It’s no secret : the overtness of external support and rebel-civilian interactions in civil wars

Existe-t-il un lien entre le degré de publicité du soutien fourni par des États à des groupes rebelles et les relations entre les insurgés soutenus et les civils durant les guerres internes ? Les études sur les conflits examinent de plus en plus la manière dont un soutien étatique externe à des insurgés locaux façonne le comportement de ces derniers. Cependant, la littérature néglige l’influence de la décision des États-soutiens de nier ou reconnaître leur aide sur la conduite des rebelles. Divisée en trois parties, ma thèse de doctorat utilise une méthodologie mixte alliant analyses quantitatives et études de cas qualitatives pour combler cette lacune dans la littérature. L’Article 1 présente de nouvelles données sur le degré de publicité du soutien étatique aux rebelles durant les guerres civiles entre 1989 et 2018. Il montre ensuite que cette variable est négativement corrélée à la propension des insurgés à user de la violence envers les non-combattants. L’Article 2 commence par présenter une théorie expliquant comment, pourquoi et dans quelles circonstances les États-soutiens tentent-ils de superviser les interactions avec les non-combattants des insurgés qu’ils appuient lors des guerres civiles. Il applique ensuite ce cadre théorique au soutien des États-Unis aux Unités de protection du peuple (YPG) et aux Forces démocratiques syriennes (FDS) dans le nord-est de la Syrie entre 2014 et 2020. L’Article 3 montre qu’en plus d’être corrélé négativement à la violence rebelle envers les civils, le degré de publicité du soutien étatique aux insurgés est corrélé positivement à la propension de ces derniers à fournir des services à la population. Il nuance ensuite les résultats statistiques en montrant que l’existence d’institutions formelles de fourniture de services n’équivaut pas nécessairement à une participation effective des civils à l’exercice du pouvoir en zones rebelles. Ainsi, la thèse met en évidence le lien critique entre le degré de publicité du soutien étatique aux rebelles et les interactions entre insurgés soutenus et civils. Les résultats de recherche montrent dès lors que les expériences des non-combattants au cours de conflits qualifiés d’internes à un espace sont corrélés à des facteurs et intérêts liés à des acteurs externes à ce même territoire.What is the relationship between the overtness of state support to rebels and the nature of insurgent-civilian interactions during civil wars? Conflict studies increasingly examine how external support to local insurgents influences rebel behavior. However, the literature neglects the link between the state sponsors’ decisions to acknowledge or deny their support and insurgent behavior. My three-part doctoral dissertation uses a mixed-methods research design combining quantitative analyses and qualitative case studies to address this gap in the literature. Article 1 introduces new data on the overtness of external support to rebels during civil wars between 1989 and 2018. The paper then shows that this variable negatively correlates with the propensity of the insurgents to target civilians. Article 2 begins by outlining a theory of how, why, and when the state sponsors monitor the interactions with civilians of the insurgents they support. The paper then applies this theoretical framework to the United States’ (US) support for the People’s Defense Units (YPG) and the Syrian Democratic Forces (SDF) in Northeast Syria between 2014 and 2020. Article 3 shows that in addition to negatively correlating with civilian targeting, the overtness of external support to rebels positively correlates with the propensity of the insurgents to provide social services during civil wars. The paper then qualifies the statistical results by showing that the creation of formal social service institutions by the rebels does not necessarily lead to effective civilian participation in decision-making in insurgent areas. The dissertation thus highlights the critical link between the overtness of state support to rebels and the insurgent-civilian interactions. In this way, I show that civilian experiences during conflicts we characterize as internal to a territory correlate with factors and interests linked to external actors

Dimensionality reduction beyond neural subspaces with slice tensor component analysis

Recent work has argued that large-scale neural recordings are often well described by patterns of coactivation across neurons. Yet the view that neural variability is constrained to a fixed, low-dimensional subspace may overlook higher-dimensional structure, including stereotyped neural sequences or slowly evolving latent spaces. Here we argue that task-relevant variability in neural data can also cofluctuate over trials or time, defining distinct ‘covariability classes’ that may co-occur within the same dataset. To demix these covariability classes, we develop sliceTCA (slice tensor component analysis), a new unsupervised dimensionality reduction method for neural data tensors. In three example datasets, including motor cortical activity during a classic reaching task in primates and recent multiregion recordings in mice, we show that sliceTCA can capture more task-relevant structure in neural data using fewer components than traditional methods. Overall, our theoretical framework extends the classic view of low-dimensional population activity by incorporating additional classes of latent variables capturing higher-dimensional structure

Fracture behaviour and damage characterisation in composite impact panels by laboratory X-ray computed tomography

<p>Presentation from Thermosets 2013, From Monomers to Components Conference in Berlin, Germany 16-18 September 2013.</p

Cold, Northern Winters: The Importance of Temperature to Overwinter Mortality of Age-0 White Crappies

