bluuebunny/crossref_metadata_2025 huggingface dataset:
The Political Economy of Education and Development in Central America and the Latin Caribbean: Regional Dynamics and a Framework for Analysis
Authors: Edwards D. Brent
Published: October 2024

This chapter concerns itself with three tasks: first, to depict some key historical and regional dynamics in Central America from a political economy perspective; second, to contextualize education reform in relation to international political-economic forces affecting the region; and, third, to outline the framework that informs the analysis and commentary presented in subsequent chapters. The purpose is not only to provide essential background context relevant to all the chapters in this volume, but also to make explicit the dimensions and tensions to which the chapters in this volume speak. In order to address the purposes set out earlier, the chapter first characterizes regional political-economic dynamics from a historical perspective from the 1800s to 1970. The chapter then turns to contextualizing education reform in relation to international political-economic forces affecting the region. This section is likewise historically and regionally focused. It attends to the pressures facing the education systems of Central America from the 1950s to the 1980s, the period in which education systems began to expand dramatically – and often with assistance from international organizations. The final section of the chapter pivots to present the framework – rooted in international political economy – that serves as the overarching analytic lens for the present volume.
Balancing Global Education Policy and Inclusive Education in Costa Rica: Capitalist Pressures, Social-Democratic Tendencies, and Technological Responses
Authors: Pietras Vanessa
Published: October 2024

This chapter focuses on the dynamic but often conflicting global forces and local responses in the field of education reform. Global economic forces drove certain aspects of the case of Costa Rica. For instance, pressure from multinational corporations induced the Costa Rican government to change its national curriculum. These corporations needed more skilled labour to continue their operations in Costa Rica and called on the government to modernize its education system to meet the needs of capitalist development. In 2015 the Public Education Ministry (Ministerio de Educación Publica [MEP]) implemented education reforms containing a new curriculum to retain technology companies and satisfy capitalist development. With Costa Rica being a hybrid social-democratic, capitalist system, the MEP had to find a way to blend the concepts and practices that underlie the traditional Costa Rican vision with that of the foreign investors. This blending undermined the legitimacy of the reform effort and threatened to exacerbate gaps in student learning across the country. In response, the MEP turned to international guidelines for planetary citizenship to inform their inclusive education efforts and developed the Tecno@prender programme to ensure students in socioeconomically vulnerable zones had full access to technology.
Edtech and Equity in Panama: Mobile Technology for Levelling the Learning Playing Field
Authors: Svenson Nanette Archer , Leon Mariana
Published: October 2024

Access to quality education in the Republic of Panama is a topic of growing concern. The COVID-19 pandemic served to highlight the importance of this issue and its connection with information and communications technology. As remote learning assumed a critical role during the global pandemic, education technology (edtech) became a familiar concept and a determinant of families’ abilities to access instruction for their school-aged children. The situation prompted complex questions about the political economy of edtech, digital inequality, and the future of learning. This chapter examines edtech and equity in Panama, focusing on mobile technology as a potential means to levelling the learning playing field. It discusses two collaborative low-tech projects to propel basic skills acquisition for children in their early years of schooling that were implemented nationwide in 2020 while schools were closed. It links the knowledge generated from the study of these projects to the broader discussion of global forces that shape education delivery and local responses that work to drive equity and inclusion.
The Dialectics of Education and Development in Central America and the Latin Caribbean
Authors: Edwards D. Brent
Published: October 2024

One characteristic of the relationship between education and development in Central America and the Latin Caribbean (CALC) is its dialectical nature. Although research on the region rarely speaks to this characteristic, it is clearly evident when looking across the cases presented in this volume. By dialectical nature, this chapter refers, first, to the reality that education helps to resolve or reduce tensions between the state and capitalism and, second, to the fact that the ways in which this tension is resolved repeatedly creates new opportunities for a range of international actors to insert themselves into education reform dynamics in the region. Involvement by these actors, together with counterparts from state agencies then proceeds – typically while ignoring or without input from teachers, students, and families – until a new crisis emerges, at which point the cycle repeats itself. The goal of this chapter is to make explicit that which is typically unacknowledged or insufficiently addressed in research on education in CALC – that is, the extent to which education is inextricably linked to and constrained by tensions and incentives produced as a result of the relationship between the state and the global capitalist economy.
The Trouble with Jokes
Authors: Butler Nick
Published: October 2024

