United States Department of the Army

"In The Fifth Discipline, Peter Senge describes how companies can rid themselves of the learning "disabilities" that threaten their productivity and success by adopting the strategies of learning organizations - ones in which new and expansive patterns of thinking are nurtured, collective aspiration is set free, and people are continually learning how to create results they truly desire." "The revised and updated Currency edition of this business classic contains over one hundred pages of new material based on interviews with dozens of practitioners at companies like BP, Unilever, Intel, Ford, HP, Saudi Aramco, and organizations like Roca, Oxfam, and The World Bank. It features a new Foreword about the success Peter Senge has achieved with learning organizations since the book's inception, as well as new chapters on Impetus (getting started), Strategies, Leaders' New Work, Systems Citizens, and Frontiers for the Future."--BOOK JACKET.

The effectiveness of virtual environments (VEs) has often been linked to the sense of presence reported by users of those VEs. (Presence is defined as the subjective experience of being in one place or environment, even when one is physically situated in another.) We believe that presence is a normal awareness phenomenon that requires directed attention and is based in the interaction between sensory stimulation, environmental factors that encourage involvement and enable immersion, and internal tendencies to become involved. Factors believed to underlie presence were described in the premier issue of Presence: Teleoperators and Virtual Environments. We used these factors and others as the basis for a presence questionnaire (PQ) to measure presence in VEs. In addition we developed an immersive tendencies questionnaire (ITQ) to measure differences in the tendencies of individuals to experience presence. These questionnaires are being used to evaluate relationships among reported presence and other research variables. Combined results from four experiments lead to the following conclusions: the PQ and ITQ are internally consistent measures with high reliability; there is a weak but consistent positive relation between presence and task performance in VEs; individual tendencies as measured by the ITQ predict presence as measured by the PQ; and individuals who report more simulator sickness symptoms in VE report less presence than those who report fewer symptoms.

A novel reversible data hiding algorithm, which can recover the original image without any distortion from the marked image after the hidden data have been extracted, is presented in this paper. This algorithm utilizes the zero or the minimum points of the histogram of an image and slightly modifies the pixel grayscale values to embed data into the image. It can embed more data than many of the existing reversible data hiding algorithms. It is proved analytically and shown experimentally that the peak signal-to-noise ratio (PSNR) of the marked image generated by this method versus the original image is guaranteed to be above 48 dB. This lower bound of PSNR is much higher than that of all reversible data hiding techniques reported in the literature. The computational complexity of our proposed technique is low and the execution time is short. The algorithm has been successfully applied to a wide range of images, including commonly used images, medical images, texture images, aerial images and all of the 1096 images in CorelDraw database. Experimental results and performance comparison with other reversible data hiding schemes are presented to demonstrate the validity of the proposed algorithm.

CONTEXT: The US military has conducted population-level screening for mental health problems among all service members returning from deployment to Afghanistan, Iraq, and other locations. To date, no systematic analysis of this program has been conducted, and studies have not assessed the impact of these deployments on mental health care utilization after deployment. OBJECTIVES: To determine the relationship between combat deployment and mental health care use during the first year after return and to assess the lessons learned from the postdeployment mental health screening effort, particularly the correlation between the screening results, actual use of mental health services, and attrition from military service. DESIGN, SETTING, AND PARTICIPANTS: Population-based descriptive study of all Army soldiers and Marines who completed the routine postdeployment health assessment between May 1, 2003, and April 30, 2004, on return from deployment to Operation Enduring Freedom in Afghanistan (n = 16,318), Operation Iraqi Freedom (n = 222,620), and other locations (n = 64,967). Health care utilization and occupational outcomes were measured for 1 year after deployment or until leaving the service if this occurred sooner. MAIN OUTCOME MEASURES: Screening positive for posttraumatic stress disorder, major depression, or other mental health problems; referral for a mental health reason; use of mental health care services after returning from deployment; and attrition from military service. RESULTS: The prevalence of reporting a mental health problem was 19.1% among service members returning from Iraq compared with 11.3% after returning from Afghanistan and 8.5% after returning from other locations (P<.001). Mental health problems reported on the postdeployment assessment were significantly associated with combat experiences, mental health care referral and utilization, and attrition from military service. Thirty-five percent of Iraq war veterans accessed mental health services in the year after returning home; 12% per year were diagnosed with a mental health problem. More than 50% of those referred for a mental health reason were documented to receive follow-up care although less than 10% of all service members who received mental health treatment were referred through the screening program. CONCLUSIONS: Combat duty in Iraq was associated with high utilization of mental health services and attrition from military service after deployment. The deployment mental health screening program provided another indicator of the mental health impact of deployment on a population level but had limited utility in predicting the level of mental health services that were needed after deployment. The high rate of using mental health services among Operation Iraqi Freedom veterans after deployment highlights challenges in ensuring that there are adequate resources to meet the mental health needs of returning veterans.

