bluuebunny/crossref_metadata_2025 huggingface dataset:
Guaraná (Paullinia cupana Kunth) effects on LDL oxidation in elderly people: an in vitro and in vivo study
Authors: Portella Rafael de Lima , Barcelos Rômulo Pillon , da Rosa Edovando José Flores , Ribeiro Euler Esteves , da Cruz Ivana Beatrice Mânica , Suleiman Leila , Soares Felix Alexandre Antunes
Published: February 2013

Background

Previous experimental investigations have suggested that guaraná (Paullinia cupanaKunth, supplied by EMBRAPA Oriental) consumption is associated with a lower prevalence of cardiovascular metabolic diseases and has positive effects on lipid metabolism, mainly related to low density lipoprotein (LDL) levels. As LDL oxidation is an important initial event in the development of atherosclerosis, we performedin vitroandin vivostudies to observe the potential effects of guaraná on LDL and serum oxidation.

Methods

Thein vivoprotocol was performed using blood samples from 42 healthy elderly subjects who habitually ingested guaraná (GI) or never ingested guaraná (NG). The formation of conjugated dienes (CDs) was analyzed from serum samples. Thein vitroprotocols were performed using LDL obtained from 3 healthy, non-fasted, normolipidemic voluntary donors who did not habitually ingest guaraná in their diets. The LDL samples were exposed to 5 different guaraná concentrations (0.05, 0.1, 0.5, 1, and 5 μg/mL).

Results

GI subjects demonstrated lower LDL oxidation than did NG subjects (reduction of 27%, p < 0.0014), independent of other variables. In the GI group the total polyphenols was positively associated with LDL levels. Also, guaraná demonstrated a high antioxidant activityin vitro, mainly at concentrations of 1 and 5 μg/mL, demonstrated by suppression of CDs and TBARS productions, tryptophan destruction and high TRAP activity.

Conclusions

Guaraná, similar to other foods rich in caffeine and catechins such as green tea, has some effect on LDL oxidation that could partially explain the protective effects of this food in cardiometabolic diseases.
The effects of apoptosis vulnerability markers on the myocardium in depression after myocardial infarction
Authors: Wang Yiming , Liu Xingde , Zhang Dongfeng , Chen Jianhui , Liu Shuzheng , Berk Michael
Published: February 2013

Background

There is an increased incidence of major depressive disorder (MDD) in individuals after myocardial infarction (MI), but the pathophysiological processes mediating this association are unclear. Our previous study demonstrated an increase in pro-apoptotic pathways in the myocardium and hippocampus in MDD, which was reversed by venlafaxine. This study aimed to attempt to confirm the effects of apoptosis vulnerability markers on the myocardium in a model of depression after myocardial infarction.

Methods

Rats were divided into four groups: sham (N = 8), depression (N = 8, chronic mild unpredictable stress and separation were used in the depression group), MI (N = 13) and post-MI depression (N = 7). The rats in all four groups underwent the same open field and sucrose preference behavioral tests. Evan Blue staining was used to determine the area at risk of myocardial infarction in the left ventricle, and 2,3,5-triphenyl tetrazolium chloride (1.5% TTC) dye was used to detect the size of the myocardial infarction. The expression of bax and bcl-2 protein in the myocardium was investigated by immunohistochemistry, and the mRNA expression of bax, bcl-2 and caspase-3 in the myocardium was investigated by real time RT-PCR. Apoptosis was estimated in the myocardium by measuring the Bax:Bcl-2 ratio.

Results

In the depression and post-MI depression rats, there were significantly decreased movements and total sucrose consumption, modeling behavioral deficits and an anhedonic-like state. In terms of myocardial infarction size, no difference was seen between the MI and post-MI depression groups. There was an up-regulated Bax:Bcl-2 ratio in the depression, MI and post-MI depression groups. Furthermore, in the latter group, there was a greater up-regulated Bax:Bcl-2 ratio. However, caspase-3 did not differ among the four groups.

Conclusions

These results of this animal model suggest that active pro-apoptotic pathways may be involved in the nexus between myocardial infarction and depression. This mechanism may be germane to understanding this relationship in humans.
Possible role of Toxoplasma gondii in brain cancer through modulation of host microRNAs
Authors: Thirugnanam Sivasakthivel , Rout Namita , Gnanasekar Munirathinam
Published: February 2013

Background

The obligate intracellular protozoan parasiteToxoplasma gondiiinfects humans and other warm-blooded animals and establishes a chronic infection in the central nervous system after invasion. Studies showing a positive correlation between anti-Toxoplasmaantibodies and incidences of brain cancer have led to the notion thatToxoplasmainfections increase the risk of brain cancer. However, molecular events involved inToxoplasmainduced brain cancers are not well understood.

Presentation of the hypothesis

Toxoplasmagains control of host cell functions including proliferation and apoptosis by channelizing parasite proteins into the cell cytoplasm and some of the proteins are targeted to the host nucleus. Recent studies have shown thatToxoplasmais capable of manipulating host micro RNAs (miRNAs), which play a central role in post-transcriptional regulation of gene expression. Therefore, we hypothesize thatToxoplasmapromotes brain carcinogenesis by altering the host miRNAome using parasitic proteins and/or miRNAs.

