Adaptive blinded sample size adjustment for comparing two normal means--a mostly Bayesian approach.

Adaptive sample size redetermination (SSR) for clinical trials consists of examining early subsets of on-trial data to adjust prior estimates of statistical parameters and sample size requirements. Blinded SSR, in particular, while in use already, seems poised to proliferate even further because it obviates many logistical complications of unblinded methods and it generally introduces little or no statistical or operational bias. On the other hand, current blinded SSR methods offer little to no new information about the treatment effect (TE); the obvious resulting problem is that the TE estimate scientists might simply 'plug in' to the sample size formulae could be severely wrong.

[The effects of video games on cognitive aging].

Advancing age is associated with cognitive decline, which, however, remains a very heterogeneous phenomenon. Indeed, several extrinsic factors seem to modulate the effect of aging on cognition. Recently, several studies have provided evidence that the practice of video games could engender many benefits by favoring the maintenance of cognitive vitality in the elderly.

Effects of interactive physical-activity video-game training on physical and cognitive function in older adults.

The purpose of the present study was to assess the potential of exergame training based on physically simulated sport play as a mode of physical activity that could have cognitive benefits for older adults. If exergame play has the cognitive benefits of conventional physical activity and also has the intrinsic attractiveness of video games, then it might be a very effective way to induce desirable lifestyle changes in older adults. To examine this issue, the authors developed an active video game training program using a pretest-training-posttest design comparing an experimental group (24 × 1 hr of training) with a control group without treatment.

Age effects shrink when motor learning is predominantly supported by nondeclarative, automatic memory processes: evidence from golf putting.

Can motor learning be equivalent in younger and older adults? To address this question, 48 younger (M = 23.5 years) and 48 older (M = 65.0 years) participants learned to perform a golf-putting task in two different motor learning situations: one that resulted in infrequent errors or one that resulted in frequent errors.

The surgical treatment of Balanitis Xerotica Obliterans.

Background: Balanitis Xerotica Obliterans (BXO) is a chronic, often progressive disease, which can lead to phimosis and urethral stenosis, affecting both urinary and sexual function. Steroid creams are usually the first-line treatment but have a limited role and surgical intervention is frequently necessary. Conservative surgical procedures (circumcision) are often preferred in the first instance with the premise that recurrence of disease will require a more definitive reconstruction.

Relationship between behavior, adrenal activity, and environment in zoo-housed western lowland gorillas (Gorilla gorilla gorilla).

Monitoring adrenal activity through noninvasive fecal hormone sampling is rapidly gaining popularity as a tool to assess zoo animal welfare. However, few studies have sought to investigate the interrelationships between behavior, adrenal activity, and environment, and ask whether both behavioral and adrenal monitoring strategies are required to assess welfare sufficiently. We present the findings of a 9-month study of a small group (one male, two females) of Western lowland gorillas, Gorilla gorilla gorilla.

Input, retention, and output factors affecting adult age differences in visuospatial short-term memory.

Objectives: The sources of age differences in short-term memory for spatial locations were explored in 2 experiments that examined factors related to input, to maintenance, and to output.

Method: In each experiment, 4 dots were presented briefly, followed after a retention interval by a probe dot, which was judged to either match or not match one of the 4 memory-set dots.

Results And Discussion: Results showed that poorer performance by older adults could be attributed independently to reduced visual acuity, to less effective use of rehearsal strategies, and to differences in response biases.

Dual-task processing in younger and older adults: similarities and differences revealed by fMRI.

fMRI was used to explore age differences in the neural substrate of dual-task processing. Brain activations when there was a 100 ms SOA between tasks, and task overlap was high, were contrasted with activations when there was a 1000 ms SOA, and first task processing was largely complete before the second task began. Younger adults (M=21 yrs) showed activation in dorsolateral prefrontal cortex and in parietal areas as well as in ventral medial frontal cortex and sub-lobar areas.

A demonstration of dual-task performance without interference in some older adults.

Highly efficient dual-task processing is demonstrated when reaction time to each of two tasks does not differ between the dual-task situation and the single-task situation. This has been demonstrated reliably in younger adults; nevertheless, the two extant studies of extensive dual-task training did not find evidence for it in any elderly adult. The origins of age-related differences after training were explored in a study in which the stimuli for the two tasks were perfectly redundant although two distinct responses were required.

