290 research outputs found
Avian ecological succession in the Amazon: A long-term case study following experimental deforestation
Approximately 20% of the Brazilian Amazon has now been deforested, and the Amazon is currently experiencing the highest rates of deforestation in a decade, leading to large-scale land-use changes. Roads have consistently been implicated as drivers of ongoing Amazon deforestation and may act as corridors to facilitate species invasions. Long-term data, however, are necessary to determine how ecological succession alters avian communities following deforestation and whether established roads lead to a constant influx of new species. We used data across nearly 40 years from a large-scale deforestation experiment in the central Amazon to examine the avian colonization process in a spatial and temporal framework, considering the role that roads may play in facilitating colonization. Since 1979, 139 species that are not part of the original forest avifauna have been recorded, including more secondary forest species than expected based on the regional species pool. Among the 35 species considered to have colonized and become established, a disproportionate number were secondary forest birds (63%), almost all of which first appeared during the 1980s. These new residents comprise about 13% of the current community of permanent residents. Widespread generalists associated with secondary forest colonized quickly following deforestation, with few new species added after the first decade, despite a stable road connection. Few species associated with riverine forest or specialized habitats colonized, despite road connection to their preferred source habitat. Colonizing species remained restricted to anthropogenic habitats and did not infiltrate old-growth forests nor displace forest birds. Deforestation and expansion of road networks into terra firme rainforest will continue to create degraded anthropogenic habitat. Even so, the initial pulse of colonization by nonprimary forest bird species was not the beginning of a protracted series of invasions in this study, and the process appears to be reversible by forest succession
A graphene bilayer channel transistor with a very high Ion/Ioff ratio, graphene single electron devices and graphene nano-mechanical structures for NEMS
Age and information preference: Neutral information sources in decision contexts
Do adults of different ages differ in their focus on positive, negative, or neutral information when making decisions? Some research suggests an increasing preference for attending to and remembering positive over negative information with advancing age (i.e., an age-related positivity effect). However, these prior studies have largely neglected the potential role of neutral information. The current set of three studies used a multimethod approach, including self-reports (Study 1), eye tracking and choice among faces reflecting negative, neutral, or positive health-related (Study 2) and leisure-related information (Study 3). Gaze results from Studies 2 and 3 as well as self-reports from Study 1 showed a stronger preference for sources of neutral than for positive or negative information regardless of age. Findings also suggest a general preference for decision-relevant information from neutral compared to positive or negative sources. Focusing exclusively on the difference between positive (happy) and negative (angry) faces, results are in line with the age-related positivity effect (i.e., the difference in gaze duration between happy and angry faces was significantly larger for older than for younger adults). These findings underscore the importance of neutral information across age groups. Thus, most research on the positivity effect may be biased in that it does not consider the strong preference for neutral over positive information
Clinical Symptoms Contributing to Zenker\u27s Diverticulum Repair: A Retrospective Review
Objective: Zenker\u27s diverticulum (ZD) is usually associated with dysphagia and other symptoms due to the interrelated functions of several systems. Surgical management of ZD is effective for all sizes of diverticula, but not all patients decide to undergo surgery. The purpose of this study was to determine the relationship between clinical presentation and patients\u27 decision to undergo surgical repair.
Subjects and methods: This is a retrospective study including 165 patients with ZD treated over the last 11 years. Data collection includes patients\u27 chief complaints and symptoms, medical history, findings on radiologic swallow evaluations, and patients\u27 decision to undergo surgery. Pearson correlation and logistic regression analysis were performed.
Results: Among our cohort, dysphagia was the most prevalent symptom (89.1%), followed by cough (65.5%) and regurgitation (58.8%). Dysphonia was prevalent among patients with a small-sized ZD. Our logistic regression model showed that patients\u27 decision to undergo surgical repair could be predicted by diverticula size (ÎČ=1.10, p=0.002) and the presence of dysphagia (ÎČ=1.91, p=0.005), cough (ÎČ=1.01, p=0.042), and dysphonia (ÎČ=-1.37, p=0.024).
