State and Trait Olfactory Markers of Major Depression

Nowadays, depression is a major issue in public health. Because of the partial overlap between the brain structures involved in depression, olfaction and emotion, the study of olfactory function could be a relevant way to find specific cognitive markers of depression. This study aims at determining whether the olfactory impairments are state or trait markers of major depressive episode (MDE) through the study of the olfactory parameters involving the central olfactory pathway. In a pilot study, we evaluated prospectively 18 depressed patients during acute episodes of depression and 6 weeks after antidepressant treatment (escitalopram) against 54 healthy volunteers, matched by age, gender and smoking status. We investigated the participants’ abilities to identify odors (single odors and in binary mixture), to evaluate and discriminate the odors’ intensity, and determine the hedonic valence of odors. The results revealed an “olfactory anhedonia” expressed by decrease of hedonic score for high emotional odorant as potential state marker of MDE. Moreover, these patients experienced an “olfactory negative alliesthesia”, during the odor intensity evaluation, and failed to identify correctly two odorants with opposite valences in a binary iso-mixture, which constitute potential trait markers of the disease. This study provides preliminary evidence for olfactory impairments associated with MDE (state marker) that are persistent after the clinical improvement of depressive symptoms (trait marker). These results could be explained by the chronicity of depression and/or by the impact of therapeutic means used (antidepressant treatment). They need to be confirmed particularly the ones obtained in complex olfactory environment which corresponds a more objective daily life situation.     

The Polyploid State Plays a Tumor-Suppressive Role in the Liver

1. Download high-res image (259KB)
2. Download full-size image

     

Fluctuating Asymmetry and Environmental Stress: Understanding the Role of Trait History

While fluctuating asymmetry (FA; small, random deviations from perfect symmetry in bilaterally symmetrical traits) is widely regarded as a proxy for environmental and genetic stress effects, empirical associations between FA and stress are often weak or heterogeneous among traits. A conceptually important source of heterogeneity in relationships with FA is variation in the selection history of the trait(s) under study, i.e. traits that experienced a (recent) history of directional change are predicted to be developmentally less stable, potentially through the loss of canalizing modifiers. Here we applied X-ray photography on museum specimens and live captures to test to what extent the magnitude of FA and FA-stress relationships covary with directional shifts in traits related to the flight apparatus of four East-African rainforest birds that underwent recent shifts in habitat quality and landscape connectivity. Both the magnitude and direction of phenotypic change varied among species, with some traits increasing in size while others decreased or maintained their original size. In three of the four species, traits that underwent larger directional changes were less strongly buffered against random perturbations during their development, and traits that increased in size over time developed more asymmetrically than those that decreased. As we believe that spurious relationships due to biased comparisons of historic (museum specimens) and current (field captures) samples can be ruled out, these results support the largely untested hypothesis that directional shifts may increase the sensitivity of developing traits to random perturbations of environmental or genetic origin.     

几种新优水生花卉的观赏和利用

本文对几种目前使用于园林水景绿化中的新优水生花卉的形态、观赏和利用价值作了一些评述,为进一步发掘、开发和利用提供依据.     

The Role of Resting State Networks in Focal Neocortical Seizures

Objective

The role of resting state functional networks in epilepsy is incompletely understood. While some pathologic diagnoses have been shown to have maintained but altered resting state connectivity, others have implicated resting state connectivity in disease progression. However little is known about how these resting state networks influence the behavior of a focal neocortical seizure.

Methods

Using data taken from invasively monitored patients with intractable focal neocortical epilepsy, we evaluated network connectivity (as determined by oscillatory covariance of the slow cortical potential (<0.5 Hz)) as it relates to neocortical seizure foci both in the interictal and ictal states.

Results

Similar to what has been shown in the past for sleep and anesthesia, electophysiologic resting state networks that are defined by this slow cortical potential covariance maintain their topographic correlation structure throughout an ictal event. Moreover, in the context of focal epilepsy in which the seizure has a specific site of onset, seizure propagation is not chaotic or random. Rather, the seizure (reflected by an elevation of high frequency power) preferentially propagates along the network that contains the seizure onset zone.

Significance

Taken together, these findings further undergird the fundamental role of resting state networks, provide novel insights into the network-influenced behavior of seizures, and potentially identify additional targets for surgical disconnection including informing the location for the completion of multiple subpial transections (MSPTs).     

