Comparison of five different methods to assess the concentration of boar semen

Both for research and practical purposes, accurate and repeatable methods are required to assess the concentration of boar semen samples. Since the method which is used may influence the results considerably, the aim of the present study was to compare 5 frequently used techniques to determine boar semen concentration. Fifty ejaculates were collected from 37 different boars at an artificial insemination centre. Subsequently, each ejaculate was analyzed for sperm concentration by means of 2 different types of colorimeters (Colorimeter 1: Model 252, Sherwood Scientific Ltd, Cambridge, UK; Colorimeter 2: Ciba-Corning, Schippers, Bladel, The Netherlands), the Burker counting chamber (golden standard), and the Hamilton Thorne Analyzer (Ceros 42.1) using 2 types of Leja chambers (the 'former' and the 'recently developed'). Each ejaculate was assessed 5 times with each of the 5 methods, and the repeatability, expressed by coefficient of variation (CV), was determined for each method. The different methods were compared using Pearson's correlations and limits of agreement. The colorimeters yielded the lowest CV's (both 3.7%), while the former Leja chamber resulted in the highest CV (12.4%). Moreover, significant (P0.71) were found between the results obtained by the different methods. The limits of agreement plots showed that none of the methods consistently over- or underestimated the sperm concentrations when compared to the Burker chamber, although there was a tendency toward higher over- or underestimation in highly concentrated sperm samples. Based on our results, there were no major differences in the assessment of sperm concentration between the evaluated methods. The choice of method used in a laboratory could therefore be based on factors such as cost, number of samples to be assessed and practical use, without thereby negatively affecting the validity of the results thus obtained

Utilizing the “Plan, Do, Study, Act” Framework to Explore the Process of Curricular Assessment and Redesign in a Physical Therapy Education Program in Suriname

Purpose: To describe how a multinational team worked together to transition a physical therapy (PT) educational program in Paramaribo, Suriname, from a Bachelor level to a Master of Science in Physical Therapy (MSPT) level. The team was made up of PT faculty from Anton De Kom Universiteit van Suriname (AdeKUS), the Flemish Interuniversity Council University Development Cooperation (VLIR-UOS) leadership, and Health Volunteers Overseas volunteers. In this case study, the process for curricular assessment, redesign, and upgrade is described retrospectively using a Plan, Do, Study, Act (PDSA) framework. Method: PT educational programs in developing countries are eager for upgrade to meet international expectations and to better meet community health-care needs. An ongoing process which included baseline assessment of all aspects of the existing bachelor's program in PT, development of a plan for a MSPT, implementation of the master's program, and evaluation following implementation is described. Conclusion: Curricular assessment and upgrade in resource limited countries requires the implementation of process-oriented methods. The PDSA process is a useful tool to explore curricular development. The international collaboration described in this paper provides an example of the diligence, consistency, and dedication required to see a project through and achieve success while providing adequate support to the host site. This project might provide valuable insights for those involved in curricular redesign in similar settings

Comparison of primary virus isolation in pulmonary alveolar macrophages and four different continuous cell lines for type 1 and type 2 porcine reproductive and respiratory syndrome virus

Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) has a highly restricted cellular tropism. In vivo, the virus primarily infects tissue-specific macrophages in the nose, lungs, tonsils, and pharyngeal lymphoid tissues. In vitro however, the MARC-145 cell line is one of the few PRRSV susceptible cell lines that are routinely used for in vitro propagation. Previously, several PRRSV non-permissive cell lines were shown to become susceptible to PRRSV infection upon expression of recombinant entry receptors (e.g., PK15Sn-CD163, PK15S10-CD163). In the present study, we examined the suitability of different cell lines as a possible replacement of primary pulmonary alveolar macrophages (PAM) cells for isolation and growth of PRRSV. The susceptibility of four different cell lines (PK15Sn-CD163, PK15S10-CD163, MARC-145, and MARC-145Sn) for the primary isolation of PRRSV from PCR positive sera (both PRRSV1 and PRRSV2) was compared with that of PAM. To find possible correlations between the cell tropism and the viral genotype, 54 field samples were sequenced, and amino acid residues potentially associated with the cell tropism were identified. Regarding the virus titers obtained with the five different cell types, PAM gave the highest mean virus titers followed by PK15Sn-CD163, PK15S10-CD163, MARC-145Sn, and MARC-145. The titers in PK15Sn-CD163 and PK15S10-CD163 cells were significantly correlated with virus titers in PAM for both PRRSV1 (p < 0.001) and PRRSV2 (p < 0.001) compared with MARC-145Sn (PRRSV1: p = 0.22 and PRRSV2: p = 0.03) and MARC-145 (PRRSV1: p = 0.04 and PRRSV2: p = 0.12). Further, a possible correlation between cell tropism and viral genotype was assessed using PRRSV whole genome sequences in a Genome-Wide-Association Study (GWAS). The structural protein residues GP2:187L and N:28R within PRRSV2 sequences were associated with their growth in MARC-145. The GP5:78I residue for PRRSV2 and the Nsp11:155F residue for PRRSV1 was linked to a higher replication on PAM. In conclusion, PK15Sn-CD163 and PK15S10-CD163 cells are phenotypically closely related to the in vivo target macrophages and are more suitable for virus isolation and titration than MARC-145/MARC-145Sn cells. The residues of PRRSV proteins that are potentially related with cell tropism will be further investigated in the future

Copernic et Galilée en tant que lecteurs de Platon

Analyse critique de :&#x0D; De Pace (Anna), Galileo lettore di Copernico. – Firenze : Olschki, 2020. – xlii, 638 p. – 1 vol. broché de 17 × 24 cm. – 50,00 €. – isbn 978-8822267115.</jats:p