Light field reconstruction with randomly shot photographs.

Light field imaging is a promising technique for recording and displaying three-dimensional (3D) scenes. Light field reconstruction using a conventional camera, instead of a lens-array-based plenoptic camera, is expected to have a higher resolution. However, in existing conventional-camera-based methods, the camera placement is restricted. In this paper, we propose a new flexible light field reconstruction method involving shooting using a conventional camera from random 3D positions and angles. The proposed method has the advantage of flexibility because it uses a conventional camera, and the shooting position and angle can be selected randomly. Such flexibility is expected to give it a wide range of applications.

Investigating toxicity specific to adjuvanted vaccines.

In an attempt to understand the unique toxicity of adjuvanted vaccines, we studied how toxicity develops over time following vaccine administration. In addition to on- and off-target toxicity typically observed with general pharmaceuticals, we observed toxicity associated with both the generation and the broad action of effectors (antibodies and/or cytotoxic T lymphocytes, CTLs). The impact on effector generation appears to be related to local tolerance specific to the adjuvant. The vaccine immune response by effectors serves to demonstrate species relevance as outlined in the recent WHO guideline on the nonclinical evaluation of adjuvanted vaccines. When regarded as pharmaceuticals that function at sites of local administration, adjuvants have inherent on- and off-target toxicity. On-target toxicity of the adjuvant is typically associated with effector generation, and could vary depending on animal species. Therefore, the use of species with sensitivity to adjuvants described in the WHO guidelines is required to evaluate the toxicity of the vaccine associated with effector generation. Changes in safety pharmacology endpoints would be considered off-target and further studies are conducted only if changes in these endpoints are observed in nonclinical or clinical studies. Thus our decision tree does not recommend the routine conduct of stand-alone safety pharmacology studies.

Long-term radiographic evaluation of risk factors related to implant treatment: suggestion for alternative statistical analysis of marginal bone loss.

OBJECTIVE: Secular change in marginal bone loss (MBL), which is the index adopted for implant success criteria, has often been used to evaluate risk factors. However, the need to revise these criteria has recently been indicated due to rapid developments in implant treatment. The purpose of this study was to evaluate risk factors by analyzing MBL with an alternative statistical method. MATERIAL AND METHODS: The analyses were performed on the outcomes of 366 patients with 1,902 implants during an average follow-up period of 84.8 months (with a maximum follow-up of 258 months). Instead of evaluating annual MBL, time was calculated as one of the explanatory variables because the correlation between MBL and time was small (correlation coefficient of 0.09010). Analysis of covariance (ANCOVA) was used for exploratory assessment of each factor, and multiple regression analysis was then utilized to identify risk factors. The multiple regression analysis was performed twice, once among all implants and another in which one implant per patient was randomly selected. RESULTS: As a result of multiple regression analysis, smoking habits showed a significant effect on MBL. Age, sex, diabetes mellitus, implant positions, guided bone regeneration, and sinus floor elevation did not affect MBL. IMZ® implants were associated with significantly higher MBL than were ANKYLOS® and SPI® implants. There was no significant difference between Straumann® and other implants. CONCLUSION: Our results showed that another statistical process, which eliminated the effect of time rather than comparing annual MBL, could be applied to evaluate MBL because the correlation between MBL and time was small.

Case presentation of two patients using diagonal platform-switched double implants for maxillary single-first-molar replacement as the alternative of a single-tooth implant.

A single-tooth implant restoration is generally performed for maxillary single-first-molar replacement. If the interdental space between the second premolar and the second molar is large enough, a double-implant placement can be performed to avoid creating mesiodistal cantilever and to distribute occlusal loading forces.If there is not adequate space for a double-implant placement to be performed mesiodistally along the crest of the alveolar ridge line, they should be placed along a diagonal line offset lingually to increase the space. This procedure has two primary advantages. First, greater stability is provided by a double-implant placement. Resistance to lateral forces (palatal-buccal) is much stronger than two implants placed along the alveolar crest ridge line. Residual palatal and buccal bone can provide support against occlusal forces, provided that there is adequate residual bone in these regions.If anatomical conditions are favorable, the placement of two diagonal implants in the palatal and buccal residual bones can be a rational procedure.We report on two typical patients. The progress of these patients was followed using computed tomography for 7 and 6 years, respectively.

Considerations for non-clinical safety studies of therapeutic peptide vaccines.

