bluuebunny/crossref_metadata_2025 huggingface dataset:
Youth Program Adult Leader's Directive Assistance and Autonomy Support and Development of Adolescents’ Agency Capacity
Authors: Hansen David M. , Moore E. Whitney , Jessop Nadia
Published: October 2017

Developing a capacity for exercising agency is an important developmental task of adolescence. Many organized youth programs provide adolescents opportunities to build their capacity to exercise agency. The researchers tested hypotheses that adult youth program leader's directive assistance and autonomy support would promote adolescents’ capacity for agency. They surveyed 441 high school adolescents and 11 adult advisors from 10 Future Farmers of America chapters twice over 2 years. Adolescents self‐reported on their capacity for agency and advisors reported on each adolescent's capacity. Directive assistance and autonomy support correlated with the capacity for agency within both time points. Only autonomy support predicted adolescents’ capacity for agency over time. Implications of leader's support for adolescents’ capacity for exercising agency are discussed.
A review of issues of nomenclature and taxonomy of Hypericum perforatum L. and Kew's Medicinal Plant Names Services
Authors: Dauncey Elizabeth Anne , Irving Jason Thomas Whitley , Allkin Robert
Published: October 2017

Objectives

To review which names are used to refer to Hypericum perforatum L. in health regulation and medicinal plant references, and the potential for ambiguity or imprecision.

Key findings

Structured searches of Kew's Medicinal Plant Names Services Resource, supplemented with other online bibliographic resources, found that the scientific name Hypericum perforatum L. is used consistently in the literature, but variation between subspecies is rarely considered by researchers. Research is still published using only the common name ‘St John's wort’ despite it being imprecise; at least 80 other common names are also used for this plant in multiple languages.

Ambiguous and alternative plant names can lead to ineffective regulation, misinterpretation of literature, substitution of raw material or the failure to locate all published research. Kew's Medicinal Plant Names Services (MPNS) maps all names used for each plant in medicinal plant references onto current taxonomy, thereby providing for disambiguation and comprehensive access to the regulations and references that cite that plant, regardless of the name used. MPNS also supplies the controlled vocabulary for plant names now required for compliance with a new standard (Identification of Medicinal Products, IDMP) adopted by medicines regulators worldwide.
Role of serum albumin as a nanoparticulate carrier for nose-to-brain delivery of R-flurbiprofen: implications for the treatment of Alzheimer's disease
Authors: Wong Ling Rong , Ho Paul C
Published: October 2017

Objectives

R-flurbiprofen (R-FP) was found to offer neuroprotective effects by inhibiting mitochondrial calcium overload induced by β-amyloid peptide toxicity in Alzheimer's disease (AD). However, poor brain penetration after oral administration posed a challenge to its further development for AD treatment. In this study, we investigated the potential of serum albumin as nanoparticulate carriers for nose-to-brain delivery of R-FP to improve its brain accumulation.

Methods

Mice were subjected to three treatment groups: (1) intranasal R-FP solution, (2) oral R-FP solution and (3) intranasal R-FP albumin nanoparticles. We also investigated whether the in-vivo R-FP level achieved in the brain afforded by intranasal administration of R-FP nanoparticles had any effect on mitochondrial respiratory activity in an in-vitro AD model.

Key findings

Our in-vivo experiments demonstrate that the intranasal administration of serum albumin-based R-FP nanoparticles achieved higher brain-to-plasma ratio profile as compared to intranasal and oral administration of a simple R-FP solution. We observed significantly improved basal and maximal mitochondrial respiration in cells treated with R-FP albumin nanoparticles at in-vivo brain concentration.

Conclusions

Serum albumin-based nanoparticles administered via the nasal route may be a viable approach in delivering therapeutic agents to the brain to alleviate mitochondrial dysfunction in AD.
Gene expression and morphological changes in the intestinal mucosa associated with increased permeability induced by short‐term fasting in chickens
Authors: Gilani S. , Howarth G. S. , Nattrass G. , Kitessa S. M. , Barekatain R. , Forder R. E. A. , Tran C. D. , Hughes R. J.
Published: October 2017

Short‐term fasting for 4.5 and 9 hr has been demonstrated to increase intestinal permeability (IP) in chickens. This study aimed to investigate the effects of 0, 4.5, 9 and 19.5 hr fasting on intestinal gene expression and villus‐crypt architecture of enterocytes in jejunal and ileal samples. On day 38, Ross‐308 male birds were fasted according to their group and then euthanised. Two separate intestinal sections (each 2 cm long, jejunum and ileum) were collected. One section was utilised for villus height and crypt depth measurements. The second section was snap‐frozen in liquid nitrogen for quantitative polymerase chain reaction (qPCR) analysis of tight junction proteins (TJP) including claudin‐1, claudin‐3, occludin, zonula occludens (ZO‐1, ZO‐2), junctional adhesion molecules (JAM) and E‐cadherin. Additionally genes involved in enterocyte protection including glucagon‐like peptide (GLP‐2), heat‐shock protein (HSP‐70), intestinal alkaline phosphatase (IAP), mammalian target of rapamycin (mTOR), toll‐like receptors (TLR‐4), mucin (MUC‐2), cluster differentiation (CD‐36) and fatty acid‐binding protein (FABP‐6) were also analysed. Normally distributed data were analysed using one‐way analysis of variance ANOVA. Other data were analysed by non‐parametric one‐way ANOVA. Villus height and crypt depth were increased (p < .05) only in the ileum after fasting for 4.5 and 9 hr compared with non‐fasting group. mRNA expression of claudin‐3 was significantly reduced in the ileum of birds fasted for 9 and 19.5 hr, suggesting a role in IP modulation. However, all other TJP genes examined were not statistically different from control. Nevertheless, ileal FABP‐6 of all fasted groups was significantly reduced, which could possibly be due to reduced bile acid production during fasting.
More advanced disease and worse survival in cryptogenic compared to viral hepatocellular carcinoma
Authors: Jun Tomi W. , Yeh Ming‐Lun , Yang Ju Dong , Chen Vincent L. , Nguyen Pauline , Giama Nasra H. , Huang Chung‐Feng , Hsing Ann W. , Dai Chia‐Yen , Huang Jee‐Fu , Chuang Wan‐Long , Roberts Lewis R. , Yu Ming‐Lung , Nguyen Mindie H.
Published: October 2017

