Testing the Performance of Two Maize Simulation Models with a Range of Cultivars of Maize (Zea mays) in Diverse Environments

Maize production is increasing in importance in Australia, and has potential for substantial further expansion. Additional production areas and/or more intensive use of existing production areas will be needed. Simulation models offer the capacity to rapidly assess the suitability of a range of genotypes and phenotypes, and to predict yield and yield reliability over a range of environmental conditions. However, they must be validated and be sufficiently robust to provide reliable predictions. The performance of two maize simulation models, a complex mechanistic one, AUSIM-Maize, and a simpler one, the Muchow - Sinclair model, was evaluated against experimental data from field trials at Gatton, South East Queensland and Katherine, Northern Territory. AUSIM-Maize predicts phenological and canopy development, total dry matter and grain yield. The Muchow - Sinclair model concentrates on total dry matter and grain yield. Sensitivity analysis indicated that the output of the models was most affected by the values used for the duration of the basic vegetative period, photoperiod sensitivity and leaf initiation rate (in AUSIM - Maize), radiation use efficiency, leaf appearance rate (in both models) and one coefficient that affects leaf area senescence (in the Muchow - Sinclair model). AUSIM - Maize consistently overpredicted the time from emergence to tassel initiation (especially with short season cultivars, and when environmental conditions favoured rapid plant development to TI), silking and physiological maturity. Leaf number was consistently overpredicted by AUSIM - Maize. Neither model predicted total dry matter or grain yield satisfactorily over the range in the experimental data, though each tended to be more accurate than the other on one measure of model performance (regression or root mean square deviation). Both provided sound predictions within a limited range of conditions and genotypes that resulted in relatively short crop durations, but were inaccurate when the data extended over a greater range of environmental conditions and genotypes. Several areas of the models where modification is needed to improve predictions and to make the models more generally applicable are identified

The influence of shear fixation stability on the histology and histomorphometry during fracture healing

Deckblatt-Impressum persönlicher Dank Verzeichnis der verwendeten Abkürzungen Inhaltsverzeichnis Einleitung Stand der Wissenschaft Material und Methoden Ergebnisse Diskussion Schlussfolgerungen Zusammenfassung Summary Literaturverzeichnis Danksagung SelbständigkeitserklärungInterfragmentäre Bewegungen haben auf den Verlauf und das Muster der Knochenheilung einen entscheidenden Einfluss. Zur gezielten Erforschung der Folgen interfragmentärer Scherbewegungen wurden in dieser Studie zwei identische externe Fixateure mit unterschiedlicher Schersteifigkeit am Schafmodell getestet. Der Heilungsverlauf mittels Fixateur externe versorgter osteotomierter Tibiae wurde anhand ausgewählter Zeitpunkte (zwei, drei, sechs und neun Wochen) nachvollzogen und der jeweilige Stand der Knochenheilung zwischen den Gruppen mit unterschiedlicher Fixation verglichen. Die histologische und histomorphometrische Auswertung der Tibiapräparate standen im Vordergrund dieser Studie. Insgesamt gingen 64 Tiere in die Untersuchung ein. Jeweils 32 Schafe wurden mit rigidem bzw. weichem Fixateur externe (geringere Schersteifigkeit) versorgt. Nach Montage der Osteosynthese wurde eine standardisierte Tibiaosteotomie mit Distraktion der Fragmente um drei Millimeter durchgeführt. Nach Euthanasie der Tiere zur jeweiligen Standzeit (zwei, drei, sechs oder neun Wochen post operationem) wurden radiologische, biomechanische, histologische und histomorphometrische Untersuchungen durchgeführt. Zwei Wochen post operationem wurde hinsichtlich der Knochenheilung kein Unterschied zwischen beiden Gruppen festgestellt, was den Schluss zu lässt, dass die Knochenheilung zu diesem Zeitpunkt größtenteils unbeeinflusst von den mechanischen Gegebenheiten stattfindet. Bereits drei Wochen post operationem hatte in der Gruppe mit rigidem Fixateur externe die Gesamtkallusfläche das Maximum erreicht und nahm anschließend tendenziell ab. Die biomechanischen sowie histologischen und histomorphometrischen Ergebnisse zeigten nach sechs Wochen eine fortgeschrittenere qualitativ hochwertigere Knochenheilung unter rigider Fixation. Die Gesamtkallusfläche in der Gruppe mit weicher Fixation war sechs Wochen post operationem noch auffallend größer und bindegewebsreicher als in der rigiden Gruppe. Nach neun Wochen kam es zur Annäherung der histologischen Ergebnisse beider Gruppen, wobei der knöcherne Kallusdurchmesser sowie die Gesamtkallusfläche unter weicher Fixation immer noch wesentlich größer waren als unter rigider Fixation. Zum neun Wochen Zeitpunkt hatten beide Gruppen einen qualitativ ähnlichen Kallus, was zu ähnlich guten biomechanischen Ergebnissen führte. Die Ergebnisse zeigen, dass etwas größere interfragmentäre Scherbewegungen die Knochenheilung initial wenig beeinflussen, dafür aber im Heilungsverlauf, v.a. im Bereich der dritten und sechsten Woche, zur verzögerten Heilung und schlechterer Kallusqualität führen können. Die relativ rigide Konstruktion beider Fixateure ermöglichte das komplikationslose Ausheilen der Osteotomie bei allen Tieren zum neun Wochen Zeitpunkt.Interfragmentary movements influence the pattern of fracture healing. The aim of this study was to investigate the effect of interfragmentary shear movements on the healing mechanism. For that reason two external fixators were created that differed only in their shear stiffness. In a standardized sheep- model the healing pattern after rigid fixation or semi-rigid fixation were determined. Therefore 64 sheep underwent a standardized mid-shaft osteotomy of the right tibia (gap = 3 mm). The osteotomy of 32 sheep were stabilized with the rigid fixator, the osteotomy of the other 32 sheep with the semi-rigid one. Groups of 8 sheep were allowed different healing periods (two, three, six or nine weeks). After sacrifice, x-rays were taken and the tibiae were testet biomechanically. Histological examination of the osteotomy area followed. The callus tissue quality and quantity were examined using a computerized image analysis system. No difference in fracture healing between the rigid and semi- rigid fixation group were found after two weeks. However, by three weeks some difference had begun to emerge. In the rigid group, the maximum total callus area was reached at three weeks, while in the semi-rigid group a maximum was not reached until 6 weeks. The fibrous tissue content was also higher in the semi-rigid group at six weeks, such that in the rigid group at six weeks a higher content of bone was present. At nine weeks a greater mineralized callus width and total callus area was determined in the semi-rigid group. The quality of the callus tissue at nine weeks was similar for both groups which correlated well with the results of torsional testing indicating similar mechanical competence of the calluses in both the rigid and semi-rigid fixation groups. The present study demonstrated that higher shear movements have no negative effect on the early phase of fracture healing. However the callus formation and differentiation were delayed in the third and sixth week. Six weeks after surgery, the larger callus was of inferor quality in the group with soft fixation. After nine weeks, the sheep of both groups had healed without complications and had reestablished mechanical competence to pre- osteotomy levels

