bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Kanamycin Using Flow Injection Analysis Coupled with Resonance Rayleigh Scattering Detection
Authors: Hu Xiaoli , Liu Shaopu , Liu Zhongfang
Published: February 2006

A flow injection analysis (FIA) method coupled with resonance Rayleigh scattering (RRS) detection for the determination of kanamycin sulfate (KANA) was developed. The method is based on the ion-association reaction of KANA with acid triphenylmethane dyes such as aniline blue W. S (AB) and methyl blue (MB) by virtue of electrostatic and hydrophobic interaction forces, which results in a significant enhancement of RRS intensity; their maximum scattering peaks are all at 346 nm. The optimum conditions of the reactions and the flow-through parameters including the length of reaction tubing, the flow rate of the carrier stream and the sample injection volume are discussed in this paper. Under the optimum experimental conditions, the linear ranges for both systems are 0.02–12.0 μg mL−1. The detection limits (3σ) are 4.2 ng mL−1 for the AB system and 5.0 ng mL−1 for the MB system and the relative standard deviation for 9 replicate measurements of 2.0 μg mL−1 KANA solution was 1.1%. The proposed method was successfully applied to the determination of KANA in commercial KANA injection, urine and serum samples, and the sample throughput was 30 h−1.
Hydrothermally Controlled Growth of MnPO4·H2O Single-Crystal Rods
Authors: Zhang Yuanguang , Liu Yi , Fu Shengquan , Guo Fan , Qian Yitai
Published: February 2006

Rod-like MnPO4·H2O single crystallites were hydrothermally prepared by the reaction of Mn(NO3)2 with H3PO4 at 130 °C for 16 h. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), infrared spectrum (IR), and their magnetic properties were evaluated on a vibrating sample magnetometer (VSM). The synthesized single-crystal rods have diameters of 0.1–0.66 μm and lengths of up to several micrometers. The influences of different phosphates, the volume ratio between reaction materials, reaction temperature, and reaction time on the morphology and phase of the final products under hydrothermal conditions are discussed. A possible formation mechanism has been proposed on the growth of MnPO4·H2O single-crystal rods.
Systematic Change in Stacking Structure Induced by Alkyl Chains and Spectral Change Due to Hetero-Aggregation in [Ni(dmit)2]− Salts of Methylene Blue Analogues
Authors: Soneta Yuji , Miyamura Kazuo
Published: February 2006

A series of [Ni(dmit)2]− (dmit = 2-thioxo-1,3-dithiole-4,5-dithiolato) salts of 3,7-bis(dialkylamino)phenothiazin-5-ium (alkyl = methyl (C1S), ethyl (C2S), propyl (C3S), and butyl (C4S)) together with those of 3,7-bis(diallylamino)phenothiazin-5-ium (AS) and 3,7-bis(diethylamino)phenoxazin-5-ium (C2O) have been prepared and analyzed by X-ray crystal structural analysis and diffuse reflectance spectra. All complex salts formed stacking columns containing cations and anions. In the crystal structure of (C1S)[Ni(dmit)2], both C1S cations and [Ni(dmit)2]− anions were found to form stacked dimers, and these dimers piled up alternately in columns. In the cases of (C2S)[Ni(dmit)2], (AS)[Ni(dmit)2], and (C2O)[Ni(dmit)2], cations and anions piled up alternately in the form of monomers. In the cases of (C3S)[Ni(dmit)2] and (C4S)[Ni(dmit)2], one anion was sandwiched between two cation dimers to form columns, and another anion layed between these columns. An absorption band appeared at 516–566 nm in the diffuse reflectance spectra, which originated from the absorption of blue cationic dyes, exhibited a large shift by the intermolecular interaction of cation–cation and cation–anion π-stacking. Compounds of (C1S)[Ni(dmit)2] and (C2O)[Ni(dmit)2] were found to behave as semiconductors, exhibiting room temperature conductivities of 3.8 × 10−6 and 4.5 × 10−7 S cm−1, respectively.
Different Z/E-Selectivity Depending upon the Length of the Acyl Side Chain in the Formation of 2,2′-Diacyl-9,9′-bifluorenylidene
Authors: Oota Atsushi , Imai Toshinobu , Yamazaki Ayumi , Oba Toru , Karikomi Michinori , Minabe Masahiro
Published: February 2006

We studied the formation of 2,2′-diacyl-9,9′-bifluorenylidene from 2-acyl-9-bromofluorene via the corresponding intermediate 9-bromo-9,9′-bifluorenyl. It was found that dehydrobromination of the 9-bromo-9,9′-bifluorenyl derivatives occurred through the E2 elimination sequence, suggesting that the configuration of 9-bromo-9,9′-bifluorenyl isomers determined the stereochemistry of the product. Facile isomerization of the formed 9,9′-bifluorenylidenes may give the observed stereo-selectivity depending upon the length of the acyl side chain.
Preparation and Properties of Mg/Al Layered Double Hydroxide–Oleate and –Stearate Intercalation Compounds
Authors: Inomata Kazuya , Ogawa Makoto
Published: February 2006

