Can endocranial volume be used as an estimate of brain size in birds?

2002 ◽  
Vol 80 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Andrew N Iwaniuk ◽  
John E Nelson

Endocranial volumes of vertebrate skulls and brain masses are often used interchangeably in comparative analyses of brain size. We test whether endocranial volume can be used as a reliable estimate of brain size in birds by comparing endocranial volumes with brain masses across 82 species using absolute values and with respect to body size. The results of paired tests across all 82 species and within two orders, Passeriformes and Psittaciformes, did not yield a significant difference between the two measures. These results were supported by correlational analyses that showed a significant positive relationship between endocranial volume and brain mass. Unpaired tests within short-tailed shearwaters (Puffinus tenuirostris) and paired tests within budgerigars (Melopsittacus undulatus) also yielded no significant differences between endocranial volume and brain mass. Thus, a combination of interspecific and intraspecific comparisons indicates that endocranial volume does provide a reliable estimate of brain size. Although this may enable more rapid collection of avian brain size data, endocranial volume should be used with caution because it cannot account for seasonal and age-related variation and cannot be used to measure differences in brain structure.

2020 ◽  
Vol 95 (2) ◽  
pp. 113-122
Author(s):  
Diego Ocampo ◽  
César Sánchez ◽  
Gilbert Barrantes

The ratio of brain size to body size (relative brain size) is often used as a measure of relative investment in the brain in ecological and evolutionary studies on a wide range of animal groups. In birds, a variety of methods have been used to measure the brain size part of this ratio, including endocranial volume, fixed brain mass, and fresh brain mass. It is still unclear, however, whether these methods yield the same results. Using data obtained from fresh corpses and from published sources, this study shows that endocranial volume, mass of fixed brain tissue, and fresh mass provide equivalent estimations of brain size for 48 bird families, in 19 orders. We found, however, that the various methods yield significantly different brain size estimates for hummingbirds (Trochilidae). For hummingbirds, fixed brain mass tends to underestimate brain size due to reduced tissue density, whereas endocranial volume overestimates brain size because it includes a larger volume than that occupied by the brain.


2016 ◽  
Vol 88 (3-4) ◽  
pp. 235-257 ◽  
Author(s):  
Sam H. Ridgway ◽  
Kevin P. Carlin ◽  
Kaitlin R. Van Alstyne ◽  
Alicia C. Hanson ◽  
Raymond J. Tarpley

We compared mature dolphins with 4 other groupings of mature cetaceans. With a large data set, we found great brain diversity among 5 different taxonomic groupings. The dolphins in our data set ranged in body mass from about 40 to 6,750 kg and in brain mass from 0.4 to 9.3 kg. Dolphin body length ranged from 1.3 to 7.6 m. In our combined data set from the 4 other groups of cetaceans, body mass ranged from about 20 to 120,000 kg and brain mass from about 0.2 to 9.2 kg, while body length varied from 1.21 to 26.8 m. Not all cetaceans have large brains relative to their body size. A few dolphins near human body size have human-sized brains. On the other hand, the absolute brain mass of some other cetaceans is only one-sixth as large. We found that brain volume relative to body mass decreases from Delphinidae to a group of Phocoenidae and Monodontidae, to a group of other odontocetes, to Balaenopteroidea, and finally to Balaenidae. We also found the same general trend when we compared brain volume relative to body length, except that the Delphinidae and Phocoenidae-Monodontidae groups do not differ significantly. The Balaenidae have the smallest relative brain mass and the lowest cerebral cortex surface area. Brain parts also vary. Relative to body mass and to body length, dolphins also have the largest cerebellums. Cortex surface area is isometric with brain size when we exclude the Balaenidae. Our data show that the brains of Balaenidae are less convoluted than those of the other cetaceans measured. Large vascular networks inside the cranial vault may help to maintain brain temperature, and these nonbrain tissues increase in volume with body mass and with body length ranging from 8 to 65% of the endocranial volume. Because endocranial vascular networks and other adnexa, such as the tentorium cerebelli, vary so much in different species, brain size measures from endocasts of some extinct cetaceans may be overestimates. Our regression of body length on endocranial adnexa might be used for better estimates of brain volume from endocasts or from endocranial volume of living species or extinct cetaceans.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257803
Author(s):  
David A. Waugh ◽  
J. G. M. Thewissen

