2,127 research outputs found
Influence of hydroperiod on aquatic food-web structure and energy production in a floodplain wetland:implications for environmental flow management
Context: Environmental water is often used to manage floodplain wetlands that support many taxa, both terrestrial and aquatic. It is important to optimise the managed hydroperiod to maximise the provision of aquatically derived resources from wetlands. Aims: To test the hypothesis that increasing hydroperiod affects food-web structure and energy production in floodplain wetlands. Methods: Fatty acids and stable isotopes of Ī“13C and Ī“15N were used to define food-web structure, and estimate total energy production throughout a managed inundation event in a wetland in the northern Murray-Darling Basin. Key results: Food-web complexity increased with an increasing hydroperiod in line with predictable patterns of community assemblage development, before reducing sharply immediately prior to drying. Energy availability increased with an increasing hydroperiod and there was a strong correlation (Ļ = 0.669, P = 0.0001) between energy availability and fatty acid concentration, which was in turn related to patterns of taxon occurrence. Conclusions and implications: Hydroperiod exerts a strong influence on aquatic invertebrate community trophic dynamics and energy provision. Planned flows should support maturation and stabilisation of the invertebrate community to optimise energy provision to consumers.</p
Word-finding pauses in primary progressive aphasia (PPA): Effects of lexical category
Word-finding pauses are common in logopenic primary progressive aphasia (PPA-L). However, no previous research investigated the distribution of word-finding pauses in PPA or their specificity to PPA-L. We coded pauses preceding nouns and verbs in narrative speech samples from participants with PPA-L, agrammatic (PPA-G) and semantic PPA (PPA-S), and controls, hypothesizing that frequent word-finding pauses, if present, should match previously-observed lexical category deficits (noun deficits in PPA-L and PPA-S; verb deficits in PPA-G).The PPA-L group paused more frequently before nouns than verbs, whereas no other group exhibited lexical category effects, suggesting that frequent word-finding pauses are specific to PPA-L
Vacuum UV (VUV) Photo-Oxidation of Polyethersulfone (PES)
International need for water quality is placing a high demand on separation technology to develop advanced oxidative processes for polyethersulfone (PES) membranes to help improve water purification. Therefore, VUV photo-oxidation with a low pressure Ar plasma was studied to improve the hydrophilicity of PES by flowing oxygen over the surface during treatment. X-ray photoelectron spectroscopy (XPS) detected a decrease in the C at% (4.4 Ā± 1.7 at%), increase in O at% (3.7 Ā± 1.0 at%), and a constant S at% (5.4 Ā± 0.2 at%). Curve fitting of the XPS spectra showed a decrease in sp2 C-C aromatic group bonding, and an increase in C-O, C-S, O=C-OH, sulphonate (-SO3 ) and sulphate (-SO4 ) functional groups with treatment time. The water contact angle decreased from 71.9ā¦ for untreated PES down to a saturation level of 41.9ā¦ with treatment. Since scanning electron microscopy (SEM) showed no major changes in surface roughness, the increase in hydrophilicity was mainly due to oxidation of the surface. Washing the VUV photo-oxidized PES samples with water or ethanol increased the water contact angle saturation level up to 66ā¦ indicating the formation of a weak boundary layer
Randomized controlled trial of laparoscopic anterior 180Ā° partial versus posterior 270Ā° partial fundoplication.
Article first published online: 28 NOV 2013. This item is under embargo for a period of 12 months from the date of publication, in accordance with the publisher's policy.BACKGROUND:
Previous trials show good outcomes following anterior and posterior partial versus Nissen fundoplication for gastro-oesophageal reflux. However, it is unclear which partial fundoplication performs best. This study compared anterior 180Ā° versus posterior 270Ā° fundoplication.
METHODS:
At three hospitals, patients were randomized to anterior 180Ā° versus posterior 270Ā° partial fundoplication, and clinical outcomes were determined using a structured questionnaire at 3, 6 and 12 months. Heartburn, dysphagia and satisfaction were assessed using 0-10 analoue scales, and adverse outcomes and side effects were determined. Endoscopy, manometry and pH monitoring were performed 6 months after surgery.
RESULTS:
Forty-seven patients were randomized to anterior (n = 23) versus posterior (n = 24) fundoplication. Clinical outcomes for 93-98% of patients were available at each follow-up point. At 12 months, the mean heartburn score was higher following anterior fundoplication (2.7 versus 0.8, P = 0.045), although differences were not significant at earlier follow-up. Conversely, following posterior fundoplication, patients were less able to belch at 3 (56% versus 16%, P = 0.013) and 6 months (43% versus 9%, P = 0.017). No significant differences were demonstrated for dysphagia. Both groups had high rates of satisfaction with the outcome - 85% versus 86% satisfied at 12 months follow-up.
