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PubMed1994

Exploration of anatomical dolls by nonreferred preschool-aged children: comparisons by age, gender, race, and socioeconomic status.

The contributions of age, gender, race, and socioeconomic status (SES) to differences in nonreferred (i.e., presumably nonabused) preschool-aged children's interactions with anatomical dolls were explored. Significant age findings included a decrease with age in manual exploration, an increase in showing doll-to-doll kissing and an increase in demonstrating suggestive intercourse between the dolls. Although 2-year-olds were active in undressing the dolls and exploring the genitals, anus, and breasts, no 2-year-old displayed any sexualized behaviors with the dolls. Six percent (6%) of the children demonstrated clear intercourse positioning. Only low SES black males, ages 4 and 5, demonstrated clear intercourse positioning when the interviewer was present in the room. However, such demonstrations were seen across gender and race and SES when the children were left alone with the dolls. The implications of the findings for evaluators who interview children using anatomical dolls are discussed.

Child Abuse, Sexual↗

PubMed1996

Role of hippocampal 5-HT1A receptors on elevated plus maze exploration after a single restraint experience.

Previous studies have shown that 2 h restraint stress induces deficits in open arm exploration of an elevated plus maze 24 h later. This effect was attenuated by a post-stress systemic injection of the 5-HT non-selective agonist, 5-methoxy-N,N-dimethyltryptamine (5-MeODMT). To verify a possible involvement of hippocampal 5-HT1A receptors in this effect, rats were stereotaxically implanted with canulae in the dorsal hippocampus. Seven days later they received bilateral microinjections of 5-MeODMT (20 nmol/0.5 microliter) or saline. No difference was found on exploration of an elevated plus maze 24 h later. However, when treatments were performed immediately after 2 h of restraint stress, the drug was able to increase open arm exploration 24 h later. This effect was antagonized by a previous microinjection of (+)WAY-100135 (40 nmol/0.5 microliter), a selective 5-HT1A antagonist. The results suggest that hippocampal 5-HT1A receptors may attenuate stress behavioral consequences.

Animals↗

PubMedDate not supplied

Short-term memory, exploration and locomotor activity in aged rats.

Behavioral profiles of young (3-6 months) and aged (24-27 months) rats were compared in three respects: (1) short-term memory, (2) exploration and (3) locomotor activity. Compared to young rats, aged rats were impaired in the 8-arm radial maze acquisition, but not in the delayed reinforced alternation acquisition. They had lower scores of spontaneous alternation, of exploration of a novel object and of a novel environment. Their exploratory activity was lower in a simple environment but similar in a complex environment. Their spontaneous locomotor activity was lower during the dark part of the cycle (8 p.m.-8 a.m.) but not different during the light part of the cycle (8 a.m.-8 p.m.). These results suggest that with respect to short-term memory and exploration, differences between aged and young rats may be influenced by a "complexity" factor and may be secondary to differences in motivation and reactions to novelty.

Aging↗

PubMed1994

Rapid exploration of alternatives via chaos.

Temporary chaos facilitates a rapid exploration of alternative asymptotic possibilities. The phenomenon of alternative-exploration via chaos is shown to have a finite probability of occurrence for a class of dynamical systems, the evolution of which is described by (complex) analytic maps. The ability to explore alternatives confers an adaptive advantage, and the possible relevance of temporary chaos to rapid mutations is discussed.

Adaptation, Biological↗

PubMedDate not supplied

Lunar precursor missions for human exploration of Mars--III: studies of system reliability and maintenance.

Discussions of future human expeditions into the solar system generally focus on whether the next explorers ought to go to the Moon or to Mars. The only mission scenario developed in any detail within NASA is an expedition to Mars with a 500-day stay at the surface. The technological capabilities and the operational experience base required for such a mission do not now exist nor has any self-consistent program plan been proposed to acquire them. In particular, the lack of an Abort-to-Earth capability implies that critical mission systems must perform reliably for 3 years or must be maintainable and repairable by the crew. As has been previously argued, a well-planned program of human exploration of the Moon would provide a context within which to develop the appropriate technologies because a lunar expedition incorporates many of the operational elements of a Mars expedition. Initial lunar expeditions can be carried out at scales consistent with the current experience base but can be expanded in any or all operational phases to produce an experience base necessary to successfully and safely conduct human exploration of Mars.

Astronauts↗

PubMedDate not supplied

Lunar exploration and development--a sustainable model.