Mg/Al layered double hydroxide–oleate and –stearate intercalation compounds were successfully synthesized by the reconstruction method under hydrothermal conditions from calcined hydrotalcite. The intercalation compounds were characterized by the high structural regularity as evidenced by the sharp and intense X-ray diffraction peaks. The oleate intercalated layered double hydroxide exhibits unique physicochemical properties such as a reversible thermoresponsive change in the basal spacing and swelling in organic solvents such as n-alkanes.
External reference panel meeting of the Specialist Library for Surgery, Theatres and Anaesthesia
Authors: Homer Kate , Bishop Tom
Published: February 2006

The first external reference panel meeting of the Specialist Library for Surgery, Theatres and Anaesthesia (see the web watch article in the January 2006 Bulletin) was held at the College on 29 November 2005. The 30 attendees included representatives of clinical and non-clinical specialist organisations, senior staff from our College and the Royal College of Anaesthetists, and representatives from NHS Connecting for Health (NHS CFH).
Faculty of Dental Surgery: thriving postgraduate education
Authors: Shepherd Jonathan
Published: February 2006

Postgraduate education continues to be a core role for the Faculty of Dental Surgery which has a team of first-class College staff in this area, led by Fatima Bulbulia, committed to the educational needs of UK and international dental surgeons. The team includes Professor St John Crean (Robert Bradlaw Adviser) and Ms Zarina Sheik (Faculty Educational Tutor), who bring enormous vitality to the postgraduate programme.
Acute Respiratory Failure with a Single Dose of Quetiapine Fumarate
Authors: Jabeen Seema , Polli Stephanie I , Gerber David R
Published: February 2006

Objective:

To report a case of acute respiratory failure after a single dose of quetiapine fumarate in an elderly patient with a history of chronic obstructive pulmonary disease (COPD).

Case Summary:

A 92-year-old woman with a history of COPD was admitted to the hospital with pneumonia. Her symptoms improved with antibiotics. Because of acute agitation and delirium, quetiapine 50 mg twice daily was started. After receiving the first dose, the woman developed acute respiratory failure and severe central nervous system depression. She required mechanical ventilation and supportive care in the intensive care unit (ICU). She had a full recovery within 24 hours.

Discussion:

Quetiapine is an atypical antipsychotic that has been used successfully for the treatment of schizophrenia and bipolar disorder for many years. Recently, it has also been used to treat delirium and agitation. It has proven to be very safe, even in the elderly. In previously reported cases, serious adverse effects were seen in patients who ingested very high doses of quetiapine. Those patients required intubation and supportive care in the ICU. To our knowledge, as of January 19, 2006, this is the first case report of acute respiratory failure of such severity with one dose of quetiapine. Using the Naranjo probability scale, we conclude that the acute respiratory failure observed in this patient was probably related to quetiapine.

Conclusions:

This case suggests that quetiapine can have significant adverse effects even with a single 50 mg dose. Elderly patients, especially those with significant underlying pulmonary pathology, should be monitored closely when started on this medication.
State Creation in Nigeria: Failed Approaches to National Integration and Local Autonomy
Authors: Alapiki Henry E.
Published: February 2006

This paper seeks to demonstrate how the fissiparous tendencies bearing on the Nigerian national polity make the policy of using state creation to achieve national integration a failed strategy. The paper shows how the outcomes of state creation exercises in Nigeria have failed to assuage the very forces that instigate new state demands. It contends that the prospects for national integration and local autonomy depend on the emergence of a purposeful national leadership and proper political restructuring of the federation designed to generate a national image that has more appeal than the regional ones.
Identities in Transition: Shifting Conceptions of Home among “Black” South African University Students
Authors: Bangeni Bongi , Kapp Rochelle
Published: February 2006

This paper is drawn from a longitudinal case study in which we are tracking the progress of twenty students as they pursue their undergraduate degrees at the University of Cape Town. In this paper we trace two first-generation university students' changing constructions of who they are and the concomitant changes in their relationship to home and university over the course of three years. We describe their struggles to present coherent “home” identities and the ways in which these identities are challenged by both the dominant discourses of the institution and by rejection by their home communities. The research questions conventional notions that students from marginalized communities are either alienated from, or uncritically assimilated into, dominant institutional discourses.
Foreign Aid and Democratization: Benin and Niger Compared
Authors: Gazibo Mamoudou
Published: February 2006

This article compares the democratization process in Benin and Niger in the decade from 1989 to 1999 and emphasizes the influence of external donors with regard to their economic support of democratization. The task is twofold. First, I try to understand why, though these two aid-dependent countries share many initial similarities, the former received more external financial assistance than the latter. I build upon New Institutionalist concepts such as timing, sequence, and path dependency to demonstrate that the probability and continuity of foreign aid depend both on the timing and on sequences of the transition—a combination that may or may not produce a path-dependent phenomenon with regard to the donors. Second, I argue that the capacity of foreign aid to foster democratization depends largely on its timing, particularly in critical moments of the democratic process.
NgomaMemories: How Ritual Music and Dance Shaped the Northern Kenya Coast
Authors: Gearhart Rebecca
Published: February 2006

