bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vitro Comparison of Two Neonatal ECMO Circuits Using a Roller or Centrifugal Pump With Three Different In‐Line Hemoconcentrators for Maintaining Hemodynamic Energy Delivery to the Patient
Authors: Force Madison , Moroi Morgan , Wang Shigang , Palanzo David A. , Kunselman Allen R. , Ündar Akif
Published: January 2018

The objective of this study was to compare three different hemoconcentrators (Hemocor HPH 400, Mini, and Junior) with two different neonatal ECMO circuits using a roller or a centrifugal pump at different pseudo‐patient pressures and flow rates in terms of hemodynamic properties. This evidence‐based research is necessary to optimize the ECMO circuitry for neonates. The circuits used a 300‐mL soft‐shell reservoir as a pseudo‐patient approximating the blood volume of a 3 kg neonate, two blood pumps, and a Quadrox‐iD Pediatric oxygenator with three different in‐line hemoconcentrators (Hemocor HPH 400, Mini, and Junior). One circuit used a Maquet H20 roller pump and another circuit used a Maquet RotaFlow centrifugal pump. The circuit was primed with lactated Ringer's solution followed by heparinized packed red blood cells with a hematocrit of 40%. The pseudo‐patient's pressure was manually maintained at 40, 60, or 80 mm Hg and the flow rate was maintained at 200, 400, or 600 mL/min with a circuit temperature of 36°C. Pressure and flow data was recorded using a custom‐made data acquisition device. Mean pressures, diverted blood flow, pressure drops, and total hemodynamic energy (THE) were calculated for each experimental condition. The roller pump and centrifugal pump performed similarly for all hemodynamic properties with all experimental conditions. The Hemocor HPH Junior hemoconcentrator added the highest resistance to the circuit. The Hemocor HPH Junior provided the highest circuit pressures, lowest diverted blood flow, highest pressure drop across the circuit, and highest THE generated by the pump. The Hemocor HPH 400 added the least resistance to the circuit, providing the lowest circuit pressures, more diverted flow, lowest pressure drop, and the lowest THE generated by the pump. However, the THE delivered to the patient was the same for the three hemoconcentrators. While the three hemoconcentrators performed differently in terms of hemodynamic properties throughout the circuit, the THE transmitted to the patient was similar for all three hemoconcentrators due to the consistent pseudo‐patient's pressure that was manually maintained for each trial. While the THE delivered to the patient indicates similar perfusion for these patients with any of the three hemoconcentrators, the differences in added resistance to the circuit may impact the decision of which hemoconcentrator is used. There was no clinically significant difference between the two circuits with the roller versus centrifugal pump in terms of hemodynamic properties in this study. Further in vivo research is warranted to confirm our findings.
PREVIEW (Prevention of Diabetes Through Lifestyle Intervention and Population Studies in Europe and Around the World) study in children aged 10 to 17 years: Design, methods and baseline results
Authors: Dorenbos Elke , Drummen Mathijs , Rijks Jesse , Adam Tanja , Stouthart Pauline , Alfredo Martínez J. , Navas‐Carretero Santiago , Stratton Gareth , Swindell Nils , Fogelholm Mikael , Raben Anne , Westerterp‐Plantenga Margriet , Vreugdenhil Anita
Published: January 2018

Insulin resistance (IR) in adolescence is associated with type 2 diabetes mellitus [T2DM]. The PREVIEW (Prevention of Diabetes Through Lifestyle Intervention and Population Studies in Europe and Around the World) study assessed the effectiveness of a high‐protein, low‐glycaemic‐index diet and a moderate‐protein, moderate‐glycaemic‐index diet to decrease IR in insulin‐resistant children who were overweight or obese. Inclusion criteria were age 10 to 17 years, homeostatic model assessment of IR (HOMA‐IR) ≥2.0 and overweight/obesity. In 126 children (mean ± SD age 13.6 ± 2.2 years, body mass index [BMI] z‐score 3.04 ± 0.66, HOMA‐IR 3.48 ± 2.28) anthropometrics, fat mass percentage (FM%), metabolic characteristics, physical activity, food intake and sleep were measured. Baseline characteristics did not differ between the groups. IR was higher in pubertal children with morbid obesity than in prepubertal children with morbid obesity (5.41 ± 1.86 vs 3.23 ± 1.86; P = .007) and prepubertal and pubertal children with overweight/obesity (vs 3.61 ± 1.60, P = .004, and vs 3.40 ± 1.50, P < .001, respectively). IR was associated with sex, Tanner stage, BMI z‐score and FM%. Fasting glucose concentrations were negatively associated with Baecke sport score (r = −0.223, P = .025) and positively with daytime sleepiness (r = 0.280, P = .016) independent of sex, Tanner stage, BMI z‐score and FM%. In conclusion, IR was most severe in pubertal children with morbid obesity. The associations between fasting glucose concentration and Baecke sport score and sleepiness suggest these might be possible targets for diabetes prevention.
DECLARE‐TIMI 58: Participants’ baseline characteristics
Authors: Raz Itamar , Mosenzon Ofri , Bonaca Marc P. , Cahn Avivit , Kato Eri T. , Silverman Michael G. , Bhatt Deepak L. , Leiter Lawrence A. , McGuire Darren K. , Wilding John P. H. , Gause‐Nilsson Ingrid A. M. , Langkilde Anna M. , Johansson Peter A. , Sabatine Marc S. , Wiviott Stephen D.
Published: January 2018

Aim

To describe the baseline characteristics of participants randomized in the Dapagliflozin Effect on CardiovascuLAR Events (DECLARE‐TIMI 58) trial, the pivotal study conducted to assess cardiovascular (CV) outcomes with dapagliflozin.

