216 research outputs found
The Development Of Old-Growth Structural Characteristics In Second-Growth Forests Of The Cumberland Plateau, Kentucky, U.s.a.
Prior to Euro-American colonization beginning in the late 1700s and subsequent periods of land conversion and intensive resource extraction, most forest on the Cumberland Plateau in Kentucky would have existed in a state meeting one or more of the definitions of old-growth forest in use today. However, many recovering, mature forests currently exist that might be redeveloping old-growth structure and function. To assess the development of old-growth forest characteristics in second-growth forests, 70 - 90 year old (young) and 140 - 160 year old (old) hardwood forests in the Daniel Boone National Forest were examined for a suite of structural characteristics to discern patterns of structural and successional development. Old forest was distinguishable from young forest, having reached thresholds similar to old-growth for presence of large canopy trees, coarse woody debris volume and size distribution, multi-age distribution, age of oldest trees, and complex canopy structure. Both ages of forest met thresholds for total basal area and met some proposed thresholds for stem density. Neither age of forest met suggested minimum densities for old-growth for snags \u3e 30 cm DBH, though old forest had almost three times that of young forest, and nearly approached values reported for old-growth forest. Young and old forest also exhibited different patterns in oak and maple dynamics. Understory maples and overstory oaks recruited synchronously in young forest during the 1920s and 1930s, while recruitment of both species in old forest was temporally more broadly distributed
Temporal and spatial patterns in aerosol insecticide droplet distribution: Modifying application strategies to improve coverage and efficacy
With the phase-out of methyl bromide, treatment of food facilities with aerosol insecticides as part of management programs has increased. The physical layout of the structure, the distribution of equipment and other items within the space, and the application method and location may all cause spatial variation in how the insecticide is deposited, which can result in areas with insufficient or excessive amounts of insecticide applied. The impact of aerosol insecticide application position and dispersal method/formulation on the distribution of droplets was evaluated using a series of applications within the same flour mill room. The spatial pattern of droplet distribution and the effect of treatment on bioassay insects (Tribolium confusum Jacquelin DuVal) was evaluated. There was variation in aerosol concentration and droplet size distributions within room and application position had an impact on the spatial pattern of aerosol droplets. The further away and more obstructed by structural features a location was the lower the aerosol concentration, but concentration was also lower to the side and behind the release point. Evaluation of the temporal pattern in droplet deposition shows that most larger droplets settle out of the air relatively quickly, supporting that idea that shorter shutdown times are be possible. Efficacy was correlated with droplet concentration. The overall conclusion is that there can be considerable variation in distribution of aerosol insecticides and as a result considerable potential for improvement in the effectiveness of these applications.With the phase-out of methyl bromide, treatment of food facilities with aerosol insecticides as part of management programs has increased. The physical layout of the structure, the distribution of equipment and other items within the space, and the application method and location may all cause spatial variation in how the insecticide is deposited, which can result in areas with insufficient or excessive amounts of insecticide applied. The impact of aerosol insecticide application position and dispersal method/formulation on the distribution of droplets was evaluated using a series of applications within the same flour mill room. The spatial pattern of droplet distribution and the effect of treatment on bioassay insects (Tribolium confusum Jacquelin DuVal) was evaluated. There was variation in aerosol concentration and droplet size distributions within room and application position had an impact on the spatial pattern of aerosol droplets. The further away and more obstructed by structural features a location was the lower the aerosol concentration, but concentration was also lower to the side and behind the release point. Evaluation of the temporal pattern in droplet deposition shows that most larger droplets settle out of the air relatively quickly, supporting that idea that shorter shutdown times are be possible. Efficacy was correlated with droplet concentration. The overall conclusion is that there can be considerable variation in distribution of aerosol insecticides and as a result considerable potential for improvement in the effectiveness of these applications