Conclusion: Patients\u27 decision to undergo surgery usually involves interrelated factors, including symptomatic burden, presence of comorbidities, and recommendation of the surgeon. This study has identified that diverticula size and the presence of dysphagia, cough, and dysphonia are significant factors influencing decision-making for surgical repair in patients with ZD
A social constructivist approach to introducing skills for employment to Foundation Degree students
Expectations for higher education providers to produce graduates ready for the workplace have shaped provision, with the introduction of the Foundation Degree, and expectations of an employability component within higher education programmes. This paper reports on an intervention for three groups of foundation degree students, which introduces them to ideas of skills for employability. An initial evaluation was followed up two months later exploring the longer-term impact and connections within students' programmes of study and data were captured from employers and tutors supporting this intervention. In agreement with similar studies, benefits for students were identified. However, this research reinforces the challenging nature of the employability agenda, particularly within the context of Foundation Degrees and their dual vocational-academic remit. This paper suggests there is a case to be made for a social constructivist approach within programmes and institutions for promoting awareness and consistency in developing student employability skills. © 2013 © 2013 Further Education Research Association
SPACE USE, DIURNAL MOVEMENT, AND ROOSTING OF A VARIEGATED ANTPITTA (GRALLARIA VARIA) IN CENTRAL AMAZONIA
Abstract â The Variegated Antpitta (Grallaria varia) is the largest member of the terrestrial insectivores guild within its Amazonian range. Despite the birdâs large size and loud vocalizations, however, basic aspects of G. variaâs natural history remain poorly understood. In this study, we conducted intensive tracking of one individual in a nature reserve in the state of Amazonas, Brazil, describing â for the first time with radio telemetry â space use, movement patterns, and roosting sites of G. varia. Over the course of 50 days in July and August 2017, the tracked individual moved slowly through a home range covering ⌠17.6 ha and was generally quiet, singing at only two of 68 locations that together comprised its home range. Of five roosting sites, four included visual observations where the bird slept 3â7 (mean 4.5) m aboveground in relatively open midâstory trees. We found no evidence of commutes to regular roost sites as all nocturnal locations were located close (mean 59.6 m, range 24â101 m) to the most recent diurnal locations. Slow movements on the ground without commutes to foraging or roosting sites help explain low capture rates in mist nets for this species. Our telemetry data suggest that G. varia home range may be larger than previously estimated in studies that relied heavily on bird vocalizations to determine area needs, though such methods may yield adequate results at times when birds vocalize frequently. Regardless, large area requirements help to explain the disappearance of G. varia documented in tropical forest fragments.Resumo â Uso do espaço, movimento diurno e ĂĄreas de dormitĂłrio do tovacuçu (Grallaria varia) na AmazĂŽnia Central O tovacuçu (Grallaria varia) Ă© o maior dos insetĂvoros terrestres dentro da sua distribuição na AmazĂŽnia. Apesar do seu tamanho e vocalizaçÔes altas, alguns aspectos bĂĄsicos da histĂłria natural de G. varia ainda sĂŁo pouco compreendidos. Neste estudo, nĂłs realizamos o rastreamento intensivo de um indivĂduo em uma reserva natural no estado do Amazonas, Brasil, descrevendo â pela primeira vez com rĂĄdioâtelemetria â o uso do espaço, padrĂ”es de movimento, e poleiros noturnos de G. varia. Durante 50 dias em julho e agosto de 2017, este indivĂduo de G. varia moveuâse lentamente na sua ĂĄrea de vida (cobrindo aproximadamente 17,9 ha) geralmente em silĂȘncio, cantando somente em duas das 68 localizaçÔes que, juntas, formam sua ĂĄrea de vida. Dos cinco poleiros noturnos encontrados, quatro incluĂram observaçÔes visuais onde a ave dormiu de 3 a 7 (mĂ©dia 4,5) m acima do solo, em um ambiente relativamente aberto no subâbosque. NĂŁo encontramos evidĂȘncia de viagens regulares para poleiros usados a noite, uma vez que todos os poleiros noturnos estavam perto (mĂ©dia 59,6; amplitude 24â101 m) das localizaçÔes diurnas mais recentes do indivĂduo. Moâvimentos lentos no solo, sem deslocamentos para sĂtios de forrageamento ou poleiros noturnos, ajudam a explicar a baixa taxa de captura em redesâdeâneblina para esta espĂ©cie. Os dados de telemetria sugerem que a ĂĄrea de vida de G. varia Ă© maior do que se estimava previamente em estudos que se baseavam principalmente em vocalizaçÔes para determinar o seu tamanho, embora tais mĂ©todos possam produzir resultados adequados quando as aves vocalizam com frequĂȘncia. O requerimento de grandes ĂĄreas de vida ajuda a explicar o desaparecimento de registros de G. varia em fragmentos de floresta tropical
Using EMCS Data to Document and Improve Air Handler Performance
Traditionally, energy monitoring and control
systems (EMCS) have been used, as the name
implies, to monitor and control heating, ventilating
and air conditioning systems, however, this paper
will identify other benefits of an EMCS. Recording
EMCS data on a periodic basis, typically once an
hour, and analyzing it using a commercial off the
shelf database program has proven to be an effective
method to improve and document indoor air quality,
energy savings; and provide continuous controls
commissioning and performance diagnostics.
