bluuebunny/crossref_metadata_2025 huggingface dataset:
Network biogeographical analysis of the central Aegean archipelago
Authors: Kougioumoutzis Konstantinos , Simaiakis Stylianos Michail , Tiniakou Argyro
Published: May 2014

Aim

Although the factors shaping plant species richness patterns across the islands of the central Aegean are well known, the processes driving the assembly of these island communities remain unclear. To shed light on these processes, we identified biogeographical modules within the phytogeographical area of the Cyclades and tested for nestedness across the islands.

Location

The Cyclades, Greece.

Methods

We used a network approach to detect island biogeographical roles and modules, based on a large and detailed database of the Greek endemic plant taxa of the Cyclades, and we tested for nestedness in the island–species matrices.

Results

The Cyclades were significantly modular and divided into five biogeographical modules. Three of the modules were significantly nested and two displayed all four possible biogeographical roles (connectors, module hubs, network hubs, peripherals). Most of the network's taxa are classified as peripherals and widespread endemics.

Main conclusions

The borders of the five modules correspond remarkably well to the palaeogeographical and climatic compartmentalization of the Cyclades. The flora of the Cyclades has not yet reached the relaxation phase and the region may act as an ecogeographical filter for the distribution of several plant lineages. Naxos, Milos and Anafi play an important role for the network's connectivity, while at least five adjacent phytogeographical regions affect the distribution patterns of the endemic taxa present in the Cyclades.
Sexual selection on Drosophila serrata male pheromones does not vary with female age or mating status
Authors: Gershman S. , Delcourt M. , Rundle H. D.
Published: May 2014

Mate preferences are costly and are thought to evolve due to the direct and/or indirect benefits they provide. Such costs and benefits may vary in response to intrinsic and extrinsic factors with important evolutionary consequences. Limited attention has been given to quantifying such variation and understanding its causes, most notably with respect to the direction and strength of preferences for multivariate sexual displays. In Drosophila serrata, female preferences target a pheromone blend of long‐chain cuticular hydrocarbons (CHCs). We used a factorial design to test whether female age and mating status generated variation in the strength and direction of sexual selection on male CHCs. Replicate choice mating trials were conducted using young and old females (4 or 10 days post‐emergence) that were either virgin or previously mated. The outcome of such trials is known to capture variation in female mate preferences, although male–male interactions may also contribute. Directional sexual selection on male CHCs was highly significant within each treatment, but there was little evidence of any variation among treatments. The absence of treatment effects implies that the multivariate combination of male CHCs preferred by females was constant with respect to female age and mating status. To the extent that male–male interactions may also contribute, our results similarly imply that these did not vary among treatments groups. With respect to D. serrata mate preferences, our results suggest that either plasticity with respect to age and mating status is not beneficial to females, or preference expression is somehow constrained.
Physicochemical Characterization of Seeds of Cabernet Sauvignon and Ives Grapes
Authors: Menezes Maraísa L. , Bracht Cissa K. , Ambrosio‐Ugri Miriam C.B. , Barros Sueli T.D. , Pereira Nehemias C.
Published: May 2014

This study aimed to analyze physical and chemical characteristics of seeds of Cabernet Sauvignon and Ives grape varieties. Some physical properties were determined: length, width, thickness, true density, bulk density, porosity, sphericity, angle of repose, particle grain size and specific heat of seeds of oven‐dried and fresh seeds. In addition, the proximate analysis and profile of minerals of fresh seeds were examined. Seeds after drying underwent a significant reduction in length and width, unlike the thickness, porosity and sphericity. Also, differences in particle grain size were verified, caused by the shrinkage of seeds due to drying. The angle of repose and the specific heat were found to be close to 30° and 1.5 J/gK. In proximate and mineral analysis, high values for fibers were observed, 45.76% and 47.89%, for Cabernet Sauvignon and Ives seeds, respectively, and high quantities of calcium and magnesium in both varieties.

Practical Applications

Currently, government requirements have led to increased costs for treating wastes generated by food industries, which increases the importance of developing technologies that allow its reuse. The pomace consisting of peel, seed and stalk is the primary waste generated by the processing of grapes, and is used as animal feed or as fertilizer in vineyards. The determination of physical and chemical properties of agricultural products is of great importance for the design of equipments for cleaning, classification, drying, storage and pneumatic conveying systems to obtain a higher yield during processing. Considering that studies on the processing of grape seeds are scarce, this study aimed to analyze and compare physical and chemical characteristics of seeds of Cabernet Sauvignon and Ives grape varieties, possibiliting their application by industries of seed oil extraction.
Assessment on Rheological and Texture Properties of Xylitol‐Substituted Dadih
Authors: Mohd Thani Nurfatimah , Mustapa Kamal Siti Mazlina , Taip Farah Saleena , Awang Biak Dayang Radiah
Published: May 2014

Dadih is a dairy‐based dessert made of milk, water, sugar and agar, which is popular especially among South East Asian people. It has sweet taste due to high sugar content in its formulation. An excessive intake of sugar is harmful to human health, and it would be beneficial if the conventional sugar is replaced by a sugar substitute. In order to formulate a healthier dadih, xylitol was used to replace sucrose in three different levels of compositions (0, 50 and 100%), which xylitol provides intense sweetness with fewer calories. Therefore, the objective of this study was to evaluate the effect of xylitol substitution on rheological and textural properties of xylitol‐substituted dadih. Process parameters were cooking temperatures (85–95C) and cooking times (10–20 min). It was found that cooking temperature had the biggest impact on dadih. All samples showed gel‐like behavior where the value of G′ (storage modulus) was higher than G″ (loss modulus). Samples that were prepared under high temperatures illustrated higher value of G′ with elastic gel property regardless of the xylitol composition. Sample prepared at 95C cooking temperature, 20‐min cooking time and 0% xylitol exhibited the highest value of hardness and internal gel strength with 0.892 N ± 0.002 and 0.248 N ± 0.006, respectively. In general, the presence of xylitol in dadih contributed to its softer texture compared to a product that is made from sucrose. However, xylitol‐substituted dadih prepared at 85C with longer cooking time (15 to 20 min) met the required texture as conventional dadih.

