Life sciences experiments on Spacelab 1

NASA Technical Reports Server (NTRS)

Buderer, M. C.; Salinas, G. A.

1980-01-01

The objectives and procedures regarding various biological experiments to be conducted on Spacelab 1 are reviewed. These include the mapping of the HZE cosmic ray particle flux within the Spacelab module, investigating the effects of nullgravity on circadian cycles in the slime mold, Neurospora crassa, and measuring nutations of the dwarf sunflower, Helianthus annus. Emphasis is placed on research regarding possible changes in vestibulocular reflexes, vestibulospinal pathways, cortical functions involving perception of motion and spatial susceptibility. Also discussed are experiments regarding erythrokinetics in man and the effects of prolonged weightlessness of the humoral immune response in humans.

Effects of several salt marsh plants on mouse spleen and thymus cell proliferation using mtt assay

NASA Astrophysics Data System (ADS)

Seo, Youngwan; Lee, Hee-Jung; Kim, You Ah; Youn, Hyun Joo; Lee, Burm-Jong

2005-12-01

In the present study, we have tested the effects of 21 salt marsh plants on cell proliferation of mouse immune cells (spleen and thymus) using MTT assay in culture. The methanolic extracts of six salt marsh plants ( Rosa rugosa, Ixeris tamagawaensis, Artemisia capillaris, Tetragonia tetragonoides, Erigeron annus, and Glehnia littoralis) showed very powerful suppressive effects of mouse immune cell death and significant activities of cell proliferation in vitro. Especially, the methanolic extract of Rosa rugosa was found to have fifteen times compared to the control treatment, demonstrating that Rosa rugosa may have a potent stimulation effect on immune cell proliferation. These results suggest that several salt marsh plants including Rosa rugosa could be useful for further study as an immunomodulating agent.

Degradation of PVC/HC blends. II. Terrestrial plant growth test.

PubMed

Pascu, Mihaela; Agafiţei, Gabriela-Elena; Profire, Lenuţa; Vasile, Cornelia

2009-01-01

The behavior at degradation by soil burial of some plasticized polyvinyl chloride (PVC) based blends with a variable content of hydrolyzed collagen (HC) has been followed. The modifications induced in the environment by the polymer systems (pH variation, physiologic state of the plants, assimilatory pigments) were studied. Using the growth test of the terrestrial plants, we followed the development of Triticum (wheat), Helianthus annus minimus (little sunflower), Pisum sativum (pea), and Vicia X hybrida hort, during a vegetation cycle. After the harvest, for each plant, the quantities of chlorophyll and carotenoidic pigments and of trace- and macroelements were determined. It was proved that, in the presence of polymer blends, the plants do not suffer morphological and physiological modifications, the products released in the culture soil being not toxic for the plants growth.

Celebrating the physics in geophysics

NASA Astrophysics Data System (ADS)

Davis, Anthony B.; Sornette, Didier

The United Nations' Educational, Scientific and Cultural Organization (UNESCO) declared 2005 the “World Year of Physics” in celebration of the centennial of Einstein's annus mirabilis when, as junior clerk at the Swiss Patent Office in Berne, he published three papers that changed physics forever by (1) introducing Special Relativity and demonstrating the equivalence of mass and energy (E = mc2), (2) explaining the photoelectric effect with Planck's then-still-new-and-controversial concept of light quanta (E = hv), and (3) investigating the macroscopic phenomenon of Brownian motion using Boltzmann's molecular dynamics (E = kT), still far from fully accepted at the time.The celebration of Einstein's work in physics inspires the reflection on the status of geophysics and its relationship with physics, in particular with respect to great discoveries.

Behavior of metalaxyl and its pure R-enantiomer in sunflower plants (Helianthus annus).

PubMed

Zadra, C; Marucchini, C; Zazzerini, A

2002-09-11

A possible stereospecific and/or stereoselective mechanism of biodegradation for metalaxyl and metalaxyl-M was studied to elucidate their behavior in sunflower plants and to compare their biodegradation. Greenhouse experiments were carried out to confirm the same efficacy of the two fungicides against infections by Plasmopara helianthi in sunflower plants. The two fungicides appear to have the same behavior regarding both the protection against plant infections and the mode of translocation and the rate and pathway of biotransformation, but we have evidence that this biotransformation process is enantioselective. Furthermore, we propose procedures for a chromatographic separation of enantiomers and acid metabolites of the fungicides and for the determination of the R:S ratio by HPLC chiral analyses. This study emphasizes the importance of examining the fate of both stereoisomers of a chiral agrochemical in an environmental system for the correct use of enantiomerically pure agrochemical compounds.

Low proton conductance of plant cuticles and its relevance to the acid-growth theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dreyer, S.A.; Seymour, V.; Cleland, R.E.

1981-09-01

Evidence obtained on the relation between the pH of the medium and the growth of intact stem sections is compatible with the acid-growth theory only if the proton conductance of the cuticle is an effective barrier to the entry or exit of protons from the tissue. By measuring the rate at which protons cross frozen-thawed epidermal strips of sunflower (Helianthus annus L.) and soybean hypocotyls (Glycine max Morr.) and enzymically isolated cuticles of Berberis aquifolium Persh. and tomato (Lycopersicum esculentum Mill.) fruit, we have now demonstrated the low proton conductance of the cuticular layer. Unless the conductance is enhanced bymore » abrasion of the cuticle or by removal of the cuticular waxes, proton movement into and out of a tissue across the cuticle will be significant only over long time periods.« less

Neither a year nor an annus can be a derived unit in the SI

USGS Publications Warehouse

Edwards, Lucy E.

2011-01-01

The year is not a unit of the SI. The only SI unit of measurement for time is the second. The word “annus” or “annum” does not appear anywhere in the current SI document. The word “year” is not in the table of “Non-SI units accepted for use with the International System of Units,” nor in the table of “Non-SI units whose values in SI units must be obtained experimentally,” nor even in the table of “Other non-SI units.” The year can be found, however, through the list of “Other non-SI units not recommended for use.” This heading directs the reader to a National Institute of Standards and Technology (NIST) list where three kinds of year (365 days, sidereal, and tropical) are given with conversion to seconds, but are set in type to indicate “in general not to be used in NIST publications.” Table 1 summarizes some of the uses of the year in other publications. For example, in the IUPAC chemistry document, the year is not a constant; in the International Astronomy Union Style Guide, the year (Julian) is a constant.   

