Hunting in Ancient and Modern Amazonia: Rethinking Sustainability

We use a recently developed computerized modeling technique to explore the long-term impacts of indigenous Amazonian hunting in the past, present, and future. The model redefines sustainability in spatial and temporal terms, a major advance over the static "sustainability indices" currently used to study hunting in tropical forests. We validate the model's projections against actual field data from two sites in contemporary Amazonia and use the model to assess various management scenarios for the future of Manu National Park in Peru. We then apply the model to two archaeological contexts, show how its results may resolve long-standing enigmas regarding native food taboos and primate biogeography, and reflect on the ancient history and future of indigenous people in the Amazon.

Job satisfaction and discrepancies between social and biological timing

The discrepancies between social and biological timing are reflected in shift workers' well-being. The aim of this study was to verify the association between job satisfaction and chronotype among day and night nursing personnel. Several variables, including seniority at the hospital and, in the same shift, sleep duration, quality of sleep, sleepiness and willingness to change sleep timing were also analyzed. Chronotype was calculated by using the morningness-eveningness questionnaire. We studied 514 nursing professionals from a public university hospital. Among the day workers, the higher the morningness, the more the workers were satisfied with their job. In contrast, among night workers, job satisfaction was associated with sleep quality and seniority at the hospital but not with chronotype. Our results suggest that an agreement between work schedule and chronotype may help to increase job satisfaction among diurnal workers.

Voice disorders related to job stress in teaching: a case-control study

This case-control study aimed to test the association between voice disorders and job stress among public schoolteachers in Sao Paulo, Brazil. The groups consisted of teachers with (n = 165) and without (n = 105) voice-related complaints. Both groups answered the questionnaires Conditions of Vocal Production and Job Stress Scale. Analysis of cases and controls showed comparable samples, differing only by vocal symptoms. There was a statistically significant difference between cases and controls in relation to job stress involving high strain (OR = 2.1;95%CI: 1.1-3.9), which places high demands combined with low job control. High strain in cases in this study represents the highest risk of physical and mental disorders for teachers. Loss of voice prevents teachers from continuing in their professional role, eliminates their professional identity, and jeopardizes their career.

The periaqueductal gray as a critical site to mediate reward seeking during predatory hunting

Previous studies using morphine-treated dams reported a role for the rostral lateral periaqueductal gray (rIPAG) in the behavioral switching between nursing and insect hunting, likely to depend on an enhanced seeking response to the presence of an appetitive rewarding cue (i.e., the roach). To elucidate the neural mechanisms mediating such responses, in the present study, we first observed how the rIPAG influences predatory hunting in male rats. Our behavioral observations indicated that bilateral rIPAG NMDA lesions dramatically interfere with prey hunting, leaving the animal without chasing or attacking the prey, but do not seem to affect the general levels of arousal, locomotor activity and regular feeding. Next, using Phaseolus vulgaris-leucoagglutinin (PHA-L), we have reviewed the rIPAG connection pattern, and pointed out a particularly dense projection to the hypothalamic orexinergic cell group. Double labeled PHA-L and orexin sections showed an extensive overlap between PHA-L labeled fibers and orexin cells, revealing that both the medial/perifornical and lateral hypothalamic orexinergic cell groups receive a substantial innervation from the rIPAG. We have further observed that both the medial/perifornical and lateral hypothalamic orexinergic cell groups up-regulate Fos expression during prey hunting, and that rIPAG lesions blunted this Fos increase only in the lateral hypothalamic, but not in the medial/perifornical, orexinergic group, a finding supposedly associated with the lack of motivational drive to actively pursue the prey. Overall, the present results suggest that the rIPAG should exert a critical influence on reward seeking by activating the lateral hypothalamic orexinergic cell group. (C) 2011 Elsevier B.V. All rights reserved.

