Arbitraging a Discriminatory Labor Market: Black Workers at the Ford Motor Company, 1918–1947

The 1918-47 employee records of the Ford Motor Company provide a rare opportunity to study a firm willing to hire black workers when similar firms would not. The evidence suggests that Ford did profit from discrimination elsewhere, but not by paying blacks less than whites. An apparent "wage-equity constraint" prevailed, resulting in virtually no racial variation in wages inside Ford. An implication was that blacks quit Ford jobs less often than whites, holding working conditions constant. Arbitrage profit came from exploiting this nonwage margin, as Ford placed blacks in hot, dangerous foundry jobs where quit rates were generally high

Diagnóstico de prenhez em cabras e ovelhas

Two hundred and three does and 112 ewes submitted to breeding season from October 1 to November 29 in 1980, were used for an experiment to test efficiency of ultrasonic method in diagnosing pregnancy. The results are presented according to species and breeds of dams as also according to the age of fetus, when the diagnosis was carried out. In goats, when the mean age of fetus was 109, 5 days, the diagnosis was accurate in 93,10 percent cases; 84,27 percent in case of pregnant and 100 percent in case of non-pregnant does. In ewes, at 92,2 days mean age of fetus, overall accuracy was 91,95 percent; 100 percent in case of pregnant and 50,09 percent in non-pregnant ewes. Thus, in goats the rate of accuracy was more in pregnant females, whereas in sheep it was more in non-pregnant female. The minimum age of fetus at which pregnancy diagnosis was possible was 53 days in ewes and 86 days in does.Duzentas e três cabras e 112 ovelhas, todas submetidas à estação reprodutiva de 1/10/80 a 29/11/80, no município de Sobral, CE, foram utilizadas neste trabalho, visando o diagnóstico de prenhez pelo método de ultra-som. Os resultados estão apresentados por espécie e taça das matrizes e idade fetal, na qual o diagnóstico foi executado. Nas cabras, o índice de certeza do diagnóstico, em média, foi de 93,10% sendo 84,27 e 100% para as fêmeas diagnosticadas como prenhes e não-prenhes, respectivamente, aos 109,5 dias de gestação. Nas ovelhas, o diagnóstico certo, em média, foi de 91,95%, sendo de 100 e 50,09% para ovelhas diagnosticadas como prenhes e não-prenhes, respectivamente, à idade fetal de 92,20 dias. Na determinação da gestação em caprinos, houve mais erro ao diagnosticar cabras prenhes e, em ovinos, ovelhas não-prenhes. Em ovinos e caprinos, à idade fetal de 53 e 86 dias, respectivamente, foi possível diagnosticar positivamente a gestação

Diagnóstico de prenhez em cabras e ovelhas

Two hundred and three does and 112 ewes submitted to breeding season from October 1 to November 29 in 1980, were used for an experiment to test efficiency of ultrasonic method in diagnosing pregnancy. The results are presented according to species and breeds of dams as also according to the age of fetus, when the diagnosis was carried out. In goats, when the mean age of fetus was 109, 5 days, the diagnosis was accurate in 93,10 percent cases; 84,27 percent in case of pregnant and 100 percent in case of non-pregnant does. In ewes, at 92,2 days mean age of fetus, overall accuracy was 91,95 percent; 100 percent in case of pregnant and 50,09 percent in non-pregnant ewes. Thus, in goats the rate of accuracy was more in pregnant females, whereas in sheep it was more in non-pregnant female. The minimum age of fetus at which pregnancy diagnosis was possible was 53 days in ewes and 86 days in does.Duzentas e três cabras e 112 ovelhas, todas submetidas à estação reprodutiva de 1/10/80 a 29/11/80, no município de Sobral, CE, foram utilizadas neste trabalho, visando o diagnóstico de prenhez pelo método de ultra-som. Os resultados estão apresentados por espécie e taça das matrizes e idade fetal, na qual o diagnóstico foi executado. Nas cabras, o índice de certeza do diagnóstico, em média, foi de 93,10% sendo 84,27 e 100% para as fêmeas diagnosticadas como prenhes e não-prenhes, respectivamente, aos 109,5 dias de gestação. Nas ovelhas, o diagnóstico certo, em média, foi de 91,95%, sendo de 100 e 50,09% para ovelhas diagnosticadas como prenhes e não-prenhes, respectivamente, à idade fetal de 92,20 dias. Na determinação da gestação em caprinos, houve mais erro ao diagnosticar cabras prenhes e, em ovinos, ovelhas não-prenhes. Em ovinos e caprinos, à idade fetal de 53 e 86 dias, respectivamente, foi possível diagnosticar positivamente a gestação

