Non-differentiability of quasi-potential and non-smooth dynamics of optimal paths in the stochastic Morris–Lecar model: Type I and II excitability

2019 ◽  
Vol 96 (4) ◽  
pp. 2293-2305 ◽  
Author(s):  
Zhen Chen ◽  
Jinjie Zhu ◽  
Xianbin Liu
2021 ◽  
Author(s):  
Francisco Valdepena ◽  
Dante Mujica Vargas ◽  
Antonio Luna-Alvarez ◽  
Miguel Angel Ruiz-Jaimes
Keyword(s):  
Type I ◽  

FLORESTA ◽  
2014 ◽  
Vol 44 (1) ◽  
pp. 1
Author(s):  
Henrique Moreira Dabien Haddad ◽  
Lucas Rezende Gomide ◽  
Bruno Rogério Cruz ◽  
Sérgio Teixeira Da Silva

AbstractCerrado presents great potential for the use of its resources, whether timber or non-timber, as fruits, firewood and charcoal. Thus, this study aimed to test the use of forest regulation model type I in a remnant of cerrado, applying the integer linear programming. The studied area was a remnant of cerrado sensu stricto located in São Romão – MG. The type of forest management carried out was the strip cutting. with post regeneration conduction. The model type I was applied generating 8 scenarios considering 14 years of planning horizon. The tested scenarios considered the area control, volume control and also both controls in the same model, where the objective function was to maximize the present value of revenues (PVR). After data processing it was observed that scenario 5 was the best, because it obtained the lowest amplitude variation (425 – 575 ha/year) and volume (18.000 – 21.000 m3/year) of the exploited surface limits, presenting a PVR of R$4,004,561.58. It is possible to conclude that the developed models were able to regulate the volumetric yield in constant flows over the planning horizon, representing a promising alternative for the sustainable planning of the wood resources of the cerrado.Keywords: Mathematical programming; forest regulation; forest management. ResumoUma abordagem aplicada da programação linear inteira no manejo do cerrado. O cerrado apresenta um grande potencial de uso de seus recursos, sejam eles madeireiros ou não madeireiros, como frutos, lenha e carvão vegetal. Assim, o trabalho teve como objetivo testar o uso do modelo tipo I de regulação florestal em um remanescente de cerrado utilizando a programação linear inteira. A área de estudo foi um remanescente de cerrado sensu stricto localizado em São Romão – MG. O regime de manejo elaborado foi o corte em faixas com posterior condução da regeneração. O modelo tipo I foi aplicado gerando 8 cenários em um horizonte de planejamento de 14 anos. Os cenários testados consideraram o controle por área, por volume, bem como ambos no mesmo modelo, sendo a função objetivo o valor presente das receitas (VPR) a ser maximizado. Após o processamento dos modelos observou-se que o cenário 5 foi o melhor, possuindo limites de área explorada (425 – 575 ha/ano) e volumétricos (18.000 – 21.000 m3/ano) com menor variação de amplitude, apresentando R$4.004.561,58 de VPR. Pôde-se concluir que os modelos formulados foram capazes de regular a produção volumétrica em fluxos constantes ao longo do horizonte de planejamento, em sua grande maioria, constituindo-se de uma alternativa promissora ao planejamento sustentável dos recursos madeireiros do cerrado.Palavras-chave: Programação matemática; regulação florestal; manejo florestal.


Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.


Author(s):  
E. Horvath ◽  
K. Kovacs ◽  
I. E. Stratmann ◽  
C. Ezrin

Surgically removed human pituitary glands as well as pituitary tumors fixed in glutaraldehyde, postfixed in osmium tetroxide, embedded in epon resin, stained with uranyl acetate and lead citrate have been investigated by electron microscopy in order to correlate ultrastructure with functional activity. In the course of this study two distinct types of microfilaments have been identified in the cytoplasm of adenohypophysiocytes.Type I microfilaments (Fig. 1) were found in the cytoplasm of anterior lobe cells of five female subjects with disseminated mammary cancer and two patients with severe diabetes mellitus. The breast cancer patients were treated pre-operatively for various periods of time with different doses of oxysteroids. The microfilaments had an average diameter of JO A, formed parallel bundles, were scattered irregularly in the cytoplasm and were frequently located in the perikaryon. They were not membrane-bound and failed to show any periodicity.


Author(s):  
W. Jurecka ◽  
W. Gebhart ◽  
H. Lassmann

Diagnosis of metabolic storage disease can be established by the determination of enzymes or storage material in blood, urine, or several tissues or by clinical parameters. Identification of the accumulated storage products is possible by biochemical analysis of isolated material, by histochemical demonstration in sections, or by ultrastructural demonstration of typical inclusion bodies. In order to determine the significance of such inclusions in human skin biopsies several types of metabolic storage disease were investigated. The following results were obtained.In MPS type I (Pfaundler-Hurler-Syndrome), type II (Hunter-Syndrome), and type V (Ullrich-Scheie-Syndrome) mainly “empty” vacuoles were found in skin fibroblasts, in Schwann cells, keratinocytes and macrophages (Dorfmann and Matalon 1972). In addition, prominent vacuolisation was found in eccrine sweat glands. The storage material could be preserved in part by fixation with cetylpyridiniumchloride and was also present within fibroblasts grown in tissue culture.


Author(s):  
E.M. Kuhn ◽  
K.D. Marenus ◽  
M. Beer

Fibers composed of different types of collagen cannot be differentiated by conventional electron microscopic stains. We are developing staining procedures aimed at identifying collagen fibers of different types.Pt(Gly-L-Met)Cl binds specifically to sulfur-containing amino acids. Different collagens have methionine (met) residues at somewhat different positions. A good correspondence has been reported between known met positions and Pt(GLM) bands in rat Type I SLS (collagen aggregates in which molecules lie adjacent to each other in exact register). We have confirmed this relationship in Type III collagen SLS (Fig. 1).


Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.


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