Practical Applications

Xylitol is currently one of most popular sugar replacement due to its abundance compensation to consumers' health. Thus, the study on the effect of xylitol substitution on different types of food can benefit the future of food industry. This research focused on finding the optimal xylitol substitution under different process conditions in dadih production. The rheological and texture analysis on samples with various process conditions and xylitol substitution confirmed that the physical properties of dadih are easily affected by these two factors. Physical properties of dadih have an important role in consumer's acceptability; hence, rheology and texture analysis are crucial to determine the physical properties of xylitol‐substituted dadih.
Effects of Selected Process Parameters on Physical and Sensorial Properties of Yellowfin Tuna (Thunnus albacares) Skin Gelatin
Authors: Karayannakidis Panayotis D. , Chatziantoniou Soumela E. , Zotos Anastasios
Published: May 2014

Four potential input variables, namely, acid concentration (0.01–0.1 mol/L), pretreatment time (1–3 h), extraction temperature (40–55C) and extraction time (1–6 h) were investigated to identify the key factors that affect gelatin yield and the physical (gel strength, viscosity and melting point) and sensorial (color, odor and overall liking) properties of gelatin produced from yellowfin tuna (Thunnus albacares) skins. For all processes employed, a preliminary two‐step alkaline pretreatment was applied using a 0.2 mol/L sodium hydroxide solution for 30 min for each step. Factorial analysis indicated that acid concentration, extraction temperature and time, as well as the interaction term extraction temperature × extraction time were significant for gelatin yield, while acid concentration and the interaction term acid concentration × extraction time were important for the physical properties of gelatin (P < 0.05). Sensorial properties were affected by acid concentration only (P < 0.05). Sum scores analysis revealed that the most suitable process for gelatin manufacture from yellowfin tuna skins comprises of the preliminary two‐step alkaline pretreatment, followed by an acidic pretreatment using a 0.1 mol/L acetic acid solution for 1 h and subsequently extracting gelatin with water at 55C for 6 h.

Practical Applications

Processing of yellowfin tuna (T. albacares) in the north central coastal region ofGreece generates large amounts of byproducts (e.g., skins, bones, heads, scales and viscera), which can account for up to 50% of the total fish weight. Despite the presence of several valuable components, such as protein and lipid, yellowfin tuna processing byproducts are usually being dumped into landfills or end up as low commercial value products (e.g., animal feed). Utilization of the aforementioned byproducts, especially of collagen‐rich fish skins, for the production of gelatin, will not only increase their commercial value, but will also satisfy the needs of the fish processing industries that face waste disposal problems.
Development and optimization of a non‐enzymatic method of leukocyte isolation from macaque tissues
Authors: Pereira Lara E. , Makarova Natalia , Dobard Charles , Aubert Rachael D. , Srinivasan Priya , McNicholl Janet , Smith James M.
Published: May 2014

Background and Methods

Cell isolation from macaque tissues involves laborious enzymatic digestion. The Medimachine provides a simpler, quicker non‐enzymatic method, yielding 1.5–5 million cells/g of vaginal or rectal tissue from pigtailed macaques.

Results and Conclusions

Flow cytometry analysis of the two methods revealed similar levels of cell viability and most major cell lineage and activation markers.
A Biocultural Perspective on Fictive Kinship in the Andes: Social Support and Women's Immune Function in El Alto, Bolivia
Authors: Hicks Kathryn
Published: May 2014

This article examines the influence of emotional and instrumental support on women's immune function, a biomarker of stress, in the city of El Alto, Bolivia. It tests the prediction that instrumental support is protective of immune function for women living in this marginal environment. Qualitative and quantitative ethnographic methods were employed to assess perceived emotional and instrumental support and common sources of support; multiple linear regression analysis was used to model the relationship between social support and antibodies to the Epstein‐Barr virus. These analyses provided no evidence that instrumental social support is related to women's health, but there is some evidence that emotional support from compadres helps protect immune function.
MorphogenesbolAandmreBmediate the photoregulation of cellular morphology during complementary chromatic acclimation inFremyella diplosiphon
Authors: Singh Shailendra P. , Montgomery Beronda L.
Published: May 2014

