Cell proliferation and differentiation kinetics during spermatogenesis in Hydra carnea

Spermatogenesis inHydra carnea was investigated. The cell proliferation and differentiation kinetics of intermediates in the spermatogenesis pathway were determined, using quantitative determinations of cell abundance, pulse and continuous labelling with3H-thymidine and nuclear DNA measurements. Testes develop in the ectoderm of male hydra as a result of interstitial cell proliferation. Gonial stem cells and proliferating spermatogonia have cell cycles of 28 h and 22 h, respectively. Stem cells undergo four, five or six cell divisions prior to meiosis which includes a premeiotic S+G2 phase of 20 h followed by a long meiotic prophase (22 h). Spermatid differentiation requires 12–29 h. When they first appear, testes contain only proliferating spermatogonia; meiotic and postmeiotic cells appear after 2 and 3 days, respectively and release of mature sperm begins after 4 days. Mature testes produce about 27,000 sperm per day over a period of 4–6 days: about 220 gonial stem cells per testis are required to support this level of sperm differentiation. Further results indicate that somatic (e.g. nematocyte) differentiation does not occur in testes although it continues normally in ectodermal tissue outside testes. Our results support the hypothesis that spermatogenesis is controlled locally in regions of the ectoderm where testes develop

Exploring Beginning Latino Farmers and Ranchers' Willingness to Become Involved in Community Activities in Rural Missouri

Presentation made at Latinos in the Heartland (13th : 2015 : Columbia, Mo.) and published in the annual conference proceedings.In 2013, we conducted two workshop series, each consisting of 10 sessions, focused on how to improve financial capacity of agribusiness and to gain access to community resources. As part of the workshops, eighteen Latino farmers and ranchers in Southwest Missouri completed a survey that analyzed their disposition towards becoming involved in community activities over the upcoming six months. The willingness of the Latino farmers and ranchers to become involved in community activities was explored across five indicators: 1. to be more engaged in community leadership roles, 2. to form new connections in the community, 3. to display more tolerance when working with others, 4. to develop a community action plan, and 5. to implement a community project. A total of 140 answers to each indicator were collected from participants and were analyzed using symmetric responses, where 1 was coded as "not willing," 2 was coded as "reluctant," 3 as "neutral," 4 as "moderate willing," and 5 as "very willing." Participants' responses to each of those five indicators showed that many (46%, 43%, 51%, 53% and 48%) beginning farmers and ranchers were "very willing" to involve themselves with community projects and activities during the upcoming six months. The willingness of participants to become involved in community activities helped us to know their predisposition to integrate and assimilate into the communities where they lived. It is argued that Latino immigrants have trouble assimilating into mainstream US culture (Huntington, 2004), and those who do assimilate, belong to a cluster with the following characteristics: spatial concentration, high incomes, intermarriage, English fluency and high levels of embeddedness in Anglo-social contexts (South et al. 2005, Waters & Jimenez, 2005). The predisposition to participate in community activities is positively related with Waters and Jimenez's perception (2005) that US communities have evolved in absorbing new immigrants and continual immigrant replenishment makes assimilation less visible. Other factors influencing positive integration and assimilation may be attributed to the population size of that immigrant group in the community and the population size of the rural community where they immigrated. A multistate conference about integration of immigrants Proceedings of the 13th Annual Conference Latinos in the Heartland: Growing Together in New Destination Areas www.cambio.missouri.edu/Library/ Key words: beginning Latino farmers and ranchers, immigrant integration, rural communities

The Timing of Managerial Responses to Fiscal Stress

17 USC 105 interim-entered record; under temporary embargo.Using 34 years of data from Florida counties, we examine the effect of multiple fiscal stressors on expenditures over time to test theoretical propositions in Charles Levine's seminal study on cutback management. We demonstrate support for Levine's stages model and his claims on linkages between the causes of fiscal stress and managerial responses. Specifically, unemployment levels produce differential effects by service area (e.g., human services bear the most significant share of the reductions), especially in relation to the persistence of the stressor. We cannot support the stages model with other stressor measures. We expand the literature to include county governments, enhancing the contemporary literature on local government fiscal stress.U.S. Government affiliation is unstated in article text

Building Terrestrial Planets

This paper reviews our current understanding of terrestrial planets formation. The focus is on computer simulations of the dynamical aspects of the accretion process. Throughout the chapter, we combine the results of these theoretical models with geochemical, cosmochemical and chronological constraints, in order to outline a comprehensive scenario of the early evolution of our Solar System. Given that the giant planets formed first in the protoplanetary disk, we stress the sensitive dependence of the terrestrial planet accretion process on the orbital architecture of the giant planets and on their evolution. This suggests a great diversity among the terrestrial planets populations in extrasolar systems. Issues such as the cause for the different masses and accretion timescales between Mars and the Earth and the origin of water (and other volatiles) on our planet are discussed at depth