Cradles of industry and occupational medicine in the modern world: Milan 1906 -- Annus Mirabilis.

PubMed

Baldasseroni, A; Carnevale, F; Tomassini, L

2013-01-01

The example examined is Milan, Italy's main industrial city, where the great International Exhibition was held in 1906. This was the culmination of a period of accelerated industrial growth that modern-day historiography considers to be when Italy's first real industrial revolution began. The twenty-five years between the National Industrial Exhibition of 1881, which was also held in Milan, and the 1906 Exhibition truly reflected a period which was crucial for this transformation to take of. Alongside industry, which was then going through a phase of reorganization and development, Milanese civil society was increasingly turning its interest and attention to what was called the "social question". In an atmosphere of debate and exchange of ideas and experience with Turin, another major industrial city of the north and the birthplace of the Italian engineering and automobile industries, social organizations, political parties and trade unions began to be established thus heralding the Italian approach towards twentieth-century welfare. This is the context in which the first International Congress on Occupational Diseases was held in Milan from 9 to 14 June 1906 within the framework of the International Exhibition. The success achieved with this initiative. organized by Luigi Devoto and Malachia De Cristoforis, which was to continue with the founding of the International Permanent Commission on Occupational Health, showed that the time was ripe for a new subject to appear on the scene--the occupational health physician--who from then on was to play an important role in the promotion of workers' health. The article outlines the main features of the Italian industrial transformation at the turn of the new century with special attention focused on Milan, the capital of industry in Italy. It also describes the impact on public opinion caused by the events surrounding the epic construction of the transalpine railway tunnels which began in 1856 with the Mont Cenis tunnel, then the tragic enterprise of the St. Gotthard tunnel in 1883, ending in 1906 with the inauguration of the Simplon tunnel. The Milan congress is examined as well as the developments which, from then on, began increasingly to give physicians specialised in occupational diseases a higher profile in events of an international nature in the defence of workers' health but also in the interests of economic development.

Optical parameters of leaves of seven weed species

NASA Technical Reports Server (NTRS)

Gausman, H. W.; Menges, R. M.; Richardson, A. J.; Walter, H.; Rodriguez, R. R.; Tamez, S. (Principal Investigator)

1982-01-01

The absorption coefficient (k), infinite reflectance (R), and scattering coefficient (s) were tabulated for five wavelengths and analyzed for statistical differences for seven weed species. The wavelengths were: 0.55-micrometer, 0.65-micrometers, 0.85-micrometer, 1.65-micrometers, and 2.20-micrometer. The R of common lambsquarters (Chenopodium album L.), Johnsongrass (Sorghum halepense (L.) Pers.), and annual sowthistle (Sonchus oleraceus L.) leaves at the 0.85-micrometer wavelength were significantly (p=0.05) higher than for sunflower (Heliantus annus L.), ragweed parthenium (Parthenium hysterophorus L.), or London rocket (Sisymbrium irio L.). Annual sowthistle had the largest k value, and Plamer amaranth (Amaranthus palmer S. Wats.) had the smallest k value at the 0.65 approximately chlorophyll absorption wavelength. In general, john-songress, ragweed parthenium, or London rocket had the largest s values among the five wavelengths, wereas annual sowthistle and plamar amaranth were usually lowest.

[The development of treatment in the Birstonas health resort up to 1939 and the physicians of Birstonas in the 19th and first half of the 20th century].

PubMed

Kierzek, Andrzej; Kuciel-Lewandowska, Jadwiga; Paprocka-Borowicz, Malgorzata; Pozowski, Andrzej; Rejman, Przemysław

2013-01-01

First of all, the history and development of Birstonas, a health resort by the river Neman, near Vilnius, first mentioned in 1382, are recounted in detail. The value of this health resort was determined by a mild climate and salt springs. Information on Birstonas by Władysław Syrokomla (1823-1862), the Polish poet, and Zygmunt Gloger (1845-1910), the Polish ethnographer, archaeologist and historian are well known. The indications and contraindications in many diseases, and the effects of treatment in this health resort are described. Finally, the opportunities for recreation and the attractions in this charming health resort are presented. Attention was paid to the leading role of Poles in the development of this health resort now in Lithuania. The biographies of several physicians practicing in Birstonas: Jan Sokołowski, Aleksander T.W. Korewa, Anicety Renier, Stanisław K. Wikszemski, Benedykt Bilifiski, Erminio Andriolli, Roman Przybylski and Paweł A. Sawicki are presented. Their biographies, professional achievements and work in Birstonas are depicted in detail.

[Remarks on Leon Popielski's manuscript of his review of January Zubrzycki's qualifying thesis for professorship dating from 1915].

PubMed

Heimrath, T

1994-01-01

A review written by professor Leon Popielski from Lvov of the qualifying thesis for professorship of January Zubrzycki from Cracow is presented. The manuscript has been kept by professor Popielski's family. Zubrzycki finished his medical studies in Cracow in 1909. While writing his qualifying thesis entitled Placental Albumin Derivatives and their Toxic Properties in 1915 he was an assistant of Aleksander Rosner in the department of maternity and gynaecology of Jagiellonian University. In 1931 as a professor he became the head of the clinic and following the Second World War he was a professor at several faculties of medicine in Poland. He was an outstanding gynaecological surgeon, an author of a five volume atlas of gynaecological surgery. Professor Leon Popielski studied in S. Petersburg. He specialized in physiology. Since 1904 he was the head of the Chair of Pharmacologoy and Pharmacognosy at the Universitiy of Lvov. Popielski's intrest in Zubrzycki's work ensued his research on albumin metabolite effect. His appreciation of the work is expressed by the phrase "I read it with satisfaction". The review was written in 1919, belated by the war.