BACKGROUND: In the RV144 trial, the estimated efficacy of a vaccine regimen against human immunodeficiency virus type 1 (HIV-1) was 31.2%. We performed a case-control analysis to identify antibody and cellular immune correlates of infection risk. METHODS: In pilot studies conducted with RV144 blood samples, 17 antibody or cellular assays met prespecified criteria, of which 6 were chosen for primary analysis to determine the roles of T-cell, IgG antibody, and IgA antibody responses in the modulation of infection risk. Assays were performed on samples from 41 vaccinees who became infected and 205 uninfected vaccinees, obtained 2 weeks after final immunization, to evaluate whether immune-response variables predicted HIV-1 infection through 42 months of follow-up. RESULTS: Of six primary variables, two correlated significantly with infection risk: the binding of IgG antibodies to variable regions 1 and 2 (V1V2) of HIV-1 envelope proteins (Env) correlated inversely with the rate of HIV-1 infection (estimated odds ratio, 0.57 per 1-SD increase; P=0.02; q=0.08), and the binding of plasma IgA antibodies to Env correlated directly with the rate of infection (estimated odds ratio, 1.54 per 1-SD increase; P=0.03; q=0.08). Neither low levels of V1V2 antibodies nor high levels of Env-specific IgA antibodies were associated with higher rates of infection than were found in the placebo group. Secondary analyses suggested that Env-specific IgA antibodies may mitigate the effects of potentially protective antibodies. CONCLUSIONS: This immune-correlates study generated the hypotheses that V1V2 antibodies may have contributed to protection against HIV-1 infection, whereas high levels of Env-specific IgA antibodies may have mitigated the effects of protective antibodies. Vaccines that are designed to induce higher levels of V1V2 antibodies and lower levels of Env-specific IgA antibodies than are induced by the RV144 vaccine may have improved efficacy against HIV-1 infection.

The automatic recognition of the modulation format of a detected signal, the intermediate step between signal detection and demodulation, is a major task of an intelligent receiver, with various civilian and military applications. Obviously, with no knowledge of the transmitted data and many unknown parameters at the receiver, such as the signal power, carrier frequency and phase offsets, timing information and so on, blind identification of the modulation is a difficult task. This becomes even more challenging in real-world scenarios with multipath fading, frequency-selective and time-varying channels. With this in mind, the authors provide a comprehensive survey of different modulation recognition techniques in a systematic way. A unified notation is used to bring in together, under the same umbrella, the vast amount of results and classifiers, developed for different modulations. The two general classes of automatic modulation identification algorithms are discussed in detail, which rely on the likelihood function and features of the received signal, respectively. The contributions of numerous articles are summarised in compact forms. This helps the reader to see the main characteristics of each technique. However, in many cases, the results reported in the literature have been obtained under different conditions. So, we have also simulated some major techniques under the same conditions, which allows a fair comparison among different methodologies. Furthermore, new problems that have appeared as a result of emerging wireless technologies are outlined. Finally, open problems and possible directions for future research are briefly discussed.

