Novel tools to study cell-ECM interactions, cell adhesion dynamics and migration.

Integrin-mediated cell adhesion is essential for cell migration, mechanotransduction and tissue integrity. In vivo, these processes are regulated by complex physicochemical signals from the extracellular matrix (ECM). These nuanced cues, including molecular composition, rigidity and topology, call for sophisticated systems to faithfully explore cell behaviour. Here, we discuss recent methodological advances in cell-ECM adhesion research and compile a toolbox of techniques that we expect to shape this field in future. We outline methodological breakthroughs facilitating the transition from rigid 2D substrates to more complex and dynamic 3D systems, as well as advances in super-resolution imaging for an in-depth understanding of adhesion nanostructure. Selected methods are exemplified with relevant biological findings to underscore their applicability in cell adhesion research. We expect this new "toolbox" of methods will allow for a closer approximation of in vitro experimental setups to in vivo conditions, providing deeper insights into physiological and pathophysiological processes associated with cell-ECM adhesion.

Economic returns and the perceived obstacles to adopting active management in the forest-grassland transition ecoregion in south-central USA.

Forest-grassland ecotones are a mosaic of grassland, savanna, and upland forest. As such, landowners may have opportunities to choose to manage their lands for multiple objectives. We estimated the economic returns from managing forest and rangeland in southeastern Oklahoma, USA to produce different combinations of timber, cattle forage, and white-tailed deer (Odocoileus virginianus Zimmermann) browse for a 40-year period. We further conducted a survey to understand landowner perceptions of obstacles to adopting active management that involve timber harvest and prescribed fire. The highest net return was obtained from the treatment with harvested timber that was burned every four years (uneven-aged woodland/forest) because it had the greatest gross return from a combination of timber (46%), cattle forage (42%), and deer browse (11%). The return from this treatment was greater than that for managed for timber only (closed-canopy forest) or prioritizing cattle and deer (savanna). Survey results suggested that landowners were aware of the benefits of active management but that the majority (66%) considered cost a major obstacle in the management of their forest or rangeland. In particular, women forestland owners and older landowners considered cost an obstacle. Our findings advocate integrated timber, cattle, and deer management as the best economic strategy within the forest-grassland ecotone and for targeted outreach and landowner education related to the benefits of active management.

Intentions of Landowners towards Active Management of Ecosystem for Deer Habitat.

Active management such as prescribed fire and thinning can restore savanna and prairie ecosystem to maintain a full suite of ecosystem services and create suitable habitat for wildlife species such as white-tailed deer (Odocoileus virginianus). Active management comes with the cost of management and acceptance of management tools. The south-central transitional ecoregion of the USA, which otherwise was a mixture of forest, savanna, and tallgrass prairie, is increasing in woody plant dominance due to the exclusion of fire and other anthropogenic factors. Deer hunting is a vital source of revenue generation to offset the landowner's management cost in the region. We studied Oklahoma landowners' perceptions regarding active and sustainable management of forest and rangeland for deer habitat using two established theories of reasoned action and planned behavior as well as expanded theories adding moral norms. We analyzed mailed survey data using structural equation modeling. We found that subjective norms and perceived behavior control significantly affected deer hunting intention when moral norms were introduced into the model. Attitudes independently significantly affected intentions of deer hunting but have negative relations with the intentions. The study suggested that landowners have positive social pressure and were interested in active management but associated financial burden and risk could be shaping negative attitudes.

Climate Change and Wetlands in the Southern Great Plains: How Are Managers Dealing with an Uncertain Future?