Methods

The DECLARE‐TIMI 58 trial will analyse 17 160 patients with type 2 diabetes randomized to treatment with dapagliflozin (10 mg/d) or matching placebo. We analysed their baseline characteristics.

Results

The participants’ mean ± SD age was 63.8 ± 6.8 years, 62.6% were male, and their mean ± SD diabetes duration was 11.8 ± 7.8 years, glycated haemoglobin 8.3% ± 1.2% (67 mmol/mol ± 9.7 mmol/mol) and body mass index 32.1 ± 6.0 kg/m2. Randomization included 6971 (40.6%) patients with atherosclerotic CV disease (CVD), and 10 189 (59.4%) patients with multiple risk factors (MRF) for CVD (defined as men age ≥ 55 years or women ≥60 years, with at least one of dyslipidaemia, hypertension or smoking). Patients with CVD compared with patients with MRF were younger (62.5 ± 8.1 vs 64.7 ± 5.6 years), more frequently male (72.1% vs 56.1%), less often used metformin (74.6% vs 81.2%), more often used insulin (44.2% vs 36.4%), and more frequently used statins, aspirin, clopidogrel and β‐blockers (82.2%, 71.1%, 24.7% and 66.6% vs 63.7%, 39.1%, 1.5% and 32.3%, respectively).

Conclusion

The DECLARE‐TIMI 58 trial is expected to provide conclusive data on the effect of treatment with dapagliflozin in addition to standard of care, on CV outcomes in a broad patient population with type 2 diabetes and CVD or MRF for CVD.
Safety and efficacy of once‐weekly semaglutide vs additional oral antidiabetic drugs in Japanese people with inadequately controlled type 2 diabetes: A randomized trial
Authors: Kaku Kohei , Yamada Yuichiro , Watada Hirotaka , Abiko Atsuko , Nishida Tomoyuki , Zacho Jeppe , Kiyosue Arihiro
Published: January 2018

Aim

To evaluate the safety and efficacy of once‐weekly subcutaneous semaglutide as monotherapy or combined with an oral antidiabetic drug (OAD) vs an additional OAD added to background therapy in Japanese people with type 2 diabetes (T2D) inadequately controlled on diet/exercise or OAD monotherapy.

Methods

In this phase III, open‐label trial, adults with T2D were randomized 2:2:1 to semaglutide 0.5 mg or 1.0 mg, or one additional OAD (a dipeptidyl peptidase‐4 inhibitor, biguanide, sulphonylurea, glinide, α‐glucosidase inhibitor or thiazolidinedione) with a different mode of action from that of background therapy. The primary endpoint was number of adverse events (AEs) after 56 weeks.

Results

Baseline characteristics were balanced between treatment arms (601 randomized). More AEs were reported in the semaglutide 0.5 mg (86.2%) and 1.0 mg (88.0%) groups than in the additional OAD group (71.7%). These were typically mild/moderate. Gastrointestinal AEs were most frequent with semaglutide, which diminished over time. The mean glycated haemoglobin (HbA1c) concentration (baseline 8.1%) was significantly reduced with semaglutide 0.5 mg and 1.0 mg vs additional OAD (1.7% and 2.0% vs 0.7%, respectively; estimated treatment difference [ETD] vs additional OAD −1.08% and −1.37%, both P < .0001). Body weight (baseline 71.5 kg) was reduced by 1.4 kg and 3.2 kg with semaglutide 0.5 mg and 1.0 mg, vs a 0.4‐kg increase with additional OAD (ETD −1.84 kg and −3.59 kg; both P < .0001). For semaglutide‐treated participants, >80% achieved an HbA1c concentration <7.0% (Japanese Diabetes Society target).

Conclusions

Semaglutide was well tolerated, with no new safety issues identified. Semaglutide treatment significantly reduced HbA1c and body weight vs additional OAD treatment in Japanese people with T2D.
The dancing thrombus: 4D transesophageal echocardiography in the diagnosis of a pedunculated left atrial appendage thrombus
Authors: Kelly Faith R. , Dire Christopher , Gore Rosco S.
Published: January 2018

It is rare that a left atrial appendage thrombus will grow to the extent that it can prolapse into the left ventricle. We report the case of a large prolapsing left atrial thrombus diagnosed by 3D echocardiography in a patient presenting with a transient ischemic attack.
Congenital aortocaval fistula between right aortic sinus of Valsalva and superior vena cava: A rare case report
Authors: Dabirian Mozhdeh , Ghaemian Ali , Nabati Maryam , Golshani Samad , Shokri Mojtaba
Published: January 2018

