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Sample records for additional sex combs-like

  1. Biased diffusion in three-dimensional comb-like structures.

    PubMed

    Berezhkovskii, Alexander M; Dagdug, Leonardo; Bezrukov, Sergey M

    2015-04-07

    In this paper, we study biased diffusion of point Brownian particles in a three-dimensional comb-like structure formed by a main cylindrical tube with identical periodic cylindrical dead ends. It is assumed that the dead ends are thin cylinders whose radius is much smaller than both the radius of the main tube and the distance between neighboring dead ends. It is also assumed that in the main tube, the particle, in addition to its regular diffusion, moves with a uniform constant drift velocity. For such a system, we develop a formalism that allows us to derive analytical expressions for the Laplace transforms of the first two moments of the particle displacement along the main tube axis. Inverting these Laplace transforms numerically, one can find the time dependences of the two moments for arbitrary values of both the drift velocity and the dead-end length, including the limiting case of infinitely long dead ends, where the unbiased diffusion becomes anomalous at sufficiently long times. The expressions for the Laplace transforms are used to find the effective drift velocity and diffusivity of the particle as functions of its drift velocity in the main tube and the tube geometric parameters. As might be expected from common-sense arguments, the effective drift velocity monotonically decreases from the initial drift velocity to zero as the dead-end length increases from zero to infinity. The effective diffusivity is a more complex, non-monotonic function of the dead-end length. As this length increases from zero to infinity, the effective diffusivity first decreases, reaches a minimum, and then increases approaching a plateau value which is proportional to the square of the particle drift velocity in the main tube.

  2. Bottlebrush and comb-like elastomers as ultra-soft electrical and acoustically active materials

    NASA Astrophysics Data System (ADS)

    Daniel, William; Vatankhah-Varnosfaderani, Mohammad; Pandya, Ashish; Burdynska, Joanna; Morgan, Benjamin; Everhart, Matthew; Matyjaszewski, Krzysztof; Dobrynin, Andrey; Rubinstein, Michael; Sheiko, Sergei; UNC MIRT Team

    Without swelling in a solvent, it is challenging to obtain materials with a modulus below 105 Pa, which is dictated by chain entanglements. We show that macromolecules can be disentangled by dense grafting of side chains to long polymer chains. The bottlebrush and comb-like architectures demonstrate a unique combination of flexibility and network dilution, leading to significant decrease of the entanglement modulus (Ge) and increase of extensibility. Following theoretical predictions, it has been shown that the Ge is controlled by the polymerization degrees of sidechains (nsc) and grafting spacer (ng) as Ge ~ (ng /nsc) 1 . 5 . Using the reduced entanglement density, we developed solvent-free elastomers with moduli on the order of 100 Pa and excellent extensibility. Using bottlebrush architectures we have developed PDMS dielectric actuators with high deformation at low electric field strength. Additionally strong acoustic adsorption leads to materials showing shape and volume control in light opaque environments. NSF (DMR 1409710, DMR 1122483, DMR 1407645, and DMR 1436201).

  3. Degradable, pH-sensitive, membrane-destabilizing, comb-like polymers for intracellular delivery of nucleic acids.

    PubMed

    Lin, Yen-Ling; Jiang, Guohua; Birrell, Lisa K; El-Sayed, Mohamed E H

    2010-09-01

    This report describes the design and synthesis of a new series of degradable, pH-sensitive, membrane-destabilizing, comb-like polymers that can enhance the intracellular delivery of therapeutic nucleic acids. These comb-like polymers are based on a diblock polymer backbone where the first block is a copolymer of pH-sensitive ethyl acrylic acid (EAA) monomers and hydrophobic butyl methacrylate (BMA) or hexyl methacrylate monomers. The second block is a homopolymer of N-acryloxy succinimide (NASI) or ss-benzyl l-aspartate N-carboxy-anhydride (BLA-NCA) monomers, which are functionalized to allow controlled grafting of hydrophobic HMA and cationic trimethyl aminoethyl methacrylate (TMAEMA) copolymers via acid-labile hydrazone linkages. These comb-like polymers displayed high hemolytic activity in acidic solutions, which increased with the increase in polymer concentration. All comb-like polymers degraded into small fragments upon incubation in an acidic solution (pH 5.8) due to hydrolysis of the hydrazone linkages connecting the hydrophobic/cationic grafts to the polymer backbone. Comb-like polymers successfully complexed anti-GAPDH siRNA molecules into serum- and nuclease-stable particles, which successfully silenced GAPDH expression at both the mRNA and protein levels. These results collectively indicate the potential of these new comb-like polymers to serve as vehicles for effective intracellular delivery of therapeutic nucleic acids.

  4. Probing the association behavior of poly(ethylene glycol)-based amphiphilic comb-like polymer in NaCl solution.

    PubMed

    Basak, P; Nisha, C K; Manorama, S V; Maiti, Souvik; Jayachandran, K N

    2003-06-15

    The effect of salt on the associative behavior of intramolecular aggregates obtained from poly(ethylene glycol)-based amphiphilic comb-like polymers in aqueous medium at pH 6.2 has been investigated by surface tension, fluorescence probe, dynamic light-scattering, and viscometry techniques. Results reveal that the addition of salt screens the electrostatic repulsion between the charges along the polymer backbone in the aggregates and consequently (1) reduces the surface activity at the air/water interface, (2) leads to the contraction of the polymer backbone, and (3) reduces the hydrodynamic sizes of the aggregates. In contrast, the hydrophobicity of the aggregates remains unperturbed.

  5. Lithium battery with solid polymer electrolyte based on comb-like copolymers

    NASA Astrophysics Data System (ADS)

    Daigle, Jean-Christophe; Vijh, Ashok; Hovington, Pierre; Gagnon, Catherine; Hamel-Pâquet, Julie; Verreault, Serge; Turcotte, Nancy; Clément, Daniel; Guerfi, Abdelbast; Zaghib, Karim

    2015-04-01

    In this paper we report on the synthesis of comb-like copolymers as solid polymer electrolytes (SPE). The synthesis involved anionic polymerization of styrene (St) and 4-vinylanisole (VA) as the followed by grafting of poly(ethylene glycol) monomethyl ether methacrylate (PEGMA) by Atom Transfer Radical Polymerization (ATRP). The comb-like copolymer's structure was analyzed by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The membranes were made by solvent casting and the morphologies were analyzed by atomic forces microscopy (AFM) and scanning electron microscopy (SEM). We observed that a nano and micro phase separation occurs which improves ionic conductivity. The ionic conductivities were determined by AC Impedance, which showed that the SPEs have good conductivities (10-5 Scm-1) at room temperature owing to the negligible values (<10 kJ mol-1) of the activation energies for conductivity. The batteries with these polymers exhibit a capacity of 146 mAh g-1 at C/24, and no evidence of degradation after intense cycling was observed. However, poor cycle life was observed at C/6 and C/3, which is a consequence of several factors. We partially explain that behavior by arguing that whereas PEO lightly "solvates" Li+ thus slowing Li-ion mobility, and PEGMA chains "solvate" Li ions too strongly, trapping and inhibiting their mobility.

  6. Generating controllable frequency-comb-like structures in terahertz range via Rabi sidebands

    NASA Astrophysics Data System (ADS)

    Filin, Alex; Romanov, Dmitri; Levis, Robert

    2013-05-01

    When broad, coherent Rabi sidebands are invoked by a moderately intense picosecond laser pulse, they typically exhibit spectral interference fringes. We demonstrate the possibility of controlling this fringe pattern toward a comb-like structure. We investigated the influence of the driving pulse (normalized to 1 ps FWHM) shape parameters on the structural characteristics of the sideband spectra: the spectrum envelope, the fringe contrast, and the fringe spacing variation. The envelope was found to depend drastically on the sharpness of the driving pulse, that is, on the rate at which the temporal distance between the leading and trailing edges grows away from the pulse maximum. Increase in this parameter effectively flattens the envelope. The fringe contrast, that is, the maximum-to-minimum difference, depends strongly on the asymmetry of the driving pulse. The imbalance between the driving and the trailing edges leads to fast decrease of the contrast. The variation of inter-peak distance within a sideband was controlled using super-Gaussian shape of the driving pulse. While for the Gaussian pulse the inter-peak distance increases almost 5 times over the interval from 1.60 to 1.66 eV (in the case of oxygen), sufficiently super-Gaussian shape leads to almost equidistant fringes (comb-like spectrum). Support from the Air Force Office of Scientific Research, Grant No. N00014-10-0293, is gratefully acknowledged.

  7. From normal to anomalous diffusion in comb-like structures in three dimensions.

    PubMed

    Berezhkovskii, Alexander M; Dagdug, Leonardo; Bezrukov, Sergey M

    2014-08-07

    Diffusion in a comb-like structure, formed by a main cylindrical tube with identical periodic dead ends of cylindrical shape, occurs slower than that in the same system without dead ends. The reason is that the particle, entering a dead end, interrupts its propagation along the tube axis. The slowdown becomes stronger and stronger as the dead end length increases, since the particle spends more and more time in the dead ends. In the limiting case of infinitely long dead ends, diffusion becomes anomalous with the exponent equal to 1/2. We develop a formalism which allows us to study the mean square displacement of the particle along the tube axis in such systems. The formalism is applicable for an arbitrary dead end length, including the case of anomalous diffusion in a tube with infinitely long dead ends. In particular, we demonstrate how intermediate anomalous diffusion arises when the dead ends are long enough.

  8. Aerodynamics of a comb-like plate mimicking a fairyfly wing

    NASA Astrophysics Data System (ADS)

    Lee, Seunghun; Jung, Cheolgyun; Kim, Daegyoum

    2016-11-01

    There have been many studies on the aerodynamics of a wing with smooth surface in a wide range of the Reynolds number. Unlike smooth wings of common insects or birds, however, fairyfly has a distinctive wing geometry; a frame with several bristles. Motivated by the peculiar wing geometry of the fairyfly we experimentally investigated the fluid dynamics of a translating comb-like wing in a wide range of Reynolds number in O(1) - O(103). We conducted the same experiment in several fluids of different viscosities in order to investigate the effects of the Reynolds number on the aerodynamic performance. Aerodynamic force of various wing shapes was measured, and it was correlated with the flow structure generated by the wing. Corresponding author.

  9. Synthesis of comb-like copolymers from renewable resources: Itaconic anhydride, stearyl methacrylate and lactic acid

    NASA Astrophysics Data System (ADS)

    Shang, Shurui

    The synthesis and properties of comb-like copolymers and ionomers derived from renewable resources: itaconic anhydride (ITA), stearyl methacrylate (SM) and lactic acid (LA) are described. The copolymers based on ITA and SM (ITA-SM) were nearly random with a slight alternating tendency. The copolymers exhibited a nanophase-separated morphology, with the stearate side-chains forming a bilayer, semi-crystalline structure. The crystalline side-chains suppressed molecular motion of the main-chain, so that a glass transition temperature (Tg) was not resolved unless the ITA concentration was sufficiently high so that Tg > the melting point (Tm). The softening point and modulus of the copolymers increased with the increasing ITA concentration, but the thermal stability decreased. The ITA moiety along the main chain of the copolymers was neutralized with metal acetates to produce Na-, Ca- and Zn- random ionomers with comb-like architectures. In general, the incorporation of the ionic groups increased the Tg and suppressed the crystallinity of the side-chain packing. Ionomers with high SM side-chain density had two competing driving forces for self-assembled nano-phase separation: ionic aggregation and side-chain crystalline packing. Upon neutralization, a morphological transition from semi-crystalline lamella to spherical ionic aggregation was observed by small angle X-ray scattering (SAXS) analysis and transmission electron microscopy (TEM). Thermomechanical analysis revealed an increasing resistance to penetration deformation with an increasing degree of neutralization and an apparent rubbery plateau was observed above Tg. A controlled transesterification of PLA in glassware was an effective way to prepare a methacrylate functionalized PLA macromonomer with controlled molecular weight, which was used to synthesize a variety of copolymers. The copolymerization of this functionalized PLA macromonomer with ITA totally suppressed the side-chain crystallinity for the PLA chain

  10. Interdigitated comb-like electrodes for continuous separation of malignant cells from blood using dielectrophoresis.

    PubMed

    Alazzam, Anas; Stiharu, Ion; Bhat, Rama; Meguerditchian, Ari-Nareg

    2011-06-01

    In this paper, a method for continuous flow separation of circulating malignant cells from blood in a microfluidic device using dielectrophoresis is discussed. Separation of MDA231 breast cancer cells after mixing with normal blood cells was achieved with a level of accuracy that enabled precise counting of the malignant cells, separation and eventually, sub-culturing. MDA231 cells were separated from the blood to a daughter channel using two pairs of interdigitated activated comb-like electrode structures. All experiments are performed with conductivity adjusted medium samples. The electrode pairs were positioned divergent and convergent with respect to the flow. The AC signals used in the separation are 20 V peak-to-peak with frequencies of 10-50 kHz. The separation is based on balance of magnitude of the dielectrophoretic force and hydrodynamic force. The difference in response between circulating malignant cells and normal cells at a certain band of alternating current frequencies was used for rapid separation of cancer cells from blood. The significance of these experimental results is discussed in this paper, with detailed reporting on the suspension medium, preparation of cells, flow condition and the fabrication process of the microfluidic chip. The present technique could potentially be applied to identify incident cancer at a stage and size that is not yet detectable by standard diagnostic techniques (imaging and biochemical testing). Alternatively, it may also be used to detect cancer recurrences.

  11. Amphiphilic comb-like polymer for harvest of conductive nano-cellulose.

    PubMed

    Choi, Jaeyoo; Park, Subeom; Cheng, Jie; Park, Minsung; Hyun, Jinho

    2012-01-01

    In this study, electrically conductive bacterial cellulose (BC) was prepared by culturing Gluconacetobacter xylinus in a carbon nanotube (CNT)-dispersed medium. The CNTs were dispersed by adopting a non-covalent approach in the presence of non-ionic amphiphilic comb-like polymer (CLP). Specifically, the hydrophobic backbone of CLP was chemophysically attached to the surface of the CNTs and the hydrophilic side chains were released freely toward the medium in an aqueous environment. CLP-modified CNTs were stable and did not show any noticeable sediment, even after centrifugation at 15,000 rpm for 30 min. Notably, the dispersion solution of CLP-modified CNTs was stable at room temperature for several months because the long-range entropic repulsion among polymer-decorated tubes acted as a barrier to aggregation. The morphology of the BC membrane was studied by field-emission scanning electron microscopy. The presence of CLP bound to the CNT surface was characterized by Fourier transform infrared spectroscopy and the conductivity of the CNT-incorporated BC membrane was measured by four-probe measurements.

  12. Optical control of electron trapping: Generation of comb-like electron beams for tunable, pulsed, multi-color radiation sources

    NASA Astrophysics Data System (ADS)

    Kalmykov, Serge

    2014-10-01

    All-optical control over the electron phase space in laser-plasma accelerators enables production of ``designer'' electron beams that can be optimized for specific applications. GeV-scale acceleration with sub-100 TW (rather than PW) laser pulses, at repetition rates orders-of-magnitude higher than permitted by existing PW facilities, in a few-mm (rather than cm) length plasmas, requires maintaining an accelerating gradient as high as 10 GV/cm. This, in turn, dictates acceleration in the blowout regime in a dense plasma (~1019 cm-3). These highly dispersive plasmas rapidly transform the drive pulse into a relativistic optical shock, causing the plasma wake bucket (electron density bubble) to constantly expand, trapping background electrons, greatly degrading beam quality. We show that these effects can be overcome using a high-bandwidth driver (over 1/2 the carrier frequency) with a negative frequency chirp. Temporally advancing higher frequencies (thus compensating for the plasma-induced nonlinear frequency red-shift) and propagating the pulse in a plasma channel (to suppress diffraction of its leading edge) delays pulse self-steepening through electron dephasing and extends the dephasing length. As a result, continuous injection is suppressed and electron energy is boosted to the GeV level. In addition, periodic self-injection in the channel produces a sequence of femtosecond-length, quasi-monoenergetic bunches. The number of these spectral components, their charge, energy, and energy separation can be controlled by varying the channel radius and length, whereas accumulation of the noise (viz. continuously injected charge) is prevented by the negative chirp of the driver. This level of control is hard to achieve with conventional accelerator techniques. It is demonstrated that these clean, polychromatic, comb-like beams can drive high-brightness, tunable, multi-color gamma-ray sources. Work is supported by the US DOE Grant DE-SC0008382 and NSF Grant PHY-1104683.

  13. Memristor comprising film with comb-like structure of nanocolumns of metal oxide embedded in a metal oxide matrix

    DOEpatents

    Driscoll, Judith L; Lee, ShinBuhm; Jia, Quanxi

    2015-05-12

    Films having a comb-like structure of nanocolumns of Sm.sub.2O.sub.3 embedded in a SrTiO.sub.3 formed spontaneously on a substrate surface by pulsed laser deposition. In an embodiment, the nanocolumns had a width of about 20 nm with spaces between nanocolumns of about 10 nm. The films exhibited memristive behavior, and were extremely uniform and tunable. Oxygen deficiencies were located at vertical interfaces between the nanocolumns and the matrix. The substrates may be single-layered or multilayered.

  14. Effect of methyl groups on conformational properties of small ionized comb-like polyelectrolytes at the atomic level.

    PubMed

    Zhao, Hongxia; Liu, Jiaping; Ran, Qianping; Yang, Yong; Shu, Xin

    2017-03-01

    Comb-like polycarboxylate ether (PCE) molecules with different content of methyl groups substituted on backbone and different location of methyl groups substituted on the side chains, respectively, were designed and were studied in explicit salt solutions by all-atom molecular dynamics simulations. Methyl groups substituted on the backbone of PCE have a great effect on the conformation of PCE. Stiffness of charged backbone was not only affected by the rotational freedom but also the electrostatic repulsion between the charged COO(-) groups. The interaction of counterions (Na(+)) with COO(-) groups for PCE3 (with part of AA substituted by MAA on the backbone) was stronger and the screen effect was great, which decided the smaller size of PCE3. The interaction between water and COO(-) groups was strong regardless of the content of AA substituted by MAA on the backbone. The effect of methyl groups substituted on the different location of side chains on the conformation of PCE was less than that of methyl groups substituted on the backbone. The equilibrium sizes of the four PCE molecules with methyl groups substituted on the side chains were similar. Graphical Abstract Effect of methyl groups on conformational properties of small ionized comb-like polyelectrolytes at the atomic level.

  15. Molecular dynamics study of linear and comb-like polyelectrolytes in aqueous solution: effect of Ca2+ ions

    NASA Astrophysics Data System (ADS)

    Tong, Kefeng; Song, Xingfu; Sun, Shuying; Xu, Yanxia; Yu, Jianguo

    2014-08-01

    All-atom molecular dynamics simulations were employed to provide microscopic mechanism for the salt tolerance of polyelectrolytes dispersants. The conformational variation of polyelectrolytes and interactions between COO- groups and counterions/water molecules were also studied via radius of gyration and pair correlations functions. Sodium polyacrylate (NaPA) and sodium salts of poly(acrylic acid)-poly(ethylene oxide) (NaPA-PEO) were selected as the representative linear and comb-like polyelectrolyte, respectively. The results show that Ca2+ ions interact with COO- groups much stronger than Na+ ions and can bring ion-bridging interaction between intermolecular COO- groups in the NaPA systems. While in the NaPA-PEO systems, the introduced PEO side chains can prevent backbone chains from ion-bridging interactions and weaken the conformational changes. The present results can help in selecting and designing new-type efficient polyelectrolyte dispersants with good salt tolerance.

  16. A model of comb-like association with branches of arbitrary lengths: The mean statistical anisotropy of the polarizability tensor of liquid molecules

    NASA Astrophysics Data System (ADS)

    Durov, V. A.; Shilov, I. Yu.

    2008-01-01

    Analytic methods for calculating the mean anisotropy of the polarizability of liquid molecules consisting of chain aggregates of arbitrary lengths and branched comb-like aggregates with branches of arbitrary lengths were developed. The dependences of the mean anisotropy of the polarizability of methanol molecules on the thermodynamic parameters (equilibrium constants) of chain and branched aggregation and the structural characteristics of supramolecular aggregates were calculated. Special attention was paid to the influence of the degree of branching of comb-like aggregates on anisotropic light scattering. The calculation results were compared with the experimental data.

  17. Synergistic anti-tumor therapy by a comb-like multifunctional antibody nanoarray with exceptionally potent activity

    NASA Astrophysics Data System (ADS)

    Li, Huafei; Sun, Yun; Chen, Di; Zhao, He; Zhao, Mengxin; Zhu, Xiandi; Ke, Changhong; Zhang, Ge; Jiang, Cheng; Zhang, Li; Zhang, Fulei; Wei, Huafeng; Li, Wei

    2015-10-01

    Simultaneously blocking multiple mediators offers new hope for the treatment of complex diseases. However, the curative potential of current combination therapy by chronological administration of separate monoclonal antibodies (mAbs) or multi-specific mAbs is still moderate due to inconvenient manipulation, low cooperative effectors, poor pharmacokinetics and insufficient tumor accumulation. Here, we describe a facile strategy that arms distinct mAbs with cooperative effectors onto a long chain to form a multicomponent comb-like nano mAb. Unlike dissociative parental mAbs, the multifunctional mAb nanoarray (PL-RB) constructed from type I/II anti-CD20 mAbs shows good pharmacokinetics. This PL-RB simultaneously targets distinct epitopes on a single antigen (Ag) and neighboring Ags on different lymphocytes. This unique intra- and intercellular Ag cross-linking endows the multifunctional mAb nanoarray with potent apoptosis activity. The exceptional apoptosis, complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC) that are synchronously evoked by the nano PL-RB are further synergistically promoted via enhanced permeability and retention (EPR), which resulted in high intratumor accumulation and excellent anti-lymphoma efficiency.

  18. Controlled generation of comb-like electron beams in plasma channels for polychromatic inverse Thomson γ-ray sources

    NASA Astrophysics Data System (ADS)

    Kalmykov, S. Y.; Davoine, X.; Ghebregziabher, I.; Lehe, R.; Lifschitz, A. F.; Shadwick, B. A.

    2016-03-01

    Propagating a relativistically intense, negatively chirped laser pulse (the bandwidth  >150 nm) in a plasma channel makes it possible to generate background-free, comb-like electron beams—sequences of synchronized bunches with a low phase-space volume and controlled energy spacing. The tail of the pulse, confined in the accelerator cavity (an electron density ‘bubble’), experiences periodic focusing, while the head, which is the most intense portion of the pulse, steadily self-guides. Oscillations of the cavity size cause periodic injection of electrons from the ambient plasma, creating an electron energy comb with the number of components, their mean energy, and energy spacing dependent on the channel radius and pulse length. These customizable electron beams enable the design of a tunable, all-optical source of pulsed, polychromatic γ-rays using the mechanism of inverse Thomson scattering, with up to  ˜10-5 conversion efficiency from the drive pulse in the electron accelerator to the γ-ray beam. Such a source may radiate  ˜107 quasi-monochromatic photons per shot into a microsteradian-scale cone. The photon energy is distributed among several distinct bands, each having sub-30% energy spread, with a highest energy of 12.5 MeV.

  19. Membrane-Anchoring, Comb-Like Pseudopeptides for Efficient, pH-Mediated Membrane Destabilization and Intracellular Delivery.

    PubMed

    Chen, Siyuan; Wang, Shiqi; Kopytynski, Michal; Bachelet, Marie; Chen, Rongjun

    2017-03-08

    Endosomal release has been identified as a rate-limiting step for intracellular delivery of therapeutic agents, in particular macromolecular drugs. Herein, we report a series of synthetic pH-responsive, membrane-anchoring polymers exhibiting dramatic endosomolytic activity for efficient intracellular delivery. The comb-like pseudopeptidic polymers were synthesized by grafting different amounts of decylamine (NDA), which act as hydrophobic membrane anchors, onto the pendant carboxylic acid groups of a pseudopeptide, poly(l-lysine iso-phthalamide). The effects of the hydrophobic relatively long alkyl side chains on aqueous solution properties, cell membrane destabilization activity, and in-vitro cytotoxicity were investigated. The optimal polymer containing 18 mol % NDA exhibited limited hemolysis at pH 7.4 but induced nearly complete membrane destabilization at endosomal pH within only 20 min. The mechanistic investigation of membrane destabilization suggests the polymer-mediated pore formation. It has been demonstrated that the polymer with hydrophobic side chains displayed a considerable endosomolytic ability to release endocytosed materials into the cytoplasm of various cell lines, which is of critical importance for intracellular drug delivery applications.

  20. Multi-color γ-rays from comb-like electron beams driven by incoherent stacks of laser pulses

    NASA Astrophysics Data System (ADS)

    Kalmykov, S. Y.; Davoine, X.; Ghebregziabher, I.; Shadwick, B. A.

    2017-03-01

    Trains of fs-length, GeV-scale electron bunches with controlled energy spacing and a 5-D brightness up to 1017 A/m2 may be produced in a mm-scale uniform plasma. The main element of the scheme is an incoherent stack of 10-TW-scale laser pulses of different colors, with mismatched focal spots, with the highest-frequency pulse advanced in time. While driving an electron density bubble, this stack remains almost proof against nonlinear red-shift and self-compression. As a consequence, the unwanted continuous injection of background electrons is minimized. Weak focusing of the trailing (lower-frequency) component of the stack enforces expansions and contractions of the bubble, inducing controlled periodic injection. The resulting train of electron bunches maintains exceptional quality while being accelerated beyond the energy limits predicted by accepted scalings. Inverse Thomson scattering from this comb-like beam generates a sequence of quasi-monochromatic, fs-length γ-ray beams, an asset for nuclear forensics and pump-probe experiments in dense plasmas.

  1. The synthesis of multifunctional porous honey comb-like La2O3 thin film for supercapacitor and gas sensor applications.

    PubMed

    Yadav, A A; Lokhande, A C; Pujari, R B; Kim, J H; Lokhande, C D

    2016-12-15

    The porous honey comb-like La2O3 thin films have been synthesized using one step spray pyrolysis method. The influence of sprayed solution quantity on properties of La2O3 thin films is studied using X-ray diffraction, Fourier transform spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, optical absorption and Brunauer-Emmett-Teller techniques. Morphology of La2O3 electrode is controlled with sprayed solution quantity. The supercapacitive properties of La2O3 thin film electrode are investigated using cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance techniques. The La2O3 film electrode exhibited the specific capacitance of the 166Fg(-1) with 85% stability for the 3000 cycles. The La2O3 film electrode exhibited sensitivity of 68 at 523K for 500ppm CO2 gas concentration. The possible CO2 sensing mechanism is discussed.

  2. Accordion effect in a laser wakefield accelerator: Generating comb-like electron beams for a tunable pulsed source of polychromatic gamma-rays

    NASA Astrophysics Data System (ADS)

    Kalmykov, Serge; Davoine, Xavier; Ghebregziabher, Isaac; Shadwick, Bradley

    2016-10-01

    Trains of synchronized, fs-length GeV-scale electron bunches with a sub-micron normalized transverse emittance, brightness up to 1017 A/m2, and controlled energy spacing may be purposely produced in both plasma channels and uniform plasmas. A cavity of electron density, driven by an optimally designed multi-color stack of 10-TW-scale laser pulses, experiences expansions and contractions, periodically injecting electrons from the ambient dense plasma, accelerating them without compromising the beam quality. This periodic injection is naturally achieved in a plasma channel. The channel, however, is not a prerequisite to this effect. The number of comb components, as well as their charge and energy spacing, can be controlled in a uniform plasma by independently varying focal spots of the laser stack components. Inverse Thomson scattering from these comb-like beams produces synchronized sequences of quasi-monochromatic, fs-length gamma-ray flashes, which may become an asset to pump-probe experiments in dense plasmas. NSF Grant PHY-1535678.

  3. A comb-like branched β-D-glucan produced by a Cordyceps sinensis fungus and its protective effect against cyclophosphamide-induced immunosuppression in mice.

    PubMed

    Hu, Ting; Jiang, Chenbo; Huang, Qilin; Sun, Fengyuan

    2016-05-20

    An exopolysaccharide (EPS) was fractionated from fermentation media of a Cordyceps sinensis fungus (Cs-HK1) by ethanol precipitation at 2/5 volume ratio of ethanol/media. Its structural characteristics were elucidated by FT-IR, GC, GC-MS, 1D and 2D NMR combined with periodate oxidation, Smith degradation, partial acid hydrolysis, and methylation analysis. Furthermore, the immunomodulatory activity of EPS was evaluated by the model of cyclophosphamide-induced immunosuppression. The results from monosaccharide composition and partial acid hydrolysis indicated that EPS almost consisted of glucose excluding a trace amount of mannose. GC-MS and NMR analysis further confirmed EPS had a linear backbone of (1→3)-β-D-glucopyranosyl residues with a single (1→6)-β-D-glucopyranosyl side-branching unit for every three β-D-glucopyranosyl residues, showing a comb-like β-D-glucan with short and intensive branches, which was responsible for high viscosity. Moreover, EPS could significantly enhance immune organs and stimulate the release of major cytokines TNF-α and INF-γ, suggesting that EPS exhibited protective effect in immunocompromised mice.

  4. Dispersion of alumina suspension using comb-like and diblock copolymers produced by RAFT polymerization of AMPS and MPEG.

    PubMed

    Bouhamed, H; Boufi, S; Magnin, A

    2007-08-15

    Different copolymers of 2-acrylamido-2-methylpropanesulfonic acid sodium salt (AMPS) methoxypolyethyleneglycol methacrylate (MPEG) with statistical and diblock distributions were prepared using RAFT-controlled radical polymerization. The effect of polymer architecture and monomer ratio on the adsorption behavior, electrokinetic, and stability properties of the alumina suspensions was investigated. Adsorption isotherms showed that copolymer interaction depended on both the ratio of the monomers and their distribution within the macromolecular backbone. Changes in the electrokinetic properties of the alumina suspension after addition of the copolymers were investigated by monitoring the particle zeta-potential as a function of pH. A continuous shift in the isoelectric point IEP to a more acidic value was observed and particle charges were reversed when the amount of copolymer added exceeded a critical level.

  5. Comb-like amphiphilic copolymers bearing acetal-functionalized backbones with the ability of acid-triggered hydrophobic-to-hydrophilic transition as effective nanocarriers for intracellular release of curcumin.

    PubMed

    Zhao, Junqiang; Wang, Haiyang; Liu, Jinjian; Deng, Liandong; Liu, Jianfeng; Dong, Anjie; Zhang, Jianhua

    2013-11-11

    The pH-responsive micelles have enormous potential as nanosized drug carriers for cancer therapy due to their physicochemical changes in response to the tumor intracellular acidic microenvironment. Herein, a series of comb-like amphiphilic copolymers bearing acetal-functionalized backbone were developed based on poly[(2,4,6-trimethoxybenzylidene-1,1,1-tris(hydroxymethyl) ethane methacrylate-co-poly(ethylene glycol) methyl ether methacrylate] [P(TTMA-co-mPEGMA)] as effective nanocarriers for intracellular curcumin (CUR) release. P(TTMA-co-mPEGMA) copolymers with different hydrophobic-hydrophilic ratios were prepared by one-step reversible addition fragmentation chain transfer (RAFT) copolymerization of TTMA and mPEGMA. Their molecular structures and chemical compositions were confirmed by (1)H NMR, Fourier transform infrared spectroscopy (FT-IR) and gel permeation chromatography (GPC). P(TTMA-co-mPEGMA) copolymers could self-assemble into nanosized micelles in aqueous solution and displayed low critical micelle concentration (CMC). All P(TTMA-co-mPEGMA) micelles displayed excellent drug loading capacity, due to the strong π-π conjugate action and hydrophobic interaction between the PTTMA and CUR. Moreover, the hydrophobic PTTMA chain could be selectively hydrolyzed into a hydrophilic backbone in the mildly acidic environment, leading to significant swelling and final disassembly of the micelles. These morphological changes of P(TTMA-co-mPEGMA) micelles with time at pH 5.0 were determined by DLS and TEM. The in vitro CUR release from the micelles exhibited a pH-dependent behavior. The release rate of CUR was significantly accelerated at mildly acidic pH of 4.0 and 5.0 compared to that at pH 7.4. Toxicity test revealed that the P(TTMA-co-mPEGMA) copolymers exhibited low cytotoxicity, whereas the CUR-loaded micelles maintained high cytotoxicity for HepG-2 and EC-109 cells. The results indicated that the novel P(TTMA-co-mPEGMA) micelles with low CMC, small and tunable

  6. Concentration Addition, Independent Action and Generalized Concentration Addition Models for Mixture Effect Prediction of Sex Hormone Synthesis In Vitro

    PubMed Central

    Hadrup, Niels; Taxvig, Camilla; Pedersen, Mikael; Nellemann, Christine; Hass, Ulla; Vinggaard, Anne Marie

    2013-01-01

    Humans are concomitantly exposed to numerous chemicals. An infinite number of combinations and doses thereof can be imagined. For toxicological risk assessment the mathematical prediction of mixture effects, using knowledge on single chemicals, is therefore desirable. We investigated pros and cons of the concentration addition (CA), independent action (IA) and generalized concentration addition (GCA) models. First we measured effects of single chemicals and mixtures thereof on steroid synthesis in H295R cells. Then single chemical data were applied to the models; predictions of mixture effects were calculated and compared to the experimental mixture data. Mixture 1 contained environmental chemicals adjusted in ratio according to human exposure levels. Mixture 2 was a potency adjusted mixture containing five pesticides. Prediction of testosterone effects coincided with the experimental Mixture 1 data. In contrast, antagonism was observed for effects of Mixture 2 on this hormone. The mixtures contained chemicals exerting only limited maximal effects. This hampered prediction by the CA and IA models, whereas the GCA model could be used to predict a full dose response curve. Regarding effects on progesterone and estradiol, some chemicals were having stimulatory effects whereas others had inhibitory effects. The three models were not applicable in this situation and no predictions could be performed. Finally, the expected contributions of single chemicals to the mixture effects were calculated. Prochloraz was the predominant but not sole driver of the mixtures, suggesting that one chemical alone was not responsible for the mixture effects. In conclusion, the GCA model seemed to be superior to the CA and IA models for the prediction of testosterone effects. A situation with chemicals exerting opposing effects, for which the models could not be applied, was identified. In addition, the data indicate that in non-potency adjusted mixtures the effects cannot always be

  7. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  8. Autosomal and X-Linked Additive Genetic Variation for Lifespan and Aging: Comparisons Within and Between the Sexes in Drosophila melanogaster.

    PubMed

    Griffin, Robert M; Schielzeth, Holger; Friberg, Urban

    2016-12-07

    Theory makes several predictions concerning differences in genetic variation between the X chromosome and the autosomes due to male X hemizygosity. The X chromosome should: (i) typically show relatively less standing genetic variation than the autosomes, (ii) exhibit more variation in males compared to females because of dosage compensation, and (iii) potentially be enriched with sex-specific genetic variation. Here, we address each of these predictions for lifespan and aging in Drosophila melanogaster To achieve unbiased estimates of X and autosomal additive genetic variance, we use 80 chromosome substitution lines; 40 for the X chromosome and 40 combining the two major autosomes, which we assay for sex-specific and cross-sex genetic (co)variation. We find significant X and autosomal additive genetic variance for both traits in both sexes (with reservation for X-linked variation of aging in females), but no conclusive evidence for depletion of X-linked variation (measured through females). Males display more X-linked variation for lifespan than females, but it is unclear if this is due to dosage compensation since also autosomal variation is larger in males. Finally, our results suggest that the X chromosome is enriched for sex-specific genetic variation in lifespan but results were less conclusive for aging overall. Collectively, these results suggest that the X chromosome has reduced capacity to respond to sexually concordant selection on lifespan from standing genetic variation, while its ability to respond to sexually antagonistic selection may be augmented.

  9. Autosomal and X-Linked Additive Genetic Variation for Lifespan and Aging: Comparisons Within and Between the Sexes in Drosophila melanogaster

    PubMed Central

    Griffin, Robert M.; Schielzeth, Holger; Friberg, Urban

    2016-01-01

    Theory makes several predictions concerning differences in genetic variation between the X chromosome and the autosomes due to male X hemizygosity. The X chromosome should: (i) typically show relatively less standing genetic variation than the autosomes, (ii) exhibit more variation in males compared to females because of dosage compensation, and (iii) potentially be enriched with sex-specific genetic variation. Here, we address each of these predictions for lifespan and aging in Drosophila melanogaster. To achieve unbiased estimates of X and autosomal additive genetic variance, we use 80 chromosome substitution lines; 40 for the X chromosome and 40 combining the two major autosomes, which we assay for sex-specific and cross-sex genetic (co)variation. We find significant X and autosomal additive genetic variance for both traits in both sexes (with reservation for X-linked variation of aging in females), but no conclusive evidence for depletion of X-linked variation (measured through females). Males display more X-linked variation for lifespan than females, but it is unclear if this is due to dosage compensation since also autosomal variation is larger in males. Finally, our results suggest that the X chromosome is enriched for sex-specific genetic variation in lifespan but results were less conclusive for aging overall. Collectively, these results suggest that the X chromosome has reduced capacity to respond to sexually concordant selection on lifespan from standing genetic variation, while its ability to respond to sexually antagonistic selection may be augmented. PMID:27678519

  10. The Codevelopment of Skill at and Preference for Use of Retrieval-Based Processes for Solving Addition Problems: Individual and Sex Differences from First to Sixth Grades

    ERIC Educational Resources Information Center

    Bailey, Drew H.; Littlefield, Andrew; Geary, David C.

    2012-01-01

    The ability to retrieve basic arithmetic facts from long-term memory contributes to individual and perhaps sex differences in mathematics achievement. The current study tracked the codevelopment of preference for using retrieval over other strategies to solve single-digit addition problems, independent of accuracy, and skilled use of retrieval…

  11. Perinatal BPA exposure alters body weight and composition in a dose specific and sex specific manner: The addition of peripubertal exposure exacerbates adverse effects in female mice.

    PubMed

    Rubin, Beverly S; Paranjpe, Maneesha; DaFonte, Tracey; Schaeberle, Cheryl; Soto, Ana M; Obin, Martin; Greenberg, Andrew S

    2017-03-01

    Body weight (BW) and body composition were examined in CD-1 mice exposed perinatally or perinatally and peripubertally to 0, 0.25, 2.5, 25, or 250μg BPA/kg BW/day. Our goal was to identify the BPA dose (s) and the exposure window(s) that increased BW and adiposity, and to assess potential sex differences in this response. Both perinatal exposure alone and perinatal plus peripubertal exposure to environmentally relevant levels of BPA resulted in lasting effects on body weight and body composition. The effects were dose specific and sex specific and were influenced by the precise window of BPA exposure. The addition of peripubertal BPA exposure following the initial perinatal exposure exacerbated adverse effects in the females but appeared to reduce differences in body weight and body composition between control and BPA exposed males. Some effects of BPA on body weight and body composition showed a non-linear dose response.

  12. The codevelopment of skill at and preference for use of retrieval-based processes for solving addition problems: individual and sex differences from first to sixth grades.

    PubMed

    Bailey, Drew H; Littlefield, Andrew; Geary, David C

    2012-09-01

    The ability to retrieve basic arithmetic facts from long-term memory contributes to individual and perhaps sex differences in mathematics achievement. The current study tracked the codevelopment of preference for using retrieval over other strategies to solve single-digit addition problems, independent of accuracy, and skilled use of retrieval (i.e., accuracy and reaction time [RT]) from first to sixth grades inclusive (N=311). Accurate retrieval in first grade was related to working memory capacity and intelligence, and it predicted a preference for retrieval in second grade. In later grades, the relation between skill and preference changed such that preference in one grade predicted accuracy and RT in the next grade as RT and accuracy continued to predict future gains in preference. In comparison with girls, boys had a consistent preference for retrieval over other strategies and had faster retrieval speeds, but the sex difference in retrieval accuracy varied across grades. Results indicate that ability influences early skilled retrieval, but both practice and skill influence each other in a feedback loop later in development and provide insights into the source of the sex difference in problem-solving approaches.

  13. Predictors of victim disclosure in child sexual abuse: Additional evidence from a sample of incarcerated adult sex offenders.

    PubMed

    Leclerc, Benoit; Wortley, Richard

    2015-05-01

    The under-reporting of child sexual abuse by victims is a serious problem that may prolong the suffering of victims and leave perpetrators free to continue offending. Yet empirical evidence indicates that victim disclosure rates are low. In this study, we perform regression analysis with a sample of 369 adult child sexual offenders to examine potential predictors of victim disclosure. Specifically, we extend the range of previously examined potential predictors of victim disclosure and investigate interaction effects in order to better capture under which circumstances victim disclosure is more likely. The current study differs from previous studies in that it examines the impact of victim and offense variables on victim disclosure from the perspective of the offender. In line with previous studies, we found that disclosure increased with the age of the victim and if penetration had occurred. In addition, we found that disclosure increased when the victim came from a non-dysfunctional family and resisted the abuse. The presence of an interaction effect highlighted the impact of the situation on victim disclosure. This effect indicated that as victims get older, they are more likely to disclose the abuse when they are not living with the offender at the time of abuse, but less likely to do so when they are living with the offender at the time of abuse. These findings are discussed in relation to previous studies and the need to facilitate victim disclosure.

  14. Additive sex-specific influence of common non-synonymous DISC1 variants on amygdala, basal ganglia, and white cortical surface area in healthy young adults.

    PubMed

    Mühle, Christiane; Kreczi, Jakob; Rhein, Cosima; Richter-Schmidinger, Tanja; Alexopoulos, Panagiotis; Doerfler, Arnd; Lenz, Bernd; Kornhuber, Johannes

    2017-03-01

    The disrupted-in-schizophrenia-1 (DISC1) gene is known for its role in the development of mental disorders. It is also involved in neurodevelopment, cognition, and memory. To investigate the association between DISC1 variants and brain morphology, we analyzed the influence of the three common non-synonymous polymorphisms in DISC1 on specific brain structures in healthy young adults. The volumes of brain regions were determined in 145 subjects by magnetic resonance imaging and automated analysis using FreeSurfer. Genotyping was performed by high resolution melting of amplified products. In an additive genetic model, rs6675281 (Leu607Phe), rs3738401 (Arg264Gln), and rs821616 (Ser704Cys) significantly explained the volume variance of the amygdala (p = 0.007) and the pallidum (p = 0.004). A higher cumulative portion of minor alleles was associated with larger volumes of the amygdala (p = 0.005), the pallidum (p = 0.001), the caudate (p = 0.024), and the putamen (p = 0.007). Sex-stratified analysis revealed a strong genetic effect of rs6675281 on putamen and pallidum in females but not in males and an opposite influence of rs3738401 on the white cortical surface in females compared to males. The strongest single association was found for rs821616 and the amygdala volume in male subjects (p < 0.001). No effect was detected for the nucleus accumbens. We report-to our knowledge-for the first time a significant and sex-specific influence of common DISC1 variants on volumes of the basal ganglia, the amygdala and on the cortical surface area. Our results demonstrate that the additive model of all three polymorphisms outperforms their single analysis.

  15. The additionally glycosylated variant of human sex hormone-binding globulin (SHBG) is linked to estrogen-dependence of breast cancer.

    PubMed

    Becchis, M; Frairia, R; Ferrera, P; Fazzari, A; Ondei, S; Alfarano, A; Coluccia, C; Biglia, N; Sismondi, P; Fortunati, N

    1999-03-01

    Sex Hormone-Binding Globulin (SHBG), the plasma carrier for androgens and estradiol, inhibits the estradiol-induced proliferation of breast cancer cells through its membrane receptor, cAMP, and PKA. In addition, the SHBG membrane receptor is preferentially expressed in estrogen-dependent (ER+/PR+) breast cancers which are also characterized by a lower proliferative rate than tumors negative for the SHBG receptor. A variant SHBG with a point mutation in exon 8, causing an aminoacid substitution (Asp 327-->Asn) and thus, the introduction of an additional N-glycosylation site, has been reported. In this work, the distribution of the SHBG variant was studied in 255 breast cancer patients, 32 benign mammary disease patients, and 120 healthy women. The presence of the SHBG mutation was evaluated with PCR amplification of SHBG exon 8 and Hinf I restriction fragment length polymorphism (RFLP) procedure. This technique allowed us to identify 54 SHBG variants (53 W/v and 1 v/v) in breast cancer patients (21.2%), 5 variants (4 W/v and 1 v/v) in benign mammary disease patients (15.6%), and 14 variants (W/v) in the control group (11.6%). The results of PCR and RFLP were confirmed both by nucleotide sequence of SHBG exon 8 and western blot of the plasma SHBG. No differences in the mean plasma level of the protein were observed in the three populations. The frequency of the SHBG variant was significantly higher in ER+/PR+ tumors and in tumors diagnosed in patients over 50 years of age than in the control group. This observation suggests the existence of a close link between the estrogen-dependence of breast cancer and the additionally glycosylated SHBG, further supporting a critical role of the protein in the neoplasm.

  16. Clinically insignificant improvement of prostate cancer prediction by addition of sex steroid hormones and SHBG serum levels to serum PSA, fPSA%, and age in a screening setting.

    PubMed

    Heidegger, Isabel; Popovscaia, Marina; Ramoner, Reinhold; Schäfer, Georg; Stenzel, Birgit; Bektic, Jasmin; Horninger, Wolfgang; Klocker, Helmut

    2012-10-01

    Abstract Various findings implicate sex hormones in prostate growth and development and also in prostate carcinogenesis. We investigated if addition of sex steroid hormone and sex hormone binding globulin (SHBG) serum levels to standard risk assessment parameters [prostate-specific antigen (PSA), free PSA percentage (fPSA%), and age] improves prostate cancer prediction in a PSA screening setting. Steroid hormones testosterone (T), free testosterone (fT), and estradiol (E2), and binding protein SHBG levels were measured in 762 men undergoing prostate biopsy due to suspect PSA serum levels. Prostate cancer was diagnosed in 286 (37.5%) of these men. Our data confirmed that PSA (mean BE=5.09; mean CA=6.05; p=1.24×10-5), fPSA% (mean BE=22.08; mean CA=18.67; p=1.97×10-7), and age (mean BE=60.64; mean CA=64.5; p=7.05×10-10) differentiate men with cancer (CA) and men with benign disease (BE), such as benign prostate hyperplasia. In addition, SHBG (mean BE=50.3; mean CA=54.9; p=0.008) also differed statistically significantly between these two groups. All hormones except E2 and tumor markers correlated significantly with age (T: ρ=-0.09; fT: ρ=-0.27; SHBG: ρ=0.21; PSA: ρ=0.32; and fPSA%: ρ=0.22). Furthermore, we found that PSA correlates with E2 (ρ=0.08), and fPSA% with SHBG (ρ=0.1) and fT (ρ=-0.09). Addition of hormones and SHBG to a baseline marker model including PSA, fPSA%, and age improved cancer prediction in three multivariate classification methods; however, the improvement was minimal. The best improvement by 0.8% was obtained in the logistic regression model with the addition of T and SHBG or of E2 and SHBG, or in the support vector machine model with the addition of SHBG and all steroid hormones to the combination of standard markers PSA, fPSA%, and age; however, this additional gain of accuracy is too small to justify the additional efforts and costs.

  17. Sex Headaches

    MedlinePlus

    ... role during sex also may help. References Cutrer FM, et al. Cough, exercise, and sex headaches. Neurology ... aspx?resourceID=4. Accessed Jan. 19, 2015. Cutrer FM. Primary headache associated with sexual activity. http://www. ...

  18. Sex Therapy

    MedlinePlus

    ... effective for individuals of any age, sex or sexual orientation. Sex therapy is usually provided by psychologists, social workers, physicians or licensed therapists who have special training in issues related to sex ... do not have sexual contact with clients, in the office or anywhere ...

  19. How to sell safer sex.

    PubMed

    Overs, C

    1991-09-01

    Social and economic factors determine the extent of the sex industry in societies. Despite AIDS, the sex industry will continue to thrive. Accordingly, health promotion strategies aimed at sex workers and their clients should not stem from the belief that the industry should cease to exist. This paper offers advice in developing and implementing programs to promote safer sex among sex workers. The social context is 1 element to consider in planning successful campaigns. Interventions must be combined with well-planned prevention campaigns aimed at entire populations. The opinions and participation of those involved in the industry should also be sought, while worker discussion and action upon other community issues should not be discouraged. Care should be given to target the numerous and diverse sex worker audiences in addition to other persons related to and involved in the industry. Programs should address the main obstacles to practicing safer sex, and attention should be given to ensure the provision of an adequate and regular supply of cheap or free condoms through varied distribution channels. In the area of service provision, sex workers need easy access to social support and health care services from which they are often excluded. Activities conducted around the world include the marketing of safer sex, distributing printed information on HIV and AIDS to clients, training sex workers to pass designated constructive ideas to others involved in the sex industry, referring sex workers to sex businesses supportive of safer sex practices, and developing street theater and cabaret shows in bars.

  20. Sex Offenders.

    ERIC Educational Resources Information Center

    Hayes, Susan

    1991-01-01

    This paper on the problem of sex offending among individuals with intellectual disabilities examines the incidence of this problem, characteristics of intellectually disabled sex offenders, determination of whether the behavior is a paraphilia or functional age-related behavior, and treatment options, with emphasis on the situation in New South…

  1. Sex education in Portugal.

    PubMed

    Frade, A; Vilar, D

    1991-05-01

    The article on sex education in Portugal covers background, the educational system, the clashes of the 1960's over sex education, the Committee for the Study of Sexuality and Education (CSSE), the policies, politics and social movements during the period 1974 - 1984, the discussions in Parliament, the 1988 Reform of the Educational System, the Family Planning Association (FPA) and sex education, and the future role of the FPA. It was not until the institution of the multiparity parliamentary system in 1974 that discussing social and political changes was possible, culminating in 1984 with new legislation on abortion, family planning, and sex education. School reform came in 1987/8 with the Ministry of Education primarily responsible for curricula. The 1960's brought with it the influence of the Catholic Church. Change came in the form of progressivism among Catholics who replaced dogma with dialogue and listening. Sex education was considered as preparation for marriage, but masturbation, contraception, and prostitution were also discussed. In addition, the founder of FPA chaired the CSSE in 1971 and opened up debate on sex issues and drafted a bill to establish co-education in Portuguese schools. The revolution of 1974 brought an end to censorship and brought forth a policy of developing family planning. Changed in the Family Code gave women greater equality. UNFPA supported teacher training in non-sexist education. With human reproduction included in the natural sciences, there was still no school sex education policy and contraception was only sometimes represented in the biology curriculum. The focus of FPA was on contraception and abortion. Finally in the 1980's, the first sex education programs were developed for out-of-school youth. Even though in the 1970's there were leftists groups promoting sex education, it took leftist parliamentary power to get legislation on sex education in the schools adopted. The Ministry of Education however was pressured by the

  2. Pre-Exposure Prophylaxis (PrEP) as an Additional Tool for HIV Prevention Among Men Who Have Sex With Men in Belgium: The Be-PrEP-ared Study Protocol

    PubMed Central

    Nöstlinger, Christiana; Wouters, Kristien; Fransen, Katrien; Crucitti, Tania; Kenyon, Chris; Buyze, Jozefien; Schurmans, Céline; Laga, Marie; Vuylsteke, Bea

    2017-01-01

    Background Pre-exposure prophylaxis (PrEP) is a promising and effective tool to prevent HIV. With the approval of Truvada as daily PrEP by the European Commission in August 2016, individual European Member states prepare themselves for PrEP implementation following the examples of France and Norway. However, context-specific data to guide optimal implementation is currently lacking. Objective With this demonstration project we evaluate whether daily and event-driven PrEP, provided within a comprehensive prevention package, is a feasible and acceptable additional prevention tool for men who have sex with men (MSM) at high risk of acquiring HIV in Belgium. The study’s primary objective is to document the uptake, acceptability, and adherence to both daily and event-driven PrEP, while several secondary objectives have been formulated including impact of PrEP use on sexual behavior. Methods The Be-PrEP-ared study is a phase 3, single-site, open-label prospective cohort study with a large social science component embedded in the trial. A total of 200 participants choose between daily or event-driven PrEP use and may switch, discontinue, or restart their regimen at the 3-monthly visits for a duration of 18 months. Data are collected on several platforms: an electronic case report form, a Web-based tool where participants register their sexual behavior and pill use, a more detailed electronic self-administered questionnaire completed during study visits on a tablet computer, and in-depth interviews among a selected sample of participants. To answer the primary objective, the recruitment rate, (un)safe sex behavior during the last 6 months, percentage of reported intention to use PrEP in the future, retention rates in different regimens, and attitudes towards PrEP use will be analyzed. Adherence will be monitored using self-reported adherence, pill count, tenofovir drug levels in blood samples, and the perceived skills to adhere. Results All participants are currently

  3. Sex work and sex trafficking.

    PubMed

    Ditmore, M; Saunders, P

    1998-01-01

    Preventing HIV infection and other sexually transmitted diseases (STDs), as well as sexual and physical violence, are major occupational health and safety concerns for prostitutes. Considerable evidence shows that anti-prostitution laws facilitate violence and abuse against prostitutes and may increase their risk of contracting HIV/STDs. For example, police often take advantage of existing laws against prostitution to demand money or sex. In general, the strict enforcement of anti-prostitution laws marginalizes prostitutes from services which could help them avoid abuse and promotes an environment in which prostitutes must take risks to avoid detection and arrest. One strategy to improve prostitutes' lives would therefore be to remove laws which prevent them from working safely and from travelling abroad to work legally. Projects in which prostitutes are actively involved have helped break down stereotypes against prostitutes, while police-sex worker liaison projects in Scotland and Australia have led to higher levels of reporting of crimes against prostitutes. The Network of Sex Work Projects (NSWP), an organization which links sex worker health programs around the world, has found that the incidence of HIV/STDs among prostitutes is lowest when they have control over their work conditions; access to condoms, lubricants, and other safe sex materials; and respect of their basic human and legal rights. People need to understand that consensual involvement in sex work is different from forced sex trafficking.

  4. Adaptive value of sex in microbial pathogens.

    PubMed

    Michod, Richard E; Bernstein, Harris; Nedelcu, Aurora M

    2008-05-01

    Explaining the adaptive value of sex is one of the great outstanding problems in biology. The challenge comes from the difficulty in identifying the benefits provided by sex, which must outweigh the substantial costs of sex. Here, we consider the adaptive value of sex in viruses, bacteria and fungi, and particularly the information available on the adaptive role of sex in pathogenic microorganisms. Our general theme is that the varied aspects of sex in pathogens illustrate the varied issues surrounding the evolution of sex generally. These include, the benefits of sex (in the short- and long-term), as well as the costs of sex (both to the host and to the pathogen). For the benefits of sex (that is, its adaptive value), we consider three hypotheses: (i) sex provides for effective and efficient recombinational repair of DNA damages, (ii) sex provides DNA for food, and (iii) sex produces variation and reduces genetic associations among alleles under selection. Although the evolution of sex in microbial pathogens illustrates these general issues, our paper is not a general review of theories for the evolution of sex in all organisms. Rather, we focus on the adaptive value of sex in microbial pathogens and conclude that in terms of short-term benefits, the DNA repair hypothesis has the most support and is the most generally applicable hypothesis in this group. In particular, recombinational repair of DNA damages may substantially benefit pathogens when challenged by the oxidative defenses of the host. However, in the long-term, sex may help get rid of mutations, increase the rate of adaptation of the population, and, in pathogens, may infrequently create new infective strains. An additional general issue about sex illustrated by pathogens is that some of the most interesting consequences of sex are not necessarily the reasons for which sex evolved. For example, antibiotic resistance may be transferred by bacterial sex, but this transfer is probably not the reason sex

  5. Moral Pluralism and Sex Education

    ERIC Educational Resources Information Center

    Corngold, Josh

    2013-01-01

    How should common schools in a liberal pluralist society approach sex education in the face of deep disagreement about sexual morality? Should they eschew sex education altogether? Should they narrow its focus to facts about biology, reproduction, and disease prevention? Should they, in addition to providing a broad palette of information about…

  6. American Cockroach Sex Attractant.

    PubMed

    Jacobson, M; Beroza, M

    1965-02-12

    The structure (2,2-dimethyl-3-isopropylidenecyclopropyl propionate) previously assigned to the sex attractant of the American cockroach has now been shown by additional physical and chemical data and biological inactivity of the synthetic preparation to be incorrect. The structure of this attractant remains to be determined.

  7. Sex Education.

    ERIC Educational Resources Information Center

    Williams, Sue

    1991-01-01

    This discussion of sex education for individuals with intellectual disabilities outlines Delys Sergeant's "coat hanger theory," which involves three coats or phases of sexuality: a physiological stimulus response coat; a reproductive coat; and a coat of attitudes, values, and self-esteem. Influences acting on individuals' sexuality include family,…

  8. Conflict over condition-dependent sex allocation can lead to mixed sex-determination systems.

    PubMed

    Kuijper, Bram; Pen, Ido

    2014-11-01

    Theory suggests that genetic conflicts drive turnovers between sex-determining mechanisms, yet these studies only apply to cases where sex allocation is independent of environment or condition. Here, we model parent-offspring conflict in the presence of condition-dependent sex allocation, where the environment has sex-specific fitness consequences. Additionally, one sex is assumed to be more costly to produce than the other, which leads offspring to favor a sex ratio less biased toward the cheaper sex in comparison to the sex ratio favored by mothers. The scope for parent-offspring conflict depends on the relative frequency of both environments: when one environment is less common than the other, parent-offspring conflict can be reduced or even entirely absent, despite a biased population sex ratio. The model shows that conflict-driven invasions of condition-independent sex factors (e.g., sex chromosomes) result either in the loss of condition-dependent sex allocation, or, interestingly, lead to stable mixtures of condition-dependent and condition-independent sex factors. The latter outcome corresponds to empirical observations in which sex chromosomes are present in organisms with environment-dependent sex determination. Finally, conflict can also favor errors in environmental perception, potentially resulting in the loss of condition-dependent sex allocation without genetic changes to sex-determining loci.

  9. Balance of the Sexes: Addressing Sex Differences in Preclinical Research

    PubMed Central

    Zakiniaeiz, Yasmin; Cosgrove, Kelly P.; Potenza, Marc N.; Mazure, Carolyn M.

    2016-01-01

    Preclinical research is fundamental for the advancement of biomedical sciences and enhancing healthcare. Considering sex differences in all studies throughout the entire biomedical research pipeline is necessary to adequately inform clinical research and improve health outcomes. However, there is a paucity of information to date on sex differences in preclinical work. As of 2009, most (about 80 percent) rodent studies across 10 fields of biology were still conducted with only male animals. In 2016, the National Institutes of Health implemented a policy aimed to address this concern by requiring the consideration of sex as a biological variable in preclinical research grant applications. This perspective piece aims to (1) provide a brief history of female inclusion in biomedical research, (2) describe the importance of studying sex differences, (3) explain possible reasons for opposition of female inclusion, and (4) present potential additional solutions to reduce sex bias in preclinical research. PMID:27354851

  10. Balance of the Sexes: Addressing Sex Differences in Preclinical Research.

    PubMed

    Zakiniaeiz, Yasmin; Cosgrove, Kelly P; Potenza, Marc N; Mazure, Carolyn M

    2016-06-01

    Preclinical research is fundamental for the advancement of biomedical sciences and enhancing healthcare. Considering sex differences in all studies throughout the entire biomedical research pipeline is necessary to adequately inform clinical research and improve health outcomes. However, there is a paucity of information to date on sex differences in preclinical work. As of 2009, most (about 80 percent) rodent studies across 10 fields of biology were still conducted with only male animals. In 2016, the National Institutes of Health implemented a policy aimed to address this concern by requiring the consideration of sex as a biological variable in preclinical research grant applications. This perspective piece aims to (1) provide a brief history of female inclusion in biomedical research, (2) describe the importance of studying sex differences, (3) explain possible reasons for opposition of female inclusion, and (4) present potential additional solutions to reduce sex bias in preclinical research.

