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For many researchers, government agencies, and emergency responders, access to the geospatial data of US electric power infrastructure is invaluable for analysis, planning, and disaster recovery. H...

The paper examines the optimal advertising policy for a profit-maximizing firm in a single market area. The results are first derived for a spaceless market, indicating the steady-state equilibrium advertising policy and market size. The model is then extended to account for the costs of overcoming distance. It is shown that there is an outward limit to marketing, and that this distance is dependent on the market price and retirement rate of the good and the interest rate. The minimal price necessary for covering any given distance is derived, along with the minimal advertising effort necessary to reach the steady-state market size. It is shown that the steady-state market size, advertising policy, and switching time are all monotonic functions of distance.

The problem of locating facilities to maximize their accessibility on networks where costs are functions of flow volume is considered. In particular, an accessibility model developed by Leonardi is extended to bipartite and tree networks whose arc costs are determined by a flow-dependent congestion function. The resultant nonseparable equilibrium problem is solved heuristically, and numerical simulations are used to explore the model's behavior under varying conditions.

Dynamic traffic assignment (DTA) is at the heart of much ITS research. Assigning traffic, whether for planning purposes or for real time route guidance, is a difficult problem. Recent advances in user-optimal dynamic traffic assignment have built on the methods developed for static user-optimal assignments. Since assignment models are complex, they will not use many of the network analysis functions found in commercial GIS packages. Custom software will have to be developed. In this paper we explore the problems faced in solving static and dynamic assignments and relate those problems to information that is likely to be based in a traffic control center’s GIS database. Because of the size of the problem and the need for faster-than-real-time analysis, how and when data is transferred between a GIS to analysis modules is important. Further, many approaches for GIS software design and spatial data handling, such as OOP and dynamic segmentation, may impose too much overhead to be of much use in time-sensitive ITS applications.

The development of Rich Internet Application tools and web mapping services, coupled with the dissemination of detailed, up-to-date socioeconomic data, present an opportunity to develop intuitive geospatial visual analytic tools. This paper presents our efforts at developing such tools that combine Google Maps, Flex, and data from the American Community Survey.

Evaluating various alternatives for transportation policy and investments naturally leads one to consider a series of 'What if questions. Merging the technologies of geographic information systems with the analytic power of transportation models can yield a spatial decision support system capable of assessing the impacts of a wide array of planning options. We report here on the development and application of such a system, the Bangladesh Transportation Modeling System. Building the BTMS forced us to resolve several of the issues involved in merging GIS technology with transportation models.

Evacuation models, which seek to calculate evacuation time estimates (ETEs) and evaluate evacuation strategies, are based on assumptions concerning human behavior. One of the most consistent assumptions is that once an evacuation order is given, people will proceed to an evacuation point. ETEs are further assumed to be a function of network congestion along arcs. We test these assumptions through a survey of residents of Key West, Florida who experienced evacuation orders associated with Hurricane Wilma in 2005. Of particular interest are the trips residents made between the time the evacuation order was given and the deadline for evacuation, what we call pre-evacuation trips. Such trips were made by people who evacuated as well as by those who waited out the storm. That is, traffic on the transportation network is not solely limited to people seeking to evacuate. Survey data indicate three important aspects of pre-evacuation trip making behavior that run counter to common evacuation modeling assumptions. First, trip delays at stops are longer than delays on links. Second, trip delays are associated with trip purposes, which often are not to evacuate an area, and there is evidence of trip chaining. Finally, patterns of pre-evacuation trips show a dispersal of origins and destinations resulting in pre-evacuation trips that flow in many directions, not just toward evacuation points.

Thematic maps using KML and KMZ are common for point and line features, but scarce for area features. We present a method and website for generation of the thematic map KMLs based on US Census geography. By taking advantage of various preprocessing and indexing methods, thematic maps viewable in any KML compliant viewer (eg, Google Maps, Google Earth, or ArcGIS Explorer) can be generated very quickly. Our implementation covers counties, census tracts, and zip code tabulation areas for the entire United States and its territories and 31 socio-demographic variables.

