable switch on the level of the group that allows the distinction between recruitment and random noise in the nest. A consequence of the mechanism we propose is a negative effect of ant density on exit rates and recruitment success. This is, indeed, confirmed by our measurements.
Increasing silk fibre strength through heterogeneity of bundled fibrils
Authors: Cranford Steven W.
Published: March 2013

Can naturally arising disorder in biological materials be beneficial? Materials scientists are continuously attempting to replicate the exemplary performance of materials such as spider silk, with detailed techniques and assembly procedures. At the same time, a spider does not precisely machine silk—imaging indicates that its fibrils are heterogeneous and irregular in cross section. While past investigations either focused on the building material (e.g. the molecular scale protein sequence and behaviour) or on the ultimate structural component (e.g. silk threads and spider webs), the bundled structure of fibrils that compose spider threads has been frequently overlooked. Herein, I exploit a molecular dynamics-based coarse-grain model to construct a fully three-dimensional fibril bundle, with a length on the order of micrometres. I probe the mechanical behaviour of bundled silk fibrils with variable density of heterogenic protrusions or globules, ranging from ideally homogeneous to a saturated distribution. Subject to stretching, the model indicates that cooperativity is enhanced by contact through low-force deformation and shear ‘locking’ between globules, increasing shear stress transfer by up to 200 per cent. In effect, introduction of a random and disordered structure can serve to improve mechanical performance. Moreover, addition of globules allows a tuning of free volume, and thus the wettability of silk (with implications for supercontraction).These findings support the ability of silk to maintain near-molecular-level strength at the scale of silk threads, and the mechanism could be easily adopted as a strategy for synthetic fibres.
Attractor local dimensionality, nonlinear energy transfers and finite-time instabilities in unstable dynamical systems with applications to two-dimensional fluid flows
Authors: Sapsis Themistoklis P.
Published: March 2013

We examine the geometry of the finite-dimensional attractor associated with fluid flows described by Navier–Stokes equations and relate its nonlinear dimensionality to energy exchanges between dynamical components (modes) of the flow. Specifically, we use a stochastic framework based on the dynamically orthogonal equations to perform efficient order-reduction and describe the stochastic attractor in the reduced-order phase space in terms of the associated probability measure. We introduce the notion of local fractal dimensionality to describe the geometry of the attractor and we establish a connection with the number of positive finite-time Lyapunov exponents. Subsequently, we illustrate in specific fluid flows that the low dimensionality of the stochastic attractor is caused by the synergistic activity of linearly unstable and stable modes as well as the action of the quadratic terms. In particular, we illustrate the connection of the low-dimensionality of the attractor with the circulation of energy: (i) from the mean flow to the unstable modes (due to their linearly unstable character), (ii) from the unstable modes to the stable ones (due to a nonlinear energy transfer mechanism) and (iii) from the stable modes back to the mean (due to the linearly stable character of these modes).
Thermal shock resistance of solids associated with hyperbolic heat conduction theory
Authors: Wang B. L. , Li J. E.
Published: March 2013

The thermal shock resistance of solids is analysed for a plate subjected to a sudden temperature change under the framework of hyperbolic, non-Fourier heat conduction. The closed form solution for the temperature field and the associated thermal stress are obtained for the plate without cracking. The transient thermal stress intensity factors are obtained through a weight function method. The maximum thermal shock temperature that the plate can sustain without catastrophic failure is obtained according to the two distinct criteria: (i) maximum local tensile stress criterion and (ii) maximum stress intensity factor criterion. The difference between the non-Fourier solutions and the classical Fourier solution is discussed. The traditional Fourier heat conduction considerably overestimates the thermal shock resistance of the solid. This confirms the fact that introduction of the non-Fourier heat conduction model is essential in the evaluation of thermal shock resistance of solids.
Pest trade-offs in technology: reduced damage by caterpillars in Bt cotton benefits aphids
Authors: Hagenbucher Steffen , Wäckers Felix L. , Wettstein Felix E. , Olson Dawn M. , Ruberson John R. , Romeis Jörg
Published: March 2013

The rapid adoption of genetically engineered (GE) plants that express insecticidal Cry proteins derived from
Bacillus thuringiensis
(Bt) has raised concerns about their potential impact on non-target organisms. This includes the possibility that non-target herbivores develop into pests. Although studies have now reported increased populations of non-target herbivores in Bt cotton, the underlying mechanisms are not fully understood. We propose that lack of herbivore-induced secondary metabolites in Bt cotton represents a mechanism that benefits non-target herbivores. We show that, because of effective suppression of Bt-sensitive lepidopteran herbivores, Bt cotton contains reduced levels of induced terpenoids. We also show that changes in the overall level of these defensive secondary metabolites are associated with improved performance of a Bt-insensitive herbivore, the cotton aphid, under glasshouse conditions. These effects, however, were not as clearly evident under field conditions as aphid populations were not correlated with the amount of terpenoids measured in the plants. Nevertheless, increased aphid numbers were visible in Bt cotton compared with non-Bt cotton on some sampling dates. Identification of this mechanism increases our understanding of how insect-resistant crops impact herbivore communities and helps underpin the sustainable use of GE varieties.
New insights into differences in brain organization between Neanderthals and anatomically modern humans
Authors: Pearce Eiluned , Stringer Chris , Dunbar R. I. M.
Published: March 2013