  11. When Sex Is Painful

    MedlinePlus

    ... AQ FREQUENTLY ASKED QUESTIONS GYNECOLOGIC PROBLEMS FAQ020 When Sex Is Painful • How common is painful sex? • What causes pain during sex? • Where is pain during sex felt? • When should ...

  12. Sex during Pregnancy

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Sex During Pregnancy KidsHealth > For Parents > Sex During Pregnancy ... satisfying and safe sexual relationship during pregnancy. Is Sex During Pregnancy Safe? Sex is considered safe during ...

  13. Sex work among men who have sex with men and transgender women in Bogotá.

    PubMed

    Bianchi, Fernanda T; Reisen, Carol A; Zea, Maria Cecilia; Vidal-Ortiz, Salvador; Gonzales, Felisa A; Betancourt, Fabián; Aguilar, Marcela; Poppen, Paul J

    2014-11-01

    This qualitative study examined sex work among internally displaced male and transgender female sex workers in Bogotá, Colombia. Internal displacement has occurred in Colombia as a result of decades of conflict among armed groups and has created large-scale migration from rural to urban areas. Informed by the polymorphous model of sex work, which posits that contextual conditions shape the experience of sex work, we examined three main research questions. The first dealt with how internal displacement was related to the initiation of sex work; the second concerned the effect of agency on sex worker satisfaction; and the third examined how sex work in this context was related to HIV and other risks. Life history interviews were conducted with 26 displaced individuals who had done sex work: 14 were men who have sex with men and 12 were transgender women (natal males). Findings revealed that many participants began doing sex work in the period immediately after displacement, because of a lack of money, housing, and social support. HIV risk was greater during this time due to limited knowledge of HIV and inexperience negotiating safer sex with clients. Other findings indicated that sex workers who exerted more control and choice in the circumstances of their work reported greater satisfaction. In addition, we found that although many sex workers insisted on condom use with clients, several noted that they would sometimes have unprotected sex for additional money. Specific characteristics affecting the experience of sex work among the transgender women were also discussed.

  14. Sex determination in Chlamydomonas.

    PubMed

    Goodenough, Ursula; Lin, Huawen; Lee, Jae-Hyeok

    2007-06-01

    The sex-determination system of the unicellular green alga, Chlamydomonas reinhardtii, is governed by genes in the mating-type (MT) locus and entails additional genes located in autosomes. Gene expression is initiated by nitrogen starvation, and cells differentiate into plus or minus gametes within 6h. Reviewed is our current understanding of gametic differentiation and fertilization, initiation of zygote development, and the uniparental inheritance of organelle genomes.

  15. Sex reduces genetic variation: a multidisciplinary review.

    PubMed

    Gorelick, Root; Heng, Henry H Q

    2011-04-01

    For over a century, the paradigm has been that sex invariably increases genetic variation, despite many renowned biologists asserting that sex decreases most genetic variation. Sex is usually perceived as the source of additive genetic variance that drives eukaryotic evolution vis-à-vis adaptation and Fisher's fundamental theorem. However, evidence for sex decreasing genetic variation appears in ecology, paleontology, population genetics, and cancer biology. The common thread among many of these disciplines is that sex acts like a coarse filter, weeding out major changes, such as chromosomal rearrangements (that are almost always deleterious), but letting minor variation, such as changes at the nucleotide or gene level (that are often neutral), flow through the sexual sieve. Sex acts as a constraint on genomic and epigenetic variation, thereby limiting adaptive evolution. The diverse reasons for sex reducing genetic variation (especially at the genome level) and slowing down evolution may provide a sufficient benefit to offset the famed costs of sex.

  16. Genomics of sex determination.

    PubMed

    Zhang, Jisen; Boualem, Adnane; Bendahmane, Abdelhafid; Ming, Ray

    2014-04-01

    Sex determination is a major switch in the evolutionary history of angiosperm, resulting 11% monoecious and dioecious species. The genomic sequences of papaya sex chromosomes unveiled the molecular basis of recombination suppression in the sex determination region, and candidate genes for sex determination. Identification and analyses of sex determination genes in cucurbits and maize demonstrated conservation of sex determination mechanism in one lineage and divergence between the two systems. Epigenetic control and hormonal influence of sex determination were elucidated in both plants and animals. Intensive investigation of potential sex determination genes in model species will improve our understanding of sex determination gene network. Such network will in turn accelerate the identification of sex determination genes in dioecious species with sex chromosomes, which are burdensome due to no recombination in sex determining regions. The sex determination genes in dioecious species are crucial for understanding the origin of dioecy and sex chromosomes, particularly in their early stage of evolution.

  17. Sex Bias in Children.

    ERIC Educational Resources Information Center

    Zalk, Sue Rosenberg; And Others

    This study investigated children's sex biased attitudes as a function of the sex, age, and race of the child as well as a geographical-SES factor. Two attitudes were measured on a 55-item questionnaire: Sex Pride (attributing positive characteristics to a child of the same sex) and Sex Prejudice (attributing negative characteristics to a child of…

  18. [Sex and gender differences in pharmacotherapy].

    PubMed

    Regitz-Zagrosek, V

    2014-09-01

    Many drugs have act differently in women and men. Biological differences between women and men lead to sex differences in pharmacokinetics, i.e., in drug absorption, distribution in tissues, metabolism by liver enzymes, and excretion via the kidney and intestine. In addition there are sex differences in pharmacodynamics, leading to a different efficacy of drugs in women and men. The biological differences between women and men may be caused by sex-specific gene expression, by sex-specific epigenetic modifications, and finally by the effect of sex hormones. In addition, gender plays a role in drug efficacy as a sociocultural dimension that may lead to differences between women and men. Frequently drugs are only tested on animals of one sex and thereby optimized for one sex. This is based on the notion that sex differences are not important for clinical drug effects. Furthermore, to date, sex and gender differences have been underestimated in clinical studies, and phase III studies were not prospectively designed to assess sex differences in drug effects. In addition, women and men use drugs differently with respect to compliance, adherence, and self-medication with over-the-counter drugs. Further, it is known that male and female physicians treat women and men as patients differently. In conclusion, drug therapy is not yet optimized for both genders. However, there is increasing awareness that differences between women and men should be respected in order to provide optimal drugs in optimal doses for both genders.

  19. Conflict on the sex chromosomes: cause, effect, and complexity.

    PubMed

    Mank, Judith E; Hosken, David J; Wedell, Nina

    2014-10-03

    Intralocus sexual conflict and intragenomic conflict both affect sex chromosome evolution and can in extreme cases even cause the complete turnover of sex chromosomes. Additionally, established sex chromosomes often become the focus of heightened conflict. This creates a tangled relationship between sex chromosomes and conflict with respect to cause and effect. To further complicate matters, sexual and intragenomic conflict may exacerbate one another and thereby further fuel sex chromosome change. Different magnitudes and foci of conflict offer potential explanations for lineage-specific variation in sex chromosome evolution and answer long-standing questions as to why some sex chromosomes are remarkably stable, whereas others show rapid rates of evolutionary change.

  20. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  1. The Riddle of Sex.

    ERIC Educational Resources Information Center

    Sagan, Dorion; Margulis, Lynn

    1985-01-01

    Discusses the work of evolutionary biologists in determining how sexual reproduction arose. Topics explored include the nature of sex, bacterial sex, meiotic sex, and asexual reproduction. A diagram (which can be used as a duplicating master) illustrating types of bacterial sex is included. (DH)

  2. Heteromorphic sex chromosomes: navigating meiosis without a homologous partner.

    PubMed

    Checchi, Paula M; Engebrecht, Joanne

    2011-09-01

    Accurate chromosome segregation during meiosis relies on homology between the maternal and paternal chromosomes. Yet by definition, sex chromosomes of the heterogametic sex lack a homologous partner. Recent studies in a number of systems have shed light on the unique meiotic behavior of heteromorphic sex chromosomes, and highlight both the commonalities and differences in divergent species. During meiotic prophase, the homology-dependent processes of pairing, synapsis, and recombination have been modified in many different ways to ensure segregation of heteromorphic sex chromosomes at the first meiotic division. Additionally, an almost universal feature of heteromorphic sex chromosomes during meiosis is transcriptional silencing, or meiotic sex chromosome inactivation, an essential process proposed to prevent expression of genes deleterious to meiosis in the heterogametic sex as well as to shield unpaired sex chromosomes from recognition by meiotic checkpoints. Comparative analyses of the meiotic behavior of sex chromosomes in nematodes, mammals, and birds reveal important conserved features as well as provide insight into sex chromosome evolution.

  3. Sex Differences in Intellectual and Ego Development.

    ERIC Educational Resources Information Center

    Alishio, Kip C.; Schilling, Karen Maitland

    Perry's scheme of intellectual and ethical development was examined for sex differences with respect to content areas for which sex differences have elsewhere been suggested: occupational choice, interpersonal relationships, and sexual identity. In addition, the content area religion and ego development, as measured by Loevinger's sentence…

  4. Sex Stereotyping in Parents' Perceptions of Newborns.

    ERIC Educational Resources Information Center

    Karraker, Katherine Hildebrandt; Vogel, Dena Ann

    This study updates and extends the findings of Rubin, Provenzano, and Luria (1974), who found that parents perceived their newborn in sex stereotyped ways as early as a few hours after birth. In addition, fathers in their study showed more extreme sex stereotyping than mothers. Participants in the present study were 20 pairs of Caucasian,…

  5. Factors Affecting Attitudes toward Juvenile Sex Offenders

    ERIC Educational Resources Information Center

    Sahlstrom, Kimberly J.; Jeglic, Elizabeth L.

    2008-01-01

    This study investigated attitudes toward juvenile sex offenders and factors influencing those attitudes. Additionally, the influences of perpetrator characteristics such as age, gender, and ethnicity on societal attitudes towards intervention requirements were also investigated. Overall, attitudes toward juvenile sex offenders and their treatment…

  6. Sex Work among Men Who Have Sex with Men and Transgender Women in Bogotá

    PubMed Central

    Bianchi, Fernanda T.; Reisen, Carol A.; Zea, Maria Cecilia; Vidal-Ortiz, Salvador; Gonzales, Felisa A.; Betancourt, Fabián; Aguilar, Marcela; Poppen, Paul J.

    2014-01-01

    This qualitative study examined sex work among internally displaced male and transgender female sex workers in Bogotá, Colombia. Internal displacement has occurred in Colombia as a result of decades of conflict among armed groups and has created large-scale migration from rural to urban areas. Informed by the polymorphous model of sex work, which posits that contextual conditions shape the experience of sex work, we examined three main research questions. The first dealt with how internal displacement was related to the initiation of sex work; the second concerned the effect of agency on sex worker satisfaction; and the third examined how sex work in this context was related to HIV and other risks. Life history interviews were conducted with a 26 displaced individuals who had done sex work: 14 were men who have sex with men (MSM) and 12 were transgender women (natal males). Findings revealed that many participants began doing sex work in the period immediately after displacement, because of a lack of money, housing, and social support. HIV risk was greater during this time due to limited knowledge of HIV and inexperience negotiating safer sex with clients. Other findings indicated that sex workers who exerted more control and choice in the circumstances of their work reported greater satisfaction. In addition, we found that although many sex workers insisted on condom use with clients, several noted that they would sometimes have unprotected sex for additional money. Specific characteristics affecting the experience of sex work among the transgender women were also discussed. PMID:24464550

  7. Children's sex-related stereotyping of colors.

    PubMed

    Picariello, M L; Greenberg, D N; Pillemer, D B

    1990-10-01

    4 studies addressed children's sex-related stereotyping of colors. Study 1 examined preschoolers' awareness of color stereotypes. Children were presented with 6 toy animals, identical except for color, and were asked to identify the sex of each animal and to select a favorite. Both sex identifications and toy preferences were highly consistent with adult color stereotypes. Study 2 demonstrated that clothing color influences preschool, kindergarten, and first-grade children's impressions of other children whose sex is known. Studies 3 and 4 indicated that the effects of stereotyping based on color are modest in comparison to the effects of stereotyping based directly on sex. In addition, color stereotyping did not show the regular age-related increase that is characteristic of sex-role stereotyping.

  8. Food additives

    MedlinePlus

    ... or natural. Natural food additives include: Herbs or spices to add flavor to foods Vinegar for pickling ... Certain colors improve the appearance of foods. Many spices, as well as natural and man-made flavors, ...

  9. Sex Differences in Same-Sex Friendship.

    ERIC Educational Resources Information Center

    Caldwell, Mayta A.; Peplau, Letitia Anne

    1982-01-01

    College students answered questionnaires regarding number of same sex friends and frequency of interaction, typical and preferred kinds of interactions, and emotional intimacy. Men and women did not differ in number of friends, time spent with friends, nor in value placed on intimate friendships. Sex differences were found, however, in the nature…

  10. Unisexual cucumber flowers, sex and sex differentiation.

    PubMed

    Bai, Shu-Nong; Xu, Zhi-Hong

    2013-01-01

    Sex is a universal phenomenon in the world of eukaryotes. Attempts have been made to understand regulatory mechanisms for plant sex determination by investigating unisexual flowers. The cucumber plant is one of the model systems for studying how sex determination is regulated by phytohormones. A systematic investigation of the development of unisexual cucumber flowers is summarized here, and it is suggested that the mechanism of the unisexual flower can help us to understand how the process leading to one type of gametogenesis is prevented. Based on these findings, we concluded that the unisexual cucumber flowers is not an issue of sex differentiation, but instead a mechanism for avoiding self-pollination. Sex differentiation is essentially the divergent point(s) leading to heterogametogenesis. On the basis of analyses of sex differentiation in unicellular organisms and animals as well as the core process of plant life cycle, a concept of "sexual reproduction cycle" is proposed for understanding the essential role of sex and a "progressive model" for future investigations of sex differentiation in plants.

  11. HIV and female sex workers.

    PubMed Central

    Estébanez, P.; Fitch, K.; Nájera, R.

    1993-01-01

    In this review of published findings on human immunodeficiency virus (HIV) infection and risk factors among female sex workers, we summarize the results of seroprevalence studies in different countries and discuss the different patterns of transmission among such workers in various geographical regions. The highest rates of HIV infection occur in sub-Saharan Africa, where the widespread existence of sexually transmitted diseases may play an important role in sustaining transmission. In Europe and North America injecting drug use continues to be the major factor associated with HIV infection among female sex workers, while in Latin America and parts of Asia there is a more mixed pattern of heterosexual and parenteral transmission from injecting drug use. Reviewed also are studies of the risk factors associated with HIV infection among female sex workers, such as drug use, sexual behaviour, the presence of sexually transmitted diseases, and condom use; in addition, we comment on some studies of the clients of sex workers. Finally, we propose directions that future research in this area might take and discuss various interventions that need to be undertaken to reduce HIV transmission among female sex workers. PMID:8324860

  12. HIV and female sex workers.

    PubMed

    Estébanez, P; Fitch, K; Nájera, R

    1993-01-01

    In this review of published findings on human immunodeficiency virus (HIV) infection and risk factors among female sex workers, we summarize the results of seroprevalence studies in different countries and discuss the different patterns of transmission among such workers in various geographical regions. The highest rates of HIV infection occur in sub-Saharan Africa, where the widespread existence of sexually transmitted diseases may play an important role in sustaining transmission. In Europe and North America injecting drug use continues to be the major factor associated with HIV infection among female sex workers, while in Latin America and parts of Asia there is a more mixed pattern of heterosexual and parenteral transmission from injecting drug use. Reviewed also are studies of the risk factors associated with HIV infection among female sex workers, such as drug use, sexual behaviour, the presence of sexually transmitted diseases, and condom use; in addition, we comment on some studies of the clients of sex workers. Finally, we propose directions that future research in this area might take and discuss various interventions that need to be undertaken to reduce HIV transmission among female sex workers.

  13. Why we should consider sex (and study sex differences) in addiction research.

    PubMed

    Sanchis-Segura, Carla; Becker, Jill B

    2016-09-01

    Among mammals, every cell has a biological sex, and the sex of an individual pervades its body and brain. In this review, we describe the processes through which mammals become phenotypically male or female by organizational and activational influences of genes and hormones throughout development. We emphasized that the molecular and cellular changes triggered by sex chromosomes and steroid hormones may generate sex differences in overt physiological functions and behavior, but they may alternatively promote end-point convergences between males and females. Clinical and pre-clinical evidences suggest that sex and gender differences modulate drug consumption as well as of the transition towards drug-promoted pathological states such as dependence and addiction. Additionally, sex differences in drug pharmacokinetics and pharmacodynamics will also influence dependence and addiction as well as side effects of drugs. These effects will further interact with socially gendered factors to result in sex differences in the access to, engagement in and efficacy of any therapeutic attempt. Finally, we maintain that 'sex sameness' is as important as 'sex differences' when building a complete understanding of biology for both males and females and provide a framework with which to classify and guide investigation into the mechanisms mediating sex differences and sex sameness.

  14. Sex Drives Dimorphic Immune Responses to Viral Infections.

    PubMed

    Ghosh, Soumitra; Klein, Robyn S

    2017-03-01

    New attention to sexual dimorphism in normal mammalian physiology and disease has uncovered a previously unappreciated breadth of mechanisms by which females and males differentially exhibit quantitative phenotypes. Thus, in addition to the established modifying effects of hormones, which prenatally and postpubertally pattern cells and tissues in a sexually dimorphic fashion, sex differences are caused by extragonadal and dosage effects of genes encoded on sex chromosomes. Sex differences in immune responses, especially during autoimmunity, have been studied predominantly within the context of sex hormone effects. More recently, immune response genes have been localized to sex chromosomes themselves or found to be regulated by sex chromosome genes. Thus, understanding how sex impacts immunity requires the elucidation of complex interactions among sex hormones, sex chromosomes, and immune response genes. In this Brief Review, we discuss current knowledge and new insights into these intricate relationships in the context of viral infections.

  15. Same sex, no sex, and unaware sex in neurotoxicology.

    PubMed

    Weiss, Bernard

    2011-10-01

    Males and females of virtually all species differ in how they respond to their environment. Because such differences exist in almost all biological realms, including disease patterns and therapeutic outcomes, they have evoked calls by various bodies to incorporate their assessment in research. Neurobehavioral indices pose special questions because, unlike outwardly visible markers, they are described by complex functional outcomes or subtle alterations in brain structure. These divergent responses arise because they are inscribed in the genome itself and then by endocrine mechanisms that govern sexual differentiation of the brain during development and operate throughout life. Other organ systems that exhibit sex differences include the liver, an important consideration for neurotoxicology because it may process many toxic chemicals differentially in males and females. Despite the scope and pervasiveness of sex differences, however, they are disregarded by much of neurotoxicology research. Males predominate in behavioral experiments, few such experiments study both sexes, some investigators fail to even describe the sex of their subjects, and in vitro studies tend to wholly ignore sex, even for model systems aimed at neurological disorders that display marked sex differences. The public is acutely aware of sex differences in behavior, as attested by its appetite for books on the topic. It closely follows debates about the proportion of women in professions that feature science and mathematics. Neurotoxicology, especially in the domain of laboratory research, will be hindered in its ability to translate its findings into human health measures if it assigns sex differences to a minor role. It must also be sensitive to how such debates are framed. Often, the differences evoking the most discussion are subtle in scope. They do not lend themselves to the typical analyses conducted by experimenters; that is, reliance on mean differences and null hypothesis testing.

  16. Sex Education: Another View

    ERIC Educational Resources Information Center

    Hamilton, Jennifer

    1977-01-01

    The mother of a 14-year-old mentally retarded boy comments on the viewpoints of Dr. Sol Gordon (a sex education columnist) regarding masturbation, questions on sex, marriage, and the parents' role. (SBH)

  17. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  18. Phosphazene additives

    DOEpatents

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  19. Female Sex Offenders: Public Awareness and Attributions.

    PubMed

    Cain, Calli M; Anderson, Amy L

    2016-09-16

    Traditional gender roles, sex scripts, and the way female sex offenders are portrayed in the media may lead to misconceptions about who can commit sexual offenses. Sexual crimes by women may go unnoticed or unreported if there is a general lack of awareness that females commit these crimes. Data from the 2012 Nebraska Annual Social Indicators Survey were used to determine whether the public perceives women as capable sex offenders and the perceived causes of female sex offending. The traditional focus on male sex offenders by researchers, media, and politicians, in addition to gender stereotypes, introduces the possibility of group differences (e.g., between men and women) in perceptions of female sex offenders. Consequently, two secondary analyses were conducted that tested for group differences in both the public's perception of whether females can commit sex offenses and the explanations selected for why females sexually offend. The findings suggest that the public does perceive women as capable sex offenders, although there were group differences in the causal attributions for female sex offending.

  20. Changing Sex Roles.

    ERIC Educational Resources Information Center

    Worell, Judith

    This article reviews literature on sex role change in children and points to areas which need further research. Competing ideologies which support or reject sex typing of role behaviors are briefly discussed in the introduction. The sources of sex role change are divided into two categories: (1) planned direct intervention programs and (2) natural…

  1. Sex Education. Chapter Seventeen.

    ERIC Educational Resources Information Center

    Caster, Jerry A.

    Information and a framework that permits teachers to plan and initiate a successful sex education program for students with mental disabilities is provided. A major aspect of sex education should be its focus on social relationships, emotions, choice-making, and responsibilities to self and others. Sex education should not be viewed as a…

  2. Sex differences in the HPA axis.

    PubMed

    Goel, Nirupa; Workman, Joanna L; Lee, Tiffany T; Innala, Leyla; Viau, Victor

    2014-07-01

    The hypothalamic-pituitary-adrenal (HPA) axis is a major component of the systems that respond to stress, by coordinating the neuroendocrine and autonomic responses. Tightly controlled regulation of HPA responses is critical for maintaining mental and physical health, as hyper- and hypo-activity have been linked to disease states. A long history of research has revealed sex differences in numerous components of the HPA stress system and its responses, which may partially form the basis for sex disparities in disease development. Despite this, many studies use male subjects exclusively, while fewer reports involve females or provide direct sex comparisons. The purpose of this article is to present sex comparisons in the functional and molecular aspects of the HPA axis, through various phases of activity, including basal, acute stress, and chronic stress conditions. The HPA axis in females initiates more rapidly and produces a greater output of stress hormones. This review focuses on the interactions between the gonadal hormone system and the HPA axis as the key mediators of these sex differences, whereby androgens increase and estrogens decrease HPA activity in adulthood. In addition to the effects of gonadal hormones on the adult response, morphological impacts of hormone exposure during development are also involved in mediating sex differences. Additional systems impinging on the HPA axis that contribute to sex differences include the monoamine neurotransmitters norepinephrine and serotonin. Diverse signals originating from the brain and periphery are integrated to determine the level of HPA axis activity, and these signals are, in many cases, sex-specific.

  3. Zebrafish sex: a complicated affair

    PubMed Central

    Liew, Woei Chang

    2014-01-01

    In this review, we provide a detailed overview of studies on the elusive sex determination (SD) and gonad differentiation mechanisms of zebrafish (Danio rerio). We show that the data obtained from most studies are compatible with polygenic sex determination (PSD), where the decision is made by the allelic combinations of several loci. These loci are typically dispersed throughout the genome, but in some teleost species a few of them might be located on a preferential pair of (sex) chromosomes. The PSD system has a much higher level of variation of SD genotypes both at the level of gametes and the sexual genotype of individuals, than that of the chromosomal sex determination systems. The early sexual development of zebrafish males is a complicated process, as they first develop a ‘juvenile ovary’, that later undergoes a transformation to give way to a testis. To date, three major developmental pathways were shown to be involved with gonad differentiation through the modulation of programmed cell death. In our opinion, there are more pathways participating in the regulation of zebrafish gonad differentiation/transformation. Introduction of additional powerful large-scale genomic approaches into the analysis of zebrafish reproduction will result in further deepening of our knowledge as well as identification of additional pathways and genes associated with these processes in the near future. PMID:24148942

  4. Project: Strategies for Sex Fairness. Evaluating Our School for Sex Fairness.

    ERIC Educational Resources Information Center

    Mook, Corena; Legg, Marilyn

    One of a series of instructional packets to aid schools in reducing sex stereotypes, this inservice guide for use with school personnel is designed to assist vocational schools and programs in evaluating their site for sex fairness. Covered are evaluations required by legislation and additional evaluations that may be added because of local…

  5. Sexing young snowy owls

    USGS Publications Warehouse

    Seidensticker, M.T.; Holt, D.W.; Detienne, J.; Talbot, S.; Gray, K.

    2011-01-01

    We predicted sex of 140 Snowy Owl (Bubo scandiacus) nestlings out of 34 nests at our Barrow, Alaska, study area to develop a technique for sexing these owls in the field. We primarily sexed young, flightless owls (3844 d old) by quantifying plumage markings on the remiges and tail, predicting sex, and collecting blood samples to test our field predictions using molecular sexing techniques. We categorized and quantified three different plumage markings: two types of bars (defined as markings that touch the rachis) and spots (defined as markings that do not touch the rachis). We predicted sex in the field assuming that males had more spots than bars and females more bars than spots on the remiges and rectrices. Molecular data indicated that we correctly sexed 100% of the nestlings. We modeled the data using random forests and classification trees. Both models indicated that the number and type of markings on the secondary feathers were the most important in classifying nestling sex. The statistical models verified our initial qualitative prediction that males have more spots than bars and females more bars than spots on flight feathers P6P10 for both wings and tail feathers T1 and T2. This study provides researchers with an easily replicable and highly accurate method for sexing young Snowy Owls in the field, which should aid further studies of sex-ratios and sex-related variation in behavior and growth of this circumpolar owl species. ?? 2011 The Raptor Research Foundation, Inc.

  6. Osho - Insights on sex

    PubMed Central

    Nagaraj, Anil Kumar Mysore

    2013-01-01

    Sex is a mysterious phenomenon, which has puzzled even great sages. Human beings have researched and mastered the biology of sex. But that is not all. Sex needs to be understood from the spiritual perspective too. The vision of Osho is an enlightening experience in this regard. Out of the thousands of lectures, five lectures on sex made Osho most notorious. Born into a Jain family of Madhya Pradesh, Rajneesh, who later wanted himself to be called Osho, is a great master. He has spoken volumes on a wide range of topics ranging from sex to super-consciousness. His contributions in the area of sex are based on the principles of “Tantra” which has its origin from Buddhism. This article focuses on his life and insights on sex, which if understood properly, can be a stepping stone for enlightenment. PMID:23858266

  7. Dosage Compensation of the Sex Chromosomes

    PubMed Central

    Disteche, Christine M.

    2013-01-01

    Differentiated sex chromosomes evolved because of suppressed recombination once sex became genetically controlled. In XX/XY and ZZ/ZW systems, the heterogametic sex became partially aneuploid after degeneration of the Y or W. Often, aneuploidy causes abnormal levels of gene expression throughout the entire genome. Dosage compensation mechanisms evolved to restore balanced expression of the genome. These mechanisms include upregulation of the heterogametic chromosome as well as repression in the homogametic sex. Remarkably, strategies for dosage compensation differ between species. In organisms where more is known about molecular mechanisms of dosage compensation, specific protein complexes containing noncoding RNAs are targeted to the X chromosome. In addition, the dosage-regulated chromosome often occupies a specific nuclear compartment. Some genes escape dosage compensation, potentially resulting in sex-specific differences in gene expression. This review focuses on dosage compensation in mammals, with comparisons to fruit flies, nematodes, and birds. PMID:22974302

  8. Sex steroids: beyond conventional dimorphism.

    PubMed

    Lavranos, Giagkos; Angelopoulou, Roxani; Manolakou, Panagiota; Katsiki, Evangelia

    2013-09-01

    Sexual dimorphism is a characteristic of a large number of species, ranging from lower invertebrates to mammals and, last but not least, humans. Recognition of the various factors regulating sexual dimorphism initial establishment (i.e. sex determination and differentiation) and subsequent life-long adaptation to distinct functional and behavioural patterns has remained a hot topic for several decades. As our understanding of the various molecular pathways involved in this process increases, the significant role of sex steroids becomes more evident. At the same time, the recognition of new sites of steroid production (e.g. parts of the brain) and aromatization, as well as new target cells (owing to the proposed presence of additional receptors to those classically considered as primary steroid receptors) has lead to the need to revisit their spectrum of actions within a novel, multifactorial context. Thus, anthropology and medicine are presented with the challenge to unravel a major mystery, i.e. that of sexual orientation and differentiation and its potential contribution in human evolution and civilization development, taking advantage of the high-tech research tools provided by modern biotechnology. This short review summarizes the basic principles of sex determination and sex steroid function as they have been classically described in the literature and then proceeds to present examples of how modern research methods have started to offer a new insight on the more subtle details of this process, stressing that it is extending to virtually every single part and system of the body.

  9. Sex, epilepsy, and epigenetics

    PubMed Central

    Qureshi, Irfan A.; Mehler, Mark F.

    2014-01-01

    Epilepsy refers to a heterogeneous group of disorders that are associated with a wide range of pathogenic mechanisms, seizure manifestations, comorbidity profiles, and therapeutic responses. These characteristics are all influenced quite significantly by sex. As with other conditions exhibiting such patterns, sex differences in epilepsy are thought to arise—at the most fundamental level—from the “organizational” and “activational” effects of sex hormones as well as from the direct actions of the sex chromosomes. However, our understanding of the specific molecular, cellular, and network level processes responsible for mediating sex differences in epilepsy remains limited. Because increasing evidence suggests that epigenetic mechanisms are involved both in epilepsy and in brain sexual dimorphism, we make the case here that analyzing epigenetic regulation will provide novel insights into the basis for sex differences in epilepsy. PMID:24998474

  10. Doing gender in sex and sex research.

    PubMed

    Vanwesenbeeck, Ine

    2009-12-01

    Gender is central to sexuality, and vice versa, but there are a number of difficulties with the treatment of gender in sex research. Apparently, it is hard to find a balance between two conflicting needs. First, obviously, it is necessary to make distinctions between women and men, for political as well as research-technical and theoretical reasons. A second requirement, at odds with the first one, is the necessity to understand gender and its relation to sexuality and the body as much more complex than simplistically referring to two sets of individuals. This is all the more necessary when one realizes the possible drawbacks of exaggerating the differences between the sexes (in particular when they are biologically explained), because of stereotyping, stigmatizing, and expectancy confirmatory processes. This essay identifies and discusses 10 difficulties in the treatment of gender in sex research, reflects on their origins, and reviews theory and evidence with the aim to (1) consider the relative strength of gender/sex as an explanatory variable compared to other factors and processes explaining differences between men and women on a number of sexual aspects, (2) inform an understanding of gender and its relation to sexuality as an ongoing, open-ended, multi-determined, situated, interactional process, with the body as a third player, and (3) argue in favor of a nuanced, well-balanced treatment of gender in sex research.

  11. Neo-sex chromosome inheritance across species in Silene hybrids.

    PubMed

    Weingartner, L A; Delph, L F

    2014-07-01

    Neo-sex chromosomes, which form through the major restructuring of ancestral sex chromosome systems, have evolved in various taxa. Such restructuring often consists of the fusion of an autosome to an existing sex chromosome, resulting in novel sex chromosome formations (e.g. X1X2Y or XY1Y2.). Comparative studies are often made between restructured sex chromosome systems of closely related species, and here we evaluate the consequences of variable sex chromosome systems to hybrids. If neo-sex chromosomes are improperly inherited across species, this could lead to aberrant development and reproductive isolation. In this study, we examine the fate of neo-sex chromosomes in hybrids of the flowering plants Silene diclinis and Silene latifolia. Silene diclinis has a neo-sex chromosome system (XY1Y2) that is thought to have evolved from an ancestral XY system that is still present in S. latifolia. These species do not hybridize naturally, and improper sex chromosome inheritance could contribute to reproductive isolation. We investigated whether this major restructuring of sex chromosomes prevents their proper inheritance in a variety of hybrid crosses, including some F2 - and later-generation hybrids, with sex chromosome-linked, species-specific, polymorphic markers and chromosome squashes. We discovered that despite the differences in sex chromosomes that exist between these two species, proper segregation had occurred in hybrids that made it to flowering, including later-generation hybrids, indicating that neo-sex chromosome formation alone does not result in complete reproductive isolation between these two species. Additionally, hybrids with aberrant sex expression (e.g. neuter, hermaphrodite) also inherited the restructured sex chromosomes properly, highlighting that issues with sexual development in hybrids can be caused by intrinsic genetic incompatibility rather than improper sex chromosome inheritance.

  12. Safe sex self-efficacy and safe sex practice in a Southern United States College

    PubMed Central

    Addoh, Ovuokerie; Sng, Eveleen; Loprinzi, Paul D.

    2017-01-01

    Background: The purpose of this study was to assess the association between safe sex self-efficacy and safe-sex practice in a Southern college setting. Methods: Multivariable logistic regression models were used to examine the association between safe sex self-efficacy in four domains (mechanics, partner disapproval, assertiveness, intoxicants) and safe sex practice (outcome variable). Results: For every 1-unit increase in the composite condom use self-efficacy score, there was an 8% increase in the odds of being beyond the median safe-sex practice score (odds ration [OR]: 1.08, 95% CI: 1.02-1.15). Additionally, for every 1-unit increase in intoxicants self-efficacy score, there was a 31% increase in the odds of being beyond the median safe-sex practice score (OR: 1.31, 95% CI: 1.08-1.58). Conclusion: A greater degree of safe-sex self-efficacy is associated with increased odds of safe-sex practice. These findings are informative for the development of targeted approaches to foster safe-sex behavior in Southern US colleges. PMID:28326287

  13. Safe sex self-efficacy and safe sex practice in a Southern United States College.

    PubMed

    Addoh, Ovuokerie; Sng, Eveleen; Loprinzi, Paul D

    2017-01-01

    Background: The purpose of this study was to assess the association between safe sex self-efficacy and safe-sex practice in a Southern college setting. Methods: Multivariable logistic regression models were used to examine the association between safe sex self-efficacy in four domains (mechanics, partner disapproval, assertiveness, intoxicants) and safe sex practice (outcome variable). Results: For every 1-unit increase in the composite condom use self-efficacy score, there was an 8% increase in the odds of being beyond the median safe-sex practice score (odds ration [OR]: 1.08, 95% CI: 1.02-1.15). Additionally, for every 1-unit increase in intoxicants self-efficacy score, there was a 31% increase in the odds of being beyond the median safe-sex practice score (OR: 1.31, 95% CI: 1.08-1.58). Conclusion: A greater degree of safe-sex self-efficacy is associated with increased odds of safe-sex practice. These findings are informative for the development of targeted approaches to foster safe-sex behavior in Southern US colleges.

  14. Neurogenin 3 mediates sex chromosome effects on the generation of sex differences in hypothalamic neuronal development

    PubMed Central

    Scerbo, María J.; Freire-Regatillo, Alejandra; Cisternas, Carla D.; Brunotto, Mabel; Arevalo, Maria A.; Garcia-Segura, Luis M.; Cambiasso, María J.

    2014-01-01

    The organizational action of testosterone during critical periods of development is the cause of numerous sex differences in the brain. However, sex differences in neuritogenesis have been detected in primary neuronal hypothalamic cultures prepared before the peak of testosterone production by fetal testis. In the present study we assessed the hypothesis of that cell-autonomous action of sex chromosomes can differentially regulate the expression of the neuritogenic gene neurogenin 3 (Ngn3) in male and female hypothalamic neurons, generating sex differences in neuronal development. Neuronal cultures were prepared from male and female E14 mouse hypothalami, before the fetal peak of testosterone. Female neurons showed enhanced neuritogenesis and higher expression of Ngn3 than male neurons. The silencing of Ngn3 abolished sex differences in neuritogenesis, decreasing the differentiation of female neurons. The sex difference in Ngn3 expression was determined by sex chromosomes, as demonstrated using the four core genotypes mouse model, in which a spontaneous deletion of the testis-determining gene Sry from the Y chromosome was combined with the insertion of the Sry gene onto an autosome. In addition, the expression of Ngn3, which is also known to mediate the neuritogenic actions of estradiol, was increased in the cultures treated with the hormone, but only in those from male embryos. Furthermore, the hormone reversed the sex differences in neuritogenesis promoting the differentiation of male neurons. These findings indicate that Ngn3 mediates both cell-autonomous actions of sex chromosomes and hormonal effects on neuritogenesis. PMID:25071448

  15. The evolution of sex chromosomes in organisms with separate haploid sexes.

    PubMed

    Immler, Simone; Otto, Sarah Perin

    2015-03-01

    The evolution of dimorphic sex chromosomes is driven largely by the evolution of reduced recombination and the subsequent accumulation of deleterious mutations. Although these processes are increasingly well understood in diploid organisms, the evolution of dimorphic sex chromosomes in haploid organisms (U/V) has been virtually unstudied theoretically. We analyze a model to investigate the evolution of linkage between fitness loci and the sex-determining region in U/V species. In a second step, we test how prone nonrecombining regions are to degeneration due to accumulation of deleterious mutations. Our modeling predicts that the decay of recombination on the sex chromosomes and the addition of strata via fusions will be just as much a part of the evolution of haploid sex chromosomes as in diploid sex chromosome systems. Reduced recombination is broadly favored, as long as there is some fitness difference between haploid males and females. The degeneration of the sex-determining region due to the accumulation of deleterious mutations is expected to be slower in haploid organisms because of the absence of masking. Nevertheless, balancing selection often drives greater differentiation between the U/V sex chromosomes than in X/Y and Z/W systems. We summarize empirical evidence for haploid sex chromosome evolution and discuss our predictions in light of these findings.

  16. Sex tourism in Thailand.

    PubMed

    Van Kerkwijk, C

    1992-01-01

    Many foreigners visit Thailand in search of sex. While long-distance tourism was long enjoyed by members of more privileged social classes, even the lower economical classes of Japan, Malaysia, Europe, America, and Australia can now afford to travel over long distances. This relatively new breed of tourist is more likely to be of lower socioeconomic and educational status and less likely to use condoms when having sex. An estimated 30,000 sex workers are active in Bangkok, of whom 7000/10,000 are females who work specifically in the tourism sector. 1/2-1/3 of the 600 commercial sex establishments in the city are visited by foreigners. Phuket, Pattaya, Koh Samui, and Chiangmai are also well-frequented by sex tourists. Overall, a large, diverse, inexpensive, and accessible commercial sex market exists in Thailand. One may meet sex workers quasi-ubiquitously and be assured to find someone capable of meeting one's sexual needs. With these attributes, Thailand strongly attracts tourists in search of sex. A certain degree of recklessness also prevails among those on vacation. Away from the peers and social mores of their native lands, tourists may engage in sexually activities without criticism. Likewise, Thai sex workers who cater to foreigners, especially females, enjoy more freedom and control in sexual relations than their peers who work among nationals. Neither single nor married women in Thailand are allowed much sexual freedom and are traditionally expected to be obliging docile, and submissive. The greater than normal personal latitude enjoyed by both sex worker and foreigner lead to more negotiation on condom use and overall lower use. As such, Thailand's commercial sex market with foreigners' involvement therein threatens to spread HIV to many other countries throughout the world.

  17. Plant Sex Determination.

    PubMed

    Pannell, John R

    2017-03-06

    Sex determination is as important for the fitness of plants as it is for animals, but its mechanisms appear to vary much more among plants than among animals, and the expression of gender in plants differs in important respects from that in most animals. In this Minireview, I provide an overview of the broad variety of ways in which plants determine sex. I suggest that several important peculiarities of plant sex determination can be understood by recognising that: plants show an alternation of generations between sporophytic and gametophytic phases (either of which may take control of sex determination); plants are modular in structure and lack a germ line (allowing for a quantitative expression of gender that is not common in animals); and separate sexes in plants have ultimately evolved from hermaphroditic ancestors. Most theorising about sex determination in plants has focused on dioecious species, but we have much to learn from monecious or hermaphroditic species, where sex is determined at the level of modules, tissues or cells. Because of the fundamental modularity of plant development and potentially important evolutionary links between monoecy and dioecy, it may be useful to relax the distinction often made between 'developmental sex determination' (which underpins the development of male versus female flowers in monoecious species) and 'genetic sex determination' (which underpins the separation of males and females in dioecious species, often mediated by a genetic polymorphism and sex chromosomes). I also argue for relaxing the distinction between sex determination involving a genetic polymorphism and that involving responses to environmental or hormonal cues, because non-genetic cues might easily be converted into genetic switches.

  18. Single-Sex Classrooms

    ERIC Educational Resources Information Center

    Protheroe, Nancy

    2009-01-01

    Although single-sex education was once the norm in the U.S., the practice has largely been confined to private schools for more than a century. However, with the introduction of the final version of the U.S. Department of Education's so-called single-sex regulations in 2006, public schools were allowed greater flexibility to offer single-sex…

  19. Sex and America's Teenagers.

    ERIC Educational Resources Information Center

    Alan Guttmacher Inst., New York, NY.

    Although sexual activity is common among teenagers, it is not as widespread, and does not begin as early, as most adults believe. This report provides detailed data and analysis of sex among adolescents. Adolescent sexual activity is grouped in ten categories: (1) Rites of passage; (2) The context of adolescents' lives; (3) Sex among teenagers;…

  20. Sex Discrimination in Coaching.

    ERIC Educational Resources Information Center

    Dessem, Lawrence

    1980-01-01

    Even in situations in which the underpayment of girls' coaches is due to the sex of the students coached rather than to the sex of the coaches, the coaches and the girls coached are victims of unlawful discrimination. Available from Harvard Women's Law Journal, Harvard Law School, Cambridge, MA 02138. (Author/IRT)

  1. Sex Chromosome Drive

    PubMed Central

    Helleu, Quentin; Gérard, Pierre R.; Montchamp-Moreau, Catherine

    2015-01-01

    Sex chromosome drivers are selfish elements that subvert Mendel's first law of segregation and therefore are overrepresented among the products of meiosis. The sex-biased progeny produced then fuels an extended genetic conflict between the driver and the rest of the genome. Many examples of sex chromosome drive are known, but the occurrence of this phenomenon is probably largely underestimated because of the difficulty to detect it. Remarkably, nearly all sex chromosome drivers are found in two clades, Rodentia and Diptera. Although very little is known about the molecular and cellular mechanisms of drive, epigenetic processes such as chromatin regulation could be involved in many instances. Yet, its evolutionary consequences are far-reaching, from the evolution of mating systems and sex determination to the emergence of new species. PMID:25524548

  2. The many faces of sex work

    PubMed Central

    Harcourt, C; Donovan, B

    2005-01-01

    Objective: To compile a global typography of commercial sex work. Methods: A Medline search and review of 681 "prostitution" articles was conducted. In addition, the investigators pooled their 20 years of collected papers and monographs, and their observations in more than 15 countries. Arbitrary categories were developed to compile a workable typology of sex work. Results: At least 25 types of sex work were identified according to worksite, principal mode of soliciting clients, or sexual practices. These types of work are often grouped under the headings of "direct" and "indirect" prostitution, with the latter group less likely to be perceived or to perceive themselves as sex workers. In general, policing sex work can change its typology and location but its prevalence is rarely affected. The public health implications of sex work vary widely. Conclusion: Developing comprehensive sexual health promotion programmes requires a complete understanding of the types of sex work in a particular area. This study provides a checklist for developing appropriate and targeted programmes. PMID:15923285

  3. A predictive relationship between population and genetic sex ratios in clonal species

    NASA Astrophysics Data System (ADS)

    McLetchie, D. Nicholas; García-Ramos, Gisela

    2017-04-01

    Sexual reproduction depends on mate availability that is reflected by local sex ratios. In species where both sexes can clonally expand, the population sex ratio describes the proportion of males, including clonally derived individuals (ramets) in addition to sexually produced individuals (genets). In contrast to population sex ratio that accounts for the overall abundance of the sexes, the genetic sex ratio reflects the relative abundance of genetically unique mates, which is critical in predicting effective population size but is difficult to estimate in the field. While an intuitive positive relationship between population (ramet) sex ratio and genetic (genet) sex ratio is expected, an explicit relationship is unknown. In this study, we determined a mathematical expression in the form of a hyperbola that encompasses a linear to a nonlinear positive relationship between ramet and genet sex ratios. As expected when both sexes clonally have equal number of ramets per genet both sex ratios are identical, and thus ramet sex ratio becomes a linear function of genet sex ratio. Conversely, if sex differences in ramet number occur, this mathematical relationship becomes nonlinear and a discrepancy between the sex ratios amplifies from extreme sex ratios values towards intermediate values. We evaluated our predictions with empirical data that simultaneously quantified ramet and genet sex ratios in populations of several species. We found that the data support the predicted positive nonlinear relationship, indicating sex differences in ramet number across populations. However, some data may also fit the null model, which suggests that sex differences in ramet number were not extensive, or the number of populations was too small to capture the curvature of the nonlinear relationship. Data with lack of fit suggest the presence of factors capable of weakening the positive relationship between the sex ratios. Advantages of this model include predicting genet sex ratio using

  4. Sex and Fertility After SCI

    MedlinePlus

    ... About Blog Facing Disability Jeff Shannon Donate Experts \\ Sex and Fertility After Spinal Cord Injury Topics Adult ... Spasticity, Physical Therapy-Lokomat Spasticity, Physical Therapy-Lokomat Sex and Fertility After Spinal Cord Injury Sex and ...

  5. Hepatitis C: Sex and Sexuality

    MedlinePlus

    ... with Hepatitis » Sex and Sexuality: Entire Lesson Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For ... hepatitis C virus through sex. Can you pass hepatitis C to a sex partner? Yes, but it ...

  6. Early Sex Work Initiation and Violence against Female Sex Workers in Mombasa, Kenya.

    PubMed

    Parcesepe, Angela M; L'Engle, Kelly L; Martin, Sandra L; Green, Sherri; Suchindran, Chirayath; Mwarogo, Peter

    2016-12-01

    Between 20 and 40 % of female sex workers (FSWs) began sex work before age 18. Little is known concerning whether early initiation of sex work impacts later experiences in adulthood, including violence victimization. This paper examines the relationship between early initiation of sex work and violence victimization during adulthood. The sample included 816 FSWs in Mombasa, Kenya, recruited from HIV prevention drop-in centers who were 18 years or older and moderate-risk drinkers. Early initiation was defined as beginning sex work at 17 or younger. Logistic regression modeled recent violence as a function of early initiation, adjusting for drop-in center, age, education, HIV status, supporting others, and childhood abuse. Twenty percent of the sample reported early initiation of sex work. Although both early initiators and other FSWs reported commonly experiencing recent violence, early initiators were significantly more likely to experience recent physical and sexual violence and verbal abuse from paying partners. Early initiation was not associated with physical or sexual violence from non-paying partners. Many FSWs begin sex work before age 18. Effective interventions focused on preventing this are needed. In addition, interventions are needed to prevent violence against all FSWs, in particular, those who initiated sex work during childhood or adolescence.

  7. Altering the sex determination pathway in Drosophila fat body modifies sex-specific stress responses

    PubMed Central

    Neckameyer, Wendi S.

    2014-01-01

    The stress response in Drosophila melanogaster reveals sex differences in behavior, similar to what has been observed in mammals. However, unlike mammals, the sex determination pathway in Drosophila is well established, making this an ideal system to identify factors involved in the modulation of sex-specific responses to stress. In this study, we show that the Drosophila fat body, which has been shown to be important for energy homeostasis and sex determination, is a dynamic tissue that is altered in response to stress in a sex and time-dependent manner. We manipulated the sex determination pathway in the fat body via targeted expression of transformer and transformer-2 and analyzed these animals for changes in their response to stress. In the majority of cases, manipulation of transformer or transformer-2 was able to change the physiological output in response to starvation and oxidative stress to that of the opposite sex. Our data also uncover the possibility of additional downstream targets for transformer and transformer-2 that are separate from the sex determination pathway and can influence behavioral and physiological responses. PMID:24789992

  8. Sexing a sex-role-reversed species based on plumage: potential challenges in the red phalarope

    PubMed Central

    Ditlecadet, Delphine; Martin, Luc J.; Lanctot, Richard B.; Lecomte, Nicolas

    2016-01-01

    Sex-role reversal, in which males care for offspring, can occur when mate competition is stronger between females than males. Secondary sex traits and mate attracting displays in sex-role-reversed species are usually more pronounced in females than in males. The red phalarope (Phalaropus fulicarius) is a textbook example of a sex-role-reversed species. It is generally agreed that males are responsible for all incubation and parental care duties, whereas females typically desert males after having completed a clutch and may pair with new males to lay additional clutches. The breeding plumage of female red phalaropes is usually more brightly colored than male plumage, a reversed sexual dichromatism usually associated with sex-role reversal. Here, we confirm with PCR-based sexing that male red phalaropes can exhibit both the red body plumage typical of a female and the incubation behavior typical of a male. Our result, combined with previous observations of brightly colored red phalaropes incubating nests at the same arctic location (Igloolik Island, Nunavut, Canada), suggests that plumage dichromatism alone may not be sufficient to distinguish males from females in this breeding population of red phalaropes. This stresses the need for more systematic genetic sexing combined with standardized description of intersexual differences in red phalarope plumages. Determining whether such female-like plumage on males is a result of phenotypic plasticity or genetic variation could contribute to further understanding sex-role reversal strategies in the short Arctic summer. PMID:27168992

  9. Beliefs About Sex and Parent-Child-Church Sex Communication Among Church-Based African American Youth.

    PubMed

    Moore, Erin; Berkley-Patton, Jannette; Bohn, Alexandria; Hawes, Starlyn; Bowe-Thompson, Carole

    2015-10-01

    Parent-child sex communication has been shown to be protective against sexual risk among African American youth. The current study sought to use the theory of planned behavior as a framework for focus group discussions (N = 54 youth participants aged 12-19 years) to explore church youths' (a) sex beliefs and values (attitudes), (b) sources and evaluation of sex communication and education (subjective norms), (c) facilitator/barriers to adolescent sexual risk reduction and communication behaviors (perceived behavioral control), and (d) intentions to engage in these behaviors. Additionally, participants identified strategies for consideration in developing tailored parent-child-church sex communication education programs for use in African American churches. Themes suggested both positive and negative attitudes toward premarital sex and parents and churches as key sources of sex education and communication. Strategies to enhance parent-child-church sex communication are discussed in the context of these findings.

  10. Sex investment ratios in eusocial Hymenoptera support inclusive fitness theory.

    PubMed

    Bourke, A F G

    2015-11-01

    Inclusive fitness theory predicts that sex investment ratios in eusocial Hymenoptera are a function of the relatedness asymmetry (relative relatedness to females and males) of the individuals controlling sex allocation. In monogynous ants (with one queen per colony), assuming worker control, the theory therefore predicts female-biased sex investment ratios, as found in natural populations. Recently, E.O. Wilson and M.A. Nowak criticized this explanation and presented an alternative hypothesis. The Wilson-Nowak sex ratio hypothesis proposes that, in monogynous ants, there is selection for a 1 : 1 numerical sex ratio to avoid males remaining unmated, which, given queens exceed males in size, results in a female-biased sex investment ratio. The hypothesis also asserts that, contrary to inclusive fitness theory, queens not workers control sex allocation and queen-worker conflict over sex allocation is absent. Here, I argue that the Wilson-Nowak sex ratio hypothesis is flawed because it contradicts Fisher's sex ratio theory, which shows that selection on sex ratio does not maximize the number of mated offspring and that the sex ratio proposed by the hypothesis is not an equilibrium for the queen. In addition, the hypothesis is not supported by empirical evidence, as it fails to explain 'split' (bimodal) sex ratios or data showing queen and worker control and ongoing queen-worker conflict. By contrast, these phenomena match predictions of inclusive fitness theory. Hence, the Wilson-Nowak sex ratio hypothesis fails both as an alternative hypothesis for sex investment ratios in eusocial Hymenoptera and as a critique of inclusive fitness theory.

  11. B chromosomes and sex in animals.

    PubMed

    Camacho, J P M; Schmid, M; Cabrero, J

    2011-01-01

    Supernumerary (B) chromosomes are dispensable elements found in many eukaryote genomes in addition to standard (A) chromosomes. In many respects, B chromosomes resemble sex chromosomes, so that a common ancestry for them has frequently been suggested. For instance, B chromosomes in grasshoppers, and other insects, show a pycnotic cycle of condensation-decondensation during meiosis remarkably similar to that of the X chromosome. In some cases, B chromosome size is even very similar to that of the X chromosome. These resemblances have led to suggest the X as the B ancestor in many cases. In addition, sex chromosome origin from B chromosomes has also been suggested. In this article, we review the existing evidence for both evolutionary pathways, as well as sex differences for B frequency at adult and embryo progeny levels, B chromosome effects or B chromosome transmission. In addition, we review cases found in the literature showing sex-ratio distortion associated with B chromosome presence, the most extreme case being the paternal sex ratio (PSR) chromosomes in some Hymenoptera. We finally analyse the possibility of B chromosome regularisation within the host genome and, as a consequence of it, whether B chromosomes can become regular members of the host genome.

  12. Multiple Sex-Associated Regions and a Putative Sex Chromosome in Zebrafish Revealed by RAD Mapping and Population Genomics

    PubMed Central

    Anderson, Jennifer L.; Rodríguez Marí, Adriana; Braasch, Ingo; Amores, Angel; Hohenlohe, Paul; Batzel, Peter; Postlethwait, John H.

    2012-01-01

    Within vertebrates, major sex determining genes can differ among taxa and even within species. In zebrafish (Danio rerio), neither heteromorphic sex chromosomes nor single sex determination genes of large effect, like Sry in mammals, have yet been identified. Furthermore, environmental factors can influence zebrafish sex determination. Although progress has been made in understanding zebrafish gonad differentiation (e.g. the influence of germ cells on gonad fate), the primary genetic basis of zebrafish sex determination remains poorly understood. To identify genetic loci associated with sex, we analyzed F2 offspring of reciprocal crosses between Oregon *AB and Nadia (NA) wild-type zebrafish stocks. Genome-wide linkage analysis, using more than 5,000 sequence-based polymorphic restriction site associated (RAD-tag) markers and population genomic analysis of more than 30,000 single nucleotide polymorphisms in our *ABxNA crosses revealed a sex-associated locus on the end of the long arm of chr-4 for both cross families, and an additional locus in the middle of chr-3 in one cross family. Additional sequencing showed that two SNPs in dmrt1 previously suggested to be functional candidates for sex determination in a cross of ABxIndia wild-type zebrafish, are not associated with sex in our AB fish. Our data show that sex determination in zebrafish is polygenic and that different genes may influence sex determination in different strains or that different genes become more important under different environmental conditions. The association of the end of chr-4 with sex is remarkable because, unique in the karyotype, this chromosome arm shares features with known sex chromosomes: it is highly heterochromatic, repetitive, late replicating, and has reduced recombination. Our results reveal that chr-4 has functional and structural properties expected of a sex chromosome. PMID:22792396

  13. Testicular Cancer and Sex

    MedlinePlus

    ... remove just one testicle, called an inguinal orchiectomy (IO), does not make a patient impotent and seldom ... everything from having sex the day after their IO (ouch!) all the way through having to go ...

  14. Sex during Pregnancy

    MedlinePlus

    ... results. Health care providers sometimes also recommend avoiding anal sex during pregnancy. If significant complications with your ... October 2016 previous 1 • 2 For Teens For Kids For Parents MORE ON THIS TOPIC Pregnancy & Newborn ...

  15. Juvenile Sex Offenders.

    PubMed

    Ryan, Eileen P; Otonichar, Joseph M

    2016-07-01

    Sexual offending by juveniles accounts for a sizable percentage of sexual offenses, especially against young children. In this article, recent research on female juvenile sex offenders (JSOs), risk factors for offending in juveniles, treatment, and the ways in which these youth may differ from general delinquents will be reviewed. Most JSOs do not go on to develop paraphilic disorders or to commit sex offenses during adulthood, and as a group, they are more similar to nonsexual offending juvenile delinquents than to adult sex offenders. Recent research has elucidated some differences between youth who commit sex offenses and general delinquents in the areas of atypical sexual interests, the use of pornography, and early sexual victimization during childhood.

  16. Sex-biased avian host use by arbovirus vectors

    PubMed Central

    Burkett-Cadena, Nathan D.; Bingham, Andrea M.; Unnasch, Thomas R.

    2014-01-01

    Prevalence of arthropod-borne parasites often differs drastically between host sexes. This sex-related disparity may be related to physiological (primarily hormonal) differences that facilitate or suppress replication of the pathogen in host tissues. Alternately, differences in pathogen prevalence between host sexes may be owing to differential exposure to infected vectors. Here, we report on the use of PCR-based assays recognizing bird sex chromosomes to investigate sex-related patterns of avian host use from field-collected female mosquitoes from Florida, USA. Mosquitoes took more bloodmeals from male birds (64.0% of 308 sexed samples) than female birds (36.0%), deviating significantly from a hypothetical 1:1 sex ratio. In addition, male-biased host use was consistent across mosquito species (Culex erraticus (64.4%); Culex nigripalpus (61.0%) and Culiseta melanura (64.9%)). Our findings support the hypothesis that sex-biased exposure to vector-borne pathogens contributes to disparities in parasite/pathogen prevalence between the sexes. While few studies have yet to investigate sex-biased host use by mosquitoes, the methods used here could be applied to a variety of mosquito-borne disease systems, including those that affect health of humans, domestic animals and wildlife. Understanding the mechanisms that drive sex-based disparities in host use may lead to novel strategies for interrupting pathogen/parasite transmission. PMID:26064562

  17. Sex-Related Differences in GI Disorders.

    PubMed

    Prusator, Dawn K; Chang, Lin

    2017-02-24

    Epidemiological studies indicate sex-related differences among functional gastrointestinal disorders (FGIDs) wherein females are more likely to receive a diagnosis than their male counterparts. However, the mechanism by which females exhibit an increased vulnerability for development of these pathophysiologies remains largely unknown, and therapeutic treatments are limited. The current chapter focuses on clinical research outlining our current knowledge of factors that contribute to the female predominance among FGID patients such as the menstrual cycle and sex hormones. In addition, we will discuss progress in preclinical research, including animal models, which serve as valuable tools for the investigation of the development and long term manifestation of symptoms observed within the patient population. Although much progress has been made, additional longitudinal studies in both clinical and preclinical research are necessary to identify more specific mechanisms underlying sex-related differences in FGIDs as well as targets for improved therapeutic approaches.

  18. Morphometric sexing of Northwest Atlantic Roseate Terns

    USGS Publications Warehouse

    Palestis, Brian G.; Nisbet, Ian C.T.; Hatch, Jeremy J.; Szczys, Patricia; Spendelow, Jeffrey A.