The present study integrates role theory, social exchange, organizational citizenship, and climate research to suggest that employees will reciprocate implied obligations of leadership-based social exchange (e.g., leader-member exchange [LMX]) by expanding their role and behaving in ways consistent with contextual behavioral expectations (e.g., work group climate). Using safety climate as an exemplar, the authors found that the relationship between LMX and subordinate safety citizenship role definitions was moderated by safety climate. In summary, high-quality LMX relationships resulted in expanded safety citizenship role definitions when there was a positive safety climate and there was no such expansion under less positive safety climates. The authors also found that safety citizenship role definitions were significantly related to safety citizenship behavior. Implications for both social exchange theory and safety research are discussed.

BACKGROUND: The organizational context in which nurses practice is important in explaining variation in patient outcomes, but research has been hampered by the absence of instruments to measure organizational attributes empirically. OBJECTIVES: To report on the development and utility of the Revised Nursing Work Index (NWI-R) in measuring characteristics of professional nursing practice environments. METHODS: The NWI-R was used in a national acquired immunodeficiency syndrome (AIDS) care study. The sample consisted of 40 units in 20 hospitals. Of these 20 hospitals, 10 provided AIDS care in both dedicated AIDS units and general medical units, thus introducing to the design an element of internal control. The remaining 10 hospitals were selected through a matching procedure. Three of the matched control hospitals were magnet hospitals. Nurses were recruited into the study if they worked at least 16 hours per week on the study unit. The nurses completed the NWI-R in addition to other measures. RESULTS: A response rate of 86% was attained. Response rates per unit ranged from 73% to 100%. Cronbach's alpha was 0.96 for the entire NWI-R, with aggregated subscale alphas of 0.84 to 0.91. Validity of the NWI-R was demonstrated by the origin of the instrument, its ability to differentiate nurses who worked within a professional practice environment from those who did not, and its ability to explain differences in nurse burnout. CONCLUSION: The NWI-R has been found to capture organizational attributes that characterize professional nursing practice environments.

This article sets forth a simple cellulase assay procedure. Cellulose is variable in nature, insoluble and resistant to enzymatic attack. As a result there have been a bevy of bewildering cellulase assays published that yielded irrational results. Certain protocols focused on the rapidity of the assay while ignoring that only the most readily susceptible cellulose regions were being hydrolyzed. Other assays simplified the system by using modified soluble substrates and yielded results that bore no relationship to the real world hydrolysis of insoluble cellulose. In this study Mandels, Andreotti and Roche utilized a common substrate, Whatman filter paper. Hydrolysis of a 50 mg sample of the paper was followed to roughly 4% degradation, which circumvented the problems of attack of only the most susceptible zones. This common hydrolysis target range also resulted in some balance with regard to the interaction of the several cellulase components. The method was subsequently widely adopted.Douglas E Eveleigh.

This best-selling text focuses on the analysis and design of complicated dynamics systems. CHOICE called it high-level, concise book that could well be used as a reference by engineers, applied mathematicians, and undergraduates. The format is good, the presentation clear, the diagrams instructive, the examples and problems helpful...References and a multiple-choice examination are included.

We present a user-controllable, general-purpose, pseudorandom task graph generator called Task Graphs For Free (TGFF). TGFF creates problem instances for use in allocation and scheduling research. It has the ability to generate independent tasks as well as task sets which are composed of partially ordered task graphs. A complete description of a scheduling problem instance is created, including attributes for processors, communication resources, tasks, and inter-task communication. The user may parametrically control the correlations between attributes. Sharing TGFF&amp;apos;s parameter settings allows researchers to easily reproduce the examples used by others, regardless of the platform on which TGFF is run.