Photoregulation of pigmentation during complementary chromatic acclimation (CCA) is well studied inFremyella diplosiphon; however, mechanistic insights into theCCA‐associated morphological changes are still emerging.F. diplosiphoncells are rectangular under green light (GL), whereas cells are smaller and spherical under red light (RL). Here, we investigate the role of morphogenesbolAandmreBduringCCAusing gene expression and gene function analyses. TheF. diplosiphon bolAgene is essential as its complete removal from the genome was unsuccessful. Depletion ofbolAresulted in slow growth, morphological defects and the accumulation of high levels of reactive oxygen species in a partially segregated ΔbolAstrain. Higher expression ofbolAwas observed underRLand was correlated with lower expression ofmreBandmreCgenes in wild type. In a ΔrcaEstrain that lacks the red‐/green‐responsiveRcaEphotoreceptor, the expression ofbolAandmregenes was altered under bothRLandGL. Observed gene expression relationships suggest thatmreBandmreCexpression is controlled byRcaE‐dependent photoregulation ofbolAexpression. Expression ofF. diplosiphon bolAandmreBhomologues inEscherichia colidemonstrated functional conservation of the encoded proteins. Together, these studies establish roles forbolAandmreBinRcaE‐dependent regulation of cellular morphology.
NOS3 tagSNPs does not modify the chronic kidney disease progression in autosomal dominant polycystic kidney disease
Authors: Ramanathan Gnanasambandan , Periyasamy Soundararajan , Lakkakula Bhaskar VKS
Published: May 2014

Aim

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary and progressive renal disorder. It is also recognised as the most frequent genetic cause of chronic kidney diseases (CKD). In the present study, four tagging SNPs and two more well studied polymorphisms (Intron 4 VNTR and Glu298Asp) the NOS3 gene were investigated to unravel the potential modifier effect of NOS3 gene on the progression of CKD in ADPKD.

Methods

A total of 102 ADPKD patients and 106 controls were selected for the study. The tagSNPs and Glu298Asp polymorphisms were genotyped using FRET‐based KASPar method and intron‐4 VNTR by polymerase chain reaction electrophoresis. The genotypes and haplotypes in the controls and ADPKD subjects were analysed by χ2 tests and haploview software. Mantel‐Haenszel stratified and univariate analyses were performed to estimate the influence of different genotypes between different CKD stages and hypertension.

Results

The tagSNPs of NOS3 genotypes and haplotypes did not exhibit any significant differences between controls and ADPKD patients. The significant linkage disequilibrium was observed between the rs3918184 and rs2853796 by forming LD block. In univariate analysis, the age and family history of Diabetes mellitus (DM) showed significant association with advancement of CKD, but not with the eNOS polymorphisms.

Conclusions

Our data suggests that there is no evidence for the involvement of NOS3 tag SNPs in the progression to CKD in ADPKD patients. A systematic study using well validated functional SNPs is necessary to clarify the role of the NOS3 gene in the development of CKD in ADPKD.
Factors associated with nonadherence to antihypertensive medication
Authors: Cho Su‐Jin , Kim Jinhyun
Published: May 2014

Hypertension is one of the most serious health problems in Korea. The purpose of this paper is to identify factors associated with self‐reported nonadherence to an antihypertensive regimen. The data were obtained from the Korean Medical Panel 2008 and 2009 database, which were surveyed by the Korea Institute for Health and Social Affairs and National Health Insurance. We analyzed 5324 patients using multivariate logistic regression models. Self‐reported nonadherence was used as a dependent variable and demographic, socioeconomic, and health status were included as independent variables to investigate the associated factors. Among the patients who were diagnosed with hypertension, 13.2% did not take their medicine as prescribed. Age and education attainment level were statistically significant. Younger and lower educational attainment groups were less likely to adhere to medication regimens and showed a tendency not to take their medicine as prescribed. There were no statistically significant variables in terms of health status. Our findings suggest that nurses in clinical and community settings should pay more attention to hypertensive patients who are young and less educated.
Retrospective evaluation of antimicrobial prophylaxis in prevention of surgical site infection in the pediatric population
Authors: Shah Goonjan S. , Christensen Robert E. , Wagner Deborah S. , Pearce Bridget K. , Sweeney Jennifer , Tait Alan R.
Published: May 2014

Background and Objectives

Few studies have been conducted in pediatric patients evaluating efficacy of prophylactic antibiotics for prevention of surgical site infection (SSI). This retrospective study was undertaken to determine the effect of antibiotic prophylaxis in the prevention of SSI in children.

Methods

With IRB approval, our perioperative electronic clinical information database was queried. Pediatric patients (≤18 years) undergoing general surgery, cardiac surgery, and spinal surgery at Mott Children's Hospital from January 2000 to April 2010 were included. Demographics and preoperative data were obtained from the Centricity Intraoperative Database, and any episodes of SSI were obtained by review of the infection control records.

Results

A total 5023 pediatric patients underwent surgery from January 2000 to April 2010. The average age of the children in the sample was 4.16 ± 5.5 years, and of these, 57% were boys. Overall, 119 (2.37%) cases of SSI were identified. There were no associations between the various patient factors and the development of SSIs. Children for whom antibiotics were administered incorrectly had a 1.7‐fold increased risk of SSIs compared with children who received antibiotics within the recommended guidelines (P < 0.02). Children who received antibiotics were more likely to suffer an SSI compared with those who did not.

Conclusions

Proper administration of preoperative antibiotics in pediatric patients is one of the few modifiable and significant factors in prevention of SSI.
Pharmacokinetics of sufentanil administered with 0.2% ropivacaine as a continuous epidural infusion for postoperative pain relief in infants
Authors: Woloszczuk‐Gebicka Bogumila , Grabowski Tomasz , Borucka Beata , Karas‐Trzeciak Magdalena
Published: May 2014

Background and objectives

Our objective was to assess plasma sufentanil concentrations and postinfusion pharmacokinetics in infants receiving 0.2% ropivacaine with sufentanil as a continuous epidural infusion for postoperative pain relief.

