1,247 research outputs found
Levels of depression among delinquent females and academically gifted females: treatment implications
Includes bibliographical references
Pay, productivity and aging in Major League Baseball
Using panels of player pay and performance from Major League Baseball (MLB), we examine trends in player productivity and salaries as players age. Pooling players of all ability levels leads to a systematic bias in regression coefficients. After addressing this problem by dividing players into talent quintiles, we find that the best players peak about two years later than marginal players, and development and depreciation of ability appear to be more pronounced for players with the highest peak ability levels. Within-career variation, however, is less pronounced than between-player variation, and the talent level of players within a given quintile will typically remain lower than the talent level for rookies in the next higher quintile. Free agents are paid proportionately with their production at all ability levels, whereas young players’ salaries are suppressed by similar amounts.Major League Baseball (MLB); career dynamics; player salaries and performance; quintile analysis
Long-Term Contracts in Major League Baseball
Long-term deals are one tool that both players and franchises use to manage risk. That tool has been much discussed and empirically tested with respect to player shirking, and has more briefly, and only theoretically, discussed with respect to reducing variance in future payrolls. Our work looks at how patterns of use of long-term contracts are affected by changes in contracting rules established through collective bargaining and by expected changes in franchise revenue streams. To accomplish this, we have assembled the most complete dataset of MLB player contracts to date. We analyze changes in contract length and dollar value across players of different ability levels, at different points in their careers (contract status), by position, across CBA agreements, and further examine if new stadiums and new television deals impact contract terms. We confirm the earlier finding that player performance is systematically higher during contract years than during the early portion of a long-term contract. We also find that inclusion of contract length information significantly reduces the unexplained variation in player salaries.Major League Baseball (MLB); long-term contracts; player salaries and performance; collective bargaining agreements (CBA)
The Collective Bargaining Effects of NBA Player Productivity Dynamics
We apply quintile regression methodology to player pay and performance data from the 1985-86 to 2005-06 seasons of the National Basketball Association (NBA). In addition to confirming a finding from Hakes and Turner (2007) of systematic bias in pooled OLS regressions of career paths for salary and productivity, the quintile analysis presents two important results regarding NBA salary structure. Unlike Major League Baseball (MLB), the highest ability veteran NBA players suffer salary suppression relative to the lesser-talented players in their debut-year cohort, indicating rents have been transferred from the most able players to players of lesser abilities. Also, while young NBA players in general suffer from salary suppression relative to free agents, as is well-reported in baseball, our regression results show that the highest-ability young players suffer the most salary suppression, and that the effects of the rookie salary cap in the 1995 NBA Collective Bargaining Agreement depressed salaries for young players of all ability levels.career dynamics; pay and productivity; professional basketball
Nanoseismic monitoring for detection of rockfalls. Experiments in quarry areas
Le frane per crollo da ammassi rocciosi fratturati sono tra i processi di instabilità gravitativa che più frequentemente interessano opere antropiche quali tagli su versanti naturali o artificiali, pareti di cava, trincee stradali, autostradali o ferroviarie, sia per ciò che attiene le aree di distacco che per quelle di accumulo. Nell’ambito dell’applicazione di sistemi di early warning per la gestione del rischio geologico legato a queste tipologie di frana, una sperimentazione della tecnica del monitoraggio nanosismometrico è stata effettuata presso due siti estrattivi non più in attività: le “Pirrere” della Baia di Cala Rossa sull’isola di Favignana (Trapani), in Sicilia, e la cava dismessa di Acuto (Frosinone), in Italia Centrale. Il monitoraggio nanosismometrico è una tecnica di indagine che consente di individuare e localizzare deboli eventi sismici, fino a magnitudo locale (ML) nell’ordine di -3, attraverso l’impiego di quattro sensori sismometrici disposti secondo una specifica geometria di array detta SNS (Seismic Navigation System).
