bluuebunny/crossref_metadata_2025 huggingface dataset:
Fire, hurricane and carbon dioxide: effects on net primary production of a subtropical woodland
Authors: Hungate Bruce A. , Day Frank P. , Dijkstra Paul , Duval Benjamin D. , Hinkle C. Ross , Langley J. Adam , Megonigal J. Patrick , Stiling Peter , Johnson Dale W. , Drake Bert G.
Published: July 2013

Disturbance affects most terrestrial ecosystems and has the potential to shape their responses to chronic environmental change.

Scrub‐oak vegetation regenerating from fire disturbance in subtropical Florida was exposed to experimentally elevated carbon dioxide (CO2) concentration (+350 μl l−1) using open‐top chambers for 11 yr, punctuated by hurricane disturbance in year 8. Here, we report the effects of elevated CO2 on aboveground and belowground net primary productivity (NPP) and nitrogen (N) cycling during this experiment.

The stimulation of NPP and N uptake by elevated CO2 peaked within 2 yr after disturbance by fire and hurricane, when soil nutrient availability was high. The stimulation subsequently declined and disappeared, coincident with low soil nutrient availability and with a CO2‐induced reduction in the N concentration of oak stems.

These findings show that strong growth responses to elevated CO2 can be transient, are consistent with a progressively limited response to elevated CO2 interrupted by disturbance, and illustrate the importance of biogeochemical responses to extreme events in modulating ecosystem responses to global environmental change.
Quantitative plant resistance in cultivar mixtures: wheat yellow rust as a modeling case study
Authors: Sapoukhina Natalia , Paillard Sophie , Dedryver Françoise , de Vallavieille‐Pope Claude
Published: July 2013

Unlike qualitative plant resistance, which confers immunity to disease, quantitative resistance confers only a reduction in disease severity and this can be nonspecific. Consequently, the outcome of its deployment in cultivar mixtures is not easy to predict, as on the one hand it may reduce the heterogeneity of the mixture, but on the other it may induce competition between nonspecialized strains of the pathogen.

To clarify the principles for the successful use of quantitative plant resistance in disease management, we built a parsimonious model describing the dynamics of competing pathogen strains spreading through a mixture of cultivars carrying nonspecific quantitative resistance.

Using the parameterized model for a wheat–yellow rust system, we demonstrate that a more effective use of quantitative resistance in mixtures involves reinforcing the effect of the highly resistant cultivars rather than replacing them. We highlight the fact that the judicious deployment of the quantitative resistance in two‐ or three‐component mixtures makes it possible to reduce disease severity using only small proportions of the highly resistant cultivar.

Our results provide insights into the effects on pathogen dynamics of deploying quantitative plant resistance, and can provide guidance for choosing appropriate associations of cultivars and optimizing diversification strategies.
New paradigms for treatment‐resistant depression
Authors: Zarate Carlos , Duman Ronald S. , Liu Guosong , Sartori Simone , Quiroz Jorge , Murck Harald
Published: July 2013

Clinical depression is a serious mental disorder characterized by low mood, anhedonia, loss of interest in daily activities, and other symptoms, and is associated with severe consequences including suicide and increased risk of cardiovascular events. Depression affects nearly 15% of the population. The standard of care for the last 50 years has focused on monoamine neurotransmitters, including such treatments as selective serotonin reuptake inhibitors (SSRIs) and serotonin–norepinephrine reuptake inhibitors (SNRIs). However, these treatments have significant limitations: they can take weeks before showing mood‐altering effects, and only one to two out of ten patients shows clinical effects beyond those associated with placebo. A major paradigm shift in research into the treatment of depression is underway, based on promising results with the glutamatergic NMDA receptor antagonist ketamine. Further research has demonstrated the significance of glutamatergic pathways in depression and the association of this system with the stress pathway and magnesium homeostasis. Treatment with NMDA receptor antagonists and magnesium have shown the ability to sprout new synaptic connections and reverse stress‐induced neural changes, opening up promising new territory for the development of drugs to meet the unmet need in patients with clinical depression.
Alteration of functional loads after tongue volume reduction
Authors: Ye W. , Duan Y. Z. , Liu Z. J.
Published: July 2013

Structured Abstract

Objectives

An earlier study revealed that the patterns of biomechanical loads on bones around the tongue altered significantly right after tongue volume reduction surgery. The current study was to examine whether these alterations persist or vanish over time post‐surgery.

Design

Five sibling pairs of 12‐week‐old Yucatan minipigs were used. For each pair, one had surgery reducing tongue volume by about 15% (reduction) while the other had same incisions without tissue removal (sham). All animals were raised for 4 weeks after surgery. Three rosette strain gauges were placed on the bone surfaces of pre‐maxilla (PM), mandibular incisor (MI), and mandibular molar (MM); two single‐element gauges were placed across the pre‐maxilla‐maxillar suture (PMS) and mandibular symphysis (MSP), and two pressure transducers were placed on the bone surfaces of hard palate (PAL) and mandibular body (MAN). These bone strains and pressures were recorded during natural mastication.

Results

Overall amount of all loads increased significantly as compared to those in previous study in all animals. Instead of decreased loads in reduction animals as seen in that study, shear strains at PM, MI, and MM, tensile strains at PMS, and pressure at MAN were significantly higher in reduction than sham animals. Compared to the sham, strain dominance shifted at PM, MI, and MM and orientation of tensile strain altered at MI in reduction animals.

