Linda Nielsen

Real-time PCR for quantification of eleven individual Fusarium species in cereals

Contamination of cereals with Fusarium species is one of the major sources of mycotoxins in food and feed. Quantification of biomass of Fusarium species is essential to understand the interactions of individual species in disease development. In this study quantitative real-time PCR assays based on the elongation factor 1 alpha (EF1alpha) gene for the 11 Fusarium species F. graminearum, F. culmorum, F. poae, F. langsethiae, F. sporotrichioides, F. equiseti, F. tricinctum, F. avenaceum, F. verticillioides, F. subglutinans and F. proliferatum were developed and tested on 24 wheat and 24 maize field samples. The assays were found to be specific and sensitive. Generally, the results from the quantitative real-time PCR assays corresponded well with mycotoxin data of the field samples.

TRI12 based quantitative real-time PCR assays reveal the distribution of trichothecene genotypes of F. graminearum and F. culmorum isolates in Danish small grain cereals.

Quantitative real-time PCR assays, based on polymorphisms in the TRI12 gene of the trichothecene pathway, were developed to identify and quantify the trichothecene genotypes producing 3-acetyl-deoxynivalenol (3ADON), 15-acetyl-deoxynivalenol (15ADON) or nivalenol (NIV) in the Fusarium graminearum species complex, Fusarium culmorum, Fusarium cerealis and Fusarium pseudograminearum. These assays were applied on a total of 378 field samples of cereal grain of wheat, barley, triticale, rye and oats collected from 2003 to 2007 to study the trichothecene genotype composition in Danish cereals. The three genotypes, 3ADON, 15ADON and NIV were found in all five cereal species, great annual variation in the occurrence of the trichothecene genotypes was evident with considerable variation between the samples. 3ADON was the dominant genotype in barley, triticale, rye and oats while 15ADON was most dominant in wheat. The NIV genotype was found at low levels in most samples. Study of genotype composition within the Danish F. graminearum and F. culmorum population was based on principal component analysis (PCA). PCA revealed that the dominating genotype of F. graminearum in wheat is 15ADON. For barley, the PCA analysis indicated that the F. graminearum population consisted of all three genotypes, and in triticale, the F. graminearum population consisted mainly of 15ADON genotype. F. culmorum/F. cerealis showed correlation to the NIV genotype in wheat and triticale but not in barley. F. culmorum/F. cerealis also showed some correlation to 3ADON especially in wheat and triticale. Selected wheat and barley samples from 1957 to 2000 showed low amounts of F. graminearum and F. culmorum in general but with a dominance of the 3ADON genotype. 15ADON was not detected in these samples, except for very low amounts in the sample representing the years from 1997 to 2000. Detection of low amounts of the 15ADON genotype in these historical samples and the relatively high amounts of 15ADON genotype in 2003 and following years correspond well with the occurrence of F. graminearum and indicates that the 15ADON genotype was introduced along with F. graminearum around 2000. The amounts of the 3ADON and 15ADON genotypes correlated well with the total amount of DON whereas the amounts of NIV genotype correlated well with the amount of NIV in wheat and triticale but not in barley where the results indicate that Fusarium poae may also contribute to the NIV content.

Shared Physical Custody: Summary of 40 Studies on Outcomes for Children

One of the most complex and compelling issues confronting policymakers, parents, and professionals involved in making custody decisions is this: What type of parenting plan is most beneficial for the children after their parents separate? More specifically, are the outcomes any better or worse for children who live with each parent at least 35% of the time compared to children who live primarily with their mother and spend less than 35% of the time living with their father? This article addresses this question by summarizing the 40 studies that have compared children in these two types of families during the past 25 years. Overall the children in shared parenting families had better outcomes on measures of emotional, behavioral, and psychological well-being, as well as better physical health and better relationships with their fathers and their mothers, benefits that remained even when there were high levels of conflict between their parents.

Comparison of penaeid shrimp and insect parvoviruses suggests that viral transfers may occur between two distantly related arthropod groups

The DNA and putative amino acid sequences of representative insect and shrimp parvoviruses (subfamily Densovirinae) were analyzed using computer programs. Shrimp viruses included hepatopancreatic parvovirus (HPV) of Penaeus monodon (HPVmon) and P. chinensis (HPVchin), spawner-isolated mortality virus from P. monodon (SMVmon) and infectious hypodermal and hematopoietic necrosis virus (IHHNV) from P. vannamei. Insect viruses included Aedes aegypti densovirus (AaeDNV), Aedes albopictus densovirus (AalDNV), Junonia coenia densovirus (JcDNV), Galleria mellonella densovirus (GmDNV), Bombyx mori densovirus 5 (BmDNV), Diatraea saccharalis densovirus (DsDNV) and Periplaneta fuliginosa densovirus (PfDNV). Virion size for all these viruses ranged between 18 and 30 nm diameter and ssDNA genome length was between 4 and 6 kb. Using BLAST or Clustal W with the sequence fragments available, no significant DNA homology was found except for 77% DNA identity between HPVmon and HPVchin. However, phylogenetic trees constructed by comparing DNA genome sequences for putative viral polypeptides, capsid proteins and nonstructural proteins placed the parvoviruses into two Clades: Clade 1 with SMVmon, PfDNV, DsDNV, GmDNV, JcDNV, and BmDNV; and Clade 2 with HPVmon, HPVchin, IHHNV, AalDNV and AaeDNV. The four shrimp parvoviruses fell into two different clades that grouped with different insect parvoviruses.