Transportation geography is the study of the spatial aspects of transportation. It includes the location, structure, environment, and development of networks as well as the analysis and explanation of the interaction or movement of goods and people (Black 1989). In addition it encompasses the role and impacts—both spatial and aspatial—of transport in a broad sense including facilities, institutions, policies and operations in domestic and international contexts. It also provides an explicitly spatial perspective, or point of view, within the interdisciplinary study of transportation. There has been substantial progress in the development of the transportation geography subfield over the last ten years. In 1993, the Journal of Transport Geography was started in the UK, providing the subfield with its own eponymous journal. Several second editions of key textbooks were published, including The Geography of Transportation (Taaffe et al. 1996), The Geography of Urban Transportation (Hanson 1995), and Modern Transport Geography (Hoyle and Knowles 1998). The Transportation Geography Specialty Group (TGSG) instituted the Edward L. Ullman Award for scholarly contributions to the subfield; recipients have included Edward Taaffe, Harold Mayer, Howard Gauthier, William Garrison, William Black, James Vance, Susan Hanson, Morton O’Kelly, Bruce Ralston, Donald Janelle, Thomas Leinbach, Brian Slack, and Kingsley Haynes. The specialty group also began honoring students who have written the best doctoral dissertations and masters theses each year, and a TGSG web page was created. The University of Washington Department of Geography instituted the Douglas K. Fleming lecture series in transportation geography at AAG annual meetings. Finally, transport geographers have played prominent roles in a Geography and Regional Science Program organized joint National Science Foundation/European Science Foundation initiative on Social Change and Sustainable Transport (SCAST) (Leinbach and Smith 1997; Button and Nijkamp 1997). This initiative led to the development of the North American-based Sustainable Transportation Analysis and Research (STAR) network led by geographer William Black as a counterpart to the European-based Sustainable Transport in Europe and Links and Liaisons with America (STELLA) network. Together, these initiatives and research networks offer significant opportunities for geographers to contribute to a growing body of literature on the environmental, economic, and equity implications of transportation systems.

In this paper a recursive version of a dynamic road investment problem is developed by extending the Ellet-Walters developmental model of transportation so as to account explicitly for the effects of road investment on the supply and demand of the port hinterland's product. An explicit lagged supply function that depends upon commodity price and road penetration is related to a given linear demand function, assuming annual market clearance. A recursive formulation of a cobweb-like dynamic market is thus obtained. Secondly, we derive the optimal road-penetration policy of a road-planning authority faced with a given cost function and with this form of market dynamics. The road-building policy is constrained both by long-run goals and by short-run market fluctuations so that there are no short-run disbenefits from development. We show that these constraints hold for the general case of downward-sloping demand functions and price and of road-sensitive supplies. The results are then extended to case...

This study proposes a method of using ecological1 variables in regression analysis to identify the weak or secondary effects of independent variables without introducing spurious correlation due to aggregation.

1. 1. The inter-ictal random spike and the rhytmical seizure discharge are intimately and specifically related in the genesis of an epileptic seizure, rather than the former being only an “expression” of the latent epileptic condition but unrelated to the seizure per se. 2. 2. In over 90 per cent of observed seizures in cats and monkeys this was not the usually considered relationship (i.e., the increase of frequency and fusion of spikes to form a seizure), but rather one characterized by the interpolation of a new and different form of electrical activity, the afterdischarge. 3. 3. The interrelationship of spike, spike-afterdischarge, and seizure are described and analyzed. 4. 4. The significance of these various electrographic patterns in the problem of localization of epileptogenic foci, as well as their possible practical value in human epilepsy are discussed.

✓ The author presents two cases of compound elevated fractures of the skull and discusses the mechanics of their production. These lesions, seldom recognized in modern clinical practice, are first described in the oldest scientific and surgical treatise known, the Edwin Smith Surgical Papyrus, over 5000 years ago.