Background & Aims

Although hepatitis B virus (HBV) and hepatitis C virus (HCV) infections remain major risk factors for hepatocellular carcinoma (HCC), non‐viral causes of HCC, particularly non‐alcoholic fatty liver disease (NAFLD), are becoming increasingly prevalent. The aim of this study was to compare the clinical characteristics and survival of cryptogenic and viral HCC.

Methods

We conducted a retrospective cohort study involving 3878 consecutive HCC patients seen at two tertiary centres in the United States and one in Taiwan from 2004 to 2014. We compared the clinical characteristics, treatment and survival of patients by underlying aetiology: cryptogenic (n = 696), HBV (n = 1304) or HCV (n = 1878).

Results

Cirrhosis was present in 66.8% of the cryptogenic HCC patients, compared with 74.7% of HBV‐related HCC (HBV‐HCC) (P = .001) and 85.9% of HCV‐HCC (P < .001). Compared to viral HCC, cryptogenic HCC patients presented with larger tumours and at later stages of disease. Five‐year overall survival was 16.3% among cryptogenic HCC patients compared with 31.9% among HBV‐HCC patients and 27.7% among HCV‐HCC patients (P < .001 for both by the log‐rank test). HCC aetiology was not an independent predictor of survival, though ethnicity, cirrhosis status, meeting Milan criteria and treatment allocation were.

Conclusions

Compared with viral HCC patients, those with cryptogenic HCC had lower prevalence of cirrhosis, were diagnosed with larger tumours at more advanced stages of disease, and had poorer overall survival. Additional efforts are needed to identify patients at risk of cryptogenic HCC and to identify cryptogenic HCC at earlier stages of disease.
Kamenetsk—A new impact structure in the Ukrainian Shield
Authors: Gurov Eugene , Nikolaenko Nikolay , Shevchuk Helena , Yamnichenko Anatoly
Published: October 2017

The Kamenetsk impact structure is a deeply eroded simple crater that formed in crystalline rocks of the Ukrainian Shield. This study presents structural, lithologic, and shock metamorphic evidence for an impact origin of the Kamenetsk structure, which was previously described as a paleovolcano. The Kamenetsk structure is an oval depression that is 1.0–1.2 km in diameter and 130 m deep. The structure is deeply eroded, and only the lower part of the sequence of lithic breccia has been preserved in the deepest part of the crater to recent time, while the predominant part of impact rocks and postimpact sediments was eroded. Manifestations of shock metamorphism of minerals, especially planar deformation features in quartz and feldspars, were determined by petrographic investigations of lithic breccia that allowed us to determine the impact origin of the Kamenetsk structure. The erosion of the crater and surrounding target to a minimal depth of 220 m preceded the deposition of the postimpact sediments. The time of the formation of the Kamenetsk structure is bracketed within a wide interval from 2.0 to 2.1 Ga, the age of the crystalline target rocks, to the Late Miocene age of the sediments overlaying the crater. The deep erosion of the structure suggests it is probably Paleozoic in age.
Atom‐probe tomography and transmission electron microscopy of the kamacite–taenite interface in the fast‐cooled Bristol IVA iron meteorite
Authors: Rout Surya S. , Heck Philipp R. , Isheim Dieter , Stephan Thomas , Zaluzec Nestor J. , Miller Dean J. , Davis Andrew M. , Seidman David N.
Published: October 2017

We report the first combined atom‐probe tomography (APT) and transmission electron microscopy (TEM) study of a kamacite–tetrataenite (K–T) interface region within an iron meteorite, Bristol (IVA). Ten APT nanotips were prepared from the K–T interface with focused ion beam scanning electron microscopy (FIB‐SEM) and then studied using TEM followed by APT. Near the K‐T interface, we found 3.8 ± 0.5 wt% Ni in kamacite and 53.4 ± 0.5 wt% Ni in tetrataenite. High‐Ni precipitate regions of the cloudy zone (CZ) have 50.4 ± 0.8 wt% Ni. A region near the CZ and martensite interface has <10 nm sized Ni‐rich precipitates with 38.4 ± 0.7 wt% Ni present within a low‐Ni matrix having 25.5 ± 0.6 wt% Ni. We found that Cu is predominantly concentrated in tetrataenite, whereas Co, P, and Cr are concentrated in kamacite. Phosphorus is preferentially concentrated along the K‐T interface. This study is the first precise measurement of the phase composition at high spatial resolution and in 3‐D of the K‐T interface region in a IVA iron meteorite and furthers our knowledge of the phase composition changes in a fast‐cooled iron meteorite below 400 °C. We demonstrate that APT in conjunction with TEM is a useful approach to study the major, minor, and trace elemental composition of nanoscale features within fast‐cooled iron meteorites.
Sulfide–oxide assemblages in Acfer 094—Clues to nebular metal–gas interactions
Authors: Barth M. I. F. , Harries D. , Langenhorst F. , Hoppe P.
Published: October 2017