Probing the depths of informant discrepancies: contextual influences on divergence and convergence.

This study examined how a contextual approach to child assessment can clarify the meaning of informant discrepancies by focusing on children's social experiences and their if…then reactions to them. In a sample of 123 children (M(age) = 13.30) referred to a summer program for children with behavior problems, parent-teacher agreement for syndromal measures of aggression and withdrawal was modest.

Toxoplasma gondii antibodies in wild white-lipped peccary (Tayassu pecari) from Peru.

In the Peruvian Amazon, the white-lipped peccary (Tayassu pecari) is a desirable game species and is important for the local rural economy. Blood samples from 101 white-lipped peccaries from Peru were collected from 3 different conservation areas located in the municipalities of Manu and Tambopata, southeastern region of the Peruvian Amazon. Antibodies were assayed using the modified agglutination test (MAT, cut of value of 25).

Hypofractionated accelerated radiotherapy with concurrent carboplatin for locally advanced squamous cell carcinoma of the head and neck.

Aims: Hypofractionated accelerated radiotherapy with concurrent carboplatin utilises both advantages of altered fractionation and synchronous chemotherapy to maximise local control in locally advanced head and neck cancer. Such fractionation schedules are increasingly used in the intensity-modulated radiotherapy era and the aim of this study was to determine the outcome of hypofractionated accelerated radiotherapy with carboplatin.

Materials And Methods: One hundred and fifty consecutive patients with squamous cell carcinoma of the larynx, oropharynx, oral cavity and hypopharynx (International Union Against Cancer [IUAC] stage II-IV) treated with 55Gy in 20 fractions over 25 days with concurrent carboplatin were analysed.

Correlation of currently used radiobiological parameters with local control and acute and late mucosal toxicity in randomised studies of altered fractionation for locally advanced head and neck cancer.

Aims: There has been a resurgence in interest in radiobiological modelling in head and neck cancer. The aim of this study was to determine if currently used parameters accurately predict both tumour and toxicity outcomes.

Materials And Methods: Trials were identified from a recent meta-analysis of altered fractionation.

Learning to bypass the central bottleneck: declining automaticity with advancing age.

Does advancing age reduce the ability to bypass the central bottleneck through task automatization? To answer this question, the authors asked 12 older adults and 20 young adults to first learn to perform an auditory-vocal task (low vs. high pitch) in 6 single-task sessions. Their dual-task performance was then assessed with a psychological refractory period paradigm, in which the highly practiced auditory-vocal task was presented as Task 2, along with an unpracticed visual-manual Task 1.

Can synchronous chemotherapy be added to accelerated hypofractionated radiotherapy in patients with base of tongue cancer?

Aim: To evaluate the tolerability of synchronous chemotherapy and accelerated hypofractionated radiotherapy in patients with locally advanced squamous cell carcinoma of the base of the tongue.

Materials And Methods: Between 1999 and 2004, 43 patients with stage II-IV squamous cell carcinoma of the base of the tongue were treated with a combined modality of radiotherapy (prescribed 55 Gy in 20 fractions), synchronous chemotherapy and in some cases surgical neck dissection. End points were acute and late toxicity, 3 year locoregional control, overall survival, cancer-specific survival and compliance.

Radiobiological modelling of the therapeutic ratio for the addition of synchronous chemotherapy to radiotherapy in locally advanced squamous cell carcinoma of the head and neck.

Aims: To model the therapeutic gain from the addition of synchronous chemotherapy to radiotherapy in locally advanced head and neck cancer.

Materials And Methods: Refinements to previous methodology, including the derivation of weighted estimates of key parameters from randomised studies and the use of the expected mucosal biologically effective dose concept, have been used to produce an evidence-based assessment of the benefit from the addition of chemotherapy when considering acute grade 3 mucositis and rates of 5-year local control.

Results: For a value of alpha=0.

Establishing molecular tools for genetic manipulation of the pleuromutilin-producing fungus Clitopilus passeckerianus.

We describe efficient polyethylene glycol (PEG)-mediated and Agrobacterium-mediated transformation systems for a pharmaceutically important basidiomycete fungus, Clitopilus passeckerianus, which produces pleuromutilin, a diterpene antibiotic. Three dominant selectable marker systems based on hygromycin, phleomycin, and carboxin selection were used to study the feasibility of PEG-mediated transformation of C. passeckerianus.