The Generation of Direction Selectivity in the Auditory System

Both human speech and animal vocal signals contain frequency-modulated (FM) sounds. Although central auditory neurons that selectively respond to the direction of frequency modulation are known, the synaptic mechanisms underlying the generation of direction selectivity (DS) remain elusive. Here we show the emergence of DS neurons in the inferior colliculus by mapping the three major subcortical auditory nuclei. Cell-attached recordings reveal a highly reliable and precise firing of DS neurons to FM sweeps in a preferred direction. By using in vivo whole-cell current-clamp and voltage-clamp recordings, we found that the synaptic inputs to DS neurons are not direction selective, but temporally reversed excitatory and inhibitory synaptic inputs are evoked in response to opposing directions of FM sweeps. The construction of such temporal asymmetry, resulting DS, and its topography can be attributed to the spectral disparity of the excitatory and the inhibitory synaptic tonal receptive fields

Radical theory for group semiautomata

A Kurosh-Amitsur radical theory is developed for group semiautomata. Radical theory stems from ring theory, it is apt for deriving structure theorems and for a comparative study of properties. Unlikely to conventional radical theories, the radical of a group semiautomaton need not be a subsemiautomaton, so the whole scene will take place in a suitably constructed category. The fundamental facts of the theory are described in § 2. A special feature of the theory, the existence of complementary radicals, is discussed in § 3. Restricting the theory to additive automata, which still comprise linear sequential machines, in § 4 stronger results will be achieved, and also a (sub)direct decomposition theorem for certain semisimple group semiautomata will be proved. Examples are given at appropriate places. The paper may serve also as a framework for future structural investigations of group semiautomata

Online Reverse Auctions: An Overview

Electronic commerce (e-commerce) is the fastest growing area in the U.S. economy with electronic procurement (e-procurement) being a major component, and online reverse auctions (ORAs) have emerged as a key e-procurement tool. Since the mid-1990s, ORAs have been gaining in popularity because of their potentially significant positive impact on the profitability of both the buyers and the sellers. Much has been written about the new purchasing paradigm and numerous stories have been reported recently. This paper is aimed at providing a critical review of ORAs by examining their historical developments, different forms, advantages, and disadvantages. In addition, 10 important factors to consider for successful implementation of ORAs are identified and discussed

Noninvasive prediction of Blood Lactate through a machine learning-based approach.

We hypothesized that blood lactate concentration([Lac]blood) is a function of cardiopulmonary variables, exercise intensity and some anthropometric elements during aerobic exercise. This investigation aimed to establish a mathematical model to estimate [Lac]blood noninvasively during constant work rate (CWR) exercise of various intensities. 31 healthy participants were recruited and each underwent 4 cardiopulmonary exercise tests: one incremental and three CWR tests (low: 35% of peak work rate for 15 min, moderate: 60% 10 min and high: 90% 4 min). At the end of each CWR test, venous blood was sampled to determine [Lac]blood. 31 trios of CWR tests were employed to construct the mathematical model, which utilized exponential regression combined with Taylor expansion. Good fitting was achieved when the conditions of low and moderate intensity were put in one model; high-intensity in another. Standard deviation of fitting error in the former condition is 0.52; in the latter is 1.82 mmol/liter. Weighting analysis demonstrated that, besides heart rate, respiratory variables are required in the estimation of [Lac]blood in the model of low/moderate intensity. In conclusion, by measuring noninvasive cardio-respiratory parameters, [Lac]blood during CWR exercise can be determined with good accuracy. This should have application in endurance training and future exercise industry

His, Hers, or Theirs? Coparenting After the Birth of a Second Child

This study examined changes in coparenting after the birth of a second child. Mothers and fathers from 241 two-parent families reported on their spouse’s coparenting cooperation and conflict with their firstborn child before (prenatal) and four months after the birth of a second child. Parents completed questionnaires (prenatal) on gender role attitudes, marital satisfaction, and firstborn children’s temperamental characteristics. Parents also reported on the secondborn infant’s temperament at 1 month following the birth of the second child. Coparenting conflict increased across the transition, whereas cooperation decreased. Couples in which fathers reported greater marital satisfaction were more cooperative 4 months after the birth. Firstborns’ difficult temperament contributed to less cooperative coparenting by both parents. When mothers had more traditional gender role beliefs, fathers engaged in more conflictual coparenting behavior, and when fathers had more traditional gender role beliefs, mothers engaged in more conflictual coparenting behavior. Mothers, but not fathers, engaged in more coparenting conflict regarding the firstborn when both the firstborn and infant sibling had difficult temperaments

Design of Composite Laminates Containing Pin Loaded Holes

Methods are presented for sizing composite laminates containing one, two, or several pin loaded holes, the holes being arranged either in a single row or in two parallel rows. It is shown how the design parameters (number of holes, hole diameter, hole positions) can be found, which result in the maximum failure load and in the max imum failure load per unit weight.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68243/2/10.1177_002199838401800306.pd

Gender role beliefs, work-family conflict, and father involvement after the birth of a second child

A major task for parents during the transition to second-time parenthood is to help their firstborn adjust to their new roles as siblings. Increased father involvement has been theorized to be protective for firstborn adjustment. Fathers, however, are under increasing pressure to balance both work and family responsibilities. Here we evaluate fathers’ relative involvement in two-child families as a function of family structure, gender role beliefs, and work-family conflict in 222 dual- and single-earner families from the Midwestern region of the United States after the birth of a second child. Couples reported on father involvement with firstborns and infants when the infants were 1, 4, 8, and 12 months old. On average, fathers increased their involvement with infants but decreased their involvement with firstborns. Dual-earner fathers were more involved with their children than single-earner fathers. Although mean levels of father involvement were different between dual- and single-earners, multi-group parallel process trajectory latent growth curve models revealed more similarities than differences between dual- and single-earners in processes guiding father involvement. Both dual- and single-earner fathers engaged in juggling childcare between children and both dual- and single-earner fathers’ involvement with infants was constrained by work-family conflict. Gender role beliefs predicted child care involvement for dual-earner, but not single-earner fathers: more egalitarian gender roles predicted greater involvement with the firstborn immediately after the birth of the second child. Results underscore the need for greater workplace support for fathers’ caregiving roles after the birth of an infant