TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: Lung cancer is the most important cause of cancer mortality worldwide, but the underlying mechanisms of this disease are not fully understood. Copy number variations (CNVs) are promising genetic variations to study because of their potential effects on cancer.', 'Here we conducted a pilot study in which we systematically analyzed the association of CNVs in two lung cancer datasets: the Environment And Genetics in Lung cancer Etiology (EAGLE) and the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial datasets. We used a preestablished association method to test the datasets separately and conducted a combined analysis to test the association accordance between the two datasets. Finally, we identified 167 risk SNP loci and 22 CNVs associated with lung cancer and linked them with recombination hotspots. Functional annotation and biological relevance analyses implied that some of our predicted risk loci were supported by other studies and might be potential candidate loci for lung cancer studies.\Question: Does combined analysis with copy number variation identify risk loci in lung cancer?

SOLUTION: Our results further emphasized the importance of copy number variations in cancer and might be a valuable complement to current genome-wide association studies on cancer.

PROBLEM: Context: To ascertain the prevalence of psychiatric symptoms and substance use disorders among adolescents with a lifetime history of foster care placement, using data from a nationally representative sample of U.S. adolescents.', 'We studied adolescents aged 12-17 years in the public use file of the 2000 National Household on Drug Abuse (n = 19,430, including 464 adolescents with history of foster care placement). Psychiatric symptoms and substance use disorders were ascertained through direct interviewing of adolescents. Logistic regression analyses were used to estimate the odds of past-year psychiatric symptoms and substance use disorders among adolescents involved with foster care, as compared to those without a lifetime history of foster care placement (comparison group).', 'Adolescents involved with foster care had more past-year psychiatric symptoms, and especially more conduct symptoms, and past-year substance use disorders than those never placed in foster care. Adolescents involved with foster care were about four times more likely to have attempted suicide in the preceding 12 months (adjusted odds ratio [AOR] 3.95; 95% confidence interval [CI] 2.78, 5.61), and about five times more likely to receive a drug dependence diagnosis in the same period (AOR 4.81; 95% CI 3.22, 7.18).\Question: Do psychiatric symptoms and substance use disorders in a nationally representative sample of American adolescents involved with foster care?

SOLUTION: Adolescents involved with foster care have a higher prevalence of psychiatric symptoms and drug use disorders than those never placed in foster care. Additionally, the results of this study suggest that they may be at elevated risk for suicide attempts.

PROBLEM: Context: Displacement Encoding with Stimulated Echoes (DENSE) encodes displacement into the phase of the magnetic resonance signal. The encoding frequency (ke) maps the measured phase to tissue displacement while the strength of the encoding gradients affects image quality. 2D cine DENSE studies have used a ke of 0.10cycles/mm, which is high enough to remove an artifact-generating echo from k-space, provide high sensitivity to tissue displacements, and dephase the blood pool. However, through-plane dephasing can remove the unwanted echo and dephase the blood pool without relying on high ke. Additionally, the high sensitivity comes with the costs of increased phase wrapping and intra-voxel dephasing. We hypothesized that ke below 0.10cycles/mm can be used to improve image characteristics and provide accurate measures of cardiac mechanics.', 'Spiral cine DENSE images were obtained for 10 healthy subjects and 10 patients with a history of heart disease on a 3T Siemens Trio. A mid-ventricular short-axis image was acquired with different ke: 0.02, 0.04, 0.06, 0.08, and 0.10cycles/mm. Peak twist, circumferential strain, and radial strain were compared between acquisitions employing different ke using Bland-Altman analyses and coefficients of variation. The percentage of wrapped pixels in the phase images at end-systole was calculated for each ke. The dephasing of the blood signal and signal to noise ratio (SNR) were also calculated and compared.', 'Negligible differences were seen in strains and twist for all ke between 0.04 and 0.10cycles/mm. These differences were of the same magnitude as inter-test differences. Specifically, the acquisitions with 0.04cycles/mm accurately quantified cardiac mechanics and had zero phase wrapping. Compared to 0.10cycles/mm, the acquisitions with 0.04cycles/mm had 9% greater SNR and negligible differences in blood pool dephasing.\Question: Does 2D cine DENSE with low encoding frequencies accurately quantify cardiac mechanics with improved image characteristics?

SOLUTION:
For 2D cine DENSE with through-plane dephasing, the encoding frequency can be lowered to 0.04cycles/mm without compromising the quantification of twist or strain. The amount of wrapping can be reduced with this lower value to greatly simplify the input to unwrapping algorithms. The strain and twist results from studies using different encoding frequencies can be directly compared.