Lead plant 15N natural abundance for measuring its biological nitrogen fixation potential.

Leadplant (Amorpha canescens Pursh) is a prairie legume naturally occurring in the pastures of Nebraska Sand Hills area, as well as most of pasturelands of Central USA. Samples of Leadplant growing in two different paddocks of the University of Nebraska Bartha Brother's Ranch were collected at random and mixed to provide six replications per paddock, in early spring and late summer. In parallel, samples of six different non-legume species (or replications of a given species) growing in the same area were collected. The paddocks differ only by their rate of pasture utilization in the last few years. All samples were analyzed for their N content and natural abundance of the isotope 15N (d15N). The15N dilution technique was applied to evaluate the amount of N in Leadplant derived from biological N fixation, being assumed that the averaged d15N content of the non-legumes represents the basal soil N isotopic composition, and any dilution on that would be caused by N obtained from the atmosphe, with d15N equals to zero. Leadplant samples were significantly (p<0.001) more enriched in total N than the non-legumes (total average of 2.09% compared to 1.37%). They were also significantly (p<0.001) more depleted in d15N (total average of -2.049 compared to -4.294). Averaged N in Leadplant derived from biological N fixation varied from 39% to 46% and from 51% to 66% in the first and second paddocks in early spring and late summer, respectively. These results confirms the importance of this legume for the maintenance of natural and introduced pastures.Paper 61713. Online

Effect of Nitrogen on Properties of Na2O-CaO-SrO-ZnO-SiO2 Glasses

Glasses in the Na2O-CaO-SrO-ZnO-SiO2 system have previously been investigated for suitability as a reagent in Al-free glass polyalkenoate cements (GPCs). These materials have many properties that offer potential in orthopedics. However, their applicability has been limited, to date, because of their poor strength. This study was undertaken with the aim of increasing the mechanical properties of a series of these Zn-based GPC glasses by doping with nitrogen to give overall compositions of: 10Na2O-10CaO-20SrO-20ZnO-(40-3x)SiO2-xSi3N4 (x is the no. of moles of Si3N4). The density, glass-transition temperature, hardness, and elastic modulus of each glass were found to increase fairly linearly with nitrogen content. Indentation fracture resistance also increases with nitrogen content according to a power law relationship. These increases are consistent with the incorporation of N into the glass structure in threefold coordination with silicon resulting in extra cross-linking of the glass network. This was confirmed using 29Si MAS-NMR which showed that an increasing number of Q2 units and some Q3 units with extra bridging anions are formed as nitrogen content increases at the expense of Q1 units. A small proportion of Zn ions are found to be in tetrahedral coordination in the base oxide glass and the proportion of these increases with the presence of nitrogen

Visual Fixations Duration as an Indicator of Skill Level in eSports

Using highly interactive systems like computer games requires a lot of visual activity and eye movements. Eye movements are best characterized by visual fixation - periods of time when the eyes stay relatively still over an object. We analyzed the distributions of fixation duration of professional athletes, amateur and newbie players. We show that the analysis of fixation durations can be used to deduce the skill level in computer game players. Highly skilled gaming performance is characterized by more variability in fixation durations and by bimodal fixation duration distributions suggesting the presence of two fixation types in high skill gamers. These fixation types were identified as ambient (automatic spatial processing) and focal (conscious visual processing). The analysis of computer gamers' skill level via the analysis of fixation durations may be used in developing adaptive interfaces and in interface design.Comment: 10 pages, 3 figure

Study of the economic impact of cryptosporidiosis in calves after implementing good practices to manage the disease on dairy farms in Belgium, France, and the Netherlands

Cryptosporidium spp. are widespread parasitic protozoans causing enteric infections in humans and animals. The parasites cause neonatal diarrhoea in calves, leading to a high mortality rate in the first 3 weeks. Losses are significant for farmers, but the cost of cryptosporidiosis remains poorly documented. In the absence of a vaccine, only preventive measures are available to farmers to combat the infection. This study, conducted between 2018 and 2021, aimed to evaluate the economic impact of Cryptosporidium spp. on European dairy farms and monitor changes in costs after implementing disease management measures. First, a field survey was carried out and questionnaires administered to 57 farmers in Belgium, France, and the Netherlands. The aim of the survey was to assess the losses associated with the occurrence of diarrhoea in calves aged between 3 days and 3 weeks. The economic impact of diarrhoea was calculated based on mortality losses, health expenditures, and additional labour costs. To refine the cost estimation specifically for Cryptosporidium spp., stool samples were collected from 10 calves per farm. The prevalence of Cryptosporidium spp. was determined, and the economic impact of diarrhoea was adjusted accordingly. The assumption was made that a certain percentage of costs was attributed to cryptosporidiosis based on the prevalence. These protocols were repeated at the end of the study to observe changes in costs. In the three years, the cost of diarrhoea for the 28 farms that stayed in the panel all along the study improved from €140 in 2018 to €106 on average per diarrhoeic calf in 2021. With a stable prevalence at 40%, the cost of cryptosporidiosis per infected calf decreased from €60.62 to €45.91 in Belgium, from €43.83 to €32.14 in France, and from €58.24 to €39.48 in the Netherlands. This represented an average of €15 saved per infected calf. The methodology employed in this study did not allow us to conclude that the improvement is strictly due to the implementation of preventive measures. However, with 11 million calves raised in the Interreg 2 Seas area covered by the study, it provided valuable insights into the economic burden of Cryptosporidium spp

