Reconsidering Darwin’s “Several Powers”

Contemporary textbooks often define evolution in terms of the replication, mutation, and selective retention of DNA sequences, ignoring the contribution of the physical processes involved. In the closing line of The Origin of Species, however, Darwin recognized that natural selection depends on prior more basic living functions, which he merely described as life’s “several powers.” For Darwin these involved the organism’s capacity to maintain itself and to reproduce offspring that preserve its critical functional organization. In modern terms we have come to recognize that this involves the continual generation of complex organic molecules in complex configurations accomplished with the aid of persistent far-from-equilibrium chemical self-organizing and self-assembling processes. But reliable persistence and replication of these processes also requires constantly available constraints and boundary conditions. Organism autonomy further requires that these constraints and co-dependent dynamics are reciprocally produced, each by the other. In this paper I argue that the different constraint-amplifying dynamics of two or more self-organizing processes can be coupled so that they reciprocally generate each other’s critical supportive boundary conditions. This coupling is a higher-order constraint (which can be distributed among components or offloaded onto molecular structures) that effectively constitutes a sign vehicle “interpreted” by the synergistic dynamics of these co-dependent self-organizing process so that they reconstitute this same semiotic-dynamic relationship and its self-reconstituting potential in new substrates. This dynamical co-dependence constitutes Darwin’s “several powers” and is the basis of the biosemiosis that enables evolution.     

The Biosemiotic Concept of the Species

Any biological species of biparental organisms necessarily includes, and is fundamentally dependent on, sign processes between individuals. In this case, the natural category of the species is based on family resemblances (in the Wittgensteinian sense), which is why a species is not a natural kind. We describe the mechanism that generates the family resemblance. An individual recognition window and biparental reproduction almost suffice as conditions to produce species naturally. This is due to assortativity of mating which is not based on certain individual traits, but on the difference between individuals. The biosemiotic model described here explains what holds a species together. It also implies that boundaries of a species are fundamentally fuzzy, and that character displacement occurs in case of sympatry. Speciation is a special case of discretisation that is an inevitable result of any communication system in work. The biosemiotic mechanism provides the conditions and communicative restrictions for the origin and persistence of diversity in the realm of living (communicative and semiotic) systems.     

Exposure Estimation for Risk Assessment of the Phthalate Incident in Taiwan

Background

In May 2011, di(2-ethylhexyl) phthalates (DEHP) and, to a lesser extent, di-iso-nonyl phthalate (DiNP) were found to have been illegally used for many years in Taiwan as clouding agents in foods including sports drinks, juice beverages, tea drinks, fruit jam/nectar/jelly, and health or nutrient supplements.

Objective

To estimate the DEHP exposure for the study participants for the follow-up epidemiological study and health risk assessment.

Methods

A total of 347 individuals possibly highly exposed to phthalate-tainted foods participated in the study. Exposure assessment was performed based on the participants'' responses to a structured questionnaire, self-report of exposure history, urinary metabolite concentrations, and DEHP concentration information in 2449 food records. A Bayesian statistical approach using Markov chain Monte Carlo simulation was employed to deal with the uncertainties in the DEHP concentrations of the contaminated foods and the participants'' likelihood of being exposed.

Results

An estimated 37% and 15% of children younger than 12 years old were exposed to DEHP at medium (20–50 μg / kg_bw / day) and high AvDIs (50–100 μg / kg_bw / day), respectively, prior to the episode (9% and 3% in adults, respectively). Moreover, 11% of children and 1% of adults were highly exposed (> 100 μg / kg_bw / day), with a maximum of 414.1 μg / kg_bw / day and 126.4 μg / kg_bw / day, respectively.

Conclusions

The phthalate exposure-associated adverse health effects for these participants warrant further investigation. The estimation procedure may be applied to other exposure assessment with various sources of uncertainties.     

Dibutyryl-cAMP affecting fat deposition of finishing pigs by decreasing the inflammatory system related to insulin sensitive or lipolysis

Background

The mechanism of db-cAMP regulating fat deposition and improving lean percentage is unclear and needs to be further studied.

Methods

Eighteen 100-day-old Duroc × Landrance × Large White barrows (49.75?±?0.75 kg) were used for experiment 1, and 15 eighteen 135-day-old barrows (78.34?±?1.22 kg) were used for experiment 2 to investigate the effects of dietary dibutyryl-cAMP (db-cAMP) on fat deposition in finishing pigs. Pigs were fed with a corn-soybean meal-based diet supplemented with 0 or 15 mg/kg db-cAMP, and both experiments lasted 35 days, respectively.

Results

The results showed that db-cAMP decreased the backfat thickness, backfat percentage, and diameter of backfat cells without changing the growth performance or carcass characteristics in both experiments, and this effect was more marked in experiment 1 than in experiment 2; db-cAMP enhanced the activity of the growth hormone–insulin-like growth factor-1 (GH-IGF-1) axis and pro-opiomelanocortin (POMC) system in both experiments, which suppressed the accumulation of backfat deposition; microarray analysis showed that db-cAMP suppressed the inflammatory system within the adipose tissue related to insulin sensitivity, which also reduced fat synthesis.