The effect of temperature on the ability of Aedes aegypti to transmit dengue (DEN) 2 virus to rhesus monkeys was assessed as a possible explanation for the seasonal variation in the incidence of dengue hemorrhagic fever in Bangkok, Thailand. In two laboratory experiments, a Bangkok strain of Ae. aegypti was allowed to feed upon viremic monkeys infected with DEN-2 virus. Blood-engorged mosquitoes were separated into two groups and retained at constant temperatures. Virus infection and transmission rates were determined for Ae. aegypti at intervals ranging from 4 to 7 days during a 25-day incubation period. Results of the first experiment for mosquitoes infected with a low dose of DEN-2 virus and maintained at 20, 24, 26, and 30 degrees C, indicated that the infection rate ranged from 25% to 75% depending on the incubation period. However, DEN-2 virus was transmitted to monkeys only by Ae. aegypti retained at 30 degrees C for 25 days. In the second experiment, the infection rate for Ae. aegypti that ingested a higher viral dose, and incubated at 26, 30, 32, and 35 degrees C ranged from 67% to 95%. DEN-2 virus was transmitted to monkeys only by mosquitoes maintained at greater than or equal to 30 degrees C. The extrinsic incubation period was 12 days for mosquitoes at 30 degrees C, and was reduced to 7 days for mosquitoes incubated at 32 degrees C and 35 degrees C. These results imply that temperature-induced variations in the vector efficiency of Ae. aegypti may be a significant determinant in the annual cyclic pattern of dengue hemorrhagic fever epidemics in Bangkok.

In Brief Background: Effective combat trauma management strategies depend upon an understanding of the epidemiology of death on the battlefield. Methods: A panel of military medical experts reviewed photographs and autopsy and treatment records for all Special Operations Forces (SOF) who died between October 2001 and November 2004 (n = 82). Fatal wounds were classified as nonsurvivable or potentially survivable. Training and equipment available at the time of injury were taken into consideration. A structured analysis was conducted to identify equipment, training, or research requirements for improved future outcomes. Results: Five (6%) of 82 casualties had died in an aircraft crash, and their bodies were lost at sea; autopsies had been performed on all other 77 soldiers. Nineteen deaths, including the deaths at sea were noncombat; all others were combat related. Deaths were caused by explosions (43%), gunshot wounds (28%), aircraft accidents (23%), and blunt trauma (6%). Seventy of 82 deaths (85%) were classified as nonsurvivable; 12 deaths (15%) were classified as potentially survivable. Of those with potentially survivable injuries, 16 causes of death were identified: 8 (50%) truncal hemorrhage, 3 (19%) compressible hemorrhage, 2 (13%) hemorrhage amenable to tourniquet, and 1 (6%) each from tension pneumothorax, airway obstruction, and sepsis. The population with nonsurvivable injuries was more severely injured than the population with potentially survivable injuries. Structured analysis identified improved methods of truncal hemorrhage control as a principal research requirement. Conclusions: The majority of deaths on the modern battlefield are nonsurvivable. Improved methods of intravenous or intracavitary, noncompressible hemostasis combined with rapid evacuation to surgery may increase survival. Effective combat trauma management strategies depend on an understanding of the epidemiology of death on the battlefield. A review of photographs and autopsy and treatment records of 82 combat deaths classified the majority as nonsurvivable. Twelve (15%) deaths identified as potentially survivable led us to conclude that improved methods of intravenous or intracavitary, noncompressible hemostasis, and rapid evacuation may increase survival.

