Evolution towards oscillation or stability in a predator–prey system

We studied a prey–predator system in which both species evolve. We discuss here the conditions that result in coevolution towards a stable equilibrium or towards oscillations. First, we show that a stable equilibrium or population oscillations with small amplitude is likely to occur if the prey''s (host''s) defence is effective when compared with the predator''s (parasite''s) attacking ability at equilibrium, whereas large-amplitude oscillations are likely if the predator''s (parasite''s) attacking ability exceeds the prey''s (host''s) defensive ability. Second, a stable equilibrium is more likely if the prey''s defensive trait evolves faster than the predator''s attack trait, whereas population oscillations are likely if the predator''s trait evolves faster than that of the prey. Third, when the adaptation rates of both species are similar, the amplitude of the fluctuations in their abundances is small when the adaptation rate is either very slow or very fast, but at an intermediate rate of adaptation the fluctuations have a large amplitude. We also show the case in which the prey''s abundance and trait fluctuate greatly, while those of the predator remain almost unchanged. Our results predict that populations and traits in host–parasite systems are more likely than those in prey–predator systems to show large-amplitude oscillations.     

Men's Preferences for Women's Femininity in Dynamic Cross-Modal Stimuli

Men generally prefer feminine women''s faces and voices over masculine women''s faces and voices, and these cross-modal preferences are positively correlated. Men''s preferences for female facial and vocal femininity have typically been investigated independently by presenting soundless still images separately from audio-only vocal recordings. For the first time ever, we presented men with short video clips in which dynamic faces and voices were simultaneously manipulated in femininity/masculinity. Men preferred feminine men''s faces over masculine men''s faces, and preferred masculine men''s voices over feminine men''s voices. We found that men preferred feminine women''s faces and voices over masculine women''s faces and voices. Men''s attractiveness ratings of both feminine and masculine faces were increased by the addition of vocal femininity. Also, men''s attractiveness ratings of feminine and masculine voices were increased by the addition of facial femininity present in the video. Men''s preferences for vocal and facial femininity were significantly and positively correlated when stimuli were female, but not when they were male. Our findings complement other evidence for cross-modal femininity preferences among male raters, and show that preferences observed in studies using still images and/or independently presented vocal stimuli are also observed when dynamic faces and voices are displayed simultaneously in video format.     

Prenatal and postnatal prevalence of Turner's syndrome: a registry study.

OBJECTIVE--To study prevalence of Turner''s syndrome in Denmark and to assess validity of prenatal diagnosis. DESIGN--Study of data on prenatal and postnatal Turner''s syndrome in Danish Cytogenetic Central Register. SUBJECTS--All registered Turner''s syndrome karyotypes (100 prenatal cases and 215 postnatal cases) during 1970-93. MAIN OUTCOME MEASURES--Prevalence of Turner''s syndrome karyotypes among prenatally tested fetuses and Turner''s syndrome among liveborn infants. RESULTS--Among infant girls, prevalence of Turner''s syndrome was 32/100,000. Among female fetuses tested by amniocentesis, prevalence of Turner''s syndrome karyotypes was 176/100,000 (relative risk of syndrome, 6.74 compared with prevalence among untested pregnancies). Among female fetuses tested by chorion villus sampling, prevalence of syndrome karyotypes was 392/100,000 (relative risk, 16.8). We excluded prenatal tests referred because of results of ultrasound scanning: among fetuses tested by amniocentesis revised relative risk was 5.68, while revised relative risk among fetuses tested by chorion villus sampling was 13.3. For 29 fetuses with prenatal diagnosis of possible Turner''s syndrome, pregnancy was allowed to continue and 24 children were live born. Thirteen of these children were karyotyped postnatally, and diagnosis of Turner''s syndrome had to be revised for eight, seven being normal girls and one boy. This gives tentative predictive value of amniocentesis in diagnosing Turner''s syndrome of between 21% and 67%. There was no significant relation between mother''s age and risk of Turner''s syndrome. CONCLUSIONS--Discrepancy between prenatal and postnatal prevalence of Turner''s syndrome challenges specificity of prenatal examination in diagnosing Turner''s syndrome.     

