bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the theory of the unifilar variometer
Authors: Howe H. H. 
Published: February 2008

Vectors are used in this treatment. Neglecting inhomogeneity of the field of control‐magnets, the simple, inclusive equation is obtained: Scale‐value per radian for changes normal to the magnetic axis = (k + P), where k is ratio of torsion‐constant to magnetic moment and P is field parallel to axis. Some consequences are discussed, showing superiority over other scale‐value equations. This equation is adequate for the scale‐value of and H‐variometer unless the readings are to be combined accurately with those of another variometer.The subject is approached from a more general point of view. Horizontal intensity (H) is experimentally a function of ordinate (n), declination (D), and temperature (t). It is expressed by a Taylor's series in those variables. The resulting analysis shows: (a) This method avoids mistakes frequently made when second‐order effects are considered; (b) when properly defined in the most convenient way, the temperature‐coefficient is independent of ordinate and declination; (c) considerable error has resulted from the use of the wrong sign for the temperature‐coefficient of rigidity of quartz.Consideration of variations of scale‐value shows: (a) Turning the torsion‐head affects the base‐line scale‐value very little; (b) a simple formula for the effect of change of optical lever with ordinate results; (c) the principal part of the variation with ordinate is due to the fact that when the magnet turns, part of the Earth's field acts parallel to its axis; (d) for a simple H‐variometer the temperature‐coefficients of base‐line value and base‐line scale‐value are precisely the same; (e) a sensitivity‐control magnet may cause a large temperature‐effect on scale‐value; (f) optical compensation produces an effect opposite in sign to the normal one, sometimes smaller, sometimes much larger; (g) the correction necessary to observed scale‐values is deduced. The effects of change of D are considered. These may be considerable even with a properly‐adjusted variometer, especially if it be uncompensated or have optical compensation.A similar treatment for a D‐variometer shows: (a) The scale‐value may have considerable error unless corrected for the field of other magnets; (b) the effect of change of H is small and is wholly negligible if the variometer is properly adjusted—hence a D‐variometer is more accurate than any intensity‐variometer; (c) error in orientation may be detected and its magnitude may be estimated from the variometer's temperature‐coefficient.Similar methods applied to the component in a fixed direction show that the formulas are somewhat simpler than for an H‐variometer. Maladjustments are discussed and it is shown that the formulas used for computing diurnal variations of X and Y from those of H and D are frequently incorrect. Certain possible improvements in instrument‐design and operation are suggested.
The electricity of continuous rain
Authors: Chalmers J. Alan , Little E. W. R. 
Published: February 2008

The measurement of the electric charge on rain is of interest from two points of view; in the first place, the precipitation‐currents may be of importance in the discussion of what Wormell [see 23 of “References” at end of paper] has called “the electrical balance sheet of the Earth”; and further, the results for the charges on rain can give clues as to the mechanism involved in the acquisition of such charges and hence as to the processes at work in producing separation of charge in and below clouds.Measurements in various parts of the world have shown that there is a positive excess of charge brought down to the Earth, more especially in rain classified as “continuous,” “ordinary,” or “non‐stormy” (German “Landregen”). Apart from this, little has been achieved in the establishment of general results capable of providing a basis for theoretical discussion.
American URSI Broadcasts of Cosmic Data, Giving American Magnetic Character‐Figure, CA, Three‐Hour‐Range Indices, K, and Mean K‐Indices, KA, For July to September, 1941
Authors: Johnston H. F. 
Published: February 2008

Summaries of American URSI broadcasts have appeared regularly in this JOURNAL since the issue for December, 1930.As set forth in this JOURNAL for June, 1937, “The Department of Terrestrial Magnetism and the United States Coast and Geodetic Survey with the cooperation of the United States Army and the United States Navy communication‐services and several amateur radio stations have undertaken to supply the American character‐figure based upon the, reports of the seven American‐operated observatories—those of the Department of Terrestrial Magnetism at Huancayo in Peru and at Watheroo in Western Australia, and those of the United States Coast and Geodetic Survey at Cheltenham (Maryland), Honolulu (Hawaii), San Juan (Puerto Rico), Sitka (Alaska), and Tucson (Arizona).” This character‐figure is being designated CA, and its values for the first twelve, the second twelve, and all twenty‐four hours of each Greenwich day for July to September, 1941, are given in Table 1.
Soil Moisture Detection with Imaging Radars
Authors: Macdonald Harold C. , Waite William P. 
Published: February 2008

