bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cascading effects of a top predator on intraspecific competition at intermediate and basal trophic levels
Authors: Matassa Catherine M. , Ewanchuk Patrick J. , Trussell Geoffrey C. 
Published: May 2018

Abstract

Predators can impact competition among prey by altering prey density via consumption or by causing prey to modify their traits or foraging behavior. Yet, differences between these two mechanisms may lead to different cascading impacts on lower trophic levels.

Using a crab‐snail‐barnacle rocky intertidal food chain, we tested the effects of predation risk from crabs (top predators) on intraspecific competition among snails (intermediate consumers) and emergent indirect effects on the density of and competition among barnacles (basal resources).

The per capita foraging and growth rates of snails declined with high conspecific density. Predation risk from crabs, which caused even larger reductions in snail foraging and growth, weakened competition among snails, whereas a 45% increase in barnacle density had no detectable effect on snail competition.

Intraspecific competition between barnacles, however, depended on the interactive effects of barnacle density, snail density, and crab predation risk. Barnacles developed hummocking morphologies as they grew and competed for space. Hummock formation (a proxy for competition) increased as a result of either greater initial barnacle density or reduced snail foraging pressure, but these effects depended on predation risk.

The effects of crab predation risk on snail foraging behavior weakened an otherwise strong relationship between barnacle density and hummock development: hummocking increased with barnacle density in the absence of crabs but remained relatively high when crabs were present. In communities with similar final barnacle densities, hummocking was more common in those with crabs than those without crabs.

The extent to which predators can drive trophic cascades by suppressing the foraging rates of their prey is highly context‐dependent: the positive trait‐mediated indirect effect of predators on basal resource abundance is stronger when many prey respond simultaneously to the threat of predation. However, our results demonstrate that top predators can also enhance competition among basal resources even when their indirect effect on resource abundance is relatively weak. Hence, the cascading effects of predators on competition within lower trophic levels may play an important but under‐appreciated role in the dynamics of basal resource populations and the communities they support.

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Estimating external magnetic field differences at high geomagnetic latitudes from a single station
Authors: Beggan Ciarán D. , Billingham Laurence , Clarke Ellen 
Published: May 2018

ABSTRACTProviding an accurate estimate of the magnetic field on the Earth's surface at a location distant from an observatory has useful scientific and commercial applications, such as in repeat station data reduction, space weather nowcasting or aeromagnetic surveying. While the correlation of measurements between nearby magnetic observatories at low and mid‐latitudes is good, at high geomagnetic latitudes () the external field differences between observatories increase rapidly with distance, even during relatively low magnetic activity. Thus, it is of interest to describe how the differences (or errors) in external magnetic field extrapolation from a single observatory grow with distance from its location. These differences are modulated by local time, seasonal and solar cycle variations, as well as geomagnetic activity, giving a complex temporal and spatial relationship. A straightforward way to describe the differences are via confidence intervals for the extrapolated values with respect to distance. To compute the confidence intervals associated with extrapolation of the external field at varying distances from an observatory, we used 695 station‐years of overlapping minute‐mean data from 37 observatories and variometers at high latitudes from which we removed the main and crustal fields to isolate unmodelled signals. From this data set, the pairwise differences were analysed to quantify the variation during a range of time epochs and separation distances. We estimate the 68.3%, 95.4% and 99.7% confidence levels (equivalent to the 1σ, 2σ and 3σ Gaussian error bounds) from these differences for all components. We find that there is always a small non‐zero bias that we ascribe to instrumentation and local crustal field induction effects. The computed confidence intervals are typically twice as large in the north–south direction compared to the east‐west direction and smaller during the solstice months compared to the equinoxes.
Ultrasound‐guided versus free‐hand fine‐needle aspiration cytology of the parotid gland: A single‐centre, retrospective review
Authors: Hung Dorothy Sze‐Wing , Lai Emily Yat‐Ling 
Published: May 2018