Little guidance is available to assist wetland managers in developing climate adaptation plans. To facilitate development of recommendations for adaptation strategies, it is essential to first determine if or how wetland managers are addressing these challenges. We used an online survey to solicit feedback from wetland managers and biologists in the Southern Great Plains of North America to gain information on perceptions of wetland managers regarding climate change; assess how the effects of climate change are being addressed through management; and identify barriers to implementing climate change adaptation. The majority of wetland managers (63%) agreed they are currently experiencing effects of climate change in wetlands, and most respondents (76%) reported that changes in the timing of water availability throughout the year was the most likely impact. Managers reported using a diversity of approaches in managing for changing precipitation, with management of native and invasive plant species being the two most common practices. Lack of funding and personnel were the most commonly identified factors limiting manager's response to changing precipitation patterns. In addition, >50% of managers indicated uncertainty about the effects of climate change on wetlands as a barrier to management, which may relate to limited access to peer-reviewed science. While most of the management practices reported were short-term measures and may not reflect long-term adaptation for climate change, the fact that many managers are considering climate change in their management suggests that there is considerable opportunities to continue developing capacity for climate change adaptation in the region.

Stakeholder perceptions of bird-window collisions.

Bird-window collisions are a major source of human-caused avian mortality for which many mitigation and prevention options are available. However, because very little research has characterized human perspectives related to this issue, there is limited understanding about the most effective ways to engage the public in collision reduction efforts. To address this research need, we: (1) evaluated how two stakeholder groups, homeowners and conservation practitioners, prioritize potential benefits and obstacles related to bird-window collision management, (2) compared priorities between these groups, and (3) evaluated potential conflicts and collective strength of opinions within groups. We addressed these objectives by merging the strengths, weaknesses, opportunities, and threats (SWOT) and analytic hierarchy process (AHP) survey approaches. Specifically, survey respondents made pairwise comparisons between strengths and weaknesses (respectively, direct outcomes and barriers related to management, such as fewer collisions and increased costs) and opportunities and threats (indirect outcomes and barriers, such as increased bird populations and fewer resources for other building-related expenses). Both homeowners and conservation practitioners ranked strengths and opportunities higher than weaknesses and threats, indicating they have an overall positive perception toward reducing bird-window collisions. However, key obstacles that were identified included costs of management and a lack of policy and guidelines to require or guide management. These results suggest that substantial advances can be made to reduce bird-window collisions because both homeowners and conservation practitioners had positive views, suggesting their receptivity toward collision management measures. However, because of more neutral views and conflicting responses within the homeowner group, results also highlight the importance of targeting homeowners with education materials that provide information about bird-window collisions and solutions that reduce them. Because bird-window collisions are a human-caused phenomenon, such information about human perspectives and priorities will be crucial to addressing this threat and thus benefitting bird populations.

Mapping and modeling the components of human tolerance for black bears in eastern Oklahoma.

In North America, challenges associated with human-black bear (Ursus americanus) interactions have increased in recent decades. We used the structural equation modeling framework to understand how psychological factors such as perceived benefits, risks, social trust, salient value similarities, and locus of control interacted and described human tolerance of black bears in Oklahoma. Our results suggested that trust in the state wildlife agency's ability to manage black bears significantly affected both risk and benefits perception. The spatial hotspot analysis showed that residents of metropolitan areas had more positive attitudes toward black bears compared to rural residents, and more trust in the state wildlife management agency's ability to manage black bear populations. Trust in the state wildlife agency was low in rural areas, and specifically southeastern Oklahoma. Conversely, risk perception was higher in rural areas near one of the state's two extant black bear populations than in metropolitan areas removed from black bear ranges. We suggest that managers focus efforts on building strong relational foundations for trust between wildlife management personnel and rural residents in addition to demonstrating competence in black bear management techniques.

Climate change, risk perception, and protection motivation among high-altitude residents of the Mt. Everest region in Nepal.