Testing the hypothesis

The miRNA expression profiles of brain cancer specimens obtained from patients infected withToxoplasmacould be analyzed and compared with that of normal tissues as well as brain cancer tissues fromToxoplasmauninfected individuals to identify dysregulated miRNAs inToxoplasma-driven brain cancer cells. Identified miRNAs will be further confirmed by studying cancer related miRNA profiles of the different types of brain cells before and after Toxoplasma infection using cell lines and experimental animals.

Expected outcome

The miRNAs specifically associated with brain cancers that are caused byToxoplasmainfection will be identified.

Implications of the hypothesis

Toxoplasmainfection may promote initiation and progression of cancer by modifying the miRNAome in brain cells. If this hypothesis is true, the outcome of this research would lead to the development of novel biomarkers and therapeutic tools againstToxoplasmadriven brain cancers.
Plasma kallistatin levels in patients with severe community-acquired pneumonia
Authors: Lin Wei-Chieh , Lu Shiou-Ling , Lin Chiou-Feng , Chen Chang-Wen , Chao Lee , Chao Julie , Lin Yee-Shin
Published: February 2013

Introduction

Community-acquired pneumonia (CAP) requiring intensive care unit (ICU) treatment commonly causes acute respiratory failure with high mortality. Kallistatin, an endogenous tissue kallikrein inhibitor, has been reported to be protective in various human diseases. The aim of this study was to assess the correlations of kallistatin with other biomarkers and to determine whether kallistatin levels have a prognostic value in severe CAP.

Methods

Plasma samples and clinical data were prospectively collected from 54 patients with severe CAP requiring ICU admission. Seventeen healthy control subjects were included for comparison. Plasma kallistatin, kallikrein, and other biomarkers of inflammation (tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, IL-8, C-reactive protein (CRP)), and anti-coagulation (protein C, anti-thrombin III) were measured on days 1 and 4 of ICU admission. Comparison between survivors (n = 41) and nonsurvivors (n = 13) was performed.

Results

Plasma kallistatin was significantly consumed in severe CAP patients compared with healthy individuals. Lower day 1 kallistatin levels showed a strong trend toward increased mortality (P = 0.018) and higher day 1 CURB-65 scores (P = 0.004). Plasma kallistatin levels on day 1 of ICU admission were significantly decreased in patients who developed septic shock (P = 0.017) and who had acute respiratory distress syndrome (P = 0.044). In addition, kallistatin levels were positively correlated with anti-thrombin III and protein C and inversely correlated with IL-1β, IL-6, and CRP levels. In a multivariate logistic regression analysis, higher day 1 CURB-65 scores were independent predictors of mortality (odds ratio = 29.9; P = 0.009). Also, higher day 1 kallistatin levels were independently associated with a decreased risk of death (odds ratio, 0.1) with a nearly significant statistical difference (P = 0.056). Furthermore, we found that a cutoff level of 6.5 μg/ml of day 1 kallistatin determined by receiver operating characteristic curves could be used to distinguish between patients who survived in 60 days and those who did not.

Conclusions

These results suggest that kallistatin may serve as a novel marker for severe CAP prognosis and may be involved in the pathogenesis of CAP through antiinflammatory and anticoagulation effects.

See related letter by Katz et al.,http://ccforum.com/content/17/2/429
High-precision estimation of split PS-wave time delays and polarization directions
Authors: Haacke R. Ross
Published: February 2013

The measurement of split PS-wave time delays and polarization directions is notoriously difficult in field data, partly because the signals are small and overprinted by competing mechanisms. This contribution describes a new processing method that suppresses many of the overprinted traveltime and amplitude anomalies, allowing depth-averaged split PS-wave time delays and polarization directions to be measured simply and precisely. These depth-averaged properties are then inverted using a simple forward model, allowing an earth model of split PS-wave time delays and polarization azimuths to be estimated without the need for layer stripping. In the field data used as an example, the processing and inversion methods are used to estimate split PS-wave time delays and polarization directions for ten layers spanning about 500 m depth from the seabed downward. Inversions using data-error covariances estimated from prestack data show model uncertainties less than 0.3 ms of time delay and 3° of polarization azimuth. However, it is clear that if the data-error covariances cannot be estimated from prestack data, due to low fold for example, model uncertainties would rise considerably. Repeating the inversions using data-error covariances of a postulated form leads to a range of maximum-likelihood models. When the data-error covariances cannot be estimated from prestack data, it seems reasonable to report precision levels implied by the spread of maximum-likelihood models, which in this case is up to 0.5 ms of time delay and 20° of polarization azimuth. The principal achievement of this processing and inversion scheme is to constrain a relatively large number of depth layers with similar levels of model uncertainty. The depth resolution available to this new method may have important implications for the development of tight-gas and shale-gas plays, in which variations of stress, strain, and fracture properties in discrete layers are important.
Induced cold tolerance mechanisms depend on duration of acclimation in the chill sensitiveFolsomia candida(Collembola)
Authors: Waagner Dorthe , Holmstrup Martin , Bayley Mark , Sørensen Jesper G.
Published: February 2013