Previous research has identified morphological differences between the brains of Neanderthals and anatomically modern humans (AMHs). However, studies using endocasts or the cranium itself are limited to investigating external surface features and the overall size and shape of the brain. A complementary approach uses comparative primate data to estimate the size of internal brain areas. Previous attempts to do this have generally assumed that identical total brain volumes imply identical internal organization. Here, we argue that, in the case of Neanderthals and AMHs, differences in the size of the body and visual system imply differences in organization between the same-sized brains of these two taxa. We show that Neanderthals had significantly larger visual systems than contemporary AMHs (indexed by orbital volume) and that when this, along with their greater body mass, is taken into account, Neanderthals have significantly smaller adjusted endocranial capacities than contemporary AMHs. We discuss possible implications of differing brain organization in terms of social cognition, and consider these in the context of differing abilities to cope with fluctuating resources and cultural maintenance.
Trabecular bone microstructure scales allometrically in the primate humerus and femur
Authors: Ryan Timothy M. , Shaw Colin N.
Published: March 2013

Most analyses of trabecular microarchitecture in mammals have focused on the functional significance of interspecific variation, but they have not effectively considered the influence of body size or phylogeny on bone architecture. The goals of this study were to determine the relationship between trabecular bone and body size in the humeral and femoral heads of extant primates, and to assess the influence of phylogeny on bone microstructure. Using a sample of 235 individuals from 34 primate species, ranging in body size from 0.06 to 130 kg, the relationships between trabecular bone structure and body size were assessed by using conventional and phylogenetic regression analyses. Bone volume fraction, trabecular thickness and trabecular spacing increase with body size, whereas bone surface-area-to-volume ratio decreases. Shape variables such as trabecular number, connectivity density and degree of anisotropy scale inversely with size. Most of these variables scale with significant negative allometry, except bone surface-area-to-volume ratio, which scales with slight positive allometry. Phylogenetic regressions indicate a relatively weak phylogenetic signal in some trabecular bone variables. These data demonstrate that, relative to body size, large primates have thinner and more tightly packed trabeculae than small primates. The relatively thin trabeculae in large primates and other mammals, coupled with constraints on trabecular thickness related to osteocyte function, suggest that increased skeletal loads in the postcranial joints of large mammals are probably mitigated not only through alterations in trabecular microarchitecture, but also through other mechanisms such as changes in cortical bone distribution, limb posture and gait speed.
Patterns of regulatory activity across diverse human cell types predict tissue identity, transcription factor binding, and long-range interactions
Authors: Sheffield Nathan C. , Thurman Robert E. , Song Lingyun , Safi Alexias , Stamatoyannopoulos John A. , Lenhard Boris , Crawford Gregory E. , Furey Terrence S.
Published: March 2013

Regulatory elements recruit transcription factors that modulate gene expression distinctly across cell types, but the relationships among these remains elusive. To address this, we analyzed matched DNase-seq and gene expression data for 112 human samples representing 72 cell types. We first defined more than 1800 clusters of DNase I hypersensitive sites (DHSs) with similar tissue specificity of DNase-seq signal patterns. We then used these to uncover distinct associations between DHSs and promoters, CpG islands, conserved elements, and transcription factor motif enrichment. Motif analysis within clusters identified known and novel motifs in cell-type-specific and ubiquitous regulatory elements and supports a role for AP-1 regulating open chromatin. We developed a classifier that accurately predicts cell-type lineage based on only 43 DHSs and evaluated the tissue of origin for cancer cell types. A similar classifier identified three sex-specific loci on the X chromosome, including the XIST lincRNA locus. By correlating DNase I signal and gene expression, we predicted regulated genes for more than 500K DHSs. Finally, we introduce a web resource to enable researchers to use these results to explore these regulatory patterns and better understand how expression is modulated within and across human cell types.
Functional Characterization of Type-B Response Regulators in the Arabidopsis Cytokinin Response
Authors: Hill Kristine , Mathews Dennis E. , Kim Hyo Jung , Street Ian H. , Wildes Sarah L. , Chiang Yi-Hsuan , Mason Michael G. , Alonso Jose M. , Ecker Joseph R. , Kieber Joseph J. , Schaller G. Eric
Published: March 2013

