Sex and Age Differences in Mate-Selection Preferences

For nearly 70?years, studies have shown large sex differences in human mate selection preferences. However, most of the studies were restricted to a limited set of mate selection criteria and to college students, and neglecting relationship status. In this study, 21,245 heterosexual participants between 18 and 65?years of age (mean age 41) who at the time were not involved in a close relationship rated the importance of 82 mate selection criteria adapted from previous studies, reported age ranges for the oldest and youngest partner that they would find acceptable, and responded to 10 yes/no questions about a potential marriage partner. For nearly all mate selection criteria, women were found to be the more demanding sex, although men placed consistently more value on the physical attractiveness of a potential partner than women. Also, the effects of the participants?? age and level of education were nearly negligible. These results demonstrate the robustness of sex differences in mate selection criteria across a substantial age range.     

仙琴蛙对不同类型声音的感知差异研究

既往研究发现听觉感知包括对声音信号的觉察、感觉、注意和知觉等多个认知过程,但依然不清楚大脑如何对不同类型的复杂声音信号(如同种鸣声和其他声音)进行解码和处理,以及在感知不同类型声音信号时大脑活动的动态特征.本研究记录了在随机播放白噪声和洞内鸣叫声音刺激时仙琴蛙Nidirana daunchina的左右端脑、间脑和中脑的...     

雄性大熊猫对化学信息行为反应的年龄差异

化学通讯对哺乳动物的生存和繁殖起着重要作用。研究了雄性大熊猫(Ailuropoda melanoleuca)对同伴个体尿液气味行为反应的发育模式。结果显示,在成年雌性个体的尿液气味刺激下,雄性个体表现显著多的嗅闻行为和嗅闻/舔舐环境行为,但是嘶咬气味刺激物的行为明显减少。在雌性个体的尿液气味刺激下,不同年龄段的雄性个体行为表现不同,成年雄性个体表现较亚成年和幼年个体显著多的舔舐行为。此外,成年个体和亚成年个体均表现较多的嗅闻/舔舐环境行为,而幼年个体则无该行为表现。幼年个体较成年和亚成年个体表现显著多的气味涂抹行为,而且嘶咬气味刺激物的时间较亚成年个体显著多。幼年个体和亚成年个体对雌性和雄性个体尿液气味刺激的行为反应不存在显著差异。研究结果表明,雄性大熊猫对同种个体尿液中化学信息的行为反应呈现出年龄差异。     

马铁菊头蝠对同种咀嚼声的反应研究

咀嚼是哺乳动物食物吸收的重要组成部分,对动物的生存和繁殖极其重要。动物咀嚼时会发出低频低强度的咀嚼声,研究表明人类的咀嚼声可以增强自身或他人的食欲和愉悦度。蝙蝠作为哺乳动物中的第二大类群,其咀嚼声的特征和功能仍不清楚。本研究以吉林省集安市治安村的马铁菊头蝠Rhinolophus ferrumequinum为研究对象,通过回放蝙蝠咀嚼声和空白对照实验,同步录制蝙蝠的进食行为和回声定位声波,试图阐明蝙蝠咀嚼声对其进食行为和回声定位声波的影响。结果表明:进食次数在2种回放条件下的差异无统计学意义,但捕食尝试在2种回放条件下的差异有统计学意义。因此,咀嚼声能够显著地提高蝙蝠的进食欲望。此外,在蝙蝠咀嚼声的刺激下,其回声定位声波的频率增加,持续时间延长,脉冲速率减慢。这可能是因为蝙蝠在咀嚼声的影响下改变发声动机,从而改变了其回声定位声波的频谱时间结构。本研究第一次报道了蝙蝠咀嚼声对其进食行为的影响,为进一步阐明蝙蝠咀嚼声的功能和进化具有重要意义。     

Sounds audible to migrating birds

We have measured sound levels from frog choruses in eastern New York State at altitudes of up to several hundred metres. Rana pipiens choruses from small ponds often could be recorded by a radio microphone up to 500 m, and on an especially favourable night with light winds they were clearly audible even at 965 m at about 20 dB SPL in the 1·5 to 2·5 2·5 kHz frequency band. Sound travels upward much farther and more predictably than along the surface. Many natural sounds, including those from frogs, insects, whitecaps, and perhaps wind-blown vegetation, arise from large areas and therefore act as extended sources. The intensities of such sounds decrease with altitude more slowly than expected from the inverse square law. Natural sound fields provide migrating birds with a potential source of information about the kind of land or water below them, and their progress over acoustic landmarks could inform them about wind velocity. Because atmospheric absorption increases with frequency, several hundred metres of air act as a low-pass filter, so that altitude could be estimated from the relative reduction of higher frequencies in a familiar sound.     