Effects of genetic deficiency of cyclooxygenase-1 or cyclooxygenase-2 on functional and histological outcomes following traumatic brain injury in mice
<p>Abstract</p> <p>Background</p> <p>Neuroinflammation contributes to the pathophysiology of acute CNS injury, including traumatic brain injury (TBI). Although prostaglandin lipid mediators of inflammation contribute to a variety of inflammatory responses, their importance in neuroinflammation is not clear. There are conflicting reports as to the efficacy of inhibiting the enzymes required for prostaglandin formation, cyclooxygenase (COX) -1 and COX-2, for improving outcomes following TBI. The purpose of the current study was to determine the role of the COX isoforms in contributing to pathological processes resulting from TBI by utilizing mice deficient in COX-1 or COX-2.</p> <p>Results</p> <p>Following a mild controlled cortical impact injury, the amount of cortical tissue loss, the level of microglial activation, and the capacity for functional recovery was compared between COX-1-deficient mice or COX-2-deficient mice, and their matching wild-type controls. The deficiency of COX-2 resulted in a minor (6%), although statistically significant, increase in the sparing of cortical tissue following TBI. The deficiency of COX-1 resulted in no detectable effect on cortical tissue loss following TBI. As determined by <sup>3</sup>[H]-PK11195 autoradiography, TBI produced a similar increase in microglial activation in multiple brain regions of both COX-1 wild-type and COX-1-deficient mice. In COX-2 wild-type and COX-2-deficient mice, TBI increased <sup>3</sup>[H]-PK11195 binding in all brain regions that were analyzed. Following injury, <sup>3</sup>[H]-PK11195 binding in the dentate gyrus and CA1 region of the hippocampus was greater in COX-2-deficient mice, as compared to COX-2 wild-type mice. Cognitive assessment was performed in the wild-type, COX-1-deficient and COX-2-deficient mice following 4 days of recovery from TBI. There was no significant cognitive effect that resulted from the deficiency of either COX-1 or COX-2, as determined by acquisition and spatial memory retention testing in a Morris water maze.</p> <p>Conclusion</p> <p>These findings suggest that the deficiency of neither COX-1 nor COX-2 is sufficient to alter cognitive outcomes following TBI in mice.</p
Recommended from our members
A long-term perspective on a modern drought in the American Southeast
The depth of the 2006-9 drought in the humid, southeastern US left several metropolitan areas with only a 60-120 day water supply. To put the region's recent drought variability in a long-term perspective, a dense and diverse tree-ring network—including the first records throughout the Apalachicola-Chattahoochee-Flint river basin—is used to reconstruct drought from 1665 to 2010 CE. The network accounts for up to 58.1% of the annual variance in warm-season drought during the 20th century and captures wet eras during the middle to late 20th century. The reconstruction shows that the recent droughts are not unprecedented over the last 346 years. Indeed, droughts of extended duration occurred more frequently between 1696 and 1820. Our results indicate that the era in which local and state water supply decisions were developed and the period of instrumental data upon which it is based are amongst the wettest since at least 1665. Given continued growth and subsequent industrial, agricultural and metropolitan demand throughout the southeast, insights from paleohydroclimate records suggest that the threat of water-related conflict in the region has potential to grow more intense in the decades to come
BMQ
BMQ: Boston Medical Quarterly was published from 1950-1966 by the Boston University School of Medicine and the Massachusetts Memorial Hospitals
Performance of psychiatric hospital discharges in strict and tolerant environments
Community mental health professionals are greatly concerned with the type of social environment most conducive to helping patients remain outside psychiatric institutions and improving the quality of their lives in the community. This paper examines the tolerance of deviance characterizing significant others in the patient's environment as it relates to community tenure and selected measures of performance and quality of life of the older patient in the community. A possible role is suggested for differential tolerance of deviance in the lives of patients discharged from psychiatric hospitals. Although it would appear that patients may return to the hospital at a higher rate from low tolerance environments, it may be that for patients who remain in the community, the quality of life may be better in low tolerance environments in terms of social interaction and life satisfaction. The deviance model is of value in the continuing efforts to understand the role of the social environment in the community life of discharged patients .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44295/1/10597_2005_Article_BF01435737.pd
