Can the theory of evolution be falsified?

In this paper we discuss the epistemological positions of evolution theories. A sharp distinction is made between the theory that species evolved from common ancestors along specified lines of descent (here called the theory of common descent), and the theories intended as causal explanations of evolution (e.g. Lamarck's and Darwin's theory). The theory of common descent permits a large number of predictions of new results that would be improbable without evolution. For instance, (a) phylogenetic trees have been validated now; (b) the observed order in fossils of new species discovered since Darwin's time could be predicted from the theory of common descent; (c) owing to the theory of common descent, the degrees of similarity and difference in newly discovered properties of more or less related species could be predicted. Such observations can be regarded as attempts to falsify the theory of common descent. We conclude that the theory of common descent is an easily-falsifiable & often-tested & still-not-falsified theory, which is the strongest predicate a theory in an empirical science can obtain. Theories intended as causal explanations of evolution can be falsified essentially, and Lamarck's theory has been falsified actually. Several elements of Darwin's theory have been modified or falsified: new versions of a theory of evolution by natural selection are now the leading scientific theories on evolution. We have argued that the theory of common descent and Darwinism are ordinary, falsifiable scientific theories.     

What may be the markers of the male equivalent of polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS), the most common endocrinopathy in women (with a prevalence of 5-10 %), is characterized by hormonal and metabolic imbalance. Complexity of symptoms of close relatives of women with PCOS and genetic autosomal trait initiated a hypothesis about the existence of a male equivalent of PCOS. Premature alopecia was suggested as one of the signs of a male phenotype of this syndrome. The present study investigated a group of 30 men, in which premature hair loss started before 30 years of age. In all patients, their hormonal profile was determined. It was possible to form two subgroups. The first one showed similar hormonal changes as women with PCOS, the other had either no anomalies in steroid spectrum or just only lower level of sexual hormones binding globulin (SHBG). Both subgroups did not differ in either BMI or age. In all men with premature alopecia insulin tolerance test was also carried out and the occurrence of allele 3 INS VNTR was investigated, which is one of the candidate genes for PCOS. The subgroup with hormonal changes resembling those of women with PCOS showed a significantly higher insulin resistance than the group without these changes. About one third of the premature balding men showed the combination of hormonal shifts and higher insulin resistance. This frequency corresponds to the prevalence of PCOS in women. There was no significant difference between the two subgroups in the occurrence of allele 3 INS VNTR.     

Cancer of the lung: what should be the present approach?

The best opportunities at present for improving the results in the treatment of patients with cancer of the lung are by way of (a) utilizing the information obtained on routine x-ray examination of the chest, (b) decreasing the delay between the time of the first symptoms and the time the patient consults a physician, and (c) decreasing the delay between the time the patient first consults a physician and the time the cancer is surgically removed. The medical profession must increase its index of suspicion of cancer of the lung and persist in efforts to make a diagnosis when lung cancer is suspected. Exploratory thoracotomy should be used in suspicious cases when the diagnosis cannot be established by other methods.     

Can the stereochemical outcome of glycosylation reactions be controlled by the conformational preferences of the glycosyl donor?

Previous static and dynamical density functional theory studies of the 2,6-di-O-acetyl-3,4-O-isopropylidene-D-galactopyranosyl cations and their methanol adducts has led to an hypothesis that these cations exist in two families of conformers characterized as (2)S(O) and B(2,5), respectively. These families differ by ring inversion, each with its own reactivity. New calculations on the 2,6-di-O-acetyl-3,4-di-O-methyl-D-galactopyranosyl cation confirmed these trends. Removing the isopropylidene group allows more flexibility, but two families of conformers can be discerned with the monocyclic oxocarbenium ions in the E(3) conformation and the bicyclic dioxolenium ions in the (4)H(5) conformation. Attack on the beta-face of these monocyclic cations is favored by hydrogen bonding and the anomeric effect. The experimentally observed high beta-stereoselectivity of mannopyranosyl donors and high alpha-stereoselectivity of glucopyranosyl donors with the 4,6-O-benzylidene protecting groups can be rationalized assuming that the trans-fused 1,3-dioxane ring allows population of only one family of conformers. The combination of hydrogen bonding and conformational changes of the pyranose ring in response to the C-5[bond]O-5[bond]C-1[bond]C-2 torsion angle changes are identified as key factors in stereoselectivity. Based on these observations a strategy to design face discriminated glycosyl donors that exist predominantly in only one family of conformers is proposed.     