The ungrouped carbonaceous chondrite Acfer 094 is among the least altered samples of the early solar system. We have studied concentric sulfide–oxide aggregates from this meteorite by transmission electron microscopy (TEM) and nanoscale secondary ion mass spectrometry (NanoSIMS). The main minerals present are magnetite, pentlandite, and pyrrhotite/troilite. The outer parts of the aggregates include μm‐sized olivine and pyroxenes with variable Mg/Fe ratios. One aggregate contains taenite (56.7 wt% Ni) within its central part that is surrounded by pentlandite and magnetite. We conclude that both phases have formed by oxidation and sulfidization of metal and, based on the metal and sulfide Fe/Ni ratio, a (sulfide)‐formation temperature of 400–550 °C can be constrained. This temperature is higher than any temperature that could be expected to have occurred on the Acfer 094 parent body, and also textural evidence indicates that the aggregates formed before parent‐body accretion. We therefore conclude that the formation of the sulfide–oxide aggregates occurred most likely in the solar nebular at highly variable H2O and H2S fugacities. Oxygen‐isotopic compositions of magnetite within these assemblages show that they are indistinguishable from the meteorite's matrix (δ17OSMOW ≈ 4 ± 8‰, δ18OSMOW ≈ 10 ± 6‰, and ∆17OSMOW ≈ −1 ± 5‰). An enrichment of 17,18O relative to chondrules of Acfer 094 suggests a link between the formation of the sulfide–oxide aggregates and the preaccretionary processing of matrix grains in a volatile‐enriched nebular environment.
Social cognition: Concepts, neural basis and its role in multiple sclerosis
Authors: Labbé Tomás , Ciampi Ethel , Carcamo Rodríguez Claudia
Published: October 2017

Social cognition, including social perception, empathy and theory of mind, focuses on how people process, store, and apply information about other people and social situations, thus guiding social interactions. Specific patterns have been described in patients affected by different pathologies, such as Alzheimer's disease, autism and schizophrenia. Multiple sclerosis, an immune‐mediated neurodegenerative disease, can affect global cognition in 40–70% of patients, with an impact on work and family status. Multiple sclerosis patients have shown a decrease in performance of tasks related to social cognition, and reflect changes in the structure and activity of specific brain areas. In the present review, we propose an operational definition of social cognition and its subdomains, and a comprehensive overview of how social perception, empathy and theory of mind are decreased in multiple sclerosis patients. Finally, we discuss its relationship with neuropsychiatric disorders, and expose some questions that remain unanswered.
Quantitative proteomics of a B12‐dependent alga grown in coculture with bacteria reveals metabolic tradeoffs required for mutualism
Authors: Helliwell Katherine E. , Pandhal Jagroop , Cooper Matthew B. , Longworth Joseph , Kudahl Ulrich Johan , Russo David A. , Tomsett Eleanor V. , Bunbury Freddy , Salmon Deborah L. , Smirnoff Nicholas , Wright Phillip C. , Smith Alison G.
Published: October 2017

The unicellular green alga Lobomonas rostrata requires an external supply of vitamin B12 (cobalamin) for growth, which it can obtain in stable laboratory cultures from the soil bacterium Mesorhizobium loti in exchange for photosynthate. We investigated changes in protein expression in the alga that allow it to engage in this mutualism.

We used quantitative isobaric tagging (iTRAQ) proteomics to determine the L. rostrata proteome grown axenically with B12 supplementation or in coculture with M. loti. Data are available via ProteomeXchange (PXD005046).

Using the related Chlamydomonas reinhardtii as a reference genome, 588 algal proteins could be identified. Enzymes of amino acid biosynthesis were higher in coculture than in axenic culture, and this was reflected in increased amounts of total cellular protein and several free amino acids. A number of heat shock proteins were also elevated. Conversely, photosynthetic proteins and those of chloroplast protein synthesis were significantly lower in L. rostrata cells in coculture. These observations were confirmed by measurement of electron transfer rates in cells grown under the two conditions.

The results indicate that, despite the stability of the mutualism, L. rostrata experiences stress in coculture with M. loti, and must adjust its metabolism accordingly.
Homoeologous exchanges cause extensive dosage‐dependent gene expression changes in an allopolyploid crop
Authors: Lloyd Andrew , Blary Aurélien , Charif Delphine , Charpentier Catherine , Tran Joseph , Balzergue Sandrine , Delannoy Etienne , Rigaill Guillem , Jenczewski Eric
Published: October 2017

Structural variation is a major source of genetic diversity and an important substrate for selection. In allopolyploids, homoeologous exchanges (i.e. between the constituent subgenomes) are a very frequent type of structural variant. However, their direct impact on gene content and gene expression had not been determined.