Cytokinins play critical roles in plant growth and development, with the transcriptional response to cytokinin being mediated by the type-B response regulators. In Arabidopsis (Arabidopsis thaliana), type-B response regulators (ARABIDOPSIS RESPONSE REGULATORS [ARRs]) form three subfamilies based on phylogenic analysis, with subfamily 1 having seven members and subfamilies 2 and 3 each having two members. Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. To determine which type-B ARRs can functionally substitute for the subfamily 1 members ARR1 or ARR12, we expressed different type-B ARRs from the ARR1 promoter and assayed their ability to rescue arr1 arr12 double mutant phenotypes. ARR1, as well as a subset of other subfamily 1 type-B ARRs, restore the cytokinin sensitivity to arr1 arr12. Expression of ARR10 from the ARR1 promoter results in cytokinin hypersensitivity and enhances shoot regeneration from callus tissue, correlating with enhanced stability of the ARR10 protein compared with the ARR1 protein. Examination of transfer DNA insertion mutants in subfamilies 2 and 3 revealed little effect on several well-characterized cytokinin responses. However, a member of subfamily 2, ARR21, restores cytokinin sensitivity to arr1 arr12 roots when expressed from the ARR1 promoter, indicating functional conservation of this divergent family member. Our results indicate that the type-B ARRs have diverged in function, such that some, but not all, can complement the arr1 arr12 mutant. In addition, our results indicate that type-B ARR expression profiles in the plant, along with posttranscriptional regulation, play significant roles in modulating their contribution to cytokinin signaling.
Reduction of Oxalate Levels in Tomato Fruit and Consequent Metabolic Remodeling Following Overexpression of a Fungal Oxalate Decarboxylase
Authors: Chakraborty Niranjan , Ghosh Rajgourab , Ghosh Sudip , Narula Kanika , Tayal Rajul , Datta Asis , Chakraborty Subhra
Published: March 2013

The plant metabolite oxalic acid is increasingly recognized as a food toxin with negative effects on human nutrition. Decarboxylative degradation of oxalic acid is catalyzed, in a substrate-specific reaction, by oxalate decarboxylase (OXDC), forming formic acid and carbon dioxide. Attempts to date to reduce oxalic acid levels and to understand the biological significance of OXDC in crop plants have met with little success. To investigate the role of OXDC and the metabolic consequences of oxalate down-regulation in a heterotrophic, oxalic acid-accumulating fruit, we generated transgenic tomato (Solanum lycopersicum) plants expressing an OXDC (FvOXDC) from the fungus Flammulina velutipes specifically in the fruit. These E8.2-OXDC fruit showed up to a 90% reduction in oxalate content, which correlated with concomitant increases in calcium, iron, and citrate. Expression of OXDC affected neither carbon dioxide assimilation rates nor resulted in any detectable morphological differences in the transgenic plants. Comparative proteomic analysis suggested that metabolic remodeling was associated with the decrease in oxalate content in transgenic fruit. Examination of the E8.2-OXDC fruit proteome revealed that OXDC-responsive proteins involved in metabolism and stress responses represented the most substantially up- and down-regulated categories, respectively, in the transgenic fruit, compared with those of wild-type plants. Collectively, our study provides insights into OXDC-regulated metabolic networks and may provide a widely applicable strategy for enhancing crop nutritional value.
Tiered Regulation of Sulfur Deprivation Responses in Chlamydomonas reinhardtii and Identification of an Associated Regulatory Factor
Authors: Aksoy Munevver , Pootakham Wirulda , Pollock Steve V. , Moseley Jeffrey L. , González-Ballester David , Grossman Arthur R.
Published: March 2013

During sulfur (S) deprivation, the unicellular alga Chlamydomonas reinhardtii exhibits increased expression of numerous genes. These genes encode proteins associated with sulfate (SO4  2−) acquisition and assimilation, alterations in cellular metabolism, and internal S recycling. Administration of the cytoplasmic translational inhibitor cycloheximide prevents S deprivation-triggered accumulation of transcripts encoding arylsulfatases (ARS), an extracellular polypeptide that may be important for cell wall biosynthesis (ECP76), a light-harvesting protein (LHCBM9), the selenium-binding protein, and the haloperoxidase (HAP2). In contrast, the rapid accumulation of transcripts encoding high-affinity SO4  2− transporters is not affected. These results suggest that there are two tiers of transcriptional regulation associated with S deprivation responses: the first is protein synthesis independent, while the second requires de novo protein synthesis. A mutant designated ars73a exhibited low ARS activity and failed to show increases in ECP76, LHCBM9, and HAP2 transcripts (among others) in response to S deprivation; increases in transcripts encoding the SO4  2− transporters were not affected. These results suggest that the ARS73a protein, which has no known activity but might be a transcriptional regulator, is required for the expression of genes associated with the second tier of transcriptional regulation. Analysis of the ars73a strain has helped us generate a model that incorporates a number of complexities associated with S deprivation responses in C. reinhardtii.
Accurate measurements of intrinsic scattering from window materials by use of a vacuum camera
Authors: Masunaga Hiroyasu , Sakurai Kazuo , Akiba Isamu , Ito Kazuki , Takata Masaki
Published: March 2013

