Hasil untuk "Geography (General)"

V. Gupta, Sandip Paul, C. Dutta

One of the fundamental issues in the microbiome research is characterization of the healthy human microbiota. Recent studies have elucidated substantial divergences in the microbiome structure between healthy individuals from different race and ethnicity. This review provides a comprehensive account of such geography, ethnicity or life-style-specific variations in healthy microbiome at five major body habitats—Gut, Oral-cavity, Respiratory Tract, Skin, and Urogenital Tract (UGT). The review focuses on the general trend in the human microbiome evolution—a gradual transition in the gross compositional structure along with a continual decrease in diversity of the microbiome, especially of the gut microbiome, as the human populations passed through three stages of subsistence like foraging, rural farming and industrialized urban western life. In general, gut microbiome of the hunter-gatherer populations is highly abundant with Prevotella, Proteobacteria, Spirochaetes, Clostridiales, Ruminobacter etc., while those of the urban communities are often enriched in Bacteroides, Bifidobacterium, and Firmicutes. The oral and skin microbiome are the next most diverse among different populations, while respiratory tract and UGT microbiome show lesser variations. Higher microbiome diversity is observed for oral-cavity in hunter-gatherer group with higher prevalence of Haemophilus than agricultural group. In case of skin microbiome, rural and urban Chinese populations show variation in abundance of Trabulsiella and Propionibacterium. On the basis of published data, we have characterized the core microbiota—the set of genera commonly found in all populations, irrespective of their geographic locations, ethnicity or mode of subsistence. We have also identified the major factors responsible for geography-based alterations in microbiota; though it is not yet clear which factor plays a dominant role in shaping the microbiome—nature or nurture, host genetics or his environment. Some of the geographical/racial variations in microbiome structure have been attributed to differences in host genetics and innate/adaptive immunity, while in many other cases, cultural/behavioral features like diet, hygiene, parasitic load, environmental exposure etc. overshadow genetics. The ethnicity or population-specific variations in human microbiome composition, as reviewed in this report, question the universality of the microbiome-based therapeutic strategies and recommend for geographically tailored community-scale approaches to microbiome engineering.

J. Eaton, Samuel Kortum

E. Curtis, R. Y. van der Velde, R. Moon et al.

Pol Antràs, Alonso de Gortari

This paper develops a multi‐stage general‐equilibrium model of global value chains (GVCs) and studies the specialization of countries within GVCs in a world with barriers to international trade. With costly trade, the optimal location of production of a given stage in a GVC is not only a function of the marginal cost at which that stage can be produced in a given country, but is also shaped by the proximity of that location to the precedent and the subsequent desired locations of production. We show that, other things equal, it is optimal to locate relatively downstream stages of production in relatively central locations. We also develop and estimate a tractable, quantifiable version of our model that illustrates how changes in trade costs affect the extent to which various countries participate in domestic, regional, or global value chains, and traces the real income consequences of these changes.

Yixian Chen, Sofie De Geeter, Jean Poesen et al.

Gully formation is a significant driver of soil erosion and land degradation worldwide and often leads to important downstream impacts. Nonetheless, our understanding of the global patterns and the factors controlling this process remains limited. Here, we present the first global assessment of gully density's spatial patterns. Using mapped observations from over 17,000 representative study sites worldwide, we trained random forest models that simulate both the susceptibility to gullying at a 1 km2 resolution and the corresponding gully head density (GHD). Through an interpretable machine learning framework, we demonstrate that global GHD patterns result from a combination of environmental factors with non-linear interactions, leading to significant regional variations in the dominant factors controlling GHD. We distinguish between gully hotspots driven primarily by natural factors such as topography, geomorphology, tectonics, pedology or climate and those where land use and land cover play a dominant role. Based on these insights, we identified critical global areas of gully erosion, i.e., hotspots where gully occurrence is likely highly sensitive to anthropogenic drivers. These include the Chinese Loess Plateau, the Ethiopian Highlands, and large parts of the Mediterranean and Sahel regions. Also desert regions are often characterized by high GHDs. However, in these cases, their occurrence is mainly driven by natural factors. The insights we provide are valuable to inform land management and targeted erosion mitigation strategies.

Nicolas Donner

This paper considers the ways of establishing oil enclaves in difficult environments and it focuses on procedures that aim to safeguard the extractive activity from external disturbance and/or hostility. First, in addressing the case of enclaves located in extreme environments (hostile to life), we show that the organization of enclaves is an important tool of their immunization: by producing an inclusive and autonomous space, an "architecture of vacuum "(Sloterdijk) allows to free the activity from the conditions and contingencies of the external environment. Secondly, we move to the case of enclaves established in environments that are inhabited and territorialized, where immunization procedures are enriched by defensive (fencing) and intrusive mechanisms (sustainable practices). Finally we discuss the emergence of an ethical paradigm that tangled in strategies that aim to ensure the continuity of extractive activities.