During cold periods ectotherms may improve low temperature tolerance via rapid cold hardening (RCH) over a period of hours and/or long-term cold acclimation (LTCA) during days, weeks or months. However, the effect of duration and the major underlying mechanisms of these processes are still not fully understood. In the present study, the molecular and biochemical responses to RCH (1-3 hours) and LTCA (1-3 days) and the corresponding benefits to survival were investigated using the chill sensitive collembolan, Folsomia candida. We investigated osmolyte accumulation, membrane restructuring and transcription of candidate genes as well as survival benefits in response to RCH and LTCA. RCH induced significant up-regulation of targeted genes encoding enzymes related to carbohydrate metabolic pathways and genes encoding small and constitutively expressed Hsps, indicating that the animals rely on protein protection from a subset of Hsps during RCH and probably also LTCA. The up-regulation of genes involved in carbohydrate metabolic processes initiated during RCH was likely responsible for a transient accumulation of myoinositol during LTCA, which may support the protection of protein and membrane function and structure. Membrane restructuring, composed especially of a significantly increased ratio of unsaturated to saturated phospholipid fatty acids seems to be a supplementary mechanism to activation of Hsps and myoinositol accumulation in LTCA. Thus, the moderate increase in cold shock tolerance conferred by RCH seems to be dominated by effects of heat shock proteins, whereas the substantially better cold tolerance achieved after LTCA is dominated by post-transcriptional processes increasing membrane fluidity and cryoprotectant concentration.
Novel locomotor muscle design in extreme deep-diving whales
Authors: Velten Brandy P. , Dillaman Richard M. , Kinsey Stephen T. , McLellan William A. , Pabst D. Ann
Published: February 2013

Most marine mammals are hypothesized to routinely dive within their aerobic dive limit (ADL). Mammals that regularly perform deep, long-duration dives have locomotor muscles with elevated myoglobin concentrations and are composed of predominantly large, slow-twitch (Type I) fibers with low mitochondrial volume densities (Vmt). These features contribute to extending ADL by increasing oxygen stores and decreasing metabolic rate. Recent tagging studies, however, have challenged the view that two groups of extreme deep-diving cetaceans dive within their ADLs. Beaked whales (Ziphius cavirostris, Cuvier and Mesoplodon densirostris, Blainville) routinely perform the deepest and longest average dives of any air-breathing vertebrate, and short-finned pilot whales (Globicephala macrorhynchus, Gray) perform high-speed sprints at depth. We investigated the locomotor muscle morphology and estimated total body oxygen stores of these cetaceans to determine whether they (a) shared muscle design features with other deep-divers and (b) performed dives within their calculated ADLs. Muscle of both cetaceans displayed high myoglobin concentrations and large fibers, as predicted, but novel fiber profiles for diving mammals. Beaked whales possessed a sprinter's fiber-type profile, composed of approximately 80% fast-twitch (Type II) fibers with low Vmt. Approximately one-third of the muscle fibers of short-finned pilot whales were slow-twitch, oxidative, glycolytic fibers, a rare fiber-type for any mammal. The muscle morphology of beaked whales likely decreases the energetic cost of diving, while that of short-finned pilot whales supports high activity events. Calculated ADLs indicate that, at low metabolic rates, both cetaceans carry sufficient onboard oxygen to aerobically support their dives.
Paired pulse ratio analysis of insulin-induced synaptic plasticity in the snail brain
Authors: Murakami Jun , Okada Ryuichi , Fujito Yutaka , Sakakibara Manabu , Lukowiak Ken , Ito Etsuro
Published: February 2013

Insulin's action in the brain can directly alter cognitive functioning. We have recently shown that molluscan insulin-related peptides are up-regulated following a conditioned taste aversion (CTA) training procedure. In addition, when mammalian insulin is superfused over the isolated Lymnaea central nervous system, it elicits long-term synaptic enhancement at the monosynaptic connection between the cerebral giant cell (CGC) and the buccal 1 (B1) motor neuron. This synaptic enhancement is thought to be a neural correlate of CTA. Here, we examined whether the observed changes in synaptic plasticity were the result of pre- and/or postsynaptic alterations using the paired pulse procedure. The paired pulse ratio was unaltered following insulin application, suggesting that insulin's effects on synaptic plasticity are mediated postsynaptically in the B1 motor neuron. Thus, it was suggested that postsynaptic changes need to be considered when insulin's actions on synaptic plasticity are examined.
Fatigue of insect cuticle
Authors: Dirks Jan-Henning , Parle Eoin , Taylor David
Published: February 2013

Many parts of the insect exoskeleton experience repeated cyclic loading. Although the cuticle of insects and other arthropods is the second most common natural composite material in the world, so far nothing is known about its fatigue properties, despite the fact that fatigue undoubtedly limits the durability of body parts in vivo. For the first time, we here present experimental fatigue data of insect cuticle. Using force-controlled cyclic loading, we determined the number of cycles to failure for hind legs (tibiae) and hind wings of the locust Schistocerca gregaria, as a function of the applied cyclic stress. Our results show that, although both made from cuticle, these two body parts behaved very differently. Wing samples failed after 100,000 cycles when we applied 46% of the stress needed for instantaneous failure (the UTS). Legs, in contrast, were able to sustain a stress of 76% of UTS for the same number of cycles to failure. This can be explained by the difference in the composition and structure of the material and related to the well-known behaviour of engineering composites. Final failure of the tibiae occurred via one of two different failure modes - crack propagation in tension or buckling in compression - indicating that the tibia is evolutionary optimized to resist both failure modes equally. These results are further discussed in relation to the evolution and normal use of these two body parts.
Exposure to multiple cholinergic pesticides impairs olfactory learning and memory in honeybees
Authors: Williamson Sally M. , Wright Geraldine A.
Published: February 2013

