Sterilization the Sane “Pesticide”

Unpacking, an effective lesson-planning technique, can help students use scientific inquiry to understand the power behind hurricanes. Teachers identify a concept and then guide students to "unpack" it and look for new discoveries. The activity provides a means for students to develop the abilities to do scientific inquiry, demonstrate how it is applied, and develop understanding about the method. Additionally, students demonstrate abilities of technological design and understanding about science and technology. This activity promotes students' knowledge of the Earth's constant change, pattern recognition to enable prediction, statistical analysis and graphical display to reveal patterns in data, and the science behind hurricane rotation.     

“Neutral theory” and the dynamics of the evolution of “Modern” human morphology

There is a widespread assumption, even among those who reject the Synthetic Theory of Evolution, that the form of “modern”Homo sapiens is somehow superior to that of archaicHomo sapiens (Tattersall 2000). Those who accept the general outlook of evolutionary biology also tend to assume that “modern” form emerged because it was selected for, which also implies that it was better than that which preceded it. However, after years of using craniofacial measurements to compare human populations, I finally came to realize that, with only a few exceptions, the dimensions measured have no relation to differences in adaptation (Brace 1989, 1996, 2000; Brace et al., 1993). Elsewhere the conclusion has been supported that what is shown by craniometrics is selectively neutral on the average (Relethford 2002). With the documentation that approximately 95% of the genome is not functional, molecular genetics has proved to be useful in documenting the length of time of separation of related human populations by investigating the differences that have accumulated in the neutral parts of the genome. Not surprisingly, the picture revealed by the study of genetic differences is very similar to the one revealed by the study of craniometric differences (Brace et al., 2001). For this reason, the logic behind the “neutral theory” in molecular genetics is very similar to that applied to what happens to morphological characteristics when selection ceases (Brace 1963; Kimura 1968). The difference is that random changes in the neutral part of the genome have no other consequences. However, random changes in the genes that produce specific aspects of morphology will be visible even when selection is no longer controlling the particular trait in question. From an assessment of what random changes in genes controlling morphological traits are likely to do, it follows that the most likely change will probably be a reduction in the trait in question, i.e. the Probable Mutation Effect will produce structural reduction. When survival in the temperate zone during the last glaciation dependend on “obligatory cooking”, one of the unintended consequences was a reduction in the selective pressures maintaining a Middle Pleistocene-sized dentition. The result was a gradual reduction in tooth size and a conversion, of a Neanderthal-sized face into one of “modern” dimensions. The manufacture and use of string for snares and nets similarly reduced the selective pressures maintaining post-cranial levels of robustness and muscularity. The reduction in the latter resulted in the emergence of moderm post-cranial robustness out of what had been a Neanderthal level,in situ wherever the technology can be documented and without any need for invasions and replacements.     

From “Periodical Observations” to “Anthochronology” and “Phenology” – the scientific debate between Adolphe Quetelet and Charles Morren on the origin of the word “Phenology”

Mankind has observed and documented life cycle stages of plants and animals for a long time. However, it was comparatively recently that the newly emerging science was given its name. The name of Charles Morren and the year 1853 are being cited, although not frequently. Exact information is hardly known among present-day phenologists, yet new evidence shows that the term “phenology” was already in use in 1849. In the early 1840s, physicist and astronomer Adolphe Quetelet set up an observational network named "Observations of periodical Phenomena of the Animal and Vegetable Kingdom” and issued instructions for it. Even though biologist Charles Morren welcomed Quetelet's initiative, differences between Morren and Quentlet regarding the instructions for the observations and the potential results soon arose and a debate started, which lasted for nearly 10 years. In the wake of these disagreements, Morren was compelled to create a new term to denote his ideas on “periodical phenomena”. At first, he temporally used the word anthochronology, but in the end he coined the word phenology. The term was first used in a public lecture at the Académie royale des Sciences, des Lettres et des Beaux-Arts de Belgique’ in Brussels on 16 December 1849, and simultaneously in the December 1849 issue of volume V of the Annales de la Société royale d’Agriculture et de Botanique de Gand. One had to wait until 1853 before the new name appeared in the title of one of Morren’s publications. Based on evidence from archives and original publications, we trace the 10-year-long scientific debate between Morren and Quetelet. Morren states his biologist’s view on the subject and extends the more climate-related definition of Quetelet of “periodical phenomena”.     