Dynamical systems theory and applications

NASA Astrophysics Data System (ADS)

Awrejcewicz, Jan

2006-08-01

The 7th International Conference devoted to "Dynamical Systems-Theory and Applications" hold in 8-11 December, 2003 in Łódź, Poland, and it was organized by the staff of Department of Automatics and Biomechanics of the Technical University of Łódź. It was financially supported by the Rector of the Technical University of Łódź and the Department of Education and Physical Culture of the Łódź City Hall. The members of the International Scientific Committee included: Igor V. Andrianov (Dniepropetrovsk), Jan Awrejcewicz (Łódź), Iliya Blekhman (Sankt Petersburg), Roman Bogacz (Warszawa), Dick van Campen (Eindhoven), Zbigniew Engel (Kraków), Lothar Gaul (Stuttgart), Józef Giergiel (Kraków), Michał Kleiber (Warszawa), Vadim A. Krysko (Saratov), Włodzimierz Kurnik (Warszawa), Claude-Henri Lamarque (Lyon), Leonid I. Manevitch (Moscow), Jan Osiecki (Warszawa), Wiesaw Ostachowicz (Gdańsk), Ladislav Pust (Prague), Giuseppe Rega (Rome), Tsuneo Someya (Tokyo), Zbigniew Starczewski (Warszawa), Eugeniusz Świtoński (Gliwice), Andrzej Tylikowski (Warszawa), Tadeusz Uhl (Kraków), Aleksander F. Vakakis (Illinois), Józef Wojnarowski (Gliwice).

Accumulation of Apoplastic Iron in Plant Roots 1

PubMed Central

Longnecker, Nancy; Welch, Ross M.

1990-01-01

We hypothesized that the resistance of Hawkeye (HA) soybean (Glycine max L.) to iron-deficiency induced chlorosis (IDC) is correlated to an ability to accumulate a large pool of extracellular-root iron which can be mobilized to shoots as the plants become iron deficient. Iron in the root apoplast was assayed after efflux from the roots of intact plants in nutrient solution treated with sodium dithionite added under anaerobic conditions. Young seedlings of HA soybean accumulated a significantly larger amount of extracellular iron in their roots than did either IDC-susceptible PI-54619 (PI) soybean or IDC-resistant IS-8001 (IS) sunflower (Helianthus annus L.). Concurrently, HA soybean had much higher concentrations of iron in their shoots than either PI soybean or IS sunflower. The concentration of iron in the root apoplast and in shoots of HA soybean decreased sharply within days after the first measurements of extracellular root iron were made, in both +Fe and −Fe treatments. The accumulation of short-term iron reserves in the root apoplast and translocation of iron in large quantities to the shoot may be important characteristics of IDC resistance in soybeans. PMID:16667242

Chemistry and biology of phototropism-regulating substances in higher plants.

PubMed

Yamamura, S; Hasegawa, K

2001-01-01

Most people are familiar with the sight of a young seedling bending towards a window or the brightest source of light to which it is exposed. This directional growth response is known as phototropism, which is caused by a lateral growth-promoting auxin in the bending organ (Cholodny-Went theory, cited in high school textbook). Recently, however, Bruinsma et al., Weiler et al., and Hasegawa et al. independently found that the shaded half did not contain more auxin than the illuminated one. Instead it was found that the even distribution of auxin was accompanied by a lateral gradient of growth inhibiting substances during phototropic curvature (Bruinsma-Hasegawa theory). We have isolated some photo-induced growth inhibitory substances related to phototropism, benzoxazolinones from light-grown maize shoots (Zea mays L.), raphanusanins from radish hypocotyl (Raphanus sativus var. hortensis f. gigantissimus M.), indolyacetonitrile from light-grown shoots (Brassica oleacea L.), 8-epixanthatin from sunflower hypocotyl (Helianthus annus L.), and quite recently uridine from oat coleoptile (Avena sativa L.). Chemical analyses have shown phototropic stimulations to cause curvature by inducing a local unequal distribution of growth-inhibiting substances that antagonize auxin in its cell-elongating activity. Finally, a model is presented for further studies on phototropism. Copyright 2001 The Japan Chemical Journal Forum and John Wiley & Sons, Inc.

Report - Screening of the Anti-hyperglycemic activity of some medicinal plants of Jordan.

PubMed

Alkofahi, Ahmad S; Abdul-Razzak, Khalid K; Alzoubi, Karem H; Khabour, Omar F

2017-05-01

Diabetes represents a group of common diseases that are characterized by dysregulation of blood glucose levels. Plants are traditionally used for management of diseases including diabetes. In this study, we screened the anti-diabetic effect of extracts of 21 plants grown in Jordan. Extracts of plants were screened for their antihyperglycemic activity. Diabetes was induced in Sprague Dawley rats using Alloxan. Plant extracts were dosed at 1gm/kg. Blood glucose was measured at baseline and at every hour for 3 hours. Results showed that five plants out of the 21 screened showed antihyperglycemic activity. These plants are Phoenix dactylifera L., Tecoma stans (L.) Kunth, Cichorium pumilum Jacq., Phaseolus vulgaris L., and Teucrium polium L. On the other hand, Sarcopoterium spinosum (L.) Spach. and Brassica oleracea L. var. capitata significantly increased blood glucose levels in diabetic rats. The following plant extracts showed neutral effect on blood glucose levels: Plantago major L., Taraxacum cyprium H. Lindb, Artemisia inculta Delile, Marrubium vulgare L., Inula viscosa (L.) Ai, Rubus sanguineus Friv, Coriandrum sativum L., Cucurbita pepo var ovefera, Cucumis sativus L., Hordeum vulgare L., Apium graveolens L., Avena sativa L., Helianthus annus L., and Anethum graveolens L. In conclusion, Jordanian medicinal plants might be useful for managements of blood glucose levels in patients with diabetes.

Liquid Crystal Formation from Sunflower Oil: Long Term Stability Studies.