The high degree of correlation between the electrical properties of soil and soil moisture content are well known. Considerable experimental work has been conducted by using radar for the determination of soil moisture. However, in the transition from a controlled measurement device to an operational imaging radar, the effects of soil moisture have been extremely difficult to separate from other terrain parameters influencing the radar return signal.The data presented in this study suggest that presently available dual polarized, K‐band, side‐looking imaging radars provide a capability for revealing a qualitative estimate of soil moisture content. When used as a supplement to aerial photography in temperate climates, radar imagery analysis will decrease the ambiguity of soil type reconnaissance. In the Arctic, an imaging radar may provide data for mapping regions of permafrost, and this process could be accomplished in a sequential manner regardless of weather or time of day. The use of additional multifrequency multipolarization imaging radars and the relative foliage penetration of each should be investigated as a possible means of gathering quantitative soil moisture information.
Estimated Groundwater Yield following Strip Cutting in Pine Plantations
Authors: Urie Dean H. 
Published: February 2008

Groundwater recharge balances were determined under 40‐acre blocks of a jack pine (Pinus banksiana Lamb) plantation in northwestern lower Michigan during the 4 years following the removal of 50% of the trees in clear‐cut strips. Analyses were made by graphical interpretation of diurnal fluctuations and by use of finite difference equations. In the numerical method, weekly water table elevation measurements over each 40‐acre block were used to determine water table convexity, which was then linearly related to the groundwater inflow‐outflow balance.Results from both methods of analysis showed the effect of strip cutting as increased ground‐water yields. Estimates of water yield by the two methods differed primarily as a result of poor estimates of net evaporative loss from the saturated zone using the graphical method.Three other tests of cutting effects on groundwater recharge supported the budget estimates of treatment effect. Approximately 3 inches per year of additional water was produced as a result of the strip cut during the first 4 years after cutting. The numerical analysis showed that the amount of treatment effect decreased rapidly over this period.
Prediction of neuropeptide cleavage sites in insects
Authors: Southey Bruce R. , Sweedler Jonathan V. , Rodriguez-Zas Sandra L. 
Published: February 2008

Abstract
Motivation: The production of neuropeptides from their precursor proteins is the result of a complex series of enzymatic processing steps. Often, the annotation of new neuropeptide genes from sequence information outstrips biochemical assays and so bioinformatics tools can provide rapid information on the most likely peptides produced by a gene. Predicting the final bioactive neuropeptides from precursor proteins requires accurate algorithms to determine which locations in the protein are cleaved.
Results: Predictive models were trained on Apis mellifera and Drosophila melanogaster precursors using binary logistic regression, multi-layer perceptron and k-nearest neighbor models. The final predictive models included specific amino acids at locations relative to the cleavage sites. Correct classification rates ranged from 78 to 100% indicating that the models adequately predicted cleaved and non-cleaved positions across a wide range of neuropeptide families and insect species. The model trained on D.melanogaster data had better generalization properties than the model trained on A. mellifera for the data sets considered. The reliable and consistent performance of the models in the test data sets suggests that the bioinformatics strategies proposed here can accurately predict neuropeptides in insects with sequence information based on neuropeptides with biochemical and sequence information in well-studied species.
Contact: rodrgzzs@uiuc.edu
Supplementary information: Sequences and cleavage information are available at Bioinformatics online.
Decay of unused characters by selection and drift
Authors: HALL A. R. , COLEGRAVE N. 
Published: February 2008