This essay integrates ethnographic data collected between Mombasa and the Lamu archipelago in Kenya into the growing body of scholarship on Swahili music and dance (ngoma) traditions. The analysis underscores how the Swahili have used ngoma events to stake claims to higher positions on the social ladder, negotiate difference, create socioeconomic security networks, establish and mark group identity, connect to the spirit world, and pass through various stages of the life cycle. Through a rich array of historical accounts by visitors to the coast, whose texts complement oral histories of coastal residents, the importance of ngoma in the Swahili-ization of the East African coast becomes apparent. A comprehensive understanding of the part ngoma organizations have played in the recreation and re-creation of Swahili society is possible only when one factors in the contributions made by residents of the northernmost portion of the “Swahili coast.”
Lending a Voice to the Voiceless: The Quest for Justice in Umutesi's Narrative
Authors: Habimana Aloys
Published: February 2006

Surviving the Slaughter is a powerful narrative that takes us into one of the many tragedies of the African Great Lakes region that affected tens of thousands of helpless Rwandan civilians in the aftermath of the 1994 genocide inside Rwanda. Through the eyes of an ordinary, but also remarkable, woman, we learn the horrifying details of the ordeals that Rwandan refugees in the eastern part of the Democratic Republic of the Congo (DRC) went through after their camps were destroyed manu militari. The value of this book goes beyond that of a simple narrative. As we read it, we are absorbed by an account of a breathtaking and excruciating journey of tens of thousands of people as they are hunted down in the dense rainforests of the Congo. At the core of this account is one woman's protest against the absurdity of mass violence and the inhuman brutality of military regimes.

At first glance, the book stands out as a strong stand against the corrosive tradition of silence that often accompanies gross violations of human rights, especially those unfolding beyond the scrutiny of the major world media. In a simple but engaging style, Umutesi strips off the usual veneer of reserve that characterizes Rwandans in general and Rwandan women in particular. Rwandans don't usually talk about their experiences, let alone write about them. And writing about the plight of people whom the world has often considered pariahs since the 1994 genocide requires a strong personality.
On Behalf of Ordinary People: Bridging the Gap between High Politics and Simple Tragedies
Authors: de Lame Danielle
Published: February 2006

Without minimizing the horrors of the genocide in Rwanda in 1994, the book by Marie Béatrice Umutesi,Fuir ou mourir au Zaïre(“Running Away or Dying in Zaïre,” L'Harmattan, 2000), published under the English titleSurviving the Slaughter: The Ordeal of a Rwandan Refugee in Zaire” throws a much needed light on the plight of Rwandan refugees in Kivu from the time they fled Rwanda, many of them as ordinary, peaceful citizens. If we want to understand the events that continue to unfold in the region, and if we want to improve the aid humanitarian agencies provide, we need to consider Umutesi's story—a story in which distant international organizations, with their own views and objectives, took actions that had deleterious consequences for ordinary people.

While some refugees pursued dubious policies in the camps, people of good will went on helping others while they all were in exile. Their collective support systems helped them retain their dignity under the worst of circumstances and, when their fragile safe haven came under attack, helped them endure a hell that seemed at times unendurable. Telling the complete history, as Jan Vansina helped to do in his recent book (2004), and putting ordinary people back into the picture, are the surest ways to avoid lethal stereotypes and quick categorizations that hinder our understanding of complex situations and produce simplifications that contribute to more injustice.
Bearing Witness to Mass Murder
Authors: Lemarchand René
Published: February 2006

The third day after leaving Tingi-Tingi we began to pass the bodies of the dead and the dying.… My eye fell on a teenager hardly sixteen years old. Like the others she was lying at the side of the road, her large eyes open.… A cloud of flies swarmed around her. Ants and other forest insects crawled around her mouth, nose, eyes and ears. They began to devour her before she had taken her last breath. The death rattle that from time to time escaped her lips showed that she was not yet dead. All who passed by glanced at her and then took up their conversation where they had left off. I stood in a daze in front of this sixteen-year-old girl, lying in agony by the side of the road in die middle of the equatorial forest more than five hundred kilometers from home. As in 1993, when I heard about the extermination of my mother's family, as in 1994, when I saw the burned houses, the fear in the eyes of the fleeing Tutsi, and the arrogance and the hate in the faces of their executioners, as in 1995 when I saw pictures of women and children assassinated by the RPF in the camps at Birava, I was overcome by revulsion. What crime had all these victims committed to deserve such a death?