A long-term goal of space exploration is the development of a lunar settlement that will not only be largely self-sufficient but also contribute to the economy of the Earth-Moon system. Proposals for lunar mining and materials processing developments, as well as tourism-based applications, have appeared in the literature for many years. However, so great are the technical and financial difficulties associated with sustained lunar development that, more than 30 years after the end of the Apollo programme, there have been no practical advances towards this goal. While this may soon be remedied by a series of proposed unmanned orbiters, landers and rovers, the philosophy of lunar exploration and development remains the same as it has for decades: conquer, exploit, and ignore the consequences. By contrasting the well-recognised problems of Earth orbital debris and the barely recognised issue of intentional spacecraft impacts on the lunar surface, this paper illustrates the need for a new model for lunar exploration and development. This new paradigm would assign a value to the lunar environment and provide a balance between protection and exploitation, creating, in effect, a philosophy of sustainable development for the Moon. It is suggested that this new philosophy should be an integral part of any future strategy for lunar colonisation.

Containment of Biohazards↗

PubMed2004

Prospective evaluation of ultrasonography plus MIBI scintigraphy in selecting patients with primary hyperparathyroidism for unilateral neck exploration under local anaesthesia.

BACKGROUND: Unilateral neck exploration (UNE) is currently replacing conventional bilateral neck exploration with cervicotomy for the surgical treatment of primary hyperparathyroidism (PHPT). However, many concerns still exist about the indications and the effectiveness of this minimally invasive approach. METHODS: Prospective evaluation of operative results in consecutive patients having indications for UNE on the basis of strict selection criteria consisting of ultrasound-MIBI agreement in adenoma localization, absence of thyroid disease, and psychological suitability for undergoing a procedure under local anesthesia. No intraoperative confirmation study was adopted. RESULTS: Among 149 consecutive PHPT patients, 45 (30.2%) had indications for UNE. No operative morbidity or mortality was observed. Mean operative time for the UNE procedure was 42 minutes (range 25 to 57). Conversion to general anesthesia was chosen for 5 patients (11.1%), whereas conversion to bilateral neck exploration was chosen for 3 patients (6.6%). For the UNE procedure, the success rate was as high as 91.7%. When the only factor indicated UNE, ultrasound-MIBI localization agreement had low sensibility (44.1%) and specificity (55.6%) but a high positive predictive value (91.1%). CONCLUSIONS: We concluded that UNE performed under local anesthesia, without intraoperative confirmation studies, could be considered a safe and effective approach to treating patients with PHPT, but we regret the low rate of patients selected for this procedure because of the low sensitivity of the imaging-inclusion criterion.

Adult↗

PubMed2005

Exploring parental grief: combining quantitative and qualitative measures.

PURPOSE: This study explores parental grief on the death of a child of any age. STUDY DESIGN: The sampling frame for the study consisted of 74 respondents reporting that they experienced the death of a living child. With the exception of standard demographic measures, the quantitative and qualitative items in the instrument were designed specifically for this project. The content validity of the instrument was assessed by a panel of experts on grief. Key quantitative items related to child loss and grief were formatted with between three- and five-point ordinal answer categories. Two types of qualitative items were developed by the authors. The reliability of the instrument designed for this study was not determined. RESULTS: This survey of parents who experienced the death of a child during their lifetime explores and extends current understanding of the complex emotional response of grief. The study offers empirical support for the notion of grief as ongoing in the life of a parent whose child had died. The findings have significant implications for further clinical research supporting studies to explore commonalities in the experience of grieving families regardless of the cause of and time since the death of their child. In addition, the findings may serve to inform the development and provision of services for bereaved parents.

Adaptation, Psychological↗

PubMed2005

Effect of Y1 receptor deficiency on motor activity, exploration, and anxiety.

Neuropeptide Y (NPY) in the CNS plays an important regulatory role in anxiety-related responses as exogenous administration of NPY exerts an anxiolytic-like effect in rodents. This effect is believed to be mediated by the Y(1) receptor system as pharmacological modulation of this Y(1) receptor system results in an increase in anxiety. Here we present a comprehensive phenotyping strategy for characterizing Y(1) receptor knockout animals at different times of the circadian rhythm using several motor activity-, exploration-, and anxiety-related behavioural tasks including open field, elevated plus maze, light-dark, and hole board test. We show that Y(1) deficiency has an important effect on motor activity and explorative-like behaviours and that it results in marked alterations in anxiety-related behaviours. Importantly, the behavioural phenotype of the Y(1) receptor knockout mice is circadian rhythm-dependent and also influenced by stimuli such as restraint stress. In addition, we found evidence for increases in working memory. Taken together, these findings suggest an important role of Y(1) receptors in the regulation of motor activity, exploration, and anxiety-related behaviours. This role is also influenced by several factors such as circadian rhythm and stress exposure confirming the importance of a comprehensive strategy and of using genetic animal models in behavioural neuroscience.

