Nonlinear-Optical Analogies in Nuclear-Like Soliton Reactions:Selection Rules,Nonlinear Tunneling and Sub-Barrier Fusion–Fission

The main goal of our study is to reveal unexpected but intriguing analogies arising between optical solitons and nuclear physics,which still remain hidden from us.We consider the main cornerstones of the concept of nonlinear optics of nuclear reactions and the well-dressed repulsive-core solitons.On the base of this model,we reveal the most intriguing properties of the nonlinear tunneling of nucleus-like solitons and the soliton selfinduced sub-barrier transparency effect.We describe novel interesting and stimulating analogies between the interaction of nucleus-like solitons on the repulsive barrier and nuclear sub-barrier reactions.The main finding of this study concerns the conservation of total number of nucleons(or the baryon number)in nuclear-like soliton reactions.We show that inelastic interactions among well-dressed repulsive-core solitons arise only when a“cloud”of“dressing”spectral side-bands appears in the frequency spectra of the solitons.This property of nucleus-like solitons is directly related to the nuclear density distribution described by the dimensionless small shape-squareness parameter.Thus the Fourier spectra of nucleus-like solitons are similar to the nuclear form factors.We show that the nuclear-like reactions between well-dressed solitons are realized by“exchange”between“particle-like”side bands in their spectra.

Effect of human disturbance on the structure and regeneration of forests in the Nevado de Toluca National Park, Mexico

Sample plots were established in the principal forest types in the the Nevado de Toluca National Park, Mexico including those domi- nated by Pinus hartwegii, Abies religiosa, Quercus laurina and Alnus jorullensis. The vertical structure was defined by three strata in the coniferous forests and two strata in the broadleaved forests. Timber harvesting in Abies religiosa and Quercus laurina forests and fires generated by humans in Pinus hartwegii forests impeded the recruitment of saplings. Mature trees were also heavily impacted by logging in Pinus hartwegii forests. On the contrary, Alnusjorullensis forests were increas- ing due to the disturbance of Pinus and Quercus forests, as well aban- doned crop lands within the park. A combination of logging, uncon- trolled fire, and grazing appears to be compromising the recruitment of important tree species in this national park. These factors, together with human settlements, have also increased the proportion of early succes- sional species. Changes in forest structure from human disturbance indicate a need to control these activities if conservation goals are not to be compromised.

Insects as alternative feed for ruminants:comparison of protein evaluation methods

Background:The high dependence of intensive ruminant production on soybean meal and the environmental impact of this crop encourage the search for alternative protein-rich feeds.The use of insects seems promising,but the extent of their ruminal protein degradation is largely unknown.This parameter has major influence not only on N utilization efficiency but also on the environmental burden of ruminant farming.In addition,although assessing ruminal N degradation represents a key first step to examine the potential of new feeds,it is a challenging task due to the lack of a reference method.This study was conducted to investigate the potential of 4 insects(Tenebrio molitor,Zophobas morio,Alphitobius diaperinus and Acheta domesticus)as alternative protein sources for ruminants,using 3 methodologies:1)a regression technique based on the in vitro relationship between gas production and ammonia-N concentration;2)a conventional in vitro technique of batch cultures of ruminal microorganisms,based on filtering the incubation residue through sintered glass crucibles;and 3)the in situ nylon bag technique.The in vitro intestinal digestibility of the non-degraded protein in the rumen was also determined.Soybean meal was used as a reference feedstuff.Results:Comparison of evaluation methods(regression,in vitro and in situ)did not allow to reliably select a single value of ruminal N degradation for the studied substrates,but all techniques seem to establish a similar ranking,with good correlations between methods,particularly between regression and in situ results.Regardless of the methodology,nitrogen from the 4 insects(with contents ranging from 81 to 112 g/kg of dry matter)did not show high ruminal degradation(41–76%),this value being always lower than that of soybean meal.Furthermore,the in vitro intestinal digestibility of non-degraded N was relatively high in all feeds(≥64%).Conclusion:Overall,these results support the potential of the 4 studied insects as alternative feedstuffs for ruminants.Among them,T.molitor showed the lowest and greatest values of ruminal N degradation and intestinal digestibility,respectively,which would place it as probably the best option to replace dietary soybean meal and increase the sustainability of ruminant feeding.

Non-Topological Solitons as Traveling Pulses along the Nerve

Several new soliton-like structures have been obtained under the consideration of non trivial boundary condition for the difference value of density in the thermodynamic model of nerve pulses. The model is based on thermodynamic principles of zero transfer of energy to the media. We have studied these solutions for particular values in the parameter space, and obtained both bell soliton on the condensate and bubble like solutions as typical non-topological representative solutions. The solutions will propagate along the nerve with constant velocity. The analysis of the properties of the solutions provides us with available permitted velocities and the prediction of the constant density value of the background at long distances far from the excited zone in the nerve.

Ar/N2/CH4 Glow Discharge at Low Pressures

Ar/N2/CH4 glow discharge at low-pressure are studied in a closed system. The plasma was produced in 79.6% N2-15.4% Ar- 5.0% CH4 ternary mixture at pressures between 0.5 and 10.0 Torr. The diagnostic has been made by optical emission spectroscopy （OES）. The principal species observed were： N2, N2＋, CH＋, CN, C2, C3, HI3, Ha, C＋ and At. It presents the behaviour of the bands and lines intensities as a function of the pressure. Also, it displays the ratios of intensities of N＋2 （391.44 nm）, CN （392.08 nm）, and H （486.13 nm） to that of the N2 （337.13 rim） as function of pressure. The ratios show a slow decreasing behavior as a function of the pressure. Being the CH/N2 ratio more highest and H/N2 ratio the lowest one. The variations of excited species at different pressures may change the subsequent chemical reactions in the gas phase significantly. The present results suggest that the ion-molecule and molecule-molecule reactions in the gas phase are likely to play a dominant role in the present pressures.

Coyote(Canis latrans)in South America:potential routes of colonization

During the last century,the coyote(Canis latrans)has increased its distribution in Central America.Before the 1980s,it had not been recorded in Panama.New records show that coyotes have crossed the Panama Canal,indicating that continues to expand;therefore,there is a possibility that it will reach northern South America.Our objectives were to identify potential coyote colonization routes to South America,and the variables that favor its expansion.We hypothesized that habitat fragmentation benefits coyote expansion.We applied 7 algorithms to model the potential distribution of the coyote,using 196 presence records and 12 variables.The models with better performance were used to generate a consensus model.Using our consensus model and the areas with highest probability of presence,a potential colonization route was generated between Central America and northern South America.This route lies through southern Costa Rica,along the Pacific coast of Panama to the south,to the Andean mountains in northern Colombia.The variables that explained potential coyote distribution were human population density,altitude,and percentage of crops with positive influence,and tropical broadleaf forests with negative in-fluence.These results indicate that human activities and deforestation are related to coyote distribution expansion.Actions can be implemented within the identified route to improve environmental management,in order to avoid the presence of the coyote in the ecosystems of northern South America.