Here, we used a tissue‐specific mRNA‐Seq dataset to measure the consequences of homoeologous exchanges (HE) on gene expression in Brassica napus, a representative allotetraploid crop.

We demonstrate that expression changes are proportional to the change in gene copy number triggered by the HEs. Thus, when homoeologous gene pairs have unbalanced transcriptional contributions before the HE, duplication of one copy does not accurately compensate for loss of the other and combined homoeologue expression also changes. These effects are, however, mitigated over time.

This study sheds light on the origins, timing and functional consequences of homeologous exchanges in allopolyploids. It demonstrates that the interplay between new structural variation and the resulting impacts on gene expression, influences allopolyploid genome evolution.
Arbuscular mycorrhizal fungi promote coexistence and niche divergence of sympatric palm species on a remote oceanic island
Authors: Osborne Owen G. , De‐Kayne Rishi , Bidartondo Martin I. , Hutton Ian , Baker William J. , Turnbull Colin G. N. , Savolainen Vincent
Published: October 2017

Microbes can have profound effects on their hosts, driving natural selection, promoting speciation and determining species distributions. However, soil‐dwelling microbes are rarely investigated as drivers of evolutionary change in plants.

We used metabarcoding and experimental manipulation of soil microbiomes to investigate the impact of soil and root microbes in a well‐known case of sympatric speciation, the Howea palms of Lord Howe Island (Australia). Whereas H. forsteriana can grow on both calcareous and volcanic soils, H. belmoreana is restricted to, but more successful on, volcanic soil, indicating a trade‐off in adaptation to the two soil types.

We suggest a novel explanation for this trade‐off. Arbuscular mycorrhizal fungi (AMF) are significantly depleted in H. forsteriana on volcanic soil, relative to both H. belmoreana on volcanic soil and H. forsteriana on calcareous soil. This is mirrored by the results of survival experiments, where the sterilization of natural soil reduces Howea fitness in every soil–species combination except H. forsteriana on volcanic soil. Furthermore, AMF‐associated genes exhibit evidence of divergent selection between Howea species.

These results show a mechanism by which divergent adaptation can have knock‐on effects on host–microbe interactions, thereby reducing interspecific competition and promoting the coexistence of plant sister species.
Autonomy and managerial reforms in Europe: Let or make public managers manage?
Authors: Bezes Philippe , Jeannot Gilles
Published: October 2017

Drawing on a survey of top executives in central governments in 11 European countries (N = 5,190), this study explores variations in the extent and scale of managerial autonomy across and within European states. The article is based on a comparative, multidimensional and relational approach to autonomy. Confirming predictions of qualitative studies, it shows that these variations can partly be explained by the intensity of New Public Management (NPM) reforms and provides a typology of European countries connecting the intensity of neo‐managerial reforms (measured by the declared use of management tools) to the degree of managerial autonomy. Our findings support Donald Kettl's hypothesis differentiating countries where the ‘let the manager manage’ model prevails, as in the Northern countries, by contrast with those, such as the United Kingdom, dominated by the ‘make the manager manage’ programme. The promise of managerial autonomy has also not been delivered to the same extent across and within countries.
Improving success of rare plant seed reintroductions: a case study of Dalea carthagenensis var. floridana, a rare legume with dormant seeds
Authors: Maschinski Joyce , Possley Jennifer , Walters Christina , Hill Lisa , Krueger Lisa , Hazelton Dallas
Published: October 2017

Recent reviews of rare plant reintroduction success indicate that far fewer studies have been conducted with seeds than whole plants, and of these, less than 10% have established or had long‐term population persistence reported. Because seed reintroductions are relatively less expensive than plant reintroductions, determining ways to increase efficacy of using seeds to establish rare populations has conservation benefits. In laboratory trials, we examined seed germination of an endangered legume, Dalea carthagenensis var. floridana, endemic in South Florida, U.S.A. Laboratory treatments confirmed that seeds are hard seeded, remaining viable for 1,452 days even when moist; nicking, heat, and freezing triggered higher and more rapid germination than controls. Field trials begun in 2009, using pretreated (frozen) and untreated seeds within two habitats (natural and novel) revealed that freezing pretreatment increased germination in both habitats. However, plants matured, reproduced, and established seedlings only in natural habitat, not in novel habitat. By 2012, seed treatment plots in natural pine rockland had significantly greater numbers of reproductive plants and seedlings than controls. In a restoration context, using seed pretreatments to stimulate germination can improve establishment success in suitable habitats. When paired with essential vegetation management and a controlled burn, seed augmentation helped rescue the population from the brink of extinction.
A Behavior‐Based Approach to the Estimation of Poverty in India
Authors: Almås Ingvild , Kjelsrud Anders , Somanathan Rohini
Published: October 2017

Estimates of poverty in India are crucial inputs for the understanding of world poverty, yet there is much disagreement about the numbers and the legitimacy of methods used to derive them. In this paper, we propose and justify an alternative approach to identify the poor, which uses the proportion of income spent on food. Our estimates have weaker data requirements than official methods, and they compare favorably with several validation tests. Most notably, households around our state poverty lines obtain their calories from similar sources, whereas this is not true of official poverty lines. We also find that rates of self‐reported hunger are higher in states that we classify as poor.
Recruitment of 7SL RNA to assembling HIV‐1 virus‐like particles
Authors: Itano Michelle S. , Arnion Helene , Wolin Sandra L. , Simon Sanford M.
Published: October 2017