The Trouble with Jokes explores the hidden risks of humour in civic life. Weaving together cultural analysis, political discussion, and philosophical reflection, the book explores humour as a complex and contradictory phenomenon at the heart of modern society. The main argument of the book is that humour is a political discourse that thrives on transgression and outrage. In the public sphere, offensive jokes obscure the line between irony and sincerity, which lowers our defences against objectionable ideologies. This explains why humour has fuelled some of the most worrying political trends today, such as the rise of the far right, the spread of online conspiracy theories, and the resurgence of violent misogyny. Academic studies on humour and politics, with some notable exceptions, tend to overstate the extent to which jokes can subvert power relations or liberate us from oppression. This book, by contrast, examines the more problematic aspects of humour. Its aim is twofold: to understand the relation between comedy and cruelty in contemporary culture and politics, and to challenge the idea that humour is primarily a progressive force in society.
Prankster Diplomacy
Authors: Butler Nick
Published: October 2024

Chapter 3 explores the political significance of humour in liberal democracies and authoritarian regimes. In the second half of the 20th century, a sense of humour became a desirable trait, not only for individual citizens, but also for our elected representatives. The ability to tell a good joke is a way for political leaders to demonstrate that they’re smart, charismatic, and in tune with popular sentiment. And if our elected representatives should ever stray from the path of honesty and integrity, biting political satire will expose their failings. Humour is so closely aligned with the values of liberal democracy, such as tolerance and open-mindedness, that a lack of humour is often associated with brutal dictatorships like the Third Reich or North Korea. But, as the chapter contends, this underplays the extent to which boundary-pushing humour can serve also fascistic ends, such as coating virulent antisemitism with a veneer of winking irony or dressing up violent racism as cheeky banter. Jokes don’t have a political allegiance, but they do target those who appear to take themselves too seriously – which, for the far right, includes anyone who believes in equality, diversity, and inclusion.
Evil Clowns
Authors: Butler Nick
Published: October 2024

Chapter 4 discusses the most clown-like political leaders in recent history: George W. Bush, Donald J. Trump, and Boris Johnson. Over the last decade, a number of professional funnymen have entered the world of politics: Jimmy Morales in Guatemala, Beppe Grillo in Italy, and Volodymyr Zelenskyy in Ukraine. Unlike these comedians-turned-politicians, Bush, Trump, and Johnson engage in a hybrid form of politics we might call ‘clownsmanship’, a portmanteau that combines clowning and statesmanship. In the same way as circus clowns, these world leaders are simultaneously amusing and terrifying, and we don’t know whether to laugh or cry at their repeated blunders and provocations. Bush’s unintentionally funny slips of the tongue, Trump’s ludicrous boasts and insults, and Johnson’s shambling persona and comic exaggeration – these are more than personal defects. As the chapter demonstrates, they’re politico-comic strategies to gain power, deflect criticism, and avoid accountability. Taboo-busting humour is the backdrop to a certain type of anti-establishment politics, yet we’re so preoccupied by all the monkey business that we fail to realize that the joke’s ultimately on us.
Conclusion
Authors: Butler Nick
Published: October 2024

The conclusion provides an extended analysis of Trevor Griffith’s 1975 stage play Comedians, which has become a touchstone for thinking critically about humour. Set in an evening class for amateur stand-ups in the north of England, the play explores key tensions around comedy: its ability to comfort, its willingness to shock, its flair for critique, and its propensity for violence. In the play, it’s never clear where we’re supposed to draw the line between joke-telling and hatemongering, or if there’s a line to be drawn in the first place. The play – like this book – leaves us with no easy answers and offers few consolations.
Introduction
Authors: Harrison Graham
Published: October 2024

No one interested in contemporary politics can ignore social media. However, how one treats social media is still an unclear. For many, it is seen as a difficult and noisy venue for chaotic political point scoring. One way to think constructively about social media is to disaggregate it and identify zones within it that obey basic rules of political coherence. We define this as ‘political social media’ (PSM). From here, we consider the methodological issues concerning research into social media: how to treat social media text as evidence, how to identify its properties amid the rapidity and contention of online political discussion. These methodological considerations lead to an analytical procedure in which PSM is investigated as a bundle of proto-ideologies: distinct projects of concept assemblage that contest with each other not only to win arguments but to be relevant and to win followers.
Contention
Authors: Harrison Graham
Published: October 2024

This chapter explores the bones of contention between the two socialist proto-ideologies. It starts by recalling and giving more detail to aspects of the proto-ideology discussion. When contending space in political social media (PSM), each proto-ideology deploys aesthetics, specific themes, and affect to bolster its position. This means that debate is in part about logic and evidence and in part about the impressions made to each proto-ideology’s image. We explore in detail how Brexit and lockdown were treated by both proto-ideologies, identifying how disparate and often incommensurable they were. Democratic Marxist Nationalism (DMN) asserted its commitment to democracy and argued for a resilient politics during crisis. Identitarian Socialism argued for a more protective and inclusive politics, especially needed as both Brexit and lockdown were seen as manifestations of an all-encompassing crisis.
Migration and (Surveillance) Capitalism
Authors: Korkmaz Emre Eren
Published: October 2024

