435 research outputs found
Planning a Family:priorities and concerns in rural Tanzanmia
A fertility survey using qualitative and quantitative techniques described a high fertility setting (TFR 5.8) in southern Tanzania where family planning use was 16%. Current use was influenced by rising parity, educational level, age of last born child, breastfeeding status, a\ud
preference for longer than the mean birth interval (32 months), not being related to the household head, and living in a house with a tin roof. Three principal concerns amongst women were outlined from the findings. First, that there is a large unmet need for family planning services in the area particularly among teenagers for whom it is associated with induced abortion. Second, that family planning is being used predominantly for spacing but fears\ud
associated with it often curtail effective use. Third, that service provision is perceived to be lacking in two main areas ā regularity of supply, and addressing rumours and fears associated with family planning. Reproductive health interventions in the area should ultimately be more\ud
widespread and, in particular, abortion is highlighted as an urgent issue for further research.\ud
The potential for a fast and positive impact is high, given the simplicity of the perceived needs of\ud
women from this study. (Afr J Reprod Health 2004; 8[2]:111-123)\u
Stratigraphy, Structural Geology and Thermochronology of the Northern Berkshire Massif and Southern Green Mountains
Guidebook for field trips in southwestern New Hampshire, southeastern Vermont, and north-central Massachusetts: New England Intercollegiate Geological Conference, 80th annual meeting, October 14, 15 and 16, 1988, Keene, New Hampshire: Trip A-
Stratigraphy, Structural, Geology and Thermochronology of the Northern Berkshire Massif and Southern Green Mountains
Guidebook for field trips in southwestern New Hampshire, southeastern Vermont, and north-central Massachusetts: New England Intercollegiate Geological Conference, 80th annual meeting, October 14, 15 and 16, 1988, Keene, New Hampshire: Trip B-
Diagenetic incorporation of Sr into aragonitic bivalve shells: implications for chronostratigraphic and palaeoenvironmental interpretations
Aragonite is easily altered during diagenesis, therefore presumed pristine when present. In effect, beyond polymorphic transformation to calcite, alteration paths of aragonite remain poorly understood despite heavy reliance on such material to produce palaeoenvironmental and chronostratigraphic interpretations. Previous work on core material from Southern McMurdo Sound, Antarctica, showed that unlike their calcitic counterparts, seemingly unaltered aragonite shell fragments invariably produced older than expected 87Sr/86Sr ages. In this study, we pursued additional analyses of these aragonite shells and of the porewater of the core to understand this discrepancy. Aragonite mineralogy was reconfirmed and elemental mapping of shell fragments revealed growth lines within the middle layer suggestive of good preservation. The outer layer, however, showed anomalously high Sr concentrations (average 4Ā·5Ā Ā±Ā 0Ā·6 mole% SrCO3; ca 25Ā mmolĀ molā1 Sr/Ca) and was depleted in 18O and 13C compared to the middle layer, both features inconsistent with pristine material. The Ī“18O values and Sr concentrations of the porewater were used to model outer layer compositions reasonably well. Coincidentally, porewater Sr isotope composition was in general agreement with the age model of the core only at the aragoniteābearing interval suggesting that Srāisotopic disequilibrium between porewater and the carbonates was the rule rather than the exception in the core. The Sr isotope compositions of the aragonite shells are most likely the result of early diagenesis as suggested by the inconsistent O and C isotope compositions between shell layers and the anomalously high Sr concentrations. We conclude that knowledge of Sr concentration and distribution in shells is critical to determine the viability of Sr stratigraphy and the scale at which it may be applied. Reliance on traditional indicators of lack of alteration, such as cathodoluminescence, MnāFe concentration, and the presence of labile mineralogies to assert chronostratigraphic and palaeoenvironmental questions may produce erroneous conclusions due to obscurely altered material.Compositional map of Sr over BSE image and representative SEM detail overlay from a Miocene aragonitic Retrotape andrillorum bivalve, Southern McMurdo Sound, Antarctica. Signs of apparent good preservation, such as the presence of growth bands and the preservation of crystalline structure and mineralogy, appear in contrast to anomalously high Sr concentrations. Results suggest that relying solely on traditional methods to rule out diagenesis may in some cases lead to erroneous conclusions due to obscure alteration patterns.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113152/1/dep23.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113152/2/dep23-sup-0003-AppendixS3.pd
RELATIONSHIP OF PARITY AND SOME BREEDING CHARACTERISTICS IN RED SOKOTO GOATS
Data on some breeding characteristics; litter size (LS) kidding interval (KI), dam mating weight (Mwt), Kidding weight(Kwt) and 60 day post kidding weight(60dPKwt) as well as body size characteristics(HW,BL and HG) collected from 1000 Red Sokoto does of small holder farmers in Kano State, Nigeria, were analysed to estimate the relationships amongst these characteristics themselves and between them with parity of dam. The mean LS, KI, Mwt, Kwt and 60dPKwt were 1.45, 6.90 months 20.4kg, 24.7kg, and 23.0kg, respectively. The mean height-at-withers (HW), body length (BL) and chest girth (CG) were 54.4cm, 59.0 and 65.8cm, respectively. The correlations amongst all the measured characteristics were positive and significant (P<0.01 ā 0.05; r = 0. 32- 0.93). The correlation between Mwt and Kwt was the strongest (r = 0.93). The relationships between parity and all the characteristics measured was positive and highly significant (P<0.01; r = 0.49-0.87) The correlation of parity with mating weight (Mwt) was the strongest ( r = 0.87). The prediction equations of body weight at different stages of growth using combinations of linear body measurements were significant (P<0.01) However, the prediction equation of 60 day post- kidding weight using the combination of the linear body measurements (HW, BL, CG) was the best ( R2 = 72.0%) followed by kidding weight ( R2 = 55.4%) and mating weight (R2 = 54.76%), respectively. Therefore, the equation for the prediction of 60 day post kidding weight (60d PKwt) using the combination of linear body measurements (HW, BL, CG) adequately explained about 72% of the variation in the 60d PKwt of the does. This implies that combination of linear body measurements can be used with high degree of reliability to estimate body weight in Red Sokoto goats
