7,517 research outputs found
Does Supply Matter? Initial Supply Conditions and the Effectiveness of Conditional Cash Transfers for Grade Progression in Nicaragua
We combine administrative and survey data to examine the effect of a conditional cash transfer program on grade progression in Nicaragua from 1999–2003, putting the spotlight on initial supply side conditions and the extent to which they conditioned program effectiveness. Our principal findings are that the program had a substantial effect on grade progression and that these increased over time, even after the original intervention group stopped receiving demand-side transfers. Half of the estimated program effect on progression is accounted for by a reduction in the dropout and repetition rates of beneficiary children who were already in school when the program began. Supply side conditions were important and several of them led to heterogeneous program impacts. The program was more effective in areas with autonomous schools, suggesting flexibility at the school level better enabled schools to respond to changing demand conditions. At the same time, it was also more effective in intervention areas with poor initial supply conditions as measured by indicators of grade availability and distance to school. These were the areas with lower enrollments and grade progression before the program, and thus more room for improvement. With the analysis of child schooling in hand, we then turn to assess the “effect” of the program on school supply conditions. It is precisely in the intervention areas with poor initial school supply conditions, that the program was relatively more effective in improving school supply as measured by grade availability, number of sessions per day and number of teachers. The results suggest that initial school supply conditions do not represent insurmountable obstacles for the implementation of a conditional cash transfer program, as long as these constraints are identified at the planning stage and mechanisms put in place to deal with them during the execution stage. Our results also underscore the importance of carefully considering the integrated (demand and supply) nature of conditional-cash-transfer programs, something often overlooked in the design of these interventions and, particularly, in the impact evaluation literature.impact evaluation, conditional cash transfer, schooling, supply side
Volhard\u27s volumetric method for manganese
The purpose of this article and the data contained is an attempt to show how the percentage of manganese varies with different mounts of zinc salt present. It was also intended to determine the ratio of manganese to oxygen and zinc in the brown percipitate sic obtained upon the titration of manganese sulphate against a permanganate solution in the presence of varying quantities of zinc, but through an oversight the data is insufficient for this purpose --Introduction, page 2
Who Is an Officer under Section 16(b)--Who Knows?
The purpose of this Comment is the explore the spreading confusion and tests that are proliferating from the federal courts in their quest to resolve the dilemma of who is an officer? under section 16(b) of the 19334 Securities Exchange Act. It would seem to be a relatively simple matter to define officer for the purposes of 16(b), but there are many perplexing questions involved
A new concept for high-cycle-life LEO: Rechargeable MnO2-hydrogen
The nickel-hydrogen secondary battery system is now the one of choice for use in GEO satellites. It offers superior energy density to that of nickel-cadmium, with a lifetime that is at least comparable in terms of both cycle life and overall operating life. While the number of deep cycles required for GEO use is small, LEO satellites with long lifetimes (5 to 10 years) will require secondary battery systems allowing 30,000 to 60,000 useful cycles which are characterized by an approximately 2C charge rate and C average discharge rate. Recent work has shown that birnessite MnO2 doped with bismuth oxide can be cycled at very high rates (6C) over a very large number of cycles (thousands) at depths-of-discharge in the 85 to 90 percent range, based on two electrons, which discharge at the same potential in a flat plateau. The potential is about 0.7 V vs. hydrogen, with a cut-off at 0.6 V. At first sight, this low voltage would seem to be a disadvantage, since the theoretical energy density will be low. However, it permits the use of lightweight materials that are immune from corrosion at the positive. The high utilization and low equivalent weight of the active material, together with the use of teflon-bonded graphite for current collection, result in very light positives, especially when these are compared with those in a derated nickel-hydrogen system. In addition, the weight of the pressure vessel falls somewhat, since the dead volume is lower. Calculations show that a total system will have 2.5 times the Ah capacity of a derated nickel-hydrogen LEO battery, so that the energy density, based on 1.2 V for nickel-hydrogen and 0.7 V for MnO2-hydrogen, will be 45 percent higher for comparable cycling performance
An Unusual Case of Appendiceal Adenocarcinoma Presenting with Rectal Bleeding and Haematuria
