Multi-trait evolution of farmer varieties of bread wheat after cultivation in contrasting organic farming systems in Europe.

Because of the lack of varieties for organic agriculture, associations of organic farmers in several European countries have begun cultivating landraces and historic varieties, effectively practicing in situ conservation of agricultural biodiversity. To promote agrobiodiversity conservation, a special list for "conservation varieties" was implemented in 2008 by the EU because for any exchange and marketing of seeds in the EU, a variety must be registered in an official catalog. Our study aimed at improving knowledge on the phenotypic diversity and evolution of such varieties when cultivated on organic farms in Europe, in order to better define their specific characteristics and the implications for the registration process. We assessed multi-trait phenotypic evolution in eight European landraces and historic varieties of bread wheat and in two pureline variety checks, each grown by eight organic farmers over 2 years and then evaluated in a common garden experiment at an organic research farm. Measurements on each farmer's version of each variety included several standard evaluation criteria for assessing distinctness, uniformity and stability for variety registration. Significant phenotypic differentiation was found among farmers' versions of each variety. Some varieties showed considerable variation among versions while others showed fewer phenotypic changes, even in comparison to the two checks. Although farmers' variety would not satisfy uniformity or stability criteria as defined in the catalog evaluation requirements, each variety remained distinct when assessed using multivariate analysis. The amount of differentiation may be related to the initial genetic diversity within landraces and historic varieties.

Genome-wide association analysis to identify chromosomal regions determining components of earliness in wheat.

The modification of flowering date is considered an important way to escape the current or future climatic constraints that affect wheat crops. A better understanding of its genetic bases would enable a more efficient and rapid modification through breeding. The objective of this study was to identify chromosomal regions associated with earliness in wheat. A 227-wheat core collection chosen to be highly contrasted for earliness was characterized for heading date. Experiments were conducted in controlled conditions and in the field for 3 years to break down earliness in the component traits: photoperiod sensitivity, vernalization requirement and narrow-sense earliness. Whole-genome association mapping was carried out using 760 molecular markers and taking into account the five ancestral group structure. We identified 62 markers individually associated to earliness components corresponding to 33 chromosomal regions. In addition, we identified 15 other significant markers and seven more regions by testing marker pair interactions. Co-localizations were observed with the Ppd-1, Vrn-1 and Rht-1 candidate genes. Using an independent set of lines to validate the model built for heading date, we were able to explain 34% of the variation using the structure and the significant markers. Results were compared with already published data using bi-parental populations giving an insight into the genetic architecture of flowering time in wheat.

Inbreeding depression and low between-population heterosis in recently diverged experimental populations of a selfing species.

In fragmented populations, genetic drift and selection reduce genetic diversity, which in turn results in a loss of fitness or in a loss of evolvability. Genetic rescue, that is, controlled input of diversity from distant populations, may restore evolutionary potential, whereas outbreeding depression might counteract the positive effect of this strategy. We carried out self-pollination and crosses within and between populations in an experimental subdivided population of a selfing species, Triticum aestivum L., to estimate the magnitude of these two phenomena. Surprisingly, for a self-fertilizing species, we found significant inbreeding depression within each population for four of the six traits studied, indicating that mildly deleterious mutations were still segregating in these populations. The progeny of within- and between-population crosses was very similar, indicating low between-population heterosis and little outbreeding depression. We conclude that relatively large population effective sizes prevented fixation of a high genetic load and that local adaptation was limited in these recently diverged populations. The kinship coefficient estimated between the parents using 20 neutral markers was a poor predictor of the progeny phenotypic values, indicating that there was a weak link between neutral diversity and genes controlling fitness-related traits. These results show that when assessing the viability of natural populations and the need for genetic rescue, the use of neutral markers should be complemented with information about the presence of local adaptation in the subdivided population.

Aromatic hydrazones derived from nicotinic acid hydrazide as fluorimetric pH sensing molecules: Structural analysis by computational and spectroscopic methods in solid phase and in solution.