Food security through virus indexing, tissue culture and genetic engineering of underutilized crops
The Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction across a tunneling junction out of equilibrium
The Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between two magnetic
- spin impurities across a tunneling junction is studied when the system
is driven out of equilibrium through biasing the junction. The nonequilibrium
situation is handled with the Keldysh time-loop perturbation formalism in
conjunction with appropriate coupling methods for tunneling systems due to
Caroli and Feuchtwang. We find that the presence of a nonequilibrium bias
across the junction leads to an interference of several fundamental
oscillations, such that in this tunneling geometry, it is possible to tune the
interaction between ferromagnetic and antiferromagnetic coupling at a fixed
impurity configuration, simply by changing the bias across the junction.
Furthermore, it is shown that the range of the RKKY interaction is altered out
of equilibrium, such that in particular the interaction energy between two
slabs of spins scales extensively with the thickness of the slabs in the
presence of an applied bias.Comment: 38 pages revtex preprint; 5 postscript figures; submitted to Phys.
Rev.
Age and petrogenesis of the Sarmiento ophiolite complex of southern Chile
Zircon fractions separated from fine-grained plagiogranites, interpreted to be cogenetic with the mafic rocks of the Sarmiento ophiolite complex in southern Chile, yield slightly to grossly discordant age patterns for which the lower concordia intercept U-Pb ages of 140.7 +/- 0.7 Ma (Lolos Fjord) and 137.1 +/- 0.6 Ma (Encuentro Fjord) are well constrained. These dates are interpreted as formation ages for the northern portion of the igneous floor of the Rocas Verdes basin, and they are younger than the age of 150 Ma determined for a more southern portion of the floor of this basin on South Georgia Island. Coarse-grained trondjemites within the gabbro units of the Sarmiento complex yield a lower concordia intercept U-Pb age of 147 +/- 10 Ma and a poorly defined upper intercept reflecting an inherited zircon component, possibly of Proterozoic age. These rocks are interpreted as remobilized fragments of country rocks entrapped within the essentially mantle-derived rocks of the ophiolite complex.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29957/1/0000318.pd
Hf- and O-isotope data from detrital and granitoid zircons reveal characteristics of the PermianāTriassic magmatic belt along the Antarctic sector of Gondwana
PermianāTriassic strata in the Transantarctic Mountains and West Antarctica carry a significant detrital component derived from a contemporaneous magmatic belt along the Gondwana margin. Hf- and O-isotope characteristics were determined for near-contemporaneous (as shown by U-Pb zircon geochronology) detrital igneous zircons in Upper Permian and Triassic sandstones. Zircons from six granitoids in the contemporaneous magmatic belt were also analyzed for Hf and O isotopes in order to gain insight into the potential detrital zircon sources. Although the ages of these granitoids only loosely correspond with the depositional ages of the sandstones, the initial ĪµHf and Ī“18O isotope compositions for these igneous zircon grains, in general, overlap those recorded for the detrital igneous zircon grains. Results demonstrate a range of ĪµHf and Ī“18O values. Features of particular interest are the very low Ī“18O values in two of the granitoids, and similar low values also recorded in the detrital igneous zircons in two sandstones. The distribution of PermianāTriassic granitoids must be much greater than is apparent from the existing outcrops in the extensively ice-covered region. The Permian and one of the Triassic granitoids have Hf-isotope characteristics similar to the Cretaceous granites and DevonianāCarboniferous plutons of West Antarctica, whereas the other Triassic granite differs from both. Importantly, the zircon isotopic data from the PermianāTriassic rocks suggest that an Hf-defined Upper Mesoproterozoic lithosphere underlies much of the magmatic belt
Proliferation and shoot recovery among the East African highland banana
Production of East African highland banana (EA-AAA banana) ( Musa
spp.) is limited by scarcity of planting materials, attributable to
their low natural proliferation ability. Under natural field
conditions, the EA-AAA bananas greatly differ in suckering ability. In
vitro micropropagation has been adopted as an alternative means for
production of banana planting materials. In this study, the in vitro
proliferation potential of seven EA-AAA banana cultivars, with
different suckering ability was determined on Murashige and Skoog (MS)
medium, to enhance development of micropropagation protocols for their
multiplication. Commonly cultivated non EA-AAA banana cultivars were
used to compare proliferation of the seven EA-AAA cultivars. There was
a wide variation in the number and morphology of shoots and buds
produced by the different cultivars. The EA-AAA banana cultivars
produced 3-4 new shoots in each subculture cycle, and 57-169
recoverable shoots from one starting shoot-tip explant in 18 weeks.