    2012-01-01

    A difficulty in the study of monomorphic species is the inability of observers to visually distinguish females from males. Based on a sample of 745 known-sex birds nesting at Bird Island, MA, USA, a discriminant function analysis (DFA) was used to sex Roseate Terns (Sterna dougallii) of the Northwest Atlantic population using morphological measurements. DFA using only the total length of the head (including the bill) correctly identified the sex of approximately 86% of the terns, which increased to 88% if both members of a pair were measured. Including additional measurements increased these percentages slightly, to 87% and 90%, respectively. These levels of accuracy are generally higher than those reported for other species of terns. Because female-female pairs are frequent in this population, one cannot assume that the member of a pair with the larger head is a male, and additional discriminant functions were developed to help separate female-female from male-female pairs.

  19. Sex differences in anxiety and emotional behavior

    PubMed Central

    Donner, Nina C.; Lowry, Christopher A.

    2013-01-01

    Research has elucidated causal links between stress exposure and the development of anxiety disorders, but due to the limited use of female or sex-comparative animal models, little is known about the mechanisms underlying sex differences in those disorders. This is despite an overwhelming wealth of evidence from the clinical literature that the prevalence of anxiety disorders is about twice as high in women compared to men, in addition to gender differences in severity and treatment efficacy. We here review human gender differences in generalized anxiety disorder, panic disorder, posttraumatic stress disorder and anxiety-relevant biological functions, discuss the limitations of classic conflict anxiety tests to measure naturally occurring sex differences in anxiety-like behaviors, describe sex-dependent manifestation of anxiety states after gestational, neonatal, or adolescent stressors, and present animal models of chronic anxiety states induced by acute or chronic stressors during adulthood. Potential mechanisms underlying sex differences in stress-related anxiety states include emerging evidence supporting the existence of two anatomically and functionally distinct serotonergic circuits that are related to the modulation of conflict anxiety and panic-like anxiety, respectively. We discuss how these serotonergic circuits may be controlled by reproductive steroid hormone-dependent modulation of crfr1 and crfr2 expression in the midbrain dorsal raphe nucleus and by estrous stage-dependent alterations of γ-aminobutyric acid (GABAergic) neurotransmission in the periaqueductal gray, ultimately leading to sex differences in emotional behavior. PMID:23588380

  20. Maladaptive sex ratio adjustment by a sex-changing shrimp in selective-fishing environments.

    PubMed

    Chiba, Susumu; Yoshino, Kenji; Kanaiwa, Minoru; Kawajiri, Toshifumi; Goshima, Seiji

    2013-05-01

    1. Selective harvesting is acknowledged as a serious concern in efforts to conserve wild animal populations. In fisheries, most studies have focused on gradual and directional changes in the life-history traits of target species. While such changes represent the ultimate response of harvested animals, it is also well known that the life history of target species plastically alters with harvesting. However, research on the adaptive significance of these types of condition-dependent changes has been limited. 2. We explored the adaptive significance of annual changes in the age at sex-change of the protandrous (male-first) hermaphroditic shrimp and examined how selective harvesting affects life-history variation, by conducting field observations across 13 years and a controlled laboratory experiment. In addition, we considered whether plastic responses by the shrimp would be favourable, negligible or negative with respect to the conservation of fishery resources. 3. The age at sex-change and the population structure of the shrimp fluctuated between years during the study period. The results of the field observations and laboratory experiment both indicated that the shrimp could plastically change the timing of sex-change in accordance with the age structure of the population. These findings provide the first concrete evidence of adult sex ratio adjustment by pandalid shrimp, a group that has been treated as a model in the sex allocation theory. 4. The sex ratio adjustment by the shrimp did not always seem to be sufficient, however, as the supplement of females is restricted by their annual somatic growth rate. In addition, adjusted sex ratios are further skewed by the unintentional female-selectivity of fishing activity prior to the breeding season, indicating that the occurrence of males that have postponed sex-change causes sex ratio adjustment to become unfavourable. 5. We conclude that the plastic responses of harvested animals in selective fishing environments

  1. Sex determination in mythology and history.

    PubMed

    Mittwoch, Ursula

    2005-02-01

    The history of ideas on how the sexes became divided spans at least three thousand years. The biblical account of the origin of Eve, and the opinions of the philosophers of classical Greece, have unexpected bearings on present-day ideas. The scientific study of sex determination can be said to have begun in the 17th century with the discovery of spermatozoa, but the origin and function of the "spermatic animalcules" eluded investigators until 1841. The mammalian egg was discovered in 1827, and in the last quarter of the century fertilization was observed. The view current at that time, that sex determination was under environmental control, gave way to the idea of chromosomal determination in the first quarter of the 20th century. The study of human and other mammalian chromosomes during the third quarter of the century, and the discovery of sex-chromosome abnormalities, emphasized the importance of the Y chromosome for male sex determination. The last quarter of the century witnessed a hunt for the "testis-determining" gene, thought to be responsible for the differentiation of Sertoli cells, and culminating in the isolation of SRY (Sry in the mouse). However, an increasing number of additional genes and growth factors were found to be required for the establishment of male sex. During the same period evidence emerged that male development was accompanied by enhanced growth, both of gonads and whole embryos. An unexpected finding was the demonstration of temperature-dependent sex determination in reptiles. With the advent of the 21st century, it was shown that Sry induces cell proliferation in fetal mouse gonads, and it has been suggested that male sex differentiation in mammals requires a higher metabolic rate. These insights could lead to a better understanding and improved treatment of abnormalities of sexual development.

  2. AIDS and sex tourism.

    PubMed

    Herold, E S; Van Kerkwijk, C

    1992-01-01

    Tourists traveling internationally lower their inhibitions and take greater risks than they would typically in their home cultures. Loneliness, boredom, and a sense of freedom contribute to this behavioral change. Some tourists travel internationally in search of sexual gratification. This motivation may be actively conscious or subconscious to the traveler. Billed as romantic with great natural beauty, Thailand, the Philippines, Brazil, the Dominican Republic, and Kenya are popular destinations of tourists seeking sex. The Netherlands and countries in eastern Europe are also popular. With most initial cases of HIV infection in Europe having histories of international travel, mass tourism is a major factor in the international transmission of AIDS. While abroad, tourists have sex with casual partners, sex workers, and/or other tourists. Far from all tourists, however, carry and consistently use condoms with these partners. One study found female and non white travelers to be less likely than Whites and males to carry condoms. The risk of HIV infection increases in circumstances where condoms are not readily available in the host country and/or are of poor quality. Regarding actual condom use, a study found only 34% of sex tourists from Switzerland to consistently use condoms while abroad. 28% of men in an STD clinic in Melbourne, Australia, reported consistent condom use in sexual relations while traveling in Asia; STDs were identified in 73% of men examined. The few studies of tourists suggest that a significant proportion engage in risky behavior while traveling. HIV prevalence is rapidly increasing in countries known as destinations for sex tourism. High infection rates are especially evident among teenage sex workers in Thailand. Simply documenting the prevalence of risky behavior among sex tourists will not suffice. More research is needed on travelers and AIDS with particular attention upon the motivating factors supporting persistent high-risk behavior.

  3. The role of sex chromosomes in sexual dimorphism: discordance between molecular and phenotypic data.

    PubMed

    Dean, R; Mank, J E

    2014-07-01

    In addition to initial sex determination, genes on the sex chromosomes are theorized to play a particularly important role in phenotypic differences between males and females. Sex chromosomes in many species display molecular signatures consistent with these theoretical predictions, particularly through sex-specific gene expression. However, the phenotypic implications of this molecular signature are unresolved, and the role of the sex chromosomes in quantitative genetic studies of phenotypic sex differences is largely equivocal. In this article, we examine molecular and phenotypic data in the light of theoretical predictions about masculinization and feminization of the sex chromosomes. Additionally, we discuss the role of genetic and regulatory complexities in the genome–phenotype relationship, and ultimately how these affect the overall role of the sex chromosomes in sex differences.

  4. Sex steroids and the dentate gyrus.

    PubMed

    Hajszan, Tibor; Milner, Teresa A; Leranth, Csaba

    2007-01-01

    In the late 1980s, the finding that the dentate gyrus contains more granule cells in the male than in the female of certain mouse strains provided the first indication that the dentate gyrus is a significant target for the effects of sex steroids during development. Gonadal hormones also play a crucial role in shaping the function and morphology of the adult brain. Besides reproduction-related processes, sex steroids participate in higher brain operations such as cognition and mood, in which the hippocampus is a critical mediator. Being part of the hippocampal formation, the dentate gyrus is naturally involved in these mechanisms and as such, this structure is also a critical target for the activational effects of sex steroids. These activational effects are the results of three major types of steroid-mediated actions. Sex steroids modulate the function of dentate neurons under normal conditions. In addition, recent research suggests that hormone-induced cellular plasticity may play a larger role than previously thought, particularly in the dentate gyrus. Specifically, the regulation of dentate gyrus neurogenesis and synaptic remodeling by sex steroids received increasing attention lately. Finally, the dentate gyrus is influenced by gonadal hormones in the context of cellular injury, and the work in this area demonstrates that gonadal hormones have neuroprotective potential. The expression of estrogen, progestin, and androgen receptors in the dentate gyrus suggests that sex steroids, which could be of gonadal origin and/or synthesized locally in the dentate gyrus, may act directly on dentate cells. In addition, gonadal hormones could also influence the dentate gyrus indirectly, by subcortical hormone-sensitive structures such as the cholinergic septohippocampal system. Importantly, these three sex steroid-related themes, functional effects in the normal dentate gyrus, mechanisms involving neurogenesis and synaptic remodeling, as well as neuroprotection, have

  5. Crack, crack house sex, and HIV risk.

    PubMed

    Inciardi, J A

    1995-06-01

    Limited attention has been focused on HIV risk behaviors of crack smokers and their sex partners, yet there is evidence that the crack house and the crack-using life-style may be playing significant roles in the transmission of HIV and other sexually transmitted diseases. The purposes of this research were to study the attributes and patterns of "sex for crack" exchanges, particularly those that occurred in crack houses, and to assess their potential impact on the spread of HIV. Structured interviews were conducted with 17 men and 35 women in Miami, Florida, who were regular users of crack and who had exchanged sex for crack (or for money to buy crack) during the past 30 days. In addition, participant observation was conducted in 8 Miami crack houses. Interview and observational data suggest that individuals who exchange sex for crack do so with considerable frequency, and through a variety of sexual activities. Systematic data indicated that almost a third of the men and 89% of the women had had 100 or more sex partners during the 30-day period prior to study recruitment. Not only were sexual activities anonymous, extremely frequent, varied, uninhibited (often undertaken in public areas of crack houses), and with multiple partners but, in addition, condoms were not used during the majority of contacts. Of the 37 subjects who were tested for HIV and received their test results 31% of the men and 21% of the women were HIV seropositive.

  6. What Asexuality Contributes to the Same-Sex Marriage Discussion.

    PubMed

    Scherrer, Kristin S

    2010-01-01

    While same-sex marriage debates have captured public attention, it is but one component of a broader discussion regarding the role of marriage in a changing society. To inform this discussion, I draw on qualitative, Internet survey data from 102 self-identified asexual individuals. I find that asexual relationships are complicated and nuanced in ways that have implications for a GLBTQ political agenda, including same-sex marriage recognition. In addition, findings indicate that assumptions of sex and sexuality in relationships are problematic and that present language for describing relationships is limiting. Findings suggest a social justice agenda for marginalized sexualities should be broader in scope than same-sex marriage.

  7. Anolis sex chromosomes are derived from a single ancestral pair.

    PubMed

    Gamble, Tony; Geneva, Anthony J; Glor, Richard E; Zarkower, David

    2014-04-01

    To explain the frequency and distribution of heteromorphic sex chromosomes in the lizard genus Anolis, we compared the relative roles of sex chromosome conservation versus turnover of sex-determining mechanisms. We used model-based comparative methods to reconstruct karyotype evolution and the presence of heteromorphic sex chromosomes onto a newly generated Anolis phylogeny. We found that heteromorphic sex chromosomes evolved multiple times in the genus. Fluorescent in situ hybridization (FISH) of repetitive DNA showed variable rates of Y chromosome degeneration among Anolis species and identified previously undetected, homomorphic sex chromosomes in two species. We confirmed homology of sex chromosomes in the genus by performing FISH of an X-linked bacterial artificial chromosome (BAC) and quantitative PCR of X-linked genes in multiple Anolis species sampled across the phylogeny. Taken together, these results are consistent with long-term conservation of sex chromosomes in the group. Our results pave the way to address additional questions related to Anolis sex chromosome evolution and describe a conceptual framework that can be used to evaluate the origins and evolution of heteromorphic sex chromosomes in other clades.

  8. Turnover of Sex Chromosomes in Celebensis Group Medaka Fishes.

    PubMed

    Myosho, Taijun; Takehana, Yusuke; Hamaguchi, Satoshi; Sakaizumi, Mitsuru

    2015-10-23

    Sex chromosomes and the sex-determining (SD) gene are variable in vertebrates. In particular, medaka fishes in the genus Oryzias show an extremely large diversity in sex chromosomes and the SD gene, providing a good model to study the evolutionary process by which they turnover. Here, we investigated the sex determination system and sex chromosomes in six celebensis group species. Our sex-linkage analysis demonstrated that all species had an XX-XY sex determination system, and that the Oryzias marmoratus and O. profundicola sex chromosomes were homologous to O. latipes linkage group (LG) 10, while those of the other four species, O. celebensis, O. matanensis, O. wolasi, and O. woworae, were homologous to O. latipes LG 24. The phylogenetic relationship suggested a turnover of the sex chromosomes from O. latipes LG 24 to LG 10 within this group. Six sex-linkage maps showed that the former two and the latter four species shared a common SD locus, respectively, suggesting that the LG 24 acquired the SD function in a common ancestor of the celebensis group, and that the LG 10 SD function appeared in a common ancestor of O. marmoratus and O. profundicola after the divergence of O. matanensis. Additionally, fine mapping and association analysis in the former two species revealed that Sox3 on the Y chromosome is a prime candidate for the SD gene, and that the Y-specific 430-bp insertion might be involved in its SD function.

  9. Anolis sex chromosomes are derived from a single ancestral pair

    PubMed Central

    Gamble, Tony; Geneva, Anthony J.; Glor, Richard E.; Zarkower, David

    2014-01-01

    To explain the frequency and distribution of heteromorphic sex chromosomes in the lizard genus Anolis we compared the relative roles of sex chromosome conservation vs. turnover of sex determining mechanisms. We used model based comparative methods to reconstruct karyotype evolution and the presence of heteromorphic sex chromosomes onto a newly generated Anolis phylogeny. We found that heteromorphic sex chromosomes evolved multiple times in the genus. Fluorescent in situ hybridization (FISH) of repetitive DNA showed variable rates of Y chromosome degeneration among Anolis species and identified previously undetected, homomorphic sex chromosomes in two species. We confirmed homology of sex chromosomes in the genus by performing FISH of an X-linked BAC and qPCR of X-linked genes in multiple Anolis species sampled across the phylogeny. Taken together, these results are consistent with long-term conservation of sex chromosomes in the group. Our results pave the way to address additional questions related to Anolis sex chromosome evolution and describe a conceptual framework that can be used to evaluate the origins and evolution of heteromorphic sex chromosomes in other clades. PMID:24279795

  10. Sex Trafficking of Minors.

    PubMed

    Moore, Jessica L; Kaplan, Dana M; Barron, Christine E

    2017-04-01

    Sex trafficking is an increasingly recognized global health crisis affecting every country and region in the world. Domestic minor sex trafficking is a subset of commercial sexual exploitation of children, defined as engagement of minors (<18 years of age) in sexual acts for items of value (eg, food, shelter, drugs, money) involving children victimized within US borders. These involved youth are at risk for serious immediate and long-term physical and mental health consequences. Continued efforts are needed to improve preventive efforts, identification, screening, appropriate interventions, and subsequent resource provision for victimized and high-risk youth.

  11. How sex became gender.

    PubMed

    Nye, Robert A

    2010-01-01

    This article argues that "sex" which had been commonly assumed in the West to refer to a permanent set of biological and behavioural traits particular to men and women, is gradually being replaced in general usage by "gender." Though feminist theorists attempted to attach a constructivist meaning to gender, a generation of developmental theorists, clinicians and analysts has imbued the term with the determinism and biological qualities formerly ascribed to "sex." The triumph of this materialist conception of gender is not assured, but it threatens our ability to think about gender identity as a historically-constructed category.

  12. Sex Therapy and Mastectomy

    ERIC Educational Resources Information Center

    Witkin, Mildred Hope

    1975-01-01

    Because the emotional trauma associated with a mastectomy exceeds the physical trauma, the recovery of the woman is greatly affected by the response of her husband or lover. Sex therapy, therefore, involves the couple. The approach described is aimed at assisting the couple to confront and integrate the mastectomy experience. (Author)

  13. Sex Education and Ideals

    ERIC Educational Resources Information Center

    de Ruyter, Doret J.; Spiecker, Ben

    2008-01-01

    This article argues that sex education should include sexual ideals. Sexual ideals are divided into sexual ideals in the strict sense and sexual ideals in the broad sense. It is argued that ideals that refer to the context that is deemed to be most ideal for the gratification of sexual ideals in the strict sense are rightfully called sexual…

  14. Sex And People.

    ERIC Educational Resources Information Center

    Jones, Kenneth L.; And Others

    This textbook for the college student emphasizes human sexuality as a part of the whole human life experience and contains a balance of biological, psychological, and sociological material. In 16 chapters the following topics are covered: (1) sex and society; (2) historical and cultural perspectives; (3) glandular control of sexual physiology; (4)…

  15. Sex Differences in Achievement.

    ERIC Educational Resources Information Center

    Cross, David

    1983-01-01

    Evaluates the commonly held idea that girls are better language learners than boys. Results indicate that boys are not weaker in any of the language skill areas tested. Recommends that future research concentrate on the sex and image of the teacher. (EKN)

  16. Sex, Technology and Morality.

    ERIC Educational Resources Information Center

    Case, Verna; And Others

    1986-01-01

    Provides an overview of the course "Sex, Technology, and Morality" which focuses on the human reproductive process and examines the advances in reproductive technology. The course emphasizes the social, political, and ethical implications of actual and possible technologies associated with human reproduction. (ML)

  17. Teenage sex talk.

    PubMed

    Hadley, A

    Although an international study recently revealed that 87% of the UK's teenage mothers are unmarried, the highest figure in the world according to Alan Guttmacher Institute data of 1998, the teen conception rate in the country has declined considerably over the past 25 years and the number of teen mothers has been almost halved. Teens, as well as couples in other age groups, are increasingly cohabiting outside of marriage rather than getting married; more than two-thirds of babies born to teenagers are jointly registered by both parents. However, despite the decline in teenage conceptions since 1970, the UK still has one of the highest rates in Europe. The UK's real scandal is its failure to give young people the information they need to manage their sexual health. International research has proven that sexual health can be improved if societies are open about sex, accept teenage sexuality, and permit discussion about sex without embarrassment. Moreover, sex and relationships education should start at an early age, and young people should have easy access to free and confidential sex advice. Individuals under age 16 years have the right to the same degree of confidentiality as that afforded to adults. Vast potential exists for nurses to increase teenagers' use of services by removing the key obstacles which deter them from seeking advice: fears about confidentiality, lack of service publicity, and inappropriate opening times.

  18. Sex Education For Educators

    ERIC Educational Resources Information Center

    Renshaw, Domeena C.

    1973-01-01

    Currently, sex education covers the mechanics of reproduction; details of venereal disease, and birth control information. This paper argues that this field should be augmented by the inclusion of the emotionally enriching, interpersonal, and sociocultural elements of human sexuality. A fundamentally Freudian sketch of sexual development is…

  19. Sex Differences in Influenceability

    ERIC Educational Resources Information Center

    Eagly, Alice H.

    1978-01-01

    Examines the hypothesis that women are more easily influenced than men by reviewing the literature on persuasion and conformity research. Persuasion research and conformity studies not involving group pressure show scant empirical support for sex differences. For group pressure conformity research, a substantial minority of studies support the…

  20. Sex and Cognition.

    ERIC Educational Resources Information Center

    Kimura, Doreen

    This book describes the major differences between men and women in cognitive or problem-solving abilities and discusses the possible biological contributions to such differences. The book argues that sex differences in cognitive patterns and in motor skills arose out of complementary evolutionary histories of men and women and that evidence for…

  1. How Sex Attitudes Develop

    ERIC Educational Resources Information Center

    Arnstein, Helene S.

    1976-01-01

    Excerpt from "The Roots of Love" (Helene S. Arnstein, 1975). Book is concerned with feelings that are part of child's developmental stages. Included in excerpt are: genital self-discovery, masturbation, discovery of sex differences, and birth fantasies. Stresses importance of parent's feelings which are communicated to child.

  2. Sex, Courtship, and Marriage.

    ERIC Educational Resources Information Center

    Seiferth, Berniece

    The author presents an historical perspective on abortion, contraception and marriage as a prelude to an examination of changing attitudes toward sex. The article deals with the negative effects attributed to the increased incidence of early dating and early marriage of teenagers in the United States. The author also assumes positions on such…

  3. Sex differences in addiction.

    PubMed

    Becker, Jill B

    2016-12-01

    Women exhibit more rapid escalation from casual drug taking to addiction, exhibit a greater withdrawal response with abstinence, and tend to exhibit greater vulnerability than men in terms of treatment outcome. In rodents, short-term estradiol intake in female rats enhances acquisition and escalation of drug taking, motivation for drugs of abuse, and relapse-like behaviors. There is also a sex difference in the dopamine response in the nucleus accumbens. Ovariectomized female rats exhibit a smaller initial dopamine increase after cocaine treatment than castrated males. Estradiol treatment of ovariectomized female rats enhances stimulated dopamine release in the dorsolateral striatum, but not in the nucleus accumbens, resulting in a sex difference in the balance between these two dopaminergic projections. In the situation where drug-taking behavior becomes habitual, dopamine release has been reported to be enhanced in the dorsolateral striatum and attenuated in the nucleus accumbens. The sex difference in the balance between these neural systems is proposed to underlie sex differences in addiction.

  4. Sex differences in addiction

    PubMed Central

    Becker, Jill B.

    2016-01-01

    Women exhibit more rapid escalation from casual drug taking to addiction, exhibit a greater withdrawal response with abstinence, and tend to exhibit greater vulnerability than men in terms of treatment outcome. In rodents, short-term estradiol intake in female rats enhances acquisition and escalation of drug taking, motivation for drugs of abuse, and relapse-like behaviors. There is also a sex difference in the dopamine response in the nucleus accumbens. Ovariectomized female rats exhibit a smaller initial dopamine increase after cocaine treatment than castrated males. Estradiol treatment of ovariectomized female rats enhances stimulated dopamine release in the dorsolateral striatum, but not in the nucleus accumbens, resulting in a sex difference in the balance between these two dopaminergic projections. In the situation where drug-taking behavior becomes habitual, dopamine release has been reported to be enhanced in the dorsolateral striatum and attenuated in the nucleus accumbens. The sex difference in the balance between these neural systems is proposed to underlie sex differences in addiction. PMID:28179811

  5. Sex and gender differences in clinical medicine.

    PubMed

    Regitz-Zagrosek, Vera; Seeland, Ute

    2012-01-01

    Sex and gender differences in frequent diseases are more widespread than one may assume. In addition, they have significant yet frequently underestimated consequences on the daily practice of medicine, on outcomes and effects of therapies. Gender medicine is a novel medical discipline that takes into account the effects of sex and gender on the health of women and men. The major goal is to improve health and health care for both, for women as well as for men. We give in this chapter an overview on sex and gender differences in a number of clinical areas, in cardiovascular diseases, pulmonary diseases, gastroenterology and hepatology, in nephrology, autoimmune diseases, endocrinology, hematology, neurology. We discuss the preferential use of male animals in drug development, the underrepresentation of women in early and cardiovascular clinical trials, sex and gender differences in pharmacology, in pharmacokinetics and pharmacodynamics, in management and drug use. Most guidelines do not include even well-known sex and gender differences. European guidelines for the management of cardiovascular diseases in pregnancy have only recently been published. Personalized medicine cannot replace gender-based medicine. Large databases reveal that gender remains an independent risk factor after ethnicity, age, comorbidities, and scored risk factors have been taken into account. Some genetic variants carry a different risk in women and men. The sociocultural dimension of gender integrating lifestyle, environment, stress, and other variables cannot be replaced by a sum of biological parameters. Because of this prominent role of gender, clinical care algorithms must include gender-based assessment.

  6. [Sex chromosomes and meiosis].

    PubMed

    Guichaoua, M-R; Geoffroy-Siraudin, C; Tassistro, V; Ghalamoun-Slaimi, R; Perrin, J; Metzler-Guillemain, C

    2009-01-01

    Sex chromosome behaviour fundamentally differs between male and female meiosis. In oocyte, X chromosomes synapse giving a XX bivalent which is not recognizable in their morphology and behaviour from autosomal bivalents. In human male, X and Y chromosomes differ from one another in their morphology and their genetic content, leading to a limited pairing and preventing genetic recombination, excepted in homologous region PAR1. During pachytene stage of the first meiotic prophase, X and Y chromosomes undergo a progressive condensation and form a transcriptionally silenced peripheral XY body. The condensation of the XY bivalent during pachytene stage led us to describe four pachytene substages and to localize the pachytene checkpoint between substages 2 and 3. We also defined the pachytene index (PI=P1+P2/P1+P2+P3+P4) which is always less than 0.50 in normal meiosis. XY body undergoes decondensation at diplotene stage, but transcriptional inactivation of the two sex chromosomes or Meiotic Sex Chromosome Inactivation (MSCI) persists through to the end of spermatogenesis. Sex chromosome inactivation involves several proteins, some of them were now identified. Two isoforms of the HP1 protein, HP1beta and HP1gamma, are involved in the facultative heterochromatinization of the XY body, but the initiation of this process involves the phosphorylation of the protein H2AX by the kinase ATR whose recruitment depends on BRCA1. Extensive researches on the inactivation of the sex chromosomes during male meiosis will allow to a better understanding of some male infertilities.

  7. Disestablishing Sex: The Case for Released-Time Sex Education

    ERIC Educational Resources Information Center

    Glanzer, Perry L.

    2011-01-01

    Allowing nonschool organizations to provide sex education in a released-time format would disestablish state-funded sex education and give families a choice in the sex education that would be provided for their children. Released-time programs, as originally conceived and currently practiced, allow students to be released for a period of time…

  8. Sex Role Attitudes and Sex Role Stereotyping: Recent Literature.

    ERIC Educational Resources Information Center

    New Jersey Research Bulletin, 1996

    1996-01-01

    This annotated bibliography profiles 17 publications examining sex role attitudes/sex role stereotyping from the perspectives of ethnicity, gender, and age. Cited in the section on ethnicity are studies of work satisfaction/family functioning among working-class Mexican-American women and cultural variations in sex typing by students in the United…

  9. Sex-Integrated Physical Education

    ERIC Educational Resources Information Center

    Kneer, Marian E.

    1978-01-01

    Title IX requires that the practice of segregating physical education classes on the basis of sex must cease. This article offers suggestions on how to ease the transition to sex-integrated physical education programs. (Author/DS)

  10. The ABCs of Sex Ed.

    ERIC Educational Resources Information Center

    Sroka, Stephen R.

    2002-01-01

    Cites statistics on extent of sexually transmitted diseases and pregnancies among adolescents; describes ideological dispute over how to teach sex education; advocates teaching the ABCs of sex education: Abstinence, Be Monogamous, and Condoms. (PKP)

  11. Hypnotic Psychotherapy with Sex Offenders

    ERIC Educational Resources Information Center

    Moseley, Sullivan; Briggs, Wanda P.; Magnus, Virginia

    2005-01-01

    The authors review the literature on the prevalence of sex offenders; multiple treatment modalities; and implications of the use of hypnotic psychotherapy, coupled with cognitive behavioral treatment programs, for treating sex offenders. (Contains 2 tables.)

  12. Abnormal human sex chromosome constitutions

    SciTech Connect

    1993-12-31

    Chapter 22, discusses abnormal human sex chromosome constitution. Aneuploidy of X chromosomes with a female phenotype, sex chromosome aneuploidy with a male phenotype, and various abnormalities in X chromosome behavior are described. 31 refs., 2 figs.

  13. SHBG (Sex Hormone Binding Globulin)

    MedlinePlus

    ... as: Testosterone-estrogen Binding Globulin; TeBG Formal name: Sex Hormone Binding Globulin Related tests: Testosterone , Free Testosterone, ... I should know? How is it used? The sex hormone binding globulin (SHBG) test may be used ...

  14. Sex Differences and Sex Steroids in Lung Health and Disease

    PubMed Central

    Townsend, Elizabeth A.; Miller, Virginia M.

    2012-01-01

    Sex differences in the biology of different organ systems and the influence of sex hormones in modulating health and disease are increasingly relevant in clinical and research areas. Although work has focused on sex differences and sex hormones in cardiovascular, musculoskeletal, and neuronal systems, there is now increasing clinical evidence for sex differences in incidence, morbidity, and mortality of lung diseases including allergic diseases (such as asthma), chronic obstructive pulmonary disease, pulmonary fibrosis, lung cancer, as well as pulmonary hypertension. Whether such differences are inherent and/or whether sex steroids play a role in modulating these differences is currently under investigation. The purpose of this review is to define sex differences in lung structure/function under normal and specific disease states, with exploration of whether and how sex hormone signaling mechanisms may explain these clinical observations. Focusing on adult age groups, the review addresses the following: 1) inherent sex differences in lung anatomy and physiology; 2) the importance of certain time points in life such as puberty, pregnancy, menopause, and aging; 3) expression and signaling of sex steroid receptors under normal vs. disease states; 4) potential interplay between different sex steroids; 5) the question of whether sex steroids are beneficial or detrimental to the lung; and 6) the potential use of sex steroid signaling as biomarkers and therapeutic avenues in lung diseases. The importance of focusing on sex differences and sex steroids in the lung lies in the increasing incidence of lung diseases in women and the need to address lung diseases across the life span. PMID:22240244

  15. ECOLOGICAL AND EVOLUTIONARY APPLICATIONS FOR ENVIRONMENTAL SEX REVERSAL OF FISH.

    PubMed

    Mcnair, Alistair; Lokman, P Mark; Closs, Gerard P; Nakagawa, Shinichi

    2015-03-01

    Environmental sex reversal (ESR), which results in a mismatch between genotypic and phenotypic sex, is well documented in numerous fish species and may be induced by chemical exposure. Historically, research involving piscine ESR has been carried out with a view to improving profitability in aquaculture or to elucidate the processes governing sex determination and sexual differentiation. However, recent studies in evolution and ecology suggest research on ESR now has much wider applications and ramifications. We begin with an overview of ESR in fish and a brief review of the traditional applications thereof. We then discuss ESR and its potential demographic consequences in wild populations. Theory even suggests sex-reversed fish may be purposefully released to manipulate population dynamics. We suggest new research directions that may prove fruitful in understanding how ESR at the individual level translates to population-level processes. In the latter portion of the review we focus on evolutionary applications of ESR. Sex-reversal studies from the aquaculture literature provide insight in to the evolvability of determinants of sexual phenotype. Additionally, induced sex reversal can provide information about the evolution of sex chromosomes and sex-linked traits. Recently, naturally occurring ESR has been implicated as a mechanism contributing to the evolution of sex chromosomes.

  16. Single Sex Education. WEEA Digest.

    ERIC Educational Resources Information Center

    Pollard, Diane S.

    Title IX of the Educational Amendments of 1972 prohibits discrimination on the basis of sex in educational institutions that receive federal financial assistance. This digest focuses on the theme of single-sex education. Articles featured in this issue include: (1) "Single-Sex Education" (Diane S. Pollard); (2) "A Legal Framework for Single-Sex…

  17. Hepatitis C: Sex and Sexuality

    MedlinePlus

    ... or not at all. Decrease the number of people you have sex with. Tell your sex partner(s) that you have ... from the VA National HIV/AIDS Program Safer Sex Resources A list of Web sites that offer information to help people make responsible sexual choices. return to top CONNECT ...

  18. Sex Stereotyping by Tomorrow's Executives.

    ERIC Educational Resources Information Center

    Kovach, Kenneth A.

    1985-01-01

    Describes a study in which 512 college seniors were surveyed to see if members of one sex would implicitly stereotype by sex to a greater degree than the other. Questions concerned job/home conflicts and selection and promotion. Results indicated that men and women are equally guilty of sex stereotyping, which works against women in the workplace.…

  19. Sex Education with Young Children.

    ERIC Educational Resources Information Center

    Koblinsky, Sally; And Others

    1980-01-01

    Discusses guidelines (developed by the Oregon State University Early Childhood Sex Education Project) for developing teacher-parent cooperation in providing sex education to young children. The guidelines concern how to talk about body differences and body functions; how to deal with masturbation, sex play and obscene language; and how to involve…

  20. Age and sex or gender (sex/gender) and HIV vaccine preparedness.

    PubMed

    Dhalla, Shayesta

    2015-10-29

    An examination of age and sex or gender (sex/gender) in HIV vaccine preparedness studies can contribute to an understanding of these demographic variables in preparation for actual HIV vaccine trials. In this descriptive review, age and sex or gender (sex/gender) were examined in relation to willingness to participate (WTP) and retention in an HIV vaccine trial. Twenty-five articles were retrieved from the Organization for Economic Co-operation and Development (OECD) countries and 28 articles were retrieved from the non-OECD countries. In US studies that involved mainly white MSM, older men were more likely to be WTP in a hypothetical HIV vaccine trial and more likely to be retained than younger men. In most OECD studies, sex/gender was not associated with WTP in a hypothetical HIV vaccine trial, while females were more likely to be retained in most studies. Largely, age was not associated with WTP in the non-OECD countries, but the results on sex/gender were more variable. The relationship between adolescent or adult WTP in hypothetical HIV vaccine trials in South Africa did not appear to be modified by high school student status. In addition, more studies in discordant couples in the context of HIV vaccine preparedness could be conducted to examine gender roles and inequalities in preparation for HIV vaccine trials.

  1. Beyond the 'safe sex' propaganda.

    PubMed

    Hadzic, Maja; Khajehei, Marjan

    2010-01-01

    In this paper, we discuss sexual relationships among teenagers, the related issues, and suggest addressing the issues through effective education programs for both teenagers and their parents. We also discuss the main issues resulting from initiation of sexual relationship during adolescence such as unwanted pregnancy, maternal mortality, abortion, sexually transmitted diseases and damaged mental health. In addition, we highlight the lack of adequate sex education in teenagers and emphasize on the negative influence of TV programs and the harmful effects of dysfunctional families. Moreover, this article proposes equipping teenagers with knowledge that will help them understand not only physical but also emotional, social, and mental dynamics of sexual relationships. We believe that this approach would intervene much earlier in their life, help teenagers make healthy decision and minimize negative consequences of their personal choices.

  2. Sex Steroid Actions in Male Bone

    PubMed Central

    Laurent, Michaël R.; Claessens, Frank; Gielen, Evelien; Lagerquist, Marie K.; Vandenput, Liesbeth; Börjesson, Anna E.; Ohlsson, Claes

    2014-01-01

    Sex steroids are chief regulators of gender differences in the skeleton, and male gender is one of the strongest protective factors against osteoporotic fractures. This advantage in bone strength relies mainly on greater cortical bone expansion during pubertal peak bone mass acquisition and superior skeletal maintenance during aging. During both these phases, estrogens acting via estrogen receptor-α in osteoblast lineage cells are crucial for male cortical and trabecular bone, as evident from conditional genetic mouse models, epidemiological studies, rare genetic conditions, genome-wide meta-analyses, and recent interventional trials. Genetic mouse models have also demonstrated a direct role for androgens independent of aromatization on trabecular bone via the androgen receptor in osteoblasts and osteocytes, although the target cell for their key effects on periosteal bone formation remains elusive. Low serum estradiol predicts incident fractures, but the highest risk occurs in men with additionally low T and high SHBG. Still, the possible clinical utility of serum sex steroids for fracture prediction is unknown. It is likely that sex steroid actions on male bone metabolism rely also on extraskeletal mechanisms and cross talk with other signaling pathways. We propose that estrogens influence fracture risk in aging men via direct effects on bone, whereas androgens exert an additional antifracture effect mainly via extraskeletal parameters such as muscle mass and propensity to fall. Given the demographic trends of increased longevity and consequent rise of osteoporosis, an increased understanding of how sex steroids influence male bone health remains a high research priority. PMID:25202834

  3. Seeking sex partners through the internet and mobile phone applications among men who have sex with men in Taiwan.

    PubMed

    Ko, Nai-Ying; Tseng, Po-Chia; Huang, Yu-Chao; Chen, Yen-Chin; Hsu, Su-Ting

    2016-07-01

    It has become popular for men who have sex with men (MSM) to use mobile-phone geosocial networking applications (mobile apps) to find sex partners. A cross-sectional online survey was conducted in Taiwan to compare the sexual and substance-use behaviors of MSM seeking sex partners through the internet and mobile apps. Of the 1060 participants, 65.8% used the internet via computer and 37.7% used a mobile app to find sexual partners, while 30.3% used recreational drugs or alcohol in the previous 6 months. MSM who exclusively used mobile apps to seek sex partners were significantly more likely than MSM seeking sex via computer to be older, to have used recreational drugs or alcohol, and to have sex with HIV-positive partners. Additionally, using mobile apps to seek sex partners was significantly associated with having sex with online partners through either mobile apps or computer-based internet use (adjusted odds ratio (AOR), 7.12 [3.87-13.11]), self-reporting as HIV-positive (AOR, 2.24 [1.12-4.12]), using recreational drugs (AOR, 1.67 [1.21-2.32]), having disclosed HIV status to sexual partners (AOR, 1.44 [1.03-2.02]), and having sex with HIV-positive partners (AOR, 1.81 [1.06-3.10]). In conclusion, the mobile apps may serve as a feasible platform for HIV-positive MSM to find other HIV-positive partners.

  4. Sex therapy and mastectomy.

    PubMed

    Witkin, M H

    1975-01-01

    Because the emotional trauma associated with a mastectomy exceeds the physical trauma, the recovery of the woman is greatly affected by the response of her husband or lover. Sex therapy, therefore, involves the couple. The approach described here is aimed at assisting the couple to confront and intergrate the mastectomy experience. The use of a prosthesis is discouraged during intercourse because it delays such confrontation; certain sex therapy exercises (body imagery and sensate focus) are usually recommended because they facilitate confrontation and acceptance. These, modified for the circumstances, are described. It is suggested that intercourse be attempted as early as possible, and that if physical weakness or psychological trepidation intervenes, the physical desire and caring of the husband be expressed nonetheless. The "professional" attitudes that psychotherapy is always indicated for mastectomy patients and that the proper role of the husband is matter-of-fact denial are rejected; emphasis is placed on the beneficial consequences of sharing of all emotions.

  5. Sex ratio and spatial distribution of male and female Antennaria dioica (Asteraceae) plants

    NASA Astrophysics Data System (ADS)

    Varga, Sandra; Kytöviita, Minna-Maarit

    2011-09-01

    Sex ratio, sex spatial distribution and sexual dimorphism in reproduction and arbuscular mycorrhizal colonisation were investigated in the dioecious clonal plant Antennaria dioica (Asteraceae). Plants were monitored for five consecutive years in six study plots in Oulanka, northern Finland. Sex ratio, spatial distribution of sexes, flowering frequency, number of floral shoots and the number and weight of inflorescences were recorded. In addition, intensity of mycorrhizal fungi in the roots was assessed. Both sexes flowered each year with a similar frequency, but the overall genet sex ratio was strongly female-biased. The bivariate Ripley's analysis of the sex distribution showed that within most plots sexes were randomly distributed except for one plot. Sexual dimorphism was expressed as larger floral and inflorescence production and heavier inflorescences in males. In addition, the roots of both sexes were colonised to a similar extent by arbuscular mycorrhizal fungi. The female sex-biased flowering ratios reported are not consistent among years and cannot be explained in terms of spatial segregation of the sexes or sex lability. The possible reasons for the female-biased sex ratio are discussed.

  6. Sex differences in brain epigenetics.

    PubMed

    Menger, Yannick; Bettscheider, Marc; Murgatroyd, Chris; Spengler, Dietmar

    2010-12-01

    Sexual differentiation of the brain takes place during a perinatal-sensitive time window as a result of gonadal hormone-induced activational and organizational effects on neuronal substrates. Increasing evidence suggests that epigenetic mechanisms can contribute to the establishment and maintenance of some aspects of these processes, and that these epigenetic mechanisms may themselves be under the control of sex hormones. Epigenetic programming of neuroendocrine and behavioral phenotypes frequently occurs sex specifically, pointing to sex differences in brain epigenetics as a possible determinant. Understanding how sex-specific epigenomes and sex-biased responses to environmental cues contribute to the development of brain diseases might provide new insights for epigenetic therapy.

  7. The many costs of sex.

    PubMed

    Lehtonen, Jussi; Jennions, Michael D; Kokko, Hanna

    2012-03-01

    Explaining the evolution of sex is challenging for biologists. A 'twofold cost' compared with asexual reproduction is often quoted. If a cost of this magnitude exists, the benefits of sex must be large for it to have evolved and be maintained. Focusing on benefits can be misleading, as this sidelines important questions about the cost of sex: what is the source of the twofold cost: males, genome dilution or both? Does the cost deviate from twofold? What other factors make sex costly? How should the costs of sex be empirically measured? The total cost of sex and how it varies in different contexts must be known to determine the benefits needed to account for the origin and maintenance of sex.

  8. Oral sex and oropharyngeal cancer

    PubMed Central

    Nguyen, Nam P.; Nguyen, Ly M.; Thomas, Sroka; Hong-Ly, Bevan; Chi, Alexander; Vos, Paul; Karlsson, Ulf; Vinh-Hung, Vincent

    2016-01-01

    Abstract Background: We aimed to study the prevalence of oral sex and its possible association with human papillomavirus (HPV) 16 infection in the development of oropharyngeal cancer in the US population for possible prevention. Methods: We conduct a systemic review on the prevalence of oral sex among Americans among different age groups, the prevalence of HPV 16 infection reported in oropharyngeal cancer, and correlation between oral sex and oropharyngeal cancer. Results: Oral sex is prevalent among adolescents and sexually active adults. Sixty percent of oropharyngeal cancer reported in the United States is associated with HPV 16 infections. Individuals who practiced oral sex with multiple partners are at risk for developing oropharyngeal cancer and need to be informed about practicing safe sex or getting vaccination. Conclusion: Family physicians will play a key role in prevention and educating the public about the risk of oral sex. PMID:27428229

  9. Sex steroids and bone.

    PubMed

    Manolagas, S C; Kousteni, S; Jilka, R L

    2002-01-01

    The adult skeleton is periodically remodeled by temporary anatomic structures that comprise juxtaposed osteoclast and osteoblast teams and replace old bone with new. Estrogens and androgens slow the rate of bone remodeling and protect against bone loss. Conversely, loss of estrogen leads to increased rate of remodeling and tilts the balance between bone resorption and formation in favor of the former. Studies from our group during the last 10 years have elucidated that estrogens and androgens decrease the number of remodeling cycles by attenuating the birth rate of osteoclasts and osteoblasts from their respective progenitors. These effects result, in part, from the transcriptional regulation of genes responsible for osteoclastogenesis and mesenchymal cell replication and/or differentiation and are exerted through interactions of the ligand-activated receptors with other transcription factors. However, increased remodeling alone cannot explain why loss of sex steroids tilts the balance of resorption and formation in favor of the former. Estrogens and androgens also exert effects on the lifespan of mature bone cells: pro-apoptotic effects on osteoclasts but anti-apoptotic effects on osteoblasts and osteocytes. These latter effects stem from a heretofore unexpected function of the classical "nuclear" sex steroid receptors outside the nucleus and result from activation of a Src/Shc/extracellular signal-regulated kinase signal transduction pathway probably within preassembled scaffolds called caveolae. Strikingly, estrogen receptor (ER) alpha or beta or the androgen receptor can transmit anti-apoptotic signals with similar efficiency, irrespective of whether the ligand is an estrogen or an androgen. More importantly, these nongenotropic, sex-nonspecific actions are mediated by the ligand-binding domain of the receptor and can be functionally dissociated from transcriptional activity with synthetic ligands. Taken together, these lines of evidence strongly suggest that

  10. Sex Determination, Sex Chromosomes, and Karyotype Evolution in Insects.

    PubMed

    Blackmon, Heath; Ross, Laura; Bachtrog, Doris

    2017-01-01

    Insects harbor a tremendous diversity of sex determining mechanisms both within and between groups. For example, in some orders such as Hymenoptera, all members are haplodiploid, whereas Diptera contain species with homomorphic as well as male and female heterogametic sex chromosome systems or paternal genome elimination. We have established a large database on karyotypes and sex chromosomes in insects, containing information on over 13000 species covering 29 orders of insects. This database constitutes a unique starting point to report phylogenetic patterns on the distribution of sex determination mechanisms, sex chromosomes, and karyotypes among insects and allows us to test general theories on the evolutionary dynamics of karyotypes, sex chromosomes, and sex determination systems in a comparative framework. Phylogenetic analysis reveals that male heterogamety is the ancestral mode of sex determination in insects, and transitions to female heterogamety are extremely rare. Many insect orders harbor species with complex sex chromosomes, and gains and losses of the sex-limited chromosome are frequent in some groups. Haplodiploidy originated several times within insects, and parthenogenesis is rare but evolves frequently. Providing a single source to electronically access data previously distributed among more than 500 articles and books will not only accelerate analyses of the assembled data, but also provide a unique resource to guide research on which taxa are likely to be informative to address specific questions, for example, for genome sequencing projects or large-scale comparative studies.

  11. "Sex Hormones" in Secondary School Biology Textbooks

    ERIC Educational Resources Information Center

    Nehm, Ross H.; Young, Rebecca

    2008-01-01

    This study explores the extent to which the term "sex hormone" is used in science textbooks, and whether the use of the term "sex hormone" is associated with pre-empirical concepts of sex dualism, in particular the misconceptions that these so-called "sex hormones" are sex specific and restricted to sex-related physiological functioning. We found…

  12. Legal recognition of same-sex couples and family formation.

    PubMed

    Trandafir, Mircea

    2015-02-01

    It has long been debated how legalizing same-sex marriage would affect (different-sex) family formation. In this article, I use data on OECD member countries for the period 1980-2009 to examine the effects of the legal recognition of same-sex couples (through marriage or an alternative institution) on different-sex marriage, divorce, and extramarital births. Estimates from difference-in-difference models indicate that the introduction of same-sex marriage or of alternative institutions has no negative effects on family formation. These findings are robust to a multitude of specification checks, including the construction of counterfactuals using the synthetic control method. In addition, the country-by-country case studies provide evidence of homogeneity of the estimated effects.

  13. Secular trends and geographical variations in sex ratio at birth.

    PubMed

    Pavic, Dario

    2015-12-01

    Numerous studies have established the presence of secular trends and geographical variations in sex ratio at birth, albeit with mixed and often contradictory results. In addition, a multitude of environmental, social, economic, demographic and other factors has been proposed to influence the sex ratio at birth, thus complicating the interpretation of both secular trends and geographical variations. In this paper, the current state of knowledge on these issues is presented and critically assessed. Analyzing longer time series of sex ratio at birth with possible cycles and random components is given priority over establishing simple linear trends in the data. In analyzing the geographical variation in the sex ratio at birth, two different levels of analysis are distinguished (global and local), and two different sets of factors affecting the sex ratio at birth are proposed accordingly. Some key guidelines and future research directions are also proposed.

  14. Degradable and comb-like PEG-based copolymers by nitroxide-mediated radical ring-opening polymerization.

    PubMed

    Delplace, Vianney; Tardy, Antoine; Harrisson, Simon; Mura, Simona; Gigmes, Didier; Guillaneuf, Yohann; Nicolas, Julien

    2013-10-14

    Three cyclic ketene acetals, 2-methylene-1,3-dioxepane (MDO), 5,6-benzo-2-methylene-1,3-dioxepane (BMDO), and 2-methylene-4-phenyl-1,3-dioxolane (MPDL), have been copolymerized with oligo(ethylene glycol) methyl ether methacrylate and a small amount of acrylonitrile (or styrene) at 90 °C by nitroxidemediated radical ring-opening polymerization, as a convenient way to prepare degradable PEG-based copolymers for biomedical applications. MPDL was the best candidate, enabling high monomer conversions to be reached and well-defined PEG-based copolymers with adjustable amount of ester groups in the main chain to be synthesized, leading to nearly complete hydrolytic degradation (5% KOH aqueous solution, ambient temperature). The noncytotoxicity of the obtained copolymers was shown on three different cell lines (i.e., fibroblasts, endothelial cells and macrophages), representing a promising approach for the design of degradable precursors for PEGylation and bioconjugation via the NMP technique.

  15. Environmental sex reversal, Trojan sex genes, and sex ratio adjustment: conditions and population consequences.

    PubMed

    Stelkens, Rike B; Wedekind, Claus

    2010-02-01

    The great diversity of sex determination mechanisms in animals and plants ranges from genetic sex determination (GSD, e.g. mammals, birds, and most dioecious plants) to environmental sex determination (ESD, e.g. many reptiles) and includes a mixture of both, for example when an individual's genetically determined sex is environmentally reversed during ontogeny (ESR, environmental sex reversal, e.g. many fish and amphibia). ESD and ESR can lead to widely varying and unstable population sex ratios. Populations exposed to conditions such as endocrine-active substances or temperature shifts may decline over time due to skewed sex ratios, a scenario that may become increasingly relevant with greater anthropogenic interference on watercourses. Continuous exposure of populations to factors causing ESR could lead to the extinction of genetic sex factors and may render a population dependent on the environmental factors that induce the sex change. However, ESR also presents opportunities for population management, especially if the Y or W chromosome is not, or not severely, degenerated. This seems to be the case in many amphibians and fish. Population growth or decline in such species can potentially be controlled through the introduction of so-called Trojan sex genes carriers, individuals that possess sex chromosomes or genes opposite from what their phenotype predicts. Here, we review the conditions for ESR, its prevalence in natural populations, the resulting physiological and reproductive consequences, and how these may become instrumental for population management.

  16. Sex workers talk about sex work: six contradictory characteristics of legalised sex work in Melbourne, Australia.

    PubMed

    Begum, Sufia; Hocking, Jane S; Groves, Jan; Fairley, Christopher K; Keogh, Louise A

    2013-01-01

    Despite research suggesting that legal sex work is safe and that emotional risks and social stigma are of greater concern than health risks, much research on sex work has focused on health risks. Given the legalisation of sex work in Victoria, Australia, it is timely to look beyond health. Three focus groups were conducted with a total of 14 female sex workers on their experience of legal sex work, both positive and negative, and the social acceptability of their profession. Thematic analysis was used to identify the key ways that sex workers described sex work. Women saw legal sex work as safer than illegal sex work, but still not socially acceptable. However, they also described six contradictory elements of sex work, which was seen as: financially rewarding and entrapping; empowering and demeaning; increasing some opportunities while reducing others; flexible and demanding; offering both intimacy and competition; and leading to a 'double life'. While legalisation has improved the safety of sex work, stigma and discrimination persist.

  17. Random sex determination: When developmental noise tips the sex balance.

    PubMed

    Perrin, Nicolas

    2016-12-01

    Sex-determining factors are usually assumed to be either genetic or environmental. The present paper aims at drawing attention to the potential contribution of developmental noise, an important but often-neglected component of phenotypic variance. Mutual inhibitions between male and female pathways make sex a bistable equilibrium, such that random fluctuations in the expression of genes at the top of the cascade are sufficient to drive individual development toward one or the other stable state. Evolutionary modeling shows that stochastic sex determinants should resist elimination by genetic or environmental sex determinants under ecologically meaningful settings. On the empirical side, many sex-determination systems traditionally considered as environmental or polygenic actually provide evidence for large components of stochasticity. In reviewing the field, I argue that sex-determination systems should be considered within a three-ends continuum, rather than the classical two-ends continuum.

  18. Sex differences in the developmental programming of hypertension.

    PubMed

    Ojeda, N B; Intapad, S; Alexander, B T

    2014-02-01

    Experimental models of developmental programming provide proof of concept and support Barker's original findings that link birthweight and blood pressure. Many experimental models of developmental insult demonstrate a sex difference with male offspring exhibiting a higher blood pressure in young adulthood relative to their age-matched female counterparts. It is well recognized that men exhibit a higher blood pressure relative to age-matched women prior to menopause. Yet, whether this sex difference is noted in individuals born with low birthweight is not clear. Sex differences in the developmental programming of blood pressure may originate from innate sex-specific differences in expression of the renin angiotensin system that occur in response to adverse influences during early life. Sex differences in the developmental programming of blood pressure may also involve the influence of the hormonal milieu on regulatory systems key to the long-term control of blood pressure such as the renin angiotensin system in adulthood. In addition, the sex difference in blood pressure in offspring exposed to a developmental insult may involve innate sex differences in oxidative status or the endothelin system or may be influenced by age-dependent changes in the developmental programming of cardiovascular risk factors such as adiposity. Therefore, this review will highlight findings from different experimental models to provide the current state of knowledge related to the mechanisms that contribute to the aetiology of sex differences in the developmental programming of blood pressure and hypertension.

  19. Management of disorders of sex development.

    PubMed

    Hiort, Olaf; Birnbaum, Wiebke; Marshall, Louise; Wünsch, Lutz; Werner, Ralf; Schröder, Tatjana; Döhnert, Ulla; Holterhus, Paul-Martin

    2014-09-01

    The medical term disorders of sex development (DSDs) is used to describe individuals with an atypical composition of chromosomal, gonadal and phenotypic sex, which leads to differences in the development of the urogenital tract and reproductive system. A variety of genetic factors have been identified that affect sex development during gonadal differentiation or in specific disorders associated with altered androgen biosynthesis or action. The diagnosis of DSDs in individuals and the subsequent management of patients and their families requires a targeted and structured approach, involving a multidisciplinary team with effective communication between the disciplines. This approach includes distinct clinical, imaging, laboratory and genetic evaluations of patients with DSDs. Although treatment of patients with DSDs can include endocrine and surgical options, many patients have concerns that arise from past incorrect treatments that were founded on the traditional binary concept of the sexes. To dispel these concerns, it is necessary to create centres of expertise for DSDs that include physicians, surgeons, psychologists and specialists in diagnostic procedures to manage patients and their families. Additionally, the inclusion of trained peer support in the multidisciplinary DSD team seems to be integral to the supportive management of patients with DSDs. Most importantly, dealing with DSDs requires acceptance of the fact that deviation from the traditional definitions of gender is not necessarily pathologic.

  20. Sexing California Clapper Rails using morphological measurements

    USGS Publications Warehouse

    Overton, Cory T.; Casazza, Michael L.; Takekawa, John Y.; Rohmer, Tobias M.

    2009-01-01

    California Clapper Rails (Rallus longirostris obsoletus) have monomorphic plumage, a trait that makes identification of sex difficult without extensive behavioral observation or genetic testing. Using 31 Clapper Rails (22 females, 9 males), caught in south San Francisco Bay, CA, and using easily measurable morphological characteristics, we developed a discriminant function to distinguish sex. We then validated this function on 33 additional rails. Seven morphological measurements were considered, resulting in three which were selected in the discriminate function: culmen length, tarsometatarsus length, and flat wing length. We had no classification errors for the development or testing datasets either with resubstitution or cross-validation procedures. Male California Clapper Rails were 6-22% larger than females for individual morphological traits, and the largest difference was in body mass.  Variables in our discriminant function closely match variables developed for sexing Clapper Rails of Gulf Coast populations. However, a universal discriminant function to sex all Clapper Rail subspecies is not likely because of large and inconsistent differences in morphological traits among subspecies. 

  1. Sex Ratio Elasticity Influences the Selection of Sex Ratio Strategy.

    PubMed

    Wang, Yaqiang; Wang, Ruiwu; Li, Yaotang; Sam Ma, Zhanshan

    2016-12-23

    There are three sex ratio strategies (SRS) in nature-male-biased sex ratio, female-biased sex ratio and, equal sex ratio. It was R. A. Fisher who first explained why most species in nature display a sex ratio of ½. Consequent SRS theories such as Hamilton's local mate competition (LMC) and Clark's local resource competition (LRC) separately explained the observed deviations from the seemingly universal 1:1 ratio. However, to the best of our knowledge, there is not yet a unified theory that accounts for the mechanisms of the three SRS. Here, we introduce the price elasticity theory in economics to define sex ratio elasticity (SRE), and present an analytical model that derives three SRSs based on the following assumption: simultaneously existing competitions for both resources A and resources B influence the level of SRE in both sexes differently. Consequently, it is the difference (between two sexes) in the level of their sex ratio elasticity that leads to three different SRS. Our analytical results demonstrate that the elasticity-based model not only reveals a highly plausible mechanism that explains the evolution of SRS in nature, but also offers a novel framework for unifying two major classical theories (i.e., LMC &LRC) in the field of SRS research.

  2. Sex Ratio Elasticity Influences the Selection of Sex Ratio Strategy

    PubMed Central

    Wang, Yaqiang; Wang, Ruiwu; Li, Yaotang; (Sam) Ma, Zhanshan

    2016-01-01

    There are three sex ratio strategies (SRS) in nature—male-biased sex ratio, female-biased sex ratio and, equal sex ratio. It was R. A. Fisher who first explained why most species in nature display a sex ratio of ½. Consequent SRS theories such as Hamilton’s local mate competition (LMC) and Clark’s local resource competition (LRC) separately explained the observed deviations from the seemingly universal 1:1 ratio. However, to the best of our knowledge, there is not yet a unified theory that accounts for the mechanisms of the three SRS. Here, we introduce the price elasticity theory in economics to define sex ratio elasticity (SRE), and present an analytical model that derives three SRSs based on the following assumption: simultaneously existing competitions for both resources A and resources B influence the level of SRE in both sexes differently. Consequently, it is the difference (between two sexes) in the level of their sex ratio elasticity that leads to three different SRS. Our analytical results demonstrate that the elasticity-based model not only reveals a highly plausible mechanism that explains the evolution of SRS in nature, but also offers a novel framework for unifying two major classical theories (i.e., LMC & LRC) in the field of SRS research. PMID:28009000

  3. Sex Ratio Elasticity Influences the Selection of Sex Ratio Strategy

    NASA Astrophysics Data System (ADS)

    Wang, Yaqiang; Wang, Ruiwu; Li, Yaotang; (Sam) Ma, Zhanshan

    2016-12-01

    There are three sex ratio strategies (SRS) in nature—male-biased sex ratio, female-biased sex ratio and, equal sex ratio. It was R. A. Fisher who first explained why most species in nature display a sex ratio of ½. Consequent SRS theories such as Hamilton’s local mate competition (LMC) and Clark’s local resource competition (LRC) separately explained the observed deviations from the seemingly universal 1:1 ratio. However, to the best of our knowledge, there is not yet a unified theory that accounts for the mechanisms of the three SRS. Here, we introduce the price elasticity theory in economics to define sex ratio elasticity (SRE), and present an analytical model that derives three SRSs based on the following assumption: simultaneously existing competitions for both resources A and resources B influence the level of SRE in both sexes differently. Consequently, it is the difference (between two sexes) in the level of their sex ratio elasticity that leads to three different SRS. Our analytical results demonstrate that the elasticity-based model not only reveals a highly plausible mechanism that explains the evolution of SRS in nature, but also offers a novel framework for unifying two major classical theories (i.e., LMC & LRC) in the field of SRS research.