Re-examining the research on parental conflict, coparenting, and custody arrangements.

This article addresses 4 questions: First, how much weight should be given to parental conflict and the quality of the coparenting relationship in determining parenting time—specifically with respect to children’s living at least 35% time with each parent in joint physical custody? Second, to what extent are low conflict and cooperative coparenting connected to better outcomes for children? Third, to what degree are children’s outcomes linked to whether their parents take their custody disputes to court or have high legal conflict? Fourth, is joint physical custody associated with worse outcomes than sole physical custody for children whose parents have a conflicted, uncooperative coparenting relationship? Recent research does not support the idea that conflict—including high legal conflict—should rule out joint physical custody as the arrangement that best serves children’s interests. Parents with joint physical custody do not generally have significantly less conflict or more cooperative relationships than parents with sole physical custody. Conflict and poor coparenting are not linked to worse outcomes for children in joint physical custody than in sole physical custody. The quality of the parent–child relationship is a better predictor than conflict of children’s outcomes, with the exception of the most extreme forms of conflict to which some children are exposed. While continuing our efforts to improve parents’ relationships with one another, we should become more invested in helping both parents maintain and strengthen their relationships with their children.

Parenting Plans for Infants, Toddlers, and Preschoolers: Research and Issues

In the debate over parenting plans for infants and toddlers, a central question is whether these very young children should spend overnight time away from their mothers in their fathers’ care. This article summarizes and critiques the 11 empirical studies that have addressed this question. Overall, overnighting was not associated with negative outcomes for infants and toddlers and was associated with positive outcomes for preschoolers.

Young Adult Daughters' Relationships With Their Fathers: Review of Recent Research

The young adult years raise a number of intriguing questions about the relationship between fathers and daughters. How does the quality of their relationship throughout childhood manifest itself during a daughters college years? In what specific ways is the “well-fathered” daughter advantaged compared with daughters who had troubled or distant relationships with their fathers? What aspects of the daughters college and early adult life are generally more influenced by her relationship with her father than by her relationship with her mother? This review of recent research provides intriguing and occasionally surprising answers to these questions about young adult daughters and their fathers.

Joint versus sole physical custody: Outcomes for children independent of family income or parental conflict

ABSTRACT Is joint physical custody (JPC) linked to any better or worse outcomes for children than sole physical custody (SPC) after considering family income and parental conflict? In the 60 studies published in English in academic journals or in government reports, 34 studies found that JPC children had better outcomes on all of the measures of behavioral, emotional, physical, and academic well-being and relationships with parents and grandparents. In 14 studies, JPC children had equal outcomes on some measures and better outcomes on others compared to SPC children. In 6 studies JPC and SPC children were equal on all measures. In 6 studies, JPC children were worse on one of the measures than SPC children, but equal or better on all other measures. In the 25 studies that considered family income, JPC children had better outcomes on all measures in 18 studies, equal to better outcomes in 4 studies, equal outcomes in 1 study, and worse outcomes on one measure but equal or better outcomes on other measures in 2 studies. In the 19 studies that included parental conflict, JPC children had better outcomes on all measures in 9 studies, equal to better outcomes in 5 studies, equal outcomes in 2 studies, and worse outcomes on one measure but equal or better outcomes on other measures in 3 studies. In sum, independent of family income or parental conflict, JPC is generally linked to better outcomes for children.

Pop Goes the Woozle: Being Misled by Research on Child Custody and Parenting Plans

Mental health professionals, lawyers, and judges whose work involves child custody decisions are often presented with social science research on issues related to which parenting plan is in the children’s best interests. Unfortunately, this research can be misrepresented in ways that mislead these professionals and the children’s parents, leading to child custody decisions that are not the most beneficial for the children. The process of misrepresenting the research in ways that create myths and misconceptions has been referred to as woozling. This article describes how social science data can be woozled, illustrating this with examples related to parenting plans for children under the age of 5 whose parents have separated.

Control of seedling blight in winter wheat by seed treatments – impact on emergence, crop stand, yield and deoxynivalenol

Abstract Seedling blight caused by Fusarium spp. and Microdochium spp. is common on wheat grain, and severe attacks can lead to poor establishment of new crops. Several seed treatments using bitertanol, difenoconazole, triticonazole, maneb, fludioxonil or guazatine found to significantly control Fusarium seedling blight (Fusarium spp., Microdochium spp.) were improving germination and reducing seedling blight on roots and coleoptiles under field conditions in winter wheat. Some of the seed treatments were also shown to have an impact on soil-borne Fusarium in trials carried out under glasshouse conditions. In three field trials with 5–45% infected seeds no significant improvements on yields were seen from seed treatments, indicating that the Danish threshold of 15% attacked seeds is a conservative threshold. In two field trials including seed lots with more than 90% infected seeds, fludioxonil improved germination by approximately 100%, which led to an improved crop stand and yield increases in the range of 1.2–1.5 tonnes ha−1. Attacks of Fusarium head blight were relatively slight in the two trials and the content of deoxynivalenol was below the EU limits of 1250 ppb in the harvested grain. Even so, seed treatments with fludioxonil did not help reduce attacks of Fusarium head blight at GS 75 or content of deoxynivalenol in the harvested grain.