Pesticides are important agricultural tools often used in combination to avoid resistance in target pest species, but there is growing concern that their widespread use contributes to the decline of pollinator populations. Pollinators perform sophisticated behaviours while foraging that require them to learn and remember floral traits associated with food, but we know relatively little about the way that combined exposure to multiple pesticides affects neural function and behaviour. The experiments reported here show that prolonged exposure to field-realistic concentrations of the neonicotinoid, imidacloprid, and the organophosphate acetylcholinesterase inhibitor, coumaphos, and their combination impairs olfactory learning and memory formation in the honeybee. Using a method for classical conditioning of proboscis extension, honeybees were trained in either a massed or spaced conditioning protocol to examine how these pesticides affected performance during learning and short- and long-term memory tasks. We found that bees exposed to imidacloprid, coumaphos, or a combination of these compounds, were less likely to express conditioned proboscis extension towards an odor associated with reward. Bees exposed to imidacloprid were less likely to form a long-term memory, whereas bees exposed to coumaphos were only less likely to respond during the short-term memory test after massed conditioning. Both imidacloprid, coumaphos and a combination of the two compounds impaired the bees' ability to differentiate the conditioned odour from a novel odour during the memory test. Our results demonstrate that exposure to sublethal doses of combined cholinergic pesticides significantly impairs important behaviors involved in foraging, implying that pollinator population decline could be the result of a failure of neural function of bees exposed to pesticides in agricultural landscapes.
Hormone Replacement Therapy after Endometrial Cancer
Authors: Manley K , Edey K , Braybrooke J , Murdoch J
Published: February 2013

Endometrial cancer is the fourth most common female cancer in the UK and the most common gynaecological cancer. Quality of life and symptom control needs to be considered in women who enter a surgically induced menopause. Hormone replacement in this population has been controversial to date. The current evidence regarding the safety of estrogen only and combined hormone replacement therapy is discussed in this review. The use of topical vaginal therapies, alternate therapies and the current data regarding testosterone use for symptom control is also outlined.
Noise-reducing algorithms do not necessarily provide superior dose optimisation for hepatic lesion detection with multidetector CT
Authors: Dobeli K L , Lewis S J , Meikle S R , Thiele D L , Brennan P C
Published: February 2013

Objective:

To compare the dose-optimisation potential of a smoothing filtered backprojection (FBP) and a hybrid FBP/iterative algorithm to that of a standard FBP algorithm at three slice thicknesses for hepatic lesion detection with multidetector CT.

Methods:

A liver phantom containing a 9.5-mm opacity with a density of 10 HU below background was scanned at 125, 100, 75, 50 and 25 mAs. Data were reconstructed with standard FBP (B), smoothing FBP (A) and hybrid FBP/iterative (iDose4) algorithms at 5-, 3- and 1-mm collimation. 10 observers marked opacities using a four-point confidence scale. Jackknife alternative free-response receiver operating characteristic figure of merit (FOM), sensitivity and noise were calculated.

Results:

Compared with the 125-mAs/5-mm setting for each algorithm, significant reductions in FOM (p<0.05) and sensitivity (p<0.05) were found for all three algorithms for all exposures at 1-mm thickness and for all slice thicknesses at 25 mAs, with the exception of the 25-mAs/5-mm setting for the B algorithm. Sensitivity was also significantly reduced for all exposures at 3-mm thickness for the A algorithm (p<0.05). Noise for the A and iDose4 algorithms was approximately 13% and 21% lower, respectively, than for the B algorithm.

Conclusion:

Superior performance for hepatic lesion detection was not shown with either a smoothing FBP algorithm or a hybrid FBP/iterative algorithm compared with a standard FBP technique, even though noise reduction with thinner slices was demonstrated with the alternative approaches.

Advances in knowledge:

Reductions in image noise with non-standard CT algorithms do not necessarily translate to an improvement in low-contrast object detection.
Critical appraisal of volumetric-modulated arc therapy compared with electrons for the radiotherapy of cutaneous Kaposi’s sarcoma of lower extremities with bone sparing
Authors: Nicolini G , Abraham S , Fogliata A , Jordaan A , Clivio A , Vanetti E , Cozzi L
Published: February 2013

Objective:

To evaluate the use of volumetric-modulated arc therapy [VMAT, RapidArc® (RA); Varian Medical Systems, Palo Alto, CA] for the treatment of cutaneous Kaposi’s sarcoma (KS) of lower extremities with adequate target coverage and high bone sparing, and to compare VMAT with electron beam therapy.

Methods:

10 patients were planned with either RA or electron beams. The dose was prescribed to 30 Gy, 10 fractions, to mean the planning target volume (PTV), and significant maximum dose to bone was limited to 30 Gy. Plans were designed for 6-MV photon beams for RA and 6 MeV for electrons. Dose distributions were computed with AcurosXB® (Varian Medical Systems) for photons and with a Monte Carlo algorithm for electrons.