In addition to discussing the consequences of capitalist policies in migration; this chapter demonstrates how surveillance technologies in this field provide valuable data on the trajectory of capitalism.
A large number of companies and states invest in these fields, but further debate is needed on motivations besides profit maximization, such as how alliances are formed, which actors set the agenda, and how capitalists use the outcomes. This is related to the process by which surveillance technologies provide global capitalism with immense power to reshape and reposition the global proletariat.
At a time when large masses of people move quickly, these technologies make it possible to identify migrants before they even arrive at the border, analyse their data, decide on whether to allow them entry, and closely monitor those allowed in. This process of selection and the interests of capitalism in shaping the labour market constitute the essence of the issue.
Organising for Change
Authors: Roth Silke , Saunders Clare
Published: October 2024

This book contributes to a theory of social change by putting social change organisations (SCOs) and social change makers (SCMs) at the centre of analysis. SCOs are organisations that bring about and resist social change through protest, advocacy, and service provision. One of their most important resources are individual SCMs that drive them and otherwise contribute. Roth and Saunders develop a historical and constructivist approach that allows previously diverse literatures on social movements, non-governmental organisations (NGOs) and the third sector to be fruitfully interwoven. The analytical approach adopted in Organising for Change recognises how SCOs and SCMs shape each other, as well as how they are shaped by and shape broader social change processes and the people involved in them. The constructive approach deployed facilitates critical evaluation of the strategies of SCOs and the resources they must mobilise to pursue their goals. The book considers collaborative, competitive and conflictual relationships between SCOs and the legislative, cultural, and biographical outcomes of their activities. Organising for Change contributes to the study of social movement, non-governmental, and not-for-profit organisations and discusses a wide range of social justice issues including gender, labour, environmental justice, and humanitarianism. The book draws on the original research on SCOs addressing a wide range of causes and issues that the authors have carried out over the past 30 years in the UK, the US, Europe and globally employing a range of qualitative and quantitative methods.
Introduction
Authors: Roth Silke , Saunders Clare
Published: October 2024

This chapter introduces the core concepts and ideas of the book and why they matter. The book is about the wide range of organisations that are responding to crises and are involved in bringing about and resisting social change. The book, Organising for Change, introduces the concepts of social change organisations (SCOs) and social change makers (SCMs). The introduction first situates the argument about the importance of SCOs and SCMs within contemporary times and stresses their importance for shaping societies. The contributions that a range of strategically differentiated and sometimes overlapping SCOs can and do make to social change and to each other in synergy through sets of interactions and reactions will be examined. To do so, the chapter brings into dialogue different and hitherto largely unconnected bodies of scholarship on social movement organisations, non-governmental organisations and not-for-profit organisations. At the end of the introduction, data and methods on which the book is based are described and an overview of the book is provided.
Outcomes of Social Change Making
Authors: Roth Silke , Saunders Clare
Published: October 2024

The book argues that SCOs are co-producers of social change that are simultaneously creating and responding to social change and continue to be involved in historical, political, and social transformations. This chapter returns to the outcomes of SCOs. Four broad categories of SCO ‘outcomes’ are distinguished. Political and legislative outcomes include institutional transformation. Mobilisation outcomes encompass networking and diffusion processes. Socio-cultural outcomes include changed public attitudes. Finally, the effects on individuals are examined, both those who are involved in social change making (internal individual outcomes) as well as individuals who benefit (or not) from the material/well-being services provided by SCOs (external individual outcomes). The different outcomes reflect the goals and strategies of SCOs as well as the context in which they operate. It is noted that the different types of outcomes of SCOs are often related to one another and that SCOs often achieve more than one outcome. Nevertheless, it is important to analytically distinguish between different types of outcomes and how they are related (or not).
Experiments in Situ : Soil Repair Practices as Part of Place-Based Action for Change in El Salvador
Authors: Millner Naomi
Published: October 2024

Agroecological networks have long valorized the experience of small-scale farmers and have cultivated processes of in situ experimentation to systematically evaluate the effectiveness of traditional techniques. In this chapter I suggest that this focus on experience and experimentation is vital within broader ecologies of ‘mending’ environmental damage, and to the ideas of ecological reparation put forward by this book. Specifically, I suggest that the loop of collective reflection on experience afforded by the examples I document in El Salvador allow for a supplementation of official histories with small stories; with purposefully censored collective memory; and with everyday expertise. The case presented in this chapter is engaged in experimental soil repair through composting practices and the creation of ‘biofertilizers’ – recipes that use local organic ingredients to boost soil health. I show how agroecological approaches to soil repair place campesino expertise at the heart of agricultural innovation and ecological reparation. Together, these fuller archives allow for a wider array of possible solutions to soil damage, while also enabling contestation to take place over stories told over land, ownership, lives, and communities.
Reflections on a Mending Ecology through Pastures for Life
Authors: Waterton Claire
Published: October 2024