The intrinsic scattering from eight window materials commonly used at synchrotron facilities has been evaluated in the range 0.07 <q< 4 nm−1by the use of a vacuum camera. Poly(oxydiphenylene-pyromellitimide) film, a polyimide film widely used as a window material for vacuum chambers, gave rise to two peaks atq= 0.8 and 4 nm−1. Poly(ether-ether-ketone) gave no Bragg peaks, although the background scattering was relatively high over the entireqrange. When natural mica, synthetic mica, quartz glass, beryllium, silicon nitride and silicon carbide were compared, synthetic mica showed the lowest scattering in the range 0.6 <q< 5 nm−1, indicating that it is the most suitable window material for thisqrange.
CTEAS: a graphical-user-interface-based program to determine thermal expansion from high-temperature X-ray diffraction
Authors: Jones Z.A. , Sarin P. , Haggerty R. P. , Kriven W. M.
Published: March 2013

The coefficient of thermal expansion analysis suite (CTEAS) has been developed to calculate and visualize thermal expansion properties of crystalline materials in three dimensions. The software can be used to determine the independent terms of the second-rank thermal expansion tensor usinghklvalues, correspondingdhkllistings and lattice constants obtained from powder X-ray diffraction patterns collected at different temperatures. UsingCTEAS, a researcher can also visualize the anisotropy of this essential material property in three dimensions. In-depth understanding of the thermal expansion of crystalline materials can be a useful tool in understanding the dependence of the thermal properties of materials on temperature when correlated with the crystal structure.
Upsampling speckle patterns for coherent X-ray diffraction imaging
Authors: Chushkin Y. , Zontone F.
Published: March 2013

Coherent X-ray diffraction imaging is a lensless imaging technique where an iterative phase-retrieval algorithm is applied to the speckle pattern, the far-field diffraction pattern produced by an isolated object. To ensure convergence to a unique solution, the diffraction pattern must be oversampled by a factor of two or more. Since the resolution in real space depends on the maximum wave vector where the intensity is detected,i.e.on the detector field of view, there is a practical limitation on oversampling in reciprocal space and resolution in real space that is ultimately determined by the number of pixels. This work shows that it is possible to reduce the effective pixel size and maintain the detector field of view by applying a linear combination method to shifted diffraction patterns. The feasibility of the method is demonstrated by reconstructing the images of test objects from diffraction patterns oversampled in each dimension by factors of 1.3 and 1.8 only. The described approach can be applied to any diffraction or imaging technique where the resolution is compromised by a large pixel size.
Testing commercial protein crystallography sample mounting loops for movement in a cold-stream
Authors: Alkire R. W. , Rotella F. J. , Duke N. E. C.
Published: March 2013

The purpose of this study was to determine the relative stiffness of the more common sample mounting loops used in protein crystallography experiments and to see if they were moving under the influence of the nitrogen cold-stream gas. The `stress test' involved mounting a silicon single crystal onto a loop and seeing how reproducibly a single reflection could be measured at low temperature using a photodiode detector. Once a general ranking of loop stiffness was obtained, crystals of tetragonal lysozyme were mounted in these loops to investigate if data quality was being degraded as a result of cold-stream gas-induced loop motion. Sample motion was assessed using a differential measurement based on data sets taken at two different κ orientations on the same sample. Four of the eight sample mounting loops tested showed evidence of motion in at least one lysozyme data set using typical sample sizes and normal data collection conditions. These results suggest that loop thickness is key to increased stiffness, and factors such as loop design and frozen solvent can also play an important role.
GSAS-II: the genesis of a modern open-source all purpose crystallography software package
Authors: Toby Brian H. , Von Dreele Robert B.
Published: March 2013

The newly developedGSAS-IIsoftware is a general purpose package for data reduction, structure solution and structure refinement that can be used with both single-crystal and powder diffraction data from both neutron and X-ray sources, including laboratory and synchrotron sources, collected on both two- and one-dimensional detectors. It is intended thatGSAS-IIwill eventually replace both theGSASand theEXPGUIpackages, as well as many other utilities.GSAS-IIis open source and is written largely in object-oriented Python but offers speeds comparable to compiled code because of its reliance on the Python NumPy and SciPy packages for computation. It runs on all common computer platforms and offers highly integrated graphics, both for a user interface and for interpretation of parameters. The package can be applied to all stages of crystallographic analysis for constant-wavelength X-ray and neutron data. Plans for considerable additional development are discussed.
Depth profiling of Fe-implanted Si(100) by means of X-ray reflectivity and extremely asymmetric X-ray diffraction
Authors: Khanbabaee B. , Biermanns A. , Facsko S. , Grenzer J. , Pietsch U.
Published: March 2013

