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People have a strong and reliable tendency to infer the character traits of strangers based solely on facial appearance. In five highly powered and pre-registered experiments, we investigate the relative merits of learning and nativist accounts of the origins of these first impressions. First, we test whether brief periods of training can establish consistent first impressions de novo. Using a novel paradigm with Greebles—a class of synthetic object with inter-exemplar variation that approximates that seen between individual faces—we show that participants quickly learn to associate appearance cues with trustworthiness (Experiments 1 and 2). In a further experiment, we show that participants easily learn a two-dimensional structure in which individuals are presented as simultaneously varying in both trustworthiness and competence (Experiment 3). Crucially, in the final two experiments (Experiments 4 and 5) we show that, once learned, these first impressions occur following very brief exposure (100 ms). These results demonstrate that first impressions can be rapidly learned and, once learned, take on features previously thought to hold only for innate first impressions (rapid availability). Taken together, these results highlight the plausibility of learning accounts of first impressions.

National and international guidelines on the treatment of attention deficit hyperactivity disorder (ADHD) in children and adolescents call for annual reviews to assess continuing need for medication by considering brief periods without medication, referred to as ‘Drug holidays’. However, drug holidays are reactively initiated by families, or recommended by practitioners if growth has been suppressed by medication rather than proactively to check the need. There is little evidence of planned, practitioner-initiated drug holidays from methylphenidate. The aim of this study was to identify what stops practitioners from routinely discussing planned drug holidays from methylphenidate with children, adolescents, and their parents. Practitioners involved in shared-care prescribing for children and adolescents with ADHD in one UK County were included. Interviews with 8 general practitioners (GPs) and 8 Child and Adolescent Mental Health Service (CAMHS) practitioners were conducted. Transcripts were analysed qualitatively against the components of the Capability–Opportunity–Motivation–Behaviour (COM-B) model. Possible interventions for increasing prescribers’ engagement with planned drug holidays were considered in response. Multiple barriers to practitioner engagement in planned drug holidays from methylphenidate were identified. Capability, in terms of knowledge and skills, was not a barrier identified for CAMHS practitioners but was for GPs. Opportunity was a main barrier for both groups, who reported lack of time and the absence of educational material about drug holidays. Motivation was more complex to define, with CAMHS practitioners questioning the need for drug holidays and GPs being more accepting due to worries about long-term medication side effects as well as cost savings. ‘Education’ and ‘enablement’ interventions were identified as key activities targeting all three components, which could feasibly increase uptake of practitioner-initiated planned drug holidays from methylphenidate. The application of the COM-B system identified a number of key barriers to practitioner engagement with drug holidays in children and adolescents with ADHD. Accordingly, a number of interventions could be developed to facilitate change. For example, educating and training GPs about ADHD management and drug holidays, and developing a decision aid to help families make informed decisions about whether or not to implement drug holidays could be used. Electronic supplementary material The online version of this article (10.1007/s12402-018-0258-9) contains supplementary material, which is available to authorized users.

The immediate and long-term effects of exposure to early life stress (ELS) have been documented in humans and animal models. Even relatively brief periods of stress during the first 10 days of life in rodents can impact later behavioral regulation and the vulnerability to develop adult pathologies, in particular an impairment of cognitive functions and neurogenesis, but also modified social, emotional, and conditioned fear responses. The development of preclinical models of ELS exposure allows the examination of mechanisms and testing of therapeutic approaches that are not possible in humans. Here, we describe limited bedding and nesting (LBN) procedures, with models that produce altered maternal behavior ranging from fragmentation of care to maltreatment of infants. The purpose of this paper is to discuss important issues related to the implementation of this chronic ELS procedure and to describe some of the most prominent endpoints and consequences, focusing on areas of convergence between laboratories. Effects on the hypothalamic-pituitary adrenal (HPA) axis, gut axis and metabolism are presented in addition to changes in cognitive and emotional functions. Interestingly, recent data have suggested a strong sex difference in some of the reported consequences of the LBN paradigm, with females being more resilient in general than males. As both the chronic and intermittent variants of the LBN procedure have profound consequences on the offspring with minimal external intervention from the investigator, this model is advantageous ecologically and has a large translational potential. In addition to the direct effect of ELS on neurodevelopmental outcomes, exposure to adverse early environments can also have intergenerational impacts on mental health and function in subsequent generation offspring. Thus, advancing our understanding of the effect of ELS on brain and behavioral development is of critical concern for the health and wellbeing of both the current population, and for generations to come.