Thoracic aortocaval fistula is a very rare cause of left to right shunt. Drainage of fistula into the superior vena cava (SVC) is very uncommon. Clinical symptoms depend on the size of the shunt. We report a rare case of an asymptomatic 27‐year‐old woman with congenital aortocaval fistula to the SVC with a small amount of left to right shunt that was considered for serial medical follow‐up.
Comprehensive intraoperative transesophageal echocardiography of anomalous left coronary artery from pulmonary artery: What to look for and where to look?
Authors: Chigurupati Keerthi , Sukesan Subin , Lovhale Pravin S. , Dharan Baiju S. , Koshy Thomas
Published: January 2018

Anomalous origin of left coronary artery from pulmonary artery (ALCAPA) accounts for 0.4% of the congenital heart diseases. Comprehensive 2D and 3D transesophageal echocardiographic imaging of a well‐collateralized subset of ALCAPA is described. A nonstandard short‐axis view of both aorta and pulmonary arteries showed the origin of left coronary artery from the posterior sinus of the pulmonary artery and right coronary artery in its usual position. Pulse‐wave interrogation of the coronary arteries showed the direction of flow in opposite directions. Using the real time‐3D, the en‐face views of the origins of both coronaries were also demonstrated.
Treating hepatic encephalopathy in cirrhotic patients admitted to ICU with sodium phenylbutyrate: a preliminary study
Authors: Weiss Nicolas , Tripon Simona , Lodey Marion , Guiller Elsa , Junot Helga , Monneret Denis , Mayaux Julien , Brisson Hélène , Mallet Maxime , Rudler Marika , Imbert‐Bismut Françoise , Thabut Dominique ,   the Brain‐Liver Pitié‐Salpêtrière Study Group (BLIPS)
Published: January 2018

Hepatic encephalopathy (HE) influences short‐term and long‐term prognoses. Recently, glycerol phenylbutyrate (PB), that lowers ammonia by providing an alternate pathway to urea for waste nitrogen excretion, has shown that it was effective in preventing the occurrence of HE in RCT. The aim was to assess the benefits of sodium PB in cirrhotic patients admitted to ICU for overt HE, in terms of ammonia levels decrease, neurological improvement, and survival. Cirrhotic patients who presented with overt HE, ammonia levels >100 μmol/L, and did not display any contra‐indication were included. Sodium PB was administered at 200 mg/kg/day. Control group included historical controls treated by standard therapy, matched for age, sex, MELD score, and severity of HE. Eighteen patients were included and treated with sodium PB (age: 59 [45–68], male gender: 15 [83%], Child–Pugh B: 8 [44%], Child–Pugh C: 10 [56%], and MELD score: 16 [13–23]). Ammonia levels significantly decreased in the PB as compared to the control group from inclusion to 12 h and from inclusion to 48 h (P = 0.0201 and P = 0.0230, respectively). The proportion of patients displaying neurological improvement was only higher in the PB‐treated group as compared to controls at ICU discharge (15 [83%] vs. 9 [50%], P = 0.0339). ICU discharge survival was significantly higher in patients treated with PB (17 [94%] vs. 9 [50%], P = 0.0017). In cirrhotic patients with overt HE, sodium PB could be effective in reducing ammonia levels and might be effective in improving neurological status and ICU discharge survival. More extensive data, especially a RCT, are mandatory.
Prokaryotes in the WAIS Divide ice core reflect source and transport changes between Last Glacial Maximum and the early Holocene
Authors: Santibáñez Pamela A. , Maselli Olivia J. , Greenwood Mark C. , Grieman Mackenzie M. , Saltzman Eric S. , McConnell Joseph R. , Priscu John C.
Published: January 2018

We present the first long‐term, highly resolved prokaryotic cell concentration record obtained from a polar ice core. This record, obtained from the West Antarctic Ice Sheet (WAIS) Divide (WD) ice core, spanned from the Last Glacial Maximum (LGM) to the early Holocene (EH) and showed distinct fluctuations in prokaryotic cell concentration coincident with major climatic states. The time series also revealed a ~1,500‐year periodicity with greater amplitude during the Last Deglaciation (LDG). Higher prokaryotic cell concentration and lower variability occurred during the LGM and EH than during the LDG. A sevenfold decrease in prokaryotic cell concentration coincided with the LGM/LDG transition and the global 19 ka meltwater pulse. Statistical models revealed significant relationships between the prokaryotic cell record and tracers of both marine (sea‐salt sodium [ssNa]) and burning emissions (black carbon [BC]). Collectively, these models, together with visual observations and methanosulfidic acid (MSA) measurements, indicated that the temporal variability in concentration of airborne prokaryotic cells reflected changes in marine/sea‐ice regional environments of the WAIS. Our data revealed that variations in source and transport were the most likely processes producing the significant temporal variations in WD prokaryotic cell concentrations. This record provided strong evidence that airborne prokaryotic cell deposition differed during the LGM, LDG, and EH, and that these changes in cell densities could be explained by different environmental conditions during each of these climatic periods. Our observations provide the first ice‐core time series evidence for a prokaryotic response to long‐term climatic and environmental processes.
Forward view: advancing health library and knowledge services in England
Authors: Lacey Bryant Sue , Bingham Helen , Carlyle Ruth , Day Alison , Ferguson Linda , Stewart David
Published: January 2018

This article is the fourth in a series on New Directions. The National Health Service is under pressure, challenged to meet the needs of an ageing population, whilst striving to improve standards and ensure decision making is underpinned by evidence. Health Education England is steering a new course for NHS library and knowledge services in England to ensure access to knowledge and evidence for all decision makers. Knowledge for Healthcare calls for service transformation, role redesign, greater coordination and collaboration.

