scholarly journals Interpopulational variation in human brain size: implications for hominin cognitive phylogeny

2021 ◽  
Vol 84 (4) ◽  
pp. 405-429
Author(s):  
Gary Clark ◽  
Maciej Henneberg

Abstract Throughout the hominin lineage brain size is believed to have increased threefold – increase which, it is argued by some researchers, results in the enhanced brain power that distinguishes humans from any other living being. However, as we demonstrate in this article this supposed increase is the result of comparing the species mean of contemporary humans with other great apes and fossil hominins. This method obscures both interpopulational variation among modern humans, and the fact that the putative increases in the mean are the result of an increase in the upper limit in some populations, which has the result of obscuring the relative stasis in the lower limit over the last 600k years. For example, populations such as Aboriginal Australians have a range that is more different from Danes than it is from that of Asian H. erectus over the last 600ka. Yet Aboriginal Australians, whose unique anatomy seems to be related to the climatic conditions of Australia, possess all of the socio-cognitive traits characteristic of all other modern-day populations – yet they seemed not to have undergone increase in brain size to the degree that many other populations have. In this instance brain size seems to be unrelated to cognition. In this article we present a statistical analysis of interpopulational variation in contemporary humans and why such an analysis is crucial for our understanding of hominin cognitive, social and technological evolution. We also suggest how such variation may add to our understanding of hominin ontogeny or life history. Additionally, we develop a model based on humanity’s unique form of embodied social cognition that results from our upright bipedal posture and hand morphology. This model is then used to explain the results of our statistical analysis and the possible factors underpinning the human emergence.

2015 ◽  
Vol 94 (4) ◽  
pp. 459-463 ◽  
Author(s):  
Ural Oguz ◽  
Aykut Aykac ◽  
Erhan Demirelli ◽  
Eyup Burak Sancak ◽  
Berkan Resorlu ◽  
...  

Purpose: To investigate whether or not the age of spontaneous resolution of monosymptomatic nocturnal enuresis (MNE) was familial. Patients and Methods: A questionnaire was administered to more than 1,500 people, and 100 appropriate participants were identified from four referral hospitals. We included the participants who had MNE and whose parents also had MNE with spontaneous resolution. Then the association between the spontaneous resolution time of MNE in parents and that in their children was investigated. Results: The mean ages of spontaneous resolution were 10.7 (10-30 years), 9.4 (6-17 years) and 10.9 (6-18 years) in participants, their mothers and their fathers, respectively. According to the statistical analysis, there was a positive correlation between participants and both their mothers and fathers (p < 0.05). In addition, it was revealed that familial MNE history based on first- and second-degree relatives, in addition to their parents, was also associated with the increased spontaneous resolution age of MNE (p < 0.05). According to our results, gender and parents' education status were not statistically associated with the spontaneous resolution (p > 0.05). Conclusion: As a conclusion, the age of spontaneous resolution of MNE is familial. Although the exact reasons of spontaneous resolution still remain a mystery; further genetic investigations may be able to resolve this mystery.


1954 ◽  
Vol 45 (1) ◽  
pp. 19-27 ◽  
Author(s):  
R. Braude ◽  
P. M. Clarke ◽  
K. G. Mitchell

1. A survey and. statistical analysis of the records of litters born in the N.I.R.D. herd of Large White pigs over a period of 16 years are presented.2. The mean length of gestation was 114 days for both gilts and sows.3. The mean numbers of pigs born alive and born dead per litter from gilts, 10·0 and 0·2 respectively, were both significantly smaller than the corresponding figures for sows, 11·8 and O·8. No seasonal differences were found.4. The mean total losses of pigs from birth to weaning at 8 weeks were 29·5% of pigs born alive. The losses in litters from gilts, 23·0%, were significantly smaller than in litters from sows, 31·0%. The losses during the winter months both for gilts, 32·5%, and for sows, 35·9%, were significantly higher than during the summer months, 19·4% and 26·7% for gilts and sows respectively.5. Over 50% of the total losses were due to crushing by the dam, 74·1% of the losses from this cause occurring during the first 48 hr. after birth.6. The mean number of pigs weaned per litter was 8·0. The difference between the number weaned per litter from gilts, 7·7, and per litter from number of pigs was weaned per litter from sows during the summer months, 8·7, than during the winter months, 7·4.7. There was no significant difference between the number of male and of female pigs weaned.8. The mean weight at weaning was 29·9 lb., male pigs, 30·3 lb., being significantly heavier than females, 29·51b. Pigs in litters from gilts, 27·81b., were significantly lighter at weaning than those from sows, 30·0 lb., and for both gilts and sows, pigs reared during the summer months, 29·7 and 31·8 lb. respectively, were significantly heavier than those reared during the winter months, 25·9 and 28·2 lb. respectively.


