Biobehavioral Insights into Adaptive Behavior in Complex and Dynamic Operational Settings: Lessons learned from the Soldier Performance and Effective, Adaptable Response Task.

The purpose of this study was to explore the biobehavioral correlates of adaptive behavior in the context of a standardized laboratory-based mission-relevant challenge [the Soldier Performance and Effective, Adaptable Response (SPEAR) task]. Participants were 26 healthy male volunteers (M = 34.85 years, SD = 4.12) with active military duty and leadership experience within the last 5 years (i.e., multiple leadership positions, operational deployments in combat, interactions with civilians and partner nation forces on the battlefield, experience making decisions under fire). The SPEAR task simultaneously engages perception, cognition, and action aspects of human performance demands similar to those encountered in the operational setting. Participants must engage with military-relevant text, visual, and auditory stimuli, interpret new information, and retain the commander's intent in working memory to create a new plan of action for mission success. Time-domain measures of heart period and respiratory sinus arrhythmia (RSA) were quantified, and saliva was sampled [later assayed for cortisol and alpha-amylase (sAA)] before-, during-, and post-SPEAR. Results revealed a predictable pattern of withdraw and recovery of the cardiac vagal tone during repeated presentation of battlefield challenges. Recovery of vagal inhibition following executive function challenge was strongly linked to better task-related performance. Rate of RSA recovery was also associated with better recall of the commander's intent. Decreasing magnitude in the skin conductance response prior to the task was positively associated with better overall task-related performance. Lower levels of RSA were observed in participants who reported higher rates of combat deployments, and reduced RSA flexibility was associated with higher rates of casualty exposure. Greater RSA flexibility during SPEAR was associated with greater self-reported resilience. There was no consistent pattern of task-related change in cortisol or sAA. We conclude that individual differences in psychophysiological reactivity and regulation in response to an ecologically valid, military-relevant task are associated with performance-related adaptive behavior in this standardized operational setting. The implications for modern day warfare, where advancing our understanding of the nature of individual differences in adaptive problem solving is critical to mission success, fitness for duty, and other occupational health-related outcomes, are discussed.

All-in-fiber chemical sensing.

A new all-in-fiber trace-level chemical sensing approach is demonstrated. Photoconductive structures, embedded directly into the fiber cladding along its entire length, capture light emitted anywhere within the fiber's hollow core and transform it directly into an electrical signal. Localized signal transduction circumvents problems associated with conventional fiber-optics, including limited signal collection efficiency and optical losses. This approach facilitates a new platform for remote and distributed photosensing.

Enhanced chemiluminescent detection scheme for trace vapor sensing in pneumatically-tuned hollow core photonic bandgap fibers.

We demonstrate an in-fiber gas phase chemical detection architecture in which a chemiluminescent (CL) reaction is spatially and spectrally matched to the core modes of hollow photonic bandgap (PBG) fibers in order to enhance detection efficiency. A peroxide-sensitive CL material is annularly shaped and centered within the fiber's hollow core, thereby increasing the overlap between the emission intensity and the intensity distribution of the low-loss fiber modes. This configuration improves the sensitivity by 0.9 dB/cm compared to coating the material directly on the inner fiber surface, where coupling to both higher loss core modes and cladding modes is enhanced. By integrating the former configuration with a custom-built optofluidic system designed for concomitant controlled vapor delivery and emission measurement, we achieve a limit-of-detection of 100 parts per billion (ppb) for hydrogen peroxide vapor. The PBG fibers are produced by a new fabrication method whereby external gas pressure is used as a control knob to actively tune the transmission bandgaps through the entire visible range during the thermal drawing process.

Relationships between the Nevada brief cognitive assessment instrument and the St. Louis University mental status examination in the assessment of disability applicants.

Mental status examinations of individuals applying for disability are most often authorized as "2-hour" evaluations and are to include a complete clinical and employment history, assessment of neurocognitive functions, an estimate of general level of intelligence, psychological and social adjustment, functional abilities, and a complete multipage report of the results. In the interest of meeting these demands we have been using the Nevada brief cognitive assessment instrument (NBCAI) to rapidly estimate verbal intelligence, and we have adopted the Saint Louis University Mental Status Examination (SLUMS) to investigate neurocognitive functions. Areas of correspondence and differences between these screens are presented along with an explanation of why execution of both screens could be useful in addressing psychological questions concerning disability. The two instruments failed to correlate significantly in a group of patients undergoing pre-surgical evaluation likely because this sample was more highly educated and more homogeneous than the sample of disability referrals. For example, although the ages of the samples were close (disability sample mean and standard deviation age: 43.88 and 11.35 years; pre-surgical sample mean and standard deviation age: 46.14 and 2.84 years), they differed considerably in level of education (disability sample mean and standard deviation: 11.03 and 2.15; pre-surgical mean and standard deviation: 15.22 and 2.84). The pre-surgical group had mean performances close to the ceiling levels of both instruments.

Review of adjunctive glutamate antagonist therapy in the treatment of catatonic syndromes.

Catatonia is a common neuropsychiatric syndrome which may arise from GABA-A hypoactivity, dopamine (D2) hypoactivity,and possibly glutamate NMDA hyperactivity. Amantadine and memantine have been reported as effective treatments for catatonia in selected cases, and probably mediate the presence of catatonic signs and symptoms through complex pathways involving glutamate antagonism. The authors identified 25 cases of catatonia treated with either agent. This article provides indirect evidence that glutamate antagonists may improve catatonic signs in some patients who fail to respond to established treatment, including lorazepam or electroconvulsive therapy. Further study of glutamate antagonists in the treatment of catatonia is needed.