To meet user expectations, health libraries must achieve sustainable, affordable access to digital content. Traditional tasks will progressively become mechanised. Alongside supporting learners, NHS librarians and knowledge specialists will take a greater role as knowledge brokers, delivering business critical services. They will support the NHS workforce to signpost patients and the public to high‐quality information. There is a need for greater efficiency and effectiveness through greater co‐operation and service mergers. Evaluation of service quality will focus more on outcomes, less on counting. These changes require an agile workforce, fit for the future.

There is a bright future in which librarians’ expertise is used to mobilise evidence, manage and share knowledge, support patients, carers and families, optimise technology and social media and provide a keystone for improved patient care and safety.
Aerial canopy temperature differences between fast‐ and slow‐wilting soya bean genotypes
Authors: Bai H. , Purcell L. C.
Published: January 2018

Drought stress limits crop growth and yield in soya bean (Glycine max [L.] Merr.), but there are relatively few tools available to assess the ability of different genotypes to tolerate drought. Aerial infrared image analysis was evaluated as a potential tool for identifying drought tolerance in soya bean. Drought effects were evaluated from late vegetative to mid‐reproductive stages of soya bean development in an experiment with ten genotypes including five slow‐ and five fast‐wilting genotypes that were from a population derived from Benning×PI416937. There were two deficit irrigation levels for 2 years and one deficit irrigation level for the third year along with a fully irrigated control level. When the canopy was completely closed, relative canopy temperature was determined using an infrared camera taken from an aerial platform 50–75 m above the experiment. As water availability decreased, the relative canopy temperature generally increased. Moreover, slow‐wilting soya bean genotypes generally had lower canopy temperature compared to fast‐wilting genotypes, and grain yield was generally positively associated with cool canopy temperatures. The results indicate that the determination of canopy temperature is a promising tool for rapid characterization of drought‐related traits in soya bean.
Changing northern vegetation conditions are influencing barren ground caribou (Rangifer tarandus groenlandicus) post‐calving movement rates
Authors: Rickbeil Gregory J. M. , Hermosilla Txomin , Coops Nicholas C. , White Joanne C. , Wulder Michael A. , Lantz Trevor C.
Published: January 2018

Aim

To quantify changes in vegetation productivity over the past three decades across five barren ground caribou (Rangifer tarandus groenlandicus) herd ranges and assess how these changes are influencing caribou movement rates.

Location

Northwest Territories and Nunavut, Canada.

Methods

As an indicator of vegetation productivity, the enhanced vegetation index (EVI) was calculated on newly developed cloud‐free, gap‐free, Landsat surface reflectance image composites representing 1984–2012. Changes in EVI were assessed on a pixel basis using Theil‐Sen's nonparametric regression and compared across herd ranges and land cover types using generalized least squares regression. Animal movement velocity was calculated from caribou telemetry data and generalized additive mixed models were used to link movement rates with vegetation productivity during the post‐calving phase of the year (July and August).

Results

Vegetation productivity increased across the five caribou herd ranges examined. The largest productivity increase occurred over the ranges of the most western herds, with the largest observed changes in grassland or shrub habitats. Caribou tended to move more slowly through tundra habitats with elevated levels of productivity to a point, while grasslands movement rates decreased linearly with increasing productivity. Movement velocities peaked at intermediate productivity levels in shrub habitats.

Main conclusions

Over the three decades of collected data, barren ground caribou habitats have become more productive, which is consistent with other studies that have documented increases in Arctic vegetation productivity. The more western herds, whose ranges are also closest to the Arctic Ocean, experienced the largest increases in productivity. Finally, we demonstrate that barren ground caribou movement patterns will likely change as a result of changing vegetation productivity in complex manners depending on herd, habitat type and the magnitude of change in vegetation productivity.
Can fortified foods and snacks increase the energy and protein intake of hospitalised older patients? A systematic review
Authors: Mills S. R. , Wilcox C. R. , Ibrahim K. , Roberts H. C.
Published: January 2018

Background

Undernutrition affects over 44% of hospitalised older people, who often dislike oral nutritional supplements (ONS). This review summarises the evidence for an alternative strategy, using energy and protein dense meals (via fortification) or snacks (supplementation) to increase the dietary energy and protein intake of older inpatients.

Methods

A search was conducted through PubMed, EMBASE, CINAHL and the Cochrane database of systematic reviews (May 1996 to May 2016) that used fortification or supplementation to increase the energy or protein intake of patients (mean age ≥60 years) in hospitals or rehabilitation centres.