Sex and Age Differences in Levothyroxine Dosage Requirement

ObjectiveTo examine the performance of weightbased formulae for estimating the levothyroxine dosage requirement in athyreotic patients and to determine whether formula performance is affected by age, sex, or menstrual status.MethodsIn this prospective study, euthyroid study participants aged 18 to 65 years were followed up after total thyroidectomy at 4 time points: 6-8 weeks, 12-16 weeks, 6 months, and 1 year. Patient weight, serum thyrotropin concentration, and levothyroxine dosage required were recorded at each time point. The postoperative starting levothyroxine dosage was 1.7 mcg/kg daily for patients with benign thyroid disease and 2.2 mcg/kg daily for patients with thyroid cancer. Actual body weight was used to calculate the initial dosage. At steady state, adjustments were made in each patient’s levothyroxine dosage until the target thyrotropin concentration was reached. The levothyroxine dosage required to achieve this goal was documented.ResultsFifty patients were included (37 women, 13 men). Formulae based on actual body weight were accurate in achieving a normal thyrotropin concentration in 48% to 75% of participants. Final dosages to achieve normal thyrotropin values were similar in men (1.43 mcg/kg daily) and menopausal women (1.68 mcg/kg daily), but higher in premenopausal women (2.10 mcg/kg daily). When a formula based on ideal body weight was used, the requirement for menopausal women (2.34 mcg/kg daily) was similar to that of premenopausal women (2.44 mcg/kg daily), but the requirement for men (1.73 mcg/kg daily) remained lower than that observed in both female groups.ConclusionsWhen actual body weight was used to calculate levothyroxine dosage requirement, premenopausal women appeared to have a greater requirement than either menopausal women or men. When ideal weight was used, the requirement of all women was greater than that of men. Perhaps with formulae using actual weight, this apparent sex difference is masked by the greater weight, older age, or altered hormonal milieu of menopausal women. (Endocr Pract. 2010;16:71-79)     

Age Differences in the Response of Willow Tits (Parus montanus) to Conspecific Alarm Calls

Predation is an important mortality factor in wintering birds. To counter this, birds produce alarm calls in the presence of predators which serve to warn conspecifics. In social hierarchical bird flocks, adults survive the winter better than juveniles and therefore survival strategies probably vary with social status. This study examined the differential responses to alarm calls by free-living willow tits, Parus montanus, in dominance-structured winter flocks in Finland. To explore the age-dependent differences in response to conspecific alarm calls, a series with three alarm calls was played to focal adults and juveniles while they sat in the middle section of a spruce branch. Immediately after the playback, juvenile willow tits moved more often, flew longer distances and changed branches more often than did adults. Previous mammal studies have shown that juveniles are more likely to flee than adults after hearing conspecific alarm calls. The current study demonstrates that similar age-dependent responses to conspecific alarm calls occur in birds also. These findings reflect an increased vulnerability to predators or lack of experience of young birds.     

Differences in Patient Age Distribution between Influenza A Subtypes

Since the spring of 1977, two subtypes of influenza A virus (H3N2 and H1N1) have been seasonally infecting the human population. In this work we study the distribution of patient ages within the populations that exhibit the symptomatic disease caused by each of the different subtypes of seasonal influenza viruses. When the publicly available extensive information is pooled across multiple geographical locations and seasons, striking differences emerge between these subtypes. We report that the symptomatic flu due to H1N1 is distributed mainly in a younger population relative to H3N2. (The median age of the H3N2 patients is 23 years while H1N1 patients are 9 years old.) These distinct characteristic spectra of age groups, possibly carried over from previous pandemics, are consistent with previous reports from various regional population studies and also findings on the evolutionary dynamics of each subtype. Moreover, they are relevant to age-related risk assessments, modeling of epidemiological networks for specific age groups, and age-specific vaccine design. Recently, a novel H1N1 virus has spread around the world. Preliminary reports suggest that this new strain causes symptomatic disease in the younger population in a similar fashion to the seasonal H1N1 strains.     

Age Differences Between Spouses in a Brazilian Marriage Sample

Age differences between spouses were investigated in a Brazilian marriage sample. A study was made of 3,000 announcements of forthcoming marriages sampled from the newspaper Diario de Noticias de São Paulo, in September and October 1996. These announcements published in newspapers are a legal requirement for marriage. Men married women younger than themselves, and this tendency became more pronounced over the lifespan. There was only one exception: young men <20 years old married older partners. Young women married men older than themselves, but this tendency became less pronounced over the lifespan. Age differences between spouses violate the similarity-attraction rule, one of the strongest general principles of mate selection, but fit well with an evolutionary model.     