AbstractThe reduction and loss of redundant phenotypic characters is a common feature of evolution. However, the mechanisms that drive deterioration of unused characters remain unclear. Here, we outline a simple framework where the relative importance of selective and neutral processes varies with environmental factors, because of variation in the fitness costs associated with unused traits. We tested our hypotheses using experimental evolution of the bacterium Pseudomonas fluorescens in spatially uniform environments. Results show that an unused character, swimming motility, decayed over evolutionary time and the rate of this decay varied among selection environments with different levels of resource availability. This is explained in the context of an environment‐specific genetic correlation between motility and fitness, which is negative when resources are limited but neutral at higher resource levels. Thus, selection against an unused character was most effective in environments where the fitness cost was the greatest. This suggests that the same character can decay by different mechanisms depending upon environmental factors and supports previous evidence to show that resource availability can critically affect the outcomes of evolution.
A hybrid zone dominated by fertile F1s of two alpine shrub species,Phyllodoce caeruleaandPhyllodoce aleutica, along a snowmelt gradient
Authors: KAMEYAMA Y. , KASAGI T. , KUDO G. 
Published: February 2008

AbstractIn alpine ecosystems, the steep environmental gradients produced by the difference in snowmelt timing create a dynamic selective regime for alpine plants. As these gradients directly alter flowering phenology, they can affect pollen‐mediated gene flow among populations of single and related species. In northern Japan, we found a hybrid zone dominated by fertile F1s of two alpine shrub species,Phyllodoce caeruleaandP. aleutica, along a snowmelt gradient. Seed germination confirmed the fertility of F1hybrid, making the rarity and absence of backcross and F2plants puzzling. The long‐term clonal perpetuation of F1hybrids (at least a few thousand years ago) contributes the maintenance of this unique hybrid zone. The distribution patterns of chloroplast DNA haplotypes suggest that F1formation might be caused by directional pollen flow between parental species along the snowmelt gradient. Based on these results, we discuss the ecological and evolutionary significance of this unique hybrid zone.
Apparent mutational hotspots and long distance linkage disequilibrium resulting from a bottleneck
Authors: TENAILLON M. I. , AUSTERLITZ F. , TENAILLON O. 
Published: February 2008

AbstractGenome wide patterns of nucleotide diversity and recombination reveal considerable variation including hotspots. Some studies suggest that these patterns are primarily dictated by individual locus history related at a broader scale to the population demographic history. Because bottlenecks have occurred in the history of numerous species, we undertook a simulation approach to investigate their impact on the patterns of aggregation of polymorphic sites and linkage disequilibrium (LD). We developed a new index (Polymorphism Aggregation Index) to characterize this aggregation and showed that variation in the density of polymorphic sites results from an interplay between the bottleneck scenario and the recombination rate. Under particular conditions, aggregation is maximized and apparent mutation hotspots resulting in a 50‐fold increase in polymorphic sites density can occur. In similar conditions, long distance LD can be detected.
m‐Learning: An experiment in using SMS to support learning new English language words
Authors: Cavus Nadire , Ibrahim Dogan 
Published: February 2008

AbstractThere is an increase use of wireless technologies in education all over the world. In fact, wireless technologies such as laptop computers, palmtop computers and mobile phones are revolutionising education and transforming the traditional classroom‐based learning and teaching into anytime and anywhere education. This paper investigates the use of wireless technologies in education with particular reference to the potential of learning new technical English language words using Short Message Service (SMS) text messaging. The system, developed by the authors, called mobile learning tool (MOLT), has been tested with 45 1st‐year undergraduate students. The knowledge of students before and after the experiment has been measured. Our results show that students enjoyed and learned new words with the help of their mobile phones. We believe that using the MOLT system as an educational tool will contribute to the success of students.
Plural Agents
Authors: Helm Bennett W. 
Published: February 2008