Structural analyses of aroylhydrazones were performed by computational and spectroscopic methods (solid state NMR, 1 and 2D NMR spectroscopy, FT-IR (ATR) spectroscopy, Raman spectroscopy, UV-Vis spectrometry and spectrofluorimetry) in solid state and in solution. The studied compounds were N'-(2,3-dihydroxyphenylmethylidene)-3-pyridinecarbohydrazide (1), N'-(2,5-dihydroxyphenylmethylidene)-3-pyridinecarbohydrazide (2), N'-(3-chloro-2-hydroxy-phenylmethylidene)-3-pyridinecarbohydrazide (3), and N'-(2-hydroxy-4-methoxyphenyl-methylidene)-3-pyridinecarbohydrazide (4). Both in solid state and in solution, all compounds were in ketoamine form (form I, CONHNC), stabilized by intramolecular H-bond between hydroxyl proton and nitrogen atom of the CN group. In solid state, the CO group of 1-4 were involved in additional intermolecular H-bond between closely packed molecules. Among hydrazones studied, the chloro- and methoxy-derivatives have shown pH dependent and reversible fluorescence emission connected to deprotonation/protonation of salicylidene part of the molecules. All findings acquired by experimental methods (NMR, IR, Raman, and UV-Vis spectra) were in excellent agreement with those obtained by computational methods.

Assessing pesticide risks to threatened and endangered species using population models: Findings and recommendations from a CropLife America Science Forum.

This brief communication reports on the main findings and recommendations from the 2014 Science Forum organized by CropLife America. The aim of the Forum was to gain a better understanding of the current status of population models and how they could be used in ecological risk assessments for threatened and endangered species potentially exposed to pesticides in the United States. The Forum panelists' recommendations are intended to assist the relevant government agencies with implementation of population modeling in future endangered species risk assessments for pesticides. The Forum included keynote presentations that provided an overview of current practices, highlighted the findings of a recent National Academy of Sciences report and its implications, reviewed the main categories of existing population models and the types of risk expressions that can be produced as model outputs, and provided examples of how population models are currently being used in different legislative contexts. The panel concluded that models developed for listed species assessments should provide quantitative risk estimates, incorporate realistic variability in environmental and demographic factors, integrate complex patterns of exposure and effects, and use baseline conditions that include present factors that have caused the species to be listed (e.g., habitat loss, invasive species) or have resulted in positive management action. Furthermore, the panel advocates for the formation of a multipartite advisory committee to provide best available knowledge and guidance related to model implementation and use, to address such needs as more systematic collection, digitization, and dissemination of data for listed species; consideration of the newest developments in good modeling practice; comprehensive review of existing population models and their applicability for listed species assessments; and development of case studies using a few well-tested models for particular species to demonstrate proof of concept. To advance our common goals, the panel recommends the following as important areas for further research and development: quantitative analysis of the causes of species listings to guide model development; systematic assessment of the relative role of toxicity versus other factors in driving pesticide risk; additional study of how interactions between density dependence and pesticides influence risk; and development of pragmatic approaches to assessing indirect effects of pesticides on listed species.

Elimination of mercury from amalgam in rats.

The aim of this study was to measure the urinary mercury excretion in rats exposed to amalgam over a two months period. Animals were either exposed to mercury from 4 dental amalgams or fed the diet containing powdered amalgams. The results showed significantly higher mercury amount in urine of both exposed groups than in control. Even two months after the amalgam had been placed in rats teeth, the amount of mercury in the urine remained 4-5 times higher than in control, and 4 times higher than in rats exposed to diet containing powdered amalgam. The elevated urinary Hg amount was accompanied by an increased level of total protein in urine. In the same exposure period the excretion of total protein in urine of rats with amalgam fillings was 2 times higher than in control and 1.5 times higher than in rats exposed to amalgam through diet. Concentrations of mercury in the sera of all groups were below the detection limit of the method. The results show that amount of mercury and protein in the urine of rats were related to the mercury release from dental malgam.

Trichomonas tenax proteolytic activity.