The role of the ventrolateral caudoputamen in predatory hunting

The ventrolateral caudoputamen (VLCP) is well known to participate in the control of orofacial movements and forepaw usage accompanying feeding behavior. Previous studies from our laboratory have shown that insect hunting is associated with a distinct Fos up-regulation in the VLCP at intermediate rostro-caudal levels. Moreover, using the reversible blockade with lidocaine, we have previously suggested that the VLCP implements the stereotyped actions seen during prey capture and handling, and may influence the motivational drive to start attacking the roaches, as well. However, considering that (1) lidocaine suppresses action potentials not only in neurons, but also in fibers-of-passage, rendering the observed behavioral effect not specific to the ventrolateral caudoputamen; (2) the short lidocaine-induced inactivation period had left a relatively narrow window to observe the behavioral changes; and (3) that the restriction stress to inject the drug could have also disturbed hunting behavior, in the present study, we have examined the role of the VLCP in predatory hunting by placing bilateral NMDA lesions three weeks previous to the behavior testing. We were able to confirm that the VLCP serves to implement the stereotyped sequence of actions seen during prey capture and handling, but the study did not confirm its role in influencing the motivational drive to hunt. Together with other studies from our group, the present work serves as an important piece of information that helps to reveal the neural systems underlying predatory hunting. (C) 2011 Elsevier Inc. All rights reserved.

Um modelo de projeto de layout para ambientes job shop com alta variedade de peças baseado nos conceitos da produção enxuta

Segundo Canem e Williamson (1998), o planejamento do layout é importante, pois normalmente representa os maiores e mais caros recursos da organização. Além disso, a localização e disposição física dos equipamentos no chão de fábrica têm impacto em diversos fatores como nível de estoque em processo, tamanho dos lotes de transferência, dificuldade no gerenciamento das atividades, movimentação de pessoas e produtos, entre outros. Portanto, o estudo de conceitos de arranjo físico e o desenvolvimento de modelos de projeto do layout, que visem a otimização dos recursos de produção, são de vital importância na busca pela melhoria dos sistemas produtivos. Neste contexto, este artigo apresenta um novo modelo de projeto de layout, para ambientes job shop com ampla variedade de peças. O modelo foi desenvolvido durante uma pesquisa de doutorado e foi aplicado em algumas empresas do setor metal mecânico. Os resultados obtidos comprovaram a eficiência do modelo projetado. O objetivo do modelo consiste em conduzir a equipe de projeto de layout a desenvolver alternativas de arranjo físico que estejam em consonância com conceitos e princípios da filosofia de produção enxuta. Vale ressaltar novamente que o modelo foi desenvolvido para ambientes com alta variedade de peças, ambientes esses em que, devido à dificuldade em se projetar o arranjo físico, as empresas terminam por adotar o layout funcional, conceito esse de arranjo físico que apresenta sérios problemas como excesso de transporte, altos níveis de estoques em processo, etc.

Hunting practices among the Awá-Guajá: towards a long-term analysis of sustainability in an Amazonian indigenous community

Indigenous Reserves have played an indispensable role in maintaining forest areas in the Neotropics. In the Amazon there is a clear correlation between these reserves and the presence of forest cover; however, the simple presence of uninterrupted vegetation is no guarantee for the conservation of biodiversity, especially where hunting is practiced. This study describes hunting practices among the Awá-Guajá people from 1993 through 1994, also identifying sociocultural, technological, and demographic changes that have influenced their resource acquisition strategies over the last two decades. The data was obtained through ethnographic fieldwork, recording 78 days of foraging returns, with follow-up visits through 2010. This work provides useful information for an effective diachronic analysis of hunting in this community, by revealing foraging patterns of the early to mid-1990s, and describing community transformations over the last two decades in this locale.

