764 research outputs found
Estimates of quantitave genetic parameters in IAP2B random-mating sorghum population
Seed composition from S[subscript]1 families of C0, C2, C3, C4, and half-sib families of C1, C2, C3, and C4, together with 60 individual S[subscript]1 families chosen randomly from C0 and C4 of sorghum (Sorghum bicolor (L.) Moench) population IAP2B were evaluated in five Iowa environments;Four cycles of gridded mass selection of individual-panicle grain weight shifted the mean for grain yield favorably, and the range among S[subscript]1 families was extended. Increased values in C4 also were observed for seeds/panicle, 100-seed weight, days to midbloom, and plant height, but panicles/plant decreased. Genotypic variance among S[subscript]1 families increased from C0 to C4 for grain yield and days to midbloom. Estimates of inbreeding depression were significant (p \u3c 0.05 or 0.01) for grain yield (-18.2%), panicles/plant (-13.7%), plant height (-11.5%), and 100-seed weight (-8.4%). Appreciable nonadditive gene action was expressed for those traits. Seeds/panicle and days to midbloom displayed additive gene action;Heritability estimates for grain yield increased from C0 to C4, but they decreased for panicles/plant. Expected gain/year for grain yield by using S[subscript]1 family selection increased from C0 (2.0% of the mean) to C4 (3.2%). Estimates for C0 vs C4 showed a decrease for panicles/plant (from 4.5% to 3.6% of the mean);Correlation coefficients indicated that selection for individual-panicle grain weight also influenced other characters. Correlations changed substantially in a positive direction from C0 to C4 for grain yield vs seeds/panicle, grain yield vs panicles/plant, and seeds/panicle vs panicles/plant, but they changed in a negative manner for grain yield vs 100-seed weight;Parameters estimated for the S[subscript]1 families and cycle composites indicated that IAP2B(M) should prove useful for developing female parents with a wide array of gene combinations. The higher estimates of genotypic variance and heritability for grain yield in C4, as well as the larger estimates of expected gain from S[subscript]1 family selection, indicated that further improvement of the population should be expected with additional cycles of recurrent selection
Supercalender Variables (I) The Effect of Supercalender Pressure on the Physical Characteristics of Paper
This work is concerned with the effect of supercalender pressures on the physical properties of paper.
The literature survey shows that very little work has been published concerning the effect of the variables of supercalendering on paper. In this investigation, a study is made of the effect of varied supercalendering pressures on 50 percent rag ledger and coated folder paper. The experimental results show that definite trends were established on physical strength and optical properties when supercalender pressure w as increased
Dynamic and sequential patterning of the zebrafish posterior hindbrain by retinoic acid
AbstractA prominent region of the vertebrate hindbrain is subdivided along the anterior–posterior axis into a series of seven segments, or rhombomeres. The identity of each rhombomere is specified by the expression of conserved transcription factors, including Krox-20, vHnf1, Val (Kreisler, Mafb) and several Hox proteins. Previous work has shown that retinoic acid (RA) signaling plays a critical role in regulating the expression of these factors and that more posterior rhombomeres require higher levels of RA than more anterior rhombomeres. Models to account for RA concentration dependency have proposed either a static RA gradient or increasing time periods of RA exposure. Here, we provide evidence against both of these models. We show that early zebrafish rhombomere-specification genes, including vhnf1 in r5–r6 and hoxd4a in r7, initiate expression sequentially in the hindbrain, each adjacent to the source of RA synthesis in paraxial mesoderm. By knocking down RA signaling, we show that progressively more posterior rhombomeres require increasingly higher levels of RA signaling, and vhnf1 and hoxd4a expression are particularly RA-dependent. RA synthesis is required just at the time of initiation, but not for maintenance, of vhnf1 and hoxd4a expression. Furthermore, a premature RA increase causes premature activation of vhnf1 and hoxd4a expression. Our results support a new model of dynamic RA action in the hindbrain, in which a temporally increasing source of RA is required to sequentially initiate progressively more posterior rhombomere identities
Military purges and the recurrence of civil conflict
Literature on coup-proofing often suggests that such activities reduce military effectiveness, which could provide an environment ripe for civil conflict. However, if coupproofing is so dangerous, why do we observe leaders engaging in these strategies? We argue that a specific type of coup-proofing–purges–deters domestic unrest by demonstrating the strength of the regime via the removal of powerful but undesirable individuals from office. The strategic and intentional nature of purges signals to opposition forces that the regime is capable of not only identifying its enemies but also eliminating these threats. Furthermore, the removal of high-profile officers often leads to their elimination from forums in which they could join existing rebel groups or mount new resistance to the regime, additionally decreasing the risk of renewed fighting. We use original data on military purges in non-democracies from 1969-2003 to assess quantitatively how this type of coup-proofing activity affects the likelihood of civil conflict recurrence. We find support for our expectation that military purges of high-ranking officials do in fact help the regime to avoid further civil conflict. Purges appear to provide real benefits to dictators seeking to preserve stability, at least in post-conflict environments