AbstractGenuine agents are able to engage in activity because they find it worth pursuing—because they care about it. In this respect, they differ from what might be called “mere intentional systems”: systems like chess‐playing computers that exhibit merely goal‐directed behavior mediated by instrumental rationality, without caring. A parallel distinction can be made in the domain of social activity: plural agents must be distinguished from plural intentional systems in that plural agents have cares and engage in activity because of those cares. In this paper, I sketch an account of what it is for an individual to care about things in terms of her exhibiting a certain pattern of emotions. After extending this account to make sense of an individual's caring about other agents, I then show how a certain sort of emotional connectedness among a group of people can make intelligible the group's having cares and thereby constitute that group as a plural agent. Alternative accounts of social action, by ignoring the difference between mere intentional systems and genuine agents, and so by leaving out these emotional entanglements from their accounts of social action, thereby fail to capture a whole range of social phenomena involving plural agents.
2. REASONS, GENERALIZATIONS, EMPATHY, AND NARRATIVES: THE EPISTEMIC STRUCTURE OF ACTION EXPLANATION
Authors: STUEBER KARSTEN R. 
Published: February 2008

ABSTRACTIt has become something of a consensus among philosophers of history that historians, in contrast to natural scientists, explain in a narrative fashion. Unfortunately, philosophers of history have not said much about how it is that narratives have explanatory power. They do, however, maintain that a narrative's explanatory power is sui generis and independent of our empathetic or reenactive capacities and of our knowledge of law‐like generalizations. In this article I will show that this consensus is mistaken at least in respect to explanatory strategies used to account for rational agency using the “folk‐psychological” framework of intentions, beliefs, desires, and the like. Philosophers distinguish insufficiently among different aspects and different types of information needed for a historian to persuasively account for an agent's behavior in particular circumstances. If one keeps these aspects apart it will become apparent exactly how one should understand the epistemic contribution of empathy, generalizations, and narrative for the explanation of action.
Lovastatin inhibits amyloid precursor protein (APP) β‐cleavage through reduction of APP distribution in Lubrol WX extractable low density lipid rafts
Authors: Won Je‐Seong , Im Yeong‐Bin , Khan Mushfiquddin , Contreras Miguel , Singh Avtar K. , Singh Inderjit 
Published: February 2008

AbstractPrevious studies have described that statins (inhibitors of cholesterol and isoprenoid biosynthesis) inhibit the output of amyloid‐β (Aβ) in the animal model and thus decrease risk of Alzheimer’s disease. However, their action mechanism(s) in Aβ precursor protein (APP) processing and Aβ generation is not fully understood. In this study, we report that lovastatin treatment reduced Aβ output in cultured hippocampal neurons as a result of reduced APP levels and β‐secretase activities in low density Lubrol WX (non‐ionic detergent) extractable lipid rafts (LDLR). Rather than altering cholesterol levels in lipid raft fractions and thus disrupting lipid raft structure, lovastatin decreased Aβ generation through down‐regulating geranylgeranyl‐pyrophosphate dependent endocytosis pathway. The inhibition of APP endocytosis by treatment with lovastatin and reduction of APP levels in LDLR fractions by treatment with phenylarsine oxide (a general endocytosis inhibitor) support the involvement of APP endocytosis in APP distribution in LDLR fractions and subsequent APP β‐cleavage. Moreover, lovastatin‐mediated down‐regulation of endocytosis regulators, such as early endosomal antigen 1, dynamin‐1, and phosphatidylinositol 3‐kinase activity, indicates that lovastatin modulates APP endocytosis possibly through its pleiotropic effects on endocytic regulators. Collectively, these data report that lovastatin mediates inhibition of LDLR distribution and β‐cleavage of APP in a geranylgeranyl‐pyrophosphate and endocytosis‐dependent manner.
IDENTIFICATION OF GENES PREFERENTIALLY EXPRESSED DURING ASEXUAL SPORULATION IN PORPHYRA YEZOENSIS GAMETOPHYTES (BANGIALES, RHODOPHYTA)1
Authors: Kitade Yukihiro , Asamizu Erika , Fukuda Satoru , Nakajima Maiko , Ootsuka Shuuji , Endo Hirotoshi , Tabata Satoshi , Saga Naotsune 
Published: February 2008

