scholarly journals Spatial Patterns of Mass-balance Fluctuations of North American Glaciers

1989 ◽  
Vol 35 (120) ◽  
pp. 163-168 ◽  
Author(s):  
Anne Letrèguilly ◽  
Louis Reynaud

Abstract Long-term records (10–30 years of measurements) of North American glaciers are compared using Lliboutry’s simplified linear model. This model separates the mass balance into two additive terms, one dependent on the location of the glacier and the other on time. The time-dependent term provides a common signal for the variations of different glaciers. Principal-component analysis indicates that these similarities amount to between 65 and 70% of the total variance for glaciers up to about 500 km apart. Within this distance, similar variations of mass balance and, therefore the same yearly climatic variations, can be observed.

HortScience ◽  
2010 ◽  
Vol 45 (8) ◽  
pp. 1205-1210 ◽  
Author(s):  
Mark K. Ehlenfeldt ◽  
James J. Polashock ◽  
Allan W. Stretch ◽  
Matthew Kramer

Mummy berry disease of blueberry has two distinct phases: a blighting phase that infects emerging shoots and leaves early in the spring and a flower infection phase that ultimately leads to infected (mummified) fruit. Cultivated blueberry (Vaccinium spp.) genotypes that are resistant to one phase are not necessarily resistant to the other phase. The resistance of cultivated blueberry (Vaccinium spp.) genotypes to each phase of the disease is different. A large number of cultivars were screened for resistance to each phase. Cultivar standards (cultivars with well-documented responses to the disease) were used in the screening to evaluate long-term variation and aid comparisons across years. Using nine standards for the blight phase, 125 cultivars were tested and ranked for relative resistance using a ranking system based on resampling and principal component analysis. Similarly, using six standards for the flower/fruit infection stage, 110 blueberry cultivars were tested and ranked for relative resistance. Cultivar rankings show that lowbush cultivars and other types possessing high percentages of lowbush germplasm are generally more resistant to both phases of the disease. Among highbush cultivars, Bluejay is reliably resistant to both phases. Documentation of resistance to each phase will allow selection of cultivars for planting in affected areas and will facilitate the development of breeding strategies to produce cultivars with superior resistance.


2013 ◽  
Vol 291-294 ◽  
pp. 2381-2386 ◽  
Author(s):  
Wen Xia Liu ◽  
Ji Kai Xu ◽  
Hong Yuan Jiang ◽  
Yong Tao Shen

It is the foundation for evaluating the reliability of transmission lines to obtain and analyze the original reliability parameters. However, these parameters depend on long- term statistic and calculation. In the case of lacking such parameters in a new project , this paper proposes a method of Principal Component Analysis to obtain the principal component of the impacting factors ,in which various factors affecting reliability parameters are taken into account. Through this method, we can use PCR to obtain the failure rate of the unknown transmission lines on the base of the known credible lines’ rates. The simulation results show that the proposed approach possesses higher forecasting accuracy and provides references for the power system dispatching departments and transmission lines maintenance departments.


2011 ◽  
Vol 35 (6) ◽  
pp. 1172-1176 ◽  
Author(s):  
Alberto Miele ◽  
Luiz Antenor Rizzon

The purpose of this paper was to establish the sensory characteristics of wines made from old and newly introduced red grape varieties. To attain this objective, 16 Brazilian red varietal wines were evaluated by a sensory panel of enologists who assessed wines according to their aroma and flavor descriptors. A 90 mm unstructured scale was used to quantify the intensity of 26 descriptors, which were analyzed by means of the Principal Component Analysis (PCA). The PCA showed that three important components represented 74.11% of the total variation. PC 1 discriminated Tempranillo, Marselan and Ruby Cabernet wines, with Tempranillo being characterized by its equilibrium, quality, harmony, persistence and body, as well as by, fruity, spicy and oaky characters. The other two varietals were defined by vegetal, oaky and salty characteristics; PC 2 discriminated Pinot Noir, Sangiovese, Cabernet Sauvignon and Arinarnoa, where Pinot Noir was characterized by its floral flavor; PC 3 discriminated only Malbec, which had weak, floral and fruity characteristics. The other varietal wines did not show important discriminating effects.


2010 ◽  
Vol 62 (4) ◽  
pp. 1151-1162 ◽  
Author(s):  
Marina Juskovic ◽  
P. Vasiljevic ◽  
V. Randjelovic ◽  
V. Stevanovic ◽  
Branka Stevanovic

Daphne malyana Blecic (Thymeleaceae) is an endemic species of the western part of the Balkan Peninsula, distributed in the mountains, canyons and gorges of N. Montenegro, E. Bosnia and W. Serbia. The comparative morphoanatomic investigations have included four distantly separated populations of the species D. malyana, i.e. two from Serbia, from the ravines of Sokoline and Vranjak on Mt. Tara, and two from Montenegro, in the canyons of the Tara and Piva rivers. Comparative morphoanatomical studies have shown the presence of general adaptive characteristics of a specific, conservative xeromorphic type, slightly differing in each population. Principal component analysis (PCA) and canonical discriminant analysis (CDA) of 20 morphoanatomical characteristics of the leaves and stems have shown a clear distinction between the populations from the river Piva canyon (Montenegro) and those from the Sokoline ravine (Serbia), on one side, and those of Vranjak gorge (Serbia) and of the river Tara canyon (Montenegro) on the other side. It may be assumed that the mild morphological variability of the isolated populations of the Balkan endemic species D. malyana in the canyons and gorges seem to have been affected by the microclimate conditions in their habitats.