Global positioning system (GPS) telemetry units are now small enough to be deployed on terrestrial and semi-aquatic turtles. Many of these GPS units use snapshot technology which collects raw satellite and timestamp data during brief periods of data recording to minimize size. We evaluated locations from snapshot GPS units in stationary tests and on wood turtles (Glyptemys insculpta) in northeastern Minnesota. Stationary GPS units were placed in wood turtle habitat to evaluate location accuracy, fix success rate, and directional bias. The GPS fix success rate and accuracy were reduced in closed canopy conditions and when the stationary GPS unit was placed under a log to simulate wood turtle hiding behavior. We removed GPS location outliers and used a moving average calculation to reduce mean location error in stationary tests from 27 m (SD = 38) to 10 m (SD = 8). We then deployed GPS units and temperature loggers on wood turtles and collected 122,657 GPS locations and 242,781 temperature readings from 26 turtles from May to September 2015 and 2016. Location outliers accounted for 12% of locations when the GPS receiver was on a turtle. We classified each wood turtle location based on the GPS location and by comparing temperature profiles from river, sun, and shaded locations to the temperature logger on the turtle. We estimated that wood turtles were on land 68% (SD = 12) of the time from May to September. The fix success rate for land locations was 38% (SD = 9), indicating that wood turtles often use habitats with obstructed views of the sky. Mean net daily movement was 55 m (SD = 192). Our results demonstrate that snapshot GPS units and temperature loggers provide fine-scale GPS data useful in describing spatial ecology and habitat use of semi-aquatic turtles.

Background: Short successive periods of physical inactivity occur throughout life and contribute considerably to the age-related loss of skeletal muscle mass. The maintenance of muscle mass during brief periods of disuse is required to prevent functional decline and maintain metabolic health. Objective: To assess whether daily leucine supplementation during a short period of disuse can attenuate subsequent muscle loss in vivo in humans. Methods: Thirty healthy (22 ± 1 y) young males were exposed to a 7-day unilateral knee immobilization intervention by means of a full leg cast with (LEU, n = 15) or without (CON, n = 15) daily leucine supplementation (2.5 g leucine, three times daily). Prior to and directly after immobilization, quadriceps muscle cross-sectional area (computed tomography (CT) scan) and leg strength (one-repetition maximum (1-RM)) were assessed. Furthermore, muscle biopsies were taken in both groups before and after immobilization to assess changes in type I and type II muscle fiber CSA. Results: Quadriceps muscle cross-sectional area (CSA) declined in the CON and LEU groups (p < 0.01), with no differences between the two groups (from 7712 ± 324 to 7287 ± 305 mm2 and from 7643 ± 317 to 7164 ± 328 mm2; p = 0.61, respectively). Leg muscle strength decreased from 56 ± 4 to 53 ± 4 kg in the CON group and from 63 ± 3 to 55 ± 2 kg in the LEU group (main effect of time p < 0.01), with no differences between the groups (p = 0.052). Type I and II muscle fiber size did not change significantly over time, in both groups (p > 0.05). Conclusions: Free leucine supplementation with each of the three main meals (7.5 g/d) does not attenuate the decline of muscle mass and strength during a 7-day limb immobilization intervention.

Play is an important part of normal childhood development and seen in many mammals, including rats. To better understand the interplay between genotype and postnatal experiences, the effects of neonatal handling on play were assessed in Lewis (LEW) and Fischer 344 (F344) rats. Handled litters experienced brief periods of separation during the first two postnatal weeks. F344 rats were less likely to direct nape contacts toward an untreated Sprague-Dawley (SD) partner and less likely to rotate to a supine position in response to a nape contact. When compared to rats from control litters, handled LEW, and F344 rats were more likely to respond to nape contacts with complete rotations, suggesting that handling increased playful responsiveness to a comparable extent in both strains. SD rats paired with handled inbred rats had more nape contacts than those paired with non-handled rats. While handled LEW rats also tended to direct more nape contacts to the SD partner than non-handled LEW rats there was no difference between handled and non-handled F344 rats. These results could not be readily explained by handling-induced changes in either maternal care or anxiety. These data suggest that the behavioral consequences of neonatal handling may not depend to a great extent on the genetic platform that these manipulations are acting on. These data also suggest that the ability to maintain the ebb and flow between playful solicitation and playful responsiveness may be compromised in F344 rats and may contribute to the lower levels of play in this strain.

We appreciate the comments of Drs. Rossello and Yellon regarding our recent paper [(1)][1], and we agree that activation of pro-survival pathways in viable myocytes after brief periods of ischemia likely occurs alongside apoptotic myocyte death to provide protection against subsequent ischemic

Short-term disuse and subsequent recovery affect whole muscle and single myofiber contractile function in young and old. While the loss and recovery of single myofiber specific force (SF) following disuse and rehabilitation has been shown to correlate with alterations in myosin concentrations in young, it is unknown whether similar relationships exist in old. Therefore, the purpose of the present study was to examine the effect of 14days lower limb disuse followed by 28days of active recovery on single muscle fiber myosin content in old (68yrs) and young (24yrs) recreationally physically active healthy men. Following disuse, myosin content decreased (p