Results

Ten articles (546 patients, mean age 60–83 years) were identified. Compared with usual nutritional care, six studies using either energy or protein based fortification and supplementation significantly increased intake of energy (250–450 kcal day−1) or protein (12–16 g day−1). Two studies enriched menus with both energy and protein, and significantly increased both energy (698 kcal day−1 and 21 kJ kg−1) and protein (16 g and 0.2 g kg−1) intake compared to usual care. ONS was similar to supplementation in one study but superior to fortification in another. Four studies reported good acceptability of enriched products and two studies that found they were cost‐effective.

Conclusions

Compared with usual nutritional care, energy‐ and protein‐based fortification and supplementation could be employed as an effective, well‐tolerated and cost‐effective intervention to improve dietary intake amongst older inpatients. This strategy may be particularly useful for patients with cognitive impairment who struggle with ONS, and clinical trials are required to compare these approaches and establish their impact on functional outcomes.
On the influence of lipid‐induced optical anisotropy for the bioimaging of exo‐ or endocytosis with interference microscopic imaging
Authors: MARQUES D. , MIRANDA A. , SILVA A.G. , MUNRO P.R.T. , DE BEULE P.A.A.
Published: January 2018

Some implementations of interference microscopy imaging use digital holographic measurements of complex scattered fields to reconstruct three‐dimensional refractive index maps of weakly scattering, semi‐transparent objects, frequently encountered in biological investigations. Reconstruction occurs through application of the object scattering potential which assumes an isotropic refractive index throughout the object. Here, we demonstrate that this assumption can in some circumstances be invalid for biological imaging due to the presence of lipid‐induced optical anisotropy. We show that the nanoscale organization of lipids in the observation of cellular endocytosis with polarized light induces a significant change in far‐field scattering. We obtain this result by presenting a general solution to Maxwell's equations describing light scattering of core–shell particles near an isotropic substrate covered with an anisotropic thin film. This solution is based on an extension of the Bobbert–Vlieger solution for particle scattering near a substrate delivering an exact solution to the scattering problem in the near field as well as far field. By applying this solution to study light scattering by a lipid vesicle near a lipid bilayer, whereby the lipids are represented through a biaxial optical model, we conclude through ellipsometry concepts that effective amounts of lipid‐induced optical anisotropy significantly alter far‐field optical scattering in respect to an equivalent optical model that neglects the presence of optical anisotropy.
Integrative neurohumoural regulation of oxytocin neurone activity in pregnancy and lactation
Authors: Augustine R. A. , Seymour A. J. , Campbell R. E. , Grattan D. R. , Brown C. H.
Published: January 2018

Oxytocin is required for normal birth and lactation. Oxytocin is synthesised by hypothalamic supraoptic and paraventricular nuclei neurones and is released into the circulation from the posterior pituitary gland. Under basal conditions, circulating oxytocin levels are relatively constant but, during birth and lactation, pulsatile oxytocin release triggers rhythmic contraction of the uterus during birth and milk ejection during suckling. Oxytocin levels are principally determined by the pattern of action potential firing, which, in turn, is determined by the interplay between the intrinsic properties of the oxytocin neurones and the regulation of their excitability by surrounding glia, as well as by synaptic drive from their afferent inputs. During birth and suckling, oxytocin neurones fire high‐frequency bursts of action potentials that are coordinated across the population of neurones. These bursts underpin the pulsatile secretion of oxytocin required for normal birth and lactation. Neuroglial regulation of oxytocin neurones changes during pregnancy to favour burst firing. However, these changes still require afferent input activity to drive activity. Although it has long been known that noradrenergic inputs to oxytocin neurones are activated during birth and lactation, the involvement of other afferent inputs is less clear. Here, we provide a brief overview of the current understanding of the mechanisms that regulate oxytocin neurone activity during pregnancy and lactation, and also focus on recent evidence from our laboratory identifying an input that increases kisspeptin production to excite oxytocin neurones in late pregnancy.
Bee community responses to a gradient of oak savanna restoration practices
Authors: Lettow Mitchell C. , Brudvig Lars A. , Bahlai Christie A. , Gibbs Jason , Jean Robert P. , Landis Douglas A.
Published: January 2018

North American Midwestern oak (Quercus spp.) savannas are rare fire‐dependent ecosystems that can support high levels of biodiversity and are the focus of considerable restoration effort due to widespread fire suppression. Due to the predominance of understory forbs in oak savannas, many of which require insect pollination, restoration practices should be evaluated for their potential impacts on pollinator communities. We evaluated bee community responses during the first 2 years of experimental restoration of fire‐suppressed oak savanna in southern Michigan. We used unmanaged references and two different restoration methods (burning only and burning with thinning) to examine the effects of restoration intensity on the abundance, diversity, and functional groups of bees. We found that thinning and burning rapidly increased bee abundance, richness, and Shannon's diversity, relative to unmanaged references, whereas burn‐only restoration largely failed to do so. Thinning and burning also resulted in a distinct bee community after two seasons, while bee communities in burn‐only restoration plots were similar to those from unmanaged references. Differences in bee diversity and community structure between treatments may be due to the influence of restoration on nesting resources, which is reflected in the differential captures of various nesting guilds. Overall, oak savanna restoration by thinning and burning had positive effects on bee diversity, while burning alone only increased bee abundance. We thus illustrate how restoration strategies that typically target plants have broader‐reaching biodiversity benefits. Although restoring savannas through burning alone may eventually shift bee communities, coupling thinning with burning will influence pollinator communities over the shorter term.
Bi‐Morphemic Virtual Length in Yiddish
Authors: Faust Noam
Published: January 2018

