Discount Rates for Nonindustrial Private Forest Landowners in Mississippi: How High a Hurdle?

Mississippi forest landowners were surveyed to determine average discount rates or “hurdle rates”—the lowest rates of return they consider acceptable—for 3 nonforestry investments, and for 5, 15, and 25 yr forestry investments. The survey included 829 individuals who owned at least 20 ac of uncultivated land and had harvested timber during a recent 5 yr period; survey results are therefore oriented toward commercially active forest landowners. On average, the private nonindustrial forest landowners included in the survey expect timberland investments to earn higher rates of compound interest than relatively low-risk bank savings accounts and certificates of deposit. Relatively short-term (5 yr) timberland investments, however, have lower minimum rates of return than stocks, bonds, and mutual funds. With forestry investments, all else equal, Mississippi nonindustrial private forest landowners prefer shorter time periods—average hurdle rates in nominal terms before taxes were 8.0% for forestry investments lasting 5 yr, 11.3% for those lasting 15 yr, and 13.1% for those lasting 25 yr. Household income significantly influenced the lowest rate of return considered acceptable for 5 yr forestry investments—the rate was 9% for landowners with annual incomes above $50,000 and 7.4$50,000. On a hurdle rate basis, higher income private landowners in Mississippi generally find forestry investments lasting 15 yr to be competitive with stocks, bonds, and mutual funds. However, Mississippi landowners’ 13.1% required rate of return for 25 yr forestry investments was higher than the rate considered acceptable for the other investments included in the survey. Reforestation tax incentives, cost-shares, and related public policies that reduce the front-end costs incurred by NIPF landowners tend to increase the projected rate of return for relatively long-term reforestation investments. South. J. Appl. For. 26(1):26–31

Reforestation of harvested Timberlands in Mississippi: Behavior and Attitudes of Non-Industrial, Private Forest Landowners

Southern forests play an increasingly important role in the timber economy as per capita demand for wood continues to expand. Moreover, harvest restrictions in the Pacific Northwest in the early 1990s shifted a large portion of United States demand for softwoods to the South. In Mississippi, most of the forestland is owned by non-industrial private forest (NIPF) landowners. Approximately 314,000 NIPF landowners control 66 percent of the state’s forestland base (Hartsell and London 1995). The sizable acreage of timberland held by NIPF landowners nationally and in-state underscores the importance of their role in the timber economy and weighs heavily in the supply of raw material to the state’s $11.4 billion forest products industry (Munn 1998)

Comparison Between Regenerators and Non-Regenerators in Mississippi: A Discriminant Analysis

Nonindustrial private forestland (NIPF) landowners in Mississippi who recently harvested timber were surveyed to examine their regeneration behavior. Differences between regenerators and nonregenerators were investigated by looking at the different factors affecting reforestation decisions. A discriminant analysis was used to identify factors that were useful in differentiating between regenerators and nonregenerators. Ownership size; sociodemographic characteristics such as income, education, place of residence, and age; awareness of existing government incentive/assistance programs; and participation in educational programs were significant variables in differentiating between regenerators and nonregenerators. Landowners who own larger timberlands had a higher propensity to engage in regeneration activities after harvests. This also was true for landowners who had higher income levels and educational attainment, and were younger, city resident, and white. Landowners who were aware of existing government incentive/assistance programs and those who participated in educational programs also were more likely to participate in pine regeneration. Landowners in Mississippi considered both ecological and economic reasons as highly important considerations in their decision to regenerate. The belief that the land would reforest itself to pine naturally, the high cost of reforestation, and lack of information on reforestation options were top reasons cited by landowners for their decision not to regenerate. South. J. Appl. For. 28(4):189 –19