A phase i pharmacokinetic study of the vascular disrupting agent ombrabulin (AVE8062) and docetaxel in advanced solid tumours

Background: The vascular disrupting agent ombrabulin shows synergy with docetaxel in vivo. Recommended phase II doses were determined in a dose escalation study in advanced solid tumours. Methods: Ombrabulin (30-min infusion, day 1) followed by docetaxel (1-h infusion, day 2) every 3 weeks was explored. Ombrabulin was escalated from 11.5 to 42 mg m -2 with 75 mg m -2 docetaxel, then from 30 to 35 mg m -2 with 100 mg m -2 docetaxel. Recommended phase II dose cohorts were expanded. Results: Fifty-eight patients were treated. Recommended phase II doses were 35 mg m -2 ombrabulin with 75 mg m -2 docetaxel (35/75 mg m -2; 13 patients) and 30 mg m -2 ombrabulin with 100 mg m -2 docetaxel (30/100 mg m -2; 16 patients). Dose-limiting toxicities were grade 3 fatigue (two patients; 42/75, 35/100), grade 3 neutropaenic infection (25/75), grade 3 headache (42/75), grade 4 febrile neutropaenia (30/100), and grade 3 thrombosis (35/100). Toxicities were consistent with each agent; mild nausea/vomiting, asthaenia/fatigue, alopecia, and anaemia were common, as were neutropaenia and leukopaenia. Diarrhoea, nail disorders and neurological symptoms were frequent at 100 mg m -2 docetaxel. Pharmacokinetic analyses did not show any relevant drug interactions. Ten patients had partial responses (seven at 30 mg m -2 ombrabulin), eight lasting >3 months. Conclusions: Sequential administration of ombrabulin with 75 or 100 mg m -2 docetaxel every 3 weeks is feasible

PrP Expression, PrPSc Accumulation and Innervation of Splenic Compartments in Sheep Experimentally Infected with Scrapie

BACKGROUND: In prion disease, the peripheral expression of PrP(C) is necessary for the transfer of infectivity to the central nervous system. The spleen is involved in neuroinvasion and neural dissemination in prion diseases but the nature of this involvement is not known. The present study undertook the investigation of the spatial relationship between sites of PrP(Sc) accumulation, localisation of nerve fibres and PrP(C) expression in the tissue compartments of the spleen of scrapie-inoculated and control sheep. METHODOLOGY/PRINCIPAL FINDINGS: Laser microdissection and quantitative PCR were used to determine PrP mRNA levels and results were compared with immunohistochemical protocols to distinguish PrP(C) and PrP(Sc) in tissue compartments of the spleen. In sheep experimentally infected with scrapie, the major sites of accumulation of PrP(Sc) in the spleen, namely the lymphoid nodules and the marginal zone, expressed low levels of PrP mRNA. Double immunohistochemical labelling for PrP(Sc) and the pan-nerve fibre marker, PGP, was used to evaluate the density of innervation of splenic tissue compartments and the intimacy of association between PrP(Sc) and nerves. Some nerve fibres were observed to accompany blood vessels into the PrP(Sc)-laden germinal centres. However, the close association between nerves and PrP(Sc) was most apparent in the marginal zone. Other sites of close association were adjacent to the wall of the central artery of PALS and the outer rim of germinal centres. CONCLUSIONS/SIGNIFICANCE: The findings suggest that the degree of PrP(Sc) accumulation does not depend on the expression level of PrP(C). Though several splenic compartments may contribute to neuroinvasion, the marginal zone may play a central role in being the compartment with most apparent association between nerves and PrP(Sc)

A new murine model of osteoblastic/osteolytic lesions from human androgen-resistant prostate cancer

BACKGROUND: Up to 80% of patients dying from prostate carcinoma have developed bone metastases that are incurable. Castration is commonly used to treat prostate cancer. Although the disease initially responds to androgen blockade strategies, it often becomes castration-resistant (CRPC for Castration Resistant Prostate Cancer). Most of the murine models of mixed lesions derived from prostate cancer cells are androgen sensitive. Thus, we established a new model of CRPC (androgen receptor (AR) negative) that causes mixed lesions in bone. METHODS: PC3 and its derived new cell clone PC3c cells were directly injected into the tibiae of SCID male mice. Tumor growth was analyzed by radiography and histology. Direct effects of conditioned medium of both cell lines were tested on osteoclasts, osteoblasts and osteocytes. RESULTS: We found that PC3c cells induced mixed lesions 10 weeks after intratibial injection. In vitro, PC3c conditioned medium was able to stimulate tartrate resistant acid phosphatase (TRAP)-positive osteoclasts. Osteoprotegerin (OPG) and endothelin-1 (ET1) were highly expressed by PC3c while dikkopf-1 (DKK1) expression was decreased. Finally, PC3c highly expressed bone associated markers osteopontin (OPN), Runx2, alkaline phosphatase (ALP), bone sialoprotein (BSP) and produced mineralized matrix in vitro in osteogenic conditions. CONCLUSIONS: We have established a new CRPC cell line as a useful system for modeling human metastatic prostate cancer which presents the mixed phenotype of bone metastases that is commonly observed in prostate cancer patients with advanced disease. This model will help to understand androgen-independent mechanisms involved in the progression of prostate cancer in bone and provides a preclinical model for testing the effects of new treatments for bone metastases