bluuebunny/crossref_metadata_2025 huggingface dataset:
Superconducting properties of NbN film, bridge and meanders
Authors: Joshi Lalit M. , Verma Apoorva , Gupta Anurag , Rout P. K. , Husale Sudhir , Budhani R. C.
Published: May 2018

The transport properties of superconducting NbN nanostructures in the form of thin film, bridge of width (w) = 50 μm and three meanders of w = 500, 250 and 100 nm have been investigated by resistance (R) measurements in temperature (T) range = 2 -300 K and magnetic field (B) range = 0 - 7 Tesla. The nanostructuring was carried out using Focused Ion Beam (FIB) milling. Reduction of sample width results in significant changes in the normal and superconducting state properties. For instance, the observed metallic behavior in the thin film sample is lost and the normal state resistance increases drastically from 2.4 Ω to 418 kΩ for the 100 nm meander. In the superconducting state, the value of critical temperature Tc (upper critical field Bc2 at T = 0 K) reduces gradually with width reduction, it changes from 13.15 K (42.8 Tesla) in the case of thin film sample to 5.7 K (12.7 Tesla) for the 100 nm meander sample. The superconducting transitions are found to get broader for the bridge sample and the meanders additionally show low-temperature resistive tails. In case of all the samples with reduced width, the transition onsets are found to be rounded at surprisingly high values of T ∼ 25 K >> Tc. These results are discussed in terms of the possible effects of FIB processing and weak localization in our samples.
Frequency dependent polarisation switching in h-ErMnO3
Authors: Ruff Alexander , Li Ziyu , Loidl Alois , Schaab Jakob , Fiebig Manfred , Cano Andres , Yan Zewu , Bourret Edith , Glaum Julia , Meier Dennis , Krohns Stephan
Published: May 2018

We report an electric-field poling study of the geometrically-driven improper ferroelectric h-ErMnO3. From a detailed dielectric analysis, we deduce the temperature and the frequency dependent range for which single-crystalline h-ErMnO3 exhibits purely intrinsic dielectric behaviour, i.e., free from the extrinsic so-called Maxwell-Wagner polarisations that arise, for example, from surface barrier layers. In this regime, ferroelectric hysteresis loops as a function of frequency, temperature, and applied electric fields are measured, revealing the theoretically predicted saturation polarisation on the order of 5–6 μC/cm2. Special emphasis is put on frequency dependent polarisation switching, which is explained in terms of domain-wall movement similar to proper ferroelectrics. Controlling the domain walls via electric fields brings us an important step closer to their utilization in domain-wall-based electronics.
Cascaded chirped photon acceleration for efficient frequency conversion
Authors: Edwards Matthew R. , Qu Kenan , Jia Qing , Mikhailova Julia M. , Fisch Nathaniel J.
Published: May 2018

A cascaded sequence of photon acceleration stages using the instantaneous creation of a plasma density gradient by flash ionization allows the generation of coherent and chirped ultraviolet and x-ray pulses with independently tunable frequency and bandwidth. The efficiency of the cascaded process scales with 1/ω in energy, and multiple stages produce significant frequency up-conversion with gas-density plasmas. Chirping permits subsequent pulse compression to few-cycle durations, and output frequencies are not limited to integer harmonics.
Wavefront division digital holography
Authors: Zhang Wenhui , Cao Liangcai , Li Rujia , Zhang Hua , Zhang Hao , Jiang Qiang , Jin Guofan
Published: May 2018

Digital holography (DH), mostly Mach-Zehnder configuration based, belongs to non-common path amplitude splitting interference imaging whose stability and fringe contrast are environmental sensitive. This paper presents a wavefront division DH configuration with both high stability and high-contrast fringes benefitting from quasi common path wavefront-splitting interference. In our proposal, two spherical waves with similar curvature coming from the same wavefront are used, which makes full use of the physical sampling capacity of the detectors. The interference fringe spacing can be adjusted flexibly for both in-line and off-axis mode due to the independent modulation to these two waves. Only a few optical elements, including the mirror-beam splitter interference component, are used without strict alignments, which makes it robust and easy-to-implement. The proposed wavefront division DH promotes interference imaging physics into the practical and miniaturized a step forward. The feasibility of this method is proved by the imaging of a resolution target and a water flea.
Optimization design of wireless charging system for autonomous robots based on magnetic resonance coupling
Authors: Wang Junhua , Hu Meilin , Cai Changsong , Lin Zhongzheng , Li Liang , Fang Zhijian
Published: May 2018

Wireless charging is the key technology to realize real autonomy of mobile robots. As the core part of wireless power transfer system, coupling mechanism including coupling coils and compensation topology is analyzed and optimized through simulations, to achieve stable and practical wireless charging suitable for ordinary robots. Multi-layer coil structure, especially double-layer coil is explored and selected to greatly enhance coupling performance, while shape of ferrite shielding goes through distributed optimization to guarantee coil fault tolerance and cost effectiveness. On the basis of optimized coils, primary compensation topology is analyzed to adopt composite LCL compensation, to stabilize operations of the primary side under variations of mutual inductance. Experimental results show the optimized system does make sense for wireless charging application for robots based on magnetic resonance coupling, to realize long-term autonomy of robots.
Effects of autotrophic biomass and composition on photosynthesis, respiration and light utilisation efficiency for a tropical savanna river
Authors: Townsend Simon A. , Webster Ian T. , Burford Michele A. , Schult Julia
Published: May 2018