Retroviruses incorporate specific host cell RNAs into virions. In particular, the host noncoding 7SL RNA is highly abundant in all examined retroviruses compared with its cellular levels or relative to common mRNAs such as actin. Using live cell imaging techniques, we have determined that the 7SL RNA does not arrive with the HIV‐1 RNA genome. Instead, it is recruited contemporaneously with assembly of the protein HIV‐1 Gag at the plasma membrane. Further, we demonstrate that complexes of 7SL RNA and Gag can be immunoprecipitated from both cytosolic and plasma membrane fractions. This indicates that 7SL RNAs likely interact with Gag prior to high‐order Gag multimerization at the plasma membrane. Thus, the interactions between Gag and the host RNA 7SL occur independent of the interactions between Gag and the host endosomal sorting complex required for transport (ESCRT) proteins, which are recruited temporarily at late stages of assembly. The interactions of 7SL and Gag are also independent of interactions of Gag and the HIV‐1 genome which are seen on the plasma membrane prior to assembly of Gag.
Incidence and risk factors of surgical site infection and septic arthritis after elective arthroscopy in horses
Authors: Brunsting Julie Y. , Pille Frederik J. , Oosterlinck Maarten , Haspeslagh Maarten , Wilderjans Hans C.
Published: October 2017

Objective

To determine the incidence of infection and associated risk factors, after elective arthroscopy.

Study design

Retrospective case study.

Animals

Horses (n=1079) undergoing elective arthroscopy.

Methods

Medical records of all horses that underwent elective arthroscopy between 2006 and 2013 were reviewed. Age, gender, breed, surgeon, number of joints operated, total anesthetic time, perioperative antimicrobial administration, and the presence and size of osteochondral fragments/subchondral lesions were recorded. For each operated joint, the development of postoperative infection (surgical site infection [SSI] and/or septic arthritis) and long‐term outcome (>6 months) were recorded. Multivariate logistic regression was used to test for association between the independent variables and the dependent outcomes.

Results

A total of 1741 joints in 1079 horses underwent arthroscopy. SSI without septic arthritis occurred in 1 fetlock joint (0.14%), 1 tibiotarsal joint (0.19%), and 6 femoropatellar joints (1.67%). Thirteen joints (0.75%) were diagnosed with septic arthritis, including 1 fetlock joint (0.14%), 4 tibiotarsal joints (0.74%), and 8 femoropatellar joints (2.23%). The probability of postoperative SSI was higher when large lesions (>40 mm long) were treated, compared to medium (20‐40 mm, P = .005) and small (<20 mm, P < .001) lesions. SSI was a significant risk factor for the development of septic arthritis (P < .001). Although age did not affect the incidence of SSI, increasing age was associated with a lower rate of septic arthritis rate (P = .028).

Conclusion

Septic arthritis after elective arthroscopy was more likely in the presence of SSI and younger age. Horses with large lesions were at risk for SSI, which translated into a higher incidence of postoperative septic arthritis after femoropatellar arthroscopy.
The Effects of Performing Prayer on the Physical Fitness Levels of Men Over 60 Years Old
Authors: Yüksek Selami
Published: October 2017

This study was carried out to determine and compare the physical fitness levels of elderly people who pray regularly with those who lead a sedentary lifestyle, as well as to emphasize the importance of performing regular prayer for the physical fitness levels of elderly people.The research sample consisted of 849 men who were able to conduct their daily activities independently, with no serious health problems, and who were viewed as healthy according to their age category. They were divided on the basis of age into 5 age groups. The Senior Fitness Test (SFT) was applied to determine the physical fitness levels of elderly men (Rikli & Jones, 2001). In addition, a questionnaire was administered to learn whether the subjects performed regular prayer or not.The differences between the prayer group and sedentary group were analyzed using the Independent Samples Test. It was found that the physical fitness levels of the elderly men who performed prayer were higher than those of the sedentary group; all of the parameters of physical fitness measured through the SFT protocol were higher in the case of the elderly men who performed prayer.
Carotid chemoreceptor control of muscle sympathetic nerve activity in hypobaric hypoxia
Authors: Fisher James P. , Flück Daniela , Hilty Matthias P. , Lundby Carsten
Published: October 2017

New Findings

What is the central question of this study?

High‐altitude hypoxia increases muscle sympathetic nerve activity (MSNA), but whether intravenous infusion of dopamine, to blunt the responsiveness of the carotid chemoreceptors, reduces MSNA at high altitude is not known.

What is the main finding and its importance?

Muscle sympathetic nerve activity was elevated after 15–17 days of high‐altitude hypoxia (3454 m) compared with values at ‘sea level’ (432 m). However, intravenous dopamine infusion to blunt the responsiveness of the carotid chemoreceptors did not significantly decrease MSNA either at sea level or at high altitude, suggesting that high‐altitude sympathoexcitation arises via a different mechanism.