CONCLUSION:
Both partial fundoplications are effective treatments for gastro-oesophageal reflux. Posterior partial fundoplication is associated with less reflux symptoms offset by more side effects.Australian National Health & Medical Research Council
The Development and Validation of a Mental Toughness Scale for Adolescents
The present study examined the validity of a newly developed instrument, the Mental Toughness Scale for Adolescents (MTS-A), which examines the attributes of challenge, commitment, confidence (abilities and interpersonal) and control (life and emotion). The six factor model was supporting using Exploratory Factor Analysis (EFA, n = 373) and Confirmatory Factor Analysis (CFA, n = 372). In addition, the mental toughness attributes correlated with adolescentsā academic motivation and engagement (n = 439), well-being (depression and anxiety) (n = 279) and test anxiety (n = 279), indicating relations with a number of affective, cognitive and behavioural dispositions, and demonstrating relevance in education and potentially mental health contexts
Assessing The Impact Of Socioeconomic Status On Maternal And Cord Serum Omega-3 Polyunsaturated Fatty Acid Levels
Background: Omega-3 (n-3) polyunsaturated fatty acids (PUFAs) modulate inflammation throughout the lifespan and are essential in fetal growth and development. Previous studies have demonstrated that individuals with lower socioeconomic status (SES) may be at risk for low intake of n-3 PUFAs; however, no research has compared the concentrations of these nutrients present in maternal and cord serum between markers of SES.
Significance of Problem: Individuals with low serum levels of n-3 PUFAs may suffer from unfavorable birth and pregnancy outcomes. Therefore, it is important to identify populations who may have decreased serum levels of these nutrients in order to provide nutritional recommendations to optimize prenatal care.
Objective: The purpose of this study is to assess the relationship between markers of SES and levels of n-3 PUFAs in maternal and cord serum in a group of patients delivering at a Midwest Academic Medical Center.
Methods: An IRB-approved study enrolled mother-infant pairs (n=55) at the time of delivery for collection of maternal and cord serum samples. n-3 PUFA levels quantified included Eicosapentaenoic acid (EPA), Docosahexaenoic acid (DHA), and total n-3 PUFAs. Markers of SES include private vs public insurance, income ā¤150% of the poverty line vs \u3e150%, and college degree earners vs no college degree. Descriptive statistics were run for all variables. The Mann-Whitney U test was used to assess differences in n-3 PUFA levels between SES groups. A p\u3c0.05 was considered statistically significant.
Results: Median gestational age at delivery was 39.3 weeks in this cohort. Significantly higher nutrient levels were present in college-educated mothers vs less than college-educated mothers for maternal EPA (9.44 Āµg/mL vs 5.13 Āµg/mL, p=0.010), cord EPA (1.88 Āµg/mL vs 1.40 Āµg/mL, p=0.011), cord DHA (37.96 Āµg/mL vs 32.80 Āµg/mL, p=0.014), and total cord n-3 PUFAs (44.23 Āµg/mL vs 39.34 Āµg/mL, p=0.024). Median cord EPA levels were significantly higher in those with private insurance compared to public (1.79 Āµg/mL, 1.18 Āµg/mL, p=0.022). Additionally, median cord EPA levels were significantly higher in those \u3e150% the poverty line (1.79 Āµg/mL, 1.10 Āµg/mL, p=0.030). No other significant differences were observed between SES groups and n-3 PUFA levels.