Results:

V  90% was 97.3±1.2 for RA plans and 78.2±2.6 for electrons; similarly, V  107% was 2.5±2.2 and 37.7±3.4, respectively. RA met coverage criteria. Concerning bone sparing, D  2% was 29.6±1.1 for RA and 31.0±2.4 for electrons. Although acceptable for bone involvement, pronounced target coverage violations were obtained for electron plans. Monitor units were similar for electrons and RA, although for the latter they increased when superior bone sparing was imposed. Delivery times were 12.1±4.0 min for electrons and 4.8±1.3 min for the most modulated RA plans.

Conclusion:

High plan quality was shown for KS in the lower extremities using VMAT, and this might simplify their management in comparison with the more conventional usage of electrons, particularly in institutes with limited staff resources and heavy workloads.

Advances in knowledge:

VMAT is also dosimetrically extremely advantageous in a typology of treatments where electron beam therapy is mainly considered to be effective owing to the limited penetration of the beams.
Elevated BUBR1 Expression Is Associated with Poor Survival in Early Breast Cancer Patients
Authors: Maciejczyk Adam , Szelachowska Jolanta , Czapiga Bogdan , Matkowski Rafał , Hałoń Agnieszka , Györffy Balázs , Surowiak Paweł
Published: February 2013

BUBR1 (budding uninhibited by benzimidazole-related 1) represents the component of a controlling complex in mitosis. Defects in mitotic control complex result in chromosomal instability and, as a result, disturb the mitotic process. This study was aimed at examining the prognostic value linked to the expression of BUBR1 in a group of patients with breast cancer. We analyzed the expression of BUBR1 in 98 stage II breast cancer patients with a median follow-up of 15 years. Immunohistochemical reactions were performed using monoclonal antibodies against BUBR1. We also studied the prognostic value of BUBR1 mRNA expression using the Kaplan-Meier (KM) plotter, which assessed the effect of 22,277 genes on survival in 2422 breast cancer patients. A background database was established using gene expression data and survival information on 2422 patients downloaded from the Gene Expression Omnibus (GEO; Affymetrix HGU133A and HGU133+2 microarrays). The median relapse-free survival was 6.43 years. Univariate and multivariate analyses showed that higher expression of BUBR1 was typical for cases of shorter overall survival, disease-free time, and disease-specific survival. KM plotter analysis showed that elevated BUBR1 mRNA expression had a negative impact on patients’ relapse-free, distant metastases–free, and overall survival. Elevated BUBR1 expression was associated with poor survival in early stage breast cancer patients.
Histoenzymatic and Morphometric Analysis of Muscle Fiber Type Transformation during the Postnatal Development of the Chronically Food-Deprived Rat
Authors: Ruiz-Rosado Azucena , Fernández-Valverde Francisca , Mariscal-Tovar Silvia , Hinojosa-Rodriguez Cindy Xilonen , Hernández-Valencia Jorge Arturo , Anzueto-Rios Álvaro , Guadarrama-Olmos José Carlos , Segura-Alegría Bertha , Jiménez-Estrada Ismael
Published: February 2013

We analyze the effect of chronic undernourishment on extensor digitorum longus (EDL) muscle maturation in the rat. Cytochrome c oxidase (COX) and alkaline ATPase histoenzymatic techniques were used to determine the relative proportion of different fiber types (oxidative/glycolytic and type I, IIa/IId, or IIb, respectively) and their cross-sectional area in control and undernourished EDL muscles at several postnatal (PN) ages. From PN days 15 to 45, undernourished EDL muscles showed predominance of oxidative and type IIa/IId fibers, but from PN days 60 to 90, there were a larger proportion of oxidative fibers and an equal proportion of type IIa/IId and IIb fibers. Meanwhile, in adult stages (from PN days 130–365), the relative proportion of fiber types in control and undernourished EDL muscles showed no significant differences. In addition, from PN days 15 to 90, there was a significant reduction in the cross-sectional area of all fibers (slow: 13–53%; intermediate: 24–74%; fast: 9–80%) but no differences from PN days 130 to 365. It is suggested that chronic undernourishment affects the maturation of fast-type muscle fibers only at juvenile stages (from PN days 15–45) and the probable occurrence of adaptive mechanisms in muscle fibers, allowing adult rats to counterbalance the alterations provoked by chronic food deprivation.
Hardware Support for Authentication in Cyber Physical Systems
Authors: Sander Oliver , Klimm Alexander , Becker Jürgen
Published: February 2013

The efficiency and benefit of Cyber Physical Systems (CPS) depend heavily on interconnection of individual devices or nodes. Exchange of data, information relevant to an overall task or functionality is the key to many applications such as smart grids, smart cities, and many others. Trustworthiness of data is needed to make such systems successful. To be able to fulfill policies to guarantee the safety of all entities within a CPS and to provide security measures to enforce these cryptographic solutions have to be embedded. As we show in this paper it is possible to integrate security building blocks in ultra-small devices to provide essential properties for secure embedded systems. With proper policies, high cryptographic standards, rising acceptance by users, and provable security and safety measures, CPS will open countless possibilities to increase efficiency in many aspects of our everyday lives.
Observation of Electromigration Voiding in Cu Lines
Authors: Lee Seok-Hee , Bravman John C. , Flinn Paul A. , Arnaud Lucile
Published: February 2013