In this chapter I describe the practices of farmers who are rearing beef cattle exclusively on the forage of grass pastures as ‘mending ecologies’. To mend ecologies requires intimate observation of what has broken down, as well as specific spaces for experimentation, collaboration and repair. I describe how this mending, and the new ecologies that emerge as a result, involve a gradual re-materialization of the whole body of the farm, in a way that counters the mode of production of industrialized livestock agriculture. Farmer members of the Pasture Fed Livestock Association (PFLA) are deliberately making spaces for this re-materialization: their farms are accommodating new forms of attention and human labour, new multi-species interactions, and new configurations of infrastructure and expertise. Such re-arrangements are risky and fallible. But they are, at the same time, a hopeful reclamation of the socioecological fabric – part of what our editors have called the ‘unfolding, relational and inter-connected movements of ecological reparation’. As such, they brim with a new sensual repertoire – bringing new sounds, colours, textures, rhythms and emotions to the material practices of the livestock farm.
Waste, Improvement and Repair on Ireland’s Peat Bogs
Authors: Bresnihan Patrick , Brodie Patrick
Published: October 2024

Since the 1950s, the rural midlands of Ireland have been the site of large-scale industrial peat-cutting. With the phasing out of the peat industry, these post-industrial ‘waste’ landscapes are now being positioned as central to the country’s ‘green’ and ‘smart’ futures as sites for renewable energy, carbon sequestration and information services. Contemporary discourses of waste and bog landscapes resonate with discourses in the 18th and 19th centuries, when colonial efforts to drain and reclaim these semi-aqueous territories were driven by moral as well as economic imperatives. In this chapter, we aim to disrupt linear accounts of bog progress and ruination that rely on binaries of waste/value, to surface ‘submerged’ bog relations that pre-date and endure in spite of their designation as ‘un-valuable’ within colonial and post-colonial economies. Our contribution is that ‘repair’, rooted in maintenance, endurance and liveability, while not spectacular, resists the temporality of boom/bust, even if remaining ambivalent in political expression.
New Peasantries in Italy: Eco-Commons, Agroecology and Food Communities
Authors: Ghelfi Andrea
Published: October 2024

How to become a companion of the Earth by taking part in more than human communities of food? This is the open question that accompanies the making of alternative forms of living in the Genuino Clandestino network. In this chapter, I explore three key dimensions of becoming a peasant: farming ecological practices, food communities that links countryside and urban spaces and civic and collective use of land. By exploring the peasant return and its culture of eco-sharing, the development of self-organized peasant markets in Bologna and the community of Mondeggi Bene Comune, Fattoria Senza Padroni, we will scout the multiple practices of mending and ecological reparation that animate the everyday politics of Genuino Clandestino.
‘Obedecer a la Vida’: Environmental Citizenship Otherwise?
Authors: Cajigas Juan Camilo
Published: October 2024

Environmental citizenship scholarship has pointed out liberal rights as the focus of eco-political action. However, agroecological practices in Colombia, understood as modes of ecological reparation, broaden the scope of environmental citizenship since obligation and obeying life are key. Through an ethnographic account – in the mode of empirical philosophy – this chapter conceptualizes agroecological practices as belonging to an ecology of abundance that resists the liberal humanist understanding of environmental citizenship and economies of depletion (fuelled in this case by industrial ornamental agriculture). As a consequence, obligation is practiced as a relation that is established by a place’s dynamic unfolding, foregrounding practices of ecological reparation and an ethic of abundance.
Conversations on Benches
Authors: Dawney Leila , Brothwell Linda
Published: October 2024

This chapter is the result of a series of ‘conversations on benches’ between Leila Dawney, a cultural geographer, and Linda Brothwell, an artist, in Bristol during December 2020. Linda is renowned for initiating a repair movement in the arts through her ‘acts of care’, where she performs intricate repairs on objects in public space. Leila and Linda have been collaborating on a new iteration of Linda’s ‘acts of care’ series. This chapter explores the themes of their conversations, including the effect of austerity policies on public objects and spaces, the role of objects in generating a shared life, and our ethical relationships towards objects. It concludes by offering a provocation to care for our shared objects, arguing that small acts of repair and custodianship can shift, at the micro level, our relationships with our world, our sense of who we are, and our sense of responsibility and belonging in public space.
Curating Reparation and Recrafting Solidarity in Post-Accord Colombia
Authors: Mora-Gámez Fredy
Published: October 2024

