Artificial Sweat for Humanoid Finger

To achieve favorable Frictional Tactile Sensation （FTS） for robot and humanoid fingers, this report investigated the effects of human finger sweat on Friction Coefficient （FC） and verified the effectiveness of artificial sweat on FTS tbr a humanoid finger. The results show that the model sweat （salt and urea water faked real sweat） increases the FC of the real finger sliding on the high hygroscopic and rough surface （paper）, whereas on the low hygroscopic and smooth surface （PMMA）, the sweat forms a fluid film and decreases FC, restricting severe finger adhesion. Further, the film formation and capillary adhesion force of sweat were discussed. The experimental results with the artificial sweats （ethanol and water） and humanoid finger （silicone rubber skin with tactile sensors） verifies the effectiveness. The artificial sweat restricts severe adhesion （stick-slip vibration）, and enhances cognitive capability of FTS.     

Cooperativity of ligand binding as a function of monomer-dimer equilibrium parameters and acceptor concentration

A general monomer-dimer equilibrium system involving ligand interactions ispresented. Cooperativity features of specific limited models are analyzed by selecting the appropriate family of equilibrium constants from this general scheme. Each system is then characterized in terms of Hill coefficient dependency on alterations in values of equilibrium constants and total acceptor concentration. This method permits comparison of predicted cooperativity trends between systems. Contrasting reports concerning cooperativity dependencies for certain defined equilibrium systems are compared and the discrepancies resolved. Characteristics of cooperativity binding patterns are shown to include symmetry about dimerization association constant values, both positive and negative cooperativity for a single set of parameters, and significant changes in cooperativity features with relatively small changes in equilibrium parameters.     

Transmission from vaccinated individuals in a large SARS-CoV-2 Delta variant outbreak

1. Download : Download high-res image (149KB)
2. Download : Download full-size image

     

Artificial neural network and response surface methodology: a comparative analysis for optimizing rice straw pretreatment and saccharification

Abstract

The present study demonstrates a comparative analysis between the artificial neural network (ANN) and response surface methodology (RSM) as optimization tools for pretreatment and enzymatic hydrolysis of lignocellulosic rice straw. The efficacy for both the processes, that is, pretreatment and enzymatic hydrolysis was evaluated using correlation coefficient (R²) & mean squared error (MSE). The values of R² obtained by ANN after training, validation, and testing were 1, 0.9005, and 0.997 for pretreatment and 0.962, 0.923, and 0.9941 for enzymatic saccharification, respectively. On the other hand, the R² values obtained with RSM were 0.9965 for cellulose recovery and 0.9994 for saccharification efficiency. Thus, ANN and RSM together successfully identify the substantial process conditions for rice straw pretreatment and enzymatic saccharification. The percentage of error for ANN and RSM were 0.009 and 0.01 for cellulose recovery and for 0.004 and 0.005 for saccharification efficiency, respectively, which showed the authority of ANN in exemplifying the non-linear behavior of the system.     

Shared geographic histories and dispersal contribute to congruent phylogenies between amphipods and their microsporidian parasites at regional and global scales

In parasites that strongly rely on a host for dispersal, geographic barriers that act on the host will simultaneously influence parasite distribution as well. If their association persists over macroevolutionary time it may result in congruent phylogenetic and phylogeographic patterns due to shared geographic histories. Here, we investigated the level of congruent evolutionary history at a regional and global scale in a highly specialised parasite taxon infecting hosts with limited dispersal abilities: the microsporidians Dictyocoela spp. and their amphipod hosts. Dictyocoela can be transmitted both vertically and horizontally and is the most common microsporidian genus occurring in amphipods in Eurasia. However, little is known about its distribution elsewhere. We started by conducting molecular screening to detect microsporidian parasites in endemic amphipod species in New Zealand; based on phylogenetic analyses, we identified nine species‐level microsporidian taxa including six belonging to Dictyocoela. With a distance‐based cophylogenetic analysis at the regional scale, we identified overall congruent phylogenies between Paracalliope, the most common New Zealand freshwater amphipod taxon, and their Dictyocoela parasites. Also, hosts and parasites showed similar phylogeographic patterns suggesting shared biogeographic histories. Similarly, at a global scale, phylogenies of amphipod hosts and their Dictyocoela parasites showed broadly congruent phylogenies. The observed patterns may have resulted from covicariance and/or codispersal, suggesting that the intimate association between amphipods and Dictyocoela may have persisted over macroevolutionary time. We highlight that shared biogeographic histories could play a role in the codiversification of hosts and parasites at a macroevolutionary scale.     