2013 ◽  
Vol 04 (S 01) ◽  
pp. S31-S34 ◽  
Author(s):  
Shin Yi Ng ◽  
Ki Jinn Chin ◽  
Tong Kiat Kwek

ABSTRACT Background: Leucopenia has been reported after induction of thiopentone barbiturate therapy for refractory intracranial hypertension. However, the incidence and characterisitics are not well described. Aims: We performed a retrospective review to describe the incidence and characteristics of leucopenia after induction of thiopentone barbiturate therapy. Setting and Design: Our centre is a national referral centre for neurotrauma and surgery in a tertiary medical institution.Materials and Methods: We performed a retrospective review of all patients who received thiopentone barbiturate therapy for refractory intracranial hypertension during an 18 month period from January 2004 to June 2005 in our neurosurgical intensive care unit. Statistical Analysis Used: Statistical analysis was performed using SPSS version 15.0. All data are reported as mean ± standard deviation or median (interquartile range). The Chi square test was used to analyze categorical data and student t test done for comparison of means. For paired data, the paired t?test was used.-test was used. Results: Thirty eight (80.9%) out of 47 patients developed a decrease in white blood cell (WBC) count after induction of thiopentone barbiturate coma. The mean decrease in WBC from baseline to the nadir was 6.4 × 10 9 /L (P <lt; 0.001) and occurred 57 (3-147) h after induction. The mean nadir WBC was 8.6 < 3.6 × 10 9 /L. Three (6.4%) patients were leucopenic, with a WBC count of 2.8, 3.1, and 3.6 < 10 9 /L. None of them were neutropenic. We did not find an association between decrease in WBC count and clinical diagnosis of infection. We did not find any association between possible risk factors such as admission GCS, maximum ICP prior to induction of barbiturate coma, APACHE II score, total duration and dose of thiopentone given, and decrease in WBC count. Conclusions: Decrease in WBC count is common, while development of leucopenia is rare after thiopentone barbiturate coma. Regular monitoring of WBC counts is recommended.


Author(s):  
Tijjani Ahmed Abali ◽  
Nehemiah Japheth Kalang ◽  
Simon Lee

Water is a sustaining element which is vital for all living being ,the discharge is a major concept in hydrography that presents information on the availability of water for human use and resource management. The aim of the research is to analyze the volume of discharge of River Benue at Jimeta with a view to provide early warning changes for flood. The primary data used were sounding, planimetric points and the velocity while the secondary data includes the discharge of previous years of 1999, 2002, and 2012 and the topographic map of the study area. The statistical analysis carried out using ANOVA to ascertain the assessment of the discharge; the result shows that there was decrease in the volume of discharge in the preceding years. The average velocity of water obtained was 1.03 m/s; it is as a result of the channel platform with 1.42% slope within the study area .In conclusion, the volume of discharge is decreasing with increase in sedimentation within the study area. Based on the findings of the research, it is recommended that there should be restoration measures such as dredging and buffer zone so as to create more space for adequate flow of water and to reduce the risk of flooding.


Dairy farming is vulnerable to seasonal variable factors such as temperature, cold climatic conditions, and rainfall. These affect the production and reproduction traits of dairy animals. Seasonal variability also affects the quantity of consumption and marketing of milk considerably. The study aimed to assess the seasonal fluctuation in milk production in Sivagangai District Cooperative Milk Producer Union Limited (SDCMPUL), Tamil Nadu. The study used secondary data. The milk production data were collected from SDCMPUL, Karaikudi, Tamil Nadu. The data covered the period from 2001-02 to 2020-21. The study used descriptive statistics, CAGR, and paired ‘t-test to determine the variation of milk production according to seasonal changes. The MS office - Excel software and SPSS software were used to analyse the data. The results revealed that the mean milk production of the lean and flush season was 2.46 and 2.30 lakh liters, and the CAGR of milk production in SDCMPUL, Tamil Nadu, during the period 2001-02 to 2020-21 was 5.65 percent, and it was 5.23 percent in lean season and 6.11 percent in the flush season while the growth rate of milk production during the lean and flush season was positive and was significant statistically. It was found that the quantity of milk production was higher in the lean season than a flush season; however, the variability of milk production was more in the flush season than in the lean season.


2002 ◽  
Vol 6 (3) ◽  
pp. 497-506 ◽  
Author(s):  
L. Ruiz ◽  
S. Abiven ◽  
P. Durand ◽  
C. Martin ◽  
F. Vertès ◽  
...  