This article reports on surface density variations that are accompanied by ion-beam-induced pattern formation processes on Si. The density profiles perpendicular to Si(100) surfaces were investigated after off-normal implantation with 5 keV Fe+ions at fluences ranging from 1 × 1016to 5 × 1017 ions cm−2. Ripple formation was observed for ion fluences above 1 × 1016 ions cm−2. X-ray reflectivity (XRR) revealed the formation of a nanometre subsurface layer with incorporated Fe. Using XRR, no major dependence of the surface density on the ion fluence could be found. In order to improve the surface sensitivity, extremely asymmetric X-ray diffraction was applied. Depth profiling was achieved by measuring X-ray rocking curves as a function of the decreasing incidence angle down to 0° using this noncoplanar scattering geometry. The density information was extracted from the dynamical Bragg shift of the diffraction peak caused by refraction of the X-ray beam at the air–sample interface. Simulations based on the dynamical theory of X-ray diffraction revealed a decrease of density for increasing ion fluence in a region close to the surface, caused by the amorphization and surface roughening.
5,5-Dimethyl-2,8-diphenyl-5H-dibenzo[b,f]silepine: a synchrotron study
Authors: Clegg William , Harrington Ross W. , Mercier Lauren G. , Piers Warren E.
Published: March 2013

The molecule of the title silepine compound, C28H24Si, lies on a crystallographic general position but has almost exact mirror symmetry. The seven-membered silepine ring has a boat conformation, with a fold angle of 99.99 (9)° between the C—C=C—C stern and the C—Si—C prow. The planes of the phenyl substituents are rotated by 32.23 (6) and 31.80 (7)° out of the planes of the respective fused benzene rings. Similar folded conformations are found for other dibenzo[b,f]silepines, while analogous dibenzo[b,f]borepines, in which the B atom can participate in conjugation, have a more flattened heterocyclic ring.
catena-Poly[1,4-dihydroxy-1,4-diazoniabicyclo[2.2.2]octane [aquatri-μ-chlorido-trichloridodicuprate(II)]]
Authors: Liao Wei-Qiang , Zhou Qin-Qin , Zhang Yi
Published: March 2013

The title compound, {(C6H14N2O2)[Cu2Cl6(H2O)]}n, consists of 1,4-dihydroxy-1,4-diazoniabicyclo[2.2.2]octane dications and one-dimensional inorganic anionic {[Cu2Cl6(H2O)]2−}nchains in which both five-coordinate [CuCl3(H2O)]−and five-coordinate [CuCl3]−units exist. These two distinct type of unit are linked together by one chloride ion and are bridged across centres of inversion to further units of their own type through two chloride ions, giving rise to novel polymeric zigzag chains parallel to thecaxis. The chains are connected by O—H...Cl hydrogen bonds to produceR24(16) ring motifs, resulting in two-dimensional layers parallel to theacplane. These layers are linked into a three-dimensional framework with the organic cationsviaO—H...Cl hydrogen bonds. Hydrogen bonding between the chains, and between the chains and the organic cations, provides stability to the crystal structure.
Fouling and Cleaning Studies in the Food and Beverage Industry Classified by Cleaning Type
Authors: Goode Kylee R. , Asteriadou Konstantia , Robbins Phillip T. , Fryer Peter J.
Published: March 2013

Fouling of food process plant surfaces and the subsequent cleaning needed is a significant industrial problem, and as the cost of water and chemical disposal increases, the problem is becoming more significant. Current literature on water‐based cleaning is reviewed here according to the classification of 3 types of cleaning problems. By doing this, it is hoped that new knowledge can be highlighted applicable to improving industrial cleaning. (i) For type 1 deposits (that can be cleaned with water alone)—Cleaning time appears related to Reynolds number and surface shear stress. An increase in Reynolds number seems to decrease cleaning time. Cleaning temperatures greater than 50 °C do not appear beneficial. (ii) For type 2 deposits (biofilms)—Removal behavior of biofilms seems to be dependent on the microbial aging time on the surface. Keeping a material hydrated on a surface enables easier removal of it with water. a. Water rinsing: Temperature and wall shear stress have varied effects on removal. b. Chemical rinsing: Flow and temperature were seen to have the biggest effect at the start of cleaning, but contact time was more important as cleaning progressed at a given sodium hydroxide solution flow and temperature. (iii) For type 3 deposits (that require a cleaning chemical)—For specifically, protein‐based systems excessive chemical forms a deposit difficult to remove. Increasing wall shear stress and temperature was most beneficial to cleaning rather than concentration. The action of temperature can reduce the use of a chemical for type 2 and type 3 soils. The findings suggest that the right combination of flow characteristics at a given temperature and concentration is crucial to achieving fast cleaning in all cases. There are a number of cleaning monitoring methods at various stages of commercialization that may be capable of monitoring bulk cleaning and cleaning at the surface. To optimize cleaning will require integration of measurement methods into the cleaning process.
The Issue of Undeclared Ingredients in Halal and Kosher Food Production: A Focus on Processing Aids
Authors: Al‐Mazeedi Hani M. , Regenstein Joe M. , Riaz Mian Nadeem
Published: March 2013