Communication is studied here from a supply side point of view. That is, emphasis is placed on supplying information to the public, rather than on the public’s use and evaluation of information. The models used to study the communication channels, however, are based upon well known empirical regularities from the communication and diffusion of innovation literature. The main body of the paper begins with a description of, and the derivation of models for, differing communication channels. The characteristics of changes in agency’s optimal use of these channels are discussed, and accompanied by numerical examples. In the final two sections communication channels are incorporated into two spatial-temporal models. The former, diffusion through an urban system, is implicitly spatial, while the latter, random field models of diffusion, is an explicit spatial-temporal model.

The thalamus is a large and well-differentiated nuclear mass and many of its connections have been worked out anatomically. Primarily, it has been considered to be the end station of most of the sensory systems of the body, being the rccipient of at least seven afferent tracts. Despite this, in cases of tmnors originating in the thalamus, sensory signs and symptoms are not at all prominent. 6 Furthermore, in the operation of chemoor electrothalamectomy, lesions are placed deliberately in the ventrolateral thalamus, and sensory sequelae arc not common. :~ The thalalnus, with special reference to the thalamic reticular system, has been considered to play a role in the coordination of cortical electrical activity and in the maintenance of consciousness. 5 Yet, recent studies of hemispherectomy and hemithalamectomy in the monkey have shown no such disturbance of consciousness, u The most striking result of lesions of the thalamus to date has been the relief of abnormal motor phenomena such as parkinsonism and hemiballismus, results that are hard to understand in the light of present knowledge and physiology? Following a helnidecortication in both monkey and man, there usually is a temporary abolition of all forms of sensation. TM This then is followed by a partial return of sensations of light touch and pinprick over the face and body, but sense of position and other forms of deep sensibility are abolished permanently. Two explanations have been offered to explain the results of hemidecortication: either the thalamus of the ablated side is sufficient to account for the residual sensation or there is ipsilateral representation in the opposite thalamus. Convincing evidence has been advanced to support both points of view. 4 I t is, of course, not possible to perform a hemidecortication without performing a partial thalamectomy as all cortical relay and association nuclei of the thalamus will show retrograde degeneration. 9 The preservation of motor function following hemicorticectomy generally has been attributed to ipsilateral cortical representation rather than to the residual basal ganglia. ~ The results of ablation of the thalamus in primates have not been studied satisfactorily until recently. Although studies of hemidecorticare animals had been made by many observers, it was Mettler 7 who, in 1943, succeeded in removing hemisphere, thalamus and subthalamus in a monkey in two operations. However, it remained for White et al. 11 to develop a single-staged surgical technique that resulted in the survival of most of the animals. They did not attempt to isolate tile afferent arteries first but carried out a sectional removal, entering the 3rd ventricle widely. They noted tile following: State of consciousness--within s 6 hours after the operation, the animal was awake and responding to the environment. I t was never somnolent. The animal would begin to eat ~4-48 hours after the operation and resumed normal hehavioral patterns within ~ weeks. Motor activity there was an initial flaccid hemiplegia, hut the animal was crawling within clays, sitting by 4 days, and walking at 1 week. Timre was excellent motor recovery in ~-3 months, the animal being able to stand, walk, run and climb. I t did not regain fine movements in foot or hand. There was a limited spasticity and a slight hyperreflexia of the involved side without a Babinski's sign. No extrapyramidal symptoms were present. Sensation--there was complete hemianalgesla up to ~ hours. Following this there was gradual improvement, reaching a maximum in 1 month. Response to pin-prick was maximum in the face. Localization was poor and usually limited to recognition of the extremity stimulated. Response to heat was fairly good, apparently being interpreted as painful. There was no response to touch or vibration and tests for sense of position, hopping and placing were absent. Control hemidecorticate animals recovered sensation more rapidly and to a higher degree than (lid hemispherectomized animals. Comparable preparations in man are lacking. As pointed out by Penfield and Evans, S the operation designated as hemispherectomy should in reality be called a hemicorticectomy because every effort is made to spare the thalamus and basal ganglia. Austin and Grant 1 found after "hemispherectomy" complete degeneration of the nucleus ventralis posterolateralis in the presence of pin-prick response, and postulated an ipsilateral thalamic representation.