Analysis of Variance↗

PubMed2006

Exploration in a dark open field: a shift from directional to positional progression and a proposed model of acquiring spatial information.

Exploration in a dark open field undergoes three progressive changes: (i) an initial phase of spending equal amounts of time in various zones of the arena changes to staying in the corners, and ultimately spending most of the time in one corner; (ii) travel paths are first circular and scattered all over the arena, but gradually become anchored to one corner at which they start and end; (iii) traveled distance gradually decreases to that of the initial level seen in a lit open field. Altogether, rodents shift from a 'looping' exploration mechanism with feeble coupling with the environment, to 'home base' exploration which is firmly anchored to the environment. This shift also involves switching from momentary and sporadic to repeated returns to a specific, presumably familiar place, to which the animal navigates back from various other places. We suggest that this switching illustrates navigation first by directional and then by positional environmental cues, as hypothesized in the 'parallel map theory'. We also suggest that the transition from looping to home base behavior is part of a hierarchal construction of space representation via three modes of spatial information processing: (i) piloting--sequential processing, based on moving from one landmark to the next; (ii) orienting--parallel processing, based on moving from one point to the next, with the same starting and ending point; (iii) navigating--continuous processing, based on continuously updating the position in relation to several locations in the environment (map navigation).

Analysis of Variance↗

PubMed2006

Behavioral neuroscience, exploration, and K.C. Montgomery's legacy.

Exploration is a key animal and human behavior. Kay C. Montgomery (1921-1956) has made an important contribution to behavioral neuroscience of exploration, as well as motivation and learning. His works have many important applications to current experimental models of stress, fear and memory, continuing to influence research in this field. This paper, dedicated to the 85th anniversary of Montgomery's birth, and 50 years since his tragic death, summarizes Montgomery's contribution to behavioral neuroscience, and discusses its current importance for further progress in this field. It is aimed at neuroscientists with strong interests in both theory of animal exploration and motivation, and the history of behavioral neuroscience.

Adult↗

PubMed2004

Anticipatory spatial representation of 3D regions explored by sighted observers and a deaf-and-blind-observer.

Viewers who study photographs of scenes tend to remember having seen beyond the boundaries of the view [boundary extension; J. Exp. Psychol. Learn. Mem. Cogn. 15 (1989) 179]. Is this a fundamental aspect of scene representation? Forty undergraduates explored bounded regions of six common (3D) scenes, visually or haptically (while blindfolded) and then the delimiting borders were removed. Minutes later they reconstructed boundary placement. Boundary extension occurred: mean areas were increased by 53% (vision) and by 17% (haptics). A deaf-and-blind woman (KC) haptically explored the same regions. Although a "haptic expert", she too remembered having explored beyond the boundaries, with performance similar to that of the blindfolded-sighted. Boundary extension appears to be a fundamental aspect of spatial cognition. Possibly constrained by the "scope" of the input modality (vision>haptics), this anticipatory spatial representation may facilitate integration of successively perceived regions of the world irrespective of modality and the perceiver's sensory history.

Adult↗

PubMed2004

Fighting the 'microbe of sporting mania': Australian science and Antarctic exploration in the early 20th century.

The 'Heroic Age' of Antarctic exploration, which occurred during the first 15 years of the 20th century, captured headlines around the world. Australia was no exception, especially as Australian scientists played important roles in several expeditions. Through participation in the British Antarctic Expedition of 1907-1909, two Australian scientists - T.W. Edgeworth David (1858-1934) and Douglas Mawson (1882-1958) - became genuine national heroes, mainly through being members of the first party to reach the South Magnetic Pole area. At a superficial level, the vehicle of Antarctic exploration placed science at the forefront of public awareness, fulfilling David's ambition for greater recognition of science and scientists, especially considering the high level of public interest in sport. However, although David and Mawson gave Antarctic exploration a scientific veneer, simply through their status as scientists, the public viewed them as heroes because they had endured great hardships and conquered a point on the map in the name of science and the Empire.

Antarctic Regions↗

PubMed2006

Transcolonic endoscopic abdominal exploration: a NOTES survival study in a porcine model.