This paper examines three apparent exceptions to general processes in the phonology and morphology of standard Yiddish. These are 1) the resistance of several potentially syllabic final consonants to syllabication; 2) the insertion of an extra consonant [n] in some infinitives; and 3) the absence of some diminutive patterns from some nouns. All three cases are resolved by showing that some phonetically short segments are in fact underlyingly long ones, created by morpheme concatenation. The analysis, conducted within Strict CV (Lowenstamm 1996), thus argues for virtual, or “non surface‐true” length.
Assessment of Educational Game Materials and Poster Practices with Rubrics by Expert Educators and Students
Authors: Altay Figen , Bozkurt Kevser
Published: January 2018

The purpose of this study was to investigate the difference between evaluations of the educational game materials and poster practices by students’ own peers and by expert educators using the rubrics created by expert educators and students together. Study included 10 students and 3 educators attended educational game materials course. Students were informed about basic skills of movement, game, game types, game equipment, analytical rubric, and educational game lectures were given to the students for 6 weeks and 80 minutes each week. 12-question knowledge test was used regarding educational games, analytical scoring rubrics, developing game materials and preparing posters. Materials and posters presented in the course were recorded. Evaluation scales were selected by students and expert teachers. Selected peers and educators evaluated 25 videos. One-way analysis of variance and correlation analysis were used for the reliability and repeatability measurements of the students and teachers. R values of 0.96-0.92 were found between students and 0.78-0.86 between educators. For knowledge tests of the groups, according to Wilcoxon paired two-sample test, there was a significant difference in test results (p<.05). The t test was used in the results of the student and educator video evaluations and there was no significant difference between the scores given by the expert educators and the students to the material and poster presentations (p>.05). In conclusion, this study showed that students could make evaluations as good as expert educators when given an answer key such as a scoring rubric that will help them in the evaluation.
Tire-Rim Interaction, a Semi-Analytical Tire Model
Authors: Ballo Federico , Previati Giorgio , Gobbi Massimiliano , Mastinu Gianpiero
Published: January 2018

This paper deals with the development and validation of a semi-analytical tire model able to compute the forces at the interface between tire and rim. The knowledge of the forces acting on the rim is of crucial importance for the lightweight design of wheels. The proposed model requires a limited set of data to be calibrated. The model is compared with complete finite element (FE) models of the tire and rim. Despite its simplicity, the semi-analytical model is able to predict the forces acting on the rim, in agreement with the forces computed by complete FE models. The stress state in the wheel rim, computed by the developed semi-analytical model matches fairly well the corresponding stress state coming from experimental tests.
Drag Reduction and Vortex-Induced Vibration Suppression Behavior of Longitudinally Grooved Suppression Technology Integral to Drilling Riser Buoyancy Units
Authors: Marcollo H. , Potts A. E. , Johnstone D. R. , Pezet P. , Kurts P.
Published: January 2018

Drilling risers are regularly deployed in deep water (over 1500 m) with large sections covered in buoyancy modules. The smooth cylindrical shape of these modules can result in significant vortex-induced vibration (VIV) response, causing an overall amplification of drag experienced by the riser. Operations can be suspended due to the total drag adversely affecting top and bottom angles. Although suppression technologies exist to reduce VIV (such as helical strakes or fairings), and therefore reduce VIV-induced amplification of drag, only fairings are able to be installed onto buoyancy modules for practical reasons, and fairings themselves have significant penalties related to installation, removal, and reliability. An innovative solution has been developed to address this gap: longitudinally grooved suppression (LGS). Two model testing campaigns were undertaken: small scale (subcritical Reynolds number flow), and large scale (postcritical Reynolds number flow) to test and confirm the performance benefits of LGS. The testing campaigns found substantial benefits measured in hydrodynamic performance that will be realized when LGS modules are deployed by operators for deepwater drilling operations.
Two Tandem Cylinders With Passive Turbulence Control in Flow-Induced Vibration: Relation of Oscillation Patterns to Frequency Response
Authors: Lan Kai , Sun Hai , Bernitsas Michael M.
Published: January 2018

Flow-induced vibrations (FIV) are conventionally destructive and should be suppressed. Since 2006, the Marine Renewable Energy Laboratory (MRELab) of the University of Michigan has been studying FIV of multiple cylinders to enhance their response for harnessing hydrokinetic power from ocean, river, and tidal currents. Interactions between multiple cylinders in FIV enable high power-to-volume ratio in a converter consisting of multiple oscillators. This paper investigates experimentally the relation between oscillation patterns and frequency response of two cylinders in tandem. All experiments are conducted in the recirculating channel of the MRELab for 30,000 < Re < 120,000. Phase analysis reveals three dominant patterns of oscillation of two tandem cylinders by calculating the instantaneous phase difference between the two cylinders. This phase difference characterizes each major pattern. Pattern A is characterized by small lead or lag of one cylinder over the other. In pattern B, there is nearly 180 deg out of phase oscillations between the cylinders. In pattern C, the instantaneous phase difference changes continuously from −180 deg to +180 deg. Using frequency spectra and amplitude response, oscillation characteristics of each cylinder are revealed in vortex-induced vibration (VIV) and galloping. Pattern A occurs mostly in galloping when the first cylinder has higher stiffness. Pattern B occurs seldom and typically in the initial VIV branch and transition from VIV to galloping. Pattern C occurs in the upper and lower VIV branches; and in galloping when the lead cylinder has lower stiffness.
Lazy-Wave Buoyancy Length Reduction Based on Fatigue Reliability Analysis
Authors: da Silva Vinícius Ribeiro Machado , Sagrilo Luis V. S. , Vignoles Mario Alfredo
Published: January 2018

