bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of rare earth elements in tomato plants by inductively coupled plasma mass spectrometry techniques
Authors: Spalla S. , Baffi C. , Barbante C. , Turretta C. , Cozzi G. , Beone G. M. , Bettinelli M.
Published: September 2009

In recent years identification of the geographical origin of food has grown more important as consumers have become interested in knowing the provenance of the food that they purchase and eat. Certification schemes and labels have thus been developed to protect consumers and genuine producers from the improper use of popular brand names or renowned geographical origins. As the tomato is one of the major components of what is considered to be the healthy Mediterranean diet, it is important to be able to determine the geographical origin of tomatoes and tomato‐based products such as tomato sauce. The aim of this work is to develop an analytical method to determine rare earth elements (RRE) for the control of the geographic origin of tomatoes. The content of REE in tomato plant samples collected from an agricultural area in Piacenza, Italy, was determined, using four different digestion procedures with and without HF. Microwave dissolution with HNO3 + H2O2 proved to be the most suitable digestion procedure. Inductively coupled plasma quadrupole mass spectrometry (ICPQMS) and inductively coupled plasma sector field plasma mass spectrometry (ICPSFMS) instruments, both coupled with a desolvation system, were used to determine the REE in tomato plants in two different laboratories. A matched calibration curve method was used for the quantification of the analytes. The detection limits (MDLs) of the method ranged from 0.03 ng g−1 for Ho, Tm, and Lu to 2 ng g−1 for La and Ce. The precision, in terms of relative standard deviation on six replicates, was good, with values ranging, on average, from 6.0% for LREE (light rare earth elements) to 16.5% for HREE (heavy rare earth elements). These detection limits allowed the determination of the very low concentrations of REE present in tomato berries. For the concentrations of REE in tomato plants, the following trend was observed: roots > leaves > stems > berries. Copyright © 2009 John Wiley & Sons, Ltd.
Extending matrix‐assisted laser desorption/ionization triple quadrupole mass spectrometry enzyme screening assays to targets with small molecule substrates
Authors: Rathore Rakesh , Corr Jay J. , Lebre Daniel T. , Seibel William L. , Greis Kenneth D.
Published: September 2009

Mass spectrometry (MS)‐based high‐throughput screening (HTS) has tremendous potential as an alternative to current screening methods due to its speed, sensitivity, reproducibility and label‐free readout. We recently reported that a new generation matrix‐assisted laser desorption/ionization triple quadrupole (MALDI‐QqQ) mass spectrometer is ideally suited for a variety of enzyme assays and screening protocols. However, all the targets measured to date had peptide substrates that were easily monitored by selected ion monitoring (SIM) without interference from the MALDI matrix. To further extend the application to enzymes with small molecule, non‐peptide substrates, we evaluated this method for measuring enzyme activity and inhibition of acetylcholinesterase (AChE). Due to the potential of MALDI matrix interference, multiple reaction monitoring (MRM) was investigated for selective MS/MS transitions and to accurately measure the conversion of acetylcholine into choline. Importantly, ionization, detection and MRM transition efficiency differences between the substrate and product can be overcome by pre‐balancing the MRM transitions during method development, thus allowing for a direct readout of the enzyme activity using the ratio of the substrate and product signals. Further validation of the assay showed accurate concentration‐dependent inhibition measurements of AChE with several known inhibitors. Finally, a small library of 1008 drug‐like compounds was screened at a single dose (10 µM) and the top 10 inhibitors from this primary screen were validated in a secondary screen to determine the rank order of inhibitory potency for each compound. Collectively, these data demonstrate that a MALDI‐QqQMS‐based readout platform is amenable to measuring small molecule substrates and products and offers significant advantages over current HTS methods in terms of speed, sensitivity, reproducibility and reagent costs. Copyright © 2009 John Wiley & Sons, Ltd.
Molecular depth profiling of multilayer structures of organic semiconductor materials by secondary ion mass spectrometry with large argon cluster ion beams
Authors: Ninomiya Satoshi , Ichiki Kazuya , Yamada Hideaki , Nakata Yoshihiko , Seki Toshio , Aoki Takaaki , Matsuo Jiro
Published: September 2009

In this study, we present molecular depth profiling of multilayer structures composed of organic semiconductor materials such as tris(8‐hydroxyquinoline)aluminum (Alq3) and 4,4′‐bis[N‐(1‐naphthyl)‐N‐phenylamino]biphenyl (NPD). Molecular ions produced from Alq3 and NPD were measured by linear‐type time‐of‐flight (TOF) mass spectrometry under 5.5 keV Ar700 ion bombardment. The organic multilayer films were analyzed and etched with large Ar cluster ion beams, and the interfaces between the organic layers were clearly distinguished. The effect of temperature on the diffusion of these materials was also investigated by the depth profiling analysis with Ar cluster ion beams. The thermal diffusion behavior was found to depend on the specific materials, and the diffusion of Alq3 molecules was observed to start at a lower temperature than that of NPD molecules. These results prove the great potential of large gas cluster ion beams for molecular depth profiling of organic multilayer samples. Copyright © 2009 John Wiley & Sons, Ltd.
Atmospheric pressure thermospray ionization using a heated microchip nebulizer
Authors: Keski‐Rahkonen Pekka , Haapala Markus , Saarela Ville , Franssila Sami , Kotiaho Tapio , Kostiainen Risto , Auriola Seppo
Published: September 2009

