Showing papers by "Rutgers University published in 1995"

The Impact Of Human Resource Management Practices On Turnover, Productivity, And Corporate Financial Performance

Abstract: This study comprehensively evaluated the links between systems of High Performance Work Practices and firm performance. Results based on a national sample of nearly one thousand firms indicate that these practices have an economically and statistically significant impact on both intermediate employee outcomes (turnover and productivity) and short- and long-term measures of corporate financial performance. Support for predictions that the impact of High Performance Work Practices on firm performance is in part contingent on their interrelationships and links with competitive strategy was limited. The impact of human resource management (HRM) policies and prac

Introduction to Homological Algebra

Abstract: The landscape of homological algebra has evolved over the last half-century into a fundamental tool for the working mathematician This book provides a unified account of homological algebra as it exists today The historical connection with topology, regular local rings, and semi-simple Lie algebras are also described This book is suitable for second or third year graduate students The first half of the book takes as its subject the canonical topics in homological algebra: derived functors, Tor and Ext, projective dimensions and spectral sequences Homology of group and Lie algebras illustrate these topics Intermingled are less canonical topics, such as the derived inverse limit functor lim1, local cohomology, Galois cohomology, and affine Lie algebras The last part of the book covers less traditional topics that are a vital part of the modern homological toolkit: simplicial methods, Hochschild and cyclic homology, derived categories and total derived functors By making these tools more accessible, the book helps to break down the technological barrier between experts and casual users of homological algebra

A framework for uplink power control in cellular radio systems

Abstract: In cellular wireless communication systems, transmitted power is regulated to provide each user an acceptable connection by limiting the interference caused by other users. Several models have been considered including: (1) fixed base station assignment where the assignment of users to base stations is fixed, (2) minimum power assignment where a user is iteratively assigned to the base station at which its signal to interference ratio is highest, and (3) diversity reception where a user's signal is combined from several or perhaps all base stations. For the above models, the uplink power control problem can be reduced to finding a vector p of users' transmitter powers satisfying p/spl ges/I(p) where the jth constraint p/sub j//spl ges/I/sub j/(p) describes the interference that user j must overcome to achieve an acceptable connection. This work unifies results found for these systems by identifying common properties of the interference constraints. It is also shown that systems in which transmitter powers are subject to maximum power limitations share these common properties. These properties permit a general proof of the synchronous and totally asynchronous convergence of the iteration p(t+1)=I(p(t)) to a unique fixed point at which total transmitted power is minimized. >

Phytoremediation: A Novel Strategy for the Removal of Toxic Metals from the Environment Using Plants

Abstract: Toxic metal pollution of waters and soils is a major environmental problem, and most conventional remediation approaches do not provide acceptable solutions. The use of specially selected and engineered metal-accumulating plants for environmental clean-up is an emerging technology called phytoremediation. Three subsets of this technology are applicable to toxic metal remediation: (1) Phytoextraction--the use of metal-accumulating plants to remove toxic metals from soil; (2) Rhizofiltration--the use of plant roots to remove toxic metals from polluted waters; and (3) Phytostabilization--the use of plants to eliminate the bioavailability of toxic metals in soils. Biological mechanisms of toxic metal uptake, translocation and resistance as well as strategies for improving phytoremediation are also discussed.

