bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Cigarette Smoking on Serum Pro- and Anti-Inflammatory Cytokines and Growth Factors
Authors: Daloee Mahdi Hasanzadeh , Avan Amir , Mirhafez Seyed Reza , Kavousi Elahe , Hasanian-Mehr Mehdi , Darroudi Sousan , Tajfard Mohammad , Tayefi Maryam , Qazizade Hanie , Mohammadi Akram , Ferydouni Narges , Ebrahimi Mahmoud , Ghayour-Mobarhan Majid
Published: September 2015

Inflammation plays a key role in the initiation, progression, and clinical manifestation of atherosclerosis. Cigarette smoking is a risk factor for atherosclerosis and cardiovascular disease. The aim of the current study was to investigate the serum concentrations of 12 cytokines and growth factors (EGF, INF-γ, IL-1α/-1β/-2/-4/-6/-8/-10, MCP-1, TNF-α, and VEGF) in an Iranian population, including 192 smokers, comparing these values with concentrations in nonsmokers. One hundred and ninety-two cases were enrolled from the Mashhad University of Medical Sciences. Of these cases, 82 were cigarette smokers and 110 were nonsmokers. Sex and age were matched for the two groups. The serum concentration of 12 cytokines and growth factors were determined using EV-3513-cytokine-biochip arrays, by competitive chemiluminescence immunoassays. The level of serum MCP-1 was significantly ( p < .001) lower in the female group of cigarette smokers (mean = 88.1 dL/ng), compared with nonsmokers (mean = 155.6 dL/ng). There were no significant differences for the other cytokines and growth factors between the groups. Our finding demonstrate the association of MCP-1 with cigarette smoking, supporting further studies in larger population on evaluating the role of cigarette smoking on pro-/anti-inflammatory cytokines.
Dual Benefits of a Student-Assisted Interprofessional Men’s Healthy Lifestyle Pilot Program
Authors: Sealey Rebecca , George Nadene , Gordon Susan , Simmons Lisa
Published: September 2015

Men are less willing to seek health professional advice than women and die more often than women from preventable causes. Therefore, it is important to increase male engagement with health initiatives. This study reports the outcomes of a student-assisted, interprofessional, 12-week health program for overweight adult males. The program included weekly health education and structured, supervised group exercise sessions. Thirteen males (participants) and 18 university students (session facilitators) completed the program. Participants were assessed for a range of health and physical activity measures and health and health profession knowledge. Participants demonstrated significant improvement in activity, knowledge, and perceptions of physical and mental function, and appreciated the guided, group sessions. Students completed an interprofessional readiness questionnaire and reported significant improvement in the understanding of the benefits of interprofessional education and of their role in health care. This program provides evidence of the dual benefit that occurs from the delivery of a student-assisted, interprofessional men’s health program to at-risk community members.
Young Finnish Unemployed Men’s Experiences of Having Participated in a Specific Active Labor Market Program
Authors: Björklund Ove , Häggström Elisabeth , Nyström Lisbet
Published: September 2015

The purpose of the present study was to describe young Finnish unemployed men’s experiences of having participated in a specific active labor market program, intended to fight unemployment and offered at a resource center. Fifteen young unemployed Finnish men in the age range 18 to 27 years were interviewed face-to-face. Purposive sampling was used to increase the variation among informants. The interview texts were analyzed using both manifest and latent qualitative content analysis. The present results reported that the young men felt that they, thanks to the program at the resource center, had acquired daily routines and could ultimately believe in the future. The young men described how they now had a structure, economic support, and that they could return to their daily life. The informants also described how they could see new possibilities and believe in oneself. There is a lack of empirical studies assessing the possible impact of active labor market programs on the unemployed based on participants’ own experiences. Further research is needed to describe and elucidate in more detail the effects of targeted support measures and the needs of unemployed men of different ages and living in different contexts.
Comparative analysis of helmeted impact response of Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms
Authors: Cobb Bryan R , Zadnik Abigail M , Rowson Steven
Published: September 2015

As advanced helmet testing methodologies are developed, the effect headform selection may have on the biomechanical impact response must be considered. This study sought to assess response differences between two of the most commonly used headforms, the Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms, through a series of helmeted impact tests. A total of 180 pendulum impact tests were conducted with three impactor velocities and six impact locations. Test condition–specific significant differences were found between the two headforms for peak linear and angular accelerations (α = 0.05), although differences tended to be small. On average, the National Operating Committee on Standards for Athletic Equipment headform experienced higher peak linear (3.7 ± 7.8%) and angular (12.0 ± 21.6%) accelerations, with some of the largest differences associated with impacts to the facemask. Without the facemask impacts, the average differences in linear (1.8 ± 6.0%) and angular (9.6 ± 15.9%) acceleration would be lower. No significant differences were found in coefficient of variation values for linear (Hybrid III: 2.6 ± 2.3%, National Operating Committee on Standards for Athletic Equipment: 2.0 ± 1.4%) or angular (Hybrid III: 4.9 ± 4.0%; National Operating Committee on Standards for Athletic Equipment: 5.2 ± 5.8%) acceleration. These data have application toward development and validation of future helmet evaluation protocols and standards.
Strategies for treating chronic HCV infection in patients with cirrhosis: latest evidence and clinical outcomes
Authors: Wilder Julius M. , Muir Andrew J.
Published: September 2015