State crimes and forced migration due to war violence and precarity are some of the ongoing entanglements of injustice in the landscape of post-accord Colombia. Within this landscape, governmental reparation and asylum solidarity are still deployed as ambitious yet widely limited techno-political projects reproducing historical and ongoing asymmetric relations of power in the encounters between states and those seeking reparation and assistance. Those projects materialize an incapacity of the state to acknowledge the multiplicity of forms of violence and displacement affecting the everyday lives of people on the move and victims of state crimes. Drawing on the repertoire of STS and its intersections with critical migration studies and posthuman understandings of memory, this chapter wonders about those worlds exceeding governmental reparation and asylum solidarity, how bodies engage in material transformative practices, and the role of non-humans in the material politics of other forms of reparation and solidarity.
Ri-Maflow: Des-pair, Resistance and Re-pair in an Urban Industrial Ecology
Authors: Checchi Marco
Published: October 2024

When a factory shuts down, it destroys the territory at environmental, economic and social level, leaving behind an ecology of despair. Resistance is the leap from despair to repair. In this chapter, I follow the story of Ri-Maflow, a recuperated factory in the north of Italy. Repair is here understood as pairing together once again what has been separated: the workers and their factory, the factory and its territory. In this sense Ri-Maflow represents an ecology of repair: beyond and against despair and degradation, recuperating a factory means repairing the lives of despaired workers made redundant by the logic of capitalist delocalizations and limiting the damage to the environment threatened by an otherwise abandoned factory with its toxic pollutants. But it also shows the other meaning of reparation: the occupation of the warehouse becomes a form of compensation for the damage that the territory and its inhabitants have suffered.
Cultivating Attention to Fragility: The Sensible Encounters of Maintenance
Authors: Denis Jérôme , Pontille David
Published: October 2024

In this chapter, we explore the attention to fragility at play in two urban maintenance settings: graffiti removal and water networks management. Drawing on ethnographic fieldworks, we show that maintenance activities consist of situated sensorial explorations by which maintainers carefully scrutinize the state of things and become attentive to their tendency to alter and transform. Paying attention to maintainers’ attention outlines ways to elaborate a specific ecological posture. Maintenance appears indeed as a situated and political process that engages materials, bodies, instruments and texts, and is accomplished through provoking and cultivating encounters within emerging ecologies wherein what acts, and what interacts, is never completely known in advance. Exploring attention to fragility thus helps to reconsider how humans interact with things beyond ‘cultural’ or ‘symbolic’ relations. Furthermore, drawing its value from repetition and constancy, the continuous attentional work that fragility requires performs a reparation that cannot be ‘settled’ once and for all. Far from fixing the state of things, maintenance inextricably participates in their becoming.
Algorithmic Food Justice
Authors: Houston Lara , Heitlinger Sara , Catlow Ruth , Taylor Alex
Published: October 2024

Under what technoscientific conditions might the scarcity of food be understood as contingent on heterogeneous actors? And how might the possibilities of food abundance be approached as a reparative project of valuing their manifold relations? Blockchain promises to be an infrastructure that presents both productive imaginaries and also challenges to such restorative and sustainable work. In a series of workshops, we critically experimented with these possibilities and challenges. Working with diverse participants including community growers, organizers, artists and technologists we used a variety of playful methods to act out fictional scenarios set in 2025, when all of London had been transformed into a city farm. For organizations and participants, reparation meant working in the aftermath of social and environmental collapse to bring into being more-than-human-value systems that radically decentred human knowledge and experience.
Being Affected by Páramo : Maps, Landscape Drawings and a Risky Science
Authors: Osejo Alejandra , Martínez-Medina Santiago
Published: October 2024

Building in a relationship between scientific artifacts and affect, we reflect on the possibilities of a crossing inspiration among sciences to inspire alternative forms of ecological repair. Colombian páramos are considered strategic ecosystems for water supply, pushing policies that have focused on partially prohibiting agriculture. Environmental authorities, supported by natural scientists, developed maps to delimit paramo, while social scientists studied the intimate relations between páramo and campesinos to inform the consequences of restrictions. We argue that the conservation of páramos requires repairing relationships beyond the páramo as "nature." The biodiversity sciences would benefit from participating in sophisticated conjunctions with other disciplines and campesino’s knowledge, which we imagine as ecologies of affections that feed sciences that risk novel articulations. One first step in this direction would be to learn to be affected by ‘inexact materials’; as landscape drawings that offer clues about affective worlds beyond those of science and the state.
Cincuenta años de desplazamiento forzado interno indígena en Chiapas, México. De conflictos políticoreligiosos a conflictos entre cárteles / Fifty Years of Forced Internal Displacement in Chiapas, Mexico: From Political-Religious Conflicts to Cartel Conflicts
Authors: Navarro-López América A.
Published: October 2024