Nel presente lavoro, mediante il software NanoseismicSuite sono stati analizzati 73 eventi di crollo indotti artificialmente attraverso la caduta controllata di blocchi di roccia nei due siti estrattivi abbandonati; sono stati lanciati, simulando fenomeni di rockfalls, rispettivamente 47 blocchi di roccia nella cava di Acuto e 26 eventi in quattro diverse cave a cielo aperto presenti nel settore occidentale di Cala Rossa. Tali eventi, avendo punto epicentrale noto, hanno permesso di determinare il miglior modello di sottosuolo in termini di valori di velocità delle onde P ed S attraverso un’operazione di back analysis. L’analisi è stata, infatti, effettuata variando i valori di velocità e scegliendo quelli relativi all’epicentro teorico ottenuto dall’analisi dell’evento che fosse il più vicino possibile al punto reale di impatto del blocco di roccia. Al fine di valutare la sensibilità della geometria dell’array SNS e l’influenza del sito di installazione sulla capacità di individuare e localizzare gli eventi, le sperimentazioni sono state condotte sia variando il raggio di apertura che la zona di installazione degli array: presso Acuto le acquisizioni di segnale sono state condotte prima con un array SNS con apertura di 20 m e successivamente con un array di apertura 10 m, mentre presso Cala Rossa l’array è stato installato alternativamente all’aperto in un’area di plateau roccioso ed in una galleria facente parte dell’area di cava abbandonata.
Analizzando i dati si è ottenuta una precisione dell’ubicazione epicentrale compresa tra il 10 ed il 22% della distanza che intercorre tra la sorgente e l’array nanosismometrico. Il miglior modello di sottosuolo ottenuto per entrambi i casi di studio è risultato avere una velocità delle onde P pari a 900 m/s ed un rapporto VP/VS pari a 1.73, valori in accordo con le condizioni di intenso stato di fratturazione delle rocce carbonatiche affioranti nelle due zone di cava. Per gli eventi di crollo indotti la magnitudo ML è risultata essere compresa tra -2.8 e -1.3; considerando l’energia sviluppata dall’impatto, legata alla massa del blocco ed all’altezza e alla velocità di caduta, non è stato possibile definire una relazione tra magnitudo ed energia, probabilmente a causa delle differenti caratteristiche del punto di impatto dei diversi blocchi. In generale, si è osservato che la precisione di ubicazione degli eventi, in termini di azimuth e distanza dal reale epicentro, è risultata paragonabile sia variando l’apertura dell’array che variando il sito di installazione. Per il sito sperimentale di Acuto, il processo di picking manuale del tempo di primo arrivo delle onde P è risultato essere più affidabile nel caso di array con apertura pari a 10 m. La sperimentazione effettuata a Cala Rossa ha permesso, invece, di osservare una migliore capacità di individuazione degli eventi nelle tracce relative all’array posizionato in galleria a causa della minore rumorosità di base del sito di installazione.
