Quantifying Significance of Topographical Similarities of Disease-Related Brain Metabolic Patterns

Multivariate analytical routines have become increasingly popular in the study of cerebral function in health and in disease states. Spatial covariance analysis of functional neuroimaging data has been used to identify and validate characteristic topographies associated with specific brain disorders. Voxel-wise correlations can be used to assess similarities and differences that exist between covariance topographies. While the magnitude of the resulting topographical correlations is critical, statistical significance can be difficult to determine in the setting of large data vectors (comprised of over 100,000 voxel weights) and substantial autocorrelation effects. Here, we propose a novel method to determine the p-value of such correlations using pseudo-random network simulations.     

Analgesic Nephropathy. Clinical Course after Withdrawal of Phenacetin

Of 14 patients with analgesic nephropathy 11 were followed up for 9 to 88 (mean 36) months after withdrawal of analgesics containing phenacetin. Ten of these 11 are still alive and have improving, static, or very slowly declining renal function. Analgesic withdrawal is therefore worth achieving even in the presence of advanced renal failure. Careful prolonged follow-up is required to prevent or detect relapse and to deal with the complications of prolonged renal failure, particularly bone disease and acidosis.Early diagnosis is life-saving in this condition. Attention is drawn to the diagnostic value of sterile pyuria, but the best screening test for the condition is careful interrogation of all patients with chronic renal disease of unknown aetiology; analgesic intake is rarely denied if asked for specifically.     

血清C-反应蛋白(CRP)测定报告

通过２８４９例患者血清Ｃ－反应蛋白（ＣＲＰ）检测证实,ＣＲＰ是细菌性感染的重要指标,败血症增高率达９１．６％,肺炎为４８％,其它细菌感染性疾病也均有不同程度的增高,而病毒性心肌炎则不增高。ＣＲＰ是诊断恶性肿瘤的重要指标之一,在恶网、肝癌、膀胱癌中均为１００％增高,而肺癌增高率为６６．６％。ＣＲＰ在风湿病活动期很敏感,故用于诊断活动性ＲＡ、ＳＬＥ极有意义,ＣＲＰ也可作为白血病继发感染的诊断及急性组织损伤的可靠证据     

新生儿抚触及其临床意义

目的：探讨抚触对新生儿发育的影响。方法：将180例新生儿随机分为抚触组91例和对照组89例。分别测量、观察新生儿摄入奶量与体重、胎便转黄时间、生理性黄疸开始消退时间、完全消退时间及睡眠时间。结果：抚触组新生儿的摄入奶量与体重均增加,胎便转黄时间、生理性黄疸开始消退时间、完全消退时间均减少,睡眠时间延长,两组新生儿在摄入奶量、体重、胎便初排时间及胎便转黄时间、新生儿生理性黄疸开始消退和完全消退时间、睡眠时间均有明显差异（P〈0.05）。结论：抚触对促进新生儿身心的健康发育有明显效果。     

Significance of Staphylococcus epidermidis in the Clinical Laboratory

Susceptibility to 11 antibiotics was determined for 63 cultures of Staphylococcus aureus and 63 cultures of Staphylococcus epidermidis obtained at random from the clinical laboratory. The incidence of resistance to nine of these antibiotics was greater for S. epidermidis than for S. aureus. Studies of the minimal inhibitory concentration of these cultures to clindamycin showed that 61 cultures of S. aureus were susceptible whereas only 46 cultures of S. epidermidis were susceptible to this antibiotic. Although cultures of S. aureus were more active in the production of seven virulence factors, some cultures of S. epidermidis produced virulence factors. By successive cultivation in increasing concentrations of clindamycin, resistant variants were obtained for 10 cultures of S. aureus and 3 cultures of S. epidermidis. The presence of subinhibitory concentrations of clindamycin inhibited the production of some virulence factors by the resistant variants. In view of the greater resistance of S. epidermidis to antibiotics and its ability to produce virulence factors, its isolation in the clinical laboratory should not be regarded lightly.     

Quantifying the geometry of micropipets

Accurate knowledge of the internal diameter (id) of micropipet tips is important, because the ability to study many different aspects of biological membranes is a very sensitive function of tip size. The authors examined two methods used to characterize pipet tips: the digital manometric method (DMM) and bubble number method (BNM). For DMM, the authors compared the ability of Laplace's equation (model I) and a modified form of his equation (model II), which accounts for adhesion between the test fluid and glass Pressure measurements were made with a digital manometer, and ids at the tip were measured using scanning electron microscopy (SEM). The micropipet tips showed a slight asymmetry in id, with a approx 5% difference between maximum and minimum id. On average, model I overestimates the largest id by 2%. Model II overestimates the smaller id by 2%. For micropipet tips ranging from 1.00 to 5.00 μm, the corresponding uncertainties range from 20 to 100 nm. Making the normally hydrophilic glass surface hydrophobic strongly reduced threshold pressures when tested in water, but not 100% methanol. Compared to BNM, DMM was insensitive to changes in atmospheric pressure: BNM can be corrected for changes in atmospheric pressure. Convergence angle(s) can be determined from measurements of the pressure and the axial distance of the meniscus from the tip. The accuracy and precision of digital manometry approaches that of SEM. DMM should be particularly useful in selecting, micropipets for patch clamp studies of small vesicles (<10 μm), and may enable systematic selection of micropipets for many other experiments.     

Quantifying the Shape of Aging

In Biodemography, aging is typically measured and compared based on aging rates. We argue that this approach may be misleading, because it confounds the time aspect with the mere change aspect of aging. To disentangle these aspects, here we utilize a time-standardized framework and, instead of aging rates, suggest the shape of aging as a novel and valuable alternative concept for comparative aging research. The concept of shape captures the direction and degree of change in the force of mortality over age, which—on a demographic level—reflects aging. We 1) provide a list of shape properties that are desirable from a theoretical perspective, 2) suggest several demographically meaningful and non-parametric candidate measures to quantify shape, and 3) evaluate performance of these measures based on the list of properties as well as based on an illustrative analysis of a simple dataset. The shape measures suggested here aim to provide a general means to classify aging patterns independent of any particular mortality model and independent of any species-specific time-scale. Thereby they support systematic comparative aging research across different species or between populations of the same species under different conditions and constitute an extension of the toolbox available to comparative research in Biodemography.     

Quantifying the Adaptive Cycle

The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems.     

Quantifying the randomness of extinctions

Extinctions occur either randomly or in a more deterministic and predictable manner, with certain characteristics making some species more vulnerable to (local) extinction than others. Although the quantification of extinction randomness would better our understanding of the extinction causes and increase the predictability of future species losses, few quantification methods are currently available. To this purpose, we propose two indices based on a comparison of an a priori (expected) extinction series with an observed one. Whereas the first index requires data on the order of extinctions, the second index is only concerned with which species went extinct and which did not. Using a model for generating extinction data, we tested both indices successfully for accordance with the robustness prerequisites. Index outputs were furthermore unaffected by species richness, apart from decreased variation with rising species numbers. Because of its independence of non-extinct species and its focus on extinction sequences, the first randomness index seems especially useful for use in paleontological and paleo-ecological research. The second index is likely a good tool to study shorter term extinctions, for which the extinction order is often not known and for which the comparison with species that did persist is of greater interest. We use a real dataset to illustrate this. Finally, we discuss how it is possible to expand the use of this index toward identifying previously unknown extinction-promoting species characteristics, and toward a credible assessment of the extinction risk posed by global change.