2,309 research outputs found
Using APT to Assess the Impact of Farm Policy on Agribusiness Stocks
This study investigates the impact of differing U. S. Farm Policy regimes on the stock prices of publicly traded agribusinesses. Following the Roll and Ross approach, we apply a two step Arbitrage Pricing Model (APM). We analyze the effect of agricultural policy on returns to agribusiness by applying a modified APM to agricultural returns to test for the presence of an agribusiness premium or discount. We further augment our analysis by dividing the sample into two time periods around the implementation of the 1996. The differences in agribusiness premium can then be tested using a paired t-test. The empirical evidence lends support to a switch from negative returns to agribusiness stocks pre-FAIR Act to positive returns to agribusiness stocks after its enactment.Agribusiness, Agricultural and Food Policy,
Using Land Values to Predict Future Farm Income
land values, almon lag, farm profitability, Agribusiness, Agricultural Finance, Farm Management, Financial Economics, Production Economics,
Assessing the Rationality of Farmland Price Movements
Replaced with revised version of poster 06/03/11.Agricultural Finance, Farm Management,
The risks may be too high
The proposed revisions to the diagnosis of personality disorders in ICD‐11 move the diagnosis of personality disorders from the categorical to the dimensional. Although there may be a number of good reasons to consider changes in the manner in which we diagnose personality disorders, the method proposed here goes too far in the degree of changes that it proposes. It ignores the fact that at least for some of the personality disorders, there is data that supports them as distinct diagnostic entities separate from other axis I and axis II disorders. Eliminating the diagnostic categories that have been part of the established psychiatric nomenclature for the last 30 years threatens to undermine the significant research and clinical advances that have been made using categorical diagnoses. Copyright © 2011 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87112/1/pmh187.pd
RANDOM GEOMETRIC GRAPHS AND ISOMETRIES OF NORMED SPACES
Given a countable dense subset S of a finite-dimensional normed space X, and 0 \u3c p \u3c 1, we form a random graph on S by joining, independently and with probability p, each pair of points at distance less than 1. We say that S is Rado if any two such random graphs are (almost surely) isomorphic. Bonato and Janssen showed that in ℓd∞ almost all S are Rado. Our main aim in this paper is to show that ℓd∞ is the unique normed space with this property: indeed, in every other space almost all sets S are non-Rado. We also determine which spaces admit some Rado set: this turns out to be the spaces that have an ℓ∞ direct summand. These results answer questions of Bonato and Janssen. A key role is played by the determination of which finite-dimensional normed spaces have the property that every bijective step-isometry (meaning that the integer part of distances is preserved) is in fact an isometry. This result may be of independent interest
Differentiated State of Initiating Tumor Cells Is Key to Distinctive Immune Responses Seen in H-Ras
Heterogeneity in tumor immune responses is a poorly understood yet critical parameter for successful immunotherapy. In two doxycycline-inducible models where oncogenic H-RasG12V is targeted either to the epidermal basal/stem cell layer with a Keratin14-rtTA transgene (K14Ras), or committed progenitor/suprabasal cells with an Involucrin-tTA transgene (InvRas), we observed strikingly distinct tumor immune responses. On threshold doxycycline levels yielding similar Ras expression, tumor latency, and numbers, tumors from K14Ras mice had an immunosuppressed microenvironment, whereas InvRas tumors had a proinflammatory microenvironment. On a Rag1-/- background, InvRas mice developed fewer and smaller tumors that regressed over time, whereas K14Ras mice developed more tumors with shorter latency than Rag1+/+ controls. Adoptive transfer and depletion studies revealed that B-cell and CD4 T-cell cooperation was critical for tumor yield, lymphocyte polarization, and tumor immune phenotype in Rag1+/+ mice of both models. Coculture of tumor-conditioned B cells with CD4 T cells implicated direct contact for Th1 and regulatory T cell (Treg) polarization, and CD40-CD40L for Th1, Th2, and Treg generation, a response not observed from splenic B cells. Anti-CD40L caused regression of InvRas tumors but enhanced growth in K14Ras, whereas a CD40 agonist mAb had opposite effects in each tumor model. These data show that position of tumor-initiating cells within a stratified squamous epithelial tissue provokes distinct B- and CD4 T-cell interactions, which establish unique tumor microenvironments that regulate tumor development and response to immunotherap
TGFβ1 Overexpression by Keratinocytes Alters Skin Dendritic Cell Homeostasis and Enhances Contact Hypersensitivity
Overexpression of transforming growth factor beta-1 (TGFβ1) in mouse epidermis causes cutaneous inflammation and keratinocyte hyperproliferation. Here we examined acute effects of TGFβ1 overproduction by keratinocytes on skin dendritic cells (DCs). TGFβ1 induction for 2 and 4 days increased the numbers and CD86 expression of B220+ plasmacytoid DCs (pDCs) and CD207+CD103+, CD207−CD103−CD11b+, and CD207−CD103−CD11b− dermal DCs (dDCs) in skin-draining lymph nodes (SDLNs). The dermis of TGFβ1-overexpressing mice had significantly more pDCs, CD207+CD103+ dDCs, and CD207−CD11b+ dDCs in the absence of increased dermal proliferation. Application of dye, tetramethyl rhodamine iso-thiocyanate (TRITC), in dibutylpthalate (DBP) solution after TGFβ1 induction increased the numbers of TRITC+CD207− dDCs in SDLNs, and augmented TRITC/DBP-induced Langerhans cell (LC) migration 72hours post TRITC treatment. Consistent with this, LC migration was increased in vitro by TGFβ1 overexpression in skin explants and by exogenous TGFβ1 in culture media. Transient TGFβ1 induction during DNFB sensitization increased contact hypersensitivity responses by 1.5-fold. Thus, elevated epidermal TGFβ1 alone is sufficient to alter homeostasis of multiple cutaneous DC subsets, and enhance DC migration and immune responses to contact sensitizers. These results highlight a role for keratinocyte-derived TGFβ1 in DC trafficking and in the initiation of skin inflammation
Reduction of human chorionic gonadotropin beta subunit expression by modified U1 snRNA caused apoptosis in cervical cancer cells
BACKGROUND:
Secretion of human chorionic gonadotropin, especially its beta subunit by malignant trophoblastic tumors and varieties of tumors of different origin is now well documented; however the role of hCG in tumorogenesis is still unknown.
RESULTS:
This study documents the molecular presence of human chorionic gonadotropin beta subunit in uterine cervix cancer tissues and investigates a novel technique to reduce hCGbeta levels based on expression of a modified U1 snRNA as a method to study the hormone's role in biology of human cervical cancer cells cultured in vitro. The property of U1 snRNA to block the accumulation of specific RNA transcript when it binds to its donor sequence within the 3' terminal exon was used. The first 10 nucleotides of the human U1 snRNA gene, which normally binds to the 5'ss in pre-mRNA were replaced by a sequence complementary to a 10-nt segment in the terminal exon of the hCGbeta mRNA. Three different 5' end-mutated U1 snRNA expression plasmids were tested, each targeting a different sequence in the hCGbeta mRNA, and we found each one blocked the expression of hCGbeta in HeLa cells, a cervix carcinoma cell line, as shown by immunohistochemistry and qRT-PCR. Reduction of hCGbeta levels resulted in a significantly increased apoptosis rate with almost 90% of cells transfected with modified anti-hCGbeta U1 snRNAs showing morphological changes characteristic of the apoptotic process.
CONCLUSION:
These data suggest that human chorionic gonadotropin beta subunit may act as a tumor growth-stimulating factor
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