Shell-model Coulomb energies

Analytical expressions have been derived for the total Coulomb energies, for isoscalar, isovector and isotensor Coulomb energies, and for Coulomb energy differences of nuclei with protons and neutrons in equivalent and in different major shell regions. The approach is related to earlier theoretical treatments of Carlson and Talmi and of Hecht. A simple A-dependence is assumed to account for the increase in radius. Introducing average matrix elements for the Coulomb interactions between valence-valence, valence-core, and core-core protons in each of the six major shell regions as adjustable parameters, a global fit with 21 parameters to 288 experimental Coulomb displacement energies with 4 A A-1/3. The average decrease, however, follows approximately an A-1/3 dependence which explains the success of Coulomb energy equations based on liquid-drop models.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25057/1/0000485.pd

Properties of homogeneous and inhomogeneous mass relations

Mass equations based on third-order partial difference equations have been investigated. A test which makes use of subsets of data has been developed to study long-range extrapolations. Inherent connections with the liquid-drop model and the shell model are established. Higher-order effects in isospin, presumably due to subshell mixing and core polarization, are recognized as the origin for an inhomogeneous source term which strongly affects long-range extrapolations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25733/1/0000290.pd

Error propagation in extrapolated nuclear mass predictions

The properties of the error of the nuclear masses calculated from the transverse mass relations are analysed. The work assumes that the calculated errors of the nuclei whose masses are known experimentally behave as a sample selected randomly from a normal population having a zero mean and a standard deviation σ . It is found that the errors of the calculated masses of nuclei far from the line of beta-stability behave as c 1 d 3/2 where c 1 is a constant and d is the distance of the nucleus from the line of beta-stability. It is shown also that the errors related to the calculated mass differences behave as c 2 d 1/2 where c 2 is another constant.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45826/1/10050_2005_Article_BF01433618.pd

Measurement of alpha‐widths in 16O relevant to astrophysics

Several different α‐transfer reactions, 12C→16O, have been studied at high bombarding energies with magnetic spectrometers. Line‐widths, α‐spectroscopic factors, Sα, and reduced α‐widths, γα2 and ϑα2, have been determined for levels in 16O, including several of importance in astrophysics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87457/2/752_1.pd

Pleistocene Brawley and Ocotillo Formations: Evidence for Initial Strike-Slip Deformation Along the San Felipe and San Jacinto Fault Zones, Southern California

We examine the Pleistocene tectonic reorganization of the Pacific–North American plate boundary in the Salton Trough of southern California with an integrated approach that includes basin analysis, magnetostratigraphy, and geologic mapping of upper Pliocene to Pleistocene sedimentary rocks in the San Felipe Hills. These deposits preserve the earliest sedimentary record of movement on the San Felipe and San Jacinto fault zones that replaced and deactivated the late Cenozoic West Salton detachment fault. Sandstone and mudstone of the Brawley Formation accumulated between ∼1.1 and ∼0.6–0.5 Ma in a delta on the margin of an arid Pleistocene lake, which received sediment from alluvial fans of the Ocotillo Formation to the west-southwest. Our analysis indicates that the Ocotillo and Brawley formations prograded abruptly to the east-northeast across a former mud-dominated perennial lake (Borrego Formation) at ∼1.1 Ma in response to initiation of the dextral-oblique San Felipe fault zone. The ∼25-km-long San Felipe anticline initiated at about the same time and produced an intrabasinal basement-cored high within the San Felipe–Borrego basin that is recorded by progressive unconformities on its north and south limbs. A disconformity at the base of the Brawley Formation in the eastern San Felipe Hills probably records initiation and early blind slip at the southeast tip of the Clark strand of the San Jacinto fault zone. Our data are consistent with abrupt and nearly synchronous inception of the San Jacinto and San Felipe fault zones southwest of the southern San Andreas fault in the early Pleistocene during a pronounced southwestward broadening of the San Andreas fault zone. The current contractional geometry of the San Jacinto fault zone developed after ∼0.5–0.6 Ma during a second, less significant change in structural style

Reaction dependence of nuclear decay linewidths

Various light- and heavy-ion reactions, 20 E 8Be*(2 + , 2.9 MeV) and 16O*(1-, 9.6 MeV). Although slight differences (R) are self-consistent and indicate little if any reaction dependence (R by 20 % or more, however, and thus care must be taken in comparing decay widths inferred from nuclear reactions with those from scattering resonances. Reduced formal [alpha]-decay widths of [gamma][lambda]2 = 680 +/- 100 keV (s = 4.8 fm) and [gamma][lambda]2 = 350 +/- 50 keV(s = 5.4 fm), corresponding to [theta][lambda]2 = 0.50 and [theta][lambda]2 = 0.49 are deduced for 8Be*(2 + , 2.9 MeV) and 16O*(1-, 9.6 MeV) using the nuclear-reaction [Gamma]R values and a particular set of [alpha]-nucleus potentials.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24278/1/0000544.pd