The burden of chronic hepatitis C virus (HCV) infection is significant and growing. HCV is considered one of the leading causes of liver disease worldwide and the leading cause of liver transplantation globally. While those infected is estimated in the hundreds of millions, this is likely an underestimation because of the indolent nature of this disease when first contracted. Approximately 20% of patients with HCV infection will progress to advanced fibrosis and cirrhosis. Those that do are at risk of decompensated liver disease including GI bleeding, encephalopathy, severe lab abnormalities, and hepatocellular carcinoma. Those individuals with advanced fibrosis and cirrhosis have historically been difficult to treat. The backbone of previous HCV regimens was interferon (IFN). The outcomes for IFN based regimens were poor and resulted in increased adverse events among those with advanced fibrosis and cirrhosis. Now, in the era of new direct acting antiviral (DAA’s) medications, there is hope for curing chronic HCV in everyone, including those with advanced fibrosis and cirrhosis. This article provides a review on the most up to date data on the use of DAA’s in patients with advanced fibrosis and cirrhosis. We are at a point where HCV could be truly eradicated, but to do so will require ensuring there are effective and safe treatments for those with advanced fibrosis and cirrhosis.
Use of the Wallstent for infrapopliteal arterial disease and varying vessel diameters
Authors: Rahimi Saum A , Nassiri Naiem
Published: September 2015

There is little description of the Wallstent to treat infrapopliteal arterial disease. This may be a viable option due to its high conformability and ability to elongate in vessels of varying diameters. This case report highlights its use in this clinical situation.
Efficiency and safety of endoscopic resection in the management of subepithelial lesions of the stomach
Authors: Godat Sébastien , Robert Maxime , Caillol Fabrice , Bories Erwan , Pesenti Christian , De Cassan Chiara , Ratone Jean Philippe , Poizat Flora , Giovannini Marc
Published: September 2015

Background

Gastric subepithelial tumors represent a diagnostic and therapeutic challenge, given their histologic heterogeneity and potential malignant behavior.

Objective

The objective of this article is to evaluate the interest, efficiency and safety of endoscopic resection for subepithelial gastric lesions of size <20 mm.

Methods

We conducted a single‐center retrospective study in a tertiary care center.

Results

A total of 33 lesions (10 malignant/23 benign lesions) were studied. Mean histological size was 14.5 mm. Nine EMR, 18 ESD and six hybrid resections were performed. A total of 93.9% lesions were resected in one piece. At six months’ follow‐up, complete and definitive resection was obtained in 96.7% of cases. A vertical resection was insufficient in four cases. One GIST needed a complementary surgical resection, one neuroendocrine tumor was successfully treated by a new ESD session and two pancreatic rests were not additionally treated given the benign character and the absence of residual tissue in endoscopic control after six months. There was only one severe adverse event (2.9%); one pneumoperitoneum with ESD, three bleeding with one ESD and two EMR, always treated conservatively or endoscopically.

Conclusion

Endoscopic resection is safe and should be the procedure of choice for both diagnosis and definitive resection of subepithelial gastric lesions of size under 20 mm.
Efficacy and safety of endoscopic submucosal dissection for elderly patients with superficial squamous esophageal neoplasms
Authors: Peng Chunyan , Shen Shanshan , Xu Guifang , Lv Ying , Zhang Xiaoqi , Ling Tingsheng , Wang Lei , Ding Xiwei , Zou Xiaoping
Published: September 2015

Background

Little is known about the outcomes of endoscopic submucosal dissection in elderly patients with superficial squamous esophageal neoplasms.

Objective

To assess the efficacy and safety of endoscopic submucosal dissection for superficial squamous esophageal neoplasms in elderly patients (≥65 years) compared with non‐elderly patients.

Methods

All patients with superficial squamous esophageal neoplasms receiving endoscopic submucosal dissection were retrospectively analyzed. Among them, 130 were aged 65 or older (group A), and 201 were aged younger than 65 years (group B). Therapeutic efficacy, adverse events, and follow‐up data were evaluated.

Results

Group A had a higher prevalence of concomitant diseases than group B (52.3% vs. 14.9%, respectively). R0 resection rate was 82.3% in group A and 84.6 % in group B (P = 0.717). The curative resection rate was 80.8% in group A and 83.6% in group B (P = 0.653). The rate of procedure‐related non‐cardiopulmonary adverse events was 20.8% in group A and 16.9% in group B (P = 0.377). The incidence of cardiopulmonary adverse events during or after the procedure was 6.2% in group A and 2.5% in group B (P = 0.094). No procedure‐related mortality was reported in either group.