Conclusion

A healed volume‐reduced tongue may change loading regime significantly by elevating loading and altering strain‐dominant pattern and orientation on its surrounding structures, and these changes are more remarkable in mandibular than maxillary sites.
Ovariectomy induces osteoporosis in the maxillary alveolar bone: an in vivo micro‐CT and histomorphometric analysis in rats
Authors: Dai Q‐G , Zhang P , Wu Y‐Q , Ma X‐H , Pang J , Jiang L‐Y , Fang B
Published: July 2013

Objective

To investigate whether porotic changes occur in maxillary alveolar bone in ovariectomized rats.

Methods

Thirty‐two 6‐week‐old female Sprague‐Dawley rats were divided into an ovariectomy group (OVX) and a sham‐ovariectomy group (sham). Twelve weeks after surgery, maxillae of 16 rats (eight OVX and eight sham) were analyzed by micro‐CT. Inter‐radicular alveolar bone of the maxillary first molar was reconstructed and analyzed. The remaining 16 maxillae were used for histochemistry, including hematoxylin‐eosin staining and tartrate‐resistant acid phosphatase enzyme staining.

Results

Three‐dimensional reconstructed images of the irregular alveolar bone showed an intuitive view of porotic changes in the OVX group. The alveolar bone in OVX rats had a porous microarchitecture including lower bone mass and a looser structure of more widely separated trabeculae. Bone mineral density (BMD), bone volume fraction (BV/TV), and trabecular thickness (Tb.Th.) were significantly lower in the OVX group than those in the sham group (P < 0.05). Trabecular separation (Tb.Sp.) increased significantly in the OVX rats compared to the sham rats (P < 0.05). Histomorphometric analysis of alveolar bone also revealed porotic changes in the OVX rats. Bone area ratio significantly decreased in the OVX group compared with the sham group (P < 0.01). There were also more osteoclasts present in the alveolar bone of OVX rats compared to sham rats (P < 0.05).

Conclusion

Ovariectomy induces osteoporosis in maxillary alveolar bone in rats, which may be related to the increased number of osteoclasts.
Socioeconomic disparities of periodontitis in Koreans based on the KNHANES IV
Authors: Kim D‐W , Park J‐C , Rim TH‐T , Jung U‐W , Kim C‐S , Donos N , Cha I‐H , Choi S‐H
Published: July 2013

Objectives

The aim of this study was to identify the socioeconomic factors associated with the prevalence of periodontitis in Koreans.

Methods

Cross‐sectional data from 12 763 subjects, 15 years old and above, who underwent periodontal examinations were obtained from the Korean National Health and Nutrition Examination Survey IV (2007–209). Multivariate linear and logistic regression analyses were applied to estimate the association between socioeconomic indicators and prevalence of periodontitis.

Results

A significant association was found between increasing age and periodontitis. Participants with higher income were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.78–0.98, and aOR = 0.7 and 95% CI = 0.60–0.80 in the middle and highest quintiles of monthly household income, respectively). In addition, participants living in rural areas were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.81–0.99), and current smokers were more likely to have periodontitis (aOR = 1.7 and 95% CI = 1.49–1.89). The analysis of comorbidities revealed that individuals with diabetes mellitus (DM) were significantly more likely to have periodontitis (aOR = 1.4 and 95% CI = 1.18–1.68).

Conclusions

In a rapidly increasing Korean population, the lower socioeconomic groups as well as individuals with DM were significantly more likely to present with periodontitis.
Impact of Low‐Dose Dipyridamole Injection on Adenosine Test after Pulmonary Vein Isolation
Authors: MIYAZAKI SHINSUKE , TANIGUCHI HIROSHI , UCHIYAMA TAKASHI , KUSA SHIGEKI , NAKAMURA HIROAKI , HACHIYA HITOSHI , HIRAO KENZO , IESAKA YOSHITO
Published: July 2013

Background

Dipyridamole increases the levels of extracellular adenosine. The study investigates the impact of low‐dose intravenous dipyridamole on adenosine test after pulmonary vein (PV) isolation (PVI).

Methods and Results

This prospective study included 12 paroxysmal atrial fibrillation (AF) patients (61 ± 12 years; nine men) who underwent PVI at the first procedure. Transient PV reconnection was provoked by adenosine test in 4/48 PVs. In 44 PVs without reconnection, intravenous infusion of low‐dose (10 mg) dipyridamole preceded the adenosine test. Additional six patients (PVs) with transient dormant conduction were included. Among the total 10 PVs with transient reconnection, it was eliminated by radiofrequency (RF) application(s) until no dormant conduction was exposed by adenosine test(s) in five PVs. Then, dipyridamole potentiated adenosine test was undertaken to provoke dormant conduction (group 1). In the remaining five PVs, dipyridamole potentiated adenosine test was followed by RF elimination of conduction gap and repeat adenosine test to confirm complete elimination (group 2). Low‐dose dipyridamole prolonged the duration of adenosine‐induced atrioventricular block without vasodilatatory hypotension. There was no evidence of reconnection in 44 PVs without dormant conduction and in group 1 wherein transient reconnection was eliminated by 4.8 ± 3.2 RF applications in 8.8 ± 3.0 minutes and adenosine injected 3.1 ± 1.8 times. In group 2, dipyridamole plus adenosine test revealed the same dormant conduction that persisted longer than during adenosine alone. It was eliminated by single RF application in 3.4 ± 0.9 minutes, and adenosine was injected once.