Mountain ecosystems are considered vulnerable to early impacts of climate change. Whether and how local residents of these areas perceive these changes, however, remain under-studied questions. By conducting a household survey in the Khumbu region of Nepal, this study assessed local residents' experience-based perception of changes in climate trends and patterns, perceived risk, and attitudes towards climate issues. Multivariate cluster analysis based on residents' climate change beliefs revealed three segments: "Cautious," "Disengaged," and "Alarmed." A comparison of these segments along key psychosocial constructs of Protection Motivation Theory (PMT) revealed significant inter-segment differences in residents' perception of severity, vulnerability, response efficacy, self-efficacy, and response cost associated with engaging in mitigating behavior. Results shed light on how residents of high elevation areas that are considered to be exposed to early impacts of climate change perceive the risk and intend to respond. These findings could also assist stakeholders working in other similar mountain ecosystems in understanding vulnerability and in working towards climate readiness.

Cell Derived Matrix Fibulin-1 Associates With Epidermal Growth Factor Receptor to Inhibit Its Activation, Localization and Function in Lung Cancer Calu-1 Cells.

Epidermal Growth Factor Receptor (EGFR) is a known promoter of tumor progression and is overexpressed in lung cancers. Growth factor receptors (including EGFR) are known to interact with extracellular matrix (ECM) proteins, which regulate their activation and function. Fibulin-1 (FBLN1) is a major component of the ECM in lung tissue, and its levels are known to be downregulated in non-small cell lung cancers (NSCLC). To test the possible role FBLN1 isoforms could have in regulating EGFR signaling and function in lung cancer, we performed siRNA mediated knockdown of FBLN1C and FBLN1D in NSCLC Calu-1 cells. Their loss significantly increased basal (with serum) and EGF (Epidermal Growth Factor) mediated EGFR activation without affecting net EGFR levels. Overexpression of FBLN1C and FBLN1D also inhibits EGFR activation confirming their regulatory crosstalk. Loss of FBLN1C and FBLN1D promotes EGFR-dependent cell migration, inhibited upon Erlotinib treatment. Mechanistically, both FBLN1 isoforms interact with EGFR, their association not dependent on its activation. Notably, cell-derived matrix (CDM) enriched FBLN1 binds EGFR. Calu-1 cells plated on CDM derived from FBLN1C and FBLN1D knockdown cells show a significant increase in EGF mediated EGFR activation. This promotes cell adhesion and spreading with active EGFR enriched at membrane ruffles. Both adhesion and spreading on CDMs is significantly reduced by Erlotinib treatment. Together, these findings show FBLN1C/1D, as part of the ECM, can bind and regulate EGFR activation and function in NSCLC Calu-1 cells. They further highlight the role tumor ECM composition could have in influencing EGFR dependent lung cancers.

Predicting Kudzu (Pueraria montana) spread and its economic impacts in timber industry: A case study from Oklahoma.

Quantifying the economic impacts of invasive species is an essential step in developing and prioritizing invasive species management. In particular, kudzu, Pueraria montana (Lour.) Merr. is an aggressive and non-native vine that not only causes ecological damage and reduces biodiversity, but can have multiple economic consequences such as loss of timber value and volume. Using current infestation locations in Oklahoma, southcentral USA, a Monte Carlo simulation was run to estimate the natural as well as anthropogenic spread rate of kudzu in the next five years. Simulations were supplemented with an economic impact analysis within the Impact Analysis for PLANing (IMPLAN) platform. To account for economic loss in the forest product industry, a replacement cost approach with a sensitivity analysis was conducted. Occurrence data collections revealed that current kudzu populations are already established in Oklahoma forests. The results demonstrate that by year five, total industry output could be reduced by $167.9 million, which will influence 780 jobs in the most extreme case scenario. The predicted economic loss due to kudzu expansion could act as an incentive for appropriate management practices and plans to be implemented.

The ecological and economic determinants of eastern redcedar (Juniperus virginiana) encroachment in grassland and forested ecosystems: A case study from Oklahoma.