Most authors have identified two rapid increases in relative brain size (encephalization quotient, EQ) in cetacean evolution: first at the origin of the modern suborders (odontocetes and mysticetes) around the Eocene-Oligocene transition, and a second at the origin of the delphinoid odontocetes during the middle Miocene. We explore how methods used to estimate brain and body mass alter this perceived timing and rate of cetacean EQ evolution. We provide new data on modern mammals (mysticetes, odontocetes, and terrestrial artiodactyls) and show that brain mass and endocranial volume scale allometrically, and that endocranial volume is not a direct proxy for brain mass. We demonstrate that inconsistencies in the methods used to estimate body size across the Eocene-Oligocene boundary have caused a spurious pattern in earlier relative brain size studies. Instead, we employ a single method, using occipital condyle width as a skeletal proxy for body mass using a new dataset of extant cetaceans, to clarify this pattern. We suggest that cetacean relative brain size is most accurately portrayed using EQs based on the scaling coefficients as observed in the closely related terrestrial artiodactyls. Finally, we include additional data for an Eocene whale, raising the sample size of Eocene archaeocetes to seven. Our analysis of fossil cetacean EQ is different from previous works which had shown that a sudden increase in EQ coincided with the origin of odontocetes at the Eocene-Oligocene boundary. Instead, our data show that brain size increased at the origin of basilosaurids, 5 million years before the Eocene-Oligocene transition, and we do not observe a significant increase in relative brain size at the origin of odontocetes.


Author(s):  
A. E. Chernikova ◽  
Yu. P. Potekhina

Introduction. An osteopathic examination determines the rate, the amplitude and the strength of the main rhythms (cardiac, respiratory and cranial). However, there are relatively few studies in the available literature dedicated to the influence of osteopathic correction (OC) on the characteristics of these rhythms.Goal of research — to study the influence of OC on the rate characteristics of various rhythms of the human body.Materials and methods. 88 adult osteopathic patients aged from 18 to 81 years were examined, among them 30 men and 58 women. All patients received general osteopathic examination. The rate of the cranial rhythm (RCR), respiratory rate (RR) heart rate (HR), the mobility of the nervous processes (MNP) and the connective tissue mobility (CTM) were assessed before and after the OC session.Results. Since age varied greatly in the examined group, a correlation analysis of age-related changes of the assessed rhythms was carried out. Only the CTM correlated with age (r=–0,28; p<0,05) in a statistically significant way. The rank dispersion analysis of Kruskal–Wallis also showed statistically significant difference in this indicator in different age groups (p=0,043). With the increase of years, the CTM decreases gradually. After the OC, the CTM, increased in a statistically significant way (p<0,0001). The RCR varied from 5 to 12 cycles/min in the examined group, which corresponded to the norm. After the OC, the RCR has increased in a statistically significant way (p<0,0001), the MNP has also increased (p<0,0001). The initial heart rate in the subjects varied from 56 to 94 beats/min, and in 15 % it exceeded the norm. After the OC the heart rate corresponded to the norm in all patients. The heart rate and the respiratory rate significantly decreased after the OC (р<0,0001).Conclusion. The described biorhythm changes after the OC session may be indicative of the improvement of the nervous regulation, of the normalization of the autonomic balance, of the improvement of the biomechanical properties of body tissues and of the increase of their mobility. The assessed parameters can be measured quickly without any additional equipment and can be used in order to study the results of the OC.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1417
Author(s):  
Binafsha M. Syed ◽  
Andrew R. Green ◽  
Emad A. Rakha ◽  
David A.L. Morgan ◽  
Ian O. Ellis ◽  
...  