resumen: Se realizó una investigación geográfica e histórica sobre el desplazamiento forzado interno (DFI) en Chiapas, México. El periodo analizado abarca desde 1970—cuando sectores de comunidades indígenas católicas no tradicionalistas y evangélicas fueron expulsados de municipios de Los Altos—hasta 2023, con los desplazamientos registrados principalmente en municipios de los límites entre México y Guatemala, como consecuencia de la disputa por el territorio entre cárteles, en medio de un militarismo y paramilitarismo que no ha cesado desde 1994. Desde un punto de vista conceptual, se recurre a la noción DFI, con la finalidad de explicar y comprender este tipo de movilidad humana a lo largo del tiempo, y cómo a partir de ella se ha reconstruido la territorialidad de las comunidades afectadas. Desde el punto de vista metodológico, se procesó la información obtenida de diversas fuentes en sistemas de información geográfica, la cual fue verificada en campo, tomando puntos GPS, lo que derivó en mapas que permitieron visualizar el incremento del DFI. La investigación es pertinente porque se aborda desde una aproximación poco utilizada para el estudio de este tipo de movilidad humana en Chiapas, y porque deja al descubierto cómo esta problemática ha sido invisibilizada a lo largo del tiempo, logrando construir bases de datos georreferenciadas sobre el tema, pioneras en su tipo a nivel nacional. abstract: Geographical and historical research was conducted on forced internal displacement (FID) in Chiapas, Mexico. The study covers the period from 1970, when some Catholic and evangelical indigenous communities were expelled from Los Altos municipalities, to 2023, which saw displacements in municipalities along the border, as a result of the territorial dispute waged between rival drug cartels, in the midst of militarism and paramilitarism that has not ceased since 1994. Conceptually, the notion of FID is used to explain and give meaning to this type of mobility over time, and how it has led to a reconstruction of the territoriality of affected communities. Methodologically, information obtained from various sources was processed in geographic information systems, and verified in the field with GPS. This mapping that visualized the increase in FID. This research is pertinent because it analyzes this type of mobility in Chiapas based on an approach that is rarely used and because it reveals how this problem was made invisible over time. It also built geo-referenced databases on the subject, the first of their type in Mexico.
GMDIC: a digital image correlation measurement method based on global matching for large deformation displacement fields
Authors: Wang Linlin , Shao Jing , Wang ZhuJun , Gao Qian , Wang ChuanYun , Yan Zhuo , Li ZhongYi , Zhang Tong
Published: October 2024

The digital image correlation method is a non-contact optical measurement method, which
has the advantages of full-field measurement, simple operation, and
high measurement accuracy. The traditional DIC method can accurately
measure displacement and strain fields, but there are still many
limitations. (i) In the measurement of large displacement
deformations, the calculation accuracy of the displacement field and
strain field needs to be improved due to the unreasonable setting of
parameters such as subset size and step size. (ii) It is
difficult to avoid under-matching or over-matching when reconstructing
smooth displacement or strain fields. (iii) When processing
large-scale image data, the computational complexity will be very
high, resulting in slow processing speeds. In recent years,
deep-learning-based DIC has shown promising capabilities in addressing
the aforementioned issues. We propose a new, to the best of our
knowledge, DIC method based on deep learning, which is designed for
measuring displacement fields of speckle images in complex large
deformations. The network combines the multi-head attention
Swin-Transformer and the high-efficient channel attention module ECA
and adds positional information to the features to enhance feature
representation capabilities. To train the model, we constructed a
displacement field dataset that conformed to the real situation and
contained various types of speckle images and complex deformations.
The measurement results indicate that our model achieves consistent
displacement prediction accuracy with traditional DIC methods in
practical experiments. Moreover, our model outperforms traditional DIC
methods in cases of large displacement scenarios.
Dequantenhancement by spatial color algorithms
Authors: Sarti Beatrice , Ramella Giuliana , Rizzi Alessandro
Published: October 2024

Spatial color algorithms (SCAs) are algorithms grounded in the retinex theory of color sensation that, mimicking the human visual system, perform image enhancement based on the spatial arrangement of the scene. Despite their established role in image enhancement, their potential as dequantizers has never been investigated. Here, we aim to assess the effectiveness of SCAs in addressing the dual objectives of color dequantization and image enhancement at the same time. To this end, we propose the term dequantenhancement. In this paper, through two experiments on a dataset of images, SCAs are evaluated through two distinct pathways: first, quantization followed by filtering to assess both dequantization and enhancement; and second, filtering applied to original images before quantization as further investigation of mainly the dequantization effect. The results are presented both qualitatively, with visual examples, and quantitatively, through metrics including the number of colors, retinal-like subsampling contrast (RSC), and structural similarity index (SSIM).
Enhanced force sensitivity based on Duffing nonlinearity in a dissipatively coupled optomechanical system
Authors: Zhu Ying-Jian , Han Xue , Wang Hong-Fu , Zhang Shou
Published: October 2024