Atmosphere ◽  
2016 ◽  
Vol 7 (12) ◽  
pp. 155 ◽  
Author(s):  
Barbara Giussani ◽  
Simone Roncoroni ◽  
Sandro Recchia ◽  
Andrea Pozzi

Zootaxa ◽  
2020 ◽  
Vol 4861 (3) ◽  
pp. 429-443
Author(s):  
CAROLINA PIRES ◽  
MARCELO WEKSLER ◽  
CIBELE R. BONVICINO

The region of Lagoa Santa, Minas Gerais, Brazil, is one of the most important karstic areas of the Brazilian Quaternary due to the faunistic diversity of living and extinct forms. Among them, some taxa remain poorly studied, as is the case of Calomys anoblepas Winge 1887. Despite the recent allocation of the taxon within Juliomys, its description and morphological analysis are condensed, based on comparative few specimens and on few informative characters. In this study, we investigate characters proposed to distinguish species of Juliomys, and reevaluate the taxonomic status of the fossil Juliomys anoblepas. We analyzed 80 cranio-dental morphological characters in 233 specimens represented by the four species currently recognized: J. pictipes (Osgood 1933), J. rimofrons Oliveira & Bonvicino 2002, J. ossitenuis Costa, Pavan, Leite & Fagundes 2007, and J. ximenezi Christoff, Vieira, Oliveira, Gonçalves, Valiati & Tomasi 2016. We also performed principal component analysis on eight craniodental measurements available for the J. anoblepas hypodigm. The review of morphological systems and the evaluation of the characters used in the literature revealed that there are no diagnostic characters in the anterior portion of the skull and in the molar series of Juliomys, being difficult to differentiate the fossil from the other living species. Only six qualitative characters were variable and applicable to the hypodigm of J. anoblepas. Characters are polymorphic, invariable, or the fossil is not sufficiently complete to determinate its states. The taxon could not be morphometrically differentiated from J. pictipes and J. ossitenuis. Based on the results presented herein, we consider J. anoblepas as a nomen dubium and restrict its name to the taxon’s hypodigm. 


2020 ◽  
Vol 3 ◽  
pp. 205920432091684
Author(s):  
Ivan Jimenez ◽  
Tuire Kuusi ◽  
Christopher Doll

Although Western tonal syntax can generate a very large number of chord successions of various lengths and degrees of complexity, some types of music, from Renaissance dances to recent pop, tend to rely more heavily on the repetition of relatively simple, short harmonic patterns. Doll recently identified short chord progressions commonly found in North American and British popular music and proposed that these chord progressions can be stored in long-term memory in the form of harmonic schemata that allow listeners to hear them as stereotypical chord progressions. However, considering the challenges that many listeners face when trying to consciously grasp harmony, it seems likely that the feelings of remembering chord progressions varies from listener to listener. To investigate these potential differences, we asked 231 listeners with various levels of musical training to rate their confidence on whether or not they had previously heard six diatonic four-chord progressions. To control for the effect of extra-harmonic features, we instantiated the chord progressions in a way that resembled the piano of a famous song and controlled for participants’ familiarity with that song and whether they had played its chords. We found that ratings correlated with typicality for the two groups of participants who had played an instrument for at least one year and to a lesser extent for the other participants. Additionally, all our players thought of specific songs more often and mentioned songs that better matched the stimuli in harmonic terms. What we did not find, however, was any effect associated to how long participants had played an instrument or the type of the instrument they had played. Our research supports the notion that both musical training and extra-harmonic features affect listeners’ feelings of remembering chord progressions.


1976 ◽  
Vol 129 (6) ◽  
pp. 598-603 ◽  
Author(s):  
C. J. Lucas ◽  
Sidney Grown ◽  
Peter Stringer ◽  
Saradha Supramaniam

SummaryThe UCLS questionnaire, in a form modified to include a measure of syllabus-boundness, and a questionnaire to measure psychiatric symptomatology (the MHQ) were administered to two groups of students, one seeking help for emotional problems, the other a control group. Groups were compared on tests, test findings were inter-correlated, and scores were related to academic success. The UCLSQ is confirmed as a reliable research instrument. Principal component analysis again indicates a separation of psychoneurotic and motivational components of study difficulty. Syllabus-boundness (‘Sylbism’) emerges as a relatively independent trait, with a significant negative relationship to work satisfaction in both groups. MHQ, scores again show a positive correlation between phobic anxiety and academic attainment for patients.


Sign in / Sign up

Export Citation Format

Share Document