Differential Entrainment of Neuroelectric Delta Oscillations in Developmental Dyslexia

Oscillatory entrainment to the speech signal is important for language processing, but has not yet been studied in developmental disorders of language. Developmental dyslexia, a difficulty in acquiring efficient reading skills linked to difficulties with phonology (the sound structure of language), has been associated with behavioural entrainment deficits. It has been proposed that the phonological ‘deficit’ that characterises dyslexia across languages is related to impaired auditory entrainment to speech at lower frequencies via neuroelectric oscillations (<10 Hz, ‘temporal sampling theory’). Impaired entrainment to temporal modulations at lower frequencies would affect the recovery of the prosodic and syllabic structure of speech. Here we investigated event-related oscillatory EEG activity and contingent negative variation (CNV) to auditory rhythmic tone streams delivered at frequencies within the delta band (2 Hz, 1.5 Hz), relevant to sampling stressed syllables in speech. Given prior behavioural entrainment findings at these rates, we predicted functionally atypical entrainment of delta oscillations in dyslexia. Participants performed a rhythmic expectancy task, detecting occasional white noise targets interspersed with tones occurring regularly at rates of 2 Hz or 1.5 Hz. Both groups showed significant entrainment of delta oscillations to the rhythmic stimulus stream, however the strength of inter-trial delta phase coherence (ITC, ‘phase locking’) and the CNV were both significantly weaker in dyslexics, suggestive of weaker entrainment and less preparatory brain activity. Both ITC strength and CNV amplitude were significantly related to individual differences in language processing and reading. Additionally, the instantaneous phase of prestimulus delta oscillation predicted behavioural responding (response time) for control participants only.     

Sounds recorded in salt marshes and attributed to the European eel

The sounds were recorded in coastal ponds off the French Atlantic coast. They are characterized by continuous series of regularly spaced sounds, each sound being composed of one to four pulses of 7.8-ms duration. The main frequencies of these sounds are under 350 Hz. Due to the special characteristics of these sounds, their temporal patterning, their coastal pond provenance and their close similarity to sounds made by the American eel (Anguilla rostrata), we attribute them to the European eel (Anguilla anguilla).     

Age Differences in the Response of California Ground Squirrels (Spermophilus beecheyi) to Conspecific Alarm Calls

Juvenile California ground squirrel responses to adult alarm calls and juvenile alarm calling may be modified during development to achieve adult form. Adult conspecific chatter and whistle alarm calls were played back to juvenile and adult ground squirrels at an agricultural field site. In response to chatter playbacks, adults spent more time visually orienting to the environment and less time out of view and in covered habitats than juveniles; the converse was true in response to whistle playbacks. To test the evocativeness of juvenile calling, a subset of adult subjects received juvenile chatter and whistle playbacks. Adults spent less time out of view to juvenile call types than to adult calls, and showed more similar responses to juvenile chatters and whistles than to adult chatters and whistles. Age differences in the ground squirrel's alarm call system may reflect adjustments to changing risks during development.     

Oyster Larvae Settle in Response to Habitat-Associated Underwater Sounds

Following a planktonic dispersal period of days to months, the larvae of benthic marine organisms must locate suitable seafloor habitat in which to settle and metamorphose. For animals that are sessile or sedentary as adults, settlement onto substrates that are adequate for survival and reproduction is particularly critical, yet represents a challenge since patchily distributed settlement sites may be difficult to find along a coast or within an estuary. Recent studies have demonstrated that the underwater soundscape, the distinct sounds that emanate from habitats and contain information about their biological and physical characteristics, may serve as broad-scale environmental cue for marine larvae to find satisfactory settlement sites. Here, we contrast the acoustic characteristics of oyster reef and off-reef soft bottoms, and investigate the effect of habitat-associated estuarine sound on the settlement patterns of an economically and ecologically important reef-building bivalve, the Eastern oyster (Crassostrea virginica). Subtidal oyster reefs in coastal North Carolina, USA show distinct acoustic signatures compared to adjacent off-reef soft bottom habitats, characterized by consistently higher levels of sound in the 1.5–20 kHz range. Manipulative laboratory playback experiments found increased settlement in larval oyster cultures exposed to oyster reef sound compared to unstructured soft bottom sound or no sound treatments. In field experiments, ambient reef sound produced higher levels of oyster settlement in larval cultures than did off-reef sound treatments. The results suggest that oyster larvae have the ability to respond to sounds indicative of optimal settlement sites, and this is the first evidence that habitat-related differences in estuarine sounds influence the settlement of a mollusk. Habitat-specific sound characteristics may represent an important settlement and habitat selection cue for estuarine invertebrates and could play a role in driving settlement and recruitment patterns in marine communities.     