Conclusion

Endoscopic submucosal dissection is effective and safe for treating superficial squamous esophageal neoplasms in elderly patients.
Can People Benefit From Acute Stress? Social Support, Psychological Improvement, and Resilience After the Virginia Tech Campus Shootings
Authors: Mancini Anthony D. , Littleton Heather L. , Grills Amie E.
Published: September 2015

People’s responses to acute stress are largely thought to comprise four prototypical patterns of resilience, gradual recovery, chronic distress, and delayed distress. Here we present evidence of an additional response pattern: psychological improvement. Female survivors of the Virginia Tech shootings ( N = 368) completed assessments before the shootings and at 2, 6, and 12 months post-shooting. Latent growth mixture modeling revealed distinct trajectories of resilience, chronic distress, delayed distress, continuous distress, and improvement. Although resilience was the most common pattern (56%–59%), a trajectory of substantial improvement in anxiety and depression symptoms also emerged among 13.2% and 7.4% of the sample, respectively. In support of this pattern, improvement was distinctively associated with marked increases in perceived social support and gains in interpersonal resources. Findings suggest a more complex understanding of the impact of mass trauma and a key role for dynamic changes in social support following acute stress.
Women’s Experiences Caring for Their Husbands’ Siblings With Developmental Disabilities
Authors: Kuo Yeh-chen
Published: September 2015

A phenomenological method was used in this study to examine the experiences of women caring for the husband’s sibling with developmental disabilities (DDs) with the aim of establishing how and why they came to care and continued to care for them. Three themes emerged after drawing on stories shared by seven women: for the sake of my husband, powerlessness, and trade-off between cost and rewards. The findings of this study show that Taiwanese women accept the cultural norms, thus accepting the caregiving responsibility. Reciprocity did not help determine whether women started caring for the husband’s sibling with DD. However, when an imbalance in reciprocity is present, women experience negative emotions that often result in tension within the family. Positive factors contributed by the husband and parents-in-law can facilitate the work of caregivers by ameliorating physical pain and psychological distress that can occur during the caregiving process.
Circulating Transcript Analysis (NETest) in GEP-NETs Treated With Somatostatin Analogs Defines Therapy
Authors: Ćwikła Jarosław B. , Bodei Lisa , Kolasinska-Ćwikła Agnieszka , Sankowski Artur , Modlin Irvin M. , Kidd Mark
Published: September 2015

Context:

Early and precise delineation of therapeutic responses are key issues in neuroendocrine neoplasm/tumor management. Imaging is currently used but exhibits limitations in sensitivity and specificity. The utility of biomarkers is unclear.

Objective, Setting, and Design:

This prospective cohort study (11 mo) sought to determine whether measurements of circulating neuroendocrine tumor transcripts (NETest) predict responses to somatostatin analogs (SSAs).

Patients:

The test set consisted of 35 SSA-treated gastroenteropancreatic-NETs (RECISTevaluated). The prospective set consisted of 28 SSA-treated Grade 1–Grade 2 GEP-NETs.

Intervention(s):

Whole blood for transcript analysis (NETest) and plasma for Chromogranin A (CgA) (baseline), were collected every 4 weeks (prior to SSA injection). Morphologic (multidetector computed tomography/MRI) and functional imaging (99mTc-[HYNIC, Tyr3]-Octreotide) was undertaken at entry and 6-month intervals until progression (RECIST 1.0).

Main Outcome Measure(s):

Treatment response.

Results:

Test set: NETest (≥80%; scale, 0–100%) differentiated stable (SD) and progressive (PD) disease (P < .0001). Prospective set: 28 patients (26/28 SD) undergoing standard SSA. Grading: 12 G1, 16 G2. SSA Response: progression-free survival: 315 days: 14 (50%) SD, 14 (50%) PD. NETest: Twenty had elevated (≥80%) values; 14 developed PD; six, SD. CgA: Twelve of 28 exhibited elevated baseline values and/or subsequent >25% increase; eight developed PD; four, SD. NETest (P = .002) and grade (P = .054) were the only factors associated with treatment response. Multiple regression analysis established that the NETest could predict disease progression (P = .0002). NETest changes occurred significantly earlier (146 d prior to progression vs 56 d CgA; P < .0001; χ2 = 19) and in more patients (100 vs 57%; P < .02).

Conclusions:

NETest values (80–100%) were more accurate and occurred at a significantly earlier time point than CgA and predicted SSA treatment response.
A novel phosphate-starvation response in fission yeast requires the endocytic function of Myosin I
Authors: Petrini Edoardo , Baillet Victoire , Cridge Jake , Hogan Cassandra J. , Guillaume Cindy , Ke Huiling , Brandetti Elisa , Walker Simon , Koohy Hashem , Spivakov Mikhail , Varga-Weisz Patrick
Published: September 2015

Endocytosis is essential for uptake of many substances into the cell, but how it links to nutritional signalling is poorly understood. Here we show a novel role for endocytosis in regulating the response to low phosphate in Schizosaccharomyces pombe. Loss of function of Myo1, Sla2/End4 or Arp2, proteins involved in the early steps of endocytosis, led to increased proliferation in low phosphate media compared to controls. We show that once cells are deprived of phosphate they undergo a quiescence response that is dependent on the endocytic function of Myo1. Transcriptomic analysis revealed a wide perturbation of gene expression with induction of stress-regulated genes upon phosphate starvation in wildtype but not Δmyo1 cells. Thus, endocytosis plays a pivotal role in mediating the cellular response to nutrients, bridging the external environment and internal molecular functions of the cell.
LPP3 localizes LPA6 signalling to non-contact sites in endothelial cells
Authors: Yukiura Hiroshi , Kano Kuniyuki , Kise Ryoji , Inoue Asuka , Aoki Junken
Published: September 2015