  4. Animal models of absence epilepsies: What do they model and do sex and sex hormones matter?

    PubMed Central

    van Luijtelaar, Gilles; Onat, Filiz Yilmaz; Gallagher, Martin J.

    2014-01-01

    While epidemiological data suggest a female prevalence in human childhood- and adolescence-onset typical absence epilepsy syndromes, the sex difference is less clear in adult-onset syndromes. In addition, although there are more females than males diagnosed with typical absence epilepsy syndromes, there is a paucity of studies on sex differences in seizure frequency and semiology in patients diagnosed with any absence epilepsy syndrome. Moreover, it is unknown if there are sex differences in the prevalence or expression of atypical absence epilepsy syndromes. Surprisingly, most studies of animal models of absence epilepsy either did not investigate sex differences, or failed to find sex-dependent effects. However, various rodent models for atypical syndromes such as the AY9944 model (prepubertal females show a higher incidence than prepubertal males), BN model also with a higher prevalence in males and the Gabra1 deletion mouse in the C57BL/6J strain offer unique possibilities for the investigation of the mechanisms involved in sex differences. Although the mechanistic bases for the sex differences in humans or these three models are not yet known, studies of the effects of sex hormones on seizures have offered some possibilities. The sex hormones progesterone, estradiol and testosterone exert diametrically opposite effects in genetic absence epilepsy and pharmacologically-evoked convulsive types of epilepsy models. In addition, acute pharmacological effects of progesterone on absence seizures during proestrus are opposite to those seen during pregnancy. 17β-Estradiol has anti-absence seizure effects, but it is only active in atypical absence models. It is speculated that the pro-absence action of progesterone, and perhaps also the delayed pro-absence action of testosterone, are mediated through the neurosteroid allopregnanolone and its structural and functional homolog, androstanediol. These two steroids increase extrasynaptic thalamic tonic GABAergic inhibition

  5. The influence of observers’ sex on attention-demanding performance depends on performers’ sex

    PubMed Central

    Wang, Lijun; Tan, Jinfeng; Chen, Jiangtao; Chen, Antao

    2015-01-01

    Post-error slowing (PES) indicates the slower responses after errors than after correct responses. Prior studies mainly focus on how the observation errors influence one own’s performance, there is no study investigating how other’s monitoring influence one own’s performance. Additionally, the issue that whether social context influences the PES effect differently for females and males is still unclear. To address aforementioned issues, we required the participants to interact with a same-sex or opposite-sex partner to complete a color flanker task together (they sat next to each other, Experiment 1). One was the performer (perform the flanker task), and the other was the observer (monitor the error responses of performer). They alternated their roles in two successive blocks. To further verify the role of the interaction context, a control experiment was conducted in the individual context (Experiment 2). The results revealed that (1) larger PES effect was observed in females than in males in the interaction context; (2) the sex difference of PES effect mainly benefited from the opposite-sex interaction; (3) larger PES effect was observed in the interaction context than in the individual context; (4) females’ performance was influenced after an interaction with a same-sex or opposite-sex partner, whereas males’ performance was merely influenced after an interaction with an opposite-sex partner. Taken together, these findings may suggest that (1) interaction context modulates the PES effect differently for females and males; (2) females are more susceptible to social information and hence more effective to adjust the post-error behaviors. PMID:26379574

  6. Sex control in mammals.

    PubMed

    Bhattacharya, B C

    1958-01-01

    As a step toward control of sex of offspring in mammals, a method for separation of X- and Y-chromosome sperm, based on the differing specific gravity of the 2 types, is described. Sperm sinking to the bottom of an appropriate viscous medium are predominantly the denser X-Chromosome sperm. 99 female rabbits were inseminated with sperm that had been suspended for 24 hours in colloidial media: 38 females received sperm taken from the bottom of a dense medium, and 61 received sperm drawn from the top of a lighter medium. Only 18.2% of the does became pregnant, probably due to insufficient concentration of sperm. Offspring of 4 does impregnated with the lightest fraction were 85.7% male offspring of 7 does impregnated with the heaviest fraction were 77.3% female (vs. 48.2% normal female sex raio; p less than .05). For 7 does impregnanted with sperm taken from nearer the middle of the medium, offspring were 51.7% male.

  7. Allometric Analysis Detects Brain Size-Independent Effects of Sex and Sex Chromosome Complement on Human Cerebellar Organization.

    PubMed

    Mankiw, Catherine; Park, Min Tae M; Reardon, P K; Fish, Ari M; Clasen, Liv S; Greenstein, Deanna; Giedd, Jay N; Blumenthal, Jonathan D; Lerch, Jason P; Chakravarty, M Mallar; Raznahan, Armin

    2017-03-17

    The cerebellum is a large hindbrain structure that is increasingly recognized for its contribution to diverse domains of cognitive and affective processing in human health and disease. Although several of these domains are sex-biased, our fundamental understanding of cerebellar sex differences - including their spatial distribution, potential biological determinants, and independence from brain volume variation - lags far behind that for the cerebrum. Here, we harness automated neuroimaging methods for cerebellar morphometrics in 417 individuals to (i) localize normative male-female differences in raw cerebellar volume, (ii) compare these to sex chromosome effects estimated across five rare X-/Y-chromosome aneuploidy (SCA) syndromes, and (iii) clarify brain size-independent effects of sex and SCA on cerebellar anatomy using a generalizable allometric approach which considers scaling relationships between regional cerebellar volume and brain volume in health. Integration of these approaches shows that (i) sex and SCA effects on raw cerebellar volume are large and distributed, but regionally heterogeneous, (ii) human cerebellar volume scales with brain volume in a highly non-linear and regionally heterogeneous fashion that departs from documented patterns of cerebellar scaling in phylogeny, and (iii) cerebellar organization is modified in a brain size-independent manner by sex (relative expansion of total cerebellum, flocculus, and Crus II-lobule VIIIB volumes in males) and SCA (contraction of total cerebellar, lobule IV and Crus I volumes with additional X- or Y-chromosomes; X-specific contraction of Crus II-lobule VIIIB). Our methods and results clarify the shifts in human cerebellar organization that accompany interwoven variations in sex, sex chromosome complement, and brain size.SIGNIFICANCE STATEMENTCerebellar systems are implicated in diverse domains of sex-biased behavior and pathology, but we lack a basic understanding of how sex differences in the human

  8. Mixed-Sex or Single-Sex Education: How Would Young People Like Their Sex Education and Why?

    ERIC Educational Resources Information Center

    Strange, Vicki; Forrest, Simon; Oakley, Ann

    2003-01-01

    Examined adolescents views about sex education, specifically their views about interaction in single- and mixed-sex groups. Surveys of English secondary school students indicated that most girls, and one-third of boys, want some or all of their sex education to be delivered in single-sex groups. Girls' experiences of sex education with boys…

  9. Disclosing sexual assault to parents: the influence of parental messages about sex.

    PubMed

    Smith, Sharon G; Cook, Sarah L

    2008-11-01

    Without frank discussion of what sex is, women may not learn what sex is not and what experiences constitute sexual assault. This qualitative study explores the relation between parental discussion and messages about sex and women's decisions of whether to disclose sexual assault to parents. Participants were 18 women from diverse ethnic backgrounds. Data were analyzed using a grounded theory approach. Findings indicate that women more often disclosed sexual assault to parents who discussed sex with them in a frank and positive manner. In addition to the role of disclosure in recovery, implications for sex and parent education are discussed.

  10. Project: Strategies for Sex Fairness. Legislation's Push for Sex Fairness.

    ERIC Educational Resources Information Center

    Mook, Corena; Legg, Marilyn

    One of a series of instructional packets to aid schools in reducing sex stereotypes, this inservice guide for use with school personnel is designed to develop an understanding of the provisions of federal legislation that affect sex equity in vocational education. Legislation covered is Title IX of the 1972 Education Amendments and relevant…

  11. [Mode of sex education reflected in attitudes to sex].

    PubMed

    Hamazume, Y; Minochi, M; Waseda, Y

    1976-07-01

    This is a research paper written by 3 midwife students in Kanazawa University. Their research is based on a survey of 88 elementary school girls, 86 junior high school girls, 145 senior high school boys and girls, and 85 teachers, concerning sex and sex education in Kanazawa City, Japan. The authors concluded that: 1) sex education should start from the first grade in the elementary school and the contents should be prepared according to their developmental stage and age; 2) the places of education should be both at school and at home; 3) the entire teachers of a school should take a college level course on sex education and at home, the educators should be guided by specialists and school teachers and they should be able to consult with children when needs arise; 4) the contents of sex education should be physiological facts of both male and female sex, anatomy of sexual organs, the values of life, and practical daily life in marriage; and 5) one should not use the title, sex education in the school, but instead wheneven the opportunity arises in any subject, teachers should educate children little by little, on human nature. In conclusion, the authors think that people's attitude towards sex education in both school and home is still conservative in the Kanazawa City.

  12. THE INDIVIDUAL, SOCIETY AND SEX. BACKGROUND READINGS FOR SEX EDUCATORS.

    ERIC Educational Resources Information Center

    BRODERICK, CARLFRED B.; AND OTHERS

    THIS BOOK IS DESIGNED AS A TEXT PRIMARILY FOR COLLEGE STUDENTS PREPARING TO TEACH SEX EDUCATION OR "EDUCATION IN THE NATURE OF HUMAN SEXUALITY AND THE RELATIONS BETWEEN THE SEXES" IN ELEMENTARY AND SECONDARY SCHOOLS. AN ATTEMPT IS MADE BY THE 13 WRITERS, MOST OF THEM SOCIOLOGISTS OR PSYCHOLOGISTS, TO DISTINGUISH BETWEEN THE KNOWLEDGE WHICH THE…

  13. Sex Knowledge, Sex Guilt and Sexual Behavior among University Students.

    ERIC Educational Resources Information Center

    Brown, Idalyn S.; Pollack, Robert H.

    Previous research has suggested a high level of sexual activity among students, often involving unprotected intercourse. To better understand what factors contribute to consistent use of effective contraception, the relationship between sexual knowledge and sexual behavior and the relationship of sex guilt to sex knowledge were investigated in a…

  14. Sense about Sex: Media, Sex Advice, Education and Learning

    ERIC Educational Resources Information Center

    Attwood, Feona; Barker, Meg John; Boynton, Petra; Hancock, Justin

    2015-01-01

    The media are widely acknowledged as important in sex and relationship education, but they are usually associated with "bad" effects on young people in contrast to the "good" knowledge represented by more informational and educational formats. In this paper we look at sex advice giving in newspapers, magazines and television in…

  15. Meiotic sex chromosome inactivation.

    PubMed

    Turner, James M A

    2007-05-01

    X chromosome inactivation is most commonly studied in the context of female mammalian development, where it performs an essential role in dosage compensation. However, another form of X-inactivation takes place in the male, during spermatogenesis, as germ cells enter meiosis. This second form of X-inactivation, called meiotic sex chromosome inactivation (MSCI) has emerged as a novel paradigm for studying the epigenetic regulation of gene expression. New studies have revealed that MSCI is a special example of a more general mechanism called meiotic silencing of unsynapsed chromatin (MSUC), which silences chromosomes that fail to pair with their homologous partners and, in doing so, may protect against aneuploidy in subsequent generations. Furthermore, failure in MSCI is emerging as an important etiological factor in meiotic sterility.

  16. Mallard age and sex determination from wings

    USGS Publications Warehouse

    Carney, S.M.; Geis, A.D.

    1960-01-01

    This paper describes characters on the wing plumage of the mallard that indicate age and sex. A key outlines a logical order in which to check age and sex characters on wings. This method was tested and found to be more than 95 percent reliable, although it was found that considerable practice and training with known-age specimens was required to achieve this level of accuracy....The implications of this technique and the sampling procedure it permits are discussed. Wing collections could provide information on production, and, if coupled with a banding program could permit seasonal population estimates to be calculated. In addition, representative samples of wings would provide data to check the reliability of several other waterfowl surveys.

  17. The Consequences of Sex Selection

    ERIC Educational Resources Information Center

    Rothman, Barbara Katz

    2006-01-01

    A group of researchers at Baylor College of Medicine in Houston are set to do a long-term study of families that would permit to select the sex of their babies through genetic testing before implanting the embryo in the mother. Technologies such as in vitro fertilization involved in selecting a baby's sex has societal and psychological…

  18. Heterosexuality and Sex-Typing.

    ERIC Educational Resources Information Center

    Allgeier, Elizabeth R.

    Previous research (Bem, 1976) has shown that sex-typed and androgynous persons differ in their behavior in a variety of situations. The present paper describes four studies of the relationship of sex-typing to sexual socialization and to heterosexual attitudes and behavior. This program of research indicates that persons do differ in their sexual…

  19. Viewpoints: Sex Education and Deafness.

    ERIC Educational Resources Information Center

    Fitz-Gerald, Della, Ed.; Fitz-Gerald, Max, Ed.

    The 10 contributed papers are intended to clarify the major issues of sex education and deafness and offer realistic responses to the expressed needs of professionals serving the deaf. Papers have the following titles and authors: "Sex Education from the Deaf Perspective" (Robert Davila); "Sexuality and Deafness: An Overview" (Max Fitz-Gerald and…

  20. Brain Dysfunction in Sex Offenders.

    ERIC Educational Resources Information Center

    Galski, Thomas; And Others

    1990-01-01

    Attempted to establish the connection between disordered sexuality and brain impairment by using newly developed techniques of neuropsychological investigation with sex offenders (n=35). Results indicated a major portion of the sex offenders showed impaired brain functioning on Luria-Nebraska Neuropsychological Battery. (Author/ABL)

  1. Sex Differences in Social Behavior.

    ERIC Educational Resources Information Center

    Baker, Therese

    Examining theories from a wide spectrum of disciplines, this paper categorizes research on sex differences in social behavior into four groups and examines the implications of each. The first category of research interprets sex differences as the result of anatomical differences which later affect psychological roles. The implication of this…

  2. Sex Differences in Fetal Habituation

    ERIC Educational Resources Information Center

    Hepper, Peter G.; Dornan, James C.; Lynch, Catherine

    2012-01-01

    There is some evidence for sex differences in habituation in the human fetus, but it is unknown whether this is due to differences in central processing (habituation) or in more peripheral processes, sensory or motor, involved in the response. This study examined whether the sex of the fetus influenced auditory habituation at 33 weeks of…

  3. Teaching Sex Education in Thailand

    ERIC Educational Resources Information Center

    Kay, Noy S.; Jones, Megan R.; Jantaraweragul, Sudgasame

    2010-01-01

    The purposes of this study were to examine the current situation pertaining to the teaching of sex education and identify barriers to teaching sex education among Thai health education teachers. A survey questionnaire was administered to 193 health education teachers who participated in this study. The questionnaire was comprised of three parts:…

  4. Sex Differences in Dichotic Listening

    ERIC Educational Resources Information Center

    Voyer, Daniel

    2011-01-01

    The present study quantified the magnitude of sex differences in perceptual asymmetries as measured with dichotic listening. This was achieved by means of a meta-analysis of the literature dating back from the initial use of dichotic listening as a measure of laterality. The meta-analysis included 249 effect sizes pertaining to sex differences and…

  5. The joy of sex pheromones

    PubMed Central

    Gomez-Diaz, Carolina; Benton, Richard

    2013-01-01

    Sex pheromones provide an important means of communication to unite individuals for successful reproduction. Although sex pheromones are highly diverse across animals, these signals fulfil common fundamental roles in enabling identification of a mating partner of the opposite sex, the appropriate species and of optimal fecundity. In this review, we synthesize both classic and recent investigations on sex pheromones in a range of species, spanning nematode worms, insects and mammals. These studies reveal comparable strategies in how these chemical signals are produced, detected and processed in the brain to regulate sexual behaviours. Elucidation of sex pheromone communication mechanisms both defines outstanding models to understand the molecular and neuronal basis of chemosensory behaviours, and reveals how similar evolutionary selection pressures yield convergent solutions in distinct animal nervous systems. EMBO reports advance online publication 13 September 2013; doi:10.1038/embor.2013.140 PMID:24030282

  6. Sex differences in primary hypertension

    PubMed Central

    2012-01-01

    Men have higher blood pressure than women through much of life regardless of race and ethnicity. This is a robust and highly conserved sex difference that it is also observed across species including dogs, rats, mice and chickens and it is found in induced, genetic and transgenic animal models of hypertension. Not only do the differences between the ovarian and testicular hormonal milieu contribute to this sexual dimorphism in blood pressure, the sex chromosomes also play a role in and of themselves. This review primarily focuses on epidemiological studies of blood pressure in men and women and experimental models of hypertension in both sexes. Gaps in current knowledge regarding what underlie male-female differences in blood pressure control are discussed. Elucidating the mechanisms underlying sex differences in hypertension may lead to the development of anti-hypertensives tailored to one's sex and ultimately to improved therapeutic strategies for treating this disease and preventing its devastating consequences. PMID:22417477

  7. In Search of Emerging Same-Sex Sexuality: Romantic Attractions at Age 13 Years.

    PubMed

    Li, Gu; Hines, Melissa

    2016-10-01

    Sex-typed behavior in childhood is significantly related to sexual orientation in adulthood. In addition, same-sex attractions in early adolescence are more non-exclusive than in adulthood and can differ from later same-sex orientations. However, little research has focused on romantic attractions as they emerge during early adolescence. Drawing a sample from the Avon Longitudinal Study of Parents and Children (197 girls, 204 boys), the current study examined whether same-sex romantic attractions at age 13 years were exclusive, and whether they were predicted by sex-typed behavior at age 3.5 years. No young adolescents in this sample reported exclusive same-sex attractions, and increased same-sex attractions were not significantly related to reduced other-sex sexualities. Childhood sex-typed behavior did not significantly predict early same-sex attractions, suggesting that early same-sex attractions differ from later same-sex orientations. The current study highlights the importance of studying the development of sexuality beginning prior to adulthood.

  8. Sex-related genomic sequences in cartilaginous fish: an overview.

    PubMed

    Rocco, L

    2013-01-01

    Sex determination and differentiation are key events in the development of either the testis or ovary in fish. Sex determination mechanisms include environmental and genetic regulation. Research on sex determination systems and their related genes have been implemented in the teleost species, but the amount of information about these genes in cartilaginous fish is very scarce. This paper summarizes the few available data on molecular studies and chromosome localization of specific sequences useful to discriminate between various chromosome pairs in the common torpedo, Torpedo torpedo, and in the scyliorhinid coral catshark, Atelomycterus marmoratus, species that do not have morphologically distinct sex chromosomes. In addition, recent results obtained by sequence analysis of foxl2, a female-specific gene expressed during early phases of gonadal development in interesting key-species, such as the holocephalian Callorhinchus milii, is discussed. Nevertheless, the mechanism of sex determination in cartilaginous fish remains largely unknown. Further research needs to be carried out regarding the importance of basic and applied sex determination studies in fish, including chromosomal distribution of sex-related sequences.

  9. Genetics of cardiovascular disease: importance of sex and ethnicity

    PubMed Central

    Winham, Stacey J.; de Andrade, Mariza; Miller, Virginia M.

    2015-01-01

    Sex differences in incidence and prevalence of and morbidity and mortality from cardiovascular disease are well documented. However, many studies examining the genetic basis for cardiovascular disease fail to consider sex as a variable in the study design, in part, because there is an inherent difficulty in studying the contribution of the sex chromosomes in women due to X chromosome inactivation. This paper will provide general background on the X and Y chromosomes (including gene content, the pseudoautosomal regions, and X chromosome inactivation), discuss how sex chromosomes have been ignored in Genome-wide Association Studies (GWAS) of cardiovascular diseases, and discuss genetics influencing development of cardiovascular risk factors and atherosclerosis with particular attention to carotid intima-medial thickness, and coronary arterial calcification based on sex-specific studies. In addition, a brief discussion of how ethnicity and hormonal status act as confounding variables in sex-based analysis will be considered along with methods for statistical analysis to account for sex in cardiovascular disease. PMID:25817330

  10. Limitations of the mandibular canine index in sex assessment.

    PubMed

    Acharya, Ashith B; Mainali, Sneedha

    2009-02-01

    Measuring teeth is a useful adjunct in sex assessment. Canines, in particular, have the greatest degree of sexual dimorphism, resist disease and survive postmortem trauma, rendering them highly valuable in identification. Hence, their exclusive use in odontometric sex assessment using the Mandibular Canine Index (MCI) has been advocated before. The MCI is derived as the ratio of the mesiodistal (MD) dimension of canines and the inter-canine arch width. This study has tested the use of the MCI in assessing sex on a sample from Nepal and compared its accuracy to that of absolute canine measurements. Measurements were obtained from one hundred-and-seventeen dental stone casts that belonged to 63 males and 54 females, all young adults in the age-group 19-28 years. Independent samples t-test revealed no significant sexual dimorphism in the MCI. In addition, discriminant analysis of the MCI also had poor ability to differentiate the sexes. In contrast, the absolute canine measurements revealed statistically significant male-female difference and superior ability to differentiate sex using discriminant analysis. The poor ability of the MCI in sex assessment is attributed to it being a relative value-it is obtained as the ratio of two absolute measurements (MD dimension of canines and inter-canine arch width) and does not reflect sex differences that exist in the absolute measurements per se.

  11. Do Psychological Sex Differences Reflect Evolutionary Bisexual Partitioning?

    PubMed

    Trofimova, Irina

    2015-01-01

    This article analyzes sex differences in communicative and exploratory abilities and mental disabilities from the rarely discussed perspective of sex differences in the shape of phenotypic distributions. The article reviews the most consistent findings related to such differences and compares them with the evolutionary theory of sex (ETS). The ETS considers sexual dimorphism as a functional specialization of a species into 2 partitions: variational and conservational. The analysis suggests that male superiority in risk and sensation seeking and physical abilities; higher rates of psychopathy, dyslexia, and autism; and higher birth and accidental death rates reflects the systemic variational function of the male sex. Female superiority in verbal abilities, lawfulness, socialization, empathy, and agreeableness is presented as a reflection of the systemic conservational function of the female sex. From this perspective psychological sex differences in communicative and exploratory abilities might not just be an accidental result of sexual selection or labor distribution in early humans. It might reflect a global functional differentiation tendency within a species to expand its phenotypic diversity and at the same time to conserve beneficial features in the species' behavior. The article also offers an addition to the ETS by suggesting that the male sex (variable partition) plays an evolutionary role in pruning of the redundant excesses in a species' bank of beneficial characteristics despite resistance from the conservational partition.

  12. Developmental synergism of steroidal estrogens in sex determination.

    PubMed

    Bergeron, J M; Willingham, E; Osborn, C T; Rhen, T; Crews, D

    1999-02-01

    Gonadal sex in the red-eared slider turtle, Trachemys scripta, is determined by incubation temperature during embryonic development. Evidence suggests that temperature determines sex by influencing steroid hormone metabolism and/or sensitivity: steroidogenic enzyme inhibitors or exogenous sex steroid hormones and their man-made analogs override (or enhance) temperature effects on sex determination. Specifically, nonaromatizable androgens and aromatase inhibitors induce testis differentiation at female-producing temperatures, whereas aromatizable androgens and estrogens induce ovary differentiation at male-producing temperatures. Moreover, natural estrogens and temperature synergize to produce more females than would be expected if estrogens and temperature had purely additive effects on sex determination. In this study, we use sex reversal of turtle embryos incubated at a male-producing temperature to examine synergism among steroidal estrogens: estrone, 17ss-estradiol, and estriol. A low dose of 17ss-estradiol (200 ng) showed significant synergism when administered with a single low dose of estriol (10 ng). Likewise, a single low dose of estrone (250 ng) had a synergistic effect when combined with the same low dose of estriol (10 ng). We conclude that the weak natural estrogens estrone and 17ss-estradiol synergize with a low dose of the more potent estriol to reverse gonadal sex during the critical period of sexual differentiation. These results suggest that weak environmental estrogens may also synergize with stronger natural estrogens.

  13. Sex-specific determinants of fitness in a social mammal.

    PubMed

    Lardy, Sophie; Allainé, Dominique; Bonenfant, Christophe; Cohas, Aurélie

    2015-11-01

    Sociality should evolve when the fitness benefits of group living outweigh the costs. Theoretical models predict an optimal group size maximizing individual fitness. However, beyond the number of individuals present in a group, the characteristics of these individuals, like their sex, are likely to affect the fitness payoffs of group living. Using 20 years of individually based data on a social mammal, the Alpine marmot (Marmota marmota), we tested for the occurrence of an optimal group size and composition, and for sex-specific effects of group characteristics on fitness. Based on lifetime data of 52 males and 39 females, our findings support the existence of an optimal group size maximizing male fitness and an optimal group composition maximizing fitness of males and females. Additionally, although group characteristics (i.e., size, composition and instability) affecting male and female fitness differed, fitness depended strongly on the number of same-sex subordinates within the social group in the two sexes. By comparing multiple measures of social group characteristics and of fitness in both sexes, we highlighted the sex-specific determinants of fitness in the two sexes and revealed the crucial role of intrasexual competition in shaping social group composition.

  14. Deleterious mutations and selection for sex in finite diploid populations.

    PubMed

    Roze, Denis; Michod, Richard E

    2010-04-01

    In diploid populations, indirect benefits of sex may stem from segregation and recombination. Although it has been recognized that finite population size is an important component of selection for recombination, its effects on selection for segregation have been somewhat less studied. In this article, we develop analytical two- and three-locus models to study the effect of recurrent deleterious mutations on a modifier gene increasing sex, in a finite diploid population. The model also incorporates effects of mitotic recombination, causing loss of heterozygosity (LOH). Predictions are tested using multilocus simulations representing deleterious mutations occurring at a large number of loci. The model and simulations show that excess of heterozygosity generated by finite population size is an important component of selection for sex, favoring segregation when deleterious alleles are nearly additive to dominant. Furthermore, sex tends to break correlations in homozygosity among selected loci, which disfavors sex when deleterious alleles are either recessive or dominant. As a result, we find that it is difficult to maintain costly sex when deleterious alleles are recessive. LOH tends to favor sex when deleterious mutations are recessive, but the effect is relatively weak for rates of LOH corresponding to current estimates (of the order 10(-4)-10(-5)).

  15. Identification of the sex genes in an early diverged fungus.

    PubMed

    Idnurm, Alexander; Walton, Felicia J; Floyd, Anna; Heitman, Joseph

    2008-01-10

    Sex determination in fungi is controlled by a small, specialized region of the genome in contrast to the large sex-specific chromosomes of animals and some plants. Different gene combinations reside at these mating-type (MAT) loci and confer sexual identity; invariably they encode homeodomain, alpha-box, or high mobility group (HMG)-domain transcription factors. So far, MAT loci have been characterized from a single monophyletic clade of fungi, the Dikarya (the ascomycetes and basidiomycetes), and the ancestral state and evolutionary history of these loci have remained a mystery. Mating in the basal members of the kingdom has been less well studied, and even their precise taxonomic inter-relationships are still obscure. Here we apply bioinformatic and genetic mapping to identify the sex-determining (sex) region in Phycomyces blakesleeanus (Zygomycota), which represents an early branch within the fungi. Each sex allele contains a single gene that encodes an HMG-domain protein, implicating the HMG-domain proteins as an earlier form of fungal MAT loci. Additionally, one allele also contains a copy of a unique, chromosome-specific repetitive element, suggesting a generalized mechanism for the earliest steps in the evolution of sex determination and sex chromosome structure in eukaryotes.

  16. Territory Quality and Plumage Morph Predict Offspring Sex Ratio Variation in a Raptor.

    PubMed

    Chakarov, Nayden; Pauli, Martina; Mueller, Anna-Katharina; Potiek, Astrid; Grünkorn, Thomas; Dijkstra, Cor; Krüger, Oliver

    2015-01-01

    Parents may adapt their offspring sex ratio in response to their own phenotype and environmental conditions. The most significant causes for adaptive sex-ratio variation might express themselves as different distributions of fitness components between sexes along a given variable. Several causes for differential sex allocation in raptors with reversed sexual size dimorphism have been suggested. We search for correlates of fledgling sex in an extensive dataset on common buzzards Buteo buteo, a long-lived bird of prey. Larger female offspring could be more resource-demanding and starvation-prone and thus the costly sex. Prominent factors such as brood size and laying date did not predict nestling sex. Nonetheless, lifetime sex ratio (LSR, potentially indicative of individual sex allocation constraints) and overall nestling sex were explained by territory quality with more females being produced in better territories. Additionally, parental plumage morphs and the interaction of morph and prey abundance tended to explain LSR and nestling sex, indicating local adaptation of sex allocation However, in a limited census of nestling mortality, not females but males tended to die more frequently in prey-rich years. Also, although females could have potentially longer reproductive careers, a subset of our data encompassing full individual life histories showed that longevity and lifetime reproductive success were similarly distributed between the sexes. Thus, a basis for adaptive sex allocation in this population remains elusive. Overall, in common buzzards most major determinants of reproductive success appeared to have no effect on sex ratio but sex allocation may be adapted to local conditions in morph-specific patterns.

  17. Territory Quality and Plumage Morph Predict Offspring Sex Ratio Variation in a Raptor

    PubMed Central

    Chakarov, Nayden; Pauli, Martina; Mueller, Anna-Katharina; Potiek, Astrid; Grünkorn, Thomas; Dijkstra, Cor; Krüger, Oliver

    2015-01-01

    Parents may adapt their offspring sex ratio in response to their own phenotype and environmental conditions. The most significant causes for adaptive sex-ratio variation might express themselves as different distributions of fitness components between sexes along a given variable. Several causes for differential sex allocation in raptors with reversed sexual size dimorphism have been suggested. We search for correlates of fledgling sex in an extensive dataset on common buzzards Buteo buteo, a long-lived bird of prey. Larger female offspring could be more resource-demanding and starvation-prone and thus the costly sex. Prominent factors such as brood size and laying date did not predict nestling sex. Nonetheless, lifetime sex ratio (LSR, potentially indicative of individual sex allocation constraints) and overall nestling sex were explained by territory quality with more females being produced in better territories. Additionally, parental plumage morphs and the interaction of morph and prey abundance tended to explain LSR and nestling sex, indicating local adaptation of sex allocation However, in a limited census of nestling mortality, not females but males tended to die more frequently in prey-rich years. Also, although females could have potentially longer reproductive careers, a subset of our data encompassing full individual life histories showed that longevity and lifetime reproductive success were similarly distributed between the sexes. Thus, a basis for adaptive sex allocation in this population remains elusive. Overall, in common buzzards most major determinants of reproductive success appeared to have no effect on sex ratio but sex allocation may be adapted to local conditions in morph-specific patterns. PMID:26445010

  18. Risk Comparison among Youth Who Report Sex with Same-Sex versus Both-Sex Partners

    ERIC Educational Resources Information Center

    Moon, Martha W.; Fornili, Katherine; O'Briant, Amanda L.

    2007-01-01

    This article examines risk behavior among youth attending support groups for sexual minority youth in Richmond, Virginia, using a structured survey, with particular attention to partner selection and its relationship to risk. Within this generally high-risk group, youth reporting sex partners of both sexes had significantly higher risk profiles,…

  19. [Sex education and population policies].

    PubMed

    Rodriguez, G

    1991-01-01

    Controversy about sex education programs has hampered sustained actin or curricular extension in Mexico beyond programs directly related to demographic policies. The 1st sex education in Mexico perhaps dated back to 1908 when physicians and other health professionals, inspired by the eugenics movement, offered sex education to prevent venereal diseases and maternal and/infant mortality. A 2nd attempt occurred in 1916 in the context of the women's suffrage movement. The 2 perspectives were integrated in a sex education project in 1933, as part of the program of "revolutionary education" legitimized by the progressive and modernizing government of the time. Conservative groups including some parents' associations and religious organizations insisted on their exclusive right to provide sex education, and in following decades they opposed social programs related to primary health care and women's rights. In the 1960, the introduction to Mexico of modern contraceptives and the questioning by young people of virginity and the double standard of sexual morality were not aided by any formal program of sex education in Mexico. In the early 1970s, the need to transform fertility patterns led to establishment of formal sex education programs at the national level. The focus was on reproduction and demographic aspects. Most students were exposed to classes and textbooks covering puberty, human reproduction, contraception, and sexually transmitted diseases. The intense activity of the early years did not continue in the subsequent program, but currently, the threat of AIDS and economic and social pressures are prompting a new political will in favor of sex education. Sex education is seen as the main strategy for AIDS prevention programs. Homosexual groups are demonstrating a new political pressure as civil organizations integrated into a new sector demanding sex education. At the same time, population policies are assuming a predominant position in official discourse as a

  20. A Framework for Sex Role Counseling.

    ERIC Educational Resources Information Center

    Cook, Ellen Piel

    1985-01-01

    The androgyny model of masculinity and femininity serves as the basis for a framework for sex role counseling applicable to both sexes. Examples of sex role problems, counseling goals, and interventions are described. (Author/BL)

  1. Living the reality of forced sex work: perspectives from young migrant women sex workers in northern Vietnam.

    PubMed

    Rushing, Rosanne; Watts, Charlotte; Rushing, Sharon

    2005-01-01

    Young women are often lured or forced into selling sex as a result of migrating from rural to urban areas to find work. In this setting, they are exposed to high-risk situations, which may leave them vulnerable to exploitation. Using interviews with young migrant women currently working as sex workers in northern Vietnam, we recorded the perspectives of their initiation into sex work and life as a sex worker. The study found that high levels of forced sex and sexual exploitation were experienced by the majority of the young women interviewed. The young women describe their entry into sex work, first sexual experience (intercourse), violence, and condom negotiation and use. Although access to health care was available, the young women perceived the stigma attached to sex work as a barrier to receiving health care, and thus, preferred health education and care from peers. Health education programs focusing on peer education and support are essential for protecting and empowering these young women. In addition, policies and programs must work toward effective strategies to protect young migrant women.

  2. Same-sex marriage: a new social phenomenon.

    PubMed

    Chamie, Joseph; Mirkin, Barry

    2011-01-01

    Same-sex marriage (SSM) is a new social phenomenon. In modern times SSM did not exist until the 21st century when an increasing number of countries began permitting same-sex couples to marry legally. This study presents statistical and related evidence concerning SSM worldwide, with special attention to the United States, where SSM has evolved into a major political and legal issue. In addition to examining data on levels and trends, differentials between men and women are investigated. The study also considers common arguments for and against SSM and likely changes in laws and policies that may occur. Although same-sex marriage now exists in a small number of countries and US states, its consequences and implications are being felt far beyond the borders of those countries and areas. In coming years same-sex marriage will remain a controversial and salient part of the legal, political, and cultural landscape, locally, nationally, and internationally.

  3. Sex differences in prenatal epigenetic programming of stress pathways.

    PubMed

    Bale, Tracy L

    2011-07-01

    Maternal stress experience is associated with neurodevelopmental disorders including schizophrenia and autism. Recent studies have examined mechanisms by which changes in the maternal milieu may be transmitted to the developing embryo and potentially translated into programming of the epigenome. Animal models of prenatal stress have identified important sex- and temporal-specific effects on offspring stress responsivity. As dysregulation of stress pathways is a common feature in most neuropsychiatric diseases, molecular and epigenetic analyses at the maternal-embryo interface, especially in the placenta, may provide unique insight into identifying much-needed predictive biomarkers. In addition, as most neurodevelopmental disorders present with a sex bias, examination of sex differences in the inheritance of phenotypic outcomes may pinpoint gene targets and specific windows of vulnerability in neurodevelopment, which have been disrupted. This review discusses the association and possible contributing mechanisms of prenatal stress in programming offspring stress pathway dysregulation and the importance of sex.

  4. What Asexuality Contributes to the Same-Sex Marriage Discussion

    PubMed Central

    Scherrer, Kristin S.

    2010-01-01

    While same-sex marriage debates have captured public attention, it is but one component of a broader discussion regarding the role of marriage in a changing society. To inform this discussion, I draw on qualitative, Internet survey data from 102 self-identified asexual individuals. I find that asexual relationships are complicated and nuanced in ways that have implications for a GLBTQ political agenda, including same-sex marriage recognition. In addition, findings indicate that assumptions of sex and sexuality in relationships are problematic and that present language for describing relationships is limiting. Findings suggest a social justice agenda for marginalized sexualities should be broader in scope than same-sex marriage. PMID:20596244

  5. The use of the sex pheromone as an evolutionary solution to food source selection in caterpillars.

    PubMed

    Poivet, Erwan; Rharrabe, Kacem; Monsempes, Christelle; Glaser, Nicolas; Rochat, Didier; Renou, Michel; Marion-Poll, Frédéric; Jacquin-Joly, Emmanuelle

    2012-01-01

    Sex pheromones are released by adults of a species to elicit a sexual interaction with the other sex of the same species. Here we report an unexpected effect of a moth sex pheromone on the caterpillars of the same species. We demonstrate that larvae of the cotton leafworm Spodoptera littoralis are attracted by the moth sex pheromone and that this phenomenon is independent of sex determination. In addition, we show that the olfactory sensilla carried by the caterpillar antennae are sensitive to the pheromone and that the caterpillar sensilla express pheromone-binding proteins that are used by adult antennae to bind pheromone components. Finally, we demonstrate that the larvae are preferentially attracted to a food source when it contains the sex pheromone main component. A possible interpretation of these results is that the sex pheromone is used to promote food search in caterpillars, opening potential new routes for insect pest management.

  6. Sex differences in the mechanisms underlying long QT syndrome.

    PubMed

    Salama, Guy; Bett, Glenna C L

    2014-09-01

    Sexual dimorphism is a well-established phenomenon, but its degree varies tremendously among species. Since the early days of Einthoven's development of the three-lead galvanometer ECG, we have known there are marked differences in QT intervals of men and women. It required over a century to appreciate the profound implications of sex-based electrophysiological differences in QT interval on the panoply of sex differences with respect to arrhythmia risk, drug sensitivity, and treatment modalities. Little is known about the fundamental mechanism responsible for sex differences in electrical substrate of the human heart, in large part due to the lack of tissue availability. Animal models are an important research tool, but species differences in the sexual dimorphism of the QT interval, the ionic currents underlying the cardiac repolarization, and effects of sex steroids make it difficult to interpolate animal to human sex differences. In addition, in some species, different strains of the same animal model yield conflicting data. Each model has its strengths, such as ease of genetic manipulation in mice or size in dogs. However, many animals do not reproduce the sexual dimorphism of QT seen in humans. To match sex linked prolongation of QT interval and arrhythmogenic phenotype, the current data suggest that the rabbit may be best suited to provide insight into sex differences in humans. In the future, emerging technologies such as induced pluripotent stem cell derived cardiac myocyte systems may offer the opportunity to study sex differences in a controlled hormonal situation in the context of a sex specific human model system.

  7. Additive Similarity Trees

    ERIC Educational Resources Information Center

    Sattath, Shmuel; Tversky, Amos

    1977-01-01

    Tree representations of similarity data are investigated. Hierarchical clustering is critically examined, and a more general procedure, called the additive tree, is presented. The additive tree representation is then compared to multidimensional scaling. (Author/JKS)

  8. [Teens and sex education].

    PubMed

    Buj Pereda, M José

    2013-03-01

    It is widely debated among mental health professionals, among whom I include myself; the fact that not only teenagers who come to our clinics need good sex education, but that parents and/or legal guardians, often also it would be beneficial. I do not mean much to the sexual practice itself; the mechanics or completion of the act, as well as the training that is not received, when dealing with certain issues with young adolescents. Why can cost both accept that, well before age 17, have already fully developed sexuality? The answer could be as simple as saying that, it's not on focusing on the "do" but, from the "feel" and the latter field seems to be much more muddy and complex than the first. The management process of sexual development of our children and teens, begins when we are ready to grow ourselves in this respect, to overcome conflicts, needs, fears and insecurities of their own. Only then, when we will be able to become true and effective sexual educators and counselors of the young.

  9. Sex ratios in bumble bees

    PubMed Central

    Bourke, A. F. G.

    1997-01-01

    The median proportion of investment in females among 11 populations of seven bumble bee (Bombus) species was 0.32 (range 0.07 to 0.64). By contrast, two species of workerless social parasites in the related genus Psithyrus had female-biased sex allocation, the reasons for which remain unclear. Male-biased sex allocation in Bombus contradicts the predictions of Trivers and Hare's sex ratio model for the social Hymenoptera, which are that the population sex investment ratio should be 0.5 (1:1) under queen control and 0.75 (3:1 females:males) under worker control (assuming single, once-mated, outbred queens and non-reproductive workers). Male bias in Bombus does not appear to be either an artefact, or purely the result of symbiotic sex ratio distorters. According to modifications of the Trivers–Hare model, the level of worker male-production in Bombus is insufficient to account for observed levels of male bias. There is also no evidence that male bias arises from either local resource competition (related females compete for resources) or local mate enhancement (related males cooperate in securing mates). Bulmer presented models predicting sexual selection for protandry (males are produced before females) in annual social Hymenoptera and, as a consequence (given some parameter values), male-biased sex allocation. Bumble bees fit the assumptions of Bulmer's models and are protandrous. These models therefore represent the best current explanation for the bees' male-biased sex investment ratios. This conclusion suggests that the relative timing of the production of the sexes strongly influences sex allocation in the social Hymenoptera.

  10. Demography and sex work characteristics of female sex workers in India

    PubMed Central

    Dandona, Rakhi; Dandona, Lalit; Kumar, G Anil; Gutierrez, Juan Pablo; McPherson, Sam; Samuels, Fiona; Bertozzi, Stefano M

    2006-01-01

    Background The majority of sex work in India is clandestine due to unfavorable legal environment and discrimination against female sex workers (FSWs). We report data on who these women are and when they get involved with sex work that could assist in increasing the reach of HIV prevention activities for them. Methods Detailed documentation of demography and various aspects of sex work was done through confidential interviews of 6648 FSWs in 13 districts in the Indian state of Andhra Pradesh. The demography of FSWs was compared with that of women in the general population. Results A total of 5010 (75.4%), 1499 (22.5%), and 139 (2.1%) street-, home-, and brothel-based FSWs, respectively, participated. Comparison with women of Andhra Pradesh revealed that the proportion of those aged 20–34 years (75.6%), belonging to scheduled caste (35.3%) and scheduled tribe (10.5%), illiterate (74.7%), and of those separated/divorced (30.7%) was higher among FSWs (p < 0.001). The FSWs engaged in sex work for >5 years were more likely to be non-street-based FSWs, illiterate, living in small urban towns, and to have started sex work between 12–15 years of age. The mean age at starting sex work (21.7 years) and gap between the first vaginal intercourse and the first sexual intercourse in exchange for money (6.6 years) was lower for FSWs in the rural areas as compared with those in large urban areas (23.9 years and 8.8 years, respectively). Conclusion These data highlight that women struggling with illiteracy, lower social status, and less economic opportunities are especially vulnerable to being infected by HIV, as sex work may be one of the few options available to them to earn money. Recommendations for actions are made for long-term impact on reducing the numbers of women being infected by HIV in addition to the current HIV prevention efforts in India. PMID:16615869

  11. Sex in the brain: hormones and sex differences

    PubMed Central

    Marrocco, Jordan; McEwen, Bruce S.

    2016-01-01

    Contrary to popular belief, sex hormones act throughout the entire brain of both males and females via both genomic and nongenomic receptors. Many neural and behavioral functions are affected by estrogens, including mood, cognitive function, blood pressure regulation, motor coordination, pain, and opioid sensitivity. Subtle sex differences exist for many of these functions that are developmentally programmed by hormones and by not yet precisely defined genetic factors, including the mitochondrial genome. These sex differences, and responses to sex hormones in brain regions and upon functions not previously regarded as subject to such differences, indicate that we are entering a new era in our ability to understand and appreciate the diversity of gender-related behaviors and brain functions. PMID:28179809

  12. Sex Determination: Separate Sexes Are a Double Turnoff in Melons.

    PubMed

    Ma, Wen-Juan; Pannell, John R

    2016-02-22

    Flowers with only one sexual function typically result from the developmental suppression of the other. A recent study that shows how this is achieved has important implications for models of the evolution of separate sexes in plants.

  13. Sex in the brain: hormones and sex differences.

    PubMed

    Marrocco, Jordan; McEwen, Bruce S

    2016-12-01

    Contrary to popular belief, sex hormones act throughout the entire brain of both males and females via both genomic and nongenomic receptors. Many neural and behavioral functions are affected by estrogens, including mood, cognitive function, blood pressure regulation, motor coordination, pain, and opioid sensitivity. Subtle sex differences exist for many of these functions that are developmentally programmed by hormones and by not yet precisely defined genetic factors, including the mitochondrial genome. These sex differences, and responses to sex hormones in brain regions and upon functions not previously regarded as subject to such differences, indicate that we are entering a new era in our ability to understand and appreciate the diversity of gender-related behaviors and brain functions.

  14. Sex education laws and policies.

    PubMed

    Roemer, R; Paxman, J M

    1985-01-01

    Sex education laws and policies are important in facilitating or blocking efforts to provide adolescents with sexuality education and information. Legislation in developing and industrialized countries concerns both sexuality education in schools and adolescents' access to information on contraception and abortion. Although laws and policies vary, the trend is to remove laws restricting sex education and information and to promote the flow of reproductive health information for adolescents. The integration of sex education with programs that provide contraceptive services offers the promise of preventing unwanted pregnancy in adolescents, with its all too frequent tragic health and social consequences.

  15. Sex allocation and secondary sex ratio in Cuban boa (Chilabothrus angulifer): mother's body size affects the ratio between sons and daughters.

    PubMed

    Frynta, Daniel; Vejvodová, Tereza; Šimková, Olga

    2016-06-01

    Secondary sex ratios of animals with genetically determined sex may considerably deviate from equality. These deviations may be attributed to several proximate and ultimate factors. Sex ratio theory explains some of them as strategic decisions of mothers improving their fitness by selective investment in sons or daughters, e.g. local resource competition hypothesis (LRC) suggests that philopatric females tend to produce litters with male-biased sex ratios to avoid future competition with their daughters. Until now, only little attention has been paid to examine predictions of sex ratio theory in snakes possessing genetic sex determination and exhibiting large variance in allocation of maternal investment. Cuban boa is an endemic viviparous snake producing large-bodied newborns (∼200 g). Extremely high maternal investment in each offspring increases importance of sex allocation. In a captive colony, we collected breeding records of 42 mothers, 62 litters and 306 newborns and examined secondary sex ratios (SR) and sexual size dimorphism (SSD) of newborns. None of the examined morphometric traits of neonates appeared sexually dimorphic. The sex ratio was slightly male biased (174 males versus 132 females) and litter sex ratio significantly decreased with female snout-vent length. We interpret this relationship as an additional support for LRC as competition between mothers and daughters increases with similarity of body sizes between competing snakes.

  16. Sex allocation and secondary sex ratio in Cuban boa ( Chilabothrus angulifer): mother's body size affects the ratio between sons and daughters

    NASA Astrophysics Data System (ADS)

    Frynta, Daniel; Vejvodová, Tereza; Šimková, Olga

    2016-06-01

    Secondary sex ratios of animals with genetically determined sex may considerably deviate from equality. These deviations may be attributed to several proximate and ultimate factors. Sex ratio theory explains some of them as strategic decisions of mothers improving their fitness by selective investment in sons or daughters, e.g. local resource competition hypothesis (LRC) suggests that philopatric females tend to produce litters with male-biased sex ratios to avoid future competition with their daughters. Until now, only little attention has been paid to examine predictions of sex ratio theory in snakes possessing genetic sex determination and exhibiting large variance in allocation of maternal investment. Cuban boa is an endemic viviparous snake producing large-bodied newborns (˜200 g). Extremely high maternal investment in each offspring increases importance of sex allocation. In a captive colony, we collected breeding records of 42 mothers, 62 litters and 306 newborns and examined secondary sex ratios (SR) and sexual size dimorphism (SSD) of newborns. None of the examined morphometric traits of neonates appeared sexually dimorphic. The sex ratio was slightly male biased (174 males versus 132 females) and litter sex ratio significantly decreased with female snout-vent length. We interpret this relationship as an additional support for LRC as competition between mothers and daughters increases with similarity of body sizes between competing snakes.

  17. Brain sex differences and hormone influences

    PubMed Central

    Tobet, Stuart; Knoll, J. Gabriel; Hartshorn, Cheryl; Aurand, Emily; Stratton, Matthew; Kumar, Pankaj; Searcy, Brian; McClellan, Kristy

    2009-01-01

    Sex differences in the nervous system come in many forms. Although a majority of sexually dimorphic characteristics in brain have been described in older animals, mechanisms that determine sexually differentiated brain characteristics often operate during critical perinatal periods. Both genetic and hormonal factors likely contribute to physiological mechanisms in development to generate the ontogeny of sexual dimorphisms in brain. Relevant mechanisms may include neurogenesis, cell migration, cell differentiation, cell death, axon guidance and synaptogenesis. On a molecular level, there are several ways to categorize factors that drive brain development. These range from the actions of transcription factors in cell nuclei that regulate the expression of genes that control cell development and differentiation, to effector molecules that directly contribute to signaling from one cell to another. In addition, several peptides or proteins in these and other categories might be referred to as “biomarkers” of sexual differentiation with undetermined functions in development or adulthood. While a majority of sex differences are revealed as a direct consequence of hormone actions, some may only be revealed following genetic or environmental disruption. Sex differences in cell positions in the developing hypothalamus, and steroid hormone influences on cell movements in vitro, suggest that cell migration may be one target for early molecular actions that impact brain development and sexual differentiation. PMID:19207813

  18. No evidence of temperature-dependent sex determination or sex-biased embryo mortality in the chicken.

    PubMed

    Collins, K E; Jordan, B J; McLendon, B L; Navara, K J; Beckstead, R B; Wilson, J L

    2013-12-01

    Skewing the sex ratio at hatch in commercial poultry would be economically beneficial to the poultry industry. The existence of temperature-dependent sex determination is uncertain in birds. This experiment investigated if incubation temperatures skew sex ratios of commercial broilers. Three incubators were each set at a hot (38.3°C), standard (37.5°C), or cool (36.7°C) single-stage incubation temperature one time over 3 trials to eliminate incubator effect as a Latin square design. Sex ratios of hatched chicks and dead embryos were monitored. In one trial, embryo weights were evaluated. The percentages of male hatched chicks did not differ based on incubation temperature (P = 0.4486; 49.5% in the hot treatment, 51.4% at standard temperature, and 49.8% in the cool treatment). The percent hatch of eggs set was lower in the hot treatment (83.6%) than the standard (93.5%) and cool (91.6%) treatments (P < 0.0001) with greater late embryonic mortality in the hot treatment (P < 0.0001); however, the sex ratio of dead embryos did not differ among treatments (P = 0.9863). Pooled data of embryo mortality found no sex-biased embryo mortality with a female/male sex ratio of 1.22:1 (χ(2) = 1.27; P = 0.2596). Embryos from the hot treatment were heavier than those from the standard treatment by d 14 of incubation and were heavier than the embryos from the cool treatment by d 9 of incubation (P < 0.0001). These data indicate that incubation temperature affects embryonic mortality and embryonic growth rate, but it does not affect the sex ratio of broiler chickens. Additionally, no evidence was found for sex-biased embryo mortality in commercial broilers even at the incubation temperatures of this study.

  19. Why have sex? The population genetics of sex and recombination.

    PubMed

    Otto, S P; Gerstein, A C

    2006-08-01

    One of the greatest puzzles in evolutionary biology is the high frequency of sexual reproduction and recombination. Given that individuals surviving to reproductive age have genomes that function in their current environment, why should they risk shuffling their genes with those of another individual? Mathematical models are especially important in developing predictions about when sex and recombination can evolve, because it is difficult to intuit the outcome of evolution with several interacting genes. Interestingly, theoretical analyses have shown that it is often quite difficult to identify conditions that favour the evolution of high rates of sex and recombination. For example, fitness interactions among genes (epistasis) can favour sex and recombination but only if such interactions are negative, relatively weak and not highly variable. One reason why an answer to the paradox of sex has been so elusive is that our models have focused unduly on populations that are infinite in size, unstructured and isolated from other species. Yet most verbal theories for sex and recombination consider a finite number of genotypes evolving in a biologically and/or physically complex world. Here, we review various hypotheses for why sex and recombination are so prevalent and discuss theoretical results indicating which of these hypotheses is most promising.

  20. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. R.; St. Clair, T. L.; Burks, H. D.; Stoakley, D. M.

    1987-01-01

    A method has been found for enhancing the melt flow of thermoplastic polyimides during processing. A high molecular weight 422 copoly(amic acid) or copolyimide was fused with approximately 0.05 to 5 pct by weight of a low molecular weight amic acid or imide additive, and this melt was studied by capillary rheometry. Excellent flow and improved composite properties on graphite resulted from the addition of a PMDA-aniline additive to LARC-TPI. Solution viscosity studies imply that amic acid additives temporarily lower molecular weight and, hence, enlarge the processing window. Thus, compositions containing the additive have a lower melt viscosity for a longer time than those unmodified.

  1. [Food additives and healthiness].

    PubMed

    Heinonen, Marina

    2014-01-01

    Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects.

  2. Seriously mentally ill women's safer sex behaviors and the theory of reasoned action.

    PubMed

    Randolph, Mary E; Pinkerton, Steven D; Somlai, Anton M; Kelly, Jeffrey A; McAuliffe, Timothy L; Gibson, Richard H; Hackl, Kristin

    2009-10-01

    Seriously mentally ill women at risk for HIV infection (n = 96) participated in structured interviews assessing sexual and substance-use behavior over a 3-month period. The majority of the women (63.5%) did not use condoms. Consistent with the theory of reasoned action, attitudes toward condom use and perceived social norms about safer sex were associated with safer sex intentions. Supplementing variables from the theory of reasoned action with safer sex self-efficacy explained additional variance in safer sex intentions. Greater safer sex intentions were related to both greater condom use and less frequent unprotected intercourse. In addition, less frequent sex after drug use and a less fatalistic outlook were associated with less frequent unprotected intercourse. Life circumstances specific to this population are particularly important to examine to improve the effectiveness of risk reduction interventions for seriously mentally ill women.

  3. The social dynamics of safe sex practices among Canadian sex industry clients.

    PubMed

    Atchison, Chris; Burnett, Patrick John

    2016-07-01

    Much of what we know about the safe sex practices of people who pay for sexual services (clients) remains firmly grounded in empirical and interpretive tendencies to overemphasise the causal link between social, cultural or individual characteristics and sexual decision-making. In this study we apply Adam Green's Bourdieu-inspired sexual fields theory to examine the ways in which safe sex practices are interdependently shaped by social, personal and interpersonal forces. Using data from 697 questionnaires and 24 semi-structured interviews with Canadian clients, we implemented a series of six additive logistic regression models and contextualised the results with the interview data to reveal the relational interdependencies of intra-psychic, macro, meso and micro-level factors related to safe sex practices. The questionnaire responses and interview data used in the study were gathered from a diverse sample of clients who were over the age of 19, had paid money for sexual services on one or more occasions during their lifetime and who resided in Canada at the time of participation. Our results illustrate the ways in which factors related to the venue where sexual acts take place, clients' relationships with commercial and non-commercial partners and personal choices related to substance use interdependently inform safe sex practices.

  4. Cytogenetic comparison of heteromorphic and homomorphic sex chromosomes in Coccinia (Cucurbitaceae) points to sex chromosome turnover.

    PubMed

    Sousa, Aretuza; Fuchs, Jörg; Renner, Susanne S

    2017-03-25

    Our understanding of the evolution of plant sex chromosomes is increasing rapidly due to high-throughput sequencing data and phylogenetic and molecular-cytogenetic approaches that make it possible to infer the evolutionary direction and steps leading from homomorphic to heteromorphic sex chromosomes. Here, we focus on four species of Coccinia, a genus of 25 dioecious species, including Coccinia grandis, the species with the largest known plant Y chromosome. Based on a phylogeny for the genus, we selected three species close to C. grandis to test the distribution of eight repetitive elements including two satellites, and several plastid and mitochondrial probes, that we had previously found to have distinct accumulation patterns in the C. grandis genome. Additionally, we determined C-values and performed immunostaining experiments with (peri-)centromere-specific antibodies on two species (for comparison with C. grandis). In spite of no microscopic chromosomal heteromorphism, single pairs of chromosomes in male cells of all three species accumulate some of the very same repeats that are enriched on the C. grandis Y chromosome, pointing to either old (previous) sex chromosomes or incipient (newly arising) ones, that is, to sex chromosome turnover. A 144-bp centromeric satellite repeat (CgCent) that characterizes all C. grandis chromosomes except the Y is highly abundant in all centromeric regions of the other species, indicating that the centromeric sequence of the Y chromosome diverged very recently.

  5. Klinefelter syndrome and other sex chromosomal aneuploidies

    PubMed Central

    Visootsak, Jeannie; Graham, John M

    2006-01-01

    The term Klinefelter syndrome (KS) describes a group of chromosomal disorder in which there is at least one extra X chromosome to a normal male karyotype, 46,XY. XXY aneuploidy is the most common disorder of sex chromosomes in humans, with prevalence of one in 500 males. Other sex chromosomal aneuploidies have also been described, although they are much less frequent, with 48,XXYY and 48,XXXY being present in 1 per 17,000 to 1 per 50,000 male births. The incidence of 49,XXXXY is 1 per 85,000 to 100,000 male births. In addition, 46,XX males also exist and it is caused by translocation of Y material including sex determining region (SRY) to the X chromosome during paternal meiosis. Formal cytogenetic analysis is necessary to make a definite diagnosis, and more obvious differences in physical features tend to be associated with increasing numbers of sex chromosomes. If the diagnosis is not made prenatally, 47,XXY males may present with a variety of subtle clinical signs that are age-related. In infancy, males with 47,XXY may have chromosomal evaluations done for hypospadias, small phallus or cryptorchidism, developmental delay. The school-aged child may present with language delay, learning disabilities, or behavioral problems. The older child or adolescent may be discovered during an endocrine evaluation for delayed or incomplete pubertal development with eunuchoid body habitus, gynecomastia, and small testes. Adults are often evaluated for infertility or breast malignancy. Androgen replacement therapy should begin at puberty, around age 12 years, in increasing dosage sufficient to maintain age appropriate serum concentrations of testosterone, estradiol, follicle stimulating hormone (FSH), and luteinizing hormone (LH). The effects on physical and cognitive development increase with the number of extra Xs, and each extra X is associated with an intelligence quotient (IQ) decrease of approximately 15–16 points, with language most affected, particularly expressive

  6. The Struggle against Sex Discrimination.

    ERIC Educational Resources Information Center

    Williamson, Jane

    1982-01-01

    Provides overview of laws, policies, and regulations available to women to secure their job rights when faced with sex discrimination. Equal pay, sexual harassment, pregnancy discrimination, and affirmative action are discussed, noting procedures involved in filing a complaint. (EJS)

  7. Disentangling the Benefits of Sex

    PubMed Central

    Roze, Denis

    2012-01-01

    Understanding the evolutionary advantage of sexual reproduction remains one of the most fundamental questions in evolutionary biology. Most of the current hypotheses rely on the fact that sex increases genetic variation, thereby enhancing the efficiency of natural selection; an important body of theoretical work has defined the conditions under which sex can be favoured through this effect. Over the last decade, experimental evolution in model organisms has provided evidence that sex indeed allows faster rates of adaptation. A new study on facultatively sexual rotifers shows that increased rates of sex can be favoured during adaptation to new environmental conditions and explores the cause of this effect. The results provide support for the idea that the benefits of increasing genetic variation may compensate for the short-term costs of sexual reproduction. PMID:22563302

  8. Sex and Sexuality and HIV

    MedlinePlus

    ... Diet and Nutrition Discrimination Drugs and Alcohol Exercise Mental Health Sex and Sexuality Smoking FAQs Tips and Tools Community For Health Care Providers Provider Home Policies and Reports Provider Education Provider Education Home HIV Meds Updates Online Courses ( ...

