Issues of affinity: Exploring population structure in the middle and regional developments periods of San Pedro de Atacama,Chile

The Middle Period (AD 400–1000) in northern Chile's Atacama oases is characterized by an increase in social complexity and regional interaction, much of which was organized around the power and impact of the Tiwanaku polity. Despite the strong cultural influence of Tiwanaku and numerous other groups evident in interactions with Atacameños, the role of immigration into the oases during this period is unclear. While archaeological and bioarchaeological research in the region has shown no evidence that clearly indicates large groups of foreign immigrants, the contemporary increase in interregional exchange networks connecting the oases to other parts of the Andes suggests residential mobility and the possibility that movement of people both into and out of the oases accompanied these foreign influences. Here, we analyze biodistance through cranial non‐metric traits in a skeletal sample from prehistoric San Pedro de Atacama to elucidate the extent of foreign influence in the oases and discuss its implications. We analyzed 715 individuals from the Middle Period (AD 400–1000) and later Regional Developments Period (AD 1000–1450), and found greater phenotypic differences between Middle Period cemeteries than among cemeteries in the subsequent period. We argue that this greater diversity extends beyond the relationship between the oases and the renowned Tiwanaku polity and reflects the role of the oases and its different ayllus as a node and way station for the Middle Period's myriad interregional networks. Am J Phys Anthropol 152:370–382, 2013. © 2013 Wiley Periodicals, Inc.     

Limited Effect of Three Types of Daily Stress on Rat Free-Running Locomotor Rhythms

The effects of three types of stress/arousal on rat free-running circadian locomotor rhythms in constant darkness were investigated over a 93-day treatment period. Rats were subjected to 30-min daily immobilisation stress or 30-min novelty or to brief handling (n = 10/group). Seven of the 30 rats exhibited some changes in circadian parameters. Three rats (two immobilised, one handling) showed entrainment, three rats (one from each group) showed a change in r, and one rat (novelty) showed a phase advance. Thus, in total, 30% immobilisation, 20% percent novelty, and 20% handled rats showed circadian changes. These group changes paralleled changes in faecal boli and body weight, which were taken as indirect indices of the level of stress. Five of the seven changes took place when the end of the active phase (α), i.e., subjective dawn, coincided with the time of treatment and the other two when the onset of G, i.e., subjective dusk, coincided. Rat circadian locomotor rhythms appear much less susceptible to stress/arousal than those reported for hamsters.     

Induction of PER1 mRNA expression in immortalized gonadotropes by gonadotropin‐releasing hormone (GnRH): Involvement of protein kinase C and MAP kinase signaling

The initiation and maintenance of reproductive function in mammals is critically dependent on the pulsatile secretion of gonadotropin‐releasing hormone (GnRH). This peptide drives the pulsatile release of FSH and LH from the pituitary pars distalis via signaling pathways that are activated by the type I GnRH receptor (GnRH‐R). Recently, a microarray analysis study reported that a number of genes, including mPer1, are induced by GnRH in immortalized gonadotrope cells. In view of these data, we have begun to analyze in detail the signaling pathways mediating the action of GnRH on mPer1 expression in these cells. Using quantitative real‐time polymprose cho read (PCR), we could confirm that exposure of immortalized gonadotropes (LβT2 cells) to the GnRH analog, buserelin, markedly induces mPer1 (but not mPer2) expression. Consistent with GnRH receptor signaling via the protein kinase (PK)‐C pathway, exposure of the cells to phorbol 12,13‐dibutyrate rapidly elevates both mPer1 and LHβ subunit mRNA levels, while pharmacological inhibition of PKC prevents the mPer1 and LHβ response to buserelin. As GnRH is known to regulate gonadotropin synthesis via activation of p42/44 mitogen‐activated protein kinase (MAPK) signaling pathways, we then examined the involvement of this pathway in regulating mPer1 expression in gonadotropes. Our data reveal that GnRH‐induced mPer1 expression is blocked following acute exposure to a MAPK kinase inhibitor. Although the involvement of this signaling mechanism in the regulation of mPer1 is known in neurons, e.g., in the suprachiasmatic nuclei, the induction of mPer1 in gonadotropes represents a novel mechanism of GnRH signaling, whose functional significance is still under investigation.     

Stability of d‐luciferin for bioluminescence to detect gene expression in freely moving mice for long durations

Circadian disturbance of clock gene expression is a risk factor for diseases such as obesity, cancer, and sleep disorders. To study these diseases, it is necessary to monitor and analyze the expression rhythm of clock genes in the whole body for a long duration. The bioluminescent reporter enzyme firefly luciferase and its substrate d ‐luciferin have been used to generate optical signals from tissues in vivo with high sensitivity. However, little information is known about the stability of d ‐luciferin to detect gene expression in living animals for a long duration. In the present study, we examined the stability of a luciferin solution over 21 days. l ‐Luciferin, which is synthesized using racemization of d ‐luciferin, was at high concentrations after 21 days. In addition, we showed that bioluminescence of Period1 (Per1) expression in the liver was significantly decreased compared with the day 1 solution, although locomotor activity rhythm was not affected. These results showed that d ‐luciferin should be applied to the mouse within, at most, 7 days to detect bioluminescence of Per1 gene expression rhythm in vivo.     