Although looking time is used to assess infant perceptual and cognitive processing, little is known about the temporal structure of infant looking. To shed light on this temporal structure, 127 three-month-olds were assessed in an infant-controlled habituation procedure and presented with a pre-recorded display of a woman addressing the infant using infant-directed speech. Previous individual look durations positively predicted subsequent look durations over a six look window, suggesting a temporal dependency between successive infant looks. The previous look duration continued to predict the subsequent look duration after accounting for habituation-linked declines in look duration, and when looks were separated by an inter-trial interval in which no stimulus was displayed. Individual differences in temporal dependency, the strength of associations between consecutive look durations, are distinct from individual differences in mean infant look duration. Nevertheless, infants with stronger temporal dependency had briefer mean look durations, a potential index of stimulus processing. Temporal dependency was evident not only between individual infant looks but between the durations of successive habituation trials (total looking within a trial). Finally, temporal dependency was evident in associations between the last look at the habituation stimulus and the first look at a novel test stimulus. Thus temporal dependency was evident across multiple timescales (individual looks and trials comprised of multiple individual looks) and persisted across conditions including brief periods of no stimulus presentation and changes from a familiar to novel stimulus. Associations between consecutive look durations over multiple timescales and stimuli suggest a temporal structure of infant attention that has been largely ignored in previous work on infant looking.

Why did the emergence of our species require a timescale similar to the entire habitable period of our planet? Our late appearance has previously been interpreted by Carter (2008) as evidence that observers typically require a very long development time, implying that intelligent life is a rare occurrence. Here we present an alternative explanation, which simply asserts that many planets possess brief periods of habitability. We also propose that the rate-limiting step for the formation of observers is the enlargement of species from an initially microbial state. In this scenario the development of intelligent life is a slow but almost inevitable process, greatly enhancing the prospects of future SETI experiments such as the Breakthrough Listen project., 11 pages, 2 figures, published in the International Journal of Astrobiology, Figure 2 now includes new data point from Zhu et al

In the early 1990s, I started doing ethnographic research among Chinese migrants in Hungary, a project that lasted until 2004 and included brief periods of research in Russia, Yugoslavia, and Roman...

This Perspective focuses on two elements of our food supply and eating environment that facilitate high energy intake: a high eating rate and distraction of attention from eating. These two elements are believed to undermine our body's capacity to regulate its energy intake at healthy levels because they impair the congruent association between sensory signals and metabolic consequences. The findings of a number of studies show that foods that can be eaten quickly lead to high food intake and low satiating effects-the reason being that these foods only provide brief periods of sensory exposure, which give the human body insufficient cues for satiation. Future research should focus on the underlying physiological, neurological and molecular mechanisms through which our current eating environment affects our control of food intake.

The constructive nature of memory is generally adaptive, allowing us to efficiently store, process and learn from life events, and simulate future scenarios to prepare ourselves for what may come. However, the cost of a flexibly constructive memory system is the occasional conjunction error, whereby the components of an event are authentic, but the combination of those components is false. Using a novel recombination paradigm, it was demonstrated that details from one autobiographical memory may be incorrectly incorporated into another, forming autobiographical memory conjunction errors that elude typical reality monitoring checks. The factors that contribute to the creation of these conjunction errors were examined across two experiments. Conjunction errors were more likely to occur when the corresponding details were partially rather than fully recombined, likely due to increased plausibility and ease of simulation of partially recombined scenarios. Brief periods of imagination increased conjunction error rates, in line with the imagination inflation effect. Subjective ratings suggest that this inflation is due to similarity of phenomenological experience between conjunction and authentic memories, consistent with a source monitoring perspective. Moreover, objective scoring of memory content indicates that increased perceptual detail may be particularly important for the formation of autobiographical memory conjunction errors.

There is a minor error in the results section of the aforementioned publication. The current text on page 11, lines 340–344 reads: Conversely, as shown in Figure 3, the low mindful group had the greatest global efficiency in the auditory and insular cortices. An ROI analysis revealed that global efficiency in the insula/auditory cortex was significantly greater in the Low MAAS group compared to the High MAAS group for BOOST® (P = 0.01) and NO BOOST® (p = 0.02) conditions. It should read as follows: Conversely, as shown in Figure 3, the low mindful group had greater clustering of globally efficient nodes in the auditory and insular cortices. However, an ROI analysis revealed that the average global efficiency in the insula/auditory cortex was significantly greater in the High MAAS group compared to the Low MAAS group for both the BOOST® (p = 0.01) and NO BOOST® (p = 0.02) conditions. Thus, while the high global efficiency nodes were more densely clustered in the insula/auditory cortex for the Low MAAS group (Figure 3), the average global efficiency of those nodes was on average lower than the High MAAS group (Table 2).