  9. Same-Sex Partner Bereavement.

    PubMed

    Patlamazoglou, Lefteris; Simmonds, Janette G; Snell, Tristan L

    2017-01-01

    The experience of same-sex-attracted people who have lost a partner is neglected in the existing literature on bereavement. Previous research on lesbian, gay, bisexual, transgender, intersex, queer and questioning (LGBTIQ) populations tends to focus on the loss of a partner to HIV-related causes, and there is scant research concerning non-HIV-related bereavement. The purpose of this article is to investigate the non-HIV-related bereavement experiences of same-sex partners and to address the potential complications of disenfranchised grief. Coping with the loss of a same-sex partner and the impact of bereavement on subsequent relationships are also discussed. Implications for counseling of bereaved same-sex-attracted individuals are drawn, and recommendations for future psychological research on the experience of bereavement are made.

  10. Disentangling the benefits of sex.

    PubMed

    Roze, Denis

    2012-01-01

    Understanding the evolutionary advantage of sexual reproduction remains one of the most fundamental questions in evolutionary biology. Most of the current hypotheses rely on the fact that sex increases genetic variation, thereby enhancing the efficiency of natural selection; an important body of theoretical work has defined the conditions under which sex can be favoured through this effect. Over the last decade, experimental evolution in model organisms has provided evidence that sex indeed allows faster rates of adaptation. A new study on facultatively sexual rotifers shows that increased rates of sex can be favoured during adaptation to new environmental conditions and explores the cause of this effect. The results provide support for the idea that the benefits of increasing genetic variation may compensate for the short-term costs of sexual reproduction.

  11. Classifying sex biased congenital anomalies

    SciTech Connect

    Lubinsky, M.S.

    1997-03-31

    The reasons for sex biases in congenital anomalies that arise before structural or hormonal dimorphisms are established has long been unclear. A review of such disorders shows that patterning and tissue anomalies are female biased, and structural findings are more common in males. This suggests different gender dependent susceptibilities to developmental disturbances, with female vulnerabilities focused on early blastogenesis/determination, while males are more likely to involve later organogenesis/morphogenesis. A dual origin for some anomalies explains paradoxical reductions of sex biases with greater severity (i.e., multiple rather than single malformations), presumably as more severe events increase the involvement of an otherwise minor process with opposite biases to those of the primary mechanism. The cause for these sex differences is unknown, but early dimorphisms, such as differences in growth or presence of H-Y antigen, may be responsible. This model provides a useful rationale for understanding and classifying sex-biased congenital anomalies. 42 refs., 7 tabs.

  12. Sex and Violence in Neuroscience.

    ERIC Educational Resources Information Center

    Barnes, Deborah M.

    1988-01-01

    Describes advances made in the understanding of how sex hormones may modify various cognitive skills, how normal brain signaling mechanisms may cause nerve cell death, and how many cells appear to hold genetic agents which determine their own destruction. (RT)

  13. People with Intellectual Disabilities Talk About Sexuality: Implications for the Development of Sex Education.

    PubMed

    Schaafsma, D; Kok, G; Stoffelen, J M T; Curfs, L M G

    2017-01-01

    Existing sex education programmes have failed in involving people with intellectual disabilities in the development of these programmes. Not involving the target population decreases the likelihood that the sex education programme will be effective. This study was conducted to assess the perspectives of people with intellectual disabilities on several sexuality-related topics. Semi-structured interviews were held with 20 people with intellectual disabilities covering topics such as: sex education, relationships, sex, social media, parenthood and support. The reported frequency of sex education the participants receive is low. Their knowledge regarding sex education is mainly limited to topics such as safe sex, contraception and STI's and tends to be superficial. Additionally, knowledge on safe sex does not always translate to safe sex behaviour. Finally, relationships are important for most participants; mainly because they don't want to be alone. Findings from both this study and literature shows that there seems to be a need for high quality sex education. Topics to consider to include are: online relationships, social media and parenthood. It would also be beneficial to focus on sexuality-related skills. Finally, to increase the effectiveness of a sex education programme, it is advisable that a theory-and evidence-based framework, such as Intervention Mapping, is used for its development.

  14. Comparative mapping reveals autosomal origin of sex chromosome in octoploid Fragaria virginiana.

    PubMed

    Spigler, Rachel B; Lewers, Kim S; Johnson, Anna L; Ashman, Tia-Lynn

    2010-01-01

    Recent evolution of separate sexes in flowering plants provides unparalleled opportunities for understanding the early stages of sex chromosome evolution, including their origin from autosomes. Moreover, the transition from combined to separate sexes can be associated with speciation via polyploidization in angiosperms, suggesting that genome doubling/merger may facilitate sterility mutations required for sex chromosome formation. To gain insight into the origin of sex chromosomes in a polyploid plant, we doubled the simple sequence repeat (SSR) density and increased genome coverage in a genetic map of octoploid Fragaria virginiana, a species purported to have a "proto-sex" chromosome, where limited recombination occurs between 2 linked "loci" carrying the male- and female-sterility mutations. Incorporation of almost 3 times the number of SSR markers into the current map facilitated complete characterization of the F. virginiana proto-sex chromosome, revealing its largely autosomal nature and the location of the sex-determining region toward the distal end. Furthermore, extensive synteny between our genetic map and a map involving diploid hermaphroditic congeners allowed assignment of linkage groups to homeologous groups, identification of the proto-sex chromosome's autosomal homoeolog, and detection of a putative rearrangement near the sex-determining region. Fine mapping and additional comparative work will shed light on the intriguing possibility that rearrangements during polyploidization were involved in the evolution of sex chromosomes in Fragaria.

  15. Androgen and the development of human sex-typical behavior: rough-and-tumble play and sex of preferred playmates in children with congenital adrenal hyperplasia (CAH).

    PubMed

    Hines, M; Kaufman, F R

    1994-08-01

    We hypothesized that girls with congenital adrenal hyperplasia (CAH), who experience higher than normal levels of androgens prenatally, would show masculinization of behaviors that show sex differences. Therefore, we examined rough-and-tumble play and sex of preferred playmates in 3-8-year-old children with CAH and in unaffected 3-8-year-old male and female relatives. The hypothesized sex differences in rough-and-tumble play were seen, with unaffected boys showing more rough-and-tumble play than unaffected girls. However, CAH girls were similar to unaffected girls. Additionally, CAH boys showed reduced rough-and-tumble play. In contrast, sex of preferred playmates showed the hypothesized pattern of results. There were sex differences, with unaffected boys preferring boys and unaffected girls preferring girls. In addition, the preferences of girls with CAH were masculinized compared to those of unaffected girls. Results are discussed in terms of possible influences of social, hormonal, and illness factors.

  16. AIDS, mobility and commercial sex in Ethiopia: Implications for policy.

    PubMed

    Van Blerk, L

    2007-01-01

    Since the emergence of the AIDS pandemic in sub-Saharan Africa, male mobility has been highlighted as one of the reasons for the spread of the disease with men employing the services of commercial sex workers while away from home. However, sex workers' mobility and the implications of this for their access to prevention services, has largely been ignored. This paper, based on multi-method qualitative research with 60 young sex workers in two Ethiopian towns, reveals that sex workers are highly mobile, moving in order to attract a wider or different client base, for adventure and to conceal illnesses which might be associated with AIDS. In addition, sex workers are affected by restrictions on their movements, with girls working in bars and red-light areas having little free time to access projects. This paper advocates that policy approaches need to take account of this mobility in three ways: first, by exploring ways for girls to access information and maintain contact with support structures while moving between places of work; second, by building the capacity of sex workers to take greater control over decision-making in their day-to-day lives and third, by developing outreach strategies for taking services into bars and red-light areas.

  17. Storage of sexed boar spermatozoa: Limits and perspectives.

    PubMed

    Spinaci, M; Perteghella, S; Chlapanidas, T; Galeati, G; Vigo, D; Tamanini, C; Bucci, D

    2016-01-01

    Despite the great potential application of sex-sorted spermatozoa in swine, the technology is not practiced in the pig industry because of technical factors and species-specific issues. The susceptibility of boar spermatozoa to stresses induced by the sorting procedure, the relative slowness of the sex-sorting process together with the high sperm numbers required for routine artificial insemination in pig are some of the main factors limiting the commercial application of this technology in pigs. This review briefly describes the damage to spermatozoa during sex sorting, focusing on an additional limiting factor: increased susceptibility of sexed boar spermatozoa to injuries induced by liquid storage and cryopreservation that, in turn, impairs sperm quality leading to unsatisfactory results in vivo. Strategies to extend the lifespan of sex-sorted boar spermatozoa and to improve their fertilizing ability after liquid storage or cryopreservation need to be implemented before this technology can be used in pig farms. In this regard, encapsulation in barium alginate membranes could be a promising technique to optimize the in vivo use of sexed boar spermatozoa, by protecting, targeting, and controlling the release of sperm into the female genital tract.

  18. A critical review of objective personality inventories with sex offenders.

    PubMed

    Davis, Karen M; Archer, Robert P

    2010-12-01

    This review provides a critical analysis of the ability of multiscale inventories to distinguish between sex offender and nonoffender control groups, as well as to discriminate sex offenders from other types of offenders. In addition to expanding upon previous reviews that examined the utility of the Minnesota Multiphasic Personality Inventory (MMPI) with this population (e.g., Levin & Stava, 1987), the current review included studies that utilized other multiscale inventories commonly used in forensic practice (i.e., MMPI-2, Millon Clinical Multiaxial Inventory-III [MCMI-III], Personality Assessment Inventory) and, when possible, provides effect sizes to evaluate group differences. Based on the review, the various forms of the MMPI and MCMI are clearly the most widely used instruments in sex offender populations. The MMPI Pd scale has shown moderate to large effect sizes when distinguishing between sex offender and nonsex offender groups, but this relationship may be reflective of antisocial behavior in general rather than traits specific to sex offenders. Recommendations to standardize future research classification strategies and more effectively utilize these instruments when assessing sex offenders are also provided.

  19. A Review of The Sex EDcyclopedia

    ERIC Educational Resources Information Center

    Herman, Jeff; Andelloux, Megan

    2012-01-01

    While virtually all sex education books for teenagers focus on sexual health, Jo Langford's "The Sex EDcyclopedia" offers comprehensive and empowering information specifically for teen males about their sexuality and how it may be positively experienced. This review examines the strengths of "The Sex EDcyclopedia" as a sex education resource and…

  20. Polylactides in additive biomanufacturing.

    PubMed

    Poh, Patrina S P; Chhaya, Mohit P; Wunner, Felix M; De-Juan-Pardo, Elena M; Schilling, Arndt F; Schantz, Jan-Thorsten; van Griensven, Martijn; Hutmacher, Dietmar W

    2016-12-15

    New advanced manufacturing technologies under the alias of additive biomanufacturing allow the design and fabrication of a range of products from pre-operative models, cutting guides and medical devices to scaffolds. The process of printing in 3 dimensions of cells, extracellular matrix (ECM) and biomaterials (bioinks, powders, etc.) to generate in vitro and/or in vivo tissue analogue structures has been termed bioprinting. To further advance in additive biomanufacturing, there are many aspects that we can learn from the wider additive manufacturing (AM) industry, which have progressed tremendously since its introduction into the manufacturing sector. First, this review gives an overview of additive manufacturing and both industry and academia efforts in addressing specific challenges in the AM technologies to drive toward AM-enabled industrial revolution. After which, considerations of poly(lactides) as a biomaterial in additive biomanufacturing are discussed. Challenges in wider additive biomanufacturing field are discussed in terms of (a) biomaterials; (b) computer-aided design, engineering and manufacturing; (c) AM and additive biomanufacturing printers hardware; and (d) system integration. Finally, the outlook for additive biomanufacturing was discussed.

  1. Additive Manufactured Product Integrity

    NASA Technical Reports Server (NTRS)

    Waller, Jess; Wells, Doug; James, Steve; Nichols, Charles

    2017-01-01

    NASA is providing key leadership in an international effort linking NASA and non-NASA resources to speed adoption of additive manufacturing (AM) to meet NASA's mission goals. Participants include industry, NASA's space partners, other government agencies, standards organizations and academia. Nondestructive Evaluation (NDE) is identified as a universal need for all aspects of additive manufacturing.

  2. Signatures of Sex-Antagonistic Selection on Recombining Sex Chromosomes

    PubMed Central

    Kirkpatrick, Mark; Guerrero, Rafael F.

    2014-01-01

    Sex-antagonistic (SA) selection has major evolutionary consequences: it can drive genomic change, constrain adaptation, and maintain genetic variation for fitness. The recombining (or pseudoautosomal) regions of sex chromosomes are a promising setting in which to study SA selection because they tend to accumulate SA polymorphisms and because recombination allows us to deploy the tools of molecular evolution to locate targets of SA selection and quantify evolutionary forces. Here we use coalescent models to characterize the patterns of polymorphism expected within and divergence between recombining X and Y (or Z and W) sex chromosomes. SA selection generates peaks of divergence between X and Y that can extend substantial distances away from the targets of selection. Linkage disequilibrium between neutral sites is also inflated. We show how the pattern of divergence is altered when the SA polymorphism or the sex-determining region was recently established. We use data from the flowering plant Silene latifolia to illustrate how the strength of SA selection might be quantified using molecular data from recombining sex chromosomes. PMID:24578352

  3. Teen counselors succeed where sex-ed classes fail.

    PubMed

    Rodrigue, G

    1995-01-25

    In Georgia, in the US, students who take part in a sex education program for eighth-graders called "Postponing Sexual Involvement" are 5-15 times less likely than their peers to start having sex in the ninth grade. In the US, 30% of babies born are born to unwed mothers, and 80% of the children born to unwed high-school dropouts grow up in poverty. This fact takes a great toll on the children and on society. The new sex education program began when its director, Dr. Marion Howard, realized that the traditional method of disseminating birth control information in sex education classes resulted in students acquiring a great deal of knowledge about contraception but not using it. She then noted the success of an antismoking program which used older teenagers as role models, and she learned that the young mothers wanted to know how to say no to sex without hurting a boyfriend's feelings. The new program, which reaches all eighth graders in Atlanta, begins with discussions of anatomy and contraception and then focuses on the risks of sexual activity, sexual pressures in society, and peer pressure. Older teenagers help the students discuss some of the "lines" that boys and girls use to pressure each other and help the students practice how to resist this pressure. Both the students and the teen counselors have benefitted from their involvement with this course.

  4. Signatures of sex-antagonistic selection on recombining sex chromosomes.

    PubMed

    Kirkpatrick, Mark; Guerrero, Rafael F

    2014-06-01

    Sex-antagonistic (SA) selection has major evolutionary consequences: it can drive genomic change, constrain adaptation, and maintain genetic variation for fitness. The recombining (or pseudoautosomal) regions of sex chromosomes are a promising setting in which to study SA selection because they tend to accumulate SA polymorphisms and because recombination allows us to deploy the tools of molecular evolution to locate targets of SA selection and quantify evolutionary forces. Here we use coalescent models to characterize the patterns of polymorphism expected within and divergence between recombining X and Y (or Z and W) sex chromosomes. SA selection generates peaks of divergence between X and Y that can extend substantial distances away from the targets of selection. Linkage disequilibrium between neutral sites is also inflated. We show how the pattern of divergence is altered when the SA polymorphism or the sex-determining region was recently established. We use data from the flowering plant Silene latifolia to illustrate how the strength of SA selection might be quantified using molecular data from recombining sex chromosomes.

  5. Genomic characterization of sex-identification markers in Sebastes carnatus and Sebastes chrysomelas rockfishes.

    PubMed

    Fowler, Benjamin L S; Buonaccorsi, Vincent P

    2016-05-01

    Fish have evolved a variety of sex-determining (SD) systems including male heterogamy (XY), female heterogamy (ZW) and environmental SD. Little is known about SD mechanisms of Sebastes rockfishes, a highly speciose genus of importance to evolutionary and conservation biology. Here, we characterize the sex determination system in the sympatrically distributed sister species Sebastes chrysomelas and Sebastes carnatus. To identify sex-specific genotypic markers, double digest restriction site - associated DNA sequencing (ddRAD-seq) of genomic DNA from 40 sexed individuals of both species was performed. Loci were filtered for presence in all of the individuals of one sex, absence in the other sex and no heterozygosity. Of the 74 965 loci present in all males, 33 male-specific loci met the criteria in at least one species and 17 in both. Conversely, no female-specific loci were detected, together providing evidence of an XY sex determination system in both species. When aligned to a draft reference genome from Sebastes aleutianus, 26 sex-specific loci were interspersed among 1168 loci that were identical between sexes. The nascent Y chromosome averaged 5% divergence from the X chromosome and mapped to reference Sebastes genome scaffolds totalling 6.9Mbp in length. These scaffolds aligned to a single chromosome in three model fish genomes. Read coverage differences were also detected between sex-specific and autosomal loci. A PCR-RFLP assay validated the bioinformatic results and correctly identified sex of five additional individuals of known sex. A sex-determining gene in other teleosts gonadal soma-derived factor (gsdf) was present in the model fish chromosomes that spanned our sex-specific markers.

  6. Nuclear genes with sex bias in Ruditapes philippinarum (Bivalvia, veneridae): Mitochondrial inheritance and sex determination in DUI species.

    PubMed

    Milani, Liliana; Ghiselli, Fabrizio; Nuzhdin, Sergey V; Passamonti, Marco

    2013-11-01

    Mitochondria are inherited maternally in most metazoans, but in bivalves with Doubly Uniparental Inheritance (DUI) a mitochondrial lineage is transmitted through eggs (F-type), and another through sperm (M-type). In DUI species, a sex-ratio distortion of the progeny was observed: some females produce a female-biased offspring (female-biased family), others a male-biased progeny (male-biased family), and others a 50:50 sex-ratio. A peculiar segregation pattern of M-type mitochondria in DUI organisms appears to be correlated with the sex bias of these families. According to a proposed model for the inheritance of M-type mitochondria in DUI, the transmission of sperm mitochondria is controlled by three nuclear genes, named W, X, and Z. An additional S gene with different dosage effect would be involved in sex determination. In this study, we analyzed structure and localization of three transcripts (psa, birc, and anubl1) with specific sex and family biases in the Manila clam Ruditapes philippinarum. In situ hybridization confirmed the localization of these transcripts in gametogenic cells. In other animals, homologs of these genes are involved in reproduction and ubiquitination. We hypothesized that these genes may have a role in sex determination and could also be responsible for the maintenance/degradation of spermatozoon mitochondria during embryo development of the DUI species R. philippinarum, so that we propose them as candidate factors of the W/X/Z/S system.

  7. Online Sex-Seeking Among Men who have Sex with Men in Nigeria: Implications for Online Intervention.

    PubMed

    Stahlman, Shauna; Nowak, Rebecca G; Liu, Hongjie; Crowell, Trevor A; Ketende, Sosthenes; Blattner, William A; Charurat, Manhattan E; Baral, Stefan D

    2016-05-27

    The TRUST/RV368 project was undertaken to apply innovative strategies to engage Nigerian MSM into HIV care. In this analysis we evaluate characteristics of online sex-seekers from the TRUST/RV368 cohort of 1370 MSM in Abuja and Lagos. Logistic regression and generalized estimating equation models were used to assess associations with online sex-seeking. Online sex-seeking (n = 843, 61.5 %) was associated with participation in MSM community activities, larger social and sexual networks, and higher levels of sexual behavior stigma. In addition, online sex-seeking was associated with testing positive for HIV at a follow-up visit [adjusted odds ratio (aOR) = 2.02, 95 % confidence interval (CI) = 1.37, 2.98)] among those who were unaware of or not living with HIV at baseline. Across visits, online sex-seekers were marginally more likely to test positive for chlamydia/gonorrhea (aOR 1.28, 95 % CI 0.99, 1.64). Online sex-seekers in Nigeria are at increased risk for HIV/STIs but may not be benefiting from Internet-based risk reduction opportunities.

  8. Creating comprehensive, youth centered, culturally appropriate sex education: What do young gay, bisexual and questioning men want?

    PubMed

    Pingel, Emily Sweetnam; Thomas, Laura; Harmell, Chelsea; Bauermeister, José

    2013-12-01

    We examined young gay, bisexual and questioning men's (YGBQM) experiences with school-based sex education as they sought to learn about sex and sexual health, and their suggestions for improving same-sex education resources. Thematic analysis of 30 in-depth interviews with YGBQM (ages 18-24) underscored the discrepancies between the existing school-based sex education curricula and YGBQM's perceived sex education needs. Our results show that many youths' sexuality and same-sex sexual behaviors are excluded in sex education lessons; however, YGBQM noted that they sought out other resources (e.g., websites) to answer their questions. We discuss YGBQM's ideas for the creation of a sex and sexual health website that would be tailored for youth like themselves, including topics and features that an ideal website would contain. In addition, we present recommended changes to existing school-based sexual education curricula.

  9. Meanings of sex, concepts of risk and sexual practices among migrant coal miners in Quang Ninh, Vietnam.

    PubMed

    Van Tuan, Ta

    2010-08-01

    The study explores the meanings of sex among migrant coal miners in Vietnam and identifies contextual factors influencing engagement in unsafe sexual practices. Findings reveal that sex carries a number of social meanings in the lives of migrant miners: sex is relaxation and reward for their risk and hard work; access to sex is an incentive for miners to continue working in the mine; sex strengthens identity and social networks; sex helps miners to affirm manhood, group membership and masculinity; and sex workers are confidants with whom they can share their problems. Facing accidents at work on a daily basis, miners are less inclined to worry about the long-term risks of HIV infection. In addition, being excluded from access to relevant information, miners feel distant from HIV infection. Findings suggest that interventions on sexual behaviour and practices should be sensitive to the concepts of risk and meanings of sex among migrant groups such as coal miners.

  10. Incarcerated Dutch Juvenile Sex Offenders Compared with Non-Sex Offenders

    ERIC Educational Resources Information Center

    van Wijk, Anton Ph.; Vreugdenhil, Coby; van Horn, Joan; Vermeiren, Robert; Doreleijers, Theo A. H.

    2007-01-01

    There is some debate about whether or not sex offenders are similar to non-sex offenders with regard to family background (parental characteristics), personality, and psychopathology. The central aim of this study focused on the comparison of juvenile sex offenders and non-sex offenders. The sample consisted of incarcerated juvenile male sex (n =…

  11. The Stability of Same-Sex Cohabitation, Different-Sex Cohabitation, and Marriage

    ERIC Educational Resources Information Center

    Lau, Charles Q.

    2012-01-01

    This study contributes to the emerging demographic literature on same-sex couples by comparing the level and correlates of union stability among 4 types of couples: (a) male same-sex cohabitation, (b) female same-sex cohabitation, (c) different-sex cohabitation, and (d) different-sex marriage. The author analyzed data from 2 British birth cohort…

  12. Tackling the diversity of sex determination.

    PubMed

    Wedekind, Claus; Stelkens, Rike B

    2010-02-23

    A workshop on 'The evolution of sex determination systems' was held at a remote place in the Swiss Alps from 17 to 20 June 2009. It brought together theoreticians and empiricists, the latter ranging from molecular geneticists to evolutionary ecologists, all trying to understand key aspects of sex determination. The topics discussed included the evolutionary origins of sex determination, the diversity of sex determination mechanisms in different taxa, and the transition from genotypic to environmental sex determination and vice versa.

  13. Recognize sex work as legitimate work.

    PubMed

    Reynaga, Elena

    2008-12-01

    It is not sex work per se that makes sex workers vulnerable to HIV, but rather the policies that repress them. In this article, based on her presentation at a plenary session at the conference, Elena Reynaga, who is a sex worker, describes how these policies deprive sex workers of their rights and subject them to physical and sexual violence. The author concludes that at the heart of the problem lies the fact that sex work is not recognized as legitimate work.

  14. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Fletcher, James C. (Inventor); Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1992-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  15. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1993-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of the additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  16. Simulation Gaming--A Device for Altering Attitudes about Sex Roles.

    ERIC Educational Resources Information Center

    Hall, Eleanor G.

    1979-01-01

    The article explores the value of simulation gaming for changing attitudes of gifted students concerning sex roles. Simulation gaming has considerable potential for reducing, altering, and changing attitudes concerning sex role limitations, since gaming involves devising plans and motivating appeals, in addition to role playing, negotiating,…

  17. On Reconstructing School Segregation: The Efficacy and Equity of Single-Sex Schooling

    ERIC Educational Resources Information Center

    Billger, Sherrilyn M.

    2009-01-01

    A change to Title IX has spurred new single-sex public schooling in the US. Until recently, nearly all gender-segregated schools were private, and comprehensive data for public school comparisons are not yet available. To investigate the effects of single-sex education, I focus on within private sector comparisons, and additionally address…

  18. Neural activation during anticipation of opposite-sex and same-sex faces in heterosexual men and women.

    PubMed

    Spreckelmeyer, Katja N; Rademacher, Lena; Paulus, Frieder M; Gründer, Gerhard

    2013-02-01

    Psychobiological accounts of face processing predict that greater salience is attributed to faces matching a viewer's sexual preference than to faces that do not. However, behaviorally, this effect could only be demonstrated in tasks assessing reward 'wanting' (e.g. work-per-view-tasks) but not in tasks assessing 'liking' (e.g. facial attractiveness ratings), and has been found to be more pronounced in heterosexual men than women, especially with regard to very attractive faces. Here, we addressed the question if sex differences at the level of 'wanting' persist if participants are uninformed about the attractiveness of an anticipated male or female face. Seventeen heterosexual men and 13 heterosexual women (all single) participated in a social incentive delay task (SID). Participants were required to react on simple graphical cues in order to view a smiling face. Cues provided a priori information on the level of smile intensity (low/medium/high) as well as sex of the face (male/ female). A significant interaction of sex-of-face and sex-of-participant was observed in a priori defined regions of interest in the brain reward system (including ventral tegmental area, nucleus accumbens and ventromedial prefrontal cortex), reflecting enhanced activation to cues signaling opposite-sex faces relative to same-sex faces in both, men and women. Women additionally recruited the temporo-parietal junction (TPJ) during processing of opposite- vs. same-sex cues, suggesting stronger incorporation of social cognition processes in women than men. The findings speak against a general male bias for opposite-sex faces. Instead they provide preliminary evidence that men and women recruit different brain circuits during reward value assessment of facial stimuli.

  19. Female-only sex-linked amplified fragment length polymorphism markers support ZW/ZZ sex determination in the giant freshwater prawn Macrobrachium rosenbergii.

    PubMed

    Jiang, Xue-Hui; Qiu, Gao-Feng

    2013-12-01

    Sex determination mechanisms in many crustacean species are complex and poorly documented. In the giant freshwater prawn, Macrobrachium rosenbergii, a ZW/ZZ sex determination system was previously proposed based on sex ratio data obtained by crosses of sex-reversed females (neomales). To provide molecular evidence for the proposed system, novel sex-linked molecular markers were isolated in this species. Amplified fragment length polymorphism (AFLP) using 64 primer combinations was employed to screen prawn genomes for DNA markers linked with sex loci. Approximately 8400 legible fragments were produced, 13 of which were uniquely identified in female prawns with no indication of corresponding male-specific markers. These AFLP fragments were reamplified, cloned and sequenced, producing two reliable female-specific sequence characterized amplified region (SCAR) markers. Additional individuals from two unrelated geographic populations were used to verify these findings, confirming female-specific amplification of single bands. Detection of internal polymorphic sites was conducted by designing new primer pairs based on these internal fragments. The internal SCAR fragments also displayed specificity in females, indicating high levels of variation between female and male specimens. The distinctive feature of female-linked SCAR markers can be applied for rapid detection of prawn gender. These sex-specific SCAR markers and sex-associated AFLP candidates unique to female specimens support a sex determination system consistent with female heterogamety (ZW) and male homogamety (ZZ).

  20. Food Additives and Hyperkinesis

    ERIC Educational Resources Information Center

    Wender, Ester H.

    1977-01-01

    The hypothesis that food additives are causally associated with hyperkinesis and learning disabilities in children is reviewed, and available data are summarized. Available from: American Medical Association 535 North Dearborn Street Chicago, Illinois 60610. (JG)

  1. Smog control fuel additives

    SciTech Connect

    Lundby, W.

    1993-06-29

    A method is described of controlling, reducing or eliminating, ozone and related smog resulting from photochemical reactions between ozone and automotive or industrial gases comprising the addition of iodine or compounds of iodine to hydrocarbon-base fuels prior to or during combustion in an amount of about 1 part iodine per 240 to 10,000,000 parts fuel, by weight, to be accomplished by: (a) the addition of these inhibitors during or after the refining or manufacturing process of liquid fuels; (b) the production of these inhibitors for addition into fuel tanks, such as automotive or industrial tanks; or (c) the addition of these inhibitors into combustion chambers of equipment utilizing solid fuels for the purpose of reducing ozone.

  2. The Collateral Consequences of Sex Offender Management Policies: Views From Professionals.

    PubMed

    Call, Corey

    2016-06-13

    In this study, the perceptions of community corrections professionals and clinical specialists toward the collateral consequences of current sex offender management policies were explored and contrasted. In addition, potential influencing factors of these perceptions were examined. Results indicate high levels of belief that sex offenders experience a variety of collateral consequences upon reentry; however, community corrections professionals are significantly less likely to believe that sex offenders experience collateral consequences than clinical specialists. Furthermore, few demographic variables were found to significantly influence the perceptions of the sample. Implications for the management of sex offenders are discussed.

  3. Family Experiences of Young Adult Sex Offender Registration

    ERIC Educational Resources Information Center

    Comartin, Erin B.; Kernsmith, Poco D.; Miles, Bart W.

    2010-01-01

    Since 1994, policies have been instituted throughout the United States that require sex offenders to register their personal information with law enforcement officials (Jacob Wetterling Crimes against Children and Sexually Violent Offender Registration Program, 1994). With the passage of additional laws, this information is now available to the…

  4. Sex Education for Deaf-Blind Youths and Adults.

    ERIC Educational Resources Information Center

    Ingraham, Cynthia L.; Vernon, McCay; Clemente, Brenda; Olney, Linda

    2000-01-01

    This article describes a model sex education program developed for youths and adults who are deafblind by the Helen Keller National Center for Deaf-Blind Youths and Adults. In addition, it also discusses major related issues and presents general recommendations and a resource for further information. (Contains 11 references.) (Author/CR)

  5. Sex determination using maxillary sinus

    PubMed Central

    Kanthem, Ranjith Kumar; Guttikonda, Venkateswara Rao; Yeluri, Sivaranjani; Kumari, Geetha

    2015-01-01

    Background: Individual identification is a subtle concept and often one of the most important priorities in mass disasters, road accidents, air crashes, fires, and even in the investigation of criminal cases. Matching specific features detected on the cadaver with data recorded during the life of an individual is an important aspect in forensics, and can be performed by fingerprint analysis, deoxyribonucleic acid matching, anthropological methods, radiological methods and other techniques which can facilitate age and sex identification. Sinus radiography is one such method that has been used for determination of the sex of an individual. Hence, an attempt is being made to use the different dimensions of the maxillary sinus in the determination of sex using coronal and axial sections of plain computed tomography (CT) scan. Materials and Methods: A total of 30 patients including 17 male and 13 female, visiting the Outpatient Department of the Mamata General Hospital were included as the study subjects. The dimensions of right and left maxillary sinuses of 30 subjects from plain CT were measured using SYNGO software and statistical analysis was done. Results: Sex determination using height, length, width, and volume of the maxillary sinus on both sides showed statistically significant results with a higher percentage of sexual dimorphism in the case of volume. Conclusion: Volume of the right maxillary sinus can be used as accurate diagnostic parameter for sex determination. PMID:26005308

  6. Sex differences in nicotine action.

    PubMed

    Pogun, Sakire; Yararbas, Gorkem

    2009-01-01

    Accumulating evidence suggests that the antecedents, consequences, and mechanisms of drug abuse and dependence are not identical in males and females and that gender may be an important variable in treatment and prevention. Although there has been a decline in smoking prevalence in developed countries, females are less successful in quitting. Tobacco use is accepted to be a form of addiction, which manifests sex differences. There is also evidence for sex differences in the central effects of nicotine in laboratory animals. Although social factors impact smoking substantially in humans, findings from nonhuman subjects in controlled experiments provide support that sex differences in nicotine/tobacco addiction have a biological basis. Differences in the pharmacokinetic properties of nicotine or the effect of gonadal hormones may underlie some but not all sex differences observed. Laboratory-based information is very important in developing treatment strategies. Literature findings suggest that including sex as a factor in nicotine/tobacco-related studies will improve our success rates in individually tailored smoking cessation programs.

  7. Sex work: a comparative study.

    PubMed

    McCarthy, Bill; Benoit, Cecilia; Jansson, Mikael

    2014-10-01

    Explanations of adult involvement in sex work typically adopt one of two approaches. One perspective highlights a variety of negative experiences in childhood and adolescence, including physical and sexual abuse, family instability, poverty, associations with "pimps" and other exploiters, homelessness, and drug use. An alternative account recognizes that some of these factors may be involved, but underscores the contribution of more immediate circumstances, such as current economic needs, human capital, and employment opportunities. Prior research offers a limited assessment of these contrasting claims: most studies have focused exclusively on people working in the sex industry and they have not assessed the independent effects of life course variables central to these two perspectives. We add to this literature with an analysis that drew on insights from life course and life-span development theories and considered the contributions of factors from childhood, adolescence, and adulthood. Our comparative approach examined predictors of employment in sex work relative to two other low-income service or care work occupations: food and beverage serving and barbering and hairstyling. Using data from a study of almost 600 workers from two cities, one in Canada and the other in the United States, we found that both immediate circumstances and negative experiences from early life are related to current sex work involvement: childhood poverty, abuse, and family instability were independently associated with adult sex work, as were limited education and employment experience, adult drug use, and marital status.

  8. Sex, gender, genetics, and health.

    PubMed

    Short, Susan E; Yang, Yang Claire; Jenkins, Tania M

    2013-10-01

    This article addresses 2 questions. First, to what extent are sex and gender incorporated into research on genetics and health? Second, how might social science understandings of sex and gender, and gender differences in health, become more integrated into scholarship in this area? We review articles on genetics and health published in selected peer-reviewed journals. Although sex is included frequently as a control or stratifying variable, few articles articulate a conceptual frame or methodological justification for conducting research in this way, and most are not motivated by sex or gender differences in health. Gender differences in health are persistent, unexplained, and shaped by multilevel social factors. Future scholarship on genetics and health needs to incorporate more systematic attention to sex and gender, gender as an environment, and the intertwining of social and biological variation over the life course. Such integration will advance understandings of gender differences in health, and may yield insight regarding the processes and circumstances that make genomic variation relevant for health and well-being.

  9. [Pre-conception sex selection].

    PubMed

    Julesz, Máté

    2014-11-16

    According to Article 14 of the Oviedo Convention on Human Rights and Biomedicine of the Council of Europe, the use of techniques of medically assisted procreation shall not be allowed for the purpose of choosing the sex of a future child, unless serious hereditary sex-related disease is to be avoided. In Israel and the United States of America, pre-conception sex selection for the purpose of family balancing is legal. The European health culture does not regard reproductive justice as part of social justice. From this aspect, the situation is very similar in China and India. Reproductive liberty is opposed by the Catholic Church, too. According to the Catholic Church, medical grounds may not justify pre-conception sex selection, though being bioethically less harmful than family balancing for social reasons. In Hungary, according to Section 170 of the Criminal Code, pre-conception sex selection for the purpose of family balancing constitutes a crime. At present, the Hungarian legislation is in full harmony with the Oviedo Convention, enacted in Hungary in 2002.

  10. Same-sex cohabitors and health: the role of race-ethnicity, gender, and socioeconomic status.

    PubMed

    Liu, Hui; Reczek, Corinne; Brown, Dustin

    2013-03-01

    A legacy of research finds that marriage is associated with good health. Yet same-sex cohabitors cannot marry in most states in the United States and therefore may not receive the health benefits associated with marriage. We use pooled data from the 1997 to 2009 National Health Interview Surveys to compare the self-rated health of same-sex cohabiting men (n = 1,659) and same-sex cohabiting women (n = 1,634) with that of their different-sex married, different-sex cohabiting, and unpartnered divorced, widowed, and never-married counterparts. Results from logistic regression models show that same-sex cohabitors report poorer health than their different-sex married counterparts at the same levels of socioeconomic status. Additionally, same-sex cohabitors report better health than their different-sex cohabiting and single counterparts, but these differences are fully explained by socioeconomic status. Without their socioeconomic advantages, same-sex cohabitors would report similar health to nonmarried groups. Analyses further reveal important racial-ethnic and gender variations.

  11. Experimental demonstration that pre- and post-conceptional mechanisms influence sex ratio in mouse embryos.

    PubMed

    Jiménez, Adela; Fernández, Raúl; Madrid-Bury, Ninoska; Moreira, Pedro Nuno; Borque, Concepción; Pintado, Belén; Gutiérrez-Adán, Alfonso

    2003-10-01

    Previously we have demonstrated in two monotocous species (bovine and sheep), a relationship between time of insemination, moment of ovulation, and embryo sex ratio. Here, we have analyzed in a polytocous specie (mice) if in addition to pre-conceptional mechanisms, also post-conceptional ones affect the offspring sex ratio. To verify this hypothesis we carried out two experiments. In the first experiment, we analyzed the effect of mating dynamics on the sex ratio of mice with synchronic male and female embryo development. Females were mated before and after ovulation and sacrificed 13 days later for sex determination of embryos and reabsorptions. A decreased litter size, and an increased offspring sex ratio in matings occurring later in oestrus, supported the view that a biased sex ratio may occur as the result of behavioral differences between the populations of X- or Y-bearing spermatozoa. In the second experiment, embryos developmentally synchronic and asynchronic with the recipient female endometrium were transferred, and again, 13 days later, females were sacrificed for sex determination of embryos and reabsorptions. The male proportion per litter found, indicated that our developmentally asynchronic transfers favored a sex ratio disbalance at birth. When combined, these results become the first experimental evidence supporting the view that both pre- and post-conceptional mechanisms of sex ratio distortion in polytocous species are not mutually exclusive and both may explain, under different conditions, sex ratio deviations at birth.

  12. Autosomal gsdf acts as a male sex initiator in the fish medaka

    PubMed Central

    Zhang, Xi; Guan, Guijun; Li, Mingyou; Zhu, Feng; Liu, Qizhi; Naruse, Kiyoshi; Herpin, Amaury; Nagahama, Yoshitaka; Li, Jiale; Hong, Yunhan

    2016-01-01

    Sex is pivotal for reproduction, healthcare and evolution. In the fish medaka, the Y-chromosomal dmy (also dmrt1bY) serves the sex determiner, which activates dmrt1 for male sex maintenance. However, how dmy makes the male decision via initiating testicular differentiation has remained unknown. Here we report that autosomal gsdf serves a male sex initiator. Gene addition and deletion revealed that gsdf was necessary and sufficient for maleness via initiating testicular differentiation. We show that gsdf transcription is activated directly by dmy. These results establish the autosomal gsdf as the first male sex initiator. We propose that dmy determines maleness through activating gsdf and dmrt1 without its own participation in developmental processes of sex initiation and maintenance. gsdf may easily become a sex determiner or other autosomal genes can be recruited as new sex determiners to initiate gsdf expression. Our findings offer new insights into molecular mechanisms underlying sex development and evolution of sex-controlling genes in vertebrates. PMID:26813267

  13. Sex-based differences in brain alterations across chronic pain conditions.

    PubMed

    Gupta, Arpana; Mayer, Emeran A; Fling, Connor; Labus, Jennifer S; Naliboff, Bruce D; Hong, Jui-Yang; Kilpatrick, Lisa A

    2017-01-02

    Common brain mechanisms are thought to play a significant role across a multitude of chronic pain syndromes. In addition, there is strong evidence for the existence of sex differences in the prevalence of chronic pain and in the neurobiology of pain. Thus, it is important to consider sex when developing general principals of pain neurobiology. The goal of the current Mini-Review is to evaluate what is known about sex-specific brain alterations across multiple chronic pain populations. A total of 15 sex difference and 143 single-sex articles were identified from among 412 chronic pain neuroimaging articles. Results from sex difference studies indicate more prominent primary sensorimotor structural and functional alterations in female chronic pain patients compared with male chronic pain patients: differences in the nature and degree of insula alterations, with greater insula reactivity in male patients; differences in the degree of anterior cingulate structural alterations; and differences in emotional-arousal reactivity. Qualitative comparisons of male-specific and female-specific studies appear to be consistent with the results from sex difference studies. Given these differences, mixed-sex studies of chronic pain risk creating biased data or missing important information and single-sex studies have limited generalizability. The advent of large-scale neuroimaging databases will likely aid in building a more comprehensive understanding of sex differences and commonalities in brain mechanisms underlying chronic pain. © 2016 Wiley Periodicals, Inc.

  14. The contrasting role of heterochromatin in the differentiation of sex chromosomes: an overview from Neotropical fishes.

    PubMed

    Cioffi, M B; Moreira-Filho, O; Almeida-Toledo, L F; Bertollo, L A C

    2012-05-01

    During the evolutionary process of the sex chromosomes, a general principle that arises is that cessation or a partial restriction of recombination between the sex chromosome pair is necessary. Data from phylogenetically distinct organisms reveal that this phenomenon is frequently associated with the accumulation of heterochromatin in the sex chromosomes. Fish species emerge as excellent models to study this phenomenon because they have much younger sex chromosomes compared to higher vertebrates and many other organisms making it possible to follow their steps of differentiation. In several Neotropical fish species, the heterochromatinization, accompanied by amplification of tandem repeats, represents an important step in the morphological differentiation of simple sex chromosome systems, especially in the ZZ/ZW sex systems. In contrast, multiple sex chromosome systems have no additional increase of heterochromatin in the chromosomes. Thus, the initial stage of differentiation of the multiple sex chromosome systems seems to be associated with proper chromosomal rearrangements, whereas the simple sex chromosome systems have an accumulation of heterochromatin. In this review, attention has been drawn to this contrasting role of heterochromatin in the differentiation of simple and multiple sex chromosomes of Neotropical fishes, highlighting their surprising evolutionary dynamism.

  15. Different autosomes evolved into sex chromosomes in the sister genera of Salix and Populus.

    PubMed

    Hou, Jing; Ye, Ning; Zhang, Defang; Chen, Yingnan; Fang, Lecheng; Dai, Xiaogang; Yin, Tongming

    2015-03-13

    Willows (Salix) and poplars (Populus) are dioecious plants in Salicaceae family. Sex chromosome in poplar genome was consistently reported to be associated with chromosome XIX. In contrast to poplar, this study revealed that chromosome XV was sex chromosome in willow. Previous studies revealed that both ZZ/ZW and XX/XY sex-determining systems could be present in some species of Populus. In this study, sex of S. suchowensis was found to be determined by the ZW system in which the female was the heterogametic gender. Gene syntenic and collinear comparisons revealed macrosynteny between sex chromosomes and the corresponding autosomes between these two lineages. By contrast, no syntenic segments were found to be shared between poplar's and willow's sex chromosomes. Syntenic analysis also revealed substantial chromosome rearrangements between willow's alternate sex chromatids. Since willow and poplar originate from a common ancestor, we proposed that evolution of autosomes into sex chromosomes in these two lineages occurred after their divergence. Results of this study indicate that sex chromosomes in Salicaceae are still at the early stage of evolutionary divergence. Additionally, this study provided valuable information for better understanding the genetics and evolution of sex chromosome in dioecious plants.

  16. Head shaking in the forced swim test: A robust but unexplored sex difference.

    PubMed

    Kokras, Nikolaos; Polissidis, Alexia; Antoniou, Katerina; Dalla, Christina

    2017-01-01

    Preclinical psychopharmacology research needs novel behavioral indices and improved animal models for both sexes. The forced swim test (FST) is the most popular test for screening antidepressant potential. Sex differences in FST behaviors, such as immobility and swimming, are not consistent among laboratories. Reliable indices, sensitive to sex differences, are required. We identified a robust sex difference in the frequency of headshakes during the standard two session FST, with male rats exhibiting higher number of head shakes than females. Furthermore, we explored whether strain, ageing, sex- and stress-hormone levels influence this sex difference. Experiments in middle-aged and senescent Wistar rats, as well as in gonadectomized and adrenalectomized with corticosterone replacement young adult males and females, revealed that sex differences in headshakes during FST are not influenced by age or corticosterone, but are abolished following castration of male rats. Interestingly, headshake frequency correlated positively with testosterone, but not corticosterone levels. Finally, testing of Flinders Sensitive Line (FSL) and Sprague-Dawley (SD) rats in a single 5min FST session revealed that headshake frequency is sensitive to antidepressant treatment with female rats exhibiting opposite responses to treatment than male FSL rats. Mirtazapine, a 5-HT2 antagonist, enhanced headshakes in females and decreased them in male FSL rats. Based on current data and the available literature, sex differences in headshake frequency should be linked to analogous sex differences in serotonin receptors. Headshake frequency during the FST is an additional valuable behavioral index, sensitive to sex differences, gonadal hormones and antidepressants modulating serotonin receptors.

  17. Condomless Sex Among Homeless Youth: The Role of Multidimensional Social Norms and Gender.

    PubMed

    Barman-Adhikari, Anamika; Hsu, Hsun-Ta; Begun, Stephanie; Portillo, Andrea Perez; Rice, Eric

    2017-03-01

    Most studies of condomless sex among homeless youth have focused on peer norms, while excluding other potentially pertinent influences. This study explored how different types of relationships contributed to norms about condomless sex and whether such norms were associated with engagement in condomless sex among homeless youth. Additionally, because recent work has noted gender differences in social networks of male and female homeless youth, gender differences in social network norms of condomless sex were also assessed. Egocentric network data were collected from homeless youth accessing services at two drop-in centers in Los Angeles, CA (N = 976). Multivariate analyses (non-stratified and stratified by gender) assessed associations between descriptive, injunctive, and communicative norms and participants' engagement in condomless sex. Multivariate analyses indicated that perception of peer condom use and communication with sexual partners were significantly associated with not engaging in condomless sex. These relationships, however, varied by gender. Implications for interventions are discussed.

  18. Group Sparse Additive Models

    PubMed Central

    Yin, Junming; Chen, Xi; Xing, Eric P.

    2016-01-01

    We consider the problem of sparse variable selection in nonparametric additive models, with the prior knowledge of the structure among the covariates to encourage those variables within a group to be selected jointly. Previous works either study the group sparsity in the parametric setting (e.g., group lasso), or address the problem in the nonparametric setting without exploiting the structural information (e.g., sparse additive models). In this paper, we present a new method, called group sparse additive models (GroupSpAM), which can handle group sparsity in additive models. We generalize the ℓ1/ℓ2 norm to Hilbert spaces as the sparsity-inducing penalty in GroupSpAM. Moreover, we derive a novel thresholding condition for identifying the functional sparsity at the group level, and propose an efficient block coordinate descent algorithm for constructing the estimate. We demonstrate by simulation that GroupSpAM substantially outperforms the competing methods in terms of support recovery and prediction accuracy in additive models, and also conduct a comparative experiment on a real breast cancer dataset.

  19. Additive Manufacturing Infrared Inspection

    NASA Technical Reports Server (NTRS)

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  20. Evolutionarily stable sex ratios and mutation load.

    PubMed

    Hough, Josh; Immler, Simone; Barrett, Spencer C H; Otto, Sarah P

    2013-07-01

    Frequency-dependent selection should drive dioecious populations toward a 1:1 sex ratio, but biased sex ratios are widespread, especially among plants with sex chromosomes. Here, we develop population genetic models to investigate the relationships between evolutionarily stable sex ratios, haploid selection, and deleterious mutation load. We confirm that when haploid selection acts only on the relative fitness of X- and Y-bearing pollen and the sex ratio is controlled by the maternal genotype, seed sex ratios evolve toward 1:1. When we also consider haploid selection acting on deleterious mutations, however, we find that biased sex ratios can be stably maintained, reflecting a balance between the advantages of purging deleterious mutations via haploid selection, and the disadvantages of haploid selection on the sex ratio. Our results provide a plausible evolutionary explanation for biased sex ratios in dioecious plants, given the extensive gene expression that occurs across plant genomes at the haploid stage.

  1. SExSeg: SExtractor segmentation

    NASA Astrophysics Data System (ADS)

    Coe, Dan

    2015-08-01

    SExSeg forces SExtractor (ascl:1010.064) to run using a pre-defined segmentation map (the definition of objects and their borders). The defined segments double as isophotal apertures. SExSeg alters the detection image based on a pre-defined segmenation map while preparing your "analysis image" by subtracting the background in a separate SExtractor run (using parameters you specify). SExtractor is then run in "double-image" mode with the altered detection image and background-subtracted analysis image.

  2. Adolescent pregnancy and sex roles.

    PubMed

    Ireson, C J

    1984-08-01

    This study seeks to link adolescent pregnancy with several aspects of sex-role traditionality and other variables that may be related to sex roles. It is hypothesized that orientation to traditional sex roles is related to the occurrence of pregnancy among sexually active teenagers. For the study sample of teenage females receiving birth control or pregnancy testing services, it is hypothesized that the pregnant teenagers will be more likely than other teenagers to be oriented toward traditional sex roles. The sample consisted of 161 young women, ranging in age from 13-18, with an average age of 16.5 years. Data were collected at selected health related agencies in a city in the Pacific Northwest by staff members who were blind to the hypotheses of the study. The respondents usually completed a brief questionnaire while they waited for a desired service. Of the total sample, 43 were pregnant; 34 had positive pregnancy tests and 9 others already knew they were pregnant when they filled out the questionnaire. 82 obtained birth control information or services and 36 experienced negative pregnancy tests. These groups are referred to as the pregnant group, the birth control group, and the negative pregnancy test group. Sex role values were determined by asking the respondent to indicate degree of agreement or disagreement with a series of opinion statements. The results provide some support for the main hypothesis. Pregnant teenagers were more likely than others to be oriented toward traditional sex roles. Pregnant teenagers, when compared with the birth control seeking group, showed more traditional sex-typing of activities, lower educational expectations and occupational aspirations, lower grades, and were more likely to have dropped out of school. There was only 1 significant difference between the pregnant adolescents and those in the negative pregnant test group. The pregnant teens had lower educational expectations. When all the independent and control variables

  3. Monozygotic twins discordant for sex.

    PubMed Central

    Schmidt, R; Sobel, E H; Nitowsky, H M; Dar, H; Allen, F H

    1976-01-01

    A pair of monozygotic, adolescent twins is discordant for sex. The phenotypic female twin has chromosome constitution of 46, XY/45, X. She displays many signs of Turner's syndrome, including typical facies, webbed neck, malformed left kidney, high plasma gonadotropins, and streak ovaries. However, her height is 154 cm which exceeds the height usually reported in Turner's syndrome. The male twin has a karyotype of 46, XY and normal sexual development. Only two other reports of pairs of monozygotic twins of opposite sex have been published. Images PMID:944787

  4. [Unclassified sex cord testis tumor].

    PubMed

    Grenha, Vânia; Serra, Paula; Coelho, Hugo; Retroz, Edson; Temido, Paulo; Mota, Alfredo

    2014-01-01

    Unclassified sex cord testis tumor is an extremely rare tumor, especially in the adult. It is characterized histologically for a nonspecific combination of testis stromal and epithelial elements, with varying degree of differentiation. Treatment usually consists of radical orchiectomy followed by clinical and imaging surveillance. The available literature about this pathology relies almost exclusively on clinical cases. It's our aim to describe the case of a 37 years old man with an unclassified sex cord testis tumor, the first case described in Portugal, and to review the literature about this issue.

  5. Sex differences in adipose tissue

    PubMed Central

    Fuente-Martín, Esther; Argente-Arizón, Pilar; Ros, Purificación; Argente, Jesús; Chowen, Julie A

    2013-01-01

    Obesity and its associated secondary complications are active areas of investigation in search of effective treatments. As a result of this intensified research numerous differences between males and females at all levels of metabolic control have come to the forefront. These differences include not only the amount and distribution of adipose tissue, but also differences in its metabolic capacity and functions between the sexes. Here, we review some of the recent advances in our understanding of these dimorphisms and emphasize the fact that these differences between males and females must be taken into consideration in hopes of obtaining successful treatments for both sexes. PMID:23991358

  6. Spontaneous Pneumomediastinum Associated with Sex

    PubMed Central

    Flatman, Sam; Morrison, Edwin; Elahi, Maqsood

    2010-01-01

    We present a case of spontaneous pneumomediastinum (SPM) associated with sex. A 22-year-old lesbian with a history of asthma, cigarette and illicit drug smoking was diagnosed with a SPM after developing chest pain and dyspnoea in the context of performing oral sex. The main finding was subcutaneous emphysema involving the neck. SPM is an important differential diagnosis for chest pain in young people. It is a benign condition and diagnosis mainly limited to chest X-ray with increased incidence in asthmatics, smokers and drug addicts. PMID:22470723

  7. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamine, containing phenylethvnvl groups and various ratios of phthalic anhydride and 4-phenylethynviphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pvrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  8. Fused Lasso Additive Model

    PubMed Central

    Petersen, Ashley; Witten, Daniela; Simon, Noah

    2016-01-01

    We consider the problem of predicting an outcome variable using p covariates that are measured on n independent observations, in a setting in which additive, flexible, and interpretable fits are desired. We propose the fused lasso additive model (FLAM), in which each additive function is estimated to be piecewise constant with a small number of adaptively-chosen knots. FLAM is the solution to a convex optimization problem, for which a simple algorithm with guaranteed convergence to a global optimum is provided. FLAM is shown to be consistent in high dimensions, and an unbiased estimator of its degrees of freedom is proposed. We evaluate the performance of FLAM in a simulation study and on two data sets. Supplemental materials are available online, and the R package flam is available on CRAN. PMID:28239246

  9. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynylphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pyrrolidi none to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  10. Elusive Sex Acts: Pleasure and Politics in Norwegian Sex Education

    ERIC Educational Resources Information Center

    Svendsen, Stine H. Bang

    2012-01-01

    While there is little political opposition towards sex education as such in Norway, recent attempts at reforming the subject reveal underlying heteronormative presumptions that seem resistant to reform. While a focus on homosexuality is included in the national curriculum at all levels of compulsory education, the sexual practices involved in…

  11. Sex Equity and Sexuality in College Level Sex Education Courses.

    ERIC Educational Resources Information Center

    Myerson, Marilyn

    1987-01-01

    This article examines two relevant features in the historical development of sexology, the body of knowledge upon which sex education is based: its depoliticization of sexuality and its attempts to ground itself as scientific. Also examined are the sexual politics of sexology, via a content analysis of several college texts. (IAH)

  12. "Let's talk about sex": ideas for sex education in schools.

    PubMed

    Mayer, Christopher

    2002-01-01

    A school health nurse describes how he developed sessions on sex education for 14-15 year olds in the classroom setting, taking students' actual questions as a starting point. He compiled an information booklet and, with a colleague, set up a website to provide further information for the students and answer individual e-mailed queries.

  13. Learning about Sex: Resource Guide for Sex Educators. Revised Edition

    ERIC Educational Resources Information Center

    Huberman, Barbara

    2011-01-01

    Whether you are someone new to the field of sex education, trying to start a library or resource center on adolescent sexual health, or an old pro, this guide should give you a basic orientation to what's available to support your work. These resources are important to advancing positive attitudes toward adolescent sexual health and the author…

  14. Numerous transitions of sex chromosomes in Diptera.

    PubMed

    Vicoso, Beatriz; Bachtrog, Doris

    2015-04-01

    Many species groups, including mammals and many insects, determine sex using heteromorphic sex chromosomes. Diptera flies, which include the model Drosophila melanogaster, generally have XY sex chromosomes and a conserved karyotype consisting of six chromosomal arms (five large rods and a small dot), but superficially similar karyotypes may conceal the true extent of sex chromosome variation. Here, we use whole-genome analysis in 37 fly species belonging to 22 different families of Diptera and uncover tremendous hidden diversity in sex chromosome karyotypes among flies. We identify over a dozen different sex chromosome configurations, and the small dot chromosome is repeatedly used as the sex chromosome, which presumably reflects the ancestral karyotype of higher Diptera. However, we identify species with undifferentiated sex chromosomes, others in which a different chromosome replaced the dot as a sex chromosome or in which up to three chromosomal elements became incorporated into the sex chromosomes, and others yet with female heterogamety (ZW sex chromosomes). Transcriptome analysis shows that dosage compensation has evolved multiple times in flies, consistently through up-regulation of the single X in males. However, X chromosomes generally show a deficiency of genes with male-biased expression, possibly reflecting sex-specific selective pressures. These species thus provide a rich resource to study sex chromosome biology in a comparative manner and show that similar selective forces have shaped the unique evolution of sex chromosomes in diverse fly taxa.

  15. Numerous Transitions of Sex Chromosomes in Diptera

    PubMed Central

    Vicoso, Beatriz; Bachtrog, Doris

    2015-01-01

    Many species groups, including mammals and many insects, determine sex using heteromorphic sex chromosomes. Diptera flies, which include the model Drosophila melanogaster, generally have XY sex chromosomes and a conserved karyotype consisting of six chromosomal arms (five large rods and a small dot), but superficially similar karyotypes may conceal the true extent of sex chromosome variation. Here, we use whole-genome analysis in 37 fly species belonging to 22 different families of Diptera and uncover tremendous hidden diversity in sex chromosome karyotypes among flies. We identify over a dozen different sex chromosome configurations, and the small dot chromosome is repeatedly used as the sex chromosome, which presumably reflects the ancestral karyotype of higher Diptera. However, we identify species with undifferentiated sex chromosomes, others in which a different chromosome replaced the dot as a sex chromosome or in which up to three chromosomal elements became incorporated into the sex chromosomes, and others yet with female heterogamety (ZW sex chromosomes). Transcriptome analysis shows that dosage compensation has evolved multiple times in flies, consistently through up-regulation of the single X in males. However, X chromosomes generally show a deficiency of genes with male-biased expression, possibly reflecting sex-specific selective pressures. These species thus provide a rich resource to study sex chromosome biology in a comparative manner and show that similar selective forces have shaped the unique evolution of sex chromosomes in diverse fly taxa. PMID:25879221

  16. Family experiences of young adult sex offender registration.

    PubMed

    Comartin, Erin B; Kernsmith, Poco D; Miles, Bart W

    2010-03-01

    Since 1994, policies have been instituted throughout the United States that require sex offenders to register their personal information with law enforcement officials (Jacob Wetterling Crimes against Children and Sexually Violent Offender Registration Program, 1994). With the passage of additional laws, this information is now available to the public via the Internet or a request to a police department. These laws have brought about consequences for both the registrants and for members of their families. A focus group was held with four mothers who have sons listed on the Michigan Sex Offender Registry. Psychological and social consequences of registration were found and policy implications are discussed.