The Role of Transmembrane Electrical Potential in Determining the Absorption Isotherm for Chloride in Potato

Measurements have been made of the electrical potential differencebetween the vacuoles of single potato tuber cells and externalCl^- solutions over the range 1–40 mM. With K⁺ as the counter-ion,the relationship between this transmembrane electrical potentialand external Cl^- concentration, for fresh cells at 20° C,was found to be one of decreasing negative polarity with increasingCl^- concentration (E at 1 mM Cl^- external = – 81 m V;change in E for a 10-fold change in external concentration,E₁₀ = 46 m V). The linearity of this relationship, apparenton a semi-logarithmic plot, was virtually unaltered by low temperature(0.5–2.5° C) or by previous ageing of the cells forperiods up to four days (indicating that metabolic ion absorptionis not an electrogenic process). When the counter-ion was maintainedat a constant high concentration (40 mM K⁺), the change in potentialover the Cl^- concentration range was only 4 m V, polarity becomingmore negative with increasing Cl^- concentration. With Ca⁺⁺ asthe counter-ion, the potential to external Cl^- concentrationrelationship was similar to that found in KCl solutions, exceptthat E₁₀ was only about 20 m V. Curves for the influx of C1^- to be expected on the basis ofthese electrochemical data alone have been shown to run closelyparallel to Cl^– absorption isotherms previously determinedexperimentally. This confirms the opinion, already formed onthe basis of theoretically derived values for passive Cl^- influx,that Cl^- uptake by both fresh and one-day-aged potato tissue,from KCl solutions and Cl^- solutions with a fixed high K⁺ concentration,is rate-determined at o° C by passive movement across theplasmalemma. Uptake of Cl^- by fresh tissue at 20° C appearsto be similarly regulated. No such parallelism was found between observed and expectedpatterns of Cl^- uptake from CaCl₂ solutions, or from KCl bytwo-day-aged tissue, and here factors in addition to the electrochemicalones must determine low temperature Cl^-uptake.     

Cdk6在维持ES细胞自我更新中的作用

细胞周期蛋白依赖性激酶6（cyclin dependent kinase 6,Cdk6）对胚胎早期发育有着重要的作用.然而,它在胚胎干（embryonic stem,ES）细胞中的生物学功能仍不清楚.在该研究中,我们运用RNA干扰技术和基因表达分析方法探索了Cdk6在小鼠胚胎干细胞中的功能及分子机制.结果表明：Cdk6的表达水平与小鼠ES细胞的自我更新密切相关.首先,维甲酸（RA）处理和白血病抑制因子（LIF）去除实验显示 ,随着ES细胞的分化,Cdk6的表达水平明显降低.更为重要的是,RNA干扰介导的Cdk6表达抑制导致ES细胞自我更新相关基因的显著下调,同时伴随细胞分化基因的表达激活,提示Cdk6对维持ES细胞自我更新至关重要.     

The Vital Role of Non-Flag State Actors in the Pursuit of Safer Shipping

Abstract

If fishery resources are to be properly managed, decision makers must be provided with good scientific advice. Most countries do not at present have the capacities to provide this advice without assistance. The steps required to make this advice available include a proper choice of institutional arrangements, identification of priorities (in which collection of data ranks high), attraction of scientists into the fishery field and their subsequent training in specialized fishery subjects, and closer cooperation between countries interested in the same resource. Some forms that this training and regional cooperation could take are discussed. There are particular problems for small countries (whether developed or not) who in the foreseeable future cannot build up a large‐scale multidisciplinary fishery‐research institute, but yet require scientific advice on important national fisheries.     

地黄对于糖尿病大鼠微炎症状态的作用

目的:研究地黄对于糖尿病模型大鼠血糖以及微炎症状态的作用。方法:采用高糖高脂饲料喂养加腹腔注射链尿佐菌素(STZ)破坏胰岛细胞的方法构建糖尿病大鼠模型。将大鼠分为空白对照组、糖尿病模型组与药物治疗组。空白对照组以及糖尿病模型组给予蒸馏水,用药组分别给予不同剂量丹参、地黄、格列本脲灌胃治疗,每日一次,连续60日。应用血糖仪动态监测血糖,ELISA法检测血清中超敏C反应蛋白(Hs-CRP)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)浓度变化情况,以观察地黄对血糖及糖尿病微炎症状态的改善效果。结果:造模成功后,糖尿病大鼠血糖明显升高(P0.05),血液中炎症因子Hs-CRP、IL-6、TNF-α含量升高,与空白对照组相比,差异显著(P0.05)。地黄治疗后血糖明显降低(P0.05),血液中炎症因子Hs-CRP、IL-6、TNF-α含量均显著减低,差异均有统计学意义(P0.05)。结论:地黄可以明显降低糖尿病大鼠的血糖水平,显著改善糖尿病大鼠的微炎症状态。     

The Role of Iron and Dissolved Organic Carbon in the Absorption of Ultraviolet Radiation in Humic Lake Water