基于心率检测的便携式儿童情绪感知系统研制

目的:检测儿童的情绪能力,从而检验儿童情绪能力发展是否正常以及协助训练孤独症儿童的情绪能力。方法:设计了一套便携式的儿童情绪感知系统,检测儿童的情绪能力。本系统由心率信号采集模块,PC机端的软件以及情绪能力数据分析组成。结果:研制的儿童情绪能力感知系统具有便携、可穿戴等优点,能够准确地检测儿童情绪能力。结论:儿童情绪能力感知系统能够检测使用者的情绪能力,也能够在儿童情绪能力干预训练中记录孤独症儿童的情绪变化,为干预训练提供帮助。     

Is risk of Kaposi's sarcoma in AIDS patients in Britain increased if sexual partners came from United States or Africa?

OBJECTIVE--To determine whether the risk of Kaposi''s sarcoma in patients with AIDS is increased by sexual contact with groups from abroad with a high incidence of Kaposi''s sarcoma. DESIGN--Analysis of risk of Kaposi''s sarcoma in patients with AIDS, according to country of origin of their sexual partners. SETTING--United Kingdom. PATIENTS--2830 patients with AIDS reported to the Communicable Disease Surveillance Centre and the Communicable Disease (Scotland) Unit up to March 1990, of whom 566 had Kaposi''s sarcoma. MAIN OUTCOME MEASURES--Percentage of patients with AIDS who had Kaposi''s sarcoma. RESULTS--537 of 2291 homosexual or bisexual men (23%) with AIDS had Kaposi''s sarcoma; 10% (14/135) of the men and women who acquired HIV by heterosexual contact had Kaposi''s sarcoma. None of the 316 subjects who acquired HIV through non-sexual routes had Kaposi''s sarcoma. Kaposi''s sarcoma was more common among homosexual men whose likely source of infection included the United States (171/551, 31%) or Africa (9/34, 26%) than among those infected in the United Kingdom (119/625, 19%) (p less than 0.05). CONCLUSION--The data suggest that Kaposi''s sarcoma is caused by a sexually transmissible agent which was introduced into the British homosexual population mainly from the United States [corrected].     

Can male Eurasian jays disengage from their own current desire to feed the female what she wants?

Humans'' predictions of another person''s behaviour are regularly influenced by what they themselves might know or want. In a previous study, we found that male Eurasian jays (Garrulus glandarius) could cater for their female partner''s current desire when sharing food with her. Here, we tested the extent to which the males'' decisions are influenced by their own current desire. When the males'' and female''s desires matched, males correctly shared the food that was desired by both. When the female''s desire differed from their own, the males'' decisions were not entirely driven by their own desires, suggesting that males also took the female''s desire into account. Thus, the male jays'' decisions about their mates'' desires are partially biased by their own desire and might be based upon similar processes as those found in humans.     

Fingerprint Patterns in Huntington's Chorea and Parkinson's Disease

In the course of a continuing search for means of predicting Huntington''s chorea before the onset of neurological symptoms, a study of fingerprint patterns was undertaken, using the technique employed by Hodges and Simon in the investigation of patients with Wilson''s disease. Fingerprint patterns of 61 patients with Huntington''s chorea and 50 with Parkinson''s disease were compared with norms established by Scotland Yard. Although an increased incidence of the “whorl” pattern was seen in the left second and third fingers in patients with Huntington''s chorea, this finding could not be interpreted as having diagnostic or prognostic value as it was found also in some normal subjects and in occasional cases of Parkinson''s disease. The pattern supposedly characteristic of Wilson''s disease was also seen in persons with Huntington''s chorea.     

Crohn's disease of the appendix

Granulomatous inflammation typifying Crohn''s disease was centred within or confined to appendices in six patients, two of whom developed lesions attributable to Crohn''s disease elsewhere in the gut. The remaining four patients have remained symptom-free for periods varying from two to six years. Histological evidence of Crohn''s disease was also present in five of 46 appendices available for re-examination in a survey of 63 cases of Crohn''s enterocolitis. It is adduced that appendiceal involvement in Crohn''s disease is not uncommon.     