Frequência e duração do ciclo estral e do estro em caprinos sem raça definida (SRD) no nordeste tropical do Brasil

In a one-year study conducted in the tropical, semi-and region of Northeast of Brazil, 30 genetically non-descript (SRD) does, 1.5 - 2.0year old, were grazed on native range (2.3 ha/head/year) with ad libitum water, salt and bone meal. Fourteen goats were supplemented with green chopped elephant grass (P. purpureum Schum.) at the proportion of 2% dry matter in relation to the mean body weight of goats, during the most critical part of the dry season (November 2 to February 26). The remaining 16 goats served as controls. The 480estrous cycles and 511 estrous period lengths were compared for the wet season (February 27 to July 10) and dry season (July 11 to February 26) as well as for level of feed. The incidence of estrus classified by month was evenly distributed throughout the year with a mean of 8.3% and 7% to 9.8% range (P>0.05) monthly variation. The average lengths of estrous periods were 55.8 vs 57.4 hours (P>0.05) and the estrous cycles 20.9 vs 21.5 days (P>0.05) for non-supplemented and supplemented groups, respectively. The same traits between wet and dry seasons were 62.0 vs 51.2 hours (P0,05). A duração média do estro foi de 55.8 e 57,4 horas (P>0,05), e a do ciclo estral foi de 20$ e 21,5 dias (P>0,05) para as cabras não suplementadas e suplementadas, respectivamente. A duração do estro foi de 62,0 e 51.2 horas (P <0,05) e do ciclo estral de 20,6 e 21,8 dias (P<0,06) para as estações chuvosa e seca, respectivamente

Efeito do manejo nutricional sobre a taxa de ovulação e de folículos, no decorrer do ano, em ovinos deslanados no Nordeste do Brasil

The objective of this study was to determine the ovarian activity of Morada Nova, Santa Inês and Brazilian Somalis hairy breed ewes. Seventy two animals were divided in two groups, G I and G II, 36 each, and placed on two nutritional treatments: confinement and native pasture. These groups were again arranged in a factorial design (3x2) according to the breeds. During one year the ewes were submitted to monthly endoscopy to verify the presence of follicles and luteal phase. The ewes of Morada Nova breed showed a higher ovulation rate (P<0.0001), frequency (P<0.05) number of follicles (P<0.05) and multiple ovulations (P<0.05) than those of Santa Inês and Brazilian Somalis. The sheep mantained on native pasture presented a better ovulation rate (P<0.001) than those of confinement. Similare differences could be observed between the rainy and dry seasons. During the rainy season no differences were observed between the breeds. The determination of the rate and frequency of ovulation, during a year, enabled better understanding of the potential of the sexual activity of the hairy sheep of Northeast Brazil.Ovinos deslanados das raças Morada Nova, Santa Inês e Somalis brasileira, foram submetidos a endoscopias mensais, a fim de verificar a atividade ovariana, quanto a presença de folículos e corpos lúteos no decorrer do ano. Setenta e duas fêmeas foram divididas em dois grupos, G I (36) em confinamento e G II (36) na pastagem nativa. Os grupos G I te G II foram ainda divididos conforme raças, sendo doze animais de cada raça por grupo. Os animais da raça Morada Nova mostraram maior taxa e frequência de ovulação bem como maior número de folículos (P<0,0001, P<0,05 e P<0,05 respectivamente) do que os da raça Somalis brasileira e Santa Inês. Ainda os animais da raça Morada Nova apresentaram maior (P<0,05) número de fêmeas com ovulações múltiplas. O grupo em pastagem nativa proporcionou maior (P< 0,001) taxa de ovulação do que o grupo em confinamento, o mesmo ocorrendo com o período chuvoso em relação ao seco. No período chuvoso não houve diferença na taxa de ovulação nos animais das três raças. O conhecimento da taxa e frequência de ovulação, durante o ano, permitiu revelar o potencial da atividade sexual das raças de ovinos deslanados criados no Nordeste do Brasil

Measurements of acoustic scattering from zooplankton and oceanic microstructure using a broadband echosounder

