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Weak Link (weak + link)
Selected AbstractsA Quantitative Conservation Approach for the Endangered Butterfly Maculinea alconCONSERVATION BIOLOGY, Issue 2 2004MICHIEL F. WallisDeVries The quality and size of habitat patches and their isolation from other patches are the main parameters for an assessment of population persistence, but translating persistence probabilities into practical measures is still a weak link in conservation management. I provide a quantitative conservation approach for the endangered myrmecophilous butterfly Maculinea alcon in the Netherlands. All 127 colonies known on heathland since 1990 were investigated for patch quality, size, and isolation. I assessed habitat quality in three 10 × 10 m plots for most colonies. Site occupancy in 1998,1999 was only 56%. Occupancy was best explained by a logistic regression including patch area, host ant presence, host plant abundance, overall heathland area, and connectivity between sites ( R2= 0.410, p < 0.0001); it correctly classified the occupied or vacant status for 82% of the sites. Connectivity contributed only 3.6% to the total explained variation of site occupancy, indicating that habitat characteristics were more important than isolation in determining population persistence at the examined scale level (>500 m). Grazing and sod cutting had a beneficial impact, but in combination these practices proved detrimental. Hydrological measures to prevent drainage were also associated with lowered occupancy. I used the different components in the logistic regression to formulate objective management recommendations. These consisted of sod cutting, reduction of management intensity, enlargement of habitat, or combinations of these recommendations. The results highlight the importance of careful management when site quality is determined by multiple factors. The quantitative conservation approach followed here can be fruitfully extended to other endangered species, provided enough is known about their ecological requirements and how management actions affect them. Resumen:,La preservación de fragmentos individuales es extremadamente importante para especies en peligro con capacidad de dispersión limitada. La calidad y tamaño de los fragmentos de hábitat y su aislamiento de otros fragmentos son los parámetros principales para la evaluación de la persistencia de la población, pero la traducción de probabilidades de persistencia en medidas prácticas aun es un eslabón débil en la gestión de conservación. Proporciono un método cuantitativo de conservación para la mariposa mirmecófila Maculinea alcon en peligro en Holanda. Se investigó a las 127 colonias conocidas en brezales desde 1990 para calidad, tamaño y aislamiento del fragmento. Evalué la calidad del hábitat en tres parcelas de 10 × 10 m en la mayoría de las colonias. La ocupación de sitios en 1998-1999 fue sólo 56%. La ocupación fue mejor explicada por regresión logística incluyendo la superficie del fragmento, presencia de hormigas huésped, abundancia de plantas huésped, superficie total del brezal y conectividad entre sitios ( R2= 0.410, p < 0.0001); clasificó el estatus de ocupado o vacante en 82% de los sitios. La conectividad contribuyó con solo 36% de la variación total de sitio de ocupación, lo que indica que las características de hábitat fueron más importantes que el aislamiento en la determinación de la persistencia de la población en el nivel de escala examinado (>500 m). El pastoreo y el corte de pasto tuvieron un impacto benéfico pero combinadas, estas prácticas fueron perjudiciales. Obras hidrológicas para prevenir la desecación también se asociaron con una disminución en la ocupación. Utilicé los diferentes componentes de la regresión logística para formular recomendaciones objetivas de gestión. Estas incluyeron el corte de pasto, reducción en la intensidad de manejo, aumento de hábitat o combinaciones de estas recomendaciones. Los resultados resaltan la importancia de la gestión cuidadosa cuando la calidad del sitio está determinada por múltiples factores. El método cuantitativo de preservación utilizado puede ser extendido exitosamente a otras especies en peligro, siempre que sean suficientemente conocidos sus requerimientos ecológicos y la forma en que le afectan las acciones de manejo. [source] More Peace for Less Money: Measurement and Accountability in the Swedish Armed ForcesFINANCIAL ACCOUNTABILITY & MANAGEMENT, Issue 4 2005Bino Catasús Studies of measurement and accountability are leading public sector transformation. By examining military work, this paper addresses the relationship between measurements and accountability by highlighting the measurements. Evidence was gathered from documents, political statements and field research. Several layers of accountability systems were found in the organisation. The principal can be the weak link in an accountability relationship if the measurement agenda is in the hands of the agent. The problems seem to go beyond performance and output, and a more fundamental question is challenging the public sector: `Are we doing the right things?' Or an even more dramatic existential question arises: `Why do we exist?' [source] Temperature drop analysis of the thruster in a space cryogenic environmentHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 2 2007Ze-Juan Xiao Abstract Based on the conservation of energy, a coupling heat-transfer physical model and a set of mathematical equations are put forward to calculate the main components of the thruster, including the capillary injection tube, the aggregate organ, the injection plate, and the bracket when they are exposed to a space cryogenic environment. The typical temperature drop course of a 10N monopropellant thruster has been calculated by this computational model. The calculation results agree well with test data in a vacuum cryogenic simulation experiment performed on the ground. The temperature of the injection tube provides the thermal boundary conditions for the propellant temperature drop calculation while flowing through it. This provided the criterion to judge whether the propellant freezes or not. The upper stage has no air conditioning, so the injection tube is a weak link for the cryogenic reliability work of the thruster. This is considered one of the most important areas of the whole for reliability research. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(2): 85,95, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20144 [source] Achieving education for all: how much does money matter?JOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 2 2006Samer Al-Samarrai This paper explores the extent to which differences in the resources allocated to education explain differences in educational access and performance across countries. Cross-country regression analysis shows that the link between educational access and performance and public education expenditure is weak. The paper suggests that levels of household spending, the effectiveness of the public expenditure management system and the composition of public education spending are important factors explaining this weak link. The results imply that the achievement of the education millennium development goals will require more than just increases in expenditure on primary education. This does not imply that resources are unnecessary, but that increasing resources alone is unlikely to be sufficient. The composition of resources and institutions that govern the use of these resources play a central role in translating resources into better schooling outcomes. A stronger focus on these aspects of education systems will be required if the Millennium Development Goals in education are to be achieved. Copyright © 2005 John Wiley & Sons, Ltd. [source] Avoiding the weak linkMETEORITICS & PLANETARY SCIENCE, Issue 1 2000William K. Hartmann Associate Editor [source] Job control, substantive complexity, and risk for low birth weight and preterm delivery: An analysis from a state birth registryAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 9 2007John D. Meyer MD Abstract Background Indices of job strain have demonstrated a variable relationship to low birth weight (LBW) and prematurity, with conflicting study results. This study sought to examine the associations of psychosocial work environment characteristics with adverse pregnancy outcomes using and comparing the demand-control model and job attributes derived from the O*NET. Methods Job characteristics were imputed to maternal occupation recorded in the 2000 Connecticut state birth registry for 26,408 singleton births, using scores for psychological job demands, control, and physical demands derived from the Job Content Questionnaire, and for substantive complexity of work and physical demands using variables derived from O*NET job attributes. Odds ratios for LBW and preterm delivery were estimated while controlling for relevant covariates. Results High psychological demands were not associated with pregnancy outcomes, while high physical demand scores from the O*NET were associated with LBW. Associations of term- and all-LBW with both low control and low substantive complexity were attenuated by adjustment for educational and demographic covariates. A gradient with lower scores was seen for term LBW and substantive complexity, and for prematurity and control. Both constructs were correlated with maternal education. Conclusions These results suggest that low maternal job control and substantive complexity may be modestly associated with LBW and, to a lesser extent, prematurity. A greater association with control may explain why a weak link of birth outcomes to high-strain work has been noted in past studies. Observed associations with occupational are reduced after adjustment for relevant confounding variables, in particular educational level and race/ethnicity. Am. J. Ind. Med. 50:664,675, 2007. © 2007 Wiley-Liss, Inc. [source] Senior Management Support in the New Product Development ProcessCREATIVITY AND INNOVATION MANAGEMENT, Issue 4 2001Jorge Gomes This paper studies the relationship between senior management support to new product development activities by means of a quantitative and qualitative analysis of questionnaire and interview data collected in the United Kingdom and the Netherlands. The quantitative analysis showed that there is a small to medium association between senior management support to new product development and project performance in the dimensions of time, cost, and end product quality. The qualitative analysis suggests that these weak links could be explained by separating the influence of senior management support on new product development activities into direct and indirect effects. Direct effects include issues such as the use of multifunctional senior teams and process champions, whereas indirect effects include issues such as organization mission and goals, and learning and knowledge management systems. [source] Effects of heterogeneous interaction strengths on food web complexityOIKOS, Issue 3 2008Josep L. Garcia-Domingo Using a bioenergetic model we show that the pattern of foraging preferences greatly determines the complexity of the resulting food webs. By complexity we refer to the degree of richness of food-web architecture, measured in terms of some topological indicators (number of persistent species and links, connectance, link density, number of trophic levels, and frequency of weak links). The poorest food-web architecture is found for a mean-field scenario where all foraging preferences are assumed to be the same. Richer food webs appear when foraging preferences depend on the trophic position of species. Food-web complexity increases with the number of basal species. We also find a strong correlation between the complexity of a trophic module and the complexity of entire food webs with the same pattern of foraging preferences. [source] | |||||||||||||