Non-EA-AAA banana cultivars, namely Sukali Ndizi (AAB) and Yangambi Km5
(AAA), showed higher proliferation levels, 5 and 9 shoots, from each
subculture cycle and 322 and 352 recoverable shoots, respectively. The
EA-AAA banana cultivars showed higher efficiency to produce recoverable
shoots from shoot buds (53 - 66% except for cv. Kabula at 36%) compared
to Sukali Ndizi (52%) and Yangambi Km5 (32%). The study demonstrates
the potential of in vitro approach for production of banana planting
materials. In vitro proliferation ability and in particualr efficiency
to produce recoverable shoots of the different EA-AAA banana cultivars
could be improved by varying the culture conditions during the
subsequent subculture cycles.La production de la banane (EA-AAA banana) ( Musa spp.) dans les
montagnes de l\u2019Afrique de l\u2019Est est limit\ue9e par le
manque du mat\ue9riel de plantation suite \ue0 leur base
capacit\ue9 de prolif\ue9ration. En conditions naturelles au
champs, les bananes EA-AAA different consid\ue9rablement en leur
capacit\ue9 de succion. La propagation in vitro a \ue9t\ue9
adopt\ue9e comme moyen alt\ue9rnatif pour la production du
mat\ue9riel de plantation de la banana. Dans cette \ue9tude, le
potentiel de prolif\ue9ration in vitro de sept cultivars de banana
EA-AAA de capacit\ue9 de succion diff\ue9rente, \ue9tait
d\ue9termin\ue9 sur les media de Murashige et Skoog (MS), afin
d\u2019am\ue9liorer le d\ue9veloppement de protocoles de
micropropagation pour leur multiplication. Des cultivars
commun\ue9ment cultiv\ue9s autre que la banana EA-AAA \ue9taient
utilis\ue9s pour faire la comparaison avec la proliferation des sept
cultivars EA-AAA. Il y\u2019avait eu une large variation dans le
nombre et la morphologie des pousses et bourgeons de diff\ue9rents
cultivars. Les cultivars de bananes EA-AAA ont produit 3-4 nouvelles
pousses dans chaque cycle de sous culture et 57-169 pousses
recouvrables d\u2019un explant de pousse dans 18 semaines. Les
cultivars de bananes non-EA-AAA nom\ue9ment Sukali Ndizi (AAB) and
Yangambi Km5 (AAA), ont montr\ue9 de niveaux \ue9lev\ue9s de
proliferation, 5 et 9 pousses de chaque cycle de sous culture et 322 et
352 pousses recouvrables, respectivement. Les cultivars de bananes
EA-AAA ont montr\ue9 un niveau d\u2019efficacit\ue9
\ue9lev\ue9 quant \ue0 la production de de pousses recouvrables
\ue0 partir de bourgeons (3566% except\ue9 pour cv. Kabula \ue0
36%) en comparaison avec Sukali Ndizi (52% et Yangambi km5 (32%). Cette
\ue9tude d\ue9montre le potentiel de production du mat\ue9riel de
plantation de la banana par l\u2019approche in vitro. La capacit\ue9
de proliferation in vitro et en particulier l\u2019efficacit\ue9 de
produire de pousses recouvrables de diff\ue9rents cultivars pourrait
\ueatre am\ue9lior\ue9 en variant les conditions de cultrure
Durant les cycles sous culturales
- ā¦