Burnout and work engagement among teachers: an application of the job demands-resources model

The present dissertation focuses on burnout and work engagement among teachers, with especial focus on the Job-Demands Resources Model: Chapter 1 focuses on teacher burnout. It aims to investigate the role of efficacy beliefs using negatively worded inefficacy items instead of positive ones and to establish whether depersonalization and cynism can be considered two different dimensions of the teacher burnout syndrome. Chapter 2 investigates the factorial validity of the instruments used to measure work engagement (i.e. Utrecht Work Engagement Scale, UWES-17 and UWES-9). Moreover, because the current study is partly longitudinal in nature, also the stability across time of engagement can be investigated. Finally, based on cluster-analyses, two groups that differ in levels of engagement are compared as far as their job- and personal resources (i.e. possibilities for personal development, work-life balance, and self-efficacy), positive organizational attitudes and behaviours (i.e., job satisfaction and organizational citizenship behaviour) and perceived health are concerned. Chapter 3 tests the JD-R model in a longitudinal way, by integrating also the role of personal resources (i.e. self-efficacy). This chapter seeks answers to questions on what are the most important job demands, job and personal resources contributing to discriminate burned-out teachers from non-burned-out teachers, as well as engaged teachers from non-engaged teachers. Chapter 4 uses a diary study to extend knowledge about the dynamic nature of the JD-R model by considering between- and within-person variations with regard to both motivational and health impairment processes.

Algoritmi esatti per il Job Shop Scheduling: approcci Mathematical Programming

In questa tesi ci occuperemo di fornire un modello MIP di base e di alcune sue varianti, realizzate allo scopo di comprenderne il comportamento ed eventualmente migliorarne l’efficienza. Le diverse varianti sono state costruite agendo in particolar modo sulla definizione di alcuni vincoli, oppure sui bound delle variabili, oppure ancora nell’obbligare il risolutore a focalizzarsi su determinate decisioni o specifiche variabili. Sono stati testati alcuni dei problemi tipici presenti in letteratura e i diversi risultati sono stati opportunamente valutati e confrontati. Tra i riferimenti per tale confronto sono stati considerati anche i risultati ottenibili tramite un modello Constraint Programming, che notoriamente produce risultati apprezzabili in ambito di schedulazione. Un ulteriore scopo della tesi è, infatti, comparare i due approcci Mathematical Programming e Constraint Programming, identificandone quindi i pregi e gli svantaggi e provandone la trasferibilità al modello raffrontato.

Hunting for warped extra dimensions via loop-induced processes

This thesis is on loop-induced processes in theories with warped extra dimensions where the fermions and gauge bosons are allowed to propagate in the bulk, while the Higgs sector is localized on or near the infra-red brane. These so-called Randall-Sundrum (RS) models have the potential to simultaneously explain the hierarchy problem and address the question of what causes the large hierarchies in the fermion sector of the Standard Model (SM). The Kaluza-Klein (KK) excitations of the bulk fields can significantly affect the loop-level processes considered in this thesis and, hence, could indirectly indicate the existence of warped extra dimensions. The analytical part of this thesis deals with the detailed calculation of three loop-induced processes in the RS models in question: the Higgs production process via gluon fusion, the Higgs decay into two photons, and the flavor-changing neutral current b → sγ. A comprehensive, five-dimensional (5D) analysis will show that the amplitudes of the Higgs processes can be expressed in terms of integrals over 5D propagators with the Higgs-boson profile along the extra dimension, which can be used for arbitrary models with a compact extra dimension. To this end, both the boson and fermion propagators in a warped 5D background are derived. It will be shown that the seemingly contradictory results for the gluon fusion amplitude in the literature can be traced back to two distinguishable, not smoothly-connected incarnations of the RS model. The investigation of the b → sγ transition is performed in the KK decomposed theory. It will be argued that summing up the entire KK tower leads to a finite result, which can be well approximated by a closed, analytical expression.rnIn the phenomenological part of this thesis, the analytic results of all relevant Higgs couplings in the RS models in question are compared with current and in particular future sensitivities of the Large Hadron Collider (LHC) and the planned International Linear Collider. The latest LHC Higgs data is then used to exclude significant portions of the parameter space of each RS scenario. The analysis will demonstrate that especially the loop-induced Higgs couplings are sensitive to KK particles of the custodial RS model with masses in the multi tera-electronvolt range. Finally, the effect of the RS model on three flavor observables associated with the b → sγ transition are examined. In particular, we study the branching ratio of the inclusive decay B → X_s γ