A lead-width distribution for Antarctic sea ice: a case study for the Weddell Sea with high-resolution Sentinel-2 images

Using Copernicus Sentinel-2 images we derive a statistical lead-width distribution for the Weddell Sea. While previous work focused on the Arctic, this is the first lead-width distribution for Antarctic sea ice. Previous studies suggest that the lead-width distribution follows a power law with a positive exponent; however their results for the power-law exponents are not all in agreement with each other. To detect leads we create a sea-ice surface-type classification based on 20 carefully selected cloud-free Sentinel-2 Level-1C products, which have a resolution of 10 m. The observed time period is from November 2016 until February 2018, covering only the months from November to April. We apply two different fitting methods to the measured lead widths. The first fitting method is a linear fit, while the second method is based on a maximum likelihood approach. Here, we use both methods for the same lead-width data set to observe differences in the calculated power-law exponent. To further investigate influences on the power-law exponent, we define two different thresholds: one for open-water-covered leads and one for open-water-covered and nilas-covered leads. The influence of the lead threshold on the exponent is larger for the linear fit than for the method based on the maximum likelihood approach. We show that the exponent of the lead-width distribution ranges between 1.110 and 1.413 depending on the applied fitting method and lead threshold. This exponent for the Weddell Sea sea ice is smaller than the previously observed exponents for the Arctic sea ice.</p

Identification of a single nucleotide polymorphism associated with adiposity following transcriptional profiling of gene expression in the anterior pituitary gland