Asexual reproduction via archeospores in Porphyra yezoensis Ueda gametophytes is a very valuable character to nori farming; however, there is little information available on the molecular basis of the developmental process. To identify genes involved in the Porphyra asexual sporulation, we compared the gene expression profiles derived from four developmental stages of the life cycle (three from gametophytes; one from sporophytes) using cDNA macroarray, which includes 4,896 nonredundant expressed sequence tag (EST) groups. Candidate genes were screened by two different macroarray data analyses combined with reverse transcription‐PCR (RT‐PCR) analysis or Northern analysis. RT‐PCR analysis revealed that nine genes (one: similarity to 5′–3′ exoribonuclease; the other eight: no sequence similarity to known proteins) were expressed with a gametophyte (G)–specific manner, and two genes (named ASPO2608, ASPO1527) were expressed only in gametophytes that formed archeospores. The deduced amino acid sequences for the latter two genes are predicted to contain signal peptides for secretion at their N‐termini. Northern analysis revealed that expression levels of Calvin cycle genes in the gametophytic stage that formed archeospores (G‐A stage) were higher than those of the gametophyte blade with no archeospores (G‐NA stage). In the macroarray analysis based on the rank data of G‐preferentially expressed genes, which were detected in the previous P. yezoensis EST analysis, one gene encoding the cyclase associated protein (CAP) exhibited a change upwardly in the G‐A stage >1,000 ranks to the G‐NA stage. We propose that ASPO2608 and CAP may function in a signaling pathway of asexual sporulation.
PRIMARY STEPS OF PHOTOCHEMICAL REACTIONS IN PROTEINS AND AROMATIC AMINO‐ACIDS: A REVIEW*
Authors: Vladimirov Yu. A. 
Published: February 2008

Abstract— Studies of the luminescence and excitation spectra of proteins showed that in proteins, in contrast with mixed crystals of the amino acids, the migration of energy from tyrosine to tryptophan takes place in low yield. The migration of energy between nucleotides and from nucleotides to acridine orange in DNA proceeded with an average yield of 66%.The luminescence of more than ten proteins studied, at pH 1.0–13.0, temperatures from — 196 to + 100°C and monochromatic excitation from 240 to 303 mp was established as due to the luminescence of tyrosine and tryptophan. The amounts of energy stored by the molecules of these compounds in singlet and triplet excited states were 80 and 60 Kcal./ mole respectively. A sudden difference in the structure of the phosphorescence and fluorescence spectra suggests that the transition to the triplet state is connected with changes in the vibrational configurations of the molecules, which prepare conditions for a photochemical event. The enhanced probability of an S →T transition during a change in pH or the addition of KI always led to an increase in the rate of ‘fading’ of luminescence under irradiation by the exciting light.A comparison of the kinetics of bleaching of the luminescence of samples with low‐temperature thermoluminescence showed that two photo‐products had been formed under U.V. irradiation at 77°K. Product Rt, responsible for the thermoluminescence, recombined through the triplet state with the emission of a quantum on warming to 80–100°K or on supplementary irradiation by visible light. Product Rb, accumulating on fading of the original, was stable to light and was transformed to the original amino acid without emitting a quantum at a temperature of 150–200° K. At room temperature aromatic amino acid groups entered into two photo‐chemical reactions: (1) photo‐oxidation by atmospheric oxygen and (2) reaction with adjoining groups of the protein, not requiring the presence of oxygen. Reaction (2), probably the main one for peptides and proteins, may lead to the formation of cross links between peptide chains, and to photoinactivation.
Linear series and the existence of branched covers
Authors: Osserman Brian 
Published: January 2008

AbstractIn this paper, we use the perspective of linear series, and in particular results following from the degeneration tools of limit linear series, to give a number of new results on the existence and non-existence of tamely branched covers of the projective line in positive characteristic. Our results are both in terms of ramification indices and the sharper invariant of monodromy cycles, and the first class of results are obtained by intrinsically algebraic and positive-characteristic arguments.