Adenocarcinoma of the appendix is rare, usually being diagnosed intraoperatively when performing appendicectomy or at subsequent histological examination. Here we report a case with acute abdominal pain, rectal bleeding with haematuria being the presenting symptoms. Subsequent computerised tomography demonstrated a complex mass involving the ileum, right colon, sigmoid colon and bladder with inflammatory bowel disease being the most likely cause. At laparotomy a right hemicolectomy, sigmoid colectomy and partial cystectomy was performed with pathological specimens confirming an appendiceal adenocarcinoma as the primary source of the abdominal mass fistulating into adjacent structures. We conclude that although appendiceal tumours are rare – usually diagnosed at appendicectomy, they should be considered in the diagnosis of complex abdominal masses involving small bowel, large bowel and adjacent pelvic structures
Reductive cleavage of sulfones and sulfonamides by neutral organic super electron-donor (S.E.D.) reagent
The sulfonyl group finds extensive applications in organic and medicinal chemistry both in sulfonamides, popular as robust protecting groups for amines, and in sulfones. Frequently, sulfones are introduced into synthetic schemes to assist particular transformations; further progress along the synthetic route can later require the removal of a sulfone group, and this can be achieved by reductive desulfonylation or, in the special cases of α-halo- or ß-acyloxysulfones, by elimination to an alkene
Contra-thermodynamic hydrogen atom abstraction in the selective C−H functionalization of trialkylamine N‑CH3 groups
We report a simple one-pot protocol that affords functionalization of N-CH3 groups in N-methyl-N,N-dialkylamines with high selectivity over N-CH2R or N-CHR2 groups. The radical cation DABCO+•, prepared in situ by oxidation of DABCO with a triarylaminium salt, effects highly selective and contra-thermodynamic C−H abstraction from N-CH3 groups. The intermediates that result react in situ with organometallic nucleophiles in a single pot, affording novel and highly selective homologation of N-CH3 groups. Chemoselectivity, scalability, and recyclability of reagents are demonstrated, and a mechanistic proposal is corroborated by computational and experimental results. The utility of the transformation is demonstrated in the late-stage site-selective functionalization of natural products and pharmaceuticals, allowing rapid derivatization for investigation of structure−activity relationships
A Critical Analysis of the Impact of Day Care on the Pre-School Child and the Family
Maternal employment has increased dramatically over the last two decades. The result of this increase in the number of working mothers is the expanded use of day care programs for children. Examined in this paper are research findings on the impact of day-care on the child and the family. The implications of these findings for policy development are discussed.
Currently in the United States, over 50 percent of mothers work outside the home; this figure is expected to rise to 75 percent by 1990. The fastest growing segment of the working mother population is among those with children under two (Zigler and Gordon, 1982). This increasing rate of maternal employment of the last two decades has created the need for alternative arrangements for infants and young children. There is some concern among child development specialists that these alternative arrangements of care may have detrimental effects on a child\u27s social and psychological development.
Much of the concern about substitute care is based on the theory and research related to the negative effects of institutionalization on young children, (Bowlby, 1951; Spitz, 1945). This body of literature, however, tells one little about the typical forms of substitute care experienced by most children, Obviously, children generally do not experience the extreme physical and social deprivation reported on in the institutional literature (Advisory Committee on Child Development, 1976:117). Consequently, the quality of substitute care received by the majority of children is not comparable to the type of care studied in the institutional literature.
Still, the possibility remains that even with high quality care, differences may be found in the behavior and development of children as a function of the type of substitute care received. The literature reports numerous studies on the impact of various forms of substitute care; however, most of these studies are not well designed (Advisory Committee on Child Development, 1976:118). The typical form of substitute care focused on in the literature has been high quality, university based day-care settings, a form of substitute care most children do not have access to (Santrock, 1983:159). Even though the majority of these studies have weak methodological designs and are based on day-care settings not experienced by most children, some meaningful findings have emerged in the literature. This paper will focus on those relevant studies reporting on the impact of one very common form of substitute care, day-care for the pre-school child. The major emphasis of the review will be on how day-care impacts the pre-school child\u27s intellectual development, emotional development, social development, and the child\u27s family system. The authors will draw from these findings several major policy implications
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