The Manifestation of Chromosome Rearrangements in Unordered Asci of Neurospora

Rapid, effective techniques have been developed for detecting and characterizing chromosome aberrations in Neurospora by visual inspection of ascospores and asci. Rearrangements that are detectable by the presence of deficient, nonblack ascospores in test crosses make up 5 to 10% of survivors after UV doses giving 10-55% survival. Over 135 rearrangements have been diagnosed by classifying unordered asci according to numbers of defective spores. (These include 15 originally identified or analyzed by other workers.) About 100 reciprocal translocations (RT''s) have been confirmed and mapped genetically, involving all combinations of the seven chromosomes. Thirty-three other rearrangements generate viable nontandem duplications in meiosis. These consist of insertional translocations (IT''s) (15 confirmed), and of rearrangements that involve a chromosome tip (10 translocations and 3 pericentric inversions). No inversion has been found that does not include the centromere. A reciprocal translocation was found within one population in nature. When pairs of RT''s that involve the same two chromosome arms were intercrossed, viable duplications were produced if the breakpoints overlapped in such a way that pairing resembled that of insertional translocations (27 combinations).—The rapid analytical technique depends on the following. Deficiency ascospores are usually nonblack (W: "white") and inviable, while nondeficient ascospores, even those that include duplications, are black (B) and viable. Thus RT''s typically produce 50% black spores, and IT''s 75% black. Asci are shot spontaneously from ripe perithecia, and can be collected in large numbers as groups of eight ascospores representing unordered tetrads, which fall into five classes: 8B:0W; 6B:2W, 4B:4W, 2B:6B, 0B:8W. In isosequential crosses, 90-95% of tetrads are 8:0. When a rearrangement is heterozygous, the frequencies of tetrad classes are diagnostic of the type of rearrangement, and provide information also on the positions of break points. With RT''s, 8:0 (alternate centromere segregation) = 0:8 (adjacent-1), 4:4''s require interstitial crossing over in a centromere-break point interval, and no 6:2''s or 2:6''s are expected. With IT''s, duplications are viable, 8:0 = 4:4, 6:2''s are from interstitial crossing over, 0:8''s or 2:6''s are rare. Tetrads from RT''s that involve a chromosome tip resemble those from IT''s, as do tetrads from intercrosses between partially overlapping RT''s that involve identical chromosome arms.—Because viable duplications and other aneuploid derivatives regularly occur among the offspring of rearrangements such as insertional translocations, care must be taken in selecting stocks, and original strains should be kept for reference.     

Zipf's law leads to Heaps' law: analyzing their relation in finite-size systems

Background

Zipf''s law and Heaps'' law are observed in disparate complex systems. Of particular interests, these two laws often appear together. Many theoretical models and analyses are performed to understand their co-occurrence in real systems, but it still lacks a clear picture about their relation.

Methodology/Principal Findings

We show that the Heaps'' law can be considered as a derivative phenomenon if the system obeys the Zipf''s law. Furthermore, we refine the known approximate solution of the Heaps'' exponent provided the Zipf''s exponent. We show that the approximate solution is indeed an asymptotic solution for infinite systems, while in the finite-size system the Heaps'' exponent is sensitive to the system size. Extensive empirical analysis on tens of disparate systems demonstrates that our refined results can better capture the relation between the Zipf''s and Heaps'' exponents.

Conclusions/Significance

The present analysis provides a clear picture about the relation between the Zipf''s law and Heaps'' law without the help of any specific stochastic model, namely the Heaps'' law is indeed a derivative phenomenon from the Zipf''s law. The presented numerical method gives considerably better estimation of the Heaps'' exponent given the Zipf''s exponent and the system size. Our analysis provides some insights and implications of real complex systems. For example, one can naturally obtained a better explanation of the accelerated growth of scale-free networks.     

Accidental Outcomes Guide Punishment in a “Trembling Hand” Game

How do people respond to others'' accidental behaviors? Reward and punishment for an accident might depend on the actor''s intentions, or instead on the unintended outcomes she brings about. Yet, existing paradigms in experimental economics do not include the possibility of accidental monetary allocations. We explore the balance of outcomes and intentions in a two-player economic game where monetary allocations are made with a “trembling hand”: that is, intentions and outcomes are sometimes mismatched. Player 1 allocates $10 between herself and Player 2 by rolling one of three dice. One die has a high probability of a selfish outcome, another has a high probability of a fair outcome, and the third has a high probability of a generous outcome. Based on Player 1''s choice of die, Player 2 can infer her intentions. However, any of the three die can yield any of the three possible outcomes. Player 2 is given the opportunity to respond to Player 1''s allocation by adding to or subtracting from Player 1''s payoff. We find that Player 2''s responses are influenced substantially by the accidental outcome of Player 1''s roll of the die. Comparison to control conditions suggests that in contexts where the allocation is at least partially under the control of Player 1, Player 2 will punish Player 1 accountable for unintentional negative outcomes. In addition, Player 2''s responses are influenced by Player 1''s intention. However, Player 2 tends to modulate his responses substantially more for selfish intentions than for generous intentions. This novel economic game provides new insight into the psychological mechanisms underlying social preferences for fairness and retribution.     