Abstract. The hydrological and biogeochemical monitoring of catchments has become a common approach for studying the effect of the evolution of agricultural practices on water resources. In numerous studies, the catchment is used as a "mega-lysimeter" to calculate annual input-output budgets. However, the literature reflects two opposite interpretations of the trends of nitrate concentration in streamwater. For some authors, essentially in applied studies, the mean residence time of leached nitrate in shallow groundwater systems is much less than one year and river loads reflect annual land use while for others, nitrate is essentially transport limited, independent of soil nitrate supply in the short term and annual variations reflect changes in climatic conditions. This study tests the effect of agricultural land-use changes on inter-annual nitrate trends on stream water of six small adjacent catchments from 0.10 to 0.57 km2 in area, on granite bedrock, at Kerbernez, in Western Brittany (France). Nitrate concentrations and loads in streamwater have been monitored for nine years (1992 to 2000) at the outlet of the catchments. An extensive survey of agricultural practices from 1993 to 1999 allowed assessment of the nitrogen available for leaching through nitrogen budgets. For such small catchments, year-to-year variations of nitrate leaching can be very important, even when considering the 'memory effect' of soil, while nitrate concentrations in streamwater appear relatively steady. No correlation was found between the calculated mean nitrate concentration of drainage water and the mean annual concentration in streams, which can even exhibit opposite trends in inter-annual variations. The climatic conditions do not affect the mean concentration in streamwater significantly. These results suggest that groundwater plays an important role in the control of streamwater nitrate concentration. Keywords: nitrate, diffuse pollution, agricultural catchment, nitrogen budget, leaching, Kerbernez catchments


2018 ◽  
Vol 6 (2) ◽  
pp. 66
Author(s):  
Dr Harpreet Kaur Gandhoke ◽  
Dr Vasanti Lagali Jirge ◽  
Dr Anjana Bagewadi

Background: Studies estimating the Tobacco- specific nitrosamines, (TSNA’s) which are the strongest carcinogens in the saliva oftobacco users and tobacco quitters, are limited.Objectives: To assess and compare the levels of N- nitrosamines (NNN, NNK) in the saliva of tobacco chewers and non -chewers including those who have quit the habit of tobacco use.Methods: The study included 120 patients who were divided into three groups of 40 each: Group I- Smokeless tobacco chewersGroup II- Tobacco chewers who have completely stopped the habit at least 2 weeks prior to sample collection andGroup III- non-chewers. The salivary levels of two tobacco specific nitrosamines; NNN & NNK levels were estimated in the three study groups. Statistical analysis was done by Kruskal– Wallis, one-way analysis of variance (ANOVA) test, Mann-Whitney U test. (p-value < 0.05 was considered to be statistically significant)Results: In Group I, the mean level of NNN was 651.84 ± 359.78 and mean level of NNK was 168.32 ± 131.83. In Group II, the mean level of NNN was 119.52 ± 95.05 and mean level of NNK was 42.78 ± 43.19. In Group III, the mean level of NNN was 3.44 ±6.55 and mean level of NNK was 1.98 ± 3.68. There was a statistical difference in the 3 groups with respect to mean levels of NNN and NNK.Conclusion: The study indicated that salivary tobacco-specific nitrosamines are elevated in tobacco chewers. Saliva can be used to detect TSNA’s and screen for TSNA’s during each patient’s de-addiction process.  


2015 ◽  
Vol 10 (2) ◽  
pp. 90 ◽  
Author(s):  
Stefano Canali ◽  
Gabriele Campanelli ◽  
Corrado Ciaccia ◽  
Mariangela Diacono ◽  
Fabrizio Leteo ◽  
...  

In sustainable agricultural systems, intercropping using living mulches (LM) provides many beneficial ecosystem services. The objective of these two-year field experiments was to study the suitability of different LM options of burr medic (<em>Medicago polymorpha</em> L. var. <em>anglona</em>) for organic cauliflower (<em>Brassica oleracea</em> L.) cultivation in two sites under Mediterranean conditions. In central Italy (Experiment 1) contemporary and delayed (to crop) sowings of LM were compared with a no-cover crop treatment, contrasting two local cauliflower cultivars and a F1 Hybrid. In southern Italy (Experiment 2) the sustainability of systems combining LM (anticipated and contemporary sowing compared with no-cover) and organic fertilisation strategies was assessed. The aboveground biomasses dry weights of cauliflower crop (heads and residues), burr medic and weeds were separately determined. Results suggested that in Experiment 1 the LM was not able to smother weeds establishment and growth, as a consequence of early sowing, while cauliflower yield was reduced. Moreover, the genotypes behaviour was greatly influenced by the LM sowing times. In Experiment 2, irrespective of the agronomic practices applied, climatic conditions notably influenced cauliflower cultivation and also reduced the mean yield. Therefore, the recorded differences between the two experimental sites highlighted the need to tailor the LM strategies to the different environmental conditions.