Conclusion: Our findings suggest that individuals with lower SES may be at risk for lower serum levels of n-3 PUFAs in pregnancy, which could predispose them to adverse birth and pregnancy outcomes. Future studies should focus on replicating these results in a larger, more heterogeneous sample and should consider analyzing additional markers of SES.https://digitalcommons.unmc.edu/chri_forum/1051/thumbnail.jp
Prediction of Children\u27s Early Academic Adjustment from Their Temperament: The Moderating Role of Peer Temperament
The goal of the study was to examine whether target childrenās temperamental negative emotional expressivity (NEE) and effortful control in the fall of kindergarten predicted academic adjustment in the spring and whether a classmateās NEE and effortful control moderated these relations. Target childrenās NEE and effortful control were measured in the fall via multiple methods, academic adjustment was measured via reading and math standardized tests in the spring, and observations of engagement in the classroom were conducted throughout the year. In the fall, teachers nominated a peer with whom each target child spent the most time and rated that peerās temperament. Target children with high effortful control had high reading and math achievement (ps = .04 and \u3c .001, respectively), and children with low NEE increased in engagement during the year (p \u3c .001). Peersā temperament did not have a direct relation to target childrenās academic adjustment. Peersā NEE, however, moderated the relation between target childrenās effortful control, as well as NEE, and changes in engagement (ps = .03 and .05, respectively). Further, peersā effortful control moderated the relations between target childrenās NEE and reading and changes in engagement (ps = .02 and .04, respectively). In each case, target childrenās temperament predicted the outcome in expected directions more strongly when peers had low NEE or high effortful control. Results are discussed in terms of how childrenās temperamental qualities relate to academic adjustment, and how the relation between NEE and changes in engagement, in particular, depends on peersā temperament
Tocopherol Content of Maternal Breast Milk and Impact on Neonatal Growth
Background: Vitamin E is a fat-soluble nutrient consisting of Ī±-, Ī²-, Ī“-, and Ī³-tocopherol isoforms that has established effects on neonatal growth in utero. Higher maternal plasma tocopherol concentrations in pregnancy are associated with increased neonatal weight, length, and head circumference percentiles at birth. However, less is known about the impacts of tocopherols on post-natal growth. Since many neonates consume maternal breast milk as their post-natal nutrient source, it is important to understand the tocopherol content of breast milk and associations with neonatal growth.
Significance of Problem: Although the tocopherols demonstrate positive associations with neonatal growth in utero, the role of these breast-milk-derived nutrients on post-natal growth is unclear. Enhanced understanding of these relationships can help clinicians and mothers ensure ideal nutrition and growth in their neonates.
Hypothesis: We hypothesize there will be positive correlations between maternal breast milk tocopherol concentrations and post-natal growth parameters in neonates.
Experimental Design: Breast milk samples were collected from postpartum mothers (N=24) whose neonates were admitted to the neonatal intensive care unit (NICU) and analyzed for Ī±-, Ī“-, and Ī³-tocopherol concentrations using high performance liquid chromatography (HPLC). Neonatal anthropometric percentiles at 36 weeks corrected gestational age (CGA) and discharge were collected from the medical record. The Fenton growth chart was used for neonates born \u3c37 weeks CGA and the WHO growth chart for neonates born \u3e37 weeks CGA. Spearman correlations assessed the relationships between breast milk tocopherol concentrations and neonatal growth percentiles. A p-value \u3c0.05 was statistically significant.
Results: 70% of neonates were born preterm (median CGA=35.9 weeks). At 36 weeks CGA, median growth percentiles were 59.9 for weight, 68.4 for length, and 60.9 for head circumference. At discharge, median growth percentiles dropped to 33.6, 41.6, and 48.3, respectively. Breast milk concentrations of Ī±- and Ī³-tocopherol were significantly correlated to increased neonatal length percentile at 36 weeks CGA (both R=0.70, both p=0.016), with Ī³-tocopherol concentration also correlating with increased weight percentiles at 36 weeks CGA (R=0.62, p=0.033). There were no significant associations between breast milk tocopherol content and discharge growth percentiles.
Conclusions: This study demonstrates the potential role of increased maternal breast milk tocopherol content on post-natal growth at 36 weeks CGA for preterm neonates. Limitations of this study include a small sample size and variability among neonates in total breast milk consumption prior to reported growth measures. Future research should assess total breast milk intake in neonates and evaluate neonatal plasma tocopherol concentrations.https://digitalcommons.unmc.edu/chri_forum/1048/thumbnail.jp
Evaluation of Tocopherol Isoforms in Maternal Breast Milk and Their Relationship with Maternal Dietary Intake
Background: Vitamin E is an essential, fat-soluble nutrient with four isoforms: Ī±-, Ī²-, Ī“-, and Ī³-tocopherol. These isoforms differentially modulate inflammation and show variable associations with perinatal outcomes, such as preterm delivery and Apgar scores. However, little is known about the role of these isoforms on post-natal outcomes and their presence in maternal breast milk, a neonateās ideal nutrition source.
Significance of Problem: To analyze the role of tocopherols on post-natal growth and inflammation, it is critical to first assess their presence in maternal breast milk. Relating these measures to maternal dietary intake can advance our understanding of breast milk micronutrient composition and provide an avenue for counseling lactating mothers on the importance of maternal nutrition to ensure their neonateās health.