When a standard atmospheric pressure chemical ionization (APCI) or atmospheric pressure photoionization (APPI) ion source is used without applying the corona discharge or photoirradiation, atmospheric pressure thermospray ionization (APTSI) of various compounds can be achieved. Although largely ignored, this phenomenon has recently gained interest as an alternative ionization technique. In this study, this technique is performed for the first time on a miniaturized scale using a microchip nebulizer. Sample ionization with the presented microchip‐APTSI (µAPTSI) is achieved by applying only heat and gas flow to a nebulizer chip, without any other methods to promote gas‐phase ionization. To evaluate the performance of the described µAPTSI setup, ionization efficiency for a set of test compounds was monitored as the microchip positioning, temperature, nebulizer gas flow rate, sample solution composition, and solvent flow rate were varied. The µAPTSI mass spectra of the test compounds were also compared to those obtained with ESI and APCI. The µAPTSI produces ESI‐like spectra with low background noise, favoring the formation of protonated or deprotonated molecules of compounds that are ionizable in solution. Multiple charging of peptides without in‐source fragmentation was also observed. Unlike ESI, however, the µAPTSI source can tolerate the presence of mobile phase additives like trifluoroacetic acid (TFA) without significant ion suppression. The µAPTSI source can be used with standard mass spectrometer ion source hardware, being a unique alternative to the present interfacing techniques. Copyright © 2009 John Wiley & Sons, Ltd.
Functionalized pyrolytic highly oriented graphite polymer film for surface‐assisted laser desorption/ionization mass spectrometry in environmental analysis
Authors: Kawasaki Hideya , Takahashi Naoyuki , Fujimori Hiroki , Okumura Kouji , Watanabe Takehiro , Matsumura Chisato , Takemine Syusuke , Nakano Takeshi , Arakawa Ryuichi
Published: September 2009

The pyrolytic highly oriented graphite polymer film (PGS) was first employed to analyze low‐mass analytes in environmental analysis by surface‐assisted laser desorption/ionization mass spectrometry (SALDI‐MS). PGS is a synthetic uniform and highly oriented graphite polymer film with high thermal anisotropic conductivity. We have found that negative ion mode SALDI‐MS using oxidized PGS (PGS‐SALDI‐MS) can be used to detect [M–H]− ions from perfluorooctanoic acid (PFOA) and other perfluoroalkylcarboxylic acids when the PGS surface is modified with the cationic polymer polyethyleneimine (PEI). The signal intensity of PFOA when employing the PEI modification showed a ten‐fold increase over that obtained from desorption/ionization on porous silicon (DIOS). PFOA was quantified using PGS‐SALDI‐MS and the calibration curve showed a wide linear dynamic range of response (20–1000 ppb). The combination of atmospheric pressure ionization and PGS (AP‐PGS‐SALDI) showed greater signal intensity than vacuum PGS‐SALDI for deprotonated PFOA. Several other environmentally important chemicals, including perfluoroalkylsulfonic acid, pentachlorophenol, bisphenol A, 4‐hydroxy‐2‐chlorobiphenyl, and benzo[a]pyrene, were also successfully used to evaluate PGS‐SALDI‐MS. In addition, we found that nonafluoro‐1‐butanesulfonic acid was able to produce protonated peptides in positive ion PGS‐SALDI‐MS, but that perfluoropentanoic acid and trifluoroacetic acid were not. It is suggested that perfluoroalkylsulfonic acids are better protonating agents than perfluoroalkylcarboxylic acids in SALDI‐MS. Copyright © 2009 John Wiley & Sons, Ltd.
Advantages of compound‐specific stable isotope measurements over bulk measurements in studies on plant uptake of intact amino acids
Authors: Sauheitl Leopold , Glaser Bruno , Weigelt Alexandra
Published: September 2009

Increasing interest in the ability of plants to take up amino acids has given rise to questions on the accuracy of the commonly used bulk method to measure and calculate amino acid uptake. This method uses bulk measurements of 13C and 15N enrichment in plant tissues after application of dual‐labelled amino acids but some authors have recommended the use of compound‐specific stable isotope (CSI) analysis of the plants' amino acids instead. However, there has never been a direct evaluation of both methods. We conducted a field study applying dual‐labelled (13C, 15N) amino acids (glycine, valine, tyrosine and lysine) to soil of a Plantago lanceolata monoculture. Root and shoot samples were collected 24 h after label application and the isotope composition of the plant tissues was investigated using bulk and CSI measurements. Enrichment of 13C in the case of CSI measurements was limited to the applied amino acids, showing that no additional 13C had been incorporated into the plants' amino acid pool via the uptake of tracer‐derived C‐fragments. Compared with this rather conservative indicator of amino acid uptake, the 13C enrichment of bulk measurements was 8, 5, 1.6 and 6 times higher for fine roots, storage roots, shoot and the whole plant, respectively. These findings show that the additional uptake of tracer‐derived C‐fragments will result in a considerable overestimation of amino acid uptake in the case of bulk measurements. We therefore highly recommend the use of CSI measurements for future amino acid uptake studies due to their higher accuracy. Copyright © 2009 John Wiley & Sons, Ltd.
Development of a new electron ionization/field ionization ion source for gas chromatography/time‐of‐flight mass spectrometry
Authors: Miyamoto Kenji , Fujimaki Susumu , Ueda Yoshihisa
Published: September 2009

