Comparison of the physical and financial performance of organic dairy farming systems (OF0146)

This is the final report from Defra project OF0146 Two different systems of organic milk production were studied during the 1998-2002 period. The systems were established at the IGER Ty Gwyn organic dairy farm during the 1998/99 period. The systems were based either on achieving self-sufficiency in both home-grown forage and concentrate feeds or on the production of home-grown forage and the purchase of concentrate feeds. The data collected included recording the changes in the soil indices, level of crop production, crop quality, level of milk production, milk quality, animal health and herd reproductive performance of the two systems. The main attached report starts with a detailed executive summary. In the modelling work fifty-four different strategies for organic dairy production were evaluated. Performance data from three commercial organic dairy farms with different climatic conditions (Devon, Pembrokeshire and Shropshire) and cropping strategies (arable with all home-grown feed, home-grown forage only, home-grown forage + purchased concentrates) and also data from the two Ty Gwyn systems was inputted into three models (SAC Dairy Systems, SAC FeedByte, IRS OrgPlan) to evaluate the potential performance from different organic systems. The results produced a range of different options and rankings in relation to their potential financial performance and use of resources. The results from the data modelling predicted the best financial performance and utilisation of resources would be achieved by the establishment of an arable system on the Pembrokeshire farm. The lowest financial performance was predicted to be from the establishment of purchased concentrate systems on the Shropshire and Pembrokeshire farms, with the poorest utilisation of resource use indicators from both the establishment of a forage-only system on the Shropshire farm and purchased feed systems on both the Shropshire and Pembrokeshire farms. In relation to financial indicators the modelling work showed little difference between the two Ty Gwyn systems. The financial performance of Ty Gwyn was compared with ten commercial organic dairy farms, monitored during the 1998-2002 period. Of the ten commercial farms, four had been organic for a number of years, three were recently converted and three were in conversion. The net farm income of the Ty Gwyn SS system increased from 1998/99 to 1999/00 to a peak of £25,453 but then declined sharply following a fall in the price paid for organic milk to a loss of -£14,269 in 2001/02. In the Ty Gwyn PC system the net farm income increased to £24,122 in 2000/01 but then fell sharply to a loss of -£4,825 in 2001/02. The peak net farm incomes on the commercial farms were recorded in the 1999/00 period, with either a small loss (<-£50/ha) recorded on the well established farms or a small profit (<£50/ha) on the recently converted farms in 2001/02

The Collective Dynamics of Smoking in a Large Social Network

Based on repeated surveys of 12,067 closely interconnected people between 1971 and 2000, examines the extent to which smoking spreads socially and to which groups of smokers quit together, as well as trends in the number and social centrality of smokers

Friendship and Natural Selection

More than any other species, humans form social ties to individuals who are neither kin nor mates, and these ties tend to be with similar people. Here, we show that this similarity extends to genotypes. Across the whole genome, friends' genotypes at the SNP level tend to be positively correlated (homophilic); however, certain genotypes are negatively correlated (heterophilic). A focused gene set analysis suggests that some of the overall correlation can be explained by specific systems; for example, an olfactory gene set is homophilic and an immune system gene set is heterophilic. Finally, homophilic genotypes exhibit significantly higher measures of positive selection, suggesting that, on average, they may yield a synergistic fitness advantage that has been helping to drive recent human evolution

States and Federal Environmental Policy: A Hierarchical Linear Model of CAA And CWA Implementation

While designed and adopted at the federal level, the Clean Air Act (CAA) and Clean Water Act (CWA) rely on states for implementation. The result of this implementation framework is a disparity in environmental conditions across the nation. The objective of this research is to examine how the implementation stage of the policy process affects program outcomes. The findings indicate that the primary means of shaping program outcomes are the decision-making criterion and subsequent behavior of implementing officials, where their value based actions dictate service delivery. These decisions are, in turn, shaped by the context of the work, where organizations and the socio-political environment influence the basis for decision-making. These findings connect broader organizational and socio-political factors with program outcomes through an indirect relationship, rather than assume a direct relationship as previous authors have done. The findings explain a significant portion of the variance in both air and water program outcomes across the nation. This research indicates the importance of front-line operators in the implementation process, an issue that has been left-out of other work. These conclusions can be used to enhance performance management by practitioners, through a greater understanding of how organizations and individuals affect program outcomes. Finally, the theoretical framework and methodological techniques suggest that previous implementation research has failed to properly specify statistical models, which enhances the literature on the subject