Gamma (40-100 Hz) oscillation in the hippocampus of the behaving rat

Abstract: The cellular generation and spatial distribution of gamma frequency (40-100 Hz) activity was examined in the hippocampus of the awake rat. Field potentials and unit activity were recorded by multiple site silicon probes (5- and 16-site shanks) and wire electrode arrays. Gamma waves were highly coherent along the long axis of the dentate hilus, but average coherence decreased rapidly in the CA3 and CA1 directions. Analysis of short epochs revealed large fluctuations in coherence values between the dentate and CA1 gamma waves. Current source density analysis revealed large sinks and sources in the dentate gyrus with spatial distribution similar to the dipoles evoked by stimulation of the perforant path. The frequency changes of gamma and theta waves positively correlated (40-100 Hz and 5-10 Hz, respectively). Putative interneurons in the dentate gyrus discharged at gamma frequency and were phase-locked to the ascending part of the gamma waves recorded from the hilus. Following bilateral lesion of the entorhinal cortex the power and frequency of hilar gamma activity significantly decreased or disappeared. Instead, a large amplitude but slower gamma pattern (25-50 Hz) emerged in the CA3-CA1 network. We suggest that gamma oscillation emerges from an interaction between intrinsic oscillatory properties of interneurons and the network properties of the dentate gyrus. We also hypothesize that under physiological conditions the hilar gamma oscillation may be entrained by the entorhinal rhythm and that gamma oscillation in the CA3-CA1 circuitry is suppressed by either the hilar region or the entorhinal cortex.

Reappraising The Eclectic Paradigm In An Age Of Alliance Capitalism

Abstract: This article discusses the implications of the advent of alliance capitalism for our theorizing about the determinants of MNE activity. In particular, it argues that, due to the increasing porosity of the boundaries of firms, countries and markets, the eclectic, or OLI, paradigm of international production needs to consider more explicitly the competitive advantages arising from the way firms organize their inter-firm transactions, the growing interdependencies of many intermediate product markets, and the widening of the portfolio of the assets of districts, regions and countries to embrace the external economies of interdependent activities.

I-TCP: indirect TCP for mobile hosts

Abstract: IP based solutions to accommodate mobile hosts within existing internetworks do not address the distinctive features of wireless mobile computing. IP-based transport protocols thus suffer from poor performance when a mobile host communicates with a host on the fixed network. This is caused by frequent disruptions in network layer connectivity due to i) mobility and ii) unreliable nature of the wireless link. We describe I-TCP, which is an indirect transport layer protocol for mobile hosts. I-TCP utilizes the resources of Mobility Support Routers (MSRs) to provide transport layer communication between mobile hosts and hosts on the fixed network. With I-TCP, the problems related to mobility and unreliability of wireless link are handled entirely within the wireless link; the TCP/IP software on the fixed hosts is not modified. Using I-TCP on our testbed, the throughput between a fixed host and a mobile host improved substantially in comparison to regular TCP.

Long-Term Effects of Early Childhood Programs on Cognitive and School Outcomes.

Abstract: The extent to which early childhood programs produce long-term benefits in children’s cognitive development, socialization, and school success is a matter of some controversy. This article reviews 36 studies of both model demonstration projects and large-scale public programs to examine the long-term effects of these programs on children from low-income families. The review carefully considers issues related to research design. It includes studies of preschool education, Head Start, child care, and home visiting programs, and focuses primarily on the effects of program participation on children’s cognitive development. Results indicate that early childhood programs can produce large short-term benefits for children on intelligence quotient (IQ) and sizable long-term effects on school achievement, grade retention, placement in special education, and social adjustment. Not all programs produce these benefits, perhaps because of differences in quality and funding across programs. The article concludes with recommendations for future action.

Sharp wave-associated high-frequency oscillation (200 Hz) in the intact hippocampus: network and intracellular mechanisms