AimFine‐needle aspiration cytology (FNAC) is a commonly‐used diagnostic tool to evaluate lesions of the parotid gland. However, ultrasound‐guided FNAC requires expertise, which might not always be immediately available. Free‐hand FNAC can be readily arranged at an outpatient clinic setting, and could shorten waiting time and allow rapid diagnosis of parotid lesions. The aim of our study was to evaluate the accuracy and yield of free‐hand FNAC versus ultrasound‐guided FNAC and its subsequent correlation to the final pathology in order to evaluate its use as a preoperative investigational tool.Patients and MethodsA retrospective review was carried out for patients who underwent superficial, partial or total parotidectomy at the Queen Elizabeth Hospital by the general surgical team between 1 January 2008 and 31 March 2016. Results for 176 surgeries performed were analysed. In total, 155 cases with preoperative FNAC of the parotid were included in the study.ResultsUltrasound‐guided FNAC had 100 per cent specificity, whereas free‐hand FNAC had 98.3 per cent specificity for detecting malignancy. Sensitivity was 92.9 per cent in the ultrasound‐guided FNAC group versus 90 per cent in the free‐hand FNAC group. Ultrasound‐guided FNAC offered a preoperative diagnosis as to whether a mass was benign or malignant in 21 out of 75 patients (28 per cent), while free‐hand FNAC was able to do so in 15 out of 80 patients (18.8 per cent). However, this was not statistically significant (P = 0.188).ConclusionOverall, both ultrasound‐guided and free‐hand FNAC have high sensitivity and specificity for diagnosing malignancy preoperatively. Free‐hand FNAC does not have a lower yield and was not shown to be statistically inferior to ultrasound‐guided FNAC. Free‐hand FNAC is a good alternative in certain cases where the parotid lesion can be easily accessible.
Discovery of Amadori‐Type Conjugates in a Peptide Maillard Reaction and Their Corresponding Influence on the Formation of Pyrazines
Authors: Zou Tingting , Liu Jianbin , Song Huanlu , Liu Ye 
Published: May 2018

AbstractKnowledge of the role of peptides in the Maillard reaction is rather limited. In this study, peptide Maillard reaction model systems were established. Volatile and nonvolatile MRPs (Maillard reaction products) were investigated by GC‐O‐MS and LC‐MS. Carbohydrate module labeling (CAMOLA) experiments were performed to elucidate the carbon skeleton of these compounds. Results showed that the peptide reaction system generated more pyrazines than the free amino acid group. Several new Amadori‐type conjugates were identified as novel Maillard reaction products that could greatly influence the formation of pyrazines. Our work suggested anew mechanism involving these Amadori‐type conjugates and subsequent investigation revealed that the conjugates could be important intermediate products in the reaction between dicarbonyl and dipeptide. Our findings demonstrate anew pyrazine generation mechanism in the dipeptide Maillard reaction.Practical ApplicationWe found that a dipeptide Maillard reaction system generated more pyrazines than a reaction system composed of free amino acids. New cross‐linked peptide‐sugar compounds were identified and found to impact the formation of pyrazines. The results of this study may help in the preparation of thermal reaction flavors using enzymatically hydrolyzed vegetable/animal proteins, which contain a considerable amount of peptides, as one of the major reactants.
Optimization and Scale‐Up Preparation of Egg White Hydrolysate with Angiotensin I Converting Enzyme Inhibitory Activity
Authors: Li Qiyi , Liao Wang , Fan Hongbing , Wu Jianping 
Published: May 2018

AbstractAngiotensin I converting enzyme (ACE) plays an important role in regulation of blood pressure as it converts angiotensin I into angiotensin II (a potent vasoconstrictor). Food protein‐derived ACE inhibitory peptides have been considered as a safer alternative to antihypertensive drugs. In our previous study, three ACE inhibitory peptides were characterized from egg white ovotransferrin and their antihypertensive activity has been validated in spontaneously hypertensive rats. However, it is too costly to prepare these peptides from purified egg white ovotransferrin. The aims of the study were to determine the feasibility of preparing these peptides using egg white and then to optimize the conditions of preparing egg white hydrolysate. Taguchi's method was used to design experiments for optimization, which was established as follows: substrate %, pH of thermoase, time of thermoase digestion, ratio of pepsin to substrate, pH of pepsin, temperature of pepsin, and time of pepsin digestion were 7.5%, pH 8, 90 min, 1%, pH 2.5, 55 °C, and 180 min, respectively. The ACE inhibitory activity (IC50 value) and peptide yield obtained under optimal condition were 30 ± 2 μg/mL and 77.5% ± 0.3%, respectively, which were comparable to the predicted values. Hydrolysate prepared at 150 L reactor showed comparable activity but low peptide yield. Results of this study demonstrated the feasibility of using egg white protein as the starting material to prepare a functional ingredient with potent ACE inhibitory activity.
Preparation of Novel Iodized Salt with Natural Iodine‐Rich Sources by Spray Drying
Authors: Doh Han Sol , Ko Jung A , Park Hyun Jin 
Published: May 2018

