Phylogenetically Clustered Extinction Risks Do Not Substantially Prune the Tree of Life

Anthropogenic activities have increased the rate of biological extinction many-fold. Recent empirical studies suggest that projected extinction may lead to extensive loss to the Tree of Life, much more than if extinction were random. One suggested cause is that extinction risk is heritable (phylogenetically patterned), such that entire higher groups will be lost. We show here with simulation that phylogenetically clustered extinction risks are necessary but not sufficient for the extensive loss of phylogenetic diversity (PD) compared to random extinction. We simulated Yule trees and evolved extinction risks at various levels of heritability (measured using Pagel\u27s ). At most levels of heritability ( in range of 0 to 10), mean values of extinction risk (range 0.25 to 0.75), tree sizes (64 to 128 tips), tree balance and temporal heterogeneity of diversification rates (Yule and coalescent trees), extinction risks do not substantially increase the loss of PD in these trees when compared to random extinction. The maximum loss of PD (20% above random) was only associated with the combination of extremely excessive values of phylogenetic signal, high mean species\u27 extinction probabilities, and extreme (coalescent) tree shapes. Interestingly, we also observed a decline in the rate of increase in the loss of PD at high phylogenetic clustering of extinction risks. Our results suggest that the interplay between various aspects of tree shape and a predisposition of higher extinction risks in species-poor clades is required to explain the substantial pruning of the Tree of Life

Coronary thrombosis: a study of 128 cases with special reference to its relationship to angina pectoris

It is observed from this study that angina pectoris and coronary thrombosis are the different phases of the same process being caused by anoxaemia of heart muscle. The underlying factor in both the conditions 154. excluding the precipitating factors is the same i.e. atherosclerosis of coronary arteries Atheromatous changes in angina pectoris however are more or less of a uniform nature, resulting usually in narrowing of the lumen of these vessels, whereas in coronary thrombosis the changes are generally of a patchy type with or without much narrowing of the caliber of coronary arteries. The precipitating factors no doubt are different, but while coronary thrombosis is caused in a person with Sclerotic coronary arteries at rest, Angina pectoris results in the same individual in excitement and with exertion

Assessment of Micronuclei Frequency in Individuals with a Habit of Tobacco Chewing by Means of Exfoliated Oral Buccal Cells

INTRODUCTION: Majority of cancers are diagnosed at an advanced stage resulting in poor prognosis and survival rates among patients. Hence early diagnosis of oral cancers seems to be the need of the hour. Analysis of exfoliated buccal cell micronuclei (MN) is a sensitive method of monitoring genetic damage. AIM: The present study has been carried out with an objective to evaluate the genotoxic effects of tobacco chewing by means of micronucleus assay in exfoliated cells of buccal mucosa.MATERIALS AND METHOD: This cross sectional study was carried out in Department of Oral Pathology, Swami Devi Dyal Hospital And Dental College, Golpura, Barwala, Panchkula. The study population comprised of a total of 50 subjects, divided into five groups: Group 1comprising of 10 age and sex matched healthy subjects without any habits as controls, Group 2 comprising of 10 subjects with a history of chewing tobacco. Group 3 comprising of 10 subjects with a history of chewing tobacco and cigarette smoking, Group 4 comprising of 10 subjects with a history of chewing tobacco and drinking and Group 5 comprising of 10 subjects with a history of chewing tobacco, smoking and drinking. Oral exfoliated cells were obtained from buccal mucosa of the subjects, slides were prepared from each subject stained with stain respectively.RESULTS: The mean numbers of micronuclei in group 1 were 7.86±6.7, Group 2 were 63.37±10.01, Group 3 were 65.49±12.32, Group 4 were 68.22±11.11 and Group 5 were 69.43±10.71. On comparison we observed that the difference in Mean micronuclei frequency among all the 5 study groups came to be statistically also highly significant (p<0.0001*)CONCLUSION: Micronuclei assay is an effective tool that reflects severity of disease. Even though tobacco induced cancers are preventable, banning the use of tobacco has not been possible for social and political reasons

Culturally relevant pedagogy redux: Canadian teachers’ conceptions of their work and its challenges

This study examined how teachers who practice culturally relevant pedagogy describe their work and its challenges. Data is from ten semi-structured interviews with teachers in Vancouver Canada. Analysis revealed four themes in relation to participants' practice to support culturally diverse students: 1) An inclusive classroom of meaningful student-teacher relationships, collaborative learning, and a respectful classroom climate; 2) Expanded conception of the curriculum that validates students' cultures, develop critical consciousness and agency; 3) A resource team including families and support workers; 4) Purposeful renewal of knowledge via research and professional development. In addition, participants described institutional barriers common to their practice

A Study Assessing Gender Distribution Using Maxillary Sinus

INTRODUCTION: Corpse recognition is a difficult procedure. Comparison of both ante mortem and post-mortem records is essential and assists in identification of corpses. Typical methods of identification however sometimes may be inconclusive. Gender determination is an important aspect in identification of corpses. Previously skull, pelvis and the long bones have been used in gender determination. It has been reported earlier that maxillary sinus remains intact even when skull and long bones may be badly disfigured in incarnated victims.AIM: The aim of this study was to examine whether the measurements of the maxillary sinuses may possibly be used for gender determination.MATERIAL AND METHODS: Computed tomography scans of total of 50 Adults patients within the age range of 25 to 65 years from the previous dental records were taken. Sample comprised of 25 (50%) males and 25 (50%) females. The width, height and length was measured in all cases using CT images.RESULTS: Maxillary sinus exhibits anatomic variability between genders. A significant difference in the length and height of maxillary sinus was observed with respect to males and females. (p<0.005)CONCLUSION: We conclude from the present study that the height and length of maxillary sinuses together with other bones can be used for gender determination when skeleton is not available

A lifeline for all: children and families with no recourse to public funds

There are thousands of children in the UK facing deep, long-term poverty because of strict immigration rules, which mean their families cannot access mainstream benefits or vital support, even in a crisis. In this report we focus on the experiences of families who are affected by NRPF conditions and make a series of recommendations for policy, practice and further research

Plate Pouring IV

From a high school biology class to a small research facility, this machine will cheaply (relative to its competitors) automatically pour a layer of agar into a large number of Petri dishes in order to grow bacteria micro-cultures. Designed to be powered within a fume hood, the user simply needs to open up the containment facility, insert stacks of Petri dishes, and pour in a batch of premade agar. Within the hour, approximately 120 Petri dishes should be layered and ready for further experimentation