Experimental Design: Breast milk samples were collected from postpartum mothers (N=24) whose infants were admitted to the neonatal intensive care unit (NICU) and analyzed for Ī±-, Ī“-, and Ī³-tocopherol concentrations using high-performance liquid chromatography (HPLC). Maternal dietary intake was assessed using the Harvard Food Frequency Questionnaire. Median tocopherol concentrations and isoform proportions were generated for breast milk concentrations and intake values. Tocopherol intake adequacy was defined using the Institute of Medicineās recommendation of 19mg of Ī±-tocopherol daily. Mann-Whitney U-tests compared median breast milk tocopherol concentrations between intake adequate vs. deficient mothers and assessed for differences in isoform proportions between dietary intake and breast milk samples. A p-value \u3c0.05 was statistically significant.
Results: 63.6% of mothers had deficient tocopherol intake (median daily intake=15.3mg Ī±-tocopherol). Median concentrations of Ī±-, Ī“-, and Ī³-tocopherol (ug/L) in breast milk samples were 3866.5, 768.1, and 118.6, respectively. There were no significant differences in breast milk tocopherol concentrations between intake adequate vs. deficient mothers. For both dietary intake and breast milk, Ī±-tocopherol had the highest relative proportion (MBM=83%, intake=52%), followed by Ī³-tocopherol (MBM=14%, intake=39%) and Ī“-tocopherol (MBM=3% intake=8%). Proportions of Ī“- and Ī³-tocopherol were significantly higher in dietary intake compared to maternal breast milk (both p\u3c0.001).
Conclusions: This study highlights the prevalence of overall tocopherol intake deficiency and increased proportional consumption of Ī“- and Ī³-tocopherol among lactating mothers. It also suggests a mechanism for maintaining breast milk Ī±-tocopherol concentrations despite intake deficiency. Differences in the proportions of tocopherol isoforms between breast milk and intake measures further indicates that proportions of individual tocopherol isoforms in breast milk are influenced by factors other than dietary intake.https://digitalcommons.unmc.edu/chri_forum/1049/thumbnail.jp
Omega-3 and Omega-6 Polyunsaturated Fatty Acid Levels in Placental Tissue and Association With Maternal Dietary Intake
Background: Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs) are precursors to lipid mediators that modulate inflammation throughout the body. Derivatives of n-3 PUFAs have anti-inflammatory properties and promote growth and neurodevelopment in the fetus. Conversely, n-6 PUFA metabolites exert pro-inflammatory effects and may contribute to adverse pregnancy and birth outcomes. Studies have shown that maternal dietary intakes of n-3 and n-6 PUFAs are associated with their levels in maternal serum, but less is known about the association between PUFA intake and placental levels of these nutrients. A fetus must obtain essential PUFAs from their mother through the placenta, therefore it is important to ascertain how maternal diet may impact placental PUFAs. Understanding this relationship may help inform dietary recommendations in pregnancy.
Objective: The purpose of this study is to assess the relationship between dietary intake of n-3 and n-6 PUFAs and their levels in placental tissue.
Methods: An IRB-approved study enrolled 29 mother-infant pairs who were delivering at a Midwest Academic Medical Center. Placental tissue samples were obtained at delivery and levels of n-3 and n-6 PUFAs (including Eicosapentaenoic acid (EPA), Docosahexaenoic acid (DHA), Docosapentaenoic acid (DPA), a-Linolenic acid (ALA), Linoleic acid (LA), and Arachidonic acid (AA)) were quantified in each sample. The Harvard Food Frequency Questionnaire (FFQ) was used to assess maternal dietary intake of n-3 and n-6 PUFAs. Descriptive statistics were run for all variables. Spearman correlations were used to assess the relationships between dietary intake and placental PUFA levels. A p\u3c0.05 was considered statistically significant.
Results: Median gestational age at delivery was 39.7 weeks in this cohort. Significant positive correlations were observed between maternal EPA intake and levels of placental DHA (R=0.52, p\u3c0.01), total placental n-3 PUFAs (R=0.50, p\u3c0.01), and placental AA (R=0.38, p=0.046). Conversely, maternal EPA intake was negatively correlated with the ratio of placental n-6:n-3 PUFAs (R=-0.45, p=0.02). Maternal DHA intake demonstrated significant positive correlations with placental DHA (R=0.46, p=0.01) and total placental n-3 PUFAs (R=0.43, p=0.02). No significant associations were observed between n-6 PUFA intake and placental levels of n-3 or n-6 PUFAs.
Conclusion: Our findings suggest that maternal dietary intakes of EPA and DHA are correlated with n-3 and n-6 PUFA levels in the placenta. This information may help guide optimal dietary guidelines for n-3 PUFAs during pregnancy. A limitation to our study is the small sample size; thus, future studies should focus on replicating these results in a larger sample.https://digitalcommons.unmc.edu/chri_forum/1050/thumbnail.jp
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