The ultraviolet (UV)/ozone surface cleaning method is reviewed. The UV/ozone cleaning procedure is an effective method of removing a variety of contaminants from surfaces. It is a simple-to-use dry process which is inexpensive to set up and operate. It can rapidly produce clean surfaces, in air or in a vacuum system, at ambient temperatures. By placing properly precleaned surfaces within a few millimeters of an ozone producing UV source, the process can produce clean surfaces in less than 1 min. The technique is capable of producing near-atomically clean surfaces, as evidenced by Auger electron spectroscopy, ESCA, and ISS/SIMS studies. Topics discussed include: the variables of the process,the types of surfaces which have been successfully cleaned, the contaminants which can be removed, the construction of a UV/ozone cleaning facility, the mechanism of the process, UV/ozone cleaning in vacuum systems, rate enhancement techniques, safety considerations, effects of UV/ozone other than cleaning, and applications.

The temperature-dependent linewidths of excitons in semiconductors due to the interaction of the exciton with both LO phonons and with acoustic phonons are studied with use of a Green's-function approach in which the exciton-phonon interaction is treated perturbatively. The interaction between the excitons and the LO phonons is taken to be of the Fr\"ohlich form, and the contribution to the linewidth is obtained in closed form. In this case it is found that scattering of the exciton to both bound and continuum states is important and that it is important to treat the continuum states fully as Coulomb scattering states. In describing optical-absorption processes, the fact that absorption occurs from polariton states, which are states composed of excitons coupled to light, is taken into account. The linewidths due to the exciton--LO-phonon interaction are evaluated for a series of II-VI and III-V compound semiconductors, and are shown to account for the existing experimental results for temperatures \ensuremath{\gtrsim}80 K. The contributions to the linewidth due to the interaction of excitons with acoustic phonons via both the deformation potential and the piezoelectric couplings are treated, and it is found that the deformation-potential coupling dominates for all of the materials considered. Because of the small velocity of sound, scattering to only intraband intermediate states, i.e., those in which the internal exciton quantum numbers do not change, is found to contribute to the linewidth. In the case of acoustic phonons, it is found to be important to treat optical absorption as originating from polariton states in order to evaluate properly the magnitude of this contribution to the linewidth. The acoustic-phonon contribution to the linewidths is compared with experiment for temperatures \ensuremath{\lesssim}80 K, for which it dominates the temperature dependence.

Abstract Modelling of erosion and deposition in complex terrain within a geographical information system (GIS) requires a high resolution digital elevation model (DEM), reliable estimation of topographic parameters, and formulation of erosion models adequate for digital representation of spatially distributed parameters. Regularized spline with tension was integrated within a GIS for computation of DEMs and topographic parameters from digitized contours or other point elevation data. For construction of flow lines and computation of upslope contributing areas an algorithm based on vector-grid approach was developed. The spatial distribution of areas with topographic potential for erosion or deposition was then modelled using the approach based on the unit stream power and directional derivatives of surface representing the sediment transport capacity. The methods presented are illustrated on study areas in central Illinois and the Yakima Ridge, Washington.

STUDY DESIGN: A prospective, cohort study of patients with nonradicular low back pain referred to physical therapy. OBJECTIVE: Develop a clinical prediction rule for identifying patients with low back pain who improve with spinal manipulation. SUMMARY OF BACKGROUND DATA: Development of clinical prediction rules for classifying patients with low back pain who are likely to respond to a particular intervention, such as manipulation, would improve clinical decision-making and research. METHODS: Patients with nonradicular low back pain underwent a standardized examination and then underwent a standardized spinal manipulation treatment program. Success with treatment was determined using percent change in disability scores over three sessions and served as the reference standard for determining the accuracy of examination variables. Examination variables were first analyzed for univariate accuracy in predicting success and then combined into a multivariate clinical prediction rule. RESULTS: Seventy-one patients participated. Thirty-two had success with the manipulation intervention. A clinical prediction rule with five variables (symptom duration, fear-avoidance beliefs, lumbar hypomobility, hip internal rotation range of motion, and no symptoms distal to the knee) was identified. The presence of four of five of these variables (positive likelihood ratio = 24.38) increased the probability of success with manipulation from 45% to 95%. CONCLUSION: It appears that patients with low back pain likely to respond to manipulation can be accurately identified before treatment.

