bluuebunny/crossref_metadata_2025 huggingface dataset:
The Crucial Role of GATA-1 in CCR3 Gene Transcription: Modulated Balance by Multiple GATA Elements in the CCR3 Regulatory Region
Authors: Kim Byung Soo , Uhm Tae Gi , Lee Seol Kyoung , Lee Sin-Hwa , Kang Jin Hyun , Park Choon-Sik , Chung Il Yup
Published: November 2010

GATA-1, a zinc finger-containing transcription factor, regulates not only the differentiation of eosinophils but also the expression of many eosinophil-specific genes. In the current study, we dissected CCR3 gene expression at the molecular level using several cell types that express varying levels of GATA-1 and CCR3. Chromatin immunoprecipitation analysis revealed that GATA-1 preferentially bound to sequences in both exon 1 and its proximal intron 1. A reporter plasmid assay showed that constructs harboring exon 1 and/or intron 1 sequences retained transactivation activity, which was essentially proportional to cellular levels of endogenous GATA-1. Introduction of a dominant-negative GATA-1 or small interfering RNA of GATA-1 resulted in a decrease in transcription activity of the CCR3 reporter. Both point mutation and EMSA analyses demonstrated that although GATA-1 bound to virtually all seven putative GATA elements present in exon 1–intron 1, the first GATA site in exon 1 exhibited the highest binding affinity for GATA-1 and was solely responsible for GATA-1–mediated transactivation. The fourth and fifth GATA sites in exon 1, which were postulated previously to be a canonical double-GATA site for GATA-1–mediated transcription of eosinophil-specific genes, appeared to play an inhibitory role in transactivation, albeit with a high affinity for GATA-1. Furthermore, mutation of the seventh GATA site (present in intron 1) increased transcription, suggesting an inhibitory role. These data suggest that GATA-1 controls CCR3 transcription by interacting dynamically with the multiple GATA sites in the regulatory region of the CCR3 gene.
A Critical Role for Mast Cells and Mast Cell-Derived IL-6 in TLR2-Mediated Inhibition of Tumor Growth
Authors: Oldford Sharon A. , Haidl Ian D. , Howatt Mackenzie A. , Leiva Carlos A. , Johnston Brent , Marshall Jean S.
Published: November 2010

Several TLR agonists are effective in tumor immunotherapy, but their early innate mechanisms of action, particularly those of TLR2 agonists, are unclear. Mast cells are abundant surrounding solid tumors where they are often protumorigenic and enhance tumor angiogenesis. However, antitumor roles for mast cells have also been documented. The impact of mast cells may be dependent on their activation status and mediator release in different tumors. Using an orthotopic melanoma model in wild-type C57BL/6 and mast cell-deficient KitW-sh/W-sh mice and a complementary Matrigel–tumor model in C57BL/6 mice, mast cells were shown to be crucial for TLR2 agonist (Pam3CSK4)-induced tumor inhibition. Activation of TLR2 on mast cells reversed their well-documented protumorigenic role. Tumor growth inhibition after peritumoral administration of Pam3CSK4 was restored in KitW-sh/W-sh mice by local reconstitution with wild-type, but not TLR2-deficient, mast cells. Mast cells secrete multiple mediators after Pam3CSK4 activation, and in vivo mast cell reconstitution studies also revealed that tumor growth inhibition required mast cell-derived IL-6, but not TNF. Mast cell-mediated anticancer properties were multifaceted. Direct antitumor effects in vitro and decreased angiogenesis and recruitment of NK and T cells in vivo were observed. TLR2-activated mast cells also inhibited the growth of lung cancer cells in vivo. Unlike other immune cells, mast cells are relatively radioresistant making them attractive candidates for combined treatment modalities. This study has important implications for the design of immunotherapeutic strategies and reveals, to our knowledge, a novel mechanism of action for TLR2 agonists in vivo.
IL-22RA2 Associates with Multiple Sclerosis and Macrophage Effector Mechanisms in Experimental Neuroinflammation
Authors: Beyeen Amennai D. , Adzemovic Milena Z. , Öckinger Johan , Stridh Pernilla , Becanovic Kristina , Laaksonen Hannes , Lassmann Hans , Harris Robert A. , Hillert Jan , Alfredsson Lars , Celius Elisabeth G. , Harbo Hanne F. , Kockum Ingrid , Jagodic Maja , Olsson Tomas
Published: November 2010

Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the CNS. Recent advances in whole-genome screening tools have enabled discovery of several MS risk genes, the majority of which have known immune-related functions. However, disease heterogeneity and low tissue accessibility hinder functional studies of established MS risk genes. For this reason, the MS model experimental autoimmune encephalomyelitis (EAE) is often used to study neuroinflammatory disease mechanisms. In this study, we performed high-resolution linkage analysis in a rat advanced intercross line to identify an EAE-regulating quantitative trait locus, Eae29, on rat chromosome 1. Eae29 alleles from the resistant strain both conferred milder EAE and lower production of proinflammatory molecules in macrophages, as demonstrated by the congenic line, DA.PVG-Eae29 (Dc1P). The soluble IL-22R α2 gene (Il-22ra2) lies within the Eae29 locus, and its expression was reduced in Dc1P, both in activated macrophages and splenocytes from immunized rats. Moreover, a single nucleotide polymorphism located at the end of IL-22RA2 associated with MS risk in a combined Swedish and Norwegian cohort comprising 5019 subjects, displaying an odds ratio of 1.26 (p = 8.0 × 10−4). IL-22 and its receptors have been implicated in chronic inflammation, suggesting that IL-22RA2 regulates a central immune pathway. Through a combined approach including genetic and immunological investigation in an animal model and large-scale association studies of MS patients, we establish IL-22RA2 as an MS risk gene.
Influenza Epitope-Specific CD8+ T Cell Avidity, but Not Cytokine Polyfunctionality, Can Be Determined by TCRβ Clonotype
Authors: Moffat Jessica M. , Handel Andreas , Doherty Peter C. , Turner Stephen J. , Thomas Paul G. , La Gruta Nicole L.
Published: November 2010

Cytokine polyfunctionality has recently emerged as a correlate of effective CTL immunity to viruses and tumors. Although the determinants of polyfunctionality remain unclear, there are published instances of a link between the production of multiple effector molecules and the peptide plus MHC class I molecule avidity of T cell populations. Influenza A virus infection of C57BL/6J mice induces CTL populations specific for multiple viral epitopes, each with varying proportions of monofunctional (IFN-γ+ only) or polyfunctional (IFN-γ+TNF-α+IL-2+) CTLs. In this study, we probe the link between TCR avidity and polyfunctionality for two dominant influenza epitopes (DbNP366 and DbPA224) by sequencing the TCR CDR3β regions of influenza-specific IFN-γ+ versus IFN-γ+IL-2+ cells, or total tetramer+ versus high-avidity CTLs (as defined by the peptide plus MHC class I molecule-TCR dissociation rate). Preferential selection for particular clonotypes was evident for the high-avidity DbPA224-specific set but not for any of the other subsets examined. These data suggest that factors other than TCRβ sequence influence cytokine profiles and demonstrate no link between differential avidity and polyfunctionality.
Lipopolysaccharide-Mediated IL-10 Transcriptional Regulation Requires Sequential Induction of Type I IFNs and IL-27 in Macrophages
Authors: Iyer Shankar Subramanian , Ghaffari Amir Ali , Cheng Genhong
Published: November 2010

IL-10 is a potent anti-inflammatory molecule that regulates excessive production of inflammatory cytokines during an infection or tissue damage. Dysregulation of IL-10 is associated with a number of autoimmune diseases, and so, understanding the mechanisms by which IL-10 gene expression is regulated remains an important area of study. Macrophages represent a major source of IL-10, which is generated in response to TLR signaling as a feedback mechanism to curtail inflammatory response. In this study, we identify a signaling pathway in murine bone marrow-derived macrophages in which activation of TLR4 by LPS induces the expression of IL-10 through the sequential induction of type I IFNs followed by induction and signaling through IL-27. We demonstrate that IL-27 signaling is required for robust IL-10 induction by LPS and type I IFNs. IL-27 leads directly to transcription of IL-10 through the activation of two required transcription factors, STAT1 and STAT3, which are recruited to the IL-10 promoter. Finally, through systematic functional promoter-reporter analysis, we identify three cis elements within the proximal IL-10 promoter that play an important role in regulating transcription of IL-10 in response to IL-27.
Early Enhanced Local Neutrophil Recruitment in Peritonitis-Induced Sepsis Improves Bacterial Clearance and Survival
Authors: Craciun Florin L. , Schuller Elizabeth R. , Remick Daniel G.
Published: November 2010

Neutrophils are critical for the rapid eradication of bacterial pathogens, but they also contribute to the development of multiple organ failure in sepsis. We hypothesized that increasing early recruitment of neutrophils to the focus of infection will increase bacterial clearance and improve survival. Sepsis was induced in mice, using cecal ligation and puncture (CLP); blood samples were collected at 6 and 24 h; and survival was followed for 28 d. In separate experiments, peritoneal bacteria and inflammatory cells were measured. Septic mice predicted to die based on IL-6 levels (Die-P) had higher concentrations of CXCL1 and CXCL2 in the peritoneum and plasma compared with those predicted to live (Live-P). At 6 h, Live-P and Die-P had equivalent numbers of peritoneal neutrophils and bacteria. In Die-P mice the number of peritoneal bacteria increased between 6 and 24 h post-CLP, whereas in Live-P it decreased. The i.p. injection of CXCL1 and CXCL2 in naive mice resulted in local neutrophil recruitment. When given immediately after CLP, CXC chemokines increased peritoneal neutrophil recruitment at 6 h after CLP. This early increase in neutrophils induced by exogenous chemokines resulted in significantly fewer peritoneal bacteria by 24 h [CFU (log) = 6.04 versus 4.99 for vehicle versus chemokine treatment; p < 0.05]. Chemokine treatment significantly improved survival at both 5 d (40 versus 72%) and 28 d (27 versus 52%; p < 0.02 vehicle versus chemokines). These data demonstrate that early, local treatment with CXC chemokines enhances neutrophil recruitment and clearance of bacteria as well as improves survival in the CLP model of sepsis.
Robust Vaccine-Elicited Cellular Immune Responses in Breast Milk following Systemic Simian Immunodeficiency Virus DNA Prime and Live Virus Vector Boost Vaccination of Lactating Rhesus Monkeys
Authors: Wilks Andrew B. , Christian Elizabeth C. , Seaman Michael S. , Sircar Piya , Carville Angela , Gomez Carmen E. , Esteban Mariano , Pantaleo Giuseppe , Barouch Dan H. , Letvin Norman L. , Permar Sallie R.
Published: November 2010

