Congressional Representation of Black Interests: Recognizing the Importance of Stability

The relationship between black constituency size and congressional support for black interests has two important attributes: magnitude and stability. Although previous research has examined the first characteristic, scant attention has been directed at the second. This article examines the relationship between district racial composition and congressional voting patterns with a particular emphasis on the stability of support across different types of votes and different types of districts. We hypothesize that, among white Democrats, the influence of black constituency size will be less stable in the South, owing in part to this region’s more racially divided constituencies. Examining LCCR scores from the 101st through 103rd Congress, we find that this expectation is largely confirmed. We also find that, among Republicans, the impact of black constituency size is most stable—albeit negligible in size— in the South. We conclude by discussing the implications of these findings for the relative merits of “influence districts” and “majority minority” districts

Policy Risk and Private Investment in Ontario’s Wind Power Sector

Even though governments may adopt favourable regulatory policies for renewable power generation, their ability to encourage private sector investment depends also on the presence of regulatory governance institutions that provide credible long-term commitments to potential investors. In the case of Ontario we contend that, despite large market potential and comparatively strong regulatory incentive policies, weak regulatory governance is one factor that has accounted for the challenges in attracting and implementing large scale private investment in power generation at a reasonable cost. We find empirical support for our arguments in a unique survey of 63 wind power firms that assessed private sector opinions about the investment environment for renewable energy in Ontario. Compared to a range of factors, firms rated the stability of regulatory policy among the weakest aspects of Ontario?s business environment. However, policy stability ranked among the most important factors in firms? assessments of the attractiveness of alternative jurisdictions in their location decisions. Subsequent interviews revealed that firms have responded to this risk in Ontario by explicitly pricing it into wind project financial models – implying higher wind power prices for ratepayers – and by directing investment funds to other jurisdictions. We argue that policy stability in Ontario may be improved by devolving greater decision-making authority to regulatory agencies in the energy sector and by strengthening their institutional independence.

Symptomless banana suckers sourced from Xanthomonas wilt infected fields are a viable alternative for seed within infected banana-based landscapes lacking access to clean planting materials

Xanthomonas wilt (XW) caused by Xanthomonas campestris pv. musacearum (Xcm) is an important constraint to banana production in East and Central Africa. The use of clean planting materials (CPM) for establishing new fields/ re-planting rouged fields/mats is recommended. However, banana is mainly produced by resource-poor small-holder households with no/limited access to CPM. We assessed XW incidence in fields planted with symptomless suckers sourced from fields with >70% XW incidence and the role of Xcm-soil inoculum on XW persistence in North Kivu Province, eastern DR Congo. Symptomless suckers were planted in i) fields previously with banana having >70% XW incidence, 10 days after rouging and ii) fields previously under grass fallow. Symptomless suckers planted in fields previously under grass fallow served as checks. To contrast, healthy suckers and healthy macro-propagated plantlets were established in similar field typologies. Each treatment combination had three replicates of 30 plants. Additional experiments established in September, 2014 in South Kivu Province using symptomless suckers from fields with incidence levels varying from 1 to 90% assessed the reproducibility of the North Kivu results. In the North Kivu trials and when using symptomless suckers, relatively low cumulative XW plant incidences of 3.6 and 4.2% were recorded in fields previously under grass fallow and fields with >70% initial XW-incidence, respectively. The resulting fields were well established, suggesting that suckers sourced from diseased fields could potentially be used in zones with no access to CPM. Even lower incidences (0 to 0.28%) recorded in South Kivu further support this. Plant incidences of 1.8 and 2.9% were respectively observed in previously diseased fields planted with healthy macro-propagated plantlets and healthy suckers compared with zero incidence levels in the disease-free fields, confirming the role of residual Xcm-soil inoculum in infections

AMORD: A Deductive Procedure System

This research was conducted at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the Laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under Office of Naval Research contract number N00014-75-C-0643.We have implemented an interpreter for a rule-based system, AMORD, based on a non-chronological control structure and a system of automatically maintained data-dependencies. The purpose of this paper is tutorial. We wish to illustrate: (1) The discipline of explicit control and dependencies, (2) How to use AMORD, and (3) One way to implement the mechanisms provided by AMORD. This paper is organized into sections. The first section is a short "reference manual" describing the major features of AMORD. Next, we present some examples which illustrate the style of expression encouraged by AMORD. This style makes control information explicit in a rule-manipulable form, and depends on an understanding of the use of non-chronological justifications for program beliefs as a means for determining the current set of beliefs. The third section is a brief description of the Truth Maintenance System employed by AMORD for maintaining these justifications and program beliefs. The fourth section presents a completely annotated interpreter for AMORD, written in SCHEME.MIT Artificial Intelligence Laboratory Department of Defense Advanced Research Projects Agenc

Overexpression of the CBF2 transcriptional activator in Arabidopsis delays leaf senescence and extends plant longevity

Leaf senescence is a programmed developmental process governed by various endogenous and exogenous factors, such as the plant developmental stage, leaf age, phytohormone levels, darkness, and exposure to stresses. It was found that, in addition to its well-documented role in the enhancement of plant frost tolerance, overexpression of the C-repeat/dehydration responsive element binding factor 2 (CBF2) gene in Arabidopsis delayed the onset of leaf senescence and extended the life span of the plants by approximately 2 weeks. This phenomenon was exhibited both during developmental leaf senescence and during senescence of detached leaves artificially induced by either darkness or phytohormones. Transcriptome analysis using the Affymetrix ATH1 genome array revealed that overexpression of CBF2 significantly influenced the expression of 286 genes in mature leaf tissue. In addition to 30 stress-related genes, overexpression of CBF2 also affected the expression of 24 transcription factor (TF) genes, and 20 genes involved in protein metabolism, degradation, and post-translational modification. These results indicate that overexpression of CBF2 not only increases frost tolerance, but also affects other developmental processes, most likely through interactions with additional TFs and protein modification genes. The present findings shed new light on the crucial relationship between plant stress tolerance and longevity, as reported for other eukaryotic organisms