As age advances, breast cancer (BC) tends to change its biological characteristics. This study aimed to explore the natural progression of such changes. The study included 2383 women with clinically T0-2N0-1M0 BC, managed by primary surgery and optimal adjuvant therapy in a dedicated BC facility. Tissue micro-arrays were constructed from their surgical specimens and indirect immunohistochemistry was used for analysis of a large panel (n = 16) of relevant biomarkers. There were significant changes in the pattern of expression of biomarkers related to luminal (oestrogen receptor (ER), progesterone receptors (PgR), human epidermal growth factor receptor (HER-2), E-cadherin, MUC1, bcl2 CK7/8, CK18 and bcl2) and basal (CK5/6, CK14, p53 and Ki67) phenotypes, lymph node stage, histological grade and pathological size when decade-wise comparison was made (p < 0.05). The ages of 40 years and 70 years appeared to be the milestones marking a change of the pattern. There were significantly higher metastasis free and breast cancer specific survival rates among older women with ER positive tumours while there was no significant difference in the ER negative group according to age. Biological characteristics of BC show a pattern of change with advancing age, where 40 years and 70 years appear as important milestones. The pattern suggests <40 years as the phase with aggressive phenotypes, >70 years as the less aggressive phase and 40–70 years being the transitional phase.


2021 ◽  
pp. 1-10
Author(s):  
Christiane Völter ◽  
Lisa Götze ◽  
Imme Haubitz ◽  
Janine Müther ◽  
Stefan Dazert ◽  
...  

<b><i>Introduction:</i></b> Age-related hearing loss affects about one-third of the population worldwide. Studies suggest that hearing loss may be linked to cognitive decline and auditory rehabilitation may improve cognitive functions. So far, the data are limited, and the underlying mechanisms are not fully understood. The study aimed to analyze the impact of cochlear implantation on cognition in a large homogeneous population of hearing-impaired adults using a comprehensive non-auditory cognitive assessment with regard to normal-hearing (NH) subjects. <b><i>Material and Methods:</i></b> Seventy-one cochlear implant (CI) candidates with a postlingual, bilateral severe or profound hearing loss aged 66.3 years (standard deviation [SD] 9.2) and 105 NH subjects aged 65.96 years (SD 9.4) were enrolled. The computer-based neurocognitive tool applied included 11 subtests covering attention (M3), short- and long-term memory (recall and delayed recall), working memory (0- and 2-back, Operation Span [OSPAN] task), processing speed (Trail Making Test [TMT] A), mental flexibility (TMT B), inhibition (cFlanker and iFlanker), and verbal fluency. CI patients underwent a neurocognitive testing preoperatively as well as 12 months postoperatively. Impact of hearing status, age, gender, and education on cognitive subdomains was studied. Additionally, after controlling for education and age, cognitive performance of CI subjects (<i>n</i> = 41) was compared to that of NH (<i>n</i> = 34). <b><i>Results:</i></b> CI users achieved significantly better neurocognitive scores 12 months after cochlear implantation than before in most subtests (M3, [delayed] recall, 2-back, OSPAN, iFlanker, and verbal fluency; all <i>p</i> &#x3c; 0.05) except for the TMT A and B. A significant correlation could be found between the postoperative improvement in speech perception and in the attentional task M3 (<i>p</i> = 0.01). Hearing status (<i>p</i> = 0.0006) had the strongest effect on attention, whereas education had a high impact on recall (<i>p</i> = 0.002), OSPAN (<i>p</i> = 0.0004), and TMT A (<i>p</i> = 0.005) and B (<i>p</i> = 0.003). Inhibition was mainly age-dependent with better results in younger subjects (<i>p</i> = 0.016). Verbal fluency was predicted by gender as females outperformed men (<i>p</i> = 0.009). Even after controlling for age and education NH subjects showed a significantly better performance than CI candidates in the recall (<i>p</i> = 0.03) and delayed recall (<i>p</i> = 0.01) tasks. Postoperatively, there was no significant difference between the 2 groups anymore. <b><i>Conclusion:</i></b> Impact of cochlear implantation on neurocognitive functions differs according to the cognitive subdomains. Postoperatively, CI recipients performed as good as age- and education-matched NH subjects.