Methods

With consent of local ethics committee and informed parental consent, 20 infants 3–36 months old (m.o.) (median 9.3 m.o., 9.0 [3.5–15] kg, ASA PS I/II) were enrolled. Epidural catheter was placed under general anesthesia in L3–L4, L4–L5, or L2–L3 interspace and threaded not farther than 4 cm into epidural space. After initial bolus of 0.2% ropivacaine, 0.5 ml·kg−1 and sufentanil 200 ng·kg−1, continuous infusion of 0.2% ropivacaine, 0.3 mg·kg−1·h−1 with sufentanil 112 ng·kg−1·h−1 was started. For the postoperative period, sufentanil dose was reduced to 37 ng·kg−1·h−1. Blood samples were drawn at the end of surgery, 24 h later, by the end of 2nd day of infusion and after 3, 6, and 18 h from the end of infusion.

Sufentanil was measured using liquid–liquid extraction (LLE) procedure and HPLC‐MS/MS method with LOQ = 5 pg·ml−1.

Results and conclusions

Elimination of sufentanil following epidural administration was very slow, with MRT = 28.25 [18.36–44.75] h and t1/2 MRT = 19.57 [12.72–31.01] h. In infants, during a long‐term infusion of sufentanil with ropivacaine, the opioid concentration in plasma increases during the postoperative infusion itself, then increases even further after discontinuation of the infusion, in some cases reaching the values consistent with a potential risk of respiratory depression. Meticulous monitoring of the infants' vital signs is therefore mandatory not only during the infusion, but also for several hours after its discontinuation.
RNAi‐based Bean golden mosaic virus‐resistant common bean (Embrapa 5.1) shows simple inheritance for both transgene and disease resistance
Authors: Faria Josias C. , Valdisser Paula A. M. R. , Nogueira Elsa O. P. L. , Aragão Francisco J. L.
Published: May 2014

Bean golden mosaic virus (BGMV) is the causal agent of bean golden mosaic of common beans. A transgenic bean line that has been developed based on RNA interference to silence the BGMV rep gene showed immunity to the virus. Crosses were done between the transgenic line and six bean cultivars followed by four backcrosses to the commercial cultivars ‘Pérola’ and ‘BRS Pontal’. The transgene locus was consistently inherited from the crosses analysed in a Mendelian fashion in the segregating populations. The disease resistance reaction co‐inherited with the transgene. Nevertheless, the expression of disease resistance displayed a dosage effect phenomenon in the F1 generation. The analysis of the homozygous near‐isogenic lines in field conditions, under high BGMV disease incidence, indicated that the transgenic lines were completely resistant. These results show the strength of the disease resistance obtained, the stability of the trait across generations and its usefulness in the management of a disease for which there is no reported Phaseolus germplasm with immunity.
Dynamic changes in volatile emissions of breeding burying beetles
Authors: Haberer Wolf , Steiger Sandra , Müller Josef K.
Published: May 2014

Burying beetles reproduce on small vertebrate carcasses by exhibiting elaborate biparental brood care. Partner recognition in breeding Nicrophorus species (Coleoptera: Silphidae) relies substantially on information encoded in cuticular hydrocarbon profiles. Until recently, it was unknown whether breeding burying beetles also produce volatile low molecular weight substances and, if so, which functions can be attributed to such volatiles. The present study reports a survey of the volatiles released by males and females of Nicrophorus vespilloides Herbst in nonbreeding status and at different stages of breeding. Headspace analyses are performed by using solid phase micro‐extraction fibres and gas chromatography–mass spectrometry. The volatiles released by nonbreeding males and females include phenolic compounds, alcohols, aldehydes and ketones and are quite similar in both sexes. With the onset of breeding, the volatile profiles of males and females become distinct, with a number of female‐specific compounds occurring. An analysis of the anal secretions reveals the presence of some of the compounds previously detected in the headspace analysis. The specific chemical properties suggest that some of the volatiles may function against competitors and parasites, such as bacteria, fungi, nematodes and arthropods at the carcass breeding resource. By contrast, the emission of 4‐methyl branched esters by the females closely parallels the emission of the terpenoid methyl geranate and they may function together as a complex signal by the females. Signalling traits associated with biparental care and specific constraints associated with the ephemeral nature of the breeding resource may explain the occurrence of both groups of compounds in the volatile profiles.
Effects of group size on aggregation against desiccation in woodlice (Isopoda:Oniscidea)
Authors: Broly Pierre , Devigne Laëtitia , Deneubourg Jean‐Louis , Devigne Cédric
Published: May 2014