In this study, proteolytic activity of Trichomonas tenax collected directly from patient's dentobacterial plaque was examined. Electrophoretic method involving polyacrylamide gels (Commassie Brilliant Blue R-250) and electrophoretic method involving gelatin-containing polyacrylamide gels, have been used to analyse Trichomonas tenax proteolytic activity. The most obvious and the fastest activities were obtained when gels were incubated in pH 4.6; followed by results of incubating in pH 5.6; while in pH 2.8 activity was less effective but still obvious. Proteolytic activities were the most effective in area of protein MW 36 kDa. Different activities of enzymes depending on pH of incubated media indicate the presence of different endopeptidases in cell lysates of protozoon Trichomonas tenax from dentobacterial plaque.

The influence of dental amalgam on the blood count.

The purpose of this research was to determine the influence of dental amalgam on the blood count of the holder of amalgam fillings. The experiments were performed on 30 Wistar rats. One group of rats received 8 mg of fragmented dental amalgam daily incorporated in their food during 60 days (group S2) and group S3 received amalgam fillings in their anterior teeth, which remained for 60 days. Both experiment groups (S2 and S3) were compared to one another as well as to control group (S1). From all animals of all experiment groups blood samples were drawn during the experiment in particular periods and complete blood count and differential blood count was performed. The findings of particular indicators of the complete blood count and differential blood count of all experiment rats groups S1, S2 and S3 do not deviate from the physiological values regarding age and sex of the observed animals.

Comparison of dental maturity between two ethnic groups.

Dental maturity is one of the indicators of the craniofacial region growth and development. The aim of the study was to identify and compare dental growth and development in two ethnic groups. The material consisted of 480 orthopantomograms; 240 selected from orthodontic and dental patients from Zagreb (Croatia) and Damascus (Syria) each. Each ethnic group included 120 boys and 120 girls, while the radiographs were classified into 6 groups of 20 each, according to sex and chronologic age (8-13 years). Dental maturity was evaluated by the method of Nolla. The results were statistically analyzed and presented in tables. The subjects from Damascus showed a delay in dental maturity by 1 (girls) to 2 (boys) years compared to the homologous group from Zagreb. The reference values determined in the study may serve as a diagnostic, therapeutic and prognostic tool in the orthodontics and pedodontics of the respective cities.

Alterations in optic canal following resection of nerve in rats.

The authors have studied relations between bony optic canal and nerve elements resulting from lesion in the optic nerve. Experimental animals were divided in two groups: young adults and old adult rats; the non-operated sides of rat skulls were used as a control group. At the same time in control samples the changes in osseous openings resulting from ageing were studied. Four months after surgery the animals were sacrificed, their skulls macerated and morphometric measurements taken by photometric and planimetric techniques. The obtained results show no significant difference in size of bony openings between the operated and non-operated sides. A significant difference has been found in the size of optic canal between the young and the old rats, regardless of the operated side. The authors have thus come to the conclusion that the size of bony canals in adult animals depends on their age in the first place. Narrowing of bony canaliculi, observed in the course of ageing, is most probably caused by primary osseous apposition, while atrophy of nerve elements may be considered as a secondary event.

Evaluation of sporadic cases of odontogenic keratocysts in multicentric study.

The aim of this retrospective study was to report frequency of sporadic odontogenic keratocysts (sOKC) according to the age and gender, as well as location (mandible, maxilla, soft tissues, and maxillary sinus). Four hundred and twenty nine sOKC confirmed pathohistologically in a period from 1965-1998 were included in this study. The average age of patients with sOKC was 43.11 (age range 10-91), in males 42.06 and in females 44.72 years. More frequently sOKC were found in males (60.61%) in comparison to the females (39.39%). Therefore, ratio between males and females was 1.5:1. Diagnosis of sOKC is usually established in patients aged 21-30 (18.88%), in males usually aged between 21-30 (23.46%), and in females aged between 11-20 (18.93%). sOKC are more frequent in males according to the age groups, except between age 61-70 where sOKC were more frequent in females. Most frequently, sOKC occurred in the mandible 70.16%, 12.35% of sOKC were found in the maxilla, 12.82% in soft tissues and 4.66% in the maxillary sinuses.

Clonal spread of Salmonella enterica serovar Infantis in Serbia: acquisition of mutations in the topoisomerase genes gyrA and parC leads to increased resistance to fluoroquinolones.