High‐altitude hypoxia causes pronounced sympathoexcitation, but the underlying mechanisms remain unclear. We tested the hypothesis that i.v. infusion of dopamine to attenuate carotid chemoreceptor responsiveness would reduce muscle sympathetic nerve activity (MSNA) at high altitude. Nine healthy individuals [mean (SD); 26 (4) years of age] were studied at ‘sea level’ (SL; Zurich) and at high altitude (ALT; 3454 m; 15–17 days after arrival), both while breathing the ambient air and during an acute incremental hypoxia test (eight 3 min stages; partial pressure of end‐tidal O2 90–45 mmHg). Intravenous infusions of dopamine (3 μg kg−1 min−1) and placebo (saline) were administered on both study days, according to a single‐blind randomized cross‐over design. Sojourn to high altitude decreased the partial pressure of end‐tidal O2 (to ∼60 mmHg) and increased minute ventilation [; mean ± SEM, SL versus ALT: saline, 8.6 ± 0.5 versus 11.3 ± 0.6 l min−1; dopamine, 8.2 ± 0.5 versus 10.6 ± 0.8 l min−1; P < 0.05] and MSNA burst frequency by ∼80% [SL versus ALT: saline, 16 ± 3 versus 28 ± 4 bursts min−1; dopamine, 16 ± 4 versus 31 ± 4 bursts min−1; P < 0.05) when breathing the ambient air, but were not different with dopamine. Increases in MSNA burst frequency and during the acute incremental hypoxia test were greater at ALT than SL (P < 0.05). Dopamine did not affect the magnitude of the MSNA burst frequency response to acute incremental hypoxia at either SL or ALT. However, was lower with dopamine than saline administration throughout the acute incremental hypoxia test at ALT. These data indicate that i.v. infusion of low‐dose dopamine to blunt the responsiveness of the carotid chemoreceptors does not significantly decrease MSNA at high altitude.
Thermo-Elastic Model of Epicenter Displacement by Laser Pulse Irradiated on Metallic Surfaces
Authors: Truong Thanh Chung , Abetew Ayalsew Dagnew , Lee Jung-Ryul , Ihn Jeong-Beom
Published: October 2017

In recent years, there is a much interest in developing of nondestructive testing (NDT) systems using the pulse-echo laser ultrasonics. The key idea is to combine a low-power and short-pulsewidth laser excitation with a continuous sensing laser; and use a scanning mechanism, such as five degrees-of-freedom (5DOF)-axis robot, laser mirror scanner, or motorized linear translation or rotation scanner stage, to scan the combined beam on the structure. In order to optimize the parameters of the excitation laser, a realistic theoretical model of the epicenter displacement in thermo-elastic regime is needed. This paper revisits and revises the study of Spicer and Hurley (1996, “Epicentral and Near Epicenter Surface Displacements on Pulsed Laser Irradiated Metallic Surfaces,” Appl. Phys. Lett., 68(25), pp. 3561–3563) on thermo-elastic model of epicenter displacement with two new contributions: first, we revised Spicer’s model to take into account the optical penetration effect, which was neglected in Spicer’s model; and second, the revised model was used to investigate the effect of laser rise time and beam size to the epicenter displacement. We showed that a pulse laser with short rise time generates an equivalent surface displacement with a pulse laser with long rise time, except a “spike” at the beginning of the epicenter waveform; also when the laser beam size increases, the epicenter displacement decreases. These two conclusions were then validated by experiments.
Redescription of Belba paracorynopus Bulanova-Zachvatkina, 1962 (Acarina: Oribatida: Damaeidae) from Georgia
Authors: Miko Ladislav , Kolesnikov Vasiliy B. , Murvanidze Maka
Published: October 2017

Belba paracorynopus Bulanova-Zachvatkina, 1962 is redescribed on the basis of new material collected in Georgia and damaged paratypes of Bulanova-Zachvatkina. The species belongs to the Belba corynopus group and differs from other species of the group by the size and form of notogastral setae, formation of the prodorsum and detailed chaetotaxy of legs. Variability of certain traits and differences to the original description and material are discussed, as well as the relation to other species of this group. The finding in Georgia extends the known area of distribution from Far East and China to the west.
Deposition of Mo/Si multilayers onto MEMS micromirrors and its utilization for extreme ultraviolet maskless lithography
Authors: Chkhalo Nikolay , Polkovnikov Vladimir , Salashchenko Nikolay , Toropov Mikhail
Published: October 2017

The paper deals with the problems of the deposition of multilayer Mo/Si mirrors (MLMs), reflecting in the extreme ultraviolet (EUV) spectral range, onto microelectromechanical system (MEMS). Such MEMS micromirrors can be used to control beams of EUV and soft x-ray radiation, in particular, as spatial modulators of the radiation flux (dynamic masks) for maskless EUV lithography (EUVL). The requirements of the surfaces of such micromirrors for use in MEMS for maskless EUVL are analyzed. Experimental results on the roughness and the surface shapes of micromirrors commercially available MEMS with a pixel size of 8 × 8 μm are presented. The reflection coefficients of the Mo/Si MLMs and the distortions of the shapes of the micromirrors due to internal stresses in the films are studied. The reflection coefficient of Mo/Si MLMs, containing a proportion of molybdenum in the period, optimized for maximum reflection coefficient at a wavelength of 13.5 nm, was about 3%. Samples with stress-compensating Cr/Sc under-layers have overall reflection coefficients up to 36%; taking into account the losses associated with the gaps and topology of the micromirrors, the reflection coefficient was 43%. This result indicates the real possibility of creating dynamic masks based on commercially available MEMS micromirrors for maskless EUVL.
The Hunt for Red October II: A magnetohydrodynamic boat demonstration for introductory physics
Authors: Overduin James , Polyak Viktor , Rutah Anjalee , Sebastian Thomas , Selway Jim , Zile Daniel
Published: October 2017