Since the early 1900s the food industry has undergone major advances that have led to more than half of the shelves in a modern supermarket being stocked with packaged and processed foods. These boxed, canned, and frozen foods achieve their convenience by using a number of food ingredients and processing aids. The original sources and the details of their processing prior to inclusion in the final food product are not provided to consumers but will determine their acceptability for both halal and kosher food production. While additives are generally declared on a product label, processing aids are not shown on the ingredient statement and thus the consumer is not even aware of their presence. Some additives can be legally grouped into generic categories (such as spices) that also make it difficult for consumers to determine what exactly is in the products they buy and how these products have been processed. Thus, consumers need to put more pressure on the kosher and halal marketing system to use trademarked symbols that represent an organization that the consumer can hold accountable and which provides both the companies and the consumer with confidence in the kosher and/or halal status of the products being offered in the marketplace.
An Overview of the Authentication of Olive Tree and Oil
Authors: Ben‐Ayed Rayda , Kamoun‐Grati Naziha , Rebai Ahmed
Published: March 2013

Adulteration of virgin olive oil with less expensive oils is a serious problem for the public and quality control evaluators of olive oil. That is why olive oil authenticity has become a major issue for producers, consumers, and policy makers. In order to avoid fraud to consumers, it is crucial to study the traceability of olive oil. This review covers 2 important techniques, analytical, and molecular methods, used to characterize olive oil and detect possible adulteration. Several analytical techniques are discussed for the detection of olive oil adulteration by analyzing minor and major compounds of olive oil. However, the chemical composition of olive oil can dramatically change due to the environmental and processing conditions. For this reason, the DNA‐based technologies are gaining greater attention now because they are not influenced by environmental conditions and provide an opportunity for direct comparison of different genetic materials. In this review, we emphasize the great potential of different authenticity methods and discuss their practical implementation in olive oil traceability.
Control of Salmonella Contamination of Shell Eggs—Preharvest and Postharvest Methods: A Review
Authors: Galiş Anca M. , Marcq Christopher , Marlier Didier , Portetelle Daniel , Van Ilie , Beckers Yves , Théwis André
Published: March 2013

Salmonella Enteritidis is one of the most prevalent foodborne pathogen, its main reservoir being considered the shell egg. As the concerns related to the increasing human salmonellosis cases grow, the need for an application of preventive methods either at the farm level or during the processing steps is crucial for a better control of the foodborne outbreaks due to the consumption of this specific food product. This review focuses on the application of preventive methods at the farm level, on preharvest step, in order to reduce the risk of shell eggs contamination with Salmonella, especially S. Enteritidis, through a better control of the laying hens’ infection with this pathogen. As postharvest methods, a 1st approach is the egg storage conditions and the prevention of Salmonella spp. growth and multiplication. In addition, shell eggs may be subjected to eggshell decontamination, to reduce the risk of foodborne outbreaks. Several of these latter mentioned methods are already authorized to be put in place in different countries, as it is the case in the United States of America and Canada. Their efficacy has been proven and their use is regarded by some as mandatory for ensuring shell eggs safety for the consumers.
Blood Monocyte Count May Be a Predictor of Vascular Access Failure in Hemodialysis Patients
Authors: Tanaka Akihito , Ito Yuichi , Tanaka Takamori , Satozaki Satsuki , Hayashi Fumie , Tsuda Itsuyo
Published: March 2013

It has been reported that an increase in the counts of white blood cells (WBC) and their subpopulations is an independent predictor of atherosclerotic events and mortality. On the other hand, vascular access (VA) stenosis is caused by a progressive development of neointimal hyperplasia. We examined the relationship between VA failure and counts of peripheral WBC and their subpopulations in hemodialysis (HD) patients. The study population consisted of 82 patients undergoing regular HD. Twenty‐two patients, who were unstable, were excluded from the study. After one year, we examined the relationship between VA failure and the counts of peripheral WBC and their subpopulations. In the follow‐up period, 21 patients had complicated VA failure. The counts of WBC, neutrophils, lymphocytes, eosinophils, and basophils did not show a significant difference, but a monocyte count of ≥400/μL was shown to indicate a high probability of VA failure. Logistic regression analysis revealed that monocyte count was an independent risk factor of VA failure. The peripheral blood monocyte count may be a predictor of VA failure in HD patients.
Human Nonmercaptalbumin‐2: A Novel Prognostic Marker in Chronic Liver Failure
Authors: Stauber Rudolf E. , Spindelboeck Walter , Haas Josef , Putz‐Bankuti Csilla , Stadlbauer Vanessa , Lackner Carolin , Oettl Karl
Published: March 2013