PubMed

da Rocha-Filho, Pedro Alves; Maruno, Mônica; Ferrari, Márcio; Topan, José Fernando

2016-06-09

The Brazilian biodiversity offers a multiplicity of raw materials with great potential in cosmetics industry applications. Some vegetable oils and fatty esters increase skin hydration by occlusivity, keeping the skin hydrated and with a shiny appearance. Sunflower (Helianthus annus L.) oil is widely employed in cosmetic emulsions in the form of soaps, creams, moisturizers and skin cleansers due to the presence of polyphenols and its high vitamin E content. Liquid crystals are systems with many applications in both pharmaceutical and cosmetic formulations and are easily detected by microscopy under polarized light due to their birefringence properties. The aim of this research was to develop emulsions from natural sunflower oil for topical uses. Sunflower oil (75.0% w/w) was combined with liquid vaseline (25.0% w/w) employing a natural self-emulsifying base (SEB) derivative. The high temperature of the emulsification process did not influence the antioxidant properties of sunflower oil. Fatty esters were added to cosmetic formulations and extended stability tests were performed to characterize the emulsions. Fatty esters like cetyl palmitate and cetyl ester increase the formation of anisotropic structures. O/W emulsions showed acidic pH values and pseudoplastic behavior. The presence of a lamellar phase was observed after a period of 90 days under different storage conditions.

A review of the contributions of Albert Einstein to earth sciences--in commemoration of the World Year of Physics.

PubMed

Martínez-Frías, Jesús; Hochberg, David; Rull, Fernando

2006-02-01

The World Year of Physics (2005) is an international celebration to commemorate the 100th anniversary of Einstein's "Annus Mirabilis." The United Nations has officially declared 2005 as the International Year of Physics. However, the impact of Einstein's ideas was not restricted to physics. Among numerous other disciplines, Einstein also made significant and specific contributions to Earth Sciences. His geosciences-related letters, comments, and scientific articles are dispersed, not easily accessible, and are poorly known. The present review attempts to integrate them as a tribute to Einstein in commemoration of this centenary. These contributions can be classified into three basic areas: geodynamics, geological (planetary) catastrophism, and fluvial geomorphology. Regarding geodynamics, Einstein essentially supported Hapgood's very controversial theory called Earth Crust Displacement. With respect to geological (planetary) catastrophism, it is shown how the ideas of Einstein about Velikovsky's proposals evolved from 1946 to 1955. Finally, in relation to fluvial geodynamics, the review incorporates the elegant work in which Einstein explains the formation of meandering rivers. A general analysis of his contributions is also carried out from today's perspective. Given the interdisciplinarity and implications of Einstein's achievements to multiple fields of knowledge, we propose that the year 2005 serve, rather than to confine his universal figure within a specific scientific area, to broaden it for a better appreciation of this brilliant scientist in all of his dimensions.

Fresnel's laws, ceteris paribus.

PubMed

Wright, Aaron Sidney

2017-08-01

This article is about structural realism, historical continuity, laws of nature, and ceteris paribus clauses. Fresnel's Laws of optics support Structural Realism because they are a scientific structure that has survived theory change. However, the history of Fresnel's Laws which has been depicted in debates over realism since the 1980s is badly distorted. Specifically, claims that J. C. Maxwell or his followers believed in an ontologically-subsistent electromagnetic field, and gave up the aether, before Einstein's annus mirabilis in 1905 are indefensible. Related claims that Maxwell himself did not believe in a luminiferous aether are also indefensible. This paper corrects the record. In order to trace Fresnel's Laws across significant ontological changes, they must be followed past Einstein into modern physics and nonlinear optics. I develop the philosophical implications of a more accurate history, and analyze Fresnel's Laws' historical trajectory in terms of dynamic ceteris paribus clauses. Structuralists have not embraced ceteris paribus laws, but they continue to point to Fresnel's Laws to resist anti-realist arguments from theory change. Fresnel's Laws fit the standard definition of a ceteris paribus law as a law applicable only in particular circumstances. Realists who appeal to the historical continuity of Fresnel's Laws to combat anti-realists must incorporate ceteris paribus laws into their metaphysics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of gamma-irradiated melon, pumpkin, and sunflower seeds by electron paramagnetic resonance spectroscopy and gas chromatography-mass spectrometry.

PubMed

Sin, Della W M; Wong, Yiu Chung; Yao, Wai Yin

2006-09-20

Seeds of melon (Citrullus lanatus var. sp.), pumpkin (Cucurbita moschata), and sunflower (Heliantus annus) were gamma-irradiated at 1, 3, 5, and 10 kGy and analyzed by electron paramagnetic resonance (EPR) and gas chromatography-mass spectrometry (GC-MS) according to EN1787:2000 and EN1785:2003, respectively. Distinguishable triplet signals due to the presence of induced cellulose radicals were found at 2.0010-2.0047 g in the EPR spectra. The gamma-irradiated radiolytic markers of 2-dodecylcyclobutanone (2-DCB) and 2-tetradecylcyclobutanone (2-TCB) were identified in all irradiated seed samples. Both the free radicals and the alkylcyclobutanones were found to increase with irradiation dose. In general, linear relationships between the amount of radicals and irradiation dosage could be established. Studies at an ambient temperature (20-25 degrees C) in a humidity-controlled environment showed a complete disappearance of the cellulosic peaks for irradiated samples upon 60 days of storage. Such instability behavior was considered to render the usefulness of using EPR alone in the determination of irradiated seed samples. On the other hand, 2-DCB and 2-TCB were also found to decompose rapidly (>85% loss after 120 days of storage), but the radiolytic markers remained quantifiable after 120 days of postirradiation storage. These results suggest that GC-MS is a versatile and complimentary technique for the confirmation of irradiation treatment to seeds.

Nutritional evaluation of Zambia indigenous soy bean (Glycine max) and sunflower (Helianthus annus) as protein sources in poultry and pigs diets.