The pat ient , t a 41-year-old right-handed school-teacher and housewife, had had a subarachnoid hemorrhage without localizing signs at the age of 16 years. She was well until 5 days before her admission, at which time, while a t home, she suddenly experienced severe headache, nausea and vomiting, and became comatose. Lumbar puncture revealed bloody spinal fluid. She was then hospitalized at a local hospital. Neurological examination disclosed a right hemiparesis and some difficulty with speech. She continued to improve until 4 days later when there was an increase in the severity of the symptoms and of the blood in the spinal fluid. She was then transferred to the Mount Sinai Hospital. Examination. She was a noncommunicative, aphasic patient with right-sided weakness, including the face. Right hyperreflexia and Babinski's sign were present. The fundi were normal. There was vertical nystagmus, with paralysis of upward gaze. An electroencephalogram showed severe diffuse slowing, accentuated in the left frontotemporal region. Her state of alertness improved but tile signs persisted. I t was now possible to ascertain that there was no apparent sensory disturbance within the limits of testing and tha t visual fields were full to confrontation. Thirteen days after admission, a left carotid angiogram was carried out. I t showed, in the anteroposterior projection (Fig. 1), a small vascular malformation lying lateral and slightly dorsal to the internal cerebral vein, to which it shunted. The lat ter structure was not shifted across the midline. The malformation seemed to derive most of its blood supply from ganglionic vessels arising inferiorly. The lateral angiogram (Figs. i and 3) also showed the malformation and its shunt to the dilated internal cerebral vein. The lat ter structure was dislocated upwards, indicating a mass in the thalamic region. The anomaly could be seen to project superiorly to the striatothalamic vein and it was judged that a t least part of it might be in proximity to the left lateral ventricle. For this reason a pneumoencephalogram was carried out. The anteroposterior erect films disclosed marked elevation of the thalamic shadow (Fig. 4), with some irregularity of its roof, possibly indicative of the malformation. The lateral view (Fig. 5) showed a marked general increase of the left thalamic outline with local accentuation anterodorsally, in the area under suspicion. There was no filling of the posterior part of the third ventricle. The impression was that this was an arteriovenous anomaly of the left thalamus which was superficial and had ruptured into the thalamus and the left lateral ventricle. I t was felt that the lesion might be safely approached through the hydrocephalic ventricle, and removed, because of its small size. Operation, Under hypothermia and hypotension, 6 weeks after admission, the left su

1. 1. Focal epileptogenic lesions of one cingulate gyrus are capable of inducing a diffuse bilateral synchrony of the spontaneous and epileptiform activity of both cerebral hemispheres in catsanesthetized with a barbiturate. 2. 2. This synchrony is mediated through subcortical centers, possibly by means of the mesial thalamic reticular formation. 3. 3. These observations offer an experimental basis for the diffuse bilateral synchrony seen in some forms of human epilepsy with origins in the parasagittal, pericallosal cortex.

Experiments were performed in the anesthetized cat. 1.(1) The reticular substance of the midbrain, pons and medulla is capable of responding to the injection of small doses of aqueous penicillin in the same manner as the cerebral cortex and thalamus, i.e. with the production of epileptiform sporadic discharges. 2.(2) Unlike the spiking focus produced in one area of a cerebral hemisphere or lateral in the thalamus, that produced unilaterally in the brain-stem reticular formation is immediately and equally projected to both cerebral cortices. This is also true for the organized ictal episodes. 3.(3) Other areas of the brain-stem which are outside of the reticular substance may react with focal spiking in the manner of cerebral cortical foci.

Le papyrus chirurgical d'EdwinSmith. L'A. critique la traduction de J. H. Breasted (Chicago, 1930), qui n'avait pas de connaissances medicales. Apres avoir presente deux cas de fracture crânienne traites de nos jours, il reexamine le cas n4 du papyrus: "une blessure beante de la tete, avec penetration de l'os et fracture du crâne" selon le texte egyptien. L'A. explique, en se referant aux cas modernes, le sens du mot egyptien archaique psn.