Lu Zhou, Qingli Zhang, Huihuan Luo et al.

To investigate the association of long-term exposure to air pollution with incident arrhythmia from various causes, this prospective cohort study included 442,386 participants from the UK Biobank cohort. Residential annual average exposures at baseline were evaluated, including fine particles (PM2.5), coarse particles (PM2.5–10), nitrogen dioxide (NO2), and nitrogen oxides (NOx). We further constructed a composite air pollution score (APS) to evaluate the concomitant exposure to these four pollutants. The associations of air pollutants with various arrhythmia subtypes were assessed utilizing the Cox proportional hazards model, and the hazard ratios (HRs) for incident arrhythmias were estimated. A total of 41,021 patients with incident arrhythmia were recorded. The HRs of overall arrhythmia associated with a 10 μg/m3 increment in PM2.5, PM2.5–10, NO2, and NOx were 1.26, 0.95, 1.03, and 1.02, respectively. The HR was 1.08 in the highest quintile of the APS compared to the lowest one. For cause-specific arrhythmias, the HRs per unit increment in APS were 1.45, 1.67, 1.51, 1.80, 2.63, and 4.66 for atrial fibrillation, atrioventricular block, ventricular fibrillation/tachycardia, intraventricular block, supraventricular tachycardia, and ventricular premature beats, respectively. Females, older individuals, overweight or obese individuals, and those with low education attainment, low income, or cardiometabolic morbidities had higher HRs associated with pollutants. Long-term exposure to air pollution is linked to increased incidence risks of atrial and ventricular arrhythmias. More focus should be shifted to the impact of air pollution on other arrhythmias besides atrial fibrillation.

Michel Waly DIOUF

Cet article examine la réutilisation des coquillages fossiles et décrit en même temps les anomalies ou les déformations observées sur les individus. La démarche adoptée repose en effet sur une combinaison de plusieurs activités allant de la recherche documentaire à l’examen du mobilier coquillier, en passant par les enquêtes ethnographiques, la prospection et les fouilles archéologiques. Nos fouilles effectuées sur le site de Balloum, près du village de Moundé (basSaloum) ont mis au jour des spécimens coquilliers déformés ou réutilisés le plus souvent en des objets de parures ou d’ustensiles. Mots-clés : ,

Kazuki Sakamoto, Connor T. Jerzak, Adel Daoud

Earth observation (EO) data such as satellite imagery can have far-reaching impacts on our understanding of the geography of poverty, especially when coupled with machine learning (ML) and computer vision. Early research used computer vision to predict living conditions in areas with limited data, but recent studies increasingly focus on causal analysis. Despite this shift, the use of EO-ML methods for causal inference lacks thorough documentation, and best practices are still developing. Through a comprehensive scoping review, we catalog the current literature on EO-ML methods in causal analysis. We synthesize five principal approaches to incorporating EO data in causal workflows: (1) outcome imputation for downstream causal analysis, (2) EO image deconfounding, (3) EO-based treatment effect heterogeneity, (4) EO-based transportability analysis, and (5) image-informed causal discovery. Building on these findings, we provide a detailed protocol guiding researchers in integrating EO data into causal analysis -- covering data requirements, computer vision model selection, and evaluation metrics. While our focus centers on health and living conditions outcomes, our protocol is adaptable to other sustainable development domains utilizing EO data.

E. Smit, Hanneke Tuithof, E. Savelsbergh et al.

Abstract Pedagogical Content Knowledge (PCK) is the knowledge teachers use to teach a specific subject to a specific audience. The importance of PCK to quality teaching is widely recognized. However, an overview of research about geography teachers’ PCK is missing. To fill this gap, we conducted a systematic review. We analyzed 43 empirical studies, but only 9 used PCK as a framework. Most studies addressed instructional strategies or teaching orientations. The studies were too diverse to draw conclusions on geography teachers’ PCK in general. But portraits of 16 geography teachers emphasized the necessity of geographical knowledge and teaching experience for PCK-quality.