Guidelines for non-clinical studies of prophylactic vaccines against infectious diseases have been published widely, but similar guidelines for therapeutic vaccines, and especially therapeutic peptide vaccines, have yet to be established. The approach to non-clinical safety studies required for therapeutic vaccines differs from that for prophylactic vaccines due to differences in the risk-benefit balance and the mechanisms of action. We propose the following guidelines for non-clinical safety studies for therapeutic peptide vaccines. (i) Since the main safety concern is related to the immune response that might occur at normal sites that express a target antigen, identification of these possible target sites using in silico human expression data is important. (ii) Due to the strong dependence on HLA, it is not feasible to replicate immune responses in animals. Thus, the required non-clinical safety studies are characterized as those detecting off-target toxicity rather than on-target toxicity.

Remembering and forgetting: directed forgetting effect in obsessive-compulsive disorder.

It has been reported that episodic memory seems to be impaired in patients with obsessive-compulsive disorder (OCD) because the patients repeat a specific checking behavior, but it is still unknown if OCD patients show memory impairments associated with their unique symptoms or not. To study episodic memory in OCD patients, we examined the directed forgetting effect. Patients with OCD and healthy control participants were given a list of 24 emotionally neutral everyday words (12 remember [R]-cued words and 12 forget [F]-cued words) under two conditions: List and Item. The results of our study showed that OCD patients recalled a number of F-cued words similar to that for controls and relatively fewer R-cued words than controls under both List and Item conditions. Consequently, the directed forgetting effect was smaller in OCD patients than controls. Our results demonstrated that both selective encoding and retrieval inhibition processes are impaired in OCD, and we suggest that recall of unfavorable items to be forgotten intruded into necessary items to be remembered. This impairment in episodic memory may partially account for some of the unique clinical symptoms of OCD.

Factors of error and effort in memory intervention for patients with Alzheimer's disease and amnesic syndrome.

BACKGROUND: Factors of error and effort in study conditions play a crucial role in the intervention for memory-impaired individuals. In the present study, efficacy of four study conditions was compared in order to elucidate the optimal study conditions: errorless/errorful and effortless/effortful. METHODS: A total of 18 patients with Alzheimer's disease and 12 patients with amnesic syndrome received study-test sessions under four different study conditions: errorless/errorful and effortless/effortful. RESULTS: The errorless learning advantage was confirmed for both Alzheimer's disease and amnesic syndrome on both free recall and cued recall tests. In contrast, effortful learning was effective only for amnesic syndrome on a free recall test. CONCLUSION: Despite the overall advantage of errorless learning, the effortful process was effective in circumscribed situations.

The predictivity of preliminary embryo-fetal development (EFD) studies: results of a retrospective survey in Japanese pharmaceutical companies.

To explore the predictivity of dose range-finding (DRF) studies, we conducted asurvey by sending out questionnaires to 72 Japanese pharmaceutical companies.The survey yielded data for 108 and 85 compounds for which any embryo-fetaldevelopment (EFD) toxicities were observed in the definitive studies in rodentsand non-rodents, respectively. As a result of the analysis, 83% of studies inrodents and 80% in non-rodents showed EFD effects in the DRF studies. Whenfocusing on teratogenicity, 91% of studies in rodents and 100% in non-rodentswere judged "positive" in the DRF studies when all EFD toxicities were used asmarkers. When the effects of both the rodent and non-rodent studies wereevaluated together, the combination predictive value in the DRF studies was 96%for EFD toxicants and 100% for teratogens. To evaluate the influence of theexamination items, the predictive value was analyzed using 54 compounds forwhich full examinations (external, visceral and skeletal examination) wereconducted in both rodent and non-rodent DRF studies. When the results werejudged by including or excluding skeletal and visceral examinations results,the predictive values were not significantly different. In conclusion, theresults of this survey showed that a pair of the DRF studies in the rodents andnon-rodents is useful to increase the predictivity of DRF studies. In additionthe inclusion of observations such as fetal survival, body weight and externalexamination into the DRF studies are important to predict effects in thedefinitive studies.

Collaborative work on evaluation of ovarian toxicity by repeated-dose and fertility studies in female rats.