The efficiency of light used for photosynthesis, when standardised for areal chlorophyll (Chl)-a biomass, is summarised by the light utilisation efficiency parameter and is dependent on light at the water’s surface, the underwater light climate and autotroph characteristics. Herein we examined the relationships between light, photosynthesis, respiration and autotroph biomass in a tropical savanna river in northern Australia during the dry season when autotroph biomass accumulated following wet season disturbance. The river’s autotrophs comprised mainly benthic microalgae, macroalgae and macrophytes. Total Chl-a and dry weight biomasses increased 4- and 27-fold respectively over 5 months, whereas photosynthesis doubled. Photosynthesis was light limited and, when standardised for Chl-a and dry weight biomasses, declined with increasing biomass, despite increasing incident light through the study period. We surmised this was due to self-shading and autotrophic composition, which had variable Chl-a content and resulted in a 10-fold reduction in the light utilisation efficiency with increasing light and biomass. Because respiration was tightly coupled to photosynthesis, biomass-standardised respiration also decreased with increasing biomass. Autotrophic self-shading and composition can have significant effects on light utilisation efficiency and the biomass–photosynthesis relationship, and warrant consideration when interpreting photosynthesis for river health monitoring.
Language debate and visions of the future in revolutionary Dagestan
Authors: Sahakyan Naira
Published: May 2018

The collapse of the old order in the Russian Empire in 1917 gave an opportunity to intellectuals on imperial borders to draft and implement their own visions of the future. The language debate in Dagestan was crucial in these plans given the multi-national character of the country. While Muslim scholars agreed on the importance of language, their opinions differed in the choice of Arabic, Turkic, various Dagestani languages or Russian. On the basis of Muslim periodicals, historical tracts of the period and official reports of political meetings, this paper examines the positions of Dagestaniʿulamāʾon the political significance of language. I argue that at a time of revolution different concepts of the state demanded a certain language profile at schools. There is a direct link between the choice of a political project and a preferred language of instruction.
P2Y1 receptor blockade normalizes network dysfunction and cognition in an Alzheimer’s disease model
Authors: Reichenbach Nicole , Delekate Andrea , Breithausen Björn , Keppler Kevin , Poll Stefanie , Schulte Theresa , Peter Jan , Plescher Monika , Hansen Jan N. , Blank Nelli , Keller Armin , Fuhrmann Martin , Henneberger Christian , Halle Annett , Petzold Gabor C.
Published: May 2018

Astrocytic hyperactivity is an important contributor to neuronal-glial network dysfunction in Alzheimer’s disease (AD). We have previously shown that astrocyte hyperactivity is mediated by signaling through the P2Y1 purinoreceptor (P2Y1R) pathway. Using the APPPS1 mouse model of AD, we here find that chronic intracerebroventricular infusion of P2Y1R inhibitors normalizes astroglial and neuronal network dysfunction, as measured by in vivo two-photon microscopy, augments structural synaptic integrity, and preserves hippocampal long-term potentiation. These effects occur independently from β-amyloid metabolism or plaque burden but are associated with a higher morphological complexity of periplaque reactive astrocytes, as well as reduced dystrophic neurite burden and greater plaque compaction. Importantly, APPPS1 mice chronically treated with P2Y1R antagonists, as well as APPPS1 mice carrying an astrocyte-specific genetic deletion (Ip3r2−/−) of signaling pathways downstream of P2Y1R activation, are protected from the decline of spatial learning and memory. In summary, our study establishes the restoration of network homoeostasis by P2Y1R inhibition as a novel treatment target in AD.
Fracture Toughness (KIC) of Lithography Based Manufactured Alumina Ceramic
Authors: Nindhia T. G. T. , Schlacher J. , Lube T.
Published: May 2018

Precision shaped ceramic components can be obtained by an emerging technique called Lithography based Ceramic Manufacturing (LCM). A green part is made from a slurry consisting of a ceramic powder in a photocurable binder with addition of dispersant and plasticizer. Components are built in a layer–by-layer way by exposing the desired cross- sections to light. The parts are subsequently sintered to their final density. It is a challenge to produce ceramic component with this method that yield the same mechanical properties in all direction. The fracture toughness (KIc) of of LCM-alumina (prepared at LITHOZ GmbH, Austria) was tested by using the Single-Edge-V-Notched Beam (SEVNB) method. Notches are made into prismatic bend-bars in all three direction X, Y and Z to recognize the value of fracture toughness of the material in all three directions. The microstructure was revealed with optical microscopy as well as Scanning Electron Microscopy (SEM). The results indicate that the fracture toughness in Y-direction has the highest value (3.10 MPam1/2) that is followed by the one in X-direction which is just a bit lower (2.90 MPam1/2). The Z-direction is found to have a similar fracture toughness (2.95 MPam1/2). This is supported by a homogeneous microstructure showing no hint of the layers used during production.
Dynamic changes in complexes of IRE1α, PERK, and ATF6α during endoplasmic reticulum stress
Authors: Sundaram Arunkumar , Appathurai Suhila , Plumb Rachel , Mariappan Malaiyalam
Published: May 2018