This work was funded through the Atlantic Seal Research Programme, International Governance Programme (DFO), the Greenland Institute of Natural Resources, and a CFI grant to YFW. The authors also acknowledge the support of the Marine Alliance for Science and Technology for Scotland (MASTS) pooling initiative in the completion of this study. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. With the exception of relatively brief periods when they reproduce and moult, hooded seals, Cystophora cristata, spend most of the year in the open ocean where they undergo feeding migrations to either recover or prepare for the next fasting period. Valuable insights into habitat use and diving behaviour during these periods have been obtained by attaching Satellite Relay Data Loggers (SRDLs) to 51 Northwest (NW) Atlantic hooded seals (33 females and 18 males) during ice-bound fasting periods (2004−2008). Using General Additive Models (GAMs) we describe habitat use in terms of First Passage Time (FPT) and analyse how bathymetry, seasonality and FPT influence the hooded seals’ diving behaviour described by maximum dive depth, dive duration and surface duration. Adult NW Atlantic hooded seals exhibit a change in diving activity in areas where they spend >20 h by increasing maximum dive depth, dive duration and surface duration, indicating a restricted search behaviour. We found that male and female hooded seals are spatially segregated and that diving behaviour varies between sexes in relation to habitat properties and seasonality. Migration periods are described by increased dive duration for both sexes with a peak in May, October and January. Males demonstrated an increase in dive depth and dive duration towards May (post-breeding/pre-moult) and August–October (post-moult/pre-breeding) but did not show any pronounced increase in surface duration. Females dived deepest and had the highest surface duration between December and January (post-moult/pre-breeding). Our results suggest that the smaller females may have a greater need to recover from dives than that of the larger males. Horizontal segregation could have evolved as a result of a resource partitioning strategy to avoid sexual competition or that the energy requirements of males and females are different due to different energy expenditure during fasting periods. Publisher PDF

Individuals usually report for two objects of equal mass but different volume that the larger object feels lighter. This so-called size-weight illusion has been investigated for more than a century. The illusion is accompanied by increased forces, used to lift the larger object, resulting in a higher initial lifting speed and acceleration. The illusion holds when subjects know that the mass of the two objects is equal and it is likely that this also counts for the enlarged initial effort in lifting a larger box. Why should this happen? Under microgravity, subjects might be able to eliminate largely the weight-related component of the lifting force. Then, if persistent upward scaling of the weight-related force component had been the main cause of the elevated initial lifting force under normal gravity, this elevated force might disappear under microgravity. On the other hand, the elevated initial lifting effort in the large box would be preserved if it had been caused mainly by a persistent upward scaling of the force component, necessary to accelerate the object. To test whether the elevated initial lifting effort either persists or disappears under microgravity, a lifting experiment was carried out during brief periods of microgravity in parabolic flights. Subjects performed whole-body lifting movements with their feet strapped to the floor of the aircraft, using two 8-kg boxes of different volume. The subjects were aware of the equality of the box masses. The peak lifting forces declined almost instantaneously with approx. a factor 9 in the first lifting movements under microgravity compared with normal gravity, suggesting a rapid adaptation to the loss of weight. Though the overall speed of the lifting movement decreased under microgravity, the mean initial acceleration of the box over the first 200 ms of the lifting movement remained higher (P=0.030) in the large box (1.87+/-0.127 m/s2) compared with the small box (1.47+/-0.122 m/s2). Under normal gravity these accelerations were 3.30+/-0.159 m/s2 and 2.67+/-0.159 m/s2, respectively (P=0.008). A comparable trend was found in the initial lifting forces, being significant in the pooled gravity conditions (P=0.036) but not in separate tests on the normal gravity (P=0.109) and microgravity (P=0.169) condition. It is concluded that the elevated initial lifting effort with larger objects holds during short-term exposure to microgravity. This suggests that upward scaling of the force component, required to accelerate the larger box, is an important factor in the elevated initial lifting effort (and the associated size-weight illusion) under normal gravity.

During the first 60–70 years of the last century it was more or less possible to read everything that was published worldwide in whatever scientific speciality. This is no longer true. De Jong and Schaper [1] published a paper on the number of publications in clinical cardiovascular science including the citation of those papers over a 12-year period from 1981 to 1992. Of the 137 000 papers published during that period 46% remained uncited with a remarkable geographical variability from 31% for Norway to 69% for Japan. It should be realized that even a single citation by the authors themselves (self-citation) during such a long period would classify a paper in the cited category. Low citation is not synonymous with low scientific quality over brief periods (as used for popular bibliometric parameters as the ‘impact factor’) [2,3]. However, zero citation of about 62 000 papers over a 6-year period after publication [1], raises the question whether the scientific community should try to limit this flood of publications. This question becomes even more relevant when it is realized that electronic publishing will probably alleviate the burden of page limitations imposed on journal editors, and may lead to rejection rates that are more in agreement with reviewer’s recommendations [4]. It has been pointed out previously that rejection rates are much higher than what is actually advised by reviewers [4]. Fig. 1 shows the number of … * Corresponding author. Tel.: +31-30-253-8900; fax: +31-30-253-9036.