We have developed a combined EI/FI source for gas chromatography/orthogonal acceleration time‐of‐flight mass spectrometry (GC/oaTOFMS). In general, EI (electron ionization) and FI (field ionization) mass spectra are complementary: the EI mass spectrum contains information about fragment ions, while the FI mass spectrum contains information about molecular ions. Thus, the comparative study of EI and FI mass spectra is useful for GC/MS analyses. Unlike the conventional ion sources for FI and EI measurements, the newly developed source can be used for both measurements without breaking the ion source vacuum or changing the ion source. Therefore, the combined EI/FI source is more preferable than the conventional EI or FI ion source from the viewpoint of the reliability of measurements and facility of operation.

Using the combined EI/FI source, the complementarity between EI and FI mass spectra is demonstrated experimentally with n‐hexadecane (100 pg): characteristic fragment ions for the n‐alkane such as m/z 43, 57, 71, and 85 are obtained in the EI mass spectrum, while only the parent peak of m/z 226 (M+) without any fragment ions is observed in the FI mass spectrum. Moreover, the field desorption (FD) measurement is also demonstrated with poly(ethylene glycol)s M600 (10 ng) and M1000 (15 ng). Signals of [M+H]+, [M+Na]+ and [M+K]+ are clearly detected in the FD mass spectra. Copyright © 2009 John Wiley & Sons, Ltd.
Perceptions and determinants of environmental concern: the case of Hong Kong and its implications for sustainable development
Authors: Wong Timothy Ka‐ying , Wan Po‐san
Published: September 2009

Environmental concern is a precursor to behavioural change. This article draws upon data from two surveys conducted in 2000 and 2008 to examine the development of environmental concern in Hong Kong and its major determinants. It finds that Hong Kong people have consistently shown a high level of environmental concern in terms of both their perception of the seriousness of environmental problems and their assessment of how these problems will develop in the future. In line with previous findings, our study confirms that environmental concern is affected by a combination of positional, individual and institutional factors, including gender, education, pro‐environmental beliefs, especially concern for environmental damage, and the government's performance in environmental protection. Among these factors, government performance is shown to be of crucial importance. Implications for sustainable development are highlighted. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
A regional divide in sustainability performance in China: geography, governance and income
Authors: Liu Lee
Published: September 2009

China had accredited 320 Eco‐Communities and 72 Model Cities by 2009. This paper uses these ‘sustainable places’ and their neighbors to examine spatial variations in sustainability performance and possible causes of such variations. Data were collected through personal interviews of 186 provincial and local environmental officials and researchers, in addition to review of governmental publications. This paper finds a regional divide in sustainability performance between China's Eco‐Provinces and other provinces and between ‘sustainable places’ and other communities. Geography, governance and income are important in understanding the divide. The conventional wisdom following the environmental Kuznets curve (EKC) is inadequate for understanding the regional divide in sustainability performance. Sustainability studies need to be expanded to pay more attention to geography and governance, not just income. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Sooner city: Reflections on a curriculum reform project
Authors: Kolar Randall L. , Sabatini David A. , Muraleetharan K. K.
Published: September 2009

This chapter describes an engineering curriculum reform effort that threads a common four‐year design theme across multiple courses within the curriculum.
Low Energy Monopropellants Based on the Guanylurea Cation
Authors: Klapötke Thomas M. , Miró Sabaté Carlos
Published: September 2009

Reaction of cyanoguanidine (3) with hydrochloric, sulfuric, nitric or perchloric acids yielded guanylurea chloride (4), sulfate (5), nitrate (6) and perchlorate (7). Compounds 4 and 5 reacted further to form a new family of energetic salts based on the guanylurea cation and azide (8a), 5‐nitrotetrazolate (9), 5‐aminotetrazolate (10), picrate (11) and 5,5′‐azotetrazolate (12a) anions. The water of hydration in compounds 8a and 12a was eliminated by heating under vacuum yielding the anhydrous salts 8b and 12b. All materials were characterized by means of elemental analysis, mass spectrometry (MS) as well as vibrational (IR, Raman) and NMR (1H, 13C, 14/15N and 35Cl) spectroscopy. Additionally, the crystal structures of 4, 7, 8a and 10 were determined by low temperature X‐ray measurements (4, 7 and 8a: Monoclinic, P21/c; 10: Monoclinic, P21). The thermal behavior of 6–12 was assessed by DSC measurements and their heats of formation were calculated on the basis of the electronic energies of the ions using the MP2 method. In addition, the sensitivity to shock, friction and electrostatic discharge of all materials was measured by submitting the compounds to standard (BAM) tests. The detonation pressures (P) and velocities (D) were calculated from the energies of formation using the EXPLO5 code (6: P = 17.4 GPa, D = 7004 m·s–1; 8a: P = 20.6 GPa, D = 7880 m·s–1; 8b: P = 16.9 GPa, D = 7289 m·s–1; 9: P = 20.3 GPa, D = 7439 m·s–1; 10: P = 18.4 GPa, D = 7530 m·s–1; 11: P = 19.7 GPa, D = 7152 m·s–1; 12a: P = 24.3 GPa, D = 8222 m·s–1 and 7: P = 23.3 GPa, D = 8115 m·s–1). Lastly, the long term stability of 12a was assessed and the ICT code was used to predict the decomposition gases. Most materials decompose giving large amount of environmentally friendly gases and their performance values classify them as new insensitive low‐energy monopropellants.
Liver transplantation for hepatocellular carcinoma: current topics in France
Authors: Scatton Olivier , Liddo Guido , Belghiti Jacques
Published: September 2009