Albumin is the major plasma protein with several important biological functions. Various disturbances of albumin function have been demonstrated in end‐stage liver disease. These functional disturbances may be related to oxidative modifications of albumin at cysteine‐34, including the irreversibly oxidized human nonmercaptalbumin‐2 (HNA2). The aim of the present study was to relate oxidative modification of albumin to short‐term prognosis in chronic liver failure. Patients with advanced cirrhosis (N = 39), acute‐on‐chronic liver failure (N = 15), and healthy controls (N = 15) were investigated. Three fractions of albumin were separated by high performance liquid chromatography according to the redox state of cysteine‐34. The HNA2 fraction was markedly increased in cirrhotic patients vs. controls and correlated with the degree of chronic liver failure as well as laboratory parameters of liver dysfunction. The HNA2 level tended to be a better predictor of short‐term mortality than the model for end stage liver disease with respect to both 30‐day mortality (area under the receiver operating characteristic curve [AUROC] 0.87 vs. 0.81, NS) and 90‐day mortality (AUROC 0.87 vs. 0.82, NS). In multivariate analysis of prognostic variables, HNA2 was the only remaining predictor of 90‐day mortality. Our results suggest that HNA2, a marker of chronic oxidative stress, is related to liver dysfunction and mortality in cirrhosis and may represent a novel biomarker of chronic liver failure.
Effect of Psychrotrophic Growth on the Milk Fat Fraction at Different Temperatures of Storage
Authors: Izidoro Thiago Braga , Pereira Juliano Gonçalves , Soares Vanessa Mendonça , de Almeida NogueiraPinto José Paes
Published: March 2013

The use of cooling, without using adequate hygienic practices in primary milk production, allows for the growth of psychrotrophic microorganisms that produce the thermoresistant lipases that give milk a rancid flavor. This study aimed to verify how the variation in temperature influences the lipolytic metabolism of the psychrotrophic organisms. Samples of raw milk were collected and submitted to laboratorial analysis as follows: psychrotrophic bacteria count, lipolytic bacteria count, and free fatty acids dosage. Each sample was divided into 3 aliquots and then incubated at 4, 8, and 12 °C, respectively. For each temperature, analyses were repeated after 12, 24, and 48 h of storage. Despite the psychrotrophs growth increase, according to temperature rise, the lipolytic metabolism was not consistent and presented the lower index at 8 °C, suggesting an intensification of the proteolytic compensatory activity at this temperature.
Effect of Levosimendan on Estimated Glomerular Filtration Rate in Hospitalized Patients with Decompensated Heart Failure and Renal Dysfunction
Authors: Hou Zhi‐Qiang , Sun Zhao‐Xia , Su Chong‐Yi , Tan Hui , Zhong Xia , Hu Bo , Zhou Yi , Shang De‐Ya
Published: March 2013

Background

Only limited data of the long‐term effect of levosimendan on renal dysfunction in patients with decompensated heart failure (DHF) have been published previously. To date, there has been no similar study carried out in a Chinese population.

Design and Methods

A prospective, randomized, placebo‐controlled, and double‐blind study was performed to investigate the effect of levosimendan on estimated glomerular filtration rate (eGFR) in DHF patients with renal dysfunction during a 30‐day period. Sixty‐six patients with left ventricular ejection fraction (LVEF) ≤40% and eGFR 15–89 mL/min/1.73 m2 were randomized in a 1:1 ratio to receive a 24‐h infusion with levosimendan or placebo. The B‐type natriuretic peptide (BNP) and eGFR were determined at baseline and day 1, 3, 7, 14, 30 after the start of treatment.

Results

The eGFR levels were obviously enhanced following levosimendan, peaked at 3 days, sustained for at least 14 days, and returned to baseline by day 30 after starting infusion. In contrast, placebo did not induce any significant changes in eGFR levels during the follow‐up. In addition, levosimendan resulted in a distinct decrease in BNP levels in comparison with placebo, and the beneficial effect returned to baseline by day 14 and remained so at day 30 postinfusion.

Conclusions

A 24‐h infusion with levosimendan transiently improved the renal dysfunction compared with placebo in patients with DHF, and its beneficial effects persisted for at least 14 days after the initiation of treatment.
State of Play of Pharmacogenetics and Personalized Medicine in Heart Failure
Authors: Parry Helen M. , Doney Alex S.F. , Palmer, Colin N.A. , Lang Chim C.
Published: March 2013