Survival during the first winter of life can influence the recruitment of many fishes. We used field sampling and laboratory experiments to explore the mechanisms underlying first winter growth and survival of white crappie Pomoxis annularis, which exhibits variable recruitment. We sampled age-0 white crappies from four Ohio reservoirs before winter to evaluate whether large individuals had a greater energy density (kJ/g) than small ones and whether mean energy density differed among reservoirs. Energy density increased with fish size in all reservoirs, suggesting that small fish could die earlier if energy stores become limiting during winter. Mean energy density varied among reservoirs as well, suggesting that prewinter energy reserves could influence recruitment variability across reservoirs through their effects on winter starvation. Our laboratory experiment evaluated how fish size (small or large), feeding level (starved or fed), and winter severity (mild or severe) interact to influence the growth and survival of age-0 white crappies. The two winter severity treatments represented two extremes for Ohio winters (i.e., mild and severe). We calculated daily individual growth rates for all fish, energy density for a subset of fish, and percent survival across treatments. Winter severity strongly influenced survival: only 47% of all white crappies survived the severe winter, whereas 97% survived the mild winter. In the severe winter, neither size nor feeding level influenced mortality. Bomb calorimetry revealed energy density to be similar among fish that died and those that survived the severe winter, suggesting that energy depletion did not cause mortality. Rather, osmoregulatory failure may have occurred during exposure to temperatures colder than 4°C for at least 1 week. Thus, the availability of warm (≥4°C), oxygenated water during winter may be critical to the survival of age-0 white crappies. In the northern portion of their range, winter temperatures may account for some of the recruitment variability common to white crappie populations.This research was funded by Federal Aid in Sport Fish Restoration Project F-69-P, administered jointly by U.S. Fish and Wildlife Service and Ohio Department of Natural Resources, Division of Wildlife, and the Department of Evolution, Ecology, and Organismal Biology at the Ohio State University

Conversion of the Bayou Choctaw geological site characterization report to a three-dimensional model.

The geologic model implicit in the original site characterization report for the Bayou Choctaw Strategic Petroleum Reserve Site near Baton Rouge, Louisiana, has been converted to a numerical, computer-based three-dimensional model. The original site characterization model was successfully converted with minimal modifications and use of new information. The geometries of the salt diapir, selected adjacent sedimentary horizons, and a number of faults have been modeled. Models of a partial set of the several storage caverns that have been solution-mined within the salt mass are also included. Collectively, the converted model appears to be a relatively realistic representation of the geology of the Bayou Choctaw site as known from existing data. A small number of geometric inconsistencies and other problems inherent in 2-D vs. 3-D modeling have been noted. Most of the major inconsistencies involve faults inferred from drill hole data only. Modem computer software allows visualization of the resulting site model and its component submodels with a degree of detail and flexibility that was not possible with conventional, two-dimensional and paper-based geologic maps and cross sections. The enhanced visualizations may be of particular value in conveying geologic concepts involved in the Bayou Choctaw Strategic Petroleum Reserve site to a lay audience. A Microsoft WindowsTM PC-based viewer and user-manipulable model files illustrating selected features of the converted model are included in this report

Conversion of the Bryan Mound geological site characterization reports to a three-dimensional model.

The Bryan Mound salt dome, located near Freeport, Texas, is home to one of four underground crude oil-storage facilities managed by the U. S. Department of Energy Strategic Petroleum Reserve (SPR) Program. Sandia National Laboratories, as the geotechnical advisor to the SPR, conducts site-characterization investigations and other longer-term geotechnical and engineering studies in support of the program. This report describes the conversion of two-dimensional geologic interpretations of the Bryan Mound site into three-dimensional geologic models. The new models include the geometry of the salt dome, the surrounding sedimentary units, mapped faults, and the 20 oil-storage caverns at the site. This work provides an internally consistent geologic model of the Bryan Mound site that can be used in support of future work

Conversion of the Big Hill geological site characterization report to a three-dimensional model.

The Big Hill salt dome, located in southeastern Texas, is home to one of four underground oil-storage facilities managed by the U. S. Department of Energy Strategic Petroleum Reserve (SPR) Program. Sandia National Laboratories, as the geotechnical advisor to the SPR, conducts site-characterization investigations and other longer-term geotechnical and engineering studies in support of the program. This report describes the conversion of two-dimensional geologic interpretations of the Big Hill site into three-dimensional geologic models. The new models include the geometry of the salt dome, the surrounding sedimentary units, mapped faults, and the 14 oil storage caverns at the site. This work provides a realistic and internally consistent geologic model of the Big Hill site that can be used in support of future work

Three-dimensional representations of salt-dome margins at four active strategic petroleum reserve sites.

Existing paper-based site characterization models of salt domes at the four active U.S. Strategic Petroleum Reserve sites have been converted to digital format and visualized using modern computer software. The four sites are the Bayou Choctaw dome in Iberville Parish, Louisiana; the Big Hill dome in Jefferson County, Texas; the Bryan Mound dome in Brazoria County, Texas; and the West Hackberry dome in Cameron Parish, Louisiana. A new modeling algorithm has been developed to overcome limitations of many standard geological modeling software packages in order to deal with structurally overhanging salt margins that are typical of many salt domes. This algorithm, and the implementing computer program, make use of the existing interpretive modeling conducted manually using professional geological judgement and presented in two dimensions in the original site characterization reports as structure contour maps on the top of salt. The algorithm makes use of concepts of finite-element meshes of general engineering usage. Although the specific implementation of the algorithm described in this report and the resulting output files are tailored to the modeling and visualization software used to construct the figures contained herein, the algorithm itself is generic and other implementations and output formats are possible. The graphical visualizations of the salt domes at the four Strategic Petroleum Reserve sites are believed to be major improvements over the previously available two-dimensional representations of the domes via conventional geologic drawings (cross sections and contour maps). Additionally, the numerical mesh files produced by this modeling activity are available for import into and display by other software routines. The mesh data are not explicitly tabulated in this report; however an electronic version in simple ASCII format is included on a PC-based compact disk