Lysophosphatidic acid (LPA) is emerging as an angiogenic factor, because knockdown of the enzyme that produces it (autotaxin, also known as ENPP2) and its receptors cause severe developmental vascular defects in both mice and fish. In addition, overexpression of autotaxin in mice causes similar vascular defects, indicating that the extracellular amount of LPA must be tightly regulated. Here, we focused on an LPA-degrading enzyme, lipid phosphate phosphatase 3 (LPP3, also known as PPAP2B), and showed that LPP3 was localized in specific cell–cell contact sites of endothelial cells and suppresses LPA signalling through the LPA6 receptor (also known as LPAR6). In HEK293 cells, overexpression of LPP3 dramatically suppressed activation of LPA6. In human umbilical vein endothelial cells (HUVECs), LPA induced actin stress fibre formation through LPA6, which was substantially upregulated by LPP3 knockdown. LPP3 was localized to cell–cell contact sites and was missing in non-contact sites to which LPA-induced actin stress fibre formation mediated by LPA6 was restricted. Interestingly, the expression of LPP3 in HUVECs was dramatically increased after forskolin treatment in a process involving Notch signalling. These results indicate that LPP3 regulates and localizes LPA signalling in endothelial cells, thereby stabilizing vessels through Notch signalling for proper vasculature.
Tropical flatback turtle embryos (Natator depressus) are resilient to the heat of climate change
Authors: Howard Robert , Bell Ian , Pike David A.
Published: September 2015

Climate change is threatening reproduction of many ectotherms by increasing nest temperatures, potentially making it more difficult for females to locate nest sites that provide suitable incubation regimes during embryonic development. Elevated nest temperatures could increase the incidence of embryonic mortality and/or maladaptive phenotypes. We investigated whether elevated nest temperatures reduce hatching success in tropical flatback turtles (Natator depressus) nesting in the Gulf of Carpentaria, Australia. Egg incubation treatments began at 29.5°C and progressively increased in temperature throughout incubation, up to maxima of 31, 32, 33, 34, and 35°C. Elevated nest temperatures did not reduce hatching success or hatchling body size relative to control temperatures (29.5°C), but did speed embryonic development. A combination of sudden exposure to high temperatures during the first two weeks of incubation (>36°C for 48 hours) and prolonged warming throughout incubation (from 29.5-35°C) did not reduce hatching success. We also recorded an unusually high pivotal sex-determining temperature in this flatback turtle population relative to other sea turtle populations; an equal ratio of male and female hatchlings is produced at ∼30.4°C. This adaptation may allow some flatback turtle populations to continue producing large numbers of hatchlings of both sexes under the most extreme climate change scenarios. Some tropical populations of nesting flatbacks may possess important adaptations to high temperature incubation environments which are not found in more southerly temperate populations.
Feather roughness reduces flow separation during low Reynolds number glides of swifts
Authors: van Bokhorst Evelien , de Kat Roeland , Elsinga Gerrit E. , Lentink David
Published: September 2015

Swifts are aerodynamically sophisticated birds with a small arm and large hand wing that provides them with exquisite control over their glide performance. However, their hand wings have a seemingly unsophisticated surface roughness that is poised to disturb flow. This roughness of about 2% chord length is formed by the valleys and ridges of overlapping primary feathers with thick protruding rachides, which make the wing stiffer. An earlier flow study of laminar–turbulent boundary layer transition over prepared swift wings suggests that swifts can attain laminar flow at low angle-of-attack. In contrast, aerodynamic design theory suggests that airfoils must be extremely smooth to attain such laminar flow. In hummingbirds, which have similarly rough wings, flow measurements on a 3D printed model suggests that the flow separates at the leading edge and becomes turbulent well above the rachis bumps in a detached shear layer. The aerodynamic function of wing roughness in small birds is, therefore, not fully understood. Here we perform particle image velocimetry and force measurements to compare smooth versus rough 3D-printed models of the swift hand wing. The high-resolution boundary layer measurements show that the flow over rough wings is indeed laminar at low angle-of-attack and Reynolds number, but becomes turbulent at higher values. In contrast, the boundary layer over the smooth wing forms open laminar separation bubbles that extend beyond the trailing edge. The boundary layer dynamics of the smooth surface varies nonlinear as a function of angle-of-attack and Reynolds number, whereas the rough surface boasts more consistent turbulent boundary layer dynamics. Comparison of the corresponding drag values, lift values, and glide ratios suggests, however, that glide performance is equivalent. The increased structural performance, boundary layer robustness, and equivalent aerodynamic performance of rough wings might have provided small (proto) birds with an evolutionary window to high glide performance.
Body appendages fine-tune posture and moments in freely manoeuvring fruit flies
Authors: Berthé Ruben , Lehmann Fritz-Olaf
Published: September 2015