This study examined the effect of medication nonadherence on the return of positive symptoms among recent-onset schizophrenia patients.Three sets of operational criteria for medication nonadherence with differing levels of severity were compared for their ability to predict relapse. Explicit operational criteria are provided with the hope that they will be adopted by others. Psychotic symptoms were prospectively rated on a frequent basis, and systematic criteria were applied using a computer scoring program to identify periods of psychotic symptom return. In addition, a specialized statistical survival analysis method, optimal for examining risk periods and outcomes that can recur during the follow-up assessment, was used.As hypothesized, medication nonadherence robustly predicted a return of psychotic symptoms during the early phase of schizophrenia (hazard ratios=3.7-28.5, depending on the severity of nonadherence).Even brief periods of partial nonadherence lead to greater risk of relapse than what is commonly assumed. Patients in the early phase of schizophrenia should be cautioned about the possible consequences of partial or relatively brief periods of antipsychotic medication nonadherence.

This article compares civil-military relations in Turkey and Latin America. It finds that in both cases, military interruptions of democratic rule have been justified on grounds of military guardianship over national values and interests and feelings of professional superiority over civilians. It also finds that while the Turkish military ruled for brief periods, relying instead on extracting legal constitutional guarantees to maintain influence, Latin American militaries ruled for lengthier periods with less constitutional rewriting. In recent years, militaries in both places seem more willing to accept civilian policies even if they disagree with them.

We investigated whether positive daily peer-interactions counteract the effects of isolation in Octodon degus. Twenty-five-day-old degus were either isolated (ISO), socially housed (SOCIAL), or isolated and allowed 1-hr daily peer interaction (PARTIAL-ISO). The animals were observed over 4 weeks. Just prior to isolation and after 2 weeks of individual housing, the subjects were assessed for response to pleasant stimuli via a sucrose preference test and to fearful situations in open field and startle tests. Two weeks after the previous tests, the subjects were retested as above and observed in novelty and sociability tests. Only the ISO group showed significant alterations in sensitivity to reward and increased risk-taking behavior in fearful situations. The ISO group consumed more sucrose, spent less time freezing in the startle test and exhibited increased exploration in open field and novelty tests compared to PARTIAL-ISO and SOCIAL groups. In the sociability test, the SOCIAL group vocalized more than the other two groups during encounters with an unfamiliar degus. Our findings suggest that (i) chronic isolation induces alteration of hedonic, emotional and social profiles, with a maturational delay in fear-related responses; (ii) friendly interaction attenuates most behavioral changes induced by total social isolation. However, the positive effects of daily social interactions did not fully counteract deficits in social vocalizations. Our study represents one of the few available studies focused not only on the consequences of negative life events in this species, but also the protective role of relatively short periods of positive social activity on subsequent emotional development. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 53:280-290, 2011.

A transient, ischemia-resistant phenotype known as “ischemic tolerance” can be established in brain in a rapid or delayed fashion by a preceding noninjurious “preconditioning” stimulus. Initial preclinical studies of this phenomenon relied primarily on brief periods of ischemia or hypoxia as preconditioning stimuli, but it was later realized that many other stressors, including pharmacologic ones, are also effective. This review highlights the surprisingly wide variety of drugs now known to promote ischemic tolerance, documented and to some extent mechanistically characterized in preclinical animal models of stroke. Although considerably more experimentation is needed to thoroughly validate the ability of any currently identified preconditioning agent to protect ischemic brain, the fact that some of these drugs are already clinically approved for other indications implies that the growing enthusiasm for translational success in the field of pharmacologic preconditioning may be well justified.

When objects disappear from view, we can still bring them to mind, at least for brief periods of time, because we can represent those objects in visual short-term memory (VSTM) (Sperling, 1960; Cowan, 2001). A defining characteristic of this representation is that it is topographic, that is, it preserves a spatial organization based on the original visual percept (Vogel and Machizawa, 2004; Astle et al., 2009; Kuo et al., 2009). Recent research has also shown that features or locations of visual items that match those being maintained in conscious VSTM automatically capture our attention (Awh and Jonides, 2001; Olivers et al., 2006; Soto et al., 2008). But do objects leave some trace that can guide spatial attention, even without participants intentionally remembering them? Furthermore, could subliminally presented objects leave a topographically arranged representation that can capture attention? We presented objects either supraliminally or subliminally and then 1 s later re-presented one of those objects in a new location, as a “probe” shape. As participants made an arbitrary perceptual judgment on the probe shape, their covert spatial attention was drawn to the original location of that shape, regardless of whether its initial presentation had been supraliminal or subliminal. We demonstrate this with neural and behavioral measures of memory-driven attentional capture. These findings reveal the existence of a topographically arranged store of “visual” objects, the content of which is beyond our explicit awareness but which nonetheless guides spatial attention.

Mal de debarquement (MdD), the “sickness of disembarkment,” occurs when habituation to background rhythmic movement becomes resistant to readaption to stable conditions and results in a phantom perception of self motion typically described as rocking, bobbing, or swaying. Although several studies have shown that brief periods of MdD are common in healthy individuals, this otherwise natural phenomenon can become persistent in some individuals and lead to severe balance problems. Increased recognition of MdD in a persistent pathological form occurred after the publication of a case series of six patients by Brown and Baloh in 1987. Over 20 years later, although more is known about the clinical syndrome of persistent MdD, little is known about what leads to this persistence. This review addresses the clinical features of MdD, the associated symptoms in the persistent form, theories on pathogenesis, experience with treatment, and future directions for research.