Conclusions

Low‐dose dipyridamole safely prolongs the electrophysiological effects of adenosine test without provoking additional PV reconnection. This allows sustained visualization and facilitates complete RF elimination of the electrical conduction gap.
Morphofunctional analysis of Svobodaina species (Brachiopoda, Heterorthidae) from south‐western Europe
Authors: Colmenar Jorge , Harper David A. T. , Villas Enrique
Published: July 2013

Geometric morphometric methods applied to the ventral muscle field outline of the various species of Svobodaina from south‐western Europe identify criteria for discriminating among this key cluster of brachiopod species. These data indicate the close relationship between the patterns of the ventral muscle field in the Svobodaina species and the environmental conditions where each inhabited; the fields are better developed in species related to high‐energy environments. For example, S. armoricana, with the smallest diductor scars, would have inhabited the quiet marine environments of the lower offshore or within protected lagoonal settings. S. feisti would have inhabited the upper offshore, a more energetic environment than S. armoricana. Finally, S. havliceki, with the largest diductor scars, would have thrived in the most energetic environments among all the south‐western European Svobodaina species, living just above the fair‐weather wave base in the lower shoreface. The palaeoecological results suggest a distribution of Svobodaina species during the Late Ordovician along an onshore–offshore transect across the shallow marine platforms of the Mediterranean margin of Gondwana. On the other hand, the occurrence in some localities of several species with overlapping ranges or within the same assemblage indicates that the biostratigraphical efficacy of the genus is restricted. Thus, the previously defined taxon‐range biozones characterized by Svobodaina species of the north Gondwanan margin are in need of reassessment. The morphology of Svobodaina may be a considerable aid to environmental analyses rather than to precise biostratigraphical correlations.
Mansuyia Sun, and Tsinania Walcott, from the Furongian of North China and the evolution of the trilobite family Tsinaniidae
Authors: Park Tae‐Yoon , Kim Ju Eon , Lee Seung‐Bae , Choi Duck K.
Published: July 2013

The Furongian trilobite family Tsinaniidae is characterized by a highly effaced surface and forms an important constituent of the Furongian trilobite faunas of east Gondwana. However, the origin of the characteristic morphology of this family has remained unclear. Only recently has the tsinaniid trilobite Lonchopygella megaspina been suggested to represent an intermediate stage in the evolutionary transition to other tsinaniids on the basis of the trunk segmentation. Here, we report successive occurrences of four species of the kaolishaniid genus Mansuyia and a tsinaniid trilobite Tsinania canens from the Furongian (late Cambrian) Chaomidian Formation in Shandong Province, China. A cladistic analysis including these taxa reveals that the four species of Mansuyia constitute stem‐group taxa to the family Tsinaniidae, rendering Mansuyia and the Kaolishaniidae paraphyletic. The youngest species of Mansuyia, M. taianfuensis, turns out to be the immediate sister taxon of the Tsinaniidae, displaying a closely similar morphology to the tsinaniid trilobite, Shergoldia laevigata. The generic and familial boundary therefore situated between M. taianfuensis and S. laevigata.
Vogt‐Koyanagi‐Harada Disease in an Adolescent Boy
Authors: Bilgiç Özlem , Gündüz Abuzer , Kaya Kısmet
Published: July 2013

Vogt‐Koyanagi‐Harada (VKH) disease is a rare multiorgan disorder that affects the melanocytes of the eyes, skin, inner ear, and meninges. It is more common in women and in patients 30 to 50 years of age; it is rarely seen in children. We report a 14‐year‐old boy who meets the criteria for complete VKH disease.
Subungual Soft Tissue Chondroma with Nail Deformity in a Child
Authors: Eun Young Sun , Kim Mi Ri , Cho Baik Kee , Yoo Gyeol , Park Hyun Jeong
Published: July 2013

Soft tissue chondroma is a rare benign tumor of the cartilage. It occurs commonly in distal extremities of middle‐aged patients. It is usually asymptomatic and grows slowly, making early diagnosis difficult. We report a 10‐year‐old patient with a 1‐year history of a subungual soft tissue chondroma on her left fifth finger. The lesion arose from nail bed and distal nail matrix, resulting in nail dystrophy. Magnetic resonance imaging revealed a soft tissue tumor in the subungual region and soft tissue chondroma was diagnosed, based on histopathologic findings. Dermatologists should consider soft tissue chondroma in the differential diagnosis of subungual tumors of children.
The joys of genuine giving: Approach and avoidance sacrifice motivation and authenticity
Authors: IMPETT EMILY A. , JAVAM LEYLA , LE BONNIE M. , ASYABI‐ESHGHI BEHZAD , KOGAN ALEKSANDR
Published: July 2013

Why do sacrifices undertaken in pursuit of approach and avoidance goals differentially influence well‐being and relationship quality? A cross‐sectional study (Study 1), an experiment (Study 2), and a 2‐week daily experience study (Study 3) demonstrate that the personal and interpersonal outcomes of approach and avoidance sacrifice goals in dating and married relationships are mediated by felt authenticity. When people sacrificed for approach goals such as to make their partner happy, they felt more authentic, in turn contributing to greater personal and relationship well‐being. However, when they sacrificed for avoidance goals such as to avoid conflict, they felt less authentic, in turn detracting from personal and relationship well‐being. Implications for research and theory on motivational processes in close relationships are discussed.
Variable mycorrhizal benefits on the reproductive output of Geranium sylvaticum, with special emphasis on the intermediate phenotype
Authors: Varga S. , Kytöviita M.‐M.
Published: July 2013