What should the Z-score of native protein structures be?

The Z-score of a protein is defined as the energy separation between the native fold and the average of an ensemble of misfolds in the units of the standard deviation of the ensemble. The Z-score is often used as a way of testing the knowledge-based potentials for their ability to recognize the native fold from other alternatives. However, it is not known what range of values the Z-scores should have if one had a correct potential. Here, we offer an estimate of Z-scores extracted from calorimetric measurements of proteins. The energies obtained from these experimental data are compared with those from computer simulations of a lattice model protein. It is suggested that the Z-scores calculated from different knowledge-based potentials are generally too small in comparison with the experimental values.     

Can the meaning of multiple words be integrated unconsciously?

What are the limits of unconscious language processing? Can language circuits process simple grammatical constructions unconsciously and integrate the meaning of several unseen words? Using behavioural priming and electroencephalography (EEG), we studied a specific rule-based linguistic operation traditionally thought to require conscious cognitive control: the negation of valence. In a masked priming paradigm, two masked words were successively (Experiment 1) or simultaneously presented (Experiment 2), a modifier (‘not’/‘very’) and an adjective (e.g. ‘good’/‘bad’), followed by a visible target noun (e.g. ‘peace’/‘murder’). Subjects indicated whether the target noun had a positive or negative valence. The combination of these three words could either be contextually consistent (e.g. ‘very bad - murder’) or inconsistent (e.g. ‘not bad - murder’). EEG recordings revealed that grammatical negations could unfold partly unconsciously, as reflected in similar occipito-parietal N400 effects for conscious and unconscious three-word sequences forming inconsistent combinations. However, only conscious word sequences elicited P600 effects, later in time. Overall, these results suggest that multiple unconscious words can be rapidly integrated and that an unconscious negation can automatically ‘flip the sign’ of an unconscious adjective. These findings not only extend the limits of subliminal combinatorial language processes, but also highlight how consciousness modulates the grammatical integration of multiple words.     

Can the grey mould disease of the grape-vine be controlled by yeast?

Botrytis cinerea has been found to be highly pathogenic to 'Chardonnay' and 'Pinot noir' cultivars of the grape-vine producing the characteristic grey mould symptoms within 7 days of inoculation to the vitro-plants. The yeast Pichia anomala (strain FY-102), isolated from apple skin, was found to be antagonistic to B. cinerea as it completely inhibited the appearance of the grey mould symptoms when grown together. The yeast was responsible for morphological changes such as coagulation and leakage of the cytoplasm of B. cinerea. The pathogen, when applied together with P. anomala, failed to bring about the grey mould symptoms on the grape-vine, suggesting that the yeast could control the expression of this disease. An account of the interaction between B. cinerea and P. anomala, as well as the sequences of the complete ITS region of the ribosomal DNA of the yeast are described here.     

Can the function of the extirpated amygdaloid complex be compensated for by the transplantation of embryonic nerve tissue?

In 20 white rats bilateral coagulation of the amygdalar complex was produced; on the fifth day to one half of them transplantation was performed by introducing stereotaxically on the left side 0.2-0.5 mm3 of the brain embryonal tissue from the corresponding area of the amygdala of 20-days embryo; in control saline was administered. After two months the rats were sacrificed to determine the activity of antiradical defense by superoxide dismutase (SOD) and the level of lipids peroxide oxidation (LPO) in the cerebral cortex. The transplantation decreased LPO even more and increased SOD as compared to amygdalectomy, e. i. caused still greater deviations from the norm (in this meaning--paradoxal effect), what apparently corresponds to intensification of adaptative-compensatory processes caused by amygdalectomy. The transplantation did not reverse the rats behaviour to the initial one and did not eliminate memory defect in the test of conditioned reaction of passive avoidance (like pyrazetam); it had different direction influence on "drinking under current" in conflict situation, only in particular cases approaching it to the norm.     

