The strength of long ties and the weakness of strong ties: Knowledge diffusion through supply chain networks

AbstractUsing a large firm-level panel dataset for Japan, this paper examines the effects of the structure of supply chain networks on productivity and innovation capability through knowledge diffusion. We find that ties with distant suppliers improve productivity (as measured by sales per worker) more than ties with neighboring suppliers, which is likely because distant firms’ intermediates embody more diversified knowledge than those from neighboring firms. Ties with neighboring clients improve productivity more than ties with distant clients, which is likely because neighboring clients more effectively diffuse disembodied knowledge than distant clients. By contrast, ties with distant suppliers and clients improve innovative capability (as measured by the number of registered patents), whereas ties with neighboring suppliers or clients do not affect innovative capability. In addition, the density of a firm's ego network (as measured by how densely its supply chain partners transact with one another) has a negative effect on productivity and innovative capability, implying knowledge redundancy in dense networks. These results suggest that access to diversified ties is important for improving productivity and innovation capability through knowledge diffusion

The role of motorized transport and mobile phones in the diffusion of agricultural information in Tanggamus Regency, Indonesia

Limited access to agricultural information constrains the well-being of farmers in developing countries and leads to environmental deterioration. Although new information-communication technologies (ICTs) are expected to alleviate this problem, the importance of physical mobility is rarely considered. This study explores the roles of motorized transport and mobile phones in the diffusion of agricultural information within and between Indonesian farming communities. In 2012, we surveyed 315 household heads from 16 coffee and cocoa farming groups in Sumatra. The respondents identified 1575 sources from which they obtained agricultural information, the exact location of the sources, and the mode of contact. In 2013, we followed up with in-depth interviews of 20 farmers to obtain a qualitative description of their agricultural information-seeking behavior. Although 75 % of respondents had a mobile phone, the main mode of information sharing was face-to-face meetings for 97 % of the elicited relationships. Mobile phones were used to communicate with people living at the edge of the regular physical mobility radius enabled by motorbikes (approximately 10 km). A hierarchical logit model was applied to examine the implications of the respondents’ tendency to use motorized transport vis-à-vis walking for information gathering. Respondents with a higher general preference for faster transport tended to have more extensive access to information from other communities. However, we also find weak evidence that individual motorized transport might decrease internal social contact and information exchange inside these communities. The policy implication for rural development in less-industrialized countries is that providing ICTs without increasing the inhabitants’ mobility through appropriate means may not significantly improve the inhabitants’ access to important information and the diffusion of successful agricultural practices. </p

Transmigration programs and migrant positions in rural community knowledge networks

Controversial transmigration programs have moved millions of people from the cores of domestic economies to national geographical peripheries to ostensibly facilitate a more equitable resource distribution. However, it is not well understood how transmigrants become accepted and how they position themselves within the local networks of migrant-receiving rural communities. We examine how ethnicity and transmigratory experience affect informal knowledge-sharing networks in 16 coffee and cocoa farmer groups in Lampung, Indonesia. Drawing on these social networks and key socio-economic characteristics of 315 farming group members, we examine core-periphery network structures and centrality distributions within these farming groups. We show that individuals from the majority ethnomigration group who are the descendants of Javanese migrants tend to form the core of the local farmers’ knowledge networks, apparently benefiting both from strong cultural links to the central regions of the country in Java as well as strong embeddedness in local communities. Our findings also call attention to possible marginalization of original members of peripheral rural communities in central government-sponsored transmigration and export-oriented agricultural extension programs.</div

Reprint of: Participant engagement in environmentally focused social network research

Environmentally focused social network analysis (Env. SNA) has increasingly benefited from engagement, which refers to the process of incorporating the individuals, organizations, actors, stakeholders or other study participants into the research process. Research about engagement in the wider field of environmental management shows that successful engagement often requires significant planning and exchange among researchers and stakeholders. While there is no one size fits all approach, several important guiding principles have been established. To date, this engagement literature has not focused specifically on SNA, even though several examples of engaged SNA exist in the literature and point to some specific challenges to engagement when working with relational data. Drawing upon data from a survey of researchers who have incorporated engagement into Env. SNA, we focus specifically on the goals, scope, effectiveness, benefits and challenges of doing engaged Env. SNA research. We additionally highlight four case studies and demonstrate that researchers and participants find engagement to be a valuable experience with benefits in the researchers’ understanding of the context and meaning of their findings. Finally, we provide recommendations to scholars looking to embark on engaged Env. SNA research