PubMed

Aregheore, E M

1998-10-01

Two trials were carried out to compare the nutritional values of two Zambian indigenous plant protein sources--soy bean cake (SBC) and sunflower meal (SFM) in the diets of broilers and growing pigs. In trial 1, 120 one week old chickens (Abbor acre strain) were used. There were no differences (P > 0.05) between chickens on SBC and SFM in voluntary feed intake. Average daily gain of SBC chickens differed (P < 0.05) from those of SFM. The protein source had an effect (P < 0.05) on N retained [g/day]. Carcasses dry matter and crude protein were higher (P < 0.05) in SBC chickens, but ash, ether extract, Ca and P were the same as SFM. In trial 2, 12 Large white x Landrace growing barrows 1-2 months old were used. In this trial, SBC diet was consumed more than SFM. Pigs on SBC and SFM gained 0.526 and 0.284 g/head/day, respectively (P < 0.05). Nutrient digestibility was higher (P < 0.05) in SBC diet. Trial 1, demonstrated that SBC and SFM could be used for broilers without adverse effect on growth rate and body conformation. However, for growing pigs SBC is a better protein source than SFM in the tropical environment of Zambia. Finally, results obtained seem to suggest that SBC and SFM can be used as plant protein sources, but SFM is not an ideal plant protein source for growing pigs.

Beneficial Use of Produced Water from Oil and Gas Operations for Agriculture: Effects on Crop Health and Crop Uptake of Contaminants

NASA Astrophysics Data System (ADS)

Sedlacko, E.; Blaine, A. C.; Haynes, K. M.; Higgins, C. P.

2016-12-01

The balance between water conservation and energy generation is difficult to maintain. Oil and gas (O&G) companies look to dispose of produced water in safe, economical ways, while farmers desperate for water seek plentiful sources to maintain their fields. The solution seems simple—purify the water from O&G operations and deliver it to the farmers for irrigation to ensure a reliable source of food. Unfortunately, little research has been conducted to date that could provide purification guidelines, risk warnings, or standard methods for how to implement this solution. In addition, multiple barriers to implementation including regulatory, economic, liability, and social license considerations, must be addressed. This presentation contains data regarding the uptake of compounds two crops, Triticum aestivum (spring wheat) and Helianthus annus (sunflower), grown in a controlled greenhouse environment and irrigated with different dilutions of raw and treated produced water from O&G operations. Differences in plant height, plant color, leaf area, and plant mass were examined, and additional laboratory analyses were conducted on the plants to detect uptake of inorganic and organic substances. Plant stress was also assessed both qualitatively and through plant hormone analysis. In addition, this project provided the opportunity for K-12 teachers to become involved in university research through a new National Science Foundation Research Experience for Teachers (RET) program at Colorado School of Mines. The subsequent impacts of this food-energy-water nexus research on local communities and local STEM curricula via the RET program will also be highlighted.

Natural Oils for Skin-Barrier Repair: Ancient Compounds Now Backed by Modern Science.

PubMed

Vaughn, Alexandra R; Clark, Ashley K; Sivamani, Raja K; Shi, Vivian Y

2018-02-01

Natural plant oils are commonly used as topical therapy worldwide. They are usually easily accessible and are relatively inexpensive options for skin care. Many natural oils possess specific compounds with antimicrobial, antioxidant, anti-inflammatory, and anti-itch properties, making them attractive alternative and complementary treatments for xerotic and inflammatory dermatoses associated with skin-barrier disruption. Unique characteristics of various oils are important when considering their use for topical skin care. Differing ratios of essential fatty acids are major determinants of the barrier repair benefits of natural oils. Oils with a higher linoleic acid to oleic acid ratio have better barrier repair potential, whereas oils with higher amounts of irritating oleic acid may be detrimental to skin-barrier function. Various extraction methods for oils exist, including cold pressing to make unrefined oils, heat and chemical distillation to make essential oils, and the addition of various chemicals to simulate a specific scent to make fragranced oils. The method of oil processing and refinement is an important component of selecting oil for skin care, and cold pressing is the preferred method of oil extraction as the heat- and chemical-free process preserves beneficial lipids and limits irritating byproducts. This review summarizes evidence on utility of natural plant-based oils in dermatology, particularly in repairing the natural skin-barrier function, with the focus on natural oils, including Olea europaea (olive oil), Helianthus annus (sunflower seed oil), Cocos nucifera (coconut oil), Simmondsia chinesis (jojoba oil), Avena sativa (oat oil), and Argania spinosa (argan oil).

Entrapment of a volatile lipophilic aroma compound (d-limonene) in spray dried water-washed oil bodies naturally derived from sunflower seeds (Helianthus annus)☆

PubMed Central

Fisk, Ian D.; Linforth, Robert; Trophardy, Gil; Gray, David

2013-01-01

Oil bodies are natural emulsions that can be extracted from oil seeds and have previously been shown to be stable after spray drying. The aim of the study was to evaluate for the first time if spray dried water-washed oil bodies are an effective carrier for volatile lipophilic actives (the flavour compound d-limonene was used as an example aroma compound). Water-washed oil bodies were blended with maltodextrin and d-limonene and spray dried using a Buchi B-191 laboratory spray dryer. Lipid and d-limonene retention was 89–93% and 24–27%. Samples were compared to processed emulsions containing sunflower oil and d-limonene and stabilised by either lecithin or Capsul. Lecithin and Capsul processed emulsions had a lipid and d-limonene retention of 82–89%, 7.7–9.1% and 48–50%, 55–59% respectively indicating that water-washed oil bodies could retain the most lipids and Capsul could retain the most d-limonene. This indicates that whilst additional emulsifiers may be required for future applications of water-washed oil bodies as carriers of lipophilic actives, oil bodies are excellent agents for lipid encapsulation. PMID:24235784

Oilfield water treatment by electrocoagulation-reverse osmosis for agricultural use: effects on germination and early growth characteristics of sunflower.