Identification of system problems is the key to
having an efficient and reliable EMCS. Once
identified they can be scheduled to be repaired and
system integrity will be maintained. Specific
diagnostic and functionality programming include:
Identifying leaking heating and cooling
control valves
Identifying simultaneous heating and cooling
operation
Identifying proper air side economizer
operation
Identifying faulty components
Identifying cooling and heating system
problems
Calculating ventilation rates
Calculating energy wastes and savings
Finally, using EMCS data in the non-traditional
manner has saved thousands of dollars in operation
and maintenance costs by providing a hands-off
"tool" to diagnose air handler performance
MRI measures of middle cerebral artery diameter in conscious humans during simulated orthostasis.
BACKGROUND AND PURPOSE: The relationship between middle cerebral artery (MCA) flow velocity (CFV) and cerebral blood flow (CBF) is uncertain because of unknown vessel diameter response to physiological stimuli. The purpose of this study was to directly examine the effect of a simulated orthostatic stress (lower body negative pressure [LBNP]) as well as increased or decreased end-tidal carbon dioxide partial pressure (P(ET)CO(2)) on MCA diameter and CFV.
METHODS: Twelve subjects participated in a CO(2) manipulation protocol and/or an LBNP protocol. In the CO(2) manipulation protocol, subjects breathed room air (normocapnia) or 6% inspired CO(2) (hypercapnia), or they hyperventilated to approximately 25 mm Hg P(ET)CO(2) (hypocapnia). In the LBNP protocol, subjects experienced 10 minutes each of -20 and -40 mm Hg lower body suction. CFV and diameter of the MCA were measured by transcranial Doppler and MRI, respectively, during the experimental protocols.
RESULTS: Compared with normocapnia, hypercapnia produced increases in both P(ET)CO(2) (from 36+/-3 to 40+/-4 mm Hg, P
CONCLUSIONS: Under the conditions of this study, changes in MCA diameter were not detected. Therefore, we conclude that relative changes in CFV were representative of changes in CBF during the physiological stimuli of moderate LBNP or changes in P(ET)CO(2)
Imposing legality : hegemony and resistance under the EU Forest Law Enforcement, Governance, and Trade (FLEGT) initiative
Timber legality trade restrictions and verification are a bundle of contemporary mechanisms triggered by global concerns about forest degradation and deforestation. The European Union Forest Law Enforcement, Governance and Trade initiative is a significant effort to not only screen out illegal timber and wood products from the EU, but also support trading partner countries to improve their legality definitions and verification processes. But by using bilateral agreements (Voluntary Partnership Agreements) as a key mechanism, the EU legitimizes trade partner nation-states as the authority to decide what is legal. We engage in a theoretical debate about the complexities of the meaning of legality, and then analyze empirical data collected from interviews in Ghana, Indonesia, Vietnam and Europe with policy, civil society and industry actors to understand how different actors understand legality. We find hegemonic notions of Westphalian statehood at the core of 'global' notions of legality and often contrast with local understandings of legality. Non-state actors understand these hegemonic notions of legality as imposed upon them and part of a colonial legacy. Further, notions of legality that fail to conform with hegemonic understandings are readily framed by nation- states as immoral or criminal. We emphasize the importance of understanding these framings to elucidate the embedded assumptions about what comprises legality within assemblages of global actors.Peer reviewe
Young childrenâs future-oriented reasoning for self and other: Effects of conflict and perspective
In some contexts, children more accurately predict anotherâs future than their own. Adopting anotherâs perspective may provide psychological distance. This distance may be especially beneficial when present and future desires conflict. Here, only age and conflict systematically affected preschoolersâ future thinking. Older preschoolers were less affected by conflict than younger preschoolers. Young children reason more adaptively about the future (e.g., predicting preferences and delaying gratification) when they are asked to think about another personâs perspective versus their own perspective. An explanation for this âother-over-selfâ advantage is that in contexts where current (e.g., small reward now) and future (e.g., larger reward later) desires conflict, adopting the perspective of another person provides psychological distance and hence more adaptive decision making by reducing conflict. We tested this hypothesis in 158 preschoolers using a battery of representative future-oriented reasoning tasks (Preferences, Delay of Gratification, Picture Book, and âSpoonâ) in which we varied the perspective children adopted (self or other) and the level of conflict between current and future desires (high or low). We predicted that perspective and conflict would interact such that children would benefit most from taking the perspective of âotherâ when conflict was high. Although results did not support this hypothesis, we found significant effects of conflict; children reasoned more optimally on our low-conflict task condition than on our high-conflict task condition, and these differences did not appear to be related to inhibitory control. The effect of conflict was most marked in younger preschoolers, resulting in Age Ă Conflict interactions on two of our four tasks. An other-over-self advantage (i.e., perspective effect) was detected on the Preferences task only. These results add to the growing body of literature on childrenâs future thinking by showing the important role of conflict (and its interaction with age) in the accuracy with which children reason about the future
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