933,279 research outputs found
Statistical properties of inelastic Lorentz gas
The inelastic Lorentz gas in cooling states is studied. It is found that the
inelastic Lorentz gas is localized and that the mean square displacement of the
inelastic Lorentz gas obeys a power of a logarithmic function of time. It is
also found that the scaled position distribution of the inelastic Lorentz gas
has an exponential tail, while the distribution is close to the Gaussian near
the peak. Using a random walk model, we derive an analytical expression of the
mean square displacement as a function of time and the restitution coefficient,
which well agrees with the data of our simulation. The exponential tail of the
scaled position distribution function is also obtained by the method of
steepest descent.Comment: 31pages,9figures, to appear Journal of Physical Society of Japan
Vol.70 No.7 (2001
Two variants on T2DM susceptible gene HHEX are associated with CRC risk in a Chinese population
Increasing amounts of evidence has demonstrated that T2DM (Type 2 Diabetes Mellitus) patients have increased susceptibility to CRC (colorectal cancer). As HHEX is a recognized susceptibility gene in T2DM, this work was focused on two SNPs in HHEX, rs1111875 and rs7923837, to study their association with CRC. T2DM patients without CRC (T2DM-only, n=300), T2DM with CRC (T2DM/CRC, n=135), cancer-free controls (Control, n=570), and CRC without T2DM (CRC-only, n=642) cases were enrolled. DNA samples were extracted from the peripheral blood leukocytes of the patients and sequenced by direct sequencing. The χ(2) test was used to compare categorical data. We found that in T2DM patients, rs1111875 but not the rs7923837 in HHEX gene was associated with the occurrence of CRC (p= 0.006). for rs1111875, TC/CC patients had an increased risk of CRC (p=0.019, OR=1.592, 95%CI=1.046-2.423). Moreover, our results also indicated that the two variants of HEEX gene could be risk factors for CRC in general population, independent on T2DM (p< 0.001 for rs1111875, p=0.001 for rs7923837). For rs1111875, increased risk of CRC was observed in TC or TC/CC than CC individuals (p<0.001, OR= 1.780, 95%CI= 1.385-2.287; p<0.001, OR= 1.695, 95%CI= 1.335-2.152). For rs7923837, increased CRC risk was observed in AG, GG, and AG/GG than AA individuals (p< 0.001, OR= 1.520, 95%CI= 1.200-1.924; p=0.036, OR= 1.739, 95%CI= 0.989-3.058; p< 0.001, OR= 1.540, 95%CI= 1.225-1.936). This finding highlights the potentially functional alteration with HHEX rs1111875 and rs7923837 polymorphisms may increase CRC susceptibility. Risk effects and the functional impact of these polymorphisms need further validation
Clover Root Curculio Injury and Abundance in Minnesota Alfalfa of Different Stand Age
Root injury and midsummer adult abundance of clover root curculio (CRC), Sitona hispidulus (Fabricius), was surveyed in 24 different aged southeastern Minnesota alfalfa fields. CRC presence was not detected in first year fields 2-3 months following stand establishment. Increased root scarring was observed as stand age increased and most fields 3-5 years old showed heavy CRC root scarring. High CRC adult popUlations and widespread root scarring was found in second year alfalfa fields which suggests that CRC is a mobile insect capable of rapidly colonizing new plantings
Usefulness and Usability of a Personal Health Record and Survivorship Care Plan for Colorectal Cancer Survivors: Survey Study
Background: As a result of improvements in cancer screening, treatment, and supportive care, nearly two-thirds of individuals diagnosed with colorectal cancer (CRC) live for 5 years after diagnosis. An ever-increasing population of CRC survivors creates a need for effective survivorship care to help manage and mitigate the impact of CRC and its treatment. Personal health records (PHRs) and survivorship care plans provide a means of supporting the long-term care of cancer survivors.
Objective: The purpose of this study is to characterize the usefulness of a CRC PHR and survivorship care plan and to describe the usability of these technologies in a population of CRC survivors. To our knowledge, this is the first study to assess a PHR and survivorship care plan specifically targeting CRC survivors.