Agronomic performance of local and introduced plantains, dessert, cooking and beer bananas (Musa spp.) across different altitude and soil conditions in eastern Democratic Republic of Congo

Open access Journal; Published: 27 October 2016Agronomic performances of local and exotic Musa species were evaluated across seven agro-ecologies in Eastern Democratic Republic of Congo. Generally, all the cultivars performed well. Mean bunch yields varied between 11 and 42 kg across different use groups and agro-ecologies. Introduced cultivars had higher or comparable yields to the local cultivars across agro-ecologies. The exotic beer cultivar ‘NARIAT 27’ generally outperformed other beer types. The green cooking exotic types ‘NARITA 4’ and ‘NARITA 2’ produced bunches of up to 37 and 39 kg, respectively at altitudes of 1066 and 1111 m, though having smaller bunches of 21 to 25 kg, at 900 and 1707 m in comparison to the local type ‘Barhabeshya’ (30 to 37 kg). Yields were mainly influenced by soil factors and altitude. Yields generally increased with increase in OM, N, P, K, Ca, and pH. Altitude had a non-linear relationship with the time from planting to flowering, with the time from planting to flowering declining at higher altitudes. In contrast, the fruit filling phase increased linearly with altitude. Bunch weights of most cultivars declined with increasing altitude; particularly, when N, K, P and OM concentrations were low; possibly because most assimilates go towards sucker development at the high altitudes. For example, bunch weights of ‘Barhabeshya’, ‘Mbwazirume’ and ‘Nshika’ strongly declined (R2 = -0.56-0.99) with increasing altitude. ‘Ndundu’, ‘FHIA21’ and ‘Gros Michel’ thrived well at high altitude sites. Such variations in cultivar adaptability plus cultivar attributes, e.g. height can be exploited by selectively promoting cultivars in specific agro-ecologies/niches

Report of the 1988 2-D Intercomparison Workshop, chapter 3

Several factors contribute to the errors encountered. With the exception of the line-by-line model, all of the models employ simplifying assumptions that place fundamental limits on their accuracy and range of validity. For example, all 2-D modeling groups use the diffusivity factor approximation. This approximation produces little error in tropospheric H2O and CO2 cooling rates, but can produce significant errors in CO2 and O3 cooling rates at the stratopause. All models suffer from fundamental uncertainties in shapes and strengths of spectral lines. Thermal flux algorithms being used in 2-D tracer tranport models produce cooling rates that differ by as much as 40 percent for the same input model atmosphere. Disagreements of this magnitude are important since the thermal cooling rates must be subtracted from the almost-equal solar heating rates to derive the net radiative heating rates and the 2-D model diabatic circulation. For much of the annual cycle, the net radiative heating rates are comparable in magnitude to the cooling rate differences described. Many of the models underestimate the cooling rates in the middle and lower stratosphere. The consequences of these errors for the net heating rates and the diabatic circulation will depend on their meridional structure, which was not tested here. Other models underestimate the cooling near 1 mbar. Suchs errors pose potential problems for future interactive ozone assessment studies, since they could produce artificially-high temperatures and increased O3 destruction at these levels. These concerns suggest that a great deal of work is needed to improve the performance of thermal cooling rate algorithms used in the 2-D tracer transport models

Household uses of the banana plant in eastern Democratic Republic of Congo

Banana is ranked first among staple crops in the eastern Democratic Republic of Congo (DR Congo). Depending on the agro-ecological conditions, cultivars grown, cultural and socio-economic factors, the use of other banana plant parts other than the fruit, has been widely reported. This has not been documented in this region. This study examined the other household uses of banana in North and South Kivu provinces, eastern DR Congo. Methodology and results: This study was conducted through surveys covering 200 randomly sampled households (with at least 50 banana mats), each in North and South Kivu in the years 2011. Data were collected on the use of different banana parts, other than the bunch, using a structured questionnaire. All the banana parts were found to be useful, though with varying levels of importance. Commonly used parts included the leaves (green/dry), pseudostem and the peels. The corms/rhizomes were the least used parts. The most prevalent uses across plant parts included use for mulch and compost, feed for livestock, construction materials, ropes for tethering small ruminants and play items. A small fraction of the households used male buds for food, feed and medicine. Other uses included extraction of fibre, arts and crafts and use as medicine. Conclusion and application of findings: Culinary and medicinal attributes, use for art and crafts however, look to be underexploited and yet could be of great benefit to resource constrained communities. An in-depth study is recommended especially to verify and understand the culinary and medicinal attributes reported for the different plant parts in the region. Use of the male bud as a vegetable was also reported and could be promoted among communities in the region. The nutrient value of the pseudostem is high and could be promoted as animal feed in this highly populated region to enable zero grazing of small ruminants

Suppression of flavor symmetry breaking in B decay sum rules

While flavor symmetries are useful for studying hadronic B decays, symmetry relations for amplitudes and decay rates are usually violated by first order symmetry breaking corrections. We point out two cases in which first order symmetry breaking is suppressed by a small ratio of amplitudes: (1) An isospin sum rule for four $B\to K\pi$ decays, where isospin breaking is shown to be negligible. (2) An SU(3) sum rule for pairs of $B\to K\pi$ and $B\to K\eta_8$, generalized to pairs of $B\to K\pi, B\to K\eta$ and $B\to K\eta'$.Comment: 11 pages, small corrections, one reference added, submitted to Physics Letters