Remarks on the “OTAN” reaction

Summary A series of experiments with the standard OTAN reaction and its modifications was performed in human and animal tissue sections. The coloring obtained in the original OTAN reaction cannot be considered as unequivocal characterisation for hydrophobic and hydrophilic lipids because both kinds of lipids can produce a whole scale of colors ranging from light red to black.The black coloring of hydrophobic lipids can develop after application of -naphtylamine which does not react only by forming a complex but also in the sense of oxidation-reduction.The red coloring of hydrophobic lipids resistant to prehydrolysis by 1 N NaOH in atheromatous plaques and in arcus senilis corneae could be considered erroneously as presence of the sphingomyelin.Hydrophilic lipids can be stained already after 10 minutes treatment with osmium tetroxide and potassium chlorate mixture. After application of -naphtylamine a dark brown to brown-black color can develop in some cases which does not signify the presence of hydrophobic lipids. Nonlipid substances can be stained in the OTAN method as well.Modifications of the OTAN method enabling the differentiation of hydrophobic and hydrophilic lipids and lipopigment are described. These consist of pre-extraction with cold acetone or chloroform-methanol or oxidation by periodic acid.     

Numbers in the Blind's “Eye”

Background

Although lacking visual experience with numerosities, recent evidence shows that the blind perform similarly to sighted persons on numerical comparison or parity judgement tasks. In particular, on tasks presented in the auditory modality, the blind surprisingly show the same effect that appears in sighted persons, demonstrating that numbers are represented through a spatial code, i.e. the Spatial-Numerical Association of Response Codes (SNARC) effect. But, if this is the case, how is this numerical spatial representation processed in the brain of the blind?

Principal Findings

Here we report that, although blind and sighted people have similarly organized numerical representations, the attentional shifts generated by numbers have different electrophysiological correlates (sensorial N100 in the sighted and cognitive P300 in the blind).

Conclusions

These results highlight possible differences in the use of spatial representations acquired through modalities other than vision in the blind population.     

“Tasting” the airway lining fluid

Specialized epithelial cells of the respiratory tract have been termed "solitary chemosensory cells" based upon the expression of components of the canonical sweet, umami and bitter taste transduction pathway, or "brush cells" based upon their characteristic morphological feature, i.e. an apical, brush-like tuft of rigid, villin containing microvilli. Cells defined by these criteria might not match one-to-one, and a generally accepted terminology is still lacking. With respect to cellular shape, ultrastructure, expression of elements of the taste transduction cascade, innervation and synapse formation, and effects evoked upon their stimulation, it appears that chemosensory/brush in the upper respiratory tract (nasal respiratory mucosa, vomeronasal duct, auditory tube), in the olfactory mucosa, in the larynx, in the lower airways (trachea, bronchi) and in the alveolar region (rat only) each represent distinct groups. Still, they have in common to monitor the chemical composition of the mucosal lining fluid. They serve as sentinels detecting bacterial colonization or the presence of other harmful components in the mucosal lining fluid, leading to the initiation of avoidance reflexes and/or local defense mechanisms which are adapted to their anatomical localization. Free nerve endings are also responsive to inhaled irritants and further work will be needed to discriminate between the contributions of such nerve endings and chemosensory cells in chemical monitoring and defense initiation. Interestingly, there is first emerging evidence that respiratory chemosensory cells may respond to more than one canonical taste quality so that they, in analogy to polymodal nociceptors, may serve as polymodal chemosensors of potentially dangerous signals.     

“Apical dominance” in the sporangiophore of the fungus Phycomyces

Summary Control, by the spores, over the elongation and the branching of the sporangiophore is described. If the sporangium is removed from a sporangiophore, the sporangiophore stops growing within a few hours. 6–16h later a branch grows from the defunct growing zone. This branch forms a new sporangium and spores, and then starts to elongate again. The original growing zone can be rescued by replacing the sporangium with another sporangium or a sporangium-sized drop of spores. If the original growing zone is rescued, then it continues growing and the sporangiophore does not form a branch. It can only be rescued, however, within the first 60 min after the original sporangium is removed.This work was submitted in partial fulfillment of the requirements for the Ph. D. degree.     

Insight into the Structure of the “Unstructured” Tau Protein

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Photographing the “Other”: Immigration and New Images of the Greek Ethnic “Self”

ABSTRACT

Significant transformations in the ways the ethnic “self” and its relationship to the “other” are perceived have led to the transgression of the two traditional poles (East and West) that were prevalent in the definition of Greekness since the creation of the Greek nation-state. By placing the photographs of immigrants published in the most popular local newspaper in Central Greece within their wider social and historical context, we can “see” that immigrants (a group that is perceived to be homogeneous and transcendental) constitute a new axis around which the negotiation of ethnic identity and otherness in Greece is now conducted.     