  17. Additives in plastics.

    PubMed Central

    Deanin, R D

    1975-01-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products. PMID:1175566

  18. Additives in plastics.

    PubMed

    Deanin, R D

    1975-06-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products.

  19. Maternal Condition but Not Corticosterone Is Linked to Offspring Sex Ratio in a Passerine Bird

    PubMed Central

    Henderson, Lindsay J.; Evans, Neil P.; Heidinger, Britt J.; Adams, Aileen; Arnold, Kathryn E.

    2014-01-01

    There is evidence of offspring sex ratio adjustment in a range of species, but the potential mechanisms remain largely unknown. Elevated maternal corticosterone (CORT) is associated with factors that can favour brood sex ratio adjustment, such as reduced maternal condition, food availability and partner attractiveness. Therefore, the steroid hormone has been suggested to play a key role in sex ratio manipulation. However, despite correlative and causal evidence CORT is linked to sex ratio manipulation in some avian species, the timing of adjustment varies between studies. Consequently, whether CORT is consistently involved in sex-ratio adjustment, and how the hormone acts as a mechanism for this adjustment remains unclear. Here we measured maternal baseline CORT and body condition in free-living blue tits (Cyanistes caeruleus) over three years and related these factors to brood sex ratio and nestling quality. In addition, a non-invasive technique was employed to experimentally elevate maternal CORT during egg laying, and its effects upon sex ratio and nestling quality were measured. We found that maternal CORT was not correlated with brood sex ratio, but mothers with elevated CORT fledged lighter offspring. Also, experimental elevation of maternal CORT did not influence brood sex ratio or nestling quality. In one year, mothers in superior body condition produced male biased broods, and maternal condition was positively correlated with both nestling mass and growth rate in all years. Unlike previous studies maternal condition was not correlated with maternal CORT. This study provides evidence that maternal condition is linked to brood sex ratio manipulation in blue tits. However, maternal baseline CORT may not be the mechanistic link between the maternal condition and sex ratio adjustment. Overall, this study serves to highlight the complexity of sex ratio adjustment in birds and the difficulties associated with identifying sex biasing mechanisms. PMID:25347532

  20. Sex-biased gene expression at homomorphic sex chromosomes in emus and its implication for sex chromosome evolution.

    PubMed

    Vicoso, Beatriz; Kaiser, Vera B; Bachtrog, Doris

    2013-04-16

    Sex chromosomes originate from autosomes. The accumulation of sexually antagonistic mutations on protosex chromosomes selects for a loss of recombination and sets in motion the evolutionary processes generating heteromorphic sex chromosomes. Recombination suppression and differentiation are generally viewed as the default path of sex chromosome evolution, and the occurrence of old, homomorphic sex chromosomes, such as those of ratite birds, has remained a mystery. Here, we analyze the genome and transcriptome of emu (Dromaius novaehollandiae) and confirm that most genes on the sex chromosome are shared between the Z and W. Surprisingly, however, levels of gene expression are generally sex-biased for all sex-linked genes relative to autosomes, including those in the pseudoautosomal region, and the male-bias increases after gonad formation. This expression bias suggests that the emu sex chromosomes have become masculinized, even in the absence of ZW differentiation. Thus, birds may have taken different evolutionary solutions to minimize the deleterious effects imposed by sexually antagonistic mutations: some lineages eliminate recombination along the protosex chromosomes to physically restrict sexually antagonistic alleles to one sex, whereas ratites evolved sex-biased expression to confine the product of a sexually antagonistic allele to the sex it benefits. This difference in conflict resolution may explain the preservation of recombining, homomorphic sex chromosomes in other lineages and illustrates the importance of sexually antagonistic mutations driving the evolution of sex chromosomes.

  1. Biobased lubricant additives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fully biobased lubricants are those formulated using all biobased ingredients, i.e. biobased base oils and biobased additives. Such formulations provide the maximum environmental, safety, and economic benefits expected from a biobased product. Currently, there are a number of biobased base oils that...

  2. More Than Additional Space...

    ERIC Educational Resources Information Center

    CEFP Journal, 1973

    1973-01-01

    A much needed addition to the Jamestown Elementary School turned out to be more than an expansion of walls for more space. A new educational program, a limited budget, and a short time line were tackled on a team approach basis and were successfully resolved. (Author)

  3. Effects of sex chromosome aneuploidy on male sexual behavior.

    PubMed

    Park, J H; Burns-Cusato, M; Dominguez-Salazar, E; Riggan, A; Shetty, S; Arnold, A P; Rissman, E F

    2008-08-01

    Incidence of sex chromosome aneuploidy in men is as high as 1:500. The predominant conditions are an additional Y chromosome (47,XYY) or an additional X chromosome (47,XXY). Behavioral studies using animal models of these conditions are rare. To assess the role of sex chromosome aneuploidy on sexual behavior, we used mice with a spontaneous mutation on the Y chromosome in which the testis-determining gene Sry is deleted (referred to as Y(-)) and insertion of a Sry transgene on an autosome. Dams were aneuploid (XXY(-)) and the sires had an inserted Sry transgene (XYSry). Litters contained six male genotypes, XY, XYY(-), XXSry, XXY(-)Sry, XYSry and XYY(-)Sry. In order to eliminate possible differences in levels of testosterone, all of the subjects were castrated and received testosterone implants prior to tests for male sex behavior. Mice with an additional copy of the Y(-) chromosome (XYY(-)) had shorter latencies to intromit and achieve ejaculations than XY males. In a comparison of the four genotypes bearing the Sry transgene, males with two copies of the X chromosome (XXSry and XXY(-)Sry) had longer latencies to mount and thrust than males with only one copy of the X chromosome (XYSry and XYY(-)Sry) and decreased frequencies of mounts and intromissions as compared with XYSry males. The results implicate novel roles for sex chromosome genes in sexual behaviors.

  4. Effects of sex chromosome aneuploidy on male sexual behavior

    PubMed Central

    Park, J. H.; Burns-Cusato, M.; Dominguez-Salazar, E.; Riggan, A.; Shetty, S.; Arnold, A. P.; Rissman, E. F.

    2008-01-01

    Incidence of sex chromosome aneuploidy in men is as high as 1:500. The predominant conditions are an additional Y chromosome (47,XYY) or an additional X chromosome (47,XXY). Behavioral studies using animal models of these conditions are rare. To assess the role of sex chromosome aneuploidy on sexual behavior, we used mice with a spontaneous mutation on the Y chromosome in which the testis-determining gene Sry is deleted (referred to as Y−) and insertion of a Sry transgene on an autosome. Dams were aneuploid (XXY−) and the sires had an inserted Sry transgene (XYSry). Litters contained six male genotypes, XY, XYY−, XXSry, XXY−Sry, XYSry and XYY−Sry. In order to eliminate possible differences in levels of testosterone, all of the subjects were castrated and received testosterone implants prior to tests for male sex behavior. Mice with an additional copy of the Y− chromosome (XYY−) had shorter latencies to intromit and achieve ejaculations than XY males. In a comparison of the four genotypes bearing the Sry transgene, males with two copies of the X chromosome (XXSry and XXY−Sry) had longer latencies to mount and thrust than males with only one copy of the X chromosome (XYSry and XYY−Sry) and decreased frequencies of mounts and intromissions as compared with XYSry males. The results implicate novel roles for sex chromosome genes in sexual behaviors. PMID:18363850

  5. Application and commercialization of flow cytometrically sex-sorted semen.

    PubMed

    Rath, D; Johnson, L A

    2008-07-01

    The current technology to sort X and Y chromosome bearing sperm population requires individual identification and selection of spermatozoa in a modified high-speed flow cytometer. For farm animal species, the technology is capable of producing sexed sperm at greater than 90% purity. However, only in the bovine, the technology has reached a developmental level that allows its commercial application. Meanwhile, the demand for female calves has grown rapidly, which encourages the demand for sex-sorted semen from high genetic value bulls. The success of the technology will depend mainly on the fertilizing capacity of the sorted spermatozoa, as this is the most affecting and economically relevant factor. To date, fertility is still variable and is quite dependent on post-sort processing. New processing techniques are under investigation and will likely be able to improve the fertility rates after AI with sex-sorted semen. It is of great importance to select the right bulls and to test the sorted samples on a routine basis. In addition to the demand for sex-sorted semen by the cattle industry, there is also a significant demand expressed by pig farmers. However, it is still unknown if the use of sex-sorted semen through commercial pig AI will be economically feasible. For the pig, the combination of in vitro fertilization with sexed semen and non-surgical embryo transfer is an alternative that merits further scientific attention. Recent developments in ovine AI and ET will make it very likely that commercial sheep industry will adopt the sexing technology in their breeding concepts.

  6. Sex and the Circuitry: Progress Toward a Systems-Level Understanding of Vertebrate Sex Determination

    PubMed Central

    Munger, Steven C; Capel, Blanche

    2017-01-01

    In vertebrates, the gonad arises as a bipotential primordium that can differentiate as a testis or ovary. Cells are initially primed to adopt either fate by balanced antagonistic signaling pathways and transcription networks. Sexual fate is determined by activating the testis or ovarian pathway and repressing the alternative pathway. A complex, dynamic transcription network underlies this process, as approximately half the genome is being transcribed during this period, and many genes are expressed in a sexually dimorphic manner. This network is highly plastic, however multiple lines of evidence suggest that many elements of the pathway converge on the stabilization or disruption of Sox9 expression. The single gene mutational approach has led to the identification of ~30 additional genes involved in vertebrate sex determination. However,>50% of human disorders of sexual development (DSDs) are not explained by any of these genes, suggesting many critical elements of the system await discovery. Emerging technologies and genetic resources enable the investigation of the sex determination network on a global scale in the context of a variable genetic background or environmental influences. Using these new tools we can investigate how cells establish a bipotential state that is poised to adopt either sexual fate, and how they integrate multiple signaling and transcriptional inputs to drive a cell fate decision. Elucidating the genetic architecture underlying sex determination in model systems can lead to the identification of conserved modules correlated with phenotypic outcomes, and critical pressure points in the network that predict genes involved in DSDs in humans. PMID:22605638

  7. Do scientific theories affect men's evaluations of sex crimes?

    PubMed

    Dar-Nimrod, Ilan; Heine, Steven J; Cheung, Benjamin Y; Schaller, Mark

    2011-01-01

    Evolutionary psychology accounts of gender differences in sexual behaviors in general and men's sexual aggression, in particular, has been criticized for legitimizing males' sexual misconduct. To empirically assess such critiques, two studies examined how men's judgments of male sex crimes (solicitation of sex from a prostitute; rape) are influenced by exposure to (a) evolutionary psychological theories and (b) social-constructivist theories. Across two studies, a consistent pattern emerged compared with a control condition (a) exposure to evolutionary psychology theories had no observable impact on male judgments of men's criminal sexual behavior, whereas (b) exposure to social-constructivist theories did affect judgments, leading men to evaluate sex crimes more harshly. Additional results (from Study 2) indicate that this effect is mediated by perceptions of male control over sexual urges. These results have implications for journalists, educators, and scientists. Aggr. Behav. 37:440-449, 2011. © 2011 Wiley-Liss, Inc.

  8. Inequalities in health: the value of sex-related indicators.

    PubMed Central

    Benigni, Romualdo

    2003-01-01

    My laboratory has previously shown that the sex differences in tumor incidence in Europe can be related to the female social condition and that the pattern of this relationship varies according to the different historical contexts. In this article, I have extended the study worldwide to all cancer registries, and I present the sex differences in life expectancy at birth. A close link between the health of the populations and socioeconomic and cultural factors was confirmed. The sex-related indicators had a distribution independent from the parent variables cancer incidence and life expectancy; thus, they carry complementary information and provide an additional, sensitive probe for monitoring the health of the populations. PMID:12676593

  9. The Medical Response to Sex Trafficking of Minors in Wisconsin.

    PubMed

    Rabbitt, Angela

    2015-04-01

    Medical professionals are in a unique position to identify and assist pediatric victims of sex trafficking, who experience a high prevalence of physical, mental, and sexual health problems. However, providers report a need for education and guidelines for medical care of this population. A literature review was conducted on the nature and scope of pediatric sex trafficking in Wisconsin, the medical and mental health needs of victims, and existing guidelines for medical management. Few existing medical guidelines for the care of trafficking victims are specific to pediatrics or include specific recommendations for the forensic medical evaluation. Because of legislation and resources specific to Wisconsin, national guidelines may not apply locally. Based on the literature review, as well as input from community partners and medical professionals who frequently provide services to victims, guidelines for the medical care of pediatric sex trafficking victims in Wisconsin were developed. Additional community barriers that may prevent an effective medical response also are discussed.

  10. Overexpression of Anti-Müllerian Hormone Disrupts Gonadal Sex Differentiation, Blocks Sex Hormone Synthesis, and Supports Cell Autonomous Sex Development in the Chicken.

    PubMed

    Lambeth, Luke S; Morris, Kirsten; Ayers, Katie L; Wise, Terry G; O'Neil, Terri; Wilson, Susanne; Cao, Yu; Sinclair, Andrew H; Cutting, Andrew D; Doran, Timothy J; Smith, Craig A

    2016-03-01

    The primary role of Anti-Müllerian hormone (AMH) during mammalian development is the regression of Müllerian ducts in males. This highly conserved function is retained in birds and is supported by the high levels of AMH expression in developing testes. Mammalian AMH expression is regulated by a combination of transcription factors, the most important being Sry-type high-mobility-group box transcription factor-9 (SOX9). In the chicken embryo, however, AMH mRNA expression precedes that of SOX9, leading to the view that AMH may play a more central role in avian testicular development. To define its role in chicken gonadal development, AMH was overexpressed using the RCASBP viral vector. AMH caused the gonads of both sexes to develop as small and undeveloped structures at both embryonic and adult stages. Molecular analysis revealed that although female gonads developed testis-like cords, gonads lacked Sertoli cells and were incapable of steroidogenesis. A similar gonadal phenotype was also observed in males, with a complete loss of both Sertoli cells, disrupted SOX9 expression and gonadal steroidogenesis. At sexual maturity both sexes showed a female external phenotype but retained sexually dimorphic body weights that matched their genetic sexes. These data suggest that AMH does not operate as an early testis activator in the chicken but can affect downstream events, such as sex steroid hormone production. In addition, this study provides a unique opportunity to assess chicken sexual development in an environment of sex hormone deficiency, demonstrating the importance of both hormonal signaling and direct cell autonomous factors for somatic sex identity in birds.

  11. Safe Sex Tips for Seniors

    MedlinePlus

    ... age-related health problems. Use a condom and lubricant Use a condom and lubricant every time you have sex until you know ... are in a sexually exclusive relationship. Water-based lubricants such as K-Y Jelly are important because ...

  12. Measuring Equality Between the Sexes

    ERIC Educational Resources Information Center

    Dixon, Ruth B.

    1976-01-01

    Notes that women have made great gains in learning about and using effective birth control. The widest gap between the sexes appears in the exercise of power in the highest levels of the political and occupational structure, both of which remain almost totally male dominated. (Author/AM)

  13. Current Research on Sex Roles.

    ERIC Educational Resources Information Center

    Sells, Lucy W., Comp.

    Focusing on women, this annotated bibliography reviews recent research-oriented literature that investigates sex roles. The main concern is the role and place of women in present-day United States society. The literature areas which the bibliography covers are bibliographies and sources, action organizations, media, women's movement, affirmative…

  14. Sex determination in flowering plants.

    PubMed Central

    Dellaporta, S L; Calderon-Urrea, A

    1993-01-01

    In many ways, plants offer unique systems through which to study sex determination. Because the production of unisexual flowers has evolved independently in many plant species, different and novel mechanisms may be operational. Hence, there is probably not one unifying mechanism that explains sex determination in plants. Advances in our understanding of sex determination will come from the analysis of the genetics, molecular biology, and biochemistry of genes controlling sexual determination in plants. Several excellent model systems for bisexual floral development (Arabidopsis and Antirrhinum), monoecy (maize), and dioecy (Silene, asparagus, and mercury) are available for such analyses. The important questions that remain concern the mechanism of action of sex determination genes and their interrelationship, if any, with homeotic genes that determine the sexual identity of floral organ primordia. At the physiological level, the connection between hormone signaling and sexuality is not well understood, although significant correlations have been discovered. Finally, once the genes that regulate these processes are identified, cloned, and studied, new strategies for the manipulation of sexuality in plants should be forthcoming. PMID:8281039

  15. Helping parents with sex education.

    PubMed

    Wakley, Gill

    2011-01-01

    Health visitors, school nurses and other community nurses are sometimes asked for advice by parents and carers on the emerging sexuality of their children. Parents often lack knowledge about sexual development and are confused about whether to talk to their children about sex. They may have been brought up in a family where sex was not mentioned. They are worried that they do not have the skills or the knowledge to help their children. They do not know whether to leave it all to the school or not allow their children to have any information. All the evidence shows that children who have had their questions answered and who know about sex and relationships start sexual activity later, use contraception more reliably and are less likely to cause or have an unwanted pregnancy. Sex education should be part of the ordinary information and moral guidance that parents normally give and should start as early as possible. The type of advice to give to parents and carers is split into age ranges that they might find helpful. Examples of language and the level of information required are given. A list of resources for further guidance is included.

  16. Religious Freedom vs. Sex Equality

    ERIC Educational Resources Information Center

    Song, Sarah

    2006-01-01

    This essay examines Susan Moller Okin's writing on conflicts between religious freedom and sex equality, and her criticism of "political liberal" approaches to these conflicts, which I take to be a part of her lifelong critique of the public-private distinction. I argue that, while Okin ultimately accepted a version of the distinction, she was…

  17. Children as Sex Offenders, Why?

    ERIC Educational Resources Information Center

    Deranek, Traci; Gilman, David A.

    This study investigates juvenile sex offenders and the predetermining factors that are present in their lives, prior to their first offenses. This study will give an overview of theories, children's sexual behaviors ranging from normal to disturbed, and family dynamics of juvenile offenders. The treatment files of boys and young men, currently in…

  18. Sex Education in Multicultural Norway

    ERIC Educational Resources Information Center

    Bartz, Tiffany

    2007-01-01

    Scandinavia has long been admired by American liberals and sex education advocates who cite comparable rates of adolescent sexuality, yet lower rates of teenage pregnancy, sexually transmitted diseases and abortion in Scandinavia. The United States has, however, two variables with which Scandinavia in general, and Norway in particular, has not…

  19. Sex Attraction in Pear Psylla

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae), a major economic pest of pears, have been shown to use a female-produced sex attractant pheromone. We compared the chemical profiles obtained from solvent extracts of diapausing and post-diapause winterform males and females, with g...

  20. Sex Differences in Drug Disposition

    PubMed Central

    Soldin, Offie P.; Chung, Sarah H.; Mattison, Donald R.

    2011-01-01

    Physiological, hormonal, and genetic differences between males and females affect the prevalence, incidence, and severity of diseases and responses to therapy. Understanding these differences is important for designing safe and effective treatments. This paper summarizes sex differences that impact drug disposition and includes a general comparison of clinical pharmacology as it applies to men and women. PMID:21403873

  1. Sex Discrimination and Intercollegiate Athletics

    ERIC Educational Resources Information Center

    Iowa Law Review, 1975

    1975-01-01

    The nature and pervasiveness of sex-based inequalities within collegiate athletics are reviewed with regard to constitutional mandates as interpreted by Title IX and the proposed Equal Rights Amendment. Special attention is given to the once discredited "separate but equal" doctrine. (LBH)

  2. Personality, Sex, and Work Values.

    ERIC Educational Resources Information Center

    Hales, Loyde; Hartman, Timothy

    1978-01-01

    The Vocational Preference Inventory (VPA) and the Ohio Work Values Inventory (OWVI) were administered to 115 undergraduates. A two-factor MANOVA was performed with personality types (VPI) and sex as independent variables and work values (OWVI) as dependent variables. The F-ratios for main effects were significant. (Author/SJL)

  3. Sex Education, Concerns and Attitudes.

    ERIC Educational Resources Information Center

    Brown, Robert M.

    The general concern over an Acquired Immune Deficiency Syndrome (AIDS) epidemic and the government's need to educate and protect its citizens from this disease seem to have softened resistance to sex education in schools. The only viable defense against AIDS seems to be education, since there are no vaccines or effective treatments. Still, some…

  4. Facets: Sex and Language Features.

    ERIC Educational Resources Information Center

    English Journal, 1983

    1983-01-01

    Presents (1) suggestions of a sex-related frequency variation in vocabulary, pronunciation, and grammar; (2) evidence of increased sensitivity to sexist language in the manuscripts submitted to the National Council of Teachers of English; (3) a proposed substitution of "Dear Reader" for "Gentlemen" in business correspondence; and (4) a description…

  5. Sex Education. Grades K-12.

    ERIC Educational Resources Information Center

    Instructional Objectives Exchange, Los Angeles, CA.

    This collection of fifty objectives, related sample items, and directions for administering and scoring, is divided into three sections. The first, growth and development, deals with basic factual information relating to sex education; both animal and human biology are included. The second section, social and emotional growth, deals with the…

  6. Sex Role and Dating Orientation.

    ERIC Educational Resources Information Center

    McCabe, M. P.; Collins, J. K.

    1979-01-01

    Male and female subjects from three age groups completed questionnaires on sex roles and dating orientations. Males approached dating from both a psychoaffectional and psychobiological orientation, while females approached it from a psychoaffectional orientation. Significant differences were found in dating attitudes between male and female…

  7. Sex rights for the disabled?

    PubMed

    Appel, Jacob M

    2010-03-01

    The public discourse surrounding sex and severe disability over the past 40 years has largely focused on protecting vulnerable populations from abuse. However, health professionals and activists are increasingly recognising the inherent sexuality of disabled persons and attempting to find ways to accommodate their intimacy needs. This essay explores several ethical issues arising from such efforts.

  8. Sex, Lies and Video Games

    ERIC Educational Resources Information Center

    Kearney, Paul; Pivec, Maja

    2007-01-01

    Sex and violence in video games is a social issue that confronts us all, especially as many commercial games are now being introduced for game-based learning in schools, and as such this paper polls teenage players about the rules their parents and teachers may or may not have, and surveys the gaming community, ie, game developers to parents, to…

  9. Sex and Sexuality and HIV

    MedlinePlus

    ... it visually for any holes. If the dental dam has cornstarch on it, rinse that off with water (starch in the vagina can lead to an infection). Cover the woman's genital area with the dental dam. For oral-anal sex, cover the opening of ...

  10. Sex Bias in Counseling Materials

    ERIC Educational Resources Information Center

    Harway, Michele

    1977-01-01

    This article reviews findings of bias in counseling materials and presents results of three original studies. Indications are that textbooks used by practitioners present the sexes in stereotypical fashion, and a greater proportion of college catalog context is devoted to men than to women. (Author)

  11. Guess Who's Pregnant? Sex Education.

    ERIC Educational Resources Information Center

    Thoms, George H.; And Others

    Statistics on teenage pregnancy, the rate of venereal disease, and media representations of sexual mores are offered as rationale for the inclusion of sex education in the elementary-secondary school curriculum. The program of the George Mason Junior-Senior High School (Falls Church, Virginia) is described and used as a model for the discussion of…

  12. Creativity and Psychopathology: Sex Matters

    ERIC Educational Resources Information Center

    Martín-Brufau, Ramón; Corbalán, Javier

    2016-01-01

    The association between creativity and psychopathology has, for decades, been a focus of heated debate fuelled by contradictory findings. Nevertheless, the findings suggest complex associations between creativity and psychopathology. Other studies have investigated the association between creativity and sex, with inconsistent results. The aim of…

  13. Transactional sex among men and women in the south at high risk for HIV and other STIs.

    PubMed

    Bobashev, Georgiy V; Zule, William A; Osilla, Karen C; Kline, Tracy L; Wechsberg, Wendee M

    2009-07-01

    Transactional sex refers to selling sex (exchanging sex for money, drugs, food, shelter, or other items) or purchasing sex (exchanging money, drugs, food, shelter, or other items for sex). These activities have been associated with a higher risk for HIV and other sexually transmitted infections in a variety of populations and settings. This paper examines correlates of purchasing and selling sex in a large sample of drug users, men who have sex with men, and sex partners of these groups. Using respondent-driven sampling, participants were recruited between 2005 and 2008 in two urban and two rural counties in North Carolina. We used multiple logistic regressions to examine separate models for selling and purchasing sex in men and women. In addition, we estimated direct and indirect associations among independent variables in the logistic regression models and transactional sex using structural equation models. The analysis shows that factors associated with women selling and buying sex include being homeless, use of stimulants, bisexual behavior, and neighborhood disorder. There was also a significant difference by race. For men, the factors associated with selling and buying sex include being homeless, bisexual behavior, and not being in a relationship. Although neighborhood violence and disorder show significance in bivariate associations with the outcome, these associations disappear in the structural equation models.

  14. Vinyl capped addition polyimides

    NASA Technical Reports Server (NTRS)

    Vannucci, Raymond D. (Inventor); Malarik, Diane C. (Inventor); Delvigs, Peter (Inventor)

    1991-01-01

    Polyimide resins (PMR) are generally useful where high strength and temperature capabilities are required (at temperatures up to about 700 F). Polyimide resins are particularly useful in applications such as jet engine compressor components, for example, blades, vanes, air seals, air splitters, and engine casing parts. Aromatic vinyl capped addition polyimides are obtained by reacting a diamine, an ester of tetracarboxylic acid, and an aromatic vinyl compound. Low void materials with improved oxidative stability when exposed to 700 F air may be fabricated as fiber reinforced high molecular weight capped polyimide composites. The aromatic vinyl capped polyimides are provided with a more aromatic nature and are more thermally stable than highly aliphatic, norbornenyl-type end-capped polyimides employed in PMR resins. The substitution of aromatic vinyl end-caps for norbornenyl end-caps in addition polyimides results in polymers with improved oxidative stability.

  15. Effects of sex chromosome dosage on corpus callosum morphology in supernumerary sex chromosome aneuploidies

    PubMed Central

    2014-01-01

    Background Supernumerary sex chromosome aneuploidies (sSCA) are characterized by the presence of one or more additional sex chromosomes in an individual’s karyotype; they affect around 1 in 400 individuals. Although there is high variability, each sSCA subtype has a characteristic set of cognitive and physical phenotypes. Here, we investigated the differences in the morphometry of the human corpus callosum (CC) between sex-matched controls 46,XY (N =99), 46,XX (N =93), and six unique sSCA karyotypes: 47,XYY (N =29), 47,XXY (N =58), 48,XXYY (N =20), 47,XXX (N =30), 48,XXXY (N =5), and 49,XXXXY (N =6). Methods We investigated CC morphometry using local and global area, local curvature of the CC boundary, and between-landmark distance analysis (BLDA). We hypothesized that CC morphometry would vary differentially along a proposed spectrum of Y:X chromosome ratio with supernumerary Y karyotypes having the largest CC areas and supernumerary X karyotypes having significantly smaller CC areas. To investigate this, we defined an sSCA spectrum based on a descending Y:X karyotype ratio: 47,XYY, 46,XY, 48,XXYY, 47,XXY, 48,XXXY, 49,XXXXY, 46,XX, 47,XXX. We similarly explored the effects of both X and Y chromosome numbers within sex. Results of shape-based metrics were analyzed using permutation tests consisting of 5,000 iterations. Results Several subregional areas, local curvature, and BLDs differed between groups. Moderate associations were found between area and curvature in relation to the spectrum and X and Y chromosome counts. BLD was strongly associated with X chromosome count in both male and female groups. Conclusions Our results suggest that X- and Y-linked genes have differential effects on CC morphometry. To our knowledge, this is the first study to compare CC morphometry across these extremely rare groups. PMID:25780557

  16. Electrophilic addition of astatine

    SciTech Connect

    Norseev, Yu.V.; Vasaros, L.; Nhan, D.D.; Huan, N.K.

    1988-03-01

    It has been shown for the first time that astatine is capable of undergoing addition reactions to unsaturated hydrocarbons. A new compound of astatine, viz., ethylene astatohydrin, has been obtained, and its retention numbers of squalane, Apiezon, and tricresyl phosphate have been found. The influence of various factors on the formation of ethylene astatohydrin has been studied. It has been concluded on the basis of the results obtained that the univalent cations of astatine in an acidic medium is protonated hypoastatous acid.

  17. Sex between people with "mental retardation": an ethical evaluation.

    PubMed

    Spiecker, Ben; Steutel, Jan

    2002-06-01

    Is sex between people with "mental retardation" [1] morally permissible and, if at all, under what conditions? This paper tries to answer this question, but only with regard to sex between biologically mature individuals with mild or moderate mental retardation. First, the concepts of "sexual activity" and mental retardation" are analysed briefly, which is challenging given the widely divergent and sometimes rather awkward definitions of these concepts. On the basis of this analysis, it is argued that the liberal principle of mutual consent, if taken as a necessary condition of permissible sex, has unacceptable consequences for people with mental retardation. Many forms of sex between them would be morally impermissible, given the fact that their limited powers of practical reasoning will often make valid consent well-nigh impossible. As an alternative to the liberal principle of permissible sex, conditions are specified that include the additional consent of caretakers. If people with mental retardation do not have the capacities of practical deliberation required for valid consent, care providers with mature reasoning powers should act as their substitutes. Finally, some important implications for the moral education of future care professionals are spelled out.

  18. Sex-specific mating pheromones in the nematode Panagrellus redivivus.

    PubMed

    Choe, Andrea; Chuman, Tatsuji; von Reuss, Stephan H; Dossey, Aaron T; Yim, Joshua J; Ajredini, Ramadan; Kolawa, Adam A; Kaplan, Fatma; Alborn, Hans T; Teal, Peter E A; Schroeder, Frank C; Sternberg, Paul W; Edison, Arthur S

    2012-12-18

    Nematodes use an extensive chemical language based on glycosides of the dideoxysugar ascarylose for developmental regulation (dauer formation), male sex attraction, aggregation, and dispersal. However, no examples of a female- or hermaphrodite-specific sex attractant have been identified to date. In this study, we investigated the pheromone system of the gonochoristic sour paste nematode Panagrellus redivivus, which produces sex-specific attractants of the opposite sex. Activity-guided fractionation of the P. redivivus exometabolome revealed that males are strongly attracted to ascr#1 (also known as daumone), an ascaroside previously identified from Caenorhabditis elegans hermaphrodites. Female P. redivivus are repelled by high concentrations of ascr#1 but are specifically attracted to a previously unknown ascaroside that we named dhas#18, a dihydroxy derivative of the known ascr#18 and an ascaroside that features extensive functionalization of the lipid-derived side chain. Targeted profiling of the P. redivivus exometabolome revealed several additional ascarosides that did not induce strong chemotaxis. We show that P. redivivus females, but not males, produce the male-attracting ascr#1, whereas males, but not females, produce the female-attracting dhas#18. These results show that ascaroside biosynthesis in P. redivivus is highly sex-specific. Furthermore, the extensive side chain functionalization in dhas#18, which is reminiscent of polyketide-derived natural products, indicates unanticipated biosynthetic capabilities in nematodes.

  19. Sex-specific mating pheromones in the nematode Panagrellus redivivus

    PubMed Central

    Choe, Andrea; Chuman, Tatsuji; von Reuss, Stephan H.; Dossey, Aaron T.; Yim, Joshua J.; Ajredini, Ramadan; Kolawa, Adam A.; Kaplan, Fatma; Alborn, Hans T.; Teal, Peter E. A.; Schroeder, Frank C.; Sternberg, Paul W.; Edison, Arthur S.

    2012-01-01

    Nematodes use an extensive chemical language based on glycosides of the dideoxysugar ascarylose for developmental regulation (dauer formation), male sex attraction, aggregation, and dispersal. However, no examples of a female- or hermaphrodite-specific sex attractant have been identified to date. In this study, we investigated the pheromone system of the gonochoristic sour paste nematode Panagrellus redivivus, which produces sex-specific attractants of the opposite sex. Activity-guided fractionation of the P. redivivus exometabolome revealed that males are strongly attracted to ascr#1 (also known as daumone), an ascaroside previously identified from Caenorhabditis elegans hermaphrodites. Female P. redivivus are repelled by high concentrations of ascr#1 but are specifically attracted to a previously unknown ascaroside that we named dhas#18, a dihydroxy derivative of the known ascr#18 and an ascaroside that features extensive functionalization of the lipid-derived side chain. Targeted profiling of the P. redivivus exometabolome revealed several additional ascarosides that did not induce strong chemotaxis. We show that P. redivivus females, but not males, produce the male-attracting ascr#1, whereas males, but not females, produce the female-attracting dhas#18. These results show that ascaroside biosynthesis in P. redivivus is highly sex-specific. Furthermore, the extensive side chain functionalization in dhas#18, which is reminiscent of polyketide-derived natural products, indicates unanticipated biosynthetic capabilities in nematodes. PMID:23213209

  20. Erecting Sex: Hermaphrodites and the Medieval Science of Surgery.

    PubMed

    DeVun, Leah

    2015-01-01

    This essay focuses on "hermaphrodites" and the emerging profession of surgery in thirteenth- and fourteenth-century Europe. During this period, surgeons made novel claims about their authority to regulate sexual difference by surgically ''correcting" errant sexual anatomies. Their theories about sex, I argue, drew upon both ancient roots and contemporary conflicts to conceptualize sexual difference in ways that influenced Western Europe for centuries thereafter. I argue that a close examination of medieval surgical texts complicates orthodox narratives in the broader history of sex and sexuality: medieval theorists approached sex in sophisticated and varied manners that belie any simple opposition of modern and premodern paradigms. In addition, because surgical treatments of hermaphrodites in the Middle Ages prefigure in many ways the treatment of atypical sex (a condition now called, controversially, intersex or disorders/differences of sex development) in the modern world, I suggest that the writings of medieval surgeons have the potential to provide new perspectives on our current debates about surgery and sexual difference.

  1. Predicting the evolution of sex on complex fitness landscapes.

    PubMed

    Misevic, Dusan; Kouyos, Roger D; Bonhoeffer, Sebastian

    2009-09-01

    Most population genetic theories on the evolution of sex or recombination are based on fairly restrictive assumptions about the nature of the underlying fitness landscapes. Here we use computer simulations to study the evolution of sex on fitness landscapes with different degrees of complexity and epistasis. We evaluate predictors of the evolution of sex, which are derived from the conditions established in the population genetic literature for the evolution of sex on simpler fitness landscapes. These predictors are based on quantities such as the variance of Hamming distance, mean fitness, additive genetic variance, and epistasis. We show that for complex fitness landscapes all the predictors generally perform poorly. Interestingly, while the simplest predictor, Delta Var(HD), also suffers from a lack of accuracy, it turns out to be the most robust across different types of fitness landscapes. Delta Var(HD) is based on the change in Hamming distance variance induced by recombination and thus does not require individual fitness measurements. The presence of loci that are not under selection can, however, severely diminish predictor accuracy. Our study thus highlights the difficulty of establishing reliable criteria for the evolution of sex on complex fitness landscapes and illustrates the challenge for both theoretical and experimental research on the origin and maintenance of sexual reproduction.

  2. Is homophobia associated with an implicit same-sex attraction?

    PubMed

    Macinnis, Cara C; Hodson, Gordon

    2013-01-01

    Some theorists propose that homophobia stems from underlying same-sex attraction. A few studies have tested this hypothesis, yet without a clear measure of implicit sexual attraction, producing mixed results. For the first time, we test this attraction-based account of homophobia among both men and women using an implicit measure of sexual attraction. No evidence of an attraction-based account of homophobia emerged. Instead, implicit same-sex attraction was related to positive evaluations of gay men and lesbians among female participants. Even in targeted analyses examining the relation between implicit same-sex attraction and homosexual evaluations among only those theoretically most likely to demonstrate an attraction-based homophobic effect, implicit same-sex attraction was not associated with evaluations of homosexuals or was associated with more positive evaluations of homosexuals. In addition, explicit same-sex attraction was related to positive evaluations of gay men and lesbians for male participants. These results are more in keeping with the attitude-similarity effect (i.e., people like, rather than dislike, similar others).

  3. Sex offenders and sex crime recidivism: investigating the role of sentence length and time served.

    PubMed

    Budd, Kristen; Desmond, Scott A

    2014-12-01

    The relationship between criminal justice sanctions and sex crime recidivism remains largely unexplored. Therefore, using a sample of 8,461 previously incarcerated male sex offenders from 13 states in the United States, we focus on the sentence meted out for the sex crime conviction and the amount of time sex offenders served as a result of their conviction. Sex offenders were grouped into four categories: rapists, sexual assaulters, child molesters, and all sex offenders combined. Recidivism was operationalized as rearrest and reconviction. Findings suggest how recidivism is operationalized matters. When recidivism is measured as rearrest for another sex offense, sentence length and time served are unrelated to sex crime recidivism. On the other hand, when recidivism is operationalized as reconviction for another sex offense, sentence length is positively related to recidivism for rapists, sexual assaulters, child molesters, and all sex offenders combined, while time served is negatively related to recidivism for child molesters and all sex offenders combined.

  4. How Do Social Norms Impact HIV Sexual Risk Behavior in HIV Positive Men Who Have Sex with Men: Multiple Mediator Effects

    PubMed Central

    Miner, Michael H.; Peterson, John L.; Welles, Seth L.; Jacoby, Scott M.; Rosser, B.R. Simon

    2012-01-01

    This study examines mediation of the association between social norms and unsafe sexual behavior. Self-report data were collected from 675 HIV-infected men enrolled in a study exploring interventions for HIV risk behavior. Unsafe sex included any unprotected anal sex with HIV-negative or HIV status unknown partners in the last three months. Norms for condom use indirectly influenced unsafe sex through condom self-efficacy and/or safer sex intentions. Additionally, sexual behavior discontrol influenced unsafe sex regardless of other individual or social factors. Our results suggest that interventions consider the combined effects of condom self-efficacy, safer sex intentions, and sexual behavior control. PMID:19687113

  5. Functional Generalized Additive Models.

    PubMed

    McLean, Mathew W; Hooker, Giles; Staicu, Ana-Maria; Scheipl, Fabian; Ruppert, David

    2014-01-01

    We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F{X(t), t} where F(·,·) is an unknown regression function and X(t) is a functional covariate. Rather than having an additive model in a finite number of principal components as in Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F(·,·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X(t) is a signal from diffusion tensor imaging at position, t, along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. R code for performing the simulations and fitting the FGAM can be found in supplemental materials available online.

  6. Nuclear power: sex differences in public opinion

    SciTech Connect

    Brody, C.J.

    1981-01-01

    This study attempts to determine the factors that account for the fact that women are both more opposed and uncertain than men concerning the further development of nuclear energy. To that end, data from four national opinion surveys covering the period 1975 to 1979 are employed. Log-linear techniques are used in the analyses. Two plausible explanations for women's greater aversion to nuclear power are presented. The marginality explanation attributes the differential support of men and women for nuclear power to the differential positions which they occupy in the economic, political, and technical spheres within society. Because men hold more central positions in these areas, it is postulated that they will perceive a greater need for additional energy and continued economic growth, believe that the advantages of nuclear power toward these goals are greater, and be more confident in applications of nuclear technology. The fact that men express more favorable attitudes toward nuclear power is thus to be explained by these factors. The safety explanation attributes the sex difference to a greater concern on the part of women about the safety of using nuclear fission to generate electricity. The general thrust of this arguments is that women's greater concern for safety revolves around their reproductive and nurturant roles, and the protection of future generations. Uncertainty is viewed as a special problem. An explanation for women's greater uncertainty, which attributes the difference to a sex-typed expectation concerning the formulation and expression of opinions on complex technical issues, is presented.

  7. Sex reversal triggers the rapid transition from genetic to temperature-dependent sex.

    PubMed

    Holleley, Clare E; O'Meally, Denis; Sarre, Stephen D; Marshall Graves, Jennifer A; Ezaz, Tariq; Matsubara, Kazumi; Azad, Bhumika; Zhang, Xiuwen; Georges, Arthur

    2015-07-02

    Sex determination in animals is amazingly plastic. Vertebrates display contrasting strategies ranging from complete genetic control of sex (genotypic sex determination) to environmentally determined sex (for example, temperature-dependent sex determination). Phylogenetic analyses suggest frequent evolutionary transitions between genotypic and temperature-dependent sex determination in environmentally sensitive lineages, including reptiles. These transitions are thought to involve a genotypic system becoming sensitive to temperature, with sex determined by gene-environment interactions. Most mechanistic models of transitions invoke a role for sex reversal. Sex reversal has not yet been demonstrated in nature for any amniote, although it occurs in fish and rarely in amphibians. Here we make the first report of reptile sex reversal in the wild, in the Australian bearded dragon (Pogona vitticeps), and use sex-reversed animals to experimentally induce a rapid transition from genotypic to temperature-dependent sex determination. Controlled mating of normal males to sex-reversed females produces viable and fertile offspring whose phenotypic sex is determined solely by temperature (temperature-dependent sex determination). The W sex chromosome is eliminated from this lineage in the first generation. The instantaneous creation of a lineage of ZZ temperature-sensitive animals reveals a novel, climate-induced pathway for the rapid transition between genetic and temperature-dependent sex determination, and adds to concern about adaptation to rapid global climate change.

  8. Creative musical behavior and sex hormones: musical talent and spatial ability in the two sexes.

    PubMed

    Hassler, M

    1992-01-01

    Creative musical behavior, musical intelligence, and spatial ability were investigated in relation to salivary testosterone (T). In a cross-sectional study with 117 adults and in an 8-yr longitudinal study with 120 adolescents, composers, instrumentalists, and nonmusicians of both sexes were compared by analyses of variance. Results indicate that an optimal T range may exist for the expression of creative musical behavior. This range may be at the bottom of normal male T range and at the top of normal female T range. In addition, musicians were found to attain significantly higher spatial test scores than nonmusicians, both, in an 8-yr-period of adolescent development and in adulthood.

  9. How sex hormones promote skeletal muscle regeneration.

    PubMed

    Velders, Martina; Diel, Patrick

    2013-11-01

    Skeletal muscle regeneration efficiency declines with age for both men and women. This decline impacts on functional capabilities in the elderly and limits their ability to engage in regular physical activity and to maintain independence. Aging is associated with a decline in sex hormone production. Therefore, elucidating the effects of sex hormone substitution on skeletal muscle homeostasis and regeneration after injury or disuse is highly relevant for the aging population, where sarcopenia affects more than 30 % of individuals over 60 years of age. While the anabolic effects of androgens are well known, the effects of estrogens on skeletal muscle anabolism have only been uncovered in recent times. Hence, the purpose of this review is to provide a mechanistic insight into the regulation of skeletal muscle regenerative processes by both androgens and estrogens. Animal studies using estrogen receptor (ER) antagonists and receptor subtype selective agonists have revealed that estrogens act through both genomic and non-genomic pathways to reduce leukocyte invasion and increase satellite cell numbers in regenerating skeletal muscle tissue. Although animal studies have been more conclusive than human studies in establishing a role for sex hormones in the attenuation of muscle damage, data from a number of recent well controlled human studies is presented to support the notion that hormonal therapies and exercise induce added positive effects on functional measures and lean tissue mass. Based on the fact that aging human skeletal muscle retains the ability to adapt to exercise with enhanced satellite cell activation, combining sex hormone therapies with exercise may induce additive effects on satellite cell accretion. There is evidence to suggest that there is a 'window of opportunity' after the onset of a hypogonadal state such as menopause, to initiate a hormonal therapy in order to achieve maximal benefits for skeletal muscle health. Novel receptor subtype selective

  10. Goals for Sex Equitable Sexuality Education.

    ERIC Educational Resources Information Center

    Whatley, Mariamne H.

    1987-01-01

    This article presents an overview of issues related to sex equity in sexuality education. Goals which might represent sex equitable sexuality education include eliminating double standards, and redefining sexuality education. (IAH)

  11. Talking to Your Kids about Sex

    MedlinePlus

    ... If you disagree for moral or religious reasons, love your child unconditionally. Remember, they may be fearful ... conversation. Talk to your child about sex and love. Teach them that hormones can confuse sex and ...

  12. Sex and the Man With Cancer

    MedlinePlus

    ... and Sexual Side Effects in People with Cancer Sex and the Man With Cancer In this guide, ... you and your partner some information about cancer, sex, and sexuality. We cannot answer every question, but ...

  13. Gambling, Sex, and…Parkinson's Disease?

    MedlinePlus

    ... spent, browse our financial information. Learn More Gambling, Sex, and…Parkinson's Disease? By Laura Marsh, M.D. ... and, in people with Parkinson's, most typically involve sex, gambling and abuse of anti-parkinsonian medications. Pathological ...

  14. Sex, Sexuality, Sexting, and SexEd: Adolescents and the Media

    ERIC Educational Resources Information Center

    Brown, Jane D.; Keller, Sarah; Stern, Susannah

    2009-01-01

    The traditional media (television, radio, movies, magazines) and new, digital media (the Internet, Social Networking Sites such as Facebook and Myspace, and cell phones) have become important sex educators for adolescents. Adolescents in the United States spend six to seven hours a day with some form of media, often using more than one kind…

  15. Sex as a response to oxidative stress: a twofold increase in cellular reactive oxygen species activates sex genes.

    PubMed

    Nedelcu, Aurora M; Marcu, Oana; Michod, Richard E

    2004-08-07

    Organisms are constantly subjected to factors that can alter the cellular redox balance and result in the formation of a series of highly reactive molecules known as reactive oxygen species (ROS). As ROS can be damaging to biological structures, cells evolved a series of mechanisms (e.g. cell-cycle arrest, programmed cell death) to respond to high levels of ROS (i.e. oxidative stress). Recently, we presented evidence that in a facultatively sexual lineage--the multicellular green alga Volvox carteri--sex is an additional response to increased levels of stress, and probably ROS and DNA damage. Here we show that, in V. carteri, (i) sex is triggered by an approximately twofold increase in the level of cellular ROS (induced either by the natural sex-inducing stress, namely heat, or by blocking the mitochondrial electron transport chain with antimycin A), and (ii) ROS are responsible for the activation of sex genes. As most types of stress result in the overproduction of ROS, we believe that our findings will prove to extend to other facultatively sexual lineages, which could be indicative of the ancestral role of sex as an adaptive response to stress and ROS-induced DNA damage.

  16. Decreasing Human Trafficking through Sex Work Decriminalization.

    PubMed

    Albright, Erin; D'Adamo, Kate

    2017-01-01

    In order to decrease human trafficking, health care workers should support the full decriminalization of prostitution. Similar to trafficking in other forms of labor, preventing trafficking in the sex trade requires addressing the different forms of marginalization that create vulnerable communities. By removing punitive laws that prevent reporting of exploitation and abuse, decriminalization allows sex workers to work more safely, thereby reducing marginalization and vulnerability. Decriminalization can also help destigmatize sex work and help resist political, social, and cultural marginalization of sex workers.

  17. Siloxane containing addition polyimides

    NASA Technical Reports Server (NTRS)

    Maudgal, S.; St. Clair, T. L.

    1984-01-01

    Addition polyimide oligomers have been synthesized from bis(gamma-aminopropyl) tetramethyldisiloxane and 3, 3', 4, 4'-benzophenonetetracarboxylic dianhydride using a variety of latent crosslinking groups as endcappers. The prepolymers were isolated and characterized for solubility (in amide, chlorinated and ether solvents), melt flow and cure properties. The most promising systems, maleimide and acetylene terminated prepolymers, were selected for detailed study. Graphite cloth reinforced composites were prepared and properties compared with those of graphite/Kerimid 601, a commercially available bismaleimide. Mixtures of the maleimide terminated system with Kerimid 601, in varying proportions, were also studied.

  18. Vulnerability re-assessed: the changing face of sex work in Guntur district, Andhra Pradesh.

    PubMed

    Beattie, Tara S H; Bradley, Janet E; Vanta, Uma Devi; Lowndes, Catherine M; Alary, Michel

    2013-01-01

    We conducted a qualitative study to examine the impact of an HIV prevention programme on female sex workers' lives in Guntur district, Andhra Pradesh. The study found evidence that, in addition to the HIV prevention programme, structural and environmental factors had recently changed the way sex work was being practiced. Recent closure of the brothels and implementation of a late-night street curfew by the police meant sex work had become more hidden, with clients often solicited using mobile phones from home or their work place (e.g., in the fields or factories). Sex work had become safer, with violence by non-regular partners rarely reported. Women understood the risks of unprotected vaginal sex and reported using condoms with their clients. However, clients were more frequently requesting anal sex, possibly due to recent exposure to pornography following increased accessibility to modern technologies such as mobile phones and the Internet. Anal sex with clients was common but women were often unaware of the associated risks and reported unprotected anal sex. HIV positive and/or older women faced severe financial hardship and difficulty soliciting sufficient clients, and reported unprotected vaginal and anal sex to earn enough to survive. Taken together, the findings from this study suggest changing vulnerability to HIV in this setting. It will be important for HIV prevention programmes to be flexible and creative in their approaches if they are to continue to reach this target community effectively.

  19. Identification of sex-specific molecular markers using restriction site-associated DNA sequencing.

    PubMed

    Gamble, Tony; Zarkower, David

    2014-09-01

    A major barrier to evolutionary studies of sex determination and sex chromosomes has been a lack of information on the types of sex-determining mechanisms that occur among different species. This is particularly problematic in groups where most species lack visually heteromorphic sex chromosomes, such as fish, amphibians and reptiles, because cytogenetic analyses will fail to identify the sex chromosomes in these species. We describe the use of restriction site-associated DNA (RAD) sequencing, or RAD-seq, to identify sex-specific molecular markers and subsequently determine whether a species has male or female heterogamety. To test the accuracy of this technique, we examined the lizard Anolis carolinensis. We performed RAD-seq on seven male and ten female A. carolinensis and found one male-specific molecular marker. Anolis carolinensis has previously been shown to possess male heterogamety and the recently published A. carolinensis genome facilitated the characterization of the sex-specific RAD-seq marker. We validated the male specificity of the new marker using PCR on additional individuals and also found that it is conserved in some other Anolis species. We discuss the utility of using RAD-seq to identify sex-determining mechanisms in other species with cryptic or homomorphic sex chromosomes and the implications for the evolution of male heterogamety in Anolis.

  20. Why sex matters: brain size independent differences in gray matter distributions between men and women.

    PubMed

    Luders, Eileen; Gaser, Christian; Narr, Katherine L; Toga, Arthur W

    2009-11-11

    The different brain anatomy of men and women is both a classic and continuing topic of major interest. Among the most replicated and robust sex differences are larger overall brain dimensions in men, and relative increases of global and regional gray matter (GM) in women. However, the question remains whether sex-typical differences in brain size (i.e., larger male and smaller female brains) or biological sex itself account for the observed sex effects on tissue amount and distribution. Exploring cerebral structures in men and women with similar brain size may clarify the true contribution of biological sex. We thus examined a sample of 24 male and 24 female subjects with brains identical in size, in addition to 24 male and 24 female subjects with considerable brain size differences. Using this large set of brains (n = 96), we applied a well validated and automated voxel-based approach to examine regional volumes of GM. While we revealed significant main effects of sex, there were no significant effects of brain size (and no significant interactions between sex and brain size). When conducting post hoc tests, we revealed a number of regions where women had larger GM volumes than men. Importantly, these sex effects remained evident when comparing men and women with the same brain size. Altogether, our findings suggest that the observed increased regional GM volumes in female brains constitute sex-dependent redistributions of tissue volume, rather than individual adjustments attributable to brain size.

  1. Platelet additive solution - electrolytes.

    PubMed

    Azuma, Hiroshi; Hirayama, Junichi; Akino, Mitsuaki; Ikeda, Hisami

    2011-06-01

    Recent attention to solutions that replace most or all plasma in platelet concentrates, while maintaining satisfactory platelet function, is motivated by the potential of plasma reduction or depletion to mitigate various transfusion-related adverse events. This report considers the electrolytic composition of previously described platelet additive solutions, in order to draw general conclusions about what is required for platelet function and longevity. The optimal concentrations of Na(+) and Cl(-) are 69-115 mM. The presence of both K(+) and Mg(2+) in platelet suspension at nearly physiological concentrations (3-5mM and 1.5-3mM, respectively) is indispensable for good preservation capacity because both electrolytes are required to prevent platelet activation. In contrast to K(+) and Mg(2+), Ca(2+) may not be important because no free Ca(2+) is available in M-sol, which showed excellent platelet preservation capacity at less than 5% plasma concentration. The importance of bicarbonate (approximately 40 mM) can be recognized when the platelets are suspended in additive solution under less than 5% residual plasma concentration.

  2. Sex Stereotypes and Responses to Juvenile Delinquency.

    ERIC Educational Resources Information Center

    Willemsen, Tineke M.; van Schie, Els C. M.

    1989-01-01

    Describes two studies to test the following hypotheses: (1) delinquent behavior that corresponds to sex stereotypes will be punished more severely; and (2) delinquent behavior that deviates will be evaluated more negatively. Presents model illustrating how sex stereotypes about delinquent behavior lead to sex-related differences in attribution and…

  3. ``Sex Hormones'' in Secondary School Biology Textbooks

    NASA Astrophysics Data System (ADS)

    Nehm, Ross H.; Young, Rebecca

    2008-11-01

    This study explores the extent to which the term “sex hormone” is used in science textbooks, and whether the use of the term “sex hormone” is associated with pre-empirical concepts of sex dualism, in particular the misconceptions that these so-called “sex hormones” are sex specific and restricted to sex-related physiological functioning. We found that: (1) all the texts employed the term “sex hormone”; (2) in all texts estrogen is characterized as restricted to females and testosterone is characterized as restricted to males; and (3) in all texts testosterone and estrogen are discussed as exclusively involved in sex-related physiological roles. We conclude that (1) contemporary science textbooks preserve sex-dualistic models of steroid hormones (one sex, one “sex hormone”) that were rejected by medical science in the early 20th century and (2) use of the term “sex hormone” is associated with misconceptions regarding the presence and functions of steroid hormones in male and female bodies.

  4. The Advantages of Single-Sex Education

    ERIC Educational Resources Information Center

    Hughes, Teresa A.

    2006-01-01

    Traditionally, single-sex education has been provided in the form of private schooling. Title IX regulations have loosened as a result of the No Child Left Behind Legislation; therefore, public school districts now have the legal right to create single-sex classes or single-sex schools if they deem it to be in the best interest of their students.…

  5. The Promise of Single-Sex Classes

    ERIC Educational Resources Information Center

    Stotsky, Sandra

    2012-01-01

    Despite the enthusiasm and the absence of definitive research on the pros and cons of single-sex classes, a 2011 article in Science, titled "The Pseudoscience of Single-Sex Schooling," by a new organization called American Council for CoEducational Schooling (ACCES) came out with the astonishing conclusion that single-sex education is…

  6. Working Together: A Sex Equity Training Manual.

    ERIC Educational Resources Information Center

    Baldwin, Jill, Comp.; Kielbaso, Gloria, Comp.

    This manual contains nine learning modules on sex equity topics contributed by state sex equity personnel from Arizona, Colorado, Illinois, Michigan, Nebraska, Ohio, New York, Nevada, and Virginia. Each module provides one or more lesson plans for learning activities that combat traditional sex role stereotypes and behaviors. Information is…

  7. Sexual Stratification and Sex-Role Socialization

    ERIC Educational Resources Information Center

    VanFossen, Beth Ensiminger

    1977-01-01

    Data on sex-role values of a sample of college women are examined to ascertain the effect of family structure, social class, and religion on sex-role values, and to support a structural theory of sex-role socialization. (Author)

  8. Analyzing Medical Students' Definitions of Sex

    ERIC Educational Resources Information Center

    Talley, Heather; Cho, Janice; Strassberg, Donald S.; Rullo, Jordan E.

    2016-01-01

    An inaccurate definition of what constitutes sex can negatively impact the sexual health and wellbeing of patients. This study aimed to determine which behaviors medical students consider to be sex. Survey questions about various sexual behaviors were administered to medical students. All participants agreed that penile-vaginal penetration is sex.…

  9. Cultural Variations in Sex-Typing.

    ERIC Educational Resources Information Center

    Basow, Susan A.

    1984-01-01

    Results of Personal Attributes Questionnaire administered to Fijian secondary and university students showed: (1) no sex differences in sex-typing patterns; (2) same-sex-typing as much less marked than in the United States; (3) minor variations among Fijian ethnic groups; and (4) university students as more similar than secondary students to U.S.…

  10. Sex Steroid Signaling: Implications for Lung Diseases

    PubMed Central

    Sathish, Venkatachalem; Martin, Yvette N.; Prakash, Y.S.

    2015-01-01

    There is increasing recognition that the sex hormones (estrogen, progesterone, and testosterone) have biological and pathophysiological actions in peripheral, non-reproductive organs, including the lung. Clinically, sex differences in the incidence, morbidity and mortality of lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, lung cancer and pulmonary hypertension have been noted, although intrinsic sex differences vs. the roles of sex steroids are still not well-understood. Accordingly, it becomes important to ask the following questions: 1) Which sex steroids are involved? 2) How do they affect different components of the lung under normal circumstances? 3) How does sex steroid signaling change in or contribute to lung disease, and in this regard, are sex steroids detrimental or beneficial? As our understanding of sex steroid signaling in the lung improves, it is important to consider whether such information can be used to develop new therapeutic strategies to target lung diseases, perhaps in both sexes or in a sex-specific manner. In this review, we focus on the basics of sex steroid signaling, and the current state of knowledge regarding how they influence structure and function of specific lung components across the life span and in the context of some important lung diseases. We then summarize the potential for sex steroids as useful biomarkers and therapeutic targets in these lung diseases as a basis for future translational research in the area of gender and individualized medicine. PMID:25595323

  11. Sex Equity in Public Education. Issuegram 35.

    ERIC Educational Resources Information Center

    Lines, Patricia M.; And Others

    Sex discrimination in American education remains a persistent problem that requires concerted attention from many different perspectives. This Issuegram focuses on the legal mandates requiring sex equity in public schools. A brief background indicates a history of sex discrimination in education dating back to 1783. Several important weapons for…

  12. 77 FR 73558 - Sex Offender Registration Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-11

    ... COLUMBIA 28 CFR Part 811 RIN 3225-AA10 Sex Offender Registration Amendments AGENCY: Court Services and... verification of registration information for sex offenders. The proposed rule, if finalized, would permit CSOSA to verify addresses of sex offenders by conducting home visits on its own accord and with its...

  13. 78 FR 23835 - Sex Offender Registration Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... SUPERVISION AGENCY FOR THE DISTRICT OF COLUMBIA 28 CFR Part 811 RIN 3225-AA10 Sex Offender Registration... verification of registration information for sex offenders. Furthermore, the rule permits CSOSA to verify addresses of sex offenders by conducting home visits on its own accord and with its law enforcement...

  14. Sex Role Identity and Adjustment during Adolescence.

    ERIC Educational Resources Information Center

    Massad, Christopher M.