Can giant chlorosomes be part of the light-harvesting antennae of green bacteria?

Some data on the structure and composition of chlorosomes are in conflict with their energy and kinetic characteristics. Among the latter is the very short excitation lifetime of the dominant pigment C740 in the 3D giant chlorosome (about 1000 pigment molecules per reaction center). Therewith the excitation transfer from C740 to baseplate bacteriochlorophyll B795 and further to the main membrane B860 can hardly be efficient. This result was obtained by modeling the energy migration between these pigment fractions in maximally optimized conditions. The possible reasons and mechanisms responsible for such strong nonphotochemical quenching of electronic excitations in the pigments of giant chlorosomes are substantiated and discussed.     

When can the cause of a population decline be determined?

Inferring the factors responsible for declines in abundance is a prerequisite to preventing the extinction of wild populations. Many of the policies and programmes intended to prevent extinctions operate on the assumption that the factors driving the decline of a population can be determined. Exogenous factors that cause declines in abundance can be statistically confounded with endogenous factors such as density dependence. To demonstrate the potential for confounding, we used an experiment where replicated populations were driven to extinction by gradually manipulating habitat quality. In many of the replicated populations, habitat quality and density dependence were confounded, which obscured causal inference. Our results show that confounding is likely to occur when the exogenous factors that are driving the decline change gradually over time. Our study has direct implications for wild populations, because many factors that could drive a population to extinction change gradually through time.     

Will the enigma of Francisella tularensis virulence soon be solved?

Francisella tularensis is one of the most infectious bacterial pathogens known and is the causative agent of the zoonotic disease tularemia. In spite of the importance of this pathogen little is known about its virulence mechanisms. However, it is clear that the bacterium is an intracellular pathogen, replicating mainly in macrophages, with replication in amoebae also having been reported. The genome sequence of a high virulence strain of F. tularensis is close to completion and when available, will stimulate further research into virulence mechanisms.     

Challenges of the utilization of wood polymers: how can they be overcome?

Diminishing fossil fuel resources as well as growing environmental and energy security concerns, in parallel with growing demands on raw materials and energy, have intensified global efforts to utilize wood biopolymers as a renewable resource to produce biofuels and biomaterials. Wood is one of the most abundant biopolymer composites on earth that can be converted into biofuels as well as used as a platform to produce bio-based materials. The major biopolymers in wood are cellulose, hemicelluloses, and lignin which account for >90% of dry weight. These polymers are generally associated with each other in wood cell walls resulting in an intricate and dynamic cell wall structure. This mini-review provides an overview of major wood biopolymers, their structure, and recent developments in their utilization to develop biofuels. Advances in genetic modifications to overcome the recalcitrance of woody biomass for biofuels are discussed and point to a promising future.     

Could the egg itself be the source of the oviposition deterrent marker in the ectoparasitoid Dinarmus basalis?

Females of Dinarmus basalis, a solitary ectoparasitoid, strongly avoid superparasitising hosts bearing eggs which are 20 or more hours old. Our objective was to determine the mechanism by which the factors inducing host discrimination and such an oviposition deterring effect act, and the origin of the deterrent. This study showed that the information is carried by the parasitised host. It is acquired by a transfer of molecules from the wasp egg onto the host and it requires contact between egg and host for at least 4 h. The factors transferred do not, as commonly reported in other species, come from the female's genital apparatus but from the live egg itself. Consequently, the D. basalis egg directly participates in the success of parasitism by releasing factors which elicit the oviposition host deterring effect. The originality and the ecological importance of these results are discussed.