The endoplasmic reticulum (ER) localized unfolded protein response (UPR) sensors, IRE1α, PERK, and ATF6α, are activated by the accumulation of misfolded proteins in the ER. It is unclear how the endogenous UPR sensors are regulated by both ER stress and the ER luminal chaperone BiP, which is a negative regulator of UPR sensors. Here we simultaneously examined the changes in the endogenous complexes of UPR sensors by blue native PAGE immunoblotting in unstressed and stressed cells. We found that all three UPR sensors exist as preformed complexes even in unstressed cells. While PERK complexes shift to large complexes, ATF6α complexes are reduced to smaller complexes on ER stress. In contrast, IRE1α complexes were not significantly increased in size on ER stress, unless IRE1α is overexpressed. Surprisingly, depletion of BiP had little impact on the endogenous complexes of UPR sensors. In addition, overexpression of BiP did not significantly affect UPR complexes, but suppressed ER stress mediated activation of IRE1α, ATF6α and, to a lesser extent, PERK. Furthermore, we captured the interaction between IRE1α and misfolded secretory proteins in cells, which suggests that the binding of unfolded proteins to preformed complexes of UPR sensors may be crucial for activation.
Coarse-grained simulations of actomyosin rings point to a nodeless model involving both unipolar and bipolar myosins
Authors: Nguyen Lam T. , Swulius Matthew T. , Aich Samya , Mishra Mithilesh , Jensen Grant J.
Published: May 2018

Cytokinesis in many eukaryotic cells is orchestrated by a contractile actomyosin ring. While many of the proteins involved are known, the mechanism of constriction remains unclear. Informed by the existing literature and new three-dimensional (3D) molecular details from electron cryotomography, here we develop 3D coarse-grained models of actin filaments, unipolar and bipolar myosins, actin cross-linkers, and membranes and simulate their interactions. Assuming that local force on the membrane results in inward growth of the cell wall, we explored a matrix of possible actomyosin configurations and found that node-based architectures like those presently described for ring assembly result in membrane puckers not seen in electron microscope images of real cells. Instead, the model that best matches data from fluorescence microscopy, electron cryotomography, and biochemical experiments is one in which actin filaments transmit force to the membrane through evenly distributed, membrane-attached, unipolar myosins, with bipolar myosins in the ring driving contraction. While at this point this model is only favored (not proven), the work highlights the power of coarse-grained biophysical simulations to compare complex mechanistic hypotheses.
ARL2BP, a protein linked to retinitis pigmentosa, is needed for normal photoreceptor cilia doublets and outer segment structure
Authors: Moye Abigail R. , Singh Ratnesh , Kimler Victoria A. , Dilan Tanya L. , Munezero Daniella , Saravanan Thamaraiselvi , Goldberg Andrew F. X. , Ramamurthy Visvanathan
Published: May 2018

The outer segment (OS) of photoreceptor cells is an elaboration of a primary cilium with organized stacks of membranous disks that contain the proteins needed for phototransduction and vision. Though ciliary formation and function has been well characterized, little is known about the role of cilia in the development of photoreceptor OS. Nevertheless, progress has been made by studying mutations in ciliary proteins, which often result in malformed OSs and lead to blinding diseases. To investigate how ciliary proteins contribute to OS formation, we generated a knockout (KO) mouse model for ARL2BP, a ciliary protein linked to retinitis pigmentosa. The KO mice display an early and progressive reduction in visual response. Before photoreceptor degeneration, we observed disorganization of the photoreceptor OS, with vertically aligned disks and shortened axonemes. Interestingly, ciliary doublet microtubule (MT) structure was also impaired, displaying open B-tubule doublets, paired with loss of singlet MTs. On the basis of results from this study, we conclude that ARL2BP is necessary for photoreceptor ciliary doublet formation and axoneme elongation, which is required for OS morphogenesis and vision.
Phosphatidylserine and GTPase activation control Cdc42 nanoclustering to counter dissipative diffusion
Authors: Sartorel Elodie , Ünlü Caner , Jose Mini , Massoni-Laporte Aurélie , Meca Julien , Sibarita Jean-Baptiste , McCusker Derek
Published: May 2018