PubMed

de Souza, Paulo S A; Cerqueira, Alexandre A; Rigo, Michelle M; de Paiva, Julieta L; Couto, Rafael S P; Merçon, Fábio; Perez, Daniel V; Marques, Monica R C

2017-05-01

This study aims to evaluate the effects of oilfield water (OW), treated by a hybrid process of electrocoagulation and reverse osmosis (EC-RO), on seed germination and early growth characteristics of sunflower (Heliantus annus L.). In the EC step, tests were conducted with 28.6 A m -2 current density and 4 min. reaction time. In the RO step, the system was operated with 1 L min -1 constant flow and 2 MPa, 2.5 MPa and 3 MPa feed pressures. In all feed pressures, RO polymeric membranes achieved very high removals of chemical oxygen demand (up to 89%) and oils and greases (100%) from EC-treated effluent. In best feed pressure (2.5 MPa), turbidity, total dissolved salts, electrical conductivity, salinity, toxic ions and sodium adsorption ratio values attained internationally recognized standards for irrigation water. Using EC-RO (feed pressure:2.5 MPa) treated OW, germinated sunflower seeds percentage (86 ± 6%), speed of germination (30 ± 2) and biomass production (49 ± 5 mg) were statistically similar to control (distilled water) results. Vigor index average values obtained using OW treated by EC-RO (3871)were higher than that obtained by OW water treated by EC (3300). The results of this study indicate that EC-RO seems to be a promising alternative for treatment of OW aiming sunflower crops irrigation, since the use of this treated effluent did not affect adversely seed germination and seedling development, and improved seedling vigor. Furthermore, OW treatment by EC-RO reduces sodium levels into acceptable standards values avoiding soil degradation.

Interactive Effects of Large- and Small-Scale Sources of Feral Honey-Bees for Sunflower in the Argentine Pampas

PubMed Central

Sáez, Agustín; Sabatino, Malena; Aizen, Marcelo A.

2012-01-01

Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha) of natural habitat, represented by untilled isolated “sierras”, and narrow (3–7 m wide) strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus). We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group) at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0–10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services. PMID:22303477

Interactive effects of large- and small-scale sources of feral honey-bees for sunflower in the Argentine Pampas.

PubMed

Sáez, Agustín; Sabatino, Malena; Aizen, Marcelo A

2012-01-01

Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha) of natural habitat, represented by untilled isolated "sierras", and narrow (3-7 m wide) strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus). We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group) at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0-10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services.

Artificial Neural Network applied to lightning flashes

NASA Astrophysics Data System (ADS)

Gin, R. B.; Guedes, D.; Bianchi, R.

2013-05-01

The development of video cameras enabled cientists to study lightning discharges comportment with more precision. The main goal of this project is to create a system able to detect images of lightning discharges stored in videos and classify them using an Artificial Neural Network (ANN)using C Language and OpenCV libraries. The developed system, can be split in two different modules: detection module and classification module. The detection module uses OpenCV`s computer vision libraries and image processing techniques to detect if there are significant differences between frames in a sequence, indicating that something, still not classified, occurred. Whenever there is a significant difference between two consecutive frames, two main algorithms are used to analyze the frame image: brightness and shape algorithms. These algorithms detect both shape and brightness of the event, removing irrelevant events like birds, as well as detecting the relevant events exact position, allowing the system to track it over time. The classification module uses a neural network to classify the relevant events as horizontal or vertical lightning, save the event`s images and calculates his number of discharges. The Neural Network was implemented using the backpropagation algorithm, and was trained with 42 training images , containing 57 lightning events (one image can have more than one lightning). TheANN was tested with one to five hidden layers, with up to 50 neurons each. The best configuration achieved a success rate of 95%, with one layer containing 20 neurons (33 test images with 42 events were used in this phase). This configuration was implemented in the developed system to analyze 20 video files, containing 63 lightning discharges previously manually detected. Results showed that all the lightning discharges were detected, many irrelevant events were unconsidered, and the event's number of discharges was correctly computed. The neural network used in this project achieved a

[Evaluation of a new medium, eggplant (Solanum melongena) agar as a screening medium for Cryptococcus neoformans in environmental samples].

PubMed

Sengul, Mustafa; Ergin, Cağrı; Kartal, Tuğba

2014-04-01

Cryptococcus neofomans is an encapsulated yeast-like fungus that causes life-threatening infections, especially in immunosuppresive patients. C.neoformans infection is believed to be acquired via inhalation of aerosolized particles from the environment. Avian guano, decaying tree hollows and soil are the related known environmental niches. Brown pigmented yeast growth from the precursors in growth media is an important step for the identification and isolation of C.neoformans. Seeds of plants in nature are preferred owing to easy accessibility and low costs for the preparation of such media. Guizotia abysinicca (Niger seed) as Staib agar, Helianthus annus (Sunflower) as Pal's medium, Brassica nigra (Mustard) agar, tobacco agar, Mucuna pruriens (Velvet bean) seed agar, Perilla frutescens (Beefsteak plant) seed agar, Rubus fruticosus (Blackberry) agar and ground red hot pepper agar are pigment-based selective media for the differentiation of C.neoformans. The aim of this study was to observe the pigment production of C.neoformans in a new medium based on eggplant (Solanum melongena) and also to compare its performance with the simplified Staib, Pal's and tobacco agar for isolation from the environment. Three different eggplant-based medium (S.melongena Melanzaza viserba, S.melongena Pinstripe F1 and S.ovigerum Ivory F1) were included in the study. Pigment-forming eggplant medium, simplified Staib agar, Pal's agar and tobacco agar were used for the cultivation of the environmental swabbed samples from 19 Eucalyptus camaldulensis trunk hollows in continuous colonization region. While pigment formation were observed with S.melongena Melanzaza viserba and S.melongena Pinstripe F1 containing media, S.ovigerum Ivory F1 medium was found to be non-reactive. In colonization area (Gökova-Akyaka, Turkey), 11 (57.9%) out of 19 E.camaldulensis samples were positive with simplified Staib agar, Pal's agar and eggplant agar while 10 (52.6%) of them are positive with tobacco agar. C

Jet Propulsion Laboratory: Annual Report 2004

NASA Technical Reports Server (NTRS)