Approaches to the study of higher cognitive functions related to creativity in nonhuman animals.

Fundamental to creativity is prior knowledge and learning capability. One can be creative only to the extent that one's prior knowledge and learning abilities enable. Many of the mental functions of humans that are affected by neuropathology involve levels of learning ability that supercede those used by most animal researchers. Yet there is literature showing that there are similarities in structure and function in the cerebrum within class Mammalia and that nonhuman animals are capable of higher levels of learning than those typically studied by neuroscientists. Reviews of abstracts from the 2005 meeting of the Society for Neuroscience reveal that most neurobehavioral research with animals has involved relatively low levels of learning ability. Thomas's [R.K. Thomas, Brain, Behav. Evol. 17 (1980) 452-474.] hierarchy of learning abilities has been revised here to better include Learning Set Formation which is fundamental to most forms of higher learning. This paper summarizes both the rationale and the methodologies that might be used to assess the roles of neuroanatomical structures involved in the psychological processes that serve as the bases of creativity.

Topiramate attenuates a transient learning deficit after lesions inducing intracerebral hemorrhage.

28 male Long-Evans rats prepared with lesions of the middle cerebral artery displayed deficits in spatial navigational learning in a simple version of the Morris Water Maze task not seen in animals prepared with the same injury but administered 4 treatments with topiramate after surgery.

A new approach to the preionization of flash lamps in power lasers.

As long as neodymium amplifiers will be used in high-energy lasers, preionization problems will be present in firing the flash lamps. It is difficult to find papers describing technical solutions using preionization concept; only a few internal reports and proceedings from Pulsed Power conferences describe the usage of such circuits in power laser facilities. In all of them, a special negative high voltage power supply is used. A new simple solution, without any additional power supply, using only a small part of the energy gathered in the main capacitor bank for generating a preionization pulse is used. The firing order is split into two signals; the first one is triggering preionization circuit and the second one, after delaying, is triggering the main discharging circuit.

Conjugated polymer nanoparticles for biochemical protein kinase assay.

Sensitive and reliable monitoring of kinase activity was reported by using highly efficient fluorescence resonance energy transfer of conjugated polymer nanoparticles (CPNs) to a rhodamine labelled peptide substrate.

Ketamine appears associated with better word recall than etomidate after a course of 6 electroconvulsive therapies.

Ten patients treated with electroconvulsive therapy (ECT) for depressive illness received anesthesia with either etomidate or ketamine. Three patients received both etomidate and ketamine anesthesia for ECT during separate episodes of depression. Patients anesthetized with ketamine for ECT had significantly less impairment of short-term memory function than did patients who received ECT with etomidate anesthesia. All patients who received both anesthetics for ECT during 2 different episodes had less memory loss during ECT with ketamine than with etomidate. These results show the importance of studying the effects of all anesthetic agents used during ECT on cognitive functions. The results imply that the effect of ECT on memory may be largely caused by effects mediated by glutamate at N-methyl-d-aspartate receptors and suggest that N-methyl-d-aspartate antagonists may offer protection from memory dysfunction during ECT.

Topiramate effect in catatonia: a case series.

The authors describe four cases of catatonia in which topiramate treatment was used. Commonly effective therapies, including benzodiazepines and divalproex, were proven refractory. In all four cases, subjects experienced complete remission of catatonic symptoms and tolerated treatment well. In one case, all psychotropic medications were discontinued because the patient became delirious. The delirium resolved after discovery and treatment of a urinary tract infection. Catatonic agitation relapsed when topiramate was withdrawn but remitted again when topiramate and lorazepam therapy was restored. In two cases, continued topiramate therapy was accompanied by sustained remission. These case reports present a novel approach to the treatment of catatonia.

Facile fabrication of poly(p-phenylene ethynylene)/colloidal silica composite for nucleic acid detection.

Fabrication, characterization, and application of poly(phenylene ethynylene) (PPE)/silica composite particles are described. PPE is a class of conjugated polymers, which has been used for various sensory materials. However, its hydrophobic nature makes its application difficult in the aqueous phase, especially for biological substance detection. In this report, we utilized non-aqueous soluble PPE, 15 nm of colloidal silica particles, and aminosilane to fabricate a biosensory platform. The resulting composite showed high aqueous compatibility, large surface area, high quantum efficiency, and versatile chemical modification including oligonucleotide coupling. By monitoring the fluorescence quenching of PPE, we could detect a quencher-labeled target oligonucleotide specifically. Stern-Volmer (SV) analysis showed different accessibility of fluorophores (PPE) to a quencher labeled target oligonucleotide. The accessibility of fluorophores and SV constant are determined to be 0.54 and 4.2 x 10(7)M(-1), respectively, from a modified SV plot. This method will broaden the capability of conjugated polymers for the sensitive detection of biological substances.

Lessons learned from Indonesia: an outline.

The U.S. response to the December 26, 2004 tsunami in Indonesia heralded modifications of our responses to previous natural disasters, modifications that were highly successful and should be refined and repeated. These included seamless hand-off of responsibility from a line response unit to medical; the use of civilian medical practitioners working closely with military and public health service personnel aboard a Navy vessel; close prior communication and planning with the local medical, governmental, and U.N. establishment ashore before the arrival of the military medical unit; and with both line and medical units working closely in support of established ashore U.N. agencies instead of performing independent actions. The success of this total approach was unquestioned, and the lessons learned should be utilized fully in planning future disaster responses, both foreign and domestic.