Evolving fracture patterns: columnar joints, mud cracks, and polygonal terrain

When cracks form in a thin contracting layer, they sequentially break the layer into smaller and smaller pieces. A rectilinear crack pattern encodes information about the order of crack formation, as later cracks tend to intersect with earlier cracks at right angles. In a hexagonal pattern, in contrast, the angles between all cracks at a vertex are near 120$^\circ$. However, hexagonal crack patterns are typically only seen when a crack network opens and heals repeatedly, in a thin layer, or advances by many intermittent steps into a thick layer. Here it is shown how both types of pattern can arise from identical forces, and how a rectilinear crack pattern evolves towards a hexagonal one. Such an evolution is expected when cracks undergo many opening cycles, where the cracks in any cycle are guided by the positions of cracks in the previous cycle, but when they can slightly vary their position, and order of opening. The general features of this evolution are outlined, and compared to a review of the specific patterns of contraction cracks in dried mud, polygonal terrain, columnar joints, and eroding gypsum-sand cementsComment: 19 pages, 9 figures, accepted for publication in Phil. Trans. R. Soc. A; theme issue on Geophysical Pattern Formation (to appear 2013

Pattern formation in the geosciences

Pattern formation is a natural property of nonlinear and non-equilibrium dynamical systems. Geophysical examples of such systems span practically all observable length scales, from rhythmic banding of chemical species within a single mineral crystal, to the morphology of cusps and spits along hundreds of kilometres of coastlines. This article briefly introduces the general principles of pattern formation and argues how they can be applied to open problems in the Earth sciences. Particular examples are then discussed, which summarize the contents of the rest of this Theme Issue

Palm Oil: The Hidden Costs

ENSC 230. Energy and the Environment: Economics and Policy 12/7/2017 Palm Oil: The Hidden Costs Lurking behind your soaps, cosmetics, pantry groceries, and household cleaning supplies is a product killing endangered species in Southeast Asia. This same product is destroying the survival mechanisms for local communities in Southeast Asia while pumping large amounts of greenhouse gas emissions into the atmosphere. To keep its identity hidden, it uses over twenty different names on ingredient labels. What is this product? Palm oil. Palm oil is the most widely used vegetable oil in the world and increased demand for palm oil in our various supermarket products has doubled production in the recent decade (Vijay, 2016). Palm oil is not all bad. Palm oil is a productive crop, producing up to ten times more than any other vegetable oil crop per hectare (Tunnicliffe, 2013). This same product has the potential to provide renewable energy utilizing the production by-product for methane gas energy as well as biofuels in the local community (Cheau, 2017). Additionally, with the health risks of trans fats, palm oil is an attractive alternative as trans fat free oil. However, the issue is not the use of palm oil and its by-products, but the growth in production as palm oil thrives in areas currently covered in forests. Consumption of palm oil has grown fourfold since 1990. The trajectory of this growth is expected to continue with production tripling by 2050. The growing demand generates tens of billions of dollars in revenue and employs millions in Southeast Asian countries. The story is that conserving the rainforests from palm oil production puts this economy at risk, but only because the current formula does not account for the externalities of deforestation. Rainforests in Southeast Asia are a critical source of food, medicines, and materials for local communities. Many local communities have been removed from lands with palm oil production capabilities and often must work at the plantations for low wages or move to urban slums. This is an externality not accounted for in the current economic formula. Tropical rainforests regulate weather patterns and act as buffers from storms. They maintain watershed and river health for agriculture as well as provide habitat for endangered species. This is an externality not accounted for in the current economic formula. The conversion from rainforest to plantation had led to forest fires polluting the air of residents, closing schools temporarily, and suspected of causing numerous respiratory infections (Tabuchi, 2016). This is an externality not accounted for in the current economic formula. Lastly, deforestation emits massive amounts of greenhouse gases as these rainforests have served as carbon sinks for centuries. According to NASA, tropical rainforest deforestation accounts for 10% of annual anthropogenic carbon emissions (Tunnicliffe, 2013). This is an externality not accounted for in the current economic formula. Overall, the economic decision to convert rainforests into plantations seems attractive when the externalities are pushed on local communities instead of plantation companies. This status quo is dangerous because as yield capabilities and technology in palm oil production improve, it encourages more land to be converted as well as expands production into nations with vulnerable forest habitats. For example, with most suitable land for oil palm in Southeast Asia converted many palm oil companies are now investing in Africa (Carrasco, 2014). Currently, only 2% to 7% of oil palm plantations in Africa are coming from areas that were previously forests; however, in Southeast Asia this is 45% and 31% in South America. These percentages cannot occur in Africa as Africa contains a high density of species at risk of extinction (Vijay, 2016). Coalitions exist working towards sustainable palm oil; however, progress is slow. According to the Roundtable of Sustainable Palm Oil, only 20% of global palm oil production is sustainable. With the projected demand growth for palm oil, I do not see 20% being enough. Leaving this commitment as voluntary will not be enough. The habitat, local communities, and endangered animals do not have decades to solve this problem. Therefore, palm oil importing nations need to commit to only sustainable palm oil. Goods containing palm oil need to be required to have federally mandated labeling on whether the goods were produced sustainability or unsustainability. This labeling would allow consumers to become educated on how their products are made and make the determination of what goods to purchase based on the new information. Allowing three years before mandatory labeling takes affect would allow companies sufficient time to analyze and change their supply chain without economic challenges ensuing in order to avoid consumer push back if products were previously made with unsustainably produced palm oil. We’ve demanded sustainable practices in the form of labeling from foreign nations in the past and succeeded. If we can do it once, we can do it again