In several gynodioecious species, intermediate sex between female and hermaphrodite has been reported, but few studies have investigated fitness parameters of this intermediate phenotype. Here, we examined the interactions between plant sex and arbuscular mycorrhizal (AM) fungal species affecting the reproductive output of Geranium sylvaticum, a sexually polymorphic plant species with frequent intermediate sexes between females and hermaphrodites, using a common garden experiment. Flowering phenology, AM colonisation levels and several plant vegetative and reproductive parameters, including seed and pollen production, were measured. Differences among sexes were detected in flowering, fruit set, pollen production and floral size. The two AM species used in the present work had different effects on plant fitness parameters. One AM species increased female fitness through increasing seed number and seed mass, while the other species reduced seed mass in all sexes investigated. AM fungi did not affect intermediate and hermaphrodite pollen content in anthers. The three sexes in G. sylvaticum did not differ in their reproductive output in terms of total seed production, but hermaphrodites had potentially larger fathering ability than intermediates due to higher anther number. The ultimate female function – seed production – did not differ among the sexes, but one of the AM fungi used potentially decreased host plant fitness. In addition, in the intermediate sex, mycorrhizal symbiosis functioned similarly in females as in hermaphrodites.
Maternal Weight Status, Cord Blood Leptin and Fetal Growth: a Prospective Mother–Child Cohort Study (Rhea Study)
Authors: Karakosta Polyxeni , Georgiou Vaggelis , Fthenou Eleni , Papadopoulou Eleni , Roumeliotaki Theano , Margioris Andrew , Castanas Elias , Kampa Marilena , Kogevinas Manolis , Chatzi Leda
Published: July 2013

Background

Leptin is an adipocyte‐secreted hormone that regulates energy homeostasis, while its role in fetal programming remains poorly understood. We aimed to evaluate the effect of maternal weight status on cord blood leptin levels and their combined effect on fetal growth.

Methods

We included 638 mother–child pairs from the prospective mother–child cohort ‘Rhea’ study in Crete, Greece with singleton pregnancies, providing cord blood serum samples for leptin analysis and complete data on birth outcomes. Multivariable logistic and linear regression models were used adjusting for confounders. Generalised additive models were used to explore the form of the relationship between cord leptin and continuous birth outcomes.

Results

Log cord leptin was positively associated with birthweight {β‐coef: 176.5 [95% confidence interval (CI): 133.0, 220.0] }, ponderal index (β‐coef: 1.0 [95% CI: 0.6, 1.4] ) and gestational age (β‐coef: 0.7 [95% CI: 0.5, 0.8] ). Excessive weight gain during pregnancy was associated with a threefold increased risk for cord hyperleptinaemia {relative risk (RR): 3.0, [95% CI: 1.5, 6.3] }. Maternal pre‐pregnancy overweight/obesity [body mass index (BMI) ≥25 kg/m2] increased the risk of giving birth to a hyperleptinaemic neonate (RR: 2.1 [95% CI: 1.4, 3.2] and the effect of log leptin on birthweight (β‐coef: 219.1 [95% CI: 152.3, 285.9] compared with women with a BMI <25 kg/m2 (β‐coef: 150.5 [95% CI: 93.1, 207.9].

Conclusions

Higher cord blood leptin levels are associated with increased size at birth and gestational age, while maternal pre‐pregnancy BMI and weight gain during pregnancy represent significant indicators of cord blood leptin.
Chloroplast‐targeted Hsp90 plays essential roles in plastid development and embryogenesis in Arabidopsis possibly linking with VIPP1
Authors: Feng Juanjuan , Fan Pengxiang , Jiang Ping , Lv Sulian , Chen Xianyang , Li Yinxin
Published: July 2013

The Arabidopsis genome contains seven members of Hsp90. Mutations in plastid AtHsp90.5 were reported to cause defects in chloroplast development and embryogenesis. However, the exact function of plastid AtHsp90.5 has not yet been defined. In this study, albino seedlings were found among AtHsp90.5 transformed Arabidopsis, which were revealed to be AtHsp90.5 co‐suppressed plants. The accumulation of photosynthetic super‐complexes in the albinos was decreased, and expression of genes involved in photosynthesis was significantly down‐regulated. AtHsp90.5 T‐DNA insertion mutants were embryo‐lethal with embryo arrested at the heart stage. Further investigation showed AtHsp90.5 expression was up‐regulated in the siliques at 4 days post anthesis (DPA). Confocal microscopy proved AtHsp90.5 was located in the chloroplasts. Plastid development in the AtHsp90.5 mutants and co‐suppressed plants was seriously impaired, and few thylakoid membranes were observed, indicating the involvement of AtHsp90.5 in chloroplast biogenesis. AtHsp90.5 was found to interact with vesicle‐inducing protein in plastids 1 (VIPP1) by bimolecular fluorescence complementation system. The ratio between VIPP1 oligomers and monomers in AtHsp90.5 co‐suppressed plants drastically shifted toward the oligomeric state. Our study confirmed that AtHsp90.5 is vital for chloroplast biogenesis and embryogenesis. Further evidence also suggested that AtHsp90.5 may help in the disassembly of VIPP1 for thylakoid membrane formation and/or maintenance.
Use of Relief Contrast®Objective to Improve Sperm Morphometric Analysis by Isas®Casa System in the Ram
Authors: Yániz JL , Capistrós S , Vicente‐Fiel S , Soler C , Núñez de Murga M , Santolaria P
Published: July 2013

