Maternity Leave Policies and Womens Employment after Childbirth: Evidence from the United States, Britain and Japan

This paper uses microdata from the United States, Britain and Japan to examine the effects of family leave coverage on women's employment after childbirth. The United States had no national family leave legislation until 1993, but many women were covered by employer policies. Britain has had maternity leave legislation since 1978, but until 1993 only about half of working women were covered. Japan has had maternity leave legislation since 1947 but not all workers were covered. We find that young children continue to have a very negative effect on women's employment, particularly in Britain. We also find that family leave coverage increases the likelihood that a woman will return to her employer after childbirth, with a particularly marked effect in Japan. This result suggests that the recent expansions in family leave coverage are likely to lead to increased employment of women after childbirth.maternity leave, womens employment

Comparative marketing performance between the Peruvian Cooperatives and the Intermediaries: Acopagro cooperative vs. Intermediaries- a Case Study

In the Peruvian jungle, there are two main cocoa marketing channels: the intermediaries and the cooperative. For example, the Acopagro Cooperative, a Peruvian organization, has contributed to the shift from illegal crops like coca to an alternative crop like cocoa which gives small scale farmers a sustainable welfare. Despite the fact that the Acopagro cooperative benefits their members by paying a fair price, supplying technical assistance and credit, many farmers still prefer commercializing their cocoa via the intermediaries. A further analysis of cocoa prices was carried out through personal interviews and a survey made between December 2009 and January 2010, of 243 farmers in Juanjui, San Martin, Peru's main cocoa production area. The outcomes demonstrate that there is not so much difference between the cocoa price that the farmers receive from the Cooperative versus through the intermediaries. The main difference is that Acopagro cooperative divides its surplus income among its members at the end of each fiscal year. These results are consistent with previous analysis1 that proved participant farmers are better paid for their product than non-participants. Moreover, there are significant differences in the agri-marketing functions performed by each marketing channel. Farmers who prefer to commercialize via the intermediaries do not choose this marketing channel mainly due to their desire to be independent in the market or their low cocoa production. Because high economies of scale are required for large volumes of produce, the cooperative should attract small scale farmers who distribute cocoa through intermediaries to become Acopagro members in order to satisfy international market demands.Acopagro cooperative, Peruvian jungle, intermediaries, cocoa, price, agri-marketing channel, marketing channel., Agribusiness,

Experimental Studies on the Concentrations of Subjectively Equivalent Irritation for Odorants

Discussion of non-olfactory “irritation”, which is caused by the excitement of the trigeminal nerve, has important implications for odor pollution. The main purpose of this study is to work out the mechanisms for the generation of non-olfactory irritation, and the sensory characteristics of the perceived irritation. Concentrations of subjectively equivalent irritation (CE) of 16 odorous compounds were measured by the sensory test. The relations between the CE and the physicochemical properties of the compounds were shown and discussed. It was found that the CE of dissociated compounds is much lower than that of undissociated compounds. And among the dissociated compounds, the acidic ones have a lower CE than the basic compounds. The CE of acrolein, which is an unsaturated compound, was the lowest among all the compounds used in this experiment. The delay time, i.e. time until the sensation of irritation after inhaling, was longer for acrolein gas than for other gases. Therefore, the mechanism for generating sensory irritation by the acrolein gas may be different from that of other gases. From analysis on the basis of relation to some physicochemical properties, it was concluded that the electrophilic reactivity of the acrolein molecule may be related to the generation of sensory irritation. In the case of dissociated compounds, the CE is related to the dissociation constants of the compounds. In other words, the larger the acidic and basic dissociation constants (Ka and Kb) are, the lower the CE becomes. Key Words : Sensory test, Odorous irritant, Concentration for subjectively equivalent irritation, Physicochemical properties, Dissociation constan

Coupling between pore formation and phase separation in charged lipid membranes

We investigated the effect of charge on the membrane morphology of giant unilamellar vesicles (GUVs) composed of various mixtures containing charged lipids. We observed the membrane morphologies by fluorescent and confocal laser microscopy in lipid mixtures consisting of a neutral unsaturated lipid [dioleoylphosphatidylcholine (DOPC)], a neutral saturated lipid [dipalmitoylphosphatidylcholine (DPPC)], a charged unsaturated lipid [dioleoylphosphatidylglycerol (DOPG$^{\scriptsize{(-)}}$)], a charged saturated lipid [dipalmitoylphosphatidylglycerol (DPPG$^{\scriptsize{(-)}}$)], and cholesterol (Chol). In binary mixtures of neutral DOPC/DPPC and charged DOPC/DPPG$^{\scriptsize{(-)}}$, spherical vesicles were formed. On the other hand, pore formation was often observed with GUVs consisting of DOPG$^{\scriptsize{(-)}}$ and DPPC. In a DPPC/DPPG$^{\scriptsize{(-)}}$/Chol ternary mixture, pore-formed vesicles were also frequently observed. The percentage of pore-formed vesicles increased with the DPPG$^{\scriptsize{(-)}}$ concentration. Moreover, when the head group charges of charged lipids were screened by the addition of salt, pore-formed vesicles were suppressed in both the binary and ternary charged lipid mixtures. We discuss the mechanisms of pore formation in charged lipid mixtures and the relationship between phase separation and the membrane morphology. Finally, we reproduce the results seen in experimental systems by using coarse-grained molecular dynamics simulations.Comment: 34 pages, 10 figure

Artificial Extracellular Matrix Proteins Containing Phenylalanine Analogues Biosynthesized in Bacteria Using T7 Expression System and the PEGylation

In vivo incorporation of phenylalanine (Phe) analogues into an artificial extracellular matrix protein (aECM-CS5-ELF) was accomplished using a bacterial expression host that harbors the mutant phenylalanyl-tRNA synthetase (PheRS) with an enlarged binding pocket. Although the Ala294Gly/Thr251Gly mutant PheRS (PheRS**) under the control of T5 promoter allows incorporation of some Phe analogues into a protein, the T5 system is not suitable for material science studies because the amount of materials produced is not sufficient due to the moderate strength of the T5 promoter. This limitation can be overcome by using a pair of T7 promoter and T7 RNA polymerase instead. In the T7 expression system, it is difficult, however, to achieve a high incorporation level of Phe analogues, due to competition of Phe analogues for incorporation with the residual Phe that is required for synthesis of active T7 RNA polymerase. In this study, we prepared the PheRS** under T7 promoter and optimized culture condition to improve both the incorporation level of recombinant aECM protein and the incorporation level of Phe analogues. Incorporation and expression levels tend to increase in the case of p-azidophenylalanine, p-iodophenylalanine, and p-acetylphenylalanine. We evaluated the lower critical transition temperature, which is dependent on the incorporation ratio and the turbidity decreased when the incorporation level increased. Circular dichromism measurement indicated that this tendency is based on conformational change from random coil to β-turn structure. We demonstrated that polyethylene glycol (PEG) can be conjugated at reaction site of Phe analogues incorporated. We also demonstrated that the increased hydrophilicity of elastin-like sequences in the aECM-CS5-ELF made by PEG conjugation could suppress nonspecific adhesion of human umbilical vein endothelial cells (HUVEC)