AbstractMarine products are rich in not only micronutrients but also iodine content. However, the applications of iodine in marine products in the food industry have not been studied extensively. Therefore, in this study, a novel iodized salt was prepared through a simple method for iodine extraction from natural iodine‐rich sources and spray drying. Laminaria ochroleuca (kombu), Porphyra umbilicalis (nori), Undaria pinnatifida (wakame), and Haliotis discus hannai (abalone) were selected as natural iodine‐rich sources. Through hot water extraction, iodine was extracted from the iodine‐rich sources and iodized salt was successfully prepared with extracted iodine and sea salt by spray drying; extraction efficiency varied from 64.88% to 129.67%; yield, 38.45% to 57.09%; loading efficiency, 99.34% to 124.08%. Chemical interactions were assessed using Fourier transform infrared spectroscopy (FT‐IR) and thermal dynamics was evaluated using differential scanning calorimetry (DSC). Morphology of the salt crystals was studied using scanning electron microscopy (SEM). Furthermore, a storage test was performed to investigate iodine loss due to temperature, relative humidity, and oxidation for 10 weeks in harsh condition. On comparing our salt with commercial products, novel iodized salts displayed similar or superior stability. Therefore, the novel iodized salt prepared in this study can be applied in the food industry.Practical ApplicationIodine is essential trace element and plays a key role in our body. Marine products such as Laminaria ochroleuca (Kombu), Porphyra umbilicalis (nori), Undaria pinnatifida (wakame), and Haliotis discus hannai (abalone) are known as iodine rich‐sources. These products have high level of iodine, but iodine in marine products has not been used widely for food industry. Therefore, using iodine in natural sources, novel iodized salt was prepared with simple method (hot water extraction and spray drying). The novel iodized salt prepared in this study can be applied in the food industry.
Analysis and Evaluation of the Characteristic Taste Components in Portobello Mushroom
Authors: Wang Jinbin , Li Wen , Li Zhengpeng , Wu Wenhui , Tang Xueming 
Published: May 2018

AbstractTo identify the characteristic taste components of the common cultivated mushroom (brown; Portobello), Agaricus bisporus, taste components in the stipe and pileus of Portobello mushroom harvested at different growth stages were extracted and identified, and principal component analysis (PCA) and taste active value (TAV) were used to reveal the characteristic taste components during the each of the growth stages of Portobello mushroom. In the stipe and pileus, 20 and 14 different principal taste components were identified, respectively, and they were considered as the principal taste components of Portobello mushroom fruit bodies, which included most amino acids and 5′‐nucleotides. Some taste components that were found at high levels, such as lactic acid and citric acid, were not detected as Portobello mushroom principal taste components through PCA. However, due to their high content, Portobello mushroom could be used as a source of organic acids. The PCA and TAV results revealed that 5′‐GMP, glutamic acid, malic acid, alanine, proline, leucine, and aspartic acid were the characteristic taste components of Portobello mushroom fruit bodies. Portobello mushroom was also found to be rich in protein and amino acids, so it might also be useful in the formulation of nutraceuticals and functional food.Practical ApplicationThe results in this article could provide a theoretical basis for understanding and regulating the characteristic flavor components synthesis process of Portobello mushroom.
Altering textural properties of fermented milk by using surface‐engineered Lactococcus lactis
Authors: Tarazanova Mariya , Huppertz Thom , Kok Jan , Bachmann Herwig 
Published: May 2018