Factors Affecting Mississippi’s NIPF Landowners’ Reforestation Decisions

Non-industrial private forest (NIPF) landowners have played an increasingly important role in the nation\u27s timber economy. Nearly 70% of the forestland in the South is owned by NIPF landowners (Powell et al., 1994). In Mississippi alone, these landowners control approximately 66% of the state\u27s forestland base (Hartsell and London, 1995). Therefore, NIPF landowners are expected to provide a large portion of the state\u27s supply of timber. However, whether they do so depends largely on how their timberlands are managed. Forest management decisions of NIPF landowners can impact future timber supply due to the magnitude of their collective ownership

The transcription factor Hey and nuclear lamins specify and maintain cell identity

The inability of differentiated cells to maintain their identity is a hallmark of age-related diseases. We found that the transcription factor Hey supervises the identity of differentiated enterocytes (ECs) in the adult Drosophila midgut. Lineage tracing established that Hey-deficient ECs are unable to maintain their unique nuclear organization and identity. To supervise cell identity, Hey determines the expression of nuclear lamins, switching from a stem-cell lamin configuration to a differentiated lamin configuration. Moreover, continued Hey expression is required to conserve large-scale nuclear organization. During aging, Hey levels decline, and EC identity and gut homeostasis are impaired, including pathological reprograming and compromised gut integrity. These phenotypes are highly similar to those observed upon acute targeting of Hey or perturbation of lamin expression in ECs in young adults. Indeed, aging phenotypes were suppressed by continued expression of Hey in ECs, suggesting that a Hey-lamin network safeguards nuclear organization and differentiated cell identity

A novel immunoscintigraphy technique using metabolizable linker with angiotensin II treatment

Immunoscintigraphy is a tumour imaging technique that can have specificity, but high background radioactivity makes it difficult to obtain tumour imaging soon after the injection of radioconjugate. The aim of this study is to see whether clear tumour images can be obtained soon after injection of a radiolabelled reagent using a new linker with antibody fragments (Fab), in conditions of induced hypertension in mice. Fab fragments of a murine monoclonal antibody against human osteosarcoma were labelled with radioiodinated 3′-iodohippuryl N-ɛ-maleoyl-L-lysine (HML) and were injected intravenously to tumour-bearing mice. Angiotensin II was administered for 4 h before and for 1 h after the injection of radiolabelled Fab. Kidney uptake of 125I-labelled-HML-Fab was much lower than that of 125I-labelled-Fab radioiodinated by the chloramine-T method, and the radioactivity of tumour was increased approximately two-fold by angiotensin II treatment at 3 h after injection, indicating high tumour-to-normal tissue ratios. A clear tumour image was obtained with 131I-labelled-HML-Fab at 3 h post-injection. The use of HML as a radiolabelling reagent, combined with angiotensin II treatment, efficiently improved tumour targeting and enabled the imaging of tumours. These results suggest the feasibility of PET scan using antibody fragment labelled with 18F-fluorine substitute for radioiodine. © 1999 Cancer Research Campaig

Molecular basis for chromatin binding and regulation of MLL5

The human mixed-lineage leukemia 5 (MLL5) protein mediates hematopoietic cell homeostasis, cell cycle, and survival; however, the molecular basis underlying MLL5 activities remains unknown. Here, we show that MLL5 is recruited to gene-rich euchromatic regions via the interaction of its plant homeodomain finger with the histone mark H3K4me3. The 1.48-Å resolution crystal structure of MLL5 plant homeodomain in complex with the H3K4me3 peptide reveals a noncanonical binding mechanism, whereby K4me3 is recognized through a single aromatic residue and an aspartate. The binding induces a unique His–Asp swapping rearrangement mediated by a C-terminal α-helix. Phosphorylation of H3T3 and H3T6 abrogates the association with H3K4me3 in vitro and in vivo, releasing MLL5 from chromatin in mitosis. This regulatory switch is conserved in the Drosophila ortholog of MLL5, UpSET, and suggests the developmental control for targeting of H3K4me3. Together, our findings provide first insights into the molecular basis for the recruitment, exclusion, and regulation of MLL5 at chromatin

Practical application of cure mixture model for long-term censored survivor data from a withdrawal clinical trial of patients with major depressive disorder