Breast milk transmission of HIV remains an important mode of infant HIV acquisition. Enhancement of mucosal HIV-specific immune responses in milk of HIV-infected mothers through vaccination may reduce milk virus load or protect against virus transmission in the infant gastrointestinal tract. However, the ability of HIV/SIV strategies to induce virus-specific immune responses in milk has not been studied. In this study, five uninfected, hormone-induced lactating, Mamu A*01+ female rhesus monkey were systemically primed and boosted with rDNA and the attenuated poxvirus vector, NYVAC, containing the SIVmac239 gag-pol and envelope genes. The monkeys were boosted a second time with a recombinant Adenovirus serotype 5 vector containing matching immunogens. The vaccine-elicited immunodominant epitope-specific CD8+ T lymphocyte response in milk was of similar or greater magnitude than that in blood and the vaginal tract but higher than that in the colon. Furthermore, the vaccine-elicited SIV Gag-specific CD4+ and CD8+ T lymphocyte polyfunctional cytokine responses were more robust in milk than in blood after each virus vector boost. Finally, SIV envelope-specific IgG responses were detected in milk of all monkeys after vaccination, whereas an SIV envelope-specific IgA response was only detected in one vaccinated monkey. Importantly, only limited and transient increases in the proportion of activated or CCR5-expressing CD4+ T lymphocytes in milk occurred after vaccination. Therefore, systemic DNA prime and virus vector boost of lactating rhesus monkeys elicits potent virus-specific cellular and humoral immune responses in milk and may warrant further investigation as a strategy to impede breast milk transmission of HIV.
A comparison of obstetrics and perinatal outcomes of teenagers and older women: Experiences from rural South Africa
Authors: Hoque Monjurul , Hoque Shahnaz
Published: November 2010

Background: Teenage pregnancy is a known risk factor for a negative pregnancy outcome and poses a health risk to teenagers; it is thus considered a public health problem. It is also an indicator of problems with the sexual and reproductive health of a country’s young population. In South Africa, most of the adolescent pregnancies are to be found within the context of unstable relationships with the father of the baby and are unplanned or unwanted.Objectives: This study estimates and compares the incidence of adverse obstetric and perinatal outcomes of teenage women with older women, to identify specific health needs of teenage mothers during pregnancy and delivery.Methods:A retrospective cohort study targeted pregnant women who delivered at Empangeni Hospital from April to December 2005, whilst comparing the obstetric and perinatal outcomes of all teenage (ages < 19 years) pregnant women with those of older pregnant women (ages ≥ 19 years) for this study period. Data were collected from the labour ward delivery registry. Pearson’s chi-square test was performed to measure the level of significance (alpha = 0.05) for association amongst variables. The student t-test was used to find the significance difference between two proportions and the binary logistic regression method was employed to find the significant predictor for outcome variables.Results:There were 7836 deliveries over the study period, of which 1236 (16%) were teenage mothers.The rate of gestational age at delivery (e.g. pre-term delivery of 12%), vaginal and forceps deliveries,foetal presentation at birth, multiple pregnancies, low birth-weight and live births deliveries and mean Apgar scores were similar for both groups. The caesarean delivery rate (20%) and macerated stillbirth rate (1.1%) were significantly lower (p < 0.05) for teenagers than for older women.Conclusion: Although there was a higher rate of teenage pregnancy, it did not appear that it was associated with extra perinatal negative outcome such as preterm delivery, low birth-weight delivery and stillbirth. However, strategies are urgently needed to delay conception and improve the socio-economic development of teenage girls.
Acute Bipolar Depression: A Review of the Use of Olanzapine/Fluoxetine
Authors: Bobo William V. , Epstein Richard A. , Shelton Richard C.
Published: November 2010

Depression is the predominant mood state in patients with bipolar I or II disorder over the course of illness. In spite of this, relatively few pharmacological treatments have been shown to be effective for treating depressive episodes associated with bipolar disorder in adults. Combination therapy with olanzapine and fluoxetine (OFC) is approved in the US for the treatment of acute depressive episodes in adults with bipolar I disorder. The short-term efficacy and safety of OFC for the treatment of bipolar depression are supported by results of four randomized, acute-phase studies. OFC has been associated with significantly greater depressive symptom improvement than placebo, and with higher rates of treatment response and remission than placebo and olanzapine monotherapy. OFC has also been shown to improve depressive symptoms to a greater degree than modestly dosed lamotrigine, with similar rates of positive treatment response and remission. Although OFC was generally well tolerated in each of the reviewed studies, clinically significant weight gain, adverse changes in glycemic and lipid profile, and prolactin elevation may complicate both short- and long-term treatment. OFC was not associated with significantly increased risk of treatment-emergent mania in any of the reviewed studies. The broader effectiveness of OFC for the treatment of bipolar depression across clinically relevant subtypes (eg, patients with bipolar II disorder and comorbid substance abuse) and over long-term follow-up are needed. Comparative effectiveness studies of OFC and other available agents are also needed in order to determine its place among other available options for treating acute bipolar depressive episodes.
ESTs from Seeds to Assist the Selective Breeding of Jatropha curcas L. for Oil and Active Compounds
Authors: Gomes Kleber A. , Almeida Tiago C. , Gesteira Abelmon S. , Lôbo Ivon P. , Guimarães Ana Carolina R. , de Miranda Antonio B. , Van Sluys Marie-Anne , Da Cruz Rosenira S. , Cascardo Júlio C.M. , Carels Nicolas
Published: November 2010