BACKGROUND: Published reports on NOTES (natural orifice transluminal endoscopic surgery) have thus far been limited to the transgastric method. OBJECTIVE: The aim of this study was to assess the transcolonic approach as a means of accessing and systematically exploring the abdominal cavity in a survival study design. DESIGN: Six pigs were placed under general anesthesia and were prepped with multiple tap-water enemas, followed by instillation of a cefazolin suspension and a povidone-iodine lavage. Equipment was prepared with a high-level chemical disinfection, and an aseptic technique was used. An incision was made in the anterior colonic wall, and abdominal exploration was performed by using a double-channel endoscope. The incision was subsequently closed with endoscopic clips, endoloops, or a prototype closure device. PATIENTS: Six female Yorkshire pigs that weighed 25 to 30 kg. RESULTS: Stomach, liver, gallbladder, spleen, small bowel, colon, and peritoneal surfaces were identified in all animals in less than 3 minutes. The lower pelvic organs were not consistently visualized. All animals were alive for 14 days without apparent complications. At necropsy, the colonic incision sites were completely closed and appeared well healed. Microscopic inflammatory changes were seen at the closure site in all animals, including microabscesses. Incision-related adhesions were identified in 4 of 6 animals. CONCLUSIONS: This study demonstrated the use of a novel transcolonic approach to successfully access and explore the abdominal cavity. In contrast to the transgastric method, a transcolonic approach provides more consistent identification of structures in the upper abdomen and provides better en face orientation and scope stability. Therapeutic interventions in the upper abdomen, including organ resection, may be more tenable by using a transcolonic method; however, further studies are needed to address issues of sterility and colonic closure.

Animals↗

PubMed2005

Interactively exploring optimized treatment plans.

PURPOSE: A new paradigm for treatment planning is proposed that embodies the concept of interactively exploring the space of optimized plans. In this approach, treatment planning ignores the details of individual plans and instead presents the physician with clinical summaries of sets of solutions to well-defined clinical goals in which every solution has been optimized in advance by computer algorithms. METHODS AND MATERIALS: Before interactive planning, sets of optimized plans are created for a variety of treatment delivery options and critical structure dose-volume constraints. Then, the dose-volume parameters of the optimized plans are fit to linear functions. These linear functions are used to show in real time how the target dose-volume histogram (DVH) changes as the DVHs of the critical structures are changed interactively. A bitmap of the space of optimized plans is used to restrict the feasible solutions. The physician selects the critical structure dose-volume constraints that give the desired dose to the planning target volume (PTV) and then those constraints are used to create the corresponding optimized plan. RESULTS: The method is demonstrated using prototype software, Treatment Plan Explorer (TPEx), and a clinical example of a patient with a tumor in the right lung. For this example, the delivery options included 4 open beams, 12 open beams, 4 wedged beams, and 12 wedged beams. Beam directions and relative weights were optimized for a range of critical structure dose-volume constraints for the lungs and esophagus. Cord dose was restricted to 45 Gy. Using the interactive interface, the physician explored how the tumor dose changed as critical structure dose-volume constraints were tightened or relaxed and selected the best compromise for each delivery option. The corresponding treatment plans were calculated and compared with the linear parameterization presented to the physician in TPEx. The linear fits were best for the maximum PTV dose and worst for the minimum PTV dose. Based on the root-mean-square error between the fit values and their corresponding data values, the linear fit appears to be adequate, although higher order polynomials could give better results. Some of the variance in fit is due to the stochastic nature of the simulated annealing optimization algorithm, which does not reproduce the exact same results in repetitions of the same calculation. Using a directed search algorithm for plan optimization should produce better parameter fits and, therefore, better predictions of plan characteristics by TPEx. CONCLUSIONS: Using TPEx, the physician can easily select the optimum plan for a patient, with no imposed arbitrary definition of the "best" plan. More importantly, the physician can readily see what can be achieved for the patient with a given delivery technique. There is no more uncertainty about whether or not a better plan exists. By comparing the "best" plans for different delivery options (e.g., three-dimensional conformal radiotherapy versus intensity-modulated radiation therapy), the physician can gauge the clinical benefits of greater technical complexity. However, before the TPEx process can be clinical useful, faster computers and/or algorithms are needed and more studies are needed to better model the spaces of optimized solutions.

Algorithms↗

PubMed2005

Novel strategy for protein exploration: high-throughput screening assisted with fuzzy neural network.