“Double hit” makes the difference

Comment on: Menendez JA, et al. Cell Cycle 2012; 11:2782–92.Metformin (N’, N’-dimethylbiguanide) is an anti-diabetic drug prescribed to more than 100 million patients in the world. In addition to its efficacy for the treatment of diabetes, several recent studies have shown that it has anti-tumoral properties.¹ We and others have shown that metformin targets cancer cell metabolism by inhibiting mitochondrial complex 1 activity.^2,3 This energetic stress leads to a decrease of intracellular ATP concentration, and cancer cells will increase their rate of glycolysis.² This compensatory response is not sufficient to restore ATP levels, but is adequate to maintain viable cells in most of the cancer cells. Indeed, metformin blocks cell growth but can also induce apoptosis in some cancer cell models.⁴ The increase of glycolysis induced by metformin is somehow inconsistent with the observed inhibition of proliferation, since cancer cells use preferentially glycolysis to grow faster. This switch to glycolysis, also known as the “Warburg effect,” is linked to oncogenic transformation⁵ and is accompanied by the hyperactivation of the mTOR pathway. In cancer cells, the increase of glycolysis induced by metformin is associated with a strong inhibition of the mTOR pathway via the AMPK. This new metabolic order established by metformin may explain the paradoxical effect of metformin. In view of the above scenario, Menendez et al. decided to test the synthetic lethality of metformin and combined metformin treatment with glucose starvation. They showed that the treatment of breast cancer cells with metformin alone does not induce apoptosis but arrests cells in G₀/G₁. Glucose starvation by itself induces few apoptosis, but the combination of metformin with the absence of glucose induces massive apoptosis. This is not altogether surprising, since the dual action of metformin and glucose starvation block the two main ways of production of ATP (i.e., mitochondrial respiration and glycolysis) (Fig. 1). This is an interesting observation, which could be valuable for future anticancer therapy; however, glucose starvation is not therapeutically feasible. Thus, the use 2-deoxyglucose (2-DG), an inhibitor of glycolysis, could be useful. We and others found that the combination of 2-DG and metformin inhibits prostate cancer cell proliferation and breast tumor growth in xenograft models.^2,6 Although it induces a slight apoptotic response in vitro, 2-DG alone is not efficient in vivo to alter tumor growth⁶ but improves the curative action of radiotherapy;⁷ similarly, it reinforces metformin action. Another interesting issue raised by Menendez et al. is the use of such dual therapy to target cancer stem cells. Metformin has been shown to selectively kill cancer stem cells and the chemotherapy-resistant subpopulation of cancer stem cells.^8,9 Cancer stem cells greatly depend on aerobic glycolysis to sustain their stemness and immortality. The synthetic lethality induced by metformin and glucose starvation may help to improve chemotherapy action and avoid cancer relapse. In conclusion, targeting cancer cell metabolism with a “dual hit therapy” opens new avenues for the future treatment of cancer.Open in a separate windowFigure 1. The combination of metformin and glucose starvation induces a strong energetic stress. Metformin inhibits the mitochondrial complex 1 and glucose starvation, or 2-DG inhibits ATP production from glycolysis. The combination of the two energetic stresses induces a massive energetic stress and leads to a strong apoptotic response.     

A cladistic approach to the phylogeny of the “Bryophytes”

The importance of a cladistic approach in reconstructing the phylogeny of bryophytes is discussed and illustrated by an analysis of the major groups of bryophytes with respect to the tracheophytes and the green algae. The cladistic analysis, using 51 characters taken from the literature, gives the following tentative results: (1) the embryophytes as a whole are monophyletic; (2) the bryophytes (sensu lato) are paraphyletic; (3) the mosses share a more recent common ancestor with the tracheophytes than do the liverworts or hornworts; (4) the hornworts appear to share a more recent common ancestor with the moss-tracheophyte lineage than with the liverworts; however, the existence of several homoplasies makes this placement more problematical; (5) the origin of alternation of generations in the embryophytes, based on out-group comparison with their oogamous, haplontic, algal sister groups, was by progressive elaboration of the primitively epiphytic sporophyte generation; and (6) the presence of vascular tissue (xylem and phloem) can best be interpreted as a synapomorphy of the moss-tracheophyte clade, and tracheids (xylem with ornamented walls) as a synapomorphy of the tracheophytes; therefore, the prevailing designation of “vascular plants” for the tracheophytes alone is inaccurate.     