Aggregation in terrestrial isopods, a behaviour that results in the formation of dense clusters, is readily accepted as a mechanism of resistance to desiccation. Thus, aggregation is considered to be an adaptation to terrestrial life in this fully terrestrial suborder of crustaceans. In the present study ofPorcellio scaberLatreille, a cosmopolitan species, individual water loss is investigated experimentally as a function of the size of the aggregates and, for the first time, over a large range of group sizes (groups of 1, 10, 20, 40, 60, 80 and 100 individuals). From the perspective of an isolated individual, aggregation behaviour is effective in reducing the rate of water loss whatever the group size, and reduces the individual water loss rate by more than half in large groups. However, the water loss rate of an individual follows a power law according to group size. Accordingly, if the addition of individuals to small groups strongly reduces the water losses per individual, adding individuals to large groups only slightly reduces the individual water losses. Thus, the successful reduction of the water loss rate by this aggregation behaviour is confirmed, although only up to a certain limit, particularly if the number of individuals per aggregate exceeds 50–60 under the experimental conditions used in the present study. Moreover, the individual surface area exposed to the air, as a function of group size, follows a similar pattern (i.e. a similar power law). Thus, a geometrical explanation is proposed for the nonlinear water losses in woodlice aggregates. These results are discussed in relation to the group sizes observed both in the laboratory and the field.
Inorganic carbon acquisition in the acid‐tolerant alga Chlorella kessleri
Authors: El‐Ansari Omar , Colman Brian
Published: May 2014

The ability of the freshwater alga, Chlorella kessleri, to maintain a carbon concentrating mechanism when grown at acid pH was investigated. The alga grows over the pH range 4.0–9.0 and was found to take up bicarbonate and CO2 actively when grown at pH 6.0. However, when grown at acid pH (below 5.5), it does not have active CO2 uptake. The acidotolerant species maintained an internal pH of 6.1–7.5 over the external pH range 4.5–7.5, thus the pH difference between the cell interior and the external medium was large enough to allow for the diffusive uptake of CO2 at acid external pH. Mass spectrometric monitoring of O2 and CO2 fluxes by suspensions of C. kessleri, grown at acid pH, and maintained at pH 7.5 showed that the rates of O2 evolution did not exceed those of CO2 uptake. The final CO2 compensation concentrations of 14.0–17.7 µM reached by photosynthetic cells were above the CO2 equilibrium concentration in the external medium, indicating a lack of active CO2 uptake at acid pH. Chlorella kessleri accumulated CO2 with internal concentrations that were 9.9, 18.7 and 22.7‐fold that of the external medium for cells grown, respectively, at pH 4.5, 5.0 and 5.5. The ability of C. kessleri cells to accumulate high intracellular concentrations of inorganic carbon at acid pH would provide a sufficiently high concentration of CO2 at the active site of Rubisco thus allowing the alga to maintain growth rates similar to those at alkaline pH.
Hemoperfusion for the Treatment of Poisoning: Technology, Determinants of Poison Clearance, and Application in Clinical Practice
Authors: Ghannoum Marc , Bouchard Josée , Nolin Thomas D. , Ouellet Georges , Roberts Darren M.
Published: May 2014

Hemoperfusion is an extracorporeal treatment based on adsorption, historically reserved for the treatment of acute poisonings. Its use was popularized in the 1970s after several in vitro and animal experiments had demonstrated its efficacy, and was even preferred over hemodialysis in the management of overdosed patients.

With the advent of new and more efficient dialytic modalities, hemoperfusion is now less frequently performed in the Western world. However, hemoperfusion still remains popular in developing countries. The present article reviews the technique of hemoperfusion, the factors influencing poison clearance through adsorption and its current applications.
Sailing Between Scylla and Charybdis: The High Serum K–Low Dialysate K Quandary
Authors: Labriola Laura , Jadoul Michel
Published: May 2014

In HD patients, the optimal choice of dialysate K concentration is of paramount importance. Recent large observational studies have documented an association between low dialysate K concentration (< 2 or even <3 mEq/L) and a higher risk of sudden death. In this review, we first briefly discuss the available data concerning the link between hypokalemia and negative outcomes in non‐CKD populations, especially after an acute myocardial infarction or in congestive heart failure. We next review the pathophysiology of the arrhythmogenic effect related to K fluxes during HD and discuss the dialytic strategies aiming at making potassium fall more gradual and thus at reducing the electrical disturbances triggered by the HD session. We conclude with practical recommendations regarding the optimal choice of K bath and the importance of more frequent monitoring of serum K in some clinical scenarios.
Mother‐child interaction is associated with neurocognitive outcome in extremely low gestational age children
Authors: Rahkonen Petri , Heinonen Kati , Pesonen Anu‐Katriina , Lano Aulikki , Autti Taina , Puosi Riina , Huhtala Ea , Andersson Sture , Metsäranta Marjo , Räikkönen Katri
Published: May 2014

Early mother‐child interaction is one of the factors suggested to have an impact on neurocognitive development of extremely low gestational age (ELGA) children. Our aim was to examine associations of mother‐child interaction with neurocognitive outcome, neurological impairments and neonatal brain injuries in ELGA children. A prospective study of 48 ELGA children, born before 28 gestational weeks (26.3 ± 1.2 weeks, birth weight 876 g ± 194 g), and 16 term controls. Brain MRI was performed at term‐equivalent age. At two years of corrected age, the mother‐child interaction was assessed in a structured play situation using the Erickson Scales and Mutually Responsive Orientation Scales. Neurocognitive outcome was assessed with Griffiths Mental Developmental Scales (GMDS) and Bayley Scales of Infant and Toddler Development ‐ Third Edition (BSID‐III) and with Hempel neurological examination. Among ELGA children, higher quality of dyadic relationship and maternal sensitivity, responsiveness, and supportiveness were associated with positive neurocognitive outcome measured both with GMDS and BSID‐III (adjusted p < 0.05). This association remained after adjusting for mother's educational level. Neurological impairments at two years, white matter or gray matter abnormalities in MRI at term‐equivalent age, and grade III‐IV intraventricular hemorrhage during the neonatal period were not associated with mother‐child interaction. This study emphasizes the importance of the quality of mother‐child interaction after extremely preterm birth for neurocognitive development. Neonatal brain injury and neurological impairments were not associated with worse parent‐child interaction after two years.
COX‐2, mPGES‐1 and EP2 receptor immunohistochemical expression in canine and feline malignant mammary tumours
Authors: Millanta F. , Asproni P. , Canale A. , Citi S. , Poli A.
Published: May 2014