The precise control of body posture by turning moments is a key to elevated locomotor performance in flying animals. Although elevated moments for body stabilization are typically produced by wing aerodynamics, animals also steer using drag on body appendages, shifting their centre of body mass, and changing moments of inertia owing to active alterations in body shape. To estimate the instantaneous contribution of each of these components for posture control in an insect, we three-dimensionally reconstructed body posture and movements of body appendages in freely manoeuvring fruit flies Drosophila melanogaster by high speed video and experimentally scored drag coefficients of legs and body trunk at low Reynolds number. The results show that the sum of leg- and abdomen-induced yaw moments dominates wing-induced moments during 17% of total flight time but on average is 7.2-times (roll, 3.4-times) smaller during manoeuvring. Our data reject a previous hypothesis on synergistic moment support, indicating that drag on body appendages and mass-shift inhibit rather than support turning moments produced by the wings. Numerical modelling further shows that hind leg extension alters the moments of inertia around the three main body axes of the animal by not more than 6% during manoeuvring, which is significantly less than previously reported for other insects. In sum, yaw, pitch, and roll steering by body appendages likely fine-tunes turning behaviour and body posture, without providing a significant advantage for posture stability and moment support. Motion control of appendages might thus be part of the insect's trimming reflexes that trim out imbalances in moment generation owing to unilateral wing damage and abnormal asymmetries of the flight apparatus.
Relationships among plumage coloration, blood selenium concentrations, and immune responses of adult and nestling tree swallows
Authors: Beck Michelle L. , Hopkins William A. , Hawley Dana M.
Published: September 2015

In a number of taxa, males and females both display ornaments that may be associated with individual quality and could be reliable signals to potential mates or rivals. We examined the iridescent blue/green back and white breast of adult tree swallows (Tachycineta bicolor) to determine if plumage reflectance was related to adult or offspring immune responses. We simultaneously addressed the influence of blood selenium levels and the interaction between blood selenium and plumage coloration on adult and nestling immunity. Selenium is a well-known antioxidant necessary for mounting a robust immune response but its importance in wild birds remains poorly understood. In females, the brightness of white breast coloration was positively associated with bactericidal capacity, but there was no association with blood selenium. In contrast, male bactericidal capacity was associated with an interactive effect between dorsal plumage coloration and blood selenium concentrations. Males with bluer hues and greater blue chroma showed increased bactericidal capacity as blood selenium concentrations increased, while bactericidal capacity declined in greener males at higher blood selenium concentrations. In nestlings, bactericidal capacity was positively associated with nestling blood selenium concentrations and white brightness of both social parents. These results suggest that white plumage reflectance is indicative of quality in tree swallows and that greater attention should be paid to the reflectance of large white plumage patches. Additionally, the role of micronutrients, such as selenium, in mediating relationships between physiology and signals of quality, should be explored further.
Mixed input to olfactory glomeruli from two subsets of ciliated sensory neurons does not seem to impede relay neuron specificity in the crucian carp
Authors: Hansson Kenth-Arne , Døving Kjell B. , Skjeldal Frode M.
Published: September 2015

The consensus view of olfactory processing is that the axons of receptor-specific primary olfactory sensory neurons (OSNs) converge to a small subset of glomeruli, thus preserving the odour identity before the olfactory information is processed in higher brain centres. In the present study, we show that two different subsets of ciliated OSNs with different odorant specificities converge to the same glomeruli. In order to stain different ciliated OSNs in the crucian carp, Carassius carassius, we used two different chemical odorants, a bile salt and a purported alarm substance, together with fluorescent dextrans. The dye is transported within the axons and stains glomeruli in the olfactory bulb. Interestingly, the axons from the ciliated OSNs co-converge to the same glomeruli. Despite intermingled innervation of glomeruli, axons and terminal fields from the two different subsets of ciliated OSNs remained mono-coloured. At four to six days of survival time after staining, the dye was transported trans-synaptically to separately stained axons of relay neurons. These findings demonstrate that specificity of the primary neurons is retained in the olfactory pathways despite mixed innervation of the olfactory glomeruli. These results are discussed in relation to the emerging concepts about non-mammalian glomeruli.
Running, hopping and trotting: tuning step frequency to the resonant frequency of the bouncing system favors larger more compliant animals
Authors: Cavagna G. A. , Legramandi M. A.
Published: September 2015

A long-lasting challenge in comparative physiology is to understand why the efficiency of the mechanical work done to maintain locomotion increases with body mass. It has been suggested that this is due to a more elastic step in larger animals. Here we show that in running, hopping trotting animals and in human running during growth the resonant frequency of the bouncing system decreases with increasing body mass with the same trend surprisingly independent of different animal species and gaits. Step frequency about equals the resonant frequency in trotting and running whereas it is about half the resonant frequency in hopping. The energy loss by elastic hysteresis during loading-unloading the bouncing system from its equilibrium position decreases with increasing body mass. Similarity to a symmetric bounce increases with increasing body mass and, for a given body mass, seems to be maximal in hopping, intermediate in trotting and minimal in running. We conclude that: i) tuning step frequency to the resonant frequency of the bouncing system coincides with a lower hysteresis loss in larger more compliant animals, ii) the mechanism of gait per se affects similarity with a symmetric bounce independent of hysteresis and iii) the greater efficiency in larger animals may be due, at least in part, to a lower hysteresis loss.
A neonicotinoid, imidacloprid, impairs honey bee aversive learning of simulated predation
Authors: Zhang Erica , Nieh James C.
Published: September 2015