The 1990 film “The Hunt for Red October” (based on Tom Clancy’s 1984 debut novel of the same name) featured actors like Sean Connery and Alec Baldwin, but the star of the movie for physicists was a revolutionary new magnetohydrodynamic (MHD) marine propulsion system. The so-called “caterpillar drive” worked with no moving parts, allowing a nuclear missile-armed Soviet submarine to approach the U.S. coast undetected. As the submarine captain (played by Connery) said, “Once the world trembled at the sound of our rockets … now they will tremble again—at the sound of our silence.
Simple Pencil-and-Paper Notation for Representing Electrical Charge States
Authors: Morse Robert A.
Published: October 2017

In Benjamin Franklin’s one fluid theory of electrification, ordinary unelectrified matter consisted of a matrix of matter suffused with a certain amount of “electrical fluid.” Electrical effects were due to an excess or deficit of electrical fluid, hence the terms positive and negative. Before the development of a modern view of the atom, diagrams showing charged objects would simply have “+” or “–” signs to indicate the charged state. As physicists we know how to interpret these diagrams and understand what they are telling us about the underlying atomic model of charging. However, novice students may not readily make the connection between the atomic model, in which a charged solid object either gains or loses electrons but does not gain or lose positive charges. Furthermore, when isolated objects become charged, the total number of electrons must be accounted for as charge is a conserved quantity. To really understand the changes that occur in charging by contact, conduction, or induction, it is useful for students to visually represent the processes in a way that emphasizes the atomicity of the processes, including the induced polarization of objects, and the requirement that charge be conserved.
Let’s Catch a (Heat) Wave
Authors: Herman Rhett , Ballowe Abigail , Ashley Joe
Published: October 2017

Two students in a recent thermodynamics/statistical mechanics course needed to complete a course-related project to receive honors credit for the class. Such courses are typically theoretical, without an accompanying laboratory, although there are existing related hands-on exercises. The choice of the project was influenced by one student’s desire to become a mechanical engineer after graduating while the other wanted a project that was “fun” without “just doing more calculations.” The choice of this particular project was further refined by the future engineer’s interest in the thermodynamics of car engines.
Modified error in constitutive equations (MECE) approach for ultrasound elastography
Authors: Ghosh Susanta , Zou Zilong , Babaniyi Olalekan , Aquino Wilkins , Diaz Manuel I. , Bayat Mahdi , Fatemi Mostafa
Published: October 2017

A partial differential equation-constrained optimization approach is presented for reconstructing mechanical properties (e.g., elastic moduli). The proposed method is based on the minimization of an error in constitutive equations functional augmented with a least squares data misfit term referred to as MECE for “modified error in constitutive equations.” The main theme of this paper is to demonstrate several key strengths of the proposed method on experimental data. In addition, some illustrative examples are provided where the proposed method is compared with a common shear wave elastography (SWE) approach. To this end, both synthetic data, generated with transient finite element simulations, as well as ultrasonically tracked displacement data from an acoustic radiation force (ARF) experiment are used in a standard elasticity phantom. The results indicate that the MECE approach can produce accurate shear modulus reconstructions with significantly less bias than SWE.
Load Monitoring Variables in Training and Competition Situations: A Systematic Review Applied to Wheelchair Sports
Authors: Simim Mário A.M. , de Mello Marco Túlio , Silva Bruno V.C. , Rodrigues Dayane F. , Rosa João Paulo P. , Couto Bruno Pena , da Silva Andressa
Published: October 2017

The aim of this review was to identify the main variables for load monitoring in training and competition situations in wheelchair sports. Studies were identified from a systematic search of three databases (PubMed, Web of Science, and SportDiscuss), with search phrases constructed from MeSH terms, alone or in combination, limited to English-language literature, and published up to January 2016. Our main findings were that variables related to external load (distance, speed, and duration) are used to monitor load in competition. In training situations, researchers have used variables related to internal load (heart rate and VO2); in both training and competition situations, researchers used internal load measurements (training impulse and ratings of perceived exertion). We conclude that the main variables for load monitoring in competitive situations were distance, speed, and duration, whereas the variables for training situations were heart rate, VO2, training impulse, and ratings of perceived exertion.
Effect of Preexercise Ingestion of Modified Amylomaize Starch on Glycemic Response While Cycling
Authors: Parks Rachel B. , Angus Hector F. , King Douglas S. , Sharp Rick L.
Published: October 2017