Marie Béatrice Umutesi, Surviving the Slaughter

In the “witness literature” on the Great Lakes, Marie Béatrice Umutesi's wrenching narrative surpasses all others by its searing, intensely personal quality. She bears testimony to an almost forgotten tragedy: Between October 1996 and September 1997, hundreds of thousands of Hutu refugees lost their lives in the course of a massive manhunt carried out by Rwandan-backed rebels and units of the Rwandan army.
Suffering and Survival in Central Africa
Authors: Newbury Catharine
Published: February 2006

In this remarkable book, Marie Béatrice Umutesi recounts what she saw and experienced in Rwanda before and during the 1994 genocide, and as a refugee in Zaire after the genocide. With its intense local level perspective, her study provides fresh insights into the Rwanda genocide and its antecedents, the massacre of Rwandan refugees during the war in Zaire of the mid-1990s, and the utter failure of the international media to understand what was happening there on the ground. Eschewing extremism of all sides, Umutesi records the experiences of ordinary people buffeted by violent events and broader political dynamics they could not control. She is a perspicacious observer—astute, courageous, engaged, and compassionate. One of the remarkable features of this narrative, however, is how little Umutesi appears in this text; it is about her experiences, to be sure, but not about “her.” It is as a testimonial to the times and the human experiences of those times that this tale has such force.

The initial chapters ofSurviving the Slaughterrecount Umutesi's experiences as a student in the 1970s and mid-1980s and (having completed her university education) as a young adult managing rural development programs. Ethnic distinctions between Hutu and Tutsi held litde importance for Umutesi and her friends while she was growing up. Instead, as a Hutu from the north, she found that regional tensions among Hutu were important during the 1980s, under the Second Republic of Juvenal Habyarimana, when she witnessed regionalism in high school and college in Rwanda. Only later, when studying in Belgium, did ethnic distinctions and discrimination between Hutu and Tutsi come into play. The examples she describes show both the contingent nature of ethnic categorization and identities in Rwanda, and the importance of politics in shaping their salience.
Marie Béatrice Umutesi's Truth: The Other Rwanda Genocide?
Authors: Songolo Aliko
Published: February 2006

Une tragédie n'exclut pas l'autre

et il n'existe aucune hiérarchie dans la souffrance.

(One tragedy does not cancel out the other,

and there is no hierarchy in suffering.)

Calixthe Beyala (2005)

There can be no reconciliation between Hutu and Tutsi without

justice, and no justice without truth. This proposition holds true

for all three states of former Belgian Africa.

René Lemarchand (1998)

The title of Marie Béatrice Umutesi's book, Fuir ou mourir au Zaïre: Le vécu d'une Réfugiée Rwandaise—or in its English version, Surviving the Slaughter: The Ordeal of a Rwandan Refugee in Zaïre—might prove confusing for some readers on at least two counts. Because the name Rwanda will forever be associated in our memory with the horror of the 1994 genocide, one might surmise that this is the story of a Tutsi survivor taking refuge in neighboring Zaire, as in previous massacres in 1959, 1963, and 1973. But then again, considering the disastrous wars that have raged in that country for the last decade, one might conclude that Umutesi's book tells the story of a Rwandan refugee caught in the crossfire between competing forces, Rwanda versus Uganda and their proxies within the former Zaire. Both assumptions would be only half true. The missing half in both inferences is that the ordeal of this refugee and her cohort originated in the Rwandan conflict that began in 1990 and culminated in the genocide four years later. Shrewdly orchestrated and largely perpetrated by the Tutsi-dominated regime that took power in Rwanda in the aftermath of the genocide, the slaughter of these Hutu refugees has been concealed behind a curtain of silence on the part of the international community. In the drama that unfolds in Umutesi's book, Zairian territory is the unwitting, albeit highly significant, theater of the cynically suppressed story of the disappearance of nearly a quarter million Hutu refugees from Rwanda at the hands of shadowy “rebels.”
Displaying Uncertainty: Investigating the Effects of Display Format and Specificity
Authors: Bisantz Ann M. , Marsiglio Stephanie Schinzing , Munch Jessica
Published: February 2006

We conducted four studies regarding the representation of probabilistic information. Experiments 1 through 3 compared performance on a simulated stock purchase task, in which information regarding stock profitability was probabilistic. Two variables were manipulated: display format for probabilistic information (blurred and colored icons, linguistic phrases, numeric expressions, and combinations) and specificity level (in which the number and size of discrete steps into which the probabilistic information was mapped differed). Results indicated few performance differences attributable to display format; however, performance did improve with greater specificity. Experiment 4, in which participants generated membership functions corresponding to three display formats, found a high degree of similarity in functions across formats and participants and a strong relationship between the shape of the membership function and the intended meaning of the representation. These results indicate that participants can successfully interpret nonnumeric representations of uncertainty and can use such representations in a manner similar to the way numeric expressions are used in a decision-making task. Actual or potential applications of this research include the use of graphical representations of uncertainty in systems such as command and control and situation displays.
Radiant Heat and Thermal Comfort in Vehicles
Authors: Devonshire Joel M. , Sayer James R.
Published: February 2006