Contents

The aim of this study was to develop a new method for morphometric assessment of the sperm head and acrosome in the ram. Ejaculates from 10 adult males were collected using an artificial vagina. For each ejaculate, 10 semen smears were prepared, air‐dried and divided (in pairs) into the following five treatment groups: (i) washed in distilled water and allowed to dry without further processing (DRY); (ii) fixed in 50% methanol (MET); (iii) fixed in 2% glutaraldehyde (GLUT); (iv) fixed and stained with Hemacolor®(HEM) and (v) fixed and stained with SpermBlue®(SB). The prepared slides were examined with a 40 × Relief Contrast®objective (RC) and processed withISAS®commercial software. The use ofRCoptics increased the contrast between acrosome and sperm head, allowing capture and morphometric analysis byISASof sperm heads and the acrosome, even in non‐stained samples.METandGLUTgroups resulted in a lower number of acceptable, that is, correctly delineated, sperm heads than those in theSB, andSBandHEMgroups, respectively (p < 0.05). The higher proportion of sperm discarded inMETandGLUTgroups may be explained by a higher presence of artefacts. For the majority of the primary morphometric parameters of the sperm head and the acrosomal area, the relationship between treatments was the following:GLUT>HEM≥MET≥SB>DRY. When studying the proportion of the sperm head covered by the acrosome, the relation between treatments was:MET>DRY=GLUT=SB>HEM. It was concluded that the new method for sperm morphometric assessment allows the simultaneous assessment of sperm head and acrosome in the ram by the first time, even in unprocessed semen smears.
Effect of hCG and eCG Treatments on Prostaglandins Synthesis in the Porcine Oviduct
Authors: Małysz‐Cymborska I , Ziecik AJ , Waclawik A , Andronowska A
Published: July 2013

Contents

The oviduct plays a crucial role in fertilization, gamete maturation and embryo transport. Prostaglandins are some of the main factors determining its roles. The present study investigated the influence of oestrus synchronization and superovulation on prostaglandins synthesis in the porcine oviduct. Mature cross‐bred gilts after exhibiting oestrous cycles were divided into four groups: I, cyclic; II, inseminated; III, synchronized and inseminated; and IV, superovulated and inseminated. Oviducts were collected on the third day of the oestrous cycle or after insemination and divided into isthmus and ampullary parts. This study demonstrated lower mRNA (in the isthmus and ampulla; p < 0.05, p < 0.001, respectively) and protein prostaglandin endoperoxide synthase 2 expression (in the isthmus; p < 0.001) in gilts treated with human chorionic gonadotrophin/equine chorionic gonadotrophin (hCG/eCG) compared with Group II that were inseminated only. In addition, hCG and eCG treatment decreased mPGES‐1 mRNA levels in Groups III and IV, in both the isthmus (p < 0.01 in III, p < 0.001 in IV) and ampulla (p < 0.001). The prostaglandin E2 content of oviductal tissues was significantly lower in Groups III (p < 0.05) and IV (p < 0.01 in isthmus, p < 0.0001 in ampulla) compared with Group II. mRNA and protein levels of PGFS in Group IV in the oviductal isthmus were higher (p < 0.01) compared with the non‐treated Group II. In effect, the amount of prostaglandin F2α in oviductal tissues of gilts treated with hCG/eCG was significantly elevated (p < 0.001 in isthmus of Groups III and IV; p < 0.05 in ampulla of Group IV). Differential expression of the factors analysed in gilts treated with exogenous gonadotrophins suggests that hCG/eCG stimulation affects prostaglandins synthesis pathway. These changes can alter oviduct functions and in turn affect gamete maturation and fertilization as well as development of embryos and their transport to the uterus.
On the Toughness Response of iPP and sPP/MWNT Nanocomposites
Authors: Mouzakis D. E. , Papanicolaou G. C. , Giannadakis K. , Zuburtikudis I.
Published: July 2013

Nanocomposites based in polypropylene (both syndiotactic and isotactic) and multiwall carbon nanotubes (MWNTs) directly blended in the melt via micro‐extrusion, were studied. The aim was to determine the role of MWNTs, on the creation of the plastic zone and crack propagation in double‐cracked tensile specimens. Essential work of fracture toughness testing was performed on these nanocomposites. In all cases, the effect of MWNT weight fraction on the above properties was extensively studied. Data obtained have shown a non‐linear relationship of almost all properties with MWNTs content.

Scanning electron microscopy revealed that a micro crack/craze bridging mechanism can be detected in polymer matrix/ MWNT nanocomposites. This mechanism was observed in the fibrillated areas of the specimens' fractured surfaces. The results obtained showed a promising role of the nanotubes as tougheners for future nanocomposites' applications. Ductile‐to‐brittle transition was confirmed for MWNT contents above 1 wt%.
The Reinforcement Effect of Strain Gauges Embedded in Low Modulus Materials
Authors: Ajovalasit A. , Fragapane S. , Zuccarello B.
Published: July 2013

The reinforcement effect of electrical resistance strain gauges is well‐described in the literature, especially for strain gauges installed on surface. This paper considers the local reinforcement effect of strain gauges embedded within low Young modulus materials. In particular, by using a simple theoretical model, already used for strain gauges installed on the surface, it proposes a simple formula that allows the user to evaluate the local reinforcement effect of a generic strain gauge embedded on plastics, polymer composites, etc. The theoretical analysis has been integrated by numerical and experimental analyses, which confirmed the reliability of the proposed model.
Determinants of the degradation of soil structure in vineyards with a view to conversion to organic farming
Authors: Polge de Combret ‐ Champart L. , Guilpart N. , Mérot A. , Capillon A. , Gary C.
Published: July 2013