Background

Excellent survival obtained with liver transplantation (LT) for limited hepatocellular carcinoma (HCC) in patients with chronic liver disease is still challenged by the increasing discrepancy between candidates and grafts available. We review the current strategy of LT for HCC in our country highlighting the tendency: (1) to expand recipient selection beyond the Milan criteria, (2) to use systematic pre‐LT treatments with a greater number of resections and (3) new rules for graft attribution.

Results

Although the vast majority of cirrhotic patients with HCC are transplanted within the Milan criteria; the number of candidates is continually rising, while the number of grafts available is stable with a disappearance of adult LDLTs. Moreover, the new rules for organ allocations, mainly based on the MELD score, minimize the accessibility to liver grafts for patients with HCC and compensated liver disease. For these reasons, in France we have observed an increase in waiting time for HCC patients, leading to the extensive use of pre‐LT treatments in order to limit the list dropouts. Many studies have been performed on transarterial chemo‐embolization (TACE) and supraselective TACE. Moreover, the use of liver resection (LR) as a bridge therapy, showing that initial resection does not impair short‐ and long‐term survival, led French surgeons to develop the concept of LR as a way to select patients who might benefit from LT and to use it, in selected cases, as a primary therapy, considering LT as salvage treatment in case of recurrence.

Conclusions

The number of HCC candidates who cannot benefit from a LT is increasing worldwide. The French answer to this situation involves pre‐LT treatments, particularly partial LR, based mainly on the excellent Japanese results in this field. Moreover, the country of « égalité » is actually modifying the rules of graft attribution in order to reduce the inequality between the HCC patients with poor and good liver function.
Liver transplantation for hepatocellular carcinoma in the world: the Taiwan experience
Authors: Chen Chao‐Long , Concejero Allan M.
Published: September 2009

Liver transplantation (LT) has been regarded as “potentially curative” in a cirrhotic patient with hepatocellular carcinoma (HCC) because it removes the cancer and eradicates the cirrhosis. In Taiwan, HCC ranks first among the leading causes of cancer mortality in males and 4th in females. The most common causes are chronic hepatitis B virus‐related cirrhosis, hepatitis C virus‐related cirrhosis, and combined hepatitis B and C virus‐related cirrhosis. The aggregate lifetime cost of hepatitis and HCC constitutes a significant burden on the Taiwanese health‐care system. The reported overall (living‐donor LT and deceased donor LT) 1‐ and 3‐year survival rates for HCC after LT in Taiwan ranged from 86 to 98% and 61 to 96%, respectively. Microscopic vascular invasion did not influence the outcome of patients, but high alpha‐fetoprotein levels >200 ng/ml may be a risk factor for HCC recurrence after transplant.
An unusual presentation of a ruptured abdominal aortic aneurysm
Authors: Abdel Aziz Adel , Maskery Nick
Published: September 2009

The diagnosis of ruptured abdominal aortic aneurysm (AAA) is often missed as a result of an unusual presentation, resulting in increased mortality. Here, we present an atypical presentation of ruptured AAA in a 72-year-old healthy male who had brief episode of syncope from which he fully recovered. A high index of clinical suspicion of ruptured AAA should be maintained in elderly patients presenting with history of syncope.
Exploring the relevance of expressed emotion to the treatment of social anxiety disorder in adolescence
Authors: Garcia‐Lopez Luis‐Joaquin , Muela Jose M. , Espinosa‐Fernandez Lourdes , Diaz‐Castela Mar
Published: September 2009

The role that the involvement of parents may play in the treatment outcome of their children with anxiety disorders is still under debate. Some studies dealing with other disorders have examined the role that the expressed emotion (EE) construct (parental overinvolvement, criticism and hostility) may play in treatment outcome and relapse. Given that some of these aspects have been associated with social anxiety for a long time, it was hypothesized that EE may be associated with lower treatment outcome. The sample was composed of 16 adolescents who benefited from a school‐based, cognitive‐behavioural intervention aimed at overcoming social anxiety. Then, parents were classified with high or low EE. The results revealed that the adolescents whose parents had low EE showed a statistically significant reduction of their social anxiety scores at posttest, as opposed to adolescents of parents with high expressed emotion. These findings suggest that parental psychopathology (parents with high EE) should be taken into consideration to prevent poor adolescent treatment outcome.
Nucleoside diphosphate kinase‐1 regulates hyphal development via the transcriptional regulation of catalase in Neurospora crassa
Authors: Lee Bumkyu , Yoshida Yusuke , Hasunuma Kohji
Published: September 2009