The anisotropic organization of plasma membrane constituents is indicative of mechanisms that drive the membrane away from equilibrium. However, defining these mechanisms is challenging due to the short spatiotemporal scales at which diffusion operates. Here, we use high-density single protein tracking combined with photoactivation localization microscopy (sptPALM) to monitor Cdc42 in budding yeast, a system in which Cdc42 exhibits anisotropic organization. Cdc42 exhibited reduced mobility at the cell pole, where it was organized in nanoclusters. The Cdc42 nanoclusters were larger at the cell pole than those observed elsewhere in the cell. These features were exacerbated in cells expressing Cdc42-GTP, and were dependent on the scaffold Bem1, which contributed to the range of mobility and nanocluster size exhibited by Cdc42. The lipid environment, in particular phosphatidylserine levels, also played a role in regulating Cdc42 nanoclustering. These studies reveal how the mobility of a Rho GTPase is controlled to counter the depletive effects of diffusion, thus stabilizing Cdc42 on the plasma membrane and sustaining cell polarity.
Robustness and evolvability of heterogeneous cell populations
Authors: Kucharavy Andrei , Rubinstein Boris , Zhu Jin , Li Rong
Published: May 2018

Biological systems are endowed with two fundamental but seemingly contradictory properties: robustness, the ability to withstand environmental fluctuations and genetic variability; and evolvability, the ability to acquire selectable and heritable phenotypic changes. Cell populations with heterogeneous genetic makeup, such as those of infectious microbial organisms or cancer, rely on their inherent robustness to maintain viability and fitness, but when encountering environmental insults, such as drug treatment, these populations are also poised for rapid adaptation through evolutionary selection. In this study, we develop a general mathematical model that allows us to explain and quantify this fundamental relationship between robustness and evolvability of heterogeneous cell populations. Our model predicts that robustness is, in fact, essential for evolvability, especially for more adverse environments, a trend we observe in aneuploid budding yeast and breast cancer cells. Robustness also compensates for the negative impact of the systems’ complexity on their evolvability. Our model also provides a mathematical means to estimate the number of independent processes underlying a system’s performance and identify the most generally adapted subpopulation, which may resemble the multi-drug-resistant “persister” cells observed in cancer.
The tomosyn homologue, Sro7, is a direct effector of the Rab GTPase, Sec4, in post-Golgi vesicle tethering
Authors: Rossi Guendalina , Watson Kelly , Kennedy Wade , Brennwald Patrick
Published: May 2018

The tomosyn/Sro7 family is thought to play an important role in cell surface trafficking both as an effector of Rab family GTPases and as a regulator of plasma-membrane SNARE function. Recent work has determined the binding site of GTP-bound Sec4 on Sro7. Here we examine the effect of mutations in Sro7 that block Sec4 binding in determining the role of this interaction in Sro7 function. Using an in vitro vesicle:vesicle tethering assay, we find that most of Sro7’s ability to tether vesicles is blocked by mutations that disrupt binding to Sec4-GTP. Similarly, genetic analysis demonstrates that the interaction with Sec4 is important for most of Sro7’s functions in vivo. The interaction of Sro7 with Sec4 appears to be particularly important when exocyst function is compromised. This provides strong evidence that Sro7 and the exocyst act as dual effector pathways downstream of Sec4. We also demonstrate that Sro7 tethering requires the presence of Sec4 on both opposing membranes and that homo-oligomerization of Sro7 occurs during vesicle tethering. This suggests a simple model for Sro7 function as a Rab effector in tethering post-Golgi vesicles to the plasma membrane in a pathway parallel to that of the exocyst complex.
Foundations of Power Transition Theory
Authors: Tammen Ronald L. , Kugler Jacek , Lemke Douglas
Published: May 2018

Power Transition theory is a dynamic and structural model for analyzing fundamental shifts in global power. The theory itself, while maintaining its core concepts, has metamorphosed over time by adding new dimensions and addressing new topics. It is both data based and qualitatively intuitive.

As a probabilistic theory, it has proven useful in predicting the conditions that forecast both conflict and cooperation at the global, national, and subnational levels of analysis. As a foreign policy tool, it creates historical signposts pointing toward tectonic shifts in nation state and alliance power profiles.
Insect Navigation: Neural Basis to Behavior
Authors: Heinze Stanley
Published: May 2018

Navigation is the ability of animals to move through their environment in a planned manner. Different from directed but reflex-driven movements, it involves the comparison of the animal’s current heading with its intended heading (i.e., the goal direction). When the two angles don’t match, a compensatory steering movement must be initiated. This basic scenario can be described as an elementary navigational decision. Many elementary decisions chained together in specific ways form a coherent navigational strategy. With respect to navigational goals, there are four main forms of navigation: explorative navigation (exploring the environment for food, mates, shelter, etc.); homing (returning to a nest); straight-line orientation (getting away from a central place in a straight line); and long-distance migration (seasonal long-range movements to a location such as an overwintering place). The homing behavior of ants and bees has been examined in the most detail. These insects use several strategies to return to their nest after foraging, including path integration, route following, and, potentially, even exploit internal maps. Independent of the strategy used, insects can use global sensory information (e.g., skylight cues), local cues (e.g., visual panorama), and idiothetic (i.e., internal, self-generated) cues to obtain information about their current and intended headings.