SummaryLactic acid bacteria are widely used for the fermentation of dairy products. While bacterial acidification rates, proteolytic activity and the production of exopolysaccharides are known to influence textural properties of fermented milk products, little is known about the role of the microbial surface on microbe–matrix interactions in dairy products. To investigate how alterations of the bacterial cell surface affect fermented milk properties, 25 isogenic Lactococcus lactis strains that differed with respect to surface charge, hydrophobicity, cell chaining, cell‐clumping, attachment to milk proteins, pili expression and EPS production were used to produce fermented milk. We show that overexpression of pili increases surface hydrophobicity of various strains from 3–19% to 94–99%. A profound effect of different cell surface properties was an altered spatial distribution of the cells in the fermented product. Aggregated cells tightly fill the cavities of the protein matrix, while chaining cells seem to be localized randomly. A positive correlation was found between pili overexpression and viscosity and gel hardness of fermented milk. Gel hardness also positively correlated with clumping of cells in the fermented milk. Viscosity of fermented milk was also higher when it was produced with cells with a chaining phenotype or with cells that overexpress exopolysaccharides. Our results show that alteration of cell surface morphology affects textural parameters of fermented milk and cell localization in the product. This is indicative of a cell surface‐dependent potential of bacterial cells as structure elements in fermented foods.
Non‐small cell lung cancer brain metastasis screening in the era of positron emission tomography‐CT staging: Current practice and outcomes
Authors: Diaz Mauricio E , Debowski Maciej , Hukins Craig , Fielding David , Fong Kwun M , Bettington Catherine S 
Published: May 2018

AbstractIntroductionSeveral clinical guidelines indicate that brain metastasis screening (BMS) should be guided by disease stage in non‐small cell lung cancer (NSCLC). We estimate that screening is performed more broadly in practice, and patients undergo brain imaging at considerable cost with questionable benefit. Our aim was to quantify the use and detection rate of BMS in a contemporary cohort staged with 18F‐fluorodeoxyglucose positron emission tomography/computed tomography (PET‐CT).MethodsWe conducted a retrospective review of prospectively collected data from three major lung cancer referral centres in Brisbane between January 2011 and December 2015. Patients included had a new diagnosis of NSCLC and had undergone a PET‐CT to stage extra‐cranial disease. BMS was defined as dedicated brain imaging with contrast‐enhanced computed tomography (CE‐CT) or magnetic resonance (MR), in the absence of clinically apparent neurological deficits.ResultsA total of 1751 eligible cases were identified and of these 718 (41%) underwent BMS. The majority had CE‐CT imaging (n = 703). Asymptomatic brain metastases (BM) were detected in 18 patients (2.5%). Of these patients, 12 had concurrent non‐brain metastases. Only six patients (0.8%) had BM alone. The rate of detection increased with N‐stage (P = 0.02) and overall stage (P < 0.001). It was 0.5%, 1%, 1.6% and 7.3% for stage I, II, III and IV respectively. The overall screening rate increased with T‐stage (P = 0.001), N‐Stage (P < 0.001) and overall stage (P < 0.001).ConclusionsNon‐small cell lung cancer BMS practices remain at odds with published guidelines. The low number of occult BMs detected supports the existing international recommendations. Rationalising BMS would minimise the burden on patients and the health care system.
Expression of p16INK4a is a biomarker of chondrocyte aging but does not cause osteoarthritis
Authors: Diekman Brian O. , Sessions Garrett A. , Collins John A. , Knecht Anne K. , Strum Susan L. , Mitin Natalia K. , Carlson Cathy S. , Loeser Richard F. , Sharpless Norman E. 
Published: May 2018

SummaryCellular senescence drives a functional decline of numerous tissues with aging by limiting regenerative proliferation and/or by producing pro‐inflammatory molecules known as the senescence‐associated secretory phenotype (SASP). The senescence biomarker p16INK4a is a potent inhibitor of the cell cycle but is not essential for SASP production. Thus, it is unclear whether p16INK4a identifies senescence in hyporeplicative cells such as articular chondrocytes and whether p16INK4a contributes to pathologic characteristics of cartilage aging. To address these questions, we examined the role of p16INK4a in murine and human models of chondrocyte aging. We observed that p16INK4a mRNA expression was significantly upregulated with chronological aging in murine cartilage (~50‐fold from 4 to 18 months of age) and in primary human chondrocytes from 57 cadaveric donors (r2 = .27, p < .0001). Human chondrocytes exhibited substantial replicative potential in vitro that depended on the activity of cyclin‐dependent kinases 4 or 6 (CDK4/6), and proliferation was reduced in cells from older donors with increased p16INK4a expression. Moreover, increased chondrocyte p16INK4a expression correlated with several SASP transcripts. Despite the relationship between p16INK4a expression and these features of senescence, somatic inactivation of p16INK4a in chondrocytes of adult mice did not mitigate SASP expression and did not alter the rate of osteoarthritis (OA) with physiological aging or after destabilization of the medial meniscus. These results establish that p16INK4a expression is a biomarker of dysfunctional chondrocytes, but that the effects of chondrocyte senescence on OA are more likely driven by production of SASP molecules than by loss of chondrocyte replicative function.
Restoring mitochondrial DNA copy number preserves mitochondrial function and delays vascular aging in mice
Authors: Foote Kirsty , Reinhold Johannes , Yu Emma P. K. , Figg Nichola L. , Finigan Alison , Murphy Michael P. , Bennett Martin R. 
Published: May 2018