我国农户生计转型的生态效应研究综述

生计作为人类最主要的行为方式,对人地系统的演化起着主导驱动作用,探讨人类生计与生态环境的相互关系成为当前人地系统科学的研究热点,农户作为广大农村最主要的经济活动主体与最基本的决策单位,其所采取的生计策略对生态环境产生着深远影响。在阐释农户生计转型及其驱动因素的基础上,建立了农户生计转型的生态效应分析框架,梳理了近年来国内农户生计转型的生态效应研究主要进展,指出未来研究中需关注农户的生计演变规律及其调控机制、农户生计策略对生态环境的作用机制、农户生计转型的生态效应评估与监测、农户的可持续生计方式塑建等关键问题。     

Children's Hospital Admissions and Mother's Menstruation

Of 100 children''s emergency admissions to hospital nearly half (49%) were admitted during the mother''s paramenstruum. There was a statistically significant association between the mother''s menstruation and the child''s admission both for accidents and for illnesses. The eldest child in the family appeared to be most affected.     

基于专利分析的肿瘤基因PCR诊断技术研究

肿瘤目前成为人类健康和生命的重要危胁,肿瘤基因诊断是对肿瘤的各种原癌基因、抑癌基因进行检测,聚合酶链反应(polymerase chain reaction,PCR)技术是目前临床基因诊断应用最广泛的诊断技术,具有普及率高、特异性好、简便快捷等特点。肿瘤基因PCR诊断技术可以用于已知基因突变的检测,快速了解突变状态,有效制定治疗方案,为肿瘤患者带来福音。本研究主要基于专利数据,对肿瘤基因PCR诊断技术进行分析,探讨了全球与中国在肿瘤基因PCR诊断技术领域的发展现状与趋势。在Innography数据库共检索到PCR技术相关专利16,939件,专利家族6,285件。在肿瘤基因PCR诊断技术领域中,荧光定量PCR技术占比较大,约占肿瘤基因PCR诊断技术总量的三分之一。从技术技术生命周期来看,肿瘤基因PCR诊断技术目前仍处在高速发展阶段。美国是肿瘤基因PCR诊断技术的发展领先国家。该技术的主要来源国为美国,全球42.09%的专利来自美国,同时美国也是同族专利的主要分布地区。在肿瘤基因PCR诊断技术领域,排名前15位的顶尖机构中,来自美国的机构有7所。中国在肿瘤基因PCR诊断技术领域起步较晚,但发展迅速,在该技术领域申请的专利数量仅次于美国。中国申请的肿瘤基因PCR诊断技术的专利绝大多数都只在中国进行专利保护,并没有布局全球市场的意愿。     

NON-INFECTIOUS INFLAMMATORY AND NEOPLASTIC DISORDERS OF THE MALE GENITALIA

The cutaneous manifestations of the male external genitalia are difficult to diagnose. They may be associated with systemic disease (Reiter''s disease, psoriatic arthritis, angiokeratoma corporis diffusum). In dealing with a lesion of this area that does not heal, adequate biopsy is advisable to rule out malignant disease (Bowen''s disease, melanoma, Kaposi''s sarcoma, Paget''s disease, erythroplasia).     

Addison,pernicious anemia and adrenal insufficiency

In 1849 Thomas Addison described the clinical entity now known as pernicious anemia. In 1855 he reported several cases of adrenal insufficiency, or Addison''s disease. Considering the importance of these works, there remains a great deal of confusion about them. Contrary to what many historians have written, a review of Addison''s original publications demonstrates a firm appreciation of the distinction between pernicious anemia and adrenal insufficiency, based particularly on the discoloration of the skin in these conditions. Three major sources of possible confusion for historians who are attempting to understand Addison''s views include Addison''s early attempts to link pernicious anemia with disease of the supra-renal capsules, Addison''s redefinition of pernicious anemia in his monograph on adrenal disease, and several confusing statements made by Wilks and Daldy in the first reprint of Addison''s monograph.     

