Herding Cats

Abstract

With the rapid growth in the number of electronic resources available via the Internet, a variety of methods have been developed to organize and access these objects. Librarians, scholars, and computing engineers have each applied their own techniques to the process. This article examines the strengths and weaknesses of organizational systems developed by each group. The appropriateness of including remotely accessed electronic resources as part of a library collection is discussed, and the success of traditional cataloging methods and structures for describing remote electronic resources is examined. These traditional cataloging techniques are compared to other methods for describing, organizing, and accessing electronic documents such as TEI headers, browsing lists, and robot generated search indexes. For Metacatalogs of the future to be successful tools for organizing and accessing all information, methods must be developed to utilize all existing organizational tools by layering, exchanging, and translating data within a loosely-coupled organizational system.     

纳洛酮对大鼠中重度创伤性脑损伤后细胞免疫功能影响的实验研究

目的：通过观察大鼠创伤性脑损伤（traumatic brain injury,TBI）后纳洛酮治疗前后血浆β-EP、CD4＋、CD8＋和IL-2的动态变化,探讨纳洛酮对大鼠TBI后细胞免疫功能变化的影响及作用机制。方法：采用气体冲击致大鼠中重度脑损伤模型;流式细胞术、RIA、ELISA检测血液中CD4＋、CD8＋、β-EP、IL-2的变化。结果：TBI大鼠经纳洛酮治疗后,血浆中CD4＋和IL-2含量升高,β-EP和CD8＋则降低。大、小剂量纳洛酮治疗在相应时间点比较有显著性差异（P〈0.05）。结论：纳洛酮可通过降低TBI大鼠血浆中β-EP,调节TBI后应激紊乱,竞争性抑制β-EP对免疫细胞受体的作用,从而使CD4＋、CD8＋和IL-2水平趋于正常,恢复免疫平衡,起到治疗与保护作用。     

Preface.

Introduces this special issue of Rehabilitation Psychology. This special issue was conceptualized as an effort to bring to the journal's readership an understanding of some of the basic concerns in traumatic brain injury (TBI) rehabilitation from the psychologist's perspective. This issue begins with an overview of the various acute and postacute services in TBI rehabilitation, proceeds to discuss the roles and functions of the psychologist within the TBI rehabilitation setting (principally the postacute setting), and then addresses a range of issues related to assessment and intervention. Because of space limitations, we could not fully cover all the issues in these areas. We certainly believe, however, that the selected authors made ambitious and credible efforts with their assigned topics. The reader, seeking to examine better this disability area and current psychosocial treatment interventions, receives a wealth of practical material and references for further review. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incidence and risk factors of severe traumatic brain injury resulting from road accidents: a population-based study

A population-based study was carried out in 1996-2001 to provide the incidence and to identify the risk factors of severe traumatic brain injury (TBI) resulting from a road accident. The severe TBI was defined as an injury to the brain or the skull, excluding scalp injuries, with an abbreviated injury scale (AIS) severity score greater than 2. The severe TBI of 1238 patients were described. The annual incidence and mortality of severe TBI were, respectively, 13.7 per 100,000 and 5.3 per 100,000. The fatality rate increased from 20% in childhood to 71% over 75-year-old. Compared to restrained car occupants, the odds ratio for having a severe TBI was 18.1 (95% confidence interval, CI=12.8-25.5) for un-helmeted motorcyclists, 9.2 (95% CI=7.5-11.3) for pedestrians, 6.4 (95% CI=4.7-8.8) for un-helmeted cyclists, 3.9 (95% CI=3.1-4.8) for unrestrained car occupants and 2.8 (95% CI=2.2-3.5) for helmeted motorcyclists. Even after adjustment for several severity factors, male gender and age above 55 were both risk factors. Prevention programs aiming at improving the head protection should be promoted. The circumstances of the accident should be taken into account to predict a severe TBI.     

Cognitive Control in Closed Head Injury: Context Maintenance Dysfunction or Prepotent Response Inhibition Deficit?

The authors contrasted 2 potential explanations for the cognitive control deficits observed in closed head injury (CHI): a prepotent response inhibition deficit or a deficit in context maintenance, defined as the guidance of appropriate responding by task-relevant information. Healthy and CHI participants performed the traditional card Stroop task and a single-trial Stroop task sensitive to context maintenance deficits. As predicted by a context maintenance deficit, moderate to severe CHI participants showed higher error rates in the single-trial Stroop task only, and only when task instructions had to be maintained over a long delay. Moreover, context maintenance impairment and generalized slowing were both related to reports of daily functioning in CHI participants. Thus, context maintenance could be a useful framework for characterizing cognitive control deficits in CHI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Crash risk factors related to individuals sustaining and drivers following traumatic brain injuries

Objective

Some crashes result in drivers experiencing (or sustaining) a traumatic brain injury (TBI) while other crashes involve drivers that have already experienced a TBI. The objective of this study is to examine the factors that influence these two TBI crash groups.

Methods

Data from the Iowa Department of Public Health's Brain Injury Registry and Department of Transportation's crash records were linked together and used in logistic regression models to predict the likelihood of a driver sustaining a TBI in a crash and those who drive after a TBI.

Results

Between 2001 and 2006, there were 2382 crashes in which an individual sustained a TBI. As expected, a higher likelihood of sustaining a TBI was observed for motorcycle drivers who did not wear a helmet and in crashes that resulted in total or disabling vehicle damage. Focusing specifically on the post-TBI drivers (and not occupants), 1583 were involved in crashes. These post-TBI drivers were less likely to wear seatbelts or have passengers in the vehicle at the time of the crash, and were more likely to crash at night. Post-TBI drivers were also involved in significantly more multiple crashes (about 14%) when compared to drivers who have not experienced a TBI (about 10%) during the study period. When controlling for gender, date of injury, and severity of TBI (using Glasgow Coma Scale), individuals that sustained a TBI when they were younger were more likely to be involved in multiple crashes.

Conclusions

Different factors influence the crash likelihood for those that sustain a TBI in a crash and those that crash following a TBI. In general, post-TBI drivers have a higher occurrence of multiple crashes and this should be further explored to guide driver rehabilitation, evaluation, and training.     

Biofidelic human brain tissue surrogates

ABSTRACT

Traumatic brain injury (TBI) due to blast exposure or head impacts in accidents or contact sports is one of the most critical and poorly understood areas of research in the 21st century. To date, the unavailability of human brain tissues (grey and white matter especially) due to ethical and biosafety issues has not allowed for much experimental research into the study of the mechanics of brain tissues under impact or dynamic loading. In the current work, for the first time, biofidelic brain tissue surrogates have been developed using a low cost, castable (to any shape or size), two-part silicone-based material system to precisely mimic the nonlinear mechanical properties of both the white and the grey matter. The fabrication methodology involves the iterative mixing of the two parts of silicone at certain mix ratios (by weight) to generate a biomechanical behavior similar to the white and the grey matter tissues, respectively, at two different strain rates (low and high). The nonlinear behavior of these novel brain tissue surrogates have been characterized using five hyperelastic material models. These brain tissue simulant materials would be indispensable not only for the study of TBI, but also to allow doctors to practice brain surgeries (for training purposes) in a clinical setting. Additionally, crucial brain tissue modifications in Alzheimer's disease and dementia can be studied in the future with such accessible biofidelic brain tissue surrogate materials.