Do we need STRFs for cocktail parties? On the relevance of physiologically motivated features for human speech perception derived from automatic speech recognition.

Complex auditory features such as spectro-temporal receptive fields (STRFs) derived from the cortical auditory neurons appear to be advantageous in sound processing. However, their physiological and functional relevance is still unclear. To assess the utility of such feature processing for speech reception in noise, automatic speech recognition (ASR) performance using feature sets obtained from physiological and/or psychoacoustical data and models is compared to human performance. Time-frequency representations with a nonlinear compression are compared with standard features such as mel-scaled spectrograms. Both alternatives serve as an input to model estimators that infer spectro-temporal filters (and subsequent nonlinearity) from physiological measurements in auditory brain areas of zebra finches. Alternatively, a filter bank of 2-dimensional Gabor functions is employed, which covers a wide range of modulation frequencies in the time and frequency domain. The results indicate a clear increase in ASR robustness using complex features (modeled by Gabor functions), while the benefit from physiologically derived STRFs is limited. In all cases, the use of power-normalized spectral representations increases performance, indicating that substantial dynamic compression is advantageous for level-independent pattern recognition. The methods employed may help physiologists to look for more relevant STRFs and to better understand specific differences in estimated STRFs.

Empirical and theoretical challenges in aboveground-belowground ecology.

A growing body of evidence shows that aboveground and belowground communities and processes are intrinsically linked, and that feedbacks between these subsystems have important implications for community structure and ecosystem functioning. Almost all studies on this topic have been carried out from an empirical perspective and in specific ecological settings or contexts. Belowground interactions operate at different spatial and temporal scales. Due to the relatively low mobility and high survival of organisms in the soil, plants have longer lasting legacy effects belowground than aboveground. Our current challenge is to understand how aboveground-belowground biotic interactions operate across spatial and temporal scales, and how they depend on, as well as influence, the abiotic environment. Because empirical capacities are too limited to explore all possible combinations of interactions and environmental settings, we explore where and how they can be supported by theoretical approaches to develop testable predictions and to generalise empirical results. We review four key areas where a combined aboveground-belowground approach offers perspectives for enhancing ecological understanding, namely succession, agro-ecosystems, biological invasions and global change impacts on ecosystems. In plant succession, differences in scales between aboveground and belowground biota, as well as between species interactions and ecosystem processes, have important implications for the rate and direction of community change. Aboveground as well as belowground interactions either enhance or reduce rates of plant species replacement. Moreover, the outcomes of the interactions depend on abiotic conditions and plant life history characteristics, which may vary with successional position. We exemplify where translation of the current conceptual succession models into more predictive models can help targeting empirical studies and generalising their results. Then, we discuss how understanding succession may help to enhance managing arable crops, grasslands and invasive plants, as well as provide insights into the effects of global change on community re-organisation and ecosystem processes.

Effects of prosthetic treatment for shortened dental arches on oral health-related quality of life, self-reports of pain and jaw disability: results from the pilot-phase of a randomized multicentre trial.

A multi-centre randomized clinical trial is under way at 14 university dental schools in Germany to compare prosthodontic treatments for the shortened dental arch (SDA). One of the aims of this pilot-study was to measure the effect of two treatment options of the SDA on oral health-related quality of life and on the Research Diagnostic Criteria (RDC) for temporomandibular disorders (TMD). Thirty-four patients participated in the pilot-study. Inclusion criteria were: all molars were missing and the presence of at least both canines and one premolar in each quadrant. Participants were randomly assigned to receive either removable partial dentures including molar replacement (RPD_group) or retain a premolar occlusion (PROC_group). The Oral Health Impact Profile (OHIP-49) and the RDC for TMD were completed by participants before treatment (pre-treatment), 6 weeks (6 wks), 6 months (6m) and 12 months (12 m) after treatment. At the 12-month follow up, data of 10 women and 11 men (mean age: 62 +/- 10 years) were available. Medians of the OHIP total-scores were as follows: RPD (n = 10), 43.5 (pre-treatment), 18.2 (6 wks), 13.3 (6m), 14.7 (12 m). PROC (n = 11): 31.8 (pre-treatment), 27.1 (6 wks), 8.8 (6m), 8.3 (12 m). Significant differences were shown for RPD_group between pre-treatment and 6m/12 m and for PROC_group between pre-treatment and 6m. There were no significant differences between treatment groups at any time. Within each group, an improvement of life-quality was observed. No significant difference could be reported between the two therapy concepts. This may be due to the low sample size within the pilot study.

Austrian report on longitudinal outcome in phenylketonuria.

Forty years after Horst Bickel first treated a patient suffering from phenylketonuria (PKU) our aim is to assess the current treatment of Austrian patients. A total of 70 children -60 with PKU and 10 with hyperphenylalaninaemia (HPA)-aged 6-16 years were investigated in terms of somatic and intellectual parameters. Their development is normal (PKU: mean IQ = 95.40; HPA: mean IQ = 101.85) owing to strict dietary control, above all during their first 6 years of life. A comparison of the IQ data of 17 PKU children and their healthy siblings at the age 6 years showed significant correlations in verbal, performance and IQ measurements. Austrian PKU patients do achieve normal IQ values but these measurements fail to guarantee the quality of dietary control. IQ is influenced by a number of variables: genetic, social environment, education and furtherance, motivation for performance, etc., and, in PKU patients, dietary control. The only currently known way of maintaining and improving dietary compliance in PKU patients and their families remains good informative counselling about the disease and psychosocial support.

The plant metabolite 6-methoxybenzoxazolinone interacts with follicle-stimulating hormone to enhance ovarian growth.