Infrared-reflective (IRR) treatment of automotive glass has been shown to reduce air temperature in vehicle cabins, thereby increasing fuel economy and occupant comfort. Its effect on radiant heat, however, may augment these benefits. In this study, the hypothesis that radiant heat affects subjective comfort ratings in a vehicle was tested. IRR films were systematically applied to the driver-side window of an outdoor stationary vehicle. In Phase 1, cabin air temperature was controlled while participants rated their thermal comfort. In Phase 2, air temperature was adjusted according to participants' responses. Results in Phase 1 showed that the IRR treatment improved thermal comfort on the left forearm, which was exposed to direct solar irradiance, but not whole-body thermal comfort. In Phase 2, participants indicated that they were comfortable at a higher air temperature (mean of 2.5°F [1.4°C]) with the IRR treatment than in the untreated condition. The results indicate that reducing radiant heat via IRR treatment affects subjective assessments of thermal comfort and allows occupants to maintain the same level of comfort in a warmer vehicle cabin. Applications of this research include future implementations of IRR treatment on automotive glass that may lead to greater fuel economy savings and occupant comfort than have previously been estimated.
Individual Perception of Noise Exposure and Hearing Protection in Industry
Authors: Arezes Pedro M. , Miguel A. Sèrgio
Published: February 2006

Existing approaches that explain the behavior of workers in noisy environments rarely include quantitative variables related to central factors such as noise exposure levels and workers' hearing status. The aim of this study is to analyze the relationship among individual, contextual, and perceptual-cognitive factors and the use of hearing protection devices (HPDs). We studied 516 industrial workers exposed to noise levels greater than the Portuguese action level and developed a conceptual model for HPD use. The multivariate data analysis of the several variables considered revealed that individual risk perception and the outcome value for hearing preservation were the main direct predictors of the use of HPDs. Workers' opinions about the company's safety climate and their perception of noise exposure effects also play important roles as predictors. However, much of the effects of these factors are indirect (i.e., mediated by other variables). Furthermore, these results suggest that risk perception should be considered an essential issue in the design and implementation of any hearing conservation program, particularly in the development of training programs. Actual or potential applications of this research include the definition of more accurate strategies for promoting and motivating the use of HPDs.
Characteristics of Fluent Skills in a Complex, Dynamic Problem-Solving Task
Authors: Sohn Myeong-Ho , Douglass Scott A. , Chen Mon-Chu , Anderson John R.
Published: February 2006

We examined critical characteristics of fluent cognitive skills, using the Georgia Tech Aegis Simulation Program, a tactical decision-making computer game that simulates tasks of an anti-air-warfare coordinator. To characterize learning, we adopted the unit-task analysis framework, in which a task is decomposed into several unit tasks that are further decomposed into functional-level subtasks. Our results showed that learning at a global level could be decomposed into learning smaller component tasks. Further, most learning was associated with a reduction in cognitive processes, in which people make inferences from the currently available information. Eye-movement data also revealed that the time spent on task-irrelevant regions of the display decreased more than did the time spent on task-relevant regions. In sum, although fluency in dynamic, complex problem solving was achieved by attaining efficiency in perceptual, motor, and cognitive processes, the magnitude of the gains depended on the preexisting fluency of the component skills. These results imply that a training program should decompose a task into its component skills and emphasize those components with which trainees have relatively little prior experience. Actual or potential applications of this research include learning and training of complex tasks as well as evaluation of performance on those tasks.
Usability of Touch-Panel Interfaces for Older Adults
Authors: Murata Atsuo , Iwase Hirokazu
Published: February 2006

The usability of a touch-panel interface was compared among young, middle-aged, and older adults. In addition, a performance model of a touch panel was developed so that pointing time could be predicted with higher accuracy. Moreover, the target location to which a participant could point most quickly was determined. The pointing time with a PC mouse was longer for the older adults than for the other age groups, whereas there were no significant differences in pointing time among the three age groups when a touch-panel interface was used. Pointing to the center of a square target led to the fastest pointing time among nine target locations. Based on these results, we offer some guidelines for the design of touch-panel interfaces and show implications for users of different age groups. Actual or potential applications of this research include designing touch-panel interfaces to make them accessible for older adults and predicting movement times when users operate such devices.
Using Eye Movements To Evaluate Effects of Driver Age on Risk Perception in a Driving Simulator
Authors: Pradhan Anuj Kumar , Hammel Kim R. , DeRamus Rosa , Pollatsek Alexander , Noyce David A. , Fisher Donald L.
Published: February 2006

Novice drivers (16-year-olds with ≤6 months' driving experience) have the highest crash involvement rates per 100 million vehicle miles (161 million vehicle km). In the past, this was attributed to greater risk taking or poorly developed psychomotor skills. More recently, however, their high crash involvement rate has been hypothesized to be attributable largely to their relative inability to acquire and assess information in inherently risky situations. The current study seeks to evaluate this hypothesis by recording eye movements while 72 participants (24 novice drivers, 24 younger drivers, and 24 older drivers) drove through 16 risky scenarios in an advanced driving simulator. There were significant age-related differences in driver scanning behavior, consistent with the hypothesis that novice drivers' scanning patterns reflect their failure to acquire information about potential risks and their consequent failure to deal with these risks. Actual or potential applications of this research include modification of these scenarios for display on a PC as a basis for a training module that would enable novice drivers to recognize risky scenarios before they encounter them on the road, in the hope of reducing their high fatality rate.
Bibliometric Analysis of Human Factors (1970-2000): A Quantitative Description of Scientific Impact
Authors: Lee John D. , Cassano-Pinché Andrea , Vicente Kim J.
Published: February 2006