Methods: Twenty-two patients with CRC were recruited from surgery clinics of an academic medical center and Veterans Affairs hospital in Indianapolis and provided access to an online Colorectal Cancer Survivor’s Personal Health Record (CRCS-PHR). Survey data were collected to characterize the usefulness of the CRCS-PHR and describe its usability in a population of CRC survivors. CRC survivors were surveyed 6 months after being provided online access. Means and proportions were used to describe the usefulness and ease of using the CRC website. Open-ended questions were qualitatively coded using the constant comparative method.
Results: CRC survivors perceived features related to their health care (ie, summary of cancer treatment history, follow-up care schedule, description of side effects, and list of community resources) to be more useful than communication features (ie, creating online relationships with family members or caregivers, communicating with doctor, and secure messages). CRC survivors typically described utilizing traditional channels (eg, via telephone or in person) to communicate with their health care provider. Participants had overall positive perceptions with respect to ease of use and overall satisfaction. Major challenges experienced by participants included barriers to system log-in, lack of computer literacy or experience, and difficulty entering their patient information.
Conclusions: For CRC, survivors may find the greater value in a PHR’s medical content than the communication functions, which they have available elsewhere. These findings regarding the usefulness and usability of a PHR for the management of CRC survivorship provide valuable insights into how best to tailor these technologies to patients’ needs. These findings can inform future design and development of PHRs for purposes of both cancer and chronic disease management
Convolutional-Code-Specific CRC Code Design
Cyclic redundancy check (CRC) codes check if a codeword is correctly
received. This paper presents an algorithm to design CRC codes that are
optimized for the code-specific error behavior of a specified feedforward
convolutional code. The algorithm utilizes two distinct approaches to computing
undetected error probability of a CRC code used with a specific convolutional
code. The first approach enumerates the error patterns of the convolutional
code and tests if each of them is detectable. The second approach reduces
complexity significantly by exploiting the equivalence of the undetected error
probability to the frame error rate of an equivalent catastrophic convolutional
code. The error events of the equivalent convolutional code are exactly the
undetectable errors for the original concatenation of CRC and convolutional
codes. This simplifies the computation because error patterns do not need to be
individually checked for detectability. As an example, we optimize CRC codes
for a commonly used 64-state convolutional code for information length k=1024
demonstrating significant reduction in undetected error probability compared to
the existing CRC codes with the same degrees. For a fixed target undetected
error probability, the optimized CRC codes typically require 2 fewer bits.Comment: 12 pages, 8 figures, journal pape
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Functional Effects of let-7g Expression in Colon Cancer Metastasis.
MicroRNA regulation is crucial for gene expression and cell functions. It has been linked to tumorigenesis, development and metastasis in colorectal cancer (CRC). Recently, the let-7 family has been identified as a tumor suppressor in different types of cancers. However, the function of the let-7 family in CRC metastasis has not been fully investigated. Here, we focused on analyzing the role of let-7g in CRC. The Cancer Genome Atlas (TCGA) genomic datasets of CRC and detailed data from a Taiwanese CRC cohort were applied to study the expression pattern of let-7g. In addition, in vitro as well as in vivo studies have been performed to uncover the effects of let-7g on CRC. We found that the expression of let-7g was significantly lower in CRC specimens. Our results further supported the inhibitory effects of let-7g on CRC cell migration, invasion and extracellular calcium influx through store-operated calcium channels. We report a critical role for let-7g in the pathogenesis of CRC and suggest let-7g as a potential therapeutic target for CRC treatment
Mechanisms linking colorectal cancer to the consumption of (processed) red meat : a review
Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world. The vast majority of CRC cases have been linked to environmental causes rather than to heritable genetic changes. Over the last decades, epidemiological evidence linking the consumption of red and, more convincingly, of processed red meat to CRC has accumulated. In parallel, hypotheses on carcinogenic mechanisms underlying an association between CRC and the intake of red and processed red meat have been proposed and investigated in biological studies. The hypotheses that have received most attention until now include (1) the presence of polycyclic aromatic hydrocarbons and heterocyclic aromatic amines, two groups of compounds recognized as carcinogenic, (2) the enhancing effect of (nitrosyl)heme on the formation of carcinogenic N-nitroso compounds and lipid peroxidation. However, none of these hypotheses completely explains the link between red and processed red meat intake and the CRC risk. Consequently, scientists have proposed additional mechanisms or refined their hypotheses. This review first briefly summarizes the development of CRC followed by an in-depth overview and critical discussion of the different potential carcinogenic mechanisms underlying the increased CRC risk associated with the consumption of red and processed red meat
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