C. Ducruet

Despite early cartographical and graph-theoretical analyses of maritime flows in the 1940s and 1960s, it is only from the 2000s onwards that maritime network analysis had grown apace, backed by newly available shipping data, increased computational power, and renewed conceptual frameworks to study networks in general. The evolution of maritime network analysis, in geography and other sciences, is marked by a wide diversity of methods and themes, which we classify into three main parts. We first present studies looking at maritime flows in an abstract space, focusing on operational, statistical, or managerial aspects where navigation, graph structure, and firms' strategies are the key concerns. Second, we review researches where maritime flows and networks are markers and vectors of wider geo-economic structures and dynamics, such as regional inequalities and areas of dominance. Lastly, maritime networks have also been considered as integral parts of territories and wider chained systems, such as urban networks, regional networks, and coupled networks. We conclude that network analysis and maritime transport still share many uncovered areas and discuss potential research pathways for future works.

Evan Cleave, Cailin Wark, Emmanuel Kyeremeh

For cities, immigration is now considered a vital part of local economic and community development. Over the past half-century, many cities have experienced a series challenges caused by the impacts of late-stage demographic transition; the slow bleeding of skilled domestic workers to larger metropolitan areas; and the decline of traditional economic sectors. As a result, there has been a prioritization of attracting and retaining high-skilled and well-educated immigrants by local governments through locally-focused, place-based policies. Within this context, this paper examines the ways that cities in the Province of Ontario, Canada are constructing and implementing immigrant attraction, integration, and retention strategies. To achieve this goal, we identified and examined the local immigration policies of the 52 cities in Ontario, 36 of which have a formal immigration policy document. A comprehensive content analysis was conducted on these available to identify the ways that immigration is conceptualized, and the specific policies and approaches that local governments are implementing. Statistical analysis was used to determine if there was variation in policy across different types of cities. Based on this analysis, local governments are generally developing holistic, place-based policies – however, there is variation in approaches across cities of different sizes and geographies. These place-specific policies draw on local assets and advantages (i.e. existing migrant communities; local amenities and attractions; economic and education opportunities) while also work to enhance enhancing local capacity (i.e. building networks and immigration partnerships; training employers and city workers).

Song Gao

This paper examines the recent advances and applications of AI in human geography especially the use of machine (deep) learning, including place representation and modeling, spatial analysis and predictive mapping, and urban planning and design. AI technologies have enabled deeper insights into complex human-environment interactions, contributing to more effective scientific exploration, understanding of social dynamics, and spatial decision-making. Furthermore, human geography offers crucial contributions to AI, particularly in context-aware model development, human-centered design, biases and ethical considerations, and data privacy. The synergy beween AI and human geography is essential for addressing global challenges like disaster resilience, poverty, and equitable resource access. This interdisciplinary collaboration between AI and geography will help advance the development of GeoAI and promise a better and sustainable world for all.

M. Schweizer, N. Straumann, A. Wipf

We adapt the post-Newtonian gravitational-radiation methods developed within general relativity by Epstein and Wagoner to the gravitation theory with torsion, recently proposed by Hehl et al., and show that the two theories predict in this approximation the same gravitational radiation losses. Since they agree also on the first post-Newtonian level, they are at the present time - observationally - indistinguishable.

Yerko Torres-Nova

Roughly speaking, the problem of geography asks for the existence of varieties of general type after we fix some invariants. In dimension $1$, where we fix the genus, the geography question is trivial, but already in dimension $2$, it becomes a hard problem in general. In higher dimensions, this problem is essentially wide open. In this paper, we focus on geography in dimension $3$. We generalize the techniques which compare the geography of surfaces with the geography of arrangements of curves via asymptotic constructions. In dimension $2$ this involves resolutions of cyclic quotient singularities and a certain asymptotic behavior of the associated Dedekind sums and continued fractions. We discuss the general situation with emphasis on dimension $3$, analyzing the singularities and various resolutions that show up, and proving results about the asymptotic behavior of the invariants we fix.

Yin Ching Lai

Hong Kong' senior geography curriculum has included GIS since the early 2000s. However, GIS in secondary schools does not play a significant role in Hong Kong secondary geography education. Analyzing GIS benefits by literature review, it is believed that GIS should be included in both the senior and junior geography curriculum. Moreover, the literature review indicates that without clear instruction from the Hong Kong Education Bureau (EDB), low preparedness of Hong Kong geography teachers, and unsupportive attitudes from academia and textbook publishers, GIS cannot be implemented in secondary schools of Hong Kong. Therefore, suggestions are made for the EDB, geography teachers, academia and textbook publishers to facilitate GIS involvement in senior and junior geography curriculums. The EDB can develop clear guidelines for teachers, academia and textbook publishers' references, and offer student-centered GIS educational courses for teachers. It is important for teachers to be prepared for advanced GIS technology and to even learn along with students. Academics and textbook publishers can provide free GIS maps targeted at Hong Kong' junior and senior geography curriculums. Although the report provides brief information towards the GIS implementation in Hong Kong geography education, it can inspire new ideas from other scholars to facilitate the usage of GIS in Hong Kong secondary school geography teaching.