In perennial crops such as grapevine, there is a considerable risk of soil degradation caused by mechanization. Organic farming may increase traffic and result in more intensive soil structure degradation, especially on wet soil. Soil structure was observed in 69 soil profiles from 12 vineyards (Languedoc‐Roussillon, Bordeaux, Provence, Burgundy, Rhône Valley) to study the relationships between permanent soil characteristics (texture, stoniness, waterlogging), cultivation practices (technical operations, traffic, farm equipment) and soil structure. Compaction zones were identified in soil profiles viewed perpendicularly to the grapevine rows. The percentage of compacted area and a score for compaction intensity were assessed in the top 0.5 m of the soil profile in three soil compartments defined by the distance from the grapevine row: (1) 0 to 0.2 m (2) 0.2 m to 0.5 m and (3) 0.5 m to the middle of the inter‐row. Most soil profiles exhibited considerable compaction: 75% of the soil profiles were compacted in compartments 2 or 3. Intensity correlated with depth of compaction in compartment 2 – the deeper the compaction, the greater the compaction intensity. Four types of soil profiles could be identified, depending on the location of compacted zones and of their intensity of compaction. The factors that determined the types of soil profiles were as follows: soil vulnerability to compaction, use of moderating practices (practices that limit the risk of compaction) and traffic geometry. A statistical analysis resulted in a decision tree that provides a useful basis to choose cultivation practices that limit damage to or improve soil structure.
Effectiveness of a cardiac surgery–specific transfusion protocol
Authors: Bilecen Süleyman , de Groot Joris A.H. , Kalkman Cor J. , Spanjersberg Alexander J. , Moons Karel G.M. , Nierich Arno P.
Published: July 2013

Background

Cardiac surgery is often complicated by excessive bleeding that is commonly treated with blood products. In the year 2009 a transfusion protocol was introduced specifically designed for cardiac surgery procedures. This study aims to evaluate the effect of this protocol on transfusion of blood products and the occurrence of clinical events.

Study Design and Methods

This was a nonrandomized intervention study. The index group was transfused according to a tailor‐made transfusion protocol (operation in 2009/2010) and the control group was transfused according to the Dutch national transfusion guideline (operation in 2007/2008). The primary outcome was mean number of units transfused and proportion of patients transfused. Secondary outcomes were in‐hospital mortality, myocardial infarction, cerebrovascular accident or transient ischemic attack, renal injury or failure, rethoracotomy, and prolonged mechanical ventilation.

Results

The control group comprised 2685 patients and the index group 2534 patients. The tailor‐made transfusion protocol resulted in a decrease of patients transfused with red blood cells (RBCs) and fresh‐frozen plasma (FFP) during surgery with odds ratio of 0.69 (95% confidence interval [CI], 0.55‐0.86) and 0.63 (95% CI, 0.46‐0.86), respectively. Fewer myocardial infarctions were observed in the index group with OR of 0.67 (95% CI, 0.47‐0.96).

Conclusion

The cardiac surgery–specific transfusion protocol resulted in fewer patients transfused with RBCs and FFP and a lower incidence of myocardial infarction. This tailor‐made protocol has led to a more judicious use of blood products and is a basis for further refinement of coagulation management during cardiac surgery procedures.
Systematic Literature Review of Incidence Rates of Low‐Speed Vehicle Run‐Over Incidents in Children
Authors: Griffin Bronwyn , Watt Kerrieanne , Kimble Roy , Wallis Belinda , Shields Linda
Published: July 2013

Aim

To systematically review the literature investigating the incidence of fatal and or nonfatal low‐speed vehicle run‐over (LSVRO) incidents in children aged 0–15 years.

Methods

The following databases were searched using specific search terms, from their date of conception up to June 2011: Cochrane Library, Medline, CINAHL, Embase, AMI, Sociological Abstracts, ERIC, PsycArticles, PsycInfo, Urban Studies and Planning; Australian Criminology Database; Dissertations and Thesis; Academic Research Library; Social Services Abstracts; Family and Society; Scopus; and Web of Science. A total of 128 articles were identified in the databases (33 found by hand searching). The title and abstract of these were read, and 102 were removed because they were not primary research articles relating to LSVRO‐type injuries. Twenty‐six articles were assessed against the inclusion (reporting population level incidence rates) and exclusion criteria, 19 of which were excluded, leaving a total of five articles for inclusion in the review.

Findings

Five studies were identified that met the inclusion criteria. The incidence rate in nonfatal LSVRO events varied in the range of 7.09 to 14.79 per 100,000 and from 0.63 to 3.2 per 100,000 in fatal events.

Discussion

Using International Classification of Diseases codes for classifying fatal or nonfatal LSVRO incidents is problematic as there is no specific code for LSVRO. The current body of research is void of a comprehensive secular population data analysis. Only with an improved spectrum of incidence rates will appropriate evaluation of this problem be possible, and this will inform nursing prevention interventions. The effect of LSVRO incidents is clearly understudied. More research is required to address incidence rates in relation to culture, environment, risk factors, car design, and injury characteristics.