On the nature of errors involved in estimating stage-specific survival rates by Southwood's method for a population with overlapping stages

This paper has examined the effect of within-stage mortality on the estimation of stage-specific survival rates bySouthwood's (1978, p. 358) method. As pointed out bySouthwood , both the severity and timing of mortality affect the mean duration of a life stage, and consequently the estimate of the number of individuals entering that stage. Knowledge of the form of the survivorship curve permits correction of the estimate under certain circumstances. The use ofSouthwood's method with two overlapping stages having different rates and patterns of mortality leads to complex errors in the estimation of survival for the first stage. The nature of these errors is examined analytically and via a simulation model.Southwood's method is fairly robust, with moderate differences in mortality rates leading to acceptable errors in estimating survival for the first stage. When both the rate and pattern of mortality in both life stages are the same, then the survival estimate is made without error. Precise estimates of stage-specific survival will not usually be possible withSouthwood's method because of the errors introduced by the very parameters being measured. Direct measurement of mortality rates and survivorship patterns (seeSouthwood , 1978, p. 309) is strongly advised, at least in preliminary work.     

The cycling and distribution of PER-like antigen in relation to neurons recognized by the antisera to PTTH and EH in Thermobia domestica

The cephalic nervous system of the firebrat contains antigens recognized by antisera to the clock protein period (PER), the prothoracicotropic hormone (PTTH) and the eclosion hormone (EH). The content of the 115 kDa PER-like antigen visualized on the western blots fluctuates in diurnal rhythm with a maximum in the night. The oscillations entrained in a 12:12 h light/dark (LD) cycle persist in the darkness and disappear in continuous light. They are detected by immunostaining in 14 pairs of the protocerebral neurons and are extreme in four suboesophageal neurons and two cells in each corpus cardiacum that contain PER only during the night phase. No circadian fluctuations occur in three lightly stained perikarya of the optic lobe. Five cell bodies located in each brain hemisphere between the deuto-and the tritocerebrum retain weak immunoreactivity under constant illumination. In all cells, the staining is confined to the cytoplasm and never occurs in the cell nuclei. The cells containing PER-like material do not react with the anti-PTTH and anti-EH antisera, which recognize antigens of about 50 and 20 kDa, respectively. The anti-PTTH antiserum stains in each brain hemisphere seven neurons in the protocerebrum, eight in the optic lobe, and 3–5 in the posterior region of the deutocerebrum. The antiserum to EH reacts in each hemisphere with just two cells located medially to the mushroom bodies. No cycling of the PTTH-like and EH-like antigens was detected.     

短途运输应激对Wistar大鼠的影响

目的研究短途运输应激对Wistar大鼠的影响,建立评价啮齿类实验动物短途运输应激的技术指标体系。方法采用Wistar大鼠进行短途运输实验,测定其在运输中及运输后各阶段的代谢、神经内分泌和免疫功能主要指标,与未经历运输的对照组比较,分析短途运输应激的影响。结果Wistar大鼠血糖（GLU）在运输0.5 h和1 h时均升高,而在运输1.5 h时降低,运输结束后24 h时GLU再次升高;血清皮质酮（CORT）亦在运输0.5 h和1h时升高而运输1.5 h时降低,但运输结束24 h起即恢复正常;血清β-内啡肽（-βEP）从运输起至运输结束24 h时均降低,至48 h恢复正常。外周白细胞总数（WBC）自运输起急剧减少,于结束运输后的72 h恢复;免疫球蛋白G（IgG）、白介素2（IL-2）、γ干扰素（IFN-γ）及白介素1（IL-1）的血清水平在运输中及运输结束的即刻均没有显著变化,但在结束运输后的48 h内均不同程度降低,至72 h恢复至正常水平。肝脏hsp72 mRNA的表达随着运输时间的延长而极显著上调,运输结束后逐渐恢复,至72 h恢复至正常水平。结论短途运输应激对Wistar大鼠的代谢、神经内分泌和免疫功能均有不利影响,其经历常规短途运输（1.5 h以内）到达目的地后的健康适应期至少应为72 h;外周血中白细胞总数（WBC）、血糖（GLU）、皮质酮（CORT）、β-内啡肽（-βEP）、白介素2（IL-2）的水平可用于系统评价短途运输应激。     

一类具有年龄结构的麦蚜-瓢虫模型的全局分析

研究了一个具有年龄结构的麦蚜-瓢虫模型,其中麦蚜种群被分成两个年龄段,瓢虫种群被分成三个年龄段．应用定性理论可以证明:通过这两个种群的交互作用,可以导致麦蚜种群和瓢虫种群都灭绝或瓢虫种群灭绝,或这两个种群能以正平衡态或振动解的形式共存．通过计算,本文表明这个简单的系统可以产生非常复杂的动力学行为．在这种情形下,要想通过初始值来预测种群的数量是不可能的．应用MATLAB软件,本文展示了这个复杂的动力学行为．