Quinolone-resistant Salmonella Infantis (n = 64) isolated from human stool samples, food and poultry during the years 2006-2011 were analysed for their resistance phenotypes, macrorestriction patterns and molecular mechanisms of decreased susceptibility to fluoroquinolones. Minimum inhibitory concentrations (MICs) of nalidixic acid (NAL) and ciprofloxacin (CIP) were determined by the agar dilution procedure, and the susceptibility to additional antimicrobial agents was determined by the disc diffusion method. To assess the influence of enhanced efflux activity, MICs were determined in the presence and absence of the inhibitor PAßN. The results of pulsed-field gel electrophoresis (PFGE) typing revealed that quinolone-resistant S. Infantis in Serbia had similar or indistinguishable PFGE profiles, suggesting a clonal spread. All S. Infantis showed combined resistance to NAL and tetracycline, whereas multiple drug resistance to three or more antibiotic classes was rare (2 isolates of human origin). The MICs ranged between 512 and 1024 µg/mL for NAL and 0.125-2 µg/mL for CIP. A single-point mutation in the gene gyrA leading to a Ser83→Tyr exchange was detected in all isolates, and a second exchange (Ser80→Arg) in the gene parC was only present in eight S. Infantis isolates exhibiting slightly higher MICs of CIP (2 µg/mL). The inhibitor PAßN decreased the MIC values of CIP by two dilution steps and of NAL by at minimum 3-6 dilution steps, indicating that enhanced efflux plays an important role in quinolone resistance in these isolates. The plasmid-mediated genes qnr, aac(6')-lb-cr and qepA were not detected by PCR assays.

Genotoxicity evaluation of five different dentin bonding agents by chromosomal aberration analysis.

Dentin bonding agents became unavoidable in today's aesthetic restorative dentistry. Nevertheless, more and more evidences on their possible cytotoxicity and/or genotoxicity emerge. Still, only limited number of studies has been published on that issue. In our work we evaluated possible genotoxicity of five different adhesives: Adper Single Bond, Adper Single Bond 2 with nanofiller, Excite, OptiBond Solo Plus and Prompt L-pop. Genotoxicity assessment was carried out on human lymphocytes in vitro, using chromosomal aberration analysis. Polymerized adhesives were tested at three different dilutions of the 0.5 g mL(-1) eluate stock (2.5 x 1:10(6), 1:10(6) and 1:10(5)) after 1 h, 24 h and 5 days of elution. Slight but significant increase in the number of chromatid breaks was observed after 24-h elution period, for adhesives Adper Single Bond 2, Excite, and OptiBond Solo Plus at dilutions of 1:10(6) and 1:10(5), and for other two only at dilution of 1:10(5). First three adhesives also appeared to be slightly genotoxic after 1 h of elution but only at 1:10(5). As a bonding agent remains in close contact with living dental tissue over a long period of time, information on their possible genotoxicity and carcinogenicity should be more clearly clarified in the near future.

Dental amalgam mercury exposure in rats.

The aim of this study was to measure the distribution of mercury, in tissues of rats exposed to amalgam over a two months period. Possible interaction of mercury with copper and zinc in organs was also evaluated. Rats were either exposed to mercury from 4 dental amalgams, or fed the diet containing powdered amalgam during two months. Mercury was measured in the kidney, liver and brain, copper in kidney and brain and zinc in kidney. The results showed significantly higher concentrations of mercury in the kidneys and the brains of rats in both exposed groups compared to control. Even after two months of exposure to mercury brain mercury concentration in rats with amalgam fillings was 8 times higher than in the control and 2 times higher than in rats exposed to amalgam supplemented diet. The highest mercury concentration in the latter group was found in the kidneys and it was 5 times higher than in the control group. We found no significant differences between mercury levels in exposed and control rat's liver. Exposure to mercury from dental amalgams did not alter the concentrations of copper and zinc in the tissues. Histopathological analyses of rats tissues did not show any pathological changes. These results support previously proposed nose-brain transport of mercury released from dental amalgam fillings.