Heart failure is a common disease with high levels of morbidity and mortality. A large body of evidence guiding treatment shows prognostic benefit with beta‐blockers and angiotensin‐converting enzyme inhibitors, while diuretics are commonly prescribed for symptomatic benefit. Wide variation in drug response between clinically similar patients is a significant problem. Evidence suggests this may have a genetic component. Variation in candidate genes including the beta‐1, beta‐2, and alpha‐2 adrenergic receptors, the renin–angiotensin–aldosterone pathway and genes involved in renal electrolyte handling with diuretics may be important. Single‐nucleotide polymorphisms (SNPs) potentially influencing drug response include the Arg 389 Gly variant and the Ser 49 Gly variant in the beta‐1 adrenergic receptor, the Arg 16 Gly, Gln 27 Glu, and Thr 164 Ile polymorphisms within the beta‐2 adrenergic receptor, an insertion at the 287th base pair in the angiotensin‐converting enzyme and the Gly 264 Ala mutation in the sodium chloride co‐transporter. However, research addressing the clinical significance of these polymorphisms has yielded conflicting results that have had no influence on clinical practice. Genome‐wide association studies may provide an alternative approach to discovering genetic variations influencing drug response, a relatively unchartered area in heart failure management. If future work in this area produces a strong case that variation in drug response has a specific and clinically meaningful genetic component, this could be used to guide drug dosing based on genotype; a step forward in the journey toward personally tailored medicine.
Severe uncertainty and info‐gap decision theory
Authors: Hayes Keith R. , Barry Simon C. , Hosack Geoffrey R. , Peters Gareth W.
Published: March 2013

Info‐gap decision theory (IGDT) seeks to provide a framework for rational decision‐making in situations of severe uncertainty. The theory proposes non‐probabilistic models of uncertainty and requires relatively small information inputs when compared to alternative theories of uncertainty.

Info‐gap decision theory has been criticised because it is based upon models that do not guarantee good decisions in situations of severe uncertainty, where severe means a ‘very large’ uncertainty space and very poor initial estimates of the unknown elements in this space.

This paper reviews the use of this method in ecology where it is receiving interest in applied environmental management applications. Paradoxically, ecological applications of IGDT focus almost exclusively on only one source of uncertainty in ecological problems, model parameter uncertainty, and typically ignore other sources, particularly model structure uncertainty and dependence between parameters, that can be just as severe.

Ecologists and managers contemplating the use of IGDT should carefully consider its strengths and weaknesses, reviewed here, and not turn to it as a default approach in situations of severe uncertainty, irrespective of how this term is defined. We identify four areas of concern for IGDT in practice: sensitivity to initial estimates, localised nature of the analysis, arbitrary error model parameterisation and the ad hoc introduction of notions of plausibility.
Residential aged care: The de facto hospice for New Zealand's older people
Authors: Connolly Martin J , Broad Joanna B , Boyd Michal , Kerse Ngaire , Gott Merryn
Published: March 2013

Aim

To describe short‐term mortality among residential aged care (RAC) residents in Auckland, New Zealand.

Method

Prospective follow‐up, 6828 residents (median age 86 years, 69.8% women) from census‐type survey (10/9/2008); 152 facilities. Mortality data from central sources.

Results

Eight hundred and sixty‐one (12.6%) died by 6 months. Survival related to RAC length of stay before the survey: those resident <1 month (subgroup, n = 380) having 80.0% survival, 1–6 months 83.2% and >6 months 87.4% (P < 0.0001). In those admitted to private hospital from acute hospital (n = 104 of the subgroup of 380), 6‐month mortality was 36.5% (P < 0.0001 vs other ‘short stayers’). Significant mortality predictors were: private hospital admission from acute hospital (hazard ratio (HR) = 2.02), unscheduled GP visit during the prior 2 weeks (HR = 1.90), personal care disability (HR = 1.90) and acute hospital admission number during the previous 2 years (≥3; HR = 5.40).

Conclusions

RAC mortality (especially post admission) is high. Training and resource in the sector should reflect this.
Decreased Levels of Folate Receptor‐β and Reduced Numbers of Fetal Macrophages (Hofbauer Cells) in Placentas from Pregnancies with Severe Pre‐Eclampsia
Authors: Tang Zhonghua , Buhimschi Irina A. , Buhimschi Catalin S. , Tadesse Serkalem , Norwitz Errol , Niven‐Fairchild Tracy , Huang Se‐Te J. , Guller Seth
Published: March 2013

Problem

Pre‐eclampsia (PE), a pregnancy complication of unknown etiology, is a major cause of maternal and fetal mortality and morbidity. Previous studies have described placental genes that are up‐regulated in expression in PE, but few studies have addressed placental gene suppression in this syndrome.

Method of study

Gene profiling and quantitative reverse transcription PCR (qRTPCR) analyses were used to identify genes down‐regulated in placentas from women with severe preterm PE compared with gestational age‐matched normotensive controls with spontaneous preterm birth (sPTB). Western blotting and immunohistochemistry were used to evaluate levels and patterns of cell type–specific protein expression in PE and sPTB group placentas.

Results

Levels of macrophage marker [folate receptor (FR)‐β, CD163, and CD68] mRNA and FR‐β protein were significantly down‐regulated in PE group placentas compared with the sPTB group. Numbers of Hofbauer cells (HBCs, fetal macrophages) and FR‐β protein in these cells were reduced in PE group placentas.

Conclusion

Severe PE is associated with decreased placental expression of FR‐β and a reduction in the number of HBCs. Reduced placental macrophage function is likely to play a key role in the pathophysiology of PE.