The current downturn of the oil and gas industry force managers to take hard decisions about the continuity of projects, resulting in delays, postponements, or even their cancellation. In order to keep with them, the rush for cost reduction is a reality and the industry is pushing the involved parties to be aligned with this objective. The Brazilian presalt region, characterized by ultra-deep waters, faces this scenario where flexible risers in lazy-wave configurations are usually adopted as a solution to safe transfer fluids from sea bed until the floating unit. The smaller the buoyancy length, the cheaper the project becomes, reducing the necessary amount of buoys and the time spent for its installation. This paper investigates the possibility of buoyancy length reduction of lazy-wave configurations by using structural reliability methods on fatigue failure mode. The application of the fatigue reliability approach considers four 6 in flexible riser configurations: an original lazy-wave, a lazy-wave with less 30% of buoyancy length, another one with less 50% of buoyancy length and a free-hanging. Failure probabilities and safety factor calibration curves are shown for each configuration and compared among themselves. The results indicate the possibility of defining a lazy-wave configuration with smaller buoyancy lengths, reaching 75% of reduction without changing the preconized high safety class. Structural reliability analysis is available to help engineers understand the driving random variables of the problem, supporting the actual scenario of cost reduction for better decision-making based on quantified risk.
Pressure Losses in Solar Chimney Power Plant
Authors: Zhou Xinping , Xu Yangyang
Published: January 2018

This technical brief develops a theoretical model of all the pressure losses in the solar chimney power plant (SCPP, also called solar updraft power plant) and analyzes the pressure losses for different chimney internal stiffening appurtenance (SA) structures, different roof heights, and different collector support parameters. Results show that the exit dynamic pressure drop (EDPD) accounts for the majority of the total pressure loss (TPL), while other losses constitute only small proportions of the TPL, and the collector inlet loss is negligible. Pressure losses are strongly related to the mass flow rate, while reasonable mass flow rates excluding too low flow rates have little influence on the pressure loss ratios (PLRs, defined as the ratios of the pressure losses to the TPL) and the total effective pressure loss coefficient (TEPLC). Designing of the SA structure in view of reducing the drag, for example, using the ring stiffeners without wire spoked instead of the spoked bracing wheels (SBWs), reducing the width of the chimney internal rims of SAs, or reducing the number of SAs results in large reduction of the SA PLR and the TPL. Lower roof leading to higher velocity inside the collector, larger supports, or shorter intersupport distance leads to the increase in the support PLR. This technical brief lays a solid foundation for optimization of SCPPs in future.
Effects of Fuel Thickness on Thermo-Mechanical Performance of U10Mo Monolithic Fuel Plates
Authors: Ozaltun Hakan , Rabin Barry H.
Published: January 2018

Monolithic fuels are being considered for conversion of high performance research and test reactors. These plate-type fuels are comprised of a low enrichment, high density U-Mo alloy fuels within an aluminum cladding. Although the plates have demonstrated satisfactory performance; still, use of a high density fuel in a foil form retains technical challenges that could affect the overall performance. To understand performance of this new design during fabrication and irradiation, the plates have been evaluated for various geometrical and operational variables. As a part of these set of parametric sensitivity studies, effects of foil thickness on performance were studied. Because high performance research reactors will utilize different fuel thicknesses, it is necessary to evaluate possible effects for a range of thicknesses that are being considered for various designs. Based on the preliminary design specifications, the fuel thicknesses were varied between the limiting cases. The bounding fuel thicknesses were 0.203 mm as minimum that is projected for ATR, and 0.635 mm as maximum that is projected for MITR. To study possible effects, a behavioral model was developed for a selected plate from RERTR-12 experiments and the plate was simulated with as run irradiation history. The simulations were repeated for a range of fuel thicknesses, while keeping the cladding thickness and the operational parameters the same. The results have indicated that the plates with thicker fuels would have higher temperatures, deformations and shutdown stresses. To investigate the effects of fuel thickness exclusively, operational parameters were scaled. In particular, a second set of simulations with prorated volumetric heat generation rates were performed. The results indicated that the fabrication stresses in the fuel foil decrease with an increasing fuel thickness. On contrary, irradiation stresses of the fuel at shutdown are higher for the plates with thicker fuels. Greater peak deformations occurred in plates with thicker fuels.
Optimum Control Strategy for a Low-Temperature Solar Kalina Cycle Power Generation Under Off-Design Conditions
Authors: Wang Jianyong , Hwang Yunho , Wang Jiangfeng , Dai Yiping
Published: January 2018