The study of force sensitivity based on a cavity optomechanical system plays a prominent role in quantum precision measurement and provides an ideal platform for precision sensing technology. Here, we propose a scheme to enhance the force sensitivity of a dissipatively coupled optomechanical system by inducing Duffing nonlinearity. The numerical analysis shows that inducing Duffing nonlinearity significantly improves the force sensitivity compared to the system without Duffing nonlinearity, even surpassing the standard quantum limit (SQL) by more than five orders of magnitude. Moreover, we demonstrated that the sensitivity of force sensing is robust to temperature when Duffing nonlinearity is induced. More interestingly, the induction of Duffing nonlinearity broadens the detection bandwidth. At the same time, the detection frequency below the SQL also experiences a significant frequency shift with changes in the nonlinear amplitude. Our scheme not only holds potential for applications in quantum manipulation but also realizes macroscopic quantum effects.
Effects of multiple reflections on nonlinear absorption measurements
Authors: Prikhodko Victor V.
Published: October 2024

Accurate measurement of nonlinear absorption coefficients by transmission-based techniques, such as Z-scan and its modifications, remains challenging due to high measurement errors. In this Letter, we claim that one of the reasons for that could lie in ignoring multiple reflections of light in plane-parallel samples in the presence of multi-photon excitation. Closed-form formulations for transmittance and reflectance coefficients, considering both linear and multiphoton absorption, are obtained in the geometrical optics approximation. The contributions of multiple reflections to the total transmittance are calculated for several II–VI materials reported in the literature. The results show a nonlinear dependence on incident intensity, ranging from 15.7% down to 7.9% for CdS, from 10.3% down to 5.8% for CdSe, and from 18.1% down to 9.1% for ZnSe. The dependence of the contribution of multiple reflections on the sample thickness is shown to exhibit a near exponential decay.
High-speed 3D measurement using the kinoform array and light source shift
Authors: Wang Weichen , Zhan Jiandong , Shi Yile , Zhang Haihua , Ma Lihong , Xu Shutian , Li Yong
Published: October 2024

A new, to the best of our knowledge, fringe projector using the kinoform is proposed in this Letter. The kinoform array makes the hologram easy to manufacture, and the phase shift is realized by light source shift. The fringes can be shifted at a high speed due to the high-speed switch of the light source. An active binocular 3D measurement system using the proposed projector is demonstrated, and a binocular matching algorithm from coarse to fine using a laser speckle and fringe phase is proposed. Three laser diodes are adopted as light sources, and the three-step phase-shifting is achieved. The dimension of the projector is 30 mm × 26 mm × 12 mm and the switching speed is up to 1.5 kHz. The 3D measurement speed reaches 70 fps in the experiment.
Scanning multi-directional induction thermography
Authors: Marco Beñat Urtasun , Andonegui Imanol , Gorostegui-Colinas Eider
Published: October 2024

This paper presents a novel multi-directional induction thermography system for non-destructive testing (NDT). The system leverages inhomogeneous Joule heating from eddy currents, which vary based on magnetic field orientation, to distinguish defects from sound areas during continuous scanning. The system uses four coils wound around a quadratic ferrite core to sequentially induce eddy currents in multiple directions during a linear scan. The resulting thermography data is split temporally by field orientation, and a subsequent thermal drift compensation normalization is applied allowing for spatio-temporal analysis. Standard techniques like PCA and FFT are applied to these directional thermographies, and the results are fused to enhance defect detection by analyzing thermal signal variance. The method is validated on a steel billet with delamination and a forged steel bolt with surface cracking.
Wide-range Emission Wavelength Control of InAs Quantum Dots by Changing Indium Composition in InAlGaAs Partial Capping Layer
Authors: Kwoen Jinkwan , Kakuda Masahiro , Arakawa Yasuhiko
Published: October 2024

This study investigates the emission wavelength control of InAs quantum dots (QDs) grown on InP substrates using molecular beam epitaxy (MBE). By utilizing InAlGaAs partial capping layers with varying indium compositions, the emission wavelengths were tuned across the S, C, L, and U bands, making them applicable for optical communication. The use of lower indium content layers effectively reduced indium interdiffusion during the indium flush process, allowing precise emission wavelength control and strain compensation. These findings offer potential for advanced optical communication and photonics applications using high-quality InAs QDs on InP substrates.
Combination of graphene plasmons and surface plasmons in a crystalline Ge2Sb1.5Bi0.5Te5 metasurface structure for laser mode-locking
Authors: Wang Hongpei , Ye Lei , Wang Shun , Wang Jiqiang , Lyu Menglu , Qin Liang , Zhang Ziyang , Jiang Cheng
Published: October 2024