How are these processes controlled by the insect brain? While many unanswered questions remain, much progress has been made in recent years in understanding the neural basis of insect navigation. Neural pathways encoding polarized light information (a global navigational cue) target a brain region called the central complex, which is also involved in movement control and steering. Being thus placed at the interface of sensory information processing and motor control, this region has received much attention recently and emerged as the navigational “heart” of the insect brain. It houses an ordered array of head-direction cells that use a wide range of sensory information to encode the current heading of the animal. At the same time, it receives information about the movement speed of the animal and thus is suited to compute the home vector for path integration. With the help of neurons following highly stereotypical projection patterns, the central complex theoretically can perform the comparison of current and intended heading that underlies most navigation processes. Examining the detailed neural circuits responsible for head-direction coding, intended heading representation, and steering initiation in this brain area will likely lead to a solid understanding of the neural basis of insect navigation in the years to come.
Tamerlane and the Timurids
Authors: Forbes Manz Beatrice
Published: May 2018

The Timurid dynasty was founded in 1370 by the Turkic warlord Temür, usually known in the west as Tamerlane (Temür the lame). Rising to power within the realm of Chinggis Khan’s second son Chaghadai, Temür established his capital at Samarqand and embarked on a career of conquest throughout the former Mongolian Empire and the Central Islamic lands. While his campaigns ranged from Delhi almost to Moscow and from the eastern Turkestan to western Anatolia, Temür established an administration only over the central regions, including Iran and Transoxiana; these were largely settled and Persian-speaking territories. Temür and his followers were Turks loyal to the Mongol tradition, but they were also Muslim and well acquainted with Perso-Islamic culture. The dynasty lasted three more generations—those of Shāhrukh (1409–1447); Abu Sa`īd (1451–1469); and Sulṭān Ḥusayn Bayqara (1469–1506). During this time, the Timurid state shrank in size but gained fame for its wide-ranging cultural patronage and sophisticated styles in architecture, literature, and the arts of the book. In 1507, the Uzbek Shibani Khan overthrew the Timurid dynasty and took over its eastern territories. The Timurid prince Babur Mirza retreated from his region of Ferghana to Kabul and then in 1526 conquered Delhi and founded the Mughal or Later Timurid dynasty.
Cultural Citizenship and Modernity in the Netherlands Indies
Authors: Schulte Nordholt Henk
Published: May 2018

By exclusively focusing on the agency of the Dutch, colonial historiography ignored the pivotal role of indigenous middle classes in sustaining the colonial regime. Conventional nationalist historiography, on the other hand, presumes a linear development from urbanization, the rise of the indigenous middle classes, education, and the spread of modernity toward nationalism and revolution as the logical outcome of this process. This article aims to disconnect modernity from nationalism by focusing on the role of cultural citizens in the late-colonial period in the Netherlands Indies, for whom modernity was in the very first place a desirable lifestyle. The extent to which their desires, capitalist strategies, and the interests of the colonial state coincided is illustrated by a variety of advertisements and school posters, which invited members of the indigenous urban middle classes to become cultural citizens of the colony. The image of the cultural citizen was framed within the confinement of the nuclear family, which had a conservative impact on gender relationships.
Kashmir: From Princely State to Insurgency
Authors: Rai Mridu
Published: May 2018

Paradise lost, on fire, or on a river of hell: purple prose abounds in descriptions of Kashmir today. But in this instance, the hyperbole may be alarmingly close to reality. Since 1989–1990, Kashmir (i.e., the Valley rather than the entire state of Jammu and Kashmir for which the name is often informally used) has been a battleground pitting a popularly backed insurgency—sometimes accompanied by armed militancy—against Indian state dominance undergirded by one of the highest concentrations of armed forces among civilians in the world. The armed forces are about 700,000 strong in the Valley, producing an astonishing average of one soldier for every eleven civilians. A death toll in calamitous numbers (perhaps 70,000 killed and 8,000 “disappeared”, many of whom are presumed dead) countless instances of rape and torture, and the declining health of civil liberties as of individuals in Kashmir have many worried.

Most accounts seeking to explain this state of affairs begin around August 14–15, 1947. On this day were born not only the two nation-states of India and Pakistan but also the rival claims of both to Kashmir. If Kashmir’s troubles were only about the Indo-Pakistani territorial contestation, 1947 would be where to start. However, the “Kashmir Problem” encompasses other contentious aspects that have drawn less attention and whose roots are buried deeper in time. These include a crisis of legitimate governance and the interweaving of religion and politics—all playing out in the midst of contested relations between different loci of central and local power. A narrow focus on the year 1947 alone, moreover, holds Kashmir’s history hostage to Indian and Pakistani official narratives. This is evident in the work of countless political scientists and policy experts. New scholarship has pushed historical examination to go further back by at least a century, if not more, to capture vital transformations in the understandings of sovereignty, territoriality, and the legitimacy to rule that shaped Kashmiris well before 1947. These changes cast long shadows that reach into the present.
Asia in the Gunpowder Revolution
Authors: Levi Scott C.
Published: May 2018