We report here on the characterization of a cDNA library from seeds of Jatropha curcas L. at three stages of fruit maturation before yellowing. We sequenced a total of 2200 clones and obtained a set of 931 non-redundant sequences (unigenes) after trimming and quality control, ie, 140 contigs and 791 singlets with PHRED quality >10. We found low levels of sequence redundancy and extensive metabolic coverage by homology comparison to GO. After comparison of 5841 non-redundant ESTs from a total of 13193 reads from GenBank with KEGG, we identified tags with nucleotide variations among J. curcas accessions for genes of fatty acid, terpene, alkaloid, quinone and hormone pathways of biosynthesis. More specifically, the expression level of four genes (palmitoyl-acyl carrier protein thioesterase, 3-ketoacyl-CoA thiolase B, lysophosphatidic acid acyltransferase and geranyl pyrophosphate synthase) measured by real-time PCR proved to be significantly different between leaves and fruits. Since the nucleotide polymorphism of these tags is associated to higher level of gene expression in fruits compared to leaves, we propose this approach to speed up the search for quantitative traits in selective breeding of J. curcas. We also discuss its potential utility for the selective breeding of economically important traits in J. curcas.
Effects of cinnamaldehyde, eugenol, and capsicum on fermentation of a corn-based dairy ration in continuous culture
Authors: Tager L R , Krause K M
Published: November 2010

A 12-unit continuous culture system was used in a complete randomized design to study the effects of no oil (CON), cinnamaldehyde oil (CIN), eugenol oil (EUG), and capsicum oil (CAP) (500 mg L-1 d -1) with a 45:55 forage:concentrate ratio (dry matter basis) ration on rumen fermentation. Dry matter digestibility did not differ among treatments. Organic matter digestibility tended to decrease with CIN. Digestibility of neutral detergent and acid detergent fiber tended to be highest with CAP. Crude protein digestibility and bacterial nitrogen flow was depressed with CIN and EUG. CIN tended to decrease microbial protein synthesis and increase effluent ammonia nitrogen. Total volatile fatty acid production did not differ among treatments; however, isovalerate production tended to be highest with CAP. CIN and EUG had higher mean pH, spent fewer hours per day and had smaller area under the curve at pH < 5.6 and 5.8. CAP had smaller area under the curve at pH < 5.6. Supplementation with these oils at the current dose had limited effects on rumen fermentation, with the majority of effects observed being mainly attributable to the very high dosage of oil used. Key words: Dairy cow, essential oil, continuous culture, rumen fermentation, rumen pH
Impact of an extended photoperiod in farrowing houses on the performance and behaviour of sows and their litters
Authors: Lachance M P , Laforest J P , Devillers N. , Laperrière A. , Farmer C.
Published: November 2010

The effects of an extended photoperiod around parturition and throughout lactation on performances of primiparous sows and their piglets were studied. Sows were assigned to two light regimens: (1) standard (CTL, n = 28), 8 h of daily light from day 112 of gestation until day 23 of lactation; and (2) extended (TRT, n = 26), 23 h of daily light from day 112 of gestation to day 4 of lactation and 16 h thereafter. Colostrum intake was estimated based on a 24-h piglet weight gain starting at the end of farrowing. Piglets were weighed on days 4, 7, 14, 21 (weaning on day 23), 35 and 56. On days 4 and 21 of lactation, milk and blood samples were obtained. Behaviour was recorded on days 3 and 20. Piglet feed intakes were noted post-weaning until day 56. The TRT sows had lower concentrations of melatonin than the CTL sows on day 4 (P < 0.05), but prolactin concentrations, milk composition and colostrum intake by piglets were unaffected by treatment (P > 0.1). Litter growth during lactation was unaffected (P > 0.1), but TRT piglets consumed less feed between 23 and 34 d of age (P < 0.05) and weighed less on day 35 (P < 0.05). The TRT piglets were more active than CTL piglets on day 3 of lactation only (P < 0.05). Increasing the period of daily light in the farrowing house did not improve the performance of primiparous sows and their piglets. Key words: Behaviour, growth, lactation, photoperiod, piglet, sow
Review: Grazing preferences in sheep and cattle: Implications for production, the environment and animal welfare
Authors: Rutter S M
Published: November 2010