Agronomic Performance of Sorghum Hybrids Produced by using Different Male-sterility-inducing Cytoplasms
Experiments were conducted in three environments in Iowa to obtain information on the effects of different cytoplasms on agronomic characters in grain sorghum (Sorghum bicolor L. Moench) hybrids. Compared with A1 cytoplasm, A2 and A3 cytoplasms delayed flowering; reduced the percentage of fertile pollen, the number of seeds per panicle, and grain yield; and increased 100-seed weight of the hybrids. Hybrids with A2 or A3 cytoplasm did not differ (p ≥0.05) from those in the A1 cytoplasm for plant height, panicles per plant, or for length, width, and area of the third and fourth leaves from the top of the plant. A2-cytoplasm hybrids did not differ (p ≥0.05) from those in A3 cytoplasm for any of the traits measure. The results are discussed relative to the performance of hybrids with pollen fertility restored and not restored
Trauma-Informed Risk Assessment in Correctional Settings
This paper outlines a model which infuses trauma-informed principles into the existing Risk-Needs-Responsivity model of risk assessment commonly used in correctional settings. The connection between certain types of trauma and criminality is established. Despite this, many risk assessment procedures do not include screening for trauma, or trauma-specific interventions. An overview of the lasting effects of childhood maltreatment is included. Trauma-informed practices and assessment recommendations are also provided, along with recommendations for additional resources
The Costs of Domestic Political Unrest
Does domestic political unrest deter foreign direct investment (FDI)? And what are the longer term impacts of unrest upon the market? Most theories suggest that investors are deterred by unrest. However, empirical research returns only marginal support. We argue that these mixed results stem from the conflation of the distinct tactics and outcomes of political unrest. Violent forms of unrest increase uncertainty and risk. By comparison, nonviolent forms of unrest are shown to more frequently achieve their goals and increase the prospects for democratic change and market stability. In addition, investors avoid markets where campaigns have ended in failure, defined as the campaign not achieving their stated political aims. Failed campaigns often precipitate a cycle of unrest that create greater uncertainty over the long-term stability of a state. We find strong evidence in favor of our propositions, even after taking political motivation and non-random selection into account. © 2013 International Studies Association
Interdistrict Choice Beyond the Classroom: Transfer Student Challenges in Selecting and Attending Suburban Schools of Choice
2021 Pamela J. Mackintosh Undergraduate Research Awards, Multi-term, 2nd PlaceInterdistrict transfer is the largest form of school choice in the United States, yet little is understood about how students experience these programs on an individual level. This thesis uses two sets of semi-structured interviews of recent Michigan high school graduates to investigate how families make decisions about school choice in a regional context and subsequently what challenges central city transfer students face in suburban educational environments. The first subject group consists of former students from a central city community who transferred to suburban public schools through Michigan’s interdistrict Schools of Choice program. The second group consists of former students who remained in the central city district throughhigh school. Based on my results, I argue that we must add complexity to our understanding of interdistrict choice in three specific ways. First, we must acknowledge and analyze the dynamic agency that students share with parents in making decisions about where to attend school. Second, central city transfer students in suburban interdistrict choice programs encounter significant social and emotional challenges as a result of their transfer. Finally, where the needs of transfer students diverge from the needs of residential students on the basis of racial, socioeconomic, and geographic differences, I find that transfer students receive inadequate institutional support from their chosen suburban schools.http://deepblue.lib.umich.edu/bitstream/2027.42/168406/1/Maves_Thesis.pdff4ff7577-2bc3-41bf-b9b3-048dca20629fDescription of Maves_Thesis.pdf : Honors ThesisSEL
The European Union as a military actor
Since 1999, the European Union has strived to develop a more holistic foreign policy apparatus. The EU has always prided itself on its effective use of `soft power' means of achieving foreign policy goals; but strife in the Balkans made clear the need for `hard power' options as well. This paper examines the development of the EU's ability to conduct military operations in crisis situations. It looks at the foreign policy goals set forth in the 2003 European Security Strategy and what steps the EU has taken to attain them from a military standpoint. The potential benefits of the Permanent Structured Cooperation clause in the Treaty of Lisbon are addressed. As are the limitations placed on any potential CSDP military operation due to the lack of a unified command and control infrastructure in the EU
- …