Differences in Bone Age Readings Between Pediatric Endocrinologists and Radiologists

Objective: Pediatric endocrinologists (PEs) have historically read their own bone age (BA) X-rays based on the belief that radiologists do not accurately interpret these tests. Whether there are significant differences in BA interpretations between these two groups has not been systematically explored. The objectives of the study were to compare BA readings performed by PEs and radiologists and determine whether clinical variables were associated with discrepancies in readings.Methods: A retrospective chart review of children presenting for initial evaluation of short stature (SS) or precocious puberty (PP) who had a BA X-ray completed was performed. Clinical variables analyzed included age, gender, ethnicity, Tanner stage, body mass index, reason for referral, radiologist location (Children's vs. outside hospital), and PE and radiologist BA readings using the Greulich and Pyle method.Results: Of 103 patients aged 9 ± 3.66 years, there was a discrepancy between the PE and radiologist readings on 70 images (68%). Discrepancy ranged from -1.5 to 3.5 years, with a mean of 4 ± 12 months. Patients referred for PP were more likely to have discrepant interpretations than those referred for SS (8.4 months vs. 0.8 months; P = .007). No differences were seen in interpretations between in-house radiologists and those at outside hospitals.Conclusion: Radiologists interpreted BAs differently than PEs in the majority of images. In patients referred for PP, BAs were interpreted as being older by radiologists than by PEs, perhaps due to bias from the reason for referral. Our results provide support for continued independent BA interpretations by PEs.Abbreviations: BA = bone age; GP = Greulich and Pyle; PE = pediatric endocrinologist; PP = precocious puberty; SS = short stature     

Neurophysiological Age Differences During Task-Performance in a Stereoscopic Virtual Environment

In today’s society, there is an increasing number of workplaces in virtual environments (VE). But, there are only a few reports dealing with occupational health issues or age effects. The question arises how VR generally interferes with cognitive processes. This interference might have relevant implications for workability and work-efficiency in virtual environments. Event-related potentials are known to reflect different stages of stimulus reception, evaluation, and response. We have established an electroencephalographic (EEG) monitoring, focussing on event-related potentials (N100; mismatch negativity, i.e., MMN) to obtain access to attention dependent and pre-attentive processing of sensory stimuli applied in VE. The MMN is known to be correlated with the ability of subjects to react to an unexpected event. The aim of the present study was to investigate cognitive responses to distracting auditory stimuli in two different age groups in a virtual environment (VE) and in a real environment (“real reality”), and to compare characteristic neurophysiological response patterns. Data show that stimulus detection as given by the N100 amplitude and latency does not differ in both age groups and task conditions. In contrast, the pre-attentive processing as given by the MMN is altered in the VR such as the non-VR condition in an age-related manner. A relevant finding of the present study was that the age related differences seen in the non-VR condition were not strengthened in VR.     

Reduced Neural Integration of Letters and Speech Sounds in Dyslexic Children Scales with Individual Differences in Reading Fluency

The acquisition of letter-speech sound associations is one of the basic requirements for fluent reading acquisition and its failure may contribute to reading difficulties in developmental dyslexia. Here we investigated event-related potential (ERP) measures of letter-speech sound integration in 9-year-old typical and dyslexic readers and specifically test their relation to individual differences in reading fluency. We employed an audiovisual oddball paradigm in typical readers (n = 20), dysfluent (n = 18) and severely dysfluent (n = 18) dyslexic children. In one auditory and two audiovisual conditions the Dutch spoken vowels/a/and/o/were presented as standard and deviant stimuli. In audiovisual blocks, the letter ‘a’ was presented either simultaneously (AV0), or 200 ms before (AV200) vowel sound onset. Across the three children groups, vowel deviancy in auditory blocks elicited comparable mismatch negativity (MMN) and late negativity (LN) responses. In typical readers, both audiovisual conditions (AV0 and AV200) led to enhanced MMN and LN amplitudes. In both dyslexic groups, the audiovisual LN effects were mildly reduced. Most interestingly, individual differences in reading fluency were correlated with MMN latency in the AV0 condition. A further analysis revealed that this effect was driven by a short-lived MMN effect encompassing only the N1 window in severely dysfluent dyslexics versus a longer MMN effect encompassing both the N1 and P2 windows in the other two groups. Our results confirm and extend previous findings in dyslexic children by demonstrating a deficient pattern of letter-speech sound integration depending on the level of reading dysfluency. These findings underscore the importance of considering individual differences across the entire spectrum of reading skills in addition to group differences between typical and dyslexic readers.