Prostaglandin (PG) signalling is involved in human and animal cancer development. PG E2 (PGE2) tumour‐promoting activity has been confirmed and its production is controlled by Cyclooxygenase‐2 (COX‐2) and microsomal PGE synthase‐1 (mPGES‐1). Evidence suggests that mPGES‐1 and COX‐2 contribute to carcinogenesis through the EP2 receptor. The aim of our study was to detect by immunohistochemistry COX‐2, mPGES‐1 and EP2 receptor expression in canine (n = 46) and feline (n = 50) mammary tumours and in mammary non‐neoplastic tissues. COX‐2 positivity was observed in 83% canine and 81% feline mammary carcinomas, mPGES‐1 in 75% canine and 66% feline mammary carcinomas and the EP2 receptor expression was observed in 89% canine and 54% feline carcinomas. The frequency of COX‐2, EP2 receptor and mPGES‐1 expression was significantly higher in carcinomas than in non‐neoplastic tissues and adenomas. COX‐2, mPGES‐1 and EP2 receptor expression was strongly associated. These findings support a role of the COX‐2/PGE2 pathway in the pathogenesis of these tumours.
Atypical fibrosarcoma in the skin of a Roborovski hamster (Phodopus roborovskii)
Authors: Johnson James G. , Blair Robert , Brandão João , Tully Thomas N. , Gaunt Stephen D.
Published: May 2014

A 2.5‐year‐old intact male Roborovski hamster (Phodopus roborovskii) was presented with a large subcutaneous mass overlying the abdomen, affecting the animal's ambulation and access to different compartments of the cage through narrow tubing. Ultrasound examination delineated a well‐circumscribed mass in the subcutis of the caudoventral abdominal region. The mass was surgically excised and on cytologic examination showed, in a background of blood, a small population of individually arranged oval to spindle‐shaped cells that exhibited a moderate degree of anisokaryosis, coarsely stippled chromatin, one or more prominent nucleoli, and lightly basophilic well‐defined cytoplasmic processes. Histologically, the mass was composed of interlacing streams and bundles of pleomorphic spindle cells (ganglion‐like cells) with variable amounts of collagenous stroma. The neoplastic cells exhibited moderate features of malignancy. These cells stained intensely with vimentin, but not with any other markers, including antibodies to cytokeratin AE1/AE3, S100 protein, desmin, smooth muscle actin, synaptophysin, neurofilament, and androgen receptor. Based on histologic features, the mass was diagnosed as an atypical fibrosarcoma. This is the first report of an atypical fibrosarcoma in a Roborovski hamster and one of few reports of atypical fibrosarcoma in domesticated hamsters overall.
Spectral‐domain optical coherence tomography evaluation of the cornea, retina, and optic nerve in normal horses
Authors: Pinto Nelson I. , Gilger Brian C.
Published: May 2014

Purpose

To determine the feasibility of using a handheld spectral‐domain optical coherence tomography (SD‐OCT) instrument to characterize normal corneal, retinal, and optic nerve head anatomyin vivoin standing horses.

Methods

Clinically normal horses under sedation, palpebral nerve blockage, and pharmacologically induced mydriasis were imaged with aSD‐OCTinstrument (EnvisuSD‐OCT, Bioptigen, Inc., Morrisville,NC). Radial volumes from the cornea (axial, superior, inferior, nasal, and temporal), and rectangular volumes from the retina (dorsal, ventral, nasal, and temporal) and optic nerve head were acquired. Manual measurements of the corneal layers within the five regions, retinal and nerve fiber layer thickness in the four different regions adjacent to theONH, and vertical and horizontal axis of the optic nerve head (ONH) and optic cup (OC) were obtained using the same device.

Results

Total corneal thickness (mean ±SD) measurements were 800 ± 50, 937 ± 61, 956 ± 61, 912 ± 65, and 884 ± 68 μm for the axial, superior, inferior, nasal, and temporal regions, respectively. The highest total retinal and nerve fiber layer thickness (mean ±SD), at the level of theONH, was found nasally 459 ± 115 and 377 ± 116 μm, respectively, followed by the temporal, dorsal, and ventral quadrants. The dimensions of theONHandOC(mean ±SD) were 3.682 ± 0.276 and 2.175 ± 0.502 mm for the horizontal, and 3.012 ± 0.278 and 2.035 ± 0.488 mm for the vertical axis.