Amylomaize-7 is classified as a resistant corn starch and is 68% digestible. When modified by partial hydrolysis in ethanol and hydrochloric acid its digestibility is 92%, yet retains its low glycemic and insulinemic properties. The purpose of this study was to characterize the metabolic response when modified amylomaize-7 or dextrose is consumed in the hour before exercise, and to compare the effect on performance of a brief high-intensity cycling trial. Ten male, trained cyclists were given 1 g/kg body mass of dextrose (DEX) or modified amylomaize-7 (AMY-7) or a flavored water placebo (PL) 45 min prior to exercise on a cycle ergometer. A 15-min ride at 60% Wmax was immediately followed by a self-paced time trial (TT) equivalent to 15 min at 80% Wmax. When cyclists consumed DEX, mean serum glucose concentration increased by 3.3 ± 2.1 mmol/L before exercise, compared to stable serum glucose observed for AMY-7 or PL. Glucose concentrations returned to baseline by pre-TT in all treatments. However, the mean post-TT glucose concentration of the DEX group was significantly lower than baseline, AMY-7, or PL. Serum insulin concentration increased nine-fold from baseline to preexercise in the DEX trial, whereas PL or AMY-7 remained unchanged. Time required to complete the performance trial was not significantly different between DEX, AMY-7 or PL. Preexercise ingestion of modified amylomaize-7 compared to dextrose resulted in a more stable serum glucose concentration, but did not offer a performance advantage in this high-intensity cycling trial.
External Match Loads of Footballers With Cerebral Palsy: A Comparison Among Sport Classes
Authors: Yanci Javier , Castillo Daniel , Iturricastillo Aitor , Urbán Tomás , Reina Raúl
Published: October 2017

Purpose:To determine and compare the external match load, according to sport class (FT), of footballers with cerebral palsy (CP) during the International Federation of CP Football World Championships Qualification Tournament.Methods:Forty-two international male footballers with CP participated in the data collection. The footballers with CP were classified according to their FT into 3 groups (ie, FT5/6, FT7, and FT8). External match load (ie, total distance covered, distance covered at different speeds, accelerations, decelerations, player load, peak metabolic power, and changes of directions) was collected for both halves during official matches with global positioning system devices.Results:Players with lower impairment (FT8) covered more distance (effect size = 0.30–0.60) at high-intensity running (13.0–18.0 km·h−1) and sprinting (>18.0 km·h−1) and performed more (effect size = 0.29–1.08) accelerations, decelerations, and changes of direction at high intensity in matches than did other players (ie, FT5/6 and FT7 groups).Conclusion:Because high-intensity actions are relevant to football performance and there are differences caused by players’ impairments, the International Federation of CP Football classification protocols should include high-intensity actions during the technical assessment as part of the procedures for determining the sport class of football players with CP.
Effect of Intensified Endurance Training on Pacing and Performance in 4000-m Cycling Time Trials
Authors: Wallett Alice M. , Woods Amy L. , Versey Nathan , Garvican-Lewis Laura A. , Welvaert Marijke , Thompson Kevin G.
Published: October 2017

Studies examining pacing strategies during 4000-m cycling time trials (TTs) typically ensure that participants are not prefatigued; however, competitive cyclists often undertake TTs when already fatigued. This study aimed to determine how TT pacing strategies and sprint characteristics of cyclists change during an intensified training period (mesocycle). Thirteen cyclists regularly competing in A- and B-grade cycling races and consistently training (>10 h/wk for 4 [1] y) completed a 6-wk training mesocycle. Participants undertook individually prescribed training, using training stress scores (TrainingPeaks, Boulder, CO), partitioned into a baseline week, a build week, 2 loading weeks (designed to elicit an overreached state), and 2 recovery weeks. Laboratory-based tests (15-s sprint and TT) and Recovery-Stress Questionnaire (RESTQ-52) responses were repeatedly undertaken over the mesocycle. TT power output increased during recovery compared with baseline and loading weeks (P = .001) with >6-W increases in mean power output (MPO) detected for 400-m sections (10% bins) from 1200 to 4000 m in recovery weeks. Decreases in peak heart rate (P < .001) during loading weeks and postexercise blood lactate (P = .005) during loading week 2 and recovery week 1 were detected. Compared with baseline, 15-s sprint MPO declined during loading and recovery weeks (P < .001). An interaction was observed between RESTQ-52 total stress score with a 15-s sprint (P = .003) and with a TT MPO (P = .04), indicating that participants who experienced greater stress during loading weeks exhibited reduced performance. To conclude, intensified endurance training diminished sprint performance but improved 4000-m TT performance, with a subtle change in MPO evident over the last 70% of TTs.
The Association of Sitting Time With Sarcopenia Status and Physical Performance at Baseline and 18-Month Follow-Up in the Residential Aged Care Setting
Authors: Reid Natasha , Keogh Justin W. , Swinton Paul , Gardiner Paul A. , Henwood Timothy R.
Published: October 2017

This study investigated the association of sitting time with sarcopenia and physical performance in residential aged care residents at baseline and 18-month follow-up. Measures included the International Physical Activity Questionnaire (sitting time), European Working Group definition of sarcopenia, and the short physical performance battery (physical performance). Logistic regression and linear regression analyses were used to investigate associations. For each hour of sitting, the unadjusted odds ratio of sarcopenia was 1.16 (95% confidence interval [0.98, 1.37]). Linear regression showed that each hour of sitting was significantly associated with a 0.2-unit lower score for performance. Associations of baseline sitting with follow-up sarcopenia status and performance were nonsignificant. Cross-sectionally, increased sitting time in residential aged care may be detrimentally associated with sarcopenia and physical performance. Based on current reablement models of care, future studies should investigate if reducing sedentary time improves performance among adults in end of life care.