Abstract: Sharp wave bursts, induced by a cooperative discharge of CA3 pyramidal cells, are the most synchronous physiological pattern in the hippocampus. In conjunction with sharp wave bursts, CA1 pyramidal cells display a high-frequency (200 Hz) network oscillation (ripple). In the present study extracellular field and unit activity was recorded simultaneously from 16 closely spaces sites in the awake rat and the intracellular activity of CA1 pyramidal cells during the network oscillation was studied under anesthesia. Current source density analysis of the high-frequency oscillation revealed circumscribed sinks and sources in the vicinity of the pyramidal layer. Single pyramidal cells discharged at a low frequency but were phase locked to the negative peak of the locally derived field oscillation. Approximately 10% of the simultaneously recorded pyramidal cells fired during a given oscillatory event. Putative interneurons increased their discharge rates during the field ripples severalfold and often maintained a 200 Hz frequency during the oscillatory event. Under urethane and ketamine anesthesia the frequency of ripples was slower (100–120 Hz) than in the awake rat (180–200 Hz). Halothane anesthesia prevented the occurrence of high-frequency field oscillations in the CA1 region. Both the amplitude (1–4 mV) and phase of the intracellular ripple, but not its frequency, were voltage dependent. The amplitude of intracellular ripple was smallest between -70 and -80 mV. The phase of intracellular oscillation relative to the extracellular ripple reversed when the membrane was hyperpolarized more than -80 mV. A histologically verified CA1 basket cell increased its firing rate during the network oscillation and discharged at the frequency of the extracellular ripple. These findings indicate that the intracellularly recorded fast oscillatory rhythm is not solely dependent on membrane currents intrinsic to the CA1 pyramidal cells but it is a network driven phenomenon dependent upon the participation of inhibitory interneurons. We hypothesize that fast field oscillation (200 Hz) in the CA1 region reflects summed IPSPs in pyramidal cells as a result of high-frequency barrage of interneurons. The sharp wave associated synchronous discharge of pyramidal cells in the millisecond range can exert a powerful influence on retrohippocampal targets and may facilitate the transfer of transiently stored memory traces from the hippocampus to the entorhinal cortex.

Toward a better definition of the restless legs syndrome

Abstract: A large International Restless Legs Syndrome (RLS) Study Group has been formed. As its first task, the group has taken upon itself the role of definig the clinical features of the RLS. As minimal criteria for diagnosis, the group proposes the following four features: (a) desire to move the extremities, often associated with paresthesias/dysesthesias; (b) motor restlessness; (c) worsening of symptoms at rest with at least temporary relief by activity, and (d) worsening of symptoms in the evening or night. Other features commonly seen in RLS include sleep disturbance, periodic limb movements in sleep and similar involuntary movements while awake, a normal neurological examination in the idiopathic from, a tendency for the symptoms to be worse in middle to older age, and, in some cases, a family history suggestive of an autosomal dominant mode of inheritance.

Observation of top quark production in p̄p collisions with the collider detector at fermilab

Abstract: We establish the existence of the top quark using a $67{\mathrm{pb}}^{\ensuremath{-}1}$ data sample of $\overline{p}p$ collisions at $\sqrt{s}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.8\mathrm{TeV}$ collected with the Collider Detector at Fermilab (CDF). Employing techniques similar to those we previously published, we observe a signal consistent with $t\overline{t}$ decay to $\mathrm{WWb}\overline{b}$, but inconsistent with the background prediction by $4.8\ensuremath{\sigma}$. Additional evidence for the top quark is provided by a peak in the reconstructed mass distribution. We measure the top quark mass to be $176\ifmmode\pm\else\textpm\fi{}8(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}10(\mathrm{syst})\mathrm{GeV}{/c}^{2}$, and the $t\overline{t}$ production cross section to be ${6.8}_{\ensuremath{-}2.4}^{+3.6}\mathrm{pb}$.

Mechanisms of Cadmium Mobility and Accumulation in Indian Mustard

Abstract: Indian mustard (Brassica juncea L.), a high biomass crop plant, accumulated substantial amounts of cadmium, with bioaccumulation coefficients (concentration of Cd in dry plant tissue/concentration in solution) of up to 1100 in shoots and 6700 in roots at nonphytotoxic concentrations of Cd (0.1 [mu]g/mL) in solution. This was associated with a rapid accumulation of phytochelatins in the root, where the majority of the Cd was coordinated with sulfur ligands, probably as a Cd-S4 complex, as demonstrated by x-ray absorption spectroscopy. In contrast, Cd moving in the xylem sap was coordinated predominantly with oxygen or nitrogen ligands. Cd concentrations in the xylem sap and the rate of Cd accumulation in the leaves displayed similar saturation kinetics, suggesting that the process of Cd transport from solution through the root and into the xylem is mediated by a saturable transport system(s). However, Cd translocation to the shoot appeared to be driven by transpiration, since ABA dramatically reduced Cd accumulation in leaves. Within leaves, Cd was preferentially accumulated in trichomes on the leaf surface, and this may be a possible detoxification mechanism.