Conclusions

TheSD‐OCTinstrument employed in this study may be used on sedated horses and allows the acquisition of high‐resolution images, and thickness measurements involving the cornea, retina, and optic nerve.
Asymmetric Varus and Valgus Stability of the Anatomic Cadaver Knee and the Load Sharing Between Collateral Ligaments and Bearing Surfaces
Authors: Wang Xiaonan , Malik Aamer , Bartel Donald L. , Wickiewicz Thomas L. , Wright Timothy
Published: May 2014

Knee joint stability is important in maintaining normal joint motion during activities of daily living. Joint instability not only disrupts normal motion but also plays a crucial role in the initiation and progression of osteoarthritis. Our goal was to examine knee joint coronal plane stability under varus or valgus loading and to understand the relative contributions of the mechanisms that act to stabilize the knee in response to varus–valgus moments, namely, load distribution between the medial and lateral condyles and the ligaments. A robot testing system was used to determine joint stability in human cadaveric knees as described by the moment versus angular rotation behavior under varus and valgus loads at extension and at 30 deg and 90 deg of flexion. The anatomic knee joint was more stable in response to valgus than varus moments, and stability decreased with flexion angle. The primary mechanism for providing varus–valgus stability was the redistribution of the contact force on the articular surfaces from both condyles to a single condyle. Stretching of the collateral ligaments provided a secondary stabilizing mechanism after the lift-off of a condyle occurred. Compressive loads applied across the knee joint, such as would occur with the application of muscle forces, enhanced the ability of the articular surface to provide varus–valgus moment, and thus, helped stabilize the joint in the coronal plane. Coupled internal/external rotations and anteroposterior and medial–lateral translations were variable and in the case of the rotations were often as large as the varus–valgus rotations created by the applied moment.
Simulation of Movement in Three-Dimensional Musculoskeletal Human Lumbar Spine Using Directional Encoding-Based Neurocontrollers
Authors: Nasseroleslami Bahman , Vossoughi Gholamreza , Boroushaki Mehrdad , Parnianpour Mohamad
Published: May 2014

Despite development of accurate musculoskeletal models for human lumbar spine, the methods for prediction of muscle activity patterns in movements lack proper association with corresponding sensorimotor integrations. This paper uses the directional information of the Jacobian of the musculoskeletal system to orchestrate adaptive critic-based fuzzy neural controller modules for controlling a complex nonlinear redundant musculoskeletal system. The proposed controller is used to control a 3D 3-degree of freedom (DOF) musculoskeletal model of trunk, actuated by 18 muscles. The controller is capable of learning to control from sensory information, without relying on pre-assumed model parameters. Simulation results show satisfactory tracking of movements and the simulated muscle activation patterns conform to previous EMG experiments and optimization studies. The proposed controller can be used as a computationally inexpensive muscle activity generator to distinguish between neural and mechanical contributions to movement and for study of sensory versus motor origins of motor function and dysfunction in human spine.
Constitutive Relations for Pressure-Driven Stiffening in Poroelastic Tissues
Authors: Reeve Adam M. , Nash Martyn P. , Taberner Andrew J. , Nielsen Poul M. F.
Published: May 2014

Vascularized biological tissue has been shown to increase in stiffness with increased perfusion pressure. The interaction between blood in the vasculature and other tissue components can be modeled with a poroelastic, biphasic approach. The ability of this model to reproduce the pressure-driven stiffening behavior exhibited by some tissues depends on the choice of the mechanical constitutive relation, defined by the Helmholtz free energy density of the skeleton. We analyzed the behavior of a number of isotropic poroelastic constitutive relations by applying a swelling pressure, followed by homogeneous uniaxial or simple-shear deformation. Our results demonstrate that a strain-stiffening constitutive relation is required for a material to show pressure-driven stiffening, and that the strain-stiffening terms must be volume-dependent.
Efficient Inverse Isoparametric Mapping Algorithm for Whole-Body Computed Tomography Registration Using Deformations Predicted by Nonlinear Finite Element Modeling
Authors: Li Mao , Wittek Adam , Miller Karol
Published: May 2014

Biomechanical modeling methods can be used to predict deformations for medical image registration and particularly, they are very effective for whole-body computed tomography (CT) image registration because differences between the source and target images caused by complex articulated motions and soft tissues deformations are very large. The biomechanics-based image registration method needs to deform the source images using the deformation field predicted by finite element models (FEMs). In practice, the global and local coordinate systems are used in finite element analysis. This involves the transformation of coordinates from the global coordinate system to the local coordinate system when calculating the global coordinates of image voxels for warping images. In this paper, we present an efficient numerical inverse isoparametric mapping algorithm to calculate the local coordinates of arbitrary points within the eight-noded hexahedral finite element. Verification of the algorithm for a nonparallelepiped hexahedral element confirms its accuracy, fast convergence, and efficiency. The algorithm's application in warping of the whole-body CT using the deformation field predicted by means of a biomechanical FEM confirms its reliability in the context of whole-body CT registration.
Biomechanical Analysis of a New Carbon Fiber/Flax/Epoxy Bone Fracture Plate Shows Less Stress Shielding Compared to a Standard Clinical Metal Plate
Authors: Bagheri Zahra S. , Tavakkoli Avval Pouria , Bougherara Habiba , Aziz Mina S. R. , Schemitsch Emil H. , Zdero Radovan
Published: May 2014

