4,744 research outputs found
Digital storytelling : building 21st century literacy skills in the secondary classroom
Digital storytelling has been a popular activity in technologically well-equipped classrooms, and is gaining popularity due to its ability to help build important 21st century skills for learners and engaging lessons for instructors. This paper reviewed twenty peer-evaluated investigations from 2001 to 2010, citing five original qualitative case studies, twelve research-based papers regarding digital narratives and the skills needed for the 21st century learner. Included in this review is a definition of digital storytelling via a detailed model, an explanation of the 21st century literacies, obstacles to integrating digital narratives, and discussion of related communication skills. Recommendations were made based upon the review encouraging the continued implementation of digital narratives in the classroom, and the promotion of this activity as a viable skill builder
Immunological and Physiological Differences Between Layer- and Broiler Chickens after Concurrent Intratracheal Administration of Lipopolysaccharide and Human Serum Albumin
Layers and broilers were concurrently intratracheally challenged with 0.5 mg Lipopolysaccharide (LPS) and 0.1 mg Human Serum Albumin (HuSA) at 3 weeks of age. Specific total and isotype-specific (IgM, IgG, IgA) Antibody (Ab) responses to HuSA during 3 weeks following immunization, cellular in vitro mitogen responses to Concanavalin A (Con A) and specific cellular responses in vitro to different dosages of HuSA, blood serotonin (5-HT) levels, plasma Corticosterone (CORT) levels at 6 weeks of age and ex vivo nitric oxide (NO) production in the presence of LPS, respectively, were measured in all birds. Higher in vitro cellular responses to HuSA, but not Con A, were found in the broilers than in the layers. Also higher total, IgM and IgG antibody responses to HuSA were found in the broilers. Higher ex vivo NO production was found in the layers. A heavier spleen weight was found in the broilers, but relative spleen weight was higher in the layers. The broilers grew much heavier and also maintained a higher growth during the first 24 and 48 h after i.t. challenge with LPS and HuSA. No breed effect was found for body temperature responses after i.t. challenge. Blood 5-HT levels and plasma CORT levels were significantly higher in the layers. Number and type of significant correlations between 5-HT levels, cachectin response to LPS, antibody levels and cellular immunity differed between breeds. Our data suggest comparable immune responses to i.t. HuSA challenge in broilers and layers of similar age and confirm the earlier reported higher humoral immune response in broilers. On the other hand, the cachectin response to LPS differed between broilers and layers. Our results do not confirm the earlier reported higher cellular immune response of layers. Different significant relationships between physiological parameters in broilers and layers were found. Our results suggest that selection for enhanced growth does not necessarily affect specific immune competence of poultr
Climigration? Population and climate change in Arctic Alaska
Residents of towns and villages in Arctic Alaska live on âthe front line of climate change.â Some communities face immediate threats from erosion and flooding associated with thawing permafrost, increasing river flows, and reduced sea ice protection of shorelines. The term climigration, referring to migration caused by climate change, originally was coined for these places. Although initial applications emphasized the need for government relocation policies, it has elsewhere been applied more broadly to encompass unplanned migration as well. Some historical movements have been attributed to climate change, but closer study tends to find multiple causes, making it difficult to quantify the climate contribution. Clearer attribution might come from comparisons of migration rates among places that are similar in most respects, apart from known climatic impacts. We apply this approach using annual 1990â2014 time series on 43 Arctic Alaska towns and villages. Within-community time plots show no indication of enhanced out-migration from the most at-risk communities. More formally, there is no significant difference between net migration rates of at-risk and other places, testing several alternative classifications. Although climigration is not detectable to date, growing risks make either planned or unplanned movements unavoidable in the near future
On-farm Examples of Alternative Winter Farrowing Systems
There is growing demand in Iowa for pigs raised outdoors or in deep-bedded systems without the use of antibiotics, growth promotants, or animal by-products. Currently many producers selling naturally-raised pork market their animals to a company that requires adherence to the Animal Welfare Instituteâs (AWI) Animal Welfare Standards. One of the key components of these standards is the requirement for bedding and the prohibition of farrowing crates. While a pasture farrowing system is effective during most of the spring, summer, and fall, an alternative system is needed in order to farrow pigs in the winter for the naturally-raised pork market.
There are a variety of farrowing systems currently being used during cold weather to farrow pigs for the natural pork market. In general, all rely upon a primary heat source capable of maintaining a room temperature of at least 50Âș F and auxiliary heat sources (heat lamps, bedding pack, confined space) to create a warmer microclimate for the young pigs. The use of adequate bedding and a design in harmony with the natural instincts of the hogs are key to the success of the example systems. A final critical consideration is a breeding program that insures sows in a particular room farrow within a short time frame (7 days or less).