Cu film characteristics and in-situ observation of electromigration voiding in passivated Cu lines are reported. Measured grain size distribution show a median grain size of 0.4 μm. A 3 μm wide, 800 μm long line passivated with 5000 Å of SiO2 was tested in a high voltage scanning electron microscopy (HVSEM), enabling dynamic in-situ events to be recorded. Electromigration voiding in this line showed some similarity to that previously observed in polygranular Al lines. Transmission electron microscopy was used to study the microstructure of the passivated Cu lines.
Modeling Stress Evolution in Electromigration
Authors: Thouless M. D.
Published: February 2013

Diffusional mechanisms of electromigration and stress relaxation involve the flow of atoms in response to a gradient in chemical potential along an interface. This gradient in chemical potential may be provided by the component of an electric field parallel to the interface, or it may be established by the normal component of stresses along it. In either case, considerations of continuity of the potential dictate that diffusive flow must also be induced along any other boundary that intersects the interface. As an example, in this paper, a model system that contains grain boundaries normal to an applied electric field is analyzed. While the electric field does not directly induce diffusion along these grain boundaries, it is shown that a complimentary flux must be induced along them. The effect of this flux on electromigration is discussed in this paper. Furthermore, it is well-known that non-homogeneous diffusion of matter along boundaries induces elastic distortions and stress gradients. These in turn, influence the diffusion process. The effect of these elastic distortions on the atomic flux has been examined by considering diffusion along a single interface in an elastic medium. Prior studies of diffusional cavity growth have established the magnitudes of non-dimensional time-scales over which the deposition of atoms along the grain boundaries can be assumed to be essentially uniform. Such an assumption considerably simplifies analyses for stress evolution in these problems. The appropriate time-scales over which such a simplification can be made for electromigration are discussed in this paper, and illustrated by some model calculations.
Modeling the Mechanisms of Cu-Enhanced Median Time to Failure in Al-Cu Interconnects Under Electromigration
Authors: Low K. S. , Shih W. C. , Greer A. L. , Ghiti A. , O'Neill A. G.
Published: February 2013

A finite-element model is used to simulate electromigration voiding and failure in Al-Cu interconnects. The modeling includes the fluxes of Al and Cu atoms in the grain-boundary network, and is used to study the mechanisms by which Cu as a solute improves the reliability of Al metallization. A possible mechanism for the Cu to reduce the grain-boundary diffusiv-ity of Al is explored, and it is shown that with appropriate parameters this can reproduce the observed increases in lifetime. Also investigated are the effects of electromigration-induced non-uniformity in the Cu distribution and the role of Al2Cu precipitates as reservoirs for Cu.
Mandibular Phosphaturic Mesenchymal Tumor–Mixed Connective Tissue Variant in a Young Girl
Authors: Luo Lisa , Low Nelson , Vandervord John
Published: February 2013

Phosphaturic mesenchymal tumor–mixed connective tissue variant (PMTMCT) is an extremely rare tumor associated with tumor-induced osteomalacia. The majority occur in middle age and arise from the extremities. This report describes a young girl with PMTMCT arising in the mandible and with no evidence of paraneoplastic syndrome.
Leaf litter quality induces morphological and developmental changes in larval amphibians
Authors: Stoler Aaron B. , Relyea Rick A.
Published: February 2013

Aquatic consumers exhibit many types of inducible phenotypic responses to variation in resource quantity and quality. Leaf litter constitutes a primary resource in freshwater systems, and variation in litter quality can alter the growth and development of aquatic consumers. It is therefore reasonable to hypothesize that variation in litter quality might also induce phenotypic changes in consumers. To test this hypothesis, we exposed two densities of wood frog (Lithobates sylvaticus [Rana sylvatica]) tadpoles to six chemically distinct species of leaf litter from temperate broadleaf and coniferous trees. After several weeks, we quantified development rate, growth rate, intestinal length, size of the oral disc, and five external dimensions of the tadpoles. In addition to substantial changes in growth and development rates, we found striking changes in all morphological responses among different leaf litter environments, including up to 14% longer intestines, 11% deeper tails, and 6% deeper tail muscles. In addition, we found strong relationships of total nitrogen content with all morphological features except growth rate. Our results indicate that differences in resource quality can induce phenotypic changes that are as large as or larger than changes induced by resource quantity. Our study also has substantial implications for the future of aquatic consumers living in forested wetlands given that these forests are currently experiencing widespread changes in tree composition.
Process‐based models are required to manage ecological systems in a changing world
Authors: Cuddington K. , Fortin M.-J. , Gerber L. R. , Hastings A. , Liebhold A. , O'Connor M. , Ray C.
Published: February 2013

Several modeling approaches can be used to guide management decisions. However, some approaches are better fitted than others to address the problem of prediction under global change. Process‐based models, which are based on a theoretical understanding of relevant ecological processes, provide a useful framework to incorporate specific responses to altered environmental conditions. As a result, these models can offer significant advantages in predicting the effects of global change as compared to purely statistical or rule‐based models based on previously collected data. Process‐based models also offer more explicitly stated assumptions and easier interpretation than detailed simulation models. We provide guidelines for identifying the appropriate type of model and level of complexity for management decisions. Finally we outline some of those factors that make modeling for local and regional management under global change a particular challenge: changes to relevant scales and processes, additional sources of uncertainty, legacy effects, threshold dynamics, and socio‐economic impacts.
Effect of Acid Spending on Etching and Acid-Fracture Conductivity
Authors: Pournik M.. , Li L.. , Smith B.. , Nasr-El-Din H.A.. A.
Published: February 2013

In acid fracturing, while the near-wellbore area of the fracture receives live, unspent acid, sections of the fracture farther down the length receive partially spent acid because of the acid's reaction with the rock. As a result, there is a distribution of acid concentration along the fracture length. However, almost all experimental studies on acid-fracture conductivity have been conducted with live acid, which is representative of what occurs near the wellbore.