A nucleoside diphosphate kinase‐1‐disrupted (ndk‐1RIP‐1
) mutant was observed to be defective in aerial hyphal and conidial development. In this study, two types of hyphae, fine and thick, were observed in wild‐type (Wt) strains. However, only fine‐type hyphae were observed in the ndk‐1RIP‐1
mutants. The ndk‐1RIP‐1
mutants were stimulated by oxidative stress and constitutively expressed an antioxidant enzyme catalase (CAT)‐3. Furthermore the ndk‐1RIP‐1
mutants could form thick hyphae by oxidative stress and a disruption of cat‐3. These results suggest that the loss of thick hyphae in the ndk‐1RIP‐1
mutants may be caused by the over‐expression of cat‐3.
Conquering the Past: Post-War Archaeology and Nationalism in the Borderlands of Chile and Peru, c. 1880–1920
Authors: Gänger Stefanie
Published: September 2009

In 1899, Chilean workers discovered the mummified body of a woman in a copper mine in Chuquicamata, in the Atacama Desert. Chile's most prominent archaeologists were called to examine the body and they estimated it had been in the mine for more than four centuries. What most astonished both the public and the scholarly community was that the body had been preserved virtually intact, apparently by nothing but the environmental conditions surrounding it. José Toribio Medina, a central figure in Chilean archaeology at the time, discussed this finding in 1901:

Natural causes account for the mummy of Chuquicamata. The body is that of a female. The depth of the soil where the corpse was found was no more than six to eight feet, and the miner was probably searching the mountain when a sudden collapse buried her. The miner, feeling that the mountain was breaking down, lifted her arms up to protect her head, the position in which her body is preserved. … In some parts of the body, especially the arms, the difference between the injured and the intact parts of the skin can even be distinguished, to the point where it seems almost that blood is flowing from the wounds. In her face, hidden between her arms, her contracted mouth is visible… .1
The Traveling Panopticon: Labor Institutions and Labor Practices in Russia and Britain in the Eighteenth and Nineteenth Centuries
Authors: Stanziani Alessandro
Published: September 2009

Between 1780 and 1787 Samuel and Jeremy Bentham were asked to manage a large Russian estate owned by Prince Grigorii Potemkin, one of the closest advisors of Catherine II. They had to face two related but distinct problems: Russian peasants were unskilled, while British skilled workers and supervisors were hard to control. It was the problem of controlling skilled English workers in Russia (and not the Russian serfs) that led the Bentham brothers to reflect on the relation between free and forced labor, and then between labor and society. Before and after Foucault, the Panopticon has been seen as a response to social deviance, and in relation to prisons and the emergence of a global surveillance system in modern societies. According to Foucault, the Panopticon is not just a model for institutions, but something whose principles are those of power in society at large. I want to challenge this view by arguing that the Panopticon project actually was a system for controlling wage labor, which drew inspiration from a particular image of Russian serfdom and from the Bentham brothers' experiences in that country. Those experiences have been the subject of several papers and books. The first aim of this paper is not to recall these, but rather to integrate them into a broader intellectual debate. In particular, I will evoke the origins of the Benthams' experiences in Russian, British, and European debates of the period about the legal status of labor. The way that “western” thought conceived of labor in general and positioned itself vis-à-vis Russia necessitates a reexamination of the thesis that the principal schools of western thought were misunderstood in Russia. I will argue, instead, that Russian authors and reformers relied on ambiguities in western thinking about labor when they advanced their own images of serfdom and proposals for reform.
Malthus'Essay on Populationand the American Debate over Slavery
Authors: Hodgson Dennis
Published: September 2009

Malthus published hisEssay on Populationin 1798 and for the next century, as the new discipline of political economy incorporated his thought into its central tenets, population theorizing took place largely within a Malthusian framework. A stark simplicity marks his argument, especially as presented in the succinct first edition of the essay. He presents the reader with two self-evident natural laws: “that food is necessary to the existence of man,” and “that the passion between the sexes is necessary and will remain nearly in its present state” (1798: 11). He then observes, “The power of population is indefinitely greater than the power in the earth to produce subsistence for man” (13), and contends that population, when unchecked, increases in a “geometrical ratio” while subsistence in only an “arithmetical ratio” (14). In this first edition, Malthus had the particular ideological goal of proving that “the advocates of equality and of the perfectibility of man” had an unattainable dream. Mr. Godwin could imagine a British Isle where all are equal, live in “airy” farmhouses, share “the necessary labours of agriculture” (182), and divide its fruits “according to their wants,” Malthus observed, but such a regime places no barrier to early marriage and large families. He calculated that in a hundred years the Isle's seven million people “would be one hundred and twelve millions, and the food only sufficient for thirty-five millions, leaving seventy-seven millions unprovided for” (23–24). Since “no possible form of society could prevent the almost constant action of misery upon a great part of mankind” (36), constructing a society of equals only ensures a society in which all will be poor. Any attempt to improve the conditions of the impoverished by granting them access to subsistence, such as the poor laws then in effect in England, simply works “in some measure to create the poor which they maintain” since they permit the poor man to “marry with little or no prospect of being able to support a family in independence” (83).
Localized negative interference and its bearing on models of gene recombination
Authors: Pritchard R. H.
Published: September 2009

In the analysis of recombination inAspergillus nidulanscoincidence values of about 1 are found in 3-point tests using markers more than a few map units apart. In comparable tests in which the marked intervals were very short (0·1 map unit or less), coincidence values of over 100 had been found. To account for this difference it was proposed that a necessary condition for recombination, termed ‘effective pairing’, was realized at any particular point on the chromosome in only a small fraction of a population of cells at meiosis. It was supposed that when effective pairing occurred it extended over a very short segment of the chromosome and that the probability of recombination in the effectively paired segment was high, i.e. about 1. Coincidence values greater than unity would be a necessary consequence of such a situation provided the intervals in question had a total length not much greater than that of effective pairing segments.