Frequent fires were used as a management tool to maintain prairies, savannas, and woodlands in the southern Great Plains of the United States. However, fire exclusion beginning in the mid-1900s allowed for the establishment and growth of fire-intolerant species such as eastern redcedar (Juniperus virginiana: ERC) beyond their naturally occurring habitats. Apart from the reduction in burning, wide soil and climate adaptability, and seed dispersal by birds have facilitated the expansion of ERC in the southern Great Plains. The encroachment of ERC has caused heavy ecological and economic losses to Oklahoma and thus has been a major management concern for the past few decades. This study utilized count data modeling to analyze USDA Forest Service's (USFS) Forest Inventory and Analysis (FIA) data to investigate the relationship between available ecological and economic factors and the abundance of ERC in grassland and forested ecosystems of Oklahoma. The results suggested that low site productivity, high basal area, dense canopy, and silt loam soil texture significantly increase the abundance of ERC on a given site. The results also indicated that the rate of ERC encroachment is 3.3% higher in the softwood and 2.0% higher in the miscellaneous forests, compared to the hardwood forests. However, the economic variables of the study such as ownership type, adoption of active management, and proximity to a metropolitan area did not show a significant relationship to the abundance of ERC.

The Paradox of Declining Female Work Participation in an Era of Economic Growth.

The past three decades have seen the advent of major transformations in the Indian economy. The economy has achieved average growth rates of 5-9 per cent, education has risen sharply for both men and women, fertility rates have declined, and infrastructure facilities, particularly access to electricity, cooking gas and piped water, have improved. All these factors are expected to reduce the demand for women's time spent in domestic chores and increase their opportunities for paid work. Paradoxically, however, the National Sample Surveys document a substantial decline in women's Work Participation Rates (WPRs), particularly for rural women. Optimistic interpretation of these trends suggests that increasing prosperity accounts for women's labour force withdrawal. For young women, rising school and college enrolment is incompatible with demands of the workforce. For both young and older women, rising prosperity allows for withdrawal from economic activities to focus on domestic duties. Pessimistic interpretations of these trends suggest that it is absence of suitable jobs rather than women's withdrawal from the labour force that accounts for declining female work participation. A third explanation focuses on increasing measurement errors in work participation data from the National Sample Surveys. This paper examines these diverse explanations using data from National Sample Surveys and India Human Development Surveys for 2004-5 and 2011-12 and finds that: (1) Decline in rural women's work participation recorded by National Sample Surveys may be overstated; (2) Supply factors explain a relatively small proportion of the decline in women's work participation rates; (3) Public policies such as improvement and transportation facilities and MGNREGS that enhance work opportunities for women are associated with increased participation by women in the work force.

Determinants of perceived risk and liability concerns associated with prescribed burning in the United States.

While prescribed burning is a proven tool in the management of forests and grasslands, its use has been limited due, in part, to potential risks that may result in legal liability, property damage, and personal injury. The purpose of this study is to understand the factors that shape landowners' and fire professionals' perceptions of risks associated with prescribed burning activities. The data for this study were collected from active prescribed fire professionals involved in Prescribed Burn Association (PBA) activities in 14 Southern and Mid-western states. Perceived risk was higher among respondents with higher levels of concern related to safety and weather but lower among respondents with more experience in burning activities. Sociodemographic variables such as age and income were not significantly correlated with risk perception. These findings are useful for better understanding how landowners and fire professionals perceive risk and offer insight into how perceived risk affects decisions to apply prescribed burns.

Perceptions of Government and Research Expert Groups and Their Implications for Watershed Management in Oklahoma, USA.