Absorption of solar ultraviolet radiation (UVR) in aquatic ecosystems is primarily controlled by dissolved organic carbon (DOC). The role of iron (Fe) has also been suggested to contribute to UVR attenuation either directly or by interactions with DOC. Here we present findings from three laboratory manipulations of Fe and DOC on changes to the dissolved UVR absorption (a_d,320) in a mid-latitude, dimictic, humic lake. In a laboratory simulation of lake turnover where anoxic, hypolimnetic water was oxygenated a_d,320 significantly increased from 23.3 to 81.7 m⁻¹ (p<0.0001). In a second laboratory experiment, addition of ferrous Fe to deoxygenated lake water increased a_d,320 upon reoxygenation up to a concentration of 1.0 mg l⁻¹ Fe, where a solubility saturation threshold may have been reached. In situ lake experiments were designed to simulate release of UV absorbing substances from anoxic sediments by placing 20-l carboys (open at the bottom, sealed at the top) onto the lake bottom. UV absorption at 320 nm increased over time for samples from within the experimental carboys. Finally, samples from several lake profiles and sediment experiments were analyzed for a_d,320, total Fe, and DOC. UV absorption of dissolved substances at 320 nm and total Fe concentration both increased with depth, however DOC remained relatively constant over depth. Furthermore, total Fe and spectral slope showed tight coupling up to 1 mg l⁻¹ total Fe in our survey analysis. Our results provide evidence for the importance of anoxic sediments as a source of ferrous iron and UV absorbing substances and suggest a role for ferric iron in increasing UVR and PAR absorption in lake water. We suggest that as this ferrous Fe oxidizes, its absorptive properties increase, and it may bind with dissolved organic matter, enabling it to remain in solution and thus increasing the dissolved absorption of lake water for extended periods of time.     

Aftercare of State Hospital Patients—The Role of the General Practitioner

Of all the problems facing patients released from a state hospital, the most serious one is adjustment. Failure here means a return to the hospital. The present aftercare program of the Department of Mental Hygiene does not and is not intended to meet all of the patient''s needs. It must rely upon other agencies to assist. It must rely upon the general practitioner to provide the continuity of care which is so important to successful rehabilitation.The general practitioner can often make return to a state hospital unnecessary by an accurate assessment of the patient''s problems, by effective intervention, by utilizing available consultation and by judicious referral. When services are not available, he can do much to make them available through the effective use of his professional channels.     

The Role of the Initial State in the Response of the Hemostasis System to Double Exercise

Changes in the hemostasis system were studied in males with a high working capacity when they performed the same dosed double stress exercise test with moderate (N ₁ = 1.4 W/kg, t ₁ = 6.93 min) and high (N ₂ = 2.96 W/kg, t ₂ = 3.15 min) intensity with a 1-h interval between. The direction and the magnitude of changes in the main variables of blood coagulation, anticoagulants, and blood and plasma fibrinolytic activity under the influence of exercise were shown to correlate with the initial state of the system. At high values of the variables before the beginning of muscular activity, work results in their decrease, and at low values, in their increase. Previous work increases the dependence of changes in blood coagulation on its initial value upon repeat exercise, without influencing the relationship between alterations in the fibrinolytic activity of whole blood and its value before exercise. Double loading reveals closer relations between the initial values of blood coagulation, anticoagulants, and fibrinolysis and their changes due to work. It was concluded that, on the basis of the correlations presented, it is possible to predict with high probability the direction and the magnitude of hemocoagulant and fibrinolytic response to physical activity in the group of subjects studied.     

The Role of State Departments of Education in Complex School Reform.

The Role of State Departments of Education in Complex School Reform. Susan Lusi. New York: Teachers College Press, 1997. 217 pp.     

Role of Gastrointestinal Microflora in the Mineral Absorption of Young Adult Mice

A comparison between germfree (GF) and gnotobiotic (GB) mice, inoculated with Bacteroides vulgatus, Eubacterium aerofaciens, Bifidobacterium longum, Enterococcus faecalis, Escherichia coli, and Clostridium perfringens, revealed that the GB mice suffered no deleterious effect on the apparent absorption ratios of Ca and P, and showed a higher apparent absorption ratio of Mg.     

Influences of State and Trait Affect on Behavior,Feedback-Related Negativity,and P3b in the Ultimatum Game

The present study investigates how different emotions can alter social bargaining behavior. An important paradigm to study social bargaining is the Ultimatum Game. There, a proposer gets a pot of money and has to offer part of it to a responder. If the responder accepts, both players get the money as proposed by the proposer. If he rejects, none of the players gets anything. Rational choice models would predict that responders accept all offers above 0. However, evidence shows that responders typically reject a large proportion of all unfair offers. We analyzed participants’ behavior when they played the Ultimatum Game as responders and simultaneously collected electroencephalogram data in order to quantify the feedback-related negativity and P3b components. We induced state affect (momentarily emotions unrelated to the task) via short movie clips and measured trait affect (longer-lasting emotional dispositions) via questionnaires. State happiness led to increased acceptance rates of very unfair offers. Regarding neurophysiology, we found that unfair offers elicited larger feedback-related negativity amplitudes than fair offers. Additionally, an interaction of state and trait affect occurred: high trait negative affect (subsuming a variety of aversive mood states) led to increased feedback-related negativity amplitudes when participants were in an angry mood, but not if they currently experienced fear or happiness. We discuss that increased rumination might be responsible for this result, which might not occur, however, when people experience happiness or fear. Apart from that, we found that fair offers elicited larger P3b components than unfair offers, which might reflect increased pleasure in response to fair offers. Moreover, high trait negative affect was associated with decreased P3b amplitudes, potentially reflecting decreased motivation to engage in activities. We discuss implications of our results in the light of theories and research on depression and anxiety.