Conclusions

The lack of nursing research or policy around this area of injury, most often to children, indicates a field of inquiry and policy development that needs attention.
Prevention and Control of Rabies in an Age of Global Travel: A Review of Travel‐ and Trade‐Associated Rabies Events –UnitedStates, 1986–2012
Authors: Lankau E. W. , Cohen N. J. , Jentes E. S. , Adams L. E. , Bell T. R. , Blanton J. D. , Buttke D. , Galland G. G. , Maxted A. M. , Tack D. M. , Waterman S. H. , Rupprecht C. E. , Marano N.
Published: July 2013

Rabies prevention and control efforts have been successful in reducing or eliminating virus circulation regionally through vaccination of specific reservoir populations. A notable example of this success is the elimination of canine rabies virus variant from theUnitedStates and many other countries. However, increased international travel and trade can pose risks for rapid, long‐distance movements of ill or infected persons or animals. Such travel and trade can result in human exposures to rabies virus during travel or transit and could contribute to the re‐introduction of canine rabies variant or transmission of other viral variants among animal host populations. We present a review of travel‐ and trade‐associated rabies events that highlight international public health obligations and collaborative opportunities for rabies prevention and control in an age of global travel. Rabies is a fatal disease that warrants proactive coordination among international public health and travel industry partners (such as travel agents, tour companies and airlines) to protect human lives and to prevent the movement of viral variants among host populations.
Combining Variation Simulation With Thermal Expansion Simulation for Geometry Assurance
Authors: Lorin Samuel , Lindkvist Lars , Söderberg Rikard , Sandboge Robert
Published: July 2013

In every set of assembled products, there are geometrical variations and deviations from nominal dimensions. This can lead to products that are difficult to assemble or products not fulfilling functional or aesthetical requirements. In several industries, variation simulation is used to predict assembly variation in the development phase. This analysis is usually done under room temperature conditions only. However, for some materials, such as plastics, the thermal expansion can be significant in the intended environmental span of the product. In an assembly, this can lead to thermal stresses and parts that will deform. To avoid this problem, locating schemes need to be designed to allow for the right behavior while exposed to varying temperatures. In this work, the effect of thermal expansion is studied in the context of variation simulation. A virtual tool for this purpose is also presented. Two case studies from the automotive industry are used where the combined effect of thermal expansion and assembly variation is analyzed. It is shown that it may not be sufficient to simply add the result from thermal analysis to assembly variation. Hence, to assure the geometrical and functional quality of assembled products during usage variation simulations need to be combined with thermal expansion simulation.
Performance Study of a Photovoltaic Thermal System With an Oscillatory Flow Design
Authors: Rahou M. , Othman M. Y. , Mat S. , Ibrahim A.
Published: July 2013

In this study, integrated photovoltaic thermal roofing system has been successfully built and tested to improve the photovoltaic efficiency as well as providing domestic hot water supply. The major components of the solar photovoltaic thermal (PV/T) collector in this study comprise of amorphous silicon solar cells arranged in series that were adhered to the roofing structure. Unified structure of copper tube absorbers with oscillatory flow configuration was attached to the back plate which was insulated with glass wool from the surrounding. The entire PV/T collector has been mounted on a manual two degree solar tracker that can be adjusted toward the exposure of maximum solar irradiation. The effect of altering parameters such as water mass flow rate and irradiance on the collector's efficiencies has been carried out. The combined efficiency including photovoltaic and thermal efficiencies varies from 70.53% to 81.5% in the PV/T system with the oscillatory flow configuration. The present study has shown better results in terms of PV/T efficiency in comparison with the prior corresponding experiments.
Transport Phenomena in Two-Phase Liquid-Liquid Micro-Reactors
Authors: Plouffe Patrick , Anthony Ross , Donaldson Adam , Roberge Dominique M. , Kockmann Norbert , Macchi Arturo
Published: July 2013

Micro-reactors offer distinct advantages over batch reactors currently used within the pharmaceutical and fine chemical industries. Their high surface area-to-volume ratios allow for increased heat and mass transfer, which is important for controlling reaction selectivity. In addition, micro-reactors are compatible with continuous processing technology, circumventing the time delays inherent to batch systems. Rapid mixing of reactants within micro-reactors is, however, limited by the inherent difficulty of generating turbulence at reduced geometry scales. Several different passive mixing strategies have been proposed in order to produce eddy-based secondary flows and chaotic mixing. This study examines the effectiveness of these strategies by comparing the energy-density normalized heat and mass transfer coefficients for a selection of industrial micro-reactors. First single, then two-phase liquid-liquid experiments were conducted. Pressure drop measurements were obtained to calculate friction factors and to verify the presence of eddy-based secondary flows. A hot heat exchange fluid and temperature measurements were used to estimate the internal convective heat transfer coefficients within each structure. Volumetric mass transfer coefficients were also determined for the mutual extraction of partially miscible n-butanol and water. Semi-empirical correlations for the reactors’ friction factor and Nusselt number as well as a description of the overall mass transfer coefficient based on energy dissipation are presented.
High Efficiency Minichannel and Mini-Impingement Cooling Systems for Hybrid Electric Vehicle Electronics
Authors: Ekkad Srinath V. , Parida Pritish , Ngo Khai
Published: July 2013

Over the years, electronic equipment, especially semiconductor based devices, have found their applications in almost all fields of research. The demand for more power and performance from such electronic equipment has constantly been growing resulting in an increased amount of heat dissipation from these devices. While conventional cooling solutions have performed the task of heat removal, no straightforward extension has been possible for significantly high heat fluxes dissipated by smaller and more efficient electronic devices. Thermal management of high-density power control unit for hybrid electric vehicle is one such challenging application. Over the last few years, the performance of this power control unit has been improved and size has been reduced to attain higher efficiency and performance causing the heat dissipation as well as heat density to increase significantly. Efforts are constantly being made to reduce the PCU size even further and also to reduce the manufacturing costs. As a consequence, heat density will go up (∼200–250 W/cm2) and thus, a better high performance cooler/heat exchanger is required which can operate under the existing cooling system design (pressure drop limitation) and at the same time, maintain active devices temperature within optimum range (<120–125°C) for higher reliability.