Many approaches to Bayesian image segmentation have used maximum a posteriori (MAP) estimation in conjunction with Markov random fields (MRF). Although this approach performs well, it has a number of disadvantages. In particular, exact MAP estimates cannot be computed, approximate MAP estimates are computationally expensive to compute, and unsupervised parameter estimation of the MRF is difficult. The authors propose a new approach to Bayesian image segmentation that directly addresses these problems. The new method replaces the MRF model with a novel multiscale random field (MSRF) and replaces the MAP estimator with a sequential MAP (SMAP) estimator derived from a novel estimation criteria. Together, the proposed estimator and model result in a segmentation algorithm that is not iterative and can be computed in time proportional to MN where M is the number of classes and N is the number of pixels. The also develop a computationally efficient method for unsupervised estimation of model parameters. Simulations on synthetic images indicate that the new algorithm performs better and requires much less computation than MAP estimation using simulated annealing. The algorithm is also found to improve classification accuracy when applied to the segmentation of multispectral remotely sensed images with ground truth data.

Low-dimensional materials have been examined as electrocatalysts for the hydrogen evolution reaction (HER). Among them, two-dimensional transition metal dichalcogenides (2D-TMDs) such as MoS2 have been identified as potential candidates. However, the performance of TMDs toward HER in both acidic and basic media remains inferior to that of noble metals such as Pt and its alloys. This calls for investigating the influence of controlled defect engineering of 2D TMDs on their performance toward hydrogen production. Here, we explored the HER activity from defective multilayered MoS2 over a large range of surface S vacancy concentrations up to 90%. Amorphous MoS2 and 2H MoS2 with ultrarich S vacancies demonstrated the highest HER performance in acid and basic electrolytes, respectively. We also report that the HER performance from multilayered MoS2 can be divided into two domains corresponding to “point defects” at low concentrations of surface S vacancies (Stage 1) and large regions of undercoordinated Mo atoms for high concentrations of surface S vacancies (Stage 2). The highest performance is obtained for Stage 2 in the presence of undercoordinated Mo atoms with a TOF of ∼2 s–1 at an overpotential of 160 mV in 0.1 M KOH which compares favorably to the best results in the literature. Overall, our work provides deeper insight on the HER mechanism from defected MoS2 and provides guidance for the development of defect-engineered TMD-based electrocatalysts.

STUDY DESIGN: A blinded, prospective diagnostic test study was conducted. OBJECTIVES: To assess the reliability and accuracy of individual clinical examination items and self-report instruments for the diagnosis of cervical radiculopathy, and to identify and assess the accuracy of an optimum test-item cluster for the diagnosis of cervical radiculopathy. SUMMARY OF BACKGROUND DATA: Although cervical radiculopathy remains largely a clinical diagnosis, the reliability and diagnostic accuracy of clinical examination items, individually or in combination, for cervical radiculopathy is largely unknown. METHODS: Patients with suspected cervical radiculopathy or carpal tunnel syndrome received standardized electrophysiologic examination of the symptomatic upper quarter followed by a standardized clinical examination by physical therapist examiners blinded to diagnosis. Diagnostic properties were assessed using a neural impairment reference criterion standard. RESULTS: The study involved 82 patients. More than two thirds of 34 clinical examination items had reliability coefficients rated at least fair or better, and 13 items had likelihood ratio point estimates above 2 or below 0.50. A single diagnostic test item cluster of four variables was identified and produced a positive likelihood ratio point estimate of 30.3. The 95% confidence intervals for all likelihood ratio point estimates in this study were wide. CONCLUSIONS: Many items of the clinical examination were found to be reliable and to have acceptable diagnostic properties, but the test item cluster identified was more useful for indicating cervical radiculopathy than any single test item. Upper limb tension Test A was the most useful test for ruling out cervical radiculopathy. Further investigation is required both to validate the test item cluster and to improve point estimate precision.