The evolutionary and domestic ancestors of sheep and cattle will have evolved diet selection behaviours that enabled them to select a diet that met their individual nutrient requirements whilst minimising the risk of being killed through predation or by eating toxins. Modern intensive farming generally involves grazing monocultures or feeding total mixed rations and these restrict the ability of livestock to select their own diet. Research has shown that grazing sheep and cattle have a partial preference of approximately 70% for clover (when offered as a monoculture sward alongside grass), and they show a consistent diurnal pattern of preference. Dairy cattle and sheep that are given the ability to select their own diet show higher levels of production than animals grazing mixed swards. There is some evidence that animals that can select their own diet are optimising their own efficiency of nutrient capture, and this potential environmental benefit warrants further research. Further research is also needed to establish if dairy cattle “need” to graze or whether they prefer to eat prepared rations indoors. Preventing animals from expressing their innate diet preferences by feeding them mixed rations may cause frustration and so compromise animal welfare, although this hypothesis requires further research.Key words: Grazing, ruminant, preference, choice, behaviour, welfare
Greater milk yield is related to increased DNA and RNA content but not to mRNA abundance of selected genes in sow mammary tissue
Authors: Farmer C. , Palin M -F , Hovey R C
Published: November 2010

The relationship between greater sow milk yield and mammary development, expression of selected genes in mammary tissue and hormonal concentrations in lactating sows was studied. Crossbred sows were separated in two groups according to the weight gains of their piglets up to day 21. The groups were: (1) lower milk yield (LOW, n = 14) and (2) higher milk yield (HI, n = 14), representing lactation weight gains of 4.46 and 5.25 kg pig-1, respectively. Jugular blood samples were obtained from all sows on day 3 (for prolactin determination) and day 23 (for measures of prolactin, leptin, insulin, glucose and free fatty acids) of lactation, and milk samples were collected on days 3 and 22. At weaning (day 23), sows were slaughtered and their mammary glands were collected, dissected and composition was determined. Mammary parenchymal tissue was analyzed for the mRNA abundance of selected genes. Hormone concentrations in blood did not differ between groups (P > 0.1) and on day 3 of lactation, dry matter and leptin contents in milk were lower (P < 0.05) in HI than in LOW sows. There was more DNA and RNA per teat in HI than LOW sows (P < 0.05), whereas the expression of selected genes within mammary tissue was unaffected (P > 0.1) by production group. Significant correlations (P < 0.01) existed between average weight gain of piglets during lactation and mammary RNA and DNA, expressed either as total amount or amount per teat, at weaning. Sow milk yield is therefore related to mammary gland composition in late lactation.Key words: Genes, lactation, mammary gland, milk yield, sow
Sex determination in ostrich (Struthio camelus) using DNA markers
Authors: Alipanah M. , Torkamanzehi A. , Taghavi H.
Published: November 2010

Production of bird species such as ostrich (Struthio camelus) has been gaining increasing importance in Iran as well as many other countries. Ostrich, similar to many other species of birds, lacks sexual dimorphism, making it difficult to differentiate between males and females, especially at an early age, which can be problematic in breeding programs. Recently developed molecular genetic methods that utilize polymerase chain reaction (PCR) based techniques can facilitate rapid identification of the bird’s sex in these species using a DNA sample, which can be easily extracted from blood or feather pulps. We successfully applied a PCR-based RFLP technique and sex chromosome primers for sex determination in a sample of 30 Ostrich chicks using DNA extracted from blood and feather pulps. Both DNA samples (blood and feather pulps) provided useful results. However, using feather pulps from 1-day-old chicks can provide an easy and inexpensive method for sex determination in ostrich. Key words: Ostrich (struthio camelus), sex determination, sexual dimorphism, polymerase chain reaction, RFLP
Review: Feeding behaviour of dairy cattle: Meaures and applications
Authors: von Keyserlingk M A.G. , Weary D M
Published: November 2010

There is growing scientific interest in feeding behaviour of dairy cattle, in part because dairy nutritionists are now becoming interested in how changes in feed intake are mediated by changes in behaviour and, in part, because changes in feeding behaviour are increasingly recognized as useful indicator of cow health. In this review we describe key methodological approaches to the study of feeding behaviour in dairy cattle. We also review empirical work addressing how changes in management and housing can affect this behaviour. We show how cows divide their daily intake into several discrete feeding events made up of a number of visits or “meals” that are separated by longer periods with little feeding activity. Feeding behaviour can be described using several measures, including the number and duration of meals, as well as intake and feeding rate. Feeding behaviour within a group of intensively managed cows is often highly synchronized, similar to that seen in extensively housed cattle, with delivery of fresh feed appearing to be the primary factor stimulating feeding by housed dairy cows. Competition at the feed bunk can affect feeding behaviour, increasing the feeding rate and reducing intake, especially for subordinate animals. We also review empirical work showing that feed intake, feeding times, and feeding rate are altered when cows are ill. Feeding behaviour changes in the days before calving, and these changes are greatest among cows at greatest risk of succumbing to disease in the early post partum period. These results suggest that monitoring changes in feeding behaviour may be useful in early detection and prevention of disease in transition cows.Key words: Dairy cattle, feeding behaviour, management, health
Analysis of genetic diversity in four Canadian swine breeds using pedigree data
Authors: Melka M G , Schenkel F.
Published: November 2010

