Multiple Diverse Circoviruses Infect Farm Animals and Are Commonly Found in Human and Chimpanzee Feces

Circoviruses are known to infect birds and pigs and can cause a wide range of severe symptoms with significant economic impact. Using viral metagenomics, we identified circovirus-like DNA sequences and characterized 15 circular viral DNA genomes in stool samples from humans in Pakistan, Nigeria, Tunisia, and the United States and from wild chimpanzees. Distinct genomic features and phylogenetic analysis indicate that some viral genomes were part of a previously unrecognized genus in the Circoviridae family we tentatively named “Cyclovirus” whose genetic diversity is comparable to that of all the known species in the Circovirus genus. Circoviridae detection in the stools of U.S. adults was limited to porcine circoviruses which were also found in most U.S. pork products. To determine whether the divergent cycloviruses found in non-U.S. human stools were of dietary origin, we genetically compared them to the cycloviruses in muscle tissue samples of commonly eaten farm animals in Pakistan and Nigeria. Limited genetic overlap between cycloviruses in human stool samples and local cow, goat, sheep, camel, and chicken meat samples indicated that the majority of the 25 Cyclovirus species identified might be human viruses. We show that the genetic diversity of small circular DNA viral genomes in various mammals, including humans, is significantly larger than previously recognized, and frequent exposure through meat consumption and contact with animal or human feces provides ample opportunities for cyclovirus transmission. Determining the role of cycloviruses, found in 7 to 17% of non-U.S. human stools and 3 to 55% of non-U.S. meat samples tested, in both human and animal diseases is now facilitated by knowledge of their genomes.Animal viruses with small, circular, single-stranded DNA (ssDNA) genomes comprise the Circoviridae family and the Anellovirus genus, while viruses in the Geminiviridae and Nanoviridae families infect plants (3, 25, 34, 37, 40). The genomes of these small viruses without a lipid envelope replicate through a rolling-circle mechanism, possibly sharing a common origin with bacterial plasmids (6), and show high recombination and nucleotide substitution rates (7, 19).The Circoviridae family consists of the Circovirus genus whose member species are currently known to infect only birds and pigs, and the Gyrovirus genus, including a single species, Chicken anemia virus (CAV). Circoviruses infect several avian groups, including parrots, pigeons, gulls, anserids (ducks, geese, and swans), and numerous passerines (ravens, canaries, finches, and starlings) (12, 15, 16, 22, 26, 31, 35, 38, 39). Avian circoviruses have been associated with a variety of symptoms, including developmental abnormalities, lymphoid depletion, and immunosuppression (22, 26, 28, 35, 39). Mammalian circoviruses include only two closely related species, Porcine circovirus 1 and 2 (PCV1 and PCV2, respectively), infecting pigs (21). PCV2 has been associated with porcine circovirus-associated diseases, which can manifest as a systemic disease, respiratory disease complex, enteric disease, porcine dermatitis and nephropathy syndrome or as reproductive problems, causing great losses in the pork industry (1, 29, 32). Circovirus infections are thought to occur mainly through fecal-oral transmission (37).We describe here highly diverse, circovirus-like, circular DNA viral genomes discovered in human and chimpanzee stool samples, and we propose their inclusion in a new genus of the Circoviridae family that we tentatively name “Cyclovirus” pending review by the International Committee on Taxonomy of Viruses (ICTV). Cycloviruses were also found to be prevalent in the muscle tissue of farm animals, such as chickens, cows, sheep, goats, and camels. The cyclovirus species found in human stool samples and in animal meat samples showed limited genetic overlap, suggesting that most of the cycloviruses found in human stool samples are not from consumed animal meat. Rather, these cycloviruses in human stools might cause human enteric infections. The presence of cycloviruses in human stool samples and in farm animal tissue also suggests the potential for frequent cross-species exposure and zoonotic transmissions.     

Human Cells Display Reduced Apoptotic Function Relative to Chimpanzee Cells

Previously published gene expression analyses suggested that apoptotic function may be reduced in humans relative to chimpanzees and led to the hypothesis that this difference may contribute to the relatively larger size of the human brain and the increased propensity of humans to develop cancer. In this study, we sought to further test the hypothesis that humans maintain a reduced apoptotic function relative to chimpanzees by conducting a series of apoptotic function assays on human, chimpanzee and macaque primary fibroblastic cells. Human cells consistently displayed significantly reduced apoptotic function relative to the chimpanzee and macaque cells. These results are consistent with earlier findings indicating that apoptotic function is reduced in humans relative to chimpanzees.     