An experimental study was conducted to investigate the effect of spent acids on the resulting fracture conductivity in a laboratory facility designed to perform acid-fracture-conductivity characterization. Gelled HCl acid systems with different degrees of acid spending were used to etch fractured cores under identical treatment conditions, which were set to mimic field conditions. Detailed etched surface characterization, fluid analysis, and conductivity measurements were performed on acid-etched fracture faces.

Experimental results show that the amount of rock dissolved and the actual etching pattern depend highly on acid concentration. While there was less fracture-face etching with more spent acid systems, the etching pattern also changed with acid spending, which sometimes offset the additional etched volume of unspent acid. As a result, the retained conductivity was generally higher for more spent acid, and the decline in conductivity with closure stress was more subtle with the spent acid, probably because of less weakening of the fracture face.

While there have been many developments in enhancing the etched length of acid-fractured wells, a major reason for the lack of long etched fractures is acid spending along the fracture. In order to understand the etched fracture profile, there is a need to realize how the degree of acid spending limits etching and affects the resulting fracture conductivity. On the basis of the newly discovered effect of acid spending on conductivity, acid-etched length and conductivity can be predicted more accurately and acid-fracture treatments better designed.
Energy to Protein Ratio of Grass–Legume Binary Mixtures under Frequent Clipping
Authors: da Silva Michele Simili , Tremblay Gaëtan F. , Bélanger Gilles , Lajeunesse Julie , Papadopoulos Yousef A. , Fillmore Sherry A. E. , Jobim Clóves Cabreira
Published: February 2013

Forages with a greater energy to protein ratio increase dairy cow N use efficiency. We studied binary mixtures of one legume and one grass species that can increase the ratio of energy availability to protein degradability under frequent clipping. Timothy (Phleum pratense L.), Kentucky bluegrass (Poa pratensis L.), tall fescue [Schedonorus phoenix (Scop.) Holub], orchardgrass (Dactylis glomerata L.), meadow bromegrass (Bromus biebersteinii Roem. & Schult.), and meadow fescue (Festuca elatior auct. Amer.) were seeded with either alfalfa (Medicago sativa L.), white clover (Trifolium repens L.), or birdsfoot trefoil (Lotus corniculatus L.). Carbohydrate and protein fractions (Cornell Net Carbohydrate and Protein System), other nutritive attributes, and dry matter (DM) yield were determined at the first two harvests of the first production year at two sites in eastern Canada. Alfalfa mixtures had a greater ratio of water‐soluble carbohydrates (WSC) to crude protein (CP) and of readily degradable carbohydrate fractions to readily degradable protein fractions than the average of all mixtures; however, they had lower digestibility of neutral detergent fiber and DM, greater fiber concentration, and similar yield. Mixtures with meadow fescue and tall fescue had a greater WSC/CP ratio, yield, and fiber concentration than the average of all mixtures. Mixtures of meadow fescue with any legume species, especially with alfalfa, provided the best combination of a high ratio of WSC/CP (0.70), high yield, and average digestibility. The feasibility of maintaining this desired composition throughout the growing season and for several cropping years remains to be determined.
Dietary Cation–Anion Difference of Forage Species after Chloride Fertilization
Authors: Tremblay Gaëtan F. , Bélanger Gilles , Pelletier Sophie , Lajeunesse Julie , Pageau Denis
Published: February 2013

The dietary cation‐anion difference (DCAD), an indicator of hypocalcaemia risk in dairy cows, has been shown to be decreased by Cl fertilization in a limited number of forage species. Our objective was to assess the response of eight forage species grown in eastern Canada to two Cl fertilization treatments (0 vs. 90 + 50 kg Cl ha−1 applied in early spring and after the first harvest, respectively). Alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.), smooth bromegrass (Bromus inermis Leyss.), meadow bromegrass (Bromus biebersteinii Roemer and J.A. Schultes), tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbyshire], timothy (Phleum pratense L.), reed canarygrass (Phalaris arundinacea L.), and Kentucky bluegrass (Poa pratensis L.) were seeded in 2 yr at one location and harvested twice in the first post‐seeding year of each seeding. The experimental design was a split‐plot with four replicates; species as main plots and Cl fertilization as subplots. Chloride fertilization decreased the DCAD [(Na+ + K+) – (Cl− + S2–)] of all forage species; this decrease ranged from 78 (smooth and meadow bromegrasses) to 201 mmolc kg−1 dry matter (DM) (reed canarygrass) in spring growth and from 88 (Kentucky bluegrass) to 269 mmolc kg−1 DM (tall fescue) in summer regrowth. Species differed in their DCAD with legume species having the highest and timothy, reed canarygrass, and Kentucky bluegrass having the lowest. Producing forage with a DCAD lower than 250 mmolc kg−1 DM is possible without Cl fertilization in Kentucky bluegrass and with Cl fertilization in timothy and reed canarygrass.
Regionalization of models for operational purposes in developing countries: an introduction
Authors: Hughes Denis A.
Published: February 2013

