Joint Hitting-Time Densities for Finite State Markov Processes

For a finite state Markov process and a finite collection $\{ \Gamma_k, k \in K \}$ of subsets of its state space, let $\tau_k$ be the first time the process visits the set $\Gamma_k$. We derive explicit/recursive formulas for the joint density and tail probabilities of the stopping times $\{ \tau_k, k \in K\}$. The formulas are natural generalizations of those associated with the jump times of a simple Poisson process. We give a numerical example and indicate the relevance of our results to credit risk modeling.Comment: 25 pages, 3 figure

Desirable Characteristics of Hepatitis C Treatment Regimens: A Review of What We Have and What We Need.

There have been dramatic advancements in the treatment of chronic hepatitis C (HCV) infection. This is largely due to the approval of several direct-acting antiviral agents (DAAs) from a variety of medication classes with novel mechanisms of action. These therapies are a welcomed advancement given their improved efficacy and tolerability compared to pegylated interferon and ribavirin (RBV)-based regimens. These convenient, all-oral regimens treat a variety of genotypes and often offer high cure rates in a variety of HCV-infected populations. While there are several benefits associated with these therapies, there are also notable shortcomings. Shortcomings include diminished response or need for adjunctive RBV in difficult-to-treat populations (decompensated cirrhosis, active substance abuse patients, advanced kidney disease, etc.), activity against select genotypes, substantial drug-drug interaction potential, and high cost. Therefore, while current DAA-based therapies have several favorable attributes, each also has its limitations. The purpose of this review is to (1) identify the characteristics of an ideal HCV treatment regimen, (2) describe desirable features of existing regimens, (3) summarize limitations of existing regimens, and (4) introduce promising emerging therapies. This manuscript will serve as a guide for evaluating the caliber of future HCV treatment regimens

Physically and Sexually Violent Juvenile Offenders: A Comparative Study of Victimization History Variables

The primary purpose of this study was to examine and compare physically and sexually violent juvenile offenders (PVJOs and SVJOs) to determine whether specific factors in their abuse histories, if present, tend to be associated with-the type of violent offense pattern they exhibit. The Youth Experiences and Behaviors Structured Interview (YEBSI)--an instrument which assesses for primary (victimization), secondary (witnessing), and perpetrated abuse of an emotional, physical, and sexual nature, by and/or toward family members, acquaintances, strangers, and animals--was developed by the primary researcher for use in this study. Thirty-six PVJOs and 30 SVJOs were interviewed. Results indicated that the YEBSI demonstrated high levels of internal consistency reliability and a very high level of interrater reliability. Various descriptive statistical, scale, and subscale correlations for the YEBSI were provided. Very high percentages of both groups reported experiencing and witnessing all types of abuse. In all cases, a similar or larger percentage of SVJOs reported histories of primary and secondary abuse. SVJOs reported more severe levels of emotional abuse, similar severity levels of physical abuse, and less extremely severe levels of sexual abuse than did PVJOs. Family members and acquaintances (as compared to strangers) tended to be far more frequently reported as perpetrators by respondents. Composite primary and secondary abuse scores were moderately correlated with abuse perpetration scores for SVJOs and strongly correlated with abuse perpetration scores for PVJOs. For emotional, family, acquaintance, and stranger abuse, reported primary-secondary abuse scores were found to be most highly correlated with abuse perpetration scores of the same nature (e.g., emotional abuse history-witness scores best correlated with physical abuse perpetration scores and family abuse history-witness scores best correlated with perpetration scores against family members) Finally, the classification variables correctly predicted 75% of those in the physically violent group and 67% of those in the sexually violent group, with an overall hit rate of 71%. Examination of the discriminant function-variable correlations in this study indicates that it was primarily the emotional, family-perpetrated, and sexual abuse subscales that defined the function. Theoretical interpretations and implications for these results are provided

Is There a Connection? An Exploratory Study of Abuse Experiences and Perpetration Patterns Among College Males

The purpose of this study was to examine self-reported experiences of primary, secondary, and perpetrated abuse of an emotional, physical, and sexual nature among a male, nonclinical, noncriminal sample. One hundred forty-two subjects completed the Youth Experiences and Behaviors Questionnaire (YEBQ) (developed by the author) and the Conflict Tactics Scale (CTS). Results indicated that overall, the YEBQ demonstrated moderate to high levels of internal consistency reliability and moderate levels of concurrent and divergent validity. Various descriptive statistics, scale, and subscale correlations for the YEBQ were provided. Results indicated that secondary abuse information was most predictive of later abuse perpetration with the exception of sexual abuse. Primary and secondary abuse information was found to be most predictive of abuse perpetration types of the same nature (e.g., emotional abuse history/witness scores best predicted emotional abuse perpetration scores and family abuse history/witness scores best predicted abuse perpetration toward family members scores) except in the cases of sexual abuse and stranger abuse. Theoretical interpretations and implications for these results are provided