Joel Klinger, J. Mateos-Garcia, Konstantinos Stathoulopoulos

Mokras-Grabowska Justyna, Mroczek-Żulicka Aleksandra, Olasik Marta

This article is an attempt at investigating new meanings and significance of computer-based entertainment during the COVID-19 pandemic. The authors explore how and to what extent students in Poland have been using electronics for entertainment during the global crisis, what emotions appeared and whether they were able and willing to engage in an auto-reflexive process. The article presents the results of the questionnaire interview designed for the purposes of this particular study. The authors chose to reveal the multi-facetedness of the theme in question, i.e. focus on the possibilities and the future that computer-based etertainment offers, leading to transformations both externally and internally.

Indrajeet MALLICK, Daniel MIRAVET, Aaron GUTIÉRREZ

The impact of the COVID-19 on tourist satisfaction is a particular relevant issue, due to the role that elements such as the prevention measures implemented at the destination might play. For this reason, this article examines tourist satisfaction during the peak tourist season of 2020 in a mature coastal destination in Catalonia in relation to safety and prevention measures imposed due to the COVID-19 pandemic. We use explanatory factor analysis and partial least squares path modelling for comparing the determinants of tourist satisfaction prior and during the pandemic based on surveys conducted in 2019 (N = 1556) and 2020 (N = 2220). The results suggest that the determinants of overall tourist satisfaction in 2019 remained significant in 2020. Moreover, although tourists especially appreciated feeling safe in 2020, our results suggest that such a perception was unrelated to measures to prevent COVID-19. The paper raises concerns towards the management of situations such as the pandemic in tourist destinations, as a proper balance must be found between the need of making visitors feel safe, and avoiding measures that can be felt as invasive or annoying, hampering the tourist experience.

Kirana Widyastuti, Kirana Widyastuti, Romain Reuillon et al.

Agent-based models have been developed and widely employed to assess the impact of disturbances or conservation management on animal habitat use, population development, and viability. However, the direct impacts of canopy disturbance on the arboreal movement of individual primates have been less studied. Such impacts could shed light on the cascading effects of disturbances on animal health and fitness. Orangutans are an arboreal primate that commonly encounters habitat quality deterioration due to land-use changes and related disturbances such as forest fires. Forest disturbance may, therefore, create a complex stress scenario threatening orangutan populations. Due to forest disturbances, orangutans may adapt to employ more terrestrial, as opposed to arboreal, movements potentially prolonging the search for fruiting and nesting trees. In turn, this may lead to changes in daily activity patterns (i.e., time spent traveling, feeding, and resting) and available energy budget, potentially decreasing the orangutan's fitness. We developed the agent-based simulation model BORNEO (arBOReal aNimal movEment mOdel), which explicitly describes both orangutans' arboreal and terrestrial movement in a forest habitat, depending on distances between trees and canopy structures. Orangutans in the model perform activities with a motivation to balance energy intake and expenditure through locomotion. We tested the model using forest inventory data obtained in Sebangau National Park, Central Kalimantan, Indonesia. This allowed us to construct virtual forests with real characteristics including tree connectivity, thus creating the potential to expand the environmental settings for simulation experiments. In order to parameterize the energy related processes of the orangutans described in the model, we applied a computationally intensive evolutionary algorithm and evaluated the simulation results against observed behavioral patterns of orangutans. Both the simulated variability and proportion of activity budgets including feeding, resting, and traveling time for female and male orangutans confirmed the suitability of the model for its purpose. We used the calibrated model to compare the activity patterns and energy budgets of orangutans in both natural and disturbed forests . The results confirm field observations that orangutans in the disturbed forest are more likely to experience deficit energy balance due to traveling to the detriment of feeding time. Such imbalance is more pronounced in males than in females. The finding of a threshold of forest disturbances that affects a significant change in activity and energy budgets suggests potential threats to the orangutan population. Our study introduces the first agent-based model describing the arboreal movement of primates that can serve as a tool to investigate the direct impact of forest changes and disturbances on the behavior of species such as orangutans. Moreover, it demonstrates the suitability of high-performance computing to optimize the calibration of complex agent-based models describing animal behavior at a fine spatio-temporal scale (1-m and 1-s granularity).