Non-steroidal anti-inflammatory drugs target TWISTED DWARF1-regulated actin dynamics and auxin transport-mediated plant development

The widely used non-steroidal anti-inflammatory drugs (NSAIDs) are derivatives of the phytohormone salicylic acid (SA). SA is well known to regulate plant immunity and development, whereas there have been few reports focusing on the effects of NSAIDs in plants. Our studies here reveal that NSAIDs exhibit largely overlapping physiological activities to SA in the model plant Arabidopsis. NSAID treatments lead to shorter and agravitropic primary roots and inhibited lateral root organogenesis. Notably, in addition to the SA-like action, which in roots involves binding to the protein phosphatase 2A (PP2A), NSAIDs also exhibit PP2A-independent effects. Cell biological and biochemical analyses reveal that many NSAIDs bind directly to and inhibit the chaperone activity of TWISTED DWARF1, thereby regulating actin cytoskeleton dynamics and subsequent endosomal trafficking. Our findings uncover an unexpected bioactivity of human pharmaceuticals in plants and provide insights into the molecular mechanism underlying the cellular action of this class of anti-inflammatory compounds

MRS Drone: A Modular Platform for Real-World Deployment of Aerial Multi-Robot Systems

This paper presents a modular autonomous Unmanned Aerial Vehicle (UAV) platform called the Multi-robot Systems (MRS) Drone that can be used in a large range of indoor and outdoor applications. The MRS Drone features unique modularity with respect to changes in actuators, frames, and sensory configuration. As the name suggests, the platform is specially tailored for deployment within a MRS group. The MRS Drone contributes to the state-of-the-art of UAV platforms by allowing smooth real-world deployment of multiple aerial robots, as well as by outperforming other platforms with its modularity. For real-world multi-robot deployment in various applications, the platform is easy to both assemble and modify. Moreover, it is accompanied by a realistic simulator to enable safe pre-flight testing and a smooth transition to complex real-world experiments. In this manuscript, we present mechanical and electrical designs, software architecture, and technical specifications to build a fully autonomous multi UAV system. Finally, we demonstrate the full capabilities and the unique modularity of the MRS Drone in various real-world applications that required a diverse range of platform configurations.Comment: 49 pages, 39 figures, accepted for publication to the Journal of Intelligent & Robotic System

High proportion of recurrent germline mutations in the BRCA1 gene in breast and ovarian cancer patients from the Prague area

BACKGROUND: Germline mutations in the BRCA1 and BRCA2 genes have been shown to account for the majority of hereditary breast and ovarian cancers. The purpose of our study was to estimate the incidence and spectrum of pathogenic mutations in BRCA1/2 genes in high-risk Czech families. METHODS: A total of 96 Czech families with recurrent breast and/or ovarian cancer and 55 patients considered to be at high-risk but with no reported family history of cancer were screened for mutations in the BRCA1/2 genes. The entire coding sequence of each gene was analyzed using a combination of the protein truncation test and direct DNA sequencing. RESULTS: A total of 35 mutations in the BRCA1/2 genes were identified in high-risk families (36.5%). Pathogenic mutations were found in 23.3% of breast cancer families and in 59.4% of families with the occurrence of both breast and ovarian cancer. In addition, four mutations were detected in 31 (12.9%) women with early onset breast cancer. One mutation was detected in seven (14.3%) patients affected with both a primary breast and ovarian cancer and another in three (33.3%) patients with a bilateral breast cancer. A total of 3 mutations in BRCA1 were identified among 14 (21.4%) women with a medullary breast carcinoma. Of 151 analyzed individuals, 35 (23.2%) carried a BRCA1 mutation and 9 (6.0%) a BRCA2 mutation. One novel truncating mutation was found in BRCA1 (c.1747A>T) and two in BRCA2 (c.3939delC and c.5763dupT). The 35 identified BRCA1 mutations comprised 13 different alterations. Three recurrent mutations accounted for 71.4% of unrelated individuals with detected gene alterations. The BRCA1 c.5266dupC (5382insC) was detected in 51.4% of mutation positive women. The mutations c.3700_3704del5 and c.181T>G (300T>G) contributed to 11.4% and 8.6% of pathogenic mutations, respectively. A total of eight different mutations were identified in BRCA2. The novel c.5763dupT mutation, which appeared in two unrelated families, was the only recurrent alteration of the BRCA2 gene identified in this study. CONCLUSION: Mutational analysis of BRCA1/2 genes in 151 high-risk patients characterized the spectrum of gene alterations and demonstrated the dominant role of the BRCA1 c.5266dupC allele in hereditary breast and ovarian cancer