    1981-01-01

    Examined the relationship between sex role identity and two measures of adjustment--self-acceptance and peer acceptance--among adolescents. Sex differences were discovered regarding factors positively associated with self-acceptance. Findings suggest that a model of sex role differentiation during adolescence must recognize differential pressures…

  15. Deciphering evolutionary strata on plant sex chromosomes and fungal mating-type chromosomes through compositional segmentation.

    PubMed

    Pandey, Ravi S; Azad, Rajeev K

    2016-03-01

    Sex chromosomes have evolved from a pair of homologous autosomes which differentiated into sex determination systems, such as XY or ZW system, as a consequence of successive recombination suppression between the gametologous chromosomes. Identifying the regions of recombination suppression, namely, the "evolutionary strata", is central to understanding the history and dynamics of sex chromosome evolution. Evolution of sex chromosomes as a consequence of serial recombination suppressions is well-studied for mammals and birds, but not for plants, although 48 dioecious plants have already been reported. Only two plants Silene latifolia and papaya have been studied until now for the presence of evolutionary strata on their X chromosomes, made possible by the sequencing of sex-linked genes on both the X and Y chromosomes, which is a requirement of all current methods that determine stratum structure based on the comparison of gametologous sex chromosomes. To circumvent this limitation and detect strata even if only the sequence of sex chromosome in the homogametic sex (i.e. X or Z chromosome) is available, we have developed an integrated segmentation and clustering method. In application to gene sequences on the papaya X chromosome and protein-coding sequences on the S. latifolia X chromosome, our method could decipher all known evolutionary strata, as reported by previous studies. Our method, after validating on known strata on the papaya and S. latifolia X chromosome, was applied to the chromosome 19 of Populus trichocarpa, an incipient sex chromosome, deciphering two, yet unknown, evolutionary strata. In addition, we applied this approach to the recently sequenced sex chromosome V of the brown alga Ectocarpus sp. that has a haploid sex determination system (UV system) recovering the sex determining and pseudoautosomal regions, and then to the mating-type chromosomes of an anther-smut fungus Microbotryum lychnidis-dioicae predicting five strata in the non

  16. Manipulation of offspring sex ratio by second-mated female house wrens.

    PubMed Central

    Albrecht, Daniel J; Johnson, L Scott

    2002-01-01

    In 1973, Trivers and Willard proposed that offspring sex ratio should be associated with the quality of parental care likely to be provided to the offspring. We tested this hypothesis by comparing fledgling sex ratios in nests of first- and second-mated female house wrens (Troglodytes aedon). In our Wyoming population, second-mated females typically receive little or no male parental assistance and fledge fewer and lower-quality young compared with first-mated females. Assuming that being of lower quality has stronger negative effects on the future reproductive success of males than that of females in this polygynous population, we predicted that fledgling sex ratios in the nests of second-mated females would be female-biased compared with the fledgling sex ratios of first-mated females. Additionally, we asked whether any sex bias at fledging could have resulted from male-biased nestling mortality caused by sex-biased parental provisioning. As predicted, mean fledgling sex ratios in nests of second-mated females were more female-biased than fledgling sex ratios in nests of first-mated females. However, we found no evidence of either sex-biased nestling mortality or sex-biased parental provisioning. These findings suggest that females are responding to their status as second-mated females and to the associated low-quality parental care that their young are likely to receive by producing female-biased clutches rather than manipulating the offspring sex ratio through sex-biased nestling mortality. PMID:11886637

  17. Evolution of Dosage Compensation in Anolis carolinensis, a Reptile with XX/XY Chromosomal Sex Determination

    PubMed Central

    Rupp, Shawn M.; Webster, Timothy H.; Olney, Kimberly C.; Hutchins, Elizabeth D.; Kusumi, Kenro

    2017-01-01

    In species with highly heteromorphic sex chromosomes, the degradation of one of the sex chromosomes will result in unequal gene expression between the sexes (e.g. between XX females and XY males) and between the sex chromosomes and the autosomes. Dosage compensation is a process whereby genes on the sex chromosomes achieve equal gene expression. We compared genome-wide levels of transcription between males and females, and between the X chromosome and the autosomes in the green anole, Anolis carolinensis. We present evidence for dosage compensation between the sexes, and between the sex chromosomes and the autosomes. When dividing the X chromosome into regions based on linkage groups, we discovered that genes in the first reported X-linked region, anole linkage group b (LGb), exhibit complete dosage compensation, although the rest of the X-linked genes exhibit incomplete dosage compensation. Our data further suggest that the mechanism of this dosage compensation is upregulation of the X chromosome in males. We report that approximately 10% of coding genes, most of which are on the autosomes, are differentially expressed between males and females. In addition, genes on the X chromosome exhibited higher ratios of nonsynonymous to synonymous substitution than autosomal genes, consistent with the fast-X effect. Our results from the green anole add an additional observation of dosage compensation in a species with XX/XY sex determination. PMID:28206607

  18. A neo-sex-chromosome that drives post-zygotic sex determiniation in the Hessian fly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two nonoverlapping autosomal inversions defined unusual neo-sex chromosomes in the Hessian fly (Mayetiola destructor). Like other neo-sex chromosomes, these were normally heterozygous, present only in one sex, and suppressed recombination around a sex-determining master switch. Their unusual propert...

  19. Single-sex middle school science classrooms: Separate and equal?

    NASA Astrophysics Data System (ADS)

    Glasser, Howard M.

    The U.S. Department of Education's amended regulations to Title IX have attempted to expand the circumstances in which single-sex classes are permissible in public schools. This ethnographic study uses grounded theory to investigate aspects of one single-sex offering at a public, coeducational middle school. Applying elements of postmodern, queer, and sociocultural lenses, it examines the perspectives for this offering, shedding insight into the cultures of two single-sex classrooms and what it meant to be a boy or girl in this setting. Additionally, it focuses attention on the all-boy and all-girl science classes that were taught by the same teacher and examines what it meant to learn science as boys and girls in this program. Although participants supplied financial, socio-emotional, and academic reasons for these classes, the initial motivation for these classes stemmed from the teachers' desire to curb the amount of sex talk and related behaviors that were exhibited in their classrooms. Through these conversations and classroom events, the girls were constructed as idealized students, academically and behaviorally, who needed to be protected from boys' behaviors---both boys' dominating classroom behaviors and aggressive (hetero)sexual behaviors. Conversely, boys were constructed as needing help both academically and behaviorally, but in the specific discipline of science boys were identified as the sex that was more interested in the content and gained greater exposure to skills that could assist them in future science courses and careers. Overall, boys and girls, and the culture of their two classrooms, were regularly defined relative to each other and efforts were made to maintain these constructed differences. As a result, the classes and students were hierarchically ranked in ways that often pitted one sex of students, or the entire class, as better or worse than the other. The theory emerging from this study is that single-sex policies arise and survive

  20. Discounting of food, sex, and money.

    PubMed

    Holt, Daniel D; Newquist, Matthew H; Smits, Rochelle R; Tiry, Andrew M

    2014-06-01

    Discounting is a useful framework for understanding choice involving a range of delayed and probabilistic outcomes (e.g., money, food, drugs), but relatively few studies have examined how people discount other commodities (e.g., entertainment, sex). Using a novel discounting task, where the length of a line represented the value of an outcome and was adjusted using a staircase procedure, we replicated previous findings showing that individuals discount delayed and probabilistic outcomes in a manner well described by a hyperbola-like function. In addition, we found strong positive correlations between discounting rates of delayed, but not probabilistic, outcomes. This suggests that discounting of delayed outcomes may be relatively predictable across outcome types but that discounting of probabilistic outcomes may depend more on specific contexts. The generality of delay discounting and potential context dependence of probability discounting may provide important information regarding factors contributing to choice behavior.

  1. Sex without sex chromosomes: genetic architecture of multiple loci independently segregating to determine sex ratios in the copepod Tigriopus californicus.

    PubMed

    Alexander, H J; Richardson, J M L; Edmands, S; Anholt, B R

    2015-12-01

    Sex-determining systems are remarkably diverse and may evolve rapidly. Polygenic sex-determination systems are predicted to be transient and evolutionarily unstable, yet examples have been reported across a range of taxa. Here, we provide the first direct evidence of polygenic sex determination in Tigriopus californicus, a harpacticoid copepod with no heteromorphic sex chromosomes. Using genetically distinct inbred lines selected for male- and female-biased clutches, we generated a genetic map with 39 SNPs across 12 chromosomes. Quantitative trait locus mapping of sex ratio phenotype (the proportion of male offspring produced by an F2 female) in four F2 families revealed six independently segregating quantitative trait loci on five separate chromosomes, explaining 19% of the variation in sex ratios. The sex ratio phenotype varied among loci across chromosomes in both direction and magnitude, with the strongest phenotypic effects on chromosome 10 moderated to some degree by loci on four other chromosomes. For a given locus, sex ratio phenotype varied in magnitude for individuals derived from different dam lines. These data, together with the environmental factors known to contribute to sex determination, characterize the underlying complexity and potential lability of sex determination, and confirm the polygenic architecture of sex determination in T. californicus.

  2. Additive composition, for gasoline

    SciTech Connect

    Vataru, M.

    1989-01-10

    An admixture is described that comprises Diesel fuel and an additive composition added thereto which is between about 0.05 to about 2.0 percent by weight of the fuel, the composition comprising: (a) between about 0.05 and 25% relative weight parts of an organic peroxide, and (b) between about 0.1 and 25% relative weight parts of detergent selected from the component group that consists of: (i) fatty amines; (ii) ethoxylated and propoxylated derivatives of fatty amines; (iii) fatty diamines; (iv) fatty imidazlines; (v) polymeric amines and derivatives thereof; (vi) combination of one or more of the (i) through (v) components with carboxylic acid or acids having from three to forth carbon atoms, (c) from about 99.0 to about 50% by weight of a hydrocarbon solvent.

  3. Teardrop bladder: additional considerations

    SciTech Connect

    Wechsler, R.J.; Brennan, R.E.

    1982-07-01

    Nine cases of teardrop bladder (TDB) seen at excretory urography are presented. In some of these patients, the iliopsoas muscles were at the upper limit of normal in size, and additional evaluation of the perivesical structures with computed tomography (CT) was necessary. CT demonstrated only hypertrophied muscles with or without perivesical fat. The psoas muscles and pelvic width were measured in 8 patients and compared with the measurements of a control group of males without TDB. Patients with TDB had large iliopsoas muscles and narrow pelves compared with the control group. The psoas muscle width/pelvic width ratio was significantly greater (p < 0.0005) in patients with TDB than in the control group, with values of 1.04 + 0.05 and 0.82 + 0.09, respectively. It is concluded that TDB is not an uncommon normal variant in black males. Both iliopsoas muscle hypertrophy and a narrow pelvis are factors that predispose a patient to TDB.

  4. New addition curing polyimides

    NASA Technical Reports Server (NTRS)

    Frimer, Aryeh A.; Cavano, Paul

    1991-01-01

    In an attempt to improve the thermal-oxidative stability (TOS) of PMR-type polymers, the use of 1,4-phenylenebis (phenylmaleic anhydride) PPMA, was evaluated. Two series of nadic end-capped addition curing polyimides were prepared by imidizing PPMA with either 4,4'-methylene dianiline or p-phenylenediamine. The first resulted in improved solubility and increased resin flow while the latter yielded a compression molded neat resin sample with a T(sub g) of 408 C, close to 70 C higher than PME-15. The performance of these materials in long term weight loss studies was below that of PMR-15, independent of post-cure conditions. These results can be rationalized in terms of the thermal lability of the pendant phenyl groups and the incomplete imidization of the sterically congested PPMA. The preparation of model compounds as well as future research directions are discussed.

  5. Perspectives on Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Bourell, David L.

    2016-07-01

    Additive manufacturing (AM) has skyrocketed in visibility commercially and in the public sector. This article describes the development of this field from early layered manufacturing approaches of photosculpture, topography, and material deposition. Certain precursors to modern AM processes are also briefly described. The growth of the field over the last 30 years is presented. Included is the standard delineation of AM technologies into seven broad categories. The economics of AM part generation is considered, and the impacts of the economics on application sectors are described. On the basis of current trends, the future outlook will include a convergence of AM fabricators, mass-produced AM fabricators, enabling of topology optimization designs, and specialization in the AM legal arena. Long-term developments with huge impact are organ printing and volume-based printing.

  6. Sewage sludge additive

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Mueller, W. A.; Ingham, J. D. (Inventor)

    1980-01-01

    The additive is for a raw sewage treatment process of the type where settling tanks are used for the purpose of permitting the suspended matter in the raw sewage to be settled as well as to permit adsorption of the dissolved contaminants in the water of the sewage. The sludge, which settles down to the bottom of the settling tank is extracted, pyrolyzed and activated to form activated carbon and ash which is mixed with the sewage prior to its introduction into the settling tank. The sludge does not provide all of the activated carbon and ash required for adequate treatment of the raw sewage. It is necessary to add carbon to the process and instead of expensive commercial carbon, coal is used to provide the carbon supplement.

  7. Fish with thermolabile sex determination (TSD) as models to study brain sex differentiation.

    PubMed

    Blázquez, Mercedes; Somoza, Gustavo M

    2010-05-01

    As fish are ectothermic animals, water temperature can affect their basic biological processes such as larval development, growth and reproduction. Similar to reptiles, the incubation temperature during early phases of development is capable to modify sex ratios in a large number of fish species. This phenomenon, known as thermolabile sex determination (TSD) was first reported in Menidia menidia, a species belonging to the family Atherinopsidae. Since then, an increasing number of fish have also been found to exhibit TSD. Traditionally, likewise in reptiles, several TSD patterns have been described in fish, however it has been recently postulated that only one, females at low temperatures and males at high temperatures, may represent the "real" or "true" TSD. Many studies regarding the influence of temperature on the final sex ratios have been focused on the expression and activity of gonadal aromatase, the enzyme involved in the conversion of androgens into estrogens and encoded by the cyp19a1a gene. In this regard, teleost fish, may be due to a whole genome duplication event, produce another aromatase enzyme, commonly named brain aromatase, encoded by the cyp19a1b gene. Contrary to what has been described in other vertebrates, fish exhibit very high levels of aromatase activity in the brain and therefore they synthesize high amounts of neuroestrogens. However, its biological significance is still not understood. In addition, the mechanism whereby temperature can induce the development of a testis or an ovary still remains elusive. In this context the present review is aimed to discuss several theories about the possible role of brain aromatase using fish as models. The relevance of brain aromatase and therefore of neuroestrogens as the possible cue for gonadal differentiation is raised. In addition, the possible role of brain aromatase as the way to keep the high levels of neurogenesis in fish is also considered. Several key examples of how teleosts and aromatase

  8. Sex differences in addictive disorders.

    PubMed

    Fattore, Liana; Melis, Miriam; Fadda, Paola; Fratta, Walter

    2014-08-01

    Gender-dependent differences in the rate of initiation and frequency of misuse of addicting drugs have been widely described. Yet, men and women also differ in their propensity to become addicted to other rewarding stimuli (e.g., sex, food) or activities (e.g., gambling, exercising). The goal of the present review is to summarize current evidence for gender differences not only in drug addiction, but also in other forms of addictive behaviours. Thus, we first reviewed studies showing gender-dependent differences in drug addiction, food addiction, compulsive sexual activity, pathological gambling, Internet addiction and physical exercise addiction. Potential risk factors and underlying brain mechanisms are also examined, with particular emphasis given to the role of sex hormones in modulating addictive behaviours. Investigations on factors allowing the pursuit of non-drug rewards to become pathological in men and women are crucial for designing gender-appropriate treatments of both substance and non-substance addictions.

  9. Polygenic Sex Determination System in Zebrafish

    PubMed Central

    Liew, Woei Chang; Bartfai, Richard; Lim, Zijie; Sreenivasan, Rajini; Siegfried, Kellee R.; Orban, Laszlo

    2012-01-01

    Background Despite the popularity of zebrafish as a research model, its sex determination (SD) mechanism is still unknown. Most cytogenetic studies failed to find dimorphic sex chromosomes and no primary sex determining switch has been identified even though the assembly of zebrafish genome sequence is near to completion and a high resolution genetic map is available. Recent publications suggest that environmental factors within the natural range have minimal impact on sex ratios of zebrafish populations. The primary aim of this study is to find out more about how sex is determined in zebrafish. Methodology/Principal Findings Using classical breeding experiments, we found that sex ratios across families were wide ranging (4.8% to 97.3% males). On the other hand, repeated single pair crossings produced broods of very similar sex ratios, indicating that parental genotypes have a role in the sex ratio of the offspring. Variation among family sex ratios was reduced after selection for breeding pairs with predominantly male or female offspring, another indication that zebrafish sex is regulated genetically. Further examinations by a PCR-based “blind assay" and array comparative genomic hybridization both failed to find universal sex-linked differences between the male and female genomes. Together with the ability to increase the sex bias of lines by selective breeding, these data suggest that zebrafish is unlikely to utilize a chromosomal sex determination (CSD) system. Conclusions/Significance Taken together, our study suggests that zebrafish sex is genetically determined with limited, secondary influences from the environment. As we have not found any sign for CSD in the species, we propose that the zebrafish has a polygenic sex determination system. PMID:22506019

  10. Sex determination in beef by melting curve analysis of PCR amplicons from the amelogenin locus.

    PubMed

    Ballin, Nicolai Z; Madsen, Knud G

    2007-11-01

    Sex determination of beef is important to meet the rules of the Commission Regulation (EC) 765/2002 that qualify for export refunds. A SYBR Green sex identification assay based on melting curve analysis of PCR amplicons from the amelogenin locus (AMELX and AMELY) was developed. The PCR amplicons of 130/130 and 130/67 base pairs produced from female and male beef, respectively, are easily distinguished by both melting curve analysis and gel electrophoresis. Results from the melting curve analysis of amplicons are ready in less than three minutes, and requires no additional work in addition to the PCR setup. Applicability of the sex determination assay was studied by analysis of 12 unknown beef samples and the results were compared to an accredited method based on gel electrophoresis. In addition, six different cattle breeds were examined. All test results were correct in respect to sex.

  11. Are female sex hormones teratogenic?

    PubMed

    Wilson, J G; Brent, R L

    1981-11-01

    An analysis of available epidemiologic data leads the present reviewers to conclude that the use of exogenous hormones during human pregnancy has not been proved to cause developmental abnormality in nongenital organs and tissues. This conclusion is further supported by the animal laboratory data. The preponderance of evidence at this writing indicates a lack of causal association between hormonal use during pregnancy and nongenital malformation of the offspring. The quality of the epidemiologic data does not, at this time, permit a definitive conclusion that sex hormones during pregnancy may not, under as yet to be defined conditions, have some adverse effect on human prenatal development. If there are increased risks of nongenital malformations associated with the administration of certain sex steroids, the risks are very small, may not be causal, and are substantially below the spontaneous risk of malformations. In spite of the present degree of uncertainty, the clinical, epidemiologic, and laboratory data do permit the formulation of a rational approach to handling problems related to sex steroid usage and exposure in pregnant women.

  12. [Does really sex addiction exist?].

    PubMed

    Echeburúa, Enrique

    2012-01-01

    Hypersexual Disorder has been proposed as a new psychiatric disorder for DSM-V, characterized by an increased frequency and intensity of sexually motivated fantasies, arousal, urges, and enacted behavior in association with an impulsivity component. Excessive appetitive and consummatory behaviors, including hypersexuality, can become a non-chemical addiction. Sexual addiction afflicts people having paraphilic or nonparaphilic behaviors associated with progressive risk-taking sexual behaviors, escalation or progression of sexual behaviors (tolerance), loss of control and significant adverse psychosocial consequences, such as unplanned pregnancy, pair-bond dysfunction, marital separation, financial problems and sexually transmitted diseases including HIV. The most common behaviors involved in sexual addiction are fantasy sex, compulsive masturbation, pornography, cybersex, voyeuristic sex, anonymous sex and multiple sexual partners. These behaviors are intended to reduce anxiety and other dysphoric affects (e.g., shame and depression). Axis I psychiatric diagnosis, especially mood disorders, psychoactive substance abuse disorders and attention deficit hyperactivity disorders, are common comorbid disorders with sexual addiction. There are significant gaps in the current scientific knowledge base regarding the clinical course, development risk factors and family history and data on women with sexual addiction are lacking.

  13. Sex role ideology among physicians.

    PubMed Central

    Leichner, P.; Harper, D.

    1982-01-01

    Physicians have been accused by some feminist writers of having traditional views on sex roles that make them part of society's oppressive power structure and therefore responsible in part for the high incidence of psychologic problems and drug dependency among women. To assess whether physicians' attitudes towards women are indeed polarized in a traditional fashion, a sex role ideology questionnaire was given to all practising physicians belonging to the Manitoba Medical Association. Overall the physicians were found to be more feminist than male college students and a group of women with traditional beliefs. Psychiatrists, who had the highest adjusted group mean score on a sex role ideology scale (high indicating feminist beliefs), were found to be significantly more feminist than family practitioners, surgeons, and obstetricians and gynecologists, although not more so than internists, radiologists, pediatricians and anesthesiologists. These findings do not support the assumption that physicians have traditional views that reflect those of society. However, the significant differences between specialties emphasize the need for educating physicians and medical students in the behaviour of women. PMID:7104916

  14. Sex trafficking in South Asia.

    PubMed

    Huda, S

    2006-09-01

    Economic and social inequalities and political conflicts have led to the movement of persons within each country and across the borders in South Asia. Globalization has encouraged free mobility of capital, technology, experts and sex tourism. Illiteracy, dependency, violence, social stigma, cultural stereotypes, gender disparity and endemic poverty, among other factors, place women and children in powerless, non-negotiable situations that have contributed to the emergence and breeding of the cavernous problem of sex trafficking in the entire region. This alarming spread of sex trafficking has fuelled the spread of HIV infection in South Asia, posing a unique and serious threat to community health, poverty alleviation and other crucial aspects of human development. Although the SAARC (South Asian Association for Regional Cooperation) Convention on Trafficking in Women and Children has been an important breakthrough, most of the countries in the region do not have anti-trafficking legislation or means to protect the victims. Countries of the region should make a concerted effort to treat trafficking victims as "victims" of human rights violations in all anti-trafficking strategies and actions.

  15. Condom ads promote illicit sex.

    PubMed

    Kippley, J F

    1994-01-01

    Written in 1987, this opinion was republished in the wake of US President Bill Clinton's AIDS prevention media campaign promoting condom use which began January 1994, targeted at young adults aged 18-25. The author staunchly opposes condom use even though he admits that people do not consider abstinence from sex to be a serious option for the prevention of HIV/STD infection. He believes that there is no moral use of sex with a condom and that condoms have always been a sign of immorality, be it prostitution, adultery, fornication, or marital contraception. Likewise, the author laments the success enjoyed by Planned Parenthood in achieving the social acceptance of marital contraception and sex outside of marriage. The complete social acceptance of homosexual activity, however, remains to be achieved. Magazines, newspapers, and television receive income in exchange for publishing or airing advertisements. Finding offensive advertisements which promote the use of condoms against HIV infection, the author recommends writing letters of complaint to the responsible media sources. If the television stations or publications in question continue to advertise condoms to the public, stop watching them or end one's subscriptions to the particular printed media. Such action taken collectively among many individuals will reduce product sales and income, and potentially sway corporate policy against condom ads.

  16. Same Sex Marriage and the Perceived Assault on Opposite Sex Marriage

    PubMed Central

    Dinno, Alexis; Whitney, Chelsea

    2013-01-01

    Background Marriage benefits both individuals and societies, and is a fundamental determinant of health. Until recently same sex couples have been excluded from legally recognized marriage in the United States. Recent debate around legalization of same sex marriage has highlighted for anti-same sex marriage advocates and policy makers a concern that allowing same sex couples to marry will lead to a decrease in opposite sex marriages. Our objective is to model state trends in opposite sex marriage rates by implementation of same sex marriages and other same sex unions. Methods and Findings Marriage data were obtained for all fifty states plus the District of Columbia from 1989 through 2009. As these marriage rates are non-stationary, a generalized error correction model was used to estimate long run and short run effects of same sex marriages and strong and weak same sex unions on rates of opposite sex marriage. We found that there were no significant long-run or short run effects of same sex marriages or of strong or weak same sex unions on rates of opposite sex marriage. Conclusion A deleterious effect on rates of opposite sex marriage has been argued to be a motivating factor for both the withholding and the elimination of existing rights of same sex couples to marry by policy makers–including presiding justices of current litigation over the rights of same sex couples to legally marry. Such claims do not appear credible in the face of the existing evidence, and we conclude that rates of opposite sex marriages are not affected by legalization of same sex civil unions or same sex marriages. PMID:23776536

  17. Tackling the diversity of sex determination

    PubMed Central

    Wedekind, Claus; Stelkens, Rike B.

    2010-01-01

    A workshop on ‘The evolution of sex determination systems’ was held at a remote place in the Swiss Alps from 17 to 20 June 2009. It brought together theoreticians and empiricists, the latter ranging from molecular geneticists to evolutionary ecologists, all trying to understand key aspects of sex determination. The topics discussed included the evolutionary origins of sex determination, the diversity of sex determination mechanisms in different taxa, and the transition from genotypic to environmental sex determination and vice versa. PMID:19692397

  18. Individual, Interpersonal, and Social-Structural Correlates of Involuntary Sex Exchange Among Female Sex Workers in Two Mexico–U.S. Border Cities

    PubMed Central

    Goldenberg, S.M.; Rangel, G.; Staines, H.; Vera, A.; Lozada, R.; Nguyen, L.; Silverman, J.G.; Strathdee, S.A.

    2013-01-01

    Objective To investigate individual, interpersonal, and social-structural factors associated with involuntary sex exchange among female sex workers (FSWs) along the Mexico–U.S. border. Methods In 2010–2011, 214 FSWs from Tijuana (n=106) and Ciudad Juarez (n=108) aged ≥18 who reported lifetime use of heroin, cocaine, crack, or methamphetamine, having a stable partner, and having sold/traded sex in the past month completed quantitative surveys and HIV/STI testing. Logistic regression was used to identify correlates of involuntary sex exchange among FSWs. Results Of 214 FSWs, 31 (14.5%) reported involuntary sex exchange. These women were younger at sex work entry (Adjusted odds ratio [AOR]: 0.84/1 year increase, 95% CI: 0.72–0.97) and were significantly more likely to service clients whom they perceived to be HIV/STI-infected (AOR: 12.41, 95% CI: 3.15–48.91). Additionally, they were more likely to have clients who used drugs (AOR: 7.88, 95% CI: 1.52–41.00), report poor working conditions (AOR: 3.27, 95% CI: 1.03–10.31), and report a history of rape (AOR: 4.46, 1.43–13.91).] Conclusions Involuntary sex exchange is disproportionate among FSWs who begin to exchange sex at a younger age, and these women experience elevated risk of violence and HIV/STIs related to their clients’ behaviors and their working conditions. These data suggest the critical need for evidence-based approaches to preventing sexual exploitation of women and girls and to reducing harm among current sex workers. Multi-level interventions for sex workers and their clients that target interpersonal and social-structural risks (e.g., measures to improve safety and reduce exploitation within the workplace) are needed. PMID:23614997

  19. Population consequences of environmental sex reversal.

    PubMed

    Cotton, Samuel; Wedekind, Claus

    2009-02-01

    When sex determination in a species is predominantly genetic but environmentally reversible, exposure to (anthropogenic) changes in the environment can lead to shifts in a population's sex ratio. Such scenarios may be common in many fishes and amphibians, yet their ramifications remain largely unexplored. We used a simple model to study the (short-term) population consequences of environmental sex reversal (ESR). We examined the effects on sex ratios, sex chromosome frequencies, and population growth and persistence after exposure to environmental forces with feminizing or masculinizing tendencies. When environmental feminization was strong, X chromosomes were driven to extinction. Analogously, extinction of normally male-linked genetic factors (e.g., Y chromosomes) was caused by continuous environmental masculinization. Although moderate feminization was beneficial for population growth in the absence of large viability effects, our results suggest that the consequences of ESR are generally negative in terms of population size and the persistence of sex chromosomes. Extreme sex ratios resulting from high rates of ESR also reduced effective population sizes considerably. This may limit any evolutionary response to the deleterious effects of ESR. Our findings suggest that ESR changes population growth and sex ratios in some counter-intuitive ways and can change the predominant factor in sex determination from genetic to fully environmental, often within only a few tens of generations. Populations that lose genetic sex determination may quickly go extinct if the environmental forces that cause sex reversal cease.

  20. Current status of sexing mammalian spermatozoa.

    PubMed

    Seidel, George E; Garner, Duane L

    2002-12-01

    Thousands of offspring have now been produced via artificial insemination with spermatozoa sexed by flow cytometry and cell sorting. We are unaware of any other practical approach to sexing spermatozoa that maintains fertility. Accuracy of sexing usually is 85-95% in most species, but somewhat lower with human spermatozoa. Spermatozoa are sexed in series, one at a time, at routine rates of about 3000 live spermatozoa of each sex per second for most species, and nearly twice that rate under optimal conditions for some species. Owing to various constraints and statistical considerations, there appears to be an upper theoretical limit to sexing spermatozoa of about 10,000 live spermatozoa of each sex per second with current methodology. About a quarter of the spermatozoa processed are sexed; the rest are discarded in the process or lost due to logistical constraints. Spermatozoa undergo some damage during sorting, although much less in terms of viability than with routine cryopreservation; fertility is lower with sexed than control spermatozoa. Offspring from sexed spermatozoa appear to have no more abnormalities than do controls, and both groups grow and thrive similarly. Despite high costs and complex procedures, sexing spermatozoa, usually followed by cryopreservation, is being used commercially for cattle and horse production in several countries, and is used to produce girls to avoid X-chromosome-linked genetic diseases.

  1. Bidirectional sex change in mushroom stony corals

    PubMed Central

    Loya, Yossi; Sakai, Kazuhiko

    2008-01-01

    Sex change occurs when an individual changes from one functional sex to another. The direction of sex change occurs mainly from male to female (protandry) or vice versa (protogyny), but sometimes may be bidirectional (repetitive). Here, for the first time in stony corals, we report on a protandrous sex change exhibited by two mushroom corals, Fungia repanda and Ctenactis echinata, with the latter also exhibiting bidirectional sex change. Compared with C. echinata, F. repanda exhibited relatively earlier sex change, significantly slower growth and higher mortality rates, in accordance with sex-allocation theory. Sex ratio in both the species was biased towards the first sex. The bidirectional sex change displayed by C. echinata greatly resembles that of dioecious plants that display labile sexuality in response to energetic and/or environmental constraints. We posit that, similar to these plants, in the studied corals, sex change increases their overall fitness, reinforcing the important role of reproductive plasticity in scleractinian corals in determining their evolutionary success. PMID:18611848

  2. HIV criminalisation and sex work in Australia.

    PubMed

    Jeffreys, Elena; Matthews, Kane; Thomas, Alina

    2010-05-01

    In 2008, Scarlet Alliance, the Australian Sex Workers Association, carried out a needs assessment among sex workers living with HIV in Australia. The research showed that HIV positive sex workers experience discrimination from within the community, are criminalised for sex work and subject to disclosure laws in some states and territories, and face stigma perpetrated by the media. Supported by legislation, they have an almost insurmountable lack of access to policy development due to disclosure and confidentiality issues, and have expressed ongoing frustration at the lack of leadership on the intersecting issues of HIV and sex work. A high profile prosecution of a sex worker living with HIV coincided with the duration of the needs assessment project. The research gave a voice to sex workers living with HIV and highlighted the levels of institutionalised marginalisation and stigmatisation they experience. Criminalisation of sex work, of people living with HIV, and of sex workers living with HIV is at the core of this discrimination and must be challenged. Scarlet Alliance advocates for the decriminalisation of sex work across all jurisdictions in Australia. This will deliver rights to sex workers living with HIV and create a more equitable and productive environment for HIV prevention and public health generally.

  3. Sex ratio in relation to fathers' occupations.

    PubMed Central

    Dickinson, H O; Parker, L

    1997-01-01

    OBJECTIVE: To investigate whether the sex ratio of children varies between fathers of different occupations. METHODS: The sex ratio (the ratio of the number of boys to the number of girls at birth) was calculated in relation to paternal occupation in the cohort of all 253,433 live births in Cumbria, north west England, from 1950-89. Exact binomial confidence intervals were used to estimate whether the sex ratio in each occupational category was significantly different from that for the rest of the cohort. RESULTS: There were fewer occupational categories with significantly different sex ratios at the 5% level than expected by chance alone, assuming the same binomial distribution of sexes at birth within each paternal occupation. CONCLUSIONS: Significant variation of the sex ratio with fathers' occupations was not found. There is some evidence that the sex ratio shows less variance than expected under a binomial model which assumes independence of the sex of each child; a possible explanation of this may be parental preference for limiting family size after children of both sexes have been born or some other factor which results in children within a family being more likely to be of both sexes rather than the same sex. PMID:9470894

  4. Sex determination and gender expression: Reproductive investment in snails.

    PubMed

    Koene, Joris M

    2017-02-01

    Sex determination is generally seen as an issue of importance for separate-sexed organisms; however, when considering other sexual systems, such as hermaphroditism, sex allocation is a less-binary form of sex determination. As illustrated here, with examples from molluscs, this different vantage point can offer important evolutionary insights. After all, males and females produce only one type of gamete, whereas hermaphrodites produce both. In addition, sperm and accessory gland products are donated bidirectionally. For reciprocal mating, this is obvious since sperm are exchanged within one mating interaction; but even unilaterally mating species end up mating in both sexual roles, albeit not simultaneously. With this in mind, I highlight two factors that play an important role in how reproductive investment is divided in snails: First, the individual's motivation to preferentially donate rather than receive sperm (or vice versa) leads to flexible behavioral performance, and thereby investment, of either sex. Second, due to the presence of both sexual roles within the same individual, partners are potentially able to influence investment in both sexual functions of their partner to their own benefit. The latter has already led to novel insights into how accessory gland products may evolve. Moreover, the current evidence points towards different ways in which allocation to reproduction can be changed in simultaneous hermaphrodites. These often differ from the separate-sexed situation, highlighting that comparison across different sexual systems may help identify commonalities and differences in physiological, and molecular mechanisms as well as evolutionary patterns. Mol. Reprod. Dev. 84: 132-143, 2017. © 2016 Wiley Periodicals, Inc.

  5. Additive lattice kirigami.

    PubMed

    Castle, Toen; Sussman, Daniel M; Tanis, Michael; Kamien, Randall D

    2016-09-01

    Kirigami uses bending, folding, cutting, and pasting to create complex three-dimensional (3D) structures from a flat sheet. In the case of lattice kirigami, this cutting and rejoining introduces defects into an underlying 2D lattice in the form of points of nonzero Gaussian curvature. A set of simple rules was previously used to generate a wide variety of stepped structures; we now pare back these rules to their minimum. This allows us to describe a set of techniques that unify a wide variety of cut-and-paste actions under the rubric of lattice kirigami, including adding new material and rejoining material across arbitrary cuts in the sheet. We also explore the use of more complex lattices and the different structures that consequently arise. Regardless of the choice of lattice, creating complex structures may require multiple overlapping kirigami cuts, where subsequent cuts are not performed on a locally flat lattice. Our additive kirigami method describes such cuts, providing a simple methodology and a set of techniques to build a huge variety of complex 3D shapes.

  6. Ceramics with Different Additives

    NASA Astrophysics Data System (ADS)

    Wang, Juanjuan; Feng, Lajun; Lei, Ali; Zhao, Kang; Yan, Aijun

    2014-09-01

    Li2CO3, MgCO3, BaCO3, and Bi2O3 dopants were introduced into CaCu3Ti4O12 (CCTO) ceramics in order to improve the dielectric properties. The CCTO ceramics were prepared by conventional solid-state reaction method. The phase structure, microstructure, and dielectric behavior were carefully investigated. The pure structure without any impurity phases can be confirmed by the x-ray diffraction patterns. Scanning Electron Microscopy (SEM) analysis illuminated that the grains of Ca0.90Li0.20Cu3Ti4O12 ceramics were greater than that of pure CCTO. It was important for the properties of the CCTO ceramics to study the additives in complex impedance spectroscopy. It was found that the Ca0.90Li0.20Cu3Ti4O12 ceramics had the higher permittivity (>45000), the lower dielectric loss (<0.025) than those of CCTO at 1 kHz at room temperature and good temperature stability from -30 to 75 °C.

  7. Additive lattice kirigami

    PubMed Central

    Castle, Toen; Sussman, Daniel M.; Tanis, Michael; Kamien, Randall D.

    2016-01-01

    Kirigami uses bending, folding, cutting, and pasting to create complex three-dimensional (3D) structures from a flat sheet. In the case of lattice kirigami, this cutting and rejoining introduces defects into an underlying 2D lattice in the form of points of nonzero Gaussian curvature. A set of simple rules was previously used to generate a wide variety of stepped structures; we now pare back these rules to their minimum. This allows us to describe a set of techniques that unify a wide variety of cut-and-paste actions under the rubric of lattice kirigami, including adding new material and rejoining material across arbitrary cuts in the sheet. We also explore the use of more complex lattices and the different structures that consequently arise. Regardless of the choice of lattice, creating complex structures may require multiple overlapping kirigami cuts, where subsequent cuts are not performed on a locally flat lattice. Our additive kirigami method describes such cuts, providing a simple methodology and a set of techniques to build a huge variety of complex 3D shapes. PMID:27679822

  8. Conservation of sex chromosomes in lacertid lizards.

    PubMed

    Rovatsos, Michail; Vukić, Jasna; Altmanová, Marie; Johnson Pokorná, Martina; Moravec, Jiří; Kratochvíl, Lukáš

    2016-07-01

    Sex chromosomes are believed to be stable in endotherms, but young and evolutionary unstable in most ectothermic vertebrates. Within lacertids, the widely radiated lizard group, sex chromosomes have been reported to vary in morphology and heterochromatinization, which may suggest turnovers during the evolution of the group. We compared the partial gene content of the Z-specific part of sex chromosomes across major lineages of lacertids and discovered a strong evolutionary stability of sex chromosomes. We can conclude that the common ancestor of lacertids, living around 70 million years ago (Mya), already had the same highly differentiated sex chromosomes. Molecular data demonstrating an evolutionary conservation of sex chromosomes have also been documented for iguanas and caenophidian snakes. It seems that differences in the evolutionary conservation of sex chromosomes in vertebrates do not reflect the distinction between endotherms and ectotherms, but rather between amniotes and anamniotes, or generally, the differences in the life history of particular lineages.

  9. [Mobile genetic elements in plant sex evolution].

    PubMed

    Gerashchenkov, G A; Rozhnova, N A

    2010-11-01

    The most significant theories of the appearance and maintenance of sex are presented. However, in the overwhelming majority of existing theories, the problem of sex, which is the central problem of evolutionary biology, is considered primarily through the prism of reproductive features of living organisms, whereas the issue of molecular driving forces of sexual reproduction id restricted to the possible role of mobile genetic elements (MGEs) in the appearance of sexual reproduction. The structural and functional significance of MGEs in the genomic organization of plants is illustrated. It is shown that MGEs could act as important molecular drivers of sex evolution in plants. The involvement of MGEs in the formation of sex chromosomes and possible participation in seeds-without-sex reproduction (apomixis) is discussed. Thus, the hypothesis on the active MGE participation in sex evolution is in good agreement with the modern views on pathways and directions of sex evolution in plants.

  10. Sex differences in the human visual system.

    PubMed

    Vanston, John E; Strother, Lars

    2017-01-02

    This Mini-Review summarizes a wide range of sex differences in the human visual system, with a primary focus on sex differences in visual perception and its neural basis. We highlight sex differences in both basic and high-level visual processing, with evidence from behavioral, neurophysiological, and neuroimaging studies. We argue that sex differences in human visual processing, no matter how small or subtle, support the view that females and males truly see the world differently. We acknowledge some of the controversy regarding sex differences in human vision and propose that such controversy should be interpreted as a source of motivation for continued efforts to assess the validity and reliability of published sex differences and for continued research on sex differences in human vision and the nervous system in general. © 2016 Wiley Periodicals, Inc.

  11. Correlates of exchanging sex for drugs or money among women who use crack cocaine.

    PubMed

    Edwards, Jessica M; Halpern, Carolyn T; Wechsberg, Wendee M

    2006-10-01

    This study examined the correlates of trading sex for drugs or money among women who use crack cocaine. Using baseline data (n = 669) from a woman-focused HIV intervention study among African American women who use crack cocaine, we conducted logistic regression analysis to examine the odds of trading sex associated with distal and proximal factors. The results indicate that heavier crack use, homelessness, and unemployment are associated with trading sex. In addition, childhood abuse is associated with trading sex and this relationship is, in part, mediated by psychological distress. This suggests that distal factors may underlie the relationship between current variables and sex trading. These findings underscore the importance for public health interventions to address both distal and proximal factors that contribute to and/or co-occur with women's drug use which, in turn, may affect their HIV risk and overall well-being.

  12. Foster care history and HIV infection among drug-using African American female sex workers.

    PubMed

    Surratt, Hilary L; Kurtz, Steven P

    2012-05-01

    Foster care has been associated with increased HIV risk behaviors among youth, yet long-term association with HIV infection has not been examined. This study explored the associations between foster placement, victimization, mental health, onset of sex work and HIV infection among highly vulnerable female sex workers. 562 drug-involved African American women were enrolled into an intervention study to increase health services utilization and reduce HIV risk. Seventeen percent reported a history of foster placement. Foster history was associated with significantly lower educational attainment, higher victimization, and more severe mental health problems. Women with foster histories reported significantly earlier entry into paid sex work, with some 62% active in the sex trade before age 18. Multivariate analyses found that foster care was independently associated with HIV seropositivity, and that early sex work partially mediated this association. The potential long-term health vulnerabilities associated with foster placement are understudied and warrant additional research.

  13. Depressive symptoms among MSM who engage in bareback sex: does mood matter?

    PubMed

    Houston, E; Sandfort, T; Dolezal, C; Carballo-Diéguez, A

    2012-11-01

    Much research has examined the relationship between depressive symptoms and unprotected sex among men who have sex with men (MSM), but little is known about how depression is related to the sexual behavior of men who intentionally engage in unprotected anal intercourse, or bareback sex. In this study, we explored the extent to which depressive symptoms were associated with rates of unprotected sex among barebackers, and whether this relationship was dependent upon HIV serostatus. Using a sample of 120 MSM who engage in intentional condomless sex, we found that for HIV-negative participants, depressive symptoms were associated with the overall frequency of unprotected anal intercourse as well as unprotected anal intercourse with a serodiscordant partner. For HIV-positive participants, depressive symptoms were not associated unprotected intercourse. Additional research is needed to better understand depression among men who bareback and how interventions could be designed to address depression and reduce sexual risk behaviors.

  14. Committee Opinion No. 574: Marriage equality for same-sex couples.

    PubMed

    2013-09-01

    Same-sex couples encounter barriers to health care that include concerns about confidentiality and disclosure, stigma and discriminatory attitudes and treatment, limited access to health care and health insurance, and often a limited understanding of their health risks. Same-sex couples and their families are adversely affected by the lack of legal recognition of their relationships, a problem with major implications for the health of same-sex couples and their families. Tangible harm has come from the lack of financial and health care protections granted to legal spouses, and children are harmed by the lack of protections afforded to families in which partners are married. However, the recent Supreme Court ruling, The United States v Windsor, which afforded equal treatment for legally married same-sex couples will provide many important health and financial benefits. Evidence suggests that marriage confers health benefits to individuals and families, yet a sizable proportion of individuals do not experience these health benefits because of their sexual orientation. Additional data suggest that same-sex couples who live in states with bans on same-sex unions experience adverse health outcomes. Civil marriage is currently available to same-sex couples in only thirteen states and the District of Columbia and honored by one state. The American College of Obstetricians and Gynecologists endorses marriage equality for same-sex couples and equal treatment for these couples and their families and applauds the Supreme Court's decision as an important step in improving access to benefits received by legally married same-sex couples. However, additional efforts are necessary to ensure that same-sex couples in every state can receive these same benefits.

  15. Genomic Instability of the Sex-Determining Locus in Atlantic Salmon (Salmo salar).

    PubMed

    Lubieniecki, Krzysztof P; Lin, Song; Cabana, Emily I; Li, Jieying; Lai, Yvonne Y Y; Davidson, William S

    2015-09-22

    Atlantic salmon and rainbow trout, like other members of the subfamily Salmoninae, are gonochoristic with male heterogamety. The finding that sex-linked genetic markers varied between species suggested that the sex-determining gene differs among salmonid species, or that there is one sex-determining gene that has the capacity to move around the genome. The discovery of sdY, the sex-determining gene in rainbow trout, and its presence in many male salmonids gave support to the latter. Additional evidence for a salmonid-specific, sex-determining jumping gene came from the mapping of the sex-determining locus to three different chromosomes in Tasmanian male Atlantic salmon lineages. To characterize the sex-determining region, we isolated three sdY containing BACs from an Atlantic salmon male library. Sequencing of these BACs yielded two contigs, one of which contained the sdY gene. Sequence analysis of the borders of male-specific and female/male common regions revealed highly repetitive sequences associated with mobile elements, which may allow an sdY cassette to jump around the genome. FISH analysis using a BAC or a plasmid containing the sdY gene showed that the sdY gene did indeed localize to the chromosomes where SEX had been mapped in different Tasmanian Atlantic salmon families. Moreover, the plasmid sdY gene probe hybridized primarily to one of the sex chromosomes as would be expected of a male-specific gene. Our results suggest that a common salmonid sex-determining gene (sdY) can move between three specific loci on chromosomes 2, 3, and 6, giving the impression that there are multiple SEX loci both within and between salmonid species.

  16. Loss of sex chromosomes in the hematopoietic disorders: Questions, concerns and data interpretation

    SciTech Connect

    Slovak, M.L.

    1994-09-01

    The significance of sex chromosome aberrations in the hematopoietic disorders has not yet been defined. Interpretive problems stem from (1) the loss of a sex chromosome associated with aging, (2) sex chromosome loss as the sole aberration in leukemia is rare, (3) random -(X or Y) is observed frequently in bone marrow samples, and (4) constitutional sex chromosome anomalies must be ruled out in cancer and follow-up may not be possible. The COH database identified 41 patients (pts) with sex chromosome loss. Loss of a sex chromosome was common in myeloid disorders (21/41). In t(8;21) leukemia (n=10), -(X or Y) was a common secondary karyotypic change. Additionally, -Y was associated with clonal evolution in 2 Ph + CML pts. In 2 elderly pts with myeloid disorders, -(X or Y) was observed in complex karyotypes with dmins; however, in the lymphoproliferative disorders -(X or Y) was noted in elderly pts without apparent pathogenetic significance. Three pts had constitutional sex chromosome aberrations: CML in 45,X; ALL in 47, XXY; and RAEB-IT in mos45,X/46,XX. In the mos45,X/46,XX pt, the leukemic clone was associated with the 45,X line without other karyotypic changes. Non-clonal aberrations were observed in 11 cases; in 3 cases these non-clonal losses were observed in serial samples. In a sex-mismatched BMT case, -(X or Y) in 4 cells was one of the first pathogenetic signs of leukemia relapse. These data suggest (1) interpretation of sex chromosome loss in leukemia must be made with caution and after a baseline sample, (2) non-clonal aberrations should be recorded, and (3) -(X or Y) appears to have pathogenetic significance in the myeloid disorders. Multi-institutional studies are needed to define (1) the incidence of leukemia in pts with constitutional sex chromosome anomalies and (2) the incidence and significance of sex chromosome aberrations as the primary (sole) cytogenetic aberration in leukemia.

  17. The evolution of sex is favoured during adaptation to new environments.

    PubMed

    Becks, Lutz; Agrawal, Aneil F

    2012-01-01

    Both theory and experiments have demonstrated that sex can facilitate adaptation, potentially yielding a group-level advantage to sex. However, it is unclear whether this process can help solve the more difficult problem of the maintenance of sex within populations. Using experimental populations of the facultatively sexual rotifer Brachionus calyciflorus, we show that rates of sex evolve to higher levels during adaptation but then decline as fitness plateaus. To assess the fitness consequences of genetic mixing, we directly compare the fitnesses of sexually and asexually derived genotypes that naturally occur in our experimental populations. Sexually derived genotypes are more fit than asexually derived genotypes when adaptive pressures are strong, but this pattern reverses as the pace of adaptation slows, matching the pattern of evolutionary change in the rate of sex. These fitness assays test the net effect of sex but cannot be used to disentangle whether selection on sex arises because highly sexual lineages become associated with different allele combinations or with different allele frequencies than less sexual lineages (i.e., "short-" or "long-term" effects, respectively). We infer which of these mechanisms provides an advantage to sex by performing additional manipulations to obtain fitness distributions of sexual and asexual progeny arrays from unbiased parents (rather than from naturally occurring, and thereby evolutionarily biased, parents). We find evidence that sex breaks down adaptive gene combinations, resulting in lower average fitness of sexual progeny (i.e., a short-term disadvantage to sex). As predicted by theory, the advantage to sex arises because sexually derived progeny are more variable in fitness, allowing for faster adaptation. This "long-term advantage" builds over multiple generations, eventually resulting in higher fitness of sexual types.

  18. Sex and the development of Alzheimer's disease.

    PubMed

    Pike, Christian J

    2017-01-02

    Men and women exhibit differences in the development and progression of Alzheimer's disease (AD). The factors underlying the sex differences in AD are not well understood. This Review emphasizes the contributions of sex steroid hormones to the relationship between sex and AD. In women, events that decrease lifetime exposure to estrogens are generally associated with increased AD risk, whereas estrogen-based hormone therapy administered near the time of menopause may reduce AD risk. In men, estrogens do not exhibit age-related reduction and are not significantly associated with AD risk. Rather, normal age-related depletions of testosterone in plasma and brain predict enhanced vulnerability to AD. Both estrogens and androgens exert numerous protective actions in the adult brain that increase neural functioning and resilience as well as specifically attenuating multiple aspects of AD-related neuropathology. Aging diminishes the activational effects of sex hormones in sex-specific manners, which is hypothesized to contribute to the relationship between aging and AD. Sex steroid hormones may also drive sex differences in AD through their organizational effects during developmental sexual differentiation of the brain. Specifically, sex hormone actions during early development may confer inherent vulnerability of the female brain to development of AD in advanced age. The combined effects of organizational and activational effects of sex steroids yield distinct sex differences in AD pathogenesis, a significant variable that must be more rigorously considered in future research. © 2016 Wiley Periodicals, Inc.

  19. Sex differences in the vomeronasal system.

    PubMed

    Guillamón, A; Segovia, S

    1997-01-01

    In the early eighties we found sex differences in the vomeronasal organ (VNO) and hypothesized that the vomeronasal system (VNS), a complex neural network involved in the control of reproductive behavior, might be sexually dimorphic. At that time sex differences had already been described for some structures that receive VNO input, such as the medial amygdala, the medial preoptic area, the ventromedial hypothalamic nucleus, and the ventral region of the premammillary nucleus. Since then, we have shown sex differences in the accessory olfactory bulb (AOB), the bed nucleus of the accessory olfactory tract (BAOT), and the bed nucleus of the stria terminalis (BST). When new VNS connections were found, all of them ended in nuclei that present sex differences. In general, sex differences in the olfactory system show two morphological patterns: one in which males present greater morphological measures than females, and just the opposite. To explain the morphometric measures of males in the latter, it has been hypothesized that androgens serve as inhibitors. Our work on the involvement of the GABA(A) receptor in the development of AOB and maternal behavior sex differences also suggests that neonatal changes in neuronal membrane permeability to the ion Cl- differences. This might be the first animal model to help us to understand the situation in which human genetic and gonadal sex do not agree with brain and behavioral sex. Finally, we stress that sex differences in the VNS constitute a neurofunctional model for understanding sex differences in reproductive behaviors.

  20. Technology, normalisation and male sex work.

    PubMed

    MacPhail, Catherine; Scott, John; Minichiello, Victor

    2015-01-01

    Technological change, particularly the growth of the Internet and smart phones, has increased the visibility of male escorts, expanded their client base and diversified the range of venues in which male sex work can take place. Specifically, the Internet has relocated some forms of male sex work away from the street and thereby increased market reach, visibility and access and the scope of sex work advertising. Using the online profiles of 257 male sex workers drawn from six of the largest websites advertising male sexual services in Australia, the role of the Internet in facilitating the normalisation of male sex work is discussed. Specifically we examine how engagement with the sex industry has been reconstituted in term of better informed consumer-seller decisions for both clients and sex workers. Rather than being seen as a 'deviant' activity, understood in terms of pathology or criminal activity, male sex work is increasingly presented as an everyday commodity in the market place. In this context, the management of risks associated with sex work has shifted from formalised social control to more informal practices conducted among online communities of clients and sex workers. We discuss the implications for health, legal and welfare responses within an empowerment paradigm.

  1. Perils and pitfalls of reporting sex differences

    PubMed Central

    Maney, Donna L.

    2016-01-01

    The idea of sex differences in the brain both fascinates and inflames the public. As a result, the communication and public discussion of new findings is particularly vulnerable to logical leaps and pseudoscience. A new US National Institutes of Health policy to consider both sexes in almost all preclinical research will increase the number of reported sex differences and thus the risk that research in this important area will be misinterpreted and misrepresented. In this article, I consider ways in which we might reduce that risk, for example, by (i) employing statistical tests that reveal the extent to which sex explains variation, rather than whether or not the sexes ‘differ’, (ii) properly characterizing the frequency distributions of scores or dependent measures, which nearly always overlap, and (iii) avoiding speculative functional or evolutionary explanations for sex-based variation, which usually invoke logical fallacies and perpetuate sex stereotypes. Ultimately, the factor of sex should be viewed as an imperfect, temporary proxy for yet-unknown factors, such as hormones or sex-linked genes, that explain variation better than sex. As scientists, we should be interested in discovering and understanding the true sources of variation, which will be more informative in the development of clinical treatments. PMID:26833839

  2. Sexing pinnipeds with ZFX and ZFY loci.

    PubMed

    Curtis, Caitlin; Stewart, Brent S; Karl, Stephen A

    2007-01-01

    We developed and tested a protocol for determining the sex of individual pinnipeds using the sex-chromosome-specific genes ZFX and ZFY. We screened a total of 368 seals (168 crabeater, Lobodon carcinophaga; 159 Weddell, Leptonychotes weddellii; and 41 Ross, Ommatophoca rossii) of known or unknown sex and compared the molecular sex to the sex assigned at the time of biopsy sample collection in the Ross and Amundsen seas, Antarctica. We also screened 6 captive northern elephant seals (Mirounga angustirostris) and 2 captive California sea lions (Zalophus californianus) of known sex. The assigned sex and genetic sex agreed for virtually all seals. Indeed, discrepancies ranged from 0.0% to 6.7% among species. It is not clear, however, if the few mis-assignments of sex occurred in situ or in the laboratory. The assigned morphological and molecular sex might both be correct with the discrepancies owing perhaps to developmental effects of environmental pollution. A subset of individuals sequenced at both loci revealed no intraspecific sequence variation. There was, however, sequence variation among species at both loci, which allowed them to be uniquely identified with as few as 2 and as many as 31 nucleotides.

  3. Searching for the Advantages of Virus Sex

    NASA Astrophysics Data System (ADS)

    Turner, Paul E.

    2003-02-01

    Sex (genetic exchange) is a nearly universal phenomenon in biological populations. But this is surprising given the costs associated with sex. For example, sex tends to break apart co-adapted genes, and sex causes a female to inefficiently contribute only half the genes to her offspring. Why then did sex evolve? One famous model poses that sex evolved to combat Muller's ratchet, the mutational load that accrues when harmful mutations drift to high frequencies in populations of small size. In contrast, the Fisher-Muller Hypothesis predicts that sex evolved to promote genetic variation that speeds adaptation in novel environments. Sexual mechanisms occur in viruses, which feature high rates of deleterious mutation and frequent exposure to novel or changing environments. Thus, confirmation of one or both hypotheses would shed light on the selective advantages of virus sex. Experimental evolution has been used to test these classic models in the RNA bacteriophage φ6, a virus that experiences sex via reassortment of its chromosomal segments. Empirical data suggest that sex might have originated in φ6 to assist in purging deleterious mutations from the genome. However, results do not support the idea that sex evolved because it provides beneficial variation in novel environments. Rather, experiments show that too much sex can be bad for φ6 promiscuity allows selfish viruses to evolve and spread their inferior genes to subsequent generations. Here I discuss various explanations for the evolution of segmentation in RNA viruses, and the added cost of sex when large numbers of viruses co-infect the same cell.

  4. Sex determination and differentiation in Aurelia sp.1: the absence of temperature dependence

    NASA Astrophysics Data System (ADS)

    Liu, Chunsheng; Gu, Zhifeng; Xing, Mengxin; Sun, Yun; Chen, Siqing; Chen, Zhaoting

    2017-03-01

    Cnidarians, being regarded as `basal' metazoan animals, are considered to have relatively high plasticity in terms of sex reversal. In this study we used an experimental approach to demonstrate sexual differentiation and plasticity in benthic polyps and pelagic medusae of Aurelia sp.1 maintained at different temperatures. Results indicated that in Aurelia sp.1, sex differentiation has been determined at the polyp stage and that all medusae originating from a given polyp are, phenotypically, of the same sex. In addition, the sex of polyps budding from the same clone (either male or female) at different temperatures appears to be the same as that of the parent. The sex of medusae that had originated from a known-sex polyp was observed to remain the same as that of the parent, irrespective of differences in strobilation or rearing temperatures. These results indicate that the mechanism of sex determination of Aurelia sp.1. is not influenced by prevailing temperature regimes. A comparison of variability in terms of sexual plasticity of Aurelia sp.1 with that of Hydrozoa and Anthozoa suggests that species characterized by a free-swimming medusa life stage have a high dispersal potential, which probably results in a lower rate of sex reversal.

  5. Why are sex and gender important to basic physiology and translational and individualized medicine?

    PubMed Central

    2014-01-01

    Sex refers to biological differences between men and women. Although sex is a fundamental aspect of human physiology that splits the population in two approximately equal halves, this essential biological variable is rarely considered in the design of basic physiological studies, in translating findings from basic science to clinical research, or in developing personalized medical strategies. Contrary to sex, gender refers to social and cultural factors related to being a man or a woman in a particular historical and cultural context. Unfortunately, gender is often used incorrectly by scientists and clinical investigators as synonymous with sex. This article clarifies the definition of sex and gender and reviews evidence showing how sex and gender interact with each other to influence etiology, presentation of disease, and treatment outcomes. In addition, strategies to improve the inclusion of female and male human beings in preclinical and clinical studies will be presented, and the importance of embedding concepts of sex and gender into postgraduate and medical curricula will be discussed. Also, provided is a list of resources for educators. In the history of medical concepts, physiologists have provided pivotal contributions to understanding health and disease processes. In the future, physiologists should provide the evidence for advancing personalized medicine and for reducing sex and gender disparities in health care. PMID:24414073

  6. Men's Intentions to Have Sex With a New Partner: Sexual and Emotional Responding, Alcohol, and Condoms.

    PubMed

    Gilmore, Amanda K; George, William H; Jacques-Tiura, Angela J; Granato, Hollie F; Davis, Kelly Cue; Norris, Jeanette; Heiman, Julia R

    2016-01-01

    Findings regarding the relation between alcohol and intentions to have sex have been mixed, and little research has examined the role of condom availability on intentions to have sex. Sexual and emotional responding may influence subsequent sexual decisions. Thus, a better understanding of sexual and emotional responding combined with situational factors such as condom presence could help explain the discrepancies in findings regarding alcohol's effect on intentions to have sex. The effects of alcohol and condom presence on men's intentions to have sex were examined using an experimental paradigm involving an alcohol administration study and a second-person eroticized scenario. The effects of sexual and emotional responding were also examined in relation to intentions to have sex. It was found that alcohol increased positive mood, which was associated with higher intentions to have sex. In addition, condom presence was directly associated with higher intentions to have sex. More sexual desire was related to increased likelihood of sexual intentions. These findings increase understanding of mechanisms underlying the relation between alcohol and intentions to have sex.