Heat Detection in Beef Cattle

New techniques and cheaper products for estrous synchronization of beef cattle have increased the use of this management practice for both commercial and seedstock producers. Hand-in-hand with synchronization comes the need to accurately detect heat in cows and heifers. Heat detection is simply looking for changes in a cow\u27s behavior caused by her coming into, or being in, standing heat. The most definite behavioral change is standing firmly while mounted, with the mounting/riding process repeated several times

Tips to Help Make Dog Training Easier

Socialize your puppy. Don‟t just get a pup and put them in a kennel or put them in a stall in a barn and expect them to come out a year later and have someone be able to train your dog. Let a puppy be a puppy. Lots of contact with the family, and in my personal opinion, there is nothing better than having a puppy grow up with kids

Efficacy of Differential Negative Reinforcement of Alternative Behaviors to Improve Reading Comprehension

This multiple baseline across participants design answered the question: is a differential negative reinforcement of alternative (DNRA) behaviors effective in improving reading comprehension accuracy. Students with emotional/behavioral disorders (E/BD) often display challenging behaviors during academic lessons, typically to escape tasks they perceive to be aversive or those for which they lack sufficient academic achievement. Several function-based interventions have been used to address misbehavior due to this function such as providing easier work or asking for a break. However, differential negative reinforcement of alternative behavior (DNRA) is an intervention that directly addresses escape from work for which students possess the requisite skills but find the activity unpleasant. While a few studies on DNRA interventions have addressed academic concerns during math activities, the current study extended the extant research in two important ways. First, it examined effectiveness to reading comprehension. Second, most DNRA intervention build in breaks contingent upon obtaining certain accuracy over small sections of the assignment. However, in the present study, participants were able to escape doing a second worksheet contingent upon a performance standard. This approach is more beneficial because it does not waste academic time through the use of multiple breaks. Three fourth graders participated in the study that used a multiple baseline design across participants. Results indicated improvements for all participants across all conditions. Specifically, all participants improved their reading scores on maze tasks and earned negative reinforcement in 89.3% of their intervention sessions. Results are discussed in terms of implications for practice and areas for future research. Advisor: John W. Maa

Stop, Meditate, and Listen: A Treatment Modality for Iraqi Refugees with Depression

Purposes: To implement a mindfulness meditation program with Arabic speaking clients as an adjunctive treatment of depression Background: Depression rates among Iraqi refugees are between 28.3 and 75% compared to 8.6% in the general population (Slewa-Younan, Guajardo, Heriseanu, & Hasan, 2015). Treatment options are limited at Neighborhood Healthcare in El Cajon due to budget limitations, cultural beliefs and language barriers, among other reasons. Individual therapy is intended to be a brief intervention due to limited staffing. Many middle eastern refugees decline group therapy due to stigma surrounding mental health treatment and concerns about privacy. Even though traditional treatment options are effective in many cases, there is also a gap in care. Numerous patients continue to exhibit significant depression with the current interventions in place. Mindfulness interventions are shown to have a medium to large effect size for the treatment of depression. In addition, mindfulness interventions are easy to teach and can be practiced by the patient independently. Methods:The nurse practitioner met with six clients for individual sessions in order to teach clients how to meditate. Inclusion criteria are a Patient Health Questionnaire 9 (PHQ-9) score greater than 10 and primary language of Arabic. The nurse practitioner instructed clients regarding guided meditation and mindfulness. The patients had access to meditation tracks and were calls by clinic staff to encourage practice at home during the initiation of treatment. Quality of Life Scores (QoL) were measured at the first and last session. PHQ-9 scores were measured at all sessions. Outcomes Achieved: Three of six patients completed the program with partial adherence to treatment. Patients experiences a 9% to 58% increase in QoL. One patient experienced an improvement in PHQ-9. Patients reports positive outcomes subjectively and planned to continue meditating. Conclusions: Meditation is a treatment option already widely used in western cultures. Although meditative practices are used in some religious practices, most Middle Eastern patient have little exposure to meditation. Recently, resources for meditation in Arabic were developed in Australia and have already shown to be effective in the treatment of depression for people from the Middle (East South Eastern Sydney Local Health District, 2017)

The Wordsworthian Inheritance of Melville's Poetics

It has become commonplace among both Melville and Wordsworth critics to recognize a basic ambiguity or contradictoriness in each artist's writing. In this project, I find the roots of that tension in each artist's concept of the imagination and the process of poetic creation. More importantly, I find that Melville's concept of art, as reflected in his magnum opus Moby-Dick and substantiated in his poetry, reveals a basic affinity with Wordsworth's Imagination.Specifically, my project traces the lingering elements of Wordsworth's concept of the poetic process in Melville's writing, particularly focusing on two important and complex relationships in that creative process: 1) the implicit paradox of activity and passivity in a poetics that assumes at its heart inspiration, and Wordsworth's particular devotion to preserving rather than reconciling that paradox; and 2) the role of society in a creative process that seeks to privilege individual genius while ensuring the social efficacy of the workings of that genius. Here emerging at the center of my study—not surprisingly—is an engagement with The Whale, in which I offer a reading of Moby-Dick as a text that, at least in part, is occupied with the process and position of the artist.In paying particular attention to the evidence of a close relationship with Wordsworth in Melville's conception of art, I am not as interested in the question of literary influence as I am in demonstrating that Melville struggled with many of the same questions regarding art and creation that are evident in Wordsworth's own writing. In seeking connections between Melville's literature, particularly his poetry, and Wordsworth, my transcontinental project reveals a concern with the role of the artist in society—a question of the responsibility of the artist that is importantly enduring, despite the years and distance between the writers