Femur fracture at the tip of a total hip replacement (THR), commonly known as Vancouver B1 fracture, is mainly treated using rigid metallic bone plates which may result in “stress shielding” leading to bone resorption and implant loosening. To minimize stress shielding, a new carbon fiber (CF)/Flax/Epoxy composite plate has been developed and biomechanically compared to a standard clinical metal plate. For fatigue tests, experiments were done using six artificial femurs cyclically loaded through the femoral head in axial compression for four stages: Stage 1 (intact), stage 2 (after THR insertion), stage 3 (after plate fixation of a simulated Vancouver B1 femoral midshaft fracture gap), and stage 4 (after fracture gap healing). For fracture fixation, one group was fitted with the new CF/Flax/Epoxy plate (n = 3), whereas another group was repaired with a standard clinical metal plate (Zimmer, Warsaw, IN) (n = 3). In addition to axial stiffness measurements, infrared thermography technique was used to capture the femur and plate surface stresses during the testing. Moreover, finite element analysis (FEA) was performed to evaluate the composite plate's axial stiffness and surface stress field. Experimental results showed that the CF/Flax/Epoxy plated femur had comparable axial stiffness (fractured = 645 ± 67 N/mm; healed = 1731 ± 109 N/mm) to the metal-plated femur (fractured = 658 ± 69 N/mm; healed = 1751 ± 39 N/mm) (p = 1.00). However, the bone beneath the CF/Flax/Epoxy plate was the only area that had a significantly higher average surface stress (fractured = 2.10 ± 0.66 MPa; healed = 1.89 ± 0.39 MPa) compared to bone beneath the metal plate (fractured = 1.18 ± 0.93 MPa; healed = 0.71 ± 0.24 MPa) (p < 0.05). FEA bone surface stresses yielded peak of 13 MPa at distal epiphysis (stage 1), 16 MPa at distal epiphysis (stage 2), 85 MPa for composite and 129 MPa for metal-plated femurs at the vicinity of nearest screw just proximal to fracture (stage 3), 21 MPa for composite and 24 MPa for metal-plated femurs at the vicinity of screw farthest away distally from fracture (stage 4). These results confirm that the new CF/Flax/Epoxy material could be a potential candidate for bone fracture plate applications as it can simultaneously provide similar mechanical stiffness and lower stress shielding (i.e., higher bone stress) compared to a standard clinical metal bone plate.
Dynamic Optimization of Human Running With Analytical Gradients
Authors: Chung Hyun-Joon , Arora Jasbir S. , Abdel-Malek Karim , Xiang Yujiang
Published: May 2014

The optimization-based dynamic prediction of 3D human running motion is studied in this paper. A predictive dynamics method is used to formulate the running problem, and normal running is formulated as a symmetric and cyclic motion. Recursive Lagrangian dynamics with analytical gradients for all the constraints and objective function are incorporated in the optimization process. The dynamic effort is used as the performance measure, and the impulse at the foot strike is also included in the performance measure. The joint angle profiles and joint torque profiles are calculated for the full-body human model, and the ground reaction force (GRF) is determined. Several cause-and-effect cases are studied, and the formulation for upper-body yawing motion is proposed and simulated. Simulation results from this methodology show good correlation with experimental data obtained from human subjects and the existing literature.
Modeling of Cold Metal Transfer Spot Welding of AA6061-T6 Aluminum Alloy and Galvanized Mild Steel
Authors: Rao Zhenghua , Liu Jiangwei , Wang Pei-Chung , Li Yunxiao , Liao Shengming
Published: May 2014

In this article, a three-dimensional (3D) transient unified model is developed to simulate the transport phenomena during the cold metal transfer (CMT) spot welding process of 1 mm thick aluminum AA6061-T6 and 1 mm thick galvanized mild steel (i.e., AISI 1009). The events of the CMT process are simulated, including arc generation and evolution; up-and-down movement of electrode, droplet formation and dipping into the weld pool; weld pool dynamics; zinc evaporation, and zinc vapor diffusion in the arc. The effects of the gap between the two workpieces and effects of zinc vapor evaporated from the steel surface on CMT process are studied. The results show that the arc temperature, velocity, and pressure keep changing during the CMT process, which is related to the variations of welding current, arc length, and zinc evaporation. It is found that the zinc evaporation leads to the extremely high arc pressure and the upward flow of zinc vapor near the steel surface, which would induce the arc instability and provide the drag force for the droplet impingement. The presence of the gap between the two workpieces can improve the expansion of the arc plasma, resulting in the smaller arc pressure and the more intensive upward flow of zinc vapor from the steel surface. The phenomena observed in the experiment are in agreement with the modeling results.
Detailed Heat Transfer Distributions of Narrow Impingement Channels for Cast-In Turbine Airfoils
Authors: Terzis Alexandros , Ott Peter , von Wolfersdorf Jens , Weigand Bernhard , Cochet Magali
Published: May 2014

The current capabilities of the foundry industry allow the production of integrally cast turbine airfoils. Impingement cooling effectiveness can be then further increased due to the manufacturing feasibility of narrow impingement cavities in a double-wall configuration. This study examines experimentally, using the transient liquid crystal technique, the cooling performance of narrow cavities consisting of a single row of five impingement holes. Heat transfer coefficient distributions are obtained for all channel interior surfaces over a range of engine realistic Reynolds numbers varying between 10,900 and 85,900. Effects of streamwise jet-to-jet spacing (X/D), channel width (Y/D), jet-to-target plate distance (Z/D), and jet offset position (Δy∕D) from the channel centerline are investigated composing a test matrix of 22 different geometries. Additionally, the target plate and sidewalls heat transfer rates are successfully correlated within the experimental uncertainties providing an empirical heat transfer model for narrow impingement channels. The results indicate similarities with multijet impingement configurations; however, the achievable heat transfer level is about 20% lower compared to periodic multijet impingement correlations found in open literature.