“Positive” Results Increase Down the Hierarchy of the Sciences

The hypothesis of a Hierarchy of the Sciences with physical sciences at the top, social sciences at the bottom, and biological sciences in-between is nearly 200 years old. This order is intuitive and reflected in many features of academic life, but whether it reflects the “hardness” of scientific research—i.e., the extent to which research questions and results are determined by data and theories as opposed to non-cognitive factors—is controversial. This study analysed 2434 papers published in all disciplines and that declared to have tested a hypothesis. It was determined how many papers reported a “positive” (full or partial) or “negative” support for the tested hypothesis. If the hierarchy hypothesis is correct, then researchers in “softer” sciences should have fewer constraints to their conscious and unconscious biases, and therefore report more positive outcomes. Results confirmed the predictions at all levels considered: discipline, domain and methodology broadly defined. Controlling for observed differences between pure and applied disciplines, and between papers testing one or several hypotheses, the odds of reporting a positive result were around 5 times higher among papers in the disciplines of Psychology and Psychiatry and Economics and Business compared to Space Science, 2.3 times higher in the domain of social sciences compared to the physical sciences, and 3.4 times higher in studies applying behavioural and social methodologies on people compared to physical and chemical studies on non-biological material. In all comparisons, biological studies had intermediate values. These results suggest that the nature of hypotheses tested and the logical and methodological rigour employed to test them vary systematically across disciplines and fields, depending on the complexity of the subject matter and possibly other factors (e.g., a field''s level of historical and/or intellectual development). On the other hand, these results support the scientific status of the social sciences against claims that they are completely subjective, by showing that, when they adopt a scientific approach to discovery, they differ from the natural sciences only by a matter of degree.     

Revisiting the “Cdk-Centric” View of the Mammalian Cell Cycle

Since the early genetic studies in yeast, regulation of the cell cycle has been associated to the sequential activation of several proline-directed serine-threonine protein kinases by cyclins. From yeast to humans, the activiy of these cyclin-dependent kinases (Cdks) have been thought to be essential for cell cycle regulation. Recent gene-targeted mouse models for different cyclins and Cdks have shown that members of these families show a certain level of redundancy and that specific complexes are not required for the mitotic cell cycle. However, the complexity of the Cdk-cyclin network and the promiscuity of their members makes it difficult to understand the relative contribution of these proteins to the mammalian cell division cycle. Compensatory roles by non-Cdk activities and Cdk-independent functions of cyclins are increasing the complexity of the current simplistic models. We still do not know whether at least one cyclin-dependent kinase activity is required for cell cycle progression in mammalian cells. Indeed, a relevant question for cancer therapy.     

Scientific consequences of the wreck of the “Torrey Canyon”

Summary 1. The re-deployment of the resources of the Plymouth Laboratory required to observe the consequences of the Torrey Canyon disaster were described. Some excerpts were taken from the report (Smith 1968) to be published by the Marine Biological Association of U. K. on 18 March, 1968.2. Field studies were made at sea and on the polluted shores, as well as laboratory studies of the toxicity of the detergents employed to disperse the oil.3. The drift of the oil, established by aerial reconnaissance, was found to be directly ahead of the wind at 3.3 % of the wind speed.4. Now that the 3.3 % factor has been established by direct observation at sea, a limited aerial survey of the area where the oil was predicted to be would have been of more value than the blanket survey of a limited area close to the coast.5. When known, strong surface currents should be added vectorially to the calculated wind-drift. Two examples are quoted, one explaining the differences between calculated drift and the drift observed by the French while oil was northwest of Ushant. The results in the Helgoland Bight were compared.6. The value of craie de Champagne used by the French to sink the oil at sea and the possible part played by the phagotrophic flagellate,Noctiluca miliaris, were discussed.7. Implications of the Torrey Canyon disaster affecting international law and enforcement were developed. The need was stated for an international fire brigade ready to deal with pollution of the sea by an accident on the high seas or on a coast.

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Wissenschaftliche Konsequenzen des Schiffsunglücks der Torrey Canyon

Kurzfassung Einige Gesichtspunkte ozeanographischer und biologischer Untersuchungen, die unmittelbar nach dem Auflaufen des Öltankers Torrey Canyon im Englischen Kanal (März 1967) in Angriff genommen worden sind, werden geschildert. Unter anderem werden die Ölverdriftung durch Wind und Fragen der Toxizität der Detergentien, welche zur Dispergierung des ausgelaufenen Öls benutzt wurden, behandelt. Im Großeinsatz hat sich französische Kreide (craie de Champagne) als besonders wirksam erwiesen. Die Beteiligung von Mikroorganismen und des FlagellatenNoctiluca miliaris beim Ölabbau wird diskutiert. Auf eine zusammenfassende, von der Marine Biological Association herausgegebene Darstellung der wissenschaftlichen Ergebnisse, welche nach dem Tankerunglück erarbeitet worden sind, wird hingewiesen.

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The two papers which I presented at the International Symposium 1967 of the Biologische Anstalt Helgoland were not scientific papers in the usual sense but news reports of much interest only at the time. The colour photographs had all been lent by colleagues. Seven of these in black and white, have been published in Penn ar Bed which contains the article byBrusson (1967). Close counterparts of others are appearing in the Plymouth Report (Smith 1968). There seems no point in duplicate publication. The appearance of the Breton publication Penn ar Bed (in French) and further information has made it possible to add to some of the interim reports. The paper byBrusson (1967) has been especially useful. It has been thought better to give the latest views rather than a verbatim account from the tape recordings taken at the Symposium. The two addresses given at the Symposium have therefore been combined and condensed and then developed with the help of new material.