Using Tracker as a Pedagogical Tool for Understanding Projectile Motion

This paper reports the use of Tracker as a pedagogical tool in the effective learning and teaching of projectile motion in physics. When computer model building learning processes is supported and driven by video analysis data, this free Open Source Physics (OSP) tool can provide opportunities for students to engage in active inquiry-based learning. We discuss the pedagogical use of Tracker to address some common misconceptions of projectile motion by allowing students to test their hypothesis by juxtaposing their mental models against the analysis of real life videos. Initial research findings suggest that allowing learners to relate abstract physics concepts to real life through coupling computer modeling with traditional video analysis could be an innovative and effective way to learn projectile motion. 2015 Resources: http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/01-kinematics/174-projectile-motionComment: 9 pages, 9 figures; http://iopscience.iop.org/0031-9120/47/4/44

Ethnography of communication in the gay community in Singapore.

In Singapore, gays have been misunderstood by the public as a result of various factors: the law, misrepresentation of gays in the media, and the lack of communication between the gay community and the public. The result is a very subdued and suppressed gay community. This paper examines various aspects of life as a gay living in Singapore, and attempts to present an alternative representation of gays as compared to mainstream media. In particular, this paper examines how the gay forms his sexual identity, and how he communicates to his various publics: his family, friends, and the straight and gay communities. The methodology includes the use of in-depth interviews, past researches on gays and a video camera to probe into the various aspects of gay life. By combining both the techniques of anthropology film-making and cinematography, the short film presents a quasi-ethnographic study of the gay community in Singapore.Bachelor of Communication Studie

Hepatitis C virus mediated chronic inflammation and tumorigenesis in the humanised immune system and liver mouse model

<div><p>Hepatitis C is a liver disease caused by infection of the Hepatitis C virus (HCV). Many individuals infected by the virus are unable to resolve the viral infection and develop chronic hepatitis, which can lead to formation of liver cirrhosis and cancer. To understand better how initial HCV infections progress to chronic liver diseases, we characterised the long term pathogenic effects of HCV infections with the use of a humanised mouse model (HIL mice) we have previously established. Although HCV RNA could be detected in infected mice up to 9 weeks post infection, HCV infected mice developed increased incidences of liver fibrosis, granulomatous inflammation and tumour formation in the form of hepatocellular adenomas or hepatocellular carcinomas by 28 weeks post infection compared to uninfected mice. We also demonstrated that chronic liver inflammation in HCV infected mice was mediated by the human immune system, particularly by monocytes/macrophages and T cells which exhibited exhaustion phenotypes. In conclusion, HIL mice can recapitulate some of the clinical symptoms such as chronic inflammation, immune cell exhaustion and tumorigenesis seen in HCV patients. Our findings also suggest that persistence of HCV-associated liver disease appear to require initial infections of HCV and immune responses but not long term HCV viraemia.</p></div

Frequencies of liver abnormalities in HCV infected mice.

<p>Frequencies of liver abnormalities in HCV infected mice.</p

Human immune cell infiltration and inflammation in HCV infected HIL mice.

<p>Liver sections from (A-B) mock infected or (C-F) HCV infected HIL mice 27 weeks post infection were stained for human CD45 and counterstained with haematoxylin. Representative images showing (A) liver from mock infected HIL mice, (B) high magnification of an area in mock infected mice (Squared region), (C) liver from HCV infected HIL mice, (D-E) high magnification of areas in a hepatocellular adenoma from HCV infected mice, and (F) high magnification of an area in a non-tumour region from HCV infected mice. (G-I) Representative images showing human (G) CD68, (H) CD3 and (I) CD20 stains within hepatocellular adenoma in HCV infected mice. (J-K) Plasma samples at 27–28 weeks post infection were quantified for the presence of human cytokines: (J) IL10, IL12p70, IL17A, IL23 (K) MCP-1, IL6, IL8, IL18 and IFN-γ. Mock n = 10, 10⁶ ffu HCV n = 5, 10⁷ ffu HCV n = 16.</p

Majority of dividing cells in liver tumours are of human origin.

<p>(A-C) H&E stain of a hepatocellular adenoma containing liver section. (B&C) Nodular growth, loss of normal architecture with irregular growth pattern and compression of the surrounding parenchyma. (D-F) Serial section stained using an antibody specific against HSA showing 80–90% human albumin positivity within the liver tumours. (G) HSA expressing hepatocytes of mock (n = 3), non-tumour (n = 2) and tumour (n = 2) regions within liver sections were counted and expressed as a percentage of total hepatocytes. Percentages represent averaged counts of HSA expressing hepatocytes against total hepatocytes from five randomly selected 500 x 250 μm regions per sample. Error bars represent standard error of the means. (H-I) Representative images of mitotically active hepatocytes that (H) express HSA or (I) do not express HSA.</p

Liver abnormalities detected in HCV infected mice at 27 weeks post infection.

<p>(A-H) Livers were harvested from mice in the mock and HCV infected groups, paraffin-embedded and processed for staining with (B-G) haematoxylin and eosin or (H) Sirius red/fast green stains. (A) Representative image showing gross appearance of livers obtained from either mock or HCV infected mice at 27–28 weeks post infection. Representative image of H&E stains showing (B) normal liver from mock infected mice and (C) steatosis, (D) hepatocellular adenoma, (E) hepatocellular carcinoma, (F) granulomatous inflammation, (G) focal nodular hyperplasia and (H) liver fibrosis from livers harvested from HCV infected mice.</p

Deposition of human T cells and macrophages in non-tumour and tumour regions in the livers of HCV infected HIL mice.

<p>Livers sections from mock infected and HCV infected HIL mice 27 weeks post infection were stained for human CD3, PD1, CD68, IL6 and IL10. Representative images are shown for the stains of (A) CD3 and PD1, (B) CD68 and IL6 and (C) CD68 and IL10. Scale bars represent 50 μM. (D) Total number of CD3⁺PD1⁺, CD68⁺IL6⁺ or CD68⁺IL10⁺ cells were counted from five randomly selected 310 x 310 μm regions from mock liver sections, non-tumour or tumour regions from HCV infected HIL mice. Error bars represent standard error of the means.</p

Human immune cell composition and phenotyping in HCV infected HIL mice.

<p>Leukocytes were prepared from livers and spleens of mock infected or mice infected with 10⁷ ffu of HCV 27 weeks post infection and analysed by flow cytometry. Shown are absolute numbers of various immune cell populations in (A) livers or (B) spleens of mock or HCV infected mice. Error bars represent standard error of the means. Mock n = 5, 10⁷ ffu HCV n = 12.</p

Global haemostatic tests demonstrate the absence of parameters of hypercoagulability in non-hypoxic mild COVID-19 patients: a prospective matched study

10.1007/s11239-021-02575-4JOURNAL OF THROMBOSIS AND THROMBOLYSI