Bibliometric analyses use the citation history of scientific articles as data to measure scientific impact. This paper describes a bibliometric analysis of the 1682 papers and 2413 authors published in Human Factors from 1970 to 2000. The results show that Human Factors has substantial relative scientific influence, as measured by impact, immediacy, and half-life, exceeding the influence of comparable journals. Like other scientific disciplines, human factors research is a highly stratified activity. Most authors have published only one paper, and many papers are cited infrequently, if ever. A small number of authors account for a disproportionately large number of the papers published and citations received. However, the degree of stratification is not as extreme as in many other disciplines, possibly reflecting the diversity of the human factors discipline. A consistent trend of more authors per paper parallels a similar trend in other fields and may reflect the increasingly interdisciplinary nature of human factors research and a trend toward addressing human-technology interaction in more complex systems. Ten of the most influential papers from each of the last 3 decades illustrate trends in human factors research. Actual or potential applications of this research include considerations for the publication and distribution policy of Human Factors.
Adaptive Automation of Human-Machine System Information-Processing Functions
Authors: Kaber David B. , Wright Melanie C. , Prinzel Lawrence J. , Clamann Michael P.
Published: February 2006

The goal of this research was to describe the ability of human operators to interact with adaptive automation (AA) applied to various stages of complex systems information processing, defined in a model of human-automation interaction. Forty participants operated a simulation of an air traffic control task. Automated assistance was adaptively applied to information acquisition, information analysis, decision making, and action implementation aspects of the task based on operator workload states, which were measured using a secondary task. The differential effects of the forms of automation were determined and compared with a manual control condition. Results of two 20-min trials of AA or manual control revealed a significant effect of the type of automation on performance, particularly during manual control periods as part of the adaptive conditions. Humans appear to better adapt to AA applied to sensory and psychomotor information-processing functions (action implementation) than to AA applied to cognitive functions (information analysis and decision making), and AA is superior to completely manual control. Potential applications of this research include the design of automation to support air traffic controller information processing.
Text Legibility and the Letter Superiority Effect
Authors: Sheedy James E. , Subbaram Manoj V. , Zimmerman Aaron B. , Hayes John R.
Published: February 2006

Effects of font design and electronic display parameters upon text legibility were determined using a threshold size method. Participants' visual acuity (inverse of the minimum detection size, representing the threshold legibility for each condition) was measured using upper- and lowercase letters and lowercase words in combinations of 6 fonts, 3 font-smoothing modes, 4 font sizes, 10 pixel heights, and 4 stroke widths. Individual lowercase letters were 10% to 20% more legible than lowercase words (i.e., lowercase words must be 10%-20% larger to have the same threshold legibility). This letter superiority effect suggests that individual letters play a large role and word shape plays a smaller role, if any, in word identification at threshold. Pixel height, font, stroke width, and font smoothing had significant main effects on threshold legibility. Optimal legibility was attained at 9 pixels (10 points). Verdana and Arial were the most legible fonts; Times New Roman and Franklin were least legible. Subpixel rendering (ClearTypeTM) improved threshold legibility for some fonts and, in combination with Verdana, was the most legible condition. Increased stroke width (bold) improved threshold legibility but only at the thinnest width tested. Potential applications of this research include optimization of font design for legibility and readability.
Synthetic Vision Systems: The Effects of Guidance Symbology, Display Size, and Field of View
Authors: Alexander Amy L. , Wickens Christopher D. , Hardy Thomas J.
Published: February 2006

Two experiments conducted in a high-fidelity flight simulator examined the effects of guidance symbology, display size, and geometric field of view (GFOV) within a synthetic vision system (SVS). In Experiment 1, 18 pilots flew highlighted and lowlighted tunnel-in-the-sky displays, as well as a less cluttered follow-me aircraft (FMA), through a series of curved approaches over rugged terrain. The results revealed that both tunnels supported better flight path tracking and lower workload levels than did the FMA because of the availability of more preview information. Increasing tunnel intensity had no benefit on tracking and, in fact, degraded traffic awareness because of clutter and attentional tunneling. In Experiment 2, 24 pilots flew a lowlighted tunnel configured according to different display sizes (small or large) and GFOVs (30° or 60°). Measures of flight path tracking and terrain awareness generally favored the 60° GFOV; however, there were no effects of display size. Actual or potential applications of this research include understanding the impact of SVS properties on flight path tracking, traffic and terrain awareness, workload, and the allocation of attention.
Effects of Aging on the Biomechanics of Slips and Falls
Authors: Lockhart Thurmon E. , Smith James L. , Woldstad Jeffrey C.
Published: February 2006