Owing to the dynamic tunability and strong confinement, graphene plasmons (GPs) have emerged as an excellent candidate for the manipulation of light–matter interaction. Surface plasmons (SPs) have been admitted as another effective way allowing strong confinement of light at the nanoscale. The combination of GPs and SPs like localized surface plasmons (LSPs) and propagating surface plasmon polaritons (SPPs) will lead to a synergistic effect that could remarkably improve light–matter interactions, showing great potential for many applications for the improvement of solar cell efficiency, biosensor sensitivity, and the performance of photonic devices. In this study, the GPs were activated by placing graphene film onto a two-dimensional (2D) phase-changing crystalline Ge2Sb1.5Bi0.5Te5 (cGSBT) nanograting structure, which also acts as an original source generating LSPs. The SPPs originated by laying the above structure onto an Au mirror. The combined effects of GPs, LSPs, and SPPs are epitomized in such a simple Gr/2D cGSBT gratings/Au heterostructure, which allows easy realization of an ultrafast mode-locked laser quite stable working at 1550 nm range due to the strong nonlinear optical absorption capability. This approach overcomes the heat and energy loss in metallic gratings or a Gr-based heterostructure, exhibiting great potential for applications in the design and fabrication of photonic devices.
100  nm broadband and ultra-compact multi-dimensional multiplexed photonic integrated circuit for high-capacity optical interconnects
Authors: Shen Ruoyu , Hu Fangchen , Hong Bingzhou , Wang Xin , Sun Aolong , Zhang Junwen , Zhao Haibing , Chi Nan , Chu Wei , Cai Haiwen , Huang Weiping
Published: October 2024

Chip-scale multi-dimensional multiplexing technology that combines wavelengths and spatial modes on a silicon photonic integrated circuit (PIC) is highly promising for the link-capacity scaling of future optical interconnects. However, current multi-dimensional multiplexed PICs face significant challenges in simultaneously achieving broad optical bandwidth, low mode crosstalk, and dual-polarization modes in an ultra-compact footprint as the number of spatial modes increases. To address the issue, a topology-optimization-based inverse design assisted by a novel manufacturing calibration method (MCM) is utilized. Based on a 220 nm silicon-on-insulator (SOI) platform, a 100 nm broadband and ultra-compact (6  μm×6  μm) multi-dimensional multiplexed PIC supporting TE0, TE1, TM0, and TM1 modes with modes crosstalk <−16dB ranging from 1500 to 1600 nm is demonstrated for the first time, to the best of our knowledge. Furthermore, the PIC is implemented to experimentally enable a single-wavelength 4-modes ×100  Gbit/s PAM-4 direct modulation data transmission over 51 wavelengths with 0.8 nm channel spacing. This work shows the potential of utilizing multi-dimensional multiplexed PICs as optical interconnects to effectively address the speed limits of data transfer for future high-performance chip-to-chip interconnection.
A multi-pathogen behavioral exposure model for young children playing in public spaces in developing communities
Authors: Houser Stephanie A. , Sewell Daniel K. , Medgyesi Danielle N. , Brogan John M. , Creve-Coeur Jean Philippe , Baker Kelly K.
Published: October 2024

Diarrheal disease is the second leading cause of death among children under five in developing communities, despite active interventions to improve access to water, sanitation, and hygiene resources. Even interventions with high fidelity and compliance saw minimal improvements in health outcomes, necessitating a need for looking beyond traditionally targeted exposure pathways. This study focuses on the pathogen exposure a young child may receive while playing in the public spaces of informal settlements, where animal feces, human feces, and garbage are frequently observed. The study utilized 79 soil samples previously collected across ten cluster sites in Corail, Haiti and processed using DelAgua cultural assays and quantitative Polymerase Chain Reaction methods. Molecular assays screened for Aeromonas, Vibrio cholera, and several pathogenic Escherichia coli species. Behavioral observations of young children (<5 years old) were also conducted in overlapping areas with the environmental sampling to quantify frequency of risky and mitigating behaviors. Environmental and behavioral data were combined to obtain the posterior distribution of children’s pathogen exposure from playing in a public space for one hour. The model estimated that children have a likelihood of approximately 70% of being exposed to a pathogen during one hour of play and a greater than 30% chance of being exposed to multiple pathogens in the same period. While children and toddlers practice fewer risky behaviors compared to infants, they were shown to have higher likelihood of exposure and slightly higher pathogen dose per exposure. As anticipated, a high correlation between genes from the same E. coli species was observed in the model output. These findings demonstrate the need to consider public spaces as an important exposure pathway for young children for both future research and interventions.