Contrary to long-held notions that gunpowder weapons technologies were devised in the West and gradually transmitted eastward into Asia, more recent scholarship indicates that innovations flowed in both directions. Scholars have also come to recognize that there was no uniformity in the ways that states implemented gunpowder weapons, and that multiple factors relating to environment, demographics, and cultural preferences informed decisions about when and how to embrace the new technology. The major Asian agrarian states of the Ottomans, Safavids, and Mughals (the so-called Gunpowder Empires) and the Ming and Qing dynasties in China implemented gunpowder weapons differently. The Ottomans were the most aggressive in this regard, the Mughals preferred a hybrid force, and the Safavids long favored cavalry. Chinese militaries employed hybrid forces to great effect, but in later years a lengthy peace during the Qing era slowed the implementation of new technologies. In Central Asia and other places where rulers could rely on large numbers of well-trained, fast-moving mounted archers and a nearly endless supply of horses, they found little reason to rush to embrace what for several centuries represented an expensive, slow, and unreliable technology.
Inter-State Water Disputes in South India
Authors: Fernandes Leela
Published: May 2018

Water-related disputes in India have been a fraught area of contestation between state governments in the post-colonial period. Since the late 20th century, much of this conflict has been centered on mechanisms of legal adjudication both through the centralized state machinery of tribunals set up by the central government and by legal suits brought by states before the Supreme Court. Formal records of tribunal and court judgments provide skeletal accounts of legal claims, technical evidence, and judiciary responses between unitary state governments with hardened positions and conflicting interests. Tamil Nadu, a lower riparian state is reliant on water-sharing arrangements and the shared management of water-related infrastructure with its three neighboring states of Andhra Pradesh, Karnataka, and Kerala. The water-related agreements that link Tamil Nadu with its neighbors vary in significant ways in terms of the scope of the agreements, the kinds of issues under contention, the political dynamics of the agreement, and the outcome and implementation of each of the agreements. Political, institutional, and agential dimensions of state action are both shaped and constrained by historical structures of political economy. Both centralized structures of the colonial state and the political economy of India’s planned developmental state shape this set of interstate water negotiations and disputes that weigh on the states that share water resources and infrastructure in Southern India. While historical processes have produced the structural conditions that have shaped such disputes, recent policies of liberalization have intensified conflicts over water. For instance, processes of urbanization and city-centric models of growth have increased pressures on water resources in India. Social scientific scholarship that has focused on the politics of economic reforms and on the ways in which reforms have been shaped by India’s federal structure has tended to treat states as discrete entities. Such scholarship has analyzed the impact of India’s federal structure on reforms through a focus on relationships between states and the central government. While this has produced a heightened focus on the significance of federalism in the post-liberalization period, such work has paid less attention to relationships between states. The focus of such social scientific scholarship on particular sectors of the economy (such as telecom, electricity, and land/real estate) that are visibly associated with reform policies has compounded this analytical gap. Unlike such sectors, water is not contained within the territorial boundaries of states. A historical perspective on water disputes provides a means for unsettling the conventional analytical boundaries of political scientific conceptions of federalism in the post-liberalization period.
Interactions between North Africa and Spain: Medieval and Early Modern
Authors: Gómez-Rivas Camilo
Published: May 2018

Arabic-speaking Muslim polities existed in medieval Spain and Portugal where they were superseded by Christian empires that gradually disavowed cultural connections to this past. Hebrew and Arabic were largely expurgated from homes and libraries. Jews and Muslims who refused to convert were expelled. And while an incipient study of that past existed, echoed even in popular literary forms, the need to disavow kinship prevailed, at least publicly and officially. The Maghrib, for its part, separated by a mere fourteen kilometers of sea from the southern tip of Spain, experienced Portuguese and Spanish imperial expansion firsthand, receiving the bulk of the displaced and interacting with fortified settlements and encroachments along the Atlantic and Mediterranean coasts. Later European colonization of North Africa completed the galvanization of a Maghribi culture of resistance to and disavowal of European, Latin, and Christian cultural forms and connections. Spain and North Africa came to be conceived as separate worlds; domains of inimical faiths; divided by culture, language, religion, and a history of mutual hostility. This sense of separateness is deceptive, however, as the Iberian Peninsula and North Africa are bound by deep and extensive commercial, material, and cultural contacts. They share inextricable histories in which alternating movements of commerce, conflict, and migration have played fundamental roles in shaping recognizably Western Mediterranean societies. They should be thought of as areas of a unified region with a common culture, or at the very least, as areas sharing a common region, in which they interact regularly, creating extensive ties and parallel forms of cultural and social organization.
Vesta and Ceres
Authors: Righter Kevin
Published: May 2018

Asteroids 1 Ceres and 4 Vesta are the two most massive asteroids in the asteroid belt, with mean diameters of 946 km and 525 km, respectively. Ceres was reclassified as a dwarf planet by the International Astronomical Union as a result of its new dwarf planet definition which is a body that (a) orbits the sun, (b) has enough mass to assume a nearly round shape, (c) has not cleared the neighborhood around its orbit, and (d) is not a moon. Scientists’ understanding of these two bodies has been revolutionized in the past decade by the success of the Dawn mission that visited both bodies. Vesta is an example of a small body that has been heated substantially and differentiated into a metallic core, silicate mantle, and basaltic crust. Ceres is a volatile-rich rocky body that experienced less heating than Vesta and has differentiated into rock and ice. These two contrasting bodies have been instrumental in learning how inner solar system material formed and evolved.
Astrology in Ancient Greek and Roman Culture
Authors: Campion Nicholas
Published: May 2018