Purpose—To characterize the temporal integration properties of the emmetropization process, the authors investigated the effects of brief daily interruptions of lens wear on the ocular compensation for negative lenses in infant rhesus monkeys. Methods—Eighteen monkeys wore −3 D lenses binocularly starting from approximately 3 weeks of age. Six of these monkeys wore the lenses continuously. For the other animals, the −3 D lenses were removed for four 15-minute periods each day. During these periods, the monkeys viewed through either zero-power lenses (n = 6) or +4.5 D lenses (n = 6). Three monkeys reared with binocular plano lenses and 16 monkeys reared normally served as controls. Refractive development was assessed by cycloplegic retinoscopy and A-scan ultrasonography. Results—As expected, the group of animals that wore the −3 D lenses continuously exhibited clear evidence of compensating axial myopia. These predictable myopic changes were mostly eliminated by the brief, daily periods of viewing through plano lenses. Interestingly, brief periods of viewing through +4.5 D lenses produced weaker protective effects. Conclusions—Brief periods of unrestricted vision can prevent the axial myopia normally produced by long daily periods of imposed hyperopic defocus. Thus, the temporal integration properties of the emmetropization process normally reduce the likelihood that transient periods of hyperopic defocus will cause myopia. Evidence from a wide range of animal species has demonstrated that emmetropization is an active process that is regulated by visual feedback associated with the eye's effective refractive state. 1–3 In particular, it has consistently been shown that early in life optically imposed alterations in the eye's refractive state can produce predictable compensating changes in axial growth. For example, negative lenses that displace the eye's secondary focal point beyond the retina (imposing hyperopic defocus) can increase axial growth rates, resulting in a reduction in the optical error that exists when viewing through the negative lens. Conversely, positive lenses that impose myopic defocus (shifting the focal point in front of the retina) can slow axial

PURPOSE: Brief periods of aerobic exercise training lead to reductions, rather then the expected increases in circulating IGF-I. We hypothesized that intense exercise training in adolescents initially leads to simultaneous increases in proinflammatory cytokines and decreases in activity of the GH/IGF-I axis; and that as exercise training proceeds, levels of proinflammatory cytokines become reduced, and a rebound in IGF-I ensues leading to the higher IGF-I levels. METHOD: To test this, we evaluated the GH/IGF-I axis and levels of inflammatory cytokines (IL-6, TNF-alpha, IL-1beta, IL-1ra), body composition, and fitness in 13 healthy adolescent boys (mean age 15.9 +/- 0.3 yr) over the course of a high-school wrestling season. Subjects were tested preseason, midseason (6 wk), peak season (12-14 wk), and 4 wk postseason. RESULTS: No significant weight loss was noted throughout the season. During the wrestling season (mid and peak) both total (P < 0.046) and free (P < 0.002) IGF-I levels decreased, whereas proinflammatory cytokines (IL-1ra, P < 0.005; IGFBP-1, P < 0.013; and IGFBP-2, P < 0.025) increased. GHBP (P < 0.018) levels also decreased during the season. In the postseason, there were significant increases in GHBP, and free and total IGF-I, whereas proinflammatory cytokines decreased. CONCLUSIONS: An initial catabolic-type hormonal response occurs with intense exercise training in adolescents. This is followed by a rebound in circulating growth factors when the period of heavy training ceases.

Ca 2+ influx through voltage-gated Ca 2+ channels and the resulting elevation of intracellular Ca 2+ concentration, [Ca 2+ ] i , triggers transmitter release in nerve terminals. However, it is controversial whether in addition to the opening of Ca 2+ channels, membrane potential directly affects transmitter release. Here, we assayed the influence of membrane potential on transmitter release at the calyx of Held nerve terminals. Transmitter release was evoked by presynaptic Ca 2+ uncaging, or by presynaptic Ca 2+ uncaging paired with presynaptic voltage-clamp depolarizations to +80 mV, under pharmacological block of voltage-gated Ca 2+ channels. Such a change in membrane potential did not alter the Ca 2+ dependence of transmitter release rates or synaptic delays. We also found, by varying the amount of Ca 2+ influx during Ca 2+ tail-currents, that the time course of phasic transmitter release is not invariant to changes in release probability. Rather, the time difference between peak Ca 2+ current and peak transmitter release became progressively shorter with increasing Ca 2+ current amplitude. When this time difference was plotted as a function of the estimated local [Ca 2+ ] i at the sites of vesicle fusion, a slope of ≈100 μs per 10 μM [Ca 2+ ] i was found, in reasonable agreement with a model of cooperative Ca 2+ binding and vesicle fusion. Thus, the amplitude and time course of the [Ca 2+ ] i signal at the sites of vesicle fusion controls the timing and the amount of transmitter release, both under conditions of brief periods of Ca 2+ influx, as well as during step-like elevations of [Ca 2+ ] i produced by Ca 2+ uncaging.