The National Institute of Health Sciences (NIHS) and 18 pharmaceutical companies of the Japan Pharmaceutical Manufacturers Association (JPMA) have conducted a validation study intended to evaluate whether a 2-week repeated general toxicity period with histopathological examination is sufficient to detect ovarian toxicity or not. The current repeated dose general toxicity study is considered to be insufficient in terms of evaluating female reproductive function due to a lack of evidence indicating that it is adequate. Evaluation of ovarian toxicity by comprehensive histopathological examination of the female reproductive organs based on the underlying morphology of a normal cycle of the reproductive tract including the ovary and additional immunohistochemical staining with proliferative cell nuclear antigen (PCNA) to identify small follicles may be a good tool to assess female reproductive function. In the collaborative study, 2- or 4-week repeated dose toxicity studies with ovarian histopathological examinations were conducted. A female fertility study was also conducted to compare the results with those of the ovarian histopathological findings. A total of 17 test substances were evaluated and categorized into hormone analogues, primordial follicle damaging agents, metabolite imbalance inducers, and endocrine imbalance inducers. Based on the results, ovarian toxicity could be detected by a careful histopatholgical examination. A 2-week dosing period may be sufficient for the evaluation of ovarian toxicity, except for cytotoxic compounds such as alkylating agents. The pathological findings of ovarian toxicity (decreases in follicles, increases in atretic follicles, increases in currently formed corpora lutea, etc) reflected the female fertility parameters (irregular estrous cycle, pre-implantation loss).

Optimized free-form phase mask for extension of depth of field in wavefront-coded imaging.

To achieve a further extension of the depth of field in wavefront-coded imaging by reducing the impact of focus error in the optical transfer function, we propose the use of a free-form phase mask (FPM) instead of a conventional cubic phase mask (CPM). We optimized the shape of the FPM using the simulated annealing algorithm and confirmed that the optimized FPM provides a much larger focal tolerance and better final images than the CPM in the noise-free case.

Message encoding and decoding using an asynchronous chaotic laser diode transmitter-receiver array.

We have numerically investigated a chaotic laser diode transmitter-receiver array scheme (CLDTRAS), which is a secure digital communication scheme using a difference between two types of transmitter-receiver array consisting of two self-pulsating laser diodes (LDs), i.e., a receiver LD and a transmitter LD. By analyzing the bit error rate, particularly its dependence on the parameter mismatches of the hardware and channel noise and on the correlation coefficient between a transmitter LD and receiver LD, we examined the problems of sensitivity to parameter mismatches and channel noise and a dependence on chaos synchronization between a transmitter LD and a receiver LD. The former makes communication difficult, and the latter makes it possible for an eavesdropper to estimate the receiver LD using chaos synchronization and to forge the hardware. Then we studied the effects of the bit error rate for various values of the threshold, which determines a binary message, and for various numbers of transmitters-receivers making up a LD transmitter-receiver array. It has been shown that a highly noise-tolerant and hardware-dependent communication scheme can be achieved with the LD transmitter-receiver array, whose transmitter and receiver LDs are asynchronous with respect to each other, by choosing the proper threshold and increasing the number of LD transmitters-receivers. Since it is possible to communicate without chaos synchronization, it becomes difficult to forge hardware and to eavesdrop with the forged hardware even if the key is stolen.

Further evidence for a comparable memory advantage of self-performed tasks in Korsakoff's syndrome and nonamnesic control subjects.

Two experiments were carried out to examine memory in persons with amnesia using self-performed tasks. In Experiment 1, persons with Korsakoff's syndrome and nonamnesic participants with alcoholism learned action phrases not involving real objects by either self-performed tasks or verbal tasks. As indexed by free recall and recognition tests, a memory advantage favoring self-performed tasks was confirmed in both participant groups. In Experiment 2, persons with Korsakoff's syndrome, nonamnesic alcoholic participants, and young control participants learned object names under three different study conditions that differed from one another as to whether actions for each name were verbally generated and whether actions actually were performed. Verbal generation with or without performing the action facilitated recognition, whereas recall advantage was found only in the verbal generation-plus performance condition. These findings confirm a comparable memory advantage of self-performed tasks for a group with Korsakoff's syndrome and a group of nonamnesic comparison participants. Action memory therefore has potential therapeutic implications for memory rehabilitation.

Cross-script and within-script priming in alcoholic Korsakoff patients.

In two experiments, alcoholic Korsakoff patients and control subjects studied a list of Japanese nouns written in either Hiragana or Kanji script. Word-fragment completion and recognition tests were then administered in Hiragana. When the writing script was changed between study and test phases, repetition priming in word-fragment completion was significantly attenuated but was still reliable against baseline performance. This was confirmed for both Korsakoff patients and control subjects. In contrast, the script change had little effect on recognition memory, which was severely impaired in Korsakoff patients. The results suggest that repetition priming is mediated by two different implicit processes, one that is script-specific and the other that is assumed to operate at a more abstract level.