Astrology was a central feature of Greek and Roman culture. A knowledge of astrology’s claims, practices, and world view is essential for a full understanding of religion, politics, and science in the Greek and Roman worlds. Astrology is the name given to a series of diverse practices based in the idea that the stars, planets, and other celestial phenomena possess significance and meaning for events on Earth. It assumes a link between Earth and sky in which all existence, spiritual, psychological, and physical, is interconnected. Most premodern cultures practice a form of astrology. A particularly complex variety of it evolved in Mesopotamia in the first and second millennia bce from where it was imported into the Hellenistic world from the early 4th century bce onward. There it became attached to three philosophical schools, those pioneered by Plato, Aristotle and the Stoics, all of which shared the assumption that the cosmos is a single, living, integrated whole. Hellenistic astrology also drew on Egyptian temple culture, especially the belief that the soul could ascend to the stars. By the 1st century ce, the belief in the close link between humanity and the stars had become democratized and diversified into a series of practices and schools of thought which ranged across Greek and Roman culture. It was practiced at the imperial court and in the street. It could be used to predict individual destiny, avert undesirable events, and arrange auspicious moments to launch new enterprises. It could advise on financial fortunes or the condition of one’s soul. It was conceived of as natural science and justified by physical influences or considered to be divination, concerned with communication with the gods and goddesses. In some versions, the planets were neither influences nor causes of events on Earth, but timing devices, which indicated the ebb and flow of human affairs, like the hands on a modern clock. Astrology had a radical view of time in which the future already existed, at least in potential, and the astrologer’s task was to intercede in time, altering the future to human advantage. In this sense astrology was a form of “participation mystique” in which time and space were conceived of as a single entity and individual and social benefits were to be derived from engaging with it. There was no one single version of astrology and there were disputes about what it was and what it could do, for example, whether it could make precise predictions about individual affairs or merely general statements. From the early 4th century it went into a progressive decline, facing challenges from Christianity and the fragmentation of classical culture, especially in Western Europe. It survived in Persia, exerted a powerful influence on Indian astrology, and was transmitted to the Islamic world, from where it was reimported into the Latin West in the 12th century.
The Great Depression
Authors: Gellman Erik , Rung Margaret
Published: May 2018

From the late 1920s through the 1930s, countries on every inhabited continent suffered through a dramatic and wrenching economic contraction termed the Great Depression, an economic collapse that has come to represent the nadir of modern economic history. With national unemployment reaching well into double digits for over a decade, productivity levels falling by half, prices severely depressed, and millions of Americans without adequate food, shelter or clothing, the United States experienced some of the Great Depression’s severest consequences. The crisis left deep physical, psychological, political, social, and cultural impressions on the national landscape. It encouraged political reform and reaction, renewed labor activism, spurred migration, unleashed grass-roots movements, inspired cultural experimentation, and challenged family structures and gender roles.
The Oil Industry
Authors: Castañeda Christopher J.
Published: May 2018

The modern oil industry began in 1859 with Edwin Drake’s discovery of oil at Titusville, Pennsylvania. Since then, this dynamic industry has experienced dramatic episodes of growth, aggressive competition for market share, various forms of corporate organization and cartel-like agreements, and governmental efforts at regulation and control, as well as monopoly, mergers, and consolidation. The history of the oil industry reflects its capital-intensive nature. Immense sums of money are spent on oil discovery, production, and refining projects. Marketing, transportation, and distribution systems likewise require enormous amounts of financing and logistical planning. Although oil is often produced in conjunction with, or in wells pressurized by, natural gas, the oil industry is distinct from the related natural gas industry. Since its origins in the mid-19th century, the oil industry has developed an industrial structure that emphasizes scale and scope to maximize profits. Profits can be huge, which attracts entrepreneurial efforts on individual, corporate, and national scales. By the late 20th through early 21st century, the oil industry had begun confronting questions about long-term viability, combined with an increasingly influential environmental movement that seeks to reduce fossil fuel consumption and prevent its toxic waste and by-products from polluting human, animal habitats, and natural habitats.
Antebellum U.S. Labor Markets
Authors: Rosenbloom Joshua L.
Published: May 2018

The United States economy underwent major transformations between American independence and the Civil War through rapid population growth, the development of manufacturing, the onset of modern economic growth, increasing urbanization, the rapid spread of settlement into the trans-Appalachian west, and the rise of European immigration. These decades were also characterized by an increasing sectional conflict between free and slave states that culminated in 1861 in Southern secession from the Union and a bloody and destructive Civil War. Labor markets were central to each of these developments, directing the reallocation of labor between sectors and regions, channeling a growing population into productive employment, and shaping the growing North–South division within the country. Put differently, labor markets influenced the pace and character of economic development in the antebellum United States. On the one hand, the responsiveness of labor markets to economic shocks helped promote economic growth; on the other, imperfections in labor market responses to these shocks significantly affected the character and development of the national economy.
The City Beautiful Movement, 1890–1920
Authors: Fairfield John D.
Published: May 2018