Although the anterior pituitary secretes three hormones that affect metabolism and body fat stores, a comprehensive analysis of pituitary gene expression associated with body fat has not been performed. This research used cDNA microarrays to investigate pituitary gene expression in two chicken lines that were selected for low and high body fat (Lean and Fat). RNA was extracted from pituitaries at 1, 3, 5, and 7 weeks of age. 386 genes that showed significant differences in expression levels by line or in the line-by-age interaction were analyzed further. Differentially expressed genes between lines are potential candidates as genetic markers for high and low potential for body fat accumulation. One such candidate, the lysophosphatidic acid (LPA) receptor-1 (LPAR1), was identified as a potential marker, being differentially expressed between the 2 lines at the early ages. Genomic DNA from the Fat and Lean F0 generation was sequenced upstream of the LPAR1 coding region. A SNP consisting of a T to C transversion that introduces a GATA-1 transcription factor binding site was identified in the Lean line (Fisher's Exact Test, p &amp;#8804; 0.001). The fattest and leanest animals of both sexes in the back-crossed F2 generation (n=48 each) were genotyped by allele-specific PCR, and an association was present between the genotype and phenotype (generalized linear model, p &amp;#8804; 0.05). Expression of GATA transcription factors in mice inhibits differentiation of preadipocytes into mature adipocytes. LPAR1 also inhibits differentiation of preadipocytes in mice, and LPAR1 knock-out mice become significantly fatter than wild-type mice. A SNP that introduces a GATA site in the promoter of LPAR1 could up-regulate its expression in the Lean line, and increased LPA signaling could then inhibit preadipocyte differentiation. Conversely, loss of the GATA binding site could explain decreased levels of LPAR1 expression and attenuated inhibition of adipocyte maturation in the Fat line

An Integrated Framework of Health Beliefs and Health Behaviors: The Impact of Socio-Cultural Factors in the Case of Type II Diabetes

The present study was designed to explore the mind-body connection within a psychosocial-cultural context. More specifically, the current investigator hoped to examine how various dimensions of the mind and body interact with psychosocial-environmental factors, which are significantly influenced by cultural processes and reference group membership A cross-sectional study was designed to examine the relationship between health beliefs and health behaviors in sample of 419 adults with Type II diabetes with a focus on the moderating effects of social support, emotional reactions, and experiences of unfair treatment. A self-report questionnaire comprised of 90-items obtained from previously established measures of health beliefs, psychosocial-cultural factors, and health behaviors was administered online via Qualtrics.com. Results of testing a series of measurement and structural models using confirmatory factor analysis (CFA) showed poor fit across all models specified. While these results indicated that the expanded Health Belief Model (eHBM) specified for this study did not adequately describe the diabetes-related thoughts, attitudes, and behaviors for the current sample of participants, findings may have provided preliminary evidence of a three-factor structure reflecting participants’ worries and concerns about their health & perceptions involving challenges or obstacles to successful behavior change, which could interfere with daily life. Although it is unclear whether these results were related to limitations in the measurement instruments and study design, or to differences in the nature of the constructs and the ways in which participants interpreted and responded to the scales, the overall findings of this study suggest a need for research that examines the equivalence of health belief and health behavior measures and greater empirical evidence to ensure that the theories and models used in health research are generalizable across groups of people with varying world-views, identities and lived experiences. Implications for the Health Belief Model (HBM) and ideas for future research are discussed

Exploring the role of legal status and neighborhood social capital on immigrant economic integration in Los Angeles

Background: Existing research has emphasized immigration policy and social capital as two crucial elements of reception that influence immigrant labor market outcomes. While much attention has been paid to these two factors in isolation, a limited body of empirical work has examined how they intersect, specifically how social capital influences the economic integration of immigrants legally precluded from the formal labor market. Objective: Our goal is to examine the extent to which immigrant legal status conditions economic integration in the United States and whether neighborhood social capital moderates this relationship. Methods: This study relies on a large probability sample of individuals residing in Los Angeles County that directly ascertains the legal status of immigrants. We employ inverse probability of treatment-weighted linear regressions to compare the labor market outcomes of undocumented immigrants to those of immigrants with varying forms of legal status and to examine how neighborhood social capital moderates the link between legal status and economic attainment. Conclusions: We find two distinct modes of economic incorporation: one of steady work and higher wages among immigrants with citizenship status, and one of lower earnings and greater reliance on self-employment among immigrants in the country without documentation. Our results suggest that neighborhood social capital does not improve the labor market prospects of undocumented immigrants and in some cases may penalize them. Contribution: By extending research on immigrant economic integration, this study highlights the labor market penalties experienced by undocumented immigrants, the limitations of neighborhood social capital in facilitating their integration into the American economy, and the potential value of self-employment

Introduction

Introduction / Cathy Callaway -- Linguistics and lentil soup / Pamela A. Draper -- Eugene Lane and Ellis Library / Michael Muchow -- Gene Lane : Commitment to scholarship, teaching, and community / Robert A. Seelinger, Jr. -- Tabula Gratulatoria