Introduction to signal processing

Abstract: 1. Sampling and Reconstruction. 2. Quantization. 3. Discrete-Time Systems. 4. FIR Filtering and Convolution. 5. z-Transforms. 6. Transfer Functions. 7. Digital Filter Realizations. 8. Signal Processing Applications. 9. DFT/FFT Algorithms. 10. FIR Digital Filter Design. 11. IIR Digital Filter Design. 12. Interpolation, Decimation, and Oversampling. 13. Appendices. References. Index.

Self-Ratings of Health: Do they also Predict change in Functional Ability?

Abstract: Self-ratings of health by individuals responding to surveys have shown themselves to be potent predictors of mortality in a growing number of studies; they appear to contribute significant additional independent information to health status indicators gathered through self-reported health histories or medical examinations. A key question raised by these studies is: What are the mediating processes involved in the association? Specifically, do poor self-ratings increase the risk of disability and morbidity, and are these outcomes intervening steps in the link to mortality? In this report we address the first question, of self-ratings predicting future levels of functional disability, our choice of an index of overall impact of morbidity. Data come from the New Haven Established Populations for Epidemiologic Studies of the Elderly (EPESE) site (N = 2,812). Results show that self-ratings of health in 1982, net of baseline functional ability, health and sociodemographic status, are associated with changes in functional ability over periods of one through six years. These findings extend our understanding of the meaning of excellent, good, fair, and poor ratings of health, and that they have implications not just for survival but for the loss or maintenance of functional ability in daily life.

Paradox and Performance: Toward a Theory of Behavioral Complexity in Managerial Leadership

Abstract: The concept of paradox has received increasing attention in the study of leadership, but these new ideas have not yet had much influence on empirical leadership research. This paper examines the development of these ideas in the literature and attempts to clarify what influence they might have on empirical research. One general implication of the paradox perspective, that more effective leaders generally display a more complex and varied set of behaviors, is then examined empirically with respect to Quinn's Quinn, R. E. 1984. Applying the competing values approach to leadership: Toward an integrative model. J. G. Hunt, R. Stewart, C. Schriesheim, D. Hosking, eds. Managers and Leaders: An International Perspective. Pergamon, New York; Quinn, R. E. 1988. Beyond Rational Management: Mastering the Paradoxes and Competing Demands of High Performance. Jossey-Bass Inc., San Francisco, CA. model of leadership roles. This model is one of few that allows for an empirical test of some of the central ideas developed by the paradox perspective. The paper also contrasts the recent emphasis on cognitive complexity in the organizational literature Weick [Weick, K. 1979. The Social Psychology of Organizing. Random House, New York.], Kiesler and Sproull [Kiesler, S., L. Sproull. 1982. Managerial response to changing environments: Perspectives on problem sensing from social cognition. Admin. Sci. Quart.27548--570.], Streufert and Swezey [Streufert, S., R. W. Swezey. 1986. Complexity, Managers and Organizations. Academic Press, Orlando, FL.], with the relative lack of attention given to behavioral complexity. Cognitive complexity, the paper argues, may well be a necessary condition for the effective practice of leadership. Behavioral complexity, however, must certainly be the sufficient condition. Leadership must inevitably be performed through action, not cognition, and it would thus appear to be time for leadership researchers to begin to develop theories of behavioral as well as cognitive complexity. The paper also examines several existing leadership theories that are consistent with this point of view Mintzberg [Mintzberg, H. 1973. The Nature of Managerial Work. Harper and Row, New York; Mintzberg, H. 1975. The manager's job: Folklore and fact. Harvard Bus. Rev.5349--61.], Yukl [Yukl, G. 1981. Leadership in Organizations. Prentice-Hall, Englewood Cliffs, NJ.]; Bass [Bass, B. M. 1981. Stogdill's Handbook of Leadership: A Survey of Theory in Research. Free Press, New York.], and have in effect already offered useful definitions of behavioral complexity. The empirical results of this study come from a study of 176 executives whose leadership role behavior is rated by their subordinates, and whose effectiveness is rated by their superiors. The analysis relies upon a nontraditional analysis technique based on multidimensional scaling that is well suited to this unorthodox analytic problem. The results show that the more effective executives exhibit a greater variety of leadership roles than their less effective counterparts, and that these roles are much clearer to their subordinates. The results also show that more effective executives show much more of the underlying structure of leadership roles proposed by the Quinn model than do less effective executives. Finally, this paper suggests that the concepts of paradox and behavioral complexity are instrumental to a fuller understanding of managerial leadership, and concludes with a discussion of the future research agenda in this area.