人与大猩猩,黑猩猩和猩猩亲缘关系的探讨

有关人锆超科的系统发育仍然存在刍议。争论焦点在与大猩猩和黑猩猩哪 个关系更近一点。酪氨酸酶是黑色素合成中的关键酶,酪氨酶基因的突变将导致白化病。测定了人猿科中大猩猩,黑猩猩、猩猩和长臂锆产基因全部５个外显子的ＤＮＡ序列。     

Chromosomal Inversions between Human and Chimpanzee Lineages Caused by Retrotransposons

The long interspersed element-1 (LINE-1 or L1) and Alu elements are the most abundant mobile elements comprising 21% and 11% of the human genome, respectively. Since the divergence of human and chimpanzee lineages, these elements have vigorously created chromosomal rearrangements causing genomic difference between humans and chimpanzees by either increasing or decreasing the size of genome. Here, we report an exotic mechanism, retrotransposon recombination-mediated inversion (RRMI), that usually does not alter the amount of genomic material present. Through the comparison of the human and chimpanzee draft genome sequences, we identified 252 inversions whose respective inversion junctions can clearly be characterized. Our results suggest that L1 and Alu elements cause chromosomal inversions by either forming a secondary structure or providing a fragile site for double-strand breaks. The detailed analysis of the inversion breakpoints showed that L1 and Alu elements are responsible for at least 44% of the 252 inversion loci between human and chimpanzee lineages, including 49 RRMI loci. Among them, three RRMI loci inverted exonic regions in known genes, which implicates this mechanism in generating the genomic and phenotypic differences between human and chimpanzee lineages. This study is the first comprehensive analysis of mobile element bases inversion breakpoints between human and chimpanzee lineages, and highlights their role in primate genome evolution.     

Faces in a Crowd: High Socially Anxious Individuals Estimate that More People Are Looking at Them than Low Socially Anxious Individuals

Background

People with social anxiety disorder are afraid of being scrutinized by others and often feel that they are the excessive focus of other people''s attention. This study investigated whether, when compared to low socially anxious individuals, high socially anxious individuals overestimate the proportion of people in a crowd who are observing them. It was hypothesized that any potential overestimation would be modulated by self-focused attention.

Method

Forty-eight high and 48 low socially anxious participants performed a “faces in a crowd” computer task during which they briefly saw matrices of faces, which varied in terms of the proportion of people who were looking at them. Participants estimated the proportion of people who were looking at them. The task was performed once with mirrors present (to induce an enhanced self-focused state) and once without mirrors present (neutral state).

Results

Participants'' subjective estimates and the objective proportion of faces looking towards them were strongly correlated in both the high and low socially anxious groups. However, high socially anxious participants estimated that more people were looking at them than low socially anxious participants. In the first phase of the experiment, but not in the later phases, this effect was magnified in the mirror condition.

Discussion

This study provides preliminary evidence of a social anxiety related perceptual difference that may be amplified by self-focused attention. Clinical implications are discussed.     

Human Wagering Behavior Depends on Opponents' Faces

Research in competitive games has exclusively focused on how opponent models are developed through previous outcomes and how peoples'' decisions relate to normative predictions. Little is known about how rapid impressions of opponents operate and influence behavior in competitive economic situations, although such subjective impressions have been shown to influence cooperative decision-making. This study investigates whether an opponent''s face influences players'' wagering decisions in a zero-sum game with hidden information. Participants made risky choices in a simplified poker task while being presented opponents whose faces differentially correlated with subjective impressions of trust. Surprisingly, we find that threatening face information has little influence on wagering behavior, but faces relaying positive emotional characteristics impact peoples'' decisions. Thus, people took significantly longer and made more mistakes against emotionally positive opponents. Differences in reaction times and percent correct were greatest around the optimal decision boundary, indicating that face information is predominantly used when making decisions during medium-value gambles. Mistakes against emotionally positive opponents resulted from increased folding rates, suggesting that participants may have believed that these opponents were betting with hands of greater value than other opponents. According to these results, the best “poker face” for bluffing may not be a neutral face, but rather a face that contains emotional correlates of trustworthiness. Moreover, it suggests that rapid impressions of an opponent play an important role in competitive games, especially when people have little or no experience with an opponent.     

Faster Increases in Human Life Expectancy Could Lead to Slower Population Aging

Counterintuitively, faster increases in human life expectancy could lead to slower population aging. The conventional view that faster increases in human life expectancy would lead to faster population aging is based on the assumption that people become old at a fixed chronological age. A preferable alternative is to base measures of aging on people’s time left to death, because this is more closely related to the characteristics that are associated with old age. Using this alternative interpretation, we show that faster increases in life expectancy would lead to slower population aging. Among other things, this finding affects the assessment of the speed at which countries will age.     

FR-CAPTCHA: CAPTCHA Based on Recognizing Human Faces

A Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA) is designed to distinguish humans from machines. Most of the existing tests require reading distorted text embedded in a background image. However, many existing CAPTCHAs are either too difficult for humans due to excessive distortions or are trivial for automated algorithms to solve. These CAPTCHAs also suffer from inherent language as well as alphabet dependencies and are not equally convenient for people of different demographics. Therefore, there is a need to devise other Turing tests which can mitigate these challenges. One such test is matching two faces to establish if they belong to the same individual or not. Utilizing face recognition as the Turing test, we propose FR-CAPTCHA based on finding matching pairs of human faces in an image. We observe that, compared to existing implementations, FR-CAPTCHA achieves a human accuracy of 94% and is robust against automated attacks.