Milliamperage-seconds, kilovoltage and patient dose in computed radiography

Radiographic techniques were applied to a human simulation pelvis phantom with evaluations of the resultant image analyzed by a designated radiologist. Results indicate that a lower patient dose is received when coupled with an increase in the tube voltage. Images analyzed demonstrated little noise variation between images, which indicates the ability to lower patient dose while maintaining quality images

What Does “Sustainable Development” Mean?

A recurring theme throughout the EnviroLab Asia clinic trip to Singapore and Malaysian Borneo was the concept of sustainable development. In this essay, I explore my own thoughts and concerns regarding this phrase, such as the tension that exists between sustainability (the maintenance of resources) and the conventional concept of development (which consumes resources and can often wreak environmental destruction). I reflect on this tension within the context of environmental issues faced by the Dayak people in Sarawak--the building of the Baram Dam, and the prevalence of oil palm plantations

Rachel Carson: Humanizing Nature

Rachel Carson was instrumental in changing the way the world viewed conservation. Her initial written works demonstrated the idea that humans were not the center of the earth’s ecosystems by describing the environment from the viewpoint of non-human creatures (Cafaro, 2011, para. 45-48). Carson’s most eminent publication, Silent Spring, was released at the beginning of the 1960s (Cafaro, 2011, para. 25). The book advocated Carson’s concept of enlightened anthropocentrism through the insistence that new scientific innovations should be questioned as to why, whether, and for what purpose they are put into practice (Walker & Walsh, 2012, p.19). Another issue sparked by Silent Spring regarded whether humans should alter nature for our purposes or attempt to leave it unchanged (Cafaro, 2011, para. 67). Silent Spring helped to spark a national debate about scientific responsibility, limitations on advances in technology, and chemical pesticides in general (Lear, 2013, p. 1). The fact that her arguments stimulated such intense discussion is a testimony to how influential she truly was. Furthermore, Silent Spring led to the banning of dichlorodiphenyltricholoroethane (DDT) production by 1972, along with the implementation of government regulations to safeguard the environment (Hecht, 2012, p. 154; Lear, 2013, p. 1). Carson also made individuals realize that what they put into the environment must be regulated in order to keep the effects from haunting them for generations to come. This undeniable truth continues to resonate today.

Matrix Model Analysis of a Coastal Northern California Subpopulation of the Western Snowy Plover (\u3cem\u3eCharadrius alexandrinus nivosus\u3c/em\u3e)

Shorebirds are increasingly threatened by introduced predators, invasive grasses, and human disturbance. Matrix models can be used to predict population growth and assess management options. The Pacific coast population of the western snowy plover, Charadrius alexandrinus nivosus, is listed as threatened under the Endangered Species Act, largely due to high rates of nest predation. A matrix model for the entire Pacific coast metapopulation of western snowy plovers was published in 1999 by Nur et al., but population growth has not been comprehensively reassessed since, even after development of a recovery plan (USFWS 2007) and extensive management intervention. I built and analyzed a matrix model for one subpopulation of western snowy plovers previously considered a sink habitat—Recovery Unit 2 in northern California, comprising Humboldt, Mendocino, and Del Norte counties. Based on my model, growth rate (lambda) is 1.05—countering a previous finding that Recovery Unit 2 is a sink—compared to 1.036 for the Nur et al. (1999) metapopulation model. I found that sensitivities and elasticities for each vital rate were similar between the two models; adult survival had the greatest effect on lambda, followed by juvenile survival, and fecundity had the least effect. Even though fecundity was lower for my model than Nur et al.’s (1999), adult survival was higher, which had a larger impact on population growth. In terms of management strategies, predator control, habitat restoration, and restriction of human activity should continue as outlined in the recovery plan, so as to continue the trend of positive growth for the coastal breeding population. Future directions involve performing population viability analyses for other recovery units to reassess the state of western snowy plovers compared to 1999

Depression

Health Issue: Depression causes significant distress or impairment in physical, social, occupational and other key areas of functioning. Women are approximately twice as likely as men to experience depression. Psychosocial factors likely mediate the risks for depression incurred by biological influences. Key Findings: Data from the 1999 National Population Health Survey show that depression is more common among Canadian women, with an annual self-reported incidence of 5.7 % compared with 2.9 % in men. The highest rates of depression are seen among women of reproductive age. Predictive factors for depression include previous depression, feeling out of control or overwhelmed, chronic health problems, traumatic events in childhood or young adulthood, lack of emotional support, lone parenthood, and low sense of mastery. Although depression is treatable, only 43 % of depressed women had consulted a health professional in 1998/99 and only 32.4 % wer

The Effect of Histone Deacetylase Inhibitors on Metastatic Breast Cancer Cells in Conjunction with Clinically Relevant Chemotherapeutic Agents

Histone Deacetylases (HDACs) are enzymes charged with the job of loosening DNA packaged around histone proteins. This gives them the opportunity to affect the transcriptional regulation of certain cancer associated genes and proteins, but HDACs are not limited to only DNA modification. They also target non-chromatin proteins in the cytoplasm, and have been closely linked to the many pathways involved in metastatic breast cancer such as apoptosis evasion, cell migration, and angiogenesis. HDAC’s effect on important cytoplasmic proteins could play a huge role in the largely unknown mechanisms of metastatic breast cancer. HDAC inhibitors are a rising class of chemotherapeutic agents. In this research, HDAC inhibitors selective for cytoplasmic target proteins are used in conjunction with nuclear based HDAC inhibitors and known microtubule stabilizers and destabilizers to test and explore the effects of HDAC inhibition on MDA-MB-231-derived metastatic breast cancer cell lines BoM-1833 (BoM) and LM-4175 (LM), and in MCF-7-derived metastatic breast cancer cell line MCF-7 BoM. Through viability, clonogenic, and combination assays, the HDAC inhibitors were not found to have complete inhibition of the tumor cells at any of the tested concentrations but show a trend suggesting potential effects on tumor inhibition at higher concentrations. There is also some evidence supporting a potential significance of HDAC inhibitors on ER+ breast cancer cells. Clonogenic assays upheld the inhibitory results of HDAC inhibitors on metastatic breast cancer cells, and emphasized the increased effectiveness of higher concentrations of HDAC inhibitors. Combination assays showed a trend towards antagonistic effects between HDAC inhibitors and microtubule stabilizes

Crinoids from the Silica Shale, Devonian, of Ohio

Author Institution: Department of Geology, Ohio State Universit

Additional Species from the Silica Shale of Lucas County, Ohio

Author Institution: Department of Geology, Ohio State Universit