Conclusions

In summary, the effect of db-cAMP on suppressing fat synthesis and accumulation is better in the earlier phase than in the later phase of finishing pigs, and db-cAMP plays this function by increasing the activity of the GH-IGF-1 axis and POMC system, while decreasing the inflammatory system within the adipose tissue related to insulin sensitive or lipolysis.

     

Effect of Hydrothermal Modifications on Functional,Pasting and Structural Properties of False Banana (<Emphasis Type="Italic">Ensete ventricosum</Emphasis>) Starch

Starch extracted from ensete (Ensete ventricosum, Musaceae) also called false banana, was modified by hydrothermal methods of annealing (ANN) and heat moisture treatment (HMT) processes. The effects of treatments on functional, pasting properties, morphology and diffraction pattern of the starch were studied. Swelling power and solubility changed significantly (p < 0.05) with modification. Water absorption (89.3–152.4 %) and oil absorption (105.0–161.3 %) capacities increased significantly (p < 0.05) with ANN and HMT. Alkaline water retention decreased with ANN but increased significantly (p < 0.05) with HMT. Hydrothermal modifications led to reduction in least gelation capacity of ensete starch. In terms of the pasting properties studied, the hydrothermal modifications imparted improved gel strength, increased paste stability, reduced retrogradation tendency and slowed staling rate on ensete starch. Scanning electron micrographs depicted fairly angular and elliptical shapes with diverse sizes for the starch granules. Clustering of granules, mucilage formation, fissures and surface indentation which were gaining prominence with increasing moisture level and temperature of treatment were the hallmarks of modified samples. Native and modified ensete starches showed similar type-B diffraction pattern with maximum peak range of 19.8–20.0^o (2θ). Findings of this work showed that hydrothermally modified ensete starches possess excellent value-added potentials for utilization in pharmaceuticals and food applications.     

Simplifying Hansen Solubility Parameters for Complex Edible Fats and Oils

Hansen solubility parameters (HSPs), often used to predict the miscibility between two compounds, are an alternative tool in evaluating the ability of the solvent to interact via dispersion, dipole-dipole, and hydrogen bonding interactions. The aim of this paper is to find a simple way to calculate HSPs for complex mixtures of triglycerides (TAGs). HSPs were calculated using two approaches: the first assumes that the contributions to the dispersion, dipole-dipole, and hydrogen bonding interactions may be subdivided into larger functional moieties (i.e., fatty acids and fatty acid methyl esters) that are additive, while the second approach assumes that vegetable oils are comprised of mixtures of simple TAGs in the same mass fractions as the fatty acids. The HSPs obtained using the two approaches are compared to reference values determined using the “Hansen Solubility Parameters in Practice” software (HSPiP) considering the complex TAG profile for each vegetable oil.HSPs for vegetable oils, obtained with the HSPiP software, did not correspond well to the HSPs obtained from the group contribution approach, when using fatty acids, fatty acids + glycerol or fatty acid methyl esters. In contrast, the HSPs calculated for vegetable oils, assuming that all TAGs are simple and in the same mass fractions as the fatty acids, provide similar values to the HSPs obtained from the HSPiP software. Therefore, it is possible to calculate the HSPs for complex oils by simply knowing the fatty acid composition. Knowledge of HSPs may be used to rationalize the ability of certain low molecular weight molecules to develop organogels in vegetable oils as well as the crystallization of triglycerides.     

Population size and land use affect the genetic variation and performance of the endangered plant species <Emphasis Type="Italic">Dianthus seguieri</Emphasis> ssp. <Emphasis Type="Italic">glaber</Emphasis>

Human activity and land use changes in the past decades have led to landscape homogenization and small-scale fragmentation of grassland habitats in most regions of central Europe. As a result, populations of many grassland species are small and strongly fragmented, facing extinction due to genetic depauperation and local maladaptation in remnant habitats. In this study, remaining populations of the strongly endangered grassland species Dianthus seguieri ssp. glaber (“Ragged Pink”) in Bavaria were investigated in order to evaluate the environmental factors influencing its genetic variation and performance. We first evaluated habitat, vegetation and population structure. Species performance was then studied by assessing the number of generative shoots, flowers and fertile capsules; and evaluating seed weight and seed viability. Finally, genetic variation was analyzed using molecular markers (AFLPs). Our analyses revealed that population size and land use abandonment have the strongest impact on genetic variation and species’ performance. Large and extended populations were most variable. 72 % of overall genetic variability of Dianthus seguieri ssp. glaber was found to be within populations, whereas 28 % remained between populations. Increased vegetation height and coverage, and a high proportion of gramineous species resulting from the lack of land use, reduced genetic variation, effective fruit and seed set. Our study shows that both population size and land use abandonment need to be considered to ensure the long term protection of endangered plant species. Maintaining an open habitat structure and adequate soil nutrient conditions through targeted annual mowing regime, over-storey vegetation trimming and green waste removal and the establishment of vegetation buffer strips will allow this species’ persistence and continuous recruitment.