Social networks and environmental management at multiple levels: soil conservation in Sumatra

Many agrarian communities in developing countries suffer from insufficient productivity and use farming practices that deteriorate the environment both locally and globally. Research suggests that social networks play a role in environmental management, different studies emphasize different aspects of network structures, and the implications of the scales at which networks operate are not explicitly discussed. Here, I ask what types of social structures in farmer networks are conducive to environmental protection and agricultural productivity enhancement, and I show that the answer depends on the scale of the investigation. Using original data representing 16 farmer groups comprising 315 households and 1575 information-sharing links, I analyzed the structure of farmers' social connections in relation to their soil conservation and productivity-enhancing practices, assessed through their usage of organic and chemical fertilizers. Furthermore, I conducted qualitative interviews with 25 stakeholders from different levels of the agricultural system to gain additional insights into the drivers of farmers' behaviors. The quantitative analysis distinguishes the effects of intra- and extra-group links and reciprocity at the household and group levels. Fixed-effects logistic regression was applied at the household level to examine farmers' soil management practices. At the collective level, I used linear regression to estimate the proportion of adopters for each soil management practice. A lack of education and a lack of extra-group links are associated with unproductive practices, and a lack of reciprocity is associated with a lack of conservation efforts at both the household and collective levels. Dense intra-group links have opposite effects at the two levels. Whereas links within the farmer groups are associated with unproductive soil management by households, these links are associated with productivity maximization at the collective level. Qualitative interviews showed that farmers who opt for organic fertilizers do so partially because of pressure from global traders, mediated through external links and amplified by dense and reciprocal relations within their groups. The results highlight the need for environmental management policies to be based on research at multiple scales and demonstrate that, counter-intuitively, increasing global economic interconnectivity may, in some cases, stimulate the adoption of conservation practices via local social networks

Complementarity and substitution between physical and virtual travel for instrumental information sharing in remote rural regions: A social network approach

International development practitioners are highly optimistic that mobile phones can improve the lives of the inhabitants of remote rural areas in developing countries with an underdeveloped transportation infrastructure. However, the instrumental role of telecommunication is unclear in contexts where residents’ information-sharing networks are strongly geographically constrained by their limited mobility. Empirical research on the interactions between telecommunication and travel in rural areas of developing countries is lacking. This study analyses physical and virtual contact patterns within 1270 instrumental information-sharing relationships reported by the inhabitants of the Pulau Panggung and Sumber Rejo rural subdistricts of Indonesia. In 2013, we implemented an exogenous mobility intervention. In 2014, we administered a network survey in 16 randomly selected farming groups to map local residents’ egocentric and sociocentric physical and virtual travel networks. By comparing the observed networks with simulated random networks, analysing the relationship characteristics and their history, and performing a regression analysis with fixed effects, we examine the complementarity and substitution between telecommunication and travel in the creation and maintenance of social networks. By examining the effects of the exogenous intervention, we can explain the mechanisms underlying the uncovered associations. The results suggest path dependency between physical and virtual travel in remote rural areas. The implication for transportation policy is that physical mobility is a precondition for the creation of virtual information-sharing links. Instrumental communication relationships that do not socially require regular physical co-presence can be partially substituted by virtual travel only after virtual links have been created through physical mobility. Therefore, in contrast with general expectations, mobile telephony in remote rural regions is more practical if the transportation infrastructure is adequately developed. The paper concludes with a discussion of the potential contribution of the sociocentric network perspective to transportation research