Although much has been learned in recent decades about the deterioration of muscular strength, gait adaptations, and sensory degradation among older adults, little is known about how these intrinsic changes affect biomechanical parameters associated with slip-induced fall accidents. In general, the objective of this laboratory study was to investigate the process of initiation, detection, and recovery of inadvertent slips and falls. We examined the initiation of and recovery from foot slips among three age groups utilizing biomechanical parameters, muscle strength, and sensory measurements. Forty-two young, middle-age, and older participants walked around a walking track at a comfortable pace. Slippery floor surfaces were placed on the track over force platforms at random intervals without the participants' awareness. Results indicated that younger participants slipped as often as the older participants, suggesting that the likelihood of slip initiation is similar across all age groups; however, older individuals? recovery process was much slower and less effective. The ability to successfully recover from a slip (thus preventing a fall) is believed to be affected by lower extremity muscle strength and sensory degradation among older individuals. Results from this research can help pinpoint possible intervention strategies for improving dynamic equilibrium among older adults.
Effect of Tactile Feedback on Movement Speed and Precision During Work-Related Tasks Using a Computer Mouse
Authors: Viau Antonin , Najm Micheline , Chapman C. Elaine , Levin Mindy F.
Published: February 2006

Effects of tactile feedback on movement accuracy and speed were studied. Younger and older participants performed three tasks (1, select and drag word; 2, menu navigation; 3, select and drag cell) using commercial software and a mouse with or without tactile feedback. Task time and error number were recorded. Tasks were divided according to presence or absence of tactile feedback, and participants were divided into subgroups (high, average, low) based on Task 1 performance. Overall, older participants took longer ( p < .0001) and made more errors ( p < .001) than younger participants. There was an effect of feedback by task in younger participants for all six outcomes ( p < 0.02). At the task level, with feedback, younger participants reduced performance time (13%) and errors (24%) on Task 1. Low-and average-performance younger participants benefited most from feedback for Task 1. Older low-performance participants also benefited from feedback for Task 1. For Task 3, older participants tended to take more time and make more errors with feedback. Tactile feedback may enhance performance when feedback is event related. Older people may not integrate sensation as well as younger individuals to enhance performance. Potential applications of this research include the development of tactile feedback interfaces to facilitate computer use.
SingleIhChannels in Pyramidal Neuron Dendrites: Properties, Distribution, and Impact on Action Potential Output
Authors: Kole Maarten H. P. , Hallermann Stefan , Stuart Greg J.
Published: February 2006

The hyperpolarization-activated cation current (Ih) plays an important role in regulating neuronal excitability, yet its native single-channel properties in the brain are essentially unknown. Here we use variance-mean analysis to study the properties of singleIhchannels in the apical dendrites of cortical layer 5 pyramidal neuronsin vitro. In these neurons, we find thatIhchannels have an average unitary conductance of 680 ± 30 fS (n= 18). Spectral analysis of simulated and nativeIhchannels showed that there is little or no channel flicker below 5 kHz. In contrast to the uniformly distributed single-channel conductance,Ihchannel number increases exponentially with distance, reaching densities as high as ∼550 channels/μm2at distal dendritic sites. These high channel densities generate significant membrane voltage noise. By incorporating a stochastic model ofIhsingle-channel gating into a morphologically realistic model of a layer 5 neuron, we show that this channel noise is higher in distal dendritic compartments and increased threefold with a 10-fold increased single-channel conductance (6.8 pS) but constantIhcurrent density. In addition, we demonstrate that voltage fluctuations attributable to stochasticIhchannel gating impact on action potential output, with greater spike-timing precision in models with the experimentally determined single-channel conductance. These data suggest that, in the face of high current densities, the small single-channel conductance ofIhis critical for maintaining the fidelity of action potential output.
Integrins Control Dendritic Spine Plasticity in Hippocampal Neurons through NMDA Receptor and Ca2+/Calmodulin-Dependent Protein Kinase II-Mediated Actin Reorganization
Authors: Shi Yang , Ethell Iryna M.
Published: February 2006