Neonicotinoid insecticides can impair bee learning and memory, cognitive features that play a key role in colony fitness because they facilitate foraging. For example, the commonly used neonicotinoid, imidacloprid, reduces honey bee olfactory learning. However, no studies have previously determined if imidacloprid can impair aversive associative learning, although such learning should enhance bee survival by allowing bees to avoid dangerous foraging sites. To mimic attempted predation of foragers, we developed an electro-mechanical predator that consistently attacked foragers with a pinching bite at a fixed force and elicited aversive olfactory learning in a sting extension response (SER) assay. We show that chronic exposure to a sublethal concentration of imidacloprid (25.6 μg/L=20.8 ppb) over 4 days (mean of 1.5 μg/bee/day), significantly impaired aversive short-term learning and memory retention. Control bees showed 9-10 fold higher short-term learning and 8-fold higher memory retention (1 hr later) than imidacloprid-treated bees. Imidacloprid therefore impairs the ability of honey bees to associate a naturalistic predation stimulus, biting, with floral odor compounds. Such learning should enhance bee survival, suggesting that xenobiotics could alter more complex ecological interactions like predator-prey relationships.
Identification and classification of silks using infrared spectroscopy
Authors: Boulet-Audet Maxime , Vollrath Fritz , Holland Chris
Published: September 2015

Lepidopteran silks number in the thousands and display a vast diversity of structures, properties, and industrial potential. To map this remarkable biochemical diversity, we present an identification and screening method based on the infrared spectra of native silk feedstock and cocoons. Multivariate analysis of over 1214 infrared spectra obtained from 35 species allowed us to group silks into distinct hierarchies and a classification that agrees well with current phylogenetic data and taxonomies. This approach also provides information on the relative contents of sericin, calcium oxalate, phenolic compounds, poly-alanine and poly(alanine-glycine) β-sheets. It emerged that the domesticated mulberry silk-moth Bombyx mori represents an outlier compared to other silk moth taxa in terms of spectral properties. Interestingly, Epiphora bauhiniae was found to contain the highest amount of β-sheet reported to date for any wild silk-moth. We conclude our approach provides a new route to determine cocoon chemical composition and in turn a novel, biological as well as material, classification of silks.
The impact of high salt exposure on cardiovascular development in the early chick embryo
Authors: Wang Guang , Zhang Nuan , Wei Yi-fan , Jin Yi-mei , Zhang Shi-yao , Cheng Xin , Ma Zheng-lai , Zhao Shu-zhu , Chen You-peng , Chuai Manli , Hocher Berthold , Yang Xuesong
Published: September 2015

In this study, we showed that high salt exposure dramatically increased chick embryonic mortality during embryo development. As embryonic mortality at early stages mainly results from defects in cardiovascular development, we focused on heart formation and angiogenesis in the following experiments. We found that high salt exposure enhanced the risk of abnormal heart tube looping and blood congestion in the heart chamber. In the presence of high salt, both ventricular cell proliferation and apoptosis increased. The high osmolarity induced by high salt in the ventricular cardiomyocytes resulted in incomplete differentiation, which might be due to reduced Nkx2.5 and GATA4 expression. Blood vessel density and diameter were suppressed by exposure to high salt in both the yolk sac membrane (YSM) and chorioallantoic membrane (CAM) models. In addition, high salt-induced suppression of angiogenesis occurred even at the vasculogenesis stage, as blood island formation was also inhibited by high salt exposure. At the same time, cell proliferation was repressed and cell apoptosis was enhanced by high salt exposure in YSM tissue. Moreover, the reduction in HIF2 and FGF2 gene expression might cause the high salt-suppressed angiogenesis. Interestingly, we showed that high salt exposure caused excess ROS generation in the heart and YSM tissues, which could be partially rescued through the addition of antioxidants. In total, our study suggested that excess ROS generation might play an important role in high-salt induced the heart and angiogenesis defects.
Jet Surface Interaction – Scrubbing Noise in a Transversely Sheared Mean Flow
Authors: Khavaran Abbas
Published: September 2015