Foliar fungal endophyte community structure is independent of phylogenetic relatedness in an Asteraceae common garden

Phylogenetic distance among host species represents a proxy for host traits that act as biotic filters to shape host‐associated microbiome community structure. However, teasing apart potential biotic assembly mechanisms, such as host specificity or local species interactions, from abiotic factors, such as environmental specificity or dispersal barriers, in hyperdiverse, horizontally transmitted microbiomes remains a challenge. In this study, we tested whether host phylogenetic relatedness among 18 native Asteraceae plant species and spatial distance between replicated plots in a common garden affects foliar fungal endophyte (FFE) community structure. We found that FFE community structure varied significantly among host species, as well as host tribes, but not among host subfamilies. However, FFE community dissimilarity between host individuals was not significantly correlated with phylogenetic distance between host species. There was a significant effect of spatial distance among host individuals on FFE community dissimilarity within the common garden. The significant differences in FFE community structure among host species, but lack of a significant host phylogenetic effect, suggest functional differences among host species not accounted for by host phylogenetic distance, such as metabolic traits or phenology, may drive FFE community dissimilarity. Overall, our results indicate that host species identity and the spatial distance between plants can determine the similarity of their microbiomes, even across a single experimental field, but that host phylogeny is not closely tied to FFE community divergence in native Asteraceae.     

Length-weight relationships of 10 fish species from the coastal waters of the East China Sea

The present study provides the length-weight relationships (LWRs) for 10 marine fish species collected from the coastal waters of the East China Sea by bottom trawl surveys. The open width of the sampling net was 40 m and the mesh size of the codend was 20 mm. Specimens were collected from November 2015 to November 2019 at seasonal intervals. The measurement accuracy of weight and length were 0.1 grams and 0.1 centimeters, respectively. This study provides new information of LWRs for nine species which have not yet been reported in FishBase. Also, this study updates the information of maximum length for two species.     

Length-weight relationship of 16 fish species from the Negro River basin (Amazonas state,Brazil)

This study aimed to estimate the parameters of length-weight relationship for 16 freshwater fish species that inhabit the Aracá and Demeni Rivers, which are two tributaries of the Negro River (Amazonas state, Brazil). The fishes were sampled using gillnets (15 × 2 m, mesh size 30–120 mm between opposite knots), during 6 days each year, in April 2016, November 2018 and April 2019. The gillnets were placed in the river twice each day; in the morning (5–9 a.m.) and in the evening (5–9 p.m.), with a standardized time of 4 hr. Measurements were taken for standard length (SL – 0.1 cm precision) and total weight (TW – 0.01 g precision). The parameters a and b of the equation W_T = a.L_T^b were estimated. This study also provides new data on of maximum lengths for six species, namely, Argonectes longiceps, Hemiodus atranalis, Chalceus erythrurus, Astrodoras asterifrons, Trachydoras steindachneri and Acarichthys heckelii.     

Spatially Explicit Assessment of Sandhill Crane Exposure to Potential Transmission Line Collision Risk

Infrastructure development can affect avian populations through direct collision mortality. Estimating the exposure of local bird populations to the risk of direct mortality from infrastructure development requires site- and species-specific data, which managers may find difficult to obtain at the scale over which management decisions are made. We quantify the potential exposure of sandhill cranes (Antigone canadensis) to collision with horizontal structures (e.g., transmission lines) within vital wintering grounds of the Middle Rio Grande Valley (MRGV), New Mexico, USA, 2014–2020. Limited maneuverability and visual acuity make sandhill cranes vulnerable to collisions with infrastructure bisecting their flight paths. We used data from 81 global positioning system (GPS)-tagged cranes to estimate the spatially explicit flight height distribution along the MRGV, the passage rate across hypothetical transmission lines, and the resulting exposure rate (exposed passes/crane/day). The exposure rate ranged from 0–0.28 exposed passes/crane/day (median = 0.015) assuming an exposure zone of 7–60 m above ground level, and identified hotspots of potential exposure within the MRGV. Mapped exposure rates can assist in the siting of proposed high-voltage transmission lines, or other infrastructure, to limit effects on sandhill cranes and other avian species at risk of collision. Our approach can be replicated and applied in similar situations where birds are exposed to possible collision with power lines. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.