Perceived Vertical and Lateropulsion: Clinical Syndromes, Localization, and Prognosis

We present a clinical classification of central vestibular syndromes according to the three major planes of action of the vestibulo-ocular reflex: yaw, roll, and pitch. The plane-specific syndromes are determined by ocular motor, postural, and percep tual signs. Yaw plane signs are horizontal nystagmus, past pointing, rotational and lat eral body falls, deviation of perceived straight-ahead to the left or right. Roll plane signs are torsional nystagmus, skew deviation, ocular torsion, tilts of head, body, and perceived vertical in a clockwise or counterclockwise direction. Pitch plane signs are upbeat/downbeat nystagmus, forward/backward tilts and falls, deviations of the per ceived horizon. The thus defined vestibular syndromes allow a precise topographic analysis of brainstem lesions according to their level and side. Special emphasis is placed on the vestibular roll plane syndromes of ocular tilt reaction, lateropulsion in Wallenberg's syndrome, thalamic and cortical astasia and their association with roll plane tilt of perceived vertical. Recovery is based on a functionally significant central compensation of a vestibular tone imbalance, the mechanism of which is largely un known. Physical therapy may facilitate this central compensation, but this has not yet been proven in prospective studies

Downbeat nystagmus: aetiology and comorbidity in 117 patients

Objectives: Downbeat nystagmus (DBN) is the most common form of acquired involuntary ocular oscillation overriding fixation. According to previous studies, the cause of DBN is unsolved in up to 44% of cases. We reviewed 117 patients to establish whether analysis of a large collective and improved diagnostic means would reduce the number of cases with ``idiopathic DBN'' and thus change the aetiological spectrum.Methods: The medical records of all patients diagnosed with DBN in our Neurological Dizziness Unit between 1992 and 2006 were reviewed. In the final analysis, only those with documented cranial MRI were included. Their workup comprised a detailed history, standardised neurological, neuro-otological and neuro-ophthalmological examination, and further laboratory tests.Results: In 62% (n = 72) of patients the aetiology was identified (``secondary DBN''), the most frequent causes being cerebellar degeneration (n = 23) and cerebellar ischaemia (n = 10). In 38% (n = 45), no cause was found (``idiopathic DBN''). A major finding was the high comorbidity of both idiopathic and secondary DBN with bilateral vestibulopathy (36%) and the association with polyneuropathy and cerebellar ataxia even without cerebellar pathology on MRI.Conclusions: Idiopathic DBN remains common despite improved diagnostic techniques. Our findings allow the classification of ``idiopathic DBN'' into three subgroups: ``pure'' DBN (n = 17); ``cerebellar'' DBN (ie, DBN plus further cerebellar signs in the absence of cerebellar pathology on MRI; n = 6); and a ``syndromatic'' form of DBN associated with at least two of the following: bilateral vestibulopathy, cerebellar signs and peripheral neuropathy (n = 16). The latter may be caused by multisystem neurodegeneration

From Divergence to Convergence: Re-evaluating the History Behind China's Economic Boom

China's long-term economic dynamics pose a formidable challenge to economic historians. The Qing Empire (1644-1911), the world's largest national economy prior to the 19th century, experienced a tripling of population during the 17th and 18th centuries with no signs of diminishing per capita income. In some regions, the standard of living may have matched levels recorded in advanced regions of Western Europe. However, with the Industrial Revolution a vast gap emerged between newly rich industrial nations and China's lagging economy. Only with an unprecedented growth spurt beginning in the late 1970s has the gap separating China from the global leaders been substantially diminished, and China regained its former standing among the world's largest economies. This essay develops an integrated framework for understanding this entire history, including both the long period of divergence and the more recent convergent trend. The analysis sets out to explain how deeply embedded political and economic institutions that had contributed to a long process of extensive growth subsequently prevented China from capturing the benefits associated with new technologies and information arising from the Industrial Revolution. During the 20th century, the gradual erosion of these historic constraints and of new obstacles created by socialist planning eventually opened the door to China's current boom. Our analysis links China's recent economic development to important elements of its past, while using the success of the last three decades to provide fresh perspectives on the critical obstacles undermining earlier modernization efforts, and their removal over the last century and a half.

HSV-1 not only in human vestibular ganglia but also in the vestibular labyrinth

Reactivation of herpes simplex virus type 1 (HSV-1) in the vestibular ganglion (VG) is the suspected cause of vestibular neuritis (VN). Recent studies reported the presence of HSV-1 DNA not only in human VGs but also in vestibular nuclei, a finding that indicates the possibility of viral migration to the human vestibular labyrinth. Distribution of HSV-1 DNA was determined in geniculate ganglia, VGs, semicircular canals, and macula organs of 21 randomly obtained human temporal bones by nested PCR. Viral DNA was detected in 48% of the labyrinths, 62% of the VGs, and 57% of the geniculate ganglia. The potential significance of this finding is twofold: (1) Inflammation in VN could also involve the labyrinth and thereby cause acute unilateral vestibular deafferentation. (2) As benign paroxysmal positional vertigo often occurs in patients who have had VN, it could also be a sequel of viral labyrinthitis. Copyright (C) 2001 S. Karger AG, Basel