Generation of sound due to scrubbing of a jet flow past a nearby solid surface is investigated within the framework of the generalized acoustic analogy theory. The analysis applies to the boundary layer noise generated at and near a wall, and excludes the scattered noise component that is produced at the leading or the trailing edge. While compressibility effects are relatively unimportant at very low Mach numbers, frictional heat generation and thermal gradient normal to the surface could play important roles in generation and propagation of sound in high speed jets of practical interest. A general expression is given for the spectral density of the far field sound as governed by the variable density Pridmore-Brown equation. The propagation Green's function is solved numerically starting with the boundary conditions on the surface and subject to specified mean velocity and temperature profiles between the surface and the observer. It is shown the magnitude of the Green's function decreases with increasing source frequency or jet temperature. The phase remains constant for a rigid surface, but varies with source location when subject to an impedance type boundary condition. The equivalent sources of aerodynamic sound are associated with non-linear momentum flux and enthalpy flux terms that appear in a linear set of equations that govern the fluctuating components of the motion. These multi-pole sources are usually modeled and evaluated with input from a Reynolds-Averaged Navier-Stokes (RANS) solver with an appropriate turbulence model.
Influence of Free Stream Effects on Jet Noise Generation and Propagation within the Goldstein Acoustic Analogy Approach for Fully Turbulent Jet Inflow Boundary Conditions
Authors: Karabasov Sergey A. , Sandberg Richard D.
Published: September 2015

Sound generation and propagation by low-Reynolds number turbulent jets from a DNS database is modelled using the Goldstein acoustic analogy method. In comparison with previous work, the DNS data feature fully resolved turbulent boundary layers at the pipe nozzle exit and include the free-stream flow to study the influence of coflow on effective noise sources. To investigate the statistics of turbulent sources, fourth-order correlation analysis is applied to the DNS data. The results are in reasonable agreement with the conventional Gaussian turbulence statistics source model. For meanflow sound propagation modelling, adjoint linearised Euler equations are solved in the frequency domain. Far-field acoustic predictions are obtained for 40° and 90° observer angle to the jet flow and compared with the reference far-field noise spectra obtained from the same DNS database. To investigate the validity of some commonly made approximations, the results for the locally parallel meanflow propagation model and those for the compact eddy scale approximation are also presented and compared with the reference solution.
The Spectral Shape of Combustion Noise
Authors: Tam Christopher K.W.
Published: September 2015

In this paper, it is proposed that the spectral shape of combustion noise is the same as the similarity spectrum of the noise from the large turbulence structures of high-speed jets. This is true regardless of the turbulence level in the combustion process, the equivalence ratio of the fuel or whether the fuel is a gas or a liquid as long as it is hydrocarbon. At the present time, the mechanism by which combustion noise is generated is still not known. So, it is not possible to prove the correctness of the proposal theoretically or computationally. Here, an empirical approach is followed. Comparisons between the similarity spectrum and many sets of combustion noise spectra are made. The spectra are from open flames, low speed jets, can-type combustor, auxiliary power units and turbofan engines noise measurements. Good agreements are found offering favorable support for the proposal.

This paper is written in honor of Dr. Marvin E. Goldstein, a world-class aero-acoustician, an accomplished applied mathematician and a much-respected long time friend.
Turbulence Statistics for Jet Noise Source Modeling from Filtered PIV Measurements
Authors: Dahl Milo D.
Published: September 2015

Time-resolved, particle image velocimetry was used to measure the velocity fluctuation field at three locations along the lipline of two subsonic jets. The time history data within these fields were filtered in the time domain using empirical mode decomposition to produce two signals from the velocity fluctuation measurements. One signal was for the low-frequency, large-scale turbulent eddy component of the velocity fluctuations and represented the computed results of a large-eddy simulation. The other signal was for the high-frequency, small-scale turbulent eddy component of the velocity fluctuations. This represented the missing scales of a large-eddy simulation. The effect of filtering on the statistical properties of the velocity fluctuations relevant to jet noise prediction modeling were studied. Two-point, space-time, cross correlations were computed for the axial velocity fluctuations. Comparisons were made for the second- and fourth-order two-point correlations, the integral phase velocities, length scales, and time scales, and the frequency dependent phase velocities, length scales, and time scales between the total, large-scale, and small-scale velocity fluctuations.
Effect of a Synthetic Jet Actuator on Airfoil Trailing Edge Noise
Authors: Mankbadi Reda R. , Golubev Vladimir V. , Sansone Marco , Sewell Cody , Nguyen Lap
Published: September 2015

The current work explores the use of Synthetic Jet Actuators (SJAs) for control of the acoustic radiation of a low-speed transitioning airfoil in a uniform stream. In the adopted numerical procedure, the actuator is modeled without its resonator cavity through imposing a simple fluctuating-velocity boundary condition at the bottom of the actuator's orifice. The orifice cavity, with the properly defined boundary condition, is then embedded into the airfoil surface. High-accuracy viscous simulations are then conducted to study the effects of the actuation on sound radiated by the airfoil. Results show that SJA can considerably suppress the radiated sound of the airfoil in uniform incoming stream.
Aeroacoustic Analysis of a High-Speed Open Rotor
Authors: Envia Edmane
Published: September 2015