The focus of this paper is to discuss the development of various cooling options for high heat flux dissipating devices with severe size constraints. A parametric and optimization study on the selected designs was performed. Finally, the optimized cooler/heat exchanger was tested under actual running conditions. The methodology was to explore various high performance cooling options such as impinging jets, pin fins, and ribbed mini-channels and to arrive at new promising, conceptual designs. These new designs were then compared against similar conventional designs both numerically and experimentally. Additionally, conjugate heat transfer simulations were performed on partial packaging model to compare the various designs. Experiments were also performed to validate the simulation models and characterize the meshing parameters to perform cost and time effective calculations/simulations.
Curvature-Induced Dielectrophoresis (C-iDEP) for Microfluidic Particle and Cell Manipulations
Authors: Xuan Xiangchun
Published: July 2013

Dielectrophoresis (DEP) is a powerful tool for particle and cell manipulations in microfluidic devices. Our group has recently developed a new method that exploits the intrinsic curvature of microchannel walls for a diverse electrical control of particle and cell motions, which is termed Curvature-induced Dielectrophoresis (C-iDEP). Due to the variation in path length for electric current, the electric field becomes inherently non-uniform within a microchannel turn. Thus induced DEP can generate a cross-stream particle motion, which is a nonlinear function of electric field and superimposed to the linear electrokinetic motion enabling flexible particle manipulations. This paper presents our recent results on the deflection, focusing, filtration, and separation of particles and cells in curved microchannels by the use of C-iDEP.
Development of a Microchannel Heat Exchanger for Aerospace Applications
Authors: Strumpf Hal , Mirza Zia
Published: July 2013

Honeywell Aerospace has been developing microchannel heat exchangers for aerospace use. These heat exchangers offer significant reduction in volume and some reduction in weight compared to state-of-the-art aerospace heat exchangers constructed using offset plate and fin interupted surfaces.

A microchannel heat exchanger was designed based on the requirements and available envelope for an aerospce liquid-to-air heat exchanger presently in service. The new micochannel heat exchanger was fabricated and a full testing campaign was undertaken to validate the design approach and generate appropriate adjustment factors for pressure drop and heat transfer. Based on this correlated model, the heat exchanger was re-sized for the required conditions. This updated design shows a significant reduction in size compared to the existing heat exchanger. In addition, Honeywell now has a validated approach enabling accurate design and optimization of microchannel heat exchangers for diverse problem conditions.
Blood Velocity Profile Measurements in Microchannels Using Micro-Particle Image Velocimetry
Authors: Pitts Katie L. , Fenech Marianne
Published: July 2013

Experimental studies of blood microflows in rectangular biocompatible polymer microchannels measured using micro-particle image velocimetry are reported. The data processing methods, data collection methods, and choice of channel material are demonstrated to impact the velocity profile measurements obtained. Results show that the use of red blood cells as tracer particles creates a large depth of correlation which can approach the size of the vessel itself and decrease the accuracy of the method. It is shown that changing the amount of overlap in the post-processing parameters affects the results by nearly 10%. The velocity profile is studied as a function of the flow rate of the blood, the hematocrit, or percentage of red blood cells, the shape of the channel, and the channel material. The results highlighted here show that the best processing options include pre-processing, the use of fluorescent tracer particles instead of the red blood cells themselves as tracers give a more accurate prediction of the profile, and the use of silicone as the channel material more closely mimics the behavior of physiology. Acrylic biocompatible polymer channels are shown to give a more parabolic profile at lower levels of hematocrit, while silicone biocompatible polymer channels give a velocity profile that looks more like in vivo flow studies.
Cross-Sectional Measurement of Micro Particles Volume Fraction in a Microchannel by Using Capacitance Tomography Sensing
Authors: Othman Nur Tantiyani Ali , Obara Hiromichi , Choi Je-Eun , Takei Masahiro
Published: July 2013

In this study, a cross-sectional capacitance is measured in a microchannel with 12 multi-layered electrodes. The cross-sectional capacitance of polystyrene particles and deionized water is measured at upstream and downstream microchannel. Based on the measured cross-sectional capacitance, the particle volume fraction is calculated at three area measurements with different electrode pair. The three area measurements are at the adjacent pair, horizontal pair and vertical pair. The particle volume fraction at the adjacent pair area is almost same and higher at upstream and downstream cross-section. While at the vertical and horizontal pair areas, the particle volume fraction increased from upstream to downstream cross-section around 1.0–9.3% at electrode pair near the walls whilst decreased 0.4–0.96% at electrode pair near the center streamlines. It shows the particles are more attracted to migrate to the equilibrium position at near to the walls. The particles migration induced by inertial lift forces is reflected to Serge-Silberberg phenomenon where the particles are distributed and transverse from the center streamlines of fluid flowing to the area near the walls.