The collaborative approach for sustainable management of watersheds is built on engagement of diverse stakeholders. Climate variability and anthropogenic activities increasingly impose challenges to successful management, as do contrasts in stakeholder perceptions about those processes. To assess differences in perceptions about watershed issues, we conducted a focus group meeting of expert stakeholder groups from research institutions, and state and federal agencies in the management of Cimarron River Watershed, Oklahoma. We employed the Strengths, Weaknesses, Opportunities, and Threats (SWOTs) approach to identify important issues, and the analytic hierarchy process to rank the perceptions of these groups. We found incongruity between these two groups over internal factors (SW) and external factors (OT) risking sustainable watershed management. External threats such as climate change dominated the research group perceptions, whereas internally prevalent weaknesses such as inability to track water use and lack of a common platform to share scientific data, dominated the government group perceptions. Despite these differences, both groups identified the negative aspect (W + T) as dominant over the positive aspect (S + O), which suggests a pessimistic watershed management future, with risks prevailing over the opportunities. We see this particular congruity of these two stakeholders as an opportunity to initiate a collaborative approach to watershed management in Oklahoma. We also note that the most important factor from each group corresponds to a relatively modest importance from the other group, and therefore suggests the possibility of cooperation rather than conflict in management goals should collaborative watershed management become established in the watershed.

Stakeholder opinions on scientific forest management policy implementation in Nepal.

Despite its widespread recognition as a successful model of participatory forest management, the community forestry program in Nepal is often criticized for its protection-oriented emphasis. Recognizing the need for more active timber management, the government of Nepal recently adopted a scientific forest management (SFM) policy in the lowland tropical region. In this study, strength, weakness, opportunity, and threat analytical hierarchical process criteria were employed to understand stakeholder perceptions concerning SFM implementation in Nepal. The overall perception was prioritized in the order of strengths (35%), threats (28%), opportunities (22%), and weaknesses (16%). The study results suggest that there is agreement among stakeholders regarding the need for active management of forests in the tropical lowland region. However, the perceptions of academic researchers and non-government organization professionals differed from those of the other stakeholders in that those two groups were more concerned about potential corruption and uncertainties surrounding policy and legal issues. The findings suggest that the long-term success of SFM may depend on the ability of the government to develop a mechanism that is transparent and capable of ensuring equitable benefit sharing among stakeholders. While the stakeholder perception analysis performed in this study was focused on SFM implementation in Nepal, the results could have implications for other countries that practice the participatory model of forest governance as well.

Factors Affecting Public Preferences for Grassland Landscape Heterogeneity in the Great Plains.

Agricultural intensification has fragmented rangelands in the Great Plains, which has contributed to uniform and homogeneous landscapes and decreased biodiversity. Alternative land management practices involving fire-grazing interactions can help maintain biodiversity without affecting livestock productivity. A survey was designed to understand the factors that influence preferences among the general population towards grassland landscape heterogeneity. Given the ordinal nature of survey responses, requisite data were analyzed using a generalized ordinal logit model. Results suggested that respondents who valued open space and those who recognized a need for a varying mix of uniform grasses and grasslands preferred landscape heterogeneity. Female respondents were about two times as likely to prefer heterogeneous landscapes compared to male respondents. In contrast, population groups that preferred wildlife habitat did not desire heterogeneous landscapes. Results suggest the need for extension and outreach activities to educate certain segments of the general population regarding benefits of alternative management practices that support landscape heterogeneity in the Great Plains.

Adsorption and function of recombinant Factor VIII at the air-water interface in the presence of Tween 80.

The air-water surface tension kinetic and steady state behavior exhibited by a recombinant Factor VIII were recorded in the presence of the surfactant Tween 80. The rate of surface tension decrease was determined to be greater for rFVIII-Tween mixtures than for Tween acting alone, at all Tween concentrations studied (8-108 ppm). In addition, steady state interfacial behavior was determined to be governed entirely by surfactant adsorption in mixtures with Tween concentrations greater than or equal to about 18 ppm. The formation of aggregates, tertiary structure change, and biological activity of rFVIII in agitated as well as unagitated samples were monitored using turbidity measurements, intrinsic fluorescence spectroscopy, and the activated partial thromboplastin time, respectively. The results are consistent with two mechanisms characterizing the surfactant-mediated stabilization of rFVIII: the rapid, preferential adsorption of Tween molecules relative to rFVIII molecules at the air-water interface, and Tween association with rFVIII in solution to provide a steric barrier to aggregation. While both mechanisms are relevant in the presence of an interface, evidence recorded here suggests that the preferential adsorption of Tween at the interface is the major stabilization mechanism while the effectiveness of Tween association with rFVIII is compromised in agitated samples.