The effect of the loss of Lgl1 in murine neural progenitor cells on MAPK signaling and proliferation

Glioblastoma is an incurable, aggressive, and highly invasive type of brain tumor that harbors tumor initiating cells characterized by disrupted polarized cell divisions. A cell polarity gene lethal (2) giant larvae 1 (Lgl1) has been implicated in gliomas and is a tumor suppressor initially identified in Drosophila with roles in proliferation. The loss of Lgl1 in Drosophila activates the MAPK protein kinase JNK and the Ras pathway and therefore its downstream kinase ERK, a transcription factor modulator. Furthermore, when Lgl1 is knocked out in mice, a phenotype similar to glioma is seen. Loss of the human form of Lgl1, Hugl1, and increases in c-Jun, an oncogene and JNK target, has been associated with glioma in humans. Additionally, the protooncogene transcription factor c-Myc is documented in glioma to directly correlate to tumor grade and an increase in an analogous form, d-Myc, in Drosophila has been shown to promote survival of Lgl mutants through a Ras mechanism. Here we sought to determine if the cancer properties associated with loss of Lgl in mice and humans are related to changes in MAPK signaling. To accomplish this, murine neural progenitor cells from the subventricular zone of mice with a Lgl1 knockout were cultured in vitro. These cells were plated adherently and characterized for changes in phosphorylation states of MAPK proteins ERK, JNK and p38 as well as two protooncogene MAPK downstream targets, c-Jun and c-Myc. In addition, to understand if MAPK phosphorylation is related to proliferation we characterized the proliferation rates of these cells in the presence of chemical inhibitors of p38 and ERK’s upstream activating kinase MEK. Differential expression patterns were observed in MAPK proteins and their downstream targets associated with the loss of Lgl1, under standard conditions and with the treatment of DMSO as a drug vehicle control and chemical inhibitors of p38 and MEK. Additionally, it was found that the loss of Lgl1 in neurosphere culture slightly increased growth and under adherent conditions this effect was not seen, however, changes did occur in the presence of p38 and MEK inhibitors. This supports previous data and signifies the importance of MAPK pathway in cancer phenotypes and beginning to characterize the role of the Lgl1 protein in the mouse

Perancangan Buku Cerita Anak Pop-Up “Mari Berkebun”

The research purpose is to gather, collect, and analyze data which needed in creating children story book in pop-up technique, with visually interesting gardening theme to interact with children. The research method is by direct survey into the location, such as schools, children story bookstores, and libraries. Besides, the research will be through literature media like books, magazines and journals; also supported by references contain related topic, like internet. The expected result is that education and added value message could be sent and understood by the children through the story books. The children would acknowledge, love, and preserve nature through gardening. In conclusion, nowadays, visual communication media like story books with interesting visual could gain children's interest. Therefore, by using pictured story book media in pop-up, it will facilitate the education process of introducing and preserving Mother Nature for children

Effects of manual and mechanical Ammophila arenaria removal techniques on coastal dune plant communities and dune morphology

The removal of invasive species as part of the restoration process can allow natives organisms to rebound. An ecosystem that incurs damages from invasive species is coastal sand dunes, which are dynamic systems. Some coastal sand dunes on the west coast of the United States have been invaded by Ammophila arenaria. The invasive grass, A. arenaria, is thought to alter and stabilize foredune morphology and reduce populations of native species. The objectives of my research are to examine the effects that manual and mechanical A. arenaria removal techniques have on coastal sand dune morphology and vegetative cover over time. The California State Parks Redwood District manages three coastal sand dune ecosystems where A. arenaria removal efforts have been conducted: Little River State Beach, Gold Bluffs Beach in Prairie Creek Redwoods State Park, and Tolowa Dunes State Park. I surveyed the vegetative cover at each of the three locations in each treatment method, manual and mechanical, and in untreated control plots during the summer and early fall of 2017. In order to measure dune morphology at restored and unrestored sites, I used an Unmanned Aerial Vehicle (UAV) that was flown over the mechanical removal and control areas. I then created a Digital Elevation Model (DEM) from photos taken during the UAV flights using Structure from Motion software. Overall, both mechanical and manual treatments lowered A. arenaria cover. Mechanical removal lowered the foredune elevation compared to control areas and changed the dune morphology in treatment areas into hummocks at Little River. Although mechanical removal was effective at lowering A. arenaria cover, it also lowered native plant diversity compared to manual removal, but was higher than control diversity. With endemic species of concern on coastal sand dunes, manual removal of A. arenaria will afford greater native plant diversity and cover compared to mechanical removal