Surprisingly, not only atoms prefer to form crystals. For a system of polymer-like chains of particles, the best way to maximize entropy is letting them form crystal structures as well. Manuel Laso and his team at the Technical University of Madrid reported the finding in the 24th July Physical Review Letter.
Hello readers! Welcome to JYI's first Book Review, our latest addition to the News and Features Department designed to quench the thirst for knowledge that ails you, the science undergraduate. With these book reviews, we will be occasionally highlighting a particularly interesting book with a topic in science. We will be providing a synopsis of the book, reviewing the details, providing personal insight from the author on his/her inspiration for the book, and ending with a comprehensive review. Whether searching for the perfect book for your science project, looking to further your knowledge in a particular subject, or just looking for a good read, JYI's Book Reviews will serve you well as an undergraduate pursuer of knowledge.
Concentrations of polychlorinated biphenyls (PCBs), a group of compounds known to be carcinogenic, in water and fish samples were studied in the Houston Ship Channel and Galveston Bay to determine a bioaccumulation factor (BAF, measured in L/kg lipid) for common fish species. The United States Environmental Protection Agency (USEPA) employs the use of a simple BAF parameter in water quality regulation. The objective of the study was to test the validity of this assumption. Water PCB concentration was found using a high-volume sampling technique, where suspended and dissolved PCBs were captured using 1 µm Glass Fiber Filters (GFFs) and XAD-2 resin columns, respectively. Hardhead Catfish (n=21 samples for 2008 study, n=68 samples for 2002 study) and Atlantic Croaker (n=14 samples for 2008 study) were filleted for tissue analysis. A general decline in PCB levels from 2002-2003 to 2008 across all media was found in the studied area. In the 2008 study, 96% (n=25) of the stations sampled exceeded the PCB standard for fish tissue and/or water, set by Texas Department of State Health Services (TDSHS) and Texas Commission on Environmental Quality (TCEQ). A strong linear correlation was found between total water concentration and the lipid-normalized tissue concentration of PCBs in Atlantic Croaker (R2=0.696, p<0.05), while no correlation was found for PCB content in tissues obtained from Hardhead Catfish (R2=0.022, p=0.563). The BAF values calculated for the Atlantic Croaker had a lower mean and smaller range (2.41·106, 1.19·106-4.12·106), in comparison to those calculated for the Hardhead Catfish (7.02·106, 8.50·105-5.82·107) in the 2008 data set. This correlated with 2002-2003 study results for BAF in Hardhead Catfish (5.65·106, 5.37·105-3.04·107). No correlation (R2=0.0029, p=0.862) was found between the BAF of Atlantic Croaker and Hardhead Catfish at the common sampling sites in the 2008 study. We found that a linear statistical model was not suitable for determining a BAF that can accurately predict fish tissue concentration from water concentration, or vice versa, for both species.
One of the most difficult obstacles for cancer researchers to overcome in the past several decades has been the development of methods to detect cancerous cells. If such a method could be perfected, diseased cells could be easily identified and treated. What would this mean for cancer patients? Could this help doctors move closer to finding a "cure for cancer"? The answers to these questions are being explored by Dr. Issa A. Katime and his research team at the Department of Physical Chemistry at the University of the Basque Country (UPV/EHU).
India accounts for nearly 20% of maternal and child health services in the globe. This could be related to several factors such as non utilization or under utilization of maternal and child health (MCH) services. For proper programme implementation, understanding community knowledge and practices regarding maternal care during pregnancy, delivery, and postnatal period is required. To assess the utilization of MCH services, a cross sectional community based study was conducted in a sub-centre area of the Udupi District. A pre-tested questionnaire was administered to 185 recently delivered mothers and the data analyzed using SPSS (version 13.0) package. 90% of the women had at least 3 antenatal visits and 96% of them had institutional deliveries. 89% of the women were aware of the different contraceptive methods available. Around 37% of the under-fives were malnourished. Despite the findings, improving community awareness on maternal and child health (MCH) services is still required.