The experiments described in this paper were undertaken in an attempt to measure the mean length of effectively paired segments, their distribution, and the frequency of exchange within them. The data suggest a mean length of about 0·4 map unit, a mean exchange frequency of about 0·6, and a distribution which is variable, perhaps random.

The occurrence of localized negative interference suggests a way in which a number of difficulties encountered in relating the experimental evidence concerning the time and mechanism of recombination with the cytological evidence concerning the sequence of events at meiosis might be resolved. The data indicate that the frequency of recombination between linked loci is a measure principally of the frequency of effective pairing between them. If effective pairing is synonymous with homologous contact between chromosomes, and evidence is presented which suggests this may be the case, it becomes possible to construct a simple model which is compatible with the view that recombination takes place before chromosomes are paired, in the cytologically observable sense (i.e. before zygotene), at meiosis.

The recombination events occurring within effectively paired regions are generally, although possibly not exclusively, reciprocal. Non-reciprocal recombinants have been encountered inAspergillusand other organisms, characterized by the occurrence of 3:1 ratios in tetrads. On the basis of evidence currently available it does not seem necessary to invoke a special mechanism of recombination, distinct from crossing over, to account for the formation of non-reciprocal recombinaiits. A single mechanism of recombination of the copy-choice type which, although primarily a reciprocal process, is nevertheless not necessarily exactly so or always so in detail, will account for the observed results.
Antigenic polymorphism in a wild population of Paramecium aurelia
Authors: Pringle C. R. , Beale G. H.
Published: September 2009

1. A population of Paramecium aurelia, syngen 9, in Blackford Pond, Edinburgh, has been sampled over a period of 6 years and the types of immobilization antigen present identified.

2. Three antigen-determining alleles at the G locus and six alleles at the X locus were found.

3. No significant changes in relative numbers of the various alleles were apparent over the period studied, nor was there any difference between opposite ends of the pond.

4. An appreciable proportion of G-type heterozygotes was found, but the numbers were significantly less than would be expected by random mating alone. Autogamy is presumed to be responsible for this deficit.

5. Whether there is any natural selection in favour of heterozygotes over homozygotes in unknown. A possible method for obtaining information on this subject is discussed.
Two closely linked genes in the mouse
Authors: Grüneberg H. , Truslove G. M.
Published: September 2009

(1) In heterozygous condition, the gene for Patch (symbolPh) produces spotting with sharply defined pigmented and white areas. The extent of the spotting is under the control of the genetic background.

(2) ThePh/Phhomozygote is inviable and dies before birth. In 9-day embryos, clear liquid is found flanking the notochord; in addition, there may be excessive amounts of liquid in the pericardium, the circulation, the tissues, and under the epidermis. The more extremely affectedPh/Phembryos die at about 10 days. About one-third survive to later stages of pregnancy. Such ‘cleft-face’ embryos have a large bleb of liquid in the middle of the face which interferes mechanically with the formative movements of the nose and palate, and many subepidermal blebs elsewhere.

(3)Phis closely linked to the gene for dominant spotting with macrocytic anaemia (W, Wv) in linkage group III, the crossover percentage being 0·077. There is a striking interaction in the double heterozygotePh+ / +Wvwhich is almost white, but nearly equally striking interactions occur with other spotting genes (s, btandMiwh).

(4) By itself,Phhas no detectable effect on the coat colour, but in the double heterozygote withWv, it slightly increases the dilution effect of the latter in the regions which remain pigmented. Similarly,Phby itself has no appreciable effect on the red-blood picture of 13–14-day-old animals, but in the double heterozygote withWv, it probably slightly increases the mild macrocytic anaemia produced by that gene. It remains unknown whether thePh/Phhomozygote has an effect on the blood. UnlikeW/WandWv/Wv,Ph/Phhas no appreciable effect on the primordial germ cells.

(5) The relationship betweenPhand theW-series is discussed.
Migration of nuclei in Coprinus lagopus
Authors: Swiezynski K. M. , Day P. R.
Published: September 2009

1. Four main types of interaction between paired mycelia of Coprinus lagopus have been defined in terms of the extent of nuclear migration.

2. Nuclear migration was demonstrated in matings between monokaryotic mycelia with common A alleles. No extensive migration of nuclei was found in common B or common AB matings.

3. The speed of nuclear migration in common A matings was slower than in compatible matings. Migration occurred to approximately the same extent in both kinds of matings.

4. In heterokaryon-monokaryon matings compatible and common B heterokaryons acted only as donors. Common AB heterokaryons acted as donors and as acceptors of compatible or common A nuclei. Common A heterokaryons always acted as donors and frequently acted as acceptors of compatible or common A nuclei.