Conservation of animal genetic resources entails judicious assessment of genetic diversity as a first step. The objective of this study was to analyze the trend of within-breed genetic diversity and identify major causes of loss of genetic diversity in four swine breeds based on pedigree data. Pedigree files from Duroc (DC), Hampshire (HP), Lacombe (LC) and Landrace (LR) containing 480 191, 114 871, 51 397 and 1 080 144 records, respectively, were analyzed. Pedigree completeness, quality and depth were determined. Several parameters derived from the in-depth pedigree analyses were used to measure trends and current levels of genetic diversity. Pedigree completeness indexes of the four breeds were 90.4, 52.7, 89.6 and 96.1%, respectively. The estimated percentage of genetic diversity lost within each breed over the last three decades was approximately 3, 22, 12 and 2%, respectively. The relative proportion of genetic diversity lost due to random genetic drift in DC, HP, LC and LR was 74.5, 63.6, 72.9 and 60.0%, respectively. The estimated current effective population size for DC, HP, LC and LR was 72, 14, 36 and 125, respectively. Therefore, HP and LC have been found to have lost considerable genetic diversity, demanding priority for conservation. Key words: Genetic drift, effective population size
Determination of the optimum slaughter weight to maximize gross profit in a turkey production system
Authors: Case L A , Miller S P , Wood B J
Published: November 2010

A deterministic model was used to optimize turkey slaughter weight based on a profit equation that described the commercial grower and processing divisions of an integrated company. The objective was to determine optimum slaughter weights for toms and hens using both a heavy and super heavy strain, to maximize gross margin of the system. Sensitivity of optimum slaughter weight in response to feed cost and breast meat price was also considered. Higher margins could be achieved with toms and super heavy strain birds. This indicated that larger birds, from a heavier weight strain or toms within a strain, could be more efficient and profitable given the assumed production values. Results were based on the assumed market conditions, and changes in the costs or turkey component values (i.e., breast meat) could result in a shift in the optimal turkey strain to use. Increased feed cost results in a lower optimum slaughter weight and decreased margin. Optimum slaughter weight and profit increased with higher breast meat values. Increasing the profit of an integrated company can be accomplished by targeting slaughter to an optimum weight.Key words: Turkey, body weight, production efficiency, breast meat, feed efficiency
Identifying appropriate methodology to diagnose aeration limitations with large peat and bark particles in growing media
Authors: Caron J. , Morel P. , Rivière L -M. , Guillemain G.
Published: November 2010

Large-sized particles (coarse peat, bark or sawdust) are often added to growing media to improve substrate aeration properties (gas storage and exchange). Recent studies have shown that large fragments mixed with fines may create barriers that restrict gas diffusion or create competition for oxygen even if they improve air storage. An experiment was carried out to compare the growth performances of growing media containing large fragments and to assess their aeration status using different methods. Different mixes were made of a fine sphagnum peat (average size 2.4 mm) and a coarse (1-2, 2-4, 4-6, 6-10, and 10-20 mm particles) sphagnum peat or bark (2-4 and 10-20 mm). These substrates had different aeration properties and were used to grow Poinsettia and Impatiens ‘New Guinea’ in a greenhouse, resulting in differences in plant growth. The results show that air-filled porosity remained relatively unaffected by fragment size. Gas relative diffusivity differed significantly between treatments and was highest in the mix with the 2-4 mm particles and diminished rapidly as fragment size increased from 4 to 20 mm or decreased to 1-2 mm. Diffusivity was clearly lower in the bark/peat mixes but showed the same trend with coarse fragments. Root and shoot growth parameters were significantly and positively correlated to gas relative diffusivity. Moreover, the growth reduction observed in the bark/peat mixes relative to pure peat was most likely linked to limited gas exchange. Air-filled porosity assessments performed in situ (in the pot itself) or prior to potting, in cylinders, gave inconsistent results or were not significantly correlated to plant growth, indicating that aeration limitations are better diagnosed with gas diffusivity in growing media.Key words: Air-filled porosity, gas relative diffusivity, gas diffusion, peat substrates, bark, Euphorbia pulcherima, Impatiens (× novae-guinea)
Soil phosphorus fractions following annual paper mill biosolids and liming materials application
Authors: Fan J -L. , Ziadi N. , Gagnon B. , Hu Z -Y.
Published: November 2010

Industrial by-products such as paper mill biosolids (PB) and different liming materials have been used as fertilizers and amendments in agricultural soils for many decades. However, little is known about the effects of their repeated application on soil nutrient availability, particularly phosphorus (P). A 6-yr field study (2000-2005) was conducted in the province of Quebec to investigate the effect of repeated annual applications of different PB and industrial by-products on selected soil chemical properties, especially soil P fractions. Different PB rates (0 to 90 Mg wet ha-1) and several liming products (lime mud, wood ash, calcitic lime, and Mg by-products) were annually applied to field crops after seeding. Soils were sampled before seeding in May 2003 and at harvest in October 2005. Results showed that HCl-P was the largest P pool, accounting for about 64% of the total P fraction, and that the repeated applications of liming products significantly increased this pool and decreased the organic P pools. The NaOH-Po and residual-P were significantly lower in 2005 than in 2003, indicating that PB application without supplemental P fertilizer inputs enhanced the mobility and/or mineralization of NaOH-Po and the transformation of recalcitrant P to more labile forms with time. Lime mud (LM) was found to be the best liming material owing to its high neutralization capacity and positive effect on soil P availability over time. Key words: Paper mill biosolids, alkaline residuals, lime, wood ash, soil P fractions
Freezing-induced bulk soil volume changes
Authors: Dagesse D. F.
Published: November 2010