Evaluating the road works and street works management permit scheme in Derby, UK

Road works (highway works) and street works (utility works) activities are vital for society to travel, enjoy amenities, and to access essential services such as water, electricity, gas and telecommunications. However, road works and street works can be disruptive, inconvenient and have high social costs. The Permit scheme is a relatively new management regime which seeks to reduce the disruption caused by highway excavations by giving English Street Authorities greater control of works in their areas. The Derby Permit scheme commenced on October 2013. This research aims to understand whether the adoption of the Permit scheme has resulted in any change to the city’s road works and street works landscape. A time series model using an intervention variable was run. 61 months of average works duration data was analysed along with several independent variables including daylight hours, economic activity and precipitation. The results showed that the Permit scheme had a positive effect on Derby by reducing the overall average duration of works by a third of a day. This is a 10% reduction overall, being equal to 8434 days per year, and in monetary terms equivalent to saving £769,048/$1,179,777 in societal costs per annum. This research is significant as it provides impact information for policy makers and practitioners on a relatively new type of scheme, and it is original, in that this is the first time that an intervention analysis approach has been applied to this area of public policy

Process mapping for road works planning and coordination

Purpose Diminishing local government budgets and the need to reduce highway works activities necessitate cost effective and efficient processes. This paper investigates streamlining road works administrative processes to enhance coordinated working at Derby City Council. Design/methodology/approach Case study research of a local authority was undertaken using Business Process Mapping. Specifically, Swimlane analysis enabled re-engineering of business processes from design stage, to works permit issuance. Process improvement recommendations were validated by nine industry experts through a focus group and semi-structured interviews. A logic map was developed for transferability to other Councils, identifying key attributes for a successful administrative road works management process. Findings Research revealed inherent silo working and processes built around fragmented IT systems creating process inefficiency. Validation found numerous practices and management styles were culturally embedded and common across Councils. Peer reviewed recommendations are made to improve working practices, including improving IT systems, removing process bottlenecks, and training staff. Research implications Whilst road works management policy is generally under-researched, it’s strategic and negative impacts are widely acknowledged. This study highlights the day-to-day operational problems which are interconnected to the strategic impact, bridging an important gap in knowledge, as well as adding to Business Process Re-engineering literature. Originality/novelty The research adds to a limited of body of road works management policy research, and also presents a high-level logic map for Councils to adopt as appropriate

Stakeholder perspectives of street works management in England

It is widely recognised that street works are disruptive, have high social costs and are deleterious to highway structures. Notwithstanding this, utility works are critical so that society can enjoy the amenities of a modern world. In striking this balance, this study investigates the policy landscape of street works management in England to gain an insight into stakeholder perspectives of the industry. Semi-structured interviews with industry stakeholders have helped to identify the complexity of the industry and revealed that a number of issues compromise effective street works management. Principal problems include Street Authorities failing to take enough ownership of the coordination process, highway legislation not encouraging joint working due to inherent challenges arising from reinstatement guarantees, and entrenched attitudes and adversarial practices in the construction industry encouraging silo working. Key recommendations include amending highway legislation to support and recognise multi-agency working and Street Authorities undertaking reinstatements on behalf of undertakers to help reduce fragmentation and discharge undertakers of onerous guarantees which contribute to silo working

Street work policy in England, UK: insights from stakeholders

Road works and street works can be highly disruptive, expensive and deleterious to highway structures and infrastructure planning, yet these activities must take place if modern societies are to continue to function. In helping to strike this balance, this study investigates the public policy landscape of highway excavation management in England. Semi-structured interviews with industry stakeholders highlighted the complexity of the industry and revealed that a number of issues compromise effective management. Principal problems included Street Authorities failing to take enough ownership of the coordination process, highway legislation not encouraging joint working due to inherent challenges arising from reinstatement guarantees, and entrenched attitudes and adversarial practices in the construction industry encouraging silo working. Key recommendations include amending highway legislation to support and recognise multi-agency working and Street Authorities undertaking reinstatements on behalf of undertakers, thus helping to reduce fragmentation and discharge undertakers of onerous guarantees which contribute to silo working

Time series analysis of local authority policy interventions on highway works durations

Highway works are highly inconvenient and disruptive for society. Accordingly, four highway policy interventions were investigated in Derby, England for potential corresponding reductions in highway works durations. Time series analysis tested the durational impacts on Highway Authority (HA) and utility industry led works. Modelling results demonstrated that a highway works management Permit Scheme (chargeable) reduced utility works durations by 5.4%; (727 work days annually). Conversely, three conflated interventions comprising: the Permit Scheme (cost-free to HAs), JCB Pothole Master deployment, and the construction direct labour organisation (DLO), did not make any statistically significant difference on HA works durations; however, introducing an automated works order management system (WOMS) reduced HA works duration by 34% (6519 work days annually). Key findings are that chargeable Permit Scheme charges can create impetus for change as demonstrated by the utility industry. Furthermore, WOMS revealed that back office efficiency can lead to on-site efficiency in works execution