Recommended from our members
Tracing future spring and summer drying in southern Africa to tropical lows and the Congo Air Boundary
In southern Africa, models from the 5th Coupled Model Intercomparison Project (CMIP5) predict robust future drying associated with a delayed rainy season onset in the Austral spring and a range of wetting and drying patterns in the Austral summer. This paper relates these rainfall changes to dynamical shifts in two classes of weather systems: the Congo Air Boundary (CAB) and tropical lows. Objective algorithms are used to track these features in CMIP5 model output. It is then established that the climatological locations and frequencies of these systems are reasonably well represented in the CMIP5 models. RCP8.5 end of 21st century projections are compared with historical end of 20th century simulations. Future projections in tropical low locations and frequencies diverge, but indicate an overall average decrease of 15% and in some cases a northward shift. The projected spatial change in the tropical low frequency distribution is weakly positively correlated to the projected spatial change in the Austral summer rainfall distribution. Meanwhile, future projections indicate a 13% increase in CAB frequency from October to December. This is associated with the gradual climatological CAB breakdown occurring half a month later on average in end of 21st century RCP8.5 projections. A delay in the gradual seasonal decline of the CAB prevents rainfall to the south of the CAB’s mean position, most of which is shown to occur on CAB breakdown days, hence creating the Austral spring drying signal and delayed wet season onset. Inter-model variability in the magnitude of CAB frequency increase is able to explain inter-model variability in the projected drying
Intersection between metabolic dysfunction, high fat diet consumption, and brain aging
Deleterious neurochemical, structural, and behavioral alterations are a seemingly unavoidable aspect of brain aging. However, the basis for these alterations, as well as the basis for the tremendous variability in regards to the degree to which these aspects are altered in aging individuals, remains to be elucidated. An increasing number of individuals regularly consume a diet high in fat, with high‐fat diet consumption known to be sufficient to promote metabolic dysfunction, although the links between high‐fat diet consumption and aging are only now beginning to be elucidated. In this review we discuss the potential role for age‐related metabolic disturbances serving as an important basis for deleterious perturbations in the aging brain. These data not only have important implications for understanding the basis of brain aging, but also may be important to the development of therapeutic interventions which promote successful brain aging.Fil: Uranga, Romina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Bruce Keller, Annadora J.. State University of Louisiana; Estados UnidosFil: Morrison, Christopher D.. State University of Louisiana; Estados UnidosFil: Fernandez Kim, Sun Ok. State University of Louisiana; Estados UnidosFil: Ebenezer, Philip J.. State University of Louisiana; Estados UnidosFil: Zhang, Le. State University of Louisiana; Estados UnidosFil: Dasuri, Kalavathi. State University of Louisiana; Estados UnidosFil: Keller, Jeffrey N.. State University of Louisiana; Estados Unido
The Productivity of Care: Contextualizing Care in Situated Interaction and Shedding Light on its Latent Purposes
This is an Accepted Manuscript of an article published by Taylor & Francis in Ethics and Social Welfare on 27th May 2011, available online: http://wwww.tandfonline.com/10.1080/17496535.2011.571063Care work may be connected with emotional and psychological exhaustion but also gratification, reward, and self-empowerment. Caregivers experience both positive and negative emotional states in caring situations, and further studies on the rewarding and energizing aspects of care may help us to broaden our understanding of how we can reduce the degree of burden while increasing the sense of satisfaction. This article shows how the focus on emotion is a necessary step to show the ambivalences and the grey areas connected with the concept of care as well as to challenge the not fully explored assumption that care is often associated with burden and stress and viewed as a result of circumstances. It reports the findings of a micro-situated study of daily care activities among 80 caregivers. Care is seen as a strategic site to grasp deeper insights into the interactional mechanisms through which the emotional dynamics revolving around care produce unanticipated outcomes in terms of symbolic and practical productivity
- …