Nurse Practitioner and Physician's Assistant Clinics in Rural California: Part I: Issues

The primary health care needs of at least 26 rural California communities are being served by nurse practitioners (NP''s) or physician''s assistants (PA''s). All of these have physician supervision and support. NP''s and PA''s have proved to be acceptable and effective. With 230 rural areas in California identified as having unmet health care needs, this type of service is likely to increase and should be supported.NP/PA clinics serve total populations or concentrate on Indians, Chicanos or the poor. Many barriers have been overcome, especially over the past four years, to allow these clinics to flourish and increase in number. The availability of nurse practitioners and physician''s assistants has increased due to support to schools and to school policies. Clinic funding has greatly improved; federal funds for general rural clinics, Indians, migrants, family planning and maternalchild health have been greatly supplemented by California state funds. Beginning in 1978, rural NP and PA services can be reimbursed by Medicare and Medi-Cal (California''s Medicaid program).Since 1975 state laws have defined PA and NP roles broadly, and these roles are more precisely defined at the local level. Although nurse practitioners and physician''s assistants generally cannot prescribe or dispense drugs (a major problem in many clinics), demonstration legislation allows special pilot projects to do both. As remaining funding and legal problems are corrected, NP''s and PA''s will serve an even greater role in rural areas.     

Spectinomycin resistant gonococci.

A study was conducted examining the properties of 10 clinical isolates of spectinomycin resistant gonococci from patients attending clinics at St Mary''s and St Thomas''s Hospitals, London. All of the isolates produced beta-lactamase and contained plasmids of 2.6, 4.4, and 24.5 megadaltons and required proline for growth. None produced aminoglycoside modifying enzymes. Resistance to spectinomycin was transferred from some of the isolates by transformation but at a much lower frequency than resistance to streptomycin. The isolates from St Mary''s Hospital were detected after therapy with spectinomycin, whereas those from St Thomas''s Hospital were not. Four recent non-beta-lactamase producing gonococci isolated at St Mary''s Hospital and two isolated at St Thomas''s Hospital also were not related to use of spectinomycin.     

甘孜藏族自治州生态系统生产总值核算研究

甘孜藏族自治州(以下简称甘孜州)生态状况良好而经济相对滞后,评估甘孜州生态系统服务功能及其价值,对甘孜州社会经济的可持续发展具有一定的促进作用。通过核算甘孜州的生态系统生产总值(GEP),包括对甘孜州的产品提供服务、调节服务和文化服务进行价值评估,以期用直观的经济数据揭示甘孜州生态系统对人们的直接贡献。核算结果显示,甘孜州2010年全州生态系统生产总值(GEP)为7545.59亿元,人均71.18万元,是当年该州国内生产总值(GDP)和人均GDP的约61倍。其中,调节服务的价值最大,为6842.28亿元,占GEP总值的90.68%;产品提供服务和文化服务的价值分别为632.64亿元和70.67亿元,占GEP的8.38%和0.94%。研究认为甘孜州生态系统服务功能价值巨大,保护甘孜州生态系统就是保护人们的福祉,该结果可以为甘孜州的生态系统管理、生态保护和生态补偿提供重要依据。     

Mother-to-Infant Transmission of Intestinal Bifidobacterial Strains Has an Impact on the Early Development of Vaginally Delivered Infant's Microbiota

Objectives

Bifidobacterium species are one of the major components of the infant''s intestine microbiota. Colonization with bifidobacteria in early infancy is suggested to be important for health in later life. However, information remains limited regarding the source of these microbes. Here, we investigated whether specific strains of bifidobacteria in the maternal intestinal flora are transmitted to their infant''s intestine.

Materials and Methods

Fecal samples were collected from healthy 17 mother and infant pairs (Vaginal delivery: 12; Cesarean section delivery: 5). Mother''s feces were collected twice before delivery. Infant''s feces were collected at 0 (meconium), 3, 7, 30, 90 days after birth. Bifidobacteria isolated from feces were genotyped by multilocus sequencing typing, and the transitions of bifidobacteria counts in infant''s feces were analyzed by quantitative real-time PCR.

Results

Stains belonging to Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium catenulatum, Bifidobacterium longum subsp. longum, and Bifidobacterium pseudocatenulatum, were identified to be monophyletic between mother''s and infant''s intestine. Eleven out of 12 vaginal delivered infants carried at least one monophyletic strain. The bifidobacterial counts of the species to which the monophyletic strains belong, increased predominantly in the infant''s intestine within 3 days after birth. Among infants delivered by C-section, monophyletic strains were not observed. Moreover, the bifidobacterial counts were significantly lower than the vaginal delivered infants until 7 days of age.

Conclusions

Among infants born vaginally, several Bifidobacterium strains transmit from the mother and colonize the infant''s intestine shortly after birth. Our data suggest that the mother''s intestine is an important source for the vaginal delivered infant''s intestinal microbiota.