This special edition is a compilation of papers delivered orally at the workshop on regionalization of models for operational purposes in developing countries held during the joint International Association of Hydrological Sciences (IAHS) and International Association of Hydrogeologists (IAH) International Convention in Hyderabad, India during September 2009. The overall theme of the convention was ‘Water: A vital resource under stress – how can science help?’ How science can help solve practical water resources management problems and regionalization of models have been recurring themes in hydrological science over the last few decades. If anything, however, the gap between scientific developments and their application in practice has widened, notably in developing countries where financial and institutional constraints continue to be difficult to overcome. While data scarcity remains a major problem, a combination of developments in models, availability of remotely sensed data and an understanding of the treatment of uncertainty implies that we can overcome many of the data deficiency issues. Unfortunately, this does not seem to be the case in practice, and effective and sustainable technology transfer remains elusive in many developing countries.
The influence of ice season on the physical and ecological conditions in Lake Vanajanselkä, southern Finland
Authors: Leppäranta Matti , Heini Anniina , Jaatinen Elina , Arvola Lauri
Published: February 2013

The results from a winter field study in 2009–2010 in Lake Vanajanselkä are presented. This lake is shallow, eutrophic, and annually ice-covered on average for 5 months. The ice sheet was 41–55 cm thick at the annual maximum, consisting of snow-ice and congelation ice. The e-folding depth of light intensity was 50–100 cm for congelation ice and 5–10 cm for snow. The water body had a 4-m thick upper mixed layer and lower continuously stratified layer. Fall cooling process was crucial to determine the temperature of the lower layer at freeze-up, anything within 0–4 °C. Oxygen concentration decreased in winter, especially close to the bottom sediments, and carbon dioxide concentration increased due to respiration activity. Phytoplankton production and biomass level were low or very low and, therefore, heterotrophic and mixotrophic species were abundant. Oxygen depletion in the hypolimnium had several chemical and ecological consequences, such as release of phosphorus from the bottom sediments. In spring, just before the ice-out, photosynthesis was at a high level beneath the ice due to improved light conditions and started to elevate the oxygen concentration in the topmost water layer.
Atmospheric teleconnection patterns associated with severe and mild ice cover on the Great Lakes, 1963–2011
Authors: Bai Xuezhi , Wang Jia
Published: February 2013

Atmospheric teleconnection circulation patterns associated with severe and mild ice cover over the Great Lakes are investigated using the composite analysis of lake ice data and National Center of Environmental Prediction (NCEP) reanalysis data for the period 1963–2011. The teleconnection pattern associated with the severe ice cover is the combination of a negative North Atlantic Oscillation (NAO) or Arctic Oscillation (AO) and negative phase of Pacific/North America (PNA) pattern, while the pattern associated with the mild ice cover is the combination of a positive PNA (or an El Niño) and a positive phase of the NAO/AO. These two extreme ice conditions are associated with the North American ridge–trough variations. The intensified ridge–trough system produces a strong northwest-to-southeast tilted ridge and trough and increases the anomalous northwesterly wind, advecting cold, dry Arctic air to the Great Lakes. The weakened ridge–trough system produces a flattened ridge and trough, and promotes a climatological westerly wind, advecting warm, dry air from western North America to the Great Lakes. Although ice cover for all the individual lakes responds roughly linearly and symmetrically to both phases of the NAO/AO, and roughly nonlinearly and asymmetrically to El Niño and La Niña events, the overall ice cover response to individual NAO/AO or Niño3.4 index is not statistically significant. The combined NAO/AO and Niño3.4 indices can be used to reliably project severe ice cover during the simultaneous –NAO/AO and La Niña events, and mild ice cover during the simultaneous +NAO/AO and El Niño events.
Simulations of water quality and oxythermal cisco habitat in Minnesota lakes under past and future climate scenarios
Authors: Fang Xing , Alam Shoeb R. , Stefan Heinz G. , Jiang Liping , Jacobson Peter C. , Pereira Donald L.
Published: February 2013

A deterministic, process-oriented, dynamic and one-dimensional year-round lake water quality model, MINLAKE2010, was developed for water temperature (T) and dissolved oxygen (DO) simulations to study impacts of climate warming on lake water quality and cisco fish habitat. The DO model is able to simulate metalimnetic oxygen maxima in vertical DO profiles of oligotrophic lakes. The model was calibrated with profile data from the 28 study lakes in Minnesota; two-thirds of them are deep mesotrophic/oligotrophic lakes that support cisco, a coldwater fish species. The average standard error of estimate against measured data was 1.47 °C for T and 1.50 mg/L for DO. Oxythermal habitat parameter TDO3 (T at DO = 3 mg/L) was determined from simulated daily T and DO profiles under past and future climate scenarios in the 28 study lakes. Average annual maximum TDO3 (TDO3AM) for the 28 study lakes is projected to increase on the average of 3.2 °C under the MIROC 3.2 future scenario, while the occurrence day of TDO3AM is not much different under past and future climate scenarios. Both physical processes (mixing characteristics related to lake geometry ratio) and trophic status control temperature and DO characteristics and then affect cisco habitat in a lake.