Structure Constants and Conformal Bootstrap in Liouville Field Theory

Abstract: An analytic expression is proposed for the three-point function of the exponential fields in the Liouville field theory on a sphere. In the classical limit it coincides with what the classical Liouville theory predicts. Using this function as the structure constant of the operator algebra we construct the four-point function of the exponential fields and verify numerically that it satisfies the conformal bootstrap equations, i.e., that the operator algebra thus defined is associative. We consider also the Liouville reflection amplitude which follows explicitly from the structure constants.

Hippocampal CA1 interneurons: an in vivo intracellular labeling study

Abstract: Fast spiking interneurons in the CA1 area of the dorsal hippocampus were recorded from and filled with biocytin in anesthetized rats. The full extent of their dendrites and axonal arborizations as well as their calcium binding protein content were examined. Based on the spatial extent of axon collaterals, local circuit cells (basket and O-LM neurons) and long-range cells (bistratified, trilaminar, and backprojection neurons) could be distinguished. Basket cells were immunoreactive for parvalbumin and their axon collaterals were confined to the pyramidal layer. A single basket cell contacted more than 1500 pyramidal neurons and 60 other parvalbumin-positive interneurons. Commissural stimulation directly discharged basket cells, followed by an early and late IPSPs, indicating interneuronal inhibition of basket cells. The dendrites of another local circuit neuron (O-LM) were confined to stratum oriens and it had a small but high-density axonal terminal field in stratum lacunosum-moleculare. The fastest firing cell of all interneurons was a calbindin-immunoreactive bistratified neuron with axonal targets in stratum oriens and radiatum. Two neurons with their cell bodies in the alveus innervated the CA3 region (backprojection cells), in addition to rich axon collaterals in the CA1 region. The trilaminar interneuron had axon collaterals in strata radiatum, oriens and pyramidale with its dendrites confined to stratum oriens. Commissural stimulation evoked an early EPSP-IPSP-late depolarizing potential sequence in this cell. All interneurons formed symmetric synapses with their targets at the electron microscopic level. These findings indicate that interneurons with distinct axonal targets have differential functions in shaping the physiological patterns of the CA1 network.

Macrophages and Inflammatory Mediators in Tissue Injury

Abstract: Tissue injury induced by a diverse group of xenobiotics appears to involve both direct and indirect damage to target cells. Thus, while chemicals may act directly on target cells resulting in toxicity, they may also act indirectly by recruiting and activating resident and inflammatory tissue macrophages. Macrophages are potent secretory cells that release an array of mediators, including proinflammatory and cytotoxic cytokines and growth factors, bioactive lipids, hydrolytic enzymes, reactive oxygen intermediates, and nitric oxide--each of which has been implicated in the pathogenesis of tissue injury. The potential role of macrophages and their mediators in tissue injury has been extensively investigated in the lung and the liver. In both of these tissues, xenobiotics induce localized macrophage accumulation and mediator release. Furthermore, when macrophage functioning is blocked, pulmonary and hepatic injury-induced agents such as ozone, bleomycin, acetaminophen, carbon tetrachloride, and galactosamine are reduced. These data provide direct support for the hypothesis that macrophages and the mediators they release contribute to xenobiotic-induced tissue injury.