SummaryAging is the largest risk factor for cardiovascular disease, yet the molecular mechanisms underlying vascular aging remain unclear. Mitochondrial DNA (mtDNA) damage is linked to aging, but whether mtDNA damage or mitochondrial dysfunction is present and directly promotes vascular aging is unknown. Furthermore, mechanistic studies in mice are severely hampered by long study times and lack of sensitive, repeatable and reproducible parameters of arterial aging at standardized early time points. We examined the time course of multiple invasive and noninvasive arterial physiological parameters and structural changes of arterial aging in mice, how aging affects vessel mitochondrial function, and the effects of gain or loss of mitochondrial function on vascular aging. Vascular aging was first detected by 44 weeks (wk) of age, with reduced carotid compliance and distensibility, increased β‐stiffness index and increased aortic pulse wave velocity (PWV). Aortic collagen content and elastin breaks also increased at 44 wk. Arterial mtDNA copy number (mtCN) and the mtCN‐regulatory proteins TFAM, PGC1α and Twinkle were reduced by 44 wk, associated with reduced mitochondrial respiration. Overexpression of the mitochondrial helicase Twinkle (Tw+) increased mtCN and improved mitochondrial respiration in arteries, and delayed physiological and structural aging in all parameters studied. Conversely, mice with defective mitochondrial polymerase‐gamma (PolG) and reduced mtDNA integrity demonstrated accelerated vascular aging. Our study identifies multiple early and reproducible parameters for assessing vascular aging in mice. Arterial mitochondrial respiration reduces markedly with age, and reduced mtDNA integrity and mitochondrial function directly promote vascular aging.
Pure laparoscopic hepatectomy with augmented reality‐assisted indocyanine green fluorescence versus open hepatectomy for hepatocellular carcinoma with liver cirrhosis: A propensity analysis at a single center
Authors: Cheung Tan To , Ma Ka Wing , She Wong Hoi , Dai Wing Chiu , Tsang Simon Hing Yin , Chan Albert Chi Yan , Chok Kenneth Siu Ho , Lo Chung Mau 
Published: May 2018

AbstractIntroductionLaparoscopic hepatectomy is considered an acceptable treatment of choice in selected patients with primary hepatocellular carcinoma (HCC). Whether indocyanine green (ICG) immunofluorescence, a new technology, may improve surgery outcomes has yet to be tested. The aim of the present study was to investigate and compare the effect of ICG fluorescence imaging on the outcomes of pure laparoscopic hepatectomy and open hepatectomy for primary HCC with background cirrhosis.MethodsFrom January 2015 to June 2016, 20 patients with HCC and liver cirrhosis underwent laparoscopic hepatectomy with ICG immunofluorescence. The outcomes of pure laparoscopic hepatectomy with ICG immunofluorescence were compared with those of open hepatectomy. To avoid selection bias, patients were propensity score matched in a ratio of 1 : 6, with 20 patients in the laparoscopic group and 120 in the open group.ResultsThe laparoscopic group had 20 patients, and the open group had 120 patients. The laparoscopic group had less blood loss (125 vs 450 mL, P < 0.001), a shorter operation time (200 vs 250 min, P = 0.003), and a shorter hospital stay (5 vs 6 days, P < 0.001). The complication rate was 0% in the laparoscopic group compared to 15.0% in the open group (P = 0.135). All patients in the laparoscopic group had negative margin involvement. Four patients (3.3%) in the open resection group had positive margin involvement. Two patients in the ICG immunofluorescence group had additional lesions identified and resected during operation.ConclusionPure laparoscopic hepatectomy with ICG immunofluorescence for primary HCC can be carried out safely with favorable short‐term outcomes even in cirrhotic patients. Better identification of the bile duct structure and better assessment of the tumor resection margin and perfusion are advantages of this new technique.