1983 ◽  
Vol 65 (2) ◽  
pp. 155-157 ◽  
Author(s):  
T. G. Cotter ◽  
K. O'Malley

1. Neutrophils from drug-free elderly subjects produced approximately 50% less cyclic AMP in response to isoprenaline than did neutrophils from young subjects. A significant difference in basal cyclic AMP levels was also evident (elderly 2.8 ± 0.37; young 4.9 ± 0.36 pmol of cAMP/107 cells; P < 0.05). 2. With a range of anti-neutrophil monoclonal antibodies no evidence of age-related neutrophil population heterogeneity was found. 3. These findings indicate that the age-related decline in β-adrenoceptor responsiveness is not due to changes in the neutrophil population. 4. The present results support the hypothesis that there is a generalized decline in β-adrenoceptor-mediated responsiveness in the elderly.


2021 ◽  
Vol 11 (1) ◽  
pp. 129-134
Author(s):  
Tiecheng Wang ◽  
Shaochong Bu ◽  
Fang Tian ◽  
Hong Zhang

The present study sought to investigate and compare the accuracy of two third-generation intraocular lens calculation formulas contrasted against three new-generation intraocular lens calculation formulas regarding their ability to predict postoperative refraction following cataract surgery. A retrospective case study following 172 patients (172 eyes) exhibiting age-related cataracts in their eyes who were subject to phacoemulsification between September 2017 and September 2018 at the Department of Cataracts, Tianjin Medical University Eye Hospital, was carried out. Based upon ocular axial length, the sampled patients were grouped into a short axis group (ocular axial length ≤ 22 mm; 17 cases; 17 eyes), a normal axis group (22 mm < ocular axial length ≥ 24.5 mm; 132 cases; 132 patients), and a long axis group (ocular axial length > 24.5 mm; 23 cases; 23 eyes); mean absolute prediction error (MAE) postoperative refraction in each group was determined using five formulas, and the percentage of eyes displaying postoperative myopic shift symptoms, postoperative hyperopic shift symptoms, alongside the percentage of eyes displaying postoperative refractive shift symptoms in the range of (−0.25 to 0.25 D, −0.50 to 0.50 D, −1.00 to 1.00 D), were all calculated following the procedures of the five selected formulas. The MAE of the 172 patient cases was compared within the five selected formulas, and SRK/T possessed the highest prediction accuracy, exhibiting a significant difference from the other four formulas (P < 0.05), with accuracy levels subsequently followed by the Holladay 1 and Barrett Universal II formulas-however, the two formulas lacked a significant difference between them (P > 0.05). In addition, the MAE of the normal axial group was compared and analyzed within the five formulas, with analysis revealing that the SRK/T, Holladay 1, and Barrett Universal II formulas exhibited strong prediction accuracy, with no significant difference present among these three formulas (P > 0.05), and also revealing a significantly difference between the aforementioned formulas and remaining two formulas (P < 0.05). For further analysis, the MAE of the short axis group was compared, and the SRK/T and Haigis (Holladay 1, and Barrett Universal II) demonstrated stronger prediction accuracy when compared to the Olsen formula (P < 0.05). Finally, the MAE of the long axis group was compared, and it was found that the SRK/T and Barrett Universal II formulas exhibits the best prediction accuracy, followed by the Haigis and Holladay 1 formulas, with no significant difference (P > 0.05) between the former two formulas or the latter two. The majority of patients exhibited hyperopic shift post-surgery. Of the five formulas studied, the SRK/T and Barrett Universal II formulas possessed strong accuracy capable of predicting postoperative refraction. However, more long-term observation, including large patient samples, is necessary in order to corroborate our result.