Brain-derived neurotrophic factor rapidly enhances synaptic transmission in hippocampal neurons via postsynaptic tyrosine kinase receptors

Abstract: Although neurotrophins are primarily associated with long-term effects on neuronal survival and differentiation, recent studies have shown that acute changes in synaptic transmission can also be produced. In the hippocampus, an area critically involved in learning and memory, we have found that brain-derived neurotrophic factor (BDNF) rapidly enhanced synaptic efficacy through a previously unreported mechanism--increased postsynaptic responsiveness via a phosphorylation-dependent pathway. Within minutes of BDNF application to cultured hippocampal neurons, spontaneous firing rate was dramatically increased, as were the frequency and amplitude of excitatory postsynaptic currents. The increased frequency of postsynaptic currents resulted from the change in presynaptic firing. However, the increased amplitude was postsynaptic in origin because it was selectively blocked by intracellular injection of the tyrosine kinase receptor (Ntrk2/TrkB) inhibitor K-252a and potentiated by injection of the phosphatase inhibitor okadaic acid. These results suggest a role for BDNF in the modulation of synaptic transmission in the hippocampus.

Mutation responsible for the mouse pygmy phenotype in the developmentally regulated factor HMGI-C

Abstract: GROWTH is one of the fundamental aspects in the development of an organism. Classical genetic studies have isolated four viable, spontaneous mouse mutants1 disrupted in growth, leading to dwarfism. Pygmy is unique among these mutants because its phenotype cannot be explained by aberrations in the growth hormone–insulin-like growth factor endocrine pathway2–5. Here we show that the pygmy phenotype arises from the inactivation of Hmgi-c (ref. 6), a member of the Hmgi family7 which function as architectural factors in the nuclear scaffold8 and are critical in the assembly of stereospecific transcriptional complexes9. Hmgi-c and another Hmgi family member, Hmgi(y) (ref. 10), were found to be expressed predominantly during embryogenesis. The HMGI proteins are known to be regulated by cell cycle-dependent phos-phorylation which alters their DNA binding affinity11. These results demonstrate the important role of HMGI proteins in mammalian growth and development.

Bacterial pneumonia in persons infected with the human immunodeficiency virus

Abstract: Background Patients with human immunodeficiency virus (HIV) infection are at increased risk for bacterial pneumonia in addition to opportunistic infection. However, the risk factors for bacterial pneumonia and its incidence in this population are not well defined. Methods In a multicenter, prospective, observational study, we monitored 1130 HIV-positive and 167 HIV-negative participating adults for up to 64 months for pulmonary disease. The HIV-positive group comprised 814 homosexual or bisexual men, 261 injection-drug users, and 55 female partners of HIV-infected men. Results There were 237 episodes of bacterial pneumonia among the HIV-positive participants (rate, 5.5 per 100 person-years), as compared with 6 episodes among the HIV-negative participants (rate, 0.9 per 100 person-years; P<0.001). The rate of bacterial pneumonia increased with decreasing CD4 lymphocyte counts (2.3, 6.8, and 10.8 episodes per 100 person-years in the strata with more than 500, 200 to 500, and fewer than 200 cells per cubic m...

Resistance of Personal Risk Perceptions to Debiasing Interventions

Abstract: The tendency to believe that one's own risk is less than that of others may reduce interest in health-protective behaviors. This article describes 4 attempts to reduce such optimistic biases. In Study 1, New Jersey residents (N = 222) were provided with lists of risk factors for several health problems. This manipulation was strengthened in Study 2 by presenting risk factors in such a way that participants (164 undergraduates) might see their own standing as inferior to that of others. In Study 3, risk factors were presented one at a time, and participants (190 undergraduates) incorporated them into a mental image of a high-risk individual. Finally, 374 undergraduates in Study 4 generated lists of personal attributes that they believed increased their risk. Optimistic biases were found in each study, but none of the manipulations reduced these biases consistently. In contrast, conditions using opposite manipulations often exacerbated the biases. Language: en