Solid surface chemical and physical effects on the adsorption of recombinant Factor VIII.

The adsorption of a recombinant Factor VIII to silica surfaces coated to present different hydrophilic/hydrophobic, electrostatic and steric characteristics was monitored in situ, with ellipsometry. rFVIII adsorption affinity was high for hydrophobic surfaces and hydrophilic, charged surfaces. A lower affinity was recorded between rFVIII and a neutral hydrophilic surface, with substantial reduction in rFVIII adsorption to electronically neutral surfaces presenting pendant poly[ethylene oxide] chains. We conclude that steric repulsion is a requirement for minimizing rFVIII adsorption at solid surfaces.

Adsorption behavior of lysozyme and Tween 80 at hydrophilic and hydrophobic silica-water interfaces.

Nonionic surfactants such as Tween 80 are used commercially to minimize protein loss through adsorption and aggregation and preserve native structure and activity. However, the specific mechanisms underlying Tween action in this context are not well understood. Here, we describe the interaction of the well-characterized, globular protein lysozyme with Tween 80 at solid-water interfaces. Hydrophilic and silanized, hydrophobic silica surfaces were used as substrates for protein and surfactant adsorption, which was monitored in situ, with ellipsometry. The method of lysozyme and Tween introduction to the surfaces was varied in order to identify the separate roles of protein, surfactant, and the protein-surfactant complex in the observed interfacial behavior. At the hydrophobic surface, the presence of Tween in the protein solution resulted in a reduction in amount of protein adsorbed, while lysozyme adsorption at the hydrophilic surface was entirely unaffected by the presence of Tween. In addition, while a Tween pre-coat prevented lysozyme adsorption on the hydrophobic surface, such a pre-coat was completely ineffective in reducing adsorption on the hydrophilic surface. These observations were attributed to surface-dependent differences in Tween binding strength and emphasize the importance of the direct interaction between surfactant and solid surface relative to surfactant-protein association in solution in the modulation of protein adsorption by Tween 80.

Adsorption and function of recombinant factor VIII at solid-water interfaces in the presence of Tween-80.

The adsorption, structural alteration and biological activity of a recombinant Factor VIII was investigated in the presence of the surfactant Tween-80, at hydrophilic and hydrophobic solid-water interfaces. Hydrophilic and silanized, hydrophobic silica surfaces were used as substrates for protein and surfactant adsorption, which was monitored in situ, with ellipsometry. At the hydrophobic surface, the presence of Tween in the protein solution resulted in a reduction in amount of protein adsorbed, while rFVIII adsorption at the hydrophilic surface was entirely unaffected by the presence of Tween. These observations were attributed to high binding strength between Tween and the hydrophobic surface, and low binding strength between Tween and the hydrophilic surface. Colloidal particles bearing hydrophilic and hydrophobic surfaces, and net positive or negative surface charge, were used as substrates for rFVIII adsorption in evaluation of tertiary structure change and biological activity retention at interfaces. Fluorescence emission spectroscopy showed that rFVIII tertiary structure was changed upon exposure to hydrophobic nanoparticle surfaces. Similarly, the biological activity of rFVIII (based on the activated partial thromboplastin time) was reduced at hydrophobic surfaces. At high surfactant concentration, these properties were better preserved. This was attributed to Tween adsorption sterically inhibiting rFVIII adsorption. While hydrophilic surfaces were associated with relatively high rFVIII adsorption, they did not induce large changes in structure or activity. This was attributed to the formation of a tightly packed, ordered adsorbed layer on these surfaces, governed by electrostatic attraction and not mediated by the rFVIII active site.