The formation of dendritic spines during development and their structural plasticity in the adult brain are critical aspects of synaptogenesis and synaptic plasticity. Many different factors and proteins have been shown to control dendritic spine development and remodeling (Ethell and Pasquale, 2005). The extracellular matrix (ECM) components and their cell surface receptors, integrins, have been found in the vicinity of synapses and shown to regulate synaptic efficacy and play an important role in long-term potentiation (Bahr et al., 1997; Chavis and Westbrook, 2001; Chan et al., 2003; Lin et al., 2003; Bernard-Trifilo et al., 2005). Although molecular mechanisms by which integrins affect synaptic efficacy have begun to emerge, their role in structural plasticity is poorly understood. Here, we show that integrins are involved in spine remodeling in cultured hippocampal neurons. The treatment of 14 din vitrohippocampal neurons with arginine–glycine–aspartate (RGD)-containing peptide, an established integrin ligand, induced elongation of existing dendritic spines and promoted formation of new filopodia. These effects were also accompanied by integrin-dependent actin reorganization and synapse remodeling, which were partially inhibited by function-blocking antibodies against β1 and β3 integrins. This actin reorganization was blocked with the NMDA receptor (NMDAR) antagonist MK801 [(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine hydrogen maleate]. The Ca2+/calmodulin-dependent protein kinase II (CaMKII) inhibitor KN93 (N-[2-[N-(4-chlorocinnamyl)-N-methylaminomethyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide) also suppressed RGD-induced actin reorganization and synapse remodeling. Our findings show that integrins control ECM-mediated spine remodeling in hippocampal neurons through NMDAR/CaMKII-dependent actin reorganization.
Steering by Hearing: A Bat’s Acoustic Gaze Is Linked to Its Flight Motor Output by a Delayed, Adaptive Linear Law
Authors: Ghose Kaushik , Moss Cynthia F.
Published: February 2006

Adaptive behaviors require sensorimotor computations that convert information represented initially in sensory coordinates to commands for action in motor coordinates. Fundamental to these computations is the relationship between the region of the environment sensed by the animal (gaze) and the animal’s locomotor plan. Studies of visually guided animals have revealed an anticipatory relationship between gaze direction and the locomotor plan during target-directed locomotion. Here, we study an acoustically guided animal, an echolocating bat, and relate acoustic gaze (direction of the sonar beam) to flight planning as the bat searches for and intercepts insect prey. We show differences in the relationship between gaze and locomotion as the bat progresses through different phases of insect pursuit. We define acoustic gaze angle, θgaze, to be the angle between the sonar beam axis and the bat’s flight path. We show that there is a strong linear linkage between acoustic gaze angle at timet[θgaze(t)] and flight turn rate at timet+ τ into the future [\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \( \stackrel{.}{\theta }\) \end{document}flight(t+ τ)], which can be expressed by the formula\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \( \stackrel{.}{\theta }\) \end{document}flight(t+ τ) =kθgaze(t). The gain,k, of this linkage depends on the bat’s behavioral state, which is indexed by its sonar pulse rate. For high pulse rates, associated with insect attacking behavior,kis twice as high compared with low pulse rates, associated with searching behavior. We suggest that this adjustable linkage between acoustic gaze and motor output in a flying echolocating bat simplifies the transformation of auditory information to flight motor commands.
Increased Vulnerability to Nicotine Self-Administration and Relapse in Alcohol-Naive Offspring of Rats Selectively Bred for High Alcohol Intake
Authors: Lê A. D. , Li Z. , Funk D. , Shram M. , Li T. K. , Shaham Y.
Published: February 2006

The prevalence of smoking in human alcoholics is substantially higher than in the general population, and results from twin studies suggest that a shared genetic vulnerability underlies alcohol and nicotine addiction. Here, we directly tested this hypothesis by examining nicotine-taking behavior in alcohol-naive offspring of alcohol-preferring (P) rats and alcohol-nonpreferring (NP) rats that had been selectively bred for high and low alcohol intake. The self-administration of intravenous nicotine (0.015–0.060 mg/kg per infusion) in P rats was more than twice than that of NP rats. Nicotine seeking induced by reexposure to nicotine cues in extinction tests was also substantially greater in P rats than in NP rats. In a subsequent relapse test, priming nicotine injections reinstated drug seeking in P rats but not NP rats. P rats also self-administered higher amounts of oral sucrose (1–20%) than NP rats, a finding consistent with previous reports. In contrast, self-administration of intravenous cocaine (0.1875–1.125 mg/kg per infusion) was remarkably similar in the P and NP rats; however, P–NP differences in cocaine seeking emerged in subsequent extinction and cocaine priming-induced reinstatement tests. In both cases, lever responding was higher in P rats than in NP rats. Thus, alcohol-naive offspring of rats genetically selected for high alcohol intake are highly susceptible to nicotine self-administration and relapse, and this susceptibility is not likely caused by general reward deficits in NP rats. The present findings provide experimental evidence for the hypothesis that a shared genetic determinant accounts for the co-abuse of nicotine and alcohol.
Etiologic aspects and management of acromegaly
Authors: Taboada Giselle F. , van Haute Flávia R. , Corrêa Lívia L. , Casini Alessandra F. , Gadelha Mônica R.
Published: February 2006

Acromegaly is a systemic disease with various etiologies. It can occur as a sporadic or, more rarely, as a familial disease. Numerous complications such as endocrine, cardiovascular, respiratory, metabolic, osteoarticular and neoplastic disturbances occur and must be taken into account when establishing a therapeutic strategy. For this reason, the decision as to a treatment modality of acromegaly must be followed by a thorough evaluation of the patient and once the diagnosis of complications is settled, adequate treatment should be instituted. Follow up of the patients requires periodical re-assessment of complications’ status.