The volumetric expansion accompanying the phase transition from water to ice does not always cause structural deterioration in soil, as at low water contents the empty pore volume of the soil may be sufficient to contain this expansion. The objective of this study was to investigate the volume change in soils of varying clay contents and initial water contents during the freezing process. Volume change upon freezing was measured for seven soils with clay contents ranging from 0.11 to 0.75 kg kg–1. Curve fitting revealed percent saturation levels corresponding to maximum shrinkage, zero volume change and maximum expansion. Curves for all soils exhibited similar shapes, composed of zones dominated by volumetric decreases at values less that 63 to 70% saturation, and expansion at percent saturations above this level. Zero volume change occurred at percent saturations of 74 to 90%. Clay content was found to control the maximum amount of shrinkage, with greater shrinkage in soils with higher clay contents. Bulk soil volume decreases occur in non-rigid clay containing soils due to desiccation and shrinkage when frozen at low water contents.Key words: Volume change, soil freezing, cla
Estimation of daily soil CO2 flux using a single-time-point measurement
Authors: Wang H. , McConkey B. , Curtin D. , Cutforth H.
Published: November 2010

Information on soil CO2 emissions can be used in conjunction with data for C inputs from plants to estimate the soil C balance. Many studies assume a single-time-point measurement of soil CO2 flux taken in a day (Fh) is equal to its daily average value (Fd), which could result in over- or underestimation. A model using Fh, the temperature at the time the Fh is measured (Th), daily average temperature (Td) and Q10 factor to predict Fd was tested with extensive measurements of soil CO2 flux, temperature and moisture over 60 d from various treatments (no-till wheat, summer fallow and stubble, etc.) on a Swinton silt loam near Swift Current, Saskatchewan, Canada. A distinct hysteresis between flux and soil moisture was observed following rain events. Therefore, data for five rainy days were excluded from the analysis as the model does not consider the effect of hysteresis. Calculated Q10 factors were 1.86 and 1.54 for soil (Ts) and air (Ta) temperatures, respectively. The model using either Ts or Ta improved prediction of Fd in both calibration (49 d) and validation (6 d) datasets compared with Fh. Values of Fh measured in 6 yr were higher than modelled values of Fd in 96% of the 1602 treatment-days, hence if Fh is assumed to be equal to Fd, the averaged overestimation would be 17%.Key words: Soil CO2 flux, Q10 factor, temperature
Response of soil carbon and nitrogen to transplanted alfalfa in North Dakota rangeland
Authors: Liebig M A , Hendrickson J R , Berdahl J D
Published: November 2010

Incorporation of alfalfa (Medicago spp.) into rangelands can increase forage production and quality and may improve the soil resource. A study was conducted to quantify the effects of alfalfa transplanted into native rangeland on soil organic carbon (SOC) and total nitrogen (TN). Results from this study suggest both grazing- and hay-type alfalfa can increase stocks of soil C and N in native rangeland. However, concurrent increases in SOC and TN in a non-alfalfa control treatment underscore the importance of applying caution when interpreting results.Key words: Northern Great Plains, carbon sequestration, Medicago falcata, Medicago sativa
Improvements to the accuracy of modelled soil water content from the Second Generation Prairie Agrometeorological Model
Authors: Gervais M. , Bullock P. , Mkhabela M. , Finlay G. , Raddatz R.
Published: November 2010

The direct measurement of soil water on a regional scale is often not practical due to large instrumental and labour requirements. Alternatively, soil water estimates can be derived using models. The Second Generation Prairie Agrometeorological Model (PAMII) models soil water, crop development and evapotranspiration (ET) in order to derive an estimate of crop water use. The objective of this study was to validate, and if necessary modify, the soil water component of PAMII using weather and soil water data collected from several spring wheat trials in Saskatchewan and Manitoba during the 2003 though 2006 growing seasons. Comparison of modelled and measured soil water values yielded a RMSE of 62 mm. For most site-years, PAMII overestimated soil water during the second half of the growing season, which was caused by an increase in modelled canopy resistance (rc) before the crop experienced water stress. The rc function was thus modified so that rc would not increase until the soil water content was < 0.5 of plant available water. Overall this modification reduced the RMSE from 62 to 56 mm. In addition, modelled soil water was underestimated during periods that experienced consecutive days of precipitation. This was because the model stopped infiltration when the top-zone reached saturation. When modified to allow infiltration to continue independent of the top-zone’s water content, the RMSE was further reduced to 53 mm. Overall, both modifications reduced the RMSE of modelled soil water by 9 mm, and this reduction was highly significant (P < 0.01). Key words: Prairie Agrometeorological Model (PAMII), soil water modelling, evapotranspiration, Canadian prairies
Survival of Escherichia coli in agricultural soil and presence in tile drainage and shallow groundwater
Authors: VanderZaag A C , Campbell K J , Jamieson R C , Sinclair A C , Hynes L G
Published: November 2010