Molecular analysis of two novel missense mutations in the GDF5 proregion that reduce protein activity and are associated with brachydactyly type C

Growth and differentiation factor 5 (GDF5) plays a central role in bone and cartilage development by regulating the proliferation and differentiation of chondrogenic tissue. GDF5 is synthesized as a preproprotein. The biological function of the proregion comprising 354 residues is undefined. We identified two families with a heterozygosity for the novel missense mutations p.T201P or p.L263P located in the proregion of GDF5. The patients presented with dominant brachydactyly type C characterized by the shortening of skeletal elements in the distal extremities. Both mutations gave rise to decreased biological activity in in vitro analyses. The variants reduced the GDF5-induced activation of SMAD signaling by the GDF5 receptors BMPR1A and BMPR1B. Ectopic expression in micromass cultures yielded relatively low protein levels of the variants and showed diminished chondrogenic activity as compared to wild-type GDF5. Interestingly, stimulation of micromass cells with recombinant human proGDF5(T201P) and proGDF5(L263P) revealed their reduced chondrogenic potential compared to the wild-type protein. Limited proteolysis of the mutant recombinant proproteins resulted in a fragment pattern profoundly different from wild-type proGDF5. Modeling of a part of the GDF5 proregion into the known three-dimensional structure of TGFbeta1 latency-associated peptide revealed that the homologous positions of both mutations are conserved regions that may be important for the folding of the mature protein or the assembly of dimeric protein complexes. We hypothesize that the missense mutations p.T201P and p.L263P interfere with the protein structure and thereby reduce the amount of fully processed, biologically active GDF5, finally causing the clinical loss of function phenotype

Coulomb displacement energies and decay widths of isobaric analog states from Sm(3He, t) at [theta] = 0[deg]

The 144,147,148,149,150,154Sm(3He, t)144,147,148,149,150,152,154Eu reactions leading to ground-state isobaric analog states (IAS) have been studied at [theta] = 0[deg] and E(3He) = 45.9 MeV. The Coulomb displacement energies decrease more rapidly than A-1/3. Approximately 110 keV of the total decrease of about 470 keV from A = 144 (spherical) to A = 154 (deformed) can be ascribed to deformation. No discontinuity is apparent at the transition from spherical to deformed shapes at N = 88-90. This is attributed to two effects: (i) rms radii increase with static deformations and with dynamical vibrations; (ii) Coulomb displacement energies depend on rms charge radii and on the rms radii of the neutron excess. The data suggest neutron deformations greater than proton deformations for A = 148 and 150 but smaller for A = 152 and 154. The IAS widths increase from ~30 keV to ~90 keV and can be attributed to mixing with the (T0-1) component of a proposed isovector giant monopole resonance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25180/1/0000619.pd

Africa’s single aviation market: The progress so far

To promote the development of air transport at the continental level, several policies were introduced, leading to the Yamoussoukro Decision (YD) in late 1999, which had the liberalisation of the intra-African aviation spaces as its main objective. Even though notable progress has been achieved towards more market-oriented aviation policies, at the pan-African level some markets are still restrictive and inconsistent with the YD, particularly with respect to the granting of 5th freedom rights. This paper aims to examine recent developments in the aviation sector in Africa, with a focus on the implementation of the YD. The obstacles to liberalisation are discussed and several measures for facilitating Africa’s move towards multilateral open skies are investigated. These include, among others, a greater collaboration and co-operation among African airlines, as well as between African airlines and foreign ones; redefinition of the role and responsibilities of different institutions which are instrumental in implementing the YD and some further issues such as ownership guidelines

Медицинские и социальные аспекты коммерческого секса

Представлены демографические, медицинские, психологические и социальные характеристики женщин, оказывающих платные сексуальные услуги. Обсуждается проблема легализации и регламентации проституции в контексте профилактики инфекций, передающихся половым путем, и заражения ВИЧ.Demographic, medical, psychological and social characteristics of women rendering sexual services are described. The problem of legalization and regulation of prostitution in the context of prevention of sexually transmitted infections and HIV is discussed