  7. Comparative Transcriptome Analysis Reveals Sex-Biased Gene Expression in Juvenile Chinese Mitten Crab Eriocheir sinensis

    PubMed Central

    Liu, Yuan; Hui, Min; Cui, Zhaoxia; Luo, Danli; Song, Chengwen; Li, Yingdong; Liu, Lei

    2015-01-01

    Sex-biased genes are considered to account for most of phenotypic differences between males and females. In order to explore the sex-biased gene expression in crab, we performed the whole-body transcriptome analysis in male and female juveniles of the Chinese mitten crab Eriocheir sinensis using next-generation sequencing technology. Of the 23,349 annotated unigenes, 148 were identified as sex-related genes. A total of 29 candidate genes involved in primary sex determination pathways were detected, indicating the sex determination cascade of the mitten crab might be more complex than previously supposed. Differential expression analysis showed 448 differentially expressed genes (DEGs) between the two transcriptomes. Most of DEGs were involved in processes such as metabolism and immunity, and not associated with obvious sexual function. The pathway predominantly enriched for DEGs were related to lysosome, which might reflect the differences in metabolism between males and females. Of the immune DGEs, 18 up-regulated genes in females were humoral immune factors, and eight up-regulated genes in males were pattern recognition receptors, suggesting sex differences of immune defense might exist in the mitten crab. In addition, two reproduction-related genes, vitellogenin and insulin-like androgenic gland factor, were identified to express in both sexes but with significantly higher level in males. Our research provides the first whole-body RNA sequencing of sex-specific transcriptomes for juvenile E. sinensis and will facilitate further studies on molecular mechanisms of crab sexual dimorphism. PMID:26193085

  8. What affects fertility of sexed bull semen more, low sperm dosage or the sorting process?

    PubMed

    Frijters, A C J; Mullaart, E; Roelofs, R M G; van Hoorne, R P; Moreno, J F; Moreno, O; Merton, J S

    2009-01-01

    Until now it has been unclear to what extent the reduced fertility with sexed semen in the dairy industry is caused by too few sperm per AI dose, or by the effect of flow cytometric sorting, which is the established procedure for sexing semen. Therefore, we evaluated the effects of low sperm numbers per dose with and without sorting on non-return rates after 56 days (NRR 56); in addition, we evaluated the effects of bulls, in order to further optimize use of sexed semen. Based on results of using sexed semen from seven Holstein bulls, an overall numerical decline of 13.6% in NRR 56 was observed (P<0.05). About two-thirds of this decline (8.6%) was due to the low dose (P<0.05), and a third (5.0%) due to the process of sorting (P<0.05). The effect of low dosage and sorting differed among bulls. We observed a sex ratio of 91.6% females for sexed semen from the first 131 calves born. Currently the best way to increase fertility of sexed semen is by closely monitoring fertility so that the highest fertility bulls are used, and by improving farm animal management. However, to make substantial progress, more in depth studies are needed on the sexing technology, especially on aspects such as sorting procedures and sperm dosage.

  9. Meditation Awareness Training for the Treatment of Sex Addiction: A Case Study.

    PubMed

    Van Gordon, William; Shonin, Edo; Griffiths, Mark D

    2016-06-01

    Background Sex addiction is a disorder that can have serious adverse functional consequences. Treatment effectiveness research for sex addiction is currently underdeveloped, and interventions are generally based on the guidelines for treating other behavioral (as well as chemical) addictions. Consequently, there is a need to clinically evaluate tailored treatments that target the specific symptoms of sex addiction. It has been proposed that second-generation mindfulness-based interventions (SG-MBIs) may be an appropriate treatment for sex addiction because in addition to helping individuals increase perceptual distance from craving for desired objects and experiences, some SG-MBIs specifically contain meditations intended to undermine attachment to sex and/or the human body. The current study conducts the first clinical investigation into the utility of mindfulness for treating sex addiction. Case presentation An in-depth clinical case study was conducted involving an adult male suffering from sex addiction that underwent treatment utilizing an SG-MBI known as Meditation Awareness Training (MAT). Following completion of MAT, the participant demonstrated clinically significant improvements in addictive sexual behavior, as well as reductions in depression and psychological distress. The MAT intervention also led to improvements in sleep quality, job satisfaction, and non-attachment to self and experiences. Salutary outcomes were maintained at 6-month follow-up. Discussion and conclusion The current study extends the literature exploring the applications of mindfulness for treating behavioral addiction, and findings indicate that further clinical investigation into the role of mindfulness for treating sex addiction is warranted.

  10. Systematic Analysis of Adverse Event Reports for Sex Differences in Adverse Drug Events

    PubMed Central

    Yu, Yue; Chen, Jun; Li, Dingcheng; Wang, Liwei; Wang, Wei; Liu, Hongfang

    2016-01-01

    Increasing evidence has shown that sex differences exist in Adverse Drug Events (ADEs). Identifying those sex differences in ADEs could reduce the experience of ADEs for patients and could be conducive to the development of personalized medicine. In this study, we analyzed a normalized US Food and Drug Administration Adverse Event Reporting System (FAERS). Chi-squared test was conducted to discover which treatment regimens or drugs had sex differences in adverse events. Moreover, reporting odds ratio (ROR) and P value were calculated to quantify the signals of sex differences for specific drug-event combinations. Logistic regression was applied to remove the confounding effect from the baseline sex difference of the events. We detected among 668 drugs of the most frequent 20 treatment regimens in the United States, 307 drugs have sex differences in ADEs. In addition, we identified 736 unique drug-event combinations with significant sex differences. After removing the confounding effect from the baseline sex difference of the events, there are 266 combinations remained. Drug labels or previous studies verified some of them while others warrant further investigation. PMID:27102014

  11. Comparative Transcriptome Analysis Reveals Sex-Biased Gene Expression in Juvenile Chinese Mitten Crab Eriocheir sinensis.

    PubMed

    Liu, Yuan; Hui, Min; Cui, Zhaoxia; Luo, Danli; Song, Chengwen; Li, Yingdong; Liu, Lei

    2015-01-01

    Sex-biased genes are considered to account for most of phenotypic differences between males and females. In order to explore the sex-biased gene expression in crab, we performed the whole-body transcriptome analysis in male and female juveniles of the Chinese mitten crab Eriocheir sinensis using next-generation sequencing technology. Of the 23,349 annotated unigenes, 148 were identified as sex-related genes. A total of 29 candidate genes involved in primary sex determination pathways were detected, indicating the sex determination cascade of the mitten crab might be more complex than previously supposed. Differential expression analysis showed 448 differentially expressed genes (DEGs) between the two transcriptomes. Most of DEGs were involved in processes such as metabolism and immunity, and not associated with obvious sexual function. The pathway predominantly enriched for DEGs were related to lysosome, which might reflect the differences in metabolism between males and females. Of the immune DGEs, 18 up-regulated genes in females were humoral immune factors, and eight up-regulated genes in males were pattern recognition receptors, suggesting sex differences of immune defense might exist in the mitten crab. In addition, two reproduction-related genes, vitellogenin and insulin-like androgenic gland factor, were identified to express in both sexes but with significantly higher level in males. Our research provides the first whole-body RNA sequencing of sex-specific transcriptomes for juvenile E. sinensis and will facilitate further studies on molecular mechanisms of crab sexual dimorphism.

  12. Declining Segregation of Same-Sex Partners: Evidence from Census 2000 and 2010

    PubMed Central

    2013-01-01

    Despite recent media and scholarly attention describing the “disappearance” of traditionally gay neighborhoods, urban scholars have yet to quantify the segregation of same-sex partners and determine whether declining segregation from different-sex partners is a wide-spread trend. Focusing on the 100 most populous places in the United States, I use data from the 2000 and 2010 Decennial Census to examine the segregation of same-sex partners over time and its place-level correlates. I estimate linear regression models to examine the role of four place characteristics in particular: average levels of education, aggregate trends in the family life cycle of same-sex partners, violence and social hostility motivated by sexual orientation bias, and representation of same-sex partners in the overall population. On average, same-sex partners were less segregated from different-sex partners in 2010 than in 2000, and the vast majority of same-sex partners lived in environments of declining segregation. Segregation was lower and declined more rapidly in places that had a greater percentage of graduate degree holders. In addition, segregation of female partners was lower in places that had a greater share of female partner households with children. These findings suggest that sexual orientation should be considered alongside economic status, race, and ethnicity as an important factor that contributes to neighborhood differentiation and urban spatial inequality. PMID:24187412

  13. Why are sex and gender important to basic physiology and translational and individualized medicine?

    PubMed

    Miller, Virginia M

    2014-03-01

    Sex refers to biological differences between men and women. Although sex is a fundamental aspect of human physiology that splits the population in two approximately equal halves, this essential biological variable is rarely considered in the design of basic physiological studies, in translating findings from basic science to clinical research, or in developing personalized medical strategies. Contrary to sex, gender refers to social and cultural factors related to being a man or a woman in a particular historical and cultural context. Unfortunately, gender is often used incorrectly by scientists and clinical investigators as synonymous with sex. This article clarifies the definition of sex and gender and reviews evidence showing how sex and gender interact with each other to influence etiology, presentation of disease, and treatment outcomes. In addition, strategies to improve the inclusion of female and male human beings in preclinical and clinical studies will be presented, and the importance of embedding concepts of sex and gender into postgraduate and medical curricula will be discussed. Also, provided is a list of resources for educators. In the history of medical concepts, physiologists have provided pivotal contributions to understanding health and disease processes. In the future, physiologists should provide the evidence for advancing personalized medicine and for reducing sex and gender disparities in health care.

  14. Inbreeding removes sex differences in lifespan in a population of Drosophila melanogaster.

    PubMed

    Carazo, Pau; Green, Jared; Sepil, Irem; Pizzari, Tommaso; Wigby, Stuart

    2016-06-01

    Sex differences in ageing rates and lifespan are common in nature, and an enduring puzzle for evolutionary biology. One possibility is that sex-specific mortality rates may result from recessive deleterious alleles in 'unguarded' heterogametic X or Z sex chromosomes (the unguarded X hypothesis). Empirical evidence for this is, however, limited. Here, we test a fundamental prediction of the unguarded X hypothesis in Drosophila melanogaster, namely that inbreeding shortens lifespan more in females (the homogametic sex in Drosophila) than in males. To test for additional sex-specific social effects, we studied the lifespan of males and females kept in isolation, in related same-sex groups, and in unrelated same-sex groups. As expected, outbred females outlived outbred males and inbreeding shortened lifespan. However, inbreeding-mediated reductions in lifespan were stronger for females, such that lifespan was similar in inbred females and males. We also show that the social environment, independent of inbreeding, affected male, but not female lifespan. In conjunction with recent studies, the present results suggest that asymmetric inheritance mechanisms may play an important role in the evolution of sex-specific lifespan and that social effects must be considered explicitly when studying these fundamental patterns.

  15. Inbreeding removes sex differences in lifespan in a population of Drosophila melanogaster

    PubMed Central

    Green, Jared; Sepil, Irem; Pizzari, Tommaso; Wigby, Stuart

    2016-01-01

    Sex differences in ageing rates and lifespan are common in nature, and an enduring puzzle for evolutionary biology. One possibility is that sex-specific mortality rates may result from recessive deleterious alleles in ‘unguarded’ heterogametic X or Z sex chromosomes (the unguarded X hypothesis). Empirical evidence for this is, however, limited. Here, we test a fundamental prediction of the unguarded X hypothesis in Drosophila melanogaster, namely that inbreeding shortens lifespan more in females (the homogametic sex in Drosophila) than in males. To test for additional sex-specific social effects, we studied the lifespan of males and females kept in isolation, in related same-sex groups, and in unrelated same-sex groups. As expected, outbred females outlived outbred males and inbreeding shortened lifespan. However, inbreeding-mediated reductions in lifespan were stronger for females, such that lifespan was similar in inbred females and males. We also show that the social environment, independent of inbreeding, affected male, but not female lifespan. In conjunction with recent studies, the present results suggest that asymmetric inheritance mechanisms may play an important role in the evolution of sex-specific lifespan and that social effects must be considered explicitly when studying these fundamental patterns. PMID:27354712

  16. Meditation Awareness Training for the Treatment of Sex Addiction: A Case Study

    PubMed Central

    Van Gordon, William; Shonin, Edo; Griffiths, Mark D.

    2016-01-01

    Background Sex addiction is a disorder that can have serious adverse functional consequences. Treatment effectiveness research for sex addiction is currently underdeveloped, and interventions are generally based on the guidelines for treating other behavioral (as well as chemical) addictions. Consequently, there is a need to clinically evaluate tailored treatments that target the specific symptoms of sex addiction. It has been proposed that second-generation mindfulness-based interventions (SG-MBIs) may be an appropriate treatment for sex addiction because in addition to helping individuals increase perceptual distance from craving for desired objects and experiences, some SG-MBIs specifically contain meditations intended to undermine attachment to sex and/or the human body. The current study conducts the first clinical investigation into the utility of mindfulness for treating sex addiction. Case presentation An in-depth clinical case study was conducted involving an adult male suffering from sex addiction that underwent treatment utilizing an SG-MBI known as Meditation Awareness Training (MAT). Following completion of MAT, the participant demonstrated clinically significant improvements in addictive sexual behavior, as well as reductions in depression and psychological distress. The MAT intervention also led to improvements in sleep quality, job satisfaction, and non-attachment to self and experiences. Salutary outcomes were maintained at 6-month follow-up. Discussion and conclusion The current study extends the literature exploring the applications of mindfulness for treating behavioral addiction, and findings indicate that further clinical investigation into the role of mindfulness for treating sex addiction is warranted. PMID:27348560

  17. "We Might Get Some Free Beers": Experience and Motivation for Transactional Sex Among Behaviorally Bisexual Men in Vientiane, Laos.

    PubMed

    Bowring, Anna L; Pasomsouk, Nakhornphet; Hughes, Chad; van Gemert, Caroline; Higgs, Peter; Sychareun, Vanphanom; Hellard, Margaret; Power, Robert

    2016-03-23

    People engaging in transactional sex are considered a key population for HIV prevention. Prior quantitative surveys demonstrated that behaviorally bisexual men in Vientiane, Laos commonly transact sex. In 2013, we conducted a qualitative study to explore behaviorally bisexual men's experience, motivations, and perceptions related to transactional sex in Vientiane. Behaviorally bisexual men were recruited from bars, nightclubs, and dormitories for five focus group discussions (FGDs) and 11 in-depth interviews (n = 31). Additionally, young women were recruited from a university, garment factory, and nightclub for four FGDs (n = 22). Transcripts were translated and thematically coded. Bisexual male participants most commonly described being paid for sex by male-to-female transgender people and buying sex from women. Both male and female participants reported that older, single women pay younger men for sex. Negotiation and direction of sexual transactions are influenced by age, attraction, and wealth. Common motivations for selling sex included the need for money to support family or fund school fees, material gain, or physical pleasure. Transactional sex was often opportunistic. Some behaviorally bisexual men reported selling sex in order to pay another more desirable sex partner or to buy gifts for their regular sex partner. Participants perceived high risk associated with intercourse with female sex workers but not with other transactional sex partners. Health interventions are needed to improve knowledge, risk perception, and health behaviors, but must recognize the diversity of transactional sex in Vientiane. Both physical and virtual settings may be appropriate for reaching behaviorally bisexual men and their partners.

  18. Sex differences in depression during pregnancy and the postpartum period

    PubMed Central

    Comasco, Erika; Georgakis, Marios K.; Skalkidou, Alkistis

    2016-01-01

    Women have a lifetime risk of major depression double that of men but only during their reproductive years. This sex difference has been attributed partially to activational effects of female sex steroids and also to the burdens of pregnancy, childbirth, and parenting. Men, in contrast, have a reproductive period difficult to delineate, and research on the mental health of men has rarely considered the effects of fatherhood. However, the couple goes through a number of potentially stressing events during the reproductive period, and both mothers and fathers are at risk of developing peripartum depression. This Review discusses the literature on maternal and paternal depression and the endocrine changes that may predispose a person to depression at this stage of life, with specific focus on the hypothalamus–pituitary axis, oxytocin, and testosterone levels in men. Important findings on sex differences in the neural correlates of maternal and paternal behavior have emerged, highlighting the relevance of the emotional brain in mothers and the sociocognitive brain in fathers and pointing toward the presence of a common parents' brain. Additionally, sex differences in neurogenesis and brain plasticity are described in relation to peripartum depression. © 2016 The Authors. Journal of Neuroscience Research Published by Wiley Periodicals, Inc. PMID:27870443

  19. Obesity-induced increases in sympathetic nerve activity: sex matters.

    PubMed

    Brooks, Virginia L; Shi, Zhigang; Holwerda, Seth W; Fadel, Paul J

    2015-01-01

    Abundant evidence obtained largely from male human and animal subjects indicates that obesity increases sympathetic nerve activity (SNA), which contributes to hypertension development. However, recent studies that included women reported that the strong relationships between muscle SNA and waist circumference or body mass index (BMI) found in men are not present in overweight and obese women. A similar sex difference in the association between adiposity and hypertension development has been identified in animal models of obesity. In this brief review, we consider two possible mechanisms for this sex difference. First, visceral adiposity, leptin, insulin, and angiotensin II have been identified as potential culprits in obesity-induced sympathoexcitation in males. We explore if these factors wield the same impact in females. Second, we consider if sex differences in vascular reactivity to sympathetic activation contribute. Our survey of the literature suggests that premenopausal females may be able to resist obesity-induced sympathoexcitation and hypertension in part due to differences in adipose disposition as well as its muted inflammatory response and reduced production of pressor versus depressor components of the renin-angiotensin system. In addition, vascular responsiveness to increased SNA may be reduced. However, more importantly, we identify the urgent need for further study, not only of sex differences per se, but also of the mechanisms that may mediate these differences. This information is required not only to refine treatment options for obese premenopausal women but also to potentially reveal new therapeutic avenues in obese men and women.

  20. Why sex hormones matter for neuroscience: A very short review on sex, sex hormones, and functional brain asymmetries.

    PubMed

    Hausmann, Markus

    2017-01-02

    Biological sex and sex hormones are known to affect functional cerebral asymmetries (FCAs). Men are generally more lateralized than women. The effect size of this sex difference is small but robust. Some of the inconsistencies in the literature may be explained by sex-related hormonal differences. Most studies focusing on neuromodulatory properties of sex hormones on FCAs have investigated women during the menstrual cycle. Although contradictions exist, these studies have typically shown that levels of estradiol and/or progesterone correlate with the degree of FCAs, suggesting that sex differences in FCAs partially depend on hormonal state and day of testing. The results indicate that FCAs are not fixed but are hormone dependent, and as such they can dynamically change within relatively short periods throughout life. Many issues raised in this Mini-Review refer not only to FCAs but also to other aspects of functional brain organization, such as functional connectivity within and between the cerebral hemispheres. Our understanding of sex differences in brain and behavior as well as their clinical relevance will improve significantly if more studies routinely take sex and sex hormones into account. © 2016 Wiley Periodicals, Inc.

  1. The X Chromosome of Hemipteran Insects: Conservation, Dosage Compensation and Sex-Biased Expression.

    PubMed

    Pal, Arka; Vicoso, Beatriz

    2015-11-10

    Insects of the order Hemiptera (true bugs) use a wide range of mechanisms of sex determination, including genetic sex determination, paternal genome elimination, and haplodiploidy. Genetic sex determination, the prevalent mode, is generally controlled by a pair of XY sex chromosomes or by an XX/X0 system, but different configurations that include additional sex chromosomes are also present. Although this diversity of sex determining systems has been extensively studied at the cytogenetic level, only the X chromosome of the model pea aphid Acyrthosiphon pisum has been analyzed at the genomic level, and little is known about X chromosome biology in the rest of the order.In this study, we take advantage of published DNA- and RNA-seq data from three additional Hemiptera species to perform a comparative analysis of the gene content and expression of the X chromosome throughout this clade. We find that, despite showing evidence of dosage compensation, the X chromosomes of these species show female-biased expression, and a deficit of male-biased genes, in direct contrast to the pea aphid X. We further detect an excess of shared gene content between these very distant species, suggesting that despite the diversity of sex determining systems, the same chromosomal element is used as the X throughout a large portion of the order.

  2. The X Chromosome of Hemipteran Insects: Conservation, Dosage Compensation and Sex-Biased Expression

    PubMed Central

    Pal, Arka; Vicoso, Beatriz

    2015-01-01

    Insects of the order Hemiptera (true bugs) use a wide range of mechanisms of sex determination, including genetic sex determination, paternal genome elimination, and haplodiploidy. Genetic sex determination, the prevalent mode, is generally controlled by a pair of XY sex chromosomes or by an XX/X0 system, but different configurations that include additional sex chromosomes are also present. Although this diversity of sex determining systems has been extensively studied at the cytogenetic level, only the X chromosome of the model pea aphid Acyrthosiphon pisum has been analyzed at the genomic level, and little is known about X chromosome biology in the rest of the order. In this study, we take advantage of published DNA- and RNA-seq data from three additional Hemiptera species to perform a comparative analysis of the gene content and expression of the X chromosome throughout this clade. We find that, despite showing evidence of dosage compensation, the X chromosomes of these species show female-biased expression, and a deficit of male-biased genes, in direct contrast to the pea aphid X. We further detect an excess of shared gene content between these very distant species, suggesting that despite the diversity of sex determining systems, the same chromosomal element is used as the X throughout a large portion of the order. PMID:26556591

  3. Men who have sex with men and recruit bareback sex partners on the internet: implications for STI and HIV prevention and client education.

    PubMed

    Blackwell, Christopher W

    2008-12-01

    Men who have sex with men (MSM) frequently use Internet-based Web sites to recruit sex partners. Although many MSM users of such sites advocate for safe sex practices in their personal profiles, some users actively recruit sexual partners who wish to participate in anal sexual intercourse without the use of condoms, also known as "bareback" sex. Participating in this sexual practice places both sexual partners at higher risk of HIV transmission. In addition, data indicate this behavior is associated with other high-risk activities such as drug use and communication of other sexually transmitted infections. This article summarizes the literature assessing this phenomenon on the Internet. Specific recommendations are provided for clinicians, health educators, and researchers.

  4. Sex differences and stress across the lifespan

    PubMed Central

    Bale, Tracy L; Epperson, C Neill

    2015-01-01

    Sex differences in stress responses can be found at all stages of life and are related to both the organizational and activational effects of gonadal hormones and to genes on the sex chromosomes. As stress dysregulation is the most common feature across neuropsychiatric diseases, sex differences in how these pathways develop and mature may predict sex-specific periods of vulnerability to disruption and increased disease risk or resilience across the lifespan. The aging brain is also at risk to the effects of stress, where the rapid decline of gonadal hormones in women combined with cellular aging processes promote sex biases in stress dysregulation. In this Review, we discuss potential underlying mechanisms driving sex differences in stress responses and their relevance to disease. Although stress is involved in a much broader range of diseases than neuropsychiatric ones, we highlight here this area and its examples across the lifespan. PMID:26404716

  5. Sex parties: female teen sexual experimentation.

    PubMed

    Toscano, Sharyl Eve

    2006-10-01

    Adolescent participants in a study aimed at exploring the nature and characteristics of girls' dating relationships revealed the phenomenon of sex parties. These teens defined a sex party as an opportunity to engage in sexual contact outside of typical dating relationships. Sexual activity could involve actual intercourse, but usually involved sex acts without vaginal intercourse. Data were collected through 22 semistructured interviews with female adolescents, ages 15-18. All the participants knew of sex parties, however, only a subgroup of these adolescents actually participated in activities loosely defined by teens as sex parties. Alcohol was common at these parties, but female teens asserted that they consumed alcohol willingly to relax, as opposed to being coerced to do so. Some teens expressed regret following participation in a sex party, although none reported sexual coercion or abuse.

  6. [Sex and gender: five challenges for epidemiologists].

    PubMed

    Doyal, L

    2004-03-01

    This paper explores the challenges posed by sex and gender for epidemiologists as they try to integrate sex and gender concerns into their work in more appropriate and effective ways. The first challenge is one of conceptual clarification with considerable confusion still surrounding the use of the terms sex and gender themselves. The second challenge is to develop a broader understanding of the links between biological sex and health. The third challenge is to create a more comprehensive understanding of the ways in which social gender shapes the health of both women and men. The fourth challenge is to ensure that all research designs are both sex and gender sensitive. And the final challenge is to find a strategy for integrating findings on both sex and gender into wider equality agendas. This paper will examine each of these challenges in turn.

  7. Sex steroids and growth hormone interactions.

    PubMed

    Fernández-Pérez, Leandro; de Mirecki-Garrido, Mercedes; Guerra, Borja; Díaz, Mario; Díaz-Chico, Juan Carlos

    2016-04-01

    GH and sex hormones are critical regulators of body growth and composition, somatic development, intermediate metabolism, and sexual dimorphism. Deficiencies in GH- or sex hormone-dependent signaling and the influence of sex hormones on GH biology may have a dramatic impact on liver physiology during somatic development and in adulthood. Effects of sex hormones on the liver may be direct, through hepatic receptors, or indirect by modulating endocrine, metabolic, and gender-differentiated functions of GH. Sex hormones can modulate GH actions by acting centrally, regulating pituitary GH secretion, and peripherally, by modulating GH signaling pathways. The endocrine and/or metabolic consequences of long-term exposure to sex hormone-related compounds and their influence on the GH-liver axis are largely unknown. A better understanding of these interactions in physiological and pathological states will contribute to preserve health and to improve clinical management of patients with growth, developmental, and metabolic disorders.

  8. Same-Sex and Different-Sex Cohabiting Couple Relationship Stability.

    PubMed

    Manning, Wendy D; Brown, Susan L; Stykes, J Bart

    2016-08-01

    Relationship stability is a key indicator of well-being, but most U.S.-based research has been limited to different-sex couples. The 2008 panel of the Survey of Income and Program Participation (SIPP) provides an untapped data resource to analyze relationship stability of same-sex cohabiting, different-sex cohabiting, and different-sex married couples (n = 5,701). The advantages of the SIPP data include the recent, nationally representative, and longitudinal data collection; a large sample of same-sex cohabitors; respondent and partner socioeconomic characteristics; and identification of a state-level indicator of a policy stating that marriage is between one man and one woman (i.e., DOMA). We tested competing hypotheses about the stability of same-sex versus different-sex cohabiting couples that were guided by incomplete institutionalization, minority stress, relationship investments, and couple homogamy perspectives (predicting that same-sex couples would be less stable) as well as economic resources (predicting that same-sex couples would be more stable). In fact, neither expectation was supported: results indicated that same-sex cohabiting couples typically experience levels of stability that are similar to those of different-sex cohabiting couples. We also found evidence of contextual effects: living in a state with a constitutional ban against same-sex marriage was significantly associated with higher levels of instability for same- and different-sex cohabiting couples. The level of stability in both same-sex and different-sex cohabiting couples is not on par with that of different-sex married couples. The findings contribute to a growing literature on health and well-being of same-sex couples and provide a broader understanding of family life.

  9. Interactive effects of culture and sex hormones on the sex role self-concept

    PubMed Central

    Pletzer, Belinda; Petasis, Ourania; Ortner, Tuulia M.; Cahill, Larry

    2015-01-01

    Sex role orientation, i.e., a person's masculinity or femininity, influences cognitive and emotional performance, like biological sex. While it is now widely accepted that sex differences are modulated by the hormonal status of female participants (menstrual cycle, hormonal contraceptive use), the question, whether hormonal status and sex hormones also modulate participants sex role orientation has hardly been addressed previously. The present study assessed sex role orientation and hormonal status as well as sex hormone levels in three samples of participants from two different cultures (Northern American, Middle European). Menstrual cycle phase did not affect participant's masculinity or femininity, but had a significant impact on reference group. While women in their follicular phase (low levels of female sex hormones) determined their masculinity and femininity in reference to men, women in their luteal phase (high levels of female sex hormones) determined their masculinity and femininity in reference to women. Hormonal contraceptive users rated themselves as significantly more feminine and less masculine than naturally cycling women. Furthermore, the impact of biological sex on the factorial structure of sex role orientation as well as the relationship of estrogen to masculinity/femininity was modulated by culture. We conclude that culture and sex hormones interactively affect sex role orientation and hormonal status of participants should be controlled for when assessing masculinity and/or femininity. PMID:26236181

  10. Teens need comprehensive sex education.

    PubMed

    1988-01-01

    Family planning programs throughout the world are making attempts to combat the confusion and ignorance about reproductive health, fertility and contraception among young people. Sex education is becoming part of the curriculum in Asian, Latin American, and Caribbean countries, and some African schools. In Indonesia and other countries educational programs now target parents and young men. Sweden's 1977 program is credited with helping reduce adolescent fertility by 50% and abortion by 25% between 1975 and 1983. In developing countries the emphasis is on outreach efforts. Sri Lanka has population and development projects and Mexico City and Guatemala City offer medical services, counseling, vocational courses and social and cultural activities, as well as sex education and family planning services for young men and women. Family planning groups are also learning to use the media to educate teens. Songs about postponing sexual relations were popularized by the media in Latin America and Caribbean countries, and a commercial film showing the potential disastrous consequences of sexual intercourse was produced in Zimbabwe.

  11. Sex pheromones in mate assessment: analysis of nutrient cost of sex pheromone production by females of the moth Heliothis virescens.

    PubMed

    Foster, Stephen P; Anderson, Karin G

    2015-04-15

    It has been postulated that sex pheromones, in addition to their role in mate recognition and/or finding, may also serve a role in assessment of mate quality. For this, a sex pheromone must give honest information about a signaler's quality, with honesty ensured by a direct metabolic or indirect fitness cost to the signaler. Using a stable isotope tracer-tracee method, we characterized the nutrient pools that fuel sex pheromone production in females of the moth Heliothis virescens, as well as the relative importance of larval- and adult-acquired nutrients to this process. Females used three pools for de novo biosynthesis of sex pheromone, hemolymph trehalose, glycogen (via trehalose) and fat, and produced ca. 25% of pheromone directly from stored (previously synthesized) precursor fatty acids. Pheromone was produced roughly equally from carbohydrate and fat. Adult feeding was very important for pheromone biosynthesis, with a maximum of 65% of de novo biosynthesized pheromone produced from a single adult feed (carbohydrate). Although these nutrient pools are shared with other reproductive physiologies, notably oocyte production, it is unlikely that pheromone production imposes a significant metabolic cost on females, because (i) the amount of nutrients used for pheromone production is negligible compared with that available, (ii) the hemolymph trehalose pool is readily replaceable throughout the adult life, and (iii) in mated females, carbohydrate shortages result in reduced allocation to pheromone.

  12. Radiation and the sex ratio in man.

    PubMed

    SCHULL, W J; NEEL, J V

    1958-08-15

    An analysis of new data concerning the sex of children born to the survivors of the atomic bombings of Hiroshima and Nagasaki, together with a reanalysis of the data previously presented by Neel and Schull (9), reveals significant changes in the sex ratio of these children, changes in the direction to be expected if exposure had resulted in the induction of sex-linked lethal mutations (16).

  13. Sex determination in forensic odontology: A review

    PubMed Central

    Ramakrishnan, K.; Sharma, Subramanya; Sreeja, C.; Pratima, D. Bhavani; Aesha, I.; Vijayabanu, B.

    2015-01-01

    Forensic odontology is the application of dental principles to legal issues. Sex determination is a subdivision of forensic odontology and it is very important especially when information relating to the deceased is unavailable. Sex determination becomes the first priority in the process of identification of a person by a forensic investigator in the case of mishaps, chemical and nuclear bomb explosions, natural disasters crime investigations, and ethnic studies. This article reviews upon the various methods used in sex determination. PMID:26538886

  14. Sex determination in forensic odontology: A review.

    PubMed

    Ramakrishnan, K; Sharma, Subramanya; Sreeja, C; Pratima, D Bhavani; Aesha, I; Vijayabanu, B

    2015-08-01

    Forensic odontology is the application of dental principles to legal issues. Sex determination is a subdivision of forensic odontology and it is very important especially when information relating to the deceased is unavailable. Sex determination becomes the first priority in the process of identification of a person by a forensic investigator in the case of mishaps, chemical and nuclear bomb explosions, natural disasters crime investigations, and ethnic studies. This article reviews upon the various methods used in sex determination.

  15. Sex worker health: San Francisco style

    PubMed Central

    Cohan, D; Lutnick, A; Davidson, P; Cloniger, C; Herlyn, A; Breyer, J; Cobaugh, C; Wilson, D; Klausner, J

    2006-01-01

    Objectives To describe the characteristics of sex workers accessing care at a peer based clinic in San Francisco and to evaluate predictors of sexually transmitted infections (STI). Methods We conducted an observational study of sex workers at St James Infirmary. Individuals underwent an initial questionnaire, and we offered screening for STI at each clinic visit. We performed univariate, bivariate, and multivariable analyses to assess for predictors of STI in this population. Results We saw 783 sex workers identifying as female (53.6%), male (23.9%), male to female transgender (16.1%), and other (6.5%). 70% had never disclosed their sex work to a medical provider. Participants represented a wide range of ethnicities, educational backgrounds, and types of sex work. The most common substance used was tobacco (45.8%). Nearly 40% reported current illicit drug use. Over half reported domestic violence, and 36.0% reported sex work related violence. Those screened had gonorrhoea (12.4%), chlamydia (6.8%), syphilis (1.8%), or herpes simplex virus 2 (34.3%). Predictors of STI included African‐American race (odds ratio (OR) 3.3), male gender (OR 1.9), and sex work related violence (OR 1.9). In contrast, participants who had only ever engaged in collective sex work were less likely to have an STI (OR 0.4). Conclusions The majority of sex workers have never discussed their work with a medical provider. Domestic violence is extremely prevalent as is work related violence. Working with other sex workers appears to be protective of STIs. STI prevention interventions should target African‐American and male sex workers. Addressing violence in the workplace and encouraging sex workers to work collectively may be effective prevention strategies. PMID:16854996

  16. Male sex drive and the maintenance of sex: evidence from Drosophila.

    PubMed

    Singh, Rama S; Artieri, Carlo G

    2010-01-01

    The resolution of the paradoxes surrounding the evolutionary origins and maintenance of sexual reproduction has been a major focus in biology. The operation of sexual selection-which is very common among multicellular organisms-has been proposed as an important factor in the maintenance of sex, though in order for this hypothesis to hold, the strength of sexual selection must be stronger in males than in females. Sexual selection poses its own series of evolutionary questions, including how genetic variability is maintained in the face of sustained directional selection (known as the "paradox of the lek"). In this short review, we present evidence obtained from recent comparative genomics projects arguing that 1) the genomic consequences of sexual selection clearly show that its effect is stronger in males and 2) this sustained selection over evolutionary timescales also has an effect of capturing de novo genes and expression patterns influencing male fitness, thus providing a mechanism via which new genetic variation can be input into to male traits. Furthermore, we argue that this latter process of genomic "masculinization" has an additional effect of making males difficult to purge from populations, as evidence from Drosophila indicates that, for example, many male sexually selected seminal fluid factors are required to ensure maximally efficient reproduction. Newly arising parthenogenic mutations would suffer an immediate reproductive rate disadvantage were these proteins lost. We show that recent studies confirm that genomic masculinization, as a result of "male sex drive," has important consequences for the evolution of sexually dimorphic species.

  17. Update on sexed semen technology in cattle.

    PubMed

    Seidel, G E

    2014-05-01

    The technology in current use for sexing sperm represents remarkable feats of engineering. These flow cytometer/cell sorters can make over 30 000 consecutive evaluations of individual sperm each second for each nozzle and sort the sperm into three containers: X-sperm, Y-sperm and unsexable plus dead sperm. Even at these speeds it is not economical to package sperm at standard numbers per inseminate. However, with excellent management, pregnancy rates in cattle with 2 million sexed sperm per insemination dose are about 80% of those with conventional semen at normal sperm doses. This lowered fertility, in part due to damage to sperm during sorting, plus the extra cost of sexed semen limits the applications that are economically feasible. Even so, on the order of 2 million doses of bovine semen are sexed annually in the United States. The main application is for dairy heifers to have heifer calves, either for herd expansion or for sale as replacements, often for eventual export. Breeders of purebred cattle often use sexed semen for specific matings; thawing and then sexing frozen semen and immediately using the few resulting sexed sperm for in vitro fertilization is done with increasing frequency. Beef cattle producers are starting to use sexed semen to produce crossbred female replacements. Proprietary improvements in sperm sexing procedures, implemented in 2013, are claimed to improve fertility between 4 and 6 percentage points, or about 10%.

  18. On the variability of alligator sex ratios

    USGS Publications Warehouse

    Nichols, J.D.; Chabreck, R.H.

    1980-01-01

    Samples of alligators from wild and 'farm' populations exhibited disproportionate sex ratios. Males predominated among young alligators from wild populations, whereas females were much more abundant than males in the farm population, where resources were superabundant. These results and other considerations lead us to hypothesize that environmental factors influence sex determination in alligators. During favorable environmental conditions natural selection is expected to favor a preponderance of the sex whose individuals exhibit the greater environmentally associated variation in relative fitness. We hypothesize that environmentally associated variation in age at sexual maturity of females produces sufficient variation in relative fitness of females to result in selection for low sex ratios during periods of resource abundance.

  19. Evolutionary stability of sex chromosomes in snakes.

    PubMed

    Rovatsos, Michail; Vukić, Jasna; Lymberakis, Petros; Kratochvíl, Lukáš

    2015-12-22

    Amniote vertebrates possess various mechanisms of sex determination, but their variability is not equally distributed. The large evolutionary stability of sex chromosomes in viviparous mammals and birds was believed to be connected with their endothermy. However, some ectotherm lineages seem to be comparably conserved in sex determination, but previously there was a lack of molecular evidence to confirm this. Here, we document a stability of sex chromosomes in advanced snakes based on the testing of Z-specificity of genes using quantitative PCR (qPCR) across 37 snake species (our qPCR technique is suitable for molecular sexing in potentially all advanced snakes). We discovered that at least part of sex chromosomes is homologous across all families of caenophidian snakes (Acrochordidae, Xenodermatidae, Pareatidae, Viperidae, Homalopsidae, Colubridae, Elapidae and Lamprophiidae). The emergence of differentiated sex chromosomes can be dated back to about 60 Ma and preceded the extensive diversification of advanced snakes, the group with more than 3000 species. The Z-specific genes of caenophidian snakes are (pseudo)autosomal in the members of the snake families Pythonidae, Xenopeltidae, Boidae, Erycidae and Sanziniidae, as well as in outgroups with differentiated sex chromosomes such as monitor lizards, iguanas and chameleons. Along with iguanas, advanced snakes are therefore another example of ectothermic amniotes with a long-term stability of sex chromosomes comparable with endotherms.

  20. The tilapias' chromosomes influencing sex determination.

    PubMed

    Cnaani, A

    2013-01-01

    The sex chromosomes of tilapias (family Cichlidae; genera Oreochromis, Sarotherodon and Tilapia) have been studied for over 50 years, which has gained interest from both agricultural and basic scientific perspectives. Several closely related tilapia species which can interbreed have been studied, and it has been repeatedly demonstrated that there is variation within and between species in the chromosomal sex-determination mechanism. Both male and female heterogametic sex-determination systems have been characterized, as well as epistatic and environmental influences on sex determination. Three different linkage groups (LG1, LG3 and LG23) have been identified as sex-associated chromosomes and have been subjected to further cytogenetic research and analyses of the genes located around the sex-determining region. Variation in the genetic and physical characteristics of the sex chromosomes makes tilapias an excellent model system for studying the evolution of vertebrate sex chromosomes. This review summarizes the progress made along 5 decades of research and the current knowledge of the tilapias' sex chromosomes.

  1. Evolutionary stability of sex chromosomes in snakes

    PubMed Central

    Rovatsos, Michail; Vukić, Jasna; Lymberakis, Petros; Kratochvíl, Lukáš

    2015-01-01

    Amniote vertebrates possess various mechanisms of sex determination, but their variability is not equally distributed. The large evolutionary stability of sex chromosomes in viviparous mammals and birds was believed to be connected with their endothermy. However, some ectotherm lineages seem to be comparably conserved in sex determination, but previously there was a lack of molecular evidence to confirm this. Here, we document a stability of sex chromosomes in advanced snakes based on the testing of Z-specificity of genes using quantitative PCR (qPCR) across 37 snake species (our qPCR technique is suitable for molecular sexing in potentially all advanced snakes). We discovered that at least part of sex chromosomes is homologous across all families of caenophidian snakes (Acrochordidae, Xenodermatidae, Pareatidae, Viperidae, Homalopsidae, Colubridae, Elapidae and Lamprophiidae). The emergence of differentiated sex chromosomes can be dated back to about 60 Ma and preceded the extensive diversification of advanced snakes, the group with more than 3000 species. The Z-specific genes of caenophidian snakes are (pseudo)autosomal in the members of the snake families Pythonidae, Xenopeltidae, Boidae, Erycidae and Sanziniidae, as well as in outgroups with differentiated sex chromosomes such as monitor lizards, iguanas and chameleons. Along with iguanas, advanced snakes are therefore another example of ectothermic amniotes with a long-term stability of sex chromosomes comparable with endotherms. PMID:26702042

  2. Economic analysis of same-sex marriage.

    PubMed

    Portelli, Christopher J

    2004-01-01

    This article applies the neoclassical microeconomic analysis of marriage as developed by Nobel laureate economist Gary Becker to same-sex marriage. The objective is to demonstrate that the economic analysis of marriage supports allowing same-sex marriage, and that same-sex marriages would strengthen the incentive to marry, increase the efficiency of marriage markets, provide for more children to be raised in two-parent optimum environments, and benefit states economically overall. The article concludes with an overview of the economic impact of same-sex marriages on states based on the analysis, data and fiscal information currently available from researchers and economists in the field.

  3. Sex Trading Among Hazardously Drinking Jailed Women

    PubMed Central

    Schonbrun, Yael Chatav; Johnson, Jennifer; Anderson, Bradley J.; Stein, Michael D.

    2016-01-01

    For women involved in sex trading, both alcohol problems and passage through the criminal justice system are highly prevalent. This study is the first to conduct a focused examination of factors associated with sex trading among hazardously drinking, pretrial, jailed women. Cocaine use, social support for alcohol abstinence, and more days incarcerated in the 90 days leading up to the index incarceration were significantly associated with sex trading involvement among alcoholic women. Helping incarcerated alcoholic women reduce cocaine use and improve sober support networks during and following an incarceration may minimize sex trading after release. PMID:28190917

  4. Control of mammalian sex ratio by sexing sperm

    SciTech Connect

    Gledhill, B.L.

    1983-11-01

    Preselection of sex is discussed with emphasis on methods which have claimed success in separating X- and Y-chromosome-bearing sperm. Much of the recent experimental work in separating human X and Y sperm judges the success of enrichment solely by staining for the Y sperm with a quinacrine dye, which causes a bright fluorescence of the long arm of the Y chromosome. This method is questioned because the endpoint may be producing spurious results. Flow sorting is believed to be the first verified separation of mammalian sperm, but the sperm were nonviable. Flow cytometry can be used to quickly determine the success of other enrichment techniques. Bulk separation, as contrasted to separation based on determination of individual sperm characteristics, with 80% enrichment seems to be a reasonable future goal.

  5. Reinventing Sex: The Construction of Realistic Definitions of Sex and Gender.

    ERIC Educational Resources Information Center

    Small, Chanley M.

    1998-01-01

    Presents a set of criteria for constructing a fair and realistic understanding of sex. Recognizes the impact that science can have on social policies and values and recommends that the definitions of sex and gender be carefully crafted. (DDR)

  6. Effects of Sex Education on Sex Information and Sexual Guilt, Attitudes, and Behaviors.

    ERIC Educational Resources Information Center

    Gunderson, Mark Paul; McCary, James Leslie

    1980-01-01

    Sex education has many positive effects such as reduction of sexual guilt, inhibitions, and the double standard, maintaining the traditional values of love and fidelity, and providing a healthier, more comfortable and responsible attitude toward sex. (Author)

  7. The Effects of Sex of Subject, Sex and Attractiveness of Photo on Facial Recognition.

    ERIC Educational Resources Information Center

    Carroo, Agatha W.; Mozingo, R.

    1989-01-01

    Assessed effect of sex of subject, and sex and attractiveness of photo on facial recognition with 25 male and 25 female college students. Found male subjects performed better with male faces with d' prime scores. (Author/ABL)

  8. Sex hormones adjust "sex-specific" reactive and diurnal cortisol profiles.

    PubMed

    Juster, Robert-Paul; Raymond, Catherine; Desrochers, Alexandra Bisson; Bourdon, Olivier; Durand, Nadia; Wan, Nathalie; Pruessner, Jens C; Lupien, Sonia J

    2016-01-01

    Sex differences in stress hormone functions are presumed to depend on sex hormones. And yet, surprisingly few psychoneuroendocrine studies actually assess within-sex variations of testosterone, estradiol, and progesterone when investigating sex-specific activities of the hypothalamic-pituitary-adrenal axis. In this methodological study of 204 healthy adults (60 men), we assessed whether cortisol profiles would differ between the sexes when unadjusted or adjusted for basal sex hormones among both sexes. Reactive cortisol was sampled using 6 saliva samples measured every 10-min as part of the Trier Social Stress Test that generally activates cortisol among men more than women. Diurnal cortisol was sampled over two days at (1) awakening, (2) 30-min thereafter, (3) 1400 h, (4) 1600 h, and (5) bedtime. Sex hormones were collected at baseline before the psychosocial stressor and on two occasions during diurnal cortisol assessment. Repeated-measures analysis of covariance controlled for key covariates in analyses unadjusted or adjusted for sex hormones. Results revealed that men had higher reactive cortisol than women in unadjusted analysis, but this sex difference was attenuated when adjusting for sex hormones. While diurnal cortisol showed no sex differences in unadjusted models, adjusting for sex hormones revealed that women have higher morning cortisol. Correlations using area under the curve formulae revealed intriguing sex-specific associations with progesterone in men and testosterone in women that we propose have implications for social and affective neuroscience. In summary, our results reveal that adjusting for sex hormones alters "sex-specific" reactive and diurnal cortisol profiles.

  9. Correlates of HIV infection among street-based and venue-based sex workers in Vietnam.

    PubMed

    Le, Thuy Tc; Nguyen, Quoc C; Tran, Ha Tt; Schwandt, Michael; Lim, Hyun J

    2016-10-01

    SummaryCommercial sex work is one of the driving forces of the HIV epidemic across the world. In Vietnam, although female sex workers (FSWs) carry a disproportionate burden of HIV, little is known about the risk profile and associated factors for HIV infection among this population. There is a need for large-scale research to obtain reliable and representative estimates of the measures of association. This study involved secondary data analysis of the 'HIV/STI Integrated Biological and Behavioral Surveillance' study in Vietnam in 2009-2010 to examine the correlates of HIV among FSWs. Data collected from 5298 FSWs, including 2530 street-based sex workers and 2768 venue-based sex workers from 10 provinces in Vietnam, were analyzed using descriptive statistics and bivariate and multivariate logistic regression analyses. HIV prevalence among the overall FSW population was 8.6% (n = 453). However, when stratified by FSW subpopulations, HIV prevalence was 10.6% (n = 267) for street-based sex workers and 6.7% (n = 186) for venue-based sex workers. Factors independently associated with HIV infection in the multivariate analysis, regardless of sex work types, were injecting drug use, high self-perceived HIV risk, and age ≥ 25 years. Additional factors independently associated with HIV risk within each FSW subpopulation included having ever been married among street-based sex workers and inconsistent condom use with clients and having sex partners who injected drugs among venue-based sex workers. Apart from strategies addressing modifiable risk behaviours among all FSWs, targeted strategies to address specific risk behaviours within each FSW subpopulation should be adopted.

  10. Sex and testosterone effects on growth, immunity and melanin coloration of nestling Eurasian kestrels.

    PubMed

    Fargallo, Juan A; Martínez-Padilla, Jesús; Toledano-Díaz, Adolfo; Santiago-Moreno, Julián; Dávila, José A

    2007-01-01

    1. Sex differences in testosterone levels and sex-biased sensitivity to testosterone are the basis of some ideas postulated to account for sex-linked environmental vulnerability during early life. However, sex variation in circulating testosterone levels has been scarcely explored and never manipulated at post-natal stages of birds in the wild. 2. We measured and experimentally increased circulating testosterone levels in nestling Eurasian kestrels Falco tinnunculus. We investigated, possible sexual differences in testosterone levels and the effect of this hormone on growth (body mass and tarsus length) and cell-mediated immunity in males and females. We also explored testosterone effects on rump coloration, a highly variable melanin-based trait in male nestlings. We analysed data on circulating testosterone levels of nestlings in 15 additional bird species. 3. Increased levels of testosterone tended to negatively affect body condition, reduced cell-mediated immune responses in male and female nestlings and also diminished the expression of grey rump coloration in male nestlings. No sex differences were observed in testosterone levels in either control or increased testosterone group nestlings, and no interactions were found between sex and treatment. However, male nestlings showed a lower cell-mediated immune response than females in both groups. 4. Our results indicate first, that a high level of testosterone in all nestlings in a brood entails costs, at least in terms of immunity, coloration and probably growth. Secondly, sex differences in post-natal cell-mediated immunity, and consequently in the capacity to prevent diseases, cannot be explained by sex differences in circulating testosterone levels. Finally, by comparing published data at an interspecific level, contradictory sex patterns in circulating testosterone levels have been found, supporting the idea that circulating testosterone might not be a proximate factor causing sex-dependent vulnerability in

  11. Sex and gender considerations in Canadian clinical practice guidelines: a systematic review

    PubMed Central

    Tannenbaum, Cara; Clow, Barbara; Haworth-Brockman, Margaret; Voss, Patrice

    2017-01-01

    Background: The importance of sex and gender in the diagnosis and management of health conditions is well established, but the extent to which this evidence is integrated into clinical practice guidelines remains unknown. We aimed to determine the proportion of Canadian clinical practice guidelines that integrate evidence on sex and gender considerations. Methods: We searched the Canadian Medical Association's CPG Infobase, PubMed, all provincial/territorial websites and websites of professional organizations for English- and French-language Canadian clinical practice guidelines published between January 2013 and June 2015 on selected conditions identified as priorities by policy-makers and practitioners. Citations and text were searched electronically using keyword terms related to sex and gender. Three investigators independently analyzed and categorized the content of text-positive clinical practice guidelines based on clinical relevance for practitioners. Results: Of the 118 clinical practice guidelines that met the inclusion criteria, 79 (66.9%) were text-positive for sex and/or gender keywords; 8 (10%) of the 79 used the keywords only in relation to pregnancy. Of the remaining 71 guidelines, 25 (35%) contained sex-related diagnostic or management recommendations. An additional 5 (7%) contained recommendations for sex-specific laboratory reference values, 29 (41%) referred to differences in epidemiologic features or risk factors only, and 12 (17%) contained nonrelevant mentions of search keywords. Twenty-five (35%) of the text-positive guidelines used the terms "sex" and/or "gender" correctly. Interpretation: Recommendations related to sex and gender are inconsistently reported in Canadian clinical practice guidelines. Guidelines such as the Sex and Gender Equity in Research guidelines may help inform the meaningful inclusion of sex and gender evidence in the development of clinical practice guidelines.

  12. Development of Gender Discrimination: Effect of Sex-Typical and Sex-Atypical Toys.

    ERIC Educational Resources Information Center

    Etaugh, Claire; Duits, Terri L.

    Toddlers (41 girls and 35 boys) between 18 and 37 months of age were given four gender discrimination tasks each consisting of 6 pairs of color drawings. Three of the tasks employed color drawings of preschool girls and boys holding either a sex-typical toy, a sex-atypical toy, or no toy. The fourth employed pictures of sex-typical masculine and…

  13. Effects of Counselor Sex, Student Sex, and Student Attractiveness on Counselors' Judgments.

    ERIC Educational Resources Information Center

    Mercado, Pauline; Atkinson, Donald R.

    1982-01-01

    Studied the effect of client sex and attractiveness on male and female counselors' judgments about students' educational and career potential. Found male counselors showed sex bias when suggesting occupations. Prediction of higher education and occupational status were not related to counselor or student sex or student attractiveness. (Author/JAC)

  14. Differences and Consistency between Same-Sex and Other-Sex Peer Relationships during Early Adolescence.

    ERIC Educational Resources Information Center

    Bukowski, William M.; And Others

    1993-01-01

    Found that individual differences in children's preference for same-sex peers were (1) derived from liking same-sex peers rather than disliking other-sex peers; (2) consistent over long intervals; and (3) related to children's preference for activities that required gross motor skills. (BC)

  15. Birth cohort and the specialization gap between same-sex and different-sex couples.

    PubMed

    Giddings, Lisa; Nunley, John M; Schneebaum, Alyssa; Zietz, Joachim

    2014-04-01

    We examine differences in household specialization between same-sex and different-sex couples within and across three birth cohorts: Baby Boomers, Generation X, and Generation Y. Using three measures of household specialization, we find that same-sex couples are less likely than their different-sex counterparts to exhibit a high degree of specialization. However, the "specialization gap" between same-sex and different-sex couples narrows across birth cohorts. These findings are indicative of a cohort effect. Our results are largely robust to the inclusion of a control for the presence of children and for subsets of couples with and without children. We provide three potential explanations for why the specialization gap narrows across cohorts. First, different-sex couples from more recent birth cohorts may have become more like same-sex couples in terms of household specialization. Second, social and legal changes may have prompted a greater degree of specialization within same-sex couples relative to different-sex couples. Last, the advent of reproductive technologies, which made having children easier for same-sex couples from more recent birth cohorts, could result in more specialization in such couples relative to different-sex couples.

  16. Model Underpinning Treatment for Sex Offenders with Mild Intellectual Disability: Current Theories of Sex Offending

    ERIC Educational Resources Information Center

    Lindsay, William R.

    2005-01-01

    Although many writers have provided a theoretical framework for treatment of mainstream sex offenders, this research has not been extended to sex offenders with mild intellectual disability. My purpose here is to bring together several research strands to provide a theoretical model for working in this field, including theories of sex offending,…

  17. "Dangerous Presumptions": How Single-Sex Schooling Reifies False Notions of Sex, Gender, and Sexuality

    ERIC Educational Resources Information Center

    Jackson, Janna

    2010-01-01

    Due to the recent changes in federal regulations about gender equity in education in the USA, some policy makers have resurrected single-sex public education. Because single-sex schooling ignores the complexity of sex, gender, and sexuality, it sets up a "separate but equal" system that is anything but. Discounting the ways in which gender is…

  18. Female sex work and international sport events - no major changes in demand or supply of paid sex during the 2010 Soccer World Cup: a cross-sectional study

    PubMed Central

    2012-01-01

    Background Important unanswered questions remain on the impact of international sporting events on the sex industry. Speculation about increased demand and supply of sex work often generates significant attention, but also additional funding for HIV programmes. This study assessed whether changes occurred in the demand and supply of paid sex during the 2010 Soccer World Cup in South Africa. Methods Trained sex worker interviewers conducted face-to-face semi-structured interviews among consenting female sex workers during May-September 2010. Using bivariate analyses we compared supply, demand, sexual risk-taking, and police and health services contact pre-World Cup, to levels during the World Cup and after the event. Results No increases were detected in indicators of sex work supply, including the proportion of sex workers newly arrived in the city (< 2.5% in each phase) or those recently entering the trade (≤ 1.5%). Similarly, demand for sex work, indicated by median number of clients (around 12 per week) and amount charged per transaction ($13) remained similar in the three study periods. Only a third of participants reported observing any change in the sex industry ascribed to the World Cup. Self-reported condom-use with clients remained high across all samples (> 92.4% in all phases). Health-care utilisation decreased non-significantly from the pre- to during World Cup period (62.4% to 57.0%; P = 0.075). Across all periods, about thirty percent of participants had interacted with police in the preceding month, two thirds of whom had negative interactions. Conclusions Contrary to public opinion, no major increases were detected in the demand or supply of paid sex during the World Cup. Although the study design employed was unable to select population-based samples, these findings do not support the public concern and media speculation prior to the event, but rather signal a missed opportunity for public health action. Given the media attention on sex work

  19. Sex-specific food intake in whiting Merlangius merlangus.

    PubMed

    Lauerburg, R A M; Keyl, F; Kotterba, P; Floeter, J; Temming, A

    2015-06-01

    In this study, the topic of sexual growth dimorphism in whiting Merlangius merlangus is examined. To understand the magnitude and underlying mechanisms, North Sea International Bottom Trawl Survey (IBTS) data and two additional datasets from the third quarter of 2007 and the first quarter of 2012 were analysed. Merlangius merlangus displays distinct differences in growth parameters between males and females, with females reaching a higher asymptotic length (L∞ ) than males. To identify the mechanisms which lead to higher growth in females, the quantity and the quality of the diet of M. merlangus in the North Sea were investigated to compare the sex-specific energy uptake levels. The diet composition did not differ between the sexes, but females had higher stomach content masses than males of the same total length (LT ), and showed lower proportions of empty stomachs. Moreover, female M. merlangus had higher liver and empty stomach masses compared with males of the same size, which indicates additional sex-specific differences in the metabolic costs and energy allocation patterns. Finally, interannual differences were found in the stomach contents, the share of empty stomachs and liver masses of M. merlangus in the North Sea.

  20. Maternal touch moderates sex differences in juvenile social play behavior.

    PubMed

    Edelmann, Michelle N; Demers, Catherine H; Auger, Anthony P

    2013-01-01

    Additional somatosensory contact of preterm human infants improves a variety of developmental assessment scores, but less is known about its lasting consequences. In rodents, maternal contact may influence the programming of juvenile social play behavior. Therefore, we used a paradigm where we can control the levels of somatosensory contact associated with maternal care. We find that additional somatosensory contact of offspring can have lasting consequences on juvenile social play behavior in a sex-dependent manner. Specifically, additional somatosensory stimuli reduced male social play behavior, but did not change female play behavior. We then examined if this additional infant contact altered some neurobiological substrates associated with play within the juvenile amygdala. Control males had lower levels of 5HT2a receptor mRNA levels contrasted to females; however, similar to its sex-dependent effect on juvenile social play, males that received additional somatosensory contact had higher serotonin 5HT2a receptor mRNA levels than control males. No difference was found in females. As serotonin signaling typically opposes juvenile play behavior, these data suggest that maternal touch can program lasting differences in juvenile social play and 5HT2a receptors mRNA levels within the juvenile amygdala.