The effectiveness of various stimulus identification (decoding) procedures for extracting the information carried by the responses of a population of neurons to a set of repeatedly presented stimuli is studied analytically, in the limit of short time windows. It is shown that in this limit, the entire information content of the responses can sometimes be decoded, and when this is not the case, the lost information is quantified. In particular, the mutual information extracted by taking into account only the most likely stimulus in each trial turns out to be, if not equal, much closer to the true value than that calculated from all the probabilities that each of the possible stimuli in the set was the actual one. The relation between the mutual information extracted by decoding and the percentage of correct stimulus decodings is also derived analytically in the same limit, showing that the metric content index can be estimated reliably from a few cells recorded from brief periods. Computer simulations as well as the activity of real neurons recorded in the primate hippocampus serve to confirm these results and illustrate the utility and limitations of the approach.

Multiple brief periods of rapid ventricular pacing confer both short- and long-term protection on the ischaemic heart. The duration of the short-term protection does not exceed 2 h, whereas the long-term protective effect appears several hours after the inducing insults, with maximal protection 24–48 h later. Up to now, delayed cardiac protection by preceding ischaemic insults against harmful consequences of stress has been produced in the normal, healthy animal only. The purpose of this study was, therefore, to test whether delayed cardiac protection can be induced in experimental atherosclerosis in rabbits produced by feeding cholesterol-rich diet over 2 months. Repeated brief periods of rapid ventricular pacing were used to induce delayed protection of the heart. Moderation of post-pacing right intracavitary ST segment elevation and that of the left ventricular end-diastolic pressure (both produced by ventricular overpacing: 500 beats/min for 15 min) were found in normal animals as well as in those fed cholesterol-enriched diet. The short-lived protection induced by a single ‘preconditioning’ pacing was reproducible only in normal animals. As measured by means of radioimmunoassay, the protective effect of either short- or long-term protection appeared in parallel with an attenuation of ischaemia-induced increase in cardiac cyclic AMP content, in both normal and atherosclerotic rabbits. An increase in cardiac cyclic GMP content was characteristic of the short- but not long-term protection. These results suggest that the delayed cardiac protection by preceding multiple brief rapid pacings operates even in experimental atherosclerosis, but the short-term protection induced by a single preconditioning stimulus is lost.

Background Despite considerable analysis and preventive strategies, brachial plexus injuries remain fairly common in the perioperative setting. These injuries range from brief periods of numbness or discomfort in the immediate postoperative period to, in rare cases, profound, prolonged losses of sensation and function. We present a case of an orthopedic surgery patient who suffered a brachial plexus injury while under anesthesia after trying to sit upright with his arms restrained. Case presentation After the uneventful placement of an intramedullary tibial nail, an 18 year old patient tried to sit upright with his arms restrained while still under the influence of anesthesia. In the immediate postoperative period, the patient complained of a profound loss of sensation in his left arm and an inability to flex his left elbow, suppinate his arm, or abduct and rotate his shoulder. Neurological examination and subsequent studies revealed a C5-6 brachial plexus injury. The patient underwent range of motion physical therapy and, over the next three months, regained the full function and sensation of his left arm. Conclusion Restraining arms during general anesthesia to prevent injury remains a wise practice. However, to avoid injuring the brachial plexus while the arms are restrained, extra caution must be used to prevent unexpected patient movement and to ensure gentle emergence.

The occurrence and duration of the carrier state in familial associates of recognized cases of poliomyelitis was studied by the examination for virus of stool specimens collected from the members of four families at regular intervals for a period of over 2 months. The results indicate that: (1) virus may persist in their stools continuously for 4 to 5 weeks; (2) virus may be encountered intermittently in the stools; (3) in some instances virus may be present for brief periods only; (4) children are more likely to maintain virus than are adults in the same family; (5) infection of a family takes place rapidly, suggesting again simultaneous infection from a common source.

When this bungalow was designed a certain functional independence was established between the living zone of the married couple, and that of the children. The top floor is taken up with the bedroom of the parents, and the social and common living zone. On the ground floor there is a playing room for the children, as well as their bedrooms, and a service bedroom. The design follows a simple outline, and is of modern conception; its main purpose being to house a large family during the summer time and at other brief periods of the year. The large garage accommodates in winter a motorboat and also serves as workshop.Al planificar y organizar este Chalet se estableció una cierta independencia entre las zonas de vida del matrimonio y la de los hijos. La planta superior contiene: el dormitorio y anexos de los padres y la zona de vida social y comunitaria. La inferior comprende: la sala de juegos de los nifíos y sus dormitorios, y el dormitorio de servicio. Fue diseñado a base de líneas sencillas, modernas y elegantes, con el fin de albergar a una familia numerosa durante las vacaciones estivales y en algún otro corto período de primavera u otoño. El garaje, de amplias dimensiones, da acogida en invierno a una embarcación y sirve también como taller.