Reproductive and Social Dynamics of a Lek Breeding Bird

Sociality and the unequal apportionment of reproductive success among social individuals is a common characteristic of many vertebrate taxa. To date, our understanding of what factors drive high variance in reproductive success (i.e., intra vs. inter-sexual selection) and which male attributes contribute to that variance, are still fragmentary for most species. Moreover, how social structure interacts with individual behavior and fitness remains understudied despite its potential importance to the evolution of cooperation. This dissertation research focused on understanding this complex synergistic interplay between social and reproductive dynamics in a lek-breeding bird, the wire-tailed manakin. The first chapter examines the complex display ritual of this species of manakin (Pipra filicauda). More specifically, it quantifies and compares the frequency of individual behavior among males of different age and social status. In addition, the first chapter examines in detail the genetic relatedness of male partnerships to test the kin selection hypothesis. The second chapter uses these complex reticulate interactions to build social networks. This chapter details the emergent properties of these networks and examines their role in determining male social ascendancy and access to reproduction. The third chapter uses a combination of molecular tools and network analysis to create a synthetic understanding of variance in male reproductive success. This chapter presents molecular estimates of reproductive skew and examines the social correlates of male reproductive success. Our primary results show 1) that males within leks are not more related than expected by chance, enabling us to reject the role of kin selection in the lek evolution of wire-tailed manakins; 2) that the complex networks of social interactions among males contain the ingredients needed for the evolution of cooperation; 3) that social connectivity of young males was predictive of their later social ascendancy; 4) that the number of male affiliations was strongly predictive of the number of offspring he sired. Overall our findings greatly advance our understanding of social relationships and the role they play in the evolution of cooperation and reproductive variance

Explicitly linking field- and satellite- derived measurements for improved vegetation quantification and disturbance detection

Arid and semi-arid ecosystems have been recognized as critical in supporting over one-third of the world's populations, notably those more dependent on the natural resource base for their livelihoods. These systems, and especially savannas within them, are highly vulnerable to predicted fluctuations in climatic change, disturbances, and management regimes. This research posits these areas in a social-ecological system (SES) framework that encompasses human, governance, and recourse units. A challenge in both SES and CHANS (coupled human and natural systems) research is how to explicitly and empirically link the social and the ecological, and further how to extrapolate from sets of case studies to the greater region, supra-system, or SES / CHANS theory and practice. This work leverages Landsat and IKONOS imagery as well as field-based vegetation sampling (structure and species) through the use of IDL (interactive data language) visualizations, both pixel- and object-based classifications, and CART (classification and regression tree) analysis. The longer term goal of this work is to produce a protocol and classification scheme modified from the 1976 Anderson scheme to include both structure and disturbance explicitly in processing, mapping, monitoring, and management. In creating SVCs (Structural Vegetation Categories) built from field data there is strong potential for extracting 3-D data from 2-D imagery once the protocol produces robust results with high enough accuracies. As hypothesized, the object-based classifications produced higher overall accuracy (70.83%), though the pixel-based classification performed better in the detection of woodlands (90.91%). Given the spatial scales of the imagery as compared to the size of the field plots and transect spacing, it is important to remember that when extrapolating to other areas a critical part of spatial scale is extent (not just grain). That is, the inherent clumping of trees versus shrubs may be driving the better performance of pixel-based for woodlands but not so for shrublands. Sensitivity to placement of plots and especially plot sizes across future sites will help explore this question and move SES research into a realm whereby remote sensing and vegetation sampling can provide improved empirical linkages among the subsystems and their feedbacks.Geography and the Environmen

Hindrances of the Hinterland: Ranching in Robert Wilcox’s Mato Grosso

Book Review Robert W. Wilcox, Cattle in the Backlands: Mato Grosso and the Evolution of Ranching in the Brazilian Tropics. Austin, TX: University of Texas Press, 2017.Book Review Robert W. Wilcox, Cattle in the Backlands: Mato Grosso and the Evolution of Ranching in the Brazilian Tropics. Austin, TX: University of Texas Press, 2017.Book Review Robert W. Wilcox, Cattle in the Backlands: Mato Grosso and the Evolution of Ranching in the Brazilian Tropics. Austin, TX: University of Texas Press, 2017

Bedside differentiation of vestibular neuritis from central "vestibular pseudoneuritis".

Acute unilateral peripheral and central vestibular lesions can cause similar signs and symptoms, but they require different diagnostics and management. We therefore correlated clinical signs to differentiate vestibular neuritis (40 patients) from central ‘‘vestibular pseudoneuritis’’ (43 patients) in the acute situation with the final diagnosis assessed by neuroimaging. Skew deviation was the only specific but non-sensitive (40%) sign for pseudoneuritis. None of the other isolated signs (head thrust test, saccadic pursuit, gaze evoked nystagmus, subjective visual vertical) were reliable; however, multivariate logistic regression increased their sensitivity and specificity to 92%

Die Schleiereule: flexibel durch das Leben : Gedanken über einen Kulturfolger

Schleiereulen leben in Deutschland als Gebäudebrüter eng angeschlossen an den Menschen. Der Beitrag spiegelt Gedanken wider, ob und wie Schleiereulen in Mitteleuropa bereits vor der Besiedlung durch den Menschen geeignete Lebensräume vorfanden und eine Population etablieren konnten. Das flexible Verhalten der Schleiereule, insbesondere das variable Paarungssystem, wird auf der Basis verhaltensökologischer Überlegungen vorgestellt und erläutert.Due to their dependence on breeding places in buildings Barn owl Tyto alba occurrence in Germany is closely connected to human settlements. The present contribution approaches the question if Tyto alba was able to spread over Central Europe already before colonization by humans. Further its flexibility in behaviour is described and discussed, especially concerning the reproduction strategy