Tra le registrazioni sismometriche sono state identificate varie tipologie di segnali, oltre a quelli generati dal lancio dei blocchi, alcune riconducibili ad eventi naturali di crollo altre a deboli terremoti. L’analisi dei segnali riferibili alla prima tipologia di eventi naturali, effettuata tenendo in considerazione i modelli di sottosuolo precedentemente calibrati, ha portato all’identificazione in ambedue i siti di aree aventi maggiore suscettibilità a frane per crollo. In definitiva, si può ritenere che i risultati ottenuti in questo studio siano incoraggianti rispetto all’efficacia della tecnica di monitoraggio nanosismometrico nell’individuazione e nell’ubicazione di fenomeni di crollo in roccia e portano a ritenere questa tecnica potenzialmente applicabile in aree in cui tali eventi possono interferire con infrastrutture antropiche.In the frame of early warning and risk mitigation studies for landslide processes involving rock masses, two quarry areas (Cala Rossa Bay in Sicily and Acuto in Central Italy) were monitored with SNS (Seismic Navigation System) arrays. In this study, 73 rockfalls were simulated by launches of rock blocks. This allowed to perform a back analysis for defining the best seismic velocity model of the subsoil half-space; the records related to each impact caused by the rock block launch were managed by the nanoseismic monitoring approach, varying the velocity model to obtain a theoretical epicentre as close as possible to the actual location of the impact point. In order to evaluate the sensibility of the SNS array, the results obtained by different array apertures and positions were compared in terms of azimuth and distance error with respect to the real epicentres. On the other hand, several natural rockfalls were detected; their analysis allowed to identify areas having higher susceptibility to rockfalls by using the previously calibrated subsoil half-space model. Further studies are required to better define the areas prone to rockfall generation in the considered test sites; nevertheless, the here obtained results show an encouraging perspective about the application of the nanoseismic monitoring with respect to vulnerable infrastructures in rockfall prone areas
Gambling problems in treatment for affective disorders:Results from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC)
BACKGROUND: Gambling problems co-occur frequently with other psychiatric difficulties and may complicate treatment for affective disorders. This study evaluated the prevalence and correlates of gambling problems in a U. S. representative sample reporting treatment for mood problems or anxiety.METHODS: n=3007 respondents indicating past-year treatment for affective disorders were derived from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Weighted prevalence estimates were produced and regression analyses examined correlates of gambling problems.RESULTS: Rates of lifetime and past-year problem gambling (3+DSM-IV symptoms) were 3.1% (95% CI=2.4-4.0%) and 1.4% (95% CI=0.9-2.1%), respectively, in treatment for any disorder. Rates of lifetime problem gambling ranged from 3.1% (95% CI=2.3-4.3%) for depression to 5.4% (95% CI=3.2-9.0%) for social phobia. Past-year conditions ranged from 0.9% (95% CI=0.4-2.1%) in dysthymia to 2.4% (95% CI=1.1-5.3%) in social phobia. Higher levels were observed when considering a spectrum of severity (including \u27at-risk\u27 gambling), with 8.9% (95% CI=7.7-10.2%) of respondents indicating a history of any gambling problems (1+ DSM-IV symptoms). Lifetime gambling problems predicted interpersonal problems and financial difficulties, and marijuana use, but not alcohol use, mental or physical health, and healthcare utilisation.LIMITATIONS: Data were collected in 2001-02 and were cross-sectional. CONCLUSIONS: Gambling problems occur at non-trivial rates in treatment for affective disorders and have mainly psychosocial implications. The findings indicate scope for initiatives to identify and respond to gambling problems across a continuum of severity in treatment for affective disorders
Reconstruction of Network Evolutionary History from Extant Network Topology and Duplication History
Genome-wide protein-protein interaction (PPI) data are readily available
thanks to recent breakthroughs in biotechnology. However, PPI networks of
extant organisms are only snapshots of the network evolution. How to infer the
whole evolution history becomes a challenging problem in computational biology.
In this paper, we present a likelihood-based approach to inferring network
evolution history from the topology of PPI networks and the duplication
relationship among the paralogs. Simulations show that our approach outperforms
the existing ones in terms of the accuracy of reconstruction. Moreover, the
growth parameters of several real PPI networks estimated by our method are more
consistent with the ones predicted in literature.Comment: 15 pages, 5 figures, submitted to ISBRA 201
Does the Federal Reserve Lexicographically Order Its Policy Objectives?
We test a Federal Reserve reaction function for threshold effects among the Fed's policy objectives. We find evidence that the Fed responds with greater intensity to a policy objective when that policy objective moves beyond acceptable bounds. We also find that the Fed only responds to lesser objectives when its primary, or threshold, objective is within acceptable bounds--a behavior which can be described as lexicographic ordering. Finally, our results suggest that Fed policy is becoming increasingly responsive to inflation and less responsive to unemployment.Fed; Policy
TI Lesson Plan: Volume Area and Mass
To give the students visual models to understand the concept of area, volume, and the ratio of area to volume
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