2005-01-01

Once or twice in an age, a year comes along that the historians proclaim as an Annus Mirabilis - a year of wonders. For the Jet Propulsion Laboratory, 2004 was just that sort of time. From beginning to end, it was a nonstop experience of wondrous events in space. Imagine that two robot rovers embark on cross-country rambles across Mars, scrutinizing rocks for signs of past water on the now-arid world. A flagship spacecraft brakes into orbit at Saturn to begin longterm surveillance of the ringed world, preparing to drop a sophisticated probe to the surface of its haze-shrouded largest moon. Another craft makes the closest-ever pass by the nucleus of a comet, collecting sample particles as it goes. Two new space telescopes peer into the depths of the universe far beyond our solar system, viewing stars, nebulas and galaxies in invisible light beyond the spectrum our eyes can see. A pair of instruments is lofted on a NASA Earth-orbiting satellite to monitor air quality and the protective layer of ozone blanketing our home planet. A small probe brings samples of the solar wind to Earth for in-depth study. While JPL was absorbed with all of these ventures on other worlds, NASA and the White House unveiled an ambitious new plan of space exploration. The Vision for Space Exploration announced in January foresees a program of robotic and astronaut missions leading to a human return to the Moon by 2020, and eventual crewed expeditions to Mars. The vision also calls for more robotic missions to the moons of the outer planets; spaceborne observatories that will search for Earth-like planets around other stars and explore the formation and evolution of the universe; and continued study of our home planet. In order to accomplish all of this, NASA must perfect many as-yet-uninvented technologies and space transportation capabilities. JPL has a great deal to bring to this vision. Robotic exploration of Mars will lead the way for missions that will carry women and men to the red

Ophiolites in ocean-continent transitions: From the Steinmann Trinity to sea-floor spreading

NASA Astrophysics Data System (ADS)

Bernoulli, Daniel; Jenkyns, Hugh C.

2009-05-01

ophiolites as ocean crust is apparent. Between 1920 and 1930, the stage was thus potentially set for modern mobilist concepts that were, however, to prove attractive to only a small circle of Alpine and peri-Gondwanian geologists. After the Second World War, the 1950s saw the rapid progress of the geophysical and geological exploration of oceans and continental margins that provided the data for a reevaluation of the geosynclinal concept. Actualistic models now equated the former preorogenic miogeosyncline of Stille (1940) and Kay (1951) with passive continental margins [C.L. Drake, M. Ewing, G.H. Sutton, Continental margin and geosynclines: the east coast of North America, north of Cape Hatteras, in: L. Ahrens, et al. (Eds.), Physics and Chemistry of the Earth 3, Pergamon Press, London, 1959, pp. 110-189], the (American version of the) eugeosyncline and its igneous rocks with "collapsing continental rises" [R.S. Dietz, J. Geol. 71 (1963) 314-333] and the ophiolites, the Steinmann Trinity, of the (European) eugeosyncline with fragments of oceanic lithosphere [H.H. Hess, History of ocean basins, in: Petrologic Studies: a Volume to Honor A.F. Buddington, Geol. Soc. Am., New York. 1962, pp. 599-620]. The concept of sea-floor spreading [H.H. Hess, History of ocean basins, in: Petrologic Studies: a Volume to Honor A.F. Buddington, Geol. Soc. Am., New York. 1962, pp. 599-620; H.H. Hess, Mid-oceanic ridges and tectonics of the sea-floor, in: W.F. Whittard, R. Bradshaw (Eds), Submarine Geology and Geophysics, Colston Papers 17, Butterworths, London, 1965, pp. 317-333] finally eliminated the weaknesses in Wegener's hypothesis and, with the coming of the "annus mirabilis" of 1968, the concept of the geosyncline could be laid to rest. Ocean-continent transitions of modern oceans, as revealed by seismology and deep-sea drilling, could now be compared with the remnants of their ancient counterparts preserved in the Alps and elsewhere.

PREFACE: First Latin-American Conference on Bioimpedance (CLABIO 2012)

NASA Astrophysics Data System (ADS)

Bertemes Filho, Pedro

2012-12-01

. In making this conference possible, we want to acknowledge our deep appreciation for the financial support of FAPESC (Foundation for Research and Innovation of Santa Catarina), CAPES (Coordination for the Improvement of Higher Level -or Education- Personnel) and also express our sincere thanks to the many individuals who contributed their time and diligence to making this conference possible. Our special thanks go to the Santa Catarina State University for contributing time and effort to organizing the conference. We also wish to express our thanks to Professors Ana Watanabe and Fabricio Noveletto for helping with the registration process, the conference desk and the diverse and sundry details that are the part of any event of this kind. We would like also to thank all of the invited speakers and the members of the Program Committee, and wopuld like to express our gratitude to the Technological Institute of Joinville (FITEJ) for their technical co-sponsorship. We very much appreciate Orjan Martinsen, Uwe Pliquett, Fernando Martinez Seoane, Raul Gonzalez Lima, Marcio Nogueira de Souza and Carlos Augusto Gonzalez Correa for delivering keynote talks at the conference. And we would like to extend an enthusiastic round of thanks to all of our conference authors for their excellent contributions; to all the session chairs for their effort and enthusiasm; and to all the International Program Committee members and referees for their time and expertise in the paper review. Particular thanks go to Emiliano Amarante Veiga and other members of the CLABIO2012 Secretariat and organizing team for their time and outstanding work. List of committees General Chair Professor Pedro Bertemes Filho (Santa Catarina State University) Pedro Bertemes Filho Technical Program Chairs Dr Marcio Nogueira de Souza (Rio de Janeiro Federal University) Local Arrangement Chair Professor Aleksander Paterno (Santa Catarina State University) Professor Fabrício Noveletto (Santa Catarina State University

EDITORIAL: Quanta and leaps

NASA Astrophysics Data System (ADS)

Dobson, Ken

2000-11-01

On Sunday 7 October 1900 Herr Doktor Heinrich Rubens and his wife dropped in on the Planck's Berlin household for tea and some (inevitable) shop-talk. Rubens and his colleague Ferdinand Kurlbaum had been working on an experimental project dear to Max Planck's heart: the variation of intensity with frequency of the radiation from hot objects. They had developed state-of-the-art techniques for taking measurements in the infrared, and Rubens outlined their latest results, due to be presented to the Prussian Academy on 25 October. Between teatime and suppertime Planck had deduced the final version of the radiation law. He was able to work so quickly because he had been working on the problem of reconciling the obviously incomplete Rayleigh law - and various other versions - for many years. The new data confirmed his fairly ad hoc reconciliation of electromagnetic theory and statistical thermodynamics and he sent the outline of his new relationship to Rubens by postcard the same evening. Almost as quick as an e-mail. This itself was a highly important step forward in physics - but what was really outstanding and original was yet to follow, after `a few weeks of the most strenuous work of my life', said the 42 year-old Planck. He realized the significance of his work: `Today I have made a discovery as important as that of Newton,' he confided to his son. This was his based on his determination to find a physical meaning for what had started off as `fictional' mathematical aids to help him derive his formula. The logic compelled him, somewhat reluctantly it appears, to accept that the vibrating objects in a hot body responsible for the oscillating electromagnetic waves they emitted could change in energy only by small discrete amounts: energy packets (quanta) of a size linked to frequency by the relationship E = hf. Not many people took a lot of notice of all this. One did - the obscure Albert Einstein who generalized it in his annus mirabilis 1905 to show that the