<p>Abstract</p> <p>Background</p> <p>Survival analysis methods such as the Kaplan-Meier method, log-rank test, and Cox proportional hazards regression (Cox regression) are commonly used to analyze data from randomized withdrawal studies in patients with major depressive disorder. However, unfortunately, such common methods may be inappropriate when a long-term censored relapse-free time appears in data as the methods assume that if complete follow-up were possible for all individuals, each would eventually experience the event of interest.</p> <p>Methods</p> <p>In this paper, to analyse data including such a long-term censored relapse-free time, we discuss a semi-parametric cure regression (Cox cure regression), which combines a logistic formulation for the probability of occurrence of an event with a Cox proportional hazards specification for the time of occurrence of the event. In specifying the treatment's effect on disease-free survival, we consider the fraction of long-term survivors and the risks associated with a relapse of the disease. In addition, we develop a tree-based method for the time to event data to identify groups of patients with differing prognoses (cure survival CART). Although analysis methods typically adapt the log-rank statistic for recursive partitioning procedures, the method applied here used a likelihood ratio (LR) test statistic from a fitting of cure survival regression assuming exponential and Weibull distributions for the latency time of relapse.</p> <p>Results</p> <p>The method is illustrated using data from a sertraline randomized withdrawal study in patients with major depressive disorder.</p> <p>Conclusions</p> <p>We concluded that Cox cure regression reveals facts on who may be cured, and how the treatment and other factors effect on the cured incidence and on the relapse time of uncured patients, and that cure survival CART output provides easily understandable and interpretable information, useful both in identifying groups of patients with differing prognoses and in utilizing Cox cure regression models leading to meaningful interpretations.</p

Mutations in PIK3CA are infrequent in neuroblastoma

BACKGROUND: Neuroblastoma is a frequently lethal pediatric cancer in which MYCN genomic amplification is highly correlated with aggressive disease. Deregulated MYC genes require co-operative lesions to foster tumourigenesis and both direct and indirect evidence support activated Ras signaling for this purpose in many cancers. Yet Ras genes and Braf, while often activated in cancer cells, are infrequent targets for activation in neuroblastoma. Recently, the Ras effector PIK3CA was shown to be activated in diverse human cancers. We therefore assessed PIK3CA for mutation in human neuroblastomas, as well as in neuroblastomas arising in transgenic mice with MYCN overexpressed in neural-crest tissues. In this murine model we additionally surveyed for Ras family and Braf mutations as these have not been previously reported. METHODS: Sixty-nine human neuroblastomas (42 primary tumors and 27 cell lines) were sequenced for PIK3CA activating mutations within the C2, helical and kinase domain "hot spots" where 80% of mutations cluster. Constitutional DNA was sequenced in cases with confirmed alterations to assess for germline or somatic acquisition. Additionally, Ras family members (Hras1, Kras2 and Nras) and the downstream effectors Pik3ca and Braf, were sequenced from twenty-five neuroblastomas arising in neuroblastoma-prone transgenic mice. RESULTS: We identified mutations in the PIK3CA gene in 2 of 69 human neuroblastomas (2.9%). Neither mutation (R524M and E982D) has been studied to date for effects on lipid kinase activity. Though both occurred in tumors with MYCN amplification the overall rate of PIK3CA mutations in MYCN amplified and single-copy tumors did not differ appreciably (2 of 31 versus 0 of 38, respectively). Further, no activating mutations were identified in a survey of Ras signal transduction genes (including Hras1, Kras2, Nras, Pik3ca, or Braf genes) in twenty-five neuroblastic tumors arising in the MYCN-initiated transgenic mouse model. CONCLUSION: These data suggest that activating mutations in the Ras/Raf-MAPK/PI3K signaling cascades occur infrequently in neuroblastoma. Further, despite compelling evidence for MYC and RAS cooperation in vitro and in vivo to promote tumourigenesis, activation of RAS signal transduction does not constitute a preferred secondary pathway in neuroblastomas with MYCN deregulation in either human tumors or murine models