The four series of experiments described above indicate clearly that tetanic stimulation of the sinus region of the auricles is of material assistance to massage in the resuscitation of the heart. It causes the auricles to generate impulses, either rhythmical or irregular, to which the ventricles, when susceptible, respond. When massage administered for brief periods has failed to resuscitate the heart, the same period of massage combined with tetanic stimulation of the sinus has usually brought the circulation back to normal. In some instances massage alone when continued over long periods has been without effect, and to all appearances would have continued to be without effect, whereas at such a time massage combined with stimulation of the sinus has effected recovery. Whether the stimulus causes the auricles to beat normally or to fibrillate seems to make no essential difference in the end result. Not infrequently conductivity and irritability are lowered to such an extent by the cessation of the circulation, that impulses generated in an auricle started by stimulation can at first manifest no effect upon the ventricles. Under such circumstances massage alone or, more frequently, massage plus stimulation may cause the ventricles to beat with their inherent slow rate. Often then the force of the ventricular contractions is insufficient for the maintenance of an effective circulation. In such cases, however, with the gradual improvement in the condition of the heart, the auricular impulses, as a rule, soon begin to reach the ventricles, with the result that the latter immediately begin to beat more rapidly and effectively. The beneficial results of stimulation of the auricles, therefore, manifest themselves relatively late, but none the less effectively. It has been found that even after the heart has begun to beat, stimulation of the sinus region may still be of some assistance, though in another direction. It not infrequently happens that after resuscitation of the heart the blood pressure fails to rise above a certain low and insufficient level. In such cases repeated tetanic stimulation of the sinus may accelerate the rise of blood pressure and so hasten recovery (protocol of experiment 12, series II, and text-figure 5). No attempt has been made to determine the mechanism of this effect.

SummaryUse is a major factor driving plasticity of cortical processing and cortical maps. As demonstrated of blind Braille readers and musicians, long-lasting and exceptional usage of the fingers results in the development of outstanding sensorimotor skills and in expansions of the cortical finger representations. However, how periods of disuse affect cortical representations and perception in humans remains elusive. Here, we report that a few weeks of hand and arm immobilization by cast wearing significantly reduced hand use and impaired tactile acuity, associated with reduced activation of the respective finger representations in the somatosensory cortex (SI), measured by functional magnetic resonance imaging. Hemodynamic responses in the SI correlated positively with hand-use frequency and negatively with discrimination thresholds, indicating that reduced activation was most prominent in subjects with severe perceptual impairment. We found, strikingly, compensatory effects on the contralateral, healthy hand consisting of improved perceptual performance compared to healthy controls. Two to three weeks after cast removal, perceptual and cortical changes recovered, whereas tactile acuity on the healthy side remained superior to that on the formerly immobilized side. These findings suggest that brief periods of reduced use of a limb have overt consequences and thus constitute a significant driving force of brain organization equivalent to enhanced use.

A laboratory-based sprint running test has been devised to examine the performance characteristics and metabolic responses of an individual to 30 seconds of maximal exercise. A non-motorised treadmill was used so that the individual was able to sprint at his own chosen speed and also to vary his speed as fatigue occurred. The treadmill was instrumented so that the chosen speeds as well as the equivalent distance travelled could be monitored by micro-computer throughout the test. The test-retest reliability of the procedure was investigated with 14 recreational runners who performed the test on different days. A good correlation (r = 0.93) was found between the values obtained for peak running speeds on the two occasions. In an attempt to establish whether or not this test could be used to identify the differences in the performance characteristics of highly trained individuals, the responses to the test of eleven sprint trained and eleven endurance trained athletes were examined. The sprint trained athletes covered a greater distance (162.2 +/- 5.95 m vis 153.51 +/- 12.32 m; p less than 0.01) and had higher blood lactate concentrations (16.52 +/- 1.23 mM vis 12.98 +/- 1.77 mM; p less than 0.01) than the endurance trained athletes. Therefore this laboratory sprint running test offers an additional way of investigating human responses to brief periods of high intensity exercise.

The injection of the anticoagulant mepesulphate (Treburon) into the cerebral ventricles of cats resulted in tremor, salivation, tachypnoea, loud calling, and brief periods of various forms of seizures followed by progressive reduction in spontaneous movements and somnolence. The possible sites of action for these effects are discussed.

To provide a systematic description of component movements of upper facial chorea in Huntington disease, consecutive videos of 25 active patients with confirmed diagnosis were scored on eye opening, eye closing, and procerus/corrugator contractions. Of the 25 patients evaluated, 76% exhibited intermittently widened palpebral fissures associated with frontalis contractions. Brief periods of repetitive but irregular blinking were observed in 16%. 8% had brief spasms of the orbital portion of the orbicularis oculi muscles. In addition, brief contractions of procerus and corrugator supercilii muscles were noted in 52%. Electronic supplementary material The online version of this article (doi:10.1186/2054-7072-1-7) contains supplementary material, which is available to authorized users.