Animal agriculture and the use of manure as a soil amendment can lead to enteric pathogens entering water used for drinking, irrigation, and recreation. The presence of Escherichia coli in water is commonly used as an indicator of recent fecal contamination; however, a few recent studies suggest some E. coli populations are able to survive for extended time periods in agricultural soils. This important finding needs to be further assessed with field-scale studies. To this end, we conducted a 1-yr study within a 9.6-ha field that had received fertilizer and semi-solid dairy cattle manure annually for the past decade. Escherichia coli concentrations were monitored throughout the year (before and after manure application) in the effluent from tile drains (at approximately 80 cm depth) and in 5- to 8-m-deep groundwater wells. Escherichia coli was detected in both groundwater and tile drain effluent at concentrations exceeding irrigation and recreational water-quality guidelines. Within two of the monitoring wells, concentrations of E. coli, and frequency of detections, were greatest several months after the manure application. In two monitoring wells and one tile drain the frequency of E. coli detections was higher before manure was applied than after. This suggests the presence and abundance of E. coli was not strongly related to the timing of manure application. A laboratory study using naladixic acid resistant E. coli showed the bacteria could survive at least two times longer in soil samples collected from the study field than in soil from the adjacent riparian area, which had not received manure applications. Together, field and lab results suggest that a consistent source of E. coli exists within the field, which may include “naturalized” strains of E. coli. Further studies are required to determine the specific source of E. coli detected in tile drainage water and shallow groundwater. If the E. coli recovered in subsurface water is primarily mobilized from naturalized populations residing within the soil profile, this indicator organism would have little value as an indicator of recent fecal contamination. Key words: Bacterial survival, naturalized Escherichia coli, groundwater, tile drainage
Effect of Element Distortion on the Numerical Dispersion of Spectral Element Methods
Authors: Oliveira S.P. , Seriani G.
Published: November 2010

Spectral element methods are well established in the field of wave propagation, in particular because they inherit the flexibility of finite element methods and have low numerical dispersion error. The latter is experimentally acknowledged, but has been theoretically shown only in limited cases, such as Cartesian meshes. It is well known that a finite element mesh can contain distorted elements that generate numerical errors for very large distortions. In the present work, we study the effect of element distortion on the numerical dispersion error and determine the distortion range in which an accurate solution is obtained for a given error tolerance. We also discuss a double-grid calculation of the spectral element matrices that preserves accuracy in deformed geometries.
Numerical Simulations of Hydrodynamics of Nematic Liquid Crystals: Effects of Kinematic Transports
Authors: Zhang Shupeng , Liu Chun , Zhang Hui
Published: November 2010

In this paper, we investigate the effects of kinematic transports on the nematic liquid crystal system numerically and theoretically. The model we used is a “1+2” elastic continuum model simplified from the Ericksen-Leslie system. The numerical experiments are carried out by using a Legendre-Galerkin spectral method which can preserve the energy law in the discrete form. Based on this highly accurate numerical approach we find some interesting and important relationships between the kinematic transports and the characteristics of the flow. We make some analysis to explain these results. Several significant scaling properties are also verified by our simulations.
A Lattice Boltzmann-Direct Forcing/Fictitious Domain Model for Brownian Particles in Fluctuating Fluids
Authors: Nie Deming , Lin Jianzhong
Published: November 2010

The previously developed LB-DF/FD method derived from the lattice Boltzmann method and Direct Forcing/Fictitious Domain method is extended to deal with 3D particle’s Brownian motion. In the model the thermal fluctuations are introduced as random forces and torques acting on the Brownian particle. The hydrodynamic interaction is introduced by directly resolving the fluid motions. A sphere fluctuating in a cubic box with the periodic boundary is considered to validate the present model. By examining the velocity autocorrelation function (VCF) and rotational velocity autocorrelation function (RVCF), it has been found that in addition to the two relaxation times, the mass density ratio should be taken into consideration to check the accuracy and effectiveness of the present model. Furthermore, the fluctuation-dissipation theorem and equipartition theorem have been investigated for a single spherical particle. Finally, a Brownian particle trapped in a harmonic potential has been simulated to further demonstrate the ability of the LB-DF/FD model.
Charge induced stability of water droplets in subsaturated environment
Authors: Nielsen J. K. , Maus C. , Rzesanke D. , Leisner T.
Published: November 2010

Abstract. Atmospheric liquid and solid water particles are stabilized if they are coated with either negative or positive electric charge. The surface charge causes an increase of the partial pressure of water vapour close to the surface of each particle, effectively allowing the particles to remain in their condensed phase even if the environmental relative humidity drops below unity. The theory, briefly presented in this paper, predicts a zero parameter relation between surface charge density and water vapour pressure. This relation was tested in a series of Electrodynamical Balance experiments. The measurements were performed by stabilizing charged droplets of pure water near an ice-surface. We observed a divergence in radius as the temperature approached the freezing point from below. We find that the measurements confirm the theory within the experimental uncertainty. In some cases this generally overlooked effect may have impact on cloud processes and on results produced by Electrodynamical Balance experiments.