Owing to their inherent fuel efficiency, there is renewed interest in developing open rotor propulsion systems that are both efficient and quiet. The major contributor to the overall noise of an open rotor system is the propulsor noise, which is produced as a result of the interaction of the airstream with the counter-rotating blades. Prediction of the propulsor noise is, therefore, a necessary ingredient in any approach for designing low-noise open rotor systems that can meet community noise regulations and have acceptable cabin noise levels. To that end, there has been a resurgence of activities in the aeroacoustic modeling of open rotors in recent years. While direct numerical simulations are gaining traction, the bulk of existing prediction capability resides in hybrid approaches in which the aerodynamics of the open rotor system is computed via CFD and is used as input in some appropriate “linear” acoustic model for computing the open rotor noise. At NASA the focus has been on assessing the utility of hybrid approaches for accurately predicting the open rotor tone spectra with an emphasis on the understanding of the role of the various underlying mechanisms of noise generation and their relative importance at different operating conditions. Using high-fidelity aerodynamic simulations of a benchmark (non-proprietary) open rotor blade set, together with acoustic models based on a high-blade-count asymptotic approximation of the Ffowcs-Williams Hawkings equation, tone noise predictions for a number of configurations have been carried out. These aerodynamic and acoustic predictions have been compared with wind tunnel measurements of the benchmark open rotor blade set to establish the capabilities and the limitations of the hybrid approaches. The results suggest that while predicting the absolute spectral levels is difficult, the noise trends are reasonably well predicted by such hybrid approaches at a reasonable overall computational cost.
Investigation of Blast Effects on Double-Skinned Composite Steel Tubular Columns
Authors: Zhang Huidong , Li Zhongxian , Wu Chengqing
Published: September 2015

In recent years, concrete filled double skin steel tube (CFDST) members have gained interest due to its attractive properties such as ease of construction, light weight, high strength and good seismic resistance, and thus it is expected that these members have the potential of being used in construction of buildings. However, there is lack of understanding about the inelastic behaviors of CFDST members under blast loads. In this paper, based on the ConWep airblast loading model, the blast resistance of typical circular CFDST columns used in engineering field is investigated and the multiple failure modes of CFDST columns under blast loading are analyzed. The influence of explosive charge weights and column axial loading condition on the response of CFDST columns are investigated through parametric study. Finally, the direct shear and flexural failure modes of CFDST columns are analyzed, and uncoupled P-I (pressure-impulse) diagrams are obtained based on an equivalent single degree of freedom (SDOF) system. This study helps to understand the non-linear behaviors of CFDST columns subjected to blast loading.
Use of Coupled Smooth-Particle Hydrodynamics/Lagrangian Method in the Simulation of Deformable Projectile Penetration
Authors: Mohotti Damith , Raman Sudharshan N. , Ngo Tuan , Mendis Priyan
Published: September 2015

Mesh-dependent finite element (FE) analysis poses considerable limitations in terms of applying it in large deformation problems. As simulations such as projectile penetration are largely dependent on the material failure criterion, the artificial element erosion technique, which is usually incorporated in mesh-dependent FE techniques, may result in considerable inaccuracies. Therefore, over the last few decades, computational mechanists and engineers have focussed on implementing a mesh-independent analysis method to overcome the numerical instabilities that occur in mesh-dependent FE methods. The smooth-particle hydrodynamics (SPH) technique is one of the methods that is becoming popular among computational mechanists and engineers. The knowledge and understanding of different parameters involved in such simulation is essential prior to its application. In this study, a comprehensive numerical investigation of projectile penetration through monolithic aluminium plates using the SPH technique has been performed. While there have been studies reported in published literatures on the application of the SPH technique on projectile simulations, very limited attention has been placed on investigating the influence of different parameters on the analysis results, especially on deformation of the projectiles. One of the main objectives of this study is to investigate the contribution of different numerical parameters on the simulation of complete penetration of deformable projectiles (5.56 mm x 45 mm NATO standard) through 16 mm AA5061-H116 aluminium plates. The effects of particle density, smooth length, different particle sorting options, and scale factor for smooth length, have been parametrically studied and presented. In addition, the penetration mechanism of projectiles through a metallic target has been numerically and experimentally studied. Numerical simulations show very good agreement with the experimental results. The velocity time histories for monolithic aluminium plates show a “dip” in its velocity reduction, which is considerably difficult to observe in mesh-dependent methods. Three stages of the penetration process have been numerically identified and discussed.
An Evaluation of Shaped Charge Experiments Using Concrete Components
Authors: Esteban Beatriz , Lenhart Lisa-Marie , Rüdiger Lars , Gebbeken Norbert
Published: September 2015

The current contribution presents and evaluates a series of experimental results of shaped charge jets impinging concrete targets. The purpose of this study is threefold. Firstly, the dimensions of the damaged areas, namely the crater, spalling and perforation/penetration regions were measured. Crater dimensions are found to be independent of target thickness whilst spalling dimensions are not. Secondly, the depths of penetration of Normal Strength Concrete (NSC) and Ultra High Performance Concrete (UHPC) were compared. In these experiments the use of UHPC does not provide, on average, a significant reduction in the total depth of penetration, whilst being three times more expensive than NSC. Thirdly, the following three jet properties inside and behind the target were examined: jet velocity, jet mass and jet kinetic energy. The amount by which these properties are reduced in concrete and in air is quantified and compared. As a long term goal, these experiments aim to contribute to the assessment of existing protective structures and, likewise, to the design of future ones.