To engineer proteins with desirable characteristics from a naturally occurring protein, high-throughput screening (HTS) combined with directed evolutional approach is the essential technology. However, most HTS techniques are simple positive screenings. The information obtained from the positive candidates is used only as results but rarely as clues for understanding the structural rules, which may explain the protein activity. In here, we have attempted to establish a novel strategy for exploring functional proteins associated with computational analysis. As a model case, we explored lipases with inverted enantioselectivity for a substrate p-nitrophenyl 3-phenylbutyrate from the wild-type lipase of Burkhorderia cepacia KWI-56, which is originally selective for (S)-configuration of the substrate. Data from our previous work on (R)-enantioselective lipase screening were applied to fuzzy neural network (FNN), bioinformatic algorithm, to extract guidelines for screening and engineering processes to be followed. FNN has an advantageous feature of extracting hidden rules that lie between sequences of variants and their enzyme activity to gain high prediction accuracy. Without any prior knowledge, FNN predicted a rule indicating that "size at position L167," among four positions (L17, F119, L167, and L266) in the substrate binding core region, is the most influential factor for obtaining lipase with inverted (R)-enantioselectivity. Based on the guidelines obtained, newly engineered novel variants, which were not found in the actual screening, were experimentally proven to gain high (R)-enantioselectivity by engineering the size at position L167. We also designed and assayed two novel variants, namely FIGV (L17F, F119I, L167G, and L266V) and FFGI (L17F, L167G, and L266I), which were compatible with the guideline obtained from FNN analysis, and confirmed that these designed lipases could acquire high inverted enantioselectivity. The results have shown that with the aid of bioinformatic analysis, high-throughput screening can expand its potential for exploring vast combinatorial sequence spaces of proteins.

Fuzzy Logic↗

PubMed2004

Surgical exploration of the mediastinum: mediastinoscopy and intraoperative staging.

Lung resection remains the therapy of choice offering the greatest potential for cure in non-spread lung cancer. Prognostic importance of lymph-node involvement has been underlined by several studies. So, exploration of the mediastinum is of major importance for defining the therapeutic strategy in a possibly curative setting. Pre-resectional exploration of the mediastinal lymph-nodal status is mandatory to define tumour stage exactly and establish specific therapy. Cervical mediastinoscopy is the primary diagnostic procedure and remains the gold standard in invasive surgical staging. Complementary, parasternal mediastinoscopy, extended mediastinoscopy, and video-assisted thoracoscopy may be performed. These techniques allow accurate assessment of mediastinal lymph-node involvement, resulting in an appropriate judgement as to resectability and possible treatment options. Different techniques are established for intraoperative exploration and staging. In terms of curative surgery of lung cancer we demand accurate staging which is achieved by systematic and complete Lymph-node dissection. So, individually and dependent on primary tumour site, accurate mediastinal staging of Lung cancer should be performed in combination with definitive lung resection.

Humans↗

PubMed2004

Joint explorative analysis of neuroreceptor subsystems in the human brain: application to receptor-transporter correlation using PET data.

Positron emission tomography (PET) has proved to be a highly successful technique in the qualitative and quantitative exploration of the human brain's neurotransmitter-receptor systems. In recent years, the number of PET radioligands, targeted to different neuroreceptor systems of the human brain, has increased considerably. This development paves the way for a simultaneous analysis of different receptor systems and subsystems in the same individual. The detailed exploration of the versatility of neuroreceptor systems requires novel technical approaches, capable of operating on huge parametric image datasets. An initial step of such explorative data processing and analysis should be the development of novel exploratory data-mining tools to gain insight into the "structure" of complex multi-individual, multi-receptor data sets. For practical reasons, a possible and feasible starting point of multi-receptor research can be the analysis of the pre- and post-synaptic binding sites of the same neurotransmitter. In the present study, we propose an unsupervised, unbiased data-mining tool for this task and demonstrate its usefulness by using quantitative receptor maps, obtained with positron emission tomography, from five healthy subjects on (pre-synaptic) serotonin transporters (5-HTT or SERT) and (post-synaptic) 5-HT(1A) receptors. Major components of the proposed technique include the projection of the input receptor maps to a feature space, the quasi-clustering and classification of projected data (neighbourhood formation), trans-individual analysis of neighbourhood properties (trajectory analysis), and the back-projection of the results of trajectory analysis to normal space (creation of multi-receptor maps). The resulting multi-receptor maps suggest that complex relationships and tendencies in the relationship between pre- and post-synaptic transporter-receptor systems can be revealed and classified by using this method. As an example, we demonstrate the regional correlation of the serotonin transporter-receptor systems. These parameter-specific multi-receptor maps can usefully guide the researchers in their endeavour to formulate models of multi-receptor interactions and changes in the human brain.

Adult↗