6-Methoxybenzoxazolinone (6-MBOA) is a novel plant metabolite that enhances reproductive status in vertebrate consumers while it inhibits insect, fungal, and bacterial infestation of the plant. Ovaries of prepubertal rats show a dose response to increasing amounts of 6-MBOA.administered in Silastic capsule implants. Ovaries increased in size in response to capsules with 0.5-3.0 cm exposed surface area of 6-MBOA, whereas larger capsules (6 cm 6-MBOA) had no effect. Removal of the pituitary in both prepubertal and mature rats eliminated the stimulatory influence of 6-MBOA. In hypophysectomized animals treated with diethylstibestrol implants, 6-MBOA did not affect ovarian weight and no animals ovulated. Administration of follicle-stimulating hormone (FSH) increased ovarian weight and stimulated production of ova, and FSH combined with 6-MBOA resulted in larger ovaries that released more ova. 6-MBOA also enhanced ovarian growth in intact prepubertal animals treated with pregnant mare's serum gonadotropin. These results show that 6-MBOA has the ability to interact with FSH to stimulate follicular development and increase ovulation. Non-steroidal plant compounds may have a significant impact on the reproductive patterns of wild animal populations.

The plant metabolite, 6-methoxybenzoxazolinone, stimulates an increase in secretion of follicle-stimulating hormone and size of reproductive organs in Microtus pinetorum.

The plant metabolite, 6-methoxybenzoxazolinone (6-MBOA), occurring in leaf tissue of rapidly growing monocots, cues reproduction in some mammals. In the pine vole, Microtus pinetorum, peripubertal females respond to this nonestrogenic compound with a 40% increase in serum levels of follicle-stimulating hormone (FSH). In addition, 6-MBOA significantly increases the weight of the ovary and uterus in both peripubertal and mature voles. This study is the first to offer evidence that 6-MBOA interacts with the pituitary to stimulate reproduction in voles.

A naturally occurring plant compound, 6-methoxybenzoxazolinone, stimulates reproductive responses in rats.

A nonestrogenic component of young, rapidly growing plants, 6-methoxybenzoxazolinone (6-MBOA), was examined to determine its effect on the reproductive responses of prepubertal and mature female rats. Prepubertal animals treated with a single injection of 6-MBOA or with Silastic capsules implanted for 3 days showed a significant increase in both ovarian and uterine weight. Serum luteinizing hormone was unaffected by 6-MBOA treatment for 3 days in 32-day-old animals, whereas serum follicle-stimulating hormone was elevated. Silastic capsule treatment of mature animals showed the following results. Extended treatment for 6 estrous cycles had no influence on the timing of vaginal cyclicity; despite this, 6-MBOA treatment for 2 cycles caused an increase in ovarian weight resulting from an increase in the number of corpora lutea per ovary. Animals treated for 1 cycle showed a significant increase in the number of ova shed. Uterine weight in mature animals did not increase. This study indicates that 6-MBOA has a stimulatory effect on the reproductive system of young and mature female rats. It is the first attempt to relate the effects of the compound on the endocrine system of any animal. That nonestrogenic plant compounds can trigger reproduction has important ecologic and physiologic significance.

Male siblings inhibit reproductive activity in female pine voles, Microtus pinetorum.

Pine vole females paired in breeding cages with male siblings remain unreproductive beyond the age of puberty onset. In this study only 10% of females caged with their brothers reproduced, whereas 85% of females placed with strange males had litters. Mating between a female and a strange male was also suppressed by the presence of a male sibling sequestered behind a wire mesh barrier in the breeding cage. When the sibling male was removed from the cage after 1 day, 78% of the females produced litters. When the sibling remained behind the barrier in the breeding cage, only 42% gave birth to young conceived in his presence. Conception of second litters during the postpartum estrus occurred in over 80% of females caged with strange males alone and only 10% of females caged with sibling males. Female pine voles are induced to become reproductively active by strange males but this activity is depressed by the presence of a brother, and once initiated it does not continue if the female is caged with her brother.

Elderly adults' perception of their own cognitive development during the adult years.

Individuals between the ages of sixty-five and seventy-five were asked a number of questions regarding which of their cognitive abilities they think have changed with age and, further, what factors they think are responsible for such age changes. Questions were asked in two areas of cognitive functioning--memory and problem solving. With respect to memory, the reports of the elderly adults corresponded well with the results of memory research, which indicates that most memory abilities tend to decrease with increasing age. The elderly adults suggested that activity level, amount of contact with the information to be remembered, practice remembering, the perceived importance of the information to be remembered, and expectations regarding changes in memory are all factors that may contribute to age changes in memory. With respect to problem solving, on the other hand, the reports of the elderly did not correspond with the research. Research indicates that such abilities probably decline with increasing age while the elderly reported that they think that their problem-solving abilities have actually increased with age. Factors that were mentioned as possible causes of the reported increases in problem-solving ability were experience, good health, and taking more time to solve a problem.

The development of strategy use in a spatial task.

The ability of kindergarten, first grade, and third grade boys and girls to use a mnemonic strategy in a spatial task was investigated. Children (N = 90) were asked to replicate a model zoo. Use of an organizational strategy based on an object frame f reference was either required of the child, suggested, or not mentioned on the first trial. A second trial was conducted inwhich no strategy information was given. Analysis of the number of incorrect placements of model items indicated that the instruction had the greatest effect on the performance of the kindergarten children. Strategy instructions were also beneficial in reducing the time the children used to place items in the model but had no consistent effect on the amount of time the children used to examine the prototype.