The City Beautiful movement arose in the 1890s in response to the accumulating dirt and disorder in industrial cities, which threatened economic efficiency and social peace. City Beautiful advocates believed that better sanitation, improved circulation of traffic, monumental civic centers, parks, parkways, public spaces, civic art, and the reduction of outdoor advertising would make cities throughout the United States more profitable and harmonious. Engaging architects and planners, businessmen and professionals, and social reformers and journalists, the City Beautiful movement expressed a boosterish desire for landscape beauty and civic grandeur, but also raised aspirations for a more humane and functional city. “Mean streets make mean people,” wrote the movement’s publicist and leading theorist, Charles Mulford Robinson, encapsulating the belief in positive environmentalism that drove the movement. Combining the parks and boulevards of landscape architect Frederick Law Olmsted with the neoclassical architecture of Daniel H. Burnham’s White City at the Chicago’s World Columbian Exposition in 1893, the City Beautiful movement also encouraged a view of the metropolis as a delicate organism that could be improved by bold, comprehensive planning. Two organizations, the American Park and Outdoor Art Association (founded in 1897) and the American League for Civic Improvements (founded in 1900), provided the movement with a national presence. But the movement also depended on the work of civic-minded women and men in nearly 2,500 municipal improvement associations scattered across the nation. Reaching its zenith in Burnham’s remaking of Washington, D.C., and his coauthored Plan of Chicago (1909), the movement slowly declined in favor of the “City Efficient” and a more technocratic city-planning profession. Aside from a legacy of still-treasured urban spaces and structures, the City Beautiful movement contributed to a range of urban reforms, from civic education and municipal housekeeping to city planning and regionalism.
The Development of the “Apostolic Tradition” in Early Christian Worship
Authors: Johnson Maxwell E.
Published: May 2018

Contrary to the assumptions often held by previous scholars, contemporary liturgical scholarship is coming increasingly to realize and emphasize that Christian worship was diverse even in its biblical and apostolic origins, multi- rather than monolinear in its development, and closely related to the several cultural, linguistic, geographical, and theological expressions and orientations of distinct churches throughout the early centuries of Christianity. Apart from some rather broad (but significant) commonalities discerned throughout various churches in antiquity, the traditions of worship during the first three centuries of the common era were rather diverse in content and interpretation, depending upon where individual practices are to be located. Indeed, already in this era, together with the diversity of Christologies, ecclesiologies, and, undoubtedly, liturgical practices encountered in the New Testament itself, the early history of the “tradition” of Christian worship is, simultaneously, the early history of the developing liturgical traditions of several differing Christian communities and language groups: Armenian, Syrian, Greek, Coptic, and Latin, We should not, then, expect to find only one so-called “apostolic” liturgical tradition, practice or theology surviving in this period before the Council of Nicea (325 ce) but, rather, great diversity both within the rites themselves as well as in their theological interpretations. This essay highlights the principal occasions for Christian worship in the first three centuries for which the textual and liturgical evidence is most abundant: Christian initiation, the eucharistic liturgy with its central anaphoral prayer, daily prayer (the liturgy of the hours), and the feasts and seasons of the liturgical year.
Mexico’s First Decades of Independence
Authors: Archer Christon I. , Neufeld Stephen B.
Published: May 2018

By 1821, a decade of bloody warfare had fragmented the viceroyalty of New Spain, divided the population into hostile factions of patriots and royalists, and intensified old hatreds among peninsular, or European-born, Spaniards (gachupines), American-born criollos, the complex racially mixed groups, and the indigenous population. In many regions, the native villagers were angry, resentful, and politically mobilized. The war had taught different segments of the population that mobilization and the effective use of political action—even violence—could address their political demands, their interminable grievances concerning landholding, and their chronic disputes over taxation.

These campesino insurgent and guerrilla fighters, many of whom knew little Spanish, fought tenaciously and often successfully for different factions and regions. Although some sought to escape combat and brutal suppression by fleeing into rugged mountains or posing as neutral noncombatants, guerrilla warfare, endemic banditry, and pervasive violence changed the lives of ordinary people.

In the cities, large floating populations of vagabonds, gamblers, and petty criminals frequented cockfights, bullfights, and other popular entertainments; loitering in parks and public markets, they made the night extremely dangerous for respectable urban residents. Nevertheless, even as indigenous and mestizo people suffered from the dislocations of war, arbitrary conscription, heavy taxation, and narrow paternalism, some also developed feelings of pride and empowerment that would find new expression in the post-independence decades.

By the outbreak of the war with the United States twenty-five years later, Mexico was ill-equipped and unprepared to defend its territory. Its economy was in ruins, its army lacked modern weapons and training, and many of its citizens were unwilling to engage in the defense of a nation that they did not fully comprehend. Others rose to lead the republic in its heroic, but impossible, defense.