Low-temperature Kalina cycle power generation system shows great potential in the region of solar energy utilization. The variation in solar radiation affects the heat source temperature of Kalina cycle, and additionally the cooling water temperature also varies with the seasons. In this paper, the mathematical model of a Kalina cycle used for low-temperature solar power generation is established to investigate the off-design performance of the Kalina cycle under off-design heat source and cooling water temperature using three control strategies including constant pressure regulation method, sliding pressure regulation method and modified sliding pressure regulation method. The results show that when the heat source temperature varies, the modified sliding pressure regulation method could keep the cycle performance and the efficiencies of turbine and pump at a relatively high value, and it could be applied in a wider range of heat source temperature. When the cooling water temperature varies, different control strategies have similar influence on the variations of the cycle performance and the efficiencies of turbine and pump. Based on performance comparison, the modified sliding pressure regulation method is determined to be the optimum control strategy for the Kalina cycle under off-design conditions.
Exploration of the Response of Electrically Actuated MEMS Arches Under the Effect of Mechanical Shock Loads
Authors: Alqasimi Jihad E. , Ouakad Hassen M.
Published: January 2018

This work investigates the modeling and simulation of the dynamic response of MEMS shallow arches under the combined effects of mechanical shock waves and electrostatic actuating forces. The possible instabilities and/or failures that can be considered in any reliability study of such bi-stable structures are numerically examined. The results demonstrate that the simultaneous effects of shock loads and the actuating force can make the bi-stability and/or the instability thresholds of electrically actuated MEMS arches devices much lower than the predicted values when considering their effects independently. The outcomes of this investigation can be very useful to design smart MEMS bi-stable sensors/accelerometers activated at a pre-programmed level of shock and/or abrupt change in the acceleration.
A Numerical Study of Flow Patterns, Drag and Lift for Low Reynolds Number Flow Past Tandem Cylinders of Various Shapes
Authors: Song Yidan , Zhu Rui , Simon Terrence , Xie Gongnan
Published: January 2018

The flow over two different shaped bluff bodies in tandem arrangement was numerically investigated by using the finite volume method with Computational Fluid Dynamics (CFD) techniques. The shape of the downstream main bluff body is a right circular cylinder, with shape unchanged, while the shape of the upstream bluff body varies between: circle, triangle, square, ellipse and cylindrical half-shell. The hydraulic diameters of both front and rear bluff bodies are equal. The analysis is carried out for Reynolds numbers of 100, 300 and 500, and center-to-center distance ratios, L/D, of 1.5, 2, 3, 4.5 and 6. Flow characteristics in terms of the lift and drag coefficients and Strouhal number are analyzed and the vortex shedding patterns around the bluff bodies are described. The influence of the shape of the fore cylinder on the flow characteristics is the innovation point of this paper. It is concluded that the center-to-center distance ratio, L/D, and the shape of the upstream bluff body have important effects on the drag and lift coefficients, vortex shedding frequencies from the two bluff bodies, and flowfield characteristics.
Use of the Moving Frame Method in Dynamics to Model Gyroscopic Control of Small Crafts at Sea: Theory — Part 1
Authors: Nyland Joakim , Teigland Håkon , Impelluso Thomas J.
Published: January 2018

This paper presents new method in dynamics — the Moving Frame Method (MFM) — and uses it to address a challenge faceing Norwegian shipping. Large offshore renewable energy investments require the use of maintenance boats to keep them in operable conditions. Unfortunately, due to rough seas in some project locations, the transferring of crew members from vessel to turbine or platform is fraught with safety concerns. These concerns can be alleviated by controlling the motion of the transfer vessel. This research studies an add-on stability system for marine vessels to ease the process of offshore platform maintenance and crew member safety. Specifically, this research concerns an internal active system — an active gyroscopic stabilizer — and a more powerful method of theoretical and computational mechanics. This paper derives the equations of motion of a model system equipped with dual gyroscopic stabilizers, using the MFM. The equations of motion are numerically solved to obtain a numerical simulation. The method exploits a variational principle with a restricted variation of the angular velocity. The MFM simplifies dynamics, enables a consistent notation, from 2D to 3D analysis and exploits matrix algebra in lieu of the vector cross product. Finally, in a companion paper to this one, the mathematical model and the numerical simulation is verified with experiments conducted in a large-scale wave tank.
Adapting Ant Colony for Topology Optimization of Compliant Mechanisms With Variable Material Density
Authors: Diab Nadim
Published: January 2018

Swarm intelligence optimization techniques are widely used in topology optimization of compliant mechanisms. The Ant Colony Optimization has been implemented in various forms to account for material density distribution inside a design domain. In this paper, the Ant Colony Optimization technique is applied in a unique manner to make it feasible to optimize for the beam elements’ cross-section and material density simultaneously. The optimum material distribution algorithm is governed by two various techniques. The first technique treats the material density as an independent design variable while the second technique correlates the material density with the pheromone intensity level. Both algorithms are tested for a micro displacement amplifier and the resulting optimized topologies are benchmarked against reported literature. The proposed techniques culminated in high performance and effective designs that surpass those presented in previous work.