© 2009 The Authors. This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License. The definitive version was published in ICES Journal of Marine Science: Journal du Conseil 67 (2010): 379-394, doi:10.1093/icesjms/fsp242.In principle, measurements of high-frequency acoustic scattering from oceanic microstructure and zooplankton across a broad range of frequencies can reduce the ambiguities typically associated with the interpretation of acoustic scattering at a single frequency or a limited number of discrete narrowband frequencies. With this motivation, a high-frequency broadband scattering system has been developed for investigating zooplankton and microstructure, involving custom modifications of a commercially available system, with almost complete acoustic coverage spanning the frequency range 150–600 kHz. This frequency range spans the Rayleigh-to-geometric scattering transition for some zooplankton, as well as the diffusive roll-off in the spectrum for scattering from turbulent temperature microstructure. The system has been used to measure scattering from zooplankton and microstructure in regions of non-linear internal waves. The broadband capabilities of the system provide a continuous frequency response of the scattering over a wide frequency band, and improved range resolution and signal-to-noise ratios through pulse-compression signal-processing techniques. System specifications and calibration procedures are outlined and the system performance is assessed. The results point to the utility of high-frequency broadband scattering techniques in the detection, classification, and under certain circumstances, quantification of zooplankton and microstructure.The work was supported by the US Office of Naval Research (Grant # N000140210359)

Oceanographic barriers, divergence, and admixture : phylogeography and taxonomy of two putative subspecies of short-finned pilot whale

Funding:Commander, U.S. Pacific Fleet Environmental Readiness Division and NMFS Pacific Islands Fisheries Science Center; NMFS West Coast Region; Scripps Institution of Oceanography Edna Bailey Sussman Research Fellowship; and Woods Hole Oceanographic Institution.Genomic phylogeography plays an important role in describing evolutionary processes and their geographic, ecological, or cultural drivers. These drivers are often poorly understood in marine environments, which have fewer obvious barriers to mixing than terrestrial environments. Taxonomic uncertainty of some taxa (e.g., cetaceans), due to the difficulty in obtaining morphological data, can hamper our understanding of these processes. One such taxon, the short‐finned pilot whale, is recognized as a single global species but includes at least two distinct morphological forms described from stranding and drive hunting in Japan, the “Naisa” and “Shiho” forms. Using samples (n = 735) collected throughout their global range, we examine phylogeographic patterns of divergence by comparing mitogenomes and nuclear SNP loci. Our results suggest three types within the species: an Atlantic Ocean type, a western/central Pacific and Indian Ocean (Naisa) type, and an eastern Pacific Ocean and northern Japan (Shiho) type. mtDNA control region differentiation indicates these three types form two subspecies, separated by the East Pacific Barrier: Shiho short‐finned pilot whale, in the eastern Pacific Ocean and northern Japan, and Naisa short‐finned pilot whale, throughout the remainder of the species' distribution. Our data further indicate two diverging populations within the Naisa subspecies, in the Atlantic Ocean and western/central Pacific and Indian Oceans, separated by the Benguela Barrier off South Africa. This study reveals a process of divergence and speciation within a globally‐distributed, mobile marine predator, and indicates the importance of the East Pacific Barrier to this evolutionary process.PostprintPeer reviewe

Abiotic ammonium formation in the presence of Ni-Fe metals and alloys and its implications for the Hadean nitrogen cycle

Experiments with dinitrogen-, nitrite-, nitrate-containing solutions were conducted without headspace in Ti reactors (200°C), borosilicate septum bottles (70°C) and HDPE tubes (22°C) in the presence of Fe and Ni metal, awaruite (Ni80Fe20) and tetrataenite (Ni50Fe50). In general, metals used in this investigation were more reactive than alloys toward all investigated nitrogen species. Nitrite and nitrate were converted to ammonium more rapidly than dinitrogen, and the reduction process had a strong temperature dependence. We concluded from our experimental observations that Hadean submarine hydrothermal systems could have supplied significant quantities of ammonium for reactions that are generally associated with prebiotic synthesis, especially in localized environments. Several natural meteorites (octahedrites) were found to contain up to 22 ppm Ntot. While the oxidation state of N in the octahedrites was not determined, XPS analysis of metals and alloys used in the study shows that N is likely present as nitride (N3-). This observation may have implications toward the Hadean environment, since, terrestrial (e.g., oceanic) ammonium production may have been supplemented by reduced nitrogen delivered by metal-rich meteorites. This notion is based on the fact that nitrogen dissolves into metallic melts