BOOK REVIEW: Einstein's Jury: The Race to Test Relativity

NASA Astrophysics Data System (ADS)

Ehlers, Jürgen

2007-10-01

'I know very well that my theory rests on a shaky foundation. What attracts me to it is that it leads to consequences that seem to be accessible to experiment, and it provides a starting point for the theoretical understanding of gravitation', wrote Einstein in 1911. Einstein's Jury by Jeffrey Crelinsten—well documented, well written, and fascinating to read—describes how, from 1909 on, Einstein's two theories of relativity became known to astronomers, and how the predictions made between 1907 and 1915 were received as challenges to observers. The author gives a non-technical account of the efforts made until 1930 to test these predictions; he focuses on two of the three classical tests, namely gravitational redshift and bending of light; the 'jury' consists mainly of American observers—Adams, Campbell, Curtis, Hale, Perrin, St John, Trumpler and others—working with newly built large telescopes, and the Britons Eddington and Evershed. The major steps which, after a long struggle, convinced the majority of astronomers that Einstein was right, are narrated chronologically in rather great detail, especially the work at Lick Observatory, before and after the famous British observation of 1919, on solar eclipses, and the work at Mount Wilson and the Indian Kodaikanal Observatories to extract the gravitational redshift from the complicated spectrum of the sun. The account of the eclipse work which was carried out between 1918 and 1923 by Lick astronomers corrects the impression suggested by many historical accounts that the British expedition alone settled the light-bending question. Apart from these main topics, the anomalous perihelion advance of Mercury and the ether problem are covered. By concentrating on astronomy rather than on physics this book complements the rich but repetitive literature on Einstein and relativity which appeared in connection with the commemoration of Einstein's annus mirabilis, 2005. The well told stories include curiosities such as

Obituary: William Gordon (1918-2010)

NASA Astrophysics Data System (ADS)

Terzian, Yervant

2011-12-01

atmospheric section to investigate the changes in the physical parameters of the ionosphere. Bill Gordon, in 1966, moved to Rice University in Houston, Texas, where he was a Distinguished Professor and Senior Administrator (Dean, Provost and Vice President). The Arecibo Ionospheric Observatory in 1970 was designated as 'The National Astronomy and Ionosphere Center' (NAIC), and began to be funded as a National Center by the National Science Foundation. Cornell has remained the managing institution since that time. Early in the 1970s a grant from the NSF made it possible to replace the surface of the telescope with perforated rigid panels allowing it to operate at least up to 5000 MHz. In the 1990s the long imperfect line feeds were replaced by a complex Gregorian system that greatly increased the sensitivity of the telescope. This allowed the radiation to be collected at a focal point rather than via a long line. These and other major improvements have kept the telescope as the most sensitive radio/radar telescope in the world. Observations of pulsars at Arecibo resulted in the 1993 Nobel Prize in Physics to Joseph Taylor and Russell Hulse who indirectly showed that gravitational waves exist, as Albert Einstein's general theory of relativity predicts. In 1990 Aleksander Wolszczan discovered a special pulsar and he was able to show that it was surrounded by earth size planets. The exotic and photogenic giant radar/radio telescope has also been featured in prominent movies such as the James Bond 'Golden Eye' in 1995, and Carl Sagan's 'Contact' in 1997. Bill's many graduate students from Cornell and Rice, simply adored him. One of his students, Dr. Richard A. Behnke, has said 'Simply he was the greatest man I have known'. Bill was married to Elva Freile Gordon for 61 years. Elva died in 2001. Bill later remarried with Elizabeth Bolgiano Gordon. In his career Bill received many awards. He was a member of the National Academy of Sciences and the National Academy of Engineering, and

BOOK REVIEW: A Student's Guide to Einstein's Major Papers A Student's Guide to Einstein's Major Papers

NASA Astrophysics Data System (ADS)

Janssen, Michel

2013-12-01

The core of this volume is formed by four chapters (2-5) with detailed reconstructions of the arguments and derivations in four of Einstein's most important papers, the three main papers of his annus mirabilis 1905 (on the light quantum, Brownian motion, and special relativity) and his first systematic exposition of general relativity of 1916. The derivations are given in sufficient detail and in sufficiently modernized notation (without any serious distortion of the originals) for an undergraduate physics major to read and understand them with far less effort than it would take him or her to understand (English translations of) Einstein's original papers. Each of these four papers is accompanied by a detailed introduction, which covers the conceptual development of the relevant field prior to Einstein's contribution to it and corrects some of the myths surrounding these papers that still have not been fully eradicated among physicists. (One quibble: though Kennedy correctly points out that the goal of the light quantum paper was not to explain the photoelectric effect, it is also not quite right to say that 'it was written to explain the Wien region of blackbody radiation' (p. xv). Einstein used this explanatory feat as the central argument for his light quantum hypothesis.) These four chapters then are the most valuable part of the volume. They could be used, independently of one another, but preferably in conjunction with Einstein's original texts, in courses on quantum mechanics, statistical mechanics, electrodynamics, and general relativity, respectively, to add a historical component to such courses. As a historian of science embedded in a physics department who is regularly called upon to give guest lectures in such courses on the history of their subjects, I can highly recommend the volume for this purpose. However, I would not adopt this volume as (one of) the central text(s) for a course on the history of modern physics. For one thing, chapter 1, which in