5. A simple explanation is suggested for the frequently observed fact that in an incompatible di-mon mating both nuclei of the dikaryon may migrate and eventually eliminate the nuclei of the established monokaryon.
Experiments on canalizing selection
Authors: Waddington C. H.
Published: September 2009

1. Mutant stocks whose phenotype is affected by temperature were kept at 18° and 25° C., and selection was applied in an attempt to reduce the magnitude of the phenotypic difference caused by the temperatures. The stocks used were Bar, dumpy, cubitus-interruptus and aristopedia-Bridges.

2. When the stocks were kept for one or more generations at one temperature, then transferred for the next generation or two to the other, and so alternately, selection applied against the phenotypic effect of the temperature was only slightly effective in reducing the differences between the high- and low-temperature phenotypes. It is suggested that this was due mainly to the fact that such selection would be expected to operate on quantitatively-acting genes as well as on genes controlling developmental buffering.

3. With family selection, in which the offspring of a pair-mating was divided into two lots, one kept at each temperature, and selection was made on the basis of the differences in family means, progress was rapid. In the unselected Bar stock, the facet number at 18° was initially about three times that at 25°; after six generations of family selection the difference had been reduced to about 10%, the phenotypes at both temperatures being about intermediate between those seen at the beginning of the experiment. With aristopedia the reduction in the difference in family means was also striking, but in this case was achieved by increasing the abnormality of the 25° phenotype, and hardly at all by lowering that of the 18° population. It is pointed out that this is probably the result of an inadequate scoring system.

4. Although the selection in Bar stocks was effective in increasing developmental canalization against external environmental changes (temperature), it had little or no effect on the asymmetry of the facet numbers.
High frequency of a lethal gene (te) in a laboratory stock of mice
Authors: Bateman Nigel
Published: September 2009

A long-established laboratory stock was found to contain many individuals that were heterozygous for a lethal gene, called tailless-Edinburgh (te). Heterozygotes are indistinguishable from normals except by breeding tests with special tester stocks supplying brachyury (T) gametes, when tailless (Tte) progeny distinguish carrier parents from normal parents that produce only short-tailed (T +) progeny. When males are mated to tester females providing brachyury eggs, the ratio of Tte: T + progeny reflects the ratio of te: + spermatozoa. The proportion of te spermatozoa measured in this way led to the expectation that 62% of individuals in the original stock would be carriers, whereas 80% was found. Independent evidence is presented for + te males that the incidence of te in their effective spermatozoa was higher when normal eggs were fertilized in matings within the original stock than when brachyury eggs were fertilized in outcross matings to the tester stock. These observations suggest that the proportion of te spermatozoa partaking in fertilization was modified by the genotypes of the females or of their eggs.
Selective fertilization at the T-locus of the mouse
Authors: Bateman Nigel
Published: September 2009

Advantage was taken of a unique situation to test, with adequate controls, the assertion that male and female gametes conjugate at random. The data concern the aberrant locus T of the mouse, at which there are a number oftalleles that enter into the majority of effective spermatozoa of males heterozygous for one of them. Segregation in females is normal. Evidence is presented for one of thesetalleles, tailless-Edinburgh (te), that conjugation between gametes was not at random when this gene was present in spermatozoa. When a choice of eggs was presented by heterozygous females, tailless-Edinburgh spermatozoa united more frequently with normal than with brachyury eggs and more frequently with brachyury than with tailless-Edinburgh eggs. The relevance of this finding is discussed in relation to expected equilibria oftalleles in closed populations. Other forms of selective fertilization are discussed and their genetic consequences compared.
New evidence of unbalanced sex-chromosome constitutions in the mouse
Authors: McLaren Anne
Published: September 2009

Some anomalous results are described of genetical tests using the sex-linked markers Tabby and Bent-tail. The results are shown to be consistent with the demonstration by Welshons & Russell (1959) that the X/O chromosome constitution is female, and suggest that the condition can arise from non-disjunction in the female as well as from non-disjunction in the male parent. A single animal of presumed X/X/y constitution appeared anatomically to be fully male, but died before breeding test could be performed.
Genetics of resistance to Amphorophora rubi (Kalt.) in the raspberry II. The genes A2–A7 from the American variety, Chief
Authors: Knight R. L. , Briggs J. B. , Keep Elizabeth
Published: September 2009

The American raspberry variety Chief is shown to carry three dominant genes, A5, A6 and A7, each capable of conferring strong resistance to Amphorophora rubi strain 1.

Chief also carries three genes, A2, A3 and A4, for resistance to A. rubi strain 2. A2 is a dominant gene conferring full resistance by itself; A3 and A4 are dominant complementaries, neither gene by itself having any effect on resistance. A5 is linked with either A3 or A4 with a crossover value of 10%.

The gene A1 from Baumforth A, which confers resistance to strains 1 and 3, when combined with A3 gives resistance to strain 2 also. Thus the three strains of A. rubi at present recognized on raspberries in Britain can be controlled by using either the combination A1A2 or A1A3.
Forward and back mutation in thepyr3region of Neurospora. I. Mutations from arginine dependence to prototrophy
Authors: Reissig José L.
Published: September 2009

A system for the screening of reversions in an arginine-dependent strain of Neurospora has been developed.