Nematology ◽  
2014 ◽  
Vol 16 (2) ◽  
pp. 229-243 ◽  
Author(s):  
Wim Van Den Berg ◽  
Olaf Hartsema ◽  
Loes J.M.F. Den Nijs

A series of proficiency tests on potato cyst nematode (PCN; ) and free-living stages of Meloidogyne and Pratylenchus () were investigated to determine the accuracy and precision of the nematode counts and to gain insights into possible trends and potential improvements. In each test, each participating laboratory received ten samples of soil collected from naturally infested fields and well mixed before distribution. The variance between the counts from the ten samples, estimated per test and laboratory, was constant for PCN cysts and free-living stages of Meloidogyne spp. and Pratylenchus spp. during the period monitored. However, during the initial years, the variance between the samples showed a downward trend for PCN living juveniles. The variance between the laboratories, estimated per test, was constant for PCN cysts over the period 1994-2010. For PCN living juveniles the variance between laboratory means declined from 1994-2000 and from 2000 it was more or less constant, which coincided with the introduction of a well-described new methodology. For Meloidogyne spp. and Pratylenchus spp., from 1998-2005 the variance between laboratory means was more or less constant or increased. From 2006, all participating laboratories incubated the organic matter and the variance between the laboratories was stable and below the levels observed during 2003-2005. After discarding data from initial years with unstable variances of the nematode counts, a meta-analysis was carried out on the remaining data using HGLMs to model the mean and variance of the counts simultaneously. The within-laboratory variance for the ten samples and the interaction variance of test and laboratory were estimated and combined to percentage coefficient of variation (%CV) per laboratory. For PCN cysts, %CV per laboratory ranged from 12.6 to 41.6 and for PCN juveniles in sandy soil from 24.4 to 67.4 and in loamy soil from 37.9 to 102.0. For Meloidogyne spp., %CV ranged from 53.2 to 84.4 and for Pratylenchus spp. from 24.3 to 90.6. The quality of a proficiency test is largely defined by random distribution of the nematodes over the samples allocated, statistical analysis of the data and communication of the results to participating laboratories. This study provides insights into the accuracy and precision at laboratories in recent years and the effect of concerted actions during the period in which the proficiency tests were conducted.


2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Mehmet Demir ◽  
Bülent Güneri

The coracoacromial ligament (CAL), which restrains superior displacement of humeral head, connects the acromion and coracoid process. Due to the ligament’s variations and its role in shoulder pain, CAL was investigated in this study. Sixty shoulders of 34 cadavers, from persons aged 61-98 (80.95 ± 8.81) years at death time, were dissected. The lengths of lateral (LBL) and medial borders (MBL), widths of acromial (AIW) and coracoid insertions (CIW), and thicknesses of lateral (LSTAI) and medial (MSTAI) sides of acromial insertions were measured by digital caliper. The data were subjected to statistical analysis. 24 (40%) V-shaped, 12 (20%) broad-banded, 9 (15%) quadrangular, 9 (15%) Y-shaped, and 6 (10%) multiple-banded types were identified. The mean total LBL, MBL, AIW, CIW, LSTAI, and MSTAI were 34.94 ± 4.59 mm, 33.58 ± 5.31 mm, 29.82 ± 9.48 mm, 12.62 ± 3.95 mm, 1.29 ± 0.17 mm, and 0.90 ± 0.22 mm, respectively. The mean LBL (39.12 ± 4.29 mm), MBL (36.48 ± 3.9 mm), and CIW (37.01 ± 3.39 mm) were significantly greatest in quadrangular type (p<0.001). The mean AIW was slightly greatest in quadrangular type (p=0.069). The mean LSTAI was significantly greatest in multiple-banded type (1.45 ± 0.10 mm, p<0.001) whereas the mean MSTAI was significantly greatest in quadrangular type (1.23 ± 0.23 mm, p<0.001). CAL is quite variable regarding morphology, dimensions, and insertion features. Despite common knowledge, MSTAI and MBL of CAL can be greater than lateral counterparts in some types. To obtain complete release of CAL at acromion, the clearance of ligament fibers in an area with the dimensions of around 16 mm in mediolateral and 15 mm in anteroposterior direction, beginning from the lateral edge of acromial insertion, is recommended.


Sign in / Sign up

Export Citation Format

Share Document