Three unique systems, detailed in this report are free stalls in retrofitted buildings, the Swedish system, and greenhouse with radiant tube heater. A relative comparison of the three winter farrowing alternatives is shown in table 1. No system has a clear advantage over the others, but each system has its own unique strengths and management requirements. Producers interested in capitalizing on the growing demand for natural pork born in the winter should consider their individual resources and goals as they adopt a system to meet their needs
Alternative Winter Farrowing Demonstration Project: A Progress Report
There is growing demand in Iowa for pigs raised outdoors or in a deep-bedded system without the use of antibiotics, growth promotants, or animal by-products. Currently, most producers selling naturally-raised pork, market their animals to a company that requires adherence to the Animal Welfare Instituteâs (AWI) Animal Welfare Standards. One of the key components of these standards is the prohibition of farrowing crates. While a pasture farrowing system is effective during most of the spring, summer, and fall, an alternative system is needed in order to farrow pigs in the winter for the naturally-raised pork market.
There are a variety of farrowing systems currently being used during cold weather to farrow pigs for the natural pork market. In general, all rely upon a primary heat source capable of maintaining a room temperature of at least 50ÂșF and auxiliary heat sources (heat lamps, bedding pack, confined space) to create a warmer microclimate for the young pigs. The use of adequate bedding and a design in harmony with the natural instincts of the hogs is key to the success of the example systems. A final critical consideration is a breeding program that insures sows in a particular room farrow within a short time frame (7 days or less) of each other.
With an increasing interest in winter farrowing to meet the naturally-raised pork market, Iowa State University embarked on a project funded by the Leopold Center to demonstrate alternative farrowing systems in cold weather. In 2002, a 62 ft 150,000 Btu/hr radiant heater tube was purchased and installed in an existing building on the Allee Demonstration Farm near Newell, IA. Modified A-frame farrowing huts designed for pasture farrowing were set-up in a double row down the center of the building. In the winter of 2002/2003, 36 litters were farrowed in this system. A total of 293 pigs were weaned for an average of 8.14 pigs/litter. Total energy expense for producing those 293 pigs was $4.94/pig weaned
A Hybrid Finite-Volume/Transported PDF Model for Simulations of Turbulent Flames on Vector Machines
Largeâscale hydroâclimatology of the terrestrial Arctic drainage system
The largeâscale hydroâclimatology of the terrestrial Arctic drainage system is examined, focusing on the period 1960 onward. Special attention is paid to the Ob, Yenisey, Lena, and Mackenzie watersheds, which provide the bulk of freshwater discharge to the Arctic Ocean. Station data are used to compile monthly gridded time series of gaugeâcorrected precipitation (P). Gridded time series of precipitation minus evapotranspiration (PâET) are calculated from the moisture flux convergence using NCEP reanalysis data. Estimates of ET are obtained as a residual. Runoff (R) is obtained from available discharge records. For longâterm waterâyear means, PâET for the Yenisey, Lena, and Mackenzie watersheds is 16â20% lower than the observed runoff. In the Ob watershed, the two values agree within 9%. Given the uncertainties in PâET, we consider the atmospheric and surface water budgets to be reasonably closed. Compared to the other three basins, the mean runoff ratio (R/P) is lower in the Ob watershed, consistent with the high fraction of annual precipitation lost through ET. All basins exhibit summer maxima in P and minima in PâET. Summer PâET in the Ob watershed is negative due to high ET rates. For large domains in northern Eurasia, about 25% of July precipitation is associated with the recycling of water vapor evapotranspirated within each domain. This points to a significant effect of the land surface on the hydrologic regime. Variability in P and PâET has generally clear associations with the regional atmospheric circulation. A strong link with the Urals trough is documented for the Ob. Relationships with indices of the Arctic Oscillation and other teleconnections are generally weak. Waterâyear time series of runoff and PâET are strongly correlated in the Lena watershed only, reflecting extensive permafrost. Coldâseason runoff has increased in the Yenisey and Lena watersheds. This is most pronounced in the Yenisey watershed, where runoff has also increased sharply in spring, decreased in summer, but has increased for the year as a whole. The mechanisms for these changes are not entirely clear. While they fundamentally relate to higher air temperatures, increased winter precipitation, and strong summer drying, we speculate links with changes in active layer thickness and thawing permafrost
Implicit threat vigilance among violent offenders diagnosed with antisocial personality disorder:The impact of ostracism and control threat
The present study investigated the role of control as a moderator in reaction to ostracism among male violent offenders diagnosed with ASPD (N = 33) compared to a control sample consisting of males from the normal population without a known history of violence, or diagnosis of ASPD, matched for age and educational level (N = 35). Participants played an altered version of the Cyberball game in which they could control the course of the game or not. The authors predicted and found that having control prior to ostracism would mitigate the effect of ostracism on implicit threat vigilance among violent offenders diagnosed with ASPD, but not among normal individuals. The results suggest that control needs are crucial in the typology of ASPD
- âŠ