MINORITY STRESS AND PHYSICAL HEALTH IN LESBIANS, GAYS, AND BISEXUALS: THE MEDIATING ROLE OF COPING SELF-EFFICACY

Mental health issues have been the primary focus of much of the health research concerning lesbian, gay, and bisexual (LGB) individuals over the previous decade. Studies have demonstrated that LGB individuals experience psychological distress due to prejudice and discrimination (Lewis, Derlega, Berndt, Morris, & Rose, 2002; Meyer, Schwartz, & Frost, 2008; Rostosky, Riggle, Horne, & Miller, 2009). Health researchers have not given the physical health of LGB individuals the same level of attention (Dibble, Eliason, & Christiansen, 2007). The Gay and Lesbian Medical Association (GLMA; 2001) asserted that little was known about LGB physical health disparities and called for more research in this area. However, the Institute of Medicine (2011) showed that comparatively little is known about LGB physical health. There is growing evidence from population-based studies that LGB individuals may be at greater risk than heterosexuals for many physical health conditions (Cochran & Mays, 2007; Dilley, Simmons, Boysun, Pizacani, & Stark, 2010; Sandfort, Bakker, Schellevis, & Vanwesenbeeck, 2009). Many of these studies (e.g., Cochran & Mays, 2007; Sandfort et al., 2009) referred to the stigmatization of LGB individuals; however, none of these studies empirically explored the relation between stigmatization and physical health in LGB individuals. The goal of this study was to test the utility of Meyer’s (2003) minority stress model as a means of explaining the physical health of LGB individuals in the context of a heterosexist society. This study investigated empirical questions about minority stress factors, physical health, and coping self-efficacy (CSE) of LGB individuals. Five-hundred fifteen LGBidentified adult participants (n = 222 women and n = 293 men) were recruited to complete a web-based survey. Participants were primarily recruited through online forums sponsored by LGB-affirming organizations. Results indicated that higher expectations of rejection based on sexual identity, internalized homonegativity, and LGBbased victimization predicted greater reported physical symptoms severity (PSS). CSE fully mediated the relation between expectation of rejection and physical symptom severity and internalized homonegativity and PSS. CSE partially mediated the relation between victimization and PSS. The document proposed several clinical and systemic interventions that may benefit physical health in LGB individuals

An empirical model for strategic network foundation

We develop and analyze a tractable empirical model for strategic network formation that can be estimated with data from a single network at a single point in time. We model the network formation as a sequential process where in each period a single randomly selected pair of agents has the opportunity to form a link. Conditional on such an opportunity, a link will be formed if both agents view the link as beneficial to them. They base their decision on their own characateristics, the characteristics of the potential partner, and on features of the current state of the network, such as whether the the two potential partners already have friends in common. A key assumption is that agents do not take into account possible future changes to the network. This assumption avoids complications with the presence of multiple equilibria, and also greatly simplifies the computational burden of anlyzing these models. We use Bayesian markov-chain-monte-carlo methods to obtain draws from the posterior distribution of interest. We apply our methods to a social network of 669 high school students, with, on average, 4.6 friends. We then use the model to evaluate the effect of an alternative assignment to classes on the topology of the network.

Textures in komatiites and variolitic basalts.

Komatiites and variolitic basalts are widespread in Archean volcanic sequences. Spinifex is a spectacular bladed olivine or pyroxene texture that characterizes komatiite, a rock almost exclusively restricted to the Archean; varioles are cm-scale leucocratic globular structures abundant in many Archean basalts. These striking textures provide valuable information about conditions during emplacement of the host magmas, particularly about how the magmas crystallized. Many komatiite flows have spinifex textures consisting of arrays of numerous subparallel olivine blades that extend 10's of cm to m's from the flow tops. The habit of the strongly anisotropic crystals is suggestive of fast cooling near the flow margin, yet the crystals form deep within the flows. The large temperature difference between solidus and liquidus of komatiites provides a partial explanation for their formation. In addition, the crystals are sharp-tipped and aligned so that their fastest growing faces were normal to the cooling contacts, suggesting that they grew in a strong chemical-potential gradient, in part created by the crystals themselves, as they modified the composition and temperature of the liquid from which they crystallized

Dynamic Spread of Happiness in a Large Social Network: Longitudinal Analysis Over 20 Years in the Framingham Heart Study

Objectives: To evaluate whether happiness can spread from person to person and whether niches of happiness form within social networks. Design: Longitudinal social network analysis. Setting: Framingham Heart Study social network. Participants: 4739 individuals followed from 1983 to 2003. Main outcome measures: Happiness measured with validated four item scale; broad array of attributes of social networks and diverse social ties. Results: Clusters of happy and unhappy people are visible in the network, and the relationship between people’s happiness extends up to three degrees of separation (for example, to the friends of one’s friends’ friends). People who are surrounded by many happy people and those who are central in the network are more likely to become happy in the future. Longitudinal statistical models suggest that clusters of happiness result from the spread of happiness and not just a tendency for people to associate with similar individuals. A friend who lives within a mile (about 1.6 km)and who becomes happy increases the probability that a person is happy by 25% (95% confidence interval 1% to 57%). Similar effects are seen in coresident spouses (8%, 0.2% to 16%), siblings who live within a mile (14%, 1% to 28%), and next door neighbours (34%, 7% to 70%). Effects are not seen between coworkers. The effect decays with time and with geographical separation. Conclusions: People’s happiness depends on the happiness of others with whom they are connected. This provides further justification for seeing happiness, like health, as a collective phenomenon.Sociolog