Author(s):  
Л. Е. Голованова ◽  
Е. А. Огородникова ◽  
Е. С. Лаптева ◽  
М. Ю. Бобошко

Целью исследования было изучение качества жизни лиц с нарушениями слуха в разных возрастных группах. Обследованы 100 пациентов, обратившихся в городской сурдологический центр для взрослых в связи с нарушением слуха: 50 человек - 34-59 лет, 50 - 60 лет и старше, из которых 32 человека были пожилого возраста (60-74 года)и 18 - старческого (75-86 лет). Степень тугоухости оценивали на основании результатов тональной пороговой аудиометрии. Для исследования качества жизни все пациенты заполняли общий опросник MOS SF-36, отражающий физический и психологический компоненты здоровья, а также специальный опросник HHIА(E)-S для лиц с нарушениями слуха. Установлено, что шкала HHIА(E)-S демонстрирует высокую корреляцию со степенью тугоухости у пациентов моложе 60 лет ( R =0,98; достоверность различий на уровне p <0,05), которая снижается у пациентов 60 лет и старше ( R =0,94; различия в оценках при разной степени тугоухости недостоверны). Значительные трудности в старшей возрастной группе могут быть связаны с тем, что людям пожилого и, особенно, старческого возраста сложно пользоваться слуховыми аппаратами (или они для них неэффективны) и оценивать свои затруднения по шкалам опросника. Целесообразно использовать шкалу HHIА(Е)-S в качестве скринингового инструмента для раннего выявления тугоухости, направления пациентов к сурдологу и своевременного слухопротезирования. The aim of the research was to study the quality of life in hearing impaired patients of different age. 100 patients referred to the city audiology centre because of their hearing disorders were examined: 50 patients from 34 to 59 years old and 50 patients from 60 years and older, from which 32 patients were of older age (60 to 74 years old) and 18 of oldest age (75 to 86 years old). A degree of hearing loss was assessed according to results of pure tone audiometry. To study the quality of life all patients filled in the questionnaire MOS SF-36, which evaluates physical and psychological components of health, and the questionnaire HHIA(E)-S, designed specifically for patients with hearing disorders. The HHIA(E)-S scale was found to show high correlation with hearing loss degree in patients younger than 60 years old ( R =0,98 with statistically significant difference, p <0,05), with decreasing correlation in patients from 60 years and older ( R =0,98; no significant difference while assessing various hearing loss degrees). Considerable difficulties in this age group may be explained by the fact, that older and especially oldest patients have a challenge with hearing aids usage (or they are of low efficiency for them) and with assessing theirs difficulties on the questionnaire scales. The HHIA(E)-S scale is useful as a screening tool for early detection of hearing loss, referral of patients to an audiologist and prompt hearing aid fitting.


Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Tomoko Hashimoto

Although the daily urinary sodium excretion (UNaV) is considered to provide the most reliable estimate of the daily sodium intake, it may be affected by salt loss due to sweating in summer. However, theseasonal variation in the daily UNaV associated with a normal lifestyle is unknown. This study was performed in 348 outpatients from the Morioka region during three seasons: summer(summer 1), winter, and the following summer (summer 2). The daily UNaV (g salt/day) was estimated by the second morning urine method three times during each season. Seasonal variation was defined as a significant trend across the three seasons together with a significant difference between winter and both summers. In women, the daily UNaV was higher in winter (11.8±3.0 g salt/day) than in summer 1 (11.2±2.9g salt/day) or summer 2 (11.0±2.9 g salt/day). In contrast, there was no marked seasonal variation in men. An analysis stratified by age (4 quartiles) identified seasonal variation in the older 2 quartiles of women (aged ≧68 years). In these women, the mean seasonal difference in the daily UNaV was 0.9 g of salt/day for both winter vs. summer 1 and winter vs. summer 2, while it was 0.1-0.8 g of salt/day in the other groups. Seasonal variation in the daily UNaV only occurred in older female patients and was relatively small. This is evidence for restricting salt intake throughout the year and should reassure patients who are anxious about salt loss due to sweating in summer.


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