Reversion resulted from any one of three events:

(a) Back mutation of the originalarggene.

(b) Forward mutation at thepyrlocus. This has the pleiotropic effect of suppressingargwhile determining a pyrimidine requirement. Interaction with the unmutated nuclei of the same conidium permits growth on minimal medium.

(c) Forward mutation at thepyrlocus to alleles of intermediate activity. These alleles suppressarg, but do not create a pyrimidine requirement.
The induction of dominant lethal mutations in rats and mice with triethylenemelamine (TEM)
Authors: Bateman A. J.
Published: September 2009

1. TEM resembles X-rays in inducing dominant lethal mutations in the sperm of rats and mice and sterilizing type B spermatogonia. Beyond this, however, there are several important differences.

2. The relative ease with which TEM and X-rays affect sperm and spermatogonia varies greatly. The X-ray dose which produces 50% dominant lethals in sperm (500 rad) sterilizes spermatocytes and type B spermatogonia, and has such a drastic effect on type A spermatogonia that recovery of fertility is delayed for 2½ months. The TEM dose which produces the same mutation rate in sperm (0·1 mg./kg. rat) has no detectable effect on pre-meiotic stages. Even 1 mg./kg. only sterilizes the most sensitive stage, type B spermatogonia.

3. Taking immature sperm as the standard, mature sperm are more sensitive to X-rays, but less sensitive to TEM, and early spermatids, the most sensitive stage to X-ray-induced dominant lethals, are highly resistant to TEM.

4. Spermatocytes, in which X-rays yield a mutation rate equal to immaturesperm, are highly resistant to TEM.

5. To produce the same mutation rate in immature sperm, mice require twice as much TEM as the rat in mg./kg., though approximately the same X-ray dose.

6. In contrast to mid-stage rat spermatids, which are the most sensitive stage to TEM, mouse mid-stage spermatids are resistant.
The fertility of mice selected for large or small body size
Authors: Fowler Ruth E. , Edwards R. G.
Published: September 2009

The fertility of two unrelated strains of mice (strainsNandC) which had both been selected for large and small body size has been studied.

The fertility of pairs of mice in the large or small lines of strainCwas unimpaired by selection. In strainN, some of the pairs in the large and small lines, but not in the control line, were sterile. Sterility in the large line was due to the low libido of the males, and not to female infertility. Sterility in the small line was probably due to hypo-functioning of the anterior pituitary of some females: the oestrous cycle was delayed or absent, some mice failed to ovulate after mating, and a high proportion of those mating had no implanted embryos at 12 days' gestation. Oestrus and ovulation could be induced in mice of the small line of strainNby exogenous gonadotrophins, and the proportion of mice with implanted embryos was considerably increased by progesterone supplements.

The number of eggs found after natural mating was considerably higher in large mice than in small mice, and was significantly correlated with body weight in the small line of strainConly. The egg-number/body-weight ratio was higher in the lines of strainCthan in those of strainN, though the ratios were similar when carcass fat was subtracted from total body weight.

The amount of endogenous follicle-stimulating hormone secreted by the mice of the five lines was estimated by inducing ovulation with various amounts of exogenous gonadotrophins, and comparing the number of eggs found after each dose with the mean number ovulated after natural mating. Estimates of the amount of follicle-stimulating hormone secreted by mice of strainCwere higher than those for mice of strainN.

Differences in the rates of growth and in the numbers of eggs ovulated after natural mating indicate a higher level of pituitary activity in strainCthan in strainN.
Survey of line crosses in a Brown Leghorn flock 1. Egg Production
Authors: Blyth J. S. S. , Sang J. H.
Published: September 2009

Six isolate lines of long standing, from the Centre's Brown Leghorn flock, were intermated in all possible directions, providing thirty cross and six pure line samples. Half the birds from each line and reciprocal cross were kept in floor pens and the rest caged in an adjacent battery house.

Sexual maturity, survivors' production to 500 days of age, and November through June egg numbers, all showed two main factors contributing to variations in cross performance: (1) a significant association with parental production levels as measured by mid-parent averages, and (2) an additional hybrid gain. For November to June production in pens, this hybrid gain appeared to approach a constant for the cross groups. Additional sources of variation were present in age at sexual maturity.

The 500-day records for the penned hybrids exceeded the line average by 50 eggs. Caged samples did less well and showed an advantage of only 34 eggs. In this location the hybrid gain for individual groups decreased with increases in mid-parent level.

Egg weight varied negatively with egg numbers only in the upper half of the wide egg-size range. The best layers fell at the lower end of the covariant range for egg size.

The importance of improving closed strains may not have been lessened by the expansion of the hybrid side of the poultry industry, for the pattern of relationships of line and cross production in this flock is consistent enough to justify the inference that the best hybrids come from the best-producing parents.
Comparative mutability of wild-type isoalleles at the white loci inDrosophila melanogaster
Authors: Green M. M.
Published: September 2009

1. The X-ray mutability of wild-type isoalleles of thewhite-eyeloci inDrosophila melanogasterhas been determined.

2. No difference in the mutability of the isoalleles was found. However, an appreciable difference in mutation rate of the two halves of thewloci was found.

3. The bearing of these data on the problems of isoallelism and pseudoallelism are discussed.